Classifications

• • 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
  • C07F7/00—Compounds containing elements of Groups 4 or 14 of the Periodic Table
  • C07F7/02—Silicon compounds
  • C07F7/08—Compounds having one or more C—Si linkages
  • C07F7/12—Organo silicon halides
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M10/00—Secondary cells; Manufacture thereof
  • H01M10/05—Accumulators with non-aqueous electrolyte
  • H01M10/052—Li-accumulators
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M10/00—Secondary cells; Manufacture thereof
  • H01M10/05—Accumulators with non-aqueous electrolyte
  • H01M10/056—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
  • H01M4/00—Electrodes
  • H01M4/02—Electrodes composed of, or comprising, active material
  • H01M4/36—Selection of substances as active materials, active masses, active liquids
  • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
  • H01M4/50—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese
  • H01M4/505—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
• • 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
  • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
  • H01M4/52—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron
  • H01M4/525—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
  • Y02E60/10—Energy storage using batteries

Definitions

• the present invention relates to a non-aqueous electrolyte, a non-aqueous electrolyte battery containing the non-aqueous electrolyte, and a compound.
• Non-aqueous electrolyte batteries such as lithium-ion secondary batteries are used in a wide range of applications, such as power sources for mobile phones such as smartphones, small consumer devices such as notebook computers, and vehicle power sources for driving electric vehicles. It has been put to practical use. As means for improving the battery characteristics of non-aqueous electrolyte batteries, many studies have been made in the fields of active materials for positive electrodes and negative electrodes and additives for non-aqueous electrolyte solutions.
• Patent Document 1 discloses a non-aqueous electrolyte that can improve the initial output of a non-aqueous electrolyte secondary battery and the output after a high temperature cycle test by containing a fluorosilane compound in the electrolyte.
• Patent Document 2 describes a non-aqueous electrolyte secondary battery in which a non-aqueous electrolyte contains a halosilane compound having a specific structure, thereby improving the discharge capacity retention rate after a cycle test and suppressing an increase in internal resistance.
• Patent Document 3 discloses a battery including a positive electrode, a negative electrode, and an electrolytic solution, wherein the negative electrode is capable of absorbing and releasing an electrode reactant, and the constituent elements are metal elements and metalloid elements.
• the battery contains a material containing at least one type of material, and the electrolytic solution contains a cyclic carbonate derivative having a halogen atom and an organic silane derivative having a specific structure, thereby improving charge-discharge efficiency. disclosed.
• Lithium-ion secondary batteries that use non-aqueous electrolyte are expected to be stored in a charged state, but not in a fully charged state. In this case, the deterioration of the battery progresses at an accelerated pace, so that gas generation and large capacity deterioration during high-temperature storage are fatal drawbacks.
• Patent Documents 1 and 2 as a means for improving the battery characteristics of non-aqueous electrolyte secondary batteries, various battery characteristics are improved by including a fluorosilane compound or a halosilane compound in the non-aqueous electrolyte. Improvements are being considered.
• the non-aqueous electrolyte secondary batteries using the non-aqueous electrolyte described in Patent Documents 1 and 2 have sufficient room for improvement in the amount of gas generated and capacity reduction during high-temperature charging and storage.
• the non-aqueous electrolytic solution described in Patent Document 3 has sufficient room for improving the quality deterioration of the electrolytic solution during production, handling, and storage.
• the present invention can keep the quality of the electrolyte constant during manufacturing, handling, and storage of the electrolyte, and by using it in a non-aqueous electrolyte secondary battery, suppresses the amount of gas generated during high-temperature charging and storage,
• An object of the present invention is to provide a non-aqueous electrolyte solution that can suppress an increase in resistance or a decrease in capacity, a non-aqueous electrolyte battery using the non-aqueous electrolyte solution, and a compound to be contained in the non-aqueous electrolyte solution.
• the "gas generation amount” means the amount of gas generated by the decomposition of the solvent and additive, which are components of the electrolytic solution, on the electrode.
• the present inventors found that by containing a specific fluorosilane compound in the non-aqueous electrolytic solution, the non-aqueous electrolytic solution during production, handling, and storage of the non-aqueous electrolytic solution
• the quality of non-aqueous electrolyte batteries can be kept constant, and by using it in non-aqueous electrolyte batteries, it is possible to suppress the amount of gas generated, the increase in internal resistance, and the decrease in capacity during high-temperature charging and storage of non-aqueous electrolyte batteries. , completed the present invention.
• a non-aqueous electrolytic solution comprising an electrolyte, a non-aqueous solvent, and a compound represented by general formula (1).
• R 1 , R 2 and R 3 represent a hydrogen atom
• X represents a methyl group or an ethyl group
• Y represents an alkyl group having 3 to 10 carbon atoms.
• a non-aqueous electrolyte battery comprising a positive electrode and a negative electrode capable of absorbing and releasing metal ions, and a non-aqueous electrolyte, wherein the non-aqueous electrolyte is described in any one of [1] to [5].
• a non-aqueous electrolyte battery which is a non-aqueous electrolyte of [7] The non-aqueous electrolyte battery according to [6], wherein the positive electrode contains a positive electrode active material, and the positive electrode active material is a lithium transition metal oxide represented by the following compositional formula (1).
• Li a1 Ni b1 M c1 O 2 (2) (In the composition formula (2), a1, b1 and c1 are 0.80 ⁇ a1 ⁇ 1.10, 0.30 ⁇ b1 ⁇ 0.98, 0.00 ⁇ c1 ⁇ 0.70, and 0.90 ⁇ b1+c1 ⁇ 1.10.M represents at least one element selected from the group consisting of Co, Mn, Al, Mg, Zr, Fe, Ti and Er.) [9] The following compound (A-4) or compound (A-14).
• the quality of the electrolyte can be kept constant during preparation and storage, and by using it in non-aqueous electrolyte batteries, the amount of gas generated during high-temperature charging and storage of non-aqueous electrolyte batteries is suppressed, and internal resistance It is possible to provide a non-aqueous electrolyte, a non-aqueous electrolyte battery, and a compound that can suppress the increase or the decrease in capacity.
• Non-aqueous electrolytic solution contains an electrolyte, a non-aqueous solvent, and a compound represented by general formula (1). Each component will be described below.
• R 1 , R 2 and R 3 represent a hydrogen atom
• X represents a methyl group or an ethyl group
• Y represents an alkyl group having 3 to 10 carbon atoms.
• X is preferably a methyl group.
• alkyl group having 3 to 10 carbon atoms for Y include a chain alkyl group having 3 to 10 carbon atoms and an alkyl group having a cyclic structure having 3 to 10 carbon atoms.
• Examples of chain alkyl groups having 3 to 10 carbon atoms include n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, i-propyl group, methylpropyl group, t-butyl group, methylbutyl group, methylpentyl group, methylhexyl group, methylheptyl group, methyloctyl group, methylnonyl group and the like.
• the position of the branch does not matter.
• alkyl groups having a cyclic structure having 3 to 10 carbon atoms include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, cyclohexylmethyl, and cyclohexylethyl. group, methylcyclohexyl group, dimethylcyclohexyl group, ethylcyclohexyl group, methylcyclohexylmethyl group and the like.
• a part or all of the hydrogen atoms of the alkyl group may be substituted with halogen atoms.
• a halogen atom includes a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, preferably a fluorine atom or a chlorine atom, and more preferably a fluorine atom.
• Alkyl groups in which some or all of the hydrogen atoms are substituted with halogen atoms include, for example, 3-fluoropropyl group, 3,3-difluoropropyl group, 3,3,3-trifluoropropyl group and heptafluoropropyl group. , 3-chloropropyl group, 2-chloro-3,3,3-trifluoropropyl group and the like.
• n-pentyl, n-hexyl, and n-heptyl are preferred from the viewpoint of suitably controlling the density of the film containing the compound represented by formula (1).
• a chain alkyl group having 5 to 8 carbon atoms such as a group, n-octyl group, methylbutyl group, methylpentyl group, methylhexyl group, methylheptyl group; cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclohexylmethyl cyclohexylethyl group, methylcyclohexyl group, dimethylcyclohexyl group, ethylcyclohexyl group, methylcyclohexylmethyl group; is preferred.
• the reaction activity of the compound represented by the general formula (1) is suitably controlled, the film density containing the compound represented by the general formula (1) is suitably controlled, and the increase in internal resistance is suppressed.
• Compounds (A-1) to (A-19) are preferred from the viewpoint of
• the mechanism by which the non-aqueous electrolytic solution of the present invention can suppress the amount of gas generated during high-temperature storage, suppress the increase in internal resistance, and suppress the decrease in capacity after high-temperature storage is not clear, but is considered as follows. be done.
