Application of nickel foam in electrochemical systems : a review

Abstract

The effectiveness of electrochemical systems in various applications (e.g., energy storage and conversion, wastewater treatment, ammonia synthesis) is, in essence, dependent on the electrode materials employed in such systems. The emphasis of research on electrochemical systems is given to developing electrode materials that would offer cost-effectiveness, stability, and reliable results that can be practical for commercial scaling. However, the operation of these systems also relies on other various components that include electrode fabrication, electrolytes, system architecture, the durability of the systems, and supporting components (i.e., substrate/current collector). On the choice of the current collector, nickel foam (NF) has enjoyed widespread attention as a favourable substrate in various electrochemical systems. This growing trend is attributed to its unique interlinked three-dimensional structure that offers advantages such as light weight, high porosity, great mechanical strength, chemical stability, and promising electrical and thermal conductivity. These traits are favourable for maximized contact areas between the current collector, the active materials, and charged species, resulting in the reduction of charge transport pathways, which is a vital step for improving the electrochemical performance. This review aims at highlighting the use of NF as a substrate of choice in developing effective electrodes for various electrochemical systems and can serve as a navigational tool for the literature involving the use of NF as the current collector. It also shows, to a certain extent, the impact of NF on electrochemical performance as compared with other current collectors.