JP2005063848A - Manufacturing method and manufacturing device of battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method and a manufacturing device of a battery capable of improving a battery characteristic and productivity. <P>SOLUTION: An assembly equipped with an electrolyte, a monomer and a polymerization initiator along with a positive electrode and a negative electrode is formed. A gel electrolyte is formed by polymerizing the monomer and the assembly is shaped by applying heat and pressure below 10 MPa to the assemble by a heating plate having a heat source incorporated and heated by the heat source. The heating plate is further rapidly heated by the incorporated heat source as compared with heating it through radiant heat or convection of air, and a sufficient heat quantity is supplied to the assembly in a short time. Thereby, the assembly is rapidly heated to a temperature suitable for the polymerization without degrading electrolyte salt, and formation of the gel electrolyte is promptly completed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a battery manufacturing method for applying heat and pressure to an assembly including an electrolyte, a monomer, and a polymerization initiator together with a positive electrode and a negative electrode, and a battery manufacturing apparatus used therefor.

  In recent years, portable electronic devices have been developed one after another, and secondary batteries have become an important position as the power source. Moreover, since the secondary battery is not disposable, it is preferable in terms of the global environment and is being used more than the primary battery. Recently, portable electronic devices are required to be small and light, and accordingly, this secondary battery is also small in order to accommodate the storage space in the device, and the weight of the device is reduced. It is required to be lightweight so as not to increase as much as possible.

  Secondary batteries that meet these requirements include lead batteries, nickel-cadmium batteries, nickel metal hydride batteries, or lithium ion secondary batteries. Among these, polymer lithium ion secondary batteries that are lightweight and have high energy density and high output density Is useful.

  As an electrolyte of a polymer lithium ion secondary battery, a gel electrolyte, which is also called a solid electrolyte or a semisolid electrolyte, in which an electrolytic solution is gelled with a polymer compound is used. For example, there are the following four methods for producing the gel electrolyte. The first is a method of heating to dissolve the polymer compound in the electrolytic solution to prepare a sol-like polymer solution, and then cooling the sol-like polymer solution, and the second is a method of cooling the polymer compound and electrolysis. This is a method of volatilizing the mixed solvent after preparing a sol polymer solution mixed with the liquid using a mixed solvent. Third, after dissolving the polymer compound in the diluting solvent, the diluting solvent is volatilized. A polymer matrix having a sponge structure and impregnating the polymer matrix with an electrolytic solution. Fourth, heating the monomer in the electrolyte composition including the electrolytic solution, the monomer, and the polymerization initiator. Or it is the method of superposing | polymerizing with light.

  Among these, the fourth method has an advantage that a battery manufacturing process using an existing electrolytic solution can be applied because the electrolyte composition may be poured into the positive electrode and the negative electrode. In addition, since there is no need to volatilize the solvent or dissolve the polymer compound as in the first, second or third methods, a volatile substance can be used as the solvent, or the polymer compound and the solvent There is also an advantage that the degree of freedom is high in that it is not necessary to consider compatibility. In particular, it is more desirable to polymerize by heating, considering that the constituent material of the battery is opaque.

In the fourth method, for example, when an aluminum laminate film or the like is used for the exterior member for the purpose of reducing the thickness or weight of the battery, it is necessary to shape the battery before the gel electrolyte is solidified. This is because if the surface of the battery is not smooth, the thickness of the battery will be locally thick and will not fit in the appliance. Therefore, conventionally, an assembly including an electrolyte, a monomer, and a polymerization initiator together with a positive electrode and a negative electrode is generally sandwiched between a pair of metal plates, and the battery is shaped while polymerizing the monomer in an oven (for example, , See Patent Document 1).
JP 2003-109665 A (paragraph 0026) JP 2002-298799 A

  However, as in the past, when the assembly is sandwiched between a pair of metal plates and heated in an oven, the heat is transferred to the metal plate and then to the assembly, so that it takes time for the amount of heat necessary for polymerization to be transferred to the assembly. As a result, it takes a long time to complete the polymerization. In addition, there is a problem that a chemical reaction such as decomposition of the electrolyte salt that impairs battery performance occurs.

  This invention is made | formed in view of this problem, The objective is to provide the manufacturing method and manufacturing apparatus of a battery which can improve a battery characteristic and productivity.

  The method for producing a battery according to the present invention includes a step of forming an assembly including an electrolyte, a monomer, and a polymerization initiator together with a positive electrode and a negative electrode, and a heating plate with a built-in heat source for the assembly. And a step of applying the pressure.

  The battery manufacturing apparatus according to the present invention heats and pressurizes an assembly including an electrolyte, a monomer, and a polymerization initiator together with a positive electrode and a negative electrode, and has a built-in heat source. A heating plate for applying the pressure of

  In the battery manufacturing method of the present invention, after an assembly including an electrolyte, a monomer, and a polymerization initiator is formed together with a positive electrode and a negative electrode, heat and 10 MPa are applied to the assembly by a heating plate incorporating a heat source. Less than pressure is applied to polymerize the monomer to form a gel electrolyte and shape the assembly.

  In the battery manufacturing apparatus of the present invention, since the heating plate incorporates a heat source, the assembly is heated in a short time and shaped by pressure by the heating plate heated by the heat source, thereby improving dimensional accuracy. To do.

  According to the method and apparatus for manufacturing a battery of the present invention, heat and a pressure of less than 10 MPa are applied to the assembly by a heating plate having a built-in heat source, so that heating is performed through radiant heat or air convection. Compared to this, a sufficient amount of heat can be supplied to the assembly in a short time. Therefore, the assembly can be heated quickly without deteriorating the electrolyte salt, and the characteristics and productivity of the battery can be significantly improved. In addition, the assembly can be satisfactorily shaped without breakage, and the interelectrode distance between the positive electrode and the negative electrode can be shortened to improve the dimensional characteristics and battery capacity in appearance.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(First embodiment)
FIG. 1 shows the flow of the battery manufacturing method according to the first embodiment of the present invention, and FIGS. 2 to 6 show the steps in order. First, an assembly including an electrolytic solution, a monomer, and a polymerization initiator is formed together with the positive electrode 11 and the negative electrode 12 (step 110). Specifically, first, as shown in FIG. 2A, the positive electrode 11 is manufactured (step S111). For example, when a particulate positive electrode active material is used, the positive electrode active material is mixed with a conductive agent such as carbon black or graphite and a binder such as polyvinylidene fluoride or tetrafluoroethylene as necessary. An agent is prepared and dispersed in a dispersion medium such as N-methylpyrrolidone to prepare a positive electrode mixture coating liquid. As the positive electrode active material, for example, one or more of positive electrode materials capable of inserting and releasing lithium are used. As a positive electrode material capable of inserting and releasing lithium, for example, a composite oxide of lithium and a transition metal element is preferable. This is because some composite oxides can obtain a high voltage and a high energy density. Examples of the composite oxide include LiCoO ₂ , LiNiO _{2, and} LiMn ₂ O ₄ . _{Further, LiNi x Co 1-x O} 2 in which a part has been replaced with other elements of these transition metal elements (0 <x <1) may also be mentioned, such as. Specific examples of LiNi _x Co _1-x O ₂ include LiN _0.5 Co _0.5 O _{2 and} LiNi _0.8 Co _0.2 O ₂ .

