Battery pack

Abstract

The utility model provides a battery pack can inhibit the deterioration of shell. The battery pack includes: battery unit, has the pressure relief valve for discharging the gas that produces in the battery unit inside, heat -resistant material is opposite setting with the pressure relief valve of battery unit, and shell is used for containing battery unit and heat -resistant material to have the clearance, wherein, heat -resistant material has the gas flow path of bending shape, and this gas flow path extends from the area opposite the pressure relief valve in one main surface of battery unit side, to the area opposite the clearance of shell in another main surface of shell side.

Description

Technical Field

[0001] This disclosure relates to a battery pack. Background Technology

[0002] In non-aqueous electrolyte secondary batteries such as lithium-ion batteries, gas may be generated due to overcharging, causing the internal pressure (internal pressure) inside the battery cell housing to rise. To ensure safety in the face of rising internal pressure, a pressure relief valve is provided in the battery housing, for example. This valve opens when the internal pressure reaches or exceeds a specified pressure, releasing the gas inside the battery to the outside. This suppresses the rise in internal pressure. Alternatively, instead of a pressure relief valve, a gap is provided at the joint surface of the battery cell housing to release the gas inside the battery to the outside. However, since the gas generated inside the battery is at a high temperature, directly releasing this high-temperature gas to the outside could potentially cause deterioration of the gas release path or components outside the battery pack.

[0003] A solution to this problem is disclosed, for example, in Patent Document 1. The battery pack disclosed in Patent Document 1 prevents the gas discharged from the battery cell from violently ejected from the casing by sealing the gaps at the joint surfaces of the casing with a heat-resistant material.

[0004] Patent Document 1: International Publication No. 2020 / 129596

[0005] In the battery pack disclosed in Patent Document 1, the gap at the shell joint surface is merely sealed by heat-resistant material. Therefore, when the high-temperature gas discharged from the pressure relief valve of the battery cell directly impacts the area outside the shell joint surface where no heat-resistant material is provided, it may cause partial structural deterioration of the shell. Utility Model Content

[0006] This disclosure was made to address such problems and aims to provide a battery pack capable of suppressing the degradation of the casing.

[0007] The battery pack disclosed herein includes: a battery cell having a pressure relief valve for discharging gas generated inside the battery cell; a heat-resistant material disposed opposite to the pressure relief valve of the battery cell; and a housing for housing the battery cell and the heat-resistant material, having a gap, wherein the heat-resistant material has a bent gas flow path extending from a region on one main surface of the battery cell opposite to the pressure relief valve to a region on another main surface of the housing opposite to the gap of the housing. Thus, according to the battery pack of this disclosure, by discharging gas discharged from the pressure relief valve of each battery cell through the bent gas flow path provided in the heat-resistant material to the outside of the housing, the heat of the gas can be prevented from directly impacting the inside of the housing, thereby suppressing housing degradation caused by gas heat. Furthermore, according to the battery pack of this disclosure, since the temperature of the gas discharged to the outside of the housing can be reduced, degradation of external devices caused by gas heat can also be suppressed.

[0008] In the above embodiment, the housing has a bent gap that extends from the area opposite to the outlet of the gas flow path formed on the other main surface of the heat-resistant material in the inner surface of the housing to the outer surface of the housing.

[0009] In the above embodiment, the housing includes an upper cover and a lower housing, and the gap between the housing is disposed at the joint surface of the upper cover and the lower housing.

[0010] In the above embodiment, the heat-resistant material has an inlet for the gas flow path at the position where the distance between it and the pressure relief valve is shortest on one of the main surfaces of the battery cell side.

[0011] In the above embodiment, the gap of the housing has a pressure regulating mechanism that opens the valve orifice when the pressure exceeds a specified limit.

[0012] According to this disclosure, a battery pack that can suppress casing degradation can be provided. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the battery pack involved in Embodiment 1.

