In modern times, human lifestyle is heavily dependent on flexible electronic devices such as mobile phones, laptops, chargers, and electrical vehicles. One of the most pertinent requirements for these devices is an uninterruptible power supply. Currently, batteries and supercapacitors are the most widely used and researched electrochemical storage devices. Supercapacitors are preferred in applications that require rapid charge/discharge times. Other benefits of supercapacitors are their high-power density, extended durability, and environmentally friendly nature. As electronics devices used on a daily basis require lightweight and high-energy density energy storage systems, supercapacitors are preferred over batteries in these applications. Conventional supercapacitors suffer from the drawbacks of the requirement of an active electrode, the encapsulation requirement of the entire structure containing electrolyte and electrodes for prevention of leakage, and the rigid and bulky nature of the entire structure.

Supercapacitors with thinner and lighter technology incorporating flexible electrodes and electrolytic gel have been developed to overcome the above-mentioned drawbacks. High integrity improved electrochemical performance, and rational design are some of the considerations for forming modern flexible supercapacitors. In addition, high performing in terms of electrochemical performance and thin and flexible electrodes, which can be bent, rolled, or twisted depending on the application, are essential requirements for modern flexible supercapacitors. For rapid and stable ion kinetics, the electrolytic gels should be mechanically flexible and highly conductive for ion movement. Thus, the development of highly flexible and simple materials is required for energy storage systems.

Owing to the presence of large electrochemical sites, graphene, carbon nanotubes, and transition metal oxides have attracted significant interest from researchers. Owing to the presence of multiple atomic layers, 2D nanomaterials have attracted tremendous interest for the manufacture of supercapacitor electrodes. The higher active surface area, mechanical integrity owing to the stacked layer, and controllable electrical properties are other advantages of 2D nanomaterials. Owing to their layered structure, supercapacitors based on 2D nanomaterials exhibit a fast electrochemical performance and fast ion kinetics. In this chapter, the applications of supercapacitors in electrical technology (microgrids), their controllers, and developments in supercapacitor technology for the application of 2D nanomaterials in them are presented.