Method for manufacturing power storage device

Abstract

The invention provides a manufacturing method of an electricity storage device, and the manufacturing method of the electricity storage device can suppress the generation of a scorched part on a resin member which insulates the periphery of an insertion hole of a housing cover member from a terminal member when a housing is formed by laser welding. A method for manufacturing a power storage device (1) is provided with: a laser welding step (S3) in which, in a cover assembly (15), in a state in which an opening (20c) of a case main body member (20) is closed by a case cover member (30), laser light (LC) is irradiated over the entire circumference of the opening (20c) of the case main body member (20) and a peripheral edge (30f) of the case cover member (30) to perform laser welding; a shielding step (S2) in which, prior to the laser welding step (S3), shielding members (SA, SB) are disposed on a lid assembly (15) that prevents scattered light (LB) of the laser light (LC) from reaching the resin members (70, 80); and a removal step (S4) for removing the shutter members (SA, SB) after the laser welding step (S3).

Description

Technical Field

[0001] The present invention relates to a method for manufacturing an electrical storage device, the electrical storage device comprising: a shell, wherein a shell cover member of the shell is welded to a shell main body member; a terminal member, the terminal member is inserted into an insertion hole of the shell cover member; and a resin member, the resin member insulates the periphery of the insertion hole of the shell cover member from the terminal member and joins them to fix the terminal member to the shell cover member. Background Art

[0002] As a power storage device, a square battery is known in which positive and negative terminal members are respectively fixed to a rectangular box-shaped shell via a resin member. Specifically, the shell is composed of a shell body member in the shape of a square tube with a bottom and a rectangular plate-shaped shell cover member, the shell body member has a rectangular opening, and the shell cover member is welded to the shell body member throughout the entire circumference in a manner to close the opening. In addition, the positive and negative terminal members are respectively inserted into insertion holes provided in the shell cover member and extend from the inside of the shell to the outside of the shell, and the resin member insulates the periphery of the insertion hole of the shell cover member from the positive and negative terminal members and air-tightly joins them, thereby fixing the positive and negative terminal members to the shell cover member. This type of battery is disclosed, for example, in Patent Document 1 (refer to Figure 1 , Figure 2 wait).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2022-079172 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] This battery is manufactured in the following manner. That is, the terminal member is fixed to the housing cover member via the resin member by insert molding, riveting, etc., to form a cover assembly that integrates them. Next, the opening of the housing body member is blocked with the housing cover member of the cover assembly, and the opening of the housing body member and the peripheral edge of the housing cover member are laser welded throughout the entire circumference to form a housing. Then, an electrolyte solution is injected into the housing to complete the battery.

[0008] However, during the above-mentioned laser welding, scattered light of the laser beam may reach the resin member that insulates the case cover member from the terminal member, and may cause a burnt portion on the resin member.

[0009] The present invention is made in view of the current situation and provides a method for manufacturing an electric storage device, which can suppress the generation of burnt portions on a resin member that insulates the periphery of an insertion hole of a case cover member and a terminal member when a case is formed by laser welding a case body member and a case cover member.

[0010] Means of solving the problem

[0011] (1) One embodiment of the present invention for solving the above-mentioned problem is a method for manufacturing an electrical storage device, the electrical storage device comprising: a case having a case body member having a bottomed cylindrical shape and a case cover member, the case body member having an opening, the case cover member having an insertion hole and being welded to the case body member over the entire circumference in a manner to close the opening; a terminal member, the terminal member being inserted into the insertion hole of the case cover member; and a resin member, the resin member insulating a portion of the case cover member surrounding the insertion hole from the terminal member and bonding them together, thereby fixing the terminal member to the case cover member. , wherein the manufacturing method of the power storage device includes: a laser welding process, in which, in a cover assembly in which the terminal member and the shell cover member are integrated via the resin member, in a state in which the opening of the shell main body member is blocked by the shell cover member, laser welding is performed on the opening of the shell main body member and the peripheral edge of the shell cover member throughout the entire circumference to form the shell; a shielding process, before the laser welding process, a shielding member is arranged on the cover assembly, and the shielding member prevents the scattered light of the laser from reaching the resin member; and a removal process, after the laser welding process, the shielding member is removed.

[0012] In the manufacturing method of the above-mentioned power storage device, before the laser welding process of laser welding the case body member and the case cover member, the above-mentioned shielding member is arranged on the cover assembly through a shielding process. As a result, during laser welding in the laser welding process, the scattered light of the laser becomes difficult to reach the resin member due to the shielding member, so that the generation of a burnt portion on the resin member can be suppressed.

