JP2012151036A - Laminated battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated battery capable of inhibiting the shrinkage of an electrode even if the temperature increases.SOLUTION: A laminated battery comprises a laminate 1. The laminate 1 contains a positive electrode 11, a negative electrode 12, and separators 13 and 14. The separator 13 is made of nonwoven fabric and shaped into a pocket. The separator 14 is made of a porous film. The positive electrode 11 is contained in the separator 13, and the separator 13 is sandwiched in the separator 14. The laminate 1 has a structure alternately laminated with the separator 13 and the positive electrode 11 sandwiched in the separator 14, and the negative electrode 12.

Description

  The present invention relates to a laminated battery.

  Conventionally, a laminated battery having a structure in which a positive electrode is placed in a bag-like separator is known (Patent Document 1).

  In this laminated battery, the positive electrode is positioned in the bag-shaped separator. In this case, the positive electrode is positioned in the bag-like separator by the following method. At least one fusion part is formed in each of at least two sides adjacent to each other of the bag-shaped separator, and the positive electrode is positioned by holding the positive electrode in the fusion part. Further, except for the portion through which the positive electrode lead passes, the four sides are partially fused or continuously fused, and the positive electrode is positioned by holding the positive electrode at the fused portion.

Japanese Patent Laid-Open No. 07-302616

  However, in the laminated battery disclosed in Patent Document 1, when the bag-like separator is made of a porous film and the porous film is, for example, polyethylene, the bag-like separator shrinks when the temperature exceeds 100 ° C. For this reason, there is a problem that the electrode accommodated in the bag-shaped separator also shrinks.

  Accordingly, the present invention has been made to solve such a problem, and an object of the present invention is to provide a laminated battery capable of suppressing shrinkage of an electrode even when the temperature rises.

  According to the embodiment of the present invention, the laminated battery includes first and second electrodes and first and second separators. The second electrode has a different polarity from the first electrode. The first separator is formed into a bag shape, houses the first electrode, and has a heat resistant temperature equal to or higher than the first temperature. The second separator is disposed between the first electrode and the second electrode, and has a second temperature whose melting point is lower than the first temperature.

  In the laminated battery according to the embodiment of the present invention, when the battery temperature rises, the second separator shrinks and the first separator does not shrink. As a result, the first electrode housed in the first separator does not shrink.

  Therefore, shrinkage of the electrode can be suppressed even when the temperature rises.

  Moreover, even if the temperature rises, the first electrode remains housed in the first separator. As a result, the first electrode is not in contact with the second electrode.

  Therefore, a short circuit due to a temperature rise can be prevented.

FIG. 1 is a plan view of a laminated battery according to an embodiment of the present invention. 2 is a cross-sectional view of the laminated battery taken along line II-II shown in FIG. FIG. 3 is a cross-sectional view showing the configuration of the laminate shown in FIG. FIG. 4 is a perspective view of the positive electrode and the separator shown in FIG. FIG. 5 is a perspective view of the positive electrode and two separators shown in FIG. FIG. 6 is a process diagram showing a method of manufacturing the laminated battery 10 shown in FIGS. 1 and 2. FIG. 7 is a configuration diagram of another laminated body. FIG. 8 is a configuration diagram of still another laminated body.

  Embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

  FIG. 1 is a plan view of a laminated battery according to an embodiment of the present invention. 2 is a cross-sectional view of the laminated battery taken along line II-II shown in FIG.

  Referring to FIGS. 1 and 2, a laminated battery 10 according to an embodiment of the present invention includes a laminate 1, a positive electrode tab 2, a negative electrode tab 3, and a laminate film 4.

  The laminate 1 is laminated with a laminate film 4 (= 4a, 4b). One end of the positive electrode tab 2 is connected to the positive electrode of the multilayer body 1 by a lead body 5. Further, the other end side of the positive electrode tab 2 is drawn to the outside through the laminate film 4. A part of the positive electrode tab 2 is laminated with a laminate film 4.