  After that, a positive electrode current collector 11A having a pair of opposed surfaces is prepared, and a positive electrode mixture coating liquid is applied to both surfaces or one surface of the positive electrode current collector 11A, dried, and compression molded to form a positive electrode active material layer 11B. Form. For the positive electrode current collector 11A, for example, a metal foil such as an aluminum (Al) foil is used.

  Further, as shown in FIG. 2B, the negative electrode 12 is manufactured (step S111). For example, when a particulate negative electrode active material is used, the negative electrode active material is mixed with a conductive agent such as carbon black or graphite and a binder such as polyvinylidene fluoride or styrene butadiene rubber as necessary. An agent is prepared and dispersed in a dispersion medium such as N-methylpyrrolidone to prepare a negative electrode mixture coating liquid. As the negative electrode active material, for example, one or more of negative electrode materials capable of inserting and releasing lithium, lithium alloys, and metallic lithium are used.

  Examples of the negative electrode material capable of inserting and releasing lithium include a carbon material. Examples of the carbon material include graphite, non-graphitizable carbon, and graphitizable carbon.

  Examples of the negative electrode material capable of inserting and releasing lithium also include simple elements, alloys or compounds of metal elements or metalloid elements capable of forming an alloy with lithium. In addition to the alloy composed of two or more metal elements, the alloy includes an alloy composed of one or more metal elements and one or more metalloid elements. There are structures in which a solid solution, a eutectic (eutectic mixture), an intermetallic compound, or two or more of them coexist.

  Among them, a simple substance, alloy or compound of a group 14 metal element or metalloid element in the long-period periodic table is preferable, and silicon (Si) or tin (Sn), or an alloy or compound thereof is particularly preferable. These may be crystalline or amorphous.

  After that, a negative electrode current collector 12A having a pair of opposing surfaces is prepared, a negative electrode mixture coating solution is applied to both surfaces or one surface of the negative electrode current collector 12A, dried, and compression molded to be used as the negative electrode active material layer 12B. Form. For the negative electrode current collector 12A, for example, a metal foil such as a copper (Cu) foil, a nickel (Ni) foil, or a stainless steel foil is used.

  Next, as shown in FIG. 3, after attaching the positive electrode lead 11C to the positive electrode 11 and attaching the negative electrode lead 12C to the negative electrode 12, the separator 13, the positive electrode 11, the separator 13, and the negative electrode 12 are sequentially laminated and wound. The protective tape 14 is adhered to the outermost peripheral portion to form the wound electrode body 10 (step S112). At that time, a strip-shaped metal piece made of aluminum or the like is used for the positive electrode lead 11C, and a strip-shaped metal piece made of nickel or the like is used for the negative electrode lead 12C. Any separator 13 is used as long as it is electrically stable, chemically stable to a positive electrode active material, a negative electrode active material, or a solvent described later, and has an insulating property. Also good. For example, a polymer non-woven fabric, a porous film, a glass or ceramic fiber in the form of paper can be used, and a plurality of these may be laminated. In particular, it is preferable to use a porous polyolefin film, and a composite of this with a heat-resistant material made of polyimide, glass or ceramic fibers may be used.

  Subsequently, as shown in FIG. 4, the wound electrode body 10 is sandwiched between the exterior members 20, and the outer peripheral edge except for one side is heat-sealed into a bag shape, and the wound electrode body 10 is placed inside the exterior member 20. (Step S113). For the exterior member 20, for example, a laminate film in which two or more insulating layers and metal layers are laminated and bonded together is disposed so that the insulating layer is on the inner side. The constituent material of the inner insulating layer is not particularly limited as long as it is a material having adhesiveness to the positive electrode lead 11C and the negative electrode lead 12C. However, polyethylene, polypropylene, modified polyethylene, modified polypropylene, copolymers thereof, and the like can be used. Polyolefin resins are preferred because they can reduce permeability and are excellent in airtightness. In addition, as a constituent material of the outer insulating layer, for example, nylon is preferable from the viewpoint that strength against tearing and piercing can be increased. As a constituent material of the metal layer, for example, aluminum, stainless steel, nickel, iron (Fe) or the like formed into a foil shape or a plate shape can be given.

  At this time, in order to prevent a short circuit between the positive electrode lead 11C and the negative electrode lead 12C and the exterior member 20, or a decrease in airtightness, the positive electrode lead 11C and the negative electrode lead 12C and the exterior member 20 For example, an adhesive film 21 made of a resin such as propylene exhibiting adhesiveness may be inserted.

  After that, an electrolyte composition containing an electrolytic solution, a monomer, a polymerization initiator, and, if necessary, other materials such as a polymerization inhibitor is prepared. The electrolytic solution contains a solvent and an electrolyte salt dissolved in the solvent. As the solvent, for example, any one or more of a high dielectric constant solvent having a relatively high dielectric constant and boiling point and any one or more of a low viscosity solvent having a relatively low viscosity are mixed. It is desirable to use one. Since the high dielectric constant solvent dissolves the electrolyte salt well, the number of ions in the solvent can be increased. However, since the viscosity is high, the mobility of ions is small. On the other hand, a low-viscosity solvent has high ion mobility due to low viscosity, but it is difficult to dissolve the electrolyte salt. Therefore, the ion conductivity can be increased by using a mixture of a high dielectric constant solvent and a low viscosity solvent.

  High dielectric constant solvents include cyclic carbonates or cyclic lactones, such as ethylene carbonate, propylene carbonate, γ-butyrolactone, γ-valerolactone, or those obtained by substituting these hydrogens with halogens. Is mentioned. Examples of low-viscosity solvents include chain carbonic acid esters, and specific examples include dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, dipropyl carbonate, ethyl propyl carbonate, or those obtained by substituting these hydrogens with halogens. It is done.

As the electrolyte salt, for example, one or more lithium salts are used. Examples of the lithium salt include lithium hexafluorophosphate (LiPF ₆ ), lithium tetrafluoroborate (LiBF ₄ ), lithium bis (trifluoromethanesulfonyl) imide lithium (LiN (CF ₃ SO ₂ ) ₂ ), bis ( Examples thereof include trifluoroethanesulfonyl) imidolithium (LiN (C ₂ F ₅ SO ₂ ) ₂ ) or lithium perchlorate (LiClO ₄ ).

  The monomer is for holding the electrolytic solution by polymerization and forming a gel electrolyte. As the monomer, for example, one having an ether group or an ester group can be used. Especially, what has an acrylate group or a methacrylate group at the terminal is preferable. Specific examples include compounds represented by Chemical Formula 1, Chemical Formula 2, Chemical Formula 3, Chemical Formula 4, Chemical Formula 5, Chemical Formula 6 or Chemical Formula 7. Any one of the monomers may be used alone, or two or more monomers may be mixed and used.

