Development and evaluation of transition metal compound carbon based composites as electrodes for supercapacitor applications

Abstract

The design and development of environmentally conscious, viable, and sustainable energy newlinestorage devices with superior electrochemical characteristics has drawn a lot of interest newlinerecently as a solution to climate change and the rapidly diminishing conventional energy newlinesources supply. Supercapacitors are electrochemical energy storage systems that have a newlinelong lifespan, high charging-discharging rates, and excellent power and energy densities, newlinewhich will propel technological advancements. Supercapacitors have several advantages newlineover other energy-storing devices, including a large operating temperature range, low newlineweight, easy packaging, and inexpensive maintenance. newlineThe performances of supercapcitor devices are known to be primarily influenced by newlineelectrode materials, electrolytes, and separators. At present, improving the relatively newlinelow energy density and achieving commercialization have been deemed to be largely newlinedependent on the selection of suitable electrode materials. Transition metal compounds newlinehave been extensively documented to exhibit rich Faradic redox processes and high newlinetheoretical specific capacitance. Specifically, the intriguing characteristics of transition newlinemetal sulfides (TMS) of nickel, cobalt and bimetallic composites of nickel and cobalt has newlinebattery charge behaviour, enhanced electrical conductivity, high specific capacity, and newlinedesired electrochemical activity have drawn a lot of attention in ASCs. newlineAddition of multi-walled carbon nanotubes (MWCNTs) is a useful approach to increase newlinethe conductivity of electrode materials. Therefore, a combination of TMS and well-aligned newlineMWCNTs promote the intercalation and de-intercalation of ions on the surface of the newlineelectrode material, which increases electrode conductivity, improves chemical stability newlineand prevents aggregation. MWCNTs can be functionalized (f-MWCNT) by introducing newlinecarboxylic (-COOH) functional groups to change their surface energy properties, and can newlineincrease its chemical compatibility and reactivity. newlineIn the present research work, transition metal su