JP6098240B2 - Storage element manufacturing method and storage element - Google Patents

Description

  The present invention relates to a method for manufacturing a power storage element that manufactures a power storage element by welding a liquid injection stopper to a container in which a liquid injection port for injecting an electrolytic solution is formed, and a power storage element manufactured by the manufacturing method About.

  The shift from gasoline cars to electric cars has become important as a global environmental problem. For this reason, use of electrical storage elements such as nonaqueous electrolyte secondary batteries as a power source for electric vehicles has been studied.

  Such an electricity storage device includes a container in which an injection port for injecting an electrolytic solution is formed. And at the time of manufacture of the electrical storage element, an electrolyte solution is injected from the liquid injection port, and the liquid injection port is sealed by welding a liquid injection stopper to the container. However, if the electrolytic solution adheres around the liquid injection port, poor welding occurs when the liquid injection stopper is welded to the container.

  For this reason, conventionally, there has been proposed a method for manufacturing an electric storage element that can reduce the welding failure when removing the electrolytic solution around the liquid injection port and welding the liquid injection stopper to the container (for example, patents). Reference 1). In this method of manufacturing an electric storage element, a laser beam is irradiated around the liquid injection port without a liquid injection stopper being disposed on the container, and the periphery of the liquid injection port is melted by the laser beam to form a groove. By doing so, the electrolyte solution around the injection port is removed, and poor welding when the injection plug is welded to the container is reduced.

JP 2012-169254 A

  However, the conventional method for manufacturing a power storage element has a problem that the welding operation may not be performed smoothly when the liquid filling tap is welded to the container.

  That is, in the method for manufacturing an electricity storage element disclosed in Patent Document 1, the laser beam is irradiated around the liquid injection port in a state where the liquid injection stopper is not arranged in the container. For this reason, there is a possibility that a laser beam enters the container from the liquid injection port, and when the laser beam enters the container, problems such as melting of the separator in the container occur. In particular, in Patent Document 1 described above, since a laser beam that is strong enough to melt the periphery of the liquid injection port is irradiated, if the laser beam enters inside the container, it may cause a big problem. .

  Moreover, in the manufacturing method of the electrical storage element disclosed by the said patent document 1, the circumference | surroundings of the injection hole are melted with a laser beam, and the groove | channel is formed. For this reason, since it is necessary to place a liquid stopper on the container in which the groove is formed and to perform welding, the adhesion between the container and the liquid stopper is deteriorated, which affects the welding of the liquid stopper to the container. There is a fear.

  As described above, in the conventional method for manufacturing a power storage device, when welding a liquid stopper to the container, a laser beam enters the container or the adhesion between the container and the liquid stopper becomes poor. In some cases, the welding of the liquid injection stopper to the container cannot be performed smoothly.

  The present invention has been made in order to solve the above-described problem, and has been manufactured by a method for manufacturing an electric storage element capable of smoothly performing a welding operation when welding a liquid injection stopper to a container, and the manufacturing method. An object is to provide a power storage element.

  In order to achieve the above object, a method for manufacturing an energy storage device according to one embodiment of the present invention includes welding a liquid injection stopper to a container surface of a container in which a liquid injection port for injecting an electrolytic solution is formed. A method for manufacturing a power storage element for manufacturing a power storage element, the first irradiation step of irradiating a first laser beam to a first region including a region where the liquid injection stopper on the surface of the container is welded; By irradiating a second laser beam, which is stronger than the first laser beam, on a second region including a region on the liquid stopper with the liquid stopper being disposed, the liquid stopper is applied to the surface of the container. In the first irradiation step, the first laser beam having a strength that makes the surface of the container smooth is irradiated in the first irradiation step.

  According to this, in the method of manufacturing the electric storage element, first, the first region is irradiated with the first laser beam having such a strength that the surface of the container is smooth, and then the second laser beam stronger than the first laser beam is applied. The liquid injection stopper is laser welded to the container surface by irradiating the second region. In other words, by irradiating the first laser beam to the first region and smoothing the region where the liquid stopper on the surface of the container is welded, welding of the liquid stopper to the surface of the container can be performed in a stable state. it can. In addition, since the electrolyte remaining on the surface of the container can be dried by the heat generated when the first laser beam is applied to the first region, the injection stopper is welded to the container surface by the second laser beam. Can be performed in a stable state. Further, due to the residual heat when the first laser beam is applied to the first region, the injection stopper can be welded to the container surface with a weaker laser beam than before. As mentioned above, according to the manufacturing method of the said electrical storage element, when welding a liquid injection stopper to a container, a welding operation can be performed smoothly.

  Furthermore, the liquid injection stopper arrangement step of arranging the liquid injection stopper on the surface of the container so as to close the liquid injection port is included, and the liquid injection stopper is arranged on the surface of the container in the first irradiation step. In the state, the first laser beam may be applied to the first region.

  According to this, in the method for manufacturing the electric storage element, after the liquid injection stopper is disposed on the surface of the container so as to close the liquid injection port, the first laser beam is emitted in a state where the liquid injection stopper is disposed on the surface of the container. Irradiate. In this way, by irradiating the laser beam with the liquid injection stopper disposed on the surface of the container, it is possible to prevent the laser light from entering the container from the liquid injection port. Thereby, according to the manufacturing method of the said electrical storage element, when welding a liquid injection stopper to a container, a welding operation can be performed smoothly.

