JP2012155897A - Laminate battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminate battery which can capture the powder scattering from the inside of a battery entirely even when one peripheral part of the laminate battery cleaves entirely.SOLUTION: In a thin film laminate battery (1) where a power generation element (2) is sealed hermetically with a rectangular laminate film (3), and a gas emission valve (20) is provided in one peripheral parts (16-19) of the laminate film, a powder capturing mechanism (21) for capturing powder scattering from the inside of the battery (1) when the temperature is abnormal is provided between the power generation element (2) and the gas emission valve (20) until it reaches, respectively, two peripheral parts (18, 19) of the laminate film orthogonal to one peripheral part (17) of the laminate film having the gas emission valve (20).

Description

  The present invention relates to a laminate type battery, and particularly to a battery having a power generation element sealed with a rectangular laminate film and having a notch portion as a gas release valve at one central position of the periphery of the laminate film.

  In a can-type battery having a safety valve inside the battery lid, there is a battery in which a layer holding a material that adsorbs gas is provided between the battery lid and the safety valve in order to prevent ignition when the temperature is abnormal (see Patent Document 1). ).

JP 7-192775 A

  By the way, when the temperature of the laminate type battery is abnormal, the peripheral edge of the laminate film having a notch is cleaved, and the organic gas derived from the electrolyte generated from the inside of the battery blows out to the outside. It has been found that aluminum powder scatters.

  Therefore, the conventional can-type battery technology is applied to the laminated battery as it is, and the powder that scatters from the inside of the battery to the outside of the battery is captured only around the notch at one central position on the periphery of the laminated film. It is conceivable to provide a powder trapping mechanism.

  However, in a laminate type battery, not only the vicinity of the notch portion at one central position of the peripheral portion of the laminate film but also the entire peripheral portion of the laminate film is cleaved when the temperature is abnormal. This is mainly because the laminate type battery is covered with a battery outer packaging material that is relatively softer than the can type battery, so that the gas is blown out from the inside of the battery, and the cleavage spreads to one whole of the peripheral part of the laminate film. Because. For this reason, if the conventional can-type battery technology is applied to a laminated battery as it is and a powder trapping mechanism is provided only around the notch, it captures all the powder scattered from the inside of the battery to the outside of the battery. It is not possible.

  Therefore, an object of the present invention is to provide a laminate type battery that can capture all the powder scattered from the inside of the battery to the outside of the battery even when one whole of the peripheral edge of the laminate film is cleaved.

The laminate type battery of the present invention has a power generation element in which a positive electrode and a negative electrode are laminated via a separator, and a rectangular laminate film is used as a battery exterior material to heat all or part of the four laminate film peripheral portions. The power generation element is sealed by bonding by fusion, and when the pressure inside the battery rises to one of the peripheral parts of the laminate film to be bonded by heat fusion, it is cleaved to release the gas inside the battery. The premise is a thin laminated battery having a gas release valve. And, when one of the laminate film peripheral portions having the gas release valve is cleaved and the temperature is abnormal when the powder scatters from the inside of the battery, a powder capturing mechanism for capturing the powder scattered from the inside of the battery, and the power generation element It is provided until it reaches each of the two laminated film peripheral parts which are located between the said gas release valves and orthogonal to one of the laminated film peripheral parts which have the said gas release valve.

  According to the present invention, when the temperature is abnormal, the powder trapping mechanism covers the space formed by one of the peripheral edges of the laminated film that has been cleaved, and the whole of the peripheral edge of the laminate film that has been cleaved by the powder trapping mechanism is outward. Since the scattered powder is captured, it is possible to prevent the powder from scattering from the inside of the laminated battery to the outside even in the case of a laminated battery that is covered with a battery exterior material that is relatively softer than the can-type battery. .

1 is a schematic view of a laminated battery as a premise of the present invention. It is a top view of the laminate type battery of 1st Embodiment of this invention. FIG. 3 is a cross-sectional view along the horizontal plane of the laminate type battery of FIG. 2. FIG. 3 is a partial cross-sectional view of the laminate type battery of FIG. 2 taken along line XX. It is the YY sectional view taken on the line of the laminate type battery of FIG. It is a top view of the present lamination type battery. It is the schematic which looked at the laminated battery of FIG. 6 by Z arrow view. It is the schematic which looked at the laminated battery of FIG. 2 by Z arrow view. It is a top view of the laminate type battery of 2nd Embodiment. FIG. 10 is a cross-sectional view along the horizontal plane of the laminate type battery of FIG. 9. FIG. 10 is a partial cross-sectional view of the laminate type battery of FIG. 9 taken along the line XX. 10 is a cross-sectional view taken along line YY of the laminate type battery of FIG. 9. It is a top view of the filter of a 2nd embodiment. FIG. 10 is a sectional view taken along line XX in FIG. 9. It is a top view of the laminate type battery of 3rd Embodiment. It is sectional drawing along the horizontal surface of the laminate type battery of FIG. It is a top view of the filter of a 3rd embodiment. It is XX sectional drawing of FIG. It is sectional drawing along the horizontal surface of the laminate type battery of 4th Embodiment. It is sectional drawing along the horizontal surface of the laminate type battery of 5th Embodiment. It is sectional drawing along the horizontal surface of the laminate type battery of 6th Embodiment. It is a top view of the laminate type battery of 7th Embodiment. It is sectional drawing along the horizontal surface of the laminate type battery of FIG. It is a schematic perspective view of the filter of 7th Embodiment. It is the XX sectional view taken on the line of FIG. It is the schematic which looked at the lamination type battery of FIG. 22 by Z arrow. It is sectional drawing along the horizontal surface of the laminated battery of 8th Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the dimension ratio of drawing has the location exaggerated on account of description, and the location differs from the actual ratio.

(First embodiment)
First, the lithium ion secondary battery 1 which is a premise of the present invention will be outlined first. FIG. 1 is a schematic view of a lithium ion secondary battery 1. Among these, FIG. 1 (A) is a schematic perspective view of the lithium ion secondary battery 1, and FIG. 1 (B) is a sectional view taken along the line BB of FIG. 1 (A).

  As shown in FIGS. 1 (A) and 1 (B), a lithium ion secondary battery 1 has a substantially square thin plate-like power generation element 2 in which a charge / discharge reaction actually proceeds, inside a laminate film 3 that is a battery exterior material. The structure is sealed. Specifically, a rectangular polymer-metal composite laminate film is used as a battery exterior material to cover both sides of the power generation element 2, and four peripheral portions (peripheral portions) of the coated polymer-metal composite laminate film 3 are heated. The power generation element 2 is housed and sealed by joining by fusion bonding. Here, the polymer-metal composite laminate film generally has a three-layer structure in which a metal film is sandwiched between polymer films (resin films).

  Such a stacked battery 1 is referred to as a “laminated battery” in order to be distinguished from a can battery. A can-type battery is one in which two electrodes are wound and housed in a hard cylindrical metal outer frame like a commercially available AA battery or AA battery. On the other hand, the laminate type battery is a battery in which the power generation element is sealed by joining the peripheral portion (peripheral portion) of the power generation element 2 having a substantially rectangular thin plate shape by heat fusion. Hereinafter, the lithium ion secondary battery 1 is referred to as a “laminated battery”. Alternatively, it is simply called “battery”.

  The power generating element 2 includes a negative electrode 4 in which a negative electrode active material layer 4b is disposed on both sides of a square plate-like negative electrode current collector 4a, a separator 5, and a positive electrode active material layer 6b on both sides of a square plate-like positive electrode current collector 6a. It has the structure which laminated | stacked the positive electrode 6 which has arrange | positioned. Specifically, the negative electrode 4, the separator 5, and the positive electrode 6 are laminated in this order so that one negative electrode active material layer 4 b and the positive electrode active material layer 6 b adjacent to the negative electrode active material layer 4 b face each other with the separator 5 interposed therebetween. Yes. Specifically, the separator 5 has an electrolyte layer integrally formed with the separator 5 by holding the electrolytic solution. Therefore, by disposing the separator 5 between the negative electrode 4 and the positive electrode 6, the electrolyte layer is also substantially disposed between the negative electrode active material layer 4b and the positive electrode active material layer 6b. The separator 5 is mainly formed from a porous thermoplastic resin.

