Energy storage pack

Abstract

This power storage pack 1 comprises: at least one power storage device 2 having an exhaust part 36 that discharges a gas generated therein; a porous part 4 that has a structure in which a plurality of fire extinguishing particles 38 are aggregated and that has therein pores 40; and a case 6 that accommodates the power storage device 2 and the porous part 4. The fire extinguishing particles 38 are each an aggregate of a plurality of fire extinguishing powders, and the porous part 4 is disposed so that the gas flows through the pores 40.

Description

[Technical field]

[0001] The present disclosure relates to an electricity storage pack. [Background technology]

[0002] Power storage devices such as lithium-ion secondary batteries have been put to practical use as power sources for driving mobile electronic devices such as mobile phones, notebook computers, etc. Power storage devices are also used not only for small consumer applications but also as in-vehicle power sources, etc.

[0003] Generally, a plurality of electric storage devices are housed in a case and used in the form of an electric storage pack. In addition, generally, an electric storage device has an exhaust section that discharges high-temperature and high-pressure gas when gas is generated inside and the internal pressure increases. The gas discharged from the exhaust section includes combustible gas and fine particles such as fragments of parts that constitute the electric storage device. When combustible gas and high-temperature fine particles are discharged outside the case of the electric storage pack and the combustible gas, high-temperature fine particles, and oxygen outside the pack are all present, there is a risk of ignition. As a measure against such ignition, for example, Patent Document 1 discloses a battery module in which a fire extinguisher container containing a fire extinguishing powder is provided in an exhaust passage inside the case. In this battery module, the fire extinguisher container is broken by the heat of the gas discharged from the battery, and the fire extinguishing powder in the container is sprayed into the exhaust passage, and the fire extinguishing powder acts on the exhaust gas to suppress ignition outside the pack. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-54973 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the above-mentioned conventional structure, the extinguishing powder can be held in a predetermined position by storing the extinguishing powder in the extinguishing container. However, since the extinguishing powder is covered with the extinguishing container, the extinguishing action of the extinguishing powder may be delayed compared to when the extinguishing powder is not stored in the extinguishing container. The delay in the extinguishing action may lead to a decrease in the reliability of the electricity storage pack. In response to this, for example, it is possible to form the extinguishing powder into a sheet and place it in the case. However, if a sheet in which the extinguishing powder is densely gathered is placed in the exhaust passage, the sheet of the extinguishing powder blocks the flow of the exhaust gas, and a very large pressure loss occurs when the exhaust gas passes through the area where the extinguishing sheet is placed. If this pressure loss becomes excessive, the case of the electricity storage pack may be damaged, which may lead to a decrease in the reliability of the electricity storage pack.

[0006] The present disclosure has been made in light of these circumstances, and one of its objectives is to provide a technique for improving the reliability of an electricity storage pack. [Means for solving the problem]

[0007] One aspect of the present disclosure is an electricity storage pack. The electricity storage pack includes at least one electricity storage device having an exterior body and an exhaust part for discharging gas generated inside the exterior body, a porous part having a structure in which a plurality of extinguishing agent particles are aggregated and having voids therein, and a case for accommodating the electricity storage device and the porous part. Each extinguishing agent particle is an aggregate of a plurality of extinguishing agent powders, and the porous part is arranged so that gas flows through the voids.

[0008] Another aspect of the present disclosure is an electricity storage pack. The electricity storage pack includes at least one electricity storage device having an exterior body and an exhaust part for discharging gas generated inside the exterior body, a fire extinguishing sheet formed of an aggregate of a plurality of extinguishing powders and having a through hole, and a case for accommodating the electricity storage device and the fire extinguishing sheet. The fire extinguishing sheet is arranged so that the gas flows through the through hole.

[0009] Any combination of the above components and any conversion of the expression of the present disclosure between a method, an apparatus, a system, etc. are also valid as aspects of the present disclosure. Effect of the Invention

[0010] According to the present disclosure, the reliability of the electricity storage pack can be improved. [Brief description of the drawings]

[0011] [Figure 1] 1 is a cross-sectional view that illustrates a schematic diagram of an electricity storage pack according to a first embodiment. [Diagram 2] FIG. [Diagram 3] FIG. 11 is a cross-sectional view that illustrates a schematic diagram of an electricity storage pack according to a second embodiment. [Figure 4] FIG. 11 is a cross-sectional view that illustrates a schematic diagram of an electricity storage pack according to a third embodiment. [Diagram 5] FIG. [Figure 6] FIG. [Figure 7] FIG. 11 is a cross-sectional view that illustrates a schematic diagram of an electricity storage pack according to a fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The present disclosure will be described below with reference to the drawings based on preferred embodiments. The embodiments are illustrative and do not limit the present disclosure, and all features and combinations thereof described in the embodiments are not necessarily essential to the present disclosure. The same or equivalent components, members, and processes shown in each drawing are given the same reference numerals, and duplicated descriptions are omitted as appropriate. In addition, the scale and shape of each part shown in each drawing are set for convenience to facilitate explanation, and are not to be interpreted as being limiting unless otherwise specified. In addition, when terms such as "first" and "second" are used in this specification or claims, unless otherwise specified, these terms do not represent any order or importance, but are intended to distinguish one configuration from another. In addition, some of the members that are not important in explaining the embodiment in each drawing are omitted.

[0013] (Embodiment 1) Fig. 1 is a cross-sectional view that typically illustrates an electricity storage pack according to embodiment 1. Fig. 1 does not illustrate the internal structure of an electricity storage device 2. The electricity storage pack 1 includes a plurality of electricity storage devices 2, a porous portion 4, and a case 6.

[0014] The power storage device 2 is, for example, a rechargeable secondary battery such as a lithium ion battery, a nickel-hydrogen battery, or a nickel-cadmium battery, or a capacitor such as an electric double layer capacitor. The power storage device 2 in this embodiment is a so-called cylindrical battery. The power storage device 2 may be a prismatic battery or the like. In addition, the power storage pack 1 in this embodiment includes a plurality of power storage devices 2, but the number of power storage devices 2 is not limited, and it is sufficient that the power storage pack 1 includes at least one power storage device 2.

