Power storage device and method for manufacturing the same

Abstract

To provide a power storage device and the like that can maintain good sealing between a resin member that fixes a terminal member to a case member and the case member and the terminal member.SOLUTION: A power storage device 1 includes a case member 21 having an insertion hole 21h, a terminal member 40, and a resin member 60 that fixes the terminal member 40 to the case member 21. The terminal member 40 includes a terminal top plate portion 43 and a terminal extension portion 53. The terminal member 40 and the resin member 60 are airtightly sealed only at a top plate roughened portion 47 that is formed in a band-like ring shape on the top plate back surface 45 of the terminal top plate portion 43 and has a roughened surface. The case member 21 and the resin member 60 are airtightly sealed only at a case roughened portion 27 that is formed in a band-like ring shape on the case inner side surface 24 of the case member 21 and has a roughened surface.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an electricity storage device in which terminal members are fixed to case members constituting a case via a resin member, and to a method for manufacturing the electricity storage device. [Background technology]

[0002] A known power storage device is a battery in which positive and negative terminal members are fixed via a resin member to a rectangular plate-shaped case lid member (case member) that forms a rectangular box-shaped case. Specifically, the positive and negative terminal members are inserted into insertion holes provided in the case lid member. The resin member contacts the case lid member and the terminal members, fixing the terminal members to the case member. Furthermore, in such a battery, the entire contact surface of the case lid member that comes into contact with the resin member and the entire contact surface of the terminal member that comes into contact with the resin member may be roughened, and the entire contact surface may hermetically seal the resin member with the case lid member and the terminal member. Related prior art includes, for example, Patent Document 1 (see Claims 1 and 5 and Figures 1, 5, 8, etc. of Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-216396 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when the above-mentioned battery is subjected to a thermal cycling test, cracks may occur between the resin member and the case lid member or the terminal member, causing the seal to break, and it has been found that it is difficult to maintain good sealing between the resin member and the case lid member and the terminal member for a long period of time.

[0005] The present invention has been made in consideration of the current situation, and provides a resin member that fixes a terminal member to a case member, an electricity storage device that can maintain good sealing between the case member and the terminal member, and a method for manufacturing the electricity storage device. [Means for solving the problem]

[0006] (1) One aspect of the present invention for solving the above problem is an electricity storage device comprising a case member having an insertion hole, a terminal member inserted into the insertion hole of the case member, and a resin member that contacts the case member and secures the terminal member to the case member while insulating them from each other, wherein the terminal member has a plate-shaped terminal top plate portion located on the outside of the case member and a terminal extension portion that extends from the terminal top plate portion toward the inside of the case member and penetrates the resin member through the insertion hole, and the terminal member and the resin member are hermetically sealed only at a top plate roughened portion that is formed in a ring shape around the entire periphery of the terminal top plate portion on the back surface of the top plate facing the case member, and the case member and the resin member are hermetically sealed only at a case roughened portion that is formed in a ring shape around the entire periphery of the insertion hole on the case inner surface of the case member facing inward.

[0007] In the above-described power storage device, the case member and the resin member are not hermetically sealed over the entire area where they contact, but are only hermetically sealed at the roughened case portion. Furthermore, the terminal member and the resin member are not hermetically sealed over the entire area where they contact, but are only hermetically sealed at the roughened top plate portion. This has been found to maintain better sealing performance between the case member and the resin member, and between the terminal member and the resin member, compared to when the case member and the resin member are hermetically sealed over the entire area where they contact, and when the terminal member and the resin member are hermetically sealed over the entire area where they contact.

[0008] The reason for this is that hermetically sealing only the roughened case portion and the roughened top plate portion reduces stress generated in the resin member during thermal cycle testing, etc., compared to hermetically sealing the entire contact area between the case member and the resin member and the entire contact area between the terminal member and the resin member. Furthermore, in the above-mentioned energy storage device, the roughened case portion and the roughened top plate portion are spaced apart, so stress generated in the portion of the resin member located between the roughened case portion and the roughened top plate portion is reduced. Therefore, cracks are less likely to occur in the seal area between the roughened case portion and the resin member, and the seal area between the roughened top plate portion and the resin member, and it is thought that good sealing can be maintained.

[0009] 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.

[0010] (2) Furthermore, in the energy storage device described in (1), the case roughened portion is composed of a forest of case nanopillars with a height of 50 nm or more, which are formed by particles derived from the metal constituting the case member and linked together in a string of beads, and the top plate roughened portion is composed of a forest of terminal nanopillars with a height of 50 nm or more, which are formed by particles derived from the metal constituting the terminal member and linked together in a string of beads, and the resin member is configured such that the spaces between the forest of case nanopillars are filled with a resin material constituting the resin member, thereby airtightly bonding the resin member to the case roughened portion, and the spaces between the forest of terminal nanopillars are filled with the resin material, thereby airtightly bonding the resin member to the top plate roughened portion.

