WO2018169112A1 - Additif d'électrolyte pour batterie secondaire au lithium et son procédé de préparation, électrolyte comprenant un additif et son procédé de préparation, et batterie secondaire au lithium comprenant un additif - Google Patents

Additif d'électrolyte pour batterie secondaire au lithium et son procédé de préparation, électrolyte comprenant un additif et son procédé de préparation, et batterie secondaire au lithium comprenant un additif Download PDF

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Publication number
WO2018169112A1
WO2018169112A1 PCT/KR2017/002942 KR2017002942W WO2018169112A1 WO 2018169112 A1 WO2018169112 A1 WO 2018169112A1 KR 2017002942 W KR2017002942 W KR 2017002942W WO 2018169112 A1 WO2018169112 A1 WO 2018169112A1
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Prior art keywords
lithium
additive
unsubstituted
borate
substituted
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PCT/KR2017/002942
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English (en)
Korean (ko)
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최남순
조재필
홍성유
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울산과학기술원
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Priority to PCT/KR2017/002942 priority Critical patent/WO2018169112A1/fr
Publication of WO2018169112A1 publication Critical patent/WO2018169112A1/fr

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    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07F—ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM
    • C07F5/00—Compounds containing elements of Groups 3 or 13 of the Periodic Table
    • C07F5/02—Boron compounds
    • 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
    • H01M10/056—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
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
    • 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

  • Electrolyte Additive for Lithium Secondary Battery and Manufacturing Method Thereof Electrolyte Containing the Additive and Manufacturing Method Thereof, and Lithium Secondary Battery Lithium Secondary Battery
  • the present invention relates to an electrolyte additive for a lithium secondary battery, a method for manufacturing the same, an electrolyte including the additive, a method for producing the same, and a lithium secondary battery including the additive.
  • the layer charge driving voltage of the battery may be improved, and a silicon-based material as well as a carbon-based material may be used. Since it can be used as a negative electrode active material, the capacity of a battery can be improved.
  • lithium salt dissolved in an organic solvent is used as an electrolyte.
  • the overlithium positive electrode active material generates a high-voltage environment and generates oxygen gas during the first layer charge, and the silicon-based negative electrode active material is repeatedly charged and discharged. As a result, severe volume expansion occurs and cracking is formed on the surface of the electrode, which eventually causes decomposition reaction of the electrolyte on the surface of the electrode to which each active material is applied.
  • the electrolyte is gradually depleted and the electrochemical performance of the battery is rapidly deteriorated.
  • a thick film acting as a resistance is formed on the surface of each electrode, so that the rate of electrochemical reaction of the battery is reduced, and the decomposition of the electrolyte is generated.
  • the acidic material for example, HF, etc.
  • the present invention provides materials (ie, additives) added to an electrolyte for a lithium secondary battery, a method of manufacturing the same, and a lithium secondary battery comprising the same.
  • a material capable of being oxidatively decomposed to form a protective film on the surface of the anode is provided as an oxidative decomposition type additive.
  • a reduction decomposition type additive which is a substance that is reduced and decomposed to form a protective film on the surface of the negative electrode, and an additive having a semi-ungung additive capable of removing an acidic substance to provide.
  • an electrolyte including the additive, a method for preparing the same, and a lithium secondary battery to which the additive is applied.
  • an electrolyte additive for a lithium secondary battery which is an oxidative decomposition type additive, including a compound represented by the following Chemical Formula 1, a compound represented by the following Chemical Formula 2, or a mixture thereof:
  • 3 ⁇ 4 and 1 2 are each independently hydrogen, a substituted or unsubstituted C1 to C8 alkyl group, a substituted or unsubstituted C1 to C8 perfluoro alkyl group, a substituted or unsubstituted C6 to C30 arene (arene) Groups, substituted or unsubstituted C6 to C30 perfluoro arene (arene) groups, CF 3 , halogen elements (F, CI, Br, or l), or a combination thereof.
  • ⁇ is 1 or 2
  • m is 1 or 2.
  • the oxidative decomposition type additive lithium difluoro (malonate) borate (Lithium difluoro (malonato) borate, JB-HLiB), lithium difluoro (fluoromalonate) borate (Lithium difluoro (fluoroinalonato) borate, JB-FLiB), lithium difluoro (difluoromalonato) borate (Lithium difluoro (difluoromalonato) borate, JB-DFLiB), lithium difluoro (bromomalonato) borate (lithium difluoro (bromomalonato) borate), lithium difluoro (c loromalonato) borate, lithium difluoro (iodomalonato) borate, lithium difluoro (both) Lithium difluoro (phenylmalonato) borate, lithium difluoro (perfluoromalonato) borate, lithium
  • the compound represented by the following formula (3) And reacting the boron raw material to produce an oxidatively decomposable additive, which provides a method for producing an electrolyte additive for a lithium secondary battery.
  • Ri and 1 2 are each independently hydrogen, a substituted or unsubstituted C1 to C8 alkyl group, a substituted or unsubstituted C1 to C8 perfluoro alkyl group, a substituted or unsubstituted C6 to C30 arene (arene) group, substituted or unsubstituted C6 to C30 perfluoro arene (arene) group, CF 3 , halogen element (F, CI, Br, or I), or a combination thereof.
  • A is lithium, sodium, or hydrogen.
  • the boron raw material may be a compound represented by Chemical Formula 4, lithium tetrafluoroborate (LiBF 4 ), or a combination thereof.
  • R 3 and R 4 are each independently hydrogen, a substituted or unsubstituted C1 to C8 alkyl group, a substituted or unsubstituted C1 to C8 perfluoro alkyl group, a substituted or unsubstituted C6 to C30 arene (arene) group, substituted or unsubstituted C6 to C30 perfluoro arene (arene) group, CF 3 , halogen element (F, CI, Br, or I), or a combination thereof.
  • X is a halogen element (F, CI, Br, or I), or a combination thereof.
  • the step of preparing the oxidative decomposition type additive at a temperature range of 0 to 150 ° C, carbonate-based, ester-based, ether-based, ketone-based, alcohol-based, aprotic solvent, or a combination thereof Using solvent, wet It may be carried out, the execution time may be greater than 0 hours and up to 24 hours ⁇ step of preparing the oxidative decomposition type additive; in the compound represented by the following formula (1), the compound represented by the following formula (2), or their The mixture can be prepared.
  • a reduction decomposition type additive including one of fluoroethylene carbonate (FEC) and vinylene carbonate (VC), or a combination thereof;
  • An oxidative decomposition type additive comprising a compound represented by the following Chemical Formula 1, a compound represented by the following Chemical Formula 2, or a mixture thereof;
  • an additive comprising a reactive additive which is a compound containing a silyl group.
  • the oxidatively decomposable additive may be at least one selected from the above materials.
  • the reactive additive is. Tris (trimethylsilyl) phosphite (TMSP), Tris (trimethylsilyl) methane (T-TMSM) Bis (trimethylsilyl) methane (B- BMSM), Tris (trimethylsilyl) amine (T-TMSA), Bis (trimethylsilyl) amine (B is (trimethylsilyl) amine, B-TMSA), Bis (trimethylsilyl) sulfide bis (trimethylsilyl Sulfide Bis (trimethylsilyl) sulfide, B-TMSSi), Bis (trimetylsiloxy) et ane, B-TMSE), Bis (trimethylsilylt io) ethane, B -TMSSE), Trimethylsilyl isothiocyanate (TMS ITC), Trimethylsilyl isocyanate (TMS IC), trimethyl (phenylselenometliyl) silane (TMPSeS), trimethyl ( Ph
  • the compound represented by the formula (3) by reacting the compound represented by the formula (3) and the boron raw material to prepare an oxidative decomposition type additive; And mixing the oxidatively decomposable additive with the reductively decomposable additive and the reactive additive, wherein the reductive decomposition additive includes fluoroethylene carbonate (FEC) and vinylene carbonate (vinylene carbonate, VC). ), Or a combination thereof, wherein the semi-formular additive is a compound comprising a silyl group, providing a method for preparing an electrolyte additive for a lithium secondary battery:
  • FEC fluoroethylene carbonate
  • VVC vinylene carbonate
  • the boron raw material may be a compound represented by the following Chemical Formula 4, lithium tetrafluoroborate (Lithium tetrafluoroborate, LiBF 4 ), or a combination thereof.
