JP2008210769A - Nonaqueous electrolyte battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a battery capable of suppressing bulging of a laminated battery in high temperature storage. <P>SOLUTION: A nonaqueous electrolyte battery includes: an outer packaging formed with a laminated film; an electrode body formed by laminating, through a separator, a positive electrode and a negative electrode made of a carbon material, both housed in the outer packaging; and an electrolyte, wherein the electrolyte contains at least one of silane derivatives having a hydrogen-silicon bond. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a non-aqueous electrolyte secondary battery using an electrolyte solution containing a silane derivative having a hydrogen-silicon bond.

  In recent years, many portable electronic devices such as a camera-integrated VTR, a digital still camera, a mobile phone, a personal digital assistant, and a notebook computer have appeared, and their size and weight have been reduced. As portable power sources for these electronic devices, research and development for improving the energy density of batteries, particularly secondary batteries, are being actively promoted.

  Among secondary batteries, a lithium ion secondary battery using a non-aqueous solvent such as carbon as a negative electrode active material, a lithium-transition metal composite oxide as a positive electrode active material, and a carbonate ester mixture as an electrolyte is a conventional aqueous electrolyte. Since a large energy density can be obtained as compared with lead batteries and nickel cadmium batteries which are secondary batteries, they are widely put into practical use (Patent Documents 1 to 3). In particular, a laminated battery using an aluminum laminate film for the exterior has a high energy density because it is lightweight. In the laminate type battery, since the deformation of the laminate type battery can be suppressed by swelling the electrolyte in the polymer, the laminate polymer battery is also widely used.

JP-A-8-78053 JP 2006-137741 A JP 2001-319685 A

  However, the laminate type battery has a problem that it is easy to swell in a high temperature environment due to its soft exterior. This invention is made | formed in view of this problem, and it aims at providing the battery which can suppress the expansion | swelling at the time of the high temperature preservation | save of a laminate type battery.

  The non-aqueous electrolyte battery according to the present invention includes an outer container formed of a laminate film, a positive electrode housed in the outer container and a negative electrode made of a carbon material, and an electrode body and an electrolytic solution formed by laminating a separator. The non-aqueous electrolyte battery comprises: at least one silane derivative having a hydrogen-silicon bond.

  According to the battery of the present invention, a good film can be formed on the positive electrode by using a negative electrode made of a carbon material by containing a silane derivative having a hydrogen-silicon bond in the electrolytic solution, and the high temperature of the laminated battery. While suppressing the expansion | swelling at the time of a preservation | save, the outstanding charging / discharging efficiency can be hold | maintained.

  In particular, the content of the silane derivative in the electrolytic solution is 0.1% by mass or more and 0.7% by mass or less, or vinylene carbonate as a carbonic acid ester having a carbon-carbon multiple bond and a polymer compound that is swollen by the electrolytic solution. If at least one of the vinylidene chlorides is contained in the electrolytic solution, a higher effect can be obtained.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings, but the present invention is not limited to the following mode.

  FIG. 1 schematically shows a configuration of a laminated battery according to an embodiment of the present invention. This secondary battery is a so-called laminate film type, and has a wound electrode body 20 to which a positive electrode lead 21 and a negative electrode lead 22 are attached accommodated in a film-shaped exterior member 30.

  The positive electrode lead 21 and the negative electrode lead 22 are led out from the inside of the exterior member 30 to the outside, for example, in the same direction. The positive electrode lead 21 and the negative electrode lead 22 are each made of a metal material such as aluminum, copper, nickel, and stainless steel, and each have a thin plate shape or a mesh shape.

  The exterior member 30 is made of, for example, a rectangular aluminum laminated film in which a nylon film, an aluminum foil, and a polyethylene film are bonded together in this order. The exterior member 30 is disposed, for example, so that the polyethylene film side and the wound electrode body 20 face each other, and the outer edge portions are in close contact with each other by fusion or an adhesive. An adhesion film 31 is inserted between the exterior member 30 and the positive electrode lead 21 and the negative electrode lead 22 to prevent intrusion of outside air. The adhesion film 31 is made of a material having adhesion to the positive electrode lead 21 and the negative electrode lead 22, for example, a polyolefin resin such as polyethylene, polypropylene, modified polyethylene, and modified polypropylene.

  The exterior member 30 may be made of a laminated film having another structure, a polymer film such as polypropylene, and a metal film instead of the above-described aluminum laminated film.

  FIG. 2 shows a cross-sectional structure taken along line II of the spirally wound electrode body 20 shown in FIG. The wound electrode body 20 is obtained by laminating a positive electrode 23 and a negative electrode 24 via a separator 25 and an electrolyte layer 26 and winding them, and the outermost periphery is protected by a protective tape 27.

(Positive electrode)
The positive electrode 23 has a structure in which a positive electrode active material layer 23B is provided on both surfaces of a positive electrode current collector 23A. The negative electrode 24 has a structure in which a negative electrode active material layer 24B is provided on both surfaces of a negative electrode current collector 24A, and the negative electrode active material layer 24B and the positive electrode active material layer 23B are arranged to face each other.

  The positive electrode current collector 23A is made of, for example, a metal material such as aluminum, nickel, and stainless steel. The positive electrode active material layer 24B includes, for example, any one or more of positive electrode materials capable of occluding and releasing lithium as a positive electrode active material, and a conductive agent such as a carbon material and polyvinylidene fluoride as necessary. It may contain a binder.

