| 摘要 |
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. |
| 主权项 |
1. Cathode active material powder for a nonaqueous electrolyte rechargeable battery, said cathode active material powder having a composition represented by formula (I):
Lix−wNawCo1−yMyO2+z (I)wherein x, y, z, and w satisfy 0.950≦x≦1.100, 0<y≦0.050, −0.1≦z≦0.1, 0≦w≦0.020, respectively; M is one or more elements selected from the group consisting of K, Mg, Ca, Y, rare earth elements, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Fe, Ni, Cu, Ag, Zn, B, Al, Ga, C, Si, Sn, N, P, S, F, and Cl,and a core-shell structure consisting of a lithium-containing composite oxide region as a core and a Li-ion-conductive oxide region as a shell,
wherein said core comprises Li, Co, and oxygen, and has a Co concentration of not higher than 90% as calculated by formula (II):
((Co concentration on shell external surface)/(Co concentration at shell boundary of core/shell structure))×100 (II) and wherein said shell is an amorphous layer comprising La, Ti, Co, and oxygen, covering said core at least partly. |
