Power storage device and method of manufacturing the power storage device

Abstract

To provide: a power storage device or the like that uses a metal case member with a resin protrusion firmly and integrally installed on the inner side of the case member and that can prevent a broken piece of an electrode body from blocking a safety valve from inside even if the electrode body breaks, thus allowing the safety valve to function properly.SOLUTION: A power storage device 1 includes a safety valve 30 in a case member 21 made of metal. The case member 21 has a valve periphery roughened portion 24 around the safety valve 30 on a case inner surface 23. The power storage device further includes a blockage preventing resin protrusion 40 that is a protrusion made of resin, joined to the valve periphery roughened portion 24 and protruding to the inside EH, the blockage preventing resin protrusion preventing a broken piece of an electrode body 50 from blocking the safety valve 30. Nanocolumns 26 stand numerously on the valve periphery roughened portion 24, and the blockage preventing resin protrusion 40 is joined to the valve periphery roughened portion 24 such that a resin material 45 fills gaps between the nanocolumns 26 standing numerously.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a power storage device in which a safety valve is provided in a case member constituting a case, and a method for manufacturing the power storage device.

Background Art

[0002] As a power storage device, a battery is known in which an electrode body is housed in a metal case and a safety valve is provided in a case member forming the case. The safety valve opens when the internal pressure of the case exceeds the opening pressure and releases gas to the outside. For example, such a battery is disclosed in Patent Document 1 (see FIGS. 1 and 2 of Patent Document 1, etc.).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, when a nail puncture test is performed on such a battery, the temperature of the electrode body may rise rapidly and a part of the electrode body may break. Further, if the broken piece of the electrode body moves to the vicinity of the safety valve and blocks the safety valve from the inside, there is a risk that the opening of the safety valve may be hindered or the release of gas through the opened safety valve may be hindered.

[0005] Therefore, in order to solve this problem, the inventor considered providing a convex portion protruding inward integrally with the case member around the safety valve on the inner surface of the case of the case member provided with the safety valve, so as to suppress the broken piece of the electrode body from blocking the safety valve from the inside. However, (1) when the case member is press - formed and a part of the case member is made into a metal convex part, especially when the thickness of the case member is increased, if an attempt is made to increase the height or size of the convex part, the metal convex part may not be formed into the desired shape by press - forming. Also, during pressing, the case member is likely to be distorted and deformed, and problems such as leakage are likely to occur when the case is sealed later. (2) On the other hand, when welding a separately formed metal convex part to the case member, there are problems such as the case member being easily deformed during welding, and it also incurs high costs. (3) Or, forming a case member having a metal convex part by casting is not only low in productivity but also costly.

[0006] The present invention has been made in view of such a situation, and instead of a metal convex part, a case member in which a resin convex part is firmly integrally provided inside a metal case member is used. Even when the electrode body breaks, it is possible to suppress the broken pieces of the electrode body from blocking the safety valve from the inside, and a power storage device in which the safety valve functions properly, and a method for manufacturing the power storage device are provided.

Means for Solving the Problems

[0007] (1) One aspect of the present invention for solving the above problems is a power storage device including a case having a metal case member, a safety valve provided on the case member, and an electrode body housed in the case, wherein the case member has a roughened valve - surrounding roughened part around the safety valve among the inner surfaces of the case located inside, and further includes a resin convex part that joins to the roughened valve - surrounding roughened part on the inner surface of the case and protrudes inward, and when the electrode body breaks, the resin convex part suppresses the safety valve from being blocked from the inside by the broken pieces of the electrode body. The valve - surrounding roughened part has nanocolumns with a height of 50 nm or more, in which particles derived from the metal forming the case member are connected in a bead - like manner to form a columnar shape and stand upright. The resin convex part for blocking suppression is filled with a resin material forming the resin convex part for blocking suppression between the standing nanocolumns and joined to the roughened valve - surrounding roughened part.

[0008] In the above-described power storage device, the above-described blockage suppression resin convex portions are provided around the safety valve on the inner surface of the case of the case member. Therefore, even when the electrode body breaks in a nail penetration test or the like, it is possible to suppress the broken pieces of the electrode body from blocking the safety valve from the inside, the safety valve can open appropriately, and the gas can be appropriately released to the outside through the opened safety valve. Further, on the inner surface of the case of the case member, a valve peripheral roughened portion at the nano level (nano order) where the above-described nano pillars stand is provided, a resin material is filled between the standing nano pillars, and the blockage suppression resin convex portions are joined to the valve peripheral roughened portion. Therefore, the bonding strength between the case member and the blockage suppression resin convex portions can be increased.

