Reviews of European Patents on Nickel/Metal Hydride Batteries

batteries

Review Reviews of European Patents on Nickel/Metal Hydride Batteries

Shiuan Chang 1,2, Kwo-Hsiung Young 2,3,* ID and Yu-Ling Lien 4 1 Department of Mechanical Engineering, Wayne State University, Detroit, MI 48202, USA; [email protected] 2 BASF/Battery Materials—Ovonic, 2983 Waterview Drive, Rochester Hills, MI 48309, USA 3 Department of Chemical Engineering and Materials Science, Wayne State University, Detroit, MI 48202, USA 4 Department of Chemistry, Michigan State University, East Lansing, MI 48824, USA; [email protected] * Correspondence: [email protected]; Tel.: +1-248-293-7000

Academic Editor: Andreas Jossen Received: 22 June 2017; Accepted: 27 July 2017; Published: 26 August 2017

Abstract: Patent applications in the field of nickel/metal hydride (Ni/MH) batteries are reviewed to provide a solid technology background and directions for future developments. As the fourth review article in the series of investigations into intellectual properties in this area, this article focuses on 126 patent applications filed by European companies at the European Patent Office, while the earlier articles dealt with those from USA, Japan, and China. The history and current status of the key companies in the Ni/MH battery business are briefly discussed. These companies are categorized by their main roles in the industry, i.e., battery manufacturer, metal hydride alloy supplier, separator supplier, and others. While some European companies are pioneers in bringing the Ni/MH product to customers, others have made significant contributions to the development of the technology, especially in the button cell, bipolar cell, and separator areas.

Keywords: nickel metal hydride battery; European patent; metal hydride alloy; nickel hydroxide; European battery manufacturer

1. Introduction Nickel/metal hydride (Ni/MH) batteries are widely used in consumer electronics, stationary energy storage, and hybrid electric vehicles (HEV). Their advantages are in energy density (compared to the replaced NiCd), cycle stability at deep discharge (>3000), robust construction, ability to be quickly charged, environmental friendliness, and higher abuse tolerance (compared to the Li product) [1]. Two types of Ni/MH batteries are available: the small consumer type (usually cylindrical with a capacity <4 Ah) and the larger transportation type (usually prismatic with a capacity >6 Ah). Nowadays, most consumer type and HEV Ni/MH batteries are produced in China and Japan. Nevertheless, European companies still have a small portion of the market share (for example, about 10% in 2013 [2]) (Figure1a). On the other hand, European countries are a large market for consumer type Ni/MH batteries. For instance, in 2013, Germany, the Netherlands, Belgium, and the UK accounted for a combined 8.3% of the Ni/MH batteries exported from China [2] (Figure1b), and in February 2014 Europe received 32.7% of the Ni/MH batteries from Japanese manufacturers (mainly FDK, Tokyo, Japan) [2] (Figure1c). European companies made great contributions to the debut of Ni/MH batteries in their early days. For example, Klaus-Dieter Beccu from Battelle Memorial Institute (Geneva, Switzerland) contributed to the earliest patent using MH alloy as the active material in the negative electrode to construct a Ni/MH battery in 1970 [3]; Annick Percheron-Guégen and her coworkers from the Agence Nationale de Valorisation de la Recherche (Neuilly sur Seine, France) filed the first patent of using LaNi5 modified with Ti, Ca, Ba, Cr, and/or Cu with improved capacity as

Batteries 2017, 3, 25; doi:10.3390/batteries3030025 www.mdpi.com/journal/batteries Batteries 2017, 3, 25 2 of 16

Batteriesfiled the 2017 first, 3, 25 patent of using LaNi5 modified with Ti, Ca, Ba, Cr, and/or Cu with improved capacity2 of 16 as negative electrode material in 1978 [4]; and Johannes Willems, Johann van Beek, and Buschow Kurt filedfrom the Philips first patent(Eindhoven, of using Netherlands) LaNi5 modified filed witha USA Ti, patent Ca, Ba, adding Cr, an Cod/or and/or Cu with Cu improved in LaNi5 to capacity reduce asthe negative lattice expansion electrode materialduring hydride in 1978 process[4]; and andJohannes consequently Willems, extend Johann the van cycle Beek, life and in Buschow1984 [5]. In Kurt the frompast, Philipswe have (Eindhoven, reviewed theNetherlands) Ni/MH-related filed apatents USA patent (or patents adding applications) Co and/or Cu filed in LaNiin the5 to USA reduce [6], theJapan lattice [7], expansionand China during[8]. In this hydride review, process we focus and on cons patentequently applications extend the to thecycle European life in 1984 Patent [5]. InOffice the past,submitted we have by Europeanreviewed companies;the Ni/MH-related these applicants patents (or are patents grouped applications) as battery manufacturers,filed in the USA metal [6], Japanhydride [7], (MH) and China alloy suppliers,[8]. In this separatorreview, we suppliers, focus on patentand others. applications The patent to the applications European Patentcan be Officefound submittedonline through by European the website companies; of World these Intellectual applicants Proper arety grouped Organization as battery (WIPO) manufacturers, [9]. In the case metal of a hydridenon-English (MH) description, alloy suppliers, a machine separator translation suppliers, option and suppliedothers. The by patentWIPO applicationsis available free can ofbe charge. found onlineA brief through introduction the website of European of World companies Intellectual contri Properbutingty toOrganization the European (WIPO) Patent [9]. Application In the case (EPA) of a non-Englishis included in description, Table 1. a machine translation option supplied by WIPO is available free of charge. A brief introduction of European companies contributing to the European Patent Application (EPA) is included in Table 1.

Batteries 2017, 3, 25 (a) (b) 2 of 16

(a) (b) negative electrode material in 1978 [4]; and Johannes Willems, Johann van Beek, and Buschow Kurt from Philips (Eindhoven, Netherlands) filed a USA patent adding Co and/or Cu in LaNi5 to reduce the lattice expansion during hydride process and consequently extend the cycle life in 1984 [5]. In the past, we have reviewed the Ni/MH-related patents (or patents applications) filed in the USA [6], Japan [7], and China [8]. In this review, we focus on patent applications to the European Patent Office submitted by European companies; these applicants are grouped as battery manufacturers, metal hydride (MH) alloy suppliers, separator suppliers,(c) and others. The patent applications can be found online through the website of World Intellectual Property Organization (WIPO) [9]. In the case of a Figure 1. Consumer Ni/MH battery market shares for (a) Sources in 2013, (b) Exports from China in (c) non-English2013, and description, (c) Exports from a machine Japan in February translation 2014. Data option originate supplied from [2]. by WIPO is available free of charge. A briefFigure introduction 1. Consumer of EuropeanNi/MH battery companies market shares contributing for (a) Sources to in the 2013, European (b) Exports Patent from China Application in (EPA) is included2013,Table in and Table1. European(c) 1Exports. companies from Japan related in February to Ni/MH 2014. battery Data originate manufacturing from [2]. included in this review, in order of their presence. Batteries 2017, 3, 25 3 of 16 TableTable 1. 1.European European companies related related to toNi/MH Ni/MH battery battery manufacturing manufacturing included included in this review, in this in review, in Company Products Related Batteriesorderorder 2017 of of, their3 ,their 25 presence. presence.Headquarter Trademark Website 3 of 16 Name to Ni/MH BatteriesCompany 2017, 3, 25 Products Related 3 of 16 Headquarter Trademark Website Company Ellwangen, ProductsAAA Relatedto FA, http://www.varta- NameVarta Headquarter to Ni/MH Trademark Website Name to Ni/MH Germany button cell microbattery.be/ Ellwangen,Bagnolet, AAA to FA, http://www.varta- Batteries 2017VartaSaft, 3 , 25 C, D, F-size cells http://saftbatteries.com/3 of 16 GermanyFrance button cell microbattery.be/ Batteries 2017, 3, 25 Ellwangen, AAA to FA, http://www.varta- 3 of 16 Varta Bagnolet, SaftSaft Bagnolet,Germany France C,C, D,D,button F-sizeF-size cell cellscells http://saftbatteries.com/microbattery.be/http://saftbatteries.com/ Batteries 2017, 3, 25 France 3 of 16

Prismatic, bipolar Nilar Täby,Ellwangen, Sweden AAA to FA, http://www.nilar.com/http://www.varta- Batteries 2017Varta, 3 , 25 cell 3 of 16 Ellwangen,Germany Prismatic,AAAbutton to bipolarcell FA, http://www.varta-microbattery.be/ VartaNilar Täby,Nersac, Sweden http://www.nilar.com/http://www.arts- Germany button cell microbattery.be/ Arts EnergyArts Energy Nersac, France C,C, D, D, F-size F-sizecell cells cells http://www.arts-energy.com Ellwangen,France Prismatic,AAA to bipolarFA, http://www.varta-energy.com VartaNilar Täby, Sweden http://www.nilar.com/ Germany buttoncell cell microbattery.be/ Nersac, http://www.arts- Arts Energy Ellwangen, C, AAAD,Cell F-size phoneto FA, cells http://www5.alcatel-http://www.varta- Alcatel Paris,France France energy.com Varta Ellwangen, AAA to FA, Varta Germany Prismatic,buttonbattery bipolarcell http://www.varta-microbattery.be/microbattery.be/lucent.com Nilar GermanyTäby, Sweden Prismatic,buttonCell phone cellbipolar http://www.nilar.com/http://www5.alcatel- AlcatelNilar Täby,Paris, Sweden France cell http://www.nilar.com/ batterycell lucent.com Cell phone http://www5.alcatel- Alcatel Paris,Brilon- France Prismatic,Prismatic, bipolarbipolar NilarNilar Täby,Täby, Sweden Sweden battery https://www.hoppecke.cohttp://www.nilar.com/lucent.comhttp://www.nilar.com/ Hoppecke Hoppecke, Prismaticcellcell cell Batteries 2017, 3, 25 m/ 3 of 15 GermanyBrilon- Prismatic, bipolar Nilar Täby, Sweden Cell phone https://www.hoppecke.cohttp://www.nilar.com/http://www5.alcatel- HoppeckeAlcatel Paris,Hoppecke, France Prismaticcell cell Brilon- CellCellbattery phone phone http://www5.alcatel-lucent.comm/ AlcatelAlcatel Paris,Paris,Germany France France Cell phone https://www.hoppecke.cohttp://www5.alcatelhttp://www5.alcatel-lucent.com- HoppeckeAlcatel Paris,Hoppecke, France Prismaticbatterybattery cell lucent.com Nuremberg, Cellbattery phone http://www5.alcatel-lucent.comm/ AlcatelGfE Paris,Germany France MH alloy powder http://www.gfe.com Germany battery lucent.com Brilon-Brilon- Brilon-Hoppecke,Nuremberg,Brilon- Cell phone https://www.hoppecke.cohttp://www5.alcatel- HoppeckeHoppeckeAlcatelGfE Paris,Hoppecke, France MHPrismaticPrismatic alloy powder cell cell https://www.hoppecke.cohttp://www.gfe.comhttps://www.hoppecke.com/ Hoppecke GermanyHoppecke,Germany Prismaticbattery cell lucent.comm/ Nuremberg,Germany m/ GfE GermanyBrilon- MH alloy powder http://www.gfe.com Germany https://www.hoppecke.co Hoppecke Hoppecke, Prismatic cell Nuremberg,Nuremberg, MH alloy m/ GfE GfE GermanyAlthofen,Brilon- MH alloy powder https://www.treibacher.chttp://www.gfe.comhttp://www.gfe.com Treibacher GermanyNuremberg,Germany MHpowder alloy powder https://www.hoppecke.co HoppeckeGfE Hoppecke,Austria MHPrismatic alloy powder cell http://www.gfe.comom Nuremberg,GermanyAlthofen, https://www.treibacher.cm/ TreibacherGfE Germany MH alloy powder http://www.gfe.com Althofen,Germany https://www.treibacher.c Austria om Treibacher Nuremberg,Althofen, MHMH alloy alloy powder https://www.treibacher.c TreibacherTreibacherGfE Althofen, Austria Austria MH alloy powder http://www.gfe.comhttps://www.treibacher.comom GermanyAustria powder om

