Electrochemical capacitors: Technical challenges and prognosis for future markets

Electrochemical capacitors are potential devices that could help bringing about major advances in future energy storage. They are lightweight and their manufacture and disposal has no detrimental effects on the environment. A comprehensive description of fundamental science of electrochemical capacitors is presented. Similarities and differences between electrochemical capacitors and secondary batteries for electrical energy storage are highlighted and various types of electrochemical capacitors are discussed with special reference to lead–carbon hybrid ultracapacitors. Some envisaged applications of electrochemical capacitors are described along with the technical challenges and prognosis for future markets.

► Basic principles of capacitors are presented.
► Various applications of supercapacitors and technical challenges are discussed.
► Recent developments on lead–carbon hybrid ultracapacitors are discussed.
► A prognosis of future market for supercapacitors is presented.