Using biology to recycle critical metals contained in spent LI-ion batteries (LIBs) from electric vehicles

Successful collaboration between two research facilities demonstrates potential impact for future projects.

Introduction

Bioseparation is a process that uses bacteria to transform dissolved metal ions into solid metal forms. In this project, the partners used fermentation techniques to scale up a process for separating valuable metals from spent Li-ion batteries (LIBs) used in electric vehicles.

Challenge

If the valuable metals contained in the LIBs can be accessed then they can be recycled for use in new LIBs, securing a supply chain that doesn’t rely on virgin materials. To be able to continue to sell into the European market after 2030, the UK will have to ensure that new batteries include recycled metals. There is therefore an economic, as well as environmental, imperative to advance this technology.

As part of the Faraday Battery Challenge programme and EPSRC funded ReLib Project, Professor Louise Horsfall’s research group at the University of Edinbugh had developed a bioseparation process to extract those metal compounds from battery leachate - the liquid that remains after the initial processing stages - and now needed to investigate the scalability of that process.

Solution

The Horsfall group together with Edinburgh Genome Foundry and FlexBio worked together in a new collaboration to deliver a solution to this challenge. Engineered strains of Shewanella oneidensis MR-1 bacteria were assessed and the best peforming strains were investigated at small scale at the EGF facilities using their BioLector microbioreactor system. The scale-up work was performed at FlexBio in 7L and 30L fermenters with both synthetic and real battery leachate. FlexBio also tested disc stack centrifugation as large-scale solution for the recovery of metal nanoparticles after the bioseparation process. Health and safety procedures had to be particularly stringent because of the corrosive nature of the materials being used.

 Outcome

This project demonstrated the potential impact of collaboration between the EGF and FlexBio, working at small scale and larger scale respectively. EGF and FlexBio have toured each other’s facilities and having collaborated successfully on this project, and now hope to continue the partnership on future projects.

The Horsfall group was able to access specialist scientific expertise, technology, pilot-scale equipment, and proof of concept testing to ensure a successful project outcome which has led to research publications, presentations and innovation awards, including the grand prize at the Global Trends Forum by 2050Now La Maison