Metal-resin bonded body and method for manufacturing the same

Abstract

To provide a metal-resin joint and the like, in which a resin member is bonded and fixed to a metal member, which can improve a sealing property between the metal member and the resin member.SOLUTION: A metal-resin joint 100 includes a metal member 50 having a continuous band-shaped resin joined portion 51 on a metal surface 50m, and a resin member 70 joined and fixed to the resin joined portion 51 over the entire periphery IAH in a circumferential direction. The resin joined portion 51 has a continuous band-shaped recess arranged portion 53 in which numerous bowl-shaped recesses 57 are arranged while partially overlapping, and the recess arranged portion 53 includes a continuous band-shaped nano-roughened portion 55 on which high nano-columns 58H stand numerously, and a non-nano-roughened portion 56. The resin member 70 is joined to the nano-roughened portion 55 over the entire periphery with a resin material 75 filling gaps between each of the high nano-columns 58H standing numerously on the nano-roughened portion 55.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a metal-resin bonded body in which a resin member is bonded and fixed to a metal member, and a method for producing the metal-resin bonded body. [Background technology]

[0002] A metal-resin bonded body in which a resin member is bonded and fixed to a metal member includes a metal member having a band-shaped (band-shaped and ring-shaped) resin bonded portion on the metal surface and a resin member bonded to the resin bonded portion along the entire circumferential direction and fixed to the metal member. Such metal-resin bonded bodies are included in, for example, power storage devices such as batteries. Specifically, there is a battery in which positive and negative terminal members are fixed to a rectangular plate-shaped case lid member constituting a rectangular box-shaped case via a resin member. The terminal members are inserted into through holes provided in the case lid member and extend from the inside to the outside of the case. The resin member is airtightly bonded to the case lid member while insulating them from the terminal members, thereby fixing the terminal members to the case lid member. In such a battery, the terminal members (metal members) and the resin members bonded and fixed thereto correspond to the above-mentioned "metal-resin bonded body." The case lid member (metal member) and the resin members bonded and fixed thereto also correspond to the "metal-resin bonded body." The above-mentioned battery is disclosed in, for example, Patent Document 1 (see FIGS. 1 and 2, etc.). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-079172 Summary of the Invention [Problem to be solved by the invention]

[0004] Another possible method for roughening the surface of a resin joint between metal members is to intermittently irradiate the resin joint between the metal members with pulsed laser light while shifting the irradiation position, thereby roughening the resin joint at the nano-level (nano-order). That is, a large number of bowl-shaped depressions are formed in the resin joint by irradiating the resin joint with pulsed laser light, forming a depression arrangement area. Furthermore, nano-level nano-columns are formed on the surface of the bowl-shaped depressions, in which particles derived from the metal that makes up the metal member are linked together in a string-like pattern. Forming depression arrangement areas in the resin joint between the metal members in this way is thought to enable a strong and highly airtight bond between the metal member and the resin member.

[0005] However, the inventors' investigations have revealed that even when a recess arrangement portion is formed in a resin bonded portion as described above, the above-mentioned nanopillars or nanopillars of appropriate size (height) may not be formed on the surface of the bowl-shaped recess depending on the order and position of irradiation with pulsed laser light (the order and arrangement of the bowl-shaped recesses). That is, it has been found that in the recess arrangement portion, in addition to nano-roughened portions with a forest of nanopillars of appropriate height, there are also non-nano-roughened portions with no nanopillars or low nanopillars. Specifically, it has been found that when a recess arrangement portion is formed by scanning with pulsed laser light to arrange multiple rows of recess-connected regions, each of which has multiple bowl-shaped recesses connected in a row, the last recess-connected region formed is a non-nano-roughened portion with no nanopillars or low nanopillars.

[0006] Furthermore, since the non-nano-roughened portion does not allow the resin member to be firmly and airtightly bonded to the metal member, it has been found that the sealing between the metal member and the resin member is insufficient depending on the arrangement pattern of the non-nano-roughened portion. For example, in the above-mentioned battery, moisture from outside the battery may penetrate into the battery through the gap between the terminal member and the resin member, or between the case lid member and the resin member. Conversely, the electrolyte contained inside the battery may leak out of the battery through the gap between the terminal member and the resin member, or between the case lid member and the resin member.

[0007] The present invention has been made in consideration of the current situation, and provides a metal-resin bonded body in which a resin member is joined and fixed to a metal member, which can improve the sealing properties between the metal member and the resin member, and a method for manufacturing the metal-resin bonded body. [Means for solving the problem]

[0008] (1) One aspect of the present invention for solving the above-mentioned problems is a metal resin joined body including a metal member having a band-annular resin joint portion on a metal surface, and a resin member joined to the resin joint portion over the entire circumference in the circumferential direction and fixed to the metal member, wherein the resin joint portion of the metal member has a band-annular shape over the entire circumference in the circumferential direction, and a recess arrangement portion in which a number of bowl-shaped recesses having a diameter of 30 to 300 μm are arranged in a row with some of them overlapping, and the recess arrangement portion is ,before The nanopillars are formed by connecting particles of 100 nm or less in diameter derived from the metal that constitutes the metal member in a string-like manner, and are tall nanopillars with a height of 40 nm or more. The bowl-shaped recesses are arranged side by side to form a ring-shaped band extending around the entire circumference in the circumferential direction. The nano-roughened portion and the nano-pillars are not present. the bowl-shaped recess or a forest of low nanopillars with a height of less than 40 nm The bowl-shaped recesses each having The resin member includes a non-nano-roughened portion, and the resin member is formed by filling the spaces between the high nano-columns that stand in the nano-roughened portion with a resin material that forms the resin member, and bonding the resin member to the nano-roughened portion around its entire circumference, and the space between the metal member and the resin member is airtightly sealed between one side and the other side in the width direction of the nano-roughened portion.