[0013] Examples of the “electricity storage device” include secondary batteries such as lithium ion secondary batteries, sodium ion secondary batteries, and calcium ion secondary batteries, and capacitors such as lithium ion capacitors.

[0014] Examples of the "shielding member" include shielding members made of metal and shielding members made of ceramic. In addition, the shielding member may be a form that covers the entire resin outer portion of the resin member located outside the cover thickness direction of the housing cover member, or may be a form that covers only a portion of the resin outer portion. Alternatively, the shielding member may be a wall-like (screen-like) form disposed between the resin member and the periphery of the housing cover member.

[0015] The “resin member” may be a resin member that is insert-molded with the terminal member inserted into the insertion hole of the shell cover member, or may be a resin member that is formed separately from the shell cover member and the terminal member and is fixed by riveting the terminal member and the shell cover member together.

[0016] (2) In the method for manufacturing an electric storage device according to (1), the wavelength of the laser light may be 0.5 μm or more, and the shielding member may include an Ag plated layer at a portion where the scattered light of the laser light reaches.

[0017] Compared with iron (Fe) and aluminum (Al), silver (Ag) is less likely to absorb laser light with a wavelength of 0.5 μm or more, and is less likely to melt even if the scattered light of the laser reaches it. Therefore, as described above, by providing an Ag plating layer at the portion of the shielding member where the scattered light of the laser reaches, the shielding member is less likely to melt due to the scattered light of the laser, and thus the shielding member can be reused.

[0018] (3) In the method for manufacturing an electrical storage device according to (1), the wavelength of the laser light may be 0.9 μm or more, and a portion of the shielding member where the scattered light of the laser light reaches may be made of Cu.

[0019] Compared with Fe and Al, copper (Cu) is less likely to absorb laser light with a wavelength of 0.9 μm or more, and is less likely to melt even if the scattered light of the laser reaches it. Therefore, as described above, by forming the shielding member with Cu as the portion where the scattered light of the laser reaches, the shielding member is less likely to be melted by the scattered light of the laser, and thus the shielding member can be reused.

[0020] (4) In the method for manufacturing an electrical storage device according to any one of (1) to (3), the shielding member may be configured to be detachably mounted on the resin member or the terminal member in the cover assembly.

[0021] Since the shielding member has the above-mentioned structure that can be detachably mounted, the shielding member can be temporarily fixed to the resin member or the terminal member by the shielding member itself. Therefore, when the cover assembly equipped with the shielding member is transported, for example, the shielding member can be prevented from being displaced from a predetermined position of the cover assembly or being separated from the cover assembly, so that the cover assembly equipped with the shielding member can be easily handled.

[0022] (5) In the method for manufacturing an electric storage device according to (4), the shielding member may be produced by bending a metal plate.

[0023] Since the shielding member is manufactured by bending a metal plate, it can be an inexpensive shielding member.

[0024] (6) Preferably, a method for manufacturing an electrical storage device according to any one of (1) to (5), wherein the shell cover member is in the shape of a rectangular plate extending in the long side direction of the cover, and in the resin member, the outer shape of the resin outer portion located outside the shell cover member in the cover thickness direction is in the shape of a rectangular plate, and the resin outer portion has: a top surface facing the outside in the cover thickness direction; a pair of long side surfaces, the pair of long side surfaces are along the long side direction of the cover and face opposite sides to each other in the short side direction of the cover; and a pair of short side surfaces, the pair of short side surfaces are along the short side direction of the cover and face opposite sides to each other in the long side direction of the cover, and the shielding member has a shape that prevents the scattered light of the laser from reaching the pair of long side surfaces in the resin member.

[0025] As described above, when the housing cover member is in the shape of a rectangular plate extending in the long side direction of the cover, and the resin outer side portion of the resin member has a top surface, a pair of long side surfaces, and a pair of short side surfaces, since the distance from the laser irradiated portion to the long side surfaces of the resin member is likely to be shortened, high-intensity scattered light is likely to reach the long side surfaces of the resin member, and burnt portions are likely to be generated on the long side surfaces. In contrast, in the above-mentioned manufacturing method, since the shielding member has a method of preventing the scattered light of the laser from reaching the pair of long side surfaces of the resin member, the generation of burnt portions on the long side surfaces of the resin member can be suppressed.

[0026] (7) In the method for manufacturing an electric storage device according to (6), the shielding member may be longer in the cover longitudinal direction than the long side surface of the resin member.

