JP7172076B2 - power storage device - Google Patents

Description

The present invention relates to a power storage device.

Patent Literature 1 discloses a power storage device that includes a flow path for balancing pressures inside and outside an exterior body. The flow path is formed with a vent that communicates with the interior of the exterior body and a communication port that communicates with the exterior of the exterior body, and a breathable waterproof membrane (membrane member) is disposed in the vent.

JP 2017-152162 A

In the power storage device of Patent Literature 1, there is a possibility that the air-permeable waterproof membrane may be detached due to an increase in pressure inside the exterior body, but no consideration is given to the unintended movement of the detached air-permeable waterproof membrane within the flow path.

An object of the present invention is to provide a power storage device capable of suppressing unintended movement of a detached film member.

One aspect of the present invention includes a power storage element, an exterior body that houses the power storage element, a first communication port formed in the exterior body and communicating with the inside of the exterior body, and a a second communication port that communicates with the first communication port, and a flow path in which a membrane member that allows air to pass through is arranged in the first communication port, the flow channel having one end side where the first communication port is formed. a first communicating portion of, a second communicating portion on the other end side where the second communicating port is formed, and a maximum portion of the cross-sectional shape formed between the first communicating portion and the second communicating portion and a narrowed portion whose dimension is smaller than the dimension of the minimum portion of the outer shape of the film member.

According to this power storage device, since the channel is provided with the narrowed portion that is smaller than the dimension of the membrane member, even if the membrane member is detached due to an increase in pressure in the exterior body, the electric current is directed toward the second communication portion by the narrowed portion. Unintended movement of the membrane member can be suppressed. Therefore, it is possible to prevent the detached film member from blocking part of the second communication port and the opening portion of the narrowed portion on the side of the first communication portion. As a result, it is possible to effectively suppress the film member from becoming a resistance to the exhaust from the first communication port toward the second communication port.

The exterior body includes a main body with one end open and a lid closing the opening of the main body, and the flow path is formed in the lid and has a recess with one end open and the recess in the recess. It is composed of a cover that closes the opening. According to this aspect, it is possible to reliably form the recess (flow path) having the throttle portion smaller than the membrane member in the lid, and the lid having the recess can be reliably manufactured by the molding die.

An external terminal protruding outward and a through hole communicating with the main body for connecting the external terminal and the storage element are provided on one surface of the lid body in which the recess is formed, The through-hole is provided in the concave portion so as to be adjacent to the first communicating portion and the constricted portion, and is closed by the cover. According to this aspect, a part of the outer peripheral wall that defines the through-hole also serves as one wall that defines the throttle portion and one wall that defines the first communication portion. can be reduced, and the configuration of the lid can be simplified. Moreover, since the through-hole can be closed by the cover that closes the concave portion, the number of parts of the power storage device can be reduced, and the size of the cover can be reduced.

The bottom of the second communicating portion is located below the bottom of the first communicating portion. According to this aspect, dust or liquid that enters from the outside through the second communication port collides with the wall of the second communication portion and stays at the bottom of the second communication portion. As a result, it is possible to prevent dust or liquid from entering the first communicating portion, thereby preventing clogging of the film member with dust or liquid.

The flow path is provided with an exhaust portion closer to the second communication port than the narrowed portion, and the exhaust portion includes an exhaust port that communicates with the inside of the main body, and is arranged at the exhaust port so that the inside of the main body is defined. an exhaust valve capable of relieving the pressure in the body when the pressure is higher than the initial pressure. According to this aspect, it is possible to effectively suppress the detachment of the membrane member due to the pressure increase in the main body. Moreover, when the recess has a through hole, the exhaust part is adjacent to the through hole. In this case, a part of the outer peripheral wall that defines the through hole also serves as one wall that defines the exhaust section, so the number of walls required for the lid can be reduced, and the configuration of the lid can be simplified.

In the power storage device of the present invention, even if the film member is separated from the first communication port, the constricted portion can suppress unintended movement of the film member from the first communication portion toward the second communication portion. Therefore, it is possible to effectively suppress the film member from becoming a resistance to the exhaust from the first communication port toward the second communication port.

