A structured CoWO4 synthesized by microwave-assisted hydrothermal process as electrode for hybrid supercapacitor

Abstract

A structured carambola-like CoWO4 was fast prepared by a microwave-assisted hydrothermal method with the help of urea and NH4F. Physical characterization indicated that the as-obtained CoWO4 displayed a large specific surface area, high dispersion and self-selected orientation of crystal growth. Further electrochemical tests presented a high specific capacity of 492.0 C[Formula: see text]⋅[Formula: see text]g[Formula: see text] at 1 A[Formula: see text]⋅[Formula: see text]g[Formula: see text], low internal resistance and excellent cycle stability as 137.3% capacity maintenance after 8000 cycles at 20 A[Formula: see text]⋅[Formula: see text]g[Formula: see text]. These excellent electrochemical properties for the as-obtained material indicate that CoWO4 has great potential as hybrid supercapacitor electrode materials. This work also provides a new and effective solution for regulating the morphology of CoWO4-based hybrid supercapacitor materials to further improve the electrochemical performance.