Battery pack

Abstract

To provide a battery pack that minimizes the reduction in strength of the pack frame while also allowing the internal space of the pack frame to be used as a gas exhaust passage. [Solution] The battery pack of the present invention is a battery pack in which a plurality of battery cells, which are elongated in the first direction, are arranged in a pack frame in a second direction perpendicular to the first direction, and a plurality of gas discharge valves provided on the end face of each of the plurality of battery cells in the first direction are arranged in a staggered pattern along the second direction, with their positions alternately offset in a third direction perpendicular to the first and second directions, and the pack frame has a hollow structure and a plurality of through holes are provided at positions corresponding to the plurality of gas discharge valves.

Description

Technical Field

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

Background Art

[0002] Patent Document 1 discloses a battery pack in which battery cells are housed in a pack frame, and the internal space of the pack frame also serves as a gas discharge path.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the battery pack disclosed in Patent Document 1, since a large number of through - holes are continuously provided in the pack frame having a hollow structure, there is room for improvement in suppressing a decrease in the strength of the pack frame that supports the weight of the battery cells.

[0005] The present invention has been made in view of the above problems, and an object thereof is to provide a battery pack that can suppress a decrease in the strength of the pack frame while also using the internal space of the pack frame as a gas discharge path.

Means for Solving the Problems

[0006] To solve the above-mentioned problems and achieve the objective, the battery pack according to the present invention is a battery pack in which a plurality of battery cells, which are elongated in the first direction, are arranged in a pack frame in a second direction perpendicular to the first direction, wherein a plurality of gas discharge valves provided on the end face of each of the plurality of battery cells in the first direction are arranged in a staggered pattern along the second direction, with their positions alternately offset in a third direction perpendicular to the first and second directions, and the pack frame has a hollow structure and is provided with a plurality of through holes at positions corresponding to the plurality of gas discharge valves.

[0007] As a result, the battery pack according to the present invention can utilize the internal space of the pack frame as a gas exhaust passage while suppressing a decrease in the strength of the pack frame.

[0008] Furthermore, in the above, the plurality of gas discharge valves may be provided only at one end of each of the plurality of battery cells in the first direction.

[0009] This allows for a reduction in the strength of the pack frame compared to the case where multiple through holes are located at the same position in the third direction and are continuously provided in the second direction on one end side in the first direction of the pack frame.

[0010] Furthermore, in the above, the plurality of battery cells may be arranged in an alternating pattern in the second direction, with the battery cell having the gas discharge valve on one end in the first direction and the battery cell having the gas discharge valve on the other end in the first direction, and the plurality of gas discharge valves provided on one end in the first direction arranged in a staggered pattern with respect to each other, and the plurality of gas discharge valves provided on the other end in the first direction arranged in a staggered pattern with respect to each other.

[0011] This allows for the provision of multiple through-holes in a staggered arrangement, distributed between one end and the other end of the pack frame in the first direction, thereby suppressing a decrease in the strength of the pack frame. [Effects of the Invention]

[0012] The battery pack according to the present invention has the effect of suppressing a decrease in the strength of the pack frame while also allowing the internal space of the pack frame to be used as a gas exhaust passage. [Brief explanation of the drawing]

[0013] [Figure 1] Figure 1 is a diagram showing the schematic configuration of a battery pack according to Embodiment 1. [Figure 2] Figure 2 is a perspective view showing the left end of a plurality of battery cells according to Embodiment 1. [Figure 3] Figure 3 is a perspective view showing the pack frame according to Embodiment 1. [Figure 4] Figure 4 shows a gas exhaust passage formed in the internal space of the left side frame. [Figure 5] Figure 5 is a perspective view showing the left end of a plurality of battery cells according to Embodiment 2. [Figure 6] Figure 6 is a perspective view showing the right end of a plurality of battery cells according to Embodiment 2. [Figure 7] Figure 7 is a perspective view showing the pack frame according to Embodiment 2. [Modes for carrying out the invention]

[0014] (Embodiment 1) Embodiment 1 of the battery pack according to the present invention will be described below. However, the present invention is not limited to this embodiment.

[0015] Figure 1 is a diagram showing the schematic configuration of a battery pack 1 according to Embodiment 1.

