Designing PEDOT-based hybrid electrodes for supercapacitors by electrospinning strategy

Poly (3,4-ethylenedioxythiophene) (PEDOT) is an electronically conducting polymer synthesized from its monomer, 3,4-ethylenedioxylthiophene (EDOT). It is a conjugated polymer with polythiophene and carries positive charges. High electronic conductivity and oxidation stability of PEDOT attracted the attention for electrochemical energy storage devices such as supercapacitors. One-dimensional (1D) nanostructures such as nanofibers are highly recommended to achieve high specific capacitance when used as electrode-active materials in supercapacitors. This is due to the possession of large surface area to volume ratio of 1D nanostructures which enable enhanced interactions of electrolyte-ions with the electrode thereby the charge property gets enhanced. Among the various electronically conducting polymers, PEDOT fibers have attracted great scientific interest for supercapacitor electrode application due to their unique characteristics such as large surface area, good electronic conductivity, good redox activity, high flexibility, etc. to name a few. Electrospinning is an effective method to synthesize PEDOT micro/nano-fibers in a cost-effective and simple route. A detailed review on the electrospun synthesis of PEDOT micro/nanofibers-based hybrid electrodes for supercapacitor electrode application is lacking in the literature. This motivated us to write a comprehensive review on the said topic. In this review, we focus the synthesis and characterization of PEDOT micro/nanofibers via electrospinning method. Further, we discuss the preparation of hybrid electrodes based on the electrospun PEDOT micro/nanofibers with other electrochemically-active materials. Furthermore, we review the supercapacitor performance evaluation of the PEDOT micro/nanofibers-based hybrid electrodes as well as supercapacitor devices. This review proclaims the development of novel hierarchical PEDOT micro/nanofibers-based hybrid electrodes for next-generation high-performance supercapacitors that find applications in wearable electronics and electric vehicles. A detailed review which explains the features of PEDOT-based supercapacitor electrodes fabricated especially by electrospinning strategy is lacking in the literature. This motivated us to write a comprehensive review on the synthesis of PEDOT, characterizations and performance evaluations of PEDOT-based supercapacitors by emphasizing the fundamental aspects of preparing flexible electrodes for application in flexible supercapacitors.