[0014] Figure 2 This is a partial enlarged view of the battery pack involved in Embodiment 1.

[0015] Figure 3 This is a partial enlarged view of the battery pack involved in Embodiment 2.

[0016] Figure 4 This is a schematic diagram of the battery pack involved in Embodiment 3.

[0017] Figure 5 This is a partial enlarged view of the joint surface between the upper cover and the lower housing in the battery pack according to Embodiment 3. Detailed Implementation

[0018] The embodiments involved in this disclosure will be described below with reference to the accompanying drawings. Figure 1 This is a schematic diagram of the battery pack 1 according to Embodiment 1. The battery pack 1 has multiple battery cells 2, heat-resistant material 3, and a housing 4. The battery pack 1 can be used as a power source for a vehicle's drive motor. In this disclosure, the case where the battery pack 1 houses multiple battery cells 2 is described as an example, but it is not limited to this; the battery pack 1 may also house a single battery cell 2. The various components of the battery pack 1 will be described in detail below.

[0019] Each battery cell 2 is a rechargeable and dischargeable secondary battery. For example, each battery cell 2 can be a lithium-ion battery or a nickel-metal hydride battery. Each battery cell 2 has, for example, a cuboid shape, with its shorter side along a first horizontal direction (X-axis direction) and its longer side along a second direction perpendicular to the first horizontal direction (Y-axis direction). Multiple battery cells 2 are arranged within the housing 4 along the first direction (X-axis direction). Furthermore, the multiple battery cells 2 are electrically connected to each other. Each battery cell 2 is equipped with a pressure relief valve 21.

[0020] The pressure relief valve 21 is a safety valve used to release flammable gases generated inside the battery cell 2 to the outside of the battery cell 2. For example, in the event of overcharging or internal short circuit in the battery cell 2, flammable gases may be generated from the electrolyte in the battery cell 2, causing the internal pressure of the battery cell to rise. To ensure safety relative to the rise in internal pressure of the battery cell 2, the pressure relief valve 21 opens its valve orifice when the internal pressure of the battery cell 2 reaches or exceeds a specified pressure, releasing the flammable gases inside the battery cell 2 to the outside of the battery cell 2. This flammable gas is set at a high temperature that could potentially degrade the internal and external equipment of the battery pack 1.

[0021] The pressure relief valve 21 is disposed on the battery cell 2 such that it releases flammable gas in one direction. For example, the pressure relief valve 21 may be disposed on the battery cell 2 such that it releases flammable gas in a second direction (Y-axis direction), or it may be disposed on the battery cell 2 such that it releases flammable gas in a vertical direction, i.e., a third direction (Z-axis direction). In other words, the pressure relief valve 21 may also be disposed on the battery cell 2 such that the battery cell 2 is not located in the direction in which the flammable gas is released.

[0022] The heat-resistant material 3 is primarily formed of a heat-resistant material capable of maintaining its properties under the heat generated by the flammable gas released by the pressure relief valve 21. Furthermore, the heat-resistant material 3 can also be formed of a material with low thermal conductivity. In other words, the heat-resistant material 3 can also be formed of a heat-insulating material. Specifically, the heat-resistant material 3 can be formed of mica. However, the heat-resistant material 3 is not limited to mica; it can also be resin, metal, or ceramic.

[0023] Alternatively, the heat-resistant material 3 can also be formed of a material with heat dissipation properties, so that the temperature of the combustible gas can be reduced when the combustible gas impacts the heat-resistant material 3. In other words, the heat-resistant material 3 can also be formed of a material with high thermal conductivity.

