Enhanced Electrochemical Performance of Aqueous Zinc-Ion Batteries Using MnSO4 Electrolyte Additive and α-MnO2 Cathode

Zinc-ion batteries (ZIBs) are an ideal choice for large-scale energy storage due to their high safety, environmental friendliness, and low cost. However, their performance is constrained by challenges related to cathode materials, such as poor conductivity, dissolution of active materials, and structural instability during cycling. In this study, α-MnO2 cathode material with a tunnel structure was synthesized via a hydrothermal method, and MnSO4 was introduced into the ZnSO4 electrolyte to optimize the electrochemical performance of ZIBs. Characterizations through XRD, SEM, and BET revealed excellent crystal morphology and nanorod structures, which provided superior ion transport pathways. With the addition of MnSO4, the discharge specific capacity of ZIBs at 0.1 A g⁻1 was significantly improved from 172.9 mAh g⁻1 to 263.2 mAh g⁻1, the cycling stability was also notably enhanced, namely, after 1000 cycles with the current density of 1 mA cm−2, the capacity settled at 50 mAh g−1, which is a 47.4% increase in relation to the case of absent additive. The experimental results indicate that MnSO4 additives effectively suppress manganese dissolution, improving the rate capability and reducing self-discharge. This study provides a novel approach to the development of high-performance aqueous zinc-ion batteries.