Power storage device and method for manufacturing power storage device

Abstract

The invention provides an electricity storage device and a manufacturing method of the electricity storage device. Even if cracks occur in a resin component during joining of a sealing part of a housing component or a terminal component and the resin component, the occurrence of poor sealing can be suppressed. A power storage device (1) is provided with a case member (30), a terminal member (50), and a resin member (70) that fixes the terminal member (50) to the case member (30). At least one of the housing seal section (31) and the terminal seal section (51) has: a plurality of first seal sections (32, 52) which are in a ring shape extending over the entire circumference in the circumferential direction (IAH, IBH) and which have cohesive failure when the joining with the resin member (70) is to be broken; and second seal parts (33, 53) which are disposed between adjacent first seal parts (32, 52), each of which has a ring shape that is continuous over the entire circumference in the circumferential direction (IAH, IBH), and which have an interface failure when the joining with the resin member (70) is to be broken.

Description

Technical Field

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

[0002] As a power storage device, there is known a battery in which a positive and negative terminal parts are fixed to a rectangular plate-shaped shell cover part (shell part) constituting a rectangular box-shaped shell by means of a resin part. Specifically, the positive and negative terminal parts are respectively inserted into insertion holes provided in the shell cover part, and extend from the inside to the outside of the shell. The resin part is airtightly joined to the ring-shaped shell sealing part surrounding the insertion hole in the shell cover part and the ring-shaped terminal sealing part located near the insertion hole in the terminal part while insulating them. As a result, the terminal sealing part of the terminal part and the resin part are airtightly sealed in the width direction of the terminal sealing part (hereinafter, also referred to as the "sealing direction"), and the shell sealing part of the shell cover part and the resin part are airtightly sealed in the width direction of the shell sealing part (hereinafter, also referred to as the "sealing direction"). As a related prior art, for example, Patent Document 1 (refer to Figure 2 , Figure 6 , Figure 7 wait).

[0003] Patent Document 1: Japanese Patent Application Publication No. 2022-079172

[0004] It should be noted that, in the past, the terminal sealing portion and the resin portion of the terminal component were firmly joined to the resin portion over the entire surface of the terminal sealing portion in such a manner that cohesive failure occurs over the entire surface of the terminal sealing portion when their joining is about to be broken. In addition, the housing sealing portion and the resin portion of the housing component were also firmly joined to the resin portion over the entire surface of the housing sealing portion in such a manner that cohesive failure occurs over the entire surface of the housing sealing portion when their joining is about to be broken.

[0005] However, it is known that in such a battery, if the resin part breaks (cracks) during the bonding between the terminal seal and the resin part, or the bonding between the case seal and the resin part, there is a concern that the cracks will extend in the sealing direction and cause the seal to be disconnected (defective sealing). Summary of the invention

[0006] The present invention has been made in view of the above-mentioned current situation, and provides an electric storage device capable of suppressing the occurrence of sealing failure even if cracks occur in the resin member during the bonding between the sealing portion of a case member or a terminal member and the resin member, and a method for manufacturing the electric storage device.

[0007] (1) One embodiment of the present invention for solving the above-mentioned problems is an electrical storage device comprising: a shell member having an insertion hole and including a ring-shaped shell sealing portion surrounding the insertion hole; a terminal member inserted into the insertion hole of the shell member and including a ring-shaped terminal sealing portion located near the insertion hole; and a resin member airtightly bonded to the shell member and the terminal sealing portion of the terminal member while insulating the shell sealing portion of the shell member and fixing the terminal member to the shell member, wherein at least any one of the shell sealing portion and the terminal sealing portion has: a plurality of first sealing portions in a ring shape connected throughout the circumference of the sealing portion, and causing cohesive failure when the bond with the resin member is about to be broken; and second sealing portions respectively arranged between the first sealing portions adjacent to each other in the width direction of the sealing portion, in a ring shape connected throughout the circumference of the sealing portion, and causing interfacial failure when the bond with the resin member is about to be broken.

[0008] In the above-mentioned power storage device, at least one of the case sealing part and the terminal sealing part is not firmly bonded to the resin part in a manner that causes cohesive failure on the entire surface of the sealing part (the entire sealing part is not regarded as the first sealing part), but the sealing part is formed into a form having a plurality of annular first sealing parts that can cause cohesive failure and one or more annular second sealing parts arranged between these first sealing parts and can cause interface failure. Thus, during the manufacture and use of the power storage device, even if cracks occur in the resin part in one first sealing part, it is possible to prevent the cracks from extending to other first sealing parts and destroying all the first sealing parts included in the sealing part.

[0009] That is, taking into account the development of cracks, if cohesive failure occurs in the first sealing part and the cracks develop in the sealing direction, then in the second sealing part adjacent to the first sealing part, the bonding with the resin part is weaker than the bonding between the first sealing part and the resin part, so interface failure is likely to occur. However, in the second sealing part, since the cracks do not maintain their original state and develop in the sealing direction, but also develop in the circumferential direction, the stress can be relieved by the interface failure of the second sealing part. Therefore, it is possible to suppress the cohesive failure of the next first sealing part and the further development of the cracks in the sealing direction. Therefore, in the above-mentioned storage device, even if cracks occur in the resin part during the bonding between the sealing part of the shell part or the terminal part and the resin part, it is possible to suppress the cracks from developing in the sealing direction and the destruction of all the first sealing parts included in the sealing part, resulting in poor sealing.

