高镍LiNi0.9Co0.05Mn0.05O2正极材料的形貌调控及电化学性能研究

Study on Morphology Regulation and Electrochemical Performance of High-nickel LiNi0.9Co0.05Mn0.05O2 Cathode Material

研究氢氧化物共沉淀反应的氨浓度对Ni0.9Co0.05Mn0.05(OH)2前驱体及正极材料的影响。结果表明,高氨浓度下制备的前驱体H-NCM具有更大的一次晶粒和二次颗粒粒径,且一次晶粒有序定向生长形成高暴露{010}晶面。其正极材料H-LNCM的{010}活性晶面增大、锂镍混排降低以及锂离子扩散系数提高,从而产生优异的电化学性能。在2.7~4.3 V电压区间,0.1 C倍率下放电比容量为218.31 mAh·g^-1,5 C倍率下的放电容量为152.24 mAh·g^-1,1 C倍率下循环100次的容量保持率为76.05%,均优于L-LNCM材料。

The effects of ammonia concentration in the hydroxide co-precipitation on Ni0.9Co0.05Mn0.05(OH)2 precursor and cathode material were studied.The results showed that the precursor H-NCM prepared at high ammonia concentration had larger primary and secondary grain sizes,and the primary grains were grown in an orderly direction to form highly exposed{010}crystal planes.The{010}active crystal plane of its H-LNCM cathode material was increased,the Li/Ni 2+mixing was reduced,and the lithium ion diffusion coefficient was increased,resulting in excellent electrochemical performance.Under the voltage range of 2.7~4.3 V,the discharge capacity was 218.31 mAh·g^-1 at 0.1 C rate,152.24 mAh·g^-1 at 5 C rate,and the capacity retention rate after 100 cycles at 1 C rate was 76.05%,which was better than that of L-LNCM material.