CN116799306A - Electrolyte containing thiophene additive and lithium ion battery using electrolyte - Google Patents
Electrolyte containing thiophene additive and lithium ion battery using electrolyte Download PDFInfo
- Publication number
- CN116799306A CN116799306A CN202310915551.XA CN202310915551A CN116799306A CN 116799306 A CN116799306 A CN 116799306A CN 202310915551 A CN202310915551 A CN 202310915551A CN 116799306 A CN116799306 A CN 116799306A
- Authority
- CN
- China
- Prior art keywords
- electrolyte
- lithium
- thiophene
- additive
- lithium ion
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 title claims abstract description 74
- 229910001416 lithium ion Inorganic materials 0.000 title claims abstract description 74
- YTPLMLYBLZKORZ-UHFFFAOYSA-N Thiophene Chemical compound C=1C=CSC=1 YTPLMLYBLZKORZ-UHFFFAOYSA-N 0.000 title claims abstract description 55
- 239000003792 electrolyte Substances 0.000 title claims abstract description 54
- 229930192474 thiophene Natural products 0.000 title claims abstract description 33
- 239000000654 additive Substances 0.000 title claims abstract description 30
- 230000000996 additive effect Effects 0.000 title claims description 20
- KMTRUDSVKNLOMY-UHFFFAOYSA-N Ethylene carbonate Chemical compound O=C1OCCO1 KMTRUDSVKNLOMY-UHFFFAOYSA-N 0.000 claims abstract description 21
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 15
- 229910003002 lithium salt Inorganic materials 0.000 claims abstract description 9
- 159000000002 lithium salts Chemical class 0.000 claims abstract description 9
- 239000005486 organic electrolyte Substances 0.000 claims abstract description 9
- 239000002904 solvent Substances 0.000 claims abstract description 9
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims abstract description 8
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 6
- 125000001183 hydrocarbyl group Chemical group 0.000 claims abstract description 6
- 229910052739 hydrogen Inorganic materials 0.000 claims abstract description 5
- 239000001257 hydrogen Substances 0.000 claims abstract description 5
- 229910052757 nitrogen Inorganic materials 0.000 claims abstract description 4
- 229910052736 halogen Inorganic materials 0.000 claims abstract description 3
- 150000002367 halogens Chemical class 0.000 claims abstract description 3
- 150000002431 hydrogen Chemical class 0.000 claims abstract description 3
- -1 thiophene compound Chemical class 0.000 claims description 27
- FKRCODPIKNYEAC-UHFFFAOYSA-N ethyl propionate Chemical compound CCOC(=O)CC FKRCODPIKNYEAC-UHFFFAOYSA-N 0.000 claims description 10
- 229910052744 lithium Inorganic materials 0.000 claims description 9
- VAYTZRYEBVHVLE-UHFFFAOYSA-N 1,3-dioxol-2-one Chemical compound O=C1OC=CO1 VAYTZRYEBVHVLE-UHFFFAOYSA-N 0.000 claims description 8
- 239000013538 functional additive Substances 0.000 claims description 8
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 claims description 7
- SBLRHMKNNHXPHG-UHFFFAOYSA-N 4-fluoro-1,3-dioxolan-2-one Chemical compound FC1COC(=O)O1 SBLRHMKNNHXPHG-UHFFFAOYSA-N 0.000 claims description 6
- OIFBSDVPJOWBCH-UHFFFAOYSA-N Diethyl carbonate Chemical compound CCOC(=O)OCC OIFBSDVPJOWBCH-UHFFFAOYSA-N 0.000 claims description 5
- 239000007773 negative electrode material Substances 0.000 claims description 5
- RUOJZAUFBMNUDX-UHFFFAOYSA-N propylene carbonate Chemical compound CC1COC(=O)O1 RUOJZAUFBMNUDX-UHFFFAOYSA-N 0.000 claims description 5
- 239000000463 material Substances 0.000 claims description 4
- 239000000203 mixture Substances 0.000 claims description 4
- HNAGHMKIPMKKBB-UHFFFAOYSA-N 1-benzylpyrrolidine-3-carboxamide Chemical compound C1C(C(=O)N)CCN1CC1=CC=CC=C1 HNAGHMKIPMKKBB-UHFFFAOYSA-N 0.000 claims description 3
- 229910013716 LiNi Inorganic materials 0.000 claims description 3
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 3
- 229910052782 aluminium Inorganic materials 0.000 claims description 3
- OBNCKNCVKJNDBV-UHFFFAOYSA-N butanoic acid ethyl ester Natural products CCCC(=O)OCC OBNCKNCVKJNDBV-UHFFFAOYSA-N 0.000 claims description 3
- CXULZQWIHKYPTP-UHFFFAOYSA-N cobalt(2+) manganese(2+) nickel(2+) oxygen(2-) Chemical compound [O--].[O--].[O--].[Mn++].[Co++].[Ni++] CXULZQWIHKYPTP-UHFFFAOYSA-N 0.000 claims description 3
- 150000001875 compounds Chemical class 0.000 claims description 3
- JBTWLSYIZRCDFO-UHFFFAOYSA-N ethyl methyl carbonate Chemical compound CCOC(=O)OC JBTWLSYIZRCDFO-UHFFFAOYSA-N 0.000 claims description 3
- MHCFAGZWMAWTNR-UHFFFAOYSA-M lithium perchlorate Chemical compound [Li+].[O-]Cl(=O)(=O)=O MHCFAGZWMAWTNR-UHFFFAOYSA-M 0.000 claims description 3
- 229910001486 lithium perchlorate Inorganic materials 0.000 claims description 3
