Evolution of the 3D Microstructure of a Si-Based Electrode for Li-Ion Batteries Investigated by FIB/SEM Tomography

Aurélien Etiemble (1) , Alix Tranchot (1, 2) , Thierry Douillard (1) , Hassane Idrissi (1) , Éric Maire (1) , Lionel Roué (2)

1 MATEIS - Matériaux, ingénierie et science [Villeurbanne]
2 EMT-INRS - Énergie Matériaux Télécommunications - INRS

The evolution with cycling of the three-dimensional (3D) microstructure of a silicon/carbon/carboxymethylcellulose (Si/C/CMC) electrode for Li-ion batteries is investigated by combined focused ion beam (FIB) / scanning electron microscopy (SEM) tomography. Using appropriate image processing methods, a volume of 20 x 8 x 11 µm 3 is reconstructed in which the Si and pore phases are clearly identified. Their respective morphological characteristics (volume fraction, spatial distribution, size, connectivity, and tortuosity) are determined before and after 1, 10 and 100 cycles. The Si particles (37 vol.%, median size = 0.37 µm) and pores (57 vol.%, median size = 0.40 µm) are homogeneously distributed and fully connected in the pristine electrode. Major changes in the electrode morphology occur upon cycling due to electrode cracking and the growth of the solid electrolyte interface (SEI) layer. It also appears that the size and shape of the Si particles change upon cycling. They display a non-spherical, stringy morphology after 100 cycles with a median size of 0.14 µm.

Domaines: Matériaux

Aurélien Etiemble, Alix Tranchot, Thierry Douillard, Hassane Idrissi, Éric Maire, et al.. Evolution of the 3D Microstructure of a Si-Based Electrode for Li-Ion Batteries Investigated by FIB/SEM Tomography. Journal of The Electrochemical Society, 2016, 163 (8), pp.A1550-A1559. ⟨10.1149/2.0421608jes⟩. ⟨hal-03538469⟩