Battery and method for manufacturing the battery

Abstract

To provide an aluminum member excellent in bonding strength, an aluminum resin composite, and a method for manufacturing the aluminum resin composite.SOLUTION: Projection parts (a lid upper surface projection part layer F11, a lid lower surface projection part layer F21, a terminal side projection part layer F31 and a terminal lower surface projection part layer F41) having a diameter and height of less than 1 μm in nano order are densely arranged on the surface of a member body (a lid member 30 and a positive electrode terminal member 50) made of metal aluminum. Base ends connected to a member surface in the projection parts include amorphous alumina and α-alumina .SELECTED DRAWING: Figure 14

Description

[Technical Field]

[0001] The technical field disclosed in this specification is battery and battery This relates to a method for producing the above. [Background technology]

[0002] Aluminum resin composites in which an aluminum member and a resin member are bonded together are known. In order to increase the bonding strength between the aluminum member and the resin member, the surface of the aluminum member is subjected to a roughening treatment in advance. Patent Document 1, for example, is an example of related prior art.

[0003] In Patent Document 1, in order to obtain an aluminum resin composite, first, an aluminum member is immersed in an etching agent. Pickles As a result of the roughening treatment, a fine uneven shape is formed on the surface of the aluminum member. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2018-164989 Summary of the Invention [Problem to be solved by the invention]

[0005] By the way, when a conventional aluminum resin composite is immersed in a non-aqueous electrolyte solution containing lithium hexafluorophosphate and water, Pickles As a result, the resin member may separate from the aluminum member. The reason for this is explained below. Generally, a very thin oxide film is formed on the surface of an aluminum member. Therefore, in an aluminum resin composite, the resin member is bonded to the aluminum member via this oxide film. Hydrogen fluoride is generated in the liquid. Therefore, when an aluminum resin composite is immersed in the liquid, Pickles The oxide film is then decomposed by the hydrogen fluoride in the solution, resulting in the resin component being separated from the aluminum component. Pickles Similarly, in this case, the oxide film is decomposed by the hydrogen chloride in the liquid, and the resin member is separated from the aluminum member.

[0006] As described above, it is believed that conventional aluminum-resin composites do not have high acid resistance or hydrofluoric acid resistance. In other words, when an aluminum member is joined to a resin member, the joint strength of the joint is insufficient. Therefore, it has been desired to further improve the joint strength of the joint.

[0007] The present invention has been made in view of the above circumstances, and its object is to provide a method for bonding a resin member to a metal member. Connection Excellent joint strength at joints battery and battery The object of the present invention is to provide a method for producing the above-mentioned compound. [Means for solving the problem]

[0008] This was done to solve the above-mentioned problems. battery is made of metal aluminum Department Nano-order protrusions with a diameter and height of less than 1 μm on the surface of the material have , The protrusions are arranged such that adjacent ones in a planar view are spaced apart from each other at a distance at least equal to or less than the overall average value of the diameters of the protrusions, Among the protrusions, those connected to the surface of the member and the height of the protrusion is within a range of 20 nm from the base of the protrusion. The base end contains amorphous alumina and α-alumina. The base end of the protrusion contains more α-alumina than amorphous alumina. Aluminum components and an aluminum resin composite having a resin member bonded to the aluminum member, and a non-aqueous electrolyte solution containing lithium hexafluorophosphate. . Furthermore, in this battery, it is preferable that the average height of the protrusions is 84 to 1000 nm.

[0009] The aluminum member of the present invention A battery comprising an aluminum resin composite to which a resin member is bonded and a non-aqueous electrolyte containing lithium hexafluorophosphate.According to the results, nano-order protrusions with diameters and heights of less than 1 μm are densely arranged on the surface of the component, and the anchor effect improves the bonding strength of the bonding portion when the aluminum component is bonded to the resin component. Furthermore, the base ends of the protrusions that connect to the surface of the component contain not only amorphous alumina but also α-alumina, which has excellent chemical stability, and therefore the bonding strength of the bonding portion is improved. 2nd 6th Immerse in a non-aqueous electrolyte solution containing lithium fluorophosphate with water added. Pickles This improves the difficulty of separation of the resin member when the resin member is pressed against the surface of the resin member. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a perspective view of a battery according to an embodiment. [Figure 2] 2 is a cross-sectional view taken along the line AA in FIG. 1. [Figure 3] FIG. 2 is a perspective view of a positive electrode terminal member. [Figure 4] FIG. 2 is a perspective view of a unit member extracted from the battery of FIG. 1. [Figure 5] 4A is a cross-sectional view taken along line BB in FIG. 4, and FIG. 4B is a cross-sectional view taken along line CC in FIG. [Figure 6] (A) is an explanatory diagram illustrating the bonding area between the upper surface of the lid member and the positive electrode resin member, and the area on the upper surface of the lid member that has been roughened, and (B) is an explanatory diagram illustrating the bonding area between the lower surface of the lid member and the positive electrode resin member, and the area on the lower surface of the lid member that has been roughened. [Figure 7] FIG. 1A is an explanatory diagram illustrating the joint area between a part of the side surface of the positive electrode terminal member and the positive electrode resin member, and the area on the part of the side surface of the positive electrode terminal member that has been roughened; and FIG. 1B is an explanatory diagram illustrating the joint area between the underside of the long straight portion of the positive electrode terminal member and the positive electrode resin member, and the area on the underside of the long straight portion of the positive electrode terminal member that has been roughened. [Figure 8]This image shows how a pulsed laser was actually irradiated onto the surface of an aluminum component under the same conditions as the pulsed laser irradiation for the roughened area, resulting in the formation of numerous nano-order protrusions on the component surface, which are arranged in a dense, mesh-like pattern. [Figure 9] (A) is an enlarged projection image of a cross-sectional sample obtained by TEM-EELS, (B-1) is a mapping image (chemical state analysis result) showing chemical state A, (B-2) is a mapping image (chemical state analysis result) showing chemical state B, and (B-3) is a mapping image (chemical state analysis result) showing chemical state C. [Figure 10] This is a graph showing the EELS spectrum of an Al-related compound obtained from an analysis company and the EELS spectrum obtained from the cross-sectional sample in this study. [Figure 11] 3 is a flowchart of a method for manufacturing a battery according to an embodiment. [Figure 12] 1A is a diagram schematically illustrating the roughening treatment for the roughened region on the lower surface of the lid, and FIG. 1B is a diagram schematically illustrating the roughening treatment for the roughened region on the side surface of the terminal. [Figure 13] 1A to 1C are diagrams illustrating a schematic diagram of an insert molding process. [Figure 14] (A) is a table showing the results of the acid resistance test, and (B) is a table showing the results of the hydrofluoric acid resistance test. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. A battery 1 constituting an aluminum resin composite according to the present invention is an example of an electricity storage device, specifically, a rectangular, sealed lithium-ion secondary battery installed in vehicles such as hybrid cars, plug-in hybrid cars, and electric vehicles. In the following, the symbols X, Y, and Z indicating directions in the drawings represent left-right, front-rear, and up-down directions. Furthermore, the symbols U, D, L, R, F, and B at the end of the arrows indicating each direction represent upper, lower, left, right, front, and rear directions. However, these directions and positions are specified for the sake of convenience. Therefore, the orientation in which the battery 1 is installed is not limited in any way.

[0012] [Battery configuration] Fig. 1 is a perspective view of a battery 1. Fig. 2 is a cross-sectional view taken along line AA in Fig. 1. As shown in Figs. 1 and 2, the battery 1 has a case 10 that seals the interior, an electrode assembly 40 housed in the case 10, an electrolyte 3, an insulating holder 5, and a positive electrode terminal member 50 and a negative electrode terminal member 60 connected to the electrode assembly 40.

[0013] Case 10 has an overall flat, bottomed rectangular parallelepiped shape. Case 10 is composed of a main body member 20 and a cover member 30. In this embodiment, case 10 is made of aluminum. However, the material of case 10 may be an aluminum-based metal other than aluminum, such as an aluminum alloy. Furthermore, the material of case 10 may be a metal other than aluminum-based metal, such as an iron-based metal.

