Saved in:
| Main Authors: | , , , , , , , , |
|---|---|
| Format: | Preprint |
| Published: |
2025
|
| Subjects: | |
| Online Access: | https://arxiv.org/abs/2507.16561 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866912496784244736 |
|---|---|
| author | Ahmed, Shamail Rossi, Federico Huo, Hanyu Haust, Johannes Hueppe, Franziska Belz, Juergen Beyer, Andreas Janek, Juergen Volz, Kerstin |
| author_facet | Ahmed, Shamail Rossi, Federico Huo, Hanyu Haust, Johannes Hueppe, Franziska Belz, Juergen Beyer, Andreas Janek, Juergen Volz, Kerstin |
| contents | Silicon offers great promise as a potential anode active material and the optimum alternative to lithium metal in all-solid-state lithium-ion batteries. However, its practical application is limited by severe volume expansion (~300%) during lithiation, leading to cracking upon delithiation. In this study, we investigated the microstructural evolution of microcrystalline silicon electrodes in a solid-electrolyte-free environment using cryogenic scanning transmission electron microscopy (STEM) during electrochemical cycling. A controlled workflow prevents ambient exposure, and cryo-TEM ensures structural integrity. After the first lithiation, the electrode shows a heterogeneous mix of crystalline Li15Si4, various amorphous LixSi phases, and residual crystalline silicon. After delithiation, the structure becomes predominantly amorphous with thread-like features and minimal remaining crystallinity. By the 10th delithiation, the microstructure is more uniform, with thread-like regions mainly at grain boundaries. Our results reveal that starting from a crystalline phase, a stationary microstructure emerges in bulk silicon only after several cycles. Thus, to have a more controlled behavior of the electrode and minimize cracking, the starting material should be carefully chosen along with an optimized electrode architecture to help stabilize the microstructure throughout cycling. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2507_16561 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Microstructure of Silicon Anodes in Solid-State Batteries -- From Crystalline to Amorphous Ahmed, Shamail Rossi, Federico Huo, Hanyu Haust, Johannes Hueppe, Franziska Belz, Juergen Beyer, Andreas Janek, Juergen Volz, Kerstin Materials Science Silicon offers great promise as a potential anode active material and the optimum alternative to lithium metal in all-solid-state lithium-ion batteries. However, its practical application is limited by severe volume expansion (~300%) during lithiation, leading to cracking upon delithiation. In this study, we investigated the microstructural evolution of microcrystalline silicon electrodes in a solid-electrolyte-free environment using cryogenic scanning transmission electron microscopy (STEM) during electrochemical cycling. A controlled workflow prevents ambient exposure, and cryo-TEM ensures structural integrity. After the first lithiation, the electrode shows a heterogeneous mix of crystalline Li15Si4, various amorphous LixSi phases, and residual crystalline silicon. After delithiation, the structure becomes predominantly amorphous with thread-like features and minimal remaining crystallinity. By the 10th delithiation, the microstructure is more uniform, with thread-like regions mainly at grain boundaries. Our results reveal that starting from a crystalline phase, a stationary microstructure emerges in bulk silicon only after several cycles. Thus, to have a more controlled behavior of the electrode and minimize cracking, the starting material should be carefully chosen along with an optimized electrode architecture to help stabilize the microstructure throughout cycling. |
| title | Microstructure of Silicon Anodes in Solid-State Batteries -- From Crystalline to Amorphous |
| topic | Materials Science |
| url | https://arxiv.org/abs/2507.16561 |