  One end of the negative electrode tab 3 is connected to the negative electrode of the multilayer body 1 by a lead body (not shown). Further, the other end side of the negative electrode tab 3 is drawn to the outside through the laminate film 4. A part of the negative electrode tab 3 is laminated with a laminate film 4.

  The laminate film 4 has a substantially rectangular planar shape, and laminates the laminate 1, a part of the positive electrode tab 2, and a part of the negative electrode tab 3. And the laminate film 4 has the sealed part 41 sealed at the edge.

  In FIG. 1, the positive electrode tab 2 and the negative electrode tab 3 are drawn out from the same side of the laminate film 4. However, in the embodiment of the present invention, the positive electrode tab 2 and the negative electrode tab 3 are not limited thereto. May be drawn from different sides of the laminate film 4.

  FIG. 3 is a cross-sectional view showing the configuration of the laminate 1 shown in FIG. Referring to FIG. 3, laminate 1 includes a positive electrode 11, a negative electrode 12, and separators 13 and 14.

  The positive electrode 11 has a size smaller than that of the negative electrode 12 in the in-plane direction DR1 of the laminated battery 10. The positive electrode 11 and the negative electrode 12 are arranged so that both ends of the negative electrode 12 are located outside the both ends of the positive electrode 11 in the in-plane direction DR1.

  The separator 13 is formed in a bag shape and houses the positive electrode 11. The separator 14 is disposed between the negative electrode 12 and the separator 13 so as to sandwich the separator 13.

  The positive electrode 11 has, for example, a structure in which a layer (positive electrode mixture layer) made of a positive electrode mixture containing a positive electrode active material, a conductive additive, a binder, and the like is formed on one side or both sides of a current collector.

For example, when the laminated battery 10 is a lithium ion secondary battery, the positive electrode active material is made of an active material that can occlude and release lithium ions. Such a positive electrode active material is, for example, a lithium-containing transition metal having a layered structure represented by Li _{1 + x} MO ₂ (−0.1 <x <0.1, M: Co, Ni, Mn, Al, Mg, etc.) Oxides, LiMn ₂ O ₄ , lithium manganese oxide having a spinel structure in which some of the elements are replaced with other elements, and olivine type compounds represented by LiMPO ₄ (M: Co, Ni, Mn, Fe, etc.) Consisting of either.

The lithium-containing transition metal oxide having a layered structure is, for example, LiCoO ₂ , LiNi _1-x Co _xy Al _y O ₂ (0.1 ≦ x ≦ 0.3, 0.01 ≦ y ≦ 0.2 And an oxide containing at least Co, Ni and Mn (LiMn _1/3 Ni _1/3 Co _1/3 O ₂ , LiMn _5/12 Ni _5/12 Co _1/6 O ₂ , LiNi _3/5 Mn _{1 / 5} Co _1/5 O ₂ ).

  The current collector of the positive electrode 11 is made of, for example, an aluminum foil or an aluminum alloy foil. The thickness of the current collector varies depending on the size and capacity of the battery, but is, for example, 0.01 to 0.02 mm.

  The positive electrode 11 is produced by the following method. A positive electrode mixture containing a positive electrode active material, a conductive additive such as graphite, acetylene black, carbon black, and fibrous carbon, and a binder such as polyvinylidene fluoride (PVDF) is mixed with N-methyl-2-pyrrolidone (NMP). ) Or the like to prepare a paste-like or slurry-like composition uniformly dispersed (the binder may be dissolved in the solvent). And this composition is apply | coated on the electrical power collector of the positive electrode 11, it dries, and the thickness of a positive mix layer is adjusted by press processing as needed. Thereby, the positive electrode 11 is produced.

  In the embodiment of the present invention, the positive electrode 11 may be produced using a method other than the method described above.

  The thickness of the positive electrode mixture layer in the positive electrode 11 is preferably 30 to 100 μm per side. Moreover, it is preferable that content of each structural component in a positive mix layer shall be positive electrode active material: 90-98 mass%, conductive support agent: 1-5 mass%, and binder: 1-5 mass%.

