Effect of Fe dopant concentration on electrochemical properties of Ni2P2O7 thin films

Schematic diagram of the synthesis of FNP thin films by chemical bath deposition technique. [Display omitted] •Fe doped Ni2P2O7 thin film (FNP) prepared by chemical bath deposition is promising candidate for supercapacitor applications.•Fe dopant concentration in Ni2P2O7 has noticeable influence on electrochemical properties.•FNP3 thin film electrode offers a maximum specific capacitance of 492 F/g at with 96% capacitance retention. Transition metal phosphates have attracted great attention in energy storage applications because of their good ionic conductivity, enriched redox action and high specific capacitance. Fe doped Ni2P2O7 thin films (FNP) successfully prepared by following chemical bath deposition technique which is facile and reproducible one. The thin film characterization such as structural, morphological, compositional and electrochemical studies of Fe doped FNP with dopant concentration 0.5 M, 0.10 M and 0.15 M express effects in respective properties leading to selection of promising electrode material for supercapacitor applications. Impurity free Fe doped FNP films, all belonging to monoclinic system with agglomerated microspheres in morphology exhibit noticeable specific capacitance. 0.15 M Fe doped Ni2P2O7 thin film (FNP3) shows profound effect on electrochemical properties delivering a specific capacitance of 492 F/g at low current density with 13.12 Wh/kg energy density (ED) at 0.17 kW/kg power density (PD) in the present work. Stability tests on FNP3 shows excellent capacitance retention of 96% after 2000 cycles which is a prerequisite for supercapacitors.