  • an organic solvent First lithium salt; And an additive; wherein the additive is an oxidative decomposition type additive including a compound represented by the following Chemical Formula 1, a compound represented by the following Chemical Formula 2, or a combination thereof, and provides an electrolyte for a lithium secondary battery.
  • the additive is an oxidative decomposition type additive including a compound represented by the following Chemical Formula 1, a compound represented by the following Chemical Formula 2, or a combination thereof, and provides an electrolyte for a lithium secondary battery.
  • the content of the oxidative decomposition type additive in the electrolyte may be 0 ⁇ 5 to 2% by weight.
  • the first lithium salt is, lithium hexafluorophosphate (Lithium hexafluorophosphate, LiPF 6 ), lithium tetrafluoroborate (Lithium tetrafluoroborate, LiBF 4 ), lithium perchlorate (Lithium perchlorate, LiC10 4 ), lithium nuxafluoroarsenate (Lithium hexafluoro arsenate, LiAsF 6 ), lithium Lithium bis (oxalato) borate (LiBOB), Lithium bis (fluorosulfonyl) imide (LiFSI) and Lithium fluoro (oxalate) borate (LiFOB) It may be at least one selected from among.
  • the concentration of the first lithium salt in the electrolyte may be 0.1 to 2 M.
  • the organic solvent is a carbonate, ester ,. It may be an organic solvent which is an ether type, a ketone type, an alcohol type, an aprotic solvent, or a combination thereof. For example, it may be ethylene carbonate (EC), ethyl methyl carbonate (EMC), dimethyl carbonate (dimethyl catbonate, DMC), diethyl carbonate (DEC), or a combination thereof. .
  • EC ethylene carbonate
  • EMC ethyl methyl carbonate
  • DMC dimethyl carbonate
  • DEC diethyl carbonate
  • Formula 3 wherein the oxidation step for producing a decomposable additive; details of the, and the additive obtained common combined with the oxidizing decomposable additives, the first lithium salt, and an organic solvent is like described above, the detailed description Omit.
  • an organic solvent Crab 1 lithium salt;
  • an additive including a reduction decomposition additive, an oxidative decomposition additive, and a semi-ung additive, wherein the reduction decomposition additive includes fluoroethylene carbonate (FEC) and vinylene carbonate (VC).
  • FEC fluoroethylene carbonate
  • VC vinylene carbonate
  • the oxidatively decomposable additive is a compound represented by the following Chemical Formula 1, A compound, or a mixture thereof, and the semi-amorphous additive provides a electrolyte for a lithium secondary battery, which is a compound containing a silyl group.
  • the amount of the additive in the electrolyte may be 5 to 19% by weight of the total weight of the electrolyte 100% by weight.
  • the total weight of the additive increases by 100% by weight, the reduction decomposition type additive is included 5 to 12% by weight 0 /., The oxidative decomposition type additive is contained 0.05 to 2% by weight, the semi-finished additive is 0.1 to 5% by weight It may be included.
  • the concentration of the first lithium salt in the electrolyte, and the details of the organic solvent are as described above, and a detailed description thereof will be omitted.
  • a positive electrode including a lithium-rich positive electrode active material; A negative electrode including a silicon-based negative active material; And an electrolyte comprising an organic solvent, a first lithium salt, and an additive; wherein the additive is an oxidative decomposition type including a compound represented by the following Chemical Formula 1, a compound represented by the following Chemical Formula 2, or a combination thereof It provides a lithium secondary battery which is an additive.
  • a positive electrode including a lithium-rich positive electrode active material; A negative electrode including a silicon-based negative active material; And an electrolyte comprising an organic solvent, a system 1 lithium salt, and an additive, wherein the additive includes a reduction decomposition additive, an oxidative decomposition additive, and a semi-ung additive, wherein the reduction decomposition additive is fluoro.
  • FEC Ethylene carbonate
  • VC vinylene carbonate
  • the oxidative decomposition additive is a compound represented by the following formula (1), Compound, or a combination thereof, wherein the semi-formular additive is a compound comprising a silyl group, lithium
  • a lithium-rich positive electrode active material may include a compound represented by the following Formula 5.
  • the silicon-based negative active material may be a combination of graphite and silicon, a material coated with silicon on the surface of the graphite particles, or a material simultaneously coated with silicon and carbon on the surface of the graphite particles.
  • the average layer voltage of the gig-lithium secondary battery may be 4.5 V or more.
  • a high-voltage and high-capacity lithium battery is applied by simultaneously applying an overlithium cathode active material and a silicon-based anode active material.
  • the electrochemical performance, reaction speed and stability of the battery may be improved by the functional additive included with the organic solvent and the first lithium salt.
  • a protective film may be formed on the surface of the anode by an oxidative decomposition type additive.
  • the protective film is formed on the surface of the positive electrode by the oxidative decomposition type additive, the protective film is formed on the surface of the negative electrode by the reduction decomposition type additive, it may be performed at the same time to remove the acidic material by the reactive additive.
  • FIG. 1 is an exploded perspective view of a rechargeable lithium battery according to one embodiment of the present invention.
  • FIG. 2 is a chemical structural diagram illustrating various oxidative decomposition type additives that may be included in a lithium secondary battery according to one embodiment of the present invention.
  • FIG. 3 shows the results of evaluation of high temperature life characteristics of the overlithium positive electrode half cell of each lithium secondary battery of Example 1 and Comparative Example 1 of the present invention.
  • 4 shows the evaluation results of room temperature life characteristics of the graphite negative electrode half cell of each lithium secondary battery of Example 2 and Comparative Example 2 of the present invention.
  • FIG. 5 shows the results of evaluation of high rate discharge characteristics of the overlithium positive electrode half cell of each lithium secondary battery of Example 3 and Comparative Example 3 of the present invention.
  • FIG. 6 shows the results of evaluation of room temperature life performance of a full cell using an overlithium positive electrode and a silicon-based negative electrode for each lithium secondary battery of Example 4 and Comparative Example 4 of the present invention.
  • FIG. 7 shows changes in open circuit voltage during high temperature storage of a full cell using an overlithium positive electrode and a silicon-based negative electrode for each lithium secondary battery of Example 4 and Comparative Example 4 of the present invention.
  • FIG. 8 shows capacity retention rates after high-temperature storage of a full cell using an overririum positive electrode and a silicon-based negative electrode for each of the lithium secondary batteries of Example 4 and Comparative Example 4 of the present invention.
  • Example 9 is for each lithium secondary battery of Example 5 and Comparative Example 5 of the present invention The results of the evaluation of the room temperature life performance of a full cell using a LiCo0 2 anode and a graphite-based cathode are shown.
  • Example 10 shows the results of evaluation of high temperature life performance of a full cell using a LiCo0 2 positive electrode and a graphite negative electrode for each lithium secondary battery of Example 5 and Comparative Example 5 of the present invention.
  • Figure 11 shows the HF removal effect of the semi-ungsung additives of Example 6 and Comparative Example 6 of the present invention.
  • Lithium secondary batteries may be classified into lithium secondary batteries, lithium ion polymer batteries, and lithium polymer batteries according to the type of separator and electrolyte used, and may be classified into cylindrical, square, coin, and pouch types according to their type. Depending on the size, it can be divided into bulk type and thin film type. Since the structure and manufacturing method of these batteries are well known in the art, detailed description thereof will be omitted.
  • FIG. 1 illustrates an example of a cylindrical lithium secondary battery 100, which includes a negative electrode 112, a positive electrode II 4 , a separator 113 disposed between the negative electrode 11 and a positive electrode II 4 , and the negative electrode 112. ), And an electrolyte (not shown) impregnated in the positive electrode 114 and the separator 113.
  • the lithium secondary battery 100 may further include a battery container 120 and an encapsulation member 140 encapsulating the battery container 120.
  • the lithium secondary battery 100 is configured by stacking the negative electrode 112, the separator 113, and the positive electrode 114 in order, and then storing the lithium secondary battery 100 in the battery container 120 in a state of being wound in a spiral shape.