[0015] FIG. 2 is a cross-sectional view of the energy storage device 2. The energy storage device 2 has a known structure. As an example, the energy storage device 2 has a structure in which an electrode group 14 is housed in a bottomed cylindrical exterior body 16 together with a nonaqueous electrolyte. The electrode group 14 has a structure in which a positive electrode 8 and a negative electrode 10 are wound with a separator 12 interposed therebetween. In the exterior body 16, an insulating plate 18 and an insulating plate 20 are arranged to sandwich the electrode group 14. The energy storage device 2 also has a positive electrode lead 22, a filter 24, a negative electrode lead 26, an inner cap 28, a valve body 30, a terminal plate 32, and a gasket 34. The filter 24, the inner cap 28, the valve body 30, and the terminal plate 32 constitute a sealing body that closes the opening of the exterior body 16. The insulating plate 18 is arranged on the sealing body side, and the insulating plate 20 is arranged on the bottom side of the exterior body 16.

[0016] The positive electrode 8 is joined to the filter 24 via the positive electrode lead 22. The filter 24 is connected to an inner cap 28. The inner cap 28 has a protrusion, and is joined to a metal valve body 30 via the protrusion. The valve body 30 is connected to a terminal plate 32. The terminal plate 32 functions as a positive electrode terminal 2a. The negative electrode 10 is joined to the bottom of the exterior body 16 via a negative electrode lead 26. The bottom of the exterior body 16 functions as a negative electrode terminal 2b. A gasket 34 is interposed between the sealing body and the exterior body 16, and they are insulated from each other.

[0017] The insulating plate 18 has a through hole 18a that communicates the space on the electrode group 14 side with the space on the filter 24 side. The filter 24 has a through hole 24a that communicates the space on the insulating plate 18 side with the space on the inner cap 28 side. The inner cap 28 has a through hole 28a that communicates the space on the filter 24 side with the space on the valve body 30 side. When an abnormality such as an internal short circuit occurs in the electricity storage device 2 and gas is generated from the electrode group 14, the gas reaches the valve body 30 from the electrode group 14 through the through hole 18a, the through hole 24a, and the through hole 28a. When the pressure inside the exterior body 16 increases with the progress of gas generation, the valve body 30 expands toward the terminal plate 32. When the valve body 30 and the inner cap 28 are separated from each other due to this expansion, the current path is interrupted.

[0018] Furthermore, when the pressure inside the exterior body 16 further increases, the valve body 30 breaks. As a result, the gas inside the exterior body 16 reaches the terminal plate 32 through the through holes 18a, 24a, 28a, and the cracks in the valve body 30. The terminal plate 32 has a through hole 32a that communicates the space on the valve body 30 side with the outside of the exterior body 16. Therefore, the gas that reaches the terminal plate 32 is discharged to the outside of the exterior body 16 through the through hole 32a.

[0019] Therefore, the through hole 18a of the insulating plate 18, the through hole 24a of the filter 24, the through hole 28a of the inner cap 28, the valve body 30, and the through hole 32a of the terminal plate 32 constitute an exhaust section 36 that exhausts gas generated inside the exterior body 16. The structure of the exhaust section 36 is not limited to that described above. The exhaust section 36 may also be provided in the exterior body 16.

[0020] As shown in Fig. 1, the multiple power storage devices 2 are placed in a predetermined position inside the case 6. As an example, the positions of the multiple power storage devices 2 are determined so that the positive electrode terminals 2a and the negative electrode terminals 2b are aligned in a predetermined first direction X. The multiple power storage devices 2 are then arranged in a matrix in the first direction X and the second direction Y. The second direction Y is a direction perpendicular to the first direction X.

[0021] FIG. 1 illustrates a state in which a plurality of storage devices 2 are arranged in two columns in a first direction X and in a plurality of rows in a second direction Y. Two storage devices 2 are arranged in a first column, and three storage devices 2 are arranged in a second column. The orientation of each storage device 2 is determined such that the positive terminal 2a faces the center of the case 6 in the first direction X. The positive terminals 2a of the two storage devices 2 in the first column and the two storage devices 2 in the second column face each other. In this state, a positive electrode side current collector plate (not shown) is connected to the positive electrode terminal 2a of each storage device 2, and a negative electrode side current collector plate (not shown) is connected to the negative electrode terminal 2b of each storage device 2. As a result, each storage device 2 is electrically connected.

[0022] The porous portion 4 has a structure in which a plurality of extinguishing agent particles 38 are aggregated and stacked. Each extinguishing agent particle 38 is an aggregate of a plurality of extinguishing agent powders. The extinguishing agent powders are made of known components such as ammonium phosphate monobasic, sodium bicarbonate, potassium bicarbonate, potassium acetate, and tripotassium citrate. The extinguishing agent particles 38 are obtained, for example, by kneading the extinguishing agent powder with a binder and shaping the mixture. Alternatively, the extinguishing agent particles 38 can be obtained by compression molding of the extinguishing agent powder. The extinguishing agent particles 38 are preferably spherical, elongated, or oblate, but may be polygonal, such as a cube. The porous portion 4 has voids 40 inside. The voids 40 are spaces partitioned by the aggregated extinguishing agent particles 38.

[0023] When the extinguishing agent particles 38 are spherical, the maximum diameter is, for example, 1 mm to 10 mm. By making the maximum diameter of the extinguishing agent particles 38 1 mm or more, the dimensions of the voids 40 can be secured, and the pressure loss when the exhaust gas passes through the voids 40 can be suppressed from becoming excessive. In addition, by making the maximum diameter of the extinguishing agent particles 38 10 mm or less, the surface area of ​​the porous portion 4 (the contact area between each extinguishing agent particle 38 and the exhaust gas) can be significantly reduced, and the extinguishing action can be suppressed from being delayed or weakened. The maximum diameter is the distance between two points on the surface of the extinguishing agent particle 38 at the portion where the distance between the two points is maximum.

[0024] The case 6 is a container that houses the electricity storage device 2 and the porous portion 4. The case 6 of this embodiment has a first storage chamber 42 and a second storage chamber 44. The first storage chamber 42 and the second storage chamber 44 are separated by a wall portion 46. The first storage chamber 42 houses a plurality of electricity storage devices 2 in the above-mentioned installation manner. The second storage chamber 44 houses the porous portion 4. For example, the second storage chamber 44 is filled with a plurality of extinguishing agent particles 38 that are in a non-adhesive state. Then, the shape of the aggregate of the extinguishing agent particles 38 is held by the inner wall surface of the second storage chamber 44, thereby forming the porous portion 4. Therefore, the extinguishing agent powder is arranged in an exposed state in the case 6.

[0025] However, the present invention is not limited to this configuration, and a plurality of extinguishing agent particles 38 may be bonded together in advance to form the porous portion 4, and the porous portion 4 may be housed in the second housing chamber 44. In this case, the wall portion 46 may be omitted. When the wall portion 46 is omitted, the porous portion 4 can be fixed to the wall surface of the case 6 by adhesion or the like.

