Simultaneously Dual Modification of a Ternary Cathode Material by Aluminum Bis(oxalato)borate-Based Electrolyte

Poor cycle performance is the critical challenge for commercialization application of layered LiNixCoyMnzO2 (x + y + z = 1) cathode materials. Herein, the optimized LiNi0.493Co0.214Mn0.293O2 (Al-LNCM) is modified by Al3+ doping and passivation-film coating via the previous cycles using aluminum bis(oxalato)borate (Al(BOB)3)-based electrolyte. Results show that the electrochemical performance of Al-LNCM is significantly improved after dual modification, especially for the cycling and rate performances. On one hand, Al3+ doping maintains the layered structure stability and suppresses the degree of Li+/Ni2+ cation mixing, thereby inhibiting structural degradation and facilitating the transport of Li+ ions. On the other hand, the prior formation of the Al- and B-containing surface coating can block the direct contact between the electrode and the electrolyte, which inhibits excessive electrolyte decomposition and undesirable interface side reactions.