The use of free‐standing carbon‐based hybrids plays a crucial role to help fulfil ever‐increasing energy storage demands, but is greatly hindered by the limited number of active sites for fast charge adsorption/desorption processes. Herein, an efficient strategy is demonstrated for making defect‐rich bismuth sulfides in combination with surface nitrogen‐doped carbon nanofibers (dr‐Bi₂S₃/S‐NCNF) as flexible free‐standing electrodes for asymmetric supercapacitors. The dr‐Bi₂S₃/S‐NCNF composite exhibits superior electrochemical performances with an enhanced specific capacitance of 466 F g⁻¹ at a discharge current density of 1 A g⁻¹. The high performance of dr‐Bi₂S₃/S‐NCNF electrodes originates from its hierarchical structure of nitrogen‐doped carbon nanofibers with well‐anchored defect‐rich bismuth sulfides nanostructures. As modeled by density functional theory calculation, the dr‐Bi₂S₃/S‐NCNF electrodes exhibit a reduced OH⁻ adsorption energy of ‐3.15 eV, compared with that (–3.06 eV) of defect‐free bismuth sulfides/surface nitrogen‐doped carbon nanofiber (df‐Bi₂S₃/S‐NCNF). An asymmetric supercapacitor is further fabricated by utilizing dr‐Bi₂S₃/S‐NCNF hybrid as the negative electrode and S‐NCNF as the positive electrode. This composite exhibits a high energy density of 22.2 Wh kg⁻¹ at a power density of 677.3 W kg⁻¹. This work demonstrates a feasible strategy to construct advanced metal sulfide‐based free‐standing electrodes by incorporating defect‐rich structures using surface engineering principles.

中文翻译：

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缺硫硫化铋/掺氮碳纳米纤维作为不对称超级电容器的高级自由电极

使用独立式碳基杂化物在满足不断增长的能量存储需求方面起着至关重要的作用，但是由于快速电荷吸附/解吸过程的活性位点数量有限，极大地阻碍了该方法的应用。本文证明了一种有效的策略，可将富缺陷的硫化铋与表面掺杂氮的碳纳米纤维（dr-Bi ₂ S ₃ / S-NCNF）结合起来用作不对称超级电容器的柔性自立式电极。对DR-Bi系₂小号₃ / S-NCNF复合物表现出优异的电化学性能的466 F G增强的比电容^-1在1A g的放电电流密度^-1。Dr‐Bi _2的高性能S ₃ / S-NCNF电极源自其掺氮的碳纳米纤维的层级结构，并具有固定良好的缺陷丰富的硫化铋纳米结构。如建模的密度泛函理论计算中，DR-Bi系₂小号₃ / S-NCNF电极显示出降低的OH ^-吸附能-3.15电子伏特，与（-3.06 eV）的铋的硫化物的无缺陷/表面含氮的相比掺杂的碳纳米纤维（df-Bi ₂ S ₃ / S-NCNF）。通过使用dr-Bi ₂ S ₃ / S-NCNF混合电池作为负极，并使用S-NCNF作为正极，进一步制造了不对称超级电容器。该复合材料显示出22.2 Wh kg的高能量密度^-1的功率密度为677.3 W kg ^-1。这项工作展示了一种利用表面工程原理通过结合富含缺陷的结构来构造先进的基于金属硫化物的自立式电极的可行策略。