CN110994023A - Lithium ion battery safety electrolyte, preparation method and application thereof, and lithium ion battery - Google Patents

Lithium ion battery safety electrolyte, preparation method and application thereof, and lithium ion battery Download PDF

Info

Publication number
CN110994023A
CN110994023A CN201911200909.0A CN201911200909A CN110994023A CN 110994023 A CN110994023 A CN 110994023A CN 201911200909 A CN201911200909 A CN 201911200909A CN 110994023 A CN110994023 A CN 110994023A
Authority
CN
China
Prior art keywords
electrolyte
lithium
solvent
phosphate
lithium ion
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN201911200909.0A
Other languages
Chinese (zh)
Other versions
CN110994023B (en
Inventor
马佳丽
蒋贝贝
聂航
赵双琪
林定文
张文博
丁先红
舒涛
聂红明
周环波
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hubei Uee Energy Technology Co ltd
Original Assignee
Hubei Uee Energy Technology Co ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hubei Uee Energy Technology Co ltd filed Critical Hubei Uee Energy Technology Co ltd
Priority to CN201911200909.0A priority Critical patent/CN110994023B/en
Publication of CN110994023A publication Critical patent/CN110994023A/en
Application granted granted Critical
Publication of CN110994023B publication Critical patent/CN110994023B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
    • H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
    • H01M10/0566—Liquid materials
    • H01M10/0567—Liquid materials characterised by the additives
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
    • H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
    • H01M10/0566—Liquid materials
    • H01M10/0569—Liquid materials characterised by the solvents
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2300/00—Electrolytes
    • H01M2300/0017—Non-aqueous electrolytes
    • H01M2300/0025—Organic electrolyte
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2300/00—Electrolytes
    • H01M2300/0017—Non-aqueous electrolytes
    • H01M2300/0025—Organic electrolyte
    • H01M2300/0028—Organic electrolyte characterised by the solvent
    • H01M2300/0037—Mixture of solvents
    • H01M2300/004—Three solvents
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2300/00—Electrolytes
    • H01M2300/0017—Non-aqueous electrolytes
    • H01M2300/0025—Organic electrolyte
    • H01M2300/0028—Organic electrolyte characterised by the solvent
    • H01M2300/0037—Mixture of solvents
    • H01M2300/0042—Four or more solvents
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Inorganic Chemistry (AREA)
  • Materials Engineering (AREA)
  • Secondary Cells (AREA)

Abstract

The invention belongs to the field of lithium ion batteries, and particularly relates to a lithium ion battery safety electrolyte, a preparation method and application thereof, and a lithium ion battery. The safe electrolyte of the lithium ion battery comprises an electrolyte, an electrolyte additive, a solvent, a cosolvent and a solvent additive. The preparation method comprises the following steps: 1) under the condition of vacuum or protective atmosphere, mixing a solvent cosolvent, a solvent additive and a drying agent, uniformly stirring, and filtering out precipitates or solids; 2) and adding the electrolyte and the electrolyte additive which are dried to constant weight into the mixed solvent under the conditions of vacuum or protective atmosphere and 60-85 ℃, and uniformly stirring under the conditions of vacuum or protective atmosphere to obtain the safe electrolyte of the lithium ion battery. The battery manufactured by the electrolyte can normally work at a wider temperature range of-50-80 ℃, the charge-discharge efficiency, the heavy-current discharge effect and the discharge capacity of the lithium ion battery are obviously improved, and the charge-discharge cycle service life is obviously prolonged.