[0011] In the above-described power storage device, the case roughened portion of the case member is a nano-level (nano-order) roughened portion in which the above-described case nanopillars stand, and a resin material is filled between the standing case nanopillars to airtightly bond the resin member to the case roughened portion. This makes it possible to particularly improve the sealing performance and bonding strength between the case member and the resin member. Furthermore, the top plate roughened portion of the terminal member is a nano-level roughened portion in which the above-described terminal nanopillars stand, and a resin material is filled between the standing terminal nanopillars to airtightly bond the resin member to the top plate roughened portion. This makes it possible to particularly improve the sealing performance and bonding strength between the terminal member and the resin member.

[0012] (3) Still another aspect is a connector comprising a case member having an insertion hole, a terminal member inserted into the insertion hole of the case member, and a resin member that contacts the case member and the terminal member while insulating them and fixing the terminal member to the case member, wherein the terminal member has a plate-shaped terminal top plate portion located on the outside of the case member, and a terminal extension portion that extends from the terminal top plate portion toward the inside of the case member and penetrates the resin member through the insertion hole, and the terminal member and the resin member are hermetically sealed only at a top plate roughening portion that is formed in a band-like ring shape around the entire periphery of the terminal top plate portion on the back surface of the top plate facing the case member, and the case member and the resin member are hermetically sealed at a top plate roughening portion of the terminal top plate portion that is formed in a band-like ring shape around the entire periphery of the terminal top plate portion, and the case member and the resin member are hermetically sealed at a top plate roughening portion of the terminal top plate portion that is formed in a band-like ring shape around the entire periphery of the terminal top plate portion on the back surface of the top plate facing the case member ... and a case roughening process for forming the case roughened portion on the inner surface of the case facing inward, the case roughening process being airtightly sealed only at the case roughening portion, which is formed in a band-like ring shape around the entire circumference of the insertion hole. The method for manufacturing an electricity storage device includes: a case roughening process for performing a surface roughening treatment on a case member before roughening to form the case roughened portion; a terminal forming process for welding a top plate member that forms the terminal top plate portion to an extension member that forms the terminal extension portion to form the terminal member; a top plate roughening process for performing a surface roughening treatment on the top plate member before roughening to form the top plate roughened portion prior to the terminal forming process; and a resin molding process for molding the resin member that is airtightly joined to the case roughened portion and the top plate roughened portion while the terminal member is inserted into the insertion hole of the case member.

[0013] In the manufacturing method of the above-described electric storage device, prior to welding the top plate member and the extension member to form the terminal member, the top plate member is subjected to a surface roughening treatment to form a roughened top plate portion. Therefore, when the roughened top plate portion is formed, the terminal extension portion is not present and does not get in the way, so the roughened top plate portion can be easily formed. Furthermore, prior to the resin molding step, the case member is formed with a roughened case portion, and the terminal member is formed with a roughened top plate portion. Therefore, in the resin molding step, a resin member that is airtightly bonded to the roughened case portion and the roughened top plate portion by the anchor effect can be easily molded.

[0014] Examples of "surface roughening treatment" include physical surface roughening treatment such as shot blasting, sand blasting, and metal spraying, chemical surface roughening treatment such as anodizing and chemical etching, and surface roughening treatment that forms nano-order irregularities by irradiating with a pulsed laser.

[0015] (4) Preferably, the method for manufacturing an electricity storage device according to (3) further comprises a terminal insertion step of inserting the terminal member into the insertion hole of the case member after the terminal formation step and before the resin molding step.

[0016] In the manufacturing method of the above-mentioned energy storage device, after the terminal forming process, the terminal member is inserted into the insertion hole of the case member in the terminal insertion process, and since the case member is not present when the terminal member is formed, the formation of the terminal member (welding of the top plate member and the extension member) can be easily performed.

[0017] (5) Furthermore, in the method for manufacturing an electric storage device described in (3), it is preferable that the extension member has a hole-mounted portion that is disposed within the insertion hole of the case member and welded to the top plate member, and the terminal forming process is a process of welding the hole-mounted portion of the extension member to the top plate member while the hole-mounted portion is disposed within the insertion hole of the case member.

[0018] In the manufacturing method of the above-described electricity storage device, in the terminal forming step, the hole-positioning portion of the extension member is placed in the insertion hole of the case member, and the hole-positioning portion is welded to the top plate member to form the terminal member. In this way, the formation of the terminal member and the insertion of the terminal member into the insertion hole can be performed simultaneously, so there is no need to perform a subsequent step of inserting the terminal member into the insertion hole. In addition, the insertion hole can be designed to be small (it is possible to provide a small insertion hole that cannot insert the terminal member after the terminal member is formed).