• the compound represented by the general formula (1) has a double bond and a structure in which a fluorine atom is bonded to a Si atom in the molecule. Due to the electron-withdrawing effect of the fluorine atom, the LUMO level of the double bond bound to the Si atom is lowered, and the reaction activity of the compound represented by general formula (1) is increased.
• the compound represented by the general formula (1) is suitably concentrated on the surface of the electrode active material, a film containing the compound represented by the general formula (1) is easily formed. Since X is a methyl group or an ethyl group, the steric hindrance around the double bond bound to the Si atom is relatively small. is particularly small, the reaction activity of the compound represented by the general formula (1) increases, and the formation of a film on the electrode surface is considered to contribute to the suppression of the amount of gas generated.
• the density of the coating formed on the electrode surface is controlled due to the asymmetry of the compound, and the compound represented by the general formula (1) on the surface of the electrode active material
• the density of the coating containing the compound represented by the general formula (1) is particularly suitably controlled from the moderate steric hindrance of the compound represented by the general formula (1).
• the content of the compound represented by the general formula (1) in the non-aqueous electrolyte is usually 0.001% by mass or more, preferably 0.01% by mass or more, more preferably 0.01% by mass or more, relative to the total amount of the non-aqueous electrolyte. is 0.1% by mass or more, more preferably 0.2% by mass or more, and is usually 10% by mass or less, preferably 5.0% by mass or less, more preferably 3.0% by mass or less, and more preferably It is 2.0% by mass or less, more preferably 1.0% by mass or less.
• the content of the compound represented by the general formula (1) is usually 0.001% by mass or more and 10% by mass or less, preferably 0.01% by mass or more and 5.0% by mass, relative to the total amount of the non-aqueous electrolytic solution. mass % or less, more preferably 0.1 mass % or more and 3.0 mass % or less, still more preferably 0.2 mass % or more and 2.0 mass % or less, still more preferably 0.2 mass % or more and 1.0 mass % It is below.
• the concentration of the compound represented by the general formula (1) to the active material on the surface of the electrode active material It is possible to manufacture a battery that proceeds favorably and generates less gas during high-temperature storage.
• the compound represented by the above general formula (1) can be produced by a known method.
• an alkyl Grignard reagent (alkylmagnesium halide) or a vinyl Grignard reagent (vinylmagnesium halide) can be reacted with a chlorosilane compound or an alkoxysilane compound to introduce an alkyl group or vinyl group onto the Si atom.
• the chlorine atom or alkoxy group bonded to the Si atom of the obtained compound can be replaced with a fluorine atom by treating it with hydrogen fluoride, a metal fluoride, boron trifluoride, a boron trifluoride complex, or the like.
• Methods for synthesizing the compound represented by the general formula (1) include a method of reacting an alkyldichlorovinylsilane or an alkyldialkoxyvinylsilane with 1 equivalent of an alkyl Grignard reagent to fluorinate the resulting compound, dialkyldimethoxysilane, A method of fluorinating a compound obtained by reacting 1 equivalent of a vinyl Grignard reagent can be mentioned.
• the following compound (A-4) and compound (A-14) are novel compounds and are another embodiment of the present invention.
• the compound (A-4) and the compound (A-14) By adding the compound (A-4) and the compound (A-14) to the non-aqueous electrolyte, the amount of gas generated during high-temperature charging and storage of the non-aqueous electrolyte battery is suppressed, and the increase in internal resistance is suppressed. Alternatively, a decrease in capacity can be suppressed.
• Methods for producing compound (A-4) and compound (A-14) are not particularly limited, and examples thereof include the production methods described in Examples.
• a lithium salt is preferably used as the electrolyte of the non-aqueous electrolytic solution.
• the lithium salt is not particularly limited, but examples include lithium fluoroborate salts, lithium fluorophosphate salts, lithium tungstate salts, lithium carboxylate salts, lithium sulfonate salts, lithium imide salts, lithium methide salts, lithium oxalate salts, and fluorine-containing organic lithium salts.
• LiBF 4 as a lithium fluoroborate
• LiPF 6 and Li 2 PO 3 as lithium fluorophosphates.
• LiPO2F2 LiFSO3 , CH3SO3Li as lithium sulfonate salts
• LiN ( FSO2 ) 2 LiN( FSO2 ) (CF3SO2), LiN(CF3SO2 ) as lithium imide salts ) 2 , LiN(C 2 F 5 SO 2 ) 2 , lithium cyclic 1,2-perfluoroethanedisulfonylimide, lithium cyclic 1,3-perfluoropropanedisulfonylimide; as the lithium methide salt, LiC(FSO 2 ) 3 , LiC(CF 3 SO 2 ) 3 , LiC(C 2 F 5 SO 2 ) 3 ; lithium oxalate salts such as lithium difluorooxalate borate, lithium bis(oxalate) borate, lithium tetrafluorooxalate phosphate, lithium difluorobis (oxalate) phosphate, lithium tris(oxalate)
• the above electrolytes can be used singly or in combination of two or more at any ratio.
• the combination of two or more electrolytes is not particularly limited, and may be a combination of LiPF6 and LiN( FSO2 ) 2 , a combination of LiPF6 and LiBF4 , a combination of LiPF6 and LiN( CF3SO2 ) 2 , LiBF4 and A combination of LiN(FSO 2 ) 2 , a combination of LiBF 4 , LiPF 6 and LiN(FSO 2 ) 2 and the like are included.
• a combination of LiPF 6 and LiN(FSO 2 ) 2 , a combination of LiPF 6 and LiBF 4 , and a combination of LiBF 4 , LiPF 6 and LiN(FSO 2 ) 2 are preferred.
• the total concentration of the electrolyte is not particularly limited, but from the viewpoint of proper electrical conductivity and sufficient output characteristics, it is usually 8% by mass or more, preferably 8% by mass or more, based on the total amount of the non-aqueous electrolyte. It is 8.5% by mass or more, more preferably 9% by mass or more, and is usually 18% by mass or less, preferably 17% by mass or less, more preferably 16% by mass or less.
• the total concentration of the electrolyte is usually 8% by mass or more and 18% by mass or less, preferably 8.5% by mass or more and 17% by mass or less, more preferably 9% by mass or more and 16% by mass or less, relative to the total amount of the non-aqueous electrolyte solution.
• the electrolyte compound corresponding to the auxiliary agent When the electrolyte compound corresponding to the auxiliary agent] is contained in the non-aqueous electrolytic solution, it must contain an electrolyte other than the lithium salt corresponding to the auxiliary agent. Moreover, when the content of the electrolyte compound is 5.0% by mass or less, it is classified as an "auxiliary agent" in the present specification.
• the amount of the "electrolyte” includes It does not include the amount of "compounds that Identification of the electrolyte and measurement of the content are performed by nuclear magnetic resonance (NMR) spectroscopy.
• the non-aqueous electrolytic solution according to the present invention usually contains, as its main component, a non-aqueous solvent that dissolves the above-described electrolyte, as with general non-aqueous electrolytic solutions.
• the non-aqueous solvent is not particularly limited, and known organic solvents can be used.
• organic solvents include saturated cyclic carbonates such as ethylene carbonate, propylene carbonate and butylene carbonate; chain carbonates such as dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate; carboxylic acid esters; ether compounds such as dimethoxymethane, diethoxymethane, ethoxymethoxymethane, tetrahydrofuran, 1,3-dioxane, and 1,4-dioxane; 2-methylsulfolane, 3-methylsulfolane, 2-fluorosulfolane, sulfone compounds such as 3-fluorosulfolane, dimethylsulfone, ethylmethylsulfone, and monofluoromethylmethylsulfone; and the like.
• saturated cyclic carbonates, chain carbonates and carboxylic acid esters are preferred, and saturated cyclic carbonates and chain carbonates are more preferred.
• the non-aqueous electrolytic solution according to the present invention may contain various auxiliary agents within a range that does not impair the effects of the present invention.
• auxiliary agent any conventionally known one can be used.
• an auxiliary agent can be used individually by 1 type or in combination of 2 or more types by arbitrary ratios.
• a specific anion-containing compound oxalate complex anion-containing compounds
• carbonate compound selected from a cyclic carbonate having a carbon-carbon unsaturated bond and a fluorine-containing cyclic carbonate hereinafter also referred to as a "specific carbonate compound
• the content of the auxiliary agent is not particularly limited, and is arbitrary as long as it does not significantly impair the effects of the present invention. , More preferably 0.1% by mass or more, and usually 10% by mass or less, preferably 5% by mass or less, more preferably 3% by mass or less, still more preferably 1% by mass or less, particularly preferably 1% by mass is less than
• the content of the auxiliary agent is usually 0.001% by mass or more and 10% by mass or less, preferably 0.01% by mass or more and 5% by mass or less, more preferably 0.1% by mass, relative to the total amount of the non-aqueous electrolyte. % or more and 3 mass % or less, more preferably 0.1 mass % or more and 1 mass % or less, and particularly preferably 0.1 mass % or more and less than 1 mass %.
