Battery pack

Abstract

Provided is a battery pack (1) comprising: batteries (battery modules (10)); an electronic device; a bus bar (50) that electrically connects the batteries (battery modules (10)) to each other or the batteries (battery modules (10)) to the electronic device; a lower housing (3b) that accommodates the batteries (battery modules (10)), the electronic device, and the bus bar (50); an upper housing (3a) that covers the lower housing; and a cover member (40) that is positioned between the upper housing (3a) and the bus bar (50) and covers the entire bus bar (50).

Description

Battery Pack

[0001] The present invention relates to a battery pack.

[0002] A technique of covering the bus bars of a battery module from above to protect the bus bars from heat when high-temperature gas is generated inside the battery pack is disclosed in, for example, Patent Document 1.

[0003] International Publication No. 2025 / 014186

[0004] Inside the battery pack, a plurality of bus bars are provided that connect battery modules to each other or connect battery modules to electronic equipment (e.g., a junction box). During installation, the bus bars are fastened to connection targets by means such as screwing. To ensure electrical conduction, the bus bars are fastened such that an elastic force acts on them. For example, in a situation where the battery pack overheats and a short circuit occurs in a bus bar, the fastening of the bus bar may come loose, causing the bus bar to spring up and contact the upper casing (also referred to as an upper cover), which may damage the upper casing. Damage to the upper casing leads to progressive damage to the battery pack.

[0005] An example of the object of the present invention is to provide a technique that prevents a bus bar from damaging the upper casing even when the connection of the bus bar is released.

[0006] The present invention provides the following technologies: 1. A battery pack comprising: a battery; an electronic device; a busbar electrically connecting the batteries to each other or the batteries to the electronic device; a lower housing housing the batteries, the electronic device and the busbar; an upper housing covering the lower housing; and a cover member positioned between the upper housing and the busbar, covering the entire busbar. 2. The battery pack according to 1, wherein the cover member is a cured product of a resin composition. 3. The battery pack according to 1 or 2, wherein the cover member is attached to the battery. 4. A first battery group having multiple batteries, a second battery group having multiple batteries, an electronic device connected to the first battery group or the second battery group, a first busbar connecting the first battery group and the second battery group, a second busbar connecting the first battery group and the second battery group or the electronic device, the first busbar having a first portion (A) connected to a first terminal portion (A) of the second battery group and a second portion (A) extending in the height direction, the second busbar having a first portion (B) connected to a first terminal portion (B) of the first battery group and a second portion (B) extending in the height direction, a lower housing housing the first battery group, the second battery group, the electronic device, the first busbar and the second busbar, an upper housing covering the lower housing, A battery pack comprising: an upper housing; and a cover member located between the first busbar and the second busbar, covering at least the first portion (A) and the second portion (A) of the first busbar and the first portion (B) and the second portion (B) of the second busbar. 5. The battery pack according to 4, wherein it has a signal line connected to the first battery group, the signal line being lower than the lowest point of the first portion (A) of the first busbar and higher than the lowest point of the second portion (A) of the first busbar, and the cover member being located between the first busbar and the signal line. 6. The battery pack according to 4 or 5, wherein the upper housing has a recess, the recess having a portion facing the second portion (A) of the first busbar, the lowest point of the recess being lower than the lowest point of the first portion (A) of the first busbar, and the cover member being located between the recess of the upper housing and the first busbar.7. The battery pack according to any one of 4 to 6, wherein the first battery group has a first discharge section capable of discharging gas in the event of an abnormality, the second battery group has a second discharge section capable of discharging gas in the event of an abnormality, the first busbar intersects with a linear path virtually connecting the first discharge section and the second discharge section, and the cover member is positioned between the second discharge section and the first busbar. 8. The battery pack according to 7, wherein the first busbar has a third section (A) connected to the second section (A) of the first busbar, a fourth section (A) connected to the third section (A) and extending in the height direction, and a fifth section (A) connected to the second terminal of the first battery group, and the cover member covers all of the first to fifth sections (A) of the first busbar. 9. The battery pack according to 8., wherein the second busbar has a third portion (B) connected to the second portion (B) of the second busbar, a fourth portion (B) connected to the third portion (B) and extending in the height direction, and a fifth portion (B) connected to the second terminal of the second battery group, and the cover member covers all of the first to fifth portions (B) of the second busbar. 10. The battery pack according to any one of 7 to 9., wherein the cover member is positioned between the first discharge portion and the first busbar. 11. The battery pack according to any one of 7 to 10., wherein the cover member further covers the first terminal portion (B) of the first battery group. 12. The battery pack according to any one of 7 to 11., wherein the cover member has an opening provided above the first terminal portion (B) of the first battery group and a blocking portion extending downward from the vicinity of the opening on the second battery group side. 13. The battery pack according to 12, wherein the blocking portion has a first portion higher than the cover member and a second portion lower than the cover member. 14. The battery pack according to any one of 7 to 13, wherein the cover member has an opening at the end on the side of the first terminal portion of the first battery group. 15. The battery pack according to any one of 7 to 13, wherein the cover member is attached to the first battery group and the second battery group.