[0024] The heat-resistant material 3 is housed together with multiple battery cells 2 within the housing 4. Specifically, the heat-resistant material 3 is disposed inside the housing 4, in the space between the battery cells 2 and the housing 4. Furthermore, the heat-resistant material 3 is disposed at least opposite to the pressure relief valve 21. In other words, the heat-resistant material 3 is disposed at least in the direction in which the pressure relief valve 21 releases flammable gas. That is, the heat-resistant material 3 may be disposed only on the surface in the second direction (Y-axis direction) or the third direction (Z-axis direction), or it may be disposed throughout the entire space within the housing 4. In addition, the heat-resistant material 3 may also be attached to the inner side of the housing 4.

[0025] The casing 4 is a container that forms at least a part of the outer shell of the battery pack 1. That is, as shown in the image. Figure 1 As shown, the casing 4 can completely cover the battery pack 1. Furthermore, the casing 4 can have a cuboid shape, but its shape is not limited to this; any shape is acceptable as long as it can accommodate multiple battery cells 2 and heat-resistant material 3. For example, the casing 4 can be formed from an aluminum plate. However, the casing 4 is not limited to aluminum; it can also be formed from resin or from a metal other than aluminum.

[0026] Next, use Figure 2 The structure of the heat-resistant material 3 and the shell 4 in Embodiment 1 will be described. Figure 2 This is a partial enlarged view of the battery pack 1 according to Embodiment 1.

[0027] First, the structure of the heat-resistant material 3 will be described. The heat-resistant material 3 has a bent-shaped gap (gas flow path) 31. The "bent shape" referred to here is also called a "labyrinth structure". This bent-shaped gap 31 extends from the area opposite the pressure relief valve 21 on one main surface of the heat-resistant material 3 on the side of the battery cell 2 to the area opposite the gap 41 of the housing 4 on the main surface of the housing 4. In other words, the bent-shaped gap 31 has a first opening (inlet) on one main surface of the heat-resistant material 3 for receiving flammable gas released from the pressure relief valve 21. A second opening (outlet) is provided on the other main surface of the heat-resistant material 3 for releasing flammable gas to the gap 41 of the housing 4. Therefore, the bent-shaped gap 31 constitutes a channel for flammable gas released from the pressure relief valve 21. Specifically, the bent-shaped gap 31 is a heat dissipation path for the flammable gas released from the pressure relief valve 21.

[0028] For example, as the combustible gas passes through the bent gap 31, it exchanges heat with the air in the path, thereby reducing the heat of the gas. Alternatively, if the heat-resistant material 3 is made of a substance with heat dissipation properties, the combustible gas can exchange heat with the heat-resistant material 3 through the wall of the bent gap 31, thereby reducing the heat of the gas.

[0029] Here, the first opening of the bent-shaped gap 31 and the pressure relief valve 21 can be arranged continuously or separately. In other words, it can be configured such that all the flammable gas released from the pressure relief valve 21 flows into the first opening, or it can be configured such that only a portion flows into the first opening. Similarly, the second opening of the bent-shaped gap 31 and the gap 41 of the housing 4 can be arranged continuously or separately.

[0030] The bent gap 31 has a distance equal to or greater than the thickness of the heat-resistant material 3, that is, in the direction in which the pressure relief valve 21 releases flammable gas, it corresponds to the thickness of the heat-resistant material 3. The bent gap 31 is formed in a bent manner inside the heat-resistant material 3. Specifically, as... Figure 2 As shown, the bend-shaped gap 31 can be formed in the shape of a crank. Alternatively, the bend-shaped gap 31 can also be formed in the shape of an S, a Z, or a wave.

[0031] For example, the bent-shaped gap 31 may have a first opening in the second direction (Y-axis direction) of the pressure relief valve 21 that releases flammable gas along the second direction (Y-axis direction). Alternatively, the bent-shaped gap 31 may also have a first opening in the third direction (Z-axis direction) of the pressure relief valve 21 that releases flammable gas along the third direction (Z-axis direction). In other words, the bent-shaped gap 31 may have a first opening at the position where the distance between it and the pressure relief valve 21 is shortest on one of the main surfaces of the heat-resistant material 3.

