Exploiting the synergistic effect of multiphase MnO2 stabilized by an integrated conducting network for aqueous zinc-ion batteries

Abstract

δ-MnO₂ is a typical oxide with a large layered structure for rapid Zn-ion (Zn²⁺) accommodation capability and widely studied as a cathode material in aqueous Zn-ion batteries (ZIBs). However, structural instability and Mn dissolution are two major obstacles for its application in the fabrication of ZIBs with a long cycle life. Herein, a “three-in-one” strategy was applied to design a multiphase MnO₂-based composite (δ-MnO₂ and α-MnO₂) on carbon cloth through constructing an integrated continuous conducting network of poly(3,4-ethylenedioxythiophene) (PEDOT), and the aforementioned issues in δ-MnO₂ were tackled without compromising on rapid Zn²⁺ transportation, which originates from the excellent hydrophilicity and the synergism of multiphase MnO₂ and an integrated conducting network. When applied as the cathode material for aqueous ZIBs, a large capacity release of 360 mA h g⁻¹ at 0.1C and impressive durability over 860 cycles with 78% capacity retention at 1C were achieved, representing a promising cathode structure design for MnO₂ based cathodes.