1 is an exploded perspective view showing a power storage device according to a first embodiment of the present invention; FIG. FIG. 2 is a perspective view showing part of a power storage device; FIG. 3 is a plan view showing a portion of FIG. 2; FIG. 4 is a cross-sectional view along the line BB of FIG. 3 with the cover attached; FIG. 4 is a cross-sectional view taken along the line AA of FIG. 3 with the cover attached; FIG. 4 is a cross-sectional view taken along the line CC of FIG. 3 with the cover attached; FIG. 4B is a partially enlarged cross-sectional view of FIG. 4A; FIG. 4C is a partially enlarged sectional view of FIG. 4C; The perspective view which shows some electrical storage apparatuses which concern on 2nd Embodiment.

Embodiments of the present invention will be described below with reference to the drawings.

(First embodiment)
FIG. 1 shows a power storage device 10 according to a first embodiment of the invention. The power storage device 10 includes a plurality of (eight in this embodiment) battery cells (power storage elements) 12 and busbar units 24 arranged on the battery cells 12, which are housed inside the exterior body 30. Configuration. The outer body 30 has a channel 45 for balancing internal and external pressures. In this embodiment, the film member 75 arranged in the flow path 45 and functioning as a filter effectively suppresses unintended obstruction of exhaust.

In the following description, the lateral direction of the battery cells 12, which is the direction in which the battery cells 12 are arranged, may be referred to as the X direction. Also, the longitudinal direction of the battery cell 12 may be referred to as the Y direction, and the height direction of the battery cell 12 may be referred to as the Z direction. The power storage device 10 of this embodiment is a rectangular parallelepiped whose X-direction dimension is longer than its Y-direction dimension.

(Overview of power storage device)
As shown in FIG. 1 , the battery cells 12 are arranged in the X direction and accommodated in the exterior body 30 . Insulation between adjacent battery cells 12 is performed by an insulating member arranged on the outer periphery of each battery cell 12 .

A nonaqueous electrolyte secondary battery such as a lithium ion battery is used as the battery cell 12 . However, various battery cells 12 including capacitors can be applied other than the lithium ion battery. Each battery cell 12 is provided with a metal container 13, and the container 13 accommodates an electrode body in which positive and negative electrode sheets are laminated with a separator interposed therebetween, current collectors of the positive and negative electrodes, and an electrolytic solution. It is

The container 13 is rectangular and has a pair of long sides 14 extending along the YZ plane and a pair of short sides 15 extending along the XZ plane. The dimension of the short side 15 in the X direction is shorter than the dimension of the long side 14 in the Y direction. The container 13 also has a bottom surface 16 and a terminal surface (lid) 17 extending along the XY plane. On the terminal surface 17 located on the upper side in the Z direction, a positive terminal 18 is arranged on one end side in the Y direction, and a negative terminal 19 is arranged on the other end side in the Y direction. A gas discharge valve 20 as a safety valve is provided on the terminal surface 17 so as to be positioned between the terminals 18 and 19 .

End plates 22 made of metal plates thinner than the battery cells 12 and having the same shape as the long side surfaces 14 are arranged at both ends of the battery cell 12 group in the X direction. The end plates 22 abut against the long side surfaces 14 of the battery cells 12 and the end walls 34 of the exterior body 30 .

The busbar unit 24 includes a busbar frame 25 to which a plurality of busbars (not shown) are attached, and is arranged on the side of the terminals 18 and 19 of the battery cell group 12 (upper side in the Z direction). The plurality of busbars are electrically connected to the positive terminal 18 and the negative terminal 19 of a predetermined battery cell 12 , respectively, and constitute a power supply circuit that supplies power to the plurality of battery cells 12 . The busbar frame 25 functions as an inner lid that partitions the interior of the exterior body 30 . Reference numeral 26 in FIG. 1 denotes a cover that covers a plurality of busbars.

The exterior body 30 is made of resin, and includes a main body 32 with one open surface (upper surface in the Z direction) and a lid 37 closing the opening of the main body 32 . The main body 32 and the lid 37 are fixed airtight and liquid-tight by welding or the like.

The main body 32 has a rectangular parallelepiped shape whose X-direction dimension is longer than its Y-direction dimension, and includes a rectangular bottom wall 33 . A pair of end walls 34 located outside in the arrangement direction of the battery cells 12 are erected at both ends of the bottom wall 33 in the X direction. On both sides of the bottom wall 33 in the Y direction, a pair of side walls 35 positioned outside in the direction intersecting with the arrangement direction of the battery cells 12 are erected.