  Thereby, the adjacent negative electrode 4, the separator 5, and the positive electrode 6 comprise the single cell layer 7 (unit cell). Therefore, it can be said that the laminate type battery 1 of the present embodiment has a configuration in which the single battery layers 7 are stacked to be electrically connected in parallel. Further, a seal portion (insulating layer) for insulating between the adjacent negative electrode current collector 4b and the positive electrode current collector 6b may be provided on the outer periphery of the unit cell layer 7. In the outermost layer negative electrode current collector 4 a located in both outermost layers of the power generation element 2, the negative electrode active material layer 4 b is disposed only on one side. 1B, the arrangement of the negative electrode and the positive electrode is reversed so that the outermost positive electrode current collector is positioned in both outermost layers of the power generation element 2, and one side of the outermost positive electrode current collector is arranged. Alternatively, the positive electrode active material layer may be disposed only on the surface.

  The negative current collector 4a and the positive current collector 6a are provided with high voltage tabs 8 and 9 that are electrically connected to the respective electrodes (negative electrode and positive electrode), and are led out of the laminate film 3 so as to be sandwiched between the peripheral edges of the laminate film 3. I am letting. The high voltage tabs 8 and 9 are ultrasonically welded to the negative electrode current collector 4a and the positive electrode current collector 6b of each electrode via a positive electrode terminal lead (not shown) and a negative electrode terminal lead (not shown) as necessary. Or it may be attached by resistance welding.

  As another form of the lithium ion secondary battery, a bipolar electrode in which a positive electrode active material layer is formed on one surface of a current collector and a negative electrode active material layer is formed on the other surface through a separator. A stacked bipolar secondary battery can be mentioned. The battery 1 and the bipolar secondary battery are basically the same except that the electrical connection state (electrode structure) in both batteries is different.

  The laminated battery 1 configured in this manner is stacked and housed inside a metal battery case, and the high voltage tabs of the plurality of stacked stacked batteries 1 are connected in series via the bus bar, thereby providing a predetermined voltage. The battery pack 11 is configured. The bus bar is a component for taking out electricity from the high voltage tab and connecting it to the high voltage cable. Furthermore, an assembled battery having a predetermined voltage is configured by electrically combining a plurality of battery packs 11 via a high-power cable, and this assembled battery is mounted on an electric vehicle or a hybrid vehicle. This completes the overview of the laminated battery 1 which is the premise of the present invention.

  FIG. 2 is a plan view of the laminated battery 1 according to the first embodiment of the present invention. Here, the vertical direction is determined assuming that the battery 1 is arranged horizontally. That is, in FIG. 2, the front side of the paper is vertically upward and the back side of the paper is vertically downward.

  When the vertical direction is determined in this way, FIG. 3 is a cross-sectional view along the horizontal plane of the laminate-type battery 1 of FIG. 2, FIG. 4 is a cross-sectional view of the laminate-type battery 1 of FIG. FIG. 3 is a cross-sectional view of the laminate type battery 1 of FIG. 2 taken along the line YY. In the partial XX sectional view of FIG. 4, the central part is mainly shown in the XX sectional view of FIG. 2, and left and right end portions are not shown. The power generation element 2 is not shown in the sectional view taken along the line YY in FIG.

  Here, FIGS. 4A and 5A show the state of the filter 21 before folding, and FIGS. 4B and 5B show the state of the filter 21 after folding. In all the embodiments of the present invention, as shown in FIG. 2, it is assumed that the two high-power tabs 8 and 9 are taken out from the first heat-sealed portion 12 unlike FIG. 1.

  The heat fusion part provided in the peripheral part of the laminate film 3 with the substantially same width | variety is distinguished as follows. That is, in FIG. 2, the upper heat fusion portion is located on the left side as the “first heat fusion portion” 12 and the lower heat fusion portion as the “second heat fusion portion” 13. The thermal fusion part is classified as a “third thermal fusion part” 14, and the thermal fusion part located on the right side is classified as a “fourth thermal fusion part” 15.

  Further, the four peripheral edges of the laminate film are distinguished as follows. That is, in FIG. 2, the peripheral portion of the laminate film located in the upper portion is set as the “first laminate film peripheral portion” 16, and the peripheral portion of the laminate film located in the lower portion is set as the “second laminate film peripheral portion” 17. The periphery of the laminate film is classified as a “third laminate film periphery” 18, and the laminate film periphery located on the right side is classified as a “fourth laminate film periphery” 19.

  When gas expansion occurs inside the battery 1, a pressure release valve is provided at the peripheral edge 17 of the second laminate film in order to quickly release the gas inside the battery 1 to the outside of the battery 1. Specifically, the pressure release valve is a notch portion 20 provided substantially at the center of the second laminate film peripheral edge portion 17. In the second heat fusion part 13, the heat fusion width at a position where the notch 20 is present is narrower than the heat fusion width at a position other than the notch 20. By providing the notch portion 20 at substantially the center of the second laminate film peripheral edge portion 17, the heat fusion strength at a position where the notch portion 20 is present is weaker than the heat fusion strength at a position other than the notch portion 20. . When gas expansion occurs inside the battery 1, the fusion of the two laminate films 3 peels off first at the position where the notch 20 is located, and the gas inside the battery 1 is released from the peeled portion (pressure release valve). The battery 1 is quickly released outside. Here, peeling of the two laminated films 3 that have been fused is also referred to as “cleaving”.

  Hereinafter, one rectangular laminate film 3 that covers the vertical upper side of the power generation element 2 is identified as “upper laminate film” 3A, and the other rectangular laminate film 3 that covers the vertical lower side of the power generation element 2 is identified as “lower laminate film” 3B. . The notch 20 provided in the upper laminate film 3A is distinguished by an “upper notch” 20A and a notch 2018 lower notch 20B provided in the lower laminate film 3B.

  As shown in FIG. 3, the cutout portion 20 is generally provided in the second laminate film peripheral portion 17 on the side opposite to the first laminate peripheral portion 16 from which the high voltage tabs 8 and 9 are taken out. . However, the position where the notch 20 is provided is not necessarily limited to the second laminated film peripheral part 17, and it can be considered to be provided in the third laminated film peripheral part 18 or the fourth laminated film peripheral part 19. Note that a notch 20 is provided in the first laminate film peripheral portion 16 because a strong heat-sealing material is used for fusing the high-power tabs 8 and 9 and the high-heat tabs 8 and 9 have high heat dissipation. That is not suitable.

  When the laminate-type battery 1 is abnormal, the peripheral edge of the laminate film having the notch is cleaved, and the organic gas derived from the electrolyte generated from the inside of the battery 1 blows out to the outside, and from the inside of the battery 1 to the outside of the battery 1. It has been found that the electrode and aluminum powder are scattered.

  As used herein, “at the time of abnormality” means that one of the laminate film peripheral portions (second laminate film peripheral portion 17) having the gas release valve (notch portion 20) is cleaved and the powder is scattered from the inside of the battery. This is when the temperature is abnormal. In the event of temperature abnormalities (hereinafter also referred to simply as “temperature abnormalities”) when one whole of the peripheral edge of the laminate film having the gas release valve is cleaved and the powder is scattered from the inside of the battery, for example, an automobile equipped with an assembled battery may cause a fire. Occurs in the case of encounter. The separator 5 interposed between the positive electrode 6 and the negative electrode 4 is required to have a function of insulating the positive electrode 6 and the negative electrode 4 so that the positive electrode 6 and the negative electrode 4 are not in direct contact with each other, and a function of allowing the electrolyte to come and go. The For this reason, the separator 5 is formed of a porous thermoplastic resin such as polyethylene or polypropylene. The separator 5 formed from such a thermoplastic resin easily contracts when the ambient temperature of the battery 1 rises to around 100 ° C. The separator area is made slightly larger than the electrode area to prevent the positive electrode 6 and the negative electrode 4 from coming into direct contact with each other. However, when the ambient temperature of the battery 1 becomes high due to temperature abnormality, the separator 5 contracts and the initial area is larger than the initial area. Get smaller. When the peripheral portion of the separator 5 contracts mainly, there is no separation between the peripheral portion of the positive electrode 6 and the peripheral portion of the negative electrode 4, a short circuit occurs, a large current flows, and a large temperature increase due to Joule heat generation occurs. Then, the electrolyte solution sealed in the battery 1 is vaporized, and the volume of the battery 1 is suddenly increased (that is, the battery 1 is swollen), leading to the entire second laminate film peripheral edge portion 17 being cleaved.

