Wang Caixing, Gao Guoyuan, Su Yaqiong, Xie Ju, He Dunyong, Wang Xuemei, Wang Yanrong, Wang Yonggang
Institute of Innovation Materials and Energy, School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou, Jiangsu, China.
School of Chemistry, Xi'an Key Laboratory of Sustainable Energy Materials Chemistry, State Key Laboratory of Electrical Insulation and Power Equipment, Engineering Research Center of Energy Storage Materials and Devices of Ministry of Education, Xi'an Jiaotong University, Xi'an, China.
Nat Commun. 2024 Jul 24;15(1):6234. doi: 10.1038/s41467-024-50543-2.
Zn-I flow batteries, with a standard voltage of 1.29 V based on the redox potential gap between the Zn-negolyte (-0.76 vs. SHE) and I-posolyte (0.53 vs. SHE), are gaining attention for their safety, sustainability, and environmental-friendliness. However, the significant growth of Zn dendrites and the formation of dead Zn generally prevent them from being cycled at high current density (>80 mA cm). In addition, the crossover of Zn across cation-exchange-membrane also limits their cycle stability. Herein, we propose a chelated Zn(PO) (donated as Zn(PPi)) negolyte, which facilitates dendrite-free Zn plating and effectively prevents Zn crossover. Remarkably, the utilization of chelated Zn(PPi) as a negolyte shifts the Zn/Zn plating/stripping potential to -1.08 V (vs. SHE), increasing cell voltage to 1.61 V. Such high voltage Zn-I flow battery shows a promising stability over 250 cycles at a high current density of 200 mA cm, and a high power density up to 606.5 mW cm.
锌碘液流电池基于锌负极电解液（相对于标准氢电极电位为-0.76V）和碘正极电解液（相对于标准氢电极电位为0.53V）之间的氧化还原电位差，标准电压为1.29V，因其安全性、可持续性和环境友好性而受到关注。然而，锌枝晶的大量生长和死锌的形成通常会阻止它们在高电流密度（>80mA/cm²）下循环。此外，锌穿过阳离子交换膜也限制了它们的循环稳定性。在此，我们提出一种螯合的Zn(PO)（表示为Zn(PPi)）负极电解液，它有助于无枝晶锌电镀并有效防止锌的交叉。值得注意的是，使用螯合的Zn(PPi)作为负极电解液将锌/锌电镀/剥离电位移至-1.08V（相对于标准氢电极），使电池电压提高到1.61V。这种高电压锌碘液流电池在200mA/cm²的高电流密度下经过250次循环显示出有前景的稳定性，以及高达606.5mW/cm²的高功率密度。
