Improved pseudo-capacitive performance of manganese oxide films synthesized by the facile sol-gel method with iron acetate addition

Manganese oxide electrodes possessing pseudo-capacitance behaviors were successfully made with a simple sol-gel method. The experimental results showed that the specific capacitance was 101.2 F/g for pure manganese oxide films after annealing at 300 °C. However, the specific capacitance increased to 232.3 F/g with iron acetate (1.0 mol% Fe) addition and after annealing at 350 °C. The surface morphology observations revealed that the annealing temperature of 350 °C produced a higher surface area film with smaller pores. X-ray diffraction results showed that the manganese-iron oxide was composed of Mn3O4 and Mn2O3 phases, without iron oxide diffraction peaks. The manganese-iron oxide electrode with Mn3O4 and Mn2O3 phases exhibited good electrochemical performance and capacitance efficiency.