SciMat Swindon,Nuremberg, UK Separator Not available now GfE MH alloy powder http://www.gfe.com Althofen,Germany https://www.treibacher.c SciMatTreibacherSciMat Swindon,Swindon,Weinheim,Althofen, UK UK MH Separator Separatoralloy powder http://www.freudenberg.https://www.treibacher.cNot availableNot available now now FreudenbergTreibacher Austria MH Separatoralloy powder om GermanyAustria comom SciMat Swindon, UK Separator Not available now Althofen, https://www.treibacher.c Treibacher Weinheim,Weinheim, MH alloy powder http://www.freudenberg. FreudenbergFreudenberg Austria SeparatorSeparator http://www.freudenberg.comom 2. Ni/MH BatteryGermany ManufacturerGermany com Althofen, https://www.treibacher.c Treibacher Weinheim, MH alloy powder http://www.freudenberg. FreudenbergPatentSciMat applications Swindon,Austria from UK five European Separator battery/chemical companies relatedNot available to omthe fabrication now of SciMat Swindon,Germany UK Separator Not availablecom now Weinheim, http://www.freudenberg. Ni/MHFreudenberg batteries are reviewed in thisSeparator section. There are two large European companies, Varta 2. Ni/MH Battery ManufacturerGermany com (Ellwangen,SciMat Germany)Swindon, and UK SAFT (Bagnolet, Separator France), that manufactured Not consumer-type available now Ni/MH

batteries2. Ni/MHPatent and Battery applications submitted ManufacturerWeinheim, patent from five applications European in battery/chemical related fields over companies the past http://www.freudenberg.tworelated decades. to the Infabrication 2002, Varta of FreudenbergSciMat Swindon, UK Separator Not available now microbatteryNi/MH batteries spun are offWeinheim,Germany fromreviewed Varta in and this focused section. on theThere button are celltwo business. large European Inhttp://www.freudenberg. 2013, SAFT companies,com sold its SmallVarta 2. Ni/MHFreudenbergPatent Battery applications Manufacturer from five EuropeanSeparator battery/chemical companies related to the fabrication of Nickel(Ellwangen, Battery Germany) divisionGermany and to SAFT Arts Energy(Bagnolet, (Nersac, Franc e France).), that manufactured Alcatel (later consumer-type mergedcom into Ni/MH Lucent Ni/MH batteries areWeinheim, reviewed in this section. There are two large Europeanhttp://www.freudenberg. companies, Varta Technology,batteriesFreudenbergPatent and applications Paris,submitted France) patentfrom made five applications European Ni/MHSeparator batteries in battery/chemical relate d for fields cell over phones companies the andpast wasrelatedtwo decades. active to the in In fabrication filing 2002, patent Varta of (Ellwangen, Germany)Germany and SAFT (Bagnolet, France), that manufactured consumer-typecom Ni/MH 2.applications.Ni/MHmicrobattery Ni/MH batteries Battery spunRecently, areManufacturer offWeinheim, fromreviewed Nilar Varta (Täby, in and this Sweden) focused section. onbegan thTheree buttonto offerare celltwo bi-polar business. large prismatic European http://www.freudenberg.In 2013, Ni/MH SAFTcompanies, sold batteries its VartaSmall for 2.batteries Ni/MHFreudenberg and Battery submitted Manufacturer patent applications Separator in related fields over the past two decades. In 2002, Varta transportation(Ellwangen,Nickel Battery Germany) applications.divisionGermany and to HoppeckeSAFTArts Energy(Bagnolet, (Brilon-Hoppecke, (Nersac, Franc e),France). that Germany) manufactured Alcatel made (later consumer-type prismatic mergedcom flooded-typeinto Ni/MHLucent microbatteryPatent applications spun off from from Varta five and European focused battery/chemical on the button cell companies business. Inrelated 2013, to SAFT the fabricationsold its Small of Ni/MHbatteriesTechnology,Patent batteries and applications Paris,submitted for France) transportation patentfrom made five applications EuropeanNi/MH applications. batteries in battery/chemical relate dfor fields cell overphones companies the pastand tworelatedwas decades.active to the in In fabricationfiling 2002, patent Varta of 2.Ni/MHNickel Ni/MH Batterybatteries Battery division areManufacturer reviewed to Arts in Energythis section. (Nersac, There France). are two Alcatel large European(later merged companies, into Lucent Varta microbatteryNi/MHapplications. batteries spunRecently, are off fromreviewed Nilar Varta (Täby, in and this Sweden) focused section. onbegan thTheree buttonto offerare celltwo bi-polar business. large prismatic European In 2013, Ni/MH SAFT companies, sold batteries its SmallVarta for (Ellwangen,Technology,Patent applications Germany)Paris, France) fromand made SAFTfive EuropeanNi/MH (Bagnolet, batteries battery/chemical Franc fore), cellthat phones manufacturedcompanies and relatedwas consumer-type active to the in fabrication filing Ni/MH patent of 2.2.1.Nickel(Ellwangen,transportation Ni/MH SAFT Battery andBattery Germany) Arts applications.division ManufacturerEnergy and to HoppeckeSAFTArts Energy(Bagnolet, (Brilon-Ho (Nersac, Francppecke, e),France). that Germany) manufactured Alcatel made(later consumer-typeprismatic merged flooded-typeinto Ni/MHLucent batteriesapplications. and submittedRecently, Nilarpatent (Täby, applications Sweden) in relatebegand to fields offer over bi-polar the past prismatic two decades. Ni/MH In batteries 2002, Varta for Ni/MHTechnology,Ni/MH batteries Paris, forare France) transportation reviewed made in Ni/MH applications.this section. batteries There for arecell twophones large and European was active companies, in filing patentVarta batteriesPatentThe andSociété applications submitted des Accumulateurs patentfrom five applications EuropeanFixes et al in Tractionbattery/chemical related (SAFT) fields overwas companies thefounded past relatedtwo in 1918 decades. to and the manufacturedInfabrication 2002, Varta of (Ellwangen,microbatteryapplications.transportation Germany)spunRecently, applications. off from Nilarand Varta HoppeckeSAFT(Täby, and (Bagnolet,Sweden) focused (Brilon-Ho on beganFranc theppecke, buttoneto), offerthat cellGermany) bi-polarmanufactured business. prismaticmade In 2013, consumer-typeprismatic Ni/MH SAFT sold flooded-typebatteries itsNi/MH Small for Ni/MHbatteriesmicrobattery batteries for spun the luggageare off fromreviewed cartsVarta in and and this lightingfocused section. on in thThere locomotives.e button are celltwo Inbusiness. large 2006, European SaftIn 2013, and SAFTcompanies, Johnson sold Controlsits VartaSmall batteriesNickeltransportationNi/MH2.1. SAFT Batterybatteries and and submitted Arts applications. divisionfor Energy transportation patent to HoppeckeArts applications applications.Energy (Brilon-Ho in(Nersac, relate ppecke,d fieldsFrance). Germany)over Alcatel the past made(later two prismaticdecades. merged In flooded-typeinto 2002, Lucent Varta (Ellwangen,(Milwaukee,Nickel Battery Germany)WI, division USA) formedand to SAFTArts a joint-venture Energy(Bagnolet, (Nersac, pursuingFranc e),France). thatbatteries manufactured Alcatel for electric (later vehiclesconsumer-type merged (EV) into and Ni/MHLucent HEV. microbatteryTechnology,Ni/MH batteries spunParis, for off France) transportation from Vartamade and Ni/MH applications. focused batteries on the forbutton cell cellphones business. and Inwas 2013, active SAFT in soldfiling its patent Small ItTechnology, wasThe acquired Société Paris, by des TotalFrance) Accumulateurs (Courbevoie, made Ni/MH France)Fixes batteries et and al delistedforTraction cell phonesfrom (SAFT) the and stock was was exchange foundedactive in in infiling 2016. 1918 patent SAFT and Nickelbatteriesapplications.2.1. SAFT Battery and and submittedRecently, Arts division Energy Nilar patent to (Täby,Arts applications Energy Sweden) in(Nersac, beganrelated to fieldsFrance). offer over bi-polar Alcatel the past prismatic (later two decades.merged Ni/MH In intobatteries 2002, Lucent Varta for microbatteryfiledapplications.manufactured 24 and 19 spunRecently, Europeanbatteries off from Nilarfor patent Vartathe (Täby, luggage applications and Sweden) focused carts (EPAs) andonbegan th lightinge frombuttonto offer 1990 in cell bi-polarlocomotives. to business. 2013 prismaticin theIn In 2013, name 2006, Ni/MH SAFT of Saft Accumulateurs sold andbatteries itsJohnson Small for Technology,transportation2.1. SAFTThe andSociété Paris, Artsapplications. desEnergyFrance) Accumulateurs made Hoppecke Ni/MH Fixes(Brilon-Ho batteries et alppecke, forTraction cell Germany)phones (SAFT) and madewas was prismaticfoundedactive in inflooded-typefiling 1918 patent and NickelFixestransportationControls and Battery (Milwaukee, SAFT applications. divisionSA, respectively. WI, to USA) HoppeckeArts formed InEnergy the (Brilon-Ho apositive joint-ventur(Nersac, electrodeppecke, France).e pursuing Germany)area, Alcatel SAFT batteries made filed(later for prismaticEPAs mergedelectric on thevehiclesflooded-typeinto following Lucent (EV) applications.Ni/MHmanufactured batteries Recently, batteries for transportation Nilar for the (Täby, luggage applications. Sweden) carts andbegan lighting to offer in bi-polarlocomotives. prismatic In 2006, Ni/MH Saft andbatteries Johnson for Technology,subjects:Ni/MHThe batteries aSociété fabrication Paris, for des France) transportation methodAccumulateurs made of co- Ni/MH applications.precipitated Fixes batteries et metalal forTraction hydroxide cell phones (SAFT) [10], and awas descriptionwas foundedactive ofin characteristicinfiling 1918 patent and transportationControls (Milwaukee, applications. WI, USA) Hoppecke formed (Brilon-Ho a joint-venturppecke,e pursuing Germany) batteries made for prismatic electric vehiclesflooded-type (EV) applications.2.1.ofmanufactured β SAFT-Ni(OH) and2 Recently, [11],Artsbatteries Energya fabrication Nilarfor the (Täby, luggage method Sweden) carts of pasted andbegan lighting electrode to offer in bi-polarlocomotives. [12,13], prismaticand Inuses 2006, Ni/MHof severalSaft andbatteries additives Johnson for Ni/MH2.1. SAFT batteries and Arts for Energy transportation applications. transportationincludingControls (Milwaukee, Celestine applications. [14], WI, CoO USA) Hoppecke with formed a spinal (Brilon-Ho a joint-ventur structureppecke, [15],e pursuing activeGermany) carbon batteries made [16], for prismatic Li(OH) electric2 [17],vehiclesflooded-type Ba(OH) (EV)2 The Société des Accumulateurs Fixes et al Traction (SAFT) was founded in 1918 and Ni/MHand Sr(OH)The batteries Société2 [18], for desNb transportation2 OAccumulateurs5 [19], non-conductive applications. Fixes et fiber al [20],Traction and plastic(SAFT) binderswas founded [21–23]. in Out 1918 of theseand 2.1.manufactured SAFT and Artsbatteries Energy for the luggage carts and lighting in locomotives. In 2006, Saft and Johnson inventions,manufactured those batteries with additives for the luggage and binders carts andare particularlylighting in locomotives.helpful in improving In 2006, Saftthe performanceand Johnson Controls (Milwaukee, WI, USA) formed a joint-venture pursuing batteries for electric vehicles (EV) 2.1.ofControls positive SAFTThe (Milwaukee, Sociétéand electrodes. Arts des Energy InWI,Accumulateurs the USA) negative formed electrode Fixes a joint-ventur et area, al SAFTTractione pursuing filed EPAs(SAFT) batteries on wasthe following forfounded electric subjects: invehicles 1918 active (EV)and manufacturedmaterials made batteries from a singlefor the phase luggage TiNi-based carts and alloy lighting [24], in a locomotives.Zr-based C14 In AB 2006,2 alloy Saft [25], and aJohnson mixed- The Société des Accumulateurs Fixes et al Traction (SAFT) was founded in 1918 and Controlsmetal based (Milwaukee, AB5 alloy WI,[26], USA) superlattice formed alloys a joint-ventur containinge pursuing Y[27], Mg[28], batteries or Zrfor (Ti)electric [29] vehiclesand A2B 7(EV) [30] manufactured batteries for the luggage carts and lighting in locomotives. In 2006, Saft and Johnson and A5B19 [31] phases, a catalytic substrate [32], a hydrophilic additive [33], and a paste process [34]. Controls (Milwaukee, WI, USA) formed a joint-venture pursuing batteries for electric vehicles (EV) Among these EPAs, the superlattice alloy-related patents lead to a new direction of material research in MH alloy field. SAFT filed multiple EPAs on the subject of a foam substrate and associated current collector design [35–41] (Figure 2), which built a strong foundation for further research in the area. In the separator area, SAFT filed EPAs on microporous grafted membranes [42,43], a tri-layer composite [44], a double-layer with different orientations [45], and a N-retaining substrate [46]. SAFT also filed three EPAs on a charging algorithm [47–49] and one on a leak-tight box for holding battery modules [50]. Batteries 2017, 3, 25 2 of 15