[0016] The battery pack 1 according to Embodiment 1 is configured such that a plurality of battery cells 3A, 3B, 3C, 3D, 3E, 3F, 3G, and 3H are housed within a pack frame 2.

[0017] The plurality of battery cells 3A, 3B, 3C, 3D, 3E, 3F, 3G, 3H are rectangular cells that are long in the width direction, which is the first direction of the battery pack 1. The plurality of battery cells 3A, 3B, 3C, 3D, 3E, 3F, 3G, 3H are arranged in order from the rear side to the front side in the front-rear direction (second direction) orthogonal to the width direction (first direction) of the battery pack 1 so that their respective longitudinal directions are along the width direction of the battery pack 1, namely, the battery cell 3A, the battery cell 3B, the battery cell 3C, the battery cell 3D, the battery cell 3E, the battery cell 3F, the battery cell 3G, the battery cell 3H. In the following description, when the battery cells 3A, 3B, 3C, 3D, 3E, 3F, 3G, 3H are not particularly distinguished, they are simply referred to as battery cells 3.

[0018] The pack frame 2 is configured in a rectangular shape with a front end frame 20 of a hollow structure, a rear end frame 21 of a hollow structure, a left side frame 22 of a hollow structure, and a right side frame 23 of a hollow structure connected to each other. The front end frame 20 and the rear end frame 21 extend in the width direction of the battery pack 1 respectively and face each other in the front-rear direction of the battery pack 1. The left side frame 22 and the right side frame 23 extend in the front-rear direction of the battery pack 1 respectively and face each other in the width direction of the battery pack 1. A hollow extrusion material is used for the front end frame 20, the rear end frame 21, the left side frame 22, and the right side frame 23.

[0019] The left side frame 22 and the right side frame 23 are configured to support both ends in the longitudinal direction of the plurality of battery cells 3A, 3B, 3C, 3D, 3E, 3F, 3G, 3H respectively. The front end frame 20 and the rear end frame 21 are configured to support the plurality of battery cells 3A, 3B, 3C, 3E, 3F, 3G, 3H by sandwiching them in the front-rear direction of the battery pack 1.

[0020] FIG. 2 is a perspective view showing the left end portions of the plurality of battery cells 3A, 3B, 3C, 3D, 3E, 3F, 3G, 3H according to Embodiment 1.

[0021] As shown in Figure 2, the multiple battery cells 3A, 3B, 3C, 3D, 3E, 3F, 3G, and 3H according to Embodiment 1 have left end faces 30A, 30B, 30C, 30D, 30E, 30F, 30G, and 30H on the left side (one end side) in the width direction of the battery pack 1. Electrode terminals 31A, 31B, 31C, 31D, 31E, 31F, 31G, and 31H are provided in the center in the height direction of the battery pack 1, respectively, on the left end faces 30A, 30B, 30C, 30D, 30E, 30F, 30G, and 30H. The height direction of the battery pack 1 is a third direction perpendicular to the first direction, the width direction, and the second direction, the front-to-back direction.

[0022] Furthermore, gas exhaust valves 32A, 32B, 32C, 32D, 32E, 32F, 32G, and 32H are provided on the left end faces 30A, 30B, 30C, 30D, 30E, 30F, 30G, and 30H, respectively. In the following description, when gas exhaust valves 32A, 32B, 32C, 32D, 32E, 32F, 32G, and 32H are not specifically distinguished, they will simply be referred to as gas exhaust valve 32. The gas exhaust valve 32 is composed of a rupture disc that ruptures and releases gas (smoke) when the internal pressure of the battery cell 3 rises, for example, due to a short circuit occurring in the case of the battery cell 3. The battery cell 3 can prevent the internal pressure of the case from becoming excessive by releasing gas from inside the case through the gas exhaust valve 32.

[0023] Multiple gas exhaust valves 32A, 32B, 32C, 32D, 32E, 32F, 32G, and 32H are arranged in a staggered pattern along the longitudinal direction of the battery pack 1, with their positions alternately shifted above and below the battery pack 1 in the height direction. Specifically, in the front-to-back direction of the battery pack 1, from the rear to the front, gas exhaust valve 32A is positioned above electrode terminal 31A, gas exhaust valve 32B is positioned below electrode terminal 31B, gas exhaust valve 32C is positioned above electrode terminal 31C, gas exhaust valve 32D is positioned below electrode terminal 31D, gas exhaust valve 32E is positioned above electrode terminal 31E, gas exhaust valve 32F is positioned below electrode terminal 31F, gas exhaust valve 32G is positioned above electrode terminal 31G, and gas exhaust valve 32H is positioned below electrode terminal 31H.

