WO2024078116A1 - Non-aqueous electrolyte and secondary battery - Google Patents

Non-aqueous electrolyte and secondary battery Download PDF

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Publication number
WO2024078116A1
WO2024078116A1 PCT/CN2023/113029 CN2023113029W WO2024078116A1 WO 2024078116 A1 WO2024078116 A1 WO 2024078116A1 CN 2023113029 W CN2023113029 W CN 2023113029W WO 2024078116 A1 WO2024078116 A1 WO 2024078116A1
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Prior art keywords
aqueous electrolyte
compound
lithium
structural formula
battery
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PCT/CN2023/113029
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French (fr)
Chinese (zh)
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曹朝伟
丁磊
周忠仓
胡时光
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深圳新宙邦科技股份有限公司
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Publication of WO2024078116A1 publication Critical patent/WO2024078116A1/en

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    • 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
    • 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
    • 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
    • H01M10/054—Accumulators with insertion or intercalation of metals other than lithium, e.g. with magnesium or aluminium
    • 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
    • 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
    • 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
    • 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

Definitions

  • the invention belongs to the technical field of energy storage battery devices, and in particular relates to a non-aqueous electrolyte and a secondary battery.
  • Secondary batteries have large capacity, fast charging speed and long cycle life, and have been widely used in various electronic devices in daily life.
  • a large number of studies have shown that the main reason for shortening the service life of secondary batteries is that the electrodes are prone to react with the electrolyte under high temperature and high pressure, causing electrode material loss and electrolyte deterioration.
  • the large amount of gas produced in many cases will also cause the battery volume to expand. All these changes can easily lead to poor battery performance and shortened service life.
  • the present application provides a non-aqueous electrolyte and a secondary battery.
  • the present application provides a non-aqueous electrolyte, including an electrolyte salt, a non-aqueous organic solvent and an additive, wherein the additive includes a compound shown in structural formula 1:
  • R 1 and R 2 are each independently selected from a hydrogen atom, a halogen atom, a C1-C5 hydrocarbon group or a C1-C5 halogenated hydrocarbon group.
  • the compound represented by the structural formula 1 is selected from at least one of the following compounds:
  • the mass percentage of the compound represented by the structural formula 1 is 0.05% to 10%.
  • the mass percentage of the compound represented by the structural formula 1 is 0.1% to 5%.
  • the concentration of the electrolyte salt in the non-aqueous electrolyte is 0.1 mol/L to 8 mol/L;
  • the electrolyte salt is selected from lithium salt or sodium salt.
  • the lithium salt is at least one selected from LiPF 6 , LiBOB, LiDFOB, LiPO 2 F 2 , LiBF 4 , LiSbF 6 , LiAsF 6 , LiN(SO 2 CF 3 ) 2 , LiN(SO 2 C 2 F 5 ) 2 , LiC(SO 2 CF 3 ) 3 , LiN(SO 2 F) 2 , LiClO 4 , LiAlCl 4 , LiCF 3 SO 3 , Li 2 B 10 Cl 10 , LiSO 3 F, LiTOP (lithium trioxalate phosphate), LiDODFP (lithium difluorodioxalate phosphate), LiOTFP (lithium tetrafluorooxalate phosphate) and lower aliphatic carboxylic acid lithium salts;
  • the sodium salt is at least one selected from the group consisting of NaPF6 , NaClO4 , NaAsF6 , NaSbF6 , NaPOF4 , NaPO2F2 , NaC4BO8 , NaC2BF2O4 , NaODFB, NaN ( SO2C2F5 ) 2 , NaN ( SO2CF3)( SO2C4F9 ) 2 , NaC( SO2CF3 ) and Na(C2F5 ) PF3 .
  • the non-aqueous electrolyte further comprises an auxiliary additive
  • the auxiliary additive comprises at least one of a cyclic sulfate compound, a sultone compound, a cyclic carbonate compound, a phosphate compound, a borate compound and a nitrile compound;
  • the amount of the auxiliary additive added is 0.01% to 30%.
  • the cyclic sulfate ester compound is selected from vinyl sulfate, propylene sulfate, or at least one of methyl vinyl sulfate;
  • the sultone compound is selected from 1,3-propane sultone, 1,4-butane sultone or 1,3-propylene sultone, At least one of;
  • the cyclic carbonate compound is selected from at least one of vinylene carbonate, ethylene carbonate, methylene carbonate, fluoroethylene carbonate, trifluoromethylethylene carbonate, bisfluoroethylene carbonate or the compound shown in structural formula 2;
  • R 21 , R 22 , R 23 , R 24 , R 25 , and R 26 are each independently selected from a hydrogen atom, a halogen atom, and a C1-C5 group;
  • the phosphate compound is selected from at least one of tris(trimethylsilyl)phosphate, tris(trimethylsilyl)phosphite or the compound shown in structural formula 3:
  • R 31 , R 32 and R 33 are each independently selected from a C1-C5 saturated hydrocarbon group, an unsaturated hydrocarbon group, a halogenated hydrocarbon group, A hydrocarbon group, -Si(C m H 2m+1 ) 3 , wherein m is a natural number of 1 to 3, and at least one of R 31 , R 32 and R 33 is an unsaturated hydrocarbon group;
  • the borate compound is selected from at least one of tris(trimethylsilyl)borate and tris(triethylsilyl)borate;
  • the nitrile compound includes at least one of succinonitrile, glutaronitrile, ethylene glycol bis(propionitrile) ether, hexanetrinitrile, adiponitrile, pimelonitrile, suberonitrile, azelaic acid dinitrile and sebaconitrile.
  • the non-aqueous organic solvent includes at least one of an ether solvent, a nitrile solvent, a carbonate solvent, a carboxylate solvent and a sulfone solvent.
  • the present application provides a secondary battery, comprising a positive electrode, a negative electrode and any one of the non-aqueous electrolytes described above.
  • the secondary battery is a lithium metal battery, a lithium ion battery or a sodium ion battery.
  • the non-aqueous electrolyte provided by the present application includes a compound shown in structural formula 1.
  • a reduction reaction can occur on the negative electrode to open the ring to generate multivalent anion radicals.
  • the multivalent anion radicals further react to generate multivalent salts with larger molecular weights.
  • the multivalent salts will form a regular network structure SEI film on the surface of the negative electrode.
  • the SEI film has greater flexibility. Even at high temperatures, the SEI film is not easy to break.
  • a stable SEI film helps to improve the high-temperature cycle performance and high-temperature storage performance of the battery and extend the cycle life of the battery.
  • the multivalent salts have a more Good oxidation resistance
  • the SEI film formed by the multivalent salt on the negative electrode surface also has better oxidation resistance, which can slow down the oxidation process of the electrolyte, and can significantly improve the high-temperature cycle performance and high-temperature storage performance of the lithium-ion battery;
  • the compound shown in structural formula 1 has a bicyclic structure with a total of two carbon atoms, the structure is more stable, one side of which is a five-membered ring cyclic sulfate ester, and the other side is a five-membered ring cyclic carbonate ester.
  • the sulfate group can form an interface film on the negative electrode surface, inhibit the co-embedding and reductive decomposition of solvent molecules in the negative electrode, and improve the high-temperature performance of the battery, and the carbonate group also participates in the film formation, which can effectively prevent the electrolyte from further decomposing. Therefore, a small amount of addition can change the cycle performance of the electrolyte, and it also has a good flame retardant effect, which can significantly improve the flash point of the electrolyte.
  • the present application provides a non-aqueous electrolyte solution, comprising an electrolyte salt, a non-aqueous organic solvent and an additive, wherein the additive comprises a compound represented by structural formula 1:
  • R 1 and R 2 are each independently selected from a hydrogen atom, a halogen atom, a C1-C5 hydrocarbon group or a C1-C5 halogenated hydrocarbon group.
  • the C1-C5 hydrocarbon group may be an alkyl group such as methyl, ethyl, propyl, butyl, pentyl, isopropyl, isobutyl, or an alkenyl group such as vinyl, propenyl, butenyl, or an alkynyl group such as ethynyl, propynyl, butynyl, etc.
  • the halogen atom may include at least one of F, Cl, Br, I, and At.
  • the non-aqueous organic solvent is unstable at high temperature and is easy to undergo reduction and decomposition on the negative electrode surface.
  • the accumulation at the negative electrode interface causes the battery impedance to continue to increase, and the SEI film is destroyed, which affects the battery's cycle performance and storage performance under high temperature conditions.
  • the inventor has found through a large number of studies that the compound shown in structural formula 1 is added to the non-aqueous electrolyte as an additive.
  • the compound shown in structural formula 1 can undergo a reduction reaction on the negative electrode to open the ring to generate multivalent anion radicals, and the multivalent anion radicals further react to generate multivalent salts with larger molecular weights.
  • the multivalent salts will form a regular network structure SEI film on the negative electrode surface.
  • the SEI film surface has greater flexibility, and the SEI film is not easy to break even at high temperatures.
  • the impedance increase is relatively slow, which can effectively reduce the decomposition of the electrolyte solvent on the negative electrode and reduce the generation of gas, thereby improving the electrochemical performance of lithium-ion batteries under high temperature conditions;
  • the multivalent salt also has better oxidation resistance, slows down the oxidation process of the electrolyte, and can significantly improve the high-temperature cycle performance and high-temperature storage performance of lithium-ion batteries.
  • the sulfate group can form a solid electrolyte phase interface film on the surface of the battery electrode, inhibit the co-embedding and reductive decomposition of solvent molecules in the negative electrode, improve the cycle performance and high temperature performance of the lithium-ion battery, and the cyclic carbonate group can also participate in the film formation, which can effectively prevent the electrolyte from further decomposing.
  • a small amount of addition can change the cycle performance of the electrolyte, and it also has a good flame retardant effect and can significantly improve the flash point of the electrolyte.
  • the compound shown in structural formula 1 is added to the non-aqueous electrolyte, an electrochemical reaction can occur on the electrode surface, and at the same time, it can be moderately cross-linked to form a relatively stable film structure, thereby improving the battery's electrical performance.
  • the co-carbon five-membered cyclic lipid compound shown in structural formula 1 helps the lithium-ion battery form a stable SEI film during the charging and discharging process, thereby effectively improving the battery's high-temperature performance and battery power characteristics, so that the prepared lithium-ion battery also has excellent electrochemical performance under high temperature conditions.
  • the compound represented by structural formula 1 is selected from at least one of the following compounds:
  • the mass percentage of the compound represented by Structural Formula 1 is 0.05% to 10%.
  • the mass percentage of the compound represented by the structural formula 1 is 0.1% to 5%.
  • the mass percentage of the compound shown in structural formula 1 in the non-aqueous electrolyte can be 0.05%, 0.08%, 0.1%, 0.5%, 0.8%, 1%, 1.2%, 1.5%, 1.8%, 2%, 2.2%, 2.5%, 2.8%, 3%, 3.2%, 3.5%, 3.8%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 7.8%, 8%, 8.5%, 9%, 9.5%, or 10%.
  • the mass percentage of the compound shown in Structural Formula 1 is within the range of 0.05% to 10%, an electrochemical reaction can occur on the electrode surface, forming a thin film structure with a stable structure on the electrode surface, which can effectively maintain the stability of the film formation on the electrode surface and improve the battery performance.
  • an electrochemical reaction can occur on the electrode surface, forming a thin film structure with a stable structure on the electrode surface, which can effectively maintain the stability of the film formation on the electrode surface and improve the battery performance.
  • a regular network structure and a flexible SEI film can be formed at the negative electrode interface.
  • the SEI film does not break under high temperature conditions, and the decomposition and oxidation reaction of the electrolyte solvent on the negative electrode can be reduced, reducing the generation of gas and improving the high temperature storage performance of the battery.
  • the compound shown in Structural Formula 1 is too little, the compound shown in Structural Formula 1 cannot form a regular network structure SEI film at the negative electrode interface during battery charging, and it is difficult to significantly improve the performance of the battery; if the amount of the compound shown in Structural Formula 1 added is too much, the content of other types of additives in the electrolyte is reduced, affecting the film formation reaction on the negative electrode surface, and at the same time, it may affect the function of other substances in the electrolyte due to its excessive decomposition products.
  • the concentration of the electrolyte salt in the non-aqueous electrolyte is 0.1 mol/L to 8 mol/L; in some preferred embodiments, the concentration of the electrolyte salt in the non-aqueous electrolyte is 0.5 mol/L to 2.5 mol/L.
  • the electrolyte salt is selected from a lithium salt or a sodium salt.
  • the lithium salt is selected from at least one of LiPF 6 , LiBOB, LiDFOB, LiPO 2 F 2 , LiBF 4 , LiSbF 6 , LiAsF 6 , LiN(SO 2 CF 3 ) 2 , LiN(SO 2 C 2 F 5 ) 2 , LiC(SO 2 CF 3 ) 3 , LiN(SO 2 F) 2 , LiClO 4 , LiAlCl 4 , LiCF 3 SO 3 , Li 2 B 10 Cl 10 , LiSO 3 F, LiTOP (lithium trioxalate phosphate), LiDODFP (lithium difluorodioxalate phosphate), LiOTFP (lithium tetrafluorooxalate phosphate) and lower aliphatic carboxylic acid lithium salts.
  • LiPF 6 LiBOB, LiDFOB, LiPO 2 F 2 , LiBF 4 , LiSbF 6 , LiAsF 6 , LiN(SO 2 CF 3 ) 2
  • the sodium salt is selected from at least one of NaPF 6 , NaClO 4 , NaAsF 6 , NaSbF 6 , NaPOF 4 , NaPO 2 F 2 , NaC 4 BO 8 , NaC 2 BF 2 O 4 , NaODFB, NaN(SO 2 C 2 F 5 ) 2 , NaN(SO 2 CF 3 )(SO 2 C 4 F 9 ) 2 , NaC(SO 2 CF 3 ) and Na(C 2 F 5 )PF 3 .
  • the concentration of the electrolyte salt can be 0.5mol/L, 1mol/L, 1.2mol/L, 1.5mol/L, 2mol/L, 2.5mol/L, 3mol/L, 3.5mol/L, 4mol/L, 4.5mol/L, 5mol/L, 6mol/L, 7mol/L, or 8mol/L.
  • the non-aqueous electrolyte further comprises an auxiliary additive, wherein the auxiliary additive comprises at least one of a cyclic sulfate compound, a sultone compound, a cyclic carbonate compound, an unsaturated phosphate compound, a borate compound, and a nitrile compound;
  • the amount of the auxiliary additive added is 0.01% to 30%.
  • the amount of any one of the optional substances in the auxiliary additives added to the non-aqueous electrolyte is less than 10%, preferably, the amount added is 0.1-5%, and more preferably, the amount added is 0.1% to 3%.
  • the amount of any one of the optional substances in the auxiliary additives can be 0.05%, 0.08%, 0.1%, 0.5%, 0.8%, 1%, 1.2%, 1.5%, 1.8%, 2%, 2.2%, 2.5%, 2.8%, 3%, 3.2%, 3.5%, 3.8%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 7.8%, 8%, 8.5%, 9%, 9.5%, 10%.
  • the cyclic sulfate ester compound is selected from vinyl sulfate (DTD), propylene sulfate, or at least one of methyl vinyl sulfate;
  • the sultone compound is selected from at least one of 1,3-propane sultone, 1,4-butane sultone or 1,3-propylene sultone (PS);
  • the cyclic carbonate compound is selected from at least one of propylene carbonate (PC), vinylene carbonate (VC), ethylene carbonate, methylene carbonate, trifluoromethyl carbonate, bisfluoroethylene carbonate or fluoroethylene carbonate or the compound shown in formula 2;
  • R 21 , R 22 , R 23 , R 24 , R 25 , and R 26 are each independently selected from a hydrogen atom, a halogen atom, and a C1-C5 group.
  • the compound represented by structural formula 2 comprises
  • the phosphate compound is selected from at least one of tris(trimethylsilyl)phosphate, tris(trimethylsilyl)phosphite or the compound shown in structural formula 3:
  • R 31 , R 32 and R 33 are independently selected from C1-C5 saturated hydrocarbon groups, unsaturated hydrocarbon groups, halogenated hydrocarbon groups, and -Si(C m H 2m+1 ) 3 , m is a natural number of 1 to 3, and at least one of R 31 , R 32 and R 33 is an unsaturated hydrocarbon group.
  • the compound shown in the structural formula 3 can be tripropargyl phosphate, dipropargyl methyl phosphate, dipropargyl ethyl phosphate, dipropargyl propyl phosphate, dipropargyl trifluoromethyl phosphate, dipropargyl-2,2,2-trifluoroethyl phosphate, dipropargyl-3,3,3-trifluoropropyl phosphate, dipropargyl hexafluoroisopropyl phosphate, triallyl phosphate, diallyl methyl phosphate, diallyl ethyl phosphate, diallyl propyl phosphate, diallyl trifluoromethyl phosphate, diallyl-2,2,2-trifluoroethyl phosphate, diallyl-3,3,3-trifluoropropyl phosphate, diallyl hexafluoroisopropyl phosphate. At least one of propyl phosphates.
  • the borate compound is selected from at least one of tris(trimethylsilyl)borate and tris(triethylsilyl)borate;
  • the nitrile compound includes at least one of succinonitrile, glutaronitrile, ethylene glycol bis(propionitrile) ether, hexanetrinitrile, adiponitrile, pimelonitrile, suberonitrile, azelaic acid dinitrile and sebaconitrile.
  • the auxiliary additives also include other additives that can improve battery performance: for example, additives that enhance battery safety performance, such as flame retardant additives such as fluorophosphates and cyclophosphazenes, or overcharge prevention additives such as tert-amylbenzene and tert-butylbenzene.
  • additives that enhance battery safety performance such as flame retardant additives such as fluorophosphates and cyclophosphazenes, or overcharge prevention additives such as tert-amylbenzene and tert-butylbenzene.
  • the solvent includes at least one of an ether solvent, a nitrile solvent, a carbonate solvent, a carboxylate solvent, and a sulfone solvent.
  • the ether solvent includes a cyclic ether or a chain ether, preferably a chain ether with 3 to 10 carbon atoms and a cyclic ether with 3 to 6 carbon atoms.
