Battery and battery pack

Abstract

A battery includes a charge-discharge body, an outer body, an electrode terminal, and a sealing body. The electrode terminal includes a connection terminal (321) electrically connected to the charge-discharge body, and an external terminal (322) having an insertion hole (322a) into which the connection terminal (321) is inserted. The external terminal (322) includes a first member (322x) laser-bonded to the connection terminal (321), and a second member (322y) solid-phase-bonded to the first member (322x). The connection terminal (321) includes a head portion (321a) inserted into the insertion hole (322a) of the external terminal (322). The sealing body includes a sealing portion (flange portion (632)) held between the head portion (321a) of the connection terminal (321) and the outer body (cover (420)). The diameter of an annular laser-bonded portion (323) in which an inner edge of the insertion hole (322a) of the external terminal (322) and an outer edge of the head portion (321a) of the connection terminal (321) are laser-bonded is greater than the maximum diameter of a portion of the sealing portion (flange portion (632)) that contacts the head portion (321a).

Description

Technical Field

[0001] This invention relates to batteries and battery packs. Background Technology

[0002] Previously, electrode terminals were known to be formed by solid-state bonding of two or more components (see, for example, Patent Document 1).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent document 1: Japanese Patent Application Publication No. 2016-207510. Summary of the Invention

[0006] The problem the invention aims to solve

[0007] In the case where a second component is solid-state bonded to a first component, and another component is further laser-bonded to the second component to form an electrode terminal, a battery and battery pack that can suppress damage to the laser-bonded portion are required.

[0008] Technical means for solving problems

[0009] The battery includes: a charging / discharging element; an outer casing housing the charging / discharging element; electrode terminals penetrating the outer casing and electrically connected to the charging / discharging element; and a sealing body insulating and sealing the outer casing and the electrode terminals. The electrode terminals include: a connecting terminal comprising a first metal and electrically connected to the charging / discharging element; and an external terminal having an insertion hole for insertion of the connecting terminal and contacting the outer edge of the connecting terminal. The external terminal includes: a first component comprising the first metal and laser-bonded to the connecting terminal; and a second component comprising a second metal of a different material from the first metal, stacked on the first component and solidly bonded to the first component. The connecting terminal includes: a head inserted into the insertion hole of the external terminal; and an insertion portion protruding from the head into the charging / discharging element and penetrating a through hole in the outer casing. The sealing body includes a sealing portion sandwiched between the head of the connecting terminal and the outer casing. The laser-bonded portion, formed by laser bonding the inner edge of the insertion hole of the external terminal and the outer edge of the head of the connecting terminal, is annular along the inner edge of the insertion hole. The diameter of the annular laser-bonded portion is larger than the maximum diameter of the portion of the sealing portion that contacts the head.

[0010] The battery pack has the battery and a busbar that engages with the electrode terminals.

[0011] Invention Effects

[0012] According to the present invention, a battery and battery pack that can suppress damage to laser-bonded joints can be obtained. Attached Figure Description

[0013] Figure 1 This is a perspective view of the battery pack 1 according to the first embodiment.

[0014] Figure 2 It means Figure 1 A three-dimensional view of the battery pack 1 with the gas passage 61 removed.

[0015] Figure 3 It means Figure 1 A top view of the battery pack 1 with the busbar retainer 34 removed.

[0016] Figure 4 This is a perspective view showing the state of a portion of the components of the holding unit 20 after being decomposed along the width direction Y and the stacking direction X for multiple batteries 10 and holding units 20.

[0017] Figure 5 It means from Figure 4 A perspective view of the state after removing the first side plate 26P, the second side plate 26Q and the fastening bolts 27, and decomposing the components of the battery 10 and the holding unit 20 along the stacking direction X.

[0018] Figure 6 This is a three-dimensional view showing the busbar unit 30, the voltage detection unit 40, and the temperature measurement unit 50.

[0019] Figure 7 This is a perspective view of the battery 10 according to the first embodiment.

[0020] Figure 8 This is a three-dimensional view showing the components surrounding the negative terminal 320 of the battery 10 in cross-section.

[0021] Figure 9 It means Figure 8 A side view of the constituent parts.

[0022] Figure 10 This is a three-dimensional view showing the components surrounding the positive terminal 310 of the battery 10 in cross-section.

[0023] Figure 11 It means Figure 10 A side view of the constituent parts.

[0024] Figure 12 This is a three-dimensional view showing the partial disassembly of battery 10.

[0025] Figure 13 This is a three-dimensional view showing the charging and discharging body 100 of the battery 10.

[0026] Figure 14 Represented by cross section Figure 13 A side view of a portion of the charging / discharging body 100.

[0027] Figure 15 This is a side view of a portion of the charge / discharge body 700, showing a modified example in cross-section.

[0028] Figure 16 This is a perspective view showing the components surrounding the negative terminal 320 of the battery 10 after disassembly.

[0029] Figure 17 This is a perspective view showing the components surrounding the rupture valve 430 and sealing plug 440 of the battery 10 after disassembly.

[0030] Figure 18 This is a perspective view showing the components surrounding the positive terminal 310 of the battery 10 after disassembly.

[0031] Figure 19 This is a side view showing the negative terminal 320 and its surrounding components in the first embodiment.

[0032] Figure 20 It is an enlarged representation Figure 19 Side view of area F20.

[0033] Figure 21 It is an enlarged representation Figure 20 Side view of region F21.

[0034] Figure 22 This is a side view showing an enlarged cross-section of the negative terminal 1120 and its surrounding components in a modified example 1 of the first embodiment.

[0035] Figure 23 This is a side view showing an enlarged cross-section of the negative terminal 1220 and its surrounding components in a modified example 2 of the first embodiment.

[0036] Figure 24 This is a side view showing an enlarged cross-section of the negative terminal 1320 and its surrounding components in the second embodiment.

[0037] Figure 25 This is a side view showing an enlarged cross-section of the negative terminal 1420 and its surrounding components in the third embodiment.

[0038] Figure 26 This is a side view showing an enlarged cross-section of the negative terminal 1520 and its surrounding components in the fourth embodiment. Detailed Implementation

[0039] Embodiments for carrying out the present invention will now be described with reference to the accompanying drawings. To facilitate understanding of each embodiment, the size or proportion of the constituent parts may be exaggerated in the drawings. In each drawing, the same reference numerals are used for the same components. In each drawing, arrows indicate the stacking direction X, width direction Y, and height direction Z of the battery pack 1. However, in each drawing, the stacking direction X, width direction Y, and height direction Z of the battery pack 1 represent relative positional relationships within the same drawing. That is, when the battery pack 1 is rotated 180 degrees so that the upper and lower surfaces are reversed, or when the battery pack 1 is rotated 90 degrees so that the upper surface is positioned as a side, the stacking direction X, width direction Y, and height direction Z of the battery pack 1 will change. In each drawing, the threads on the outer peripheral surface of the fastening bolt and the thread grooves on the inner peripheral surface of the insert nut are omitted. In each drawing, arrows indicate the long side direction A, short side direction B, and height direction Z of the battery 10. In each drawing, the long side direction A, short side direction B, and height direction Z of the battery 10 represent relative positional relationships within the same drawing. That is, when the battery 10 is rotated 180 degrees so that the upper and lower surfaces are reversed, or when the battery 10 is rotated 90 degrees so that the upper surface is used as the side, the long side direction A, the short side direction B, and the height direction Z of the battery 10 will change.

[0040] (The configuration of battery pack 1 in the first embodiment)

[0041] The following reference Figures 1 to 22 The configuration of the battery pack 1 in the first embodiment will be described.

[0042] Figure 1 This is a perspective view of the battery pack 1 according to the first embodiment. Figure 2 It means Figure 1 A three-dimensional view of the battery pack 1 with the gas passage 61 removed. Figure 3 It means Figure 1 A top view of the battery pack 1 with the busbar retainer 34 removed. Figure 4 This is a perspective view showing the state of a portion of the components of the holding unit 20 after being decomposed along the width direction Y and the stacking direction X for multiple batteries 10 and holding units 20. Figure 5 It means from Figure 4 A perspective view of the state after removing the first side plate 26P, the second side plate 26Q and the fastening bolts 27, and decomposing the components of the battery 10 and the holding unit 20 along the stacking direction X. Figure 6 This is a three-dimensional view showing the busbar unit 30, the voltage detection unit 40, and the temperature measurement unit 50.

[0043] Figure 7 This is a perspective view of the battery 10 according to the first embodiment. Figure 8This is a three-dimensional view showing the components surrounding the negative terminal 320 of the battery 10 in cross-section. Figure 9 It means Figure 8 A side view of the constituent parts. Figure 10 This is a three-dimensional view showing the components surrounding the positive terminal 310 of the battery 10 in cross-section. Figure 11 It means Figure 10 A side view of the constituent parts. Figure 12 This is a three-dimensional view showing the partial disassembly of battery 10. Figure 13 This is a three-dimensional view showing the charging and discharging body 100 of the battery 10. Figure 14 Represented by cross section Figure 13 A side view of a portion of the charging / discharging body 100. Figure 15 This is a side view of a portion of the charge / discharge body 100, showing a modified example in cross-section. Figure 16 This is a perspective view showing the components surrounding the negative terminal 320 of the battery 10 after disassembly. Figure 17 This is a perspective view showing the components surrounding the rupture valve 430 and sealing plug 440 of the battery 10 after disassembly. Figure 18 This is a perspective view showing the components surrounding the positive terminal 310 of the battery 10 after disassembly.

[0044] (Composition of battery pack 1)

[0045] Battery pack 1 may be configured, for example, as a power source for operating an electric motor that powers the vehicle. Battery pack 1 may also be configured, for example, as a power source for operating electrical equipment mounted in the vehicle.

[0046] like Figure 1 As shown, the battery pack 1 includes a plurality of batteries 10, a holding unit 20 for holding the plurality of batteries 10, and a busbar unit 30 for electrically connecting the plurality of batteries 10. Additionally, the battery pack 1 includes a voltage detection unit 40 for detecting the voltage of the batteries 10, a temperature measurement unit 50 for measuring the temperature of the batteries 10, and an exhaust unit 60 for discharging gases emitted from the batteries 10. The configuration of the battery pack 1 will be described below.

[0047] (The composition of battery 10 in battery pack 1)

[0048] The following reference Figures 1 to 5 as well as Figures 7 to 18 Explain the composition of battery 10.

[0049] (Composition of battery 10)

[0050] Figures 1 to 5 The battery 10 shown is stacked along the stacking direction X via the holding unit 20. For example... Figure 3 As shown, for example, 20 batteries 10 are stacked. The batteries 10 are, for example, composed of lithium-ion secondary batteries.

[0051] like Figure 5 As shown, the battery 10 is formed in a cuboid shape. A positive terminal 310 and a negative terminal 320 are provided on the upper surface 10a of the battery 10 along the stacking direction X. Figure 5 In this context, the upper surface 10a corresponds to the upper surface of the battery 10. The upper surface 10a is formed in a rectangular shape. The length of the upper surface 10a along the width direction Y of the battery 10 is longer than its length along the stacking direction X of the battery 10. The upper surface 10a and... Figure 1 The busbar units 30 shown are opposite each other. The two side surfaces 10b of the battery 10 along the stacking direction X are orthogonal to the upper surface 10a and opposite to each other. The side surfaces 10b are formed in a rectangular shape. The length of the side surfaces 10b along the height direction Z of the battery 10 is longer than the length along the stacking direction X of the battery 10. The two main surfaces 10c of the battery 10 that are opposite each other in the stacking direction X are in contact with the battery spacers 22 of the holding unit 20, etc.

[0052] The battery 10 includes a charge / discharge body 100 for charging and discharging electricity, a current collector 200 connected to the charge / discharge body 100, electrode terminals 300 connected to the current collector 200, an outer casing 400 for housing or mounting the components of the battery 10, an insulator 500 for insulating the components of the battery 10 from the outer casing 400, and a sealing body 600 for sealing the components of the battery 10 from the outer casing 400.

[0053] (The structure of the charging and discharging body 100 of battery 10)

[0054] The charging and discharging body 100 charges and discharges the electricity. Figures 8 to 14 The charge / discharge body 100 shown includes a positive electrode 110, a negative electrode 120, a separator 130, and an electrolyte 140. The charge / discharge body 100 is constructed by winding constituent components stacked in the order of positive electrode 110, separator 130, negative electrode 120, and separator 130 into a cuboid shape. The charge / discharge body 100 can be constructed by either winding or stacking.