[0009] In the metal-resin bonded body described above, a band-shaped (band-shaped and ring-shaped) recess-arrangement portion in which numerous bowl-shaped recesses are arranged is provided in a band-shaped resin bonded portion of the metal surface of the metal member. This recess-arrangement portion includes a non-nano-roughened portion in which there are no nanopillars or in which low nanopillars stand tall (not properly nano-roughened at the nano-level), but also includes a nano-roughened portion in which a band-shaped region in which high nanopillars stand tall (properly nano-roughened at the nano-level) forms a band-shaped ring. The resin member is bonded to the nano-roughened portion around its entire circumference by filling the spaces between the high nanopillars standing tall in the nano-roughened portion with a resin material, thereby providing an airtight seal between the metal member and the resin member and between one side and the other side in the width direction of the nano-roughened portion. Therefore, in the metal-resin bonded body described above, good sealing performance can be achieved between the metal member and the resin member, despite the presence of a non-nano-roughened portion in which the recess-arrangement portion does not properly nano-roughen.

[0010] The "recessed portion" may be a partial region of the resin joint, or the entire region of the resin joint may be a recessed portion. The "annular nano-roughened portion" preferably has a width of at least 150 μm, which allows for more effective airtight sealing between the two widthwise sides of the nano-roughened portion. The "metal member" preferably contains one of aluminum, copper, iron, tin, titanium, zinc, chromium, and nickel as its main component. This makes it easy to provide a recess arrangement portion with multiple bowl-shaped recesses arranged in the resin joint portion of the metal member.

[0011] (2) In the metal-resin bonded body described in (1), the metal member may be a rod-shaped member having an outer peripheral surface, and the metal member may have the recessed portion including the nano-roughened portion in a band-like shape surrounding the outer peripheral surface, and the resin member may be a ring-shaped member surrounding the outer peripheral surface of the metal member, and may be bonded to the nano-roughened portion in a band-like shape around the entire circumference.

[0012] In the above-described metal-resin bonded body, the metal member is rod-shaped, and the resin member is annular and surrounds the outer peripheral surface of the metal member. The metal member is provided with a recessed portion including a band-shaped nano-roughened portion that surrounds the outer peripheral surface, and the resin member is bonded to the entire circumference of the band-shaped nano-roughened portion. Therefore, the outer peripheral surface of the metal member and the resin member can be airtightly separated into two sides in the width direction of the nano-roughened portion, i.e., one side and the other in the axial direction of the metal member, by the band-shaped nano-roughened portion.

[0013] (3) In the metal-resin bonded body described in (1), the metal member has a form having a through hole, the metal surface has an opening peripheral surface surrounding the opening edge of the through hole, the opening peripheral surface has the recessed portion including the ring-shaped nano-roughened portion surrounding the opening edge, and the resin member is preferably bonded to the ring-shaped nano-roughened portion surrounding the opening edge over the entire circumference.

[0014] In the above-described metal-resin bonded body, the metal member has a through hole. The metal surface of the metal member has a recessed portion including a ring-shaped nano-roughened portion surrounding the edge of the opening. The resin member is bonded to the entire circumference of the ring-shaped nano-roughened portion. Therefore, the ring-shaped nano-roughened portion can airtightly separate the opening peripheral surface of the metal member from the resin member into two widthwise sides of the nano-roughened portion, i.e., the inside and outside of the opening peripheral surface.

[0015] (4) Another embodiment is a metal member having a band-shaped resin joint on a metal surface, and a metal plate bonded to the resin joint over the entire circumference of the resin joint. genus and a resin member fixed to a member, wherein the resin joint portion of the metal member has a recessed portion arranged in a band-like annular shape over the entire circumference in the circumferential direction, and a number of bowl-shaped recesses each having a diameter of 30 to 300 μm are arranged in a line with some of the recesses overlapping each other, and the recessed portion is ,before The nanopillars are formed by connecting particles of 100 nm or less in diameter derived from the metal that constitutes the metal member in a string-like manner, and are tall nanopillars with a height of 40 nm or more. The bowl-shaped recesses are arranged side by side to form a ring-shaped band extending around the entire circumference in the circumferential direction. The nano-roughened portion and the nano-pillars are not present. the bowl-shaped recess or a forest of low nanopillars with a height of less than 40 nm The bowl-shaped recesses each having a non-nano-roughened portion, wherein the resin member is bonded to the nano-roughened portion over its entire circumference by filling the spaces between the high nano-columns that stand in the nano-roughened portion with a resin material that forms the resin member, and wherein the space between one side and the other side in the width direction of the nano-roughened portion is airtightly sealed between the metal member and the resin member, the method comprising: a recess forming step of intermittently irradiating the resin bonded portion of the metal member with pulsed laser light while shifting the irradiation position, thereby forming a large number of the bowl-shaped recesses and forming the recess arrangement portion; and a resin forming step of forming the resin member bonded to the metal member after the recess forming step, wherein the recess forming The process is a method for manufacturing a metal-resin joint, in which the pulsed laser light is scanned in a line direction that intersects with the width direction of the resin joint to form a line of recessed portion-connected regions in the line direction with some overlapping, and this is repeated in multiple rows in an array direction that is perpendicular to the line direction to arrange the multiple rows of recessed portion-connected regions with some overlapping in the array direction, thereby forming the recessed portion arrangement section including the nano-roughened portion, and the resin forming process is a method for manufacturing a metal-resin joint, in which the resin material is filled between the high nano-pillars that stand in the nano-roughened portion, and the resin material is airtightly bonded to the nano-roughened portion around its entire circumference, and the resin member is formed to be bonded to the resin joint around its entire circumference.

[0016] In the above-described method for manufacturing a metal-resin bonded body, the recess forming step scans a pulsed laser beam to form a plurality of recess-connected regions in the array direction, each of which has a plurality of bowl-shaped recesses connected in a row in the array direction, thereby forming a recess arrangement region including a nano-roughened portion, thereby easily forming the nano-roughened portion. Then, in the resin forming step, the resin member is formed while filling the spaces between the tall nano-columns that stand in the nano-roughened portion with a resin material, thereby easily forming a resin member that is airtightly bonded to the nano-roughened portion around its entire circumference.

[0017] In addition, in the "resin forming process," methods for forming a resin member include, for example, a method of forming (molding) a resin member by insert molding using a metal member, and a method of forming a resin member by applying a liquid resin material to the resin joint portion of a metal member and drying it.

[0018] (5) In the method for producing a metal-resin bonded body described in (4), the recess formation step is preferably a method for producing a metal-resin bonded body in which the recess-connected region is formed in a multi-stage band-like ring shape or a multi-layer spiral or vortex shape, thereby forming the recess arrangement portion including the nano-roughened portion.

