Electrochemical properties of spray deposited nickel oxide (NiO) thin films for energy storage systems

- Using economical spray Pyrolysis, NiO thin films were deposited on the FTO substrates at different temperatures for supercapacitor testing.
- From XRD results, cubic phase was observed for all deposition temperatures.
- Maximum energy density 8.93 Wh/Kg at current density 0.4 mA/cm2 was observed at 370 °C deposition temperature.
- The electrochemical impedance spectroscopy study showed that the diffusion coefficient enhanced with substrate temperature.

Nanostructured nickel oxide (NiO) thin films were deposited on fluorine doped tin oxide (FTO) substrates by inexpensive spray pyrolysis. The influence of substrate temperature on structural, morphological and electrochemical properties has been investigated. The structural and morphological analysis showed all NiO thin films were found to be similar to the thin film synthesized by conventional methods From the electrochemical results specific capacitance of NiO thin films increased between 16 to 88 F/g with the substrate temperature. The specific energy, specific power and coulomb efficiency are found to be 8.93 Wh/kg, 0.52 KW/ kg and 85.08%, respectively. Moreover, electrochemical impedance study showed higher conductivity and excellent Warburg impedance coefficient for NiO thin film deposited at 370 °C electrode materials.