JP2012199202A - Battery and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery and a manufacturing method thereof which, when sealing a liquid injection port by joining a sealing member to a liquid injection port member forming a liquid injection port, can obtain a desired joining width stably and also can reduce failure for efficient production.SOLUTION: Used as a liquid injection member is the one which is formed with laser light absorbing resin and has a joining face formed thereon enclosing a liquid injection port on the outer surface side, with an annular protrusion formed on the joining face enclosing the liquid injection port. Then, after liquid injection, a sealing member formed with laser light transmitting resin is placed on top of the protrusion, and laser light is irradiated on the protrusion from above the sealing member. This causes the protrusion and its periphery to be melted, whereby the sealing member is contacted with and joined to the joining face.

Description

  The present invention relates to a battery and a battery manufacturing method. More specifically, the present invention relates to a battery in which an injection port into which an electrolytic solution is injected in the manufacturing process is sealed with a sealing member, and a method for manufacturing the battery.

  Batteries are used in various fields as power sources for electronic devices such as mobile phones and laptop computers, and as power sources for vehicles such as hybrid cars and electric cars. The batteries include nickel / cadmium batteries, nickel / hydrogen batteries, and lithium ion secondary batteries.

  A battery is manufactured through various manufacturing processes. For example, in the manufacturing process of a lithium ion secondary battery, in general, a power generation element manufacturing process is performed in which a positive electrode plate and a negative electrode plate are manufactured, and a power generation element is formed by winding or stacking a separator between them. And a battery assembly process in which the power generation element is housed in the main body case and the case opening is covered, and an electrolyte solution injection process in which the electrolyte solution is injected into the case.

  In the electrolytic solution injection step, the electrolytic solution is injected into the case from the injection port provided in the case, and then the injection port is sealed. As a method for sealing the liquid injection port, the applicant previously bonded a sealing member for sealing the liquid injection port to the liquid injection member forming the liquid injection port using laser light. Has proposed a method for sealing a liquid injection port (Patent Document 1).

  Here, in patent document 1, what was formed with the laser beam absorptive resin was used as the injection member, and what was formed with the laser beam transmission resin was used as the sealing member. In addition, the injection port member is formed with a joint surface surrounding the injection port on the outer surface side, and the sealing member is formed with a protrusion at a position corresponding to the joint surface of the injection port member. . And the protrusion part of a sealing member is comprised so that the non-protrusion part of a sealing member and the joint surface of a liquid inlet member may contact | abut by irradiating a laser beam and making it melt | dissolve a predetermined amount. By doing in this way, it is supposed that the poor welding at the time of sealing a pouring mouth can be reduced.

JP 2009-048663 A

  However, in patent document 1, there existed the following problems by forming a protrusion in the sealing member which is a laser beam transmitting resin.

  For example, the bonding strength between the liquid inlet member and the sealing member cannot be stably obtained. Here, it is known that the bonding strength generally increases as the bonding width increases. However, in general, the inspection of the bonding strength is performed by the destructive test, and the inspection of the bonding width is performed by observing the cross section. Therefore, in order to stably obtain the bonding strength, it becomes an issue to establish a manufacturing method that can stably obtain the target bonding width.

  By the way, in Patent Document 1, it is a laser light transmissive resin that forms a protrusion to be melted. In order to melt the protrusion formed of the laser light transmitting resin, the protrusion is in contact with a liquid injection member that is a laser light absorbing resin that generates heat when irradiated with laser light. It is preferable. This is to efficiently transmit the heat generated by the laser light absorbing resin to the protrusions that are the laser light transmitting resin. However, the mating surface is not necessarily flat, and there may be a gap in the irradiated portion of the laser beam. In this case, there was a possibility that melting failure occurred and the target joining width could not be obtained.

  In addition, in order to melt and bond even a portion having a gap, it is necessary to increase the output of the laser beam and extend the irradiation time, which deteriorates the production efficiency. Furthermore, there has been a risk of damaging the sealing member, such as burning or puncturing, by applying more energy than necessary to the sealing member.

