Fiber‐shaped rechargeable batteries hold promise as the next‐generation energy storage devices for wearable electronics. However, their application is severely hindered by the difficulty in fabrication of robust fiber‐like electrodes with promising electrochemical performance. Herein, yolk–shell NiS₂ nanoparticles embedded in porous carbon fibers (NiS₂⊂PCF) are successfully fabricated and developed as high‐performance fiber electrodes for sodium storage. Benefiting from the robust embedded structure, 3D porous and conductive carbon network, and yolk–shell NiS₂ nanoparticles, the as‐prepared NiS₂⊂PCF fiber electrode achieves a high reversible capacity of about 679 mA h g⁻¹ at 0.1 C, outstanding rate capability (245 mA h g⁻¹ at 10 C), and ultrastable cycle performance with 76% capacity retention over 5000 cycles at 5 C. Notably, a flexible fiber‐shaped sodium battery is assembled, and high reversible capacity is kept at different bending states. This work offers a new electrode‐design paradigm toward novel carbon fiber electrodes embedded with transition metal oxides/sulfides/phosphides for application in flexible energy storage devices.

中文翻译：

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卵黄壳NiS2纳米颗粒嵌入式碳纤维，用于柔性纤维状钠电池

纤维状可充电电池有望成为可穿戴电子设备的下一代储能设备。但是，由于难以制造具有令人满意的电化学性能的坚固纤维状电极，因此严重阻碍了它们的应用。在此，成功地制造并开发了嵌入多孔碳纤维（NiS ₂ PCF）中的卵黄壳NiS ₂纳米颗粒，并将其开发为用于钠存储的高性能纤维电极。从健壮嵌入式结构，三维多孔和导电碳网络，和蛋黄-壳的NiS受益_2个纳米颗粒，所制备的NiS ₂ ⊂PCF纤维电极达到约679毫安Hg的高可逆容量^-1在0.1 C下，出色的速率能力（10 C下为245 mA hg ^-1），超稳定的循环性能，在5 C下5000次循环中可保持76％的容量。值得注意的是，组装了柔性纤维状钠电池，并具有高可逆容量保持在不同的弯曲状态。这项工作为新型碳纤维电极提供了一种电极设计范例，该新型碳纤维电极嵌入了过渡金属氧化物/硫化物/磷化物，可用于柔性储能设备。