Tailoring the electrochemical performance of monoclinic Ni2P2O7 microstructure across different alkaline electrolytes

Abstract

The impact of varying electrolytic solutions on the electrochemical performance of electrode substances is significant. Consequently, this research investigates the effects of different electrolytes on the performance of nickel pyrophosphate (Ni2P2O7) electrodes in the context of supercapacitor applications. Nickel pyrophosphate electrodes were synthesized on nickel foam (NF) substrates using a facile, scalable chemical bath deposition (CBD) technique. The Ni2P2O7 material characterized different physico-chemical comprehensive characterization. Electrochemical assessments of Ni2P2O7/NF electrode were conducted in 2 M solutions of KOH, NaOH, and LiOH. Notably, in a 2 M KOH milieu, Ni2P2O7 exhibited a superior specific capacity of 156.3 mAh/g at 50 mA/cm2, alongside a cyclic retention rate of 71.6% after 5000th CV cycles. Additionally, it demonstrated enhanced energy (31.26 Wh/kg) and power densities (699 W/kg). Moreover, a Ni2P2O7/NF-based symmetrical solid-state energy storage device revealed a specific capacitance of 163.53 F/g, with energy and power densities of 7.25 Wh/kg and 125 W/kg, respectively, at a current density of 2 mA/cm2. This study highlighted the need to choose an appropriate electrolyte based on the electrode material. © 2024 Hydrogen Energy Publications LLC