[0019] (6) Further, in the method for manufacturing an electricity storage device according to any one of (3) to (5), the roughened case portion is composed of case nanopillars having a height of 50 nm or more, each of which is formed by particles derived from the metal constituting the case member being linked together in a string of beads, and the roughened top plate portion is composed of terminal nanopillars having a height of 50 nm or more, each of which is formed by particles derived from the metal constituting the terminal member being linked together in a string of beads, and the resin member is airtightly bonded to the roughened case portion by filling the spaces between the standing case nanopillars with a resin material constituting the resin member, and the spaces between the standing terminal nanopillars are filled with the resin material, and the resin material is formed on the roughened top plate portion. The case member is hermetically joined, and the case roughening process involves intermittently irradiating the case member before roughening with pulsed laser light while shifting the irradiation position to form the case roughened portion where the case nanopillars stand tall, the top plate roughening process involves intermittently irradiating the top plate member before roughening with pulsed laser light while shifting the irradiation position to form the top plate roughened portion where the terminal nanopillars stand tall, and the resin molding process involves filling the resin material between the case nanopillars standing tall in the case roughened portion and filling the resin material between the terminal nanopillars standing tall in the top plate roughened portion to mold the resin member.This is a method for manufacturing an electricity storage device.

[0020] In the above-described method for manufacturing an electricity storage device, in the case roughening step, a pulsed laser beam is irradiated onto the unroughened case member as described above to form a case roughened portion with a forest of case nanopillars, thereby easily providing a nano-level case roughened portion. Furthermore, in the top plate roughening step, a pulsed laser beam is irradiated onto the unroughened top plate member as described above to form a top plate roughened portion with a forest of terminal nanopillars, thereby easily providing a nano-level top plate roughened portion. Then, in the resin molding step, a resin material is filled between the case nanopillars that stand in the case roughened portion, and the resin member is molded while filling the resin material between the terminal nanopillars that stand in the top plate roughened portion. This allows for particularly high sealing properties and bonding strength between the resin member and the case member and the terminal member. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 is a perspective view of a battery according to an embodiment. [Figure 2] 1 is a partial cross-sectional view of a battery according to an embodiment, taken along the battery height direction and the battery width direction. [Figure 3] 3 is a cross-sectional view of the battery in the vicinity of a resin member in the battery according to the embodiment, taken along the battery height direction and the battery thickness direction. FIG. [Figure 4] 10 is an enlarged cross-sectional view showing a sealing portion between a roughened portion of the case (or a roughened portion of the top plate) and a resin member in the embodiment. FIG. [Figure 5] 3 is a flowchart of a method for manufacturing a battery according to an embodiment. [Figure 6] 10A and 10B are explanatory views showing how a pulsed laser beam is scanned to form a plurality of bowl-shaped recesses and nano-pillars standing tall in the bowl-shaped recesses, in the battery manufacturing method according to the embodiment. [Figure 7] 10A and 10B are explanatory views showing how a terminal member is formed by laser welding a top plate member and an extension member in a method for manufacturing a battery according to an embodiment. [Figure 8] 4 is a cross-sectional view of the vicinity of a resin member corresponding to FIG. 3 according to a comparative embodiment. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0022] An embodiment of the present invention will be described below with reference to the drawings. Fig. 1 shows a perspective view of a battery (energy storage device) 1 of this embodiment, and Fig. 2 shows a partial cross-sectional view of the battery 1. Fig. 3 shows a cross-sectional view of the battery 1 near a resin member 60. Fig. 4 shows an enlarged cross-sectional view of the seal between the case roughened portion 27 (or the top plate roughened portion 47) and the resin member 60. 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 and 2.

[0023] Battery 1 is a rectangular (rectangular) sealed lithium ion secondary battery that is installed in vehicles such as hybrid cars, plug-in hybrid cars, and electric vehicles. Battery 1 is composed of a case 10, an electrode assembly 30 and an electrolyte 5 housed in case 10, and positive and negative terminal members 40 fixed to case 10 via resin members 60. Inside case 10, electrode assembly 30 is covered by an insulating holder 7. This insulating holder 7 is made of an insulating film and has a bag-like shape that opens to an upper side AH1 in the battery height direction AH.

[0024] The electrode assembly 30 is a rectangular parallelepiped laminate, consisting of multiple rectangular positive electrode plates 31 and multiple rectangular negative electrode plates 32 alternately stacked in the battery thickness direction CH with rectangular separators 33 interposed between them, each made of a porous resin film. On one side BH1 of the electrode assembly 30 in the battery width direction BH, the current collector foil of each positive electrode plate 31 extends to the upper side AH1 and overlaps in the battery thickness direction CH to form a positive electrode current collector 30c. This positive electrode current collector 30c is electrically connected to a positive electrode terminal member 40. On the other side BH2 of the electrode assembly 30 in the battery width direction BH, the current collector foil of each negative electrode plate 32 extends to the upper side AH1 and overlaps in the battery thickness direction CH to form a negative electrode current collector 30d. This negative electrode current collector 30d is electrically connected to a negative electrode terminal member 40.