[0019] In the above-described method for manufacturing a metal-resin bonded body, in the recess formation step, the recess-connected region is formed in a multi-stage band-like ring shape or a multi-layer spiral or whorl shape to form a recess arrangement portion including a nano-roughened portion, so that a band-like nano-roughened portion can be easily formed in the resin bonded portion of the metal member. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a perspective view of a battery having a first metal-resin joined body and a second metal-resin joined body according to an embodiment. [Figure 2] 1 is a partially cutaway cross-sectional view along the battery height direction and the battery width direction of a battery having a first metal-resin bonded body and a second metal-resin bonded body according to an embodiment. [Figure 3] 3 is a partially enlarged cross-sectional view of a battery having a first metal-resin joined body and a second metal-resin joined body according to an embodiment, taken along the battery height direction and the battery thickness direction near a resin member. FIG. [Figure 4] 4 is a partially enlarged plan view of a resin joint (area A and area B in FIG. 3) in the embodiment. FIG. [Figure 5] FIG. 2 is a partially enlarged cross-sectional view of a nano-roughened portion according to an embodiment. [Figure 6] FIG. 10 is a partially enlarged cross-sectional view showing tall nano-pillars standing in a bowl-shaped recess in the nano-roughened portion according to the embodiment. [Figure 7]FIG. 2 is a partially enlarged cross-sectional view of a non-nano-roughened portion according to an embodiment. [Figure 8] FIG. 10 is a partially enlarged cross-sectional view showing small nano-pillars standing in a bowl-shaped recess in a non-nano-roughened portion according to an embodiment. [Figure 9] 1 is a flowchart of a method for manufacturing a battery including a method for manufacturing a metal-resin bonded body according to an embodiment. [Figure 10] 10 is an explanatory view showing how a plurality of bowl-shaped recesses are formed by scanning with pulsed laser light in a first recess-forming step (second recess-forming step) in the method for manufacturing a metal-resin bonded body according to the embodiment. FIG. [Figure 11] 1A and 1B are explanatory views of a resin forming step in a manufacturing method of a metal resin bonded body according to an embodiment, in which FIG. 1A shows a state in which positive and negative terminal members are inserted into the through holes of a case lid member, and FIG. 1B shows a state in which a pair of resin members are molded. DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a perspective view of a battery (electricity storage device) 1 having a first metal-resin bonded body 100 and a second metal-resin bonded body 200 according to this embodiment, and Fig. 2 is a partially cutaway cross-sectional view of the battery 1. Fig. 3 is an enlarged partial cross-sectional view of the battery 1 near a resin member 70. In the following description, the battery height direction AH, battery width direction BH, and battery thickness direction CH of the battery 1 will be defined as the directions shown in Figs. 1 to 3.

[0022] This battery 1 is a rectangular (rectangular) sealed lithium ion secondary battery that can be installed in vehicles such as hybrid cars, plug-in hybrid cars, and electric cars. The battery 1 is composed of a case 10 made up of a case body member 20 and a case lid member 30, an electrode assembly 40 housed in the case 10, and positive and negative terminal members 50 fixed to the case 10 via resin members 70. The electrode assembly 40 is covered within the case 10 by a bag-shaped insulating holder 7 made of insulating film. The case 10 also contains an electrolyte 5, a portion of which is impregnated into the electrode assembly 40 and the remainder of which is pooled on the bottom wall of the case 10.

[0023] This battery 1 includes two first metal-resin bonded bodies 100 and two second metal-resin bonded bodies 200. Specifically, the positive and negative terminal members (metal members) 50 and the resin members 70 bonded and fixed thereto are each the first metal-resin bonded bodies 100 (hereinafter also simply referred to as "metal-resin bonded bodies 100"). Furthermore, the case lid member (metal member) 30 and the positive and negative resin members 70 bonded and fixed thereto are each the second metal-resin bonded bodies 200 (hereinafter also simply referred to as "metal-resin bonded bodies 200").

[0024] The case 10 is a rectangular box made of metal (aluminum in this embodiment), and is configured from a case body member 20 in the shape of a bottomed square cylinder with a rectangular opening 20c, which houses the electrode assembly 40 inside, and a rectangular plate-shaped case lid member 30 which closes the opening 20c of the case body member 20. The opening 20c of the case body member 20 and the peripheral edge 30f of the case lid member 30 are hermetically welded all around. The case lid member 30 is provided with a safety valve 11 that ruptures and opens when the internal pressure of the case 10 exceeds a valve opening pressure. The case lid member 30 is also provided with a liquid inlet 30k, which is hermetically sealed with a disk-shaped sealing member 12 made of aluminum.

[0025] The electrode assembly 40 is a rectangular parallelepiped laminate, and is formed by alternately stacking multiple rectangular positive electrode plates 41 and multiple rectangular negative electrode plates 42 in the battery thickness direction CH with rectangular separators 43 made of porous resin films sandwiched between them. On one side BH1 of the electrode assembly 40 in the battery width direction BH, the current collecting foils of the positive electrode plates 41 overlap in the battery thickness direction CH to form a positive electrode current collecting portion 40c. This positive electrode current collecting portion 40c is electrically connected to a positive electrode terminal member 50, which will be described later. On the other side BH2 of the electrode assembly 40 in the battery width direction BH, the current collecting foils of the negative electrode plates 42 overlap in the battery thickness direction CH to form a negative electrode current collecting portion 40d. This negative electrode current collecting portion 40d is electrically connected to a negative electrode terminal member 50, which will be described later.

[0026] Rectangular through-holes 30h are provided in the case lid member 30 near the ends of one side BH1 and the other side BH2 in the battery width direction BH, penetrating the case lid member 30. A positive electrode terminal member 50 made of aluminum is inserted into the through-hole 30h on the one side BH1, and the terminal member 50 is fixed to the case lid member 30 while being insulated from the case lid member 30 via a resin member 70. A negative electrode terminal member 50 made of copper is inserted into the through-hole 30h on the other side BH2, and the terminal member 50 is fixed to the case lid member 30 while being insulated from the case lid member 30 via the resin member 70.

