Surface Modification of Potassium Vanadate with Nanosized Ruthenium Dioxide for Use in High‐Performance Cathode in Aqueous Zinc‐Ion Batteries

Abstract Vanadium‐based compounds as promising cathode materials for aqueous zinc‐ion batteries (AZIBs) have aroused significant attention owing to their multiple oxidation states, layered open‐framework structure, and excellent zinc storage performance. However, the low intrinsic conductivity, slow reaction kinetics and poor structure stability greatly hindered their widespread application. Herein, nanostructured K0.486V2O5@RuO 2 composite, nanorod‐like potassium vanadate (K0.486V2O5) surface‐modified with nanosized ruthenium dioxide (RuO 2 ), was successfully prepared using a facile one‐step hydrothermal method and applied for cathode material of AZIBs. Benefiting from the surface modification of conductive and pseudo‐capacitive nanosized‐RuO 2 , the K0.486V2O5@RuO 2 composite electrode demonstrates enhanced electrochemical properties and accelerated kinetics behavior, including superior rate capability with reversible capacities of 265, 231, 204, 184, 158, and 115 mAh·g −1 at current densities of 0.1, 0.2, 0.5, 1, 2, and 5 A·g −1 , respectively, and long cycle life with 83% capacity retention after 5000 cycles at 5 A·g −1 , and 87% retention after 10,000 cycles at 10 A·g −1 . This work provides new insights into the development of high‐performance vanadium‐based cathode materials for AZIBs.