  The present invention has been made for the purpose of solving the problems of the prior art described above. That is, the problem is that when the liquid injection port is sealed by bonding the sealing member to the liquid injection member forming the liquid injection port, the target bonding width can be stably obtained. Furthermore, it is to provide a battery that can reduce defects and can be efficiently produced, and a method for manufacturing the battery.

  The battery of the present invention, which has been made for the purpose of solving this problem, is a battery in which a liquid injection port of a battery case containing a power generation element and an electrolytic solution is closed with a sealing member, and a liquid injection port is formed. The liquid port member is formed of a first type resin that absorbs laser light, and the sealing member is formed of a second type resin having an absorption rate of laser light lower than that of the first type resin; The liquid inlet member and the sealing member have an annular joint at the contact point that surrounds the liquid inlet on the outer surface side, and that the joint bites into the sealing member more than the liquid inlet member. The battery is characterized.

  The battery manufacturing method of the present invention is a method for manufacturing a battery by closing a liquid injection port of a battery case containing a power generation element and an electrolyte with a sealing member. The portion is formed of a first type resin that absorbs laser light, and a joint surface is formed surrounding the liquid injection port on the outer surface side. Further, an annular protrusion surrounds the liquid injection port on the joint surface. After injection, a sealing member made of a second type resin whose laser light absorption rate is lower than that of the first type resin is placed on the projection after injection, and sealed. A battery characterized in that a sealing member is brought into contact with and joined to a joint surface by melting the projection and its periphery by irradiating the projection with a laser beam through the sealing member from above the member. It is a manufacturing method.

  In the present invention, when the sealing member is placed on the protruding portion, a gap corresponding to the height of the protruding portion exists between the sealing member and the bonding surface. In this state, a laser beam is irradiated on the protrusion from above the sealing member. Here, the protrusion is formed of a first type of resin that absorbs laser light, and the sealing member is formed of a second type of resin that has a laser light absorption rate lower than that of the first type of resin. For this reason, the laser light is transmitted through the sealing member and absorbed by the protrusions to generate heat and melt the protrusions and the periphery thereof. And while a projection part and its circumference | surroundings melt | dissolve, a sealing member sinks and contacts a joint surface.

  It can be estimated that the bonding width obtained in this way is equal to or greater than the width of the protrusion without observing the cross section. This is because a part of the melted portion between the protruding portion and the sealing member flows into the gap that existed before the laser light irradiation and then hardens. Moreover, it can be estimated that the melting was properly performed by confirming that the sealing member was submerged and contacted the joint surface. Therefore, it can be estimated that the target joining width was obtained by managing the shape of the protrusion, irradiating the laser beam, and confirming that the sealing member and the joining surface were in contact. Therefore, the target joining width can be obtained stably. In addition, the battery of the present invention manufactured in this way has a joint portion that has a shape that bites more into the sealing member side than the liquid inlet member side.

  In the present invention, the protrusion is formed of a resin that absorbs laser light. In other words, the object to be melted is directly heated. Therefore, it is possible to reduce melting defects and to reduce the amount of laser light irradiation required for melting the protrusions. Therefore, it is an efficient manufacturing method for reducing defects such as damage to the sealing member, reducing the output of laser light, and shortening the irradiation time.

  In the battery manufacturing method described above, the protrusion may have a shape that becomes narrower as the distance from the bonding surface increases. In other words, the protrusion has a shape that becomes thinner toward the tip. Therefore, the protrusion can be easily melted at the initial stage, and the output of the laser beam can be reduced and the irradiation time can be shortened. In addition, by reducing the tip of the protrusion, the contact area with the sealing member is reduced. Therefore, the applied pressure can be reduced, and deformation of the liquid injection member and the sealing member can be reduced.

  Further, in the battery manufacturing method described above, a groove having a shape corresponding to the protruding portion is formed as a sealing member at a position corresponding to the protruding portion when placed on the protruding portion. May be used. This is because it can also serve as alignment when the sealing member is placed on the protrusion. Therefore, when the sealing member is placed on the protrusion, the positioning can be facilitated.

