Anode/Cathode Dual-Purpose Aluminum Current Collectors for Aqueous Zinc-Ion Batteries

Rechargeable aqueous zinc (Zn)-ion batteries (RAZIBs), which use non-flammable aqueous electrolytes and low-cost electrode materials, show great potential to boost the development of safe, cost-effective, and highly efficient energy storage systems. The adoption of lightweight and inexpensive aluminum (Al) as current collectors seems to be a good vision, but Al exhibits an easily-corroded nature and a high impedance in aqueous electrolytes, making it a challenge to realize the utilization of Al current collector in RAZIBs. In this study, through the direct current magnetron sputtering, niobium (Nb) coated Al (Al-Nb) foils are prepared, which shows superior corrosion-resistance in an aqueous solution, while maintaining a satisfying electronic conductivity. Moreover, the Al-Nb foils can be adopted to both anode and cathode current collectors while exhibiting high coulombic efficiency and good cycling stability even when they are tested under a condition that can meet the real-world application demands, e.g., the Zn||Al-Nb half-cell shows an average coulombic efficiency of 99.17% in 320 cycles under a current density of 25 mA cm⁻² and a galvanizing capacity of 6.25 mAh cm⁻². The superior performance of the modified Al current collectors may mark a significant step toward the development of high-energy-density aqueous batteries.