  The positive electrode tab 2 is preferably made of aluminum or an aluminum alloy from the viewpoint of ease of connection with the equipment used.

  And the thickness of the positive electrode tab 2 is 50-300 micrometers. That is, by setting the thickness of the positive electrode tab 2 to 50 μm or more, it is possible to prevent the positive electrode tab 2 from being cut during welding of the positive electrode tab 2 and to prevent the positive electrode tab 2 from being broken by pulling and bending. it can. Moreover, by setting the thickness of the positive electrode tab 2 to 300 μm or less, it is possible to prevent a gap in the thickness direction from being generated in the heat seal portion of the laminate film 4.

  In addition, in order to increase the adhesive strength between the positive electrode tab 2 and the laminate film 4, a resin adhesive layer (for example, the laminate film 4) is previously placed on the positive electrode tab 2 where it is planned to be located at the heat seal portion. You may provide the contact bonding layer comprised by resin of the same kind as resin which comprises the heat sealing resin layer which the metal laminate film to comprise has.

  Examples of the method of connecting the current collector in the positive electrode 11 or the aluminum lead body 5 connected to the current collector and the positive electrode tab 2 include resistance welding, ultrasonic welding, laser welding, caulking, and conductive bonding. Various methods such as a method using an agent can be employed. Of these, ultrasonic welding is particularly suitable.

  For example, when the laminated battery 10 is a lithium ion secondary battery, the negative electrode 12 includes an active material that can occlude and release lithium ions. Such negative electrode active materials occlude and release lithium ions such as graphite, pyrolytic carbons, cokes, glassy carbons, fired organic polymer compounds, mesocarbon microbeads (MCMB), and carbon fibers. It consists of one or a mixture of two or more possible carbon-based materials.

In addition, the negative electrode active material may be an element such as Si, Sn, Ge, Bi, Sb, or In, an alloy of Si, Sn, Ge, Bi, Sb, or In, a lithium metal such as a lithium-containing nitride, or a lithium oxide. It consists of a compound (LiTi ₃ O ₁₂ or the like) that can be charged and discharged at a low voltage, lithium metal, and a lithium / aluminum alloy.

  These negative electrode active materials include a conductive additive (made of the same material as the positive electrode conductive additive), a binder (a binder of PVDF, rubber binder such as styrene butadiene rubber (SBR) and carboxymethyl cellulose (CMC), etc. ) Is added as appropriate to the negative electrode mixture, and the current collector is a finished product (negative electrode mixture layer) using the current collector as a core material, or the above-described various alloys or lithium metal foils. A material laminated on the surface is used as the negative electrode 12.

  And the negative electrode 12 is produced by the following method. A paste in which a negative electrode mixture containing the above-described negative electrode active material, a binder, and, if necessary, a conductive additive such as graphite, acetylene black, and carbon black is uniformly dispersed using a solvent such as NMP. Alternatively, a slurry-like composition is prepared (the binder may be dissolved in a solvent). And this composition is apply | coated on a negative electrode electrical power collector, it dries, and the thickness or density of a negative mix layer is adjusted by press processing as needed. Thereby, the negative electrode 12 is produced.

  In the embodiment of the present invention, negative electrode 12 may be fabricated using a method other than the method described above.

  As the current collector of the negative electrode 12, a copper foil is suitable. And although the thickness of an electrical power collector is based on the magnitude | size or capacity | capacitance of a battery, it is preferable that it is 0.005-0.02 mm, for example.

  The thickness of the negative electrode mixture layer in the negative electrode 12 is preferably 30 to 100 μm per side. Moreover, it is preferable that content of each structural component in a negative mix layer is 90-98 mass% of negative electrode active materials, and 1-5 mass% of binders. Moreover, when using a conductive support agent for a negative electrode, it is preferable that content of the conductive support agent in a negative mix layer is 1-5 mass%.

  The negative electrode tab 3 is made of a metal foil or ribbon such as nickel, nickel-plated copper, and nickel-copper clad. Moreover, it is preferable that the thickness of the negative electrode tab 3 is 50-300 micrometers similarly to the positive electrode tab 2. FIG.