[0024] Figure 3 is a perspective view showing the pack frame 2 according to Embodiment 1.

[0025] In the inner wall 220 of the left side frame 22, multiple through holes 221A, 221B, 221C, 221D, 221E, 221F, 221G, and 221H are provided at positions corresponding to multiple gas exhaust valves 32A, 32B, 32C, 32D, 32E, 32F, 32G, and 32H. When no particular distinction is made between the multiple through holes 221A, 221B, 221C, 221D, 221E, 221F, 221G, and 221H, they are simply referred to as through holes 221.

[0026] Figure 4 shows the gas exhaust passages 222 and 223 formed in the internal space of the left side frame 22.

[0027] The internal space of the left side frame 22 has two gas exhaust passages 222 and 223, which are divided vertically in the height direction of the battery pack 1. Of the multiple through holes 221, the through holes 221A, 221C, 221E, and 221G located on the upper side in the height direction of the battery pack 1 are in communication with the upper gas exhaust passage 222. Also, of the multiple through holes 221, the through holes 221B, 221D, 221F, and 221H located on the lower side in the height direction of the battery pack 1 are in communication with the lower gas exhaust passage 223. The pack frame 2 is also provided with an exhaust valve 41 for discharging the gas (smoke) flowing through the two gas exhaust passages 222 and 223 to the outside. Note that the exhaust valve for discharging the gas (smoke) to the outside may be shared by the gas exhaust passages 222 and 223 and only one valve may be provided, or two valves may be provided corresponding to the gas exhaust passages 222 and 223 respectively.

[0028] In the battery pack 1 according to Embodiment 1, a plurality of through holes 221A, 221B, 221C, 221D, 221E, 221F, 221G, and 221H are provided in the inner wall 220 of the left side frame 22 in an alternating staggered arrangement on the upper and lower sides in the height direction of the battery pack 1. That is, in the front-to-back direction of the battery pack 1, from the rear to the front, through hole 221A is on the upper side, through hole 221B is on the lower side, through hole 221C is on the upper side, through hole 221D is on the lower side, through hole 221E is on the upper side, through hole 221F is on the lower side, through hole 221G is on the upper side, and through hole 221H is on the lower side.

[0029] As a result, in the battery pack 1 according to Embodiment 1, the height positions of the multiple through holes 221 are the same, and compared to the case where they are continuously provided in the longitudinal direction (front-to-back direction of the battery pack 1) on the inner wall 220 of the left side frame 22, the reduction in strength of the left side frame 22, and consequently the reduction in strength of the pack frame 2, can be suppressed. Therefore, the battery pack 1 according to Embodiment 1 can use the internal space of the pack frame 2 as gas exhaust passages 222 and 223 while suppressing the reduction in strength of the pack frame 2.

[0030] In the battery pack 1 according to Embodiment 1, gas discharge valves 32A, 32B, 32C, 32D, 32E, 32F, 32G, 32H are provided only on the left end faces 30A, 30B, 30C, 30D, 30E, 30F, 30G, 30H of the multiple battery cells 3A, 3B, 3C, 3D, 3E, 3F, 3G, 3H, but the invention is not limited to this. That is, in the battery pack 1 according to Embodiment 1, multiple gas discharge valves may be provided in a staggered arrangement only on the right end faces of the multiple battery cells 3A, 3B, 3C, 3D, 3E, 3F, 3G, 3H that are on the right side (other end side) in the width direction of the battery pack 1. In this case, multiple through holes can be provided in a staggered arrangement in the right side frame 23 at positions corresponding to the multiple gas discharge valves, and the hollow interior of the right side frame 23 can be used as a gas discharge passage.

[0031] (Embodiment 2) Embodiment 2 of the battery pack according to the present invention will be described below. In Embodiment 2, descriptions similar to those in Embodiment 1 will be omitted as appropriate.

