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Abstract

Dendrite formation is a long-standing problem for the commercial application of rechargeable metal anode batteries. The well-controlled coating on anodes can solve the problem of instability and uncontrolled reactions between electrodes and electrolytes. Understanding the effects of pre-stressed (residual stress) electrodes with an artificial solid-electrolyte inter-phase layer (thin film) on dendrite formation is crucial for the successful application of stable anodes. This thesis presents a combined experimental and computational investigation to elucidate the effect of coatings on the electro-chemo-mechanical performance of zinc (Zn) batteries through the incorporation of mechanical stresses and their effect on dendrite formation. To understand the underlying mechanism of how coating affects battery anodes, we used density functional theory-informed continuum modeling and phase-field modeling to unveil the impacts of residual stresses on surface evolution. First, the chemo-mechanical stability of alucone-coated Zn surfaces was examined using density functional theory, revealing strong chemisorption and the development of in-plane compressive surface stress. These stresses, arising from interfacial reconstruction, were found to be orientation-dependent and correlated with reduced surface stiffness, highlighting the mechanical impact of thin-film adhesion at the atomic level. Building on these insights, a continuum model was developed to quantify hetero-epitaxial residual stress due to lattice mismatch between the coating and the Zn substrate. Analytical predictions, supported by finite element simulations and wafer curvature experiments, confirmed the presence of substantial compressive stress (ranging from ~3–5 GPa for alumina to ~0.85–1.2 GPa for alucone). Finally, the effect of residual stress on dendrite growth was explored using in-situ optical microscopy and phase-field modeling. Experiments demonstrated that ultrathin-coated Zn anodes exhibit more uniform electrodeposition and suppressed dendritic features than bare anodes. Phase-field simulations containing stress effects revealed that compressive stresses lower the local electrochemical potential at dendrite tips, redirecting ion flux and smoothing the deposition front. Together, these results provide mechanistic evidence that residual stress, particularly hetero-epitaxial stress induced by nanometric coatings, can serve as a controllable design parameter to inhibit dendrites. The methodologies and findings in this work are broadly extendable to other metal anodes such as lithium and sodium, offering a generalizable framework for engineering stable interfaces in next-generation batteries.