Formation of monoclinic α-Bi2O3 nanosheet-assembled hollow spheres as a high-performance electrode for supercapacitor

To improve the specific capacitance of supercapacitor with bismuth oxide, this paper reports hollow nanosheet-assembled α-Bi 2 O 3 spheres prepared by solvothermal method as novel electrode materials. The electrochemical results show that the hollow nanosheet-assembled α-Bi 2 O 3 spheres exhibited a high electrochemical performance with a maximum specific capacitance of 1380.2 F g −1 at a current density of 1 A g −1 , which is the highest specific capacitance achieved to date with bismuth oxide as electrode material, and remarkable rate capability of 84.1% when the current density increased to as high as 15 A g −1 . The reasons for the high capacitance performance of the product are due to the monoclinic α-Bi 2 O 3 with a stable phase and more ion channels to transport and store ions, as well as the hollow spherical structure with porosity, which makes the material fully utilized. In a word, Bi 2 O 3 should be as a promising candidate towards high-performance electrode for pseudocapacitive supercapacitor.