  In the first irradiation step, the first laser beam is positioned in the first region such that the center of the first laser beam is located in a region outside the region where the liquid injection stopper is disposed on the surface of the container. In the second irradiation step, the second region may be irradiated with the second laser beam so that the center of the second laser beam is positioned on the liquid stopper. .

  According to this, in the manufacturing method of the electric storage element, the container surface is strong so that the center of the first laser beam is located in a region outside the region where the liquid injection stopper is disposed on the container surface. The first laser beam is irradiated. That is, the first laser beam is irradiated to a region where the liquid injection stopper on the outer surface of the container is welded than the region where the liquid injection stopper is disposed. Thereby, according to the manufacturing method of the said electrical storage element, the area | region where the liquid injection stopper in the container surface is welded can be modified | reformed reliably, and the said area | region can be made smooth.

  Further, in the first irradiation step, the first laser beam may be irradiated to the first region so that at least a part of an outer edge of the first laser beam is located on the liquid injection stopper. .

  According to this, in the method for manufacturing the electricity storage device, the first laser beam having such a strength that the surface of the container is smooth is irradiated so that at least a part of the outer edge of the first laser beam is located on the liquid injection stopper. . That is, the surface is modified so that the outermost peripheral portion is smoothed by irradiating the punched portion of the outermost peripheral portion of the liquid injection stopper with the first laser beam. Thereby, according to the manufacturing method of the electric storage element, it is possible to reduce the burrs and the like of the punched portion at the outermost peripheral portion of the liquid injection stopper, and also to improve the surface of the upper end portion of the liquid injection stopper that is a welded portion. be able to.

  Further, in the first irradiation step, the first laser beam may be irradiated to the first region so that the center of the first laser beam moves around the outer periphery of the injection stopper. Good.

  According to this, in the method for manufacturing the electric storage element, the first laser beam is irradiated so that the surface of the container is smooth so that the center of the first laser beam moves all around the outside of the liquid stopper. To do. Thereby, according to the manufacturing method of the said electrical storage element, the whole area | region where a liquid stopper is welded can be improved uniformly, and the said area | region can be made smooth.

  Further, in the second irradiation step, the second laser beam is irradiated to the second region so that the center of the second laser beam moves around the outer peripheral portion of the liquid injection stopper. Good.

  According to this, in the manufacturing method of the said electrical storage element, a 2nd laser beam is irradiated so that the center of a 2nd laser beam may move the outer peripheral part of an injection stopper over the perimeter. Thereby, according to the manufacturing method of the said electrical storage element, laser welding can be carried out over the outer periphery whole periphery of the liquid injection stopper to the container surface smoothened by surface modification.

  In order to achieve the above object, a power storage device according to one embodiment of the present invention is disposed so as to close a container in which a liquid injection port for injecting an electrolytic solution is formed and the liquid injection port. An electric storage element comprising a liquid injection stopper, wherein a weld formed by laser welding the liquid injection stopper on the container surface of the container, and formed adjacent to the weld on the container surface, And a laser irradiation mark modified so that the surface of the container becomes smooth by being irradiated with a laser beam weaker than a laser beam irradiated by laser welding.

  According to this, in the electric storage element, the container surface is modified to be smooth by being irradiated with a laser beam weaker than the laser beam irradiated by laser welding adjacent to the welded portion on the container surface. Laser irradiation traces are formed. As described above, since the region where the liquid injection stopper on the surface of the container is welded is modified so as to be smooth and laser-welded, the storage element in which the injection of the liquid injection stopper to the container is performed in a stable state Has been realized. Thereby, according to the said electrical storage element, when welding an injection stopper to a container, the welding operation can be performed smoothly.

  Moreover, the said weld part may be formed in the outer peripheral part of the said liquid injection stopper over the perimeter, and the said laser irradiation trace may be formed over the perimeter so that the said weld part may be enclosed.

  According to this, in the electric storage element, the laser irradiation trace is formed over the entire circumference so as to surround the welded portion formed over the entire circumference of the outer peripheral portion of the liquid filling tap. As described above, since the entire region to which the liquid stopper is welded is uniformly smoothed and laser welded, a storage element in which the welding of the liquid stopper to the container is performed stably can be realized. .

  According to the method for manufacturing a power storage element of the present invention, welding work can be smoothly performed when the liquid filling tap is welded to the container.

It is a perspective view which shows typically the external appearance of the electrical storage element which concerns on embodiment of this invention. It is a perspective view which shows each component with which the electrical storage element which concerns on embodiment of this invention is provided. It is a figure which shows the structure of the injection stopper which concerns on embodiment of this invention. It is a figure which shows a structure when the liquid injection stopper which concerns on embodiment of this invention is welded to the cover body. It is a flowchart which shows the manufacturing method of the electrical storage element which concerns on embodiment of this invention. It is a figure for demonstrating the injection stopper arrangement | positioning process in the manufacturing method of the electrical storage element which concerns on embodiment of this invention. It is a figure for demonstrating the 1st irradiation process in the manufacturing method of the electrical storage element which concerns on embodiment of this invention. It is a figure for demonstrating the 1st irradiation process in the manufacturing method of the electrical storage element which concerns on embodiment of this invention. It is a figure for demonstrating the 2nd irradiation process in the manufacturing method of the electrical storage element which concerns on embodiment of this invention. It is a figure for demonstrating the 2nd irradiation process in the manufacturing method of the electrical storage element which concerns on embodiment of this invention. It is a figure which shows the structure of the electrical storage element which concerns on the modification of embodiment of this invention.

