In-situ X-ray tomographic imaging study of gas and structural evolution in a commercial Li-ion pouch cell
In-situ X-ray tomographic imaging study of gas and structural evolution in a commercial Li-ion pouch cell
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DOI：
10.1016/j.jpowsour.2021.230818
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发表时间：
2022-02
影响因子：
9.2
通讯作者：
W. Du;R. Owen;A. Jnawali;T. Neville;F. Iacoviello;Zhenyu Zhang;Sébastien Liatard;D. Brett;P. Shearing
中科院分区：
文献类型：
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作者：
W. Du;R. Owen;A. Jnawali;T. Neville;F. Iacoviello;Zhenyu Zhang;Sébastien Liatard;D. Brett;P. Shearing
锂离子电池（LIB）内的气体生成会导致电阻增加，从而缩短其循环寿命。通过内部气体逸出的灾难性故障的可能性可作为电池尺寸和容量的函数而增加。然而，在细胞水平上的气体析出的原位研究是非常有限的，由于数量有限的技术，可以有效地探测这一点。因此，我们第一次采用高能X射线断层扫描技术来非破坏性地观察400 mAh商用锂离子软包电池的结构演变（气体和电极）与循环次数的关系。在4D（3D +时间）中观察到气体团聚导致细胞在不同区域变形，随后的定量包括体积分数、表面积和厚度显示了不均匀的气体分布，揭示了涉及气体聚结的降解机制。该研究展示了使用基于实验室的X射线通过原位跟踪厚度来研究电池退化和监测健康状态（SOH）的可行案例，为设计更安全的软包电池提供了实用指导。
Gas generation within Li-ion batteries (LIB) can lead to an increase in resistance, thereby, reducing their cycle lifetime. The chance of catastrophic failure via internal gas evolution may increase as a function of cell size and capacity. However, in-situ studies of gas evolution at the cell level are very limited due to limited number of techniques that can effectively probe this. Hence, for the first time, we employed high-energy X-ray tomography to non-destructively observe the structural evolution (gas and electrodes) as a function of cycle numbers for a 400 mAh commercial Li-ion pouch cell. Gas agglomeration led to cell deformation in different areas were observed in 4D (3D + time), the subsequent quantification including the volume fraction, surface area and thickness showed a heterogeneous gas distribution, revealing the degradation mechanism involving the coalescence of gas. This study demonstrates a feasible case of the use of lab-based X-ray to investigate the cell degradation and monitor state of health (SOH) by tracking the thickness in-situ, providing practical guidance for designing safer pouch cells.