Battery pack

Abstract

A battery pack is provided with: a battery (30) which is provided with a lid (45) as a sealing body of a positive electrode external terminal on one side in the Z direction, and which discharges internal gas from one side in the Z direction when the internal pressure rises; a first holder (50) that holds one side in the Z direction of the plurality of batteries (30) arranged side by side, and that has an opening (52) that exposes the lid (45); and a collector plate (60) which is in contact with one surface of the first holder (50), closes a part of the opening (52), and is connected to the cover (45) exposed from the opening (52). Furthermore, a groove (53) is provided in at least a portion of one surface of the first holder (50) that is in contact with the collector plate (60), and the groove (53) discharges internal gas discharged from the portion of the opening (52) that is closed by the collector plate (60) to the outside of the first holder (50).

Description

Technical Field

[0001] The present invention relates to a battery pack accommodating a plurality of batteries. Background Art

[0002] In a battery pack, a plurality of batteries are housed in an outer casing corresponding to the devices used. In the battery pack, a plurality of batteries arranged in a row are held by a holder, and the plurality of batteries are electrically connected to each other by a current collector plate (for example, Patent Document 1).

[0003] When a battery stored in a battery pack goes into thermal runaway due to some abnormality, high-temperature internal gas is discharged from the battery in thermal runaway. There is a risk that the high-temperature internal gas comes into contact with batteries held in the same holder (hereinafter referred to as peripheral batteries), causing thermal runaway of the peripheral batteries, thereby generating a thermal runaway chain reaction. Therefore, it is necessary to reliably discharge the internal gas discharged from the battery in thermal runaway to the outside of the holder without contacting the peripheral batteries.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2022-002199 Summary of the invention

[0007] In addition, in the battery, a gas discharge valve is provided on one side in the longitudinal direction. According to this structure, when thermal runaway occurs, the internal pressure of the battery rises, the gas discharge valve operates, and the internal gas is discharged from one side in the longitudinal direction. On the other hand, an external terminal is sometimes provided on one side in the longitudinal direction of the battery. Therefore, an opening for exposing the external terminal is provided on a retaining frame that holds one side in the longitudinal direction of the battery, and the external terminal exposed from the opening is connected to the collector lead of the collector plate.

[0008] In the above structure, when the internal gas of the battery is discharged, the internal gas is discharged from the opening of the holder. However, since the collector lead of the collector plate blocks part of the opening, there is a situation where part of the discharged gas is blocked by the collector lead. In recent years, due to the large-scale and high-output batteries, the wide-width collector leads have increased, and the above tendency has become significant.

[0009] At the opening of the holder, where the exhaust is blocked by the collector lead, the discharge of internal gas to the outside of the holder is blocked. Therefore, there is a risk that the high-temperature internal gas flows into the inside of the holder and contacts the surrounding batteries, causing thermal runaway of the surrounding batteries, thereby generating a thermal runaway chain reaction.

[0010] Therefore, an object of the present invention is to provide a battery pack in which high-temperature internal gas discharged from a battery can be discharged relatively easily to the outside of a holder when the battery thermally runs away.

[0011] The battery pack of the present invention comprises a battery, a holder, and a collector plate. The battery is provided with an external terminal on one side in the longitudinal direction, and internal gas is discharged from one side in the longitudinal direction when the internal pressure rises. The holder holds one side in the longitudinal direction of a plurality of batteries arranged in an arranged manner, and has an opening for exposing the external terminal. The collector plate abuts against one side of the holder, blocks a portion of the opening, and is connected to the external terminal. Furthermore, it is characterized in that a groove is provided on at least a portion of one side of the holder abutting against the collector plate, and the groove discharges the internal gas discharged from the portion of the opening blocked by the collector plate to the outside of the holder.

[0012] According to the battery pack of the present invention, high-temperature internal gas exhausted from the battery in the event of thermal runaway of the battery can be relatively easily exhausted to the outside of the holder. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a perspective view of a battery pack showing an example of an embodiment.

[0014] Figure 2 It is a cross-sectional view of a battery pack showing an example of an embodiment.

[0015] Figure 3 It is a cross-sectional view of a battery showing an example of an embodiment.

[0016] Figure 4 It is a perspective view of a retainer showing an example of an embodiment.

[0017] Figure 5 It is a perspective view showing a retainer according to another example of the embodiment. DETAILED DESCRIPTION

[0018] In the following description, specific shapes, materials, directions, numerical values, etc. are illustrative for easy understanding of the present invention and can be appropriately changed according to the application, purpose, specification, etc.

