Lithium-based nonaqueous redox flow batteries (LRFBs) are alternative systems to conventional aqueous redox flow batteries because of their higher operating voltage and theoretical energy density. However, the use of ion-selective membranes limits the large-scale applicability of LRFBs. Here, we report high-voltage membrane-free LRFBs based on an all-organic biphasic system that uses Li metal anode and 2,4,6-tri-(1-cyclohexyloxy-4-imino-2,2,6,6-tetramethylpiperidine)-1,3,5-triazine (Tri-TEMPO), N-propyl phenothiazine (C3-PTZ), and tris(dialkylamino)cyclopropenium (CP) cathodes. Under static conditions, the Li||Tri-TEMPO, Li||C3-PTZ, and Li||CP batteries with 0.5 M redox-active material deliver capacity retentions of 98%, 98%, and 92%, respectively, for 100 cycles over ~55 days at the current density of 1 mA/cm² and a temperature of 27 °C. Moreover, the Li||Tri-TEMPO (0.5 M) flow battery delivers an initial average cell discharge voltage of 3.45 V and an energy density of ~33 Wh/L. This flow battery also demonstrates 81% of capacity for 100 cycles over ~45 days with average Coulombic efficiency of 96% and energy efficiency of 82% at the current density of 1.5 mA/cm² and at a temperature of 27 °C.

锂基非水氧化还原液流电池（LRFB）因其较高的工作电压和理论能量密度而成为传统水性氧化还原液流电池的替代系统。然而，离子选择性膜的使用限制了LRFB的大规模应用。在这里，我们报告了基于全有机双相系统的高压无膜 LRFB，该系统使用锂金属阳极和 2,4,6-三-(1-环己氧基-4-亚氨基-2,2,6,6-四甲基哌啶）-1,3,5-三嗪（Tri-TEMPO）、N-丙基吩噻嗪（C3-PTZ）和三（二烷基氨基）环丙烯（CP）阴极。在静态条件下，具有 0.5 M 氧化还原活性材料的 Li||Tri-TEMPO、Li||C3-PTZ 和 Li||CP 电池在 100 小时内的容量保持率分别为 98%、98% 和 92%。在 1 mA/cm ²的电流密度和 27 °C 的温度下循环约 55 天。此外，Li||Tri-TEMPO (0.5 M) 液流电池的初始平均电池放电电压为 3.45 V，能量密度约为 33 Wh/L。^{该液流电池在 1.5 mA/cm 2}的电流密度和 27 °C 的温度下，在约 45 天内循环 100 次后仍具有 81% 的容量，平均库仑效率为 96%，能量效率为 82% 。