Electricity storage device

Abstract

This electricity storage device is provided with: a housing having a metal housing member including a valve hole; a metal relief valve member including a pressure release type relief valve part that breaks to open the valve when the internal pressure of the housing exceeds the valve opening pressure; and an annular valve-fixing resin member which is interposed between a hole peripheral portion surrounding the valve hole in the housing member and a peripheral edge portion of the safety valve member, and which fixes the safety valve member to the housing member by being hermetically joined around the entire circumference thereof.

Description

Technical Field

[0001] The present disclosure relates to an electric storage device in which a pressure release type safety valve portion is provided in a metal housing component constituting a housing. Background Art

[0002] As an electric storage device, a battery in which a pressure release type safety valve portion is provided in a metal housing is known. When the internal pressure of the housing exceeds the opening pressure, the safety valve portion ruptures and opens, discharging the gas inside the housing to the outside of the housing. This safety valve portion is formed by thinning a part of the housing component (for example, a housing lid component, etc.) by stamping and forming a groove portion for cracking by stamping. For example, a battery having such a safety valve portion is disclosed in Patent Document 1.

[0003] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2018-032605

[0004] However, in the case where a safety valve portion is integrally formed in the housing component by stamping a part of the housing component as described above, there are cases where it is difficult to appropriately form a desired shape of the safety valve portion depending on the thickness and material of the housing component. For example, if the thickness of the housing component increases with the enlargement of the battery, there are cases where it is difficult to integrally form a safety valve portion having a thickness and a bottom thickness of the groove portion that can obtain a desired opening pressure in the housing component. Summary of the Invention

[0005] The present disclosure has been made in view of this situation, and provides an electric storage device capable of easily providing a pressure release type safety valve portion in a housing component regardless of the thickness and material of the metal housing component.

[0006] (1) One aspect of the present disclosure for solving the above problems is an electric storage device including: a housing having a metal housing component including a valve hole; a metal safety valve component including a pressure release type safety valve portion that ruptures and opens when the internal pressure of the housing exceeds an opening pressure; and a ring-shaped resin valve fixing resin component interposed between a hole peripheral portion of the housing component that surrounds the valve hole and a peripheral edge portion of the safety valve component, and hermetically joined to each of the hole peripheral portion and the peripheral edge portion around the entire circumference thereof, thereby fixing the safety valve component to the housing component.

[0007] In the above-described power storage device, a safety valve component including a pressure release type safety valve portion that opens due to an increase in the internal pressure of the housing is fixed to the housing component via a valve fixing resin component. The safety valve component is a component separate from the housing component and is formed separately from the housing component. Therefore, it is not affected by the thickness and material of the housing component, and a safety valve component having a desired shape can be appropriately formed. Then, the safety valve component is fixed to the housing component via the valve fixing resin component, whereby the safety valve portion can be easily provided on the housing component.

[0008] In addition, compared with the housing component made of metal, the valve fixing resin component made of resin is softer. Therefore, when using the housing component to form the housing, even when the housing component is deformed, it is difficult for the safety valve component connected to the housing component via the valve fixing resin component to be deformed. Thus, in the above-described power storage device, even when the housing component is deformed, the deformation of the safety valve component is small, and thus it is possible to suppress a negative impact on the opening pressure of the safety valve portion and the like.

[0009] In addition, as the "power storage device", for example, secondary batteries such as lithium ion secondary batteries, sodium ion secondary batteries, and calcium ion secondary batteries, and capacitors such as lithium ion capacitors can be cited.

[0010] (2) It can also be configured such that, based on the power storage device described in (1), the valve fixing resin component is made of a thermoplastic resin material, and the safety valve component and the valve fixing resin component form a temperature release type safety valve that opens when the resin material softens or melts due to an increase in the temperature of the valve fixing resin component.

[0011] The safety valve component and the valve fixing resin component constitute a temperature release type safety valve that opens due to an increase in temperature. That is, the above-described power storage device has a pressure release type safety valve portion and also has a temperature release type safety valve. Therefore, the power storage device can be made into a power storage device with higher safety.

[0012] (3) It can also be configured such that, based on the power storage device described in (1) or (2), the peripheral portion of the hole of the housing component includes a hole peripheral roughened portion, which is a ring-shaped portion that surrounds the entire periphery of the hole peripheral portion, and nanocolumns having a height of 50 nm or more are formed in a columnar shape with particles derived from the metal forming the housing component bonded in a bead shape standing upright. The valve fixing resin component is formed by filling the resin material for forming the valve fixing resin component between the standing upright nanocolumns and hermetically bonding to the hole peripheral roughened portion around the entire periphery.