[0014] The main body member 20 has a rectangular cylindrical shape with a bottom. The main body member 20 also has an opening 21. In other words, the main body member 20 has a rectangular plate-shaped bottom 12, a pair of front and rear portions 13 and 14 extending perpendicularly from the edges of the front side F and the rear side B of the bottom 12, and a pair of left and right portions 15 and 16 extending perpendicularly from the end of the left side L and the end of the right side R of the bottom 12. The opening 21 has a rectangular shape with its long side extending in the left-right direction X and its short side extending in the front-to-back direction Y. The bottom 12 has a rectangular plate-like shape with its long side extending in the left-to-right direction X and its short side extending in the front-to-back direction Y. The front and rear portions 13 and 14 have rectangular plate-like shapes with their long side extending in the left-to-right direction X and their short side extending in the up-to-down direction Z. The left and right portions 15 and 16 have rectangular plate-like shapes with their long side extending in the up-to-down direction Z and their short side extending in the front-to-back direction Y.

[0015] The height (length in the vertical direction Z) of the front side portion 13 and the rear side portion 14 is the same as the height (length in the vertical direction Z) of the left side portion 15 and the right side portion 16. Furthermore, the height (length in the vertical direction Z) of the front side portion 13, etc. and the length in the horizontal direction X of the front side portion 13 and the rear side portion 14 are considerably longer than the length in the vertical direction Y of the left side portion 15 and the right side portion 16. Therefore, in the following, for the case 10, the main body member 20, and the cover member 30, the horizontal direction X will be referred to as the "length direction," the vertical direction Y will be referred to as the "width direction," and the vertical direction Z are sometimes referred to as the "height direction."

[0016] The lid member 30 closes the opening 21 of the main body member 20. More specifically, the peripheral edge of the lid member 30 is laser welded along the entire periphery to the tip ends of the upper sides U of the front side portion 13, rear side portion 14, left side portion 15, and right side portion 16. At the boundary between the tip end of the main body member 20 and the peripheral edge of the lid member 30, a melted and solidified portion 18 is formed along the entire periphery, where the main body member 20 and the lid member 30 are melted and solidified by the laser.

[0017] A safety valve 19 is provided on the lid member 30 slightly to the left L of the center in the left-right direction X. The safety valve 19 ruptures and opens when the internal pressure of the case 10 exceeds a valve opening pressure. A liquid inlet hole 30k that penetrates the lid member 30 in the up-down direction Z is formed on the lid member 30 slightly to the right R of the center in the left-right direction X. An aluminum sealing member 39 is fitted into the liquid inlet hole 30k from an upper side U, thereby airtightly sealing the liquid inlet hole 30k.

[0018] A positive electrode insertion hole 33h penetrating the lid member 30 in the up-down direction Z is formed near an end of the lid member 30 on one side in the left-right direction X (left side L in FIGS. 1 and 2). A negative electrode insertion hole 34h penetrating the lid member 30 in the up-down direction Z is formed near an end of the lid member 30 on the other side in the left-right direction X (right side R in FIGS. 1 and 2). The positive electrode insertion hole 33h and the negative electrode insertion hole 34h are formed in a rectangular shape with the long side extending in the left-right direction X and the short side extending in the front-rear direction Y. A generally vertically elongated positive electrode terminal member 50 (extending in one direction) is inserted into the positive electrode insertion hole 33h from the upper side U along its length. A generally vertically elongated negative electrode terminal member 60 (extending in one direction) is inserted into the negative electrode insertion hole 34h from the upper side U along its length.

[0019] The positive electrode terminal member 50 is fixed to the lid member 30 in a state insulated from the lid member 30 via the positive electrode resin member 70. Therefore, the positive electrode terminal member 50 is supported by the lid member 30 via the positive electrode resin member 70. In this embodiment, the positive electrode terminal member 50 is made of aluminum. However, the material of the positive electrode terminal member 50 can be appropriately selected as long as it can be electrically connected to the positive electrode current collecting portion 41r of the electrode body 40, which will be described later.

[0020] The negative electrode terminal member 60 is fixed to the lid member 30 in a state insulated from the lid member 30 via the negative electrode resin member 80. Therefore, the negative electrode terminal member 60 is supported by the lid member 30 via the negative electrode resin member 80. In this embodiment, the negative electrode terminal member 60 is made of copper. However, the material of the negative electrode terminal member 60 can be appropriately selected as long as it can be electrically connected to the negative electrode current collecting part 42r of the electrode body 40, which will be described later.

[0021] The electrode body 40 is a so-called "wound-type" electrode body. In the electrode body 40, a strip-shaped positive electrode plate 41 and a strip-shaped negative electrode plate 42 are wound in a predetermined winding direction with a strip-shaped separator 43 sandwiched therebetween. As a result, the electrode body 40 is formed in an overall flat shape with horizontally elongated rectangular side surfaces extending in the up-down direction Z and the left-right direction X on the front side F and the rear side B.

[0022] The positive electrode plate 41 has a positive electrode current collector foil (not shown) and a positive electrode active material layer (not shown) supported on the current collector foil. The positive electrode current collector foil is made of aluminum. However, the material of the positive electrode current collector foil can be appropriately selected within a range that allows it to function as a positive electrode of a lithium-ion secondary battery. On the other hand, the negative electrode plate 42 has a negative electrode current collector foil (not shown) and a negative electrode active material layer (not shown) supported on the current collector foil. The negative electrode current collector foil is made of copper. However, the material of the negative electrode current collector foil can be appropriately selected within a range that allows it to function as a negative electrode of a lithium-ion secondary battery.

[0023] The electrode body 40 also has a positive electrode current collector 41r formed thereon. The positive electrode current collector 41r is a portion where the positive electrode current collector foil is exposed. A positive electrode terminal lower portion 52 of the positive electrode terminal member 50 is bonded to the positive electrode current collector 41r. Similarly, the electrode body 40 also has a negative electrode current collector 42r formed thereon. The negative electrode current collector 42r is a portion where the negative electrode current collector foil is exposed. A negative electrode terminal lower portion 62 of the negative electrode terminal member 60 is bonded to the negative electrode current collector 42r. Therefore, the electrode body 40 is supported by the cover member 30 via the positive electrode terminal member 50 and the negative electrode terminal member 60.

[0024] Although detailed illustration is omitted, the positive electrode current collecting portion 41r is a portion that protrudes beyond the negative electrode plate 42 and separator 43 in the axial direction of the electrode body 40 and is wound with only the positive electrode current collecting foil. Similarly, the negative electrode current collecting portion 42r is a portion that protrudes beyond the positive electrode plate 41 and separator 43 in the axial direction of the electrode body 40 and is wound with only the negative electrode current collecting foil. In this embodiment, the positive electrode current collecting portion 41r is formed at the end of the left side L of the electrode body 40. On the other hand, the negative electrode current collecting portion 42r is formed at the end of the right side R of the electrode body 40.

[0025] The electrode assembly 40 is spaced a certain distance from the bottom 12, front 13, rear 14, left 15, and right 16 of the main body member 20, as well as the cover member 30. An insulating holder 5 is disposed between the electrode assembly 40 and the main body member 20 to reliably maintain insulation. The shape and material of the insulating holder 5 can be appropriately determined as long as it can be disposed between the electrode assembly 40 and the main body member 20 and can insulate the electrode assembly 40 from the main body member 20. In this embodiment, the insulating holder 5 is made of a strip-shaped film of polypropylene (PP), a synthetic resin. The insulating holder 5 is formed in a bag shape. The bag-shaped insulating holder 5 encases the electrode assembly 40 with the upper side U open. That is, the insulating holder 5 insulates the inner surfaces of the bottom 12, front side 13, rear side 14, left side 15 and right side 16 of the main body member 20 from the outer surface of the electrode body 40 facing the main body member 20.