[0027] Since the shielding member is longer in the long side direction of the cover than the long side of the resin member, it can more appropriately prevent the scattered light of the laser from reaching the long side of the resin member during the laser welding process, and can more appropriately suppress the generation of burnt portions on the long side of the resin member. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a perspective view of a battery according to an embodiment.

[0029] Figure 2 It is a partially cut-away cross-sectional view of the battery according to the embodiment along the battery height direction and the battery width direction.

[0030] Figure 3 It is a partial enlarged cross-sectional view of the vicinity of a resin member in the battery of the embodiment, taken along the battery height direction and the battery width direction.

[0031] Figure 4 This is a flowchart of a method for manufacturing a battery according to an embodiment.

[0032] Figure 5 It is an explanatory diagram showing a cover assembly related to the method for manufacturing a battery according to the embodiment.

[0033] Figure 6 This is a perspective view of a shielding member related to the battery manufacturing method according to the embodiment.

[0034] Fig. 7A This is an explanatory diagram related to the battery manufacturing method according to the embodiment, and shows a state where a shielding member is arranged on a cover assembly in a shielding step, and is an explanatory diagram viewed from the short side direction of the cover.

[0035] Figure 7B This is an explanatory diagram related to the battery manufacturing method according to the embodiment, and shows a state where a shielding member is arranged on a cover assembly in a shielding step, and is an explanatory diagram viewed from the long side direction of the cover.

[0036] Figure 8 This is an explanatory diagram related to the battery manufacturing method according to the embodiment, showing a state in which the opening portion of the case body member and the peripheral edge portion of the case lid member are laser welded in a laser welding step in a state in which a shielding member is arranged. DETAILED DESCRIPTION

[0037] (Implementation Method)

[0038] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Figure 1 A perspective view showing a battery (electricity storage device) 1 according to this embodiment, Figure 2 1 is a partially cutaway cross-sectional view of the battery 1. Figure 3 FIG. 1 is a partial enlarged cross-sectional view of the vicinity of the resin members 70 and 80 in the battery 1. In the following, the battery height direction AH, the battery width direction BH, the battery thickness direction CH of the battery 1, and the cover long side direction DH, the cover short side direction EH, and the cover thickness direction FH of the case cover member 30 are set as Figure 1 to Figure 3 The directions shown are used for illustration.

[0039] The battery 1 is a square (rectangular) sealed lithium-ion secondary battery mounted on a hybrid vehicle, a plug-in hybrid vehicle, an electric vehicle, or other vehicles. The battery 1 is composed of a housing 10, an electrode body 40 housed in the housing 10, a positive terminal member 50 fixed to the housing 10 via a resin member 70, and a negative terminal member 60 fixed to the housing 10 via a resin member 80. The electrode body 40 is covered by a bag-shaped insulating retainer 7 composed of an insulating film in the housing 10. In addition, an electrolyte 5 is contained in the housing 10, a portion of the electrolyte 5 is impregnated into the electrode body 40, and the rest is accumulated on the bottom wall of the housing 10.

[0040] The case 10 is a rectangular box made of metal (aluminum in this embodiment), and is composed of a case body member 20 in the shape of a square tube with a bottom and a case cover member 30 in the shape of a rectangular plate. The case body member 20 has a rectangular opening 20c, and the electrode body 40 is accommodated therein. The case cover member 30 blocks 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 cover member 30 are airtightly welded throughout the entire circumference, and a melt-solidified portion 25 is formed between the case body member 20 and the case cover member 30.

[0041] The housing cover member 30 of the housing 10 is provided with a safety valve 11, which ruptures and opens when the internal pressure of the housing 10 exceeds the valve opening pressure. In addition, the housing cover member 30 is provided with a liquid injection hole 30k that penetrates the housing cover member 30 in the cover thickness direction FH, and the liquid injection hole 30k is hermetically sealed by a disk-shaped sealing member 12 made of aluminum.

[0042] The electrode body 40 accommodated in the housing 10 is a rectangular parallelepiped and is a stacked type, which is formed by alternately stacking a plurality of positive plates 41 and a plurality of negative plates 42 in the battery thickness direction CH via a separator 43 composed of a porous film made of resin. The positive plate 41, the negative plate 42 and the separator 43 are rectangular shapes that expand in the battery height direction AH and the battery width direction BH, respectively.

