CN113948767A - Preparation method of safe lithium battery electrolyte containing microcapsule body and lithium battery - Google Patents
Preparation method of safe lithium battery electrolyte containing microcapsule body and lithium battery Download PDFInfo
- Publication number
- CN113948767A CN113948767A CN202111217870.0A CN202111217870A CN113948767A CN 113948767 A CN113948767 A CN 113948767A CN 202111217870 A CN202111217870 A CN 202111217870A CN 113948767 A CN113948767 A CN 113948767A
- Authority
- CN
- China
- Prior art keywords
- lithium battery
- microcapsule
- electrolyte
- preparing
- microcapsule body
- 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.)
- Granted
Links
- 239000003094 microcapsule Substances 0.000 title claims abstract description 117
- 229910052744 lithium Inorganic materials 0.000 title claims abstract description 106
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 title claims abstract description 105
- 239000003792 electrolyte Substances 0.000 title claims abstract description 90
- 238000002360 preparation method Methods 0.000 title claims abstract description 17
- 229920001807 Urea-formaldehyde Polymers 0.000 claims abstract description 25
- GZCGUPFRVQAUEE-SLPGGIOYSA-N aldehydo-D-glucose Chemical compound OC[C@@H](O)[C@@H](O)[C@H](O)[C@@H](O)C=O GZCGUPFRVQAUEE-SLPGGIOYSA-N 0.000 claims abstract description 23
- 238000000034 method Methods 0.000 claims abstract description 16
- WSFSSNUMVMOOMR-UHFFFAOYSA-N Formaldehyde Chemical compound O=C WSFSSNUMVMOOMR-UHFFFAOYSA-N 0.000 claims description 27
- WVSNNWIIMPNRDB-UHFFFAOYSA-N 1,1,1,3,3,4,4,5,5,6,6,6-dodecafluorohexan-2-one Chemical compound FC(F)(F)C(=O)C(F)(F)C(F)(F)C(F)(F)C(F)(F)F WVSNNWIIMPNRDB-UHFFFAOYSA-N 0.000 claims description 25
- 238000003756 stirring Methods 0.000 claims description 24
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims description 16
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 claims description 16
- 239000004202 carbamide Substances 0.000 claims description 16
- 229920000877 Melamine resin Polymers 0.000 claims description 13
- 238000001035 drying Methods 0.000 claims description 12
- 239000000243 solution Substances 0.000 claims description 11
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 claims description 10
- JDSHMPZPIAZGSV-UHFFFAOYSA-N melamine Chemical compound NC1=NC(N)=NC(N)=N1 JDSHMPZPIAZGSV-UHFFFAOYSA-N 0.000 claims description 10
- 239000002245 particle Substances 0.000 claims description 9
- 229910013872 LiPF Inorganic materials 0.000 claims description 8
- 229910001290 LiPF6 Inorganic materials 0.000 claims description 8
- 101150058243 Lipf gene Proteins 0.000 claims description 8
- 239000007864 aqueous solution Substances 0.000 claims description 8
- GVGUFUZHNYFZLC-UHFFFAOYSA-N dodecyl benzenesulfonate;sodium Chemical compound [Na].CCCCCCCCCCCCOS(=O)(=O)C1=CC=CC=C1 GVGUFUZHNYFZLC-UHFFFAOYSA-N 0.000 claims description 8
- 239000007788 liquid Substances 0.000 claims description 8
- 229940080264 sodium dodecylbenzenesulfonate Drugs 0.000 claims description 8
- 230000001502 supplementing effect Effects 0.000 claims description 8
- 238000005406 washing Methods 0.000 claims description 8
- 229910021383 artificial graphite Inorganic materials 0.000 claims description 7
- 239000002131 composite material Substances 0.000 claims description 7
- 229910016722 Ni0.5Co0.2Mn0.3 Inorganic materials 0.000 claims description 6
- 239000002904 solvent Substances 0.000 claims description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 6
- 239000004698 Polyethylene Substances 0.000 claims description 5
- 229920000573 polyethylene Polymers 0.000 claims description 5
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 claims description 4
- GSEJCLTVZPLZKY-UHFFFAOYSA-N Triethanolamine Chemical compound OCCN(CCO)CCO GSEJCLTVZPLZKY-UHFFFAOYSA-N 0.000 claims description 4
- 238000007865 diluting Methods 0.000 claims description 4
- 239000012153 distilled water Substances 0.000 claims description 4
- 230000001804 emulsifying effect Effects 0.000 claims description 4
- 238000001914 filtration Methods 0.000 claims description 4
- 238000010438 heat treatment Methods 0.000 claims description 4
- 229910001416 lithium ion Inorganic materials 0.000 claims description 4
- 239000006228 supernatant Substances 0.000 claims description 4
- 238000002156 mixing Methods 0.000 claims description 3
- 239000008151 electrolyte solution Substances 0.000 claims description 2
- 230000008569 process Effects 0.000 abstract description 5
- 238000011031 large-scale manufacturing process Methods 0.000 abstract description 3
- 239000010410 layer Substances 0.000 description 8
- 239000000463 material Substances 0.000 description 8
- 238000001816 cooling Methods 0.000 description 7
- 239000002775 capsule Substances 0.000 description 6
- 238000000354 decomposition reaction Methods 0.000 description 6
- 238000004880 explosion Methods 0.000 description 6
- 238000006116 polymerization reaction Methods 0.000 description 6
- 239000011358 absorbing material Substances 0.000 description 5
- 239000012782 phase change material Substances 0.000 description 4
- IDBYQQQHBYGLEQ-UHFFFAOYSA-N 1,1,2,2,3,3,4-heptafluorocyclopentane Chemical compound FC1CC(F)(F)C(F)(F)C1(F)F IDBYQQQHBYGLEQ-UHFFFAOYSA-N 0.000 description 3