（化７において、ｎは１〜３の整数である。）

(In Chemical formula 7, n is an integer of 1 to 3.)

  As the polymerization initiator, any thermal polymerization initiator such as diacyl peroxide, peroxy carbonate, peroxy ester, peroxy ketal, dialkyl peroxide, hydroperoxide or azo compound may be used. Good. Specifically, for example, t-butylperoxyneodecanoate, t-hexylperoxyneodecanoate, 1,1,3,3-tetramethylbutylperoxyneodecanoate, t-butylperoxy Pivalate, t-hexylperoxypivalate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, t-butylperoxy Examples include isobutyrate, t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxylaurate, t-butylperoxyacetate, 2,2-azobis-isobutyronitrile, and the like. It is done. Any one kind of polymerization initiators may be used alone, or two or more kinds thereof may be mixed and used.

  The electrolyte solution, the monomer and the polymerization initiator in the electrolyte composition are conveniently used in a weight ratio of about 4% to 6% of the monomer and about 500 ppm to 1000 ppm of the polymerization initiator with respect to the electrolyte solution. In many cases, it is necessary to use an optimum composition depending on the physical properties and structure of the monomer. The first reason is that if the monomer is too small, the strength and liquid retention of the gel electrolyte formed in the subsequent process will be lowered. Second, if the amount of the monomer is excessive, the ionic conductivity of the gel electrolyte is lowered, and the viscosity of the electrolyte composition is increased, which causes a harmful effect on pouring or impregnating the wound electrode body 10 with the electrolyte composition. It is. Third, if the polymerization initiator is too small, the polymerization of the polymerizable compound may not be sufficiently completed in time. Fourth, if there are too many polymerization initiators, there is a possibility that an adverse effect due to the oxidizing action of the unreacted polymerization initiator may occur.

  Next, the electrolyte composition is poured from the opening of the exterior member 20 into the wound electrode body 10, specifically, the positive electrode 11, the negative electrode 12, and the separator 13 (step S114). Subsequently, as shown in FIG. 5, the opening of the exterior member 20 is heat-sealed and sealed in a vacuum atmosphere. (Step S115). Thereby, the assembly 1 is formed.

  After forming the assembly 1, heat and pressure are applied to the assembly 1 by the manufacturing apparatus shown in FIG. 6 (step S120). The manufacturing apparatus 40 includes a pair of heating plates 41A and 41B that incorporate heat sources 42A and 42B. The manufacturing apparatus 40 also includes a pressing member 43 that presses the heating plate 41A toward the heating plate 41B, a control unit 44 that controls the output of the heat sources 42A and 42B and the pressing force of the pressing member 43, and the heating plates 41A and 41B. The parallelism control part 45 which controls the parallelism of this, and the pressing force transmission member 46 which transmits the pressing force from the pressing member 43 to the heating plate 41A are provided.

  The heating plates 41A and 41B are for polymerizing the monomer by heating the assembly 1, and for pressurizing and shaping the assembly 1 and are made of, for example, a metal plate. The pressure applied to the assembly 1 by the heating plates 41A and 41B needs to be less than 10 MPa. This is because if the pressure is 10 MPa or more, the contents of the assembly 1 may be crushed or the exterior member 20 may be damaged. It is preferable that the heating plates 41A and 41B, particularly the heating plate 41A on the pressing member 43 side, have a thickness sufficient to ensure the strength as a plate. The heat conductivity of the heating plates 41A and 41B is not a problem as long as they are made of metal, and the type of metal is not particularly limited. Further, the size of the heating plates 41 </ b> A and 41 </ b> B is not particularly limited as long as it is larger than the size of the assembly 1.

  The heat capacity of the heating plates 41 </ b> A and 41 </ b> B needs to be sufficiently larger than the heat capacity of the assembly 1, and is preferably 40 times or more the heat capacity of the assembly 1, for example. As will be described later, in the present embodiment, the temperature of the heating plates 41A and 41B is set in the range of 50 ° C. or higher and 110 ° C. or lower, so that the temperature rise of the assembly 1 from room temperature does not exceed 100 ° C. . Therefore, if the heat capacity of the heating plates 41A and 41B is 40 times or more the heat capacity of the assembly 1, the temperature drop of the heating plates 41A and 41B when the temperature of the assembly 1 rises by 100 ° C. can be suppressed to 3 ° C. or less. Because you can.

  The heat sources 42A and 42B are constituted by, for example, heating wires. The heat sources 42 </ b> A and 42 </ b> B may be arranged so that the heating plates 41 </ b> A and 41 </ b> B are uniformly heated, and the shape and arrangement thereof are not particularly limited.

  It is preferable that the output Y of the heat sources 42A and 42B be within the range represented by the following formula 1, where X is the heat capacity of the assembly 1. This is because the necessary amount of heat can be supplied to the assembly 1 within 15 seconds, and the heating time can be shortened to increase the productivity.

(Equation 1)
Y (W) ≧ X (J / K) × 100 (K) ÷ 15 (seconds)

  The pressing member 43 allows the heating plates 41A and 41B to pressurize the assembly 1 by, for example, lowering and pressing the heating plate 41A toward the fixed heating plate 41B. As the parallelism control unit 45, for example, a mechanism described in Patent Document 2 can be used. The pressure transmission member 46 is a rod-shaped member disposed between the parallelism control unit 45 and the heating plate 41A.

  In this manufacturing apparatus 40, the assembly 1 is sandwiched between heating plates 41A and 41B heated by heat sources 42A and 42B, and heat and a pressure of less than 10 MPa are applied. Thereby, the monomer is polymerized to form a gel electrolyte and the assembly 1 is shaped. Here, since the heating plates 41A and 41B have built-in heat sources 42A and 42B, they are heated much faster than being heated through radiant heat or air convection. The assembly 1 is supplied with a sufficient amount of heat in a short time by the heating plates 41A and 41B heated by the heat sources 42A and 42B. Therefore, the assembly 1 is rapidly heated to a temperature suitable for polymerization without deterioration of the electrolyte salt to form a gel electrolyte. In addition, the assembly 1 is well shaped without being crushed or damaging the exterior member 20, and the distance between the positive electrode 11 and the negative electrode 12 is shortened. Will increase.

  At this time, the temperature of the heating plates 41A and 41B is not less than (the 10-hour half-life temperature of the polymerization initiator—8 ° C.) or more (the 10-hour half-life temperature of the polymerization initiator + 50 ° C.) or the lower temperature of 120 ° C. The pressure is preferably in the range of 0.1 MPa to 3 MPa, and the time for applying heat and pressure to the assembly 1 is preferably 1 minute to 10 minutes. This is because the polymerization can sufficiently proceed and the deterioration of the electrolyte salt can be prevented. Further, the adhesion between the gel electrolyte and the positive electrode 11, the negative electrode 12 and the separator 13, the adhesion between the positive electrode 11 and the negative electrode 12 and the separator 13, or the adhesion between the positive electrode 11 and the negative electrode 12 and the separator 13 via the gel electrolyte. It is because it can improve.