[0009] Note that examples of the "power 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. The "safety valve" may be a non-return type safety valve that breaks and opens itself when the internal pressure of the case exceeds the opening pressure, or a return type safety valve that opens when the internal pressure of the case exceeds the opening pressure and closes when the internal pressure of the case falls below the opening pressure. The safety valve may also be a temperature release type safety valve that opens when the safety valve exceeds a predetermined temperature. As the form of the "blockage suppression resin convex portion", when the case member extends in the longitudinal direction, a pair of blockage suppression resin convex portions are provided on both sides in the longitudinal direction among the periphery of the safety valve, or a pair of blockage suppression resin convex portions are provided on both sides in the short direction among the periphery of the safety valve. Examples of the form of the blockage suppression resin convex portion also include a form in which a plurality of blockage suppression resin convex portions are provided around the safety valve so as to surround the entire safety valve.

[0010] (2) Another aspect includes a case having a metal case member, a safety valve provided on the case member, and an electrode body housed in the case. The case member has a roughened valve-peripheral roughened portion around the safety valve among the inner case inner surfaces located inside. Further provided is a resin convex portion that is joined to the valve-peripheral roughened portion of the case inner surface and protrudes inward, and is a blockage suppression resin convex portion that suppresses the safety valve from being blocked from the inside by fragments of the electrode body when the electrode body breaks. The valve-peripheral roughened portion has nanocolumns with a height of 50 nm or more formed by particles derived from the metal forming the case member being connected in a bead-like manner and becoming columnar. The blockage suppression resin convex portion is formed by filling a resin material forming the blockage suppression resin convex portion between the standing nanocolumns and joining to the valve-peripheral roughened portion. A method for manufacturing a power storage device, comprising: a case roughening step of intermittently irradiating the inner surface of the case member of the case with pulsed laser light while shifting the irradiation position to form the valve-peripheral roughened portion where the nanocolumns stand; and a resin molding step of molding the blockage suppression resin convex portion while filling the resin material between the standing nanocolumns of the valve-peripheral roughened portion.

[0011] In the method for manufacturing the above-described power storage device, in the case roughening step, the inner surface of the case member of the case is irradiated with pulsed laser light as described above to form a valve-peripheral roughened portion at the nanolevel where nanocolumns stand, so that the valve-peripheral roughened portion can be easily provided on the inner surface of the case. Then, in the resin molding step, the blockage suppression resin convex portion is molded while filling the resin material between the standing nanocolumns of this valve-peripheral roughened portion, so that the blockage suppression resin convex portion firmly joined to the valve-peripheral roughened portion can be provided.

[0012] (3) Furthermore, it is a method for manufacturing the power storage device according to (2), wherein the case member has an insertion hole, and a terminal member inserted into the insertion hole of the case member, and while insulating between the case member and the terminal member, joins them, and further includes a terminal resin member that fixes the terminal member to the case member, and the resin molding step is to mold the terminal resin member that joins the case member and the terminal member in a state where the terminal member is inserted into the insertion hole of the case member, and at the same time, mold the closing suppression resin convex portion that joins the case member, which is a good method for manufacturing the power storage device.

[0013] In a power storage device including a terminal resin member that fixes a terminal member to a case member, the terminal resin member and the closing suppression resin convex portion can be molded separately. On the other hand, in the above-described method for manufacturing a power storage device, since the terminal resin member and the closing suppression resin convex portion are molded at once, the terminal resin member and the closing suppression resin convex portion can be provided easily and inexpensively. Note that the terminal resin member and the closing suppression resin convex portion may be molded using the same resin material, or may be molded using different resin materials respectively.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Modes for Carrying Out the Invention

[0015] (Embodiment 1) Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. A perspective view of the battery (power storage device) 1 of the present Embodiment 1 is shown in FIG. 1, and a partial cross-sectional view of the battery 1 is shown in FIG. 2. Further, a plan view of the vicinity of the safety valve 30 of the battery 1 as viewed from the inside EH is shown in FIG. 3, and a cross-sectional view taken along the line A-A in FIG. 3 is shown in FIG. 4. Further, a partially enlarged cross-sectional view of the joint portion between the valve peripheral roughened portion 24 and the closing suppression resin protrusion 40 on the inner case surface 23 of the case lid member 21 is shown in FIG. 5. Hereinafter, the battery height direction AH, the battery width direction BH, and the battery thickness direction CH of the battery 1 are defined as the directions shown in FIGS. 1 and 2 for explanation.

[0016] The battery 1 is a rectangular (cuboid-shaped) and sealed lithium-ion secondary battery mounted on vehicles such as hybrid cars, plug-in hybrid cars, and electric vehicles. This battery 1 is composed of a metal case 10 provided with a safety valve 30, an electrode body 50 and an electrolytic solution 5 housed in the case 10, and positive and negative terminal members 60 fixed to the case 10 via terminal resin members 70 respectively. The electrode body 50 is covered by an insulating holder 7 inside the case 10. This insulating holder 7 is made of an insulating film and is in a bag shape that opens upward AH1 in the battery height direction AH.