  • the cyclic ether may specifically include, but is not limited to, at least one of 1,3-dioxolane (DOL), 1,4-dioxolane (DX), crown ether, tetrahydrofuran (THF), 2-methyltetrahydrofuran (2-CH 3 -THF), and 2-trifluoromethyltetrahydrofuran (2-CF 3 -THF);
  • the chain ether may specifically include, but is not limited to, dimethoxymethane, diethoxymethane, ethoxymethoxymethane, ethylene glycol di-n-propyl ether, ethylene glycol di-n-butyl ether, and diethylene glycol dimethyl ether.
  • the chain ether has a high solvation ability with lithium ions and can improve ion dissociation, dimethoxymethane, diethoxymethane, and ethoxymethoxymethane, which have low viscosity and can impart high ionic conductivity, are particularly preferred.
  • the ether compound can be used alone or in any combination and ratio. There is no special restriction on the amount of ether compounds added, and it is arbitrary within the range that does not significantly damage the effect of the high-density lithium-ion battery of the present invention. In the case where the volume ratio of the non-aqueous solvent is 100%, the volume ratio is usually 1% or more, preferably 2% or more, and more preferably 3% or more.
  • the volume ratio is usually 30% or less, preferably 25% or less, and more preferably 20% or less.
  • the total amount of the ether compounds can be made to meet the above range.
  • the amount of ether compounds added is within the above preferred range, it is easy to ensure the improvement of ion conductivity brought about by the increase in lithium ion dissociation degree and the decrease in viscosity of the chain ether.
  • the negative electrode active material is a carbon material, the phenomenon of co-embedding of chain ethers and lithium ions can be suppressed, so that the input-output characteristics and charge-discharge rate characteristics can reach an appropriate range.
  • the nitrile solvent includes at least one of acetonitrile, glutaronitrile, and malononitrile.
  • the carbonate solvent includes a cyclic carbonate or a chain carbonate
  • the cyclic carbonate includes at least one of ethylene carbonate (EC), propylene carbonate (PC), ⁇ -butyrolactone (GBL), and butylene carbonate (BC)
  • the chain carbonate includes at least one of dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), diethyl carbonate (DEC), and dipropyl carbonate (DPC).
  • the content of the cyclic carbonate is arbitrary within the range that does not significantly damage the effect of the high-density lithium-ion battery of the present invention, but when one is used alone, the lower limit of its content is generally 3% or more by volume, preferably 5% or more by volume, relative to the total amount of solvent in the non-aqueous electrolyte.
  • the upper limit is usually 90% by volume or less, preferably 85% by volume or less, and more preferably 80% by volume or less.
  • the content of the chain carbonate is not particularly limited, and is usually 15% or more by volume, preferably 20% or more by volume, and more preferably 25% or more by volume relative to the total amount of solvent in the non-aqueous electrolyte.
  • the volume ratio is usually 90% or less, preferably 85% or less, and more preferably 80% or less by volume.
  • the content of the chain carbonate in the above range it is easy to make the viscosity of the non-aqueous electrolyte reach an appropriate range, suppress the reduction of ionic conductivity, and then help to make the output characteristics of the non-aqueous electrolyte battery reach a good range.
  • the total amount of the chain carbonates can be satisfied in the above range.
  • fluorinated chain carbonates chain carbonates with fluorine atoms
  • the number of fluorine atoms possessed by the fluorinated chain carbonate is not particularly limited as long as it is more than 1, but is generally less than 6, preferably less than 4.
  • these fluorine atoms can be bonded to the same carbon or to different carbons.
  • fluorinated chain carbonate fluorinated dimethyl carbonate derivatives, fluorinated ethyl methyl carbonate derivatives, fluorinated diethyl carbonate derivatives, etc. can be listed.
  • Carboxylic acid ester solvents include cyclic carboxylic acid esters and/or chain carbonates.
  • cyclic carboxylic acid esters include at least one of ⁇ -butyrolactone, ⁇ -valerolactone, and ⁇ -valerolactone.
  • chain carbonates include at least one of methyl acetate (MA), ethyl acetate (EA), propyl acetate (EP), butyl acetate, propyl propionate (PP), and butyl propionate.
  • the sulfone solvent includes a cyclic sulfone and a chain sulfone, but preferably, in the case of a cyclic sulfone, it is generally a compound having 3 to 6 carbon atoms, preferably 3 to 5 carbon atoms, and in the case of a chain sulfone, it is generally a compound having 2 to 6 carbon atoms, preferably 2 to 5 carbon atoms.
  • the amount of sulfone solvent added is arbitrary within the range that does not significantly damage the effect of the high-pressure lithium-ion battery of the present invention.
  • the volume ratio is generally 0.3% or more, preferably 0.5% or more, and more preferably 1% or more. In addition, the volume ratio is generally 40% or less, preferably 35% or less, and more preferably 30% or less. In the case of using two or more sulfone solvents in combination, the total amount of the sulfone solvents can be made to meet the above range. When the amount of sulfone solvent added is within the above range, an electrolyte with excellent high-temperature storage stability tends to be obtained.
  • the solvent is a mixture of cyclic carbonate and linear carbonate.
  • Another embodiment of the present invention provides a secondary battery including a positive electrode, a negative electrode, and the non-aqueous electrolyte as described above.
  • the secondary battery adopts the non-aqueous electrolyte as described above, it can form a passivation film with excellent performance on the positive electrode and the negative electrode, thereby effectively improving the high-temperature storage performance and high-temperature cycle performance of the battery and enhancing the battery power characteristics.
  • the secondary battery is a lithium metal battery, a lithium ion battery, a lithium sulfur battery, a sodium ion battery, etc.
  • the positive electrode includes a positive electrode material layer, and the positive electrode material layer includes a positive electrode active material.
  • the type of the positive electrode active material is not particularly limited, as long as it is a positive electrode active material or a conversion positive electrode material that can reversibly embed/de-embed metal ions (such as lithium ions or sodium ions).
  • the secondary battery is a lithium ion battery.
  • the type and content of the positive electrode active material of the lithium ion battery are not limited and can be selected according to actual needs.
  • the positive electrode active material can be selected from LiFe 1-x' M' x' PO 4 , At least one of LiMn2-y'My'O4 and LiNixCoyMnzM1 - xyzO2 , wherein M' is selected from at least one of Mn, Mg, Co, Ni, Cu, Zn, Al, Sn, B, Ga, Cr, Sr, V or Ti, M is selected from at least one of Fe, Co, Ni, Mn, Mg, Cu, Zn, Al, Sn, B, Ga, Cr, Sr, V or Ti, and 0 ⁇ x' ⁇ 1, 0 ⁇ y' ⁇ 1, 0 ⁇ y ⁇ 1, 0 ⁇ x ⁇ 1, 0 ⁇ z ⁇ 1, x+y+z ⁇ 1, and the positive electrode active material can also be selected from one or more of sulfides,
  • the secondary battery is a sodium ion battery
  • the type and content of the positive electrode active material of the sodium ion battery are not limited and can be selected according to actual needs.
  • the positive electrode active material can be selected from one or more of metallic sodium, carbon materials, alloy materials, overplated metal oxides, overplated metal sulfides, phosphorus-based materials, titanate materials, Prussian blue materials, sodium-containing layered oxides, sodium-containing sulfate compounds, and sodium-containing phosphate compounds.
  • the carbon material may be selected from one or more of graphite, soft carbon and hard carbon;
  • the alloy material may be selected from an alloy material composed of at least two of Si, Ge, Sn, Pb and Sb; the alloy material may also be selected from an alloy material composed of at least one of Si, Ge, Sn, Pb and Sb and C;
  • the chemical formula of the phosphate is Na 3 (MO 1-g PO 4 ) 2 F 1+2g , 0 ⁇ g ⁇ 1, M is selected from at least one of Al, V, Ge, Fe, and Ga, more preferably, the phosphate is Na 3 (VPO 4 ) 2 F 3 or Na 3 (VOPO 4 ) 2 F; and/or the chemical formula of the phosphate is Na 2 MPO 4 F, M is selected from at least one of Fe and Mn, more preferably, the phosphate is Na 2 FePO 4 F or Na 2 MnPO 4 F.
  • the chemical formula of the sulfate is Na 2 M(SO 4 ) 2 ⁇ 2H 2 O
  • M can be selected from at least one of Cr, Fe, Co, Ni, Cu, Mn, Sn, Mo, Sb, and V.
  • the titanate material may be selected from one or more of Na 2 Ti 3 O 7 , Na 2 Ti 6 O 13 , Na 4 Ti 5 O 12 , Li 4 Ti 5 O 12 , and NaTi 2 (PO 4 ) 3 .
  • the molecular formula of the Prussian blue material is Na x M[M′(CN) 6 ] y ⁇ zH 2 O, wherein M is a transition metal, M′ is a transition metal, 0 ⁇ x ⁇ 2, 0.8 ⁇ y ⁇ 1, and 0 ⁇ z ⁇ 20.
  • the Prussian blue material is Na x Mn[Fe(CN) 6 ] y ⁇ nH 2 O (0 ⁇ x ⁇ 2, 0 ⁇ y ⁇ 1, 0 ⁇ z ⁇ 10) or Na x Fe[Fe(CN) 6 ] y ⁇ nH 2 O (0 ⁇ x ⁇ 2, 0 ⁇ y ⁇ 1, 0 ⁇ z ⁇ 10).
  • the positive electrode further includes a positive electrode current collector, and the positive electrode material layer is disposed on a surface of the positive electrode current collector.
  • the positive electrode current collector is selected from metal materials that can conduct electrons.
  • the positive electrode current collector includes at least one of aluminum, nickel, tin, copper, and stainless steel.
  • the positive electrode material layer further includes a positive electrode binder and a positive electrode conductor, and the positive electrode active material, the positive electrode binder and the positive electrode conductor are blended to obtain the positive electrode material layer.
  • the positive electrode binder includes polyvinylidene fluoride, a copolymer of vinylidene fluoride, polytetrafluoroethylene, vinylidene fluoride-hexafluoropropylene
  • the invention relates to a copolymer of tetrafluoroethylene-hexafluoropropylene, a copolymer of tetrafluoroethylene-perfluoroalkyl vinyl ether, a copolymer of ethylene-tetrafluoroethylene, a copolymer of vinylidene fluoride-tetrafluoroethylene, a copolymer of vinylidene fluoride-trifluoroethylene, a copolymer of vinylidene fluoride-trichloroethylene, a copolymer of vinylidene fluoride-fluoroethylene, a copolymer of vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene,
  • the positive electrode conductive agent includes at least one of conductive carbon black, conductive carbon balls, conductive graphite, conductive carbon fibers, carbon nanotubes, graphene or reduced graphene oxide.
  • the negative electrode when the secondary battery is a lithium-ion battery, the negative electrode includes a negative electrode active material, and the negative electrode active material includes at least one of a carbon-based negative electrode, a silicon-based negative electrode, a tin-based negative electrode, a lithium negative electrode, a sodium negative electrode, a potassium negative electrode, a magnesium negative electrode, a zinc negative electrode, and an aluminum negative electrode.
  • the carbon-based negative electrode may include graphite, hard carbon, soft carbon, graphene, mesophase carbon microspheres, etc.; the silicon-based negative electrode may include silicon materials, silicon oxides, silicon-carbon composite materials, and silicon alloy materials; the tin-based negative electrode may include tin, tin carbon, tin oxygen, and tin metal compounds; the lithium-based negative electrode may include metallic lithium or a lithium alloy.
  • the lithium alloy may specifically be at least one of a lithium-silicon alloy, a lithium-sodium alloy, a lithium-potassium alloy, a lithium-aluminum alloy, a lithium-tin alloy, and a lithium-indium alloy.
  • its negative electrode active material includes at least one of metallic sodium, graphite, soft carbon, hard carbon, carbon fiber, mesophase carbon microspheres, silicon-based materials, tin-based materials, lithium titanate or other metals that can form alloy materials with sodium.
  • the alloy material can also be selected from an alloy material composed of at least one of Si, Ge, Sn, Pb, Sb and C
  • the graphite can be selected from at least one of artificial graphite, natural graphite and modified graphite
  • the silicon-based material can be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, and silicon alloys
  • the tin-based material can be selected from at least one of elemental tin, tin oxide compounds, and tin alloys.
  • the negative electrode further comprises a negative electrode current collector, and the negative electrode material layer is disposed on the surface of the negative electrode current collector.
  • the negative electrode current collector is selected from a metal material that can conduct electrons, preferably, the negative electrode current collector comprises at least one of Al, Ni, tin, copper, and stainless steel, and in a more preferred embodiment, the negative electrode current collector is selected from copper foil.
  • the negative electrode material layer further includes a negative electrode binder and a negative electrode conductive agent, and the negative electrode active material, the negative electrode binder and the negative electrode conductive agent are mixed to obtain the negative electrode material layer.
  • the negative electrode binder and the negative electrode conductive agent may be the same as the positive electrode binder and the positive electrode conductive agent, respectively, and will not be described in detail here.
  • the secondary battery further includes a separator, and the separator is located between the positive electrode and the negative electrode.
  • the diaphragm may be an existing conventional diaphragm, which may be a polymer diaphragm, a non-woven fabric, etc., including but not limited to single-layer PP (polypropylene), single-layer PE (polyethylene), double-layer PP/PE, double-layer PP/PP and triple-layer PP/PE/PP diaphragms.
  • PP polypropylene
  • PE polyethylene
  • double-layer PP/PE double-layer PP/PE
  • PP/PP double-layer PP/PP
  • triple-layer PP/PE/PP diaphragms triple-layer PP/PE/PP diaphragms.
  • This embodiment takes the preparation of a lithium ion battery as an example to illustrate the present invention, and includes the following steps:
  • LiPF 6 lithium hexafluorophosphate
  • the positive electrode active material lithium nickel cobalt manganese oxide LiNi 0.5 Co 0.2 Mn 0.3 O 2 , conductive carbon black Super-P and binder polyvinylidene fluoride (PVDF) are mixed in a mass ratio of 93:4:3, and then dispersed in N-methyl-2-pyrrolidone (NMP) to obtain a positive electrode slurry.
  • NMP N-methyl-2-pyrrolidone
  • the slurry is evenly coated on both sides of the aluminum foil, dried, rolled and vacuum dried, and welded with an aluminum lead wire using an ultrasonic welder to obtain a positive electrode plate, the thickness of which is between 120-150 ⁇ m.
  • the negative electrode active material artificial graphite, conductive carbon black Super-P, binder styrene-butadiene rubber (SBR) and carboxymethyl cellulose (CMC) are mixed in a mass ratio of 94:1:2.5:2.5, and then dispersed in deionized water to obtain negative electrode slurry.
  • the slurry is coated on both sides of the copper foil, dried, rolled and vacuum dried, and the nickel lead wire is welded with an ultrasonic welder to obtain the negative electrode sheet, and the thickness of the electrode sheet is between 120-150 ⁇ m.
  • a three-layer separator with a thickness of 20 ⁇ m was placed between the positive electrode sheet and the negative electrode sheet, and then the sandwich structure consisting of the positive electrode sheet, the negative electrode sheet and the separator was wound, and then the wound body was flattened and placed in an aluminum foil packaging bag, and vacuum-baked at 75°C for 48 hours to obtain to the battery cell to be filled.
  • the prepared electrolyte was injected into the battery cell, vacuum packaged, and left to stand for 24 hours.
  • Examples 2 to 18 are used to illustrate the lithium ion battery and the preparation method thereof disclosed in the present invention, and include most of the operation steps in Example 1, except that:
  • Comparative Examples 1 to 7 are used to compare and illustrate the lithium ion battery and the preparation method thereof disclosed in the present invention, and include most of the operation steps in Example 1, except that:
  • the formed lithium-ion battery is charged to 4.2V at a constant current of 1C at room temperature, then charged to a cut-off current of 0.05C at a constant current and voltage, and then discharged to 3.0V at a constant current of 1C, and the initial discharge capacity D1, initial battery volume V1 and initial impedance F1 of the battery are measured. After being fully charged and stored in an environment of 60°C for 30 days, it is discharged to 3V at 1C, and the battery retention capacity D2, recovery capacity D3, impedance F2 after storage and battery volume V2 after storage are measured.
  • the calculation formula is as follows:
  • Battery capacity retention rate (%) retention capacity D2/initial capacity D1 ⁇ 100%
  • Battery capacity recovery rate (%) recovery capacity D3/initial capacity D1 ⁇ 100%
  • Volume expansion rate (%) (battery volume after storage V2-initial battery volume V1)/initial battery volume V1 ⁇ 100%;
  • Internal resistance growth rate (%) (post-storage impedance F2 - initial impedance F1) / initial impedance F1 ⁇ 100%.
  • the lithium-ion battery was placed in an oven at a constant temperature of 45°C, charged to 4.2V at a constant current of 1C, then charged at a constant voltage until the current dropped to 0.02C, and then discharged to 3.0V at a constant current of 1C. This cycle was repeated, and the discharge capacity of the first week and the discharge capacity of the last week were recorded.
  • the capacity retention rate of the cycle is calculated as follows:
  • Battery capacity retention rate (%) discharge capacity in the last week/discharge capacity in the first week ⁇ 100%.
  • Example 4 By comparing Example 4 with Comparative Examples 2-5, it is known that compared with traditional vinylene carbonate (VC), vinyl sulfate (DTD), 1,3-propane sultone (PS) and tris(trimethylsilyl) phosphate (TMSP), the compound shown in the structural formula 1 provided in the present application is used as an additive, which can more significantly improve the storage performance of lithium-ion batteries at high temperatures, indicating that the passivation film formed by the co-carbon five-membered cyclic ester compound shown in the structural formula 1 has better high-temperature stability and is more stable under high temperature conditions.
  • Comparison between Example 4 and Example 10 shows that the auxiliary additive and the compound shown in Structural Formula 1 have the effect of synergistically improving the high temperature storage and cycle performance of the battery.