  • the negative electrode 112 includes a current collector and a negative electrode active material layer formed on the current collector, and the negative electrode active material layer includes a negative electrode active material.
  • the negative electrode active material may be a material capable of reversibly intercalating / deintercalating lithium ions, lithium metal, an alloy of lithium metal, and may dope and undo lithium. Materials, or transition metal oxides are used.
  • carbon-based materials such as graphite are widely known as materials capable of reversibly intercalating / deintercalating lithium ions, and graphite has a low discharge voltage of -0.2 V compared to lithium, and thus the negative electrode active material
  • the battery having the high discharge voltage of 3.6 V provides the advantage in terms of the energy density of the lithium battery, and also the reversibility of ensuring the long life of the lithium secondary battery is the most widely used.
  • the graphite active material has a problem of low capacity in terms of energy density per unit volume of the electrode plate due to the low graphite density (theoretical density of 2.2 gAx) in the production of the electrode plate, and it is easy to cause side reaction with the organic electrolyte used at high discharge voltage.
  • the positive electrode 114 includes a current collector and a positive electrode active material layer formed on the current collector.
  • a compound (lithiated intercalation compound) capable of reversible intercalation and deintercalation of lithium may be used, and generally, LiCo0 2 , LiMn 2 O 4 , LiNii.
  • a lithium salt dissolved in an organic solvent is used as an electrolyte.
  • the overlithium positive electrode active material generates a high voltage environment and generates oxygen gas during the first layer discharge, and the silicon-based negative electrode active material repeatedly discharges the layer.
  • severe volume expansion occurs and cracking is formed on the surface of the electrode, which eventually causes decomposition reaction of the electrolyte on the surface of the electrode to which each active material is applied.
  • the electrolyte is gradually depleted and the electrochemical performance of the battery is rapidly deteriorated.
  • Electrolyte Additives for Lithium Secondary Batteries provide a combination of (1) an oxidatively degradable additive alone, and (2) a reductively degradable additive, an oxidatively degradable additive, and a semi-ung additive.
  • a functional additive consisting of three additives is presented, respectively.
  • the functional additive includes the reduction decomposition type additive, the oxidative decomposition type additive, and the semi-ung additive type, and in the following description, the three additives are collectively referred to as "additives” or black "functional additives”. Shall be.
  • the oxidatively decomposable additive is a material that functions to oxidatively decompose to form a protective film on the surface of the anode, and prevents electrolyte decomposition reaction from occurring at the surface of the anode.
  • an electrolyte additive for a lithium secondary battery which is an oxidative decomposition type additive, including a compound represented by the following formula (1), a compound represented by the following formula (2), or a mixture thereof do:
  • 3 ⁇ 4 and R 2 are each independently hydrogen, a substituted or unsubstituted C1 to C8 alkyl group, a substituted or unsubstituted C1 to C8 perfluoro alkyl group, a substituted or unsubstituted C6 to C30 arene (arene) Groups, substituted or unsubstituted C6 to C30 perfluoro arene groups, CF 3 , halogen elements (F, CI, Br, or I), or combinations thereof.
  • ⁇ is 1 or 2 and m is 1 or 2.
  • the oxidatively decomposable additive may include lithium difluoro (maloneto) borate (Lithium difluoro (malonato) borate (JB-HLiB), lithium difluoro (fluoromalonate) borate (Lithium difluoro ( fluoromalo nato) bor ate, JB-FLiB), lithium difluoro (difluoromalonato) borate (Lithium difluoro (difluoromalonato) borate, JB-DFLiB), lithium difluoro (bromomalonato) borate (lithium difluoro (bromomalonato) borate, lithium difluoro (chloromalonato) borate, lithium difluoro (iodomalonato) borate, lithium difluoro Lithium difluoro (p enylmalonato) borate, lithium difluoro (perfluoromalo
  • Figure 2 is the oxidative decomposition additive additive, lithium difluoro (malonato) borate (Lithium difluoro (malonato) borate, JB-HLiB), lithium difluoro (fluoromaloneto) Lithium difluoro (difluoromalonato) borate (JB-FLiB), Lithium difluoro (difluoromalonato) borate (JB-DFLiB), Lithium difluoro (bromomalonato) Borate (lithium difluoro (bromomalonato) borate), Lithium difluoro (chloromalonato) borate, Lithium difluoro (iodomalonato) borate, Lithium Lithium difluoro (phenylmalonato) borate, Lithium difluoro (perfluoromalonato) borate, Lithium difluoro (trimalmalon
  • the oxidative decomposition type additive may be oxidatively decomposed before the lithium salt in the electrolyte when the lithium secondary battery is driven, thereby forming a stable protective film on the surface of the positive electrode.
  • the oxidative decomposition type additive may be oxidatively decomposed before the lithium salt in the electrolyte to form a solid electrolyte interface (SEI) on the surface of the positive electrode.
  • SEI solid electrolyte interface
  • Solid electrolyte interface solid electrolyte interface, formed on the surface of the anode
  • SEI performs a function of stably protecting the positive electrode without acting as a resistance of the battery, thereby preventing the organic solvent, the primary lithium salt, from directly contacting the surface of the positive electrode.
  • the functional additives are fluoroethylene carbonate (fluoroethylene carbonate, FEC) and vinylene carbonate (vinylene carbonate, VC) reduction decomposition type additive; Oxidative decomposition type additives having a higher tendency for oxidative decomposition than lithium salts in the electrolyte; And semi-additives which are compounds containing a silyl group; three kinds of additives.
  • the reduction decomposition additive is reduced decomposition to form a protective film on the surface of the cathode
  • the oxidation decomposition additive is oxidatively decomposition .
  • a protective film is formed on the surface of the anode
  • the semi-finished additive performs a function of removing an acidic substance (for example, HF, etc.), and the functional additive includes all of the three additives, thereby providing a respective function. This is done at the same time.
  • the reduction decomposition type additive and the oxidative decomposition type additive mainly form a stable protective film on the surface of each electrode to prevent the aforementioned electrolyte decomposition reaction from occurring and at the same time, even if the electrolyte decomposition reaction occurs.
  • the semi-aung form additive can effectively remove the acidic substance which is the decomposition product.
  • the functional additives in particular, the per lithium positive electrode active material and
  • a silicon-based negative active material at the same time to implement a high voltage and high capacity lithium secondary battery, by maintaining the structure of the active material while the battery is stable, it can contribute to improve the electrochemical performance, reaction speed and stability of the battery.
  • the functional additive may be applied to a battery to which any electrode active material is applied to perform the above function.
  • a reduction decomposition type additive including one of fluoroethylene carbonate (FEC) and vinylene carbonate (VC), or a combination thereof;
  • An oxidative decomposition type additive comprising a compound represented by the following Chemical Formula 1, a compound represented by the following Chemical Formula 2, or a mixture thereof;
  • an additive including a semi-ungung additive, which is a compound containing a silyl group, to provide an electrolyte additive for a lithium secondary battery.
  • the weight ratio of the reduction decomposition additive: oxidative decomposition additive may be 5: 2 to 12: 0.05
  • the weight ratio of the reduction decomposition additive: semi-ungsung additive may be 5: 5 to 12: 0.1 have.
  • the reductively degradable additives include fluoroethylene carbonate (FEC) and vinylene carbonate (VC). It has a lower LUMO (Lowest Unoccupied Molecular Orbital) energy than the organic solvent used, and thus has a relatively high tendency to reduce decomposition.
  • FEC fluoroethylene carbonate
  • VC vinylene carbonate
  • the reduction decomposition additive may be reduced decomposition before the organic solvent in the electrolyte when the lithium secondary battery is driven, thereby forming a stable protective film and a polymer protective film based on lithium fluoride (LiF) on the surface of the negative electrode. .
  • the oxidative decomposition type additive is at least one or more of the above-mentioned material
  • it may be one or more of the materials shown in FIG. 2, but as described above, it generally has a relatively low Occupied Molecular Orbital (HOMO) energy than the lithium salt used in the electrolyte,
  • HOMO Occupied Molecular Orbital
  • the lithium secondary battery When the lithium secondary battery is driven, it is oxidized and decomposed before the lithium salt in the electrolyte, and a material capable of forming a stable protective film on the surface of the positive electrode.
