Imergy Power Systems has developed an exclusive process that recycles waste to recover vanadium for use in their flow batteries. Below is an interview about the process and its value.
1. Where does the mining slag for Imergy’s vanadium come from?
Depending upon region, we obtain it from several sources and not all mining. It may be from oil refining as sludge, from iron ore processing and mining, and even from fly ash and aluminum by-products
2. How do you process the mining slag to extract useful vanadium and how do your purify it, so that you can use it in batteries?
This is proprietary but there are well-known processes depending upon the source, for extracting vanadium from “waste” materials. The essential point is that we don’t have the same stringent limitations on the vanadium waste constituents, which makes it much easier to use and very much cheaper.
3. What inspired you to recycle vanadium for your flow batteries?
The primary reason was to reduce costs by a significant driver, as was the sustainability aspect – good stewardship.
4. How did you lower the cost of your flow batteries from $500 a kilowatt-hour, to under $300 per kilowatt-hour, and how much lower is the cost than $300?
There are two ways in which we have driven costs down. One, by reducing supply chain costs such as through vanadium sourcing, and secondarily we will drive it down further through volume purchases. To go lower, we will add value engineering: so, design out costs and financially structure our product offering by leasing the electrolyte since it never wears out. The achievable roadmap easily shows $220/kWh as rationale within 2 years.
5. Your CEO said that energy production could become democratized as more people have their own energy producing systems, such as solar power. Would it be possible for these same people to store their energy generated in daytime using flow batteries?
This is exactly what we propose and believe will occur: self-consumption and distributed generation and storage. This will benefit grids and utilities, too, as their expensive peak load system reinforcements will not be required.
6. Researchers at USC made a flow battery using organic compounds to dissolve in electrolyte for a flow battery. Could you see the commercial value of using such compounds instead of a metal like vanadium?
Energy densities are a challenge and the scaling to commercial level is at least a decade away. Organic redox flow battery is intriguing but it is in its infancy. The major technical challenges for this type of batteries are as following:
- Low solubility of organic compounds in aqueous solutions which directly translate to low energy density
- Kinetic reversibility and possible chemical and electrochemical side reactions
- Low current density
In order to reach high performance and cost targets for large-scale energy storage applications, these principle characteristics/properties must be improved.
Image Credit: Imergy Power Systems