A study of lithium ion batteries cycle aging by thermodynamics techniques
Lithium ion batteries (LiB) are cycled under a galvanostatic regime (∼C/2-rate) between 2.75 V and 4.2 V for up to 1000 cycles. After each completed 100 cycles, the discharge capacity, capacity loss, average discharge potential were determined under the same C/2 rate. Then cells undergo an additiona...
| Main Authors: | , |
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| Other Authors: | |
| Format: | Journal Article |
| Language: | English |
| Published: |
2014
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| Online Access: | https://hdl.handle.net/10356/103333 http://hdl.handle.net/10220/24463 |
| _version_ | 1811681984745832448 |
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| author | Maher, Kenza Yazami, Rachid |
| author2 | School of Materials Science and Engineering |
| author_facet | School of Materials Science and Engineering Maher, Kenza Yazami, Rachid |
| author_sort | Maher, Kenza |
| collection | NTU |
| description | Lithium ion batteries (LiB) are cycled under a galvanostatic regime (∼C/2-rate) between 2.75 V and 4.2 V for up to 1000 cycles. After each completed 100 cycles, the discharge capacity, capacity loss, average discharge potential were determined under the same C/2 rate. Then cells undergo an additional charge and discharge cycle at C/6 rate followed by a thermodynamics measurements test. This enables open-circuit potential (OCP), entropy (ΔS) and enthalpy (ΔH) data to be assessed.
It is found that with increasing cycle number, the entropy and enthalpy profiles show more significant changes than those observed in the discharge and the OCP curves especially at particular SOC and OCP values. These differences are attributed to the higher sensitivity of entropy and enthalpy state functions to changes in the crystal structure of the graphite anode and the lithiated cobalt oxide (LCO) induced by cycle aging compared to the free energy ΔG (OCP) alone. The thermodynamics data are supported by post-mortem X-ray diffractometry (XRD) and Raman scattering (RS) analyses on the electrode materials. The results show important LCO crystal structure degradation, whereas, surprisingly, the graphite anode remains almost unaffected by heavy cycling, if not improved. |
| first_indexed | 2024-10-01T03:49:38Z |
| format | Journal Article |
| id | ntu-10356/103333 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T03:49:38Z |
| publishDate | 2014 |
| record_format | dspace |
| spelling | ntu-10356/1033332021-01-20T02:44:20Z A study of lithium ion batteries cycle aging by thermodynamics techniques Maher, Kenza Yazami, Rachid School of Materials Science and Engineering Energy Research Institute @ NTU (ERI@N) DRNTU::Engineering::Materials::Energy materials Lithium ion batteries (LiB) are cycled under a galvanostatic regime (∼C/2-rate) between 2.75 V and 4.2 V for up to 1000 cycles. After each completed 100 cycles, the discharge capacity, capacity loss, average discharge potential were determined under the same C/2 rate. Then cells undergo an additional charge and discharge cycle at C/6 rate followed by a thermodynamics measurements test. This enables open-circuit potential (OCP), entropy (ΔS) and enthalpy (ΔH) data to be assessed. It is found that with increasing cycle number, the entropy and enthalpy profiles show more significant changes than those observed in the discharge and the OCP curves especially at particular SOC and OCP values. These differences are attributed to the higher sensitivity of entropy and enthalpy state functions to changes in the crystal structure of the graphite anode and the lithiated cobalt oxide (LCO) induced by cycle aging compared to the free energy ΔG (OCP) alone. The thermodynamics data are supported by post-mortem X-ray diffractometry (XRD) and Raman scattering (RS) analyses on the electrode materials. The results show important LCO crystal structure degradation, whereas, surprisingly, the graphite anode remains almost unaffected by heavy cycling, if not improved. 2014-12-15T06:47:38Z 2019-12-06T21:10:17Z 2014-12-15T06:47:38Z 2019-12-06T21:10:17Z 2013 2013 Journal Article Maher, K., & Yazami, R. (2014). A study of lithium ion batteries cycle aging by thermodynamics techniques. Journal of power sources, 247, 527-533. 0378-7753 https://hdl.handle.net/10356/103333 http://hdl.handle.net/10220/24463 10.1016/j.jpowsour.2013.08.053 en Journal of power sources © 2013 Elsevier B.V. |
| spellingShingle | DRNTU::Engineering::Materials::Energy materials Maher, Kenza Yazami, Rachid A study of lithium ion batteries cycle aging by thermodynamics techniques |
| title | A study of lithium ion batteries cycle aging by thermodynamics techniques |
| title_full | A study of lithium ion batteries cycle aging by thermodynamics techniques |
| title_fullStr | A study of lithium ion batteries cycle aging by thermodynamics techniques |
| title_full_unstemmed | A study of lithium ion batteries cycle aging by thermodynamics techniques |
| title_short | A study of lithium ion batteries cycle aging by thermodynamics techniques |
| title_sort | study of lithium ion batteries cycle aging by thermodynamics techniques |
| topic | DRNTU::Engineering::Materials::Energy materials |
| url | https://hdl.handle.net/10356/103333 http://hdl.handle.net/10220/24463 |
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