The greenhouse gas emissions of automotive lithium-ion batteries: a statistical review of life cycle assessment studies

Abstract

Worldwide sales of battery electric vehicles (BEVs) have been steadily increasing for several years and now account for several million vehicles, resulting in a high use of lithium-ion batteries (LIBs). It is then required to assess the real environmental impact of these LIBs and to avoid environmental impacts' transfers. Life cycle assessment (LCA) methodology seems the most appropriate framework as it is a multi-stages and environmental multi-criteria ISO methodology. However, many studies exist on this subject and no consensus is emerging on a common environmental value of LIB's production. To fill this gap and properly assess the environmental consequences of a massive electrification deployment, this study performs a qualitative and a quantitative review of more than 500 LCA studies referring to LIBs' production for BEVs. 377 observations for seven selected variables among more than 80 surveyed variables are presented and meta-analysis (MA) methodology is used to compare the final 32 selected studies. After many statistical tests and 8 finalists selected, we find that the global warming potential (GWP) impact of mobile LIBs' production can be explained by a reduced parametrized model containing four information: the geographical location of the corresponding author, the cell design of the battery, the battery specific energy, and the manufacturing energy. This allows a generic and systematic approach to assess GWP impacts of LIBs production. We also propose recommendations for LCA practitioners to harmonize LIBs' environmental assessments and save time for further analysis.