Dramatic capacity fading and poor rate performance are two main obstacles that severely hamper the widespread application of the Si anode owing to its large volume variation during cycling and low intrinsic electrical conductivity. To mitigate these issues, free-standing N-doped porous carbon nanofibers sheathed pumpkin-like Si/C composites (Si/C-ZIF-8/CNFs) are designed and synthesized by electrospinning and carbonization methods, which present greatly enhanced electrochemical properties for lithium-ion battery anodes. This particular structure alleviates the volume variation, promotes the formation of stable solid electrolyte interphase (SEI) film, and improves the electrical conductivity. As a result, the as-obtained free-standing Si/C-ZIF-8/CNFs electrode delivers a high reversible capacity of 945.5 mA h g⁻¹ at 0.2 A g⁻¹ with a capacity retention of 64% for 150 cycles, and exhibits a reversible capacity of 538.6 mA h g⁻¹ at 0.5 A g⁻¹ over 500 cycles. Moreover, the full cell composed of a free-standing Si/C-ZIF-8/CNFs anode and commercial LiNi_1/3Co_1/3Mn_1/3O₂ (NCM) cathode shows a capacity of 63.4 mA h g⁻¹ after 100 cycles at 0.2 C, which corresponds to a capacity retention of 60%. This rational design could provide a new path for the development of high-performance Si-based anodes.

剧烈的容量衰减和差的速率性能是两个主要障碍，这严重阻碍了硅阳极的广泛应用，这是由于硅阳极在循环过程中的体积变化大且固有电导率低。为了缓解这些问题，通过电纺丝和碳化方法设计和合成了独立的N掺杂多孔碳纳米纤维包覆的南瓜状Si / C复合材料（Si / C-ZIF-8 / CNFs），从而大大增强了电化学性能。锂离子电池负极。这种特殊的结构减轻了体积变化，促进了稳定的固体电解质相间（SEI）膜的形成，并提高了电导率。结果，获得的自立式Si / C-ZIF-8 / CNFs电极可提供945.5 mA h g ^-1的高可逆容量在0.2 A g ^-1下，在150个循环中的容量保持率为64％，并且在500个循环中，在0.5 A g ^-1下表现出538.6 mA h g ^-1的可逆容量。此外，由独立式Si / C-ZIF-8 / CNFs阳极和商用LiNi _1/3 Co _1/3 Mn _1/3 O ₂（NCM）阴极组成的完整电池的容量为63.4 mA h g ^-1在0.2 C下100次循环后，对应的容量保持率为60％。这种合理的设计可以为高性能硅基阳极的开发提供一条新途径。