Metal-resin joint and method of manufacturing metal-resin joint

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 to a method for producing the metal-resin bonded body. [Background technology]

[0002] As a metal-resin joined body in which a resin member is joined and fixed to a metal member, a metal-resin joined body is known that includes a metal member having a band-shaped (band-shaped and ring-shaped) resin joint on the metal surface, and a resin member joined to the resin joint over the entire circumference in the circumferential direction and fixed to the metal member. Such a metal-resin joined body is included in an electric storage device such as a battery. 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, and the resin member is airtightly joined to the case lid member and the terminal members while insulating them from each other, thereby fixing the terminal members to the case lid member. In such a battery, the terminal members (metal members) and the resin members joined and fixed thereto correspond to the above-mentioned "metal-resin joined body". In addition, the case lid member (metal members) and the resin members joined and fixed thereto also correspond to the "metal-resin joined body". The above-mentioned battery is disclosed in, for example, Patent Document 1 (see FIGS. 1, 2, etc.). [Prior art documents] [Patent documents]

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

[0004] As a method for roughening the surface of the resin joint of the metal members, it is possible to intermittently irradiate the resin joint of 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 recesses are formed in the resin joint by irradiating the resin joint with pulsed laser light, and a recess arrangement portion is formed, and nano-level nano-columns are formed on the surface of the bowl-shaped recesses, in which particles derived from the metal constituting the metal member are linked together in a string-like manner to form a columnar shape. It is believed that by forming the recess arrangement portion in the resin joint of the metal members in this way, the metal member and the resin member can be firmly joined with high airtightness.

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

[0006] Furthermore, since the resin member cannot be firmly and airtightly bonded to the metal member in the non-nano-roughened portion, 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 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, or conversely, the electrolyte contained inside the battery may leak out to the outside 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 joined body in which a resin member is joined and fixed to a metal member, which can improve the sealing property between the metal member and the resin member, and a method for manufacturing the metal-resin joined body. [Means for solving the problem]

[0008] (1) One aspect of the present invention for solving the above problem is a metal resin joined body including a metal member having a band-shaped resin joint portion on a metal surface, and a resin member joined to the resin joint portion over an entire circumference in a circumferential direction and fixed to the metal member, wherein the resin joint portion of the metal member has a band-shaped ring-shaped portion over the entire circumference in the circumferential direction and a recessed portion arranged 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 each other, and the recessed portion has a band-shaped ring-shaped portion over the entire circumference in the circumferential direction and a diameter of 100 nm or less derived from a metal constituting the metal member. The nanopillars are formed by linking particles of the metal or alloy together in a string-like pattern, and include a nano-roughened section in which high nanopillars with a height of 40 nm or more are standing in a forest, and a non-nano-roughened section in which there are no nanopillars or the standing nanopillars are low nanopillars with a height of less than 40 nm.The resin member is bonded to the nano-roughened section all around, with a resin material constituting the resin member filled between the high nanopillars standing in the nano-roughened section, and the space between the metal member and the resin member between one side and the other side in the width direction of the nano-roughened section is airtightly sealed.

[0009] In the above-mentioned metal-resin bonded body, a band-shaped (band-shaped and ring-shaped) recess arrangement portion in which a large number of cup-shaped recesses are arranged is provided in a band-shaped resin bonding portion of the metal surface of the metal member. This recess arrangement portion includes a non-nano-roughened portion in which there are no nano-pillars or in which low nano-pillars stand (not appropriately nano-roughened at the nano-level), but includes a nano-roughened portion in which a region in which high nano-pillars stand (appropriately nano-roughened at the nano-level) is formed into a band-shaped ring. The resin member is bonded to the nano-roughened portion over its entire circumference by filling the spaces between the high nano-pillars standing in the nano-roughened portion with a resin material, 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. Therefore, in the above-mentioned metal-resin bonded body, the sealing property between the metal member and the resin member can be improved despite the presence of a non-nano-roughened portion that is not appropriately nano-roughened in the recess arrangement portion.

