Enhanced Electrochemical Properties of Polyaniline-Coated LiNi0.8Co0.1Mn0.1O2 Cathode Material for Lithium-Ion Batteries

A polyaniline (PANI)-coated LiNi0.8Co0.1Mn0.1O2 cathode material has been synthesized by a solution method to avoid lithium discharge and structural damage to the coating of active materials. The results of x-ray diffraction, Fourier-transform infrared spectroscopy, and transmission electron microscopy illustrate that PANI has been successfully coated onto the LiNi0.8Co0.1Mn0.1O2 cathode materials. PANI coating can effectively inhibit cationic mixing and reduce the content of surface residual alkali. This coating can also optimize interfacial electrochemical reactions, thereby improving the stability and security of cathode materials. Electrochemical results show that 3 wt.% PANI-coated LiNi0.8Co0.1Mn0.1O2 exhibits an initial discharge capacity of 193.8 mAh g−1 with a capacity retention of 96.25% after 80 cycles at the current rate of 1 C and an initial discharge specific capacity of 162.6 mAh g−1 with capacity retention of 83.02% at 5 C. The rate capability of PANI-coated LiNi0.8Co0.1Mn0.1O2 improves remarkably at high rates (1 C, 2 C, and 5 C). The PANI-coated LiNi0.8Co0.1Mn0.1O2 has significant practical applications for power batteries due to its excellent stability, long cycle ability, and high rate performance.