Battery pack

Abstract

A battery pack capable of improving cooling efficiency is obtained. The present invention is provided with: a plurality of battery cells each having a positive electrode terminal and a negative electrode terminal; a battery case in which a plurality of battery cells are housed; a cover part which is formed by an insulator and is arranged relative to the battery case; and a bus bar having a main body portion embedded in the lid portion, and a connection terminal provided at an end portion of the main body portion, exposed from an inner surface of the lid portion facing the plurality of battery cells, and electrically connected to the positive electrode terminals and the negative electrode terminals of the plurality of battery cells. An outer surface of the cover portion is brought into contact with the cooler.

Description

Technical Field

[0001] This disclosure relates to battery packs. Background Technology

[0002] Previously, battery packs including a battery pack housing and a heat sink were known, such as those disclosed in Japanese Patent Application Publication No. 2023-126533. The battery pack housing has a battery pack tray supporting the lower part of the battery module and a battery pack cover configured to cover the battery module and contact the upper end surface of the battery module. The heat sink is mounted on the upper part of the battery pack cover.

[0003] However, in this battery pack, because the heat sink contacts the battery pack cover which is separate from the busbar, the distance between the heat sink and the busbar and battery module increases, resulting in a decrease in the cooling efficiency for the busbar and battery module.

[0004] Therefore, this disclosure provides a battery pack that can improve cooling efficiency. Summary of the Invention

[0005] The battery pack of the first technical solution disclosed herein comprises: a plurality of battery cells or a plurality of battery modules having positive electrode terminals and negative electrode terminals; a battery housing housing the plurality of battery cells or the plurality of battery modules; a cover portion made of an insulator disposed relative to the battery housing; and a busbar having a main body portion and a connecting terminal, the main body portion being embedded in the cover portion, the connecting terminal being disposed at the end of the main body portion and protruding from the inner surface of the cover portion opposite to the plurality of battery cells or the plurality of battery modules, and electrically connected to the positive electrode terminals and negative electrode terminals of the plurality of battery cells or the plurality of battery modules, such that the outer surface of the cover portion contacts a cooler.

[0006] According to the first technical solution, a battery casing houses multiple battery cells or multiple battery modules having positive electrode terminals and negative electrode terminals, and a cover made of an insulator is provided relative to the battery casing.

[0007] Furthermore, the main body of the busbar is embedded in the cover, and the connecting terminals located at the ends of the main body of the busbar protrude from the inner surface of the cover, which faces the multiple battery cells or multiple battery modules, and are electrically connected to the positive and negative electrode terminals of the multiple battery cells or multiple battery modules. Additionally, the outer surface of the cover is in contact with the cooler.

[0008] In other words, according to the first technical solution, since the busbar is embedded in the cover of the battery casing, it can efficiently exchange heat with the cooler. Therefore, compared to a separate structure where the cover and busbar of the battery casing are separate, the cooling efficiency of the battery pack is improved.

[0009] Furthermore, in the battery pack of the second technical solution involved in the first technical solution, based on the battery pack of the first technical solution, the connecting terminals of the busbar are electrically connected to the positive electrode terminal and the negative electrode terminal respectively via the connecting tabs, and are formed to a size that does not extend from the connecting tabs.

[0010] According to the second technical solution, the connecting terminals of the busbar are electrically connected to the positive and negative electrode terminals of multiple battery cells or multiple battery modules via connecting tabs, and are sized to not protrude from the connecting tabs. Therefore, compared with the case where the connecting terminals of the busbar protrude from the connecting tabs, the insulation between the electrode terminals in the multiple battery cells or multiple battery modules is well ensured.

[0011] Furthermore, in the battery pack of the third technical solution involved in this first technical solution, based on the battery pack of the first or second technical solution, the main body of the busbar embedded in the cover is more than twice the thickness of the main body from the outer surface of the cover and the side of the cover.

[0012] According to the third technical solution, the main body of the busbar embedded in the cover is more than twice the thickness of the main body from the outer surface and side surface of the cover. Therefore, compared to the case where the main body of the busbar embedded in the cover is only separated from the outer surface and side surface of the cover by the same amount as the thickness of the main body, the insulation between the electrode terminals in multiple battery cells or multiple battery modules is well ensured.

[0013] Furthermore, the battery pack of the fourth technical solution involved in this first technical solution is based on the battery pack of any of the first to third technical solutions, and a heat conduction member that contacts the plurality of battery cells or the plurality of battery modules is provided on the inner surface of the cover and in the portion other than the portion exposing the connection terminal.