[0043] The positive electrode plate 41 is composed of a positive electrode collector foil and a positive electrode active material layer. The positive electrode collector foil is made of aluminum foil. The positive electrode active material layer is formed on the two main surfaces of the positive electrode collector foil, respectively, and contains positive electrode active material particles. A part of the positive electrode collector foil extends out on one side BH1 in the battery width direction BH, forming a positive electrode foil exposed portion on both sides of which there is no positive electrode active material layer. Moreover, the positive electrode foil exposed portions of each positive electrode plate 41 overlap in the foil thickness direction to form a positive electrode collector portion 40c. The positive electrode collector 40c is conductively connected to the terminal member 50 of the positive electrode described later.

[0044] In addition, the negative electrode plate 42 is composed of a negative electrode collector foil and a negative electrode active material layer, wherein the negative electrode collector foil is composed of copper foil, and the negative electrode active material layer is respectively formed on the two main surfaces of the negative electrode collector foil, and contains negative electrode active material particles. A portion of the negative electrode collector foil extends out on the other side BH2 in the battery width direction BH, forming a negative electrode foil exposure portion exposed on both sides thereof without the negative electrode active material layer. Moreover, the negative electrode foil exposure portions of each negative electrode plate 42 overlap in the foil thickness direction to form a negative electrode collector portion 40d. The negative electrode collector 40d is electrically connected to the terminal member 60 of the negative electrode described later.

[0045] In the case cover member 30, rectangular insertion holes 30h1 and 30h2 are respectively provided near the ends on one side DH1 and the other side DH2 in the cover longitudinal direction DH (one side BH1 and the other side BH2 in the battery width direction BH) that penetrate the case cover member 30 in the cover thickness direction FH. A positive electrode terminal member 50 made of aluminum is inserted into the insertion hole 30h1 on one side, and the terminal member 50 is fixed to the case cover member 30 in a state of being insulated from the case cover member 30 via the resin member 70. In addition, a negative electrode terminal member 60 made of copper is inserted into the insertion hole 30h2 on the other side, and the terminal member 60 is fixed to the case cover member 30 in a state of being insulated from the case cover member 30 via the resin member 80.

[0046] The terminal members 50, 60 are formed by stamping metal plates (aluminum plates for the positive electrode and copper plates for the negative electrode). These terminal members 50, 60 are composed of rectangular plate-shaped terminal top plates 51, 61 and terminal extensions 52, 62, wherein the terminal top plates 51, 61 are located on the outer side FH1 in the cover thickness direction FH (the upper side AH1 in the battery height direction AH) of the housing cover member 30, and expand in the cover long side direction DH (battery width direction BH) and the cover short side direction EH (battery thickness direction CH), and the terminal extensions 52, 62 extend from the terminal top plates 51, 61 to the inner side FH2 in the cover thickness direction FH2 (the lower side AH2 in the battery height direction AH). The terminal extensions 52 and 62 are bent at the end of the terminal top plate portions 51 and 61 on one side EH1 in the cover short side direction EH (one side CH1 in the battery thickness direction CH), and extend inward in the cover thickness direction FH, through the insertion holes 30h1 and 30h2 of the case cover member 30, and further penetrate the resin members 70 and 80 and extend toward the lower side AH2. The positive terminal extension 52 is welded to the positive electrode collector 40c of the electrode body 40 at the front end on the lower side AH2, and is electrically connected to the positive electrode collector 40c. In addition, the negative terminal extension 62 is welded to the negative electrode collector 40d of the electrode body 40 at the front end on the lower side AH2, and is electrically connected to the negative electrode collector 40d.

[0047] Next, the resin members 70 and 80 are described. The resin members 70 and 80 are insert-molded from a resin material containing a thermoplastic main resin (specifically, polyphenylene sulfide (PPS)), a thermoplastic elastomer, and a filler (specifically, a glass fiber-like filler). The resin members 70 and 80 insulate the insertion hole surrounding portions 30s1 and 30s2 surrounding the insertion holes 30h1 and 30h2 in the case cover member 30 from the terminal members 50 and 60, and airtightly join the insertion hole surrounding portions 30s1 and 30s2 of the case cover member 30 and the terminal members 50 and 60, and fix the terminal members 50 and 60 to the case cover member 30.

[0048] The resin components 70, 80 are composed of a resin outer portion 71, 81 and a resin inner portion 72, 82. The resin outer portion 71, 81 is located on the outer side FH1 of the shell cover component 30 in the cover thickness direction FH, and the resin inner portion 72, 82 is located in the insertion holes 30h1, 30h2 of the shell cover component 30 and on the inner side FH2 of the shell cover component 30 in the cover thickness direction FH, and is connected to the resin outer portions 71, 81 as a whole.