Description

Lithium ion battery safety electrolyte, preparation method and application thereof, and lithium ion battery
Technical Field
The invention belongs to the field of lithium ion batteries, and particularly relates to a lithium ion battery safety electrolyte, a preparation method and application thereof, and a lithium ion battery.
Background
In the twenty-first century, particularly in recent years, the electrolytes used in lithium ion batteries manufactured by the prior industrial technologies are mainly Ethylene Carbonate (EC), Ethyl Methyl Carbonate (EMC), diethyl carbonate (DEC), dimethyl carbonate (DMC), Propylene Carbonate (PC), and the like, wherein the volume ratio of two, three and the like of organic substances is a mixed solvent, and LiPF (lithium ion plasma) is used as a mixed solvent6、LiClO4、LiBF4And the (lithium salt) electrolyte is a lithium ion battery electrolyte solution with solute concentration of 0.1-2.0M (mol/L). The known electrolyte has great influence on the performance of the lithium ion battery, because the components and the concentration of the electrolyte are closely related to the conductivity and the electrode reaction of the electrolyte, the conductivity of the electrolyte and the reversibility of the electrode reaction directly influence the discharge capacity of the lithium ion battery, and the stability of the electrolyte directly acts on the electrolyte and can directly influence the safety performance of the lithium ion battery, particularly the high-rate high-capacity lithium ion power battery. The lithium ion battery electrolyte is of great importance to the specific capacity, working temperature range, charge-discharge cycle efficiency and safety performance of the lithium ion battery. EC. Solvents such as DEC, DMC, EMC and the like are mainly used for lithium ion secondary batteries. Trialkyl(s)The aryl silane is added into the common electrolyte of the lithium ion battery, so that the safety performance of the electrolyte can be improved, and the battery does not smoke, ignite or explode when overcharged; crown ether and a cryptate compound can form a coated chelate with lithium ions, so that the solubility of lithium salt in an organic solvent can be improved, the effective separation of anions and cations and the separation of the lithium ions and the solvent are realized, and the conductivity of the electrolyte is improved; some fluorinated chain ethers, e.g. C4F9OCH3The organic electrolyte is recommended to be used for secondary lithium ion battery electrolyte, and can improve the thermal stability of the organic electrolyte; the micro Hexamethyldisilazane (HMDS) can inhibit LiPF of the lithium ion battery electrolyte in the storage process6The hydrolysis and pyrolysis of the electrolyte reduce the content of water and hydrogen fluoride in the electrolyte, and improve the storage stability and the thermal stability of the lithium ion battery electrolyte.
In the prior art, lithium salt is taken as an electrolyte, common organic solvents are taken as solutions, certain functional additives and the like, and the lithium ion battery manufactured by the manufactured lithium ion battery electrolyte obviously has the following defects: firstly, the high-temperature or low-temperature working performance is poor, and even the lithium ion battery can not normally work at the higher temperature of more than 45 ℃ or the lower temperature of less than-30 ℃ completely or the working electrochemical performance is poor; secondly, the lithium ion power battery for the lithium ion power battery car has poor high-rate (quick discharge) and large-current charging and discharging effects, influences the normal work of the lithium ion battery pack, and severely limits the application range of the lithium ion power battery; thirdly, the lithium ion battery for the reserve battery or the emergency power supply has poor overcharge resistance, the cycle service life, the charge and discharge efficiency and the discharge capacity of the lithium ion battery are influenced, the attenuation of the storage capacity is serious, and the capacity and the cycle service life of the lithium ion battery are further influenced; fourthly, the safety performance of the battery is poor, and certain potential safety hazards exist in the normal charging and discharging, formation and grading processes; fifthly, solvents used in the conventional electrolyte, such as furan, pyridine, acetone and the like, have high toxicity, and cause pollution to a certain extent in the production and use of lithium ion batteries and the process of waste batteries. Although the various practical defects or deficiencies of the lithium ion battery are not caused by the existing electrolyte formula used for producing the lithium ion battery, all the deficiencies are more or less directly related to the physical and chemical properties of the electrolyte, such as conductivity, physical and chemical compatibility of the electrolyte and electrodes or substances, and even charge and discharge properties of the electrodes, cycle life and safety, for example, explosion and combustion of the battery are mainly caused by a large amount of gas and combustion heat generated by solvent combustion of the electrolyte. Obviously, the electrolyte is a crucial factor for the overall electrochemical performance and safety performance of lithium ion batteries.
Disclosure of Invention
The invention aims to solve the defects in the prior art and provides a lithium ion battery safety electrolyte, a preparation method and application thereof and a lithium ion battery. The lithium ion battery manufactured by the electrolyte can normally work under the conditions of a wider temperature range of minus 50-80 ℃ and a more extreme working environment, the charge-discharge efficiency, the heavy current discharge effect and the discharge capacity of the lithium ion battery are obviously improved, the charge-discharge cycle service life of the lithium ion battery is obviously prolonged, the comprehensive electrochemical performance of the lithium ion battery is obviously improved, particularly the safety performance of a power battery is obviously improved, the lithium ion battery can normally work at high temperature (the test environment is stable in the range of 65-80 ℃), the lithium ion battery can also show higher safety at ultrahigh temperature (such as boiling water), and the lithium ion battery is not easy to explode.
The invention aims to provide a safe electrolyte which is suitable for manufacturing a lithium ion power battery with high capacity and high multiplying power charging and discharging, improves the safety and reliability of a vehicle battery, and fundamentally improves the safety defects or shortcomings of combustion and explosion caused by the factors of the lithium ion battery.
The technical scheme provided by the invention is as follows:
a safe electrolyte of a lithium ion battery comprises an electrolyte, an electrolyte additive, a solvent, a cosolvent and a solvent additive:
the electrolyte is lithium hexafluorophosphate (LiPF) with a molar ratio of 0.1-0.5: 0.05-0.1: 0.01-0.056) Lithium tetrafluoroborate (LiBF)4) Lithium acetate (LiAc) and lithium metaphosphate (LiPO)3) A mixture of (a);
the electrolyte additive is in a molar ratio of 0.9-1.1: 0.9-1.1: 0.9-1.1.1 of lithium perfluorobutylsulfonate (LFS), lithium bis (perfluoro-1-butyryl) imide (BFI), and lithium phosphate (Li)3PO4) Or lithium metasilicate (Li)2SiO3) Any two or three or four of the above components, wherein the molar percentage of the electrolyte additive to the electrolyte is 1.0-3.5%;
the solvent is a mixture of any three or four or five of tributyl phosphate (TBP), tripentyl phosphate (TPP), trioctyl phosphate (TOP), dimethyl carbonate (DMC) or diethyl carbonate (DEC) in a volume ratio of 0.9-1.1: 0.9-1.1;
the cosolvent is a mixture of any two or three or four of methyl ethyl carbonate (EMC), Ethylene Carbonate (EC), Propylene Carbonate (PC), Butylene Carbonate (BC), ethylene glycol Diethyl Ester (DEG) or 2, 4-butane sultone (BAL) in a volume ratio of 0.9-1.1: 0.9-1.1, and the volume percentage of the cosolvent to the solvent is 6.5-15.5%;
the solvent additive is a mixture of any two of trimethyl phosphate (TMP), triethyl phosphate (TEP), Triphenyl Phosphate (TPE), diisoamyl phosphate (DPP) or Ethyl Ethanethiosulfonate (EES) in a volume ratio of 0.9-1.1: 0.9-1.1, and the volume ratio of the solvent additive to the solvent is 1.0-3.5%;
in the safe electrolyte of the lithium ion battery, the total molar concentration of the electrolyte and the electrolyte additive is 0.2-1.25M.
