Sodium-ion capacitors (SICs) have attracted widespread attention due to their combination of high-energy batteries and high-power supercapacitors as well as low cost of sodium resources. However, the anodes exhibit low specific capacities and sluggish kinetics, thus limiting fast development of high-performance SICs. In the present work, the sulfur and nitrogen dual-doped carbon nanofiber (S-NCNF) membrane was synthesized as a novel anode material of SICs. Introduction of S atoms can result in an enlarged interlayer distance of 0.38 nm in S-NCNF, which is beneficial to Na⁺ ion insertion and the electron transport. As a result, the obtained S-NCNF electrode shows high sodium-storage capacity (298 mAh g⁻¹ at 0.1 A g⁻¹) and superior rate capability (188 mAh g⁻¹ at 5 A g⁻¹). The fabricated SIC delivers high energy density (97 Wh kg⁻¹) and power density (17 kW kg⁻¹) as well as long cycle life (3000 cycles).

钠离子电容器（SIC）由于结合了高能电池和高功率超级电容器以及钠资源的低成本而受到广泛关注。然而，阳极表现出低的比容量和缓慢的动力学，因此限制了高性能SIC的快速发展。在本工作中，合成了硫氮双掺杂碳纳米纤维（S-NCNF）膜作为新型的SIC阳极材料。引入S原子可导致S-NCNF中的层间距离增大0.38 nm，这有利于Na ⁺离子插入和电子传输。结果，获得的S-NCNF电极显示出高的钠存储容量（在0.1A g ^-1时为298mAh g ^-1）和优异的倍率能力（188mAh g）。^-1在5 A g ^-1）。所制造的SIC提供高能量密度（97 Wh kg ^-1）和功率密度（17 kW kg ^-1）以及长循环寿命（3000个循环）。