JP2009048963A - Battery and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a battery in which welding failure can be reduced when an electrolytic solution injecting port is sealed. <P>SOLUTION: This includes a process (a) of injecting electrolytic solution through a solution injecting port, a process (b) of arranging a sealing member 20 by positioning it at the solution injecting port, a process (c) of melting a laser welding part 26 of the sealing part 20 and a laser welding part 36 of a solution intake port formation part 33 by irradiating a laser beam 60, and a process (d) of cooling and solidifying the melted laser welding parts 26, 36 and joining the sealing member 20 and the solution injecting port forming part 33. Here, at least a part of non-laser welding part 28 of the sealing member 20 is arranged via a gap 25 between itself and the solution injecting port forming part 33 in the positioning process (b), and in the process (c), the laser welding part 26 is contacted with the solution injecting port forming part 33 when a prescribed amount of the laser welding part 26 is melted. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a battery and a manufacturing method thereof.

  In recent years, lithium-ion batteries, nickel-metal hydride batteries, and other secondary batteries have become increasingly important as power sources for vehicles or as power sources for personal computers and portable terminals. In particular, a lithium ion battery that is lightweight and obtains a high energy density is expected to be preferably used as a high-output power source mounted on a vehicle.

  By the way, in one typical configuration of this type of battery, a battery element obtained by winding (or laminating) a positive electrode and a negative electrode through a separator is housed in a metal can as an outer case, and then a lid body. Is attached to seal the meeting portion between the metal can and the lid. Subsequently, a predetermined amount of electrolyte solution is injected from the electrolyte solution injection port of the lid, and laser irradiation is performed with a metal sealing member fitted to the electrolyte solution injection port. The boundary with the liquid mouth is melted and integrated.

For example, in Patent Document 1, after injecting an electrolytic solution from a liquid inlet, the electrolytic solution and the oxide film attached around the liquid inlet are removed, and then a metal sealing member is inserted into the liquid inlet. A method of manufacturing a sealed battery welded by laser welding is disclosed.
JP 2000-21437 A

  However, in the above-described welding process by laser irradiation, it is important to control the laser welding amount to an appropriate amount. That is, if the amount of laser welding is too small, a gap is formed at the boundary between the sealing member and the liquid injection port, causing welding failure. If the amount of laser welding is too large, the electrolyte or residue attached to the laser irradiation part The support salt that is volatilized by heat and contained in the electrolyte easily causes blowholes, and the welding quality deteriorates.

  This invention is made | formed in view of this point, The main objective is to provide the manufacturing method of the battery which can reduce the welding defect at the time of sealing a liquid injection port.

  The battery manufacturing method provided by the present invention is a method for manufacturing a battery (typically a sealed battery) including an electrode body including a positive electrode and a negative electrode, and an outer case that houses the electrode body together with an electrolyte. It is.

  That is, in the battery manufacturing method of the present invention, the step (a) of injecting an electrolytic solution from a liquid injection port provided in an exterior case, the alignment with the liquid injection port, and the surroundings around the liquid injection port A step (b) of arranging a sealing member having a laser welded portion that is in contact with the outer case and laser welded to the outer case and a non-laser welded portion that is not laser welded to the outer case; A step (c) of melting the laser welded portion of the sealing member and the corresponding laser welded portion of the outer case, and cooling and solidifying (curing) the melted laser welded portion, And (d) sealing the liquid injection port by joining the outer case. Here, at least a part of the non-laser welded portion of the sealing member is disposed through the gap with the outer case at the time of alignment in the step (b), and the laser in the step (c). The welding portion is configured to contact the outer case when a predetermined amount is melted.

  According to the battery manufacturing method of the present invention, when the laser welded portion is melted by a predetermined amount, the non-laser welded portion of the sealing member comes into contact with the outer case. The amount (for example, the melting amount of the sealing member) can be controlled. That is, by irradiating the laser beam until the non-laser welded portion of the sealing member interferes with the outer case, the amount of melting of the laser welded portion can be managed quantitatively. Thereby, the laser melting portion can be melted by an appropriate amount (that is, an amount capable of reliably welding the sealing member and the outer case), so that it is possible to avoid the occurrence of poor welding due to insufficient laser welding amount.

  In a preferable aspect of the battery manufacturing method disclosed herein, the laser welding portion of the sealing member is made of a thermoplastic resin that transmits the laser light. The laser welding portion of the outer case is made of a thermoplastic resin that absorbs the laser light.

  According to this manufacturing method, the sealing member and the outer case can be joined by laser resin welding. In such laser resin welding, the laser output can be reduced as compared with laser metal welding, so that the amount of heat generated during welding can be suppressed. Therefore, for example, even when an electrolyte residue adheres to the laser weld, it is possible to avoid volatilization of the electrolyte. As a result, the occurrence of blow holes and the like can be avoided, and the welding quality can be improved.

  In a preferred aspect of the battery manufacturing method disclosed herein, in the step (c), the laser beam is irradiated while pressing the sealing member against the exterior case. According to this manufacturing method, the adhesion between the sealing member and the outer case can be increased, and welding defects can be further reduced.

  In a preferable aspect of the battery manufacturing method disclosed herein, the non-laser welded portion of the sealing member is formed with a protrusion at a portion surrounded by the laser welded portion of the sealing member. Then, the alignment in the step (b) is performed by inserting the protrusion into the liquid injection port. According to this manufacturing method, the alignment between the sealing member and the liquid injection port is facilitated, and the alignment accuracy between them is increased. As a result, poor welding due to poor alignment between the sealing member and the liquid inlet can be reduced.

  In a preferred aspect of the battery manufacturing method disclosed herein, the protrusion is a tapered protrusion whose diameter increases from the front end to the rear end (base end, that is, the base side). In the step (c), the taper-shaped protrusion is brought into contact with the exterior case in a state where the rear end thereof is hooked on the liquid inlet (that is, a state where the taper-shaped protrusion is hooked on the inlet of the liquid inlet). Features. According to this manufacturing method, the alignment protrusion can be used as a non-laser welded portion that comes into contact with the exterior case during laser irradiation, and the configuration of the sealing member can be simplified. In addition, preferably, by providing the taper-shaped protrusion almost at the center of the sealing member, the sealing member is injected in the step (c) even when the alignment between the sealing member and the liquid injection port is slightly shifted. The tapered protrusion can be used as a guide that leads to the center position of the mouth.

  In a preferable aspect of the battery manufacturing method disclosed herein, the non-laser welded portion of the sealing member has a concave shape with respect to the laser welded portion of the sealing member (that is, an exterior case rather than the laser welded portion). It is formed so as to have a shape recessed on the side away from the head. The outer case is formed with a convex portion corresponding to the concave shape of the non-laser welded portion. And the alignment of the said process (b) is performed by inserting the convex part of the said exterior case in the concave shape of the said non-laser welding part, It is characterized by the above-mentioned. According to this manufacturing method, the alignment between the sealing member and the liquid injection port is facilitated, and the alignment accuracy between them is increased. As a result, poor welding due to poor alignment between the sealing member and the liquid inlet can be reduced.

  In a preferred embodiment of the battery manufacturing method disclosed herein, the sealing member is formed such that the front and back sides thereof have the same shape (that is, the front and back side irregularities are the same shape, and therefore the front and back sides are the same. (Shape without difference). According to this configuration, when the sealing member is aligned with the liquid injection port in the step (b), the front / back determination of the sealing member becomes unnecessary. As a result, the manufacturing process can be simplified.

  In addition, the battery provided by the present invention includes an exterior case having a resin-made liquid inlet forming portion, a liquid inlet provided in the liquid inlet forming portion, and laser welding to the liquid inlet forming portion. And a resin-made sealing member that seals the liquid injection port. That is, the liquid injection port is sealed by the sealing member laser welded to the liquid injection port forming portion of the exterior case. The sealing member has a tapered protrusion whose diameter increases from the front end to the rear end. Here, the sealing member and the liquid injection port forming portion are laser welded in a state where the tapered protrusion is hooked on the liquid injection port.

  In the battery having such a configuration, by inserting the tapered protrusion into the liquid injection port at the battery manufacturing stage, the alignment between the sealing member and the liquid injection port is facilitated, and the alignment accuracy is increased. Therefore, poor welding due to poor alignment between the sealing member and the liquid inlet can be reduced, and a battery having high reliability can be provided.

  The battery provided by the present invention is laser-welded to the outer case provided with a resin-made liquid inlet forming portion, the liquid inlet provided in the liquid inlet forming portion, and the liquid inlet forming portion. And a resin sealing member that seals the liquid injection port. That is, the liquid injection port is sealed by the sealing member in which the sealing member is laser welded to the liquid injection port forming portion of the exterior case. The sealing member includes a laser welded portion that is laser welded to the liquid injection port forming portion, and a non-laser welded portion that is not laser welded to the liquid injection port forming portion. The non-laser welded portion is formed to be concave with respect to the laser welded portion. Further, the liquid injection port forming portion is formed with a convex portion corresponding to the concave shape of the non-laser welded portion. Here, the sealing member and the liquid injection port forming portion are joined in a state where the convex portion of the liquid injection port forming portion is fitted to the concave shape of the non-laser welded portion. .

  In the battery having such a configuration, in the battery manufacturing stage, by fitting the convex portion of the liquid injection port forming portion to the concave shape of the non-laser welded portion, the alignment between the sealing member and the liquid injection port becomes easy. The alignment accuracy is also increased. Therefore, poor welding due to poor alignment between the sealing member and the liquid inlet can be reduced, and a battery having high reliability can be provided.

  In addition, it is preferable that the said sealing member has the unevenness | corrugation of the same shape in the front and back before laser welding. Thereby, when aligning a sealing member with a liquid injection port, the front-and-back determination of a sealing member becomes unnecessary and a manufacturing process can be simplified. As a result, a battery having higher reliability can be provided.

  Embodiments according to the present invention will be described below with reference to the drawings. In the following drawings, members / parts having the same action are described with the same reference numerals. Hereinafter, the structure of the battery of the present invention will be described in detail by taking the prismatic lithium ion secondary battery 100 as an example, but the present invention is not intended to be limited to the one described in the embodiment. In addition, the dimensional relationships (length, width, thickness, etc.) in each drawing do not reflect actual dimensional relationships.

  The configuration of the lithium ion secondary battery 100 (hereinafter also referred to as “battery 100”) according to the first embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic top view of the battery 100 according to the first embodiment, and FIG. 2 is a schematic front view of the battery 100. However, for the convenience of illustration, a part of FIG. 2 (near a liquid injection port to be described later) shows a cross-section in which the outer case is cut away. The battery 100 disclosed herein includes an electrode body 70 including a positive electrode and a negative electrode, and an outer case 30 that houses the electrode body 70 and an electrolyte.

  The electrode body 70 of the first embodiment is made of a predetermined battery constituent material (active material for each of the positive and negative electrodes, current collector for each of the positive and negative electrodes, a separator, and the like) in the same manner as the unit cell included in a typical assembled battery. It is configured. In addition, here, a flat wound electrode body 70 described later is used as the electrode body 70.

  The exterior case 30 of the first embodiment includes an exterior case main body 32 and a lid 34. The exterior case main body 32 has a shape (here, a box shape) that can accommodate a flat wound electrode body 70 described later. The exterior case main body 32 has an open end at the top thereof, and can accommodate the electrode body 70 via the open end. The lid 34 is a plate-like member that closes the upper end opening of the exterior case main body 32, and has a substantially rectangular shape here. The material of the exterior case 30 (the exterior case main body 32 and the lid body 34) is preferably a lightweight metal material having good thermal conductivity. Examples of such a metal material include aluminum, stainless steel, and nickel-plated steel. Can be mentioned.

  A liquid inlet forming portion 33 is provided in the center of the lid 34 of the exterior case. The liquid injection port forming portion 33 is a part of the lid 34 and forms an outer edge portion that defines the liquid injection port 10. The liquid injection port 10 is a liquid injection port for injecting an electrolytic solution. That is, the electrolytic solution can be stored in the exterior case 30 through the liquid injection port 10. The liquid injection port 10 of this embodiment is a substantially circular through hole that penetrates the lid body 34.

  The liquid injection port 10 is sealed by the sealing member 20 after the electrolyte solution is injected. The sealing member 20 of this embodiment is placed on the liquid injection port forming portion 33 and closes (covers) the liquid injection port 10. By sealing the sealing member 20, it is possible to prevent the electrolyte from leaking outside the case and mixing of moisture and the like into the case. The shape of the sealing member 20 should just be a shape which can seal the liquid injection port 10, and is a substantially circular shape with a larger diameter than the liquid injection port 10 in this example. The sealing member 20 is placed on the liquid injection port forming portion 33 so as to close the liquid injection port 10, and the liquid injection port 10 is joined by joining the sealing member 20 and the liquid injection port forming portion 33. Can be sealed. The sealing member 20 and the injection hole forming portion 33 are joined by resin welding using a laser transmission welding method.

  Next, the laser welding procedure will be described with reference to FIGS. 3-6 is process sectional drawing which shows each process of laser welding.

First, as shown in FIG. 3, an electrolytic solution (not shown) is injected from the injection port 10 provided in the injection port forming part 33 of the lid 34. In this embodiment, a nonaqueous electrolytic solution in which an electrolyte is dissolved in a nonaqueous solvent is injected. As a non-aqueous solvent constituting this electrolytic solution, a mixed solvent of diethyl carbonate and ethylene carbonate (for example, a mass ratio of 1: 1) is used. In addition, as the electrolyte (supporting salt) constituting this electrolytic solution, one or more selected from various lithium salts (for example, lithium hexafluorophosphate (LiPF ₆ ), etc.) containing fluorine as a constituent element are used. Can do.

  The liquid injection port forming part 33 is made of a thermoplastic resin that has corrosion resistance to the electrolytic solution and exhibits a property of absorbing laser light. Such a thermoplastic resin can be easily produced by incorporating a laser absorber (for example, carbon black) into a thermoplastic resin such as polyphenylene sulfide (PPS).

  Next, as shown in FIG. 4, the sealing member 20 that seals the liquid injection port 10 is arranged in alignment with the liquid injection port 10. In the illustrated example, the sealing member 20 is placed on the liquid injection port forming portion 33 so as to block the upper part of the liquid injection port 10. The sealing member 20 is made of a thermoplastic resin that has corrosion resistance to the above-described electrolytic solution and transmits laser light (for example, has a laser transmittance of 30% or more at a thickness level of 1 mm). Examples of such a thermoplastic resin include polyphenylene sulfide (PPS) and polypropylene (PP). The liquid injection port forming portion 33 is formed integrally with the lid body 34 in advance by insert molding.

  Moreover, the sealing member 20 and the injection hole formation part 33 are arrange | positioned in the state which contacted the surfaces to weld. In this example, the laser welded portion 26 of the sealing member 20 and the laser welded portion 36 of the liquid injection port forming portion 33 are disposed in surface contact with each other. On the other hand, the surfaces that are not welded are arranged in a state of being separated from each other. That is, the non-laser welded portion 28 of the sealing member 20 and the non-laser welded portion 38 of the liquid injection port forming portion 33 are disposed with the gap 25 interposed therebetween.

  The dimensions of the liquid injection port 10 and the sealing member 20 are illustrated as follows. The liquid injection port 10 is a substantially circular through hole having a diameter of about 1.6 mm. On the other hand, the sealing member 20 has a larger diameter than the liquid injection port 10. Moreover, the thickness of the laser welding part 26 of the sealing member 20 should just be a thickness (for example, 2 mm or less) which can permeate | transmit the laser beam 60, and is about 1 mm in this example. Further, the thickness of the non-laser welded portion 28 of the sealing member 20 is smaller than the thickness of the laser welded portion 26 and is about 0.6 mm. Thereby, the gap 25 between the non-laser welded portion 28 of the sealing member 20 and the non-laser welded portion 38 of the liquid injection port forming portion 33 is set to be about 0.4 mm.

  Next, as shown in FIG. 5, the laser beam 60 is irradiated to melt the laser welded portion 26 of the sealing member 20 and the laser welded portion 36 of the liquid injection port forming portion 33. The laser beam 60 is a semiconductor laser, for example. In addition to the semiconductor laser, various lasers (for example, a gas laser) can be used. The laser beam 60 passes through the sealing member 20 and is absorbed by the laser welding portion 36 of the liquid inlet forming portion 33 as indicated by an arrow. The laser welding part 36 of the injection hole forming part 33 is first melted by the heat at the time of absorption, and then the laser welding part 26 of the sealing member 20 is melted. In this example, the laser output is about 20 W. The laser output can be adjusted as appropriate according to the battery configuration conditions (for example, resin material, sealing member thickness, etc.) and manufacturing conditions (laser oscillation source, etc.).

  The irradiation with the laser beam 60 is performed while pressing the sealing member 20 against the liquid injection port forming portion 33. In this example, a plate-like member 62 is arranged on the sealing member 20, and the sealing member 20 is pressurized toward the liquid injection port forming portion 33 with the plate-like member 62 (see arrow “64”). Laser light 60 is irradiated. The plate-like member 62 only needs to be a material that transmits the laser beam 60. For example, a glass plate-like member can be preferably used. By this pressurization, the adhesion between the sealing member 20 and the liquid injection port forming portion 33 can be increased, and poor welding can be reduced.

  If the laser beam 60 is continuously irradiated in the state shown in FIG. 5, the laser welding portion 26 of the sealing member 20 is melted, and the thickness thereof gradually decreases. Accordingly, the gap 25 between the non-laser welded portion 28 of the sealing member 20 and the non-laser welded portion 38 of the liquid injection port forming portion 33 is gradually narrowed.

  As shown in FIG. 6, when the non-laser welded portion 28 of the sealing member 20 and the non-laser welded portion 38 of the liquid injection port forming portion 33 come into contact with each other (that is, the gap 25 disappears), the laser beam 60 is irradiated. Is completed. That is, in this embodiment, when the laser welding part 26 of the sealing member 20 is melted by a predetermined amount, the non-laser welding part 28 of the sealing member 20 is configured to contact the liquid injection port forming part 33. . The amount of melting of the sealing member 20 is quantitatively managed by controlling the irradiation of the laser beam 60 based on the presence or absence of this contact.

  In addition, the presence or absence of contact of the sealing member 20 can be easily determined by sensing the pressure of the plate-like member 62 during pressurization. For example, a pressure sensor can be provided on the plate-like member 62, and the laser light irradiation can be completed based on information indicating an increase in pressure from the pressure sensor. Alternatively, the presence or absence of contact may be determined by sensing the height of the plate-like member 62 during pressurization. For example, it is possible to provide a position sensor on the plate-like member 62 and complete the irradiation of the laser light based on information indicating no height variation from the position sensor.

  As shown in FIG. 6, the melted laser welded portion 26 of the sealing member 20 and the laser welded portion 36 of the liquid injection port forming portion 33 are mixed to form an integrated laser welded portion 35. The integrated laser welding portion 35 is cooled (for example, left) and cured (solidified), whereby the sealing member 20 and the liquid injection port forming portion 33 are joined. Thus, the joining by the laser welding of the sealing member 20 and the injection hole formation part 33 is completed.

  According to the battery manufacturing method of the first embodiment, when a predetermined amount of the laser welded portion 26 of the sealing member 20 is melted, the non-laser welded portion 38 of the sealing member 20 contacts the liquid injection port forming portion 33. Since it contacts, the melting amount of a sealing member can be controlled based on the presence or absence of applicable contact. That is, the amount of melting of the sealing member 20 can be quantitatively managed by irradiating the laser beam 60 until the non-laser welded portion 28 of the sealing member 20 interferes with the liquid injection port forming portion 33. Accordingly, an appropriate amount (that is, an amount capable of reliably welding the sealing member and the exterior case) of the sealing member 20 can be melted, and welding defects due to laser welding can be reduced.

  Moreover, in this embodiment, the sealing member 20 and the injection hole formation part 33 can be joined by resin welding (welding) with a laser. In laser resin welding, laser output can be reduced compared to laser metal welding (for example, laser output requires several hundred W for metal welding, but may be less than 100 W for resin welding). The amount of heat generated at the time can be suppressed. Therefore, for example, even when an electrolyte residue adheres to the laser welds 26 and 36, the evaporation of the electrolyte residue can be avoided. As a result, the occurrence of blow holes and the like can be avoided, and the welding quality can be improved.

  Next, the configuration of the lithium ion secondary battery 200 according to the second embodiment of the present invention will be described with reference to FIGS. 7 and 8. The second embodiment is different from the battery 100 described above in that the sealing member 220 is provided with a tapered protrusion 240. Therefore, the same components as those of the battery 100 are denoted by the same reference numerals, and redundant description thereof is omitted.

  As shown in FIG. 7, the non-laser welded portion 228 surrounded by the laser welded portion 226 of the sealing member 220 is formed with a protrusion 240 that protrudes higher than the laser welded portion 226. The protrusion 240 is a taper-shaped (substantially truncated cone-shaped) protrusion 240 whose diameter increases from the front end to the rear end. In the illustrated example, the tapered protrusion 240 is provided at the center of the lower surface of the sealing member 220 and is inclined so that the tip thereof is smaller than the opening diameter of the liquid injection port 10 and the rear end thereof is larger than the opening diameter. It is configured with. The tapered protrusion 240 can be used when the sealing member 220 and the liquid injection port 10 are aligned. That is, as shown in FIG. 7, the alignment between the sealing member 220 and the liquid injection port 10 can be easily performed by inserting the tapered protrusion 240 into the liquid injection port 10.

  Further, the tapered protrusion 240 can also serve as the non-laser welded part 228 that comes into contact with the liquid injection port forming part 233 during laser irradiation. That is, if the laser beam 60 is continuously irradiated in the state shown in FIG. 7, the laser welded portion 226 of the sealing member 220 is melted, and the tapered protrusion 240 and the non-laser welded portion 238 of the liquid injection port forming portion 33 The gap 225 is gradually narrowed. Then, as shown in FIG. 8, the taper-shaped protrusion 240 abuts on the liquid injection port forming portion 233, and the laser beam 60 is irradiated until the rear end of the protrusion 240 is hooked on the liquid injection port 10. The melting amount of the member 220 can be controlled to an appropriate amount.

  Thus, in 2nd Embodiment, by providing the protrusion 240 in the sealing member 220, alignment with the sealing member 220 and the liquid injection port 10 becomes easy, and both alignment accuracy also becomes high. . As a result, poor welding due to poor alignment between the sealing member 220 and the liquid injection port 10 can be reduced. Further, by forming the protrusion 240 in a tapered shape, it can be used as a non-laser welded portion that comes into contact with the liquid injection port forming portion 233 during laser irradiation, and the configuration of the sealing member 220 can be simplified. Further, by providing the tapered protrusion 240 at the center of the sealing member 220, the sealing member 220 is positioned at the center of the liquid injection port 10 even when the alignment between the sealing member 220 and the liquid injection port 10 is slightly shifted. A tapered protrusion 240 can be used as a guide for guiding to the surface.

  Further, the configuration of the lithium ion secondary battery 300 according to the third embodiment of the present invention will be described with reference to FIGS. 9 and 10. The third embodiment is different from the above-described batteries 100 and 200 in that a projection for positioning the sealing member is formed in the liquid injection port forming portion. Therefore, the same components as those of the batteries 100 and 200 are denoted by the same reference numerals, and redundant description thereof is omitted.

  As shown in FIG. 9, the non-laser welded portion 328 of the sealing member 320 is formed to have a concave shape with respect to the laser welded portion 326. In this example, the non-laser welded portion 328 is provided inside the laser welded portion 326. The liquid injection port forming portion 333 is formed with a convex portion 340 corresponding to the concave shape of the non-laser welded portion 328. Then, the alignment between the sealing member 320 and the liquid injection port 10 is performed by fitting the convex portion 340 of the liquid injection port forming portion 333 into the concave shape of the non-laser welded portion 328. Even if it is this structure, position alignment with a sealing member and a liquid injection port becomes easy, and the welding defect by position alignment defect can be reduced.

  The height of the convex portion 340 of the liquid injection port forming portion 333 is configured to be smaller than the concave height of the non-laser welded portion 328. Then, as shown in FIG. 10, by irradiating the laser beam 60 until the non-laser welded portion 328 of the sealing member 320 contacts the convex portion 340 of the liquid injection port forming portion 333, the melting amount of the sealing member 320 Can be controlled to an appropriate amount.

  In this way, when the non-laser welded portion 328 and the laser welded portion 326 of the sealing member 320 are formed to be uneven rather than substantially on the same surface, the same shape is formed on the front and back of the sealing member. And it is preferable to form the unevenness | corrugation of the same dimension. For example, FIG. 11 and FIG. 12 show an example of the sealing member 420 (battery 400 according to the fourth embodiment) in which concavities and convexities having the same shape and the same size are formed on the front and back sides. As shown in FIG. 11, unevenness (laser welded portion 426 and non-laser welded portion 428) similar to the sealing member 320 shown in FIG. 9 is formed on the lower surface of the sealing member 420. In addition, on the top surface of the sealing member 420, unevennesses 427 and 429 having the same shape corresponding to the unevenness (the laser welded portion 426 and the non-laser welded portion 428) are formed.

  In this configuration, the front / back determination of the sealing member 420 is not required when the sealing member 420 and the liquid injection port 10 are aligned. Therefore, the battery manufacturing process can be simplified. Even in the sealing member 420 having such a configuration, the laser beam is used until the non-laser welded portion 428 of the sealing member 420 contacts the convex portion 440 of the liquid injection port forming portion 433 as shown in FIG. By irradiating 60, the melting amount of the sealing member 420 can be controlled to an appropriate amount.

  Next, returning to FIG. 1 and FIG. 2, another manufacturing method of the battery 100 will be described with reference to each constituent material constituting the battery 100 of the first embodiment.

  First, the outer case 30 (the outer case main body 32 and the lid body 34) is prepared. The material of the exterior case 30 is not particularly limited as long as it is the same as that used in the conventional unit cell, but a relatively light material can be used. For example, a metal case having an insulating resin coating on the surface, a polyolefin resin such as polypropylene, and other synthetic resin cases are suitable. The lid 34 prepared here is integrally formed with the above-described resin injection hole forming portion 33 in advance by insert molding.

  Next, the electrode body 70 including the positive electrode 72 a and the negative electrode 72 b is accommodated in the exterior case main body 32. The electrode body 70 according to the present embodiment has a total of two sheet-like positive electrodes (hereinafter referred to as “positive electrode sheets”) and sheet-like negative electrodes (hereinafter referred to as “negative electrode sheets”), similarly to the electrode bodies of ordinary lithium ion batteries. The wound electrode body 70 is laminated and wound together with a sheet-like separator (hereinafter referred to as “separator sheet”).

  In the production of the wound electrode body 70, first, the positive electrode sheet and the negative electrode sheet are superposed together with a total of two separator sheets, the positive electrode sheet and the negative electrode sheet are further wound, and the obtained wound body is then side-faced. Created by crushing from the direction and kidnapping. Prior to winding, the active material layers of the positive electrode sheet and the negative electrode sheet are removed to expose the current collector, and the positive electrode lead terminal 74a and the negative electrode lead terminal are respectively exposed to the current collector exposed portions (positive electrode 72a and negative electrode 72b). 74b is attached. The positive electrode lead terminal 74a and the negative electrode lead terminal 74b are electrically connected to the positive electrode terminal 76a and the negative electrode terminal 76b provided on the lid 34, respectively.

The material and member itself constituting the wound electrode body 70 may be the same as the electrode body of a conventional lithium ion battery, and are not particularly limited. For example, the positive electrode sheet can be formed by applying a positive electrode active material layer for a lithium ion battery on a long positive electrode current collector. For the positive electrode current collector, an aluminum foil (this embodiment) or other metal foil suitable for the positive electrode is preferably used. As the positive electrode active material, one or more of materials conventionally used in lithium ion batteries can be used without any particular limitation. Preferable examples include LiMn ₂ O ₄ , LiCoO ₂ , LiNiO _{2 and the} like. For example, an aluminum foil having a length of 2 to 4 m (for example, 2.7 m), a width of 8 to 12 cm (for example, 10 cm), and a thickness of about 5 to 20 μm (for example, 15 μm) is used as a current collector. A positive electrode active material layer for lithium ion batteries mainly composed of lithium nickelate is formed by a conventional method (for example, lithium nickelate 88% by mass, acetylene black 10% by mass, polytetrafluoroethylene 1% by mass, carboxymethylcellulose 1% by mass). Thus, a suitable positive electrode sheet can be obtained.

  On the other hand, the negative electrode sheet can be formed by applying a negative electrode active material layer for a lithium ion battery on a long negative electrode current collector. For the negative electrode current collector, a copper foil (this embodiment) or other metal foil suitable for the negative electrode is preferably used. As the negative electrode active material, one or more of materials conventionally used in lithium ion batteries can be used without any particular limitation. Preferable examples include carbon-based materials such as graphite carbon and amorphous carbon, lithium transition metal oxides, and lithium transition metal nitrides. For example, a copper foil having a length of 2 to 4 m (for example, 2.9 m), a width of 8 to 12 cm (for example, 10 cm), and a thickness of about 5 to 20 μm (for example, 10 μm) is used. A suitable negative electrode sheet is obtained by forming a negative electrode active material layer for lithium ion batteries (for example, 98% by mass of graphite, 1% by mass of styrene butadiene rubber, 1% by mass of carboxymethyl cellulose).

  Moreover, what was comprised with porous polyolefin resin as a suitable separator sheet used between positive and negative electrode sheets is mentioned. For example, a porous separator sheet made of synthetic resin (for example, made of polyolefin such as polyethylene) having a length of 2 to 4 m (for example, 3.1 m), a width of 8 to 12 cm (for example, 11 cm), and a thickness of about 5 to 30 μm (for example, 25 μm). It can be preferably used. When a solid electrolyte or a gel electrolyte is used as the electrolyte, there may be a case where a separator is unnecessary (that is, in this case, the electrolyte itself can function as a separator).

  In addition, the electrode body accommodated in an exterior case is not limited to the said winding type. For example, it may be a laminated type electrode body in which a positive electrode sheet and a negative electrode sheet are alternately laminated together with a separator (or a solid or gel electrolyte that can also function as a separator).

  After the wound electrode body 70 is accommodated in the outer case main body 32, the lid body 34 is attached to seal the meeting portion between the outer case main body 32 and the lid body 34. Thereafter, an electrolytic solution is injected from the liquid injection port 10 formed in the lid 34, and the liquid injection port 10 is sealed with the sealing member 20. The electrolyte injection process and the sealing process are as described with reference to FIGS. In this way, the battery 100 according to the present embodiment is constructed.

  As mentioned above, although this invention was demonstrated by suitable embodiment, such description is not a limitation matter and of course various modifications are possible. For example, the type of battery is not limited to the above-described lithium ion battery, but batteries having various contents with different electrode body constituent materials and electrolytes, for example, lithium secondary batteries having a negative electrode made of lithium metal or lithium alloy, nickel hydrogen batteries, nickel cadmium It may be a battery or an electric double layer capacitor.

  The battery 100 according to the present embodiment can be suitably used as a power source for a motor (electric motor) mounted on a vehicle such as an automobile as shown in FIG. That is, the sealed battery 100 according to the present embodiment is arranged as a single battery in a predetermined direction, and the assembled battery 92 is constructed by restraining the single battery in the arrangement direction, and the vehicle including the assembled battery 92 as a power source. 90 (typically automobiles, in particular automobiles with electric motors such as hybrid cars, electric cars, fuel cell cars) can be provided.

The upper surface schematic diagram of the battery which concerns on 1st Embodiment. The front schematic diagram of the battery which concerns on 1st Embodiment. Process sectional drawing which shows each process of laser welding. Process sectional drawing which shows each process of laser welding. Process sectional drawing which shows each process of laser welding. Process sectional drawing which shows each process of laser welding. Process sectional drawing of the battery which concerns on 2nd Embodiment. Process sectional drawing of the battery which concerns on 2nd Embodiment. Process sectional drawing of the battery which concerns on 3rd Embodiment. Process sectional drawing of the battery which concerns on 3rd Embodiment. Process sectional drawing of the battery which concerns on 4th Embodiment. Process sectional drawing of the battery which concerns on 4th Embodiment. The side surface schematic diagram of the motor vehicle provided with the battery (assembled battery) which concerns on this embodiment.

Explanation of symbols

10 Injection port 20, 220, 320, 420 Sealing member 25, 225, 325, 425 Clearance 26, 226, 326, 426 Laser welded portion (sealing member)
28, 228, 328, 428 Non-laser welded part (sealing member)
30 exterior case 32 exterior case main body 33, 233, 333, 433 liquid inlet forming part 34 lid 35 laser welded part 36, 236, 336, 436 laser welded part (liquid inlet forming part)
38, 238, 338, 438 Non-laser welded part (injection port forming part)
60 Laser light 62 Plate member 70 Electrode 72a Positive electrode 72b Negative electrode 74a Positive electrode lead terminal 74b Negative electrode lead terminal 76a Positive electrode terminal 76b Negative electrode terminal 90 Vehicle 92 Battery pack 100, 200, 300, 400 Battery 240 Tapered protrusion 340 Convex part 440 Convex part Part

Claims (10)

A method for producing a battery comprising an electrode body comprising a positive electrode and a negative electrode, and an outer case containing the electrode body together with an electrolyte solution,
A step (a) of injecting the electrolytic solution from a liquid injection port provided in the outer case;
Aligned with the liquid inlet, and has a laser welded portion that is in contact with the outer case around the liquid inlet and is laser welded to the outer case, and a non-laser welded portion that is not laser welded to the outer case. A step (b) of disposing a sealing member;
A step (c) of irradiating a laser beam to melt a laser welded portion of the sealing member and a laser welded portion of the exterior case corresponding thereto; and
And (d) sealing the liquid injection port by bonding the sealing member and the exterior case by cooling and solidifying the melted laser weld portion,
Here, at least a part of the non-laser welded portion of the sealing member is disposed through a gap with the outer case at the time of the alignment in the step (b), and the laser in the step (c). A method for manufacturing a battery, wherein the welding portion is configured to abut against the outer case when a predetermined amount is melted. The sealing member is made of a thermoplastic resin that transmits the laser light,
The battery manufacturing method according to claim 1, wherein the laser welding portion of the exterior case is made of a thermoplastic resin that absorbs the laser light.   3. The battery manufacturing method according to claim 2, wherein in the step (c), the laser light is irradiated while pressing the sealing member against the exterior case. 4. In the non-laser welded portion of the sealing member, a protrusion is formed in a portion surrounded by the laser welded portion of the sealing member,
The battery manufacturing method according to claim 1, wherein the alignment in the step (b) is performed by inserting the protrusion into the liquid injection port. The protrusion is a tapered protrusion whose diameter increases from the front end to the rear end,
5. The method of manufacturing a battery according to claim 4, wherein, in the step (c), the tapered protrusion abuts the exterior case in a state where a rear end thereof is hooked on the liquid injection port. The non-laser welded portion of the sealing member is formed to be concave with respect to the laser welded portion of the sealing member,
The outer case has a convex portion corresponding to the concave shape of the non-laser welded portion,
The alignment in the step (b) is performed by inserting a convex portion of the outer case into a concave shape of the non-laser welded portion. Battery manufacturing method.   The method of manufacturing a battery according to claim 6, wherein the sealing member is formed so that the front and back thereof have the same shape. An exterior case having a resin injection hole forming portion;
A liquid inlet provided in the liquid inlet forming section;
A resin sealing member that is laser welded to the liquid inlet forming portion and seals the liquid inlet;
The sealing member has a tapered protrusion whose diameter increases from the front end to the rear end,
Here, the battery is characterized in that the sealing member and the liquid injection port forming portion are laser-welded in a state where the tapered protrusion is hooked on the liquid injection port. An exterior case having a resin injection hole forming portion;
A liquid inlet provided in the liquid inlet forming section;
A resin sealing member that is laser welded to the liquid injection port forming portion and seals the liquid injection port;
The sealing member has a laser welded portion laser welded to the liquid injection port forming portion, and a non-laser welded portion not laser welded to the liquid injection port forming portion,
The non-laser welded portion is formed to be concave with respect to the laser welded portion,
The liquid injection port forming portion is formed with a convex portion corresponding to the concave shape of the non-laser welded portion,
Here, the sealing member and the liquid injection port forming portion are laser welded in a state in which the convex portion of the liquid injection port forming portion is fitted in the concave shape of the non-laser welded portion. Do the battery.   A vehicle provided with the battery manufactured by the method as described in any one of Claims 1-7, or the battery as described in any one of Claims 8-9.

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