  That is, by setting the thickness of the negative electrode tab 3 to 50 μm or more, it is possible to prevent the negative electrode tab 3 from being cut during welding of the negative electrode tab 3 and to prevent the negative electrode tab 3 from being torn by pulling and bending. it can. In addition, by setting the thickness of the negative electrode tab 3 to 300 μm or less, it is possible to prevent a gap in the thickness direction from being generated in the heat seal portion of the laminate film 4.

  In addition, in order to increase the adhesive strength between the negative electrode tab 3 and the laminate film 4, a resin adhesive layer (for example, the laminate film 4) is previously placed on the portion where the negative electrode tab 3 is supposed to be located at the heat seal portion. You may provide the contact bonding layer comprised by resin of the same kind as resin which comprises the heat sealing resin layer which the metal laminate film to comprise has.

  The connection between the current collector in the negative electrode 12 or the copper lead connected to the current collector and the negative electrode tab 3 is, for example, resistance welding, ultrasonic welding, laser welding, caulking, and a method using a conductive adhesive, etc. This is done by various methods. Among these methods, ultrasonic welding is particularly suitable.

  The separator 13 is made of a heat resistant porous substrate. The heat resistant porous substrate is made of a fibrous material having a heat resistant temperature of 150 ° C. or higher, for example. The fibrous material is formed of at least one material selected from the group consisting of cellulose and its modified products, polyolefin, polyethylene terephthalate, polybutylene terephthalate, polypropylene, polyester, polyacrylonitrile, aramid, polyamideimide, and polyimide. More specifically, it is made of a nonwoven fabric made of the above material.

  “Heat resistance” of the porous substrate means that a substantial dimensional change due to softening or the like does not occur, and the change in the length of the object, that is, the shrinkage of the porous substrate with respect to the length at room temperature. The heat resistance is evaluated based on whether or not the upper limit temperature (heat resistance temperature) at which the ratio (shrinkage ratio) can be maintained at 5% or less is sufficiently higher than the shutdown temperature of the separator. In order to increase the safety of the laminated battery after shutdown, it is desirable that the porous substrate has a heat resistance higher by 20 ° C. than the shutdown temperature. More specifically, the heat resistance temperature of the porous substrate is 150 ° C. It is preferable that the temperature is higher than or equal to ° C, and more preferably higher than or equal to 180 ° C.

  Thus, although the separator 13 has a heat resistant temperature of 150 ° C. or higher, the separator 13 having a heat resistant temperature of 150 ° C. or higher refers to a separator having a shrinkage rate at 150 ° C. of 5% or lower.

And shrinkage | contraction rate is calculated | required as follows. The separator is cut out to 10 cm × 10 cm, stored in a commercially available envelope, and left in a constant temperature bath set at 150 ° C., for example. And each separator is taken out from a thermostat, the dimension x is measured, and the shrinkage rate is calculated by the following formula using the measured dimension x and the dimension before being left in the thermostat.
Shrinkage rate (%) = 100 × (10−x) / 10 (1)
The separator 14 is made of a porous film. The porous film is made of a thermoplastic resin having a melting point of 80 to 140 ° C., for example, in order to provide the separator 14 with a shutdown function for closing the micropores at a certain temperature or higher (100 to 140 ° C.) and increasing the resistance. . More specifically, the porous film is made of an olefin polymer such as polypropylene and polyethylene having organic solvent resistance and hydrophobicity.

  Each of the separators 13 and 14 preferably has a thickness of 10 to 50 μm. Further, the aperture ratio of the separator 14 is smaller than the aperture ratio of the separator 13.

When the laminate battery 10 is a lithium ion secondary battery, the electrolyte used for the laminate battery 10 is, for example, a solution (non-aqueous solution) in which a solute such as LiPF ₆ or LiBF ₄ is dissolved in a high dielectric constant solvent or an organic solvent. Electrolyte). The high dielectric constant solvent is composed of any of ethylene carbonate (EC), propylene carbonate (PC), and γ-butyrolactone (BL). The organic solvent is composed of a low-viscosity solvent such as linear dimethyl carbonate (DMC), diethyl carbonate (DEC), and methyl ethyl carbonate (EMC).

