Nonaqueous electrolyte and energy device using same

Abstract

To provide a non-aqueous electrolyte solution that significantly improves the capacity retention rate, output retention rate, and battery swell during high-temperature storage as compared to conventional techniques.SOLUTION: A non-aqueous electrolyte solution includes a compound represented by a structural formula of P(OR)5 (in the structural formula, each R is an independent hydrocarbon group having 1 to 8 carbon atoms, which may be linear or branched, and may be linked to each other to form a ring structure). Preferably, the content of the compound represented by the structural formula of P(OR)5 is 0.0001 mass% or more and 5 mass% or less with respect to the total amount of the non-aqueous electrolyte solution.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a non-aqueous electrolyte solution and an energy device using the same. [Background technology]

[0002] From consumer power sources for mobile phones, laptops, etc. to on-board power sources for automobiles In a wide range of applications, such as non-aqueous electrolyte secondary batteries and electric double layer capacitors, Energy devices using non-aqueous electrolytes, such as lithium-ion capacitors, have been put to practical use. However, in recent years, there has been an increasing demand for higher performance energy devices. In particular, in non-aqueous electrolyte secondary batteries, the battery characteristics, e.g., cycle characteristics, There is a demand for high standards of durability, storage properties, safety, and other characteristics.

[0003] Until now, the capacity of non-aqueous electrolyte secondary batteries during durability tests such as cycle characteristics and storage characteristics has been As a means to improve battery capacity, battery swelling, cathode metal elution, and safety, Numerous technologies are being investigated for various battery components, including materials and non-aqueous electrolytes. It has been done. For example, Patent Document 1 describes a method for improving the electrolyte by using trialkyl phosphite as an electrolyte. A technology that forms a coating of a phosphorus compound on the surface to improve the cycle characteristics of non-aqueous electrolyte secondary batteries. The technique has been revealed.

[0004] In addition, Patent Document 2 discloses that by using a cyclic carbonate ester and a phosphorous ester, By forming a thermally stable reducing film on the negative electrode, the storage characteristics in a high-temperature environment are improved. A technology has been disclosed. In addition, Non-Patent Document 1 describes how trimethyl phosphite is used as an electrolyte to improve the cycle It has been reported that the battery performance including the characteristics is improved, and Li x PO y Shape It has been suggested that this may be due to the fact that [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2001-243981 A [Patent Document 2] JP 2004-14351 A [Non-Patent Document 1] Electrochimica Acta,52(2),636-642(2006). Summary of the Invention [Problem to be solved by the invention]

[0006] As described above, in recent years, the demand for high performance non-aqueous electrolyte secondary batteries has been increasing. Improvement of the performance of secondary batteries using electrolyte electrolytes, i.e., the capacity during endurance such as cycle operation and storage There is a demand for improved battery capacity retention and reduced battery swelling, which also contributes to improved safety. However, the compounds described in Patent Documents 1 and 2 and Non-Patent Document 1, and In non-aqueous electrolyte batteries using the electrolyte used in this study, the capacity retention rate and output retention rate during durability were improved, and However, it is difficult to say that the suppression of battery swelling is sufficient.

[0007] The reasons for this are not yet fully understood, but they include the following: In other words, it is speculated that phosphite esters are easily electrochemically oxidized on the positive electrode surface. When the film is formed, electrons are released from the phosphite to the positive electrode, which allows the The capacity decreases. In addition, if decomposition due to such oxidation occurs during storage at high temperatures, it can cause gas swelling. This may accelerate battery deterioration during endurance use and reduce battery safety.

[0008] In addition, the by-reaction components during high-temperature storage may become solid substances. In this case, It is assumed that this accumulation inhibits the insertion and desorption reactions of lithium ions into the electrode active material. In other words, it acts as a resistance component for the absorption and release of lithium ions in the positive electrode, lowering the charge and discharge characteristics and This can lead to a decrease in capacity and storage capacity maintenance rate, as well as a decrease in rate characteristics and input / output characteristics. The present invention has been made in view of the above background art, and an object of the present invention is to provide a method for producing a non-aqueous electrolyte secondary battery. The purpose of this study is to improve the durability of energy devices, such as secondary batteries, especially when stored at high temperatures. The present invention provides a non-aqueous electrolyte solution that improves the capacity retention rate and output retention rate of a battery and prevents battery swelling. [Means for solving the problem]

[0009] As a result of intensive research into solving the above problems, the present inventors have discovered a method for producing an electrolyte and a material capable of dissolving the electrolyte. A compound having a structure of P(OR)5 is added to a non-aqueous electrolyte solution containing a non-aqueous solvent. This has significantly improved the capacity retention rate, output retention rate and battery swelling during high-temperature storage compared to conventional technologies. The inventors have found an improvement to this effect, and have completed the present invention. More specifically, the present inventors have investigated the capacity retention rate, output retention rate and battery swelling during high-temperature storage by using the conventional In order to develop a new non-aqueous electrolyte that will significantly improve conventional technology, We have focused on the formation mechanism and elementary reaction rate of the negative electrode film of non-aqueous electrolyte secondary batteries, Various studies were conducted on the effects of these combinations.

[0010] The inventors then added a compound having a structure of P(OR)5 to a non-aqueous electrolyte solution. This novel idea has significantly improved the capacity, output and swelling of the battery during endurance compared to conventional technology. As a result, the previously known structure of P(OR)3 was Compared to phosphite ester, it has improved capacity retention rate, output retention rate and battery swelling during high temperature storage. We have built technology that provides significant improvements over the technology.

[0011] That is, the present invention provides specific embodiments shown in [1] to [6] below. [1] A non-aqueous electrolyte solution containing a compound represented by the structural formula P(OR)5. R is an independent hydrocarbon group having 1 to 8 carbon atoms, and may be linear or branched. They may be linked together to form a ring structure.) [2] The content of the compound represented by the structural formula P(OR)5 is the total content of the nonaqueous electrolyte solution The nonaqueous electrolyte solution according to [1], wherein the amount of the electrolyte is 0.0001% by mass or more and 5% by mass or less.

[0012] [3] The non-aqueous electrolyte solution is an inorganic lithium halide salt, a lithium fluorophosphate salt, or the like. , lithium tungstate salts, lithium carboxylate salts, lithium sulfonate salts, sulfur Lithium acid salts, lithium imide salts, lithium methide salts, lithium oxalate salts and at least one compound selected from the group consisting of fluorine-containing organic lithium salts. The non-aqueous electrolyte solution according to [1] or [2].

[0013] [4] The non-aqueous electrolyte contains LiPF6, and the molar ratio of PF6 to P(OR)5 is [PF6] The nonaqueous electrolytic solution according to any one of [1] to [3], wherein / [P(OR)5] is 2.0 or more and 2500 or less. liquid.

[0014] [5] The non-aqueous electrolyte solution is a saturated cyclic carbonate, a chain carbonate, a chain carboxylic acid Consists of acid esters, cyclic carboxylates, ether compounds and sulfone compounds The present invention relates to a compound according to any one of [1] to [4], which contains at least one compound selected from the group consisting of Non-aqueous electrolyte. [6] The non-aqueous electrolyte solution contains a cyclic carbonate having a carbon-carbon unsaturated bond, fluorine Cyclic carbonates with atoms, fluorinated unsaturated cyclic carbonates, rings with SO2 groups Compounds having cyano groups, isocyanate compounds and carboxylic acid anhydrides Any one of [1] to [5], which contains at least one compound selected from the group consisting of The non-aqueous electrolyte described above.

[0015] [7] A plurality of electrodes capable of absorbing and releasing metal ions, and any one of [1] to [6] An energy device comprising the nonaqueous electrolyte solution according to the present invention. Effect of the Invention

[0016] According to the present invention, the capacity retention rate, output retention rate, and battery swelling during high-temperature storage are significantly improved. To provide a non-aqueous electrolyte that can realize energy devices such as non-aqueous electrolyte secondary batteries. According to a preferred embodiment of the present invention, it is possible to obtain not only the input / output characteristics but also the impedance. It also has excellent cycle characteristics, high-temperature storage characteristics, and continuous charging and discharging characteristics. To provide a non-aqueous electrolyte capable of realizing energy devices with excellent electrical properties and safety. In addition, an energy device using this non-aqueous electrolyte solution can be provided. do.

[0017] Compounds with the structural formula P(OR)5 are more stable than compounds with the structural formula P(OR)3. It has higher oxidation resistance and is less likely to emit electrons to the positive electrode, making it less likely to experience direct capacity loss. In addition, compounds represented by the structural formula P(OR)5 have nucleophilic reaction acceptability and are active on the positive electrode surface. It can react with reactive oxygen atoms to deactivate the active sites, or it can deactivate the reactive oxygen species produced by side reactions. It is possible to trap nuclear compounds, which suppresses further side reactions on the positive electrode surface. The validity of molecular design based on this idea is demonstrated by the P(OR)5 Examples 1 and 2 using a compound represented by the structural formula P(OR)3 This is also clear from the fact that the capacity retention rate, output retention rate, and battery swelling are superior to those of Comparative Example 2, which used a compound. It is clear. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] The following describes in detail the embodiments of the present invention. These are just examples (representative examples) of the embodiment, and the present invention is not limited to these. The present invention can be modified and implemented as desired without departing from the spirit and scope of the present invention.

[0019] <1. Compounds represented by the structural formula P(OR)5> The non-aqueous electrolyte according to one embodiment of the present invention contains a compound represented by the structural formula P(OR)5. Contains. In the structural formula of P(OR)5, each R is independently a hydrocarbon group having 1 to 8 carbon atoms, They may be a chain or a branched chain, or may be linked together to form a ring structure. The hydrocarbon group may be a saturated hydrocarbon group or an unsaturated hydrocarbon group. Examples of saturated hydrocarbon groups include the following structures (* indicates the oxygen atom of P(OR)5). (Indicating the binding site of ).

[0020] [ka]

[0021] R is a saturated hydrocarbon group, which reduces the cost of the final product by using inexpensive alcohol as a raw material. This is preferable because it allows for a reduction in Examples of unsaturated hydrocarbon groups include the following structures (* indicates the oxygen atom of P(OR)5). (Indicates the binding site for .

[0022] [ka]

[0023] In addition, in the compound represented by the structural formula P(OR)5, two or more R are linked together to form a ring structure. When the 3-D structure of P(OR)5 is formed, the three-dimensional structure of P(OR)5 is stabilized and the direction of the reaction site is easily determined. This makes it easier to improve cycle characteristics and storage characteristics. A structure having a saturated hydrocarbon group in which two or more R are linked together to form a ring structure Examples of the structure include the following (* indicates the bond site with the oxygen atom of P(OR)5): ).

[0024] [ka]

[0025] A structure having an unsaturated hydrocarbon group in which two or more R are linked together to form a ring structure The structure includes the following structure (* indicates the bond site with the oxygen atom of P(OR)5). vinegar).

[0026] [ka]

[0027] When two or more R are bonded to each other to form a ring structure, the unsaturated hydrocarbon group is The structure has the ability to trap reactive impurities and polymerize on the negative electrode surface to form a coating. This is preferable in terms of improving durability. Among these, the method is preferred from the viewpoint of availability of raw materials and high production efficiency in manufacturing compounds. The following structures can reduce the manufacturing load. (* indicates P(O R) indicates the bonding site with the oxygen atom of 5).

[0028] [ka]

[0029] Specific examples of preferred compounds represented by the structural formula P(OR)5 include:

[0030] [ka]

[0031] [ka]

[0032] [ka]

[0033] By using this structure, the production efficiency of the compound can be increased. The load can be reduced. Among these, more preferred compounds are

[0034] [ka]

[0035] [ka]

[0036] This structure improves the balance between reactivity and stability with the positive electrode. Therefore, the cycle characteristics and storage characteristics are most likely to be improved. The compound represented by the structural formula P(OR)5 can be used alone or in any combination of two or more. The compounds represented by the structural formula P(OR)5 may be used in combination and in a ratio of 0.1 to 1.0. The content is not particularly limited and may be any content as long as it does not significantly impair the effects of the present invention. When the entire electrolyte solution is taken as 100 mass%, it is usually 0.0001 mass% or more, preferably 0.00 It is 1% by mass or more, more preferably 0.01% by mass or more, and usually 5% by mass or less, preferably It is preferably 3% by mass or less, and more preferably 2% by mass or less. It further improves durability such as the charge capacity, storage capacity, and input / output characteristics, and further reduces battery swelling. This is preferable because it can be lowered.

[0037] The method for measuring P(OR)5 in a non-aqueous electrolyte solution includes the nuclear magnetic resonance method (NMR). When the non-aqueous electrolyte contains LiPF6, which will be described later, the PF6 and P(OR)5 The molar ratio [PF6] / [P(OR)5] is not particularly limited, but is usually 2.0 or more, preferably is 2.5 or more, more preferably 3.0 or more, even more preferably 4.0 or more, and particularly preferably is 10 or more, while the upper limit is usually 2500 or less, preferably 2000 or less, more preferably It is preferably 1000 or less, and more preferably 300 or less. Further improve the durability of the battery, such as capacity, storage capacity, and input / output characteristics, and further reduce battery swelling. In addition, [PF6] is LiPF6 ionized in a non-aqueous electrolyte solution. PF 6 - and PF6 in association with lithium and other ions.

[0038] The method for producing the compound having the structure of P(OR)5 is not particularly limited, and may be a combination of known methods. It can be manufactured. For example, a compound with the formula P(OR)5 can be prepared by reacting the corresponding phosphite with The reaction occurs with peroxides, alkoxysulfanyl compounds, aldehydes, and ketones, producing and then isolating and purifying the resulting mixture.

[0039] The preparation of the non-aqueous electrolyte solution containing the compound represented by the structural formula P(OR)5 is carried out according to the publicly known method. For example, the structural formula of P(OR)5, which was synthesized separately, may be used. A method of adding a compound represented by the formula P(OR)5 to a non-aqueous electrolyte solution, or a method of adding a compound represented by the formula P(OR)5 A method in which a compound represented by the formula: The compound represented by the structural formula P(OR)5 is added to the battery components such as the active material and electrode plates described below. The battery element (battery element) is constructed by mixing the two materials together, and then a non-aqueous electrolyte is poured into the battery element to form a non-aqueous electrolyte secondary battery. When assembling energy devices such as secondary batteries, compounds with the structural formula P(OR)5 are used. A method of dissolving a substance in a non-aqueous electrolyte, a method of dissolving a substance in a non-aqueous electrolyte or a non-aqueous electrolyte secondary battery, A compound capable of generating a compound represented by the structural formula (OR)5 is added in advance to a non-aqueous electrolyte or The electrolyte is mixed in the secondary battery and the compound represented by the structural formula P(OR)5 is mixed in the secondary battery. In the present invention, any of the above methods may be used.

[0040] <2.Non-aqueous electrolyte> <2-1. Electrolytes> The non-aqueous electrolyte in the present invention, like a general non-aqueous electrolyte, usually contains as its components The electrolyte may contain one or more lithium salts. There are no particular limitations on the electrolyte salt, and any electrolyte salt may be used. Any suitable one can be used, and specific examples include the following:

[0041] for example, LiBF4, LiClO4, LiAlF4, LiPF6, LiSbF6, LiTaF6 Inorganic lithium halide salts such as LiWF7; Lithium fluorophosphate salts other than LiPF6, such as Li2PO3F and LiPO2F2 ; Lithium tungstate salts such as LiWOF5; HCO2Li, CH3CO2Li, CH2FCO2Li, CHF2CO2Li, CF3 CO2Li, CF3CH2CO2Li, CF3CF2CO2Li, CF3CF2CF2C Lithium carboxylates such as O2Li, CF3CF2CF2CF2CO2Li; FSO3Li, CH3SO3Li, CH2FSO3Li, CHF2SO3Li, CF3 SO3Li, CF3CF2SO3Li, CF3CF2CF2SO3Li, CF3CF2C Lithium sulfonate salts such as F2CF2SO3Li;

[0042] Lithium methyl sulfate, lithium ethyl sulfate, lithium 2-propynyl sulfate, 1-methyl -2-propynyl lithium sulfate, 1,1-dimethyl-2-propynyl lithium sulfate, 2, Sulfuric acids such as lithium 2,2-trifluoroethyl sulfate and dilithium ethylene disulfate Lithium salts; LiN(FCO2)2, LiN(FCO)(FSO2), LiN(FSO2)2, Li N(FSO2)(CF3SO2), LiN(CF3SO2)2, LiN(C2F5SO2 )2, Lithium cyclic 1,2-perfluoroethane disulfonylimide, Lithium cyclic 1, 3-Perfluoropropanedisulfonylimide, LiN(CF3SO2)(C4F9SO 2) Lithium imide salts such as; LiC(FSO2)3, LiC(CF3SO2)3, LiC(C2F5SO2)3, etc. Lithium methide salts;

[0043] Lithium difluorooxalatoborate, Lithium bis(oxalato)borate, Lithium Lithium tetrafluorooxalatophosphate, Lithium difluorobis(oxalato) Lithium oxalates such as lithium phosphate and lithium tris(oxalato)phosphate salts; Others include LiPF4(CF3)2, LiPF4(C2F5)2, and LiPF4(CF3S O2)2, LiPF4(C2F5SO2)2, LiBF3CF3, LiBF3C2F5, LiBF3C3F7, LiBF2(CF3)2, LiBF2(C2F5)2, LiBF2 Fluorine-containing organic lithium salts such as (CF3SO2)2 and LiBF2(C2F5SO2)2; etc.

[0044] Among these, input / output characteristics after durability tests such as high-temperature storage tests and cycle tests, and charge / discharge In order to further improve the rate charge / discharge characteristics and impedance characteristics, inorganic lithium salts Lithium fluorophosphates, lithium sulfonates, lithium imide salts, lithium Preferably, the oxalate salts are selected from the group consisting of ammonium oxalate salts. Among them, LiPF6, LiBF4, LiSbF6, LiTaF6, Li2PO3F, L iPO2F2, FSO3Li, CF3SO3Li, LiN(FSO2)2, LiN(FS O2)(CF3SO2), LiN(CF3SO2)2, LiN(C2F5SO2)2, Li Lithium Cyclic 1,2-Perfluoroethane Disulfonylimide, Lithium Cyclic 1,3-Perfluoroethane Disulfonylimide Fluoropropanedisulfonylimide, LiC(FSO2)3, LiC(CF3SO2) 3, LiC(C2F5SO2)3, Lithium difluorooxalatoborate, Lithium bi Lithium tetrafluorooxalatophosphate, Lithium oxalatoborate Mudifluorobis(oxalato)phosphate and lithium tris(oxalato)phosphate The sphere has input / output characteristics, high-rate charge / discharge characteristics, impedance characteristics, and high-temperature storage characteristics. This is particularly preferred because it has the effect of improving cycle characteristics and the like.

[0045] The total concentration of these electrolytes in the non-aqueous electrolyte is not particularly limited. When taken as 100% by mass, it is usually 8% by mass or more, preferably 8.5% by mass or more, and more preferably The upper limit is usually 18% by mass or less, preferably 17% by mass or less. When the total concentration of the electrolyte is within the above range, the electrochemical reaction can be carried out with ease. This is preferable since the electrical conductivity is appropriate for battery operation.

[0046] These electrolytes may be used alone or in combination of two or more. Preferred examples of the combinations include LiPF6 and LiBF4, LiPF6 and LiPO2F2, LiPF6 and FSO3Li, LiPF6 and LiN(FSO2)2, LiPF6 and LiN( CF3SO2)2, LiPF6 and lithium bis(oxalato)borate, LiPF6 and lithium Lithium tetrafluorooxalatophosphate, LiPF6 and lithium difluorobis (Oxalato)phosphate, LiPF6, LiBF4, LiPO2F2, LiPF6 and LiBF4 and FSO3Li, LiPF6 and LiPO2F2 and FSO3Li, LiPF6 and LiPO2F2 and lithium bis(oxalato)borate, LiPF6 and LiPO2F2 and lithium difluorobis(oxalato)phosphate, LiPF6 and LiPO2F2 and LiN(FSO2)2, LiPF6 and LiPO2F2 and LiN(CF3SO2)2, L iPF6 and FSO3Li and lithium bis(oxalato)borate, or LiPF6 and FS A combination of O3Li and lithium difluorobis(oxalato)phosphate. In this case, the inclusion of LiPF6 has the effect of improving the characteristics, high temperature storage characteristics, and cycle characteristics. The content is preferably 7% by mass or more, more preferably 7.5% by mass or more, in the non-aqueous electrolyte solution. More preferably, the content is 8% by mass or more, more preferably, 16% by mass or less, and even more preferably, 15% by mass or less. More preferably, the content is 14% by mass or less, and LiBF4, LiPO2F2, FSO3 Li, LiN(FSO2)2LiN(CF3SO2)2, Lithium bis(oxalato)boron The content of lithium difluorobis(oxalato)phosphate is In the electrolyte, the amount is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and even more preferably Preferably, the content is 0.1% by mass or more, more preferably 5% by mass or less, even more preferably 4% by mass or less, and even more preferably 1% by mass or less. The LiPF6 concentration is preferably 3 mass % or less. The total ion content and viscosity of the aqueous electrolyte are well balanced, so the ionic conductivity is not excessive. The internal impedance of the battery is low without any degradation to the input / output characteristics due to the LiPF6 formulation. This makes it easier to achieve improved characteristics, cycle characteristics, and storage characteristics.