  • the reduction decomposition additive and the oxidative decomposition additive may be reduced or oxidatively decomposed before the organic solvent or the lithium salt in the electrolyte to form a solid electrolyte interface (SEI) on the surface of each electrode.
  • SEI solid electrolyte interface
  • the solid electrolyte interface (SEI) formed on the surface of each of the formed electrodes performs a function of stably protecting each of the electrodes without acting as a resistance of the battery. Direct contact with the surface of each electrode can be prevented.
  • the semi-ungpung additive may include a silyl group as described above, it is possible to cause the silyl group to remove the moisture in the electrolyte.
  • the water removal function it is possible to generally suppress the hydrolysis of lithium salts in the electrolyte. Not only this, even if lithium salt in the domestic electrolyte is hydrolyzed to produce an acidic substance (for example, HF, etc.), the acidic substance is formed by the oxidative decomposition product of the semi-finished additive and neutralization reaction of the acidic substance. May be optionally removed.
  • the semiunghyeong additive also has the side effect of forming a stable film on the surface of the positive electrode together with the oxidative decomposition type additive.
  • the semi-heung type additive is not particularly limited as long as it is a compound containing a silyl group, but it is tris (trimethylsilyl) phosphite
  • T-TMSA Trimethylsilyl pho sphite
  • T-TMSM Tris (trimethylsilyl) methane (tris ylsilyl) metane
  • T-TMSM bis (trimethylsilyl) methane (Bis (trimethylsilyl) metliane, B-BMSM)
  • Trimethylsilyl amine T-TMSA
  • B is (trimethylsilyl) amine
  • B-TMSA bis (trimethylsilyl) sulfide bis (trimethylsilyl) sulfide Bis (tmnethylsilyl sulfide, B-TMSSi), bis (trimetylsiloxy) ethane (B-TMSE), bis (trimethylsilylthio) ethane (B-TMSSE), trimethylsilyl eye
  • TMS ITC Trimethylsilyl isotl iocyanate
  • TMS IC Trimethylsilyl isocyanate
  • TMS IC Trimethyl
  • each of the additives described above namely (1) oxidatively degradable additives alone, and (2) three types of additives: reductively degradable additives, oxidatively degradable additives, and semi-ung additives It proposes a method for producing a functional additive consisting of.
  • the oxidatively degradable additive alone may be prepared by reacting the compound represented by the following Chemical Formula 3 and a boron raw material.
  • Ri and R 2 are each independently hydrogen, a substituted or unsubstituted C1 to C8 alkyl group, a substituted or unsubstituted C1 to C8 perfluoro alkyl group, a substituted or unsubstituted C6 to C30 arene (arene) group, substituted or unsubstituted C6 to C30 perfluoro arene (arene) group, CF 3 , halogen element (F, CI, Br, or I), or a combination thereof.
  • A is lithium, sodium, or hydrogen.
  • the boron raw material may be a compound represented by the following Chemical Formula 4, lithium tetrafluoroborate (LiBF 4 ), or a combination thereof.
  • R 3 and R 4 are each independently hydrogen, a substituted or unsubstituted C1 to C8 alkyl group, a substituted or unsubstituted C1 to C8 perfluoro alkyl group, a substituted or unsubstituted C6 to C30 arene (arene) group, substituted or unsubstituted C6 to C30 perfluoro arene (arene) group, CF 3 , halogen element (F, CI, Br, or I), or a combination thereof.
  • X is a halogen element (F, CI, Br, or I), or a combination thereof.
  • the step of preparing the oxidative decomposition type additive is, in the temperature range of 0 to 150 ° C, carbonate-based, ester-based, ether-based, ketone-based, alcohol-based, aprotic solvent, or a combination thereof Using a solvent, it may be carried out wet, and the running time may be greater than 0 hours and up to 24 hours.
  • the oxidative decomposition type additive is reacted by reacting boron trifluorolide (BF 3 , BF 3 -OEt 2 ) or lithium tetrafluoroborate (LiBF 4 ) with the compound represented by Formula 4 above.
  • carbonate solvents such as EC, DMC, EMC, PC, and organic solvents such as diethyl ether, pentane, and hexane may be used as the reaction solvent.
  • a compound represented by the following formula (1), a compound represented by the following formula (2), or a combination thereof may be prepared.
  • the functional additive may be prepared by preparing an oxidative decomposition type additive as described above, and then mixing it with a reduction decomposition type additive and a reactive type additive.
  • preparing a oxidative decomposition type additive by reacting a compound represented by the following Chemical Formula 4 and a boron raw material; And mixing the oxidative decomposition type additive, the reduction decomposition type additive and the reaction type additive, and a method of manufacturing an electrolyte for a lithium secondary battery.
  • R 2 are each independently hydrogen, a substituted or unsubstituted C1 to C8 alkyl group, a substituted or unsubstituted C1 to C8 perfluoro alkyl group, a substituted or unsubstituted C6 to C30 arene group, Substituted or unsubstituted C6 to C30 perfluoro arene (arene) groups, CF 3 , halogen elements (F, CI, Br, or 1), or a combination thereof.
  • A is lithium, sodium, or hydrogen.
  • the step of producing the oxidative decomposition type additive by reacting with the compound represented by 4 is as described above, and the detailed description thereof is omitted.
  • the oxidative decomposition type additive prepared by the sing-base may simply be mixed with the reduction decomposition type additive and the semi-ung additive.
  • each of the additives described above namely (1) oxidatively degradable additives alone, and (2) three types of additives: reductively degradable additives, oxidatively degradable additives, and semi-ung additives It proposes an electrolyte comprising a functional additive consisting of.
  • each of the functional additives may be added to a basic electrolyte containing an organic solvent and a lithium salt.
  • an organic solvent First lithium salt; And an additive; wherein the additive is an oxidative decomposition type additive including a compound represented by the following Chemical Formula 1, a compound represented by the following Chemical Formula 2, or a combination thereof, and provides an electrolyte for a lithium secondary battery.
  • the additive is an oxidative decomposition type additive including a compound represented by the following Chemical Formula 1, a compound represented by the following Chemical Formula 2, or a combination thereof, and provides an electrolyte for a lithium secondary battery.
  • a functional additive consisting of three additives of the reduction decomposition additive, the oxidative decomposition additive, and the reactive additive It provides a lithium secondary electrolyte.
  • the functional additive can be used to be 5 to 19% by weight relative to 100% by weight of the total weight of the electrolyte.
  • the additive total weight to 100% by weight increases, the reduction decomposable additive containing from 5 to 12 parts by weight 0/0, wherein the decomposable oxide additive
  • the reactive additive may be included as 0.1 to 5% by weight.
  • the content of the three additives in the functional additives is limited to the above ranges, respectively, so as to effectively express the respective functions.
  • the lithium salt in the electrolyte may be a crab 1 lithium salt
  • the first lithium salt is lithium hexafluorophosphate (Lithium hexafluorophosphate, LiPF 6 ), lithium tetrafluoroborate (Lithium tetrafluoroborate, LiBF 4 ), lithium perchlorate (Lithium perchlorate, LiC10 4 ), Lithium exafluoro arsenate (LiAsF 6 ), Lithium bis (oxalato) borate (LiBOB), Lithium bisfluorofluorofonimide (Lithium bis (fluorosulfonyl) imide, LiFSI) and lithium fluorooxalateborate (Lithium fluoro (oxalate) borate, LiFOB) may be at least one or more selected from.
  • lithium hexafluorophosphate LiPF 6
  • LiPF 6 lithium hexafluorophosphate
  • the concentration of the 1-lithium salt in the electrolyte may be 0.1 to 2 M, in this range the electrolyte may have an appropriate conductivity and viscosity, it is possible to effectively move the lithium ions.
  • the organic solvent is not particularly limited as long as it is an organic solvent generally used in an electrolyte for a lithium secondary battery.