[0014] According to the fourth technical solution, a heat-conducting member that contacts multiple battery cells or multiple battery modules is provided on the inner surface of the cover, except for the portion exposing the connecting terminals. Therefore, compared to the case where no heat-conducting member is provided on the inner surface of the cover to contact multiple battery cells or multiple battery modules, the heat dissipation of the multiple battery cells or multiple battery modules is improved.

[0015] Furthermore, the battery pack of the fifth technical solution involved in this first technical solution is based on the battery pack of any of the first to fourth technical solutions. The cover is composed of a cover body and an outer part. The cover body has an inner surface facing the plurality of battery cells or the plurality of battery modules. The outer part is formed of a high-strength material with higher strength than the cover body and covers at least one of the surfaces of the cover body other than the inner surface.

[0016] According to the fifth technical solution, the cover comprises a cover body having an inner surface facing multiple battery cells or multiple battery modules, and an outer part formed of a high-strength material with higher strength than the cover body and covering at least one of the surfaces of the cover body other than the inner surface. Therefore, the rigidity of the cover is improved, and warping of the cover is suppressed or prevented.

[0017] Furthermore, the battery pack of the sixth technical solution involved in the first technical solution includes: a plurality of battery cells or a plurality of battery modules having positive electrode terminals and negative electrode terminals; a battery housing housing the plurality of battery cells or the plurality of battery modules; a cover portion made of an insulator and disposed relative to the battery housing; and a busbar having a main body portion and a connecting terminal, the main body portion being embedded in the cover portion, the connecting terminal being disposed at the end of the main body portion and embedded in the cover portion, the connecting terminal being exposed at least a portion through a hole formed in the cover portion, the positive electrode terminals and negative electrode terminals of the plurality of battery cells or the plurality of battery modules being inserted through the hole portion and electrically connected to the connecting terminal, so that the outer surface of the cover portion is in contact with the cooler.

[0018] According to the sixth technical solution, a battery casing houses multiple battery cells or multiple battery modules having positive and negative electrode terminals, and a cover made of an insulator is provided relative to the battery casing. Furthermore, the main body of a busbar is embedded in the cover, and at least one of the connecting terminals located at the end of the main body of the busbar is exposed and embedded in the cover through holes formed in the cover. The positive and negative electrode terminals of the multiple battery cells or multiple battery modules are inserted through these holes and electrically connected to the connecting terminals, so that the outer surface of the cover contacts the cooler.

[0019] In other words, according to the sixth technical solution, the busbar is embedded in the cover of the battery casing, thus enabling efficient heat exchange with the cooler. Therefore, compared to a separate structure where the cover and busbar of the battery casing are separate, the cooling efficiency of the battery pack is improved.

[0020] In addition, based on the battery pack of any of the first to sixth technical solutions, the entire outer surface of the cover is in contact with the cooler in the seventh technical solution of this disclosure.

[0021] According to the seventh technical solution, the entire outer surface of the cover contacts the cooler. Therefore, compared to the case where only a portion of the outer surface of the cover contacts the cooler, the cooling efficiency of the battery pack is improved.

[0022] As described above, the present disclosure enables improved cooling efficiency for the battery pack. Attached Figure Description

[0023] Exemplary embodiments of the present invention will be described in detail with reference to the following accompanying drawings, wherein:

[0024] Figure 1 This is a schematic front view showing the configuration of the battery pack according to the first embodiment;

[0025] Figure 2 This is a schematic front view showing the internal structure of the battery pack according to the first embodiment;

[0026] Figure 3 This is a schematic bottom view showing the inner surface of the cover of the battery pack according to the first embodiment;

[0027] Figure 4 yes Figure 3 A rough cross-sectional view along the XX line;

[0028] Figure 5 This is a schematic perspective view showing the battery cells of the battery pack according to the first embodiment;

[0029] Figure 6 This is a schematic bottom view showing the internal structure of the battery pack according to the first embodiment;

[0030] Figure 7 This is a schematic bottom view showing the inner surface of the cover of the battery pack according to the second embodiment;

[0031] Figure 8 This is a schematic front view showing the internal structure of the battery pack according to the third embodiment;

[0032] Figure 9 This is a schematic front view showing the internal structure of the battery pack according to the fourth embodiment;

[0033] Figure 10 This is a schematic front view showing the internal structure of the battery pack according to the fifth embodiment;

[0034] Figure 11 This is a schematic top view showing the internal structure of the battery pack according to the sixth embodiment;

[0035] Figure 12AThis is a schematic bottom view showing the internal structure of the battery pack according to the seventh embodiment;

[0036] Figure 12B yes Figure 12A A rough cross-sectional view along the YY line. Detailed Implementation

[0037] The embodiments disclosed herein will now be described in detail based on the accompanying drawings. Furthermore, for ease of explanation, in each figure, arrow UP will be appropriately shown as the upward direction of the vehicle, arrow FR as the forward direction of the vehicle, and arrow RH as the rightward direction of the vehicle. Additionally, in the following description, unless otherwise specified, the directions of up / down, forward / backward, and left / right will be used to represent the up / down, forward / backward, and left / right directions of the vehicle. Furthermore, the left / right direction has the same meaning as the vehicle width direction.