  Thus, the battery according to the present embodiment is completed.

  As described above, in the present embodiment, the assembly 1 including the electrolytic solution, the monomer, and the polymerization initiator is formed together with the positive electrode 11 and the negative electrode 12, and the heating plate in which the heat sources 42A and 42B are built in the assembly 1. Since heat and pressure less than 10 MPa are applied by 41A and 41B, a sufficient amount of heat can be supplied to the assembly 1 in a short time. Therefore, the assembly 1 can be quickly heated to a temperature suitable for polymerization without degrading the electrolyte salt to quickly complete the formation of the gel electrolyte, and the battery characteristics and productivity can be significantly improved. In addition, the assembly 1 can be shaped well without being damaged, the distance between the positive electrode 11 and the negative electrode 12 can be shortened, and the dimensional characteristics and battery capacity in appearance can be improved.

  Further, if the heat capacity of the heating plates 41A and 41B is set to be 40 times or more that of the assembly 1, the temperature fluctuation of the heating plates 41A and 41B can be prevented, and a sufficient amount of heat can be supplied to the assembly 1. Can do.

  Furthermore, if the outputs of the heat sources 42A and 42B are set within the range shown in Formula 1, the necessary amount of heat can be supplied to the assembly 1 within 15 seconds, and the heating time is shortened and the productivity is reduced. Can be increased.

  Further, the temperature of the heating plates 41A and 41B is set to (the polymerization initiator 10-hour half-life temperature −8 ° C.) or more (the polymerization initiator 10-hour half-life temperature + 50 ° C.) or below the lower one of 120 ° C. If the pressure is within the range of 0.1 MPa or more and 3 MPa or less and the time for applying heat and pressure to the assembly 1 is 1 minute or more and 10 minutes or less, the polymerization can proceed sufficiently. It is possible to prevent deterioration of the electrolyte salt. Also, the adhesion between the gel electrolyte and the positive electrode 11, the negative electrode 12 and the separator 13, the adhesion between the positive electrode 11 and the negative electrode 12 and the separator 13, or the adhesion between the positive electrode 11 and the negative electrode 12 and the separator 13 via the gel electrolyte. And battery characteristics can be improved.

(Second Embodiment)
FIG. 7 shows a flow of a method for manufacturing a battery according to the second embodiment of the present invention. This battery manufacturing method has the same steps as those of the first embodiment except that the steps of forming the assembly are different. Therefore, here, it demonstrates using the same code | symbol with reference to FIGS. Detailed descriptions of the same parts are omitted as appropriate.

  In the present embodiment, first, the positive electrode 11 and the negative electrode 12 are produced in the same manner as in the first embodiment (step S111). Thereafter, a monomer solution in which the monomer is dissolved in a diluting solvent is prepared. As the diluting solvent, for example, dimethyl carbonate can be used. Next, the monomer solution is applied to the positive electrode 11 and the negative electrode 12 and impregnated (step S212), and then dried. Subsequently, the positive electrode 11 and the negative electrode 12 impregnated with the monomer solution are wound through the separator 13 to form a wound electrode body (step S213), and then housed in the exterior member 20 (step S214).

  Next, for example, an electrolyte composition having the same composition as that of the first embodiment except that the monomer is not included is prepared, and the electrolyte composition is poured into the wound electrode body from the opening of the exterior member 20 ( Step S215). After that, as shown in FIG. 5, the opening of the exterior member 20 is heat-sealed and sealed (step S216) to form an assembly (step S210). After the assembly is formed, heat and pressure are applied to the assembly using the same manufacturing apparatus as in the first embodiment (step S220). Thereby, a monomer is polymerized and a gel electrolyte is formed. Thus, the battery according to the present embodiment is completed.

  As described above, in this embodiment, the positive electrode 11 and the negative electrode 12 impregnated with the monomer solution are wound through the separator 13 to form a wound electrode body, and then the electrolyte-free composition containing no monomer is wound into the wound electrode body. The exterior member 20 is sealed to form an assembly, and the assembly is heated and heated to 10 MPa by the heating plates 41A and 41B containing the heat sources 42A and 42B, as in the first embodiment. Since less pressure is applied, the assembly 1 can be rapidly heated to a temperature suitable for polymerization without degrading the electrolyte salt to form a gel electrolyte, thereby significantly improving battery characteristics and productivity. it can. Moreover, the assembly 1 can be shaped well and the dimensional characteristics and battery capacity in appearance can be enhanced.

  Further, specific embodiments of the present invention will be described in detail.

(Examples 1-1 to 1-13)
A secondary battery was manufactured by the battery manufacturing method described in the first embodiment. First, 92% by weight of lithium cobaltate (LiCoO ₂ ) as a positive electrode active material, 3% by weight of powdered polyvinylidene fluoride as a binder, and 5% by weight of powdered graphite as a conductive agent are solvents. A positive electrode mixture coating solution was prepared by kneading with N-methylpyrrolidone using a planetary mixer. Next, as shown in FIG. 2 (A), the positive electrode mixture coating liquid was uniformly applied to both surfaces of the positive electrode current collector 11A made of aluminum foil using a coating apparatus, and dried at 120 ° C. Again, it was dried at 120 ° C. for 24 hours under reduced pressure. Subsequently, the positive electrode active material layer 11B was formed by compression molding with a roll press, and then cut into a width of 48 mm and a length of 300 mm to produce the positive electrode 11 (see FIG. 1; step S111). After that, a positive electrode lead 11 </ b> C made of an aluminum ribbon was welded to the end of the positive electrode 11.

  Further, 90% by weight of mesophase-based spherical graphite as a negative electrode active material and 10% by weight of powdered polyvinylidene fluoride as a binder were kneaded by a planetary mixer using N-methylpyrrolidone as a solvent. A mixture coating solution was prepared. Next, as shown in FIG. 2 (B), the negative electrode mixture coating solution was uniformly applied to both surfaces of the negative electrode current collector 12A made of copper foil using a coating apparatus, and dried at 120 ° C. Again, it was dried at 120 ° C. for 24 hours under reduced pressure. Subsequently, the negative electrode active material layer 12B was formed by compression molding with a roll press machine, and then cut into a width of 50 mm and a length of 310 mm to produce the negative electrode 12 (see FIG. 1; step S111). After that, a negative electrode lead 12 </ b> C made of a nickel ribbon was welded to the end of the negative electrode 12.

