Assessment of environmental impacts and circularity of lithium-ion batteries

Lithium-ion batteries are complex products with numerous materials, and their life cycle is associated with various environmental impacts. There is a wide range of information available on the environmental impacts of the lithium-ion battery lifecycle from different LCA studies. However, the complexity of the lithium-ion battery value chain and a wide variation in the composition and design, as well as lack of primary data for industrial scale, amongst other, has caused a wide variety in the reported values for carbon footprint and other impacts. Nonetheless, there seems to be a consensus on where the most significant impacts arise: production of the cathode active materials and manufacturing of the battery cells. Also, various hotspots have been recognized related to specific materials and production pathways. While methods and tools are available for carrying out battery LCA studies, there is still a need for better and up-to-date primary data on an industrial scale.For different environmental impacts, most attention has focused on GHG emissions, although in many studies, wider range of impact categories is included. To understand the sustainability of batteries in a more holistic way, it would be beneficial to include a wider set of indicators and not focus only on one indicator. PEF methodology for rechargeable batteries recommends a set of 15 different impact categories to be used in a calculation of the PEF profile, the most important ones being climate change, resource use (energy carriers, and minerals and metals) and respiratory inorganics. Currently, most battery LCA studies are focused on the impacts from manufacturing of battery materials and cells (i.e., cradle-to-gate studies). Less studies are available in which use and end-of-life stages are included. Adding use stage and end-of-life in the analysis adds another layer of complexity due to the difficulty of modelling battery behaviour and the lack of data from real-world applications and recycling. At the same time, excluding the use phase dismisses the effect of varying lifetime and performance on the lifetime environmental impacts.LCA is an established methodology for evaluating wide range of environmental impacts of the products through its life cycle. However, alone it is not enough to assess all the necessary aspects for circular economy of batteries. For example, LCA do not provide information how materials stay in circulation for multiple cycles or their lifetime performance or required production assets, and therefore other CE indicators will be needed. Circularity assessment on the other hand is not as established as environmental impact assessment by LCA. However, ISO 59000 standard series for circular economy is currently under development which aims to give a framework to measure and assess circularity, amongst other. Numerous other indicators have been developed for evaluating circularity, which aim to recognize aspects related to e.g., durability, repairability and usage intensity, however currently there is very little information on their application to the battery value chain. The scope and purpose of different circularity indicators varies, therefore relevant indicators need to be chosen case by case, and for the specific purpose. In this report, three different circularity indicator tools (MCI, Circulytics and CTI) are presented shortly based on their capability to support or complement environmental impact assessment, with a focus on the data requirements for carrying out the assessment. Depending on the case, the results from the circularity assessment may be used to evaluate and compare circular strategies as well as to support sustainable design and decision making, therefore circularity indicators may be also suitable for increasing sustainability in the design phase rather than assessing circularity state of the art