Method for manufacturing an electricity storage device and an electricity storage device

Abstract

To provide a method of manufacturing a power storage device, and the like, capable of suppressing generation of a burned part on a resin member for isolating between a lid member and terminal members due to scattered light of laser light at laser welding.SOLUTION: A method of manufacturing a power storage device 1 includes a lid formation step S1, a lid assembly formation step S2, a closing step S3, and a welding step S4. The lid formation step S1 includes a convex part formation step S12 of forming convex parts 35 and 36 located between a peripheral edge part 31 of a lid member 30 and insertion hole peripheral parts 33 and 34 to block irradiation of scattered light LC of laser light LB to resin members 70 and 80, by forging, the convex parts 35 and 36 having a distance D from an end surface 31s of the peripheral edge part 31 to lateral faces 35ks and 36ks of the convex parts 35 and 36 with respect to a thickness t of the lid member 30 being set to be equal to or less than 0.5t.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a method for manufacturing an electricity storage device such as a battery or a capacitor in which a terminal member is fixed to a case via a resin member, and to the electricity storage device. [Background technology]

[0002] As an electricity storage device, a rectangular battery is known in which positive and negative terminal members are fixed to a rectangular box-shaped case via a resin member. Specifically, the case is composed of a bottomed rectangular cylindrical body member having a rectangular annular opening, and a rectangular plate-shaped cover member laser-welded to the body member over the entire circumference in a form that closes the opening. The positive and negative terminal members are inserted into a pair of insertion holes drilled in the cover member, respectively, and extend from the inside of the case to the outside of the case. A pair of resin members are joined to the cover member and the terminal members, respectively, while insulating the cover member from the positive and negative terminal members, respectively. For example, Patent Documents 1 and 2 can be cited as related prior art (see Figures 1 and 2, etc. of Patent Document 1 and Figures 1 and 2, etc. of Patent Document 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-086813 [Patent Document 2] JP 2013-054964 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, during the manufacturing process of such batteries, when the opening of the main body member is sealed with a cover member to which a terminal member has already been fixed, and the opening of the main body member and the peripheral edge of the cover member are laser welded all around, scattered laser light may be irradiated to the resin member that provides insulation between the cover member and the terminal member, causing scorched areas in the resin member.

[0005] The present invention has been made in consideration of the current situation, and provides a manufacturing method for an electricity storage device that can prevent the occurrence of scorched areas in the resin member that insulates between the cover member and the terminal member due to scattered laser light when the main body member and the cover member are laser welded to form a case, and provides an electricity storage device. [Means for solving the problem]

[0006] (1) One aspect of the present invention for solving the above problem is a method for manufacturing an electricity storage device including a case having a bottomed cylindrical main body member having an opening, and a lid member laser-welded to the main body member around an entire circumference in a manner to close the opening, a terminal member inserted into an insertion hole penetrating the lid member in a lid thickness direction, and a resin member joined to an insertion hole peripheral portion of the lid member and the terminal member while insulating between an insertion hole peripheral portion surrounding the insertion hole of the lid member and the terminal member, the method including: a lid forming process for forming the lid member a lid assembly forming step of insert-molding the resin member with the terminal member inserted into the insertion hole of the lid member to form a lid assembly in which the terminal member is integrated with the lid member via the resin member; a closing step of closing the opening of the main body member with the lid member of the lid assembly; and a welding step of irradiating a laser beam from the outside of the lid member in the lid thickness direction to laser-weld the opening of the main body member and a peripheral portion of the lid member over the entire circumference to form the case, wherein the lid forming step is The end face of the peripheral portion of the cover member where the protrusion is not yet formed is struck to plastically deform the peripheral portion and its neighboring portion. By forging, the projection is positioned between the peripheral portion of the lid member and the peripheral portion of the insertion hole, protruding outward in the thickness direction of the lid, and blocking scattered light of the laser light irradiated to the opening and the peripheral portion from being irradiated to the resin member. the above A protrusion, in which a distance D from an end face of the peripheral portion to a side face of the base end of the protrusion on the peripheral portion side is set to within 0.5t (D≦0.5t) with respect to a thickness t of the lid member. the above The method for manufacturing an electricity storage device includes a convex portion forming step of forming a convex portion.