• the cyclic ether compound can also be used as an auxiliary agent in the non-aqueous electrolytic solution, and [1-3.
• Non-aqueous solvent includes those that can also be used as non-aqueous solvents.
• the cyclic ether compound is used as an auxiliary agent, it is preferably used in an amount of less than 4% by mass relative to the total amount of the non-aqueous electrolytic solution.
• the borate anion-containing compound, the oxalate complex anion-containing compound, the monofluorophosphate anion-containing compound, and the difluorophosphate anion-containing compound can also be used as auxiliary agents in the non-aqueous electrolytic solution, and [1-2. Electrolytes], those that can be used as electrolytes are also included. When these compounds are used as auxiliary agents, they are preferably used in an amount of less than 3% by mass relative to the total amount of the non-aqueous electrolytic solution.
• Said specific anion-containing compound is usually an acid or a salt.
• the specific anion-containing compound is preferably a salt, and the counter cation is preferably an alkali metal cation such as lithium, sodium or potassium, more preferably a lithium cation.
• the method of adding a specific anion-containing compound to the non-aqueous electrolytic solution is not particularly limited, but includes a method of adding a salt of a specific anion-containing compound, such as lithium salt, sodium salt, and potassium salt of a specific anion-containing compound.
• a method of adding one or more selected from is preferable, and a method of adding a lithium salt of a specific anion-containing compound is more preferable.
• a method of adding a raw material of a specific anion-containing compound to the electrolytic solution to generate the specific anion-containing compound in the electrolytic solution is also preferred.
• a method of adding one or more selected from lithium monofluorophosphate, lithium difluorophosphate, sodium monofluorophosphate, sodium difluorophosphate, potassium monofluorophosphate, and potassium difluorophosphate is preferable, A method of adding one or more selected from lithium monofluorophosphate and lithium difluorophosphate is more preferable.
• compounds containing fluorosulfonate anions, fluorosulfonylimide anions, and alkyl sulfate anions are preferred from the viewpoint of the balance between battery output characteristics and electrode interface protection, and compounds containing fluorosulfonate anions and fluorosulfonylimide anions are preferred. is more preferred, and a fluorosulfonate anion is even more preferred.
• the oxalate complex anion-containing compound is not particularly limited as long as it is a compound containing an anion having an oxalate complex in its molecule.
• the oxalate complex anion-containing compound is a compound containing an anion of an acid that forms a complex by oxalic acid being coordinated or bonded to the central atom.
• oxalate is coordinated or bonded to the boron atom.
• Compounds containing a boron oxalate complex anion and a phosphorus oxalate complex anion in which oxalic acid is coordinated or bound to a phosphorus atom can be mentioned.
• Boron oxalate complex anions include bis(oxalate) borate anions, difluorooxalate borate anions, and the like.
• Phosphorus oxalate complex anions include tetrafluorooxalate phosphate anions, difluorobis(oxalate) phosphate anions, tris(oxalate ) and phosphate anions.
• compounds containing a boron oxalate complex anion are preferable, and compounds containing a bis(oxalate)borate anion are more preferable, from the viewpoint of forming a stable composite film on the surface of the electrode.
• the method of adding the oxalate complex anion-containing compound to the electrolytic solution is not particularly limited.
• a method of adding one or more selected from lithium bis(oxalate)borate, lithium difluorooxalateborate, lithium tetrafluorooxalate phosphate, lithium difluorobis(oxalate)phosphate, and lithium tris(oxalate)phosphate is more preferable.
• a method of adding a raw material for the oxalate complex anion-containing compound to the electrolytic solution and generating the oxalate complex anion-containing compound in the electrolytic solution is also preferred.
• the content of the specific anion-containing compound in the total amount of the non-aqueous electrolyte is preferably 0.001 mass % or more, more preferably 0.01% by mass or more, still more preferably 0.1% by mass or more, and preferably 5% by mass or less, more preferably 4% by mass or less, and still more preferably 3% by mass or less. be.
• the content of the specific anion-containing compound in the total amount of the non-aqueous electrolytic solution is preferably 0.001% by mass or more and 5% by mass or less, more preferably 0.01% by mass or more and 4% by mass or less, and even more preferably It is 0.1 mass % or more and 3 mass % or less. If the content of the specific anion-containing compound is within the above range, the battery characteristics, particularly the DCR retention rate after high-temperature storage can be significantly improved, and the amount of gas generated after high-temperature storage can be significantly suppressed. Although the reason for this is not clear, it is believed that the content of the specific anion-containing compound within the above mass ratio range minimizes the side reactions of the components of the non-aqueous electrolytic solution on the electrode surface. Identification and content determination of specific anion-containing compounds are performed by nuclear magnetic resonance (NMR) spectroscopy.
• NMR nuclear magnetic resonance
• Mass ratio of specific anion-containing compound to compound represented by general formula (1) Mass ratio of the content of the specific anion-containing compound (the total amount when there are two or more) to the content of the compound represented by the general formula (1) (specific anion-containing compound [g] / general formula (1 ) is usually 0.01 or more, preferably 0.05 or more, more preferably 0.3 or more, and still more preferably 0, from the viewpoint of suppressing gas generation during high-temperature charging and storage. .7 or more, and usually 100 or less, preferably 10 or less, more preferably 8 or less, and still more preferably 3 or less.
• the mass ratio is usually 0.01 to 100, preferably 0.05 to 10, more preferably 0.3 to 8, even more preferably 0.7 to 8, particularly preferably 0.7. 3 or less.
• the mass ratio is within the above range, the battery characteristics, especially the DCR retention rate after high temperature storage can be significantly improved, and the amount of gas generated after high temperature storage can be significantly suppressed.
• the reason for this is not clear, by containing the compound represented by the general formula (1) and the specific anion-containing compound within the range of the above mass ratio, the components of the non-aqueous electrolytic solution on the electrode surface This is probably because side reactions can be minimized.
• the mass ratio of the content of the specific anion-containing compound (the total amount if two or more types) to the content of the electrolyte (the specific anion-containing compound [g ]/electrolyte [g]) is usually 0.00005 or more, preferably 0.001 or more, more preferably 0.005 or more, still more preferably 0.01 or more, still more preferably 0.015 or more, and It is usually 0.5 or less, preferably 0.45 or less, more preferably 0.4 or less, still more preferably 0.35 or less.
• the mass ratio is usually 0.00005 or more and 0.5 or less, preferably 0.001 or more and 0.45 or less, more preferably 0.005 or more and 0.4 or less, still more preferably 0.01 or more and 0.35 or less. Below, it is more preferably 0.015 or more and 0.35 or less.
• the mass ratio is within the above range, the battery characteristics, particularly the DCR retention rate after high-temperature storage can be significantly improved, and the amount of gas generated after high-temperature storage can be significantly suppressed. Although the reason for this is not clear, it is believed that side reactions of the electrolyte in the battery system can be minimized by containing the specific anion-containing compound and the electrolyte within the above mass ratio range.
• the non-aqueous electrolytic solution preferably contains at least one carbonate compound selected from the group consisting of cyclic carbonates having a carbon-carbon unsaturated bond and cyclic carbonates having a fluorine atom. Among these, it preferably contains a cyclic carbonate having a carbon-carbon unsaturated bond, and more preferably contains vinylene carbonate. These can be used singly or in combination of two or more in any ratio, preferably in combination with unsaturated cyclic carbonate and fluorinated cyclic carbonate, and in combination with vinylene carbonate and fluorinated cyclic carbonate. A combination of saturated cyclic carbonate and monofluoroethylene carbonate is more preferred, and a combination of vinylene carbonate and monofluoroethylene carbonate is even more preferred.
• the content of the specific carbonate compound in the total amount of the non-aqueous electrolyte (the total amount when two or more types are used) is usually 0.001% by mass or more, preferably 0.01% by mass or more, more preferably 0.1% by mass. % or more, more preferably 0.5 mass % or more, and usually 10 mass % or less, preferably 6 mass % or less, more preferably 5 mass % or less, still more preferably 4 mass % or less.
• the content of the specific carbonate compound in the total amount of the non-aqueous electrolyte is usually 0.001% by mass or more and 10% by mass or less, preferably 0.01% by mass or more and 6% by mass or less, more preferably 0.1% by mass.
