CN113140799A - Overcharge-prevention low-temperature electrolyte and lithium ion battery based on same - Google Patents
Overcharge-prevention low-temperature electrolyte and lithium ion battery based on same Download PDFInfo
- Publication number
- CN113140799A CN113140799A CN202110594221.6A CN202110594221A CN113140799A CN 113140799 A CN113140799 A CN 113140799A CN 202110594221 A CN202110594221 A CN 202110594221A CN 113140799 A CN113140799 A CN 113140799A
- Authority
- CN
- China
- Prior art keywords
- carbonate
- low
- lithium
- overcharge
- temperature
- 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
- 239000003792 electrolyte Substances 0.000 title claims abstract description 91
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 title claims abstract description 63
- 229910001416 lithium ion Inorganic materials 0.000 title claims abstract description 63
- -1 lithium hexafluorophosphate Chemical compound 0.000 claims abstract description 75
- 239000000654 additive Substances 0.000 claims abstract description 67
- 230000000996 additive effect Effects 0.000 claims abstract description 44
- ATGCJUULFWEWPY-UHFFFAOYSA-N 1,4-ditert-butyl-2,5-dimethoxybenzene Chemical group COC1=CC(C(C)(C)C)=C(OC)C=C1C(C)(C)C ATGCJUULFWEWPY-UHFFFAOYSA-N 0.000 claims abstract description 43
- 229910001496 lithium tetrafluoroborate Inorganic materials 0.000 claims abstract description 37
- VAYTZRYEBVHVLE-UHFFFAOYSA-N 1,3-dioxol-2-one Chemical compound O=C1OC=CO1 VAYTZRYEBVHVLE-UHFFFAOYSA-N 0.000 claims abstract description 35
- FSSPGSAQUIYDCN-UHFFFAOYSA-N 1,3-Propane sultone Chemical compound O=S1(=O)CCCO1 FSSPGSAQUIYDCN-UHFFFAOYSA-N 0.000 claims abstract description 33
- 229910003002 lithium salt Inorganic materials 0.000 claims abstract description 31
- 159000000002 lithium salts Chemical class 0.000 claims abstract description 31
- WDXYVJKNSMILOQ-UHFFFAOYSA-N 1,3,2-dioxathiolane 2-oxide Chemical compound O=S1OCCO1 WDXYVJKNSMILOQ-UHFFFAOYSA-N 0.000 claims abstract description 29
- 239000002904 solvent Substances 0.000 claims abstract description 27
- 239000003960 organic solvent Substances 0.000 claims abstract description 26
- 150000007942 carboxylates Chemical class 0.000 claims abstract description 8
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 claims abstract description 6
- BTBUEUYNUDRHOZ-UHFFFAOYSA-N Borate Chemical compound [O-]B([O-])[O-] BTBUEUYNUDRHOZ-UHFFFAOYSA-N 0.000 claims abstract description 4
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 claims abstract description 4
- 229910052744 lithium Inorganic materials 0.000 claims abstract description 4
- IGILRSKEFZLPKG-UHFFFAOYSA-M lithium;difluorophosphinate Chemical compound [Li+].[O-]P(F)(F)=O IGILRSKEFZLPKG-UHFFFAOYSA-M 0.000 claims abstract description 4
- XEKOWRVHYACXOJ-UHFFFAOYSA-N Ethyl acetate Chemical compound CCOC(C)=O XEKOWRVHYACXOJ-UHFFFAOYSA-N 0.000 claims description 102
- KMTRUDSVKNLOMY-UHFFFAOYSA-N Ethylene carbonate Chemical compound O=C1OCCO1 KMTRUDSVKNLOMY-UHFFFAOYSA-N 0.000 claims description 35
- RUOJZAUFBMNUDX-UHFFFAOYSA-N propylene carbonate Chemical compound CC1COC(=O)O1 RUOJZAUFBMNUDX-UHFFFAOYSA-N 0.000 claims description 35
- OIFBSDVPJOWBCH-UHFFFAOYSA-N Diethyl carbonate Chemical compound CCOC(=O)OCC OIFBSDVPJOWBCH-UHFFFAOYSA-N 0.000 claims description 34
- SIXOAUAWLZKQKX-UHFFFAOYSA-N carbonic acid;prop-1-ene Chemical compound CC=C.OC(O)=O SIXOAUAWLZKQKX-UHFFFAOYSA-N 0.000 claims description 31
- 150000005676 cyclic carbonates Chemical class 0.000 claims description 10
- 239000000203 mixture Substances 0.000 claims description 10
- 150000005678 chain carbonates Chemical class 0.000 claims description 9
- 150000001733 carboxylic acid esters Chemical class 0.000 claims description 8
- IEJIGPNLZYLLBP-UHFFFAOYSA-N dimethyl carbonate Chemical compound COC(=O)OC IEJIGPNLZYLLBP-UHFFFAOYSA-N 0.000 claims description 6
- FKRCODPIKNYEAC-UHFFFAOYSA-N ethyl propionate Chemical compound CCOC(=O)CC FKRCODPIKNYEAC-UHFFFAOYSA-N 0.000 claims description 6
- 239000003660 carbonate based solvent Substances 0.000 claims description 3
- YKYONYBAUNKHLG-UHFFFAOYSA-N n-Propyl acetate Natural products CCCOC(C)=O YKYONYBAUNKHLG-UHFFFAOYSA-N 0.000 claims description 3
- 229940090181 propyl acetate Drugs 0.000 claims description 3
- NQPDZGIKBAWPEJ-UHFFFAOYSA-N valeric acid Chemical compound CCCCC(O)=O NQPDZGIKBAWPEJ-UHFFFAOYSA-N 0.000 claims description 3
- RBBXSUBZFUWCAV-UHFFFAOYSA-N ethenyl hydrogen sulfite Chemical compound OS(=O)OC=C RBBXSUBZFUWCAV-UHFFFAOYSA-N 0.000 claims description 2
- JBTWLSYIZRCDFO-UHFFFAOYSA-N ethyl methyl carbonate Chemical compound CCOC(=O)OC JBTWLSYIZRCDFO-UHFFFAOYSA-N 0.000 claims description 2
- 239000008151 electrolyte solution Substances 0.000 claims 5
- 239000011259 mixed solution Substances 0.000 description 13
- 230000000052 comparative effect Effects 0.000 description 8
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 6
- 239000006258 conductive agent Substances 0.000 description 6
- 238000000034 method Methods 0.000 description 5
- 239000007773 negative electrode material Substances 0.000 description 5
- 239000007774 positive electrode material Substances 0.000 description 5
- 239000011230 binding agent Substances 0.000 description 3
- 238000002156 mixing Methods 0.000 description 3
- 239000002033 PVDF binder Substances 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 239000011149 active material Substances 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical group [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 2
- 239000006229 carbon black Substances 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
- 238000002485 combustion reaction Methods 0.000 description 2
- 238000005056 compaction Methods 0.000 description 2
- 230000001276 controlling effect Effects 0.000 description 2
- 239000011883 electrode binding agent Substances 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 238000004880 explosion Methods 0.000 description 2
- 239000011888 foil Substances 0.000 description 2
- 229910021389 graphene Inorganic materials 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 239000012528 membrane Substances 0.000 description 2
- 229920002981 polyvinylidene fluoride Polymers 0.000 description 2
- 230000002265 prevention Effects 0.000 description 2
- 230000001105 regulatory effect Effects 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical group [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 229910013075 LiBF Inorganic materials 0.000 description 1
- 229910013872 LiPF Inorganic materials 0.000 description 1