[0026] The porous portion 4 is disposed in the case 6 so that gas discharged from the electricity storage device 2 flows through the gap 40. The case 6 of the present embodiment has a through hole 48 in a wall portion 46 that separates the first storage chamber 42 and the second storage chamber 44. The internal space of the first storage chamber 42 and the internal space of the second storage chamber 44 are in communication with each other via the through hole 48. This allows gas ejected from the electricity storage device 2 to flow into the second storage chamber 44 via the through hole 48 and to flow through the gap 40 of the porous portion 4.

[0027] When gas comes into contact with the extinguishing agent particles 38 constituting the porous portion 4, the extinguishing agent powder constituting the extinguishing agent particles 38 reacts with the heat of the gas. The reactant generated by this reaction exerts a negative catalytic effect that suppresses the chain reaction of combustion. As a result, it is possible to suppress ignition caused by the gas discharged from the electricity storage device 2.

[0028] The case 6 of the present embodiment has an opening 50. The opening 50 opens at least after the gas is discharged to connect the inside and outside of the case 6. For example, the opening 50 is formed of a thin-walled portion that is provided on a part of the outer wall of the case 6 and is thinner than other parts. When the internal pressure of the case 6 increases due to the release of gas from the electricity storage device 2, the thin-walled portion tears and the opening 50 opens. When the inside and outside of the case 6 are connected by the opening 50, a gas flow path 52 is formed in the case 6 from the exhaust section 36 of the electricity storage device 2 to the opening 50.

[0029] Furthermore, a plurality of power storage devices 2 are accommodated in the first accommodation chamber 42. Thus, a plurality of gas flow paths 52 are formed in the case 6, each extending from the exhaust section 36 of each power storage device 2 to the opening 50. The plurality of gas flow paths 52 extend toward the common opening 50. Thus, each gas flow path 52 has a collection section 52a where the gas flow paths 52 are at least partially gathered together. That is, each gas flow path 52 forms a single flow path in at least a portion of the section.

[0030] In this embodiment, the second storage chamber 44 is provided so as to contact the outer wall of the case 6. Moreover, the opening 50 is arranged so as to communicate the outside of the case 6 with the internal space of the second storage chamber 44. Therefore, the internal space of the second storage chamber 44 is communicated with the internal space of the first storage chamber 42 by the through hole 48, and is communicated with the outside of the case 6 by the opening 50. As a result, the internal space of the second storage chamber 44 constitutes a part of the gas flow path 52.

[0031] The porous portion 4 is accommodated in the second storage chamber 44. Therefore, the porous portion 4 is disposed in the gas flow path 52. The gap 40 is continuous from the end of the porous portion 4 on the opening 50 side to the end on the through-hole 48 side, thereby constituting a part of the gas flow path 52. Furthermore, the gas discharged from the exhaust portion 36 of each power storage device 2 passes through the through-hole 48 and the second storage chamber 44 to reach the opening 50. Therefore, the internal space of the second storage chamber 44 constitutes the collecting portion 52a of the gas flow path 52. Therefore, the porous portion 4 in the second storage chamber 44 is disposed in the collecting portion 52a.

[0032] As described above, the opening 50 is disposed so as to communicate the internal space of the second storage chamber 44 with the outside of the case 6. Moreover, the porous portion 4 extends throughout the second storage chamber 44. Therefore, the porous portion 4 is disposed so as to cover the opening 50.

[0033] As described above, the electricity storage pack 1 according to the present embodiment includes at least one electricity storage device 2 having an exterior body 16 and an exhaust section 36 that exhausts gas generated inside the exterior body 16, a porous section 4 having a structure in which a plurality of extinguishing agent particles 38 are assembled and having voids 40 therein, and a case 6 that accommodates the electricity storage device 2 and the porous section 4. Each extinguishing agent particle 38 is an assembly of a plurality of extinguishing agent powders, and the porous section 4 is disposed in the case 6 so that gas exhausted from the electricity storage device 2 flows through the voids 40. This allows the gas exhausted from the electricity storage device 2 to come into contact with the extinguishing agent powder, and the negative catalytic action of the extinguishing agent powder can suppress ignition caused by exhaust gas.

[0034] In a structure in which a dense extinguishing agent sheet is placed in the exhaust flow path, the extinguishing agent powder sheet blocks the flow of exhaust gas, causing a large pressure loss in the flow of exhaust gas. This pressure loss may cause the internal pressure of the case to increase excessively, which may damage the case. Alternatively, the exhaust gas may bypass the extinguishing agent sheet and be discharged outside the case, which may result in insufficient extinguishing effect.

[0035] In contrast, in the present embodiment, the porous portion 4 is formed of extinguishing agent particles 38 formed by agglomerating extinguishing agent powder, and gas is circulated through the gaps 40 of the porous portion 4. This makes it possible to reduce the pressure loss when the exhaust gas is discharged to the outside of the case 6. Therefore, according to the present embodiment, damage to the case 6 can be suppressed, and a higher fire extinguishing effect can be obtained. As a result, the reliability of the electricity storage pack 1 can be improved.

[0036] In addition, in the conventional structure in which the extinguishing powder is ejected by breaking the extinguishing container, a time lag occurs between the emission of gas and the ejection of the extinguishing agent because it takes time for the container to break. As a result, there is a risk that a sufficient extinguishing effect cannot be obtained. Furthermore, the specific surface area of ​​the extinguishing powder is very large. Therefore, when the extinguishing powder is ejected, each extinguishing powder reacts with the exhaust gas suddenly. In addition, most of the extinguishing powder acts at once. On the other hand, the emission of gas from the electricity storage device 2 generally continues for several seconds to several tens of seconds. Therefore, when the extinguishing powder is ejected, the extinguishing powder runs out at the beginning of the gas emission, and there is a risk that a sufficient extinguishing effect cannot be obtained. Furthermore, when the extinguishing powder is ejected, the unreacted extinguishing powder is pushed by the exhaust gas and scattered, and there is a risk that a sufficient extinguishing effect cannot be obtained.

[0037] In contrast, in this embodiment, the extinguishant powder is disposed in the case 6 in the form of extinguishant particles 38. Therefore, a container for storing the extinguishant powder is not required. Therefore, the extinguishant powder can be applied without delay to the discharge of gas from the electricity storage device 2. In addition, the extinguishant powder reacts with the gas in order from the extinguishant powder closest to the surface of the extinguishant particles 38, so that the consumption rate of the extinguishant powder can be delayed. Therefore, the extinguishing action of the extinguishant powder can be continued for a long period of time. In addition, the extinguishant powder can be prevented from being pushed out by the exhaust gas. Therefore, according to this embodiment, a higher extinguishing effect can be obtained. Therefore, the reliability of the electricity storage pack 1 can be improved.

