Stress Evolution in Composite Silicon Electrodes during Lithiation/Delithiation
| Autor: | Sethuraman, Vijay A., Nguyen, Annam, Chon, Michael J., Nadimpalli, Siva P. V., Wang, Hailong, Abraham, Daniel P., Bower, Allan F., Shenoy, Vivek B., Guduru, Pradeep R. |
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| Rok vydání: | 2013 |
| Předmět: | |
| Zdroj: | Journal of The Electrochemical Society, 160 (4), A739-A746, 2013 |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1149/2.021306jes |
| Popis: | We report real-time average stress measurements on composite silicon electrodes made with two different binders [Carboxymethyl cellulose (CMC), and polyvinylidene fluoride (PVDF)] during electrochemical lithiation and delithiation. During galvanostatic lithiation at very slow rates, the stress in a CMC-based electrode becomes compressive and increases to 70 MPa, where it reaches a plateau and increases slowly thereafter with capacity. The PVDF-based electrode exhibits similar behavior, although with lower peak compressive stress of about 12 MPa. These initial experiments indicate that the stress evolution in a Si composite electrode depends strongly on the mechanical properties of the binder. Stress data obtained from a series of lithiation/delithiation cycles suggests plasticity induced irreversible shape changes in contacting Si particles, and as a result, the stress response of the system during any given lithiation/delithiation cycle depends on the cycling history of the electrode. While these results constitute the first in-situ stress measurements on composite Si electrodes during electrochemical cycling, the diagnostic technique described herein can be used to assess the mechanical response of a composite electrode made with other active material/binder combinations. Comment: 22 pages, 8 figures |
| Databáze: | arXiv |
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