- 101150058243 Lipf gene Proteins 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000011889 copper foil Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000006731 degradation reaction Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000004146 energy storage Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000008014 freezing Effects 0.000 description 1
- 238000007710 freezing Methods 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 229910021385 hard carbon Inorganic materials 0.000 description 1
- GELKBWJHTRAYNV-UHFFFAOYSA-K lithium iron phosphate Chemical compound [Li+].[Fe+2].[O-]P([O-])([O-])=O GELKBWJHTRAYNV-UHFFFAOYSA-K 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000012046 mixed solvent Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000005486 organic electrolyte Substances 0.000 description 1
- 238000009783 overcharge test Methods 0.000 description 1
- 238000013021 overheating Methods 0.000 description 1
- 230000000149 penetrating effect Effects 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 239000002153 silicon-carbon composite material Substances 0.000 description 1
- 230000008961 swelling Effects 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
Images
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
-
- 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
- H01M10/0568—Liquid materials characterised by the solutes
-
- 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
- H01M10/0569—Liquid materials characterised by the solvents
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M2300/00—Electrolytes
- H01M2300/0017—Non-aqueous electrolytes
- H01M2300/0025—Organic electrolyte
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M2300/00—Electrolytes
- H01M2300/0017—Non-aqueous electrolytes
- H01M2300/0025—Organic electrolyte
- H01M2300/0028—Organic electrolyte characterised by the solvent
- H01M2300/0037—Mixture of solvents
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using 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 overcharge-preventing low-temperature electrolyte and a lithium ion battery based on the overcharge-preventing low-temperature electrolyte, and belongs to the technical field of lithium ion batteries. Comprises an organic solvent, lithium salt, a low-impedance film-forming additive and an overcharge-preventing additive; wherein the organic solvent comprises a carbonate solvent and a linear carboxylate solvent; the lithium salt comprises one or more of lithium hexafluorophosphate, lithium difluorophosphate, lithium tetrafluoroborate and lithium difluorooxalato borate; the low-impedance film forming additive is at least two of vinylene carbonate, 1, 3-propane sultone and ethylene sulfite; the anti-overcharging additive is 1, 4-di-tert-butyl-2, 5 dimethoxybenzene; wherein, the organic solvent is 78 wt% -82 wt%, the lithium salt is 15 wt% -18 wt%, the anti-overcharging additive is 1 wt% -2 wt%, and the rest is low-impedance film forming additive. The invention solves the problems that the discharge capacity of the existing lithium ion battery is lower at low temperature, even can not discharge and the safety problem caused by over-charge and discharge.
Description
Technical Field
The invention belongs to the technical field of lithium ion batteries, and relates to an overcharge-preventing low-temperature electrolyte and a lithium ion battery based on the overcharge-preventing low-temperature electrolyte.
Background
With the progress of energy technology, lithium ion batteries are more and more widely applied in the fields of digital, power, energy storage, military aerospace and the like. The expansion of the application scene requires that the lithium ion battery has the characteristics of high and low temperature performance, especially the special requirements under the extreme low temperature condition. Meanwhile, the conventional lithium ion battery mostly uses carbonate and carboxylate organic electrolyte which are easy to combust, so that combustion and even explosion are possibly caused under extreme working conditions such as overcharge, overdischarge and overheating, and great potential safety hazards are caused. Therefore, the development of an electrolyte with high safety and low temperature resistance is a key to solve the above problems, and is an urgent technical performance requirement of the application market for the lithium ion battery.
Disclosure of Invention
In order to overcome the defects of the prior art, the invention aims to provide an overcharge-proof low-temperature electrolyte and a lithium ion battery based on the overcharge-proof low-temperature electrolyte, which solve the problems that the discharge capacity is low at low temperature and even discharge cannot be realized and the safety problem caused by overcharge and discharge is solved, and the lithium ion battery based on the overcharge-proof low-temperature electrolyte has excellent overcharge-proof performance and excellent ultralow-temperature discharge performance.
In order to achieve the purpose, the invention adopts the following technical scheme to realize the purpose:
the invention discloses an overcharge-prevention low-temperature electrolyte, which comprises an organic solvent, lithium salt, a low-impedance film-forming additive and an overcharge-prevention additive; wherein the organic solvent comprises a carbonate solvent and a linear carboxylate solvent; the lithium salt comprises one or more of lithium hexafluorophosphate, lithium difluorophosphate, lithium tetrafluoroborate and lithium difluorooxalato borate; the low-impedance film forming additive is at least two of vinylene carbonate, 1, 3-propane sultone and ethylene sulfite; the anti-overcharging additive is 1, 4-di-tert-butyl-2, 5 dimethoxybenzene; wherein, the organic solvent is 78 wt% -82 wt%, the lithium salt is 15 wt% -18 wt%, the low-impedance film-forming additive is 2 wt% -4 wt%, and the anti-overcharging additive is 1 wt% -2 wt%.
Preferably, the carbonate-based solvent is a combination of at least two cyclic carbonates and at least two chain carbonates of ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate and methyl ethylene carbonate.
More preferably, the chain carbonate is diethyl carbonate and methyl ethylene carbonate, and the chain carbonate is 15 wt% to 20 wt%.
More preferably, the cyclic carbonate is ethylene carbonate or propylene carbonate, and the cyclic carbonate is 25 wt% to 30 wt%.
Preferably, the linear carboxylate solvent is at least one of ethyl acetate, propyl acetate and ethyl propionate.
More preferably, the linear carboxylic acid ester is ethyl acetate and the linear carboxylic acid ester is 35 wt% to 40 wt%.
Preferably, the lithium salt is a mixture of lithium hexafluorophosphate and lithium tetrafluoroborate.
