Synthesis of submicron-sized LiNi0.5Co0.2Mn0.3O2 cathode particles via reverse microemulsion method: Tailoring size, interfacial properties, and enhanced electrochemical performance for lithium-ion battery

Abstract

This study explores the impact of submicron-sized cathode materials on lithium-ion battery performance, an area with limited prior research due to synthetic challenges. Employing the reverse microemulsion method, LiNi0.5Co0.2Mn0.3O2 (NCM) cathode particles with tunable sizes (180 nm to 340 nm) were synthesized. Notably, NCM6.67-4.5, which prepared under the volume ratio of the oil phase to the water phase (i.e. 6.67) and applying 4.5 mL NH4OH as the complexing agent, obtained the largest particle size (340 nm). Further investigation revealed that NCM6.67-4.5 exhibited superior discharge specific capacity (177.54 mAh·g−1) and a high coulomb efficiency (99.5 %). The larger particle size in the submicron range facilitated heightened lithium-ion diffusion rates and reduced polarization. Focused Ion Beam-Scanning Electron Microscopy (FIB-SEM) confirmed that increased particle size diminishes specific surface area, mitigating interfacial side reactions during battery cycling. This research underscores the importance of controlling cathode particle size for optimizing electrochemical performance in lithium-ion batteries.