Boosting lithium ion storage of lithium nickel manganese oxide via conformally interfacial nanocoating.

In this work, a conformally interfacial nanocoating strategy is introduced to enhance the lithium ion storage performance of LiNi0.5Mn1.5O4 (LNMO). Stable cycling of LNMO is achieved through La2O3 coating at both room and elevated temperatures. A series of La2O3-coated LNMO composites with various coating contents ranging from 0 to 3 wt% is prepared, and their electrochemical behaviors are systematically investigated. Among them, the 2 wt% La2O3-coated LNMO cathode presents the best comprehensive lithium ion storage performance; for instance, it retains more than 75% capacity retention after 500 cycles at room temperature and 93% capacity retention after 50 cycles at an elevated temperature of 55 °C with 1C rate. Moreover, the modified samples show more stable plateau potential than the pristine one during the cycling process. It is believed that the introduction of the La2O3 nanocoating layer can effectively suppress side reactions between electrode and electrolyte, thus maintaining stable structure of electrode material and reducing polarization during cycling. Our work provides an effective approach to improve the electrochemical stability of LNMO high-potential cathode for future large-scale applications of enhanced lithium ion batteries with high energy density and long cycle life.