  Further, in the battery manufacturing method described above, when the projection is irradiated with the laser beam, it is continuously irradiated in a ring shape along the projection, and then returned to the irradiation start position, and further along the projection. Irradiation may be continued. Since the heat generation of the protrusions starts when the laser beam irradiation is started, the protrusions near the irradiation start position are not sufficiently heated and may cause poor melting. Therefore, the projection near the irradiation start position is irradiated with the laser beam more than the portion other than that portion, so that defective melting can be reduced.

  In the battery manufacturing method described above, when the projection is irradiated with the laser beam, the projection may be irradiated simultaneously and uniformly. By simultaneously and uniformly irradiating the projections with the laser beam, there is no irradiation start position, and there is no possibility of poor melting in the vicinity. Moreover, when compared locally in the protrusion, the melting is simultaneous. Therefore, the sealing member can be submerged without substantially tilting, and poor bonding can be reduced.

  According to the present invention, when the liquid injection port is sealed by bonding the sealing member to the liquid injection port member that forms the liquid injection port, the target bonding width can be stably obtained. , Batteries that reduce defects and are efficiently produced and methods for manufacturing the batteries are provided.

It is a fragmentary sectional view of the battery concerning the present invention. It is a figure which shows the irradiation part of a laser beam. It is sectional drawing before sealing of the liquid injection port vicinity for demonstrating the liquid injection port sealing method of a 1st form. FIG. 5 is a cross-sectional view of the vicinity of the liquid injection port after sealing of the liquid injection port. It is sectional drawing before sealing of the liquid injection inlet vicinity for demonstrating the liquid injection hole sealing method of a 2nd form. It is sectional drawing before sealing of the liquid injection port vicinity for demonstrating the liquid injection port sealing method of a 3rd form.

[First embodiment]
[Overall schematic configuration]
DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the best mode for embodying the present invention will be described in detail with reference to the drawings. This embodiment embodies the present invention for a lithium ion secondary battery. FIG. 1 shows a battery 1 according to this embodiment. The battery 1 is a flat type lithium ion secondary battery. The battery 1 includes a power generation element 30, an electrolytic solution 40 made of an organic solvent in which a lithium salt is dissolved, and the power generation element 30 and the electrolytic solution 40 contained in a battery case 50. The battery case 50 includes a battery case main body 51 and a case lid 52. Further, the battery case main body 51 and the case lid 52 are made of metal.

  The power generation element 30 is a wound type formed by winding a strip-shaped separator between the strip-shaped positive electrode plate 10 and the strip-shaped negative electrode plate 20 with a narrower width than the positive electrode plate 10 and the negative electrode plate 20. It is a power generation element. The positive electrode plate 10 is connected to the positive electrode terminal 11 inside the battery case 50. The negative electrode plate 20 is connected to the negative electrode terminal 21 inside the battery case 50.

  The power generation element 30 to which the positive electrode terminal 11 and the negative electrode terminal 21 are connected is housed inside the battery case body 51 through the opening, and the opening is closed by assembling the case lid 52. Further, the positive electrode terminal 11 and the negative electrode terminal 21 have their ends not connected to the electrode plate protruding outside the battery case 50 via an insulating member 53 provided on the case lid 52.

  By the way, as shown in FIG. 1, the case lid 52 includes a liquid inlet member 60 that forms a liquid inlet 61. The liquid injection port 61 is for injecting the electrolytic solution 40 into the battery case 50. Here, the electrolytic solution 40 is obtained by dissolving a lithium salt in an organic solvent.

Examples of the organic solvent used in the electrolytic solution 40 include ester solvents such as polypyrene carbonate (PC), ethylene carbonate (EC), dimethyl carbonate (DMC), and ethyl methyl carbonate (EMC), and γ- The thing which mix | blended ether type solvents, such as butylactone ((gamma) -BL) and diethoxytan (DEE), is illustrated. Examples of the lithium salt include lithium perchlorate (LiClO ₄ ), lithium borofluoride (LiBF ₄ ), and lithium hexafluorophosphate (LiPF ₆ ).

  The electrolytic solution 40 is injected by producing the power generation element 30, connecting the electrode terminal to the power generation element 30, housing the power generation element 30 inside the battery case body 51, and attaching the case lid 52. Later. Furthermore, after injecting the electrolytic solution 40, the liquid injection port 61 is sealed with the sealing cap 70.