[0038] In addition, the porous portion 4 is an aggregate of a plurality of extinguishing agent particles 38. Therefore, by adjusting the size and number of the extinguishing agent particles 38, the size of the gaps 40 (i.e., the magnitude of pressure loss), the contact area with the exhaust gas (i.e., the amount of extinguishing agent powder acting on the exhaust gas), and the like can be flexibly adjusted. This allows for flexible response to the amount of exhaust gas and the exhaust time that may differ depending on the type of the electricity storage device 2. In addition, it is also possible to make the type of extinguishing agent powder different between the center side and the surface side of each extinguishing agent particle 38, which can improve the extinguishing effect. In addition, by forming a gas flow path with the gaps 40, a non-linear gas flow path is easily formed in the porous portion 4. This allows the gas flow path to be extended, and the gas can be further cooled before being discharged to the outside of the case 6.

[0039] Moreover, the case 6 of the present embodiment has an opening 50 that opens at least after the gas is discharged to connect the inside and outside of the case 6, and a gas flow path 52 that runs from the exhaust section 36 to the opening 50 is formed in the case 6. The porous section 4 is disposed in the gas flow path 52. This makes it easier for the gas discharged from the electricity storage device 2 to come into contact with the extinguishing agent particles 38. As a result, a higher extinguishing effect can be obtained.

[0040] The electricity storage pack 1 includes a plurality of electricity storage devices 2. Thus, a plurality of gas flow paths 52 are formed in the case 6, each extending from the exhaust section 36 of each electricity storage device 2 to the opening 50. The gas flow paths 52 have a collection section 52a where they are collected together. The porous section 4 is disposed in the collection section 52a. This allows the number of electricity storage devices 2 that are the subject of fire extinguishing by one porous section 4 to be increased. This allows the number of porous sections 4 disposed in the case 6 to be reduced. As a result, the size of the electricity storage pack 1 can be prevented from increasing. Alternatively, the number of electricity storage devices 2 that can be accommodated in the case 6 can be increased. Furthermore, the amount of extinguishing agent powder used can be reduced.

[0041] Moreover, the porous portion 4 in this embodiment is disposed so as to cover the opening 50. This makes it possible to increase the number of electricity storage devices 2 for which one porous portion 4 is responsible for extinguishing fire, even when the gas flow paths 52 extending from each electricity storage device 2 do not have the collecting portion 52a. This makes it possible to reduce the number of porous portions 4 disposed within the case 6. Also, the degree of freedom in arranging the electricity storage devices 2 can be increased.

[0042] (Embodiment 2) Except for the arrangement of the porous portion 4, the second embodiment has a common configuration with the first embodiment. The following description of the second embodiment will focus on configurations different from those of the first embodiment, and common configurations will be explained briefly or omitted. Fig. 3 is a cross-sectional view showing a schematic diagram of an electricity storage pack 1 according to the second embodiment. In Fig. 3, the internal structure of the electricity storage device 2 is not shown.

[0043] The electricity storage pack 1 includes a plurality of electricity storage devices 2, a porous portion 4, and a case 6. The plurality of electricity storage devices 2 are placed in a predetermined orientation within the case 6. In this embodiment, the plurality of electricity storage devices 2 are arranged in a matrix of 3 rows and 2 columns in a first direction X and a second direction Y. The electricity storage device 2 in the first column and the electricity storage device 2 in the second column are arranged such that their positive terminals 2a face each other. That is, the orientation of each electricity storage device 2 is determined such that the positive terminal 2a faces the center of the case 6 in the first direction X.

[0044] The case 6 has a space in the center in the first direction X, which is sandwiched between the group of power storage devices 2 in the first row and the group of power storage devices 2 in the second row. The exhaust section 36 of each power storage device 2 is connected to this space. Therefore, gas generated inside each power storage device 2 is exhausted from the exhaust section 36 to this space. This space constitutes a shared exhaust area 54 where gas is exhausted from each power storage device 2. The shared exhaust area 54 is an area defined by, for example, the surfaces on the positive terminal 2a side of the multiple power storage devices 2 and two wall surfaces of the case 6 facing each other in a direction perpendicular to the first direction X and the second direction Y.

[0045] The porous portion 4 having a structure in which a plurality of extinguishing agent particles 38 are gathered is disposed in the shared exhaust area 54. For example, a plurality of extinguishing agent particles 38 are bonded to each other in advance to form the porous portion 4, and the porous portion 4 is disposed in the shared exhaust area 54. The porous portion 4 is, for example, bonded to the wall surface of the case 6 and fixed to the shared exhaust area 54. By disposing the porous portion 4 in the shared exhaust area 54, the gas discharged from each of the power storage devices 2 can be caused to flow into the gap 40 of the porous portion 4. The arrangement of the porous portion 4 in the shared exhaust area 54 can also be regarded as the arrangement of the porous portion 4 in the gas flow path 52 of the gas discharged from each of the power storage devices 2. Note that, when viewed from the traveling direction of the gas, the entire periphery of the porous portion 4 does not have to abut against the inner wall of the case 6 that partitions the storage space of the porous portion 4.

[0046] With this configuration, it is possible to achieve the same effects as in embodiment 1. As in embodiment 1, in the present embodiment, there may be only one power storage device 2. In this case, by arranging the porous portion 4 so as to face the exhaust portion 36 of the power storage device 2, it is possible to make it easier for the gas discharged from the power storage device 2 to flow into the gaps 40 of the porous portion 4.

[0047] Above, the first and second embodiments of the present disclosure have been described in detail. The above-mentioned embodiments merely show specific examples of implementing the present disclosure. The contents of the embodiments do not limit the technical scope of the present disclosure, and many design changes such as changes, additions, and deletions of components are possible within the scope of the invention defined in the claims. A new embodiment with a design change has the effects of each of the combined embodiments and modifications. In the above-mentioned embodiments, the contents for which such design changes are possible are emphasized by adding notations such as "in this embodiment" and "in this embodiment", but design changes are permitted even in contents without such notations. In addition, any combination of components included in each embodiment is also valid as an aspect of the present disclosure. The hatching on the cross section of the drawing does not limit the material of the object to which the hatching is added.

[0048] There is no particular limitation on the number and shape of the porous portion 4 disposed in the case 6 and the openings 50 of the case 6. There is also no particular limitation on the outer shapes of the electricity storage device 2 and the case 6, the internal structure of the electricity storage device 2, etc.