  Hereinafter, a power storage device and a method for manufacturing the same according to an embodiment of the present invention will be described with reference to the drawings. Each of the embodiments described below shows a preferred specific example of the present invention. The numerical values, shapes, materials, constituent elements, arrangement positions and connecting forms of the constituent elements, steps, order of steps, and the like shown in the following embodiments are merely examples, and are not intended to limit the present invention. In addition, among the constituent elements in the following embodiments, constituent elements that are not described in the independent claims indicating the highest concept are described as optional constituent elements.

(Embodiment)
First, the configuration of the power storage element 10 will be described.

  FIG. 1 is a perspective view schematically showing an external appearance of a power storage device 10 according to an embodiment of the present invention. FIG. 2 is a perspective view showing each component included in power storage device 10 according to the embodiment of the present invention.

  The power storage element 10 is a secondary battery that can charge electricity and discharge electricity, and more specifically, is a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery. In addition, the electrical storage element 10 is not limited to a nonaqueous electrolyte secondary battery, A secondary battery other than a nonaqueous electrolyte secondary battery may be sufficient, and a capacitor may be sufficient as it.

  As shown in FIG. 1, the electricity storage device 10 includes a container 100, a positive electrode terminal 200, a negative electrode terminal 300, and a liquid injection plug 400. As shown in FIG. 2, a positive electrode current collector 120, a negative electrode current collector 130, and an electrode body 140 are accommodated inside the container 100. Note that a liquid such as an electrolytic solution is sealed inside the container 100 of the power storage element 10, but the liquid is not shown.

  The container 100 includes a main body 111 having a rectangular cylindrical shape and a bottom, and a lid 110 that is a plate-like member that closes an opening of the main body 111. The container 100 can seal the inside by welding the lid body 110 and the main body 111 after accommodating the electrode body 140 and the like therein. In addition, although the material of the cover body 110 and the main body 111 is not specifically limited, For example, it is preferable that they are weldable metals, such as stainless steel and aluminum.

  Further, as shown in FIG. 2, a liquid injection port 110 a is formed in the lid 110 of the container 100. Here, the liquid injection port 110 a is a cylindrical through-hole for injecting an electrolytic solution when the electricity storage device 10 is manufactured. The liquid injection port 110a is not limited to a cylindrical shape, and may be a prismatic shape or the like.

  Moreover, as shown in FIG. 1, the liquid injection stopper 400 is arrange | positioned at the cover body 110 of the container 100 so that the liquid injection port 110a may be plugged up. That is, at the time of manufacturing the electricity storage device 10, the electrolytic solution is injected into the container 100 from the liquid injection port 110a, and the liquid injection stopper 400 is welded to the lid 110 to close the liquid injection port 110a. Housed inside. The detailed description of the liquid injection stopper 400 will be described later.

  In addition, as the electrolytic solution (nonaqueous electrolytic solution) sealed in the container 100, there is no particular limitation on the type thereof as long as the performance of the power storage element 10 is not impaired, and various types can be selected.

  The electrode body 140 includes a positive electrode, a negative electrode, and a separator, and is a member that can store electricity. The positive electrode is obtained by forming a positive electrode active material layer on a long belt-like positive electrode base foil made of aluminum or an aluminum alloy. The negative electrode is obtained by forming a negative electrode active material layer on a long strip-shaped negative electrode base foil made of copper, a copper alloy, or the like. The separator is a microporous sheet made of resin.

  Here, the positive electrode active material used for the positive electrode active material layer or the negative electrode active material used for the negative electrode active material layer may be a known material as long as it is a positive electrode active material or a negative electrode active material capable of occluding and releasing lithium ions. Can be used.

  And the electrode body 140 is formed by winding what is arranged in layers so that the separator is sandwiched between the negative electrode and the positive electrode. In addition, in the same figure, although the ellipse shape was shown as a shape of the electrode body 140, circular shape or elliptical shape may be sufficient. The shape of the electrode body 140 is not limited to a wound type, and may be a shape in which flat plate plates are laminated.

  The positive electrode terminal 200 is an electrode terminal electrically connected to the positive electrode of the electrode body 140, and the negative electrode terminal 300 is an electrode terminal electrically connected to the negative electrode of the electrode body 140. In other words, the positive electrode terminal 200 and the negative electrode terminal 300 lead the electricity stored in the electrode body 140 to the external space of the power storage element 10, and in order to store the electricity in the electrode body 140, It is an electrode terminal made of metal for introducing. The positive electrode terminal 200 and the negative electrode terminal 300 are attached to the lid body 110 disposed above the electrode body 140.

