A Historical Review of Electrode Materials and Electrolytes for Electrochemical Double Layer Supercapacitors and Pseudocapacitors

The supercapacitor is one of the most promising alternatives to other popular energy storage solutions, viz., rechargeable batteries and capacitors. They are considered the bridge between batteries (high energy density) and capacitors (high power density) because of their fast charge/discharge capacity, high specific power/energy, and good service-life, which make them the most promising candidate for future energy storage/redistribution systems as well as hybrid electric vehicles. In the past, much progress has occurred in electrode materials, electrode architecture, electrolytes, separators, and device configuration. This review article discusse the basics of electrochemical super capacitors, storage principal, device configuration, electrode materials, and electrolytes, including the coverage of the comprehensive literature account of the advancements in the area; and, finally, the discussion on technological challenges in the development of commercially viable next-gen supercapacitor devices.