Rechargeable aluminum (Al) metal batteries (RAMBs) are considered as one of the most attractive alternatives to the existing battery technologies because of their low cost, high safety, high abundance of Al (the most earth-abundant metal element, over 3 700 times that of lithium), and the well-established Al industry. Furthermore, Al anode has a high theoretical gravimetric capacity of 2 981 mA·h··g⁻¹ and the highest theoretical volumetric capacity of 8056 mA·h·cm⁻³, as well as a relatively low redox potential of −1.66 V versus the standard hydrogen electrode, thus enabling RAMBs to have a potentially high energy density. The importance of reversible Al plating and stripping is particularly pronounced for RAMBs. However, it is still non-trivial to achieve high Al plating/stripping reversibility and superior lifespan, regardless of whether in aqueous, ionic liquid (IL) or organic electrolytes. Therefore, the reversibility and development of Al anodes await a breakthrough in addressing significant challenges, i.e., passivation, corrosion, and dendritic growth. Unfortunately, there is still a lack of systematic discussions on the strategies for achieving highly reversible and long-life Al anodes.This review discusses some challenges facing Al anodes in current electrolyte systems, analyzes failure mechanisms, and presents some advanced solutions. Specifically, in aqueous electrolytes, the passivation of Al by the formation of a thin yet dense Al₂O₃ layer on the Al surface hinders reversible stripping and plating. Moreover, the thermodynamic instability of Al in aqueous electrolytes induces and exacerbates the corrosion and hydrogen evolution side reactions during resting and cycling. To solve these problems, the structural optimization of Al anode and the development of high-performance modification layers can effectively alleviate side reactions and enhance cycling stability. Also, regulating electrolyte components and concentrations can facilitate the formation of a more efficient solid electrolyte interphase (SEI), thus preventing the performance degradation caused by hydrogen evolution and dendrite growth. Room-temperature ILs with high concentrations of AlCl₃ salt can promote reversible Al plating and stripping under ambient conditions. However, their notorious corrosion nature causes continuous consumption of Al, and exacerbates the uneven nucleation and growth during deposition, thus resulting in Al dendrites. In addition to conventional strategies (i.e., anode structure modification, host design, and interfacial coating), Al alloying and control of preferential crystal orientation are proved as effective approaches to enhance the corrosion resistance of Al and reduce nucleation barriers. These approaches promote uniform deposition and mitigate dendrite growth. The incorporation of functional additives, such as leveling agents, into the electrolyte also offers an effective approach. These additives stabilize Al morphology and suppress corrosion. In the case of organic electrolytes, the high-volumetric-charge density and intense electron-withdrawing nature of Al³⁺ result in slow de-solvation kinetics and severe interface passivation, which represent major bottlenecks for Al anodes. To address these challenges, the introduction of chloride ions into organic electrolytes can enhance the reversibility of Al. Chloride ions partially disrupt the passivation layer and, more importantly, facilitate the formation of Al₂Cl₇⁻ active anions, thereby improving the de-solvation kinetics of Al³⁺ in organic electrolytes.Summary and ProspectsRAMBs are regarded as one of the most promising alternatives to the existing battery technologies for large-scale energy storage due to their low cost, high capacity, superior safety, and abundant availability of aluminum. However, RAMBs still encounter significant challenges, with the lack of highly reversible, long-lifetime Al anodes being a critical bottleneck. Although considerable progress has been made in this field, it remains in its early stages and requires further comprehensive investigation. A future research can focus on the following aspects, 1) Revealing the in-depth failure mechanisms and enhancing the stability of Al metal anodes. Whether through anode modification or electrolyte optimization, the underlying mechanisms must be thoroughly investigated, with particular attention to the failure processes and stability of the anode interface. In-situ characterization techniques are highly preferred to identify the fundamental causes of interface failure. Also, there is a need to refine some methods for evaluating anode stability and to establish standardized performance parameters and evaluation criteria. 2) Exploring high-performance, non-corrosive, and cost-effective RAMBs systems. The performance of RAMBs is highly depended on the properties of the electrolyte and its compatibility with Al anodes. To address the corrosion challenges posed by chloride-based ILs on both Al and other metallic parts, the design of non-corrosive electrolytes is essential for practical applications. However, employing such non-corrosive electrolytes necessitates overcoming an issue of natural Al₂O₃ passivation layer on Al anode. 3) Developing high-capacity and stable cathode materials. The extremely high charge density of Al³⁺ results in an intense Coulomb interaction with intercalation-type cathode materials, which slows down the intercalation/deintercalation kinetics of Al³⁺ and leads to an irreversible structural damage to the cathode. For conventional conversion-type cathodes, their intense bonding with Al³⁺ severely limits the reversibility of redox reactions. It is thus critical for advancing RAMBs to develop novel cathode materials that can efficiently utilize the three-electron-transfer mechanism of Al³⁺ and exhibit fast kinetics.In this review, we emphasize the critical importance of the fundamental failure mechanisms of Al anodes and clarify Al³⁺ solvation and de-solvation behaviors and breakthroughs in the design of pivotal materials such as non-corrosive and high-performance electrolytes and high-capacity cathodes. This review provides valuable insights for the development of next-generation RAMBs and contributes to accelerating their practical application.