Battery

1. A battery, comprising:

a cathode;

an anode; and

an electrolyte layer disposed between the cathode and the anode,

wherein:

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

the first electrolyte layer is disposed between the cathode and the second electrolyte layer,

the first electrolyte layer includes a first solid electrolyte material,

the second electrolyte layer includes a second solid electrolyte material which is a material different from the first solid electrolyte material,

the first solid electrolyte material is represented by a composition formula Li α M β X γ,

where 2.5≤α≤3,

1≤β≤1.1,

γ=6,

M is at least one kind selected from the group consisting of Y, Mg, Ca, Sr, Ba, Zn, Sc, Al, Ga, Bi, Zr, Hf, Ti, Sn, Ta, and Nb, and

X is at least one kind selected from the group consisting of Cl and Br, and the second solid electrolyte material is represented by a composition formula Li α′ M′ β′ X′ γ′,

where 2.7≤α′≤3,

1≤(β′≤1.1,

γ′=6,

M′ includes at least one kind selected from the group consisting of Y, Mg, Ca, Sr, Ba, Zn, Sc, Al, Ga, Bi, Zr, Hf, Ti, Sn, Ta, and Nb, and

X′ includes I and at least one kind selected from the group consisting of Cl and Br.

2. The battery according to claim 1 , wherein

M includes yttrium.

3. The battery according to claim 1 , wherein

M′ includes yttrium.

4. The battery according to claim 1 , wherein

the cathode includes a cathode active material, and

the cathode active material is lithium nickel-cobalt-manganese oxide.

5. The battery according to claim 1 , wherein

the cathode includes a mixture of a cathode active material and the first solid electrolyte material.

6. The battery according to claim 5 , wherein

the cathode active material is lithium nickel-cobalt-manganese oxide.