Investigation of electrochemical performance and stability of electrodeposited Mn3O4 thin films in different aqueous electrolytes for its application in flexible supercapacitors

An electrochemical capacitor has attracted significant attention, mainly due to its long life cycle, high power and energy densities. Among the various metal oxides, manganese oxide is well known and extensively studied as an electrode in an energy storage system. In our work, we present a simple, effective and inexpensive approache to deposit thin film under ambient temperature. The manganese oxide thin film is prepared on flexible stainless steel (SS) sheet as substrate by potentiodynamic mode of electrodeposition and employed for supercapacitor application. The deposition is carried out by repeating the number of cycles in the potential region between -1V to 1V at a scan rate of 50 mV/s. The effect of heat-treatment on the electrode is also examined. The electrochemical performance of the thin electrode is evaluated by using a cyclic voltammetry measurement and charge/discharge test in three different electrolytes i.e. 1M Na2SO4, 1M NaOH and mixed 1M KOH with 0.04 M K4Fe(CN)(6). The material exhibits a large pseudo-capacitance with better stability over a potential window of -0.1V to 1V in 1 M Na2SO4 electrolyte as the phase of material has been changed. Hence it proves to be a good candidate material for the supercapacitor electrode.

Automated summary

The study presents a simple, effective, and inexpensive approach to deposit thin film of manganese oxide on a flexible stainless steel substrate for supercapacitor application. The impact of heat treatment and different electrolytes on the electrochemical performance of the electrode is investigated. The material demonstrates a large pseudo-capacitance and stability in 1M Na2SO4 electrolyte, making it a promising candidate for supercapacitor electrodes.