[Liquid inlet sealing method]
The injection port sealing method of this embodiment will be described. FIG. 3 is a cross-sectional view of the vicinity of the liquid injection port 61 in this embodiment before sealing. The sealing cap 70 is a member for sealing the liquid injection port 61. Further, the sealing cap 70 has a circular shape when viewed from above in FIG.

  The liquid inlet member 60 is a member forming the liquid inlet 61. The case lid 52 and the liquid inlet member 60 are joined by a known welding technique. The liquid injection port member 60 is formed with an annular joint surface 62 that surrounds the liquid injection port 61 on the outer surface side, and an annular continuous protrusion 63 is formed on the joint surface 62. It is enclosed. The protrusion 63 is formed at a position where the joint surface 62 exists both inside and outside. Further, the liquid injection port 61 and the protrusion 63 of the liquid injection member 60 are circular when viewed from above in FIG.

  And as shown in FIG. 3, the sealing cap 70 is mounted on the liquid injection hole member 60, and the protection member 90 is arrange | positioned on it. Therefore, the tip of the protruding portion 63 is in contact with the lower surface of the sealing cap 70, and a gap corresponding to the height of the protruding portion 63 is formed between the lower surface of the sealing cap 70 and the bonding surface 62. Existing. The protective member 90 is a member that contributes only when the liquid injection port 61 is sealed, and is removed after sealing.

  The sealing cap 70 is formed of a laser light transmitting resin having a high transmittance with respect to the laser light. The laser light transmissive resin that can be used for the sealing cap 70 is not particularly limited as long as it is a resin that transmits laser light, has thermoplasticity, does not transmit the electrolytic solution 40, and has resistance. Examples of such a resin include polyphenylene sulfide (PPS), polybutylene terephthalate (PBT), polyethylene (PE), and polypropylene (PP). In this embodiment, PPS is used.

  Unlike the sealing cap 70, the liquid inlet member 60 is formed of a laser light absorbing resin having a high absorption rate with respect to the laser light. The laser light absorbing resin that can be used for the liquid filling member 60 is not particularly limited as long as it is a resin that absorbs laser light, has thermoplasticity, and does not transmit the electrolytic solution 40 and has resistance. Examples of such a resin include those obtained by blending and coloring carbon black (C / B), a dye, or the like to the resin exemplified in the sealing cap 70. In this embodiment, PPS blended with C / B is used.

  Further, in this embodiment, the same PPS is used for the sealing cap 70 and the liquid inlet member 60, but different resins may be used in consideration of the bonding strength and the properties required for each component.

  FIG. 2 is a view of FIG. 3 as viewed from above, in which the protective member 90 is omitted. Here, the irradiation part I shows the part irradiated with the laser beam, and is a virtual line.

  The laser beam used in the present embodiment is not particularly limited as long as it can pass through the sealing cap 70 and be absorbed by the liquid inlet member 60. Examples of such laser light include semiconductor lasers, YAG lasers, dye lasers, helium-neon lasers, and excimer lasers. In this embodiment, a semiconductor laser is used.

  In FIG. 3, A indicates the protrusion width A that is the width of the protrusion 63, and L indicates the irradiation diameter L that is the beam diameter when the irradiated laser light reaches the protrusion 63. In the relationship between the protrusion width A and the irradiation diameter L, the protrusion width A is preferably larger than the irradiation diameter L. This is because the protrusion width A is larger than the irradiation diameter L, so that only the protrusion 63 can be irradiated with laser light.

  In FIG. 3, B indicates a protrusion height B that is the height of the protrusion 63. That is, the protrusion height B is the size of the gap existing between the lower surface of the sealing cap 70 and the bonding surface 62. C indicates an inner width C that is a length from the inner edge of the joint surface 62 to the inner diameter of the protrusion 63. The inner width C is preferably larger than the protrusion height B. This is to prevent a part of the melted portion from reaching the inner edge of the joining surface 62 and entering the inside of the battery case 50 from the liquid injection port 61 when the projection 63 is melted by irradiating the laser beam. is there.

