Synergistic Effect of Particle Size and In‐Situ Surface Coating on the Electrochemical Performance of Lithium Nickel Manganese Oxide Cathode

A higher areal mass loading of the battery electrode substantially reduces the number of manufacturing steps. It helps achieve the preferred total energy and also saves separator costs. In the present study, the limitations such as capacity fading and cathode stability of a higher areal mass loading cathode (≈10 mg/cm 2 ) are addressed by adapting post‐ball milling and surface coating of active material. Here, LiNi 0.5 Mn 1.5 O 4 (LNMO), synthesized by a solid‐state synthesis route, was subjected to wet ball milling with various durations to obtain a broad range of particle sizes, which helps to improve the packing density of the cathode. The cycling stability and capacity retention of LNMO were further improved by in‐situ surface coating with cyclized polyacrylonitrile (c‐PAN) with 10, 8, and 6 wt%. The cathode chemistry of pristine LF‐0h and LF‐96h shows better capacity and energy density; however, cycling stability improvement can be governed by synergy between particle size and surface modification by means of c‐PAN coating. Among different wt% coatings, the 8 wt% c‐PAN coated LNMO shows ≈88% capacity retention after 100 cycles at 2 C, indicating c‐PAN as a potential surface modifier to improve LNMO cathode performance even at higher C‐rate.