[0025] The case 10 is a rectangular box made of metal (aluminum in this embodiment) and is composed of a case body member 11 and a case lid member 21. In this embodiment, the case lid member 21 corresponds to the aforementioned "case member." The case body member 11 is a bottomed, square cylinder with a rectangular opening 11c and houses the electrode assembly 30 therein. The case lid member 21 is a rectangular plate with a case outer side surface 23 facing the outside DH of the case lid member 21 (the upper side AH1 in this embodiment) and a case inner side surface 24 facing the inside EH of the case lid member 21 (the lower side AH2 in the battery height direction AH in this embodiment), and closes the opening 11c of the case body member 11. The peripheral edge 21f of the case lid member 21 and the opening 11c of the case body member 11 are hermetically welded along their entire periphery. The case lid member 21 is provided with a safety valve 21w that ruptures and opens when the internal pressure of the case 10 exceeds a valve-opening pressure. Further, case lid member 21 is provided with a liquid inlet 21k, which is airtightly sealed with a sealing member 15 in the shape of a disk.

[0026] Rectangular insertion holes 21h are provided in the case lid member 21 near the ends of one side BH1 and the other side BH2 in the battery width direction BH. A positive electrode terminal member 40 made of aluminum is inserted into the insertion hole 21h on the one side BH1, and a positive electrode resin member 60 contacts the case lid member 21 and the terminal member 40 while insulating the case lid member 21 from the terminal member 40, thereby securing the terminal member 40 to the case lid member 21. A negative electrode terminal member 40 made of copper is inserted into the insertion hole 21h on the other side BH2, and a negative electrode resin member 60 contacts the case lid member 21 and the terminal member 40 while insulating the case lid member 21 from the terminal member 40, thereby securing the terminal member 40 to the case lid member 21. The positive and negative terminal members 40 have similar shapes, and the positive and negative resin members 60 also have similar shapes, so they will be described together below.

[0027] The terminal member 40 is formed by welding a top plate member 56 and an extension member 57 (described later) together, and has a terminal top plate portion 43 and a terminal extension portion 53. The positive electrode terminal member 40 is made of aluminum, and the negative electrode terminal member 40 is made of copper. The terminal top panel portion 43 is a rectangular plate having a top panel top surface 44 facing the outside DH (upper side AH1) and a top panel back surface 45 facing the inside EH (lower side AH2), and extends in the battery width direction BH and the battery thickness direction CH.

[0028] The terminal extension portion 53 extends from the terminal top plate portion 43 toward the inner side EH (lower side AH2) and penetrates the resin member 60 through the insertion hole 21h. Specifically, the terminal extension portion 53 is composed of a plate-shaped main body portion 54 and a hole-mounted portion 55 that protrudes from the main body portion 54 toward the upper side AH1 and is disposed within the insertion hole 21h. The main body portion 54 has a rectangular plate shape that is elongated in the battery width direction BH and is located on the inner side EH (lower side AH2) of the case lid member 21. The hole-mounted portion 55 has an upper bottom portion 55a and is cylindrical with a closed upper side AH1. The hole-mounted portion 55 extends from the main body portion 54 through the insertion hole 21h to the terminal top plate portion 43, with the upper bottom portion 55a abutting against the terminal top plate portion 43. The center of the upper bottom portion 55a is welded to the center of the terminal top plate portion 43. The main body 54 of the positive electrode terminal extension 53 is welded to the positive electrode current collector 30c of the electrode body 30. On the other hand, the main body 54 of the negative electrode terminal extension 53 is welded to the negative electrode current collector 30d of the electrode body 30.

[0029] Next, the relationship between the case lid member 21, the terminal member 40, and the resin member 60 will be described. The resin member 60 is in contact with a hole surrounding portion 25 located around the insertion hole 21h on the case surface 22 of the case lid member 21. This hole surrounding portion 25 faces the inner side EH, is part of the aforementioned case inner side surface 24, and has a hole surrounding inner portion 26 that forms a rectangular ring-shaped band around the entire circumference of the insertion hole 21h. Furthermore, this hole surrounding inner portion 26 has a surface-roughened case portion 27 that is a rectangular ring-shaped band around the entire circumference of the insertion hole 21h. In this embodiment, the entire hole surrounding inner portion 26 forms the case roughened portion 27.

[0030] The roughened case portion 27 is subjected to a roughening process using pulsed laser light LB (see FIG. 6 ), which results in a nano-level nano-roughened portion. Specifically, the roughened case portion 27 includes numerous bowl-shaped recesses 28, each having a diameter Da of 30 to 300 μm (approximately 80 μm in this embodiment), arranged in a partially overlapping arrangement (see FIG. 6 ). Furthermore, these bowl-shaped recesses 28 are lined with case nanopillars 29, each of which is formed by a string of particles 29p derived from the metal constituting the case lid member 21, forming a columnar shape with a height ha of 50 nm or more (approximately 200 nm in this embodiment) (see FIGS. 4 and 6 ). The metal constituting the case lid member 21 is aluminum, as described above, and the case nanopillars 29 are made of particles 29p composed of aluminum and aluminum oxide. As will be described later, the case lid member 21 and the resin member 60 are airtightly sealed only at the case roughened portion 27.