  • the organic solvent may be a carbonate-based, ester-based, ether-based, ketone-based, alcohol-based, aprotic solvent, or a combination thereof. Can be everyday.
  • the carbonate-based organic solvent may be dimethyl carbonate (dimethyl carbonate, DMC), diethyl carbonate (DEC), dipropyl carbonate (dipropyl carbonte, DPC), methylpropyl carbonate (methylpropyl carbonate, MPC). ), Ethylpropyl carbonate (EPC), ethylmethyl carbonate (EMC), ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC) One or more may be used.
  • DMC dimethyl carbonate
  • DEC diethyl carbonate
  • DPC dipropyl carbonate
  • DPC methylpropyl carbonate
  • MPC methylpropyl carbonate
  • EPC Ethylpropyl carbonate
  • EMC ethylmethyl carbonate
  • EMC ethylmethyl carbonate
  • EC ethylene carbonate
  • PC propylene carbonate
  • BC butylene carbonate
  • ester organic solvent may be methyl acetate (MA), ethyl acetate (EA), n-propyl acetate (n-propyl acetate, n-PA), 1,1-dimethylethyl acetate ( 1,1-dimethylethyl acetate, DMEA), Methyl propionate (MP), ethyl propionate ( ⁇ ), ⁇ -butyrolacton (GBL), decanolide, valerolactone, Mevalonolactone (mevalon actone), caprolactone (caprolactone) and the like can be used.
  • MA methyl acetate
  • EA ethyl acetate
  • n-PA n-propyl acetate
  • 1,1-dimethylethyl acetate 1,1-dimethylethyl acetate
  • DMEA Methyl propionate
  • MP Methyl propionate
  • ⁇ ⁇ -butyrolacton
  • the ether organic solvent may include dibutyl ether, tetraglyme (tetraethylene glycol dimethyl ether, TEGDME), diglyme (diethylene glycol dimethyl ether, DEGDME), dimethoxy ethane, 2-methyltetra Hydrofuran (2-methyltetrahydroforan), tetrahydrofuran or the like may be used.
  • ketone-based organic solvent cyclohexanone, etc.
  • alcohol solvent ethyl alcohol, isopropyl alcohol, etc.
  • aprotic solvent may be used.
  • Nitrile dimethylformamide dimethyl formamide, DMF
  • R-CN R is a C1 to C10 linear, branched or cyclic hydrocarbon group, and may include a double bond aromatic ring or an ether bond.
  • Amides such as), dioxolanes such as 1,3-dioxolane, and sulfolane, and the like.
  • the organic solvents may be used alone or in combination of one or more, and the mixing ratio when using one or more in combination may be appropriately adjusted according to the desired battery performance, which can be widely understood by those skilled in the art. have.
  • organic solvents that are ethylene carbonate (EC), ethyl methyl carbonate (EMC), dimethyl carbonate (dimethyl catbonate, DMC), diethyl carbonate (DEC), or combinations thereof. Can be used.
  • EC ethylene carbonate
  • EMC ethyl methyl carbonate
  • DMC dimethyl carbonate
  • DEC diethyl carbonate
  • composition of the three additives that make up the functional additives, their respective functions and Specific types of materials are as described above.
  • a mixture of fluoroethylene carbonate (FEC) and vinylene carbonate (VC) is used as the reduction decomposition additive.
  • Tris (trimethylsilyl) phosphite (TMSP) is used as the semi-ungular additive, and lithium difluoro (maloneto) borate (Lithium difluoro (malonato) is used as the oxidatively decomposable additive.
  • JB-HLiB lithium difluoro (fluoromalonato) borate
  • JB-FLiB lysium difluoro (difluoromaloneto) borate
  • Lithium difluoro (difluoromalonato) borate JB-DFLiB was used.
  • each of the additives described above namely (1) oxidatively degradable additives alone, and (2) three types of additives: reductively degradable additives, oxidatively degradable additives, and semi-ung additives It proposes a lithium secondary battery to which the functional additive consisting of.
  • a positive electrode including a lithium-rich positive electrode active material;
  • a negative electrode including a silicon-based negative active material;
  • an electrolyte comprising an organic solvent, a first lithium salt, and an additive;
  • the additive is an oxidative decomposition type including a compound represented by the following Chemical Formula 1, a compound represented by the following Chemical Formula 2, or a combination thereof It provides a lithium secondary battery which is an additive.
  • a positive electrode including a lithium-rich positive electrode active material; A negative electrode including a silicon-based negative active material; And an electrolyte comprising an organic solvent, a crab 1 lithium salt, and an additive, wherein the additive includes a reduction decomposition additive, an oxidative decomposition additive, and a semi-ung additive, wherein the reduction decomposition additive is fluoro.
  • the semi-finished additive provides a secondary battery which is a compound comprising a silyl group:
  • the lithium-rich positive active material may include a compound represented by the following Chemical Formula 5.
  • the silicon-based negative active material may be a combination of graphite and silicon, a material coated with silicon on the surface of the graphite particles, and a material coated with silicon and carbon simultaneously on the surface of the graphite particles.
  • the average charging voltage of each lithium secondary battery may be 4.5 V or more.
  • the positive electrode is a positive electrode current collector and the It may include a positive electrode active material layer formed on the positive electrode current collector.
  • the cathode active material layer may include the lithium-rich cathode active material.
  • the lithium-rich positive electrode active material is a compound containing excess lithium than a generally known layered lithium composite metal compound, and may contribute to expressing a high capacity and a high energy density of a battery.
  • the lithium-rich positive electrode active material may include a compound represented by Formula 5 below.
  • the coating layer may include an oxide of a coating element, a hydroxide of a coating element, an oxyhydroxide of a coating element, an oxycarbonate of a coating element, or a hydroxycarbonate of a coating element.
  • the compounds constituting these coating layers may be amorphous or crystalline.
  • the coating element included in the coating layer Mg, Al, Co, K, Na, Ca, Si, Ti, V, Sn, Ge, Ga, B, As, Zr or a combination thereof may be used.
  • the coating layer forming process may be any method that does not adversely affect the physical properties of the positive electrode active material by using these elements in the compound (for example, any coating method may be used as long as it can be coated by spray coating, immersion method, etc.). Details that will be well understood by those in the field will be omitted.
  • the positive electrode active material layer also includes a binder and / or a conductive material.
  • the binder adheres positively to the positive electrode active material particles, and also serves to adhere the positive electrode active material to the current collector well, and representative examples thereof include polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, and diacetyl cellulose.
  • Polyvinylchloride carboxylated polyvinylchloride, polyvinylfluoride, polymers containing ethylene oxide, polyvinylpyridone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene , Styrene-butadiene rubber, acrylated butadiene rubber, epoxy resin, nylon, etc.
  • the present invention is not limited thereto.
  • the conductive material is used to impart conductivity to the electrode, and any battery can be used as long as it is an electronic conductive material without causing chemical change in the battery.
  • any battery can be used as long as it is an electronic conductive material without causing chemical change in the battery.
  • Metal powder, metal fiber, etc. such as black, carbon fiber, copper, nickel, aluminum, silver, etc. can be used, and 1 type (s) or 1 or more types can be mixed and used for electroconductive materials, such as a polyphenylene derivative.
  • A1 may be used as the current collector, but is not limited thereto.
  • the negative electrode and the positive electrode are each prepared by mixing an active material, a conductive material and a binder in a solvent to prepare an active material composition, and applying the composition to a current collector. Since such an electrode manufacturing method is well known in the art, detailed description thereof will be omitted.
  • As the solvent n-methyl-2-pyrrolidone (n-methyl-2-pyrrolidone, NMP) may be used, but is not limited thereto.
  • the negative electrode may also include a negative electrode current collector and a negative electrode active material layer formed on the negative electrode current collector, as in a general battery.
  • the negative electrode active material layer may include the silicon-based negative electrode active material.
  • the silicon-based negative active material may be a combination of graphite and silicon, a material coated with silicon on the surface of the graphite particles, and black, a material coated with silicon and carbon simultaneously on the surface of the graphite particles, but is not limited thereto. .
  • the negative electrode active material layer may further include a binder and / or a conductive material.
