N‐Doped Graphene Modified 3D Porous Cu Current Collector toward Microscale Homogeneous Li Deposition for Li Metal Anodes

Abstract

AbstractLithium metal is the most promising anode material for high‐energy‐density batteries due to its high specific capacity of 3860 mAh g−1 and low reduction potential of −3.04 V versus standard hydrogen electrode. However, huge volume change, safety concerns, and low efficiency impede the practical applications of Li metal anodes. Herein, it is shown that the nitrogen‐doped graphene modified 3D porous Cu (3DCu@NG) current collector can mitigate the above problems. The N‐doped graphene, coating on the surface of 3D current collector, not only contributes to a uniform Li+ flux, but also leads to a scattered distribution of electrons throughout the surface, finally contributing to a uniform Li deposition and the improved electrochemical performance. In addition, the continuously porous structure of 3DCu@NG provides a space for the metallic Li deposition and could effectually accommodate the volume expansion during cycling. As a result, the Li‐3DCu@NG anode exhibits a high areal capacity of 4 mAh cm−2, a high Li utilization of ≈98%, and an ultralow voltage hysteresis of ≈19 mV. The multifunctional N‐doped graphene modified 3D porous current collector promisingly provides a strategy for safe and high‐energy lithium metal anodes.