  • Example 19 The present invention is described by taking the preparation of a sodium ion battery as an example, comprising the following steps:
  • the positive electrode active material Na 3 V 2 (PO 4 ) 3 , the conductive carbon black Super-P and the binder polyvinylidene fluoride (PVDF) were mixed in a mass ratio of 94:3:3, and then dispersed in N-methyl-2-pyrrolidone (NMP) to obtain a positive electrode slurry.
  • NMP N-methyl-2-pyrrolidone
  • the slurry was evenly coated on both sides of the aluminum foil, dried, rolled and vacuum dried, and welded with aluminum or nickel lead wires using an ultrasonic welder. After the wire is cut, the positive electrode sheet is obtained, and its thickness is between 80-200 ⁇ m.
  • the negative electrode active material spherical hard carbon, conductive carbon black Super-P, binder styrene butadiene rubber (SBR) and carboxymethyl cellulose (CMC) are mixed in a mass ratio of 97:1:1:1, and then dispersed in deionized water to obtain a negative electrode slurry.
  • the slurry is coated on both sides of the aluminum foil, dried, rolled and vacuum dried, and welded with aluminum or nickel lead wires using an ultrasonic welder to obtain a negative electrode sheet with a thickness between 80-300 ⁇ m.
  • the positive electrode sheet, the separator, and the negative electrode sheet are stacked in order, and the preparation of the sodium ion battery is completed by aluminum-plastic film packaging, re-baking, liquid injection, static placement, formation, fixture shaping, secondary sealing, and capacity testing.
  • Examples 19 to 36 are used to illustrate the sodium ion battery and the preparation method thereof disclosed in the present invention, and include most of the operation steps in Example 18, except that:
  • Comparative Examples 8 to 14 are used to compare and illustrate the sodium ion battery and the preparation method thereof disclosed in the present invention, and include most of the operating steps in Example 19, except that:
  • the sodium ion battery prepared above was subjected to the following performance tests:
  • the formed sodium ion battery was charged to 4.0V at a constant current of 0.5C at room temperature, then charged at a constant voltage until the current dropped to 0.03C, and then discharged to 1.5V at a constant current of 1C, and the initial discharge capacity C1, initial battery volume V'1 and initial impedance F'1 of the battery were measured. After being fully charged and stored in an environment of 60°C for 30 days, it was discharged to 3V at 1C, and the battery retention capacity C2, recovery capacity C3, impedance F'2 after storage and battery volume V'2 after storage were measured.
  • the calculation formula is as follows:
  • Battery capacity retention rate (%) retention capacity C2/initial capacity C1 ⁇ 100%
  • Battery capacity recovery rate (%) recovery capacity C3/initial capacity C1 ⁇ 100%
  • Volume expansion rate (%) (battery volume after storage V'2 - initial battery volume V'1 ) / initial battery volume V'1 ⁇ 100%;
  • Internal resistance growth rate (%) (impedance after storage F' 2 - initial impedance F' 1 )/initial impedance F' 1 ⁇ 100%.
  • the formed battery was placed at 45°C for 2h, charged at a constant current of 0.5C to 4.0V, then charged at a constant voltage to a current of 0.03C, and then discharged at a constant current of 1C to 1.5V, for 200 cycles.
  • Battery capacity retention rate (%) discharge capacity C5/initial capacity C4 ⁇ 100%.
  • Example 22 and Comparative Examples 9 to 12 it can be seen from the test results of Example 22 and Comparative Examples 9 to 12 that, compared with conventional film-forming additives and combinations thereof, such as vinylene carbonate (VC), dithiothreitol (DTD), 1,3-propane sultone (PS) or fluoroethylene carbonate (FEC), the compound represented by the structural formula 1 provided in the present application is used as an additive, which can more significantly improve the performance of sodium ion batteries at high temperatures. The storage performance and cycle performance at room temperature are improved, and the battery expansion rate and internal resistance growth rate are reduced, indicating that compared with conventional film-forming additives, the passivation film formed by the compound shown in Structural Formula 1 has better high-temperature stability.
  • conventional film-forming additives and combinations thereof such as vinylene carbonate (VC), dithiothreitol (DTD), 1,3-propane sultone (PS) or fluoroethylene carbonate (FEC)

Abstract

Provided are a non-aqueous electrolyte and a battery, for use in overcoming the problem in the prior art of poor high-temperature storage performance of a secondary battery. The non-aqueous electrolyte comprises an electrolyte salt, a non-aqueous organic solvent and an additive. The additive comprises a compound as represented by a structural formula 1, wherein R1 and R2 are each independently selected from a hydrogen atom, a halogen atom, a C1-C5 hydrocarbyl group or a C1-C5 halogenated hydrocarbyl group. The non-aqueous electrolyte can form a stable SEI film on the surface of a negative electrode, thereby reducing the decomposition of the solvent on the negative electrode, and improving the high-temperature storage performance and the high-temperature cycle performance of the battery.

Description

一种非水电解液及二次电池Non-aqueous electrolyte and secondary battery 技术领域Technical Field
本发明属于储能电池器件技术领域，具体涉及一种非水电解液及二次电池。The invention belongs to the technical field of energy storage battery devices, and in particular relates to a non-aqueous electrolyte and a secondary battery.
背景技术Background technique
二次电池容量大、充电速度快、循环寿命长，已广泛应用于日常生活的各类电子设备上。大量研究显示，缩短二次电池使用寿命的主要原因是电极在高温高压环境下容易与电解液发生反应，造成电极材料损耗、电解液变质，而且很多时候产生的大量气体还会造成电池体积膨胀，种种变化都容易导致电池性能变劣、使用寿命缩短。Secondary batteries have large capacity, fast charging speed and long cycle life, and have been widely used in various electronic devices in daily life. A large number of studies have shown that the main reason for shortening the service life of secondary batteries is that the electrodes are prone to react with the electrolyte under high temperature and high pressure, causing electrode material loss and electrolyte deterioration. In addition, the large amount of gas produced in many cases will also cause the battery volume to expand. All these changes can easily lead to poor battery performance and shortened service life.
现有技术中为了提高二次电池的各项性能，许多科研者通过往电解液中添加不同的负极成膜添加剂，例如碳酸亚乙烯酯，氟代碳酸乙烯酯，碳酸乙烯亚乙酯，1,3-丙烷磺酸内酯等添加剂来改善CEI膜或SEI膜的质量，从而改善电池的各项性能。但是在电解液中添加上述物质后，并不能有效抑制溶剂在正极表面或负极表面的分解，破坏已经形成的CEI膜或SEI膜，锂离子电池的高温存储和循环性能仍然较差。因此研发一种能保证二次电池在高温下的电化学性能优异的非水电解液至关重要。In order to improve the performance of secondary batteries in the prior art, many researchers have added different negative electrode film-forming additives to the electrolyte, such as vinylene carbonate, fluoroethylene carbonate, vinyl ethylene carbonate, 1,3-propane sultone and other additives to improve the quality of the CEI film or SEI film, thereby improving the performance of the battery. However, after adding the above substances to the electrolyte, it is not possible to effectively inhibit the decomposition of the solvent on the positive electrode surface or the negative electrode surface, destroy the already formed CEI film or SEI film, and the high-temperature storage and cycle performance of the lithium-ion battery is still poor. Therefore, it is very important to develop a non-aqueous electrolyte that can ensure the excellent electrochemical performance of secondary batteries at high temperatures.
发明内容Summary of the invention
针对现有技术中二次电池高温性能差的问题，本申请提供一种非水电解液及二次电池。In view of the problem of poor high temperature performance of secondary batteries in the prior art, the present application provides a non-aqueous electrolyte and a secondary battery.
为解决上述技术问题，本申请提供一种非水电解液，包括电解质盐、非水有机溶剂和添加剂，所述添加剂包括结构式1所示的化合物：
In order to solve the above technical problems, the present application provides a non-aqueous electrolyte, including an electrolyte salt, a non-aqueous organic solvent and an additive, wherein the additive includes a compound shown in structural formula 1:
其中，R1、R2各自独立地选自氢原子、卤素原子、C1-C5的烃基或C1-C5的卤代烃基。Wherein, R 1 and R 2 are each independently selected from a hydrogen atom, a halogen atom, a C1-C5 hydrocarbon group or a C1-C5 halogenated hydrocarbon group.
优选的，所述结构式1所示的化合物选自以下化合物中的至少一种：
Preferably, the compound represented by the structural formula 1 is selected from at least one of the following compounds:
优选的，以所述非水电解液的总质量为100％计，所述结构式1所示的化合物的质量百分含量为0.05％～10％。Preferably, based on the total mass of the non-aqueous electrolyte being 100%, the mass percentage of the compound represented by the structural formula 1 is 0.05% to 10%.
优选的，以所述非水电解液的总质量为100％计，所述结构式1所示的化合物的质量百分含量为0.1％～5％。Preferably, based on the total mass of the non-aqueous electrolyte being 100%, the mass percentage of the compound represented by the structural formula 1 is 0.1% to 5%.
优选的，所述非水电解液中电解质盐的浓度为0.1mol/L～8mol/L；Preferably, the concentration of the electrolyte salt in the non-aqueous electrolyte is 0.1 mol/L to 8 mol/L;
所述电解质盐选自锂盐或钠盐。The electrolyte salt is selected from lithium salt or sodium salt.
优选的，所述锂盐选自LiPF6、LiBOB、LiDFOB、LiPO2F2、LiBF4、LiSbF6、LiAsF6、LiN(SO2CF3)2、LiN(SO2C2F5)2、LiC(SO2CF3)3、LiN(SO2F)2、LiClO4、LiAlCl4、LiCF3SO3、Li2B10Cl10、LiSO3F、LiTOP(三草酸磷酸锂)、LiDODFP(二氟二草酸磷酸锂)、LiOTFP(四氟草酸磷酸锂)和低级脂肪族羧酸锂盐中的至少一种；Preferably, the lithium salt is at least one selected from LiPF 6 , LiBOB, LiDFOB, LiPO 2 F 2 , LiBF 4 , LiSbF 6 , LiAsF 6 , LiN(SO 2 CF 3 ) 2 , LiN(SO 2 C 2 F 5 ) 2 , LiC(SO 2 CF 3 ) 3 , LiN(SO 2 F) 2 , LiClO 4 , LiAlCl 4 , LiCF 3 SO 3 , Li 2 B 10 Cl 10 , LiSO 3 F, LiTOP (lithium trioxalate phosphate), LiDODFP (lithium difluorodioxalate phosphate), LiOTFP (lithium tetrafluorooxalate phosphate) and lower aliphatic carboxylic acid lithium salts;
所述钠盐选自NaPF6、NaClO4、NaAsF6、NaSbF6、NaPOF4、NaPO2F2、NaC4BO8、NaC2BF2O4、NaODFB、NaN(SO2C2F5)2、NaN(SO2CF3)(SO2C4F9)2、NaC(SO2CF3)和Na(C2F5)PF3中的至少一种。The sodium salt is at least one selected from the group consisting of NaPF6 , NaClO4 , NaAsF6 , NaSbF6 , NaPOF4 , NaPO2F2 , NaC4BO8 , NaC2BF2O4 , NaODFB, NaN ( SO2C2F5 ) 2 , NaN ( SO2CF3)( SO2C4F9 ) 2 , NaC( SO2CF3 ) and Na(C2F5 ) PF3 .
优选的，所述非水电解液还包括辅助添加剂，所述辅助添加剂包括环状硫酸酯类化合物、磺酸内酯类化合物、环状碳酸酯类化合物、磷酸酯类化合物、硼酸酯类化合物和腈类化合物中的至少一种；Preferably, the non-aqueous electrolyte further comprises an auxiliary additive, and the auxiliary additive comprises at least one of a cyclic sulfate compound, a sultone compound, a cyclic carbonate compound, a phosphate compound, a borate compound and a nitrile compound;
以所述非水电解液的总质量为100％计，所述辅助添加剂的添加量为0.01％～30％。 Based on the total mass of the non-aqueous electrolyte being 100%, the amount of the auxiliary additive added is 0.01% to 30%.
优选的，所述环状硫酸酯类化合物选自硫酸乙烯酯、硫酸丙烯酯、 或甲基硫酸乙烯酯中的至少一种；Preferably, the cyclic sulfate ester compound is selected from vinyl sulfate, propylene sulfate, or at least one of methyl vinyl sulfate;
所述磺酸内酯类化合物选自1,3-丙烷磺酸内酯、1,4-丁烷磺酸内酯或1,3-丙烯磺酸内酯、中的至少一种；The sultone compound is selected from 1,3-propane sultone, 1,4-butane sultone or 1,3-propylene sultone, At least one of;
所述环状碳酸酯类化合物选自碳酸亚乙烯酯、碳酸乙烯亚乙酯、亚甲基碳酸乙烯酯、氟代碳酸乙烯酯、三氟甲基碳酸乙烯酯、双氟代碳酸乙烯酯或结构式2所示化合物中的至少一种；
The cyclic carbonate compound is selected from at least one of vinylene carbonate, ethylene carbonate, methylene carbonate, fluoroethylene carbonate, trifluoromethylethylene carbonate, bisfluoroethylene carbonate or the compound shown in structural formula 2;
所述结构式2中，R21、R22、R23、R24、R25、R26各自独立地选自氢原子、卤素原子、C1-C5基团中的一种；In the structural formula 2, R 21 , R 22 , R 23 , R 24 , R 25 , and R 26 are each independently selected from a hydrogen atom, a halogen atom, and a C1-C5 group;
所述磷酸酯类化合物选自三(三甲基硅烷)磷酸酯、三(三甲基硅烷)亚磷酸酯或结构式3所示化合物中的至少一种：
The phosphate compound is selected from at least one of tris(trimethylsilyl)phosphate, tris(trimethylsilyl)phosphite or the compound shown in structural formula 3:
所述结构式3中，R31、R32、R33各自独立的选自C1-C5的饱和烃基、不饱和烃基、卤代 烃基、-Si(CmH2m+1)3，m为1～3的自然数，且R31、R32、R33中至少有一个为不饱和烃基；In the structural formula 3, R 31 , R 32 and R 33 are each independently selected from a C1-C5 saturated hydrocarbon group, an unsaturated hydrocarbon group, a halogenated hydrocarbon group, A hydrocarbon group, -Si(C m H 2m+1 ) 3 , wherein m is a natural number of 1 to 3, and at least one of R 31 , R 32 and R 33 is an unsaturated hydrocarbon group;
所述硼酸酯类化合物选自三(三甲基硅烷)硼酸酯和三(三乙基硅烷)硼酸酯中的至少一种；The borate compound is selected from at least one of tris(trimethylsilyl)borate and tris(triethylsilyl)borate;
所述腈类化合物包括丁二腈、戊二腈、乙二醇双(丙腈)醚、己烷三腈、己二腈、庚二腈、辛二腈、壬二腈、癸二腈中的至少一种。The nitrile compound includes at least one of succinonitrile, glutaronitrile, ethylene glycol bis(propionitrile) ether, hexanetrinitrile, adiponitrile, pimelonitrile, suberonitrile, azelaic acid dinitrile and sebaconitrile.
优选的，所述非水有机溶剂包括醚类溶剂、腈类溶剂、碳酸酯类溶剂、羧酸酯类溶剂和砜类溶剂中的至少一种。Preferably, the non-aqueous organic solvent includes at least one of an ether solvent, a nitrile solvent, a carbonate solvent, a carboxylate solvent and a sulfone solvent.
另一方面，本申请提供一种二次电池，包括正极、负极及上述任意一项所述的非水电解液。On the other hand, the present application provides a secondary battery, comprising a positive electrode, a negative electrode and any one of the non-aqueous electrolytes described above.
优选的，所述二次电池为锂金属电池、锂离子电池或钠离子电池。Preferably, the secondary battery is a lithium metal battery, a lithium ion battery or a sodium ion battery.
本申请提供的非水电解液包括结构式1所示的化合物，在电池充电过程中，能够在负极上发生还原反应开环生成多价阴离子自由基，多价阴离子自由基进一步反应生成较大分子量的多价盐，多价盐会在负极表面形成规整的网状结构SEI膜，该SEI膜具有较大的柔韧性，即使高温下SEI膜也不容易破裂，稳固的SEI膜有助于提高电池的高温循环性能和高温存储性能，延长了电池的循环寿命，推测是由于结构式1所示的化合物在电池充电过程中，能够在负极上发生还原反应开环生成多价阴离子自由基，多价阴离子自由基进一步反应形成较大分子量的多价盐，多价盐具有更好的耐氧化特性，则多价盐在负极表面形成的SEI膜也具有更好的耐氧化特性，可减缓电解液的氧化进程，能够显著提升锂离子电池的高温循环性能以及高温储存性能；另一方面，由于结构式1所示的化合物具有共两个碳原子的双环结构，结构更稳定，其一侧为五元环的环状硫酸酯，另一侧为五元环的环状碳酸酯，硫酸酯基团能在负极表面形成界面膜，抑制溶剂分子在负极的共嵌和还原分解，改善电池的高温性能，而碳酸酯基团也参与成膜能够有效阻止电解液进一步分解，因此少量的添加就可以改变电解液的循环性能，而且还具有良好的阻燃效果，能显著提高电解液的闪点。The non-aqueous electrolyte provided by the present application includes a compound shown in structural formula 1. During the battery charging process, a reduction reaction can occur on the negative electrode to open the ring to generate multivalent anion radicals. The multivalent anion radicals further react to generate multivalent salts with larger molecular weights. The multivalent salts will form a regular network structure SEI film on the surface of the negative electrode. The SEI film has greater flexibility. Even at high temperatures, the SEI film is not easy to break. A stable SEI film helps to improve the high-temperature cycle performance and high-temperature storage performance of the battery and extend the cycle life of the battery. It is speculated that this is because the compound shown in structural formula 1 can undergo a reduction reaction on the negative electrode during the battery charging process to open the ring to generate multivalent anion radicals. The multivalent anion radicals further react to form multivalent salts with larger molecular weights. The multivalent salts have a more Good oxidation resistance, the SEI film formed by the multivalent salt on the negative electrode surface also has better oxidation resistance, which can slow down the oxidation process of the electrolyte, and can significantly improve the high-temperature cycle performance and high-temperature storage performance of the lithium-ion battery; on the other hand, since the compound shown in structural formula 1 has a bicyclic structure with a total of two carbon atoms, the structure is more stable, one side of which is a five-membered ring cyclic sulfate ester, and the other side is a five-membered ring cyclic carbonate ester. The sulfate group can form an interface film on the negative electrode surface, inhibit the co-embedding and reductive decomposition of solvent molecules in the negative electrode, and improve the high-temperature performance of the battery, and the carbonate group also participates in the film formation, which can effectively prevent the electrolyte from further decomposing. Therefore, a small amount of addition can change the cycle performance of the electrolyte, and it also has a good flame retardant effect, which can significantly improve the flash point of the electrolyte.
