Inter-device conduction member

Abstract

Provided is an inter-device conduction member whereby it is possible to break the inter-device conduction member itself and to cut off the electrical connection between power storage devices that are conducted via the inter-device conduction member. An inter-device conduction member (1) is provided with a conduction part (10) and a fracture inducing part (40). The conduction section (10) has: a first connection section (15) that is connected to an electrode terminal (120) of one power storage device (100); a second connection part (25) connected to an electrode terminal (130) of the other power storage device (100); and a rupture-scheduled section (35) that is positioned between the first connection section (15) and the second connection section (25) and that is electrically connected to the first connection section (15) and the second connection section (25). The fracture inducing part (40) is deformed by a temperature rise at or above the operating temperature (Ta), and fractures a fracture-scheduled part (35) in the conducting part (10), thereby making the first connecting part (15) and the second connecting part (25) non-conducting.

Description

TECHNICAL FIELD

[0001] The present application relates to an inter-device conduction member that conducts between an electrode terminal of one power storage device (battery, capacitor, or the like) and an electrode terminal of another power storage device. BACKGROUND

[0002] A battery pack having a plurality of batteries is mounted on a hybrid vehicle or a plug-in hybrid vehicle, an electric vehicle. In such a battery pack, a safety valve or a current interrupt device (CID) or the like is provided on each battery in order to improve safety. In the above-described battery pack, electrode terminals of adjacent batteries are conducted to each other by, for example, a busbar made of a rectangular plate-shaped metal plate. Such a busbar and a battery pack are disclosed in, for example, Patent Literature 1.

[0003] PRIOR ART DOCUMENTS

[0004] Patent Literature 1: Japanese Patent Application Publication No. 2024-085447 SUMMARY

[0005] PROBLEMS TO BE SOLVED BY THE INVENTION

[0006] However, it is desired to further improve the safety of the battery pack. The above-described conventional busbar is simply a metal plate, so, for example, in a case where the temperature of the busbar rises to a high temperature due to a large current flowing through the busbar or the like, the current flowing through the busbar cannot be interrupted to disconnect the electrical connection between the batteries.

[0007] The present application has been made in view of the above-described circumstances, and provides an inter-device conduction member that conducts between power storage devices such as batteries, which breaks itself when the temperature of the inter-device conduction member rises to a high temperature, and thereby disconnects the electrical connection between the power storage devices conducted via the inter-device conduction member.

[0008] MEANS FOR SOLVING THE PROBLEMS

[0009] (1) One embodiment of the present application for solving the above problem is an inter-device conduction member that conducts between an electrode terminal of one power storage device and an electrode terminal of another power storage device, in which the inter-device conduction member includes a conduction portion and a breakage-inducing portion, the conduction portion includes a first connecting portion connected to the electrode terminal of the one power storage device, a second connecting portion connected to the electrode terminal of the another power storage device, and a breakage-destined portion between the first connecting portion and the second connecting portion and conducting with the first connecting portion and the second connecting portion, and the breakage-inducing portion is deformed by temperature rise to a temperature above an operating temperature to break the breakage-destined portion in the conduction portion, and the first connecting portion and the second connecting portion are made not to conduct.

[0010] In the above inter-device conduction member, when the temperature of the breakage-inducing portion rises to a temperature above the operating temperature, the breakage-inducing portion is deformed to break the breakage-destined portion in the conduction portion, and the first connecting portion and the second connecting portion of the conduction portion are made not to conduct. Thus, the electrical connection between the power storage devices conducted by the inter-device conduction member can be cut off by the inter-device conduction member itself.

[0011] (2) Further, the inter-device conduction member described in (1) can be configured such that the conduction portion includes a first member composed of a first metal, a first non-connecting portion other than the first connecting portion, a second member composed of a second metal different from the first metal, a second non-connecting portion other than the second connecting portion, and a joint portion that joins a part of the first non-connecting portion and a part of the second non-connecting portion to conduct with each other.

[0012] (3) Further, the inter-device conduction member described in (2) can be configured such that the inter-device conduction member further includes a resin sealing member that hermetically seals the joint portion of the conduction portion.

[0013] (4) Further, in the inter-device conductive member described in (3), the first non-connection portion of the first member can have a first roughened sealing surface provided with first nano-pillars each having a height of 50 nm or more, the first nano-pillars being formed in a columnar shape by connecting first particles from the first metal forming the first member in a series, the second non-connection portion of the second member can have a second roughened sealing surface provided with second nano-pillars each having a height of 50 nm or more, the second nano-pillars being formed in a columnar shape by connecting second particles from the second metal forming the second member in a series, and the junction portion can be hermetically sealed by filling a resin material forming the resin sealing member between the first nano-pillars of the first roughened sealing surface and hermetically engaging the first roughened sealing surface, and by filling the resin material between the second nano-pillars of the second roughened sealing surface and hermetically engaging the second roughened sealing surface, thereby forming the resin sealing member.

[0014] (5) Further, in the inter-device conductive member described in any one of (1) to (4), the rupture-inducing portion can have a bimetallic member composed of a bimetallic material, and the rupture-inducing portion can be configured to deform by snapping upon reaching a temperature rise of the operating temperature or more, and to cause the rupture-destined portion of the conductive portion to rupture.

[0015] (6) Alternatively, in the inter-device conductive member described in any one of (1) to (4), the rupture-inducing portion can have a shape memory alloy member composed of a shape memory alloy material, and the rupture-inducing portion can be configured to deform upon reaching a temperature rise of the operating temperature or more as a phase transition point, and to cause the rupture-destined portion of the conductive portion to rupture.

[0016] (7) Alternatively, in the inter-device conductive member described in any one of (1) to (4), the rupture-inducing portion can include a fixed member composed of a thermoplastic resin or a low-melting point metal, and an elastic member held in a force-accumulating state by the fixed member, and the rupture-inducing portion can have a temperature-sensing structure configured to release the holding of the elastic member by the fixed member upon reaching a temperature rise of the operating temperature or more as a softening temperature of the thermoplastic resin or a melting point of the low-melting point metal, and to cause the rupture-destined portion of the conductive portion to rupture. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a plan view of a battery module configured using the busbar described in Embodiments 1 to 4.