- IGILRSKEFZLPKG-UHFFFAOYSA-M lithium;difluorophosphinate Chemical compound [Li+].[O-]P(F)(F)=O IGILRSKEFZLPKG-UHFFFAOYSA-M 0.000 claims description 3
- 239000011572 manganese Substances 0.000 claims description 3
- 239000010703 silicon Substances 0.000 claims description 3
- 229910052710 silicon Inorganic materials 0.000 claims description 3
- ZPFAVCIQZKRBGF-UHFFFAOYSA-N 1,3,2-dioxathiolane 2,2-dioxide Chemical compound O=S1(=O)OCCO1 ZPFAVCIQZKRBGF-UHFFFAOYSA-N 0.000 claims description 2
- WDXYVJKNSMILOQ-UHFFFAOYSA-N 1,3,2-dioxathiolane 2-oxide Chemical compound O=S1OCCO1 WDXYVJKNSMILOQ-UHFFFAOYSA-N 0.000 claims description 2
- FSSPGSAQUIYDCN-UHFFFAOYSA-N 1,3-Propane sultone Chemical compound O=S1(=O)CCCO1 FSSPGSAQUIYDCN-UHFFFAOYSA-N 0.000 claims description 2
- UHOPWFKONJYLCF-UHFFFAOYSA-N 2-(2-sulfanylethyl)isoindole-1,3-dione Chemical compound C1=CC=C2C(=O)N(CCS)C(=O)C2=C1 UHOPWFKONJYLCF-UHFFFAOYSA-N 0.000 claims description 2
- BTBUEUYNUDRHOZ-UHFFFAOYSA-N Borate Chemical compound [O-]B([O-])[O-] BTBUEUYNUDRHOZ-UHFFFAOYSA-N 0.000 claims description 2
- DKPFZGUDAPQIHT-UHFFFAOYSA-N Butyl acetate Natural products CCCCOC(C)=O DKPFZGUDAPQIHT-UHFFFAOYSA-N 0.000 claims description 2
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 2
- 229910019142 PO4 Inorganic materials 0.000 claims description 2
- HMDDXIMCDZRSNE-UHFFFAOYSA-N [C].[Si] Chemical compound [C].[Si] HMDDXIMCDZRSNE-UHFFFAOYSA-N 0.000 claims description 2
- IEJIGPNLZYLLBP-UHFFFAOYSA-N dimethyl carbonate Chemical compound COC(=O)OC IEJIGPNLZYLLBP-UHFFFAOYSA-N 0.000 claims description 2
- FUZZWVXGSFPDMH-UHFFFAOYSA-N hexanoic acid Chemical compound CCCCCC(O)=O FUZZWVXGSFPDMH-UHFFFAOYSA-N 0.000 claims description 2
- DEUISMFZZMAAOJ-UHFFFAOYSA-N lithium dihydrogen borate oxalic acid Chemical compound B([O-])(O)O.C(C(=O)O)(=O)O.C(C(=O)O)(=O)O.[Li+] DEUISMFZZMAAOJ-UHFFFAOYSA-N 0.000 claims description 2
- 229910001496 lithium tetrafluoroborate Inorganic materials 0.000 claims description 2
- OWNSEPXOQWKTKG-UHFFFAOYSA-M lithium;methanesulfonate Chemical compound [Li+].CS([O-])(=O)=O OWNSEPXOQWKTKG-UHFFFAOYSA-M 0.000 claims description 2
- MCVFFRWZNYZUIJ-UHFFFAOYSA-M lithium;trifluoromethanesulfonate Chemical compound [Li+].[O-]S(=O)(=O)C(F)(F)F MCVFFRWZNYZUIJ-UHFFFAOYSA-M 0.000 claims description 2
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 claims description 2
- 239000010452 phosphate Substances 0.000 claims description 2
- QXZUUHYBWMWJHK-UHFFFAOYSA-N [Co].[Ni] Chemical compound [Co].[Ni] QXZUUHYBWMWJHK-UHFFFAOYSA-N 0.000 claims 1
- UHHPUKUEMKPCII-UHFFFAOYSA-N ethyl fluoromethyl carbonate Chemical compound CCOC(=O)OCF UHHPUKUEMKPCII-UHFFFAOYSA-N 0.000 claims 1
- 239000007789 gas Substances 0.000 abstract description 16
- 238000004519 manufacturing process Methods 0.000 abstract description 15
- 150000003577 thiophenes Chemical class 0.000 abstract description 5
- 238000003860 storage Methods 0.000 description 18
- 238000000034 method Methods 0.000 description 12
- 230000014759 maintenance of location Effects 0.000 description 8
- 229910002804 graphite Inorganic materials 0.000 description 7
- 239000010439 graphite Substances 0.000 description 7
- 230000005540 biological transmission Effects 0.000 description 6
- 230000015572 biosynthetic process Effects 0.000 description 6
- 230000000052 comparative effect Effects 0.000 description 6
- 125000000472 sulfonyl group Chemical group *S(*)(=O)=O 0.000 description 6
- 239000004698 Polyethylene Substances 0.000 description 5
- 238000002156 mixing Methods 0.000 description 5
- 229920000573 polyethylene Polymers 0.000 description 5
- 239000004743 Polypropylene Substances 0.000 description 4
- 238000011056 performance test Methods 0.000 description 4
- 238000002360 preparation method Methods 0.000 description 4
- 238000012360 testing method Methods 0.000 description 4
- 238000007599 discharging Methods 0.000 description 3
- 238000001035 drying Methods 0.000 description 3
- 230000002687 intercalation Effects 0.000 description 3
- 238000009830 intercalation Methods 0.000 description 3
- 239000011259 mixed solution Substances 0.000 description 3
- 229910052760 oxygen Inorganic materials 0.000 description 3
- 229920001155 polypropylene Polymers 0.000 description 3
- 150000003457 sulfones Chemical class 0.000 description 3
- 229910052717 sulfur Inorganic materials 0.000 description 3
- 239000000853 adhesive Substances 0.000 description 2
- 230000001070 adhesive effect Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 239000002041 carbon nanotube Substances 0.000 description 2
- 229910021393 carbon nanotube Inorganic materials 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 239000006258 conductive agent Substances 0.000 description 2
- 239000011267 electrode slurry Substances 0.000 description 2
- 230000002349 favourable effect Effects 0.000 description 2
