The diverse landscape of electrode materials in fiber-based supercapacitors: A review

Supercapacitors (SCs) are energy storage devices that have considerable potential to advance sustainable development. SCs offer rapid charge- discharge capabilities, impressive specific capacitance, reversibility, and extended operational lifespan. Electrode materials have a significant effect on the electrochemical behavior of SCs. Fiber-based SCs have attracted significant attention in recent years because of their promising application potential in flexible and wearable electronics. The performance of fiber-based supercapacitors is improved by using different types of electrodes, each with its own unique characteristics. Materials such as carbon, conductive polymers, and metal oxides make up these electrodes. Materials derived from carbon exhibit excellent electrochemical stability due to their large surface area and strong conductivity. Metal oxide demonstrates redox surface reactions and displays pseudo-capacitance behavior. Conductive polymer exhibits a high level of redox activity and may be readily produced on a fiber substrate. Hybrid electrode materials that combine carbonaceous and metal oxide/polymer components are known to improve energy storage performance. The requirements of flexibility as well as high energy and power density determine the choice of electrode materials in fiber-based SCs. Current research is focused on developing novel materials and fabrication techniques to further enhance the overall performance of SC devices. This paper summarizes the current state of the art and gives a brief history of the electrode materials utilized in SCs that are based on fiber. Different types of electrode materials are covered, including as carbon-based compounds, conducting polymers, and metal oxides. We present several research avenues to solve the issues associated with fiber-based electrode materials and identify the challenges themselves.