Manufacturing method for energy storage devices

Abstract

To provide a method for manufacturing a power storage device that can suppress the occurrence of burnt areas in a resin member that provides insulation between the periphery of an insertion hole in a case lid member and a terminal member when forming a case by laser welding.SOLUTION: A manufacturing method of a power storage device 1 includes a laser welding step S3 of irradiating the entire circumference of an opening 20c of a case body member 20 and the peripheral portion 30f of a case lid member 30 with laser light LC with the opening 20c of the case body member 20 being blocked by the case lid member 30 of a lid assembly 15 to perform laser welding, a shielding step S2 of disposing shielding members SA, SB in the lid assembly 15 to prevent scattered light LB of the laser light LC from reaching the resin members 70, 80 prior to the laser welding step S3, and a removal step S4 of removing the shielding members SA, SB after the laser welding step S3.SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a power storage device including a case in which a case lid member is welded to a case body member, a terminal member inserted into an insertion hole of the case lid member, and a resin member that insulates between the peripheral portion of the insertion hole of the case lid member and the terminal member, joins them, and fixes the terminal member to the case lid member.

Background Art

[0002] As a power storage device, a rectangular battery in which positive and negative terminal members are respectively fixed to a rectangular parallelepiped box-shaped case via a resin member is known. Specifically, the case includes a bottomed rectangular tubular case body member having a rectangular opening, and a rectangular plate-shaped case lid member welded to the case body member over the entire circumference in a form that closes the opening. The positive and negative terminal members are respectively inserted into insertion holes provided in the case lid member and extend from the inside of the case to the outside of the case. The resin member insulates between the peripheral portion of the insertion hole of the case lid member and the positive and negative terminal members, respectively, and hermetically joins them to fix the positive and negative terminal members to the case lid member. Such a battery is disclosed in, for example, Patent Document 1 (see FIGS. 1, FIGS. 2, etc.).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] These batteries are manufactured as follows: Terminal members are fixed to a case lid member via a resin member using methods such as insert molding or crimping, forming an integrated lid assembly. Next, the case lid member of this lid assembly closes the opening of the case body member, and the opening of the case body member and the periphery of the case lid member are laser-welded around the entire circumference to form the case. After that, the battery is completed by pouring electrolyte into the case. However, during the aforementioned laser welding process, scattered laser light can reach the resin component that insulates the case lid and terminal components, potentially causing charring on the resin component.

[0005] The present invention has been made in view of the current situation, and provides a method for manufacturing an energy storage device that can suppress the occurrence of charring in the resin member that insulates the area around the insertion hole of the case lid member and the terminal member when forming a case by laser welding the case body member and the case lid member. [Means for solving the problem]

[0006] (1) One aspect of the present invention for solving the above problems is a method for manufacturing an energy storage device comprising: a case having a bottomed cylindrical case body member having an opening, and a case lid member having an insertion hole and welded around the entire circumference of the case body member in a manner that closes the opening; a terminal member inserted into the insertion hole of the case lid member; a portion of the case lid member surrounding the insertion hole and a resin member that insulates between them and the terminal member, and joins them to fix the terminal member to the case lid member, wherein the resin A lid assembly in which the terminal member is integrated via a member comprises a laser welding step of forming the case by irradiating the opening of the case body member and the peripheral edge of the case lid member with laser light over the entire circumference and laser welding the case with the case lid member covering the opening of the case body member, and prior to the laser welding step, a shielding step of placing a shielding member in the lid assembly to prevent scattered laser light from reaching the resin member, and a removal step of removing the shielding member after the laser welding step, wherein the shielding member is The shielding member itself undergoes elastic deformation, thereby elastically gripping the resin member or the terminal member of the lid assembly. This is a method for manufacturing an energy storage device that is configured to be temporarily fixed to and detachable from the resin member or the terminal member.

[0007] In the manufacturing method of the energy storage device described above, prior to the laser welding process in which the case body member and the case lid member are laser-welded, the shielding member is placed on the lid assembly in a shielding process. This makes it difficult for scattered laser light to reach the resin member during laser welding in the laser welding process, thereby suppressing the occurrence of charring on the resin member. Furthermore, since the shielding member has the detachable configuration described above, the shielding member itself can be temporarily fixed to the resin member or terminal member. This prevents the shielding member from shifting from its predetermined position on the lid assembly or from separating from the lid assembly when transporting the lid assembly in which the shielding member is placed, thus making it easier to handle the lid assembly in which the shielding member is placed.