[0047] A particularly preferred combination of electrolytes is LiPF6 and LiPO2F2. By combining these with a compound with the structure P(OR)5, the transition from the positive electrode There is a tendency that the elution of metal oxides can be effectively suppressed. These electrolyte materials can be produced by conventionally known methods. Here, the non-aqueous electrolyte solution containing the electrolyte material may be prepared by a known method. There is no particular limitation. For example, a method of adding the electrolyte material separately synthesized to a non-aqueous electrolyte solution The above electrolyte material is mixed into battery components such as active materials and electrodes, which will be described later, to form battery elements (electrolytes). When assembling a battery by injecting a non-aqueous electrolyte solution, in a non-aqueous electrolyte, or by adding water to the active material, electrode plates, separators, and other battery components. A non-aqueous electrolyte secondary battery is assembled using a non-aqueous electrolyte solution containing the electrolyte material. In the present invention, a method of generating other electrolyte materials in the system when assembling the electrolyte is also included. Either method may be used.

[0048] The content of each electrolyte in the non-aqueous electrolyte solution and the non-aqueous electrolyte secondary battery is measured. There are no particular limitations on the method used, and any known method can be used. Specifically, ion chromatography and 19 F nuclear magnetic resonance spectroscopy (hereinafter referred to as "NMR") There are cases where this occurs.)

[0049] <2-2.Non-aqueous solvents> The non-aqueous electrolyte according to one embodiment of the present invention is generally the same as a general non-aqueous electrolyte. The main component is a non-aqueous solvent that dissolves the above-mentioned electrolyte. There is no particular limitation on the organic solvent, and any known organic solvent can be used. Cyclic carbonates, chain carbonates, chain carboxylic acid esters, cyclic carboxylic acid esters Examples of the compound include, but are not limited to, ether compounds, sulfone compounds, and the like. These may be used alone or in combination of two or more. In one embodiment of the present invention, the non-aqueous electrolyte solution is a cyclic carbonate, a chain carbonate, It is preferable that the organic solvent contains at least one selected from the group consisting of carbonates and chain esters.

[0050] <2-2-1. Saturated cyclic carbonates> Examples of the saturated cyclic carbonate include those having an alkylene group having 2 to 4 carbon atoms. do. Specifically, examples of saturated cyclic carbonates having 2 to 4 carbon atoms include ethylene carbonate, propylene carbonate, butylene carbonate, etc. Among them, ethylene carbonate The improved battery performance is due to the improved lithium ion dissociation rate of carbonate and propylene carbonate. From the above viewpoint, the saturated cyclic carbonate may be used alone or in combination of two or more. They may be used in any combination and ratio.

[0051] The content of the saturated cyclic carbonate is not particularly limited, and the effect of the present invention is not significantly impaired. However, when using one type alone, the lower limit of the content is based on 100% by volume of non-aqueous solvent. The amount is usually 3% by volume or more, and preferably 5% by volume or more. This avoids the decrease in electrical conductivity caused by the decrease in the dielectric constant of the electrolyte, and achieves high current for non-aqueous electrolyte secondary batteries. It is easy to set the current discharge characteristics, stability to the negative electrode, and cycle characteristics in a good range. is usually 90% by volume or less, preferably 85% by volume or less, and more preferably 80% by volume or less. By setting the range in this way, the viscosity of the non-aqueous electrolyte can be set in an appropriate range, and the ionic conductivity can be reduced. This suppresses the deterioration of the battery, and further improves the input / output characteristics of non-aqueous electrolyte secondary batteries and improves the cycle This is preferable because it can further improve durability, such as characteristics and storage characteristics.

[0052] Additionally, any combination of two or more kinds of saturated cyclic carbonates can be used. One of the preferred combinations is a combination of ethylene carbonate and propylene carbonate. In this case, the volume ratio of ethylene carbonate to propylene carbonate is 99: The ratio is preferably 1 to 40:60, and more preferably 95:5 to 50:50. The lower limit of the amount of propylene carbonate in the entire solvent is usually 1% by volume or more, preferably It is preferably 2% by volume or more, more preferably 3% by volume or more. The upper limit is usually 30% by volume. The content is preferably 25% by volume or less, and more preferably 20% by volume or less. It is preferable to contain propylene carbonate since this provides even better low-temperature properties.

[0053] <2-2-2. Chain carbonate> As the chain carbonate, those having 3 to 7 carbon atoms are preferred. Specifically, examples of the chain carbonate having 3 to 7 carbon atoms include dimethyl carbonate, diene carbonate, Chill carbonate, di-n-propyl carbonate, diisopropyl carbonate, n- Propyl isopropyl carbonate, ethyl methyl carbonate, methyl n-propyl Carbonate, n-butyl methyl carbonate, isobutyl methyl carbonate, t-butyl ethyl methyl carbonate, ethyl n-propyl carbonate, n-butyl ethyl carbonate ethyl carbonate, isobutyl ethyl carbonate, t-butyl ethyl carbonate, etc. .

[0054] Among them, dimethyl carbonate, diethyl carbonate, di-n-propyl carbonate diisopropyl carbonate, n-propyl isopropyl carbonate, ethyl methion Preferred are methyl carbonate or methyl-n-propyl carbonate, and particularly preferred are dimethyl carbonate and The carbonate may be diethyl carbonate, diethyl carbonate or ethyl methyl carbonate. In addition, chain carbonates having fluorine atoms (hereinafter referred to as "fluorinated chain carbonates") ) can also be suitably used. The number of fluorine atoms is not particularly limited as long as it is 1 or more, but is usually 6 or less, and preferably In the case where the fluorinated chain carbonate has multiple fluorine atoms, the number of fluorine atoms is preferably 4 or less. may be bonded to the same carbon or different carbons. Examples of the chain carbonate include fluorinated dimethyl carbonate derivatives and fluorinated ethyl methyl carbonate derivatives. diethyl carbonate derivatives, and fluorinated diethyl carbonate derivatives.

[0055] Fluorinated dimethyl carbonate derivatives include fluoromethyl methyl carbonate, Difluoromethyl methyl carbonate, trifluoromethyl methyl carbonate, bis( fluoromethyl)carbonate, bis(difluoro)methyl carbonate, bis(trifluoromethyl)carbonate (fluoromethyl) carbonate, etc. Fluorinated ethyl methyl carbonate derivatives include 2-fluoroethyl methyl carbonate. ethyl fluoromethyl carbonate, 2,2-difluoroethyl methyl carbonate 2-Fluoroethyl fluoromethyl carbonate, Ethyl difluoromethyl carbonate 2,2,2-trifluoroethyl methyl carbonate, 2,2-difluoroethyl difluoromethyl carbonate, 2-fluoroethyl difluoromethyl carbonate, ethyl trifluoromethyl carbonate, and the like.

[0056] Fluorinated diethyl carbonate derivatives include ethyl-(2-fluoroethyl) carbonate. carbonate, ethyl (2,2-difluoroethyl) carbonate, bis(2-fluoroethyl) carbonate ethyl)carbonate, ethyl-(2,2,2-trifluoroethyl)carbonate, 2, 2-Difluoroethyl-2'-fluoroethyl carbonate, bis(2,2-difluoro ethyl) carbonate, 2,2,2-trifluoroethyl-2'-fluoroethyl carbonate 2,2,2-trifluoroethyl-2',2'-difluoroethyl carbonate , bis(2,2,2-trifluoroethyl)carbonate, and the like.

[0057] The chain carbonate may be used alone or in any combination and ratio of two or more kinds. They may be used in combination at the same rate. The amount of the chain carbonate is not particularly limited, but is usually 15% by volume of the non-aqueous solvent. % by volume or more, preferably 20% by volume or more, and more preferably 25% by volume or more. Also, the content is usually 90% by volume or less, preferably 85% by volume or less, and more preferably 80% by volume or less. By setting the content of the chain carbonate within the above range, the viscosity of the non-aqueous electrolyte solution can be In order to prevent the decrease in ion conductivity, the inlet / outlet temperature of the non-aqueous electrolyte secondary battery is improved. In addition, the dielectric constant of the non-aqueous electrolyte is easily adjusted to a desired range. This avoids the decrease in electrical conductivity caused by the decrease in the electrolyte, and improves the input / output characteristics and charge / discharge characteristics of non-aqueous electrolyte secondary batteries. This makes it easier to keep the rate characteristics in a favorable range.

[0058] In addition, a specific amount of ethylene carbonate is mixed with a specific chain carbonate. By combining these, battery performance can be significantly improved. For example, dimethyl carbonate and ethyl methyl carbonate are specific chain carbonates. When ethylene carbonate is selected, the content of ethylene carbonate is not particularly limited, and the effects of the present invention can be achieved. The amount is arbitrary as long as it does not significantly impair the properties of the composition, but it is usually 15% by volume or more, preferably 20% by volume or more. The content of dimethyl carbonate is usually 45% by volume or less, preferably 40% by volume or less. The amount is usually 20% by volume or more, preferably 30% by volume or more, and usually 50% by volume or less, preferably or 45% by volume or less, and the content of ethyl methyl carbonate is usually 20% by volume or more. %, preferably 30% by volume or more, and usually 50% by volume or less, preferably 45% by volume or less. By setting the content within the above range, the low-temperature deposition temperature of the electrolyte can be lowered while the non-aqueous electrolyte can be formed. The viscosity of the electrolyte is also reduced, improving ionic conductivity, and enabling high input and output even at low temperatures. Cut.

[0059] <2-2-3. Chain carboxylate ester> The chain carboxylate ester includes those having a total of 3 to 7 carbon atoms in the structural formula. do. Specifically, methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, acetic acid -n-Butyl, isobutyl acetate, t-butyl acetate, methyl propionate, propionic acid Ethyl, n-propyl propionate, isopropyl propionate, n-propionate Butyl, isobutyl propionate, t-butyl propionate, methyl butyrate, ethyl butyrate , n-propyl butyrate, isopropyl butyrate, methyl isobutyrate, ethyl isobutyrate, isobutyric acid -n-propyl, isopropyl isobutyrate, etc.

[0060] Among them, methyl acetate, ethyl acetate, n-propyl acetate, n-butyl acetate, propionate Methyl propionate, Ethyl propionate, N-propyl propionate, Isopropyl propionate Pyridine, methyl butyrate or ethyl butyrate improves ionic conductivity by reducing viscosity and improves cycle This is preferable from the viewpoint of suppressing battery swelling during endurance tests such as storage. The amount of the chain carboxylate is not particularly limited, and may be any amount that does not significantly impair the effects of the present invention. As long as the amount is not limited, it is usually 5% by volume or more, preferably 8% by volume, based on 100% by volume of the non-aqueous solvent. The content is usually 80% by volume or less, and preferably 70% by volume or less. When the content of the acid ester is within the above range, the electrical conductivity of the non-aqueous electrolyte is improved, and the non-aqueous electrolyte is It is easy to improve the input / output characteristics and charge / discharge rate characteristics of the electrolyte secondary battery. The increase in the charge / discharge rate characteristics of the non-aqueous electrolyte secondary battery is suppressed and kept within a favorable range. It becomes easier.

[0061] In addition, when a chain carboxylate is used, it is preferable to use it in combination with a cyclic carbonate. More preferably, a cyclic carbonate and a chain carbonate are used in combination. For example, when a cyclic carbonate and a chain carboxylic acid ester are used in combination, the cyclic carbonate The content of the amine is not particularly limited and may be any amount as long as it does not significantly impair the effects of the present invention. Usually 15% by volume or more, preferably 20% by volume, and usually 45% by volume or less, preferably 40% by volume or less. The content of the chain carboxylate is usually 20% by volume or more, preferably The volume percentage is 30% or more, and usually 55% or less, preferably 50% or less. When a cyclic carbonate, a chain carbonate and a chain carboxylate are used in combination, The content of carbonate is not particularly limited and may be any content as long as it does not significantly impair the effects of the present invention. is usually 15% by volume or more, preferably 20% by volume, and is usually 45% by volume or less, preferably The content of the chain carbonate is usually 25% by volume or more, preferably The content is 30% by volume or more, and usually 84% by volume or less, preferably 80% by volume or less. By setting the temperature within the above range, the viscosity of the non-aqueous electrolyte can be increased while lowering the low-temperature deposition temperature of the electrolyte. This reduces the ionic conductivity and allows for higher input and output even at low temperatures. This is preferable from the viewpoint of further reducing battery swelling.

[0062] <2-2-4. Cyclic carboxylate ester> Examples of cyclic carboxylic acid esters include those having a total of 3 to 12 carbon atoms in their structural formula. Can be obtained. Specifically, gamma-butyrolactone, gamma-valerolactone, gamma-caprolactone, Among them, gamma-butyrolactone is the most suitable for lithium isomers. This is particularly preferred from the viewpoint of improving the battery characteristics resulting from the improvement in the degree of on-dissociation.

[0063] The content of the cyclic carboxylic acid ester is not particularly limited, and may be any amount that does not significantly impair the effects of the present invention. As long as the amount is not limited, it is usually 3% by volume or more, preferably 5% by volume, based on 100% by volume of the non-aqueous solvent. The content is usually 60% by volume or less, and preferably 50% by volume or less. When the content of the acid ester is within the above range, the electrical conductivity of the non-aqueous electrolyte is improved, and the non-aqueous electrolyte is It is easy to improve the input / output characteristics and charge / discharge rate characteristics of the electrolyte secondary battery. The viscosity of the electrolyte is set in an appropriate range, a decrease in electrical conductivity is avoided, an increase in negative electrode resistance is suppressed, and the electrolyte is non-aqueous. This makes it easier to keep the input / output characteristics and charge / discharge rate characteristics of the electrolyte secondary battery within a favorable range.

[0064] <2-2-5. Ether compounds> The ether compounds include chain ethers having 3 to 10 carbon atoms and cyclic ethers having 3 to 6 carbon atoms. Ethers are preferred. Examples of the chain ether having 3 to 10 carbon atoms include diethyl ether, di(2-fluoroethyl ) ether, di(2,2-difluoroethyl) ether, di(2,2,2-trifluoro Ethyl) ether, Ethyl (2-fluoroethyl) ether, Ethyl (2,2,2-trimethylethyl) ether Fluoroethyl) ether, ethyl (1,1,2,2-tetrafluoroethyl) ether , (2-fluoroethyl)(2,2,2-trifluoroethyl)ether, (2-fluoro (1,1,2,2-tetrafluoroethyl) ether, (2,2,2-trifluoroethyl) ether (1,1,2,2-tetrafluoroethyl) ether, ethyl-n-propionate Pyr ether, ethyl (3-fluoro-n-propyl) ether, ethyl (3,3,3- Trifluoro-n-propyl) ether, ethyl (2,2,3,3-tetrafluoro-n -propyl) ether, ethyl (2,2,3,3,3-pentafluoro-n-propyl) Ether, 2-fluoroethyl-n-propyl ether, (2-fluoroethyl)(3- Fluoro-n-propyl) ether, (2-fluoroethyl)(3,3,3-trifluoro 2-fluoroethyl (2,2,3,3-tetrafluoro-n-propyl) ether 2-fluoroethyl (2,2,3,3,3-pentafluoropropyl) ether, 2,2,2-trifluoroethyl-n-propyl ether ether, (2,2,2-trifluoroethyl)(3-fluoro-n-propyl) ether, (2,2,2-trifluoroethyl)(3,3,3-trifluoro-n-propyl) (2,2,2-trifluoroethyl)(2,2,3,3-tetrafluoro-n-propane (2,2,2-trifluoroethyl)(2,2,3,3,3-pentafluoroethyl)ether Fluoro-n-propyl) ether, 1,1,2,2-tetrafluoroethyl-n-propyl Pyrether, (1,1,2,2-tetrafluoroethyl)(3-fluoro-n-propionyl (1,1,2,2-tetrafluoroethyl)(3,3,3-trifluoroethyl)ether -n-propyl) ether, (1,1,2,2-tetrafluoroethyl)(2,2,3, 3-Tetrafluoro-n-propyl) ether, (1,1,2,2-tetrafluoroethylene) 2,2,3,3,3-pentafluoro-n-propyl ether, di-n-propyl ether, (n-propyl)(3-fluoro-n-propyl)ether, (n-propyl (n-propyl)(2,2 ,3,3-tetrafluoro-n-propyl) ether, (n-propyl)(2,2,3, 3,3-Pentafluoro-n-propyl) ether, di(3-fluoro-n-propyl) Ether, (3-fluoro-n-propyl)(3,3,3-trifluoro-n-propyl ) ether, (3-fluoro-n-propyl)(2,2,3,3-tetrafluoro-n- Propyl) ether, (3-fluoro-n-propyl)(2,2,3,3,3-pentafluoro Di(3,3,3-trifluoro-n-propyl) ether, di(3,3,3-trifluoro-n-propyl) ether (3,3,3-trifluoro-n-propyl)(2,2,3,3-tetrafluoro -n-propyl) ether, (3,3,3-trifluoro-n-propyl)(2,2,3 ,3,3-Pentafluoro-n-propyl) ether, di(2,2,3,3-tetrafluoro 2,2,3,3-tetrafluoro-n-propyl) ether, 2,2,3,3,3-Pentafluoro-n-propyl) ether, di(2,2,3,3, 3-Pentafluoro-n-propyl) ether, di-n-butyl ether, dimethoxymethan Methoxymethane, methoxyethoxymethane, methoxy(2-fluoroethoxy)methane, methoxy( 2,2,2-trifluoroethoxy)methanemethoxy(1,1,2,2-tetrafluoro Ethoxy)methane, diethoxymethane, ethoxy(2-fluoroethoxy)methane, ethoxy ethoxy(2,2,2-trifluoroethoxy)methane, ethoxy(1,1,2,2-tetrafluoroethoxy)methane Fluoroethoxy)methane, di(2-fluoroethoxy)methane, (2-fluoroethoxy)methane (2,2,2-trifluoroethoxy)methane, (2-fluoroethoxy)(1,1 ,2,2-tetrafluoroethoxy)methanedi(2,2,2-trifluoroethoxy)methane Tantalum, (2,2,2-trifluoroethoxy)(1,1,2,2-tetrafluoroethoxy) Di(1,1,2,2-tetrafluoroethoxy)methane, dimethoxyethane , methoxyethoxyethane, methoxy(2-fluoroethoxy)ethane, methoxy(2, 2,2-trifluoroethoxy)ethane, methoxy(1,1,2,2-tetrafluoroethane (2-fluoroethoxy)ethane, diethoxyethane, ethoxy(2-fluoroethoxy)ethane, ethoxy Tri(2,2,2-trifluoroethoxy)ethane, ethoxy(1,1,2,2-tetrafluoro Di(2-fluoroethoxy)ethane, di(2-fluoroethoxy)ethane, (2-fluoroethoxy )(2,2,2-trifluoroethoxy)ethane, (2-fluoroethoxy)(1,1, 2,2-tetrafluoroethoxy)ethane, di(2,2,2-trifluoroethoxy)ethane Tantalum, (2,2,2-trifluoroethoxy)(1,1,2,2-tetrafluoroethoxy) ethane, di(1,1,2,2-tetrafluoroethoxy)ethane, ethylene glycol Ethylene glycol di-n-propyl ether, Ethylene glycol di-n-butyl ether, Diethylene glycol dimethyl ether and the like.

[0065] Examples of cyclic ethers having 3 to 6 carbon atoms include tetrahydrofuran and 2-methyltetrahydrofuran. Furan, 3-methyltetrahydrofuran, 1,3-dioxane, 2-methyl-1,3-di oxane, 4-methyl-1,3-dioxane, 1,4-dioxane, etc., and their fluorinated derivatives Examples of suitable compounds include halogenated compounds. Among these, dimethoxymethane, diethoxymethane, ethoxymethoxymethane, ethoxymethane, Ethylene glycol di-n-propyl ether, Ethylene glycol di-n-butyl ether Diethylene glycol dimethyl ether or diethylene glycol dimethyl ether has high solvation ability for lithium ions. is preferable in terms of improving ion dissociation properties. Since it gives the conductivity, dimethoxymethane, diethoxymethane or ethoxymethoxymethane It is.

[0066] The content of the ether-based compound is not particularly limited, as long as it does not significantly impair the effects of the present invention. Although it is optional, it is usually 1% by volume or more, preferably 2% by volume or more, in 100% by volume of the non-aqueous solvent. More preferably, it is 3% by volume or more, and usually, it is 30% by volume or less, and preferably, it is 25% by volume or less. The content of the ether-based compound is more preferably 20% by volume or less. If so, the ionic conductivity is due to the improvement of the lithium ion dissociation degree of the chain ether and the reduction of the viscosity. In addition, when the negative electrode active material is a carbonaceous material, the chain ether is easily Since it is possible to suppress the phenomenon of co-insertion with lithium ions, the input / output characteristics and charge / discharge rate The characteristics can be kept within the appropriate range.

[0067] <2-2-6. Sulfone compounds> The sulfone-based compounds include cyclic sulfones having 3 to 6 carbon atoms and chain sulfones having 2 to 6 carbon atoms. The number of sulfonyl groups in one molecule is preferably 1 or 2. Cyclic sulfones include monosulfone compounds such as trimethylene sulfones and tetramethylsulfones. ethylene sulfones, hexamethylene sulfones; disulfone compounds such as trimethylene di sulfones, tetramethylene disulfones, hexamethylene disulfones, etc. Among them, from the viewpoint of dielectric constant and viscosity, tetramethylene sulfones and tetramethylene disulfones are More preferred are tetramethylsulfones, hexamethylenesulfones and hexamethylenedisulfones. Lamethylene sulfones (sulfolanes) are particularly preferred.