[0049] (Embodiment 3) Fig. 4 is a cross-sectional view that illustrates a schematic diagram of an electricity storage pack according to embodiment 3. An internal structure of an electricity storage device 2 is not illustrated in Fig. 4. The electricity storage pack 1 includes a plurality of electricity storage devices 2, a fire extinguishing sheet 60, and a case 6.

[0050] The power storage device 2 is, for example, a rechargeable secondary battery such as a lithium ion battery, a nickel-hydrogen battery, or a nickel-cadmium battery, or a capacitor such as an electric double layer capacitor. The power storage device 2 in this embodiment is a so-called cylindrical battery. The power storage device 2 may be a prismatic battery or the like. In addition, the power storage pack 1 in this embodiment includes a plurality of power storage devices 2, but the number of power storage devices 2 is not limited, and it is sufficient that the power storage pack 1 includes at least one power storage device 2.

[0051] FIG. 5 is a cross-sectional view of the energy storage device 2. The energy storage device 2 has a known structure. As an example, the energy storage device 2 has a structure in which an electrode group 14 is housed in a bottomed cylindrical exterior body 16 together with a nonaqueous electrolyte. The electrode group 14 has a structure in which a positive electrode 8 and a negative electrode 10 are wound with a separator 12 interposed therebetween. In the exterior body 16, an insulating plate 18 and an insulating plate 20 are arranged to sandwich the electrode group 14. The energy storage device 2 also has a positive electrode lead 22, a filter 24, a negative electrode lead 26, an inner cap 28, a valve body 30, a terminal plate 32, and a gasket 34. The filter 24, the inner cap 28, the valve body 30, and the terminal plate 32 constitute a sealing body that closes the opening of the exterior body 16. The insulating plate 18 is arranged on the sealing body side, and the insulating plate 20 is arranged on the bottom side of the exterior body 16.

[0052] The positive electrode 8 is joined to the filter 24 via the positive electrode lead 22. The filter 24 is connected to an inner cap 28. The inner cap 28 has a protrusion, and is joined to a metal valve body 30 via the protrusion. The valve body 30 is connected to a terminal plate 32. The terminal plate 32 functions as a positive electrode terminal 2a. The negative electrode 10 is joined to the bottom of the exterior body 16 via a negative electrode lead 26. The bottom of the exterior body 16 functions as a negative electrode terminal 2b. A gasket 34 is interposed between the sealing body and the exterior body 16, and they are insulated from each other.

[0053] The insulating plate 18 has a through hole 18a that communicates the space on the electrode group 14 side with the space on the filter 24 side. The filter 24 has a through hole 24a that communicates the space on the insulating plate 18 side with the space on the inner cap 28 side. The inner cap 28 has a through hole 28a that communicates the space on the filter 24 side with the space on the valve body 30 side. When an abnormality such as an internal short circuit occurs in the electricity storage device 2 and gas is generated from the electrode group 14, the gas reaches the valve body 30 from the electrode group 14 through the through hole 18a, the through hole 24a, and the through hole 28a. When the pressure inside the exterior body 16 increases with the progress of gas generation, the valve body 30 expands toward the terminal plate 32. When the valve body 30 and the inner cap 28 are separated from each other due to this expansion, the current path is interrupted.

[0054] Furthermore, when the pressure inside the exterior body 16 further increases, the valve body 30 breaks. As a result, the gas inside the exterior body 16 reaches the terminal plate 32 through the through holes 18a, 24a, 28a, and the cracks in the valve body 30. The terminal plate 32 has a through hole 32a that communicates the space on the valve body 30 side with the outside of the exterior body 16. Therefore, the gas that reaches the terminal plate 32 is discharged to the outside of the exterior body 16 through the through hole 32a.

[0055] Therefore, the through hole 18a of the insulating plate 18, the through hole 24a of the filter 24, the through hole 28a of the inner cap 28, the valve body 30, and the through hole 32a of the terminal plate 32 constitute an exhaust section 36 that exhausts gas generated inside the exterior body 16. The structure of the exhaust section 36 is not limited to that described above. The exhaust section 36 may also be provided in the exterior body 16.

[0056] 4, the multiple power storage devices 2 are placed in a predetermined position inside the case 6. As an example, the multiple power storage devices 2 are oriented such that their positive electrode terminals 2a and negative electrode terminals 2b are aligned in a predetermined first direction X. The multiple power storage devices 2 are then arranged in a matrix in the first direction X and the second direction Y. The second direction Y is perpendicular to the first direction X.

[0057] FIG. 4 illustrates a state in which a plurality of storage devices 2 are arranged in two columns in the first direction X and in a plurality of rows in the second direction Y. Two storage devices 2 are arranged in the first column, and three storage devices 2 are arranged in the second column. The orientation of each storage device 2 is determined such that the positive terminal 2a faces the center of the case 6 in the first direction X. The positive terminals 2a of the two storage devices 2 in the first column and the two storage devices 2 in the second column face each other. In this state, a positive electrode side current collector plate (not shown) is connected to the positive electrode terminal 2a of each storage device 2, and a negative electrode side current collector plate (not shown) is connected to the negative electrode terminal 2b of each storage device 2. As a result, each storage device 2 is electrically connected.

[0058] The extinguishing agent sheet 60 is a plate-shaped body composed of an aggregate of a plurality of extinguishing agent powders. The extinguishing agent powders are made of known components such as monobasic ammonium phosphate, sodium bicarbonate, potassium bicarbonate, potassium acetate, and tripotassium citrate. The extinguishing agent sheet 60 can be obtained, for example, by kneading the extinguishing agent powder with a binder and shaping the mixture. Alternatively, the extinguishing agent sheet 60 can be obtained by compression molding the extinguishing agent powder.

[0059] Fig. 6 is a perspective view of the extinguishant sheet 60. As shown in Figs. 4 and 6, the extinguishant sheet 60 has through holes 62 penetrating the extinguishant sheet 60 in the thickness direction. The extinguishant sheet 60 of this embodiment is square-shaped and has a plurality of through holes 62 arranged in a matrix. Each through hole 62 is circular when viewed from the normal direction of the extinguishant sheet 60. The shapes of the extinguishant sheet 60 and the through holes 62 can be changed as appropriate.

