Nahm Yeon Woo, Lee Jae Seob, Choi Jae Hun, Cho Jung Sang, Kang Yun Chan
Department of Materials Science and Engineering, Korea University, Anam-Dong, Seongbuk-Gu, Seoul, 136-713, Republic of Korea.
Department of Engineering Chemistry, Chungbuk National University, Cheongju, Chungbuk, 28644, Republic of Korea.
Small. 2025 Jul;21(30):e2504223. doi: 10.1002/smll.202504223. Epub 2025 May 27.
3D host materials are promising for Li-metal anodes (LMAs) because of their adaptability to volume changes and large areas that prevent current localization, hindering dendritic Li formation. Herein, freestanding porous N-doped carbon nanofibers (PCNFs) with uniformly distributed SiO are synthesized by electrospinning and subsequent carbonization. In these composites, tunnel-like, open channels are formed between the CNFs by removing polystyrene (PS) and the hollow N-doped nanocages (HNC) generated from zeolitic imidazolate frameworks-8 (ZIF-8) during carbonization, providing sufficient space for Li deposition. Accompanying these structural advantages, the adequate electron conductivity and lithophilic properties derived from the conductive N-doped CNFs and insulating SiO confer optimized characteristics for uniform Li distribution. The coulombic efficiency exceeds 98% over 160 cycles in asymmetrical cells at a current density of 2.0 mA cm, with stable voltage hysteresis and an average overpotential of 25 mV for 1350 h in symmetrical tests. Full cells assembled with composite anodes predeposited with Li exhibited excellent capacity retention, delivering 141 mAh g at 2.0 C with LiNiCoMnO (NCM622) cathodes. The results highlight that the optimized combination of conductive CNFs, HNCs, and insulating SiO effectively enables uniform Li deposition, significantly enhancing cycling stability and Coulombic efficiency (CE) of LMAs.
三维主体材料因其对体积变化的适应性以及能够防止电流局部化的大面积特性，对锂金属阳极（LMA）具有很大潜力，可阻碍锂枝晶的形成。在此，通过静电纺丝和后续碳化合成了具有均匀分布SiO的独立式多孔氮掺杂碳纳米纤维（PCNF）。在这些复合材料中，在碳化过程中通过去除聚苯乙烯（PS）以及由沸石咪唑酯骨架-8（ZIF-8）生成的中空氮掺杂纳米笼（HNC），在碳纳米纤维之间形成了隧道状的开放通道，为锂沉积提供了足够的空间。伴随着这些结构优势，由导电氮掺杂碳纳米纤维和绝缘SiO衍生出的足够的电子导电性和亲锂性能赋予了锂均匀分布的优化特性。在不对称电池中，电流密度为2.0 mA cm时，160次循环的库仑效率超过98%，在对称测试中，电压滞后稳定，1350小时内平均过电位为25 mV。用预沉积锂的复合阳极组装的全电池表现出优异的容量保持率，在2.0 C下与LiNiCoMnO（NCM622）阴极配合时，放电比容量为141 mAh g。结果表明，导电碳纳米纤维、HNC和绝缘SiO的优化组合有效地实现了锂的均匀沉积，显著提高了LMA的循环稳定性和库仑效率（CE）。
