Date: Sep 14, 2018
Vanadium is an abundant silvery-gray metal, cousin to niobium and tantalum, that is primarily mined in China, Russia, South Africa and Brazil. Part one of our vanadium coverage will focus on the invention, use and applications of vanadium batteries.
While there has been a lot of discussion around which metals will be used in electric vehicle (EV) batteries, predominantly in the nickel, cobalt and lithium space, the EV sector isn’t the only one that needs to secure a long term sustainable, green and efficient energy supply.
Vanadium has been pegged as an up and coming energy storage metal especially in relation to large scale applications due to its ability to store extensive amounts of energy.
Invented decades ago, vanadium redox flow batteries, or VRFBs, have only recently gained popularity as a contender for large scale energy storage. VRFBs are a viable option for large scale storage because they are able to provide hundreds of megawatt hours at grid scale. Meaning, they are able to be charged thousands of times without losing capacity, while holding large amounts of energy.
How it works
The positive and negative sides of a vanadium redox-flow battery are separated by a membrane that selectively allows protons to pass through. While charging, the applied voltage causes vanadium ions to lose one electron each on the positive side. The freed electrons flow through the outside circuit to the negative side, where they are stored.
During use, those stored electrons are released, allowing them to flow back through the outside circuit to the positive side.
Image: US Department of Energy
Since their inception in 1984, VRFBs have slowly advanced and refined their storage capacity and delivery technique. The first generation of vanadium batteries weren’t able to hold much energy, roughly 12 to 15 watt-hours per liter of electrolyte.
In order to perform, the batteries had to be extremely large, approximately the size of a one or two basketball courts, making them an unrealistic energy solution.
