Nanostructure Design of MnO₂/Partially Oxidized Graphene Nanocomposite Cathode via One-Step Pulse Potential Strategy: Toward Ultralong-Life Zinc-Ion Batteries

Abstract

MnO2 has garnered significant interest as a cathode material for aqueous zinc-ion batteries (ZIBs) owing to its cost-effectiveness and abundance of manganese. Nevertheless, its practical application is hindered by significant volume changes during charge/discharge processes, along with its intrinsic poor conductivity. In this study, we have designed a nanocomposite structure by concurrently synthesizing MnO2 and electrochemically unzipping multiwalled carbon nanotubes (MWCNTs) into partially oxidized graphene nanosheets using a one-step pulse potential electrodeposition method. This in-situ generated MnO2/partially oxidized graphene nanostructure, employed as a cathode material in ZIBs, displays an impressive reversible capacity of 314.7 mA h g–1 at a rate of 0.1 A g–1, along with outstanding capacity retention of 94.2% after 3000 cycles at 2 A g–1. The remarkable electrochemical performance can be ascribed to the improved electronic conductivity, remarkable structural stability, and substantial surface area of the electrode. Consequently, our study introduces a promising strategy for fabricating high-performance and long-lasting cathodes for ZIBs.