Examples of the positive electrode material capable of inserting and extracting lithium include lithium cobaltate, lithium nickelate, and solid solutions thereof (Li (NiCo _y Mn _z ) O ₂ )) (x, y, and z have values of 0 <x <1, 0 <y <1, 0 ≦ z <1, x + y + z = 1.), Manganese spinel (LiMn ₂ O ₄ ) and its solid solution (Li (Mn _2−v Ni _v ) O ₄ ) (The value of v is v <2.) Lithium composite oxides and the like, and phosphate compounds having an olivine structure such as lithium iron phosphate (LiFePO ₄ ) are preferable. This is because a high energy density can be obtained. Examples of the positive electrode material capable of inserting and extracting lithium include oxides such as titanium oxide, vanadium oxide and manganese dioxide, disulfides such as iron disulfide, titanium disulfide and molybdenum sulfide, sulfur, And conductive polymers such as polyaniline and polythiophene.

(Negative electrode)
The negative electrode 24 has, for example, a structure in which a negative electrode active material layer 24B is provided on both surfaces of a negative electrode current collector 24A having a pair of opposed surfaces. The negative electrode current collector 24A is made of a metal material such as copper, nickel, and stainless steel, for example.

  The negative electrode active material layer 24B includes any one or more carbon materials capable of inserting and extracting lithium as a negative electrode active material. By including the carbon material, the negative electrode can be stabilized and coating on the positive electrode can be promoted.

  Examples of the carbon material capable of inserting and extracting lithium include non-graphitizable carbon, graphitizable carbon, graphite, pyrolytic carbons, cokes, glassy carbons, and fired organic polymer compounds And carbon materials such as carbon fiber and activated carbon. Among these, examples of coke include pitch coke, needle coke, and petroleum coke. An organic polymer compound fired body refers to a carbonized material obtained by firing a polymer material such as phenol resin or furan resin at an appropriate temperature, and in part, it is made of non-graphitizable carbon or graphitizable carbon. Some are classified. Examples of the polymer material include polyacetylene and polypyrrole. These carbon materials are preferable because the change in crystal structure that occurs during charge and discharge is very small, a high charge and discharge capacity can be obtained, and good cycle characteristics can be obtained. In particular, graphite is preferable because it has a high electrochemical equivalent and can provide a high energy density. Further, non-graphitizable carbon is preferable because excellent characteristics can be obtained. Furthermore, a battery having a low charge / discharge potential, specifically, a battery having a charge / discharge potential close to that of lithium metal is preferable because a high energy density of the battery can be easily realized.

(Separator)
The separator 25 separates the positive electrode 23 and the negative electrode 24 and allows lithium ions to pass through while preventing a short circuit of current due to contact between the two electrodes. The separator 25 is made of, for example, a porous film made of a synthetic resin made of polytetrafluoroethylene, polypropylene, polyethylene, or the like, or a multi-hard film made of ceramic, and a plurality of these porous films are laminated. It may be a structure. For example, the separator 25 is impregnated with an electrolytic solution that is a liquid electrolyte.

(Electrolyte)
The electrolytic solution contains, for example, a solvent and an electrolyte salt dissolved in the solvent. The electrolytic solution contains at least one silane derivative having a hydrogen-silicon bond represented by the following formulas (1) to (6). By including such a silane derivative in the electrolytic solution, it is possible to form a good film with the positive electrode 23, to be more stable against oxidation, and to suppress expansion during high temperature storage. The content of the silane derivative having a hydrogen-silicon bond in the electrolytic solution is preferably in the range of 0.1% by mass to 0.7% by mass. It is because a higher effect is acquired by setting it as this range. One silane derivative having a hydrogen-silicon bond may be used alone, or a plurality of silane derivatives may be used in combination.

In the formula _{(1) ~ (3),} R 1 ~R 7 shows the _{C m H 2m + 1 (1} ≦ m ≦ 18). Further, the formula (4) _{~ (6), R 1 ~R} 15 denotes a _{C m H 2m + 1 (0} ≦ m ≦ 4). R1 to R15 may be the same, or all may be different. Examples of such silane derivatives include phenylsilane represented by the following formula (7), butylsilane represented by the following formula (8), hexylsilane represented by the following formula (9), octadecylsilane represented by the following formula (10), and the following formula: Examples thereof include diphenylsilane represented by (11), diethylsilane represented by the following formula (12), triphenylsilane represented by the following formula (13), and triethylsilane represented by the following formula (14).

(Electrolyte layer)
The electrolyte layer 26 contains the electrolytic solution. The battery of the present invention may be in the form of a gel by containing a polymer compound that swells with the electrolyte and serves as a holding body that holds the electrolyte. It is because high ion conductivity can be obtained by including a polymer compound that swells with the electrolytic solution, excellent charge / discharge efficiency can be obtained, and battery leakage can be prevented. When a polymer compound is added to the electrolytic solution, the content of the polymer compound in the electrolytic solution is preferably in the range of 0.5% by mass to 2.0% by mass. Moreover, when apply | coating and using a high molecular compound on both surfaces of a separator, it is preferable that the mass ratio of a high molecular compound and electrolyte solution exists in the range of 1:10 to 1:50. It is because higher charging / discharging efficiency is obtained by setting it within this range.

  Examples of the polymer compound include ether-based polymer compounds such as polyvinyl formal represented by the following formula (15), polyethylene oxide and a crosslinked product containing polyethylene oxide, and ester-based polymers such as polymethacrylate represented by the following formula (16). Polymers of vinylidene fluoride such as molecular compounds, acrylate polymer compounds, polyvinylidene fluoride represented by the following formula (17), and copolymers of vinylidene fluoride and hexafluoropropylene are exemplified. A high molecular compound may be used individually by 1 type, and multiple types may be mixed and used for it. In particular, from the viewpoint of the effect of preventing swelling during high temperature storage, it is desirable to use a fluorine-based polymer compound such as polyvinylidene fluoride.

In the formulas (15) to (17), s, t, and u are each an integer of 100 to 10,000, and R is C _x H _2x-1 O _y (x is 1 to 8, y is 0 to 4). Indicated.