[0038] <First Implementation>

[0039] First, the first embodiment will be described. Figure 1 As shown, a generally flat floor 12 is provided in a vehicle 10, such as an electric vehicle, and a generally flat cooler 18 is disposed on the lower side of the floor 12. The battery pack 20 according to the first embodiment is disposed on the lower side of the cooler 18 mounted on the vehicle 10.

[0040] Specifically, a pair of left and right longitudinal beams 14, which are generally hat-shaped in the front view, are provided on the lower surface of the floor 12, which is located on the outer side of the cooler 18 in the vehicle width direction. That is, a flange portion 14A extending outward and inward in the vehicle width direction, respectively, is integrally formed at the upper end of each longitudinal beam 14. The flange portion 14A is joined and installed on the lower surface of the floor 12 by welding or the like.

[0041] At the center of the lower end 14B of each longitudinal beam 14 in the vehicle width direction, a plurality of through holes for bolt insertion are arranged in the front-rear direction (not shown). On the upper surface of the lower end 14B, a plurality of weld nuts 15 are provided coaxially with each through hole. Furthermore, a support platform 16 is provided in the vehicle 10 to support the battery pack 20 from below.

[0042] The support platform 16 has a flat plate portion 16A of predetermined thickness for mounting the battery pack 20 and a protruding portion 16B of predetermined thickness integrally formed at both ends of the outer side of the flat plate portion 16A in the vehicle width direction. In the front view, the protruding portion 16B extends upward in a generally inverted "L" shape, and a plurality of through holes for bolt insertion are arranged in the front-rear direction at the center of the protruding portion 16B in the vehicle width direction (not shown).

[0043] Furthermore, the lower end of the support member 16C is installed on the lower part of the left and right sides of the flat plate portion 16A facing outward in the vehicle width direction, and the upper end of the support member 16C is installed on the outer end of the lower surface of the protrusion portion 16B in the vehicle width direction. In other words, the outer end of the protrusion portion 16B in the vehicle width direction is supported by the flat plate portion 16A via the support member 16C.

[0044] The battery pack 20 has a battery housing 22, which will be described later. Flange portions 22A extending outward in the vehicle width direction are integrally formed on the left and right sidewalls 22S of the battery housing 22. (Only when...) Figure 1 (As shown in the figure). Each flange portion 22A is formed at a height position where its lower surface overlaps the upper surface of the protrusion portion 16B from above when the battery housing 22 (battery pack 20) ​​is placed on the flat plate portion 16A. Furthermore, each flange portion 22A has a plurality of through holes for bolt insertion arranged in the front-rear direction (not shown).

[0045] Therefore, by placing the battery pack 20 (battery housing 22) on the flat plate 16A and using the support platform 16 that supports each flange portion 22A by each protrusion 16B, the upper surface of each flange portion 22A contacts the lower surface of the lower end 14B of each longitudinal beam 14, and multiple bolts 17 are inserted from the lower side of each protrusion 16B into each through hole and screwed into each welding nut 15, thus forming the configuration of the longitudinal beams 14 installed on the left and right.

[0046] Thus, the upper surface (outer surface) of the cover 24 of the battery pack 20, described later, is configured to contact the cooler 18 from below with a predetermined pressure. Furthermore, the surface of the cover 24 facing the battery cell 30 housed in the battery housing 22 is the inner surface, and the surface facing the opposite side of the inner surface is the outer surface; the upper surface is not necessarily always the outer surface.

[0047] like Figure 2 As shown, the battery pack 20 includes: a box-shaped battery housing 22 with side walls (including left and right side walls 22S) of a predetermined height integrally erected (erected) on the edge of a rectangular flat bottom wall in the vehicle width direction and an opening on the top side; and a rectangular flat cover 24 that closes the opening on the top side of the battery housing 22. Furthermore, the term "closed" for the cover 24 here includes both completely closing the opening of the battery housing 22 and closing only a portion of the opening of the battery housing 22.

[0048] The battery casing 22 is made of an insulator (a resin material that is easy to mold in one piece: such as polyamide or other engineering plastics), and houses inside it a plurality of electrodes having positive electrode terminals 30A and negative electrode terminals 30B. Figure 2 The image simply shows 6 battery cells 30.