• Mass ratio of specific carbonate compound to compound represented by general formula (1) Mass ratio of the content of the specific carbonate compound (total amount if two or more types) to the content of the compound represented by general formula (1) (specific carbonate compound [g] / general formula (1)
• the represented compound [g]) is usually 0.01 or more, preferably 0.05 or more, more preferably 0.3 or more, still more preferably 0.5 or more, and usually 100 or less, preferably 10 below, more preferably 5 or less, still more preferably 4 or less.
• the mass ratio is usually 0.01 or more and 100 or less, preferably 0.05 or more and 10 or less, more preferably 0.3 or more and 5 or less, and still more preferably 0.5 or more and 4 or less.
• mass ratio is within the above range, battery characteristics, particularly durability, can be improved.
• the reason for this is not clear, but by containing a specific carbonate compound within the range of the above mass ratio, a film is formed on the electrode, and side reactions of the components of the non-aqueous electrolytic solution can be minimized. it is conceivable that.
• the mass ratio of the content of the specific carbonate compound (the total amount in the case of two or more types) to the content of the electrolyte (specific carbonate compound [g]/electrolyte [g]) is usually 0. 00005 or more, preferably 0.001 or more, more preferably 0.01 or more, still more preferably 0.02 or more, still more preferably 0.025 or more, and usually 0.5 or less, preferably 0.45 or less , more preferably 0.4 or less, and still more preferably 0.35 or less.
• the mass ratio is usually 0.00005 or more and 0.5 or less, preferably 0.001 or more and 0.45 or less, more preferably 0.01 or more and 0.4 or less, and still more preferably 0.02 or more and 0.35. Below, it is more preferably 0.025 or more and 0.35 or less. If the mass ratio is within the above range, battery characteristics, particularly durability, can be improved. The reason for this is not clear, but by containing the carbonate compound and the electrolyte within the above mass ratio range, a film is formed on the electrode, and side reactions of the electrolyte in the battery system are minimized. it is conceivable that.
• Cyclic carbonate having a carbon-carbon unsaturated bond The cyclic carbonate having a carbon-carbon unsaturated bond (hereinafter also referred to as "unsaturated cyclic carbonate”) is not particularly limited as long as it is a cyclic carbonate having a carbon-carbon double bond or a carbon-carbon triple bond. A cyclic carbonate having an aromatic ring is also included in the unsaturated cyclic carbonate.
• unsaturated cyclic carbonates examples include vinylene carbonates, ethylene carbonates substituted with a substituent having an aromatic ring, carbon-carbon double bond or carbon-carbon triple bond, phenyl carbonates, vinyl carbonates, allyl carbonates, catechol carbonates and the like.
• vinylene carbonates and ethylene carbonates substituted with a substituent having an aromatic ring or a carbon-carbon double bond or a carbon-carbon triple bond are preferred.
• Vinylene carbonates include vinylene carbonate, methylvinylene carbonate, 4,5-dimethylvinylene carbonate, phenylvinylene carbonate, 4,5-diphenylvinylene carbonate, vinylvinylene carbonate, 4,5-vinylvinylene carbonate, allylvinylene carbonate, 4 , 5-diallyl vinylene carbonate and the like.
• Ethylene carbonates substituted with a substituent having an aromatic ring or a carbon-carbon double bond or carbon-carbon triple bond include vinylethylene carbonate, 4,5-divinylethylene carbonate, and 4-methyl-5-vinylethylene carbonate.
• vinylene carbonate, vinylethylene carbonate, and ethynylethylene carbonate are preferred because they form a more stable composite coating on the electrode, and more preferably one or more selected from vinylene carbonate and vinylethylene carbonate, and vinylene carbonate is even more preferred.
• An unsaturated cyclic carbonate can be used individually by 1 type or in combination of 2 or more types by arbitrary ratios.
• the cyclic carbonate having a fluorine atom is not particularly limited as long as it has a cyclic carbonate structure and contains a fluorine atom.
• Examples of the cyclic carbonate having a fluorine atom include fluorinated cyclic carbonates having an alkylene group having 2 to 6 carbon atoms, and derivatives thereof, such as fluorinated ethylene carbonate (fluoroethylene carbonate) and derivatives thereof, and Ethylene carbonate having a fluorine group can be mentioned.
• fluorinated ethylene carbonate include fluorinated ethylene carbonate substituted with an alkyl group (for example, an alkyl group having 1 to 4 carbon atoms). Among these, fluoroethylene carbonate having from 1 to 8 fluorine atoms and derivatives thereof are preferable.
• Fluoroethylene carbonate having 1 to 8 fluorine atoms and derivatives thereof, and ethylene carbonate having a fluorine-containing group include monofluoroethylene carbonate, 4,4-difluoroethylene carbonate, 4,5-difluoroethylene carbonate, 4-fluoro -4-methylethylene carbonate, 4,5-difluoro-4-methylethylene carbonate, 4-fluoro-5-methylethylene carbonate, 4,4-difluoro-5-methylethylene carbonate, 4-(fluoromethyl)-ethylene carbonate , 4-(difluoromethyl)-ethylene carbonate, 4-(trifluoromethyl)-ethylene carbonate, 4-(fluoromethyl)-4-fluoroethylene carbonate, 4-(fluoromethyl)-5-fluoroethylene carbonate, 4- fluoro-4,5-dimethylethylene carbonate, 4,5-difluoro-4,5-dimethylethylene carbonate, 4,4-difluoro-5,5-dimethylethylene carbonate and the like.
• monofluoroethylene carbonate, 4,4-difluoroethylene carbonate, and 4,5-difluoroethylene carbonate are used from the viewpoint of imparting high ionic conductivity to the electrolytic solution and facilitating the formation of a stable interfacial protective film.
• One or more selected are preferable.
• Cyclic carbonates having a fluorine atom can be used singly or in combination of two or more at any ratio.
• Non-aqueous electrolyte battery of the present invention is a non-aqueous electrolyte battery comprising a positive electrode and a negative electrode capable of absorbing and releasing metal ions, and a non-aqueous electrolyte, and is a non-aqueous electrolyte secondary battery.
• a configuration other than the above non-aqueous electrolytic solution will be described below using a lithium ion secondary battery as an example.
• the positive electrode has a positive electrode active material capable of intercalating and deintercalating lithium ions on at least part of the current collector surface.
• the positive electrode active material contains a lithium transition metal compound.
• the positive electrode active material (lithium transition metal oxide) used for the positive electrode is described below.
• a lithium transition metal oxide is a compound having a structure capable of desorbing and inserting lithium ions, and is represented by the following compositional formula (1).
• y is -0.2 ⁇ y ⁇ 0.5, preferably -0.1 ⁇ y ⁇ 0.5
• M 1 is a plurality of elements including at least Ni element and the molar ratio of the Ni element content to the content of all elements contained in M 1 (Ni/M 1 ) is 0.30 or more, preferably 0.40 or more, more preferably 0.5 or more. , and is preferably 1.0 or less, more preferably 0.90 or less.
• the molar ratio (Ni/M 1 ) is 0.30 or more and 1.0 or less, preferably 0.40 or more and 0.90 or less, more preferably 0.5 or more and 0.90 or less. If the molar ratio (Ni/M 1 ) is within this range, the compound represented by the general formula (1) tends to form a film on the positive electrode, suppressing a side reaction between the positive electrode and the non-aqueous electrolyte. , the amount of gas generated after high-temperature storage of the non-aqueous electrolyte battery can be suppressed.
• lithium transition metal oxide represented by the composition formula (1) examples include LiNiO 2 , LiNi 0.85 Co 0.10 Al 0.05 O 2 , LiNi 0.80 Co 0.15 Al 0.05 O2 , LiNi0.3Co0.3Mn0.3O2 , LiNi0.5Co0.2Mn0.3O2 , Li1.05Ni0.5Co0.2Mn0.3O _ _ _ _ _ _ 2 , LiNi0.6Co0.2Mn0.2O2 , LiNi0.8Co0.1Mn0.1O2 , LiNi0.91Co0.06Mn0.03O2 , LiNi0 . _ _ _ _ 91 Co 0.06 Al 0.03 O 2 , LiNi 0.90 Co 0.03 Al 0.07 O 2 , Li 1.00 Ni 0.61 Co 0.20 Mn 0.19 O 2 and the like.
• a lithium-transition metal composite oxide having a layered structure is preferable, and a lithium-transition metal composite oxide represented by the following compositional formula (2) is more preferable.
• M2 represents at least one element selected from the group consisting of Co, Mn, Al, Mg, Zr, Fe, Ti and Er
• a1, b1 and c1 each represent 0. 80 ⁇ a1 ⁇ 1.10, 0.30 ⁇ b1 ⁇ 0.98, 0.00 ⁇ c1 ⁇ 0.70, and 0.90 ⁇ b1+c1 ⁇ 1.10.