[0010] Examples of the “electricity storage device” include secondary batteries such as lithium ion secondary batteries, sodium ion secondary batteries, and calcium ion secondary batteries, and capacitors such as lithium ion capacitors.

[0011] (2) According to the power storage device described in (1), the sealing portion may include three or more first sealing portions.

[0012] In the above-described power storage device, since the sealing portion includes three or more first sealing portions, it is possible to further suppress the occurrence of sealing failure due to the destruction of all the first sealing portions included in the sealing portion, compared with a case where there are two first sealing portions.

[0013] (3) According to the energy storage device described in (1) or (2), a plurality of the above-mentioned first sealing parts can be lined with nanocolumns with a height of more than 20 nm, in which particles derived from the metal forming the above-mentioned shell part or the above-mentioned terminal part are combined in a beaded shape to form a columnar shape, and the resin material forming the above-mentioned resin part is filled between these nanocolumns.

[0014] In the above power storage device, the first sealing portion is a nano-roughened surface of the above-mentioned nanocolumns, and the resin material is filled between the nanocolumns. Therefore, the sealing performance between the first sealing portion and the resin member can be made particularly good.

[0015] (4) In addition, another embodiment is a method for manufacturing an electrical storage device, the electrical storage device comprising: a shell member having an insertion hole and including a ring-shaped shell sealing portion surrounding the insertion hole; a terminal member inserted into the insertion hole of the shell member and including a ring-shaped terminal sealing portion located near the insertion hole; and a resin member that air-tightly bonds with the shell sealing portion of the shell member and the terminal sealing portion of the terminal member while insulating them from each other, and fixes the terminal member to the shell member, wherein at least any one of the shell sealing portion and the terminal sealing portion has: a plurality of first sealing portions arranged in a circumferential direction of the sealing portion A ring shape connected throughout the entire circumference, which causes cohesive failure when the connection with the above-mentioned resin component is about to be broken; and a second sealing portion, which is respectively arranged between the above-mentioned first sealing portions adjacent to each other in the width direction of the above-mentioned sealing portion, and is in a ring shape connected throughout the circumference of the above-mentioned sealing portion, which causes interfacial failure when the connection with the above-mentioned resin component is about to be broken, wherein the manufacturing method of the above-mentioned power storage device comprises: a sealing portion forming step, forming the above-mentioned sealing portion having a plurality of the above-mentioned first sealing portions and the above-mentioned second sealing portions on at least one of the above-mentioned shell component and the above-mentioned terminal component; and a resin forming step, after the above-mentioned sealing portion forming step, forming the above-mentioned resin component connected to the above-mentioned sealing portion.

[0016] In the manufacturing method of the above-mentioned power storage device, in the sealing portion forming step, a sealing portion including a plurality of first sealing portions and a second sealing portion can be formed on at least one of the case member and the terminal member. In addition, in the resin forming step, a resin member bonded to the sealing portion including the first sealing portion and the second sealing portion can be formed.

[0017] Among them, in the "resin forming process", as a method for forming a resin part, for example, there can be cited a method of forming (molding) a resin part joined to a shell sealing part and a terminal sealing part by insert molding using a shell part and a terminal part, a method of forming a resin part by applying a liquid resin material to the shell sealing part and the terminal sealing part and solidifying it, etc.

[0018] (5) According to the manufacturing method of the storage battery device described in (4), a plurality of the first sealing parts may be lined with nanocolumns having a height of more than 20 nm, which are formed by combining particles of the metal forming the shell part or the terminal part in a beaded shape to form a columnar shape, and the spaces between these nanocolumns are filled with a resin material forming the resin part. The sealing part forming step staggers the irradiation position to intermittently irradiate the sealing part with a pulse laser to form a plurality of the first sealing parts lined with the nanocolumns. The resin forming step forms the resin part while filling the resin material between the nanocolumns lined with the plurality of the first sealing parts.

[0019] In the above-mentioned method for manufacturing the electric storage device, since the first sealing part where the nano-pillars are arranged in a forest is formed by using a pulsed laser, the first sealing part where the nano-pillars are arranged in a forest can be easily formed in the sealing part. In addition, in the resin forming step, since the resin part is formed while the resin material is filled between the nano-pillars arranged in the first sealing part, a resin part having particularly good sealing performance with the first sealing part can be formed. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a perspective view of a battery according to an embodiment.

[0021] Figure 2 It is a partial cross-sectional view of the battery according to the embodiment along the battery height direction and the battery width direction.

[0022] Figure 3 It is a partial enlarged cross-sectional view of the vicinity of a case seal portion, a terminal seal portion, and a resin member in the battery according to the embodiment, taken along the battery height direction and the battery thickness direction.

[0023] Figure 4 The implementation method involves Figure 3A partial enlarged sectional view showing the vicinity of a plurality of first sealing portions and a plurality of second sealing portions of a terminal sealing portion in the partial enlarged sectional view of FIG.

[0024] Figure 5 The implementation method involves Figure 3 A partial enlarged sectional view showing the vicinity of a plurality of first sealing portions and a plurality of second sealing portions of the housing sealing portion in the partial enlarged sectional view of FIG.

[0025] Figure 6 This is a partially enlarged cross-sectional view showing nanocolumns standing in a forest in a first sealing portion according to an embodiment.

