Does "Abundant Materials" Equal "Environmentally Benign"?: Life-Cycle Impacts of Sodium-Ion Batteries

The world is ramping up its production capacity for batteries due to their potential to enable a fossil-free energy and transport system. There are several types of battery technologies, both those already existing on the market, e.g., the dominant lithium-ion batteries (LIBs), and so-called next generation batteries (NGBs) that are not yet produced at large scale. For both, it is important to assess the life cycle environmental and resource impacts, as potential burden-shifting can then be identified and addressed. In addition, if battery developers and producers obtain this kind of information before design is locked and manufacturing processes established, making changes is less demanding and costly. The sodium-ion battery (SIB) is one NGB that has promising life cycle environmental and resource performance compared to LIBs, as this NGB is possible to produce with geochemically abundant materials only. While we have previously conducted a cradle-to-gate prospective life cycle assessment (LCA) of the SIB cell production, with cathode active material production based on primary manufacturer data and upscaled production, there is a clear need to extend this system boundary to encompass all phases of the SIB life cycle. We have now conducted a prospective LCA encompassing the whole life cycle of the SIB, i.e., from raw material extraction to end-of-life. Compared to the previous study, the SIB cell production modelling has been updated to represent large-scale production more accurately. In addition, several end-of-life options have been explored, as large uncertainty currently exists regarding this for SIBs. Lastly, decarbonized background scenarios have been considered to understand the environmental potential of SIBs in a fossil-free society. The results reveal the life cycle impacts from cradle to grave, indicating, for example, a reduced environmental burden in production compared to previously published results. Furthermore, the overall results indicate that the SIB obtains lower environmental impacts than the LIB, implying that abundant materials equal environmentally benign(er) in this case.