  The positive electrode current collector 120 is disposed between the positive electrode of the electrode body 140 and the side wall of the main body 111 of the container 100, and has electrical conductivity and rigidity that are electrically connected to the positive electrode terminal 200 and the positive electrode of the electrode body 140. It is a member provided. The positive electrode current collector 120 is made of aluminum or an aluminum alloy, like the positive electrode base material foil of the electrode body 140.

  The negative electrode current collector 130 is disposed between the negative electrode of the electrode body 140 and the side wall of the main body 111 of the container 100, and has electrical conductivity and rigidity electrically connected to the negative electrode terminal 300 and the negative electrode of the electrode body 140. It is a member provided. The negative electrode current collector 130 is formed of copper or a copper alloy, like the negative electrode base foil of the electrode body 140.

  Next, the structure of the liquid injection stopper 400 and the structure when the liquid injection stopper 400 is welded to the lid 110 will be described. First, the configuration of the liquid filling tap 400 will be described in detail.

  FIG. 3 is a diagram showing a configuration of the liquid filling tap 400 according to the embodiment of the present invention. Specifically, (a) of the figure is a plan view when the liquid injection stopper 400 before being welded to the lid 110 is viewed from above, and (b) of the figure is the lid 110. It is sectional drawing which shows the cross section of the liquid injection stopper 400 before welding.

  As shown in the figure, the liquid injection stopper 400 includes a fixing portion 410 that is fixed to the lid 110 by welding, and a protruding portion 420 that protrudes from the fixing portion 410.

  The fixing unit 410 is a disk-shaped member that is fixed on the lid 110 so as to close the liquid injection port 110a. The fixing portion 410 is formed of a metal that can be welded to the lid 110, such as stainless steel or aluminum. Note that the shape of the fixing portion 410 may be any shape such as a rectangular flat plate shape as long as it can close the liquid injection port 110a.

  The protruding portion 420 is a protruding portion that is inserted into the liquid injection port 110a. Specifically, the protruding portion 420 is a cylindrical portion protruding from the central portion of the fixed portion 410. Here, although the protrusion part 420 is integrally formed with the fixing | fixed part 410, you may be comprised separately. The shape of the protrusion 420 is not limited to a cylindrical shape, but is preferably a shape corresponding to the shape of the liquid injection port 110a.

  Next, a configuration when the liquid filling tap 400 is welded to the lid 110 will be described in detail.

  FIG. 4 is a diagram showing a configuration when the liquid filling tap 400 according to the embodiment of the present invention is welded to the lid 110. Specifically, (a) in the figure is a plan view when the state in which the liquid injection stopper 400 is welded to the lid 110 is viewed from above, and (b) in the figure shows the liquid injection stopper 400. FIG. 3 is a cross-sectional view showing a cross section of the liquid filling tap 400 and the lid body 110 in a state where is welded to the lid body 110.

  As shown in the figure, the protruding portion 420 of the liquid injection plug 400 is inserted into the liquid injection port 110 a of the lid 110, and the fixing portion 410 of the liquid injection plug 400 is disposed on the container surface 110 b which is the surface of the lid 110. In this state, the injection stopper 400 is welded to the container surface 110b to form a welded portion 631.

  That is, the welded portion 631 is a welded portion formed by welding the liquid injection stopper 400 to the container surface 110b of the container 100. Specifically, the liquid injection stopper 400 is laser-welded to the container surface 110b. It is the weld part formed by this.

  Moreover, in this Embodiment, the welding part 631 is formed in the outer peripheral part of the fixing | fixed part 410 of the liquid injection stopper 400 over the perimeter. That is, the weld part 631 is a donut-shaped part formed by melting the outer peripheral part of the fixed part 410 and the container surface 110b by laser welding.

  Note that the welded portion 631 may be formed only once around the outer peripheral portion of the fixed portion 410, or may be formed more than once. Further, the welded portion 631 may be formed not on the entire circumference of the outer peripheral portion of the fixed portion 410 but on a part thereof. A detailed description of the formation of the weld 631 will be described later.

  Further, a laser irradiation mark 511 is formed adjacent to the welded portion 631 on the container surface 110b. The laser irradiation mark 511 is irradiated with a laser beam that is weaker than the laser beam irradiated by laser welding to form the welded portion 631, so that the container surface 110b is modified to be smooth. It is a scar.

  In the present embodiment, the laser irradiation mark 511 is formed over the entire circumference so as to surround the welded portion 631. That is, the laser irradiation mark 511 is a donut-shaped portion formed on the outer surface of the welded portion 631 adjacent to the welded portion 631 on the container surface 110b.

  Note that the laser irradiation mark 511 may be formed only once around the welded portion 631 or may be formed two or more times. Further, the laser irradiation mark 511 may be formed not on the entire circumference outside the welded portion 631 but on a part outside the welded portion 631. A detailed description of the formation of the laser irradiation mark 511 will be described later.

  Next, the manufacturing method of the electrical storage element 10 is demonstrated.

  FIG. 5 is a flowchart showing a method for manufacturing power storage element 10 according to the embodiment of the present invention. Specifically, this figure is a flowchart for explaining a process of welding the liquid injection stopper 400 to the container surface 110b of the container 100 in which the liquid injection port 110a is formed in order to manufacture the electricity storage device 10.