[0026] The positive electrode resin member 70 is made of a thermoplastic resin, specifically polyphenylene sulfide (PPS). The positive electrode resin member 70 is bonded to the lid member 30 and the positive electrode terminal member 50. The lid member 30, the positive electrode terminal member 50, and the positive electrode resin member 70 are integrated by bonding the positive electrode resin member 70 to the lid member 30 and the positive electrode terminal member 50, and the battery 1 including this integrated assembly constitutes a composite of aluminum and resin. The positive electrode resin member 70 also provides insulation between the lid member 30 and the positive electrode terminal member 50 while airtightly sealing them. That is, the positive electrode resin member 70 functions as an insulating member and a sealing member between the lid member 30 and the positive electrode terminal member 50. The material of the positive electrode resin member 70 can be appropriately selected as long as it can hermetically seal the lid member 30 and the positive electrode terminal member 50 while insulating them from each other, and can also be other types of resin such as other types of thermoplastic resins or thermosetting resins.

[0027] The negative electrode resin member 80 is made of a thermoplastic resin, specifically polyphenylene sulfide (PPS). The negative electrode resin member 80 is bonded to the lid member 30 and the negative electrode terminal member 60. The lid member 30, the negative electrode terminal member 60, and the negative electrode resin member 80 are integrated by bonding the negative electrode resin member 80 to the lid member 30 and the negative electrode terminal member 60, and the battery 1 including this integrated member constitutes a composite of metal and resin. The negative electrode resin member 80 also provides insulation between the lid member 30 and the negative electrode terminal member 60 and hermetically seals them. That is, the negative electrode resin member 80 functions as an insulating member and a sealing member between the lid member 30 and the negative electrode terminal member 60. The material of the negative electrode resin member 80 can be appropriately selected as long as it can hermetically seal the lid member 30 and the negative electrode terminal member 60 while insulating them from each other, and can also be other types of resin such as other types of thermoplastic resins or thermosetting resins.

[0028] Next, the shape of the positive electrode terminal member 50 will be described. Fig. 3 is a perspective view of the positive electrode terminal member 50. As shown in Fig. 3, the positive electrode terminal member 50 has a positive electrode terminal upper portion 51, a positive electrode terminal lower portion 52, and a positive electrode terminal intermediate portion 53. In the battery 1, the positive electrode terminal upper portion 51 is disposed on the upper side U relative to the battery 1. The positive electrode terminal lower portion 52 is disposed on the lower side D relative to the battery 1.

[0029] The positive terminal upper portion 51 has a constant L-shaped cross section in one direction. In detail, one straight portion of the L-shaped cross section of the positive terminal upper portion 51 is longer than the other straight portion. Therefore, the rectangular plate-shaped portion of the positive terminal upper portion 51 that corresponds to the longer straight portion of the L-shaped cross section is referred to as the "long straight portion 51a," and the portion extending perpendicularly from one edge of the long straight portion 51a is referred to as the "short straight portion 51b."

[0030] In the following description of the positive electrode terminal member 50, for convenience, the symbols O, P, and Q shown in FIG. 3 are used to identify directions. The symbols O, P, and Q represent the "direction in which the L-shaped cross-section of the positive electrode terminal upper portion 51 extends at a constant angle," the "direction along the straight line of the long straight portion 51a," and the "direction along the straight line of the short straight portion 51b," respectively. In the following description of the positive electrode terminal member 50, the side in the third direction Q where the positive electrode terminal upper portion 51 is located may be referred to as the "upper side," and the side in the third direction Q where the positive electrode terminal lower portion 52 is located may be referred to as the "lower side."

[0031] The positive terminal lower portion 52 is formed perpendicular to the long straight portion 51a as a whole. The positive terminal lower portion 52 is shaped like a rectangular plate with its long side extending in the third direction Q and its short side extending in the second direction P. In addition, in the first direction O, a portion of the positive terminal lower portion 52 is contained within the positive terminal upper portion 51, while another portion protrudes outside the positive terminal upper portion 51. In addition, in the second direction P, a portion of the positive terminal lower portion 52 is contained within the positive terminal upper portion 51, while another portion protrudes outside the positive terminal upper portion 51.

[0032] The positive terminal intermediate portion 53 has an overall crank shape and connects the positive terminal upper portion 51 and the positive terminal lower portion 52. When viewed from the second direction P, the shape of the positive terminal intermediate portion 53 is such that the first direction O is the long side direction and the third direction O is the short side direction. Q The positive terminal intermediate portion 53 has a rectangular shape with its short side in the first direction O. The length of the positive terminal intermediate portion 53 in the first direction O is longer than the length of the positive terminal lower portion 52 in the first direction O. The side surface of the positive terminal lower portion 52 that protrudes outward from the positive terminal upper portion 51 in the first direction O is continuous with the side surface of the positive terminal intermediate portion 53 on the same side in the first direction O.

[0033] Furthermore, both surfaces of the positive terminal intermediate portion 53 that are perpendicular to the second direction P near the connection to the short straight portion 51b are formed on the same plane as both surfaces of the short straight portion 51b that are perpendicular to the second direction P. Hereinafter, the portion of the positive terminal intermediate portion 53 that is formed on the same plane as both surfaces of the short straight portion 51b that are perpendicular to the second direction P will be referred to as the "upper connection portion 53a." The surface of the positive terminal upper portion 51, including the short straight portion 51b, on the side where the positive terminal lower portion 52 is located in the second direction P is flush with the surface of the upper connection portion 53a on the same side. Furthermore, a bent portion 53b that is bent in a crank shape toward the outside of the positive terminal upper portion 51 along the second direction P is formed on the side of the upper connection portion 53a opposite the short straight portion 51b in the third direction Q.

[0034] In this embodiment, the shape of the negative electrode terminal member 60 is the same as the shape of the positive electrode terminal member 50. Therefore, although a description using a perspective view of the negative electrode terminal member 60 will be omitted, the negative electrode terminal member 60, like the positive electrode terminal member 50, has a negative electrode terminal upper portion 61, a negative electrode terminal lower portion 62, and a negative electrode terminal intermediate portion 63 that correspond to the positive electrode terminal upper portion 51, the positive electrode terminal lower portion 52, and the positive electrode terminal intermediate portion 53.

[0035] Next, the bonding structure between the positive electrode resin member 70 and the lid member 30 and the positive electrode terminal member 50, as well as the roughening treatment of the lid member 30 and the positive electrode terminal member 50, will be described. FIG. 4 is a perspective view of a unit member 1A that constitutes a part of the battery 1 shown in FIGS. 1 and 2 and is composed of the integrated lid member 30, the positive electrode terminal member 50, the positive electrode resin member 70, and the negative electrode terminal member 60 and the negative electrode resin member 80. FIG. 5(A) is a cross-sectional view taken along line BB in FIG. 4, and FIG. 5(B) is a cross-sectional view taken along line CC in FIG. 4. FIG. 6 is an explanatory diagram illustrating the bonding region between the lid member 30 and the positive electrode resin member 70 and the roughened region of the lid member 30. FIG. 7 is an explanatory diagram illustrating the bonding region between the positive electrode terminal member 50 and the positive electrode resin member 70 and the roughened region of the positive electrode terminal member 50.

[0036] The positive electrode terminal member 50 is fixed to the lid member 30 via the positive electrode resin member 70 with the first direction O parallel to the left-right direction X and the positive electrode terminal lower portion 52 located on the rear side B. On the other hand, the negative electrode terminal member 60 is fixed to the lid member 30 via the negative electrode resin member 80 with the first direction O parallel to the left-right direction X and the negative electrode terminal lower portion 62 located on the front side F.

[0037] The upper surface of the long straight portion 51a is exposed to the upper side U. In addition, the upper surface of the lid member 30 and the lower surface of the long straight portion 51a are located at approximately the same position in the vertical direction Z. Furthermore, the lower surface of the short straight portion 51b is located slightly lower than the lower surface of the lid member 30 in the vertical direction Z. In a plan view (looking from the upper side U toward the lower side D), the long straight portion 51a of the positive electrode terminal member 50 inserted into the positive electrode insertion hole 33h is completely contained within the positive electrode insertion hole 33h. In addition, in the left-right direction X and the front-back direction Y, the long straight portion 51a is located at approximately the center of the positive electrode insertion hole 33h.

