On the source of metals and the environmental sustainability of battery electric vehicles versus internal combustion engine vehicles: The lithium production case study

Several studies support that the battery electric vehicles (BEVs) are more environmentally friendly than internal combustion engine vehicles (ICEVs). However, these studies assume that one unit of metal used in the manufacturing process is a commodity in terms of its environmental footprint. In this study, estimations for water and energy consumption and carbon dioxide emissions are used as proxies of the environmental footprint variability within the production of various metals used in the automotive industry. Through these estimations, probability distribution functions are fit to assess the sustainability of BEVs and ICEVs when considering the commodities' environmental heterogeneity.Two scenarios are assessed, which considers: (1) the manufacture of vehicles, and (2) their useful life. The results show the existence of a range of potential environmental footprints for BEVs and ICEVs, depending on the footprints of the specific metals being used. Including this input's variability, when only the manufacturing process is considered, ICEVs outperform BEVs in most of the realization cases and for all the analyzed indicators. However, if their useful life is incorporated, the BEV consistently produces significantly less carbon dioxide emissions, as well as consume the same energy and more water than ICEV.A special case study for lithium is presented as it has shown to be a critical resource and a major environmental concern for BEV production. The results show that by switching lithium from pegmatite to brine, the water consumption required for manufacturing the vehicles is reduced by 0.17%, which is contrary to the common view regarding water use in brine extraction.