High-performance spinel LiMn2O4@carbon core–shell cathode materials for Li-ion batteries

Abstract

A core–shell-type spinel LiMn₂O₄/carbon composite was synthesized by a simple and cost-effective mechanofusion method (dry particle coating) with a highly uniform coating. Electrochemical characterizations demonstrated that the surface-engineered core–shell-like material exhibited superior rate retention as well as cycling stability than pristine LMO due to improved intrinsic conductivity and easy electrolyte access. As a result, in the half-cell configuration, the core–shell carbon composite delivered reversible specific capacity of 103 mA h g⁻¹ after 1000 cycles at 0.75C with 82% capacity retention; however, the pristine material showed specific capacity of 78 mA h g⁻¹ and 76% capacity retention after 600 cycles. Similarly, in the full cell studies, the core–shell material exhibited 70% capacity retention, whereas the pristine material retained only 53% after 1000 cycles at 0.1 A g⁻¹. The spinel LiMn₂O₄@carbon core–shell material obtained by the mechanofusion method may be a practical cathode material in high-performance lithium-ion batteries toward high energy applications.