[0055] The positive electrode 110 includes an elongated positive electrode current collector layer 111 and positive electrode active material layers 112 bonded to the two surfaces of the positive electrode current collector layer 111. The positive electrode current collector layer 111 includes a current collector portion 111a and a positive electrode tab 111b. The positive electrode active material layer 112 is bonded to the current collector portion 111a. Figure 14As shown, the positive electrode active material layer 112 faces the entire region along the short side direction of the current collector 111a. A positive electrode tab 111b protrudes from the side edge 111c along the long side direction of the current collector 111a along the short side direction. The positive electrode tab 111b is integrally formed with the current collector 111a. Multiple positive electrode tabs 111b are formed on one current collector 111a. The positive electrode 110 may also be configured such that the positive electrode active material layer 112 is bonded only to one side of the positive electrode current collector layer 111. The positive electrode current collector layer 111 is formed, for example, of aluminum or an aluminum alloy. The positive electrode active material layer 112 contains a positive electrode active material composed of a lithium-containing composite oxide, a binder, and conductive additives. The lithium-containing composite oxide uses, for example, metallic elements such as nickel (Ni), cobalt (Co), and manganese (Mn), as well as lithium (Li).

[0056] The negative electrode 120 includes an elongated negative electrode current collector layer 121 and negative electrode active material layers 122 bonded to the two surfaces of the negative electrode current collector layer 121. The negative electrode current collector layer 121 includes a current collector portion 121a and a negative electrode tab 121b. Figure 14 As shown, the current collector 121a of the negative electrode 120 is wider along its shorter side than the current collector 111a of the positive electrode 110. Within the range of the current collector 121a of the negative electrode 120 along its shorter side, the two ends of the current collector 111a of the positive electrode 110 along its shorter side are separated by a separator 130. A negative electrode active material layer 122 is bonded to the current collector 121a. The negative electrode active material layer 122, for example, faces the entire region of the current collector 121a along its shorter side. A negative electrode tab 121b protrudes from the side edge 121c of the current collector 121a along its longer side along its shorter side. When stacked with the positive electrode 110 across the separator 130, the negative electrode tab 121b and the positive electrode tab 111b of the positive electrode 110 protrude in the same direction. With the positive electrode 110 stacked with the separator 130 in between, the negative electrode tab 121b is separated from the positive electrode tab 111b of the positive electrode 110. The negative electrode tab 121b is integrally formed with the current collector 121a. Multiple negative electrode tabs 121b are formed on one current collector 121a. The negative electrode 120 may also be configured such that a negative electrode active material layer 122 is bonded only to one side of the negative electrode current collector layer 121. The negative electrode current collector layer 121 is, for example, formed of copper or a copper alloy. The negative electrode active material layer 122 contains a negative electrode active material made of a carbon-based material, a binder, and conductive additives. For example, graphite is used as the carbon-based material.

[0057] The separator 130 insulates the positive electrode 110 from the negative electrode 120 while allowing lithium ions to pass through. The separator 130 is formed in an elongated strip shape. Figure 14As shown, the diaphragm 130 has a longer width along its short side compared to the current collector 111a of the positive electrode 110 and the current collector 121a of the negative electrode 120. Within the short side of the diaphragm 130, both ends of the current collector 111a of the positive electrode 110 and both ends of the current collector 121a of the negative electrode 120 are located therein. The diaphragm 130 is made of a porous material. The diaphragm 130 may be made of polyethylene (PE) or polypropylene (PP). An insulating component may also be used instead of the diaphragm 130. The insulating component may be located on the side of the positive electrode 110 opposite to the negative electrode 120. An insulating component may also be located on the side of the negative electrode 120 opposite to the positive electrode 110. A heat-resistant insulating component may also be used. In this configuration, the diaphragm 130 is not necessary.

[0058] Electrolyte 140 allows lithium ions to flow between the positive electrode 110 and the negative electrode 120. Electrolyte 140 is also called an electrolyte. Electrolyte 140 contains a solvent and a solute. Additives may also be included in electrolyte 140. The solvent may include, for example, an organic solvent. Examples of organic solvents used include carbonates such as ethylene carbonate. The solute may include, for example, a lithium salt. Examples of lithium salts used include lithium hexafluorophosphate (LiPF6).

[0059] The following reference Figure 15 The following describes a modified example of the charge / discharge body 100: the charge / discharge body 700. The configuration of the positive electrode 710 of the charge / discharge body 700 differs from that of the positive electrode 110 of the charge / discharge body 100. In the configuration of the charge / discharge body 700, the same reference numerals are used for configurations identical to those in the charge / discharge body 100, and their descriptions are omitted. The positive electrode active material layer 711 of the charge / discharge body 700 faces the portion of the current collector 111a except for the two ends along the short side direction. The heat-resistant insulating layer 712 of the charge / discharge body 700 is bonded to the two ends of the current collector 111a along the short side direction and to the base portion of the positive electrode tab 111b.

[0060] (The structure of the current collector 200 of battery 10)

[0061] The current collector 200 is connected to the charging / discharging body 100. The current collector 200 is also called a current collector plate. Figures 8 to 11 , Figure 16 and Figure 18 The current collector 200 shown includes a positive current collector plate 210 and a negative current collector plate 220.

[0062] The positive current collector 210 connects the positive electrode tab 111b of the charging / discharging body 100 to the positive terminal 310. The positive current collector 210 includes a cuboid plate-shaped base 210a and an insertion hole 210b penetrating the base 210a. The insertion portion 310b of the positive terminal 310 is inserted into the insertion hole 210b of the positive current collector 210. The positive current collector 210 is, for example, formed of aluminum or an aluminum alloy.

[0063] The negative current collector 220 enables the negative electrode tab 121b of the charging / discharging body 100 to conduct electricity with the negative terminal 320. The negative current collector 220 includes a cuboid plate-shaped base 220a and an insertion hole 220b penetrating the base 220a. The insertion portion 320b of the negative terminal 320 is inserted into the insertion hole 220b of the negative current collector 220. The negative current collector 220 is formed, for example, of copper or a copper alloy.

[0064] (The configuration of electrode terminals 300 of battery 10)

[0065] Electrode terminal 300 is connected to current collector 200. Figures 7 to 12 , Figure 16 and Figure 18 The electrode terminal 300 shown includes a positive terminal 310 and a negative terminal 320.

[0066] Positive extreme 310, for example Figure 11 It is connected to the positive current collector 210 as shown. Figure 10 , Figure 11 and Figure 18 As shown, the positive terminal 310 includes a cuboid plate-shaped base 310a, and extends from the base 310a towards... Figure 10 The cylindrical insertion portion 310b protruding below, and the portion extending from the outer periphery of the insertion portion 310b towards... Figure 10 The lower part has a protruding cylindrical joint 310c. The base 310a contacts the base 620a of the positive electrode side second washer 620. The insertion part 310b is inserted into the insertion hole 620b of the positive electrode side second washer 620, the positive electrode side insertion hole 420a of the cover 420, the insertion hole 520b of the positive electrode side insulating plate 520, and the insertion hole 210b of the positive electrode current collector 210. Figure 11 and Figure 18 As shown, the joint 310c protrudes downward from the insertion hole 210b of the positive current collector plate 210 and expands radially outward to engage with the positive current collector plate 210. That is, the joint 310c is riveted to the positive current collector plate 210. Furthermore, the joint 310c is welded to the positive current collector plate 210. The positive terminal 310 is, for example, formed of aluminum or an aluminum alloy.

[0067] (Composition of negative terminal 320 (electrode terminal))

[0068] The following reference Figure 8 , Figure 9 , Figure 16 , Figure 19 and Figure 20 Explain the composition of the negative extreme 320. Figure 19 This is a side view showing the negative terminal 320 and its surrounding components in the first embodiment. Figure 20 yes Figure 19 A magnified view of region F20. The negative terminal 320 corresponds to the electrode terminal.

[0069] For example, negative extreme 320 Figure 9 It is connected to the negative current collector 220 as shown. Figure 9 and Figure 16 As shown, the negative terminal 320 includes a cuboid plate-shaped base 320a, and extending from the base 320a towards... Figure 9 The cylindrical insertion portion 320b protruding below, and the portion extending from the outer periphery of the insertion portion 320b towards... Figure 9 The lower part has a protruding cylindrical joint 320c. The base 320a contacts the base 640a of the second washer 640 on the negative electrode side. The insertion part 320b is inserted into the insertion hole 640b of the second washer 640 on the negative electrode side, the insertion hole 420b of the cover 420 on the negative electrode side, the insertion hole 530b of the insulating plate 530 on the negative electrode side, and the insertion hole 220b of the current collector plate 220. Figure 9 and Figure 16 As shown, the joint portion 320c protrudes downward from the insertion hole 220b of the negative electrode current collector plate 220 and expands radially outward to join with the negative electrode current collector plate 220. That is, the joint portion 320c is riveted to the negative electrode current collector plate 220. Furthermore, the joint portion 320c is welded to the negative electrode current collector plate 220.

[0070] The negative terminal 320 includes a connection terminal 321 and an external terminal 322. The following mainly refers to... Figure 20 This section details the construction of the negative terminal 320. Figure 20 The lower side indicates Figure 19 A magnified view of region F20. Figure 20 The upper side shows a partially enlarged view of the laser-engaged portion 323, which includes the connecting terminal 321 and the external terminal 322. The external terminal 322 includes a first component 322x and a second component 322y. The connecting terminal 321 and the first component 322x of the external terminal 322 are formed, for example, of copper or a copper alloy. The second component 322y of the external terminal 322 is formed, for example, of aluminum or an aluminum alloy.

[0071] In the external terminal 322, the first component 322x and the second component 322y are joined by solid-state bonding. Solid-state bonding includes press-fitting, diffusion bonding, friction press-fitting, and ultrasonic bonding. In this embodiment, press-fitting-based solid-state bonding is used as an example. Press-fitting includes hot press-fitting and room temperature (cold) press-fitting. In hot press-fitting, the first component 322x and the second component 322y are pressed together with relatively high pressure while the first component 322x and the second component 322y are heated. In room temperature press-fitting, the first component 322x and the second component 322y are pressed together with relatively high pressure.

[0072] The mating surface 322z of the first component 322x and the second component 322y has a surface orthogonal to the height direction Z of the battery 10 and a surface parallel to the height direction Z of the battery 10.

[0073] like Figure 8 , Figure 9 and Figure 16 As shown, the external terminal 322 is formed in the shape of a rectangular plate. In this embodiment, the external terminal 322 is formed of a so-called embedded composite material. The composite material used as the external terminal 322 is formed by solid-state bonding of the first component 322x and the second component 322y with a copper-based material embedded in a recess formed in the second component 322y, which is made of a rectangular plate-shaped aluminum-based material. It should be noted that this embodiment illustrates an example of forming the external terminal 322 with an embedded composite material, but the external terminal 322 can also be formed with an edge-type composite material. In this case, solid-state bonding is performed with a copper-based material embedded in a recess formed at the corner of the rectangular plate-shaped aluminum-based material.

[0074] like Figure 20 As shown, an insertion hole 322a extending through the height direction Z of the battery 10 is formed in the external terminal 322. A connection terminal 321 is inserted into the insertion hole 322a. At least around the insertion hole 322a, the external terminal 322 stacks a first component 322x and a second component 322y along the height direction Z. Around the insertion hole 322a, the second component 322y is located further away from the charging / discharging body 100 than the first component 322x.

[0075] The insertion hole 322a includes a large-diameter circular hole 322a1 and a small-diameter circular hole 322a2 with an inner diameter smaller than that of the large-diameter hole 322a1. The large-diameter hole 322a1 is located on the side of the manifold 32. Figure 20 The upper side). Small diameter hole 322a2 is located on the side of cover 420 ( Figure 20 (Lower side). The large-diameter hole 322a1 and the small-diameter hole 322a2 are concentrically arranged. A stepped surface 322a3 is formed between the large-diameter hole 322a1 and the small-diameter hole 322a2, which is a surface orthogonal to the height direction Z.

[0076] On the end face of the external terminal 322 on the busbar 32 side, there is a shape that is consistent with the busbar 32 (see reference). Figure 19 The terminal face 322b of the external terminal 322 is in contact with the busbar 32 side. The end face of the external terminal 322 on the busbar 32 side corresponds to the end face of the second component 322y of the external terminal 322 on the busbar 32 side. The end face of the external terminal 322 on the busbar 32 side is the end face of the external terminal 322 in the height direction Z. Figure 20 The end face of the upper and lower end faces of the device, which is opposite to the side on which the charging / discharging body 100 is disposed.

[0077] The connection terminal 321 includes a head 321a that forms part of the base 320a. Additionally, the connection terminal 321 includes the aforementioned insertion portion 320b and engagement portion 320c. The insertion portion 320b protrudes from the head 321a toward the charging / discharging body 100 and passes through the negative-side insertion hole (through hole) 420b of the cover 420.