  Next, as shown in FIG. 3, the produced positive electrode 11 and negative electrode 12 were wound through a separator 13 made of a porous polyethylene film having a thickness of 20 μm, and a protective tape 14 was applied to the outermost periphery. A rotating electrode body 10 was produced (see FIG. 1; step S112). After that, as shown in FIG. 4, the produced wound electrode body 10 was sandwiched between the exterior members 20, and the three sides were heat-sealed (see FIG. 1; step S113). At that time, an adhesion film 21 made of propylene was inserted between the positive electrode lead 11 </ b> C and the negative electrode lead 12 </ b> C and the exterior member 20. As the exterior member 20, an aluminum laminate film in which an aluminum foil is sandwiched between a pair of resin films was used.

  Moreover, the electrolyte solution, the monomer, and the polymerization initiator were mixed at a weight ratio of electrolyte solution: monomer: polymerization initiator = 95: 5: 0.5 to prepare an electrolyte composition. In the electrolyte solution, a solvent in which 20% by weight of ethylene carbonate (EC), 60% by weight of ethyl methyl carbonate (EMC), 15% by weight of dimethyl carbonate (DMC), and 5% by weight of propylene carbonate (PC) was mixed. A solution prepared by dissolving lithium hexafluorophosphate to a concentration of 1.2 mol / kg and lithium tetrafluoroborate to a concentration of 0.2 mol / kg was used. As the monomer, the compound shown in Chemical formula 1 was used, and as the polymerization initiator, as shown in Table 1, t-butyl peroxypivalate having a 10-hour half-life temperature of 55 ° C., 10-hour half-life 2,2-azobis-isobutyronitrile with a temperature of 65 ° C. or t-hexylperoxyneodecanoate with a 10 hour half-life temperature of 44.5 ° C. was used.

  Next, after pouring the electrolyte composition into the exterior member 20 (see FIG. 1; step S114), as shown in FIG. 5, the opening of the exterior member 20 is thermally fused in a vacuum atmosphere. The assembly 1 having a heat capacity of 10 J / K was formed (see FIG. 1; step S110). At that time, the pressure inside the exterior member 20 was reduced to 1/1000 atm (about 0.10 Pa).

  After that, heat and pressure were applied to the assembly 1 by the manufacturing apparatus shown in FIG. 6 (step S120). As the heating plates 41A and 41B, 10 cm × 5 cm × 2 cm copper plates were used, and the total heat capacity was 690 J / K. Further, the outputs of the heat sources 42A and 42B were 200 W, including the two heating plates 41A and 41B. The temperatures of the heating plates 41A and 41B were changed as shown in Table 1 in Examples 1-1 to 1-13. The pressure was 2 MPa and the heating / pressurization time was 5 minutes. Thereby, a secondary battery was obtained.

  Moreover, as Comparative Examples 1-1 to 1-3 for Examples 1-1 to 1-13, the assembly is sandwiched between metal plates made of stainless steel with a thickness of 6 mm having a square surface with a side of 150 mm, and 2 MPa with a spring. A secondary battery was fabricated in the same manner as in Examples 1-1 to 1-5 except that the pressure was applied and stored in an oven at 70 ° C. for the time shown in Table 1.

  Regarding the fabricated secondary batteries of Examples 1-1 to 1-13 and Comparative Examples 1-1 to 1-3, the battery capacity, load characteristics, low temperature characteristics, cycle characteristics, leakage, monomer residual ratio, and gel electrolyte The amount of hydrogen fluoride (HF) generated by the decomposition of lithium hexafluorophosphate contained in was investigated. The results are shown in Table 1. Moreover, the relationship between the temperature of the heating plates 41A and 41B of Examples 1-1 to 1-13, the battery capacity, and the initial charge / discharge efficiency is shown in FIG. 8, and the temperature, load characteristics, and cycle characteristics of the heating plates 41A and 41B The relationship is shown in FIG.

  The battery capacity is a constant current and constant voltage charge under the conditions of a current value of 0.5 C, an upper limit voltage of 4.2 V, and a charging time of 6 hours, and then a constant current discharge is performed under the conditions of a current value of 0.2 C and a final voltage of 3 V. It was set as the discharge capacity when performed. 0.5 C is a current value that discharges the rated capacity of the battery in 2 hours, and 0.2 C is a current value that discharges the rated capacity of the battery in 5 hours. In addition, when the formation state of the gel electrolyte is poor, the positive electrode active material or the negative electrode active material does not sufficiently react, or lithium is deposited on the negative electrode and falls off, which decreases the battery capacity. This battery capacity is preferably 950 mAh or more in the design specification of this embodiment.

  The initial charge / discharge efficiency was calculated as (initial discharge capacity) / (initial charge capacity) × 100 (%) from the initial charge capacity and initial discharge capacity obtained by charge / discharge under the above-described charge / discharge conditions. In addition, when lithium precipitates or an unreacted monomer remains, this numerical value decreases, leading to a decrease in battery capacity. The initial charge / discharge efficiency is preferably 92% or more in the design specification of this embodiment.

  The load characteristics were calculated as the ratio of the discharge capacity when discharged at 3C to the discharge capacity when discharged at 0.2C. The discharge capacity when discharged at 0.2 C is the discharge capacity when charging and discharging are performed under the above-described conditions. On the other hand, the discharge capacity when discharged at 3C is the discharge capacity when constant current discharge is performed under the conditions of current value 3C and end voltage 3V after charging under the above-described charging conditions. 3C is a current value for discharging the rated capacity of the battery in 20 minutes. In addition, when the formation state of a gel electrolyte is bad, ion conductivity will become low and load characteristics will fall. This load characteristic is preferably 85% or more in the design specification of this embodiment.

  The cycle characteristics were calculated as the ratio of the discharge capacity at the 500th cycle to the discharge capacity at the first cycle. The discharge capacities at the first cycle and the 500th cycle were, respectively, after a constant current and constant voltage charge under conditions of a current value of 1.0 C, an upper limit voltage of 4.2 V, and a charging time of 3 hours, a current value of 1.0 C The discharge capacities of the first cycle and the 500th discharge when constant current discharge was performed under the condition of a voltage of 3V were used. Note that the cycle characteristics are the most important and basic characteristics of a rechargeable secondary battery, and simply indicate whether or not the gel electrolyte or battery is defective. This cycle characteristic is preferably 70% or more in the design specification of this embodiment.

The amount of leakage represents the degree of gelation. The amount of liquid leakage is determined by cutting off the finished battery outer member 20 and taking out the wound electrode body, sandwiching it from above and below with a 3 mm thick paper towel, and applying a pressure of 60 kgf / cm ² (about 6 MPa) at room temperature with a press. It was determined from the measured value of the battery element before and after pressurization. At that time, when there was a deposit on the wound electrode body taken out from the exterior member 20, the deposit was removed as necessary. The amount of leakage is preferably 0.1% or less of the weight of the battery in the design specifications of this embodiment.

  The monomer residual ratio represents the degree of gelation as well as the amount of leakage. This monomer residual rate was examined by quantifying the residual monomer by GPC (Gel permeation chromatography) method. This monomer residual ratio is preferably 0.1% or less in the design specifications of this example.