[0026] Figure 7 This is a flowchart of a method for manufacturing a battery according to an embodiment.

[0027] Figure 8 This is an explanatory diagram showing a state in which a plurality of bowl-shaped recesses and nanocolumns standing in a row in the bowl-shaped recesses are formed by scanning a pulse laser in a sealing portion forming step in relation to a method for manufacturing a battery according to an embodiment.

[0028] Fig.9A The present invention is an explanatory diagram of a resin forming step related to a method for manufacturing a battery according to an embodiment, and is an explanatory diagram showing a state in which positive and negative terminal members are respectively inserted into the insertion holes of a case cover member.

[0029] Fig. 9B This is an explanatory diagram of a resin forming step related to the battery manufacturing method according to the embodiment, and is an explanatory diagram showing a state where a pair of resin members are molded. DETAILED DESCRIPTION

[0030] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Figure 1 , a perspective view of a battery (an example of an electric storage device of the present invention) 1 according to the present embodiment is shown. Figure 2 A partial cross-sectional view of the battery 1 is shown in FIG. Figure 3 , a partial enlarged cross-sectional view of the vicinity of the terminal seal portion (an example of the seal portion of the present invention) 51, the case seal portion (an example of the seal portion of the present invention) 31, and the resin member 70 in the battery 1 is shown. Figure 4 FIG. 2 shows a partial enlarged cross-sectional view of the first sealing portion 52 and the second sealing portion 53 of the terminal sealing portion 51. Figure 5 FIG. 2 shows a partial enlarged cross-sectional view of the first sealing portion 32 and the second sealing portion 33 of the housing sealing portion 31. Hereinafter, the battery height direction AH, the battery width direction BH, and the battery thickness direction CH of the battery 1 are defined as Figure 1 as well as Figure 2The directions shown are used for illustration.

[0031] The battery 1 is a square (rectangular) and sealed lithium-ion secondary battery mounted on hybrid vehicles, plug-in hybrid vehicles, electric vehicles, and the like. The battery 1 is composed of a housing 10, an electrode body 40 housed in the housing 10, and positive and negative terminal members 50 fixed to the housing 10 by means of a resin member 70. The electrode body 40 is covered by a bag-shaped insulating retainer 7 composed of an insulating film in the housing 10. In addition, an electrolyte 5 is housed in the housing 10, a portion of the electrolyte 5 is impregnated in the electrode body 40, and the rest is stored on the bottom wall of the housing 10.

[0032] The housing 10 is made of metal (aluminum in the present embodiment) and is in the shape of a rectangular box. It is composed of a housing body part 20 and a rectangular plate-shaped housing cover part (an example of the housing part of the present invention) 30. The housing body part 20 is in the shape of a bottomed square cylinder having a rectangular opening 20c and contains an electrode body 40 inside. The housing cover part 30 blocks the opening 20c of the housing body part 20. The opening 20c of the housing body part 20 and the peripheral edge 30f of the housing cover part 30 are welded airtightly throughout the entire circumference. A safety valve 11 is provided in the housing cover part 30. The safety valve 11 breaks and opens when the internal pressure of the housing 10 exceeds the valve opening pressure. In addition, a liquid injection hole 30k is provided in the housing cover part 30, and the liquid injection hole 30k is airtightly sealed by a circular plate-shaped sealing part 12 made of aluminum.

[0033] The electrode body 40 is rectangular and stacked, and is formed by stacking a plurality of rectangular positive plates 41 and a plurality of rectangular negative plates 42 alternately in the battery thickness direction CH through rectangular separators 43 composed of a porous film made of resin. On one side BH1 of the battery width direction BH in the electrode body 40, the collector foils of each positive plate 41 overlap in the battery thickness direction CH to form a positive electrode collector 40c. The positive electrode collector 40c is conductively connected to the terminal member 50 of the positive electrode described later. In addition, on the other side BH2 of the battery width direction BH in the electrode body 40, the collector foils of each negative plate 42 overlap in the battery thickness direction CH to form a negative electrode collector 40d. The negative electrode collector 40d is conductively connected to the terminal member 50 of the negative electrode described later.

[0034] A rectangular insertion hole 30h penetrating the case cover member 30 is provided near the end portions on one side BH1 and the other side BH2 in the battery width direction BH of the case cover member 30. A positive terminal member 50 made of aluminum is inserted into the insertion hole 30h on the one side BH1, and the terminal member 50 is fixed to the case cover member 30 while being insulated from the case cover member 30 by the resin member 70. In addition, a negative terminal member 50 made of copper is inserted into the insertion hole 30h on the other side BH2, and the terminal member 50 is fixed to the case cover member 30 while being insulated from the case cover member 30 by the resin member 70.

[0035] The terminal component 50 is formed by stamping a metal plate (a positive electrode is an aluminum plate, and a negative electrode is a copper plate). The terminal component 50 is composed of a rectangular plate-shaped terminal top plate portion 50a and a terminal extension protrusion 50b. The terminal top plate portion 50a is located on the upper side AH1 of the battery height direction AH of the case cover component 30, and extends in the battery width direction BH and the battery thickness direction CH. The terminal extension protrusion 50b extends from the terminal top plate portion 50a to the lower side AH2 of the battery height direction AH. The terminal extension protrusion 50b is bent at the end of one side CH1 of the battery thickness direction CH of the terminal top plate portion 50a and extends to the lower side AH2, passes through the insertion hole 30h of the case cover component 30, and further penetrates the resin component 70 and extends to the lower side AH2. The positive terminal extension protrusion 50b is welded to the positive electrode collector 40c of the electrode body 40 at the front end of the lower side AH2. In addition, the negative electrode terminal extension projection 50 b is welded to the negative electrode current collecting portion 40 d of the electrode body 40 at the front end portion on the lower side AH2 .