  As shown in the figure, first, as the liquid injection stopper arranging step, the liquid injection stopper 400 is arranged on the container surface 110b so as to close the liquid injection opening 110a (S102). This injection stopper arrangement step will be described in detail below.

  FIG. 6 is a view for explaining a liquid injection stopper arranging step in the method for manufacturing power storage element 10 according to the embodiment of the present invention. Specifically, (a) in the figure is a plan view when the state in which the liquid injection stopper 400 is arranged on the container surface 110b is viewed from above, and (b) in the figure is an injection on the container surface 110b. FIG. 6 is a cross-sectional view showing a cross section of the liquid injection stopper 400 and the lid 110 in a state where the liquid stopper 400 is arranged.

  As shown in the figure, the protrusion 420 of the liquid injection stopper 400 is inserted into the liquid injection port 110a of the lid 110, and the fixing part 410 of the liquid injection stopper 400 is disposed on the container surface 110b of the lid 110. . Thereby, the injection stopper 400 is arrange | positioned at the container surface 110b so that the injection hole 110a may be plugged up.

  Returning to FIG. 5, next, as a first irradiation step, the first laser beam is irradiated to the first region including the region where the liquid injection stopper 400 of the container surface 110b is welded (S104). This first irradiation step will be described in detail below.

  7 and 8 are diagrams for describing the first irradiation step in the method for manufacturing power storage device 10 according to the embodiment of the present invention.

  Here, FIG. 7 is a diagram showing a state in which irradiation with the first laser beam 500 is started. Specifically, FIG. 7A shows a state in which irradiation with the first laser beam 500 is started. FIG. 5B is a cross-sectional view showing a cross section of the liquid filling tap 400 and the lid 110 in a state where irradiation with the first laser beam 500 is started.

  FIG. 8 is a diagram showing a state in which the irradiation of the first laser beam 500 is finished. Specifically, FIG. 8A shows a state in which the irradiation of the first laser beam 500 is finished from above. FIG. 2B is a cross-sectional view showing a cross section of the liquid filling tap 400 and the lid 110 in a state where the irradiation with the first laser beam 500 is finished.

  First, as shown in FIG. 7, irradiation of the first laser beam 500 is started on the first region 530a. That is, in the first irradiation step, the first laser beam 500 is irradiated to the first region 530a in a state where the liquid injection stopper 400 is disposed on the container surface 110b.

  Here, the first region 530a is a region including a region (a welding region 610a described later) to which the liquid injection stopper 400 of the container surface 110b is welded. That is, irradiation of the first laser beam 500 is started on the first region 530a including the region on the container surface 110b and the region on the fixing portion 410. Thus, in the first irradiation step, the first laser beam 500 is irradiated to the first region 530 a so that at least a part of the outer edge of the first laser beam 500 is located on the liquid injection plug 400.

  The first laser beam 500 is a laser beam having a strength that smoothens the surface of the irradiated region. Specifically, the first laser beam 500 is a laser beam having a strength that modifies the surface so that the surface of the irradiated region becomes smooth. That is, in the first irradiation step, the first laser beam 500 having an intensity that makes the container surface 110b smooth is irradiated.

  Thereby, a laser irradiation mark 510a is formed in a region in the first region 530a on the container surface 110b, and a laser irradiation mark 520a is formed in a region in the first region 530a on the fixing portion 410. The laser irradiation mark 510 a is a laser irradiation mark modified so that the container surface 110 b becomes smooth by being irradiated with the first laser beam 500, and the laser irradiation mark 520 a is the first laser beam 500. Is a mark of laser irradiation modified so that the surface of the fixing portion 410 becomes smooth by being irradiated.

  Further, the first laser beam 500 is irradiated so that the center P is located in a region on the container surface 110b outside the fixing portion 410 of the liquid injection stopper 400. That is, in the first irradiation step, the first laser beam is placed in the first region 530a so that the center P of the first laser beam 500 is located in a region outside the region where the liquid injection stopper 400 is disposed on the container surface 110b. Irradiate light beam 500.

  Further, in the first irradiation step, the first laser beam 500 is irradiated to the first region so that the center P of the first laser beam 500 moves around the outer periphery of the liquid filling tap 400. That is, the first laser beam 500 is irradiated over the entire circumference of the fixed portion 410 while moving so that the center P draws the movement locus 501 in FIG.

  As a result, as shown in FIG. 8, the first laser beam 500 is applied to the first region 530 over the entire circumference of the fixed portion 410. The first region 530 is a movement locus drawn by the first region 530a shown in FIG. 7 as the first laser beam 500 moves over the entire circumference of the fixed portion 410.

  Then, a laser irradiation mark 510 is formed in a region in the first region 530 on the container surface 110b, and a laser irradiation mark 520 is formed in a region in the first region 530 on the fixing portion 410.

  Here, the laser irradiation mark 510 is formed by the movement locus of the laser irradiation mark 510a shown in FIG. 7 as the first laser beam 500 moves over the entire circumference of the fixed portion 410, and the container surface 110b is smooth. It is a mark of laser irradiation modified so as to be. Further, the laser irradiation mark 520 is formed by the movement locus of the laser irradiation mark 520a shown in FIG. 7 when the first laser beam 500 moves over the entire circumference of the fixing portion 410, and the surface of the fixing portion 410 is smooth. This is a mark of laser irradiation modified so as to become.

