Innovative integrated carbon paper supported Bi/rGO/MnO2 cathode with dual redox reactions for aqueous zinc-ion batteries

Abstract

Developing cathode materials with dual redox reactions is an effective strategy to improve the electrochemical performance of aqueous zinc-ion batteries (AZIBs), and rational selection of the two electroactive components is the key to achieving this target. Herein, an integrated carbon paper supported Bi/rGO/MnO2 cathode is prepared via a two-step in situ growth process, in which metallic bismuth (Bi) and manganese dioxide (MnO2) are served as two types of electroactive components to realize dual redox reactions. The introduction of reduced graphene oxide (rGO) mitigates the interfacial mismatch of Bi and MnO2, meanwhile further increasing the electrochemical activity by reducing the size of Bi and preventing its self-aggregation. Featuring nanostructured Bi and MnO2, the integrated cathode enables dual redox reactions with enhanced reaction kinetics. This structural and compositional refinement of the Zn//Bi/rGO/MnO2 battery leads to superior electrochemical performance, evidenced by a significant specific capacity (388.3 mAh g−1 at 0.1 A g−1), high energy density (464.6 Wh kg−1) and great rate performance. This work underscores the potential of using MnO2 and Bi as dual electroactive components for AZIBs cathode, providing a pathway towards high performance energy storage systems.