The LiCoO2 is a commercially successful lithium-ion battery cathode material;however,its actual capacity falls short of its theoretical capacity(274 mAh/g).Increasing the charging cutoff voltage can boost discharge capacity;however,the instability of LiCoO2 under high voltage compromises its cycle life.This study aims to introduce an in situ co-doping strategy with Al-Y-Zr to enhance the cycling performance of LiCoO2 at 4.53 V.The LiCo(1-a-b-c-d)AlaZrbYcMgdO2 cathode material was synthesized using a high-temperature solid-phase method by mixing Al-Y-Zr-doped Co3O4,Li2CO3,and MgO in a specific stoichiometric ratio.The impact of in situ co-doping on high-voltage LiCoO2's cycling performance was investigated.X-ray diffraction revealed a hexagonal layered crystal structure before and after doping,whereas scanning electron microscopy confirmed the regulation of crystal particle size by the doping elements.Electrochemical impedance spectroscopy demonstrated that the co-doping of Al-Y and Al-Y-Zr effectively inhibits growth of Rct value during cycle testing.Test results from coin and pouch cells showed that in situ co-doping substantially improves the cycling performance,with the latter displaying substantial pronounced enhancement.This study contributes to advancing the application of high-voltage lithium cobalt oxide cathodes.In addition,it provides an experimental foundation for research and development in high-specific-energy lithium-ion battery technology.
关键词
锂离子电池/钴酸锂/高电压/共掺杂/循环性能
Key words
Li ion batteries/LiCoO2/high voltage/co-doping/cyclic performance
万方数据