  In FIG. 3, D indicates an outer width D that is a length from the outer diameter of the protrusion 63 to the outer edge of the joint surface 62. E indicates an outer width E that is a length from the outer diameter of the protrusion 63 to the outer edge of the lower surface of the sealing cap 70. Here, the outer width D and the outer width E are preferably larger than the projection height B. This is to prevent a part of the melted portion from flowing out from the outer edge of the lower surface of the joint surface 62 and the sealing cap 70 when the projection 63 is melted by irradiating the laser beam.

  The protective member 90 is preferably made of a material that transmits laser light, and glass is used in this embodiment. In FIG. 3, a pressing force is applied from above the protection member 90. Therefore, the pressure applied from above the protective member 90 is applied to the contact portion between the sealing cap 70 and the protrusion 63.

  Thus, in this embodiment, laser light is irradiated from the upper part of the sealing cap 70 while applying pressure to the contact portion between the sealing cap 70 and the protrusion 63. In this embodiment, the irradiation head that irradiates the laser beam is equipped with, for example, a galvano scanner. Therefore, the irradiation position of the laser beam can be controlled.

  In the laser beam irradiation method of this embodiment, the laser beam is continuously irradiated in a circular manner as shown by the irradiation unit I, starting from a predetermined position of the irradiation unit I. That is, the laser beam is irradiated once along the protrusion 63. In the laser beam irradiation method of this embodiment, the laser beam is irradiated from the predetermined position of the irradiation unit I as a starting point, and continuously irradiated in a circular manner as indicated by the irradiation unit I, and then the laser beam exceeds the starting point. Irradiate. That is, the irradiation part I has a wrap part having a predetermined length. The lap portion is for eliminating the poor melting of the protrusion 63 in the vicinity of the starting point.

  The protrusion 63 starts to generate heat when the irradiation of the laser beam is started. That is, the heat generation of the protrusion 63 is insufficient for a while from the starting point where the irradiation of the laser beam is started. Therefore, in order to make up for the lack of heat generation at this point, the laser beam is irradiated repeatedly. That is, the laser beam is irradiated twice at the lap portion of the protrusion 63.

  The irradiated laser light passes through the protective member 90 and the sealing cap 70, reaches the contact point between the sealing cap 70 and the protruding portion 63, and is absorbed by the protruding portion 63. Therefore, the protrusion 63 melts by absorbing the laser beam and generating heat. At this time, the vicinity of the contact portion of the sealing cap 70 with the protrusion 63 is also melted by the heat generated by the protrusion 63. Therefore, the melted portion of the protrusion 63 and the sealing cap 70 becomes a melted portion in which the respective resins are mixed. The sealing cap 70 sinks while the protrusion 63 and the sealing cap 70 are melted and a part of the melted portion is pushed into the gap by the applied pressure.

  Here, the output and the irradiation time of the laser beam are set so that the sealing cap 70 sinks by the projection height B when the laser beam finishes irradiating the irradiation portion I one turn and the lap portion. . That is, when the irradiation with the laser beam is completed, the sealing cap 70 and the bonding surface 62 come into contact with each other. Thereafter, the molten part is cured by being cooled, for example, by being left standing, and the liquid injection member 60 and the sealing cap 70 are joined.

  FIG. 4 shows a cross section in which the joining of the liquid inlet member 60 and the sealing cap 70 is completed. That is, FIG. 4 is a cross-sectional view of the vicinity of the liquid injection port 61 that is irradiated with the laser beam in FIG. Therefore, as shown in FIG. 4, there is no gap corresponding to the protrusion height B that existed before the laser beam irradiation.

  Also, the joint 80 shown in FIG. 4 is obtained by curing the melted portion between the projection 63 and the sealing cap 70. The cross-sectional shape of the joint 80 is not vertically symmetric with respect to the contact surface between the sealing cap 70 and the joint surface 62. The cross-sectional shape of the joining portion 80 is a shape that is deeply cut into the sealing cap 70 side than the liquid injection port member 60 side. This indicates that, due to the heat generated by the protrusion 63, the protrusion 63 is melted, and the vicinity of the root of the protrusion 63 is also slightly melted. At the same time, it is shown that the vicinity of the contact portion of the sealing cap 70 with the protrusion 63 is melted more greatly than the vicinity of the root of the protrusion 63.