- 230000008014 freezing Effects 0.000 description 2
- 238000007710 freezing Methods 0.000 description 2
- 150000002430 hydrocarbons Chemical group 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 238000011084 recovery Methods 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 229920003048 styrene butadiene rubber Polymers 0.000 description 2
- GEWWCWZGHNIUBW-UHFFFAOYSA-N 1-(4-nitrophenyl)propan-2-one Chemical compound CC(=O)CC1=CC=C([N+]([O-])=O)C=C1 GEWWCWZGHNIUBW-UHFFFAOYSA-N 0.000 description 1
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 1
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 description 1
- 229910013075 LiBF Inorganic materials 0.000 description 1
- 229910013870 LiPF 6 Inorganic materials 0.000 description 1
- 239000002033 PVDF binder Substances 0.000 description 1
- 239000002174 Styrene-butadiene Substances 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 229910021383 artificial graphite Inorganic materials 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 239000011889 copper foil Substances 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 239000000839 emulsion Substances 0.000 description 1
- 229910052731 fluorine Inorganic materials 0.000 description 1
- 239000011737 fluorine Substances 0.000 description 1
- 239000011888 foil Substances 0.000 description 1
- 238000003475 lamination Methods 0.000 description 1
- 230000003446 memory effect Effects 0.000 description 1
- 239000011268 mixed slurry Substances 0.000 description 1
- 239000012046 mixed solvent Substances 0.000 description 1
- 238000004806 packaging method and process Methods 0.000 description 1
- 238000002161 passivation Methods 0.000 description 1
- 229920002981 polyvinylidene fluoride Polymers 0.000 description 1
- 239000007774 positive electrode material Substances 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 239000002002 slurry Substances 0.000 description 1
- 239000007784 solid electrolyte Substances 0.000 description 1
- 229940124530 sulfonamide Drugs 0.000 description 1
- 239000002562 thickening agent Substances 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 238000009966 trimming Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
- H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
- H01M10/0566—Liquid materials
- H01M10/0567—Liquid materials characterised by the additives
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Physics & Mathematics (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Inorganic Chemistry (AREA)
- Materials Engineering (AREA)
- Secondary Cells (AREA)
Abstract
The invention discloses an electrolyte containing thiophene additives and a lithium ion battery using the electrolyte, wherein the electrolyte comprises an organic electrolyte solvent, lithium salt and additives, the organic electrolyte solvent comprises ethylene carbonate, the additives comprise thiophene compounds, and the structure of the thiophene compounds is shown as formula 1:wherein X, Y are each independently selected from nitrogen or carbon, R 1 ～R 10 Each independently selected from hydrogen, halogen, C 1 ‑C 6 C is a hydrocarbon group of (C) 1 ‑C 6 Halogen-substituted hydrocarbyl, C 1 ‑C 6 Alkoxy or C of (2) 1 ‑C 6 And m and n are each independently selected from 0 or 1, and m and n are not both 0. The electrolyte of the invention can improve the high temperature of the lithium ion batteryStorage, high temperature cycle performance and low temperature performance, and also can inhibit high temperature cycle gas production.
Description
Technical Field
The invention belongs to the technical field of lithium ion batteries, and particularly relates to an electrolyte containing a thiophene additive and a lithium ion battery using the electrolyte.
Background
Compared with other secondary batteries, the lithium ion battery has the advantages of high voltage, high energy density, long service life, small self discharge, no memory effect and the like, and the application range of the lithium ion battery is wider and wider. Lithium ion batteries are also becoming a major angle in applications where the electrical performance, reliability, and safety requirements of the batteries are high, such as in the aerospace and military fields. The electrolyte reacts on the surface of the negative electrode to form a passivation film, which is called a solid electrolyte interface film (SEI), and the SEI film formed in the initial charging process not only prevents the electrolyte from further decomposing on the surface of the carbon negative electrode, but also plays a role of lithium ion tunnel and only allows lithium ions to pass through, so that the SEI film determines the performance of the lithium ion battery.
