Influence of electrode mass-loading on the properties of spray deposited Mn3O4 thin films for electrochemical supercapacitors

• Spray deposition of Mn3O4 electrodes with various mass-loading
• Mn3O4 exhibited ideal capacitive behavior in a voltage window of − 0.2 to 0.4 V.
• Specific capacitance and charge–discharge periods are electrode thickness dependent
• Highest specific capacitance of 597 F·g− 1
• Mn3O4 electrode with 0.64 mg cm− 2 mass-loading possess good power-energy density.

Mn3O4 thin film electrodes with various mass-loadings are deposited by spray pyrolysis using aqueous/organic solvent mixture. The influence of mass-loading on the electrochemical properties of Mn3O4 thin film electrodes is studied. The results showed that, the as-prepared Mn3O4 exhibited ideal capacitive behavior in a voltage window of − 0.2 to 0.4 V. With increasing of Mn3O4 mass-loading from 0.47 mg cm− 2 to 0.64 mg cm− 2, the specific capacitance calculated from the cyclic voltammetry curves at 5 mV s− 1 increased from 520 to 597 F·g− 1. The specific energy and specific power are found to be 3735 Wh kg− 1 and 12.45 W kg− 1 respectively at a current density of 4.0 A·g− 1 for film having 0.64 mg cm− 2 mass-loading. Ragone plots indicated that the Mn3O4 electrode with 0.64 mg cm− 2 mass-loading possessed good power-energy density characteristics. The electrochemical performances of 0.64 mg cm− 2 mass-loading Mn3O4 thin film electrode suggest suitability of this material as a potential electrode material for supercapacitors.