[0031] The resin member 60 is in contact with a hole vicinity 42 of the terminal surface 41 of the terminal member 40, which is located near the insertion hole 21h. This hole vicinity 42 includes the above-mentioned top plate back surface 45. Furthermore, this top plate back surface 45 has a roughened top plate portion 47 that is a rectangular ring-shaped band that extends around the entire periphery of the terminal top plate portion 43. In this embodiment, the peripheral edge of the top plate back surface 45 forms the top plate roughened portion 47.

[0032] The roughened top plate portion 47 is a nano-level nano-roughened portion, similar to the roughened case portion 27 of the case lid member 21 described above. That is, the roughened top plate portion 47 has numerous bowl-shaped recesses 48 (see FIG. 6 ), and each recess is filled with terminal nanopillars 49, each of which is composed of particles 49p derived from the metal constituting the terminal member 40, linked together in a string-like pattern to form a columnar shape (see FIGS. 4 and 6 ). The metal constituting the positive electrode terminal member 40 is aluminum, as described above, and the positive electrode terminal nanopillars 49 are made of particles 49p composed of aluminum and aluminum oxide. On the other hand, the metal constituting the negative electrode terminal member 40 is copper, as described above, and the negative electrode terminal nanopillars 49 are made of particles 49p composed of copper and copper oxide. As will be described later, the terminal member 40 and the resin member 60 are airtightly sealed only at the roughened top plate portion 47 .

[0033] The resin member 60 is made of a thermoplastic resin material 61. The resin material 61 includes a thermoplastic main resin (polyphenylene sulfide (PPS) in this embodiment), a thermoplastic elastomer (thermoplastic polyurethane elastomer in this embodiment), and a filler (fibrous glass filler in this embodiment). The resin member 60 contacts the hole surrounding portion 25 of the case surface 22 of the case lid member 21 and contacts the hole vicinity portion 42 of the terminal surface 41 of the terminal member 40, thereby fixing the terminal member 40 to the case lid member 21.

[0034] Furthermore, the resin member 60 is airtightly joined to the roughened case portion 27 over the entire circumference, with the resin material 61 filled between the case nanopillars 29 standing in the roughened case portion 27 in the hole surrounding portion 25 of the case lid member 21. That is, the resin member 60 and the case lid member 21 are airtightly sealed only at the roughened case portion 27. Furthermore, the resin member 60 is airtightly joined to the roughened top plate portion 47 over the entire circumference, with the resin material 61 filled between the terminal nanopillars 49 standing in the roughened top plate portion 47 in the hole vicinity portion 42 of the terminal member 40. That is, the resin member 60 and the terminal member 40 are airtightly sealed only at the roughened top plate portion 47.

[0035] In the battery 1 of this embodiment, the case lid member 21 and the resin member 60 are not airtightly sealed over the entire area where they come into contact, i.e., the entire hole surrounding area 25 is not airtightly sealed over the entire hole surrounding area 25 as a case roughened portion 927 as in the comparative example shown in Fig. 8, but are airtightly sealed only at the case roughened portion 27 (see Fig. 3).Furthermore, the terminal member 40 and the resin member 60 are not airtightly sealed over the entire area where they come into contact, i.e., the entire hole vicinity 42 is not airtightly sealed over the entire hole vicinity 42 as a roughened portion 947 as in Fig. 8, but are airtightly sealed only at the top plate roughened portion 47 (see Fig. 3). This allows the sealing properties between the case cover member 21 and the resin member 60 and the terminal member 40 and the resin member 60 to be maintained well, compared to when the case cover member 21 and the resin member 60 are airtightly sealed around the entire hole surrounding area 25 and the terminal member 40 and the resin member 60 are airtightly sealed around the entire hole vicinity area 42 (see Figure 8).

[0036] The reason for this is believed to be as follows. Specifically, airtight sealing using only the roughened case portion 27 and the roughened top plate portion 47 reduces stress generated in the resin member 60 during thermal cycling tests, compared with airtight sealing using the entire hole-surrounding portion 25 of the case lid member 21 and the entire hole-proximal portion 42 of the terminal member 40. Furthermore, in the battery 1, the roughened case portion 27 and the roughened top plate portion 47 are spaced apart. Specifically, the distance indicated by arrow P in FIG. 3 is longer than the distance indicated by arrow J in FIG. 8 . This reduces stress generated in the portion 60g of the resin member 60 located between the roughened case portion 27 and the roughened top plate portion 47. This is believed to reduce the likelihood of cracks occurring in the seal between the roughened case portion 27 and the resin member 60 and the seal between the roughened top plate portion 47 and the resin member 60, thereby maintaining good sealing performance.

