Advances of coconut waste as a sustainable energy storage solution—a comprehensive review

Exploiting natural renewable energy resources, especially from the biowaste agriproducts, is one of the hot topics in this era. In this context, coconut waste–derived activated carbon has received worldwide attention in various fields due to its availability, low cost, and complete utilization of waste raw material. Developing biocarbon from natural resources reduces the risk of environmental pollution and opens space for next-generation bio-compatible energy storage devices. In the field of supercapacitor technology, highly efficient, eco-friendly, and readily available electrode materials with high adsorption capacity and fast ion–electron movement are more desirable as potential candidates. In this way, coconut-based carbon derivates are fully encouraged. The current review mainly spotlights the recent advancements in producing activated carbon electrodes using coconut biomass residues for energy storage applications, including supercapacitors. In addition, various impact factors, including activation agent, carbonization conditions, and activation environment on surface area and porosity, thereby capacitive properties, are briefly explained. The current developments and challenges against the fully functional usage of biowastes and the solution for the existing technologies are also trying to be pointed out. It is anticipated that this study will give the reader a thorough understanding of the coconut biomass residues that can be used in energy storage applications and highlight some of the objectives and challenges that still need to be addressed.

Graphical abstract