In recent years, many related researches are made in industry to improve various performances of lithium ion batteries, for example, a lithium ion battery electrolyte containing thiophene is disclosed in chinese patent document CN111162318A, and the thiophene compound has a lower oxidation potential, i.e. has a better electropolymerization characteristic, and can significantly improve cycle and low temperature characteristics of the battery, but because an interface formed by thiophene has a good conductive property, self-discharge of the battery is easily caused, which is unfavorable for storage performance of the lithium ion battery. As disclosed in chinese patent document CN102035022a, a sulfone-containing lithium ion battery electrolyte is reported, and the sulfone-containing lithium ion battery electrolyte has a higher oxidation potential, so that decomposition of the electrolyte on the surface of a high-voltage positive electrode material in the charging process can be reduced, but the sulfone-containing lithium ion battery electrolyte is easy to co-intercalate with lithium, so that a graphite layer is peeled off and falls off, which is unfavorable for the cycle characteristics of the battery.
Therefore, there is a need for an electrolyte containing thiophene additives and a lithium ion battery using the same to solve the problems of the prior art.
Disclosure of Invention
The invention aims to provide an electrolyte containing thiophene additives, which can improve the high-temperature storage, high-temperature cycle performance and low-temperature performance of a lithium ion battery and can inhibit high-temperature cycle gas production.
The invention also aims to provide a lithium ion battery using the electrolyte, which has better high-temperature storage, high-temperature cycle performance and low-temperature performance and can inhibit high-temperature cycle gas production.
In order to achieve the above purpose, the invention provides an electrolyte containing thiophene additives, which comprises an organic electrolyte solvent, lithium salt and additives, wherein the organic electrolyte solvent comprises Ethylene Carbonate (EC), the additives comprise thiophene compounds, and the structure of the thiophene compounds is shown as formula 1:
wherein X, Y are each independently selected from nitrogen or carbon, R 1 ～R 10 Each independently selected from hydrogen, halogen, C 1 -C 6 C is a hydrocarbon group of (C) 1 -C 6 Halogen-substituted hydrocarbyl, C 1 -C 6 Alkoxy or C of (2) 1 -C 6 And m and n are each independently selected from 0 or 1, and m and n are not both 0.
Compared with the prior art, the thiophene compound disclosed by the invention has a thiophene structure and a sulfonyl structure (-SO) 2 (-) bonding, forming an electronically insulating interface layer at the interface of the electrode electrolyte, which is not easy to cause self-discharge of the battery, is favorable for improving the high-temperature storage performance of the lithium ion battery, and has the advantages of stabilityThe fixed lithium ion transmission channel can rapidly transfer lithium ions into the graphite layer for storage, and ensures normal intercalation of the lithium ions in the graphite, so that the high-temperature cycle performance of the battery is improved, and the lithium ion transmission channel is not easy to shrink at low temperature, so that the low-temperature performance of the battery is improved. Meanwhile, the sulfonyl structure reacts at the anode/electrolyte interface during the first charge to form an interface film containing S, O, and the interface film is relatively stable under the high-temperature condition, so that the high-temperature storage performance of the lithium ion battery can be considerably further improved; in addition, the thiophene compound has a symmetrical structure, the coordination degree of the thiophene compound and EC is greatly reduced, EC can fully react in the primary formation process, EC does not participate in the restoration of an SEI interface at the later period of battery circulation, gas production at the later period of circulation is inhibited, and the circulation of the battery is ensured. Therefore, the electrolyte provided by the invention can improve the high-temperature storage, high-temperature cycle performance and low-temperature performance of the lithium ion battery, and can inhibit high-temperature cycle gas production.
Preferably, R of the present invention 1 ～R 10 Each independently selected from hydrogen or C 1 -C 6 Is a hydrocarbon group.
Preferably, the additive of the present invention comprises at least one of compounds I to V:
preferably, the organic electrolyte solvent of the present invention further includes at least one of dimethyl carbonate (DMC), diethyl carbonate (DEC), ethylmethyl carbonate (EMC), fluoroethylmethyl carbonate (FEMC), propylene Carbonate (PC), butyl acetate (n-BA), γ -butyrolactone (GBL), propyl propionate (n-PP), ethyl Propionate (EP), and Ethyl Butyrate (EB).
Preferably, the mass percentage of the additive in the electrolyte is 0.1-3.0%. Specifically, the mass percentage of the additive in the electrolyte can be, but is not limited to, 0.1%, 0.2%, 0.5%, 1%, 1.3%, 1.9%, 2.5%, 2.7%, 3.0%. The additive provided by the invention has the advantages that the mass percentage content of the additive in the electrolyte is reasonable in design, the performance improvement of the lithium ion battery is not obvious when the content is too low, and the formed interface film is thicker when the content is too high, so that the impedance is increased, and the cycle performance of the lithium ion battery is negatively influenced to a certain extent. Therefore, the content of the thiophene compounds is controlled within the range of 0.1-3.0%, which is favorable for forming a solid interface film with proper thickness on the surfaces of the anode and the cathode, thereby ensuring that each performance of the lithium ion battery is fully exerted.
