Spatially uniform Li deposition realized by 3D continuous duct-like graphene host for high energy density Li metal anode

Li metal is the essential anode material for high-energy-density batteries due to its low electrochemical potential and high specific capacity (3860 mAh g(-1)). Unfortunately, the uneven plating/stripping of Li metal causes uncontrolled Li dendrites growth, which induces low cycling efficiency and safety concerns. Herein, we report a 3D graphene framework with continuous duct-like structure (3DCG) as a stable host for Li metal anode. The lithium plating behavior on 3DCG was investigated through ex-situ and in-situ techniques. The duct-like graphene provides the pathway accelerating the Li+ diffusion and promotes homogeneous metallic Li deposition throughout the 3D framework. The continuously porous structure of 3DCG electrode provides a space for the metallic Li deposition and could effectually adjust the volume expansion during cycles. As a result, the 3DCG electrode exhibits a high average Coulombic efficiency of 98.7% over 1000 h, an extremely high capacity (up to 20 mAh cm(-2), 3236 mAh g(-1)), and a stable Li plating/stripping performance even at a high current density of 10 mA cm(-2). Meanwhile, the full batteries coupled with sulfur cathodes show excellent cycling stability. This work presents the approach to realize the uniform Li deposition throughout the 3D framework and long-lifespan lithium metal batteries. (C) 2020 Elsevier Ltd. All rights reserved.