Decoding Interfacial Evolution of Aluminum Anode and Constructing Multifunctional Layers toward Ultra-Long Cycle Stability

Understanding the dynamic evolution of the aluminum anode interface in ionic liquid electrolytes is crucial for the large-scale application of rechargeable aluminum batteries (RABs). Herein, we use a series of advanced in situ characterizations to reveal a dendrite-to-corrosion transition, demonstrating that imidazolium cations (EMI⁺) fundamentally dominate anode degradation and instability. Therefore, based on a differential access mechanism, we engineer a metal-organic framework (MOF-C) layer with molecular-scale nanochannels that selectively block corrosive EMI + while accelerating AlCl₄⁻ diffusion. The modified Al/MOF-C anode achieves an unprecedented cycling stability of >11,000 h (at 1 mA cm⁻² with minimal 20 mV overpotential) in symmetric cells, far exceeding all previous reports (typically <2000 h). Matched with natural graphite cathodes, full cells retain 95% capacity over 500 cycles. This work not only resolves the long-standing interfacial dispute in RABs but also establishes an ingenious solution aligned with interfacial evolution for next-generation stable metal anodes.