Hierarchical Carbon Nanosheet Embedded MnO_x Cathode for High-Performance Aqueous Zinc-Ion Batteries

Aqueous zinc-ion battery is one of the candidates for the next generation batteries due to its reliable safety, environmental friendliness and low cost. While the poor structurally stability and limited cyclic reversibility of the cathode restricts its practical application. In this work, we elaborately design hierarchical three-dimensional (3D) carbon networks (CNs) for the embedding of non-stoichiometry MnO_x with abundant defects (MnO_x/CNs), which provide 3D diffusion pathway and efficient electrochemical active sites for zinc-ion storage. The as-designed Zn//MnO_x/CNs battery delivers high energy density of 452.2 Wh kg⁻¹ at a power density of 133.0 W kg⁻¹, much superior to that of MnO₂/CNs and pristine MnO₂. Moreover, defective manganese species experience stable phase transformation during charging/discharging process, providing a long-term cycling performance with a high reversible capacity of 263.3 mAh g⁻¹ at 1 A g⁻¹ after 1000 cycles.