filed the first patent of using LaNi5 modified with Ti, Ca, Ba, Cr, and/or Cu with improved capacity as negative electrode material in 1978 [4]; and Johannes Willems, Johann van Beek, and Buschow Kurt from Philips (Eindhoven, Netherlands) filed a USA patent adding Co and/or Cu in LaNi5 to reduce the lattice expansion during hydride process and consequently extend the cycle life in 1984 [5]. In the past, we have reviewed the Ni/MH-related patents (or patents applications) filed in the USA [6], Japan [7], and China [8]. In this review, we focus on patent applications to the European Patent Office submitted by European companies; these applicants are grouped as battery manufacturers, metal hydride (MH) alloy suppliers, separator suppliers, and others. The patent applications can be found online through the website of World Intellectual Property Organization (WIPO) [9]. In the case of a non-English description, a machine translation option supplied by WIPO is available free of charge. A brief introduction of European companies contributing to the European Patent Application (EPA) Batteries 2017, 3, 25 3 of 16 is included in Table 1.

(a) (b)

(c)

Figure 1. Consumer Ni/MH battery market shares for (a) Sources in 2013, (b) Exports from China in Figure 1. Consumer Ni/MH battery market shares for (a) Sources in 2013, (b) Exports from China in 2013, and (c) Exports from Japan in February 2014. Data originate from [2]. 2013, and (c) Exports from Japan in February 2014. Data originate from [2].

Table 1. European companies related to Ni/MH battery manufacturing included in this review, in 2. Ni/MH Battery Manufacturer order of their presence.

PatentCompany applications from fiveProducts European Related battery/chemical companies related to the fabrication Headquarter Trademark Website of Ni/MHName batteries are reviewed into this Ni/MH section. There are two large European companies, Varta (Ellwangen, Germany) and SAFT (Bagnolet, France), that manufactured consumer-type Ni/MH batteries and submittedBagnolet, patent applications in related fields over the past two decades. In 2002, Varta Saft C, D, F-size cells http://saftbatteries.com/ microbattery spun offFrance from Varta and focused on the button cell business. In 2013, SAFT sold its Small Nickel Battery division to Arts Energy (Nersac, France). Alcatel (later merged into Lucent Technology, Paris, France) made Ni/MH batteries for cell phones and was active in filing patent applications. Nersac, http://www.arts- Recently,Arts Energy Nilar (Täby, Sweden) beganC, D, to F- offersize cells bi-polar prismatic Ni/MH batteries for transportation France energy.com applications. Hoppecke (Brilon-Hoppecke, Germany) made prismatic flooded-type Ni/MH batteries for transportation applications.Ellwangen, AAA to FA, http://www.varta- Varta Germany button cell microbattery.be/ 2.1. SAFT and Arts Energy Prismatic, bipolar Nilar Täby, Sweden http://www.nilar.com/ The Société des Accumulateurs Fixes etcell al Traction (SAFT) was founded in 1918 and manufactured batteries for the luggage carts and lighting in locomotives. In 2006, Saft and Johnson Controls (Milwaukee, WI, USA) formed a joint-venture pursuing batteries for electric vehicles (EV) and HEV. It was acquired by Total (Courbevoie, France) and delisted from the stock exchange in 2016. SAFT filed 24 and 19 European patent applications (EPAs) from 1990 to 2013 in the name of Accumulateurs Fixes and SAFT SA, respectively. In the positive electrode area, SAFT filed EPAs on the following subjects: a fabrication method of co-precipitated metal hydroxide [10], a description of characteristic of β-Ni(OH)2 [11], a fabrication method of pasted electrode [12,13], and uses of several additives including Celestine [14], CoO with a spinal structure [15], active carbon [16], Li(OH)2 [17], Ba(OH)2 and Sr(OH)2 [18], Nb2O5 [19], non-conductive fiber [20], and plastic binders [21–23]. Out of these inventions, those with additives and binders are particularly helpful in improving the performance of positive electrodes. In the negative electrode area, SAFT filed EPAs on the following subjects: active Batteries 2017, 3, 25 4 of 16

materials made from a single phase TiNi-based alloy [24], a Zr-based C14 AB2 alloy [25], a mixed-metal based AB5 alloy [26], superlattice alloys containing Y [27], Mg [28], or Zr (Ti) [29] and A2B7 [30] and A5B19 [31] phases, a catalytic substrate [32], a hydrophilic additive [33], and a paste process [34]. Among these EPAs, the superlattice alloy-related patents lead to a new direction of material research in MH alloy field. SAFT filed multiple EPAs on the subject of a foam substrate and associated current collector design [35–41] (Figure2), which built a strong foundation for further research in the area. In the separator area, SAFT filed EPAs on microporous grafted membranes [42,43], a tri-layer composite [44], a double-layer with different orientations [45], and a N-retaining substrate [46]. SAFT also filed three EPAs on a charging algorithm [47–49] and one on a leak-tight box for holding battery modules [50]. Batteries 2017, 3, 25 4 of 15

Batteries 2017, 3, 25 4 of 15

Figure 2. Schematics of three difference designs of current collectors by SAFT. The parts are 1: metal Figure 2. Schematics of three difference designs of current collectors by SAFT. The parts are 1: metal plate, 2: plug, 3: indent, 4: electrode [37]; 5: expanded metal or perorated metal strip [38]; 6: threaded plate,holes, 2: plug, 7: terminal 3: indent, assembly, 4: electrode 8: conducting [37]; 5: strip, expanded and 9: metalshoulder or perorated[40]. metal strip [38]; 6: threaded Figure 2. Schematics of three difference designs of current collectors by SAFT. The parts are 1: metal holes, 7: terminal assembly, 8: conducting strip, and 9: shoulder [40]. plate,Arts Energy2: plug, 3:filed indent, two 4: EPAs electrode in the [37]; early 5: expanded days; one metal on or the perorated re-sealable metal safety strip [38]; valve 6: threaded [51] and the holes, 7: terminal assembly, 8: conducting strip, and 9: shoulder [40]. other one on a battery cooling module design [52]. Arts Energy continues to perform research and Arts Energy ﬁled two EPAs in the early days; one on the re-sealable safety valve [51] and the other produce Ni/MH batteries after it was purchased from SAFT in 2013, but has not filed an EPA since one on a batteryArts Energy cooling filed module two EPAs design in the [52 early]. Arts days; Energy one on continues the re-sealable to perform safety valve research [51] andand producethe then. Its products are mainly cylindrical NiCd and Ni/MH batteries (Figure 3). Ni/MHother batteries one on a after battery it was cooling purchased module design from SAFT [52]. Arts in 2013, Energy but continues has not ﬁledto perform an EPA research since and then. Its productsproduce are mainlyNi/MH batteries cylindrical after NiCd it was and purchased Ni/MH from batteries SAFT (Figurein 2013,3 b).ut has not filed an EPA since then. Its products are mainly cylindrical NiCd and Ni/MH batteries (Figure 3).

Figure 3. Cylindrical cells from Arts Energy [53].

2.2. Varta and Varta Microbattery Figure 3. Cylindrical cells from Arts Energy [53]. Varta (originally VertriebFigure, Aufladung 3. Cylindrical, Reparatur cells from Transportabler Arts Energy Akkumulatoren [53]. ) was founded in 2.2.1887 Varta and producedand Varta Microbatterythe batteries that powered the first EV in Germany. For the production of Ni/MH batteries, Varta formed a joint-venture, 3C Alliance, with Toshiba (Tokyo, Japan) and Duracell Varta (originally Vertrieb, Aufladung, Reparatur Transportabler Akkumulatoren) was founded in (Bethel, CT, USA) in 1996. Varta filed 10 EPAs in 1994 and 1995, which cover an oxidation-resistant 1887 and produced the batteries that powered the first EV in Germany. For the production of Ni/MH graphite additive in the positive electrode [54,55], a use of foam or felt electrode in the button cell batteries, Varta formed a joint-venture, 3C Alliance, with Toshiba (Tokyo, Japan) and Duracell [56], a multi-segment cylindrical cell design [57] (Figure 4a), a button cell design [58,59] (Figure 4b), (Bethel, CT, USA) in 1996. Varta filed 10 EPAs in 1994 and 1995, which cover an oxidation-resistant Fe- [60], Ti(Zr)- [61] containing AB5 MH alloys, and metal recovery from spent batteries [62,63]. Out graphite additive in the positive electrode [54,55], a use of foam or felt electrode in the button cell of these EPAs, those related to the new cell structure designs are important to extend the applicability [56], a multi-segment cylindrical cell design [57] (Figure 4a), a button cell design [58,59] (Figure 4b), of Ni/MH into various fields. Fe- [60], Ti(Zr)- [61] containing AB5 MH alloys, and metal recovery from spent batteries [62,63]. Out of these EPAs, those related to the new cell structure designs are important to extend the applicability of Ni/MH into various fields. Batteries 2017, 3, 25 5 of 16

