CN113659204A - Electrolyte and application thereof - Google Patents
Electrolyte and application thereof Download PDFInfo
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- CN113659204A CN113659204A CN202110912096.9A CN202110912096A CN113659204A CN 113659204 A CN113659204 A CN 113659204A CN 202110912096 A CN202110912096 A CN 202110912096A CN 113659204 A CN113659204 A CN 113659204A
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- 239000003792 electrolyte Substances 0.000 title claims abstract description 75
- 229910001416 lithium ion Inorganic materials 0.000 claims abstract description 39
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 claims abstract description 38
- 239000000654 additive Substances 0.000 claims abstract description 35
- 229910003002 lithium salt Inorganic materials 0.000 claims abstract description 32
- -1 unsaturated silane compound Chemical class 0.000 claims abstract description 32
- 159000000002 lithium salts Chemical class 0.000 claims abstract description 31
- 230000000996 additive effect Effects 0.000 claims abstract description 28
- 239000003960 organic solvent Substances 0.000 claims abstract description 10
- 229910052744 lithium Inorganic materials 0.000 claims description 12
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 claims description 10
- FKRCODPIKNYEAC-UHFFFAOYSA-N ethyl propionate Chemical compound CCOC(=O)CC FKRCODPIKNYEAC-UHFFFAOYSA-N 0.000 claims description 6
- 229910019142 PO4 Inorganic materials 0.000 claims description 4
- IIPYXGDZVMZOAP-UHFFFAOYSA-N lithium nitrate Chemical compound [Li+].[O-][N+]([O-])=O IIPYXGDZVMZOAP-UHFFFAOYSA-N 0.000 claims description 4
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 claims description 4
- 239000010452 phosphate Substances 0.000 claims description 4
- VAYTZRYEBVHVLE-UHFFFAOYSA-N 1,3-dioxol-2-one Chemical compound O=C1OC=CO1 VAYTZRYEBVHVLE-UHFFFAOYSA-N 0.000 claims description 3
- SBLRHMKNNHXPHG-UHFFFAOYSA-N 4-fluoro-1,3-dioxolan-2-one Chemical compound FC1COC(=O)O1 SBLRHMKNNHXPHG-UHFFFAOYSA-N 0.000 claims description 3
- BTBUEUYNUDRHOZ-UHFFFAOYSA-N Borate Chemical compound [O-]B([O-])[O-] BTBUEUYNUDRHOZ-UHFFFAOYSA-N 0.000 claims description 3
- KMTRUDSVKNLOMY-UHFFFAOYSA-N Ethylene carbonate Chemical compound O=C1OCCO1 KMTRUDSVKNLOMY-UHFFFAOYSA-N 0.000 claims description 3
- RUOJZAUFBMNUDX-UHFFFAOYSA-N propylene carbonate Chemical compound CC1COC(=O)O1 RUOJZAUFBMNUDX-UHFFFAOYSA-N 0.000 claims description 3
- FSSPGSAQUIYDCN-UHFFFAOYSA-N 1,3-Propane sultone Chemical compound O=S1(=O)CCCO1 FSSPGSAQUIYDCN-UHFFFAOYSA-N 0.000 claims description 2
- UHOPWFKONJYLCF-UHFFFAOYSA-N 2-(2-sulfanylethyl)isoindole-1,3-dione Chemical compound C1=CC=C2C(=O)N(CCS)C(=O)C2=C1 UHOPWFKONJYLCF-UHFFFAOYSA-N 0.000 claims description 2
- OIFBSDVPJOWBCH-UHFFFAOYSA-N Diethyl carbonate Chemical compound CCOC(=O)OCC OIFBSDVPJOWBCH-UHFFFAOYSA-N 0.000 claims description 2
- 125000004423 acyloxy group Chemical group 0.000 claims description 2
- 125000003545 alkoxy group Chemical group 0.000 claims description 2
- IEJIGPNLZYLLBP-UHFFFAOYSA-N dimethyl carbonate Chemical compound COC(=O)OC IEJIGPNLZYLLBP-UHFFFAOYSA-N 0.000 claims description 2
- VEWLDLAARDMXSB-UHFFFAOYSA-N ethenyl sulfate;hydron Chemical compound OS(=O)(=O)OC=C VEWLDLAARDMXSB-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
- MHCFAGZWMAWTNR-UHFFFAOYSA-M lithium perchlorate Chemical compound [Li+].[O-]Cl(=O)(=O)=O MHCFAGZWMAWTNR-UHFFFAOYSA-M 0.000 claims description 2
- 229910001486 lithium perchlorate Inorganic materials 0.000 claims description 2
- 229910001496 lithium tetrafluoroborate Inorganic materials 0.000 claims description 2
- IGILRSKEFZLPKG-UHFFFAOYSA-M lithium;difluorophosphinate Chemical compound [Li+].[O-]P(F)(F)=O IGILRSKEFZLPKG-UHFFFAOYSA-M 0.000 claims description 2
- 125000000217 alkyl group Chemical group 0.000 claims 1
- PXHVJJICTQNCMI-UHFFFAOYSA-N nickel Substances [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 abstract description 19
- 229910052759 nickel Inorganic materials 0.000 abstract description 13
- 230000002035 prolonged effect Effects 0.000 abstract description 3
- 238000004519 manufacturing process Methods 0.000 description 13
- 230000000052 comparative effect Effects 0.000 description 11
- 238000000034 method Methods 0.000 description 11
- 239000002985 plastic film Substances 0.000 description 10
- 229920006255 plastic film Polymers 0.000 description 10
- 230000015572 biosynthetic process Effects 0.000 description 9
- 238000004806 packaging method and process Methods 0.000 description 8
- 238000002360 preparation method Methods 0.000 description 8
- 239000002994 raw material Substances 0.000 description 8
- 230000002829 reductive effect Effects 0.000 description 8
- 238000007599 discharging Methods 0.000 description 7
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 6
- 230000000694 effects Effects 0.000 description 6
- 239000010439 graphite Substances 0.000 description 6
- 229910002804 graphite Inorganic materials 0.000 description 6
- 238000006722 reduction reaction Methods 0.000 description 6