具体实施方式Detailed ways
为了使本发明所解决的技术问题、技术方案及有益效果更加清楚明白，以下结合实施例，对本发明进行进一步详细说明。应当理解，此处所描述的具体实施例仅仅用以解释本发明，并不用于限定本发明。In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.
本申请提供的一种非水电解液，包括电解质盐、非水有机溶剂和添加剂，所述添加剂包括结构式1所示的化合物：
The present application provides a non-aqueous electrolyte solution, comprising an electrolyte salt, a non-aqueous organic solvent and an additive, wherein the additive comprises a compound represented by structural formula 1:
其中，R1、R2各自独立地选自氢原子、卤素原子、C1-C5的烃基或C1-C5的卤代烃基。 C1-C5的烃基如可以是甲基、乙基、丙基、丁基、戊基、异丙基、异丁基的烷基，或者是乙烯基、丙烯基、丁烯基等烯基，还可以是乙炔基、丙炔基、丁炔基等的炔基。卤素原子包括F、Cl、Br、I、At中的至少一种。Wherein, R 1 and R 2 are each independently selected from a hydrogen atom, a halogen atom, a C1-C5 hydrocarbon group or a C1-C5 halogenated hydrocarbon group. The C1-C5 hydrocarbon group may be an alkyl group such as methyl, ethyl, propyl, butyl, pentyl, isopropyl, isobutyl, or an alkenyl group such as vinyl, propenyl, butenyl, or an alkynyl group such as ethynyl, propynyl, butynyl, etc. The halogen atom may include at least one of F, Cl, Br, I, and At.
电池充电过程中，非水有机溶剂在高温下不稳定，易于在负极表面发生还原分解，同时在负极界面堆积造成电池阻抗持续增加，SEI膜被破坏，影响电池高温条件下的循环性能和存储性能的提升。发明人通过大量研究发现，在非水电解液中加入结构式1所示的化合物作为添加剂，结构式1所示的化合物能够在负极上发生还原反应开环生成多价阴离子自由基，多价阴离子自由基进一步发生反应生成较大分子量的多价盐，多价盐会在负极表面形成规整的网状结构SEI膜，该SEI膜表面具有较大的柔韧性，即使高温下SEI膜也不容易破裂，阻抗增加也相对比较缓慢，能有效减少电解液溶剂在负极上发生分解，减少气体的产生，从而提高锂离子电池在高温条件下的电化学性能；多价盐还具有更好的耐氧化特性，减缓电解液的氧化进程，能够显著提升锂离子电池的高温循环性能以及高温储存性能。During the battery charging process, the non-aqueous organic solvent is unstable at high temperature and is easy to undergo reduction and decomposition on the negative electrode surface. At the same time, the accumulation at the negative electrode interface causes the battery impedance to continue to increase, and the SEI film is destroyed, which affects the battery's cycle performance and storage performance under high temperature conditions. The inventor has found through a large number of studies that the compound shown in structural formula 1 is added to the non-aqueous electrolyte as an additive. The compound shown in structural formula 1 can undergo a reduction reaction on the negative electrode to open the ring to generate multivalent anion radicals, and the multivalent anion radicals further react to generate multivalent salts with larger molecular weights. The multivalent salts will form a regular network structure SEI film on the negative electrode surface. The SEI film surface has greater flexibility, and the SEI film is not easy to break even at high temperatures. The impedance increase is relatively slow, which can effectively reduce the decomposition of the electrolyte solvent on the negative electrode and reduce the generation of gas, thereby improving the electrochemical performance of lithium-ion batteries under high temperature conditions; the multivalent salt also has better oxidation resistance, slows down the oxidation process of the electrolyte, and can significantly improve the high-temperature cycle performance and high-temperature storage performance of lithium-ion batteries.
结构式1所示的化合物，硫酸酯基团能在电池电极表面形成固体电解质相界面膜，抑制溶剂分子在负极的共嵌和还原分解，改善锂离子电池的循环性能和高温性能，且环状碳酸酯基团也能参与成膜能够有效阻止电解液进一步分解，少量添加就可以改变电解液的循环性能，而且还具有良好的阻燃效果，能显著提高电解液的闪点。The compound shown in structural formula 1, the sulfate group can form a solid electrolyte phase interface film on the surface of the battery electrode, inhibit the co-embedding and reductive decomposition of solvent molecules in the negative electrode, improve the cycle performance and high temperature performance of the lithium-ion battery, and the cyclic carbonate group can also participate in the film formation, which can effectively prevent the electrolyte from further decomposing. A small amount of addition can change the cycle performance of the electrolyte, and it also has a good flame retardant effect and can significantly improve the flash point of the electrolyte.
电池充放电过程中，非水电解液中加入结构式1所示的化合物，可在电极表面发生电化学反应，同时能够适度交联形成比较稳定的薄膜结构，从而提高电池电性能。结构式1所示共碳五元环状脂类化合物有助于锂离子电池在充放电过程中形成稳定的SEI膜，进而有效地提高了电池的高温性能，提升电池功率特性，使所制备的锂离子电池在高温条件下同样具有优异的电化学性能。During the battery charging and discharging process, the compound shown in structural formula 1 is added to the non-aqueous electrolyte, an electrochemical reaction can occur on the electrode surface, and at the same time, it can be moderately cross-linked to form a relatively stable film structure, thereby improving the battery's electrical performance. The co-carbon five-membered cyclic lipid compound shown in structural formula 1 helps the lithium-ion battery form a stable SEI film during the charging and discharging process, thereby effectively improving the battery's high-temperature performance and battery power characteristics, so that the prepared lithium-ion battery also has excellent electrochemical performance under high temperature conditions.
结构式1所示的化合物的制备方法具有多种，本领域技术人员可以依据本领域的公知常识知晓上述化合物的制备方法，下面列举其中一种化合物1的制备方法，需要说明的是还可以使用其它反应物生成本申请结构式1所示的化合物都在本申请的保护范围内。There are many methods for preparing the compound shown in Structural Formula 1. Those skilled in the art can know the preparation methods of the above compounds based on the common knowledge in the art. The preparation method of one of the compounds 1 is listed below. It should be noted that other reactants can also be used to produce the compound shown in Structural Formula 1 of this application, all of which are within the scope of protection of this application.
以二氯碳酸乙烯酯(DCEC)与发烟硫酸反应，生成共碳五元环硫酸中，具体合成路线如下：
The specific synthesis route is as follows:
在一些实施例中，所述结构式1所示的化合物选自以下化合物中的至少一种：
In some embodiments, the compound represented by structural formula 1 is selected from at least one of the following compounds:
在一些实施例中，以所述非水电解液的总质量为100％计，所述结构式1所示的化合物的质量百分含量为0.05％～10％。In some embodiments, based on the total mass of the non-aqueous electrolyte being 100%, the mass percentage of the compound represented by Structural Formula 1 is 0.05% to 10%.
在一些优选的实施例中，以所述非水电解液的总质量为100％计，所述结构式1所示的化合物的质量百分含量为0.1％～5％。In some preferred embodiments, based on the total mass of the non-aqueous electrolyte being 100%, the mass percentage of the compound represented by the structural formula 1 is 0.1% to 5%.
在具体的实施例中，非水电解液中结构式1所示的化合物的质量百分含量可以为0.05％、0.08％、0.1％、0.5％、0.8％、1％、1.2％、1.5％、1.8％、2％、2.2％、2.5％、2.8％、3％、3.2％、3.5％、3.8％、4％、4.5％、5％、5.5％、6％、6.5％、7％、7.5％、7.8％、8％、8.5％、9％、9.5％、10％。In a specific embodiment, the mass percentage of the compound shown in structural formula 1 in the non-aqueous electrolyte can be 0.05%, 0.08%, 0.1%, 0.5%, 0.8%, 1%, 1.2%, 1.5%, 1.8%, 2%, 2.2%, 2.5%, 2.8%, 3%, 3.2%, 3.5%, 3.8%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 7.8%, 8%, 8.5%, 9%, 9.5%, or 10%.
当结构式1所示的化合物的质量百分含量处于0.05％～10％范围内时，可以在电极表面发生电化学反应，在电极表面形成结构稳定的薄膜结构，可以有效维持电极表面成膜的稳定性，提升电池性能。以锂电池为例，在电解液中加入结构式1所示的化合物的含量在上述范围内，能够在负极界面形成规整的网状结构、柔韧性大的SEI膜，在高温条件下SEI膜不破裂，且能够减少电解液溶剂在负极上发生分解、氧化反应，减少气体的产生，提高电池的高温存储性能。若结构式1所示的化合物过少，电池充电过程中，结构式1所示的化合物无法在负极界面形成规整的网状结构SEI膜，则难以对电池的性能产生明显的提升效果；若结构式1所示的化合物添加量过多，电解液中的其它种类的添加剂含量降低，影响负极表面的成膜反应，同时可能因其分解产物过多而影响电解液中其他物质的功能发挥。 When the mass percentage of the compound shown in Structural Formula 1 is within the range of 0.05% to 10%, an electrochemical reaction can occur on the electrode surface, forming a thin film structure with a stable structure on the electrode surface, which can effectively maintain the stability of the film formation on the electrode surface and improve the battery performance. Taking lithium batteries as an example, when the content of the compound shown in Structural Formula 1 added to the electrolyte is within the above range, a regular network structure and a flexible SEI film can be formed at the negative electrode interface. The SEI film does not break under high temperature conditions, and the decomposition and oxidation reaction of the electrolyte solvent on the negative electrode can be reduced, reducing the generation of gas and improving the high temperature storage performance of the battery. If the compound shown in Structural Formula 1 is too little, the compound shown in Structural Formula 1 cannot form a regular network structure SEI film at the negative electrode interface during battery charging, and it is difficult to significantly improve the performance of the battery; if the amount of the compound shown in Structural Formula 1 added is too much, the content of other types of additives in the electrolyte is reduced, affecting the film formation reaction on the negative electrode surface, and at the same time, it may affect the function of other substances in the electrolyte due to its excessive decomposition products.
在一些实施例中，所述非水电解液中电解质盐的浓度为0.1mol/L～8mol/L；在一些优选的实施例中，所述非水电解液中电解质盐的浓度为0.5mol/L～2.5mol/L。In some embodiments, the concentration of the electrolyte salt in the non-aqueous electrolyte is 0.1 mol/L to 8 mol/L; in some preferred embodiments, the concentration of the electrolyte salt in the non-aqueous electrolyte is 0.5 mol/L to 2.5 mol/L.
在一些实施例中，所述电解质盐选自锂盐或钠盐。In some embodiments, the electrolyte salt is selected from a lithium salt or a sodium salt.
在优选的实施例中，所述锂盐选自LiPF6、LiBOB、LiDFOB、LiPO2F2、LiBF4、LiSbF6、LiAsF6、LiN(SO2CF3)2、LiN(SO2C2F5)2、LiC(SO2CF3)3、LiN(SO2F)2、LiClO4、LiAlCl4、LiCF3SO3、Li2B10Cl10、LiSO3F、LiTOP(三草酸磷酸锂)、LiDODFP(二氟二草酸磷酸锂)、LiOTFP(四氟草酸磷酸锂)和低级脂肪族羧酸锂盐中的至少一种.In a preferred embodiment, the lithium salt is selected from at least one of LiPF 6 , LiBOB, LiDFOB, LiPO 2 F 2 , LiBF 4 , LiSbF 6 , LiAsF 6 , LiN(SO 2 CF 3 ) 2 , LiN(SO 2 C 2 F 5 ) 2 , LiC(SO 2 CF 3 ) 3 , LiN(SO 2 F) 2 , LiClO 4 , LiAlCl 4 , LiCF 3 SO 3 , Li 2 B 10 Cl 10 , LiSO 3 F, LiTOP (lithium trioxalate phosphate), LiDODFP (lithium difluorodioxalate phosphate), LiOTFP (lithium tetrafluorooxalate phosphate) and lower aliphatic carboxylic acid lithium salts.
在优选的实施例中，所述钠盐选自所述钠盐选自NaPF6、NaClO4、NaAsF6、NaSbF6、NaPOF4、NaPO2F2、NaC4BO8、NaC2BF2O4、NaODFB、NaN(SO2C2F5)2、NaN(SO2CF3)(SO2C4F9)2、NaC(SO2CF3)和Na(C2F5)PF3中的至少一种。In a preferred embodiment, the sodium salt is selected from at least one of NaPF 6 , NaClO 4 , NaAsF 6 , NaSbF 6 , NaPOF 4 , NaPO 2 F 2 , NaC 4 BO 8 , NaC 2 BF 2 O 4 , NaODFB, NaN(SO 2 C 2 F 5 ) 2 , NaN(SO 2 CF 3 )(SO 2 C 4 F 9 ) 2 , NaC(SO 2 CF 3 ) and Na(C 2 F 5 )PF 3 .
在具体的实施例中，电解质盐的浓度可以是0.5mol/L、1mol/L、1.2mol/L、1.5mol/L、2mol/L、2.5mol/L、3mol/L、3.5mol/L、4mol/L、4.5mol/L、5mol/L、6mol/L、7mol/L、8mol/L。In specific embodiments, the concentration of the electrolyte salt can be 0.5mol/L, 1mol/L, 1.2mol/L, 1.5mol/L, 2mol/L, 2.5mol/L, 3mol/L, 3.5mol/L, 4mol/L, 4.5mol/L, 5mol/L, 6mol/L, 7mol/L, or 8mol/L.
在一些实施例中，所述非水电解液还包括辅助添加剂，所述辅助添加剂包括环状硫酸酯类化合物、磺酸内酯类化合物、环状碳酸酯类化合物、不饱和磷酸酯类化合物、硼酸酯类化合物和腈类化合物中的至少一种；In some embodiments, the non-aqueous electrolyte further comprises an auxiliary additive, wherein the auxiliary additive comprises at least one of a cyclic sulfate compound, a sultone compound, a cyclic carbonate compound, an unsaturated phosphate compound, a borate compound, and a nitrile compound;
以所述非水电解液的总质量为100％计，所述辅助添加剂的添加量为0.01％～30％。Based on the total mass of the non-aqueous electrolyte being 100%, the amount of the auxiliary additive added is 0.01% to 30%.
需要说明的是，除非特殊说明，一般情况下，所述辅助添加剂中任意一种可选物质在非水电解液中的添加量为10％以下，优选的，添加量为0.1-5％，更优选的，添加量为0.1％～3％。具体的，所述辅助添加剂中任意一种可选物质的添加量可以为0.05％、0.08％、0.1％、0.5％、0.8％、1％、1.2％、1.5％、1.8％、2％、2.2％、2.5％、2.8％、3％、3.2％、3.5％、3.8％、4％、4.5％、5％、5.5％、6％、6.5％、7％、7.5％、7.8％、8％、8.5％、9％、9.5％、10％。It should be noted that, unless otherwise specified, in general, the amount of any one of the optional substances in the auxiliary additives added to the non-aqueous electrolyte is less than 10%, preferably, the amount added is 0.1-5%, and more preferably, the amount added is 0.1% to 3%. Specifically, the amount of any one of the optional substances in the auxiliary additives can be 0.05%, 0.08%, 0.1%, 0.5%, 0.8%, 1%, 1.2%, 1.5%, 1.8%, 2%, 2.2%, 2.5%, 2.8%, 3%, 3.2%, 3.5%, 3.8%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 7.8%, 8%, 8.5%, 9%, 9.5%, 10%.
在一些优选的实施例中，所述环状硫酸酯类化合物选自硫酸乙烯酯(DTD)、硫酸丙烯酯、或甲基硫酸乙烯酯中的至少一种；In some preferred embodiments, the cyclic sulfate ester compound is selected from vinyl sulfate (DTD), propylene sulfate, or at least one of methyl vinyl sulfate;
所述磺酸内酯类化合物选自1,3-丙烷磺酸内酯、1,4-丁烷磺酸内酯或1,3-丙烯磺酸内酯(PS)中的至少一种；The sultone compound is selected from at least one of 1,3-propane sultone, 1,4-butane sultone or 1,3-propylene sultone (PS);
所述环状碳酸酯类化合物选自碳酸丙烯酯(PC)、碳酸亚乙烯酯(VC)、碳酸乙烯亚乙酯、亚甲基碳酸乙烯酯、三氟甲基碳酸乙烯酯、双氟代碳酸乙烯酯或氟代碳酸乙烯酯或结构式2所示化合物中的至少一种；
The cyclic carbonate compound is selected from at least one of propylene carbonate (PC), vinylene carbonate (VC), ethylene carbonate, methylene carbonate, trifluoromethyl carbonate, bisfluoroethylene carbonate or fluoroethylene carbonate or the compound shown in formula 2;
所述结构式2中，R21、R22、R23、R24、R25、R26各自独立地选自氢原子、卤素原子、C1-C5基团中的一种。In the structural formula 2, R 21 , R 22 , R 23 , R 24 , R 25 , and R 26 are each independently selected from a hydrogen atom, a halogen atom, and a C1-C5 group.
在一些实施例中，所述结构式2所示的化合物包括In some embodiments, the compound represented by structural formula 2 comprises
中的至少一种。 At least one of .