[0007] According to the above-described aspect of the present invention, a technology is provided that prevents the busbar from damaging the upper housing even when the busbar connection is disconnected.

[0008] This is a schematic perspective view of a battery pack according to the first embodiment. This is an enlarged view showing the area where the busbars (first busbar, second busbar), the electronic equipment (junction box) connected by them, and the cover member are provided according to the first embodiment. This is a view showing the cover member of Figure 2 according to the first embodiment, separated. This is a cross-sectional view illustrating the positional relationship in the thickness direction of the busbars provided between battery modules, the cover member provided on the upper part of the busbars, and the upper housing according to the first embodiment. This is a cross-sectional view illustrating the positional relationship in the thickness direction of the busbars provided between battery modules, the cover member provided on the upper part of the busbars, and the upper housing according to the second embodiment. This is a cross-sectional view illustrating the positional relationship in the thickness direction of the busbars provided between battery modules, the cover member provided on the upper part of the busbars, and the upper housing according to the third embodiment. This is a cross-sectional view illustrating the positional relationship in the thickness direction of the busbars provided between battery modules, the cover member provided on the upper part of the busbars, and the upper housing according to the fourth embodiment. This is a plan view illustrating the positional relationship of the battery module, busbars, and cover member according to the fifth embodiment. This is a plan view illustrating the positional relationship of the battery module, busbars, and cover member according to the sixth embodiment. This is a plan view illustrating the positional relationship between the battery module, busbar, and cover member according to the seventh embodiment.

[0009] Embodiments of the present invention will be described below with reference to the drawings. In all drawings, similar components are denoted by the same reference numerals, and their descriptions are omitted where appropriate.

[0010] <First Embodiment> (Battery Pack 1) Figure 1 is a schematic perspective view of the battery pack 1 according to this embodiment. Here, the elements housed in the housing 3 of the battery pack 1 are shown by dashed lines. Figure 2 is a perspective view showing the state with the housing 3 removed from Figure 1, and shows the area where two battery modules 10 (first battery module 10A, second battery module 10B), bus bars 50 (first bus bar 50a, second bus bar 50b), and cover member 40 are provided. Figure 3 is a perspective view showing the cover member 40 separated from Figure 2. Figure 4 is a cross-sectional view illustrating the positional relationship in the thickness direction between the bus bars 50 provided between the battery modules 10, the cover member 40 provided on the upper part of the bus bars 50, and the upper housing 3a. In this embodiment, the battery pack 1 may have a structure in which cells are directly incorporated into the battery pack 1, in addition to a structure in which multiple battery modules 10 are incorporated. Therefore, in the former structure, the battery module 10 can be defined as a "battery," and in the latter structure, the cell can be defined as a "battery." The former structure will be illustrated below.

[0011] Battery pack 1 is installed in a vehicle. Specifically, battery pack 1 is installed between the front and rear wheels of the vehicle. Unless otherwise specified, the following description assumes that battery pack 1 is installed in a vehicle. However, battery pack 1 can also be used for applications other than automobiles.

[0012] Each figure shows the X, Y, and Z directions for explanatory purposes. The X direction indicates the front-to-back direction of the battery pack 1. The Y direction is perpendicular to the X direction. The Y direction indicates the left-to-right direction of the battery pack 1. The Z direction is perpendicular to both the X and Y directions. The Z direction indicates the up-to-down direction of the battery pack 1. The arrows pointing to the X, Y, and Z directions indicate the front, left, and up directions of the battery pack 1, respectively. However, the relationship between the X, Y, and Z directions and the front-to-back, left-to-right, and up-to-down directions of the battery pack 1 is not limited to this example.

[0013] In the first embodiment, the front-rear, left-right, and up-down directions of the battery pack 1 are determined by the vehicle on which the battery pack 1 is mounted. The X, Y, and Z directions represent the front-rear, left-right, and up-down directions of the vehicle, respectively. The arrows pointing to the X, Y, and Z directions represent the front, left, and up directions of the vehicle, respectively. However, the relationship between the front-rear, left-right, and up-down directions of the battery pack 1 and the front-rear, left-right, and up-down directions of the vehicle is not limited to this example.

[0014] The battery pack 1 comprises a housing 3, a plurality of battery modules 10, a junction box (not shown), a bus bar 50, and a cover member 40.

[0015] (Housing 3) Housing 3 is formed from plates made of metal, resin, or a composite material thereof. Housing 3 has an upper housing 3a, a lower housing 3b, a front housing 3c, a rear housing 3d, a right housing 3e, and a left housing 3f. Multiple battery modules 10, a junction box, a bus bar 50, and a cover member 40 are mounted on the upper side of the lower housing 3b. The upper housing 3a covers them from above, and the front housing 3c, rear housing 3d, right housing 3e, and left housing 3f cover the front, back, left, and right sides.