[0060] The thickness of the extinguishant sheet 60 is, for example, 0.5 mm to 10 mm. By setting the thickness of the extinguishant sheet 60 to 0.5 mm or more, it is possible to suppress a shortage of the extinguishant powder. Furthermore, by setting the thickness of the extinguishant sheet 60 to 10 mm or less, it is possible to suppress the extinguishant powder inside the extinguishant sheet 60 from remaining unreacted and being wasted. Furthermore, the diameter of the through hole 62 is, for example, 1 mm to 3 mm. By setting the diameter of the through hole 62 to 1 mm or more, it is possible to suppress an excessive pressure loss when the exhaust gas passes through the through hole 62. Furthermore, by setting the diameter of the through hole 62 to 3 mm or less, it is possible to reduce the amount of exhaust gas that passes without sufficiently contacting the extinguishant powder. The thickness of the extinguishant sheet 60 is, for example, an average thickness. The diameter of the through hole 62 is, for example, the distance between two points on the outer periphery of the through hole 62 when viewed from the normal direction of the extinguishant sheet 60 at a portion where the distance between the two points is maximum.

[0061] The case 6 is a container that contains the electricity storage device 2 and the extinguishing agent sheet 60. The case 6 of this embodiment has a first storage chamber 42 and a second storage chamber 44. The first storage chamber 42 and the second storage chamber 44 are separated by a wall portion 46. The first storage chamber 42 contains a plurality of electricity storage devices 2 in the above-mentioned installation manner. The second storage chamber 44 contains the extinguishing agent sheet 60. Therefore, the extinguishing agent powder is placed in an exposed state inside the case 6. For example, the extinguishing agent sheet 60 has a peripheral portion fixed to the wall surface of the case 6 by adhesion or the like. Alternatively, a groove may be provided in the wall surface of the case 6, and the extinguishing agent sheet 60 may be fixed by inserting the peripheral portion of the extinguishing agent sheet 60 into the groove.

[0062] The extinguishing agent sheet 60 is disposed in the case 6 so that the gas discharged from the electricity storage device 2 flows through the through-hole 62. The case 6 of the present embodiment has a through-hole 48 in a wall portion 46 separating the first storage chamber 42 and the second storage chamber 44. The internal space of the first storage chamber 42 and the internal space of the second storage chamber 44 are communicated through the through-hole 48. As a result, the gas ejected from the electricity storage device 2 flows into the second storage chamber 44 through the through-hole 48 and can flow through the through-hole 62 of the extinguishing agent sheet 60. Even when the extinguishing agent sheet 60 is disposed so as to block the flow of the exhaust gas, the exhaust gas can flow through the through-hole 62, so that an increase in pressure loss due to the placement of the extinguishing agent sheet 60 can be suppressed.

[0063] When gas comes into contact with the extinguishing agent powder constituting the extinguishing sheet 60, the extinguishing agent powder reacts with the heat of the gas. The reactants produced by this reaction exert a negative catalytic effect that suppresses a chain reaction of combustion. As a result, it is possible to suppress ignition caused by the gas discharged from the electricity storage device 2. In addition, the extinguishing agent sheet 60 is a sheet body having a predetermined thickness. Therefore, compared with a powdered extinguishing agent, the surface area of ​​the extinguishing agent sheet 60, including the inner surface of the through hole 62 and the main surface of the extinguishing agent sheet 60, can be easily adjusted.

[0064] The case 6 of the present embodiment has an opening 50. The opening 50 opens at least after the gas is discharged to connect the inside and outside of the case 6. For example, the opening 50 is formed of a thin-walled portion that is provided on a part of the outer wall of the case 6 and is thinner than other parts. When the internal pressure of the case 6 increases due to the release of gas from the electricity storage device 2, the thin-walled portion tears and the opening 50 opens. When the inside and outside of the case 6 are connected by the opening 50, a gas flow path 52 is formed in the case 6 from the exhaust section 36 of the electricity storage device 2 to the opening 50.

[0065] Furthermore, a plurality of power storage devices 2 are accommodated in the first accommodation chamber 42. Therefore, a plurality of gas flow paths 52 are formed in the case 6, each extending from the exhaust section 36 of each power storage device 2 to the opening 50. The plurality of gas flow paths 52 extend toward the common opening 50. Therefore, each gas flow path 52 has a collection section 52a where the gas flow paths 52 are at least partially gathered together. That is, each gas flow path 52 forms a single flow path in at least a portion of the section.

[0066] In this embodiment, the second storage chamber 44 is provided so as to contact the outer wall of the case 6. Moreover, the opening 50 is arranged so as to communicate the outside of the case 6 with the internal space of the second storage chamber 44. Therefore, the internal space of the second storage chamber 44 is communicated with the internal space of the first storage chamber 42 by the through hole 48, and is communicated with the outside of the case 6 by the opening 50. As a result, the internal space of the second storage chamber 44 constitutes a part of the gas flow path 52.

[0067] The extinguishing agent sheet 60 is accommodated in the second accommodation chamber 44. Therefore, the extinguishing agent sheet 60 is arranged in the gas flow passage 52. In the second accommodation chamber 44, the extinguishing agent sheet 60 is arranged so as to block the upstream side of the gas flow passage 52 (i.e., the exhaust section 36 side) and the downstream side of the gas flow passage 52 (i.e., the opening 50 side). In other words, the extinguishing agent sheet 60 is arranged so that one main surface faces the upstream side of the gas flow passage 52 and the other main surface faces the downstream side of the gas flow passage 52, and the entire peripheral portion is fixed to the case 6 or the wall portion 46. The through hole 62 extends from one main surface of the extinguishing agent sheet 60 to the other main surface. Therefore, the exhaust gas can flow from the exhaust section 36 side to the opening 50 side through the through hole 62. Therefore, the through hole 62 constitutes a part of the gas flow passage 52.

[0068] Moreover, the gas discharged from the exhaust portion 36 of each electricity storage device 2 passes through the through-hole 48 and the second storage chamber 44 to the opening 50. Therefore, the internal space of the second storage chamber 44 forms the collection portion 52a of the gas flow path 52. Therefore, the fire extinguishing sheet 60 in the second storage chamber 44 is disposed in the collection portion 52a.

[0069] 4, the extinguishing agent sheet 60 may be disposed so as to cover the opening 50. In this case, the wall portion 46 may be omitted. When the wall portion 46 is omitted, the extinguishing agent sheet 60 may be fixed to the periphery of the opening 50 by, for example, adhesion or the like.

[0070] A plurality of extinguishing sheets 60 may be arranged at a plurality of positions in the case 6. A plurality of extinguishing sheets 60 may be arranged at a predetermined interval. In this case, adjacent extinguishing sheets 60 may have through holes 62 at different positions. By arranging the through holes 62 in this manner, the gas meanders when passing through each extinguishing sheet 60. This allows the gas flow path to be extended, and the gas can be further cooled before being discharged to the outside of the case 6. In addition, the entire periphery of the extinguishing sheet 60 does not need to be in contact with the inner wall of the second storage chamber 44 when viewed from the traveling direction of the gas flowing near the extinguishing sheet 60 (the direction perpendicular to the main surface of the extinguishing sheet 60).