[0010] The "recessed portion" may be a partial region of the resin joint, or the entire region of the resin joint. The "annular nano-roughened portion" preferably has a width of at least 150 μm, which makes it possible to more effectively hermetically seal the gap between one side and the other side of the nano-roughened portion in the width direction. The "metal member" is preferably composed mainly of any one of aluminum, copper, iron, tin, titanium, zinc, chromium, and nickel. This makes it possible to easily provide a recess arrangement portion in which a large number of cup-shaped recesses are 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, the metal surface having the recessed portion including the nano-roughened portion in a ring shape surrounding the outer peripheral surface, and the resin member may be an annular member surrounding the outer peripheral surface of the metal member, and may be bonded to the nano-roughened portion in a ring shape around the entire circumference of the metal-resin bonded body.

[0012] In the above-mentioned metal-resin bonded body, the metal member is rod-shaped, and the resin member is annular and surrounds the outer circumferential 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 circumferential surface, and the resin member is bonded to the entire periphery of the band-shaped nano-roughened portion. Therefore, the outer circumferential surface of the metal member and the resin member can be airtightly separated into one side and the other side in the width direction of the nano-roughened portion, i.e., one side and the other side 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 nano-roughened portion having a ring-shaped shape surrounding the opening edge, and the resin member is bonded to the nano-roughened portion having a ring-shaped shape surrounding the opening edge around the entire circumference.

[0014] In the above-mentioned metal-resin bonded body, the metal member has a through hole. A recessed portion including a ring-shaped nano-roughened portion surrounding the edge of the opening is provided on the metal surface of the metal member, and the resin member is bonded to the entire circumference of the ring-shaped nano-roughened portion surrounding the edge of the opening. Therefore, the opening peripheral surface of the metal member and the resin member can be airtightly separated into one side and the other side in the width direction of the nano-roughened portion, i.e., the inside and outside of the opening peripheral surface, by the ring-shaped nano-roughened portion.

[0015] (4) Still another aspect is a metal member having a band-shaped resin bonding portion on a metal surface, and a resin member bonded to the resin bonding portion over the entire circumference in the circumferential direction and fixed to the metal member, wherein the resin bonding portion of the metal member has a band-shaped recessed portion over the entire circumference in the circumferential direction, and a recessed portion in which a number of cup-shaped recessed portions having a diameter of 30 to 300 μm are arranged in a row with some overlapping, and the recessed portion is a band-shaped recessed portion over the entire circumference in the circumferential direction, and particles having a diameter of 100 nm or less derived from the metal constituting the metal member are included. The nano-pillars are linked together in a daisy-chain shape to form a pillar, and the nano-coarse portion includes a forest of high nano-pillars with a height of 40 nm or more, and a non-nano-roughened portion where there are no nano-pillars or the forest of low nano-pillars has a height of less than 40 nm. The resin member is bonded to the nano-roughened portion all around by filling the spaces between the high nano-pillars that forest the nano-roughened portion with a resin material constituting the resin member, and the space between the high nano-pillars that forest the nano-roughened portion is airtight between the metal member and the resin member, and the space between one side and the other side in the width direction of the nano-roughened portion is airtight. A method for producing a metal-resin bonded body tightly sealed, the method comprising: a recess forming step of intermittently irradiating the resin bonded portion of the metal member with a pulsed laser beam while shifting an irradiation position to form a large number of the bowl-shaped recesses and form the recess arrangement portion; and a resin forming step of forming the resin member bonded to the metal member after the recess forming step, the recess forming step being performed by scanning the pulsed laser beam in a continuous direction intersecting a width direction of the resin bonded portion, so that the plurality of the bowl-shaped recesses are arranged in a front-to-back manner while partially overlapping each other. This method for manufacturing a metal-resin joint includes forming a row of recess-connected regions in the connecting direction, and repeating this process in multiple rows in an arrangement direction perpendicular to the connecting direction, arranging the multiple rows of recess-connected regions while partially overlapping them in the arrangement direction to form the recess arrangement portion including the nano-roughened portion, and the resin formation process fills the spaces between the high nano-columns standing in the nano-roughened portion with the resin material, while airtightly joining the nano-roughened portion around its entire circumference and forming the resin member joined to the resin joint portion around its entire circumference.

