A High Voltage Aqueous Zinc-Vanadium Redox Flow Battery with Bimodal Tin and Copper Clusters by a Continuous-Flow...

Aqueous zinc-based redox flow batteries are promising large-scale energy storage applications due to their low cost, high safety, and environmental friendliness. However, the zinc dendritic growth has depressed the cycle performance, stability, and efficiency, hindering the commercialization of the zinc-based redox flow batteries. We fabricate the carbon felt modified with bimodal sized tin and copper clusters (SCCF) with the electrometallic synthesis in a continuous-flow cell. The SCCF electrode provides a larger zinc nucleation area and lower overpotential than pristine carbon felt, which is ascribed to the well-controlled interfacial interaction of bimodal tin and copper particle clusters by suppressing unwanted alloy formation. The zinc symmetric flow battery and the zinc-based hybrid redox flow battery show the improved zinc plating and stripping efficiency. The SCCF electrode exhibits 75% improved cycling stability compared to the pristine carbon felt electrode in the zinc symmetric flow battery. Notably, the high-voltage aqueous zinc-vanadium redox flow battery demonstrates a high average cell voltage of 2.31 V at 40 mA cm^-2, showing a Coulombic efficiency of 99.9% and an energy efficiency of 87.6% for 100 cycles. We introduce a facile strategy to suppress the zinc dendritic growth, enhancing the performance of the zinc-based redox flow batteries.