Superior performance of electrodeposited CoMnS as novel electrode material for supercapattery devices

A series of cobalt manganese sulfide (CoMnS) grown directly on Ni foam substrate via co-electrodeposition technique to study an appropriate choice of deposition cycle numbers of cyclic voltammetry at a fixed scan rate. The binder free electrodes have been fabricated from a quick synthesis methodology by evaluating the binary metal sulfides for achieving an extremely high energy storage. By carefully selecting the synthesis methodology and ingredients, CoMnS displayed an excellent electrical conductivity and low internal resistance, which makes them a promising contender for energy storage applications. S2 electrode having 12 number of deposition cycles portrayed high electrochemical performance enactment by means of 2297 F/g specific capacitance from cyclic voltammetry (CV) at 3 mV/s, while 2291 F/g from galvanostatic charge discharge (GCD) at 10 A/g. The S2 electrode have smaller ESR value calculated from EIS analysis that elucidated high conductance. Furthermore, the hybrid supercapacitor device was formed by sandwiching activated carbon (negative electrode) with S2 electrode (positive electrode) detached thru 1 M KOH electrolyte drenched permeable membrane. The electrochemical characterizations of device resulted an outstanding specific energy of 106 Wh/kg at 5 A/g, specific power of 24,000 W/kg at 30 A/g and reveals an excellent capacitance retentivity of 94% at room temperature after 2500 GCD cycles. This study suggested that 12 cycle numbers for deposition are optimized as an appropriate mass loaded for superior electrochemical energy storage applications.