所述磷酸酯类化合物选自三(三甲基硅烷)磷酸酯、三(三甲基硅烷)亚磷酸酯或结构式3所示化合物中的至少一种：
The phosphate compound is selected from at least one of tris(trimethylsilyl)phosphate, tris(trimethylsilyl)phosphite or the compound shown in structural formula 3:
所述结构式3中，R31、R32、R33各自独立的选自C1-C5的饱和烃基、不饱和烃基、卤代烃基、-Si(CmH2m+1)3，m为1～3的自然数，且R31、R32、R33中至少有一个为不饱和烃基。In the structural formula 3, R 31 , R 32 and R 33 are independently selected from C1-C5 saturated hydrocarbon groups, unsaturated hydrocarbon groups, halogenated hydrocarbon groups, and -Si(C m H 2m+1 ) 3 , m is a natural number of 1 to 3, and at least one of R 31 , R 32 and R 33 is an unsaturated hydrocarbon group.
在一些实施例中，所述结构式3所示化合物可为磷酸三炔丙酯、二炔丙基甲基磷酸酯、二炔丙基乙基磷酸酯、二炔丙基丙基磷酸酯、二炔丙基三氟甲基磷酸酯、二炔丙基-2,2,2-三氟乙基磷酸酯、二炔丙基-3,3,3-三氟丙基磷酸酯、二炔丙基六氟异丙基磷酸酯、磷酸三烯丙酯、二烯丙基甲基磷酸酯、二烯丙基乙基磷酸酯、二烯丙基丙基磷酸酯、二烯丙基三氟甲基磷酸酯、二烯丙基-2,2,2-三氟乙基磷酸酯、二烯丙基-3,3,3-三氟丙基磷酸酯、二烯丙基六氟异 丙基磷酸酯中的至少一种。In some embodiments, the compound shown in the structural formula 3 can be tripropargyl phosphate, dipropargyl methyl phosphate, dipropargyl ethyl phosphate, dipropargyl propyl phosphate, dipropargyl trifluoromethyl phosphate, dipropargyl-2,2,2-trifluoroethyl phosphate, dipropargyl-3,3,3-trifluoropropyl phosphate, dipropargyl hexafluoroisopropyl phosphate, triallyl phosphate, diallyl methyl phosphate, diallyl ethyl phosphate, diallyl propyl phosphate, diallyl trifluoromethyl phosphate, diallyl-2,2,2-trifluoroethyl phosphate, diallyl-3,3,3-trifluoropropyl phosphate, diallyl hexafluoroisopropyl phosphate. At least one of propyl phosphates.
所述硼酸酯类化合物选自三(三甲基硅烷)硼酸酯和三(三乙基硅烷)硼酸酯中的至少一种；The borate compound is selected from at least one of tris(trimethylsilyl)borate and tris(triethylsilyl)borate;
所述腈类化合物包括丁二腈、戊二腈、乙二醇双(丙腈)醚、己烷三腈、己二腈、庚二腈、辛二腈、壬二腈、癸二腈中的至少一种。The nitrile compound includes at least one of succinonitrile, glutaronitrile, ethylene glycol bis(propionitrile) ether, hexanetrinitrile, adiponitrile, pimelonitrile, suberonitrile, azelaic acid dinitrile and sebaconitrile.
所述非水电解液中，相比于单一添加或是其他现有添加剂的组合，结构式1所示的化合物与所述辅助添加剂一同添加时，在提升电池性能方面体现出明显的协同提升的作用，说明结构式1所示的化合物与辅助添加剂在电极表面共同成膜能够弥补单一添加的成膜缺陷，得到更加稳定的钝化膜。In the non-aqueous electrolyte, compared with a single addition or a combination of other existing additives, when the compound shown in Structural Formula 1 is added together with the auxiliary additive, a significant synergistic improvement effect is shown in improving battery performance, indicating that the compound shown in Structural Formula 1 and the auxiliary additive can form a film together on the electrode surface to make up for the film-forming defects of a single addition and obtain a more stable passivation film.
在另一些实施例中，所述辅助添加剂还包括其它能改善电池性能的添加剂：例如，提升电池安全性能的添加剂，具体如氟代磷酸酯、环磷腈等阻燃添加剂，或叔戊基苯、叔丁基苯等防过充添加剂。In other embodiments, the auxiliary additives also include other additives that can improve battery performance: for example, additives that enhance battery safety performance, such as flame retardant additives such as fluorophosphates and cyclophosphazenes, or overcharge prevention additives such as tert-amylbenzene and tert-butylbenzene.
在一些实施例中，所述溶剂包括醚类溶剂、腈类溶剂、碳酸酯类溶剂、羧酸酯类溶剂和砜类溶剂中的至少一种。In some embodiments, the solvent includes at least one of an ether solvent, a nitrile solvent, a carbonate solvent, a carboxylate solvent, and a sulfone solvent.
在一些实施例中，醚类溶剂包括环状醚或链状醚，优选为碳原子数3～10的链状醚及碳原子数3～6的环状醚，环状醚具体可以包括但不限于是1,3-二氧戊烷(DOL)、1,4-二氧惡烷(DX)、冠醚、四氢呋喃(THF)、2-甲基四氢呋喃(2-CH3-THF)，2-三氟甲基四氢呋喃(2-CF3-THF)中的至少一种；所述链状醚具体可以包括但不限于是二甲氧基甲烷、二乙氧基甲烷、乙氧基甲氧基甲烷、乙二醇二正丙基醚、乙二醇二正丁基醚、二乙二醇二甲基醚。由于链状醚与锂离子的溶剂化能力高、可提高离子解离性，因此特别优选粘性低、可赋予高离子电导率的二甲氧基甲烷、二乙氧基甲烷、乙氧基甲氧基甲烷。醚类化合物可以单独使用一种，也可以以任意的组合及比率组合使用两种以上。醚类化合物的添加量没有特殊限制，在不显著破坏本发明高压实锂离子电池效果的范围内是任意的，在非水溶剂体积比为100％中通常体积比为1％以上、优选体积比为2％以上、更优选体积比为3％以上，另外，通常体积比为30％以下、优选体积比为25％以下、更优选体积比为20％以下。在将两种以上醚类化合物组合使用的情况下，使醚类化合物的总量满足上述范围即可。醚类化合物的添加量在上述的优选范围内时，易于确保由链状醚的锂离子离解度的提高和粘度降低所带来的离子电导率的改善效果。另外，负极活性物质为碳素材料的情况下，可抑制因链状醚与锂离子共同发生共嵌入的现象，因此能够使输入输出特性、充放电速率特性达到适当的范围。In some embodiments, the ether solvent includes a cyclic ether or a chain ether, preferably a chain ether with 3 to 10 carbon atoms and a cyclic ether with 3 to 6 carbon atoms. The cyclic ether may specifically include, but is not limited to, at least one of 1,3-dioxolane (DOL), 1,4-dioxolane (DX), crown ether, tetrahydrofuran (THF), 2-methyltetrahydrofuran (2-CH 3 -THF), and 2-trifluoromethyltetrahydrofuran (2-CF 3 -THF); the chain ether may specifically include, but is not limited to, dimethoxymethane, diethoxymethane, ethoxymethoxymethane, ethylene glycol di-n-propyl ether, ethylene glycol di-n-butyl ether, and diethylene glycol dimethyl ether. Since the chain ether has a high solvation ability with lithium ions and can improve ion dissociation, dimethoxymethane, diethoxymethane, and ethoxymethoxymethane, which have low viscosity and can impart high ionic conductivity, are particularly preferred. The ether compound can be used alone or in any combination and ratio. There is no special restriction on the amount of ether compounds added, and it is arbitrary within the range that does not significantly damage the effect of the high-density lithium-ion battery of the present invention. In the case where the volume ratio of the non-aqueous solvent is 100%, the volume ratio is usually 1% or more, preferably 2% or more, and more preferably 3% or more. In addition, the volume ratio is usually 30% or less, preferably 25% or less, and more preferably 20% or less. When two or more ether compounds are used in combination, the total amount of the ether compounds can be made to meet the above range. When the amount of ether compounds added is within the above preferred range, it is easy to ensure the improvement of ion conductivity brought about by the increase in lithium ion dissociation degree and the decrease in viscosity of the chain ether. In addition, when the negative electrode active material is a carbon material, the phenomenon of co-embedding of chain ethers and lithium ions can be suppressed, so that the input-output characteristics and charge-discharge rate characteristics can reach an appropriate range.
在一些实施例中，腈类溶剂包括乙腈、戊二腈、丙二腈中的至少一种。In some embodiments, the nitrile solvent includes at least one of acetonitrile, glutaronitrile, and malononitrile.
在一些实施例中，碳酸酯类溶剂包括环状碳酸酯或链状碳酸酯，环状碳酸酯包括碳酸乙烯酯(EC)、碳酸丙烯酯(PC)、γ-丁内酯(GBL)、碳酸亚丁酯(BC)中的至少一种；链状碳酸酯包括碳酸二甲酯(DMC)、碳酸甲乙酯(EMC)、碳酸二乙酯(DEC)、碳酸二丙酯(DPC)中的至少一种。环状碳酸酯的含量没有特殊限制，在不显著破坏本发明高压实锂离子电池效果的范围内是任意的，但在单独使用一种的情况下其含量的下限相对于非水电解液的溶剂总量来说，通常体积比为3％以上、优选体积比为5％以上。通过设定该范围，可避免由于非水电解液的介电常数降低而导致电导率降低，易于使非水电解质电池的大电流放电特 性、相对于负极的稳定性、循环特性达到良好的范围。另外，上限通常体积比为90％以下、优选体积比为85％以下、更优选体积比为80％以下。通过设定该范围，可提高非水电解液的氧化/还原耐性，从而有助于提高高温保存时的稳定性。链状碳酸酯的含量没有特殊限定，相对于非水电解液的溶剂总量，通常为体积比为15％以上、优选体积比为20％以上、更优选体积比为25％以上。另外，通常体积比为90％以下、优选体积比为85％以下、更优选体积比为80％以下。通过使链状碳酸酯的含量在上述范围，容易使非水电解液的粘度达到适当范围，抑制离子电导率的降低，进而有助于使非水电解质电池的输出特性达到良好的范围。在组合使用两种以上链状碳酸酯的情况下，使链状碳酸酯的总量满足上述范围即可。In some embodiments, the carbonate solvent includes a cyclic carbonate or a chain carbonate, and the cyclic carbonate includes at least one of ethylene carbonate (EC), propylene carbonate (PC), γ-butyrolactone (GBL), and butylene carbonate (BC); the chain carbonate includes at least one of dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), diethyl carbonate (DEC), and dipropyl carbonate (DPC). There is no special restriction on the content of the cyclic carbonate, and it is arbitrary within the range that does not significantly damage the effect of the high-density lithium-ion battery of the present invention, but when one is used alone, the lower limit of its content is generally 3% or more by volume, preferably 5% or more by volume, relative to the total amount of solvent in the non-aqueous electrolyte. By setting this range, the decrease in conductivity due to the decrease in the dielectric constant of the non-aqueous electrolyte can be avoided, and the high-current discharge characteristics of the non-aqueous electrolyte battery can be easily improved. The upper limit is usually 90% by volume or less, preferably 85% by volume or less, and more preferably 80% by volume or less. By setting this range, the oxidation/reduction resistance of the non-aqueous electrolyte can be improved, thereby helping to improve the stability during high temperature storage. The content of the chain carbonate is not particularly limited, and is usually 15% or more by volume, preferably 20% or more by volume, and more preferably 25% or more by volume relative to the total amount of solvent in the non-aqueous electrolyte. In addition, the volume ratio is usually 90% or less, preferably 85% or less, and more preferably 80% or less by volume. By making the content of the chain carbonate in the above range, it is easy to make the viscosity of the non-aqueous electrolyte reach an appropriate range, suppress the reduction of ionic conductivity, and then help to make the output characteristics of the non-aqueous electrolyte battery reach a good range. When two or more chain carbonates are used in combination, the total amount of the chain carbonates can be satisfied in the above range.
在一些实施例中，还可优选使用具有氟原子的链状碳酸酯类(以下简称为“氟化链状碳酸酯”)。氟化链状碳酸酯所具有的氟原子的个数只要为1以上则没有特殊限制，但通常为6以下、优选4以下。氟化链状碳酸酯具有多个氟原子的情况下，这些氟原子相互可以键合于同一个碳上，也可以键合于不同的碳上。作为氟化链状碳酸酯，可列举，氟化碳酸二甲酯衍生物、氟化碳酸甲乙酯衍生物、氟化碳酸二乙酯衍生物等。In certain embodiments, it is also possible to preferably use chain carbonates with fluorine atoms (hereinafter referred to as "fluorinated chain carbonates"). The number of fluorine atoms possessed by the fluorinated chain carbonate is not particularly limited as long as it is more than 1, but is generally less than 6, preferably less than 4. When the fluorinated chain carbonate has a plurality of fluorine atoms, these fluorine atoms can be bonded to the same carbon or to different carbons. As the fluorinated chain carbonate, fluorinated dimethyl carbonate derivatives, fluorinated ethyl methyl carbonate derivatives, fluorinated diethyl carbonate derivatives, etc. can be listed.
羧酸酯类溶剂包括环状羧酸酯和/或链状碳酸酯。作为环状羧酸酯的例子，可以列举如：γ-丁内酯、γ-戊内酯、δ-戊内酯中的至少一种。作为链状碳酸酯的例子，羧酸酯类溶剂包括乙酸甲酯(MA)、乙酸乙酯(EA)、乙酸丙酯(EP)、乙酸丁酯、丙酸丙酯(PP)、丙酸丁酯中的至少一种。Carboxylic acid ester solvents include cyclic carboxylic acid esters and/or chain carbonates. Examples of cyclic carboxylic acid esters include at least one of γ-butyrolactone, γ-valerolactone, and δ-valerolactone. Examples of chain carbonates include at least one of methyl acetate (MA), ethyl acetate (EA), propyl acetate (EP), butyl acetate, propyl propionate (PP), and butyl propionate.
在一些实施例中，砜类溶剂包括环状砜和链状砜，但优选地，在为环状砜的情况下，通常为碳原子数3～6、优选碳原子数3～5，在为链状砜的情况下，通常为碳原子数2～6、优选碳原子数2～5的化合物。砜类溶剂的添加量没有特殊限制，在不显著破坏本发明高压实锂离子电池效果的范围内是任意的，相对于非水电解液的溶剂总量，通常体积比为0.3％以上、优选体积比为0.5％以上、更优选体积比为1％以上，另外，通常体积比为40％以下、优选体积比为35％以下、更优选体积比为30％以下。在组合使用两种以上砜类溶剂的情况下，使砜类溶剂的总量满足上述范围即可。砜类溶剂的添加量在上述范围内时，倾向于获得高温保存稳定性优异的电解液。In some embodiments, the sulfone solvent includes a cyclic sulfone and a chain sulfone, but preferably, in the case of a cyclic sulfone, it is generally a compound having 3 to 6 carbon atoms, preferably 3 to 5 carbon atoms, and in the case of a chain sulfone, it is generally a compound having 2 to 6 carbon atoms, preferably 2 to 5 carbon atoms. There is no particular limitation on the amount of sulfone solvent added, and it is arbitrary within the range that does not significantly damage the effect of the high-pressure lithium-ion battery of the present invention. Relative to the total amount of solvent in the non-aqueous electrolyte, the volume ratio is generally 0.3% or more, preferably 0.5% or more, and more preferably 1% or more. In addition, the volume ratio is generally 40% or less, preferably 35% or less, and more preferably 30% or less. In the case of using two or more sulfone solvents in combination, the total amount of the sulfone solvents can be made to meet the above range. When the amount of sulfone solvent added is within the above range, an electrolyte with excellent high-temperature storage stability tends to be obtained.
在优选的实施例中，所述溶剂为环状碳酸酯和链状碳酸酯的混合物。In a preferred embodiment, the solvent is a mixture of cyclic carbonate and linear carbonate.
本发明的另一实施例提供了一种二次电池，包括正极、负极以及如上所述的非水电解液。Another embodiment of the present invention provides a secondary battery including a positive electrode, a negative electrode, and the non-aqueous electrolyte as described above.
所述二次电池由于采用了如上所述的非水电解液，能够在正极和负极上形成性能优异的钝化膜，进而有效地提高了电池的高温存储性能和高温循环性能，提升电池功率特性。Since the secondary battery adopts the non-aqueous electrolyte as described above, it can form a passivation film with excellent performance on the positive electrode and the negative electrode, thereby effectively improving the high-temperature storage performance and high-temperature cycle performance of the battery and enhancing the battery power characteristics.
在优选的实施例中，所述二次电池为锂金属电池、锂离子电池、锂硫电池、钠离子电池等。In a preferred embodiment, the secondary battery is a lithium metal battery, a lithium ion battery, a lithium sulfur battery, a sodium ion battery, etc.
在一些实施例中，所述正极包括正极材料层，所述正极材料层包括正极活性材料，正极活性材料的种类没有特别限制，只要是能够可逆地嵌入/脱嵌金属离子(如锂离子或钠离子)的正极活性材料或转换型正极材料即可。In some embodiments, the positive electrode includes a positive electrode material layer, and the positive electrode material layer includes a positive electrode active material. The type of the positive electrode active material is not particularly limited, as long as it is a positive electrode active material or a conversion positive electrode material that can reversibly embed/de-embed metal ions (such as lithium ions or sodium ions).
在优选的实施例中，所述二次电池为锂离子电池，所述锂离子电池的正极活性材料的种类及含量不受限制，可以根据实际需求进行选择，其正极活性材料可选自LiFe1-x’M’x’PO4、 LiMn2-y’My’O4和LiNixCoyMnzM1-x-y-zO2中的至少一种，其中，M’选自Mn、Mg、Co、Ni、Cu、Zn、Al、Sn、B、Ga、Cr、Sr、V或Ti中的至少一种，M选自Fe、Co、Ni、Mn、Mg、Cu、Zn、Al、Sn、B、Ga、Cr、Sr、V或Ti中的至少一种，且0≤x’＜1，0≤y’≤1，0≤y≤1，0≤x≤1，0≤z≤1，x+y+z≤1，所述正极活性材料还可以选自硫化物、硒化物、卤化物中的一种或几种。In a preferred embodiment, the secondary battery is a lithium ion battery. The type and content of the positive electrode active material of the lithium ion battery are not limited and can be selected according to actual needs. The positive electrode active material can be selected from LiFe 1-x' M'x' PO 4 , At least one of LiMn2-y'My'O4 and LiNixCoyMnzM1 - xyzO2 , wherein M' is selected from at least one of Mn, Mg, Co, Ni, Cu, Zn, Al, Sn, B, Ga, Cr, Sr, V or Ti, M is selected from at least one of Fe, Co, Ni, Mn, Mg, Cu, Zn, Al, Sn, B, Ga, Cr, Sr, V or Ti, and 0≤x'＜1, 0≤y'≤1, 0≤y≤1, 0≤x≤1, 0≤z≤1, x+y+z≤1, and the positive electrode active material can also be selected from one or more of sulfides, selenides and halides.