[0017] Among these, the electrode body 50 is cuboid-shaped and laminated, and is formed by alternately laminating a plurality of rectangular positive electrode plates 51 and a plurality of rectangular negative electrode plates 52 in the battery thickness direction CH via a rectangular separator 53 made of a resin porous film. On one side BH1 in the battery width direction BH of the electrode body 50, the current collector foils of the respective positive electrode plates 51 overlap in the battery thickness direction CH to form a positive electrode current collector portion 50c. The positive terminal member 60 of the positive electrode is conductively connected to this positive electrode current collector portion 50c. Also, on the other side BH2 in the battery width direction BH of the electrode body 50, the current collector foils of the respective negative electrode plates 52 overlap in the battery thickness direction CH to form a negative electrode current collector portion 50d. The negative terminal member 60 of the negative electrode is conductively connected to this negative electrode current collector portion 50d.

[0018] The case 10 is a cuboid box shape made of metal (aluminum in this Embodiment 1), is a bottomed rectangular tube shape having a rectangular opening 11c, and is composed of a case body member 11 that houses the electrode body 50 inside and a rectangular plate-shaped case lid member 21 that closes the opening 11c of the case body member 11. In this Embodiment 1, the case lid member 21 corresponds to the aforementioned "case member", and the case lid member 21 has two main surfaces, that is, a case outer surface 22 facing the outside DH (upper side AH1) and a case inner surface 23 facing the inside EH (lower side AH2 in the battery height direction AH). The opening 11c of the case body member 11 and the peripheral edge portion 21f of the case lid member 21 are hermetically welded over the entire circumference. A liquid injection hole 21k is provided in the case lid member 21, and this liquid injection hole 21k is hermetically sealed by a disk-shaped sealing member 15 made of aluminum.

[0019] The safety valve 30 is integrally formed with the case lid member 21 in the case 10 (a part of the case lid member 21 serves as the safety valve 30). This safety valve 30 has an oval shape in plan view (oval when viewed from the upper side AH1) and is in the form of a plate thinner than the thickness of the case lid member 21. On the outer side DH (upper side AH1), a breaking portion 31 formed by a V-shaped groove is formed in a predetermined shape. The dimension of the safety valve 30 in the longitudinal direction (battery width direction BH) is 15 mm, and the dimension in the short direction (battery thickness direction CH) is 5 mm. The safety valve 30 opens when the internal pressure of the case 10 exceeds the opening pressure, and the breaking portion 31 breaks. Then, the gas inside the case 10 is discharged to the outside of the case 10 through the broken safety valve 30.

[0020] Among the inner case surfaces 23 of the case lid member 21, a blocking suppression resin convex portion 40 is joined around the safety valve 30 (see FIGS. 3, 4, and 2). Specifically, the inner case surface 23 of the case lid member 21 has a pair of roughened valve surrounding roughened portions 24 around the safety valve 30. These valve surrounding roughened portions 24 are provided on one side BH1 and the other side BH2 in the longitudinal direction (battery width direction BH) of the case lid member 21 around the safety valve 30 on the inner case surface 23, generally extending in the short direction (battery thickness direction CH) of the case lid member 21.

[0021] Each valve surrounding roughened portion 24 is subjected to a roughening process by a pulse laser beam LB described later and is made into a nano-level nano-roughened portion. Specifically, in the valve surrounding roughened portion 24, a large number of bowl-shaped recesses 25 with a diameter Da of 30 to 300 μm (generally Da = 80 μm in the first embodiment) recessed in a bowl shape are arranged side by side with partial overlap (see FIG. 7). In these bowl-shaped recesses 25, nano-columns 26 with a height ha of 50 nm or more (generally ha = 200 nm in the first embodiment) in which particles 26p derived from the metal forming the case lid member 21 are connected in a bead chain shape and become columnar stand upright (see FIGS. 5 and 7). The metal forming the case lid member 21 is aluminum as described above, and the nano-columns 26 are made of particles 26p composed of aluminum and aluminum oxide.

[0022] On a pair of valve-peripheral roughened portions 24 on the inner surface 23 of the case, resin-made convex portions that protrude toward the inner EH, i.e., blockage-suppressing resin convex portions 40, are joined respectively. That is, the two blockage-suppressing resin convex portions 40 extend generally in the short-side direction (battery thickness direction CH) of the case lid member 21 on one side BH1 and the other side BH2 in the longitudinal direction (battery width direction BH) of the case lid member 21 among the periphery of the safety valve 30, and protrude toward the inner EH respectively. By providing such blockage-suppressing resin convex portions 40, even when a part of the electrode body 50 is broken and the broken pieces of the electrode body 50 move to the vicinity of the safety valve 30, the blockage-suppressing resin convex portions 40 come into contact with the pieces of the electrode body 50, thereby suppressing the pieces of the electrode body 50 from blocking the safety valve 30 from the inner EH to the outer DH.