[0016] In the above-mentioned method for manufacturing a metal-resin bonded body, in the recess forming step, a pulsed laser beam is scanned to form a plurality of recess-connected regions in the arrangement direction, in which a plurality of cup-shaped recesses are arranged in a row in the connection direction, and a recess arrangement portion including a nano-roughened portion is formed, so that the nano-roughened portion can be easily formed. In the resin forming step, a resin member is formed while filling the spaces between the tall nano-columns standing in the nano-roughened portion with a resin material, so that a resin member that is airtightly bonded to the nano-roughened portion all around can be easily formed.

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

[0018] (5) In the method for producing a metal-resin bonded body described in (4), the recess forming 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 shape, or in a multi-layered spiral or vortex shape, to form the recess arrangement portion including the nano-roughened portion.

[0019] In the above-mentioned 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 shape or a multi-layered spiral or vortex 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 description 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. [Diagram 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 joined body and a second metal resin joined body according to an embodiment of the present invention. [Diagram 3]3 is a partially enlarged cross-sectional view along the battery height direction and the battery thickness direction in the vicinity of a resin member in a battery having a first metal resin joined body and a second metal resin joined body according to an embodiment. 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. [Diagram 5] FIG. 4 is a partially enlarged cross-sectional view of a nano-roughened portion in the embodiment. [Figure 6] FIG. 2 is a partially enlarged cross-sectional view showing tall nano-pillars standing in a cup-shaped recess in the nano-roughened portion according to the embodiment. [Figure 7] FIG. 4 is a partially enlarged cross-sectional view of a non-nano-roughened portion in the embodiment. [Figure 8] FIG. 11 is a partially enlarged cross-sectional view showing small nano-pillars standing in a cup-shaped recess in a non-nano-roughened portion according to an embodiment. [Figure 9] 2 is a flowchart of a method for producing a battery including a method for producing a metal resin bonded body according to an embodiment. [Figure 10] FIG. 11 is an explanatory view showing how a plurality of cup-shaped recesses are formed by scanning with a pulsed laser beam in a first recess-forming step (second recess-forming step) in the method for producing a metal-resin bonded body according to the embodiment. [Figure 11] 1A and 1B are explanatory diagrams of a resin forming step in a manufacturing method of a metal resin bonded body according to an embodiment, in which (a) shows a state in which positive and negative terminal members are inserted into the through holes of a case lid member, and (b) is an explanatory diagram showing a state in which a pair of resin members are molded. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[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 a partially enlarged 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 square (rectangular) sealed lithium ion secondary battery that is mounted on vehicles such as hybrid cars, plug-in hybrid cars, and electric cars. The battery 1 is composed of a case 10 made of a case body member 20 and a case lid member 30, an electrode body 40 housed in the case 10, and positive and negative terminal members 50 fixed to the case 10 via a resin member 70. The electrode body 40 is covered in the case 10 by a bag-shaped insulating holder 7 made of an insulating film. An electrolyte 5 is also housed in the case 10, a part of which is impregnated in the electrode body 40 and the remainder is pooled on the bottom wall of the case 10.

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

[0024] The case 10 is a rectangular box made of metal (aluminum in this embodiment), and is a bottomed square cylinder having a rectangular opening 20c. The case 10 is composed of a case body member 20 that houses the electrode body 40 inside, and a rectangular plate-shaped case lid member 30 that closes the opening 20c of the case body member 20. The opening 20c of the case body member 20 and the peripheral portion 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 breaks and opens when the internal pressure of the case 10 exceeds the valve opening pressure. The case lid member 30 is also provided with a liquid injection hole 30k, which is hermetically sealed with a disk-shaped sealing member 12 made of aluminum.

