Review—The Synthesis and Characterization of Recent Two-Dimensional Materials for Energy Storage Applications

The ever-increasing energy consumption has been projected to burden renewable energy sources. It is imperative to look for high-performance clean energy storage systems to sustain future energy demands. Among all the environmentally friendly and efficient energy storage options, supercapacitors are one of the most researched devices. Supercapacitors possess excellent electrochemical properties such as high-power density, superior cyclic stability, fast charging-discharging rates, and high specific capacitance that makes them a fascinating candidate. To improve the energy storage capacity, the two-dimensional counterpart of the supercapacitors is being investigated extensively and manifested unique electrochemical properties. This article thoroughly summarizes the synthesis and characterization techniques adopted for the most recent two-dimensional supercapacitor electrode materials. We focus on the family of carbon-based materials, transition metal oxides and hydroxides, MXenes, and transition metal dichalcogenides that can be employed for clean energy storage applications. The performance of these materials is discussed and compared based on their synthesis technique.