  The smooth surface means that the surface is modified to improve the smoothness of the surface, that is, the unevenness formed on the surface and the non-smooth parts such as burrs during processing become smooth. Say that.

  As described above, the laser irradiation mark 520 is formed in a circular shape over the entire circumference of the outer peripheral portion of the fixed portion 410, and the laser irradiation mark 510 is formed in a circular shape over the entire periphery outside the laser irradiation mark 520.

  The shape of the laser irradiation marks 520 and 510 is not limited to a circular shape. For example, if the fixing portion 410 is rectangular, the laser irradiation marks 520 and 510 are also formed in a rectangular shape. Further, the laser irradiation mark 520 may be formed only once around the outer peripheral portion of the fixed portion 410, or may be formed two or more times. Similarly, the laser irradiation mark 510 is formed outside the laser irradiation mark 520. May be formed only once or two or more times. Further, the laser irradiation marks 520 and 510 may not be formed over the entire circumference, and may be formed in a part of the entire circumference.

  Returning to FIG. 5, next, as a second irradiation step, the second laser beam stronger than the first laser beam 500 is irradiated to the second region including the region on the liquid injection stopper 400, thereby pouring the container surface 110b. The liquid stopper 400 is laser welded (S106). This second irradiation step will be described in detail below.

  9 and 10 are diagrams for describing the second irradiation step in the method for manufacturing power storage device 10 according to the embodiment of the present invention.

  Here, FIG. 9 is a diagram showing a state in which the irradiation of the second laser beam 600 is started. Specifically, FIG. 9A shows a state in which the irradiation of the second laser beam 600 is started. FIG. 5B is a cross-sectional view showing a cross section of the liquid filling tap 400 and the lid 110 in a state where irradiation with the second laser beam 600 is started.

  FIG. 10 is a diagram showing a state in which the irradiation of the second laser beam 600 is finished. Specifically, FIG. 10A shows a state in which the irradiation of the second laser beam 600 is finished from above. FIG. 5B is a cross-sectional view showing a cross section of the liquid filling tap 400 and the lid 110 in a state where the irradiation with the second laser beam 600 is finished.

  First, as shown in FIG. 9, irradiation of the second laser beam 600 is started on the second region 630a. That is, in the second irradiation step, the second laser beam 600 is irradiated to the second region 630a in a state where the liquid injection stopper 400 is disposed on the container surface 110b following the first irradiation step.

  Here, the second region 630 a is a region including a region on the liquid filling tap 400. That is, irradiation of the second laser beam 600 is started on the second region 630a including the welded region 610a on the container surface 110b and the welded region 620a on the fixing portion 410. Thus, in the second irradiation step, the second laser beam 600 is irradiated to the second region 630a so that the second laser beam 600 straddles the container surface 110b and the fixing portion 410.

  The second laser beam 600 is a laser beam having a greater intensity than the first laser beam 500. Specifically, the second laser beam 600 is a laser beam having a strength that melts the surface of the irradiated region. In other words, in the second irradiation step, the second region 630a is irradiated with the second laser beam 600 having a strength for melting the container surface 110b and the fixing portion 410, so that the liquid injection stopper 400 is laser welded to the container surface 110b. .

  Further, the second laser beam 600 is irradiated so that the center Q is located in a region on the fixing portion 410 of the liquid filling tap 400. In other words, in the second irradiation step, the second laser beam 600 is irradiated to the second region 630 a so that the center Q of the second laser beam 600 is positioned on the liquid injection plug 400.

  Further, in the second irradiation step, the second region is irradiated with the second laser beam 600 such that the center Q of the second laser beam 600 moves around the outer periphery of the liquid injection plug 400 over the entire circumference. That is, the second laser beam 600 is irradiated over the entire circumference of the fixed portion 410 while moving so that the center Q draws the movement locus 601 in FIG.

  As a result, as shown in FIG. 10, the second laser beam 600 is irradiated to the second region 630 over the entire circumference of the fixed portion 410 to form a welded portion 631. That is, the welded portion 631 is a welded portion formed by laser welding the liquid injection stopper 400 to the container surface 110b in the region within the second region 630. The second region 630 is a movement locus drawn by the second region 630a shown in FIG. 9 as the second laser beam 600 moves over the entire circumference of the fixed portion 410.

  Further, in the laser irradiation trace 510 that is not included in the second region 630, the second laser beam 600 is not irradiated and the welded portion 631 is not formed, so that the laser irradiation trace 511 remains formed. become.

  As described above, the welded portion 631 is formed in a circular shape over the entire outer periphery of the fixed portion 410 of the liquid injection stopper 400, and laser irradiation is performed over the entire periphery so as to surround the welded portion 631 adjacent to the welded portion 631. The mark 511 is formed in a circular shape.