- 229910001428 transition metal ion Inorganic materials 0.000 description 6
- 239000010405 anode material Substances 0.000 description 4
- SMBQBQBNOXIFSF-UHFFFAOYSA-N dilithium Chemical class [Li][Li] SMBQBQBNOXIFSF-UHFFFAOYSA-N 0.000 description 4
- 206010016766 flatulence Diseases 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 238000007254 oxidation reaction Methods 0.000 description 4
- 238000003860 storage Methods 0.000 description 4
- 238000012360 testing method Methods 0.000 description 4
- 229910052782 aluminium Inorganic materials 0.000 description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical group [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 3
- 238000005520 cutting process Methods 0.000 description 3
- 238000004090 dissolution Methods 0.000 description 3
- 239000007772 electrode material Substances 0.000 description 3
- 239000008151 electrolyte solution Substances 0.000 description 3
- 150000002148 esters Chemical class 0.000 description 3
- 230000014759 maintenance of location Effects 0.000 description 3
- 239000011572 manganese Substances 0.000 description 3
- 230000003647 oxidation Effects 0.000 description 3
- 238000006864 oxidative decomposition reaction Methods 0.000 description 3
- BJWMSGRKJIOCNR-UHFFFAOYSA-N 4-ethenyl-1,3-dioxolan-2-one Chemical compound C=CC1COC(=O)O1 BJWMSGRKJIOCNR-UHFFFAOYSA-N 0.000 description 2
- 229910013872 LiPF Inorganic materials 0.000 description 2
- 229910001290 LiPF6 Inorganic materials 0.000 description 2
- 101150058243 Lipf gene Proteins 0.000 description 2
- HMDDXIMCDZRSNE-UHFFFAOYSA-N [C].[Si] Chemical compound [C].[Si] HMDDXIMCDZRSNE-UHFFFAOYSA-N 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 229910002091 carbon monoxide Inorganic materials 0.000 description 2
- 230000007797 corrosion Effects 0.000 description 2
- 238000005260 corrosion Methods 0.000 description 2
- 238000009616 inductively coupled plasma Methods 0.000 description 2
- 230000002401 inhibitory effect Effects 0.000 description 2
- 229910052748 manganese Inorganic materials 0.000 description 2
- 230000007246 mechanism Effects 0.000 description 2
- 239000007773 negative electrode material Substances 0.000 description 2
- 239000012785 packaging film Substances 0.000 description 2
- 229920006280 packaging film Polymers 0.000 description 2
- 238000002161 passivation Methods 0.000 description 2
- 239000007774 positive electrode material Substances 0.000 description 2
- 230000001681 protective effect Effects 0.000 description 2
- 238000007086 side reaction Methods 0.000 description 2
- 239000007784 solid electrolyte Substances 0.000 description 2
- 229910015013 LiAsF Inorganic materials 0.000 description 1
- 229910013075 LiBF Inorganic materials 0.000 description 1
- 229910013553 LiNO Inorganic materials 0.000 description 1
- 229910012258 LiPO Inorganic materials 0.000 description 1
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 1
- XBDQKXXYIPTUBI-UHFFFAOYSA-M Propionate Chemical compound CCC([O-])=O XBDQKXXYIPTUBI-UHFFFAOYSA-M 0.000 description 1
- KLARSDUHONHPRF-UHFFFAOYSA-N [Li].[Mn] Chemical compound [Li].[Mn] KLARSDUHONHPRF-UHFFFAOYSA-N 0.000 description 1
- 230000002159 abnormal effect Effects 0.000 description 1
- 230000001133 acceleration Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 150000004649 carbonic acid derivatives Chemical class 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 239000010406 cathode material Substances 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 229910017052 cobalt Inorganic materials 0.000 description 1
- 239000010941 cobalt Substances 0.000 description 1
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 230000001276 controlling effect Effects 0.000 description 1
- 150000002170 ethers Chemical class 0.000 description 1
- 238000004880 explosion Methods 0.000 description 1
- 239000011888 foil Substances 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 230000000670 limiting effect Effects 0.000 description 1
- 229910021645 metal ion Inorganic materials 0.000 description 1
- 239000011255 nonaqueous electrolyte Substances 0.000 description 1
- 239000005486 organic electrolyte Substances 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- QQONPFPTGQHPMA-UHFFFAOYSA-N propylene Natural products CC=C QQONPFPTGQHPMA-UHFFFAOYSA-N 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
- 150000004756 silanes Chemical class 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 125000000472 sulfonyl group Chemical group *S(*)(=O)=O 0.000 description 1
- 230000002195 synergetic effect Effects 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—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
- H01M10/0567—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
- H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
- H01M10/4235—Safety or regulating additives or arrangements in electrodes, separators or 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
-
- 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)
- Materials Engineering (AREA)
