Electrode/electrolyte interface adjustment through adding mannitol into the solution to improve the re-discharge performance of alkaline Al-air batteries

Abstract

As a high-power battery system, Al-air batteries exhibit a wide range of potential applications. However, Al-air batteries are susceptible to significant open-circuit corrosion of the aluminum electrodes when removed from the electrolyte during standby, resulting in the formation of a dense film of corrosion products on the aluminum electrode surface. This, in turn, impedes the re-discharge performance of Al-air batteries. Based on an electrode/electrolyte interface adjustment strategy, mannitol is used as the additive to be added into 4 M KOH solution to improve re-discharge performance. Experimental analyses and theoretical calculations reveal that the inclusion of mannitol enhances the re-discharge performance of Al-air batteries through a combination of hydrogen bonding and adsorption. Importantly, it is noted that mannitol has minimal impact on the battery power density. The reason for the improvement is explained reasonably by a proposed mechanism. These findings offer valuable insights for the development of Al-air batteries with high performance.