[0013] In the above-described power storage device, a nano-level (nanoscale) hole periphery roughened portion with the above-described nano-columns standing is provided around the hole of the housing member, and a resin material is filled between the standing nano-columns to hermetically bond the valve fixing resin member to the hole periphery roughened portion. Therefore, the sealing performance and bonding strength between the hole periphery portion of the housing member and the valve fixing resin member can be improved.

[0014] (4) It may also be configured that, based on the power storage device described in any one of (1) to (3), the peripheral portion of the above-described safety valve member includes a valve peripheral roughened portion which is an annular shape surrounding the entire periphery of the above-described peripheral portion, in which nano-columns with a height of 50 nm or more are formed by standing in a bead shape with particles derived from the metal forming the above-described safety valve member combined into columns, and the above-described valve fixing resin member is formed by filling the resin material forming the above-described valve fixing resin member between the standing above-described nano-columns and hermetically bonding to the above-described valve peripheral roughened portion around the entire circumference.

[0015] In the above-described power storage device, a nano-level valve peripheral roughened portion with the above-described nano-columns standing is provided around the peripheral portion of the safety valve member, and a resin material is filled between the standing nano-columns to hermetically bond the valve fixing resin member to the valve peripheral roughened portion. Therefore, the sealing performance and bonding strength between the peripheral portion of the safety valve member and the valve fixing resin member can be improved.

[0016] (5) It may also be configured that, based on the power storage device described in any one of (1) to (4), the above-described safety valve member is made of an aluminum plate with a thickness of 500 μm or less, and the above-described safety valve portion is formed by stamping.

[0017] Since the safety valve member uses a thin aluminum plate with a thickness of 500 μm or less, the safety valve portion can be easily formed by stamping with high precision. Therefore, the above-described power storage device can be a power storage device having a safety valve member with a particularly stable opening pressure of the safety valve portion.

[0018] (6) It may also be configured that, based on the power storage device described in (5), the above-described housing member is made of an aluminum plate with a thickness of 600 μm or more.

[0019] As in the past, in a form in which a part of a housing member is stamped and a safety valve portion is integrally formed on the housing member, if the thickness of the housing member made of aluminum is increased to 600 μm or more, it may be difficult to integrally stamp and form the safety valve portion on the housing member. In contrast, in the above-described power storage device, the housing member and the safety valve member are separate members, so that the safety valve portion can be easily and highly accurately stamped and formed on the safety valve member regardless of the thickness of the housing member. Therefore, even though the housing member is made of an aluminum plate having a thickness of 600 μm or more, the above-described power storage device can be a power storage device including a safety valve member having a particularly stable opening pressure of the safety valve portion.

[0020] (7) It may also be configured that, based on the power storage device described in (5), the above-described housing member is made of a metal other than aluminum.

[0021] As the housing member, there is a case where a housing member made of a metal other than aluminum such as stainless steel is used, for example. In contrast, in the above-described power storage device, the housing member and the safety valve member are separate members, so that the safety valve portion can be easily and highly accurately stamped and formed on the safety valve member regardless of the material of the housing member. Therefore, in the above-described power storage device, even though the housing member is made of a metal other than aluminum, it can be a power storage device including a safety valve member having a particularly stable opening pressure of the safety valve portion. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a perspective view of the battery according to the embodiment.

[0023] Figure 2 is a partial cross-sectional view of the battery according to the embodiment along the battery height direction and the battery width direction.

[0024] Figure 3 is a top view of the vicinity of the safety valve portion in the battery according to the embodiment.

[0025] Figure 4 is the vicinity of the safety valve portion in the battery according to the embodiment Figure 3 in a cross-sectional view in the direction of the arrow.

[0026] Figure 5 is an enlarged cross-sectional view showing an enlarged view of the joint portion between the hole peripheral portion (or the peripheral edge portion of the safety valve member) of the housing cover member according to the embodiment and the valve fixing resin member.

[0027] Figure 6 is a flowchart of the manufacturing method of the battery according to the embodiment.

[0028] Figure 7This is an explanatory diagram showing a case where, in the case of the manufacturing method of the battery according to the embodiment, pulsed laser is scanned in the case roughening process (or valve roughening process, or terminal roughening process) to form a plurality of bowl-shaped recesses and nano-columns standing in the bowl-shaped recesses.