[0032] Figure 5 is a perspective view showing the left end of a plurality of battery cells 3A, 3B, 3C, 3D, 3E, 3F, 3G, and 3H according to Embodiment 2.

[0033] As shown in Figure 5, in the plurality of battery cells 3B, 3D, 3F, 3H according to Embodiment 2, gas discharge valves 32B, 32D, 32F, 32H are provided on the left end faces 30B, 30D, 30F, 30H located on the left side (one end side) in the width direction of the battery pack 1.

[0034] Multiple gas exhaust valves 32B, 32D, 32F, and 32H are arranged alternately in a staggered pattern along the front-to-back direction of the battery pack 1, and on the upper and lower sides in the height direction of the battery pack 1. That is, in the front-to-back direction of the battery pack 1, from the rear to the front, gas exhaust valve 32B is positioned below electrode terminal 31B, gas exhaust valve 32D is positioned above electrode terminal 31D, gas exhaust valve 32F is positioned below electrode terminal 31F, and gas exhaust valve 32H is positioned above electrode terminal 31H.

[0035] Figure 6 is a perspective view showing the right ends of multiple battery cells 3A, 3B, 3C, 3D, 3E, 3F, 3G, and 3H according to Embodiment 2.

[0036] The multiple battery cells 3A, 3B, 3C, 3D, 3E, 3F, 3G, and 3H according to Embodiment 2 have right end faces 33A, 33B, 33C, 33D, 33E, 33F, 33G, and 33H on the right side (other end side) in the width direction of the battery pack 1. Electrode terminals 34A, 34B, 34C, 34D, 34E, 34F, 34G, and 34H are provided in the center in the height direction of the battery pack 1, respectively, on the right end faces 33A, 33B, 33C, 33D, 33E, 33F, 33G, and 33H.

[0037] Furthermore, as shown in Figure 6, the multiple battery cells 3A, 3C, 3E, 3G according to Embodiment 2 are provided with gas discharge valves 35A, 35C, 35E, 35G on their right end faces 33A, 33C, 33E, 33G. In the following description, when gas discharge valves 35A, 35C, 35E, 35G are not specifically distinguished, they will simply be referred to as gas discharge valve 35. Similar to gas discharge valve 32, gas discharge valve 35 is composed of a rupture disc that ruptures and releases gas (smoke) when the internal pressure of the battery cell 3 rises, for example, due to a short circuit occurring in the case of the battery cell 3.

[0038] Multiple gas exhaust valves 35A, 35C, 35E, and 35G are arranged alternately in a staggered pattern along the front-to-back direction of the battery pack 1, and on the upper and lower sides in the height direction of the battery pack 1. That is, in the front-to-back direction of the battery pack 1, from the rear to the front, gas exhaust valve 35A is positioned above electrode terminal 34A, gas exhaust valve 35C is positioned below electrode terminal 34C, gas exhaust valve 35E is positioned above electrode terminal 34E, and gas exhaust valve 35G is positioned below electrode terminal 34G.

[0039] Figure 7 is a perspective view showing the pack frame 2 according to Embodiment 2.

[0040] In the inner wall 220 of the left side frame 22, multiple through holes 221B, 221D, 221F, and 221H are provided at positions corresponding to the gas exhaust valves 32B, 32D, 32F, and 32H of multiple battery cells 3B, 3D, 3F, and 3H, respectively. The multiple through holes 221B, 221D, 221F, and 221H are provided in the inner wall 220 of the left side frame 220 in an alternating staggered arrangement on the upper and lower sides in the height direction of the battery pack 1. That is, in the front-to-back direction of the battery pack 1, from the rear to the front, through hole 221B is on the lower side, through hole 221D is on the upper side, through hole 221F is on the lower side, and through hole 221H is on the upper side.

[0041] As a result, in the battery pack 1 according to Embodiment 2, the height positions of the multiple through holes 221B, 221D, 221F, and 221H are the same, and the reduction in strength of the left side frame 22 can be suppressed compared to the case where they are continuously provided in the longitudinal direction (front-to-back direction of the battery pack 1) on the inner wall 220 of the left side frame 220.