[0008] Examples of "energy storage devices" include secondary batteries such as lithium-ion secondary batteries, sodium-ion secondary batteries, and calcium-ion secondary batteries, as well as capacitors such as lithium-ion capacitors. Examples of "shielding members" include shielding members made of metal or shielding members made of ceramic. The shielding member may be in a form that covers the entire outer part of the resin member located on the outside of the case lid member in the lid thickness direction, or it may be in a form that covers only a part of the outer part of the resin member. Alternatively, the shielding member may be in a wall-like (screen-like) form that is placed between the resin member and the peripheral edge of the case lid member. The "resin member" may be a resin member that is insert-molded with the terminal member inserted into the insertion hole of the case lid member, or it may be a resin member that is formed separately from the case lid member and the terminal member and is crimped and fixed together with the case lid member by the terminal member.

[0009] (2) A method for manufacturing an energy storage device as described in (1), wherein the wavelength λ of the laser light is 0.5 μm or more, and the shielding member has an Ag plating layer in the area where the scattered light of the laser light reaches.

[0010] Silver (Ag) is less likely to absorb laser light with a wavelength λ of 0.5 μm or longer compared to iron (Fe) or aluminum (Al), and is less likely to dissolve even when scattered laser light reaches it. Therefore, as described above, by providing an Ag plating layer in the part of the shielding material that is reached by scattered laser light, the shielding material becomes less likely to dissolve due to scattered laser light, and thus the shielding material can be reused repeatedly.

[0011] (3) The method for manufacturing an energy storage device as described in (1), wherein the wavelength λ of the laser light is 0.9 μm or more, and the shielding member is made of Cu in the portion where the scattered light of the laser light reaches.

[0012] Compared to Fe and Al, copper (Cu) is less likely to absorb laser light with a wavelength λ of 0.9 μm or longer, and is less likely to dissolve even when scattered laser light reaches it. Therefore, as described above, by forming the part of the shielding member that receives scattered laser light with Cu, the shielding member becomes less likely to dissolve due to scattered laser light, and thus the shielding member can be reused repeatedly.

[0015] ( 4 )( 1 A method for manufacturing an energy storage device as described in () is preferable, wherein the shielding member is made by bending a metal plate material.

[0016] Since the shielding member is made by bending a metal plate, it can be made into an inexpensive shielding member.

[0017] ( 5 )(1)~( 4 A method for manufacturing an energy storage device as described in any of the above, wherein the case lid member is a rectangular plate shape extending in the longitudinal direction of the lid, and the outer resin portion of the resin member located on the outside in the thickness direction of the lid has an outer shape of a rectangular plate and has a top surface facing outward in the thickness direction of the lid, a pair of long sides that are aligned with the longitudinal direction of the lid and facing the short direction of the lid, and a pair of short sides that are aligned with the short direction of the lid and facing the longitudinal direction of the lid, and the shielding member has a form that prevents the scattered light of the laser light from reaching the pair of long sides of the resin member.

[0018] As described above, when the case lid member is a rectangular plate extending in the longitudinal direction of the lid, and the resin outer part of the resin member has a top surface, a pair of long sides, and a pair of short sides, the distance from the area irradiated by the laser beam to the long sides of the resin member tends to be short. As a result, high-intensity scattered light easily reaches the long sides of the resin member, and charring is likely to occur on the long sides. In contrast, in the manufacturing method described above, the shielding member has a shape that prevents scattered laser light from reaching the pair of long sides of the resin member, thus suppressing the occurrence of charring on the long sides of the resin member.

[0019] ( 6 )( 5 A method for manufacturing an energy storage device as described in () is preferable, wherein the shielding member has a form that is longer in the longitudinal direction of the lid than the long side surface of the resin member.

[0020] Since the shielding member has a shape that is longer in the lid longitudinal direction than the long side surface of the resin member, it is possible to more appropriately prevent the scattered light of the laser light from reaching the long side surface of the resin member in the laser welding process, and to more appropriately suppress the occurrence of burnt portions on the long side surface of the resin member.