[0027] The terminal member 50 is made by pressing metal plates (aluminum plate for the positive electrode and copper plate for the negative electrode) and has a rod shape extending in the axial direction EH (the same direction as the battery height direction AH in this embodiment). The terminal member 50 is composed of a rectangular terminal top plate portion 50a located on one side EH1 in the axial direction EH (a side AH1 above the case lid member 30 in the battery height direction AH) and extending in the battery width direction BH and the battery thickness direction CH, and a terminal extension portion 50b extending from the terminal top plate portion 50a to the other side EH2 in the axial direction EH (a side AH2 below the battery height direction AH). The terminal extension portion 50b bends at an end of the terminal top plate portion 50a on the one side CH1 in the battery thickness direction CH, extends downward AH2, passes through the through-hole 30h of the case lid member 30, and further penetrates the resin member 70 to extend downward AH2. The positive electrode terminal extension 50b is welded to the positive electrode current collector 40c of the electrode body 40 at the tip of the lower side AH2, and is electrically connected to the positive electrode current collector 40c. The negative electrode terminal extension 50b is welded to the negative electrode current collector 40d of the electrode body 40 at the tip of the lower side AH2, and is electrically connected to the negative electrode current collector 40d.

[0028] Of the metal surface 50m of the terminal member 50, the band-shaped portion to which the resin member 70 is bonded is the resin joint portion 51, and the portion to which the resin member 70 is not bonded is the non-resin joint portion 52. Specifically, of the surface of the terminal top plate portion 50a, the inner surface and four side surfaces facing the lower side AH2 and the portion of the outer peripheral surface 50mc of the terminal extension portion 50b that is located inside the resin member 70 on the upper side AH1 are the resin joint portion 51. On the other hand, of the surface of the terminal top plate portion 50a, the top surface facing the upper side AH1 and the portion of the outer peripheral surface 50mc of the terminal extension portion 50b that protrudes and is exposed from the resin member 70 to the lower side AH2 are the non-resin joint portion 52.

[0029] Next, the resin joint portion 51 will be described in detail (see also FIGS. 4 to 8). Note that FIG. 4 shows an enlarged view of the area A of the resin joint portion 51, which is surrounded by a dashed line in FIG. 3. The resin joint portion 51 of the terminal member 50 is composed of a recessed portion arrangement portion 53 in which numerous bowl-shaped recessed portions 57 are arranged, and a non-recessed portion arrangement portion 54 in which no bowl-shaped recessed portions 57 are arranged. Specifically, the recessed portion arrangement portion 53 is a rectangular, annular portion of the resin joint portion 51 that surrounds the outer peripheral surface 50mc and is formed by the central portion in the battery height direction AH of the terminal extension portion 50b located inside the resin member 70. Meanwhile, the non-recessed portion arrangement portion 54 is a portion of the resin joint portion 51 formed by the terminal top plate portion 50a and the upper side AH1 and lower side AH2 of the terminal extension portion 50b located inside the resin member 70.

[0030] The recess arrangement portion 53 is a rectangular band-like annular shape extending in the battery height direction AH around the entire circumferential direction IAH (in this embodiment, the circumferential direction along the battery width direction BH and the battery thickness direction CH) of the resin joint portion 51. In the recess arrangement portion 53, a large number of bowl-shaped recesses 57, each having a diameter Db of 30 to 300 μm (in this embodiment, the diameter Db is approximately 80 μm for the positive electrode terminal member 50 and approximately 75 μm for the negative electrode terminal member 50), are arranged side by side with some of them overlapping each other.

[0031] Furthermore, the recess arrangement portion 53 is made up of a nano-roughened portion 55 and a non-nano-roughened portion 56. Specifically, of the recess arrangement portion 53 having a rectangular band-like annular shape extending in the battery height direction AH, the rectangular band-like annular portion forming the end of the lower side AH2 is the non-nano-roughened portion 56, and the rectangular band-like annular portion forming the portion above this on the upper side AH1 is the nano-roughened portion 55. The nano-roughened portion 55 is made up of nanopillars 58 formed by connecting particles 58p derived from the metal constituting the terminal member 50 in a string-like pattern, forming a forest of tall nanopillars 58H with a height ha of 40 nm or more (in this embodiment, the height ha is approximately 200 nm) (see FIGS. 5 and 6). The metal constituting the positive electrode terminal member 50 is aluminum, and the positive electrode nanopillars 58 are made of particles 58p made of aluminum and aluminum oxide. The metal constituting the negative electrode terminal member 50 is copper, and the negative electrode nanopillars 58 are made of particles 58p made of copper and copper oxide. The positive and negative electrode particles 58p have a diameter Da of 100 nm or less (in this embodiment, the diameter Da is approximately 30 nm). On the other hand, although the non-nano-roughened portion 56 is forested with the above-mentioned nanopillars 58, these nanopillars 58 are low nanopillars 58L with a height ha of less than 40 nm (in this embodiment, the height ha = less than 20 nm) (see Figures 7 and 8).

[0032] Next, the resin joint portion 31 of the case lid member 30 will be described (see FIGS. 3 to 8). FIG. 4 shows an enlarged view of the resin joint portion 31, part B, surrounded by a dashed line in FIG. 3. The annular band-shaped portions of the metal surface 30m of the case lid member 30 to which the resin members 70 are bonded are the resin joint portions 31, and the non-resin joint portions 32 are the portions to which the resin members 70 are not bonded. Specifically, the metal surface 30m of the case lid member 30 includes a pair of rectangular annular opening peripheral surfaces 30me surrounding a pair of opening edges 30he of the positive electrode through-hole 30h and a pair of rectangular annular opening peripheral surfaces 30me surrounding a pair of opening edges 30he of the negative electrode through-hole 30h. Each through-hole 30h extends in the battery height direction AH, with one opening edge 30he and opening peripheral surface 30me located on an upper side AH1 and the other opening edge 30he and opening peripheral surface 30me located on a lower side AH2. Of the metal surface 30m of the case lid member 30, the pair of opening peripheral surfaces 30me and the inner peripheral surface of the through hole 30h connecting them form the resin joint portion 31. On the other hand, of the metal surface 30m of the case lid member 30, the portions other than the opening peripheral surfaces 30me and the inner peripheral surfaces of the through hole 30h form the non-resin joint portion 32.

