Single-Crystal Zn Anodes Affording Full-Dimensional Crystallographic Coherence Enabled by Monolayer Graphene-Skinned...

Aqueous Zn metal batteries are promising candidates for large-scale energy storage, yet their practical deployment is hindered by poor Zn reversibility. Although crystallographic engineering can improve Zn electrochemistry, the precise fabrication of single-crystal Zn electrodes with full-dimensional crystallographic coherence remains elusive. Here we report a remote electro-epitaxy (REE) strategy to render high-quality single-crystal Zn electrodes. Using monolayer graphene-skinned Cu(111) substrate as the epitaxial current collector, REE manages to preserve perfect crystallographic inheritance through substrate-potential transmission and accommodate lattice mismatch via interfacial strain relaxation, which is evidenced by theoretical and instrumental characterizations. As a result, the Zn(002) deposits with uniform out-of-plane crystallographic orientation, in-plane crystallographic coherence, and through-thickness crystallographic continuity are achieved on both centimeter-scale foils and 4-inch wafer substrates. The resulting electrodes warrant reversible Zn plating/stripping behavior, enhanced stability under elevated depth-of-discharge conditions, and successful implementation in Ah-scale pouch cells competing the state-of-the-art. Beyond Zn, our strategy is extendable to a multitude of metals, offering a scalable pathway toward single-crystal electrode fabrication for emerging energy storage.