SOLID a- LITHIUM ELECTROLYTE

• US 20180226171A1
• Filed: 07/15/2016
• Published: 08/09/2018
• Est. Priority Date: 07/31/2015
• Status: Active Grant

• Current Assignee: Tokyo Institute of Technology (National University Corporation Tokyo Institute of Technology), Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Tokyo Institute of Technology (National University Corporation Tokyo Institute of Technology), Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: KANNO, Ryoji, HORI, Satoshi
• Granted Patent: US 10,741,299 B2
• Time in Patent Office: Days
• CPC Class Codes: C01B 25/14 Sulfur, selenium, or tellurium compounds of phosphorus
• CPC Class Codes: H01B 1/06 mainly consisting of other non-metallic substances
• CPC Class Codes: H01B 1/10 sulfides
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/0562 Solid materials
• CPC Class Codes: H01M 2300/0068 inorganic
• CPC Class Codes: H01M 4/62 Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

(Problem to be Solved) The present invention was made in view of the above-described problems, with an object of providing a Li—P—S-based sulfide solid electrolyte material with both excellent electrochemical stability and a high lithium ion conductivity, providing a method of producing the Li—P—S-based sulfide solid electrolyte material, and providing a lithium battery including the sulfide solid electrolyte material.

(Solution) There is provided a sulfide solid electrolyte material including a Li element, a P element, and a S element and having peaks at positions of 2θ=17.90±0.20, 29.0±0.50, and 29.75±0.25′ in powder X-ray diffraction measurement using a Cu-Kαray having an X-ray wavelength of 1.5418 Å, in which assuming that the diffraction intensity of the peak at 2θ=17.90±0.20 is I_A and the diffraction intensity of the peak at 2θ=18.50±0.20 is I_B, a value of I_B/I_A is less than 0.50.

Claims

1. A sulfide solid electrolyte material comprising a Li element, a P element, and a S element and having peaks at positions of 2θ

=17.90±

0.20, 29.0±

0.50, and 29.75±

0.25°

in powder X-ray diffraction measurement using a Cu-Kα

ray having an X-ray wavelength of 1.5418 Å

, wherein assuming that a diffraction intensity of the peak at 2θ

=17.90±

0.20 is I_A and a diffraction intensity of the peak at 2θ

=18.50±

0.20 is I_B, a value of I_B/I_A is less than 0.50.

2. The sulfide solid electrolyte material according to claim 1, wherein the sulfide solid electrolyte material comprises a composition of Li_3+x+5yP₁₋

yS₄ (0<

x≤

0.6, 0<

y<

0.2).

3. The sulfide solid electrolyte material according to claim 1, wherein the sulfide solid electrolyte material comprises a composition of Li_3+5yP₁₋

yS₄ (0<

y≤

0.2).

4. The sulfide solid electrolyte material according to claim 1, wherein the sulfide solid electrolyte material comprises a composition of Li_3+xPS₄ (0<

x≤

0.6).

5. The sulfide solid electrolyte material according to claim 1, wherein the sulfide solid electrolyte material comprises a composition of Li_3+xPS₄ (0.1≤

x≤

0.2).

6. The sulfide solid electrolyte material according to claim 1 wherein the sulfide solid electrolyte material comprises a crystal structure which comprises a plurality of PS₄ tetrahedra arranged so that orientations of apexes of the PS₄ tetrahedra are staggered, and in which the PS₄ tetrahedra do not share an edge with each other, and a ratio between a maximum axial length and a minimum axial length among lattice constants determined in diffraction measurement is 1.1 or less.

7. A battery comprising a cathode active material layer comprising a cathode active material, an anode active material layer comprising an anode active material, and an electrolyte layer formed between the cathode active material layer and the anode active material layer, wherein at least one of the cathode active material layer, the anode active material layer, and the electrolyte layer comprises the sulfide solid electrolyte material according to claim 1.

8. A method of producing the sulfide solid electrolyte according to claim 1 the method comprising:

a step of fragmenting a raw material composition comprising a component of the sulfide solid electrolyte;

an ion conductive material synthesis step of synthesizing an amorphized ion conductive material by mechanical-mixing the fragmented raw material composition; and

a heating step of heating the amorphized ion conductive material to thereby obtain the sulfide solid electrolyte material.