[0029] Explanation of reference numerals

[0030] 1, 100... Battery (power storage device); 10, 110... Case; 11, 111... Case main body member; 21, 121... Case cover member (case member); 21i... Valve hole; 23... Port peripheral portion; 24... Port peripheral roughened portion; 24a... First port peripheral roughened portion; 24b... Second port peripheral roughened portion; 26... Nano-column; 26p... Particle; 30... Safety valve member; 31... (Pressure release type) safety valve portion; 33... (Peripheral portion of the safety valve member); 34... Valve peripheral roughened portion; 34a... First valve peripheral roughened portion; 34b... Second valve peripheral roughened portion; 36... Nano-column; 36p... Particle; 40... Valve fixing resin member; 41... Resin material; 45... (Temperature release type) safety valve; 50... Electrode body; 60... Terminal member; 70... Terminal fixing resin member; ta... (Thickness of the case cover member); tb... (Thickness of the safety valve member); ha... (Height of the nano-column). Detailed implementation manners

[0031] (Embodiment)

[0032] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In Figure 1 a perspective view of the battery (power storage device) 1 of the present embodiment is shown, and in Figure 2 a partial cross-sectional view of the battery 1 is shown. In addition, regarding the vicinity of the safety valve portion 31 in the battery 1, in Figure 3 a top view is shown, and in Figure 4 a cross-sectional view is shown. And, in Figure 5 an enlarged cross-sectional view of the joint portion between the port peripheral portion 23 of the case cover member 21 (or the peripheral portion 33 of the safety valve member 30) and the valve fixing resin member 40 is shown. In addition, hereinafter, the battery height direction AH, the battery width direction BH, and the battery thickness direction CH of the battery 1 are determined as Figure 1 and Figure 2 the directions shown for description.

[0033] The battery 1 is a square (rectangular parallelepiped-shaped) and sealed lithium-ion secondary battery mounted on vehicles such as hybrid vehicles, plug-in hybrid vehicles, and electric vehicles. The battery 1 is composed of a metal housing 10 provided with a safety valve portion 31, an electrode body 50 and an electrolyte 5 accommodated in the housing 10, and positive and negative terminal components 60 respectively fixed to the housing 10 via terminal fixing resin components 70. The electrode body 50 is insulated and held by an insulating holder 7 in the housing 10. The insulating holder 7 is formed of an insulating film and is in the shape of a bag that opens upward in the battery height direction AH1.

[0034] The electrode body 50 is rectangular parallelepiped-shaped and laminated. A plurality of rectangular positive plates 51 and a plurality of rectangular negative plates 52 are alternately laminated in the battery thickness direction CH with a rectangular separator 53 formed of a resin porous film interposed therebetween. On one side BH1 in the battery width direction BH of the electrode body 50, the current collector foils of the respective positive plates 51 overlap in the battery thickness direction CH to form a positive current collector portion 50c. On the other side BH2 in the battery width direction BH of the electrode body 50, the current collector foils of the respective negative plates 52 overlap in the battery thickness direction CH to form a negative current collector portion 50d.

[0035] The housing 10 is a cubic box-shaped body made of metal (aluminum in the present embodiment), and is a bottomed square tube-shaped body having a rectangular opening 11c. It is composed of a housing main body component 11 that houses the electrode body 50 inside, and a rectangular plate-shaped housing cover component 21 that closes the opening 11c of the housing main body component 11. The opening 11c of the housing main body component 11 and the peripheral edge portion 21f of the housing cover component 21 are hermetically welded around the entire circumference. In the present embodiment, the housing cover component 21 corresponds to the above-mentioned "housing component". The housing cover component 21 is composed of an aluminum plate having a thickness ta (refer to Figure 4 ) of 600 μm or more (in the present embodiment, the thickness ta = 600 μm). A liquid injection hole 21k is provided in the housing cover component 21, and the liquid injection hole 21k is hermetically sealed by a disk-shaped sealing member 15.

[0036] In addition, an oval valve hole 21i is provided near the center in the battery width direction BH of the housing cover component 21. In the valve hole 21i, an oval plate-shaped safety valve member 30 including a pressure release type safety valve portion 31 is installed via an oval ring-shaped valve fixing resin component 40 (refer to Figures 1 to 4 ). That is, the valve fixing resin component 40 is interposed between the hole peripheral portion 23 surrounding the valve hole 21i in the housing cover component 21 and the peripheral edge portion 33 of the safety valve member 30, and is hermetically joined around the entire circumference of the hole peripheral portion 23 and the peripheral edge portion 33, thereby fixing the safety valve member 30 to the housing cover component 21.