[0019] <Battery Pack>

[0020] use Figure 1 , a battery pack 10 according to an example of an embodiment will be described.

[0021] In the battery pack 10, a plurality of battery blocks 20 are housed in an outer casing 11 corresponding to the device to be used. In each battery block 20, a plurality of (in Figure 1 In the example shown, two batteries 30 are fixed to each other by a holder and housed in the outer casing 11. According to the battery pack 10, when the battery 30 thermally runs away, the high-temperature internal gas discharged from the battery 30 is relatively easily discharged to the outside of the holder, as will be described in detail later.

[0022] Hereinafter, the components will be described with the longitudinal direction of the battery 30 being the Z direction, the direction perpendicular to the Z direction and in which the batteries 30 are arranged in the battery block 20 being the X direction, and the direction perpendicular to the Z direction and the X direction being the Y direction. Figure 3 ) of the top plate, that is, the cover 45 (refer to Figure 3 ) is set as one side, and the opposite side is set as the other side.

[0023] The battery pack 10 is mainly used as a power source for power. For example, the battery pack 10 is used as a power source for electric devices driven by motors, such as electric cars, electric tools, electric assisted bicycles, electric motorcycles, electric wheelchairs, electric tricycles, and electric carts. However, the use of the battery pack 10 is not particularly limited to the above-mentioned uses, and it can also be used as a power source for various electric devices used indoors and outdoors, such as cleaners, wireless devices, lighting devices, digital cameras, and video cameras, etc., other than electric devices.

[0024] The battery pack 10 includes a battery block 20 storing a plurality of batteries 30, and a battery pack 20 storing a plurality of batteries 30. Figure 1 In the example shown, there are three outer casings 11 of the battery blocks 20 .

[0025] The battery block 20 has a plurality of batteries 30 arranged in an array. The battery pack 10 is configured to connect the plurality of battery blocks 20 in series or in parallel, and output a voltage corresponding to the device used. In the battery block 20, the plurality of batteries 30 are electrically connected to each other. In the battery block 20, the plurality of batteries 30 are connected in series or in parallel. In the battery block 20 of the present embodiment, for example, the plurality of batteries 30 are connected in parallel. The details of the battery block 20 and the batteries 30 will be described later.

[0026] The outer casing 11 is made of a metal such as aluminum and has a cylindrical shape. However, the outer casing 11 is not limited to being made of metal, and may also be made of resin. A battery pack external terminal 12 electrically connected to the battery block 20 is provided at the other end in the Z direction of the outer casing 11. When the battery pack 10 is assembled in a device that carries the battery pack 10 and is used, the battery pack external terminal 12 is used as a terminal for supplying a DC voltage. The battery pack external terminal 12 is also used when charging the battery pack 10. In addition, a vent 13 (see FIG. 1 ) is provided on the side of the outer casing 11 for discharging high-temperature internal gas discharged from the battery 30 that has thermal runaway to the outside of the battery pack 10. Figure 2 ).

[0027] <Battery Pack>

[0028] use Figure 2, a battery block 20 according to an example of an embodiment will be described.

[0029] The battery block 20 includes two batteries 30, a first holder 50, a current collector plate 60, a second holder 55, and a current collector lead 65. The first holder 50 is a holder on one side of the Z direction that holds the plurality of batteries 30. The current collector plate 60 is in contact with one surface of the first holder 50 and is in contact with a sealing body 36 (see FIG. 1 ) as a positive electrode external terminal of the battery 30 described later. Figure 3 ) is connected to the top plate, that is, the cover 45. The second holder 55 is a holder on the other side of the Z direction that holds the plurality of batteries 30. The collector lead 65 is connected to the outer can 35 (see Figure 3 ) is connected to the bottom of the battery pack 10. The collector plate 60 of the battery block 20 closest to one side in the Z direction among the plurality of battery blocks 20 connected in series in the battery pack 10 is equivalent to the total positive pole. In addition, the collector lead 65 of the battery block 20 closest to the other side in the Z direction is equivalent to the total negative pole. The collector plate 60 and the collector lead 65 are electrically connected to the battery pack external terminal 12 (not shown). The details of each of the battery 30, the first retaining frame 50 and the collector plate 60 will be described later.

[0030] <Battery>

[0031] use Figure 2 and Figure 3 , a battery 30 according to an example of an embodiment will be described.

