Jiang Pengjie, Du Qijun, Lei Chengjun, Xu Chen, Liu Tingting, He Xin, Liang Xiao
State Key Laboratory of Chem/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University Changsha 410082 P. R. China
Chem Sci. 2024 Jan 31;15(9):3357-3364. doi: 10.1039/d3sc06155h. eCollection 2024 Feb 28.
Four-electron aqueous zinc-iodine batteries (4eZIBs) leveraging the I/I/I redox couple have garnered attention for their potential high voltage, capacity, and energy density. However, the electrophilic I species is highly susceptible to hydrolysis due to the nucleophilic attack by water. Previous endeavors to develop 4eZIBs primarily relied on highly concentrated aqueous electrolytes to mitigate the hydrolysis issue, nonetheless, it introduced challenges associated with dissolution, high electrolyte viscosity, and sluggish electrode kinetics. In this work, we present a novel complexation strategy that capitalizes on quaternary ammonium salts to form solidified compounds with I species, rendering them impervious to solubilization and hydrolysis in aqueous environments. The robust interaction in this complexation chemistry facilitates a highly reversible I/I/I redox process, significantly improving reaction kinetics within a conventional ZnSO aqueous electrolyte. The proposed 4eZIB exhibits a superior rate capability and an extended lifespan of up to 2000 cycles. This complexation chemistry offers a promising pathway for the development of advanced 4eZIBs.
利用I/I/I氧化还原对的四电子水系锌碘电池（4eZIBs）因其潜在的高电压、高容量和高能量密度而备受关注。然而，亲电的I物种由于受到水的亲核攻击而极易水解。此前开发4eZIBs的努力主要依赖于高浓度水系电解质来缓解水解问题，尽管如此，这也带来了与溶解、高电解质粘度和缓慢的电极动力学相关的挑战。在这项工作中，我们提出了一种新颖的络合策略，利用季铵盐与I物种形成固化化合物，使其在水性环境中不溶解且不水解。这种络合化学中的强相互作用促进了高度可逆的I/I/I氧化还原过程，显著改善了传统ZnSO水系电解质中的反应动力学。所提出的4eZIB表现出优异的倍率性能和长达2000次循环的延长寿命。这种络合化学为先进4eZIBs的开发提供了一条有前景的途径。