[0049] Multiple battery cells 30 are arranged with their thickness along the length (vehicle width) of the battery housing 22 and are constrained by a constraint clamp 32. The constraint clamp 32 consists of a flat constraint plate 32A and a pair of front and rear constraint straps 32B. The flat constraint plate 32A is disposed at both ends of the battery housing 22 along its length and overlaps with the battery cells 30 at those ends. The pair of front and rear constraint straps 32B extend along the length of the battery housing 22 and integrally connect the upper and lower parts of each constraint plate 32A.

[0050] The cover 24 is made of an insulator (preferably the same resin material as the battery casing 22 to ensure uniform thermal expansion), such as Figures 2-4 As shown, the main body 26A of the busbar 26 is embedded in a manner that does not expose to the outside and without gaps. The busbar 26 is made of metal, and from the viewpoint of improving cooling performance, it is preferably made of copper, which has good electrical conductivity.

[0051] Connecting terminals 26B are integrally provided at both ends of the main body 26A of the busbar 26, and the lower surface of the connecting terminals 26B protrudes from the inner surface of the cover 24, which faces the plurality of battery cells 30 in the vertical direction. Furthermore, in Figure 2 And the following Figures 8-11 In the diagram, each connecting terminal 26B is simplified as a flat plate.

[0052] In addition, such as Figure 3 As shown, in the bottom view (top view), the main body 26A of each busbar 26 is embedded at an angle (at a predetermined angle) relative to the front-to-back direction. Furthermore, as... Figure 6 As shown, the connection terminal 26B of each busbar 26 is electrically connected to the positive electrode terminal 30A of one adjacent battery cell 30 and the negative electrode terminal 30A of the other adjacent battery cell 30, respectively. Furthermore, in Figure 6 The illustration of thermostat 28, which will be described later, is omitted.

[0053] Furthermore, at the upstream and downstream ends of the current path formed by the multiple busbars 26, a main positive junction box 36 and a main negative junction box 38 are electrically connected via flexible power cables 37, respectively. The main positive junction box 36 and the main negative junction box 38 are also disposed inside the battery housing 22 (see reference). Figure 2 , Figure 6 ).

[0054] In addition, such as Figure 2As shown, a detector (battery ECU) 40 for detecting the voltage and temperature of the connection terminals 26B in each busbar 26 is provided on the outside of the battery pack 20. That is, in order to accurately measure the temperature of the busbar 26, the thermostat 28 is configured to be in contact with each connection terminal 26B (see reference). Figure 3 Each connection terminal 26B and the thermostat 28 are electrically connected to the detector 40 via the detection line 27. In addition, the detection line 27 and the thermostat 28 are also embedded in the cover 24, with only "a portion of the detection line 27 for connection with the detector 40" extending out from the side wall of the cover 24.

[0055] In addition, such as Figure 4 As shown, the main body 26A of the busbar 26 embedded in the cover 24 is embedded in such a way that the thickness (plate thickness D) of the main body 26A is more than twice the distance from the upper surface (outer surface) of the cover 24 and the side surface of the cover 24 away from the main body 26A. That is, the distance W1 from the upper surface of the cover 24 to the upper surface of the main body 26A and the distance W2 from the side surface of the cover 24 to the side surface of the main body 26A are set to more than twice the thickness (plate thickness D) of the main body 26A.

[0056] In addition, such as Figure 5 , Figure 6 As shown, the connection terminals 26B of the busbar 26 are electrically connected to the positive electrode terminal 30A and the negative electrode terminal 30B via the bonding tabs 34. The bonding tabs 34 are also made of metal, and from the viewpoint of improving cooling performance, they are preferably made of copper, which has good electrical conductivity.

[0057] Each engagement tab 34, in the top view, is formed as a rectangular plate with the longitudinal direction as its length, and its size is set to be larger than the size of each positive electrode terminal 30A and each negative electrode terminal 30B. In other words, each positive electrode terminal 30A and each negative electrode terminal 30B is formed to a size that does not protrude from the engagement tab 34.

[0058] Furthermore, from the viewpoint of ensuring the insulation between the positive electrode terminals 30A and the negative electrode terminals 30B of adjacent battery cells 30, and the insulation between the positive electrode terminals 30A and the negative electrode terminals 30B of the battery cell 30 itself, it is preferable that the connecting tabs 34 have a spacing of 5 mm or more between each other (in the absence of an insulating member between them).

[0059] The function of the battery pack 20 according to the first embodiment configured as described above will now be explained.

[0060] As described above, a plurality of battery cells 30 having a positive electrode terminal 30A and a negative electrode terminal 30B are housed in a box-shaped battery casing 22 made of an insulator (resin material), and the opening of the battery casing 22 is closed by a cover 24 made of an insulator (resin material).