[0068] The sulfolane compounds include sulfolane and / or sulfolane derivatives (hereinafter, also referred to as sulfolane). The sulfolane derivatives are preferably In the sulfolane ring, one or more of the hydrogen atoms bonded to the carbon atoms is replaced by a fluorine atom or an arsenic atom. Preferred are those substituted with alkyl groups. Among them, 2-methylsulfolane, 3-methylsulfolane, 2-fluorosulfolane, 3 -Fluorosulfolane, 2,2-difluorosulfolane, 2,3-difluorosulfolane , 2,4-difluorosulfolane, 2,5-difluorosulfolane, 3,4-difluoro Sulfolane, 2-fluoro-3-methylsulfolane, 2-fluoro-2-methylsulfolane Fluoro-3-methylsulfolane, 3-fluoro-2-methylsulfolane, 4- Fluoro-3-methylsulfolane, 4-fluoro-2-methylsulfolane, 5-fluoro -3-Methylsulfolane, 5-fluoro-2-methylsulfolane, 2-fluoromethylsulfolane Fluoran, 3-fluoromethylsulfolane, 2-difluoromethylsulfolane, 3-difluoro Fluoromethylsulfolane, 2-trifluoromethylsulfolane, 3-trifluoromethyl Sulfolane, 2-fluoro-3-(trifluoromethyl)sulfolane, 3-fluoro-3 -(trifluoromethyl)sulfolane, 4-fluoro-3-(trifluoromethyl)sulfolane Folane, 5-fluoro-3-(trifluoromethyl)sulfolane, etc. have high ionic conductivity. It is preferable because of its high input / output.

[0069] Examples of the chain sulfone include dimethyl sulfone, ethyl methyl sulfone, and diethyl sulfone. sulfone, n-propyl methyl sulfone, n-propyl ethyl sulfone, di-n-propyl Sulfone, isopropyl methyl sulfone, isopropyl ethyl sulfone, diisopropyl Sulfone, n-butyl methyl sulfone, n-butyl ethyl sulfone, t-butyl methyl sulfone sulfone, t-butyl ethyl sulfone, monofluoromethyl methyl sulfone, difluoromethyl ethyl methyl sulfone, trifluoromethyl methyl sulfone, monofluoroethyl methyl sulfone sulfone, difluoroethyl methyl sulfone, trifluoroethyl methyl sulfone, penta Fluoroethyl methyl sulfone, ethyl monofluoromethyl sulfone, ethyl difluoro Methyl sulfone, ethyl trifluoromethyl sulfone, perfluoroethyl methyl sulfone ethyl trifluoroethyl sulfone, ethyl pentafluoroethyl sulfone, di(thylene (trifluoroethyl) sulfone, perfluorodiethyl sulfone, fluoromethyl-n-propane Propyl sulfone, difluoromethyl-n-propyl sulfone, trifluoromethyl-n- Propyl sulfone, fluoromethyl isopropyl sulfone, difluoromethyl isopropyl sulfone, trifluoromethylisopropylsulfone, trifluoroethyl-n-propyl Difluorosulfone, Trifluoroethyl isopropyl sulfone, Pentafluoroethyl-n- Propyl sulfone, pentafluoroethyl isopropyl sulfone, trifluoroethyl- n-Butyl sulfone, trifluoroethyl-t-butyl sulfone, pentafluoroethyl -n-butylsulfone, pentafluoroethyl-t-butylsulfone, and the like.

[0070] Among them, dimethyl sulfone, ethyl methyl sulfone, diethyl sulfone, n-propyl Methyl sulfone, isopropyl methyl sulfone, n-butyl methyl sulfone, t-butyl Methyl sulfone, monofluoromethyl methyl sulfone, difluoromethyl methyl sulfone , trifluoromethyl methyl sulfone, monofluoroethyl methyl sulfone, difluoro Ethyl methyl sulfone, trifluoroethyl methyl sulfone, pentafluoroethyl methyl ethyl monofluoromethyl sulfone, ethyl difluoromethyl sulfone, Tyl trifluoromethyl sulfone, ethyl trifluoroethyl sulfone, ethyl pentafluoro trifluoromethyl-n-propyl sulfone, trifluoromethyl isopropyl sulfone, trifluoroethyl-n-butyl sulfone, trifluoroethyl trifluoromethyl-t-butyl sulfone, trifluoromethyl-n-butyl sulfone or trifluoromethyl Diethyl-t-butyl sulfone is preferred because it has high ionic conductivity and high input / output.

[0071] The content of the sulfone-based compound is not particularly limited, as long as it does not significantly impair the effects of the present invention. Although it is optional, it is usually 0.3 vol% or more, preferably 0.5 vol% or more, in 100 vol% of the non-aqueous solvent. % or more, more preferably 1% or more by volume, and usually 40% or less by volume, preferably 3 The content of the sulfone-based compound is 5% by volume or less, more preferably 30% by volume or less. Within this range, it is easy to obtain an improvement in durability such as cycle characteristics and storage characteristics, and By controlling the viscosity of the non-aqueous electrolyte in an appropriate range, it is possible to avoid a decrease in electrical conductivity, and The input / output characteristics and charge / discharge rate characteristics of the electrolyte secondary battery can be set within appropriate ranges.

[0072] <2-3. Auxiliaries> The nonaqueous electrolyte of the present invention may further contain various auxiliary agents, which will be described in detail below. <2-3-1. Carbon-carbon unsaturated bond and / or fluorine atom Nate> The non-aqueous electrolyte according to one embodiment of the present invention further comprises a cation exchange material having a carbon-carbon unsaturated bond. Contains at least one of a carbonate having a fluorine atom and a carbonate having a fluorine atom. Good too.

[0073] The carbonate having a carbon-carbon unsaturated bond is preferably a carbonate having a carbon-carbon unsaturated bond. Cyclic carbonates having a structure (hereinafter sometimes abbreviated as "unsaturated cyclic carbonates") The carbonate having a fluorine atom is preferably a carbonate having a fluorine atom. Examples of the cyclic carbonate include The cyclic carbonate having a carbon-carbon unsaturated bond is As long as the cyclic carbonate has a carbon-carbon unsaturated bond, there is no particular limitation. Carbonates having a substituent with an aromatic ring can be used. The cyclic carbonates having a carbon-carbon unsaturated bond are also included in the cyclic carbonates having a carbon-carbon unsaturated bond. The method for producing the cyclic carbonate is not particularly limited, and any known method may be selected for production. It is possible.

[0074] The unsaturated cyclic carbonates include vinylene carbonates, aromatic ring or carbon-carbon unsaturated carbonates. Ethylene carbonates and phenyl carbonates substituted with substituents having saturated bonds , vinyl carbonates, and allyl carbonates. Vinylene carbonates include vinylene carbonate and methylvinylene carbonate. 4,5-Dimethylvinylene carbonate, Phenylvinylene carbonate, 4,5- Diphenylvinylene carbonate, Vinylvinylene carbonate, Allylvinylene carbonate Nate and the like.

[0075] Ethylene carbonates substituted with a substituent having an aromatic ring or a carbon-carbon unsaturated bond Specific examples of the vinyl ethylene carbonate include vinyl ethylene carbonate and 4,5-divinyl ethylene carbonate. Phenylethylene carbonate, 4,5-diphenylethylene carbonate, ethynyl Examples of the ethylene carbonate include 4,5-diethynylethylene carbonate and 4,5-diethynylethylene carbonate. Among them, vinylene carbonates, aromatic rings or carbon-carbon unsaturated bonds are preferred. Substituted ethylene carbonates are preferred, especially vinylene carbonate, 4,5-di Phenylvinylene carbonate, 4,5-dimethylvinylene carbonate, vinyl ethylene Ethynyl ethylene carbonate or ethynyl ethylene carbonate forms a stable interface protective coating. and is more preferably used.

[0076] The molecular weight of the unsaturated cyclic carbonate is not particularly limited, and may be any molecular weight that does not significantly impair the effects of the present invention. The molecular weight of the unsaturated cyclic carbonate is usually 50 or more, preferably 80 or more. The average molecular weight is usually 250 or less, and preferably 150 or less. The solubility of the unsaturated cyclic carbonate in the aqueous electrolyte can be easily ensured, and the effects of the present invention can be fully achieved. This is easily expressed in minutes.

[0077] The unsaturated cyclic carbonate may be used alone or in any combination of two or more. The content of the unsaturated cyclic carbonate is not particularly limited. The content of the unsaturated cyclic carbonate is arbitrary as long as it does not significantly impair the effect of the invention. In 100% by mass of the aqueous electrolyte solution, the amount is usually 0.001% by mass or more, and preferably 0.01% by mass or more. % or more, more preferably 0.1% by mass or more, and even more preferably 0.2% by mass or more. The content is usually 10% by mass or less, preferably 8% by mass or less, and more preferably 5% by mass or less. Within the above range, the non-aqueous electrolyte secondary battery has sufficient high-temperature storage characteristics and support. It is easy to realize the effect of improving the rotation characteristics.

[0078] Cyclic carbonates having fluorine atoms (hereinafter referred to as "fluorinated cyclic carbonates") There are no particular limitations on the cyclic carbonate having a fluorine atom. do not have. The fluorinated cyclic carbonates include cyclic carbonates having an alkylene group having 2 to 6 carbon atoms. Examples of the ethylene carbonate derivatives include ethylene carbonate derivatives. Carbonate derivatives include, for example, ethylene carbonate or alkyl groups (e.g., Examples of fluorinated ethylene carbonates include those substituted with alkyl groups having 1 to 4 carbon atoms. Among these, those having 1 to 8 fluorine atoms are preferred.

[0079] Specifically, 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 ethylene carbonate, 4-(trifluoromethyl)-ethylene carbonate, 4-(fluoro 4-(fluoromethyl)-5-fluoroethylene carbonate 4-fluoro-4,5-dimethylethylene carbonate, 4, 5-Difluoro-4,5-dimethylethylene carbonate, 4,4-difluoro-5,5 -Dimethyl ethylene carbonate, etc.

[0080] Among them, monofluoroethylene carbonate, 4,4-difluoroethylene carbonate 4,5-Difluoroethylene carbonate and 4,5-difluoro-4,5-dimethyl At least one selected from the group consisting of ethylene carbonate and ethylene diamine provides high ionic conductivity. This is more preferable in that an interface protective film can be suitably formed. The fluorinated cyclic carbonate may be used alone or in any combination of two or more kinds. The content of the fluorinated cyclic carbonate is not particularly limited, and As long as the effect of the present invention is not significantly impaired, the amount of the non-aqueous electrolyte is arbitrary. It is 0.001 mass% or more, preferably 0.01 mass% or more, and more preferably 0.1 mass% or more. % by mass or more, and usually 8% by mass or less, preferably 6% by mass or less, and more preferably The content is preferably 5 mass % or less. If the content is within this range, the non-aqueous electrolyte secondary battery can be formed with a sufficient size. Within this range, non-aqueous electrolyte secondary batteries are sufficient. It is easy to exhibit excellent cycle characteristics and high-temperature storage characteristics.

[0081] In addition, even if the fluorinated cyclic carbonate is used as an auxiliary agent for the non-aqueous electrolyte, it does not function as a non-aqueous solvent. The content of the fluorinated cyclic carbonate when used as a non-aqueous solvent is In 100% by mass of the non-aqueous electrolyte solution, the amount is usually 8% by mass or more, and preferably 10% by mass or more. More preferably, it is 12% by mass or more, and usually, it is 85% by mass or less, and preferably is 80% by mass or less, and more preferably 75% by mass or less. Aqueous electrolyte secondary batteries are more likely to exhibit sufficient cycle characteristic improvement effects, and the discharge capacity retention rate is low. It's easy to avoid dropping it. In the nonaqueous electrolyte according to one embodiment of the present invention, The carbonate having at least one atom is vinylene carbonate, vinyl ethylene carbonate, ethylene carbonate, ethynyl ethylene carbonate, and fluoroethylene carbonate It is preferable that the compound is at least one selected from the group consisting of:

[0082] <2-3-2. Fluorinated unsaturated cyclic carbonates> The fluorinated cyclic carbonate is a cyclic carbonate having an unsaturated bond and a fluorine atom. (hereinafter sometimes abbreviated as "fluorinated unsaturated cyclic carbonate") The fluorinated unsaturated cyclic carbonate is not particularly limited. The method for producing the fluorinated unsaturated cyclic carbonate is particularly preferably There is no limitation to the method, and the production can be carried out by any known method.

[0083] The fluorinated unsaturated cyclic carbonates include vinylene carbonate derivatives, aromatic ring or Examples include ethylene carbonate derivatives substituted with a substituent having a carbon-carbon unsaturated bond. can be done. Vinylene carbonate derivatives include 4-fluorovinylene carbonate, Fluoro-5-methylvinylene carbonate, 4-fluoro-5-phenylvinylene carbonate ester, 4,5-difluoroethylene carbonate, and the like.

[0084] Ethylene carbonate derivatives substituted with aromatic rings or substituents having carbon-carbon unsaturated bonds Conductors include 4-fluoro-4-vinyl ethylene carbonate, 4-fluoro-5-vinyl Nylethylene carbonate, 4,4-difluoro-4-vinylethylene carbonate, 4 ,5-Difluoro-4-vinyl ethylene carbonate, 4-fluoro-4,5-divinyl Ethylene carbonate, 4,5-difluoro-4,5-divinylethylene carbonate, 4-Fluoro-4-phenylethylene carbonate, 4-fluoro-5-phenylethylene ethylene carbonate, 4,4-difluoro-5-phenylethylene carbonate, 4,5-di Fluoro-4-phenylethylene carbonate and the like.

[0085] The molecular weight of the fluorinated unsaturated cyclic carbonate is not particularly limited, and the effect of the present invention can be significantly improved. As long as it does not impair the molecular weight, it is optional. The molecular weight of the fluorinated unsaturated cyclic carbonate is usually 50 or more. Preferably, it is 80 or more, and usually 250 or less, preferably 150 or less. Within this range, the solubility of the fluorinated cyclic carbonate in the non-aqueous electrolyte can be easily ensured. Therefore, the effects of the present invention are easily achieved.

[0086] The fluorinated unsaturated cyclic carbonate may be used alone or in any combination of two or more kinds. The content of the fluorinated unsaturated cyclic carbonate may be There is no particular limitation, and any one of them may be used as long as it does not significantly impair the effects of the present invention. The content of the cyclic carbonate is usually 0.01% by mass or more in 100% by mass of the non-aqueous electrolyte. It is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, and usually 5% by mass or more. % or less, preferably 4% or less, and more preferably 3% or less. For example, a non-aqueous electrolyte secondary battery is likely to exhibit a sufficient effect of improving cycle characteristics.

[0087] <2-3-3. Cyclic compounds containing SO2 groups> In the nonaqueous electrolyte of the present invention, the cyclic compound having an SO2 group that can be used is The type of the compound is not particularly limited as long as it is a cyclic compound having an SO2 group in the molecule. Compounds having a cyclic sulfonate ester or a cyclic sulfate ester (hereinafter referred to as cyclic sulfuric acid esters) The cyclic sulfate ester compounds are preferably used. More preferred is a compound represented by the following general formula (3): The production method is not particularly limited, and any known method can be selected for production.

[0088] [ka]

[0089] In general formula (3), R 7 and R 8 each independently represents a carbon atom, a hydrogen atom, a nitrogen atom, or an oxygen atom. A halogen atom is a halogen atom. R stands for mechanism. 7 and R 8 may contain unsaturated bonds together with -O-SO2- . Here, R 7 and R 8 is preferably composed of carbon atoms, hydrogen atoms, oxygen atoms, and sulfur atoms. Among them, a hydrocarbon group having 1 to 3 carbon atoms, - An organic group having O-SO2- is preferred.

[0090] The molecular weight of the cyclic compound having an SO2 group is not particularly limited, and it is not necessary to significantly impair the effects of the present invention. The molecular weight of the cyclic compound having an SO2 group is usually 100 or more, and preferably is 100 or more. The molecular weight is usually 110 or more, and is usually 250 or less, preferably 220 or less. Within this range, it is easy to ensure the solubility of the cyclic compound having an SO2 group in the non-aqueous electrolyte. In this case, the effects of the present invention are easily manifested.

[0091] Specific examples of the compound represented by formula (3) include, for example, 1,3-propane sultone, 1-fluoro-1,3-propane sultone, 2-fluoro -1,3-propane sultone, 3-fluoro-1,3-propane sultone, 1-methyl- 1,3-propane sultone, 2-methyl-1,3-propane sultone, 3-methyl-1, 3-Propane sultone, 1-propene-1,3-sultone, 2-propene-1,3-sultone ton, 1-fluoro-1-propene-1,3-sultone, 2-fluoro-1-propene- 1,3-sultone, 3-fluoro-1-propene-1,3-sultone, 1-fluoro-2 -propene-1,3-sultone, 2-fluoro-2-propene-1,3-sultone, 3- Fluoro-2-propene-1,3-sultone, 1-methyl-1-propene-1,3-sultone ton, 2-methyl-1-propene-1,3-sultone, 3-methyl-1-propene-1, 3-sultone, 1-methyl-2-propene-1,3-sultone, 2-methyl-2-propene 3-Methyl-2-propene-1,3-sultone, 1,4-butane Sultone, 1-fluoro-1,4-butanesultone, 2-fluoro-1,4-butanesultone ton, 3-fluoro-1,4-butane sultone, 4-fluoro-1,4-butane sultone , 1-methyl-1,4-butane sultone, 2-methyl-1,4-butane sultone, 3-methyl 4-methyl-1,4-butane sultone, 1-butene-1 ,4-sultone, 2-butene-1,4-sultone, 3-butene-1,4-sultone, 1- Fluoro-1-butene-1,4-sultone, 2-fluoro-1-butene-1,4-sultone sultone, 3-fluoro-1-butene-1,4-sultone, 4-fluoro-1-butene-1,4 -Sultone, 1-fluoro-2-butene-1,4-sultone, 2-fluoro-2-butene -1,4-sultone, 3-fluoro-2-butene-1,4-sultone, 4-fluoro-2 -Butene-1,4-sultone, 1-fluoro-3-butene-1,4-sultone, 2-fluoro 3-fluoro-3-butene-1,4-sultone, 3-fluoro-3-butene-1,4-sultone, 4-Fluoro-3-butene-1,4-sultone, 1-methyl-1-butene-1,4-sultone ton, 2-methyl-1-butene-1,4-sultone, 3-methyl-1-butene-1,4- Sultone, 4-methyl-1-butene-1,4-sultone, 1-methyl-2-butene-1, 4-Sultone, 2-methyl-2-butene-1,4-sultone, 3-methyl-2-butene- 1,4-sultone, 4-methyl-2-butene-1,4-sultone, 1-methyl-3-butene 2-Methyl-3-butene-1,4-sultone, 3-Methyl-3-butene-1,4-sultone Butene-1,4-sultone, 4-methyl-3-butene-1,4-sultone, 1,5-pentene Tansultone, 1-fluoro-1,5-pentanesultone, 2-fluoro-1,5-pentanesultone Tansultone, 3-fluoro-1,5-pentanesultone, 4-fluoro-1,5-pentanesultone Tansultone, 5-fluoro-1,5-pentanesultone, 1-methyl-1,5-pentanesultone sultone, 2-methyl-1,5-pentanesultone, 3-methyl-1,5-pentanesultone sultone, 4-methyl-1,5-pentanesultone, 5-methyl-1,5-pentanesultone 1-pentene-1,5-sultone, 2-pentene-1,5-sultone, 3-pentene -1,5-sultone, 4-pentene-1,5-sultone, 1-fluoro-1-pentene- 1,5-sultone, 2-fluoro-1-pentene-1,5-sultone, 3-fluoro-1 -Pentene-1,5-sultone, 4-fluoro-1-pentene-1,5-sultone, 5- Fluoro-1-pentene-1,5-sultone, 1-fluoro-2-pentene-1,5-sultone sultone, 2-fluoro-2-pentene-1,5-sultone, 3-fluoro-2-pentene -1,5-sultone, 4-fluoro-2-pentene-1,5-sultone, 5-fluoro- 2-Pentene-1,5-sultone, 1-Fluoro-3-pentene-1,5-sultone, 2 -Fluoro-3-pentene-1,5-sultone, 3-fluoro-3-pentene-1,5- Sultone, 4-fluoro-3-pentene-1,5-sultone, 5-fluoro-3-pentene 1-Fluoro-4-pentene-1,5-sultone, 2-Fluoro -4-pentene-1,5-sultone, 3-fluoro-4-pentene-1,5-sultone, 4-Fluoro-4-pentene-1,5-sultone, 5-Fluoro-4-pentene-1,5 -Sultone, 1-methyl-1-pentene-1,5-sultone, 2-methyl-1-pentene -1,5-sultone, 3-methyl-1-pentene-1,5-sultone, 4-methyl-1- Pentene-1,5-sultone, 5-methyl-1-pentene-1,5-sultone, 1-methyl 2-methyl-2-pentene-1,5-sultone, 2-methyl-2-pentene-1,5-sultone, 3-Methyl-2-pentene-1,5-sultone, 4-Methyl-2-pentene-1,5-sultone sultone, 5-methyl-2-pentene-1,5-sultone, 1-methyl-3-pentene-1 ,5-sultone, 2-methyl-3-pentene-1,5-sultone, 3-methyl-3-pentene 4-Methyl-3-pentene-1,5-sultone, 5-Methyl- 3-pentene-1,5-sultone, 1-methyl-4-pentene-1,5-sultone, 2- Methyl-4-pentene-1,5-sultone, 3-methyl-4-pentene-1,5-sultone 4-Methyl-4-pentene-1,5-sultone, 5-Methyl-4-pentene-1,5 -Sultone, 1,2-oxathiolane-2,2-dioxid-4-yl-acetate, 1 ,2-Oxathiolane-2,2-dioxid-4-yl-propionate, 5-methyl- 1,2-Oxathiolane-2,2-dioxid-4-one-2,2-dioxide, 5,5 -Dimethyl-1,2-oxathiolane-2,2-dioxid-4-one-2,2-diox Sultone compounds such as cids;