[0038] The positive electrode resin member 70 is formed in the vertical direction Z from the upper end of the positive electrode terminal upper portion 51 to a position U slightly above the lower end of the upper connection portion 53a. The positive electrode resin member 70 hermetically seals the gap between the lid member 30 and the positive electrode terminal member 50. As will be described later, in this embodiment, the positive electrode resin member 70 is integrally formed by insert molding. For convenience, however, the portion of the positive electrode resin member 70 above the upper surface of the lid member 30 will be referred to as the "positive electrode resin upper portion 71," the portion below the lower surface of the lid member 30 will be referred to as the "positive electrode resin lower portion 72," and the portion between the upper and lower surfaces of the lid member 30, in other words, the portion filled in the positive electrode insertion hole 33h, will be referred to as the "positive electrode resin middle portion 73."

[0039] The positive electrode resin upper portion 71 has a positive electrode resin upper frame portion 71a that surrounds the entire periphery of the long straight portion 51a, and a positive electrode resin upper protrusion portion 71b that is connected to the positive electrode resin upper frame portion 71a.

[0040] The positive electrode resin upper frame portion 71a is formed in a rectangular frame shape. A first width W1, which is the distance from the inner edge to the outer edge of each straight portion of the positive electrode resin upper frame portion 71a, is substantially the same. The positive electrode resin upper protrusion 71b is formed to protrude toward the right side R from a partial range approximately in the center of the straight portion formed on the right side R of the positive electrode resin upper frame portion 71a. The positive electrode resin upper protrusion 71b has a rectangular plate shape with its long side direction in the left-right direction X and its short side direction in the front-rear direction Y. The lengths of the positive electrode resin upper protrusion 71b in the left-right direction X and the front-rear direction Y are longer than the first width W1. The positive electrode resin upper protrusion 71b is a location where a gate member GT (see FIG. 13) into which molten resin is injected during insert molding is placed.

[0041] The positive electrode resin upper frame portion 71a is bonded to the entire outer surface of the long straight portion 51a and to a rectangular annular lid upper surface frame bonding region E11 that surrounds the entire edge of the positive electrode insertion hole 33h on the top surface of the lid member 30. A second width W2, which is the distance from the inner edge to the outer edge of each straight portion of the lid upper surface frame bonding region E11, is substantially uniform. The positive electrode resin upper protrusion 71b is bonded to the top surface of the lid member 30 over the entire bottom surface.

[0042] In the following, the region on the top surface of the lid member 30 that is bonded to the positive electrode resin upper protrusion 71b will be referred to as the "lid top surface rectangular bonding region E12." The lid top surface rectangular bonding region E12 is formed to protrude toward the right side R from a partial range approximately in the center of the straight portion on the right side R of the lid top surface frame-shaped bonding region E11. In other words, the lid top surface frame-shaped bonding region E11 and the lid top surface rectangular bonding region E12 are connected and form a bonding region with the positive electrode resin member 70 on the top surface of the lid member 30. Therefore, the lid top surface frame-shaped bonding region E11 and the lid top surface rectangular bonding region E12 will be collectively referred to as the "lid top surface bonding region E1."

[0043] The positive electrode resin lower portion 72 is generally formed in the shape of a rectangular plate with its long sides extending in the left-right direction X and its short sides extending in the front-rear direction Y. The overlapping portion of the positive electrode terminal member 50 in the up-down direction Z is completely embedded inside the positive electrode resin lower portion 72. Therefore, the positive electrode resin lower portion 72 is joined to the entire outer surface of the overlapping portion of the short straight portion 51b and the upper connection portion 53a of the positive electrode terminal member 50 in the up-down direction Z.

[0044] The positive electrode resin lower portion 72 is joined to a rectangular annular lid underside joining region E2 that completely surrounds the edge of the positive electrode insertion hole 33h on the underside of the lid member 30. The distances from the inner edge to the outer edge of each straight line portion of the lid underside joining region E2 are substantially the same on the front side F and the rear side B and are substantially the same on the left side L and the right side R. A fourth width W4, which is the distance from the inner edge to the outer edge of the straight line portion on the left side L and the right side R, is wider than a third width W3, which is the distance from the inner edge to the outer edge of the straight line portion on the front side F and the rear side B.

[0045] The positive electrode resin intermediate portion 73 is connected to the positive electrode resin upper portion 71 and the positive electrode resin lower portion 72. The positive electrode resin intermediate portion 73 also fills the positive electrode insertion hole 33h. Therefore, the positive electrode resin intermediate portion 73 is bonded to the inner surface of the positive electrode insertion hole 33h of the lid member 30 around the entire periphery. Furthermore, the portion of the short straight portion 51b of the positive electrode terminal member 50 that overlaps with it in the up-down direction Z is completely embedded inside the positive electrode resin intermediate portion 73. Therefore, the positive electrode resin intermediate portion 73 is bonded to the entire outer surface of the portion of the short straight portion 51b of the positive electrode terminal member 50 that overlaps with it in the up-down direction Z.

[0046] The entire outer surface of the long straight portion 51a of the positive terminal member 50 is joined to the positive resin upper frame portion 71a. The entire outer surface of the short straight portion 51b of the positive terminal member 50, which overlaps with the positive resin intermediate portion 73 and the positive resin lower portion 72 in the vertical direction Z, is joined to the positive resin intermediate portion 73 and the positive resin lower portion 72. The entire outer surface of the upper connection portion 53a of the positive terminal member 50, which overlaps with the positive resin lower portion 72 in the vertical direction Z, is joined to the positive resin intermediate portion 73 and the positive resin lower portion 72. Therefore, the region of the side surface of the positive terminal member 50 that is flush with the positive terminal upper portion 51 and the upper connection portion 53a and that is joined to the positive electrode resin member 70 is referred to as the "terminal side surface joining region E3." In addition, the area that is joined to the positive electrode resin member 70, which is the entire lower surface of the long straight portion 51a on the side where the positive electrode terminal lower portion 52 is formed in the third direction Q of the positive electrode terminal member 50, is referred to as the ``terminal lower surface joining area E4.''

[0047] As described above, the lid member 30 and the positive electrode terminal member 50 have a plurality of bonding regions with the positive electrode resin member 70. Specific regions of the lid member 30 and the positive electrode terminal member 50, including the bonding regions with the positive electrode resin member 70, are subjected to a roughening treatment by pulsed laser irradiation in order to improve sealing performance. This roughening treatment will now be described.

[0048] The roughening treatment is applied to a roughened lid upper surface region F1 that completely surrounds and accommodates the lid upper surface joining region E1 on the upper surface of the lid member 30, and a roughened lid lower surface region F2 that completely surrounds and accommodates the lid lower surface joining region E2 on the lower surface of the lid member 30. In addition, the roughening treatment is applied to a roughened terminal side surface region F3 that completely surrounds and accommodates the terminal side surface joining region E3 on the entire side surface that is flush across the positive terminal upper portion 51 and the upper connection portion 53a of the positive terminal member 50, and to a roughened terminal lower surface region F4 that is the terminal lower surface joining region E4 itself.

[0049] Although detailed conditions will be described later, the roughening treatment of the roughened lid upper surface region F1, the roughened lid lower surface region F2, the roughened terminal side surface region F3, and the roughened terminal lower surface region F4 is performed by pulsed laser irradiation.The roughened lid upper surface region F1, the roughened lid lower surface region F2, the roughened terminal side surface region F3, and the roughened terminal lower surface region F4 have numerous protrusions arranged in a dense mesh-like pattern throughout.

[0050] "A large number of protrusions are densely arranged in a mesh-like pattern" means that the protrusions formed by pulsed laser irradiation are arranged (forested) with adjacent ones spaced apart from each other in a planar view at a distance at least equal to or less than the overall average diameter of the protrusions, and the gaps between the protrusions are also two-dimensionally expanded and connected in a substantially lattice-like pattern. The "substantially lattice-like pattern" here includes planar shapes other than rectangular, such as diamonds, and is not particularly limited. Furthermore, the substantially lattice-like pattern may or may not be uniform overall.