[0018] Figure 2This is a top view of the busbar involved in Implementation Method 1.

[0019] Figure 3 It is the busbar involved in Implementation Method 1. Figure 2 The sectional view in the middle.

[0020] Figure 4 It is one of the busbars involved in Implementation Method 1. Figure 3 Enlarged cross-sectional view of the rupture initiation part and the vicinity of the resin sealing component.

[0021] Figure 5 This is an explanatory diagram showing an enlarged view of the joint between the first roughened sealing surface of the first component (or the second roughened sealing surface of the second component) and the resin sealing component, relating to the busbar according to Embodiment 1.

[0022] Figure 6 This is an explanatory diagram showing the situation in Embodiment 1 where the rupture-inducing part deforms due to temperature rise, causing the rupture-predicting part of the conductive part to rupture.

[0023] Figure 7 The illustration shows the following scenario involving the manufacturing method of the busbar according to Embodiment 1: a pulsed laser scan is performed to form a plurality of first bowl-shaped recesses and a plurality of first nanopillars (or a plurality of second bowl-shaped recesses and a plurality of second nanopillars) in each of the first bowl-shaped recesses in the first sealing portion of the first component (or the second sealing portion of the second component).

[0024] Figure 8 This relates to the busbars involved in implementation method 2. Figure 4 The corresponding enlarged sectional view.

[0025] Figure 9 This relates to the busbars involved in implementation method 2. Figure 6 The corresponding explanatory diagram.

[0026] Figure 10 This relates to the busbars involved in implementation method 3. Figure 4 The corresponding enlarged sectional view.

[0027] Figure 11 This relates to the busbars involved in implementation method 3. Figure 6 The corresponding explanatory diagram.

[0028] Figure 12 This relates to the busbars involved in implementation method 4. Figure 4 The corresponding enlarged sectional view.

[0029] Figure 13 This relates to the busbars involved in implementation method 4. Figure 6 The corresponding explanatory diagram. Detailed Implementation

[0030] (Implementation Method 1)

[0031] Hereinafter, the first embodiment of the present invention will be described with reference to the accompanying drawings. The busbar (inter-device communication member) 1 of this embodiment 1 (refer to...) Figures 1-5 ) is a battery module 200 (refer to) installed in hybrid electric vehicles, plug-in hybrid electric vehicles, electric vehicles, etc. Figure 1 This refers to a component that enables adjacent square (cubic-pole) batteries (energy storage devices) 100 to conduct electricity between each other. Furthermore, the height direction AH, length direction BH, and width direction CH of the busbar 1 are defined as follows: Figures 1-5 The directions shown will be used for explanation.

[0032] Battery module 200 has multiple batteries 100 (see reference) Figure 1 The batteries 100 constituting the battery module 200 alternately change orientation to be stacked in a row along the battery thickness direction and housed within a module housing (not shown), which is constrained by the module housing in the battery stacking direction SH. The positive terminal (electrode terminal) 120 of one battery 100 and the negative terminal (electrode terminal) 130 of the other battery 100 are arranged in the battery stacking direction SH and are electrically connected (connected in series) via busbar 1. Busbar 1 and the positive terminal 120 and the negative terminal 130 are joined by welding.

[0033] Each battery 100 comprises a rectangular box-shaped casing 110, an electrode body (not shown) housed within the casing 110 and containing positive and negative electrode plates, an electrolyte (not shown), and a positive terminal 120 and a negative terminal 130 respectively supported on the casing 110. A safety valve 113 is provided on the upper wall 111 of the casing 110, which ruptures and opens when the internal pressure of the casing 110 exceeds the valve opening pressure. Additionally, an injection hole (not shown) is provided on the upper wall 111 of the casing 110, which is airtightly sealed by a circular plate-shaped sealing member 115.

[0034] Additionally, a positive terminal 120 and a negative terminal 130 are fixedly disposed on the upper wall portion 111 of the housing 110. Specifically, a pair of through holes (not shown) are provided on the upper wall portion 111 of the housing 110. A positive terminal 120 made of a first metal (aluminum in this embodiment 1) is inserted into one through hole, and a negative terminal 130 made of a second metal different from the first metal (copper in this embodiment 1) is inserted into the other through hole. The positive terminal 120 is fixed to the upper wall portion 111 of the housing 110 via an insert-formed resin insulating member 125, and the negative terminal 130 is fixed to the upper wall portion 111 of the housing 110 via an insert-formed resin insulating member 135. The positive terminal 120 has a rectangular plate-shaped positive electrode top plate portion 121 disposed on the outside of the housing 110, and a busbar 1 is welded to the positive electrode top plate portion 121. Furthermore, the positive terminal 120 is electrically connected to the positive current collector of the electrode body within the housing 110. The negative terminal 130 has a rectangular plate-shaped negative terminal top plate portion 131 disposed on the outside of the housing 110, and a busbar 1 is welded to this negative terminal top plate portion 131. Furthermore, the negative terminal 130 is electrically connected to the negative current collector of the electrode body within the housing 110.

[0035] Next, busbar 1 will be explained (refer to...). Figures 1-5 The busbar 1 comprises a conductive section 10 that enables conduction between the positive terminal 120 and the negative terminal 130 of adjacent batteries 100, a rupture inducing section 40 that causes rupture in the conductive section 10, and a resin sealing member 50. The conductive section 10 is formed by joining a first member 11 made of the same first metal as the positive terminal 120 (aluminum in this embodiment 1) and a second member 21 made of the same second metal as the negative terminal 130 (copper in this embodiment 1).

