Gallium-based nascent electrode materials towards promising supercapacitor applications: a review

To meet the energy requirement of the modern era, supercapacitors are promising candidates for energy storage devices, which possess the potential to compete with the future battery technology. To accomplish this pivotal task, it is vital to choose electrode materials that have high power and energy density as well as superb electrochemical stability. For the past few years, the use of gallium-based materials for energy storage applications has attracted attention because of their excellent activity towards electrochemical energy storage applications despite the single oxidation state (i.e., +3 which is redox inactive and does not contribute towards pseudo capacitance). Recently, research on gallium-based materials has started and will be continued further owing to the fact that gallium-based materials possess numerous excellent properties such as fast charge and discharge rate, high power density, long cycle life, stability over a wide range of temperatures, excellent electron velocity, superior chemical and physical stabilities and high voltage application capability, which make them a potential class of electrode materials for supercapacitors. The enhancement in the electrochemical performance upon the introduction of gallium into the system can make it a futuristic candidate for electrochemical energy storage devices. Herein, we systematically outline the synthesis and characterization of gallium-based materials and their composites as explored by esteemed researchers focusing only on their supercapacitive performance via electrochemical techniques. For a better understanding, the underlying charge storage mechanism and identified characteristics are presented to give a crystal-clear idea about the field. In addition, the key challenges and impending perspectives of gallium-based electrodes for supercapacitor applications are debated.