Enabling Active Defect Healing via Lateral Spread Growth for Highly Reversible Zinc Anodes

Abstract

The commercialization of aqueous zinc ion batteries is severely hindered by the formation of mossy, porous structures and dendrites on Zn anodes. This disordered morphological evolution fundamentally stems from the intrinsic anisotropy of the Zn crystal structure and the heterogeneous distribution of highly energetic defect sites on the surface of commercial Zn foils. This dual instability in kinetics and thermodynamics induces the preferential accumulation of Zn2+ at local active sites during deposition, thereby triggering chaotic vertical growth. Herein, we propose an interfacial regulation strategy to fundamentally reshape the electrocrystallization process, thereby inducing the lateral growth of Zn. This highly directional growth mode suppresses vertical dendritic protrusions and promotes the lateral spreading of Zn atoms along the basal plane, thereby constructing a highly compact deposition layer. Notably, even in the presence of severe interfacial scratches, this strategy achieves effective leveling of surface irregularities and compact coverage, endowing the deposition layer with exceptional self-healing capabilities. Consequently, the Zn||Zn symmetric cells demonstrate an ultralong lifespan exceeding 6750 h (~9.4 months) at 1 mA cm-2 and 1 mAh cm-2, while the Zn||NaV₃O₈ full cells deliver a high specific capacity of 211.29 mAh g-1 at 3 A g-1. These results validate the significant efficacy of inducing lateral spread growth and active defect repair in reshaping the stability of Zn anodes.