Stress Prerelease‐Driven Dendrite‐Free Growth Mechanism to Stabilize Zn Anodes

Abstract

AbstractThe mechanical properties of zinc anodes in rechargeable zinc‐based batteries are neglected. Indeed, electrode stress in zinc crystallization (ESZC) contributes to excess chemical potential under enormous deposition stress, severely impacting zinc crystal patterns and reaction kinetics. Herein, a stress prerelease mechanism to minimize ESZC and drive dendrite‐free zinc anode growth is proposed. The internal stress of the freestanding electrode is prereleased by full‐contact soft‐substrate constraints during fabrication. Under the compression of crystallization stress, the freestanding electrode rapidly deforms and self‐releases into microstrains to reduce ESZC. Furthermore, the weakening of ESZC under the stress‐prerelease mechanism is modified to the actual reaction kinetics, which establishes a direct link between electrode stress and zinc deposition pattern. The processes of crystalline stress transfer and self‐release under the stress prerelease mechanism are revealed using in situ strain monitors. Stress‐prereleased freestanding electrodes drive uniform zinc nucleation and subsequent radial diffusion, guiding Zn epitaxial growth on the nanofibers surface. During repeated deposition/stripping, the stress prerelease mechanism steadily diminishes the possibility of dendrite growth and guarantees the stable operation of dendrite‐free zinc anodes. The stress prereleased freestanding electrodes induce symmetric and full cells to achieve stable and excellent performance.