- Physics & Mathematics (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Inorganic Chemistry (AREA)
- Secondary Cells (AREA)
Abstract
The invention provides an electrolyte and application thereof, wherein the electrolyte comprises an organic lithium salt, an inorganic lithium salt, an additive and an organic solvent, the additive is an unsaturated silane compound, a double-lithium salt system is combined with the unsaturated silane compound additive, and the two aspects are combined together, so that the ballooning problem of a high-nickel ternary soft package lithium ion battery is effectively solved, the service life of the battery is prolonged, and the dynamic performance of the battery is ensured.
Description
Technical Field
The invention belongs to the technical field of lithium ion batteries, and relates to an electrolyte and application thereof.
Background
The lithium ion battery is composed of a negative electrode material and a positive electrode material which can remove and embed lithium ions, and a non-aqueous electrolyte, wherein the electrolyte mainly comprises lithium salt, an organic solvent and an additive. In the first charging process, the electrolyte is subjected to a reduction reaction on a negative electrode interface to form a passivation layer covering the surface of the negative electrode, namely a negative electrode Solid Electrolyte Interface (SEI) film. Meanwhile, on the anode interface, the electrolyte undergoes an oxidation reaction to form a passivation layer covering the surface of the anode, namely an anode electrolyte interface (CEI) film.
With the prolonging of the service life and the acceleration of high-temperature environment, the CEI film and the cathode material of the anode material of the lithium ion batteryThe structure of the SEI film is damaged, so that the electrode material is exposed, and therefore, an organic solvent in the electrolyte can generate an oxidation side reaction at the positive electrode and a reduction side reaction at the negative electrode, so that CO and CO are generated2、CH4And C2H6And the like, causing the problem of ballooning of the battery.
Compared with low-nickel and medium-nickel ternary materials, the high-nickel ternary material can obviously improve the energy density of the battery, but as the content of nickel is increased, Ni in the material is increased4+The catalytic activity is enhanced, and the oxidative decomposition gas production of the electrolyte is accelerated. In addition, the higher the nickel content is, the poorer the structural stability of the material after lithium removal is, so that more nickel, cobalt and manganese transition metal ions are dissolved out in the cycle process of the high-nickel system battery, and the transition metal ions can migrate to a negative electrode to damage a negative electrode SEI film, so that the electrolyte directly contacts the negative electrode material to generate gas through reduction. Therefore, the high nickel system also aggravates the problem of gas generation of the battery while improving the energy density of the battery, thereby shortening the service life of the battery and reducing the high-temperature service performance.
The soft package lithium ion battery has stricter requirements on the gas production rate of the battery, and the shell of the battery is an aluminum plastic film and is easy to deform. Along with the increase of gas production, the battery expands, and after the aluminum plastic film expands, the edge sealing is unsealed, so that the leakage of the battery is caused, and then the safety problems such as fire or explosion are caused.
At present, the problem of ballooning of the high-nickel ternary soft-package lithium ion battery is solved by adopting an electrolyte anode film-forming additive, so that the compactness and the thermal stability of a CEI (ceramic anode interface) film of an anode material are enhanced, the oxidation gas production of the electrolyte is reduced, and the reduction gas production of the electrolyte caused by the damage of transition metal ion dissolution to a cathode SEI film is inhibited. The current lithium ion battery electrolyte anode film-forming additive mostly adopts unsaturated ester additives such as Propylene Sultone (PST) and Vinyl Ethylene Carbonate (VEC), the additives contain unsaturated double bonds, can form a film by oxidation at the anode, and enhance the protection of the surface of an anode material, but the additives are preferentially reduced at the cathode to form a high-impedance macromolecular polymer SEI film, therefore, the battery impedance can be obviously increased when the usage is higher, the dynamic characteristic of the battery is reduced, the low-temperature and rate performance of the battery is degraded, if the addition is less, the additives are almost completely consumed and reacted at the cathode, no protection effect is exerted on the anode interface, and the problem of gas expansion of the battery cannot be solved.