[0016] (Battery Module 10 (First Battery Module 10A, Second Battery Module 10B)) The battery module 10 consists of two rectangular parallelepipeds, the first battery module 10A and the second battery module 10B, arranged in the front-to-back direction (X direction). The first battery module 10A is located at the rear, and the second battery module 10B is located at the front. When the first battery module 10A and the second battery module 10B are not distinguished, they are referred to as "battery module 10". However, the number and arrangement of the battery modules 10 included in the battery pack 1 are not limited to this example.

[0017] The battery modules 10 (first battery module 10A, second battery module 10B) are mounted on the upper surface of the lower housing 3b. Each battery module 10 includes a plurality of battery cells (not shown) stacked in the X direction (or Y direction), and a housing case that contains these battery cells. For example, each battery module 10 has multiple battery cell groups, each containing multiple battery cells connected in parallel, connected in series. Alternatively, multiple single battery cells may be connected in series.

[0018] (Bus bar 50) The bus bar 50 electrically connects the battery modules 10 to each other, or to the battery modules 10 and the electronic equipment mounted on the battery pack 1. In this embodiment, a configuration in which the battery modules 10 are connected to each other by the bus bar 50 is illustrated. The electronic equipment includes a junction box. The junction box is, for example, provided on the top surface of the housing of the battery module 10, and is equipped with relay circuits, voltage detection circuits, fuses, etc., and is used to electrically connect the battery modules 10 to each other or to electrically connect the battery modules 10 to external devices.

[0019] The busbar 50 comprises a busbar body 51 and a covering member 52. The busbar body 51 is, for example, a conductive, plate-shaped metal member, and its shape is changed by bending or other means to become an appropriate shape depending on the arrangement of the objects to be connected and the shape of other structures between them.

[0020] The covering member 52 is an insulating member provided on the surface of the busbar body 51. The covering member 52 is not provided at both ends of the busbar body 51, and the metal surface is exposed. The exposed end will be described as the first terminal portion 55, and the other as the second terminal portion 56. For example, the first terminal portion 55 is the terminal at the rear (-X direction) in the figure and is connected to the first battery module 10A. The second terminal portion 56 is the terminal at the front (+X direction) in the figure and is connected to the second battery module 10B. The connection terminals between the first battery module 10A and the second battery module 10B are omitted.

[0021] For example, as shown in Figure 4, the first terminal portion 55 and the second terminal portion 56 have terminal openings 57 that penetrate in the vertical direction. The busbar 50 is fastened to the battery module 10 by bolts 90, with the terminal holes 15 and terminal openings 57 provided on the upper surface 11 of the battery module 10 aligned.

[0022] The insulating member is, for example, a cured product of a resin composition. As the resin composition, for example, a thermosetting resin can be used. The thermosetting resin is not particularly limited, but examples include phenolic resins such as novolac-type phenolic resin and resol-type phenolic resin; epoxy resins such as bisphenol-type epoxy resin and novolac-type epoxy resin; nitrogen-containing resins such as aniline resin, melamine resin, urea resin, and cyanate resin; ketone resin; unsaturated polyester resin; urethane resin or furan resin. Furthermore, these may be modified products obtained by modifying them with various components. The thermosetting resin may contain inorganic fillers (fillers, etc.) and other materials as appropriate.

[0023] By using thermosetting resins, high heat resistance can be achieved in resin molded products. Heat resistance can be adjusted, for example, by adjusting the type and content of inorganic fillers.

[0024] As shown in the cross-sectional view of Figure 4, the busbar 50 of this embodiment is bent in a concave shape between the first battery module 10A and the second battery module 10B, along the first battery module 10A, the lower housing 3b, and the second battery module 10B. More specifically, the busbar 50 extends forward (+X direction) from the position of the first terminal portion 55, bends downward (-Z direction) beyond the front surface 12 of the first battery module 10A, extends further to near the lower housing 3b, bends forward (+X direction) along the lower housing 3b, and then bends upward (+Z direction), extends along the back surface 13 of the second battery module 10B, bends forward (+X direction) beyond the upper surface 11 of the second battery module 10B, and the second terminal portion 56 is exposed.

[0025] (Cover member 40) The cover member 40 is positioned between the upper housing 3a and the bus bar 50, and when viewed from above (from the +Z direction), it covers the entire bus bar 50. In other words, for example, when loaded into a vehicle, when viewed from above, the cover member 40 covers (overlaps) the entire bus bar 50. The same is true when viewed from a direction perpendicular to the main surface of the lower housing 3b (i.e., the surface on which the battery module 10 is mounted). With this configuration, for example, even if a short circuit occurs and the fastening of the bus bar 50 comes undone, causing the bus bar 50 to spring upward (in the +Z direction), it is possible to prevent the bus bar 50 from contacting and damaging the upper housing 3a.