[0037] The safety valve component 30 is made of a metal plate (in this embodiment, an aluminum plate), is oblong and slightly smaller than the valve hole 21i, and is a plate-like shape with a thickness tb of 500 μm or less (in this embodiment, the thickness tb = 80 μm), which is thinner than the thickness ta of the housing lid component 21. The dimension in the long side direction (battery width direction BH) of the safety valve component 30 is 15 mm, and the dimension in the short side direction (battery thickness direction CH) is 5 mm. In this embodiment, the entire central portion except for the peripheral portion 33 of the safety valve component 30 becomes a pressure release type safety valve portion 31 that ruptures and opens when the internal pressure of the housing 10 exceeds the opening pressure. The safety valve portion 31 is formed by stamping and has a rupture portion 32 with a specified shape formed by a V-groove. The thickness at the bottom of the V-groove of the rupture portion 32 (the thickness of the thinnest portion of the safety valve portion 31) is 50 μm.

[0038] A valve fixing resin component 40 is joined to the peripheral portion 33 of the safety valve component 30. Specifically, on the surface 33m of the peripheral portion 33, the portions other than the outer peripheral end face, that is, the peripheral portion outer side face 33ma facing outward (in this embodiment, the upper side AH1) and the peripheral portion inner side face 33mb facing inward (in this embodiment, the lower side AH2 in the battery height direction AH) respectively have an oblong ring shape surrounding the entire periphery of the peripheral portion 33 and become roughened valve peripheral roughened portions 34 (the first valve peripheral roughened portion 34a and the second valve peripheral roughened portion 34b). The widths (sealing widths) of the first valve peripheral roughened portion 34a (peripheral portion outer side face 33ma) and the second valve peripheral roughened portion 34b (peripheral portion inner side face 33mb) are each 0.5 mm or more (in this embodiment, 0.5 mm).

[0039] The valve peripheral roughened portion 34 is roughened by a pulsed laser LB described later (see Figure 7 ), and becomes a nano-scale nano-roughened portion. Specifically, in the valve peripheral roughened portion 34, a plurality of bowl-shaped recesses 35 with a diameter Da of 30 to 300 μm (in this embodiment, the approximate diameter Da = 80 μm) that are recessed in a bowl shape or a pit shape are arranged in a partially overlapping manner (see Figure 7 ). In these bowl-shaped recesses 35, nano-columns 36 with a height ha of 50 nm or more (in this embodiment, the approximate height ha = 200 nm) are formed by beads of particles 36p of the metal forming the safety valve component 30 standing in a columnar shape (see Figure 5 and Figure 7 ). As described above, the metal forming the safety valve component 30 is aluminum, and the nano-columns 36 are formed by particles 36p composed of aluminum and aluminum oxide.

[0040] In addition, a valve fixing resin member 40 is also joined to the peripheral portion 23 of the hole in the housing cover member 21. Specifically, in the surface 23m of the peripheral portion 23 of the hole, the portions other than the inner peripheral surface of the hole, that is, the outer peripheral surface 23ma of the peripheral portion facing outward (in the present embodiment, the upper side AH1) and the inner peripheral surface 23mb of the peripheral portion facing inward (in the present embodiment, the lower side AH2) each have an oval ring shape surrounding the entire periphery of the peripheral portion 23 of the hole, and become a roughened peripheral portion of the hole 24 (the first roughened peripheral portion of the hole 24a and the second roughened peripheral portion of the hole 24b). The widths (sealing widths) of the first roughened peripheral portion of the hole 24a (the outer peripheral surface 23ma of the peripheral portion) and the second roughened peripheral portion of the hole 24b (the inner peripheral surface 23mb of the peripheral portion) are each 0.5 mm or more (in the present embodiment, 0.5 mm).

[0041] The roughened peripheral portion of the hole 24 is the same as the roughened peripheral portion 34 of the valve periphery of the above-described safety valve member 30, and becomes a nano-level nano-roughened portion. That is, the roughened peripheral portion of the hole 24 has a plurality of bowl-shaped recesses 25 (see Figure 7 ), and in each bowl-shaped recess 25, nano-columns 26 having a height ha of 50 nm or more (in the present embodiment, the approximate height ha = 200 nm) are formed by beads of particles 26p derived from the metal (specifically, aluminum) forming the housing cover member 21 being joined in a string shape and becoming columnar (see Figure 5 and Figure 7 ).

