Abstract:

A series of LiNi_0.8Co_0.10-y Mn_0.05+y Al_0.05O₂ (y=0.01,0.02,0.03,0.04) materials with different cobalt-manganese ratios were prepared by co-precipitation method with oxalic acid as precipitant and transition metal manganese as cobalt replacement element, and the effect of gradual substitution of manganese for cobalt on the properties of Ni-rich quaternary materials was studied. The experimental results show that the LiNi_0.8Co_0.08Mn_0.07Al_0.05O₂ material had the best morphology, structural development and electrochemical performance. The co-doping of cobalt and manganese has a synergistic effect on the synthesized LiNi_0.8Co_0.10-y Mn_0.05+y Al_0.05O₂ material, and the electrochemical capacity can be improved when the ratio of manganese doping is lower than that of cobalt. When the doping ratio of manganese exceeds that of cobalt, the capacity begins to decrease, indicating that the excessive doping ratio of manganese is not helpful for the improvement of the electrochemical performance of the synthesized high-nickel quaternary materials.

Key words: electrochemistry, Li-ion battery, high-nickel quaternary materials, synthesis, nanomaterials

摘要：

采用共沉淀法，以草酸为沉淀剂，过渡金属锰作为钴的替代元素，制备了系列不同钴锰比例的镍钴锰铝锂（LiNi_0.8Co_0.10-y Mn_0.05+y Al_0.05O₂，y=0.01，0.02，0.03，0.04）四元材料，研究锰对钴的逐步取代对镍钴锰铝锂四元材料的性能产生的影响。实验结果表明，当y=0.02时的LiNi_0.8Co_0.08Mn_0.07Al_0.05O₂材料具有最好的形貌、结构发育程度以及电化学性能。钴锰共掺杂对合成的LiNi_0.8Co_0.10-y Mn_0.05+y Al_0.05O₂材料产生了协同作用，且锰掺杂比例低于钴时可以提升材料电化学容量，当锰掺杂比例超过钴时容量开始下降，说明掺杂比例过多的锰对合成的高镍四元材料的电化学性能提升没有助益。

关键词: 电化学, 锂离子电池, 高镍四元材料, 合成, 纳米材料