Synthesis of Mn 2 O 3 @Mn(Bi)OCl Composite and Its Supercapacitive Behavior

Mn 2 O 3 @Mn(Bi)OCl composite for supercapacitor were successfully synthesized via a facile solid-phase method using Bi(NO 3 ) 3 and MnCl 2 with molar ratio of 2 : 1 as precursors. The Mn 2 O 3 @Mn(Bi)OCl composite were characterized by X-ray diffraction, scanning electron microscopy, thermogravimetry and differential scanning calorimetry and Brunauer–Emmett–Teller surface area measurements, respectively. Cyclic voltammetry and galvanostatic charge/discharge technique were performed for the Mn 2 O 3 @Mn(Bi)OCl mix-crystals in 1 M Na 2 SO 4 aqueous solutions; the specific capacitance of Mn 2 O 3 @Mn(Bi)OCl was about 203 F g ‒1 at the current density of 1 A g –1 with a long life time, owing to the high power density and the large surface area, good conductivity, and high stability of the of Mn 2 O 3 @Mn(Bi)OCl composite.