(solvent)
The solvent contains a high dielectric constant solvent having a relative dielectric constant of 30 or more. This is because the number of lithium ions can be increased. The content of the high dielectric constant solvent in the electrolytic solution is preferably in the range of 15% by mass to 50% by mass. It is because higher charging / discharging efficiency is obtained by setting it within this range.

  Examples of the high dielectric constant solvent include carbonates having carbon-carbon multiple bonds such as vinylene carbonate, ethylene carbonate, propylene carbonate, butylene carbonate and vinyl ethylene carbonate, lactones such as γ-butyrolactone and γ-valerolactone, N -Lactams such as methyl-2-pyrrolidone, cyclic carbamates such as N-methyl-2-oxazolidinone, and sulfone compounds such as tetramethylene sulfone, in particular, carbonates having a carbon-carbon multiple bond are preferred, More preferred is vinylene carbonate. The content of the carbonic acid ester having a carbon-carbon multiple bond in the electrolytic solution is preferably in the range of 0.1% by mass to 2.0% by mass. A high dielectric constant solvent may be used individually by 1 type, and multiple types may be mixed and used for it.

  The high dielectric constant solvent may contain a cyclic carbonate derivative having a halogen atom. Examples of such cyclic carbonate derivatives include fluorinated ethylene carbonates such as 4-fluoro-1,3-dioxolan-2-one, 4-methyl-5-fluoro-1,3-dioxolan-2-one, and the like. And trifluorocarbonic acid such as ethylene difluoride carbonate such as 4,5-difluoro-1,3-dioxolan-2-one, 4-trifluoromethyl-1,3-dioxolan-2-one and ethylene trifluoromethylene carbonate Examples include ethylene and chlorinated ethylene carbonates such as 4-chloro-1,3-dioxolan-2-one. One kind of cyclic carbonate derivative may be used alone, or a plurality of kinds may be mixed and used.

  The high dielectric constant solvent is preferably mixed with a low viscosity solvent having a viscosity of 1 mPa · s or less. This is because high ion conductivity can be obtained. The ratio (mass ratio) of the high dielectric constant solvent and the low viscosity solvent is preferably in the range of 2: 8 to 5: 5. It is because a higher effect can be obtained by setting it within this range.

  Examples of the low viscosity solvent include chain carbonate esters such as dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate, methyl acetate, ethyl acetate, methyl propionate, ethyl propionate, methyl butyrate, methyl isobutyrate, methyl trimethyl acetate, and A chain carboxylic acid ester such as ethyl trimethylacetate, a chain amide such as N, N-dimethylacetamide, a chain carbamic acid ester such as methyl N, N-diethylcarbamate and ethyl N, N-diethylcarbamate, and 1 , 2-dimethoxyethane, tetrahydrofuran, tetrahydropyran and ethers such as 1,3-dioxolane. A low viscosity solvent may be used individually by 1 type, and multiple types may be mixed and used for it.

(Electrolyte salt)
As the electrolyte salt, e.g., lithium hexafluorophosphate (LiPF _6), lithium tetrafluoroborate (LiBF _4), lithium hexafluoroarsenate (LiAsF _6), lithium hexafluoro antimonate (LiSbF ₆₎ , Inorganic lithium salts such as lithium perchlorate (LiClO ₄ ) and lithium tetrachloroaluminate (LiAlCl ₄ ), and lithium trifluoromethanesulfonate (CF ₃ SO ₃ Li), lithium bis (trifluoromethanesulfone) imide [(CF ₃ SO ₂ ) ₂ NLi], lithium bis (pentafluoroethanesulfone) imide [(C ₂ F ₅ SO ₂ ) ₂ NLi] and lithium tris (trifluoromethanesulfone) methide [(CF ₃ SO ₂ ) ₃ CLi] Examples thereof include lithium salts of perfluoroalkanesulfonic acid derivatives. One electrolyte salt may be used alone, or a plurality of electrolyte salts may be mixed and used.

  For example, the secondary battery can be manufactured as follows.

  First, a precursor solution containing an electrolytic solution, a polymer compound, and a mixed solvent is applied to each of the positive electrode 23 and the negative electrode 24, and the mixed solvent is volatilized to form the electrolyte layer 26. Next, the positive electrode lead 21 is attached to the positive electrode current collector 23A, and the negative electrode lead 22 is attached to the negative electrode current collector 24A. Subsequently, the positive electrode 23 and the negative electrode 24 on which the electrolyte layer 26 is formed are laminated through a separator 25 to form a laminated body, and then the laminated body is wound in the longitudinal direction, and the protective tape 27 is attached to the outermost peripheral portion. The wound electrode body 20 is formed by bonding. After that, for example, the wound electrode body 20 is sandwiched between the exterior members 30, and the outer edges of the exterior members 30 are brought into close contact by thermal fusion or the like and sealed. At that time, an adhesion film 31 is inserted between the positive electrode lead 21 and the negative electrode lead 22 and the exterior member 30. Thereby, the secondary battery shown in FIGS. 1 and 2 is completed.

  Further, this secondary battery may be manufactured as follows. First, the positive electrode 23 and the negative electrode 24 are prepared as described above, and after the positive electrode lead 21 and the negative electrode lead 22 are attached to the positive electrode 23 and the negative electrode 24, the positive electrode 23 and the negative electrode 24 are stacked and wound via the separator 25. Rotate and adhere the protective tape 27 to the outermost periphery to form a wound body that is a precursor of the wound electrode body 20. Next, the wound body is sandwiched between the exterior members 30, and the outer peripheral edge portion excluding one side is heat-sealed to form a bag shape, and is stored inside the exterior member 30. Subsequently, an electrolyte composition including an electrolytic solution, a monomer that is a raw material of the polymer compound, and other materials such as a polymerization initiator and a polymerization inhibitor as necessary is prepared, and the interior of the exterior member 30 is prepared. Then, the opening of the exterior member 30 is heat-sealed and sealed. After that, if necessary, heat is applied to polymerize the monomer to form a polymer compound, thereby forming the gel electrolyte layer 26 and assembling the secondary battery shown in FIGS.

