Solid electrolyte material and cell using same

1 . A solid electrolyte material comprising Li, Ti, Al, and F, wherein

the solid electrolyte material is represented by a composition formula: Li 6-(4-x)b (Ti 1-x Al x ) b F 6 , where 0.1≤x≤0.9 and 0.8≤b≤1.2 are satisfied, and

a ratio of the amount of Li to the sum of the amounts of Ti and Al is 1.7 or more and 4.2 or less.

2 . The solid electrolyte material according to claim 1 , wherein

0.3≤x≤0.8 and 0.9≤b≤1.1 are satisfied.

3 . The solid electrolyte material according to claim 1 , wherein

0.6≤x<0.8 and 0.9≤b≤1.1 are satisfied.

4 . The solid electrolyte material according to claim 1 , wherein

the solid electrolyte material is amorphous.

5 . A battery comprising:

a positive electrode;

a negative electrode; and

an electrolyte layer disposed between the positive electrode and the negative electrode, wherein

at least one selected from the group consisting of the positive electrode, the negative electrode, and the electrolyte layer contains the solid electrolyte material according to claim 1 .

6 . The battery according to claim 5 , wherein

the electrolyte layer includes a first electrolyte layer and a second electrolyte layer,

the first electrolyte layer is disposed between the positive electrode and the negative electrode,

the second electrolyte layer is disposed between the first electrolyte layer and the negative electrode, and

the first electrolyte layer contains the solid electrolyte material.

7 . The battery according to claim 6 , wherein

the second electrolyte layer further comprises a halide solid electrolyte different from the solid electrolyte material.