More preferably, the lithium hexafluorophosphate is present in an amount of 14 to 16 wt%, and the lithium tetrafluoroborate is present in an amount of 1 to 4 wt%.
Preferably, the low impedance film forming additive is a blend of vinylene carbonate, 1, 3-propane sultone, and vinyl sulfite.
Further preferably, the low impedance film forming additive is 2 wt% to 4 wt%.
The invention discloses a lithium ion battery which comprises a positive plate, a diaphragm, a negative plate and the overcharge-preventing low-temperature electrolyte.
Compared with the prior art, the invention has the following beneficial effects:
the invention discloses an overcharge-prevention low-temperature electrolyte, which can effectively reduce the freezing point of the electrolyte and improve the conductivity of the electrolyte at low temperature by using a multi-element mixed solvent of a carbonate solvent and a carboxylate solvent and a mixed lithium salt; by using the low-impedance film forming additive, the impedance of the SEI film can be effectively reduced, and lithium ions can rapidly penetrate through the SEI film to generate a lithium-inserting and lithium-removing reaction; by using the overcharge-preventing additive 1, 4-di-tert-butyl-2, 5 dimethoxybenzene, the safety of the lithium ion battery under the condition of low-temperature charging can be improved, and the safety risk caused by overcharge can be prevented. Therefore, the overcharge-prevention low-temperature electrolyte has good low-temperature performance and excellent overcharge-prevention safety performance, and can well solve the problems of poor low-temperature performance and safety caused by overcharge and discharge of the conventional lithium ion battery.
Further, at least two cyclic carbonates and at least two chain carbonates are selected, so that the electrolyte can have high ionic conductivity and low viscosity at the same time.
Further, by selecting diethyl carbonate and methylethyl carbonate and limiting the amounts thereof, the electrolyte can be made to have a lower viscosity. By selecting ethylene carbonate and propylene carbonate and limiting the dosage of the ethylene carbonate and the propylene carbonate, the electrolyte has higher dielectric constant, and lithium salt is fully ionized, so that higher ionic conductivity is obtained.
Further, the selection of an appropriate linear carboxylate solvent can further reduce the viscosity of the electrolyte, particularly at low temperatures.
Further, by selecting ethyl acetate and limiting the amount thereof, it can be ensured that the electrolyte does not solidify under low temperature conditions and has a low viscosity.
Furthermore, by selecting lithium hexafluorophosphate and lithium tetrafluoroborate and limiting the use amount of the lithium hexafluorophosphate and the lithium tetrafluoroborate, the electrolyte can be ensured to have higher ionic conductivity under the conditions of room temperature and low temperature.
Furthermore, by selecting the low-impedance film-forming additive component, the SEI film impedance can be reduced, the rate of lithium ions penetrating the SEI film is improved, and the low-temperature charge and discharge performance of the battery is effectively improved; and 1, 4-di-tert-butyl-2, 5-dimethoxybenzene is used as an overcharge-preventing additive, so that the overcharge tolerance of the battery below 3.9V can be effectively improved, and the battery is protected from gas expansion or liquid leakage when the battery is overcharged to 3.9V.
The invention also discloses a lithium ion battery, which is formed by adopting the anti-overcharging low-temperature electrolyte and matching with the positive plate, the diaphragm and the negative plate, and can effectively improve the charge and discharge capacity of the lithium ion battery under the low-temperature condition and the safety performance of the lithium ion battery under the overcharging condition. Therefore, the lithium ion battery using the electrolyte has excellent overcharge prevention performance and low-temperature discharge performance, and can meet normal use and safe use under extreme low-temperature conditions.
In summary, in the overcharge-prevention low-temperature electrolyte disclosed by the invention and the lithium ion battery based on the overcharge-prevention low-temperature electrolyte, the ionic conductivity at low temperature is improved by regulating and controlling the composition of an electrolyte solvent; regulating and controlling a film forming additive to reduce the SEI film impedance; the addition of the overcharge-preventing additive improves the stability of the electrolyte at high potential, and is an important method for improving the low-temperature performance and the overcharge safety performance of the lithium ion battery.
Drawings
FIG. 1 is a schematic diagram of a-40 ℃ low-temperature discharge curve of a lithium ion battery using the overcharge-preventing low-temperature electrolyte.
Detailed Description
In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It should be noted that the terms "first," "second," and the like in the description and claims of the present invention and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in sequences other than those illustrated or described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
An overcharge-resistant low-temperature electrolyte comprises an organic solvent, a lithium salt and additives, wherein the additives comprise a low-resistance film-forming additive and an overcharge-resistant additive.
The organic solvent composition of the anti-overcharging low-temperature electrolyte comprises a carbonate solvent and a linear carboxylic ester solvent. The carbonate-based solvent is selected from a combination of at least two cyclic carbonates and at least two chain carbonates of Ethylene Carbonate (EC) and Propylene Carbonate (PC), dimethyl carbonate (DMC), diethyl carbonate (DEC), and methyl ethylene carbonate (EMC). The linear carboxylic acid ester is at least one selected from Ethyl Acetate (EA), propyl acetate and ethyl propionate. The organic solvent accounts for 78-82 wt% based on the total weight of the electrolyte as 100%.
Preferably, the linear carboxylic ester is ethyl acetate, and the linear carboxylic ester accounts for 35 wt% -40 wt% of the total weight of the electrolyte as 100%.
Preferably, the chain carbonate is diethyl carbonate and methyl ethylene carbonate, and accounts for 15 wt% -20 wt% of the total weight of the electrolyte.
Preferably, the cyclic carbonate is ethylene carbonate and propylene carbonate, and the cyclic carbonate accounts for 25 wt% to 30 wt% of the total weight of the electrolyte as 100%.
The lithium salt composition of the overcharge-preventing low-temperature electrolyte comprises one or more of lithium hexafluorophosphate, lithium difluorophosphate, lithium tetrafluoroborate and lithium difluorooxalato borate.
Preferably, the lithium salt is lithium hexafluorophosphate (LiPF)6) And lithium tetrafluoroborate (LiBF)4) By mixing ofThe total weight of the electrolyte is 100 percent, the lithium salt accounts for 15 to 18 percent by weight, the lithium hexafluorophosphate accounts for 14 to 16 percent by weight, and the lithium tetrafluoroborate accounts for 1 to 4 percent by weight.
The additive composition of the anti-overcharging low-temperature electrolyte comprises a film forming additive and an anti-overcharging additive. The film forming additive is at least two of Vinylene Carbonate (VC), 1, 3-Propane Sultone (PS) and Ethylene Sulfite (ES). The anti-overcharging additive is 1, 4-di-tert-butyl-2, 5-dimethoxybenzene (DDB).
