Ionic Conductive Interface Boosting High Performance LiNi0.8Co0.1Mn0.1O2 for Lithium Ion Batteries

LiNi0.8Co0.1Mn0.1O2 (NCM) is a highly prospective cathode material for high energy density Li-ion batteries (LIBs). Nevertheless, poor cycling performance and rate capability at high cutoff voltages have dramatically blocked its further commercialization. In this study, an ionic conductive interface has been demonstrated to enhance the NCM electrochemical property at the high cutoff voltage of 4.5 V on account of the existence of a Li-ion conductor of Li2SnO3. In comparison to SnO2, Li2SnO3 causes a smoother Li-ion diffusion at the engineered interfaces, lower polarization, slower capacity drop, and voltage fading as well as better H2/H3 reversibility upon cycling. Importantly, it is confirmed that excellent diffusion is beneficial to preservation of reversible phase transition and reduction of polarization, which are directly relative to the superior cyclability and rate capability. This work reveals that building an excellent ionic diffusion interface is feasible for Ni-rich cathodes with simultaneous high capacity and stable cyclability.