Templated manganese oxide by pyrolysis route as a promising candidate cathode for asymmetric supercapacitors

The manganese oxides electrode material for electrochemical capacitor has been prepared with degreasing cotton as templates. The microstructure characterization figured that the constructed quasi-columnar formation is composed of manganese oxides nanoparticles after removal of template. The generated amorphous outlayer provides fast ion diffusion and improvement of structural stability. Consequently, electrochemical performance presented that 0.9 mg, 1.6 mg and 2.7 mg active material loaded on the pressed Ni foam have an excellent capacitance of 214, 189 and 154 F g⁻¹, respectively. With constructed by manganese oxides and active carbon, an asymmetric device delivered an optimal specific energy of 38.4 Wh kg⁻¹ at the specific power of 315 W kg⁻¹. The quantitative experiments have further been performed to investigate the correlation of capacitive contribution and scan rates in detail.