Brief Description of the Drawings

[0021] [Figure 1] It is a perspective view of the battery according to the embodiment. [Figure 2] It is a partial broken cross-sectional view along the battery height direction and the battery width direction of the battery according to the embodiment. [Figure 3] It is a partially enlarged cross-sectional view along the battery height direction and the battery width direction in the vicinity of the resin member of the battery according to the embodiment. [Figure 4] It is a flowchart of the manufacturing method of the battery according to the embodiment. [Figure 5] It is an explanatory diagram showing the lid assembly regarding the manufacturing method of the battery according to the embodiment. [Figure 6] It is a perspective view of the shielding member regarding the manufacturing method of the battery according to the embodiment. [Figure 7] It is an explanatory diagram showing a state where the shielding member is arranged on the lid assembly in the shielding process regarding the manufacturing method of the battery according to the embodiment, (a) is an explanatory diagram seen in the lid short side direction, and (b) is an explanatory diagram seen in the lid long side direction. [Figure 8] It is an explanatory diagram showing a state where the shielding member is arranged and the opening of the case main body member and the peripheral edge of the case lid member are laser welded in the laser welding process regarding the manufacturing method of the battery according to the embodiment.

Mode for Carrying Out the Invention

[0022] (Embodiment) Hereinafter, embodiments of the present invention will be described with reference to the drawings. Figure 1 shows a perspective view of the battery (energy storage device) 1 according to this embodiment, and Figure 2 shows a partially broken cross-sectional view of the battery 1. Figure 3 shows a partially enlarged cross-sectional view of the battery 1 near the resin members 70 and 80. In the following description, the battery height direction AH, battery width direction BH, battery thickness direction CH of the battery 1, and the lid longitudinal direction DH, lid short direction EH, and lid thickness direction FH of the case lid member 30 will be defined as the directions shown in Figures 1 to 3.

[0023] This battery 1 is a prismatic (rectangular) sealed lithium-ion secondary battery installed in vehicles such as hybrid cars, plug-in hybrid cars, and electric vehicles. The battery 1 consists of a case 10, an electrode body 40 housed inside the case 10, a positive electrode terminal member 50 fixed to the case 10 via a resin member 70, and a negative electrode terminal member 60 fixed to the case 10 via a resin member 80. Inside the case 10, the electrode body 40 is covered by a bag-shaped insulating holder 7 made of insulating film. The case 10 also contains an electrolyte 5, some of which is impregnated into the electrode body 40, and the remainder which accumulates on the bottom wall of the case 10.

[0024] The case 10 is a rectangular box made of metal (aluminum in this embodiment), and is a bottomed rectangular tube with a rectangular opening 20c. It consists of a case body member 20 that houses the electrode body 40 inside, and a rectangular plate-shaped case lid member 30 that closes the opening 20c of the case body member 20. The opening 20c of the case body member 20 and the peripheral edge 30f of the case lid member 30 are airtightly welded around the entire circumference, and a molten solidified portion 25 is formed between the case body member 20 and the case lid member 30. The case lid member 30 of case 10 is provided with a safety valve 11 that breaks and opens when the internal pressure of case 10 exceeds the opening pressure. The case lid member 30 is also provided with a liquid injection hole 30k that penetrates the case lid member 30 in the lid thickness direction FH, and this liquid injection hole 30k is airtightly sealed with a disc-shaped sealing member 12 made of aluminum.

[0025] The electrode body 40 housed in case 10 is rectangular parallelepiped and stacked, with multiple positive electrode plates 41 and multiple negative electrode plates 42 alternately stacked in the battery thickness direction CH via separators 43 made of a porous resin membrane. The positive electrode plates 41, negative electrode plates 42, and separators 43 are rectangular in shape, expanding in the battery height direction AH and the battery width direction BH, respectively. The positive electrode plate 41 consists of a positive electrode current collector foil made of aluminum foil and positive electrode active material layers containing positive electrode active material particles formed on both main surfaces of the positive electrode current collector foil. A portion of the positive electrode current collector foil extends to one side BH1 in the battery width direction BH, and is an exposed positive electrode foil portion where the positive electrode active material layer is absent on both sides. The exposed positive electrode foil portions of each positive electrode plate 41 overlap in the foil thickness direction to form a positive electrode current collector portion 40c. This positive electrode current collector portion 40c is electrically connected to the positive electrode terminal member 50, which will be described later.