[0025] The electrode body 40 is a rectangular parallelepiped laminated type, in which a plurality of rectangular positive electrode plates 41 and a plurality of rectangular negative electrode plates 42 are alternately laminated in the battery thickness direction CH via rectangular separators 43 made of a resin porous film. On one side BH1 of the electrode body 40 in the battery width direction BH, the current collector foils of the positive electrode plates 41 overlap in the battery thickness direction CH to form a positive electrode current collector 40c. This positive electrode current collector 40c is conductively connected to a positive electrode terminal member 50 described later. On the other side BH2 of the electrode body 40 in the battery width direction BH, the current collector foils of the negative electrode plates 42 overlap in the battery thickness direction CH to form a negative electrode current collector 40d. This negative electrode current collector 40d is conductively connected to a negative electrode terminal member 50 described later.

[0026] The case lid member 30 has rectangular through-holes 30h near the ends of one side BH1 and the other side BH2 in the battery width direction BH, respectively. 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 in a state 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 in a state insulated from the case lid member 30 via the resin member 70.

[0027] The terminal member 50 is a metal plate (aluminum plate for the positive electrode, copper plate for the negative electrode) pressed to have 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 located on one side EH1 of the axial direction EH (a side AH1 above the case lid member 30 in the battery height direction AH) and is composed of a rectangular plate-shaped terminal top plate portion 50a 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 of 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 one side CH1 of the battery thickness direction CH and extends to the lower side AH2, passes through the through hole 30h of the case lid member 30, and further extends through the resin member 70 to the lower side 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 conductively 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 conductively connected to the negative electrode current collector 40d.

[0028] Of the metal surface 50m of the terminal member 50, a band-shaped portion to which the resin member 70 is bonded is the resin joint portion 51, and a 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 of the outer peripheral surface 50mc of the terminal extension portion 50b, a portion 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 of the outer peripheral surface 50mc of the terminal extension portion 50b, a portion protruding and 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). Fig. 4 shows an enlarged view of the A portion of the resin joint portion 51 surrounded by a dashed line in Fig. 3. The resin joint portion 51 of the terminal member 50 is composed of a recessed portion 53 in which a large number of bowl-shaped recesses 57 are arranged, and a non-recessed portion 54 in which the bowl-shaped recesses 57 are not arranged. Specifically, the recessed portion 53 is a rectangular band-shaped annular portion of the resin joint portion 51 that surrounds the outer circumferential surface 50mc and is composed of the central portion in the battery height direction AH of the terminal extension portion 50b located inside the resin member 70. On the other hand, the non-recessed portion 54 is composed of a portion of the resin joint portion 51 that is composed of the terminal top plate portion 50a and the upper side AH1 and the 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 ring extending in the battery height direction AH around the entire circumference in the 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 overlapping each other.

[0031] Further, 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 shape extending in the battery height direction AH, a rectangular band-like portion forming an end portion on the lower side AH2 is the non-nano-roughened portion 56, and a rectangular band-like portion forming a portion on the upper side AH1 is the nano-roughened portion 55. The nano-roughened portion 55 is a columnar nano-pillar 58 formed by linking together particles 58p derived from the metal constituting the terminal member 50 in a string-like fashion, and is composed of tall nano-pillars 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 nano-pillars 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 nano-pillars 58 are made of particles 58p made of copper and copper oxide. The positive electrode 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 having 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 31 of the case lid member 30 will be described (see Figs. 3 to 8). Fig. 4 shows an enlarged view of the B portion of the resin joint 31 surrounded by a dashed line in Fig. 3. The annular portions of the metal surface 30m of the case lid member 30 to which the resin members 70 are joined are the resin joints 31, and the non-resin joints 32 are the portions to which the resin members 70 are not joined. 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 the upper side AH1, and the other opening edge 30he and opening peripheral surface 30me located on the lower side AH2. Of the metal surface 30m of the case lid member 30, a pair of opening peripheral surfaces 30me and an inner peripheral surface of a through hole 30h connecting them form a resin joint 31. On the other hand, of the metal surface 30m of the case lid member 30, a portion other than the opening peripheral surfaces 30me and the inner peripheral surface of the through hole 30h forms a non-resin joint 32.