  In the secondary battery, when charged, for example, lithium ions are extracted from the positive electrode 23 and inserted in the negative electrode 24 through the electrolytic solution. On the other hand, when discharging is performed, for example, lithium ions are extracted from the negative electrode 24 and inserted into the positive electrode 24 through the electrolytic solution.

  Although the present invention has been described with reference to the embodiment, the present invention is not limited to the embodiment, and various modifications can be made. For example, in the above embodiment, the case where an electrolytic solution is used as the electrolyte is described, and further, the case where a gel electrolyte in which the electrolytic solution is held in a polymer compound is also described, but other electrolytes are used. May be. Other electrolytes include, for example, a mixture of an ion conductive inorganic compound such as ion conductive ceramics, ion conductive glass and ionic crystal and an electrolytic solution, or a mixture of another inorganic compound and an electrolytic solution. Or a mixture of these inorganic compounds and a gel electrolyte.

  In the above embodiment, a battery using lithium as an electrode reactant has been described. However, other alkali metals such as sodium (Na) and potassium (K), alkaline earth metals such as magnesium and calcium (Ca), In addition, the present invention can be applied to the case of using other light metals such as aluminum.

  Furthermore, in the above embodiment, the capacity of the negative electrode is expressed by a capacity component due to insertion and extraction of lithium, or a so-called lithium ion secondary battery, or lithium metal is used for the negative electrode active material, and the capacity of the negative electrode is Although a so-called lithium metal secondary battery represented by a capacity component due to precipitation and dissolution has been described, the present invention makes the charge capacity of the negative electrode material capable of occluding and releasing lithium smaller than the charge capacity of the positive electrode. Thus, the present invention can be similarly applied to a secondary battery in which the capacity of the negative electrode includes a capacity component due to insertion and extraction of lithium and a capacity component due to precipitation and dissolution of lithium, and is expressed by the sum thereof. .

  Furthermore, in the above embodiment, the laminate type secondary battery has been specifically described. However, the present invention is not limited to the secondary battery, and may be similarly applied to other batteries such as a primary battery. Can do.

<Examples 1-1 to 1-12, Comparative Examples 1-1 to 1-3>
(Example 1-1)
First, the positive electrode was produced as follows. 94 parts by weight of lithium-cobalt composite oxide (LiCoO ₂ ) as a positive electrode active material, 3 parts by weight of graphite as a conductive agent, and 3 parts by weight of polyvinylidene fluoride (PVdF) as a binder were mixed uniformly. N-methylpyrrolidone was added to obtain a positive electrode mixture coating solution. Next, the obtained positive electrode mixture coating solution was uniformly applied on both surfaces of an aluminum foil having a thickness of 20 μm and dried to form a positive electrode mixture layer of 40 mg / cm ² per side. This was cut into a shape having a width of 50 mm and a length of 300 mm to produce a positive electrode.

Next, the negative electrode was produced as follows. A negative electrode mixture coating solution was obtained by uniformly mixing 97 parts by weight of graphite as a negative electrode active material and 3 parts by weight of PVdF as a binder and adding N-methylpyrrolidone. Next, the obtained negative electrode mixture coating liquid was uniformly applied on both sides of a 15 μm thick copper foil serving as a negative electrode current collector and dried to form a negative electrode mixture layer of 20 mg / cm ² per side. This was cut into a shape having a width of 50 mm and a length of 300 mm to produce a negative electrode.

  The electrolyte was mixed at a ratio (mass ratio) of ethylene carbonate / propylene carbonate / ethyl methyl carbonate / diethyl carbonate / lithium hexafluorophosphate / phenylsilane = 17/17/26 / 26.5 / 13 / 0.5. Made.

  This positive electrode and negative electrode are laminated and wound through a separator made of a microporous polyethylene film having a thickness of 9 μm, and put into a bag made of an aluminum laminate film. After injecting 2 g of the electrolyte into the bag, the bag is heat-sealed to produce a laminated battery. The capacity of this battery was 700 mAh.

  The battery produced as described above was charged for 3 hours at 700 mA at 23 ° C. and 4.2 V as the upper limit, and then the change in battery thickness when stored at 90 ° C. for 4 hours was examined. Here, the expansion coefficient is a value calculated using the battery thickness before storage as the denominator and the thickness increased during storage as the numerator. Further, after charging for 3 hours at 700 mA and 700 V at 23 ° C. for 3 hours, the discharge capacity retention rate was measured when 300 cycles of 3 mA at 700 mA and the lower limit were repeated for 300 cycles.

(Examples 1-2 to 1-4)
A laminate type battery was prepared in the same manner as in Example 1-1 except that 1.0% by mass of vinylene carbonate was mixed with the electrolytic solution and the phenylsilane concentration was changed to the concentration shown in Table 1, and the physical properties of the battery were evaluated. did.

(Examples 1-5 to 1-11)
Lamination was performed in the same manner as in Example 1-1 except that 1.0% by mass of vinylene carbonate was mixed with the electrolytic solution, and the composition of the silane derivative having a hydrogen-silicon (Si—H) bond was changed to the composition shown in Table 1. Type batteries were prepared and the physical properties of the batteries were evaluated.

(Example 1-12)
A laminate type battery was prepared in the same manner as in Example 1-1 except that 1.0% by mass of vinylene carbonate was mixed with the electrolytic solution and the phenylsilane concentration was changed to the concentration shown in Table 1, and the physical properties of the battery were evaluated. did.

