Li-ion batteries are currently the preferred solution to store electrical energy. However, their safety is still a challenging issue. Since we are more and more moving from rechargeable battery packs working with water-based electrolytes to more powerful or more energy containing ones utilizing non aqueous electrolytes, risk profiles have changed abruptly from uncontrolled release of hydrogen during charging (e.g. in lead acid or Nickel Metal hydride type of batteries) to the so called and much more safety challenging thermal runaway process. Indeed, thermal runaway has been identified as the major concern in terms of Li-ion battery safety issues on its full value chain inducing significant thermal and chemical threats [1]. The phenomenon entails a cascade of stages initiated at material level and may be induced by various abuse conditions (abnormal disorders of thermal, mechanical or electrical nature). Progress in understanding this complex phenomenon, so far essentially achieved by experimentations at material and cell levels have opened the door to safer battery design or better safety management through various modeling techniques [2].

This paper deals with an innovative approach in such a contribution which consists in the development and validation of a physical and accurate model of Li-ion batteries electro-thermal behavior nearby thermal runaway conditions which includes sub-models reflecting ageing effect interaction. Therefore, enlarged application is targeted for such a model, depending on validation domain, since it is capable of analyzing the risk of failure induced by thermal runaway for applications to safety management expanded to new and aged batteries, or for safe “second life” use of Li-ion batteries.

 The presentation will describe the overall methodology considered (see fig.1), provide the set of electrochemical-thermal sub-models used, describe the experimental plans based on three series of Li-ion cells (see fig. 2) developed for i) adjusting requested thermal parameters in the sub-models and ii) for validation purposes and eventually present results obtained so far.

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References

[1] P. Ribière, S. Grugeon, M. Morcrette, S. Boyanov, S. Laruelle, G. Marlair, Energy Environ. Sci. 5 (2012) 5271.

[2] Sara Abada, Martin Petit, Amandine Lecocq², Guy Marlair, François Huet, Valérie Sauvant-Moynot, J. Power Sources, (2015), in press, http://dx.doi.org/10.1016/j.powersour.2015.11.100