[0007] In the manufacturing method of the above-mentioned electricity storage device, a lid member having the above-mentioned convex portion between the peripheral portion and the surrounding portion of the insertion hole is used. As a result, in the welding process, the scattered light of the laser light is blocked by the convex portion and is less likely to be irradiated onto the resin member, so that the occurrence of scorched portions in the resin member can be suppressed. In addition, since the convex portion is formed near the end face of the peripheral portion of the lid member by forging (specifically, at a position where the distance D from the end face of the peripheral portion to the side surface of the base end of the convex portion is within 0.5t with respect to the thickness t of the lid member), the convex portion can be formed with high precision.

[0008] In addition, the "convex portion" of the cover member may be provided, for example, between the peripheral portion and the surrounding portion of the insertion hole along the entire circumference of the peripheral portion, or may be provided only on a portion of the peripheral portion along the peripheral portion. Examples of "electricity storage devices" include secondary batteries such as lithium ion secondary batteries, capacitors such as lithium ion capacitors, and all-solid-state batteries.

[0009] (2) Further, in the method for manufacturing an electricity storage device described in (1), the opening of the main body member is a rectangular ring having a pair of long side openings and a pair of short side openings, the peripheral portion of the lid member is a rectangular ring having a pair of long side peripheral portions and a pair of short side peripheral portions, the closing step may include closing the opening of the main body member with the lid member by facing the pair of long side peripheral portions of the lid member to the pair of long side openings of the main body member and the pair of short side peripheral portions of the lid member to the pair of short side openings of the main body member, and the protrusions of the lid member may be located between the pair of long side peripheral portions and the insertion hole peripheral portions of the lid member and include a pair of protruding ridges extending along the long side peripheral portions.

[0010] In this manufacturing method, the rectangular annular opening of the main body member and the rectangular annular peripheral portion of the cover member are laser welded together. In this case, the resin member provided on the cover member is likely to be in close proximity to a portion of the long side peripheral portion of the peripheral portion of the cover member, and a burnt portion is likely to occur in the peripheral vicinity portion of the resin member that is close to the long side peripheral portion. This is because the distance that the scattered light of the laser beam travels to the resin member (periphery vicinity portion) is short. In contrast, in the above-described method for manufacturing an electricity storage device, the protrusion provided on the cover member includes a protruding ridge portion located between the long side peripheral portion and the insertion hole peripheral portion and extending along the long side peripheral portion, which makes it possible to suppress the occurrence of scorching in the resin member, particularly in the peripheral portion close to the long side peripheral portion, where scorching is likely to occur.

[0011] (3) Still another aspect is an electric storage device including: a case having a bottomed cylindrical main body member having an opening; and a lid member laser-welded to the main body member over an entire circumference in a form that closes the opening; a terminal member inserted into an insertion hole penetrating the lid member in a lid thickness direction; and a resin member joined to the insertion hole peripheral portion of the lid member and the terminal member while insulating between the insertion hole peripheral portion surrounding the insertion hole of the lid member and the terminal member, wherein the lid member is a convex portion located between a peripheral portion of the lid member and the insertion hole peripheral portion, protruding toward the outside in the lid thickness direction, and blocking scattered light of laser light irradiated to the opening and the peripheral portion from being irradiated to the resin member, and a distance D from an end face of the peripheral portion to a side surface of a base end of the convex portion on the peripheral portion side is within 0.5t (D≦0.5t) with respect to a thickness t of the lid member. The end face of the peripheral portion of the cover member where the protrusion is not yet formed is struck to plastically deform the peripheral portion and its neighboring area. Formed by forging the above The resin member has a protrusion, and the generation of a burnt portion is suppressed by the protrusion of the lid member in the electricity storage device.

[0012] In the above-mentioned electricity storage device, the occurrence of burnt parts in the resin member is suppressed, so that the original appearance of the resin member can be maintained, and the decrease in insulation resistance between the cover member and the terminal member due to the burnt parts can be suppressed. Also, the convex part is formed by forging near the end face of the peripheral part of the cover member (specifically, at a position where the distance D from the end face of the peripheral part to the side face of the base end of the convex part is within 0.5t, where t is the thickness of the cover member), so that the convex part is formed with good accuracy.

[0013] (4) Further, in the energy storage device described in (3), the opening of the main body member is a rectangular ring having a pair of long side openings and a pair of short side openings, the peripheral portion of the cover member is a rectangular ring having a pair of long side peripheral portions and a pair of short side peripheral portions, the convex portions are located between the pair of long side peripheral portions and the insertion hole surrounding portion of the cover member, respectively, and include a pair of convex ridge portions extending along the long side peripheral portions, and the resin member is an energy storage device in which the generation of burnt portions is suppressed in peripheral vicinity portions of the resin member that are close to the long side peripheral portions by the convex ridge portions of the cover member.