[0042] The valve fixing resin member 40 is made of a thermoplastic resin material 41. The resin material 41 includes a thermoplastic main resin (in the present embodiment, polyphenylene sulfide (PPS)), a thermoplastic elastomer (in the present embodiment, a thermoplastic polyurethane elastomer), and a filler (in the present embodiment, fibrous glass filler). For the valve fixing resin member 40, the above-described resin material 41 is filled between the nano-columns 36 standing on the roughened peripheral portion 34 of the valve periphery of the safety valve member 30, and is hermetically joined to the roughened peripheral portion 34 of the valve periphery with a strong bonding force around the entire circumference. In addition, for the valve fixing resin member 40, the above-described resin material 41 is filled between the nano-columns 26 standing on the roughened peripheral portion 24 of the hole in the housing cover member 21, and is hermetically joined to the roughened peripheral portion 24 of the hole with a strong bonding force around the entire circumference.

[0043] In addition, the above-described resin material 41 forming the valve fixing resin member 40 softens or melts at approximately 250°C. Therefore, the valve fixing resin member 40 and the above-described safety valve member 30 constitute a temperature release type safety valve 45 that opens when the temperature of the valve fixing resin member 40 rises, specifically, when the valve fixing resin member 40 reaches about 250°C and the resin material 41 softens or melts.

[0044] Next, the terminal member 60 and the terminal fixing resin member 70 will be described (see Figure 1 and Figure 2 ). Rectangular insertion holes 21h are respectively provided near the ends of one side BH1 and the other side BH2 in the battery width direction BH of the housing cover member 21. A terminal member 60 of the positive electrode made of aluminum is inserted into the insertion hole 21h on one side BH1. The terminal fixing resin member 70 of the positive electrode insulates between the housing cover member 21 and the terminal member 60, and is hermetically joined to the housing cover member 21 and the terminal member 60, and fixes the terminal member 60 to the housing cover member 21. A terminal member 60 of the negative electrode made of copper is inserted into the insertion hole 21h on the other side BH2. The terminal fixing resin member 70 of the negative electrode insulates between the housing cover member 21 and the terminal member 60, and is hermetically joined to the housing cover member 21 and the terminal member 60, and fixes the terminal member 60 to the housing cover member 21. The positive and negative terminal members 60 have the same form, and the positive and negative terminal fixing resin members 70 also have the same form, so the following description will be unified.

[0045] Each terminal member 60 is formed by stamping a metal plate (aluminum plate for the positive electrode and copper plate for the negative electrode). The terminal member 60 is composed of a rectangular plate-shaped terminal top plate portion 60a located on the upper side AH1 of the housing cover member 21 and extending in the battery width direction BH and the battery thickness direction CH, and a terminal extension protrusion 60b extending from the terminal top plate portion 60a to the lower side AH2 in the battery height direction AH. The terminal extension protrusion 60b buckles at the end of the terminal top plate portion 60a on the side CH1 in the battery thickness direction CH and extends downward to the lower side AH2, passes through the insertion hole 21h in the housing cover member 21, and further penetrates the terminal fixing resin member 70 and extends downward to the lower side AH2. The front end of the positive terminal extension protrusion 60b on the lower side AH2 is welded to the positive current collector portion 50c of the electrode body 50. On the other hand, the front end of the negative terminal extension protrusion 60b on the lower side AH2 is welded to the negative current collector portion 50d of the electrode body 50.

[0046] The terminal fixing resin member 70 is composed of a thermoplastic resin material 71. In the present embodiment, the resin material 71 is the same as the resin material 41 forming the valve fixing resin member 40, but the resin material 71 and the resin material 41 can also be different resin materials. The terminal fixing resin member 70 is hermetically joined to the portion of the housing cover member 21 surrounding the insertion hole 21h, and is hermetically joined to the portion near the insertion hole 21h in the terminal member 60, and fixes the terminal member 60 to the housing cover member 21.

[0047] In addition, detailed descriptions are omitted, but at the portions in the housing cover member 21 where the terminal fixing resin member 70 is joined, and at the portions in the terminal member 60 where the terminal fixing resin member 70 is joined, there are also provided nano-level nano roughened portions where the above-described nano-columns stand. Moreover, for the terminal fixing resin member 70, a resin material 71 is filled between the nano-columns standing in these nano roughened portions, and it is hermetically joined to the housing cover member 21 and the terminal member 60 with a strong joining force.

