Engineered bacteria may be the key to EV battery recycling

Researchers have found that engineered bacteria could be the key to recovering metals from electric vehicle (EV) batteries at the end of their life.

A team of sustainable biotechnology specialists at the University of Edinburgh, led by Professor Louise Horsfall, are exploring this concept. The bio-based recycling process will use bacteria to extract metallic compounds from lithium-ion batteries. Once recovered and processed, these elements – including cobalt, manganese, nickel, and lithium – could feed into a “new UK-based supply chain for rechargeable vehicle batteries”, the researchers said. 

The Industrial Biotechnology Innovation Centre (IBioIC) is supporting the project to reach industrial capacity, using facilities at its FlexBio centre in Edinburgh to refine the process in a larger bioreactor. In the meantime, bacteria have been selected and engineered using the Edinburgh Genome Foundry, based at the University of Edinburgh, to ensure their effectiveness at scale.   

Using a fermenter, bacteria are added to battery leachate – the liquid that remains after the initial processing stages – to simulate a natural biological reaction. During the process, the bacteria produce nano-sized particles of the metallic compounds, resulting in a sediment that can be separated and filtered out from the residual liquid.

The latest research forms part of the wider Reuse and Recycling of Lithium-Ion Batteries (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 early-stage commercialisation.

According to the European Automobile Manufacturers’ Association (ACEA), battery EVs accounted for 16.1% of total new cars between January and June 2023, making the UK one of the top 10 European countries for EV sales. As the market grows, so does the need for initiatives that can support the increasing supply chain pressures and deal with waste batteries as they come to the end of their useful lifetime. 

As the reserves and resources of metals used in batteries decline, increasing amounts of raw minerals will reside in existing batteries themselves. At the moment, the majority of metals used in EV batteries are imported. Developing alternative recycling routes could open up a more sustainable UK-based pipeline of materials.

Professor Horsfall, chair of sustainable biotechnology at the University of Edinburgh, said: “We often read about initiatives to reduce EV battery costs and improve their performance, but as the market for green transport grows, we also need to consider what happens to the technology once it is no longer fit for use. This project is about using cutting-edge sustainable biotechnology to find ways of tackling that challenge and, in turn, extract some of the most valuable metals that can go back into the sector at the early stages of vehicle production.

“The work of the Edinburgh Genome Foundry to select the best performing bacteria, combined with the scale-up expertise we’ve been able to access via IBioIC, means we are heading in a positive direction towards turning the research idea into an industrial reality.”