[0026] The cover member 40 is provided to conform to the shape of the busbar 50 when it is attached to the battery module 10 (particularly the shape of the upper side). In other words, it is a plate-shaped member formed in a concave shape in cross-section, similar to the shape of the busbar 50. The cover member 40 is designed not to come into contact with the busbar 50.

[0027] The shape of the cover member 40 is not limited to the concave cross-section shown in Figure 4. Various structures can be adopted as long as they cover the busbar 50 when viewed from above. For example, it may have a shape that extends linearly in the front-to-back direction when viewed in cross-section. In addition, in the left-to-right direction (Y direction), part may be concave and part may be linear. Various shapes can be adopted as appropriate depending on the shape of the busbar 50 covered by the cover member 40, and the shape and arrangement of components such as harnesses (cables) placed below the cover member 40.

[0028] For example, the front surface 12 of the first battery module 10A and the back surface 13 of the second battery module 10B may be provided with outlets to discharge high-temperature gas generated inside the battery module 10. If the harness is exposed to high-temperature gas, the cover material of the harness may melt and be damaged. Therefore, by routing the harness above the cover member 40, it is possible to prevent such high-temperature gas from damaging the harness. When routing the harness inside the cover member 40, a rib may be provided on the underside of the cover member 40 (towards the lower housing 3b) so as to be positioned between the harness and the gas outlet. The rib allows the high-temperature gas to be guided in the appropriate direction without coming into contact with the harness. In other words, the cover member 40 constitutes a flow path for the high-temperature gas. This eliminates the need to protect heat-sensitive components such as the harness with a heat-resistant sheet. In this case, since the cover member 40 is above the harness, it is possible to prevent the harness from coming into contact with the upper housing 3a.

[0029] Both ends of the cover member 40 (hereinafter referred to as the cover end 44) ​​are provided with cover fastening holes 49 for attaching to the screw holes 19 of the battery module 10 with screws 91. That is, by aligning the cover fastening holes 49 with the screw holes 19 and fastening them with screws 91, the cover member 40 is fixed to the battery module 10 (first battery module 10A, second battery module 10B).

[0030] The cover member 40 is formed from, for example, metal, resin, or a composite thereof. From the viewpoint of insulation performance, freedom of shape, and light weight, a resin member is preferably used as the cover member 40. From the viewpoint of cost, a cured thermoplastic resin is preferable as the resin member, and from the viewpoint of heat resistance, a cured thermosetting resin is preferable.

[0031] The cover member 40 has sufficient strength to prevent it from penetrating and damaging the upper housing 3a when it springs up and makes contact with the bus bar 50 due to the impact. This strength is appropriately adjusted depending on the material, thickness, and shape of the cover member 40.

[0032] In the above description, the cover member 40 covered the entire busbar 50, but this is not necessarily the only option. If the part of the busbar 50 that tends to spring up can be identified, that part should be covered, and the cover member 40 may not cover parts that do not come into contact with the upper housing 3a. For example, the first terminal portion 55 and the second terminal portion 56 are considered to have a strong tendency to spring up if one of the fastenings comes undone. Therefore, in particular, the upper parts of the first terminal portion 55 and the second terminal portion 56 should always be covered, and a shape may be adopted in which the cover member 40 is not provided above the intermediate portion where contact with the upper housing 3a is not expected. Furthermore, the cover member 40 may be constructed so that the strength of the upper part of the first terminal portion 55 and the second terminal portion 56 is increased, while the strength of other parts is not increased as much (for example, they may be made thinner).

[0033] <Second Embodiment> The second embodiment will be described with reference to Figure 5. In the following description, we will focus on the differences from the first embodiment, and the same parts will be omitted as appropriate. Figure 5 is a diagram corresponding to Figure 4 of the first embodiment, and is a cross-sectional view illustrating the positional relationship in the thickness direction of the busbar 50 provided between the battery modules 10 of this embodiment, the cover member 40 provided on the upper part of the busbar 50, the signal line 80, and the upper housing 3a.

[0034] The parts of the busbar 50 are defined as follows: The busbar 50 has a first part 151, a second part 152, a third part 153, a fourth part 154, and a fifth part 155. The first part 151 is the part that connects to the terminal part of the second battery module 10B and has a second terminal part 56. The second part 152 is the part that bends downward from the first part 151, extends in the height direction, and connects to the third part 153. The second part 152 faces the back surface 13 of the second battery module 10B. The third part 153 is the part that connects to the second part 152, extends horizontally, and connects to the fourth part 154. The fourth part 154 is the part that connects to the third part 153, bends upward, extends in the height direction, and connects to the fifth part 155. The fifth portion 155 is the portion that connects to the terminal portion of the first battery module 10A and has a first terminal portion 55. In other words, the fifth portion 155 connects to the fourth portion 154, extends in a horizontally bent direction, and connects to the terminal portion of the first battery module 10A.

