US 2016.0036042A1 (19) United States (12) Patent Application Publication (10) Pub. No.: US 2016/0036042 A1 FORBERT et al. (43) Pub. Date: Feb. 4, 2016 (54) LITHIUM TRANSITION METAL PHOSPHATE Publication Classification SECONDARY AGGLOMERATES AND PROCESS FOR ITS MANUFACTURE (51) Int. Cl. HOLM 4/36 (2006.01) (71) Applicant: JOHNSON MATTHEY PUBLIC HOLM 4/58 (2006.01) LIMITED COMPANY, London (GB) HOLM 4/1397 (2006.01) COB 25/215 (2006.01) (72) Inventors: Rainald FORBERT, Moosburg (DE); (52) U.S. Cl. Gerhard NUSPL, Munchen (DE): CPC ............... H0IM 4/136 (2013.01); COIB 25/45 Nicolas TRAN, Nandlstadt (DE); (2013.01); H0IM 4/5825 (2013.01); H0IM Guoxian LIANG, Saint-Hyacinthe, 4/1397 (2013.01); COIP 2004/50 (2013.01); Quebec (CA) COIP 2006/12 (2013.01); COIP 2006/40 (21) Appl. No.: 14/777,120 (2013.01); HOIM 2004/028 (2013.01) (22) PCT Filed: Mar. 14, 2014 (57) ABSTRACT (86). PCT No.: PCT/EP2014/055.187 A Lithium-transition-metal-phosphate compound of formula S371 (c)(1), Lios, Fe,MPO) in the form of secondary particles made (2) Date: Sep.15, 2015 of agglomerates of spherical primary particles wherein the primary particles have a size in the range of 0.02-2pm and the (30) Foreign Application Priority Data secondary particles a mean size in the range of 10-40 pm and a BET surface of 16-40 m/g, a process for its manufacture Mar. 15, 2013 (EP) .................................. 13159637.1 and the use thereof. Patent Application Publication Feb. 4, 2016 Sheet 1 of 9 US 2016/0036042 A1 8 Patent Application Publication Feb. 4, 2016 Sheet 2 of 9 US 2016/0036042 A1 Fig 388 Patent Application Publication Feb. 4, 2016 Sheet 3 of 9 US 2016/0036042 A1 Patent Application Publication Feb. 4, 2016 Sheet 4 of 9 US 2016/0036042 A1 & 4 Patent Application Publication Feb. 4, 2016 Sheet 5 of 9 US 2016/0036042 A1 Figire 5 & Patent Application Publication Feb. 4, 2016 Sheet 6 of 9 US 2016/0036042 A1 is: 86 Patent Application Publication Feb. 4, 2016 Sheet 7 of 9 US 2016/0036042 A1 8: 8. 88. 38 88: 88 capacity &isfg Patent Application Publication Feb. 4, 2016 Sheet 8 of 9 US 2016/0036042 A1 figre 8 a 20 to so ea too 20 as so taxity itik US 2016/0036042 A1 Feb. 4, 2016 LITHIUM TRANSTION METAL PHOSPHATE 10007 Ravet et al. (Proceedings of 196' ECS meeting SECONDARY AGGLOMERATES AND 1999, 99-102) showed that carbon coated LiFePO with 1 PROCESS FOR ITS MANUFACTURE wt.-% carbon content can deliver a discharge capacity of 160 0001. The present invention relates to a lithium transition mAh/g at 80° C. at a discharge rate of C/10 using a polymer metal phosphate compound of formula Lios Fel-M, (PO4) electrolyte. in the form of secondary particles made of spherical primary 0008 Various approaches for preparing carbon compos particles, a process for its manufacture and its use as active ites and carbon coated LiMPO materials have been pub material in electrodes for secondary lithium-ion-batteries. lished so far. 0002 Rechargeable lithium ion batteries have been 0009. As discussed in the foregoing, the morphology of widely used in the past and in the presence as power sources the particles of LiMPO compounds is one of the essential key in a wide range of applications such as mobile phones, laptop factors for obtaining high charge and discharge capacities and computers, digital cameras, electrical vehicles and home the full theoretical capacity. However, synthesis of these com appliances. In rechargeable lithium ion batteries, cathode pounds especially via wet chemistry methods or hydrother materials are one of the key components and mainly devoted mal methods yields materials with large primary particles to the performance of the batteries. Since the pioneering work causing a negative impact such as a relatively low capacity of of Goodenough et al. (Padhi, Goodenough et al., J. Electro the related lithium cells. chem. Soc. 1997, 144, 1188) LiMPO compounds with 0010. The main disadvantages of powders comprising M=Fe, Mn, Ni and Co with an ordered olivine-type structure Smaller particles are a very small bulk and tap density and a have attracted an extensive attention due to their high theo different processing compared to compounds with larger par retical specific capacity of around 170 mAhg'. ticle sizes. 