Unlocking the potential of spinel MnV2O4 for highly durable aqueous zinc-ion batteries

Aqueous zinc -ion batteries (AZIBs) have received comprehensive attention as promising candidates for largescale energy storage owing to high security, low cost, and environmental friendliness. Developing appropriate cathode materials is of great significance for high -efficiency Zn 2+ storage. Herein, we proposed an efficient in -situ electrochemical pretreatment strategy to unlock the potential of non -electrochemically active spinel MnV 2 O 4 via an irreversible phase reconstruction from crystalline structure to short-range ordered amorphous state. Specifically, the reconstructed electrodes not only deliver abundant active sites for Zn 2+ ions accommodation, but also shorten diffusion paths for rapid reaction kinetics, thus achieving superior electrochemical properties. As revealed, the optimized electrodes present a prominent specific capacity of 445 mA h g -1 at 0.1 A g -1 , a high capacity retention of 73.1 % over 2000 cycles at 5 A g -1 , as well as exceptional energy density of 335 W h kg -1 and power density of 176 W kg -1 based on the mass of cathode. In addition, the reaction mechanism during Zn 2+ions storage process is systematically investigated by ex -situ X-ray diffraction and X-ray photoelectron spectroscopy. This in -situ electrochemical conversion mechanism sheds light on a new methodology of designing desirable cathode materials for aqueous ion batteries.