JP4687052B2 - Sheet material type battery manufacturing method and sheet material type battery - Google Patents

Description

  The present invention relates to a sheet material type battery manufacturing method and sheet material mold formed by enclosing a battery power generation element with a sheet material, drawing both electrodes from the battery power generation element to the outside, and sealing an end of the sheet material It relates to batteries.

  In recent years, with the development of various electronic devices, there has been an increasing need for downsizing and space saving of electronic devices, and the batteries used therefor are also required to be thin and flexible. Therefore, the battery power generation element is hermetically sealed using a sheet-like laminate material. For example, as a sheet-like laminate material, a three-layer structure of a polyethylene layer, an aluminum foil layer, and a polyethylene layer is used. The power generation element is housed inside, the electrode is drawn out, and a lithium ion battery, a nickel metal hydride battery, etc. Is formed.

  If these batteries are called sheet-type batteries, the sheet-type batteries have a degree of freedom in shape and are suitable for small size and light weight. However, since an electrolyte is used, the joints of the sheet materials are airtight. It is necessary to seal. Moreover, since the power generation element deteriorates when exposed to a high temperature due to its property, it is necessary to prevent the power generation element from being subjected to a heat load during sealing.

  Patent Document 1 discloses that a hot-melt adhesive is sandwiched between seams of sheet material, and the seam portion is thermally welded with a heated press plate. Further, in Patent Document 2, since it is used as a power source for an electric vehicle or the like, a waterproof material having a concave shape is formed so that a sealed seam of the sheet material type battery is not opened or moisture does not enter from the seam. It is described that the cap is fitted and attached to the outer peripheral edge of the battery.

JP 2000-348695 A JP 2004-79434 A

  In the sheet material type battery, since it is necessary to pull out the electrode to the outside of the sheet material, it becomes a problem whether the vicinity of the electrode can be sealed tightly when sealing the joint of the sheet material. For example, in the case where the heated press plate of Patent Document 1 is used, the seam of the sheet material near the electrode has a step difference corresponding to the thickness of the electrode as compared with the place without the electrode, and due to variations in the size and shape of the electrode terminal. In the fixed shape hot press plate, the welding state in the vicinity of the electrode varies. As proposed in Patent Document 1, it is conceivable to use a press plate or a rubber plate in accordance with the level difference, but the sealing device is complicated and expensive.

  Moreover, in order to reinforce the variation in a sealing state and improve waterproofness, in patent document 2, although the waterproof cap which has a recessed part shape is fitted and attached to the battery outer periphery part, for example, a rectangular-shaped sheet | seat In the case of a material type battery, a cap must be fitted and attached to each of the four sides. In this case as well, a waterproof cap having a groove for passing the electrode must be prepared for drawing out the electrode. Furthermore, the operation | work which fits a cap through an electrode through the groove | channel and it attaches to a battery outer periphery part is also required.

  Thus, in the prior art, variations in sealing of sheet-type batteries, particularly welding in the vicinity of the electrodes, are likely to occur. To reinforce this, another member or additional work is required.

  An object of the present invention is to provide a method for manufacturing a sheet material type battery and a sheet material type battery capable of suppressing the welding of the joint of the sheet material, in particular, the dispersion of the welding in the vicinity of the electrode. Another object of the present invention is to provide a sheet material type battery manufacturing method and a sheet material type battery that can easily reinforce sealing of a seam of a sheet material.

  The sheet material type battery manufacturing method according to the present invention wraps a battery power generation element with a sheet material, draws both electrodes from the battery power generation element to the outside, and melts by heating between the joints at the end where the sheet material faces. A step of forming a semi-finished battery by sandwiching an adhesive material to be placed, placing the semi-finished battery in a hermetic sealing mold, cooling a mold portion where the power generation element for the battery is placed, And applying a heated and pressurized fluid only to the end portion of the sheet material to melt and hermetically seal the adhesive material at the end portion of the sheet material.

  Moreover, in the manufacturing method of the sheet material type battery which concerns on this invention, it is preferable that a heating pressurization fluid is the molten resin pressurized in the metal mold | die.

  Moreover, in the manufacturing method of the sheet material type battery according to the present invention, it is preferable to include a step of cross-linking the molten resin in which the end portion of the sheet material is sealed in the mold to form as a battery reinforcing material.

  Moreover, in the manufacturing method of the sheet material type battery according to the present invention, the battery reinforcing material is preferably formed into a frame shape along the hermetic sealing end portion around the battery.

  Further, in the method for manufacturing a sheet material type battery according to the present invention, the reinforcing material is formed into a frame shape on each of the upper and lower surfaces of the end portion of the sheet material along the periphery of the battery, and further in at least a part of the periphery of the battery. The sheet material is preferably formed so as to cover the side surface together with the upper and lower surfaces of the end portion of the sheet material and sandwich the end surface of the sheet material.

