Kinetic Study of Lithiation-Induced Phase Transitions in Amorphous Germanium Thin Films
Mechanisms of the reversible lithiation of amorphous germanium thin films were studied using electrochemical and structural characterization techniques. Cyclic voltammograms (CV) exhibited major lithiation peaks and delithiation peaks, the latter of which turned out to be highly dependent on the lit...
| Main Authors: | , , |
|---|---|
| Other Authors: | |
| Format: | Article |
| Language: | English |
| Published: |
The Electrochemical Society
2020
|
| Online Access: | https://hdl.handle.net/1721.1/127253 |
| _version_ | 1811071530758569984 |
|---|---|
| author | Miao, Jinghui Wang, Baoming Thompson, Carl Vernette |
| author2 | Massachusetts Institute of Technology. Department of Materials Science and Engineering |
| author_facet | Massachusetts Institute of Technology. Department of Materials Science and Engineering Miao, Jinghui Wang, Baoming Thompson, Carl Vernette |
| author_sort | Miao, Jinghui |
| collection | MIT |
| description | Mechanisms of the reversible lithiation of amorphous germanium thin films were studied using electrochemical and structural characterization techniques. Cyclic voltammograms (CV) exhibited major lithiation peaks and delithiation peaks, the latter of which turned out to be highly dependent on the lithiation cutoff voltage and closely associated with the formation of the crystalline phase c-Li15Ge4. Through detailed analyses of CV and potentiostatic tests we demonstrate that the features of electrochemically induced phase transitions vary with lithiation voltage. A surprising finding is that two phase transitions occur simultaneously in the 0.29-0.14 V range. In this regime, three phases, two amorphous phases with different stoichiometries and the crystalline phase, can co-exist. The cycle-number dependence of formation of the crystalline phase as well as structural analyses suggest that crack formation may play an important role in reducing the kinetic barrier associated with crystallization. This study sheds new light on the kinetic constraints on lithiation of a-Ge and yields insight for electrode design and development of cycling schemes for optimized performance and cyclability. |
| first_indexed | 2024-09-23T08:52:39Z |
| format | Article |
| id | mit-1721.1/127253 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2024-09-23T08:52:39Z |
| publishDate | 2020 |
| publisher | The Electrochemical Society |
| record_format | dspace |
| spelling | mit-1721.1/1272532022-09-26T08:54:30Z Kinetic Study of Lithiation-Induced Phase Transitions in Amorphous Germanium Thin Films Miao, Jinghui Wang, Baoming Thompson, Carl Vernette Massachusetts Institute of Technology. Department of Materials Science and Engineering Mechanisms of the reversible lithiation of amorphous germanium thin films were studied using electrochemical and structural characterization techniques. Cyclic voltammograms (CV) exhibited major lithiation peaks and delithiation peaks, the latter of which turned out to be highly dependent on the lithiation cutoff voltage and closely associated with the formation of the crystalline phase c-Li15Ge4. Through detailed analyses of CV and potentiostatic tests we demonstrate that the features of electrochemically induced phase transitions vary with lithiation voltage. A surprising finding is that two phase transitions occur simultaneously in the 0.29-0.14 V range. In this regime, three phases, two amorphous phases with different stoichiometries and the crystalline phase, can co-exist. The cycle-number dependence of formation of the crystalline phase as well as structural analyses suggest that crack formation may play an important role in reducing the kinetic barrier associated with crystallization. This study sheds new light on the kinetic constraints on lithiation of a-Ge and yields insight for electrode design and development of cycling schemes for optimized performance and cyclability. 2020-09-14T15:27:39Z 2020-09-14T15:27:39Z 2020-07 2020-06 2020-09-11T15:18:22Z Article http://purl.org/eprint/type/JournalArticle 0013-4651 https://hdl.handle.net/1721.1/127253 Miao, Jinghui, Baoming Wang, and Carl V. Thompson. “Kinetic Study of Lithiation-Induced Phase Transitions in Amorphous Germanium Thin Films.” Journal of the Electrochemical Society, 167, 9 (July 2020): © 2020 The Author(s) en 10.1149/1945-7111/ab9eec Journal of the Electrochemical Society Creative Commons Attribution-NonCommercial-NoDerivs License http://creativecommons.org/licenses/by-nc-nd/4.0/ application/pdf The Electrochemical Society IOP Publishing |
| spellingShingle | Miao, Jinghui Wang, Baoming Thompson, Carl Vernette Kinetic Study of Lithiation-Induced Phase Transitions in Amorphous Germanium Thin Films |
| title | Kinetic Study of Lithiation-Induced Phase Transitions in Amorphous Germanium Thin Films |
| title_full | Kinetic Study of Lithiation-Induced Phase Transitions in Amorphous Germanium Thin Films |
| title_fullStr | Kinetic Study of Lithiation-Induced Phase Transitions in Amorphous Germanium Thin Films |
| title_full_unstemmed | Kinetic Study of Lithiation-Induced Phase Transitions in Amorphous Germanium Thin Films |
| title_short | Kinetic Study of Lithiation-Induced Phase Transitions in Amorphous Germanium Thin Films |
| title_sort | kinetic study of lithiation induced phase transitions in amorphous germanium thin films |
| url | https://hdl.handle.net/1721.1/127253 |
| work_keys_str_mv | AT miaojinghui kineticstudyoflithiationinducedphasetransitionsinamorphousgermaniumthinfilms AT wangbaoming kineticstudyoflithiationinducedphasetransitionsinamorphousgermaniumthinfilms AT thompsoncarlvernette kineticstudyoflithiationinducedphasetransitionsinamorphousgermaniumthinfilms |