  In a can-type battery having a safety valve inside the battery cover, a layer holding a material that adsorbs a gas is provided between the battery cover and the safety valve in order to prevent powder scattering from the inside when the temperature is abnormal. is there. In this conventional can-type battery, when the internal pressure rises due to temperature abnormality, the safety valve operates (breaks) to release the internal pressure. At this time, gas or solid matter containing harmful organic matter is ejected, but the gas adsorbent serves as a kind of filter to capture the organic matter and solid matter in the gas.

  In the can-type battery, the outer frame is formed more firmly than the laminate-type battery 1, so an easy-to-cleave part (that is, a safety valve) is intentionally made in the gas escape path and only around the safety valve. If a gas adsorbent is provided, all organic substances and solids in the gas can be captured. If the conventional can-type battery technology is applied to the laminated battery 1 as it is, a filter (powder trapping mechanism) that captures powder scattered from the inside of the battery to the outside of the battery only around the notch 18 can be provided. It will be good.

  However, in the laminate type battery 1 covered with a battery exterior material that is relatively softer than the can type battery, when the internal pressure of the laminate type battery 1 suddenly rises due to a temperature abnormality, Rather than cleaving only in the vicinity of the upper and lower cutout portions 20A and 20B located at the center, the entire second laminate film peripheral edge portion 17 is cleaved.

  This will be described using the current laminated battery 1. FIG. 6 is a plan view of the current laminated battery 1, and FIG. 7 is a schematic view of the laminated battery 1 shown in FIG. Here, Fig.7 (a) has shown the state of the laminated battery 1 before temperature abnormality generate | occur | produces. As shown in FIG. 7A, the upper and lower laminate films 3A and 3B are not swollen in the vertical direction (the vertical direction in FIG. 7).

  When the temperature is abnormal, a rapid volume increase (that is, swelling of the battery 1) occurs due to vaporization of the electrolyte accompanying a large temperature rise due to Joule heat generation, and the upper and lower laminate films 3A and 3B bulge outward. After the upper and lower laminate films 3A and 3B are fully expanded outward, the pressure inside the battery 1 increases and becomes higher. This high pressure is directed toward the portion having a low degree of thermal fusion, that is, the cutout portion 20 and first cleaves the upper and lower cutout portions 20A and 20B as shown in FIG. 7B. Then, since the high pressure gas ejected from the inside is vigorously ejected and the gas pressure acts, as shown in FIG. 7 (c), the cleavage extends to the entire peripheral edge portion 17 of the second laminate film and the second laminate that has been cleaved. The gas and powder inside the battery 1 jump out in one direction (downward in FIG. 6) from the entire film peripheral part 17.

  As described above, if the conventional can-type battery technology is applied to the current laminated battery 1 as it is and the filter is provided only around the notch 18, the powder 1 scattered from the inside of the battery 1 is all captured. It is not possible.

  Therefore, in the first embodiment of the present invention, a powder trapping mechanism that traps the powder scattered from the inside of the battery 1 at the time of temperature abnormality in which the entire peripheral edge portion of the second laminate film 17 is cleaved and the powder is scattered from the inside of the battery 1 is provided. The two laminated film peripheral portions are located between the power generation element 2 and the cutout portion 20 and are orthogonal to the second laminated film peripheral portion 17 (one of the laminated film peripheral portions having the gas release valve). It is provided until reaching each of the third laminated film peripheral edge 18 and the fourth laminated film peripheral edge 19.

  Specifically, the powder capturing mechanism of the first embodiment is a filter 21 formed of a net material, and the periphery of the filter 21 and the inner surfaces of the upper and lower laminate films 3A and 3B facing the periphery of the filter 21 are provided. Weld. Here, fusion is performed by heat fusion. Further, the filter 21 is flat, and the flat filter 21 is housed inside the battery 1 in a state where the filter 21 is folded one or more times. In addition, the planar net | network material of 1st Embodiment shall have the characteristic which does not shrink | contract (deform) in the surface direction.

  The filter is not limited to a planar mesh material, and may be a planar punching material or a filter formed of a planar porous body. As the material of these netting material, punching material or porous body, metal, heat resistant resin, flame retardant resin or ceramics can be used.

  For example, the planar net material includes a metal net, a heat resistant resin net, a flame retardant resin net, and a ceramic net. Examples of the wire mesh include stainless steel mesh, copper mesh, and aluminum mesh. Examples of the heat resistant resin net include polyimide mesh, phenylene sulfite mesh, and nylon mesh. Examples of the ceramic net include glass mesh, alumina mesh, and zirconia mesh.

  The opening (size of the mesh) of the planar mesh material is set to a length that can capture the powder scattered from the inside of the battery 1. For example, the mesh material has an opening of 3 mm or less. In this case, the openings are the same throughout the filter 21.

  The flat punching material includes a punching metal or a punching polymer film. Examples of a material that can be a punching metal include stainless steel, copper, nickel, aluminum, and titanium. Examples of a material that can be a punching polymer film include a polyethylene film, a polypropylene film, a nylon film, a polystyrene film, and a polyvinyl chloride film.

  The planar porous body includes a metal porous body and a resin porous body. Examples of the metal porous body include an aluminum porous body, a copper porous body, a stainless steel porous body, a nickel porous body, and a titanium porous body. Examples of the resin porous body include a polyimide porous body, a phenylene sulfite porous body, a nylon porous body, a polypropylene porous body, and a polycarbonate porous body.

  Here, a general punching material and a porous material are listed. The first embodiment is intended for a case where a punching material having a property that does not contract or a porous material having a property that does not contract is formed in a planar shape. On the other hand, as will be described later, in the second and third embodiments, the punching material having a property that can be shrunk (deformed) in at least one direction or a porous body having a property that can be shrunk (deformed) in at least one direction is flat. This is intended for the case of forming and using a shaped filter. Therefore, the punching material and the punching material having the characteristic that does not contract from the punching material and the porous material having the characteristic that does not contract are used as the filter of the first embodiment. On the other hand, a punching material having characteristics that can contract (deform) in at least one direction and a porous body having characteristics that can contract (deform) in at least one direction are used as the filters of the second and third embodiments.

  When a punching material having a property that does not contract or a porous material having a property that does not contract is formed in a planar shape, the hole diameter of the punching material or the porous material is set to a diameter capable of capturing powder scattered from the inside of the battery 1. For example, the hole diameter is 3 mm or less. In this case, the hole diameter is the same throughout the filter 21.

  On the other hand, as a punching material used as a filter of a sixth embodiment described later, holes 62 are formed in the surface at equal intervals as shown in FIG. 24 and FIG. Only those having a dome portion 63 protruding in the direction (upward in FIG. 25A) are targeted.

  Next, an example of how the filter 21 is provided inside the battery 1 when the power generating element 2 is sealed with the two separated rectangular laminate films 3A and 3B will be described. The method of sealing the power generation element 2 with the rectangular laminate film 3 is not limited to this. For example, a second method may be used in which one rectangular laminate film is folded at the center, and the power generation element 2 is housed and sealed between the folded laminate films. This second method is different from the first method in which the power generating element 2 is sealed with two rectangular laminate films 3A and 3B in that there are three heat-sealing portions. And in any method, the notch part 20 (gas release valve) is provided in one of the peripheral parts of the laminate film joined by heat sealing | fusion.