• 0.90 ⁇ a1 ⁇ 1.10 and b1+c1 1.
• b1 is preferably 0.40 or more and 0.98 or less, more preferably 0.45 or more and 0.98 or less, and still more preferably 0.50 or more and 0.98 or less.
• a lithium-transition metal composite oxide represented by the following compositional formula (3) is preferable.
• M3 represents at least one element selected from the group consisting of Mn, Al, Mg, Zr, Fe, Ti and Er
• a2, b2, c2 and d2 each represent 0.5. 80 ⁇ a2 ⁇ 1.10, 0.30 ⁇ b2 ⁇ 0.98, 0.01 ⁇ c2 ⁇ 0.70, and 0.01 ⁇ d2 ⁇ 0.60, and 0.90 ⁇ b2+c2+d2 ⁇ 1.10 is.
• b2 is preferably 0.40 or more, more preferably 0.45 or more, and still more preferably 0.50 or more.
• d2 is preferably 0.01 or more, more preferably 0.10 or more.
• Preferred examples of the lithium - transition metal composite oxide represented by the composition formula (3) include LiNi0.90Co0.05Mn0.05O2 , LiNi0.85Co0.10Al0.05O 2 , LiNi0.80Co0.15Al0.05O2 , LiNi0.3Co0.3Mn0.3O2 , LiNi0.5Co0.2Mn0.3O2 , Li1 .
• M1 or M2 contains Mn or Al from the viewpoint of increasing the structural stability of the lithium transition metal oxide and suppressing structural deterioration during repeated charging and discharging.
• M3 preferably contains Mn or Al. It is more preferable to include Identification and content measurement of the positive electrode active material are performed by ICP emission spectroscopy after wet decomposition of the sample.
• the lithium transition metal oxide may contain elements (heterogeneous elements) other than the elements contained in any of the composition formulas (1) to (3).
• a positive electrode active material having a different composition from the positive electrode active material (surface adhering substance) attached to the surface may be used.
• the surface adhering substance include oxides such as aluminum oxide, sulfates such as lithium sulfate, and carbonates such as lithium carbonate.
• These surface-attaching substances can be attached to the surface of the positive electrode active material by, for example, a method of dissolving or suspending them in a solvent, impregnating and adding them to the positive electrode active material, and drying the material.
• the amount of the surface-adhering substance is preferably 1 ⁇ mol/g or more, more preferably 10 ⁇ mol/g or more, and usually 1 mmol/g or less, relative to the positive electrode active material.
• a positive electrode active material having the above-described surface-attached substance attached to its surface is also referred to as a "positive electrode active material.”
• a positive electrode active material can be used individually by 1 type or in combination of 2 or more types by arbitrary ratios.
• a positive electrode using the positive electrode active material can be manufactured by a conventional method. That is, a positive electrode active material, a binder, and, if necessary, a conductive material, a thickening agent, and the like are dry-mixed to form a sheet, which is crimped to a positive electrode current collector, or these materials are mixed with a water-based
• the positive electrode is formed by a coating method of forming a positive electrode active material layer on the current collector by dissolving or dispersing the slurry in a liquid medium such as a solvent or an organic solvent to form a slurry, applying the slurry to the current collector, and drying the slurry.
• the positive electrode active material may be roll-molded to form a sheet electrode, or compression-molded to form a pellet electrode.
• the content of the positive electrode active material in the positive electrode active material layer is usually 80% by mass or more and 99.5% by mass or less.
• a positive electrode active material layer obtained by applying a binder, a conductive material, and the like and drying it is preferably densified by a hand press, a roller press, or the like in order to increase the packing density of the positive electrode active material.
• the density of the positive electrode active material layer present on the current collector is usually 1.5 g/cm 3 or more and 4.5 g/cm 3 or less.
• the type of binder is not particularly limited as long as it is a material that dissolves or disperses in the liquid medium for the slurry.
• fluorine-based resins such as polyvinyl fluoride, polyvinylidene fluoride, and polytetrafluoroethylene
• CN group-containing polymers such as polyacrylonitrile and polyvinylidene cyanide, etc.
• a binder can be used individually by 1 type or in combination of 2 or more types by arbitrary ratios.
• the weight average molecular weight of the resin is arbitrary as long as it does not impair the effects of the present invention, and is usually 10,000 or more and 3,000,000 or less.
• the content of the binder in the positive electrode active material layer is usually 0.1% by mass or more and 80% by mass or less.
• Conductive material Any known conductive material can be used as the conductive material. Specific examples thereof include metal materials such as copper and nickel; graphite such as natural graphite and artificial graphite; carbon black such as acetylene black; carbon-based materials such as amorphous carbon such as needle coke; .
• the conductive material can be used singly or in combination of two or more at any ratio.
• the conductive material is used so as to be contained in the positive electrode active material layer generally in an amount of 0.01% by mass or more and 50% by mass or less.
• the material of the positive electrode current collector is not particularly limited, and any known material can be used. Specific examples include metal materials such as aluminum, stainless steel, nickel plating, titanium, and tantalum, with aluminum being preferred.
• Examples of the shape of the current collector include metal foil, metal cylinder, metal coil, metal plate, metal thin film, expanded metal, punched metal, and foamed metal. Among these, a metal foil or a metal thin film is preferred. Incidentally, the metal thin film may be appropriately formed in a mesh shape.
• the thickness of the current collector is arbitrary, but is usually 1 ⁇ m or more and 1 mm or less.
• the thickness of the positive electrode plate is not particularly limited, but from the viewpoint of high capacity and high output, the thickness of the positive electrode active material layer obtained by subtracting the thickness of the current collector from the thickness of the positive electrode plate is On the other hand, it is usually 10 ⁇ m or more and 500 ⁇ m or less.
• the positive electrode plate may have a surface on which a substance having a composition different from that of the positive electrode plate is attached, and the substance may be the same as the surface-attached substance that may be attached to the surface of the positive electrode active material. is used.
• the negative electrode has a negative electrode active material capable of intercalating and deintercalating lithium ions on at least part of the current collector surface.
• Negative electrode active material The negative electrode active material used for the negative electrode is not particularly limited as long as it can electrochemically occlude and release metal ions. Specific examples include (i) carbonaceous materials, (ii) materials containing metallic elements and/or metalloid elements that can be alloyed with Li, (iii) lithium-containing metal composite oxide materials, and mixtures thereof. mentioned. Among these, (i) carbon-based materials, (ii) materials containing metal elements and/or metalloid elements that can be alloyed with Li, in terms of good cycle characteristics and safety and excellent continuous charging characteristics. and (iv) a mixture of graphite with a material containing metallic and/or semi-metallic elements that can be alloyed with Li. These can be used individually by 1 type or in combination of 2 or more types by arbitrary ratios.
• Carbon-based materials include natural graphite, artificial graphite, amorphous carbon, carbon-coated graphite, graphite-coated graphite, and resin-coated graphite. Among these, natural graphite is preferred. Carbon-based materials can be used singly or in combination of two or more at any ratio. Examples of natural graphite include scale-like graphite, scale-like graphite, and/or graphite particles obtained by subjecting these graphites to a treatment such as spheroidization and densification.
• spherical or ellipsoidal graphite particles subjected to a spheroidizing treatment are preferable from the viewpoint of the packing property or charge/discharge rate characteristics of the particles.
• the average particle size (d50) of the graphite particles is usually 1 ⁇ m or more and 100 ⁇ m or less.
• the carbon-based material as the negative electrode active material preferably satisfies at least one of the characteristics such as physical properties and shape shown in the following (1) to (4), and may satisfy a plurality of items at the same time. more preferred.
• (1) X-Ray Diffraction Parameter The d value (interlayer distance) of the lattice plane (002 plane) determined by X-ray diffraction of the carbon-based material according to the Gakushin method is usually 0.335 nm or more and 0.360 nm or less.
• the crystallite size (Lc) of the carbon-based material determined by X-ray diffraction according to the Gakushin method is 1.0 nm or more.
• the volume-based average particle size of the carbon-based material is the volume-based average particle size (median diameter) determined by a laser diffraction/scattering method, and is usually 1 ⁇ m or more and 100 ⁇ m or less.
• (3) Raman R value and Raman half-value width The Raman R value of a carbon-based material is a value measured using an argon ion laser Raman spectroscopy, and is usually 0.01 or more and 1.5 or less. Also, the Raman half-value width of the carbonaceous material near 1580 cm ⁇ 1 is not particularly limited, but is usually 10 cm ⁇ 1 or more and 100 cm ⁇ 1 or less.
• the BET specific surface area of a carbon-based material is the value of the specific surface area measured using the BET method, and is usually 0.1 m 2 ⁇ g ⁇ 1 or more and 100 m 2 ⁇ g ⁇ 1 or less.
