Sulfide-based solid electrolyte used for lithium ion secondary battery and production method for same, solid electrolyte layer, and lithium ion secondary battery

Patent metadata

Field	Value
Publication number	US-2023198013-A1
Application number	US-202318150925-A
Country	US
Kind code	A1
Filing date	Jan 6, 2023
Priority date	Jul 7, 2020
Publication date	Jun 22, 2023
Grant date	—

Abstract

A sulfide solid electrolyte to be used in a lithium-ion secondary battery, including an argyrodite crystal, in which the crystal is represented by a composition formula Lia—M—Zb—Hac; M is at least one element selected from Na, K, and elements each of which exists as any of divalent to pentavalent cations in the crystal; Z is at least one element selected from elements that exists as a divalent anion in the crystal; Z includes S; Ha is at least one element selected from the group consisting of F, Cl, Br, and I; a, b, and c in the composition formula indicate a ratio among contents (unit: at%) of the respective elements and satisfy 5 < a < 7, 4 < b < 6, and 0 < c < 2; and a maximum distance between Li ions in the crystal is 2.54 Å or shorter.

First claim

1 . A sulfide solid electrolyte to be used in a lithium-ion secondary battery, comprising
an argyrodite crystal, wherein the crystal is represented by a composition formula Li a —M—Z b —Ha c ; M is at least one element selected from Na, K, and elements each of which exists as any of divalent to pentavalent cations in the crystal; Z is at least one element selected from elements that exists as a divalent anion in the crystal; Z comprises S; Ha is at least one element selected from the group consisting of F, Cl, Br, and I; a, b, and c in the composition formula indicate a ratio among contents (unit: at%) of the respective elements and satisfy 5 < a < 7, 4 < b < 6, and 0 < c < 2; and a maximum distance between Li ions in the crystal is 2.54 Å or shorter.

2 . The sulfide solid electrolyte according to claim 1 , wherein Z further comprises O.

3 . The sulfide solid electrolyte according to claim 2 ,
wherein the crystal comprises M n+ ; M n+ is any of monovalent to trivalent cations; M of M n+ is at least one element M1 selected from Al, Ca, Mg, Na, and K; and M n+ exists at a site of Li.

4 . The sulfide solid electrolyte according to claim 3 , wherein in the crystal, a distance between M n+ and O is 2.3 Å or shorter.

5 . The sulfide solid electrolyte according to claim 2 ,
wherein M comprises P mainly; M further comprises an element M2 that is at least one of Si and B; and the element M2 exists at a site of P.

6 . The sulfide solid electrolyte according to claim 2 , wherein the crystal comprises an oxide anion having a Q0 structure having an M-O bond that is a bond of M and O, and
M constituting the M-O bond comprises at least one element M3 selected from Si, Al, Zr, and B.

7 . A manufacturing method of a sulfide solid electrolyte to be used in a lithium-ion secondary battery, comprising:
mixing raw materials containing Li, M, Z, and Ha, followed by heat treatment, and obtaining an argyrodite crystal in a cooling process; and causing a temperature to stay in a range of 500° C. to 400° C. for 1 minute or longer in the cooling process, wherein M is at least one element selected from Na, K, and elements each of which exists as any of divalent to pentavalent cations in the crystal; Z is at least one element selected from elements that exists as a divalent anion in the crystal; and Ha is at least one element selected from the group consisting of F, Cl, Br, and I.

8 . A manufacturing method of a sulfide solid electrolyte to be used in a lithium-ion secondary battery, comprising:
mixing raw materials containing Li, M, Z, and Ha, followed by heat treatment, and obtaining an argyrodite crystal in a cooling process; and reheating the obtained argyrodite crystal and causing a temperature to stay in a range of 500° C. to 400° C. for 1 minute or longer, wherein M is at least one element selected from Na, K, and elements each of which exists as any of divalent to pentavalent cations in the crystal; Z is at least one element selected from elements that exists as a divalent anion in the crystal; and Ha is at least one element selected from the group consisting of F, Cl, Br, and I.

9 . A manufacturing method of a sulfide solid electrolyte to be used in a lithium-ion secondary battery, comprising:
mixing raw materials containing Li, M, Z, and Ha, followed by heat treatment, and obtaining an argyrodite crystal in a cooling process, wherein in the cooling process, a cooling rate from 500° C. to 400° C. is 500° C./s or higher; M is at least one element selected from Na, K, and elements each of which exists as any of divalent to pentavalent cations in the crystal; Z is at least one element selected from elements that exists as a divalent anion in the crystal; and Ha is at least one element selected from the group consisting of F, Cl, Br, and I.

10 . The manufacturing method of a sulfide solid electrolyte according to claim 7 , wherein the heat treatment is performed in an atmosphere containing a sulfur element.

11 . The manufacturing method of a sulfide solid electrolyte according to claim 7 , wherein a temperature of the heat treatment is 500° C. or higher.

12 . A solid electrolyte layer comprising the sulfide solid electrolyte according to claim 1 .

13 . A lithium-ion secondary battery comprising the sulfide solid electrolyte according to claim 1 .

Assignees

• Agc Inc

Inventors

• AKATSUKA Kosho
• Fujii Naoki
• SHOBUDANI Tetsushi
• Nishizawa Manabu
• Tanaka Hiroaki
• Terazono Shinji
• Hayashi Hideaki

Classifications

• H01M10/0525

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

• H01M10/0562 Primary

  Solid materials · CPC title

• H01M2300/0068

  inorganic · CPC title

• C01B25/14

  Sulfur, selenium, or tellurium compounds of phosphorus · CPC title

• Y02E60/10

  Energy storage using batteries · CPC title