[0092] Disulfonates such as methylenemethane disulfonate and ethylenemethane disulfonate compound; 1,2,3-Oxathiazolidine-2,2-dioxide, 3-methyl-1,2,3-oxathiazolidine Oxathiazolidine-2,2-dioxide, 3H-1,2,3-oxathiazole-2,2 -dioxide, 5H-1,2,3-oxathiazole-2,2-dioxide, 1,2,4 -Oxathiazolidine-2,2-dioxide, 4-methyl-1,2,4-oxathiazolidine Zine-2,2-dioxide, 3H-1,2,4-oxathiazole-2,2-dioxide , 5H-1,2,4-oxathiazole-2,2-dioxide, 1,2,5-oxathiazole Zolidine-2,2-dioxide, 5-methyl-1,2,5-oxathiazolidine-2,2 -dioxide, 3H-1,2,5-oxathiazole-2,2-dioxide, 5H-1, 2,5-Oxathiazole-2,2-dioxide, 1,2,3-Oxathiazinane-2, 2-dioxide, 3-methyl-1,2,3-oxathiazinane-2,2-dioxide, 5 ,6-Dihydro-1,2,3-oxathiazine-2,2-dioxide, 1,2,4-oxathiazine Sathiazinane-2,2-dioxide, 4-methyl-1,2,4-oxathiazinane-2, 2-Dioxide, 5,6-dihydro-1,2,4-oxathiazine-2,2-dioxide , 3,6-dihydro-1,2,4-oxathiazine-2,2-dioxide, 3,4-dihydro 1,2,4-oxathiazine-2,2-dioxide, 1,2,5-oxathiazine 5-Methyl-1,2,5-oxathiazinan-2,2-dioxide Cid, 5,6-dihydro-1,2,5-oxathiazine-2,2-dioxide, 3,6- Dihydro-1,2,5-oxathiazine-2,2-dioxide, 3,4-dihydro-1, 2,5-Oxathiazine-2,2-dioxide, 1,2,6-Oxathiazinane-2,2 -dioxide, 6-methyl-1,2,6-oxathiazinane-2,2-dioxide, 5, 6-Dihydro-1,2,6-oxathiazine-2,2-dioxide, 3,4-dihydro- 1,2,6-Oxathiazine-2,2-dioxide, 5,6-dihydro-1,2,6-oxathiazine Nitrogen-containing compounds such as xathiazine-2,2-dioxide;

[0093] 1,2,3-Oxathiaphoslan-2,2-dioxide, 3-methyl-1,2,3-o Oxathiaphoslan-2,2-dioxide, 3-methyl-1,2,3-oxathiaphoslan -2,2,3-trioxide, 3-methoxy-1,2,3-oxathiaphoslan-2,2 ,3-trioxide, 1,2,4-oxathiaphoslan-2,2-dioxide, 4-methyl 4-Methyl-1,2,4-oxathiaphoslan-2,2-dioxide Oxathiaphoslan-2,2,4-trioxide, 4-methoxy-1,2,4-oxathi Aphoslan-2,2,4-trioxide, 1,2,5-oxathiaphoslan-2,2-dioxide oxide, 5-methyl-1,2,5-oxathiaphoslan-2,2-dioxide, 5-methyl Thiol-1,2,5-oxathiaphoslan-2,2,5-trioxide, 5-methoxy-1 ,2,5-Oxathiafoslan-2,2,5-trioxide, 1,2,3-Oxathiafoslan-2,2,5-trioxide Suphinane-2,2-dioxide, 3-methyl-1,2,3-oxathiaphosphinane- 2,2-Dioxide, 3-Methyl-1,2,3-oxathiaphosphinane-2,2,3- Trioxide, 3-Methoxy-1,2,3-oxathiaphosphinane-2,2,3-trioxide Oxide, 1,2,4-Oxathiaphosphinane-2,2-dioxide, 4-Methyl-1 ,2,4-Oxathiaphosphinane-2,2-dioxide, 4-Methyl-1,2,4-o Xathiaphosphinane-2,2,3-trioxide, 4-methyl-1,5,2,4-dioxide Xathiaphosphinane-2,4-dioxide, 4-methoxy-1,5,2,4-dioxa Thiaphosphinane-2,4-dioxide, 3-methoxy-1,2,4-oxathiaphosphine 1,2,5-Oxathiaphosphinane-2,2-dioxide oxide, 5-methyl-1,2,5-oxathiaphosphinane-2,2-dioxide, 5 -Methyl-1,2,5-oxathiaphosphinane-2,2,3-trioxide, 5-Methoxy Oxy-1,2,5-oxathiaphosphinane-2,2,3-trioxide, 1,2,6- Oxathiaphosphinane-2,2-dioxide, 6-methyl-1,2,6-oxathiaphosphinane Suphinane-2,2-dioxide, 6-methyl-1,2,6-oxathiaphosphinane- 2,2,3-trioxide, 6-methoxy-1,2,6-oxathiaphosphinane-2, Phosphorus-containing compounds such as 2,3-trioxide;

[0094] 1,2-Ethylene sulfate, 1,2-Propylene sulfate, 1,3-Propylene Butylene sulfate, 1,2-butylene sulfate, 1,3-butylene sulfate, 1, 4-Butylene sulfate, 1,2-pentylene sulfate, 1,3-pentylene sulfate 1,4-pentylene sulfate and 1,5-pentylene sulfate, vinyl alkylene sulfate compounds such as toluene sulfate; etc.

[0095] Among these, 1,3-propane sultone, 1-fluoro-1,3-propane sultone , 2-fluoro-1,3-propane sultone, 3-fluoro-1,3-propane sultone , 1-propene-1,3-sultone, 1-fluoro-1-propene-1,3-sultone, 2-Fluoro-1-propene-1,3-sultone, 3-Fluoro-1-propene-1,3 -Sultone, 1,4-butane sultone, methylenemethane disulfonate, ethylenemethane Disulfonate, 1,2-ethylene sulfate, 1,2-propylene sulfate or 1,3-propylene sulfate is preferred from the viewpoint of improving storage properties, and 1,3-propane sulfate is preferred. sultone, 1-fluoro-1,3-propane sultone, 2-fluoro-1,3-propane sultone, 3-fluoro-1,3-propane sultone, 1-propene-1,3-sultone, Methylenemethane disulfonate, Ethylenemethane disulfonate, 1,2-Ethylenesulfonate More preferred are 1,3-propylene sulfate and 1,3-propylene sulfate.

[0096] The cyclic compound having an SO2 group may be used alone or in any combination of two or more. The amount of the ring having the SO2 group relative to the entire non-aqueous electrolyte solution of the present invention may be determined in a certain combination and ratio. There is no limitation on the content of the crystalline compound, and it is optional as long as it does not significantly impair the effects of the present invention. The amount of the non-aqueous electrolyte of the present invention is usually 0.001% by mass or more, preferably 0.01% by mass or more. More preferably, the content is 0.1% by mass or more, and even more preferably, the content is 0.3% by mass or more. The concentration is 10% by mass or less, preferably 5% by mass or less, and more preferably 3% by mass or less. When the above range is satisfied, the cycle characteristics, high-temperature storage characteristics, etc. are improved, and the battery expansion is suppressed. This is preferable from the viewpoint of reducing leakage.

[0097] <2-3-4. Compounds containing a cyano group> In the nonaqueous electrolyte solution of the present invention, compounds having a cyano group that can be used include The type of the compound is not particularly limited as long as it has a cyano group in the molecule. The compound represented by the general formula (4) is more preferable. The method for producing the compound having a cyano group is particularly The method is not limited to the above, and the compound can be produced by any known method.

[0098] [ka]

[0099] In the general formula (4), T is a carbon atom, a hydrogen atom, a nitrogen atom, an oxygen atom, a sulfur atom, a phosphorus atom, represents an organic group composed of atoms selected from the group consisting of alkyl, aryl and halogen atoms, and U is a substituent V is an organic group having 1 to 10 carbon atoms and may have a valence of 5. V is an integer of 1 or more, When there are two or more T's, they may be the same or different. The molecular weight of the compound having a cyano group is not particularly limited, and may be any molecular weight that does not significantly impair the effects of the present invention. The molecular weight of the compound having a cyano group is usually 40 or more, and preferably is 45 or more, more preferably 50 or more, and is usually 200 or less, preferably 180 Within this range, the shear resistance to the non-aqueous electrolyte solution is low. The solubility of the compound having the .beta.-group is easily ensured, and the effects of the present invention are easily achieved.

[0100] Specific examples of the compound represented by formula (4) include, for example, Acetonitrile, propionitrile, butyronitrile, isobutyronitrile, valeron tolyl, isovaleronitrile, lauronitrile 2-methylbutyronitrile, trimethyla Acetonitrile, Hexanenitrile, Cyclopentanecarbonitrile, Cyclohexanecarbonitrile Acrylonitrile, Methacrylonitrile, Crotononitrile, 3-Methyl Lotononitrile, 2-methyl-2-butenenitrile, 2-pentenenitrile, 2-methyl -2-pentenenitrile, 3-methyl-2-pentenenitrile, 2-hexenenitrile, Fluoroacetonitrile, difluoroacetonitrile, trifluoroacetonitrile, 2 -Fluoropropionitrile, 3-fluoropropionitrile, 2,2-difluoropropionitrile Propionitrile, 2,3-difluoropropionitrile, 3,3-difluoropropionitrile 2,2,3-trifluoropropionitrile, 3,3,3-trifluoropropionitrile Nitriles, 3,3'-oxydipropionitrile, 3,3'-thiodipropionitrile, 1,2,3-propanetricarbonitrile, 1,3,5-pentanetricarbonitrile, Compounds containing one cyano group, such as pentafluoropropionitrile;

[0101] Malononitrile, succinonitrile, glutaronitrile, adiponitrile, pimelonite Nitrile, Suberonitrile, Azelanitrile, Sebaconitrile, Undecanedinitrile, Dodecanedinitrile Candinitrile, methylmalononitrile, ethylmalononitrile, isopropylmalononitrile tolyl, tert-butylmalononitrile, methylsuccinonitrile, 2,2-dimethyl Succinonitrile, 2,3-dimethylsuccinonitrile, trimethylsuccinonitrile, Tetramethylsuccinonitrile, 3,3'-(ethylenedioxy)dipropionitrile, Compounds with two cyano groups, such as 3,3'-(ethylenedithio)dipropionitrile; 1,2,3-Tris(2-cyanoethoxy)propane, Tris(2-cyanoethyl)a Compounds with three cyano groups, such as amine;

[0102] Methyl cyanate, ethyl cyanate, propyl cyanate, butyl cyanate, penta Cyanate compounds such as ethyl cyanate, hexyl cyanate, and heptyl cyanate; Methyl thiocyanate, ethyl thiocyanate, propyl thiocyanate, butyl thiocyanate cyanate, pentyl thiocyanate, hexyl thiocyanate, heptyl thiocyanate methanesulfonyl cyanide, ethanesulfonyl cyanide, propanesulfonyl cyanide butanesulfonyl cyanide, pentanesulfonyl cyanide, hexanesulfonyl cyanide Nido, heptanesulfonylcyanide, methylsulfurocyanidate, ethylsulfurocyanidate Nitto, Propyl Sulfurocyanidate, Butyl Sulfurocyanidate, Pentyl Sulfur Phosphonate, hexylsulfosphonate, heptylsulfosphonate, etc. Sulfur-containing compounds;

[0103] Cyanodimethylphosphine, Cyanodimethylphosphine oxide, Cyanomethylphosphine Methyl phosphinate, methyl cyanomethylphosphinite, dimethylphosphinic cyanide, Methylphosphinite cyanide, Dimethyl cyanophosphonate, Dimethyl cyanophosphonate Cyanomethyl methylphosphonate, Cyanomethyl methylphosphonite, Cyanodiphosphate Phosphorus-containing compounds such as cyanodimethyl methyl phosphite; etc.

[0104] Of these, acetonitrile, propionitrile, butyronitrile, and isobutyronite valeronitrile, isovaleronitrile, lauronitrile, crotononitrile, 3- Methylcrotononitrile, malononitrile, succinonitrile, glutaronitrile, azide Polynitrile, Pimelonitrile, Suberonitrile, Azelanitrile, Sebaconitrile, Un Decanedinitrile or dodecanedinitrile is preferred from the viewpoint of improving storage properties. Malononitrile, succinonitrile, glutaronitrile, adiponitrile, Pimelonitrile, Suberonitrile, Azelanitrile, Sebaconitrile, Undecanedinitrile Of these, diphenylnitrile, diphenylnitrile, or dodecanedinitrile are more preferred.

[0105] The compound having a cyano group may be used alone or in any combination of two or more. The compound having a cyano group relative to the entire non-aqueous electrolyte solution of the present invention may be used in the above ratio. There is no limit to the content of the compound, and it is optional as long as it does not significantly impair the effects of the present invention. The amount of the aqueous electrolyte is usually 0.001% by mass or more, preferably 0.01% by mass or more, Preferably, the content is 0.1% by mass or more, more preferably 0.3% by mass or more, and usually 10% by mass or more. % or less, preferably 5% or less, and more preferably 3% or less. If the above range is satisfied, the input / output characteristics, charge / discharge rate characteristics, cycle characteristics, and high-temperature storage characteristics The effects of the above will be further improved.

[0106] <2-3-5. Isocyanate compounds> Compounds having an isocyanate group that can be used in the nonaqueous electrolyte solution of the present invention (hereinafter sometimes abbreviated as "isocyanate compound") is a compound that has isocyanate in the molecule. There are no particular limitations on the type of compound as long as it has an isocyanate group. The compound is preferably a diisocyanate compound having two isocyanate groups in the molecule. I wish.

[0107] <2-3-5-1. Diisocyanate compounds> In the non-aqueous electrolyte solution of the present invention, the diisocyanate compound that can be used is In the molecule, only the isocyanate group has a nitrogen atom, and is represented by the following general formula (5): Compounds in which

[0108] [ka]

[0109] In the above general formula (5), X may contain a cyclic structure and has 1 to 15 carbon atoms. The carbon number of X is usually 2 or more, preferably 3 or more, and more preferably 4. or more, and is usually 14 or less, preferably 12 or less, more preferably 10 or less, and Preferably, it is 8 or less. In the above general formula (5), X is a cycloalkylene group having 4 to 6 carbon atoms or an aromatic hydrocarbon group. It is particularly preferable that the organic group has one or more radicals and has 4 to 15 carbon atoms. The hydrogen atoms on the cycloalkylene group may be substituted with methyl or ethyl groups. Diisocyanate compounds with a cyclic structure are bulky molecules, so they are difficult to form positive electrodes. As a result, the cycle characteristics and high-temperature storage characteristics are improved. Here, there is no particular limitation on the bonding site of the group bonded to the cycloalkylene group or aromatic hydrocarbon group. The position is not limited, and may be any of the meta position, the para position, and the ortho position. However, the meta position or the para position is The appropriate inter-coating cross-linking distance is advantageous for lithium ion conductivity and reduces resistance. The cycloalkylene group is preferably a cyclopentylene group or a cyclohexylene group. The silane group is preferred from the viewpoint that the diisocyanate compound itself is less likely to cause side reactions. The fact that it is a cyclohexylene group makes it easy to reduce resistance due to the influence of molecular mobility. Therefore, it is more preferable.

[0110] In addition, there is a carbon atom between the cycloalkylene group or aromatic hydrocarbon group and the isocyanate group. It is preferable that the alkylene group has a prime number of 1 to 3. Since the alkylene group is physically bulky, side reactions on the positive electrode are less likely to occur. If the prime number is between 1 and 3, the proportion of isocyanate groups to the total molecular weight does not change significantly. Therefore, the effects of the present invention are more likely to be exhibited significantly.

[0111] The molecular weight of the diisocyanate compound represented by the above general formula (5) is not particularly limited, The molecular weight is usually 80 or more, and preferably 100 or more. is 115 or more, more preferably 170 or more, and is usually 300 or less, preferably Within this range, the diisocyanate compound for the non-aqueous electrolyte solution is In this way, the solubility of the substance can be easily ensured, and the effects of the present invention can be easily achieved.

[0112] Specific examples of the diisocyanate compound include, for example, 1,2-Diisocyanatocyclopentane, 1,3-Diisocyanatocyclopentane, 1 ,2-Diisocyanatocyclohexane, 1,3-Diisocyanatocyclohexane, 1,4 -Diisocyanatocyclohexane, 1,2-bis(isocyanatomethyl)cyclohexane , 1,3-bis(isocyanatomethyl)cyclohexane, 1,4-bis(isocyanatomethyl)cyclohexane (ethyl)cyclohexane, dicyclohexylmethane-2,2'-diisocyanate, dicyclohexyl Dicyclohexylmethane-2,4'-diisocyanate, Dicyclohexylmethane-3,3'- Cycloisocyanates such as dicyclohexylmethane-4,4'-diisocyanate Alkane ring-containing diisocyanates;

[0113] 1,2-Phenylene diisocyanate, 1,3-Phenylene diisocyanate, 1,4 -Phenylene diisocyanate, Tolylene-2,3-diisocyanate, Tolylene-2, 4-Diisocyanate, Tolylene-2,5-diisocyanate, Tolylene-2,6-diisocyanate Socyanate, Tolylene-3,4-diisocyanate, Tolylene-3,5-diisocyanate 1,2-bis(isocyanatomethyl)benzene, 1,3-bis(isocyanatomethyl) 1,4-bis(isocyanatomethyl)benzene, 2,4-diisocyanato Biphenyl, 2,6-diisocyanatobiphenyl, 2,2′-diisocyanatobiphenyl , 3,3′-diisocyanatobiphenyl, 4,4′-diisocyanato-2-methylbiphenyl Nyl, 4,4'-diisocyanato-3-methylbiphenyl, 4,4'-diisocyanato- 3,3′-Dimethylbiphenyl, 4,4′-Diisocyanatodiphenylmethane, 4,4′ -Diisocyanato-2-methyldiphenylmethane, 4,4′-diisocyanato-3-methyl Diphenylmethane, 4,4'-diisocyanato-3,3'-dimethyldiphenylmethane , 1,5-diisocyanatonaphthalene, 1,8-diisocyanatonaphthalene, 2,3-di Isocyanatonaphthalene, 1,5-bis(isocyanatomethyl)naphthalene, 1,8-bis Bis(isocyanatomethyl)naphthalene, 2,3-bis(isocyanatomethyl)naphthalene Aromatic ring-containing diisocyanates such as those mentioned above; etc.

[0114] Among these, 1,2-diisocyanatocyclopentane, 1,3-diisocyanatocyclopentane, Cyclopentane, 1,2-diisocyanatocyclohexane, 1,3-diisocyanatocyclo Hexane, 1,4-diisocyanatocyclohexane, 1,2-bis(isocyanatomethyl )Cyclohexane, 1,3-bis(isocyanatomethyl)cyclohexane, 1,4-bis (Isocyanatomethyl)cyclohexane, 1,2-phenylene diisocyanate, 1,3 -Phenylene diisocyanate, 1,4-phenylene diisocyanate, 1,2-bis( Isocyanatomethyl)benzene, 1,3-bis(isocyanatomethyl)benzene, 1,4 -Bis(isocyanatomethyl)benzene, 2,4-diisocyanatobiphenyl or 2,6 -Diisocyanatobiphenyl forms a dense composite coating on the negative electrode, resulting in This is preferable since it improves the durability of the battery.

[0115] Among these, 1,3-bis(isocyanatomethyl)cyclohexane, 1,4-bis (Isocyanatomethyl)cyclohexane, 1,3-phenylene diisocyanate, 1,4 -Phenylene diisocyanate, 1,2-bis(isocyanatomethyl)benzene, 1,3 -Bis(isocyanatomethyl)benzene or 1,4-bis(isocyanatomethyl)benzene However, due to the symmetry of the molecule, a coating that is favorable for lithium ion conductivity is formed on the negative electrode, and As a result, the battery characteristics are further improved, which is more preferable.

[0116] The above-mentioned diisocyanate compounds may be used alone or in any combination of two or more. They may be used in any combination and ratio. Content of diisocyanate compound that can be used in the nonaqueous electrolyte solution of the present invention is not particularly limited and may be any as long as it does not significantly impair the effects of the present invention. The amount of the base electrolyte is usually 0.001% by mass or more, preferably 0.01% by mass or more, and more preferably Preferably, the content is 0.1% by mass or more, more preferably 0.3% by mass or more, and usually, 5% by mass or more. Preferably, the content is 4% by mass or less, more preferably 3% by mass or less, and even more preferably 2% by mass or less. When the content is within the above range, durability in cycles, storage, etc. can be improved, and the present invention The effect of light can be fully exerted. The method for producing the diisocyanate compound is not particularly limited, and any known method can be selected. Alternatively, a commercially available product may be used.

