Energy storage, especially of electrical energy, has become one of the most dynamic technology sectors and is now universally recognised for its ability to fundamentally improve everyday life.
In particular, the scale-up of batteries, from portable electronics to electric vehicles and now to very large, or utility-scale applications, has empowered both consumers and companies. Today, for the first time in history, every company has a choice to proactively control its energy use rather than remain at the mercy of energy markets or supplying utilities. Not only does this allow companies to reduce their costs but also it allows them to accurately forecast their future energy expenditures.
The technology of the Vanadium Redox Flow battery (VRFB) combines the performance advantages of flow batteries with the simplicity of using just one natural element – vanadium.
Unlike prominent solid state batteries, such as lead-acid and lithium-ion, flow batteries use a liquid electrolyte to store energy. This allows for near unlimited recharging (or cycling), easy scaling by just adding more electrolyte and negligible performance deterioration over long periods of time. As a result, for daily energy storage of a few hours, flow batteries provide the most cost-effective means to store energy. The advantage of vanadium in particular, lies in its ability to exist in four different oxidation states and its water-solubility, allowing for a simpler battery with fewer inputs and no toxic elements.
How does it work through a peristaltic pump?
A VRFB is charged and discharged by a reversible reduction-oxidation reaction between the two liquid vanadium electrolytes of the battery. Unlike conventional batteries, electrolytes are stored in separated storage tanks, not in the power cell of the battery. During operation these electrolytes are pumped(By peristsaltic pump ) through a stack of power cells, in which an electrochemical reaction takes place and electricity is produced.
What are the advantages of peristaltic pump used in VRFBs?
Peristaltic pumps are mainly used to drive the circulation of electrolyte in the battery system. Through the electrolyte delivery between the external storage tank and the battery stack, the concentration polarization during the charge and discharge process can be eliminated, and energy storage and release can be achieved. Specifically, it is manifested as follows:
Charge and discharge control: By alternating the rotation direction of the pump, the forward and reverse flow of the electrolyte during the charge and discharge phase is achieved to match the change in current direction.
·System integration: Usually two peristaltic pumps (corresponding to the positive and negative electrolytes respectively) are required to ensure that the two electrolytes circulate independently to avoid cross contamination.
·Anti-pollution and corrosion-resistant: The electrolyte only contacts the pump tube (such as corrosion-resistant PTFE material), avoiding direct contact with the metal of the pump body and reducing the risk of contamination.
·Easy maintenance: There is no valve and mechanical seal structure, and only the pump tube needs to be replaced regularly to ensure long-term operation stability.
·Precise flow control: Equipped with digital display and stepper motor drive, the flow adjustment range can reach 0.05-380 mL/min, meeting the needs of different working conditions.
The reliability of peristaltic pumps makes them suitable for a variety of scenarios of vanadium batteries, including grid peak regulation, clean energy storage (such as wind/solar power generation) and large-scale fixed energy storage systems. However, its dependence on liquid electrolyte circulation also limits the application of vanadium batteries in mobile devices.
