Overcoming Passivation–Corrosion Dilemma of Al Current Collector for Aqueous Zn Battery

Al current collectors are widely adopted in nonaqueous batteries because of their low cost, high conductivity, and low density, yet their deployment in aqueous congeners (i.e., Zn-ion batteries) is largely precluded by concurrent issues of surface passivation and electrolyte-driven corrosion. Here, an on-site N-doped carbon-skinned Al current collector (NC@Al) is developed to resolve this longstanding dilemma. Enabled by an ultrafast Joule heating process, elevated temperature carbonization could be completed in seconds without thermally deforming the Al substrate, which renders a dense and continuous double-sided NC overlayer, affording favorable interfacial adhesion. Combined theoretical calculations and experimental diagnostics verify the NC overlayer simultaneously helps suppress the Al passivation-corrosion issue and promote uniform Zn deposition. As a result, symmetric cells based on NC@Al exhibit durable cycling beyond 3500 h at 0.5 mA cm^-2/0.25 mAh cm^-2. When paired with an iodine cathode, our constructed pouch cells with an active material loading of 25 mg cm^-2 sustain stable operation for 1000 cycles under a stringent N/P ratio of 1.77. Technoeconomic analysis further highlights the energy-efficiency advantage of our route in practical manufacturing. This work establishes a strategy for employing commercially available Al current collector materials toward aqueous batteries.