Properties of trifluoromethylated lithium borates for lithium-ion battery electrolytes
Lithium salts govern important characteristics of lithium-ion batteries, including their efficiency (ion conductivity), operating voltage (potential window), and thermal stability. Herein, a series of lithium borates (lithium difluoro(perfluoropinacolato)borate (PFP-F _2 ), lithium difluoro(2-hydrox...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2022-01-01
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| Series: | JPhys Energy |
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| Online Access: | https://doi.org/10.1088/2515-7655/ac9dbe |
| _version_ | 1827965026026127360 |
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| author | Mikihiro Takahashi Shoichi Tsujioka Wataru Kawabata Ryansu Sai Hiromori Tsutsumi Yu Katayama |
| author_facet | Mikihiro Takahashi Shoichi Tsujioka Wataru Kawabata Ryansu Sai Hiromori Tsutsumi Yu Katayama |
| author_sort | Mikihiro Takahashi |
| collection | DOAJ |
| description | Lithium salts govern important characteristics of lithium-ion batteries, including their efficiency (ion conductivity), operating voltage (potential window), and thermal stability. Herein, a series of lithium borates (lithium difluoro(perfluoropinacolato)borate (PFP-F _2 ), lithium difluoro(2-hydroxy-3,3,3,3ʹ,3ʹ,3ʹ-hexafluoroisobutirato)borate (HHIB-F _2 ), lithium (perfluoropinacolato)(oxalato)borate (PFP-Ox), lithium bis(2-hydroxy-3,3,3,3ʹ,3ʹ,3ʹ-hexafluoroisobutirato)borate (HHIB _2 ), and lithium (2-hydroxy-3,3,3,3ʹ,3ʹ,3ʹ-hexafluoroisobutirato)(oxalato)borate) containing CF _3 and C=O groups were developed as potential electrolytes for lithium-ion batteries. The proposed lithium borates were synthesized in good purity from lithium tetrafluoroborate and lithium difluoro(oxalato)borate using trimethylchlorosilane and three types of bidentate ligands in ethylmethylcarbonate. The applicability of the novel lithium borates as electrolytes for lithium-ion batteries was demonstrated based on thermal and electrochemical stability evaluations. In addition, lithium borates with >4 CF _3 groups (PFP-F _2 , PFP-Ox, and HHIB _2 ) exhibited outstanding stability against hydrolysis (water contamination). HHIB-F _2 showed the best ionic conductivity owing to the balanced incorporation of increased Li ^+ dissociation and mobility by introducing the CF _3 group and reducing the anion size. HHIB-F _2 and HHIB _2 -containing electrolytes showed better cycle performance than their conventional BF _4 counterparts. This study suggests that the new lithium borates, HHIB _2 , and HHIB-F _2 , are promising lithium salts for lithium-ion batteries, providing a new direction for the lithium salt molecular design. |
| first_indexed | 2024-04-09T17:26:28Z |
| format | Article |
| id | doaj.art-e5713fcdea2f461e8334cb408d954ad3 |
| institution | Directory Open Access Journal |
| issn | 2515-7655 |
| language | English |
| last_indexed | 2024-04-09T17:26:28Z |
| publishDate | 2022-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | JPhys Energy |
| spelling | doaj.art-e5713fcdea2f461e8334cb408d954ad32023-04-18T13:49:46ZengIOP PublishingJPhys Energy2515-76552022-01-015101400310.1088/2515-7655/ac9dbeProperties of trifluoromethylated lithium borates for lithium-ion battery electrolytesMikihiro Takahashi0Shoichi Tsujioka1Wataru Kawabata2Ryansu Sai3Hiromori Tsutsumi4Yu Katayama5https://orcid.org/0000-0002-7842-2938Central Glass Co., Ltd applied chemical research center , 5254-35 Okiube, Ube, Yamaguchi, 755-0001, JapanCentral Glass Co., Ltd applied chemical research center , 5254-35 Okiube, Ube, Yamaguchi, 755-0001, JapanCentral Glass Co., Ltd applied chemical research center , 5254-35 Okiube, Ube, Yamaguchi, 755-0001, JapanGraduate School of Sciences and Technology for Innovation, Yamaguchi University , 2-16-1 Tokiwadai, Ube, Yamaguchi 755-8611, JapanGraduate School of Sciences and Technology for Innovation, Yamaguchi University , 2-16-1 Tokiwadai, Ube, Yamaguchi 755-8611, JapanSANKEN (The Institute of Scientific and Industrial Research), Osaka University , Mihogaoka 8-1, Ibaraki, Osaka 567-0047, JapanLithium salts govern important characteristics of lithium-ion batteries, including their efficiency (ion conductivity), operating voltage (potential window), and thermal stability. Herein, a series of lithium borates (lithium difluoro(perfluoropinacolato)borate (PFP-F _2 ), lithium difluoro(2-hydroxy-3,3,3,3ʹ,3ʹ,3ʹ-hexafluoroisobutirato)borate (HHIB-F _2 ), lithium (perfluoropinacolato)(oxalato)borate (PFP-Ox), lithium bis(2-hydroxy-3,3,3,3ʹ,3ʹ,3ʹ-hexafluoroisobutirato)borate (HHIB _2 ), and lithium (2-hydroxy-3,3,3,3ʹ,3ʹ,3ʹ-hexafluoroisobutirato)(oxalato)borate) containing CF _3 and C=O groups were developed as potential electrolytes for lithium-ion batteries. The proposed lithium borates were synthesized in good purity from lithium tetrafluoroborate and lithium difluoro(oxalato)borate using trimethylchlorosilane and three types of bidentate ligands in ethylmethylcarbonate. The applicability of the novel lithium borates as electrolytes for lithium-ion batteries was demonstrated based on thermal and electrochemical stability evaluations. In addition, lithium borates with >4 CF _3 groups (PFP-F _2 , PFP-Ox, and HHIB _2 ) exhibited outstanding stability against hydrolysis (water contamination). HHIB-F _2 showed the best ionic conductivity owing to the balanced incorporation of increased Li ^+ dissociation and mobility by introducing the CF _3 group and reducing the anion size. HHIB-F _2 and HHIB _2 -containing electrolytes showed better cycle performance than their conventional BF _4 counterparts. This study suggests that the new lithium borates, HHIB _2 , and HHIB-F _2 , are promising lithium salts for lithium-ion batteries, providing a new direction for the lithium salt molecular design.https://doi.org/10.1088/2515-7655/ac9dbelithium borateslithium-ion batterieselectrolytelithium salt |
| spellingShingle | Mikihiro Takahashi Shoichi Tsujioka Wataru Kawabata Ryansu Sai Hiromori Tsutsumi Yu Katayama Properties of trifluoromethylated lithium borates for lithium-ion battery electrolytes JPhys Energy lithium borates lithium-ion batteries electrolyte lithium salt |
| title | Properties of trifluoromethylated lithium borates for lithium-ion battery electrolytes |
| title_full | Properties of trifluoromethylated lithium borates for lithium-ion battery electrolytes |
| title_fullStr | Properties of trifluoromethylated lithium borates for lithium-ion battery electrolytes |
| title_full_unstemmed | Properties of trifluoromethylated lithium borates for lithium-ion battery electrolytes |
| title_short | Properties of trifluoromethylated lithium borates for lithium-ion battery electrolytes |
| title_sort | properties of trifluoromethylated lithium borates for lithium ion battery electrolytes |
| topic | lithium borates lithium-ion batteries electrolyte lithium salt |
| url | https://doi.org/10.1088/2515-7655/ac9dbe |
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