铌复合钇共掺杂改善高镍单晶三元正极材料的高温电化学性能研究

High Temperature Electrochemical Performance of Monocrystalline High⁃Nickel Ternary Cathode Material Improved by Co⁃Doping of Yttrium and Niobium Elements

为解决高镍单晶三元正极材料表面残碱高、高温循环性能差等问题,利用铌与钇等元素共同掺杂对正极材料进行改性,提高其电化学性能。以高镍单晶三元前驱体Ni_(0.6)Co_(0.1)Mn_(0.3)(OH)_(2)为原料,采用高温固相反应合成不同双元素掺杂系列正极材料。结果表明,Nb与Y双掺杂样品具有优异的高温循环稳定性和倍率性能,45℃下循环50圈后,铌与钇双掺杂样品的容量保持率较单掺铌样品高2.58个百分点;2C倍率充放电条件下,铌与钇双掺杂样品放电容量比单掺铌的样品高6.2 mAh/g。

Aiming at the shortcomings of single crystalline high-nickel ternary cathode material,including high residual alkali on the surface,poor cycle performance at high temperature,co-doping with niobium and yttrium was proposed to modify the cathode material for improving its electrochemical performance.With monocrystalline high-nickel ternary precursor(Ni_(0.6)Co_(0.1)Mn_(0.3)(OH)_(2))as raw material,a series of cathode materials co-doped with two different elements were synthesized by high-temperature solid-state reaction.The results show that the niobium and yttrium co-doped sample presents excellent cycling stability and rate capability at high temperature.Compared to niobium-doped sample,it can have capacity retention rate higher by 2.58 percentage points after 50 cycles at 45℃,and discharge capacity higher by 6.2 mAh/g at 2C charge⁃discharge rate.