Synthesis and Capacitive Properties of Mesoporous Tungsten Oxide Films Prepared by Ultrasonic Spray Deposition

Mesoporous tungsten trioxide (WO₃) films are prepared by the combination of the template-assisted sol-gel method and ultrasonic spraying deposition (USD) for supercapacitors, and then the surface morphology and electrochemical performance of the films are studied. Compared to WO₃ prepared by the traditional hydrothermal synthesis and spin coating method, the films obtained by USD exhibit advantages such as low cost, minimal material usage, and suitability for large-area in-line manufacturing. Additionally, the mesoporous structure of USD-produced films is also supportive of ion transportation. Due to the high specific surface area of WO₃ films deposited by USD, it is a material capable of use in a high-performance energy storage device. Through the control of spray coats, the film thickness and specific capacitance can be effectively controlled. Electrochemical measurements show that the mesoporous WO₃ films possess excellent electrochemical performance with a maximum specific capacitance of 109.15 F/g at 0.5 A/g. The cycling performance up to 5000 cycles of mesoporous WO₃ films is due to the stable nature of nanocrystalline produced by the combination of USD and sol-gel chemistry.