[0036] The first component 11 is formed by stamping an aluminum sheet and consists of a flat plate portion 14 and a first receiving portion 13. The flat plate portion 14 is a rectangular plate extending in the length direction BH and the width direction CH. The first receiving portion 13 protrudes from the flat plate portion 14 on the other side BH2 in the length direction BH towards the upper side AH1 in the height direction AH, and is a bottomed square tube shape with an opening at the lower side AH2 and a closed upper side AH1. A cuboid receiving space SA is formed between the first receiving portion 13 and the second receiving portion 23 of the second component 21 (described later), and a rupture inducing part 40 is housed in the receiving space SA. The rectangular annular portion of the first receiving portion 13 located at the lower side AH2 in the height direction AH becomes the first sealing portion 18, which is hermetically sealed with the resin sealing member 50. Details of the first sealing portion 18 will be described later.

[0037] The flat plate portion 14 has a first connecting portion 15, a first sealing portion 16, and a first joining portion 17. In addition, in this embodiment 1, the portion of the first member 11 other than the first connecting portion 15, namely the aforementioned first receiving portion 13, first sealing portion 16, and first joining portion 17, is the first non-connecting portion 12.

[0038] The first connecting portion 15 is located on one side BH1 of the length direction BH, and is a rectangular plate extending in both the length direction BH and the width direction CH. This first connecting portion 15 is welded to the positive electrode top plate portion 121 of the positive terminal 120 of the battery 100.

[0039] The first joint 17 is a rectangular ring-shaped portion located on the other side BH2 of the length direction BH. The first joint 17 is welded to the second joint 27 of the second member 21 (described later), forming a joint 37 composed of the first joint 17 and the second joint 27. Through this joint 37, the first non-connecting portion 12 of the first member 11 and the second non-connecting portion 22 of the second member 21 (described later) are connected. In addition, in this embodiment 1, the joint 37 is a rupture-predicted portion 35. This rupture-predicted portion 35 (joint 37) is located in the connecting portion 10 between the first connecting portion 15 of the first member 11 and the second connecting portion 25 of the second member 21, and the first connecting portion 15 and the second connecting portion 25 are connected via the rupture-predicted portion 35. Therefore, if the rupture-predicted portion 35 breaks as described later, the first connecting portion 15 and the second connecting portion 25 become non-connected.

[0040] The first sealing portion 16 is located between the first connecting portion 15 and the first joining portion 17, and is a rectangular plate-shaped portion whose dimension in the width direction CH is larger than its dimension in the length direction BH. The first sealing portion 16 of the plate portion 14 and the first sealing portion 18 of the aforementioned first receiving portion 13 are each covered by a resin sealing member 50, and are airtightly joined with the resin sealing member 50. The first sealing portion 16 of the plate portion 14 has a first roughened sealing surface 16m in an annular shape covering the entire circumference orthogonal to the length direction BH (see reference). Figure 4 as well as Figure 5 On the other hand, the first sealing portion 18 of the first receiving portion 13 has a first roughened sealing surface 18m in an annular shape covering the entire circumference of the first housing portion 13 that is orthogonal to the height direction AH (see reference). Figure 4 as well as Figure 5 ).

[0041] These first roughened sealing surfaces, 16m and 18m, are nanometer-level (nanoscale) roughened surfaces, such as... Figure 5As shown, first nanopillars 33 with a height ha of 50 nm or more and less than 1000 nm are arranged in a columnar configuration. These first nanopillars 33 are formed by linking first particles 33p from the metal forming the first component 11 into a series. In this embodiment 1, the height ha of each first nanopillar 33 is approximately 200 nm. The metal forming the first component 11 is aluminum, as described above, and the first nanopillars 33 are formed using first particles 33p composed of aluminum and aluminum oxide.

[0042] The second component 21 is made of copper sheet and is a rectangular plate extending in the length direction BH and the width direction CH. The second component 21 has a second receiving portion 23, a second connecting portion 25, a second sealing portion 26, and a second joining portion 27. In this embodiment 1, the portions of the second component 21 other than the second connecting portion 25, namely the second receiving portion 23, the second sealing portion 26, and the second joining portion 27, are the second non-connecting portions 22.

[0043] The second receiving section 23 is a rectangular plate extending in the length direction BH and the width direction CH. As mentioned above, a receiving space SA for receiving the rupture inducing section 40 is formed between the second receiving section 23 and the first receiving section 13 of the first member 11.

[0044] The second connecting portion 25 is located on the other side BH2 in the length direction BH, and is a rectangular plate extending in both the length direction BH and the width direction CH. This second connecting portion 25 is welded to the negative electrode top plate portion 131 of the negative terminal 130 of the battery 100.

[0045] The second joint 27 is a rectangular ring-shaped portion located on the other side BH2 of the length direction BH. As described above, it is welded to the first joint 17 of the first member 11 to form a joint 37 (which is also the breakage predetermined portion 35 in this embodiment 1).

[0046] The second sealing portion 26 is located between the second connecting portion 25 and the second joining portion 27, and is a rectangular plate-shaped portion whose dimension in the width direction CH is larger than its dimension in the length direction BH. This second sealing portion 26 is covered by a resin sealing member 50 and is airtightly joined with the resin sealing member 50. The second sealing portion 26 has an annular second roughened sealing surface 26m covering the entire circumference orthogonal to the length direction BH (see reference). Figure 4 as well as Figure 5 The second roughened sealing surface, 26m, is also a nanometer-level roughened surface, such as... Figure 5As shown, numerous second nanopillars 34, with a height ha of 50 nm or more and less than 1000 nm, are arranged vertically. These second nanopillars 34 are formed into columnar shapes by linking second particles 34p from the metal forming the second member 21 together. In this embodiment 1, the height ha of each second nanopillar 34 is approximately 200 nm. The metal forming the second member 21 is copper, as described above, and the second nanopillars 34 are formed using second particles 34p composed of copper and copper oxide.

[0047] Next, the fracture induction part 40 will be described. In this embodiment 1, the fracture induction part 40 is composed of a bimetallic member 41. This bimetallic member 41 is composed of a coating material in which two metal plates (a first metal plate 42 and a second metal plate 43) with different coefficients of thermal expansion are bonded together in the thickness direction. Specifically, the bimetallic member 41 has a first metal plate 42 with a small coefficient of thermal expansion on the outer side (upper side AH1) and a second metal plate 43 with a large coefficient of thermal expansion on the inner side (lower side AH2). In this embodiment 1, a metal plate made of Ni-Fe alloy is used as the first metal plate 42, and a metal plate made of Ni-Mn-Fe alloy is used as the second metal plate 43.