优选地，所述正极活性材料可选自LiCoO2、LiNiO2、LiMnO2、LiNixCoyMnzO2、LiNi1-aCoaO2、LiNi1-aMnaO2、LiCo1-aMnaO2、LiNix1Coy1Mnz1O4、LiMn2O4、LiMn2-bNibO4、LiMn2-bCobO4、Li2MnO4、LiV3O8、LiCoPO4、LiFePO4中的至少一种，其中，0<x<1，0<y<1，0<z<1，x+y+z＝1，0<a<1，0<x1<2，0<y1<2，0<z1<2，x1+y1+z1＝2，0<b<2，所述正极活性材料还可以选自硫化物、硒化物、卤化物中的一种或几种。Preferably, the positive electrode active material can be selected from LiCoO2 , LiNiO2 , LiMnO2 , LiNixCoyMnzO2 , LiNi1 -aCoaO2 , LiNi1 - aMnaO2 , LiCo1 -aMnaO2, LiNix1Coy1Mnz1O4 , LiMn2O4 , LiMn2 - bNibO4 , LiMn2 - bCobO4 , Li2MnO4 , LiV3O8 , LiCoPO4, LiFePO4 , 4 , wherein 0<x<1, 0<y<1, 0<z<1, x+y+z＝1, 0<a<1, 0<x1<2, 0<y1<2, 0<z1<2, x1+y1+z1＝2, 0<b<2, and the positive electrode active material can also be selected from one or more of sulfides, selenides, and halides.
在优选的实施例中，所述二次电池为钠离子电池，所述钠离子电池的正极活性材料的种类及含量不受限制，可以根据实际需求进行选择。优选地，所述正极活性材料可选自金属钠、碳材料、合金材料、过镀金属氧化物、过镀金属硫化物、磷基材料、钛酸盐材料、普鲁士蓝类材料、含钠的层状氧化物、含钠的硫酸盐类化合物、含钠的磷酸盐类化合物中的一种或几种。所述碳材料可选自石墨、软碳、硬碳中的一种或几种，所述合金材料可选自由Si、Ge、Sn、Pb、Sb中的至少两种组成的合金材料，所述合金材料还可选自由Si、Ge、Sn、Pb、Sb中的至少一种与C组成的合金材料，所述过镀金属氧化物和所述过镀金属硫化物的化学式为M1xNy，M1可选自Fe、Co、Ni、Cu、Mn、Sn、Mo、Sb、V中的一种或几种，N选自O或S，更为优选的，所述过渡金属氧化物为NaNieFefMnpO2(e+f+p＝1，0≤e≤1，0≤f≤1，0≤p≤1)或NaNieCofMnpO2(e+f+p＝1，0≤m≤1，0≤f≤1，0≤p≤1)，所述磷基材料可选自红磷、白磷、黑磷中的一种或几种。所述磷酸盐的化学式为Na3(MO1-gPO4)2F1+2g，0≤g≤1，M选自Al、V、Ge、Fe、Ga中的至少一种，更为优选的，所述磷酸盐为Na3(VPO4)2F3或Na3(VOPO4)2F；和/或所述磷酸盐的化学式为Na2MPO4F，M选自Fe、Mn中的至少一种，更为优选的，所述磷酸盐为Na2FePO4F或Na2MnPO4F。所述硫酸盐的化学式为Na2M(SO4)2·2H2O，M可选自Cr、Fe、Co、Ni、Cu、Mn、Sn、Mo、Sb、V中的至少一种。所述钛酸盐材料可选自Na2Ti3O7、Na2Ti6O13、Na4Ti5O12、Li4Ti5O12、NaTi2(PO4)3中的一种或几种，所述普鲁士蓝类材料的分子式为NaxM[M′(CN)6]y·zH2O，其中，M为过渡金属，M′为过渡金属，0<x≤2，0.8≤y<1，0<z≤20，更为优选的，所述普鲁士蓝类材料为NaxMn[Fe(CN)6]y·nH2O(0＜x≤2，0＜y≤1，0＜z≤10)或NaxFe[Fe(CN)6]y·nH2O(0＜x≤2，0＜y≤1，0＜z≤10)。In a preferred embodiment, the secondary battery is a sodium ion battery, and the type and content of the positive electrode active material of the sodium ion battery are not limited and can be selected according to actual needs. Preferably, the positive electrode active material can be selected from one or more of metallic sodium, carbon materials, alloy materials, overplated metal oxides, overplated metal sulfides, phosphorus-based materials, titanate materials, Prussian blue materials, sodium-containing layered oxides, sodium-containing sulfate compounds, and sodium-containing phosphate compounds. The carbon material may be selected from one or more of graphite, soft carbon and hard carbon; the alloy material may be selected from an alloy material composed of at least two of Si, Ge, Sn, Pb and Sb; the alloy material may also be selected from an alloy material composed of at least one of Si, Ge, Sn, Pb and Sb and C; the chemical formula of the overplated metal oxide and the overplated metal sulfide is M1xNy , M1 may be selected from one or more of Fe, Co , Ni , Cu, Mn, Sn, Mo, Sb and V, N is selected from O or S, more preferably, the transition metal oxide is NaNieFefMnpO2 (e+f+p＝1 , 0≤e≤1 , 0≤f≤1 , 0≤p≤1) or NaNieCofMnpO2 (e+f+p＝1, 0≤m≤1 , 0≤f≤1, 0≤p≤1); the phosphorus-based material may be selected from one or more of red phosphorus, white phosphorus and black phosphorus. The chemical formula of the phosphate is Na 3 (MO 1-g PO 4 ) 2 F 1+2g , 0≤g≤1, M is selected from at least one of Al, V, Ge, Fe, and Ga, more preferably, the phosphate is Na 3 (VPO 4 ) 2 F 3 or Na 3 (VOPO 4 ) 2 F; and/or the chemical formula of the phosphate is Na 2 MPO 4 F, M is selected from at least one of Fe and Mn, more preferably, the phosphate is Na 2 FePO 4 F or Na 2 MnPO 4 F. The chemical formula of the sulfate is Na 2 M(SO 4 ) 2 ·2H 2 O, M can be selected from at least one of Cr, Fe, Co, Ni, Cu, Mn, Sn, Mo, Sb, and V. The titanate material may be selected from one or more of Na 2 Ti 3 O 7 , Na 2 Ti 6 O 13 , Na 4 Ti 5 O 12 , Li 4 Ti 5 O 12 , and NaTi 2 (PO 4 ) 3 . The molecular formula of the Prussian blue material is Na x M[M′(CN) 6 ] y ·zH 2 O, wherein M is a transition metal, M′ is a transition metal, 0<x≤2, 0.8≤y<1, and 0<z≤20. More preferably, the Prussian blue material is Na x Mn[Fe(CN) 6 ] y ·nH 2 O (0＜x≤2, 0＜y≤1, 0＜z≤10) or Na x Fe[Fe(CN) 6 ] y ·nH 2 O (0＜x≤2, 0＜y≤1, 0＜z≤10).
在一些实施例中，所述正极还包括正极集流体，所述正极材料层设置于所述正极集流体的表面。In some embodiments, the positive electrode further includes a positive electrode current collector, and the positive electrode material layer is disposed on a surface of the positive electrode current collector.
所述正极集流体选自可传导电子的金属材料，优选的，所述正极集流体包括铝、镍、锡、铜、不锈钢的至少一种。The positive electrode current collector is selected from metal materials that can conduct electrons. Preferably, the positive electrode current collector includes at least one of aluminum, nickel, tin, copper, and stainless steel.
在一些实施例中，所述正极材料层还包括正极粘结剂和正极导电剂，所述正极活性材料、正极粘结剂和正极导电剂共混得到所述正极材料层。In some embodiments, the positive electrode material layer further includes a positive electrode binder and a positive electrode conductor, and the positive electrode active material, the positive electrode binder and the positive electrode conductor are blended to obtain the positive electrode material layer.
所述正极粘结剂包括聚偏氟乙烯、偏氟乙烯的共聚物、聚四氟乙烯、偏氟乙烯-六氟丙烯 的共聚物、四氟乙烯-六氟丙烯的共聚物、四氟乙烯-全氟烷基乙烯基醚的共聚物、乙烯-四氟乙烯的共聚物、偏氟乙烯-四氟乙烯的共聚物、偏氟乙烯-三氟乙烯的共聚物、偏氟乙烯-三氯乙烯的共聚物、偏氟乙烯-氟代乙烯的共聚物、偏氟乙烯-六氟丙烯-四氟乙烯的共聚物、热塑性聚酰亚胺、聚乙烯及聚丙烯等热塑性树脂；丙烯酸类树脂；羟甲基纤维素钠；以及苯乙烯丁二烯橡胶中的至少一种。The positive electrode binder includes polyvinylidene fluoride, a copolymer of vinylidene fluoride, polytetrafluoroethylene, vinylidene fluoride-hexafluoropropylene The invention relates to a copolymer of tetrafluoroethylene-hexafluoropropylene, a copolymer of tetrafluoroethylene-perfluoroalkyl vinyl ether, a copolymer of ethylene-tetrafluoroethylene, a copolymer of vinylidene fluoride-tetrafluoroethylene, a copolymer of vinylidene fluoride-trifluoroethylene, a copolymer of vinylidene fluoride-trichloroethylene, a copolymer of vinylidene fluoride-fluoroethylene, a copolymer of vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene, a thermoplastic resin such as thermoplastic polyimide, polyethylene and polypropylene; an acrylic resin; sodium hydroxymethyl cellulose; and at least one of styrene butadiene rubber.
所述正极导电剂包括导电炭黑、导电碳球、导电石墨、导电碳纤维、碳纳米管、石墨烯或还原氧化石墨烯中的至少一种。The positive electrode conductive agent includes at least one of conductive carbon black, conductive carbon balls, conductive graphite, conductive carbon fibers, carbon nanotubes, graphene or reduced graphene oxide.
在一些实施例中，当所述二次电池为锂离子电池时，所述负极包括负极活性材料，所述负极活性材料包括碳基负极、硅基负极、锡基负极、锂负极、钠负极、钾负极、镁负极、锌负极和铝负极中的至少一种。其中碳基负极可包括石墨、硬碳、软碳、石墨烯、中间相碳微球等；硅基负极可包括硅材料、硅的氧化物、硅碳复合材料以及硅合金材料等；锡基负极可包括锡、锡碳、锡氧、锡金属化合物；锂基负极可包括金属锂或锂合金。锂合金具体可以是锂硅合金、锂钠合金、锂钾合金、锂铝合金、锂锡合金和锂铟合金中的至少一种。In some embodiments, when the secondary battery is a lithium-ion battery, the negative electrode includes a negative electrode active material, and the negative electrode active material includes at least one of a carbon-based negative electrode, a silicon-based negative electrode, a tin-based negative electrode, a lithium negative electrode, a sodium negative electrode, a potassium negative electrode, a magnesium negative electrode, a zinc negative electrode, and an aluminum negative electrode. The carbon-based negative electrode may include graphite, hard carbon, soft carbon, graphene, mesophase carbon microspheres, etc.; the silicon-based negative electrode may include silicon materials, silicon oxides, silicon-carbon composite materials, and silicon alloy materials; the tin-based negative electrode may include tin, tin carbon, tin oxygen, and tin metal compounds; the lithium-based negative electrode may include metallic lithium or a lithium alloy. The lithium alloy may specifically be at least one of a lithium-silicon alloy, a lithium-sodium alloy, a lithium-potassium alloy, a lithium-aluminum alloy, a lithium-tin alloy, and a lithium-indium alloy.
在优选实施例中，当所述二次电池为钠离子电池时，其负极活性材料包括金属钠、石墨、软碳、硬碳、碳纤维、中间相碳微球、硅基材料、锡基材料、钛酸锂或其他能与钠形成合金材料的金属等中的至少一种。其中，所述合金材料还可选自由Si、Ge、Sn、Pb、Sb中的至少一种与C组成的合金材料，所述石墨可选自人造石墨、天然石墨以及改性石墨中的至少一种；所述硅基材料可选自单质硅、硅氧化合物、硅碳复合物、硅合金中的至少一种；所述锡基材料可选自单质锡、锡氧化合物、锡合金中的至少一种。In a preferred embodiment, when the secondary battery is a sodium ion battery, its negative electrode active material includes at least one of metallic sodium, graphite, soft carbon, hard carbon, carbon fiber, mesophase carbon microspheres, silicon-based materials, tin-based materials, lithium titanate or other metals that can form alloy materials with sodium. Among them, the alloy material can also be selected from an alloy material composed of at least one of Si, Ge, Sn, Pb, Sb and C, the graphite can be selected from at least one of artificial graphite, natural graphite and modified graphite; the silicon-based material can be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, and silicon alloys; the tin-based material can be selected from at least one of elemental tin, tin oxide compounds, and tin alloys.
在一些实施例中，所述负极还包括负极集流体，所述负极材料层设置于所述负极集流体的表面。所述负极集流体选自可传导电子的金属材料，优选的，所述负极集流体包括Al、Ni、锡、铜、不锈钢的至少一种，在更优选的实施例中，所述负极集流体选自铜箔。In some embodiments, the negative electrode further comprises a negative electrode current collector, and the negative electrode material layer is disposed on the surface of the negative electrode current collector. The negative electrode current collector is selected from a metal material that can conduct electrons, preferably, the negative electrode current collector comprises at least one of Al, Ni, tin, copper, and stainless steel, and in a more preferred embodiment, the negative electrode current collector is selected from copper foil.
在一些实施例中，所述负极材料层还包括有负极粘结剂和负极导电剂，所述负极活性材料、所述负极粘结剂和所述负极导电剂共混得到所述负极材料层。所述负极粘结剂和负极导电剂可分别与所述正极粘接剂和正极导电剂相同，在此不再赘述。In some embodiments, the negative electrode material layer further includes a negative electrode binder and a negative electrode conductive agent, and the negative electrode active material, the negative electrode binder and the negative electrode conductive agent are mixed to obtain the negative electrode material layer. The negative electrode binder and the negative electrode conductive agent may be the same as the positive electrode binder and the positive electrode conductive agent, respectively, and will not be described in detail here.
在一些实施例中，所述二次电池中还包括有隔膜，所述隔膜位于所述正极和所述负极之间。In some embodiments, the secondary battery further includes a separator, and the separator is located between the positive electrode and the negative electrode.
所述隔膜可为现有常规隔膜，可以是聚合物隔膜、无纺布等，包括但不限于单层PP(聚丙烯)、单层PE(聚乙烯)、双层PP/PE、双层PP/PP和三层PP/PE/PP等隔膜。The diaphragm may be an existing conventional diaphragm, which may be a polymer diaphragm, a non-woven fabric, etc., including but not limited to single-layer PP (polypropylene), single-layer PE (polyethylene), double-layer PP/PE, double-layer PP/PP and triple-layer PP/PE/PP diaphragms.
以下通过实施例对本发明进行进一步的说明。The present invention is further described below by way of examples.
以下实施例和对比例涉及的化合物如下表1所示：The compounds involved in the following examples and comparative examples are shown in Table 1 below:
表1
Table 1
实施例1Example 1
本实施例以制备锂离子电池为例对本发明进行说明，包括以下操作步骤：This embodiment takes the preparation of a lithium ion battery as an example to illustrate the present invention, and includes the following steps:
1)非水电解液的制备：1) Preparation of non-aqueous electrolyte:
将碳酸乙烯酯(EC)、碳酸二乙酯(DEC)和碳酸甲乙酯(EC)按质量比为EC:DEC:EC＝1:1:1进行混合，然后加入六氟磷酸锂(LiPF6)至摩尔浓度为1mol/L、以及结构式1所示的化合物和辅助添加剂，以所述非水电解液的总重量为100％计，非水电解液中结构式1所示的化合物和辅助添加剂种类及含量如表2。Ethylene carbonate (EC), diethyl carbonate (DEC) and ethyl methyl carbonate (EC) were mixed at a mass ratio of EC:DEC:EC=1:1:1, and then lithium hexafluorophosphate (LiPF 6 ) was added to a molar concentration of 1 mol/L, as well as the compound shown in structural formula 1 and auxiliary additives. Based on the total weight of the non-aqueous electrolyte being 100%, the types and contents of the compound shown in structural formula 1 and auxiliary additives in the non-aqueous electrolyte are shown in Table 2.
2)正极片的制备：2) Preparation of positive electrode sheet:
按93:4:3的质量比混合正极活性材料锂镍钴锰氧化物LiNi0.5Co0.2Mn0.3O2，导电碳黑Super-P和粘结剂聚偏二氟乙烯(PVDF)，然后将它们分散在N-甲基-2-吡咯烷酮(NMP)中，得到正极浆料。将浆料均匀涂布在铝箔的两面上，经过烘干、压延和真空干燥，并用超声波焊机焊上铝制引出线后得到正极板，极片的厚度在120-150μm之间。The positive electrode active material lithium nickel cobalt manganese oxide LiNi 0.5 Co 0.2 Mn 0.3 O 2 , conductive carbon black Super-P and binder polyvinylidene fluoride (PVDF) are mixed in a mass ratio of 93:4:3, and then dispersed in N-methyl-2-pyrrolidone (NMP) to obtain a positive electrode slurry. The slurry is evenly coated on both sides of the aluminum foil, dried, rolled and vacuum dried, and welded with an aluminum lead wire using an ultrasonic welder to obtain a positive electrode plate, the thickness of which is between 120-150μm.
