JP7259713B2 - Valve device and assembled battery - Google Patents

Description

The present invention relates to a valve device and an assembled battery.

Japanese Patent Laying-Open No. 2004-6213 (Patent Document 1) discloses a battery pack including a safety valve. In this battery pack, when the internal power generation element generates gas and the internal pressure rises, the gas is released from the safety valve. Therefore, according to this battery pack, even if the internal pressure rises due to the gas generated by the power generation element, the internal pressure can be reduced (see Patent Document 1).

JP-A-2004-6213

In the battery pack disclosed in Patent Document 1, a safety valve (valve device) is formed on a sealing plate that seals the open end of the battery can. Therefore, when the pressure inside the battery pack rises and the valve device operates, there is a high possibility that the gas released from the valve device hits the side of the battery pack. When the gas released from the valve device hits the side surface of the battery pack, the deterioration of the outer layer of the container housing the battery progresses. Furthermore, deterioration extends to all peripheral members and equipment.

SUMMARY OF THE INVENTION The present invention has been made to solve such problems, and it is an object of the present invention to provide a valve device and an assembled battery in which the deterioration of the outer layer of the container is less likely to be accelerated even when the valve device operates. is.

A valve device according to one aspect of the present invention is attached to a first container that contains a battery. The valve device includes an attachment portion, a valve device main body, and a gas passage portion. The attachment portion is configured to be attached to the first container. The valve device main body is configured to reduce the pressure when the pressure inside the first containing body rises due to the gas generated inside the first containing body. The gas passage portion is provided between the mounting portion and the valve device main body, and is configured to allow the gas that has passed through the mounting portion to pass into the valve device main body. When the valve device is attached to the first container, the valve device main body is positioned outside the outer circumference of the first container.

When this valve device is attached to the first container, the valve device main body is located outside the outer circumference of the first container. That is, when this valve device is attached to the first containing body, even if the valve device is actuated, the gas is released at a position away from the first containing body. Therefore, according to this valve device, the gas discharged from the valve device main body is less likely to hit the outer layer of the first housing body, so deterioration of the outer layer of the first housing body can be suppressed.

In the above valve device, the gas passage portion may have a length of 10 mm or more.

In the above valve device, the gas passage portion may have flexibility in the length direction.

In the valve device described above, the gas passage portion may be configured to retain a desiccant therein.

Water vapor may enter the first container through minute gaps in the valve device main body. According to this valve device, since the desiccant is held inside the gas passage portion, even if water vapor enters the main body of the valve device, the influence of water vapor infiltration can be reduced in the gas passage portion.

In the valve device described above, when the assembled battery is configured by housing the plurality of first containers in the second container, the valve device main body may be positioned outside the outer circumference of the second container. .

When this valve device is attached to the first housing body and the first housing body is housed in the second housing body, the valve device main body is located outside the outer circumference of the second housing body. That is, even if the valve device is actuated in this case, the gas is released at a position remote from the second containing body. Therefore, according to this valve device, since the gas is discharged to the outside of the second container, it is possible to prevent the gas from filling the second container and deteriorating the outer layer of the first container.

In the above valve device, the secondary side of the valve device measured in accordance with the method specified in JIS Z2331: 2006 “Helium leak test method” “Vacuum spray method (spray method)” in an environment of 25 ° C. to the primary side may be 5.0×10 ⁻¹¹ Pa·m ³ /sec or more and 5.0×10 ⁻⁶ Pa·m ³ /sec or less.

If the sealing performance of the valve device is too high, even if the pressure in the first housing increases, the valve device may not function and the pressure in the first housing may not decrease. On the other hand, if the sealing performance of the valve device is too low, water vapor can easily enter the first container through minute gaps in the main body of the valve device. The present inventors (and others) have found that when the helium leak amount of the valve device satisfies the above conditions, the gas generated in the first container can be released to the outside and the intrusion of water vapor into the first container can be prevented to a high degree. I have found that it can be suppressed. Therefore, according to this valve device, since the amount of helium leaked from the valve device satisfies the above conditions, the gas generated in the first container can be released to the outside, and water vapor can enter the first container. can be highly suppressed.

