Recently, the promising electrochemical energy devices have made great progress in developing the state-of-the-art electrode materials, improving the efficiency of electron transfer, and lessening the energy barrier of electrocatalytic reactions. The two-dimensional (2D) materials possess excellent electric and heat conductivity, strong mechanical strength, ultra-high carrier mobility, and large specific surface area, which facilitate effective active sites for catalytic reactions. They can also form network structures with larger active surface area and open pore architectures through stacking, enhancing mass adsorption and transfer on the surface.

This chapter overviews graphene-like 2D transition metal dichalcogenides (TMDs) in electrochemical energy applications in terms of the fundamental characterizations including electronic structures and intrinsic properties, the assortments of their synthetic methods and various applications in supercapacitors, lithium-ion batteries, and electrocatalytic reactions. The challenges and future perspectives facing TMDs are featured on the basis of its current development.