  • the binder adheres well to the negative electrode active material particles, and also adheres the negative electrode active material to the current collector.
  • Examples of the binder include polyvinyl alcohol, carboxymethyl cellulose, and carboxymethyl cell.
  • the conductive material is used to impart conductivity to the electrode, and may be used as long as it is an electronic conductive material without causing chemical change in the battery.
  • natural graphite, artificial graphite, Carbon-based materials such as carbon black, acetylene black, ketjen black, and carbon fiber;
  • Metal materials such as metal powder or metal fibers such as copper, nickel, aluminum and silver;
  • Conductive polymers such as polyphenylene derivatives; Or an electroconductive material containing these mixture can be used.
  • the negative electrode current collector may be copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, Polymeric substrates coated with a conductive metal, or combinations thereof, may be used.
  • the negative electrode and the positive electrode are each prepared by mixing an active material, a binder, and a conductive material in a solvent to prepare an active material composition, and applying the composition to a current collector. Since such an electrode manufacturing method is well known in the art, detailed description thereof will be omitted.
  • the average layer voltage of the lithium secondary battery may be 4.5 V or more. This is a high range of voltage that can be expressed as the positive electrode including the over-lithium positive electrode active material and the negative electrode including the silicon-based negative electrode active material are applied, and can be stably maintained by a functional additive included in the electrolyte. additive
  • composition of the oxidatively decomposable additive or the three additives constituting the functional additive, the respective functions, and the specific material types are as described above.
  • a mixture of fluoroethylene carbonate (FEC) and vinylene carbonate (VC) is used, and tris (trimethylsilyl) phosphite (TMSP) is used as the semi-additive.
  • lithium difluoro (malonate) borate Lithium difluoro (malonato) borate, JB-HLiB
  • lithium difluoro (fluoromalonate) borate Lithium difluoro (fluoromalonato) borate , JB-FLiB
  • lithium difluoro (difluoromalonato) borate JB-DFLiB
  • a reference electrolyte containing only an organic solvent and a first lithium salt was prepared (Preparation Example 1, Comparative Example 1), and JB-HLiB, JB-FLiB, and JB-DFLiB, which are one of oxidative decomposition additives, were added thereto alone. (Example 1), the effect on JB-HLiB, JB-FLiB, and JB-DFLiB alone was confirmed in the positive electrode half cell.
  • the organic solvent is ethylene carbonate (EC), ethyl methyl carbonate (EMC), and dimethyl carbonate (diethyl catbonate, DEC) are 2: 5 : 3 (EC: EMC: DEC).
  • EC ethylene carbonate
  • EMC ethyl methyl carbonate
  • DEC dimethyl carbonate
  • Mixed carbonate-based solvents were prepared in a volume ratio of.
  • lithium hexafluorophosphate Lithium hexafluorophosphate, LiPF 6
  • LiPF 6 lithium hexafluorophosphate
  • lithium malonate JB-HLiB
  • lithium fluoromalonate JB-FLiB
  • lithium difluoromalonate JB-DFLiB
  • BIV OEt 2 is used as a boron raw material
  • This solution was reacted for 24 hours at 70 ° C. to finally obtain an oxidatively decomposable additive (JB-HLiB, JB-FLiB, JB-DFLiB).
  • Example 1 When the oxidative decomposition type additive was added to the reference electrolyte of Preparation Example 1
  • the electrolyte a total weight of about (100 parts by weight 0 /.), wherein the oxidation decomposable additives JB-HLiB, JB-FLiB, JB-DFLiB is contained 1.0 wt. 0/0, the reference electrolyte in Production Example 1 based on The electrolyte was made.
  • Example 1 The electrolyte thus prepared was referred to as Example 1, and is represented as "1.0% JB-HLiB, 1.0% JB-FLiB, 1.0% JB-DFLiB" for convenience in FIG. 3.
  • Liu7Nio.nMno.5Coo.nO2 is used as the overlithium cathode active material, Increased with a binder (PVDF) and a conductive material (Super P) such that the ratio 80:10:10 (base sequence, the positive electrode active material: conductive material: binder) n- methyl-2-pyrrolidone avoid (n-methyl- 2 -pyrrolidone , NMP) solvent was homogeneously mixed.
  • PVDF binder
  • Super P conductive material
  • the composite including the overlithium positive electrode active material was evenly applied to an aluminum (A1) current collector, pressed in a roll press, and vacuum dried at 110 ° C. vacuum for 2 hours to prepare a negative electrode. At this time, the electrode density was to have 2.5g / cc.
  • the prepared anode was used as a working electrode, and Li metal ⁇ OO ⁇ m) was used as a reference electrode. Between the prepared anode and Li metal, a polyethylene separator was introduced into a battery container, and the electrolyte added with the functional additive. was injected to produce a lithium secondary battery in the form of a 2032 half-cell according to a conventional manufacturing method.
  • the reference electrolyte prepared in Preparation Example 1 was used as the electrolyte of Comparative Example 1.
  • the electrolyte of Comparative Example 1 is represented by convenience- “Ref”.
  • a lithium secondary battery was manufactured in the same manner as in Example 1, except that the electrolyte of Comparative Example 1 was used instead of the electrolyte of Example 1.
  • Evaluation Example 1 Evaluation of Life Characteristics of Each Lithium Secondary Battery of Example 1 and Comparative Example 1
  • each of the lithium secondary batteries was charged to 4.6 V, and constant voltage condition (constant voltage, CV) was applied at 4 ⁇ 6 V after layer discharge, and the stop condition of this condition was 0.05 C.
  • the discharge applied 2.0V constant current conditions.
  • the rate condition of the chemical layer discharge was Ol C-rate.
  • the constant voltage condition (constant voltage, CV) was applied at 4. 6 V after charging, and the stopping condition of this condition was 0.05 C, and the discharge was applied to the 2.0 V constant current condition.
  • the lifetime evaluation layer conductivity condition was 0.5 C-rate and the discharge rate condition was 0.5 C-mte, and the results are shown in FIG. 3.
  • the life characteristics of the lithium secondary battery of Example 1 is a comparative example
  • a reference electrolyte containing only an organic solvent and a first lithium salt was prepared (Preparation Example 1, Comparative Example 1), and JB-HLiB, JB-FLiB, and JB-DFLiB, which are one of oxidative decomposition type additives, were added thereto alone. (Example 2), The effect on the JB-HLiB, JB-FLiB, and JB-DFLiB single substance was confirmed in the negative electrode half-sal.
  • the electrolyte a total weight of about (100 parts by weight 0/0), wherein the oxidation decomposable additives JB-HLiB, JB-FLiB, JB-DFLiB is contained 1.0 wt. 0/0, the reference electrolyte in Production Example 1 based on The electrolyte was made.
  • Example 2 thus prepared electrolyte is Example 2, in Figure 4 for convenience "1.0% JB- HLiB, 1.0% JB-FLiB, 1.0% JB-DFLiB ".
  • the lithium secondary battery was produced using the electrolyte of Example 1.
  • Graphite as an anode active material is used, and a binder (PVDF) increased ratio of 95: 5, such that the (anode active material: binder) n- methyl-2-pyrrolidone to blood-uniform in the (n-2 methyl- pyrrolidone, NMP) solvents Mixed.
  • PVDF binder
  • the composite including the negative electrode graphite active material was evenly applied to a current collector of copper (A1), pressed in a roll press, and vacuum dried at 80 ° C. vacuum for 2 hours to prepare a negative electrode. At this time, the electrode density was to have 1.2g / cc.
  • the prepared negative electrode was used as a working electrode, and Li metal (700 ffli) was used as a reference electrode. Between the prepared negative electrode and Li metal, a polyethylene separator was introduced into a battery container, and the electrolyte to which the functional additive was added was used. Injecting, to produce a lithium secondary battery in the form of a 2032 half-cell according to a conventional manufacturing method.
  • the reference electrolyte prepared in Preparation Example 1 was used as the electrolyte of Comparative Example 1.
  • the electrolyte of Comparative Example 2 is represented as “Ref” for convenience.
  • a lithium secondary battery was manufactured in the same manner as in Example 1, except that the electrolyte of Comparative Example 2 was used instead of the electrolyte of Example 2.
