Abstract 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.

中文翻译：

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用于高能量密度锂金属负极的 3D 连续管状石墨烯基质实现空间均匀的锂沉积

摘要 锂金属具有低电化学势和高比容量（3860 mAh g-1），是高能量密度电池必不可少的负极材料。不幸的是，锂金属的不均匀电镀/剥离会导致不受控制的锂枝晶生长，从而导致低循环效率和安全问题。在此，我们报告了一种具有连续管状结构（3DCG）的 3D 石墨烯框架作为锂金属负极的稳定宿主。通过非原位和原位技术研究了 3DCG 上的锂电镀行为。管状石墨烯提供了加速 Li+ 扩散的途径，并促进了整个 3D 框架中金属锂的均匀沉积。3DCG电极的连续多孔结构为金属锂的沉积提供了空间，可以有效地调节循环过程中的体积膨胀。因此，3DCG 电极在 1000 小时内表现出高达 98.7% 的高平均库仑效率、极高的容量（高达 20 mAh cm-2、3236 mAh g-1）和稳定的锂电镀/剥离性能，即使在10 mA cm-2 的高电流密度。同时，全电池与硫正极结合显示出优异的循环稳定性。这项工作提出了在整个 3D 框架和长寿命锂金属电池中实现均匀锂沉积的方法。