[0032] The battery 30 is a cylindrical battery and a lithium ion battery. However, the battery 30 is not limited to a cylindrical battery and may be a square battery, a laminated battery, etc. In addition, the battery 30 may be an aqueous battery or a non-aqueous battery. As an example of a non-aqueous battery, a lithium ion battery is suitable.

[0033] like Figure 3 As shown, the battery 30 is provided with a top plate of the sealing body 36, that is, a cover 45, which serves as a positive electrode external terminal, on one side in the Z direction. Details will be described later. When thermal runaway occurs, internal gas is generated in the battery 30, and when the internal pressure rises, the internal gas is discharged from the exhaust hole 45A of the cover 45. In other words, in the battery 30, when the internal pressure rises, the internal gas is discharged from one side in the Z direction.

[0034] The battery 30 includes an electrode body 34, an electrolyte (not shown), and an outer can 35 for storing the electrode body 34 and the electrolyte. The electrode body 34 includes a positive electrode 31, a negative electrode 32, and a separator 33, and has a winding structure in which the positive electrode 31 and the negative electrode 32 are spirally wound with the separator 33 interposed therebetween. The outer can 35 has a bottomed cylindrical shape with one side open in the Z direction, and the opening of the outer can 35 is sealed by a sealing body 36.

[0035] The battery 30 has insulating plates 37 and 38 disposed above and below the electrode body 34, respectively. Figure 3 In the example shown, the positive electrode lead 39 attached to the positive electrode 31 extends to the sealing body 36 side through the through hole of the insulating plate 37, and the negative electrode lead 40 attached to the negative electrode 32 extends to the bottom side of the outer can 35 through the outside of the insulating plate 38. The positive electrode lead 39 is connected to the bottom plate of the sealing body 36, that is, the lower surface of the internal terminal plate 41, by welding or the like, and the top plate of the sealing body 36, that is, the cover 45, which is electrically connected to the internal terminal plate 41, serves as the positive electrode external terminal. The negative electrode lead 40 is connected to the bottom inner surface of the outer can 35 by welding or the like, and the bottom of the outer can 35 serves as the negative electrode external terminal.

[0036] The sealing body 36 has a structure in which an internal terminal plate 41, a lower valve body 42, an insulating member 43, an upper valve body 44, and a cover 45 are stacked in order from the electrode body 34 side. The components constituting the sealing body 36 are, for example, disc-shaped or ring-shaped, and the components except the insulating member 43 are electrically connected to each other. The lower valve body 42 and the upper valve body 44 constituting the so-called gas discharge valve are connected to each other at their respective central portions, and the insulating member 43 is interposed between the peripheral portions of the lower valve body 42 and the upper valve body 44.

[0037] In the gas discharge valve, if the internal pressure rises when the battery 30 thermally runs away, the lower valve body 42 deforms and breaks in a manner that pushes up the upper valve body 44 toward the cover 45 side. As a result, the current path between the lower valve body 42 and the upper valve body 44 is disconnected. When the internal pressure rises further, the upper valve body 44 breaks, and the internal gas is discharged from the exhaust hole 45A formed on the side of the convex portion of the cover 45. However, this is not limited to the present embodiment, and it may be a structure in which a gas discharge valve is provided on the other side in the Z direction, that is, at the bottom of the outer tank 35, so that the internal gas is discharged from the other side in the Z direction when the internal pressure rises.

[0038] <Retainer>

[0039] use Figure 2 and Figure 4 Next, the first retainer 50 and the current collector plate 60 according to an example of the embodiment will be described.

[0040] As described above, the first holding frame 50 holds one side of the two batteries 30 in the Z direction. However, the number of batteries 30 held by the first holding frame 50 is not limited to the number in the present embodiment.

[0041] The first holder 50 may be made of, for example, a highly thermally conductive PPS (polyphenylene sulfide) resin, a resin containing a heat dissipating filler, an injection moldable thermosetting resin, etc. More specifically, the first holder 50 may be made of a phenolic resin, an unsaturated polyester, or an unsaturated polyester mixed with a heat absorbent, etc. The first holder 50 may also be made of an inorganic mineral such as mica, or a material obtained by mixing an inorganic mineral such as mica into a resin material.

