Mn3O4@C core–shell composites as an improved anode for advanced lithium ion batteries

Abstract

Rationally designed nanocomposites with effective surface modification are important to improve the electrochemical performance of Li-ion batteries. Carbon coatings as an economical and practically feasible approach, which would provide good conductivity and promote Li-ion diffusion, leading to improved electrochemical performance. Mn₃O₄@C core–shell nanorods were prepared using the synchronous reduction and decomposition of acetylene. The resulting Mn₃O₄@C core–shell nanorods possess a one dimensional shape, porous structure and uniform carbon layer (∼3 nm), which result in electrochemical stability. When tested as anodes, they deliver a specific capacity of 765 mA h g⁻¹ after 100 cycles at a current density of 500 mA g⁻¹, which is considerably higher than pure Mn₃O₄ nanorods. Even at a current density of 2 A g⁻¹, the Mn₃O₄@C core–shell nanorods can maintain 380 mA h g⁻¹. Their excellent lithium storage performance can be ascribed to the uniform carbon coating layer as well as their unique one dimensional porous structure.