  The amount of hydrogen fluoride represents the degree of side reaction. The amount of hydrogen fluoride was examined by disassembling the battery, collecting the gel electrolyte, and obtaining it by ice temperature titration using an alkali. The amount of hydrogen fluoride is preferably 20% by weight or less in the gel electrolyte according to the design specification of this example.

  As is apparent from Table 1, according to Examples 1-1 to 1-13, even when heating was performed for a short time, there was little occurrence of liquid leakage, residual monomer and hydrogen fluoride, and each battery characteristic was also good. On the other hand, in Comparative Example 1-1, there were a relatively large amount of liquid leakage, residual monomer and hydrogen fluoride, and the battery capacity, initial charge / discharge efficiency and cycle characteristics were poor. This is because the polymerization is difficult to proceed by heating in a short time in an oven, and the unreacted monomer causes a side reaction or the electrolyte solution flows because gelation has not progressed. This is thought to be due to the fact that no gel electrolyte was present at the interface. Further, in Comparative Examples 1-2 and 1-3, there were few liquid leaks and residual monomers, but a large amount of hydrogen fluoride was generated by heating for a long time, resulting in poor initial charge / discharge efficiency and cycle characteristics. .

  That is, it was found that the battery characteristics can be improved if heat and pressure are applied to the assembly 1 by the heating plates 41A and 41B incorporating the heat sources 42A and 42B.

  Further, as is apparent from Table 1, FIG. 8 and FIG. 9, the battery capacity, initial charge / discharge efficiency, load characteristics and cycle characteristics are all determined by the temperature of the heating plates 41A and 41B, regardless of the type of polymerization initiator. There was a tendency to increase when the value was increased, and then to decrease after showing the maximum value. Among them, according to Examples 1-2 to 1-4, 1-7, 1-8, 1-11, and 1-12, the battery capacity is 950 mAh or more, the initial charge / discharge efficiency is 92% or more, and the load characteristic is 85. % Or more and cycle characteristics of 70% or more, and better values were obtained for all of battery capacity, initial charge / discharge efficiency, load characteristics and cycle characteristics. On the other hand, in Examples 1-1, 1-5, 1-6, 1-9, 1-10, 1-13, at least one of battery capacity, initial charge / discharge efficiency, load characteristics, and cycle characteristics is slightly higher. It was low. This is because if the temperature of the heating plates 41A and 41B is too low, a large amount of unreacted monomer remains as shown in Table 1, and if it is too high, a large amount of lithium hexafluorophosphate is decomposed. It is thought to be caused by this. That is, the temperature of the heating plates 41A, 41B is not less than (the 10-hour half-life temperature of the polymerization initiator−8 ° C.) or more (the 10-hour half-life temperature of the polymerization initiator + 50 ° C.) or the lower temperature of 120 ° C. It was found that it was preferable to be within the range. Further, it was found that the battery characteristics can be improved by applying heat and pressure to the assembly 1 by the heating plates 41A and 41B incorporating the heat sources 42A and 42B regardless of the kind of the polymerization initiator. .

(Examples 2-1 to 2-4)
A secondary battery was fabricated in the same manner as in Example 1-3, except that the pressure applied to the assembly 1 was changed as shown in Table 2. Moreover, as Comparative Example 2-1 with respect to Examples 2-1 to 2-4, except that the pressure applied to the assembly 1 was set to 10 MPa, other than the secondary as in Examples 2-1 to 2-4 A battery was produced. For the secondary batteries of Examples 2-1 to 2-4 and Comparative Example 2-1, the battery capacity, load characteristics, low temperature characteristics, cycle characteristics, liquid leakage amount, monomer remaining were the same as in Example 1-3. The rate and the amount of hydrogen fluoride were examined. The results are shown in Table 2 together with the results of Example 1-3. Moreover, the relationship between the pressure of Examples 1-3, 2-1 to 2-4 and Comparative Example 2-1 and the battery capacity and the initial charge / discharge efficiency is shown in FIG. Is shown in FIG.

  As is clear from Table 2, FIG. 10 and FIG. 11, the battery capacity, the initial charge / discharge efficiency, the load characteristics and the cycle characteristics all increase when the pressure applied to the assembly 1 is increased, and then decrease after showing the maximum value. The tendency to become was seen. Among them, according to Examples 1-3, 2-2, and 2-3, the battery capacity is 950 mAh or more, the initial charge / discharge efficiency is 92% or more, the load characteristic is 85% or more, and the cycle characteristic is 70% or more. Better values were obtained for all of capacity, initial charge / discharge efficiency, load characteristics, and cycle characteristics. On the other hand, in Examples 2-1 and 2-4, at least one of battery capacity, initial charge / discharge efficiency, load characteristics, and cycle characteristics was slightly low. In Comparative Example 2-1, the battery capacity, the initial charge / discharge efficiency, and the load characteristics were zero, and the cycle characteristics were very bad. If the pressure is too low, the adhesion between the gel electrolyte and the positive electrode 11, the negative electrode 12 and the separator 13, the adhesion between the positive electrode 11 and the negative electrode 12 and the separator 13, or the positive electrode 11 and the negative electrode 12 via the gel electrolyte. If the adhesiveness between the separator 13 and the separator 13 is too small and too large, a minute short circuit occurs, and if the pressure is 10 MPa or more, the contents of the assembly are crushed. That is, it has been found that the pressure applied to the assembly 1 needs to be less than 10 MPa, and it is more preferable that the pressure be within the range of 0.1 MPa to 3 MPa.

(Examples 3-1 to 3-4)
A secondary battery was fabricated in the same manner as in Example 1-3, except that the heating / pressurizing time was changed as shown in Table 3. For the secondary batteries of Examples 3-1 to 3-4, as in Example 1-3, the battery capacity, load characteristics, low temperature characteristics, cycle characteristics, liquid leakage, monomer residual rate, and hydrogen fluoride content I investigated. The results are shown in Table 3 together with the results of Example 1-3. Moreover, the relationship between the heating / pressurizing time, battery capacity, and initial charge / discharge efficiency of Examples 1-3, 3-1 to 3-4 is shown in FIG. The relationship is shown in FIG.

  As is apparent from Table 3, FIG. 12 and FIG. 13, the battery capacity, the initial charge / discharge efficiency, the load characteristics, and the cycle characteristics all increase when the heating / pressurization time is lengthened, and then show a maximum value and then decrease. The tendency to become was seen. Among them, according to Examples 1-3, 3-2, and 3-3, the battery capacity is 950 mAh or more, the initial charge / discharge efficiency is 92% or more, the load characteristic is 85% or more, and the cycle characteristic is 70% or more. Better values were obtained for all of capacity, initial charge / discharge efficiency, load characteristics, and cycle characteristics. On the other hand, in Examples 3-1 and 3-4, at least one of battery capacity, initial charge / discharge efficiency, load characteristics, and cycle characteristics was slightly low. This is because if the heating / pressurizing time is too short, a large amount of unreacted monomer remains as shown in Table 3, and if it is too long, a large amount of lithium hexafluorophosphate is decomposed. It is thought to be caused. That is, it was found that the heating / pressurizing time is preferably in the range of 1 minute to 10 minutes.

