- Wang, XL
- An, K
- Cai, L
- Feng, Z
- Nagler, SE
- Daniel, C
- Rhodes, KJ
- Stoica, AD
- Skorpenske, HD
- Liang, C
- Zhang, W
- Kim, J
- Qi, Y
- Harris, SJ
- et al.
We report an in-situ neutron diffraction study of a large format pouch battery cell. The succession of Li-Graphite intercalation phases was fully captured under an 1C charge-discharge condition (i.e., charge to full capacity in 1 hour). However, the lithiation and dilithiation pathways are distinctively different and, unlike in slowing charging experiments with which the Li-Graphite phase diagram was established, no LiC 24 phase was found during charge at 1C rate. Approximately 75 mol. % of the graphite converts to LiC6at full charge, and a lattice dilation as large as 4% was observed during a charge-discharge cycle. Our work demonstrates the potential of in-situ, time and spatially resolved neutron diffraction study of the dynamic chemical and structural changes in real-world batteries under realistic cycling conditions, which should provide microscopic insights on degradation and the important role of diffusion kinetics in energy storage materials.