[0117] <2-3-5-2. Isocyanate compounds other than diisocyanate compounds> The non-aqueous electrolyte of the present invention does not contain an isocyanate compound other than a diisocyanate compound. The following diisocyanates can be used in the nonaqueous electrolyte solution of the present invention. The isocyanate compounds other than the compound will be described below by giving specific examples. Specific examples of the isocyanate compound include, for example, Methyl isocyanate, ethyl isocyanate, propyl isocyanate, isopropyl isocyanate, butyl isocyanate, t-butyl isocyanate, pentyl isocyanate Anate, hexyl isocyanate, cyclohexyl isocyanate, phenyl isocyanate hydrocarbon monoisocyanate compounds such as phenylisocyanate and fluorophenylisocyanate; Vinyl isocyanate, allyl isocyanate, ethynyl isocyanate, propynyl Monoisocyanate compounds having carbon-carbon unsaturated bonds, such as isocyanates; (ortho-, meta-, para-)toluenesulfonyl isocyanate, benzenesulfonyl isocyanate, fluorosulfonyl isocyanate, phenoxysulfonyl isocyanate Pentafluorophenoxysulfonyl isocyanate, Methoxysulfonyl isocyanate Isocyanate compounds such as cyanates; etc.

[0118] The isocyanate compounds described above may be used alone or in any combination of two or more. Any combination and ratio may be used. There is no limitation on the content of the isocyanate compound in the entire nonaqueous electrolyte solution of the present invention. The content is arbitrary as long as it does not significantly impair the effect of the present invention. Usually, it is 0.001% by mass or more, preferably 0.01% by mass or more, and 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. % by mass or less, more preferably 2% by mass or less, particularly preferably 1% by mass or less, and most preferably When the content is within the above range, durability during cycles, storage, etc. is improved. can be improved, and the effects of the present invention can be fully exhibited. The method for producing the isocyanate compound is not particularly limited, and any known method may be selected. Alternatively, a commercially available product may be used.

[0119] <2-3-6. Carboxylic acid anhydrides> In the nonaqueous electrolyte solution of the present invention, the following carboxylic acid anhydrides can be used: The compound represented by the general formula (6) is preferred. The method for producing the carboxylic acid anhydride is not particularly limited. It is possible to produce the compound by any known method.

[0120] [ka]

[0121] In general formula (6), R9 and R 10 each independently represents a carbon atom which may have a substituent; R represents a hydrocarbon group having a number of 1 to 15. 9 and R 10 are bonded together to form a ring structure It may be possible to do so. R 9 and R 10 is not particularly limited as long as it is a monovalent hydrocarbon group. For example, The hydrocarbon group may be either an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group may be a saturated hydrocarbon group. and may contain unsaturated bonds (carbon-carbon double bonds or carbon-carbon triple bonds). The aliphatic hydrocarbon group may be either linear or cyclic. may be linear or branched. Furthermore, it may be a combination of a linear and a cyclic structure. It should be noted that R 9 and R 10 may be the same or different. stomach.

[0122] Also, R 9 and R 10 When they are bonded together to form a ring structure, R 9 and R 10 Mutually The hydrocarbon group formed by bonding together is divalent. The type of divalent hydrocarbon group is not particularly limited. That is, it may be an aliphatic group or an aromatic group, or it may be a combination of an aliphatic group and an aromatic group. In the case of an aliphatic group, it may be a saturated group or an unsaturated group. In addition, it may be a chain group or a cyclic group. In the case of a chain group, it may be a straight chain group or a branched chain group. It may also be something like that.

[0123] Also, R 9 and R10 When the hydrocarbon group has a substituent, the type of the substituent is As long as it is not contrary to the spirit of the invention, there is no particular limitation, but examples thereof include a fluorine atom and a chlorine atom. Examples of the halogen atom include a halogen atom such as a bromine atom and an iodine atom, and a fluorine atom is preferred. The substituents other than halogen atoms include ester groups, cyano groups, carbonyl groups, ether groups, etc. R is preferably a cyano group or a carbonyl group. 9 and R 10 The hydrocarbon group may have only one of these substituents, or may have two or more. When two or more substituents are present, the substituents may be the same. , may be different from each other.

[0124] R 9 and R 10 The number of carbon atoms in each of the hydrocarbon groups is usually 1 or more and usually 15 or less. , preferably 12 or less, more preferably 10 or less, and even more preferably 9 or less. 9 and R 10 When the and are bonded to each other to form a divalent hydrocarbon group, the divalent hydrocarbon The carbon number of the aryl group is usually 1 or more and usually 15 or less, preferably 13 or less, more preferably It is preferably 10 or less, and more preferably 8 or less. 9 and R 10 The hydrocarbon group of If the group has a substituent containing a nitrogen atom, the group R including the substituent 9 and R 10 Total Carbon It is preferable that the number is within the above range.

[0125] Next, a carboxylic acid anhydride represented by the above general formula (6) (hereinafter referred to as "acid anhydride") is In the following examples, the term "analog" will be used. A part of the structure of the exemplified acid anhydride may be replaced with another structure within the scope of the present invention. This refers to an acid anhydride obtained by converting multiple acid anhydrides. or the substituents have the same number of carbon atoms but have branched chains. Examples of isomeric structures include those in which the substituents bond to the acid anhydride at different positions.

[0126] First, R 9 and R 10 Specific examples of acid anhydrides in which are the same are shown below. R 9 and R 10 Specific examples of acid anhydrides in which the alkyl group is a chain include acetic anhydride, propyl anhydride, and propyl anhydride. Propionic anhydride, butanoic anhydride, 2-methylpropionic anhydride, 2,2-dimethylpropionic anhydride Pionic anhydride, 2-methylbutanoic anhydride, 3-methylbutanoic anhydride, 2,2-dimethylbutanoic anhydride Dimethylbutanoic anhydride, 2,3-dimethylbutanoic anhydride, 3,3-dimethylbutanoic anhydride 2,2,3-trimethylbutanoic anhydride, 2,3,3-trimethylbutanoic anhydride, 2,2,3,3-Tetramethylbutanoic anhydride, 2-ethylbutanoic anhydride, etc., and and their analogues.

[0127] R 9 and R 10 Specific examples of acid anhydrides in which is a cyclic alkyl group include cyclopropane cyclohexane. carboxylic anhydride, cyclopentane carboxylic anhydride, cyclohexane carboxylic anhydride, etc. and their analogues. R 9 and R 10 Specific examples of the acid anhydride in which is an alkenyl group include acrylic anhydride, 2-Methylacrylic anhydride, 3-Methylacrylic anhydride, 2,3-Dimethylacrylic Acid anhydride, 3,3-dimethylacrylic anhydride, 2,3,3-trimethylacrylic anhydride 2-Phenylacrylic anhydride, 3-Phenylacrylic anhydride, 2,3-Diphenyl 3,3-Diphenylacrylic anhydride, 3-Butenoic anhydride, 2- Methyl-3-butenoic anhydride, 2,2-dimethyl-3-butenoic anhydride, 3-methyl-3 -Butenoic anhydride, 2-methyl-3-methyl-3-butenoic anhydride, 2,2-dimethyl- 3-Methyl-3-butenoic anhydride, 3-pentenoic anhydride, 4-pentenoic anhydride, 2- Cyclopentene carboxylic anhydride, 3-cyclopentene carboxylic anhydride, 4-cyclopentene and the like, and their analogues.

[0128] R 9 and R 10 Specific examples of acid anhydrides in which is an alkynyl group include propynoic anhydride, 3-Phenylpropynoic anhydride, 2-Butynoic anhydride, 2-Pentynoic anhydride, 3-Buty pentane, 3-pentane, 4-pentane, and their derivatives Examples include: R 9 and R 10 Specific examples of acid anhydrides in which is an aryl group include benzoic anhydride, 4- Methylbenzoic anhydride, 4-ethylbenzoic anhydride, 4-tert-butylbenzoic anhydride 2-Methylbenzoic anhydride, 2,4,6-trimethylbenzoic anhydride, 1-naphthalene Examples of such anhydrides include 2-naphthalenecarboxylic anhydride, 2-naphthalenecarboxylic anhydride, and their analogues. Can be obtained.

[0129] Also, R 9 and R10 Examples of acid anhydrides in which the halogen atom is substituted are mainly fluorine atoms. Examples of acid anhydrides in which some or all of the fluorine atoms are replaced with salts are given below. Acid anhydrides obtained by substituting hydrogen, bromine, or iodine atoms are also included in the exemplary compounds. It shall be so. R 9 and R 10 As an example of an acid anhydride in which the alkyl group is substituted with halogen atoms, Fluoroacetic anhydride, difluoroacetic anhydride, trifluoroacetic anhydride, 2-fluoroacetic anhydride 2,2-Difluoropropionic anhydride, 2,3-Difluoropropionic anhydride propionic anhydride, 2,2,3-trifluoropropionic anhydride, 2,3,3-trifluoropropionic anhydride 2,2,3,3-Tetrapropionic anhydride, 2,3,3, 3-Tetrapropionic anhydride, 3-fluoropropionic anhydride, 3,3-difluoro Propionic anhydride, 3,3,3-trifluoropropionic anhydride, perfluoropropionic Pionic anhydride and its analogues.

[0130] R 9 and R 10 An example of an acid anhydride in which the cyclic alkyl group is substituted with a halogen atom is 2-Fluorocyclopentane carboxylic anhydride, 3-Fluorocyclopentane carboxylic acid anhydride, 4-fluorocyclopentane carboxylic anhydride, etc., and their derivatives Examples include R 9 and R 10 Examples of acid anhydrides in which is an alkenyl group substituted with a halogen atom include , 2-fluoroacrylic anhydride, 3-fluoroacrylic anhydride, 2,3-difluoro Acrylic anhydride, 3,3-difluoroacrylic anhydride, 2,3,3-trifluoro Acrylic anhydride, 2-(trifluoromethyl)acrylic anhydride, 3-(trifluoromethyl)acrylic anhydride 2,3-bis(trifluoromethyl)acrylic anhydride, 2, 3,3-Tris(trifluoromethyl)acrylic anhydride, 2-(4-fluorophenyl )acrylic anhydride, 3-(4-fluorophenyl)acrylic anhydride, 2,3-bis( 4-fluorophenyl)acrylic anhydride, 3,3-bis(4-fluorophenyl)acrylic 2-fluoro-3-butenoic anhydride, 2,2-difluoro-3-butenoic acid Anhydride, 3-fluoro-2-butenoic anhydride, 4-fluoro-3-butenoic anhydride, 3, 4-Difluoro-3-butenoic anhydride, 3,3,4-trifluoro-3-butenoic anhydride and the like, and their analogues.

[0131] R 9 and R 10 Examples of acid anhydrides in which is an alkynyl group substituted with a halogen atom include , 3-fluoro-2-propynoic anhydride, 3-(4-fluorophenyl)-2-propyne Acid anhydride, 3-(2,3,4,5,6-pentafluorophenyl)-2-propynoic anhydride 4-Fluoro-2-butynoic anhydride, 4,4-difluoro-2-butynoic anhydride, 4 , 4,4-trifluoro-2-butynoic anhydride, and the like, and their analogues. .

[0132] R 9 and R 10 Examples of acid anhydrides in which is an aryl group substituted with a halogen atom include 4-Fluorobenzoic anhydride, 2,3,4,5,6-pentafluorobenzoic anhydride, 4 -trifluoromethylbenzoic anhydride, and the like, and their analogues. R 9 and R 10 Substituents with functional groups such as esters, nitriles, ketones, and ethers Examples of acid anhydrides having the formula (I) include methoxyformic anhydride, ethoxyformic anhydride, methylformic anhydride, Oxalic anhydride, Ethyl oxalic anhydride, 2-cyanoacetic anhydride, 2-oxopropionate Acid anhydrides, 3-oxobutanoic anhydride, 4-acetylbenzoic anhydride, methoxyacetic anhydride Examples of such compounds include 4-methoxybenzoic anhydride, 4-methoxybenzoic anhydride, and their analogues.

[0133] Next, R 9 and R 10 Specific examples of acid anhydrides having different groups are given below. R 9 and R 10 As examples, all combinations of the above-listed examples and their analogues are considered. Representative examples are given below. Examples of combinations of chain alkyl groups include acetic acid propionic anhydride and butane acetate. Acid anhydrides, butanoic acid propionic anhydride, acetic acid 2-methylpropionic anhydride, etc.

[0134] An example of a combination of a chain alkyl group and a cyclic alkyl group is cyclopentaenoic acid. Examples include acetic acid, cyclohexanoic acid anhydride, cyclopentanoic acid, propionic acid anhydride, etc. can be done. Examples of combinations of chain alkyl groups and alkenyl groups include acetic acid, acrylic anhydride, and acetic acid. Acid 3-Methylacrylic Anhydride, Acetic Acid 3-Butenoic Anhydride, Acrylic Acid Propionic Anhydride Things, etc.

[0135] Examples of combinations of chain alkyl groups and alkynyl groups include acetic acid propionate anhydride, acetic acid Acid 2-butynoic anhydride, Acetic acid 3-butynoic anhydride, Acetic acid 3-phenylpropynoic anhydride, propionic acid, propynoic anhydride, etc. Examples of combinations of chain alkyl groups and aryl groups include acetic acid benzoic anhydride, acetic acid 4-benzoic anhydride, and acetic acid 4-benzoic anhydride. -Methylbenzoic anhydride, acetic acid 1-naphthalenecarboxylic anhydride, benzoic acid propionic acid Anhydrous, etc.

[0136] An example of a combination of a chain alkyl group and a hydrocarbon group having a functional group is fluoroacetate. Acetic anhydride, acetic trifluoroacetic anhydride, acetic 4-fluorobenzoic anhydride, fluoro Acetic acid propionic anhydride, alkyl oxalic anhydride, acetic acid 2-cyanoacetic anhydride, acetic acid Acid 2-Oxopropionic Anhydride, Acetic Acid Methoxyacetic Anhydride, Methoxyacetic Acid Propionic Acid Anhydrous, etc.

[0137] Examples of combinations of cyclic alkyl groups include cyclopentanoic acid and cyclohexanoic acid. Water, etc. An example of a combination of a cyclic alkyl group and an alkenyl group is cyclopentane acrylate. Acid anhydride, 3-methylacrylic acid cyclopentanoic anhydride, 3-butenoic acid cyclopentane Acid anhydrides, acrylic acid, cyclohexanoic acid anhydride, etc.

[0138] An example of a combination of a cyclic alkyl group and an alkynyl group is cyclopentane propionate. Acid anhydrides, 2-butynoic acid cyclopentanoic acid anhydride, propynoic acid cyclohexanoic acid anhydride, etc. Examples of combinations of cyclic alkyl groups and aryl groups include benzoic acid, cyclopentanoic acid, and the like. Water, 4-methylbenzoic acid cyclopentanoic acid anhydride, benzoic acid cyclohexanoic acid anhydride, etc.

[0139] An example of a combination of a cyclic alkyl group and a hydrocarbon group having a functional group is fluoroacetic acid. Cyclopentanoic anhydride, Cyclopentanoic trifluoroacetic anhydride, Cyclopentanoic acid 2-Cyanoacetic Anhydride, Cyclopentanoic Acid Methoxyacetic Anhydride, Cyclohexanoic Acid Fluo Acetic anhydride, etc. An example of a combination of alkenyl groups is acrylic acid 2-methylacrylic anhydride. , acrylic acid 3-methylacrylic anhydride, acrylic acid 3-butenoic anhydride, 2-methyl acrylic acid, 3-methylacrylic anhydride, etc.

[0140] An example of a combination of an alkenyl group and an alkynyl group is acrylic acid propynoic anhydride. , acrylic acid 2-butynoic anhydride, 2-methylacrylic acid propynoic anhydride, etc. can be done. Examples of combinations of alkenyl and aryl groups include acrylic acid benzoic anhydride, aryl Examples include acrylic acid 4-methylbenzoic anhydride, 2-methylacrylic acid benzoic anhydride, etc. can be done.

[0141] An example of a combination of an alkenyl group and a hydrocarbon group having a functional group is fluoroacrylic acid. Acrylic acid trifluoroacetic anhydride, acrylic acid 2-cyanoacetic anhydride , acrylic acid methoxyacetic anhydride, 2-methylacrylic acid fluoroacetic anhydride, etc. Can be obtained. Examples of combinations of alkynyl groups include propynoic acid 2-butynoic anhydride, propynoic acid 2-butynoic anhydride, Examples of such anhydrides include 2-butynoic acid and 3-butynoic acid anhydride.

[0142] Examples of combinations of alkynyl and aryl groups include benzoic acid propynoic anhydride, 4 -methylbenzoic acid propynoic anhydride, benzoic acid 2-butynoic anhydride, etc. An example of a combination of an alkynyl group and a hydrocarbon group having a functional group is fluoropropionate. Oroacetic anhydride, Propynoic acid trifluoroacetic anhydride, Propynoic acid 2-cyanoacetic anhydride , propynoic acid methoxyacetic anhydride, 2-butynoic acid fluoroacetic anhydride, etc. .

[0143] Examples of combinations of aryl groups include benzoic acid 4-methylbenzoic anhydride, benzoic 1-Naphthalenecarboxylic Anhydride, 4-Methylbenzoic Acid 1-Naphthalenecarboxylic Acid Water, etc. An example of a combination of an aryl group and a hydrocarbon group having a functional group is fluorobenzoate. Acetic Anhydride, Benzoic Acid Trifluoroacetic Anhydride, Benzoic Acid 2-Cyanoacetic Anhydride, Benzoic Acid Examples of the methoxyacetic anhydride include 4-methylbenzoic acid and fluoroacetic anhydride.

[0144] An example of a combination of hydrocarbon groups having functional groups is fluoroacetate trifluoroacetate. Acetic anhydride, fluoroacetic acid, 2-cyanoacetic anhydride, fluoroacetic acid, methoxyacetic anhydride, trifluoroacetic acid, 2-cyanoacetic anhydride, etc. Among the above-mentioned acid anhydrides forming a chain structure, preferred are Acetic anhydride, Propionic anhydride, 2-methylpropionic anhydride, Cyclopentasiloxane carboxylic anhydride, cyclohexanecarboxylic anhydride, acrylic anhydride, 2-methylacrylic anhydride, etc. Acrylic anhydride, 3-methylacrylic anhydride, 2,3-dimethylacrylic anhydride, 3, 3-Dimethylacrylic anhydride, 3-butenoic anhydride, 2-methyl-3-butenoic anhydride , Propynoic anhydride, 2-butynoic anhydride, Benzoic anhydride, 2-methylbenzoic anhydride , 4-methylbenzoic anhydride, 4-tert-butylbenzoic anhydride, trifluoroacetic acid Anhydride, 3,3,3-trifluoropropionic anhydride, 2-(trifluoromethyl) Acrylic anhydride, 2-(4-fluorophenyl)acrylic anhydride, 4-fluorobenzoic acid Acid anhydrides, 2,3,4,5,6-pentafluorobenzoic anhydride, methoxyformic anhydride, Ethoxyformic anhydride, and more preferably Acrylic anhydride, 2-methylacrylic anhydride, 3-methylacrylic anhydride, benzoic acid Benzoic anhydride, 2-methylbenzoic anhydride, 4-methylbenzoic anhydride, 4-tert- 4-Fluorobenzoic anhydride, 2,3,4,5,6-pentafluorobenzoic anhydride b) benzoic anhydride, methoxyformic anhydride, and ethoxyformic anhydride.

[0145] These compounds form bonds with lithium oxalate salts appropriately and have excellent durability. By forming a coating, the charge / discharge rate characteristics, input / output characteristics, and impedance, especially after durability testing, This is preferable from the viewpoint of improving the thermal properties. Next, R 9 and R 10 Examples of acid anhydrides in which the and are bonded to each other to form a cyclic structure are as follows: They are listed below.

[0146] First, R 9 and R 10 and a specific example of an acid anhydride in which the and are bonded to each other to form a five-membered ring structure. Examples include succinic anhydride, 4-methylsuccinic anhydride, 4,4-dimethylsuccinic anhydride, 4,5-Dimethylsuccinic Anhydride, 4,4,5-Trimethylsuccinic Anhydride, 4,4,5 ,5-Tetramethylsuccinic anhydride, 4-Vinylsuccinic anhydride, 4,5-Divinylsuccinic Succinic anhydride, 4-phenylsuccinic anhydride, 4,5-diphenylsuccinic anhydride, 4,4 -Diphenylsuccinic anhydride, citraconic anhydride, maleic anhydride, 4-methylmaleic anhydride Maleic anhydride, 4,5-dimethylmaleic anhydride, 4-phenylmaleic anhydride, 4, 5-Diphenylmaleic Anhydride, Itaconic Anhydride, 5-Methyl Itaconic Anhydride, 5 ,5-Dimethylitaconic anhydride, Phthalic anhydride, 3,4,5,6-Tetrahydrophthalic anhydride Acid anhydrides and their analogues are included.

[0147] R 9 and R 10 Examples of acid anhydrides in which the and are bonded to each other to form a six-membered ring structure include , Cyclohexane-1,2-dicarboxylic anhydride, 4-cyclohexene-1,2-dicarboxylic acid Examples of the anhydride include benzyl anhydride, glutaric anhydride, and the like, and their analogues. R 9 and R 10 and are bonded to each other to form another cyclic structure. Examples include 5-norbornene-2,3-dicarboxylic anhydride, cyclopentane tetracarbo dianhydride, pyromellitic anhydride, diglycolic anhydride, etc., and their analogues Some examples include:

[0148] R 9 and R 10 are bonded to each other to form a ring structure and are substituted with halogen atoms. Specific examples of the acid anhydrides used include 4-fluorosuccinic anhydride, 4,4-difluorosuccinic anhydride, Succinic anhydride, 4,5-difluorosuccinic anhydride, 4,4,5-trifluorosuccinic acid anhydride Water, 4,4,5,5-tetrafluorosuccinic anhydride, 4-fluoromaleic anhydride , 4,5-Difluoromaleic Anhydride, 5-Fluoroitaconic Anhydride, 5,5-Difluoro fluoroleutaconic anhydride, and the like, and their analogues.