[0061] In addition, the main body 26A of the busbar 26 is embedded in the cover 24, and the connection terminals 26B provided at both ends of the main body 26A of the busbar 26 are exposed from the inner surface of the cover 24 opposite to the plurality of battery cells 30, and are electrically connected to the positive electrode terminal 30A and negative electrode terminal 30B of the adjacent plurality of battery cells 30.

[0062] Furthermore, the upper surface (outer surface) of the cover 24 contacts the cooler 18 mounted on the vehicle 10 with a predetermined pressure. Therefore, compared to the separate configuration of the cover 24 and the busbar 26 of the battery housing 22, the thermal path from the cooler 18 to the battery cell 30 can be shortened, its thermal resistance is reduced, and as a result, each battery cell 30 can be cooled effectively. That is, the cooling efficiency of the battery pack 20 can be improved.

[0063] Furthermore, compared to a separate configuration of the cover 24 and busbar 26 of the battery housing 22, the surface area of ​​the busbar 26 in contact with the cover 24 of the battery housing 22 can be increased. Therefore, compared to the conventional configuration, the busbar 26 can more easily exchange heat with the cooler 18, effectively cooling both the busbar 26 and each battery cell 30. In other words, the cooling efficiency of the battery pack 20 can be improved.

[0064] In particular, since the entire upper surface of the cover 24 is in contact with the cooler 18 under a predetermined pressure, compared to the case where only a part of the upper surface of the cover 24 is in contact with the cooler 18, the cover 24 and each busbar 26 embedded in the cover 24 can be cooled directly and effectively, thus improving the cooling efficiency of the battery pack 20 more effectively.

[0065] Furthermore, since the battery casing 22 and the cover 24 are made of resin, the battery pack 20 can be made lighter. In addition, as described above, since the entire upper surface of the cover 24 is in contact with the cooler 18 under a predetermined pressure (the cooler 18 can be used as a reinforcing member), even if the cover 24 is made of resin, warping can be suppressed or prevented. Even if the thickness of the cover 24 is made thinner for further weight reduction, insufficient strength and insufficient sealing can be suppressed or prevented.

[0066] Furthermore, since the battery pack 20 is configured to contact the cooler 18 from the bottom, the ease of loading and unloading the battery pack 20 relative to the vehicle 10 is improved. In other words, the cooler 18 does not need to be loaded or unloaded when loading or unloading the battery pack 20, thus reducing the operation time and workload required for this process.

[0067] Furthermore, since the busbar 26, detection line 27, and thermostat 28 are integrated into the cover 24, the number of components can be reduced compared to a case where the busbar 26, detection line 27, and thermostat 28 are separate from the cover 24. That is, there is no need to install connectors such as those for connecting the detection line 27 inside the battery housing 22. Additionally, this eliminates the need for wiring space for the detection line 27, thus saving space inside the battery housing 22.

[0068] Furthermore, although the illustration is omitted, when multiple busbars are exposed from the inner surface of the cover 24, it is necessary to increase the spacing between the battery cells 30 to ensure their insulation. However, in the first embodiment, each of the multiple busbars 26 has its main body 26A (excluding the connecting terminal 26B) embedded in the cover 24, ensuring their insulation, so it is not necessary to increase the spacing between the battery cells 30 (the battery cells 30 can be arranged close to each other). As a result, the size of the battery pack 20 can be reduced at least in the left-right direction.

[0069] Furthermore, the connection terminals 26B of the busbar 26 are electrically connected to the positive electrode terminals 30A and negative electrode terminals 30B of the adjacent plurality of battery cells 30 via the bonding tabs 34, and are sized to not protrude from the bonding tabs 34. Therefore, compared to the case where the connection terminals 26B of the busbar 26 protrude from the bonding tabs 34, the insulation between the positive electrode terminals 30A and the negative electrode terminals 30B of the adjacent plurality of battery cells 30, as well as the insulation between the positive electrode terminals 30A and the negative electrode terminals 30B of the battery cell 30 itself, can be well ensured.

[0070] Furthermore, the main body 26A of the busbar 26 embedded in the cover 24 is more than twice the thickness of the main body 26A from the upper surface and the side surface of the cover 24. Therefore, compared to the case where the main body 26A of the busbar 26 embedded in the cover 24 is only separated from the upper surface and the side surface of the cover 24 by the same thickness as the main body 26A, the insulation between the positive electrode terminals 30A and the negative electrode terminals 30B of adjacent battery cells 30, as well as the insulation between the positive electrode terminals 30A and the negative electrode terminals 30B of the battery cell 30 itself, can be well ensured.

