Hydrogen-bond-mediated micelle aggregating self-assembly towards carbon nanofiber networks for high-energy and long-life zinc ion capacitors

Designing well-orchestrated carbon nanostructure is critical for Zn-ion capacitors with superb capacitive activity and durability. Herein, a hydrogen-bond-mediated micelle aggregating self-assembly strategy is developed to design interweaved carbon nanofiber networks (TB-DA-80) for propelling Zn-ion storage capability. In the strategy, the intermolecular hydrogen bonds between solvent molecules and hydrophilic segments of block copolymer (F127) is regulated by controlling temperature in polymerization, which could induce aggregating self-assembly of micelles. It has been revealed that hydrogen bonding is reduced by increasing temperature due to the enhancement of thermal motion of solvent molecular. The self-assembled micelles could guide the interweavement of carbon nanofiber networks, which maximize the accessibility of surface-active sites and stimulate ion migration throughout 3D architecture. Then, the assembled carbon nanofiber networks-based Zn-ion capacitor delivers an ultrahigh energy density of 163 Wh kg−1 and a super-stable cycle lifespan with a 90.5% capacity retention after 400, 000 cycles at 20 A/g. Systematic studies untangle that the excellent electrochemical metrics root in the synergy of physical Zn2+ and H+ dual-ion co-uptake and robust chemical redox of Zn2+ with carbonyl/pyridine motifs to form O − Zn − N bonds. This study provides a platform for the elaborate fabrication of nanoarchitectured carbon cathodes towards advanced energy storage.