[0048] In the battery 1 of the present embodiment, a safety valve member 30 including a pressure release type safety valve portion 31 that ruptures and opens the valve due to an increase in the internal pressure of the housing 10 is fixed to the housing cover member 21 via a valve fixing resin member 40. The safety valve member 30 is a member separate from the housing cover member 21 and is formed separately from the housing cover member 21. Therefore, it is not affected by the thickness ta and material of the housing cover member 21, and a safety valve member 30 having a desired shape can be appropriately formed. Then, the safety valve member 30 is fixed to the housing cover member 21 via the valve fixing resin member 40, whereby the safety valve portion 31 can be easily provided in the housing cover member 21.

[0049] In addition, compared with the housing cover member 21 made of metal, the valve fixing resin member 40 made of resin is softer. Therefore, when the housing 10 is formed by welding the peripheral portion 21f of the housing cover member 21 to the opening portion 11c of the housing main body member 11 around the entire circumference, even when the housing cover member 21 is deformed, it is difficult for the safety valve member 30 connected to the housing cover member 21 via the valve fixing resin member 40 to be deformed. Thus, in the battery 1, even when the housing cover member 21 is deformed, the deformation of the safety valve member 30 is small, and thus a negative influence on the opening pressure of the safety valve portion 31 can be suppressed.

[0050] And, in the present embodiment, the valve fixing resin member 40 is made of a thermoplastic resin material 41, and the safety valve member 30 and the valve fixing resin member 40 constitute a temperature release type safety valve 45 that opens due to a temperature rise. That is, the battery 1 has a pressure release type safety valve portion 31 and also has a temperature release type safety valve 45. Therefore, the battery 1 can be made into a battery with higher safety.

[0051] In addition, in the present embodiment, a hole peripheral roughened portion 24 where nano-columns 26 stand is provided at the hole peripheral portion 23 of the housing cover member 21, and a resin material 41 is filled between the standing nano-columns 26 to hermetically join the valve fixing resin member 40 to the hole peripheral roughened portion 24. Therefore, the sealing performance and joining strength between the hole peripheral portion 23 of the housing cover member 21 and the valve fixing resin member 40 can be improved.

[0052] In addition, a nanometer-scale valve peripheral roughening portion 34 in which nanopillars 36 are arranged is provided on the peripheral portion 33 of the safety valve member 30, and a resin material 41 is filled between the nanopillars 36, so that the valve fixing resin member 40 and the valve peripheral roughening portion 34 are airtightly joined. Therefore, the sealing property and the joining strength between the peripheral portion 33 of the safety valve member 30 and the valve fixing resin member 40 can be improved.

[0053] In addition, in the present embodiment, the safety valve member 30 uses a thin aluminum plate having a thickness tb of 500 μm or less, so the safety valve portion 31 can be easily and accurately formed by press forming. Therefore, the battery 1 can be a battery having a safety valve member 30 with a particularly stable valve opening pressure of the safety valve portion 31.

[0054] In addition, since the case cover member 21 and the safety valve member 30 are separate components, the safety valve portion 31 can be easily and accurately stamped on the safety valve member 30 regardless of the thickness ta of the case cover member 21. Therefore, in the battery 1, even though the case cover member 21 is made of an aluminum plate having a thickness ta of 600 μm or more, it is possible to provide a battery having a safety valve member 30 with a particularly stable valve opening pressure of the safety valve portion 31.

[0055] Next, a method for manufacturing the battery 1 will be described (see Figure 6 and Figure 7 ). First, the housing cover member 21Z before roughening, the safety valve member 30Z before roughening, and the positive and negative terminal members 60Z before roughening are prepared. The safety valve portion 31 including the rupture portion 32 is formed in the safety valve member 30Z before roughening by press forming.

[0056] Furthermore, in the shell roughening step S1 (see Figure 6 ), the outer peripheral surface 23ma and the inner peripheral surface 23mb of the hole peripheral portion 23 of the housing cover member 21Z are intermittently irradiated with pulse laser LB while shifting the irradiation position, thereby forming a large number of bowl-shaped recesses 25 with a forest of nanocolumns 26 and a partially overlapping arrangement of the hole peripheral roughening portion 24 (the first hole peripheral roughening portion 24a and the second hole peripheral roughening portion 24b) (see Figure 7 ). As for the laser irradiation conditions, the wavelength is set to 1064nm, the peak output is set to 5kW, the pulse width is set to 150ns, the pitch pb is set to 75μm, and the spot diameter Da is set to 80μm. In addition, the portion surrounding the pair of insertion holes 21h in the housing cover member 21Z is also irradiated with the pulse laser LB to form a nano-roughened portion.