[0071] As described above, the electricity storage pack 1 according to the present embodiment includes at least one electricity storage device 2 having an exterior body 16 and an exhaust section 36 that exhausts gas generated inside the exterior body 16, a fire extinguishing sheet 60 formed of an aggregate of a plurality of extinguishing powders and having through holes 62, and a case 6 that accommodates the electricity storage device 2 and the fire extinguishing sheet 60. The fire extinguishing sheet 60 is disposed so that gas exhausted from the electricity storage device 2 flows through the through holes 62. This allows the gas exhausted from the electricity storage device 2 to come into contact with the fire extinguishing powder, and the negative catalytic action of the fire extinguishing powder can suppress ignition caused by exhaust gas.

[0072] In the conventional structure in which the extinguishing powder is ejected by breaking the extinguishing container, a time lag occurs between the emission of gas and the ejection of the extinguishing agent because it takes time for the container to break. As a result, the extinguishing action of the extinguishing powder is delayed, and there is a risk that a sufficient extinguishing effect cannot be obtained. Furthermore, the specific surface area of ​​the extinguishing powder is very large. Therefore, when the extinguishing powder is ejected, each extinguishing powder reacts with the exhaust gas suddenly. In addition, most of the extinguishing powder acts at once. On the other hand, the emission of gas from the electricity storage device 2 generally continues for several seconds to several tens of seconds. Therefore, when the extinguishing powder is ejected, the extinguishing powder runs out at the beginning of the gas emission, and there is a risk that a sufficient extinguishing effect cannot be obtained. In addition, when the extinguishing powder is ejected, the unreacted extinguishing powder is pressed by the exhaust gas and scattered, and there is a risk that a sufficient extinguishing effect cannot be obtained.

[0073] In contrast, in this embodiment, the extinguishing powder is disposed in the case 6 in the form of the extinguishing sheet 60. Therefore, a container for storing the extinguishing powder is not required. Therefore, the extinguishing powder can be applied without delay to the discharge of gas from the electricity storage device 2. In addition, the extinguishing powder reacts with the gas in order from the extinguishing powder closest to the surface of the extinguishing sheet 60, so that the consumption rate of the extinguishing powder can be delayed. Therefore, the extinguishing action of the extinguishing powder can be continued for a long time. In addition, the extinguishing powder can be prevented from being pushed out by the exhaust gas. Therefore, according to this embodiment, a higher extinguishing effect can be obtained. Therefore, the reliability of the electricity storage pack 1 can be improved.

[0074] In addition, if a dense extinguishing agent sheet without through holes 62 is placed in the exhaust flow path, the extinguishing agent sheet blocks the flow of exhaust gas, causing a large pressure loss in the flow of exhaust gas. In this case, the internal pressure of the case may increase excessively due to the pressure loss, which may damage the case. Alternatively, the exhaust gas may bypass the extinguishing agent sheet without through holes and be discharged outside the case, which may result in insufficient extinguishing effect.

[0075] In contrast, in the present embodiment, the extinguishing sheet 60 is formed of extinguishing powder, and gas is passed through the through holes 62 of the extinguishing sheet 60. This reduces the pressure loss when the exhaust gas is discharged to the outside of the case 6. Therefore, according to the present embodiment, damage to the case 6 can be suppressed, and a higher fire extinguishing effect can be obtained. This increases the reliability of the electricity storage pack 1.

[0076] In addition, by adjusting the thickness of the extinguishing sheet 60 and the diameter, number and arrangement of the through holes 62, it is possible to flexibly adjust the magnitude of pressure loss when the exhaust gas passes through the extinguishing sheet 60, the contact area with the exhaust gas (i.e., the amount of extinguishing powder acting on the exhaust gas), etc. This makes it possible to flexibly respond to the amount of exhaust gas and the exhaust time that may differ depending on the type of the electricity storage device 2. It is also possible to use different types of extinguishing powder on the inner side and the surface side of the extinguishing sheet 60, which can improve the fire extinguishing effect.

[0077] Moreover, the case 6 of this embodiment has an opening 50 that opens at least after the gas is discharged to connect the inside and outside of the case 6, and a gas flow path 52 that runs from the exhaust section 36 to the opening 50 is formed inside the case 6. The fire extinguishing sheet 60 is then disposed in the gas flow path 52. This makes it easier for the gas discharged from the electricity storage device 2 to come into contact with the fire extinguishing sheet 60. As a result, a higher fire extinguishing effect can be obtained.

[0078] The electricity storage pack 1 includes a plurality of electricity storage devices 2. Therefore, a plurality of gas flow paths 52 are formed in the case 6, each extending from the exhaust section 36 of each electricity storage device 2 to the opening 50. The gas flow paths 52 have a collection section 52a where they are collected together. The extinguishing agent sheet 60 is disposed in the collection section 52a. This allows the number of electricity storage devices 2 to be extinguished by one extinguishing agent sheet 60 to be increased. This allows the number of extinguishing agent sheets 60 disposed in the case 6 to be reduced. As a result, the size of the electricity storage pack 1 can be prevented from increasing. Alternatively, the number of electricity storage devices 2 that can be accommodated in the case 6 can be increased. Also, the amount of extinguishing agent powder used can be reduced.

[0079] Furthermore, when the extinguishing sheet 60 is arranged to cover the opening 50, even if the gas flow paths 52 extending from each of the electricity storage devices 2 do not have the collecting portion 52a, the number of electricity storage devices 2 for which one extinguishing sheet 60 is responsible for extinguishing fire can be increased. This makes it possible to reduce the number of extinguishing sheets 60 arranged in the case 6. Furthermore, the freedom of arrangement of the electricity storage devices 2 can be increased.

[0080] (Embodiment 4) Except for the arrangement of the extinguishing agent sheet 60, the fourth embodiment has a common configuration with the third embodiment. The following description of the fourth embodiment will focus on the configuration different from the third embodiment, and the common configuration will be explained briefly or omitted. Fig. 7 is a cross-sectional view showing a schematic diagram of an electricity storage pack 1 according to the fourth embodiment. In Fig. 7, the internal structure of the electricity storage device 2 is not shown.