[0071] Furthermore, in the first embodiment, adjacent battery cells 30 are connected to each other by the busbar 26, but the battery cells 30 do not necessarily need to be adjacent to each other; for example, they can be connected to each other every other cell. In any case, compared to the separate configuration of the cover 24 of the battery housing 22 and the busbar 26, the limitations imposed by the busbar 26 on the layout can be alleviated.

[0072] <Second Implementation Method>

[0073] Next, the second embodiment will be described. Furthermore, the same reference numerals are used for the parts that are equivalent to those in the first embodiment described above, and detailed descriptions (including common functions) are appropriately omitted.

[0074] like Figure 7 As shown, in this second embodiment, the only difference from the first embodiment is that "a heat-conducting sheet 42, which is a heat-conducting member, is provided on the inner surface of the cover 24 and in the portion other than the portion exposing each connecting terminal 26B, and contacts the upper surface between the positive electrode terminal 30A and the negative electrode terminal 30B of the plurality of battery cells 30".

[0075] The heat-conducting sheet 42 is made of a resin sheet with insulating and heat-dissipating properties, such as silicone or acrylic resin. In the bottom view, it is formed into a roughly rectangular flat plate of a size that can completely cover the main body 26A of each busbar 26. By providing such a heat-conducting sheet 42 on the inner surface of the cover 24, the heat dissipation of each battery cell 30 can be improved compared to the case where the heat-conducting sheet 42 is not provided.

[0076] Furthermore, the heat-conducting sheet 42 may not be provided on the inner surface of the cover 24, but may be provided across the upper surface of each battery cell 30 arranged in the thickness direction. However, it is easier to assemble the battery pack 20 if the heat-conducting sheet 42 is provided on the inner surface of the cover 24. In addition, the thermal conductivity of the battery pack 20 according to the first embodiment and the second embodiment is 0.4 to 398 [W / m·K].

[0077] <Third Implementation Method>

[0078] Next, the third embodiment will be described. Furthermore, the same reference numerals are used for the parts that are equivalent to those in the first embodiment described above, and detailed descriptions (including common functions) are appropriately omitted.

[0079] like Figure 8As shown, in this third embodiment, the only difference from the first embodiment described above is that "it is configured as multiple battery modules 44 instead of multiple battery cells 30". One battery module 44 is constructed by electrically connecting multiple battery cells 30, and the illustrated battery module 44 is constructed by electrically connecting two battery cells 30 by a busbar 25.

[0080] Furthermore, in Figure 8 The battery pack 20 shown has a battery housing 22 that houses three battery modules 44. The positive electrode terminal (not shown) and negative electrode terminal (not shown) of each battery module 44 are electrically connected to the connection terminal 26B exposed from the inner surface of the cover 24 of each busbar 26. In this way, even when the battery pack 20 houses multiple battery modules 44 in the battery housing 22 instead of multiple battery cells 30, it can achieve the same effect as the first embodiment described above.

[0081] <Fourth Implementation>

[0082] Next, the fourth embodiment will be described. Furthermore, the same reference numerals are used for the parts that are equivalent to those in the first embodiment described above, and detailed descriptions (including common functions) are appropriately omitted.

[0083] like Figure 9 As shown, in this fourth embodiment, the only difference from the first embodiment described above is that "the cover 24 is composed of a cover body 24A and an outer part 24B, the cover body 24A has an inner surface facing the plurality of battery cells 30, and the outer part 24B is formed of a resin material (e.g., polybutylene terephthalate) with high strength relative to the resin material (e.g., polyamide) used to form the cover body 24A, and covers at least one of the surfaces of the cover body 24A other than the inner surface".

[0084] The busbar 26, the detection line 27, and the thermostat 28 are embedded in the cover body 24A. A portion of the detection line 27 is led out to the outside through a hole 24C formed in the side wall of the outer part 24B and electrically connected to the detector 40. Furthermore, the upper surface (outer surface) of the outer part 24B is in full contact with the cooler 18 under a predetermined pressure.

[0085] If the outer part 24B of the cover 24 is constructed using a high-strength resin material with a higher strength than the cover body 24A, the rigidity of the cover 24 can be improved, and warping of the cover 24 can be more effectively suppressed or prevented. Therefore, even if the cover 24 is thin, insufficient strength and insufficient sealing of the cover 24 can be more effectively suppressed or prevented.

[0086] Furthermore, the outer part 24B of the cover 24 may not be made of a high-strength resin material, but rather of a heat-resistant resin material with higher heat resistance than the cover body 24A. Alternatively, the outer part 24B of the cover 24 may not be made of a high-strength resin material, but rather of a metal or the like with higher thermal conductivity than the resin layer formed therefrom.

