Development status of supercapacitors and their widely applied organic semiconductors: Polythiophene conjugated polymers

The rapid development of energy storage systems has put forward higher requirements for the specific capacitance and stability of electrode materials. Conductive polymers with pseudocapacitance are very promising electrode materials due to their low cost, easy preparation, easy chemical modification, light weight, and good flexibility. However, supercapacitors based on conductive polymers still have disadvantages such as limited capacitance, low energy density, and low cycling stability. It is a promising way to blend conductive polymers with other materials to improve specific capacitance and stability. However, the preparation steps of multicomponent composites are relatively cumbersome, and preparation equipment are usually complex and costly. Therefore, it is necessary to design and synthesize conductive polymers with high specific capacitance. This review starts with the current development status of supercapacitors, focusing on the device structure, preparation methods, working principles, and important device parameters of polymer based pseudocapacitors; followed by the summary of development of supercapacitors based on thiophene based polymers.