[0057] In the portion of the housing cover 21Z irradiated with the pulse laser LB, the metal (specifically, aluminum) near the surface is dissolved and further becomes vapor. Thereafter, when the temperature of the vapor decreases, particles 26p of aluminum and aluminum oxide are formed and accumulated in the bowl-shaped recess 25. By intermittently irradiating the housing cover 21Z with the pulse laser LB while shifting the irradiation position, the particles 26p are accumulated and combined into a beaded shape and then into a columnar shape, forming a forest of nanopillars 26 (see Figure 5 and Figure 7 ).

[0058] In addition, in the valve roughening step S2 (refer to Figure 6 ), the outer peripheral surface 33ma and the inner peripheral surface 33mb of the peripheral portion 33 of the safety valve member 30Z are intermittently irradiated with pulse laser LB while shifting the irradiation position, thereby forming a valve peripheral roughening portion 34 (a first valve peripheral roughening portion 34a and a second valve peripheral roughening portion 34b) in which a large number of bowl-shaped recesses 35 with nanocolumns 36 are partially overlapped and arranged (refer to Figure 7 ) In addition, the irradiation conditions of the laser beam to the safety valve member 30Z are the same as the irradiation conditions in the housing roughening step S1.

[0059] In addition, in the terminal roughening step S3 (refer to Figure 6 ) in which the pulse laser LB is intermittently irradiated onto the predetermined portions of the positive and negative terminal members 60Z while shifting the irradiation positions to form nano-roughened portions.

[0060] Next, in the resin molding step S4, the safety valve member 30 is arranged in the valve hole 21i of the housing cover member 21 using a molding die (not shown), and the positive and negative terminal members 60 are inserted into the pair of insertion holes 21h of the housing cover member 21. Thereafter, the molten resin of the resin material 41, 71 is injected into each cavity (not shown), so that the valve fixing resin member 40 joined to the housing cover member 21 and the safety valve member 30 is insert-molded, and the pair of terminal fixing resin members 70 joined to the housing cover member 21 and the positive and negative terminal members 60 are insert-molded.

[0061] Next, in the electrode body connection step S5, an electrode body 50 obtained by stacking the positive electrode plate 51, the negative electrode plate 52, and the separator 53 is prepared, and the terminal extension protrusion 60b of the positive terminal member 60 is ultrasonically welded to the positive electrode collector 50c of the electrode body 50. In addition, the terminal extension protrusion 60b of the negative terminal member 60 is ultrasonically welded to the negative electrode collector 50d of the electrode body 50. Thereafter, the electrode body 50 is covered with a bag-shaped insulating holder 7.

[0062] Next, in the electrode body accommodation and housing formation step S6, the housing main body member 11 is prepared, the electrode body 50 covered with the above-described insulating holding member 7 is inserted into the housing main body member 11, and the opening 11c of the housing main body member 11 is blocked with the housing cover member 21. Then, the opening 11c of the housing main body member 11 and the peripheral edge portion 21f of the housing cover member 21 are laser welded airtightly around the entire circumference to form the housing 10.

[0063] Next, in the liquid injection and sealing step S7, the electrolytic solution 5 is injected into the housing 10 through the liquid injection hole 21k so that the electrolytic solution 5 is impregnated into the electrode body 50. Thereafter, the liquid injection hole 21k is hermetically sealed with the sealing member 15.

[0064] Next, in the initial charging and aging step S8, the battery 1 is initially charged. Thereafter, the battery 1 is allowed to stand for a predetermined time to age the battery 1. Thus, the battery 1 is completed.

[0065] (Modified form)

[0066] Next, a modified form of the above-described embodiment will be described (see Figures 1 to 4 ). In addition, the description of parts identical to those of the embodiment will be omitted or simplified. In the battery 1 of the embodiment, the housing 10 is formed of an aluminum plate. In contrast, in the battery (power storage device) 100 of the present modified form, the housing 110 is formed of a stainless steel plate. That is, the housing 110 is composed of a housing main body member 111 made of a stainless steel plate and a housing cover member (housing member) 121 made of a stainless steel plate. On the other hand, the safety valve member 30 having the safety valve portion 31 is the same as that of the embodiment.

