A combination of X-Ray tomography and carbon binder modeling: Reconstructing the three phases of LiCoO2 Li-Ion battery cathodes

27.01.2014

Zielke L, Hutzenlaub T, Wheeler DR, Manke I, Arlt T, Paust N, Zengerle R, Thiele S

Advanced Energy Materials 2014,4(8): 1614-6840

Advanced Energy Materials                online article

X-ray tomography allows the active-material domain (LiCoO 2 ) of Li-ion battery cathodes to be imaged, but it is unable to resolve the carbon-binder domain (CBD). Here, a new method for creating a complete 3D representation (virtual design) of all three phases of a cathode is provided; this includes the active-material domain, the CBD, and the electrolyte-fi lled pore space. It combines X-ray tomographic data of active material with a statistically modeled CBD. Two different statistical CBD morphology models are compared as examples: i) a random cluster model representing a standard mixture of carbon black and polyvenylidene fl uoride (PVDF) and ii) a fi ber model. The transport parameters are compared in a charged and a discharged cathode. The results demonstrate that the CBD content and morphology changes the ionic and electronic transport parameters dramatically and thus cannot be neglected.