Ridder, A.; Prifling, B.; Hilger, A.; Osenberg, M.; Weber, M.; Manke, I.; Birke, K.P.; Schmidt, V.: Quantitative analysis of cyclic aging of lithium-ion batteries using synchrotron tomography and electrochemical impedance spectroscopy. Electrochimica Acta 444 (2023), p. 142003/1-11
10.1016/j.electacta.2023.142003
Open Access Version
Abstract:
The highly complex aging mechanisms of lithium-ion batteries are still not sufficiently well understood. In the present paper, we characterize cyclically aged cells by means of a statistical 3D microstructure analysis and electrochemical properties. More precisely, synchrotron tomography is used to capture the morphology of lithium-ion battery cathodes with a state of health of 100%, 90%, 80%, 60% and 40%, cyclically aged with two different C-rates (0.5C and 1C). The three phases, namely active material, pores and the carbon-binder domain, have been reconstructed from 3D grayscale images by a -means clustering approach. Moreover, individual active particles are segmented by combining the concept of morphological reconstruction with the watershed algorithm. The processed image data allows to quantitatively characterize the 3D microstructure by phase-based and particle-based characteristics, where a special focus is put on local heterogeneity, which will be described by locally computed descriptors. In addition, electrochemical data and electrochemical impedance spectroscopy are used to characterize the cyclically aged cells. Furthermore, we correlate these results with the detected structural changes. To the best of our knowledge, this is the most extensive data set of cyclically aged lithium-ion cells including electrochemical data as well as 3D structures.