[0051] The protrusions formed in the roughened lid upper surface region F1 and the roughened lid lower surface region F2 are formed by debris particles generated by pulsed laser irradiation of the surface of the lid member 30, which are joined together in a string of beads and extend in the overall height direction. Similarly, the protrusions formed in the roughened terminal side surface region F3 and the roughened terminal lower surface region F4 are formed by debris particles generated by pulsed laser irradiation of the surface of the positive electrode terminal member 50, which are joined together in a string of beads and extend in the overall height direction.

[0052] Debris particles are particles with a diameter of 100 nm or less that are formed when a pulsed laser is irradiated onto the surface of a metal component, explosively vaporizing part of the surface, and then condense compounds formed when metal vapor or metal atoms react with atmospheric gas. These particles then fall onto the surface near the position where the pulsed laser is irradiated.

[0053] The entirety of the numerous protrusions in the roughened lid upper surface region F1 will be referred to as the "lid upper surface protrusion layer F11." Similarly, the entirety of the numerous protrusions in the roughened lid lower surface region F2, the roughened terminal side surface region F3, and the roughened terminal lower surface region F4 will be referred to as the "lid lower surface protrusion layer F21," "terminal side surface protrusion layer F31," and "terminal lower surface protrusion layer F41."

[0054] The diameter of the numerous protrusions included in each of the protrusion layers F11 to F41 is 5 nm to 20 nm. The overall average diameter (average diameter) of the numerous protrusions included in each of the protrusion layers F11 to F41 is on the nano order of less than 1 μm. "Nano order of less than 1 μm" means on the "nm" level, in other words, several nm to several hundred nm.

[0055] The following method is one example of a method for calculating the average diameter of the numerous protrusions included in each of the protrusion layers F11 to F41. First, a cross-sectional sample of the joint portion between the lid member 30 or the positive electrode terminal member 50 and the positive electrode resin member 70 is prepared using a predetermined cross-sectional sample preparation device (for example, a Cross Section Polisher (registered trademark): manufactured by JEOL Ltd.). Next, the cross-sectional sample is observed using a field emission scanning electron microscope (FE-SEM). Then, the ridge lines of the protrusions of the lid member 30 or the positive electrode terminal member 50 in the cross-sectional sample are identified. Finally, the average diameter of the numerous protrusions in the cross-sectional sample is measured based on the identified ridge lines.

[0056] The height of the numerous protrusions included in each of the protrusion layers F11 to F41 is 10 nm to 1000 nm. The overall average height (mean height) of the numerous protrusions included in each of the protrusion layers F11 to F41 is on the nano order of less than 1 μm. However, the average height of the numerous protrusions included in each of the protrusion layers F11 to F41 is preferably 84 nm to 1000 nm.

[0057] The following method is one example of a method for calculating the average height of the numerous protrusions included in each of the protrusion layers F11 to F41. In this calculation method, first, a plate-shaped aluminum member is prepared as a test piece. This aluminum member test piece is referred to as the "average height test piece." Then, one entire plane of the average height test piece is irradiated with a pulsed laser under the same conditions as the pulsed laser irradiation for each of the roughened regions F1 to F4.

[0058] Next, a cross-sectional sample including the flat portion irradiated with the pulsed laser is prepared from the average height test piece using a predetermined cross-sectional sample preparation device (for example, a Cross Section Polisher (registered trademark): manufactured by JEOL Ltd.). The cross-sectional sample is parallel to the thickness direction of the average height test piece. Next, a cross-sectional image of the cross-sectional sample is obtained using a scanning electron microscope (JEM ARM 200F Dual-X: manufactured by JEOL Ltd.). The magnification of this cross-sectional image is 150,000 times.

[0059] Next, the image processing software "ImageJ" is used to measure the cross-sectional area and base length of the protrusions in the cross-sectional image, and the average height of the protrusions is calculated using the following formula 1. [Formula 1] TIFF0007770092000001.tif9159

[0060] Here, Figure 8 shows an image of an aluminum member surface that was actually irradiated with a pulsed laser under the same conditions as those for the roughened regions F1 to F4, resulting in the formation of numerous nano-order protrusions on the member surface, which are densely arranged in a mesh-like pattern. As shown in Figure 8, numerous protrusions with nano-order diameters and heights are densely arranged in a mesh-like pattern. Note that one scale interval in the lower right corner of the lower image in Figure 8 represents 30 nm.

[0061] Each of the protrusion layers F11 to F41 as a whole contains metallic aluminum, amorphous alumina, and α-alumina. Furthermore, at least the base end portion of each of the protrusion layers F11 to F41, in other words, the range from the base of the protrusion to a height of 20 nm, contains amorphous alumina and α-alumina.

[0062] The presence of metallic aluminum, amorphous alumina, and α-alumina in the protrusions was confirmed by elemental mapping. Specifically, a cross-sectional sample was first prepared by FIB (Focused Ion Beam) from the surface of the aluminum member irradiated with a pulsed laser under the same conditions as those for the roughened regions F1 to F4. The cross-sectional sample included the boundaries between the aluminum member and the numerous protrusions. Next, a magnified projection image of the cross-sectional sample and chemical state analysis results were obtained using TEM-EELS (Transmission Electron Microscopy-Electron Energy Loss Spectroscopy).

[0063] Fig. 9(A) is an enlarged projection image of a cross-sectional sample obtained by TEM-EELS. Fig. 9(B-1) to Fig. 9(B-3) are mapping images of the chemical states contained in the cross-sectional sample obtained by TEM-EELS. In detail, Fig. 9(B-1) is a mapping image (chemical state analysis result) showing chemical state A, Fig. 9(B-2) is a mapping image (chemical state analysis result) showing chemical state B, and Fig. 9(B-3) is a mapping image (chemical state analysis result) showing chemical state C.

[0064] Chemical state A is thought to be metallic aluminum, chemical state B is α-alumina, and chemical state C is amorphous alumina. This is based on a comparison of the EELS spectrum obtained from this cross-sectional sample with the EELS spectrum of Al-related compounds previously obtained from an analysis company (Toray Research Center, Inc.). For reference, each spectrum is shown in Figure 10.

[0065] The following can be inferred from Figures 9(B-1) to 9(B-3). (1) The entire protrusion contains a mixture of metallic aluminum and aluminum oxide (amorphous alumina and α-alumina). (2) Amorphous alumina and α-alumina are mixed at the base end of the protrusion. In other words, the area of ​​α-alumina / area of ​​amorphous alumina is greater than 0.01. (3) At the base end of the protrusion (within 20 nm from the base), the area of ​​α-alumina is larger than the area of ​​amorphous alumina; in other words, there is more α-alumina than amorphous alumina. (4) Although the amount is small compared to amorphous alumina and α-alumina, metallic aluminum is contained in the base end portion of the protrusion. The area of ​​aluminum oxide (amorphous alumina + α-alumina) / area of ​​metallic aluminum + area of ​​aluminum oxide is > 90%.

[0066] The resin (polyphenylene sulfide) of the positive electrode resin member 70 is impregnated up to the base ends (roots) of the protrusions. In other words, the positive electrode resin member 70 is joined to the lid member 30 and the positive electrode terminal member 50 at the base ends (roots) of the protrusions. The fact that the positive electrode resin member 70 is joined at the base ends (roots) of the protrusions of the lid member 30 and the positive electrode terminal member 50 means that the positive electrode resin member 70 is also joined to the lid member 30 and the positive electrode terminal member 50 at the tip ends of the protrusions.

[0067] The joining structure between the negative electrode resin member 80 and the lid member 30 and the negative electrode terminal member 60 is configured similarly to the joining structure between the positive electrode resin member 70 and the lid member 30 and the positive electrode terminal member 50 described above with reference to Figures 5 to 7. The roughening treatment of the joining region of the lid member 30 with the negative electrode resin member 80 and the joining region of the negative electrode terminal member 60 with the negative electrode resin member 80 is configured similarly to the roughening treatment of the lid member 30 and the positive electrode terminal member 50 described above with reference to Figures 5 to 7.

[0068] [Battery manufacturing] Next, a manufacturing method of the battery 1 will be described with reference to the flowchart in Fig. 11. The manufacturing method of the battery 1 includes a member preparation step S1, a protrusion formation step S2, an insert molding step S3, a lid assembly completion step S4, a closing step S5, a welding step S6, a liquid injection and sealing step S7, and an initial charging and aging step S8.