[0037] Furthermore, in this embodiment, the case roughened portion 27 of the case lid member 21 is a nano-level roughened portion consisting of a forest of case nanopillars 29, and a resin material 61 is filled between the forest of case nanopillars 29 to airtightly bond the resin member 60 to the case roughened portion 27. This makes it possible to particularly improve the sealing performance and bonding strength between the case lid member 21 and the resin member 60. Furthermore, the top plate roughened portion 47 of the terminal member 40 is a nano-level roughened portion consisting of a forest of terminal nanopillars 49, and a resin material 61 is filled between the forest of terminal nanopillars 49 to airtightly bond the resin member 60 to the top plate roughened portion 47. This makes it possible to particularly improve the sealing performance and bonding strength between the terminal member 40 and the resin member 60.

[0038] Next, a manufacturing method of the battery 1 will be described (see FIGS. 5 to 7). First, in the case roughening step S1 (see FIG. 5), an unroughened case lid member 21Z is prepared, and this case lid member 21Z is subjected to a surface roughening treatment to form a roughened case portion 27 (see FIG. 6). In this embodiment, pulsed laser light LB is intermittently irradiated onto the hole periphery inner portion 26 of the hole periphery portion 25 on the case surface 22 of the case lid member 21Z while shifting the irradiation position, thereby forming the roughened case portion 27 in which numerous cup-shaped recesses 28 each containing a forest of case nanopillars 29 are arranged in a partially overlapping manner. The laser irradiation conditions were a wavelength of 1064 nm, a peak output of 5 kW, a pulse width of 150 ns, a pitch pb of 75 μm, and a spot diameter of 80 μm.

[0039] At the portion of case lid member 21Z irradiated with pulsed laser beam LB, metal (specifically, aluminum) near case surface 22 melts and turns into vapor. Thereafter, as the temperature of the vapor drops, it turns into aluminum and aluminum oxide particles 29p and accumulates in bowl-shaped recess 28. By intermittently irradiating with pulsed laser beam LB while shifting the irradiation position, particles 29p accumulate in a string and combine to form columns, forming a forest of case nano-pillars 29 (see FIGS. 6 and 4).

[0040] Separately, in the top plate roughening step S2 (see FIG. 5), positive and negative top plate members 56Z before roughening are prepared, and each top plate member 56Z is subjected to a surface roughening treatment to form a roughened top plate portion 47. In this embodiment, pulsed laser light LB is intermittently irradiated onto the peripheral edge of the top plate back surface 45 of the top plate member 56Z while shifting the irradiation position, forming the roughened top plate portion 47 in which numerous cup-shaped recesses 48 with terminal nanopillars 49 standing tall are arranged in a partially overlapping manner (see FIG. 6). The laser irradiation conditions for the positive electrode top plate member 56Z made of aluminum were the same as those for the case roughening step S1. On the other hand, the laser irradiation conditions for the negative electrode top plate member 56Z made of copper were as follows: wavelength: 1064 nm, peak power: 20 kW, pulse width: 50 ns, pitch (pb): 60 μm, and spot diameter: 75 μm.

[0041] Next, in the terminal forming process S3 (see FIG. 5), positive and negative extension members 57 are prepared, and each extension member 57 is welded to a top plate member 56 provided with the above-described top plate roughened portion 47 to form the positive and negative terminal members 40 (see FIG. 7). Specifically, the upper base portion 55a of the hole-mounted portion 55 of the extension member 57 is brought into contact with the top plate rear surface 45 of the top plate member 56. Thereafter, laser light LC is irradiated from the extension member 57 side toward the top plate member 56 side (from bottom to top in FIG. 7) toward the center of the rear surface of the upper base portion 55a of the hole-mounted portion 55 of the extension member 57, thereby welding the upper base portion 55a of the extension member 57 to the top plate member 56, thereby forming the terminal member 40 in which the extension member 57 and the top plate member 56 are integrated. In this embodiment, since the case lid member 21 is not present when the terminal member 40 is formed, the case lid member 21 does not get in the way, and the terminal member 40 can be easily formed.

[0042] Next, in a terminal insertion process S4 (see FIG. 5), the positive and negative terminal members 40 are inserted into a pair of insertion holes 21h of the case lid member 21. Specifically, using a molding die (not shown) having upper and lower dies, the positive and negative terminal members 40 and the case lid member 21 are placed at predetermined positions in the lower die, and the positive and negative terminal members 40 are inserted into the insertion holes 21h of the case lid member 21, respectively. Thereafter, the upper die is moved toward the lower die, and the molding die is closed.

