Current Collector Material Selection for Supercapacitors

Abstract

The supercapacitor is a step-up device in the field of energy storage and has a lot of research and development scope in terms of design, its parts fabrication, and energy storage mechanism. The main function of the current collector is to collect and conduct electric current from electrodes to power sources. It also provides mechanical support to electrodes. To meet the required properties of the current collector materials should have minimum contact resistance, high electric conductivity, and good bonding capacity with electrodes. The bonding capacity can be increased by modifying the surface of the current collector, which is mainly carried out using industrial picoseconds laser device. Different types of materials are being used for the current collector, where the selection of materials depends upon the cost of materials and its suitability toward particular applications. Most commonly used conventional metals like copper (Cu), aluminum (Al), nickel (Ni), etc. are being replaced by advanced materials such as nanostructured or composite materials. In addition to this, the demand for flexible electronics is growing rapidly nowadays, and these devices require a material with enhanced properties. This review discusses various components of supercapacitors, i.e., electrode materials, electrolyte materials, separators, binders and current collectors, functions of current collectors, specifications of current collectors, various materials used as current collectors, various parameters that affect the performance of current collectors, i.e., thickness, temperature, electrolytes, etc., dimensions of current collectors, screening of current collectors using constraints, various governing equations used for electrical conductivity, thermal conductivity, tensile strength, mass, bending strength, etc., and various material indexes used to select the best materials using Ashby charts.