(Examples 4-1 to 4-3)
As Example 4-1, a secondary battery was fabricated in the same manner as in Example 1-3, except that diethyl carbonate (DEC) was used instead of dimethyl carbonate as the solvent. Further, as Example 4-2, the solvent used was 20% by weight of ethylene carbonate, 60% by weight of ethyl methyl carbonate, 15% by weight of dimethyl carbonate, 2.5% by weight of γ-butyrolactone (GBL), and γ-valero. A secondary battery was made in the same manner as Example 1-3, except that a mixture of 2.5% by weight of lactone (GVL) was used. Further, as Example 4-3, the solvent was ethylene carbonate 20% by weight, ethyl methyl carbonate 60% by weight, dipropyl carbonate (DPC) 5% by weight, ethylpropyl carbonate (EPC) 10% by weight, propylene A secondary battery was fabricated in the same manner as in Example 1-3 except that a mixture of 5% by weight of carbonate was used. For the secondary batteries of Examples 4-1 to 4-3, the battery capacity, load characteristics, low temperature characteristics, cycle characteristics, leakage amount, monomer residual ratio, and hydrogen fluoride amount were the same as in Example 1-3. I investigated. The results are shown in Table 4 together with the results of Example 1-3.

  As is apparent from Table 4, according to Examples 4-1 to 4-3, as in Example 1-3, the battery capacity, load characteristics, low temperature characteristics, cycle characteristics, liquid leakage, monomer residual ratio and Good results were obtained for the amount of hydrogen fluoride. That is, it has been found that even if other solvents are used, the battery characteristics can be improved by applying heat and pressure to the assembly 1 by the heating plates 41A and 41B incorporating the heat sources 42A and 42B.

(Examples 5-1 to 5-5)
A secondary battery was fabricated in the same manner as in Example 1-3, except that the weight ratio of the electrolytic solution, the monomer, and the polymerization initiator and the heating / pressurizing time were changed as shown in Table 5. For the secondary batteries of Examples 5-1 to 5-5, as in Example 1-3, the battery capacity, load characteristics, low temperature characteristics, cycle characteristics, liquid leakage, monomer residual rate, and hydrogen fluoride content I investigated. The results are shown in Table 5 together with the results of Example 1-3.

  As is clear from Table 5, both Examples 5-1 and 5-2 were low in battery capacity, initial charge / discharge efficiency, load characteristics, and cycle characteristics as compared with Example 1-3. This is because if the amount of the monomer is too small, the liquid retention property of the gel electrolyte is lowered, and as shown in Table 5, the liquid leakage is increased. If the amount is too large, the ion conductivity of the gel electrolyte is lowered. Conceivable.

  As is clear from Table 5, Example 5-3 also had lower battery capacity, initial charge / discharge efficiency, load characteristics, and cycle characteristics than Example 1-3. This is presumably because the amount of leakage and residual monomer increased as shown in Table 5 due to too little polymerization initiator. On the other hand, Example 5-4 also had lower battery capacity, initial charge / discharge efficiency, load characteristics, and cycle characteristics than Example 1-3. This is thought to be due to the fact that polymerization took time and that, as in the case of heating using an oven, phenomena such as the generation of hydrogen fluoride due to thermal decomposition of the electrolyte salt occurred. Further, in Example 5-5, all of the battery capacity, the initial charge / discharge efficiency, the load characteristics, and the cycle characteristics were lower than those in Example 1-3. This is presumably because the polymerization initiator induced a side reaction.

  That is, it is necessary to optimize the ratio of the electrolytic solution, the monomer, and the polymerization initiator depending on the material used. In this example, the weight ratio of the monomer to the total of the electrolytic solution and the monomer is 4%. It has been found that it is preferable to improve the battery characteristics by setting the polymerization initiator to about% to 6% and the polymerization initiator to about 0.2% to 1%.

(Examples 6-1 to 6-2)
As Example 6-1, except that the thickness of the heating plates 41A and 41B is 1 cm and the heat capacity of the two heating plates 41A and 41B is 345 J / K, that is, 34.5 times the heat capacity of the assembly. Other than that, a secondary battery was fabricated in the same manner as in Example 1-4. Further, as Example 6-2, a secondary battery was fabricated in the same manner as Example 1-4, except that the output of the heat source was 50 W, which was the sum of the two heating plates 41A and 41B. For the secondary batteries of Examples 6-1 and 6-2, as in Example 1-4, the battery capacity, load characteristics, low temperature characteristics, cycle characteristics, liquid leakage, monomer residual rate, and hydrogen fluoride content I investigated. The results are shown in Table 6 together with the results of Example 1-4.

  As is apparent from Table 6, according to Example 1-4, all of the battery capacity, initial charge / discharge efficiency, load characteristics, and cycle characteristics were higher than those of Examples 6-1 and 6-2. As shown in Table 6, in Example 1-4, as compared with Examples 6-1 and 6-2, the amount of leakage and the residual monomer ratio are smaller. It can be considered that a sufficient amount of heat can be supplied, and the polymerization proceeds in comparison with Examples 6-1 and 6-2 even at the same time. That is, if the heat capacity of the heating plates 41A and 41B is set to 40 times or more of the heat capacity of the battery, or the output of the heat sources 42A and 42B is set within the range shown by the equation 1, the battery characteristics. It was found that can be further improved.

(Examples 7-1 to 7-13)
A secondary battery was manufactured by the battery manufacturing method described in the second embodiment. First, the positive electrode 11 and the negative electrode 12 were produced like Example 1-1 (refer FIG. 7; step S111). After that, a monomer solution in which the same monomer as in Example 1-1 was dissolved in dimethyl carbonate as a dilution solvent at a concentration of 3% by weight was prepared, and this monomer solution was applied to the positive electrode 11 and the negative electrode 12 and impregnated. After that (see FIG. 7; step S212), it was dried. Subsequently, the positive electrode 11 and the negative electrode 12 impregnated with the monomer solution are wound through the same separator 13 as in Example 1-1 to obtain a wound electrode body (see FIG. 7; step S213), and then the exterior. It was stored inside the member 20 (see FIG. 7; step S214).

  Next, an electrolyte composition having the same composition as that of Example 1-1 except that no monomer was contained was prepared, and this electrolyte composition was poured into the exterior member 20 (see FIG. 7; step S215), and the exterior The opening of the member 20 was heat-sealed and sealed (see FIG. 7; step S216) to form an assembly with a heat capacity of 10 J / K (see FIG. 7; step S210). Thereafter, heat and pressure were applied to the assembly using the manufacturing apparatus shown in FIG. 6 as in Example 1-1 (see FIG. 7; step S220). At that time, the temperature of the heating plates 41A and 41B, the pressure applied to the assembly, and the heating / pressurizing time were changed as shown in Table 7 in Examples 7-1 to 7-13. Through the above steps, secondary batteries of Examples 7-1 to 7-13 were obtained.