[0026] The negative electrode plate 42 consists of a negative electrode current collector foil made of copper foil and negative electrode active material layers containing negative electrode active material particles formed on both main surfaces of the negative electrode current collector foil. A portion of the negative electrode current collector foil extends to the other side BH2 in the battery width direction BH, and is an exposed negative electrode foil portion where the negative electrode active material layer is absent on both sides. The exposed negative electrode foil portions of each negative electrode plate 42 overlap in the foil thickness direction to form a negative electrode current collector portion 40d. This negative electrode current collector portion 40d is electrically connected to the negative electrode terminal member 60, which will be described later.

[0027] In the case lid member 30, rectangular through holes 30h1 and 30h2 are provided near the ends of one side DH1 and the other side DH2 in the longitudinal direction DH of the lid (one side BH1 and the other side BH2 in the battery width direction BH), respectively, penetrating the case lid member 30 in the thickness direction FH. A positive electrode terminal member 50 made of aluminum is inserted into one of the through holes 30h1, and the terminal member 50 is fixed to the case lid member 30 while being insulated from the case lid member 30 via a resin member 70. A negative electrode terminal member 60 made of copper is inserted into the other through hole 30h2, and the terminal member 60 is fixed to the case lid member 30 while being insulated from the case lid member 30 via a resin member 80.

[0028] The terminal members 50 and 60 are made by press-forming metal plates (aluminum plate for the positive electrode and copper plate for the negative electrode). These terminal members 50 and 60 are located on the outer side FH1 (upper side AH1 of the battery height direction AH) of the case lid member 30 in the lid thickness direction FH, and consist of rectangular plate-shaped terminal top portions 51 and 61 that extend in the lid longitudinal direction DH (battery width direction BH) and the lid short direction EH (battery thickness direction CH), and terminal extension portions 52 and 62 that extend from these terminal top portions 51 and 61 to the inner side FH2 (lower side AH2 of the battery height direction AH) in the lid thickness direction FH. The terminal extensions 52 and 62 bend at the end of one side EH1 (one side CH1 in the battery thickness direction CH) of the terminal top plate portion 51 and 61 in the lid's short-side direction EH, extend inward FH2 in the lid's thickness direction FH, pass through the insertion holes 30h1 and 30h2 of the case lid member 30, and further penetrate the resin members 70 and 80 to extend to the lower AH2. The positive terminal extension 52 is welded to the positive electrode current collector portion 40c of the electrode body 40 at the tip of the lower AH2, and is electrically connected to the positive electrode current collector portion 40c. The negative terminal extension 62 is welded to the negative electrode current collector portion 40d of the electrode body 40 at the tip of the lower AH2, and is electrically connected to the negative electrode current collector portion 40d.

[0029] Next, the resin members 70 and 80 will be described. These resin members 70 and 80 are insert-molded using a resin material containing a thermoplastic main resin (specifically, polyphenylene sulfide (PPS)), a thermoplastic elastomer, and a filler (specifically, fibrous glass filler). The resin members 70 and 80 insulate the surrounding portions 30s1 and 30s2 of the case lid member 30 that surround the insertion holes 30h1 and 30h2 from the terminal members 50 and 60, while airtightly joining them to the surrounding portions 30s1 and 30s2 of the case lid member 30 and the terminal members 50 and 60, thereby fixing the terminal members 50 and 60 to the case lid member 30.

