Environmental Impact Analysis of Aprotic Li–O₂ Batteries Based on Life Cycle Assessment

Abstract

Aprotic lithium−oxygen (Li−O 2 ) batteries are a prominent example of ultrahigh energy density batteries. Although Li−O 2 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 highperformance Li−O 2 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−O 2 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•CO 2 equiv in Global Warming Potential for the whole Li−O 2 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−O 2 batteries within a circular economy perspective.

Life Cycle Analysis of Lithium–Air Batteries Designed with TEGDME-LiPF6/PVDF Aprotic Electrolytes

“…While the anode affects an average of 10.3% of the GWP, this ratio for the electrolyte is determined to be an average of 3.1%. In the study, this effect of the electrolyte was compared with Li–S batteries, and it was stated that the very high GWP effect of the Li–S batteries from the electrolyte decreased considerably in Li–air batteries …”

“…Despite intensive laboratory work to develop the Li–air battery technology, studies in the literature on the possible environmental effects of this new battery technology are very limited. In spite of extensive LCA analysis for the Li-ion batteries, there seem only three published studies on the Li–air batteries, which are known to possess the highest theoretical energy density for future energy-storage applications. ,, …”

“…As a result, it has been stated that the environmental effects of Li–air batteries are largely due to cathode and electricity production. When compared with Li-ion, Li–S, and Na-ion batteries, they revealed that the environmental impact of Li–air batteries is lower …”

“…In spite of extensive LCA analysis for the Li-ion batteries, there seem only three published studies on the Li−air batteries, which are known to possess the highest theoretical energy density for future energy-storage applications. 16,26,27 Zackrisson et al, in 2016, analyzed lithium−air cells from the cradle to the grave to highlight the environmental hot spots of such batteries and facilitate their improvement. They performed an LCA by comparing performances obtained experimentally and expected to be improved in the future for the battery cells assembled with aprotic TEGDME + LiClO 4 electrolyte and GDL + Co 2 O 3 /CNT cathode.…”

“…When compared with Li-ion, Li−S, and Na-ion batteries, they revealed that the environmental impact of Li− air batteries is lower. 27 It has been detected that there is no LCA work with the ceramic nanoparticles and polymer additions to the TEGDME + LiPF 6 electrolytes, and it is expected to contribute to the relevant literature with this study.…”