Enhanced electrical conductivity and lithium ion diffusion rate of LiFePO4 by Fe site and P site doping
Lithium iron phosphate (LiFePO4) with an olivine-type structure has garnered great interest due to its electrochemical activity. It is considered one of the most promising cathode materials for lithium-ion batteries because of its high discharge platform, large theoretical capacity, and excellent cy...
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| Format: | Article |
| Language: | English |
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AIP Publishing LLC
2023-07-01
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| Series: | AIP Advances |
| Online Access: | http://dx.doi.org/10.1063/5.0159212 |
| _version_ | 1827878554687242240 |
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| author | L. X. Jiao Z. Q. Li Y. Z. Zhu Z. Wei Y. Liang X. L. Wang Y. Cui Z. H. Zhang M. He Bo Song |
| author_facet | L. X. Jiao Z. Q. Li Y. Z. Zhu Z. Wei Y. Liang X. L. Wang Y. Cui Z. H. Zhang M. He Bo Song |
| author_sort | L. X. Jiao |
| collection | DOAJ |
| description | Lithium iron phosphate (LiFePO4) with an olivine-type structure has garnered great interest due to its electrochemical activity. It is considered one of the most promising cathode materials for lithium-ion batteries because of its high discharge platform, large theoretical capacity, and excellent cycling performance and stability. However, the typical crystal structure of LiFePO4 restricts the formation of efficient electron conduction pathways and hampers the embedding and removal motion of lithium ions, resulting in low electron conductivity and a low ion diffusion rate. The experimental results show that element doping can reduce the activation energy of diffusion, increase the diffusion rate of lithium ions, improve the rate capability of lithium-ion batteries, and contribute to the improvement of its conductivity. In this work, the electronic structure and diffusion mechanism of a S/Co/Mn co-doped LiFePO4 system are systematically studied. The introduction of S, Co, and Mn atoms leads to the formation of impurity bands, resulting in a significant reduction in the bandgap from 3.593 eV to 0.190 eV, which is beneficial for improving the conductivity of LiFePO4. Moreover, the diffusion activation energy of lithium ions decreases from 0.73 eV to 0.34 eV, and the diffusion rate of lithium ions increases from 2.7 × 109 cm/s to 1.0 × 1016 cm/s. These results demonstrate that co-doping of S, Co, and Mn can effectively enhance the conductivity and diffusion rate of lithium ions in LiFePO4, providing a reliable reference for improving the electrochemical performance of lithium iron phosphate. |
| first_indexed | 2024-03-12T17:53:16Z |
| format | Article |
| id | doaj.art-1aeeafb9686e49988e5fac35f83e3123 |
| institution | Directory Open Access Journal |
| issn | 2158-3226 |
| language | English |
| last_indexed | 2024-03-12T17:53:16Z |
| publishDate | 2023-07-01 |
| publisher | AIP Publishing LLC |
| record_format | Article |
| series | AIP Advances |
| spelling | doaj.art-1aeeafb9686e49988e5fac35f83e31232023-08-02T20:06:09ZengAIP Publishing LLCAIP Advances2158-32262023-07-01137075306075306-710.1063/5.0159212Enhanced electrical conductivity and lithium ion diffusion rate of LiFePO4 by Fe site and P site dopingL. X. Jiao0Z. Q. Li1Y. Z. Zhu2Z. Wei3Y. Liang4X. L. Wang5Y. Cui6Z. H. Zhang7M. He8Bo Song9School of Materials Science and Engineering, Dalian Jiaotong University, Dalian 116028, People’s Republic of ChinaSchool of Materials Science and Engineering, Dalian Jiaotong University, Dalian 116028, People’s Republic of ChinaSchool of Materials Science and Engineering, Dalian Jiaotong University, Dalian 116028, People’s Republic of ChinaSchool of Materials Science and Engineering, Dalian Jiaotong University, Dalian 116028, People’s Republic of ChinaSchool of Materials Science and Engineering, Dalian Jiaotong University, Dalian 116028, People’s Republic of ChinaSchool of Materials Science and Engineering, Dalian Jiaotong University, Dalian 116028, People’s Republic of ChinaSchool of Materials Science and Engineering, Dalian Jiaotong University, Dalian 116028, People’s Republic of ChinaSchool of Materials Science and Engineering, Dalian Jiaotong University, Dalian 116028, People’s Republic of ChinaSchool of Physics and Materials Engineering, Dalian Minzu University, Dalian 116600, People’s Republic of ChinaAcademy of Fundamental and Interdisciplinary Sciences, Harbin Institute of Technology, Harbin 150080, People’s Republic of ChinaLithium iron phosphate (LiFePO4) with an olivine-type structure has garnered great interest due to its electrochemical activity. It is considered one of the most promising cathode materials for lithium-ion batteries because of its high discharge platform, large theoretical capacity, and excellent cycling performance and stability. However, the typical crystal structure of LiFePO4 restricts the formation of efficient electron conduction pathways and hampers the embedding and removal motion of lithium ions, resulting in low electron conductivity and a low ion diffusion rate. The experimental results show that element doping can reduce the activation energy of diffusion, increase the diffusion rate of lithium ions, improve the rate capability of lithium-ion batteries, and contribute to the improvement of its conductivity. In this work, the electronic structure and diffusion mechanism of a S/Co/Mn co-doped LiFePO4 system are systematically studied. The introduction of S, Co, and Mn atoms leads to the formation of impurity bands, resulting in a significant reduction in the bandgap from 3.593 eV to 0.190 eV, which is beneficial for improving the conductivity of LiFePO4. Moreover, the diffusion activation energy of lithium ions decreases from 0.73 eV to 0.34 eV, and the diffusion rate of lithium ions increases from 2.7 × 109 cm/s to 1.0 × 1016 cm/s. These results demonstrate that co-doping of S, Co, and Mn can effectively enhance the conductivity and diffusion rate of lithium ions in LiFePO4, providing a reliable reference for improving the electrochemical performance of lithium iron phosphate.http://dx.doi.org/10.1063/5.0159212 |
| spellingShingle | L. X. Jiao Z. Q. Li Y. Z. Zhu Z. Wei Y. Liang X. L. Wang Y. Cui Z. H. Zhang M. He Bo Song Enhanced electrical conductivity and lithium ion diffusion rate of LiFePO4 by Fe site and P site doping AIP Advances |
| title | Enhanced electrical conductivity and lithium ion diffusion rate of LiFePO4 by Fe site and P site doping |
| title_full | Enhanced electrical conductivity and lithium ion diffusion rate of LiFePO4 by Fe site and P site doping |
| title_fullStr | Enhanced electrical conductivity and lithium ion diffusion rate of LiFePO4 by Fe site and P site doping |
| title_full_unstemmed | Enhanced electrical conductivity and lithium ion diffusion rate of LiFePO4 by Fe site and P site doping |
| title_short | Enhanced electrical conductivity and lithium ion diffusion rate of LiFePO4 by Fe site and P site doping |
| title_sort | enhanced electrical conductivity and lithium ion diffusion rate of lifepo4 by fe site and p site doping |
| url | http://dx.doi.org/10.1063/5.0159212 |
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