Orientational\nElectrodeposition of Highly (002)-Textured\nZinc Metal Anodes Enabled by Iodide Ions for Stable Aqueous Zinc Batteries

Abstract

Regulating\nthe crystallographic texture of the zinc (Zn) metal\nanode is promising to promote Zn reversibility in aqueous electrolytes,\nbut the direct fabrication of specific textured Zn still remains challenging.\nHerein, we report a facile iodide ion (I^–)-assisted\nelectrodeposition strategy that can scalably fabricate highly (002)\ncrystal plane-textured Zn metal anode (H-(002)-Zn). Theoretical and\nexperimental characterizations demonstrate that the presence of I^– additives can significantly elevate the growth rate\nof the Zn (100) plane, homogenize the Zn nucleation, and promote the\nplating kinetics, thus enabling the uniform H-(002)-Zn electrodeposition.\nTaking the electrolytic cell with the conventional ZnSO₄-based electrolyte and commercial Cu substrate as a model system,\nthe Zn texture gradually transforms from (101) to (002) as the increase\nof NaI additive concentration. In the optimized 1 M ZnSO₄ + 0.8 M NaI electrolyte, the as-prepared H-(002)-Zn features a compact\nstructure and an ultrahigh intensity ratio of (002) to (101) signal\nwithout containing the (100) signal. The free-standing H-(002)-Zn\nelectrode manifests stronger resistance to interfacial side reactions\nthan the conventional (101)-textured Zn electrode, thus delivering\na high efficiency of 99.88% over 400 cycles and ultralong cycling\nlifespan over 6700 h (>9 months at 1 mA cm^–2)\nand\nassuring the stable operation of full Zn batteries. This work will\nenlighten the efficient electrosynthesis of high-performance Zn anodes\nfor practical aqueous Zn batteries.