[0048] The bimetallic component 41 consists of a semi-cylindrical portion 45 that extends along the width direction CH with its axis and flips over with a click, and a pair of ears (ends) 46 located on one side BH1 and the other side BH2 of the semi-cylindrical portion 45 along the length direction BH and extending along the width direction CH (see reference). Figure 4 These ear-like parts 46 are sandwiched between the first member 11 and the second member 21 and fixed to the conductive part 10. Thus, the bimetallic member 41 (rupture-inducing part 40) is fixed to the conductive part 10. Alternatively, it can be as follows: Figure 6 As shown in the dashed lines, an insulating member 48 made of insulating ceramic (e.g., alumina) is sandwiched between the bimetallic member 41 and the second member 21 to insulate the bimetallic member 41 from the second member 21. Alternatively, an insulating member (not shown) may be sandwiched between the ear portion 46 of the bimetallic member 41 and the first member 11 to insulate the bimetallic member 41 from the first member 11.

[0049] When the bimetallic component 41's temperature rises above the operating temperature Ta (Ta = 130°C in this embodiment 1), it flips and deforms with a click (see reference). Figure 6Furthermore, the bimetallic member 41 causes the predetermined breakage portion 35 of the conductive portion 10 to break, thus making the first connecting portion 15 and the second connecting portion 25 of the conductive portion 10 non-conductive. Specifically, the semi-cylindrical portion 45, which protrudes outward (upper AH1) in a semi-cylindrical shape, is deformed by the aforementioned temperature rise into a semi-cylindrical protrusion that protrudes inward (lower AH2). The semi-cylindrical portion 45 then pushes the second member 21 downward (AH2). On the other hand, a pair of ears 46 of the bimetallic member 41 push the first member 11 upward (AH1). This causes a breakage at the predetermined breakage portion 35 (joint portion 37). This breakage creates a gap between the first joint portion 17 and the second joint portion 27, thus making the first non-connecting portion 12 and the second non-connecting portion 22 non-conductive, and also making the first connecting portion 15 and the second connecting portion 25 non-conductive.

[0050] Next, the resin sealing member 50 will be described. The resin sealing member 50 is generally rectangular in shape and hermetically covers a portion of the conductive portion 10, sealing the joint 37 of the conductive portion 10 hermetically. The resin sealing member 50 is composed of a resin material 51 comprising a thermoplastic resin, a thermoplastic elastomer, and a fibrous filler. In this embodiment 1, the thermoplastic resin is polyphenylene sulfide (PPS), the thermoplastic elastomer is a thermoplastic polyurethane elastomer, and the fibrous filler is glass fiber. The resin sealing member 50 is insert-formed as described later.

[0051] The resin sealing member 50 covers only the first sealing portion 16, the first joint portion 17, and the first sealing portion 18 in the first receiving portion 13 of the first member 11, and is airtightly connected to the first sealing portions 16 and 18. In addition, the resin sealing member 50 covers the entire second sealing portion 26, the second joint portion 27, and the second receiving portion 23 in the second non-connecting portion 22 of the second member 21, and is airtightly connected to the second sealing portion 26.

[0052] Specifically, for the resin sealing member 50, resin material 51 forming the resin sealing member 50 is filled between the first nanopillars 33 that stand on the first roughened sealing surfaces 16m and 18m of the first sealing portions 16 and 18, respectively, and is airtightly bonded to the first roughened sealing surfaces 16m and 18m. This effectively prevents air or moisture from intruding into the interior of the resin sealing member 50 from the boundary between the first member 11 and the resin sealing member 50 and coming into contact with the joint 37. Furthermore, for the resin sealing member 50, resin material 51 forming the resin sealing member 50 is filled between the aforementioned second nanopillars 34 that stand on the second roughened sealing surface 26m of the second sealing portion 26, respectively, and is airtightly bonded to the second roughened sealing surface 26m. This effectively prevents air or moisture from intruding into the interior of the resin sealing member 50 from the boundary between the second member 21 and the resin sealing member 50 and coming into contact with the joint 37.

[0053] In the busbar 1 of this embodiment 1, when the temperature of the rupture induction part 40 rises above the operating temperature Ta, the rupture induction part 40 deforms, causing the rupture pre-rupture part 35 in the conductive part 10 to rupture, thus making the first connection part 15 and the second connection part 25 of the conductive part 10 non-conductive. Therefore, the electrical connection between the batteries 100 connected via the busbar 1 can be cut off by the busbar 1 itself. Furthermore, in this embodiment 1, since the rupture induction part 40 has a bimetallic member 41, when the temperature of the bimetallic member 41 rises above the operating temperature Ta, the bimetallic member 41 flips and deforms with a click, causing the rupture pre-rupture part 35 of the conductive part 10 to rupture.

[0054] Furthermore, in this embodiment 1, the positive terminal 120 of one of two adjacent batteries 100, made of a first metal (aluminum in this embodiment 1), is connected to the negative terminal 130 of the other battery 100, made of a second metal (copper in this embodiment 1), by a busbar 1. In contrast, the conductive portion 10 of the busbar 1 is formed by joining a first member 11 made of the same first metal as the positive terminal 120 and a second member 21 made of the same second metal as the negative terminal 130. Therefore, it is easy to connect the first member 11 of the busbar 1 to the positive terminal 120 of one battery 100 by welding, and it is easy to connect the second member 21 of the busbar 1 to the negative terminal 130 of the other battery 100 by welding.

[0055] Furthermore, in this embodiment 1, since the first component 11 and the second component 21 are dissimilar metals, galvanic corrosion can occur between the first joint 17 and the second joint 27 at the joint 37 where they are joined. In contrast, in the busbar 1, the joint 37 is hermetically sealed by the resin sealing member 50. Therefore, air or moisture can be prevented from contacting the joint 37, and corrosion between the first joint 17 and the second joint 27 can be suppressed.

