Regulating solvation and interface chemistry to inhibit corrosion of the aluminum anode in aluminum–air batteries

Abstract

As a promising energy storage technology, aluminum–air batteries possess the advantages of high energy density, safety and low-cost. However, the severe self-corrosion of the aluminum anode greatly limits their practical applications. To address such issues, solvation chemistry and interface chemistry are combined together to reduce the aluminum anode corrosion by adding a concentrated potassium acetate electrolyte component and sodium stannate electrolyte additive, which can greatly decrease the number of free H₂O molecules and improve the potential of hydrogen evolution. Thus, the aluminum anode exhibits significantly reduced corrosion rate behavior in the as-prepared electrolyte (0.085 mg cm⁻² min⁻¹ for the blank electrolyte, and 0.011 mg cm⁻² min⁻¹ for the hybrid high concentration electrolyte). The full cell with the optimized electrolyte shows a remarkably increased discharge capacity of 2439 mA h g⁻¹ at a current density of 25 mA cm⁻² and the cathode electrocatalyst is not damaged after discharging.