2.2. Varta and Varta Microbattery Varta (originally Vertrieb, Aufladung, Reparatur Transportabler Akkumulatoren) was founded in 1887 and produced the batteries that powered the first EV in Germany. For the production of Ni/MH batteries, Varta formed a joint-venture, 3C Alliance, with Toshiba (Tokyo, Japan) and Duracell (Bethel, CT, USA) in 1996. Varta filed 10 EPAs in 1994 and 1995, which cover an oxidation-resistant graphite additive in the positive electrode [54,55], a use of foam or felt electrode in the button cell [56], a multi-segment cylindrical cell design [57] (Figure4a), a button cell design [ 58,59] (Figure4b), Fe- [ 60], Ti(Zr)- [61] containing AB5 MH alloys, and metal recovery from spent batteries [62,63]. Out of these EPAs, those related to the new cell structure designs are important to extend the applicability of

Ni/MHBatteries into 2017 various, 3, 25 ﬁelds. 5 of 15

Batteries 2017, 3, 25 5 of 15

(a) (b) (c)

Figure 4. Schematics of (a) A multi-segment cylindrical cell, (b) A button cell, and (c) A hollow- Figure 4. Schematics of (a) A multi-segment cylindrical cell, (b) A button cell, and (c) A hollow-cathode cathode cylindrical cell from Varta. The parts are 1: terminal, 2: conducting pin, 3: positive electrode, cylindrical4: negative cell fromelectrode, Varta. 5: Theseparator, parts are6: central 1: terminal, hole [57]; 2: conducting7: pressure spring, pin, 3: 8: positive current electrode,collector plate, 4: negative 9: electrode,cover, 5:10: separator, gasket, 11: 6:negative central electrode, hole [57 12:]; 7: electrolyte pressure-saturated spring, 8:separator, current 13: collector positive plate, electrode, 9: cover, 14: 10:

gasket,case 11: [58]; negative 15: head, electrode, 16: disc(a) shape 12: electrolyte-saturated lid with (radialb) profile, separator, 17: rim (bent( 13:c) radially positive inward), electrode, 18: 14:seal, case 19: [58]; 15: head,separator, 16: disc 20: shapecylindrical lid with wall, radial 21: shank, profile, 22:thread, 17: rim 23: (bent negative radially elect inward),rode, 24: 18: can, seal, 25: 19:flat separator,circular 20: Figure 4. Schematics of (a) A multi-segment cylindrical cell, (b) A button cell, and (c) A hollow- bottom, 26: one positive electrode, 27: positive electrode assembly, 28: another segment of positive cylindricalcathode wall, 21:cylindrical shank, cell 22:thread, from Varta. 23:The negativeparts are 1: electrode,terminal, 2: conducting 24: can, 25: pin, flat 3: positive circular electrode, bottom, 26: one positiveelectrode, electrode,4: negative 29: cavity, 27: electrode, positive 30: screw 5: separator, electrode shape 6: current central assembly, collectorhole [57]; 28: another7:[64]. pressure segment spring, 8: ofcurrent positive collector electrode, plate, 9: 29: cavity, 30: screw shapecover, 10: current gasket, collector11: negative [ 64electrode,]. 12: electrolyte-saturated separator, 13: positive electrode, 14: In 2002,case Johnson [58]; 15: head, Controls 16: disc acquired shape lid thewith automotive radial profile, battery17: rim (bent division radially of inward),Varta. Immediately18: seal, 19: before the sale, Vartaseparator, Automotive 20: cylindrical GMGB wall, 21:filed shank, an 22:thread,EPA on 23:an negativeelectrolyte elect rode,containing 24: can, 25:soluble flat circular Al-compound Inadded 2002, in Johnsonthebottom, positive 26: Controls one electrode positive acquired electrode, to improve 27: the positive automotivehigh -electrodetemperature batteryassembly, charge division28: another acceptance ofsegment Varta. [65]. of positive Immediately before the sale, VartaVartaelectrode, Microbattery Automotive 29: cavity, was GMGB 30: ascrew spin filedshape-off compancurrent an EPA collectory onfrom an [64]. Varta electrolyte in 2002 containingand is now owned soluble by Al-compound Montana added in the positive electrode to improve high-temperature charge acceptance [65]. Tech ComponentsIn 2002, Johnson (Menziken, Controls Switzerland). acquired the automotiveTheir main battery products division are buttonof Varta. cells Immediately (Figure 5).before Between Varta1998 andthe Microbattery sale, 2015, Varta five AutomotiveEPAs was were a spin-off GMGB filed with filed company Vartaan EPA Microbattery fromon an electrolyte Varta as in the 2002containing assignee. and soluble is They now Al covered owned-compound the by areas Montana Techof Components a chargingadded in devicethe (Menziken, positive for Ni/MHelectrode Switzerland). battery to improve [66,67], Theirhigh a-temperature hollow main products-cathode charge cylindrical acceptance are button [65].cell cells design (Figure [64]5 (Figure). Between 1998 and4c), and 2015, a Vartabattery/supercapacitor five Microbattery EPAs were was filed a spin withcomposite-off Varta compan design Microbatteryy from [68,69]. Varta Thein as 2002 thecombination and assignee. is now ofowned They rechargeable by covered Montana battery the areas of Tech Components (Menziken, Switzerland). Their main products are button cells (Figure 5). Between a chargingand supercapacitor device for Ni/MH increases battery the high [66-rate,67 ],charg a hollow-cathodeing capability of cylindrical Ni/MH battery cell and design opens [64 the] (Figure door 4c), for some1998 power and 2015,-demanding five EPAs wereapplications. filed with Varta Microbattery as the assignee. They covered the areas and a battery/supercapacitorof a charging device for Ni/MH composite battery design [66,67], [a68 hollow,69].- Thecathode combination cylindrical cell of design rechargeable [64] (Figure battery and supercapacitor4c), and increases a battery/supercapacitor the high-rate composite charging design capability [68,69]. The of Ni/MHcombination battery of rechargeable and opens battery the door for some power-demandingand supercapacitor applications. increases the high-rate charging capability of Ni/MH battery and opens the door for some power-demanding applications.

Figure 5. Button cells from Varta Microbattery [70].

2.3. Alcatel Figure 5. Button cells from Varta Microbattery [70]. Figure 5. Button cells from Varta Microbattery [70]. Alcatel (originally short fir the Société Alsacienne de Constructions Atomiques, de 2.3. Alcatel Télécommunications et ďÉlectronique) was merged into CGE in 1966, which was later merged again with LucentAlcatel Technologies (originally in 2006 short and fir formed the Société Alcatel Alsacienne-Lucent. It de was Constructions finally merged Atomiques into the, de Nokia Télécommunications et ďÉlectronique) was merged into CGE in 1966, which was later merged again Group in 2016. Alcatel made Ni/MH batteries for cell phones and cordless phone (Figure 6). Between with Lucent Technologies in 2006 and formed Alcatel-Lucent. It was finally merged into the Nokia 1994 and 2003, Alcatel filed 8 EPAs under the names of Alsthom CGE Alcatel and CIT Alcatel. They Group in 2016. Alcatel made Ni/MH batteries for cell phones and cordless phone (Figure 6). Between disclosed1994 twoand 2003,designs Alcatel for metalfiled 8 currentEPAs under collectors the names [71,72] of Alsthom (Figure CGE 7), a Alcatelminus andΔV CITcut- Alcatel.off charge They control methoddisclosed [73], a two C14 designs AB2 MH for metal alloy current [74], a collectors coated, perforated[71,72] (Figure metal 7), a minussubstrate ΔV cut for-off a negativecharge control electrode [75], amethod double [73],-layered a C14 ABseparator2 MH alloy [76], [74], a cella coated, design perforated with a metalnegative/positive substrate for a rationegative >1.15 electrode [77], and a Ni(OH)[75],2 coating a double on-layered a MH separator alloy to [76],improve a cell lowdesign-temperature with a negative/positive and cycle performance ratio >1.15 [77], [78]. and Th a e last Ni(OH)2 coating on a MH alloy to improve low-temperature and cycle performance [78]. The last Batteries 2017, 3, 25 6 of 16

2.3. Alcatel Alcatel (originally short fir the Société Alsacienne de Constructions Atomiques, de Télécommunications et d’Électronique) was merged into CGE in 1966, which was later merged again with Lucent Technologies in 2006 and formed Alcatel-Lucent. It was finally merged into the Nokia Group in 2016. Alcatel made Ni/MH batteries for cell phones and cordless phone (Figure6). Between 1994 and 2003, Alcatel filed 8 EPAs under the names of Alsthom CGE Alcatel and CIT Alcatel. They disclosed two designs for metal current collectors [71,72] (Figure7), a minus ∆V cut-off charge control method [73], a C14 AB2 MH alloy [74], a coated, perforated metal substrate for a negative electrode [75], a double-layered Batteries 2017, 3, 25 6 of 15 separator [76], a cell design with a negative/positive ratio >1.15 [77], and a Ni(OH)2 coating on a MH alloyBatteries to 2017 improve, 3, 25 low-temperature and cycle performance [78]. The last EPA is very important for6 of the 15 EPA is very important for the use of Ni/MH battery in areas with very harsh winter, Siberia, for use of Ni/MH battery in areas with very harsh winter, Siberia, for example. example.EPA is very important for the use of Ni/MH battery in areas with very harsh winter, Siberia, for example.

Figure 6. Alcatel One Touch 535 with Ni/MH battery [79]. Figure 6. Alcatel One Touch 535 with Ni/MH battery [79]. Figure 6. Alcatel One Touch 535 with Ni/MH battery [79].

(a) (b)

(a) (b) Figure 7. Schematics of (a) A metal-foam connection and (b) A cylindrical cell design from Alcatel. TheFigure parts 7. Schematicsare 1: metal of strip, (a) A2: metalfoam -withoutfoam connection Ni(OH)2, and3: auxiliary (b) A cylindrical foam, 4: main cell designfoam, 5: from slot Alcatel.formed Figure 7. Schematics of (a) A metal-foam connection and (b) A cylindrical cell design from Alcatel. The byThe compression parts are 1: metal[71]; 6: strip, folded 2: partfoam of without can, 7: metalNi(OH) tab,2, 3:8: auxiliarynegative electrode,foam, 4: main 9: separator, foam, 5: slot10: positive formed parts are 1: metal strip, 2: foam without Ni(OH) , 3: auxiliary foam, 4: main foam, 5: slot formed by electrby compressionode, 11: can, [71]; 12: 6:a piecefolded of part nickel of can,plated 7: metal steel2 disc,tab, 8:13: negative adhesive electrode, tape, 14: 9:lug, separator, and 15: cover10: positive [72]. compression [71]; 6: folded part of can, 7: metal tab, 8: negative electrode, 9: separator, 10: positive electrode, 11: can, 12: a piece of nickel plated steel disc, 13: adhesive tape, 14: lug, and 15: cover [72]. 2.4. Nilarelectrode, 11: can, 12: a piece of nickel plated steel disc, 13: adhesive tape, 14: lug, and 15: cover [72]. 2.4. Nilar Nilar was founded in Sweden in 2011. Before moving to Sweden, Nilar used to operate its researchNilar facility was foundedin Aurora, in CO Sweden, USA. in Nilar’s 2011. Beforemain product moving is to a Sweden,prismatic, Nilar bi-polar used Ni/MH to operate battery its usedresearch in transportationfacility in Aurora, applications CO, USA. (Figure Nilar’s 8). main Nilar product owns 14is a USA prismatic, Patents bi covering-polar Ni/MH components, battery casing,used in assembly, transportation module applications construction (Figure of a 8). bi - Nilarpolar owns design 14 Ni/MH USA Patents battery. covering Nilar filed components, 13 EPAs betweencasing, assembly, 2002 and 201 module2, which construction included assembly of a bi-polar of bipolar design plates Ni/MH design battery. [80] and Nilar manufacture filed 13 EPAs [81], designbetween [82] 2002 and and manufacture 2012, which [83‒86] included of a assembly current collector, of bipolar a platescase [87], design a stacking [80] and arrangement manufacture [88], [81], a pressuredesign [82] sensor and manufacture[89], a powder [83‒86] reduction of a current unit [90], collector, a gasket a case design [87], [91], a stacking and an arrangement energy managing [88], a systempressure [92] sensor for bipolar [89], a Ni/MH powder batteries. reduction These unit bi [90],-polar a gasketNi/MH design batteries [91], are and very an important energy managing for large- scalesystem transportation [92] for bipolar application Ni/MH batteries.s, which These require bi -bothpolar large Ni/MH capacity batteries and are high very-rate important drain capability. for large- Recently,scale transportation Prof. Dag application Noréus fils,ed which an international require both Patent large capacity Cooperation and high Treaty-rate (PCT) drain withcapability. Nilar regardingRecently, the Prof. addition Dag Noréus of H2, O fil2,ed and/or an international H2O2 in sealed Patent Ni/MH Cooperation batteries to Treatyextend cycle (PCT) life with [93]. Nilar regarding the addition of H2, O2, and/or H2O2 in sealed Ni/MH batteries to extend cycle life [93]. Batteries 2017, 3, 25 7 of 16