[0078] like Figure 8 and Figure 16 As shown, the head 321a is formed in a roughly circular plate shape. Figure 20 As shown, the head 321a is inserted into the insertion hole 322a of the external terminal 322. The end face of the head 321a on the busbar 32 side, that is, the end face 321a1 on the busbar 32 side connecting the terminal 321, is located closer to the cover 420 side than the terminal face 322b of the external terminal 322. Figure 20 The end face 321a1 on the busbar 32 side of the connecting terminal 321 is the end face of the connecting terminal 321 in the height direction Z (the lower side). Figure 20 The end face of the upper and lower end faces of the device, which is opposite to the side on which the charging / discharging body 100 is disposed.

[0079] The head 321a includes a large-diameter portion 321a2 that inserts into a large-diameter hole 322a1 and a small-diameter portion 321a3 that inserts into a small-diameter hole 322a2. The large-diameter portion 321a2 and the small-diameter portion 321a3 are concentrically arranged. The outer diameter of the small-diameter portion 321a3 is smaller than the outer diameter of the large-diameter portion 321a2. A stepped surface 321a4, which is orthogonal to the height direction Z, is formed between the large-diameter portion 321a2 and the small-diameter portion 321a3.

[0080] On the inner peripheral surface of the insertion hole 322a of the external terminal 322 and the outer peripheral surface of the head 321a of the connecting terminal 321, respectively, there are fitting recesses 322a4 and fitting protrusions 321a5 that fit and contact each other.

[0081] The large-diameter portion 321a2 of the head 321a of the connecting terminal 321 includes a fitting protrusion 321a5 that protrudes radially outward from the connecting terminal 321. In other words, the outer periphery of the large-diameter portion 321a2 is formed as the fitting protrusion 321a5. The large-diameter hole 322a1 of the insertion hole 322a of the external terminal 322 includes a fitting recess 322a4 that is recessed radially outward from the insertion hole 322a. In other words, the outer periphery of the large-diameter hole 322a1 is formed as the fitting recess 322a4.

[0082] The mating recess 322a4 of the external terminal 322 is a recessed portion that is recessed opposite to the outer peripheral surface of the head 321a of the connecting terminal 321. The mating protrusion 321a5 of the connecting terminal 321 is a protrusion that protrudes toward the external terminal 322. The mating protrusion 321a5 and the mating recess 322a4 are in contact at least in the stacking direction (height direction Z) of the first component 322x and the second component 322y. That is, the stepped surface 322a3 of the mating recess 322a4 is in contact with the stepped surface 321a4 of the mating protrusion 321a5.

[0083] Therefore, the positions of the external terminal 322 and the connecting terminal 321 in the height direction Z are defined. Thus, the fitting protrusion 321a5 and the fitting recess 322a4 can be used to position the external terminal 322 and the connecting terminal 321 in the height direction Z.

[0084] The negative terminal 320 is formed before being mounted on the cover 420 along with other components. The external terminal 322 is formed by forming an insertion hole 322a in a rectangular flat composite material of an embedded or edge-type shape. A fitting recess 322a4 is provided on the second component 322y of the external terminal 322. Therefore, the insertion hole 322a and the fitting recess 322a4 can be formed simultaneously by hole processing such as cold forging or stamping, resulting in good manufacturability. It should be noted that the external terminal 322 can also be formed by solid-state bonding the first component 322x, to which the insertion hole 322a is pre-formed, with the second component 322y.

[0085] Connection terminal 321 from Figure 20 The upper side of the insertion hole 322a of the external terminal 322 is inserted. The external terminal 322 and the connecting terminal 321 are positioned by contacting the stepped surface 321a4 of the fitting protrusion 321a5 with the stepped surface 322a3 of the fitting recess 322a4. By positioning, the lower surface of the outer periphery of the head 321a of the connecting terminal 321 is flush with the lower surface of the external terminal 322. The inner engaging portion 321a6 of the connecting terminal 321 and the outer engaging portion 322a5 of the external terminal 322 mate with each other. The inner engaging portion 321a6 corresponds to the lower end of the outer periphery of the head 321a of the connecting terminal 321. The outer engaging portion 322a5 corresponds to the opening edge of the lower end of the insertion hole 322a of the external terminal 322.

[0086] Towards the boundary surface between the inner joint 321a6 and the outer joint 322a5, from Figure 20 A laser is irradiated from the lower side to laser-joint the external terminal 322 with the connecting terminal 321. It should be noted that the configuration relationship between the connecting terminal 321 and the external terminal 322 in the laser joining process is... Figure 20 The orientations are reversed. Thus, a laser-bonded portion 323 is formed at the contact interface between the small-diameter hole 322a2 of the external terminal 322 and the small-diameter portion 321a3 of the connecting terminal 321. Specifically, the laser-bonded portion 323 is formed in an annular shape along the inner edge of the insertion hole 322a. The outer bonding portion 322a5 and the inner bonding portion 321a6 are integrated by laser bonding. Thus, the external terminal 322 and the connecting terminal 321 are integrated, thereby forming the negative terminal 320. The negative terminal 320 is then mounted on the cover 420 along with other components.

[0087] The end face 321a1 of the connecting terminal 321 is located closer to the charging / discharging body 100 than the opening end face of the busbar 32 on the insertion hole 322a. Therefore, a downwardly recessed circular recess 320d is formed on the upper surface of the negative terminal 320. The bottom surface of the recess 320d is formed by the end face 321a1 of the connecting terminal 321, and the side surface of the recess is formed by the inner peripheral surface of the insertion hole 322a of the external terminal 322. The end face 321a1 of the connecting terminal 321 is located closer to the charging / discharging body 100 than the terminal face 322b of the external terminal 322. Therefore, when the busbar 32 is soldered to the negative terminal 320, interference between the connecting terminal 321 and the busbar 32 can be prevented. Thus, the busbar 32 and the external terminal 322 can be lap-welded with the busbar 32 abutting against the terminal face 322b of the external terminal 322.

[0088] The surface of the mating surface 322z of the first component 322x and the second component 322y, which is orthogonal to the height direction Z, is located to the side of the small-diameter portion 321a3 of the connecting terminal 321. The component of the external terminal 322 that is laser-bonded to the connecting terminal 321 is the first component 322x, which contains the same metal as the connecting terminal 321. The outer edge of the small-diameter portion 321a3 of the head 321a of the connecting terminal 321 contacts the inner edge of the small-diameter hole 322a2 of the external terminal 322.

[0089] By laser bonding the inner edge of the insertion hole 322a of the external terminal 322 to the outer edge of the head 321a of the connecting terminal 321, an annular laser bonding portion 323 is formed along the inner edge of the insertion hole 322a. The dimension (depth) of the laser bonding portion 323 in the height direction Z is smaller than the thickness of the first component 322x.

[0090] A directional pattern is formed on the lower surface of the head 321a. Figure 20 The lower part has a protruding circular pressing protrusion 321d. The outer diameter of the pressing protrusion 321d is larger than the outer diameter of the insertion part 320b and smaller than the outer diameter of the small diameter part 321a3. Figure 20 Press down on the negative electrode side, first washer 630.

[0091] The negative terminal 320 is riveted to the negative current collector plate 220 while the first washer 630 on the negative side is elastically deformed. The connection terminal 321 is electrically connected to the charging and discharging body 100 of the battery 10 via the negative current collector plate 220.

[0092] (The structure of the outer casing 400 of battery 10)

[0093] The outer casing 400 is a component that houses or installs the battery 10. Figures 7 to 12 as well as Figures 16 to 18 The outer casing 400 shown includes a container 410, a cap 420, a rupture valve 430, and a sealing plug 440.

[0094] Container 410 houses the charging / discharging body 100, etc. Container 410 is constructed of a rectangular metal can. Container 410 includes an opening 410a along its long side and a receiving portion 410b communicating with the opening 410a. Container 410 is made of, for example, aluminum or an aluminum alloy.

[0095] The cap 420 seals the opening 410a of the container 410. The container 410 is formed of a long, plate-shaped metal plate. A positive electrode insertion hole 420a, consisting of a circular through hole, is formed at one end of the cap 420 along its long side A. The insertion portion 310b of the positive electrode 310 and the first positive electrode washer 610 of the sealing body 600 are inserted into the positive electrode insertion hole 420a. A negative electrode insertion hole 420b, consisting of a circular through hole, is formed at the other end of the cap 420 along its long side A. The insertion portion 320b of the negative electrode 320 and the first negative electrode washer 630 of the sealing body 600 are inserted into the negative electrode insertion hole 420b.

[0096] like Figure 16 As shown, a circular recess 421 is formed on the upper surface of the cover 420, surrounding the negative electrode insertion hole 420b. An annular pressing protrusion 422 protrudes upward from the bottom surface of the recess 421 within the recess 421. The circular recess 421, the annular pressing protrusion 422, and the negative electrode insertion hole 420b are concentrically arranged. The recess 421 and the pressing protrusion 422 are formed by stamping a flat plate. Figure 20 As shown, the upper end face of the pressing protrusion 422 is located closer to the busbar 32 (i.e., the upper side) than the upper surface of the cover 420 that abuts against the second washer 640 on the negative electrode side.

[0097] like Figure 17 As shown, a liquid injection insertion hole 420c, consisting of a circular through hole, is formed between the positive electrode side insertion hole 420a and the negative electrode side insertion hole 420b of the cap 420. The insertion portion 440b of the sealing plug 440 is inserted into the liquid injection insertion hole 420c. The cap 420 is welded to the container 410. The cap 420 is, for example, made of aluminum or an aluminum alloy.

[0098] like Figure 17 As shown, a rupture valve 430 is disposed on the cover 420. The rupture valve 430 ruptures outwards from the battery when the internal pressure of the battery 10 reaches a predetermined value, reducing the internal pressure of the battery 10 to atmospheric pressure. The rupture valve 430 is, for example, circular. The rupture valve 430 is thinner than the cover 420. A groove is formed on the rupture valve 430 as a rupture reference. The rupture valve 430 and the cover 420 are integrally formed. Alternatively, the rupture valve 430 and the cover 420 can be formed separately and then circumferentially welded relative to the through hole in the cover 420.

[0099] like Figure 12 As shown, the sealing plug 440 has an insertion hole 420c for liquid injection in the sealing cap 420. The sealing plug 440 is formed in a cylindrical shape. Figure 17 As shown, the sealing plug 440 includes a head 440a with a relatively large outer diameter and an insertion portion 440b, which is continuous with the head 440a and has a relatively small outer diameter. The head 440a of the sealing plug 440 is welded to the cap 420. The insertion portion 440b is inserted into an insertion hole 420c for liquid injection. The sealing plug 440 is formed, for example, of aluminum or an aluminum alloy.

[0100] (The structure of the insulator 500 in battery 10)

[0101] The insulator 500 insulates the components of the battery 10 from the outer casing 400. Figures 8 to 11 , Figure 16 and Figure 18 The insulator 500 shown includes an insulating cover 510, a positive-side insulating plate 520, and a negative-side insulating plate 530.

[0102] An insulating cover 510 covers the charging / discharging body 100. The insulating cover 510 exposes one side portion 100a of the charging / discharging body 100 to the outside and covers the portion of the charging / discharging body 100 other than one side portion 100a. The insulating cover 510 is formed, for example, in a pentahedral shape and folded into a box shape. The insulating cover 510 is formed, for example, from polypropylene.

[0103] The positive electrode side insulating plate 520 insulates the positive electrode current collector 210 from the cover 420. The positive electrode side insulating plate 520 includes a cuboid plate-shaped base 520a, an insertion hole 520b penetrating the base 520a, and a protrusion 520c annularly surrounding the side edge of the base 520a and protruding in a direction away from the cover 420. The positive electrode current collector 210 is housed within the space formed by the base 520a and the protrusion 520c in the positive electrode side insulating plate 520. The insertion portion 310b of the positive terminal 310 is inserted into the insertion hole 520b. The positive electrode side insulating plate 520 is formed, for example, of an insulating resin.

[0104] A negative electrode side insulating plate 530 is disposed between the negative electrode current collector 220 and the cover 420. The negative electrode side insulating plate 530 insulates the negative electrode current collector 220 from the cover 420. The negative electrode side insulating plate 530 includes a cuboid plate-shaped base 530a, an insertion hole 530b penetrating the base 530a, and a protrusion 530c annularly surrounding the side edge of the base 530a and protruding in a direction away from the cover 420. The negative electrode current collector 220 is housed in the space formed by the base 530a and the protrusion 530c in the negative electrode side insulating plate 530. The insertion portion 320b of the negative terminal 320 and the cylindrical portion 631 of the negative electrode side first washer 630 are inserted into the insertion hole 530b. The negative electrode side insulating plate 530 is formed, for example, of insulating resin.

