Solid electrolyte, method for producing the same, and secondary battery comprising solid electrolyte

Patent metadata

Field	Value
Publication number	US-9722276-B2
Application number	US-98996809-A
Country	US
Kind code	B2
Filing date	May 12, 2009
Priority date	May 13, 2008
Publication date	Aug 1, 2017
Grant date	Aug 1, 2017

Abstract

A solid electrolyte comprising:
LiBH 4 ; and an alkali metal compound represented by the following formula (1):

MX  (1)
(in the formula (1), M represents an alkali metal atom, and X represents one selected from the group consisting of halogen atoms, NR 2 groups (each R represents a hydrogen atom or an alkyl group) and N 2 R groups (R represents a hydrogen atom or an alkyl group)).

First claim

The invention claimed is:

1. A solid electrolyte for a lithium ion secondary battery, consisting of:
LiBH 4 ;
LiX 1 , where X 1 represents a halogen atom; and
optionally, an alkali metal compound represented by the formula (1a):
MX 2   (1a)

in formula (1a), M represents at least one alkali metal atom selected from the group consisting of Na, K, Rb, and Cs, and X 2 represents a halogen atom.

2. The solid electrolyte according to claim 1 , wherein
a molar ratio between the LiBH 4 and the LiX 1 is as follows: LiBH 4 :LiX 1 =1:1 to 20:1.

3. A lithium ion secondary battery comprising the solid electrolyte according to claim 1 .

4. A method for producing the solid electrolyte for a lithium ion secondary battery according to claim 1 , comprising:
melt-mixing LiBH 4 with LiX 1 , where X 1 represents a halogen atom, and optionally with an alkali metal compound represented by the formula (1a):
MX 2   (1a)

in formula (1a), M represents at least one alkali metal atom selected from the group consisting of Na, K, Rb, and Cs, and X 2 represents a halogen atom; and then
cooling the mixture.

5. The method for producing a solid electrolyte according to claim 4 , wherein
a molar ratio between the LiBH 4 and the LiX 1 mixed with each other is as follows: LiBH 4 :LiX 1 =1:1 to 20:1.

6. A method for producing a solid electrolyte for a lithium ion secondary battery, comprising:
heating a solid electrolyte obtained by the production method according to claim 4 at or above 115° C; and then
cooling the solid electrolyte.

7. The solid electrolyte according to claim 1 , wherein the solid electrolyte consists of the LiBH 4 , the LiX 1 , and the alkali metal compound represented by the formula (1a).

8. A lithium ion secondary battery comprising the solid electrolyte according to claim 7 .

9. A method for producing the solid electrolyte for a lithium ion secondary battery according to claim 1 , comprising:
mixing LiBH 4 with LiX 1 (wherein X 1 represents a halogen atom) and an alkali metal compound represented by the formula (1a):
MX 2   (1a)

in formula (1a), M represents at least one alkali metal atom selected from the group consisting of Na, K, Rb, and Cs, and X 2 represents a halogen atom;
heating the mixture, thereby melting or sintering the mixture; and then
cooling the mixture.

10. A method for producing a solid electrolyte for a lithium ion secondary battery, comprising:
heating a solid electrolyte obtained by the production method according to claim 9 at or above 115° C; and then
cooling the solid electrolyte.

11. A solid electrolyte for a lithium ion secondary battery, consisting of:
LiBH 4 ;
a first alkali metal compound represented by the formula (1b):
MX 1   (1b)

in formula (1b), M represents Li and X 1 represents at least one selected from the group consisting of NR 2 groups (each R represents a hydrogen atom or an alkyl group) and N 2 R groups (R represents a hydrogen atom or an alkyl group); and
optionally a second alkali metal compound represented by the formula (1a):
MX 2   (1a)

in formula (1a), M represents at least one alkali metal atom selected from the group consisting of Na, K, Rb, and Cs, and X 2 represents a halogen atom.

12. A lithium ion secondary battery comprising the solid electrolyte according to claim 11 .

13. A method for producing the solid electrolyte for a lithium ion secondary battery according to claim 11 , comprising:
mixing LiBH 4 with a first alkali metal compound represented by the formula (1b):
MX 1   (1b)

in formula (1b), M represents Li and X 1 represents at least one selected from the group consisting of NR 2 groups (each R represents a hydrogen atom or an alkyl group) and N 2 R groups (R represents a hydrogen atom or an alkyl group);
heating the mixture, thereby melting or sintering the mixture; and then
cooling the mixture.

14. A method for producing a solid electrolyte for a lithium ion secondary battery, comprising:
heating a solid electrolyte obtained by the production method according to claim 13 at or above 115° C.; and then
cooling the solid electrolyte.

15. The solid electrolyte according to claim 11 , wherein the solid electrolyte consists of the LiBH 4 , the first alkali metal compound represented by the formula (1b) and the second alkali metal compound represented by the formula (1a).

16. A lithium ion secondary battery comprising the solid electrolyte according to claim 15 .

17. A method for producing a solid electrolyte according to claim 13 , wherein:
when the LiBH 4 and the first alkali metal compound represented by the formula (1b) are mixed with each other, a second alkali metal compound represented by the formula (1a):
MX 2   (1a)

in formula (1a), M represents at least one alkali metal atom selected from the group consisting of Na, K, Rb, and Cs, and X 2 represents a halogen atom,
is further mixed.

18. A method for producing a solid electrolyte for a lithium ion secondary battery, comprising:
heating a solid electrolyte obtained by the production method according to claim 17 at or above 115° C; and then
cooling the solid electrolyte.

Assignees

• Maekawa Hideki
• Takamura Hitoshi
• Orimo Shinichi
• Matsuo Motoaki
• Nakamori Yuko
• Ando Mariko
• Noda Yasuto
• Karahashi Taiki
• Univ Tohoku

Inventors

• Maekawa Hideki
• Takamura Hitoshi
• Orimo Shinichi
• Matsuo Motoaki
• Nakamori Yuko
• Ando Mariko
• Noda Yasuto
• Karahashi Taiki

Classifications

• H01M2300/0068

  inorganic · CPC title

• H01M10/052 Primary

  Li-accumulators · CPC title

• H01M2300/0091

  in the form of mixtures · CPC title

• H01M10/0562 Primary

  Solid materials · CPC title

• H01B1/122

  Ionic conductors · CPC title