  In addition, the shape of the welding part 631 is not limited to a circular shape, For example, if the fixing | fixed part 410 is rectangular shape, the welding part 631 will also be formed in a rectangular shape. Further, the welded portion 631 may be formed only once around the outer peripheral portion of the fixed portion 410, or may be formed more than once. Moreover, the welding part 631 does not need to be formed over the said perimeter, and may be formed in a part of the said perimeter. Further, the laser irradiation trace 511 may be formed in a rectangular shape, two or more rounds, or formed in a part of the entire circumference, depending on the shape of the laser irradiation trace 510. You may decide.

  As described above, according to the method for manufacturing power storage element 10 according to the embodiment of the present invention, first region 530 is first irradiated with first laser beam 500 having a strength that makes container surface 110b smooth. Then, the second laser beam 600 stronger than the first laser beam 500 is irradiated to the second region 630, so that the liquid injection stopper 400 is laser welded to the container surface 110b. That is, by irradiating the first laser beam 500 to the first region 530 and smoothing the region where the liquid stopper 400 of the container surface 110b is welded, the welding of the liquid stopper 400 to the container surface 110b is stabilized. Can be done in the state. In addition, since the electrolyte remaining on the container surface 110b can be dried by the heat generated when the first laser beam 500 is applied to the first region 530, the second laser beam 600 is applied to the container surface 110b. The injection stopper 400 can be welded in a stable state. Further, due to the residual heat when the first laser beam 500 is applied to the first region 530, the liquid injection stopper 400 can be welded to the container surface 110b with a weaker laser beam than in the past. As mentioned above, according to the manufacturing method of the electrical storage element 10, when welding the liquid injection stopper 400 to the container 100, a welding operation can be performed smoothly.

  Further, in the method for manufacturing the electricity storage device 10, the first laser beam is placed in a state where the injection stopper 400 is arranged on the container surface 110 b after the injection stopper 400 is arranged on the container surface 110 b so as to block the injection hole 110 a. Irradiate 500. In this way, by irradiating the first laser beam 500 with the injection plug 400 placed on the container surface 110b, the first laser beam 500 is prevented from entering the container 100 from the injection port 110a. be able to. Thereby, according to the manufacturing method of the electrical storage element 10, when welding the liquid injection stopper 400 to the container 100, a welding operation can be performed smoothly.

  Further, in the method for manufacturing the electricity storage device 10, the container surface 110b is smooth so that the center of the first laser beam 500 is located in a region outside the region where the injection stopper 400 is disposed on the container surface 110b. An intense first laser beam 500 is irradiated. That is, the first laser beam 500 is irradiated to a region on the container surface 110b where the liquid injection stopper 400 outside the region where the liquid injection stopper 400 is disposed is welded. Thereby, according to the manufacturing method of the electrical storage element 10, the area | region where the liquid injection stopper 400 in the container surface 110b is welded can be modified | reformed reliably, and the said area | region can be made smooth.

  Further, in the method for manufacturing the electricity storage device 10, the first laser beam 500 having a strength that makes the container surface 110 b smooth is irradiated so that at least a part of the outer edge of the first laser beam 500 is positioned on the liquid injection stopper 400. To do. In other words, the first laser beam 500 is irradiated on the punched portion of the outermost peripheral portion of the liquid filling plug 400 to modify the surface so that the outermost peripheral portion becomes smooth. Thereby, according to the manufacturing method of the electrical storage element 10, the burr | flash etc. of the punching part of the outermost periphery part of the liquid injection stopper 400 can be reduced, and the upper surface edge part of the liquid injection stopper 400 which is a welding location is surface-modified. Can be quality.

  Moreover, in the manufacturing method of the electrical storage element 10, the 1st laser beam 500 of the intensity | strength that the container surface 110b becomes smooth so that the center P of the 1st laser beam 500 may move the outer periphery of the injection stopper 400 over a perimeter. Irradiate. Thereby, according to the manufacturing method of the electrical storage element 10, the whole area | region where the liquid injection stopper 400 is welded can be uniformly modified, and the said area | region can be made smooth.

  Further, in the method for manufacturing the electricity storage device 10, the second laser beam 600 is irradiated so that the center Q of the second laser beam 600 moves around the outer periphery of the liquid filling plug 400. Thereby, according to the manufacturing method of the electrical storage element 10, laser welding can be performed over the entire outer periphery of the liquid filling plug 400 to the container surface 110b that has been smoothened by surface modification.

  Moreover, according to the electrical storage element 10 which concerns on embodiment of this invention, the 1st laser beam 500 weaker than the 2nd laser beam 600 irradiated by laser welding is irradiated adjacent to the welding part 631 in the container surface 110b. As a result, a laser irradiation mark 511 modified so as to make the container surface 110b smooth is formed. As described above, since the region where the liquid injection stopper 400 on the surface 110b of the container is welded is modified so as to be smooth and laser-welded, welding of the liquid injection stopper 400 to the container 100 is performed in a stable state. The power storage element 10 is realized. Thereby, according to the electrical storage element 10, when welding the liquid injection stopper 400 to the container 100, the welding operation can be performed smoothly.

  Further, in the electric storage element 10, a laser irradiation mark 511 is formed over the entire periphery so as to surround the welded portion 631 formed over the entire outer periphery of the liquid filling plug 400. As described above, since the entire region to which the liquid injection stopper 400 is welded is uniformly smoothed and laser-welded, the electricity storage device 10 that has been stably welded to the container 100 can be obtained. It has been realized.