• Two or more carbon-based materials having different properties may be contained in the negative electrode active material.
• the properties referred to here indicate one or more properties selected from the group of X-ray diffraction parameters, volume-based average particle diameter, Raman R value, Raman half-value width, and BET specific surface area. Examples of containing two or more types of carbonaceous materials having different properties include that the volume-based particle size distribution is not symmetrical about the median diameter, and that two or more types of carbonaceous materials having different Raman R values are contained. and different X-ray diffraction parameters.
• any conventionally known material containing a metal element and/or metalloid element that can be alloyed with Li can be used. , Al, As, and Zn.
• the material containing a metal element and/or metalloid element that can be alloyed with Li contains two or more metals, the material may be an alloy material made of an alloy of these metals.
• Materials containing metal elements and/or metalloid elements that can be alloyed with Li include oxides, nitrides, and carbides of metals and/or metalloids. The material may contain two or more metals that can be alloyed with Li.
• Si metal Si
• Si-containing inorganic compounds are collectively referred to as "Si compounds".
• the content of the material containing the metal element and/or metalloid element that can be alloyed with Li is preferably 0.1 to 25% by mass with respect to the total mass of the negative electrode active material.
• the material containing a metal element and/or metalloid element that can be alloyed with Li may already be alloyed with Li during the production of the negative electrode described later, and as the material, a Si compound is used to increase the capacity. is preferable.
• Si compounds examples include SiO x (0 ⁇ x ⁇ 2).
• Metal compounds alloyed with Li include Li y Si (0 ⁇ y ⁇ 4.4), Li 2z SiO 2+z (0 ⁇ z ⁇ 2), and the like.
• Si oxide (SiO x1 , 0 ⁇ x1 ⁇ 2) is preferable in that it has a larger theoretical capacity than graphite. Alkali ions can easily move in and out, making it possible to obtain a high capacity.
• the average particle diameter (d 50 ) of the particles is usually 0.01 ⁇ m or more and 10 ⁇ m or less from the viewpoint of cycle life. be.
• the lithium-containing metal composite oxide material is not particularly limited as long as it can occlude and release lithium ions. Specifically, from the viewpoint of high current density charge-discharge characteristics, a lithium-containing metal composite oxide material containing titanium is preferable, and a composite oxide of lithium and titanium (hereinafter also referred to as "lithium titanium composite oxide") is more preferable. A lithium-titanium composite oxide having a spinel structure is preferable, and more preferable because it greatly reduces the output resistance. Also, lithium and/or titanium in the lithium-titanium composite oxide may be substituted with other metal elements such as at least one element selected from the group consisting of Al, Ga, Cu and Zn.
• Li 4/3 Ti 5/3 O 4 , Li 1 Ti 2 O 4 and Li 4/5 Ti 11/5 O 4 are preferable as the lithium titanium composite oxide.
• Li4/ 3Ti4 / 3Al1 / 3O4 is also preferable as a lithium-titanium composite oxide in which part of lithium and/or titanium is replaced with another element.
• a mixture of a material containing a metal element and/or a metalloid element that can be alloyed with Li and graphite] (iv) a mixture of a material containing a metal element and/or a metalloid element capable of being alloyed with Li and graphite; It may be a mixture in which graphite is mixed in a state of particles independent of each other, or a composite in which a material containing a metal element and/or metalloid element that can be alloyed with Li is present on the surface or inside the graphite particles. It's okay.
• the content ratio of the material containing the metal element and/or metalloid element capable of being alloyed with Li to the total of the material containing the metal element and/or metalloid element capable of being alloyed with Li and the graphite is usually 1 mass% or more 99 % by mass or less.
• the identification and content measurement of the negative electrode active material are carried out by ICP emission spectroscopy after alkali fusion of the sample.
• any known method may be used to manufacture the negative electrode as long as it does not impair the effects of the present invention.
• a binder, a liquid medium such as an aqueous solvent and an organic solvent, and, if necessary, a thickener, a conductive material, a filler, etc. are added to form a slurry, which is applied to the current collector. can be produced by drying and then pressing to form a negative electrode active material layer.
• the content of the negative electrode active material in the negative electrode active material layer is usually 80% by mass or more and 99.5% by mass or less.
• the negative electrode active material layer obtained by applying a binder, a thickener, etc. and drying it is preferably densified by a hand press, a roller press or the like in order to increase the packing density of the negative electrode active material.
• the electrode structure when the negative electrode active material is formed into an electrode is not particularly limited, but the density of the negative electrode active material layer present on the current collector is usually 1 g/cm 3 or more and 2.2 g/cm 3 or less.
• the binder is not particularly limited as long as it is stable with respect to the non-aqueous electrolytic solution and the liquid medium used in electrode production.
• Specific examples thereof include rubber-like polymers such as styrene-butadiene rubber (SBR), isoprene rubber, butadiene rubber, fluororubber, acrylonitrile-butadiene rubber (NBR), ethylene-propylene rubber, polyvinylidene fluoride, polytetrafluoroethylene, Fluorinated polymers such as fluorinated polyvinylidene fluoride, tetrafluoroethylene-ethylene copolymers, and the like are included.
• SBR styrene-butadiene rubber
• NBR acrylonitrile-butadiene rubber
• ethylene-propylene rubber polyvinylidene fluoride
• polytetrafluoroethylene polytetrafluoroethylene
• Fluorinated polymers such as fluorinated polyvinylidene
• the content of the binder with respect to the negative electrode active material is usually 0.1% by mass or more and 20% by mass or less.
• the binder contains a rubber-like polymer represented by SBR as a main component
• the content of the binder with respect to the negative electrode active material is usually 0.1% by mass or more and 5% by mass or less.
• the binder contains a fluorine-based polymer represented by polyvinylidene fluoride as a main component
• the content of the binder with respect to the negative electrode active material is usually 1% by mass or more and 15% by mass or less.
• Thickeners are commonly used to adjust the viscosity of the slurry.
• the thickener is not particularly limited, but specific examples include carboxymethylcellulose and salts thereof, methylcellulose, hydroxymethylcellulose, ethylcellulose, polyvinyl alcohol and the like. These can be used individually by 1 type or in combination of 2 or more types by arbitrary ratios.
• the content of the thickener with respect to the negative electrode active material is usually 0.1% by mass or more and 5% by mass or less.
• the current collector for holding the negative electrode active material any known current collector can be used.
• the current collector for the negative electrode include metal materials such as aluminum, copper, nickel, stainless steel, and nickel-plated steel. Copper is particularly preferable in terms of ease of processing and cost.
• the shape of the current collector of the negative electrode include metal foil, metal cylinder, metal coil, metal plate, metal thin film, expanded metal, punched metal, and foamed metal. Among these, a metal foil or a metal thin film is preferred. Incidentally, the metal thin film may be appropriately formed in a mesh shape.
• the thickness of the current collector is arbitrary, but is usually 1 ⁇ m or more and 1 mm or less.
• the thickness of the negative electrode (negative plate) is designed according to the positive electrode (positive plate) to be used, and is not particularly limited. , usually 15 ⁇ m or more and 300 ⁇ m or less.
• the negative electrode plate may have a surface on which a substance having a composition different from that of the negative electrode active material (surface adhering substance) may be used.
• a substance having a composition different from that of the negative electrode active material surface adhering substance
• the surface adhering substance include oxides such as aluminum oxide, sulfates such as lithium sulfate, and carbonates such as lithium carbonate.
• a separator is usually interposed between the positive electrode and the negative electrode in order to prevent a short circuit.
• the separator is usually impregnated with the non-aqueous electrolytic solution.
• the material and shape of the separator are not particularly limited, and any known material can be employed as long as the effects of the present invention are not impaired.
• Electrode group The electrode group has a laminated structure in which the positive electrode plate and the negative electrode plate are sandwiched between the separators, and a structure in which the positive electrode plate and the negative electrode plate are spirally wound with the separator interposed therebetween. Either is fine.
• the ratio of the volume of the electrode group to the internal volume of the battery (electrode group occupancy) is usually 40% or more and 90% or less.
• Electrode group has the above-described laminated structure
• a structure in which the metal core portions of the electrode layers are bundled and welded to a terminal is preferably used.
• a structure in which a plurality of terminals are provided in an electrode to reduce resistance is also preferably used.
• the electrode group has the wound structure described above, the internal resistance can be reduced by providing a plurality of lead structures for each of the positive electrode and the negative electrode and bundling them around the terminal.
