Bioinspired Oxygen‑Enriched Nanodiamonds as Electrolytic Erythrocyte Mimics for Dendrite‑Free Zinc‑Ion Batteries

The implementation of aqueous zinc‑ion batteries (AZIBs) for large‑scale grid storage is thwarted by dendrite formation driven by concentration polarization. Drawing inspiration from the oxygen transport physiology of erythrocytes, oxygen‑enriched nanodiamonds (OND) are conceptualized as dynamic “electrolyte erythrocyte mimics” that enable intelligent Zn 2+ shuttling under an applied electric field. These dynamic mediators operate through a reversible surface charge reversal mechanism: negatively charged OND initially adsorb Zn 2+ at the anode, acquiring a positive zeta‑potential, then migrate cathode‐ward to release Zn 2+ while regenerating their negative surface charge, completing a continuous transport cycle. Remarkably, demonstrates an exceptional transport capacity of 280 000 Zn 2+ per cycle. In situ optical microscopy directly visualizes the OND‐driven Zn 2+ trafficking between electrodes, resulting in exceptionally uniform and dense zinc deposition. Finite element simulations further reveal that OND induce beneficial micro‐convection in the electrolyte, simultaneously enhancing both zinc‐deposit homogeneity and electrolyte stability. Consequently, Zn//Zn symmetric cells sustain over 23 000 dendrite‐free cycles at 10 mA cm −2 ; Zn//Cu cells maintain 99.84 % Coulombic efficiency over 8600 cycles; and Zn//MnO 2 full cells retain 89.1 % capacity after 10 000 cycles. This bioinspired ion shuttle strategy establishes a transformative approach for developing dendrite‑free metal batteries, unlocking the potential of AZIBs for safe, long‐duration grid storage.