Cu ion induced morphology change of hematite microspheres as lithium ion battery anode material by solvothermal synthesis

Abstract

Transition metal oxides (TMOs) have been commonly considered as promising anode materials for next generation lithium ion battery (LIB) due to their high specific capacity, environmental friendliness, low cost and natural abundance. Herein, we demonstrate that hematite (α-Fe2O3) microspheres of different morphologies can be easily modulated with the assistance of small amount of Cu ions during solvothermal synthesis. Through combined spectroscopic, structural and compositional analysis, the root of hematite morphology change and incurred electrochemical property enhancement were investigated in detail. It was found that Cu ions play a great role at different stage of the synthesis, namely guiding particle growth at its low concentration, whereas being reduced to Cu nanoclusters at its high concentration, executively enhancing overall electrochemical performance of the anode. To explain the particle morphology change induced by Cu ion concentration, a particle growth mechanism involving the interaction of multiple reactions was proposed and studied accordingly.