2.4. Nilar Nilar was founded in Sweden in 2011. Before moving to Sweden, Nilar used to operate its research facility in Aurora, CO, USA. Nilar’s main product is a prismatic, bi-polar Ni/MH battery used in transportation applications (Figure8). Nilar owns 14 USA Patents covering components, casing, assembly, module construction of a bi-polar design Ni/MH battery. Nilar ﬁled 13 EPAs between 2002 and 2012, which included assembly of bipolar plates design [80] and manufacture [81], design [82] and manufacture [83–86] of a current collector, a case [87], a stacking arrangement [88], a pressure sensor [89], a powder reduction unit [90], a gasket design [91], and an energy managing system [92] for bipolar Ni/MH batteries. These bi-polar Ni/MH batteries are very important for large-scale transportation applications, which require both large capacity and high-rate drain capability. Recently, Prof. Dag Noréus ﬁled an international Patent Cooperation Treaty (PCT) with Nilar regarding the addition of H2,O2, and/or H2O2 in sealed Ni/MH batteries to extend cycle life [93]. Batteries 2017, 3, 25 7 of 15 Batteries 2017, 3, 25 7 of 15

(a) (b)

Figure 8. (a) Nilar’s (bipolara) prismatic Ni/MH batteries and (b) A ferry powered(b) by them [94]. Figure 8. (a) Nilar’s bipolar prismatic Ni/MH batteries and (b) A ferry powered by them [94]. Figure 8. (a) Nilar’s bipolar prismatic Ni/MH batteries and (b) A ferry powered by them [94]. 2.5. Hoppecke 2.5. Hoppecke 2.5. Hoppecke was founded in 1927 to produce industrial batteries. It supplied lead-acid, Ni/MH Hoppecke was founded in 1927 to produce industrial batteries. It supplied lead-acid, Ni/MH (FigureHoppecke 9), and Li was-ion foundedbatteries into 1927railway to produceapplications. industrial Hoppecke batteries. filed Ittwo supplied EPAs in lead 2011-acid, disclosing Ni/MH (Figure9), and Li-ion batteries to railway applications. Hoppecke ﬁled two EPAs in 2011 disclosing a(Figure positive 9), electrode and Li-ion manufacturing batteries to railway process applications. [95] and a flooded Hoppecke design filed for two a Ni/MH EPAs inbattery 2011 disclosing[96]. The a positive electrode manufacturing process [95] and a ﬂooded design for a Ni/MH battery [96]. The lattera positive is unusual electrode and manufacturingopens the way forprocess stationary [95] and storage a flooded associated design with for alternativea Ni/MH battery energies, [96]. such The latter is unusual and opens the way for stationary storage associated with alternative energies, such as aslatter solar is and unusual wind andpower. opens the way for stationary storage associated with alternative energies, such solar and wind power. as solar and wind power.

Figure 9. Prismatic flooded Ni/MH batteries from Hoppecke [97]. Figure 9. Prismatic flooded Ni/MH batteries from Hoppecke [97]. 3. MH Alloy SuppliersFigure 9. Prismatic ﬂooded Ni/MH batteries from Hoppecke [97]. 3. MHGfE Alloy (Nuremberg, Suppliers Germany ) and Treibacher (Althofen, Austria) were previously the only two EuropeanGfE (companiesNuremberg, producing Germany MH) and materials Treibacher used (Althofen, as active Austriamaterials) were in the previously negative electrodethe only two of Ni/MHEuropean battery. companies Nowadays, producing all the MH Ni/MH materials battery used manufacturers as active materials have switchedin the negative to vendors electrode from of JapanNi/MH and battery. China. Nowadays, all the Ni/MH battery manufacturers have switched to vendors from Japan and China. 3.1. GfE 3.1. GfE was founded in 1911 to produce metal products with electric furnaces. Today, it still offers an ABGfE2-based was MH founded alloy, in mainly 1911 to for produce the use metalof solid products hydrogen with storage electric [98]. furnaces. GfE filed Today, one EPS it still in offers1999 regardingan AB2-based addition MH alloy, of a metalmainly oxide for the (Cr use2O 3of, forsolid example) hydrogen to storagehydrogen [98]. storage GfE filed material one EPS (Mg, in 1999 for example)regarding as additiona catalyst of [99]. a metal oxide (Cr2O3, for example) to hydrogen storage material (Mg, for example) as a catalyst [99]. 3.2. Treibacher 3.2. Treibacher Industries AG was founded in 1898 to produce ferroalloy for the steel industry. Today,Treibacher it still offers Industries AB2 and AG ABwas5 MH founded alloys in 1898for hydrogen to produce storage ferroalloy and for battery the steel applications, industry. respectivelyToday, it still [100]. offers Treibacher AB2 and filed AB an5 EPAMH in alloys 2001 forto cover hydrogen a Cr -containing storage and AB battery5 MH alloy applications, [101]. It alsorespectively filed an international [100]. Treibacher PCT onfiled a two an -EPAchamber in 2001 hydrogen to cover stora a Crge-containing canister [102]. AB5 MH alloy [101]. It also filed an international PCT on a two-chamber hydrogen storage canister [102]. Batteries 2017, 3, 25 8 of 16

3. MH Alloy Suppliers GfE (Nuremberg, Germany) and Treibacher (Althofen, Austria) were previously the only two European companies producing MH materials used as active materials in the negative electrode of Ni/MH battery. Nowadays, all the Ni/MH battery manufacturers have switched to vendors from Japan and China.

3.1. GfE GfE was founded in 1911 to produce metal products with electric furnaces. Today, it still offers an AB2-based MH alloy, mainly for the use of solid hydrogen storage [98]. GfE ﬁled one EPS in 1999 regarding addition of a metal oxide (Cr2O3, for example) to hydrogen storage material (Mg, for example) as a catalyst [99].

3.2. Treibacher Treibacher Industries AG was founded in 1898 to produce ferroalloy for the steel industry. Today, it still offers AB2 and AB5 MH alloys for hydrogen storage and battery applications, respectively [100]. Treibacher ﬁled an EPA in 2001 to cover a Cr-containing AB5 MH alloy [101]. It also ﬁled an international PCT on a two-chamber hydrogen storage canister [102].

4. Separator Suppliers Scimat (Swindon, UK) and Freudenberg (Weinheim, Germany) were once two major separator companies making non-woven grafted polyethylene/polypropylene separators for Ni/MH battery producers worldwide. In 2006, Scimat was acquired by Freudenberg and, together, they still supply separators for high-performance Ni/MH batteries, especially in the HEV area. In 2015, Freudenberg also became the largest (75%) stockholder for Nippon Vilene—the top nonwoven producer in Japan.

4.1. Scimat Scimat was founded in 1987, focusing on the production and development of automated controlled separator production process. It was acquired by its main competitor, Freudenberg, in 2006. Between 1985 and 1998, Scimat filed 7 EPSs on a grafting method preparing microporous particles [103], a halopolymer film [104,105], a double-layer (one porous, the other one partially blocking the pores) membrane [106], a grafted sheet composed of copolymer and polyolefin [107], an ultraviolet radiation process to increase the surface hydrophilicity of the separator [108], and a laminate composed of fiber and vinyl monomer on the surface [109]. The Scimat separator is very important in the HEV application.

4.2. Freudenberg Freudenberg was founded in 1849 to make leather products. Combining the intellectual property and production capacity of past rivals Scimat and Nippon Vilene, Freudenberg became the only separator producer outside of China. Freudenberg filed 8 EPAs from 1993 to 2010, covering the subjects of a non-woven hydrophilic separator material [110], a grafting process making separator material from polymers [111], an addition of alkaline hydroxide or carbonate in the separator before use [112], a separator material containing a titrimetrically determined ammonia binding property [113], a chemically active separator material with an alkaline electrolyte [114], a bi-layer separator with different fiber diameters [115], a core-shell duel-component fiber as a separator [116], and a separator material with coating to enhance its puncturing resistance [117]. Together with Eveready Battery Company (St. Louis, MO, USA), Freudenberg filed an EPA on a cell design using a separator less than 0.15 mm thick in the dry state [118] (Figure 10). Batteries 2017, 3, 25 8 of 15

4.1. Scimat Scimat was founded in 1987, focusing on the production and development of automated controlled separator production process. It was acquired by its main competitor, Freudenberg, in 2006. Between 1985 and 1998, Scimat filed 7 EPSs on a grafting method preparing microporous particles [103], a halopolymer film [104,105], a double-layer (one porous, the other one partially blocking the pores) membrane [106], a grafted sheet composed of copolymer and polyolefin [107], an ultraviolet radiation process to increase the surface hydrophilicity of the separator [108], and a laminate composed of fiber and vinyl monomer on the surface [109]. The Scimat separator is very important in the HEV application.

4.2. Freudenberg Freudenberg was founded in 1849 to make leather products. Combining the intellectual property and production capacity of past rivals Scimat and Nippon Vilene, Freudenberg became the only separator producer outside of China. Freudenberg filed 8 EPAs from 1993 to 2010, covering the subjects of a non-woven hydrophilic separator material [110], a grafting process making separator material from polymers [111], an addition of alkaline hydroxide or carbonate in the separator before use [112], a separator material containing a titrimetrically determined ammonia binding property [113], a chemically active separator material with an alkaline electrolyte [114], a bi-layer separator with different fiber diameters [115], a core-shell duel-component fiber as a separator [116], and a separator material with coating to enhance its puncturing resistance [117]. Together with Eveready BatteriesBattery2017 Company, 3, 25 (St. Louis, MO, USA), Freudenberg filed an EPA on a cell design using a separator9 of 16 less than 0.15 mm thick in the dry state [118] (Figure 10).

FigureFigure 10.10. Schematic ofof aa cylindricalcylindrical cellcell designdesign fromfrom Eveready/Freudenberg.Eveready/Freudenberg. TheThe partsparts areare 1:1: negative currentcurrent collector,collector, 2: 2: negativenegative terminal,terminal, 3: 3: metalmetal plate,plate, 4:4: polymerpolymer seal,seal, 5:5: metalizedmetalized plasticplastic ﬁlm,film, 6:6: steelsteel can,can, 7:7: tubulartubular positivepositive electrode,electrode, 8:8: separator, 9:9: negative electrode, 10:10: bottom of negative electrode, 11:11: bottombottom ofof foldingfolding cylinder,cylinder, 12:12: positivepositive terminal,terminal, andand 13:13: foldingfolding cancan [[118].118].

