Bio-Nanotechnology in High-Performance Supercapacitors

The use of bio-nanotechnology for the fabrication of diverse functional nanomaterials with precisely controlled morphologies and microstructures is attracting considerable attention due to its sustainability and renewability. As one of the key energy storage devices, supercapacitor (SC) requires the active electrode material to have high specific surface area, interconnected porous structure, excellent electronic conductivity, and appropriate heteroatom doping for promoting the transfer of electrons and electrolyte ions. The combination of bio-technology and SC will open up a new avenue for the large-scale fabrication of high performance functional energy storage devices. In this review, the most state-of-the-art research progress in bio-nanotechnological fabrication of different nanomaterials, including carbon materials, metal oxides, conducting polymers, and their corresponding composites are reviewed with the following three bio-nanotechnical approaches covered: (1) biomass carbonization technologies; (2) bio-template methods; and (3) bio-complex technologies, while also highlighting their applications as functional SC electrodes.