[0069] In the member preparation step S1, a lid member 30, a positive electrode terminal member 50, and a negative electrode terminal member 60 are prepared. Specifically, the lid member 30 is obtained by forming a liquid injection hole 30k, a positive electrode insertion hole 33h, a negative electrode insertion hole 34h, and a safety valve 19 in an aluminum plate using a conventional general processing method. Furthermore, a positive electrode terminal member 50 having the shape shown in FIG. 3 is obtained from the aluminum plate using a conventional general processing method. Furthermore, a negative electrode terminal member 60 having the same shape as the positive electrode terminal member 50 is obtained from a copper plate using a conventional general processing method.

[0070] Following the member preparation step S1, a protrusion formation step S2 is performed. In the protrusion formation step S2, a pulsed laser is applied to the surface of the lid member 30 that will become the roughened lid upper surface region F1 and the roughened lid lower surface region F2 before the protrusions are formed, thereby forming the roughened lid upper surface region F1 and the roughened lid lower surface region F2. Similarly, in the protrusion formation step S2, a roughened terminal side surface region F3 and a roughened terminal lower surface region F4 are formed on the surface of the positive electrode terminal member 50 that will become the roughened terminal side surface region F3 and the roughened terminal lower surface region F4 before the protrusions are formed.

[0071] As an example of the irradiation conditions for pulsed laser irradiation in the protrusion forming step S2, the energy density of one pulse of laser irradiation is 24 J / cm in the case of aluminum. 2 , and 32 J / cm for copper. 2 For example, for aluminum, the wavelength is set to 1060 nm, the average power to 25 W, the pulse period to 40 μs, the pulse width to 50 ns, the spot diameter to 63 μm, the feed rate to 1450 mm / s, and the line pitch to 0.059 mm. Figure 12 is a schematic diagram showing the trajectory of pulse laser irradiation when pulse laser is irradiated onto the lid undersurface roughened region F2 and the terminal side surface roughened region F3 in the protrusion forming process S2.

[0072] As shown in FIG. 12(A), the roughened lid undersurface region F2 is irradiated with a pulsed laser beam from the tip (the side marked "start point" in FIG. 12(A)) of one side of the roughened lid undersurface region F2 along the left-right direction X (the left side L in FIG. 12(A)), traveling toward one side in the front-rear direction Y (the rear side B in FIG. 12(A)). Subsequently, the pulsed laser beam is shifted by the set line pitch (0.059 mm) toward the other side in the front-rear direction Y (the right side R in FIG. 12(A)). Then, the pulsed laser beam is again shifted by the set line pitch (0.059 mm) toward the other side in the front-rear direction X (the right side R in FIG. 12(A)), traveling toward the rear side B in FIG. 12(A). Thereafter, the pulse laser irradiation is repeated until the pulse laser irradiation proceeds to one side or the other in the front-to-back direction Y and reaches the tip (the side marked "end point" in Figure 12(A)) of the other side (the right side R in Figure 12(A)) along the left-to-right direction X in the lid undersurface roughened region F2.

[0073] By irradiating the roughened underside of the lid F2 with a pulsed laser under the above conditions, a dense network of protrusions containing metallic aluminum, amorphous alumina, and α-alumina and having diameters and heights on the order of nanometers is formed on the surface of the lid member 30 made of metallic aluminum.

[0074] The position where pulsed laser irradiation of the roughened lid lower surface region F2 starts (the side marked "start point" in FIG. 12(A)) is not limited to that shown in FIG. 12(A), and the side marked "end point" in FIG. 12(A) may be the position where pulsed laser irradiation starts. Furthermore, pulsed laser irradiation of the roughened lid upper surface region F1 is also performed in the same manner as pulsed laser irradiation of the roughened lid lower surface region F2 shown in FIG. 12(A). However, pulsed laser irradiation of the roughened lid upper surface region F1 and pulsed laser irradiation of the roughened lid lower surface region F2 may be performed in different ways.

[0075] As shown in FIG. 12B , the roughened terminal side surface region F3 is irradiated with a pulsed laser beam traveling in one direction along the second direction P of the positive terminal member 50 at the tip of one side of the roughened terminal side surface region F3 along the third direction Q of the positive terminal member 50 (the side marked “start point” in FIG. 12B ). Subsequently, the pulsed laser beam is shifted toward the other side of the positive terminal member 50 along the third direction Q by the set line pitch (0.059 mm) and irradiated in the other direction along the second direction P. Then, the pulsed laser beam is shifted toward the other side of the positive terminal member 50 along the third direction Q by the set line pitch (0.059 mm) and irradiated again in one direction along the second direction P. Subsequently, the pulsed laser beam irradiation traveling in one direction or the other along the second direction P is repeated until it reaches the tip of the other side of the roughened terminal side surface region F3 along the third direction Q (the side marked “end point” in FIG. 12B ).

[0076] By irradiating the terminal side roughened region F3 with a pulsed laser under the above conditions, a network-like, dense array of protrusions containing metallic aluminum, amorphous alumina, and α-alumina and having diameters and heights on the nanometer order is formed on the surface of the positive electrode terminal member 50 made of metallic aluminum.

[0077] The position where pulsed laser irradiation of the roughened terminal side surface region F3 starts (the side marked "start point" in FIG. 12(B)) is not limited to that shown in FIG. 12(B). The position where pulsed laser irradiation starts may be the side marked "end point" in FIG. 12(B). Furthermore, pulsed laser irradiation of the roughened terminal lower surface region F4 is performed in the same manner as pulsed laser irradiation of the roughened terminal side surface region F3 shown in FIG. 12(B). In this case, however, the direction of pulsed laser irradiation is the same as that of laser irradiation of the roughened terminal side surface region F3, but the start and end positions of pulsed laser irradiation are at the ends of one side and the other side of the roughened terminal lower surface region F4 along the second direction P of the positive electrode terminal member 50. Furthermore, the direction in which pulsed laser irradiation is shifted by the set line pitch (0.059 mm) is one side of the second direction P of the positive electrode terminal member 50.

[0078] In the protrusion forming process S2, the joining region of the lid member 30 around the negative electrode insertion hole 34h with the negative electrode resin member 80 is irradiated with pulsed laser in substantially the same manner as the lid upper surface roughened region F1 and the lid lower surface roughened region F2, except for the energy density. Similarly, the joining region of the negative electrode terminal member 60 with the negative electrode resin member 80 is irradiated with pulsed laser in substantially the same manner as the terminal side surface roughened region F3 and the terminal lower surface roughened region F4, except for the energy density. Here, "substantially the same manner" refers to the region to be irradiated with pulsed laser and the conditions for pulsed laser irradiation.

[0079] Following the protrusion forming step S2, the insert molding step S3 is performed. In the insert molding step S3, a positive electrode resin member 70 and a negative electrode resin member 80 are formed, and the positive electrode resin member 70 is joined to the lid member 30 and the positive electrode terminal member 50 to form an integrated body, and the negative electrode resin member 80 is joined to the lid member 30 and the negative electrode terminal member 60 to form an integrated body. In other words, the unit member 1A, which is an aluminum resin composite, is produced. FIG. 13 is an explanatory diagram schematically illustrating the insert molding step S3 on the positive electrode terminal member 50 side.

[0080] In the insert molding step S3, a mold DE is used. The mold DE has a lower mold DE1 disposed on the lower side and an upper mold DE2 disposed on the upper side. First, the lower mold DE1 and the upper mold DE2 are set together to place the lid member 30, the positive electrode terminal member 50, and the negative electrode terminal member 60 in their predetermined positions. At this time, the mold DE integrally supports the positive electrode terminal member 50 inserted into the positive electrode insertion hole 33h, the negative electrode terminal member 60 inserted into the negative electrode insertion hole 34h, and the lid member 30. The set lower mold DE1 and upper mold DE2 also form spaces corresponding to the positive electrode resin member 70 and the negative electrode resin member 80.

