Multi-Layer Graphene Mash Membrane Decorated with ZnO Rods for Controlling Dendritic Growth in Lithium Metal Anodes

Despite an ultimate capacity of ~3,860 mAh g⁻¹ and the lowest negative electrochemical potential (−3.040 V vs. the standard hydrogen electrode) of Li metal anode, it suffers from potential safety hazard and poor cycle lifetime by Li dendrite growth. Here we present a new design strategy for Li metal anode that can circumvent the issues regarding the unwanted Li dendrite growth by inducing position-selective and direction-selective deposition of Li. Deposition of Li is induced by disposing lithiophilic ZnO rods under lithiophobic multi-layer graphene. Owing to the geometric configuration, Li continues to grow in the opposite direction of the counter electrode, that is, toward the current collector. This unusual Li growth depresses the formation of dead Li and prevents a short circuit occurring between the anode and cathode. As a result, the proposed anode showed a significant improvement in cycling performance with no capacity loss over 1400 hours, superior rate characteristics with a Coulombic efficiency higher than 99.9%, and a low overpotential at high current density.