A High‐Performance Supercapacitor with Well‐Dispersed Bi 2 O 3 Nanospheres and Active‐Carbon Electrodes

A simple and low‐cost method to fabricate Bi 2 O 3 /active‐carbon nanocomposites with high capacitive properties was explored. In particular, the composites synthesized at a bismuth nitrate/active carbon weight ratio of 2:1 exhibited a maximum specific capacitance of 466 F g –1 at a current density of 1 A g –1 and retained up to 335 F g –1 even at a current density of 5 A g –1 . In addition, these composites also showed good capacity over 3000 cycles. The excellent electrochemical properties could be due to their high specific surface area, abundant pore volume, and proper loading of Bi 2 O 3 nanospheres.