[0049] The resin outer portion 71, 81 has: a rectangular annular top surface 71m1, 81m1, the top surface 71m1, 81m1 has a rectangular plate-shaped outer shape and faces the outer side FH1 in the cover thickness direction FH; a pair of rectangular long side surfaces 71m2, 81m2, the long side surfaces 71m2, 81m2 are along the cover long side direction DH and face opposite sides to each other in the cover short side direction EH; and a pair of rectangular short side surfaces 71m3, 81m3, the short side surfaces 71m3, 81m3 are along the cover short side direction EH and face opposite sides to each other in the cover long side direction DH. The outer surface 70m, 80m of the resin member 70, 80 exposed to the outside of the housing 10 is composed of these top surfaces 71m1, 81m1, the pair of long side surfaces 71m2, 81m2 and the pair of short side surfaces 71m3, 81m3. In the battery 1 of the present embodiment, no burnt portion is formed on any of the outer surfaces 70m, 80m (top surfaces 71m1, 81m1, long side surfaces 71m2, 81m2, short side surfaces 71m3, 81m3) of the resin members 70, 80.

[0050] Next, a method for manufacturing the battery 1 will be described (see Figures 4 to 8 First, in the "lid assembly forming step S1" (refer to Figure 4 ) to form a cover assembly 15 (see Figure 5). That is, a shell cover member 30 and terminal members 50, 60 are prepared, resin members 70, 80 are insert-molded, and terminal members 50, 60 are fixed to the shell cover member 30 via resin members 70, 80. The shell cover member 30 is obtained by punching an aluminum plate into a predetermined shape, and forming a liquid injection hole 30k, insertion holes 30h1, 30h2 and a safety valve 11 thereon. The positive terminal member 50 is obtained by punching an aluminum plate into a predetermined shape and bending it. In addition, the negative terminal member 60 is obtained by punching a copper plate into a predetermined shape and bending it.

[0051] Then, with the terminal members 50 and 60 inserted into the insertion holes 30h1 and 30h2 of the housing cover member 30, the resin members 70 and 80 are insert-molded using the above-mentioned resin material, and the terminal members 50 and 60 are fixed to the housing cover member 30 via the resin members 70 and 80 (see Figure 5 ).

[0052] Thereafter, an electrode body 40 obtained by laminating the positive electrode plate 41, the negative electrode plate 42, and the separator 43 is prepared, and the terminal extension 52 of the positive terminal member 50 is welded to the positive electrode collector 40c of the electrode body 40. In addition, the terminal extension 62 of the negative terminal member 60 is welded to the negative electrode collector 40d of the electrode body 40. Then, the electrode body 40 is wrapped with the bag-shaped insulating holder 7. Thus, the cover assembly 15 having the case cover member 30, the terminal members 50, 60, the resin members 70, 80, the electrode body 40, and the insulating holder 7 is formed.

[0053] Next, in the "shielding step S2" (refer to Figure 4 ), a shielding member SA is disposed on the cover assembly 15, and the shielding member SA prevents the scattered light LB of the laser LC from reaching the resin members 70, 80 in the laser welding step S3 described later (see Figure 6 as well as Fig. 7A , 7B ). First, the shielding member SA is described. The shielding member SA is obtained by bending a rectangular metal plate MA, and the metal plate MA has an Ag-plated layer MAd formed on the entire surface of a stainless steel plate MAc. Therefore, in the shielding member SA of the present embodiment, the shielding member SA has an Ag-plated layer MAd on the entire surface including the portion SAp where the scattered light LB of the laser LC reaches in the laser welding step S3 described later.

[0054] The shielding member SA is configured to be detachably mounted on the resin members 70 and 80 of the cover assembly 15. In addition, the shielding member SA has a shape that blocks the scattered light LB of the laser light LC from reaching the pair of long side surfaces 71m2 and 81m2 of the resin members 70 and 80, and has a shape that is longer than the long side surfaces 71m2 and 81m2 of the resin members 70 and 80 in the cover long side direction DH. Specifically, the shielding member SA is composed of a pair of side wall portions SA1, the pair of side wall portions SA1 covering the pair of long side surfaces 71m2 and 81m2 of the resin members 70 and 80, and a connecting portion SA2 connecting the side wall portions SA1 to each other, and is arranged on the outer side FH1 of the top surface 71m1 and 81m1 of the resin members 70 and 80 in the cover thickness direction FH.