A valve device according to another aspect of the present invention is attached to an assembled battery comprising a plurality of housing bodies each containing a battery. The valve device includes a plurality of mounting portions, a valve device main body, and a plurality of gas passage portions. Each of the plurality of mounting portions is configured to be attached to each of the plurality of containers. The valve device main body is configured to reduce the pressure when the pressure inside the containing body rises due to the gas generated inside at least one of the plurality of containing bodies. Each of the plurality of gas passage portions extends from each of the plurality of mounting portions and is configured to allow gas that has passed through the mounting portion to pass through to the valve device main body. When the valve device is attached to the assembled battery, the valve device main body is positioned outside the outer circumference of each of the plurality of containers.

When this valve device is attached to the assembled battery, the valve device main body is located outside the outer circumference of each of the plurality of containers. That is, when this valve device is attached to the assembled battery, even if the valve device operates, the gas is released at a position distant from the container. Therefore, according to this valve device, since the gas discharged from the valve device main body is less likely to hit the outer layer of the container, deterioration of the outer layer of the container can be suppressed.

Further, in this valve device, only one valve device main body is provided for the plurality of gas passage portions. Therefore, according to this valve device, the number of valve device main bodies is reduced compared to the case where one valve device main body is provided in each gas passage section, so the cost of the valve device in the assembled battery can be suppressed. can be done.

Further, in this valve device, only one valve device main body is provided for a plurality of containers. Therefore, according to this valve device, compared to the case where each of the plurality of containers is provided with a valve device main body, the possibility of water vapor entering the container through minute gaps in the valve device main body is reduced. be able to.

An assembled battery according to another aspect of the present invention includes a plurality of containers and the valve device described above. Each of the plurality of containers contains a battery.

A valve device according to another aspect of the present invention is attached to an assembled battery comprising a plurality of housing bodies each containing a battery. The valve device includes a plurality of mounting portions and a valve device main body. Each of the plurality of mounting portions is configured to be attached to each of the plurality of containers. The valve device main body communicates with the plurality of mounting portions, and is configured to reduce the pressure when the pressure inside the container rises due to the gas generated inside at least one of the plurality of containers. It is

In this valve device, only one valve device main body is provided for a plurality of mounting portions. Therefore, according to this valve device, the number of valve device main bodies is reduced compared to the case where one valve device main body is provided for each attachment portion, so the cost of the valve device in the assembled battery is suppressed. be able to.

Further, in this valve device, only one valve device main body is provided for a plurality of containers. Therefore, according to this valve device, compared to the case where a valve device main body is provided for each of the plurality of containers, the possibility of water vapor entering the container through minute gaps in the valve device main body is reduced. can be reduced.

Advantageous Effects of Invention According to the present invention, it is possible to provide a valve device and an assembled battery in which deterioration of the outer layer of the container is less likely to be accelerated even when the valve device operates.

1 is a plan view of a battery cell; FIG. It is a side view of a battery cell. 1 is a plan view of a valve device; FIG. FIG. 4 is a sectional view along IV-IV in FIG. 3; FIG. 3 is a side view of the battery module with a part of the exterior seen through; FIG. 10 is a side view of the battery module according to Embodiment 2, with a part of the exterior seen through; 1 is a top view of a valve device; FIG. FIG. 8 is a cross-sectional view taken along line VIII-VIII of FIG. 7;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The same or corresponding parts in the drawings are denoted by the same reference numerals, and the description thereof will not be repeated.

[1. Embodiment 1]
<1-1. Overview>
FIG. 1 is a plan view of battery cell 10 including valve device 100 according to the first embodiment. FIG. 2 is a side view of the battery cell 10. FIG. In addition, in FIG. 2, part of the configuration (electrode tab 30) is omitted in order to facilitate understanding of the position of the valve device 100. As shown in FIG. This also applies to FIGS. 5 and 6. FIG.

As shown in FIGS. 1 and 2, the battery cell 10 includes a container 20, a battery element 15, electrode tabs 30A and 30B, and a valve device 100. As shown in FIG.

