Ex-ante environmental impact analysis of reactivation methods in the direct recycling of cathode active materials from spent lithium-ion batteries

Recycling is crucial for resilient value chains for lithium (Li)-ion batteries, as is ecological impact analysis, to ensure the sustainability of battery-recycling technologies. Early ecological assessments lead to greater potential for optimization and easier adaptations for the reduction of environmental impacts. In this study, we present an ex-ante life cycle assessment (LCA) of reactivation strategies for separated cathode active materials from end-of-life Li-ion batteries for direct battery recycling. Reactivation includes impurity removal, compensation for Li deficiency by relithiation, and subsequent recrystallization. In this LCA, we focus on the relithiation process as it is decisive for the variance in the reactivation procedure. Our results show that hydrothermal reactivation is associated with the lowest global warming potential across all cathode chemistries. In terms of the abiotic resource depletion (of elements) and human toxicity, solid-state reactivation has the least impacts, followed by hydrothermal relithiation. To better evaluate the ecological relevance of reactivation, we conducted a life cycle impact assessment for the entire direct recycling process chain using two different separation technologies to recover the end-of-life cathode active material. The first separation process is based on semi-automated disassembly, dismantling, and subsequent waterjet delamination of the active material from the collector foil. In the second process, the battery (modules) is mechanically shredded in an atmosphere of inert gas and subsequently fractionated. This enabled us to identify relithiation as a hotspot in the direct recycling process. On average, relithiation is responsible for 40–43 % of the global warming potential. The early ecological analysis proves to be extremely useful in this context, as the greenhouse potential in the overall process chain of strategy.