MXenes, two-dimensional compounds, owing to their similarity to graphene, were largely attracted in the electronic field in the form of energy storage and conversion. MXenes display maximum electrical conductivity, functionalized surface areas, and high mechanical stability. The unique morphology of MXenes instantaneously increases electrolyte ion transport and develops redox sites on the surface. This feature makes MXenes a promising candidate for high-performance electrodes. Proper blending of theoretical facts, along with experimental results of MXenes, will reform the supercapacitor technology by delivering high-energy-density products. This chapter aims to highlight the structural and chemical composition and applications of MXenes.