[0055] The side wall portion SA1 is a rectangular plate that covers the entire surface of the long side surfaces 71m2 and 81m2 of the resin members 70 and 80, and its cover lengthwise direction DH is longer than the cover lengthwise direction DH of the long side surfaces 71m2 and 81m2 (see Figure 7B ).

[0056] The connecting portion SA2 is bent at multiple locations and has two protruding portions SA3 protruding in an inverted V shape toward the outer side FH1 in the cover thickness direction FH, a pair of first flat portions SA4 connecting the side wall portion SA1 and the protruding portions SA3, and a second flat portion SA5 connecting the two protruding portions SA3. The first flat portion SA4 and the second flat portion SA5 are rectangular plates along the top surfaces 71m1 and 81m1 of the resin members 70 and 80.

[0057] like Fig. 7A As shown by the arrows in the figure, when the two protrusions SA3 are pressed in a direction in which they approach each other, the gap KG between the side wall portions SA1 of the shielding member SA is expanded, and the gap KG is larger than the dimension of the resin members 70, 80 in the cover short side direction EH. On the other hand, when the above-mentioned pressing is released, the gap KG between the side wall portions SA1 is narrowed, and the gap KG is smaller than the dimension of the resin members 70, 80 in the cover short side direction EH.

[0058] Therefore, in the shielding step S2, the two protrusions SA3 of the shielding member SA are pressed in the direction in which they approach each other, and the shielding member SA is covered on the resin members 70 and 80 in a state where the gap KG between the side wall portions SA1 is enlarged. Then, when the above-mentioned pressing is released, the gap KG between the side wall portions SA1 is narrowed, and the resin members 70 and 80 are elastically clamped by the pair of side wall portions SA1 in the cover short side direction EH. As a result, the shielding member SA is temporarily fixed to the resin members 70 and 80 of the cover assembly 15.

[0059] Next, in the "laser welding step S3" (refer to Figure 4), prepare the case body member 20, insert the electrode body 40 covered by the insulating retainer 7 in the cover assembly 15 into the case body member 20, and plug the opening 20c of the case body member 20 with the case cover member 30 (refer to Figure 8 ). Then, the opening 20c of the case body member 20 and the peripheral edge 30f of the case cover member 30 are irradiated with laser light LC all around, and laser welding is performed airtightly to form the case 10 accommodating the electrode body 40 therein.

[0060] Specifically, the shell 10 is formed by performing the following laser welding throughout the entire circumference: using a fiber laser, irradiating the opening 20c of the shell main body member 20 and the peripheral edge 30f of the shell cover member 30 with laser light LC having a wavelength λ of 1.06μm from the outer side FH1 of the shell cover member 30 in the cover thickness direction FH, and after the opening 20c and the peripheral edge 30f are melted and mixed, they are solidified to form a molten solidified portion 25.

[0061] At this time, in the conventional method, the scattered light LB emitted from the irradiated portion P of the laser light LC directly reaches a portion of the outer surfaces 70m, 80m of the resin members 70, 80 (a pair of long side surfaces 71m2, 81m2 and a pair of short side surfaces 71m3, 81m3), so that burnt portions are easily generated on these long side surfaces 71m2, 81m2 and short side surfaces 71m3, 81m3. In particular, the long side surfaces 71m2, 81m2 are close to the irradiated portion P of the laser light LC, and the high-intensity scattered light LB reaches them, so that burnt portions are easily generated.

[0062] In contrast, in the present embodiment, a portion (top surface 71m1 and a pair of long side surfaces 71m2, 81m2) of the outer surfaces 70m, 80 of the resin members 70, 80 is covered by the shielding member SA. Therefore, the scattered light LB of the laser light LC does not reach the top surface 71m1 and a pair of long side surfaces 71m2, 81m2 of the outer surfaces 70m, 80 of the resin members 70, 80, thereby preventing the top surface 71m1 and the long side surfaces 71m2, 81m2 of the resin members 70, 80 from being burnt.

[0063] In addition, a pair of short side surfaces 71m3, 81m3 in the outer surfaces 70m, 80m of the resin members 70, 80 are not covered by the shielding member SA. However, the short side surfaces 71m3, 81m3 are sufficiently separated from the irradiated portion P of the laser LC, and even if the short side surfaces 71m3, 81m3 are not covered by the shielding member SA, the high-intensity scattered light does not reach the short side surfaces 71m3, 81m3, and therefore no burnt portion is generated on the short side surfaces 71m3, 81m3. Therefore, no burnt portion is generated on any portion of the outer surfaces 70m, 80m (top surface 71m1, a pair of long side surfaces 71m2, 81m2, and a pair of short side surfaces 71m3, 81m3) of the resin members 70, 80.