[0043] Next, in the resin molding process S5 (see FIG. 5), with the positive and negative terminal members 40 inserted into the pair of insertion holes 21h of the case lid member 21, respectively, a pair of resin members 60 that contact the case lid member 21 and the positive and negative terminal members 40 are insert-molded. Specifically, molten resin of the resin material 61 is injected into each cavity (not shown) to fill each cavity with the molten resin. At this time, the molten resin of the resin material 61 also fills the spaces between the case nanopillars 29 that stand in rows on the roughened case portion 27 of the case lid member 21 and the spaces between the terminal nanopillars 49 that stand in rows on the roughened top plate portion 47 of the terminal member 40 (see FIG. 4). Then, a pair of resin members 60 are molded so as to be airtightly joined to the case roughened portion 27 of the case lid member 21 and contact the hole surrounding portion 25 of the case lid member 21, and so as to be airtightly joined to the top plate roughened portion 47 of the terminal member 40 and contact the hole vicinity portion 42 of the terminal member 40. Thereafter, the lid assembly (not shown) in which the positive and negative terminal members 40 are fixed to the case lid member 21 via these resin members 60 is removed from the molding die.

[0044] Next, in the electrode assembly connection process S6 (see FIG. 5 ), an electrode assembly 30 is prepared by stacking a positive electrode plate 31, a negative electrode plate 32, and a separator 33, and the positive electrode current collector 30c of the electrode assembly 30 is welded to the main body 54 of the terminal extension 53 of the positive electrode terminal member 40. Also, the negative electrode current collector 30d of the electrode assembly 30 is welded to the main body 54 of the terminal extension 53 of the negative electrode terminal member 40. Thereafter, the electrode assembly 30 is wrapped in a bag-shaped insulating holder 7.

[0045] Next, in the electrode assembly accommodating / case forming process S7, the case body member 11 is prepared, the electrode assembly 30 covered with the insulating holder 7 is inserted into the case body member 11, and the opening 11c of the case body member 11 is closed with the case lid member 21. Then, the opening 11c of the case body member 11 and the peripheral edge 21f of the case lid member 21 are laser-welded airtightly along the entire periphery to form the case 10. Next, in a liquid filling and sealing step S8, the electrolyte 5 is poured into the case 10 through the liquid filling hole 21k, and the electrolyte 5 is impregnated into the electrode body 30. Thereafter, the liquid filling hole 21k is sealed with a sealing member 15 in an airtight manner. Next, in the initial charge / aging step S9, the battery 1 is initially charged. After that, the battery 1 is left standing for a predetermined time to age the battery 1. In this way, the battery 1 is completed.

[0046] In the manufacturing method of battery 1 of this embodiment, as described above, before welding top plate member 56 and extension member 57 to form terminal member 40, top plate member 56 is subjected to a surface roughening treatment to form roughened top plate portion 47. Therefore, when roughened top plate portion 47 is formed, terminal extension portion 53 is not present and does not get in the way, making it easy to form roughened top plate portion 47. Furthermore, prior to resin molding step S5, case roughened portion 27 is formed in case lid member 21, and roughened top plate portion 47 is formed in terminal member 40. Therefore, in resin molding step S5, resin member 60 that is airtightly bonded to case roughened portion 27 and roughened top plate portion 47 by the anchor effect can be easily molded.

[0047] Furthermore, in this embodiment, in the case roughening step S1, pulsed laser light LB is irradiated onto the unroughened case lid member 21Z to form the case roughened portion 27 with a forest of case nanopillars 29, making it easy to provide a nano-level case roughened portion 27. Furthermore, in the top plate roughening step S2, pulsed laser light LB is irradiated onto the unroughened top plate member 56Z to form the top plate roughened portion 47 with a forest of terminal nanopillars 49, making it easy to provide a nano-level top plate roughened portion 47. Then, in the resin molding step S5, resin material 61 is filled between the case nanopillars 29 that forest of the case roughened portion 27, and resin material 61 is filled between the terminal nanopillars 49 that forest of the top plate roughened portion 47 while molding the resin member 60. This makes it possible to particularly improve the sealing properties and bonding strength between the resin member 60 and the case lid member 21 and the terminal members 40.

[0048] In this embodiment, after the terminal members 40 are formed in the terminal forming process S3, the terminal inserting process S4 is performed to insert the terminal members 40 into the insertion holes 21h of the case lid member 21, but this is not limited to this. The formation of the terminal members 40 and the insertion of the terminal members 40 into the insertion holes 21h can also be performed simultaneously. That is, in the terminal forming process S3, the hole-positioning portion 55 of the extension member 57 may be placed in the insertion hole 21h of the case lid member 21, and then the hole-positioning portion 55 and the top plate member 56 may be welded together. In this case, the terminal inserting process S4 is unnecessary. Therefore, the resin molding process S5 is performed after the terminal forming process S3.