[0042] Furthermore, in the battery pack 1 according to Embodiment 2, the multiple through holes 221B, 221D, 221F, and 221H are in communication with gas discharge passages (not shown) formed in the internal space of the left side frame 22 (for example, gas discharge passages 222 and 223 shown in Figure 4). The gas (smoke) ejected from the gas discharge valves 32B, 32D, 32F, and 32H of the multiple battery cells 3B, 3D, 3F, and 3H flows through the gas discharge passages in the left side frame 22 via the through holes 221B, 221D, 221F, and 221H and is discharged to the outside from the exhaust valve 41 provided on the pack frame 2.

[0043] Furthermore, in the inner wall 230 of the right side frame 23, multiple through holes 231A, 231C, 231E, and 231G are provided at positions corresponding to the gas discharge valves 35A, 35C, 35E, and 35G of the multiple battery cells 3A, 3C, 3E, and 3G, respectively. The multiple through holes 231A, 231C, 231E, and 231G are provided in the inner wall 230 of the right side frame 23 in an alternating staggered arrangement on the upper and lower sides in the height direction of the battery pack 1. That is, in the front-to-back direction of the battery pack 1, from the rear to the front, through hole 231A is on the upper side, through hole 231C is on the lower side, through hole 231E is on the upper side, and through hole 231G is on the lower side.

[0044] As a result, in the battery pack 1 according to Embodiment 2, the height positions of the multiple through holes 231A, 231C, 231E, and 231G are the same, and the reduction in strength of the right side frame 23 can be suppressed compared to the case where they are continuously provided in the longitudinal direction (front-to-back direction of the battery pack 1) on the inner wall 230 of the right side frame 230.

[0045] Furthermore, in the battery pack 1 according to Embodiment 2, the multiple through holes 231A, 231C, 231E, and 231G communicate with a gas discharge passage (not shown) formed in the internal space of the right side frame 23. The gas (smoke) ejected from the gas discharge valves 35A, 35C, 35E, and 35G of the multiple battery cells 3A, 3C, 3E, and 3G flows through the gas discharge passage in the right side frame 23 via the through holes 231A, 231C, 231E, and 231G, and is discharged to the outside through the exhaust valve 42 provided on the pack frame 2.

[0046] In the battery pack 1 according to Embodiment 2, through holes 221 and 231 are distributed between the left side frame 22 and the right side frame 23, and the through holes 221 and 231 are arranged in a staggered pattern along the front-to-back direction of the battery pack 1, with their positions offset from each other on the upper and lower sides in the height direction of the battery pack 1. As a result, in the battery pack 1 according to Embodiment 2, the density of through holes 221 and 231 can be reduced in the inner wall 220 of the left side frame 22 and the inner wall 230 of the right side frame 23, respectively, thereby suppressing a decrease in the strength of the left side frame 22 and the right side frame 23, and consequently, a decrease in the strength of the pack frame 2. Therefore, the battery pack 1 according to Embodiment 2 can use the internal space of the pack frame 2 as a gas exhaust passage while suppressing a decrease in the strength of the pack frame 2. [Explanation of symbols]

[0047] 1 Battery pack 2-pack frame 3 battery cells 20 Front end frame 21 Rear end frame 22 Left side frame 23 Right side frame 32,35 Gas discharge valve 41,42 Exhaust valve 220,230 Inner wall 221,231 through holes 222,223 Gas discharge channels

Claims

1. A battery pack in which multiple battery cells, each elongated in the first direction, are arranged in a pack frame in a second direction perpendicular to the first direction, The multiple gas discharge valves provided on the end face of each of the multiple battery cells in the first direction are arranged in a staggered pattern along the second direction, with their positions alternately offset in a third direction perpendicular to the first and second directions. The pack frame has a hollow structure and is provided with multiple through holes at positions corresponding to the multiple gas discharge valves. A battery pack characterized by the following features.

2. The plurality of gas discharge valves are provided only on one end side in the first direction of each of the plurality of battery cells. The battery pack according to feature 1.

3. The plurality of battery cells are arranged in an alternating pattern in the second direction, with each battery cell having the gas discharge valve on one end in the first direction and each battery cell having the gas discharge valve on the other end in the first direction. The plurality of gas discharge valves provided at one end in the first direction are arranged in a staggered pattern relative to each other. The plurality of gas discharge valves provided on the other end side in the first direction are arranged in a staggered pattern relative to each other. The battery pack according to feature 1.

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