Improved electrochemical performance of high-nickel cathode material with electronic conductor RuO_2 as the protecting layer for lithium-ion batteries

摘要

High nickel cathode materials have more superiority in the application of new lithium-ion batteries owing to higher specific capacity and energy density. Nevertheless, the rate and cycle performance are deteriorated as the surface particles are highly prone to the phase transition. In order to solve this problem, RuO2 coated LiNi0.81Co0.1Mn0.09O2 (LNCM) cathode material was prepared through the uniform precipitation of RuCl3 in the alkaline environment. The rate and cycle performances of LNCM were obviously improved by RuO2 coating. Especially for 3 wt% RuO2 coated specimen, the discharge capacity of which was 131.6 mAh.g(-1) at 10C, as well as a capacity retention of 86% when cycling at 1C rate for 100 cycles. The results showed that the polarization degree and the charge transfer resistance of the pristine material were both decreased by RuO2 coating. In summary, all these findings demonstrate that RuO2-coated high nickel cathode material can be utilized in advanced lithium-ion batteries.