The lid 37 is provided with a positive external terminal 38 on one end in the X direction and a negative external terminal 39 on the other end in the X direction. These external terminals 38 and 39 protrude upward in the Z direction from the lid 37 and are electrically connected to bus bars 40 (see FIG. 4C). Busbar 40 is connected to busbar 27 arranged in busbar unit 24 by bolt 41 and nut 42 . This bus bar 27 is different from the bus bar that connects to the terminals 18 and 19 of the battery cell 12 . The battery cell 12 group can be electrically charged and discharged via the busbar unit 24 and the external terminals 38 and 39 .

Here, in the battery cell 12, an unintended increase in internal pressure may cause the gas discharge valve 20 to open or the container 13 to break, thereby releasing internal vent gas. Even if one battery cell 12 among the plurality of battery cells 12 releases the vent gas, the remaining battery cells 12 often maintain the voltage without releasing the vent gas. Since the released vent gas increases the pressure inside the exterior body 30 , it is necessary to exhaust it to the outside of the exterior body 30 . Therefore, the exterior body 30 is provided with a channel 45 that communicates the inside and the outside. However, since the vent gas may harm the human body, the flow path 45 is connected to the exhaust flow path of the vehicle (transportation equipment). For example, a hose is used for the exhaust passage of the vehicle, one end of the hose is connected to the power storage device 10, and the other end of the hose is open outside the vehicle.

(Overview of flow path)
As shown in FIGS. 1 and 2 , the flow path 45 is composed of a recess 46 formed in the lid 37 and a cover 53 closing the opening 47 of the recess 46 . The concave portion 46 is formed in a protruding portion 37a that protrudes upward in the Z direction in the lid body 37, is recessed toward the battery cell 12 (downward in the Z direction), and has a saucer shape with an opening 47 on the upper side in the Z direction (one end). is. 4A to 4C, the recess 46 includes a partition wall 48 facing the opening 47 and an outer peripheral wall 49 erected on the outer circumference of the partition wall 48. As shown in FIG. The partition wall 48 and the outer peripheral wall 49 partition the interior and exterior of the exterior body 30 .

As shown in FIGS. 2 and 3 , the flow path 45 includes a ventilation portion (first communication portion) 57 , a communication portion (second communication portion) 61 , an exhaust portion 65 and a throttle portion 73 . In this embodiment, a joint portion 80 is provided adjacent to the flow path 45 and this joint portion 80 is also closed by the same cover 53 . The flow path 45 communicates with the ventilation portion 57, the throttle portion 73, the exhaust portion 65, and the communication portion 61 in this order from one end side to the other end side in the Y direction (from the bottom side to the top side in FIG. 3). This layout is designed as follows.

Specifically, the ventilation part 57 is formed in a rectangular shape extending in a first direction indicated by an arrow in the Y direction. The narrowed portion 73 is formed in a rectangular shape that is continuous with the tip of the ventilation portion 57 in the first direction and protrudes in the second direction indicated by the arrow in the X direction so as to intersect the first direction. there is The exhaust portion 65 is formed in a rectangular shape that is continuous with the tip of the narrowed portion 73 in the second direction and protrudes in the first direction and the second direction. The communication portion 61 is formed in a rectangular shape that is continuous with the tip of the exhaust portion 65 in the first direction and protrudes in the first direction.

The joints 80 are provided at the corners so as to be adjacent to the ventilation section 57 , the throttle section 73 and the exhaust section 65 . In other words, the joint portion 80 is adjacent to the ventilation portion 57 in the second direction, and adjacent to the throttle portion 73 and the exhaust portion 65 in the direction opposite to the first direction. The cover 53 has a plate shape having the same shape as the overall shape of the flow path 45 including the joint 80 .

A concave groove 50 is formed around the concave portion 46 , and a convex piece 54 is formed on the outer circumference of the cover 53 . By arranging the cover 53 in the opening 47 of the recess 46 , the projection piece 54 is inserted into the recess 50 , and by fixing them with a fixing means such as an adhesive, the cover 53 is airtight and liquid-tight with respect to the recess 46 . tightly fixed.