- RNFJDJUURJAICM-UHFFFAOYSA-N 2,2,4,4,6,6-hexaphenoxy-1,3,5-triaza-2$l^{5},4$l^{5},6$l^{5}-triphosphacyclohexa-1,3,5-triene Chemical compound N=1P(OC=2C=CC=CC=2)(OC=2C=CC=CC=2)=NP(OC=2C=CC=CC=2)(OC=2C=CC=CC=2)=NP=1(OC=1C=CC=CC=1)OC1=CC=CC=C1 RNFJDJUURJAICM-UHFFFAOYSA-N 0.000 description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 3
- 229910052782 aluminium Inorganic materials 0.000 description 3
- 239000003054 catalyst Substances 0.000 description 3
- 239000011162 core material Substances 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000003063 flame retardant Substances 0.000 description 3
- 125000001153 fluoro group Chemical class F* 0.000 description 3
- 239000011888 foil Substances 0.000 description 3
- 238000011065 in-situ storage Methods 0.000 description 3
- -1 melamine modified urea-formaldehyde resin Chemical class 0.000 description 3
- 239000007784 solid electrolyte Substances 0.000 description 3
- 230000002378 acidificating effect Effects 0.000 description 2
- 230000004075 alteration Effects 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 230000006866 deterioration Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000004146 energy storage Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 239000000523 sample Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 238000006467 substitution reaction Methods 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 229910016739 Ni0.5Co0.2Mn0.3(OH)2 Inorganic materials 0.000 description 1
- 241000220317 Rosa Species 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000006555 catalytic reaction Methods 0.000 description 1
- 239000011247 coating layer Substances 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 239000013068 control sample Substances 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- HANVTCGOAROXMV-UHFFFAOYSA-N formaldehyde;1,3,5-triazine-2,4,6-triamine;urea Chemical compound O=C.NC(N)=O.NC1=NC(N)=NC(N)=N1 HANVTCGOAROXMV-UHFFFAOYSA-N 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 150000002641 lithium Chemical class 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- WSFSSNUMVMOOMR-NJFSPNSNSA-N methanone Chemical compound O=[14CH2] WSFSSNUMVMOOMR-NJFSPNSNSA-N 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 238000000879 optical micrograph Methods 0.000 description 1
- 238000013021 overheating Methods 0.000 description 1
- 238000001878 scanning electron micrograph Methods 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 239000004094 surface-active agent Substances 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
- H01M10/0565—Polymeric materials, e.g. gel-type or solid-type
-
- 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
-
- 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)
- Dispersion Chemistry (AREA)
- General Physics & Mathematics (AREA)
- Inorganic Chemistry (AREA)
- Secondary Cells (AREA)
- Battery Electrode And Active Subsutance (AREA)
Abstract
The invention relates to the technical field of lithium batteries, and discloses a preparation method of a safe lithium battery electrolyte containing a microcapsule body and a lithium battery thereof, wherein the preparation method comprises the following steps: s1) preparing a water-soluble urea-formaldehyde resin prepolymer; s2) preparing microcapsules containing a wrapping film; s3) preparing a microcapsule body; s4) preparing the safe lithium battery electrolyte containing the microcapsule body; the safe lithium battery electrolyte containing the microcapsule body has the advantages of simple and efficient process, strong practicability and low replacement cost of the electrolyte, and is suitable for large-scale production of lithium batteries; according to the lithium battery prepared by using the electrolyte prepared by the preparation method, the potential safety hazard in the lithium battery can be effectively inhibited when the lithium battery using the safe lithium battery electrolyte containing the microcapsule body is out of control due to heat.
Description
Technical Field
The invention relates to the technical field of lithium batteries, in particular to a preparation method of a safe lithium battery electrolyte containing a microcapsule body and a lithium battery.
Background
The lithium battery is a new energy source for energy storage widely popularized at present, has the advantages of high working voltage, high specific energy, high energy utilization rate, long cycle life and the like, and is widely applied to the fields of portable electronic equipment, electric automobiles, energy storage systems and the like.
Lithium cell conflagration is endogenous conflagration, and when the lithium cell thermal runaway took place, when the temperature rise constantly rose, decomposition reaction can take place for electrolyte to produce a large amount of combustible gas, and then initiate the burning explosion.
The solution in the prior art is that a solvent with high thermal stability is selected as an electrolyte solvent to be used, and a flame retardant is added into the electrolyte to further improve the flame retardant property of the electrolyte. The solutions belong to passive protection strategies, can only improve the heat resistance of the lithium battery, but cannot ensure that the thermal runaway of the lithium battery does not continuously deteriorate, and avoid the occurrence of combustion explosion. Moreover, the flame retardant additive can affect the electrochemical performance of the lithium battery, and the electrolyte solvent with high thermal stability has high cost.