[0014] In the above-mentioned energy storage device, the occurrence of scorched portions is suppressed in the peripheral area of ​​the resin member close to the long side peripheral edge of the cover member, which is particularly prone to scorching. Therefore, the original appearance of the resin member can be maintained even in this peripheral area, and a decrease in insulation resistance can be suppressed. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a perspective view of a battery according to an embodiment. [Diagram 2] 1 is a cross-sectional view of a battery according to an embodiment taken along a battery height direction and a battery width direction. [Diagram 3] 1A and 1B are partially enlarged cross-sectional views of the opening of the main body member and the peripheral portion of the cover member of the battery of the embodiment, where (a) is a partially enlarged cross-sectional view along the battery height direction and the battery width direction, and (b) is a partially enlarged cross-sectional view along the battery height direction and the battery thickness direction. [Figure 4] 2 is a flowchart of a method for manufacturing a battery according to an embodiment. [Diagram 5] Regarding the manufacturing method of a battery according to an embodiment, in the convex portion forming step of the lid forming process, (a) is an explanatory diagram showing the state before the convex rib portion is formed on the lid member, and (b) is an explanatory diagram showing the state after the convex rib portion has been formed on the lid member. [Figure 6] 4A to 4C are explanatory views showing a lid assembly formed in a lid assembly forming step in the manufacturing method of the battery according to the embodiment. [Figure 7]11 is an explanatory diagram showing the state in which the opening of the body member is closed with the lid member constituting the lid assembly in the closing step in the manufacturing method of the battery according to the embodiment. FIG. [Figure 8] 1A is an explanatory diagram showing how the opening of the main body member and the peripheral portion of the cover member are laser welded together in a welding process in a manufacturing method for a battery according to an embodiment; FIG. 1B is an explanatory diagram of a partially enlarged cross-section along the battery height direction and the battery width direction; and FIG. 1B is an explanatory diagram of a partially enlarged cross-section along the battery height direction and the battery thickness direction. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 shows a perspective view of a battery (electricity storage device) 1 according to this embodiment, Fig. 2 shows a cross-sectional view of the entire battery 1, and Fig. 3 shows an enlarged cross-sectional view of a portion of the battery 1 near an opening 21 of a body member 20 and a peripheral portion 31 of a lid member 30. In the following description, the battery height direction AH, battery width direction BH, and battery thickness direction CH of the battery 1 are defined as the directions shown in Figs. 1 to 3. The battery 1 is a rectangular (rectangular) sealed lithium ion secondary battery that is mounted on vehicles such as hybrid cars, plug-in hybrid cars, and electric cars.

[0017] The battery 1 is composed of a case 10, an electrode body 40 contained in the case 10, and positive and negative terminal members 50, 60 supported on a case upper portion 11 of the case 10 via resin members 70, 80. Inside the case 10, the electrode body 40 is covered by a bag-shaped insulating holder 5 made of an insulating film and opening to an upper side AH1 in the battery height direction AH. An electrolyte 3 is also contained inside the case 10, a part of which is impregnated into the electrode body 40 and the remainder is pooled on the case bottom portion 12 of the case 10.

[0018] Of these, the case 10 is a rectangular box made of metal (aluminum in this embodiment) and has a rectangular case upper part 11 located on the upper side AH1 of the battery height direction AH, an opposing rectangular case bottom part 12 located on the lower side AH2 of the battery height direction AH, and four rectangular case sides (a pair of case long sides 13, 14 and a pair of case short sides 15, 16) connecting the two.

[0019] The case 10 is composed of a main body member 20 and a lid member 30. The main body member 20 is a bottomed rectangular cylinder having a rectangular annular opening 21 with a pair of long side openings 21b and a pair of short side openings 21c on the upper side AH1 in the battery height direction AH, and constitutes the case bottom 12, the case long side parts 13, 14, and the case short side parts 15, 16 of the case 10. On the other hand, the lid member 30 is a rectangular plate and constitutes the case upper part 11 of the case 10. The lid member 30 is laser welded to the main body member 20 over its entire circumference in a manner to close the opening 21 of the main body member 20, and a welded part 18 is formed between the lid member 30 and the main body member 20. Specifically, the welded part 18 is formed by welding a pair of long side openings 21b of the rectangular annular opening 21 of the main body member 20 to a pair of long side peripheral parts 31b of the rectangular annular peripheral part 31 of the lid member 30 (see FIG. 3(b)). Furthermore, a pair of short side openings 21c of the opening 21 of the main body member 20 and a pair of short side peripheral edges 31c of the peripheral edge 31 of the cover member 30 are welded to each other to form welds 18 (see FIG. 3(a)).