  Further, in the method for manufacturing a sheet material type battery according to the present invention, the reinforcing material is formed into a frame shape on each of the upper and lower surfaces of the end portion of the sheet material along the periphery of the battery, and further in at least a part of the periphery of the battery. In addition, it is preferable that the upper and lower frame-shaped materials are integrally connected and molded at the through hole portion at the end of the sheet material.

  In addition, the sheet material type battery according to the present invention is a battery that encloses a battery power generation element with a sheet material, draws both electrodes from the battery power generation element to the outside, and hermetically seals and stores the opposite ends of the sheet material In this case, the upper and lower frame-shaped members are formed in a frame shape on the upper and lower surfaces of the sheet material end along the periphery of the battery. A resin-molded reinforcement material connected to the resin-molded reinforcement material, and an adhesive material disposed between the joints of the sheet material end portions sandwiched by the resin-molded reinforcement material and melted by the resin molding heating, In addition, the end of the sheet material is hermetically sealed with the molten adhesive material.

  With the above configuration, after forming a semi-finished battery in which a heat-melt type adhesive is placed at the joint of the sheet material, it is placed in the mold and the mold part where the battery power generation element is placed is cooled. In addition, since the heating and pressurizing fluid is applied only to the end portion that is the joint of the sheet material, it is possible to heat and press only the joint portion of the sheet material without applying heat to the battery power generation element that is vulnerable to heating. . In addition, since fluid is used for heat and pressure at the joint of the sheet material, heating and pressurization is performed in accordance with the thickness of the electrode even where a difference in level is likely to occur at the joint of the sheet, such as an electrode lead-out portion. . Therefore, even if there is variation in the dimensional shape of the electrode portion, heating and pressurization are performed following the variation shape size, and variation in welding in the vicinity of the electrode can be suppressed.

  In addition, since the heated and pressurized fluid is a molten resin pressurized in the mold, a sheet material is obtained by applying a general resin molding technique to cool the mold part where the battery power generation element is arranged. It is possible to perform melt sealing with an adhesive disposed at the joint. In addition to the molten resin, a medium such as heat-pressed oil can also be used.

  In addition, the molten resin is subjected to a crosslinking reaction in the mold and is left as it is at the joint of the sheet material to be used as a reinforcing material. Therefore, the mold part where the power generation element for the battery is arranged by applying so-called insert molding technology Is cooled, melt sealing with an adhesive disposed at the joint of the sheet material is performed with a pressurized molten resin, and the joint of the sheet material can be reinforced by molding the resin used for the melting. Therefore, the pressure-heated resin can be used for welding sealing according to the shape and reinforcement that is completely adhered to the sealing portion, and moreover, it can be performed in a continuous process with one mold. is there.

  Further, since the reinforcing material is formed in a frame shape along the peripheral edge of the battery, the sealing of the seam of the sheet material can be easily reinforced over the periphery of the battery.

  Further, the reinforcing material has a shape of an upper and lower frame along the periphery of the battery, and at least a part of the periphery of the battery is formed so as to sandwich the end face of the sheet material. Connected at the sandwiched portion, the joint of the battery sheet material can be reliably suppressed from both sides, and the sealing of the joint can be reliably reinforced.

  Further, since the reinforcing material is formed by integrally connecting the upper and lower frame-shaped materials at the through hole portion at the end of the sheet material at least in the periphery of the battery, the upper frame portion and the lower frame portion are Connected at the connecting portion, the joint of the battery sheet material can be reliably suppressed from both sides, and the sealing of the joint can be reliably reinforced.

  As described above, according to the method for manufacturing a sheet material type battery and the sheet material type battery according to the present invention, it is possible to suppress the welding of the joint of the sheet material, particularly the welding variation in the vicinity of the electrode. Further, it is possible to easily reinforce the sealing of the joint of the sheet material.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Hereinafter, a lithium ion battery will be described as a sheet material type battery. However, any other battery may be used as long as the battery is formed using a sheet material. For example, a nickel metal hydride battery or a capacitor is used as the battery. There may be. Moreover, although the structure of the battery power generation element is described as a structure in which a separator is sandwiched between two electrode bodies and this is wound in a roll shape, a structure in which these are stacked in a flat plate shape may be used. . Further, as a sheet material, a three-layer laminate sheet material of a plastic film, a metal foil, and a plastic film will be described, but the plastic film layer can be appropriately omitted depending on the configuration of the battery. In addition, the material, thickness, and the like of the sheet material and the adhesive disposed at the joint of the sheet material are examples, and other materials and thicknesses may be used.

