Dermis-Inspired Ni ₃ S ₂ –Modified Bamboo-Based Sandwich-Structured Flexible Electrodes

To meet the stringent demands for high specific capacitance in biomass-based flexible electrodes, inspired by skin structure, this work designed and prepared novel sandwich-structured flexible electrodes (SSFE). Nickel sulfide-modified bamboo fiber membranes (Ni 3 S 2 /BFM) form the surface layer, while a dual-network flexible conductive adhesive (CA), composed of a highly flexible polysiloxane matrix and reinforced with polypyrrole-coated bamboo fiber (PPy@BF), serves as the core layer. The Ni/Ni 3 S 2 support network and the dual-network conductive adhesive, composed of polydimethylsiloxane (PSi) and Cu/PPy@BF, ensure efficient electronic transport. The SSFE exhibits excellent electrochemical performance; the areal capacitance reaches 6760 mF·cm –2 . This biomimetic sandwich-structured flexible design enhances the mechanical strength of bamboo fiber-based electrodes and shortens electron transport pathways, which provides valuable guidance for developing high-performance biomass-based flexible electrodes.