Preferably, the film forming additive is a mixture of Vinylene Carbonate (VC), 1, 3-Propane Sultone (PS) and Ethylene Sulfite (ES), and the low-resistance film forming additive accounts for 2-4 wt% and the anti-overcharging additive accounts for 1-2 wt% of the total weight of the electrolyte, based on 100% of the total weight of the electrolyte.
The invention also provides a preparation method of the electrolyte, which comprises the following steps: the electrolyte is prepared by mixing an organic solvent, a lithium salt and the above additives, and the mixing is not limited by the order of addition.
The invention also provides a lithium ion battery which comprises the electrolyte. The lithium ion battery comprises a positive plate, a diaphragm and a negative plate, wherein the diaphragm is arranged between the positive plate and the negative plate.
Specifically, in a specific embodiment of the present invention, the positive electrode sheet includes one or two positive electrode active material layers and a positive electrode current collector. The positive active material layer comprises a positive active material, a conductive agent and a positive binder, the positive active material is lithium iron phosphate, the conductive agent is at least two of carbon black, graphene and carbon nanotubes, and the positive binder is PVDF. The positive current collector is an aluminum foil or a carbon-coated aluminum foil. When the positive active material is coated, the content of the active material is 92 wt% -98 wt%, the content of the conductive agent is 1 wt% -3 wt%, the content of PVDF is 2 wt% -3 wt%, and the coating amount is 20-32 mg/cm2The compaction density is 2.1-2.3 mg/cm3。
Specifically, in a specific embodiment of the present invention, the negative electrode sheet includes one or two negative electrode active material layers and a negative electrode current collector. It is composed ofThe middle negative electrode active material layer comprises a negative electrode active material and a conductive agent negative electrode binder, the negative electrode active material is one or more of graphite, hard carbon, a silicon-carbon composite material and a silica material, the conductive agent is at least one of carbon black, graphene and carbon nanotubes, and the negative electrode binder is one of CMC + SBR, PAA and PAN. The negative current collector is a copper foil. When the negative active material is coated, the content of the active material is 92 wt% -96 wt%, the content of the conductive agent is 1 wt% -3 wt%, the content of the binder is 2.5 wt% -5 wt%, and the coating amount is 8-16 mg/cm2The compaction density is 1.2-1.6 mg/cm3。
In particular, in a particular embodiment of the invention, the membrane is selected from polymeric porous membranes.
The invention is described in further detail below with reference to the following figures and specific examples:
example 1
The solvents of ethyl acetate, ethylene carbonate, propylene carbonate, diethyl carbonate and methyl ethylene carbonate are mixed, vinylene carbonate, 1, 3-propane sultone, ethylene sulfite and 1, 4-di-tert-butyl-2, 5-dimethoxybenzene are added into the mixed solution as additives, and finally lithium hexafluorophosphate and lithium tetrafluoroborate are added to obtain the overcharge-preventing low-temperature electrolyte of example 1.
In the obtained anti-overcharging low-temperature electrolyte, the components are as follows by mass percent: 36 wt% of ethyl acetate, 12 wt% of ethylene carbonate, 13 wt% of propylene carbonate, 15 wt% of diethyl carbonate, 2 wt% of methyl ethylene carbonate as an organic solvent (78 wt%), 14 wt% of lithium hexafluorophosphate and 3 wt% of lithium tetrafluoroborate as a lithium salt (17 wt%), 1.5 wt% of vinylene carbonate, 1.2 wt% of 1, 3-propane sultone and 0.3 wt% of ethylene sulfite as low-resistance film-forming additives (3 wt%), and 2 wt% of 1, 4-di-tert-butyl-2, 5-dimethoxybenzene as 1, 4-di-tert-butyl-2, 5-dimethoxybenzene.
The obtained overcharge-preventing low-temperature electrolyte was injected into an uninjected cell containing a positive electrode sheet, a negative electrode sheet and a separator to prepare a lithium ion battery, and the lithium ion battery of example 1 was obtained.
Example 2
The solvents of ethyl acetate, ethylene carbonate, propylene carbonate, diethyl carbonate and methyl ethylene carbonate are mixed, vinylene carbonate, 1, 3-propane sultone, ethylene sulfite and 1, 4-di-tert-butyl-2, 5-dimethoxybenzene are added into the mixed solution as additives, and finally lithium hexafluorophosphate and lithium tetrafluoroborate are added to obtain the overcharge-preventing low-temperature electrolyte of example 1.
In the obtained anti-overcharging low-temperature electrolyte, the components are as follows by mass percent: 36 wt% of ethyl acetate, 12 wt% of ethylene carbonate, 13 wt% of propylene carbonate, 15 wt% of diethyl carbonate, 2 wt% of methyl ethylene carbonate as an organic solvent (78 wt%), 14 wt% of lithium hexafluorophosphate and 3 wt% of lithium tetrafluoroborate as a lithium salt (17 wt%), 2 wt% of vinylene carbonate, 1, 3-propane sultone and 0.3 wt% of ethylene sulfite as a low-resistance film-forming additive (3 wt%), and 1 wt% of 1, 4-di-tert-butyl-2, 5-dimethoxybenzene as 1, 4-di-tert-butyl-2, 5-dimethoxybenzene.
The obtained overcharge-preventing low-temperature electrolyte was injected into an uninjected cell containing a positive electrode sheet, a negative electrode sheet, and a separator to prepare a lithium ion battery, and the lithium ion battery of example 2 was obtained.
Example 3
The solvents of ethyl acetate, ethylene carbonate, propylene carbonate, diethyl carbonate and methyl ethylene carbonate are mixed, vinylene carbonate, 1, 3-propane sultone, ethylene sulfite and 1, 4-di-tert-butyl-2, 5-dimethoxybenzene are added into the mixed solution as additives, and finally lithium hexafluorophosphate and lithium tetrafluoroborate are added to obtain the overcharge-preventing low-temperature electrolyte of example 1.
In the obtained anti-overcharging low-temperature electrolyte, the components are as follows by mass percent: 37 wt% of ethyl acetate, 12 wt% of ethylene carbonate, 13 wt% of propylene carbonate, 15 wt% of diethyl carbonate, 2 wt% of methyl ethylene carbonate as an organic solvent (79 wt%), 14 wt% of lithium hexafluorophosphate and 3 wt% of lithium tetrafluoroborate as a lithium salt (17 wt%), 1 wt% of vinylene carbonate, 0.7 wt% of 1, 3-propane sultone and 0.3 wt% of ethylene sulfite as a low-resistance film-forming additive (2 wt%), and 2 wt% of 1, 4-di-tert-butyl-2, 5-dimethoxybenzene as 1, 4-di-tert-butyl-2, 5-dimethoxybenzene.
