▎ 摘　　要

NOVELTY - Removing iron and regenerating electrolyte of an all-vanadium redox flow battery, comprises (i) mixing sulfonated phosphonic acid resin, carbon material and binder to obtain compound, adding organic solvent to mixture, and stirring to obtain slurry, and applying slurry evenly cover surface of graphite plate, and vacuum-drying to obtain complex electrode, (ii) processing single-stage capacitive deionization treatment, and (iii) multi-stage series capacitor deionization treatment by (3.1) connecting primary regenerative complex electrode to DC power supply in forward direction, circulating all-vanadium redox flow battery electrolyte and adsorption, and discharging electrolyte of all-vanadium redox flow battery, (3.2) adding desorbent to capacitive deionization device that discharges electrolyte of all-vanadium redox flow battery, desorbing, and discharging desorbent, connecting primary regenerative complex electrode, and rinsing with deionized water, and repeating 1-4 times. USE - The method is useful for removing iron and regenerating electrolyte of an all-vanadium redox flow battery. ADVANTAGE - The method is simple, economical, environmentally friendly, has no chemical, and improves the performance of the whole vanadium redox flow battery electrolyte after removing iron. DETAILED DESCRIPTION - Removing iron and regenerating the electrolyte of an all-vanadium redox flow battery, comprises (i) mixing sulfonated phosphonic acid resin, carbon material and the binder to obtain a compound, adding organic solvent to the mixture, and stirring to obtain a slurry, and applying the slurry evenly cover the surface of the graphite plate, and vacuum-drying at 40-60°C for 3-6 hours to obtain a complex electrode, (ii) processing single-stage capacitive deionization treatment comprises (a) placing the complex electrode in the capacitive deionization device, and connecting it to the DC power supply in the forward direction, electrolyte of the all-vanadium redox flow battery to be treated is circulated and pumping into the capacitive deionization device for adsorption, and the volume of the electrolyte pumped into the all-vanadium redox flow battery to be treated per minute is the capacity of the capacitive deionization device 5-15% of capacity, turning off the DC power supply, and discharging the electrolyte of the all-vanadium redox flow battery after the primary treatment, (b) feeding a desorbent with a concentration of 2-4 mol/l into the capacitive deionization device that discharges the electrolyte of the all-vanadium redox flow battery after primary treatment, desorbing for 1-3 hours, and discharging the desorbent, connecting the desorbed complex electrode to the DC power supply in reverse, and rinsing it with deionized water for 30-60 minutes to obtain a regenerated complex electrode, (iii) multi-stage series capacitor deionization treatment by (3.1) connecting the primary regenerative complex electrode to the DC power supply in the forward direction, and the voltage of the DC power supply is 0.3-1.2V, circulating all-vanadium redox flow battery electrolyte after the first-level treatment and pumping into the capacitive deionization device for adsorption, and the volume of the all-vanadium redox flow battery electrolyte after the first-level treatment is pumped every minute for 2-6 hours, 5-15% of the capacity of the capacitive deionization device, turning off the DC power supply, and discharging the electrolyte of the all-vanadium redox flow battery after the secondary treatment, (3.2) adding 2-4 mol/l desorbent to the capacitive deionization device that discharges the electrolyte of the all-vanadium redox flow battery after the secondary treatment, desorbing for 1-3 hours, and discharging the desorbent, connecting the primary regenerative complex electrode after desorption to a DC power supply in reverse, and rinsing it with deionized water for 30-60 minutes to obtain a secondary regenerative complex electrode, analogy, and repeating 1-4 times to obtain the electrolyte solution for the all-vanadium redox flow battery regenerated from iron removal.