[0149] The above R 9 and R 10 Among the acid anhydrides having the bond, Succinic anhydride, 4-methylsuccinic anhydride, 4-vinylsuccinic anhydride, 4-phenyl Succinic anhydride, citraconic anhydride, maleic anhydride, 4-methylmaleic anhydride, 4-Phenylmaleic anhydride, Itaconic anhydride, 5-Methylitaconic anhydride, Glu Thalic anhydride, phthalic anhydride, cyclohexane-1,2-dicarboxylic anhydride, 5-nor Bornene-2,3-dicarboxylic anhydride, Cyclopentanetetracarboxylic dianhydride, Romelic anhydride, 4-fluorosuccinic anhydride, 4-fluoromaleic anhydride, 5 -fluoroitaconic anhydride, and more preferably Succinic anhydride, 4-methylsuccinic anhydride, 4-vinylsuccinic anhydride, citraconic acid Anhydride, Cyclohexane-1,2-dicarboxylic acid anhydride, 5-Norbornene-2,3-di Carboxylic acid anhydrides, cyclopentanetetracarboxylic dianhydride, pyromellitic anhydride, 4-fluorosuccinic anhydride. These compounds are suitably lithium oxalate salts. By forming a highly durable coating with the This is preferable because it improves the

[0150] There is no limitation on the molecular weight of the carboxylic acid anhydride, as long as the effect of the present invention is not significantly impaired. It is optional, but usually 90 or more, preferably 95 or more, while usually 300 or less, preferably If the molecular weight of the carboxylic acid anhydride is within the above range, the viscosity of the electrolyte is improved. The temperature rise can be suppressed, and the coating density can be optimized to appropriately improve durability. Cut.

[0151] The method for producing the carboxylic acid anhydride is not particularly limited, and any known method can be selected. The carboxylic acid anhydride described above can be produced by the non-aqueous electrolytic The liquid may contain any one of the above-mentioned compounds alone or any combination and ratio of two or more of the above-mentioned compounds. They may be used together. In addition, there is no particular limitation on the content of the carboxylic acid anhydride in the nonaqueous electrolyte solution of the present invention. As long as the effect of the present invention is not significantly impaired, it is optional, but for the non-aqueous electrolyte of the present invention, 0.01% by mass or more, preferably 0.1% by mass or more, and usually 5% by mass or less, preferably It is desirable to include the carboxylic acid anhydride at a concentration of 3 mass % or less. Within this range, the effect of improving cycle characteristics is easily achieved, and the reactivity is favorable. This makes it easier to improve battery characteristics.

[0152] <2-3-7. Overcharge protection agent> In the non-aqueous electrolyte of the present invention, when the non-aqueous electrolyte secondary battery is in an overcharged state, In order to effectively prevent the battery from exploding or catching fire, an overcharge protection agent can be used. Overcharge inhibitors include biphenyl, alkylbiphenyl, terphenyl, and terphenyl. partially hydrogenated benzene, cyclohexylbenzene, t-butylbenzene, t-amylbenzene , diphenyl ether, dibenzofuran, diphenylcyclohexane, 1,1,3-triphenyl Aromatic compounds such as methyl-3-phenylindan; 2-fluorobiphenyl, o-cyclo The above aromatic compounds such as hexylfluorobenzene and p-cyclohexylfluorobenzene Partially fluorinated compounds of 2,4-difluoroanisole, 2,5-difluoroanisole, 2 Fluorine-containing anisole such as 3,6-difluoroanisole and 3,5-difluoroanisole Compounds, etc.; 3-propylphenyl acetate, 2-ethylphenyl acetate, benzyl phenyl acetate, methyl phenyl acetate, benzyl acetate, phenethyl phenyl Aromatic acetates such as diphenyl carbonate, methyl phenyl carbonate, etc. Among them, biphenyl, alkylbiphenyl, etc. terphenyl, partially hydrogenated terphenyl, cyclohexylbenzene, t-butyl Benzene, t-amylbenzene, diphenyl ether, dibenzofuran, diphenyl cyclohexane 1,1,3-trimethyl-3-phenylindan, 3-propylphenyla acetate, 2-ethylphenyl acetate, benzyl phenyl acetate, methyl phenyl acetate, benzyl acetate, phenethyl phenyl acetate, diphenyl carbo These may be used alone or in combination. The above may be used in combination. When two or more types are used in combination, cyclohexylbenzene and t- In combination with butylbenzene or t-amylbenzene, biphenyl, alkylbiphenyl terphenyl, partially hydrogenated terphenyl, cyclohexylbenzene, t-butyl At least one selected from aromatic compounds not containing oxygen, such as benzene and t-amylbenzene. At least one of the above and at least one of the above oxygen-containing aromatic compounds such as diphenyl ether and dibenzofuran. It is preferable to use at least one of these in combination in terms of the balance between overcharge prevention properties and high-temperature storage properties. stomach.

[0153] The content of the overcharge inhibitor is not particularly limited, and may be any amount as long as it does not significantly impair the effects of the present invention. The content of the overcharge inhibitor is usually 0.1% by mass or more in 100% by mass of the non-aqueous electrolyte. , preferably 0.2% by mass or more, more preferably 0.3% by mass or more, and further preferably 0. 0.5% by weight or more, and usually 5% by weight or less, preferably 4.8% by weight or less, more preferably The content is preferably 4.5 mass % or less. Within this range, the effect of the overcharge inhibitor is sufficiently exhibited. In addition, the battery characteristics such as high-temperature storage characteristics are improved.

[0154] <2-3-8. Other Auxiliaries> Other known auxiliary agents may be used in the non-aqueous electrolyte solution of the present invention. As for the following: Erythritan carbonate, spiro-bis-dimethylene carbonate, methoxyethyl - Carbonate compounds such as methyl carbonate; Methyl-2-propynyl oxalate, Ethyl-2-propynyl oxalate, Bis( 2-propynyl)oxalate, 2-propynyl acetate, 2-propynyl formate , 2-propynyl methacrylate, di(2-propynyl) glutarate, methyl-2-propynyl Propynyl carbonate, ethyl-2-propynyl carbonate, bis(2-propynyl) Carbonate, 2-butyne-1,4-diyl-dimethanesulfonate, 2-butyne-1, 4-Diyl-diethanesulfonate, 2-butyne-1,4-diyl-diformate, 2- Butyne-1,4-diyl-diacetate, 2-Butyne-1,4-diyl-dipropionate 4-Hexadiyn-1,6-diyl-dimethanesulfonate, 2-Propynyl-methanate Methanesulfonate, 1-methyl-2-propynyl-methanesulfonate, 1,1-dimethyl -2-propynyl-methanesulfonate, 2-propynyl-ethanesulfonate, 2-propynyl Propynyl vinyl sulfonate, 2-propynyl-2-(diethoxyphosphoryl)acetate 1-Methyl-2-propynyl-2-(diethoxyphosphoryl)acetate, 1,1 -Dimethyl-2-propynyl-2-(diethoxyphosphoryl)acetate and other triple bond-containing Compound;

[0155] 2,4,8,10-Tetraoxaspiro[5.5]undecane, 3,9-divinyl-2 , spiro compounds such as 4,8,10-tetraoxaspiro[5.5]undecane; Ethylene sulfite, methyl fluorosulfonate, ethyl fluorosulfonate, meth Methyl methanesulfonate, ethyl methanesulfonate, busulfan, sulfolene, diphenyl Sulfone, N,N-dimethylmethanesulfonamide, N,N-diethylmethanesulfonamide amide, trimethylsilyl methylsulfate, trimethylsilyl ethylsulfate, 2-propynyl- Sulfur-containing compounds such as trimethylsilyl sulfate;

[0156] 2-Isocyanatoethyl acrylate, 2-Isocyanatoethyl methacrylate, 2- Isocyanatoethyl crotonate, 2-(2-isocyanatoethoxy)ethyl acrylate 2-(2-isocyanatoethoxy)ethyl methacrylate, 2-(2-isocyanato isocyanate compounds such as (ethoxy)ethyl crotonate; 1-Methyl-2-pyrrolidinone, 1-Methyl-2-piperidone, 3-Methyl-2-oxo Sazolidinone, 1,3-dimethyl-2-imidazolidinone and N-methylsuccinimide Nitrogen-containing compounds such as;

[0157] Hydrocarbon compounds such as heptane, octane, nonane, decane, cycloheptane, etc.; Fluorobenzene, difluorobenzene, hexafluorobenzene, benzotrifluorobenzene Lid, Pentafluorophenyl methanesulfonate, Pentafluorophenyl triflate pentafluorophenyl acetate, pentafluorotrifluoroacetate Fluorine-containing aromatic compounds such as methylpentafluorophenyl carbonate and methylpentafluorophenyl carbonate; Tris(trimethylsilyl) borate, tris(trimethoxysilyl) borate, tris(trimethylsilyl) phosphate Tris(trimethylsilyl), tris(trimethoxysilyl) phosphate, dimethoxyaluminum Dimethoxytrimethoxysilane, diethoxyaluminoxytriethoxysilane, dipropoxyaluminoxytriethoxysilane Aluminoxytriethoxysilane, Dibutoxyaluminoxytrimethoxysilane, Dibutoxy Sialuminoxytriethoxysilane, Titanium tetrakis(trimethylsiloxide), Titanium Tetrakis(triethylsiloxide), Silane compounds such as;

[0158] 2-(Methanesulfonyloxy)propionic acid 2-propynyl, 2-(methanesulfonyl 2-(methanesulfonyloxy)propionic acid 2-methyl Ethyl, 2-propynyl methanesulfonyloxyacetate, 2-propynyl methanesulfonyloxyacetate Ester compounds such as methyl and 2-ethyl methanesulfonyloxyacetate; Lithium ethyl methyloxycarbonyl phosphonate, Lithium ethyl ethyl oxycarbonyl Carbonylphosphonate, Lithium Ethyl-2-Propynyloxycarbonylphosphonate , lithium ethyl-1-methyl-2-propynyloxycarbonylphosphonate, lithium Lithium ions such as methyl-1,1-dimethyl-2-propynyloxycarbonylphosphonate Mu salt; These may be used alone or in combination of two or more. Adding auxiliary agents improves the capacity retention and cycle characteristics after high-temperature storage. can be done.

[0159] The content of other auxiliary agents is not particularly limited, and may be any amount as long as it does not significantly impair the effects of the present invention. The content of other auxiliary agents is usually 0.01% by mass or less in 100% by mass of the non-aqueous electrolyte. The content is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, and usually The content is 5% by mass or less, preferably 3% by mass or less, and more preferably 1% by mass or less. If this is the case, the effects of other auxiliary agents can be fully expressed, and the battery characteristics such as high-load discharge characteristics can be improved. Improve.

[0160] The nonaqueous electrolyte described above is a nonaqueous electrolyte secondary battery according to one embodiment of the present invention. These include those present inside energy devices such as lithium salts and The components of the non-aqueous electrolyte solution, such as the solvent and auxiliary agent, are separately synthesized and substantially isolated, and then the non-aqueous electrolyte solution is extracted. The non-aqueous electrolyte was prepared and injected into a separately assembled battery by the method described below. In the case of a non-aqueous electrolyte in an electrolyte secondary battery, or when the components of the non-aqueous electrolyte of the present invention are individually The nonaqueous electrolyte secondary battery of the present invention is produced by mixing the nonaqueous electrolyte in the battery. In order to obtain the same composition as the non-aqueous electrolyte solution of the present invention, the compounds constituting the non-aqueous electrolyte solution of the present invention are It is also possible to generate the electrolyte in a non-aqueous electrolyte secondary battery to obtain the same composition as the non-aqueous electrolyte of the present invention. This shall be included.

[0161] <2-4. Method for producing non-aqueous electrolyte> The non-aqueous electrolyte of the present invention is a non-aqueous solvent containing an electrolyte and a P(OR)5 structural formula. It can be prepared by dissolving the compound to be used and, if necessary, the aforementioned "auxiliary agent" etc. Cut. When preparing the non-aqueous electrolyte solution, the raw materials of the non-aqueous electrolyte solution, i.e., lithium salt, etc. The electrolyte, the compound represented by the structural formula P(OR)5, the non-aqueous solvent, the auxiliary agent, etc. must be dehydrated in advance. The degree of dehydration is usually 50 ppm or less, preferably 30 ppm or less. It is recommended to dehydrate until the following:

[0162] By removing the water from the non-aqueous electrolyte, the electrolysis of water, the reaction of water with lithium metal, The hydrolysis of the lithium salt is less likely to occur. There are no particular limitations on the method of dehydration, but for example, If the object to be dehydrated is a liquid such as a non-aqueous solvent, a desiccant such as a molecular sieve can be used. If the object to be dehydrated is a solid such as an electrolyte, it is recommended to heat it to a temperature below the temperature at which decomposition occurs. Just let it dry.

[0163] <3. Energy devices using non-aqueous electrolytes> The energy device using the nonaqueous electrolyte of the present invention is capable of absorbing or releasing metal ions. The battery is provided with a plurality of electrodes and the non-aqueous electrolyte solution of the present invention described above. The types of devices include primary batteries, secondary batteries, and lithium-ion capacitors. Specific examples include metal ion capacitors. Among them, primary batteries and secondary batteries are preferred. A non-aqueous battery used in these energy devices is preferable, and a secondary battery is particularly preferable. The electrolyte may be a so-called gel electrolyte, which is a pseudo-solidified electrolyte made of polymers or fillers. The energy device will now be described.

[0164] <3-1. Nonaqueous electrolyte secondary battery> <3-1-1. Battery configuration> A non-aqueous electrolyte secondary battery according to one embodiment of the present invention (hereinafter also referred to as the non-aqueous secondary battery of the present invention) The structure of the battery other than the non-aqueous electrolyte solution is the same as that of a conventional non-aqueous electrolyte secondary battery. The same is true for the battery, and the battery is usually charged through a porous membrane (separator) impregnated with the non-aqueous electrolyte of the present invention. The positive and negative electrodes are laminated together and housed in a case (outer packaging). Therefore, the shape of the non-aqueous electrolyte secondary battery of the present invention is not particularly limited, and may be a cylindrical type, a square type, or the like. The shape may be any of a small, laminated, coin-shaped, large, etc.

[0165] <3-1-2. Non-aqueous electrolyte> As the non-aqueous electrolyte solution, the non-aqueous electrolyte solution of the present invention described above is used. Within the scope of the present invention, other non-aqueous electrolyte solutions may be mixed with the non-aqueous electrolyte solution of the present invention. It is also possible to use it as such.

[0166] <3-1-3. Negative electrode> The negative electrode active material used in the negative electrode is one that can electrochemically absorb and release metal ions. As long as the material is a carbonaceous material, a metal compound material, a lithium and titanium-containing metal composite oxide materials. These may be used alone. Two or more kinds may be used in any combination. Among these, carbonaceous materials and metal compound-based materials are preferred. Among the metal compound-based materials, A material containing silicon is preferred, and therefore, the negative electrode active material is a carbonaceous material and silicon. Materials containing are particularly preferred.

[0167] <3-1-3-1. Carbonaceous material> The carbonaceous material used as the negative electrode active material is not particularly limited, but may be any of the following (A) to (C): (E) is selected from the following two batteries that have a good balance between initial irreversible capacity and high current density charge / discharge characteristics. This is preferable because it provides a secondary battery. (A) Natural graphite (a) Artificial carbonaceous materials and artificial graphite materials are heated at temperatures between 400°C and 3200°C at least once. Carbonaceous material obtained by heat treatment (C) The negative electrode active material layer is made of at least two types of carbonaceous matter having different crystallinity, and / or a carbonaceous material having an interface where carbonaceous materials of different crystallinity are in contact with each other. (D) The negative electrode active material layer is made of at least two types of carbonaceous matter having different orientations, and / or a carbonaceous material having an interface where carbonaceous materials of different orientations are in contact with each other. The carbonaceous materials (a) to (d) may be used alone or in any combination of two or more. They may be used in combination in any combination and ratio.

[0168] Specific examples of the artificial carbonaceous material or artificial graphite material in (a) above include natural graphite, Coal coke, petroleum coke, coal pitch, petroleum pitch and the oxidation of these pitches Processed; Needle coke, pitch coke and partially graphitized carbon materials; Pyrolysis products of organic matter such as furnace black, acetylene black, and pitch-based carbon fibers; Carbonizable organic matter and the carbonized products thereof; and Carbonizable organic matter is low molecular weight compounds such as benzene, toluene, xylene, quinoline, and n-hexane. Examples of the carbon-containing carbon material include carbonized carbon particles dissolved in an organic solvent. In addition, the above carbonaceous materials (A) to (D) are all publicly known, and their manufacturing methods are These are well known to those skilled in the art and can also be purchased commercially.

[0169] <3-1-3-2. Metal compound materials> Metal compound materials that can absorb and release lithium are used as negative electrode active materials. If any, it is not particularly limited, and may be a single metal or an alloy that forms an alloy with lithium, or Compounds such as oxides, carbides, nitrides, silicides, sulfides, and phosphides of the above-mentioned metals can be used. Examples of metal compounds include Ag, Al, Ba, Bi, Cu, Ga, Ge, In, Ni, P, Compounds containing metals such as Pb, Sb, Si, Sn, Sr, and Zn are examples. It is preferable that the element is a metal or an alloy that forms an alloy with lithium, and the element is a group 13 metal of the periodic table. or Group 14 metals and metalloid elements (i.e., excluding carbon. In the following, metals and metalloids are It is more preferable that the material contains silicon (S i), tin (Sn) or lead (Pb) (hereinafter, these three elements are referred to as "SSP metal elements"). (SSP) elemental metals or alloys containing these elements, or It is preferable that the compound is a compound containing a metal element. Particularly preferable is a compound containing silicon. These may be used alone or in any combination and ratio of two or more. may be used.

[0170] <3-1-3-3. Lithium-containing metal composite oxide materials> The lithium-containing metal composite oxide material used as the negative electrode active material is As long as it can be stored and released, there is no particular limitation, but a lithium-containing composite metal oxide containing titanium is preferred. The material is preferably a composite oxide of lithium and titanium (hereinafter, "lithium titanium composite oxide"). In other words, lithium tin oxide having a spinel structure is particularly preferred. The titanium composite oxide is contained in the negative electrode active material for a lithium ion non-aqueous electrolyte secondary battery. This is particularly preferable since the output resistance of the secondary battery is significantly reduced.

[0171] In addition, the lithium and titanium in the lithium titanium composite oxide are not mixed with other metal elements, such as Na. , K, Co, Al, Fe, Ti, Mg, Cr, Ga, Cu, Zn and Nb Substitution with at least one selected element is also preferred. A lithium titanium composite oxide preferable as the negative electrode active material is represented by the following general formula (7): Lithium titanium composite oxide is an example of such a material.

[0172] Li x Ti y M z O4(7) (In general formula (7), M is Na, K, Co, Al, Fe, Ti, Mg, Cr, Ga, Cu In addition, the general formula (7) represents at least one element selected from the group consisting of Zn and Nb. ) 0.7≦x≦1.5, 1.5≦y≦2.3, 0≦z≦1.6. This is preferable because the structure is stable when doping and dedoping the ions.)

[0173] <2-1-3-4. Composition, properties and preparation method of negative electrode> The negative electrode containing the above-mentioned active material, the electrode forming method, and the current collector are based on known technical configurations. However, one or more of the following items (i) to (vi) may be adopted: It is desirable to satisfy both of these requirements at the same time.

[0174] (i) Preparation of negative electrode The negative electrode may be produced by any known method as long as it does not significantly limit the effect of the present invention. For example, the negative electrode active material may be mixed with a binder, a solvent, and, if necessary, a thickener, a conductive agent, etc. Adding materials, fillers, etc., to make a slurry of negative electrode material, which is then applied to a current collector and dried. By pressing the negative electrode active material layer, a negative electrode active material layer can be formed.

[0175] (ii) Current collector As the current collector for holding the negative electrode active material, any known current collector can be used. The current collector of the electrode may be, for example, aluminum, copper, nickel, stainless steel, or nickel-metal. Among them, copper is particularly preferable from the viewpoints of ease of processing and cost. In addition, when the collector is made of a metal material, the shape of the collector may be, for example, a metal foil, a metal cylinder, a metal Examples include coils, metal plates, metal thin films, expanded metal, punched metal, and foamed metal. Among them, a metal thin film is preferable, a copper foil is more preferable, and a rolling method is even more preferable. and electrolytic copper foil made by the electrolytic method.

[0176] (iii) Ratio of thickness of current collector to that of negative electrode active material layer The thickness ratio of the current collector and the negative electrode active material layer is not particularly limited, but The value of "(thickness of the negative electrode active material layer on one side immediately before the current collector) / (thickness of the current collector)" is preferably 150 or less. It is preferably 0.1 or more, more preferably 20 or less, particularly preferably 10 or less, It is more preferably 0.4 or more, and particularly preferably 1 or more. When the ratio of the thickness of the current collector to the thickness of the negative electrode active material layer exceeds the above range, the high current density charging and discharging of the secondary battery becomes difficult. When the current collector is charged, it may generate heat due to Joule heat. The volume ratio of the current collector to the negative electrode active material increases, and the capacity of the secondary battery may decrease.

