Mechanochemical growth of a porous ZnFe2O4 nano-flake thin film as an electrode for supercapacitor application

Herein, we are reporting a simple, economic, easy to handle, scalable and reproducible mechanochemical i.e. rotational chemical bath deposition (R-CBD) approach for the synthesis of well adhered nano-flake ZnFe2O4 thin films (NFs-ZnFe2O4) with uniform morphology on a stainless steel (SS) substrate, in comparison with nano-grain ZnFe2O4 thin films (NGs-ZnFe2O4) prepared using a conventional CBD approach. The influence of rotation on the evolution of the nano-flake morphology in NFs-ZnFe2O4 is also investigated. The porous NFs-ZnFe2O4 thin films demonstrated excellent pseudocapacitor properties with higher specific capacitance of 768 F g(-1) at high current density of 5 mA cm(-2), stability upto 5000 cycles (88% retention), higher energy density (106 W h kg(-1)) and power density (18 kW kg(-1)) compared to NGs-ZnFe2O4. The results were also found to be higher than those reported earlier for MFe2O4 based systems.