Method for producing lithium composition and method for producing sulfide solid electrolyte material

Patent metadata

Field	Value
Publication number	US-9923233-B2
Application number	US-201615172739-A
Country	US
Kind code	B2
Filing date	Jun 3, 2016
Priority date	Jun 12, 2015
Publication date	Mar 20, 2018
Grant date	Mar 20, 2018

Abstract

A method for producing a lithium composition capable of suppressing the generation of polysulfides is provided. The method for producing a lithium composition includes a first aqueous solution forming step of forming a first aqueous solution by reacting iodine with a reducing aqueous solution containing calcium oxide, formic acid, and water under a condition of a pH of 5.5 or more and a pH of 10.21 or less through heating, a second aqueous solution forming step of forming a second aqueous solution by adding calcium oxide to the first aqueous solution, a third aqueous solution forming step of forming a third aqueous solution by adding lithium carbonate to the second aqueous solution, and a Li 2 S forming step of forming the lithium sulfide (Li 2 S) by sulfurizing lithium hydroxide (LiOH) to form lithium hydrosulfide (LiHS) and then eliminating hydrogen sulfide from lithium hydrosulfide (LiHS).

First claim

What is claimed is:

1. A method for producing a lithium composition, the lithium composition comprising at least lithium sulfide (Li 2 S) and lithium iodide (LiI); the method comprising:
forming a first aqueous solution containing calcium iodide (CaI 2 ) by reacting iodine with a reducing aqueous solution containing calcium oxide, formic acid, and water under a condition of a pH of 5.5 or more and a pH of 10.21 or less through heating;
forming a second aqueous solution containing calcium hydroxide (Ca(OH) 2 ) and the calcium iodide (CaI 2 ) by adding calcium oxide to the first aqueous solution;
forming a third aqueous solution containing lithium hydroxide (LiOH) and lithium iodide (LiI) by adding lithium carbonate to the second aqueous solution; and
forming Li 2 S by sulfurizing the lithium hydroxide (LiOH) to form lithium hydrosulfide (LiHS) and then eliminating hydrogen sulfide from the lithium hydrosulfide (LiHS).

2. The method for producing a lithium composition according to claim 1 , wherein an iodine-containing aqueous solution, which contains the iodine and water, is heated and then the reducing aqueous solution is added to the heated iodine-containing aqueous solution during forming of the first aqueous solution.

3. The method for producing a lithium composition according to claim 1 wherein the iodine and the reducing aqueous solution are respectively added to heated water during forming the first aqueous solution.

4. The method for producing a lithium composition according to claim 3 wherein the iodine is added to the heated water a plurality of times.

5. The method for producing a lithium composition according to claim 1 , further comprising:
adding LiX (X represents F, Cl, or Br) to the third aqueous solution between forming the third aqueous solution and forming the Li 2 S.

6. A method for producing a sulfide solid electrolyte material, the method comprising:
preparing a lithium composition by the method for producing a lithium composition according to claim 1 ; and
synthesizing a sulfide solid electrolyte material by reacting the lithium composition with a sulfide other than Li 2 S.

Assignees

• Toyota Motor Co Ltd

Inventors

• Hashimoto Yuichi
• Yanagi Takuo
• Doi Takayoshi

Classifications

• C01B17/22

  Alkali metal sulfides or polysulfides · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M2300/0068

  inorganic · CPC title

• H01M2300/002

  Inorganic electrolyte · CPC title

• H01M10/0562 Primary

  Solid materials · CPC title