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US 20140O84224A1 (19) United States (12) Patent Application Publication (10) Pub. No.: US 2014/0084224 A1 Rittmeyer et al. (43) Pub. Date: Mar. 27, 2014

(54) PROCESS FOR PREPARING (30) Foreign Application Priority Data SULFIDE May 27, 2011 (DE) ...... 10 2011 O76 572.7 (75) Inventors: Peter Rittmeyer, Sulzbach/Taunus (DE): Publication Classification Ulrich Wietelmann, Friedrichsdorf (DE); Uwe Lischka, Frankfurt am Main (51) Int. Cl.

Bernhard Figer, Frankfurt am Main 52) U.S. C. (DE), Armin Stoll, Hemsbach (DE): (52) CPC ...... COIB 17/22 (2013.01) Dirk Dawidowski, Friedberg (DE) USPC ...... 252/519.4; 423/566.2:423/511 (73) Assignee: CHEMETALL GMBH, Frankfurt am (57) ABSTRACT Main (DE) The invention relates to a novel process for preparing and to the use thereof, wherein a reaction of lithium (21) Appl. No.: 14/119,980 containing strong bases with Sulfide is undertaken in an aprotic organic within the temperature range (22) PCT Filed: May 29, 2012 from -20 to 120° C. under inert conditions. The lithium Sulfide obtained by the process is used as a positive material (86). PCT No.: PCT/EP2012/06OO14 in a galvanic element or for the synthesis of Li -conductive S371 (c)(1), Solids, especially for the synthesis of glasses, glass ceramics (2), (4) Date: Nov. 25, 2013 or crystalline products. US 2014/0084224 A1 Mar. 27, 2014