[0036] The ring-shaped portion of the metal surface 50m of the terminal member 50 located near the insertion hole 30h is a terminal seal portion 51 (see FIG. 1 ) bonded to the resin member 70. Figure 3 as well as Figure 4 ). Specifically, the inner side surface of the surface of the terminal top plate portion 50a facing the lower side AH2 and the four side surfaces and the outer peripheral surface of the terminal extension protrusion 50b, which are located inside the resin component 70 on the upper side AH1, are the terminal sealing portion 51. The terminal sealing portion 51 is composed of a plurality of (four in this embodiment) first sealing portions 52 (52A, 52B, 52C, 52D), a plurality of (three in this embodiment) second sealing portions 53 (53A, 53B, 53C), and two third sealing portions 54 (54A, 54B), which are arranged along the extension protrusion direction of the terminal component 50 (the same direction as the battery height direction AH).

[0037] Specifically, each first sealing portion 52 is in the shape of a rectangular ring connected throughout the entire circumference IBH of the terminal sealing portion 51 (in this embodiment, along the circumference of the battery width direction BH and the battery thickness direction CH). The width dimension of each first sealing portion 52 is 360 μm or more (about 400 μm in this embodiment). These first sealing portions 52 are firmly bonded to the resin component 70 as described later, and when the bond between the first sealing portion 52 and the resin component 70 is to be broken, it becomes a cohesive failure (near the interface between the first sealing portion 52 and the resin component 70, cracks are generated inside the resin component 70 and the bond is broken).

[0038] Each first sealing portion 52 is subjected to a roughening treatment by pulse laser LC described later, and has a nano-roughened surface at the nanometer level. That is, the first sealing portion 52 is concave in a bowl or crater shape with a diameter Db (see Figure 8 A large number of bowl-shaped recesses 55 with a diameter of 30 to 300 μm (in this embodiment, the approximate diameter Db=80 μm in the positive terminal member 50 and the approximate diameter Db=75 μm in the negative terminal member 50) are arranged in a partially overlapping manner in the first sealing portion 52. In these bowl-shaped recesses 55, nanopillars 56 (see FIG. 1 ) with a height ha of 20 nm or more (in this embodiment, the approximate height ha=200 nm) are formed by combining particles 56p of the metal forming the terminal member 50 in a beaded manner and forming a columnar shape. Figure 6 ). The metal forming the positive terminal member 50 is aluminum, and the positive nanocolumn 56 is formed by particles 56p composed of aluminum and aluminum oxide. On the other hand, the metal forming the negative terminal member 50 is copper, and the negative nanocolumn 56 is formed by particles 56p composed of copper and copper oxide.

[0039] Each second sealing portion 53 is respectively arranged between the first sealing portions 52 adjacent to each other in the width direction (sealing direction) JBH of the terminal sealing portion 51 (in the present embodiment, the same direction as the battery height direction AH). Each second sealing portion 53 is in the shape of a rectangular ring connected throughout the entire circumference IBH of the terminal sealing portion 51. The dimension of each second sealing portion 53 in the width direction is 360 μm or more (about 400 μm in the present embodiment). As described later, these second sealing portions 53 are weakly bonded to the resin component 70, and when the bond between the second sealing portion 53 and the resin component 70 is to be broken, the interface is broken (they are peeled off at the interface between the second sealing portion 53 and the resin component 70 and the bond is broken). The above-mentioned bowl-shaped recess 55 and nanocolumn 56 are not formed in the second sealing portion 53 (the second sealing portion 53 has not been roughened by pulse laser LC and is not a nano-roughened surface).

[0040] The third sealing portion 54A of one of the two third sealing portions 54 is arranged at the upper side AH1 of the first sealing portion 52A located at the uppermost side AH1. In addition, the third sealing portion 54B of the other side is arranged at the lower side AH2 of the first sealing portion 52D located at the lowermost side AH2. These third sealing portions 54 are similar to the second sealing portion 53, and the bonding with the resin member 70 is weak, and when the bonding between the third sealing portion 54 and the resin member 70 is about to be broken, it becomes an interface failure. The above-mentioned bowl-shaped recess 55 and nanocolumn 56 are not formed in the third sealing portion 54.

[0041] Next, the housing seal portion 31 of the housing cover member 30 will be described (see Figure 3 , Figure 5 as well as Figure 6 ). The ring-shaped portions surrounding each insertion hole 30h in the metal surface 30m of the housing cover member 30 are housing seal portions 31 joined to the resin member 70. Specifically, the rectangular ring-shaped outer hole surrounding portion surrounding the insertion hole 30h in the outer main surface of the housing cover member 30 facing the upper side AH1 and the rectangular ring-shaped inner hole surrounding portion surrounding the insertion hole 30h in the inner main surface of the housing cover member 30 facing the lower side AH2, and the inner peripheral surface of the insertion hole 30h connecting them are the housing seal portions 31. The shell sealing portion 31 is composed of a plurality of (four in the present embodiment) first sealing portions 32 (32A, 32B, 32C, 32D), a plurality of (three in the present embodiment) second sealing portions 33 (33A, 33B, 33C), and two third sealing portions 34 (34A, 34B), and is arranged along the radial direction of the insertion hole 30h (along the battery width direction BH and the battery thickness direction CH).

