Synthesis of graphene-wrapped ZnMn2O4 hollow microspheres as high performance anode materials for lithium ion batteries

Abstract

Hollow microspheres of ZnMn₂O₄ wrapped by graphene have been successfully synthesized via a facile APS aided method. Characterization results certify that the reduced graphene sheets have been wrapped around the hollow ZnMn₂O₄ microspheres. Charge–discharge testing reveals that ZnMn₂O₄/RGO delivers superior electrochemical properties in terms of specific capacity, cycle stability (1082 mA h g⁻¹ at 100 mA g⁻¹ after 90 cycles) and high rate capability (580 mA h g⁻¹ at 1 A g⁻¹ after 150 cycles). The improved rate capability and cycling performance of the modified ZnMn₂O₄ microspheres are attributed to the incorporated RGO sheets’ perfect synergy collaborating with the hollow structures, which can provide higher electronic conductivity, a shorter Li⁺ diffusion path and also buffer the volume change during Li⁺ insertion and extraction.