Method and device for recycling electrolyte of flow battery

A device for regenerating an electrolyte liquid of a flow battery comprising

• 1) a first flow battery, which comprises:
• a first anode;
• a first cathode;
• a first separator provided between the first anode and the first cathode;
• an anode electrolyte liquid storage unit that supplies a first anode electrolyte liquid to the first anode and that stores the first anode electrolyte liquid that is discharged from the first anode;
• a cathode electrolyte liquid storage unit that supplies a cathode electrolyte liquid to the first cathode and that stores the cathode electrolyte liquid that is discharged from the first cathode;
• and
• 2) a second flow battery for regeneration, which comprises
• a second anode cell;
• a second cathode cell;
• a second separator provided between the second anode cell and the second cathode cell;
• a mixed electrolyte liquid storage unit to which, after operating the first flow battery through repeating charge and discharge and then stopping an operation of the first flow battery, the first anode electrolyte liquid and the cathode electrolyte liquid are introduced from the anode electrolyte liquid storage unit and the cathode electrolyte liquid storage unit and mixed to produce a mixed electrolyte liquid;
• and
• an aqueous acid solution storage unit storing an aqueous acid solution comprising sulfuric acid, hydrochloric acid, nitric acid or a mixture thereof,
• wherein through an operation of the second flow battery for regeneration, the mixed electrolyte liquid in the mixed electrolyte liquid storage unit is converted to a regenerated electrolyte liquid.