The container 20 is composed of a laminated body (laminate film) having, for example, a substrate layer, a barrier layer and a heat-sealable resin layer in this order. A molding type having a storage space capable of accommodating the element 15 may be used. For example, the housing body 20 is composed of two laminated films, one of which is a molded article having a housing recess for housing the battery element 15, and the other of which is not provided with a housing recess. As a kind of cover material, the peripheral edges (sealed portion 22) of the laminate films are heat-sealed in a state in which the two sheets are superimposed. The housing body 20 is configured to house the battery element 15 inside while sandwiching the electrode tabs 30A and 30B and the valve device 100 at the periphery. For the container 20 composed of a laminated body (laminate film), two molded products each having a recess for storage are prepared, and in a state in which these two molded products are superimposed, the peripheral edges of the laminated films are separated from each other. It may be in the form of a so-called double cup in which the (sealed portion 22) is heat-sealed and the storage volume is approximately doubled. It does not have to be a container and may consist of a can, for example.

Battery element 15 is, for example, a storage member such as a lithium ion battery or a capacitor. If the battery element 15 malfunctions, gas may be generated inside the container 20 . Further, for example, when battery element 15 is a capacitor, gas may be generated in container 100 due to a chemical reaction in the capacitor.

Electrode tabs 30 ( 30 A, 30 B) are metal terminals used for power input/output in battery element 15 . One end of each electrode tab 30 is electrically connected to the electrode (positive electrode or negative electrode) of the battery element 15 , and the other end protrudes outward from the edge of the container 20 .

A metal material forming the electrode tab 30 is, for example, aluminum, nickel, copper, or the like. For example, when the battery element 15 is a lithium ion battery, the electrode tab 30 connected to the positive electrode is usually made of aluminum or the like, and the electrode tab 30 connected to the negative electrode is usually made of copper, nickel or the like. be. In addition, in the battery cell 10, the electrode tabs 30A and 30B are arranged on the same side, but the arrangement of the electrode tabs 30A and 30B is not limited to this. For example, each of electrode tabs 30A and 30B may be arranged on opposite sides of battery cell 10 .

The valve device 100 communicates with the inside of the container 20, and when the pressure inside the container 20 becomes equal to or higher than a predetermined value due to the gas generated inside the container 20, the gas inside the container 20 is released. is configured to release to the outside. In addition, in the battery cell 10, the valve device 100 is arranged between the electrode tabs 30A and 30B, but the arrangement of the valve device 100 is not limited to this. For example, valve device 100 may be placed on a side on which none of electrode tabs 30A, 30B are provided.

If the gas released from the valve device 100 continuously hits the outer layer of the container 20, the deterioration of the outer layer of the container 20 progresses. In the battery cell 10 , the tip of the valve device 100 (valve device main body 110 (described later)) is positioned outside the outer periphery of the container 20 . That is, even if the valve device 100 is actuated, the gas is released at a position away from the containing body 20 . Therefore, according to the valve device 100, since the discharged gas is less likely to hit the containing body 20, deterioration of the outer layer of the containing body 20 can be suppressed. The valve device 100 will be described in detail below.

<1-2. Configuration of valve device>
FIG. 3 is a plan view of the valve device 100. FIG. As shown in FIG. 3, the valve device 100 includes a valve device main body 110, a gas passage portion 120, and a mounting portion . The valve device main body 110, the gas passage portion 120, and the mounting portion 130 may be configured integrally, or may be configured separately. For example, if each part is configured separately, it is possible to select different materials for each part.

The valve device main body 110 is made of, for example, metal, resin, or the like. It includes a structure that lowers the internal pressure when it rises. Details of the valve device main body 110 will be described later.

