Vanadium just might be the most environmentally friendly, large-scale battery material in a circular economy.
Environmental stewardship, one of the themes of the World Economic Forum on Africa in Cape Town this week, is not usually associated with the extractive industries.
However, that perception is incorrect. Metals and minerals are integral to all renewable energy technologies. Some of them are relatively easy to recycle, making them eminently suitable for a circular economy. A circular economy, in which as much material as possible is re-used rather than discarded to minimize waste, is the model to which all countries should aspire for their long-term future.
In a circular economy, re-use or recycling is a priority in designing products or services. This is very different from product development in the past, where the focus was on short-term use. Then, the long-term externalities of waste, pollution, climate impact and lack of resources had to be solved by future generations.
The move from polluting fossil fuels to renewable energy in transport and power generation is well underway. But there are also negative economic consequences in making this switch. The exponential growth in electric vehicles is creating a glut of used lithium-ion batteries and this problem will be compounded when the same battery technologies are used for energy storage in very large grid applications.
Considerable work is being done on improving the recyclability of lithium-ion batteries, but the problems remain that it is costly to extract the multiple elements used; there is a fire risk during removal, and the fairly low value of non-cobalt components makes reprocessing uneconomical. There could be a “second life” in re-using car batteries to supporting stationary applications, but eventually, they reach the end of their lives.
Despite these drawbacks, lithium-ion batteries remain the best known available solution for consumer electronics and electric vehicles. However, in stationary storage, the more sustainable option is vanadium redox flow batteries (VRFBs).
A VRFB is designed to last for 20 years or more, meaning that fewer batteries need to be deployed than if lithium-ion ones were used. More importantly, the chemical electrolyte in the battery can be fully re-used once the electrical and mechanical components wear out.
The circularity of vanadium in energy storage is even more impressive when the scenario of redeploying the vanadium from the battery for other uses is considered. If there is no demand for new batteries, that electrolyte can be easily reprocessed by existing vanadium mining and processing facilities, at minimal cost, into products such as ferrovanadium and vanadium pentoxide for use in high-strength steels and specialty alloys and chemicals.
Easy to process
Two factors make vanadium electrolyte relatively easy to process. It is mostly water and only one mineral needs to be extracted — vanadium. Recycling a lithium-ion battery entails separating out lithium, nickel, manganite, and cobalt among other minerals, which is a more complex, costly and energy-intensive process.
These characteristics currently make vanadium the most environmentally friendly, large-scale battery material in a circular economy.
For SA, this creates a massive opportunity in both the energy transition and the circular economy. This country has the largest high-grade deposits of vanadium in the world, so it can benefit from increased vanadium demand through mining. SA also processes most of its vanadium, and these processing plants can be used again in the future to reprocess vanadium electrolyte for other uses, regardless of whether the batteries themselves were deployed here or abroad. That means more jobs for today and in the future.
One of the hurdles in any recycling initiative is the logistics and costs associated with collecting waste, which can make recycling uneconomical. For example, the manufacturers of lead batteries have set up collection chains to take used batteries, but those costs are included in the end price.
For vanadium, a rental structure can be created. Instead of having to pay the full capital cost of a battery upfront — which is influenced by prevailing vanadium market prices — and be presented with the problem of disposing of it when it reaches the end of its life, the operator of the battery pays a smaller fee upfront followed by regular, ongoing rental payments.
Once the battery energy is exhausted, the vanadium can be redeployed into another battery or reprocessed for sale into the steel sector. This structure creates an incentive to recycle the batteries at an attractive cost to the end-user.
The responsibility of policymakers in a circular economy is to factor in the costs upfront for sustainable disposal (not just removal) of technologies that are difficult to re-use or recycle and overtly include this cost in tenders for projects. The carbon tax was recently introduced to address this type of cost for coal and gas. Policymakers also have the power to positively encourage technologies where sustainability is already proven, using tools such as preferential tax treatment or other incentives.