High-performance flexible quasi-solid-state Zn–MnO2 battery based on MnO2 nanorod arrays coated 3D porous nitrogen-doped carbon cloth

Aqueous Zn–MnO2 batteries have great potential as flexible energy storage devices owing to their low cost, high energy density, safety, and environmental friendliness. However, their development is plagued by the poor cycling stability, and the use of heavy zinc foil as the anode is antithetical to the flexible devices. Herein, we construct a high-performance and stable flexible rechargeable quasi-solid-state Zn–MnO2 battery using MnO2 nanorod arrays and tiny Zn nanoparticles uniformly deposited on N-doped porous carbon cloth as the free-standing cathode and anode, respectively. The 3D porous nitrogen-doped carbon cloth substrate with high electric conductivity and good flexibility serves as an ideal support for guest active materials of MnO2 nanorod arrays and tiny Zn nanoparticles, which can effectively buffer the volume change giving rise to good cycling ability. Significantly, the device is able to deliver a remarkable capacity of 353 mA h g−1 and good cycling stability (93.6% after 1000 cycles) in an aqueous electrolyte. Moreover, when using PVA/ZnCl2/MnSO4 gel as the electrolyte, the as-fabricated quasi-solid-state Zn–MnO2 battery still achieves a high energy density of 440 W h kg−1, high power density of 7.9 kW kg−1 and excellent cycling ability. This work heralds new opportunities in the development of high-performance, low-cost, safe and flexible electronic devices.