Great progress has been made in the development of cathode materials for Al-metal batteries. However, the in-depth study of Al anodes, especially the battery instability caused by Al dendrite growth, has not received much attention. In this work, we have identified the in-situ formation of Al dendrite growth, which is proved to bottleneck the practical use of Al-metal batteries. The dendrite formation severely affects battery performance, such as voltage and efficiency fluctuations, unstable cycling, etc. To further demonstrate the detailed growing process of dendrites, we make a comprehensive investigation into the interfacial chemistry of Al anode. We have found that the naturally formed Al₂O₃ surface film is dissolved in the ionic liquid electrolyte during Al plating, accompanied by the formation of solid-electrolyte interphase containing Al-Cl and Al-O like species on the anode surface before dendrite growth. To suppress this dendrite growth, we propose the use of porous Al, which provides a homogeneous ion flux and decreases the local current density. As a result, the porous anode maintains stable cycling over a wide range of current densities and areal capacities. The Al-graphite battery shows stable cycling up to 18000 times without capacity decay. This work suggests the significance of suppressing dendrite growth for the real applications and commercialization of Al-metal batteries and will draw attention to the battery design from the anode side.

在用于铝金属电池的阴极材料的开发方面已经取得了很大的进步。然而，对铝阳极的深入研究，特别是由铝枝晶生长引起的电池不稳定性，并未引起太多关注。在这项工作中，我们已经确定了铝枝晶生长的原位形成，这被证明限制了铝金属电池的实际使用。枝晶的形成严重影响电池性能，例如电压和效率波动，不稳定的循环等。为进一步说明枝晶的详细生长过程，我们对铝阳极的界面化学进行了全面研究。我们发现天然形成的Al ₂ O ₃在镀铝过程中，表面膜溶解在离子液体电解质中，伴随着在枝晶生长之前在阳极表面上形成包含Al-Cl和Al-O类物质的固体电解质中间相。为了抑制这种树枝状晶体的生长，我们建议使用多孔Al，它可以提供均匀的离子通量并降低局部电流密度。结果，多孔阳极在宽范围的电流密度和面积容量上保持稳定的循环。铝石墨电池显示出高达18000次的稳定循环，而容量没有衰减。这项工作表明了抑制枝晶生长对于铝金属电池的实际应用和商业化的重要性，并将引起人们对阳极设计的关注。