Improved Electrochemical Performance of Ni2P2O7 and Mn‐doped Ni2P2O7 Electrode Materials for Supercapacitor Applications

Electrochemical analysis of Chemical bath deposited Ni₂P₂O₇ and Mn-Ni₂P₂O₇ thin films electrodes and theoretical studies reveals their charge storage behavior of Mn-Ni₂P₂O₇ film electrode offers higher supercapacitive performance than Ni₂P₂O₇ electrode. Trasatti and Dunn's model studies on these exhibit hybrid nature of the electrodes and the diffusive contribution is found dominant and thereby establishing pseudocapacitive nature.

Abstract

The development of electrode materials for supercapacitors is really progressive and it still poses a huge challenge for researchers in many aspects. Doping of transition metals is indeed effective method because fast interfacial charge transfer kinetics has demonstrated their potential supercapacitive nature. The present work submits the structural, morphological and electrochemical performances of nickel pyrophosphate (Ni₂P₂O₇) and manganese doped nickel pyrophosphate (Mn-Ni₂P₂O₇) thin film electrodes synthesized by chemical bath deposition method. The crystal structure of Ni₂P₂O₇ obtained through X-ray diffraction (XRD) is confirmed to be monoclinic which remains unaltered despite of Mn doping concentration. Morphological studies reveal that crystalline phase of Mn is intimately anchored on the surface of Ni₂P₂O₇ which is beneficial for better charge transfer between transition metal and transition metal phosphates. A specific capacitance value of 603 F/g is obtained for 3 M concentration of Mn doped Ni₂P₂O₇ from galvanostatic charge-discharge curve at current density 1 A/g. This value is noticeably higher than what is obtained for the pure Ni₂P₂O₇ indicating that Mn doping enhances the electrochemical performance of Ni₂P₂O₇ thin films.

Zum Volltext