Synergistically MXene-reinforced triple redox metal-organic coordination for constructing long-life aqueous zinc-ion batteries

Abstract

MXene exhibits promising application prospects in aqueous zinc-ion batteries (AZIBs) owing to its excellent electrical conductivity, layered ion transport channels, and hydrophilic surface chemistry. However, intrinsic limitations such as severe restacking and insufficient electrochemically active sites hinder further performance enhancement. High entropy (HE) nanomaterials, with multicomponent synergy, offer abundant redox-active sites and improved stability, providing an effective solution. In this work, we propose a composite strategy that integrates MXene with multiple active sites of HE nanomaterials. By precisely regulating the ultrasonic exfoliation degree of MXene, the coating morphology of the HE nanomaterials surface can be precisely controlled, enabling simultaneous optimization of charge transport of the electrode. Two-dimensional graphene oxide (GO) is used as a reference material to demonstrate that MXene provides superior electrical conductivity, ion diffusion, and interfacial stability. In situ and ex situ characterization confirm the electrochemical reaction mechanism of the optimized HE/M-2 composite during the charge-discharge process. When applied as a cathode material in soft-pack batteries and semi-solid-state batteries, the HE/M-2 composite demonstrated excellent cycling stability, safety, and practical performance. These results underscore the strong potential of HE/MXene composites for flexible and wearable energy storage applications.