  Step 1: When sealing the power generation element 2 with the two rectangular laminate films 3A and 3B, the lower laminate film 3B is first laid horizontally, and the power generation element 2 is disposed at the center of the laid lower laminate film 3B.

  Step 2: A filter 21 having a predetermined area and a length substantially the same as the length of the second laminated film peripheral edge portion 17 is taken out or cut out from a flat filter as a raw material. The outer shape of the filter 21 is an ellipse having a major axis and a minor axis (see FIG. 8), and is taken out by cutting or cutting so that the minor axis direction becomes the vertical direction. The taken-out filter 21 is folded once or more as shown in FIG.

  Step 3: The heat sealing material 22 is applied to the periphery (for example, the vertical upper end 21a and the vertical lower end 21b) of the creased filter 21 (see FIG. 4A). As the heat sealing material, thermoplastic resins such as polyethylene, polypropylene, polystyrene, polyvinyl chloride, and nylon can be used.

  Step 4: The filter 21 to which the heat-sealing material 22 is applied is provided between the notch portion 20 and the power generation element 2 as shown in FIG. In addition, one horizontal end (left end in FIG. 3) of the filter 21 reaches the third laminate film peripheral edge 18, and the other horizontal end (right end in FIG. 3) reaches the fourth laminate film peripheral edge 19. It is placed in parallel with the peripheral edge 17 of the second laminate film.

  Step 5: Cover the power generating element 2 from above with the upper laminate film 3A so that the upper cutout portion 20A faces the lower cutout portion 20B, and fold the filter 21 vertically downward according to the crease. Immediately after covering the upper laminate film 3A, the filter 21 is in a state before being folded as shown in FIGS. 4A and 5A, but the upper laminate film 3A is pressed vertically downward according to the crease. As a result, the filter 21 is folded as shown in FIGS. 4B and 5B.

  Step 6: With the filter 21 folded, any one of the third laminated film peripheral portion 18 and the fourth laminated film peripheral portion 19 among the four laminated film peripheral portions 16 to 19 of the two laminated films 3A and 3B. Select. For example, if the third laminated film peripheral edge 18 is selected, the heat-sealed portions 12, 13, and 15 which are the peripheral edges of the remaining three laminated film peripheral edges 16, 17, and 19 that are not selected are bonded by thermal fusion. .

  A normal laminate film has a three-layer structure in which a polyethylene film, an aluminum metal film, and a nylon film are laminated in this order. The lower laminate film 3B is laid so that the polyethylene film is on the vertical upper surface, and the upper laminate film 3A is Cover the polyethylene film so that it is on the bottom. As a result, the polyethylene film layer on the inner surface side is melted and bonded by heat. At this time, the vertical upper end 21a of the filter 21 and the vertical lower surface 3AA (laminate film inner surface) of the upper laminate film 3A, and the vertical lower end 21b of the filter 21 and the vertical upper surface 3BB (laminate film inner surface) of the lower laminate film 3B Are joined by the heat-sealing material 22.

  Step 7: The third laminated film peripheral portion 18 that has not been heat-sealed is directed vertically upward, and the third laminated film peripheral portion 18 is opened to electrolyze the inside of the battery exterior material (3) (inside the battery 1). Inject liquid.

  Step 8: After the electrolyte has sufficiently penetrated into the inside of the battery 1, the third heat fusion part 14, which is the periphery of the third laminate film peripheral part 18, which is not thermally fused while venting air from the battery 1. Joining by heat fusion (that is, vacuum packing). As a result, the power generation element 2 and the filter 21 are sealed inside the battery 1.

  Step 9: A charger (not shown) is connected to the high voltage tabs 8 and 9 of the battery 1 formed in this way, and the first charging is performed.

  Here, the effect of this embodiment is demonstrated.

  According to the present embodiment, the power generation element 2 is formed by laminating the positive electrode 6 and the negative electrode 4 with the separator 5 interposed therebetween, and all or four peripheral edges of the laminate film using the rectangular laminate film 3 as the battery exterior material or A part of the power generation element 2 is sealed by joining a part by heat fusion, and a notch 20 (pressure inside the battery) is formed in the second laminate film peripheral part 17 (one of the four laminate film peripheral parts). In a thin laminated battery 1 having a gas release valve that cleaves and releases the gas inside the battery when the temperature rises, the second laminate film peripheral portion 17 (one of the peripheral portions of the laminate film having the gas release valve) A filter 21 (powder trapping mechanism) that traps the powder scattered from the inside of the battery 1 when the temperature is abnormal when the whole is cleaved and the powder is scattered from the inside of the battery 1. And the cutout portion 20 (gas release valve), and orthogonal to one of the third laminate film peripheral portion 18 and the fourth laminate film peripheral portion 19 (laminate film peripheral portion having the gas release valve). It is provided until reaching each of the two laminate film peripheral portions). When the temperature is abnormal, the filter 21 (powder capturing mechanism) covers the space formed by the entire cleaved second laminate film peripheral edge portion 17, and the powder scatters from the whole cleaved second laminate film peripheral edge portion 17 to the outside of the battery 1. Since this filter 21 captures, even in the laminated battery 1 covered with the battery outer packaging material (3) that is relatively softer than the can-type battery, the powder is transferred from the inside of the laminated battery 1 to the outside. It is possible to prevent scattering.

  According to the present embodiment, the powder capturing mechanism is a filter 21 formed of a mesh material, and the periphery of the filter 21 (vertical upper end 21a and vertical lower end 21b) and the inner surface of the laminate film facing the peripheral edge of the filter 21. Since 3AA and 3BB are welded (see FIG. 8), even if the crack is spread over the entire peripheral portion 17 of the second laminate film, the filter 21 is blown out of the battery 1 by losing the momentum of the gas ejected from the battery 1 inside. In this way, it is possible to continue capturing the powder scattered from the inside of the battery 1 to the outside of the battery 1.

  According to the present embodiment, the filter 21 is planar, and the planar filter 21 is stored in the battery 1 in a folded state at least once (see FIGS. 5A and 5B). When the split spreads to the entire periphery of the second laminate film 17 sometimes, the periphery (21a, 21b) of the filter 21 follows this movement as shown in FIG. ). As a result, it is possible to suppress the generation of a gap between the peripheral edge (21a, 21b) of the filter 21 and the laminate film inner surfaces 3AA, 3BB, and the filter 21 causes powder scattered from the inside of the battery 1 to the outside of the battery 1 by the filter 21. It can be captured without leakage. Here, FIG. 8 is a schematic view of the laminate type battery 1 of FIG. 2 as viewed in the direction of arrow Z when the temperature is abnormal.

  When the entire second laminate film peripheral edge portion 17 is cleaved when the temperature is abnormal, the spatial shape generated in the second laminate film peripheral edge portion 17 in a cleaved state is almost elliptical. Regardless of the space shape, for example, if the outer shape of the filter 21 is rectangular, a bulky portion is produced when the filter 21 is housed in the battery 1. Storage space is created. As a result, the volumetric efficiency of the battery 1 decreases. On the other hand, according to the present embodiment, the filter 21 has an elliptical shape that becomes thinner toward both ends in the major axis direction in accordance with the spatial shape generated in the entire second laminate film peripheral edge portion 17 by cleavage. That is, the shape becomes relatively narrower as it approaches the third laminated film peripheral portion 18 and the fourth laminated film peripheral portion 19 (two laminated film peripheral portions orthogonal to one of the laminated film peripheral portions having the gas release valve). Therefore, the filter 21 can be stored in the battery 1 without being bulky.

(Second Embodiment)
FIG. 9 is a plan view of the laminate type battery 1 of the second embodiment. Again, the vertical direction is determined as the battery 1 is arranged horizontally. That is, in FIG. 9, the front side of the paper is vertically upward and the back side of the paper is vertically downward.