[0042] Specifically, each first sealing portion 32 is in the shape of a rectangular ring connected throughout the entire circumference IAH of the housing sealing portion 31 (in this embodiment, along the battery width direction BH and the battery thickness direction CH). The width dimension of each first sealing portion 32 is 360 μm or more (about 400 μm in this embodiment). These first sealing portions 32 are firmly bonded to the resin member 70 as described later, and when the bond between the first sealing portion 32 and the resin member 70 is about to be broken, it becomes a cohesive failure.

[0043] Each first sealing portion 32 is subjected to a roughening treatment by pulse laser LC described later, and has a nano-roughened surface. That is, the first sealing portion 32 is concave in a bowl or crater shape with a diameter Db (see Figure 8A large number of bowl-shaped recesses 35 with a diameter of 30 to 300 μm (approximately 80 μm in this embodiment) are arranged in a partially overlapping manner in the first sealing portion 32. In these bowl-shaped recesses 35, nanopillars 36 (see FIG. 1 ) are formed by combining particles 36p of metal forming the housing cover member 30 in a beaded manner to form a columnar shape with a height ha of 20 nm or more (approximately 200 nm in this embodiment). Figure 6 ). The metal forming the housing cover member 30 is aluminum, and the nanorods 36 are formed of particles 36p consisting of aluminum and aluminum oxide.

[0044] Each second sealing portion 33 is respectively arranged between the first sealing portions 32 adjacent to each other in the width direction (sealing direction) JAH of the shell sealing portion 31 (in the present embodiment, the radial direction of the insertion hole 30h). Each second sealing portion 33 is in the shape of a rectangular ring connected throughout the entire circumference IAH of the shell sealing portion 31. The dimension of each second sealing portion 33 in the width direction is greater than 360 μm (in the present embodiment, about 400 μm). As described later, these second sealing portions 33 are weakly bonded to the resin component 70, and when the bond between the second sealing portion 33 and the resin component 70 is about to be broken, interface failure occurs. The above-mentioned bowl-shaped recess 35 and nanocolumn 36 are not formed in the second sealing portion 33.

[0045] One of the two third sealing portions 34, the third sealing portion 34A, is arranged on the radially outer side ( Figure 5 The third sealing portion 34B is arranged on the outer side of the first sealing portion 32A (left side in the middle). In addition, the third sealing portion 34B on the other side is arranged on the outer side of the first sealing portion 32D located on the radially outer side at the lower side AH2. These third sealing portions 34 are similar to the second sealing portions 33. The bonding with the resin component 70 is weak, and when the bonding between the third sealing portion 34 and the resin component 70 is about to be broken, it becomes an interface failure. The above-mentioned bowl-shaped recess 35 and nanocolumn 36 are not formed in the third sealing portion 34.

[0046] Next, the resin component 70 will be described. The resin component 70 is a component obtained by insert molding using a resin material 75 including a thermoplastic main resin (specifically polyphenylene sulfide (PPS)), a thermoplastic elastomer, and a filler (specifically a fibrous glass filler). Each resin component 70 insulates the case seal portion 31 of the case cover component 30 from the terminal seal portion 51 of the positive or negative terminal component 50, and is airtightly bonded to them, thereby fixing the terminal component 50 to the case cover component 30.

[0047] The resin component 70 is airtightly bonded to the annular terminal sealing portion 51 of the terminal component 50 over the entire circumference in the circumferential direction IBH. Specifically, the resin component 70 is airtightly bonded to the annular first sealing portion 52 (52A to 52D) over the entire circumference with a strong bonding force by filling the above-mentioned resin material 75 between the nanopillars 56 standing in the first sealing portion 52 (52A to 52D) in the terminal sealing portion 51. In addition, the resin component 70 is airtightly bonded to the annular second sealing portion 53 (53A to 53C) and the annular third sealing portion 54 (54A, 54B) in the terminal sealing portion 51 over the entire circumference with a weak bonding force. As a result, the terminal sealing portion 51 of the terminal component 50 and the resin component 70 are airtightly sealed in the width direction JBH of the terminal sealing portion 51.

[0048] In addition, the resin component 70 is airtightly bonded to the annular housing seal portion 31 of the housing cover component 30 over the entire circumference IAH. Specifically, the resin component 70 is airtightly bonded to the annular first seal portion 32 (32A to 32D) over the entire circumference with a strong bonding force by filling the above-mentioned resin material 75 between the nanopillars 36 respectively standing in the housing seal portion 31 and the first seal portion 32 (32A to 32D). In addition, the resin component 70 is airtightly bonded to the annular second seal portion 33 (33A to 33C) and the annular third seal portion 34 (34A, 34B) in the housing seal portion 31 over the entire circumference with a weak bonding force. As a result, the housing seal portion 31 of the housing cover component 30 and the resin component 70 are airtightly sealed in the width direction JAH of the housing seal portion 31.