[0033] The resin joint portion 31 of the case lid member 30 is composed of a recess arrangement portion 33 in which a large number of bowl-shaped recesses 37 are arranged, and a non-recess arrangement portion 34 in which no bowl-shaped recesses 37 are arranged. Specifically, of the resin joint portion 31, the radial center portions of the pair of opening peripheral surfaces 30me are the recess arrangement portions 33, and the radial inner portion FH1 and the radial outer portion FH2 of the opening peripheral surfaces 30me and the inner peripheral surface of the through hole 30h are the non-recess arrangement portions 34. Each recess arrangement portion 33 is a rectangular ring-shaped band that extends in the battery width direction BH and the battery thickness direction CH around the entire circumferential direction IBH of the resin joint portion 31 (in this embodiment, the circumferential direction along the battery width direction BH and the battery thickness direction CH). In the recess arrangement section 33, a large number of bowl-shaped recesses 37, each having a diameter Db of 30 to 300 μm (in this embodiment, the diameter Db is approximately 80 μm), are arranged side by side with some of them overlapping each other.

[0034] Furthermore, each recess arrangement portion 33 is made up of a nano-roughened portion 35 and a non-nano-roughened portion 36. Specifically, within the recess arrangement portion 33, the rectangular band-shaped annular portion that forms the periphery of the outer FH2 is the non-nano-roughened portion 36, and the rectangular band-shaped annular portion that forms the inner FH1 portion is the nano-roughened portion 35. The nano-roughened portion 35 is made up of nano-pillars 38 formed by connecting particles 38p derived from the metal constituting the case lid member 30 in a string-like pattern, and is composed of tall nano-pillars 38H with a height ha of 40 nm or more (in this embodiment, the height ha is approximately 200 nm) (see FIGS. 5 and 6). The metal constituting the case lid member 30 is aluminum, and the nano-pillars 38 are made up of particles 38p of aluminum and aluminum oxide with a diameter Da of 100 nm or less (in this embodiment, the diameter Da is approximately 30 nm). On the other hand, although the non-nano-roughened portion 36 is forested with the above-mentioned nanopillars 38, these nanopillars 38 are low nanopillars 38L with a height ha of less than 40 nm (height ha = less than 20 nm in this embodiment) (see Figures 7 and 8).

[0035] Next, the resin member 70 will be described. The resin member 70 is formed by insert molding using a resin material 75 containing a thermoplastic main resin (specifically, polyphenylene sulfide (PPS)), a thermoplastic elastomer, and a filler (specifically, a fibrous glass filler). The resin member 70 is hermetically bonded and fixed to the case lid member 30 and the terminal members 50 while insulating them from each other.

[0036] In the first metal-resin joined body 100 including the terminal member 50 and the resin member 70, the resin member 70 is annular and surrounds the outer peripheral surface 50mc of the terminal member 50. The resin member 70 is joined to the band-shaped resin joint portion 51 of the outer peripheral surface 50mc over the entire circumference in the circumferential direction IAH, thereby being fixed to the terminal member 50. Specifically, the resin member 70 is joined to the band-shaped nano-roughened portion 55 over the entire circumference in the circumferential direction IAH by filling the spaces between the tall nano-columns 58H that stand in the nano-roughened portion 55 of the recessed portion arrangement portion 53 in the resin joint portion 51 with the resin material 75. This provides an airtight seal between the terminal member 50 and the resin member 70 between one side LAH1 (in this embodiment, the same direction as the upper side AH1) and the other side LAH2 (in this embodiment, the same direction as the lower side AH2) in the width direction LAH (in this embodiment, the same direction as the battery height direction AH) of the nano-roughened portion 55.

[0037] In the second metal-resin bonded body 200 composed of the case lid member 30 and the resin member 70, the resin member 70 is bonded to the band-shaped resin bonding portion 31 on the metal surface 30m of the case lid member 30 over the entire circumference in the circumferential direction IBH, and is fixed to the case lid member 30. Specifically, the resin bonding portion 31 of the case lid member 30 has a pair of band-shaped recessed portion arrangement portions 33 surrounding the opening edges 30he of the upper side AH1 and lower side AH2 of the through-hole 30h, as described above. The resin material 75 described above is filled between the tall nano-columns 38H standing in the nano-roughened portions 35 of these recessed portion arrangement portions 33, and the resin member 70 is bonded to each of the pair of nano-roughened portions 35 over the entire circumference in the circumferential direction IBH. This results in an airtight seal between the case lid member 30 and the resin member 70, between one side LBH1 (inner side FH1) and the other side LBH2 (outer side FH2) in the width direction LBH (in this embodiment, the same direction as the radial direction of the through hole 30h) of each nano-roughened portion 35.

[0038] In the metal-resin bonded bodies 100, 200 of the present embodiment, a band-shaped recess-arrangement portion 53, 33 in which numerous bowl-shaped recesses 57, 37 are arranged is provided in a band-shaped resin bonding portion 51, 31 of the metal surfaces 50m, 30m of the metal members (terminal member 50 and case lid member 30). The recess-arrangement portion 53, 33 includes a non-nano-roughened portion 56, 36 where low nanopillars 58L, 38L stand tall (not properly nano-roughened), but also includes a nano-roughened portion 55, 35 where a band-shaped region where high nanopillars 58H, 38H stand tall (properly nano-roughened) forms a band-shaped region. The resin member 70 is joined to the nano-roughened portion 55, 35 over the entire circumference thereof by filling the spaces between the tall nano-columns 58H, 38H that form in the nano-roughened portion 55, 35 with a resin material 75, and the resin member 70 is hermetically sealed between the terminal member 50 and the case lid member 30 and the resin member 70 on one side LAH1, LBH1 and the other side LAH2, LBH2 in the width direction LAH, LBH of the nano-roughened portion 55, 35. Therefore, in the metal-resin joined bodies 100, 200, good sealing can be achieved between the terminal member 50 and the case lid member 30 and the resin member 70, despite the presence of the non-nano-roughened portions 56, 36 that are not appropriately nano-roughened in the recess arrangement portions 53, 33.

