Porous zinc cobaltite (ZnCo2O4) film by successive ionic layer adsorption and reaction towards solid-state symmetric supercapacitive device.

One-step, simple and inexpensive successive ionic layer adsorption and reaction (SILAR) method has been used to synthesize porous network of zinc cobaltite (ZnCo2O4) in 2D form on stainless steel (SS) substrate. Porous structure of ZnCo2O4 electrode enables electrochemical specific capacitance of 675Fg(-1) at 5mVs(-1) sweep rate with high rate capability and cycling performance of 69% over 2000 cycles. Furthermore, fabricated ZnCo2O4 solid-state supercapacitor cell in symmetric mode using PVA-KOH gel electrolyte exhibited a specific capacitance of 69.65Fg(-1) with specific energy of 9.67Whkg(-1) and specific power of 1.45kWkg(-1) at a current density of 1.07Ag(-1). The results clearly demonstrate the facile method for the synthesis of porous network of ZnCo2O4 and make them promising electrode material for energy storage application.