As shown in FIGS. 3 and 4A, the ventilation part 57 is formed at one end of the flow path 45 . A ventilation port (first communication port) 58 communicating with the inside of the exterior body 30 (on the battery cell 12 side) is formed in the center of the partition wall 48a that is the bottom of the ventilation portion 57 . That is, the vent 58 is formed on one end side of the flow path 45 . The one end side is not the end in the strict sense, but also includes a configuration positioned at a distance from the end. A film member 75 that allows air to pass is arranged in the vent 58 . The film member 75 will be detailed later.

As shown in FIGS. 3 and 4B, the communicating portion 61 is formed at the other end of the flow path 45 . A partition wall 48 b that is the bottom of the communicating portion 61 is located below the partition wall 48 a of the ventilation portion 57 . The partition wall 48a of the ventilation part 57 and the partition wall 48c of the exhaust part 65 are formed on the same plane, and the partition wall 48b of the communication part 61 and the partition wall 48c of the exhaust part 65 are connected by the continuous wall 51.

The communicating portion 61 is surrounded by a side wall 49 b that forms part of the outer peripheral wall 49 . A communication port (second communication port) 62 that communicates with the outside of the exterior body 30 is formed in the side wall 49b that separates the communication portion 61 from the atmosphere side. That is, the communication port 62 is formed on the other end side of the flow path 45 . The other end side is not the end in the strict sense, but also includes a configuration that is spaced apart from the end. A plurality of communication ports 62 are provided in a grid pattern, and the communication port 62 positioned on the opening 47 side is formed at the same height as the partition walls 48a and 48c.

Referring also to FIG. 4A, the side wall 49b in which the communication port 62 is formed is provided with a pipe 63 that protrudes outward (atmosphere side) and is connected to a hose of the vehicle. The pipe 63 is formed with an inner diameter capable of surrounding all the communication ports 62 . In other words, the communication port 62 is formed inside the inner peripheral surface of the pipe 63 .

As shown in FIGS. 3 and 4C, the exhaust portion 65 is formed in an intermediate portion of the flow path 45 that is biased toward the communicating portion 61 side. An exhaust port 66 communicating with the inside of the exterior body 30 (on the battery cell 12 side) is formed in the center of the partition wall 48c. The exhaust port 66 has a circular tubular portion 67 protruding toward the opening 47 , and an exhaust valve 70 is arranged in the tubular portion 67 .

The exhaust valve 70 releases the pressure to the outside of the exterior body 30 through the flow path 45 when the pressure inside the exterior body 30 becomes higher than a predetermined pressure. Referring to FIG. 6, a notch 68 is formed on the opening 47 side of the tubular portion 67 . The exhaust valve 70 is an elastically deformable rubber cap with one end open and the other end closed. When the pressure inside the exterior body 30 increases, the outer peripheral portion 71 of the exhaust valve 70 is pushed radially outward through the cutout portion 68 by the air pressure, and elastically deforms. As a result, the pressure inside the exterior body 30 is released into the flow path 45 (outside the exterior body 30 ) through the space between the outer peripheral portion 71 and the cylindrical portion 67 .

As shown in FIGS. 3, 4A, and 4B, the narrowed portion 73 is formed in an intermediate portion of the flow path 45 that is biased toward the ventilation portion 57 side. That is, the narrowed portion 73 is formed between the ventilation portion 57 and the communication portion 61 via the exhaust portion 65 . A partition wall 48 d that is the bottom of the narrowed portion 73 is formed on the same plane as the partition walls 48 a and 48 c of the ventilation portion 57 and the exhaust portion 65 .

(Details of diaphragm and membrane member)
As shown in FIGS. 3 and 4A, the flow area (W×T) of the constricted portion 73 is smaller than the flow area of the ventilation portion 57 . Specifically, the gas or liquid flows in the X direction in the narrowed portion 73, and the flow area perpendicular to the flow direction is the width W1 of the narrowed portion 73 in the Y direction and the height T1 of the narrowed portion 73 in the Z direction. Defined. Gas or liquid mainly flows in the Y direction in the ventilation part 57, and the flow area perpendicular to the flow direction is defined by the width W2 of the ventilation part 57 in the X direction and the height T2 of the ventilation part 57 in the Z direction. be done. The heights T1 and T2 of the ventilation portion 57 and the narrowed portion 73 are the same, and the width W2 of the ventilation portion 57 is larger than the width W1 of the narrowed portion 73 .