[0039] In the first metal-resin joined body 100, the terminal member 50 is rod-shaped, and the resin member 70 is annular and surrounds the outer peripheral surface 50mc of the terminal member 50. The terminal member 50 is provided with a recessed portion 53 including a band-shaped nano-roughened portion 55 that surrounds the outer peripheral surface 50mc, and the resin member 70 is joined around the entire circumference of this band-shaped nano-roughened portion 55. Therefore, the outer peripheral surface 50mc of the terminal member 50 and the resin member 70 can be airtightly separated, with the band-shaped nano-roughened portion 55 as the boundary, into one side LAH1 and the other side LAH2 in the width direction LAH of the nano-roughened portion 55, i.e., one side EH1 and the other side EH2 in the axial direction EH of the terminal member 50.

[0040] In the second metal-resin bonded body 200, the case lid member 30 has a through-hole 30h. An opening peripheral surface 30me of the metal surface 30m of the case lid member 30 is provided with a recessed portion 33 including a band-shaped nano-roughened portion 35 that surrounds the opening edge 30he, and a resin member 70 is bonded to the entire circumference of this band-shaped nano-roughened portion 35 that surrounds the opening edge 30he. Therefore, the opening peripheral surface 30me of the case lid member 30 and the resin member 70 can be airtightly separated, with the band-shaped nano-roughened portion 35 as the boundary, into one side LBH1 and the other side LBH2 in the width direction LBH of the nano-roughened portion 35, i.e., into an inner side FH1 and an outer side FH2 of the opening peripheral surface 30me.

[0041] Next, a method for manufacturing the battery 1, including a method for manufacturing the metal-resin bonded bodies 100, 200, will be described (see FIGS. 9 to 11). First, a pre-roughening case lid member (metal member) 30Z is prepared. The pre-roughening case lid member 30Z is obtained by pressing an aluminum plate. Also, a pre-roughening terminal member (metal member) 50Z is prepared. The pre-roughening terminal member 50Z is obtained by pressing a metal plate (an aluminum plate for the positive electrode and a copper plate for the negative electrode).

[0042] Then, in the "first recess formation step (hereinafter also simply referred to as the "recess formation step") S11" (see FIG. 9) of the "metal-resin bonded body manufacturing step S1," the resin bonded portion 51 on the outer peripheral surface 50mc of the metal surface 50m of the terminal member 50Z is intermittently irradiated with pulsed laser light LC while shifting the irradiation position, thereby forming a number of bowl-shaped recesses 57 and forming the recess arrangement portion 53 (see FIGS. 10 and 4). Note that in FIG. 4, the scanning direction of the pulsed laser light LC (the direction in which the irradiation position advances) is indicated by a dashed arrow.

[0043] Specifically, pulsed laser light LC is scanned around the entire circumference in the circumferential direction IAH in the connecting direction MAH (the battery width direction BH and the battery thickness direction CH when the battery 1 is assembled) that intersects (orthogonal in this embodiment) the width direction JAH of the resin joint 51, forming a rectangular ring-shaped concave portion connecting region 59 in which multiple bowl-shaped concave portions 57 are connected in a row in the connecting direction MAH while partially overlapping each other. Furthermore, the formation of these concave portion connecting regions 59 is repeated in multiple rows (10 rows in this embodiment) in the array placement direction NAH (the battery height direction AH when the battery 1 is assembled) that is orthogonal to the connecting direction MAH, forming a concave portion arrangement portion 53 that has a rectangular ring-shaped band shape with multiple rows of concave portion connecting regions 59 partially overlapping each other in the array placement direction NAH. The concave portion connecting regions 59 may be formed in a multiple-tiered spiral shape to form the concave portion arrangement portion 53.

[0044] Of the ten rows of connected recessed portion regions 59 that make up the recess arrangement section 53, the last-formed connected recessed portion region 59 (the connected recessed portion region 59 located on the lowest side AH2 when the battery 1 is assembled) has small, low nanopillars 58L, and therefore this last connected recessed portion region 59 becomes a non-nano-roughened portion 56. The dimension of the non-nano-roughened portion 56 in the width direction LAH is approximately 75 μm for the positive electrode terminal member 50 and approximately 60 μm for the negative electrode terminal member 50. On the other hand, in the remaining nine rows of connected recessed portions 59 (nine rows of connected recessed portions 59 on the upper side AH1 when the battery 1 is constructed), the forest of nanopillars 58 is large and forms tall nanopillars 58H, so that the nine rows of connected recessed portions 59 form a rectangular, annular nano-roughened portion 55. The dimension of the nano-roughened portion 55 in the width direction LAH is approximately 675 μm for the positive electrode terminal member 50 and approximately 540 μm for the negative electrode terminal member 50.

[0045] In this embodiment, the irradiation conditions of the positive electrode laser were set to 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. The irradiation conditions of the negative electrode laser were set to a wavelength of 1064 nm, a peak output of 20 kW, a pulse width of 50 ns, a pitch pb of 60 μm, and a spot diameter of 75 μm.

[0046] In the resin joint 51, in the circular area in plan view irradiated with the pulsed laser beam LC, the metals (aluminum for the positive electrode and copper for the negative electrode) near the surface melt and turn into vapor. Then, as the temperature of the vapor drops, they turn into particles 58p (aluminum and aluminum oxide particles 58p for the positive electrode, and copper and copper oxide particles 58p for the negative electrode) and accumulate in the resin joint 51. By intermittently irradiating the resin joint 51 with the pulsed laser beam LC while shifting the irradiation position, the particles 58p accumulate in a string-like pattern and combine to form columns, forming a forest of nanopillars 58. In the concave-connected region 59 that is formed last, it is thought that the height ha of the nanopillars 58 is low because there is little accumulation of particles 58p from the surrounding area.

[0047] Separately, in the "second recess formation process (hereinafter also simply referred to as the "recess formation process") S12" (see Figure 9) of the metal resin joint manufacturing process S1, pulsed laser light LC is intermittently irradiated to each of the resin joint portions 31 of a pair of opening peripheral surfaces 30me of the metal surface 30m of the above-mentioned case lid member 30Z while shifting the irradiation position, thereby forming a number of bowl-shaped recesses 37 and recess arrangement portions 33 (see Figures 10 and 4).

