Improved electrochemical performance of SiO2-coated Li-rich layered oxides-Li1.2Ni0.13Mn0.54Co0.13O2

Lithium-rich layered oxides (LLOs) such as Li(1.2)Ni(0.13)Mn(0.54)Co(0.13)O(2)are suitable cathode materials for future lithium-ion batteries (LIBs). Despite some salient advantages, like low cost, ease of fabrication, high capacity, and higher operating voltage, these materials suffer from low cyclic stability and poor capacity retention. Several different techniques have been proposed to address the limitations associated with LLOs. Herein, we report the surface modification of Li(1.2)Ni(0.13)Mn(0.54)Co(0.13)O(2)by utilizing cheap and readily available silica (SiO2) to improve its electrochemical performance. Towards this direction, Li(1.2)Ni(0.13)Mn(0.54)Co(0.13)O(2)was synthesized utilizing a sol-gel process and coated with SiO2(SiO2 = 1.0 wt%, 1.5 wt%, and 2.0 wt%) employing dry ball milling technique. XRD, SEM, TEM, elemental mapping and XPS characterization techniques confirm the formation of phase pure materials and presence of SiO(2)coating layer on the surface of Li(1.2)Ni(0.13)Mn(0.54)Co(0.13)O(2)particles. The electrochemical measurements indicate that the SiO2-coated Li(1.2)Ni(0.13)Mn(0.54)Co(0.13)O(2)materials show improved electrochemical performance in terms of capacity retention and cyclability when compared to the uncoated material. This improvement in electrochemical performance can be related to the prevention of electrolyte decomposition when in direct contact with the surface of charged Li(1.2)Ni(0.13)Mn(0.54)Co(0.13)O(2)cathode material. The SiO(2)coating thus prevents the unwanted side reactions between cathode material and the electrolyte. 1.0 wt% SiO2-coated Li(1.2)Ni(0.13)Mn(0.54)Co(0.13)O(2)shows the best electrochemical performance in terms of rate capability and capacity retention.