Commercial Cr2O3 as protective coating for aqueous zinc-ion battery anodes

Rechargeable aqueous zinc-ion batteries (AZIBs) are promising candidates for large-scale energy storage owing to their safety and cost efficiency. To overcome industrialization challenges such as dendrite growth and hydrogen evolution, interface engineering has emerged as an effective strategy. Herein, a facile scraper-coating method using commercial Cr 2 O 3 powder is employed to construct a protective anode layer. The porous Cr 2 O 3 coating provides abundant Zn 2+ diffusion pathways and adsorption sites, optimizing nucleation kinetics and lowering the energy barrier. This facilitates relatively uniform zinc deposition, effectively suppressing dendrite formation and corrosion. Consequently, the Cr 2 O 3 @Zn-100 ǁ Cu asymmetric battery delivers nearly 100% coulomb efficiency over 2000 cycles at 5 mA cm −2 , while the symmetric battery exhibits over 2800 h of stable cycling at 0.5 mA cm −2 . This cost-effective, extensible method significantly enhances cycling durability and offers a practical pathway toward the commercial implementation of AZIBs.