[0042] like Figure 4 As shown, the first holder 50 is formed in an oblong shape when viewed from the Z direction, and has a predetermined thickness in the Z direction. The first holder 50 has a storage portion 51 (see FIG. 5 ) for storing the battery 30. Figure 2 ), an opening 52 for exposing the cover 45 as the positive external terminal of the battery 30, and a groove 53 for discharging the internal gas to the outside of the first holder 50 when the internal pressure of the battery 30 rises. The details of the groove 53 will be described later.

[0043] like Figure 2 As shown, the storage portion 51 is formed on the other side of the first holder 50 in the Z direction. The storage portion 51 is formed to be circular when viewed from the other side in the Z direction and to be a recessed portion when viewed from the X direction or the Y direction. The end of one side of the battery 30 in the Z direction is fitted into the storage portion 51, and one side of the battery 30 is held in the storage portion 51.

[0044] like Figure 2 and Figure 4 As shown, the opening 52 is formed to penetrate the storage portion 51. In more detail, the opening 52 is formed as a circular hole whose diameter is smaller than the diameter of the circular shape of the storage portion 51 when viewed from the other side in the Z direction. In addition, the center of the storage portion 51 and the center of the opening 52 are formed to be the same center. According to the opening 52, the top plate of the sealing body 36, that is, the cover 45, which serves as the positive external terminal of the battery 30, can be exposed, and the cover 45 can be connected to the collector plate 60. In addition, according to the opening 52, the high-temperature internal gas discharged from the battery 30 when the battery 30 thermally runs away can be discharged to the outside of the first retaining frame 50.

[0045] <Current collector>

[0046] like Figure 4 As shown, the collector plate 60 abuts against one surface of the first holder 50 in the Z direction and is connected to the cover 45 as the positive external terminal of the battery 30. More specifically, the collector plate 60 connects the covers 45 as the positive external terminals of the batteries 30 held in the first holder 50. The collector plate 60 is made of a metal plate such as an aluminum plate or a copper plate. The collector plate 60 has a main body 61 abutting against one surface of the first holder 50 and a collector lead 62 connected to the cover 45.

[0047] Here, the opening 52 through which the cover 45 as the positive external terminal of the first battery 30 of the two batteries 30 is exposed is set as the first opening 52, and the opening 52 through which the cover 45 as the positive external terminal of the second battery 30 is exposed is set as the second opening 52. In this case, the main body 61 abuts against one surface of the first holder 50 between the first opening 52 and the second opening 52 of the first holder 50. The main body 61 is connected to a current collecting lead 65 (not shown) connected to the negative terminal of the other battery block 20. The current collecting lead 62 is formed continuously with the main body 61 at both ends of the main body 61 in the X direction, and is electrically connected to the cover 45 by welding.

[0048] When the internal pressure of the battery 30 rises during thermal runaway of the battery 30, the internal gas is discharged from the exhaust hole 45A of the cover 45, and the internal gas is discharged from the opening 52 of the first holder 50. However, since a part of the opening 52 is blocked by the current collecting lead 62 of the current collecting plate 60, a part of the internal gas to be discharged may be blocked by the current collecting lead 62.

[0049] At the portion where the discharge of the internal gas is blocked by the collector lead 62, the discharge of the internal gas to the outside of the first holder 50 is blocked. Therefore, there is a risk that the high-temperature internal gas flows into the inside of the first holder 50 and contacts the battery 30 held inside the first holder 50 as a peripheral battery, causing the battery 30 held inside the first holder 50 to thermally run away, thereby generating a thermal runaway chain reaction. Therefore, in the present embodiment, at the portion where the discharge of the internal gas is blocked by the collector lead 62, the internal gas is discharged to the outside of the first holder 50 using the groove 53 described later.

[0050] <Trough>

[0051] The groove 53 is formed on one surface of the first holder 50 in the Z direction. In addition, the groove 53 is formed on at least the portion of the surface of the first holder 50 in the Z direction that contacts the collector plate 60. In addition, the groove 53 is formed on the portion that contacts the collector plate 60, which is referred to here as the groove 53 being formed on the portion of the surface of the first holder 50 that contacts the collector plate 60, means that the groove 53 is provided on the portion of the surface of the first holder 50 that overlaps with the collector plate 60 when viewed from one side. In addition, the case where the groove 53 is formed on at least the portion that contacts the collector plate 60 includes the case where the groove 53 is formed only on the portion that contacts the collector plate 60, and the case where the groove 53 is formed on both the portion that contacts the collector plate 60 and the portion that does not contact the collector plate 60. More specifically, the groove 53 connects the portion of the opening 52 blocked by the collector lead 62 with the portion of the surface of the first holder 50 that does not contact the collector plate 60. Here, the portion of the opening 52 blocked by the collector lead 62 refers to the space of the opening 52 sandwiched between the collector lead 62 and the cover 45.

