Hierarchically porous carbon microfibers for solid-state supercapacitors

The architectures of sustainable carbon fibers are highly acquired from the perspective of supercapacitor (SC) applications, which has stimulated the exploration of advanced functional carbons for further enhancing the SC performance. Here, through integrating the strategies of ternary hybridization and chemical activation into one structure, hierarchically porous N-doped carbon microfiber sample (CPZ-AC), using a hybrid precursor of polyaniline (PANI) and ZIF-8 in situ grown on cotton thread, is rationally produced. It displays ideal capacitive properties especially with superior rate capability of 80% retention at a 100-fold rate. Moreover, the solid-state CPZ-AC//PVA/KOH (gel)//CPZ-AC SC achieves the highest power and energy densities of up to 4705.9 W kg−1 at 30 A g−1 and 5.2 Wh kg−1 at 0.5 A g−1, and decent cycling stability with 0.0015% capacitance decay per cycle within 10000 cycles at 4 A g−1. In addition, the device shows the applicability in portable electronics. This study may be extended to efficiently design ideal one-dimensional carbon materials promoting the blossom of carbon-based SCs.