[0064] Next, in the "removal step S4" (refer to Figure 4 ), remove the shielding member SA. Specifically, the two protrusions SA3 of the shielding member SA are pressed in the direction in which they approach each other, and the shielding member SA is lifted up in a state where the gap KG between the side wall portions SA1 is enlarged. In this way, the shielding member SA can be easily removed from the resin members 70, 80 and the cover assembly 15.

[0065] Next, in the "liquid injection / sealing step S5" (refer to Figure 4 ), the electrolyte 5 is injected into the shell 10 through the injection hole 30k, and the electrolyte 5 is impregnated into the electrode body 40. Then, the injection hole 30k is covered from the outside with a sealing member 12, and the sealing member 12 is laser welded to the shell 10 in an airtight manner.

[0066] Next, in the "initial charging / aging step S6", a charging device (not shown) is connected to the battery 1 to perform initial charging on the battery 1. Then, the initially charged battery 1 is left to stand for a predetermined time to age the battery 1. In this way, the battery 1 is completed.

[0067] As described above, in the method for manufacturing battery 1 , laser welding step S3 is performed with shielding member SA disposed on cover assembly 15 , so scattered light LB of laser light LC is unlikely to reach resin members 70 , 80 , thereby preventing burnt portions from being generated on resin members 70 , 80 .

[0068] Furthermore, in this embodiment, the Ag-plated layer MAd is provided at the portion SAp where the scattered light LB of the laser LC reaches in the shielding member SA. The Ag-plated layer MAd is not easy to absorb the laser LC having a wavelength λ of 0.5 μm or more, and is not easy to melt even if the scattered light LB of the laser LC reaches it. Therefore, the shielding member SA becomes less likely to be melted by the scattered light LB of the laser LC, and the shielding member SA can be reused.

[0069] In addition, since the shielding member SA has a structure that can be detachably mounted on the resin members 70 and 80 of the cover assembly 15, the shielding member SA can be temporarily fixed to the resin members 70 and 80 (cover assembly 15) by the shielding member SA itself. As a result, when the cover assembly 15 equipped with the shielding member SA is transported, the shielding member SA can be prevented from being displaced from a predetermined position of the cover assembly 15 or being separated from the cover assembly 15, so that the cover assembly 15 equipped with the shielding member SA can be easily handled. In addition, the shielding member SA is made by bending the metal plate MA, so it can be an inexpensive shielding member.

[0070] In addition, in the present embodiment, the housing cover member 30 is in the shape of a rectangular plate extending in the cover long side direction DH, and the resin outer side portions 71 and 81 of the resin members 70 and 80 are in the shape of a rectangular plate having top surfaces 71m1 and 81m1, a pair of long side surfaces 71m2 and 81m2, and a pair of short side surfaces 71m3 and 81m3, and the distance from the irradiated portion P of the laser LC to the long side surfaces 71m2 and 81m2 of the resin members 70 and 80 is short. Therefore, the high-intensity scattered light LB easily reaches the long side surfaces 71m2 and 81m2 of the resin members 70 and 80, and easily generates a burnt portion on the long side surfaces 71m2 and 81m2. In contrast, in the present embodiment, the shielding member SA has a shape that prevents the scattered light LB from reaching the pair of long side surfaces 71m2 and 81m2 of the resin members 70 and 80, and thus can prevent the generation of a burnt portion on the long side surfaces 71m2 and 81m2 of the resin members 70 and 80.

[0071] In addition, since the shielding member SA has a shape that is longer than the long sides 71m2, 81m2 of the resin members 70, 80 in the long side direction DH of the cover, in the laser welding step S3, the scattered light LB of the laser LC can be properly prevented from reaching the long sides 71m2, 81m2 of the resin members 70, 80, and the formation of burnt portions on the long sides 71m2, 81m2 of the resin members 70, 80 can be more reliably prevented.

[0072] (Deformation method)

[0073] Next, a modification of the above-mentioned embodiment is described. In addition, the description of the same parts as those in the embodiment is omitted or simplified. The shielding member SA used in the embodiment has an Ag-plated layer MAd on the entire surface of the shielding member SA including the portion SAp where the scattered light LB of the laser LC reaches. In contrast, the shielding member SB used in this modification is different in that the shielding member SB including the portion SBp where the scattered light LB of the laser LC reaches is formed entirely of Cu.