  In addition, the sheet type battery is used for a vehicle. However, as long as the electrode is drawn out and sealed with a hot-melt adhesive disposed at the joint of the sheet material, It may be used in applications such as home appliances or industrial equipment.

  FIG. 1 is a plan view and a side view of a sheet material type battery 10 that hermetically seals a battery power generation element using a sheet-like laminate material. In the plan view, a part is broken, and the internal structure of the sheet material type battery 10 is shown. The sheet material type battery 10 includes a sheet material case 12 which forms a laminate film to form an outer shape of the battery, a battery power generation element 14 housed in the sheet material case 12, and an electrode body of the battery power generation element 14. The electrode terminal 16 connected and drawn out of the sheet material case 12 is provided, and a frame-shaped reinforcing material 30 formed by resin molding is provided at the peripheral end of the sheet material case 12.

  The battery power generation element 14 housed in the sheet material case 12 is a functional part of the sheet material type battery 10, and will be described first. Next, the battery power generation element 14 and the electrode terminal 16 are hermetically sealed. The sealing structure of the sheet material case 12 including the reinforcing material 30 to be sealed will be described in detail.

The power generation element 14 for a battery is an element that realizes a power generation structure known as a lithium ion battery. The battery power generation element 14 is overlapped by sandwiching a separator between two electrode bodies coated with an active material, and is formed into a roll shape. It is wound and impregnated with an electrolyte. Of the two electrode bodies, one electrode body has an aluminum foil as a base material, and an active material that is a lithium-containing composite compound such as lithium cobalt oxide is applied to the surface of the electrode body, and the other electrode body has a copper foil as a base material Then, an active material such as a carbon material occluded with lithium ions is applied thereon. As the separator, a polymer electrolyte plasticized with a solvent is used. And by inject | pouring electrolyte solution and making it immerse between one electrode body, a separator, and the other electrode body, it comes to show the function as an electric power generation element of a lithium ion battery. As the electrolytic solution, an organic solvent in which a lithium salt such as LiClO ₄ or LiPF ₆ is dissolved is used. In addition to the method of winding two types of electrode bodies and separators in a roll shape, these may be laminated in the form of a sheet.

  The electrode terminal 16 is a conductive terminal connected to each of the two electrode bodies of the battery power generation element 14 and has a function of drawing power from the battery power generation element 14 to the outside. Specifically, in the battery power generation element 14, a positive electrode terminal is connected to the aluminum foil of one electrode body by welding or the like, and a negative electrode terminal is connected to copper of the other electrode body by welding or the like. The thickness of the electrode terminal 16 can be about 1 mm, for example.

  Next, the sealing structure of the sheet material case 12 including the reinforcing material 30 will be described. FIG. 2 is a diagram showing a cross-sectional structure in the vicinity of the electrode terminal 16 along the line AA in FIG. 1 as a typical example of the sealing portion of the sheet material type battery 10.

  The sheet material case 12 is formed by forming the laminate film 20 into a shape that roughly follows the outer shape of the battery power generation element 14, and specifically has two upper and lower surfaces by folding the material of one laminate film 20. Like the sheet, the upper surface sheet is formed with a concave shape that follows the upper surface shape of the battery power generation element 14, and the lower surface sheet is formed with a concave surface shape that follows the lower surface shape of the battery power generation element 14. Molding is performed so that the peripheral edge of the upper surface sheet and the peripheral edge of the lower surface sheet face each other so that the battery power generation element 14 can be disposed between the pair of concave shapes. Then, an appropriate sealing allowance is taken at the joint, and the outer shape is formed by cutting or the like. In this way, the sheet material case 12 before sealing can be obtained. Of course, it is also possible to form a plurality of sheets made of the laminate film 20 so as to have an appropriate concave shape and sealing allowance, and to combine them into the sheet material case 12.

  That is, the sheet material case 12 has a pair of concave portions facing each other at the center thereof, and has a bulge portion 11 that becomes a pair of convex portions in terms of outer shape, and the upper and lower sheets of the laminate film 20 around the bulge portion 11. Is provided with an outer shape having a flange 13 facing each other. The internal space of the bulge portion 11 is a storage space for the battery power generation element 14, and the flange portion 13 is a portion that adheres the upper surface side sheet and the lower surface side sheet of the laminate film 20 to each other and hermetically seals them. As will be described in detail later, this hermetic sealing utilizes heating and pressurization with a molten resin in the mold, and the molten resin used for the hermetic sealing is molded by a crosslinking reaction and directly sealed. The reinforcing material 30 is in close contact with the flange portion 13 and is used for reinforcing the flange portion 13.

