关键词: 锂离子电池, 正极材料, 固溶体, 层状结构, 低热固相法

Abstract: The cathode material of Li[Li0.167Mn0.583Ni0.25]O2 was synthesized by low-heat solid state reaction.The results of XRD and FESEM indicated that the powders of the material were well crystallized with the uniform diameters ranging from 60 nm to 100 nm and could be indexed as α-NaFeO2 structure(R3-m space).Galvanostatic charge-discharge tests showed that the electrode delivered the capacity of about 120 mAh/g with good cyclability when cycled in 2.5~4.4V at 0.5C.When the cut-off potential was set up to 4.6V,the cathode delivered much larger capacities with the maximum of 234 mAh/g.It was observed that the discharge capacity gradually increased with the increment of the cycle number.The transformation between Mn(Ⅳ) and Mn(Ⅲ) could be responsible for the increasing capacity.However,the causes for this transformation in different potenticals varied.

Key words: lithium batteries, cathode materials, solid solution, layered structure, low-heat solid state reaction