[0023] The height hb of the blockage-suppressing resin convex portion 40 is preferably in the range of 1.0 to 5.0 mm, and in the first embodiment, the height hb = 2.0 mm. By making the height hb of the blockage-suppressing resin convex portion 40 higher than 1.0 mm (hb ≧ 1.0 mm), it is possible to more effectively suppress the pieces of the electrode body 50 from blocking the safety valve 30. On the other hand, by suppressing the height hb of the blockage-suppressing resin convex portion 40 to 5.0 mm or less (hb ≦ 5.0 mm), the distance from the inner surface 23 of the case to the electrode body 50 is shortened (the space is reduced), and a large electrode body 50 can be accommodated in the case 10. For this reason, the battery capacity per unit volume of the battery 1 can be increased.

[0024] The blockage-suppressing resin convex portion 40 is made of a resin material 45 containing a thermoplastic main resin (polyphenylene sulfide (PPS) in the first embodiment), a thermoplastic elastomer (thermoplastic polyurethane elastomer in the first embodiment), and a filler (fibrous glass filler in the first embodiment). The blockage-suppressing resin convex portion 40 is formed by filling the resin material 45 between the nano-columns 26 standing on the valve-peripheral roughened portion 24 of the inner surface 23 of the case and is joined to the valve-peripheral roughened portion 24 with a strong bonding force.

[0025] Next, the relationship between the case lid member 21, the terminal member 60, and the terminal resin member 70 will be described (see FIGS. 1 and 2). In the case lid member 21, rectangular insertion holes 21h are provided near the ends on one side BH1 and the other side BH2 in the battery width direction BH, respectively. Inside the insertion hole 21h on one side BH1, a positive terminal member 60 made of aluminum is inserted, and the positive terminal resin member 70 insulates between the case lid member 21 and this terminal member 60, and is hermetically and firmly joined to the case lid member 21 and the terminal member 60, fixing the terminal member 60 to the case lid member 21. Inside the insertion hole 21h on the other side BH2, a negative terminal member 60 made of copper is inserted, and the negative terminal resin member 70 insulates between the case lid member 21 and this terminal member 60, and is hermetically and firmly joined to the case lid member 21 and the terminal member 60, fixing the terminal member 60 to the case lid member 21. The positive and negative terminal members 60 have the same form, and the positive and negative terminal resin members 70 also have the same form, so they will be described together below.

[0026] The terminal member 60 is formed by pressing a metal plate (aluminum plate for the positive electrode and copper plate for the negative electrode). The terminal member 60 is located outside the case lid member 21 (upper side AH1), and includes a rectangular terminal top plate portion 60a that extends in the battery width direction BH and the battery thickness direction CH, and a terminal extension portion 60b that extends from this terminal top plate portion 60a to the inside EH (lower side AH2) of the case lid member 21. The terminal extension portion 60b bends at the end on one side CH1 in the battery thickness direction CH of the terminal top plate portion 60a and extends to the lower side AH2, passes through the insertion hole 21h of the case lid member 21, and further penetrates the terminal resin member 70 and extends to the lower side AH2. The positive terminal extension portion 60b is welded to the positive current collector portion 50c of the electrode body 50 at the tip of the lower side AH2. On the other hand, the negative terminal extension portion 60b is welded to the negative current collector portion 50d of the electrode body 50 at the tip of the lower side AH2.

[0027] Among the terminal surfaces 61 of the terminal member 60, a terminal resin member 70 is joined in the vicinity of the insertion hole 21h. Specifically, the terminal surface 61 has a roughened terminal roughened portion 62 in the vicinity of the insertion hole 21h. This terminal roughened portion 62 is a nano-roughened portion at the nano level, similar to the valve peripheral roughened portion 24 of the case lid member 21 described above. That is, a large number of bowl-shaped recesses 63 are arranged in the terminal roughened portion 62 (see Fig. 7), and in each bowl-shaped recess 63, nano-columns 64 with a height ha of 50 nm or more (in the present Embodiment 1, the height ha is generally 200 nm), in which particles 64p derived from the metal forming the terminal member 60 are connected in a bead-like manner and form a columnar shape, stand upright (see Figs. 5 and 7). The metal forming the positive terminal member 60 is aluminum as described above, and the positive nano-columns 64 are made of particles 64p composed of aluminum and aluminum oxide. On the other hand, the metal forming the negative terminal member 60 is copper as described above, and the negative nano-columns 64 are made of particles 64p composed of copper and copper oxide.

[0028] Also, in the case lid member 21, a terminal resin member 70 is joined in the vicinity of the insertion hole 21h. Specifically, the case lid member 21 has a roughened portion near the hole 27 that is roughened in the vicinity of the insertion hole 21h. This roughened portion near the hole 27 is a nano-roughened portion at the nano level, similar to the valve peripheral roughened portion 24 of the case lid member 21 and the terminal roughened portion 62 of the terminal member 60. That is, the roughened portion near the hole 27 has a large number of bowl-shaped recesses 28 (see Fig. 7), and in each bowl-shaped recess 28, nano-columns 29 with a height ha of 50 nm or more (in the present Embodiment 1, the height ha is generally 200 nm), in which particles 29p derived from the metal forming the case lid member 21 (specifically, aluminum) are combined and form a columnar shape, stand upright (see Figs. 5 and 7).

