Strategically designing layered two-dimensional SnS2-based hybrid electrodes: A futuristic option for low-cost supercapacitors

Supercapacitors are promising energy storage devices in current century due to their high specific capacitance, cyclic stability, high power density, and high voltage rating. Due to their excellent electrochemical properties, supercapacitors are invariably used in a multitude of applications ranging from portable electronics to electric vehicles. The electrochemical performance of a supercapacitor mainly depends on the type of electrode-active material used in it. Thereby a careful selection is mandatory to achieve the excellency. Nanostructured electrode-active materials such as carbon nanomaterials, transition metal oxides, transition metal dichalcogenides (TMDs), electronically conducting polymers, etc. are invariably used for supercapacitor application. Among these, TMDs have received great interest, particularly transition metal disulfides such as molybdenum disulfide, tin disulfide (SnS2), etc. Tin is abundant on the earth with excellent charge storage capabilities, attracted great scientific interest for application as electrode materials in supercapacitors. Good electronic conductivity, long cycling life and low-cost are its added advantages. Herein, we discuss the recent trends in layered two-dimensional (2D) SnS2-based electrodes to develop low-cost supercapacitors. Initially, their crystal structure, basic properties, synthesis methods are discussed. Further, strategically designing electrode nanostructures to achieve excellent electrochemical performance is reviewed then after. This includes material design in terms of morphology, pore-size, and shape as well as preparation of 2D SnS2-based nanocomposite electrodes. Furthermore, the challenges and future perspectives of 2D SnS2-based supercapacitors are included.