Emergence of melanin-inspired supercapacitors

Abstract In recent years, both natural melanin and their synthetic analogs have attracted increasing attention as an emerging class of bioinspired supercapacitor materials, due to their rich sources, excellent processability, and extraordinary electrochemical performances. Particularly, the inherent heteroatoms and catechol groups within natural melanin and polydopamine (PDA) nanomaterials can promote the total electrochemical activities and surface activation capabilities of the systems. This review strives to summarize the recent advances and highlights of melanin-inspired supercapacitors by focusing on their chemical structures, fabrication methods, working mechanisms as well as various applications ranging from wearable devices, flexible capacitors to supercapacitor separators. Finally, the current challenges of melanin-inspired supercapacitor systems, and future perspectives in the rational fabrication of the new generation of bioinspired supercapacitors are also closely discussed.