This study provides insides on the environmental impacts of the lab-scale production of two different sodium-ion batteries (SIBs). It highlights the hotspots and is one of the few to provide primary life cycle inventory data on the production processes for SIBs.

Sodium-ion batteries (SIBs) are considered the most promising candidate for electrochemical storage after lithium-ion batteries (LIBs) to meet the globally growing energy storage demand. Assessments to identify environmental hotspots and address them in further development at regular intervals are inevitable to ensure low environmental impact of SIBs in the future. However, the number of studies assessing the environmental impacts of SIBs is limited, and existing studies are mostly based on theoretical models and few limited sources. This study is one of the few to provide life cycle inventory data from actual production processes of SIBs, allowing for hotspot analysis of environmental impacts. A comparative life cycle assessment of two emerging SIB technologies is conducted based on primary laboratory data, focusing on the synthesis of the two cathode active materials (CAMs), sodium vanadium phosphate (NVP/C), and a Prussian white (PW). The results show that the impacts of NVP/C-based pouch cells are significantly higher than the PW-based cells in all impact categories due to lower gravimetric energy densities and higher CAM synthesis-related impacts. To ensure the correct order of magnitude a benchmark NMC-based LIB is assessed at the same laboratory, showing lower impacts than both SIBs, due to higher gravimetric energy densities.