5.5. OtherOther CompaniesCompanies InIn additionaddition to the the companies companies mentioned mentioned above, above, which which are are (or (or were) were) involved involved directly directly with with the themanufac manufacturingturing of Ni/MH of Ni/MH batteries, batteries, there there are other are other companies companies and anduniversities universities in Europe in Europe that thatoccasionally occasionally applied applied for for EPAs EPAs in in the the Ni/MH Ni/MH battery battery field. field. In In battery battery design, Deutsche Deutsche AutomobilgesellschaftAutomobilgesellschaft (now a subsidiary subsidiary of Daimler Daimler AG, Stuttgart, Stuttgart, Germany) filedfiled 3 EPAsEPAs on on a a prismaticprismatic cell cell [ 119[119]] with with the the negative negative electrode electrode covered covered by polytetrafluoroethylene by polytetrafluoroethylene (PTFE) (PTFE) threads threads [120], and[120], a bi-polarand a bi- designpolar design of electrode of electrode stacking stacking [121]. [121]. In the Ni(OH)2 area, the University of Southampton (Southampton, UK) filed one EPA [122] and In the Ni(OH)2 area, the University of Southampton (Southampton, UK) filed one EPA [122] andtwo twoPCTs PCTs [123,124] [123, 124on the] on subject the subject of a porous of a porous positive positive electrode electrode active activematerial material with regular with regularlyly spaced spaced pores. In the MH alloy area, Höganäs AB (Höganäs, Sweden) filed two EPAs on an organically modified silicic acid coating for MH alloys [125], and MH alloys prepared by gas atomization with a unique dendritic microstructure [126]. Fraunhofer-Gesellschaft (Munich, Germany) also filed an EPA on an organically modified silicic acid polycondensated coating for MH alloys [127]. In the charging algorithm and devices, Peugeot (Paris, France) presented a method relating to inner pressure to the state-of-charge (SOC) [128]; Friwo Geräetebau (Ostbevern, Germany) patented a temperature sensor equipment charging device [129]; SGS Thomson Microelectronics (Geneva, Switzerland) disclosed a −∆V cut-off method [130,131]; and Solarc Innovative Solarprodukte (Berlin, Germany) disclosed a solar-cell compatible battery charging unit [132]. EU countries are very concerned about battery recycling activities [133]. A special program, COLABATS, was initiated in Europe in 2013 to conduct the development of recycling technology for Ni/MH and Li-ion batteries [134]. In terms of battery recycling, Umicore (Brussels, Belgium) patented a smelting process to reclaim Ni and Co [135]; Montanuniversität Leoben (Leoben, Austria) disclosed a method of reclaiming rare earth metals by using a non-oxidizing acid [136]; Akkuser Ltd. (Nivala, Finland) has a Patent issued on the separation of spent batteries by chopping or crushing followed by a refining or smelting process [137]; CT Umwelttechnik AG (Winterthur, Switzerland) patented a recycling process for the mixture of various kind of batteries [138]; Titalyse S.A. (Croix-de-Rozon, Switzerland) patented an apparatus to sort spent batteries with different size and shape by an optical camera with imaging software [139]; Enviro EC AG (Zug, Switzerland) published a method of reclaiming MH from spent batteries by magnetic separation [140]; SNAM (Saint-Quentin-Fallavier, France) also reclaimed MH by spraying surfactant and later sedimentation [141]; and Eco Recycling SRL (Rome, Italy) reported a physical/chemical combinational method to reclaim Cu and plastic materials [142]. Additionally, French Alternative Energies and Atomic Energy Commission (Gif-sur-Yvette, France) filed a PCT on a process to reclaim rare earth elements, specifically Ni, Co, Mn, and Fe, by selective salt precipitation from a mixture of acid solution for spent Ni/MH battery [143]. Finally, only one EPA was found for the application of Ni/MH batteries, a low self-discharge battery used in soap dispensers filed by Vivian Blick [144]. Batteries 2017, 3, 25 10 of 16

6. Comparisons to Other Countries The development of MH alloy and associated Ni/MH battery started from European companies, such as Battelle, Philips, Benz (Stuttgart, Germany) and followed by the successful commercialization by American and Japanese companies [145]. Now the Ni/MH batteries are mainly fabricated in China and Japan. Throughout the years, many important patents were filed in these four areas/countries, namely EU, USA, Japan, and China. The nature of these patent applications is compared in Table2. Compared to other area/countries, European companies filed the fewest patents (application) in the Ni/MH field. However, their patents in areas such as button cells (owned by Varta Micronbattery), bi-polar design (owned by Nilar), and separators (owned by SciMat and now Freudenberg) are all very important. USA has the largest consumer market in the world and most of its patents related to Ni/MH batteries were filed by Japanese and European companies.

Table 2. Comparison of numbers of patents (applications) ﬁled in EU, USA, Japan, and China and number of associated companies (institutes). * The number of companies used in USA only counts for American companies (institutes).

Country EU USA Japan China Number of patents (application) related to Ni/MH 126 371 275 692 Number of patents in negative electrode 22 58 128 136 Number of patents in positive electrode 18 54 27 83 Number of patents in manufacturing technology 10 33 28 104 Number of companies (institutes) ﬁled patents 29 18 * 46 99

7. Conclusions A total of 126 patent applications related to Ni/MH batteries and filed by European companies to the European Patent Office were reviewed. The scope covers metal hydride formulations and processing, nickel hydroxide preparation, electrode fabrication, cell design, charging method, and recycling. Together with reviews of patents (applications) in the Ni/MH field filed in the USA, Japan, and China, this work completes our studies on the intellectual properties in this field. Compared to companies (institutes) in other countries, European companies started the Ni/MH battery, but were not as active in the development of the production technology. They still made significant contributions in the separator and prismatic cell areas.

Author Contributions: Shiuan Chang collected the information. Kwo-Hsiung Young and Yu-Ling Lien prepared the manuscript. Conﬂicts of Interest: The authors declare no conﬂict of interest.

Abbreviations The following abbreviations are used in this manuscript:

Ni/MH Nickel/metal hydride HEV Hybrid electric vehicle MH Metal hydride WIPO World Intellectual Property Organization EPA European Patent Application EV Electric vehicle PCT Patent Cooperation Treaty PTFE Polytetraﬂuoroethylene SOC State-of-charge Batteries 2017, 3, 25 11 of 16

References

1. Battery and Energy Technologies. Available online: http://www.mpoweruk.com/nimh.htm (accessed on 25 May 2017). 2. Bai, W. The Current Status and Future Trends of Domestic and Foreign NiMH Battery Market. Available online: http://cbea.com/u/cms/www/201406/06163842rc0l.pdf (accessed on 25 May 2017). 3. Beccu, K.-D. Electrical Accumulator with a Metal Hydride Serving as the Cathodic Reactive Material Arranged in Suspension in the Electrolyte. U.S. Patent 3,520,728, 14 July 1970. 4. Percheron-Guégen, A.; Achard, J.C.; Loriers, J.; Bonnemay, M.; Bronoël, G.; Sarradin, J.; Schlapbach, L. Electrode Materials Based on Lanthanum and Nickel, and Electrochemical Uses of Such Materials. U.S. Patent 4,107,405, 15 August 1978. 5. Willems, J.J.G.S.A.; van Beek, J.R.G.C.M.; Buschow, K.H.J. Electrochemical cell comprising stable hydride-forming material. U.S. Patent 4,487,817, 11 December 1984. 6. Chang, S.; Young, K.; Nei, J.; Fierro, C. Reviews on the U.S. Patents regarding nickel/metal hydride batteries. Batteries 2016, 2, 10. [CrossRef] 7. Ouchi, T.; Young, K.; Moghe, D. Reviews on the Japanese Patent Applications regarding nickel/metal hydride batteries. Batteries 2016, 2, 21. [CrossRef] 8. Young, K.; Cai, X.; Chang, S. Reviews on the Chinese Patent regarding Nickel/metal hydride battery. Batteries 2017, 3, 24. [CrossRef] 9. World Intellectual Property Organization. Available online: https://patentscope.wipo.int/search/en/search. jsf (accessed on 23 May 2017). 10. Blanchard, P.; Klein, J.P. Process for the Preparation of a Metal Hydride Powder and the Powder Obtained. Eur. Pat. Appl. 91401640, 18 June 1991. 11. Bernard, P.; Audry, C.; Lecerf, A.; Senyarich, S. Nickel Electrode for Alcaline Accumulator. Eur. Pat. Appl. 96400423, 28 February 1996. 12. Bernard, P.; Dennig, C.; Cocciantelli, J.-M.; Coco, I.; Alcorta, J. Non-Sintered Nickel Electrode. Eur. Pat. Appl. 99400049, 11 January 1999. 13. Bernard, P.; Simonneau, O.; Bertrand, F. Pasted Nickel Electrode. Eur. Pat. Appl. 97401011, 5 May 1997. 14. Bernard, P.; Goubault, L.; Guiader, O. Positive Electrode for an Electrochemical Generator with an Alkaline Electrolyte. Eur. Pat. Appl. 08290869, 16 September 2008. 15. Bernard, P.; Audry, C. Conductive Material for Electrode of Secondary Battery with Alkali Electrolyte. Eur. Pat. Appl. 01401672, 25 June 2001. 16. Chevalier, S.; Debdary, M.; Desprez, P. Negative Electrode for an Asymmetric Supercapacitor with Nickel Hydroxide Positive Electrode and Alkali Electrolyte and Method for Manufacturing Same. Eur. Pat. Appl. 12167763, 11 May 2012. 17. Bernard, P.; Baudry, M.; Jan, O.; Audry, C. Non-Sintered Nickel Electrode for Secondary Battery with Alkali Electrolyte. Eur. Pat. Appl. 99403260, 23 December 1999. 18. Bernard, P.; Goubault, L.; Hezeque, T. Electrochemical Alkaline Generator with Improved Service Life. Eur. Pat. Appl. 05291300, 17 June 2005. 19. Bernard, P.; Goubault, L.; Gillot, S. Electrode for Alkaline Storage Battery. Eur. Pat. Appl. 12175342, 6 July 2012. 20. Bernard, P. Positive Electrode for Alkaline Battery. Eur. Pat. Appl. 06291402, 5 September 2006. 21. Coco, I.; Cocciantelli, J.-M.; Villenave, J.-J. Electrode of non Sintered Type for Accumulator with Alkaline Electrolyte. Eur. Pat. Appl. 97401723, 17 July 1997. 22. Bernard, P.; Goubault, L. Plastiﬁed Electrode for Alkaline Battery. Eur. Pat. Appl. 07848215, 11 September 2007. 23. Bernard, P.; Goubault, L.; Gillot, S.; Feugnet, T. Plastic-Coated Electrode for Alkaline Storage Battery. Eur. Pat. Appl. 10162920, 17 May 2010. 24. Bouet, J.; Knosp, B.; Percheron-Guegan, A.; Jordy, C. Hydridable Material for a Nickel-Hydride Battery Negative Electrode and Process for Production. Eur. Pat. Appl. 93401399, 2 June 1993. 25. Bouet, J.; Knosp, B.; Percheron-Guegan, A.; Canet, O. Hydridable Material for a Nickel-Hydride Battery Negative Electrode. Eur. Pat. Appl. 93402198, 9 September 1993. Batteries 2017, 3, 25 12 of 16