[0029] The terminal resin member 70 is made of a resin material 75 that includes a thermoplastic main resin (perfluoroalkoxy alkane (PFA) in the first embodiment), a thermoplastic elastomer (thermoplastic polyurethane elastomer in the first embodiment), and a filler (fibrous glass filler in the first embodiment), which is different from the resin material 45 that forms the closing prevention resin convex portion 40. This terminal resin member 70 has the above-described resin material 75 filled between the nano-columns 64 standing upright in the terminal roughened portion 62 of the terminal member 60, and is hermetically joined to the terminal roughened portion 62 with a strong bonding force. Also, the resin material 75 is filled between the nano-columns 29 standing upright in the roughened portion 27 near the hole of the case lid member 21, and is hermetically joined to the roughened portion 27 near the hole with a strong bonding force.

[0030] In the battery 1 of the first embodiment, a closing prevention resin convex portion 40 is provided around the safety valve 30 on the inner case surface 23 of the case lid member 21. Therefore, even if the electrode body 50 breaks in a nail penetration test or the like, it is possible to prevent the broken pieces of the electrode body 50 from blocking the safety valve 30 from the inner side EH to the outer side DH, and the safety valve 30 can open appropriately, and the gas can be appropriately discharged to the outside through the opened safety valve 30. Further, a nano-level roughened portion 24 around the valve where nano-columns 26 stand upright is provided on the inner case surface 23 of the case lid member 21, and the resin material 45 is filled between the standing nano-columns 26, and the closing prevention resin convex portion 40 is joined to the roughened portion 24 around the valve. Therefore, the bonding strength between the case lid member 21 and the closing prevention resin convex portion 40 can be increased.

[0031] Next, the manufacturing method of the battery 1 will be described (see FIGS. 6 to 9). First, a case lid member 21Z before roughening is prepared. The case lid member 21Z before roughening is obtained by press-working an aluminum plate. Also, by this press-working, the safety valve 30 is also formed on the case lid member 21Z. Further, a terminal member 60Z before roughening is prepared. The terminal member 60Z before roughening is obtained by press-working a metal plate (aluminum plate for the positive electrode and copper plate for the negative electrode).

[0032] Then, in the case roughening step S1 (see FIG. 6), the pulse laser beam LB is intermittently irradiated at a predetermined position around the safety valve 30 on the inner surface 23 of the case of the above-described case lid member 21Z while shifting the irradiation position, so that a pair of valve surrounding roughened portions 24 in which a large number of bowl-shaped recesses 25 are arranged while partially overlapping are formed (see FIG. 7). Further, at predetermined positions in the vicinity of the pair of insertion holes 21h of the case lid member 21Z, the pulse laser beam LB is intermittently irradiated while shifting the irradiation position, so that a pair of hole vicinity roughened portions 27 in which a large number of bowl-shaped recesses 28 are arranged while partially overlapping are formed. The laser irradiation conditions were a wavelength of 1064 nm, a peak output of 5 kW, a pulse width of 150 ns, a pitch pb of 75 μm, and a spot diameter of 80 μm.

[0033] At the portion of the case lid member 21Z irradiated with the pulse laser beam LB, the metal (specifically, aluminum) forming the vicinity of the surface is melted and further becomes vapor. Then, when the temperature of the vapor decreases, it becomes particles 26p, 29p of aluminum and aluminum oxide and deposits in the bowl-shaped recesses 25, 28. By intermittently irradiating the pulse laser beam LB while shifting the irradiation position, the particles 26p, 29p are deposited and bonded in a bead-like manner to form a columnar shape, and standing nano-columns 26, 29 are formed (see FIGS. 7 and 5).

[0034] Separately, in the terminal roughening step S2 (see FIG. 6), the pulse laser beam LB is intermittently irradiated at a predetermined position of the positive and negative terminal members 60Z described above while shifting the irradiation position, so that a terminal roughened portion 62 in which a large number of bowl-shaped recesses 63 are arranged while partially overlapping is formed (see FIG. 7). In each bowl-shaped recess 63, nano-columns 64 in which particles 64p (aluminum and aluminum oxide particles for the positive electrode, copper and copper oxide particles for the negative electrode) are deposited and bonded in a bead-like manner to form a columnar shape stand (see FIGS. 7 and 5). The laser irradiation conditions for the positive terminal member 60 were the same as those in the case roughening step S1. On the other hand, the laser irradiation conditions for the negative terminal member 60 were a wavelength of 1064 nm, a peak output of 20 kW, a pulse width of 50 ns, a pitch pb of 60 μm, and a spot diameter of 75 μm.