[0177] (iv) Electrode density The electrode structure when the negative electrode active material is made into an electrode is not particularly limited, and the negative electrode active material is present on a current collector. The density of the negative electrode active material is 1 g cm -3 More than 1.2 g cm is preferable. -3 More is better Preferably, 1.3g cm -3 More than 4g cm is more preferable. -3 The following is preferred: , 3g·cm -3 Less than 2.5 g cm is preferable. -3 Less than or equal to 1.7 is more preferable. g cm -3 The following is particularly preferred: The density of the negative electrode active material present on the current collector is within the above range. If the negative electrode active material particles are within this range, they are less likely to be destroyed, and the initial irreversible capacity of the secondary battery increases. High current density charge / discharge characteristics due to reduced permeability of non-aqueous electrolyte near the current collector / negative electrode active material interface Furthermore, the conductivity between the negative electrode active materials can be secured, and the battery resistance can be reduced. This allows for greater capacity per unit volume without increasing the size of the storage space.

[0178] (v) Binders, solvents, etc. The slurry for forming the negative electrode active material layer is usually prepared by mixing the negative electrode active material with a solvent. It is prepared by adding a mixture of a binder, a thickener, etc. The binder that binds the negative electrode active material is the non-aqueous electrolyte or the solvent used in the electrode manufacturing process. There are no particular limitations on the material as long as it is stable to the solvent.

[0179] Specific examples include polyethylene, polypropylene, and polyethylene terephthalate. Resins such as polymethyl methacrylate, aromatic polyamide, cellulose, and nitrocellulose system polymer; SBR (styrene-butadiene rubber), isoprene rubber, butadiene rubber, fluororubber Rubber-like materials such as NBR (acrylonitrile butadiene rubber) and ethylene propylene rubber polymer; Styrene-butadiene-styrene block copolymer or its hydrogenated derivatives; EPDM (ethylene-propylene-diene terpolymer), styrene-ethylene-butadiene Diene-styrene copolymer, styrene-isoprene-styrene block copolymer or its Thermoplastic elastomeric polymers such as hydrogenated products; Syndiotactic-1,2-polybutadiene, polyvinyl acetate, ethylene vinyl acetate Soft resinous polymers such as propylene copolymers and propylene-α-olefin copolymers; Polyvinylidene fluoride, Polytetrafluoroethylene, Fluorinated polyvinylidene fluoride Fluorine-based polymers such as polytetrafluoroethylene-ethylene copolymers; Polymer composition having ionic conductivity for alkali metal ions (especially lithium ions) These may be used alone or in any combination or ratio of two or more. They may be used in combination at the same rate.

[0180] The solvent for forming the slurry contains a negative electrode active material, a binder, and, if necessary, Any type of solvent that can dissolve or disperse the thickener and conductive material used in the process is acceptable. There is no particular limitation on the solvent, and either an aqueous solvent or an organic solvent may be used. Examples of the aqueous solvent include water and alcohol, and examples of the organic solvent include N-methylpyrrolidone (NMP), dimethylformamide, dimethylacetamide, methyl ethyl ketone, cyclohexanone, methyl acetate, methyl acrylate, diethyl triamine , N,N-dimethylaminopropylamine, tetrahydrofuran (THF), toluene , acetone, diethyl ether, dimethylacetamide, hexamethylphosphatamide , dimethyl sulfoxide, benzene, xylene, quinoline, pyridine, methylnaphthalene Examples of the solvent include hexane and the like.

[0181] In particular, when using water-based solvents, dispersants, etc., are added in addition to the thickener, and latex such as SBR is It is preferable to form a slurry using a powder. These solvents may be used alone or in any combination and ratio of two or more. may be used in combination. The ratio of the binder to 100 parts by mass of the negative electrode active material is preferably 0.1 parts by mass or more, More preferably 0.5 parts by mass or more, even more preferably 0.6 parts by mass or more, and even more preferably 20 parts by mass or more. Preferably, the amount is 15 parts by mass or less, more preferably 10 parts by mass or less, and more preferably 8 parts by mass or less. It is particularly preferable that the ratio of the binder to the negative electrode active material is within the above range. Since the ratio of binder that does not contribute to the battery capacity does not increase, the battery capacity is less likely to decrease. Furthermore, the strength of the negative electrode is less likely to decrease.

[0182] In particular, the slurry used to form the negative electrode is mainly made of rubber-like polymers such as SBR. When the binder is contained in the negative electrode, the ratio of the binder to 100 parts by mass of the negative electrode active material is 0.1 parts by mass or less. parts by mass or more is preferable, 0.5 parts by mass or more is more preferable, and 0.6 parts by mass or more is even more preferable. Also, 5 parts by mass or less is preferable, 3 parts by mass or less is more preferable, and 2 parts by mass or less is even more preferable. I wish. In addition, the slurry contains fluorine-based polymers such as polyvinylidene fluoride as its main component. When the binder is contained, the ratio of the binder to 100 parts by mass of the negative electrode active material is 1 part by mass or more. is preferable, 2 parts by mass or more is more preferable, 3 parts by mass or more is even more preferable, and 15 parts by mass or more is even more preferable. parts by mass or less, more preferably 10 parts by mass or less, and even more preferably 8 parts by mass or less.

[0183] A thickener is usually used to adjust the viscosity of the slurry. Although there is no limitation, specific examples include carboxymethylcellulose, methylcellulose, hydroxymethylcellulose, etc. Dimethyl cellulose, ethyl cellulose, polyvinyl alcohol, oxidized starch, phosphate Examples of the additives include starch, casein, and salts thereof. These may be used alone or in combination. Two or more kinds may be used in any combination and ratio.

[0184] When a thickener is used, the ratio of the thickener to 100 parts by mass of the negative electrode active material is usually 0.1 parts by mass. The amount is preferably 0.5 parts by mass or more, more preferably 0.6 parts by mass or more. The ratio is usually 5 parts by mass or less, preferably 3 parts by mass or less, and more preferably 2 parts by mass or less. When the ratio of the thickener to the negative electrode active material is within the above range, the coating property of the slurry is improved. Furthermore, the ratio of the negative electrode active material in the negative electrode active material layer is appropriate, and the battery This makes it difficult for the problems of capacity reduction and resistance between negative electrode active materials to occur.

[0185] (vi) Area of ​​negative plate The area of ​​the negative electrode plate is not particularly limited, but is set to be slightly larger than the opposing positive electrode plate. It is preferable to design the battery so that the electrode plate does not protrude beyond the negative electrode plate. From the perspective of suppressing the cycle life when repeatedly charging and discharging the battery and deterioration due to high temperature storage, Making the area as close as possible to the positive electrode will increase the proportion of electrodes that work more uniformly and effectively. This is preferable because it improves the characteristics. In particular, when the secondary battery is used at a large current, this load The design of the plate area is important.

[0186] <3-1-4. Positive electrode> The positive electrode used in the nonaqueous electrolyte secondary battery of the present invention will now be described. <3-1-4-1. Positive electrode active material> The positive electrode active material used in the positive electrode will be described below.

[0187] (1) Composition The positive electrode active material is preferably one that can electrochemically absorb and release metal ions. Although there is no limitation, for example, a material capable of electrochemically absorbing and releasing lithium ions is preferable. Materials containing lithium and at least one transition metal are preferred. Lithium-transition metal composite oxides, lithium-containing transition metal phosphate compounds, lithium-containing transition metal silicates Examples of the borate include an acid compound and a lithium-containing transition metal borate compound.

[0188] The transition metal of the lithium transition metal composite oxide is V, Ti, Cr, Mn, Fe, C Preferred are lithium, nickel, copper, etc., and specific examples of the composite oxides include lithium ions such as LiCoO2. Lithium-cobalt composite oxides, lithium-nickel composite oxides such as LiNiO2, LiMn Lithium manganese oxides such as LiO2, LiMn2O4, and Li2MnO4 Some of the transition metal atoms that make up the main part of the lithium-transition metal composite oxide are replaced with Al, Ti, V, Cr, M n, Fe, Co, Li, Ni, Cu, Zn, Mg, Ga, Zr, Si, Nb, Mo, Sn , and those substituted with other metals such as W.

[0189] Specific examples of the substituted ones include LiNi 0.5 Mn 0.5 O2, LiNi 0.85 Co 0.10 Al 0.05 O2, LiNi 0.33 Co 0.33 Mn 0.33 O 2. LiMn2O4, LiMn 1.8 Al 0.2 O4, Li 1.1 Mn 1.9 Al 0.1 O4, LiMn 1.5 Ni 0.5 Examples include O4. Among them, a composite oxide containing lithium, nickel and cobalt is more preferable. A composite oxide containing copper and nickel has a large capacity when used at the same potential. This is because it is possible.

[0190] On the other hand, cobalt is a scarce and expensive metal, and high capacity is required for automotive applications, etc. In the case of large batteries, the amount of active material used is large, so in terms of cost, cheaper transition It is also desirable to use manganese as the main transition metal. Cobalt-manganese composite oxide is more preferable. Among them, From the viewpoint of meeting the high demand, lithium-ion batteries with reduced cobalt and increased nickel content are being developed. Lithium-nickel-cobalt-manganese composite oxide is particularly preferred. 0. 5Co 0.2 Mn 0.3 O2 and LiNi 0.6 Co 0.2 Mn 0.2 O2 and LiNi 0. 8Co 0.1 Mn 0.1 O2 is a particularly preferred example.

[0191] In addition, considering the stability of the compound and the procurement costs due to the ease of production, spinel Lithium manganese composite oxides having a structure of the above type are also preferred. LiMn2O4, LiMn 1.8 Al 0.2 O4, Li 1.1 Mn 1.9 Al 0.1 O4 , LiMn 1.5 Ni 0.5 O4 and the like can also be mentioned as a preferred specific example. The transition metal of the lithium-containing transition metal phosphate compound is V, Ti, Cr, Mn, F. Preferred are Fe, Co, Ni, Cu, etc., and specific examples of the phosphate compound include LiF Iron phosphates such as ePO4, Li3Fe2(PO4)3, LiFeP2O7, LiCoPO4 Cobalt phosphates such as LiMnPO4, manganese phosphates such as LiMnPO4, and lithium transition metal phosphates such as LiMnPO4. Some of the transition metal atoms that are the main components of the acid compound are Al, Ti, V, Cr, Mn, Fe, Co, Other metals such as Li, Ni, Cu, Zn, Mg, Ga, Zr, Si, Nb, Mo, Sn, W, etc. and the like.

[0192] The transition metal of the lithium-containing transition metal silicate compound is preferably V, Ti, Cr, Mn, Fe, Co, Ni, Cu, etc. are preferred. Specific examples of the silicate compound include, for example, L Iron silicates such as i2FeSiO4, cobalt silicates such as Li2CoSiO4, Some of the transition metal atoms that make up the main part of the lithium transition metal silicate compound are replaced with Al, Ti, V, or Cr. , Mn, Fe, Co, Li, Ni, Cu, Zn, Mg, Ga, Zr, Si, Nb, Mo, Examples include those in which Sn, W, etc. have been substituted.

[0193] The transition metal of the lithium-containing transition metal borate compound is preferably V, Ti, Cr, Mn, Fe, Co, Ni, Cu, etc. are preferred. Specific examples of the boric acid compound include, for example, L Iron borates such as iFeBO3, cobalt borates such as LiCoBO3, and lithium Some of the transition metal atoms that make up the main part of the transition metal borate compound are Al, Ti, V, Cr, Mn, Fe, Co, Li, Ni, Cu, Zn, Mg, Ga, Zr, Si, Nb, Mo, Sn, W and the like, which have been substituted with other metals.

[0194] (2) Manufacturing method of positive electrode active material The method for producing the positive electrode active material is not particularly limited as long as it does not deviate from the gist of the present invention. There are several methods, and a method generally used for producing inorganic compounds is used. In particular, various methods can be considered for producing spherical or oval-spherical active materials. For example, As an example, a transition metal source material such as a transition metal nitrate or sulfate and, if necessary, other elements The raw material is dissolved or crushed and dispersed in a solvent such as water, and the pH is adjusted while stirring to form a spherical shape. The precursors are prepared and collected, dried as necessary, and then added to LiOH, Li2CO3, and Li One method is to add a Li source such as NO3 and bake at high temperature to obtain the active material.

[0195] As another example of the method, a transition metal such as a transition metal nitrate, sulfate, hydroxide, or oxide can be used. The raw material and, if necessary, raw materials of other elements are dissolved or pulverized and dispersed in a solvent such as water, This is dried and molded using a spray dryer or similar to form a spherical or elliptical precursor, which is then molded into L A method of adding a Li source such as iOH, Li2CO3, or LiNO3 and baking at high temperature to obtain an active material. Examples include:

[0196] As another example of the method, a transition metal source such as a transition metal nitrate, sulfate, hydroxide, or oxide may be used. The material is a Li source such as LiOH, Li2CO3, or LiNO3, and other elements as necessary. The raw material is dissolved or crushed and dispersed in a solvent such as water, and then dried using a spray dryer or the like. One method is to mold the precursor into a spherical or oval shape, and then sinter it at a high temperature to obtain the active material. Can be obtained.

[0197] <3-1-4-2. Positive electrode structure and manufacturing method> The configuration of the positive electrode used in the present invention and the method for producing the same will be described below. (Method of making positive electrode) The positive electrode is formed by forming a positive electrode active material layer containing positive electrode active material particles and a binder on a current collector. The positive electrode using the positive electrode active material can be produced by any known method. For example, a positive electrode active material and a binder, and optionally a conductive material and a thickener, etc., can be mixed. These materials are mixed in a dry state and pressed into a sheet to be attached to the positive electrode current collector, or The material is dissolved or dispersed in a medium to form a slurry, which is then applied to the positive electrode current collector and dried. Thus, a positive electrode active material layer can be formed on the current collector to obtain a positive electrode.

[0198] The content of the positive electrode active material in the positive electrode active material layer is preferably 60 mass % or more, and more preferably 70 mass % or more. % or more, more preferably 80% by mass or more, and further preferably 99.9% by mass or more. % or less, and more preferably 99% or less by mass. By doing so, it is possible to secure a sufficient electric capacity. Furthermore, the strength of the positive electrode is also sufficient. The positive electrode active material powder in the present invention may be used alone or in combination with different compositions or different powders. Two or more active materials may be used in any combination and ratio. When used in combination, the composite oxide containing lithium and manganese is used as a powder component. As described above, cobalt and nickel are expensive metals with limited resources. Therefore, in large batteries that require high capacity, such as those for automobiles, the amount of active material used becomes large. Therefore, it is not desirable from the viewpoint of cost, so manganese is used as the main component as a cheaper transition metal. This is because it is desirable to use it for

[0199] (Conductive material) As the conductive material, any known conductive material can be used. Specific examples include copper, nickel, Metallic materials such as nickel; graphite such as natural graphite and artificial graphite; acetylene black carbon black such as carbide; amorphous carbon such as needle coke; and other carbonaceous materials. These may be used alone or in any combination and ratio of two or more. may be used in combination.

[0200] The content of the conductive material in the positive electrode active material layer is preferably 0.01 mass % or more, and more preferably 0.1 mass % or more. % by mass or more is more preferable, 1% by mass or more is even more preferable, and preferably 50% by mass or more. The content is preferably 30% by mass or less, more preferably 15% by mass or less. Within the above range, sufficient conductivity can be ensured, and a decrease in battery capacity can be easily prevented.

[0201] (binder) The binder used in the production of the positive electrode active material layer is compatible with the non-aqueous electrolyte and the solvent used in the production of the electrode. There are no particular limitations on the material as long as it is stable against the solvent. When preparing a positive electrode by the coating method, the binder is soluble in the liquid medium used in the electrode production. There is no particular limitation as long as the material is dissolved or dispersed, but a specific example is polyethylene. , polypropylene, polyethylene terephthalate, polymethyl methacrylate, aromatic poly Resin-based polymers such as amides, cellulose, and nitrocellulose;

[0202] SBR (styrene-butadiene rubber), NBR (acrylonitrile-butadiene rubber) Rubber-like materials such as fluororubber, isoprene rubber, butadiene rubber, and ethylene-propylene rubber polymer; Styrene-butadiene-styrene block copolymer or its hydrogenated derivative, EPDM (ethylenediaminetetraacetate) Styrene-ethylene-butadiene-ethylene terpolymer copolymers, styrene-isoprene-styrene block copolymers or their hydrogenated products, etc. thermoplastic elastomeric polymer;

[0203] Syndiotactic-1,2-polybutadiene, polyvinyl acetate, ethylene vinyl acetate Soft resinous polymers such as propylene copolymers and propylene-α-olefin copolymers; Polyvinylidene fluoride (PVdF), polytetrafluoroethylene, fluorinated polyfluoride Fluoropolymers such as polyvinylidene chloride and polytetrafluoroethylene-ethylene copolymers; Polymer composition having ionic conductivity for alkali metal ions (especially lithium ions) These substances may be used alone or in any combination of two or more. Any combination and ratio may be used.

[0204] The content of the binder in the positive electrode active material layer is preferably 0.1% by mass or more, and more preferably 1% by mass or more. % or more, more preferably 3% by mass or more, and preferably 80% by mass or less. It is more preferably 60% by mass or less, further preferably 40% by mass or less, and more preferably 10% by mass or less. When the ratio of the binder is within the above range, the positive electrode active material can be sufficiently held. This ensures the mechanical strength of the positive electrode, resulting in good battery performance such as cycle characteristics. This also helps to avoid a decrease in battery capacity and conductivity.

[0205] (liquid medium) The liquid medium used to prepare the slurry for forming the positive electrode active material layer is , a conductive material, a binder, and a thickener used as required. As long as the solvent is possible, there is no particular restriction on the type, and either an aqueous solvent or an organic solvent can be used. This is also fine.

[0206] Examples of the aqueous medium include water and a mixture of alcohol and water. Examples of the organic medium include aliphatic hydrocarbons such as hexane; Aromatic hydrocarbons such as benzene, toluene, xylene, and methylnaphthalene; Heterocyclic compounds such as quinoline and pyridine; Ketones such as acetone, methyl ethyl ketone, and cyclohexanone; Esters such as methyl acetate and methyl acrylate; Amines such as diethylenetriamine and N,N-dimethylaminopropylamine; Ethers such as diethyl ether and tetrahydrofuran (THF); N-methylpyrrolidone (NMP), dimethylformamide, dimethylacetamide, etc. Amides; Aprotic polar solvents such as hexamethylphosphatamide and dimethylsulfoxide These may be used alone or in combination of two or more. They may be used in any combination and ratio.

[0207] (Thickener) When an aqueous medium is used as the liquid medium for forming the slurry, a thickener and styrene It is preferable to form a slurry using a latex such as butadiene rubber (SBR). The agent is usually used to adjust the viscosity of the slurry. There are no limitations on the thickener as long as it does not significantly limit the effects of the present invention. carboxymethylcellulose, methylcellulose, hydroxymethylcellulose, ethylcellulose cellulose, polyvinyl alcohol, oxidized starch, phosphated starch, casein and the like These may be used alone or in any combination of two or more. They may be used in combination in any ratio.

[0208] When a thickener is used, the ratio of the thickener to the total mass of the positive electrode active material and the thickener is , preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and more preferably 0.6% by mass or more. More preferably, the content is 5% by mass or less, and more preferably, 3% by mass or less. It is preferably 2 mass % or less, and more preferably 2 mass % or less. When it is within the above range, the coating property of the slurry becomes good. Furthermore, the ratio of the active material in the positive electrode active material layer is sufficient, so that the capacity of the secondary battery is increased. This makes it easier to avoid problems such as a decrease in the capacitance of the positive electrode and an increase in resistance between the positive electrode active materials.

[0209] (Consolidation) The positive electrode active material layer obtained by applying the above slurry to the current collector and drying it is In order to increase the packing density, it is preferable to compact the mixture using a hand press, a roller press, or the like. The density of the positive electrode active material layer is 1 g cm -3 More than 1.5g cm is preferable. -3 End is more preferable, and 2 g cm-3 More than 4g cm is particularly preferable. -3 The following is preferred 3.9g cm -3 Less than 3.8g cm is more preferable. -3 The following is particularly preferred . When the density of the positive electrode active material layer is within the above range, the non-aqueous electrolyte is easily introduced into the vicinity of the current collector / active material interface. The permeability of the solution does not decrease, and the charge / discharge characteristics of the secondary battery, especially at high current densities, are excellent. Furthermore, the electrical conductivity between the active materials is less likely to decrease, and the battery resistance is less likely to increase.

[0210] (current collector) The material of the positive electrode current collector is not particularly limited, and any known material can be used. Specific examples include aluminum, stainless steel, nickel plating, titanium, tantalum, etc. Metallic materials: Carbonaceous materials such as carbon cloth and carbon paper. The material is preferred, especially aluminum.

[0211] The shape of the current collector may be metal foil, metal cylinder, metal coil, metal plate, or metal wire. Examples of materials that can be used include metal thin films, expanded metals, punched metals, and foamed metals. In this case, examples of the material include a carbon plate, a carbon thin film, a carbon cylinder, etc. Among these, a metal thin film is preferable. The thin film may be formed in a mesh shape as appropriate. The thickness of the current collector is not limited, but is preferably 1 μm or more, and more preferably 3 μm or more. It is preferably 5 μm or more, more preferably 1 mm or less, and more preferably 100 μm or less. It is more preferable that the thickness of the current collector is 50 μm or less, and further more preferable that the thickness of the current collector is 50 μm or less. The strength required as an electrical conductor can be sufficiently ensured. Furthermore, the handling properties are also good.

