Crystalline solid electrolyte and production method therefor

Patent metadata

Field	Value
Publication number	US-2016164136-A1
Application number	US-201414902021-A
Country	US
Kind code	A1
Filing date	Feb 28, 2014
Priority date	Jul 4, 2013
Publication date	Jun 9, 2016
Grant date	—

Abstract

Provided is a novel crystalline solid electrolyte which can be used as a dispersion medium when slurrying polar solvents such as NMP, acetone, and DMF, and for which a decrease in conductivity when the crystalline solid electrolyte is immersed in said solvents can be suppressed. Proposed is a crystalline solid electrolyte represented by Compositional Formula: Li x Si y P z S a Ha w (here, Ha includes one or two or more of Br, Cl, I, and F, and 2.4<(x−y)/(y+z)<3.3), in which the content of S is 55 to 73% by mass, the content of Si is 2 to 11% by mass, and the content of a Ha element is 0.02% by mass or more.

First claim

1 . A crystalline solid electrolyte being represented by Compositional Formula: Li x Si y P z S a Ha w (here, Ha includes one or two or more of Br, Cl, I, and F, and 2.4<(x−y)/(y+z)<3.3), wherein the content of S is 55 to 73% by mass, the content of Si is 2 to 11% by mass, and the content of a Ha element is 0.02% by mass or more.

2 . The crystalline solid electrolyte according to claim 1 , the crystalline solid electrolyte having peaks exhibited at positions of 2θ=20.2°±0.5°, 24.0°±0.5°, and 29.7°±0.5° and peaks exhibited at positions of 2θ=24.8°±0.5° to 26.1°±0.5°, for a XRD pattern obtained by X-ray diffraction measurement using a CuKα line.

3 . The crystalline solid electrolyte according to claim 2 , wherein the peaks exhibited at the positions of 2θ=20.2°±0.5°, 24.0°±0.5°, and 29.7°±0.5° in claim 2 are derived from a Li—Si—P—S type crystal structure, and the Li—Si—P—S type crystal structure is a crystal structure, in which the crystal is a cubic crystal of a=b for a position coordinate in a crystal lattice, a PS 4 or SiS 4 tetrahedral center exists at the position of a=0, b=0, and c=0.5, the position of a=0, b=0.5, and c=0.69, and the position satisfying the following symmetry, and for the symmetry, the c-axis passing through a=0 and b=0.5 has the four-fold helical symmetry that is subjected to a translation by c=0.5, thereby being the plane 004 to be the glide plane of 110 direction, being the plane 220 to be the glide plane of 001 direction, and being the plane 200 to be the mirror plane.

4 . A lithium secondary battery having the constitution constituted by using the crystalline solid electrolyte according to claim 1 .

5 . A method for producing a crystalline solid electrolyte, the method comprising mixing raw materials including lithium sulfide, phosphorus sulfide, silicon sulfide, and a halogen compound, and burning the mixture thus obtained at 500 to 650° C. under the atmosphere of sulfide gas.

6 . The method for producing a crystalline solid electrolyte according to claim 5 , wherein the halogen is one or two or more of Br, Cl, I, and F.

7 . A lithium secondary battery having the constitution constituted by using the crystalline solid electrolyte according to claim 2 .

8 . A lithium secondary battery having the constitution constituted by using the crystalline solid electrolyte according to claim 3 .

Assignees

• Mitsui Mining & Smelting Co

Inventors

• Higuchi Tsutomu
• Miyashita Norihiko
• Matsuzaki Kenji
• Ito Takahiro
• Tomonari Kenji

Classifications

• H01M2220/20

  Batteries in motive systems, e.g. vehicle, ship, plane · CPC title

• H01M2300/008

  Halides · CPC title

• H01M10/0562 Primary

  Solid materials · CPC title

• H01B1/10

  sulfides · CPC title

• H01M2220/30

  Batteries in portable systems, e.g. mobile phone, laptop · CPC title