[0035] Next, in the resin molding step S3 (see FIG. 6), with the positive and negative terminal members 60 inserted into the pair of insertion holes 21h of the case lid member 21, a pair of terminal resin members 70 joined to the case lid member 21 and the terminal members 60 are molded, and a pair of blockage suppression resin protrusions 40 joined to the case lid member 21 are molded (see FIGS. 8 and 9). Specifically, this resin molding step S3 is performed using a molding die (not shown) having an upper die and a lower die. First, the case lid member 21 is placed at a predetermined position of the lower die, and the positive and negative terminal members 60 are respectively inserted into the pair of insertion holes 21h of the case lid member 21 (see FIG. 8). Then, the upper die is moved toward the lower die to close the molding die.

[0036] Next, the molten resin in which the resin material 75 is melted is injected into each of the two cavities for molding the terminal resin members 70, and the molten resin in which the resin material 45 is melted is injected into each of the two cavities for molding the blockage suppression resin protrusions 40. At this time, the molten resin of the resin material 75 is also filled between the nano-columns 29 standing in the hole vicinity roughened portion 27 of the case lid member 21 and between the nano-columns 64 standing in the terminal roughened portion 62 of the terminal member 60. Further, the molten resin of the resin material 45 is also filled between the nano-columns 26 standing in the valve periphery roughened portion 24 of the case lid member 21. Then, a pair of terminal resin members 70 that are firmly and airtightly joined to the hole vicinity roughened portion 27 of the case lid member 21 and the terminal roughened portion 62 of the terminal member 60 are insert-molded. At the same time, a pair of blockage suppression resin protrusions 40 that are firmly joined to the valve periphery roughened portion 24 of the case lid member 21 are insert-molded (see FIG. 9). Then, the lid assembly 17 in which the terminal resin members 70 and the blockage suppression resin protrusions 40 are molded is taken out from the molding die.

[0037] Next, in the electrode body connection step S4 (see FIG. 6), an electrode body 50 obtained by laminating a positive electrode plate 51, a negative electrode plate 52, and a separator 53 is prepared, and the terminal extension portion 60b of the positive electrode terminal member 60 of the above-described lid assembly 17 is ultrasonically welded to the positive electrode current collector portion 50c of the electrode body 50. Also, the terminal extension portion 60b of the negative electrode terminal member 60 of the lid assembly 17 is ultrasonically welded to the negative electrode current collector portion 50d of the electrode body 50. Then, the electrode body 50 is wrapped with a bag-shaped insulating holder 7.

[0038] Next, in the electrode body housing / case forming step S5, a case body member 11 is prepared, the electrode body 50 covered with the above-described insulating holder 7 is inserted into the case body member 11, and the opening 11c of the case body member 11 is closed with the case lid member 21. Then, the opening 11c of the case body member 11 and the peripheral edge portion 21f of the case lid member 21 are hermetically laser welded over the entire circumference to form a case 10 that houses the electrode body 50 inside.

[0039] Next, in the electrolyte injection / sealing step S6, after inserting the injection nozzle of an injection device (not shown) into the injection hole 21k, the electrolyte 5 is ejected from the tip of the injection nozzle inside the case 10 to inject the electrolyte 5 into the case 10, and further the electrolyte 5 is impregnated into the electrode body 50. Then, the injection hole 21k is covered with a sealing member 15 from the outside, and the sealing member 15 is hermetically laser welded to the case 10. Next, in the first charging / aging step S7, a charging device (not shown) is connected to this battery 1 to perform the first charging of the battery 1. Then, the initially charged battery 1 is allowed to stand for a predetermined time to age the battery 1. Thus, the battery 1 is completed.

[0040] In the above-described method for manufacturing the battery 1, in the case roughening step S1, the inner case surface 23 of the case lid member 21 is irradiated with the pulsed laser light LB as described above to form the nano-level valve peripheral roughened portion 24 where the nano-columns 26 stand, so that the valve peripheral roughened portion 24 can be easily provided on the inner case surface 23. And in the resin molding step S3, while filling the resin material 45 between the nano-columns 26 standing on the valve peripheral roughened portion 24, the clogging suppression resin convex portion 40 is molded, so that the clogging suppression resin convex portion 40 firmly joined to the valve peripheral roughened portion 24 can be provided. Furthermore, in the first embodiment, since the terminal resin member 70 and the blockage suppression resin convex portion 40 are integrally molded, the terminal resin member 70 and the blockage suppression resin convex portion 40 can be provided easily and inexpensively.

[0041] (Embodiment 2) Next, a second embodiment will be described (see FIGS. 10 and 11). Note that descriptions of portions similar to those of the first embodiment will be omitted or simplified. In the battery 1 of the first embodiment, the blockage suppression resin convex portion 40 is provided on both sides in the longitudinal direction (battery width direction BH) of the case lid member 21 among the periphery of the safety valve 30 on the inner surface 23 of the case. In contrast, in the battery (power storage device) 100 of the second embodiment, the blockage suppression resin convex portion 140 is provided on both sides in the short direction (battery thickness direction CH) of the case lid member 21 among the periphery of the safety valve 30 on the inner surface 23 of the case, which is different.

