Environmental impact analysis of aprotic Li–O2 batteries based on Life Cycle Assessment

Abstract

Aprotic lithium–oxygen (Li–O2) batteries are a prominent example of ultrahigh energy density batteries. Although Li–O2 batteries hold a great potential for large-scale electrochemical energy storage and electric vehicles, their implementation is lagging due to the complex reactions occurring at the cathode. Great effort has been applied to find practical cathodes through the incorporation of different materials acting as catalysts. Here we tap into the quantification of the environmental footprint of seven high-performance Li–O2 batteries. The batteries were standardized to feed a 60 kWh electric vehicle. Life cycle assessment (LCA) methodology is applied to determine and compare how different batteries and respective components contribute to environmental footprints, categorized in 18 groups. To get a bigger picture, results are compared with the environmental burdens of a reference lithium ion battery, reference sodium ion battery, and the average value of lithium–sulfur batteries. Overall, Li–O2 batteries present lower environmental burdens in 9 impact categories, with similar impacts in 5 categories in comparison with lithium–sulfur and lithium ion batteries. With an average value of 55.76 kg·CO2 equiv in Global Warming Potential for the whole Li–O2 battery, the cathode is the major contributor, with a relative weight of 44.5%. These results provide a road map to enable the practical design of sustainable aprotic Li–O2 batteries within a circular economy perspective.