Double Conductor Coating to Improve the Structural Stability and Electrochemical Performance of LiNi_0.8Co_0.1Mn_0.1O₂ Cathode Material

LiNixCoyMn1–x–yO2 (NCM) is identified as the most typical cathode material on account of high specific capacity, cheaper cost, and good security. Nevertheless, the storage environment of NCM is inferior, whose surface lithium compounds could cause side reactions and corrode the electrode. Herein, we propose a strategy to synergistically modify the NCM cathode material with the ionic conductor (LiBO2) and electronic conductor [poly(3,4-ethylenedioxythiophene), PEDOT], whose mechanism was comprehensively investigated in detail using material characterizations and electrochemical measurements. Benefiting from the multiple effects of the dual conductor, surface residual alkali and impurities of NCM were significantly reduced, and the corresponding side reactions was effectively inhibited, which further improved the interfacial stability and slowed down the formation of rock salt impurity phases. As a consequence, the modified sample exhibited an outstanding electrochemical property with a retention of 95.44% at 1 C after 100 cycles, which provides a new understanding for the modification strategy and efficient service of nickel-rich cathode materials for lithium-ion batteries.