PROCESS FOR PREPARING LITHIUM alkylene, lithium arylene, and lithium amides, and react SULFIDE according to the following equations: 0001. The invention relates to a novel method for prepar ing lithium sulfide, and use thereof. 0002 Lithium sulfide is currently of interest as a raw mate rial for the synthesis of Li ion-conductive Solids (glass, glass 0013. In the X-ray diffraction diagram, the isolated mate ceramics, or crystalline products such as Li argyrodite) or as rial displays only lines for the desired LiS, and by-products cathode material in lithium-sulfur batteries. Lithium-sulfur such as LiSH are not detectable. batteries have a much higher energy than lithium-ion batteries, and are therefore of great interest for potential use in 0014. The strong Li-containing bases which are used are the area of electromobility. preferably commercially available materials or solutions of 0003. The following methods for preparing lithium sulfide butyllithium or hexyllithium in , or organo are described in Gmelin's Handbook of Inorganic Chemistry, lithium amides, preferably or Lithium, Supplementary Volume (1969): lithium hexamethyldisilazide in various aprotic . 0004 Compounding of lithium metal and sulfur, 0015 Typical aprotic solvents are aliphatic and aromatic 0005 Reaction of ammonium sulfide or sulfur with hydrocarbons, preferably or , as well as etheric lithium metal in liquid ; Solvents selected from the group of aliphatic or cyclic ethers, 0006 Reaction of lithium ethoxide with HS in . preferably , THF, or mixtures of these solvents. 0007. In all these methods, product mixtures containing 0016. The advantages of the method according to the more or less polysulfide result which must sometimes be invention over the prior art are as follows: laboriously purified. Thus, it is known to reduce lithium sul 0017 Use of commercially available starting materials; fate with carbon or hydrogen at temperatures of approxi 0.018 Avoidance of operations using air- and moisture mately 500° C. The document EP 0802 159 A1 describes the sensitive solids such as Li metal or LiFI; reaction of with in the gaseous phase in a temperature range of 130° to 445°C. In 0.019 Carrying out the reaction at moderate tempera addition, the document U.S. Pat. No. 4,126,666 A1 describes tures, so that additional energy for heating or cooling is a reaction of with hydrogen sulfide in the not required; gaseous phase in a temperature range of 500 to 700° C. 0020 Isolation of the product using simple methods 0008 Furthermore, the reaction of lithium metal or Such as filtration and drying: lithium with hydrogen sulfide in etheric solvents such 0021. Obtaining a product in a pure phase, thus avoid as (THF) is known from the documents U.S. ing further purification steps such as heating to destroy Pat. No. 3,615,191 A1 and U.S. Pat. No. 3,642,436A1. A LiSH. mixture composed of lithium sulfide (LiS) and lithium 0022. The lithium sulfide obtained according to the inven hydrogen sulfide (LiSH) is formed in these reactions. The tion is used as a positive electrode composition in a galvanic undesirable LiSH may be converted to LiS and hydrogen element, for the synthesis of Li ion-conductive solids, in sulfide by thermal treatment at 180°-200° C. particular for the synthesis of glass, glass ceramics, or crys 0009 Lastly, the reaction of lithium hydroxide or lithium talline products, and particularly preferably for the synthesis carbonate with hydrogen sulfide in N-methylpyrrolidone as of Li argyrodite. Solvent at 130° C. is known from the document EP 1460 039 A1, initially resulting in LiSH and then formation of LiS at EXAMPLE 1. 200° C. The document EP 1681 263 A1 proposes purification of LiS, which has been obtained by the reaction of lithium Preparation of Lithium Sulfide from Hydrogen hydroxide with hydrogen Sulfide in an aprotic organic Sol Sulfide vent, by washing with an organic solvent at temperatures above 100° C. (0023 1000 g (1449 mL, 3.47 mol, 1.0 eq) n-butyllithium 0010. The object of the invention is to provide a simple (2.4M in hexane) was placed in an inerted 3-L flat-flange method by means of which lithium sulfide may be prepared in double-shell reactor having a temperature sensor, gas inlet high purity under the most economical, simple reaction con tube (immersion tube), and gas discharge line (above a gas ditions possible. meter and gas scrubber) under an argon atmosphere, and an 0011. The object is achieved according to the invention by additional 380 mL hexane was then added. The reaction solu a method in which lithium-containing strong bases are tion was cooled to 10°C. with stirring. A total of 59 g (38.7 L. reacted with hydrogen Sulfide in an aprotic organic solvent in 1.73 mol, 0.5eq.) hydrogen sulfide was then introduced into a temperature range of -20° to 120° C., preferably in a tem the reaction solution through an immersion tube at 10-15°C. perature range of 0° to 80°C., under inert conditions. Within over a period of 3 h, resulting in precipitation of a colorless the meaning of the invention, “under inert conditions” is Solid. To keep the reaction Suspension stirrable, an additional understood to mean operation under protective gas to exclude total quantity of 550 mL hexane was added. After completion air and atmospheric moisture. of the gas introduction, the reactor contents were heated to 0012 To this end, gaseous hydrogen sulfide is introduced room temperature (22°C.) and stirred for an additional 2 h. into a solution of an Li-containing strong in an aprotic The reaction suspension was then filtered through a G3 frit, Solvent. The reaction proceeds spontaneously at room tem and the remaining colorless Solid was thoroughly washed perature, and is exothermic. The lithium sulfide precipitates with several portions of hexane. The solid obtained was dried as a white Solid, and after the reaction is complete may be to a constant weight under high vacuum at room temperature, isolated by filtration and drying. The lithium-containing then analyzed by X-ray diffractrometry (XRD). Lithium sul strong bases are selected from the group comprising lithium fide in a pure phase was obtained. US 2014/0084224 A1 Mar. 27, 2014

1.-10. (canceled) 11. A method for preparing lithium Sulfide comprising: reacting a lithium-containing strong base with hydrogen Sulfide in an aprotic organic solvent at a temperature of from -20° to 120° C. under inert conditions. 12. A method according to claim 11, wherein the lithium containing strong base is selected from the group consisting of a lithium alkylene, a lithium arylene, and a . 13. A method according to claim 11, wherein the lithium containing strong base is selected from the group consisting of butyllithium, hexyllithium, lithium diisopropylamide and lithium hexamethyldisilazide. 14. A method according to claim 11, wherein the aprotic organic solvent comprises at least one member selected from the group consisting of an aliphatic , an aromatic hydrocarbon and an etheric solvent. 15. A method according to claim 11, wherein the aprotic organic solvent comprises at least one member selected from the group consisting of hexane, toluene, diethyl ether, and tetrahydrofuran 16. A method according to claim 11, wherein the reaction is carried out at a temperature range of 0° to 80°C. 17. A positive electrode comprising the lithium sulfide prepared by the process of claim 11 and a galvanic element. 18. A Li ion-conductive solids comprising the lithium Sul fide prepared by the method of claim 11. 19. A glass, glass ceramics, or crystalline product compris ing the lithium sulfide prepared by the method of claim 11. 20. Liargyrodite prepared with the lithium sulfide prepared by the method of claim 11. k k k k k