[0105] like Figure 20 As shown, the insertion hole 530b of the negative electrode side insulating plate 530 includes a large-diameter hole 530b1 for inserting the lower end of the cylindrical portion 631 of the negative electrode side first washer 630, and a small-diameter hole 530b2 for inserting the insertion portion 320b of the connecting terminal 321. The inner diameter of the large-diameter hole 530b1 is larger than the outer diameter of the cylindrical portion 631 of the negative electrode side first washer 630. The inner diameter of the small-diameter hole 530b2 is smaller than the inner diameter of the large-diameter hole 530b1, and larger than the outer diameter of the insertion portion 320b of the connecting terminal 321. A stepped surface 530b3, which is a surface orthogonal to the height direction Z, is formed between the large-diameter hole 530b1 and the small-diameter hole 530b2. The stepped surface 530b3 is opposite to the lower end face of the cylindrical portion 631 of the negative electrode side first washer 630 in the height direction Z.

[0106] In this configuration, an annular protrusion 530d is formed that projects radially inward from the inner circumferential surface of the large-diameter hole 530b1. Therefore, in this embodiment, compared to the case where the protrusion 530d is not formed, the creepage distance between the cover 420 and the negative current collector 220 can be increased. As a result, short circuits between the cover 420 and the negative current collector 220 can be effectively suppressed.

[0107] A gap is formed between the inner circumferential surface of the large-diameter hole 530b1 of the negative electrode side insulating plate 530 and the outer circumferential surface of the cylindrical portion 631 of the negative electrode side first washer 630. A gap is formed between the stepped surface 530b3 of the negative electrode side insulating plate 530 and the lower end face of the cylindrical portion 631 of the negative electrode side first washer 630. A gap is formed between the inner circumferential surface of the small-diameter hole 530b2 of the negative electrode side insulating plate 530 and the outer circumferential surface of the insertion portion 320b of the connecting terminal 321.

[0108] (The structure of the sealing body 600 of battery 10)

[0109] The sealing body 600 seals the components of the battery 10 with the outer casing 400. Figures 8 to 11 , Figure 16 and Figure 18 The sealing body 600 shown includes a first gasket 610 on the positive electrode side, a second gasket 620 on the positive electrode side, a first gasket 630 on the negative electrode side, and a second gasket 640 on the negative electrode side.

[0110] The first gasket 610 on the positive electrode side seals the positive current collector 210 to the cover 420, thereby sealing the outer casing 400. The first gasket 610 on the positive electrode side is cylindrical. Figure 18 As shown, the first washer 610 on the positive electrode side includes a first insertion portion 610a with a relatively large outer diameter, a second insertion portion 610b that is continuous with the first insertion portion 610a and has a relatively small outer diameter, and an insertion hole 610c that passes through the first insertion portion 610a and the second insertion portion 610b. Figure 11 As shown, the first washer 610 on the positive side is disposed between the positive terminal 310 and the positive current collector 210. The first insertion part 610a is inserted. Figure 18 The insertion hole 520b of the positive electrode side insulating plate 520 is shown. The second insertion part 610b is inserted. Figure 18 The positive electrode side insertion hole 420a of the cover 420 and the positive electrode side insertion hole 620b of the second washer 620 are shown. Figure 18 The insertion portion 310b of the positive terminal 310 shown is inserted into the insertion hole 610c. The first washer 610 on the positive terminal side is, for example, formed of rubber with insulating and elastic properties.

[0111] The second washer 620 on the positive side seals the positive terminal 310 while insulating it from the cover 420. For example... Figure 18 As shown, the second gasket 620 on the positive electrode side includes a rectangular plate-shaped base 620a, an insertion hole 620b penetrating the base 620a, and a protrusion 620c annularly surrounding the side edge of the base 620a and protruding in a direction away from the cover 420. In the second gasket 620 on the positive electrode side, a positive terminal 310 is housed within the space formed by the base 620a and the protrusion 620c. The insertion portion 310b of the positive terminal 310 is inserted into the insertion hole 620b. The second gasket 620 on the positive electrode side is formed, for example, of an insulating resin.

[0112] like Figures 19 to 21 As shown, the first negative electrode washer 630 is disposed between the cover 420 and the connecting terminal 321 penetrating the cover 420. The first negative electrode washer 630 seals the outer casing 400 while simultaneously insulating the cover 420 from the negative terminal 320. The first negative electrode washer 630 is, for example, formed of insulating and elastic rubber. The first negative electrode washer 630 is pressed by the cover 420 and the negative terminal 320, and fills the gap between the two components through elastic deformation. Compared to the second negative electrode washer 640 and the negative electrode insulating plate 530, the first negative electrode washer 630 has a lower elastic modulus and is more easily deformed.

[0113] The negative electrode side first washer 630 includes a cylindrical portion 631 and an annular flange portion 632 disposed at one end of the cylindrical portion 631. An insertion hole 630c extending through the negative electrode side first washer 630 in the height direction Z is formed therein. The flange portion 632 protrudes radially outward from the cylindrical portion 631. The cylindrical portion 631 protrudes from the flange portion 632 toward the charging / discharging body 100 and is inserted into the negative electrode side insertion hole 420b. The cylindrical portion 631 is disposed in the gap between the insertion portion 320b of the connecting terminal 321 and the negative electrode side insertion hole 420b of the cover 420. The insertion portion 320b of the connecting terminal 321 is inserted into the insertion hole 630c, and the cylindrical portion 631 is inserted into the negative electrode side insertion hole 420b of the cover 420. The inner peripheral surface of the insertion hole 630c of the cylindrical portion 631 is in close contact with the outer peripheral surface of the insertion portion 320b of the connecting terminal 321. A gap is formed between the outer peripheral surface of the cylindrical part 631 and the inner peripheral surface of the negative electrode side insertion hole 420b of the cover 420.

[0114] A flange portion 632 is disposed between the head 321a of the connecting terminal 321 and the recess 421 of the cover 420. The flange portion 632 includes a small-diameter portion 632a that contacts the lower surface of the head 321a of the connecting terminal 321 and the pressing protrusion 321d, and a large-diameter portion 632b that contacts the bottom surface of the recess 421 of the cover 420 and the pressing protrusion 422. The small-diameter portion 632a and the large-diameter portion 632b are formed concentrically. The outer diameter of the small-diameter portion 632a is smaller than the outer diameter of the large-diameter portion 632b.

[0115] The small diameter portion 632a of the flange portion 632 is pressed against the pressing protrusion 321d of the connecting terminal 321. Figure 20 and Figure 21 It undergoes elastic deformation when pressed down below. Figure 20 and Figure 21 In the diagram, the outline of the small-diameter portion 632a before elastic deformation is indicated by the dashed line DL1. The large-diameter portion 632b of the flange portion 632 is pressed against the pressing protrusion 422 of the cover 420. Figure 20 and Figure 21 It undergoes elastic deformation when pressed on top. Figure 20 and Figure 21 In the diagram, the outline of the large-diameter portion 632b before elastic deformation is indicated by the dashed line DL2. Thus, the flange portion 632 is pressed along the height direction Z (vertical direction in the diagram) by the connecting terminal 321 and the cover 420. Consequently, the flange portion 632 is in close contact with the lower surface of the head 321a of the connecting terminal 321 and the pressing protrusion 321d, and also in close contact with the bottom surface of the recess 421 of the cover 420 and the pressing protrusion 422. As a result, the cover 420 and the negative terminal 320 are properly sealed. Thus, the flange portion 632 is clamped between the head 321a of the connecting terminal 321 and the cover 420, and functions as a sealing portion.

[0116] The second gasket 640 on the negative electrode side seals the negative terminal 320 while insulating it from the cover 420. The second gasket 640 on the negative electrode side is, for example, formed of insulating resin. Figure 16 As shown, the second washer 640 on the negative electrode side includes a rectangular plate-shaped base 640a, an insertion hole 640b penetrating the base 640a, and a protrusion 640c that surrounds the side edge of the base 640a and protrudes in a direction away from the cover 420. In the second washer 640 on the negative electrode side, the base 320a of the negative terminal 320 is housed within the space formed by the base 640a and the protrusion 640c. The flange portion 632 of the first washer 630 on the negative electrode side, which is mounted on the insertion portion 320b of the negative terminal 320, is inserted into the insertion hole 640b.

[0117] like Figure 20 As shown, an annular recess 641 is formed on the upper surface of the base 640a of the second washer 640 on the negative electrode side. The recess 641 is a gap portion that suppresses interference caused by deformation or movement of the connecting terminal 321 and the external terminal 322 in the height direction Z.

[0118] As described above, an annular recess 641 is provided in the second washer 640 on the negative electrode side. Therefore, in this embodiment, compared with the case where the recess 641 is not provided, the contact area between the second washer 640 on the negative electrode side and the negative terminal 320 can be reduced. As a result, when the second washer 640 on the negative electrode side and the first washer 630 on the negative electrode side are sandwiched between the base 320a of the negative terminal 320 and the cover 420, the reaction force acting on the base 320a of the negative terminal 320 from the second washer 640 on the negative electrode side can be reduced.

[0119] It should be noted that when a radially inwardly open recess is provided instead of a recess 641 having an inner side surface 641b, if condensate from the outside enters the recess, the condensate may reach the recess 421 of the cover 420 through the insertion hole 640b. In this embodiment, the second washer 640 on the negative electrode side contacts the base 320a of the negative electrode 320 at a position further radially inward than the inner side surface 641b. Therefore, even if condensate enters the recess 641, it is possible to prevent condensate from reaching the insertion hole 640b.

[0120] The insertion hole 640b of the second washer 640 on the negative electrode side includes a circular large-diameter hole 640b1 and a circular small-diameter hole 640b2 with an inner diameter smaller than that of the large-diameter hole 640b1. The large-diameter portion 632b of the flange portion 632 of the first washer 630 on the negative electrode side is inserted into the large-diameter hole 640b1 of the second washer 640 on the negative electrode side. The small-diameter portion 632a of the flange portion 632 of the first washer 630 on the negative electrode side is inserted into the small-diameter hole 640b2 of the second washer 640 on the negative electrode side. A gap is formed between the inner circumferential surface of the large-diameter hole 640b1 of the second washer 640 on the negative electrode side and the outer circumferential surface of the large-diameter portion 632b of the flange portion 632 of the first washer 630 on the negative electrode side. A gap is formed between the inner circumferential surface of the small diameter hole 640b2 of the second washer 640 on the negative electrode side and the outer circumferential surface of the small diameter portion 632a of the flange portion 632 of the first washer 630 on the negative electrode side.

[0121] As described above, a large-diameter hole 640b1 and a small-diameter hole 640b2 are formed in the second washer 640 on the negative electrode side. Therefore, a stepped portion is formed in the insertion hole 640b of the second washer 640 on the negative electrode side. Furthermore, as described above, a small-diameter portion 632a and a large-diameter portion 632b are formed in the flange portion 632 of the first washer 630 on the negative electrode side. Therefore, a stepped portion is formed on the outer peripheral surface of the flange portion 632 of the first washer 630 on the negative electrode side. Thus, in this embodiment, stepped portions facing each other are formed on the first washer 630 and the second washer 640 on the negative electrode side. Therefore, in this embodiment, compared to the case where no stepped portion is formed, the creepage distance between the cover 420 and the base 320a of the negative terminal 320 can be increased. As a result, short circuits between the cover 420 and the negative terminal 320 can be effectively suppressed.

[0122] The first washer 630 on the negative electrode side is held between the connecting terminal 321 and the cover 420 and undergoes elastic deformation. The second washer 640 on the negative electrode side is held between the connecting terminal 321 and the cover 420, but undergoes almost no elastic deformation. Therefore, with the negative terminal 320 and other components installed on the cover 420, the elastic reaction force acting on the negative terminal 320 from the second washer 640 on the negative electrode side is less than the elastic reaction force acting on the negative terminal 320 from the first washer 630 on the negative electrode side.

[0123] The first washer 630 on the negative electrode side is held between the negative terminal 320 and the cover 420 and undergoes elastic deformation. This appropriately ensures a tight seal between the negative terminal 320 and the cover 420. Furthermore, in this embodiment, as... Figure 19 As shown, the diameter φD of the annular laser junction 323 is larger than the diameter φd of the small-diameter portion 632a of the flange 632 (φD > φd). The diameter φD of the laser junction 323 is equivalent to the diameter of the small-diameter hole 322a2 of the insertion hole 322a, that is, the diameter of the small-diameter portion 321a3 of the head 321a. The diameter φd of the small-diameter portion 632a is equivalent to the maximum diameter of the portion of the flange 632 that contacts the head 321a of the connecting terminal 321.

[0124] When the negative terminal 320 is riveted to the negative current collector plate 220 and assembled onto the cover 420, the upward elastic reaction force from the flange portion 632 of the first washer 630 on the negative side acts on the base portion 320a of the negative terminal 320 (the head 321a of the connecting terminal 321). Here, if the diameter φD of the laser bonding portion 323 is smaller than the diameter φd of the small diameter portion 632a of the flange portion 632, the elastic reaction force of the first washer 630 on the negative side also acts on the external terminal 322. Since the connecting terminal 321 is fixed to the negative current collector plate 220, when the upward force (the elastic reaction force of the first washer 630 on the negative side) acts on the external terminal 322, shear stress is generated in the laser bonding portion 323.

