Three-Dimensional Reconstruction of a LiCoO2 Li-Ion Battery Cathode

Abstract

Experimental To obtain the electrode material used in this work, a new VARTA LIC 18650 WC lithium-ion battery was unsealed and dismantled. After evaporation of the electrolyte, a piece was extracted from the cathodeandpreparedforFIB/SEMbysputteringaplatinumlayeronto the surface of the sample to gain a more planar area as a starting point for the FIB. Additionally, two reference lines, one orthogonal and the other with an angle of 48.2 ◦ in relation to the cutting plane, were imprinted into the platinum layer, providing a method independent of surface skew or irregularities to determine slice thickness (Fig. 1). With the help of an FEI Quanta three-dimensional dual-beam FIBSEM at Fraunhofer IZM, Berlin, a cavity was cut into the sample as a starting point and subsequently one side of the cuboid was ablated slice by slice, while the SEM, with an angle of 38 ◦ relative to the sample surface, generated one image per slice.