3)负极片的制备：3) Preparation of negative electrode sheet:
按94:1:2.5:2.5的质量比混合负极活性材料人造石墨，导电碳黑Super-P，粘结剂丁苯橡胶(SBR)和羧甲基纤维素(CMC)，然后将它们分散在去离子水中，得到负极浆料。将浆料涂布在铜箔的两面上，经过烘干、压延和真空干燥，并用超声波焊机焊上镍制引出线后得到负极片，极片的厚度在120-150μm之间。The negative electrode active material artificial graphite, conductive carbon black Super-P, binder styrene-butadiene rubber (SBR) and carboxymethyl cellulose (CMC) are mixed in a mass ratio of 94:1:2.5:2.5, and then dispersed in deionized water to obtain negative electrode slurry. The slurry is coated on both sides of the copper foil, dried, rolled and vacuum dried, and the nickel lead wire is welded with an ultrasonic welder to obtain the negative electrode sheet, and the thickness of the electrode sheet is between 120-150μm.
4)电芯的制备：4) Preparation of battery cells:
在正极片和负极片之间放置厚度为20μm的三层隔膜，然后将正极片、负极片和隔膜组成的三明治结构进行卷绕，再将卷绕体压扁后放入铝箔包装袋，在75℃下真空烘烤48h，得 到待注液的电芯。A three-layer separator with a thickness of 20 μm was placed between the positive electrode sheet and the negative electrode sheet, and then the sandwich structure consisting of the positive electrode sheet, the negative electrode sheet and the separator was wound, and then the wound body was flattened and placed in an aluminum foil packaging bag, and vacuum-baked at 75°C for 48 hours to obtain to the battery cell to be filled.
5)电芯的注液和化成：5) Battery filling and formation:
在露点控制在-40℃以下的手套箱中，将上述制备的电解液注入电芯中，经真空封装，静止24h。In a glove box with a dew point controlled below -40°C, the prepared electrolyte was injected into the battery cell, vacuum packaged, and left to stand for 24 hours.
然后按以下步骤进行首次充电的常规化成：0.05C恒流充电180min,0.2C恒流充电至3.95V，二次真空封口，然后进一步以0.2C的电流恒流充电至4.2V，常温搁置24h后，以0.2C的电流恒流放电至3.0V，得到一种LiNi0.5Co0.2Mn0.3O2/人造石墨锂离子电池。Then, conventional formation for the first charge was carried out according to the following steps: 0.05C constant current charging for 180 min, 0.2C constant current charging to 3.95 V, secondary vacuum sealing, and then further 0.2C constant current charging to 4.2 V, after being left at room temperature for 24 h, 0.2C constant current discharge to 3.0 V, to obtain a LiNi 0.5 Co 0.2 Mn 0.3 O 2 /artificial graphite lithium ion battery.
实施例2～18Embodiments 2 to 18
实施例2～18用于说明本发明公开的锂离子电池及其制备方法，包括实施例1中大部分操作步骤，其不同之处在于：Examples 2 to 18 are used to illustrate the lithium ion battery and the preparation method thereof disclosed in the present invention, and include most of the operation steps in Example 1, except that:
采用表2或表3中实施例2～18所示的添加剂及含量。The additives and contents shown in Examples 2 to 18 in Table 2 or Table 3 were used.
对比例1-7Comparative Examples 1-7
对比例1～7用于对比说明本发明公开的锂离子电池及其制备方法，包括实施例1中大部分操作步骤，其不同之处在于：Comparative Examples 1 to 7 are used to compare and illustrate the lithium ion battery and the preparation method thereof disclosed in the present invention, and include most of the operation steps in Example 1, except that:
采用表2中对比例1～7所示的添加剂及含量。The additives and contents shown in Comparative Examples 1 to 7 in Table 2 were used.
性能测试Performance Testing
(1)高温储存性能测试(1) High temperature storage performance test
将化成后的锂离子电池在常温下以1C的电流恒流充电至4.2V，再恒流恒压充电至截止电流0.05C，然后以1C的电流恒流放电至3.0V，测量电池初始放电容量D1、初始电池体积V1及初始阻抗F1，然后充至满电在60℃环境中储存30天后，以1C放电至3V，测量电池的保持容量D2、恢复容量D3、储存后阻抗F2及储存后电池体积V2。计算公式如下：The formed lithium-ion battery is charged to 4.2V at a constant current of 1C at room temperature, then charged to a cut-off current of 0.05C at a constant current and voltage, and then discharged to 3.0V at a constant current of 1C, and the initial discharge capacity D1, initial battery volume V1 and initial impedance F1 of the battery are measured. After being fully charged and stored in an environment of 60°C for 30 days, it is discharged to 3V at 1C, and the battery retention capacity D2, recovery capacity D3, impedance F2 after storage and battery volume V2 after storage are measured. The calculation formula is as follows:
电池容量保持率(％)＝保持容量D2/初始容量D1×100％；Battery capacity retention rate (%) = retention capacity D2/initial capacity D1×100%;
电池容量恢复率(％)＝恢复容量D3/初始容量D1×100％；Battery capacity recovery rate (%) = recovery capacity D3/initial capacity D1×100%;
体积膨胀率(％)＝(储存后电池体积V2-初始电池体积V1)/初始电池体积V1×100％；Volume expansion rate (%) = (battery volume after storage V2-initial battery volume V1)/initial battery volume V1×100%;
内阻增长率(％)＝(储存后阻抗F2-初始阻抗F1)/初始阻抗F1×100％。Internal resistance growth rate (%) = (post-storage impedance F2 - initial impedance F1) / initial impedance F1 × 100%.
(2)高温循环性能测试(2) High temperature cycle performance test
将锂离子电池置于恒温45℃的烘箱中，以1C的电流恒流充电至4.2V，再恒压充电至电流下降至0.02C，然后以1C的电流恒流放电至3.0V，如此循环，记录第1周的放电容量和最后一周的放电容量。The lithium-ion battery was placed in an oven at a constant temperature of 45°C, charged to 4.2V at a constant current of 1C, then charged at a constant voltage until the current dropped to 0.02C, and then discharged to 3.0V at a constant current of 1C. This cycle was repeated, and the discharge capacity of the first week and the discharge capacity of the last week were recorded.
按下式计算循环的容量保持率：The capacity retention rate of the cycle is calculated as follows:
电池容量保持率(％)＝最后一周的放电容量/第1周的放电容量×100％。Battery capacity retention rate (%) = discharge capacity in the last week/discharge capacity in the first week×100%.
实施例1-13和对比例1-7电解液参数及测试数据见表2。The electrolyte parameters and test data of Examples 1-13 and Comparative Examples 1-7 are shown in Table 2.
表2
Table 2
从实施例1～9和对比例1的测试结果可以看出，相比于不添加结构式1所示化合物的非水电解液，在非水电解液中添加结构式1所示的化合物作为添加剂，能够有效改善锂离子电池的高温循环容量保持率、高温存储的容量保持率、容量恢复率、体积膨胀率和内阻增长率，说明由结构式1所示的化合物在正负极表面分解形成的钝化膜具有较高的高温稳定性，提升了正负极材料在长期循环中的性能稳定性，提高了锂离子电池在高温下的循环性能和存储性能。从实施例1-9的测试结果可知，随着结构式1所示的化合物的含量提升，锂离子电池的高温存储性能和高温循环性能先提升后降低，尤其是，当化合物的含量为0.5％-5.0％时，锂离子电池具有最佳的综合性能，说明在锂离子电池充放电循环的过程中，电解液中结构式1所示的化合物的含量为0.5％-5.0％时，能够保证所形成的SEI膜规整且薄厚适中，稳定性更好From the test results of Examples 1 to 9 and Comparative Example 1, it can be seen that compared with the non-aqueous electrolyte without adding the compound shown in Structural Formula 1, adding the compound shown in Structural Formula 1 as an additive in the non-aqueous electrolyte can effectively improve the high-temperature cycle capacity retention rate, high-temperature storage capacity retention rate, capacity recovery rate, volume expansion rate and internal resistance growth rate of the lithium-ion battery, indicating that the passivation film formed by the decomposition of the compound shown in Structural Formula 1 on the surface of the positive and negative electrodes has a high high-temperature stability, improves the performance stability of the positive and negative electrode materials in long-term cycles, and improves the cycle performance and storage performance of the lithium-ion battery at high temperatures. From the test results of Examples 1-9, it can be seen that as the content of the compound shown in Structural Formula 1 increases, the high-temperature storage performance and high-temperature cycle performance of the lithium-ion battery first increase and then decrease, especially when the content of the compound is 0.5%-5.0%, the lithium-ion battery has the best comprehensive performance, indicating that during the charge and discharge cycle of the lithium-ion battery, when the content of the compound shown in Structural Formula 1 in the electrolyte is 0.5%-5.0%, it can ensure that the formed SEI film is regular and of moderate thickness, and has better stability.
实施例4和对比例2-5对比知，相比于传统的碳酸亚乙烯酯(VC)、硫酸乙烯酯(DTD)、1，3-丙烷磺酸内酯(PS)和三(三甲基硅烷)磷酸酯(TMSP)，采用本申请提供的结构式1所示的化合物作为添加剂，能够更加明显地改善锂离子电池在高温下的存储性能，说明由结构式1所示共碳五元环状酯类化合物形成的钝化膜具有更加优异的高温稳定性，在高温条件 下不易被破坏。实施例4和实施例10对比知，辅助添加剂与结构式1所示的化合物具有协同提高电池高温存储和循环性能的作用。By comparing Example 4 with Comparative Examples 2-5, it is known that compared with traditional vinylene carbonate (VC), vinyl sulfate (DTD), 1,3-propane sultone (PS) and tris(trimethylsilyl) phosphate (TMSP), the compound shown in the structural formula 1 provided in the present application is used as an additive, which can more significantly improve the storage performance of lithium-ion batteries at high temperatures, indicating that the passivation film formed by the co-carbon five-membered cyclic ester compound shown in the structural formula 1 has better high-temperature stability and is more stable under high temperature conditions. Comparison between Example 4 and Example 10 shows that the auxiliary additive and the compound shown in Structural Formula 1 have the effect of synergistically improving the high temperature storage and cycle performance of the battery.
实施例1-9和对比例6-7对比知，当结构式1所示的化合物含量过低时，在正负极表面难以形成完整的钝化膜，对于锂离子电池性能的提升不明显；当结构式1所示的化合物含量高于10％时，电池的高温存储性能降低，电池内阻增加率提高、厚度膨胀率增大，高温循环性能差，猜测是含量过高的结构式1所示的化合物形成的SEI膜的厚度较大，增加正负极的截面阻抗，而劣化电池的高温性能。By comparing Examples 1-9 and Comparative Examples 6-7, it is known that when the content of the compound shown in Structural Formula 1 is too low, it is difficult to form a complete passivation film on the surface of the positive and negative electrodes, and the improvement in the performance of the lithium-ion battery is not obvious; when the content of the compound shown in Structural Formula 1 is higher than 10%, the high-temperature storage performance of the battery is reduced, the increase rate of the battery internal resistance is increased, the thickness expansion rate is increased, and the high-temperature cycle performance is poor. It is speculated that the SEI film formed by the compound shown in Structural Formula 1 with an excessively high content is thicker, which increases the cross-sectional impedance of the positive and negative electrodes and deteriorates the high-temperature performance of the battery.
由实施例4、10～13的测试结果可以看出，采用碳酸亚乙烯酯(VC)、硫酸乙烯酯(DTD)、1,3丙烷磺酸内酯(PS)或三(三甲基硅烷)磷酸酯(TMSP)与结构式1所示的化合物进行配合，能够更加明显地提高锂离子电池的高温循环性能，推测是由于VC、DTD、PS、TMSP与结构式1所示的化合物共同参与正负极表面钝化膜的形成，利于提高钝化膜的质量。It can be seen from the test results of Examples 4 and 10 to 13 that the use of vinylene carbonate (VC), vinyl sulfate (DTD), 1,3-propane sultone (PS) or tris(trimethylsilyl) phosphate (TMSP) in combination with the compound shown in Structural Formula 1 can more significantly improve the high temperature cycle performance of the lithium ion battery. It is speculated that VC, DTD, PS, TMSP and the compound shown in Structural Formula 1 jointly participate in the formation of the passivation film on the surface of the positive and negative electrodes, which is beneficial to improving the quality of the passivation film.
实施例4、14-18电解液参数及电性能数据见表3。The electrolyte parameters and electrical performance data of Examples 4 and 14-18 are shown in Table 3.
表3
table 3
由实施例4、14-18的测试结果可以看出，采用不同结构式1所示的化合物作为非水电解液的添加剂时，对于锂离子电池的高温存储性能和高温循环性能均有一定程度的提高。It can be seen from the test results of Examples 4 and 14-18 that when the compounds represented by different structural formulas 1 are used as additives for non-aqueous electrolytes, the high-temperature storage performance and high-temperature cycle performance of lithium-ion batteries are improved to a certain extent.
实施例19Embodiment 19
实施例19以制备钠离子电池为例对本发明进行说明，包括以下操作步骤：Example 19 The present invention is described by taking the preparation of a sodium ion battery as an example, comprising the following steps:
1)非水电解液的制备：1) Preparation of non-aqueous electrolyte:
将碳酸乙烯酯(EC)、碳酸二乙酯(DEC)和碳酸甲乙酯(EMC)按质量比为EC:DEC:EMC＝1:1:1进行混合，然后加入六氟磷酸钠(NaPF6)至摩尔浓度为1mol/L，加入添加剂，以所述非水电解液的总重量为100％计，非水电解液中结构式1所示的化合物含量如表4所示。Ethylene carbonate (EC), diethyl carbonate (DEC) and ethyl methyl carbonate (EMC) were mixed at a mass ratio of EC:DEC:EMC=1:1:1, and then sodium hexafluorophosphate (NaPF 6 ) was added to a molar concentration of 1 mol/L, and additives were added. Based on the total weight of the non-aqueous electrolyte being 100%, the content of the compound represented by structural formula 1 in the non-aqueous electrolyte was as shown in Table 4.
2)正极片的制备：2) Preparation of positive electrode sheet:
按94:3:3的质量比混合正极活性材料Na3V2(PO4)3、导电碳黑Super-P和粘结剂聚偏二氟乙烯(PVDF)，然后将它们分散在N-甲基-2-吡咯烷酮(NMP)中，得到正极浆料。将浆料均匀涂布在铝箔的两面上，经过烘干、压延和真空干燥，并用超声波焊机焊上铝或镍制引出 线后得到正极片，其厚度在80-200μm之间。The positive electrode active material Na 3 V 2 (PO 4 ) 3 , the conductive carbon black Super-P and the binder polyvinylidene fluoride (PVDF) were mixed in a mass ratio of 94:3:3, and then dispersed in N-methyl-2-pyrrolidone (NMP) to obtain a positive electrode slurry. The slurry was evenly coated on both sides of the aluminum foil, dried, rolled and vacuum dried, and welded with aluminum or nickel lead wires using an ultrasonic welder. After the wire is cut, the positive electrode sheet is obtained, and its thickness is between 80-200μm.
3)负极片的制备：3) Preparation of negative electrode sheet:
按97:1:1:1的质量比混合负极活性材料球形硬碳、导电碳黑Super-P、粘结剂丁苯橡胶(SBR)和羧甲基纤维素(CMC)，然后将它们分散在去离子水中，得到负极浆料。将浆料涂布在铝箔的两面上，经过烘干、压延和真空干燥，并用超声波焊机焊上铝或镍制引出线后得到负极片，其厚度在80-300μm之间。The negative electrode active material spherical hard carbon, conductive carbon black Super-P, binder styrene butadiene rubber (SBR) and carboxymethyl cellulose (CMC) are mixed in a mass ratio of 97:1:1:1, and then dispersed in deionized water to obtain a negative electrode slurry. The slurry is coated on both sides of the aluminum foil, dried, rolled and vacuum dried, and welded with aluminum or nickel lead wires using an ultrasonic welder to obtain a negative electrode sheet with a thickness between 80-300μm.
4)将正极片、隔膜、负极片按顺序叠好，经铝塑膜封装、再烘烤、注液、静置、化成、夹具整形、二封、容量测试，完成钠离子电池的制备。4) The positive electrode sheet, the separator, and the negative electrode sheet are stacked in order, and the preparation of the sodium ion battery is completed by aluminum-plastic film packaging, re-baking, liquid injection, static placement, formation, fixture shaping, secondary sealing, and capacity testing.
实施例19～36Examples 19 to 36
实施例19～36用于说明本发明公开的钠离子电池及其制备方法，包括实施例18中大部分操作步骤，其不同之处在于：Examples 19 to 36 are used to illustrate the sodium ion battery and the preparation method thereof disclosed in the present invention, and include most of the operation steps in Example 18, except that:
采用表4和表5中实施例19～31所示的添加剂及含量。The additives and contents shown in Examples 19 to 31 in Tables 4 and 5 were used.
对比例8-14Comparative Examples 8-14
对比例8～14用于对比说明本发明公开的钠离子电池及其制备方法，包括实施例19中大部分操作步骤，其不同之处在于：Comparative Examples 8 to 14 are used to compare and illustrate the sodium ion battery and the preparation method thereof disclosed in the present invention, and include most of the operating steps in Example 19, except that:
采用表4中对比例8～14所示的添加剂及含量。The additives and contents shown in Comparative Examples 8 to 14 in Table 4 were used.