Disclosure of Invention
Based on the existing technical defects, the invention provides a preparation method of a safe lithium battery electrolyte containing a microcapsule body, wherein the microcapsule body contained in the electrolyte can inhibit the thermal runaway of a lithium battery, can avoid the internal structure of the battery from being damaged, and can prevent a fire disaster or an explosion accident of a battery system.
Another object of the present invention is to provide a lithium battery prepared using the electrolyte obtained by the above preparation method, the prepared lithium battery having a function of suppressing thermal runaway deterioration.
In order to achieve the purpose, the invention adopts the following technical scheme:
a preparation method of a safe lithium battery electrolyte containing microcapsule bodies comprises the following steps:
s1) adding formaldehyde into urea, stirring until urea particles are completely dissolved, adjusting the pH value of the system, adding melamine, and reacting for 1h at the temperature of 60-70 ℃ under the stirring condition of 400rpm to obtain a water-soluble urea-formaldehyde resin prepolymer;
s2) adding the water-soluble urea-formaldehyde resin prepolymer into sodium dodecyl benzene sulfonate aqueous solution, diluting and stirring, adding perfluorohexanone liquid, stirring and emulsifying for 30min, stirring at 45-55 ℃, dropwise adding 1% sulfuric acid solution, acidifying and adjusting the pH value of the system, heating to 55-65 ℃, adding a small amount of distilled water, curing for 2h, washing, standing, removing supernatant, and preparing microcapsules containing a wrapping film;
s3) supplementing the water-soluble urea-formaldehyde resin prepolymer to the microcapsule containing the wrapping film, repeating the step S2) for 2-3 times to obtain a microcapsule containing multiple layers of wrapping films, washing the microcapsule containing multiple layers of wrapping films with acetone, filtering and drying to obtain a microcapsule body;
s4) LiPF commercially available6Concentration 1mol/l, volume concentration ratio of EC and DMC l: l LiPF of 6Adding the microcapsule body into commercial electrolyte of/EC + DMC, and supplementing and adding LiPF6And keeping the concentration of lithium ions in the electrolyte at a constant value of 1mol/l to prepare the safe lithium battery electrolyte containing the microcapsule body.
Preferably, in the step S1), the mixing mass ratio of the urea and the formaldehyde is 1: 2, and the mass ratio of the added melamine to the urea is 0.05: 1.
Preferably, in step S1), the solvent for adjusting pH is triethanolamine, and the pH of the solution is 7-8.
Preferably, in step S2), the stirring speed is 600r/min, and the pH value is 2-3.
Preferably, in step S2), the mass concentration of the perfluorohexanone in the aqueous solution is 0.8-1g/ml, the mass concentration of the sodium dodecylbenzenesulfonate is 0.4-0.5 wt%, and the mass concentration of the water-soluble urea-formaldehyde resin prepolymer is 2-2.5 g/ml.
Preferably, in the step S3), the mass concentration of the supplemented water-soluble urea-formaldehyde resin prepolymer is 1-1.5 g/ml.
Preferably, in step S3), the drying temperature is 60 ℃ and the drying time is 12 h.
Preferably, step S4), addingThe mass of the microcapsule body is LiPF615-40% of the mass of the commercial electrolyte/EC + DMC.
The invention further provides a lithium battery of the safe lithium battery electrolyte prepared by using the preparation method of the safe lithium battery electrolyte containing the microcapsule body, which comprises a Ni0.5Co0.2Mn0.3 positive electrode and an artificial graphite negative electrode, wherein the electrolyte is the safe lithium battery electrolyte containing the microcapsule body, a polypropylene-polyethylene composite diaphragm is arranged between the Ni0.5Co0.2Mn0.3 positive electrode and the artificial graphite negative electrode, the rupture temperature of a film layer of the microcapsule body is 120 +/-5 ℃, and the particle size of the microcapsule body is 5-10 mu m.
The technical scheme of the invention has the beneficial effects that: the preparation method of the safe lithium battery electrolyte containing the microcapsule body adopts an in-situ polymerization method, takes low-melting-point liquid perfluorohexanone as a capsule core material, melamine modified urea-formaldehyde resin as a capsule wall material and sulfuric acid as a catalyst to prepare the perfluorohexanone/MUF microcapsule, and the microcapsule body is formed by multiple times of wrapping; the prepared microcapsule body is wrapped by a heat-absorbing phase-change material (fluorine derivatives, such as perfluorohexanone or heptafluorocyclopentane), at the initial stage of thermal runaway of a lithium battery, the temperature in the battery can be increased due to the decomposition of an SEI solid electrolyte interface film, the electrolyte can be decomposed when the temperature is increased to over 150 ℃, and further a diaphragm in the electrolyte can be melted.
Furthermore, the invention provides a lithium battery using the safe lithium battery electrolyte containing the microcapsule body, when the prepared lithium battery is out of control thermally, the contained composite diaphragm can be broken at 120 +/-5 ℃ and releases heat-absorbing materials, the lithium battery has a good protection function of actively cooling, the potential safety hazard in the lithium battery can be effectively inhibited, the process is simple and efficient, the practicability is high, the replacement cost of the electrolyte is low, and the lithium battery is suitable for large-scale production of the lithium battery.
