Purification of high-performance vanadium electrolyte from Al-containing solutions via NH 4 Al(SO 4 ) 2 ·12H 2 O crystallization and saponified P204 (D2EHPA) extraction

作者：Hong Liu, Tao Liu, Yimin Zhang, Hongru Qu, Youwen Hu · 发表于：Arabian Journal of Chemistry · 年份：2025 · DOI：10.25259/ajc_881_2025 · 被引用次数：9 · 研究领域：Advanced battery technologies research、Vanadium and Halogenation Chemistry、Metal Extraction and Bioleaching

Traditional vanadium electrolyte production faces challenges of complex processes, high costs, and inefficient impurity removal. This study developed an integrated crystallization-solvent extraction method to directly produce high-performance electrolyte from high-aluminum vanadium shale leachate (Al: 21.2 g/L, V: 54.2 g/L). Through ammonium alum crystallization under optimal conditions (NH 4 + /Al 3 + =1:1, 5°C, 6 h), 51.67% aluminum was removed with <1% vanadium loss. Subsequent five-stage countercurrent extraction achieved 96.04% vanadium recovery, while four-stage stripping produced a 2.0 mol/L V electrolyte. The obtained electrolyte exhibited excellent properties: viscosity of 5.00 mm 2 /s, conductivity of 253.7 mS/cm, and electrochemical performance comparable to commercial standards. Battery tests demonstrated outstanding stability with average coulombic efficiency of 87.86%, voltage efficiency of 93.00%, and energy efficiency of 81.70% over 80 cycles at 40 mA/cm 2 . This short process offers strong potential for industrial application in vanadium redox flow batteries.