[0048] Specifically, the pulsed laser beam LC is scanned along the entire circumference of the resin joint 31 in the connecting direction MBH (the battery width direction BH and the battery thickness direction CH when the battery 1 is assembled) which intersects (orthogonal in this embodiment) the width direction JBH of the resin joint 31, forming a rectangular ring-shaped connected-recess region 39 in which multiple bowl-shaped recesses 37 are connected in a row in the connecting direction MBH while partially overlapping each other. Furthermore, the formation of these connected-recess regions 39 is repeated in multiple rows (five rows in this embodiment) in the row placement direction NBH (the radial direction of the through-hole 30h) which is orthogonal to the connecting direction MBH, forming a multi-tiered rectangular ring-shaped recess arrangement portion 33 with the five rows of connected-recess regions 39 partially overlapping each other in the row placement direction NBH. The connected-recess regions 39 may also be formed in a multiple-layered spiral shape to form the recess arrangement portion 33.

[0049] Of the five rows of connected recessed portion regions 39 that make up the recess arrangement section 33, the last connected recessed portion region 39 (the connected recessed portion region 39 located on the outermost radial side) has small nanopillars 38 standing tall, that is, low nanopillars 38L, and therefore this last connected recessed portion region 39 becomes a non-nano-roughened portion 36. The dimension of the non-nano-roughened portion 36 in the width direction LBH is approximately 75 μm. On the other hand, the remaining four rows of connected recessed portions 39 on the inside in the radial direction have large, forested nanopillars 38, forming tall nanopillars 38H, and therefore the four rows of connected recessed portions 39 form a rectangular, annular nano-roughened portion 35. The dimension of the nano-roughened portion 35 in the width direction LBH is approximately 300 μm. The laser irradiation conditions were the same as those used when irradiating the positive electrode terminal member 50 with a laser in the first recessed portion forming step S11.

[0050] Next, in the "resin forming step S13" (see FIG. 9) of the metal resin bonded body manufacturing process S1, resin members 70 are formed to be bonded to the terminal members 50 and the case lid member 30. In this embodiment, with the positive and negative terminal members 50 inserted into the through holes 30h of the case lid member 30, the pair of resin members 70 are insert-molded using the above-mentioned resin material 75 (see FIG. 11).

[0051] Specifically, the resin forming step S13 is performed using a molding die (not shown) having an upper die and a lower die. First, the case lid member 30 is placed at a predetermined position in the lower die, and then the positive and negative terminal members 50 are inserted into the pair of through holes 30h in the case lid member 30 (see FIG. 11(a)). After that, the upper die is moved toward the lower die to close the molding die. Next, molten resin material 75 is injected into each of the two cavities of the molding die. At this time, the resin material 75 is also filled between the tall nanopillars 58H that stand in the nano-roughened portion 55 of the terminal member 50 and between the tall nanopillars 38H that stand in the nano-roughened portion 35 of the case lid member 30.

[0052] Then, a resin member 70 is formed that is airtightly joined to the nano-roughened portion 55 of the terminal member 50 over the entire circumference in the circumferential direction IAH, and to the resin joint portion 51 over the entire circumference, and that is airtightly joined to the nano-roughened portion 35 of the case lid member 30 over the entire circumference in the circumferential direction IBH, and to the resin joint portion 31 over the entire circumference (see FIG. 11(b) and FIGS. 5 to 8). Thereafter, the lid assembly 15 in which the terminal member 50 is fixed to the case lid member 30 via the resin member 70 is removed from the molding die. In this way, a first metal-resin joined body 100 made of the terminal member 50 and the resin member 70, and a second metal-resin joined body 200 made of the case lid member 30 and the resin member 70 are formed.

[0053] Next, in the "electrode body connecting step S2" (see FIG. 9), an electrode body 40 is prepared by stacking a positive electrode plate 41, a negative electrode plate 42, and a separator 43, and the terminal extension portion 50b of the positive electrode terminal member 50 of the lid assembly 15 is welded to the positive electrode current collecting portion 40c of the electrode body 40 (see FIGS. 1 and 2). Also, the terminal extension portion 50b of the negative electrode terminal member 50 of the lid assembly 15 is welded to the negative electrode current collecting portion 40d of the electrode body 40. Thereafter, the electrode body 40 is wrapped in a bag-shaped insulating holder 7.

[0054] Next, in the "electrode assembly accommodating / case forming process S3," a case body member 20 is prepared, the electrode assembly 40 covered with the insulating holder 7 described above is inserted into the case body member 20, and the opening 20c of the case body member 20 is closed with the case lid member 30. The opening 20c of the case body member 20 and the peripheral edge portion 30f of the case lid member 30 are then laser-welded airtightly around the entire periphery to form the case 10 accommodating the electrode assembly 40 inside.

[0055] Next, in the "pouring and sealing step S4," the electrolyte 5 is poured into the case 10 through the pouring hole 30k, and the electrolyte 5 is impregnated into the electrode body 40. Thereafter, the pouring hole 30k is covered from the outside with a sealing member 12, and the sealing member 12 is laser-welded to the case 10 in an airtight manner. Next, in the "initial charging and aging step S5," a charging device (not shown) is connected to the battery 1, and the battery 1 is initially charged. 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.

[0056] In the manufacturing method of the metal-resin bonded body 100, 200 of this embodiment, in the recess forming steps S11, S12, a pulsed laser beam LC is scanned to form a plurality of recess-connected regions 59, 39 in the arrangement directions NAH, NBH, in which a plurality of bowl-shaped recesses 37, 57 are connected in a row in the connection directions MAH, MBH, and the recess arrangement portion 53, 33 including the nano-roughened portion 55, 35 is formed, so that the nano-roughened portion 55, 35 can be easily formed. Then, in the resin forming step S13, the resin member 70 is formed while filling the spaces between the tall nano-columns 58H, 38H that stand in the nano-roughened portion 55, 35 with a resin material 75, so that the resin member 70 that is airtightly bonded to the nano-roughened portion 55, 35 all around can be easily formed. Furthermore, in this embodiment, in the recess formation steps S11 and S12, the recess-connected regions 59 and 39 are formed in a multi-stage, annular shape to form the recess arrangement portions 53 and 33 including the nano-roughened portions 55 and 35, so that the annular nano-roughened portions 55 and 35 can be easily formed in the resin joint portions 51 and 31.

