Engineering a carbon-coated manganese oxide hierarchical heterostructure cathode for high-performance aqueous zinc-ion batteries

Abstract

The intrinsic qualities of aqueous zinc-ion batteries (AZIBs), such as their exceptional safety, low cost, environmental friendliness, and many other advantages, have led to their widespread recognition as extremely promising energy storage technologies. However, there are still several difficult problems with the present generation of AZIBs, such as low intrinsic electron conductivity, weak reversibility, zinc anode dendrites, and side reactions. Herein, a polydopamine-derived carbon layer in-situ encapsulated hybrid composites (denoted as MnO/MnS@CP) was rationally constructed through simple hydrothermal and carbonization strategies. The results show that the amorphous carbon layer coated on MnO/MnS not only improves the conductivity of the composite, but also acts as a solid skeleton of MnO/MnS nanoparticles to ensure the stability of the MnO/MnS@CP structure. Furthermore, the carbon-MnO-MnS multiphase heterogeneous interface can expose more active sites, offer more conductive routes, and lower the electron and ion transfer impedance. As a result, the MnO/MnS@CP cathode material exhibits outstanding battery performance, particularly in capacity and cycling stability. It achieves an initial capacity of 397.7mAh g⁻¹ at 0.1 A g⁻¹ and retains 347mAh g⁻¹ after 100 cycles, with a low capacity decay rate of 0.13 %, indicating excellent long-term stability. Even at 5 A g⁻¹, the material delivers a capacity of 59.4mAh g⁻¹, demonstrating strong stability and high-rate performance.