One-step direct fabrication of manganese oxide electrodes by low-temperature thermal decomposition of manganese formate-amine ink for supercapacitors

A one-step direct fabrication of thin-film manganese oxide electrodes was accomplished via low-temperature thermal decomposition of inks composed of manganese formate (Mnf), alkylamines, and hexanol. As complexing agents, amines were used in molar ratios of Mnf:amine that ranged from 1:1 to 1:4. Prepared inks were directly coated onto the substrate, and then calcined at 170–210 °C under air. Cyclic voltammetry and charge/discharge measurements of the thin films were conducted in an electrolyte solution. Following immersion, the specific capacitance of the electrodes increased and eventually reached a constant value. Based on the results of cyclic voltammetry (CV) at 1 mV s−1, a thin-film electrode fabricated at 180 °C from Mnf-octylamine-hexanol ink at a molar ratio of 1:3:0.5 had the highest level of specific capacitance at 400 F g−1. CV measurement at 1000 cycles revealed a deterioration of specific capacitance of only 5%, which indicates good stability for this thin-film electrode