[0125] In contrast, in this embodiment, as described above, the diameter φD of the laser junction 323 is larger than the diameter φd of the small diameter portion 632a of the flange 632. Therefore, the elastic reaction force of the first washer 630 on the negative electrode side acts only on the connecting terminal 321. As a result, shear stress can be prevented from being generated in the laser junction 323 due to the elastic reaction force of the first washer 630 on the negative electrode side.

[0126] It should be noted that, more preferably, the distance (shortest distance) from the central axis of the insertion hole 322a of the external terminal 322 to the inner edge of the annular laser junction 323 is greater than the radius (φd / 2) of the small diameter portion 632a of the flange portion 632 of the first washer 630 on the negative electrode side. In this configuration, the small diameter portion 632a does not contact the laser junction 323. Therefore, the elastic reaction force can be prevented from acting directly on the laser junction 323.

[0127] (The configuration of the holding unit 20 of battery pack 1)

[0128] like Figures 1 to 5 As shown, the holding unit 20 holds multiple batteries 10. Figure 5As shown, the retaining unit 20 includes a first end spacer 21P, a battery spacer 22, and a second end spacer 21Q. Additionally, the retaining unit 20 includes a first end block 23P, a second end block 23Q, an insulating member 24, and an insert nut 25. Furthermore, as... Figure 4 As shown, the retaining unit 20 includes a first side plate 26P, a second side plate 26Q, and a fastening bolt 27. The configuration of the retaining unit 20 will be described below.

[0129] like Figure 5 As shown, a first end spacer 21P is disposed between the first end block 23P and the battery 10. The first end spacer 21P contacts the first battery 10 located on one end side of the 20 stacked batteries 10. This battery 10 is equivalent to Figure 3 The battery 10 is located at the left end. A first end spacer 21P insulates the first end block 23P from the battery 10. The first end spacer 21P covers the first end block 23P and each side of the battery 10 along the width direction Y. The first end spacer 21P covers a portion of the side 10b of the battery 10 along the stacking direction X. The thickness of the first end spacer 21P along the stacking direction X is much smaller than the thickness of the battery 10 along the stacking direction X. The first end spacer 21P is formed of an insulating material.

[0130] like Figure 5 As shown, a battery spacer 22 is disposed between adjacent batteries 10. The battery spacer 22 holds adjacent batteries 10 together and insulates them from each other. The battery spacer 22 covers a portion of each main surface 10c along the width direction Y of adjacent batteries 10 and a portion of each side surface 10b along the stacking direction X of adjacent batteries 10. The thickness of the battery spacer 22 along the stacking direction X is much smaller than the thickness of the batteries 10 along the stacking direction X. The battery spacer 22 is formed of an insulating material.

[0131] like Figure 5 As shown, a second end spacer 21Q is disposed between the battery 10 and the second end block 23Q. The second end spacer 21Q contacts the 20th battery 10 located on the other end side of the stacked 20 batteries 10. This battery 10 is equivalent to Figure 3 The battery 10 is located at the right end. A second end spacer 21Q insulates the battery 10 from the second end block 23Q. The second end spacer 21Q covers the sides of the first end block 23P and the battery 10 along the width direction Y. The second end spacer 21Q covers a portion of the side 10b of the battery 10 along the stacking direction X. The thickness of the second end spacer 21Q along the stacking direction X is much smaller than the thickness of the battery 10 along the stacking direction X. The second end spacer 21Q is formed of an insulating material.

[0132] like Figure 5As shown, the first end block 23P is stacked with the first battery 10 located at one end of the stacked 20 batteries 10, separated by the first end spacer 21P. The first end block 23P extends in the width direction Y, intersecting the stacking direction X of the batteries 10. The first end block 23P is adjacent to and supports the battery 10 located at the end along the stacking direction X. The first end block 23P is formed in a cuboid shape extending in the width direction Y. A fastening bolt 27 is screwed into the first end block 23P. Figure 4 As shown, multiple threaded holes 23Pa are located on the side surface along the width direction Y. (As shown...) Figure 1 As shown, the first end block 23P is fixed to the first side plate 26P by fastening bolts 27. Similarly, the first end block 23P is fixed to the second side plate 26Q by fastening bolts 27. Insertion holes 23Pc for inserting bolts or the like that for fixing the battery pack 1 are formed in the first end block 23P. The first end block 23P is made of, for example, metal or resin.

[0133] like Figure 5 As shown, the second end block 23Q is stacked with the 20th battery 10 located on the other end side of the stacked 20 batteries 10, separated by the second end spacer 21Q. The second end block 23Q extends along the width direction Y of the battery 10. The second end block 23Q is adjacent to and supports the battery 10 located at the end along the stacking direction X. The second end block 23Q is formed into a cuboid shape extending along the width direction Y. Fastening bolts 27 are screwed into the second end block 23Q. Figure 4 As shown, multiple threaded holes on the side surface along the width direction Y. (As...) Figure 1 As shown, the second end block 23Q is fixed to the first side plate 26P by fastening bolts 27. Similarly, the second end block 23Q is fixed to the second side plate 26Q by fastening bolts 27. Insertion holes 23Qc for inserting bolts or the like for fixing the battery pack 1 are formed in the second end block 23Q. The second end block 23Q is made of, for example, metal or resin.

[0134] like Figure 5 As shown, the insulating member 24 is inserted into the first end block 23P. Additionally, the insulating member 24 is inserted into the second end block 23Q. The insulating member 24 is, for example, formed in a cuboid shape. The insulating member 24 is formed of an insulating material.

[0135] The insulating member 24 can also be configured as follows: It can be integrally formed with the first end spacer 21P, or it can be separately formed and then joined to the first end spacer 21P. In this case, a recess for housing the insulating member 24 along the lamination direction X is provided on the surface of the first end block 23P opposite to the first end spacer 21P. Similarly, the insulating member 24 can be integrally formed with the second end spacer 21Q, or it can be separately formed and then joined to the second end spacer 21Q. In this case, a recess for housing the insulating member 24 along the lamination direction X is provided on the surface of the second end block 23Q opposite to the second end spacer 21Q.

[0136] like Figure 4 As shown, the insert nut 25 is embedded in a recess formed on the upper surface of the insulating member 24. For example, a fastening bolt is fixed to the insert nut 25 via a busbar that communicates with an external control device.

[0137] like Figure 1 As shown, the first side plate 26P is positioned at one end of the plurality of stacked batteries 10 along the stacking direction X, in the width direction Y. The first side plate 26P holds the plurality of batteries 10 along the stacking direction X. The two ends of the first side plate 26P extending along the stacking direction X are bent towards the width direction Y. Figure 4 As shown, the fastening bolt 27 is inserted into a plurality of insertion holes 26Pa formed on the side surface of the first side plate 26P along the width direction Y. As... Figure 1 As shown, the first side plate 26P is fixed to the first end block 23P and the second end block 23Q by fastening bolts 27.

[0138] like Figure 1 As shown, the second side plate 26Q is positioned at the other end of the plurality of batteries 10 along the stacking direction X of the stacked batteries 10 in the width direction Y. The second side plate 26Q holds the plurality of batteries 10 along the stacking direction X. The two ends of the second side plate 26Q extending along the stacking direction X are bent towards the width direction Y. Figure 4 As shown, the fastening bolt 27 is inserted into a plurality of insertion holes 26Qa formed on the side of the second side plate 26Q along the width direction Y. Figure 1 As shown, the second side plate 26Q is fixed to the first end block 23P and the second end block 23Q by fastening bolts 27.

[0139] like Figure 3 As shown, fastening bolts 27 fasten the first side plate 26P to the first end block 23P, and the first side plate 26P to the second end block 23Q. Additionally, as... Figure 3 As shown, fastening bolt 27 fastens the second side plate 26Q to the first end block 23P, and the second side plate 26Q to the second end block 23Q.

[0140] (The configuration of the busbar unit 30 of battery pack 1)

[0141] Figure 1 , Figure 3 and Figure 6 The busbar unit 30 shown electrically connects multiple batteries 10. For example... Figure 6 As shown, the busbar unit 30 includes a first-end busbar 31, a plurality of busbars 32, a second-end busbar 33, and a busbar retainer 34. The configuration of the busbar unit 30 will be described below.

[0142] like Figure 3 As shown, the first-end busbar 31 is connected to the positive terminal 310 of the battery 10 closest to the first-end block 23P among the stacked 20 batteries 10. Figure 6 As shown, the first-end busbar 31 includes a plate-shaped first joint 31a, a plate-shaped second joint 31b, a curved connecting portion 31c, and an insertion hole 31d. The first joint 31a is joined to a busbar that communicates with an external control device. The second joint 31b is joined to the positive terminal 310 of the battery 10. The connecting portion 31c connects the first joint 31a and the second joint 31b. The insertion hole 31d is formed in the first joint 31a. A fastening bolt is inserted into the insertion hole 31d. The first joint 31a is joined to the busbar that communicates with the external control device by the fastening bolt. The first-end busbar 31 is formed of aluminum, for example. In the case where the first-end busbar 31 is formed of a composite material, for example, the first joint 31a is formed of copper and the second joint 31b is formed of aluminum. When the negative terminal 320 of the battery 10 is constructed by converting copper to aluminum, the first terminal busbar 31 may also be configured such that the first joint 31a and the second joint 31b are integrally formed of aluminum.

[0143] like Figure 3 As shown, busbar 32 electrically connects one adjacent battery 10 to another battery 10 along the stacking direction X. Figure 3 As shown, the busbar 32 is connected to the positive terminal 310 of one adjacent battery 10 along the stacking direction X and the negative terminal 320 of the other adjacent battery 10 along the stacking direction X. Figure 6As shown, the busbar 32 includes a plate-shaped first joint 32a, a plate-shaped second joint 32b, and a curved connecting portion 32c. The first joint 32a is joined to the negative terminal 320 of an adjacent battery 10. The second joint 32b is joined to the positive terminal 310 of an adjacent battery 10. The connecting portion 32c connects the first joint 32a and the second joint 32b. The busbar 32 is formed, for example, from a composite material of copper and aluminum, copper, or aluminum. When the busbar 32 is formed from a composite material, for example, the first joint 32a is formed of copper, and the second joint 32b is formed of aluminum. When the negative terminal 320 of the battery 10 is configured to be converted from copper to aluminum, the busbar 32 may also be configured such that the first joint 32a, the second joint 32b, and the connecting portion 32c are integrally formed of aluminum.

[0144] like Figure 3 As shown, the second-end busbar 33 is connected to the negative terminal 320 of the battery 10 closest to the second-end block 23Q among the stacked 20 batteries 10. Figure 6 As shown, the second-end busbar 33 includes a plate-shaped first joint 33a, a plate-shaped second joint 33b, a curved connecting portion 33c, and an insertion hole 33d. The first joint 33a is engaged with the negative terminal 320 of the battery 10. The second joint 33b is engaged with a busbar that communicates with an external control device. The connecting portion 33c connects the first joint 33a and the second joint 33b. The insertion hole 33d is formed in the second joint 33b. A fastening bolt is inserted into the insertion hole 33d. The second joint 33b is engaged with the busbar that communicates with the external control device by the fastening bolt. The second-end busbar 33 is, for example, made of copper.

[0145] like Figure 1 As shown, the busbar holder 34 integrally holds the first-end busbar 31, multiple busbars 32, and the second-end busbar 33. Furthermore, the busbar holder 34 covers and insulates the multiple stacked batteries 10. (As shown...) Figure 6As shown, the busbar holder 34 is formed in the shape of a plate. Multiple openings 34a are formed in the busbar holder 34. Each opening 34a exposes the first or second joint of the first-end busbar 31, multiple busbars 32, and the second-end busbar 33 towards the battery 10. Each opening 34a is larger than the first or second joint of the corresponding busbar. Multiple retaining portions 34b are formed in the busbar holder 34. Each retaining portion 34b retains the end of the first or second joint of the first-end busbar 31, multiple busbars 32, and the second-end busbar 33. Each retaining portion 34b is formed at the edge of the opening 34a. Each retaining portion 34b includes a straight groove extending along the surface of the busbar holder 34. The end of the first or second joint of the corresponding busbar is inserted into the groove of each retaining portion 34b. Multiple insertion portions 34c are formed in the busbar holder 34. The wire 52 of the temperature measuring unit 50 is inserted into the insertion portion 34c.

[0146] (The structure of the voltage detection unit 40 of battery pack 1)

[0147] Figure 1 , Figure 3 and Figure 6 The voltage detection unit 40 shown detects the voltage of the battery 10, for example, based on control from an external control device. Figure 6 As shown, the voltage detection unit 40 includes a voltage detection terminal 41 and a wire 42. The configuration of the voltage detection unit 40 will be described below.

