Chemically Processed Porous V ₂ O ₅ Thin‐Film Cathodes for High‐Performance Thin‐film Zn‐Ion Batteries

Abstract Thin‐film rechargeable batteries have a wide range of applications due to their unique properties such as small size, thinness, and the ability to power smart devices, including portable electronic devices, medical devices, smart cards, RFID tags, and Internet of Things (IoT) devices. Processing thin‐film electrodes for these batteries generally relies on standard physical vapor deposition technologies. However, producing porous thin‐films using these techniques presents significant challenges. Here, a rapid and cost‐effective chemical route for processing porous vanadium oxide (V ₂ O ₅ ) thin‐film cathodes for application in Zinc‐ion‐based thin‐film batteries (Zn‐TFBs) is explored. The V ₂ O ₅ precursor process uses an industrially viable spraying technique, which not only offers impressive charge storage performance of an areal capacity of 47.34 µAh cm ^{− 2} , areal energy of 50.18 µWh cm ^{− 2} , and areal power of 53 µW cm ^{− 2} at 50 µA cm ^{− 2} in the optimized gel‐electrolyte composition. This study introduces a cost‐effective and industrially viable method for processing highly porous thin‐film cathodes, enabling the production of high‐performance, affordable, and safer thin‐film batteries.