The obtained overcharge-preventing low-temperature electrolyte was injected into an uninjected cell containing a positive electrode sheet, a negative electrode sheet, and a separator to prepare a lithium ion battery, and the lithium ion battery of example 3 was obtained.
Example 4
The solvents of ethyl acetate, ethylene carbonate, propylene carbonate, diethyl carbonate and methyl ethylene carbonate are mixed, vinylene carbonate, 1, 3-propane sultone, ethylene sulfite and 1, 4-di-tert-butyl-2, 5-dimethoxybenzene are added into the mixed solution as additives, and finally lithium hexafluorophosphate and lithium tetrafluoroborate are added to obtain the overcharge-preventing low-temperature electrolyte of example 1.
In the obtained anti-overcharging low-temperature electrolyte, the components are as follows by mass percent: 35.5% by weight of ethyl acetate, 13% by weight of ethylene carbonate, 14% by weight of propylene carbonate, 13% by weight of diethyl carbonate, 2% by weight of methyl ethylene carbonate and 4.5% by weight of dimethyl carbonate as organic solvents (82% by weight), 14% by weight of lithium hexafluorophosphate and 1% by weight of lithium tetrafluoroborate as lithium salts (15% by weight), 1% by weight of vinylene carbonate, 0.5% by weight of 1, 3-propanesultone and 0.5% by weight of ethylene sulfite as low-resistance film-forming additives (2% by weight), and 1% by weight of 1, 4-di-tert-butyl-2, 5-dimethoxybenzene as 1, 4-di-tert-butyl-2, 5-dimethoxybenzene.
The obtained overcharge-preventing low-temperature electrolyte was injected into an uninjected cell containing a positive electrode sheet, a negative electrode sheet and a separator to prepare a lithium ion battery, and the lithium ion battery of example 4 was obtained.
Example 5
The solvents of ethyl acetate, ethylene carbonate, propylene carbonate, diethyl carbonate and methyl ethylene carbonate are mixed, vinylene carbonate, 1, 3-propane sultone, ethylene sulfite and 1, 4-di-tert-butyl-2, 5-dimethoxybenzene are added into the mixed solution as additives, and finally lithium hexafluorophosphate and lithium tetrafluoroborate are added to obtain the overcharge-preventing low-temperature electrolyte of example 1.
In the obtained anti-overcharging low-temperature electrolyte, the components are as follows by mass percent: ethyl acetate 35 wt%, ethylene carbonate 12 wt%, propylene carbonate 13 wt%, diethyl carbonate 17 wt%, and methyl ethylene carbonate 3 wt% as organic solvent (80 wt%), lithium hexafluorophosphate 14 wt%, and lithium tetrafluoroborate 3 wt% as lithium salt (17 wt%), vinylene carbonate 1 wt%, 1, 3-propane sultone 0.7 wt%, and ethylene sulfite 0.3 wt% as low-resistance film-forming additive (2 wt%), and 1, 4-di-tert-butyl-2, 5-dimethoxybenzene 1 wt% as 1, 4-di-tert-butyl-2, 5-dimethoxybenzene.
The obtained overcharge-preventing low-temperature electrolyte was injected into an uninjected cell containing a positive electrode sheet, a negative electrode sheet and a separator to prepare a lithium ion battery, and the lithium ion battery of example 5 was obtained.
Example 6
The solvents of ethyl acetate, ethylene carbonate, propylene carbonate, diethyl carbonate and methyl ethylene carbonate are mixed, vinylene carbonate, 1, 3-propane sultone, ethylene sulfite and 1, 4-di-tert-butyl-2, 5-dimethoxybenzene are added into the mixed solution as additives, and finally lithium hexafluorophosphate and lithium tetrafluoroborate are added to obtain the overcharge-preventing low-temperature electrolyte of example 1.
In the obtained anti-overcharging low-temperature electrolyte, the components are as follows by mass percent: ethyl acetate 35 wt%, ethylene carbonate 12 wt%, propylene carbonate 13 wt%, diethyl carbonate 16.5 wt%, and methyl ethylene carbonate 3 wt% as organic solvent (79.5 wt%), lithium hexafluorophosphate 14 wt%, and lithium tetrafluoroborate 1 wt% as lithium salt (15 wt%), vinylene carbonate 2 wt%, 1, 3-propane sultone 1.7 wt%, and ethylene sulfite 0.3 wt% as low resistance film forming additive (4 wt%), and 1, 4-di-tert-butyl-2, 5-dimethoxybenzene 1.5 wt% as 1, 4-di-tert-butyl-2, 5-dimethoxybenzene.
The obtained overcharge-preventing low-temperature electrolyte was injected into an uninjected cell containing a positive electrode sheet, a negative electrode sheet, and a separator to prepare a lithium ion battery, and the lithium ion battery of example 6 was obtained.
Example 7
The solvents of ethyl acetate, ethylene carbonate, propylene carbonate, diethyl carbonate and methyl ethylene carbonate are mixed, vinylene carbonate, 1, 3-propane sultone, ethylene sulfite and 1, 4-di-tert-butyl-2, 5-dimethoxybenzene are added into the mixed solution as additives, and finally lithium hexafluorophosphate and lithium tetrafluoroborate are added to obtain the overcharge-preventing low-temperature electrolyte of example 1.
In the obtained anti-overcharging low-temperature electrolyte, the components are as follows by mass percent: ethyl acetate 35 wt%, ethylene carbonate 14 wt%, propylene carbonate 16 wt%, diethyl carbonate 13 wt%, and methyl ethylene carbonate 2 wt% as organic solvent (80 wt%), lithium hexafluorophosphate 14 wt% and lithium tetrafluoroborate 1 wt% as lithium salt (15 wt%), vinylene carbonate 2 wt%, 1, 3-propane sultone 1.5 wt%, and ethylene sulfite 0.3 wt% as low resistance film forming additive (3.8 wt%), and 1, 4-di-tert-butyl-2, 5-dimethoxybenzene 1.2 wt% as 1, 4-di-tert-butyl-2, 5-dimethoxybenzene.
The obtained overcharge-preventing low-temperature electrolyte was injected into an uninjected cell containing a positive electrode sheet, a negative electrode sheet and a separator to prepare a lithium ion battery, and the lithium ion battery of example 7 was obtained.
