Environmental Assessment and Engineering of Lithium-Ion Battery Recycling Systems

Recycling plays a pivotal role in reducing material-related emissions in Lithium-ion battery (LIB) production, along with other motivators, such as supply resilience, expectations of consumers, society, and governments. However, LIB recycling is a complex and dynamic system consisting of different products, processes, and markets. Its assessment requires a concept that can handle this complexity and provides targeted decision support. This research work presents a concept that contributes to the environmental assessment and engineering of LIB recycling systems. It further identifies environmental hotspots and potential mitigation options, enhancing the potential of LIB recycling systems as a supplier of environmentally sustainable battery materials. At the beginning the development of LIBs in electric vehicles is introduced, followed by the motivation behind LIB recycling from a life cycle perspective and the environmental assessment of LIB recycling systems and a definition of the research questions. Afterwards, the theoretical background on LIBs, available LIB recycling technologies, as well as market and legal requirements in Europe is presented. The theoretical background concludes with a description of methods for environmental assessment and engineering in recycling systems, namely Life Cycle Assessment and Life Cycle Engineering. Further, a missing common understanding of recycling systems and quantification of indicators is elaborated. Subsequently, the state of research in the area of environmental assessment of LIB recycling is reviewed. The identified research contributions are categorized and evaluated regarding their perspective on product, process, market, and environment. The identified research gaps highlight the current lack of a concept that allows a prospective and integrated environmental assessment of LIB recycling systems considering jointly product, process and market developments. For the developed concept first a common understanding of battery recycling systems and corresponding indicator quantification are provided. On this foundation a framework for the concept is developed and its modules are explained in detail. The framework is structured based on the Life Cycle Assessment framework according to ISO 14040, extended by a stakeholder analysis at the beginning and Life Cycle Engineering as the final module. Models and evaluations of the product, process and market perspective are integrated along the framework. Additionally, a guide for implementation, that is based on the V-model concept is introduced. Hereafter, three exemplary applications of the concept, with a special focus on the Life Cycle Inventory calculation are presented. The exemplary application provides decision support for three relevant stakeholders: first a battery designer, second a recycling process engineer, and third a market or compliance manager. The results of the model-based assessments reveal in-depth product-process-system interdependencies and identify environmental hot-spots for different assessment perspectives and on different levels. Based on these identified environmental hot-spots a Life Cycle Engineering is conducted assessing potential mitigation options.