[0020] The cover member 30 is provided with a safety valve 19 that breaks and opens when the internal pressure of the case 10 exceeds the valve opening pressure. The cover member 30 is also formed with a liquid injection hole 30k that communicates between the inside and outside of the case 10, and is airtightly sealed with a disk-shaped sealing member 39 made of aluminum. The lid member 30 has rectangular insertion holes 33h, 34h near an end of one side BH1 in the battery width direction BH and near an end of the other side BH2, respectively, penetrating in the lid thickness direction DH. A positive electrode terminal member 50 made of aluminum is inserted into one of the insertion holes 33h, and is fixed to the lid member 30 in a state insulated from the lid member 30 via a resin member 70. A negative electrode terminal member 60 made of copper is inserted into the other insertion hole 34h, and is fixed to the lid member 30 in a state insulated from the lid member 30 via a resin member 80.

[0021] These terminal members 50, 60 each have a rectangular plate-shaped external terminal portion 51, 61 arranged on the cover member 30, and an internal terminal portion 52, 62 arranged mainly inside the case 10 and connected to the external terminal portion 51, 61 via the insertion holes 33h, 34h of the cover member 30. The positive electrode internal terminal portion 52 is joined to and conductively connected with the positive electrode tab 40a of the electrode body 40 inside the case 10. On the other hand, the negative electrode internal terminal portion 62 is joined to and conductively connected with the negative electrode tab 40b of the electrode body 40 inside the case 10.

[0022] The positive electrode resin member 70 surrounds the insertion hole 33h of the lid member 30, and is joined to the insertion hole surrounding portion 33 of the lid member 30 and the terminal member 50 while providing insulation between the terminal member 60 and the rectangular annular insertion hole surrounding portion 33 having a pair of long side peripheral portions 33e and a pair of short side peripheral portions 33f. Similarly, the negative electrode resin member 80 surrounds the insertion hole 34h of the lid member 30, and is joined to the insertion hole surrounding portion 34 of the lid member 30 and the terminal member 60 while providing insulation between the terminal member 60 and the rectangular annular insertion hole surrounding portion 34 having a pair of long side peripheral portions 34e and a pair of short side peripheral portions 34f.

[0023] These resin members 70, 80 are made of polyphenylene sulfide (PPS) and have rectangular plate-shaped external insulating parts 71, 81 arranged on the cover member 30, and internal insulating parts 72, 82 arranged inside the case 10 and in the insertion holes 33h, 34h of the cover member 30 and connected to the external insulating parts 71, 81. Of these, the external insulating parts 71, 81 insulate between the external terminal parts 51, 61 of the terminal members 50, 60 and the insertion hole surrounding parts 33, 34 of the cover member 30. On the other hand, the internal insulating parts 72, 82 insulate between the internal terminal parts 52, 62 of the terminal members 50, 60 and the insertion hole surrounding parts 33, 34 of the cover member 30.

[0024] In addition, in the lid member 30, between a pair of long side peripheral portions 33e of the positive electrode insertion hole surrounding portion 33 and a pair of opposing long side peripheral portions 31be of a pair of long side peripheral portions 31b of the peripheral portion 31 that are close to the long side peripheral portions 33e, a pair of convex strip portions (convex portions) 35 are provided which protrude toward the outside DH1 in the lid thickness direction DH (the upper side AH1 in the battery height direction AH) and extend linearly in the battery width direction BH along the long side peripheral portions 31b (opposing long side peripheral portions 31be) (see Figures 1 and 3(b)). In addition, in the lid member 30, between a pair of long side peripheral portions 34e of the negative electrode insertion hole surrounding portion 34 and a pair of opposing long side peripheral portions 31be of a pair of long side peripheral portions 31b of the peripheral portion 31 that are close to the long side peripheral portions 34e, a pair of convex strip portions (convex portions) 36 are provided which protrude toward the outside DH1 in the lid thickness direction DH (the upper side AH1 in the battery height direction AH) and extend linearly in the battery width direction BH along the long side peripheral portions 31b.