[0032] Similarly, the bent-shaped gap 31 can also have a second opening on the axis of the gap 41 in the housing 4. In other words, the bent-shaped gap 31 can have a second opening at the position where the distance between it and the gap 41 is shortest on another main surface of the heat-resistant material 3.

[0033] The heat-resistant material 3 can be configured with a corresponding number of bend-shaped gaps 31 according to the number of pressure relief valves 21. That is, the heat-resistant material 3 can have a combination of first openings and second openings equal to the number of pressure relief valves 21, or it can have a combination of first openings and second openings greater than the number of pressure relief valves 21. However, the bend-shaped gaps 31 are not limited to being independent of other bend-shaped gaps 31 in the heat-resistant material 3. The bend-shaped gaps 31 can be designed to merge with other bend-shaped gaps 31 in the heat-resistant material 3, or they can be designed to branch into multiple bend-shaped gaps 31.

[0034] Next, the structure of housing 4 will be described. Housing 4 has a gap 41 and a pressure regulating mechanism 42.

[0035] Gap 41 is a hole that connects the inside of the battery pack 1 casing to the outside of the casing. Specifically, gap 41 functions as an outlet for flammable gases filling the inside of the battery pack 1. Figure 2 In the example shown, the gap 41 extends from one main surface to another, and is disposed through the second direction (Y-axis direction). Furthermore, the gap 41 is at least positioned opposite the second opening in the heat-resistant material 3. In other words, the gap 41 functions as an outlet for flammable gases, which are released through the bent-shaped gap 31, to the outside of the battery pack 1.

[0036] The gap 41 can be configured such that, during the process of flammable gas being released through the gap 41 to the outside of the casing 4, some of the flammable gas impacts the periphery of the gap 41. In other words, the gap 41 can be designed to allow the flammable gas to impact its periphery and exchange heat with the casing 4, thereby reducing the temperature of the flammable gas. In this case, the gap 41 also functions as a heat dissipation path for the flammable gas during its release to the outside of the battery pack 1.

[0037] The number of gaps 41 can be the same as, but not limited to, the number of second openings in the heat-resistant material 3, and can be more than the number of second openings.

[0038] The pressure regulating mechanism 42 is used to regulate the internal pressure of the battery pack 1, typically a valve. The pressure regulating mechanism 42 is disposed on the gap 41 and closes the gap 41. When the internal pressure of the battery pack 1 reaches or exceeds the specified pressure, the pressure regulating mechanism 42 opens its closed part, thereby releasing the gas inside the battery pack 1 to the outside, thus reducing the pressure inside the battery pack 1.

[0039] Furthermore, the pressure regulating mechanism 42 can also be replaced by the gap 41. In other words, as long as the gap 41 is used, the internal pressure of the battery pack 1 can be regulated, even if the housing 4 is not equipped with a pressure regulating mechanism 42.

[0040] As described above, in the battery pack 1 according to Embodiment 1, by allowing the gas released from the pressure relief valve 21 of each battery cell 2 to be discharged to the outside of the housing 4 through the bend-shaped gap 31 provided in the heat-resistant material 3, the heat of the gas can be prevented from directly impacting the inside of the housing 4, thereby suppressing the deterioration of the housing 4 caused by the heat of the gas. Furthermore, in the battery pack 1 according to Embodiment 1, since the temperature of the gas discharged to the outside of the housing 4 can be reduced, the deterioration of the external components of the housing 4 caused by the heat of the gas can also be suppressed.

[0041] Furthermore, the high-temperature flammable gas flowing into the bent-shaped gap 31 in the heat-resistant material 3 exchanges heat with the air or heat-resistant material 3 in the path as it passes through the bent-shaped gap 31. This reduces the temperature of the flammable gas. In particular, the longer the heat dissipation path of the bent-shaped gap 31, the more significant the effect of reducing the gas temperature.

