Influence of gas-diffusion-layer current collector on electrochemical performance of Ni(OH)₂ nanostructures

We report the electrochemical performance of Ni(OH)₂ on a gas diffusion layer (GDL). The Ni(OH)₂ working electrode was successfully prepared via a simple method, and its electrochemical performance in 1 M NaOH electrolyte was investigated. The electrochemical results showed that the Ni(OH)₂/GDL provided the maximum specific capacitance value (418.11 F·g⁻¹) at 1 A·g⁻¹. Furthermore, the Ni(OH)₂ electrode delivered a high specific energy of 17.25 Wh·kg⁻¹ at a specific power of 272.5 W·kg⁻¹ and retained about 81% of the capacitance after 1000 cycles of galvanostatic charge–discharge (GCD) measurements. The results of scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDS) revealed the occurrence of sodium deposition after long-time cycling, which caused the reduction in the specific capacitance. This study results suggest that the light-weight GDL, which can help overcome the problem of the oxide layer on metal–foam substrates, is a promising current collector to be used with Ni-based electroactive materials for energy storage applications.