[0035] The signal line 80 is the harness described above and is arranged in the cover recess 42 of the cover member 40. The signal line 80 includes a temperature sensor line 81 and a voltage signal line 82. The temperature sensor line 81 is housed in a signal line housing section 81a, which is a cured resin composition with a U-shaped cross-section. The voltage signal line 82 is housed in a signal line housing section 81a, which is a cured resin composition with a U-shaped cross-section. These cured resin compositions can be, for example, those exemplified as the material for the cover member 40. By housing and routing the temperature sensor line 81 and the voltage signal line 82 in the signal line housing sections 81a and 82a, respectively, the paths of the temperature sensor line 81 and the voltage signal line 82 can be stabilized. As a result, it is possible to prevent the temperature sensor line 81 and the voltage signal line 82 from shifting and interfering with surrounding members. In addition, since the signal line 80 is arranged in the cover recess 42, the recessed shape can be effectively utilized, saving space.

[0036] The cover member 40 has a cover recess 42. The cover recess 42 has a portion that faces the second portion 152 of the bus bar 50. In other words, the portion of the cover recess 42 that extends vertically faces the second portion 152. The lowest point of the cover recess 42 is lower than the lowest point of the first portion 151 of the bus bar 50. The cover member 40 is located between the plate recess 30 of the upper housing 3a and the bus bar 50.

[0037] The signal line 80 is lower than the lowest points of the first portion 151 and the fifth portion 155 of the bus bar 50, and higher than the lowest point of the second portion 152 of the bus bar 50. In other words, the uppermost part of the signal line 80 is lower than the upper surfaces 11 of the first battery module 10A and the second battery module 10B, which are the connection points between the bus bar 50 and the battery module 10. Also, the lowermost part of the signal line 80 is higher than the lowest point of the bus bar 50. The cover member 40 is located between the bus bar 50 and the signal line 80.

[0038] The battery module 10 has a gas outlet 17 (also called an outlet) on its side. Specifically, the first battery module 10A has a gas outlet 17 on its front surface 12. The second battery module 10B has a gas outlet 17 on its back surface 13. The gas outlet 17 is closed when the battery pack 1 is operating properly, and opens when high-temperature gas is generated inside and the pressure exceeds a predetermined level, allowing the high-temperature gas to be discharged. In the event of a battery malfunction such as overheating, the high-temperature gas ejected from the gas outlet 17 on the side may hit the signal line 80. As in this embodiment, the presence of a cover member 40 between the signal line 80 and the gas outlet 17 prevents the high-temperature gas from directly hitting the signal line 80 even if it is ejected from the gas outlet 17. Furthermore, even if the busbar 50 is short-circuited and springs up, it is possible to prevent the busbar 50 from hitting the signal line 80.

[0039] <Third Embodiment> The third embodiment will be described with reference to Figure 6. In the following description, we will focus on the differences from the first and second embodiments, and will omit explanations of similar parts as appropriate. Figure 6 is a cross-sectional view illustrating the positional relationship in the thickness direction of the busbar 50 provided between the battery modules 10 of this embodiment, the cover member 40 provided on the upper part of the busbar 50, the signal line 80, and the upper housing 3a. The difference from the second embodiment is that the cover member 40 is provided with a busbar mounting opening 45 that penetrates vertically through the upper part of the bolt 90. There are no particular restrictions on the size and shape of the busbar mounting opening 45, but for example, it is a rectangular shape large enough that the entire upper end of the bolt 90 can be seen when viewed from above. The presence of the busbar mounting opening 45 allows high-temperature gas ejected from the gas outlet 17 in the event of a battery abnormality such as overheating to be efficiently discharged from the busbar mounting opening 45. The part where the bolt 90 is provided is often the highest position on the cover member 40. By providing the busbar mounting opening 45 in such a location, it is possible to prevent high-temperature gas from accumulating.

[0040] The opening edge of the busbar mounting opening 45 has a blocking portion 70 that extends in the height direction. The blocking portion 70 is, for example, a rib-shaped member. The blocking portion 70 may be, for example, integrally formed with the busbar mounting opening 45, or it may be attached as a separate member. When high-temperature gas is generated, the blocking portion 70 functions as a means of rectifying the high-temperature gas, promoting the discharge of the high-temperature gas upward from the busbar mounting opening 45. Specifically, the blocking portion 70 reduces the flow of high-temperature gas, especially from the terminal hole 15, towards the busbar, and promotes its flow upward from the busbar mounting opening 45 to the battery pack 1. In this embodiment, the blocking portion 70 has a first portion 71 that extends upward from the busbar mounting opening 45, i.e., the cover member 40, and a second portion 72 that extends downward. However, the blocking portion 70 may consist only of the second portion 72 that extends downward, or only of the first portion 71 that extends upward.