[0049] In the battery 1 of the present embodiment, as described above, each of the case seal 31 and the terminal seal 51 is not firmly bonded to the resin member 70 in such a manner that cohesive failure occurs on the entire surface of these seals 31, 51 (the entire seal 31, 51 is not regarded as the first seal 32, 52), but the seal 31, 51 is formed to have a plurality of annular first seals 32, 52 that undergo cohesive failure and a plurality of annular second seals 33, 53 that are arranged between these first seals 32, 52 and undergo interface failure. Thus, even if cracks occur in the resin member 70 in one of the first seals 32, 52 during the manufacture and use of the battery 1, it is possible to prevent the cracks from extending to the other first seals 32, 52 and causing the failure of all the first seals 32, 52 included in the seal 31, 51.

[0050] That is, in consideration of the development of cracks, if cohesive failure occurs in a first sealing portion 32, 52 and cracks develop in the sealing directions JAH and JBH, interface failure is likely to occur in the second sealing portion 33, 53 adjacent to the first sealing portion 32, 52 because the bonding with the resin member 70 is weak. In the second sealing portion 33, 53, since cracks do not develop in the sealing directions JAH and JBH as they are, but also develop in the circumferential directions IAH and IBH, stress can be relieved by interface failure of the second sealing portion 33, 53. Therefore, cohesive failure can be prevented from occurring in the next first sealing portion 32, 52 and cracks from further developing in the sealing directions JAH and JBH. Therefore, in the battery 1, even if cracks occur in the resin component 70 during the bonding between the sealing portions 31, 51 of the shell cover component 30 and the terminal component 50 and the resin component 70, it is possible to suppress the cracks from developing in the sealing directions JAH, JBH and prevent the entire first sealing portion 32, 52 included in the sealing portion 31, 51 from being destroyed, thereby causing poor sealing.

[0051] Furthermore, in this embodiment, since the sealing portions 31, 51 of the shell cover component 30 and the terminal component 50 respectively have more than three first sealing portions 32, 52, compared with the case where there are two first sealing portions 32, 52, it is possible to further suppress the destruction of all the first sealing portions 32, 52 included in the sealing portions 31, 51 and the occurrence of poor sealing.

[0052] Furthermore, since the first sealing portions 32 and 52 of the housing cover member 30 and the terminal member 50 are nano-roughened surfaces with a forest of nano-pillars 36 and 56 , and the resin material 75 is filled between the forest of nano-pillars 36 and 56 , the sealing performance between the first sealing portions 32 and 52 and the resin member 70 can be particularly good.

[0053] Next, a method for manufacturing the battery 1 will be described (see Figure 7 ~Figure 9). First, prepare the housing cover member 30Z before roughening. The housing cover member 30Z before roughening can be obtained by stamping using an aluminum plate. In addition, prepare the terminal member 50Z before roughening. The terminal member 50Z before roughening can be obtained by stamping using a metal plate (a positive electrode is an aluminum plate, and a negative electrode is a copper plate).

[0054] Then, in the "terminal sealing portion forming step (sealing portion forming step) S1" (refer to Figure 7 ), the pulse laser LC is intermittently irradiated to the terminal sealing portion 51 in the metal surface 50m of the terminal member 50Z by staggering the irradiation position, so as to form a large number of bowl-shaped recesses 55 and four annular first sealing portions 52 (52A to 52D) arranged in a partially overlapping manner (refer to Figure 8On the other hand, the portion of the terminal sealing portion 51 that has not been roughened by the pulse laser LC becomes three annular second sealing portions 53 (53A to 53C) and two annular third sealing portions 54 (54A, 54B).

[0055] In this embodiment, the irradiation conditions of the positive laser are as follows: the wavelength is 1064nm, the peak output is 5kW, the pulse width is 150ns, the pitch pb is 75μm, and the spot diameter is 80μm. In addition, the irradiation conditions of the negative laser are as follows: the wavelength is 1064nm, the peak output is 20kW, the pulse width is 50ns, the pitch pb is 60μm, and the spot diameter is 75μm.

[0056] In the circular area of ​​the terminal sealing portion 51 irradiated with the pulse laser LC when viewed from above, the metal near the surface (aluminum at the positive electrode and copper at the negative electrode) is dissolved and then becomes vapor. Then, when the temperature of the vapor decreases, it becomes particles 56p (particles 56p of aluminum and aluminum oxide at the positive electrode and particles 56p of copper and copper oxide at the negative electrode) and accumulates in the bowl-shaped recess 55. By staggering the irradiation position and intermittently irradiating the terminal sealing portion 51 with the pulse laser LC, the particles 56p are accumulated in a beaded shape and combined into a columnar shape, forming a forest of nanocolumns 56 (see Figure 8 as well as Figure 6 ).

[0057] In addition, in the "housing sealing portion forming step (sealing portion forming step) S2" (refer to Figure 7 ), the pulse laser LC is intermittently irradiated to the housing seal portion 31 in the metal surface 30m of the housing cover member 30Z at staggered irradiation positions to form four annular first seal portions 32 (32A to 32D) with a large number of bowl-shaped recesses 35 partially overlapping each other (see Figure 8 In each bowl-shaped recess 35, aluminum and aluminum oxide particles 36p are stacked in a beaded pattern and connected to form a columnar nanocolumn 36 (see Figure 6 ). On the other hand, the portion of the shell sealing portion 31 that has not been roughened at the nanometer level by the pulse laser LC is formed into three annular second sealing portions 33 (33A to 33C) and two annular third sealing portions 34 (34A, 34B). The laser irradiation conditions are the same as those when the laser is irradiated to the positive terminal member 50 in the terminal sealing portion forming step S1.

