Numerical Prediction of Multiscale Electronic Conductivity of Lithium-Ion Battery Positive Electrodes

François Cadiou (1) , A. Etiemble (2) , T. Douillard (1) , François Willot (3) , O. Valentin (4) , Jean-Claude Badot (5) , Bernard Lestriez (6) , E. Maire (1)

1 MATEIS - Matériaux, ingénierie et science [Villeurbanne]
2 ECAM Lyon - ECAM Lyon
3 CMM - Centre de Morphologie Mathématique
4 Aurock
5 ENSCP - Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL
6 IMN - Institut des Matériaux Jean Rouxel

The electronic conductivity, at the multiscale, of lithium-ion positive composite electrodes based on LiNi_{1/3}Mn_{1/3}Co_{1/3}O_2 and/or carbon-coated LiFePO_4, carbon black and poly(vinylidene fluoride) mixture is modeled. The electrode microstructures are acquired numerically in 3D by X-ray tomography and FIB/SEM nanotomography and numerically segmented to perform electrostatic simulations using Fast Fourier Transform (FFT) method. Such simulations are easy and quick to perform because they are directly computed on the grid represented by the voxels in the 3D volumes. Numerical results are compared with experimental measurements of the multiscale electronic conductivity by broadband dielectric spectroscopy (BDS). A good prediction is realized for the bulk conductivities of the C/LiFePO_4 phase and the CB/PVdF mixture. The combination of X-ray and FIB/SEM tomography, FFT simulation method, and BDS is thus well adapted to understand the influence of the electrode composition and microstructure on its electronic conductivity.

Mots clés: Batteries - Lithium; Numerical simulation; Electrodes; Electrical conductivity

Domaines: Matériaux

François Cadiou, A. Etiemble, T. Douillard, François Willot, O. Valentin, et al.. Numerical Prediction of Multiscale Electronic Conductivity of Lithium-Ion Battery Positive Electrodes. Journal of The Electrochemical Society, 2019, 166 (8), pp.A1692-A1703. ⟨10.1149/2.1221908jes⟩. ⟨hal-02137415v2⟩