Uniform Lithium Nucleation/Growth Induced by Lightweight Nitrogen-Doped Graphitic Carbon Foams for High-Performance Lithium Metal Anodes.

Abstract

The lithium metal anode has attracted soaring attention as an ideal battery anode. Unfortunately, nonuniform Li nucleation results in uncontrollable growth of dendritic Li, which incurs serious safety issues and poor electrochemical performance, hindering its practical applications. Herein, this study shows that uniform Li nucleation/growth can be induced by an ultralight 3D current collector consisting of in situ nitrogen-doped graphitic carbon foams (NGCFs) to realize suppressing dendritic Li growth at the nucleating stage. The N-containing functional groups guide homogenous growth of Li nucleus nanoparticles and the initial Li nucleus seed layer regulates the following well-distributed Li growth. Benefiting from such favorable Li growth behavior, superior electrochemical performance can be achieved as evidenced by the high Coulombic efficiency (≈99.6% for 300 cycles), large capacity (10 mA h cm-2 , 3140 mA h g-1NGCF-Li ), and ultralong lifespan (>1200 h) together with low overpotential (<25 mV at 3 mA cm-2 ); even under a high current density up to 10 mA cm-2 , it still displays low overpotential of 62 mV.