With an increase in Ni content,the capacity of high-nickel layered metal oxides(LiNixMn,Co1-x-yO2(0.8≤x＜1,NCM)greatly decreases.In view of such problem,it is proposed that singly-crystal NCM cathode material be modified by dual SiO2@Li2SiO3 coating to improve its electrochemical performance.During the synthesis process,the reaction of SiO2+2LiOH=Li2SiO3+H2O can consume the residue lithium on the material surface,thus improving diffusion kinetics of interface lithium ions and inhibiting side reaction at the interface.It is shown that the modified cathode material delivers a specific discharge capacity of 156.88 mAh/g after 120 cycles,with capacity retention rate of 70.52％.
关键词
锂离子电池/三元正极材料/改性/高镍层状金属氧化物/表面包覆/高能量密度/循环稳定性
Key words
lithium-ion battery/ternary cathode material/modification/high nickel layered metal oxide/surface coating/high energy density/cyclic stability
万方数据