  When the vertical direction is determined in this way, FIG. 10 is a cross-sectional view along the horizontal plane of the laminate-type battery 1 of FIG. 9, FIG. 11 is a partial cross-sectional view of the laminate-type battery 1 of FIG. FIG. 10 is a cross-sectional view of the laminate type battery 1 of FIG. 9 taken along the line YY. In the partial XX sectional view of FIG. 11, the central part is mainly shown in the XX sectional view of FIG. 9, and the left and right end portions are not shown. The power generation element 2 is not shown in the cross-sectional view along the line YY in FIG. The same parts as those in FIGS. 2, 3, 4, and 5 of the first embodiment are denoted by the same reference numerals.

  Here, FIGS. 11 (a) and 12 (a) show the state of the filter 31 before contraction (deformation), and FIGS. 11 (b) and 12 (b) show the state of the filter 31 after contraction. Show.

  In the first embodiment, since the filter 21 is formed of a planar mesh material having a characteristic that does not contract, the planar filter 21 is stored in the battery 1 in a state of being folded once or more. On the other hand, in the second embodiment, the filter 31 (powder capturing mechanism) is formed of a porous body that can contract (deform) in at least one direction, and the filter 31 is accommodated inside the battery 1 in a contracted (deformed) state. Here, “shrinkable” means that the original shape can be shrunk. Further, as will be described later, when returning from a contracted state to a state before contracting, it is assumed that it does not become larger than the original state.

  Note that the filter 31 of the second embodiment is also generally planar, but if the thickness of the filter 31 is compared with the filter 21 of the first embodiment, the filter 31 of the second embodiment is better. It is thicker than the filter 21 of the first embodiment (see FIGS. 5 and 12). However, even if the thickness of the filter 31 of the second embodiment is the same as that of the filter 21 of the first embodiment, the thickness of the filter 31 is reduced as long as it can contract (deform) in one direction (vertical direction). It doesn't matter what you do.

  Since an example of a general planar porous body is given in the first embodiment, a porous body having a property capable of contracting in at least one direction is selected from the planar porous bodies mentioned in the first embodiment. The filter 31 of the second embodiment is formed using the selected porous body.

  In the second embodiment, when the filter 31 is restored from the contracted state when the temperature is abnormal, the diameter of the hole is larger than that when the filter 31 is in the contracted state. Since the filter 31 captures the powder scattered from the inside of the battery 1 in a state where the filter 31 is restored from the contracted state when the temperature is abnormal, the diameter of the hole when the state is restored to the state before the contraction is obtained. The diameter is such that the powder scattered from the inside of the battery 1 can be captured. For example, the hole diameter is 3 mm or less. In this case, the hole diameter is the same throughout the filter 31.

  Here, even if it is a planar mesh material or a planar punching material, it is a porous material having a property that can be contracted (deformed) in at least one direction. It does not matter if the filter 31 is formed in place of the body.

  Next, an example of how the filter 31 is provided inside the battery 1 when the power generating element 2 is sealed with the two separated rectangular laminate films 3 will be described with reference to FIGS.

  Here, FIG. 13 is a plan view of the filter 31 of the second embodiment. Of these, FIG. 13A shows the state of the filter 31 before contraction, and FIG. 13A shows the state of the filter 31 after contraction by the press. 14 is a cross-sectional view taken along line XX of FIG. 14A shows the state of the filter 31 before the temperature abnormality occurs, and FIG. 14B shows the state of the filter 31 when the temperature abnormality occurs as a model.

  Step 1: When sealing the power generation element 2 with the two rectangular laminate films 3A and 3B, the lower laminate film 3B is first laid horizontally, and the power generation element 2 is disposed at the center of the laid lower laminate film 3B.

  Step 2: A planar filter as a raw material is formed of a porous body that can contract (deform) in at least one direction. From this planar filter as a raw material, as shown in FIG. 13A, an elliptical filter 31 having a major axis length and a predetermined area almost the same as the length of the second laminated film peripheral edge portion 17 is pierced. Or cut and take out. Here, since the filter 31 formed in an elliptical shape is contracted in the short axis direction, the filter 31 as a raw material can be shrunk or cut so that the contractible direction of the filter and the short axis direction of the filter 31 coincide with each other. It is necessary to do.

  The outer shape of the filter 31 is elliptical because when the temperature of the second laminate film peripheral part 17 is entirely cleaved when the temperature is abnormal, the spatial shape of the second laminate film peripheral part 17 generated by the cleavage is elliptical. Since it is known, it matches with the space shape of the second laminate film peripheral edge portion 17 at this time.

  When the filter 31 in which the shrinkable direction and the minor axis direction are matched in this way is pressed in the minor axis direction of the ellipse, it is plastically deformed and contracted (shrinks) as shown in FIG. . Here, the case where the filter 31 contracts due to plastic deformation has been described. However, the filter 31 may contract due to elastic deformation. When the filter 31 is elastically deformed, it is not necessary to press. This is because it seems to collapse (elastically deform) due to the pressure (that is, atmospheric pressure) acting from the outside of the battery 1 when vacuum packing.

  Step 3: The heat sealing material 22 is applied to the periphery (for example, the vertical upper end 31a and the vertical lower end 31b) of the filter 31 contracted by the press (see FIG. 11A). As shown in FIG. 10, the filter 31 to which the heat sealing material 22 is applied is provided between the notch portion 20 and the power generation element 2. And one horizontal direction end (left end in FIG. 10) of the filter 31 reaches the third laminate film peripheral edge 18, and the other horizontal end (right end in FIG. 10) reaches the fourth laminate film peripheral edge 19. It is placed in parallel with the peripheral edge 17 of the second laminate film.

  Step 4: The power generation element 2 is covered from above with the upper laminate film 3A so that the upper cutout portion 20A faces the lower cutout portion 20B. When the upper laminate film 3A is covered, the filter 31 is contracted in the vertical direction as shown in FIGS. 11 (b), 12 (b), and 14 (a).

  11 and 12 are described as images, and do not show actual modifications of the filter 31. FIG. That is, if the filter 31 is previously plastically deformed by pressing, the filter 31 is shown in FIGS. 11B and 12B at the timing when the upper and lower surfaces of the power generating element 2 are covered with the upper laminate film 3A. It will be in a contracted state. That is, if the filter 31 is plastically deformed by pressing, the state shown in FIGS. 11A and 12A (the state before shrinking) cannot be taken.

  On the other hand, when the filter 31 is elastically deformed, the filter 31 is in a state before being contracted as shown in FIGS. 11A and 12A at the timing when the power generating element 2 is covered with the upper laminate film 3A. Become. Then, the filter 31 shifts to the state (shrinked state) shown in FIGS. 11B and 12B by the vacuum pack. In addition, the thickness of the filter 31 in the contracted state is larger than before the contraction (see FIGS. 12A and 12B).

  Step 5: Of the four laminate film peripheral portions 16 to 19 of the two laminate films 3A and 3B, one of the third laminate film peripheral portion 18 and the fourth laminate film peripheral portion 19 is selected. For example, if the third laminated film peripheral edge 18 is selected, the heat-sealed portions 12, 13, and 15 which are the peripheral edges of the remaining three laminated film peripheral edges 16, 17, and 19 that are not selected are bonded by thermal fusion. . At this time, the vertical upper end 31a of the filter 31 and the vertical lower surface 3AA (laminate film inner surface) of the upper laminate film 3A, and the vertical lower end 21b of the filter 31 and the vertical upper surface 3BB (laminate film inner surface) of the lower laminate film 3B Are joined by the heat-sealing material 22.

  Step 6: The third laminated film peripheral edge 18 that has not been heat-sealed is directed vertically upward, and the third laminated film peripheral edge 18 is opened to electrolyze the inside of the battery exterior material (3) (inside the battery 1). Inject liquid.

  Step 7: After the electrolyte has sufficiently penetrated into the battery 1, the third heat fusion part 14, which is the periphery of the third laminate film peripheral part 18, which is not thermally fused while venting air from the inside of the battery 1. Are joined by thermal fusion (that is, vacuum packed). As a result, the power generation element 2 and the filter 31 are sealed inside the battery 1.