[0087] <Fifth Implementation>

[0088] Next, the fifth embodiment will be described. Furthermore, the same reference numerals are used for the parts that are equivalent to those in the first embodiment described above, and detailed descriptions (including common functions) are appropriately omitted.

[0089] like Figure 10 As shown, in this fifth embodiment, the busbar 26 is entirely embedded in the cover portion 24, and the shape of the electrode terminals of each battery cell 30 differs from that in the first embodiment. Specifically, in this fifth embodiment, not only is the main body 26A of the busbar 26 embedded in the cover portion 24, but the connection terminal 26B is also embedded in the cover portion 24. Furthermore, at least a portion of the connection terminal 26B is exposed to the inner surface of the cover portion 24 through a hole 24D formed at a predetermined depth in the cover portion 24.

[0090] On the other hand, no connecting tabs 34 are provided on the positive electrode terminals 30A and negative electrode terminals 30B of each battery cell 30, and each positive electrode terminal 30A and each negative electrode terminal 30B protrudes upward at a predetermined height. Furthermore, each positive electrode terminal 30A and each negative electrode terminal 30B of each battery cell 30 is inserted into a hole 24D and electrically connected to a connecting terminal 26B. In this fifth embodiment with such a configuration, the same effects as in the first embodiment described above can be achieved.

[0091] Furthermore, since each positive electrode terminal 30A and each negative electrode terminal 30B of each battery cell 30 is inserted into each hole 24D, the connectivity between each positive electrode terminal 30A and each negative electrode terminal 30B and the busbar 26 can be improved, and the cooling performance of each positive electrode terminal 30A and each negative electrode terminal 30B can be improved. Moreover, by having holes 24D in the cover 24, the battery cells 30 can be easily positioned during the manufacture of the battery pack 20.

[0092] <Sixth Implementation>

[0093] Next, the sixth embodiment will be described. Furthermore, the same reference numerals are used for the parts that are equivalent to those in the first embodiment described above, and detailed descriptions (including common functions) are appropriately omitted.

[0094] like Figure 11As shown, in this sixth embodiment, the difference from the first embodiment is that "the cooler 18 is positioned on the outer side of the vehicle width direction (shown as the right side) such that the contact surface with the outer surface of the cover 24 faces inward in the vehicle width direction." In other words, in this sixth embodiment, the battery pack 20 is positioned horizontally with its cover 24 facing outward in the vehicle width direction (shown as the right side).

[0095] In this sixth embodiment with such a configuration, the same effect as in the first embodiment described above can be achieved. That is, since the busbar 26 is embedded in the cover 24 of the battery housing 22, the outer surface of the cover 24 can directly contact the cooler 18. Therefore, compared to a configuration where the cover 24 and the busbar 26 of the battery housing 22 are separate, the cooling efficiency of the battery pack 20 can be improved.

[0096] <Seventh Implementation>

[0097] Finally, the seventh embodiment will be described. Furthermore, the same reference numerals are used for the parts that are equivalent to those in the first embodiment described above, and detailed descriptions (including common functions) are appropriately omitted.

[0098] like Figure 12A As shown, in this seventh embodiment, the difference from the first embodiment is that "a plurality of battery cells 50 located at the center of the front-rear direction inside the battery housing 22 (three are simply shown in the figure)" and "the busbar 46 that electrically connects each positive electrode terminal 50A to each other and the busbar 48 that electrically connects each negative electrode terminal 50B to each other are independently (with insulation) embedded in the cover portion 24".

[0099] Specifically, such as Figure 12B As shown, regarding the busbar 46 that electrically connects the positive electrode terminals 50A to each other, its main body 46A is embedded in the cover portion 24 in a manner that does not expose to the outside and has no gaps, while its connecting terminal 46B protrudes from the inner surface of the cover portion 24. Similarly, regarding the busbar 48 that electrically connects the negative electrode terminals 50B to each other, at the position separated from the busbar 46, its main body 48A is embedded in the cover portion 24 in a manner that does not expose to the outside and has no gaps, while its connecting terminal 48B protrudes from the inner surface of the cover portion 24.

[0100] Furthermore, in this seventh embodiment, since each battery cell 50 is concentrated on one side of the battery housing 22 in the front-rear direction, each busbar 46 and each busbar 48 is respectively concentrated on the other side of the cover 24 in the front-rear direction. That is, each busbar 46 and 48 is embedded in approximately half of the area of ​​the cover 24 in the front-rear direction. Because of this configuration where each busbar 46 and 48 is embedded in the cover 24, even complex busbar-shaped conductive circuits can be flexibly implemented.