  As shown in FIG. 2, the laminate film 20 is formed by laminating a plastic film 22 for surface protection, a metal foil 24 as a gas barrier layer, and a plastic film 26 for internal protection in three layers. Specifically, a polypropylene film having a thickness of about 30 μm, an aluminum foil having a thickness of about 60 μm, and a nylon film having a thickness of about 15 μm can be used. Here, the polypropylene film layer is disposed on the outer surface side of the sheet material case 12 as the plastic film 22 for surface protection, and the nylon film is disposed on the battery power generation element 14 side as the plastic film 26 for internal protection.

  On the nylon film side of the laminate film 20, a layer of a heat-weldable adhesive material 28 is further provided. Specifically, polypropylene having a thickness of about 30 μm can be used. Polypropylene of this thickness melts in about a few seconds by applying a high temperature and high pressure of, for example, 220 ° C. and 50 atm, and is sandwiched between two plastics to be melted together. Can be glued to. The adhesive 28 may be provided over the entire surface of the laminate film 20, but is provided at the joint of the laminate film 20 that performs hermetic sealing at least at the peripheral edge of the sheet material case 12. That is, the adhesive 28 is disposed on the surface of the nylon film, which is the internal protective plastic film 26, around the periphery along the flange 13 of the sheet material case 12.

  In the collar portion 13 of the sheet material case 12, an intervening layer 18 provided in the electrode terminal 16 portion is provided between the electrode terminal 16 which is a metal material and the laminate film 20, and sufficient airtight sealing therebetween is provided. It has a function. In other words, heat-weldable polypropylene is suitable for bonding between plastic materials, but is not sufficient as it is for bonding between metal materials and plastic materials. Therefore, an intervening layer is used to form a structure of metal material-intervening layer 18-adhesive 28-nylon, and the intervening layer 18 and the adhesive 28 are heated and melted, so that a synergistic effect between the metal material and the nylon is obtained. This is to ensure hermetic sealing. The intervening layer 18 is preferably a plastic film that melts under heat and pressure and has good compatibility with the adhesive. Specifically, the intervening layer 18 is disposed using a modified polypropylene so as to surround the base portion of the electrode terminal 16. can do.

  The reinforcing member 30 is a resin member that is formed in a frame shape by being in close contact with the flange portion 13 of the sheet material case 12. The reinforcing material 30 is not prepared by being molded separately from the sheet material case 12 or the like, but the sheet material case 12 containing the battery power generation element 14 is set in an injection mold and a so-called insert molding technique is used. The sheet material case 12 is molded and integrated into a frame shape that is completely adhered along the flange 13. This frame shape is connected to the upper and lower sides at the side surface of the flange portion 13 of the sheet material case 12. That is, it is formed so as to cover the upper and lower surfaces and the side surfaces at the joint of the laminate film 20 that is hermetically sealed at the peripheral edge of the sheet material case 12. That is, the reinforcing material 30 is formed in such a manner as to sandwich the seam of the laminate film 20 protruding around the periphery of the sheet material case 12. As a material of the reinforcing material 30, polypropylene can be used.

  FIG. 3 is a flowchart showing the procedure of the method of manufacturing the sheet material type battery 10 having such a configuration. The procedure of forming the sealing structure of the sheet material type battery 10, that is, the procedure of forming the sealing structure of the sheet material case 12 will be described in detail using this flowchart.

  In the power generation element forming step (S10), as described above, the separator is sandwiched between the two electrode bodies coated with the active material, wound in a roll shape, and the electrolyte is still soaked. This is a step of forming a battery power generation element 14 that is not. The electrode connecting step (S12) is a step of connecting aluminum and copper electrode terminals 16 to the two electrode bodies by welding or the like and pulling them out from the battery power generation element 14 to the outside.

  Next, the step (S14) of setting an adhesive on the sheet material is a step of arranging a heat-welding adhesive on the sheet material case 12 prepared in advance. Thus, the sheet material case 12 was disposed at the joint of the bulge portion 11 for housing the battery power generation element 14, the flange portion 13 for sealing, and at least the flange portion 13 as described above. The heat-meltable adhesive 28 is provided.

  The step (S16) of setting the power generation element or the like is a step of setting the power generation element with electrode terminals on the sheet material case 12 on which the adhesive 18 is set. Prior to this, an intervening layer 18 is provided on the electrode terminal 16. It is done. This process proceeds as follows. First, with the sheet material case 12 open, for example, the lower outer shape of the battery power generation element 14 is inserted into the lower bulge portion 11. At this time, the electrode terminal 16 protrudes to the outside in such a manner that the intervening layer 18 covers the flange 13. Then, the upper bulge portion 11 of the sheet material case 12 is covered so as to match the outer shape of the battery power generation element 14, and the sheet material case 12 is closed.