[0025] These ridges 35, 36 are formed by forging in the vicinity of the end face 31s of the peripheral edge 31 of the cover member 30 as described later. Specifically, the ridges 35, 36 are formed at positions where the distance D from the end face 31s of the peripheral edge 31 to the side faces 35ks, 36ks of the base ends 35k, 36k of the ridges 35, 36 on the peripheral edge 31 side (left side in FIG. 3(b)) is within 0.5t (D≦0.5t, in this embodiment, D=0.5t) with respect to the thickness t of the cover member 30. As described below, when forming the case 10 by laser welding, these convex ridges 35, 36 block scattered light LC of laser light LB irradiated to the opening 21 of the body member 20 and the peripheral edge 31 of the cover member 30 from being irradiated to the resin members 70, 80. In the battery 1 of this embodiment, these convex ridges 35, 36 prevent the occurrence of scorched parts BP (see FIG. 8(b)) in the resin members 70, 80.

[0026] The electrode body 40 is a flat rectangular parallelepiped, and is a laminated electrode body in which a plurality of positive electrode plates 41 and a plurality of negative electrode plates 42, each of which has a rectangular shape extending in the battery height direction AH and the battery width direction BH, are alternately laminated in the battery thickness direction CH via a separator 43 made of a porous resin film. Each positive electrode plate 41 has a positive electrode current collector 41r extending to the upper side AH1, and the positive electrode current collectors 41r overlap each other in the thickness direction to form the above-mentioned positive electrode tab 40a. This positive electrode tab 40a is connected to the internal terminal portion 52 of the positive electrode terminal member 50 as described above. Each negative electrode plate 42 has a negative electrode current collector 42r extending to the upper side AH1, and the negative electrode current collectors 42r overlap each other in the thickness direction to form the above-mentioned negative electrode tab 40b. This negative electrode tab 40b is connected to the internal terminal portion 62 of the negative electrode terminal member 60 as described above.

[0027] In the battery 1 of this embodiment, the convex stripes 35, 36 prevent the generation of scorched parts BP in the resin members 70, 80, so that the original appearance of the resin members 70, 80 can be maintained and a decrease in insulation resistance between the cover member 30 and the terminal members 50, 60 via the scorched parts BP can be suppressed. Particularly in this embodiment, the generation of scorched parts BP is suppressed even in the peripheral vicinity parts 70e, 80e of the resin members 70, 80 that are close to the opposing long side peripheral part 31be of the long side peripheral part 31b where scorched parts BP are likely to occur, so that the original appearance of the resin members 70, 80 can be maintained even in the peripheral vicinity parts 70e, 80e and a decrease in insulation resistance can be suppressed. In addition, the convex rib portions 35, 36 are formed by forging near the end face 31s of the peripheral portion 31 of the cover member 30 (at a position where the distance D from the end face 31s of the peripheral portion 31 to the side faces 35ks, 36ks of the base ends 35k, 36k of the convex rib portions 35, 36 is within 0.5t, where t is the thickness of the cover member 30), resulting in the production of the convex rib portions 35, 36 with high precision.

[0028] Next, a method for manufacturing the battery 1 will be described (see Figs. 4 to 8). First, in a "lid forming step S1" (see Fig. 4), a lid member 30 is formed. That is, first, in a "punching step S11" of the lid forming step S1, an aluminum plate is prepared and punched into a rectangular shape by a press, and a safety valve 19, a liquid injection hole 30k, and insertion holes 33h, 34h are provided, thereby forming a lid member 30Z (see Fig. 5(a)) that does not have protruding portions 35, 36.

[0029] Thereafter, in the "projection forming step S12" of the lid forming step S1, the lid member 30Z is forged to form the ridges 35, 36 (see Figs. 5(a) and 5(b)). Specifically, as shown in Fig. 5(a), the lid member 30Z is sandwiched between a first die KA and a second die KB in the lid thickness direction DH. The first die KA is provided with a step portion KAD for forming the ridges 35, 36.

[0030] Next, the third mold KC is moved to the right in FIG. 5(b) toward the lid member 30Z and the first mold KA, and the end face 31s of the peripheral portion 31 of the lid member 30Z is struck to plastically deform the peripheral portion 31 of the lid member 30Z and its neighboring portion. Then, the convex ridges 35, 36 are formed in the space between the third mold KC and the step portion KAD of the first mold KA. As described above, the convex ridges 35, 36 are formed at a position where the distance D from the end face 31s of the peripheral portion 31 to the side faces 35ks, 36ks of the base ends 35k, 36k of the convex ridges 35, 36 is within 0.5t (D≦0.5t, in this embodiment, D=0.5t) with respect to the thickness t of the lid member 30. In this way, the lid member 30 having the convex ridges 35, 36 with high accuracy is formed.