The lithium ion battery safe electrolyte provided by the technical scheme uses the multi-component composite solvent, the electrolyte additive, the solvent, the auxiliary agent, the additive and the like which can simultaneously improve the high-low temperature and safety performance of the cathode graphite active material and the electrolyte, such as pure lithium cobaltate, lithium nickel cobaltate, lithium manganese nickelate, lithium manganese cobaltate, ternary material, lithium iron vanadate, lithium iron phosphate and the like, so that the lithium ion battery can obtain the following beneficial effects:
1) the solvent and the cosolvent of the electrolyte prepared by the invention can be well compatible and wettable with the positive active substance and the negative active substance, so that the electrochemical utilization efficiency of the active substances is greatly improved; the maximum active utilization rate is 98.9%, and the maximum active utilization rate of the comparative example is only 95.1% (see the examples and the table 1 for details);
2) the solvent and the cosolvent of the electrolyte prepared by the invention can be well compatible and wettable with the positive active substance and the negative active substance, so that the electrochemical activity of the active substances is improved, the optimal electrochemical performance can be achieved in less formation charge-discharge cycles, and the first discharge capacity and efficiency are high; the service efficiency of the lithium ion battery can be effectively improved, and the production cycle of the battery is shortened;
3) because the solvent used by the electrolyte has better compatibility with the positive and negative active substances, the diaphragm, even the conductive agent and the like, the use of the electrolyte can effectively improve the comprehensive electrochemical performance of the positive and negative active substances of the lithium ion battery and the electrical performance of the battery, thereby effectively improving the first discharge capacity, the charge-discharge efficiency and the charge-discharge cycle capacity retention rate of the battery;
4) due to the synergistic use of the electrolyte and the electrolyte additive in the electrolyte, the crystal morphology, the change of the crystal structure, the falling-off and the like of the positive active material and the negative active material in the electrode charging and discharging process are reduced, so that the large-current charging and discharging effect of the electrode and the discharge capacity of the electrode and the battery are obviously improved (see embodiment 4 and attached figure 7 for details);
5) due to the use of the electrolyte and the additive of the electrolyte, particularly the use of the cosolvent and the solvent additive, the working temperature range of the lithium ion battery is effectively improved, the battery can effectively work within the temperature range of-50-80 ℃, the first discharge capacity under the condition of-50-80 ℃ reaches more than 85 percent of the theoretical value of the designed capacity and reaches 98.9 percent of the maximum theoretical value of the designed capacity (see table 1, various embodiments and drawings for details), and obviously, the application of the technology greatly improves the working temperature range of the battery and the working efficiency of the battery (see table 1, various embodiments and drawings for details);
6) the electrolyte provided by the invention can effectively prolong the cycle service life of the lithium ion battery, and compared with the prior art, the cycle service life of the lithium ion battery manufactured by the invention is prolonged, the 2C multiplying power can reach 2166 weeks of charge-discharge cycle at most, and the cycle of 1128 weeks at most in the comparative example is prolonged by 92% of weeks (see example 4 and comparative example 6 for details);
7) the electrolyte solvent provided by the invention has good flame retardant property, and the cosolvent and the solvent additive have good compatibility and stability to the electrolyte, so that the manufactured lithium ion power battery has good overcharge resistance, the battery with the over-charge capacity exceeding 80% of the designed capacity in the over-charge experimental process has no obvious phenomena of safety accidents such as gas expansion, abnormal high temperature, combustion, explosion and the like, and the safety performance is good (see table 1 for details).
Specifically, the electrolyte additive is a mixture of any two or three or four of lithium perfluorobutylsulfonate, lithium bis (perfluoro-1-butyryl) imide, lithium phosphate or lithium metasilicate which are mixed in an equimolar ratio, and the molar percentage of the electrolyte additive to the electrolyte is 1.0-3.5%.
Specifically, the solvent is a mixture of any three or four or five of tributyl phosphate, tripentyl phosphate, trioctyl phosphate and dimethyl carbonate) or diethyl carbonate which are mixed in equal volume ratio.
Specifically, the cosolvent is a mixture of any two or three or four of methyl ethyl carbonate, ethylene carbonate propylene carbonate, butylene carbonate, ethylene glycol diethyl ester or 2, 4-butane sultone which are mixed in an equal volume ratio, and the volume percentage of the cosolvent to the solvent is 6.5-15.5%.
Specifically, the solvent additive is a mixture of any two of trimethyl phosphate, triethyl phosphate, triphenyl phosphate, diisoamyl phosphate or ethyl ethanethiosulfonate which are mixed in an equal volume ratio, and the volume ratio of the solvent additive to the solvent is 1.0-3.5%.
The invention also provides a preparation method of the lithium ion battery safety electrolyte, which comprises the following steps:
1) under the condition of vacuum or protective atmosphere, mixing a solvent cosolvent, a solvent additive and a drying agent, uniformly stirring, and filtering out precipitates or solids to obtain a mixed solvent;
2) adding electrolyte and electrolyte additive which are dried to constant weight into the mixed solvent obtained in the step 1) under the condition of vacuum or protective atmosphere at 60-85 ℃, and uniformly stirring under the condition of vacuum or protective atmosphere to prepare the safe electrolyte of the lithium ion battery;
wherein:
the electrolyte is a mixture of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium acetate and lithium metaphosphate, wherein the molar ratio of the lithium hexafluorophosphate, the lithium tetrafluoroborate, the lithium acetate and the lithium metaphosphate is 0.1-0.5: 0.05-0.1: 0.05-0.05;
the electrolyte additive is a mixture of any two or three or four of perfluorobutyl lithium sulfonate, bis (perfluoro-1-butyryl) imide lithium, lithium phosphate or lithium metasilicate in a molar ratio of 0.9-1.1: 0.9-1.1, and the molar percentage of the electrolyte additive to the electrolyte is 1.0-3.5%;
the solvent is a mixture of any three or four or five of tributyl phosphate, tripentyl phosphate, trioctyl phosphate, dimethyl carbonate or diethyl carbonate in a volume ratio of 0.9-1.1: 0.9-1.1;
the cosolvent is a mixture of any two or three or four of methyl ethyl carbonate, ethylene carbonate, propylene carbonate, butylene carbonate, ethylene glycol diethyl ester or 2, 4-butane sultone in a volume ratio of 0.9-1.1: 0.9-1.1, and the volume percentage of the cosolvent to the solvent is 6.5-15.5%;
the solvent additive is a mixture of any two of trimethyl phosphate, triethyl phosphate, triphenyl phosphate, diisoamyl phosphate or ethyl ethanethiosulfonate in a volume ratio of 0.9-1.1: 0.9-1.1, and the volume ratio of the solvent additive to the solvent is 1.0-3.5%;
the drying agent is in a mass ratio of 0.9-1.1: 0.9 ℃1.1: 0.9-1.1 of Li2O、P2O5And anhydrous phosphorous acid, wherein the mass percentage of the mass of the composite drying agent to the total mass of the solvent, the cosolvent and the solvent additive is 3.5-5%;
in the safe electrolyte of the lithium ion battery, the total molar concentration of the electrolyte and the electrolyte additive is 0.2-1.25M.
Based on the technical scheme, the safe electrolyte for the lithium ion battery can be prepared. In addition, as the main raw materials used by the preparation method are common raw materials, have rich sources, low price, no toxicity or low toxicity and safety, are particularly suitable for the application in the field of lithium ion power battery production with large electrolyte consumption, can effectively improve the safety performance of the battery, and can not significantly increase the manufacturing cost of the battery and cause serious environmental pollution.
Specifically, in the step 1), the vacuum degree is 0.3-0.8 kpa; protective gas is N2Or Ar; stirring for 0.5-4 h; h in the mixed solvent2O and O2Are all less than 20 ppm.
Specifically, in the step 2), the vacuum degree in the material mixing process is 0.3-0.8 kpa; the protective gas in the material mixing process is N2Or Ar; the vacuum degree in the stirring process is 0.3-0.8 kpa; the protective gas in the stirring process is N2Or Ar; the stirring time is 0.5-4 hours.