  Step 8: A charger (not shown) is connected to the high voltage tabs 8 and 9 of the battery 1 formed in this way, and the first charging is performed.

  Also according to the second embodiment, basically the same effects as the first embodiment can be obtained.

  Here, an effect slightly different from the first embodiment will be described. According to the second embodiment, the filter 31 is formed of a porous body that can contract (deform) in at least one direction, and the filter 31 contracts (deforms). ) Is stored in the battery 1 inside. For this reason, when tearing spreads over the entire periphery of the second laminate film edge 17 when the temperature is abnormal, the periphery (31a, 31b) of the filter 31 follows this movement as shown in FIG. 14 (b). Plastic deformation (or elastic deformation) swells in the minor axis direction (vertical direction). As a result, it is possible to suppress the generation of a gap between the peripheral edge (31a, 31b) of the filter 31 and the laminate film inner surfaces 3AA, 3BB, and the powder scattered from the inside of the battery 1 to the outside of the battery 1 is completely captured. be able to.

  Further, according to the second embodiment, the horizontal storage space required before and after contracting (deforming) the filter 31 is greater than the horizontal storage space required before and after folding the filter 21 in the first embodiment. Since the size can be reduced (see FIGS. 5 and 12), the volumetric efficiency of the battery 1 can be improved as compared with the first embodiment.

(Third embodiment)
FIG. 15 is a plan view of the laminated battery 1 according to the third embodiment. Again, the vertical direction is determined as the battery 1 is arranged horizontally. That is, in FIG. 15, the front side of the paper is vertically upward and the back side of the paper is vertically downward.

  When the vertical direction is determined in this way, FIG. 16 is a cross-sectional view taken along the horizontal plane of the laminated battery 1 of FIG. 15, and FIG. 17 is a plan view of the filter 32 of the third embodiment. 17A shows the state of the filter 31 before being contracted, and FIG. 17A shows the state of the filter 31 after being contracted by a press. 18 is a cross-sectional view taken along line XX in FIG. 18A shows a state of the filter 31 before the temperature abnormality occurs, and FIG. 18B shows a state of the filter 31 when the temperature abnormality occurs. The same parts as those in FIGS. 9, 10, 13, and 14 of the second embodiment are denoted by the same reference numerals.

  The third embodiment is different from the filter 31 of the second embodiment only in the outer shape of the filter 32. That is, also in the third embodiment, the planar filter 32 is formed of a porous body having characteristics that can contract (deform) in at least one direction. From a planar filter as a raw material, an isosceles triangular filter 32 (powder trapping) having a base length and a predetermined area substantially the same as the length of the second laminate film peripheral edge portion 17 as shown in FIG. Remove the mechanism). Here, the filter 31 formed in the shape of an isosceles triangle is contracted (deformed) in a direction orthogonal to the base, so that the contractible direction of the filter as the raw material matches the direction orthogonal to the base of the filter 31. It is necessary to pierce and cut like this.

  When the filter 32 in which the shrinkable direction and the direction orthogonal to the base are made to coincide with each other is pressed in the direction orthogonal to the base, it is plastically deformed and contracted as shown in FIG. To do). Here, the case where the filter 32 contracts due to plastic deformation has been described. However, the filter 32 may contract due to elastic deformation. When the filter 32 is elastically deformed, pressing is not necessary. This is because, as described above in the second embodiment, when vacuum packing is performed, it is considered that the pressure (ie, atmospheric pressure) acting from the outside of the battery is crushed (elastically deformed).

  The heat sealing material 22 is applied to the periphery (for example, the vertical upper ends 32a and 32b and the vertical lower end 32c) of the filter 32 contracted by the press. The filter 32 to which the heat sealing material 22 is applied is provided between the notch 20 and the power generation element 2 as shown in FIG. In addition, one horizontal end (left end in FIG. 16) of the filter 32 reaches the third laminate film peripheral edge 18, and the other horizontal end (right end in FIG. 16) reaches the fourth laminate film peripheral edge 19. It is placed in parallel with the peripheral edge 18 of the second laminate film.

  When the filter 32 is arranged in this way, when the tearing spreads over the entire periphery of the second laminate film 17 when the temperature is abnormal, the periphery (32a, 32b) of the filter 32 is moved to this movement in FIG. 18 (b). As shown, plastic deformation (or elastic deformation) follows and swells in a direction (vertical direction) perpendicular to the base.

  In the third embodiment, the case where the outer shape of the filter 32 is an isosceles triangle has been described, but it is not limited to this outer shape. For example, an isosceles trapezoidal shape or a rhombus shape may be used.

  In the third embodiment, the same effects as in the second embodiment can be obtained.

(Fourth embodiment)
FIG. 19 is a cross-sectional view along the horizontal plane of the laminated battery 1 of the fourth embodiment. The same parts as those in FIG. 3 of the first embodiment are denoted by the same reference numerals.

  In the first embodiment, the filter 21 is formed of one type of flat mesh material with uniform openings. On the other hand, in the fourth embodiment, the filter 21 '(powder trapping mechanism) is formed by three types of planar mesh materials having different openings. It is assumed that the three types of planar net members of the fourth embodiment also have a characteristic that does not shrink (deform) in the surface direction.

  For the three types of planar mesh materials, the first planar mesh material, the second planar mesh material, and the third planar mesh material are arranged in the descending order of mesh, and the first filter 41 is formed by the first planar mesh material. Assuming that the second filter 42 and the third filter 43 are formed of the two planar mesh materials and the third filter 43, the planar mesh material having a large mesh opening as shown in the enlarged view below FIG. The filters are arranged so that the power generation element 2 side is closer to the filter. Note that the number of planar mesh members having different openings is not limited to three. The number of planar mesh members having different mesh openings may be at least two.

  This divides the particle diameter of the powder scattered from the inside of the battery 1 to the outside of the battery 1 into approximately three, and different filters are used depending on the particle diameter. That is, assuming that the particle diameter is divided into three, roughly large, medium, and small, the first filter 41 first captures the large diameter powder, and then the second filter 42 captures the medium diameter powder. Finally, a small diameter powder is captured by the third filter 43. Thus, clogging of the entire filter 21 ′ can be prevented by combining (stacking) the filters 41 to 43 having different openings so as to form one filter 21 ′. Note that the outer shape of one filter 21 'is an ellipse or an isosceles triangle.

  Adjacent two filters are joined by thermal fusion or attached with an adhesive 45. For example, after applying a thermoplastic resin as a heat sealing material between adjacent filters, the adjacent filters can be heat-sealed by raising the temperature to a temperature close to the melting point. As the adhesive 45, an epoxy adhesive or the like may be used.

  The material used for the filter 21 ′ of the fourth embodiment is not limited to the planar mesh material, and a single filter 21 ′ is formed by combining (stacking) three types of planar punching materials and planar porous bodies having different hole diameters. It does not matter if it is a thing. In this case, the planar punching material or the planar porous body is a planar punching material having a characteristic that does not contract or a planar porous body having a characteristic that does not contract.

  According to the fourth embodiment, when the filter 21 ′ is formed of a planar mesh material, the filter 21 ′ is composed of a plurality of filters 41 to 43 having different meshes, and the filter having a relatively coarse filter. 41 is disposed on the power generation element 2 side, and a relatively fine filter 43 is disposed on the notch 20 (gas release valve) side. This makes it possible to capture a relatively large particle size powder upstream of the gas flow and a relatively small particle size powder downstream, thereby preventing clogging of the filter 21 '. can do.

  Here, the “gas flow” in the fourth embodiment and the fifth and sixth embodiments to be described later refers to a gas flow ejected from the inside of the battery 1 to the outside of the battery 1 when the temperature is abnormal. This is a flow in a direction perpendicular to the peripheral edge 17 of the second laminate film, as shown in FIG.

(Fifth embodiment)
FIG. 20 is a cross-sectional view along the horizontal plane of the laminated battery 1 of the fifth embodiment. The same parts as those in FIG. 10 of the second embodiment are denoted by the same reference numerals.