CN102306834A discloses an electrolyte solution for improving flatulence of a soft package lithium manganese battery, which comprises three components: (1) lithium salt, (2) organic solvents of carbonates and/or ethers, (3) additives; the additive accounts for 0.01 to 20 percent of the mass percent of the electrolyte solution, and the molar concentration of the lithium salt in the electrolyte solution is 0.01 to 2 mol/L; the additive is a sulfinyl-and/or sulfonyl-containing compound. The electrolyte has too few additives, the flatulence is obvious, and the battery impedance is increased by too many additives.
CN106486629A discloses a soft package battery, which comprises a battery core and a packaging film coated outside the battery core, wherein the packaging film is formed with a battery cavity for accommodating the battery core and at least one air bag, and the battery cavity is communicated with the air bag through an air hole. When the inside of the battery core generates gas due to abnormal chemical reaction, the gas can enter the air bag through the air hole, so that the gas expansion condition of the soft package battery under the conditions of overcharge, overdischarge, high temperature and the like can be effectively improved, and the safety performance and the cycle life of the battery are improved. The soft package battery prepared by the method has poor safety and is easy to leak electrolyte.
According to the scheme, the resistance of the prepared electrolyte is high, the problems of poor flatulence solving effect or poor safety and the like are solved, and therefore, the development of the soft package battery which is good in flatulence solving effect, small in resistance and high in safety is necessary.
Disclosure of Invention
The invention aims to provide an electrolyte and application thereof, wherein the electrolyte adopts a double-lithium salt system combined with an unsaturated silane compound additive, and combines the two aspects, so that the ballooning problem of a high-nickel ternary soft package lithium ion battery is effectively solved, the service life of the battery is prolonged, and the dynamic performance of the battery is also ensured.
In order to achieve the purpose, the invention adopts the following technical scheme:
in a first aspect, the present invention provides an electrolyte comprising an organic lithium salt, an inorganic lithium salt, an additive and an organic solvent, the additive being an unsaturated silane compound.
The electrolyte comprises a dilithium salt and an unsaturated silane compound additive, wherein a dilithium salt system is formed by reacting two lithium salt anions with Li+The different coordination abilities and different redox film-forming mechanisms of the positive electrode and the negative electrode are synergistic, thereby forming a CEI film and an SEI film which are rich in inorganic lithium salt and have strong thermal stability on the inner layers of the positive electrode and the negative electrode, improving the high-temperature damage resistance of the interfacial film of the positive electrode and the negative electrode, reducing the gas production caused by the direct contact of an electrode material and an electrolyte, and improving the high-temperature service performance of the battery. The unsaturated silane compound additive can form a protective film on the interface of the anode material, reduce the oxidative decomposition gas production of the electrolyte, and can react with the protonic acid (HF), so that the reduction gas production of the electrolyte caused by the damage of the dissolved transition metal ions to the SEI film of the cathode is avoided; in addition, the additive does not participate in the formation of the negative electrode SEI film, so that the impedance of the negative electrode SEI film is not increased, and the dynamic performance of the battery is ensured.
Preferably, the unsaturated silane compound has a structural formula as shown in formulas I-VI:
VI, wherein R1, R2, R3 are each independently selected from C1-10Alkyl (-C) ofnH2n+1) Alkoxy (-OC)nH2n+1) Or acyloxy (-OCO-C)nH2n+1) Any one or a combination of at least two of them.
Preferably, the mass fraction of the unsaturated silane compound is 0.01 to 5%, preferably 0.1 to 2%, based on 100% by mass of the electrolyte.
Preferably, the organic lithium salt includes any one of or a combination of at least two of lithium bistrifluorosulfonylimide (LiFSI), lithium bistrifluoromethylsulfonylimide (LiTFSI), lithium difluorooxalato borate (LiODFB), lithium difluorobis-oxalato phosphate (lidfo), or lithium tetrafluorooxalato phosphate (litfo).
Preferably, the inorganic lithium salt includes lithium hexafluorophosphate (LiPF)6) Lithium tetrafluoroborate (LiBF)4) Lithium hexafluoroarsenate (LiAsF)6) Lithium perchlorate (LiClO)4) Lithium nitrate (LiNO)3) Or lithium difluorophosphate (LiPO)2F2) Any one or a combination of at least two of them.
Preferably, the total mass fraction of the organic lithium salt and the inorganic lithium salt is 10 to 25% based on 100% by mass of the electrolyte, for example: 10%, 12%, 15%, 18%, 20%, 25%, etc.
Preferably, the mass ratio of the organic lithium salt to the inorganic lithium salt is (1-20): 1-20), for example: 1:1, 1:5, 1:20, 5:1, 10:1 or 20:1, etc., preferably (1-15) to (1-15).
