Investigation of polymer electrolyte hybrid supercapacitor based on manganese oxide-carbon electrodes

A hybrid supercapacitor based on manganese oxide, activated carbon and polymer electrolyte was developed and electrochemically investigated. The capacitive performance obtained from the polymer electrolyte based supercapacitor was similar to that of an aqueous electrolyte based supercapacitor, tested for comparison in the same operative conditions. A durability test carried out for 2500 cycles showed stable and slowly increasing performance. The specific capacitance of hybrid supercapacitor was 48 F g⁻¹ (192 F g⁻¹ as a mean one electrode capacitance), in which that of the positive electrode was 384 F g⁻¹ of MnO₂ and that of negative electrode 117 F g⁻¹ of carbon. The impedance analysis evidenced that although the polymer electrolyte based hybrid supercapacitor showed higher resistance compared to that of the liquid electrolyte based supercapacitor, this drawback was counterbalanced by better ion transport features, which were evident at lower frequencies, where similar values of capacitances were obtained from the different supercapacitors.