Pomegranate‐Inspired Cathodes Mitigate the Mismatch Between Carrier Transport and High Loading for Aqueous Zinc‐Ion Batteries

Abstract

The development of high‐energy‐density aqueous zinc‐ion batteries requires the preparation of cathodes with a thick layer of active material. However, the insulating nature and dissolution of vanadium‐based oxides lead to low areal capacity (0.1,1 mA h cm−2) during the charge/discharge cycle. Herein, V2O5 nanospheres are generated by anchoring onto the laser‐induced graphene (LIG) conductive network through defect‐induced adsorption, resulting in the formation of pomegranate‐like V2O5@LIG composites. The unique and abundant defect structure in the honeycomb LIG can trigger the formation of uniform V2O5 nanospheres with high specific surface area and interact electronically with V2O5 to enhance the electrical conductivity of the cathode materials up to four orders of magnitude. In contrast to conventional carbon materials that can cause steric hindrance for ion transport, the micropores within LIG shorten the ion transport path through the cathode. Concurrently, the pomegranate‐like encapsulated structure effectively prevents cathode material corrosion. Under a high‐loading mass of 17.1 mg cm−2, the full cell is stably cycled for 200 cycles, possessing a 92.5% capacity retention, and achieving a high areal capacity of 6.05 mA h cm−2.