[0057] 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]

[0058] 1. Battery (energy storage device) 10 cases 30 Case cover material (metal material) 30h through hole 30he (through hole) opening edge 30m (metal surface of case cover) 30me (metal surface) opening periphery 31 Resin joint (on the metal surface of the case cover) 33 (Resin joint of case cover member) recessed portion arrangement portion 35 Nano-roughened portion (of recessed portion of case lid member) 36 Non-nano-roughened portion (of recessed portion of case lid member) 37 (Case lid member) bowl-shaped recess 38 Nano pillars (of case lid) 38H (Case lid material) High nano pillar 38L (Case lid material) low nano pillar 38p particles (derived from the case lid) 39 (Case cover member) Recessed portion 40 Electrode body 50 Terminal material (metal material) 50m (terminal material) metal surface 50mc (metal surface) outer circumference 51 Resin joint (on the metal surface of the terminal member) 53 (Resin joint of terminal member) recessed portion arrangement portion 55 Nano-roughened portion (of recessed portion of terminal member) 56 Non-nano-roughened portion (of recessed portion of terminal member) 57 (of terminal member) cup-shaped recess 58 Nanopillar (of terminal material) 58H (Terminal material) High nano pillar 58L (Terminal material) Low nano pillar 58p particles (derived from terminal material) 59 (Terminal member) Recessed portion 70 Resin parts 75 Resin material 100 First metal-resin bonded body (comprising a terminal member and a resin member) 200 Second metal-resin bonded body (comprising a case lid member and a resin member) IAH,IBH (Resin joint) circumferential direction LAH, LBH (nano-roughened area) width direction LAH1,LBH1 (widthwise) one side LAH2,LBH2 (other side in width direction) MAH, MBH connection direction NAH,NBH alignment direction ha (nanopillar) height Da (particle) diameter Db (bowl-shaped recess) diameter LC pulsed laser light S1 Metal-resin joint manufacturing process S11 First recess forming step S12: Second recess formation process S13 Resin forming process

Claims

1. a metal member having a band-shaped resin joint on a metal surface; a resin member joined to the resin joint portion over the entire circumference in the circumferential direction of the resin joint portion and fixed to the metal member; A metal-resin bonded body, The resin joint portion of the metal member is a recessed portion arrangement portion in which a number of bowl-shaped recessed portions each having a diameter of 30 to 300 μm are arranged in a line with some of the recessed portions overlapping each other, the recessed portion being an annular band extending over the entire circumference in the circumferential direction; The recessed portion is a nano-roughened portion having a ring-shaped configuration extending over the entire circumference in the circumferential direction, in which the nano-coars are formed by nano-columns formed by linking together in a string of beads particles each having a diameter of 100 nm or less derived from the metal constituting the metal member, and in which the bowl-shaped recesses are lined with rows of high nano-columns each having a height of 40 nm or more; a non-nano-roughened portion in which the bowl-shaped recesses are lined up, where the nanopillars are not present, or where the bowl-shaped recesses have a forest of low nanopillars with a height of less than 40 nm; The resin member is a resin material constituting the resin member is filled between the tall nano-pillars standing in the nano-roughened portion and bonded to the nano-roughened portion over the entire periphery, The space between the metal member and the resin member is airtightly sealed between one side and the other side of the nano-roughened portion in the width direction. Metal-resin joint.

2. The metal-resin bonded body according to claim 1, The metal member is The metal surface is a rod-shaped member having an outer circumferential surface, the recessed portion including the nano-roughened portion in a ring shape surrounding the outer circumferential surface, The resin member is an annular member surrounding the outer circumferential surface of the metal member, The nano-roughened portion is bonded to the annular nano-roughened portion over the entire circumference. Metal-resin joint.

3. The metal-resin bonded body according to claim 1, The metal member is A form having a through hole, the metal surface has an opening peripheral surface surrounding an opening edge of the through hole, the recess arrangement portion includes the nano-roughened portion having an annular shape surrounding the edge of the opening, on the peripheral surface of the opening; The resin member is The nano-roughened portion is bonded to the nano-roughened portion in a ring shape surrounding the edge of the opening. Metal-resin joint.

4. a metal member having a band-shaped resin joint on a metal surface; a resin member joined to the resin joint portion over the entire circumferential direction of the resin joint portion and fixed to the metal member, The resin joint portion of the metal member is a recessed portion arrangement portion in which a number of bowl-shaped recessed portions each having a diameter of 30 to 300 μm are arranged in a line with some of the recessed portions overlapping each other, the recessed portion being an annular band extending over the entire circumference in the circumferential direction; The recessed portion is a nano-roughened portion having a ring-shaped configuration extending over the entire circumference in the circumferential direction, in which the nano-coars are formed by nano-columns formed by linking together in a string of beads particles each having a diameter of 100 nm or less derived from the metal constituting the metal member, and in which the bowl-shaped recesses are lined with rows of high nano-columns each having a height of 40 nm or more; a non-nano-roughened portion in which the bowl-shaped recesses are lined up, where the nanopillars are not present, or where the bowl-shaped recesses have a forest of low nanopillars with a height of less than 40 nm; The resin member is a resin material constituting the resin member is filled between the tall nano-pillars standing in the nano-roughened portion and bonded to the nano-roughened portion over the entire periphery, The space between the metal member and the resin member is airtightly sealed between one side and the other side of the nano-roughened portion in the width direction. A method for producing a metal-resin bonded body, comprising: a recess forming step of intermittently irradiating the resin joint portion of the metal member with pulsed laser light while shifting the irradiation position to form a large number of the bowl-shaped recesses and form the recess arrangement portion; a resin forming step of forming the resin member bonded to the metal member after the recess forming step, The recess forming step includes: scanning the pulsed laser light in a connecting direction intersecting with a width direction of the resin joint portion to form a concave portion connecting region in which the plurality of bowl-shaped concave portions are connected in a row in the connecting direction while partially overlapping each other; Repeatedly arranged in a plurality of rows in a row arrangement direction perpendicular to the direction of the rows, a plurality of rows of the recessed portion-connected regions are arranged so as to overlap each other in the row arrangement direction, thereby forming the recessed portion arrangement portion including the nano-roughened portion; The resin forming step includes: The resin material is filled between the high nano-columns that stand in the nano-roughened portion, and the resin member is airtightly bonded to the nano-roughened portion over the entire periphery and bonded to the resin bonded portion over the entire periphery. Method for manufacturing a metal-resin bonded body.

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