MnO₂ Nanosheet-Assembled Hollow Polyhedron Grown on Carbon Cloth for Flexible Aqueous Zinc-Ion Batteries

Aqueous zinc-ion batteries (ZIBs) have been considered as prospective alternatives for lithium-ion batteries, which are able to serve as power sources for next-generation wearable and flexible devices, owing to the merits of abundant zinc resources and high safety of aqueous electrolyte. However, the lack of suitable cathode materials with flexibility for ZIBs hinders their further application. Herein, a novel cathode material [i.e., MnO₂ nanosheet-assembled hollow polyhedron anchored on carbon cloth (MnO₂ /CC)] was prepared through a rapid hydrothermal method by using ZIF-67 as self-sacrificing template. When tested in an aqueous ZIB, the MnO₂ /CC delivered a high reversible capacity of 263.9 mAh g^-1 at 1.0 A g^-1 after 300 cycles, far exceeding those of the commercial MnO₂ electrode. More importantly, benefiting from the unique structural advantages, a flexible ZIB assembled based on the MnO₂ /CC displayed a stable output voltage of 1.53 V and a specific capacity of 91.7 mAh g^-1 at 0.1 A g^-1 after 30 cycles. It also successfully lit LED bulbs even under different bending angles, showing good flexibility. This research contributes to the development of MnO₂ -based cathode materials for high-performance flexible ZIBs.