[0042] Although flammable gas is released to the outside of battery pack 1 through the bend-shaped gap 31 via the gap 41 of housing 4 and the pressure regulating mechanism 42, some gas may still remain inside housing 4. Even in this case, because the temperature of the flammable gas decreases during its passage through the bend-shaped gap 31, battery pack 1 can still suppress the degradation of housing 4 caused by the gas. In addition, battery pack 1 can also suppress the degradation of surrounding equipment caused by flammable gas released to the outside of battery pack 1 through gap 41 and pressure regulating mechanism 42.

[0043] As a specific example, it is conceivable that the wiring area of ​​the wire harness is arranged inside the battery pack 1 in a direction different from the direction in which the flammable gas is released by the pressure relief valve 21. In the battery pack 1 according to this embodiment 1, since the flammable gas discharged from each battery cell 2 flows into the bend-shaped gap 31 in the heat-resistant material 3, the possibility of high-temperature gas directly contacting the wire harness is low. Furthermore, since the temperature of the gas passing through the bend-shaped gap 31 has already decreased, the possibility of the cable harness being degraded by the gas passing through the bend-shaped gap 31 is low.

[0044] Next, the battery pack 1 according to Embodiment 2 will be described. Compared to Embodiment 1, the battery pack 1 of Embodiment 2 has a bent gap 43 in the housing 4. Embodiment 2 will be described below with reference to the accompanying drawings. It should be noted that the structure of the battery cell 2 and the heat-resistant material 3 is different from... Figure 1 and Figure 2 Since they are the same, the explanation is omitted.

[0045] Figure 3 This is a partially enlarged view of the battery pack 1 according to Embodiment 2. The housing 4 of the battery pack 1 has a bent-shaped gap 43 instead of the gap 41 in Embodiment 1. Furthermore, the battery pack 1 according to Embodiment 2, like that in Embodiment 1, has a pressure regulating mechanism 42 in the gap 43.

[0046] In Embodiment 2, the housing 4 is primarily formed of a heat-resistant material that retains its properties even under the heat generated by the flammable gas released through the bent gap 31 by the pressure relief valve 21. Alternatively, the housing 4 can also be formed of a heat-dissipating material, allowing the temperature of the gas to decrease when it impacts the housing 4. For example, the housing 4 can be formed of a material with high thermal conductivity. Specifically, the housing 4 can be formed of aluminum. However, the housing 4 is not limited to aluminum and can also be made of resin, metals other than aluminum, or ceramics. Alternatively, the housing 4 can also be formed of a material with low thermal conductivity. That is, the housing 4 can also be formed of a heat-insulating material. Other features of the housing 4 are the same as in Embodiment 1, so descriptions are omitted.

[0047] The bent-shaped gap 43 extends from the area opposite to the second opening of the bent-shaped gap 31 formed in the heat-resistant material 3 on the inner surface of the housing 4 to the outer surface of the housing 4. In other words, the bent-shaped gap 43 has a first opening on the inner surface of the housing 4 for receiving flammable gas released to one side of the housing 4 through the bent-shaped gap 31 in the heat-resistant material 3, and a second opening on the outer surface of the housing 4 for releasing the flammable gas to the outside of the battery pack 1. That is to say, the bent-shaped gap 43 is a heat dissipation path through which the flammable gas further flows after passing through the bent-shaped gap 31 in the heat-resistant material 3 and being released to the outside of the battery pack 1.

[0048] Here, the second opening of the bent-shaped gap 31 and the first opening of the bent-shaped gap 43 can be arranged continuously or with a gap between them. In other words, it can be configured such that all the combustible gas released from the second opening of the bent-shaped gap 31 flows into the first opening of the bent-shaped gap 43, or it can be configured such that a portion of the gas flows into the first opening of the bent-shaped gap 43.

