Study of the trade-off in coupling multiple electrochemical models with a 3D thermal battery model

PEDRO MUÑOZ; DAVID LEVITAN; TOMÁS FALAGUERRA; RITA HUMANA; GABRIEL CORREA PERELMUTER

Congreso; 7th International Workshop on Lithium, Industrial Minerals and Energy; 2020

Li-ion batteries thermal models have been widely used and studied. This models consists in the coupling of an electrochemical (EC) model and a thermal model that work atdifferent scales. While the EC model describes the phenomena at the electrode level, the thermal model deals with the temperature distribution and heat evacuation at the fullcell scale.A full cell 3D model for a cylindrical battery would be extremely expensive from a computational point of view. Different methods are proposed to reduce the modelcomputational time and retain an accurate depiction of the real battery phenomena. The main simplifications applied are (i) modelling the jelly roll as one composite materialwith averaged properties and (ii) using an homogeneous heat generation profile for the 3D thermal model and an average temperature of the cell for the EC model. In mostcases, both simplifications are applied [1], that is, the heat generation from the EC model is averaged along the electrode length and this heat per unit of volume is consideredas a homogeneous source in the thermal model. Likewise, the temperature from the thermal model is averaged and passed on to the EC this model.For the first simplification (i), Capron et al. [2] conclude that it shows a better agreement with experimental data than a full model of the wounded material. Instead of using thesecond simplification (ii), but using the first (i), Kupper and Bessler [3], Tahir [4] and Trantel et al. [5] works use different strategies to model the heat generation inside thebattery using multiple EC models and one 3D or 2D axisymmetric thermal model, but a further discussion on the benefits and drawbacks of the models used is not given.In this work, a similar approach to that of Kupper and Bessler [3], and Tahir [4] is used to evaluate the temperature of a 26650 cylindrical battery using P2D EC models togenerate heat generation profiles for a 2D axisymmetric thermal model and evaluate the difference in heat generation, temperature distribution and computational time againsta previously published model [6].