(Comparative Example 1-1)
A laminate type battery was produced in the same manner as in Example 1-1 except that phenylsilane was not mixed with the electrolytic solution and diethyl carbonate was increased by that amount, and the physical properties of the battery were evaluated.

(Comparative Example 1-2)
A laminate type battery was prepared in the same manner as in Example 1-1 except that 1.0% by mass of vinylene carbonate was mixed without mixing phenylsilane with the electrolytic solution, and the physical properties of the battery were evaluated.

(Comparative Example 1-3)
A laminate type as in Example 1-1, except that 1.0% by mass of vinylene carbonate was mixed with the electrolytic solution and tetraethylsilane having no hydrogen-silicon (Si—H) bond was used instead of phenylsilane. A battery was prepared and the physical properties of the battery were evaluated.

  Table 1 shows the results of evaluating the physical properties of the laminate type batteries produced in Examples 1-1 to 1-12 and Comparative Examples 1-1 to 1-3.

  As shown in Table 1, in Example 1-1 using an electrolytic solution in which a silane derivative (phenylsilane) having a hydrogen-silicon (Si-H) bond was mixed, an electrolytic solution not containing phenylsilane was used. Compared to Comparative Example 1-1, the change in battery thickness when stored at 90 ° C. for 4 hours decreased. On the other hand, instead of using a silane derivative having a hydrogen-silicon (Si-H) bond, a comparison was made using an electrolytic solution in which a silane derivative (tetraethylsilane) having no hydrogen-silicon (Si-H) bond was mixed with vinylene carbonate. In Example 1-3, compared with Comparative Example 1-2, the change in battery thickness when stored at 90 ° C. for 4 hours was not reduced. From these results, it was found that the battery expansion during high-temperature storage can be suppressed by mixing a silane derivative having a hydrogen-silicon (Si—H) bond with the electrolytic solution.

Moreover, in Example 1-2 which mixed vinylene carbonate with electrolyte solution in addition to phenylsilane, the high discharge capacity maintenance factor was shown compared with Example 1-1 which does not contain vinylene carbonate in electrolyte solution. Furthermore, an electrolytic solution in which a silane derivative (phenylsilane, butylsilane, hexylsilane, octadecylsilane, diphenylsilane, diethylsilane, triphenylsilane, or triethylsilane) having a hydrogen-silicon (Si-H) bond is mixed with vinylene carbonate. In Examples 1-2 to 1-11 used, the battery thickness when stored at 90 ° C. for 4 hours as compared with Comparative Example 1-2 using an electrolytic solution containing vinylene carbonate and not containing the silane derivative. And the high discharge capacity retention rate was maintained.
From these facts, by mixing vinylene carbonate with the silane derivative having a hydrogen-silicon (Si—H) bond in the electrolyte, it is possible to maintain excellent charge / discharge efficiency while suppressing battery expansion during high-temperature storage. I understood.

  In Example 1-3 in which the concentration of phenylsilane in the electrolytic solution was 0.1% by mass and Example 1-4 in which 0.7% by mass was used, the same as Example 1-2 in which the concentration was 0.5% by mass. In comparison with Comparative Example 1-2 in which the electrolytic solution does not contain phenylsilane and contains vinylene carbonate, the change in battery thickness when stored at 90 ° C. for 4 hours was reduced. On the other hand, in Example 1-12 in which the concentration of phenylsilane in the electrolytic solution was 1.0 mass%, the change in battery thickness when stored at 90 ° C. for 4 hours decreased, but the discharge capacity retention rate after 300 cycles Decreased significantly. From these results, it was found that good results can be obtained when the concentration of the silane derivative having a hydrogen-silicon (Si—H) bond in the electrolytic solution is in the range of 0.1 to 0.7 mass%.

<Examples 2-1 to 2-12, Comparative Examples 2-1 to 2-3>
(Example 2-1)
A laminate type battery was prepared in the same manner as in Example 1-1 except that 1.0% by mass of polyvinyl formal was swollen in the electrolytic solution and diethyl carbonate was reduced by that amount, and the physical properties of the battery were evaluated.

(Examples 2-2 to 2-4)
A laminate type battery was prepared in the same manner as in Example 2-1, except that 1.0% by mass of vinylene carbonate was mixed with the electrolytic solution, and the phenylsilane concentration was changed to the concentration shown in Table 2, and the physical properties of the battery were evaluated. did.

(Examples 2-5 to 2-11)
Lamination was performed in the same manner as in Example 2-1, except that 1.0% by mass of vinylene carbonate was mixed with the electrolytic solution, and the composition of the silane derivative having a hydrogen-silicon (Si—H) bond was changed to the composition shown in Table 2. Type batteries were prepared and the physical properties of the batteries were evaluated.

(Example 2-12)
A laminate type battery was prepared in the same manner as in Example 2-1, except that 1.0% by mass of vinylene carbonate was mixed with the electrolytic solution, and the phenylsilane concentration was changed to the concentration shown in Table 2, and the physical properties of the battery were evaluated. did.

(Comparative Example 2-1)
A laminate type battery was prepared in the same manner as in Example 2-1, except that phenylsilane was not mixed with the electrolytic solution and diethyl carbonate was increased by that amount, and the physical properties of the battery were evaluated.

(Comparative Example 2-2)
A laminate type battery was prepared in the same manner as in Example 2-1, except that 1.0% by mass of vinylene carbonate was mixed without mixing phenylsilane with the electrolytic solution, and the physical properties of the battery were evaluated.

(Comparative Example 2-3)
Laminated mold in the same manner as in Example 2-1, except that 1.0% by mass of vinylene carbonate was mixed with the electrolyte and tetraethylsilane having no hydrogen-silicon (Si—H) bond was used instead of phenylsilane. A battery was prepared and the physical properties of the battery were evaluated.