  In FIG. 4, J indicates a bonding width J that is the width of the bonding portion 80. Here, if the sealing cap 70 is made of a resin that transmits visible light, the bonding width J should be confirmed with the naked eye through the sealing cap 70 to see if the target width is obtained. Can do. This is because the joint 80 is obtained by melting the liquid injection member 60 and the sealing cap 70 and curing the melted portion in which the respective resins are mixed.

  Moreover, even if the sealing width | variety J is resin which does not permeate | transmit visible light, it can be estimated that the junction width J is more than the protrusion width A. The joining width J is melted while pressurizing the liquid injection member 60 and the sealing cap 70, so that a part of the melted portion is pushed into the gap that existed before the laser beam irradiation and then cured. Because it is a thing.

  Therefore, it can be estimated that the bonding width J in this embodiment is not less than the protrusion width A without performing cross-sectional observation. Moreover, it can be estimated that the melting was performed appropriately by irradiating the laser beam, confirming that the sealing cap 70 was sunk and the sealing cap 70 and the bonding surface 62 were in contact with each other. That is, it can be estimated that the target joining width J is obtained by managing the shape of the protrusion 63, irradiating the laser beam, and confirming that the sealing cap 70 and the joining surface 62 are in contact with each other. It is. Therefore, the target joining width J can be obtained stably.

  In this embodiment, the laser beam is irradiated to the protrusion 63 formed of a resin that absorbs the laser beam. In other words, the object to be melted is directly heated. Therefore, it is possible to reduce melting defects and to reduce the irradiation amount of the laser light necessary for melting the protrusions 63. Therefore, it is an efficient manufacturing method for reducing defects such as damage to the sealing cap 70, reducing the output of laser light, and shortening the irradiation time.

[Second form]
The second embodiment will be described. The configuration of the battery 1 according to this embodiment is the same as that of the first embodiment. The difference between the first embodiment and the present embodiment is the shape of the protruding portion of the liquid inlet member. That is, the cross-sectional shape of the protrusion in this embodiment is a triangular shape.

  FIG. 5 is a cross-sectional view of the vicinity of the liquid injection port 161 in the present embodiment before sealing. Also in this embodiment, the conditions of the projection height B, the inner width C, the outer width D, and the outer width E are the same as those in the first embodiment. However, with respect to the protrusion width A, in this embodiment, since the cross-sectional shape of the protrusion 163 is triangular, the base of the protrusion width A is the protrusion width A. Also in this embodiment, it is preferable that the protrusion width A is larger than the irradiation diameter L in the relationship between the protrusion width A and the irradiation diameter L. However, the tip of the protrusion 163 is smaller than the irradiation diameter L of the laser beam.

  Therefore, the protrusion 163 of this embodiment is easily melted at the initial stage, and can reduce the output of the laser beam and the irradiation time. Further, since the sealing cap 70 and the protruding portion 163 are in line contact, the applied pressure can be reduced. Therefore, deformation of the liquid inlet member 160, the sealing cap 70, etc. can be reduced.

[Third embodiment]
A third embodiment will be described. The configuration of the battery 1 according to this embodiment is the same as that of the first embodiment. The differences between the first embodiment and this embodiment are the shape of the protrusions of the liquid inlet member and the shape of the sealing cap. That is, as for the cross-sectional shape of the projection part in this form, the tip shape is circular. The sealing cap has a groove at a position corresponding to the protrusion.

  FIG. 6 is a cross-sectional view of the vicinity of the liquid injection port 261 in the present embodiment before sealing. Also in this embodiment, the conditions of the laser beam irradiation diameter L and the protrusion width A are the same as in the first embodiment. However, the cross-sectional shape of the tip of the protrusion 263 in this embodiment is circular, and the sealing cap 270 has a groove at a position corresponding to the protrusion 263. The protrusion height B in this embodiment is from the base of the protrusion 263 to the lower surface of the sealing cap 270. Also in this embodiment, the inner width C, the outer width D, and the outer width E are preferably larger than the protrusion height B.

