Mesoporous Graphene Hosts for Dendrite-Free Lithium Metal Anode in Working Rechargeable Batteries

Lithium (Li) metal anode has received extensive attentions due to its ultrahigh theoretical capacity and the most negative electrode potential. However, dendrite growth severely impedes the practical applications of the Li metal anode in rechargeable batteries. In this contribution, a mesoporous graphene with a high specific surface area was synthesized to host the Li metal anode. The mesoporous graphene host (MGH) has a high specific surface area (2090 m²/g), which affords free space and an interconnected conductive pathway for Li plating and stripping, thus alleviating the volume variation and reducing the generation of dead Li during repeated cycles. More importantly, the high specific surface area of MGH efficiently reduces the local current density of the electrode, which favors a uniform Li nucleation and plating behavior, rendering a dendrite-free deposition morphology at a low overpotential. These factors synergistically boost the Li utilization (90.1% vs. 70.1% for Cu foil) and life span (150 cycles vs. 100 cycles for Cu foil) with a low polarization of MGH electrode at an ultrahigh current of 15.0 mA/cm². The as-prepared MGH can provide fresh insights into the electrode design of the Li metal anode operating at high rates.