[0081] The electricity storage pack 1 includes a plurality of electricity storage devices 2, a fire extinguishing agent sheet 60, and a case 6. The plurality of electricity storage devices 2 are placed in a predetermined orientation within the case 6. In this embodiment, the plurality of electricity storage devices 2 are arranged in a matrix of 3 rows and 2 columns in a first direction X and a second direction Y. The electricity storage device 2 in the first column and the electricity storage device 2 in the second column are arranged such that their positive terminals 2a face each other. That is, the orientation of each electricity storage device 2 is determined such that the positive terminal 2a faces the center of the case 6 in the first direction X.

[0082] The case 6 has a space in the center in the first direction X, which is sandwiched between the group of power storage devices 2 in the first row and the group of power storage devices 2 in the second row. The exhaust section 36 of each power storage device 2 is connected to this space. Therefore, gas generated inside each power storage device 2 is exhausted from the exhaust section 36 to this space. This space constitutes a shared exhaust area 54 where gas is exhausted from each power storage device 2. The shared exhaust area 54 is an area defined by, for example, the surfaces on the positive terminal 2a side of the multiple power storage devices 2 and two wall surfaces of the case 6 facing each other in a direction perpendicular to the first direction X and the second direction Y.

[0083] The extinguishing agent sheet 60, which is composed of an aggregate of a plurality of extinguishing agent powders, is disposed in the shared exhaust area 54. For example, the extinguishing agent sheet 60 is disposed so that one main surface faces the group of the first row of the power storage devices 2 and the other main surface faces the group of the second row of the power storage devices 2. The extinguishing agent sheet 60 is, for example, adhered to the wall surface of the case 6 and fixed to the shared exhaust area 54. By disposing the extinguishing agent sheet 60 in the shared exhaust area 54, the gas discharged from each of the power storage devices 2 can be made to flow through the through holes 62 of the extinguishing agent sheet 60. The disposition of the extinguishing agent sheet 60 in the shared exhaust area 54 can also be regarded as the disposition of the extinguishing agent sheet 60 in the gas flow path 52 of the gas discharged from each of the power storage devices 2.

[0084] With this configuration, it is possible to achieve the same effect as in embodiment 3. As in embodiment 3, in this embodiment, there may be only one electricity storage device 2. In this case, by arranging the fire extinguishing sheet 60 so as to face the exhaust part 36 of the electricity storage device 2, it is possible to make it easier for the gas discharged from the electricity storage device 2 to flow into the through holes 62 of the fire extinguishing sheet 60.

[0085] The above has described the third and fourth embodiments of the present disclosure in detail. The above-mentioned embodiments merely show specific examples of implementing the present disclosure. The contents of the embodiments do not limit the technical scope of the present disclosure, and many design changes such as changes, additions, and deletions of components are possible within the scope of the invention as defined in the claims. A new embodiment with a design change has the effects of each of the combined embodiments and modifications. In the above-mentioned embodiments, the contents for which such design changes are possible are emphasized by adding notations such as "in this embodiment" and "in this embodiment", but design changes are permitted even in contents without such notations. In addition, any combination of components included in each embodiment is also valid as an aspect of the present disclosure. The hatching on the cross section of the drawing does not limit the material of the object to which the hatching is added.

[0086] There is no particular limitation on the number and shape of the fire extinguishing sheet 60 disposed in the case 6 or the openings 50 in the case 6. There is also no particular limitation on the outer shapes of the electricity storage device 2 and the case 6, the internal structure of the electricity storage device 2, etc. [Industrial Applicability]

[0087] The present disclosure can be used in electricity storage packs. [Explanation of symbols]

[0088] 1 storage pack, 2 storage device, 4 porous portion, 6 case, 16 exterior body, 36 exhaust portion, 38 extinguishing agent particles, 40 gap, 50 opening, 52 gas flow path, 52a collection portion, 54 shared exhaust area, 60 extinguishing agent sheet, 62 through hole.

Claims

1. At least one electricity storage device having an exterior body and an exhaust part that exhausts gas generated inside the exterior body; A porous portion having a structure in which a plurality of extinguishing agent particles are assembled and having voids between the extinguishing agent particles; a case that accommodates the electricity storage device and the porous portion, Each extinguishing agent particle is a compact of a plurality of extinguishing agent powders, The extinguishing powder comprises at least one of ammonium phosphate monobasic, sodium bicarbonate, potassium bicarbonate, potassium acetate, and tripotassium citrate; The porous portion is arranged so that the gas flows through the gap. Power storage pack.

2. the case has an opening that opens at least after the gas is discharged to connect the inside and the outside of the case, and a gas flow path that runs from the exhaust part to the opening is formed in the case, The porous portion is disposed in the gas flow path. The electricity storage pack according to claim 1 .

3. The electricity storage pack includes a plurality of the electricity storage devices, a plurality of gas flow paths extending from the exhaust portion of each of the power storage devices to the opening are formed in the case, The gas flow paths have a collecting portion where they are collected together, The porous portion is disposed in the collection portion. The electricity storage pack according to claim 2 .

4. The porous portion is disposed so as to cover the opening. The electricity storage pack according to claim 2 or 3.

5. The electricity storage pack includes a plurality of the electricity storage devices, the case has a shared exhaust area to which the exhaust sections of the power storage devices are connected, The porous portion is disposed in the shared exhaust region. The electricity storage pack according to claim 1 .

6. At least one electricity storage device having an exterior body and an exhaust part that exhausts gas generated inside the exterior body; A fire extinguishing sheet which is a molded body of a plurality of fire extinguishing powders and has through holes; a case that accommodates the power storage device and the fire extinguishing sheet, The extinguishing powder comprises at least one of ammonium phosphate monobasic, sodium bicarbonate, potassium bicarbonate, potassium acetate, and tripotassium citrate; The extinguishing agent sheet is arranged so that the gas flows through the through hole. Power storage pack.

7. the case has an opening that opens at least after the gas is discharged to connect the inside and the outside of the case, and a gas flow path that runs from the exhaust part to the opening is formed in the case, The extinguishing sheet is disposed in the gas flow path. The electricity storage pack according to claim 6 .

8. The electricity storage pack includes a plurality of the electricity storage devices, a plurality of gas flow paths extending from the exhaust portion of each of the power storage devices to the opening are formed in the case, The gas flow paths have a collecting portion where they are collected together, The extinguishing agent sheet is disposed at the collection portion. The electricity storage pack according to claim 7.

9. The extinguishing agent sheet is arranged to cover the opening. The electricity storage pack according to claim 7 or 8.

10. The electricity storage pack includes a plurality of the electricity storage devices, the case has a shared exhaust area to which the exhaust sections of the power storage devices are connected, The extinguishing agent sheet is disposed in the shared exhaust area. The electricity storage pack according to claim 6 .

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