Lithium cobalt oxide positive electrode material, secondary battery and device

The invention relates to a lithium cobalt oxide positive electrode material as well as a secondary battery and a device comprising the positive electrode lithium supplementing material. The positive electrode lithium supplementing material comprises magnesium and yttrium doped lithium cobalt oxide, the magnesium and yttrium doped lithium cobalt oxide comprises a lithium ion layer and a cobalt ion layer, the magnesium element is doped in the lithium ion layer, and the yttrium element is doped in the cobalt ion layer. The lithium cobalt oxide positive electrode material disclosed by the invention is stable in structure under high voltage, can realize reversible charging and discharging under the high voltage of 4.6 V, and has excellent cycle performance and high energy density. 本申请涉及一种钴酸锂正极材料以及包括该正极补锂材料的二次电池和装置。本申请的正极补锂材料包括镁钇掺杂的钴酸锂，其中，所述镁钇掺杂的钴酸锂包括锂离子层和钴离子层，所述镁元素掺杂于所述锂离子层中，所述钇元素掺杂于所述钴离子层中。本申请的钴酸锂正极材料在高电压下结构稳定，可以实现在4.6V高电压的可逆充放电，具有优异的循环性能和高的能量密度。