[0101] Furthermore, in this seventh embodiment with such a configuration, the same effects as in the first embodiment described above can be achieved. That is, since each busbar 46, 48 is embedded in the cover 24 of the battery housing 22, heat exchange with the cooler 18 can be carried out efficiently. Therefore, compared to a configuration where the cover 24 of the battery housing 22 and the busbar 46 are separate, the cooling efficiency of the battery pack 20 can be improved.

[0102] The battery pack 20 of this embodiment has been described above based on the accompanying drawings. However, the battery pack 20 of this embodiment is not limited to the configuration shown in the drawings, and appropriate design changes can be made without departing from the spirit of this disclosure. For example, the battery module 44 in the third embodiment can also be applied to other embodiments. In addition, the detector 40 can also be disposed inside the battery housing 22.

[0103] Alternatively, in each of the battery cells 30 in embodiments 1 to 4 and 6, the connecting tabs 34 may not be provided. That is, it may be configured such that the positive electrode terminal 30A and the negative electrode terminal 30B in each battery cell 30 are directly in contact with the connection terminal 26B of the busbar 26 and electrically connected.

[0104] Alternatively, the battery pack can be configured such that multiple battery cells (not shown) with positive and negative electrode terminals separately disposed on the lower surface side are housed in the battery housing 22. In this case, the busbar 26 can be embedded in the bottom wall of the battery housing 22, and the cooler 18 can be disposed in a manner that contacts the lower surface of the bottom wall of the battery housing 22 (for example, disposed on the upper surface of the flat plate portion 16A of the support platform 16).

[0105] Furthermore, in the battery cell 30 according to this embodiment, the positive electrode terminal 30A and the negative electrode terminal 30B are disposed on one side (upper surface) separately, but this is not a limitation. For example, in... Figure 11 In the case of the horizontally positioned battery pack 20 shown, it can also be configured as a battery cell with a positive electrode terminal on one side and a negative electrode terminal on the opposite side (illustration omitted).

[0106] In this case, the busbar 26 can also be embedded in the wall portion of the battery housing 22 on the side opposite to the cover portion 24 (the wall portion corresponding to the bottom wall of the battery housing 22 in the first embodiment), and the cooler 18 can also be added to the left side of the figure in such a way that it contacts the outer surface of the wall portion. Alternatively, in this case, the cooler 18 can also be configured to contact the upper surface of the cover portion 24, etc.

Claims

1. A battery pack, comprising: Multiple battery cells or multiple battery modules, each having a positive electrode terminal and a negative electrode terminal; A battery casing that houses the plurality of battery cells or the plurality of battery modules; The cover, made of an insulator, is positioned relative to the battery casing; as well as The busbar has a main body and connecting terminals. The main body is embedded in the cover, and the connecting terminals are disposed at the ends of the main body and protrude from the inner surface of the cover opposite to the plurality of battery cells or the plurality of battery modules. The connecting terminals are electrically connected to the positive and negative electrode terminals of the plurality of battery cells or the plurality of battery modules. The outer surface of the cover is brought into contact with the cooler.

2. The battery pack according to claim 1, The connecting terminals of the busbar are electrically connected to the positive electrode terminal and the negative electrode terminal respectively via a connecting tab, and are sized not to extend from the connecting tab.

3. The battery pack according to claim 1 or 2, The main body of the busbar embedded in the cover is more than twice the thickness of the main body from the outer surface of the cover and the side of the cover.

4. The battery pack according to claim 1 or 2, A heat-conducting member that contacts the plurality of battery cells or the plurality of battery modules is provided on the inner surface of the cover, except for the portion exposing the connection terminals.

5. The battery pack according to claim 1 or 2, The cover consists of a main body and an outer fitting. The cover body has an inner surface that faces the plurality of battery cells or the plurality of battery modules. The outer casing is formed of a high-strength material with a strength higher than that of the cover body, and covers at least one of the surfaces of the cover body other than the inner surface.

6. A battery pack, comprising: Multiple battery cells or multiple battery modules, each having a positive electrode terminal and a negative electrode terminal; A battery casing that houses the plurality of battery cells or the plurality of battery modules; The cover, made of an insulator, is positioned relative to the battery casing; as well as A busbar has a main body and connecting terminals. The main body is embedded in a cover portion, and the connecting terminals are disposed at an end of the main body and embedded in the cover portion. At least a portion of the connecting terminals is exposed through a hole formed in the cover portion. The positive and negative electrode terminals of the plurality of battery cells or the plurality of battery modules are inserted into the hole and electrically connected to the connection terminal. The outer surface of the cover is brought into contact with the cooler.

7. The battery pack according to claim 1 or 6, The entire outer surface of the cover is in contact with the cooler.

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