[0148] like Figure 6 As shown, the voltage detection terminal 41 is conductive and is formed in a plate shape. The voltage detection terminal 41 is respectively connected to the first end busbar 31, a plurality of busbars 32 and the second end busbar 33 of the busbar unit 30.

[0149] like Figure 6 As shown, wire 42 is connected to voltage detection terminal 41. Wire 42 connects voltage detection terminal 41 to an external control device.

[0150] (Composition of temperature measurement unit 50 of battery pack 1)

[0151] Figure 1 , Figure 3 and Figure 6 The temperature measurement unit 50 shown measures the temperature of the battery 10, for example, based on control from an external control device. Figure 3 As shown, the temperature measuring unit 50 includes a temperature sensor 51 and a wire 52. The configuration of the temperature measuring unit 50 will be described below.

[0152] Temperature sensor 51 measures the temperature of battery 10. For example... Figure 3As shown, for example, the temperature sensor 51 is attached to the cover 420 of the battery 10 at the 7th and 14th positions from the 1st end block 23P toward the 2nd end block 23Q.

[0153] like Figure 3 As shown, wire 52 is installed on temperature sensor 51. Wire 52 connects temperature sensor 51 to external control equipment.

[0154] (The structure of the exhaust unit 60 of battery pack 1)

[0155] Figure 1 The exhaust unit 60 shown exhausts the gas discharged from battery 10 to the outside of battery pack 1. Figure 1 As shown, the exhaust unit 60 includes a gas passage 61 and a fastening bolt 62. The following describes the configuration of the exhaust unit 60.

[0156] like Figure 8 As shown, the gas passage 61 includes a gas moving part 61a, a gas discharging part 61b, and a fixing part 61c. The gas moving part 61a extends along the stacking direction X. The gas moving part 61a is formed in a cuboid shape and has a space extending along its long side. The gas moving part 61a faces the rupture valve 430 of the stacked 20 batteries 10 across this space. While covering the rupture valve 430 of the stacked 20 batteries 10, the gas moving part 61a moves the gas discharged from the rupture valve 430 toward the gas discharging part 61b. Figure 8 As shown, the gas discharge section 61b opens at one end along the long side of the gas moving section 61a. The gas discharge section 61b is cylindrical. The gas discharge section 61b discharges the gas accumulated in the gas moving section 61a to the outside. The gas discharge section 61b can also be configured to connect to a flexible hose for discharging the gas. Figure 8 As shown, fixing portions 61c are formed at both ends along the long side of the gas moving portion 61a. The pair of fixing portions 61c are formed in a plate shape. Holes for inserting fastening bolts 62 are formed in the pair of fixing portions 61c.

[0157] like Figure 4 As shown, the fastening bolt 62 fixes the gas passage 61 to the threaded hole 23Pb of the first end block 23P via the fixing part 61c. Similarly, the fastening bolt 62 fixes the gas passage 61 to the threaded hole 23Qb of the second end block 23Q via the fixing part 61c.

[0158] (Effects of the battery 10 and battery pack 1 in the first embodiment)

[0159] The effects of the battery 10 and battery pack 1 in the first embodiment will be explained below.

[0160] (1) The battery 10 includes: a charging / discharging element 100; an outer casing 400 housing the charging / discharging element 100; a negative terminal (electrode terminal) 320 penetrating the outer casing 400 and electrically connected to the charging / discharging element 100; and a sealing body 600 insulating and sealing the outer casing 400 and the negative terminal 320. Figure 20 and Figure 21 As shown, the negative terminal 320, serving as an electrode terminal, has a connecting terminal 321 and an external terminal 322. The connecting terminal 321 is electrically connected to the charging / discharging body 100. The external terminal 322 has an insertion hole 322a for inserting the connecting terminal 321 and contacting the outer edge of the connecting terminal 321. The external terminal 322 has a first component 322x and a second component 322y. The first component 322x is laser-bonded to the connecting terminal 321. The second component 322y is stacked on the first component 322x and solid-state bonded to the first component 322x. The first component 322x and the connecting terminal 321 of the external terminal 322 contain a first metal. The second component 322y of the external terminal 322 contains a second metal of a different material than the first metal. The connecting terminal 321 includes a head 321a that is inserted into an insertion hole 322a of the external terminal 322, and an insertion portion 320b that protrudes from the head 321a into the charging / discharging body 100 and passes through a negative-side insertion hole (through hole) 420b of the outer casing 400. The sealing body 600 includes a flange portion (sealing portion) 632 of a negative-side first washer 630 sandwiched between the head 321a of the connecting terminal 321 and the outer casing 400. A laser-jointed portion 323 is formed by laser-joining the inner edge of the insertion hole 322a of the external terminal 322 with the outer edge of the head 321a of the connecting terminal 321. The laser-jointed portion 323 is formed in an annular shape along the inner edge of the insertion hole 322a. The diameter φD of the annular laser-jointed portion 323 is greater than the maximum diameter φd of the portion of the flange portion 632 that contacts the head 321a.

[0161] According to this configuration, when the flange portion 632 of the first gasket 630 on the negative electrode side is elastically deformed by the negative terminal 320 and assembled to the cover 420, shear stress can be prevented from being generated in the laser junction 323 due to the elastic reaction force of the flange portion 632 of the first gasket 630 on the negative electrode side. Therefore, according to this embodiment, a battery 10 that can suppress damage to the laser junction 323 can be obtained.

[0162] (2) Around the insertion hole 322a, the second component 322y is located further away from the charging / discharging body 100 than the first component 322x. In this configuration, damage to the laser junction 323 formed on the cover 420 side of the head 321a can be suppressed.

[0163] (4) The external terminal 322 includes a recessed portion (recess) 322a4 that is recessed opposite to the connecting terminal 321. The connecting terminal 321 includes a protruding portion (protrusion) 321a5 that protrudes toward the external terminal 322. The recessed portion 322a4 and the protruding portion 321a5 are in contact in the stacking direction (height direction Z) of the first component 322x and the second component 322y.

[0164] According to this configuration, by making the fitting recess 322a4 and the fitting protrusion 321a5 contact in the central axis direction (height direction Z) of the insertion hole 322a, the positions of the connecting terminal 321 and the external terminal 322 in the height direction Z are restricted. That is, by making the fitting recess 322a4 and the fitting protrusion 321a5 fit together, positioning that is performed before the laser bonding process of the connecting terminal 321 and the external terminal 322 can be easily performed.

[0165] (5) The end face 321a1 of the connecting terminal 321, which is opposite to the side where the charging / discharging body 100 is disposed, is located closer to the charging / discharging body 100 than the end face (terminal face 322b) of the external terminal 322, which is opposite to the side where the charging / discharging body 100 is disposed. With this configuration, the busbar 32 can be lap-welded to the external terminal 322 while the busbar 32 is abutting against the terminal face 322b of the external terminal 322.

[0166] (6) The first metal is a metal with copper as its main component. The second metal is a metal with aluminum as its main component. Therefore, the busbar 32 with aluminum as its main component can be easily and appropriately laser-bonded to the second part 322y of the negative terminal 320.

[0167] (7) For example Figures 1 to 3 As shown, the battery pack 1 includes the aforementioned battery 10 and a busbar 32 that engages with the negative terminal (electrode terminal) 320. Therefore, according to this embodiment, a battery pack 1 that can suppress damage to the laser-engaged portion 323 can be provided.

[0168] (A) A rectangular plate-shaped first component 322x is solidly bonded to a portion of the surface of the rectangular plate-shaped second component 322y on the cover 420 side. The first component 322x is stacked on the second component 322y around the insertion hole 322a. The external terminal 322 is formed of an embedded or edge-type composite material (i.e., a partial composite material). According to this configuration, since the copper-based material used in the external terminal 322 is reduced, the cost of the battery 10 can be reduced.

[0169] (B) In the fitting recess 322a4, a surface (step surface 322a3) that contacts the fitting protrusion 321a5 in the stacking direction (height direction Z) is provided on the second component 322y. According to this configuration, the insertion hole 322a and the fitting recess 322a4 can be formed simultaneously by hole machining such as cold forging or stamping. That is, since the hole machining of the external terminal 322 can be easily performed, the manufacturability of the external terminal 322 is good.

[0170] (Battery pack 1 of the first embodiment, variant 1)

[0171] The battery pack 1 of the first embodiment, in variation 1, has Figure 22 The negative extreme is shown as 1120.

[0172] (The composition of the negative extreme 1120)

[0173] The following reference Figure 22 Explain the composition of the negative extreme part 1120. Figure 22 This is a side view showing an enlarged cross-section of the negative terminal 1120 and its surrounding components in a modified example 1 of the first embodiment.

[0174] In Variation 1 of the first embodiment, the same reference numerals are used for configurations identical to those in the first embodiment, and descriptions are omitted. In Variation 1 of the first embodiment, different reference numerals are used for configurations different from those in the first embodiment, and descriptions are provided.

[0175] In the first embodiment, such as Figure 20 and Figure 21 As shown, the end face 321a1 of the negative terminal 320 on the busbar 32 side is located closer to the cover 420 side than the terminal face 322b of the external terminal 322. Figure 20 and Figure 21 The position is located on the lower side of the negative terminal 320. Therefore, in the first embodiment, a recess 320d is provided on the end face of the negative terminal 320 on the busbar 32 side.

[0176] In contrast, in a variation of the first embodiment, such as Figure 22 As shown, no recess is provided on the end face of the negative terminal 1120 on the busbar 32 side. The end face 1121a1 of the connecting terminal 1121 on the busbar 32 side is flush with the terminal face 322b of the external terminal 322 along the cover 420.

[0177] (Effects of battery 10 and battery pack 1 in Modification 1 of the first embodiment)

[0178] The effects of the battery 10 and battery pack 1 in Modification 1 of the first embodiment will be explained below. According to Modification 1 of the first embodiment, the effects of (1), (2), (4), (6), (7), (A), and (B) described in the first embodiment can be obtained.

[0179] (Battery pack 1 of variant 2 of the first embodiment)

[0180] The battery pack 1 of the modified example 2 of the first embodiment has Figure 23 The negative extreme is shown as 1220.

[0181] (The composition of the negative extreme 1220)

[0182] The following reference Figure 23 Explain the composition of the negative extreme 1220. Figure 23 This is a side view showing an enlarged cross-section of the negative terminal 1220 and its surrounding components in a modified example 2 of the first embodiment.

[0183] In Variation 2 of the first embodiment, the same reference numerals are used for configurations identical to those in the first embodiment, and descriptions are omitted. In Variation 2 of the first embodiment, different reference numerals are used for configurations different from those in the first embodiment, and descriptions are provided.

[0184] In the first embodiment, an example is described where the external terminal 322 is formed of an embedded or edge-type composite material. In the first embodiment, as... Figure 20 and Figure 21 As shown, the first component 322x is stacked on top of the second component 322y only around the insertion hole 322a.

[0185] In contrast, in a variation 2 of the first embodiment, such as Figure 23 As shown, the external terminal 1222 is formed of a so-called cover-type composite material. The first component 1222x, which is in the shape of a rectangular plate, is solid-state bonded to the entire surface of the cover 420 side of the second component 1222y, which is in the shape of a rectangular plate.

[0186] (Effects of battery 10 and battery pack 1 in variation 2 of the first embodiment)

[0187] The effects of the battery 10 and battery pack 1 in Modification 2 of the first embodiment will be explained below. According to Modification 2 of the first embodiment, the effects of (1), (2), (4) to (7), (B) described in the first embodiment can be obtained.

[0188] Furthermore, in a modified example 2 of the first embodiment, since there is no step between the rectangular plate-shaped first component 1222x and the rectangular plate-shaped second component 1222y, manufacturing is relatively easy.

[0189] (Battery pack 1 of the second embodiment)

[0190] The battery pack 1 in the second embodiment has Figure 24 The negative extreme is shown as 1320.

[0191] (The composition of the negative extreme 1320)

[0192] The following reference Figure 24 Explain the composition of the negative extreme 1320. Figure 24 This is a side view showing an enlarged cross-section of the negative terminal 1320 and its surrounding components in the second embodiment.

[0193] In the second embodiment, configurations identical to those in the first embodiment are given the same reference numerals as in the first embodiment, and descriptions are omitted. In the second embodiment, configurations different from those in the first embodiment are given different reference numerals and described differently.

[0194] In the first embodiment, such as Figure 20 and Figure 21 As shown, a fitting recess 322a4 and a fitting protrusion 321a5 are provided on the inner peripheral surface of the insertion hole 322a of the external terminal 322 and the outer peripheral surface of the head 321a of the connecting terminal 321, respectively, as fitting parts that fit together.

[0195] In contrast, in the second embodiment, such as Figure 24 As shown, no fitting portion is provided on the inner peripheral surface of the insertion hole 1322a of the external terminal 1322 and the outer peripheral surface of the head 1321a of the connecting terminal 1321. That is, no interlocking protrusions or recesses are provided on the outer peripheral surface of the head 1321a of the connecting terminal 1321 and the inner peripheral surface of the insertion hole 1322a of the external terminal 1322, from one end of the insertion hole 1322a to the other end.

