Interface Engineering of Spatial Confinement‐Induced Ion‐Channel for Stabilizing Rechargeable Aluminum Batteries

Abstract Aluminum metal anodes remain a major bottleneck for the practical implementation of rechargeable aluminum batteries due to the uncontrolled dendrite growth and interfacial side reactions that severely limit battery lifespan. To overcome these intractable issues, a novel diatomite‐based artificial interfacial layer (DE/C) is designed that leverages spatial confinement to construct selective ion channels. These channels regulate Al deposition by guiding the directional ion flux and stabilizing interfacial chemistry. Furthermore, aluminumophilic Si─OH groups in channels reduce the desolvation energy barrier, as well as promote the Al deposition kinetics. Additionally, the DE/C layer exposes Al (111) crystal planes, thereby not only facilitating uniform Al 3+ deposition, but also mitigating side reactions. As a result, the DE/C@Al symmetrical cell achieves an impressive lifespan of over 10 500 h at 0.1 mA cm −2 . When paired with a natural graphite (NG) cathode, the full cell exhibits superior cycling stability, retaining 85 % of its initial capacity after 5000 cycles at 1 A g −1 . Meanwhile, the pouch cell has a remarkable capacity retention of 98.8% after 400 cycles at 500 mA g −1 , verifying the practical viability for large‐scale application. This work provides valuable insights toward the practical development of high‐performance rechargeable aluminum batteries.