[0041] <Fourth Embodiment> A fourth embodiment will be described with reference to FIG. 7. In the following description, focus will be placed on points different from the first to third embodiments, and descriptions of similar parts will be omitted as appropriate. FIG. 7 is a diagram corresponding to FIG. 5 of the second embodiment, and is a cross-sectional view illustrating the positional relationship in the thickness direction of the bus bars 50 provided between the battery modules 10 of the present embodiment, the cover member 40 provided on the upper part of the bus bars 50, the signal line 80, and the upper housing 3a.

[0042] The difference from the second embodiment lies in that the upper housing 3a has a plate recess 30. This makes it possible to increase the available space.

[0043] The plate recess 30 has a vertically extending surface 33 that is a portion facing the second portion 152 of the bus bar 50, and a vertically extending surface 34 that faces the fourth portion 154. The vertically extending surfaces 33 and 34 are surfaces whose cross sections extend in the height direction. The height direction is not necessarily limited to the vertical direction; the cross section may be in an oblique direction, as long as it has a component extending in the vertical direction. The bottom surface 31, which is the lowest point of the plate recess 30, is lower than the lowest point of the first portion 151 of the bus bar 50. In other words, the plate recess 30 enters the cover recess 42 of the cover member 40. The cover member 40 is located between the plate recess 30 of the upper housing 3a and the bus bar 50. Further, the position of the gas discharge port 17 in the height direction is at a position higher than the bottom surface 31 of the plate recess 30.

[0044] The bottom surface 31 of the plate recess 30 is lower than the upper surface 11 of the upper housing 3a, or the upper surface of the module, or the joining position of the external connection terminal of the module, or the exhaust port of the module. Even when the battery module 10 is overheated and high-temperature gas is generated, the high-temperature gas is transmitted from the gas discharge port 17 through the bus bar 50 and the cover member 40, rises, and flows toward the upper housing 3a. As a result, conventionally, if the bus bar 50 was partially broken, the force of the high-temperature gas would bring the bus bar 50 into contact with the upper housing 3a, which could cause a short circuit. However, in the present embodiment, the presence of the cover member 40 can prevent such a short circuit.

[0045] <Fifth Embodiment> A fifth embodiment will be described with reference to FIG. 8. FIG. 8 is a plan view illustrating the positional relationship among a battery module 10, a bus bar 150, and a cover member 40. Here, the upper housing 3a is omitted. The present embodiment will be described by focusing on the points that differ from the first to fourth embodiments, and description of similar portions will be omitted as appropriate.

[0046] A battery pack 1 includes a housing 3 (see FIGS. 1 to 7), a plurality of battery modules 10, a junction box 60, a bus bar 150, and a cover member 40.

[0047] As illustrated, the battery pack 1 includes a lower first battery module 10A and an upper second battery module 10B. A junction box 60 is provided on the upper surface of the second battery module 10B. A plurality of gas discharge ports 17 are provided on a front surface 12 of the first battery module 10A and a back surface 13 of the second battery module 10B.

[0048] The bus bar 150 includes a first bus bar 150a, a second bus bar 150b, and a third portion 153. Similarly to the bus bar 50 of the first to fourth embodiments, the first bus bar 150a and the second bus bar 150b each have a first portion 151, a second portion 152, a third portion 153, a fourth portion 154, and a fifth portion 155, and electrically connect the first battery module 10A and the second battery module 10B.

[0049] The first bus bar 150a connects a terminal portion 252a of the second battery module 10B and a terminal portion 251a of the first battery module 10A. The second bus bar 150b connects a terminal portion 252b of the second battery module 10B and a terminal portion 251b of the first battery module 10A. A third bus bar 150c connects the junction box 60 and a second terminal portion 252b of the second battery module 10B.

[0050] The cover member 40 is located between the upper housing 3a and the first bus bar 150a and the second bus bar 150b, and has a cover member 40 that covers at least the first portion 151a and the second portion 152a of the first bus bar 150a and the first portion 151b and the second portion 152b of the second bus bar 150b. In this embodiment, it covers the entirety of the first bus bar 150a, a part of the second bus bar 150b, and a part of the third bus bar 150c. The portion of the second bus bar 150b not covered by the cover member 40 is the portion that connects to the terminal portion 61 of the junction box 60. The portion of the third bus bar 150c not covered by the cover member 40 is the portion that connects to the terminal portion 62 of the junction box 60.