[0081] In the insert molding process S3, first, a filling process S31 is performed, followed by a solidification process S32. In the filling process S31, as shown in Fig. 13, molten resin MR, which is the material for the positive electrode resin member 70 and the negative electrode resin member 80, is injected from the gate member GT through the upper mold DE2 into the space formed by the lower mold DE1 and the upper mold DE2. At this time, for example, the molten resin MR fills the gaps between the many protrusions until it reaches the bases of the protrusions.

[0082] The material of the positive electrode resin member 70 and the negative electrode resin member 80 is mainly composed of polyphenylene sulfide. The material of the positive electrode resin member 70 and the negative electrode resin member 80 also contains a glass filler. The linear expansion coefficient of the material of the positive electrode resin member 70 and the negative electrode resin member 80 is set between the linear expansion coefficient of copper (1.65) and the linear expansion coefficient of aluminum (2.31).

[0083] After the injection of the molten resin MR is completed, the molten resin MR is appropriately cooled in the solidification step S32 to form the positive electrode resin member 70 and the negative electrode resin member 80. Specifically, for example, the molten resin MR filled the gaps between the numerous protrusions included in the roughened regions F1 to F4 in the filling step S31 until it reached the bases of the protrusions is solidified to form the positive electrode resin member 70 bonded to the bonding regions E1 to E4 including the roughened regions F1 to F4. Similarly, the negative electrode resin member 80 is also formed. Then, the upper mold DE2 is moved upward, and the unit member 1A consisting of the integrated lid member 30, positive electrode resin member 70, positive electrode terminal member 50, negative electrode resin member 80, and negative electrode terminal member 60 is removed from the lower mold DE1.

[0084] Following the insert molding step S3, a lid assembly completion step S4 is performed. In the lid assembly completion step S4, the lid assembly is completed. Specifically, an electrode body 40 is prepared, and the positive electrode terminal lower portion 52 and the negative electrode terminal lower portion 62 of the unit member 1A produced in the insert molding step S3 are welded and connected to the positive electrode current collecting portion 41r and the negative electrode current collecting portion 42r of the electrode body 40, respectively. The electrode body 40 in this state is then wrapped in a bag-shaped insulating holder 5. As a result, a lid assembly consisting of the lid member 30, positive electrode terminal member 50, negative electrode terminal member 60, positive electrode resin member 70, negative electrode resin member 80, electrode body 40, and insulating holder 5 is completed.

[0085] The lid assembly completion step S4 is followed by the closing step S5. In the closing step S5, the main body member 20 is prepared, and the portion of the lid assembly completed in the lid assembly completion step S4 below the lid member 30, including the electrode body 40 and the insulating holder 5, is inserted into the main body member 20, and the opening 21 of the main body member 20 is closed with the lid member 30.

[0086] After the closing step S5, a welding step S6 is performed. In the welding step S6, the leading ends of the front side portion 13, the rear side portion 14, the left side portion 15, and the right side portion 16 of the main body member 20 are laser-welded to the peripheral edge of the cover member 30 along the entire periphery, thereby airtightly sealing the opening 21.

[0087] Following the welding step S6, a liquid injection and sealing step S7 is performed. In the liquid injection and sealing step S7, the electrolyte 3 is injected into the case 10 through the liquid injection hole 30k, and the electrolyte 3 is impregnated into the electrode body 40. Thereafter, the sealing member 39 is fitted into the liquid injection hole 30k from the upper side U, and the sealing member 39 is welded to the lid member 30 around its entire periphery, thereby airtightly sealing the gap between the sealing member 39 and the lid member 30.

[0088] Following the liquid injection and sealing step S7, a charging and aging step S8 is performed. In the charging and aging step S8, 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 for a predetermined time, and the battery 1 is aged. In this way, the battery 1 is completed.

[0089] Next, an experiment to verify the acid resistance and hydrofluoric acid resistance of the joint between an aluminum member and a resin member will be described. The experiment was conducted by the applicant. The experiment will be referred to as the "joint durability verification experiment." The joint durability verification experiment consists of the following three steps (1) to (3). (1) Production of test specimens (2) Acid resistance test (3) Hydrofluoric acid resistance test

[0090] First, (1) the production of the test specimen will be explained. The test specimen is the subject of a joint durability verification experiment. The test specimen is made by joining a plate-shaped aluminum member and a resin member. The resin member is made of polyphenylene sulfide (PPS). The plate-shaped aluminum member is made of metallic aluminum. The plate-shaped aluminum members include those whose surface has been irradiated with a pulse laser under the irradiation conditions related to the protrusion formation step S2 described above, and those whose surface has not been irradiated with a pulse laser.

[0091] In the following, aluminum components irradiated with a pulsed laser are referred to as "irradiated aluminum components," and aluminum components not irradiated with a pulsed laser are referred to as "non-irradiated aluminum components." In the joint durability verification experiment, three irradiated aluminum components and three non-irradiated aluminum components were prepared for the acid resistance test, and three irradiated aluminum components and three non-irradiated aluminum components were prepared for the hydrofluoric acid resistance test.

[0092] Each aluminum member is formed into a square shape in plan view, with each side of the square measuring 50 mm, and the thickness of the metal member being 0.5 mm.

[0093] Furthermore, a roughened region is formed on the surface of each irradiated aluminum member on the side to be joined with the resin member by irradiating with a pulsed laser under the irradiation conditions of the protrusion forming step S2 described above. The shape of the roughened region is a circle with a diameter of 20 mm. The center of the roughened region approximately coincides with the center of the irradiated aluminum member. Similar to the roughened regions F1 to F4 described above, the roughened region is formed with numerous protrusions with diameters and heights on the nano-order level, arranged in a dense mesh-like pattern.

[0094] A resin member was bonded to each aluminum member by insert molding. The resin member was a circular plate. The diameter of the resin member was 16 mm, and the height of the resin member was 3 mm. The center of the resin member was approximately aligned with the center of the aluminum member. In this experiment, the resin member was bonded to the irradiated aluminum member within the roughened region.

[0095] Next, (2) Acid Resistance Test will be described. In the acid resistance test, the irradiated aluminum member and the non-irradiated aluminum member were each immersed in 0.1 mol / L hydrochloric acid. Next, one irradiated aluminum member and one non-irradiated aluminum member were removed 1, 5, and 24 hours after immersion. Then, for each immersion time, one hour after removal, the presence or absence of peeling of the resin member from the aluminum member was confirmed.

[0096] Finally, (3) Hydrofluoric Acid Resistance Test will be described. In the hydrofluoric acid resistance test, the irradiated aluminum member and the non-irradiated aluminum member were each immersed in an electrolyte solution consisting of 1M LiPF6 and an EC / DEC ratio of 1:1, with 1200 ppm of water added. Next, one irradiated aluminum member and one non-irradiated aluminum member were removed 1, 5, and 24 hours after immersion. Then, for each immersion time, one hour after removal, the presence or absence of peeling of the resin member from the aluminum member was confirmed.

[0097] 14(A) is a table showing the results of the (2) acid resistance test, and FIG. 14(B) is a table showing the results of the (3) hydrofluoric acid resistance test. The tables in FIG. 14(A) and FIG. 14(B) show the results of the respective aluminum members. immersion This shows the relationship between time and the presence or absence of peeling.

[0098] As shown in Figure 14(A), (2) the results of the acid resistance test showed that the irradiated aluminum components were peeled off. but For non-irradiated aluminum components, The immersion time 24 hours of In addition, as shown in Figure 14(B), (3) the results of the hydrofluoric acid resistance test showed that irradiated aluminum components sometimes peeled off. but For non-irradiated aluminum components, The immersion time 24 hours ofPeeling sometimes occurred. Therefore, it is thought that the acid and hydrofluoric acid resistance of the joint with the resin component is higher for irradiated aluminum components than for non-irradiated aluminum components. Although detailed explanations are omitted, elemental mapping was performed on all irradiated aluminum components using the FIB method and TEM-EELS described above. The results confirmed the presence of α-alumina in all irradiated aluminum components. Furthermore, it is thought that an oxide film has formed on the surface of the non-irradiated aluminum components, and that no α-alumina is present. Therefore, it can be said that the acid and hydrofluoric acid resistance of the joint with the resin component is higher when the protrusions contain α-alumina than when the protrusions do not contain α-alumina.