The narrowed portion 73 has a rectangular shape with a width W1 smaller than the height T1, and the dimension of this minimum portion (width W) is smaller than the dimension of the minimum portion of the outer shape of the film member 75 . The maximum portion of the narrowed portion 73 is the diagonal portion from the lower end of one of the pair of partition walls 48 d facing each other in the Y direction to the upper end of the other. smaller than the dimensions. Naturally, the dimensions of the maximum portions of the outer shapes of the film member 75 and the constricted portion 73 are larger than the dimensions of the respective minimum portions. Therefore, the dimension of the maximum portion of the film member 75 is greater than the dimension of the minimum portion of the film member 75, and the dimension of the minimum portion of the film member 75 is greater than the dimension of the maximum portion of the throttle portion 73. A relationship is established that the dimension of the maximum portion is larger than the dimension of the minimum portion of the constricted portion 73 .

The film member 75 of this embodiment has a circular shape in plan view, and the maximum dimension of the outer shape of the film member 75 in plan view when viewed from the Z direction is equal to the minimum dimension. Its diameter D (eg, 10 mm) is larger than the width W1 (eg, 3 mm), which is the dimension of the minimum portion of the constricted portion 73, the height T1, and the diagonal dimension, which is the dimension of the maximum portion. That is, the dimension of the maximum portion of the film member 75 is equal to the dimension of the minimum portion of the film member 75, the dimension of the minimum portion of the film member 75 is larger than the dimension of the maximum portion of the constricted portion 73, and the dimension of the maximum portion of the constricted portion 73 is The relationship is that the dimension is larger than the dimension of the minimum portion of the constricted portion 73 . Therefore, when the film member 75 is detached from the vent hole 58, the film member 75 interferes with the partition wall 48, the outer peripheral wall 49, and the cover 53 that define the opening of the narrowed portion 73, and does not pass through the narrowed portion 73. is blocked.

Referring to FIG. 5, the film member 75 is formed by fixing a base material 77 to an air-permeable waterproof film 76 capable of allowing the passage of air and blocking the passage of water. The membrane member 75 has a larger diameter than the vent hole 58 and is attached around the vent hole 58 on the base material 77 side. The ventilation part 57 is provided with an annular rib 59 so as to surround the membrane member 75 and prevent interference with the membrane member 75 .

The air-permeable waterproof membrane 76 is made of PTFE (fluororesin) and has a mesh size finer than the size of water or water droplets (for example, 100 to 3000 μm or more). The mesh size is preferably several tens of μm or less, more preferably 0.1 to 10 μm. However, instead of the air-permeable waterproof film 76, a dust collection filter through which water or water droplets can pass may be used.

The base material 77 is made of nonwoven fabric, and its mesh size is larger than that of the air-permeable waterproof membrane 76 . The base material 77 is more difficult to deform elastically than the air-permeable waterproof membrane 76, and has a strength that does not bend even if it receives pressure from the inside of the exterior body 30 in a state where it interferes with the opening part of the narrowed part 73. have Bent means a state of being folded in two, and an elastically curved state is included in the state of not being bent in the present invention.

As described above, the flow path 45 of this embodiment is composed of the recess 46 formed in the lid 37 and the cover 53 closing the opening 47 of the recess 46 . Therefore, the recess 46 having the narrowed portion 73 smaller in size than the film member 75 can be reliably formed in the lid 37, and the lid 37 having the recess 46 can be reliably manufactured by a molding die. In other words, the narrowed portion 73 becomes more difficult to remove from the die if the overall length thereof is increased.

In this power storage device 10 , when the internal pressure of the exterior body 30 becomes higher than the atmospheric pressure due to the release of the vent gas, the pressure is released to the outside of the exterior body 30 through the membrane member 75 , the flow path 45 and the pipe 63 . However, the waterproof film member 75 allows a smaller amount of gas per unit time to pass than a non-waterproof filter. Therefore, if the pressure release through the membrane member 75 is insufficient, the pressure inside the exterior body 30 is released to the outside of the exterior body 30 through the exhaust valve 70 , the flow path 45 and the pipe 63 . As a result, detachment of the film member 75 due to the pressure inside the exterior body 30 can be suppressed.