[0030] The resin members 70 and 80 consist of outer resin portions 71 and 81 located on the outside FH1 in the lid thickness direction FH of the case lid member 30, and inner resin portions 72 and 82 located inside the insertion holes 30h1 and 30h2 of the case lid member 30 and on the inside FH2 in the lid thickness direction FH of the case lid member 30, and are integrally connected with the outer resin portions 71 and 81. The outer resin parts 71 and 81 have a rectangular plate shape and include a rectangular band-shaped top surface 71m1 and 81m1 facing outward FH1 in the lid thickness direction FH, a pair of rectangular long sides 71m2 and 81m2 that are aligned with the lid longitudinal direction DH and facing the lid short direction EH, and a pair of rectangular short sides 71m3 and 81m3 that are aligned with the lid short direction EH and facing the lid longitudinal direction DH. The outer surfaces 70m and 80m of the resin members 70 and 80 that are exposed to the outside of the case 10 are composed of these top surfaces 71m1 and 81m1, the pair of long sides 71m2 and 81m2, and the pair of short sides 71m3 and 81m3. In the battery 1 of this embodiment, no charring occurs on any part of the outer surface 70m, 80m of the resin members 70, 80 (top surface 71m1, 81m1, long side surface 71m2, 81m2, and short side surface 71m3, 81m3).

[0031] Next, the manufacturing method of the battery 1 will be described (see Figures 4 to 8). First, in the "lid assembly forming process S1" (see Figure 4), the lid assembly 15 is formed (see Figure 5). That is, a case lid member 30 and terminal members 50 and 60 are prepared, and resin members 70 and 80 are insert-molded to fix the terminal members 50 and 60 to the case lid member 30 via the resin members 70 and 80. The case lid member 30 is obtained by punching an aluminum plate into a predetermined shape and forming an electrolyte injection hole 30k, insertion holes 30h1 and 30h2, and a safety valve 11 therein. The positive electrode terminal member 50 is obtained by punching an aluminum plate into a predetermined shape and bending it. The negative electrode terminal member 60 is obtained by punching a copper plate into a predetermined shape and bending it.

[0032] Then, with the terminal members 50 and 60 inserted into the insertion holes 30h1 and 30h2 of the case lid member 30, the resin members 70 and 80 are insert-molded using the aforementioned resin material, and the terminal members 50 and 60 are fixed to the case lid member 30 via the resin members 70 and 80 (see Figure 5). Subsequently, an electrode body 40 is prepared by laminating a positive electrode plate 41, a negative electrode plate 42, and a separator 43. The terminal extension 52 of the positive electrode terminal member 50 is welded to the positive electrode current collector portion 40c of the electrode body 40. The terminal extension 62 of the negative electrode terminal member 60 is welded to the negative electrode current collector portion 40d of the electrode body 40. After that, the electrode body 40 is wrapped in a bag-shaped insulating holder 7. Thus, a lid assembly 15 is formed having a case lid member 30, terminal members 50, 60, resin members 70, 80, the electrode body 40, and the insulating holder 7.

[0033] Next, in the "shielding process S2" (see Figure 4), a shielding member SA is placed in the lid assembly 15 to prevent the scattered light LB of the laser beam LC from reaching the resin members 70 and 80 in the laser welding process S3, which will be described later (see Figures 6 and 7). First, the shielding member SA will be described. This shielding member SA is made by bending a rectangular metal plate MA, which has an Ag plating layer MAd formed on the entire surface of the stainless steel plate MAc. Therefore, in the shielding member SA of this embodiment, the Ag plating layer MAd is present on the entire surface of the shielding member SA, including the part SAp to which the scattered light LB of the laser beam LC reaches in the laser welding process S3, which will be described later.

[0034] The shielding member SA is configured to be detachable from the resin members 70 and 80 of the lid assembly 15. The shielding member SA has a shape that prevents scattered light LB of the laser light LC from reaching a pair of long sides 71m2 and 81m2 of the resin members 70 and 80, and further has a shape that is longer in the longitudinal direction DH of the lid than the long sides 71m2 and 81m2 of the resin members 70 and 80. Specifically, the shielding member SA consists of a pair of side wall portions SA1 that cover the pair of long sides 71m2 and 81m2 of the resin members 70 and 80, and a connecting portion SA2 that connects the side wall portions SA1 and is positioned on the outside FH1 in the lid thickness direction FH of the top surfaces 71m1 and 81m1 of the resin members 70 and 80.

