Synergetic Structural Optimizations of Zinc Anodes and Electrolytes to Enable Zinc–Iodine Batteries with Excellent Low-Temperature Performances
Qingqing Ren, Xinyue Tang, Gang Sun, Yaqing Guo, Yixing Li, Xu‐Lei Sui, Zhen‐Bo Wang
Abstract
Challenges like zinc dendrite growth, hydrogen evolution, and electrolyte freezing hinder the development of aqueous Zn-based batteries. To address these issues, we implemented synergetic structural optimizations. A stress-mediated (002)-textured Zn anode was fabricated and characterized via cross-sectional electron channeling contrast. Additionally, ethylene glycol was used to further promote planar Zn electrodeposition via regulation of its kinetics, with Zn crystal nucleation observed. Interestingly, low concentrations of I – ions were incorporated into the ZnSO 4 electrolyte and formed a hydrophobic inner Helmholtz plane on the Zn anode, effectively suppressing hydrogen evolution. As a result, the modified Zn symmetric battery achieved an impressive 7710 h of stable cycling at 5 mA cm –2 /1 mAh cm –2 and 1800 h at 12 mA cm –2 /6 mAh cm –2 . Furthermore, the modified Zn–I 2 battery demonstrated an outstanding low-temperature performance, delivering a discharge capacity of 89 mAh g –1 at 0.2 A g –1 after 2300 cycles at −30 °C.