0003 LiMPO compounds adopt an olivine related struc 0011 EP 2 413 402 A1 discloses a process for the prepa ture which consists of hexagonal closed packing of oxygen ration of lithium iron phosphate wherein a mixture of hydro atoms with Li" and M" cations located in half of the octahe thermally prepared LiFePO and polyethylene glycol is wet dral sides and P' cations in /s of tetrahedral sides. This milled, the milled product dried and spray milled. structure may be described as chains along the c direction of (0012 US 2010/0233540A1 describes secondary agglom edge sharing MO octahedra that are cross-linked by the PO erates of primary particles of a lithium iron phosphate with an groups forming a three-dimensional network. Tunnels per olivine type structure with an average particle diameter of the pendicular to the 010 and 001 directions contain octahe secondary agglomerates of 5 to 100 um and with a porosity of drally coordinated Li' cations along the b-axis which are 50-40% consisting of primary particles of 50-550 nm repre mobile in these cavities. Among these phosphates, LiFePO is sented by the formula Li FeM(PO)X. The primary the most attractive, because of its high stability, low cost and particles are synthesized under Super critical hydrothermal high compatibility with environments. conditions. The secondary agglomerates according to US 0004. However, it is difficult to attain the full capacity 2010/0233540 A1 are obtained by a spray drying and have a because electronic conductivities are very low, which leads to spherical form and the BET-surface of these secondary initial capacity loss and poor rate capability and diffusion of agglomerates is 5-15 m/g. Li" ion across the LiFePO/FePO boundary is slow due its 0013 The disadvantages of the process as described in US intrinsic character. The pure electrical performance of 2010/0233540 A1 is the energy consumption during the dry LiFePO cathode material has also attracted interest among ing of the slurries which have a solid content of only 5-20%. many researches. The duration of the pyrolysis of the secondary agglomerates 0005. It was found that for LiFePO and related com pounds Small particle size and well shaped crystals are impor after spray drying is 10 hours and longer which also generates tant for enhancing the electrochemical properties. In particles increased energy costs. with a small diameter the Li-ions may diffuse over smaller 0014. It was therefore an object of the present invention to distances between the Surfaces and center during Li-interca provide lithium transition metal phosphates in particle form lation and de-intercalation and LiMPO on the particle sur comprising primary and secondary particles, whereas the sec face contributes mostly to the charge/discharge reaction. ondary particles are consisting of agglomerated primary par 0006) Substitution of Li" or Fe" with cations is a further ticles with or without carbon coating and which provide a way to attain full capacity as described for example by high bulk and tap density, therefore providing increased elec Yamada et al. J. Electrochem. Soc. 2001, 148, A960, A1153, trode density and hence the energy density of the battery A747 which reported the preparation of Mn-doped LiMn. when the lithium transition metal phosphate according to the 6 FeoPO. Further, doped Li Zno FeoPO was also pro present invention is used as the active electrode material. posed. Also doping with cobalt, titanium, Vanadium and 0015 This object is achieved by a lithium-transition molybdenum, chromium and magnesium is known. Herle et metal-phosphate of formula Lios, Fe, M.(PO) in the form al. in Nature Materials, Vol. 3, pp. 147-151 (2004) describe of secondary particles made of agglomerates of spherical lithium-iron and lithium-nickel phosphates doped with zirco primary particles wherein the primary particles have a size in nium. Morgan et al. describes in Electrochem. Solid State the range of 0.02-2 um, more preferably in the range of Lett. 7 (2), A30-A32 (2004) the intrinsic lithium-ion conduc 0.02-0.95 um or in other embodiments 0.7-0.95 um and the tivity in Li, MPO (M=Mn, Fe, Co, Ni) olivines. Yamada et al. secondary particles have a mean size (do) in the range of 5-40 in Chem. Mater. 18, pp. 804-813, 2004 deal with the electro um and a BET surface of 16-40 m/g. X is a number 0.3 and chemical, magnetic and structural features of Li,(MnFe) 0sy<1. PO, which are also disclosed e.g. in WO2009/009758. Struc 0016 Surprisingly it was found that the lithium-transition tural variations of Li,(MnFe)PO, i.e. of the lithiophilite metal-phosphates according to the invention when used as triphylite series, were described by Losey et al. The Canadian active material in electrodes for secondary lithium ion batter Mineralogist, Vol. 42, pp. 1105-1115 (2004). ies display a high electrical conductivity and an improved US 2016/0036042 A1 Feb. 4, 2016 electric capacity as well as improved rate characteristics com 0028. In one further embodiment, the lithium transition pared to batteries with electrodes having an active material of metal phosphates according to the invention have an excellent the prior art. tap porosity in the range of 55-65%.