[0058] Next, in the "resin forming step S3" (refer to Figure 7), a resin component 70 is formed to be joined to the sealing portions 31, 51 of the housing cover component 30 and the terminal component 50, respectively. In the present embodiment, in a state where the positive and negative terminal components 50 are respectively inserted into the insertion holes 30h of the housing cover component 30, a pair of resin components 70 are insert-molded using the above-mentioned resin material 75 (refer to FIG. 9 ).

[0059] Specifically, the resin forming step S3 is performed using a molding die (not shown) having an upper die and a lower die. First, the housing cover member 30 is arranged at a predetermined position of the lower die, and the positive and negative terminal members 50 (see FIG. 1 ) are respectively inserted into a pair of insertion holes 30h of the housing cover member 30. Fig.9A ). Then, the upper mold is moved toward the lower mold and the molding mold is closed. Next, the molten resin material 75 is injected into the two cavities of the molding mold. At this time, the resin material 75 is also filled between the nano-pillars 36 standing in the first sealing portion 32 of the housing cover member 30, and between the nano-pillars 56 standing in the first sealing portion 52 of the terminal member 50.

[0060] Furthermore, a resin member 70 is formed which is airtightly joined to the housing seal portion 31 of the housing cover member 30, namely, the first seal portion 32 (32A to 32D), the second seal portion 33 (33A to 33C), and the third seal portion 34 (34A, 34B) in the entire circumference in the circumferential direction IAH, and is airtightly joined to the terminal seal portion 51 of the terminal member 50, namely, the first seal portion 52 (52A to 52D), the second seal portion 53 (53A to 53C), and the third seal portion 54 (54A, 54B) in the entire circumference in the circumferential direction IBH (see Fig. 9B ). Then, the cover assembly 15 in which the positive and negative terminal members 50 are fixed to the case cover member 30 via the resin member 70 is taken out from the molding die.

[0061] Since the first sealing parts 32 and 52 of the sealing parts 31 and 51 are nano-roughened surfaces and the resin material 75 is filled between the forested nano-pillars 36 and 56, they are firmly bonded to the resin member 70. Therefore, when the bonding between the first sealing parts 32 and 52 and the resin member 70 is about to be broken, it becomes cohesive failure. On the other hand, since the second sealing parts 33 and 53 and the third sealing parts 34 and 54 of the sealing parts 31 and 51 are not nano-roughened surfaces, the bonding with the resin member 70 is weak, so when the bonding with the resin member 70 is about to be broken, it becomes interfacial failure.

[0062] Next, in the "electrode body connection step S4" (see Figure 7), an electrode body 40 obtained by stacking a positive electrode plate 41, a negative electrode plate 42 and a separator 43 is prepared, and a terminal extension protrusion 50b of the positive terminal member 50 in the above-mentioned cap assembly 15 is welded to the positive electrode collector 40c of the electrode body 40 (refer to Figure 2 as well as Figure 1 ). In addition, the terminal extension protrusion 50b of the negative terminal member 50 in the cap assembly 15 is welded to the negative electrode current collecting portion 40d of the electrode body 40. Then, the electrode body 40 is wrapped with a bag-shaped insulating holder 7.

[0063] Next, in the "electrode body storage / case forming step S5", the case body 20 is prepared, the electrode body 40 covered by the insulating holder 7 is inserted into the case body 20, and the opening 20c of the case body 20 is sealed with the case cover 30. Furthermore, the opening 20c of the case body 20 and the peripheral edge 30f of the case cover 30 are laser welded airtightly around the entire circumference to form the case 10 that stores the electrode body 40 inside.

[0064] Next, in the "liquid injection / sealing step S6", the electrolyte 5 is injected into the case 10 through the liquid injection hole 30k, so that the electrolyte 5 is impregnated into the electrode body 40. Then, the liquid injection hole 30k is covered from the outside with the sealing member 12, and the sealing member 12 and the case 10 are laser welded airtightly.

[0065] Next, in the "initial charging / aging step S7", the battery 1 is connected to a charging device (not shown) to perform initial charging on the battery 1. The initially charged battery 1 is then left to stand for a predetermined time to age the battery 1. In this way, the battery 1 is completed.

[0066] In the manufacturing method of the battery 1 of the present embodiment, in the sealing portion forming steps S1 and S2, the sealing portions 31 and 51 including the plurality of first sealing portions 32 and 52 and the plurality of second sealing portions 33 and 53 can be formed on the case cover member 30 and the terminal member 50. In addition, in the resin forming step S3, the resin member 70 bonded to the sealing portions 31 and 51 including the first sealing portions 32 and 52 and the second sealing portions 33 and 53 can be formed.

[0067] Furthermore, in the present embodiment, since the first sealing portions 32 and 52 where the nanopillars 36 and 56 are arranged in a forest are formed by using the pulse laser LC, the first sealing portions 32 and 52 where the nanopillars 36 and 56 are arranged in a forest can be easily formed in the sealing portions 31 and 51. In addition, in the resin forming step S3, since the resin member 70 is formed while the resin material 75 is filled between the nanopillars 36 and 56 arranged in the first sealing portions 32 and 52, the resin member 70 having particularly good sealing properties with the first sealing portions 32 and 52 can be formed.

