Fabrication of transition metal selenides and their applications in energy storage

Electrochemical energy storage devices (lithium ion batteries, sodium ion batteries, magnesium ion batteries, and super capacitors) with high power and energy densities are considered the most promising equipment for large-scale applications of portable electronic devices and electric vehicles. These devices can be realized by exploring nanostructured materials with high capacity, favorable cycling stability, and superior rate capability. Transition metal selenides (TMSs) are potential materials for electrochemical energy storage systems. In this paper, we summarized the nanostructured transition metal selenides and indicated their properties, preparation methods, and applications in electrochemical energy storage systems. We discussed the electronic properties of TMSs and showed that these materials have tunable electronic properties. We enumerated the 10 most-used preparation methods of TMSs as well as their composites with other functional materials. Subsequently, we systematically reviewed their applications in lithium ion batteries, sodium ion batteries, magnesium ion batteries, and super capacitors. Finally, we proposed the challenges and opportunities of their applications in energy storage.