Specifically, the electrolyte additive is a mixture of any two or three or four of lithium perfluorobutylsulfonate, lithium bis (perfluoro-1-butyryl) imide, lithium phosphate or lithium metasilicate which are mixed in an equimolar ratio, and the molar percentage of the electrolyte additive to the electrolyte is 1.0-3.5%.
Specifically, the solvent is a mixture of any three or four or five of tributyl phosphate, tripentyl phosphate, trioctyl phosphate, dimethyl carbonate or diethyl carbonate which are mixed in equal volume ratio.
Specifically, the cosolvent is a mixture of any two or three or four of methyl ethyl carbonate, ethylene carbonate, propylene carbonate, butylene carbonate, ethylene glycol diethyl ester or 2, 4-butane sultone which are mixed in an equal volume ratio, and the volume percentage of the cosolvent to the solvent is 6.5-15.5%.
Specifically, the solvent additive is a mixture of any two of trimethyl phosphate, triethyl phosphate, triphenyl phosphate, diisoamyl phosphate or ethyl ethanethiosulfonate which are mixed in an equal volume ratio, and the volume ratio of the solvent additive to the solvent is 1.0-3.5%.
Specifically, the drying agent is Li mixed by equal mass2O、P2O5And a composite desiccant of anhydrous phosphorous acid.
The invention also provides the lithium ion battery safety electrolyte prepared by the preparation method of the lithium ion battery safety electrolyte.
The invention also provides the application of the safe electrolyte of the lithium ion battery as the electrolyte of the lithium ion power battery.
The electrolyte solvent provided by the invention has good flame retardant property, and the cosolvent and the solvent additive have good compatibility and stability to the electrolyte, so that the manufactured lithium ion power battery has good overcharge resistance, the battery with the over-charge capacity exceeding 80% of the designed capacity in the over-charge experimental process has no obvious phenomena of safety accidents such as gas expansion, abnormal high temperature, combustion, explosion and the like, and the safety performance is good (see table 1 for details).
The invention also provides a lithium ion battery which comprises the lithium ion battery safety electrolyte provided by the invention.
The electrolyte provided by the invention can effectively prolong the cycle service life of the lithium ion battery, and compared with the prior art, the cycle service life of the lithium ion battery manufactured by the invention is prolonged, the 2C multiplying power can reach 2166 weeks at most, and the cycle of 1128 weeks at most in the comparative example is prolonged by 92% weeks (see example 4, comparative example 6, figure 5 and figure 6 for details).
TABLE 1 test results of the comprehensive performance of 5000mAh square battery of the present invention
Figure BDA0002295850190000081
Figure BDA0002295850190000091
Drawings
FIG. 1 is a discharge capacity curve of a lithium ion battery assembled by the safe electrolyte of example 1 of the present invention at-50 ℃ and 2C rate;
FIG. 2 shows the discharge capacity retention rate at-25 ℃ and 2C rate of a lithium ion battery assembled with the safe electrolyte of example 2 of the present invention;
FIG. 3 shows the cycle life of a lithium ion battery assembled with the safety electrolyte of example 3 of the present invention at-0 ℃ and 2C rate;
FIG. 4 shows the first discharge capacity and discharge efficiency at 25 ℃ and 2C rate of a lithium ion battery assembled by the safe electrolyte of example 4 of the present invention;
FIG. 5 is the specific discharge capacity at 50 ℃ and 2C rate of a lithium ion battery assembled with the safe electrolyte in example 4 of the present invention;
FIG. 6 is a comparison of the 0.2-5C rate cycle capacity retention rate of a lithium ion battery assembled with the safe electrolyte of example 4 of the present invention;
FIG. 7 shows the discharge capacity at 80 ℃ and 2C rate of a lithium ion battery assembled with the safe electrolyte of example 5 of the present invention;
fig. 8 shows the discharge efficiency of the lithium ion battery assembled with the safety electrolyte provided in example 5 of the present invention at 25 ℃ and 2C rate.
Description of the drawings: a: the invention is 2500mAh or 5000mAh square lithium ion battery, B: the lithium ion batteries with the same type and the same capacity are compared; the charging and discharging are completed under the conditions of 0.5, 1C, 2C or 5C multiplying power, constant-current charging and discharging, 4.2-4.35V of charging limiting voltage and 3.00V of discharging cutoff voltage.
Detailed Description
The principles and features of this invention are described below in conjunction with examples which are set forth to illustrate, but are not to be construed to limit the scope of the invention.
Example 1:
a preparation method of a lithium ion power battery safety electrolyte comprises the following steps:
first, in a vacuum of 0.3kpa or N2Or under the protection of Ar gas, mixing the mixed solvent in equal volume ratio: TBP (tributyl phosphate), TPP (tripentyl phosphate), TOP (trioctyl phosphate), and a cosolvent which is mixed by volume of 6.5 percent of the solvent and equal volume ratio: EMC (ethyl methyl carbonate), EC (ethylene carbonate) two substance mixture, solvent additive 1.0% of solvent volume mixed in equal volume ratio: uniformly mixing a mixture of TMP (trimethyl phosphate) and TEP (triethyl phosphate) to obtain a solvent mixture, and adding Li in an equal mass ratio of 3.5% of the total mass of the solvent mixture into the solvent mixture2O、P2O5Mixing with anhydrous phosphorous acid mixed desiccant, stirring for 4 hr, filtering to remove precipitate or solid to ensure H in solvent mixture2O、O2The amount of the catalyst does not exceed 20 ppm; thus obtaining the electrolyte mixed solvent.
Second, vacuum 0.3kpa or N2Or lithium hexafluorophosphate (LiPF) with the molar ratio of 0.1:0.05:0.05:0.01 respectively under the protection of Ar gas6) Lithium tetrafluoroborate (LiBF)4) Lithium acetate (LiAc) and lithium metaphosphate (LiPO)3) And adding a mixture of the four lithium salts and an electrolyte additive mixture of lithium perfluorobutylsulfonate (LFS) and lithium bis (perfluoro-1-butyryl) imide (BFI) in an equal mass ratio, wherein the molar ratio of the electrolyte additive mixture is 1.0% of the molar number of the electrolyte, into the electrolyte solvent prepared in the second step, and stirring for 0.5 hour to prepare a solution with the molar concentration of the electrolyte of 0.2M.
The safe electrolyte for the lithium ion power battery is prepared according to the method.
The prepared safe electrolyte of the lithium ion power battery is assembled into a square soft package lithium ion battery with the capacity of 5000mAh, the battery is charged and discharged under the condition of-50 ℃ and 2C multiplying power charging and discharging, the charging and discharging cycle performance, the high and low temperature performance and the like are tested, and the test result is obtained under the same condition as that of the battery used as a comparative test battery in example 6: the first charge-discharge cycle discharge capacity is 4295mAh (85.9% of the design capacity), the charge-discharge cycle charge-discharge retention rate at 818 weeks is 69.0% (assuming that the charge-discharge cycle with the capacity retention rate lower than 70% of the design capacity does not count the cycle of the service life of the battery), and the service life of the battery in the embodiment is more than 800 weeks of cycle; the first discharge capacity of the battery of the comparative example is 2545mAh (which is 50.9% of the designed capacity and the service life of the battery cannot be calculated), and the 283-week charge-discharge cycle capacity retention rate of the battery is only 39.7%; the first discharge capacity is 5188mAh, the open-circuit voltage is more than 3.85V and the internal resistance is within the range of 16.5-23.0 m omega under the condition of 2C multiplying power charge and discharge at 25 ℃, and compared with the first discharge capacity of 5036mAh, the open-circuit voltage is more than 3.82V and the internal resistance is within the range of 25.6-28.7 m omega of the battery; the actual utilization rate of the active material was 96.9% under the conditions of 25 ℃ and 5 ℃ multiplying power (see Table 1 for details) and the overcharge capacity was 100% under the conditions of 25 ℃ and the results are shown in Table 1 and FIG. 1 for details.
Example 2:
a preparation method of a lithium ion power battery safety electrolyte comprises the following steps:
first, in a vacuum of 0.4kpa or N2Or under the protection of Ar gas, mixing the mixed solvent in equal volume ratio: TBP (tributyl phosphate), TPP (tripentyl phosphate), TOP (trioctyl phosphate), DMC (dimethyl carbonate), and a cosolvent mixed at equal volume ratios of 9.0% by volume of solvent: PC (propylene carbonate), BC (butylene carbonate) and DEG (ethylene glycol diethyl ester) and solvent additive which accounts for 1.5 percent of the volume of the solvent and is mixed in equal volume ratio: uniformly mixing TPE (triphenyl phosphate) and DPP (diisoamyl phosphate) to obtain a solvent mixture, and adding Li in an equal mass ratio of 4.5% of the total mass of the solvent mixture into the solvent mixture2O、P2O5Mixing with anhydrous phosphorous acid mixed desiccant, stirring for 2 hr, filtering to remove precipitate or solid to ensure H in solvent mixture2O、O2The amount of the catalyst does not exceed 20 ppm; thus obtaining the electrolyte mixed solvent.
Second, vacuum 0.5kpa or N2Or Ar gasUnder the condition of body protection, lithium hexafluorophosphate (LiPF) with the molar ratio of 0.2:0.065:0.065:0.02 is added6) Lithium tetrafluoroborate (LiBF)4) Lithium acetate (LiAc) and lithium metaphosphate (LiPO)3) A mixture of four lithium salts, and lithium bis (perfluoro-1-butyryl) imide (BFI) and lithium phosphate (Li) in a molar ratio of 1.5 mol% based on the electrolyte3PO4) And lithium metasilicate (Li)2SiO3) And adding the electrolyte additive mixture mixed by the three lithium compounds in equal mass ratio into the electrolyte solvent prepared in the second step, and stirring for 1 hour to prepare a solution with the electrolyte molar concentration of 0.5M.
The safe electrolyte for the lithium ion power battery is prepared according to the method.
The prepared safe electrolyte of the lithium ion power battery is assembled into a square soft package lithium ion battery with the capacity of 5000mAh, the battery is charged and discharged under the condition of-25 ℃ and 2C multiplying power charging and discharging, the charging and discharging cycle performance, the high and low temperature performance and the like are tested, and the battery is used as a comparative test battery to be tested under the same conditions with the battery of the embodiment 6, and the result is as follows: the first charge-discharge cycle discharge capacity is 4955mAh (99.1% of the design capacity), the charge-discharge cycle charge-discharge retention rate is 89.9% in 1349 weeks (assuming that the charge-discharge cycle with the capacity retention rate lower than 70% of the design capacity does not count the cycle of the service life of the battery), and the service life of the battery in the embodiment is more than 1300 weeks; the first discharge capacity of the battery of the comparative example is 3685mAh (73.7% of the designed capacity and the service life is 180 weeks), and the charge-discharge cycle capacity retention rate at 425 weeks is only 58.0%; the first discharge capacity is 5164mAh, the open-circuit voltage is more than 3.85V and the internal resistance is in the range of 18.1-24.5 m omega under the condition of 2C multiplying power charge and discharge at 25 ℃, and compared with the first discharge capacity of 5036mAh, the open-circuit voltage is more than 3.82V and the internal resistance is in the range of 25.6-28.7 m omega of the battery; the overcharge 100% capacity test was carried out at 25 ℃ at 2C (see Table 1 and FIG. 2 for details).
Example 3:
a preparation method of a lithium ion power battery safety electrolyte comprises the following steps:
first, in a vacuum of 0.65kpa or N2Or under the protection of Ar gas, mixing the mixed solvent in equal volume ratio: TBP (tributyl phosphate), TPP (tripentyl phosphate), TOP (trioctyl phosphate), DMC (dimethyl carbonate), DEC (diethyl carbonate) mixtures of five substances, with 11.0% by volume of solvent mixed in equal volume of co-solvent: the solvent additive comprises a mixture of EMC (methyl ethyl carbonate), DEG (ethylene glycol diethyl ester) and 24BAL (2, 4-butane sultone), and solvent additives which account for 1.0-3.5% of the volume of the solvent and are mixed in equal volume ratio: uniformly mixing a mixture of any two of TMP (trimethyl phosphate), TEP (triethyl phosphate), TPE (triphenyl phosphate), DPP (diisoamyl phosphate) and EES (ethyl ethanethiosulfonate) to obtain a solvent mixture, and adding Li mixed with equal mass which accounts for 2.0% of the total mass of the solvent mixture into the solvent mixture2O、P2O5Mixing with anhydrous phosphorous acid mixed desiccant, stirring for 1 hr, filtering to remove precipitate or solid to ensure H in solvent mixture2O、O2The amount of the catalyst does not exceed 20 ppm; thus obtaining the electrolyte mixed solvent.
Second, vacuum 0.65kpa or N2Or lithium hexafluorophosphate (LiPF) with the molar ratio of 0.3:0.07:0.07:0.03 respectively under the protection of Ar gas6) Lithium tetrafluoroborate (LiBF)4) Lithium acetate (LiAc) and lithium metaphosphate (LiPO)3) A mixture of four lithium salts, and lithium perfluorobutylsulfonate (LFS), lithium bis (perfluoro-1-butyryl) imide (BFI), lithium phosphate (Li) in a molar ratio of 2.0% by mole of the electrolyte3PO4) And lithium metasilicate (Li)2SiO3) And adding the electrolyte additive mixture mixed by the four substances in equal mass ratio into the electrolyte solvent prepared in the second step, and stirring for 2 hours to prepare a solution with the main electrolyte mass molar concentration of 0.65M.
The safe electrolyte for the lithium ion power battery is prepared according to the method.
The prepared safe electrolyte of the lithium ion power battery is used for assembling a square soft package lithium ion battery with the capacity of 5000mAh, the battery is charged and discharged under the condition of 0 ℃ and 2C multiplying power charging and discharging, the charging and discharging cycle performance, the high and low temperature performance and the like are tested, and the test result is obtained under the same condition as that of the battery of the embodiment 6 as a comparative test battery: the first charge-discharge cycle discharge capacity is 5049mAh (100.98% of the design capacity), the charge-discharge cycle charge-discharge retention rate at 1456 weeks is 94.4% (assuming that the charge-discharge cycle charge-discharge retention rate is lower than 70% of the design capacity is not counted in the service life cycle of the battery), and the service life of the battery in the embodiment is more than 2000 weeks of cycle; the first discharge capacity of the battery of the comparative example is 4343mAh (86.8 percent of the designed capacity and the service life of the battery is 700 weeks), and the charge-discharge cycle capacity retention rate at 663 weeks is only 73.9 percent; the first discharge capacity is 5215mAh, the open-circuit voltage is more than 3.85V and the internal resistance is within the range of 20.0-22.8 m omega under the condition of 2C multiplying power charge and discharge at 25 ℃, and compared with the first discharge capacity of 5036mAh, the open-circuit voltage is more than 3.82V and the internal resistance is within the range of 25.6-28.7 m omega of the battery; the overcharge 100% capacity test was carried out at 25 ℃ under 2C (see Table 1 and FIG. 3 for details of the results).
Example 4:
a preparation method of a lithium ion power battery safety electrolyte comprises the following steps:
first, in a vacuum of 0.8kpa or N2Or under the protection of Ar gas, mixing the mixed solvent in equal volume ratio: TPP (tripentyl phosphate), TOP (trioctyl phosphate), DMC (dimethyl carbonate), DEC (diethyl carbonate), cosolvent mixed at equal volume ratio with 13.5% solvent volume: the solvent additive comprises a mixture of three lipids of EMC (ethyl methyl carbonate), EC (ethylene carbonate) and 24BAL (2, 4-butane sultone), and solvent additives which account for 1.0-3.5% of the volume of the solvent and are mixed in equal volume ratio: the mixture of TPE (triphenyl phosphate) and EES (ethyl ethanethiosulfonate) is evenly mixed to obtain a solvent mixture, and Li mixed with equal mass and the mass ratio of the Li to the solvent mixture is 5.5 percent of the total mass of the solvent mixture2O、P2O5Mixing with anhydrous phosphorous acid mixed desiccant, stirring for 0.5 hr, filtering to remove precipitate or solid to ensure H in solvent mixture2O、O2The amount of the catalyst does not exceed 20 ppm; thus obtaining the electrolyte mixed solvent.
Second, vacuum 0.8kpa or N2Or under the protection of Ar gas, the molar ratio is 0.4:0.08:0Lithium hexafluorophosphate (LiPF) of 0.046) Lithium tetrafluoroborate (LiBF)4) Lithium acetate (LiAc) and lithium metaphosphate (LiPO)3) A mixture of four lithium salts, and lithium perfluorobutylsulfonate (LFS), lithium bis (perfluoro-1-butyryl) imide (BFI), lithium phosphate (Li) in a molar ratio of 2.5% by mole of the electrolyte3PO4) And lithium metasilicate (Li)2SiO3) And adding the electrolyte additive mixture mixed by the four lithium compounds in equal mass ratio into the electrolyte solvent prepared in the second step, and stirring for 3 hours to prepare a solution with the main electrolyte mass molar concentration of 1.05M.
