Al2O3@LiMn2O4 nanoparticles cathodes for high-rate Li-ion batteries

Abstract

LiMn₂O₄ nanoparticles (LMO) are a favorable cathode material because of their relatively higher operating voltage and cost-efficacy. However, capacity fading, structural degradation, and side reactions during charge–discharge cycles often limit its usefulness. We investigated the performance of Al₂O₃-coated LiMn₂O₄ nanoparticles (Al₂O₃@LMO) as an active cathode material using the sol–gel method. Electrochemical measurements such as CV, EIS, and GITT revealed improved charge transfer kinetics and reduced resistance for the coated material with a higher diffusion coefficient. The coated materials show higher GCD characteristics and ∼ 128 mAh g⁻¹ discharge specific capacity at 0.2C with fast charge–discharge characteristics at 5C rate. The Al₂O₃@LMO exhibits capacity retention of 90 % higher than that of pristine material for 500 cycles at a 5C rate.