  This is shown in FIG. Here, the sheet material case 12 is shown in an opened state. In addition, the heat-meltable adhesive 28 is disposed around the periphery of each flange 13 of the sheet material case 12 that is folded up and down. Alternatively, the heat-meltable adhesive 28 is disposed at a position corresponding to the arrangement position of the interposition layer 18 on one side of the upper and lower folded portions, for example, the lower ridge portion 13 and the other side, in this case, the upper ridge portion 13 in this case. You may make it do. Then, the battery power generation element 14 having the electrode terminal 16 around which the intervening layer 18 is wound is a recess in the bulge portion 11 on the lower side of the sheet material case 12 as shown by a white arrow in FIG. Inserted into. Then, the sheet material case 12 is folded back in the direction indicated by the circular arc arrow in FIG. 4, and the upper bulge portion 11 covers the upper side of the battery power generation element 14.

  In this way, the battery power generation element 14 is wrapped with the sheet material case 12 made of the laminate film 20, the both electrode terminals 16 are drawn out from the battery power generation element 14, and the gap between the joints at the ends of the laminate film 20 facing each other. A semi-finished battery can be obtained by sandwiching an adhesive 28 that melts by heating (S18). Semi-finished is because hermetic sealing has not yet been performed and no electrolyte has been injected. Note that S14 and S16 may be switched in order.

  Here, a mold for hermetic sealing will be described. FIG. 5 is a cross-sectional view of a hermetic sealing mold 40 and shows a state where a semi-finished battery is set for convenience of explanation. The mold 40 includes a lower mold 42 and an upper mold 44 that are separated by a partition line 41. And each consists of the center part 46 and the resin molding part 48 of the circumference | surroundings. A molding resin injection port 50 is provided at the resin molding portion 48 of the upper mold 44.

  In the lower mold 42 and the upper mold 44, the central portion 46 has a recess 52 in which a portion corresponding to the battery power generation element 14 of the semi-finished battery is accommodated. However, resin molding is not performed in the central portion 46. The resin molding portion 48 around the central portion 46 has a cavity 54 into which resin is injected from the injection port 50, and the cavity 54 is vertically and laterally along the flange portion 13 of the sheet material case 12 of the semi-finished battery. Provided. The cavity 54 is preferably provided with an auxiliary pin 56 for holding the position of the flange portion 13 of the sheet material case 12.

  As described above, the resin molding is performed only at the resin molding portion 48, but the central portion 46 is water-cooled so that the heat generated by the resin molding does not affect the battery power generation element 14. Specifically, a water cooling pipe (not shown) is provided at the outer periphery or inside the mold in the central portion 46, and cooling water from a cooling device (not shown) is supplied. That is, the mold 40 for hermetic sealing is resin-molded by the resin molding part 48 in the peripheral part, and the temperature of the part becomes high, but the central part 46 is water-cooled, for example, kept at room temperature. .

  Returning again to FIG. 3, the semi-finished battery is placed in a hermetic sealing mold (S20). This is shown in FIGS. FIG. 6 shows a state in which the mold is opened and the semi-finished battery 32 is set in the lower mold 42, and FIG. 7 shows an integrated structure in which the upper mold 44 is aligned thereon and the semi-finished battery 32 is set inside. It is a figure which shows a mode when the injection mold 40 of this is comprised. 5 corresponds to a cross-sectional view taken along the line BB in FIG. As shown in FIG. 6, the resin molding cavity 54 is provided around the collar 13 of the semi-finished battery 32, and as described with reference to FIG. 5, the cavity 54 is the collar of the sheet material case 12. 13 along the top and bottom and side surfaces. Therefore, the shape after the resin molding is a frame shape in which the collar portion 13 of the semi-finished battery 32 is completely adhered and sandwiched.

  And the center part 46 of the metal mold | die 40 is cooled (S22). As described above, water cooling is used for cooling, for example, cooling water having a water temperature of 20 ° C. is supplied. Either S20 or S22 may be performed first. Then, resin injection is performed (S24). Specifically, molten resin is injected into the injection port 50 from a resin source (not shown) and pressurized. If necessary, the resin molding portion 48 is controlled to a temperature suitable for molding. Polypropylene is used as the molten resin. The resin injection amount, pressurization, temperature, and other sequences for this resin molding are executed under the control of an injection molding control unit (not shown). For example, the molten resin temperature can be 220 ° C., the pressure can be 50 atm, the injection time can be 5 seconds, and the pressure time including the injection time can be 15 seconds.