[0196] (Effects of the battery 10 and battery pack 1 in the second embodiment)

[0197] The effects of the battery 10 and battery pack 1 in the second embodiment will be explained below. According to this second embodiment, the effects of (1), (2), (5) to (7), (A) described in the first embodiment can be obtained.

[0198] Furthermore, in the second embodiment, the connecting terminal 1321 can be inserted into the insertion hole 1322a of the external terminal 1322 from either one end or the other end. This increases the degree of freedom in laser bonding the connecting terminal 1321 to the external terminal 1322.

[0199] Furthermore, unaffected by component tolerances of the connecting terminal 1321 and the external terminal 1322, the relative positions of the connecting terminal 1321 and the external terminal 1322 in the height direction Z can be adjusted, and laser bonding can be performed at the desired position. For example, even if there is a dimensional difference between the connecting terminal 1321 and the external terminal 1322, the connecting terminal 1321 and the external terminal 1322 can be positioned in the height direction Z so that the lower end face of the head 1321a of the connecting terminal 1321 is flush with the lower end face of the external terminal 1322. Thus, even with component tolerances, a good laser-bonded portion 323 can be obtained.

[0200] Furthermore, even if the thickness of the head 1321a of the connecting terminal 1321 is greater than the design size, the connecting terminal 1321 and the external terminal 1322 can be positioned in the height direction Z, so that the end face 1321a1 of the connecting terminal 1321 is located closer to the cover 420 side than the terminal face 1322b of the external terminal 1322. This reliably prevents interference between the connecting terminal 1321 and the busbar 32.

[0201] (Battery pack 1 of the second embodiment)

[0202] In the second embodiment, such as Figure 24 As shown, the end face 1321a1 of the negative terminal 1320 on the busbar 32 side is located lower than the terminal face 1322b of the external terminal 1322. In contrast, in the modified example 1 of the second embodiment, although not shown, the end face 1321a1 of the connecting terminal 1321 on the busbar 32 side and the terminal face 1322b of the external terminal 1322 are flush with the cover 420.

[0203] (Effects of battery 10 and battery pack 1 in Modification 1 of the second embodiment)

[0204] The effects of the battery 10 and battery pack 1 in Modification 1 of the second embodiment will be explained below. According to this Modification 1 of the second embodiment, the effects of (1), (2), (6), (7), and (A) described in the first embodiment can be obtained.

[0205] Furthermore, in the second embodiment, variation 1, similar to the second embodiment, the relative positions of the connecting terminal 1321 and the external terminal 1322 in the height direction Z can be adjusted without being affected by the component tolerances of the connecting terminal 1321 and the external terminal 1322, and laser bonding can be performed at the desired position.

[0206] (Battery pack 1 of variant 2 of the second embodiment)

[0207] In the second embodiment, an example is described where the external terminal 1322 is formed of an embedded or edge-type composite material. However, the external terminal 1322 can also be formed of a so-called covering composite material. That is, in a variation 2 of the second embodiment, although not shown, the first and second rectangular plate-shaped components are solidly bonded to each other across their entire surfaces.

[0208] (Effects of battery 10 and battery pack 1 in Modification 2 of the second embodiment)

[0209] The effects of the battery 10 and battery pack 1 in the modified example 2 of the second embodiment will be explained below. According to the modified example 2 of this second embodiment, the effects (1), (2), (5) to (7) described in the first embodiment can be obtained.

[0210] Furthermore, in a variation 2 of the second embodiment, similar to the second embodiment, the relative positions of the connecting terminal 1321 and the external terminal 1322 in the height direction Z can be adjusted without being affected by the component tolerances of the connecting terminal 1321 and the external terminal 1322, and laser bonding can be performed at the desired position. Furthermore, since the cover-type composite material is easier to procure than the embedded or edge-type composite material, the material procurement cycle of the battery 10 can be shortened.

[0211] (Battery pack 1 of the third embodiment)

[0212] The battery pack 1 in the third embodiment has Figure 25 The negative extreme is shown as 1420.

[0213] (The composition of the negative extreme 1420)

[0214] The following reference Figure 25 Explain the composition of the negative extreme 1420. Figure 25 This is a side view showing an enlarged cross-section of the negative terminal 1420 and its surrounding components in the third embodiment.

[0215] In the third embodiment, configurations identical to those in the first embodiment are given the same reference numerals as in the first embodiment, and descriptions are omitted. In the third embodiment, configurations different from those in the first embodiment are given different reference numerals and described differently.

[0216] In the first embodiment, such as Figure 20 and Figure 21 As shown, around the insertion hole 322a, the second component 322y is located further away from the charging / discharging body 100 than the first component 322x. That is, the first component 322x is solid-state bonded to the surface of the second component 322y on the cover 420 side. The laser bonding portion 323 is formed on the cover 420 side of the head 321a.

[0217] In contrast, in the third embodiment, such as Figure 25 As shown, around the insertion hole 1422a, the first component 1422x is located further away from the charging / discharging body 100 than the second component 1422y. That is, the first component 1422x is solidly bonded to the surface of the second component 1422y on the busbar 32 side.

[0218] Furthermore, in the first embodiment, such as Figure 20 and Figure 21 As shown, a fitting recess 322a4 is provided on the surface of the external terminal 322 on the busbar 32 side, and a fitting protrusion 321a5 is provided at the end of the connecting terminal 321 on the busbar 32 side. In contrast, in the third embodiment, as... Figure 25 As shown, a fitting recess 1422a4 is provided on the surface of the outer terminal 1422 on the cover 420 side, and a fitting protrusion 1421a5 is provided on the end of the head 1421a of the connecting terminal 1421 on the cover 420 side.

[0219] A fitting recess 1422a4 is provided on the inner peripheral surface of the insertion hole 1422a of the external terminal 1422, which is recessed radially outward toward the insertion hole 1422a. A fitting protrusion 1421a5 is provided on the outer peripheral surface of the head 1421a of the connecting terminal 1421, which protrudes radially outward toward the insertion hole 1422a. The fitting recess 1422a4 of the external terminal 1422 is a recess that is recessed opposite to the outer peripheral surface of the head 1421a of the connecting terminal 1421. The fitting protrusion 1421a5 of the connecting terminal 1421 is a protrusion that protrudes toward the external terminal 1422. The fitting protrusion 1421a5 and the fitting recess 1422a4 are in contact at least in the stacking direction (height direction Z) of the first component 1422x and the second component 1422y.

[0220] Thus, in this embodiment, a fitting recess 1422a4 and a fitting protrusion 1421a5 are respectively provided on the inner peripheral surface of the insertion hole 1422a of the external terminal 1422 and the outer peripheral surface of the head 1421a of the connecting terminal 1421, serving as fitting portions that fit and contact each other. By contacting the stepped surface 1422a3 of the fitting recess 1422a4 with the stepped surface 1421a4 of the fitting protrusion 1421a5, the position of the external terminal 1422 and the connecting terminal 1421 in the height direction Z is defined. Therefore, the fitting recess 1422a4 and the fitting protrusion 1421a5 can be used for positioning the external terminal 1422 and the connecting terminal 1421 in the height direction Z.

[0221] (Effects of the battery 10 and battery pack 1 in the third embodiment)

[0222] The effects of the battery 10 and battery pack 1 in the third embodiment will be explained below. According to this third embodiment, the effects of (1), (4) to (7), (A), and (B) described in the first embodiment can be obtained.

[0223] Furthermore, in the third embodiment, the end face 1421a1 of the connection terminal 1421 is located closer to the charging / discharging body 100 than the terminal face 1422b of the external terminal 1422. With this configuration, interference between the laser bonding portion 1423 formed on the surface of the head 1421a on the side of the busbar 32 and the busbar 32 can be appropriately prevented.

[0224] (Battery pack 1 of the third embodiment)

[0225] In the third embodiment, such as Figure 25 As shown, the end face 1421a1 of the negative terminal 1420 on the busbar 32 side is located lower than the terminal face 1422b of the external terminal 1422. In contrast, in the modified example 1 of the third embodiment, although not shown, the end face 1421a1 of the connecting terminal 1421 on the busbar 32 side is flush with the terminal face 1422b of the external terminal 1422.

[0226] (Effects of battery 10 and battery pack 1 in Modification 1 of the third embodiment)

[0227] The effects of the battery 10 and battery pack 1 in Modification 1 of the third embodiment will be explained below. According to Modification 1 of this third embodiment, the effects of (1), (4), (6), (7), (A), and (B) described in the first embodiment can be obtained.

[0228] (Battery pack 1 of the fourth embodiment)

[0229] The battery pack 1 in the fourth embodiment has Figure 26 The negative extreme is shown as 1520.

[0230] (The composition of the negative extreme 1520)

[0231] The following reference Figure 26 Explain the composition of the negative extreme 1520. Figure 26 This is a side view showing an enlarged cross-section of the negative terminal 1520 and its surrounding components in the fourth embodiment.

[0232] In the fourth embodiment, configurations identical to those in the third embodiment are given the same reference numerals as those in the first embodiment, and descriptions are omitted. In the fourth embodiment, configurations different from those in the third embodiment are given different reference numerals and described accordingly.

[0233] In the third embodiment, such as Figure 25 As shown, on the inner peripheral surface of the insertion hole 1422a of the external terminal 1422 and the outer peripheral surface of the head 1421a of the connecting terminal 1421, there are fitting recesses 1422a4 and fitting protrusions 1421a5 that fit together as fitting parts.

[0234] In contrast, in the fourth embodiment, such as Figure 26 As shown, no fitting portion is provided on the inner peripheral surface of the insertion hole 1522a of the external terminal 1522 and the outer peripheral surface of the head 1521a of the connecting terminal 1521. No interlocking protrusions or recesses are provided on the outer peripheral surface of the head 1521a of the connecting terminal 1521 and the inner peripheral surface of the insertion hole 1522a of the external terminal 1522, from one end of the insertion hole 1522a to the other end.

[0235] (Effects of the battery 10 and battery pack 1 in the fourth embodiment)

[0236] The effects of the battery 10 and battery pack 1 in the fourth embodiment will be explained below. According to this fourth embodiment, the effects of (1), (5) to (7), and (A) described in the first embodiment can be obtained.

[0237] Furthermore, in the fourth embodiment, the connecting terminal 1521 can be inserted into the insertion hole 1522a of the external terminal 1522 from either one end or the other end. This increases the operational freedom when laser-bonding the connecting terminal 1521 and the external terminal 1522. Additionally, similar to the second embodiment, the relative positions of the connecting terminal 1521 and the external terminal 1522 in the height direction Z can be adjusted, and laser bonding can be performed at the desired position, regardless of component tolerances of the connecting terminal 1521 and the external terminal 1522.

[0238] (Battery pack 1 of the fourth embodiment, variant 1)

[0239] In the fourth embodiment, such as Figure 26 As shown, the end face 1521a1 of the negative terminal 1520 on the busbar 32 side is located lower than the terminal face 1522b of the external terminal 1522. In contrast, in the modified example 1 of the fourth embodiment, although not shown, the end face 1521a1 of the connecting terminal 1521 on the busbar 32 side is flush with the terminal face 1522b of the external terminal 1522.

[0240] (Effects of battery 10 and battery pack 1 in Modification 1 of the fourth embodiment)

[0241] The effects of the battery 10 and battery pack 1 in Modification 1 of the fourth embodiment will now be explained. According to Modification 1 of this fourth embodiment, the effects of (1), (6), (7), and (A) described in the first embodiment can be obtained.

[0242] Furthermore, in a variation 1 of the fourth embodiment, similar to the fourth embodiment, the connecting terminal 1521 can be inserted into the insertion hole 1522a of the external terminal 1522 from either one end or the other end. Therefore, the degree of freedom in laser bonding the connecting terminal 1521 and the external terminal 1522 is increased. Additionally, similar to the fourth embodiment, regardless of the component tolerances of the connecting terminal 1521 and the external terminal 1522, the relative positions of the connecting terminal 1521 and the external terminal 1522 in the height direction Z can be adjusted, and laser bonding can be performed at the desired position.

[0243] (Batteries or battery packs in other embodiments)

[0244] The battery or battery pack of the present invention is not limited to the configuration of the battery pack described in the embodiments, but can be appropriately configured based on the contents of the claims.

[0245] To facilitate understanding of the present invention, the embodiments have been described in detail or in a simplified manner. It is not necessary to have all the described configurations, or configurations not shown may also be present. In addition, some configurations of the embodiments may be deleted, or they may be replaced with configurations of other embodiments, or configurations of other embodiments may be combined.