However, if the internal pressure of the exterior body 30 suddenly increases, the film member 75 may be separated from the air vent 58 and part of the communication port 62 may be covered with the film member 75 . In this case, the film member 75 acts as resistance to the exhaust from the vent 58 toward the communication port 62, and the amount of exhaust from the pipe 63 is reduced.

However, in the power storage device 10 of the present embodiment, the channel 45 is provided with the narrowed portion 73 that is smaller in size than the film member 75 . Therefore, even if the membrane member 75 is detached due to an increase in pressure inside the exterior body 30 , unintended movement of the membrane member 75 toward the communication section 61 can be suppressed by the throttle portion 73 . Therefore, it is possible to prevent the detached film member 75 from blocking not only a part of the communication port 62 connected to the outside of the exterior body 30 but also the opening portion of the narrowed portion 73 on the ventilation portion 57 side. As a result, the film member 75 acts as a resistance to the exhaust from the vent 58 toward the communication port 62 , and the decrease in the amount of exhaust from the pipe 63 can be effectively suppressed.

On the other hand, when the pressure inside the exterior body 30 becomes lower than the atmospheric pressure, the air outside the exterior body 30 flows into the interior of the exterior body 30 through the pipe 63, the flow path 45, and the membrane member 75. are balanced. At this time, if dust or liquid enters the flow path 45 together with the outside air, the film member 75 may be clogged with the dust or liquid.

However, in the power storage device 10 of the present embodiment, the bottom of the communicating portion 61 (the partition 48b) is arranged below the bottom of the ventilation portion 57 (the partition 48a). Therefore, dust or liquid that has entered from the outside through the communication port 62 collides with the side wall 49 b facing the communication port 62 and stays in the partition wall 48 b located below the ventilation section 57 . Therefore, it is possible to prevent dust or liquid from entering the ventilation section 57 , thereby preventing clogging of the film member 75 with dust or liquid.

Also, if water enters the exterior body 30 together with the outside air, there is a possibility that the terminals 18 and 19 and the metal container 13 of the battery cell 12 that maintains voltage without being damaged will be short-circuited. In this case, there is a possibility that a safety problem may occur due to the reaction between the moisture and the electrodes 18 and 19, a safety problem due to the outflow of the electrolytic solution, a corrosion problem of peripheral parts, and the like. However, in the channel 45 of the present embodiment, a step is formed between the communication portion 61 and the ventilation portion 57 , and the membrane member 75 using the ventilation waterproof membrane 76 is arranged in the ventilation port 58 . Therefore, even if water enters the flow path 45, it is possible to prevent the water from entering the exterior body 30 through the air vent 58, thereby effectively suppressing the problems caused by the water entering.

(Outline of joint)
As shown in FIGS. 3 and 4C , the joint portion 80 has a rectangular through-hole 81 that communicates with the exterior body 30 and is provided for electrically connecting the positive electrode external terminal 38 to the battery cell 12 . there is Specifically, with the lid 37 welded to the main body 32 , the busbars 40 arranged on the lid 37 and the busbars 27 of the busbar unit 24 are connected by the nuts 42 through the joints 80 . A joint for electrically connecting the negative electrode external terminal 39 and the battery cell 12 is provided on the opposite side of the joint 80 in the X direction.

As described above, the joint portion 80 is provided adjacent to the ventilation portion 57 , the throttle portion 73 and the exhaust portion 65 . The ventilation part 57 is defined by a side wall 49 a forming part of the outer peripheral wall 49 , the throttle part 73 is defined by a side wall 49 d forming part of the outer peripheral wall 49 , and the exhaust part 65 is defined by a part of the outer peripheral wall 49 . It is partitioned by a side wall 49c forming a part. The joint portion 80 and the ventilation portion 57 are partitioned by the side wall 49 a of the ventilation portion 57 . The joint portion 80 , the constricted portion 73 and the exhaust portion 65 are partitioned by side walls 49 c and 49 d of the constricted portion 73 and the exhaust portion 65 . Other sides of the joint 80 are partitioned by partition walls 82a and 82b. A recessed groove 83 continuous with the recessed groove 50 is formed in the partition walls 82a and 82b. A projecting piece 55 corresponding to the recessed groove 83 is formed on the cover 53 .