[0074] Specifically, the shielding member SB of this modified form is obtained by bending a metal plate MB made of a copper plate. However, the shape of the shielding member SB is the same as the shape of the shielding member SA of the embodiment. That is, the shielding member SB is composed 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 a second flat plate portion SB5) like the shielding member SA. Therefore, the shielding member SB of this modified form can also be handled in the same way as the shielding member SA of the embodiment.

[0075] Even when the battery 1 is manufactured using such a shielding member SB, when laser welding is performed in the laser welding step S3, the scattered light LB of the laser LC is not easy to reach the resin members 70 and 80 due to the shielding member SB, so that the burning part can be prevented from being generated on the resin members 70 and 80. Furthermore, the portion SBp of the shielding member SB to which the scattered light LB of the laser LC reaches is made of Cu. Therefore, the shielding member SB becomes less likely to be melted by the scattered light LB of the laser LC, so the shielding member SB can be reused. The other parts that are the same as those in the embodiment have the same effects as those in the embodiment.

[0076] As mentioned above, although this invention was demonstrated based on embodiment and a modification, this invention is not limited to embodiment and a modification, It can change suitably and apply within the range which does not deviate from the summary.

[0077] For example, in the embodiments, shielding members SA and SB are exemplified as shielding members that are detachably mounted on the resin members 70 and 80 in the cover assembly 15, but the present invention is not limited thereto. For example, when the terminal member has a terminal protrusion that protrudes outward in the cover thickness direction relative to the resin member, the shielding member may be configured as a terminal protrusion of the terminal member that is detachably mounted on the cover assembly.

[0078] Description of Reference Numerals

[0079] 1Battery (electricity storage device)

[0080] 10 Shell

[0081] 15 cover assembly

[0082] 20 Shell body component

[0083] 20c opening

[0084] 30 Shell cover member

[0085] 30f peripheral part

[0086] 30h1, 30h2 through hole

[0087] 30s1, 30s2 Insertion hole surrounding area

[0088] 40 electrode body

[0089] 50, 60 terminal components

[0090] 70, 80 resin components

[0091] SA, SB shielding components

[0092] SAp, SBp (the part where the scattered light of the laser beam in the shielding member reaches)

[0093] SA1, SB1 side wall

[0094] SA2, SB2 connection

[0095] SA3, SB3 protrusion

[0096] SA4, SB4 first flat plate

[0097] SA5, SB5 second flat plate

[0098] KG (Gap between side walls)

[0099] MA, MB metal sheets

[0100] MAc stainless steel plate

[0101] MAd Ag coating

[0102] LC Laser

[0103] LB scattered light

[0104] P irradiated area

[0105] S1 Cover assembly forming process

[0106] S2 Masking Process

[0107] S3 laser welding process

[0108] S4 Removal Process

Claims

1. A method for manufacturing an electric storage device, the electric storage device comprising: A housing, the housing comprising a bottomed cylindrical housing body member and a housing cover member, the housing body member having an opening, the housing cover member having an insertion hole and being welded to the housing body member over the entire circumference in a manner to close the opening; a terminal member inserted into the insertion hole of the housing cover member; as well as a resin member that insulates a portion of the housing cover member surrounding the insertion hole from the terminal member and joins them to fix the terminal member to the housing cover member, wherein: The method for manufacturing the power storage device comprises: A laser welding step, in which, in a cover assembly in which the terminal member and the housing cover member are integrated via the resin member, the housing cover member blocks the opening of the housing body member by irradiating the opening of the housing body member and the peripheral edge of the housing cover member with laser light throughout the entire circumference to perform laser welding, thereby forming the housing; a shielding step of, before the laser welding step, disposing a shielding member on the cover assembly, the shielding member preventing scattered light of the laser from reaching the resin member; and A removing process, after the laser welding process, removing the shielding member.

2. The method for manufacturing an electric storage device according to claim 1, wherein: The wavelength of the laser is 0.5 μm or more. The shielding member has an Ag plated layer at a portion where the scattered light of the laser beam reaches.

3. The method for manufacturing an electric storage device according to claim 1, wherein: The wavelength of the laser is 0.9 μm or more. A portion of the shielding member where the scattered light of the laser beam reaches is made of Cu.

4. The method for manufacturing an electrical storage device according to any one of claims 1 to 3, wherein: The shielding member is configured to be detachably mounted on the resin member or the terminal member in the cover assembly.

5. The method for manufacturing an electric storage device according to claim 4, wherein: The shielding member is made by bending a metal plate.

Images