Electric vehicles are becoming increasingly common on Scotland’s streets, but the power that powers them is causing environmental problems.
Now efforts are underway to explore how engineered bacteria can be used to recover critical metals from EV batteries, which would be a major breakthrough in the field of bio-based recycling.
Sustainable biotechnology experts at the University of Edinburgh are exploring the concept of using bacteria to extract metal compounds from lithium-ion batteries.
Once recovered and processed, valuable elements including cobalt, manganese, nickel and lithium could be fed into a new UK supply chain to produce more rechargeable vehicle batteries.
A similar use of microorganisms is used in mining to extract valuable metals from ores. And bacteria have been used to recover materials from electronic waste such as printed circuit boards, solar panels and from polluted water.
However, identifying the right bacteria to effectively target lithium-ion batteries and applying the process to what will eventually become a glut of waste EV batteries would solve one of the biggest problems associated with the shift to green motoring .
It could also be potentially very lucrative: As the first wave of electric vehicle batteries begin to reach the end of their estimated ten-year lifespan, the race is on between tech companies to find effective ways to recycle them.
Second-hand EV batteries can be used for stationary energy storage in offices and commercial settings – although domestic use has raised safety concerns – but finding a way to extract and reuse the rare metals is considered a much better option, allowing further mining and keeping old batteries out of landfills.
In Chile, where large amounts of the world’s lithium lie beneath the Atacama Desert, the water-intensive process of lithium extraction has put pressure on local populations and ecosystems, and has been blamed for the drying up of natural waterways, with impacts on communities and wildlife.
While the nickel found in two-thirds of EV batteries is extracted from rainforests in Indonesia, which also causes environmental problems there.
The Industrial Biotechnology Innovation Center (IBioIC) is supporting the University of Edinburgh’s project to achieve industrial capacity using facilities at the FlexBio center to refine the process in a larger bioreactor.
Meanwhile, bacteria have been selected and developed using the Edinburgh Genome Foundry, based at the University of Edinburgh, to ensure their effectiveness on a large scale.
Using a digester, bacteria are added to battery leachate – the liquid left over after the initial processing stages – to simulate a natural biological reaction.
During the process, the bacteria produce nanoparticles of the metal compounds, resulting in a sediment that can be separated from the residual liquid and filtered.
Testing is being conducted using material recovered from an EV battery previously used in a Nissan Leaf.
Professor Louise Horsfall leads the research team at the University of Edinburgh (Image: contributed)
The latest research is part of the wider lithium-ion battery reuse and recycling (ReLiB) initiative, led by the University of Birmingham and funded by the Faraday Institution – the UK’s independent institute for electrochemical energy storage science, skills development, market analysis, and commercialization at an early stage.
According to the European Automobile Manufacturers’ Association (ACEA), battery electric vehicles accounted for 16.1% of total new car sales between January and June 2023, putting Britain among the top ten European countries in terms of car sales electric vehicles.
While the UK government has confirmed that 80% of new vehicle sales by 2030 must be fully electric, or some other alternative, with carmakers having to pay high costs for any petrol or diesel engine above that threshold.
The growing market and dwindling supplies of metals used in batteries are likely to fuel a race for solutions to find new ways to deal with waste batteries as they reach the end of their life.
While most metals used in EV batteries are currently imported, developing alternative recycling routes could open up a more sustainable UK pipeline of materials.
Professor Louise Horsfall, chair of sustainable biotechnology at the University of Edinburgh and who is leading the research, said: “We often read about initiatives to reduce the cost of EV batteries and improve their performance, but as the green transport market grows, we also need to consider what happens to the technology when it is no longer suitable for use .
“This project is about using advanced sustainable biotechnology to find ways to tackle that challenge and in turn extract some of the most valuable metals that can come back into the sector in the early stages of car production.
“The work of the Edinburgh Genome Foundry to select the best performing bacteria, combined with the scale-up expertise we have accessed through IBioIC, means we are moving in the positive direction of turning the research idea into an industrial reality. ”
IBioIC was founded in 2014 to stimulate the growth of industrial biotechnology (IB) in Scotland. It is a key driving force behind Scotland’s National Industrial Biotechnology Plan, which recently set a new target of £1.2 billion in associated turnover and 4,000 direct employees by 2025 for the industry in Scotland.
Dr. Liz Fletcher, director of business engagement at IBioIC, said: “This project is a great example of how biotechnology can be used to make everyday products and services such as cars and transport more sustainable.
“Nobody wants lithium-ion batteries to end up in landfill, so it’s important to explore different ways to reuse and recycle them.
“The method being developed here has a dual value: it is not only a petrochemical-free way to deal with waste, but can also help to ‘reshore’ the supply chain for rare metals and future battery production.”