Biowaste-based Porous Carbon for Supercapacitors: Synthesis, Fabrication and Electrochemical Performances: A Review

The development of low-cost, high-efficiency electrode materials for supercapacitors is motivated by the growing need for green and affordable clean energy (SDG goal 7). Developing new energy conversion and storage technologies, such as supercapacitors, batteries, and fuel cells, is a viable option for meeting energy demands while addressing environmental concerns. Recent advances in carbonaceous materials derived from biowaste for supercapacitor applications have piqued the interest of academics and industry alike. Because of their large surface area and porous structure, activated carbon-based electrode materials can be used in various applications, including supercapacitors, fuel cells, and batteries. Carbonaceous materials such as carbon nanotubes, graphene, and activated carbon, exhibit EDLC-like behavior mainly due to ion adsorption at the electrode interface. In recent years, several potential strategies for the synthesis and structural architecture of biowaste-derived porous carbons have been tested with varying degrees of success. Thus, it is critical to evaluate the prospects for biowaste-derived porous carbon materials used as supercapacitor electrodes. In this review, we highlight how different biowaste-derived porous carbons affect the surface properties of carbon nanostructures and how this phenomenon affects their electrochemical performance. Additionally, the extent to which various biowastes have been utilized as porous carbon for supercapacitor electrodes is addressed. The different synthesis techniques, such as hydrothermal carbonization, physical activation, chemical activation, and microwave-assisted activation, are briefly described in this review. Finally, we highlight fabrication techniques as well as electrochemical performance measurements such as CV, GCD, EIS, energy density, and power density.