Preferably, the lithium salt of the present invention comprises lithium hexafluorophosphate (LiPF 6 ) Lithium perchlorate (LiClO) 4 ) Lithium tetrafluoroborate (LiBF) 4 ) Lithium methylsulfonate (LiCH) 3 SO 3 ) Lithium triflate (LiCF) 3 SO 3 ) Lithium dioxalate borate (C) 4 BLiO 8 ) Lithium difluorooxalato borate (C) 2 BF 2 LiO 4 ) Lithium difluorophosphate (LiPO) 2 F 2 ) One or more of lithium difluorobis (oxalato) phosphate (LiDFBP), lithium difluorosulfonimide (LiFSI), and lithium bistrifluoromethylsulfonimide (LiTFSI); the concentration of the lithium salt is 0.5-1.5M. In particular, the concentration of the lithium salt of the present invention may be, but is not limited to, 0.5M, 0.75M, 1M, 1.1M, 1.2M, 1.35M, 1.5M. The concentration of the lithium salt is controlled within the range of 0.5-1.5M, so that the solid interface film is more stable and is not easy to decompose in the charge-discharge cycle process, thereby ensuring various performances of the lithium ion battery.
Preferably, the electrolyte of the present invention further comprises a functional additive selected from one or more of Vinylene Carbonate (VC), vinylene carbonate (VEC), fluoroethylene carbonate (FEC), ethylene Sulfite (ES), 1, 3-Propane Sultone (PS) and ethylene sulfate (DTD). Specifically, the mass percentage of the functional additive in the electrolyte is 0.1-6.0%; more specifically, the mass percent of the functional additive may be, but is not limited to, 0.1%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.2%, 4.8%, 5%, 5.3%, 5.8%, 6%. The functional additive can further improve the high-temperature storage, high-temperature cycle performance, low-temperature performance and high-temperature cycle gas production of the lithium ion battery.
Preferably, the functional additive of the present invention is a mixture of Vinylene Carbonate (VC) and fluoroethylene carbonate (FEC).
In order to achieve the above purpose, the invention also provides a lithium ion battery, which comprises a positive electrode, a negative electrode and a diaphragm, wherein the diaphragm is arranged between the positive electrode and the negative electrode, and the lithium ion battery further comprises the electrolyte containing the thiophene additive, and the positive electrode and the negative electrode are respectively arranged on two sides of the electrolyte.
Compared with the prior art, the lithium ion battery comprises the thiophene compound, wherein the thiophene compound has a thiophene structure and a sulfonyl structure (-SO) 2 And (d) bonding, an electronically insulating interface layer is formed at the interface of the electrode electrolyte, so that self-discharge of the battery is not easy to cause, the high-temperature storage performance of the lithium ion battery is improved, meanwhile, the interface layer is provided with a stable lithium ion transmission channel, lithium ions can be quickly transferred to a graphite layer for storage, normal intercalation of the lithium ions in the graphite is ensured, the high-temperature cycle performance of the battery is improved, and the lithium ion transmission channel is not easy to shrink at low temperature, so that the low-temperature performance of the battery is improved. Meanwhile, the sulfonyl structure reacts at the anode/electrolyte interface during the first charge to form an interface film containing S, O, and the interface film is relatively stable under the high-temperature condition, so that the high-temperature storage performance of the lithium ion battery can be considerably further improved. In addition, the thiophene compound has a symmetrical structure, the coordination degree of the thiophene compound and EC is greatly reduced, EC can fully react in the primary formation process, EC does not participate in the restoration of an SEI interface at the later period of battery circulation, gas production at the later period of circulation is inhibited, and the circulation of the battery is ensured. Therefore, the lithium ion battery has better high-temperature storage, high-temperature circulation performance and low-temperature performance, and can inhibit high-temperature circulation gas production.
Preferably, the positive electrode of the invention is made of nickel cobalt manganese oxide material, and the nickel cobalt manganese oxide material is LiNi x Co y Mn (1-x-y) M z O 2 Wherein 0.6.ltoreq.x<0.9，x+y<1，0≤z<0.08, M is at least one of Al, mg, zr and Ti; the negative electrode is made of carbon negative electrode material, silicon negative electrode material or silicon-carbon negative electrode materialIs prepared.
Preferably, the separator of the present invention adopts Polyethylene (PE), polypropylene (PP), polyethylene-polypropylene-polyethylene composite separator (PE-PP-PE) and Al 2 O 3 One or more of the coated Polyethylenes (PE).
Detailed Description
For further understanding of the present invention, the technical aspects of the present invention will be clearly and fully described in connection with the following embodiments, and it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
All the raw materials of the present invention are not particularly limited in their sources, and may be purchased on the market or prepared according to conventional methods well known to those skilled in the art. All the raw materials of the present invention are not particularly limited in purity, and the present invention preferably employs analytically pure or conventional purity in the field of lithium ion battery electrolytes.
