Recently deployed on a commercial scale, the Na-ion battery technology demonstrates excellent behaviour during medium or long-term storage at zero voltage. This characteristic offers numerous safety advantages during the transport, assembly and storage of cells and modules, as well as during emergency shutdowns in the event of external issues. But are there no consequences for battery performance?
This research project aims to study and better understand the electrochemical mechanisms at play when the potential difference across the terminals is maintained at 0 V.
Initially, advanced dynamic characterisation techniques will be used to analyse and compare the electrochemical, thermal and mechanical properties of battery materials. The results will enrich calendar and cycling ageing models at the cell scale, thereby improving their accuracy and reliability. Subsequently, tests will be conducted on mini-battery modules assembled in various electrical architectures to study cell behaviour during cycling and ageing, particularly in response to the application of negative voltage. Specific battery management system (BMS) solutions could then be proposed to address these issues.
The scientific approach will involve implementing advanced characterisation and instrumentation techniques, conducting ageing and safety tests to identify mechanisms, and developing ageing models. This approach will draw on the expertise and testing facilities of CEA-Liten at the Bourget du Lac site in Savoie.