The attachment portion 130 is made of, for example, metal, resin, or the like, and is configured to be attached to the container 20 . More specifically, the attachment portion 130 is configured to be fixed to the container 20 by having at least a portion of the attachment portion 130 sandwiched between the containers 20 . In a state where the valve device 100 is attached to the housing body 20, in the mounting portion 130, the outer peripheral surface of the mounting portion 130 and the heat-fusible resin layer, which is the innermost layer of the housing body 20, are fused and joined. are doing. For example, when the attachment portion 130 is made of metal, an adhesive member that adheres to both the metal and the resin is arranged between the heat-sealable resin layer of the container 20 and the attachment portion 130 . may The mounting portion 130 has an R (for example, R=0.2 mm to 2.0 mm) formed at the corner of the end opposite to the gas passage portion 120 . In addition, the R does not necessarily have to be formed. In the specification of the present application, rounded corners are expressed as "R is formed". Here, "R is formed" means a state in which the corners are rounded, structurally similar to chamfering. Used to mean the radius of the corner roundness. If the mounting portion 130 is made of metal, it is also possible to chamfer the sharp corners generated in the manufacturing process of the mounting portion 130 of the valve device 100 to round the corners (to form an R). However, if the mounting portion 130 is a resin molded product, it is also possible to form the radius without chamfering such as cutting by molding so as to have rounded corners from the beginning.

Gas passage portion 120 is configured by, for example, a metal pipe, a resin pipe, or the like. The gas passage portion 120 is provided between the attachment portion 130 and the valve device main body 110 and is configured to allow the gas that has passed through the attachment portion 130 to pass into the valve device main body 110 . The longitudinal length of gas passage portion 120 is, for example, 10 mm or more. By securing the length of the gas passage portion 120 in the longitudinal direction, the position of the valve device main body 110 is outside the outer circumference of the container 20 when the valve device 100 is attached to the container 20 .

FIG. 4 is a sectional view taken along line IV-IV of FIG. As shown in FIG. 4, the end portion of the mounting portion 130 opposite to the gas passage portion 120 is formed with an R (for example, R=0.2 mm to 2.0 mm). In addition, the R does not necessarily have to be formed. Further, inside the gas passage portion 120 and the mounting portion 130, an air passage A1 is formed. Ventilation path A<b>1 , for example, guides gas generated in container 20 to valve device main body 110 .

Inside the valve device main body 110, a valve mechanism configured to discharge gas generated in the container 20 when the valve device 100 is attached to the container 20 is provided. Specifically, the valve device body 110 includes a valve seat 112 , a ball 114 , a spring 116 and a membrane 118 . That is, the valve device main body 110 is provided with a ball spring type valve mechanism (check valve). The valve mechanism provided in the valve device main body 110 is not particularly limited as long as it can reduce the pressure inside the containing body 20 that has risen due to gas. It may be a valve mechanism such as a mold.

Valve seat 112 is configured by an O-ring, for example. The O-ring is a hollow circular ring made of, for example, fluororubber. Each of ball 114 and spring 116 is made of, for example, stainless steel. Note that the ball 114 may be made of resin.

Membrane 118 is composed of, for example, a PTFE (PolyTetraFluoroEthylene) membrane that has a pore diameter of 10 ^-2 μm to 10 ⁰ μm, does not leak electrolyte, and allows only gas to permeate (selectively permeate). . Since the PTFE membrane is a soft material, if the strength is insufficient, the membrane 118 may be formed by integrally molding a mesh or non-woven fabric of polypropylene or polyester and the PTFE membrane to be reinforced.

When the pressure inside the container 20 reaches a predetermined pressure while the valve device 100 is attached to the container 20, the gas guided from the air passage A1 presses the ball 114 toward the air opening O1. When the ball 114 is pressed and the spring 116 is compressed, the gas in the container 20 passes through the gap formed between the ball 114 and the valve seat 112, permeates the membrane 118, and exits the container 20 through the vent O1. is discharged to the outside of the

In the valve device 100, the diameter of the valve device main body 110 is longer than the diameters of the gas passage portion 120 and the mounting portion 130, but the relationship between the diameters of the respective portions is not limited to this. For example, the valve device main body 110, the gas passage portion 120, and the attachment portion 130 may have the same diameter.

