Sulfide-based lithium-ion-conducting solid electrolyte glass, all-solid lithium secondary battery, and method for manufacturing all-solid lithium secondary battery
A sulfide-based lithium-ion-conducting solid electrolyte glass is formed from sulfide-based lithium-ion-conducting solid electrolyte, and α-alumina.
1. A solid electrolyte glass comprising:
a sulfide-based lithium-ion-conducting solid electrolyte,
wherein the sulfide-based lithium-ion-conducting solid electrolyte contains α-alumina, and a lithium containing compound selected from the group consisting of Li 2 S—SiS 2 , Li 2 S—SiS 2 —LiI, Li 2 S—SiS 2 —LiBr, Li 2 S—SiS 2 —LiCl, Li 2 S—SiS 2 —B 2 S 3 —LiI, Li 2 S—SiS 2 —P 2 S 5 —LiI, Li 2 S—B 2 S 3 , Li 2 S—P 2 S 5 , Li 2 S—P 2 S 5 —LiI, Li 2 S—P 2 S 5 -ZmSn, and Li 2 S—GeS 2 wherein,
Z=Ge, Zn, Ga,
m is integer except 0, and
n is integer except 0,
α-alumina is mixed in the sulfide-based lithium-ion-conducting solid electrolyte in a range of from 5 to 7 wt % based on the weight of the sulfide-based lithium-ion-conducting solid electrolyte, and
the chemical constituents in the lithium containing compound are chemically bonded together.
2. A method for manufacturing an all-solid lithium secondary battery comprising the sulfide-based lithium-ion-conducting solid electrolyte glass of claim 1 , the method comprising steps of:
heating and melting a mixture containing the α-alumina and the lithium containing compound selected from the group consisting of selected from the group consisting of Li 2 S—SiS 2 , Li 2 S—SiS 2 —LiI, Li 2 S—SiS 2 —LiBr, Li 2 S—SiS 2 —LiCl, Li 2 S—SiS 2 —B 2 S 3 —LiI, Li 2 S—SiS 2 —P 2 S 5 —LiI, Li 2 S—B 2 S 3 , Li 2 S—P 2 S 5 , Li 2 S—P 2 S 5 —LiI, Li 2 S—P 2 S 5 -ZmSn, and Li 2 S—GeS 2 wherein,
Z=Ge, Zn, Ga,
m is integer except 0, and
n is integer except 0, and
rapidly cooling the mixture that is heated and melted.
3. The method for manufacturing an all-solid lithium secondary battery according to claim 2 , further comprising steps of:
preparing at least one electrode layer that is one of a positive electrode layer and a negative electrode layer; and
heating and compressing electrolyte powder formed from the sulfide-based lithium-ion-conducting solid electrolyte glass with the electrode layer, thereby forming an all-solid lithium secondary battery element having the electrode layer and the electrolyte layer integrated in one piece.
4. The method for manufacturing an all-solid lithium secondary battery according to claim 3 , wherein the heating is conduced under a temperature condition in the range of a glass softening temperature of the sulfide-based lithium-ion-conducting solid electrolyte glass, and the heating is conducted in a time range in which crystallization of the sulfide-based lithium-ion-conducting solid electrolyte glass does not progress.
5. The method for manufacturing an all-solid lithium secondary battery according to claim 4 , wherein the range of the glass softening temperature is between 200° C. and 300° C., and the time range in which the crystallization does not progress is within five hours.
6. The method for manufacturing an all-solid lithium secondary battery according to claim 3 , further comprising a step of sealing at least a portion of the all-solid lithium secondary battery element with a low melting point glass whose softening temperature is 350° C. or below.
7. The method for manufacturing an all-solid lithium secondary battery according to claim 6 , wherein the low melting point glass is glass made of four compositions, the four compositions being V 2 O 5 , ZnO, BaO and TeO 2 .
8. The method for manufacturing an all-solid lithium secondary battery according to claim 6 , wherein all of the steps are continuously processed in a dry inert gas atmosphere.
9. The solid electrolyte glass according to claim 1 , wherein the lithium containing compound is Li 2 S—SiS 2 —LiBr or Li 2 S—SiS 2 —LiCl.
