Carbon nanofibers surface-exposed with highly active Ag nanoparticles for enhanced interfacial dynamics of lithium metal anodes

Abstract

Lithium metal anodes (LMAs) are widely regarded as a crucial component for the next generation of high-energy-density lithium batteries. The extended pathways for lithium ion diffusion exacerbate concentration polarization, leading to dendrite growth in LMAs. Here, carbon nanofibers with surface-exposed high-activity silver nanoparticles (Ag@CNF) are achieved through the combination of electrospinning and ion exchange techniques, enhancing the interfacial dynamics during lithium storage. Compared to electrodes with encapsulated active sites, the self-supported and binder-free Ag@CNF significantly shortens lithium ion diffusion pathways, reduces nucleation overpotential, and promotes uniform ion diffusion and deposition. Furthermore, this unique structure induces a thinner solid electrolyte interphase (SEI) layer, and greatly reduces the apparent activation energy for charge transfer. Ag@CNF not only enhances atomic utilization efficiency of active centers but also optimizes performance in lithium metal batteries. Notably, assembled full cells demonstrate an excellent retention rate of 90% after 300 cycles at a high capacity of 1.5 mAh cm−2 and a low N/P ratio of 2.