[0033] The resin joint portion 31 of the case lid member 30 includes a recessed portion 33 in which a number of bowl-shaped recesses 37 are arranged, and a non-recessed portion 34 in which the bowl-shaped recesses 37 are not arranged. Specifically, in the resin joint portion 31, the radial center portions of the pair of opening peripheral surfaces 30me are the recessed portion 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-recessed portion 34. Each recessed portion 33 is a rectangular band annular shape that extends in the battery width direction BH and the battery thickness direction CH around the entire circumference of the resin joint portion 31 in the circumferential direction IBH (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 overlapping each other.

[0034] Further, each recess arrangement portion 33 is composed of a nano-roughened portion 35 and a non-nano-roughened portion 36. Specifically, in the recess arrangement portion 33, the rectangular band-shaped portion forming the periphery of the outer FH2 is the non-nano-roughened portion 36, and the rectangular band-shaped portion forming the inner FH1 portion is the nano-roughened portion 35. The nano-roughened portion 35 is a columnar nano-pillar 38 formed by linking together particles 38p derived from the metal constituting the case lid member 30, and is composed of tall nano-pillars 38H with heights 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 of particles 38p made of aluminum and aluminum oxide and with diameters 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 having a height ha of less than 40 nm (in this embodiment, the height ha = less than 20 nm) (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 member 50 while insulating the case lid member 30 and the terminal member 50 from each other.

[0036] In the first metal-resin bonded body 100 composed of 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, and is bonded to the band-shaped resin bonding portion 51 of the outer peripheral surface 50mc over the entire circumference in the circumferential direction IAH, and is fixed to the terminal member 50. In detail, the resin member 70 is bonded to the band-shaped nano-roughened portion 55 over the entire circumference in the circumferential direction IAH by filling the above-mentioned resin material 75 between the high nano-columns 58H standing in the nano-roughened portion 55 of the recessed portion arrangement portion 53 in the resin bonding portion 51. As a result, between the terminal member 50 and the resin member 70, 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 are airtightly sealed.

[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 of 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. In detail, the resin bonding portion 31 of the case lid member 30 has a pair of band-shaped recessed arrangement portions 33 surrounding the opening edges 30he of the upper side AH1 and the lower side AH2 of the through-hole 30h, as described above. The resin member 70 is bonded to the pair of nano-roughened portions 35 over the entire circumference in the circumferential direction IBH by filling the above-mentioned resin material 75 between the high nano-columns 38H standing in the nano-roughened portion 35 among these recessed arrangement portions 33. 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 body 100, 200 of this embodiment, a band-shaped recessed portion arrangement portion 53, 33 in which a large number of cup-shaped recessed portions 57, 37 are arranged is provided in a band-shaped resin bonding portion 51, 31 of the metal surface 50m, 30m of the metal member (terminal member 50 and case lid member 30). The recessed portion arrangement portion 53, 33 includes a non-nano-roughened portion 56, 36 in which low nano-pillars 58L, 38L stand in a forest (not properly nano-roughened), but also includes a nano-roughened portion 55, 35 in which a region in which high nano-pillars 58H, 38H stand in a forest (properly nano-roughened) has formed a band-shaped ring. The resin member 70 is joined to the nano-roughened portion 55, 35 over its entire circumference by filling the spaces between the high nano-columns 58H, 38H that stand in the nano-roughened portion 55, 35 with a resin material 75, and the spaces between the terminal member 50 and the case lid member 30 and the resin member 70, between one side LAH1, LBH1 and the other side LAH2, LBH2 in the width direction LAH, LBH of the nano-roughened portion 55, 35, are airtightly sealed. Therefore, in the metal-resin joined bodies 100, 200, the terminal member 50 and the case lid member 30 can each have good sealing properties with 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 circumferential 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 circumferential surface 50mc, and the resin member 70 is joined to the entire periphery of the band-shaped nano-roughened portion 55. For this reason, the outer circumferential 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 a boundary, into one side LAH1 and the other side LAH2 in the width direction LAH of the nano-roughened portion 55, i.e., into 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. The 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 surrounding the opening edge 30he, and the resin member 70 is bonded to the entire circumference of the band-shaped nano-roughened portion 35 surrounding 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 by the band-shaped nano-roughened portion 35 into one side LBH1 and the other side LBH2 in the width direction LBH of the nano-roughened portion 35, that is, into the inner side FH1 and the 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, an unroughened case lid member (metal member) 30Z is prepared. The unroughened case lid member 30Z is obtained by pressing an aluminum plate. Also, an unroughened terminal member (metal member) 50Z is prepared. The unroughened terminal member 50Z is obtained by pressing a metal plate (the positive electrode is an aluminum plate, and the negative electrode is a copper plate).

