Abstract
Since the commercialization of Lithium-Ion Battery (LIB) by Sony Inc. in 1991 until today, recurrent incidents involving LIBs have been reported worldwide. During these incidents, the most energetic catastrophic failure of a LIB system is the thermal runaway event. With the emergence of highly reactive Ni-rich LIBs in the market, battery safety is becoming even more critical because these newly introduced LIBs present such high energy density which could lead to more catastrophic events subsequent to the thermal runaway. Therefore, this thesis aims to go deeper into the understanding and modelling of this complex phenomenon at cell scale, taking into account the influence of novel highly reactive technologies and the influence of state of charge (SOC) and aging, in order to understand what the key factors are towards inherently safer design and operation of LIBs. Thanks to the synergism offered by combined experimental and modelling studies of this thesis, knowledge in terms of initiation and evolution of the thermal runaway of Ni-rich Li-ion batteries has been enriched. The modelling study leads to the development of a 3D extended thermal runaway model to predict the behaviours of different Li-ion batteries nearby and during thermal runaway. The experimental study investigates the thermal runaway of LIBs and provides suitable databases for the predictive model calibration and validation. The developed model can be used as a simulation tool to explore more scenarios of cells undergoing thermal runaway in specified conditions for which adequate parameterization can be defined in relation with underpinning physics. This contributes to the future Li-ion battery safety management system in depth