  The power storage element 10 and the manufacturing method thereof according to the embodiment of the present invention have been described above, but the present invention is not limited to the above embodiment. That is, the embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  For example, in the above embodiment, the liquid injection stopper 400 is disposed on the lid body 110, but the liquid injection stopper may be disposed on the main body. FIG. 11 is a diagram showing a configuration of power storage element 11 according to a modification of the embodiment of the present invention. As shown in the figure, the injection plug 700 is disposed on the side wall of the main body 113 of the container 101. In addition, the arrangement position of the liquid injection stopper 700 is not limited to the position shown in FIG. Further, the liquid injection stopper 700 may be disposed on the bottom wall of the main body 113. Also by this, the same effect as the above-mentioned embodiment can be produced.

  In the above-described embodiment, in the first irradiation step, the first laser beam 500 is positioned so that the center P of the first laser beam 500 is located in a region on the outer surface 110b of the liquid stopper 400 than the fixing portion 410. The laser beam 500 was irradiated. However, in the first irradiation step, the first laser beam 500 may be irradiated so that the center P of the first laser beam 500 is positioned on the fixed portion 410. Also by this, the welding operation can be smoothly performed by smoothing the region on the container surface 110b to which the liquid filling tap 400 is welded, as in the above embodiment.

  Moreover, in the said embodiment, in the 1st irradiation process, it decided to irradiate the 1st laser beam 500 so that at least one part of the outer edge of the 1st laser beam 500 may be located on the injection stopper 400. FIG. However, in the first irradiation step, the first laser beam 500 may be irradiated without being positioned on the liquid injection plug 400. Also by this, the welding operation can be smoothly performed by smoothing the region on the container surface 110b to which the liquid filling tap 400 is welded, as in the above embodiment.

  Moreover, in the said embodiment, in the 2nd irradiation process, it decided to irradiate the 2nd laser beam 600 so that the center Q of the 2nd laser beam 600 may be located on the injection stopper 400. FIG. However, in the second irradiation step, the second laser beam 600 may be irradiated without the center Q of the second laser beam 600 being positioned on the liquid injection plug 400.

  The present invention can be applied to a method for manufacturing a storage element such as a lithium ion secondary battery.

10, 11 Storage element 100, 101 Container 110, 112 Lid 110a Injection port 110b Container surface 111, 113 Main body 120 Positive electrode current collector 130 Negative electrode current collector 140 Electrode body 200 Positive electrode terminal 300 Negative electrode terminal 400, 700 Injection plug 410 Fixed portion 420 Protruding portion 500 First laser beam 501 and 601 Movement locus 510, 510a, 511, 520, 520a Laser irradiation mark 530, 530a First region 600 Second laser beam 610a, 620a Welded region 630, 630a Second region 631 Welded part

Claims (7)

A method for producing an electricity storage element, wherein an electricity storage element is produced by welding an injection stopper to a container surface of a container in which an injection port for injecting an electrolyte is formed,
An injection stopper arrangement step of arranging the injection stopper on the surface of the container so as to close the injection hole;
A first irradiating step of irradiating a first laser beam to a first region including a region where the liquid stopper is welded on the surface of the container in a state where the liquid stopper is disposed on the surface of the container;
By irradiating a second laser beam, which is stronger than the first laser beam, on a second region including a region on the liquid stopper with the liquid stopper being disposed on the surface of the container, A second irradiation step of laser welding the liquid injection stopper,
In the first irradiating step, the first laser beam having a strength that makes the surface of the container smooth is irradiated. In the first irradiation step, the first laser beam is located in the first region so that the center of the first laser beam is located in a region outside the region where the liquid stopper is disposed on the surface of the container. Irradiate
2. The method for manufacturing a storage element according to claim 1, wherein, in the second irradiation step, the second region is irradiated with the second laser beam such that a center of the second laser beam is positioned on the liquid injection stopper. . Wherein in the first irradiation step, so that at least a portion of the outer edge of the first laser beam is located on the pouring plug according to claim 1 or 2 is irradiated with the first laser beam to the first region A method for manufacturing the electricity storage device. Wherein in the first irradiation step, the outside of center the pouring plug of the first laser beam to move over the entire circumference, according to claim 1 to 3 for irradiating the first laser beam to the first region The manufacturing method of the electrical storage element of any one. And in the second irradiation step, the center of the second laser beam to move the outer peripheral portion of the pouring plug over the entire circumference, according to claim 1-4 for irradiating the second laser beam to the second region The manufacturing method of the electrical storage element of any one. An electrical storage element comprising a container in which an injection port for injecting an electrolytic solution is formed, and an injection plug arranged to close the injection port,
Includes a welded portion formed by said by pouring stopper is laser welded to the container surface of the container,
The outer surface of the welded part adjacent to the welded part on the container surface is formed more smoothly than the inner surface of the welded part adjacent to the welded part on the container surface .
A charge reservoir element. The weld is formed on the outer periphery of the liquid stopper over the entire circumference,
The electric storage element according to claim 6 , wherein the outer surface is formed over the entire circumference so as to surround the welded portion.

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