[0031] Next, in the "lid assembly formation process S2" (see FIG. 4), the lid assembly 7 is formed (see FIG. 6). That is, the terminal members 50, 60 are further prepared, and the resin members 70, 80 are insert-molded to integrate the terminal members 50, 60 with the lid member 30 via the resin members 70, 80. Specifically, the positive terminal member 50 is obtained by pressing an aluminum plate, and the negative terminal member 60 is obtained by pressing a copper plate, respectively. Then, with the terminal members 50, 60 inserted into the insertion holes 33h, 34h of the lid member 30, the resin members 70, 80 are insert-molded to integrate the terminal members 50, 60 with the lid member 30 via the resin members 70, 80.

[0032] Next, an electrode body 40 formed by stacking a positive electrode plate 41, a negative electrode plate 42, and a separator 43 is prepared, and the internal terminal portions 52, 62 of the terminal members 50, 60 integrated with the above-mentioned lid member 30 are connected to the positive electrode tab 40a and the negative electrode tab 40b of the electrode body 40 by welding, respectively. Thereafter, the electrode body 40 is wrapped in a bag-shaped insulating holder 5. In this manner, a lid assembly 7 consisting of the lid member 30, the terminal members 50, 60, the resin members 70, 80, the electrode body 40, and the insulating holder 5 is formed.

[0033] Next, in the "closing step S3" (see FIG. 4), the main body member 20 is prepared, the electrode body 40 covered with the insulating holder 5 of the lid assembly 7 is inserted into the main body member 20, and the opening 21 of the main body member 20 is closed with the lid member 30 (see FIGS. 7 and 8(a)). Specifically, a pair of long side peripheral portions 31b of the peripheral portion 31 of the lid member 30 are opposed to a pair of long side openings 21b of the opening 21 of the main body member 20, respectively, and a pair of short side peripheral portions 31c of the peripheral portion 31 of the lid member 30 are opposed to a pair of short side openings 21c of the opening 21 of the main body member 20, respectively, to close the opening 21 of the main body member 20 with the lid member 30.

[0034] Next, in the "welding process S4" (see Figure 4), laser light LB is irradiated to the opening 21 of the main body member 20 and the peripheral portion 31 of the cover member 30 from the outside DH1 in the lid thickness direction DH of the cover member 30 (the upper side AH1 in the battery height direction AH), and the opening 21 and the peripheral portion 31 are laser welded around the entire circumference to form the case 10 (see Figure 8). In this case, the lid member 30 has convex rib portions 35, 36 between the peripheral portion 31 and the insertion hole surrounding portions 33, 34, which protrude toward the outside DH1 in the lid thickness direction DH (the upper side AH1 in the battery height direction AH). These convex rib portions 35, 36 can block the scattered light LC of the laser light LB irradiated to the opening 21 and peripheral portion 31 from being irradiated to the resin members 70, 80.

[0035] 8(b), the distance between the insertion hole surrounding parts 33, 34 of the cover member 30 and the peripheral part 31 of the cover member 30 and the opening 21 of the main body member 20 is shortest between the long side peripheral parts 33e, 34e of the insertion hole surrounding parts 33, 34 and the opposing long side peripheral parts 31be and opposing long side openings 21be that face the long side peripheral parts 33e, 34e among the long side peripheral part 31b of the peripheral part 31 and the long side opening 21b of the opening 21. Therefore, if the convex stripes 35, 36 are not provided, the scattered light LC of the laser light LB is irradiated to the peripheral vicinity parts 70e, 80e of the resin members 70, 80 that face and are close to the opposing long side peripheral part 31be of the peripheral part 31 and the opposing long side opening 21be of the opening 21, as shown by the dashed arrow in FIG.

[0036] In contrast, in this embodiment, convex stripes 35, 36 are provided between the long side peripheral parts 33e, 34e of the insertion hole peripheral parts 33, 34 and the opposing long side peripheral part 31be of the long side peripheral part 31b of the peripheral part 31, respectively, of the cover member 30. This makes it possible to prevent the scattered light LC of the laser light LB irradiated to the opposing long side peripheral part 31be of the long side peripheral part 31b of the peripheral part 31 and the opposing long side opening part 21be of the long side opening part 21b of the opening part 21 from being irradiated to the peripheral vicinity parts 70e, 80e of the resin members 70, 80, and therefore makes it possible to prevent the generation of scorched parts BP in the peripheral vicinity parts 70e, 80e of the resin members 70, 80.