Example 1
Preparation of electrolyte:
in a glove box (O) 2 ＜1ppm，H 2 O < 1 ppm), uniformly mixing Ethylene Carbonate (EC), propylene Carbonate (PC), ethyl Propionate (EP) and diethyl carbonate (DEC) according to a mass ratio of 6:3:2:2, taking the obtained mixed solvent as an organic electrolyte solvent, and adding an additive and a functional additive to obtain a mixed solution. Sealing and packaging the mixed solution, freezing for 2 hr in a quick freezing chamber (-4deg.C), taking out, and placing in a glove box (O) filled with nitrogen 2 ＜1ppm，H 2 O is less than 1 ppm), slowly adding lithium hexafluorophosphate into the mixed solution, and uniformly mixing to obtain the lithium ion battery electrolyte.
Preparation of a positive plate:
ternary material LiNi 0.8 Co 0.1 Mn 0.1 Zr 0.03 O 2 Uniformly mixing a conductive agent SuperP, an adhesive PVDF and a Carbon Nano Tube (CNT) according to a mass ratio of 97.5:1.5:1:1 to prepare a certain viscosityThe positive electrode slurry of the lithium ion battery is coated on aluminum foil for a current collector, and the coating weight of the positive electrode slurry is 324g/m 2 Drying at 85 ℃ and then cold pressing; then trimming, cutting pieces, splitting, drying at 85 ℃ for 4 hours under vacuum condition after splitting, and welding the tab to prepare the lithium ion battery positive plate meeting the requirements.
Preparing a negative plate:
mixing artificial graphite and silicon according to a mass ratio of 90:10, preparing slurry with a conductive agent SuperP, a thickener CMC and an adhesive SBR (styrene butadiene rubber emulsion) according to a mass ratio of 95:1.5:1.0:2.5, uniformly mixing, coating the mixed slurry on two sides of a copper foil, drying, and rolling to obtain a negative plate, thus preparing the lithium ion battery negative plate meeting the requirements.
Preparation of a lithium ion battery:
the positive plate, the negative plate and the polypropylene diaphragm prepared according to the process are manufactured into a lithium ion battery with the thickness of 4.7mm, the width of 55mm and the length of 60mm through a lamination process, and the lithium ion battery is baked for 10 hours at the temperature of 75 ℃ in vacuum and injected with the electrolyte. After 24h of standing, charging to 4.4V with a constant current of 0.lC (180 mA), and then charging to a current falling to 0.05C (90 mA) with a constant voltage of 4.4V; then discharging to 3.0V at 0.2C (180 mA), repeating the charge and discharge for 2 times, and finally charging the battery to 3.8V at 0.2C (180 mA) to finish the manufacturing of the lithium ion battery.
The composition of the lithium ion battery electrolytes of examples 1 to 15 and comparative examples 1 to 6 is shown in table 1, wherein the preparation processes of the lithium ion battery electrolytes, the positive electrode sheet, the negative electrode sheet, and the lithium ion battery of examples 2 to 15 and comparative examples 1 to 6 are the same as example 1.
Table 1 composition of lithium ion battery electrolytes of examples and comparative examples
The compound 6 is a fluorine-containing thiophene sulfonamide compound, and the structural formula is shown as follows:
the lithium ion batteries prepared in examples 1 to 15 and comparative examples 1 to 6 were subjected to high temperature storage, high temperature cycle performance, normal temperature cycle performance, low temperature performance test, high temperature cycle gas production test under the following conditions, and the results are shown in table 2.
High temperature storage performance test:
lithium ion batteries were charged and discharged at 0.5C/0.5C once (the discharge capacity of the battery was recorded as C) at normal temperature (25 ℃ C.) 0 ) The upper limit voltage was 4.4V, and then the battery was charged to 4.4V under constant current and constant voltage of 0.5C, and the thickness of the battery was measured (the thickness was recorded as D 0 ) The method comprises the steps of carrying out a first treatment on the surface of the The cell was placed in an oven at 60 ℃ for 30D, taken out and the cell thickness was measured (thickness noted as D 1 ) The method comprises the steps of carrying out a first treatment on the surface of the The cell was placed in a 25 ℃ environment and subjected to 0.5C discharge (discharge capacity recorded as C 1 ) The method comprises the steps of carrying out a first treatment on the surface of the The lithium ion battery is continuously charged and discharged at the normal temperature (25 ℃) for 0.5C/0.5C once (the discharge capacity of the battery is recorded as C) 2 ) The upper limit voltage was 4.4V, and the capacity retention rate, the capacity recovery rate, and the thickness expansion rate were calculated.
Capacity retention= (C 1 /C 0 )*100％
Capacity recovery rate= (C 2 /C 0 )*100％
Thickness expansion ratio= (D 1 -D 0 /D 0 )*100％
And (3) testing normal temperature cycle performance:
the lithium ion battery is charged and discharged at the normal temperature (25 ℃) at 1.0C/1.0C (the discharge capacity of the battery is C) 0 ) The upper limit voltage was 4.4V, and then charging and discharging at 1.0C/1.0C was performed for 500 weeks under normal temperature conditions (the discharge capacity of the battery was C) 1 ) The capacity retention rate was calculated.