  Therefore, the groove portion of the sealing cap 270 is placed along the protruding portion 263 without strict alignment when the sealing cap 270 is placed on the liquid inlet member 260. As a result, the sealing cap 270 is positioned with respect to the protrusion 263. Therefore, in this embodiment, when the sealing cap 270 is placed on the liquid inlet member 260, the alignment can be facilitated.

[Fourth form]
A fourth embodiment will be described. The configuration of the battery 1 according to this embodiment is the same as that of the first embodiment. The difference between the first embodiment and this embodiment is a laser beam irradiation method. Therefore, the laser beam irradiation method of this embodiment will be described with reference to the configuration of FIG. The laser light irradiation method in this embodiment irradiates the projection 63 with the laser light divided into a plurality of times.

  Also in this embodiment, the conditions of the laser beam irradiation diameter L, the protrusion width A, the inner width C, the outer width D, and the outer width E are the same as in the first embodiment. In the laser beam irradiation method of this embodiment, the laser beam is continuously irradiated in a plurality of circles as shown by the irradiation unit I, starting from a predetermined position of the irradiation unit I shown in FIG. At this time, the irradiation head irradiates the irradiation part I a plurality of times with laser light at high speed. In other words, the laser beam is irradiated a plurality of times along the protrusion 63 at a high speed.

  Further, in the laser beam irradiation method of this embodiment, the laser beam is irradiated from the predetermined position of the irradiation unit I as a starting point and continuously irradiated in a plurality of circles as indicated by the irradiation unit I, and then the starting point is exceeded. Irradiate. That is, the irradiation part I has a wrap part having a predetermined length. That is, the laser beam is irradiated once more at the lap portion of the protrusion 63 than at the other portions.

  Here, the output and the irradiation time of the laser beam are set so that the sealing cap 70 sinks by the projection height B when the laser beam finishes irradiating the irradiation unit I with a plurality of rounds and the lapping unit. . That is, when the irradiation with the laser beam is completed, the sealing cap 70 and the bonding surface 62 come into contact with each other.

  By irradiating the laser beam in this way, the laser beam is irradiated in a plurality of times at the local portion of the protrusion 63. Therefore, the sinking amount of the sealing cap 70 every time the laser light is irradiated once is small. Therefore, the inclination when the sealing cap 70 sinks can be reduced, and defective bonding can be reduced.

  Further, although the configuration shown in FIG. 3 has been described in the description of this embodiment, the same effect can be obtained even when applied to the configuration shown in FIG. 5 or FIG.

[Fifth embodiment]
A fifth embodiment will be described. The configuration of the battery 1 according to this embodiment is the same as that of the first embodiment. The difference between the first embodiment and this embodiment is a laser beam irradiation method. Therefore, the laser beam irradiation method of this embodiment will be described with reference to the configuration of FIG. The laser light irradiation method in this embodiment irradiates the projection 63 with laser light simultaneously and uniformly.

  Also in this embodiment, the conditions of the inner width C, the outer width D, and the outer width E are the same as those in the first embodiment. However, the irradiation head which irradiates the laser beam of this embodiment is equipped with a lens capable of condensing the laser beam in the same shape as the irradiation unit I shown in FIG. And the irradiation method of the laser beam of this form irradiates the whole irradiation part I simultaneously and uniformly. That is, the laser light is simultaneously and uniformly applied to the protrusion 63. Therefore, the regulation of the irradiation diameter L of the laser beam described above with reference to FIG. 3 is the irradiation width L that is the beam width when the irradiated laser beam reaches the protrusion 63. Also in this embodiment, it is preferable that the protrusion width A is larger than the irradiation width L in the relationship between the protrusion width A and the irradiation width L.

  Here, in this embodiment, it is only necessary to irradiate the projecting portion 63 simultaneously and uniformly with laser light. For example, laser light focused on an area larger than the projecting portion 63 is used, and the protective member 90 is used as a mask. A role may be granted. In other words, in this case, the protective member 90 does not transmit the laser beam uniformly, but the laser beam is not transmitted to any part other than the irradiation part I so that the laser beam is not irradiated to the part other than the protrusion 63. Alternatively, a material may be used.