[0056] Furthermore, in this embodiment 1, a first roughened sealing surface 16m and 18m, with the aforementioned first nanopillars 33 arranged vertically, is formed at the first non-connecting portion 12 of the first member 11. A second roughened sealing surface 26m, with the aforementioned second nanopillars 34 arranged vertically, is formed at the second non-connecting portion 22 of the second member 21. Resin material 51 is filled between the vertically arranged first nanopillars 33 on the first roughened sealing surfaces 16m and 18m, and a resin sealing member 50 is airtightly bonded to the first roughened sealing surfaces 16m and 18m. Similarly, resin material 51 is filled between the vertically arranged second nanopillars 34 on the second roughened sealing surface 26m, and a resin sealing member 50 is airtightly bonded to the second roughened sealing surface 26m, thereby airtightly sealing the joint 37. With this configuration, the joint 37 can be sealed with particularly high airtightness, thus more effectively suppressing corrosion at the joint 37.

[0057] Next, the manufacturing method of the busbar 1 described above will be explained. First, a first component 11, a second component 21, and a bimetallic component 41 are prepared. Then, the bimetallic component 41 is housed between the first receiving portion 13 of the first component 11 and the second receiving portion 23 of the second component 21, and the first joint portion 17 of the first component 11 and the second joint portion 27 of the second component 21 are overlapped and welded around the entire circumference. Thus, a conductive portion 10 is formed, which houses a fracture inducing portion 40 inside.

[0058] Next, surface roughening treatment is performed on the aforementioned conductive portion 10, forming nanoscale first roughened sealing surfaces 16m and 18m in the first sealing portions 16 and 18 of the first component 11, and forming nanoscale second roughened sealing surface 26m in the second sealing portion 26 of the second component 21 (see reference). Figure 7 Specifically, pulsed laser LB is intermittently irradiated into the first sealing portions 16 and 18 of the first component 11 while their irradiation positions are staggered, forming a first roughened sealing surface 16m and 18m with multiple first bowl-shaped recesses 31 arranged in a partially overlapping manner. The first bowl-shaped recesses 31 are provided with first nanopillars 33. For the laser irradiation conditions, the wavelength is set to 1064nm, the peak output is set to 5kW, the pulse width is set to 150ns, the spacing pb is set to 75μm, and the spot diameter is set to 80μm.

[0059] In the first sealing portions 16 and 18, at the locations irradiated by the pulsed laser LB, the first metal (aluminum in this embodiment 1) near the surface melts and becomes vapor. Then, if the temperature of the vapor decreases, it becomes first particles 33p of aluminum and aluminum oxide, which accumulate in the first bowl-shaped recess 31. By intermittently irradiating the first sealing portions 16 and 18 with staggered irradiation positions, the first particles 33p accumulate and combine into a series to form columnar structures, creating a forest of first nanopillars 33.

[0060] Furthermore, the second sealing portion 26 of the second component 21 is also intermittently irradiated with pulsed laser LB while being staggered in irradiation position, forming a second roughened sealing surface 26m with multiple second bowl-shaped recesses 32 arranged in a partially overlapping manner. The second bowl-shaped recesses 32 are provided with second nanopillars 34 (see reference). Figure 7 Additionally, for the laser irradiation conditions, the wavelength was set to 1064nm, the peak output to 20kW, the pulse width to 50ns, the spacing pb to 60μm, and the spot diameter to 75μm.

[0061] In the second sealing portion 26, at the location irradiated by pulsed laser LB, the second metal (copper in this embodiment 1) near the surface melts and becomes vapor. Then, if the temperature of the vapor decreases, it becomes second particles 34p of copper and copper oxide, which accumulate in the second bowl-shaped recess 32. By intermittently irradiating the second sealing portion 26 with staggered irradiation positions, the second particles 34p accumulate and combine into a series to form columnar structures, creating a forest of second nanopillars 34.

[0062] Next, the insert molding resin sealing member 50 is used. Specifically, a molding die (not shown) having an upper die and a lower die is used. The roughened guide portion 10, etc., described above are arranged at a predetermined position on the lower die, and then the molding die is closed. Next, molten resin of resin material 51 is injected into the cavity, and the cavity is filled by the molten resin. At this time, the molten resin of resin material 51 is filled between the first nanopillars 33 standing on the first roughened sealing surfaces 16m and 18m of the first sealing portions 16 and 18 of the first member 11 and between the second nanopillars 34 standing on the second roughened sealing surface 26m of the second sealing portion 26 of the second member 21 (see reference). Figure 5 Then, a resin sealing member 50 is formed to airtightly connect with the first roughened sealing surfaces 16m and 18m of the first member 11 and the second roughened sealing surface 26m of the second member 21. This resin sealing member 50 airtightly seals the joint 37 of the conductive portion 10. Thus, the busbar 1 is completed.

[0063] (Implementation Method 2)

[0064] Next, the second embodiment will be described (see reference). Figure 8 as well as Figure 9 Furthermore, descriptions of the same parts as in Embodiment 1 have been omitted or simplified. In the busbar 1 of Embodiment 1, the joint 37 in the conductive section 10 is configured as a rupture-predicted section 35 that will rupture when the busbar 1 becomes hot. In contrast, in the busbar (inter-device conductive member) 300 of this Embodiment 2, the difference is that the slot provided in the first member 311 in the conductive section 310 is configured as a rupture-predicted section 335.

[0065] The busbar 300 of this embodiment 2 is composed of a conductive portion 310 having a first member 311 and a second member 21, a rupture induction portion 40 formed by a bimetallic member 41, and a resin sealing member 350 (see reference). Figure 8 The first component 311 of the conductive part 310 is formed of the same first metal (specifically aluminum) as the first component 11 of Embodiment 1, but its shape is different from that of the first component 11. On the other hand, the second component 21 is the same as that of Embodiment 1. The first component 311 of this Embodiment 2 is composed of a first connecting part 315 and a first non-connecting part 312. The first non-connecting part 312 has a protrusion 314, a first receiving part 313, a slot (pre-break part) 335 and a first joining part 317.

