Uniform and porous Mn-doped Co3O4 microspheres: Solvothermal synthesis and their superior supercapacitor performances

Uniform and porous Mn-doped Co₃O₄ microspheres (Mn@Co₃O₄ MSs) assembled with many nanoparticles (NPs) were prepared through an initially solvothermal reaction and subsequent annealing treatment at 550 ^oC in air. These Mn@Co₃O₄ MSs had an average diameter of about 9?μm and possessed a BET specific surface area of 70.4?m²/g. The pore diameter was mainly centered at 12.3?nm and the mean pore size was measured to be 15?nm. When the Mn@Co₃O₄ MSs were used as electrode material for supercapacitors, the electrochemical performances were assessed in 2?M KOH aqueous solution using a typical three-electrode configuration. Such Mn@Co₃O₄-MSs-modified electrode exhibited a highly specific capacitance of 773?F/g at 1 A/g, 62.7% rate capability at 16 A/g, and 73.9% capacitance retention of its original value after 5000 cycles at 5 A/g. The excellently electrochemical behaviors indicate that such Mn-doped Co₃O₄ MSs can be used as a superior electrode material for advanced supercapacitors in the future. The current synthesis strategy is facile and can be further employed to prepare other electrode materials with outstanding electrochemical performances.