  Table 2 shows the results of evaluating the physical properties of the laminate type batteries prepared in Examples 2-1 to 2-12 and Comparative Examples 2-1 to 2-3.

  As shown in Table 2, Example 2 using an electrolytic solution in which a silane derivative (phenylsilane) having a hydrogen-silicon (Si-H) bond and a polymer compound (polyvinyl formal) swollen by the electrolytic solution was mixed. In Example 1, the change in battery thickness decreased when stored at 90 ° C. for 4 hours as compared with Comparative Example 2-1 in which phenylsilane was not included in the electrolytic solution. In Example 2-1, the effect of suppressing battery expansion during high-temperature storage was slightly reduced, but the effect was small compared to Example 1-1 in which polyvinyl formal was not included in the electrolyte.

  Also, a silane derivative having a hydrogen-silicon (Si—H) bond (phenylsilane, butylsilane, hexylsilane, octadecylsilane, diphenylsilane, diethylsilane, triphenylsilane, or triethylsilane), vinylene carbonate, and polyvinyl formal are mixed. In Examples 2-2 to 2-11 in which the electrolyte solution was used, compared with Comparative Example 2-2 in which the electrolyte solution not containing a silane derivative having a hydrogen-silicon (Si—H) bond was used, the temperature was 90 ° C. The change in battery thickness when stored for 4 hours was reduced, and a high discharge capacity retention rate was maintained.

  On the other hand, instead of using a silane derivative having a hydrogen-silicon (Si-H) bond, a comparison was made using an electrolytic solution in which a silane derivative (tetraethylsilane) having no hydrogen-silicon (Si-H) bond was mixed with vinylene carbonate. In Example 2-3, compared with Comparative Example 2-2 using an electrolytic solution in which vinylene carbonate and polyvinyl formal were mixed, the change in battery thickness when stored at 90 ° C. for 4 hours was increased, and the discharge capacity retention rate was increased. Decreased.

  From these, together with a silane derivative having a hydrogen-silicon (Si-H) bond, by mixing a vinylene carbonate and a polymer compound swollen by an electrolytic solution into the electrolytic solution, while suppressing battery expansion during high-temperature storage, It was found that excellent charge / discharge efficiency can be maintained.

  Further, in Example 2-3 in which the concentration of phenylsilane in the electrolytic solution was 0.1% by mass, and in Example 2-4 in which 0.7% by mass was used, Example 2-2 in which the concentration was 0.5% by mass and Similarly, the change in battery thickness when stored at 90 ° C. for 4 hours was reduced as compared with Comparative Example 2-2 in which the electrolytic solution did not contain phenylsilane and contained vinylene carbonate. On the other hand, in Example 2-12 in which the concentration of phenylsilane in the electrolytic solution was 1.0% by mass, the change in battery thickness when stored at 90 ° C. for 4 hours decreased, but the discharge capacity retention rate after 300 cycles Decreased significantly. Therefore, even when a polymer compound that swells with the electrolytic solution is added to the electrolytic solution, the concentration of the silane derivative having a hydrogen-silicon (Si—H) bond in the electrolytic solution is 0.1 to 0.7 mass. It was found that good results could be obtained within the range of%.

<Examples 3-1 to 3-12 and Comparative Examples 3-1 to 3-3>
(Example 3-1)
A laminate type battery was prepared in the same manner as in Example 1-1 except that 1.0% by mass of polyacrylic acid ester was swollen in the electrolytic solution and diethyl carbonate was reduced by that amount, and the physical properties of the battery were evaluated.

(Examples 3-2 to 3-4)
A laminated battery was prepared in the same manner as in Example 3-1, except that 1.0% by mass of vinylene carbonate was mixed with the electrolytic solution, and the concentration of phenylsilane was changed to the concentration shown in Table 3, and the physical properties of the battery were evaluated. did.

(Examples 3-5 to 3-11)
Lamination was carried out in the same manner as in Example 3-1, except that 1.0% by mass of vinylene carbonate was mixed with the electrolytic solution, and the composition of the silane derivative having a hydrogen-silicon (Si—H) bond was changed to the composition shown in Table 3. Type batteries were prepared and the physical properties of the batteries were evaluated.

(Example 3-12)
A laminated battery was prepared in the same manner as in Example 3-1, except that 1.0% by mass of vinylene carbonate was mixed with the electrolytic solution, and the concentration of phenylsilane was changed to the concentration shown in Table 3, and the physical properties of the battery were evaluated. did.

(Comparative Example 3-1)
A laminate type battery was produced in the same manner as in Example 3-1, except that phenylsilane was not mixed with the electrolytic solution and diethyl carbonate was increased by that amount, and the physical properties of the battery were evaluated.

(Comparative Example 3-2)
A laminate type battery was prepared in the same manner as in Example 3-1, except that 1.0% by mass of vinylene carbonate was mixed without mixing phenylsilane with the electrolytic solution, and the physical properties of the battery were evaluated.

(Comparative Example 3-3)
Laminated mold in the same manner as in Example 3-1, except that 1.0% by mass of vinylene carbonate was mixed with the electrolytic solution, and tetraethylsilane having no hydrogen-silicon (Si—H) bond was used instead of phenylsilane. A battery was prepared and the physical properties of the battery were evaluated.

  Table 3 shows the results of evaluating the physical properties of the laminate type batteries prepared in Examples 3-1 to 3-12 and Comparative Examples 3-1 to 3-3.

  As shown in Table 3, Examples using an electrolytic solution in which a silane derivative (phenylsilane) having a hydrogen-silicon (Si-H) bond and a polymer compound (polyacrylic ester) swollen by the electrolytic solution were mixed As for 3-1, the change of the battery thickness decreased when it preserve | saved at 90 degreeC for 4 hours compared with the comparative example 3-1 which does not contain phenylsilane in electrolyte solution. In Example 3-1, the effect of suppressing battery expansion during high-temperature storage was slightly reduced compared to Example 1-1 in which polyvinyl formal was not included in the electrolytic solution, but the effect was small.

