Vanadium Electrolyte (VE)
Global market size is limited by conversion of byproduct from steel production and other disruptive secondary supply streams.
There is currently no primary production worldwide
2015 global VE production capacity =
400 MWh of electrolyte
Energy in a VRB is a separate asset and does not deplete in the way energy is normally lost from other battery systems. Energy is stored chemically in different forms of a single element – Vanadium – in a proprietary electrolytic mixture. The liquid Vanadium electrolyte is held plastic storage tanks. The storage tanks hold exactly the same liquid chemistries, so there is no crosscontamination or rebalancing of the electrolyte. The electrolyte does not contain any heavy metals like lead, nickel, zinc or cadmium. There is no environmental disposal requirement. The electrolyte is not flammable. There are virtually no emissions from the system. The entire system runs at low pressure and room temperature, anywhere from 50 to 90 degrees Fahrenheit. And because the electrolyte doesn’t degrade, it is reusable – an asset that retains its value for the owner. Storage duration in a VRB thus becomes simply a function of the amount of electrolyte in the storage tanks. In other words, unlike Zinc-Bromine or Lithium-ion batteries, a VRB affords completely independent scaling of power (kW) and energy (kWh). Sizing of the system can be tailored to a number of factors, such as the capacity of the onsite renewable energy installation or duty cycle requirements.
Conventional production of a primary vanadium producer would equate to ~1,600 MWh/annum based on 8000 tonnes V2O5 /annum
The key element of vanadium flow batteries is the electrolyte itself representing close to half of the value of the battery. Local production in North America and direct process are key considerations to alleviating reliance on disruptive and higher cost supply streams. Primary low cost stable supply is the last remaining challenge to accelerate commercialization of VRB technology. Vanadium flow batteries are a proven technology ideally suited for most grid scale energy storage applications.
Currently less than 1% of world vanadium consumption can be attributed to battery use. Lack of domestic supply of vanadium electrolyte keeps the local price of vanadium electrolyte extremely high. VRB battery manufacturers in North America currently purchase vanadium electrolyte between $7.50-$20.00 USD /LB V2O5 EQ.
Electrochemical flow cell systems, also known as redox flow cells, convert electrical energy into chemical potential energy by means of a reversible electrochemical reaction between two liquid electrolyte solutions. In contrast with conventional batteries, redox flow cells store energy in the electrolyte solutions. Therefore, the power and energy ratings are independent, with the storage capacity determined by the quantity of electrolyte used and the power rating determined by the active area of the cell stack.
2015 was a record breaking year for energy storage growth which substantially increased vanadium battery development, investment, deployment and supply concerns.
Tradional preparation of vanadium electrolyte (VE)
Commercially available V2O5 is only slightly soluble in sulfuric acid
Existing chemical methods of electrolyte preparation are costly
This new method reduces the vanadium at the negative electrodes, but oxidation at the positive electrode is prevented by the small area
Measured amounts of V2O5 powder and H2SO4 are added in a continuous process