Drawings
FIG. 1 is an optical micrograph of a microcapsule according to one embodiment of the present invention;
FIG. 2 is a scanning electron micrograph of the microcapsule of FIG. 1;
fig. 3 is a schematic view illustrating a structure of a lithium battery including an electrolyte for a safety lithium battery using microcapsules according to an embodiment of the present invention;
FIG. 4 is a photograph of a sample for a lithium battery with a soft pack using a safe lithium battery electrolyte containing microcapsules;
fig. 5 is a thermal runaway test chart of a lithium battery with a soft pack using a safety lithium battery electrolyte containing a microcapsule body and a lithium battery using a commercial electrolyte according to an embodiment of the present invention.
Detailed Description
In the description herein, references to the description of the terms "embodiment," "example," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
While embodiments of the invention have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.
The technical solution of the present invention will be further described with reference to the following embodiments.
A preparation method of a safe lithium battery electrolyte containing microcapsule bodies comprises the following steps:
s1) adding formaldehyde into urea, stirring until urea particles are completely dissolved, adjusting the pH value of the system, adding melamine, and reacting for 1h at the temperature of 60-70 ℃ under the stirring condition of 400rpm to obtain a water-soluble urea-formaldehyde resin prepolymer;
s2) adding the water-soluble urea-formaldehyde resin prepolymer into sodium dodecyl benzene sulfonate aqueous solution, diluting and stirring, adding perfluorohexanone liquid, stirring and emulsifying for 30min, stirring at 45-55 ℃, dropwise adding 1% sulfuric acid solution, acidifying and adjusting the pH value of the system, heating to 55-65 ℃, adding a small amount of distilled water, curing for 2h, washing, standing, removing supernatant, and preparing microcapsules containing a wrapping film;
S3) supplementing the water-soluble urea-formaldehyde resin prepolymer to the microcapsule containing the wrapping film, repeating the step S2) for 2-3 times to obtain a microcapsule containing multiple layers of wrapping films, washing the microcapsule containing multiple layers of wrapping films with acetone, filtering and drying to obtain a microcapsule body;
s4) LiPF commercially available6Concentration 1mol/l, volume concentration ratio of EC and DMC l: l LiPF of6Adding the microcapsule body into commercial electrolyte of/EC + DMC, and supplementing and adding LiPF6And keeping the concentration of lithium ions in the electrolyte at a constant value of 1mol/l to prepare the safe lithium battery electrolyte containing the microcapsule body.
The preparation method of the safe lithium battery electrolyte containing the microcapsule body adopts an in-situ polymerization method, takes low-melting-point liquid perfluorohexanone as a capsule core material, melamine modified urea-formaldehyde resin as a capsule wall material and sulfuric acid as a catalyst to prepare the perfluorohexanone/MUF microcapsule, and the microcapsule body is formed by multiple times of wrapping; the prepared microcapsule body is wrapped by a heat-absorbing phase-change material (fluorine derivatives, such as perfluorohexanone or heptafluorocyclopentane), at the initial stage of thermal runaway of a lithium battery, the temperature in the battery can be increased due to the decomposition of an SEI solid electrolyte interface film, the electrolyte can be decomposed when the temperature is increased to over 150 ℃, and further a diaphragm in the electrolyte can be melted. Therefore, when the safe lithium battery electrolyte containing the microcapsule body is used, the contained microcapsule body can break and release heat-absorbing materials when the lithium battery is out of control due to heat, the safe lithium battery electrolyte containing the microcapsule body has a good protection function of actively cooling, can effectively inhibit potential safety hazards inside the lithium battery, prevents open fire or explosion during the out of control due to heat of the lithium battery, and provides a new solution for safe application of the lithium battery and replacement of the electrolyte.
Preferably, in the step S1), the mixing mass ratio of the urea and the formaldehyde is 1: 2, and the mass ratio of the added melamine to the urea is 0.05: 1.
Urea, melamine and formaldehyde are polymerized to form urea-formaldehyde resin, and the melamine contained in the modified urea-formaldehyde resin can effectively reduce the content of free formaldehyde, so that the electrolyte has better use safety.
Preferably, in step S1), the solvent for adjusting pH is triethanolamine, and the pH of the solution is 7-8.
Under the alkaline environment, the polymerization efficiency of urea, melamine and formaldehyde is higher.
Preferably, in step S2), the stirring speed is 600r/min, and the pH value is 2-3.
The microcapsule coating needs to be completed in an acid environment, the pH value is proper to be 2-3, and the coating layer of the microcapsule cannot be formed when the pH value is too high or too low.
Under the acidic environment, stirring at a medium speed of 600r/min, and adding sulfuric acid for catalysis can improve the film forming efficiency of the prepolymer and the efficiency of wrapping perfluorohexanone.
Preferably, in step S2), the mass concentration of the perfluorohexanone in the aqueous solution is 0.8-1g/ml, the mass concentration of the sodium dodecylbenzenesulfonate is 0.4-0.5 wt%, and the mass concentration of the water-soluble urea-formaldehyde resin prepolymer is 2-2.5 g/ml.