• Protective elements include PTC (Positive Temperature Coefficient) elements that increase resistance as heat is generated due to excessive current, thermal fuses, thermistors, and valves that cut off the current flowing through the circuit due to a sudden increase in battery internal pressure or internal temperature during abnormal heat generation. (current cut-off valve) or the like can be used. It is preferable to select the protective element under the condition that it does not operate under normal high-current use, and it is more preferable to design such that abnormal heat generation and thermal runaway do not occur even without the protective element.
• PTC Physical Temperature Coefficient
• a non-aqueous electrolyte battery is usually configured by housing a non-aqueous electrolyte, a negative electrode, a positive electrode, a separator, etc. according to the present invention in an exterior body (exterior case).
• an exterior body exterior body
• the material of the outer case is not particularly limited as long as it is stable with respect to the non-aqueous electrolytic solution used, but from the viewpoint of weight reduction and cost, metals such as iron, aluminum, and aluminum alloys or laminated films are preferably used. be done. In particular, iron is preferable from the viewpoint of pressure resistance for operating the current cut-off valve.
• Exterior cases using the above metals are those that weld the metals together by laser welding, resistance welding, or ultrasonic welding to form a sealed structure, or that use the above metals via a resin gasket to form a crimped structure. things are mentioned.
• the shape of the exterior case of the non-aqueous electrolyte battery is also arbitrary, and may be cylindrical, rectangular, laminated, coin-shaped, large, or the like.
• GC analysis 100 ⁇ L of sample was dissolved in 1 mL of diethyl ether. The resulting solution was analyzed using a GC analyzer (manufactured by Shimadzu Corporation, trade name: GC-2010) under the following conditions. ⁇ Column: DB-1 (length 30 m, inner diameter 0.32 mm, film thickness 0.25 ⁇ m, manufactured by Agilent Technologies) ⁇ Detector: FID - Temperature: 40°C ⁇ 280°C, increased at 10°C/min. - Purity was obtained from peak area %.
• Example 1-1 [Preparation of positive electrode] 90 parts by mass of lithium-nickel-cobalt-manganese composite oxide (Li 1.0 Ni 0.5 Co 0.2 Mn 0.3 O 2 ) as a positive electrode active material and 7 parts by mass of acetylene black as a conductive material; 3 parts by mass of polyvinylidene fluoride (PVdF) as an adhesive was mixed with a disperser in an N-methylpyrrolidone solvent to form a slurry. This was evenly coated on both sides of an aluminum foil having a thickness of 15 ⁇ m, dried, and then pressed to form a positive electrode.
• PVdF polyvinylidene fluoride
• Reference electrolyte solution 1 was prepared by dissolving 6 at 1.0 mol/L (12.2% by mass; concentration in non-aqueous electrolyte solution).
• a non-aqueous electrolytic solution was prepared by adding Compound 1 in the content shown in Table 1 below and vinylene carbonate (VC) as an auxiliary agent to the reference electrolytic solution 1 so that the content was 2 parts by mass.
• the content of compound 1 and VC is the content when the standard electrolytic solution 1 is 100 parts by mass.
• a battery element was produced by stacking the positive electrode, the negative electrode, and the separator made of polyethylene in the order of negative electrode, separator, and positive electrode. After inserting this battery element into a bag made of a laminate film in which both sides of aluminum (thickness 40 ⁇ m) are coated with a resin layer so that the terminals of the positive electrode and the negative electrode protrude, the non-aqueous electrolyte solution prepared as described above is placed in the bag. It was injected into the inside and vacuum-sealed to fabricate a laminate type non-aqueous electrolyte battery.
• the non-aqueous electrolyte battery was CC-CV charged to 4.30 V at 0.17 C, and then stored at high temperature at 60° C. for 2 weeks. Thereafter, the non-aqueous electrolyte battery was sufficiently cooled, and then discharged to 2.50 V at 0.17 C. The discharge capacity was taken as the "remaining capacity after storage”. Further, after CC-CV charging to 4.20 V at 0.17 C, discharging to 2.50 V at 0.17 C and charging to 3.72 V at 0.17 C stabilize the non-aqueous electrolyte battery. Ta.
• Non-aqueous electrolyte batteries were fabricated in the same manner as in Example 1-1, except that compound 1 was not added to reference electrolyte 1, or compound 3 was added instead of compound 1.
• a non-aqueous electrolyte battery was similarly evaluated.
• Table 1 shows the results.
• the gas amount after storage and the residual capacity after storage of Comparative Example 1-2 are relative values when the gas amount after storage and the residual capacity after storage of Comparative Example 1-1 are set to 100, respectively.
• Example 1-1 containing the compound represented by general formula (1) is compared with Comparative Example 1-1 and Comparative Example 1-2 that do not contain the compound represented by general formula (1). As a result, it can be seen that the generation of gas and the decrease in capacity after high-temperature charging and storage are suppressed.
• Example 2-1 [Preparation of non-aqueous electrolytic solution]
• EC ethylene carbonate
• DMC dimethyl carbonate
• EMC ethyl methyl carbonate
• a reference electrolytic solution 2 was prepared by dissolving 6 at 1.0 mol/L (12.2% by mass; concentration in the non-aqueous electrolytic solution).
• a non-aqueous electrolyte solution was prepared by adding compound 1 to reference electrolyte solution 2 at the content shown in Table 2 below.
• the content of Compound 1 in Table 2 is the content when the standard electrolyte solution 2 is 100 parts by mass.
• Example 2-2 Comparative Example 2-1, Comparative Example 2-2> A non-aqueous electrolytic solution was prepared in the same manner as in Example 2-1, except that compound 2, compound 4, or compound 5 was added instead of compound 1 to reference electrolytic solution 2, and the same as in Example 2-1. Then, the residual amount of the compound in the non-aqueous electrolytic solution was measured. Table 2 shows the results.
• Example 3-1 [Preparation of positive electrode] 90 parts by mass of lithium-nickel-cobalt-manganese composite oxide (Li 1.0 Ni 0.5 Co 0.2 Mn 0.3 O 2 ) as a positive electrode active material and 7 parts by mass of acetylene black as a conductive material; 3 parts by mass of polyvinylidene fluoride (PVdF) as an adhesive was mixed with a disperser in an N-methylpyrrolidone solvent to form a slurry. This was uniformly coated on both sides of an aluminum foil having a thickness of 15 ⁇ m, dried, and then pressed to form a positive electrode.
• PVdF polyvinylidene fluoride
• EC ethylene carbonate
• DMC dimethyl carbonate
• EMC ethyl methyl carbonate
• a reference electrolytic solution 3 was prepared by dissolving 6 at 1.0 mol/L (12.2% by mass; concentration in the non-aqueous electrolytic solution).
• compound 1 was added in the content shown in Table 3 below, and vinylene carbonate (VC) and monofluoroethylene carbonate (FEC) as auxiliary agents were added so that the content was 2 parts by mass.
• VC vinylene carbonate
• FEC monofluoroethylene carbonate
• a non-aqueous electrolyte was prepared.
• the contents of Compound 1, VC, and FEC are the contents when the standard electrolyte solution 3 is 100 parts by mass.
• a battery element was produced by stacking the positive electrode, the negative electrode, and the separator made of polyethylene in the order of negative electrode, separator, and positive electrode. After inserting this battery element into a bag made of a laminate film in which both sides of aluminum (thickness 40 ⁇ m) are coated with a resin layer so that the terminals of the positive electrode and the negative electrode protrude, the non-aqueous electrolytic solution prepared as described above is placed in the bag. It was injected into the inside and vacuum-sealed to fabricate a laminate type non-aqueous electrolyte battery.
• the non-aqueous electrolyte battery prepared by the above method is constant current charged to 3.60 V at a current corresponding to 0.025 C, and then CC-CV charged to 4.20 V at 0.17 C. and then discharged at 0.17C to 2.50V. Subsequently, CC-CV charging was performed at 0.17C to 4.10V. After that, aging was performed by holding at 60° C. for 24 hours. After that, it was discharged to 2.50 V at 0.17 C, further CC-CV charged to 4.20 V at 0.17 C, and then discharged to 2.50 V at 0.17 C.
• the discharge capacity was taken as the initial capacity. . Further initial conditioning was completed by stabilizing the cell by charging to 3.72 V at 0.17C. This was discharged at 0.3C, 0.6C, 0.9C, 1.2C and 1.5C at 25°C for 2 seconds. The average value of the slopes of the obtained current-voltage straight lines at 0.3C, 0.6C, 0.9C, 1.2C and 1.5C was taken as the battery internal resistance.
• the non-aqueous electrolyte battery was CC-CV charged to 4.30 V at 0.17 C, and then stored at high temperature at 60° C. for 2 weeks. After that, the non-aqueous electrolyte battery was sufficiently cooled, discharged at 0.17C to 2.50V, and CC-CV charged at 0.17C to 4.20V. Further, the discharge capacity when the battery was discharged to 2.50 V at 0.17 C was defined as the post-storage recovery capacity. The ratio of the recovered capacity after storage to the initial capacity was defined as the "post-storage capacity retention rate".
