Carbon Nanopatch‐Decorated Defect‐Rich Regions for Stable Zinc Metal Anodes

Uncontrolled dendrite growth and parasitic side reactions at defect‐rich regions severely limit the cycling stability of aqueous Zn‐ion batteries (AZIBs). Here, we propose a simple, carbon‐nanopatch strategy based on candle‐flame pyrolysis for stabilizing Zn anodes. After rinsing, the introduced carbon nanoparticles are mainly retained in microscopic defect‐rich regions, forming localized carbon nanopatches (CNPs) on the Zn surface. Experimental characterization and theoretical analysis suggest that these localized CNPs can help alleviate local electric‐field intensification, promote more uniform current‐density and interfacial Zn 2+ distribution, and reduce direct electrolyte exposure at defect‐rich regions. In addition, flame treatment may promote grain growth within the Zn foil, which can further improve interfacial stability. As a result, Zn@CNPs symmetric cells achieve cycling lifetimes of 3450 h at 1 mA cm −2 /1 mAh cm −2 and 3500 h at 5 mA cm −2 /1 mAh cm −2 . When paired with a β‐MnO 2 cathode, the full cell retains 74% of its capacity after 1000 cycles at 1 A g −1 , compared with 28% for the cell using Bare Zn. This work provides a simple and cost‐effective strategy for developing more stable aqueous Zn‐based batteries.