Sodium-ion supercapacitors (SICs) have attracted increasing scientific attention for mid-to-large-scale energy storage applications due to their high energy and power densities. Herein, an ultra-flexible and free-standing hybrid anode material consisting of sulfur-doped Nb₂O₅ quantum dots (~3 nm) uniformly embedded within nitrogen and sulfur co-doped microporous carbon nanofiber (S–Nb₂O₅@NS-PCNF) is successfully fabricated by electrospinning followed by a sulfidation treatment. The designed 3D microporous network not only offers a continuous conducting framework for electron-transport, but also provides more accessible channels for rapid Na-ions migration. Furthermore, the S-doping induced anionic oxidation of Nb₂O₅ (O^2-2−→O⁻) and S-doping in microporous carbon nanofibers result in the formation of numerous oxygen vacancies and defects for enhanced electrical conductivity and surface pseudocapacitance. In particular, the oxygen vacancies induced by the S-doping on Nb₂O₅ have been firstly demonstrated. This S–Nb₂O₅@NS-PCNF film electrode exhibits superior rate capability (124 mAh g⁻¹ at 4 A g⁻¹) and ultralong cycling life (173 mAh g⁻¹ after 10000 cycles at 2 A g⁻¹). The SIC full-cell comprising a S–Nb₂O₅@NS-PCNF anode and an activated carbon cathode delivers a maximum energy density of 112 Wh kg⁻¹ at 80 W kg⁻¹ and a ultralong-term cycling stability. This strategy provides a promising application for highly efficient energy storage systems.

钠离子超级电容器（SIC）由于具有高能量和功率密度，因此在中大型储能应用中吸引了越来越多的科学关注。在这里，一种超柔和自立的混合阳极材料，由均匀掺杂在氮和硫共掺杂微孔碳纳米纤维（S–Nb ₂ O ₅ @NS ）中的掺硫Nb ₂ O ₅量子点（〜3 nm）组成-PCNF）是通过电纺丝然后进行硫化处理成功制造的。设计的3D微孔网络不仅为电子传输提供了连续的传导框架，而且还为Na离子的快速迁移提供了更多可访问的通道。此外，S掺杂引起Nb _2的阴离子氧化ø ₅（O ^{2- 2-} →O; ^- ）和S-掺杂在微孔碳纳米纤维导致大量氧空位和增强的导电性和表面缺陷赝的形成。特别地，首先证明了由S掺杂在Nb ₂ O ₅上引起的氧空位。此S-的Nb ₂ ö ₅ @ NS-PCNF膜电极表现出优良的速率能力（124毫安克^-1在4 A G ^-1）和超长循环寿命（173毫安克^-1以2A克万次循环后^-1） 。SIC全电池包含S–Nb ₂ O ₅@ NS-PCNF阳极和活性炭阴极在80 W kg ^-1时提供112 Wh kg ^-1的最大能量密度，并具有超长期循环稳定性。该策略为高效的能量存储系统提供了有希望的应用。