The sodium dodecyl benzene sulfonate is a surfactant, so that the perfluorohexanone in the aqueous solution can be dispersed more uniformly, the concentration of the perfluorohexanone wrapped by each microcapsule formed by the urea resin film is close to each other, relatively consistent temperature resistance is further formed, and the perfluorohexanone released after the microcapsules are broken has the same cooling effect.
Preferably, in the step S3), the mass concentration of the supplemented water-soluble urea-formaldehyde resin prepolymer is 1-1.5 g/ml.
In the repeated wrapping and film forming process of the step S3), the supplemented water-soluble urea-formaldehyde resin prepolymer is about half of the total amount of the water-soluble urea-formaldehyde resin prepolymer which is added for the first time, so that the urea-formaldehyde resin prepolymer is maintained at a high concentration.
In the repeated coating and film forming process, a second film layer and a third film layer are formed, and a heat-absorbing phase-change material perfluorohexanone is coated between the second film layer and the third film layer, so that the cooling performance of the microcapsule body is further improved.
Preferably, in step S3), the drying temperature is 60 ℃ and the drying time is 12 h.
The microcapsule body is cleaned by acetone, so that the dried microcapsule body does not contain acidic substances or other impurities, and the problem that the performance of the lithium battery is damaged due to chemical reaction with other substances in electrolyte when the microcapsule body is used for the lithium battery is avoided.
Drying at 60 deg.C for 12 hr can completely remove water on microcapsule surface, such as deformation of microcapsule due to temperature higher than 65 deg.C, and incomplete removal of water due to low drying efficiency.
Preferably, in step S4), the mass of the microcapsule body added is LiPF615-40% of the mass of the commercial electrolyte/EC + DMC.
When the content of the added microcapsule body is less than 15 wt%, the total amount of the heat-absorbing material perfluorohexanone released by the microcapsule body is relatively small, the cooling effect is insufficient, and the thermal runaway temperature of the lithium battery can still continue to rise; when the added amount of the microcapsule body exceeds 40 wt%, the proportion of the microcapsule body is too high, which may affect the fluidity and working performance of the electrolyte.
The invention further provides a lithium battery of the safe lithium battery electrolyte prepared by using the preparation method of the safe lithium battery electrolyte containing the microcapsule body, which comprises a Ni0.5Co0.2Mn0.3 positive electrode and an artificial graphite negative electrode, wherein the electrolyte is the safe lithium battery electrolyte containing the microcapsule body, a polypropylene-polyethylene composite diaphragm is arranged between the Ni0.5Co0.2Mn0.3 positive electrode and the artificial graphite negative electrode, the rupture temperature of a film layer of the microcapsule body is 120 +/-5 ℃, and the particle size of the microcapsule body is 5-10 mu m.
The above lithium battery, LiPF, using the electrolyte for a safety lithium battery containing a microcapsule body6The endothermic decomposition temperature of the/EC + DMC electrolyte is 150-160 ℃, when the thermal runaway phenomenon occurs in the lithium battery, the temperature of the electrolyte rises along with the rise, when the temperature reaches 120 +/-5 ℃, the urea-melamine-formaldehyde polymerization film layer in the microcapsule body is broken, the endothermic material perfluorohexanone wrapped by the polymerization film layer is released into the electrolyte, and the temperature of the electrolyte is rapidly reduced, thereby avoiding the fire and even explosion of the lithium battery of the safe lithium battery electrolyte containing the microcapsule body due to overheating.
In the embodiment of the present invention shown in the top scanning electron microscope view of fig. 2, the microcapsule bodies have a particle size of 5 to 10 μm.
Examples
1. The preparation of the microcapsule bodies of the present example, and the assembly of the lithium battery were carried out according to the following steps:
s1) adding 2000g of formaldehyde into 1000g of urea, stirring until urea particles are completely dissolved, adjusting the pH value of the system to 7.6 by using triethanolamine, adding 50g of melamine, and stirring at 70 ℃ and 400rpm for reaction for 1h to obtain the water-soluble urea-formaldehyde resin prepolymer.
S2) adding 110g of the water-soluble urea-formaldehyde resin prepolymer into 500ml of sodium dodecyl benzene sulfonate aqueous solution with the mass concentration of 0.5%, diluting and stirring, then adding 50g of perfluorohexanone liquid, stirring and emulsifying for 30min, then stirring at 45 ℃, at the rotating speed of 600rpm, dropwise adding 1% sulfuric acid solution, acidifying and adjusting the pH value of the system to be 2.8, then heating to 55 ℃, adding a small amount of distilled water, curing for 2h, washing, standing, pouring out supernatant liquid, and preparing the microcapsule containing the wrapping film.
S3) supplementing 55g of the water-soluble urea-formaldehyde resin prepolymer to the microcapsule containing the wrapping film, repeating the step S2) for 2-3 times to obtain the microcapsule containing multiple layers of wrapping films, washing with acetone, filtering, and drying at 60 ℃ for 12h to obtain the microcapsule body.
S4) at a commercial LiPF6 concentration of 1mol/l, a volume concentration ratio of EC to DMC of l: l LiPF of6Adding the microcapsule body accounting for 30 percent of the mass of the commercial electrolyte into the commercial electrolyte of the/EC + DMC, and supplementing and adding LiPF6And keeping the concentration of lithium ions in the electrolyte at a constant value of 1mol/l to prepare the safe lithium battery electrolyte containing the microcapsule body.
