“Electrochemical testing is crucial, as the performance and safety of the final devices are validated in comparison to commercial ones.”

INTERVIEW WITH CARLOTTA FRANCIA, ASSOCIATE PROFESSOR AT POLITECNICO DI TORINO  

How will all these activities and methods applied at NEXTCELL provide the market with state-of-the-art technology for battery durability and safety? What are the main activities performed for electrochemical characterisation and thermal, ageing and safety tests?

In NEXTCELL, the partners are developing gelified innovative materials and processes with the aim of maximising the Li-ion battery performance and its sustainability by reducing energy consumption and avoiding the use of toxic organic solvents. In this framework, the electrochemical testing is a crucial unit of the work, as the performance and safety of final devices are validated in comparison to commercial ones.

The validation of the results starts from small laboratory cells, up to devices of marketable size. Moreover, a detailed understanding of the aging mechanisms is important for any application of Li ion batteries but it is critical for automotive applications, in which the batteries are stressed to a large extent and reliable performances must be ensured in any operative and climate condition.

The gelified cell proposed in NEXTCELL has the potential to be safer than the state-of-the-art Li-ion cell. For this purpose, abusive and aging tests associated to thermal characterisation are performed on individual cell components and on small pouch cells to validate this concept. The performed electrical safety tests involving overcharge, overdischarge and short circuit tests, represent real abuse scenarios and are oriented to established standards. Information on thermal cell characteristic and heat distribution obtained by accelerated rate calorimeter analysis generate new knowledge about the degradation mechanisms of the individual cell components under real operating condition.

In relation to cell balancing, it is indeed a delicate task, and carrying out optimal balancing requires a good evaluation of the capacities of the single electrodes in the half-cell. This allows tuning the cathodes charge to meet the requirements for full cells application.