[0049] Although the present invention has been described above in accordance with the embodiments, it goes without saying that the present invention is not limited to the embodiments and can be modified and applied as appropriate within the scope of the invention. [Explanation of symbols]

[0050] 1. Battery (energy storage device) 10 cases 21 Case cover member (case member) 21Z (before roughening) case lid material 21h Insertion hole 24 Inside of the case 27 Case roughening part 29 Case Nano Pillar 29p (case nanopillar) particle 30 Electrode body 40 Terminal member 43 Terminal top plate 45 Back of top plate 47 Roughened top surface 49 terminal nano pillars 49p (terminal nanopillar) particle 53 Terminal extension 56 Top plate material 56Z (before roughening) top plate material 57 Extension member 60 Resin parts 61 (resin material) DH (Case lid) Outside EH (Inside of case cover) ha (nanopillar) height LB pulsed laser light S1 Case roughening process S2 Top plate roughening process S3 Terminal formation process S4 Terminal insertion process S5 Resin molding process

Claims

1. a case member having an insertion hole; a terminal member inserted into the insertion hole of the case member; a resin member that insulates the case member from the terminal members, contacts the case member, and fixes the terminal members to the case member. An electricity storage device, The terminal member is a plate-shaped terminal top plate portion located on the outside of the case member; a terminal extension portion that extends from the terminal top plate portion toward the inside of the case member, passes through the insertion hole, and penetrates the resin member, The terminal member and the resin member are the terminal top plate portion is airtightly sealed only at a top plate roughening portion formed in a band-like annular shape around the entire periphery of the terminal top plate portion on a back surface of the top plate facing the case member, The case member and the resin member are The case member is airtightly sealed only at a roughened case portion formed in a band-like shape around the entire circumference of the insertion hole on the case inner surface facing the inward. Energy storage device.

2. The electricity storage device according to claim 1 , The case roughening portion is Particles derived from the metal constituting the case member are linked together in a string to form columnar shapes, forming case nano-columns with a height of 50 nm or more, The top plate roughening portion is Particles derived from the metal constituting the terminal member are linked together in a string to form pillars, forming terminal nanopillars with a height of 50 nm or more, The resin member is The resin material constituting the resin member is filled between the forest of case nano-pillars, and the resin member is airtightly bonded to the case roughened portion, and The resin material is filled between the standing terminal nano-pillars, and the terminal nano-pillars are airtightly bonded to the roughened top plate portion. Energy storage device.

3. a case member having an insertion hole; a terminal member inserted into the insertion hole of the case member; a resin member that insulates the case member from the terminal members, contacts the case member, and fixes the terminal members to the case member; The terminal member is a plate-shaped terminal top plate portion located on the outside of the case member; a terminal extension portion that extends from the terminal top plate portion toward the inside of the case member, passes through the insertion hole, and penetrates the resin member, The terminal member and the resin member are the terminal top plate portion is airtightly sealed only at a top plate roughening portion formed in a band-like annular shape around the entire periphery of the terminal top plate portion on a back surface of the top plate facing the case member, The case member and the resin member are The case member is airtightly sealed only at a roughened case portion formed in a band-like shape around the entire circumference of the insertion hole on the case inner surface facing the inward. A method for manufacturing an electricity storage device, comprising: a case roughening step of performing a surface roughening treatment on a case member before roughening to form the roughened case portion; a terminal forming step of welding a top plate member constituting the terminal top plate portion and an extension member constituting the terminal extension portion to form the terminal member; a top plate roughening step of performing a surface roughening treatment on a top plate member before the terminal forming step to form the top plate roughened portion; a resin molding step of molding the resin member that is airtightly joined to the case roughened portion and the top plate roughened portion in a state in which the terminal member is inserted into the insertion hole of the case member. A method for manufacturing an electricity storage device.

4. A method for manufacturing the electricity storage device according to claim 3, The case roughening portion is Particles derived from the metal constituting the case member are linked together in a string to form columnar shapes, forming case nano-columns with a height of 50 nm or more, The top plate roughening portion is Particles derived from the metal constituting the terminal member are linked together in a string to form pillars, forming terminal nanopillars with a height of 50 nm or more, The resin member is The resin material constituting the resin member is filled between the forest of case nano-pillars, and the resin member is airtightly bonded to the case roughened portion, and the resin material is filled between the adjacent ones of the terminal nano-pillars standing in a forest, and the adjacent ones of the terminal nano-pillars are airtightly bonded to the roughened top plate portion; The case roughening step includes: pulsed laser light is intermittently irradiated onto the case member before roughening while shifting the irradiation position, thereby forming the case roughened portion in which the case nano-pillars stand; The top plate roughening step includes: irradiating the unroughened top plate member with pulsed laser light intermittently while shifting the irradiation position, thereby forming the roughened top plate portion in which the terminal nanopillars stand; The resin molding step includes: The resin material is filled between the case nano-pillars standing in the case roughened portion, and the resin material is filled between the terminal nano-pillars standing in the top plate roughened portion, thereby molding the resin member. A method for manufacturing an electricity storage device.

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