  In addition, it is preferable to use the mixed solvent of the high dielectric constant solvent mentioned above and a low-viscosity solvent as electrolyte solution solvent. Alternatively, PVDF, a rubber-based material, an alicyclic epoxy, a material having an oxetane-based three-dimensional crosslinked structure, and the like may be mixed and solidified into the above-described solution to form a polymer electrolyte.

  4 is a perspective view of the positive electrode 11 and the separator 13 shown in FIG. Referring to FIG. 4, separator 13 has a substantially rectangular planar shape, and has welded portion 131 at the edge except for the open end. As a result, the separator 13 is formed into a bag shape. And the positive electrode 11 is accommodated in the separator 13 shape | molded by the bag shape.

  FIG. 5 is a perspective view of the positive electrode 11 and the two separators 13 and 14 shown in FIG. With reference to FIG. 5, the separator 14 is arrange | positioned so that the separator 13 shape | molded by the bag shape may be inserted | pinched.

  And the edge part of the separator 14 is not welded. As a result, the separator 14 does not cover both end portions of the separator 13 in the width direction DR2 of the laminated battery 10.

  As described above, the separator 13 has a heat resistant temperature of 150 ° C. or higher, and the separator 14 has a melting point of 80 ° C. to 140 ° C.

  As a result, when the temperature of the laminated battery 10 exceeds, for example, 100 ° C., the separator 14 shrinks, but the separator 13 does not shrink. And even if the separator 14 contracts, since the edge part of the separator 14 is not welded, the positive electrode 11 and the separator 13 do not contract.

  Therefore, the shrinkage of the positive electrode 11 (electrode) can be suppressed even when the temperature of the laminated battery 10 rises.

  Further, even if the separator 14 is contracted, the positive electrode 11 remains housed in the separator 13. As a result, even if the separator 14 is contracted, the positive electrode 11 does not contact the negative electrode 12.

  Therefore, even if the temperature of the laminated battery 10 rises, a short circuit can be prevented.

  Further, if gas is generated during overcharging of the laminate battery 10, the generated gas enters the gap between the separator 13 and the separator 14, and the distance between the positive electrode 11 and the negative electrode 12 increases. Therefore, a short circuit can be prevented. As a result, the safety of the laminated battery 10 can be improved.

  When the separators 13 and 14 are made of the same material, the separator 13 made of a nonwoven fabric is less likely to shrink than the separator 14 made of a porous film even if the temperature is the same. This is because, since the porous film is generally manufactured using a stretching process, when the temperature of the separator 14 increases, the separator 14 is easily shrunk due to residual stress during the stretching process. .

  Thus, when it consists of the same material, even if temperature is the same, the nonwoven fabric has the characteristic that it is hard to shrink | contract than a porous film.

  FIG. 6 is a process diagram showing a method of manufacturing the laminated battery 10 shown in FIGS. 1 and 2. Referring to FIG. 6, when the production of laminated battery 10 is started, positive electrode 11 and negative electrode 12 are produced by the method described above (step S1).

  And the separator 13 shape | molded by the bag shape is produced (step S2). More specifically, the nonwoven fabric used as the material of the separator 13 is cut out, two rectangular nonwoven fabrics are produced, the two nonwoven fabrics are overlapped, and the edges are welded except for the side that becomes the opening end. Thereby, the separator 13 formed into a bag shape is produced.

  Thereafter, the positive electrode 11 is housed in the separator 13 formed into a bag shape (step S3). And the separator 13 in which the positive electrode 11 was accommodated is pinched | interposed with the separator 14 of a porous film (step S4).

  Subsequently, the separator 13 and the positive electrode 11 sandwiched between the separators 14 of the porous film and the negative electrode 12 are alternately laminated to produce the laminate 1 (step S5).

