N-doped carbon/Si nanoparticles composite film modified Ni foam skeleton for dendrite-free and long-life lithium metal anodes

Lithium metal anodes are an ideal candidate material for high energy density lithium-ion batteries. However, the uncontrollable growth of lithium dendrites and infinite volume expansion are a big challenge for the commercialization of lithium metal anodes. In order to realize dendrite-free lithium metal anodes, we prepared N-doped carbon/Si nanoparticles composite film modified Ni foam (NFSC) via a simple impregnation-calcination method as a three-dimensional (3D) lithiophilic skeleton for lithium metal anodes. NFSC has several advantages, including a 3D porous conductive structure, a large specific surface area, uniformly distributed abundant lithiophilic nitrogen-containing functional groups and Si nanoparticles providing abundant lithium nucleation sites. This reduces nucleation overpotential, facilitates uniform lithium deposition, suppresses the growth of lithium dendrites, and significantly improves the cycling stability of lithium metal anodes. As a result, NFSC exhibits low nucleation overpotential and the Li||NFSC half-cell maintains a high Coulombic efficiency (CE) of 99.15 % after 1000 cycles at 1 mA cm-- 2 and 1 mAh cm- 2 . Moreover, the NFSC in a symmetric cell exhibits low polarization voltage of 18 mV together with an ultra-long cycling life of over 2000 h at 1 mA cm-- 2 and 1 mAh cm-- 2 . Furthermore, the full cell assembled with LiFePO4 4 and NFSC@Li demonstrates superior rate performance and excellent long-term cycling stability. The long-term cycling stability exceeds 2500 cycles at 0.5C, far surpassing that of LiFePO4||Li 4 ||Li full cell (600 cycles). This work provides a simple and effective approach to achieve dendrite- free lithium metal anodes.