Enhanced supercapacitor performance of Bi2O3 by Mn doping

Abstract

High-performance electrode material Mn-doped Bi 2 O 3 with a nanorod morphology is synthesized by a simple soft chemical method. Such material keeps the high stability and high ion conduction efficiency of Bi 2 O 3 , while its specific capacity is also enhanced by Mn ions doping treatment. The doping of Mn ions effectively increases the number of oxygen vacancies, modifying the local electron structure, promoting the charge transfer and ion migration of the electrode, leading to high energy density and power density. The mechanism of the electron structure and transfer property affected by Mn doping are also investigated by experimental and theoretical processes. Based on nickel foam substrate, the specific capacitance of the Mn-doped Bi 2 O 3 electrode can reach 1295.6 F g −1 with a current density of 1 A g −1 . It also has a high energy density of 149.25 Wh kg −1 and a high power density of 864 W kg −1 . Furthermore, Mn-doped Bi 2 O 3 also shows good cycle stability of metal oxide, which can maintain 100% coulomb efficiency and 98% cycle retention rate after 5000 cycles. • An effective strategy of doping Mn ions in Bi 2 O 3 is developed. • The doping of Mn ions greatly increases Bi 2 O 3 ’s supercapacitor performance • Existence of Mn 3+ is the main reason for the capacity enhancement.