The safe electrolyte for the lithium ion power battery is prepared according to the method.
The prepared safe electrolyte of the lithium ion power battery is respectively assembled into square soft package lithium ion batteries with the capacities of 5000mAh and 2500mAh, the square soft package lithium ion batteries are charged and discharged under the conditions of 25 ℃ and 50 ℃ and 2C multiplying power charging and discharging, the charging and discharging cycle performance, the high and low temperature performance and the like are tested, and the test results are obtained under the same conditions as the test battery of the example 6: the first charge-discharge cycle discharge capacity of the invention is 5090mAh (101.8% of the design capacity), the charge-discharge cycle charge-discharge retention rate of 1812 weeks is 89.6% (assuming that the charge-discharge cycle with the capacity retention rate lower than 70% of the design capacity does not count the cycle of the service life of the battery), and the service life of the battery of the embodiment is more than 2000 weeks of cycle; the first discharge capacity of the battery of the comparative example was 5036mAh (100.4% of the design capacity, and the service life thereof was 800 weeks), and the charge-discharge cycle capacity retention rate at 891 weeks was only 69.4%; under the condition of 2C multiplying power charge-discharge at 25 ℃, the first discharge capacity is 5199mAh, the open-circuit voltage is more than 3.85V, and the internal resistance is in the range of 18.6-24.3 m omega, compared with the first discharge capacity of 5036mAh, the open-circuit voltage is more than 3.82V, and the internal resistance is in the range of 25.6-28.7 m omega; the overcharge 100% capacity test under the conditions of 2C and 25 ℃ is carried out (the result is detailed in the table 1 and the attached figure 4);
the test results of the assembled 2500mAh cell at 50 ℃ are: the first charge-discharge cycle discharge capacity is 2584mAh (103.4% of the design capacity), the charge-discharge cycle charge-discharge retention rate is 91.4% in 2166 weeks (assuming that the charge-discharge cycle with the capacity retention rate lower than 70% of the design capacity is not counted in the cycle of the service life of the battery), and the service life of the battery in the embodiment is more than 2500 weeks; the first discharge capacity of the battery of the comparative example was 2551mAh (102% of the design capacity, and the service life thereof was 1200 weeks), and the charge-discharge cycle capacity retention rate at 1128 weeks was 79.8%; (see FIG. 5 for details of the results); the rate performance of the cell at 0.2C, 1C, 2C and 5C, 25℃ at a capacity of 2500mAh was tested and compared to the comparative example, and the results are detailed in figure 6.
Example 5:
a preparation method of a lithium ion power battery safety electrolyte comprises the following steps:
first, in a vacuum of 0.8kpa or N2Or under the protection of Ar gas, mixing the mixed solvent in equal volume ratio: TOP (trioctyl phosphate), DMC (dimethyl carbonate), DEC (diethyl carbonate) three lipid mixture, with 15.5% by volume of solvent, mixed with equal volume ratio of cosolvent: three lipid mixtures of PC (propylene carbonate), BC (butylene carbonate) and DEG (ethylene glycol diethyl ester), 3.5 percent of solvent volume, and solvent additives mixed in equal volume ratio: uniformly mixing a mixture of TMP (trimethyl phosphate) and EES (ethyl ethanethiosulfonate) to obtain a solvent mixture, and adding Li mixed with equal mass and 5.5% of the total mass of the solvent mixture into the solvent mixture2O、P2O5Mixing with anhydrous phosphorous acid mixed desiccant, stirring for 0.5 hr, filtering to remove precipitate or solid to ensure H in solvent mixture2O、O2The amount of the catalyst does not exceed 20 ppm; thus obtaining the electrolyte mixed solvent.
Second, vacuum 0.8kpa or N2Or lithium hexafluorophosphate (LiPF) with the molar ratio of 0.5:0.1:0.1:0.05 respectively under the protection of Ar gas6) Lithium tetrafluoroborate (LiBF)4) Lithium acetate (LiAc) and lithium metaphosphate (LiPO)3) A mixture of the four lithium salts, and lithium perfluorobutylsulfonate (LFS), lithium bis (perfluoro-1-butyryl) imide (BFI), lithium phosphate (Li) in a molar ratio of 3.5% by mole of the electrolyte3PO4) And lithium metasilicate (Li)2SiO3) Mixing four lithium salts in equal mass ratioAnd adding the mixed electrolyte additive mixture into the electrolyte solvent prepared in the second step, and stirring for 4 hours to prepare a solution with the main electrolyte mass molar concentration of 1.25M.
The safe electrolyte for the lithium ion power battery is prepared according to the method.
The prepared safe electrolyte of the lithium ion power battery is used for assembling the square soft package lithium ion battery with the capacity of 2500mAh and 5000mAh, the battery is charged and discharged under the condition of 2C multiplying power charging and discharging at the temperature of 80 ℃ and the temperature of 25 ℃, the charging and discharging cycle performance, the high and low temperature performance and the like are tested, and the test is carried out under the same condition as that of the battery of the embodiment 6 as a comparative test battery, and the result is as follows: the first charge-discharge cycle discharge capacity at 80 ℃ is 2353mAh (94.1 percent of the design capacity), the charge-discharge cycle charge-discharge retention rate at 985 weeks is 79.6 percent (assuming that the charge-discharge cycle with the capacity retention rate lower than 70 percent of the design capacity does not count the cycle of the service life of the battery), and the service life of the battery in the embodiment is more than 1000 weeks; the first discharge capacity of the battery of the comparative example is 1919mAh (which is 76.7% of the designed capacity and the service life is 105 weeks), the charge-discharge cycle capacity retention rate at 263 weeks is only 49.9%, and the battery has obvious ballooning; the first discharge capacity is 5212mAh, the open-circuit voltage is more than 3.85V and the internal resistance is within the range of 17.5-22.6 m omega under the condition of 5C multiplying power charge and discharge at 25 ℃, and compared with the first discharge capacity of 5036mAh, the open-circuit voltage is more than 3.82V and the internal resistance is within the range of 25.6-28.7 m omega of the battery; the overcharge 100% capacity test under the conditions of 2C and 25 ℃ is carried out (the result is detailed in the table 1 and the attached figure 7); the discharge efficiency test result of 5000mAh capacity at 25 ℃ and 2C multiplying power is as follows: in the embodiment, the first discharge efficiency is 102.42%, the discharge efficiency of the 1720 th charge-discharge cycle is more than 90%, and the cycle service life (the discharge efficiency is set to be more than 75% of the design capacity) is more than 1735 weeks (the discharge efficiency is 89.85%); the first discharge efficiency of comparative example 6 was 100.01%, the charge-discharge cycle discharge efficiency at week 520 was less than 75% of the designed capacity, and the cycle life was less than 520 weeks (see fig. 8 for details).
Comparative example 6:
the specification of the commonly-used commercially-available electrolyte produced by the existing lithium ion battery is as follows: organic solventThe agent is as follows: ethylene Carbonate (EC), dimethyl carbonate (DMC), Ethyl Methyl Carbonate (EMC) in a volume ratio of 1:1:1, and an electrolyte: LiPF6The concentration is 1.0 to 1.25 mol/L. The electrolyte is selected to be prepared into the electrolyte corresponding to each embodiment of the invention, namely LiPF6The concentration of the electrolyte additive is the same as the total concentration of the electrolyte and the electrolyte additive in the electrolyte, the square soft package lithium ion battery with the capacity of 5000mAh or 2500mAh is assembled, the battery is charged and discharged under the condition of 0.2C-5C multiplying power charging and discharging at the temperature of minus 50-80 ℃, the charging and discharging cycle performance, the high and low temperature performance and the like are tested, the test is carried out under the same condition as the comparative test battery, and the results are detailed in a table 1 and attached figures 6-8.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims (8)

