Patent ID: 11888154
Assignee: CONTEMPORARY AMPEREX TECHNOLOGY CO., LIMITED
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  Y | IPC H

Claim 1:
2. A positive electrode sheet, comprising a positive electrode current collector and a positive electrode film layer provided on at least one surface of the positive electrode current collector; at least one of the positive electrode film layers is of a multi-layer structure, and any positive electrode film layer having a multi-layer structure respectively comprises a first positive electrode active material having a core-shell structure and a second positive electrode active material in different layers;
the first positive electrode active material comprises an inner core, a first coating layer covering the inner core and a second coating layer covering the first coating layer; wherein the inner core comprises Li1+xMn1-yAyP1-zRzO4, the first coating layer comprises pyrophosphate MP2O7 and phosphate XPO4, and the second coating layer comprises carbon element;
wherein,
A is selected from one or more elements of Zn, Al, Na, K, Mg, Mo, W, Ti, V, Zr, Fe, Ni, Co, Ga, Sn, Sb, Nb and Ge;
R is selected from one or more elements of B, Si, N and S;
x is selected from −0.100-0.100;
y is selected from 0.001-0.500;
z is selected from 0.001-0.100;
M and X are independently selected from one or more elements of Li, Fe, Ni, Mg, Co, Cu, Zn, Ti, Ag, Zr, Nb and Al;
the second positive electrode active material is selected from one or more of LiNiaCobMn(1-a-b)O2, LiNiaCobAl(1-a-b)O2 and LiCoO2; wherein a is independently selected from any value in the range of 0.3-0.9, and the sum of a and b is independently selected from any value in the range of 0.3-0.9; and
optionally, any of the positive electrode film layers having a multi-layer structure respectively comprises the first positive electrode active material and the second positive electrode active material in adjacent layers.