Preferably, the organic solvent includes any one of Ethylene Carbonate (EC), Propylene Carbonate (PC), dimethyl carbonate (DMC), diethyl carbonate (EMC), ethyl methyl carbonate (DEC), Ethyl Propionate (EP), or Propyl Propionate (PP), or a combination of at least two thereof.
Preferably, the mass fraction of the organic solvent is 50 to 90% based on 100% by mass of the electrolyte, for example: 50%, 60%, 70%, 80%, 90%, etc.
Preferably, the electrolyte further comprises a film forming additive.
Preferably, the film forming additive comprises any one of Vinylene Carbonate (VC), fluoroethylene carbonate (FEC), 1, 3-Propane Sultone (PS) or vinyl sulfate (DTD), or a combination of at least two thereof.
Preferably, the mass fraction of the film forming additive is 0.1-10% based on 100% of the electrolyte, such as: 0.1%, 0.5%, 1%, 3%, 5%, 8%, or 10%, etc.
In a second aspect, the present invention provides a lithium ion battery comprising the electrolyte according to the first aspect.
Compared with the prior art, the invention has the following beneficial effects:
(1) the electrolyte comprises the dilithium salt and the unsaturated silane compound additive, a dilithium salt system forms a CEI (continuous anodic electrolytic insulation) film and an SEI (solid electrolyte interface) film with strong thermal stability at a positive electrode interface and a negative electrode interface, the high-temperature damage resistance of the positive electrode interface film and the negative electrode interface film is improved, the gas generation caused by direct contact of an electrode material and the electrolyte is reduced, the high-temperature service performance of the battery is improved, the unsaturated silane compound additive can form a protective film at the positive electrode material interface, the oxidative decomposition gas generation of the electrolyte is reduced, and the unsaturated silane compound additive can react with protonic acid (HF), so that the reduction gas generation of the electrolyte caused by the damage of the negative electrode SEI film due to the dissolution of transition metal ions is avoided; in addition, the additive does not participate in the formation of the negative electrode SEI film, so that the impedance of the negative electrode SEI film is not increased, and the dynamic performance of the battery is ensured.
(2) The electrolyte disclosed by the invention effectively solves the problem of gas expansion of the high-nickel ternary soft package lithium ion battery, prolongs the service life of the battery, and simultaneously ensures the dynamic performance of the battery.
Detailed Description
The technical solution of the present invention is further explained by the following embodiments. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.
The electrolyte of the embodiment of the invention has the following components in percentage by mass as shown in table 1:
TABLE 1
The unsaturated silane compounds used in examples 1-8 have the following structural formula:
example 1
The embodiment provides a soft package lithium ion battery, and a preparation method of the soft package lithium ion battery comprises the following steps:
preparing electrolyte according to the raw material proportion shown in table 1, stacking an NCM811 positive plate, a diaphragm and a graphite negative plate in a Z-shaped manner in sequence, wherein the diaphragm is positioned between the positive plate and the negative plate, packaging a bare cell in an aluminum-plastic film, baking, injecting the electrolyte, and performing the procedures of pre-charging, degas, formation and the like to obtain the soft package lithium ion battery.
Example 2
The embodiment provides a soft package lithium ion battery, and a preparation method of the soft package lithium ion battery comprises the following steps:
preparing electrolyte according to the raw material proportion shown in table 1, stacking an NCM811 positive plate, a diaphragm and a graphite negative plate in a Z-shaped manner in sequence, wherein the diaphragm is positioned between the positive plate and the negative plate, packaging a bare cell in an aluminum-plastic film, baking, injecting the electrolyte, and performing the procedures of pre-charging, degas, formation and the like to obtain the soft package lithium ion battery.
Example 3
The embodiment provides a soft package lithium ion battery, and a preparation method of the soft package lithium ion battery comprises the following steps:
preparing electrolyte according to the raw material proportion shown in table 1, stacking an NCM811 positive plate, a diaphragm and a graphite negative plate in a Z-shaped manner in sequence, wherein the diaphragm is positioned between the positive plate and the negative plate, packaging a bare cell in an aluminum-plastic film, baking, injecting the electrolyte, and performing the procedures of pre-charging, degas, formation and the like to obtain the soft package lithium ion battery.
Example 4
The embodiment provides a soft package lithium ion battery, and a preparation method of the soft package lithium ion battery comprises the following steps:
preparing electrolyte according to the raw material proportion shown in table 1, stacking an NCM811 positive plate, a diaphragm and a silicon-carbon negative plate in a Z-shaped manner in sequence, wherein the diaphragm is positioned between the positive plate and the negative plate, packaging a bare cell in an aluminum-plastic film, baking, injecting the electrolyte, and performing the procedures of pre-charging, degas, formation and the like to obtain the soft package lithium ion battery.
