Life cycle assessment of a lithium-ion battery with a silicon anode for electric vehicles

New lithium-ion battery generations for electric vehicles are constantly being developed. Currently, batteries with silicon and graphite anode enter the market as third-generation batteries, with limited knowledge of their environmental impacts. This life cycle assessment study evaluates the impacts of the entire life cycle of a prototype lithium nickel manganese cobalt oxide (LiNi0.6Mn0.2Co0.2O2) battery with a silicon-rich anode using the ReCiPe 2016 method. This prototype battery is compared to a state-of-the-art graphite-based battery. A sensitivity analysis is carried out, and the uncertainty of the results is quantified using Monte Carlo analysis. The battery emits 265 gCO2eq/kWh delivered over its life cycle (95 % confidence interval = [219;322]). The energy use in the cell manufacturing phase is critical for all environmental impact categories grouped with climate change. The new silicon-based anode does not contribute more than 7 % to the environmental impact categories. The cathode paste production is the main contributor to ozone formation, human non-carcinogenic toxicity, fine particulate matter, terrestrial acidification, mineral resource scarcity and ecotoxicity (terrestrial, freshwater and marine). The results are sensitive to the carbon intensity of the electricity mix used in the manufacturing phase and during charging. Switching to an electricity mix based on renewable energy sources reduces the impact by up to 53 % (for freshwater eutrophication). The impact categories climate change and ozone formation have the lowest coefficient of variation, while water consumption and human carcinogenic toxicity have the highest. Third-generation batteries can be environmentally beneficial, as soon as their cycle life is sufficient: at least 180,000 km.

Publication year:2023

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