10. The solid electrolyte glass according to claim 1 , wherein the lithium containing compound is Li 2 S—SiS 2 , Li 2 S—SiS 2 —B 2 S 3 —LiI, Li 2 S—SiS 2 —P 2 S 5 —LiI, Li 2 S—B 2 S 3 , Li 2 S—P 2 S 5 , Li 2 S—P 2 S 5 —LiI, Li 2 S—P 2 S 5 -ZmSn, or Li 2 S—GeS 2 wherein,
Z=Ge, Zn, Ga,
m is integer except 0, and
n is integer except 0.
11. The solid electrolyte glass according to claim 1 , wherein the lithium containing compound is Li 2 S—B 2 S 3 .
12. An all-solid lithium secondary battery comprising:
a sulfide-based lithium-ion-conducting solid electrolyte as a solid electrolyte glass, the sulfide-based lithium-ion-conducting solid electrolyte containing α-alumina and a lithium containing compound selected from the group consisting of Li 2 S—SiS 2 , Li 2 S—SiS 2 —LiI, Li 2 S—SiS 2 —LiBr, Li 2 S—SiS 2 —LiCl, Li 2 S—SiS 2 —B 2 S 3 —LiI, Li 2 S—SiS 2 —P 2 S 5 —LiI, Li 2 S—B 2 S 3 , Li 2 S—P 2 S 5 , Li 2 S—P 2 S 5 —LiI, Li 2 S—P 2 S 5 -ZmSn, and Li 2 S—GeS 2 wherein,
Z=Ge, Zn, Ga,
m is integer except 0, and
n is integer except 0,
α-alumina is mixed in the sulfide-based lithium-ion-conducting solid electrolyte in a range of from 5 to 7 wt % based on the weight of the sulfide-based lithium-ion-conducting solid electrolyte, and
the chemical constituents in the lithium containing compound are chemically bonded together.
13. The all-solid lithium secondary battery according to claim 12 , further comprising an all-solid lithium secondary battery element having the solid electrolyte glass in a layer interposed between a pair of electrodes formed from a positive electrode layer and a negative electrode layer.
14. The all-solid lithium secondary battery according to claim 13 , wherein the all-solid lithium secondary battery element is formed by molding one of the positive electrode layer and the negative electrode layer in one piece with the solid electrolyte glass in a layer.
15. The all-solid lithium secondary battery according to claim 12 , wherein the lithium containing compound is Li 2 S—SiS 2 —LiBr or Li 2 S—SiS 2 —LiCl.
16. The all-solid lithium secondary battery according to claim 12 , wherein the lithium containing compound is Li 2 S—SiS 2 , Li 2 S—SiS 2 —B 2 S 3 —LiI, Li 2 S—SiS 2 —P 2 S 5 —LiI, Li 2 S—B 2 S 3 , Li 2 S—P 2 S 5 , Li 2 S—P 2 S 5 —LiI, Li 2 S—P 2 S 5 -ZmSn, or Li 2 S—GeS 2 wherein,
Z=Ge, Zn, Ga,
m is integer except 0, and
n is integer except 0.
17. The all-solid lithium secondary battery according to claim 12 , wherein the lithium containing compound is Li 2 S—B 2 S 3 .
18. A solid electrolyte glass comprising:
a sulfide-based lithium-ion-conducting solid electrolyte,
wherein the sulfide-based lithium-ion-conducting solid electrolyte consists essentially of α-alumina and a lithium containing compound selected from the group consisting of Li 2 S—SiS 2 , Li 2 S—SiS 2 —LiI, Li 2 S—SiS 2 —LiBr, Li 2 S—Sis 2 —LiCl, Li 2 S—SiS 2 —B 2 S 3 —LiI, Li 2 S—SiS 2 —P 2 S 5 —LiI, Li 2 S—B 2 S 3 , Li 2 S—P 2 S 5 —LiI, Li 2 S—P 2 S 5 -ZmSn, and Li 2 S—GeS 2 wherein,
Z=Ge, Zn, Ga,
m is integer except 0, and
n is integer except 0, and
the solid electrolyte glass is formed by heating and melting a mixture that consists essentially of the α-alumina and the lithium containing compound, and cooling the mixture that is heated and melted.