Example 5
The embodiment provides a soft package lithium ion battery, and a preparation method of the soft package lithium ion battery comprises the following steps:
preparing electrolyte according to the raw material proportion shown in table 1, stacking an NCM9055 positive plate, a diaphragm and a graphite negative plate in a Z-shaped manner in sequence, wherein the diaphragm is positioned between the positive plate and the negative plate, packaging a bare cell in an aluminum-plastic film, baking, injecting the electrolyte, pre-charging, degas, forming and other processes to obtain the soft package lithium ion battery.
Example 6
The embodiment provides a soft package lithium ion battery, and a preparation method of the soft package lithium ion battery comprises the following steps:
preparing electrolyte according to the raw material proportion shown in table 1, stacking an NCM9055 positive plate, a diaphragm and a silicon-carbon negative plate in a Z-shaped mode in sequence, wherein the diaphragm is positioned between the positive plate and the negative plate, packaging a bare cell in an aluminum-plastic film, baking, injecting the electrolyte, and performing the procedures of pre-charging, degas, formation and the like to obtain the soft package lithium ion battery.
Example 7
The embodiment provides a soft package lithium ion battery, and a preparation method of the soft package lithium ion battery comprises the following steps:
preparing electrolyte according to the raw material proportion shown in table 1, stacking an NCM80155 positive plate, a diaphragm and a graphite negative plate in a Z-shaped manner in sequence, wherein the diaphragm is positioned between the positive plate and the negative plate, packaging a bare cell in an aluminum-plastic film, baking, injecting the electrolyte, and performing the procedures of pre-charging, degas, formation and the like to obtain the soft package lithium ion battery.
Example 8
The embodiment provides a soft package lithium ion battery, and a preparation method of the soft package lithium ion battery comprises the following steps:
preparing electrolyte according to the raw material proportion shown in table 1, stacking an NCM80155 positive plate, a diaphragm and a graphite negative plate in a Z-shaped manner in sequence, wherein the diaphragm is positioned between the positive plate and the negative plate, packaging a bare cell in an aluminum-plastic film, baking, injecting the electrolyte, and performing the procedures of pre-charging, degas, formation and the like to obtain the soft package lithium ion battery.
Example 9
This example is different from example 1 only in that the mass fraction of the unsaturated silane compound is 0.05%, and other conditions and parameters are exactly the same as those in example 1.
Example 10
This example is different from example 1 only in that the unsaturated silane compound is 5% by mass, and the other conditions and parameters are exactly the same as those in example 1.
Example 11
This example differs from example 1 only in LiFSI LiPF6The other conditions and parameters were exactly the same as in example 1 at 20: 1.
Example 12
This example differs from example 1 only in LiFSI LiPF6The other conditions and parameters were exactly the same as in example 1 at 1: 20.
Comparative example 1
This comparative example differs from example 1 only in that the unsaturated silane compound is not added, and the other conditions and parameters are exactly the same as those of example 1.
Comparative example 2
This comparative example differs from example 1 only in that 0.1% of the unsaturated silane compound is replaced by 0.5% of the unsaturated ester positive electrode additive PST, and the other conditions and parameters are exactly the same as those of example 1.
Comparative example 3
This comparative example differs from example 1 only in that only LiFSI was used as the lithium salt, and the other conditions and parameters were exactly the same as in example 1.
Comparative example 4
Book pairThe ratio differs from example 1 only in that only LiPF is used6The lithium salt was prepared under exactly the same conditions and parameters as in example 1.
And (3) performance testing:
the lithium ion batteries prepared in examples 1 to 12 and comparative examples 1 to 4 were subjected to the following tests, respectively:
charging to 4.2V at 25 ℃ under constant current and constant voltage of 1C, and cutting off the current of 0.05C; and then discharging to 2.75V at constant current of 1C to obtain the 1C discharge capacity of the battery cell. And charging the battery cell 1C to 4.2V at constant current and constant voltage, standing for 30min, discharging the battery to 50% SOC at 1C, standing for 1h, and discharging at 5C for 10 s. The DCR calculation formula is as follows: DCR ═ Vt-V0)/I*1000；Vt: voltage at pulse discharge time t; v0: voltage before pulse discharge; i: current, charge positive, discharge negative.
At 25 ℃, the battery is charged to 4.2V at a constant current of 2C, then discharged to 2.75V at a constant current of 1C, the charging capacity is recorded respectively, and the 2C multiplying factor charging retention rate is calculated by taking the 1C charging capacity as a reference (100%).
Charging to 4.2V at 25 ℃ under constant current and constant voltage of 1C, and cutting off the current of 0.05C; then discharging to 2.75V at constant current of 1C to obtain the discharge capacity before storage; then the voltage is charged to 4.2V by using a 1C constant current and a constant voltage, and the current is cut off to 0.05C. Then the battery is placed in an environment with the temperature of 60 ℃ for storage for 7 days and then taken out, after the battery is placed for 5 hours at normal temperature, the 1C constant current is discharged to 2.75V, and the storage capacity is obtained; then charging to 4.2V by using a 1C constant current and a constant voltage, and cutting off the current to 0.05C; and then discharging to 2.75V by using a 1C constant current to obtain the recovery capacity after storage. And finally, disassembling the stored battery, taking negative electrode powder, and testing the contents of metal ions Ni, Co and Mn by an inductively coupled plasma spectrometer (ICP).