[0246] In this embodiment, an example is described where the negative terminal is an electrode terminal with an external terminal in which a first component, primarily composed of copper, is solid-bonded to a second component, primarily composed of aluminum. However, the invention can also be applied to the positive terminal. In this case, for example, the positive terminal has an external terminal in which a first component, primarily composed of aluminum, is solid-bonded to a second component, primarily composed of copper. The negative terminal is formed only of a material primarily composed of aluminum. The busbar connecting the positive and negative terminals is formed only of a material primarily composed of copper. With this configuration, damage to the laser junction between the external terminal and the connecting terminal in the positive terminal can be suppressed.

[0247] The battery pack 1 contains no more than 20 batteries 10. For example, there may be 2 to 19 or more batteries 10. The batteries 10 are not limited to lithium-ion batteries. For example, nickel-metal hydride batteries or lead-acid batteries may be used in the batteries 10. The batteries 10 are not limited to rechargeable batteries. For example, primary batteries may be used in the batteries 10.

[0248] The charging / discharging element of the battery of the present invention is not limited to a wound charging / discharging element formed by bundling and winding positive electrodes, separators, and negative electrodes that are respectively formed into strips. The charging / discharging element of the battery of the present invention can be a stacked type formed by alternately stacking multiple positive electrodes, separators, and negative electrodes that are respectively formed into rectangles. The charging / discharging element of the battery of the present invention can be a stacked type in which multiple positive electrodes and multiple negative electrodes, formed into relatively short strips, are alternately arranged opposite each other with the separator in between. In this configuration, the positive and negative electrodes are opposite each other with the separator in between by folding and stacking the separator. The battery of the present invention is not limited to a configuration with only one charging / discharging element. The battery of the present invention can be applied to a configuration with two or more charging / discharging elements. The battery of the present invention is not limited to a configuration where the charging / discharging element is sealed by a container and a cap. The battery of the present invention can be applied to a configuration where the charging / discharging element is sealed by a laminated film.

[0249] The embodiments of the present invention may also be configured as follows.

[0250] like Figures 19 to 24 As shown, the battery 10 has a charging / discharging body 100, an outer casing 400 housing the charging / discharging body 100, an electrode terminal (negative terminal) penetrating the outer casing 400 and electrically connected to the charging / discharging body 100, and a sealing body 600 that seals while insulating the outer casing 400 from the electrode terminal. The electrode terminal (negative terminal) has a connecting terminal and an external terminal. The connecting terminal includes a first metal and is electrically connected to the charging / discharging body 100. The external terminal has a first component including the first metal and a second component including a second metal of a different material from the first metal. The first component includes an inner insertion hole for the connecting terminal to be inserted. The first component is laser-jointed to the connecting terminal along the edge of the inner insertion hole. The second component is located further away from the charging / discharging body 100 than the first component and includes an outer insertion hole for the connecting terminal to be inserted. The second component is solid-fitted to the first component. By laser-joining the inner edge of the inner insertion hole of the first component to the outer edge of the connecting terminal, an annular laser-jointed portion 323 is formed along the edge of the inner insertion hole. The diameter φD of the annular laser-joint portion 323 is larger than the maximum diameter φd of the portion of the sealing body 600 that contacts the connecting terminal. This configuration can suppress damage to the laser-joint portion 323 caused by the compressive reaction force of the sealing body 600.

[0251] like Figure 25 and Figure 26As shown, the battery 10 has a charge / discharge body 100, an outer casing 400 for housing the charge / discharge body 100, an electrode terminal (negative terminal) penetrating the outer casing 400 and electrically connected to the charge / discharge body 100, and a sealing body 600 that seals while insulating the outer casing 400 from the electrode terminal. The electrode terminal (negative terminal) has a connecting terminal and an external terminal. The connecting terminal includes a first metal and is electrically connected to the charge / discharge body 100. The external terminal has a first component including the first metal and a second component including a second metal of a different material from the first metal. The first component includes an outer insertion hole for inserting the connecting terminal. The first component is laser-joined to the connecting terminal along the edge of the outer insertion hole. The second component is located closer to the charge / discharge body 100 than the first component and includes an inner insertion hole for inserting the connecting terminal. The second component is solid-fitted to the first component. By laser-joining the inner edge of the outer insertion hole of the first component to the outer edge of the connecting terminal, an annular laser-joined portion 1423 is formed along the edge of the outer insertion hole. The diameter φD of the annular laser-jointed portion 1423 is larger than the maximum diameter φd of the portion of the sealing body 600 that contacts the connecting terminal. This configuration can suppress damage to the laser-jointed portion 1423 caused by the compressive reaction force of the sealing body 600.

[0252] like Figures 20 to 23 as well as Figure 25 As shown, the connecting terminal includes a protrusion (fitting protrusion) that intersects the stacking direction of the first and second components and protrudes toward the second component. The second component of the outer terminal includes another protrusion that contacts the first component and protrudes toward the connecting terminal that intersects the stacking direction. One protrusion (fitting protrusion) contacts the other protrusion in the stacking direction. When the connecting terminal is laser-bonded to the first component, by pressing the outer terminal toward the connecting terminal, the stepped portion acts as a stop, suppressing the positional deviation of the outer terminal relative to the connecting terminal in the height direction Z. That is, the connecting terminal can be relatively positioned relative to the first and second components.

[0253] Explanation of reference numerals in the attached figures

[0254] 1 Battery pack, 10 Battery, 10a Top surface, 10b Side surface, 10c Main surface, 20 Retaining unit, 21P First end spacer, 21Q Second end spacer, 22 Battery spacer, 23P First end block, 23Pa Threaded hole, 23Pb Threaded hole, 23Pc Insertion hole, 23Q Second end block, 23Qb Threaded hole, 23Qc Insertion hole, 24 Insulating component, 25 Insert nut, 26P First side plate, 26Pa Insertion hole, 26Q Second side plate, 26Qa Insertion hole, 27 Fastening bolt, 30 Busbar unit, 31 First end busbar, 31a First joint, 31b Second joint, 31c Connecting part, 31d Insertion hole, 32 Busbar, 32a First joint, 32b Second joint, 32c 33 Connecting part, 33 Second end busbar, 33a First joint, 33b Second joint, 33c Connecting part, 33d Insertion hole, 34 Busbar holder, 34a Opening, 34b Holder, 34c Insertion part, 40 Voltage detection unit, 41 Voltage detection terminal, 42 Wire, 50 Temperature measurement unit, 51 Temperature sensor, 52 Wire, 60 Exhaust unit, 61 Gas channel, 61a Gas moving part, 61b Gas exhaust part, 61c Fixing part, 62 Fastening bolt, 100 Charging / discharging body, 100a One side, 110 Positive electrode, 111 Positive electrode current collector layer, 111a Current collector, 111b Positive electrode tab, 111c Side edge, 112 Positive electrode active material layer, 120 Negative electrode, 121 Negative electrode current collector layer, 121a Current collector, 121b Negative electrode tab, 121c Side edge, 122 Negative electrode active material layer, 130 Separator, 140 Electrolyte (electrolyte solution), 200 Current collector, 210 Positive electrode current collector plate, 210a Base, 210b Insertion hole, 220 Negative electrode current collector plate, 220a Base, 220b Insertion hole, 300 Electrode terminal, 310 Positive terminal, 310a Base, 310b Insertion portion, 310c Joint portion, 320 Negative terminal, 320a Base, 320b Insertion portion, 320c Joint portion, 320d Recess, 321 Connecting terminal, 321a Head, 321a1 End face, 321a2 Large diameter portion, 321a3 Small diameter portion, 321a4 Stepped surface, 321a5 321a6 Inner engagement portion, 321d Pressing protrusion, 322 External terminal, 322a Insertion hole, 322a1 Large diameter hole, 322a2 Small diameter hole, 322a3 Stepped surface, 322a4 Inner engagement recess, 322a5 Outer engagement portion, 322b Terminal surface, 322x First component, 322y Second component, 322z Engaging surface, 323 Laser engagement portion, 400 Outer body, 410 Container, 410a Opening.410b Receiving part, 420 Cover, 420a Positive side insertion hole (through hole), 420b Negative side insertion hole (through hole), 420c Injection insertion hole, 421 Recess, 422 Pressing protrusion, 430 Rupture valve, 440 Sealing plug, 440a Head, 440b Insertion part, 500 Insulator, 510 Insulating cover, 520 Positive side insulating plate, 520a Base, 520b Insertion hole, 520c Protrusion, 530 Negative side insulating plate, 530a Base, 530b Insertion hole, 530b1 Large diameter hole, 530b2 Small diameter hole, 530b3 Stepped surface, 530c Protrusion, 530d Protrusion, 600 Sealing body, 610 Positive side first washer, 610a 1st insertion part, 610b; 2nd insertion part, 610c; Insertion hole, 620; 2nd gasket on the positive electrode side, 620a; Base, 620b; Insertion hole, 620c; Protrusion, 630; 1st gasket on the negative electrode side, 630c; Insertion hole, 631; Cylindrical part, 632; Flange (sealing part), 632a; Small diameter part, 632b; Large diameter part, 640; 2nd gasket on the negative electrode side, 640a; Base, 640b; Insertion hole, 640b1; Large diameter hole, 640b2; Small diameter hole, 640c; Protrusion, 641; Recess, 641a; Bottom surface, 641b; Inner side surface, 641c; Outer side surface, 700; Charge / discharge body, 710; Positive electrode, 711; Positive electrode active material layer, 712; Heat-resistant insulating layer, 1120 Negative terminal, 1121 Connecting terminal, 1121a1 End face, 1220 Negative terminal, 1221 Connecting terminal, 1221a Head, 1222 External terminal, 1222a Insertion hole, 1222x First component, 1222y Second component, 1320 Negative terminal, 1321 Connecting terminal, 1321a Head, 1321a1 End face, 1322 External terminal, 1322a Insertion hole, 1322b Terminal face, 1420 Negative terminal, 1421 Connecting terminal, 1421a Head, 1421a1 End face, 1421a4 Stepped surface, 1421a5 Fitting protrusion, 1422 External terminal, 1422a Insertion hole, 1422a3 Stepped surface, 1422a4 Fitting recess, 1422b Terminal face, 1422x First component, 1422y Second component, 1423 Laser bonding portion, 1520 Negative terminal, 1521 Connecting terminal, 1521a Head, 1521a1 End face, 1521a3 Stepped surface, 1521a4 Fitting recess, 1522 External terminal, 1522a Insertion hole, 1522b Terminal face, A (long side direction of battery 10), B (short side direction of battery 10), X (stack direction of battery pack 1), Y (width direction of battery pack 1), Z (height direction of battery pack 1),φd (diameter of the small diameter portion 632a of the first washer 630 on the negative electrode side), φD (diameter of the annular laser junctions 323 and 1423).

Claims

1. A battery, characterized in that, include: Charge and discharge bodies; An outer casing for housing the charging and discharging element; Electrode terminals that penetrate the outer casing and are electrically connected to the charging / discharging body; as well as A sealing body that insulates and seals the outer casing from the electrode terminals. The electrode terminals include: A connection terminal, comprising a first metal and electrically connected to the charging / discharging body; and An external terminal having an insertion hole for inserting the connecting terminal and contacting the outer edge of the connecting terminal. The external terminal includes: a first component comprising the first metal and laser-bonded to the connection terminal; and a second component comprising a second metal of a different material from the first metal, laminated to the first component and solidly bonded to the first component. The connection terminal includes: The head is inserted into the insertion hole of the external terminal; and An insertion portion that protrudes from the head into the charging / discharging body and passes through the through hole of the outer casing. The sealing body includes a sealing portion sandwiched between the head of the connecting terminal and the outer body. The laser-bonded portion, formed by laser bonding of the inner edge of the insertion hole of the external terminal and the outer edge of the head of the connecting terminal, is formed in a ring shape along the inner edge of the insertion hole. The diameter of the annular laser junction is larger than the maximum diameter of the portion of the sealing part that contacts the head.

2. The battery according to claim 1, characterized in that: Around the insertion hole, the second component is located further away from the charging / discharging body than the first component.

3. The battery according to claim 1, characterized in that: Around the insertion hole, the first component is located further away from the charging / discharging body than the second component.

4. The battery according to claim 1, characterized in that: The external terminal includes a recess that is opposite to and recessed from the connection terminal. The connection terminal includes a protrusion that extends toward the external terminal. The recess and the protrusion are in contact in the stacking direction of the first component and the second component.

5. The battery according to claim 1, characterized in that: The end face of the connecting terminal opposite to the side where the charging / discharging body is disposed is located closer to the charging / discharging body than the end face of the external terminal opposite to the side where the charging / discharging body is disposed.

6. The battery according to claim 1, characterized in that: The first metal is a metal whose main component is copper. The second metal is a metal whose main component is aluminum.

7. A battery pack, characterized in that, have: The battery according to claim 1; and Busbars that engage with the electrode terminals.

Images