  Then, since the molten resin is pressure-filled into the cavity 54 of the mold 40, the heat-melt adhesive 28 disposed between the seams of the laminate film 20 is formed in the collar portion 13 of the semifinished battery 32. It is heated and pressurized by the molten resin, melted, and the seam of the laminate film 20 is bonded. More specifically, at the joint of the laminate film 20 without the electrode terminal 16, the upper and lower laminate films 20 are bonded together by the adhesive 18, and the laminate film 20 having the intervening layer 18 disposed around the electrode terminal 16 is provided. At the joint, the electrode terminal 16 and the upper and lower laminate films 20 are bonded by the intervening layer 18 and the adhesive 28.

  Since the pressurized molten resin is a heated and pressurized fluid, the laminated film 20 and the intervening layer follow the thickness and shape of the electrode terminal 16 even in the portion of the laminated film 20 that sandwiches a hard substance such as the electrode terminal 16. 18, the laminate of the adhesive 28 is pressed, and the intervening layer 18 and the adhesive 28 are melted so as to follow the thickness and shape of the electrode terminal 16. Therefore, after bonding, the electrode terminal 16 can have a smooth shape following the thickness and shape.

  In this way, the adhesive 28 can be melted by the melt-pressed polypropylene that is a pressurized heating fluid, and the flange 13 of the semi-finished battery 32 can be sealed by bonding. Then, by molding the melt-pressed polypropylene in the mold 40 by a cross-linking reaction, the upper and lower side surfaces of the flange portion 13 can be sandwiched completely with resin (S26). If the bonding / clamping is sufficiently performed, the mold is removed from the mold 40 to remove the battery that has been bonded / clamped (S28). The battery that has been removed from the mold has the same external shape as that shown in FIG.

  Next, electrolyte injection is performed (S30). The electrolyte solution injection is performed by providing an injection hole communicating with the bulge portion 11 of the sheet material case 12. FIG. 8 is a diagram showing the situation. A hole 34 is formed in the bulging portion 11 so as to communicate with the folded portion of the upper and lower sheets of the sheet material case 12 in the battery 34 that is hermetically sealed and immediately before completion of electrolytic injection. The injection hole 36 is in communication. Then, a predetermined electrolytic solution is injected from the external electrolytic solution injector 38 into the battery power generation element 14 through the injection hole 36. After the electrolyte injection is finished, the injection hole 36 is tightly sealed. Thus, the sheet material type battery shown in FIG. 1 is completed (S32).

  In this way, the portion of the battery power generation element that is normally required to be kept at 80 ° C. or lower is cooled, and the resin is molded at the collar portion that is the joint of the peripheral edge portion of the sheet material case, so that the molten resin The reinforcing material can be sealed by being subjected to a crosslinking reaction as it is, and can be completely adhered to the heel part. Then, since sealing is performed using a molten resin that is a heated and pressurized fluid, the laminate film is pressed in accordance with the shape even when there is a change in the shape or a step such as the electrode terminal. Since the hot-melt adhesive material is melted and bonded in the meantime, variations in welding strength and the like can be reduced, and the shape can be smoothly bonded.

  FIG. 9 is a plan view and a side view of the sheet material type battery 60 in which the arrangement of the reinforcing material is changed. In the plan view, like FIG. 1, a part thereof is broken to show the internal structure of the sheet material type battery 60. In the sheet material type battery 60, the arrangement and shape of the reinforcing material 62 are different from those of the sheet material type battery 10 described in FIG. Since the other elements are the same as those in FIG. 1, the same elements are denoted by the same reference numerals and detailed description thereof is omitted. The reinforcing material 62 of the sheet material type battery 60 has a frame shape. Of the four sides of the flange portion 13 of the sheet material case 12, the two sides from which the electrode terminal 16 is drawn out and the two sides orthogonal to the two sides As for one side, like the reinforcing material 30 of the sheet material type battery 10 of FIG. 1, the upper and lower sides and the side surfaces of the flange 13 are surrounded, so to speak. As for the other side of the collar part 13, the frame-shaped parts are arranged above and below, but are not arranged on the side surface of the collar part 13 and do not sandwich the collar part 13. By setting it as such a structure, it can be set as the smaller sheet material type battery 60. FIG.

  The purpose of the reinforcing material to sandwich the collar 13 is to reinforce the seam to which the collar 13 is bonded, to improve waterproofness, and to prevent the seam from being peeled off. Therefore, when the reinforcing material is disposed along the flange portion 13, it is possible to press down the entire periphery of the flange portion 13 even if the reinforcing material is not connected to the upper and lower sides of the reinforcing material on all four sides. FIG. 9 shows an example in which the top and bottom of the reinforcing material 62 are not connected on one side.