Charging to 4.2V at 45 ℃ under a constant current and a constant voltage of 1C, stopping current of 0.05C, discharging to 2.75V under a constant current of 1C, circulating in such a way of charging and discharging, calculating a circulating capacity retention rate, calculating gas production, and testing results are shown in Table 2:
TABLE 2
As can be seen from Table 2, in examples 1 to 12, the DCR of the battery prepared by using the electrolyte of the present invention at 50% SOC was 6.92 mOhm or less, the 2C charge retention rate was 89.5% or more, the gas yield was 9.8mL or less after 1000 cycles, Ni was dissolved out at 70ppm or less, Co was dissolved out at 10ppm or less, and Mn was dissolved out at 9.8ppm or less.
Compared with the examples 9-10, the electrolyte with excellent performance can be prepared by controlling the mass fraction of the unsaturated silane compound in the electrolyte to be 0.1-2%, if the content of the unsaturated silane compound is too high, the DCR amplitude is reduced to a limited extent, the rate performance cannot be improved well, and if the content of the unsaturated silane compound is too low, the effect of inhibiting the high-temperature cycle gas production of the battery is general.
Compared with the examples 11 to 12, the mass ratio of the inorganic lithium salt to the organic lithium salt in the electrolyte affects the performance of the prepared electrolyte, the mass ratio of the organic lithium salt to the inorganic lithium salt is controlled to be (1-15) to (1-15), so that the electrolyte with good effect can be prepared, if the content of the inorganic electrolyte is too high, the corrosion to the positive electrode is aggravated and the gas production effect of the battery is not obvious, if the content of the organic electrolyte is too high, the corrosion to the aluminum foil is relatively serious, and the gas production inhibiting effect is general.
Compared with the comparative examples 1 and 2, the unsaturated silane compound adopted by the invention has impedance obviously lower than that of the traditional unsaturated ester additive, and does not obviously improve the DCR of the battery, so that the dynamic performance of the battery is ensured, and the unsaturated silane compound not only forms a high-thermal-stability CEI film on the positive electrode, but also reacts with HF, so that the dissolution of transition metal ions caused by the damage of the CEI film on the positive electrode is reduced, and the high-temperature cycle performance of the battery core is improved.
By comparing the embodiment 1 with the comparative examples 3-4, the invention adopts a double-salt system, forms the CEI and the SEI film with the inner layer rich in inorganic lithium salt and strong thermal stability on the positive electrode and the negative electrode through the film forming mechanism of the double-salt system and the cooperation of the two, and can effectively improve the thermal stability of the interface film of the positive electrode and the negative electrode and improve the high-temperature service performance of the battery by regulating and limiting the proportion of the two.
Compared with the examples 1-12 and the comparative examples 1-4, the gas production in the life cycle of the battery is obviously reduced after the double-salt system is combined with the unsaturated silane compound, the gas expansion problem of the ternary soft package lithium ion battery is effectively solved, the service life of the battery is prolonged, and the dynamic performance of the battery is ensured.
The applicant declares that the above description is only a specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and it should be understood by those skilled in the art that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are within the scope and disclosure of the present invention.
Claims (10)
1. An electrolyte is characterized by comprising an organic lithium salt, an inorganic lithium salt, an additive and an organic solvent, wherein the additive is an unsaturated silane compound.
2. The electrolyte of claim 1, wherein the unsaturated silane compound has a structural formula as shown in formulas I-VI:
VI, wherein R1, R2, R3 are each independently selected from C1-10Any one or a combination of at least two of the alkyl group, alkoxy group, or acyloxy group of (a).
Preferably, the mass fraction of the unsaturated silane compound is 0.01 to 5%, preferably 0.1 to 2%, based on 100% by mass of the electrolyte.
3. The electrolyte of claim 1 or 2, wherein the organic lithium salt comprises any one of or a combination of at least two of lithium bis (trifluorosulfonylimide), lithium bis (trifluoromethylsulfonylimide), lithium difluoro (oxalato) borate, lithium bis (oxalato) borate, lithium difluoro (oxalato) phosphate, or lithium tetrafluorooxalato phosphate.
4. The electrolyte of any one of claims 1 to 3, wherein the inorganic lithium salt comprises any one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium hexafluoroarsenate, lithium perchlorate, lithium nitrate or lithium difluorophosphate, or a combination of at least two thereof.
5. The electrolyte according to any one of claims 1 to 4, wherein the total mass fraction of the organic lithium salt and the inorganic lithium salt is 10 to 25% based on 100% by mass of the electrolyte;
the mass ratio of the organic lithium salt to the inorganic lithium salt is (1-20): 1-20, preferably (1-15): 1-15.