S5) assembling a lithium battery: with Ni0.5Co0.2Mn0.3(OH)2And the artificial graphite is used as a positive electrode, the safe lithium battery electrolyte containing the microcapsule body is added, and the positive electrode and the negative electrode are isolated by a polypropylene-polyethylene composite diaphragm to assemble the lithium battery with the aluminum foil flexible package and the sealing performance.
2. Observing the microcapsule body obtained in step S3) with an optical microscope, wherein the physical photograph in the microscope is shown in FIG. 1, and the microcapsule body obtained is seen to have a relatively standard spherical structure, and the particle diameter of the microcapsule body is measured to be 5-10 μm.
3. Observing the microcapsule body prepared in the step S3) by using a scanning electron microscope to obtain a scanning electron microscope photo as shown in figure 2, wherein the distribution of the microcapsule body is relative to each other and the defects of interface gaps and the like which influence the performance of the diaphragm do not exist in the photo.
4. The photo of the lithium battery sealed in the aluminum foil flexible package obtained in the step S5) is shown in fig. 4, the internal structure is shown in the schematic diagram of fig. 3, the electrode on the left side in the diagram is the positive electrode, the electrode on the right side is the graphite electrode, a diaphragm is arranged in the middle, the electrolyte is filled between the two sides of the diaphragm and the electrodes, and the microcapsules obtained in the step S3) are distributed in the electrolyte.
5. The aluminum foil film soft pack lithium battery assembled in step S5) was used as a test sample, and a thermal runaway test was performed to verify the reliability of the lithium battery using the same packaged soft pack lithium battery using the above commercial electrolyte solution without microcapsules as a control sample, the result of which is shown in fig. 5. The solid line in the figure represents the temperature-time change curve of the flexible package lithium battery of the commercial electrolyte without the microcapsule body, the dotted line represents the temperature-time change curve of the flexible package lithium battery of the safe lithium battery electrolyte containing the microcapsule body, and the trend of the solid line and the dotted line in the figure shows that when the battery temperature reaches 85 ℃, the polypropylene-polyethylene composite membrane is melted and decomposed, the positive electrode and the negative electrode in the battery are short-circuited, a large amount of heat is generated instantaneously, the temperature in the battery rises rapidly, the battery can be subjected to fire explosion, and the temperature rises rapidly and soaks to 700 ℃, as shown by the crest curve of the surrounding area II in the figure. When the temperature of the battery reaches 120 ℃, the microcapsule body of the soft-package lithium battery using the microcapsule body can be automatically broken out to release the perfluorohexanone, instantly absorb the heat in the battery and play a role in cooling the battery, so that the temperature curve does not rise but quickly falls, the temperature curve is quickly cooled to room temperature to form a horizontal straight line, and the inside of the battery does not catch fire or explode. The safe lithium battery electrolyte containing the microcapsule body disclosed by the invention has the advantages that the microcapsule body can be broken at the temperature of 120-130 ℃ to release heat-absorbing material perfluorohexanone, so that a large amount of heat in the electrolyte can be rapidly absorbed, the further deterioration of thermal runaway can be prevented, the decomposition of the electrolyte and the melting of a diaphragm can be avoided, the effect is obvious, and the reliability is high.
In summary, the preparation method of the safe lithium battery electrolyte containing the microcapsule body adopts an in-situ polymerization method, takes low-melting-point liquid perfluorohexanone as a capsule core material, melamine modified urea resin as a capsule wall material and sulfuric acid as a catalyst to prepare the perfluorohexanone/MUF microcapsule, and the microcapsule body is formed by multiple times of wrapping; the prepared microcapsule body is wrapped by a heat-absorbing phase-change material (fluorine derivatives, such as perfluorohexanone or heptafluorocyclopentane), at the initial stage of thermal runaway of a lithium battery, the temperature in the battery can be increased due to the decomposition of an SEI solid electrolyte interface film, the electrolyte can be decomposed when the temperature is increased to over 150 ℃, and further a diaphragm in the electrolyte can be melted.
Furthermore, the invention provides a lithium battery using the safe lithium battery electrolyte containing the microcapsule body, when the prepared lithium battery is out of control thermally, the contained composite diaphragm can be broken at 120 +/-5 ℃ and releases heat-absorbing materials, the lithium battery has a good protection function of actively cooling, the potential safety hazard in the lithium battery can be effectively inhibited, the process is simple and efficient, the practicability is high, the replacement cost of the electrolyte is low, and the lithium battery is suitable for large-scale production of the lithium battery.
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples" or the like mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
While embodiments of the invention have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.
The technical principle of the present invention is described above in connection with specific embodiments. The description is only intended to explain the principles of the invention; and should not be construed as limiting the scope of the invention in any way. Based on the explanations herein; other embodiments of the invention will occur to those skilled in the art without the exercise of inventive faculty; all of which fall within the scope of the present invention.
