A mechanism of defect-enhanced phase transformation kinetics in lithium iron phosphate olivine
| dc.citation.articleNumber | 118 | |
| dc.citation.journalTitle | npj Computational Materials | |
| dc.citation.volumeNumber | 5 | |
| dc.contributor.author | Hong, Liang | |
| dc.contributor.author | Yang, Kaiqi | |
| dc.contributor.author | Tang, Ming | |
| dc.date.accessioned | 2020-02-14T16:39:55Z | |
| dc.date.available | 2020-02-14T16:39:55Z | |
| dc.date.issued | 2019 | |
| dc.description.abstract | Antisite defects are a type of point defect ubiquitously present in intercalation compounds for energy storage applications. While they are often considered a deleterious feature, here we elucidate a mechanism of antisite defects enhancing lithium intercalation kinetics in LiFePO4 by accelerating the FePO4 → LiFePO4 phase transformation. Although FeLi antisites block Li movement along the [010] migration channels in LiFePO4, phase-field modeling reveals that their ability to enhance Li diffusion in other directions significantly increases the active surface area for Li intercalation in the surface-reaction-limited kinetic regime, which results in order-of-magnitude improvement in the phase transformation rate compared to defect-free particles. Antisite defects also promote a more uniform reaction flux on (010) surface and prevent the formation of current hotspots under galvanostatic (dis)charging conditions. We analyze the scaling relation between the phase boundary speed, Li diffusivity and particle dimensions and derive the criteria for the co-optimization of defect content and particle geometry. A surprising prediction is that (100)-oriented LiFePO4 plates could potentially deliver better performance than (010)-oriented plates when the Li intercalation process is surface-reaction-limited. Our work suggests tailoring antisite defects as a general strategy to improve the rate performance of phase-changing battery compounds with strong diffusion anisotropy. | |
| dc.identifier.citation | Hong, Liang, Yang, Kaiqi and Tang, Ming. "A mechanism of defect-enhanced phase transformation kinetics in lithium iron phosphate olivine." <i>npj Computational Materials,</i> 5, (2019) Springer Nature: https://doi.org/10.1038/s41524-019-0255-3. | |
| dc.identifier.digital | s41524-019-0255-3 | |
| dc.identifier.doi | https://doi.org/10.1038/s41524-019-0255-3 | |
| dc.identifier.uri | https://hdl.handle.net/1911/108056 | |
| dc.language.iso | eng | |
| dc.publisher | Springer Nature | |
| dc.rights | This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. | |
| dc.rights.uri | https://creativecommons.org/licenses/by/4.0/ | |
| dc.title | A mechanism of defect-enhanced phase transformation kinetics in lithium iron phosphate olivine | |
| dc.type | Journal article | |
| dc.type.dcmi | Text | |
| dc.type.publication | publisher version |
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