[0068] As mentioned above, although this invention was demonstrated combining embodiment, this invention is not limited to embodiment, It is a matter of course that it can be applied with appropriate modification within the range which does not deviate from the summary.

[0069] For example, in the embodiment, the first sealing part 32, 52 of the sealing part 31, 51 is made into a nano-roughened surface with a forest of nano-pillars 36, 56, so that the first sealing part 32, 52 and the resin part 70 are firmly bonded in a manner of cohesive failure, but the present invention is not limited thereto. It is also possible to make the first sealing part 32, 52 into a roughened surface by other roughening treatments, such as physical roughening treatments such as shot peening, filing, and thermal spraying, and chemical roughening treatments such as anodizing treatment, so that the first sealing part 32, 52 and the resin part 70 are firmly bonded in a manner of cohesive failure.

[0070] Description of reference numerals:

[0071] 1…battery (electrical storage device); 10…housing; 30…housing cover member (housing member); 30h…insertion hole; 31…housing seal (seal) (of housing cover member); 32, 32A, 32B, 32C, 32D…first seal (of housing seal); 33, 33A, 33B, 33C…second seal (of housing seal); 34, 34A, 34B…third seal (of housing seal); 36…nanopillars (of housing cover member); 36p…particles (derived from metal forming housing cover member); 40…electrode body; 50…terminal member (metal member); 51…terminal seal (seal) (of terminal member); 52, 52A, 52B, 52C, 52D…first seal (of terminal seal) Sealing part; 53, 53A, 53B, 53C… (second sealing part of the terminal sealing part); 54, 54A, 54B… (third sealing part of the terminal sealing part); 56… (nanopillar of the terminal component); 56p… (particles derived from the metal forming the terminal component); 70… resin component; 75… resin material; IAH… (circumferential direction of the shell sealing part); IBH… (circumferential direction of the terminal sealing part); JAH… (width direction of the shell sealing part (sealing direction); JBH… (width direction of the terminal sealing part (sealing direction); ha… (nanopillar) height; LC… pulsed laser; S1… terminal sealing part forming process (sealing part forming process); S2… shell sealing part forming process (sealing part forming process); S3… resin forming process.

Claims

1. An electric storage device comprising: A housing member having an insertion hole and including an annular housing seal portion surrounding the insertion hole; a terminal member inserted into the insertion hole of the housing member and including a terminal sealing portion with a ring shape located near the insertion hole; as well as a resin member which is airtightly joined to the housing member while insulating the housing seal portion of the housing member and the terminal seal portion of the terminal member, and fixes the terminal member to the housing member, It is characterized in that At least one of the housing seal and the terminal seal has: The plurality of first sealing portions are in a ring shape connected over the entire circumference of the sealing portion, and when the bonding with the resin member is about to be broken, the bonding is cohesively broken; and The second sealing portion is disposed between the first sealing portions adjacent to each other in the width direction of the sealing portion, and is annularly connected over the entire circumference of the sealing portion, and causes interface failure when the bond with the resin member is about to fail.

2. The power storage device according to claim 1, characterized in that The sealing portion includes three or more first sealing portions.

3. The power storage device according to claim 1 or 2, characterized in that: The first sealing portions are formed of a plurality of nanocolumns having a height of 20 nm or more, in which particles derived from the metal forming the case member or the terminal member are connected in a beaded manner to form a columnar shape, and the resin material forming the resin member is filled between the nanocolumns.

4. A method for manufacturing an electric storage device, the electric storage device comprising: A housing member having an insertion hole and including an annular housing seal portion surrounding the insertion hole; a terminal member inserted into the insertion hole of the housing member and including a terminal sealing portion with a ring shape located near the insertion hole; as well as a resin member which is airtightly joined to the housing member while insulating the housing seal portion of the housing member and the terminal seal portion of the terminal member, and fixes the terminal member to the housing member, At least one of the housing seal and the terminal seal has: The plurality of first sealing portions are in a ring shape connected over the entire circumference of the sealing portion, and when the bonding with the resin member is about to be broken, the bonding is cohesively broken; and The second sealing portion is disposed between the first sealing portions adjacent to each other in the width direction of the sealing portion, and is in a ring shape connected to the entire circumference of the sealing portion, and causes interface failure when the bond with the resin member is about to be broken. The method for manufacturing the power storage device is characterized in that: a sealing portion forming step of forming the sealing portion having a plurality of the first sealing portions and the second sealing portions on at least one of the housing member and the terminal member; and The resin forming step is a step of forming the resin member bonded to the sealing portion after the sealing portion forming step.

5. The method for manufacturing an electric storage device according to claim 4, wherein: The first sealing portion has a plurality of nanocolumns with a height of 20 nm or more formed by combining particles of metal forming the housing member or the terminal member in a beaded manner to form a columnar shape, and the resin material forming the resin member is filled between the nanocolumns. The sealing portion forming step intermittently irradiates the sealing portion with pulse laser light by shifting the irradiation position, thereby forming a plurality of the first sealing portions having the nanocolumns standing in a forest. The resin forming step forms the resin member while filling the resin material between the nanocolumns standing in a forest in the plurality of first sealing portions.

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