The basic principle of all-vanadium redox flow battery
2022-01-12
In the all-vanadium redox flow battery system, vanadyl sulfate in sulfuric acid solution acts as the initial electrolyte on both sides. The same elements in different oxidation states can be interconverted at the electrodes. Figure 4 shows the basic schematic of the VRFB.
At the positive electrode, the V(IV)/V(V) redox pairs are typically VO 2 + and VO 2 -:
VO2++H2○-e-→VO2++2H+ charge
VO2++2H++e-→VO2++H2○ release
E 0 = + 1.00 V with SHE
At the negative electrode, the V(II)/V(III) redox couple is either the vanadium(II) ion or the vanadium(III) ion:
five 3++e-→five 2+ charges and five 2+-e-→five 3+release
E 0 = − 0.26 V with SHE
The standard open circuit potential of the all-vanadium system is 1.26 V, but the actual open circuit potential depends on the operating temperature, active species concentration and state of charge. For example, for a fully charged battery with 2 M active species, the open circuit potential is 1.6 V. Sulfuric acid is usually used as the supporting electrolyte, and hydrogen ions pass through the membrane to maintain the current.
Due to the relatively fast kinetics and high reversibility of these two vanadium redox reactions, high Coulombic and voltage efficiencies can be expected at large current densities. VRFB can be overcharged and overdischarged within the limits of electrolyte capacity, and it also eliminates gassing problems during fast charge cycles. Due to these important properties, the performance of VRFBs has improved significantly over nearly 30 years.
About News
- VFB-1KW all-vanadium flow energy storage system
- Vanadium battery market prospect
- Application of Vanadium redox flow battery
- How Vanadium redox flow battery Work?
- Power battery recycling will help alleviate the demand for metal resources
- Significance of power battery recycling
- VFB-125kW all-vanadium liquid flow energy storage system
- New energy vehicle battery after scrap recycling method
- Diluted high-concentration electrolyte improves LMB cycling performance, study finds
- All-Vanadium Redox Flow Battery Energy Storage
Products