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The role of structural defects in commercial batteries revealed by X-ray tomography

Lithium-ion batteries (LIB) are the most important energy storage technique for electric vehicle applications. The manufacturing of commercial LIBs involves a number of highly intricate processes that could induce various structural and chemical defects. This work investigates the role of structural defects on battery functionality.

PRINCIPAL PUBLICATION AND AUTHORS

The role of structural defects in commercial lithium-ion batteries, G. Qian (a,b), F. Monaco (c), D. Meng (a), S-J. Lee (b), G. Zan (b), J. Li (b), D. Karpov (c), S. Gul (d), D. Vine (d), B. Stripe (d), J. Zhang (b,e), J-S. Lee (b), Z-F. Ma (a), W. Yun (d), P. Pianetta (b), X. Yu (f,g), L. Li (a,h), P. Cloetens (c), Y. Liu (b), Cell Rep. Phys. Sci. 2, 100554 (2021); https:/doi.org/10.1016/j.xcrp.2021.100554. (a) Department of Chemical Engineering, Shanghai Electrochemical Energy Device Research Center (SEED), School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Jiao Tong University (China) (b) SLAC National Accelerator Laboratory, California (USA) (c) ESRF (d) Sigray, California (USA) (e) Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Science (China) (f) Beijing Advanced Innovation Center for Materials Genome Engineering, Institute of Physics, Chinese Academy of Sciences (China) (g) Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences (China) (h) Shanghai Jiao Tong University Sichuan Research Institute (China)

REFERENCE

[1] G. Zan et al., J. Mater. Chem. A 9, 19886-19893 (2021).

A multiscale experiment on commercial 18650-type LIBs (Figure 147) that have failed quality control due to self- discharging effects used high-resolution tomography at beamline ID16A to elucidate the potential degradation mechanisms associated with the presence of cell defects, e.g., impurity particles. These metallic impurities are electrochemically active and could cause undesired redox heterogeneity and surface passivation, leading to increased electrochemical impedance and polarisation. Non-uniform active particle packing was also observed, which could lead to poor mechanical robustness. This work features a macro-to-nano zoom through the hierarchy of a defective commercial LIB [1], offering valuable insights for improving LIB manufacturing.

Fig. 147: a) 3D multiscale visualisation of the micromorphology of a commercial lithium-ion battery. b-c) Regions with impurity particles detected. d) Packing density map over different defective regions.