New recycling process for lithium-ion batteries
15.12.2021 The disposal of raw materials used in the production of lithium-ion batteries – like those installed in electric vehicles – has a major environmental impact. That’s why these batteries need to be recycled more efficiently in future. This is one of the goals of the Innosuisse research project launched in November at the Institute for Intelligent Industrial Systems I3S at Bern University of Applied Sciences (BFH) in collaboration with the start-up LIBREC AG, the Swiss Federal Laboratories for Materials Science and Technology (Empa) and the Switzerland Innovation Park Biel/Bienne (SIPBB).
More and more vehicles on the road are now fitted with electric drives. Their drive system batteries have to be disposed of at the end of their lifespan – a process which has much room for improvement in terms of sustainability, efficiency and safety. The start-up LIBREC AG is focusing on this challenge. Around 70% of components can be recycled thanks to a procedure developed and researched at the Technical University of Braunschweig between 2009 and 2016. However, LIBREC aims to optimise this procedure as well as other stages in the recycling process and is collaborating with researchers from BFH, Empa and SIPBB to achieve that goal as part of an Innosuisse project.
Holistic view of process
The research project focuses on six aspects of the recycling process: the characterisation, discharging and dismantling of batteries, the recycling and separation of the electrolyte, the processing of the black mass as well as modelling and the life cycle assessment (LCA).
Characterisation involves accurately determining the battery’s state of health and material composition. This knowledge and an effective procedure for deep discharging of the batteries are key requirements in both pre-sorting batteries for a second-life application or recycling of materials, as well as subsequent safe and efficient battery dismantling. This can only be carried out manually at present. LIBREC also sees room for improvement here as the manual procedure entails high costs. The project aims to develop a semi-automated system and state-of-the-art security technology. The goal is to recycle as much of the materials used as possible by breaking the battery down into its individual components. These include graphite and lithium for which the research project is targeting a recycling rate of 80%. A 95% rate is the goal for cobalt, nickel, copper, manganese and aluminium. This avoids waste and enables sustainable use of raw materials whose extraction has a major environmental impact. To speed up the development and assembly of the process plants and to minimise investment costs, the researchers are using cutting-edge simulation tools rather than prototypes.
Expertise of research partners
BFH researchers have carried out in-depth analysis on the manufacture of batteries and the optimisation of production processes in previous projects. The new research project draws on this knowledge at several points in the recycling process. The researchers will produce digital models of the entire plant to calculate costs. They will also set up pilot plants in the research laboratory which will be used to test and analyse the procedure for separating the electrolyte and the processing of the black mass.
Researchers from the Swiss Battery Technology Center at SIPBB will focus on which batteries can be used for second-life application and how the batteries can be dismantled so that the maximum amount of material can be recycled. They have already explored the electrical and mechanical structure of battery packs in various other projects and will also analyse the lifespan of batteries at the Battery Testing Laboratory, a public-private partnership between SIPBB and BFH.
The Advancing Life Cycle Assessment (ALCA) Group from Empa will bear responsibility for the life cycle assessment of the entire process. It is one of the leading players in this field in Switzerland and possesses vast experience.
Battery recycling from 2024
LIBREC will launch a recycling centre for drive-system batteries in early 2024. All old battery services – such as repair, upcycling and recycling – will be combined at this facility. This will eliminate the need for expensive and safety-critical transport of old batteries over long distances. The energy that can be obtained from discharging batteries fully will provide a third of the process energy required. Depending on raw material prices, the income generated from the sale of the recycled materials from which new batteries will be made should completely cover operating costs. Otherwise, they will be met by charging a disposal fee. Not only will the LIBREC process contribute towards more sustainable resources management but will also achieve impressive energy and cost efficiency.