Hydrothermally Synthesized ZnMn2O4@GO Cathode Enhances Zinc-Ion Kinetics and Cycling Stability for Aqueous Zinc-Ion Batteries.

Abstract

Spinel-type ZnMn₂O₄ has been identified as a cathode that demonstrates considerable potential material for zinc-ion batteries (ZIBs). In this study, the synthesis of ZnMn₂O₄@GO composite material was conducted using a hydrothermal method. The electrochemical performance of the composite material was found to be significantly enhanced, a phenomenon that was primarily ascribed to the substantial specific surface area and exceptional conductivity of graphene, which improved the diffusion kinetics of zinc ions at the electrode-electrolyte interface. At a current density of 50 mA g^-1, the discharge capacity of the ZnMn₂O₄@GO composite electrode was 186.4 mAh g^-1, much higher than that of ZnMn₂O₄ (133.3 mAh g^-1). Moreover, after 1000 charge-discharge cycles at a current density of 1000 mA g^-1, the discharge capacity of ZnMn₂O₄@GO composite electrode was 50% higher than that of ZnMn₂O₄.