Investigating the Fire Safety in Fluorine-free Sodium-ion Batteries

With the large expansion the battery field, performance is not the only key factor. Instead, the needs to be prioritized are safety, sustainability and cost. This means there is plenty of room for other technologies beyond commercial lithium-ion batteries, such as sodium-ion batteries. These are more environmentally friendly and cost-sensitive as they are made of more abundant materials. A combination of these technologies will speed up the electrification of the transport system, implementation of stationary storage, and, overall, transformation to a CO2-neutral society. While lithium-ion batteries have been substantially improved since their initial commercialization, a lot of research is still needed for sodium-ion batteries to be competitive while ensuring safety and sustainability.

This project aims to investigate the safety of next-generation batteries intended for large-scale energy storage.  As sodium-ion batteries are expected to be manufactured on a large scale, safety, both for the environment and people, is of utmost importance. A safety issue common to conventional lithium-ion batteries and sodium-ion batteries is the use of fluorinated electrolytes, which can release toxic and corrosive substances in the event of a fire and complicate the battery recycling process by corroding reactors and contaminating the components to be recycled. Therefore, alternative, fluorine-free electrolytes are necessary to move towards safer, less toxic and more environmentally friendly batteries and thus achieve a more sustainable energy system. While these arguments are relevant to all battery chemistries, they are particularly important for sodium-ion batteries and large-scale battery installations based on the extent of the planned production and installation. The project is a collaboration between Uppsala University, Altris AB, the Swedish Defence Research Agency and RISE, with the overall goal of developing and investigating the safety of a new fluorine-free electrolyte for sodium-ion batteries.