[0052] More specifically, the groove 53 has a first straight portion 53A extending along the X direction and a second straight portion 53B extending along the Y direction.

[0053] The first straight portion 53A is covered by the current collector plate 60, and is formed linearly from the portion of the opening 52 blocked by the current collector lead 62 to the terminal portion 54 along the X direction. The terminal portion 54 is provided between the first opening 52 and the second opening 52, and is in contact with the current collector plate 60. That is, it can be said that the first straight portion 53A is formed linearly from the peripheral portion of the first opening 52 to the terminal portion 54 along the X direction. It can also be said that the first straight portion 53A is formed linearly from the peripheral portion of the second opening 52 to the terminal portion 54 along the X direction. Here, for example, when the internal gas is discharged from the first battery 30, the internal gas is guided by the first straight portion 53A. Since the terminal portion 54 is formed between the first opening 52 and the second opening 52, the internal gas introduced into the first straight portion 53A does not contact the second battery 30 through the second opening 52, but is discharged to the outside of the first holder 50.

[0054] The second straight portion 53B is connected to the first straight portion 53A, and is formed in a straight line from the terminal portion 54 of the first straight portion 53A along the Y direction. In addition, the middle portion 53C of the second straight portion 53B is covered by the collector plate 60, and both end portions 53D are exposed from the collector plate 60. However, the cross-sectional shape, length, width, number of grooves 53 are not limited to the present embodiment.

[0055] According to the groove 53, when the battery 30 thermally runs away, the internal gas discharged from the battery 30 is not blocked by the collector lead 62 but discharged to the outside of the first holder 50. As a result, when one battery 30 of the battery block 20 thermally runs away, the internal gas flows into the inside of the first holder 50, which can prevent the battery 30 held inside the first holder 50 as a peripheral battery from thermally running away. That is, it is easy to avoid the occurrence of a thermal runaway chain.

[0056] In addition, the position where the groove 53 is formed is not limited to the position in the present embodiment. For example, in the case of a structure in which a gas discharge valve is provided on the other side in the Z direction, that is, at the bottom of the outer tank 35, and the internal gas is discharged from the other side in the Z direction when the internal pressure rises, the groove 53 may be provided in the second retaining frame 55.

[0057] Summary

[0058] The battery pack 10 of the present embodiment includes a battery 30, a first holder 50 (holder), and a collector plate 60. The battery 30 is provided with a top plate of a sealing body 36, that is, a cover 45 (external terminal), which serves as a positive electrode external terminal, on one side in the Z direction (length direction), and internal gas is discharged from a vent 45A of the cover 45 when the internal pressure rises. The first holder 50 holds one side in the Z direction of the plurality of batteries 30 arranged in an array, and has an opening 52 that exposes the cover 45. The collector plate 60 abuts against one side of the first holder 50, blocks a portion of the opening 52, and is connected to the cover 45. A groove 53 is provided in at least a portion of a side of the first holder 50 that abuts against the collector plate 60, and the groove 53 discharges the internal gas discharged from the portion of the opening 52 blocked by the collector plate 60 to the outside of the first holder 50.

[0059] By setting the above structure, when the battery 30 thermally runs away, the internal gas discharged from the battery 30 is not blocked by the collector lead 62, but is discharged to the outside of the first holder 50 through the groove 53. As a result, it is possible to suppress the situation where the high-temperature internal gas flows into the inside of the first holder 50 when one battery 30 of the battery block 20 thermally runs away. Therefore, it is possible to suppress the situation where the high-temperature internal gas flows into the inside of the first holder 50 and contacts the battery 30 held inside the first holder 50 as a peripheral battery, causing the battery 30 held inside the first holder 50 to thermally run away. That is, it is easy to avoid the occurrence of a thermal runaway chain.

[0060] <Other embodiments>

[0061] use Figure 5 Next, a first retainer 70 and a current collector plate 80 according to another example of the embodiment will be described.

[0062] like Figure 5 As shown, the first holder 70 has a storage portion (not shown), an opening 72, and a groove 73 for discharging the internal gas to the outside of the first holder 70 when the internal pressure of the battery 30 rises. The storage portion and the opening 72 are the same as the storage portion 51 and the opening 52 of the first holder 50, so the description thereof is omitted. In addition, the details of the groove 73 will be described later.