26. Bouet, J.; Knosp, B.; Percheron-Guegan, A.; Cocciantelli, J.-M. Hydridable Material for Nickel-Hydride Accumulator Negative Electrode. Eur. Pat. Appl. 0608646, 3 August 1994. 27. Bernard, P.; Knosp, B.; Baudry, M. Composition for Negative Electrode of Accumulator with Alkaline Electrolyte. Eur. Pat. Appl. 07291035, 23 August 2007. 28. Lavaud, C.; Dillay, V.; Bernard, P. Negative Active Material for Hydride metal Nickel Accumulator. Eur. Pat. Appl. 08012162, 4 July 2008. 29. Bernard, P.; Knosp, B.; Latroche, M.; Zhang, J.; Serin, V.; Hytch, M. Active Material for a Negative Electrode of a Nickel-Metal Hydride Alkaline Accumulator. Eur. Pat. Appl. 11188182, 8 November 2011. 30. Bernard, P.; Knosp, B.; Baudry, M. Active Material Composition and Alkaline Electrolyte Accumulator. Eur. Pat. Appl. 06290808, 18 May 2006. 31. Bernard, P.; Knosp, B.; Latroche, M.; Ferey, A. Hydridable Alloy for Alkaline Storage Battery. Eur. Pat. Appl. 07290197, 16 February 2007. 32. Senyarich, S.; Cocciantelli, J.-M. Hydrophylic Electrode for Alkaline Accumulator and Method of Preparation. Eur. Pat. Appl. 97402510, 23 October 1997. 33. Sjövall, R.; Greis, M. Low Maintenance Alkaline Electrochemical Cell. Eur. Pat. Appl. 12190882, 31 October 2012. 34. Coco, I.; Cocciantelli, J.-M.; Villenave, J.-J. Negative Electrode for Ni-Metal Hydride Accumulator. Eur. Pat. Appl. 96400850, 22 April 1996. 35. Grange-Cossou, M.; Torregrossa, W. Process of Manufacturing an Electrode with Spongiform Support for Electrochemical Generator and Electrode Obtained Thereby. Eur. Pat. Appl. 90117834, 17 September 1990. 36. Caillon, G.; Lebarbier, C. Method for Covering an Electrode with a Sponge like Support for Electrochemical Generator and Electrode Obtained by This Process. Eur. Pat. Appl. 90121037, 2 November 1990. 37. Guerinault, J.-M.; Brunarie, J. Method for Joining a Metallic Current Collector to an Electrode Comprising a Spongeous Supporting Structure for Electrochemical Generator and Electrode Obtained Thereby. Eur. Pat. Appl. 91121081, 9 December 1991. 38. Grange-Cossou, M.; Guerinault, J.-M.; Carteau, B.; Brunarie, J. Method for Joining a Metallic Collector to an Electrode Comprising a Spongeous Supporting Structure for Electrochemical Generator and Electrode Obtained Thereby. Eur. Pat. Appl. 92401446, 26 May 1992. 39. Bouet, J.; Pichon, B. Process for Making a Foam-Type Support for an Electrode of a Secondary Battery. Eur. Pat. Appl. 92401861, 30 June 1992. 40. Fradin, J. Cylindrical Electrochemical Generator with Spirally Wounded Electrodes. Eur. Pat. Appl. 97401780, 24 July 1997. 41. Goubault, L.; Bernard, P.; Gillot, S. Plastic-Coated Electrode for Alkaline Storage Battery. Eur. Pat. Appl. 14170069, 27 May 2014. 42. Gineste, J.-L.; Pourcelly, G.; Brunea, J.; Perton, F.; Broussely, M. Grafted Microporous Separator for Electrochemical Generator and Its Manufacturing Process. Eur. Pat. Appl. 93402037, 10 August 1993. 43. Caillon, G.; Crochepierre, B. Alkaline Open Battery Comprising a Microporous Membrane. Eur. Pat. Appl. 06290869, 30 May 2006. 44. Green, A.; Champalle, P.; Liska, J.-L. Separator for Alkaline Accumulator. Eur. Pat. Appl. 91402721, 11 October 1991. 45. Senyarich, S.; Leblanc, P. Separator for Accumulator with Spirally Wounded Electrodes and Alkaline Electrolyte. Eur. Pat. Appl. 97401667, 10 July 1997. 46. Senyarich, S.; Viaud, P. Alkaline Electrolyte Secondary Battery. Eur. Pat. Appl. 97402264, 29 September 1997. 47. Berlureau, T.; Liska, J.-L. Method for Charging Maintenance-Free Nickel Metal Hydride Batteries. Eur. Pat. Appl. 98400455, 26 February 1998. 48. Berlureau, T.; Bariand, M.; Liska, J.-L. Method for Controlling the Rapid Charging of an Alkaline Electrolyte Industrial Accumulator. Eur. Pat. Appl. 99401903, 26 July 1999. 49. Gardes, F.; Juan, A.; Maloizel, S. Method for Managing the Charge of a Battery. Eur. Pat. Appl. 08291208, 18 December 2008. 50. Vasti, P.; Tridon, X. Leaktight Box for Alkaline Batteries. Eur. Pat. Appl. 13773814, 9 October 2013. 51. Payen, S.; Raymond, A. A Resealable Valve and Electrochemical Generator Comprising Said Valve. Eur. Pat. Appl. 01402994, 22 November 2001. Batteries 2017, 3, 25 13 of 16

52. Vigier, N.; Besse, S. Electrochemical Generator with Surface of Revolution. Eur. Pat. Appl. 03290969, 18 April 2003. 53. Arts Energy. Available online: http://www.arts-energy.com/ (accessed on 25 May 2017). 54. Lichtenberg, F.; Kleinsorgen, K.; Hofmann, G. Nickel/Metallic Hydride Secondary Cell. Eur. Pat. Appl. 94116439, 19 October 1994. 55. Lichtenberg, F.; Kleinsorgen, K.; Hofmann, G. Electrical Nickel-Metal Hydride Accumulator with Electrode of Nickelhydroxide Comprising Graphite. Eur. Pat. Appl. 94115951, 10 October 1994. 56. Klaus, C. Gastight Alkaline Button-Type Accumulator. Eur. Pat. Appl. 94116622, 21 October 1994. 57. Klaus, C.; Simon, G.; Koehler, U.; Kannler, H. Gastight Nickel/Hydride-Accumulation of Round Cell Type. Eur. Pat. Appl. 95194924, 18 March 1995. 58. Koehler, U.; Chen, G.; Lindner, J. Gastight Metaloxide-Metalhydride Accumulator. Eur. Pat. Appl. 95106832, 5 May 1995. 59. Koehler, U.; Klaus, C.; Hofmann, G.; Lichtenberg, F. Alkaline Gastight Accumulator in the Shape of a Button Cell. Eur. Pat. Appl. 95106833, 5 May 1995. 60. Lichtenberg, F.; Koehler, U.; Kleinsorgen, K.; Foelzer, A.; Bouvier, A. Alkaline Metal Oxide, Metal Hydride Battery. Eur. Pat. Appl. 96102419, 17 February 1996. 61. Lichtenberg, F. Alloys for Use as Active Material for the Negative Electrode of an Alkaline, Rechargeable, Nickel Metal-Hybride Battery and Its Method of Preparation. Eur. Pat. Appl. 96110281, 26 June 1996. 62. Kleinsorgen, K.; Koehler, U.; Bouvier, A.; Foelzer, A. Process for Recovery of Metals from Used Nickel-Metal Hydride Accumulators. Eur. Pat. Appl. 95940265, 1 December 1995. 63. Kleinsorgen, K.; Koehler, U.; Bouvier, A.; Foelzer, A. Process for Recovery of Metals from Used Nickel-Metal Hydride Accumulators. Eur. Pat. Appl. 95941642, 1 December 1995. 64. Brenner, R. Electrochemical Cell with a Positive Electrode in the Form of a Hollow Cylinder and a Negative Electrode Assembled Therein. Eur. Pat. Appl. 13178468, 30 July 2013. 65. Baeuerlein, P. Nickel-Metal Hydride Secondary Battery. Eur. Pat. Appl. 01116524, 7 July 2001. 66. Knop, I. Charging Device Adapted for Charging NiMeH Batteries. Eur. Pat. Appl. 98102036, 6 February 1998. 67. Schein, H.; Kron, N.; Ilic, D. Mobile Charger for Charging Secondary Batteries from Secondary Batteries. Eur. Pat. Appl. 06776545, 2 August 2006. 68. Schula, C.; Scholz, S.; Pytlik, E.; Ensling, D. Secondary Electrochemical Cell and Charging Method. Eur. Pat. Appl. 15735963, 9 July 2015. 69. Schula, C.; Scholz, S.; Pytlik, E.; Ensling, D. Secondary Electrochemical Cell and Charging Method. Eur. Pat. Appl. 15735964, 9 July 2015. 70. VARTA. Available online: http://www.varta-microbattery.com (accessed on 25 May 2017). 71. Loustau, M.-T.; Verhoog, R.; Precigout, C. Method for Joining a Metallic Current Collector to an Electrode Comprising a Fibrous or a Spongeous Supporting Structure for Electrochemical Generator and Electrode Obtained Thereby. Eur. Pat. Appl. 94401155, 25 May 1994. 72. Amiel, O.; Belkhir, I.; Freluche, J.-P.; Pineau, N.; Dupuy, C.; Babin, S. Non-Sintered Electrode with Tridimensional Support for Secondary Battery with Alcaline Electrolyte. Eur. Pat. Appl. 00403112, 9 November 2000. 73. Cuesta, R.; Rouverand, C. Charge Control Method of a Sealed Nickel Storage Cell and Charger Therefor. Eur. Pat. Appl. 94401127, 20 May 1994. 74. Knosp, B.; Mimoun, M.; Bouet, J.; Gicquel, D.; Jordy, C. Hydridable Material for Nickel-Hydride Accumulator Negative Electrode. Eur. Pat. Appl. 95400803, 10 April 1995. 75. Cypel, L. Metal Hydride Negative Electrode Comprising a Coated Perforated Sheet. Eur. Pat. Appl. 98401150, 14 May 1998. 76. Senyarich, S.; Viaud, P. Alkaline Electrolyte Secondary Battery, Particularly of the Type nickel-Cadmium or Nickel Metal Hydride. Eur. Pat. Appl. 98402291, 17 September 1998. 77. Berlureau, T.; Liska, J.-L. Sealed Nickel-Metal Hydride Storage Battery. Eur. Pat. Appl. 00402019, 13 July 2000. 78. Bernard, P.; Goubault, L.; Le, G.L. Electrochemically Active Material for Negative Electrode of an Alkaline Electrolyte Secondary Battery. Eur. Pat. Appl. 03290119, 17 January 2003. 79. Alcatel-Lucent. Available online: https://en.wikipedia.org/wiki/Alcatel-Lucent (accessed on 29 July 2017). 80. Fredriksson, L.; Puester, N. A Method for Manufacturing a Biplate Assembly, a Biplate Assembly and a Bipolar Battery. Eur. Pat. Appl. 02746283, 8 July 2002. Batteries 2017, 3, 25 14 of 16