[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 circumferential surface 50mc of the metal surface 50m of the above-mentioned terminal member 50Z is intermittently irradiated with pulsed laser light LC while shifting the irradiation position, thereby forming a number of cup-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, the pulsed laser light LC is scanned over the entire circumference of 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 constructed) intersecting (orthogonal in this embodiment) the width direction JAH of the resin joint portion 51, to form a rectangular ring-shaped recess connecting region 59 in which a plurality of cup-shaped recesses 57 are connected in a row in the connecting direction MAH while partially overlapping each other. Furthermore, the formation of the recess connecting region 59 is repeated in a plurality of rows (10 rows in this embodiment) in the row placement direction NAH (the battery height direction AH when the battery 1 is constructed) perpendicular to the connecting direction MAH, and the 10 rows of recess connecting regions 59 are partially overlapped in the row placement direction NAH to form the recess arrangement portion 53 having a rectangular band ring shape in multiple stages. The recess connecting region 59 may be formed in a multiple-layered spiral shape to form the recess arrangement portion 53.

[0044] Of the ten rows of connected recessed portions 59 constituting the recess arrangement section 53, the last-formed connected recessed portion region 59 (the connected recessed portion region 59 located on the lowermost side AH2 when the battery 1 is constructed) has small nanopillars 58 standing side by side, that is, 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 terminal member 50 of the positive electrode and approximately 60 μm for the terminal member 50 of the negative electrode. 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 band-shaped annular nano-roughened portion 55. The dimension of the nano-roughened portion 55 in the width direction LAH is approximately 675 μm for the terminal member 50 of the positive electrode and approximately 540 μm for the terminal member 50 of the negative electrode.

[0045] In this embodiment, the irradiation conditions of the positive electrode laser are wavelength 1064 nm, peak power 5 kW, pulse width 150 ns, pitch pb 75 μm, and spot diameter 80 μm. The irradiation conditions of the negative electrode laser are wavelength 1064 nm, peak power 20 kW, pulse width 50 ns, pitch pb 60 μm, and spot diameter 75 μm.

[0046] In the resin joint 51, in the circular area in plan view irradiated with the pulsed laser light LC, the metals (aluminum for the positive electrode, copper for the negative electrode) near the surface melt and turn into steam. Thereafter, when the temperature of the steam drops, the metals 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 light LC while shifting the irradiation position, the particles 58p accumulate in a string of beads and combine to form columns, forming a forest of nanopillars 58. In the concave-connected region 59 formed last, it is considered that the height ha of the nanopillars 58 is low because there is little accumulation of particles 58p from the surroundings.

[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, 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 are intermittently irradiated with pulsed laser light LC while shifting the irradiation position, to form a number of cup-shaped recesses 37 and recess arrangement portions 33 (see Figures 10 and 4).

