Development of low-carbon energy storage material: Electrochemical behavior and discharge properties of iron-bearing Al–Li-based alloys as Al–air battery anodes

Abstract

With inevitable introduction of Fe in aluminum processing, a method for achieving high-value utilization of iron-bearing aluminum-based alloys is essential. Aluminum–air batteries are among the most promising power sources and have attracted the attention of researchers. In this study, the electrochemical behavior and discharge properties of Al–0.5Fe and Al–0.5Mn–0.5Fe–0.1Sn–xLi (x = 0, 1, 2, and 3 wt %) alloys as Al–air battery anodes are investigated in 4 M NaOH. Using x-ray diffraction (XRD) and scanning electron microscopy (SEM), the constituents and distributions of the main phases are discussed. Alloying improves electrochemical behavior and discharge properties of Al–0.5Fe. The static and dynamic electrochemical experiments indicate that Al–0.5Mn–0.5Fe–0.1Sn–2Li exhibits the best corrosion resistance. The discharge performances of the five alloys show that the average voltages decrease with increasing current density and Li content. Based on the electrochemical and discharge results, Al–0.5Mn–0.5Fe–0.1Sn–2Li is an excellent candidate for use in Al–air battery anodes, reaching a peak anodic efficiency of 77.86% at a relatively high current density of 80 mA cm−2, with a power density and specific energy of 83.60 mW cm−2 and 1618.06 mW h g−1, respectively. The optimal discharge performance is attributed to dispersed AlLi particles and the fragmentation effect of AlLi on the long strip-like Al6Mn(Fe) phase.