[0051] The cover member 40 has a cover end 44 which is fixed to the first battery module 10A and the second battery module 10B. This cover end 44 has a first cover end 44a extending in the Y direction and a second cover end 44b extending in the X direction. In other words, the cover member 40 is fixed so as to close at both ends in the Y direction where it is fixed to the first battery module 10A and the second battery module 10B. However, near the point where the terminal portion 251a of the first battery module 10A and the first busbar 150a are connected (shown in the lower left of the figure), an opening 48 is provided in the second cover end 44b. Similarly, near the point where the terminal portion 252b of the second battery module 10B and the third busbar 150c are connected (shown in the upper right of the figure), an opening 48 is provided in the second cover end 44b. High-temperature gas is discharged through the opening 48 when it is generated. Furthermore, the first cover end 44a, which is fixed to the second battery module 10B, is provided with an opening 47 through which the second busbar 150b and the third busbar 150c, which extend to the junction box 60, pass. This opening 47 may extend slightly in a cylindrical shape toward the junction box 60.

[0052] <Sixth Embodiment> The sixth embodiment will be described with reference to Figure 9. Figure 9 is a plan view illustrating the positional relationship between the battery module 10, the busbar 150, and the cover member 40. The upper housing 3a is omitted here. This embodiment will be described focusing on the differences from the first to fifth embodiments, and similar parts will be omitted as appropriate.

[0053] The battery pack 1 includes a first battery group 101 having a plurality of battery modules 10, a second battery group 102 having a plurality of battery modules, an electronic device connected to the first battery group 101 or the second battery group 102, a first busbar 250 connecting the first battery group 101 and the second battery group 102, and a second busbar 350 connecting the first battery group 101 and the second battery group 102 or the electronic device. The electronic device is, for example, a junction box 60. Furthermore, the battery pack 1 includes a third busbar 450, a fourth busbar 550, and a fifth busbar 650. The third busbar 450 connects the terminal portion 461 of the second battery module 10B to the terminal portion 462 of the third battery module 10C. The fourth busbar 550 connects the terminal portion 561 of the first battery module 10A to the terminal portion 562 of the junction box 60. The fifth busbar 650 connects the terminal portion 651 of the junction box 60 to the terminal portion 652 of the fourth battery module 10D.

[0054] The first battery group 101 includes a first battery module 10A and a fourth battery module 10D. The second battery group 102 includes a second battery module 10B and a third battery module 10C. The number of battery modules 10 included in the first battery group 101 and the second battery group 102 is not limited to two, but may be three or more.

[0055] The first busbar 250 has a first portion (A) 251 that connects to the first terminal portion (A) 261 of the second battery group 102, and a second portion (A) 252 that extends in the height direction. The first busbar 250 has a third portion (A) 253 that connects to the second portion (A) 252 of the first busbar 250, a fourth portion (A) 254 that connects to the third portion (A) 253 and extends in the height direction, and a fifth portion (A) 255 that connects to the second terminal 262 of the first battery group 101.

[0056] The second busbar 350 has a first portion (B) 351 that connects to the first terminal portion (B) 361 of the first battery group 101, and a second portion (B) 352 that extends in the height direction. The second busbar 350 has a third portion (B) 353 that connects to the second portion (B) 352 of the second busbar 350, a fourth portion (B) 354 that connects to the third portion (B) 353 and extends in the height direction, and a fifth portion (B) 355 that connects to the second terminal 362 of the second battery group 102.

[0057] The first battery group 101, namely the first battery module 10A and the fourth battery module 10D, has a first discharge section 17a capable of releasing gas in the event of an abnormality. The second battery group 102, namely the second battery module 10B and the third battery module 10C, has a second discharge section 17b capable of releasing gas in the event of an abnormality. The connecting line between the first discharge section 17a and the second discharge section 17b intersects with the first busbar 250. In other words, for example, in the projection of the X-Y plane in Figure 9, or the projection of the X-Z plane, or the projection of the X-Y plane and the X-Z plane, the first busbar 250 is located on the straight line connecting the first discharge section 17a and the second discharge section 17b. A cover member 40 is positioned between the second discharge section 17b and the first busbar 250.

[0058] The cover member 40 is positioned to cover the space between the first battery group 101 and the second battery group 102. Here, the cover member 40 covers a part of the first bus bar 250 and a part of the second bus bar 350. Specifically, the cover member 40 covers a part of the first portion 251, the second portion 252, and the third portion 253 of the first bus bar 250. The cover member 40 also covers a part of the first portion 351, the second portion 352, and the third portion 353 of the second bus bar 350. This prevents the first bus bar 250 and the second bus bar 350 from bouncing up, as the cover member 40 stops them midway and prevents them from coming into contact with the upper housing 3a.

[0059] <Seventh Embodiment> The seventh embodiment will be described with reference to Figure 10. Figure 10 is a plan view illustrating the positional relationship between the battery module 10, the busbar 150, and the cover member 40. The upper housing 3a is omitted here. This embodiment will be described focusing on the differences from the first to sixth embodiments, and similar parts will be omitted as appropriate.

