The battery includes a positive electrode, a first electrolyte layer, a second electrolyte layer, and a negative electrode arranged in this order. The first electrolyte layer contains a first solid electrolyte material and a second solid electrolyte material. In the first electrolyte layer, the mass ratio of the second solid electrolyte material to the first solid electrolyte material is greater than 0.05 and less than 1. The second electrolyte layer contains the second solid electrolyte material. The first solid electrolyte material is formed of Li, M, O, and X. In the first solid electrolyte material, M is at least one element selected from the group consisting of metal elements other than Li, and metalloids, and X is at least one element selected from the group consisting of Cl, Br, and I. The second solid electrolyte material has a composition different from that of the first solid electrolyte material.
1. A battery comprising:
a positive electrode, a first electrolyte layer, a second electrolyte layer, and a negative electrode arranged in this order,
wherein:
the first electrolyte layer contains a first solid electrolyte material and a second solid electrolyte material,
in the first electrolyte layer, a mass ratio of the second solid electrolyte material to the first solid electrolyte material is greater than 0.05 and less than 1,
the second electrolyte layer contains the second solid electrolyte material,
the first solid electrolyte material is formed of Li, M, O, and X,
in the first solid electrolyte material, M is at least one element selected from the group consisting of metal elements other than Li, and metalloids, and X is at least one element selected from the group consisting of Cl, Br, and I, and
the second solid electrolyte material has a composition different from that of the first solid electrolyte material.
2. The battery according to claim 1 , wherein:
the second solid electrolyte material has a reduction potential lower than a reduction potential of the first solid electrolyte material.
3. The battery according to claim 1 , wherein:
the mass ratio is greater than 0.05 and less than or equal to 0.50.
4. The battery according to claim 3 , wherein:
the mass ratio is greater than or equal to 0.10 and less than or equal to 0.50.
5. The battery according to claim 4 , wherein:
M contains at least one element selected from the group consisting of Nb and Ta.
6. The battery according to claim 1 , wherein:
the first solid electrolyte material is represented by chemical formula (1) below:
Li α MO β X γ (1)
where
M is at least one element selected from the group consisting of metal elements other than Li, and metalloids,
X is at least one element selected from the group consisting of Cl, Br, and I, and
following mathematical formulae are satisfied:
1.0≤α≤1.2,
1.0≤β≤1.3, and
3.6≤γ≤4.0.
7. The battery according to claim 6 , wherein:
M is at least one element selected from the group consisting of Nb and Ta, and
mathematical formula: γ=5+α−2β is satisfied.
8. The battery according to claim 1 , wherein:
the second solid electrolyte material is formed of Li, M′ and X′,
where
M′ is at least one element selected from the group consisting of metal elements other than Li, and metalloids, and
X′ is at least one element selected from the group consisting of Cl, Br, and I.
9. The battery according to claim 8 , wherein:
M′ contains yttrium.
10. The battery according to claim 9 , wherein:
the second solid electrolyte material is represented by chemical formula (2) below:
Li 6-3z Y z X′ 6 (2)
where
X′ is at least one element selected from the group consisting of Cl, Br, and I, and
mathematical formula: 0<z<2 is satisfied.
11. The battery according to claim 10 , wherein:
the second solid electrolyte material is Li 3 YCl 6 .
12. The battery according to claim 1 , wherein:
the second solid electrolyte material is a sulfide solid electrolyte.
13. The battery according to claim 12 , wherein:
the sulfide solid electrolyte contains lithium sulfide and phosphorus sulfide.
14. The battery according to claim 12 , wherein:
the sulfide solid electrolyte is Li 2 S—P 2 S 5 .
15. The battery according to claim 1 , wherein:
the positive electrode contains the first solid electrolyte material.