Facile microwave-assisted synthesis of Ce-doped Bi₂O₃ for efficient hybrid supercapacitors

Bismuth trioxide (BT) is considered a fascinating anode material for hybrid supercapacitors (HSCs) due to its high theoretical capacity, but the low conductivity limits further applications. With this in mind, Ce-doped Bi2O3 (Ce-BT) nanoflower spheres were synthesized by a facile and rapid microwave-assisted solvothermal method for HSCs anode materials. It is found that the morphology of BT could be controlled by Ce doping from stacked nanosheets to well-dispersed nanoflowers spheres and producing abundant amorphous regions, thus expediting the ion transport rate. Consequently, when the added Bi to Ce molar ratio is 40:1 (Ce-BT-40), it exhibited a specific capacity of 220 mAh g(-1) at 0.5 A g(-1). Additionally, when fabricating HSCs with as-prepared Ce-BT-40 and CeNiCo-LDH, an energy density of 59.1 Wh kg(-1) is provided at a power density of 652 W kg(-1). This work not only reveals the mechanism of the effect of Ce doping on the electrochemical properties of BTs, but also proposes a rapid synthesis method of Ce-BTs by microwave-assisted solvent method, which provides new insights for building advanced HSCs with high energy density and low cost.