[0063] The collector plate 80 abuts against one surface of the first holder 70 and is connected to the cover 45 as the positive external terminal of the battery 30. More specifically, the collector plate 80 connects the covers 45 as the positive external terminals of the batteries 30 held in the first holder 70. The collector plate 80 is made of a metal plate such as an aluminum plate or a copper plate. The collector plate 80 has a main body 81 abutting against one surface of the first holder 70 in the Z direction and a collector lead 82 connected to the cover 45.

[0064] The main body 81 is substantially the same shape as the oblong shape of the first holder 70 when viewed from the Z direction, and abuts against one side of the first holder 70. The main body 81 has an opening 83 formed at a position corresponding to the opening 72 of the first holder 70. In addition, the main body 81 is connected to the current collector lead 65 connected to the negative terminal of the other battery block 20. The shape, size, etc. of the main body 81 are not limited to those in the present embodiment, and may be the shape, size, etc. of at least a portion of the one side of the first holder 70 that includes the opening 72.

[0065] The current collecting leads 82 extend from the edge of the opening 83 and are electrically connected to the cover 45 by welding to the cover 45. The current collecting leads 82 extend from the edge of the opening 83 at the same phase position. In the present embodiment, the current collecting leads 82 extend from the edge of one side of the opening 83 in the X direction.

[0066] The grooves 73 are formed in a plurality of positions on one surface of the first holder 70 in the Z direction (in Figure 5 In the example shown, there are two grooves. In addition, each groove 73 is formed in a portion of one side of the first retainer 70 that contacts the current collector plate 80. Each groove 73 connects a portion of the opening 72 blocked by the current collector lead 82 with a portion of the opening 72 adjacent to the opening 72 that is not blocked by the current collector plate 80.

[0067] According to the groove 73, the internal gas discharged from the battery 30 when the battery 30 thermally runs away will not be blocked by the collector lead 82 but will be discharged to the outside of the first holder 70 from the adjacent opening 72. Thus, it is possible to avoid the following situation: when one battery 30 of the battery block 20 thermally runs away, the high-temperature internal gas flows into the inside of the first holder 70, and the high-temperature internal gas flows into the inside of the first holder 70 and contacts the battery 30 held inside the first holder 50, causing the battery 30 held inside the first holder 50 to thermally run away, thereby generating a thermal runaway chain reaction.

[0068] In addition, the present invention is not limited to the above-described embodiment and its modified examples, and it goes without saying that various changes and improvements can be made within the scope of the matters described in the claims of the present application.

[0069] Description of Reference Numerals

[0070] 10. Battery pack; 11. Outer casing; 12. External terminal of battery pack; 13. Vent hole; 20. Battery block; 30. Battery; 31. Positive electrode; 32. Negative electrode; 33. Separator; 34. Electrode body; 35. Outer can; 36. Sealing body; 37. Insulating plate; 38. Insulating plate; 39. Positive electrode lead; 40. Negative electrode lead; 41. Internal terminal plate; 42. Lower valve body; 43. Insulating member; 44. Upper Valve body; 45, cover (positive external terminal); 45A, exhaust hole; 50, first retaining frame; 51, storage portion; 52, 72, 83, opening; 53, groove; 53A, first straight portion; 53B, second straight portion; 54, terminal portion; 55, second retaining frame; 60, collector plate; 61, main body; 62, 65, 82, collector lead; 70, first retaining frame; 73, groove; 80, collector plate; 81, main body.

Claims

1. A battery pack, wherein: The battery pack has: A battery having an external terminal on one side in the length direction, and discharging internal gas from the one side in the length direction when the internal pressure rises; a holder that holds one side in the length direction of the plurality of batteries arranged in an array and has an opening for exposing the external terminals; as well as a collector plate which abuts against one surface of the retainer, closes a portion of the opening, and is connected to the external terminal; A groove is provided at least at a portion of one surface of the holder that contacts the current collector plate. The groove discharges the internal gas discharged from the portion of the opening blocked by the current collector plate to the outside of the holder.

2. The battery pack according to claim 1, wherein: The groove allows a portion of the opening blocked by the current collector plate to communicate with a portion of one surface of the holder that is not in contact with the current collector plate.

3. The battery pack according to claim 1, wherein: The groove allows a portion of the opening blocked by the current collector plate to communicate with a portion of an opening adjacent to the opening that is not blocked by the current collector plate.

Images