  Also, a silane derivative having a hydrogen-silicon (Si—H) bond (phenylsilane, butylsilane, hexylsilane, octadecylsilane, diphenylsilane, diethylsilane, triphenylsilane, or triethylsilane), vinylene carbonate, and polyvinyl formal are mixed. In Examples 3-2 to 3-11 using the prepared electrolyte solution, compared with Comparative Example 3-2 using an electrolyte solution that does not contain a silane derivative having a hydrogen-silicon (Si—H) bond, 90 ° C. The change in battery thickness when stored for 4 hours was reduced, and a high discharge capacity retention rate was maintained.

  On the other hand, instead of using a silane derivative having a hydrogen-silicon (Si-H) bond, a comparison was made using an electrolytic solution in which a silane derivative (tetraethylsilane) having no hydrogen-silicon (Si-H) bond was mixed with vinylene carbonate. In Example 3-3, compared with Comparative Example 3-2 using an electrolytic solution in which vinylene carbonate and polyvinyl formal are mixed, the change in battery thickness when stored at 90 ° C. for 4 hours is increased, and the discharge capacity retention rate is increased. Decreased.

  From these, together with a silane derivative having a hydrogen-silicon (Si-H) bond, by mixing a vinylene carbonate and a polymer compound swollen by an electrolytic solution into the electrolytic solution, while suppressing battery expansion during high-temperature storage, It was found that excellent charge / discharge efficiency can be maintained.

  In Example 3-3 in which the concentration of phenylsilane in the electrolytic solution was 0.1% by mass, and in Example 3-4 in which 0.7% by mass was used, Example 3-2 in which 0.5% by mass was used. Similarly, compared with Comparative Example 3-2 in which the electrolytic solution does not contain phenylsilane and contains vinylene carbonate, the change in battery thickness when stored at 90 ° C. for 4 hours was reduced. On the other hand, in Example 3-12 in which the concentration of phenylsilane in the electrolytic solution was 1.0 mass%, the change in battery thickness when stored at 90 ° C. for 4 hours decreased, but the discharge capacity retention rate after 300 cycles Decreased significantly. Therefore, as described above, even when a polymer compound that swells with an electrolytic solution is added to the electrolytic solution, the concentration of the silane derivative having a hydrogen-silicon (Si—H) bond in the electrolytic solution is 0.1. From the results, it was found that good results can be obtained within the range of 0.7 mass%.

<Examples 4-1 to 4-12, Comparative Examples 4-1 to 4-3>
(Example 4-1)
A laminate type battery was prepared in the same manner as in Example 1-1 except that a separator having a thickness of 7 μm and a separator coated with 2 μm of polyvinylidene fluoride on both sides was used, and the physical properties of the battery were evaluated.

(Examples 4-2 to 4-4)
A laminate type battery was prepared in the same manner as in Example 4-1, except that 1.0% by mass of vinylene carbonate was mixed into the electrolytic solution and the phenylsilane concentration was changed to the concentration shown in Table 4, and the physical properties of the battery were evaluated. did.

(Examples 4-5 to 4-11)
Lamination was carried out in the same manner as in Example 4-1, except that 1.0% by mass of vinylene carbonate was mixed with the electrolytic solution, and the composition of the silane derivative having a hydrogen-silicon (Si—H) bond was changed to the composition shown in Table 4. Type batteries were prepared and the physical properties of the batteries were evaluated.

(Example 4-12)
A laminate type battery was prepared in the same manner as in Example 4-1, except that 1.0% by mass of vinylene carbonate was mixed into the electrolytic solution and the phenylsilane concentration was changed to the concentration shown in Table 4, and the physical properties of the battery were evaluated. did.

(Comparative Example 4-1)
A laminate type battery was prepared in the same manner as in Example 4-1, except that phenylsilane was not mixed with the electrolytic solution and diethyl carbonate was increased by that amount, and the physical properties of the battery were evaluated.

(Comparative Example 4-2)
A laminate type battery was prepared in the same manner as in Example 4-1, except that 1.0% by mass of vinylene carbonate was mixed without mixing phenylsilane with the electrolytic solution, and the physical properties of the battery were evaluated.

(Comparative Example 4-3)
Laminated mold in the same manner as in Example 4-1, except that 1.0% by mass of vinylene carbonate was mixed with the electrolyte and tetraethylsilane having no hydrogen-silicon (Si—H) bond was used instead of phenylsilane. A battery was prepared and the physical properties of the battery were evaluated.

  Table 4 shows the results of evaluating the physical properties of the laminate type batteries produced in Examples 4-1 to 4-12 and Comparative Examples 4-1 to 4-3.

  As shown in Table 4, Example 4 using an electrolytic solution in which a silane derivative (phenylsilane) having a hydrogen-silicon (Si-H) bond and a polymer compound (polyvinylidene fluoride) swollen by the electrolytic solution was used. -1 showed a decrease in battery thickness change when stored at 90 ° C. for 4 hours, compared to Example 1-1 in which polyvinylidene fluoride was not included in the electrolyte. From this, it was found that by using an electrolyte containing polyvinylidene fluoride together with a silane derivative having a hydrogen-silicon (Si—H) bond, the effect of suppressing battery expansion during high-temperature storage is improved.

  Silane derivatives having a hydrogen-silicon (Si—H) bond (phenylsilane, butylsilane, hexylsilane, octadecylsilane, diphenylsilane, diethylsilane, triphenylsilane, or triethylsilane), vinylene carbonate, and polyvinylidene fluoride In Examples 4-2 to 4-11 using the mixed electrolytic solution, compared with Comparative Example 4-2 using an electrolytic solution not containing a silane derivative having a hydrogen-silicon (Si-H) bond, The change in battery thickness when stored at 4 ° C. for 4 hours decreased, indicating a high discharge capacity retention rate.