[0060] This embodiment is a modification of the sixth embodiment, in which the area covered by the cover member 40 is larger than in the sixth embodiment. Specifically, the cover member 40 covers the entirety of the first to fifth portions (A) 251 to 255 of the first bus bar 250. The cover member 40 also covers the entirety of the first to fifth portions (B) 351 to 355 of the second bus bar 350. As a result, even if the first bus bar 250 and the second bus bar 350 spring up, the cover member 40 can stop them from springing up midway, preventing them from coming into contact with the upper housing 3a.

[0061] The embodiments of the present invention have been described above with reference to the drawings, but these are merely examples of the present invention, and various other configurations can also be adopted.

[0062] This application claims priority based on Japanese Patent Application No. 2025-051905, filed on 26 March 2025, and incorporates all of its disclosures herein.

[0063] 1 Battery pack 3 Housing 3a Upper housing 3b Lower housing 10 Battery module 17 Gas outlet (outlet) 17a First outlet (first gas outlet) 17b Second outlet (second gas outlet) 30 Plate recess 40 Cover member 45 Busbar mounting opening 50, 150 Busbar 51 Busbar body 52 Covering member 55 First terminal 56 Second terminal 60 Junction box (electronic equipment) 70 Interruption section 80 Signal line 101 First battery group 102 Second battery group 150a, 250 First busbar 150b, 350 Second busbar 150c 450 Third busbar 550 Fourth busbar 650 Fifth busbar

Claims

1. A battery pack comprising: a battery; an electronic device; a busbar that electrically connects the batteries to each other or to the batteries and to the electronic device; a lower housing that houses the battery, the electronic device and to the busbar; an upper housing that covers the lower housing; and a cover member that is located between the upper housing and to the busbar and covers the entire busbar.

2. The battery pack according to claim 1, wherein the cover member is a cured product of a resin composition.

3. The battery pack according to claim 1 or 2, wherein the cover member is attached to the battery.

4. A first battery group having multiple batteries, a second battery group having multiple batteries, an electronic device connected to the first battery group or the second battery group, a first busbar connecting the first battery group and the second battery group, a second busbar connecting the first battery group and the second battery group or the electronic device, the first busbar having a first portion (A) connected to a first terminal portion (A) of the second battery group and a second portion (A) extending in the height direction, the second busbar having a first portion (B) connected to a first terminal portion (B) of the first battery group and a second portion (B) extending in the height direction, a lower housing housing the first battery group, the second battery group, the electronic device, the first busbar and the second busbar, an upper housing covering the lower housing, A battery pack comprising the upper housing and a cover member located between the first busbar and the second busbar, which covers at least the first portion (A) and the second portion (A) of the first busbar and the first portion (B) and the second portion (B) of the second busbar.

5. The battery pack according to claim 4, having a signal line connected to the first battery group, wherein the signal line is lower than the lowest point of the first portion (A) of the first busbar and higher than the lowest point of the second portion (A) of the first busbar, and the cover member is located between the first busbar and the signal line.

6. The battery pack according to claim 4 or 5, wherein the upper housing has a recess, the recess has a portion facing the second portion (A) of the first busbar, the lowest point of the recess is lower than the lowest point of the first portion (A) of the first busbar, and the cover member is located between the recess of the upper housing and the first busbar.

7. The battery pack according to claim 4 or 5, wherein the first battery group has a first discharge section capable of discharging gas in the event of an abnormality, the second battery group has a second discharge section capable of discharging gas in the event of an abnormality, the first busbar intersects with a linear path virtually connecting the first discharge section and the second discharge section, and the cover member is positioned between the second discharge section and the first busbar.

8. The battery pack according to claim 7, wherein the first busbar has a third portion (A) connected to the second portion (A) of the first busbar, a fourth portion (A) connected to the third portion (A) and extending in the height direction, and a fifth portion (A) connected to the second terminal of the first battery group, and the cover member covers all of the first to fifth portions (A) of the first busbar.

9. The battery pack according to claim 8, wherein the second busbar has a third portion (B) connected to the second portion (B) of the second busbar, a fourth portion (B) connected to the third portion (B) and extending in the height direction, and a fifth portion (B) connected to the second terminal of the second battery group, and the cover member covers all of the first to fifth portions (B) of the second busbar.

10. The battery pack according to claim 7, wherein the cover member is positioned between the first discharge section and the first bus bar.

11. The battery pack according to claim 7, wherein the cover member further covers the first terminal portion (B) of the first battery group.

12. The battery pack according to claim 7, wherein the cover member has an opening provided above the first terminal portion (B) of the first battery group and a blocking portion extending downward from the vicinity of the opening on the second battery group side.

13. The battery pack according to claim 12, wherein the blocking portion has a first portion that is higher than the cover member and a second portion that is lower than the cover member.

14. The battery pack according to claim 7, wherein the cover member has an opening at the end of the first battery group on the side of the first terminal portion.

15. The battery pack according to claim 7, wherein the cover member is attached to the first battery group and the second battery group.

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