[0066] The first connecting portion 315, like the first connecting portion 15 in Embodiment 1, is connected to the positive terminal 120 of the battery 100. The first receiving portion 313, like the first receiving portion 13 in Embodiment 1, receives the rupture inducing portion 40 within the receiving space SA formed between the first receiving portion 313 and the second receiving portion 23 of the second member 21. Furthermore, the first receiving portion 313, like the first sealing portion 18 in Embodiment 1, has a first roughened sealing surface 318m including nanometer-level roughening (see reference). Figure 5 The first sealing portion 318 and the first roughened sealing surface 318m are airtightly joined with the resin sealing member 350. The protrusion 314 extends from the first connecting portion 315 to the first receiving portion 313 and is the part that connects the first connecting portion 315 and the first receiving portion 313.

[0067] The first joint 317, like the first joint 17 in Embodiment 1, is a rectangular ring-shaped portion, and is welded to the second joint 27 of the second member 21 to form a joint 337 composed of the first joint 317 and the second joint 27. However, in this Embodiment 2, the joint 337 is not a predetermined breakage portion and will not break when the busbar 300 becomes hot.

[0068] In this embodiment 2, the fracture-predicting portion 335 is a slot (the part with a V-shaped groove) provided between the first receiving portion 313 and the first connecting portion 317, which is thinner and easier to fracture than other parts of the first member 311. This fracture-predicting portion 335 is also located in the connecting portion 310 between the first connecting portion 315 of the first member 311 and the second connecting portion 25 of the second member 21, and is in communication with both the first connecting portion 315 and the second connecting portion 25.

[0069] The fracture initiation part 40 is also composed of a bimetallic member 41, similar to that in Embodiment 1. As described above, when the temperature of the bimetallic member 41 rises above the operating temperature Ta (specifically Ta = 130°C), it snaps and deforms (see reference). Figure 9 Furthermore, in this embodiment 2, the groove portion (pre-breakage portion) 335 in the conductive portion 310 has lower strength than the joint portion 337 and is prone to breakage. Therefore, a breakage occurs in the groove portion (pre-breakage portion) 335. As a result, the first connecting portion 315 and the second connecting portion 25 of the conductive portion 310 become non-conductive.

[0070] The resin sealing member 350 is made of the resin material 51 described in Embodiment 1 above. It is generally rectangular in shape and hermetically covers a portion of the conductive portion 310, hermetically sealing the joint portion 337. Specifically, the resin sealing member 350 covers the first joint portion 317, the pre-break portion 335 formed by the groove portion, and the first sealing portion 318 in the first member 311, and hermetically engages with the first sealing portion 318. Furthermore, the resin sealing member 350 covers the second sealing portion 26, the second joint portion 27, and the second receiving portion 23 in the second member 21, and hermetically engages with the second sealing portion 26.

[0071] In the busbar 300 of this embodiment 2, when the temperature of the rupture induction part 40 rises above the operating temperature Ta, the rupture induction part 40 deforms, causing the rupture pre-rupture part 335 in the conductive part 310 to rupture, thus making the first connection part 315 and the second connection part 25 of the conductive part 310 non-conductive. Therefore, the electrical connection between the batteries 100 connected via the busbar 300 can be cut off by the busbar 300 itself. Furthermore, the same parts as in embodiment 1 perform the same effects as in embodiment 1.

[0072] (Implementation Method 3)

[0073] Next, the third embodiment will be described (see reference). Figure 10 as well as Figure 11Furthermore, descriptions of the same parts as in Embodiment 1 or 2 have been omitted or simplified. In the busbars 1 and 300 of Embodiments 1 and 2, bimetallic members 41 are used to construct the fracture inducing part 40. In contrast, in the busbar (inter-device communication member) 400 of this Embodiment 3, the difference is that a shape memory alloy member 441 is used to construct the fracture inducing part 440.

[0074] In this embodiment 3, the busbar 400 is composed of a conductive part 10, a rupture inducing part 440, and a resin sealing member 50 (see reference). Figure 10 The conductive part 10 and the resin sealing member 50 are the same as in Embodiment 1. On the other hand, in this Embodiment 3, the fracture inducing part 440 has a shape memory alloy member 441 made of shape memory alloy. The original shape of this shape memory alloy member 441 (see...) Figure 11 It is composed of a semi-cylindrical portion 445 extending along the width direction CH with its axis as the axis, and a pair of ear portions (ends) 446 located on one side BH1 and the other side BH2 of the semi-cylindrical portion 445 in the length direction BH and extending along the width direction CH. In the busbar 400 (refer to Figure 10 The shape memory alloy component 441 is housed in the receiving space SA of the conductive part 10 in a state of being pressed and deformed in the height direction AH. A pair of ears 446 are respectively clamped between the first component 11 and the second component 21 and fixed to the conductive part 10.

[0075] When the shape memory alloy component 441's temperature rises above the operating temperature Ta (Ta = 130°C in this embodiment 3), it will deform to restore its original shape (see reference). Figure 11 Furthermore, the predetermined breakage portion 35 of the conductive portion 10 is broken, making the first connecting portion 15 and the second connecting portion 25 of the conductive portion 10 non-conductive. Specifically, the semi-cylindrical portion 445, which has deformed in the height direction AH, is deformed back to its original semi-cylindrical shape by the aforementioned temperature rise. Furthermore, the semi-cylindrical portion 445 pushes the first member 11 upwards at AH1. On the other hand, the pair of ears 446 of the shape memory alloy member 441 push the second member 21 downwards at AH2. As a result, the joint portion 37 (predicted breakage portion 35) breaks in the same manner as in Embodiment 1, and the first connecting portion 15 and the second connecting portion 25 become non-conductive.