Example 8
The solvents of ethyl acetate, ethylene carbonate, propylene carbonate, diethyl carbonate and methyl ethylene carbonate are mixed, vinylene carbonate, 1, 3-propane sultone, ethylene sulfite and 1, 4-di-tert-butyl-2, 5-dimethoxybenzene are added into the mixed solution as additives, and finally lithium hexafluorophosphate and lithium tetrafluoroborate are added to obtain the overcharge-preventing low-temperature electrolyte of example 1.
In the obtained anti-overcharging low-temperature electrolyte, the components are as follows by mass percent: ethyl acetate 40 wt%, ethylene carbonate 12 wt%, propylene carbonate 13 wt%, diethyl carbonate 13 wt%, and methyl ethylene carbonate 2 wt% as organic solvents (80 wt%), lithium hexafluorophosphate 14 wt%, and lithium tetrafluoroborate 1 wt% as lithium salts (15 wt%), vinylene carbonate 1.3 wt%, 1, 3-propane sultone 1.7 wt%, and ethylene sulfite 0.3 wt% as low resistance film forming additives (3.3 wt%), and 1, 4-di-tert-butyl-2, 5-dimethoxybenzene 1.7 wt% as 1, 4-di-tert-butyl-2, 5-dimethoxybenzene.
The obtained overcharge-preventing low-temperature electrolyte was injected into an uninjected cell containing a positive electrode sheet, a negative electrode sheet, and a separator to prepare a lithium ion battery, and the lithium ion battery of example 8 was obtained.
Example 9
The solvents of ethyl acetate, ethylene carbonate, propylene carbonate, diethyl carbonate and methyl ethylene carbonate are mixed, vinylene carbonate, 1, 3-propane sultone, ethylene sulfite and 1, 4-di-tert-butyl-2, 5-dimethoxybenzene are added into the mixed solution as additives, and finally lithium hexafluorophosphate and lithium tetrafluoroborate are added to obtain the overcharge-preventing low-temperature electrolyte of example 1.
In the obtained anti-overcharging low-temperature electrolyte, the components are as follows by mass percent: 38.5 wt% of ethyl acetate, 13.5 wt% of ethylene carbonate, 13 wt% of propylene carbonate, 13 wt% of diethyl carbonate, 2 wt% of methyl ethylene carbonate and 1 wt% of dimethyl carbonate were used as an organic solvent (81 wt%), 15 wt% of lithium hexafluorophosphate and 1 wt% of lithium tetrafluoroborate were used as a lithium salt (16 wt%), 1 wt% of vinylene carbonate and 1, 3-propanesultone were used as low-resistance film-forming additives (2 wt%), and 1 wt% of 1, 4-di-tert-butyl-2, 5-dimethoxybenzene was used as 1, 4-di-tert-butyl-2, 5-dimethoxybenzene.
The obtained overcharge-preventing low-temperature electrolyte was injected into an uninjected cell containing a positive electrode sheet, a negative electrode sheet, and a separator to prepare a lithium ion battery, and the lithium ion battery of example 9 was obtained.
Example 10
The solvents of ethyl acetate, ethylene carbonate, propylene carbonate, diethyl carbonate and methyl ethylene carbonate are mixed, vinylene carbonate, 1, 3-propane sultone, ethylene sulfite and 1, 4-di-tert-butyl-2, 5-dimethoxybenzene are added into the mixed solution as additives, and finally lithium hexafluorophosphate and lithium tetrafluoroborate are added to obtain the overcharge-preventing low-temperature electrolyte of example 1.
In the obtained anti-overcharging low-temperature electrolyte, the components are as follows by mass percent: 37 wt% of ethyl acetate, 12.5 wt% of ethylene carbonate, 13.5 wt% of propylene carbonate, 14 wt% of diethyl carbonate, 1 wt% of methyl ethylene carbonate and 1 wt% of dimethyl carbonate were used as an organic solvent (79 wt%), 14 wt% of lithium hexafluorophosphate and 4 wt% of tetrafluoroboric acid were used as lithium salts (18 wt%), 1 wt% of vinylene carbonate and 1, 3-propanesultone were used as low-resistance film-forming additives (2 wt%), and 1 wt% of 1, 4-di-tert-butyl-2, 5-dimethoxybenzene was used as 1, 4-di-tert-butyl-2, 5-dimethoxybenzene.
The obtained overcharge-preventing low-temperature electrolyte was injected into an uninjected cell containing a positive electrode sheet, a negative electrode sheet, and a separator to prepare a lithium ion battery, and the lithium ion battery of example 10 was obtained.
Comparative example 1
The solvents of ethyl acetate, ethylene carbonate, propylene carbonate, diethyl carbonate and methyl ethylene carbonate are mixed, vinylene carbonate, 1, 3-propane sultone, ethylene sulfite and 1, 4-di-tert-butyl-2, 5-dimethoxybenzene are added into the mixed solution as additives, and finally lithium hexafluorophosphate and lithium tetrafluoroborate are added to obtain the overcharge-preventing low-temperature electrolyte of example 1.
In the obtained anti-overcharging low-temperature electrolyte, the components are as follows by mass percent: ethyl acetate 38 wt%, ethylene carbonate 12 wt%, propylene carbonate 13 wt%, diethyl carbonate 15 wt%, methyl ethylene carbonate 2 wt% as an organic solvent (80 wt%), lithium hexafluorophosphate 14 wt% and lithium tetrafluoroborate 3 wt% as a lithium salt (17 wt%), vinylene carbonate 1.5 wt%, 1, 3-propanesultone 1.2 wt% and ethylene sulfite 0.3 wt% as low resistance film forming additives (3 wt%).
And injecting the obtained overcharge-preventing low-temperature electrolyte into an uninjected battery core containing a positive plate, a negative plate and a diaphragm to prepare the lithium ion battery, thus obtaining the lithium ion battery of the comparative example 1.
Comparative example 2
The solvents of ethyl acetate, ethylene carbonate, propylene carbonate, diethyl carbonate and methyl ethylene carbonate are mixed, vinylene carbonate, 1, 3-propane sultone, ethylene sulfite and 1, 4-di-tert-butyl-2, 5-dimethoxybenzene are added into the mixed solution as additives, and finally lithium hexafluorophosphate and lithium tetrafluoroborate are added to obtain the overcharge-preventing low-temperature electrolyte of example 1.
