Nitrogen-doped porous carbon nanofiber decorated with FeNi alloy for dendrite-free high-performance lithium metal anode

Abstract

Lithium metal has garnered increasing attention, and is considered to be the most promising anode material for the next-generation rechargeable batteries with higher energy density such as lithium-sulfur, lithium-air and solid-state batteries. However, several serious challenges limit the commercial application of lithium metal batteries, including uncontrolled lithium dendrite growth, inherent volume expansion, and low Coulombic efficiency. Here, a nitrogen-doped porous nanofiber scaffold decorated with FeNi alloy nanoparticles with high lithophilicity is proposed by the electrospinning technique. The porous structure and the doping of FeNi alloy can expose more lithium nucleation active sites, and effectively reduce the nucleation overpotential of lithium metal to guide the uniform deposition of lithium. The porous structure formed by the sublimation of polymethyl methacrylate can effectively relieve the volume expansion and structural stress during the cycling process. As a result, excellent cycle stability and outstanding rate performance are observed in the tests of symmetric cells, highlighting the feasibility of the designed bimetallic doped carbon fiber scaffold for developing high-performance lithium metal anodes. The present work provides new strategies to solve the formation of lithium dendrites and brings new inspiration for the design and construction of high-efficiency lithium anodes and other secondary batteries anodes.