A high-energy sodium-ion capacitor enabled by a nitrogen/sulfur co-doped hollow carbon nanofiber anode and an activated carbon cathode

摘要: Nonaqueous Na-ion capacitors (NICs) have been recently regarded as potential sustainable power devices due to their high specific energy/power and the abundant distribution of sodium resources on Earth. However, performance current NICs is usually restricted by kinetics imbalance between deintercalation/intercalation in anode surface ion adsorption/desorption cathode. Herein, we demonstrate superior sodium-ion storage properties nitrogen/sulfur co-doped hierarchical hollow carbon nanofibers (N/S-HCNFs) for application an ideal material NICs. The N/S-HCNFs are fabricated through situ gas sulfuration a polyaniline nanofiber precursor, which obtained with aid citric acid templates. Benefiting from positive synergistic effects both N S co-doping one-dimensional structure, sodium-storage half-cell versus Na/Na+ exhibits capacity (∼447 mA h g−1 at 50 g−1), excellent rate capability (∼185 10 A outstanding cycling stability (no decay after 3000 cycles 5 among best performances carbonaceous Na-storage anodes. Furthermore, dual-carbon NIC device constructed activated (AC) cathode, it has large energy density 116.4 W kg−1, 20 kW kg−1 (at 48.2 kg−1) long cycle life cycles, most reported AC-based