In the obtained anti-overcharging low-temperature electrolyte, the components are as follows by mass percent: 30 wt% of ethyl acetate, 14 wt% of ethylene carbonate, 16 wt% of propylene carbonate, 15 wt% of diethyl carbonate, 3 wt% of methyl ethylene carbonate as an organic solvent (78 wt%), 14 wt% of lithium hexafluorophosphate and 3 wt% of lithium tetrafluoroborate as a lithium salt (17 wt%), 1.5 wt% of vinylene carbonate, 1.2 wt% of 1, 3-propane sultone and 0.3 wt% of ethylene sulfite as a low-resistance film-forming additive (3 wt%), and 2 wt% of 1, 4-di-tert-butyl-2, 5-dimethoxybenzene as 1, 4-di-tert-butyl-2, 5-dimethoxybenzene.
And injecting the obtained overcharge-preventing low-temperature electrolyte into an uninjected battery core containing a positive plate, a negative plate and a diaphragm to prepare the lithium ion battery, thus obtaining the lithium ion battery of the comparative example 2.
Comparative example 3
The solvents of ethyl acetate, ethylene carbonate, propylene carbonate, diethyl carbonate and methyl ethylene carbonate are mixed, vinylene carbonate, 1, 3-propane sultone, ethylene sulfite and 1, 4-di-tert-butyl-2, 5-dimethoxybenzene are added into the mixed solution as additives, and finally lithium hexafluorophosphate and lithium tetrafluoroborate are added to obtain the overcharge-preventing low-temperature electrolyte of example 1.
In the obtained anti-overcharging low-temperature electrolyte, the components are as follows by mass percent: ethyl acetate 40 wt%, ethylene carbonate 10 wt%, propylene carbonate 10 wt%, diethyl carbonate 15 wt%, and methyl ethylene carbonate 3 wt% as organic solvents (79 wt%), lithium hexafluorophosphate 14 wt%, and lithium tetrafluoroborate 3 wt% as lithium salts (17 wt%), vinylene carbonate 1.5 wt%, 1, 3-propane sultone 1.2 wt%, and ethylene sulfite 0.3 wt% as low resistance film forming additives (3 wt%), and 1, 4-di-t-butyl-2, 5-dimethoxybenzene 2 wt% as 1, 4-di-t-butyl-2, 5-dimethoxybenzene.
And injecting the obtained overcharge-preventing low-temperature electrolyte into an uninjected battery core containing a positive plate, a negative plate and a diaphragm to prepare the lithium ion battery, thus obtaining the lithium ion battery of the comparative example 3.
-40 ℃ low temperature discharge experiment: the batteries obtained in the examples and the comparative examples are placed in an environment of (-40 +/-2) DEG C and are kept still for 16-24 hours, when the battery body reaches (-40 +/-2) DEG C, the cut-off voltage of the battery is 2.0V according to 1C constant current discharge, and the discharge capacity is recorded. And the low-temperature discharge capacity retention rate was obtained as compared with the room-temperature (25 ℃ C.) discharge capacity.
Overcharge experiment: the batteries obtained in examples and comparative examples were charged to 3.9V at a rate of 1C to record the state of the battery, whether or not swelling, liquid leakage, etc.
Table 1 shows the comparison of the low-temperature test and overcharge test results of the lithium ion battery using the overcharge-resistant low-temperature electrolyte according to the present invention;
in conclusion, the conventional lithium ion battery has poor low-temperature discharge performance, serious performance degradation below-10 ℃, and even no discharge. Meanwhile, the abuse of the user terminal may cause overcharge of the lithium ion battery, thereby causing safety accidents such as combustion, explosion and the like. The key to solve the above problems is a lithium ion battery having both excellent low-temperature discharge performance and good overcharge prevention safety performance. Compared with the prior art, the electrolyte can well solve the safety problem of the conventional lithium ion battery caused by overcharge and discharge. The lithium ion battery using the electrolyte has excellent overcharge resistance and low-temperature discharge performance, and can meet normal use and safe use under extreme low-temperature conditions.
Referring to fig. 1, it can be seen that the lithium ion battery using the overcharge-prevention low-temperature electrolyte disclosed by the invention can significantly improve the low-temperature discharge capacity and the low-temperature pull-down voltage. Under the low-temperature environment of minus 40 ℃, the 1C discharge capacity reaches more than 85 percent of the room-temperature discharge capacity (the low-temperature discharge capacity of the conventional lithium ion battery is only 50 percent or less), the pull-down voltage is higher than 2.5V (the low-temperature pull-down voltage of the conventional lithium ion battery is only 2.2V or less), and the normal use and the safe use under the extreme low-temperature condition are met.
The above-mentioned contents are only for illustrating the technical idea of the present invention, and the protection scope of the present invention is not limited thereby, and any modification made on the basis of the technical idea of the present invention falls within the protection scope of the claims of the present invention.
Claims (10)
1. An overcharge-prevention low-temperature electrolyte is characterized by comprising an organic solvent, lithium salt, a low-resistance film forming additive and an overcharge-prevention additive;
wherein the organic solvent comprises a carbonate solvent and a linear carboxylate solvent; the lithium salt comprises one or more of lithium hexafluorophosphate, lithium difluorophosphate, lithium tetrafluoroborate and lithium difluorooxalato borate; the low-impedance film forming additive is at least two of vinylene carbonate, 1, 3-propane sultone and ethylene sulfite; the anti-overcharging additive is 1, 4-di-tert-butyl-2, 5 dimethoxybenzene;
wherein, the organic solvent is 78 wt% -82 wt%, the lithium salt is 15 wt% -18 wt%, the anti-overcharging additive is 1 wt% -2 wt%, and the rest is low-impedance film forming additive.
2. The overcharge-preventing low-temperature electrolyte solution of claim 1, wherein the carbonate-based solvent is a combination of at least two cyclic carbonates and at least two chain carbonates of ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate and methyl ethylene carbonate.
3. The overcharge-prevention low-temperature electrolyte solution of claim 2, wherein the chain carbonate is diethyl carbonate and methylethyl carbonate, and the chain carbonate is 15 wt% to 20 wt%;
the cyclic carbonate is a mixture of ethylene carbonate and propylene carbonate, and the cyclic carbonate is 25 wt% -30 wt%.
4. The anti-overcharge low-temperature electrolyte solution of claim 1, wherein the linear carboxylate solvent is at least one of ethyl acetate, propyl acetate and ethyl propionate.
5. The overcharge-preventing low-temperature electrolyte solution of claim 4, wherein the linear carboxylic acid ester is ethyl acetate and the linear carboxylic acid ester is 35 to 40 wt%.
6. The overcharge-resistant cryogenic electrolyte of claim 1 wherein the lithium salt is a mixture of lithium hexafluorophosphate and lithium tetrafluoroborate.
