SiO2 Coated Li-rich Layered Oxides-Li1.2Ni0.13Mn0.54Co0.13O2 for efficient energy storage applications

Abstract

Lithium ion batteries (LIBs) are attractive for energy storage application. In this regard, lithium rich layered oxides (LLOs), are considered viable cathodes due to their tempting properties such as lower production cost, faster manufacturing process, excellent reversible capacity, and better electrochemical performance at high voltages. Despite these properties, LLOs lack in cyclic stability and inferior capacity retention. This study proposes a surface modification technique to overcome the above-mentioned limitations in which a layer of silica (SiO2) has been coated on the particles of Li1.2Ni0.13Mn0.54Co0.13O2.TheLi1.2Ni0.13Mn0.54Co0.13O2 wassynthesized by a sol-gel process and then coated with SiO2 (SiO2=1.0 wt. %, 1.5 wt. %, and 2.0 wt. %). The coatings were undertaken through a dry ball milling technique. Different characterization test such as X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), Transmission electron microscopy (TEM), elemental mapping, and X-ray photoelectron spectroscopy (XPS), were utilized to prove phase pure material formation and identify the SiO2 layer on the surface of Li1.2Ni0.13Mn0.54Co0.13O2. The electrochemical measurements, confirm the improvement in capacity retention and cyclability of SiO2 coated Li1.2Ni0.13Mn0.54Co0.13O2 samples with reference to the uncoated samples. This improvement can be ascribed to the protective and barrier effect of the coated layer on the LLOs particles avoiding any unwanted side reactions when the cathode is exposed to the electrolyte. A small trade-off between electrochemical performances and the coating thickness confirms the best efficiency of 1 wt.% SiO2 coated Li1.2Ni0.13Mn0.54Co0.13O2 when compared to other coated samples.