Claims (9)
1. A preparation method of a safe lithium battery electrolyte containing microcapsule bodies is characterized by comprising the following steps:
s1) adding formaldehyde into urea, stirring until urea particles are completely dissolved, adjusting the pH value of the system, adding melamine, and reacting for 1h at the temperature of 60-70 ℃ under the stirring condition of 400rpm to obtain a water-soluble urea-formaldehyde resin prepolymer;
s2) adding the water-soluble urea-formaldehyde resin prepolymer into sodium dodecyl benzene sulfonate aqueous solution, diluting and stirring, adding perfluorohexanone liquid, stirring and emulsifying for 30min, stirring at 45-55 ℃, dropwise adding 1% sulfuric acid solution, acidifying and adjusting the pH value of the system, heating to 55-65 ℃, adding a small amount of distilled water, curing for 2h, washing, standing, removing supernatant, and preparing microcapsules containing a wrapping film;
s3) supplementing the water-soluble urea-formaldehyde resin prepolymer to the microcapsule containing the wrapping film, repeating the step S2) for 2-3 times to obtain a microcapsule containing multiple layers of wrapping films, washing the microcapsule containing multiple layers of wrapping films with acetone, filtering and drying to obtain a microcapsule body;
s4) LiPF commercially available6Concentration 1mol/l, volume concentration ratio of EC and DMC l: l LiPF of 6Adding the microcapsule body into commercial electrolyte of/EC + DMC, and supplementing and adding LiPF6And keeping the concentration of lithium ions in the electrolyte at a constant value of 1mol/l to prepare the safe lithium battery electrolyte containing the microcapsule body.
2. The method for preparing a safe lithium battery electrolyte containing microcapsule bodies as claimed in claim 1, wherein in step S1), the mixing mass ratio of urea and formaldehyde is 1: 2, and the mass ratio of added melamine to urea is 0.05: 1.
3. The method of claim 1, wherein the solvent for adjusting the pH in step S1) is triethanolamine, and the pH of the solution is 7 to 8.
4. The method for preparing a safe lithium battery electrolyte containing microcapsule bodies as claimed in claim 1, wherein the stirring speed is 600r/min and the pH is 2-3 in step S2).
5. The method for preparing the electrolyte of the safe lithium battery containing the microcapsule body as claimed in claim 1, wherein in step S2), the mass concentration of the perfluorohexanone in the aqueous solution is 0.8-1g/ml, the mass concentration of the sodium dodecylbenzenesulfonate is 0.4-0.5 wt%, and the mass concentration of the water-soluble urea-formaldehyde resin prepolymer is 2-2.5 g/ml.
6. The method for preparing the electrolyte of the safe lithium battery containing the microcapsule body as claimed in claim 1, wherein the mass concentration of the water-soluble urea resin prepolymer additionally added in the step S3) is 1-1.5 g/ml.
7. The method for preparing a safe lithium battery electrolyte containing microcapsule bodies as claimed in claim 1, wherein the drying temperature is 60 ℃ and the drying time is 12 hours in step S3).
8. The method for preparing a safe lithium battery electrolyte solution containing microcapsule according to claim 1, wherein the mass of the microcapsule added in step S4) is LiPF615-40% of the mass of the commercial electrolyte/EC + DMC.
9. A lithium battery using the safe lithium battery electrolyte prepared by the method for preparing the safe lithium battery electrolyte containing the microcapsule body as claimed in any one of claims 1 to 8, which comprises a ni0.5co0.2mn0.3 positive electrode and an artificial graphite negative electrode, wherein the electrolyte is the safe lithium battery electrolyte containing the microcapsule body, a polypropylene-polyethylene composite diaphragm is arranged between the ni0.5co0.2mn0.3 positive electrode and the artificial graphite negative electrode, the rupture temperature of the film layer of the microcapsule body is 120 ± 5 ℃, and the particle size of the microcapsule body is 5 to 10 μm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111217870.0A CN113948767B (en) | 2021-10-19 | 2021-10-19 | Preparation method of safe lithium battery electrolyte containing microcapsule and lithium battery |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111217870.0A CN113948767B (en) | 2021-10-19 | 2021-10-19 | Preparation method of safe lithium battery electrolyte containing microcapsule and lithium battery |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113948767A true CN113948767A (en) | 2022-01-18 |
| CN113948767B CN113948767B (en) | 2024-01-30 |
Family
ID=79331423
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111217870.0A Active CN113948767B (en) | 2021-10-19 | 2021-10-19 | Preparation method of safe lithium battery electrolyte containing microcapsule and lithium battery |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113948767B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115487460A (en) * | 2022-06-15 | 2022-12-20 | 浙江虹达特种橡胶制品有限公司杭州分公司 | Fire-proof and/or extinguishing material |
| CN116814221A (en) * | 2022-11-29 | 2023-09-29 | 广州纳诺新材料技术有限公司 | Phase-change microcapsule, high-safety lithium battery and preparation method thereof |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20140146934A (en) * | 2013-06-18 | 2014-12-29 | 주식회사 엘지화학 | Capsulated electrolyte having layer structure and method for preparation |
