Ordered zinc electrodeposition from single-crystal units to polycrystalline stacking within solid-electrolyte interphase in battery anodes

Controlling Zinc (Zn) nucleation and subsequent crystal growth are critical for long lifespan aqueous zinc metal batteries. However, the concurrent side reactions and unstable solid-electrolyte interphase (SEI) formations impedes the continuous Zn metal electrodeposition. Herein, induced by a well-designed organic/inorganic dual-phase SEI, we realize ordered zinc electrodeposition of polycrystalline stackings from single-crystal building blocks. The uncommon SEI with appropriate ion transport kinetics and thermodynamic stability protects deposited zinc from side reactions of hydrogen evolution and metal corrosion, enabling rapid and long single crystal Zn nucleation, followed by mitigated crystal growth, and ultimately dense polycrystalline stacking without dendrites. Benefited from the above advantages, the Zn | |Zn symmetric batteries exhibit long lifespan exceeding 5600 h and high depth of discharge of 85.0 %, and the Zn | |I₂ full cell delivers a high capacity of 201.9 mAh g^-1 at -30 ^oC. Furthermore, the practical 0.1 Ah Zn | |I₂ bilayer pouch cell can stably operate for 113 cycles with a high specific energy of 122.1 Wh kg^-1 with a low N/P capacity ratio of 1.5. Our findings advance the understanding of critical roles of SEI on zinc electrodeposition behaviors and provide valuable insights into crystal structure regulation during electrodeposition in other metal batteries.