2.1. LCA
The cradle-to-grave GWP results for BEVs and ICEs show that the use phase constitutes the dominant contribution (at 85%) for ICEs to vehicle lifetime greenhouse emissions, whereas material production, especially battery manufacturing, is the largest contribution (at 38%) for BEVs to the life cycle GWP. Figure 1 shows the cradle-to-grave GWP results for the BEV and ICE vehicles per life cycle stage per functional unit, i.e., one vehicle (BEV or ICE). For this (default) scenario (see the results presented in the first row of Table 1), it is assumed that the plastics used in the vehicle have no recycled content.
Temporal variations in electricity grid mixes are an important consideration for a full LCA of BEVs19. In this analysis, the impact of the future electricity grid mix is studied to assess the use-phase performance of BEVs in 2030 and 2050. The application of forecasts for future (2030 and 2050) electricity grid mixes reveal a considerable reduction in the CO2 emissions of BEVs. The BEV emissions are 28%, 50% and 56% lower for 2021, 2030 and 2050, respectively, than those of the ICE (Figure 2).
Using the ReCiPe 2016 midpoint (H) method shows that the BEV out performs the ICE in terms of the GWP, stratospheric ozone depletion and fossil resource scarcity categories. However, the ICE outperforms the BEV for all other impact categories, in line with past findings5. For all three impact categories in which ICE performs below the BEV, the use phase burdens are the dominant factor (Figure 3). For BEVs, mineral resource scarcity is a crucial issue that can be mitigated through recycling or deploying innovative products with lower contributions to mineral resource scarcity. The major contributors to mineral resource scarcity are cobalt sulfate, lithium hydroxide, and copper, which can be recovered in the forms of Me(Ox), Li3PO4 and Cu3(PO4)220. According to Duarto Castro et al.20, overall recycling credits are obtained for terrestrial toxicity, human noncarcinogenic toxicity, toxicity, and mineral resource scarcity but not for the GWP. However, in the BEVSIM model, the net GWP for battery recycling is negative. This contradiction results from different acids being used in the waste battery treatment process modelled in the BEVSIM and in leaching. Acetic acid is reportedly used for the leaching process, whereas sulfuric acid is applied in BEVSIM, leading to a lower burden in waste treatment in terms of the GWP. According to the Ecoinvent database version 3.6, the GWPs of acetic acid and sulfuric acid are 1.6 and 0.12 kg CO2 eq., respectively, although the use of recycled citric acid lowers emissions by up to four times20. Battery leaching is mostly performed using inorganic acids, typically hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid, whereas organic acids include citric acid, oxalic acid and tartaric acid21. Thus, the assumed battery waste treatment plays an important role in the analysis and can influence the results considerably. The production of recycled batteries contributes considerably to the impact category of marine ecotoxicity.
The MCI for each material is 0.627. Steel and aluminium have high circularity indices (0.8 and 0.69) because of reuse and recycling. By contrast, plastics in the current EoL scenario (31% mechanical recycling and incineration for the remaining fraction) have an MCI score of only 0.33. This result is alarming, given industry efforts to use less metal and more plastic and composite parts. Replacement of steel with composites must be coupled with a suitable infrastructure for the reuse and recycling of these components.
Plastics in the automotive industry are reported to consist of 0–20% recycled materials6,22. Changing the recycled content of the plastics from zero to 40% improves the GWP of the plastic parts by 28% overall (Table 2).
According to recent studies, increasing the recycling rate from 3% to 50% improves the levels of carcinogens, noncarcinogens, global warming and nonrenewable energy by 138%, 100%, 42% and 114%, respectively7,23. A 33% pyrolysis share was chosen for the EoL treatment because currently, PO can potentially be pyrolyzed, whereas PU and adhesives can only be incinerated, resulting in a maximum 44% share of mechanical recycling of plastics in EoL treatment7. Table 3 shows the results of 18 impact categories determined using ReCiPe Midpoint H for the four studied scenarios. A 57% reduction in the GWP (considering only emissions related to EoL treatment) is achievable by 33% pyrolysis and 44% mechanical recycling compared with state-of-the-art methods (31% mechanical recycling and 69% incineration). This value was reported to be 42% by Cardamone et al.7 The difference between the two values mainly originates from different assumptions being made about the composition of plastics of the vehicles and the inclusion of dissolution-based recycling by Cardamone et al.7 Improvements were not observed in only three categories, namely, freshwater eutrophication, terrestrial ecotoxicity and land use. An overall comparison of all impact categories for all 4 scenarios (3a–d) did not yield conclusive results; instead, a trade-off among the scenarios was obtained.
2.2. LCC
First, it must be stressed that almost no public cost data for the production of passenger cars are available. Thus, the results shown here are only an indication of the real costs. On average, car producers make a profit of approximately 7.5%24. Data from the main car manufacturers in the European market reveal an average margin of 6.8% over the period of 2021–2023 (see Table 4). The relatively high standard deviation indicates considerable variability in the margin. Of course, the margin for the car producer is directly reflected in the price that the car dealer pays, and the consumer price also includes the costs and margin of the car dealer. As we only knew the consumer prices, we subtracted the costs and margins of the car dealer to obtain the revenues for the car producer. As an estimate, we subtracted 20% of the consumer price25. The manufacturer’s suggested retail price was based on that of the Ford Mustang Mach-E (€60,119) for the BEV and on the Ford Active X 1.0 l EcoBoost (€34,800) for the ICE. Our initial results revealed a very large profit, showing that our costs were underestimated. To solve this issue, ‘missing costs’ were added to the LCC. For BEVs, these missing costs were 9–10% for the BEV and approximately 30% for the ICE. These missing costs for the ICE were quite uncertain but were needed to correctly balance the consumer price.
For the BEV, the estimated material cost of €25,930 is the most important part of the manufacturing cost. For the ICE, the estimated process costs of €11,016 (see Figure 4) is the most important part of the manufacturing cost, and the estimated material costs are €5,135. The NMC battery (€21,265) dominates the material costs for the BEV, followed by the electric engine (see Figure 5). As battery costs have been dropping and will continue to drop, the development of the battery price was further analysed. A modified learning rate was derived to estimate the time range over which the battery price would drop. From 2014 onwards, the battery price steeply declines for some years and then decreases more gradually. Mauler et al.26 reported (but did not analyse) this apparent change trend. Battery prices, but not production volumes, are available from 2010 onwards. Thus, the learning curve was modified to use the number of years after 2014 (26,27) instead of the production volumes. The following relation was thereby found:
The battery price predicted using Formula [1] for the year 2030 was 20 €/kg (see Figure 6). Even with the forty percent drop in the NMC battery price from 34 EUR/kg in 2021 to 20 EUR/kg in 2030, the battery remains by far the most important cost item of the BEV in 2030. For the other materials, it was not possible to estimate the 2030 prices, and we had to assume that the other cost items would not change by 2030. In this case, the predicted total cost for BEVs will decrease by 20% in 2030; however, the total costs still exceed those of a comparable petrol ICE vehicle (see Figure 4).