  • each of the lithium secondary batteries was charged to 0.01 V, and after charging, constant voltage condition (constant voltage, CV) was applied at 0.01 V, and the stop condition of this condition was 0.01 C. 1.0V constant current Conditions were applied.
  • the rate condition of the ignition layer discharge was O. l C-rate.
  • the lithium secondary battery When evaluating the shelf life, the lithium secondary battery was charged to 0.01 V at 25 ° C, and after charging, the constant voltage condition (constant voltage, CV) was applied at 0.01 V, and the stop condition of this condition was 0.01 C. 1.0 V constant current conditions were applied.
  • the lifetime evaluation layer conductivity condition was 0.5 C-rate and the discharge rate condition was 0.5 C-rate, and the results are shown in FIG. 4.
  • the oxidative decomposition type additive not only has excellent negative electrode compatibility but also contributes to the formation of the negative electrode film, thereby preventing side reactions on the negative electrode surface and improving the lifespan characteristics of the battery.
  • the JB-FLiB has the best positive / negative compatibility, and the battery life characteristics are improved.
  • a reference electrolyte comprising only an organic solvent and a first lithium salt was prepared (Preparation Example 1), and two or more additives of FEC, VC, JBFLiB, and TMSP were added thereto (Example 3, Comparative Example 3), FEC The effect of additives including VC, JBFLiB, and TMSP was confirmed in the anode half cell.
  • Example 3 When FEC, VC, JBFLiB, and TMSP were added to the reference electrolyte of Preparation Example 1
  • the reduction decomposition additive is fluoroethylene carbonate (fluoro ethylene carbonate, FEC) and vinylene carbonate (VC) are used, and as an oxidative decomposition type additive, lithium difluoro (fluoromalonate) borate obtained in Preparation Example 2 (Lithium) Difluoro (fluoromalonato) borate (JBFLiB) was used, and as the semi-ung additive, tris (trimethylsilyl) phosphite (Tris (trimethylsilyl) phosphite (TMSP)) was used, and these additives were added to the Preparation Example 1 reference electrolyte.
  • FEC fluoroethylene carbonate
  • VC vinylene carbonate
  • the electrolyte a total weight of about (100 parts by weight 0/0), FEC of the reduction decomposable additive containing 5 parts by weight 0/0, VC was 0.5% by weight, JBFLiB of the oxidation decomposable additive 0.5 0/0 is included, the TMSP banung type additive is contained 0.2 0/0, the reference electrolyte in Preparative example 1 was such that an amount of glass.
  • Example 3 For reference, the electrolyte of Example 3 is shown as "UNIST-3" in FIG. 5 for convenience.
  • a lithium secondary battery in the form of a 2032 half-cell was manufactured in the same manner as in Example 1, except that the electrolyte of Example 3 was used instead of the electrolyte of Example 1.
  • a lithium secondary battery was manufactured in the same manner as in Example 3, except that the electrolyte of Comparative Example 3 was used instead of the electrolyte of Example 3.
  • Example 3 For each lithium secondary battery of Example 3 and Comparative Example 3, one chemical composition After charging and discharging, the charging rate was fixed to C / 5, and the discharge rate was changed to C / 5, C / 2, 1C, 3C, 7C, 20C, and C / 5 to evaluate high rate discharge characteristics, respectively. Evaluation was performed for each three cycles for each discharge rate, and FIG. 5 is a graph showing the discharge capacity according to the rate. Referring to FIG. 6, it can be seen that the discharge capacity at a high rate of the lithium secondary battery of Example 3 is significantly improved than that of Comparative Example 3.
  • reduction decomposition additives FEC, VC
  • oxidative decomposition type additive JBFLiB
  • TMSP type additive
  • Comparative Example 4 In the case of using an electrolyte in which an organic solvent and a first lithium salt are added with a reduction decomposition type additive and a semi-ung additive type
  • fluoroethylene carbonate (FEC) and vinylene carbonate (VC) are used as reduction decomposition type additives, and tris (trimethylsilyl) phosphite (Tris (trimethylsilyl) is used as a semi-additive additive. ) phosphite, TMSP) was used.
  • the FEC of the reduction decomposable additive containing 5 parts by weight 0/0, VC is 0.5 0/0, wherein the additive type banung TMSP is included 0.2% by weight, and the reference electrolyte of Preparation Example 1 was to be included as a balance.
  • Comparative Example 4 The electrolyte thus prepared is referred to as Comparative Example 4, and is labeled "Ref" for convenience in FIGS. 6 to 8.
  • the lithium secondary battery was produced using the electrolyte of the comparative example 4.
  • a silicon-based negative electrode active material is a material coated with silicon and carbon on the surface of the graphite particles at the same time, the diameter is 10 to 20. Further, the mixture was uniformly mixed in distilled water (3 ⁇ 40) so that the weight ratio of the binder (SBR-CMC) and the conductive material (Super P) was 96: 1: 3 (base order, negative electrode active material: conductive material: binder).
  • the composite including the silicon-based negative active material was evenly applied to a copper (Cu) current collector, and then vacuum dried for 2 hours in a 110 ° C. vacuum oven to prepare a negative electrode. At this time, the electrode density was to have 1.2 to 1.3 g / CC .
  • the composite including the perlithium cathode active material was evenly applied to an aluminum (A1) current collector, and then pressed in a press, followed by vacuum drying at 110 ° C. vacuum for 2 hours to prepare a negative electrode. At this time, the electrode density was set to have 2.5 g / CC .
  • a polyethylene separator is introduced into a battery container, the electrolyte of Comparative Example 4 is injected, and a lithium secondary battery in the form of a 2032 full-cell according to a conventional manufacturing method. Was produced.
  • the electrolyte a total weight of about (100 parts by weight 0/0), FEC of the reduction decomposable additive containing 5 parts by weight 0/0, VC was 0.5% by weight, JBFLiB of the oxidation decomposable additive 0.2 0/0 , was adjusted to 0.5 and contains 0/0, or 0.7 wt. 0/0, the TMSP banung type additive is contained 0.2 0/0, the reference electrolyte in the Preparation example 1 is an amount of glass.
  • Example 4 in FIGS. 6 to 8 is labeled as "UNIST-3" for convenience, and the oxidative decomposition type additive content is indicated in parentheses (0.2% JB-F, 0.5% JB-F, 0.7%). JB-F).
  • a lithium secondary battery was manufactured in the same manner as in Comparative Example 4, except that the electrolyte of Example 4 was used instead of the electrolyte of Comparative Example 4.
  • Evaluation Example 4 Evaluation of life characteristics of the lithium secondary batteries of Example 4 and Comparative Example 4
  • each lithium secondary battery was layered at 4.55 V, and after charging, a constant voltage condition (constant voltage, CV) was applied at 4. 5 5 V.
  • the stopping condition of this condition was 0.02 C.
  • the discharge was applied to 2.0V constant current conditions.
  • the rate condition of the chemical layer discharge was Ol C-rate.
  • each lithium secondary battery was layered at 4.55V, and after the layering, a constant voltage condition (constant voltage, CV) was applied at 4.55V, and the stop condition of this condition was 0.05 C, and the discharge was applied with a 2.0V constant current condition. .
  • the layer discharge rate condition was 0.2 C-rate.
  • Evaluation Example 5 Evaluation of Silver Silver Self-Discharge Characteristics of Each Lithium Secondary Battery of Example 4 and Comparative Example 4
  • each lithium secondary battery was charged to 4.55 V, and after the layer discharge, a constant voltage condition (constant voltage, CV) was applied at 4.55 V, and the stop condition of this condition was 0.02 C. A 2.0V constant current condition was applied.
  • the rate condition for Mars layer discharge is 0.1 C- rate.
  • layer discharge was performed once more at room temperature. The layer exhibition conditions were performed in the same manner as in the chemical conversion.
  • the open circuit voltage (OCV) of the full cell using the electrolyte solution of Example 1 and Comparative Example 1 was measured. After 20 days of storage at 60 degrees, the discharge was carried out under the conditions of the Mars discharge, and the capacity retention rate was measured.