[0042] Specifically, the inner surface 23 of the case lid member 21 of the case has a pair of valve periphery roughened portions 124 roughened around the safety valve 30. These valve periphery roughened portions 124 are provided on one side CH1 and the other side CH2 in the short direction (battery thickness direction CH) of the case lid member 21 among the periphery of the safety valve 30 on the inner surface 23 of the case, respectively, in a form extending substantially in the longitudinal direction (battery width direction BH) of the case lid member 21. Each valve periphery roughened portion 124 is a nano-level nano-roughened portion similar to the valve periphery roughened portion 24 of the first embodiment. That is, the valve periphery roughened portion 124 has a large number of bowl-shaped recesses 25 (see FIG. 7), and nano-columns 26 stand in each bowl-shaped recess 25 (see FIGS. 5 and 7).

[0043] On a pair of valve-peripheral roughened portions 124 on the inner surface 23 of the case, there are joined blocking suppression resin protrusions 140 that protrude toward the inner EH, respectively. That is, the pair of blocking suppression resin protrusions 140 extend generally in the longitudinal direction (battery width direction BH) of the case lid member 21 on one side CH1 and the other side CH2 in the short-side direction (battery thickness direction CH) of the case lid member 21 among the periphery of the safety valve 30, and protrude toward the inner EH, respectively. The blocking suppression resin protrusions 140 of the second embodiment 2 can also suppress the fragments of the electrode body 50 from blocking the safety valve 30 from the inner EH to the outer DH when the electrode body 50 is broken. Further, the blocking suppression resin protrusions 140 are filled with a resin material 45 between the nano-columns 26 standing on the valve-peripheral roughened portion 124 of the inner surface 23 of the case, and are joined to the valve-peripheral roughened portion 124 with a strong bonding force.

[0044] The battery 100 of the second embodiment 2 is also provided with the blocking suppression resin protrusions 140 around the safety valve 30 on the inner surface 23 of the case lid member 21 of the case. For this reason, since it is possible to suppress the fragments of the broken electrode body 50 from blocking the safety valve 30, the safety valve 30 functions appropriately. Further, the resin material 45 is filled between the nano-columns 26 standing on the valve-peripheral roughened portion 124, and the blocking suppression resin protrusions 140 are joined to the valve-peripheral roughened portion 124. For this reason, the bonding strength between the case lid member 21 and the blocking suppression resin protrusions 140 can be increased.

[0045] The battery 100 of the second embodiment 2 can also be manufactured in the same manner as the battery 1 of the first embodiment. Therefore, the manufacturing method of the battery 100 of the second embodiment 2 can also obtain the same operational effects as the manufacturing method of the battery 1 of the first embodiment. In addition, in Embodiment 1, in the liquid injection and sealing step S6, when the electrolytic solution 5 is ejected from the tip of the liquid injection nozzle inserted into the liquid injection hole 21k to one side BH1 and the other side BH2 in the battery width direction BH, respectively, the electrolytic solution 5 hits the blockage suppression resin convex portion 40 extending in the battery thickness direction CH, and bubbles may be generated, or the electrolytic solution 5 may adhere to the inner surface 23 of the case of the case lid member 21. In contrast, in the present Embodiment 2, since the blockage suppression resin convex portion 140 is provided at both ends in the battery thickness direction CH in a form extending in the battery width direction BH, it is difficult for the electrolytic solution 5 ejected in the battery width direction BH from the tip of the liquid injection nozzle to hit the blockage suppression resin convex portion 140. For this reason, there is an advantage that bubbles are hardly generated and the electrolytic solution 5 hardly adheres to the inner surface 23 of the case.

[0046] (Embodiment 3) Next, a third embodiment will be described (see FIGS. 12 and 13). Note that the description of the same parts as in Embodiment 1 or 2 will be omitted or simplified. In the battery (power storage device) 200 of the present Embodiment 2, the form of the blockage suppression resin convex portion 240 is different from the forms of the blockage suppression resin convex portions 40 and 140 of Embodiments 1 and 2, and a plurality of dot-shaped blockage suppression resin convex portions 240 are provided around the safety valve 30 on the inner surface 23 of the case over the entire circumference.

[0047] Specifically, the inner surface 23 of the case of the case lid member 21 has a plurality of dot-shaped valve periphery roughened portions 224 arranged with a gap around the safety valve 30 over the entire circumference. Each valve periphery roughened portion 224 is a nano-level nano-roughened portion similar to the valve periphery roughened portions 24 and 124 of Embodiments 1 and 2. That is, the valve periphery roughened portion 224 has a large number of bowl-shaped recesses 25 (see FIG. 7), and nano-columns 26 stand in each bowl-shaped recess 25 (see FIGS. 5 and 7).