| JP2015097163A (en) * | 2013-11-15 | 2015-05-21 | トヨタ自動車株式会社 | Nonaqueous electrolyte secondary battery |
| CN105895959A (en) * | 2014-11-24 | 2016-08-24 | 深圳市沃特玛电池有限公司 | Method for improving needling safety performance of lithium ion battery |
| CN111378418A (en) * | 2018-12-27 | 2020-07-07 | 中信国安盟固利动力科技有限公司 | Preparation method of phase change microcapsule for improving safety of lithium battery |
| CN113193301A (en) * | 2021-03-31 | 2021-07-30 | 华中科技大学 | Fire extinguishing diaphragm for actively inhibiting thermal runaway of lithium battery and preparation method and application thereof |
| CN113181589A (en) * | 2021-03-22 | 2021-07-30 | 华中科技大学 | High-efficiency fire extinguishing agent and fire safety extinguishing process |
| CN113451664A (en) * | 2020-03-24 | 2021-09-28 | 东营市海科新源化工有限责任公司 | Thermally-excited active safety mechanism flame-retardant microcapsule, preparation method thereof and lithium ion battery |
-
2021
- 2021-10-19 CN CN202111217870.0A patent/CN113948767B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20140146934A (en) * | 2013-06-18 | 2014-12-29 | 주식회사 엘지화학 | Capsulated electrolyte having layer structure and method for preparation |
| JP2015097163A (en) * | 2013-11-15 | 2015-05-21 | トヨタ自動車株式会社 | Nonaqueous electrolyte secondary battery |
| CN105895959A (en) * | 2014-11-24 | 2016-08-24 | 深圳市沃特玛电池有限公司 | Method for improving needling safety performance of lithium ion battery |
| CN111378418A (en) * | 2018-12-27 | 2020-07-07 | 中信国安盟固利动力科技有限公司 | Preparation method of phase change microcapsule for improving safety of lithium battery |
| CN113451664A (en) * | 2020-03-24 | 2021-09-28 | 东营市海科新源化工有限责任公司 | Thermally-excited active safety mechanism flame-retardant microcapsule, preparation method thereof and lithium ion battery |
| CN113181589A (en) * | 2021-03-22 | 2021-07-30 | 华中科技大学 | High-efficiency fire extinguishing agent and fire safety extinguishing process |
| CN113193301A (en) * | 2021-03-31 | 2021-07-30 | 华中科技大学 | Fire extinguishing diaphragm for actively inhibiting thermal runaway of lithium battery and preparation method and application thereof |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115487460A (en) * | 2022-06-15 | 2022-12-20 | 浙江虹达特种橡胶制品有限公司杭州分公司 | Fire-proof and/or extinguishing material |
| CN115487460B (en) * | 2022-06-15 | 2023-07-14 | 浙江虹达特种橡胶制品有限公司杭州分公司 | Fire-and/or fire-fighting material |
| CN116814221A (en) * | 2022-11-29 | 2023-09-29 | 广州纳诺新材料技术有限公司 | Phase-change microcapsule, high-safety lithium battery and preparation method thereof |
| CN116814221B (en) * | 2022-11-29 | 2024-01-23 | 广州纳诺新材料技术有限公司 | Phase-change microcapsule, high-safety lithium battery and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113948767B (en) | 2024-01-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109148789B (en) | Diaphragm, preparation method thereof and lithium ion battery using diaphragm | |
| KR100687217B1 (en) | Battery System Containing Phase Change Material-containing Capsules In Interior Configuration Thereof | |
| CN104466186B (en) | Microcapsule and positive electrode material for battery as well as preparation methods and application of microcapsule and positive electrode material | |
| CN113948817B (en) | Preparation method of composite diaphragm for lithium battery and lithium battery using same | |
| US11677123B2 (en) | Mitigating thermal runaway in lithium ion batteries using damage-initiating materials or devices | |
| JP6091742B2 (en) | Electrochemical element with improved heat resistance | |
| CN113948767A (en) | Preparation method of safe lithium battery electrolyte containing microcapsule body and lithium battery | |
| WO2013080946A1 (en) | Separator for non-aqueous electrolyte cell and non-aqueous electrolyte cell using same | |
| CN205609666U (en) | Safe lithium ion power batteries positive plate | |
| CN106654125A (en) | Method for preparing modified ceramic diaphragm through dopamine compound adhesive and application thereof | |
| CN103165840B (en) | Electrode assembly of lithium secondary battery | |
| CN105742717B (en) | A method of promoting performance of lithium ion battery | |
| CN100583536C (en) | Polymer lithium ion battery preparation technique and products | |
| CN105140453A (en) | Ceramic composite membrane with thermal-shutdown function and application thereof | |
| Gao et al. | Bioinspired thermal runaway retardant capsules for improved safety and electrochemical performance in lithium‐ion batteries | |
| Wang et al. | Application of polymer-based phase change materials in thermal safety management of power batteries | |
| CN105529500A (en) | Manufacturing method for safe lithium ion power battery | |
| CN110994019A (en) | Flame-retardant microsphere electrolyte and preparation method thereof | |
| CN108091782A (en) | Accumulator and accumulator group | |
| CN115558471A (en) | Phase-change microcapsule, high-safety lithium battery composite positive electrode and preparation method thereof | |
| KR20240060535A (en) | Thermal runaway suppression element and the related applications | |
| CN101250276A (en) | Preparation method of modified diaphragm for polymer lithium-ion battery | |
| CN109671909B (en) | Negative electrode and nonaqueous electrolyte secondary battery provided with same | |
| CN115064837A (en) | Flame-retardant diaphragm and preparation method and application thereof | |
| CN108155307A (en) | Aluminum plastic film and application 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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |