Progress on aqueous rechargeable aluminium metal batteries

Abstract

Aqueous rechargeable aluminium metal batteries (ARAMBs) have advantages of high energy density, cost efficiency and reasonable safety. However, parasitic reactions between the Al anode and electrolyte, sluggish dynamics and low reversibility of the Al anode, and structural instability caused by the high charge density of Al³⁺ ions lead to a short cycling life and inferior high-rate performance in ARAMBs. Herein, in this review, we summarize the research progress on ARAMBs by emphasizing the reported strategies to address the above-mentioned intractable issues. Initially, we discuss how to regulate the Al anode and interphase to accelerate the kinetics of Al stripping, which mainly includes strategies of ionic liquid analogue-derived solid electrolyte interphases (SEIs), artificial interfacial functional layer and aluminium alloy. Subsequently, the electrolyte modification approaches are highlighted including preparing highly concentrated single-salt/bi-salt electrolytes and designing electrolyte additives to reduce the parasitic reactions of ARAMBs. Finally, we introduce the progress on fabricating cathodes, such as vanadium-based materials, manganese-oxide materials, molybdenum-based materials, Prussian blue analogues, carbon materials, and organic materials to accommodate Al³⁺ ions. We propose that the further development of ARAMBs requires the cooperation of the above-mentioned strategies to improve their overall electrochemical performance and the development of new methods to illustrate the reaction mechanism of batteries.