  As described above, in this embodiment, the laser beam is irradiated onto the protrusion 63 simultaneously and uniformly. Therefore, there is no wrap portion as described above in the first and fourth embodiments. This is because there is no starting point at which laser light irradiation starts. Further, when the local portions of the protrusions 63 are compared, the melting is simultaneous. Therefore, the sealing cap 70 can be submerged almost without being inclined, and defective bonding can be reduced.

  Further, although the configuration shown in FIG. 3 has been described in the description of this embodiment, the same effect can be obtained even when applied to the configuration shown in FIG. 5 or FIG.

  As described above in detail, the battery and the battery manufacturing method according to the present embodiment seal the liquid injection port by bonding the sealing cap to the liquid injection port member forming the liquid injection port. In this case, a target joining width can be stably obtained, and further, a battery and a battery manufacturing method that can be efficiently produced while reducing defects are provided.

  Note that this embodiment is merely an example, and does not limit the present invention. Accordingly, the present invention can naturally be improved and modified in various ways without departing from the gist thereof. For example, in the present embodiment, the projecting portion has been described as a continuous ring, but may be interrupted at a predetermined interval. At this time, the laser light irradiation method may be a method in which the laser light is irradiated at a predetermined interval in accordance with the shape of the protrusion.

  For example, in the present embodiment, the present invention is applied to a flat lithium ion secondary battery, but the present invention can also be applied to a cylindrical lithium ion secondary battery. For example, in the present embodiment, the present invention is applied to a lithium ion secondary battery, but the present invention can be similarly applied to a battery having an electrolytic solution.

DESCRIPTION OF SYMBOLS 1 ... Battery 40 ... Electrolytic solution 50 ... Battery case 60 ... Injection hole member 61 ... Injection hole 62 ... Joining surface 63 ... Projection part 70 ... Sealing cap 80 ... Joining part

Claims (6)

In a battery in which the injection port of a battery case containing a power generation element and an electrolyte is closed with a sealing member,
The liquid inlet member forming the liquid inlet is formed of a first type resin that absorbs laser light;
The sealing member is formed of a second type resin whose laser light absorption is lower than that of the first type resin;
The liquid injection port member and the sealing member have an annular joint at a contact portion surrounding the liquid injection port on the outer surface side, and the joint is closer to the sealing member than the liquid injection member. A battery characterized by large bite. In a method for manufacturing a battery by closing a liquid injection port of a battery case containing a power generation element and an electrolyte with a sealing member,
As the battery case, a portion of the liquid injection port is formed of a first type resin that absorbs laser light, and a bonding surface that surrounds the liquid injection port on the outer surface side is formed. A ring-shaped protrusion is formed around the liquid injection port,
After the liquid injection, the sealing member formed of the second type resin whose laser light absorption rate is lower than that of the first type resin is placed on the protrusion.
From above the sealing member, the projection member and its periphery are melted by passing through the sealing member and irradiating the projection portion with laser light, thereby bringing the sealing member into contact with the joint surface. A manufacturing method of a battery characterized by joining. In the manufacturing method of the battery according to claim 2,
The method of manufacturing a battery, wherein the protrusion has a shape that becomes narrower as the distance from the joint surface increases. In the manufacturing method of the battery of Claim 2 or Claim 3,
A battery in which a groove having a shape corresponding to the protrusion is formed at a position corresponding to the protrusion when mounted on the protrusion as the sealing member. Manufacturing method. In the manufacturing method of the battery in any one of Claim 2 to Claim 4,
When irradiating the projecting portion with laser light, the projecting portion is continuously irradiated in a ring shape,
Then, after returning to an irradiation start position, irradiation is further continued along the said projection part, The manufacturing method of the battery characterized by the above-mentioned. In the manufacturing method of the battery in any one of Claim 2 to Claim 4,
A method of manufacturing a battery, wherein when the projection is irradiated with laser light, the projection is irradiated simultaneously and uniformly.

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