1. The safe electrolyte of the lithium ion battery is characterized by comprising an electrolyte, an electrolyte additive, a solvent, a cosolvent and a solvent additive, wherein:
the electrolyte is a mixture of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium acetate and lithium metaphosphate, wherein the molar ratio of the lithium hexafluorophosphate, the lithium tetrafluoroborate, the lithium acetate and the lithium metaphosphate is 0.1-0.5: 0.05-0.1: 0.05-0.05;
the electrolyte additive is a mixture of any two or three or four of perfluorobutyl lithium sulfonate, bis (perfluoro-1-butyryl) imide lithium, lithium phosphate or lithium metasilicate in a molar ratio of 0.9-1.1: 0.9-1.1, and the molar percentage of the electrolyte additive to the electrolyte is 1.0-3.5%;
the solvent is a mixture of any three or four or five of tributyl phosphate, tripentyl phosphate, trioctyl phosphate, dimethyl carbonate or diethyl carbonate in a volume ratio of 0.9-1.1: 0.9-1.1;
the cosolvent is a mixture of any two or three or four of methyl ethyl carbonate, ethylene carbonate, propylene carbonate, butylene carbonate, ethylene glycol diethyl ester or 2, 4-butane sultone in a volume ratio of 0.9-1.1: 0.9-1.1, and the volume percentage of the cosolvent to the solvent is 6.5-15.5%;
the solvent additive is a mixture of any two of trimethyl phosphate, triethyl phosphate, triphenyl phosphate, diisoamyl phosphate or ethyl ethanethiosulfonate in a volume ratio of 0.9-1.1: 0.9-1.1, and the volume ratio of the solvent additive to the solvent is 1.0-3.5%;
in the safe electrolyte of the lithium ion battery, the total molar concentration of the electrolyte and the electrolyte additive is 0.2-1.25M.
2. The lithium ion battery safety electrolyte of claim 1, wherein:
the electrolyte additive is a mixture of any two or three or four of lithium perfluorobutylsulfonate, lithium bis (perfluoro-1-butyryl) imide, lithium phosphate or lithium metasilicate which are mixed according to an equal molar ratio, and the molar percentage of the electrolyte additive to the electrolyte is 1.0-3.5%;
the solvent is a mixture of any three or four or five of tributyl phosphate, tripentyl phosphate, trioctyl phosphate and dimethyl carbonate) or diethyl carbonate which are mixed in equal volume ratio;
the cosolvent is a mixture of any two or three or four of methyl ethyl carbonate, ethylene carbonate propylene carbonate, butylene carbonate, ethylene glycol diethyl ester or 2, 4-butane sultone which are mixed in an equal volume ratio, and the volume percentage of the cosolvent to the solvent is 6.5-15.5%;
the solvent additive is a mixture of any two of trimethyl phosphate, triethyl phosphate, triphenyl phosphate, diisoamyl phosphate or ethyl ethanethiosulfonate which are mixed in an equal volume ratio, and the volume ratio of the solvent additive to the solvent is 1.0-3.5%.
3. A preparation method of a lithium ion battery safety electrolyte is characterized by comprising the following steps:
1) under the condition of vacuum or protective atmosphere, mixing a solvent cosolvent, a solvent additive and a drying agent, uniformly stirring, and filtering out precipitates or solids to obtain a mixed solvent;
2) adding electrolyte and electrolyte additive which are dried to constant weight into the mixed solvent obtained in the step 1) under the condition of vacuum or protective atmosphere at 60-85 ℃, and uniformly stirring under the condition of vacuum or protective atmosphere to prepare the safe electrolyte of the lithium ion battery;
wherein:
the electrolyte is a mixture of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium acetate and lithium metaphosphate, wherein the molar ratio of the lithium hexafluorophosphate, the lithium tetrafluoroborate, the lithium acetate and the lithium metaphosphate is 0.1-0.5: 0.05-0.1: 0.05-0.05;
the electrolyte additive is a mixture of any two or three or four of perfluorobutyl lithium sulfonate, bis (perfluoro-1-butyryl) imide lithium, lithium phosphate or lithium metasilicate in a molar ratio of 0.9-1.1: 0.9-1.1, and the molar percentage of the electrolyte additive to the electrolyte is 1.0-3.5%;
the solvent is a mixture of any three or four or five of tributyl phosphate, tripentyl phosphate, trioctyl phosphate, dimethyl carbonate or diethyl carbonate in a volume ratio of 0.9-1.1: 0.9-1.1;
the cosolvent is a mixture of any two or three or four of methyl ethyl carbonate, ethylene carbonate, propylene carbonate, butylene carbonate, ethylene glycol diethyl ester or 2, 4-butane sultone in a volume ratio of 0.9-1.1: 0.9-1.1, and the volume percentage of the cosolvent to the solvent is 6.5-15.5%;
the solvent additive is a mixture of any two of trimethyl phosphate, triethyl phosphate, triphenyl phosphate, diisoamyl phosphate or ethyl ethanethiosulfonate in a volume ratio of 0.9-1.1: 0.9-1.1, and the volume ratio of the solvent additive to the solvent is 1.0-3.5%;
the drying agent is Li with the mass ratio of 0.9-1.1: 0.9-1.12O、P2O5And anhydrous phosphorous acid, wherein the mass percentage of the mass of the composite drying agent to the total mass of the solvent, the cosolvent and the solvent additive is 3.5-5%;
in the safe electrolyte of the lithium ion battery, the total molar concentration of the electrolyte and the electrolyte additive is 0.2-1.25M.
4. The preparation method of the lithium ion battery safety electrolyte according to claim 3, characterized in that:
in the step 1), the vacuum degree is 0.3-0.8 kpa; protective gas is N2Or Ar; stirring for 0.5-4 h; h in the mixed solvent2O and O2The content of (A) is less than 20 ppm;
in the step 2), the vacuum degree in the material mixing process is 0.3-0.8 kpa; the protective gas in the material mixing process is N2Or Ar; the vacuum degree in the stirring process is 0.3-0.8 kpa; the protective gas in the stirring process is N2Or Ar; the stirring time is 0.5-4 hours.
5. The preparation method of the lithium ion battery safety electrolyte according to claim 3 or 4, characterized in that:
the electrolyte additive is a mixture of any two or three or four of lithium perfluorobutylsulfonate, lithium bis (perfluoro-1-butyryl) imide, lithium phosphate or lithium metasilicate which are mixed according to an equal molar ratio, and the molar percentage of the electrolyte additive to the electrolyte is 1.0-3.5%;
the solvent is a mixture of any three or four or five of tributyl phosphate, tripentyl phosphate, trioctyl phosphate, dimethyl carbonate or diethyl carbonate which are mixed in equal volume ratio;
the cosolvent is a mixture of any two or three or four of methyl ethyl carbonate, ethylene carbonate, propylene carbonate, butylene carbonate, ethylene glycol diethyl ester or 2, 4-butane sultone which are mixed in an equal volume ratio, and the volume percentage of the cosolvent to the solvent is 6.5-15.5%;
the solvent additive is a mixture of any two of trimethyl phosphate, triethyl phosphate, triphenyl phosphate, diisoamyl phosphate or ethyl ethanethiosulfonate which are mixed in an equal volume ratio, and the volume ratio of the solvent additive to the solvent is 1.0-3.5%;
the drying agent is Li mixed by equal mass2O、P2O5And a composite desiccant of anhydrous phosphorous acid.
6. The lithium ion battery safety electrolyte prepared by the preparation method of the lithium ion battery safety electrolyte according to any one of claims 3 to 5.
7. Use of the lithium-ion battery safety electrolyte according to claim 1, 2 or 6, characterized in that: the electrolyte is used as the electrolyte of the lithium ion power battery.
8. A lithium ion battery comprising the lithium ion battery safety electrolyte of claim 1, 2 or 6.
CN201911200909.0A 2019-11-29 2019-11-29 Lithium ion battery safety electrolyte, preparation method and application thereof, and lithium ion battery Active CN110994023B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201911200909.0A CN110994023B (en) 2019-11-29 2019-11-29 Lithium ion battery safety electrolyte, preparation method and application thereof, and lithium ion battery