[0048] Specifically, the pulsed laser light LC is scanned over the entire circumference in the circumferential direction IBH in the connecting direction MBH (the battery width direction BH and the battery thickness direction CH when the battery 1 is constructed) intersecting (perpendicular in this embodiment) the width direction JBH of the resin joint portion 31, to form a rectangular ring-shaped concave connecting region 39 in which a plurality of cup-shaped concaves 37 are connected in a row in the connecting direction MBH while partially overlapping each other. Furthermore, the formation of the concave connecting region 39 is repeated in a plurality of rows (five rows in this embodiment) in the row arrangement direction NBH (the radial direction of the through hole 30h) perpendicular to the connecting direction MBH, and the five rows of concave connecting regions 39 are partially overlapped in the row arrangement direction NBH to form the concave arrangement portion 33 having a rectangular band ring shape in multiple stages. The concave connecting region 39 may be formed in a multiple-layered spiral shape to form the concave arrangement portion 33.

[0049] Of the five rows of connected recessed portions 39 constituting 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 in a row, 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, in the remaining four rows of connected recessed portions 39 on the inner side in the radial direction, the forest of nanopillars 38 is large and has high nanopillars 38H, so that the four rows of connected recessed portions 39 form a rectangular band-shaped 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 when the positive electrode terminal member 50 was irradiated with a laser in the first recessed portion forming step S11.

[0050] Next, in a "resin formation step S13" (see FIG. 9) of the metal resin bonded body manufacturing process S1, a resin member 70 is 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 respectively 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 the positive and negative terminal members 50 are inserted into the pair of through holes 30h of the case lid member 30, respectively (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 that time, the resin material 75 is also filled between the tall nano pillars 58H standing in a forest in the nano-roughened portion 55 of the terminal member 50, and between the tall nano pillars 38H standing in a forest in the nano-roughened portion 35 of the case lid member 30.

[0052] Then, the resin member 70 is formed, which is airtightly joined to the nano-roughened portion 55 of the terminal member 50 over the entire circumference in the circumferential direction IAH, and is airtightly joined to the resin joint portion 51 over the entire circumference, and 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 is joined 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 terminal member 50 of the lid assembly 15 described above 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 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. Then, the opening 20c of the case body member 20 and the peripheral portion 30f of the case lid member 30 are laser-welded airtightly all around to form the case 10 accommodating the electrode assembly 40 therein.

[0055] Next, in a "pouring and sealing process S4", electrolyte 5 is poured into case 10 through pouring hole 30k, and electrolyte 5 is impregnated into electrode body 40. Thereafter, pouring hole 30k is covered from the outside with sealing member 12, and sealing member 12 is laser-welded to case 10 airtightly. Next, in the "initial charging and aging step S5", a charging device (not shown) is connected to the battery 1 to perform an initial charge on the battery 1. After that, the initially charged battery 1 is left to stand for a predetermined time to age the battery 1. In this way, the battery 1 is completed.

[0056] In the manufacturing method of the metal-resin bonded body 100, 200 of this embodiment, in the recess forming steps S11, S12, the pulsed laser light LC is scanned to form a plurality of recess-connected regions 59, 39 in which a plurality of cup-shaped recesses 37, 57 are connected in a row in the connection directions MAH, MBH, in the arrangement directions NAH, NBH, 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 high nano-columns 58H, 38H standing in the nano-roughened portion 55, 35 with the resin material 75, so that the resin member 70 that is airtightly connected to the nano-roughened portion 55, 35 over its entire circumference can be easily formed. Furthermore, in this embodiment, in the recess formation steps S11 and S12, the recess-connected regions 59, 39 are formed in a multi-stage, ring-shaped shape to form the recess arrangement portions 53, 33 including the nano-roughened portions 55, 35, so that the ring-shaped nano-roughened portions 55, 35 can be easily formed in the resin bonding portions 51, 31.