In this manner, the joint portion 80 having the through hole 81 is formed in the lid body 37 so as to be adjacent to the ventilation portion 57 and the constricted portion 73 . Therefore, part of the side walls 49 a , 49 c , 49 d that partition the vent section 57 , the exhaust section 65 , and the throttle section 73 also serve as walls that define the joint section 80 . As a result, since the number of walls required for the lid 37 can be reduced, the configuration of the lid 37 can be simplified. Moreover, since the through-hole 81 can be closed by the cover 53 that closes the concave portion 46 , the number of components of the power storage device 10 can be reduced, and the size of the cover 53 can be reduced.

(Second embodiment)
FIG. 7 shows the power storage device 10 of the second embodiment. In this second embodiment, the concave portion 46 of the flow path 45 is formed in a rectangular shape as a whole, and the ventilation portion 57 and the exhaust portion 65 are partitioned by the partition plate 85a, and the throttle portion 73 is formed. Different from the form.

Specifically, the recessed portion 46 is provided with a ventilation portion 57, an exhaust portion 65, and a communication portion 61 adjacent to each other in this order from one end side to the other end side. Partition plates 85 a and 85 b protruding from the partition wall 48 toward the opening 47 are provided between the ventilation portion 57 and the exhaust portion 65 and between the exhaust portion 65 and the communication portion 61 . Further, the communicating portion 61 is provided with partition plates 86 a to 86 c projecting from the partition wall 48 toward the opening 47 .

The partition plate 85a extends from the side wall 49a forming the outer peripheral wall 49 toward the side wall 49b. The gap between the partition plate 85 a and the side wall 49 b constitutes the narrowed portion 73 and is larger than the gap between the partition plate 85 a and the side wall 49 a and smaller than the diameter of the film member 75 . The partition plate 85b extends from the side wall 49b toward the side wall 49a. The gap between the partition plate 85b and the side wall 49a is larger than the gap between the partition plate 85b and the side wall 49b.

The partition plates 86a to 86c constitute a labyrinth structure, extend in parallel along the side walls 49a and 49b, and are provided in order from the side wall 49a toward the side wall 49b. The gap between the partition plates 86a, 86c and the side wall 49c is larger than the gap between the partition plates 86a, 86c and the partition plate 85b. The gap between the partition plate 86b and the partition plate 85b is larger than the gap between the partition plate 86b and the side wall 49c.

A ventilation port 58 is provided in the ventilation portion 57, and the ventilation port 58 is closed by a film member 75 similar to that of the first embodiment. An exhaust port 66 is provided in the exhaust portion 65 , and the exhaust port 66 is closed by an exhaust valve 87 . The exhaust valve 87 includes a valve body 88 covering the exhaust port 66 and a fixing portion 89 for fixing to the partition wall 48 .

In the second embodiment thus configured, since the narrowed portion 73 smaller than the film member 75 is provided between the ventilation portion 57 and the exhaust portion 65 (communication portion 61), the same function as in the first embodiment is provided. and effects can be obtained.

Note that the power storage device 10 of the present invention is not limited to the configuration of the above embodiment, and various modifications are possible.

For example, two or more narrowed portions 83 may be provided between the ventilation portion 57 and the communication portion 61 . Further, the flow path 45 may not be provided with the exhaust section 65 . The step between the partition wall 48a of the communicating portion 61 and the partition wall 48b of the ventilation portion 57 may be stepped, or may be gently displaced by an inclined wall.

The battery cell 12 that constitutes the storage element may be of a winding type in which a belt-shaped electrode sheet and a separator are wound, or may be of a lamination type in which a plurality of rectangular electrode sheets and separators are laminated. good. Moreover, the battery cell 12 is not limited to a prismatic battery in which an electrode body is housed in a container 13, and may be a laminate type battery in which a laminated electrode body is sealed with a laminate film.

The power storage device 10 of the present invention can be used for starting a gasoline vehicle or a diesel vehicle equipped with only an internal combustion engine, and a hybrid vehicle equipped with an internal combustion engine and an electric motor. Moreover, the power storage device 10 of the present invention can also be used for driving a hybrid vehicle and an electric vehicle equipped with only an electric motor.