  In the second embodiment, the filter 31 (powder trapping mechanism) is formed of a planar porous body that can contract (deform) in at least one direction. The pore diameter of the porous body used in the filter 31 is Uniform throughout. On the other hand, the fifth embodiment is the same as the second embodiment in that it is a planar porous body that can contract (deform) in at least one direction, but further combines three types of planar porous bodies with different pore diameters. One filter 31 'is formed (overlaid). In this case as well, the outer shape of one filter 31 'is an ellipse or an isosceles triangle.

  For the three types of planar porous bodies, the first planar porous body, the second planar porous body, and the third planar porous body are arranged in the descending order of the pore diameter. When the second filter 47 is formed of a planar porous body and the third filter 48 is formed of a third planar porous body, the planar porous body is formed of a planar porous body having a large pore diameter, as shown in the enlarged view below FIG. Arrange them so that the filter is closer to the power generation element 2 side. The number of planar porous bodies having different pore diameters is not limited to three. The number of planar porous bodies having different pore diameters may be at least two.

  This divides the particle diameter of the powder scattered from the inside of the battery 1 to the outside of the battery 1 into approximately three, and different filters are used depending on the particle diameter. That is, assuming that the particle diameter is divided into three, roughly large, medium and small, the first filter 46 first captures the large diameter powder, and then the second filter 47 captures the medium diameter powder. Finally, a small diameter powder is captured by the third filter 48. Thus, clogging of the entire filter 31 ′ can be prevented by combining (stacking) the filters 46 to 48 having different hole diameters to form one filter 31 ′.

  Adjacent two filters are joined by thermal fusion or attached with an adhesive 45. For example, after applying a thermoplastic resin as a heat sealing material between adjacent filters, the adjacent filters can be heat-sealed by raising the temperature to a temperature close to the melting point. As the adhesive 45, an epoxy adhesive or the like may be used.

  The material used for the filter 31 ′ of the fifth embodiment is not limited to a planar porous body, and a single filter 31 ′ is formed by combining (stacking) three types of planar punching materials having different pore diameters. It doesn't matter. In this case, the planar punching material is a planar punching material having a property that can contract (deform) in at least one direction.

  Also according to the fifth embodiment, the same effect as that of the fourth embodiment can be obtained. That is, according to the fifth embodiment, when the filter 31 ′ is formed of a planar porous body, the filter 31 ′ includes a plurality of filters 46 to 48 having different pore diameters, and the filter 46 having a relatively large pore diameter. Is disposed on the power generation element 2 side, and a filter 48 having a relatively small hole diameter is disposed on the notch 20 (gas release valve) side. This makes it possible to capture a relatively large particle size powder upstream of the gas flow and to capture a relatively small particle size downstream of the gas flow, thus preventing clogging of the filter 31 '. can do.

(Sixth embodiment)
FIG. 21 is a cross-sectional view along the horizontal plane of the laminated battery 1 according to the sixth embodiment. The same parts as those in FIG. 20 of the fifth embodiment are denoted by the same reference numerals.

  The fifth embodiment is a planar porous body that can contract (deform) in at least one direction, and forms one filter 31 ′ by combining (stacking) three types of planar porous bodies having different pore diameters. Met. On the other hand, the sixth embodiment is the same as the fifth embodiment in that the filter 51 (powder trapping mechanism) is formed of a planar porous body having characteristics that can contract (deform) in at least one direction. It differs from the fifth embodiment in that three different types of planar porous bodies are not combined. That is, the filter 51 is formed of a planar porous body that is integral but gradually changes in pore diameter in a direction (thickness direction) perpendicular to the surface. Specifically, the filter 51 is formed such that the hole diameter gradually decreases (changes) from one filter surface 51a toward the other filter surface 51b.

  Then, as shown in the enlarged view below FIG. 21, the filter surface 51a having a relatively large hole diameter is on the power generation element 2 side, and the filter surface 51b having a relatively small hole diameter is on the notch 20 side. Provide so that it comes out. In this case, the outer shape of one filter 51 is an ellipse or an isosceles triangle.

  In order to form the pore diameter so as to gradually change in the direction (thickness direction) perpendicular to the surface of the filter 51 in the same material, the following may be performed. For example, when forming a planar porous body with foamed foam, utilizing the fact that bubbles having different diameters are biased and solidified due to gravity, the planar porous body gradually changes its pore diameter from one surface to the other. And the filter 51 is formed of the planar porous body.

  The sixth embodiment is based on the premise that the filter 51 is formed of a planar porous body having a characteristic that can contract (deform) in at least one direction. However, the filter 51 is formed of a planar porous body having a characteristic that does not contract. This also applies to In order to form a flat porous body having a characteristic that does not shrink so that the pore diameter gradually changes from one surface to the other surface, the following method may be used. That is, when a ceramic is sintered, by mixing impurities appropriately and sintering, a planar porous body whose pore diameter gradually changes from one surface to the other surface is formed. The filter 51 is formed of a porous body.

  In the case where the filter 51 is formed of a planar porous body having a property that can contract in at least one direction, the filter 51 is housed inside the battery 1 in a contracted state. On the other hand, when the filter is formed of a planar porous body having a property that does not shrink, the filter is housed inside the battery 1 in a folded state at least once.

  According to the sixth embodiment, the pore diameter of the planar porous body used for the filter 51 decreases from the power generation element 2 side toward the cutout portion 20 (gas release valve) side, and thus a relatively large particle diameter. Can be captured on the upstream side of the gas flow, and powder having a relatively small particle size can be captured on the downstream side of the gas flow, so that the filter 51 can be prevented from being clogged.

(Seventh embodiment)
FIG. 22 is a plan view of the laminated battery 1 according to the seventh embodiment. Again, the vertical direction is determined as the battery 1 is arranged horizontally. That is, in FIG. 22, the front side of the paper is vertically upward and the back side of the paper is vertically downward.

  When the vertical direction is determined in this way, FIG. 23 is a cross-sectional view along the horizontal plane of the laminate type battery 1 of FIG. In FIG. 23, the same parts as those in FIG. 3 of the first embodiment are denoted by the same reference numerals. 24 is a schematic perspective view of the filter 61 of the seventh embodiment, and FIG. 25A is a cross-sectional view taken along the line XX of FIG. 24 (a cross-sectional view taken along a horizontal line passing through the row of holes 62).

  In the seventh embodiment, a filter 61 (powder trapping mechanism) is formed of a planar punching material (for example, punching metal) 61 having a property that does not contract, and the filter 61 is stored in the battery 1 in a folded state at least once. In this respect, the shape around the hole 62 of the filter 61 is different from that of the first embodiment. In addition, the planar punching material of 7th Embodiment shall also have the characteristic which does not shrink | contract (deform) in the surface direction.

  As shown in FIG. 25 (a), the planar punching material in which the holes 62 are formed at equal intervals in the plane is in one direction (upward in FIG. 25 (a)) perpendicular to the plane. A projecting dome 63 is provided around the hole 62.

  Here, for comparison, FIG. 25B shows a cross-sectional view in the case where the filter 65 is formed of a general planar punching material. In the filter 65 formed of a general planar punching material, the periphery of the hole 62 does not protrude in a direction orthogonal to the surface, and is a flat portion 66.

  From the filter as a raw material as shown in FIG. 24, FIG. 25 (a), or through an elliptical filter 61 having a major axis length and a predetermined area substantially the same as the length of the second laminated film peripheral edge 18, or Cut and take out. The extracted filter 61 is folded once or more in the same manner as described above with reference to FIG. The heat sealing material 22 is applied to the periphery (for example, the vertical upper end 61a and the vertical lower end 61b) of the creased filter 61 (see FIG. 26).

  As shown in FIG. 23, the filter 61 to which the heat-sealing material 22 is applied is provided between the notch portion 20 and the power generation element 2. And one horizontal direction end (left end in FIG. 23) of the filter 61 reaches the third laminated film peripheral edge 18, and the other horizontal end (right end in FIG. 23) reaches the fourth laminated film peripheral edge 19. It is placed in parallel with the peripheral edge 17 of the second laminate film. As shown in FIG. 25A, the filter 61 is arranged so that the apex of the dome portion 63 is on the power generation element 2 side.