Capacity retention= (C 1 /C 0 )*100％
High temperature cycle test:
the lithium ion battery is charged and discharged at 1.0C/1.0C once under the condition of overhigh temperature (45 ℃) (the discharge capacity of the battery is C) 0 ) The upper limit voltage was 4.4V, and then charging and discharging at 1.0C/1.0C was performed for 400 weeks under normal temperature conditions (the battery discharge capacity was C) 1 ) The capacity retention rate was calculated.
Capacity retention= (C 1 /C 0 )*100％
Low temperature performance test:
at normal temperature (25deg.C), the lithium ion battery is charged and discharged once at 0.5C/0.5 (the cut-off voltage of the battery is 3.0V, and the discharge capacity is C) 0 ) The upper limit voltage was 4.4V (off current 0.05C). Then the battery is fully charged to 4.4V (cut-off current 0.05C) at normal temperature (25 ℃) and then the battery is transferred to the condition of minus 20 ℃ for standing for 4 hours, the 0.5C is discharged to 3.0V, and the discharge capacity is C 1 The capacity retention rate was calculated.
Capacity retention= (C 1 /C 0 )*100％
And (3) high-temperature circulating gas production test:
the battery was fully charged at 0.5C to 4.4V (off-current 0.05C) at normal temperature (25 ℃ C.) and tested for battery thickness D 1 The fully charged cell was then charged and discharged at 45℃for 400 weeks at 1.0C/1.0C, and the cell thickness D was measured 2 And calculating the expansion rate of the high-temperature circulating produced gas.
Expansion ratio= (D 2 -D 1 )/D 1 *100％
Table 2 lithium ion battery performance test results
As can be seen from Table 2, each performance of the lithium ion batteries of examples 1 to 8 is superior to that of comparative example 1, because the thiophene compound of the invention is bonded with the sulfonyl structure (-SO 2-) through the thiophene structure, and forms an electronically insulating interface layer at the interface of the electrode electrolyte, the self-discharge of the battery is not easy to cause, the high-temperature storage performance of the lithium ion battery is improved, meanwhile, the interface layer has a stable lithium ion transmission channel, lithium ions can be rapidly transmitted to a graphite layer for storage, and the normal intercalation of lithium ions in graphite is ensured, thereby being beneficial to improving the high-temperature cycle performance of the battery, and the lithium ion transmission channel is not easy to shrink at low temperature, thereby being beneficial to improving the low-temperature performance of the battery. Meanwhile, the sulfonyl structure reacts at the anode/electrolyte interface during the first charge to form an interface film containing S, O, and the interface film is relatively stable under the high-temperature condition, so that the high-temperature storage performance of the lithium ion battery can be considerably further improved; in addition, the thiophene compound has a symmetrical structure, the coordination degree of the thiophene compound and EC is greatly reduced, EC can fully react in the primary formation process, EC does not participate in the restoration of an SEI interface at the later period of battery circulation, gas production at the later period of circulation is inhibited, and the circulation of the battery is ensured. Therefore, the electrolyte provided by the invention can improve the high-temperature storage, high-temperature cycle performance and low-temperature performance of the lithium ion battery, and can inhibit high-temperature cycle gas production.
As can be seen from table 2, the high-temperature cycle gas production of comparative example 6 is more serious than that of example 1, and the inventors of the present invention found that this is due to the fact that after the fluorothiophene sulfonamide compound is coordinated with EC, the film formation of EC is inhibited, so that EC cannot sufficiently participate in the formation of an interface protection layer, the coordination balance is destroyed in the later cycle of the battery, EC participates in the repair of the SEI interface again, gas is produced in the battery in the later cycle, and sudden water jump of the battery is caused, and the battery performance is deteriorated; the thiophene compound has a symmetrical structure, the coordination degree with the EC is greatly reduced, the EC can fully react in the primary formation process, the gas production in the later period of battery circulation is inhibited, and the battery circulation is ensured.
Finally, it should be noted that the above embodiments are only for illustrating the technical solution of the present invention and not for limiting the scope of the present invention, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the present invention can be modified or substituted without departing from the spirit and scope of the technical solution of the present invention.
Claims (10)
1. The electrolyte containing the thiophene additive comprises an organic electrolyte solvent, lithium salt and the additive, and is characterized in that the organic electrolyte solvent comprises ethylene carbonate, the additive comprises a thiophene compound, and the structure of the thiophene compound is shown as formula 1:
wherein X, Y are each independently selected from nitrogen or carbon, R 1 ～R 10 Each independently selected from hydrogen, halogen, C 1 -C 6 C is a hydrocarbon group of (C) 1 -C 6 Halogen-substituted hydrocarbyl, C 1 -C 6 Alkoxy or C of (2) 1 -C 6 And m and n are each independently selected from 0 or 1, and m and n are not both 0.
2. The electrolyte containing thiophene additives according to claim 1, wherein R 1 ～R 10 Each independently selected from hydrogen or C 1 -C 6 Is a hydrocarbon group.
3. The thiophene-containing electrolyte of claim 1, wherein the additive comprises at least one of compounds I to V:
4. the thiophene additive-containing electrolyte according to claim 1, wherein the organic electrolyte solvent further comprises at least one of dimethyl carbonate, diethyl carbonate, methylethyl carbonate, fluoromethyl ethyl carbonate, propylene carbonate, butyl acetate, propyl propionate, ethyl propionate, and ethyl butyrate.