  FIG. 10 is a diagram schematically showing the state of assembling the sheet material type battery 60 having the structure of FIG. A battery power generation element 14 with electrode terminals is housed in a sheet material case 12 having a bulge portion 11 and flange portions 13a and 13b, and the sheet material case 12 is closed in the direction of the broken arrow in FIG. A battery is obtained. The process so far is the same as that of the sheet material type battery 10 of FIG. 1, but the following hermetic sealing mold is different. As shown in FIG. 10, when the collar portion 13 is distinguished from the folded-back flange portion 13a of the laminate film and the opposite-side flange portion 13b, the hermetic sealing mold is formed of a resin for the folded-back flange portion 13a. All of the inside of the molding cavity is included, and for the flange portion 13b on the opposite side, only the tip portion of the flange portion 13b is not included in the resin molding cavity. Since the hot-melt adhesive is disposed over the entire circumference of the flange 13, sealing with the pressurized molten resin is performed over the entire circumference of the flange 13, but the reinforcing material 62 is opposite to the folded side. The side surface of the flange 13b is not covered.

  FIG. 11 is a plan view and a side view of a sheet material type battery 70 having a reinforcing material of another arrangement and shape. In the plan view and the side view, a part is broken, and the internal structure of the sheet material type battery 60 is shown. In this sheet material type battery 70, the arrangement and shape of the reinforcing material 72 are different from those of the sheet material type battery 10 described in FIG. Since the other elements are the same as those in FIG. 1, the same elements are denoted by the same reference numerals and detailed description thereof is omitted.

  The reinforcing material 72 of the sheet material type battery 70 has a frame shape, but the planar outer shape thereof is smaller than the planar outer shape of the flange portion 13 of the sheet material case 12. That is, the frame shape of the reinforcing member 72 is disposed on the upper surface and the lower surface of the flange portion 13 of the sheet material case 12, but does not cover the side surface of the flange portion 13 and does not sandwich the tip of the flange portion 13. Instead, through holes are provided at four locations on the flange 13, and connection portions 74 to which the upper and lower frame-shaped members are connected are provided. By this connection portion 74, the upper and lower frame-shaped material can firmly press the flange portion 13 over the entire circumference. By setting it as such a structure, it can be set as the still smaller sheet material type battery 60. FIG.

  The connecting portion 74 is provided with a plurality of through holes at an appropriate arrangement interval within a range in which the reinforcing member 72 of the flange portion 13 of the sheet material case 12 is arranged, so that the resin is inserted into the through holes at the time of resin molding. Flows in and the upper and lower frame-shaped portions can be integrated. In FIG. 11, the connection portions 74 are arranged at the four corners of the collar portion 13, but other arrangements may be used.

  In each of the sheet material type batteries 10, 60, and 70, the meltable adhesive disposed at the joint of the laminate film is melted and sealed with a molten resin that is a heating and pressurizing fluid, and directly subjected to a crosslinking reaction. A reinforcing material is formed. When the melt seal has sufficient strength, the heated and pressurized fluid may be discharged at the sealing stage. As the heat-pressurized fluid for sealing, a heat-pressurized oil or the like in the mold can be used in addition to the molten resin in the mold.

  FIG. 12 is an external view of a sheet material type battery 80 that does not use a reinforcing material. This sheet material type battery 80 has an adhesive 82 melted at the joint of the flange portion 13 of the sheet material case 12, and at first glance resembles that by a conventional sealing method using a hot press plate or the like. One of the differences is the sealed state around the electrode terminal 16. In the case of using a heat-pressed jig having a fixed shape such as a heat-pressed plate, a mechanical pressing mark remains in the sealing shape around the electrode terminal 16 and a smooth sealing shape is often not obtained. Further, since the shape of the electrode terminal 16 varies while the shape of the jig is constant, the shape and size of welding between the electrode terminal 16 and the sheet material case 12 are not constant. On the other hand, in the method of sealing using a heated and pressurized fluid, the laminate film is pressed in accordance with the shape and dimension of the electrode terminal 16 and the meltable resin is melted. Even if the shape and size of the terminal 16 vary, the welding shape and size between the electrode terminal 16 and the sheet material case 12 do not vary, and sealing is performed in a smooth shape.

  The second difference is the state of the molten adhesive material 82. The adhesive 82 melts at the heated and pressurized fluid portion in the mold cavity. The mold is not in close contact with the melted portion. In a conventional heating press, a heating press plate or the like is in close contact with the melted portion. Therefore, there is a difference between whether the adhesion portion of the mechanical element is outside or inside the molten adhesive material 82. That is, the mechanical pressing mark remains on the inner side of the molten adhesive material 82 in the conventional technique, and in the example of FIG. By such observation, it is possible to distinguish between sealing by a conventional technique and sealing by a heated and pressurized fluid shown in FIG.

