Ultrathin Protection Layer via Rapid Sputtering Strategy for Stable Aqueous Zinc Ion Batteries

Abstract Surface side reactions and time‐consuming modification methods hinder the practical application of zinc‐ion batteries. This study introduces an ultrathin protection layer for the Zn anode via a rapid sputtering method. The dopants on the CN10@Zn anode create surface dipoles and local variations in charge distribution, facilitating zinc ion migration to pyrrolic nitrogen dopant sites with reduced adsorption barriers. Additionally, hydroxyl oxygen dopants enhance the hydrophilicity of the sputtering layer, forming a strong adhesion with the zinc anode and improving ion accessibility. This results in dense nucleation sites for uniform zinc deposition. Consequently, the sputtered layer achieves a Coulombic efficiency of 99.8% over 2,700 cycles in Cu||Zn cells and a lifespan of up to 2,100 h in zinc symmetric cells. When paired with Na 0.65 Mn 2 O 4 cathodes, the sputtered layer retains 89% capacity over 1,000 cycles at 1 A g −1 . This study presents a promising method for rapidly fabricating ultrathin electrode materials.