[0076] In this embodiment 3, when the temperature of the fracture induction part 440 rises above the operating temperature Ta, the fracture induction part 440 deforms, causing the fracture pre-fracture portion 35 in the conductive portion 10 to rupture, thus making the first connection portion 15 and the second connection portion 25 of the conductive portion 10 non-conductive. Therefore, the busbar 400 itself can disconnect the electrical connection between the batteries 100 connected via the busbar 400. In particular, in this embodiment 3, since the fracture induction part 440 has a shape memory alloy member 441, when the temperature of the shape memory alloy member 441 rises above the operating temperature Ta, the shape memory alloy member 441 deforms to restore its original shape, causing the fracture pre-fracture portion 35 of the conductive portion 10 to rupture. Furthermore, the same parts as in embodiment 1 or 2 perform the same effects as in embodiment 1 or 2.

[0077] (Implementation Method 4)

[0078] Next, the fourth embodiment will be described (see reference). Figure 12 as well as Figure 13 Furthermore, descriptions of the same parts as in any of Embodiments 1 to 3 have been omitted or simplified. In the busbars 1 and 300 of Embodiments 1 and 2, a bimetallic member 41 is used to construct the rupture induction part 40, and in the busbar 400 of Embodiment 3, a shape memory alloy member 441 is used to construct the rupture induction part 440. In contrast, in the busbar (inter-device communication member) 500 of this Embodiment 4, the difference is that a temperature-sensing structure 541 having an elastic member 545 and a fixing member 543 for fixing it is used to construct the rupture induction part 540.

[0079] In this embodiment 4, the busbar 500 is composed of a conductive part 10, a rupture inducing part 540, and a resin sealing member 50 (see reference). Figure 12 In this embodiment, the conductive part 10 and the resin sealing member 50 are the same as in embodiment 1. On the other hand, in this embodiment 4, the rupture inducing part 540 has a temperature-sensing structure 541 composed of an elastic member 545 and a fixing member 543. The rupture inducing part 540 is housed within the housing space SA of the conductive part 10.

[0080] The elastic member 545 is a helical spring, which is normally positioned such that its axis extends in the height direction AH and is in a state of being charged (contracted) in the height direction AH, and is held in the charged state by the fixing member 543.

[0081] In this embodiment 4, the fixing member 543 is made of thermoplastic resin. Alternatively, the fixing member 543 may also be made of a low-melting-point metal. The fixing member 543 is cylindrical with an outer diameter larger than that of the elastic member 545, and completely covers the radially outer side of the elastic member 545. Furthermore, the fixing member 543 is joined at its lower end to the second receiving portion 23 of the second member 21 in the conductive portion 10. Thus, the temperature-sensing structure 541 (rupture inducing portion 540) composed of the fixing member 543 and the elastic member 545 is fixed to the conductive portion 10.

[0082] When the fixed member 543 softens at a temperature above the operating temperature Ta (Ta = 130°C in this embodiment 4), the retaining force of the elastic member 545 by the fixed member 543 will be released (see reference). Figure 13 Furthermore, the elastic member 545 causes the predetermined breakage portion 35 of the conductive portion 10 to break, thus making the first connecting portion 15 and the second connecting portion 25 of the conductive portion 10 non-conductive. Specifically, if the fixing member 543 softens, the elastic member 545, which is composed of a coil spring, extends in the height direction AH. Furthermore, the elastic member 545 pushes the first member 11 upwards AH1 and pushes the second member 21 downwards AH2. As a result, the joint portion 37 (predicted breakage portion 35) breaks in the same way as in Embodiment 1, and the first connecting portion 15 and the second connecting portion 25 become non-conductive.

[0083] Furthermore, the busbar 500 of this embodiment 4 is formed by the following method: A second member 21 is prepared, and an elastic member 545 is disposed at a predetermined position in the second receiving portion 23 of the second member 21, thereby storing the elastic member 545. In this state, insert molding is performed to form a fixing member 543 that fixes the elastic member 545 in the stored state. As a result, a rupture inducing portion 540 is formed on the second receiving portion 23 of the second member 21. Then, the first joining portion 17 of the separately prepared first member 11 is overlapped at the second joining portion 27 of the second member 21, and these portions are welded to form a conductive portion 10 that internally houses the rupture inducing portion 540. Then, the busbar 400 is manufactured in the same manner as in embodiment 1.

[0084] In this embodiment 4, when the temperature of the rupture induction part 540 rises above the operating temperature Ta, the rupture induction part 540 deforms, causing the rupture pre-rupture part 35 in the conductive part 10 to rupture, thus making the first connection part 15 and the second connection part 25 of the conductive part 10 non-conductive. Therefore, the busbar 500 itself can cut off the electrical connection between the batteries 100 connected through the busbar 500. In particular, in this embodiment 4, since the rupture induction part 540 has a temperature-sensing structure 541 composed of an elastic member 545 and a fixing member 543, when the temperature of the fixing member 543 rises above the operating temperature Ta, the holding of the elastic member 545 by the fixing member 543 is released, and the elastic member 545 deforms to return to its original shape, causing the rupture pre-rupture part 35 of the conductive part 10 to rupture. Furthermore, the same parts as in any of embodiments 1 to 3 perform the same effects as in any of embodiments 1 to 3.

[0085] The present invention has been described above with respect to embodiments 1 to 4. However, the present invention is not limited to embodiments 1 to 4. Of course, appropriate modifications can be made to apply it without departing from its concept.

[0086] For example, in embodiments 1 to 4, lithium-ion secondary batteries are shown as energy storage devices, but the invention is not limited to these. Examples of energy storage devices include secondary batteries such as sodium-ion secondary batteries or calcium-ion secondary batteries, or capacitors such as lithium-ion capacitors.

[0087] Furthermore, in embodiments 1 to 4, the first component 11, 311 and the second component 21 are welded to form the conductive portions 10 and 310, but the joining method of the first component and the second component is not limited to this. Examples of joining methods of the first component and the second component include fastening with bolts and nuts, FSW (friction stir welding), riveting, and fixing with rivets.

[0088] Furthermore, in embodiments 1, 3, and 4, the joint portion 37 in the conductive portion 10 is designated as the rupture-predicting portion 35, and in embodiment 2, the slot portion provided in the first member 311 of the conductive portion 310 is designated as the rupture-predicting portion 335, but these are not limited to these. For example, a slot portion or a thin-walled portion may be provided in the second member of the conductive portion and used as the rupture-predicting portion. Alternatively, a slot portion or a thin-walled portion may be provided in both the first member and the second member and used as the rupture-predicting portion (multiple rupture-predicting portions may be provided).