  On the other hand, instead of using a silane derivative having a hydrogen-silicon (Si-H) bond, a comparison was made using an electrolytic solution in which a silane derivative (tetraethylsilane) having no hydrogen-silicon (Si-H) bond was mixed with vinylene carbonate. In Example 4-3, compared with Comparative Example 4-2 using an electrolytic solution in which vinylene carbonate and polyvinyl formal are mixed, the change in battery thickness when stored at 90 ° C. for 4 hours is increased, and the discharge capacity retention rate is increased. Decreased.

  From these, by mixing vinylene carbonate and polyvinylidene fluoride with electrolyte together with silane derivative having hydrogen-silicon (Si-H) bond, excellent charge and discharge while suppressing battery expansion during high temperature storage It turns out that efficiency is obtained.

  Further, in Example 4-3 in which the concentration of phenylsilane in the electrolytic solution was 0.1% by mass and Example 4-4 in which 0.7% by mass was used, Example 4-2 in which the concentration was 0.5% by mass and Similarly, the change in battery thickness when stored at 90 ° C. for 4 hours was reduced as compared with Comparative Example 4-2 in which the electrolytic solution did not contain phenylsilane and contained vinylene carbonate. On the other hand, in Example 4-12 in which the concentration of phenylsilane in the electrolyte solution was 1.0 mass%, the change in battery thickness when stored at 90 ° C. for 4 hours decreased, but the discharge capacity retention rate after 300 cycles Decreased significantly. Therefore, as described above, even when a polymer compound that swells with an electrolytic solution is added to the electrolytic solution, the concentration of the silane derivative having a hydrogen-silicon (Si—H) bond in the electrolytic solution is 0.1. From the results, it was found that good results can be obtained within the range of 0.7 mass%.

  While the present invention has been described with reference to the embodiments, it is needless to say that the present invention is not limited to the above embodiments and can be variously modified.

It is a disassembled perspective view showing the structure of the secondary battery which concerns on one embodiment of this invention. It is sectional drawing showing the structure along the II line of the winding electrode body shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 20 ... Winding electrode body, 23 ... Positive electrode, 23A ... Positive electrode collector, 23B ... Positive electrode active material layer, 24 ... Negative electrode, 24A ... Negative electrode collector, 24B ... Negative electrode active material layer, 25 ... Separator, 21 ... Positive electrode Lead, 22 ... negative electrode lead, 26 ... electrolyte layer, 27 ... protective tape, 30 ... exterior member, 31 ... adhesion film.

Claims (15)

A non-aqueous electrolyte battery comprising an outer container formed of a laminate film, an electrode body formed by laminating a positive electrode housed in the outer container and a negative electrode made of a carbon material via a separator, and an electrolytic solution There,
The said electrolyte solution contains at least 1 sort (s) of the silane derivative which has a hydrogen-silicon bond represented by following Formula (1)-(6), The non-aqueous electrolyte battery characterized by the above-mentioned.

[In the formulas (1) to (3), R _{1 to} R ₇ represent C _m H _{2m + 1} (1 ≦ m ≦ 18). Also, shown in the formula _{(4) ~ (6),} R 1 ~R 15 is _C m _{H 2m +} 1 a (0 ≦ m ≦ 4). ]   The non-aqueous electrolyte secondary battery according to claim 1, wherein the content of the silane derivative in the electrolyte is 0.1 to 0.7 mass%.   The non-aqueous electrolyte battery according to claim 1, wherein the silane derivative is at least one of phenylsilane, butylsilane, hexylsilane, octadecylsilane, diphenylsilane, diethylsilane, triphenylsilane, and triethylsilane. .   The non-aqueous electrolyte battery according to claim 1, wherein the electrolytic solution contains a carbonic acid ester having a carbon-carbon multiple bond.   The nonaqueous electrolyte battery according to claim 1, wherein the carbonate ester is vinylene carbonate.   5. The non-aqueous electrolyte battery according to claim 4, wherein the content of the carbonate in the electrolytic solution is 0.1% by mass or more and 2.0% by mass or less.   The nonaqueous electrolyte battery according to claim 1, comprising a polymer compound that swells with the electrolyte.   The non-aqueous electrolyte battery according to claim 7, wherein the polymer compound is polyvinylidene fluoride.   The non-aqueous electrolyte battery according to claim 7, wherein a mass ratio of the polymer compound to the electrolytic solution is 1:10 to 1:50. A battery electrolyte comprising at least one silane derivative having a hydrogen-silicon bond represented by the following formulas (1) to (6):

[In the formulas (1) to (3), R _{1 to} R ₇ represent C _m H _{2m + 1} (1 ≦ m ≦ 18). Also, shown in the formula _{(4) ~ (6),} R 1 ~R 15 is _C m _{H 2m +} 1 a (0 ≦ m ≦ 4). ]   The battery electrolyte solution according to claim 10, wherein the content of the silane derivative is 0.1 to 0.7 mass%.   11. The battery electrolyte according to claim 10, wherein the silane derivative is at least one of phenyl silane, butyl silane, hexyl silane, octadecyl silane, diphenyl silane, diethyl silane, triphenyl silane, and triethyl silane.   The battery electrolyte according to claim 10, wherein the electrolyte contains a carbonic acid ester having a carbon-carbon multiple bond.   The battery electrolyte according to claim 10, wherein the carbonate ester is vinylene carbonate.   11. The battery electrolyte according to claim 10, wherein a content of the carbonate is 0.1% by mass or more and 2.0% by mass or less.

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