Zinc Deposition Tuned by Single-Layer Graphene on Copper

Using carbon as a substrate or scaffold has been considered as an efficient strategy to improve the uniformity of zinc deposition, which may boost the anode performance of metal zinc batteries. However, the essential role of the carbon substrate remains unclear. Here, single-layer graphene grown on copper is used as a model material to investigate the interaction between zinc and carbon. The morphology and crystallinity of early-stage zinc deposition with galvanostatic or potentiostatic electrochemical plating are discussed. By using an electrochemical quartz crystal microbalance study, we verify the difference in energy dissipation of the zinc deposition with or without single-layer graphene. Density functional theory simulations show that the presence of graphene reduces the difference in the binding energy of zinc on different sites of defective copper surfaces, thus improving the uniformity of zinc electrodeposition. Our study shows that single-layer graphene can act as the passivation layer of copper to reduce the probability of dendrite growth.