  • the higher temperature self-discharge characteristics of the lithium secondary battery of Example 4 than that of Comparative Example 4 are expressed by the fact that the oxidative decomposition type additive (JBFLiB) forms a stable film on the surface of the positive electrode, thereby suppressing the dissolution of the transition metal. It is understood.
  • JBFLiB oxidative decomposition type additive
  • Comparative Example 5 In the case of using an electrolyte in which an organic solvent and a first lithium salt were added with a reduction decomposition type additive
  • the reduction decomposition type additive is fluoroethylene Carbonate (fluoroethylene carbonate, FEC) and vinylene carbonate (vinylene carbonate, VC) were used.
  • FEC of the reduction decomposable additive containing 5 parts by weight 0/0, VC is 0.5 0/0, the reference electrolyte in the Preparation Example 1 is an amount of glass .
  • the electrolyte thus prepared is referred to as Comparative Example 5, and is labeled "RFV" for convenience in FIGS. 9 to 10.
  • a lithium secondary battery was produced using the electrolyte of Comparative Example 5.
  • natural graphite was used as the graphite anode active material, and its diameter was 10 to 20. Further, the mixture was uniformly mixed in a middle water (3 ⁇ 40) solvent such that the weight ratio of the binder (SBR-CMC) and the conductive material (Super P) was%: 1: 3 (base order, negative electrode active material: conductive material: binder).
  • the composite including the graphite negative electrode active material was evenly applied to a copper (Cu) current collector, and then vacuum dried for 2 hours at 110 ° C vacuum Aubon to prepare a negative electrode. At this time, the electrode density was to have 1.2 to 1.3 g / cc.
  • LiCo0 2 is used as the positive electrode active material, so that the weight ratio of the binder (PVDF) and the conductive material (Super P) is 96: 2: 2 (base order, positive electrode active material: conductive material: binder) n-methyl- It was homogeneously mixed in a 2- pyridone (n- methyl- 2 -pyrrolidone, NMP) solvent.
  • the composite including the positive electrode active material was evenly applied to an aluminum (A1) current collector, and then pressed in a press, followed by vacuum drying at 1 HTC vacuum Aubon for 2 hours to prepare a negative electrode. At this time, the electrode density was to have 3.0g / cc to 3.5g / cc.
  • a polyethylene separator is introduced into a battery container, the electrolyte of Comparative Example 4 is injected, and a lithium secondary battery in the form of 2032 full-cell according to a conventional manufacturing method. Was produced.
  • Example 5 When TMSP and JBFLiB were added to the electrolyte of Comparative Example 5 (1) Preparation of electrolyte (1.3 M LiPF 6 in 2: 5: 3 (EC: EMC: DEC) vol.%, FEC 5 wt%, VC 0.5 wt%, JBFLiB 0.5 wt%, TMSP 0.2 wt%)
  • Example 5 in FIGS. 9 to 10 is labeled as "UNIST-3" for convenience, and the oxidative degradation additive content is indicated in parentheses (0.7% JB-F).
  • a lithium secondary battery was manufactured in the same manner as in Comparative Example 5, except that the electrolyte of Example 5 was used instead of the electrolyte of Comparative Example 5.
  • each lithium secondary battery was layered to 4.35 V, and after charging, a constant voltage condition (constant voltage, CV) was applied at 4. 3 5 V.
  • the stopping condition of this condition was 0.02 C.
  • the discharge was applied to 2.7V constant current conditions.
  • the rate condition of the chemical layer discharge was Ol C-rate.
  • each lithium secondary battery layered to 4.35V was layered to 4.35V, and after the layered, the constant voltage condition (constant voltage, CV) was applied at 4.35V, the stop condition of this condition was 0.05C, and the discharge was applied to the 2.7V constant current condition. .
  • the layer discharge rate condition was 0.2 C-rate.
  • Example 5 which is higher than Comparative Example 5 can be confirmed.
  • the anodic interfacial stabilization of oxidative decomposition additive JB-FLiB can be confirmed by comparing the evaluation of LCO / Graphite full cell and OLO / SiC full cell. .
  • Comparative Example 6 thus prepared electrolyte is referred to as Comparative Example 6, for convenience in FIG. Marked with "Without additive”.
  • Example 6 Electrolyte Solution to which Semiunghyeong additive TMSP was added to organic solvent and first lithium salt
  • An electrolyte solution was prepared by adding 0 ⁇ 5 % of tris (trimethylsilyl) phosphite (TMSP), which is a semi-ung additive, to the reference electrolyte of Preparation Example 1.
  • TMSP tris (trimethylsilyl) phosphite

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Abstract

La présente invention concerne un additif fonctionnel comprenant un additif dégradable par réduction, un additif dégradable par oxydation, et un additif réactif et son procédé de préparation, un électrolyte comprenant l'additif fonctionnel et son procédé de préparation, et une batterie secondaire au lithium à laquelle l'additif fonctionnel est appliqué.
PCT/KR2017/002942 2017-03-17 2017-03-17 Additif d'électrolyte pour batterie secondaire au lithium et son procédé de préparation, électrolyte comprenant un additif et son procédé de préparation, et batterie secondaire au lithium comprenant un additif WO2018169112A1 (fr)

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PCT/KR2017/002942 WO2018169112A1 (fr) 2017-03-17 2017-03-17 Additif d'électrolyte pour batterie secondaire au lithium et son procédé de préparation, électrolyte comprenant un additif et son procédé de préparation, et batterie secondaire au lithium comprenant un additif

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PCT/KR2017/002942 WO2018169112A1 (fr) 2017-03-17 2017-03-17 Additif d'électrolyte pour batterie secondaire au lithium et son procédé de préparation, électrolyte comprenant un additif et son procédé de préparation, et batterie secondaire au lithium comprenant un additif

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CN111138462A (zh) * 2018-11-05 2020-05-12 江苏国泰超威新材料有限公司 一种2-氟丙二酸二氟硼酸锂的制备方法及其应用
CN111261941A (zh) * 2020-03-30 2020-06-09 山东海容电源材料股份有限公司 高功率锂电池用电解液及其制备方法
CN113540561A (zh) * 2020-04-14 2021-10-22 华为技术有限公司 电解液添加剂、二次电池电解液、二次电池和终端
CN113651839A (zh) * 2021-06-30 2021-11-16 厦门海辰新能源科技有限公司 一种改善锂电池高低温性能的电解液添加剂及其制备方法、电解液及电化学装置
CN114639870A (zh) * 2020-12-15 2022-06-17 张家港市国泰华荣化工新材料有限公司 一种锂离子电池的电解液及锂离子电池

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KR20160149192A (ko) * 2014-05-08 2016-12-27 삼성에스디아이 주식회사 유기전해액 및 상기 전해액을 채용한 리튬전지
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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111138462A (zh) * 2018-11-05 2020-05-12 江苏国泰超威新材料有限公司 一种2-氟丙二酸二氟硼酸锂的制备方法及其应用
CN111138462B (zh) * 2018-11-05 2022-10-21 江苏国泰超威新材料有限公司 一种2-氟丙二酸二氟硼酸锂的制备方法及其应用
CN111261941A (zh) * 2020-03-30 2020-06-09 山东海容电源材料股份有限公司 高功率锂电池用电解液及其制备方法
CN113540561A (zh) * 2020-04-14 2021-10-22 华为技术有限公司 电解液添加剂、二次电池电解液、二次电池和终端
CN114639870A (zh) * 2020-12-15 2022-06-17 张家港市国泰华荣化工新材料有限公司 一种锂离子电池的电解液及锂离子电池
CN114639870B (zh) * 2020-12-15 2023-05-26 张家港市国泰华荣化工新材料有限公司 一种锂离子电池的电解液及锂离子电池
CN113651839A (zh) * 2021-06-30 2021-11-16 厦门海辰新能源科技有限公司 一种改善锂电池高低温性能的电解液添加剂及其制备方法、电解液及电化学装置
CN113651839B (zh) * 2021-06-30 2022-12-13 厦门海辰储能科技股份有限公司 一种改善锂电池高低温性能的电解液添加剂及其制备方法、电解液及电化学装置

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