[0067] In the present modified form, the housing cover member 121 and the safety valve member 30 are also separate members. Therefore, the safety valve portion 31 can be easily and highly accurately stamped on the safety valve member 30 regardless of the material of the housing cover member 121. Therefore, in the battery 100, even though the housing cover member 121 is made of a metal other than aluminum, it is possible to obtain a battery having a safety valve member 30 with a particularly stable opening pressure of the safety valve portion 31. In addition, the parts identical to those of the embodiment also exhibit the same effects as those of the embodiment in the battery 100 of the present modified form.

[0068] As described above, the present disclosure has been described based on the embodiment and the modified form, but the present disclosure is not limited to the embodiment and the modified form, and it goes without saying that it can be appropriately changed and applied within the scope not departing from the gist thereof.

Claims

1. An electricity storage device, wherein, the electricity storage device includes: a housing having a metal housing component including a valve hole; a metal safety valve component including a pressure release type safety valve portion that ruptures and opens when the internal pressure of the housing exceeds the opening pressure; and a valve fixing resin component that is annular and made of resin, is interposed between a hole peripheral portion of the housing component that surrounds the valve hole and a peripheral edge portion of the safety valve component, and is hermetically joined to each of the hole peripheral portion and the peripheral edge portion around their entire circumferences, thereby fixing the safety valve component to the housing component.

2. The electricity storage device according to claim 1, wherein, the valve fixing resin component is made of a thermoplastic resin material, the safety valve component and the valve fixing resin component form a temperature release type safety valve that opens when the resin material softens or melts due to an increase in the temperature of the valve fixing resin component.

3. The electricity storage device according to claim 1 or 2, wherein, the hole peripheral portion of the housing component includes a hole peripheral roughened portion that is an annular shape surrounding the entire circumference of the hole peripheral portion, and nanocolumns having a height of 50 nm or more are formed in a standing manner, where particles derived from the metal forming the housing component are combined in a bead shape to form columns, the valve fixing resin component is formed by filling a resin material for forming the valve fixing resin component between the standing nanocolumns and hermetically joining to the hole peripheral roughened portion around the entire circumference.

4. The electricity storage device according to claim 1 or 2, wherein, the peripheral edge portion of the safety valve component includes a valve peripheral roughened portion that is an annular shape surrounding the entire circumference of the peripheral edge portion, and nanocolumns having a height of 50 nm or more are formed in a standing manner, where particles derived from the metal forming the safety valve component are combined in a bead shape to form columns, the valve fixing resin component is formed by filling a resin material for forming the valve fixing resin component between the standing nanocolumns and hermetically joining to the valve peripheral roughened portion around the entire circumference.

5. The electricity storage device according to claim 1 or 2, wherein, the safety valve component is made of an aluminum plate having a thickness of 500 μm or less, the safety valve portion is formed by stamping.

6. The electricity storage device according to claim 5, wherein, the housing component is made of an aluminum plate having a thickness of 600 μm or more.

7. The electricity storage device according to claim 5, wherein, the housing component is made of a metal other than aluminum.

8. The electricity storage device according to claim 3, wherein, the peripheral edge portion of the safety valve component includes a valve peripheral roughened portion that is an annular shape surrounding the entire circumference of the peripheral edge portion, and nanocolumns having a height of 50 nm or more are formed in a standing manner, where particles derived from the metal forming the safety valve component are combined in a bead shape to form columns, the valve fixing resin component is formed by filling a resin material for forming the valve fixing resin component between the standing nanocolumns and hermetically joining to the valve peripheral roughened portion around the entire circumference.

9. The electricity storage device according to claim 3, wherein, The safety valve component is made of an aluminum plate with a thickness of 500 μm or less. The safety valve part is formed by stamping.

10. The electrical storage device according to claim 4, wherein The safety valve component is made of an aluminum plate with a thickness of 500 μm or less. The safety valve part is formed by stamping.

11. The electrical storage device according to claim 8, wherein The safety valve component is made of an aluminum plate with a thickness of 500 μm or less. The safety valve part is formed by stamping.

12. The electrical storage device according to claim 9, wherein The housing component is made of an aluminum plate with a thickness of 600 μm or more.

13. The electrical storage device according to claim 10, wherein The housing component is made of an aluminum plate with a thickness of 600 μm or more.

14. The electrical storage device according to claim 11, wherein The housing component is made of an aluminum plate with a thickness of 600 μm or more.

15. The electrical storage device according to claim 9, wherein The housing component is made of a metal other than aluminum.

16. The electrical storage device according to claim 10, wherein The housing component is made of a metal other than aluminum.

17. The electrical storage device according to claim 11, wherein The housing component is made of a metal other than aluminum.

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