Aluminum (Al) is the most abundant metal element in earth crust, together with low cost and high safety. Al-ion batteries (AIBs) have been regarded as potential alternatives to lithium-ion batteries (LIBs) in large scale applications and attracted much attention in current days. In this review, recent developments of AIBs including the electrolyte exploration, electrode design and Al protection are summarized. Both aqueous and non-aqueous electrolytes exhibit important benefits for AIBs, especially ionic liquid electrolytes with high stripping/plating efficiency, which are preferentially discussed here. Furthermore, we highlight the design principles and electrochemical mechanism for carbons, metal compounds as well as new-type positive electrode materials for high-performance AIBs. Besides, we focus on the negative electrode protection with suitable coating layers to reduce dendrite formation and improve electrochemical activation of Al negative electrodes. The accessible characterization techniques that promote the development of AIBs are discussed. Finally, prospects and outlooks of AIBs towards theoretical investigations and practical applications are provided.

铝（Al）是地壳中含量最丰富的金属元素，具有低成本和高安全性。在大规模应用中，铝离子电池（AIB）被认为是锂离子电池（LIB）的潜在替代品，并在当今引起了很多关注。在这篇综述中，总结了AIB的最新发展，包括电解质探索，电极设计和铝保护。水性和非水性电解质都对AIB表现出重要的益处，尤其是具有高剥离/镀覆效率的离子液体电解质，在此优先讨论。此外，我们重点介绍了用于高性能AIB的碳，金属化合物以及新型正极材料的设计原理和电化学机理。除了，我们将重点放在具有合适涂层的负电极保护上，以减少枝晶的形成并改善Al负电极的电化学活化。讨论了促进AIB发展的可访问的表征技术。最后，提供了AIB在理论研究和实际应用中的前景和展望。