Recent trends in transition metal diselenides (XSe2: X = Ni, Mn, Co) and their composites for high energy faradic supercapacitors

Transition metal diselenides (TMDSs) are one of the promising materials in electrochemical energy storage systems because of their super hydrophilicity, honeycomb array, and multistructural resilience make TMDSs and their composites ideal for a variety of applications. TMDSs and their composites have high supercapacitor storage capacities and hold a unique position in supercapacitor research. However, the low electrical conductivity, poor cycle stability, and low rate performance, on the other hand, severely restrict their uses for large-scale applications. This review offers a thorough introduction to TMDSs and their composites, as well as an overview of current research developments. The most popular TMDS preparation processes have been presented, and their link to structural electrochemical performance will be examined in depth. Another topic covered in the viewpoint is TMDS-based composites, which help to improve the overall performance of supercapacitors, particularly in terms of energy density and cycle stability. The most pressing scientific issues and prospects for producing efficient and stable TMDS-based electrodes for high-energy supercapacitor applications are discussed.