  Then, the positive electrode tab 2 is connected to the positive electrode 11 by the lead body 5, and the negative electrode tab 3 is connected to the negative electrode 12 by the lead body (step S6).

  Then, the laminated body 1 is accommodated in the laminate film 4, and sides other than the one side into which the electrolytic solution is injected are heat-sealed (step S7).

  If it does so, electrolyte solution will be inject | poured from the side which is not heat-sealed (step S8), and the side which inject | poured electrolyte solution will be heat-sealed (step S9). Thereby, the laminated battery 10 is completed.

  FIG. 7 is a configuration diagram of another laminated body. Laminated battery 10 may include a laminate 1A shown in FIG.

  Referring to FIG. 7, laminated body 1A is the same as laminated body 1 except that separator 14 of laminated body 1 shown in FIG.

  The separator 140 is made of the same material as the separator 14. And the separator 140 is arrange | positioned between the negative electrode 12 and the separator 13, without pinching the separator 13 in which the positive electrode 11 was accommodated.

  When the laminated battery 10 includes the laminated body 1A, when the temperature of the laminated battery 10 exceeds, for example, 100 ° C., the separator 140 contracts, but the separator 13 does not contract. And since the separator 140 is only arrange | positioned between the negative electrode 12 and the separator 13, even if the separator 140 shrinks, the positive electrode 11 and the separator 13 do not shrink.

  Therefore, even when the laminated battery 10 includes the laminate 1A, shrinkage of the positive electrode 11 (electrode) due to the temperature rise of the laminated battery 10 can be suppressed.

  Further, even when the separator 140 is contracted, the positive electrode 11 remains housed in the separator 13. As a result, even if the separator 140 contracts, the positive electrode 11 does not contact the negative electrode 12.

  Therefore, even when the laminated battery 10 includes the laminate 1A, a short circuit due to the temperature rise of the laminated battery 10 can be prevented.

  In the laminate 1, the positive electrode 11 may be sandwiched between the separators 14, and the positive electrode 11 sandwiched between the separators 14 may be stored in the separator 13. That is, the separator 14 may be disposed between the positive electrode 11 and the separator 13.

  Even in this case, shrinkage of the positive electrode 11 due to shrinkage of the separator 14 can be suppressed. Moreover, the short circuit by the shrinkage | contraction of the separator 14 can be prevented.

  In the laminate 1A, the separator 140 may be disposed between the positive electrode 11 and the separator 13. Even in this case, shrinkage of the positive electrode 11 due to shrinkage of the separator 140 can be suppressed. Further, a short circuit due to the shrinkage of the separator 140 can be prevented.

  Furthermore, in each of the laminates 1 and 1A, the negative electrode 12 may be housed in a bag-shaped separator 13 instead of the positive electrode 11. In this case, shrinkage of the negative electrode 12 due to shrinkage of the separator 14 (or separator 140) can be suppressed, and a short circuit due to shrinkage of the separator 14 (or separator 140) can be prevented.

  FIG. 8 is a configuration diagram of still another laminated body. Laminated battery 10 may include a laminate 1B shown in FIG.

  With reference to FIG. 8, a laminated body 1 </ b> B is obtained by adding a separator 130 to the laminated body 1 shown in FIG. 3, and the rest is the same as the laminated body 1.

  The separator 130 is made of the same material as the separator 13 and is formed into a bag shape in the same manner as the separator 13. The separator 130 stores the negative electrode 12.

  When the laminated battery 10 includes the laminated body 1B, for example, when the temperature of the laminated battery 10 exceeds 100 ° C., the separator 14 contracts, but the separators 13 and 130 do not contract. Even if the separator 14 is contracted, the edge of the separator 14 is not welded, so that the positive electrode 11, the negative electrode 12, and the separators 13 and 130 are not contracted.

  Therefore, even when the laminated battery 10 includes the laminate 1B, shrinkage of the positive electrode 11 and the negative electrode 12 (electrode) due to the temperature rise of the laminated battery 10 can be suppressed.