• the internal resistance of the battery after the storage test was determined and referred to as "post-storage internal resistance”.
• the "internal resistance increase rate” was calculated from the ratio of the internal resistance after storage and the internal resistance after initial conditioning.
• the stabilized non-aqueous electrolyte battery was immersed in an ethanol bath and the volume was measured, and the amount of generated gas was determined from the volume change before initial conditioning and after the storage test, and this was defined as the "post-storage gas amount”.
• Table 3 shows the gas amount after storage, the internal resistance after storage, the internal resistance increase rate after storage, and the capacity retention rate after storage when each of the gas amount after storage, the internal resistance after storage, the internal resistance increase rate, and the capacity retention rate after storage in Comparative Example 3-1 is 100. Relative values of resistance increase rate and post-storage capacity retention rate are shown.
• Non-aqueous electrolyte batteries were fabricated in the same manner as in Example 3-1, except that compound 2, compound 4, or compound 5 was added instead of compound 1 to reference electrolyte 1, or compound 1 was not added. , the non-aqueous electrolyte battery was evaluated in the same manner as in Example 3-1.
• Table 3 shows the results.
• the gas amount after storage, the internal resistance after storage, the internal resistance increase rate, and the capacity retention rate after storage of Example 3-2, Comparative Example 3-2, and Comparative Example 3-3 are the same as those of Comparative Example 3-1. It is a relative value when the gas amount after storage, the internal resistance after storage, the internal resistance increase rate, and the capacity retention rate after storage are set to 100, respectively.
• the non-aqueous electrolytic solutions of Examples 2-1 and 2-2 containing compounds 1 and 2 represented by general formula (1) are non-aqueous electrolytic solutions of Comparative Example 2-1 containing compound 4. It can be seen that volatilization of the compound is suppressed in the liquid, and the content of the compound in the non-aqueous electrolyte can be kept constant. Further, from Table 3, Examples 3-1 and 3-2 containing compounds 1 and 2 represented by general formula (1) are Comparative Example 3- which does not contain a compound represented by general formula (1) Compared to 1 to 3-3, it can be seen that the gas generation, internal resistance, and internal resistance increase rate after high-temperature charge storage are suppressed, and the decrease in capacity retention rate after storage is suppressed.
• Example 3-2 using compound 2 in which Y is a chain alkyl group markedly suppresses gas generation after high-temperature charging and storage.
• Example 3-1 using compound 1 in which Y is an alkyl group having a cyclic structure has the effect of suppressing gas generation after high-temperature charging and storage and increasing internal resistance. It turns out that it is excellent in the balance of an inhibitory effect. From Tables 2 and 3, compound 1 and compound 2 represented by general formula (1) can keep the quality constant during electrolyte solution preparation and storage.
• Compound 5 which is a comparative compound, can keep the quality of the non-aqueous electrolyte constant during preparation and storage of the non-aqueous electrolyte, even if it is used in a non-aqueous electrolyte battery, gas generation and internal resistance , and the internal resistance increase rate cannot be suppressed.
• Example 4-1 [Preparation of positive electrode] 90 parts by mass of lithium-nickel-cobalt-manganese composite oxide (Li 1.0 Ni 0.8 Co 0.1 Mn 0.1 O 2 ) as a positive electrode active material and 7 parts by mass of acetylene black as a conductive material; 3 parts by mass of polyvinylidene fluoride (PVdF) as an adhesive was mixed with a disperser in an N-methylpyrrolidone solvent to form a slurry. This was evenly coated on both sides of an aluminum foil having a thickness of 15 ⁇ m, dried, and then pressed to form a positive electrode.
• PVdF polyvinylidene fluoride
• EC ethylene carbonate
• DMC dimethyl carbonate
• EMC ethyl methyl carbonate
• a reference electrolytic solution 4 was prepared by dissolving 6 at 1.0 mol/L (12.2% by mass; concentration in the non-aqueous electrolytic solution).
• a non-aqueous electrolyte was prepared by adding Compound 2 to Reference Electrolyte 4 in the amount shown in Table 4 below and vinylene carbonate (VC) as an auxiliary agent in an amount of 1 part by mass.
• the content of compound 2 and VC is the content when the standard electrolytic solution 4 is 100 parts by mass.
• a battery element was produced by stacking the positive electrode, the negative electrode, and the separator made of polyolefin in the order of negative electrode, separator, and positive electrode. After inserting this battery element into a bag made of a laminate film in which both sides of aluminum (thickness 40 ⁇ m) are coated with a resin layer so that the terminals of the positive electrode and the negative electrode protrude, the non-aqueous electrolytic solution prepared as described above is placed in the bag. It was injected into the inside and vacuum-sealed to fabricate a laminate type non-aqueous electrolyte battery.
• the non-aqueous electrolyte battery was CC-CV charged to 4.3 V at 0.2 C, and then stored at high temperature at 60° C. for 2 weeks. After that, the non-aqueous electrolyte battery was sufficiently cooled, discharged at 0.2C, and CC-CV charged at 0.2C to 4.3V. Furthermore, the discharge capacity when discharged at 0.2 C was defined as the post-storage recovery capacity. The ratio of the recovered capacity after storage to the initial capacity was defined as the "post-storage capacity retention rate". Furthermore, the battery was stabilized by CC-CV charging to 3.7V at 0.2C.
• the stabilized non-aqueous electrolyte battery was immersed in an ethanol bath, the volume was measured, and the amount of generated gas was determined from the volume change after the initial conditioning and after the storage test, and this was defined as the "post-storage gas amount”.
• Table 4 below shows the relative values of the post-storage gas amount and the post-storage capacity retention rate when the post-storage gas amount and the post-storage capacity retention rate of Comparative Example 4-1 are set to 100, respectively.
• Example 4-1 a non-aqueous electrolyte battery was produced in the same manner as in Example 4-1, except that Compound 6 or Compound 7 was added in the content shown in Table 4 in addition to Compound 2 to Reference Electrolyte 4.
• Non-aqueous electrolyte batteries of Examples 4-2 to 4-8 were produced in the same manner as in 4-1, and the non-aqueous electrolyte batteries were evaluated in the same manner as in Example 4-1.
• the mass ratio is the mass ratio of the content [g] of the specific anion-containing compound to the content [g] of the compound represented by the general formula (1) in the non-aqueous electrolyte (specific anion Content [g] of contained compound/content [g] of compound represented by general formula (1)).
• non-aqueous electrolyte batteries of Comparative Examples 4-1 to 4-3 were prepared in the same manner as in Example 4-1 except that compound 2 was not added or compound 6 or compound 7 was added instead of compound 2.
• the non-aqueous electrolyte battery was evaluated in the same manner as in Example 4-1.
• Table 4 shows the results.
• the gas amount after storage and the capacity retention rate after storage in Examples 4-2 to 4-8 and Comparative Examples 4-2 to 4-3 are the same as the storage gas amount and capacity retention rate after storage in Comparative Example 4-1. Each is a relative value when set to 100.
• Example 4-1 containing the compound represented by general formula (1) compares with Comparative Example 4-1 that does not contain the compound represented by general formula (1), high temperature charge storage It can be seen that the gas generation is suppressed at the time.
• Examples 4-2 to 4-8 containing a specific anion compound in addition to the compound represented by the general formula (1) contain the compound represented by the general formula (1) and the specific anion compound Compared to Example 4-1, which does not contain, and Comparative Examples 4-2 and 4-3, which do not contain the compound represented by the general formula (1) and contain a specific anion compound, after high-temperature charging and storage It can be seen that the gas generation is remarkably suppressed, and the balance between the effect of suppressing gas generation after high-temperature charging and storage and the effect of suppressing a decrease in capacity retention rate is excellent.
• the non-aqueous electrolyte of the present invention can keep the quality of the non-aqueous electrolyte constant during electrolyte preparation and storage, and by using it in non-aqueous electrolyte batteries, when charging and storing non-aqueous electrolyte batteries at high temperatures It is possible to suppress the amount of gas generated, suppress the increase in internal resistance, or suppress the decrease in remaining capacity. Therefore, the non-aqueous electrolyte battery of the present invention can be suitably used in all fields such as electronic devices in which non-aqueous electrolyte batteries are conventionally used. Moreover, the non-aqueous electrolyte battery of the present invention can be used for various known applications.
• applications include notebook computers, pen-input computers, mobile computers, e-book players, mobile phones, mobile faxes, mobile copiers, mobile printers, mobile audio players, small video cameras, headphone stereos, video movies, and liquid crystals.

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