[0035] Of these, the side wall portion SA1 is a rectangular plate that covers the entire length of the long sides 71m2 and 81m2 of the resin members 70 and 80, and its length DH is longer than the length DH of the long sides 71m2 and 81m2 of the lid (see Figure 7(b)). The connecting portion SA2 is bent at multiple points and has two protruding portions SA3 that are in an inverted V shape and project outward FH1 in the lid thickness direction FH, a pair of first flat plate portions SA4 that connect the side wall portion SA1 and the protruding portions SA3 respectively, and a second flat plate portion SA5 that connects the two protruding portions SA3. The first flat plate portions SA4 and the second flat plate portions SA5 are rectangular plates that are aligned with the top surfaces 71m1 and 81m1 of the resin members 70 and 80.

[0036] As shown by the arrows in Figure 7(a), when the two protrusions SA3 of this shielding member SA are pressed in a direction that brings them closer together, the gap KG between the side wall portions SA1 expands, and the gap KG becomes larger than the dimension EH in the short direction of the lid of the resin members 70 and 80. On the other hand, when the above pressing is released, the gap KG between the side wall portions SA1 narrows, and the gap KG becomes smaller than the dimension EH in the short direction of the lid of the resin members 70 and 80. Therefore, in the shielding process S2, the two protrusions SA3 of the shielding member SA are pressed in a direction that brings them closer together, and the gap KG between the side wall portions SA1 is widened, and the shielding member SA is placed over the resin members 70 and 80. After that, when the pressure is released, the gap KG between the side wall portions SA1 narrows, and the pair of side wall portions SA1 elastically grip the resin members 70 and 80 in the short-side direction EH of the lid. As a result, the shielding member SA is temporarily fixed to the resin members 70 and 80 of the lid assembly 15.

[0037] Next, in the "laser welding process S3" (see Figure 4), the case body member 20 is prepared, and the electrode body 40 covered by the insulating holder 7 from the aforementioned lid assembly 15 is inserted into the case body member 20, and the opening 20c of the case body member 20 is closed with the case lid member 30 (see Figure 8). Then, the opening 20c of the case body member 20 and the peripheral edge 30f of the case lid member 30 are irradiated with laser light LC all around, and laser welding is performed to form a case 10 in which the electrode body 40 is housed inside.

[0038] Specifically, using a fiber laser, laser light LC with a wavelength λ of 1.06 μm is irradiated from the outer side FH1 in the lid thickness direction FH of the case lid member 30 to the opening 20c of the case body member 20 and the peripheral edge 30f of the case lid member 30. Laser welding is performed all around to melt, mix, and then solidify the opening 20c and the peripheral edge 30f to form a molten and solidified portion 25, thereby forming the case 10. In conventional methods, scattered light LB emitted from the irradiated area P of the laser beam LC directly reaches a portion of the outer surface 70m, 80m of the resin members 70, 80 (a pair of long sides 71m2, 81m2 and a pair of short sides 71m3, 81m3), making it easy for charring to occur on these long sides 71m2, 81m2 and short sides 71m3, 81m3. In particular, the long sides 71m2, 81m2 are close to the irradiated area P of the laser beam LC, and high-intensity scattered light LB reaches them, making them prone to charring.

[0039] In contrast, in this embodiment, the shielding member SA covers a portion of the outer surfaces 70m and 80m of the resin members 70 and 80 (the top surface 71m1 and a pair of long sides 71m2 and 81m2). As a result, the scattered light LB of the laser beam LC does not reach the top surface 71m1 and the pair of long sides 71m2 and 81m2 of the outer surfaces 70m and 80m of the resin members 70 and 80, thus preventing charring from occurring on the top surface 71m1 and long sides 71m2 and 81m2 of the resin members 70 and 80.

[0040] Furthermore, the pair of short sides 71m3 and 81m3 of the outer surfaces 70m and 80m of the resin members 70 and 80 are not covered by the shielding member SA. However, the short sides 71m3 and 81m3 are sufficiently far from the area P irradiated by the laser light LC, and even without covering the short sides 71m3 and 81m3 with the shielding member SA, the high-intensity scattered light LB does not reach the short sides 71m3 and 81m3, so no charring occurs on the short sides 71m3 and 81m3. Consequently, no charring occurs on any part of the outer surfaces 70m and 80m of the resin members 70 and 80 (top surface 71m1, the pair of long sides 71m2 and 81m2, and the pair of short sides 71m3 and 81m3).

