Supercapacitors have shown great potential as a possible solution to the increasing global demand for next-generation energy storage systems. Charge repositioning is based on physical or chemical mechanisms. There are three types of supercapacitors-the electrochemical double layer, the pseudocapacitor, and a hybrid of both. Each type is further subdivided according to the material used. Herein, a detailed overview of the working mechanism as well as a new method for capacitance enhancement are presented.
Keywords: EDLC; Helmholtz model; electrical double layer capacitor; energy storage system; micropores; nanopores; negative capacitance; pseudocapacitor; supercapacitor; ultracapacitor.