  Moreover, as Comparative Examples 7-1 to 7-3 with respect to Examples 7-1 to 7-13, the thickness of the assembly having a square surface with a side of 150 mm is the same as Comparative Examples 1-2 to 1-4. Except that it was sandwiched between 6 mm stainless steel plates, applied with a pressure of 2 MPa with a spring, and stored in a 70 ° C. oven for the time shown in Table 7, it was the same as in Examples 7-1 to 7-13. A secondary battery was manufactured. Further, as Comparative Example 7-4 with respect to Examples 7-1 to 7-13, the secondary battery was the same as Example 7-1 to 7-13 except that a pressure of 10 MPa was applied to the assembly. Was made.

  Regarding the secondary batteries of Examples 7-1 to 7-13 and Comparative Examples 7-1 to 7-4, the battery capacity, the load characteristics, the low temperature characteristics, the cycle characteristics, and the liquid leakage were the same as in Example 1-1. The amount, monomer residual rate and hydrogen fluoride amount were examined. The results are shown in Table 7.

  As is clear from Table 7, the same tendency as in Examples using the composition for electrolyte containing the monomer was observed. That is, while the monomer is applied to the positive electrode 11 and the negative electrode 12 and the electrolyte composition includes an electrolytic solution and a polymerization initiator and does not include the monomer, the heating including the heat sources 42A and 42B is used. It has been found that the battery characteristics can be improved by applying heat and pressure to the assembly by the plates 41A and 41B.

  In the above-described examples, the electrolyte solution, the monomer, and the polymerization initiator have been described with specific examples. However, similar results can be obtained using other materials.

  Although the present invention has been described with reference to the embodiments and examples, the present invention is not limited to the embodiments and examples, and various modifications can be made. For example, in the above-described embodiments and examples, the case where heating wires are used as the heat sources 42A and 42B has been described, but the heat sources 42A and 42B are not limited to heating wires.

  In the above embodiment and examples, the case where the positive electrode active material layer 11B and the negative electrode active material layer 12B are formed using the particulate positive electrode active material and the particulate negative electrode active material has been described. The positive electrode active material layer 11B and the negative electrode active material layer 12B may be formed. Moreover, about the negative electrode 12, you may use plate-shaped or foil-shaped lithium metal.

  Further, in the above embodiments and examples, the wound type secondary battery has been described, but the present invention is similarly applied to a battery having another structure such as a single layer type, a stacked type, or a zigzag folded type. be able to. In addition, the present invention can be applied not only to secondary batteries but also to primary batteries.

  Furthermore, in the above embodiments and examples, a secondary battery using lithium as an electrode reactive species has been described, but the present invention can be widely applied to batteries using a gel electrolyte formed by polymerizing monomers. .

It is a flowchart showing the manufacturing method of the battery which concerns on the 1st Embodiment of this invention. It is sectional drawing showing 1 process of the manufacturing method of the battery which concerns on the 1st Embodiment of this invention. FIG. 3 is a cross-sectional view illustrating a process following FIG. 2. FIG. 4 is an exploded perspective view illustrating a process following FIG. 3. FIG. 5 is an exploded perspective view illustrating a process following FIG. 4. It is sectional drawing showing schematic structure of the manufacturing apparatus used in the process following FIG. It is a flowchart showing the manufacturing method of the battery which concerns on the 2nd Embodiment of this invention. It is a characteristic view showing the relationship between the temperature of the heating plate of Examples 1-1 to 1-13 of the present invention, battery capacity, and initial charge / discharge efficiency. It is a characteristic view showing the relationship between the temperature of the heating plate of Examples 1-1 to 1-13 of the present invention, load characteristics, and cycle characteristics. It is a characteristic view showing the relationship between the pressure of Examples 1-3, 2-1 to 2-4 and Comparative Example 2-1 of the present invention, battery capacity, and initial charge / discharge efficiency. It is a characteristic view showing the relationship between the pressure of Examples 1-3, 2-1 to 2-4 and Comparative Example 2-1 of the present invention, load characteristics, and cycle characteristics. It is a characteristic view showing the relationship between the heating and pressurizing time, battery capacity, and initial charge / discharge efficiency of Examples 1-3 and 3-1 to 3-4 of the present invention. It is a characteristic view showing the relationship between the heating and pressurizing time, load characteristics and cycle characteristics of Examples 1-3 and 3-1 to 3-4 of the present invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Assembly, 10 ... Winding electrode body, 11 ... Positive electrode, 11A ... Positive electrode collector, 11B ... Positive electrode active material layer, 11C ... Positive electrode lead, 12 ... Negative electrode, 12A ... Negative electrode collector, 12B ... Negative electrode active Material layer, 12C ... negative electrode lead, 13 ... separator, 14 ... protective tape, 20 ... exterior member, 21 ... adhesion film, 40 ... manufacturing apparatus, 41A, 41B ... heating plate, 42A, 42B ... heat source, 43 ... pressing member.

Claims (8)

Forming an assembly comprising an electrolyte, a monomer, and a polymerization initiator together with a positive electrode and a negative electrode;
Applying a heat and a pressure of less than 10 MPa to the assembly by a heating plate incorporating a heat source. The battery manufacturing method according to claim 1, wherein a heat capacity of the heating plate is 40 times or more a heat capacity of the assembly. The method of manufacturing a battery according to claim 1, wherein the output of the heat source is within a range indicated by Formula 1.
(Equation 1)
Y (W) ≧ X (J / K) × 100 (K) ÷ 15 (seconds)
(In the formula, Y represents the output of the heat source, and X represents the heat capacity of the assembly.) The temperature of the heating plate is (10-hour half-life temperature of the polymerization initiator—8 ° C.) or more (10-hour half-life temperature of the polymerization initiator + 50 ° C.) or within the range of the lower temperature of 120 ° C. The method for producing a battery according to claim 1, wherein the pressure is in the range of 0.1 MPa to 3 MPa, and the time for applying heat and pressure to the assembly is 1 minute or more and 10 minutes or less. The battery manufacturing method according to claim 1, wherein the negative electrode includes at least one of a negative electrode material capable of inserting and releasing lithium, a lithium alloy, and metallic lithium. A battery manufacturing apparatus for heating and pressurizing an assembly comprising an electrolyte, a monomer, and a polymerization initiator together with a positive electrode and a negative electrode,
An apparatus for manufacturing a battery, comprising a heating plate that incorporates a heat source and applies heat and a pressure of less than 10 MPa to the assembly. The battery manufacturing apparatus according to claim 6, wherein a heat capacity of the heating plate is 40 times or more a heat capacity of the assembly. The battery manufacturing apparatus according to claim 6, wherein an output of the heat source is within a range represented by Formula 2.
(Equation 2)
Y (W) ≧ X (J / K) × 100 (K) ÷ 15 (seconds)
(In the formula, Y represents the output of the heat source, and X represents the heat capacity of the assembly.)

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