[0041] Next, in the "removal step S4" (see Figure 4), the shielding member SA is removed. Specifically, the two protrusions SA3 of the shielding member SA are pressed in a direction that brings them closer together, and the gap KG between the side wall portions SA1 is widened, and the shielding member SA is lifted up. This allows the shielding member SA to be easily removed from the resin members 70, 80 and the lid assembly 15.

[0042] Next, in the "liquid injection and sealing process S5" (see Figure 4), the electrolyte 5 is injected into the case 10 through the injection hole 30k, and the electrolyte 5 is impregnated into the electrode body 40. After that, the injection hole 30k is covered from the outside with a sealing member 12, and the sealing member 12 is laser-welded to the case 10 in an airtight manner. Next, in the "initial charging and aging process S6," a charging device (not shown) is connected to the battery 1, and the battery 1 is given its initial charge. After that, the initially charged battery 1 is left to stand for a predetermined time to age. Thus, the battery 1 is completed.

[0043] As explained above, in the manufacturing method of battery 1, the laser welding process S3 is performed with the shielding member SA placed in the lid assembly 15. Therefore, the scattered light LB of the laser beam LC is less likely to reach the resin members 70 and 80, and charring of the resin members 70 and 80 can be prevented. Furthermore, in this embodiment, an Ag plating layer MAd is provided on the part SAp of the shielding member SA to which the scattered light LB of the laser light LC reaches. The Ag plating layer MAd is less likely to absorb laser light LC with a wavelength λ of 0.5 μm or more, and is less likely to dissolve even when the scattered light LB of the laser light LC reaches it. As a result, the shielding member SA is less likely to dissolve due to the scattered light LB of the laser light LC, and the shielding member SA can be reused repeatedly.

[0044] Furthermore, since the shielding member SA is detachably attached to the resin members 70 and 80 of the lid assembly 15, the shielding member SA can be temporarily fixed to the resin members 70 and 80 (to the lid assembly 15) by itself. This prevents the shielding member SA from shifting from its predetermined position on the lid assembly 15 or from separating from the lid assembly 15 when transporting the lid assembly 15 with the shielding member SA in place, thus making the handling of the lid assembly 15 with the shielding member SA easier. Moreover, since this shielding member SA is made by bending a metal plate MA, it can be made into an inexpensive shielding member.

[0045] Furthermore, in this embodiment, the case lid member 30 is a rectangular plate shape extending in the longitudinal direction DH of the lid, and the resin outer parts 71, 81 of the resin members 70, 80 are rectangular plate shapes having a top surface 71m1, 81m1, a pair of long sides 71m2, 81m2, and a pair of short sides 71m3, 81m3, so the distance from the irradiated area P of the laser beam LC to the long sides 71m2, 81m2 of the resin members 70, 80 is short. For this reason, high-intensity scattered light LB can easily reach the long sides 71m2, 81m2 of the resin members 70, 80, and scorching is likely to occur on the long sides 71m2, 81m2. In contrast, in this embodiment, the shielding member SA has a shape that prevents scattered light LB from reaching the pair of long sides 71m2, 81m2 of the resin members 70, 80, so it is possible to prevent scorching from occurring on the long sides 71m2, 81m2 of the resin members 70, 80. Furthermore, since the shielding member SA has a shape that is longer in the longitudinal direction DH of the lid than the long sides 71m2 and 81m2 of the resin members 70 and 80, it is possible to more effectively prevent the scattered light LB of the laser light LC from reaching the long sides 71m2 and 81m2 of the resin members 70 and 80 during the laser welding process S3, and to more reliably prevent charring from occurring on the long sides 71m2 and 81m2 of the resin members 70 and 80.

[0046] (Transformed form) Next, a modified version of the above embodiment will be described. Note that descriptions of parts similar to those in the embodiment will be omitted or simplified. The shielding member SA used in the embodiment has an Ag plating layer MAd across its entire surface, including the portion SAp to which the scattered light LB of the laser beam LC reaches. In contrast, the shielding member SB used in this modified version differs in that the entire shielding member SB, including the portion SBp to which the scattered light LB of the laser beam LC reaches, is made of Cu.

