Improved Electrochemical Performance of LiNi0.8Co0.1Mn0.1O2 Cathode Materials Induced by a Facile Polymer Coating for Lithium-Ion Batteries

Ni-rich LiNi0.8Co0.1Mn0.1O2 (NCM) material has attracted intense attention because of the capacity and cost advantages. However, the poor cycling performance hampers the further development of NCM. As a coating layer, polysiloxane can improve the electrochemical properties of the NCM by eliminating remaining H2O on the surface of NCM and the reaction between HF in electrolyte and NCM, inhibiting the interfacial side reactions. Compared with the pristine NCM, the cycling performance of the NCM cathode coated with polysiloxane is significantly improved. The capacity retention of NCM coated with polysiloxane is 91.5% at 1 C after 120 cycles, while pristine NCM only maintains 71.4%. This study provides a method to alleviate the effects of interfacial side reactions and HF corrosion on NCM performance degradation after many cycles.