6. The electrolyte of any one of claims 1 to 5, wherein the organic solvent comprises any one of ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, ethyl propionate, or propyl propionate, or a combination of at least two thereof.
7. The electrolyte according to any one of claims 1 to 6, wherein the organic solvent is present in an amount of 50 to 90% by mass based on 100% by mass of the electrolyte.
8. The electrolyte of any one of claims 1-7, further comprising a film forming additive;
preferably, the film forming additive comprises any one of vinylene carbonate, fluoroethylene carbonate, 1, 3-propane sultone or vinyl sulfate or a combination of at least two of the same.
9. The electrolyte according to any one of claims 1 to 8, wherein the film-forming additive is present in an amount of 0.1 to 10% by mass based on 100% by mass of the electrolyte.
10. A lithium ion battery comprising the electrolyte of any one of claims 1 to 9.
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Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001185212A (en) * | 1999-12-22 | 2001-07-06 | Tonen Chem Corp | Nonaqueous electrolyte and battery containing the electrolyte |
| CN105811009A (en) * | 2016-05-09 | 2016-07-27 | 宁德时代新能源科技股份有限公司 | Electrolyte and lithium ion battery comprising same |
| CN105826599A (en) * | 2016-05-10 | 2016-08-03 | 北京理工大学 | Non-aqueous lithium ion battery electrolyte containing organic silicon additive |
| CN106374140A (en) * | 2016-11-11 | 2017-02-01 | 常熟市筑紫机械有限公司 | Preparation method of lithium battery electrolyte |
| JP2019106362A (en) * | 2017-12-12 | 2019-06-27 | セントラル硝子株式会社 | Electrolyte solution for nonaqueous electrolyte battery, and nonaqueous electrolyte battery using the same |
| WO2019146705A1 (en) * | 2018-01-24 | 2019-08-01 | セントラル硝子株式会社 | Electrolyte for non-aqueous electrolyte battery, and non-aqueous electrolyte battery using said electrolyte |
| CN110994022A (en) * | 2019-11-27 | 2020-04-10 | 惠州锂威新能源科技有限公司 | Electrolyte for silicon-carbon cathode and lithium ion battery |
| CN111433962A (en) * | 2017-12-06 | 2020-07-17 | 中央硝子株式会社 | Electrolyte for nonaqueous electrolyte battery and nonaqueous electrolyte battery using same |
| WO2021020515A1 (en) * | 2019-07-31 | 2021-02-04 | 三菱ケミカル株式会社 | Nonaqueous electrolyte solution and energy device |
| WO2021049648A1 (en) * | 2019-09-13 | 2021-03-18 | 旭化成株式会社 | Nonaqueous electrolyte solution and nonaqueous electrolyte secondary battery |
-
2021
- 2021-08-10 CN CN202110912096.9A patent/CN113659204A/en active Pending
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001185212A (en) * | 1999-12-22 | 2001-07-06 | Tonen Chem Corp | Nonaqueous electrolyte and battery containing the electrolyte |
| CN105811009A (en) * | 2016-05-09 | 2016-07-27 | 宁德时代新能源科技股份有限公司 | Electrolyte and lithium ion battery comprising same |
| CN105826599A (en) * | 2016-05-10 | 2016-08-03 | 北京理工大学 | Non-aqueous lithium ion battery electrolyte containing organic silicon additive |
| CN106374140A (en) * | 2016-11-11 | 2017-02-01 | 常熟市筑紫机械有限公司 | Preparation method of lithium battery electrolyte |
| CN111433962A (en) * | 2017-12-06 | 2020-07-17 | 中央硝子株式会社 | Electrolyte for nonaqueous electrolyte battery and nonaqueous electrolyte battery using same |
| JP2019106362A (en) * | 2017-12-12 | 2019-06-27 | セントラル硝子株式会社 | Electrolyte solution for nonaqueous electrolyte battery, and nonaqueous electrolyte battery using the same |
| WO2019146705A1 (en) * | 2018-01-24 | 2019-08-01 | セントラル硝子株式会社 | Electrolyte for non-aqueous electrolyte battery, and non-aqueous electrolyte battery using said electrolyte |
| JP2021057100A (en) * | 2018-01-24 | 2021-04-08 | セントラル硝子株式会社 | Electrolyte solution for nonaqueous electrolyte battery, and nonaqueous electrolyte battery arranged by use thereof |
| WO2021020515A1 (en) * | 2019-07-31 | 2021-02-04 | 三菱ケミカル株式会社 | Nonaqueous electrolyte solution and energy device |
| WO2021049648A1 (en) * | 2019-09-13 | 2021-03-18 | 旭化成株式会社 | Nonaqueous electrolyte solution and nonaqueous electrolyte secondary battery |
| CN110994022A (en) * | 2019-11-27 | 2020-04-10 | 惠州锂威新能源科技有限公司 | Electrolyte for silicon-carbon cathode and lithium ion battery |
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