Positive electrode material and battery
View Patent ↗A positive electrode material includes a positive electrode active material, a first solid electrolyte, and a coating material covering at least part of the surface of the positive electrode active material. The first solid electrolyte is represented by the following compositional formula (1): Li a M b X c . . . Formula (1). In the compositional formula (1), a, b and c are each independently a positive real number, M includes calcium, yttrium, and at least one rare earth element other than yttrium, and X includes at least one selected from the group consisting of F, Cl, Br and I.
1 . A positive electrode material comprising:
a positive electrode active material;
a first solid electrolyte; and
a coating material covering at least part of the surface of the positive electrode active material, wherein
the first solid electrolyte is represented by the following compositional formula (1):
Li a M b X c Formula (1)
wherein
in the compositional formula (1),
a, b and c are each independently a positive real number,
M comprises calcium, yttrium, and at least one rare earth element selected from the group consisting of Ce, Pr, Nd, Pm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu, and
X comprises at least one selected from the group consisting of F, Cl, Br and I.
2 . The positive electrode material according to claim 1 , wherein
the coating material includes O.
3 . The positive electrode material according to claim 1 , wherein
the coating material includes Li.
4 . The positive electrode material according to claim 1 , wherein
the coating material comprises at least one selected from the group consisting of lithium phosphate and lithium niobate.
5 . The positive electrode material according to claim 1 , wherein
the mass ratio of the coating material to the positive electrode active material is greater than or equal to 0.5 mass % and less than or equal to 2.0 mass %.
6 . The positive electrode material according to claim 1 , wherein
the thickness of the coating material is greater than or equal to 2 nm and less than or equal to 20 nm.
7 . The positive electrode material according to claim 1 , wherein
X comprises at least one selected from the group consisting of F, Cl and Br.
8 . The positive electrode material according to claim 1 , wherein
X comprises at least two selected from the group consisting of F, Cl and Br.
9 . The positive electrode material according to claim 1 , wherein
X comprises Cl and Br.
10 . The positive electrode material according to claim 1 , wherein
the positive electrode active material comprises a lithium-containing transition metal oxide.
11 . A battery comprising:
a positive electrode comprising the positive electrode material according to claim 1 ;
a negative electrode; and
an electrolyte layer disposed between the positive electrode and the negative electrode.
12 . The battery according to claim 11 , wherein
the electrolyte layer comprises a sulfide solid electrolyte.
13 . The positive electrode material according to claim 1 , wherein
X comprises F.
14 . The positive electrode material according to claim 1 , wherein
X comprises F and at least one selected from the group consisting of Cl, Br and I.
15 . The positive electrode material according to claim 1 ,
wherein the first solid electrolyte is represented by Composition formula (2) below,
Li 6-2a-3d Ca a (Y 1-b Gd b ) d Br 6-c Cl c Formula (2)
where
Composition formula (2) above satisfies
0<a,
0<b<1,
0<c<6, and
0<d<1.5.
16 . The positive electrode material according to claim 15 ,
wherein Composition formula (2) above satisfies 0.01≤a≤0.3.
17 . The positive electrode material according to claim 16 ,
wherein Composition formula (2) above satisfies a≤0.2.
18 . The positive electrode material according to claim 15 ,
wherein Composition formula (2) above satisfies 0.1≤b≤0.9.
19 . The positive electrode material according to claim 15 ,
wherein Composition formula (2) above satisfies 0.8≤b<1.
20 . The positive electrode material according to claim 15 ,
wherein Composition formula (2) above satisfies 1.0≤c≤1.2.