  When the filter 61 is arranged in this way, when the tear spreads to the entire second laminate film peripheral edge portion 17 when the temperature is abnormal, the peripheral edges (61a, 61b) of the filter 61 are shown in FIG. Will follow and spread in the vertical direction.

  At this time, when the filter 61 is viewed from the power generation element 2 side, a tapered portion 64 is formed around the hole 62 (see FIG. 25A). According to the cross-sectional shape of the filter 61 shown in FIG. 25A, the gas is allowed to move only in one direction, so that the tapered portion 64 of the filter 61 functions as a check valve. That is, in FIG. 25A, the gas ejected from the inside of the battery 1 to the outside of the battery 1 when the temperature is abnormal is guided by the shape of the tapered portion 64 around the hole 62 and enters the hole 62. To the outside of the battery 1 (see the arrow pointing downward in FIG. 25A). On the other hand, air (oxygen) outside the battery 1 cannot enter the inside of the battery 1 from the hole 62 (see the upward arrow in FIG. 25A).

  On the other hand, in the case where the filter 65 is formed by general planar punching, the tapered portion 64 does not exist around the hole 62 when the filter 65 is viewed from either the upper or lower surface in FIG. When there is no gas ejection from the inside of the battery 1, air (oxygen) outside the battery 1 enters the inside of the battery 1 from the hole 62.

  In addition, instead of the punching material having the property of not shrinking, the filter is formed of the punching material having the property of shrinking in at least one direction, and the shape around the hole 62 of the filter 61 is shown in FIGS. The shape shown may be used. In this case, the filter 61 is stored in the battery 1 in a contracted state.

  According to the seventh embodiment, in addition to the functions and effects of the second embodiment, the following functions and effects can be obtained. That is, according to the seventh embodiment, in the case of the filter 61 formed of a planar punching material, the tip constriction portion 64 that constricts toward the punching hole 62 is formed on one side, and this tip constriction is formed. The surface on which the pool portion 64 is formed is disposed on the power generation element 2 side (see FIG. 25A). In the tapered portion 64, gas ejected from the inside of the battery 1 to the outside of the battery 1 is discharged to the outside of the battery 1 through the punching hole 62, but air (particularly oxygen) outside the battery 1 passes through the punching hole 62. It has a check valve function that prevents it from entering the inside. Thereby, the reverse flow of air into the battery 1 can be suppressed, and the phenomenon of ignition inside the battery 1 can be suppressed.

(Eighth embodiment)
FIG. 27 is a cross-sectional view along the horizontal plane of the laminated battery 1 of the seventh embodiment. The same parts as those in FIG. 2 of the first embodiment are denoted by the same reference numerals.

  In FIG. 27, when the battery 1 is severely deformed due to an unexpectedly large force, such as the battery 1 being crushed, the filter 25 comes into contact with the power generation element 2 when the filter 25 has electrical conductivity. It is conceivable to cause an internal short circuit.

  Therefore, in the eighth embodiment, when the filter 25 (powder capturing mechanism) has electrical conductivity, the battery 25 is deformed severely by covering the surface 25c of the filter 25 on the power generation element 2 side with the insulating material 71. At this time, even if the electrically conductive filter 25 comes into contact with the power generation element 2, an internal short circuit is not caused.

  Here, “the filter has electrical conductivity” means that the planar mesh material, planar punching material, or planar porous body that is the raw material of the filter has electrical conductivity. Here, the planar mesh material, the planar punching material, and the planar porous body may have any characteristics that do not contract, and those that have characteristics that can contract (deform) in one direction.

  The insulating materials include polymers and ceramics. Examples of the polymer include polyethylene, polypropylene, nylon, Teflon (registered trademark), and polyimide. Examples of the ceramic include alumina and zirconia. Coating with ceramic can be performed by vapor deposition (alumina vapor deposition, zirconia vapor deposition) or the like.

  According to the eighth embodiment, when the filter 25 has electrical conductivity, the surface 25c on the power generation element 2 side of the filter 25 is covered with the insulating material 71. Therefore, when the battery 1 undergoes severe deformation such as crushing, It can suppress that the filter 25 which has electroconductivity, and the electrode of the electric power generation element 2 contact, and short-circuit.

  In the embodiment, the case where the material can be deformed is described as being deformable. However, the present invention is not limited to this, and the case where the material can be expanded and contracted may be used. Here, it has been described above that “shrinkable” does not become larger than the original state when returning from the contracted state to the state before contracting. On the other hand, in the case of “extensible”, it is used in a concept including a case where the state is larger than the original state when returning from the contracted state to the state before contracting.

  In the embodiment, the case where the laminate type battery is a secondary battery has been described. However, the present invention can be applied to the case where the laminate type battery is a primary battery.

DESCRIPTION OF SYMBOLS 1 Laminate type battery 2 Power generation element 3 Laminate film 4 Negative electrode 5 Separator 6 Positive electrode 17 2nd laminate film peripheral part 20 Notch part (gas release valve)
21 Filter (powder trapping mechanism)
21 'filter (powder trapping mechanism)
25 Filter (powder trapping mechanism)
31 Filter (powder trapping mechanism)
31 'filter (powder trapping mechanism)
32 Filter (powder trapping mechanism)
51 Filter (powder trapping mechanism)
52 Filter (powder trapping mechanism)
61 Filter (powder trapping mechanism)

Claims (10)

By having a power generation element in which a positive electrode and a negative electrode are laminated via a separator, and using a rectangular laminate film as a battery exterior material, all or part of the four laminate film peripheral parts are joined by thermal fusion. , While sealing the power generation element,
In a thin laminated battery having a gas release valve that cleaves and releases the gas inside the battery when the pressure inside the battery rises to one of the peripheral parts of the laminate film bonded by heat fusion,
A powder trapping mechanism for trapping powder scattered from the inside of the battery at the time of abnormal temperature at which one whole of the peripheral portion of the laminate film having the gas release valve is cleaved and the powder is scattered from the inside of the battery, the power generation element and the gas A laminate type battery, which is provided until reaching each of the two peripheral edge portions of the laminate film which is positioned between the discharge valve and orthogonal to one of the peripheral edge portions of the laminate film having the gas release valve. The powder capturing mechanism is a filter formed of a netting material, a punching material or a porous body,
The laminate type battery according to claim 1, wherein the periphery of the filter is welded to the inner surface of the laminate film facing the periphery of the filter.   The laminate type battery according to claim 2, wherein the filter is flat and is stored in the battery in a state where the flat filter is folded at least once.   The laminate type battery according to claim 2, wherein the filter is formed of a porous body that can be deformed in at least one direction, and the filter is stored in the battery in a deformed state.   3. The laminate type battery according to claim 2, wherein the filter has a shape that becomes relatively thinner as it approaches the peripheral edge of each of the two orthogonal laminate films. When the filter is formed of the mesh material,
This filter consists of multiple filters with different roughness,
The laminate type battery according to claim 2, wherein a relatively coarse filter is disposed on the power generation element side, and a relatively fine filter is disposed on the gas release valve side. When it is a filter formed of the punching material or porous body,
This filter consists of multiple filters with different hole diameters,
The laminate type battery according to claim 2, wherein a filter having a relatively large hole diameter is disposed on the power generation element side, and a filter having a relatively small hole diameter is disposed on the gas release valve side.   3. The laminate type battery according to claim 2, wherein the pore diameter of the porous body decreases from the power generation element side toward the gas release valve side. 4. When the filter is formed of the punching material,
The tip constriction part which tapers toward the punching hole is formed on one side, and the surface on which the constriction part is formed is arranged on the power generation element side. Laminated battery. When the filter has electrical conductivity,
The laminated battery according to claim 1, wherein a surface of the filter on the power generation element side is covered with an insulating material.

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