Plating-Induced Stress Heterogeneity Dictates Zinc Dendrite Growth

Dendrite formation on Zn metal anodes remains a major obstacle to the practical deployment of aqueous Zn-ion batteries. The plating-induced stress in Zn anodes and its effect on Zn-deposition morphologies have not been fully elucidated. Herein, we establish a direct correlation between plating-induced stress and dendrite initiation. We reveal that localized tensile/compressive-stress heterogeneity modulates the chemical potential of deposited Zn, generating spatial chemical-potential gradients and nonuniform deposition kinetics at the Zn/electrolyte interface. Such stress-induced chemical-potential differences promote preferential Zn growth at protruded regions and accelerate interfacial instability, whereas stress homogenization suppresses localized deposition and mitigates dendrite evolution. Based on this, we introduced a stress-relieving additive that selectively adsorbs on Zn (100) facets and guides a (100) textured Zn anode. This flattens the Zn deposition and establishes a homogeneous compressive-stress distribution with reduced local chemical-potential differences, effectively suppressing stress-driven dendrite formation. Consequently, the Zn anode has a high cycling life of 3500 h in the symmetric Zn||Zn cell. The Zn||I2 full cell shows remarkable long-term stability exceeding 10,000 cycles at 2 A g-1. This work unveils the intrinsic interplay between stress evolution and dendritic morphology, providing a viable interfacial stress-regulation strategy for dendrite-free metal anodes.