[0212] The thickness ratio of the current collector to the positive electrode active material layer is not particularly limited. The ratio of the active material layer thickness on one side to the thickness of the current collector is preferably 150 or less, and more preferably 20 or less. More preferably, it is 10 or less, particularly preferably, it is 0.1 or more, and 0.4 or less. The ratio of the thickness of the current collector to the thickness of the positive electrode active material layer is preferably in the above range, and more preferably in the range of 1 or more. If the temperature is within this range, the collector is less likely to generate heat due to Joule heat during high current density charging and discharging of the secondary battery. Furthermore, it becomes difficult to increase the volume ratio of the current collector to the positive electrode active material, which leads to a decrease in the battery capacity. This can be prevented.

[0213] (electrode area) In order to improve the stability at high output and high temperatures, the area of ​​the positive electrode active material layer is set to be smaller than that of the battery outer case. It is preferable that the thickness of the nonaqueous electrolyte secondary battery is large relative to the outer surface area of ​​the battery. It is preferable that the total electrode area of ​​the positive electrode is 20 times or more the surface area of ​​the device. The outer surface area of ​​the outer case is preferably 40 times or more. In the case of the battery, the length, width, and thickness of the case part filled with the power generating element, excluding the protruding part of the terminal, The total area is calculated from the dimensions. In the case of a cylindrical shape with a bottom, this does not include the protruding part of the terminal. This is the geometric surface area of ​​the case filled with the power generating element, approximating it as a cylinder. The sum of the areas is the geometric surface area of ​​the positive electrode mixture layer facing the mixture layer containing the negative electrode active material, and is In the case of a structure in which a positive electrode composite layer is formed on both sides via a body foil, each side is calculated separately. The sum of areas.

[0214] (discharge capacity) When the non-aqueous electrolyte of the present invention is used, the non-aqueous electrolyte secondary battery is housed in a single battery exterior. The electric capacity of the battery element (the electric capacity when the battery is discharged from a fully charged state to a discharged state) When the capacity of the battery is 1 ampere hour (Ah) or more, the effect of improving low-temperature discharge characteristics is large. Therefore, the positive plate is preferably designed to have a discharge capacity of 3 Ah (amps) when fully charged. 1Ah), more preferably 4Ah or more, and preferably 20Ah or less; More preferably, it is designed to be 10 Ah or less.

[0215] Within the above range, the voltage drop due to electrode reaction resistance becomes large when a large current is drawn. This prevents deterioration of power efficiency. The temperature distribution caused by the battery is not too large, and the durability of the battery after repeated charging and discharging is poor. This avoids the phenomenon that the heat dissipation efficiency deteriorates when sudden heat is generated due to an abnormality such as a short circuit. can.

[0216] (Positive plate thickness) The thickness of the positive electrode plate is not particularly limited, but from the viewpoint of high capacity, high output, and high rate characteristics, The thickness of the positive electrode active material layer, excluding the thickness of the current collector, is 10 μm or more on one side of the current collector. is preferable, 20 μm or more is more preferable, and 200 μm or less is preferable, and 150 μm or less is more preferable. m or less is more preferable.

[0217] <3-1-5. Separator> In the non-aqueous electrolyte secondary battery of the present invention, a conductive layer is provided between the positive electrode and the negative electrode to prevent short circuit. In this case, the non-aqueous electrolyte of the present invention is usually It is used by impregnating a parater. There are no particular limitations on the material and shape of the separator, as long as they do not significantly impair the effects of the present invention. As long as the electrolyte is suitable for the non-aqueous electrolyte solution of the present invention, any known electrolyte may be used. Made of stable materials such as resin, glass fiber, and inorganic substances, it is a porous material with excellent liquid retention. It is preferable to use a material in the form of a porous sheet or nonwoven fabric.

[0218] Resin and glass fiber separator materials include, for example, polyethylene and polypropylene. Polyolefins, aramid resins, polytetrafluoroethylene, polyether sulfonates, etc. Among them, glass filters and polypropylene filters are preferable. Preferably, the material is a polyethylene, more preferably a polyolefin. or two or more of them may be used in any combination and in any ratio.

[0219] The thickness of the separator is not limited, but is preferably 1 μm or more, and more preferably 5 μm or more. More preferably, the thickness is 10 μm or more, and even more preferably, the thickness is 50 μm or less. The thickness of the separator is preferably 30 μm or less, and more preferably 30 μm or less. Within this range, the insulating properties and mechanical strength are excellent. Furthermore, the battery performance such as rate characteristics is also improved. This prevents a decrease in the energy density of the non-aqueous electrolyte secondary battery as a whole. It is possible to do so.

[0220] Furthermore, when a porous material such as a porous sheet or nonwoven fabric is used as the separator, The porosity of the core may be any value, but is preferably 20% or more, and more preferably 35% or more. More preferably, the ratio is 45% or more, and more preferably, 90% or less, and even more preferably, 85% or less. When the porosity is within the above range, the membrane resistance becomes large. This prevents the rate characteristics of the secondary battery from deteriorating. The amount of heat generated becomes appropriate, and the deterioration of the insulating properties can be suppressed.

[0221] The average pore size of the separator can also be any size, but is preferably 0.5 μm or less, and 0. The average pore size is preferably 2 μm or less, and more preferably 0.05 μm or more. Within this range, short circuits are unlikely to occur. Furthermore, the membrane resistance is not too high, and the secondary battery This can prevent a decrease in the rate characteristics. On the other hand, inorganic materials include, for example, oxides such as alumina and silicon dioxide, aluminum nitride, etc. Nitrides such as lumi and silicon nitride, and sulfates such as barium sulfate and calcium sulfate are used. The powder may be in the form of particles or fibers.

[0222] The separator is typically in the form of a thin film such as a nonwoven fabric, woven fabric, or microporous film. The thin-film separator has a pore size of 0.01 to 1 μm and a thickness of 5 to 50 μm. In addition to the independent thin film shape, a resin binder is used. A cell having a composite porous layer containing the inorganic particles formed on the surface layer of a positive electrode and / or a negative electrode. For example, aluminium with a 90% particle size of less than 1 μm can be used on both sides of the positive electrode. Using mina particles and fluororesin as a binder to form a porous layer Examples include:

[0223] <3-1-6.Battery design> (electrode group) The electrode group has a laminated structure including the positive electrode plate and the negative electrode plate with the separator interposed therebetween, The positive and negative electrodes are wound in a spiral shape with the separator interposed therebetween. The ratio of the volume of the electrode group to the internal volume of the battery (hereinafter referred to as the electrode group occupancy rate) The ratio of the number of the particles is preferably 40% or more, more preferably 50% or more, and more preferably 90% or more. When the electrode group occupancy rate is within the above range, the electrode In addition, since a suitable amount of space is provided, the battery can withstand high temperatures. This causes the components to expand and the vapor pressure of the non-aqueous electrolyte to increase. The internal pressure increases, and various characteristics of the secondary battery, such as the charge / discharge cycle performance and high-temperature storage characteristics, are degraded. This can prevent the pressure from dropping or even the gas release valve from venting the internal pressure to the outside from operating. can.

[0224] (Current collection structure) The current collecting structure is not particularly limited, but the improvement of discharge characteristics by the non-aqueous electrolyte of the present invention is To achieve this more effectively, it is necessary to use a structure that reduces the resistance of the wiring and joints. When the internal resistance is reduced in this way, the effect of using the nonaqueous electrolyte of the present invention is It is particularly well demonstrated.

[0225] In the case of electrodes with the aforementioned laminated structure, the metal cores of the electrode layers are bundled and welded to the terminals. When the area of ​​one electrode becomes large, the internal resistance becomes large. Therefore, it is preferable to provide multiple terminals in the electrode to reduce the resistance. In the case where the electrode group has the aforementioned wound structure, multiple lead structures are provided on the positive and negative electrodes, and the terminals are By bundling them into a bundle, the internal resistance can be reduced.

[0226] (Protection element) As a protective element, it is a PTC (Positive Temperature Coefficient) that increases resistance when abnormal heat is generated or excessive current flows. ive Temperature Coefficient) Thermistor, Temperature Hue When abnormal heat is generated, the internal pressure or temperature of the battery increases rapidly, cutting off the current flowing through the circuit. The above protective element is designed to operate under conditions that would not be activated under normal use of high current. It is preferable to select a battery that does not generate abnormal heat or go into thermal runaway even without a protective element. It is preferable to design it in.

[0227] (Exterior body) The non-aqueous electrolyte secondary battery of the present invention generally comprises the above-mentioned non-aqueous electrolyte, a negative electrode, a positive electrode, a separator, The device is configured by housing the components such as the sensor and the sensor element in an exterior body (exterior case). There is no limitation on the exterior body, and the present invention Any known material can be used as long as it does not significantly impair the effect of the above. There are no particular limitations on the material of the exterior case, so long as it is stable against the non-aqueous electrolyte used. Specifically, nickel-plated steel sheets, stainless steel, aluminum or aluminum alloy sheets are not included. Aluminum alloys, magnesium alloys, nickel, titanium and other metals, or resin and aluminum foil From the viewpoint of weight reduction, aluminum laminated film is used. A metal such as aluminum or an aluminum alloy, or a laminate film is preferably used.

[0228] For exterior cases using the above metals, the metals are welded by laser welding, resistance welding, or ultrasonic welding. The above metals are welded together to form a sealed structure, or the above metals are sealed together through a resin gasket. The laminate film is used to form a crimped structure. In the case of the sealed structure, the resin layers are thermally bonded to each other to form a sealed structure. In order to improve the film strength, a resin different from that used in the laminate film is used between the resin layers. In particular, when the resin layer is heat-sealed via the current collecting terminal to form a sealed structure, In the case of bonding between metal and resin, the resin to be bonded is a resin having a polar group or a resin having a polar group. A modified resin into which is introduced is preferably used. The shape of the exterior case is also arbitrary, for example, cylindrical, rectangular, laminated, coin-shaped, etc. It may be either small, medium, large, etc.

[0229] <3-2.Non-aqueous electrolyte primary battery> The non-aqueous electrolyte primary battery according to one embodiment of the present invention has, for example, a positive electrode that occludes metal ions. The material used for the positive electrode is a material capable of releasing metal ions, and the material used for the negative electrode is a material capable of releasing metal ions. The negative electrode material is preferably a transition metal oxide such as zinc or lithium. As the non-aqueous electrolyte, the non-aqueous electrolyte of the present invention described above is used. .

[0230] <3-3. Metal ion capacitor> The metal ion capacitor according to one embodiment of the present invention has, for example, a positive electrode that forms an electric double layer. The positive electrode material is a material that can absorb and release metal ions, and the negative electrode material is a material that can absorb and release metal ions. The negative electrode material is preferably an activated carbon. The negative electrode material is preferably a carbonaceous material. The non-aqueous electrolyte solution of the present invention is used.

[0231] <3-4. Electric double layer capacitor> In the electric double layer capacitor according to one embodiment of the present invention, for example, an electric double layer is formed on the electrodes. The electrode material is preferably activated carbon. The non-aqueous electrolyte is The non-aqueous electrolyte of the present invention is used. EXAMPLES

[0232] The present invention will be described in more detail below with reference to examples and reference examples. The present invention is not limited to these examples unless it goes beyond the scope of the present invention. Example 1 [Preparation of negative electrode] 98 parts by mass of carbonaceous material, carboxymethyl cellulose as a thickener and binder Aqueous dispersion of sodium (concentration of sodium carboxymethylcellulose) 1 part by mass of styrene-butadiene rubber (styrene-butadiene rubber) 1 part by mass of diene rubber (concentration: 50% by mass) was added and mixed in a disperser to form a slurry. The obtained slurry was applied to a copper foil having a thickness of 10 μm, dried, and rolled with a press. The size of the active material layer was 30 mm in width, 40 mm in length, and 5 mm in width, 9 mm in length. The negative electrode was prepared by cutting the sheet into a shape having a coated portion.

[0233] [Preparation of positive electrode] LiNi as the positive electrode active material 0.5 Mn 0.2 Co 0.3 O2 94% by mass and conductive material 3% by weight of acetylene black and polyvinylidene fluoride (PVdF) as a binder. The mixture was mixed in N-methylpyrrolidone solvent to form a slurry. The lysate was applied to one side of a 15 μm thick aluminum foil that had previously been coated with a conductive additive, dried, and then The active material layer was roll-pressed using a press machine to obtain a width of 30 mm and a length of 40 mm. The positive electrode was then cut into a shape having an uncoated portion measuring 5 mm in width and 9 mm in length.

[0234] [Preparation of non-aqueous electrolyte] Ethylene carbonate (EC) and dimethyl carbonate (DM C) and ethyl methyl carbonate (EMC) (volume ratio 20:40:40) were dried. 98 parts by mass of dried LiPF6 dissolved in a 1.2 mol / L solution. 1 part by mass of vinylene carbonate and 1 part by mass of lithium difluorophosphate were mixed to obtain a base. This electrolyte was prepared by mixing 99.5 parts by mass of this basic electrolyte solution and 2, 0.5 parts by mass of 2,2-trimethoxy-4,5-dimethyl-1,3,2-dioxaphosphorane The nonaqueous electrolyte solution of Example 1 was prepared by mixing.

[0235] [ka]

[0236] [Manufacture of non-aqueous electrolyte secondary batteries] The positive electrode, negative electrode, and polyethylene separator are arranged in the following order: negative electrode, separator, positive electrode. The battery element was laminated on both sides of the aluminum (thickness 40 μm). The positive and negative terminals of the battery element are placed in a bag made of a laminate film covered with a resin layer. After inserting the bag so that it protrudes from the outside, the electrolyte is injected into the bag, and the bag is vacuum sealed. A sheet-shaped nonaqueous electrolyte secondary battery of Example 1 was produced, which was fully charged at 1000 V.

[0237] [Evaluation of initial discharge capacity] The non-aqueous electrolyte secondary battery was sandwiched between glass plates to improve adhesion between the electrodes. At 5℃, charge to 4.3V at a constant current equivalent to 0.2C, then charge to 4.3V at a constant current of 0.2C. The battery was discharged to 2.8 V at 0 V for two cycles to stabilize the battery. After charging to 4.3V at a constant current of .2C, charge to a constant voltage of 4.3V until the current value becomes 0.05C. The battery was charged at 0.2C and discharged to 2.8V at a constant current of 0.2C. After charging to 4.3V at a constant current of .2C, charge to a constant voltage of 4.3V until the current value becomes 0.05C. The battery was charged at 100 V and discharged at a constant current of 0.2 C to 2.8 V to determine the initial discharge capacity.

[0238] [Evaluation of initial output] After the initial discharge capacity evaluation, the battery was discharged at a constant current of 0.2 C at 25°C. The battery was charged to half its capacity at -20°C with a current of 0.5C, 1.0C, and 1. Discharge at 0.5C, 2.0C, and 2.5C, and measure the voltage after 10 seconds. Calculate the current value at 2.8V from the line, and output 2.8 x (current value at 2.8V) as the initial output. (W).

[0239] [Evaluation of swelling during high temperature storage] After the evaluation of the initial discharge capacity, the battery was immersed in an ethanol bath and the volume was measured. The volume before high-temperature storage was taken as the volume before high-temperature storage. At 25°C, the voltage was increased to 4.3 V at a constant current equivalent to 0.2 C. After charging, the battery was stored at 60°C for 14 days, cooled to room temperature, and then placed in an ethanol bath. The volume was measured after high-temperature storage, and the volume after high-temperature storage was subtracted from the volume before high-temperature storage. The value obtained by subtracting the volume of the sample from the total volume was defined as the swelling during high-temperature storage.

[0240] [Evaluation of storage capacity maintenance rate] The battery whose volume was measured after high-temperature storage was then charged to 2.8V at a constant current of 0.2C at 25℃. Discharge the battery, charge it at a constant current of 0.2C up to 4.3V, and then charge it at a constant voltage until the current becomes 0.05C. A test was conducted in which the battery was charged to 5 V and discharged to 2.8 V at a constant current of 0.2 C. The discharge capacity after storage at high temperature was calculated. Furthermore, the storage capacity retention rate (%) was calculated using the following formula. Storage capacity retention rate (%) = (Discharge capacity after high temperature storage) ÷ (Initial discharge capacity) × 100

[0241] [Evaluation of output after saving and maintenance rate of saved output] The battery that was evaluated for its capacity retention rate after high-temperature storage was first charged at 25°C with a constant current of 0.2C. The batteries were charged to half the initial discharge capacity at -20°C and 0.5C, respectively. The battery was discharged at 0.0C, 1.5C, 2.0C, and 2.5C, and the voltage was measured after 10 seconds. From the current-voltage line, find the current value at 2.8 V, and calculate it as 2.8 x (current value at 2.8 V) was defined as the output after storage (W). Furthermore, the storage output maintenance rate (%) was calculated using the following formula. Saved output maintenance rate (%) = (output after saving) ÷ (initial output) x 100

[0242] Example 2 The same procedure as in Example 1 was repeated except that compound (1-B) was used instead of compound (1-A). A sheet-shaped nonaqueous electrolyte secondary battery of Example 2 was then produced and evaluated.

[0243] [ka]

[0244] Comparative Example 1 The same procedure as in Example 1 was repeated except that the above-mentioned basic electrolyte solution was used as is. A sheet-shaped non-aqueous electrolyte secondary battery was produced and evaluated.

[0245] Comparative Example 2 The same procedure as in Example 1 was repeated except that tributyl phosphite was used instead of compound (1-A). A sheet-shaped nonaqueous electrolyte secondary battery of Comparative Example 1 was fabricated and evaluated. The evaluation results of Examples 1 and 2, and Comparative Examples 1 and 2 are shown in Table 1. The storage capacity maintenance rate and storage output maintenance rate are both calculated based on the value of Comparative Example 1 taken as 100%. Relative values ​​are shown.

[0246] [Table 1]

[0247] As is clear from Table 1, Examples 1 and 2 were superior to Comparative Examples 1 and 2 in all evaluation items. It is clear that it is superior. [Industrial Applicability]

[0248] According to the non-aqueous electrolyte of the present invention, the non-aqueous electrolyte secondary battery can be effectively used during cycle operation or high-temperature storage. The cycle capacity maintenance rate during durability, input / output characteristics after cycling (input / output maintenance rate), Therefore, the nonaqueous electrolyte of the present invention and the nonaqueous electrolyte using the same are useful. Energy devices such as aqueous electrolyte secondary batteries can be used for a variety of known purposes. Specific examples include notebook computers, pen-input computers, and mobile computers. e-book players, mobile phones, mobile fax machines, mobile copiers, mobile printers, Headphone stereos, video cameras, LCD TVs, handheld cleaners, portable devices CDs, mini discs, transceivers, electronic organizers, calculators, memory cards, portable tapes Recorders, radios, backup power supplies, motors, automobiles, motorcycles, mopeds, Bicycles, lighting equipment, toys, game equipment, watches, power tools, strobes, cameras, household batteries Backup power source, business backup power source, load leveling power source, natural energy storage power source , lithium ion capacitors, etc.

Claims

1. P(OR) ５ A non-aqueous electrolyte for energy devices containing a compound represented by the following structural formula: (In the structural formula, R are each independently a hydrocarbon group having 1 to 8 carbon atoms, which may be linear or branched, and may be linked together to form a ring structure.)

2. Said P(OR) ５ 2. The nonaqueous electrolyte solution for an energy device according to claim 1, wherein the content of the compound represented by the structural formula:

3. 3. The nonaqueous electrolyte solution for an energy device according to claim 1 or 2, comprising at least one compound selected from the group consisting of inorganic lithium halide salts, lithium fluorophosphate salts, lithium tungstate salts, lithium carboxylate salts, lithium sulfonate salts, lithium sulfate salts, lithium imide salts, lithium methide salts, lithium oxalate salts, and fluorine-containing organic lithium salts.

4. The non-aqueous electrolyte is LiPF ６ Including PF ６ and P(OR) ５ Molar ratio of [PF ６ ] / [P (OR) ５ 4. The method according to claim 1, wherein the ratio of the number of the sieving agents to the number of the sieving agents is 2.0 or more and 2500 or less. Non-aqueous electrolyte for energy devices.

5. The nonaqueous electrolyte solution for an energy device according to any one of claims 1 to 4, wherein the nonaqueous electrolyte solution contains at least one compound selected from the group consisting of saturated cyclic carbonates, chain carbonates, chain carboxylate esters, cyclic carboxylate esters, ether-based compounds, and sulfone-based compounds.

6. The non-aqueous electrolyte solution is a cyclic carbonate having a carbon-carbon unsaturated bond, a cyclic carbonate having a fluorine atom, a fluorinated unsaturated cyclic carbonate, SO ２ The present invention is based on the group consisting of a cyclic compound having a cyclic group, a compound having a cyano group, an isocyanate compound, and a carboxylic acid anhydride. The nonaqueous electrolyte solution for energy devices according to any one of claims 1 to 5, comprising at least one compound selected from the group consisting of:

7. An energy device comprising a positive electrode and a negative electrode capable of absorbing and releasing metal ions, and the nonaqueous electrolyte solution for an energy device according to any one of claims 1 to 6.

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