[0089] Furthermore, in embodiments 1 to 4, busbars 1, 300, 400, and 500 are shown as connecting adjacent batteries 100 in series, but the present invention can also be applied to busbars that connect batteries in parallel. In this case, for the busbars connecting the positive terminals 120 of the batteries 100 to each other, it is preferable to form the first and second components of aluminum, which are the same as the positive terminals 120; and for the busbars connecting the negative terminals 130 of the batteries 100 to each other, it is preferable to form the first and second components of copper, which are the same as the negative terminals 130.

[0090] In addition, in embodiments 1 to 4, the resin sealing members 50 and 350 are configured to cover only a portion of the lower side AH2 of the first receiving portion 13 and 313 of the first member 11 and 311, but are not limited to this, the resin sealing members 50 and 350 may also be configured to cover the entire first receiving portion 13 and 313.

[0091] Explanation of reference numerals in the attached figures

[0092] 1. 300, 400, 500 busbars (inter-unit conductive components)

[0093] 10, 310 Conductor Section

[0094] 11, 311, Component 1

[0095] 12, 312 First non-connecting part

[0096] 15, 315 First connecting part

[0097] 16, 18, 318 First sealing part

[0098] 16m, 18m, 318m First roughened sealing surface

[0099] 17, 317 First joint

[0100] 21. Component 2

[0101] 22 Second non-connecting part

[0102] 25 Second connecting part

[0103] 26 Second sealing part

[0104] 26m second roughened sealing surface

[0105] 27 Second joint

[0106] 33 First nanopillar

[0107] 33p, first particle

[0108] 34 2nd nanometer column

[0109] 34p second particle

[0110] 35. Pre-crack section (joint)

[0111] 335 fracture pre-cut section (groove section)

[0112] 37, 337 joint

[0113] 40, 440, 540 rupture induction sites

[0114] 41 Bimetallic Components

[0115] 441 shape memory alloy components

[0116] 541 temperature sensing structure

[0117] 543 Fixed Components

[0118] 545 elastic member

[0119] 50, 350 resin sealing components

[0120] 51 Resin Material

[0121] 100 battery (energy storage device)

[0122] 120 Positive Terminal (Electrode Terminal)

[0123] 130 negative terminal (electrode terminal)

[0124] Ta operating temperature

[0125] ha height

Claims

1. A device-to-device conductive member that enables electrical connection between the electrode terminals of one energy storage device and the electrode terminals of another energy storage device, characterized in that, The aforementioned inter-device conductive components include a conductive portion and a rupture-inducing portion. The aforementioned conductive part has: The first connecting part is connected to the electrode terminal of the aforementioned energy storage device; The second connection portion is connected to the electrode terminal of the other energy storage device mentioned above; and A rupture-prevention section is located between the first connecting section and the second connecting section, and is in communication with both the first connecting section and the second connecting section. The aforementioned rupture inducing part deforms due to a temperature rise above the operating temperature, causing the aforementioned rupture pre-rupture part in the aforementioned conductive part to rupture, thereby making the connection between the aforementioned first connecting part and the aforementioned second connecting part non-conductive.

2. The inter-device conductive component as described in claim 1, characterized in that, The aforementioned conductive part has: The first component is made of a first metal and includes the first connecting portion and a first non-connecting portion other than the first connecting portion. The second component, made of a second metal different from the first metal, includes the second connecting portion and a second non-connecting portion other than the second connecting portion; and The joint connects a portion of the first non-connecting portion to a portion of the second non-connecting portion, thereby enabling them to communicate with each other.

3. The inter-device conductive component as described in claim 2, characterized in that, The aforementioned inter-device communication component also includes a resin sealing component, which airtightly seals the aforementioned joint portion of the communication portion.

4. The inter-device conductive component as described in claim 3, characterized in that, The first non-connecting portion of the first component has a first roughened sealing surface, on which first nanopillars with a height of 50 nm or more are vertically arranged. These first nanopillars are formed into a columnar shape by bonding first particles from the first metal forming the first component into a series. The second non-connecting portion of the second component has a second roughened sealing surface, on which second nanopillars with a height of 50 nm or more are vertically arranged. These second nanopillars are formed into a columnar shape by linking second particles from the second metal forming the second component into a series. The resin sealing member is formed by filling the spaces between the first nanopillars of the first roughened sealing surface with resin material forming the resin sealing member and airtightly bonding them to the first roughened sealing surface, and filling the spaces between the second nanopillars of the second roughened sealing surface with resin material and airtightly bonding them to the second roughened sealing surface, thereby airtightly sealing the joint.

5. The inter-device conductive member according to any one of claims 1 to 4, characterized in that, The aforementioned rupture inducing part has a bimetallic component, which is made of bimetal. By rising to a temperature above the aforementioned operating temperature, it flips and deforms with a click, causing the aforementioned rupture pre-determined part of the aforementioned conductive part to rupture.

6. The inter-device conductive member according to any one of claims 1 to 4, characterized in that, The aforementioned fracture inducing part has a shape memory alloy component, which is made of shape memory alloy and deforms by reaching a temperature rise above the aforementioned operating temperature, which is the phase transition point, causing the aforementioned fracture pre-fracture part of the aforementioned conductive part to fracture.

7. The inter-device conductive member according to any one of claims 1 to 4, characterized in that, The aforementioned rupture-inducing component includes: The fixing member is made of thermoplastic resin or low-melting-point metal; and An elastic member, which is held in a stored state by the aforementioned fixing member. The aforementioned rupture induction part has a temperature-sensing structure, which is configured to release the holding of the aforementioned fixing member on the aforementioned elastic member by a temperature rise that is above the aforementioned softening temperature of the aforementioned thermoplastic resin or the melting point of the aforementioned low melting point metal, thereby causing the aforementioned rupture pre-rupture part of the aforementioned conductive part to rupture.

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