It is the top view and side view of a sheet material type battery in an embodiment according to the present invention. It is a figure which shows the cross-section of the electrode terminal vicinity along the AA line of FIG. It is a flowchart which shows the procedure about the manufacturing method of the sheet material type battery in embodiment which concerns on this invention. It is a figure which shows the mode of the process of setting an electric power generation element etc. for manufacture of the sheet material type battery in embodiment which concerns on this invention. In embodiment which concerns on this invention, it is sectional drawing of the metal mold | die for airtight sealing in which the semi-finished battery was set. It is a figure which shows the mode of the process of setting a semi-finished battery to a lower metal mold | die for manufacture of the sheet material type battery in embodiment which concerns on this invention. The figure which shows a mode that a semi-finished battery is set inside for the manufacture of the sheet material type battery in embodiment which concerns on this invention, an upper mold is match | combined with a lower mold, and an integral injection mold is comprised. It is. It is a figure which shows the mode of the process by which electrolyte solution injection | pouring is performed for manufacture of the sheet material type battery in embodiment which concerns on this invention. It is the top view and side view of a sheet material type battery in other embodiments. It is a figure which shows typically the mode of the assembly in the sheet material type battery of the structure of FIG. It is the top view and side view of the sheet material type battery in other embodiment. It is an external view of the sheet material type battery in another embodiment.

Explanation of symbols

  10, 60, 70, 80 Sheet material type battery, 11 Swelling part, 12 Sheet material case, 13, 13a, 13b collar part, 14 Power generation element for battery, 16 Electrode terminal, 18 Intervening layer, 20 Laminate film, 22, 26 Plastic film, 24 Metal foil, 28, 82 Adhesive, 30, 62, 72 Reinforcing material, 32 Semi-finished battery, 34 Battery just before completion, 36 Injection hole, 38 Electrolyte injector, 40 Mold, 41 Partition line, 42 Lower mold, 44 Upper mold, 46 Center part, 48 Resin molding part, 50 Inlet, 52 Recess, 54 Cavity, 56 Auxiliary pin, 74 Connection part.

Claims (7)

A process of forming a semi-finished battery by wrapping a battery power generation element with a sheet material, pulling out both electrodes from the battery power generation element to the outside, and sandwiching an adhesive that melts by heating between the joints of the ends facing the sheet material When,
Place the semi-finished battery in a hermetic sealing mold, cool the mold part where the battery power generation element is placed, and apply heated and pressurized fluid only to the edge of the sheet material of the semi-finished battery. , The step of melting and sealing hermetically the adhesive at the end of the sheet material;
A sheet material type battery manufacturing method comprising: In the manufacturing method of the sheet material type battery according to claim 1,
The method for producing a sheet material type battery, wherein the heated and pressurized fluid is a molten resin pressurized in a mold. In the manufacturing method of the sheet material type battery according to claim 2,
A method for producing a sheet material type battery, comprising a step of forming a molten resin in which an end portion of a sheet material is subjected to a crosslinking reaction in a mold as a battery reinforcing material. In the manufacturing method of the sheet material type battery according to claim 3,
A method for manufacturing a sheet material type battery, wherein the battery reinforcing material is formed into a frame shape along a hermetic sealing end portion around the battery. In the manufacturing method of the sheet material type battery according to claim 4,
The reinforcing material is formed into a frame shape on each of the upper and lower surfaces of the end portion of the sheet material along the periphery of the battery, and further covers the side surface together with the upper and lower surfaces of the end portion of the sheet material in at least a part of the periphery of the battery. A method for manufacturing a sheet material type battery, wherein the battery is molded so as to sandwich a material end face. In the manufacturing method of the sheet material type battery according to claim 4,
The reinforcing material is formed into a frame shape on each of the upper and lower surfaces of the end portion of the sheet material along the periphery of the battery. Further, at least part of the periphery of the battery, the upper and lower frame shape material is formed at the through hole portion at the end of the sheet material A method for manufacturing a sheet material type battery, wherein the two are integrally connected and molded. In a battery that encloses a battery power generation element with a sheet material, draws both electrodes from the battery power generation element to the outside, and hermetically seals and stores the opposite ends of the sheet material,
A frame shape is formed on each of the upper and lower surfaces of the sheet material edge along the periphery of the battery, and the upper and lower frame shape materials are connected together at the through-hole portion of the sheet material edge at least in the periphery of the battery. And a resin-molded reinforcing material,
An adhesive disposed between the joints of the sheet material ends sandwiched by the resin-molded reinforcing material, and melted by heating of the resin molding; and
A sheet material type battery characterized in that an end portion of the sheet material is hermetically sealed with a molten adhesive material.

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