Crystal Plane Engineering of Zn Nanosheet Arrays Toward Robust Hybrid Capacitive Energy Storage

Metallic Zn anodes are pivotal for high‐energy Zn‐ion storage but face intractable challenges, typically including dendrite proliferation, parasitic hydrogen evolution reaction (HER), and sluggish ion transport. Here, we report a temporally programmed dual‐phase strategy, coordinating electrolyte solvation manipulation for rationally designed growth of three‐dimensional (3D) Zn architectures. By modulating ZnCl 2 concentrations, we dynamically configure the solvation complexes from [Zn(H 2 O) 6 ] 2+ to [ZnCl(H 2 O) 5 ] + , which steers the epitaxial growth of Zn nanosheet arrays with dominant exposed crystal faces from (101) to (002), thus fundamentally suppressing the dendrites and HER with reduced interfacial impedance (down to only 6.8 Ω s −1 ). Such a crystal plane‐engineered anode exhibits excellent performance with 97.8% capacity retention over 10 000 cycles in Zn‐HSCs, delivering an energy density of 54.1 μWh cm −2 (1.08 mW cm −2 ) and retaining 77% efficiency at 16.7 mW cm −2 . Based on the molecular dynamic simulations and experimental analyses, the mechanism of crystal plane engineering based on concentration‐driven solvation‐topology interplay has been demonstrated, establishing a metastable crystallization paradigm for scalable fabrication of ultra‐stable metal electrodes.