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201911200909.0A CN110994023B (en) 2019-11-29 2019-11-29 Lithium ion battery safety electrolyte, preparation method and application thereof, and lithium ion battery

Publications (2)

Publication Number Publication Date
CN110994023A true CN110994023A (en) 2020-04-10
CN110994023B CN110994023B (en) 2023-05-16

Family

ID=70088314

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201911200909.0A Active CN110994023B (en) 2019-11-29 2019-11-29 Lithium ion battery safety electrolyte, preparation method and application thereof, and lithium ion battery

Country Status (1)

Country Link
CN (1) CN110994023B (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114400377A (en) * 2021-12-28 2022-04-26 大连中比动力电池有限公司 Additive and electrolyte for sodium ferrite sodium ion battery
CN117154233A (en) * 2023-11-01 2023-12-01 英德市科恒新能源科技有限公司 Lithium ion battery multiplying power type electrolyte, preparation method and lithium ion battery

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA2164385A1 (en) * 1995-12-04 1997-06-05 Qiming Zhong Low Viscosity Electrolyte Comprising P2O5 for Use in Non-Aqueous Rechargeable Lithium Batteries
CN102082295A (en) * 2010-12-29 2011-06-01 东莞市杉杉电池材料有限公司 Electrolyte of lithium-ion secondary battery
US20120141883A1 (en) * 2008-08-19 2012-06-07 University Of Southern California Lithium-Ion Electrolytes With Improved Safety Tolerance To High Voltage Systems
CN102637901A (en) * 2012-04-24 2012-08-15 广州市云通磁电有限公司 Electrolyte for lithium ion battery and preparation method thereof
WO2013050283A1 (en) * 2011-10-05 2013-04-11 Varta Microbattery Gmbh Lithium-ion cells having improved properties
CN103811811A (en) * 2012-11-06 2014-05-21 万向电动汽车有限公司 Flame retardant electrolyte applied to lithium ion power battery and lithium ion power battery prepared from same
CN104112869A (en) * 2013-04-19 2014-10-22 南通力合新能源有限公司 Nonaqueous electrolyte additive capable of improving high-temperature impedance performance of manganese-contained lithium ion battery
CN105118983A (en) * 2015-09-16 2015-12-02 湖北宇电能源科技股份有限公司 Method for preparing lithium nickel manganese oxide anode material
WO2018174924A1 (en) * 2017-03-23 2018-09-27 Nanotek Instruments, Inc. Non-flammable quasi-solid electrolyte and lithium secondary batteries containing same

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA2164385A1 (en) * 1995-12-04 1997-06-05 Qiming Zhong Low Viscosity Electrolyte Comprising P2O5 for Use in Non-Aqueous Rechargeable Lithium Batteries
US20120141883A1 (en) * 2008-08-19 2012-06-07 University Of Southern California Lithium-Ion Electrolytes With Improved Safety Tolerance To High Voltage Systems
CN102082295A (en) * 2010-12-29 2011-06-01 东莞市杉杉电池材料有限公司 Electrolyte of lithium-ion secondary battery
WO2013050283A1 (en) * 2011-10-05 2013-04-11 Varta Microbattery Gmbh Lithium-ion cells having improved properties
CN102637901A (en) * 2012-04-24 2012-08-15 广州市云通磁电有限公司 Electrolyte for lithium ion battery and preparation method thereof
CN103811811A (en) * 2012-11-06 2014-05-21 万向电动汽车有限公司 Flame retardant electrolyte applied to lithium ion power battery and lithium ion power battery prepared from same
CN104112869A (en) * 2013-04-19 2014-10-22 南通力合新能源有限公司 Nonaqueous electrolyte additive capable of improving high-temperature impedance performance of manganese-contained lithium ion battery
CN105118983A (en) * 2015-09-16 2015-12-02 湖北宇电能源科技股份有限公司 Method for preparing lithium nickel manganese oxide anode material
WO2018174924A1 (en) * 2017-03-23 2018-09-27 Nanotek Instruments, Inc. Non-flammable quasi-solid electrolyte and lithium secondary batteries containing same

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
何争珍;杨明明;: "锂离子电池电解液及功能添加剂的研究进展" *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114400377A (en) * 2021-12-28 2022-04-26 大连中比动力电池有限公司 Additive and electrolyte for sodium ferrite sodium ion battery
CN117154233A (en) * 2023-11-01 2023-12-01 英德市科恒新能源科技有限公司 Lithium ion battery multiplying power type electrolyte, preparation method and lithium ion battery
CN117154233B (en) * 2023-11-01 2024-02-02 英德市科恒新能源科技有限公司 Lithium ion battery multiplying power type electrolyte, preparation method and lithium ion battery

Also Published As

Publication number Publication date
CN110994023B (en) 2023-05-16

Similar Documents

Publication Publication Date Title
CN105845983B (en) Electrolyte and lithium ion battery containing same
JP2023043812A (en) Non-aqueous electrolyte for lithium ion battery and use thereof
CN111048830B (en) Nonaqueous electrolyte solution and lithium ion secondary battery
KR101298868B1 (en) Nonaqueous electrolyte and lithium-ion secondary battery using thereof
CN113140796B (en) Lithium ion battery electrolyte and lithium ion battery containing same
CN112448037A (en) Lithium supplementing composition, lithium supplementing electrolyte and lithium supplementing method for lithium secondary battery
WO2022199163A1 (en) Non-aqueous electrolyte additive, non-aqueous electrolyte and lithium ion battery
CN111710906A (en) High-stability lithium ion battery electrolyte and battery containing same
CN110994023B (en) Lithium ion battery safety electrolyte, preparation method and application thereof, and lithium ion battery
CN113161615A (en) Non-aqueous electrolyte of lithium ion battery and lithium ion battery
CN113066975B (en) Lithium ion battery
CN109309248B (en) Electrolyte solution and secondary battery
CN116646526B (en) Positive electrode interface film of sodium ion battery, preparation method of positive electrode interface film and sodium ion battery
CN114883648B (en) Non-aqueous electrolyte of lithium ion battery and lithium ion battery
CN111883834A (en) Non-aqueous lithium ion battery electrolyte additive, electrolyte containing non-aqueous lithium ion battery electrolyte additive and lithium ion battery
CN116632354A (en) Lithium battery and electrolyte for lithium battery
CN110635166A (en) Electrolyte, battery containing electrolyte and electric vehicle
CN111883828B (en) Non-aqueous electrolyte of lithium ion battery and lithium ion battery
CN115020806A (en) Electrolyte and lithium ion battery containing same
CN112038697A (en) Lithium ion battery non-aqueous electrolyte and lithium ion battery
CN114335724B (en) High-voltage lithium ion battery electrolyte and lithium ion battery
CN110994024B (en) Electrolyte additive, electrolyte and lithium ion battery
CN114188608B (en) Boron-containing sulfonate non-aqueous electrolyte additive and lithium ion battery prepared from same
CN113764736B (en) Electrolyte for lithium ion battery, preparation method of electrolyte and lithium ion battery
CN111883835A (en) Non-aqueous electrolyte of lithium ion battery and lithium ion battery

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant