Enhanced Electrochemical Performance of Li_1.2Mn_0.54Ni_0.13Co_0.13O₂ Cathode with an Ionic Conductive LiVO₃ Coating Layer

Abstract

With the aim to enhance the Li + ion conductivity, an ionic conductor, LiVO 3, has been successfully coated on the surface of lithium-rich layered Li 1.2 Mn 0.54 Ni 0.13 Co 0.13 O 2 cathode materials for the first time. After combining with LiVO 3, significantly improved high-rate capability and cyclic stability of the Li-rich cathode have been achieved due to the enhanced lithium ion diffusion and stabilized electrode/electrolyte interface. Moreover, a stable three-dimensional spinel phase has been generated in the surface region during the coating process, which mitigates the structure deterioration and suppresses the voltage decay and energy density degradation. After optimization, 5 wt % LiVO 3 -coated–Li 1.2 Mn 0.54 Ni 0.13 Co 0.13 O 2 exhibits superior electrochemical performance with a higher reversible capacity of 272 mA h g –1, increased initial Coulombic efficiency of 92.6%, and an excellent high-rate capability of 135 mA h g –1 at 5 C, respectively. The coexistence of an ionic conductor coating layer and the locally transformed spinel structure generated in a one-step approach provides a novel design concept for surface modification on Li-rich Mn-based cathode materials toward high-performance lithium-ion batteries.