[0037] The distance between the insertion hole surrounding parts 33, 34 of the cover member 30 and the peripheral part 31 of the cover member 30 and the opening part 21 of the main body member 20 is sufficiently long except for the distance between the long side peripheral parts 33e, 34e of the insertion hole surrounding parts 33, 34 and the opposing long side peripheral part 31be of the peripheral part 31 and the opposing long side opening part 21be of the opening part 21 (see also FIG. 8(a)). Therefore, even if the scattered light LC of the laser light LB is not blocked by providing a protruding ridge part, the burnt part BP is unlikely to occur in the resin members 70, 80. Therefore, in this embodiment, as described above, the protruding ridge parts 35, 36 are provided only between the long side peripheral parts 33e, 34e of the insertion hole surrounding parts 33, 34 and the opposing long side peripheral part 31be of the long side peripheral part 31b of the peripheral part 31 of the cover member 30.

[0038] Next, in a "pouring and sealing process S5", the electrolyte 3 is poured into the case 10 through the pouring hole 30k, and the electrolyte 3 is impregnated into the electrode body 40. Thereafter, the pouring hole 30k is covered from the outside with a sealing member 39, and the sealing member 39 is welded to the lid member 30 around its entire periphery to hermetically seal the gap between the sealing member 39 and the lid member 30. Next, in the "initial charging and aging step S6", a charging device (not shown) is connected to the battery 1 to perform an initial charge on the battery 1. After that, 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.

[0039] In the manufacturing method of the battery 1 of this embodiment, the lid member 30 is provided with the convex streaks 35, 36 between the peripheral portion 31 and the insertion hole surrounding portions 33, 34. As a result, in the welding step S4, the scattered light LC of the laser light LB is blocked by the convex streaks 35, 36, making it difficult for the resin members 70, 80 to be irradiated, so that the generation of the burnt portion BP on the resin members 70, 80 can be suppressed. In addition, the convex streaks 35, 36 are formed near the end face 31s of the peripheral portion 31 of the lid member 30 by forging (specifically, at a position where the distance D from the end face 31s of the peripheral portion 31 to the side faces 35ks, 36ks of the base ends 35k, 36k of the convex streaks 35, 36 is within 0.5t with respect to the thickness t of the lid member 30), so that the convex streaks 35, 36 can be formed with high precision.

[0040] Furthermore, in this embodiment, the cover member 30 is provided with the protruding stripes 35, 36 that are located between the long side peripheral portion 31b and the insertion hole peripheral portions 33, 34 and extend along the long side peripheral portion 31b. This makes it possible to prevent the occurrence of the scorched portion BP in the resin members 70, 80 at the peripheral vicinity portions 70e, 80e that are close to the long side peripheral portion 31b and that are particularly susceptible to the scorched portion BP.

[0041] Although the present invention has been described above with reference to an embodiment, it goes without saying that the present invention is not limited to the embodiment and can be modified as appropriate without departing from the spirit of the present invention. For example, in the embodiment, a pair of convex ridges 35, 36 extending along the long side peripheral portion 31b of the lid member 30 is provided as the convex portion, but in addition to this, as shown by the broken line in Fig. 7(a), a pair of convex ridges (convex portions) 37, 38 extending along the short side peripheral portion 31c of the lid member 30 may be provided to suppress the occurrence of burnt portions BP in the peripheral adjacent portions 70f, 80f along the short side peripheral portion 31c of the resin members 70, 80. These convex ridges 37, 38 may also be formed by forging in the vicinity of the end face 31s of the peripheral portion 31 of the lid member 30 (specifically, at a position where the distance D from the end face 31s of the peripheral portion 31 to the side faces 37ks, 38ks of the base ends 37k, 38k of the convex ridges 37, 38 is within 0.5t with respect to the thickness t of the lid member 30).

[0042] In the embodiment, the laminated electrode body 40 is exemplified as the electrode body housed in the case 10, but the electrode body may be a flat wound electrode body. Also, a plurality of electrode bodies may be housed in the case. [Explanation of symbols]

[0043] 1. Battery (energy storage device) 7 Lid Assembly 10 Cases 20 Main body parts 21 Opening 21b Long side opening 21c Short side opening 30 Lid member 30Z (without convex strip) cover member 31 Periphery 31b Long side edge 31c Short side edge 31s end face 33, 34 Surroundings of insertion hole 33h, 34h Insertion holes 33e, 34e Long side periphery 33f, 34f Short side periphery 35, 36, 37, 38 Convex portion (convex portion) 35k, 36k, 37k, 38k (base end of convex portion) 35ks, 36ks, 37ks, 38ks (side of the base end) 40 Electrode body 50,60 Terminal material 70,80 Resin material 70e, 80e (Area of ​​the resin member adjacent to the long side peripheral portion of the cover member) 70f, 80f (Area of ​​the resin member adjacent to the short side peripheral portion of the cover member) DH Lid thickness direction DH1 (lid thickness direction) outside LB laser light LC scattered light BP burnt area S1 Lid forming process S11 Punching process S12 Convex part formation process S2 Lid assembly forming process S3 occlusion process S4 Welding process S5 Liquid injection / sealing process S6 First charge and aging process