  Further, even when the separator 14 is contracted, the positive electrode 11 remains housed in the separator 13, and the negative electrode 12 remains housed in the separator 130. As a result, even if the separator 14 is contracted, the positive electrode 11 does not contact the negative electrode 12.

  Therefore, even when the laminated battery 10 includes the laminated body 1B, a short circuit due to the temperature rise of the laminated battery 10 can be prevented.

  Further, if gas is generated during overcharging of the laminate battery 10, the generated gas enters the gap between the separator 13 and the separator 14, and the distance between the positive electrode 11 and the negative electrode 12 increases. Therefore, the safety of the laminated battery 10 can be improved even when the laminated battery 10 includes the laminate 1B.

  In the above, the positive electrode 11 is stored in the bag-shaped separator 13, the negative electrode 12 is stored in the bag-shaped separator 13, and the positive electrode 11 and the negative electrode 12 are each formed in a bag shape. It has been described that the separators 13 and 130 are accommodated.

  Further, it has been described that the separator 14 made of a porous film sandwiches the separator 13 and that the separator 140 made of a porous film is disposed between the negative electrode 12 and the separator 13 (positive electrode 11).

  Therefore, in the laminated battery according to the embodiment of the present invention, at least one of the positive electrode 11 and the negative electrode 12 is accommodated in the separators 13 and 130 made of a nonwoven fabric formed into a bag shape, and the separator made of a porous film is the positive electrode. What is necessary is just to arrange | position between 11 and the negative electrode 12.

  With such a configuration, even when the temperature of the laminated battery rises to, for example, 100 ° C. or more and the separator made of the porous film shrinks, the separator formed into a bag shape does not shrink into a bag shape. This is because shrinkage of the electrode housed in the molded separator can be suppressed. Moreover, it is because the short circuit by the shrinkage | contraction of the separator which consists of porous films can be prevented.

  In the above description, the separators 13 and 130 are made of a nonwoven fabric having a heat resistant temperature of 150 ° C. or higher, and the separators 14 and 140 are made of a porous film made of a thermoplastic resin having a melting point of 80 to 140 ° C. However, in the embodiment of the present invention, not limited to this, the separators 13 and 130 are made of a separator having a heat resistance temperature equal to or higher than the first temperature, and the separators 14 and 140 have melting points higher than the first temperature. What is necessary is just to consist of a separator which is low 2nd temperature.

  With such a configuration, even when the temperature of the laminated battery rises to, for example, 100 ° C. or more and the separators 14 and 140 are contracted, the separators 13 and 130 formed into a bag shape are not contracted, but are formed into a bag shape. This is because shrinkage of the electrodes accommodated in the separators 13 and 130 formed in the above can be suppressed. Moreover, it is because the short circuit by the shrinkage | contraction of the separators 14 and 140 can be prevented.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and is intended to include meanings equivalent to the scope of claims for patent and all modifications within the scope.

  The present invention is applied to a laminate type battery and an electronic device including the same.

  1, 1A, 1B Laminated body, 2 Positive electrode tab, 3 Negative electrode tab, 4, 4a, 4b Laminated film, 5 Lead body, 10 Laminated battery, 11 Positive electrode, 12 Negative electrode, 13, 14, 130, 140 Separator, 41 Seal Part, 131 welding part.

Claims (4)

A first electrode;
A second electrode having a polarity different from that of the first electrode;
A first separator that is molded into a bag shape, houses the first electrode, and has a heat-resistant temperature equal to or higher than the first temperature;
A laminated battery comprising: a second separator disposed between the first electrode and the second electrode and having a second temperature lower than the first temperature and having a melting point lower than the first temperature. The first separator is made of a nonwoven fabric,
The laminated battery according to claim 1, wherein the second separator is a porous film made of a thermoplastic resin. The first electrode is a positive electrode;
The laminated battery according to claim 1 or 2, wherein the second electrode is a negative electrode.   4. The laminated battery according to claim 1, wherein the second separator sandwiches the first separator and has no edge welded thereto. 5.

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