[0057] Although the present invention has been described above with reference to an embodiment, it goes without saying that the present invention is not limited to the embodiment and can be modified as appropriate without departing from the spirit of the present invention. [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 metal surface of case cover material) 33 (Resin joint of case cover member) recessed portion 35 Nano-roughened portion (of recessed portion of case lid member) 36 (Non-nano roughened portion of the recessed portion of the case lid member) 37 (Case cover part) cup-shaped recess 38 Nano pillars (of case cover material) 38H (Case cover material) High nano pillar 38L (Case lid material) low nano pillar 38p (from the case lid) particles 39 (Case cover member) recessed portion connecting area 40 Electrode body 50 Terminal parts (metal parts) 50m (Terminal material) Metal surface 50mc (metal surface) outer circumference 51 Resin joint (of metal surface of terminal member) 53 (Resin joint of terminal member) recessed 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 Nano pillars (of terminal parts) 58H (Terminal material) High nano pillar 58L (Terminal material) Low nano pillar 58p (derived from terminal material) particles 59 (Terminal member) Recessed area 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 part) width direction LAH1,LBH1 (widthwise) one side LAH2,LBH2 (other side in width direction) MAH, MBH connection direction NAH,NBH alignment direction ha (height of nano pillar) Da (diameter of particle) Db (Bowl) Diameter LC Pulsed Laser Light S1 Metal-resin joint manufacturing process S11: First recess forming step S12: Second recess forming step 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 an entire circumference in a 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 recess arrangement portion having a plurality of bowl-shaped recesses, each having a diameter of 30 to 300 μm, arranged in a partially overlapping manner in a band-like annular shape extending over the entire circumference in the circumferential direction; The recessed portion is a nano-roughened portion in which nano-columns are formed by linking together particles having a diameter of 100 nm or less derived from a metal constituting the metal member in a string-like manner, the nano-columns being 40 nm or more in height, the nano-columns being in a band-like shape extending around the entire circumference in the circumferential direction; a non-nano-roughened portion in which the nanopillars are not present or the nanopillars standing in a forest have a height of less than 40 nm; The resin member is a resin material constituting the resin member is filled between the high nano-pillars standing in the nano-roughened portion and bonded to the nano-roughened portion over an entire periphery thereof; Between the metal member and the resin member, one side and the other side in the width direction of the nano-roughened portion are airtightly sealed. 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 includes the nano-roughened portion having 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 The shape has 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 opening edge over the entire circumference of the nano-roughened portion. 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 an entire circumference in a circumferential direction of the resin joint portion and fixed to the metal member; The resin joint portion of the metal member is a recess arrangement portion having a plurality of bowl-shaped recesses, each having a diameter of 30 to 300 μm, arranged in a partially overlapping manner in a band-like annular shape extending over the entire circumference in the circumferential direction; The recessed portion is a nano-roughened portion in which nano-columns are formed by linking together particles having a diameter of 100 nm or less derived from a metal constituting the metal member in a string-like manner, the nano-columns being 40 nm or more in height, the nano-columns being in a band-like shape extending around the entire circumference in the circumferential direction; a non-nano-roughened portion in which the nanopillars are not present or the nanopillars standing in a forest have a height of less than 40 nm; The resin member is a resin material constituting the resin member is filled between the high nano-pillars standing in the nano-roughened portion and bonded to the nano-roughened portion over an entire periphery thereof; Between the metal member and the resin member, one side and the other side in the width direction of the nano-roughened portion are airtightly sealed. A method for producing a metal-resin bonded body, comprising the steps of: a recess forming step of intermittently irradiating the resin joint portion of the metal member with pulsed laser light while shifting an irradiation position to form a large number of the cup-shaped recesses and form the recess arrangement portion; a resin forming step of forming the resin member joined to the metal member after the recess forming step, The recess forming step includes: scanning the pulsed laser light in a connecting direction intersecting a width direction of the resin joint portion to form a recess connecting region in which the plurality of cup-shaped recesses are connected in a row in the connecting direction while partially overlapping each other; Repeated in a plurality of rows in a row arrangement direction perpendicular to the row arrangement direction, forming the recess arrangement portion including the nano-roughened portion by arranging the plurality of rows of the recess-connected regions in the row arrangement direction so as to overlap each other; The resin forming step includes: The resin material is filled between the high nano-columns that stand in a forest on the nano-roughened portion, and the resin member is airtightly bonded to the nano-roughened portion over the entire circumference and bonded to the resin bonding portion over the entire circumference. A method for producing a metal-resin bonded body.

Images