Resolving cross-scale contradictions in fast-charging zinc anode interfaces for practical applications

Fast-charging aqueous zinc-ion batteries (AZIBs) have advanced rapidly owing to their intrinsic safety, low cost and the longer Sand's time of divalent Zn²⁺, which can delay ion-depletion-limited failure compared with monovalent Li⁺. Nevertheless, the divalent nature also imposes sluggish desolvation and interfacial charge-transfer kinetics, making fast zinc deposition highly susceptible to polarization, dendrite growth, parasitic reactions, and rapid capacity decay. Existing reviews mainly classify materials and strategies, whereas the field lacks a scale-resolved framework explaining where fast-charging failure originates, how it propagates and when it becomes irreversible. Here we propose a polarization-driven “three contradictions” framework for AZIBs, in which microscopic ion-electron transport mismatch generates polarization, mesoscale kinetics-uniformity conflict amplifies nonuniform deposition, and macroscopic electrochemical stability window (ESW)-limited rate-capacity trade-off converts accumulated overpotential into capacity loss and full-cell failure. By mapping desolvation design, foil/powder electrode engineering and wide-window electrolyte strategies onto these three stages, we further propose practical evaluation protocols based on DOD_Zn, cumulative plating capacity (CPC), E/C ratio, N/P ratio and full-cell validation, providing a roadmap from high-rate laboratory demonstrations toward application of AZIBs under XFC conditions.