Abstract: Aqueous zinc-ion batteries hold considerable promise for grid-scale energy storage, capitalizing on their intrinsic safety, low cost, and environmental benignity. However, the practical deployment of these batteries is severely hampered by the uncontrollable growth of zinc dendrites on the anode during repeated plating/stripping cycles. As the substrate for zinc deposition, the interfacial properties of the current collector have a decisive impact on the zinc deposition behavior. Herein, we report a facile high-temperature annealing strategy to modulate the microstructure of a commercial copper current collector. This reconstruction profoundly influences the zinc deposition mechanism and electrochemical performance. The results demonstrate that annealing treatment induces significant crystallographic reconstruction of the copper current collector, resulting in a preferred orientation dominated by the (111) crystal plane, and effectively reducing the dislocation density and surface defects. Theoretical calculations reveal that the Cu(111) facet provides both a low diffusion barrier for zinc adatoms and the lowest interfacial energy with the Zn(002) plane. This synergistic thermodynamic and kinetic regulation promotes uniform and epitaxial zinc deposition, effectively suppressing dendrite formation and guiding the preferential growth of a (002)-textured zinc layer. Consequently, the modified current collector achieves exceptional plating/stripping reversibility, supporting a prolonged cycle life of over 4000 cycles with an average Coulombic efficiency of 99.9%. When applied to the aqueous zinc-iodine full battery with a zinc-free anode, it maintains a capacity retention rate of over 82% after 700 cycles at a current density of 3 A·g^-1. This work provides fundamental insights and a practical strategy for the design of high-performance current collectors through crystallographic and interfacial engineering.

Key words: copper current collector, zinc-iodine batteries, facet control, high temperature annealing