2D Microporous Polymers/Reduced Graphene Oxide with Built-In Lithiophilic Sites for Uniform Lithium Deposition in Lithium Metal Anode.

Lithium (Li) metal is an attractive anode material for use in high-energy lithium-sulfur and lithium-air batteries. However, its practical application is severely impeded by excessive dendrite growth, huge volume changes, and severe side reactions. Herein, a novel Li metal anode composed of lithiophilic two dimensional (2D) conjugated microporous polymer (Li-CMP) and reduced graphene oxide (rGO) sandwiches (Li-CMP@rGO) for Li metal batteries (LiMBs) is reported. In the Li-CMP@rGO anode, the conductive rGO facilitates the charge transfer while the functionalized-CMP provides Li nucleation sites within the micropores, thereby preventing dendrite growth. As a result, the Li-CMP@rGO anode can be cycled smoothly at 6 mA cm of current density with a platting capacity of 2 mAh cm for 1000 h. A Coulombic efficiency of 98.4% is achieved over 350 cycles with a low overpotential of 28 mV. In a full cell with LiFePO cathode, the Li-CMP@rGO anode also exhibited good cycling stability compared to CMP@rGO and CMP/Super-P. As expected, the simulation results reveal that Li-CMP@rGO has a strong affinity for Li ions compared to CMP@rGO. The strategies adopted in this work can open new avenues for designing hybrid porous host materials for developing safe and stable Li metal anodes.