81. Hug, L.; Puester, N.H.; Fredriksson, L. An Apparatus for Manufacturing an Electrode. Eur. Pat. Appl. 03770206, 7 November 2003. 82. Fredriksson, L.; Puester, N. A Bipolar Battery and a Biplate assembly. Eur. Pat. Appl. 02798876, 13 September 2002. 83. Fredriksson, L.; Puester, N. A Bipolar Battery, a Method for Manufacturing a Bipolar Battery and a Biplate Assembly. Eur. Pat. Appl. 02798875, 13 September 2002. 84. Fredriksson, L.; Puester, N.H. An Electrode, a Method for Manufacturing an Electrode and a Bipolar Battery. Eur. Pat. Appl. 03810729, 7 November 2003. 85. Fredriksson, L.; Puester, N.H. A Bipolar Battery and a Method for Manufacturing a Bipolar Battery. Eur. Pat. Appl. 03812398, 7 November 2003. 86. Hock, D.; Puester, N.; Fredriksson, L. A Method for Manufacturing a Bipolar Battery with a Gasket. Eur. Pat. Appl. 04800257, 3 November 2004. 87. Jensen, K.; Puester, N.; Hock, D. A Casing for a Sealed Battery. Eur. Pat. Appl. 06717032, 20 March 2006. 88. Fredriksson, L.; Puester, N.H.; Howlett, R. A Battery Stack Arrangement. Eur. Pat. Appl. 07703860, 15 January 2007. 89. Fredriksson, L.; Howlett, R. A Bipolar Battery Including a Pressure Sensor. Eur. Pat. Appl. 07712225, 15 February 2007. 90. Fredriksson, L.; Puester, N.H. A System for Reducing the Power in a Battery Stack Arrangement. Eur. Pat. Appl. 07852114, 17 December 2007. 91. Hock, D.; Fredriksson, L.; Puester, N.H. A Gasket, a Bipolar Battery and a Method for Manufacturing a Gasket. Eur. Pat. Appl. 08712719, 18 February 2008. 92. Howlett, R. An Energy Management System. Eur. Pat. Appl. 12738289, 28 June 2012. 93. Noréus, D. A Metal Hydride Battery with Added Hydrogen Gas, Oxygen Gas or Hydrogen Peroxide. International Application No. PCT/SE2016/051020, 27 April 2017. 94. Nilar. Available online: http://www.nilar.com (accessed on 25 May 2017). 95. Schaffrath, U.; Ohms, D.; Benczur-Uermoessy, G.; Markolf, R.; Schmelter, K. Method for Producing a Positive Nickel-Hydroxide Electrode for a Nickel-Metal Hydrid or Nickel-Cadmium Battery. Eur. Pat. Appl. 11007464, 14 September 2011. 96. Ohms, D.; Schaedlich, G.R.N.; Kleinschnittger, B.D.-I.; Markolf, R.; Schmelter, K. Nickel-Metal Hydrid Battery. Eur. Pat. Appl. 11007465, 14 September 2011. 97. Hoppecke Power from Innovation. Available online: https://www.hoppecke.com/ (accessed on 25 May 2017). 98. Master Alloys. Available online: http://www.gfe.com/ﬁleadmin/user_upload/pdfs/Produkt speziﬁkationen_Alloys/HYDRALLOY_C_2004732_2005169_2019929_V4.pdf (accessed on 25 May 2017). 99. Klassen, T.; Bormann, R.; Oelerich, W.; Guether, V.; Otto, A. Metalliferous Storage Material for Hydrogen and Method for Producing Same. Eur. Pat. Appl. 99955727, 17 September 1999. 100. Non-Ferrous Metal Alloys. Available online: https://www.treibacher.com/en/products/non-ferrous-metal- alloys.html (accessed on 25 May 2017). 101. Knosp, B.; Arnaud, O.; Hezeque, T.; Barbic, P.; Bouvier, A. Hydridable Alloy. Eur. Pat. Appl. 01402059, 30 July 2001. 102. Hebenstreit, G.; Barbic, P. Metal Hydride Reservoir. International Application No. PCT/AT2006/000241, 28 December 2006. 103. Dubrow, R.S.; Froix, M.F. Method of Making a Microporous Article. Eur. Pat. Appl. 85902861, 20 May 1985. 104. Park, G.B.; Cook, J.A. Microporous Films. Eur. Pat. Appl. 90112666, 18 December 1985. 105. Dorling, M.G.L.; Barker, D.J.; Mcloughlin, R.H. Microporous Films. Eur. Pat. Appl. 89906800, 13 June 1989. 106. Singleton, R.W.; Cook, J.A.; Gargan, K. Polymer Membrane. Eur. Pat. Appl. 91916836, 19 September 1991. 107. Gargan, K.; Singleton, R.W.; Cook, J.A. Polymeric Sheet. Eur. Pat. Appl. 92914965, 9 July 1992. 108. Mcloughlin, R.H.; Gentilcore, G.; Cook, J.A. Non-Woven Fabric Treatment. Eur. Pat. Appl. 98925861, 8 June 1998. 109. Gentilcore, G.; Lancaster, I.M. Non-Woven Fabric Laminate. Eur. Pat. Appl. 98925860, 8 June 1998. 110. Hoffmann, H.; Schwoebel, R. Nonwoven Hydrophilic Material for Electrochemical Battery Separator and Method of Manufacturing. Eur. Pat. Appl. 93109577, 16 June 1993. Batteries 2017, 3, 25 15 of 16

111. Wenneis, W.; Hoffmann, H.; Severich, B.; Keul, H.R.N. Alkaline Cell or Battery. Eur. Pat. Appl. 02009348, 3 May 2002. 112. Kritzer, P.; Trautmann, C. Hydrophylized Separator Material. Eur. Pat. Appl. 02023842, 24 October 2002. 113. Kritzer, P.; Schwoebel, R.-P. Method for the Production of a Separator Material for Alkaline Batteries. Eur. Pat. Appl. 03003011, 12 February 2003. 114. Kritzer, P.; Feistner, H.-J.; Schilling, H.; Kalbe, M. Nonwoven Fabric, Fiber and Electrochemical Cell. Eur. Pat. Appl. 05023520, 27 October 2005. 115. Kritzer, P. Separator for Housing in Batteries and Battery. Eur. Pat. Appl. 07006211, 27 March 2007. 116. Kritzer, P.; Schilling, H. Layer with Insulated Fibres and Electrochemical Cell. Eur. Pat. Appl. 07020102, 15 October 2007. 117. Roth, M.; Weber, C.; Berg, M.; Geiger, S.; Hirn, K.; Waschinski, C.; Falusi, S.; Kasai, M. Separator with Increased Puncture Resistance. Eur. Pat. Appl. 10749599, 11 August 2010. 118. Audebert, J.-F.; Feistner, H.-J.; Frey, G.; Farer, R.; Thrasher, G.L.; Weiss, M. Nonwoven Separator for Electrochemical Cell. Eur. Pat. Appl. 02789528, 8 November 2002. 119. Benczur-Uermoessy, G. Gastight Prismatic Nickel-Metal Hydride cell. Eur. Pat. Appl. 00942051, 10 June 2000. 120. Benczur-Uermoessy, G.; Ohms, D.; Waidelich, D. Electrode Capable of Storing Hydrogen and a Method for the Production of the Same. Eur. Pat. Appl. 00942050, 10 June 2000. 121. Benczur-Uermoessy, G.; Gensierich, M.; Ohms, D.; Wiesener, K. Battery in Bipolar Stacked Configuration and Method for the Production Thereof. Eur. Pat. Appl. 00927157, 6 May 2000. 122. Bartlett, P.N.; Owen, J.R.; Nelson, P.A. Electrochemical Cell. Eur. Pat. Appl. 03767996, 12 December 2003. 123. Bartlett, P.N.; Owen, J.R.; Nelson, P.A. Electrochemical Cell. International Application No. PCT/GB2003/ 005441, 28 October 2004. 124. Bartlett, P.N.; Owen, J.R.; Nelson, P.A. Electrochemical Cell Suitable for Use in Electronic Device. International Application No. PCT/GB2003/005442, 24 July 2004. 125. Bruchmann, B.; Klok, H.; Scholl, M.T. Preparation and Use of Modified Polylysines. Eur. Pat. Appl. 10152919, 15 November 2006. 126. Arvidsson, J.; Carlström, R.; Hallen, H.; Löfgren, S. Powder Composition and Process for the Preparation Thereof. Eur. Pat. Appl. 98928768, 5 June 1998. 127. Popall, M.; Olsowski, B.; Cochet, S. Particles Coated with an Organically Modified (Hetero) Silicic Acid Polycondensate and Containing a Metal Core Suited for Storing Hydrogen, Batteries Produced Therewith and Method for the Production Thereof Using the Particles. Eur. Pat. Appl. 10726978, 29 June 2010. 128. Maugy, C.; Porcellato, D.; Tarascon, J.-M.; Sainton, P. Method and System for Charging a Battery Wherein the Internal Pressure Varies Depending on State of Charge and Temperature. Eur. Pat. Appl. 04292653, 9 November 2004. 129. Bothe, M.; Schröder, G.B.R.; Breuch, G. Battery Charger with State of Charge Determination on the Primary Side. Eur. Pat. Appl. 05012135, 6 June 2005. 130. Nicolai, J. Quick Charge Method for Battery and Integrated Circuit for Performing the Method. Eur. Pat. Appl. 94400575, 16 March 1994. 131. Yuen, T.K. Battery Charger. Eur. Pat. Appl. 94300655, 28 January 1994. 132. Lang, O. Method for Regulating Charging of Nickel Cadmium and Nickel Metal Hydride Batteries, and Power Supply Unit. Eur. Pat. Appl. 06762920, 26 July 2006. 133. Umicore. Battery Recycling in the EU. Presented in the NaatBatt Battery Recycling Workshop, Ann Arbor, MI, USA. 30 November 2016. Available online: http://naatbatt.org/wp-content/uploads/2016/12/What% E2%80%99s-the-Rest-of-the-World-Doing_Caffarey_A.pdf (accessed on 24 July 2017). 134. About the Colabats Project. Available online: http://www.colabats.eu/about-the-colabats-project (accessed on 27 July 2017). 135. Cheret, D.; Santén, S. Battery Recycling. Eur. Pat. Appl. 05075736, 30 March 2005. 136. Luidold, S.; Antrekowitsch, H. Recovery of Rare Earth Metals from Waste Material by Leaching in Non-Oxidizing Acid and by Precipitation Using Sulphates. Eur. Pat. Appl. 10188264, 20 October 2010. 137. Pudas, J.; Erkkila, A.; Viljamaa, J. Battery Recycling Method. Eur. Pat. Appl. 11708474, 16 March 2011. 138. Hanulik, J. Battery Recycling Process, in Particular for Dry Batteries. Eur. Pat. Appl. 95920722, 16 June 1995. 139. Wiaux, J.; Lazouni, A.; Indaco, A. Used Battery and Cell Sorting Method and Apparatus. Eur. Pat. Appl. 94906358, 24 February 1994. Batteries 2017, 3, 25 16 of 16

140. Alavi, K.; Salami, B. Method of Treating Nickel-Cadmium of Nickel-Hydride Cells. Eur. Pat. Appl. 93113054, 14 August 1993. 141. Traverse, J.-P.; Bressolles, J.-C.; Archier, P. Method for Processing Scrap Containing One or More Alloys that React to Form Hydrides, to Enable Recycling Thereof. Eur. Pat. Appl. 96926454, 24 July 1996. 142. Toro, L.; Veglio, F.; Beolchini, F.; Pagnanelli, F.; Furlani, G.; Granata, G.; Moscardini, E. Plant and Process for the Treatment of Exhausted Accumulators and Batteries. Eur. Pat. Appl. 11185532, 18 October 2011. 143. Laucournet, R.; Billy, E. Method for Recovering Metals Contained in an Ni-MH Battery. International Application No. PCT/IB2014/066008, 21 May 2015. 144. Black, V. Soap Dispenser Conversion Kit. Eur. Pat. Appl. 15156912, 27 February 2015. 145. Young, K. Metal Hydride. In Reference Module in Chemistry, Molecular Science and Chemical Engineering; Reedijk, J., Ed.; Elsevier: Waltham, MA, USA, 2013. [CrossRef]

© 2017 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).