10 power storage device 12 battery cell (power storage element)
DESCRIPTION OF SYMBOLS 13... Container 14... Long side surface 15... Bottom surface 17... Terminal surface 18... Positive electrode terminal 19... Negative electrode terminal 20... Gas discharge valve 22... End plate 24... Bus bar unit 25... Bus bar frame 26... Cover 27... Bus bar 30 Exterior body 32 Main body 33 Bottom wall 34 End wall 35 Side wall 37 Lid 37a Protrusion 38 Positive electrode external terminal 39 Negative electrode external terminal 40 Bus bar 41 Bolt 42 Nut 45 Flow path 46 Recessed portion 47 Opening 48, 48a to 48d Partition wall 49 Peripheral wall 49a to 49d Side wall 50 Groove 51 Continuous wall 53 Cover 54 Protruding piece 55 Protruding piece 57 Ventilation part (first communication part)
58 Vent (first communication port)
59... Rib 61... Communicating portion (second communicating portion)
62...Communication port (second communication port)
DESCRIPTION OF SYMBOLS 63... Pipe 65... Exhaust part 66... Exhaust port 67... Cylindrical part 68... Notch part 70... Exhaust valve 71... Outer peripheral part 73... Constriction part 75... Membrane member 76... Breathable waterproof membrane 77... Base material 80... Joint part 81... Through-hole 82a, 82b Partition wall 83 Groove 85a, 85b Partition plate 86a to 86c Partition plate 87 Exhaust valve 88 Valve body 89 Fixed part

Claims (4)

a storage element;
an exterior body housing the power storage element;
The exterior body includes a first communication port that communicates with the inside of the exterior body, and a second communication port that communicates with the exterior of the exterior body, and allows air to pass through the first communication port. and a flow path in which a membrane member is arranged,
The flow path is
a first communication portion adjacent to the first communication port and formed on the second communication port side;
a second communication portion adjacent to the second communication port and formed on the first communication port side;
a constricted portion formed between the first communicating portion and the second communicating portion, the size of the largest portion of the cross-sectional shape being smaller than the size of the smallest portion of the outer shape of the membrane member;
an exhaust portion arranged closer to the second communication port than the throttle portion,
The exhaust part is disposed in an exhaust port communicating with the inside of the exterior body, and in the exhaust port, and reduces the pressure inside the exterior body when the pressure inside the exterior body becomes higher than a predetermined pressure. an openable exhaust valve;
storage device. The exterior body includes a main body with one end opened and a lid covering the opening of the main body,
The flow path is
a recess formed in the lid and having one end open;
The power storage device according to claim 1, further comprising: a cover that closes the opening of the recess. a storage element;
an exterior body housing the power storage element;
The exterior body includes a first communication port that communicates with the inside of the exterior body, and a second communication port that communicates with the exterior of the exterior body, and allows air to pass through the first communication port. and a flow path in which a membrane member is arranged,
The flow path is
a first communicating portion on one end side in which the first communicating port is formed;
a second communicating portion on the other end side in which the second communicating port is formed;
a constricted portion formed between the first communicating portion and the second communicating portion, the size of the largest portion of the cross-sectional shape being smaller than the size of the smallest portion of the outer shape of the membrane member;
The exterior body includes a main body with one end opened and a lid covering the opening of the main body,
The flow path is
a recess formed in the lid and having one end open;
and a cover that closes the opening of the recess,
An external terminal protruding outward and a through hole communicating with the main body for connecting the external terminal and the power storage element are provided on one surface of the lid body in which the recess is formed,
The power storage device, wherein the through-hole is provided in the concave portion so as to be adjacent to the first communicating portion and the constricted portion, and is closed by the cover. a storage element;
an exterior body housing the power storage element;
The exterior body includes a first communication port that communicates with the inside of the exterior body, and a second communication port that communicates with the exterior of the exterior body, and allows air to pass through the first communication port. and a flow path in which a membrane member is arranged,
The flow path is
a first communicating portion on one end side in which the first communicating port is formed;
a second communicating portion on the other end side in which the second communicating port is formed;
a constricted portion formed between the first communicating portion and the second communicating portion, the size of the largest portion of the cross-sectional shape being smaller than the size of the smallest portion of the outer shape of the membrane member;
The power storage device, wherein the bottom of the second communicating portion is positioned below the bottom of the first communicating portion.

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