[0048] On the plurality of valve-peripheral roughened portions 224 on the inner surface 23 of the case, dot-shaped resin protrusions 240 for suppressing blockage that protrude toward the inner EH are joined respectively. That is, the plurality of resin protrusions 240 for suppressing blockage are arranged with a gap all around the periphery of the safety valve 30 and each protrude toward the inner EH. The resin protrusions 240 for suppressing blockage in the third embodiment 3 can also suppress the fragments of the electrode body 50 from blocking the safety valve 30 from the inner EH to the outer DH when the electrode body 50 breaks. Further, the resin protrusions 240 for suppressing blockage are filled with a resin material 45 between the nano-columns 26 standing on the valve-peripheral roughened portions 224 on the inner surface 23 of the case and are joined to the valve-peripheral roughened portions 224 with a strong bonding force.

[0049] The battery 200 in the third embodiment 3 also has resin protrusions 240 for suppressing blockage provided around the safety valve 30 on the inner surface 23 of the case of the case lid member 21. For this reason, since it is possible to suppress the fragments of the broken electrode body 50 from blocking the safety valve 30, the safety valve 30 functions properly. Further, the resin material 45 is filled between the nano-columns 26 standing on the valve-peripheral roughened portions 224 and the resin protrusions 240 for suppressing blockage are joined to the valve-peripheral roughened portions 224. For this reason, the bonding strength between the case lid member 21 and the resin protrusions 240 for suppressing blockage can be increased. Note that the battery 200 in the second embodiment 3 can also be manufactured in the same manner as the batteries 1 and 100 in the first and second embodiments. Therefore, the manufacturing method of the battery 200 in the third embodiment 3 can also obtain the same operational effects as the manufacturing methods of the batteries 1 and 100 in the first and second embodiments.

[0050] As described above, the present invention has been described with reference to the first to third embodiments, but needless to say, the present invention is not limited to the first to third embodiments and can be appropriately modified and applied without departing from the gist thereof.

Explanation of reference numerals

[0051] 1, 100, 200 Battery (power storage device) 10 Case 21 Case lid member (case member) 21Z Case lid member (before roughening) 21h Insertion hole Inner surface of the case (of the case lid member) 24, 124, 244 Roughened portion around the valve (of the inner surface of the case) 26 Nanopillars 26p Particles 30 Safety valve 40, 140, 240 Resin convex portion for suppressing blockage 45 Resin material (forming the resin convex portion for suppressing blockage) 50 Electrode body 60 Terminal member 60Z Terminal member (before roughening) 70 Terminal resin member 75 Resin material (forming the terminal resin member) DH Outer side (of the case lid member) EH Inner side (of the case lid member) LB Pulse laser light S1 Case roughening process S2 Terminal roughening process S3 Resin molding process

Claims

1. A case having a metal case member, a safety valve provided on the case member, and an electrode body housed in the case, The power storage device is wherein the case member has a roughened valve surrounding roughened portion around the safety valve among the inner case inner surfaces located inside, a resin convex portion made of resin that is joined to the roughened portion around the valve on the inner case inner surface and protrudes inward, and when the electrode body breaks, the safety valve is blocked from the inside by fragments of the electrode body. Further provided is a blockage suppression resin convex portion that suppresses this, in the roughened portion around the valve, nanocolumns having a height of 50 nm or more and formed by beads of particles derived from the metal forming the case member are standing in a row, the blockage suppression resin convex portion is formed by filling a resin material forming the blockage suppression resin convex portion between the standing nanocolumns and joining to the roughened portion around the valve, Power storage device.

2. A case having a metal case member, a safety valve provided on the case member, and an electrode body housed in the case, wherein the case member has a roughened valve surrounding roughened portion around the safety valve among the inner case inner surfaces located inside, a resin convex portion made of resin that is joined to the roughened portion around the valve on the inner case inner surface and protrudes inward, and when the electrode body breaks, the safety valve is blocked from the inside by fragments of the electrode body. Further provided is a blockage suppression resin convex portion that suppresses this, in the roughened portion around the valve, nanocolumns having a height of 50 nm or more and formed by beads of particles derived from the metal forming the case member are standing in a row, the blockage suppression resin convex portion is formed by filling a resin material forming the blockage suppression resin convex portion between the standing nanocolumns and joining to the roughened portion around the valve, A method for manufacturing a power storage device, a case roughening step of intermittently irradiating the inner case inner surface of the case member with pulsed laser light while shifting the irradiation position to form the roughened portion around the valve where the nanocolumns stand, a resin molding step of molding the blockage suppression resin convex portion while filling the resin material between the standing nanocolumns in the roughened portion around the valve, Method for manufacturing a power storage device.

3. The method for manufacturing a power storage device according to claim 2, wherein the case member has an insertion hole, a terminal member inserted into the insertion hole of the case member, Furthermore, a terminal resin member is provided which insulates between the case member and the terminal member while joining them to fix the terminal member to the case member. The resin molding step is while the terminal member is inserted into the insertion hole of the case member, molding the terminal resin member that joins the case member and the terminal member, and molding the closing suppression resin convex portion that joins the case member. A method for manufacturing a power storage device.

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