[0049] The bent-shaped gap 43 has a distance equal to or greater than the thickness of the shell 4, that is, in the direction in which flammable gas is released from the bent-shaped gap 31, it corresponds to the thickness of the shell 4. The bent-shaped gap 43 is formed in a bent manner inside the shell 4. Specifically, as... Figure 3 As shown, the bend-shaped gap 43 can be formed in a crank shape. Alternatively, the bend-shaped gap 43 can also be formed in an S-shape, Z-shape, or wavy shape.

[0050] For example, the bent-shaped gap 43 may have a first opening in the second direction (Y-axis direction) of the shell 4 side opening of the bent-shaped gap 31 formed by releasing flammable gas in the second direction (Y-axis direction). Alternatively, the bent-shaped gap 43 may also have a first opening in the third direction (Z-axis direction) of the shell 4 side opening of the bent-shaped gap 31 formed by releasing flammable gas in the third direction (Z-axis direction). In other words, the bent-shaped gap 43 may have a first opening at the position where the distance between the second opening of the bent-shaped gap 31 and the inner surface of the shell 4 is shortest.

[0051] The housing 4 can have a corresponding number of bent-shaped gaps 43 based on the number of second openings in the bent-shaped gaps 31. That is, the housing 4 can have a combination of first and second openings with the same number as the second openings in the bent-shaped gaps 31, or it can have a combination of more than that number of first and second openings. However, the bent-shaped gaps 43 are not limited to being independent of other bent-shaped gaps 43 in the housing 4. The bent-shaped gaps 43 can be designed to merge with other bent-shaped gaps 43 in the housing 4, or they can be designed to branch into multiple bent-shaped gaps 43. In other words, the number of first and second openings in the bent-shaped gaps 43 is not limited to the same number as the number of pressure relief valves 21, nor is it limited to the same number of openings in the bent-shaped gaps 31.

[0052] The pressure regulating mechanism 42 is the same as in Embodiment 1, and is a mechanism for regulating the internal pressure of the battery pack 1, typically a valve. Figure 3 As shown, the pressure regulating mechanism 42 can be located at one end of the bent gap 43 near the outer side of the battery pack 1, or at one end of the bent gap 43 near the inner side of the battery pack 1. Alternatively, the pressure regulating mechanism 42 can be located at any position within the bent gap 43. Since the function of the pressure regulating mechanism 42 is the same as in Embodiment 1, its description is omitted. Furthermore, the pressure regulating mechanism 42 can also be replaced by the bent gap 43. In other words, since the pressure inside the battery pack 1 can be adjusted through the bent gap 43, it is unnecessary to provide a pressure regulating mechanism 42 in the housing 4.

[0053] In this way, according to the battery pack 1 of this embodiment 2, since the flammable gas passes not only through the bend-shaped gap 31 in the heat-resistant material 3, but also through the bend-shaped gap in the housing 4, the temperature of the flammable gas released from the pressure relief valve 21 to the outside of the battery pack 1 can be further reduced. Therefore, the battery pack 1 according to this embodiment 2 can further suppress the deterioration of the external components of the housing 4 caused by gas heat.

[0054] Next, the battery pack 1 according to Embodiment 3 will be described. The housing 4 of the battery pack 1 in Embodiment 3 is composed of an upper cover 44 and a lower housing 45. Embodiment 3 will be described below with reference to the accompanying drawings. It should be noted that for structures identical to those in Embodiments 1 and 2, descriptions will be omitted as appropriate.

[0055] Figure 4This is a schematic diagram of the battery pack 1 according to Embodiment 3. The housing 4 of Embodiment 3 includes an upper cover 44 and a lower housing 45. The upper cover 44 constitutes at least the upper part of the housing 4, and the lower housing 45 constitutes at least the lower part of the housing 4. The upper cover 44 and the lower housing 45 are provided with mating surfaces so that the housing 4 can accommodate multiple battery cells 2 and heat-resistant material 3. Here, the mating surfaces can be formed by bending the ends of the upper cover 44 and the lower housing 45 at right angles. Alternatively, the ends of the upper cover 44 and the lower housing 45 can be designed as interlocking structures to form the mating surfaces. The mating surfaces of the upper cover 44 and the lower housing 45 can be fastened, for example, by multiple bolts. The gap formed by the mating surfaces can be used as a flow path for releasing gas inside the housing 4 to the outside of the housing 4.