7. The overcharge-resistant cryogenic electrolyte of claim 6 wherein the lithium hexafluorophosphate is present in an amount of 14 to 16 wt% and the lithium tetrafluoroborate is present in an amount of 1 to 4 wt%.
8. The overcharge-resistant cryogenic electrolyte of claim 1 wherein the low resistance film-forming additive is a blend of vinylene carbonate, 1, 3-propane sultone and vinyl sulfite.
9. The overcharge-resistant cryogenic electrolyte of claim 8 wherein the low resistance film-forming additive is present in the range of 2 to 4 wt%.
10. A lithium ion battery comprising a positive electrode sheet, a separator, a negative electrode sheet and the overcharge-preventing low-temperature electrolyte solution according to any one of claims 1 to 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110594221.6A CN113140799A (en) | 2021-05-28 | 2021-05-28 | Overcharge-prevention low-temperature electrolyte and lithium ion battery based on same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110594221.6A CN113140799A (en) | 2021-05-28 | 2021-05-28 | Overcharge-prevention low-temperature electrolyte and lithium ion battery based on same |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113140799A true CN113140799A (en) | 2021-07-20 |
Family
ID=76815980
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110594221.6A Pending CN113140799A (en) | 2021-05-28 | 2021-05-28 | Overcharge-prevention low-temperature electrolyte and lithium ion battery based on same |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113140799A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114171782A (en) * | 2021-12-07 | 2022-03-11 | 河南省法恩莱特新能源科技有限公司 | Overcharge-resistant sodium ion battery electrolyte and preparation method thereof |
| CN114284561A (en) * | 2022-01-05 | 2022-04-05 | 合肥国轩高科动力能源有限公司 | Electrolyte overcharge-preventing additive, electrolyte containing additive and lithium secondary battery |
| EP4178001A4 (en) * | 2021-09-24 | 2023-10-11 | Contemporary Amperex Technology Co., Limited | Lithium ion battery, battery module, battery pack, and electric device |
| CN117855608A (en) * | 2024-03-07 | 2024-04-09 | 宁德新能源科技有限公司 | Electrolyte, secondary battery, and electronic device |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102082297A (en) * | 2010-12-30 | 2011-06-01 | 东莞市杉杉电池材料有限公司 | Electrolyte for lithium iron phosphate power lithium ion battery |
| CN108511802A (en) * | 2018-06-04 | 2018-09-07 | 东莞市杉杉电池材料有限公司 | A kind of lithium-ion-power cell Overcharge prevention electrolyte and lithium-ion-power cell |
| CN111048835A (en) * | 2019-12-05 | 2020-04-21 | 广东维都利新能源有限公司 | Overcharge-resistant electrolyte, secondary lithium battery adopting electrolyte and preparation method of overcharge-resistant electrolyte |
-
2021
- 2021-05-28 CN CN202110594221.6A patent/CN113140799A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102082297A (en) * | 2010-12-30 | 2011-06-01 | 东莞市杉杉电池材料有限公司 | Electrolyte for lithium iron phosphate power lithium ion battery |
| CN108511802A (en) * | 2018-06-04 | 2018-09-07 | 东莞市杉杉电池材料有限公司 | A kind of lithium-ion-power cell Overcharge prevention electrolyte and lithium-ion-power cell |
| CN111048835A (en) * | 2019-12-05 | 2020-04-21 | 广东维都利新能源有限公司 | Overcharge-resistant electrolyte, secondary lithium battery adopting electrolyte and preparation method of overcharge-resistant electrolyte |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP4178001A4 (en) * | 2021-09-24 | 2023-10-11 | Contemporary Amperex Technology Co., Limited | Lithium ion battery, battery module, battery pack, and electric device |
| CN114171782A (en) * | 2021-12-07 | 2022-03-11 | 河南省法恩莱特新能源科技有限公司 | Overcharge-resistant sodium ion battery electrolyte and preparation method thereof |
| CN114284561A (en) * | 2022-01-05 | 2022-04-05 | 合肥国轩高科动力能源有限公司 | Electrolyte overcharge-preventing additive, electrolyte containing additive and lithium secondary battery |
| CN117855608A (en) * | 2024-03-07 | 2024-04-09 | 宁德新能源科技有限公司 | Electrolyte, secondary battery, and electronic device |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111640986B (en) | High-safety electrolyte suitable for high-energy-density lithium ion battery | |
| CN110707361B (en) | Electrolyte for high-voltage soft-package lithium ion battery suitable for high-rate charge and discharge | |
| US11367898B2 (en) | Electrolyte and lithium ion battery including the same | |
| CN102522590B (en) | Non-aqueous organic electrolyte, lithium ion secondary battery containing non-aqueous organic electrolyte, preparation method of lithium ion secondary battery and terminal communication equipment | |
| CN113140799A (en) | Overcharge-prevention low-temperature electrolyte and lithium ion battery based on same | |
| CN102544586B (en) | preparation method of lithium ion battery and lithium ion battery | |
| CN111653829A (en) | Lithium ion battery electrolyte and lithium ion battery | |
| CN111883839B (en) | High-voltage electrolyte and lithium ion battery based on same | |
| CN104600362A (en) | Power battery and lithium ion electrolyte thereof | |
| CN109659496A (en) | A kind of lithium ion cell positive film and its preparation and application | |
| CN110336075B (en) | Electrolyte solution, electrochemical device and electronic device comprising same | |
| CN102394314A (en) | Lithium ion battery electrolyte and lithium ion secondary battery | |
| US20230275269A1 (en) | Electrolyte and electrochemical apparatus | |
| CN109888384B (en) | Electrolyte and battery containing the same | |
| CN104466248A (en) | Electrolyte of lithium ion battery and lithium ion battery utilizing same | |
| CN113839095B (en) | Electrolyte and battery comprising same | |
| CN115810799A (en) | High-performance lithium metal battery electrolyte and high-performance lithium metal battery | |
| CN112349961A (en) | Electrolyte solution, electrochemical device and electronic apparatus including the same | |
| CN104508891A (en) | Non-aqueous electrolyte secondary cell | |
| US20230026621A1 (en) | Secondary battery | |
| CN111987362A (en) | Lithium ion battery electrolyte and preparation method and application thereof | |
| CN113889667B (en) | High-voltage electrolyte adaptive to lithium cobaltate battery capable of being charged quickly and application of high-voltage electrolyte | |
| CN112838269B (en) | Electrolyte solution, electrochemical device and electronic apparatus including the same | |
| CN111864266B (en) | High-voltage lithium ion battery electrolyte additive and electrolyte thereof | |
| CN102593514A (en) | Additive for high-voltage electrolyte of lithium ion battery and electrolyte containing same |
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 | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20210720 |