Co掺杂富镍正极材料LiNi_(0.9)Mn_(0.1)O_(2)的制备及其性能

Preparation and performance of Co-doped Ni-rich cathode material LiNi_(0.9)Mn_(0.1)O_(2)

采用共沉淀法、结合两段式煅烧工艺制备富镍正极材料LiNi_(0.9)Mn_(0.1)O_(2),并探究最佳终烧温度以及最优Co掺杂量。结果表明:最佳终烧温度为740℃,最优Co掺杂量为10%(摩尔分数);此时制备的正极材料LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)不仅保持了原有层状结构,而且层状结构更加有序、Li^(+)/Ni^(2+)混排程度最低;采用该正极材料装配的电池电化学性能最优异,在0.1C电流密度下,首次放电比容量为250.92 mA·h/g,100次循环后容量保持率为91.82%;在5C大倍率电流密度下,放电比容量可达200.55 mA·h/g。Co掺杂可稳定富镍正极材料的层状结构,抑制Li^(+)/Ni^(2+)混排,提高富镍正极材料的综合电化学性能。

By coprecipitation method and two-stage calcination process,the Ni-rich cathode material LiNi_(0.9)Mn_(0.1)O_(2) was prepared and the optimal final calcination temperature and the optimal Co doping content were investigated.The results show that the optimal calcination temperature is 740℃and the optimal Co doping content is 10%(mole fraction).The prepared cathode material LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) possesses the intrinsic layered structure.Its layered structure is more orderly and its mixing degree of Li^(+)/Ni^(2+)is the lowest.The electrochemical performances are also the best with the first discharge specific capacity of 250.92 mA·h/g at 0.1C current density,the capacity retention rate of 91.82%after 100 cycles and the specific capacity of 200.55 mA·h/g at 5C.Co doping can stabilize the layered structure,reduce the mixing degree of Li^(+)/Ni^(2+)and improve the electrochemical performances of Ni-rich cathode material.