In-situ growth of iron nanoparticles on porous carbon nanofibers for structural high-performance lithium metal anode

Abstract

Lithium metal anodes have attracted increasing attention in recent years. However, there are still significant challenges in the electrochemical cycle of lithium metals, including the growth of lithium dendrites, the formation of "dead lithium" layers, and unrestricted volume expansion. To solve these problems, using inexpensive acetylacetonate salt, polyacrylonitrile, and polymethyl methacrylate as raw materials, a 3D porous carbon nanofiber scaffold decorated with iron nanoparticles is reasonably designed by novel and unique in-situ growth method, without hazardous atmosphere, expensive catalyst deposition, and additional carbon sources. Notably, the obtained iron-doped 3D porous fibers can be used as lithium metal anode framework with low lithium deposition overpotential and long cycling stability under various current densities. The porous host structure can adapt to the inherent volume expansion and the transmission of lithium ions in the process of lithium plating/stripping, thereby improving the cycling stability. Density functional theory calculations indicate that carbon nanofibers decorated with Fe nanoparticles are more likely to absorb lithium atoms, resulting in more uniform lithium deposition. The present work provides a low-cost and scalable strategy for constructing 3D structural high-efficiency lithium metal anode, and opens new horizons for the research of lithium metal batteries and even other metal batteries.