Cobalt compounds as supercapacitor electrode materials

Supercapacitors are very important kind of electrochemical energy storage devices. It differs from those of batteries and exhibit high power density. The energy storage in supercapacitors is influenced by many parameters like nature of electrode material, current collector, electrolyte etc. among which most crucial is the morphology of the electrode. Based on the type of energy storage mechanism supercapacitors are divided as Electrochemical Double Layer Capacitors and Pseudocapacitors. There is a practice to have both kind of these materials as electrode materials to achieve high electrochemical performance. Typically metal oxides and hydroxides of transition metals show high capacitances due to their variable oxidation states. In this regard, cobalt compounds have been focused a lot. This makes most of the research works are targeting designing cobalt based compounds adopting new routes of synthesis, modifying the regular methods so on. Herein we discuss the fundamentals of supercapacitors, their design and approaches to obtain high performance electrode materials using differently synthesized cobalt related compounds.