As electric mobility continues to gain momentum, the recycling of lithium-ion batteries is also becoming significantly more important. Rising battery volumes, volatile raw material markets, regulatory requirements, and ambitious decarbonization targets present industry and research with the challenge of evaluating various recycling processes – under different technical and economic conditions – from both environmental and economic perspectives.

To systematically compare different recycling concepts, the Fraunhofer Research Institution for Battery Cell Production FFB and the Chair of Production Engineering of E-Mobility Components (PEM) at RWTH Aachen University, in collaboration with industry partners, have developed a modular life-cycle approach for evaluating battery recycling processes.

Comparability Through a Modular Structure

A particular challenge in evaluating battery recycling processes is that the various methods have different process structures, energy requirements, recovery rates, and costs. Furthermore, decisions made in early process steps influence material quality, recovery rates, and the effort required in downstream stages.

The “Modular Lifecycle Tool” therefore does not consider individual technologies in isolation but rather maps out the entire recycling chain using a modular principle. The process chain is first divided into the areas of preparation and pretreatment of the recycling material, as well as material recovery. Within these areas, distinctions are made between functions, process steps, and specific technologies.

“The modular structure allows us to compare different technologies within the same process logic,” explains Lucca Groß, a research assistant at the Chair of “Production Engineering of E-Mobility Components (PEM)” at RWTH Aachen University. “For example, the shredding process step can be implemented using various shredder technologies. The different technologies can be specifically swapped out in the model, making it immediately apparent how a technological change affects the entire recycling chain.”

Costs, Material Flows, and Emissions in a Single Model

At the heart of the approach is a database of individual process steps. Users can configure the input stream of a recycling chain – including throughput and material composition – and then assemble customized process chains. The model tracks material flows throughout the entire recycling chain and links them to economic and environmental metrics. Factors taken into account include energy requirements and associated emissions, consumables and auxiliary materials, operating expenses, investment-related costs, revenues from recovered materials, and disposal costs. Site-specific factors such as the electricity mix and labor costs, as well as capacity utilization and economies of scale, can also be incorporated into the analysis.

This does not result in a static cost table, but rather a dynamic evaluation environment for the overall economic balance. If, for example, separation efficiency, throughput, or recovery intensity change, the effects on downstream material flows, costs, revenues, and emissions become apparent.

A Foundation for Investment and Technology Decisions

“With this tool, we aim to make different recycling concepts comparable on a common basis and thereby create a robust foundation for technological and strategic decisions. In this way, the tool supports recycling companies in optimizing existing processes, technology providers in evaluating new solutions, and battery manufacturers in comparing different recycling strategies,” says Benedikt Gruber, research associate at Fraunhofer FFB.

Possible applications include:

• Comparison of alternative recycling concepts within uniform system boundaries 
• Identification of cost and emissions hotspots along the process chain
• Evaluation of scaling strategies and scenarios for industrial ramp-up
• Evaluation of site-specific conditions, including energy supply
• Sensitivity analysis of key technical and economic parameters

In the future, the evaluation framework can be expanded to include additional battery chemistries, more regionally differentiated datasets, and future regulatory scenarios.