Patent ID: 10741838

Abstract:
Provided is cathode active material powder or a cathode that is capable of improving the cycle characteristics of nonaqueous electrolyte rechargeable batteries at high voltage and exhibiting excellent capacity retention. The powder has a composition of: Lix−wNawCo1−yMyO2+z (0.950≤x≤1.100, 0<y≤0.050, −0.1≤z≤0.1, 0≤w≤0.020; M: rare earth elements, Ti, Zr, Mo, Mn, Ni, Cu, Al, Ga, etc), and a core-shell structure composed of a lithium-containing composite oxide region as core and a Li-ion-conductive oxide region as shell. The core contains Li, Co, and oxygen, and has Co concentration of not higher than 90% as calculated by formula: ((Co concentration on shell external surface)/(Co concentration at shell boundary of core/shell structure))×100. The shell is an amorphous layer containing La, Ti, Co, and oxygen, covering the core at least partly.