Claims

1. a case including a bottomed tubular main body member having an opening, and a cover member that is laser welded to the main body member over an entire periphery thereof in a manner that closes the opening; a terminal member inserted into an insertion hole passing through the cover member in a thickness direction of the cover; a resin member bonded to the insertion hole surrounding portion of the cover member and the terminal member while insulating the insertion hole surrounding portion of the cover member and the terminal member. A method for manufacturing an electricity storage device, comprising: a lid forming step of forming the lid member; a lid assembly forming step of inserting the resin member into the insertion hole of the lid member to form a lid assembly in which the terminal member is integrated with the lid member via the resin member; a closing step of closing the opening of the body member with the lid member of the lid assembly; a welding process of irradiating a laser beam from the outside of the lid member in the lid thickness direction to laser-weld the opening of the main body member and the peripheral portion of the lid member over an entire periphery to form the case, The lid forming step includes: The end face of the peripheral portion of the cover member where the protrusion is not yet formed is struck to plastically deform the peripheral portion and a portion adjacent thereto by forging, the protrusion is located between the peripheral portion of the lid member and the peripheral portion of the insertion hole, protrudes outward in the thickness direction of the lid, and blocks scattered light of the laser light irradiated to the opening and the peripheral portion from being irradiated to the resin member, The method includes a convex portion forming step of forming the convex portion such that a distance D from an end face of the peripheral portion to a side face of a base end portion of the convex portion on the peripheral portion side is within 0.5t (D≦0.5t) with respect to a thickness t of the lid member. A method for manufacturing an electricity storage device.

2. A method for producing the electricity storage device according to claim 1, comprising the steps of: The opening in the body member is A rectangular ring having a pair of long side openings and a pair of short side openings, The peripheral portion of the cover member is A rectangular ring shape having a pair of long side peripheral edges and a pair of short side peripheral edges, The blocking step includes: the pair of long side peripheral portions of the cover member are opposed to the pair of long side openings of the main body member, and the pair of short side peripheral portions of the cover member are opposed to the pair of short side openings of the main body member, respectively, to close the openings of the main body member with the cover member; The protrusion is The cover member includes a pair of protruding portions located between the pair of long side peripheral portions and the insertion hole peripheral portion and extending along the long side peripheral portions. A method for manufacturing an electricity storage device.

3. a case including a bottomed tubular main body member having an opening, and a cover member that is laser welded to the main body member over an entire periphery thereof in a manner that closes the opening; a terminal member inserted into an insertion hole passing through the cover member in a thickness direction of the cover; a resin member bonded to the insertion hole surrounding portion of the cover member and the terminal member while insulating the insertion hole surrounding portion of the cover member and the terminal member. An electricity storage device, The cover member is a protrusion located between the peripheral portion of the lid member and the peripheral portion of the insertion hole, protruding outward in the thickness direction of the lid, and blocking scattered light of laser light irradiated to the opening and the peripheral portion from being irradiated to the resin member, wherein a distance D from an end face of the peripheral portion to a side face of a base end of the protrusion on the peripheral portion side is within 0.5t (D≦0.5t) relative to a thickness t of the lid member, and the protrusion is formed by forging in which an end face of the peripheral portion of an unformed lid member is struck to plastically deform the peripheral portion and a portion in the vicinity thereof; The resin member is The protruding portion of the lid member suppresses the occurrence of burnt portions. Energy storage device.

4. The electricity storage device according to claim 3, The opening in the body member is A rectangular ring having a pair of long side openings and a pair of short side openings, The peripheral portion of the cover member is A rectangular ring shape having a pair of long side peripheral edges and a pair of short side peripheral edges, The protrusion is the cover member includes a pair of protruding portions located between the pair of long side peripheral portions and the insertion hole peripheral portion and extending along the long side peripheral portions, The resin member is The convex stripe of the cover member prevents the resin member from being burned at a peripheral portion adjacent to the long side peripheral portion. Energy storage device.

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