5. The thiophene additive-containing electrolyte according to claim 1, wherein the additive is contained in the electrolyte in an amount of 0.1 to 3.0% by mass.
6. The thiophene additive-containing electrolyte of claim 1, wherein the lithium salt comprises one or more of lithium hexafluorophosphate, lithium perchlorate, lithium tetrafluoroborate, lithium methylsulfonate, lithium trifluoromethylsulfonate, lithium dioxalate borate, lithium difluorooxalato borate, lithium difluorophosphate, lithium difluorobis-oxalato phosphate, lithium bis-fluorosulfonyl imide, and lithium bis-trifluoromethylsulfonyl imide; the concentration of the lithium salt is 0.5-1.5M.
7. The thiophene additive-containing electrolyte of claim 1, further comprising a functional additive selected from one or more of vinylene carbonate, fluoroethylene carbonate, ethylene sulfite, 1, 3-propane sultone, and ethylene sulfate.
8. The thiophene additive-containing electrolyte of claim 7, wherein the functional additive is a mixture of vinylene carbonate and fluoroethylene carbonate.
9. A lithium ion battery comprising a positive electrode, a negative electrode and a diaphragm, wherein the diaphragm is arranged between the positive electrode and the negative electrode, and the lithium ion battery is characterized by further comprising the electrolyte containing thiophene additives according to any one of claims 1-8, wherein the positive electrode and the negative electrode are respectively arranged on two sides of the electrolyte.
10. The lithium-ion battery of claim 9, wherein the positive electrode is formed of nickel cobalt manganeseThe nickel cobalt manganese oxide material is LiNi x Co y Mn (1-x-y) M z O 2 Wherein 0.6.ltoreq.x<0.9，x+y<1，0≤z<0.08, M is at least one of Al, mg, zr and Ti; the negative electrode is made of a carbon negative electrode material, a silicon negative electrode material or a silicon carbon negative electrode material.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310915551.XA CN116799306A (en) | 2023-07-25 | 2023-07-25 | Electrolyte containing thiophene additive and lithium ion battery using electrolyte |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310915551.XA CN116799306A (en) | 2023-07-25 | 2023-07-25 | Electrolyte containing thiophene additive and lithium ion battery using electrolyte |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116799306A true CN116799306A (en) | 2023-09-22 |
Family
ID=88034891
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310915551.XA Pending CN116799306A (en) | 2023-07-25 | 2023-07-25 | Electrolyte containing thiophene additive and lithium ion battery using electrolyte |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116799306A (en) |
-
2023
- 2023-07-25 CN CN202310915551.XA patent/CN116799306A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109216759B (en) | Lithium ion battery electrolyte and lithium ion battery | |
| CN109728340B (en) | Lithium ion battery | |
| CN113851713B (en) | Electrolyte additive, electrolyte containing additive and lithium ion battery | |
| CN113437363A (en) | Non-aqueous electrolyte and secondary battery thereof | |
| CN111834665B (en) | High-nickel ternary lithium ion battery electrolyte and lithium ion battery | |
| WO2021238052A1 (en) | Electrolyte of lithium-ion secondary battery and application thereof | |
| KR20190080040A (en) | Non-Aqueous Electrolyte Solution for Secondary Battery and Secondary Battery Comprising the Same | |
| CN113113668B (en) | Electrolyte additive, non-aqueous electrolyte containing electrolyte additive and lithium ion battery | |
| CN111883834B (en) | Non-aqueous lithium ion battery electrolyte additive, electrolyte containing non-aqueous lithium ion battery electrolyte additive and lithium ion battery | |
| CN114156541B (en) | Electrolyte additive, electrolyte containing additive and lithium ion battery | |
| CN114520371B (en) | Nonaqueous electrolyte and lithium ion battery comprising same | |
| CN116387622A (en) | Electrolyte for lithium ion battery and lithium ion battery containing electrolyte | |
| CN114447432B (en) | Non-aqueous electrolyte of lithium ion battery and lithium ion battery | |
| CN110970663A (en) | Non-aqueous electrolyte and lithium ion battery | |
| CN111952667B (en) | Electrolyte additive, electrolyte containing additive and lithium ion battery | |
| CN112038697A (en) | Lithium ion battery non-aqueous electrolyte and lithium ion battery | |
| CN116799306A (en) | Electrolyte containing thiophene additive and lithium ion battery using electrolyte | |
| CN114552015B (en) | Electrolyte additive, lithium ion battery electrolyte and lithium ion battery | |
| CN113764736B (en) | Electrolyte for lithium ion battery, preparation method of electrolyte and lithium ion battery | |
| CN116885282A (en) | Lithium ion battery electrolyte and lithium ion battery | |
| CN116779973A (en) | High-voltage electrolyte and lithium ion battery | |
| CN116759647A (en) | Electrolyte containing phosphate additive and lithium ion battery using electrolyte | |
| CN116544508A (en) | Electrolyte and electrochemical device thereof | |
| CN117352840A (en) | Nonaqueous electrolyte and secondary battery thereof | |
| CN116454386A (en) | Electrolyte and lithium ion battery thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |