JP5602050B2 - Joining method and battery - Google Patents

Description

  The present invention relates to a joining apparatus and a joining method for joining at places where it is difficult to install jigs, and a battery manufactured using them.

A conventional joining method will be described with reference to FIGS.
7A and 7B are diagrams showing the structure of the battery. FIG. 7A is a longitudinal sectional view, and FIG. 7B is a bottom view. FIG. 10 is a diagram for explaining a conventional joining method.

Conventionally, spot welding by a resistance welding machine has been widely used as a method of joining the cylindrical can 76 of the cylindrical lithium battery and the negative electrode 7 as shown in FIG.
The principle is that nickel or nickel-plated copper clad material is sandwiched by a long rod-shaped tungsten electrode at the bottom of the inner surface of a nickel-plated deep-drawn cylindrical iron can (hereinafter abbreviated as cylindrical can 76). The metal at the joint interface is melted and welded by heat generated by the contact resistance of the contact portion. However, since the contact portion is short-circuited with a large current, it is difficult to eliminate sputtering. For this reason, a thin film electrode having a laminated structure is bonded to the tungsten electrode. However, the positive electrode plate and the negative electrode plate may be internally short-circuited due to the mixture of spatters, and a rapid temperature increase may occur, making it difficult to ensure reliability. It was.

An effective method other than the above resistance welding for reducing spatter will be described with reference to FIG.
As shown in FIG. 10, this method is a method in which the metal pieces 91a and 93 are pressed by a cylindrical jig, the laser beam A is irradiated to melt the bonding interface, and the metal pieces 91a and 93 are joined. is there. However, with this method, bonding can be performed with a resin or a low-melting-point metal. However, when joining a metal such as nickel with a melting point exceeding 1000 ° C., it is difficult to exceed the melting point because much heat is taken away by the cylindrical jig. Therefore, it is not suitable for joining high melting point materials. Even if it can be joined, it is joined only at the center due to the temperature gradient, and since the joined area is small, the electrical resistance of the joint is high, and in EVs and HEVs that require a large current to flow, the heat generated by the original lithium battery is high. The capacity of density and large current could not be fully utilized. In addition, when spatter occurs, the space above the jig is vacant, so that the spatter jumps out and the quality is lowered.

  Furthermore, in the case of a cylindrical can lithium battery, since the laminated electrode is wound, only a hole with a diameter of about 3 mm is formed in the center of the cylindrical can, and it is physically difficult to install a holding jig in the first place ( For example, see Patent Document 1).

  Therefore, most of them are currently produced by resistance welding machines, but the welding rods of resistance welding machines need to be replaced frequently several times every day, and spattering cannot be eliminated. It was only possible to find a defect due to sputtering.

JP-A-4-220164

  In order to solve the above problems, the present invention suppresses the occurrence of spatter by an easy method and secures a bonding area even when welding a place where it is difficult to install a jig or the like. Objective.

In order to achieve the above object, a joining method according to the present invention includes a hollow tool including a laser beam waveguide, and a hollow annular nozzle provided at a tip of the hollow tool and having an inwardly tapered inner wall. A joining method for joining a joining target supported by a conductive support using a joining device comprising: a press-contacting step for pressing a tip of the annular nozzle against the joining target; and the support and the hollow tool. A step of assisting heating with heat generated by contact resistance by applying a voltage between the first electrode and the first laser beam having a first laser power from the annular nozzle through the hollow tool. A first irradiation step of heating the object, and a second laser beam having a power greater than the first power and a shorter wavelength than the first laser beam is irradiated from the annular nozzle onto the bonding target. Second and a irradiation step, a portion where the laser beam is irradiated directly with heat conduction type welding, the annular nozzle the laser beam is irradiated to the inner wall of the annular nozzle for bonding the bonding target by As a result of being heated, the portion where the annular nozzle to be joined is in contact by thermal diffusion joining.

  In addition, by the irradiation of the second laser light, the portion of the bonding target that is directly irradiated with the second laser light is liquefied at a temperature not lower than the melting point of the bonding target and not higher than the boiling point. It is preferable that the portion in contact with the nozzle is softened at a temperature equal to or lower than the melting point of the bonding target.

Moreover, it is preferable to flow an inert gas to the said joining object during the said irradiation process.
Moreover, it is preferable to heat the back surface of the surface where the said annular nozzle of the said joining object is press-contacted during the said irradiation process.

Furthermore, the battery of the present invention comprises a cylindrical can, a laminated electrode is built into the cylindrical can, a hollow portion formed by exposing the cylindrical can bottom into the cylindrical can, the cylindrical can bottom And an electrode joined by the joining method.

  As described above, even when a place where it is difficult to install a jig or the like is welded, the generation of spatter can be suppressed by an easy method and the bonding area can be secured.

  A hollow tool that becomes a laser beam waveguide is provided with an annular part with a diameter that decreases toward the tip. When welding a narrow and deep part, an annular nozzle is inserted into the welded part, and the welded part passes through the hollow tool from the annular nozzle. By irradiating the laser beam to the welded portion that is directly irradiated with the laser beam, the welded portion that is in contact with the annular nozzle is thermally diffusion bonded by heating the annular nozzle that is irradiated with the laser beam. By doing so, even when welding a place where it is difficult to install a jig or the like, it is possible to suppress the generation of spatter by an easy method and to secure a bonding area.

Sectional drawing explaining the process of the joining method of this invention The figure which shows the structural example of the hollow tool of this invention The figure which shows the structural example of the annular nozzle of this invention The figure explaining the joining method which controls the laser pulse of this invention Laser power transition diagram illustrating a bonding method for controlling laser pulses according to the present invention The figure which shows the structural example in the case of forming an unevenness | corrugation in the front-end | tip of the annular nozzle of this invention Diagram showing battery structure Schematic bottom view explaining the joint shape of the present invention Schematic bottom view showing a bonding shape example of the present invention The figure explaining the conventional joining method

  The present invention relates to a joining method and a joining apparatus for welding a bottom portion such as a recess having a narrow opening area and a deep depth as in the case of joining an electrode to the bottom portion of a cylindrical can battery. In such a place, since a holding jig or the like cannot be provided at the time of joining, a hollow tool provided with an optical fiber or the like serving as a laser optical waveguide for irradiating the joint with laser light, and a tip of the hollow tool It joins using the joining apparatus provided with the cyclic | annular nozzle which is provided and the area of a hollow part becomes narrow as it goes to a front-end | tip. Specifically, the hollow tool is inserted to the bottom of the recess so that the annular nozzle comes into contact with the joining portion, and the joining is performed by irradiating the joining portion with laser light through the hollow tool. By joining by such a method, the heat conduction type welding is performed at the place where the laser beam at the joint is directly irradiated. At the same time, the laser beam is irradiated onto the inner wall of the annular nozzle, whereby the annular nozzle is heated, and the joining portion in contact with the annular nozzle is subjected to thermal diffusion bonding by the pressure and heat of the annular nozzle. In this way, even when welding a place where it is difficult to install a jig or the like, it is possible to suppress the generation of spatter by an easy method by covering the joint portion with an annular nozzle, and the joint portion is thermally conductive welding. And the thermal diffusion bonding, the bonding area can be ensured.

First, the outline of the present invention will be described mainly using a cylindrical can battery as an example.
The basic principle of the present invention is that a slight space at the center of a laminated electrode that is vulnerable to heat is passed through like a catheter, and the tip of a nozzle is applied to a tail part at the bottom like a cylindrical can battery, via an optical fiber or the like. In this method, the generated laser beam is confined and the generation of spatter is completely confined by heat conduction welding or thermal diffusion bonding.

  In addition, when joining products that require a reduction in joint resistance, such as for electric vehicles (EV) and hybrid cars (HEV), after preheating by applying a low-intensity long pulse laser to the nozzle tip, Switch to pulse, heat diffusion bonding at the metal interface overlapped by the nozzle holder, and heat conduction type welding on the laser direct irradiation surface, high quality and stable bonding without generating spatter in the laminated electrode In addition to realizing the above, the performance of the battery itself can be improved so that the junction area can be increased and a large current required for the EV or HEV can flow.

  For example, in the joining method according to the present invention, an annular surface of a pointed nozzle is provided at the tip of a pressure member of a hollow tool that transmits laser light substantially in parallel, and the second member is a cylindrical can such as an iron can. The annular surface of the nozzle is brought into contact with the electrode plate, which is the first member placed in contact with the tail portion of the nozzle, and the first member is directly heated by the laser beam passing through the inside of the annular surface. Since the opening is small on the inside, the laser beam hits the annular surface, absorbs a part of the laser beam and generates heat to deform the electrode plate by heating and pressurizing by heat transfer. A certain electrode plate and the inner tail part of the cylindrical can which is the second member are joined. At the bonding interface opposite to the surface directly irradiated with laser light, heat conduction welding or heat diffusion bonding is performed by laser welding, and heat diffusion bonding is performed at the surrounding pressurizing portion, and the bonding mode and the bonding location are doubled. Therefore, compared to the keyhole type bonding, the bonding area can be increased, and the performance of EV and HEV batteries that require a large current can be greatly improved.

  Moreover, since laser irradiation is performed in a hollow tool that is a hollow pressure member, spatter and metal particles can be confined in the hollow pressure member, and these spatter and metal particles enter the surrounding laminated electrode. The risk of short-circuiting can be eliminated, and extremely safe and highly reliable bonding can be realized.

Note that the tip of the pressure member is preferable because the wear resistance and durability are improved by using hollow ceramics that generate heat by appropriately absorbing the laser.
As another joining method according to the present invention, the laser irradiation surface of the electrode as the first member and the laser beam partial absorption portion at the tip of the hollow tool are made low in luminance while the electrode is pressurized with the hollow tool. The contact surface between the electrode and the cylindrical can is heated by the first laser beam that is a long pulse to the temperature immediately before melting, and is switched to a high intensity and short pulse laser power of about 1 to 100 milliseconds. It is also possible to carry out heat conduction type laser welding by instantaneously exceeding the melting point. Further, at the bonding interface of the pressure annular surface at the tip of the hollow tool opposite to the electrode, thermal diffusion bonding can be performed by applying pressure even if the melting point is not reached.

In this way, since double electrode joining with a large area can be performed, a high-quality high-performance battery capable of flowing a large current can be provided for EV and HEV.
In addition, by providing multiple concave and convex portions such as chrysanthemum on the tip pressurizing part of the hollow tool, the electrodes joined by this joining method can realize strong joints against rotational moments, so that they are highly resistant to vibrations, etc. High battery can be provided.

  In addition, when an electrode is pressurized while flowing an antioxidant gas such as nitrogen or an inert gas such as argon into the hollow tool, these gases flow until just before being sealed by the pressurization. Since the oxygen content is extremely low, oxidation at the joint can be prevented. Therefore, in the electrode joining of nickel plated iron cylindrical cans, insufficiently oxidized iron is not on the surface, so that corrosion in the solution in the battery can be prevented and a highly reliable battery can be provided.

  Further, when laser light is guided by an optical fiber to the tapered portion in the hollow tool, a more robust joining device can be realized without being affected by the bending of the hollow tool. Here, an optical fiber and a hollow tool can be easily formed into a cylinder. However, the optical fiber can be made to collide with inert gas from the two target spaces on the laser irradiation surface by H-cutting etc. Since the inert gas purity is higher, it is possible to firmly build the nickel-covered state at the joint between the nickel electrode and the nickel-plated iron can, thus preventing corrosion of the solution in the battery. A battery with high reliability can be provided.

Moreover, when the surface opposite to the joint portion between the electrode and the cylindrical can tail is preheated or simultaneously heated, a high joint quality can be obtained in a shorter time.
In addition, when the back surface is assisted heated with a laser, the inert gas purity will be higher if the inert gas from the two target spaces collides with the irradiated surface. Can eliminate nickel plating damage and can provide a highly reliable battery resistant to external corrosion.

  Furthermore, by joining by the said joining method, the laminated electrode is incorporated in the cylindrical can which is a 2nd member, and the center axis | shaft of a cylindrical can is a space without a laminated electrode, and a laminated electrode A battery with double joint marks on the bottom of the cylindrical can and the cylindrical can can be formed, and since the joint area is larger than that of normal resistance welding, high quality can be used for EV and HEV. A high-performance battery can be provided.

Hereinafter, the joining method and battery of the present invention will be described in detail with reference to FIGS. 1 to 9 by taking as an example the case of welding an electrode to the bottom of a cylindrical can battery.
FIG. 1 is a cross-sectional view illustrating the steps of the joining method of the present invention, FIG. 2 is a diagram illustrating a configuration example of a hollow tool of the present invention, FIG. 3 is a diagram illustrating a configuration example of an annular nozzle of the present invention, and FIG. FIG. 5 is a laser power transition diagram for explaining a joining method for controlling a laser pulse according to the present invention, and FIG. 6 is for forming an unevenness at the tip of an annular nozzle according to the present invention. FIG. 8 is a schematic bottom view illustrating the joint shape of the present invention, and FIG. 9 is a schematic bottom view illustrating the joint shape example of the present invention.

First, the joining process of the present invention will be described in time series with reference to FIG. Here, a case where a rectangular wave that maintains the same luminance is used as the laser light will be described as an example.
In the following description, when welding the electrode 7 to the cylindrical can tail portion 6 which is the inner bottom surface of the cylindrical can battery, the hollow tool 2 is inserted through the gap between the stacked electrodes of the cylindrical can battery, and the annular nozzle 3 is connected to the cylindrical can. A method for joining the electrode 7 to the cylindrical can tail portion 6 by contacting the electrode 7 placed on the tail portion 6 and irradiating the electrode 7 with the laser beam 1 through the hollow tool 2 will be described as an example.

  As shown in FIG. 1A, the pointed annular nozzle 3 provided in the hollow tool 2 that transmits the laser light 1 in parallel is tapered so that the inner wall of the hollow portion is narrowed inward. The laser beam 4 is heated by a part of the laser beam 4 that is directly irradiated onto the annular nozzle 3. An electrode 7 is placed on the cylindrical can tail portion 6, and an inert gas 8 flowing inside the hollow tool 2 is blown onto the electrode surface 9 of the electrode 7. In addition, actual laser irradiation is performed after the hollow tool 2 contacts or pressurizes the electrode 7.

  Further, the cylindrical can tail portion 6 is supported by a support base 10 having low thermal conductivity, and the assist laser beam 13 is further irradiated to the surface 12 on the opposite side of the pressurizing portion to which the inert gas 8 is blown by counter blow, The cylindrical can tail portion 6 may be preheated or assisted heated. In the case of assist heating, since oxidation due to an inert gas can be suppressed, nickel plating damage on the back surface of the cylindrical can tail portion 6 can be eliminated, so that a highly reliable battery resistant to external corrosion can be provided.

FIG. 1B shows a state in which the annular nozzle 3 of the hollow tool 2 is in contact with the electrode 7, and the contact portion 5 is sealed with the electrode 7 surrounded by the annular nozzle 3, resulting in a high purity inert gas atmosphere. Become.
FIG. 1C shows a state in which the melted portion 14 is formed from the electrode 7 to the cylindrical can tail portion 6 by continuously irradiating the laser beam 1 in a pressurized state. At this time, since the annular nozzle 3 of the hollow tool 2 is heated by the laser beam 4 on the surface opposite to the annular surface 15 of the electrode 7 pressurized by the annular nozzle 3 at the tip of the hollow tool 2, The heat diffusion bonding part 16 is formed by bonding by heating.

  FIG. 1D shows a state where the laser irradiation is finished and the hollow tool 2 and the electrode 7 are separated from each other, and the cylindrical can tail portion 6 and the electrode 7 are formed by the melt-solidified portion 17 and the thermal diffusion bonding portion 16. It is joined. Note that deformation 19 such as a depression may be observed due to heating and pressurization of the hollow tool 2.

FIG. 2A is a cross-sectional view illustrating a form example of the hollow tool 2. In this embodiment, the waveguide of the hollow tool 2 is constituted by the optical fiber 21 and the laser beam is irradiated through the core 23. Inside the optical fiber 21, a hollow portion is provided in a part of the periphery of the core 23 so that the N ₂ gas 26 can pass therethrough. For example, the hollow portion is formed by H-cutting a part of the periphery of the optical fiber 21 facing each other with the core 23 therebetween so that the cut surfaces are parallel to each other. Then, has a hollow portion is H cut portion to the configuration N ₂ gas 26 is passed. Thus, even when the hollow tool 2 is formed using the optical fiber 21, it can be joined while supplying the N ₂ gas 26 and the like by forming the hollow portion.

FIG. 2B is a side view showing another embodiment of the hollow tool 2.
A nozzle 20 made of heat-resistant ceramics such as SiC having a high laser light absorption rate is bonded to the tip of the hollow tool 2 with a high-temperature adhesive 18, and a high-temperature heat-resistant optical fiber 21 is tapered inside the hollow tool 2. Up to 22 are inserted. Of the laser light emitted from the core 23 of the optical fiber 21, a direct heating beam 24 for directly heating the electrode 7 and a beam 25 for heating the inner wall of the cylinder of the nozzle 20 and indirectly heating the electrode 7 by heat transfer. The electrode 7 is heated.

  Further, as shown in FIG. 2B, as the nozzle 20, a conductive metal such as copper tungsten having high heat resistance and partially absorbing the laser beam to heat the electrode 7 to near the melting point and having conductivity at the same time. When used, when pressure is applied by the nozzle 20, heating assist may be performed by applying a voltage 27 between the conductive support base 10 such as copper and a hollow tool such as stainless steel or copper and by heat due to contact resistance.

  FIG. 3 is a side view of another embodiment of the present invention. A nozzle 31 made of a heat-resistant / laser light transmissive ceramic such as BN is attached to the tip of the hollow tool 2 as an annular nozzle, and the laser beam is focused on the nozzle 31. By providing the convex lens 30, the laser beam 32 emitted from the core portion 23 of the optical fiber 21 is converted into a condensed beam 33 to heat and melt the electrode 7 made of Ni, copper, aluminum or the like more efficiently.

  The laser light transmitting ceramic nozzle 31 partially absorbs the laser light 32 and is heated to a high temperature up to the vicinity of the melting point of the electrode 7. 6 can be heat diffusion bonded.

Next, an example of a bonding method will be described with reference to FIGS.
FIG. 4 shows a process in which bonding can be performed more effectively by controlling the waveform of the laser power P (W).
FIG. 4 shows a state in which the electrode 7 is pressurized by the nozzle 20, and FIG. 5 shows a time transition of the laser power of the laser light 1 irradiated through the nozzle 20.

  First, the laser irradiation surface 40 of the electrode 7 and the laser beam partial absorption unit 41 at the tip of the nozzle 20 are irradiated with a first laser beam 46 that is a long pulse with a low-intensity laser power P1 shown in FIG. The heating part 42 of the laser irradiation surface 40 of the electrode 7 and the heat transfer part 43 of the cylindrical can are preheated to a temperature just before melting over time t1. At this time, the pressurizing electrode portion 44 pressurized at the tip end of the nozzle 20 has the same time t1 to near the melting point by heat transfer from the laser beam partial absorption portion 41 at the tip of the nozzle heated by the laser beam 1. The temperature rises over time.

  Next, in the electrode 7, the electrode 7 and the cylindrical can tail are switched by switching to the second laser light 47 having a high-intensity laser power P 2 having a shorter wavelength than the first laser light 46 in a short time t 2 of about several milliseconds. The heating part 42 and the heat transfer part 43 on the contact surface with the part 6 are liquefied at a temperature exceeding the melting point of the forming material of the electrode 7 and not exceeding the boiling point, and the electrode 7 and the cylindrical can tail part 6 are of the heat conduction type. Laser welding is performed. At that time, the electrode 7 softens at a temperature equal to or lower than the melting point of the forming material of the electrode 7 at the bonding interface 45 on the opposite surface of the pressing electrode portion 44 that is pressed by the tip of the hollow tool. The cylindrical can tail portion 6 is heat diffusion bonded.

  In this way, by controlling the laser power of the laser beam 1 to be irradiated and preheating the bonding portion with the low-intensity laser beam 46 in advance, the actual bonding can be performed instantaneously with the high-intensity laser beam. In addition, since it is possible to perform double-area electrode joining of heat conduction type welding and thermal diffusion joining, it is possible to provide a high-quality high-performance battery capable of flowing a large current for EV and HEV.

Next, a configuration example of the tip of the annular nozzle will be described with reference to FIG.
FIG. 6 shows an example in which, in the joining method according to the first embodiment, the pressurizing portion is made uneven to realize strong joining against the rotational moment.

  FIG. 6A shows a side view and FIG. 6B shows a view from the bottom, and the tip pressurizing portion 60 of the hollow tool 2 is processed into a structure having a plurality of irregularities such as a chrysanthemum. That is, the structure which forms one or several unevenness | corrugations in the front-end | tip pressurization part 60 which contacts the electrode 7 of a cyclic | annular nozzle is illustrated.

  FIG. 6C is a top view of the electrode 7 joined by the tip pressurizing unit 60. The indented portion 61 is a bonded portion surface appearance formed by pressurizing with a convex portion formed in the tip pressurizing portion 60, and the bonding interface 63 is heat diffusion bonded. The flat portion 62 is a portion pressurized by the concave portion.

  It should be noted that the bonding interface 63 on the opposite side of the flat surface portion 62 of the tip pressurizing unit 60 is not necessarily heat diffusion bonded, but is bonded by welding and a double bonding principle, so that highly reliable bonding is achieved. Realized.

In addition, there may be a case where there is a gap between the flat portion 62 and the electrode 7 until the end of bonding. In this case, the metal vapor 64 generated from the melted portion 14 that is the laser irradiation surface of the electrode 7 diffuses by the free molecular motion of the metal vapor 64 in a closed space where there is no flow velocity. If the metal vapor 64 adheres to the nozzle tip 31 (see FIG. 3) having a ceramic lens function, the laser transmittance decreases, but this is effective in preventing the adhesion. That is, as shown in FIG. 2, when the nozzle tip 20 is completely pressed against the electrode 7 and completely closed, the atmosphere is N ₂ gas or argon gas atmosphere, but since the flow velocity is lost, the vaporized metal vapor 64 is free molecules. It may diffuse due to movement and adhere to the outlet 65 from the core 23 of the optical fiber 21, causing damage to the outlet 65.

  On the other hand, as described above, irregularities are formed in the tip pressurizing portion 60, and grooves are formed from the inner wall to the outer wall of the tip pressurizing portion 60, so that the convex and concave portions of the irregularities are brought into pressure contact with the electrode 7. Since the bottom of the recess that becomes the groove can be separated from the electrode 7, the inert gas 67 having a high pressure and a low flow rate is being joined from the slight gap 66 formed between the flat portion 62 and the electrode 7. The metal vapor 64 can be prevented from adhering to the outlet 65, damage can be prevented, and stable high-quality bonding can be maintained.

  In addition, the electrode 7 joined by this joining method can provide a highly reliable battery that is resistant to vibration and the like because the indentation portion 61 can provide an anchor effect at the joining location and can realize a strong joint against the rotating moment of the cylindrical can. can do.

  When the electrode 7 is pressurized while flowing the inert gas 8 into the hollow tool 2, the inert gas 8 flows, so that the sealed space becomes extremely low in oxygen content and prevents oxidation. it can. Therefore, in the electrode joining of the nickel-plated iron cylindrical can tail portion 6, iron that is not sufficiently oxidized is not on the surface, so that corrosion by the solution in the battery can be prevented and a highly reliable battery can be provided.

A structure of a battery formed by using the bonding method of the present invention will be described with reference to FIGS.
FIG. 7 shows the structure of a battery as one embodiment of a joined body joined by the joining method of the present invention.

  The battery of the present invention has a structure in which a laminated electrode 70 is built in a cylindrical can 76 and a space without the laminated electrode 70 is formed in the vicinity of the central axis 71 of the cylindrical can 76. FIG. 8 is a conceptual diagram in which the electrode 7 connected to the laminated electrode 70 is removed from the bottom 72 of the cylindrical can 76, and is a battery having double joint marks of a melting portion 75 and a donut-type heat diffusion joint portion 73. FIG. 9 shows another double joint mark. This is made by the shape of the nozzle tip formed with the unevenness shown in FIG. 6, and the melting portion 75 and the concave heat diffusion joining portion 74 are formed.

Since these joined bodies have a larger joining area than ordinary resistance welding, it is possible to provide a high-quality high-performance battery capable of flowing a large current for EVs and HEVs.
In the above description, the tail joint of the cylindrical can battery has been described in the embodiment in which a laser waveguide such as a catheter is inserted and pressed to join the battery, but a similar tail joint shape is not limited to the battery. It is obvious that non-metals can be pressure bonded or thermally bonded without selecting a material such as glass or resin.

For example, a reinforcing plate can be joined by entering a long pipe such as a nuclear reactor like a catheter and supplying laser energy with an optical fiber.
Moreover, not only a cylindrical can but an electrode and another component can also be joined to the inner surface tail part of a deep drawing case by pressurization and heating.

  It is also obvious that a brazing material can be applied to the electrodes and case and bonded by pressing and heating. For example, when joining a Ni lead to the bottom of an aluminum can of a lithium battery, an aluminum brazing material is applied in advance between the bottom of the aluminum can and the Ni lead, and the aluminum can bottom and the Ni are pressed and heated in that state. Leads can be joined.

It is also effective for other laminated foil electrodes such as copper foil.
Here, the embodiments illustrated above can also be used in combination with each other.

  Even when welding a place where it is difficult to install a jig or the like, the present invention can suppress the generation of spatter by an easy method and can secure a bonding area, which makes it difficult to install the jig. The present invention relates to a bonding apparatus and a bonding method for bonding at a location, a battery using the same, and the like.

DESCRIPTION OF SYMBOLS 1 ... Laser beam 2 ... Hollow tool 3 ... Ring nozzle 4 ... Part of laser beam 5 ... Contact part 6 ... Cylindrical can tail part 7 ... Electrode 8 ... Inert gas 9 ... electrode surface 10 ... support base 12 ... surface opposite to pressurizing part 13 ... assist laser beam 14 ... melting part 15 ... annular surface 16 ... heat Diffusion bonding part 17 ... Melt solidification part 18 ... High temperature adhesive 19 ... Depression deformation part 20 ... Nozzle 21 ... Optical fiber 22 ... Tapered part 23 ... Core 24 ... direct heating beam 25 ... indirect heating beam 26 ... _{N 2} gas 27 ... voltage 30 ... lens 31 ... nozzle 32 ... laser beam 33 ... focused beam 40 ... laser Irradiation surface 41 ... Laser light partial absorption part 42 ... Heating part 43 ... Heat transfer part DESCRIPTION OF SYMBOLS 4 ... Pressure electrode part 45 ... Bonding interface 46 ... 1st laser beam 47 ... 2nd laser beam 60 ... Tip pressurizing part 61 ... Recessed part 62 ... Flat part 63 ... Bonding interface 64 ... Metal vapor 65 ... Outlet 66 ... Gap 67 ... High pressure / low flow inert gas 70 ... Multilayer electrode 71 ... Central axis 72 ..Bottom of cylindrical can 73 ... Doughnut type heat diffusion bonding part 74 ... Concave heat diffusion bonding part 75 ... Melting part 76 ... Cylinder can 80 ... Laminated foil electrode 81 ... High current Power source 82... Partial melting portion 91 a. Metal piece 93.

Claims (5)

It is supported on a conductive support using a joining device comprising a hollow tool having a laser beam waveguide and a hollow annular nozzle provided at the tip of the hollow tool and having an inner wall with an inward taper shape. A joining method for joining objects to be joined,
A pressure-contacting step of pressing the tip of the annular nozzle against the object to be joined;
Applying a voltage between the support and the hollow tool to assist heating with heat due to contact resistance;
A first irradiation step of heating the joining object by irradiating the joining object with a first laser beam having a first laser power from the annular nozzle through the hollow tool;
A second irradiation step of bonding the bonding target by irradiating the bonding target from the annular nozzle with a second laser beam having a power larger than the first power and a wavelength shorter than that of the first laser beam; The portion to be directly irradiated with the laser beam is heat conduction welded, and the annular nozzle is heated by irradiating the inner wall of the annular nozzle with the laser beam, thereby the annular nozzle to be joined A bonding method characterized by heat diffusion bonding a portion that contacts.   Due to the irradiation of the second laser light, the portion to which the second laser light of the bonding target is directly irradiated is liquefied at a temperature not lower than the melting point of the bonding target and not higher than the boiling point, and the annular nozzle of the bonding target is The joining method according to claim 1, wherein the contacting portion is softened at a temperature equal to or lower than the melting point of the joining object.   The joining method according to claim 1, wherein an inert gas is allowed to flow through the joining target during the irradiation step.   The joining method according to any one of claims 1 to 3, wherein a back surface of a surface to which the annular nozzle to be joined is pressed is heated during the irradiation step. A cylindrical can,
A laminated electrode incorporated in the cylindrical can;
A hollow part formed by exposing the cylindrical can bottom in the cylindrical can;
It has an electrode joined by the joining method of any one of Claims 1-4 in the said cylindrical can bottom part, The battery characterized by the above-mentioned.

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