Zn-I₂ flow batteries, with a standard voltage of 1.29 V based on the redox potential gap between the Zn²⁺-negolyte (−0.76 vs. SHE) and I₂-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⁻²). In addition, the crossover of Zn²⁺ across cation-exchange-membrane also limits their cycle stability. Herein, we propose a chelated Zn(P₂O₇)₂^6- (donated as Zn(PPi)₂^6-) negolyte, which facilitates dendrite-free Zn plating and effectively prevents Zn²⁺ crossover. Remarkably, the utilization of chelated Zn(PPi)₂^6- as a negolyte shifts the Zn²⁺/Zn plating/stripping potential to −1.08 V (vs. SHE), increasing cell voltage to 1.61 V. Such high voltage Zn-I₂ flow battery shows a promising stability over 250 cycles at a high current density of 200 mA cm⁻², and a high power density up to 606.5 mW cm⁻².

Zn-I ₂液流电池的标准电压为 1.29 V，基于 Zn ²⁺ -negolyte（-0.76 vs. SHE）和 I ₂ -posolyte（0.53 vs. SHE）之间的氧化还原电位差，因此受到关注。它们的安全性、可持续性和环境友好性。然而，锌枝晶的显着生长和死锌的形成通常会阻止它们在高电流密度（>80 mA cm ^-2 ）下循环。此外，Zn ²⁺穿过阳离子交换膜也限制了它们的循环稳定性。在此，我们提出了一种螯合的Zn(P ₂ O ₇ ) ₂ ^6- （以Zn(PPi) ₂ ^6-形式提供）正电解液，它有利于无枝晶镀锌并有效防止Zn ²⁺交叉。值得注意的是，利用螯合的 Zn(PPi) ₂ ^6-作为谈判液将 Zn ²⁺ /Zn 电镀/剥离电势转移至 -1.08 V（相对于 SHE），将电池电压增加至 1.61 V。如此高的电压 Zn-I ₂液流电池在200 mA cm ^-2的高电流密度和高达606.5 mW cm ^-2的高功率密度下显示出超过250个循环的良好稳定性。