Synthesis of Ni–rich LiNi0.83Co0.12Mn0.05O2 cathode materials with low residual Lithium content without washing

Abstract

Residual lithium compounds are harmful to the use and performance of nickel cobalt manganese ternary cathode materials, especially when the Ni content is >60%. Therefore, the residual lithium should be controlled at a reasonable level. Water washing is an effective method to remove these residual lithium compounds, but the material reacts with water during the washing process and thus its recycling performance deteriorates. In this paper, LiNi0.83Co0.12Mn0.05O2 Ni–rich cathode materials with low residual lithium content without washing were investigated. The results show that the specific discharge capacity of the unwashed samples in the first few cycles of 1C is slightly lower than that of the washed samples with the same total residual lithium content, but their cycle performance is much better. Besides, Li/Ni disorder of unwashed samples is lower than that of the washed samples. More important, after fully charged, the exothermic reaction of the unwashed sample is much slighter, which helps to improve the thermal stability of the lithium–ion batteries.