[0099] As described above, since a large number of nano-order protrusions each having a diameter and height of less than 1 μm are densely arranged on the surfaces of the lid member 30 and the positive electrode terminal member 50 made of metal aluminum, the anchor effect improves the bonding strength of the bonded portion when the positive electrode resin member 70 is bonded to the lid member 30 and the positive electrode terminal member 50. Furthermore, the base ends of the protrusions that connect to the member surfaces contain not only amorphous alumina but also α-alumina, which has excellent chemical stability, and therefore the acid resistance and hydrofluoric acid resistance of the bonded portion, and even when immersed in a non-aqueous electrolyte solution containing hydrochloric acid or lithium hexafluorophosphate to which water has been added, are improved. Pickles The positive electrode resin member 70 is less likely to peel off when the base end of the many protrusions is immersed in a non-aqueous electrolyte solution containing hydrochloric acid or lithium hexafluorophosphate and water. Pickles This further improves the difficulty in separating the positive electrode resin member 70 when the positive electrode resin member 70 is heated.

[0100] Furthermore, since the positive electrode resin member 70 fills the gaps between the numerous protrusions formed in the roughened regions F1 to F4, the aluminum resin composite has improved bonding strength at the bonding portion between the aluminum member and the resin member, and the bonding portion is resistant to acid and hydrofluoric acid, and is therefore resistant to immersion in a non-aqueous electrolyte solution containing hydrochloric acid or lithium hexafluorophosphate to which water has been added. Pickles This further improves the difficulty in separating the positive electrode resin member 70 when the positive electrode resin member 70 is heated.

[0101] Furthermore, in the protrusion forming step S2, protrusions containing α-alumina and having a diameter and height on the order of nanometers are formed in a densely arranged mesh-like state, and in the insert molding step S3, the gaps between the numerous protrusions can be filled with the positive electrode resin member 70. This improves the bonding strength of the bonding portions between the cover member 30 and the positive electrode terminal member 50 and the positive electrode resin member 70, and also improves the acid resistance and hydrofluoric acid resistance of the bonding portions, and further improves the resistance of the bonding portions to immersion in a non-aqueous electrolyte solution containing hydrochloric acid or lithium hexafluorophosphate to which water has been added. Pickles This further improves the difficulty in separating the positive electrode resin member 70 when the positive electrode resin member 70 is heated.

[0102] It should be noted that this embodiment is merely an example and does not limit the present invention in any way. Naturally, the present invention can be improved and modified in various ways without departing from the spirit and scope of the present invention. Improved examples and modifications of this embodiment will be described below.

[0103] In this embodiment, a flat wound electrode body 40 is exemplified as the electrode body housed in the case 10, but the electrode body may be a laminated electrode body. Also, in this embodiment, one electrode body is housed in the case 10, but multiple electrode bodies may be housed in the case 10.

[0104] In this embodiment, the case 10 has an overall flat, bottomed rectangular parallelepiped shape; however, the shape of the case 10 can be modified as appropriate and may have other shapes, such as a cylindrical shape. The shapes of one or both of the positive electrode terminal member 50 and the negative electrode terminal member 60 may also be modified as appropriate. Similarly, the shapes of one or both of the positive electrode resin member 70 and the negative electrode resin member 80 may also be modified as appropriate. Furthermore, in this embodiment, the shapes of the positive electrode terminal member 50 and the negative electrode terminal member 60 are the same, but they may be different. Similarly, in this embodiment, the shapes of the positive electrode resin member 70 and the negative electrode resin member 80 are the same, but they may be different.

[0105] In this embodiment, a battery 1 in which a cover member 30 and a positive electrode terminal member 50 made of metal aluminum are joined to a positive electrode resin member 70 is included in the aluminum resin composite of the present invention, but the unit member 1A that constitutes the battery 1 is also included in the aluminum resin composite of the present invention.

[0106] In this embodiment, the present invention is applied to a lithium-ion battery, but it can also be applied to any general power storage device, such as a nickel-metal hydride battery or a nickel-cadmium battery. Furthermore, the use of the present invention is not limited to batteries, but can be widely applied to composites that join aluminum members and resin members.

[0107] In this embodiment, the pulsed laser irradiation conditions in the protrusion formation step S2, in other words, the pulsed laser irradiation conditions for forming protrusions containing metallic aluminum, amorphous alumina, and α-alumina and having nano-order diameters and heights arranged in a dense, mesh-like pattern, are set to a wavelength of 1060 nm, but may be appropriately changed within a range of 1060 to 1080 nm. Similarly, the spot diameter may be appropriately set within a range of 10 to 200 μm. More preferably, the spot diameter may be appropriately set within a range of 50 to 100 μm. Furthermore, the interval between laser irradiations may be set to ±10% of the spot diameter.

[0108] 9(B-2) and 9(B-3), the area of ​​α-alumina is larger than the area of ​​amorphous alumina at the base end of the protrusion (within a range of 20 nm from the base). In other words, it is presumed that more α-alumina is contained than amorphous alumina. However, the content ratio of amorphous alumina and the content ratio of α-alumina may be approximately the same. Alternatively, the content ratio of amorphous alumina may be higher than the content ratio of α-alumina. However, from the viewpoint of acid resistance and hydrofluoric acid resistance, it is preferable that more α-alumina is contained than amorphous alumina.

[0109] In this embodiment, the positive electrode resin member 70 reaches the base ends (roots) of the numerous protrusions that make up the roughened regions F1 to F4. However, for example, the positive electrode resin member 70 may fill the gaps between the numerous protrusions in a state where it reaches the tips of the protrusions as a whole, the part between the tips and the middle, or the part between approximately the middle or the middle and the base end.

[0110] In this embodiment, the roughened regions F1 and F2 are formed over the entire bonding regions E1 and E2, but they may be formed only in parts of the bonding regions E1 and E2. In this case, however, it is preferable that the roughened regions F1 and F2 are formed in an annular shape in the bonding regions E1 and E2 so as to surround the positive electrode insertion hole 33h. In addition, the roughened regions F3 and F4 are formed over the entire bonding regions E3 and E4, but they may be formed only in parts of the bonding regions E3 and E4. In this case, it is preferable that the roughened region F3 is formed over the entire portion of the positive electrode terminal intermediate portion 53 in the bonding region E3. In addition, it is preferable that the roughened region F4 be formed in an annular shape along the periphery of the bonding region E4. [Explanation of symbols]

[0111] 1... battery, 10... case, 20... main body member, 30... cover member, 33h...positive electrode insertion hole, 34h...negative electrode insertion hole, 50...positive electrode terminal member, 60...negative electrode terminal member, 70...positive electrode resin member, 80...negative electrode resin member, 30a, 50a...protrusion, E1…Top joint area, E2…Bottom joint area E3… Terminal side bonding area, E4… Terminal bottom bonding area F1... covers the upper roughening area, F2... covers the lower roughening area. F3…Roughening area on the side of the terminal, F4…Roughening area under the terminal.

Claims

1. Made of metallic aluminum, The surface of the member has nano-order protrusions each having a diameter and height of less than 1 μm, The protrusions are arranged such that adjacent ones in a planar view are spaced apart from each other at a distance at least equal to or less than the overall average value of the diameters of the protrusions, the protrusions contain amorphous alumina and α-alumina at their base ends, which are connected to the surface of the member and extend up to a height of 20 nm from the base of the protrusions; The base end of the protrusion has an aluminum member containing more α-alumina than amorphous alumina, and a resin member bonded to the aluminum member. an aluminum resin composite; a non-aqueous electrolyte solution containing lithium hexafluorophosphate; A battery comprising:

2. The battery of claim 1, The average height of the protrusions is 84 to 1000 nm. battery.

3. A method for manufacturing the battery according to claim 1 or 2, comprising: a protrusion forming step of irradiating a laser beam onto the surface of the member before the protrusion is formed, thereby forming the protrusion on the surface of the member; and after the protrusion forming step, an insert molding step of forming the resin member on the surface of the member by insert molding.

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