性能测试Performance Testing
对上述制备得到的钠离子电池进行如下性能测试：The sodium ion battery prepared above was subjected to the following performance tests:
(1)高温存储性能测试(1) High temperature storage performance test
将化成后的钠离子电池在常温下以0.5C的电流恒流充电至4.0V，再恒压充电至电流下降至0.03C，然后以1C的电流恒流放电至1.5V，测量电池初始放电容量C1、初始电池体积V＇1及初始阻抗F＇1，然后充至满电在60℃环境中储存30天后，以1C放电至3V，测量电池的保持容量C2、恢复容量C3、储存后阻抗F＇2及储存后电池体积V＇2。计算公式如下：The formed sodium ion battery was charged to 4.0V at a constant current of 0.5C at room temperature, then charged at a constant voltage until the current dropped to 0.03C, and then discharged to 1.5V at a constant current of 1C, and the initial discharge capacity C1, initial battery volume V'1 and initial impedance F'1 of the battery were measured. After being fully charged and stored in an environment of 60℃ for 30 days, it was discharged to 3V at 1C, and the battery retention capacity C2, recovery capacity C3, impedance F'2 after storage and battery volume V'2 after storage were measured. The calculation formula is as follows:
电池容量保持率(％)＝保持容量C2/初始容量C1×100％；Battery capacity retention rate (%) = retention capacity C2/initial capacity C1×100%;
电池容量恢复率(％)＝恢复容量C3/初始容量C1×100％；Battery capacity recovery rate (%) = recovery capacity C3/initial capacity C1×100%;
体积膨胀率(％)＝(储存后电池体积V＇2-初始电池体积V＇1)/初始电池体积V＇1×100％；Volume expansion rate (%) = (battery volume after storage V'2 - initial battery volume V'1 ) / initial battery volume V'1 × 100%;
内阻增长率(％)＝(储存后阻抗F＇2-初始阻抗F＇1)/初始阻抗F＇1×100％。Internal resistance growth rate (%) = (impedance after storage F' 2 - initial impedance F' 1 )/initial impedance F' 1 × 100%.
(2)高温循环性能测试(2) High temperature cycle performance test
将化成后的电池在45℃静置2h，以0.5C的倍率恒流充电至4.0V，再恒压充电至电流为0.03C，然后以1C的电流恒流放电至1.5V，循环200周。The formed battery was placed at 45°C for 2h, charged at a constant current of 0.5C to 4.0V, then charged at a constant voltage to a current of 0.03C, and then discharged at a constant current of 1C to 1.5V, for 200 cycles.
测量电池初始放电容量C4、循环200周的放电容量C5，电池库伦效率E。The battery’s initial discharge capacity C4, discharge capacity C5 after 200 cycles, and battery coulombic efficiency E were measured.
电池容量保持率(％)＝放电容量C5/初始容量C4×100％。Battery capacity retention rate (%) = discharge capacity C5/initial capacity C4×100%.
实施例19～31和对比例8-14电解液参数及电性能数据见见表4。 The electrolyte parameters and electrical performance data of Examples 19 to 31 and Comparative Examples 8 to 14 are shown in Table 4.
表4
Table 4
从实施例19～27和对比例8的测试结果可以看出，与结构式1所示化合物在锂离子电池中所起的作用相似，在钠离子电池的非水电解液中加入结构式1所示化合物，同样能够起到改善钠离子电池的高温循环容量保持率、高温存储的容量保持率、容量恢复率、体积膨胀率和阻抗增长率的作用，说明由结构式1所示的化合物在正负极表面分解形成的钝化膜具有较高的高温稳定性，提升了正负极材料在长期循环中的性能稳定性，提高了钠离子电池在高温下的循环性能和存储性能。从实施例19～27的测试结果可知，随着结构式1所示的化合物的含量提升，钠离子电池的高温存储性能和高温循环性能先提升后降低，尤其是，当化合物的含量为0.5％～5％时，钠离子电池具有最佳的综合性能，说明钠离子电池充放电循环的过程中，电解液中结构式1所示的化合物的含量为0.5％～5％时，能够保证所形成的SEI膜规整且厚薄适中，稳定性更好。From the test results of Examples 19 to 27 and Comparative Example 8, it can be seen that, similar to the role played by the compound shown in Structural Formula 1 in lithium-ion batteries, the addition of the compound shown in Structural Formula 1 to the non-aqueous electrolyte of the sodium-ion battery can also improve the high-temperature cycle capacity retention rate, high-temperature storage capacity retention rate, capacity recovery rate, volume expansion rate and impedance growth rate of the sodium-ion battery, indicating that the passivation film formed by the decomposition of the compound shown in Structural Formula 1 on the surface of the positive and negative electrodes has a high high-temperature stability, improves the performance stability of the positive and negative electrode materials in long-term cycles, and improves the cycle performance and storage performance of the sodium-ion battery at high temperatures. From the test results of Examples 19 to 27, it can be seen that as the content of the compound shown in Structural Formula 1 increases, the high-temperature storage performance and high-temperature cycle performance of the sodium-ion battery first increase and then decrease, especially when the content of the compound is 0.5% to 5%, the sodium-ion battery has the best comprehensive performance, indicating that during the charge and discharge cycle of the sodium-ion battery, when the content of the compound shown in Structural Formula 1 in the electrolyte is 0.5% to 5%, it can ensure that the formed SEI film is regular and of moderate thickness, and has better stability.
由实施例22和对比例9～12的测试结果可以看出，相比于常规成膜添加剂及其组合，如碳酸亚乙烯酯(VC)、硫酸乙烯酯(DTD)、1,3丙烷磺酸内酯(PS)或氟代碳酸乙烯酯(FEC)，采用本申请提供的结构式1所示的化合物作为添加剂，能够更加显著地改善钠离子电池在高 温下的存储性能和循环性能，降低电池膨胀率和内阻增长率，说明相比于常规成膜添加剂，由结构式1所示化合物形成的钝化膜具有更加优异的高温稳定性。It can be seen from the test results of Example 22 and Comparative Examples 9 to 12 that, compared with conventional film-forming additives and combinations thereof, such as vinylene carbonate (VC), dithiothreitol (DTD), 1,3-propane sultone (PS) or fluoroethylene carbonate (FEC), the compound represented by the structural formula 1 provided in the present application is used as an additive, which can more significantly improve the performance of sodium ion batteries at high temperatures. The storage performance and cycle performance at room temperature are improved, and the battery expansion rate and internal resistance growth rate are reduced, indicating that compared with conventional film-forming additives, the passivation film formed by the compound shown in Structural Formula 1 has better high-temperature stability.
由实施例20、28～31的测试结果可以看出，采用碳酸亚乙烯酯(VC)、硫酸乙烯酯(DTD)、1,3丙烷磺酸内酯(PS)或氟代碳酸乙烯酯(FEC)与结构式1所示的化合物进行配合，能够更加明显地提高钠离子电池的高温循环性能，推测是由于VC、DTD、PS或FEC与结构式1所示的化合物共同参与正负极表面钝化膜的形成，利于提高钝化膜的质量。It can be seen from the test results of Examples 20 and 28 to 31 that the use of vinylene carbonate (VC), vinyl sulfate (DTD), 1,3-propane sultone (PS) or fluoroethylene carbonate (FEC) in combination with the compound shown in Structural Formula 1 can more significantly improve the high temperature cycle performance of the sodium ion battery. It is speculated that this is because VC, DTD, PS or FEC and the compound shown in Structural Formula 1 jointly participate in the formation of the passivation film on the surface of the positive and negative electrodes, which is beneficial to improving the quality of the passivation film.
实施例22、32-36电解液参数及电性能数据见表5。The electrolyte parameters and electrical performance data of Examples 22, 32-36 are shown in Table 5.
表5
table 5
如表5所示，实施例22、32-36电解液中加入结构式1所示的化合物的种类不同，电池的高温存储性能和循环性能数据相差较小，说明电解液中加入不同结构式1所示的化合物作为添加剂时，能够在负极表面形成规整的网状结构SEI膜，即使高温条件下SEI膜也不容易破裂，提高电池的高温存储性能和高温循环性能，且具有减小电解液在负极表面的分解，减少气体生成，降低高温存储厚度膨胀率，电池具有较好的高温适应性。As shown in Table 5, different types of compounds represented by structural formula 1 are added to the electrolytes of Examples 22 and 32-36, and the high-temperature storage performance and cycle performance data of the batteries are slightly different, indicating that when different compounds represented by structural formula 1 are added to the electrolyte as additives, a regular network structure SEI film can be formed on the surface of the negative electrode, and the SEI film is not easy to rupture even under high temperature conditions, thereby improving the high-temperature storage performance and high-temperature cycle performance of the battery, and reducing the decomposition of the electrolyte on the negative electrode surface, reducing gas generation, and reducing the high-temperature storage thickness expansion rate, and the battery has good high-temperature adaptability.
以上所述仅为本发明的较佳实施例而已，并不用以限制本发明，凡在本发明的精神和原则之内所作的任何修改、等同替换和改进等，均应包含在本发明的保护范围之内。 The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims (15)

  1. 一种非水电解液，其特征在于，包括电解质盐、非水有机溶剂和添加剂，所述添加剂包括结构式1所示的化合物：
    A non-aqueous electrolyte, characterized in that it comprises an electrolyte salt, a non-aqueous organic solvent and an additive, wherein the additive comprises a compound represented by structural formula 1:
    其中，R1、R2各自独立地选自氢原子、卤素原子、C1-C5的烃基或C1-C5的卤代烃基。Wherein, R 1 and R 2 are each independently selected from a hydrogen atom, a halogen atom, a C1-C5 hydrocarbon group or a C1-C5 halogenated hydrocarbon group.
  2. 根据权利要求1所述的非水电解液，其特征在于，所述结构式1所示的化合物选自以下化合物中的至少一种：
    The non-aqueous electrolyte according to claim 1, characterized in that the compound represented by structural formula 1 is selected from at least one of the following compounds:
  3. 根据权利要求1所述的非水电解液，其特征在于，以所述非水电解液的总质量为100％计，所述结构式1所示的化合物的质量百分含量为0.05％～10％。The non-aqueous electrolyte according to claim 1, characterized in that, based on the total mass of the non-aqueous electrolyte being 100%, the mass percentage of the compound represented by structural formula 1 is 0.05% to 10%.
  4. 根据权利要求1或3所述的非水电解液，其特征在于，以所述非水电解液的总质量为100％计，所述结构式1所示的化合物的质量百分含量为0.1％～5％。The non-aqueous electrolyte according to claim 1 or 3, characterized in that, based on the total mass of the non-aqueous electrolyte being 100%, the mass percentage of the compound represented by structural formula 1 is 0.1% to 5%.
  5. 根据权利要求1所述的非水电解液，其特征在于，所述非水电解液中电解质盐的浓度 为0.1mol/L～8mol/L。The non-aqueous electrolyte according to claim 1, characterized in that the concentration of the electrolyte salt in the non-aqueous electrolyte is 0.1mol/L～8mol/L.
  6. 根据权利要求1所述的非水电解液，其特征在于，所述电解质盐选自锂盐或钠盐。The non-aqueous electrolyte according to claim 1, characterized in that the electrolyte salt is selected from a lithium salt or a sodium salt.
  7. 根据权利要求6所述的非水电解液，其特征在于，所述锂盐选自LiPF6、LiBOB、LiDFOB、LiPO2F2、LiBF4、LiSbF6、LiAsF6、LiN(SO2CF3)2、LiN(SO2C2F5)2、LiC(SO2CF3)3、LiN(SO2F)2、LiClO4、LiAlCl4、LiCF3SO3、Li2B10Cl10、LiSO3F、LiTOP(三草酸磷酸锂)、LiDODFP(二氟二草酸磷酸锂)、LiOTFP(四氟草酸磷酸锂)和低级脂肪族羧酸锂盐中的至少一种。The non-aqueous electrolyte according to claim 6, characterized in that the lithium salt is at least one selected from LiPF6 , LiBOB, LiDFOB , LiPO2F2 , LiBF4 , LiSbF6 , LiAsF6 , LiN ( SO2CF3 ) 2 , LiN ( SO2C2F5 ) 2 , LiC( SO2CF3 ) 3 , LiN(SO2F) 2 , LiClO4 , LiAlCl4 , LiCF3SO3 , Li2B10Cl10 , LiSO3F , LiTOP ( lithium trioxalate phosphate), LiDODFP ( lithium difluorodioxalate phosphate), LiOTFP (lithium tetrafluorooxalate phosphate ) and lower aliphatic carboxylic acid lithium salts.
  8. 根据权利要求6所述的非水电解液，其特征在于，所述钠盐选自NaPF6、NaClO4、NaAsF6、NaSbF6、NaPOF4、NaPO2F2、NaC4BO8、NaC2BF2O4、NaODFB、NaN(SO2C2F5)2、NaN(SO2CF3)(SO2C4F9)2、NaC(SO2CF3)和Na(C2F5)PF3中的至少一种。The non-aqueous electrolyte according to claim 6, characterized in that the sodium salt is at least one selected from the group consisting of NaPF6 , NaClO4 , NaAsF6 , NaSbF6 , NaPOF4 , NaPO2F2 , NaC4BO8 , NaC2BF2O4 , NaODFB, NaN ( SO2C2F5) 2 , NaN ( SO2CF3 ) ( SO2C4F9 ) 2 , NaC( SO2CF3 ) and Na( C2F5 ) PF3 .
  9. 根据权利要求1所述的非水电解液，其特征在于，所述非水电解液还包括辅助添加剂，所述辅助添加剂包括环状硫酸酯类化合物、磺酸内酯类化合物、环状碳酸酯类化合物、磷酸酯类化合物、硼酸酯类化合物和腈类化合物中的至少一种。The non-aqueous electrolyte according to claim 1 is characterized in that the non-aqueous electrolyte also includes an auxiliary additive, and the auxiliary additive includes at least one of a cyclic sulfate ester compound, a sultone compound, a cyclic carbonate compound, a phosphate ester compound, a borate ester compound and a nitrile compound.
  10. 根据权利要求9所述的非水电解液，其特征在于，以所述非水电解液的总质量为100％计，所述辅助添加剂的添加量为0.01％～30％。The non-aqueous electrolyte according to claim 9, characterized in that, based on the total mass of the non-aqueous electrolyte being 100%, the amount of the auxiliary additive added is 0.01% to 30%.
  11. 根据权利要求10所述的非水电解液，其特征在于，以所述非水电解液的总质量为100％计，所述辅助添加剂的添加量为0.1％～5％。The non-aqueous electrolyte according to claim 10, characterized in that, based on the total mass of the non-aqueous electrolyte being 100%, the amount of the auxiliary additive added is 0.1% to 5%.
  12. 根据权利要求9所述的非水电解液，其特征在于，所述环状硫酸酯类化合物选自硫酸乙烯酯、硫酸丙烯酯、 或甲基硫酸乙烯酯中的至少一种；The non-aqueous electrolyte according to claim 9, characterized in that the cyclic sulfate ester compound is selected from vinyl sulfate, propylene sulfate, or at least one of methyl vinyl sulfate;
    所述磺酸内酯类化合物选自1,3-丙烷磺酸内酯、1,4-丁烷磺酸内酯或1,3-丙烯磺酸内酯、中的至少一种；The sultone compound is selected from 1,3-propane sultone, 1,4-butane sultone or 1,3-propylene sultone, At least one of;
    所述环状碳酸酯类化合物选自碳酸亚乙烯酯、碳酸乙烯亚乙酯、亚甲基碳酸乙烯酯、氟代碳酸乙烯酯、三氟甲基碳酸乙烯酯、双氟代碳酸乙烯酯或结构式2所示化合物中的至少一种；
    The cyclic carbonate compound is selected from at least one of vinylene carbonate, ethylene carbonate, methylene carbonate, fluoroethylene carbonate, trifluoromethylethylene carbonate, bisfluoroethylene carbonate or the compound shown in structural formula 2;
    所述结构式2中，R21、R22、R23、R24、R25、R26各自独立地选自氢原子、卤素原子、C1-C5基团中的一种；In the structural formula 2, R 21 , R 22 , R 23 , R 24 , R 25 , and R 26 are each independently selected from a hydrogen atom, a halogen atom, and a C1-C5 group;
    所述磷酸酯类化合物选自三(三甲基硅烷)磷酸酯、三(三甲基硅烷)亚磷酸酯或结构式3所示化合物中的至少一种：
    The phosphate compound is selected from at least one of tris(trimethylsilyl)phosphate, tris(trimethylsilyl)phosphite or the compound shown in structural formula 3:
    所述结构式3中，R31、R32、R33各自独立的选自C1-C5的饱和烃基、不饱和烃基、卤代烃基、-Si(CmH2m+1)3，m为1～3的自然数，且R31、R32、R33中至少有一个为不饱和烃基；In the structural formula 3, R 31 , R 32 , and R 33 are each independently selected from a C1-C5 saturated hydrocarbon group, an unsaturated hydrocarbon group, a halogenated hydrocarbon group, and -Si(C m H 2m+1 ) 3 , m is a natural number of 1 to 3, and at least one of R 31 , R 32 , and R 33 is an unsaturated hydrocarbon group;
    所述硼酸酯类化合物选自三(三甲基硅烷)硼酸酯和三(三乙基硅烷)硼酸酯中的至少一种；The borate compound is selected from at least one of tris(trimethylsilyl)borate and tris(triethylsilyl)borate;
    所述腈类化合物包括丁二腈、戊二腈、乙二醇双(丙腈)醚、己烷三腈、己二腈、庚二腈、辛二腈、壬二腈、癸二腈中的至少一种。The nitrile compound includes at least one of succinonitrile, glutaronitrile, ethylene glycol bis(propionitrile) ether, hexanetrinitrile, adiponitrile, pimelonitrile, suberonitrile, azelaic acid dinitrile and sebaconitrile.
  13. 根据权利要求1所述的非水电解液，其特征在于，所述非水有机溶剂包括醚类溶剂、腈类溶剂、碳酸酯类溶剂、羧酸酯类溶剂和砜类溶剂中的至少一种。The non-aqueous electrolyte according to claim 1, characterized in that the non-aqueous organic solvent comprises at least one of an ether solvent, a nitrile solvent, a carbonate solvent, a carboxylate solvent and a sulfone solvent.
  14. 一种二次电池，其特征在于，包括正极、负极及权利要求1-13任意一项所述的非水电解液。A secondary battery, characterized in that it comprises a positive electrode, a negative electrode and the non-aqueous electrolyte according to any one of claims 1 to 13.
  15. 根据权利要求14所述的二次电池，其特征在于，所述二次电池为锂金属电池、锂离子电池、锂硫电池或钠离子电池。 The secondary battery according to claim 14 is characterized in that the secondary battery is a lithium metal battery, a lithium ion battery, a lithium sulfur battery or a sodium ion battery.
PCT/CN2023/113029 2022-10-09 2023-08-15 Non-aqueous electrolyte and secondary battery WO2024078116A1 (en)

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