A Review on Recent Developments in Polyindole–Based Nanocomposite Electrode Materials for Supercapacitor Applications

Abstract

Polyindole (PIn) has attracted considerable attention as a promising conducting polymer for energy storage devices despite its low electrical conductivity. This interest is attributed to several appealing features, including high redox activity, excellent thermal stability, a low tendency for degradation, and strong compatibility with other components. As a result, PIn-based hybrid composites that include metal oxides, metal–organic frameworks, Mxenes, chalcogenides, and/or carbon materials have been notably recognized as promising electrode materials for supercapacitor applications. This review highlights recent advancements in expanding PIn-based nanocomposite electrode materials for supercapacitor applications. Significant efforts have been made to develop new binary and ternary PIn-based nanocomposites in recent years to utilize the beneficial electrochemical properties of the composite's components. Several new methods have been implemented for the synthesis of novel PIn–based composites for electrode fabrication to utilize the untapped docility of PIn, high electrical conductivity of carbon allotropes, and wider charging/discharging potential range of metal oxides. The present review has adequately compiled and briefly discussed the scattered literature published during 2018–2024 on recently developed PIn–based electrode materials used in supercapacitor applications. This review aims to assist in developing novel electrode materials with enhanced electrochemical properties for supercapacitors.