System Principle

Charge

Discharge

The Vanadium Flow Battery (VFB) is a new technologically advanced type of energy storage battery. It is characterized by itshigh power, large capacity, high efficiency, long design life, high security, and environmental-friendliness.

A VFB consists of electrolyte, cell stack, electrolyte storage tanks, electrolyte circulatory system, and electrical system. Electrolyte is the energy unit, with the function of storing electricity. The amount of electrolyte decides the working capacity of a VFB. Cell stack is the power unit, enabling the conversion from electric energy into chemical energy with a decisive factor on the working power of VFB.

Electrolyte consists of anolyte and catholyte. They are stored in corresponding storage tanks, independent from the cell stack. Active substance of the electrolyte is vanadium in different valences. During operation, the electrolyte is transferred by the electrolyte circulation system and is circulating between the cell stack and the electrolyte storage tanks. Anolyte and catholyte are separated by the perfluorinated ion membrane and react on the anode and cathode respectively, enabling the conversion from electric to chemical energy. The chemical equations for charge and discharge are as below:

 

 

Charge

Discharge

Aanode

VO2+ + H2O – e = VO2+ + 2H+

VO2+ + 2H+ + e = VO2+ + H2O

Cathode

V3+ + e = V2+

V2+ – e = V3+