[0047] Specifically, the shielding member SB in this modified form is made by bending a metal plate MB made of copper. However, the shape of the shielding member SB is the same as that of the shielding member SA in the embodiment. That is, the shielding member SB, like the shielding member SA, consists of a pair of side wall portions SB1 and a connecting portion SB2 (two protruding portions SB3, a pair of first flat plate portions SB4 and second flat plate portions SB5). Therefore, the shielding member SB in this modified form can be handled in the same way as the shielding member SA in the embodiment.

[0048] Even when the battery 1 is manufactured using such a shielding member SB, the shielding member SB makes it difficult for the scattered light LB of the laser beam LC to reach the resin members 70 and 80 during laser welding in the laser welding process S3, thus preventing charring of the resin members 70 and 80. Furthermore, the portion SBp of the shielding member SB to which the scattered light LB of the laser beam LC reaches is made of Cu. As a result, the shielding member SB is less likely to melt due to the scattered light LB of the laser beam LC, allowing the shielding member SB to be reused repeatedly. Other parts that are the same as in the embodiment provide the same effects and advantages as in the embodiment.

[0049] Although the present invention has been described above in reference to embodiments and modified forms, it goes without saying that the present invention is not limited to embodiments and modified forms, and can be applied with appropriate modifications without departing from the spirit of the invention. For example, in the embodiments, shielding members SA and SB are exemplified as shielding members that are detachably configured to attach to the resin members 70 and 80 of the lid assembly 15, but the invention is not limited to these. For example, if the terminal member has a terminal projection that protrudes outward in the lid thickness direction from the resin member, the shielding member may be configured to attach to the terminal projection of the terminal member of the lid assembly. [Explanation of symbols]

[0050] 1. Battery (energy storage device) 10 cases 15 Lid Assembly 20 Case body components 20c opening 30 Case lid components 30f Periphery 30h1, 30h2 Through hole 30s1, 30s2 Peripheral area of ​​the insertion hole 40 Electrode body 50, 60 Terminal members 70,80 Resin components SA, SB shielding members SAp, SBp (parts of the shielding material where scattered laser light reaches) SA1,SB1 Side wall part SA2,SB2 connection part SA3,SB3 protrusion SA4,SB4 1st flat plate part SA5,SB5 2nd flat plate part KG (Gap between side walls) MA,MB Metal plate material MAc Stainless Steel Plate MAd Ag plating layer LC laser light LB scattered light P Irradiated area S1 Lid assembly forming process S2 shielding process S3 Laser welding process S4 removal process

Claims

1. A case comprising a bottomed cylindrical case body member having an opening, and a case lid member having an insertion hole and welded around the entire circumference of the case body member in a manner that closes the opening, A terminal member inserted into the insertion hole of the case lid member, The case lid member comprises a portion surrounding the insertion hole and a resin member that insulates between them and the terminal member, and fixes the terminal member to the case lid member. A method for manufacturing an energy storage device, A lid assembly in which the terminal member is integrated with the case lid member via the resin member, comprising a laser welding step in which the case is formed by irradiating the opening of the case body member and the peripheral edge of the case lid member with laser light over the entire circumference and performing laser welding, while the opening of the case body member is closed by the case lid member, Prior to the laser welding process, a shielding step is performed in which a shielding member is placed in the lid assembly to prevent scattered laser light from reaching the resin member, The process includes a removal step after the laser welding step, where the shielding member is removed. The shielding member is configured to be able to be temporarily fixed to and detached from the resin member or terminal member of the lid assembly by elastically deforming itself and elastically gripping the resin member or terminal member of the lid assembly. A method for manufacturing energy storage devices.

2. A method for manufacturing an energy storage device according to claim 1, The wavelength λ of the laser light is 0.5 μm or greater. The shielding member has an Ag plating layer in the area where the scattered light of the laser beam reaches. A method for manufacturing energy storage devices.

3. A method for manufacturing an energy storage device according to claim 1, The wavelength λ of the laser light is 0.9 μm or greater. The shielding member is made of Cu in the area where the scattered light of the laser beam reaches. A method for manufacturing energy storage devices.

4. A method for manufacturing an energy storage device according to claim 1, The shielding member is made by bending a metal plate. A method for manufacturing energy storage devices.

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