[0056] In embodiment 3, the heat-resistant material 3 is provided at least between the mating surfaces of the pressure relief valve 21 and the housing 4.

[0057] Figure 5 This is a partially enlarged view of the mating surface between the upper cover 44 and the lower housing 45 in the battery pack 1 according to Embodiment 3. The mating surface between the upper cover 44 and the lower housing 45, fastened by bolts or the like (not shown), is not completely fitted, but rather forms a small gap 41. This gap 41, formed at the mating surface, is the same as the gap 41 in Embodiment 1, and serves as a flow path for releasing gas from inside the housing 4 to the outside of the housing 4.

[0058] Furthermore, similar to Embodiment 1, the bent-shaped gap 31 in the heat-resistant material 3 extends from the area opposite to the pressure relief valve 21 on the main surface of the battery cell 2 side to the area opposite to the gap at the joint surface of the housing 4 on the main surface of the housing 4 side. Therefore, when flammable gas is released from the pressure relief valve 21, the gas first flows into the first opening located on the main surface of the pressure relief valve 21 within the bent-shaped gap 31, and is released through the second opening on the main surface of the housing 4 side via the bent-shaped gap 31. Then, the gas released from the second opening is released to the outside of the battery pack 1 through the gap 41 at the joint surface.

[0059] Here, the gap 41 between the second opening of the bent gap 31 and the mating surface of the housing 4 can be configured continuously or spaced apart.

[0060] In this way, the battery pack 1 according to Embodiment 3 can achieve the same effect as the battery pack 1 according to Embodiment 1 by using the gap provided on the mating surface of the upper cover 44 and the lower housing 45 as a gas flow path to release the gas inside the housing 4 to the outside of the housing 4. In addition, since the battery pack 1 according to Embodiment 3 does not require a separate gas flow path such as a dedicated gas release valve for venting on the housing 4, the cost can be reduced.

[0061] Furthermore, this utility model is not limited to the above-described embodiments, and appropriate modifications can be made as long as the purpose is not deviated from. For example, the gap 41 formed at the joint surface of the battery pack 1 involved in Embodiment 3 is not limited to the gap formed by the upper cover 44 and the lower housing 45 of the housing 4 being divided vertically, but can also be the gap formed by the left and right division of the housing 4.

Claims

1. A battery pack, characterized in that, include: The battery cell has a pressure relief valve for discharging gas generated inside the battery cell; A heat-resistant material is disposed opposite to the pressure relief valve of the battery cell; and A housing for accommodating the battery cell and the heat-resistant material, and having a gap therein, The heat-resistant material has a zigzag gas flow path that extends from a region on one main surface of the battery cell side opposite the pressure relief valve to a region on another main surface of the housing side opposite the gap in the housing.

2. The battery pack according to claim 1, characterized in that, The housing has a bent gap that extends from the area opposite the outlet of the gas flow path formed on the other main surface of the heat-resistant material in the inner surface of the housing to the outer surface of the housing.

3. The battery pack according to claim 1, characterized in that, The housing includes an upper cover and a lower housing. The gap in the housing is located at the mating surface between the upper cover and the lower housing.

4. The battery pack according to claim 1 or 2, characterized in that, The heat-resistant material has an inlet for the gas flow path at the position where the distance between it and the pressure relief valve is shortest on one of the main surfaces of the battery cell side.

5. The battery pack according to claim 1 or 2, characterized in that, The gap in the housing has a pressure regulating mechanism that opens the valve orifice when the pressure exceeds a specified limit.

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