<1-3. Helium leak amount>
As described above, the valve device 100 releases the gas inside the container 20 to the outside when the pressure inside the container 20 becomes equal to or higher than a predetermined value due to the gas generated inside the container 20. is configured to If the sealing performance of the valve device 100 is higher than necessary, there is a possibility that the valve device 100 will not function even if the pressure inside the container 20 exceeds a predetermined value. On the other hand, if the sealing performance of the valve device 100 is unnecessarily low, water vapor (moisture) may enter the container 20 from the external environment during normal times (when the pressure inside the container 20 is less than a predetermined value). highly sexual.

In the valve device 100 according to the present embodiment, by adjusting the amount of helium leaked from the valve device 100, both the high sealing performance of the valve device 100 and the high degree of suppression of the entry of water vapor into the container 20 are achieved. are doing.

The present inventors (and others) have developed a valve device 100 that is measured in a 25° C. environment in accordance with the method specified in JIS Z2331:2006 "Helium leak test method" and "Vacuum spray method (spray method)". The helium leak amount from the secondary side to the primary side of the valve device 100 is 5.0×10 ⁻¹¹ Pa·m ³ /sec or more and 5.0×10 ⁻⁶ Pa·m ³ /sec or less. It has been found that both the high degree of sealing performance of the container 20 and the high degree of suppression of the intrusion of water vapor into the container 20 can be achieved. Therefore, the helium leak amount of the valve device 100 is 5.0×10 ⁻¹¹ Pa·m ³ /sec or more and 5.0×10 ⁻⁶ when measured by the method specified in the above standard in a 25° C. environment. Pa·m ³ /sec or less. The secondary side of the valve device 100 indicates the outside of the container 20 when the valve device 100 is attached to the container 20 . Further, the primary side of the valve device 100 indicates the inner side of the container 20 when the valve device 100 is attached to the container 20 .

In the valve device 100, the upper limit of the helium leak amount is preferably about 4.5×10 ⁻⁶ Pa·m ³ /sec or less, more preferably about 1.0×10 ⁻⁶ Pa·m ³ /sec or less, More preferably about 1.0×10 ⁻⁷ Pa·m ³ /sec or less, more preferably about 1.0×10 ⁻⁸ Pa·m ³ /sec or less, and the lower limit is 5.0×10 ⁻¹¹ Pa·m ³ /sec or more, and a preferable range is about 5.0×10 ⁻¹¹ Pa·m ³ /sec to 4.5×10 ⁻⁶ Pa·m ³ /sec, 5.0×10 ⁻¹¹ Pa·m ³ /sec to 1.0×10 ⁻⁶ Pa·m ³ /sec, 5.0×10 ⁻¹¹ Pa·m ³ /sec to 1.0×10 ⁻⁷ Pa·m ³ /sec about 5.0×10 ⁻¹¹ Pa·m ³ /sec to 1.0×10 ⁻⁸ Pa·m ³ /sec.

When the helium leak amount satisfies the above upper limit, it is possible to highly suppress the intrusion of water vapor (moisture) from the external environment into the container 20 . Further, when the helium leak amount satisfies the above lower limit, gas can be released to the outside when gas is generated in the container 20 . If the helium leak amount is too small, it is difficult to stably release the gas generated inside the container 20 to the outside of the container 20 . Moreover, if the battery cell continues to be used without such a valve device being opened for a long period of time, there is a high possibility that the valve device will not be opened appropriately even when the internal pressure rises to the design value.

Furthermore, in the valve device 100, the helium leak amount is in the range of about 5.0×10 ⁻¹¹ Pa·m ³ /sec to 2.0×10 ⁻¹⁰ Pa·m ³ /sec, further 5.0×10 ⁻ If it is set in the range of about ¹¹ Pa·m ³ /sec to 1.5 × 10 ^-10 Pa·m ³ /sec, the intrusion of water vapor (moisture) from the external environment into the container 20 is prevented at a particularly high degree. can be suppressed. In order to set such a helium leak amount, as described later, we designed the shape of the part where the valve seat and the ball of the valve mechanism contact with extremely high precision, which is not done with conventional check valves.・It is necessary to process.

The helium leak test is performed in the following manner. That is, in the helium leak test, in accordance with the method specified in JIS Z2331:2006 "Helium leak test method", "Vacuum spray method (spray method)", from the secondary side of the valve device 100 to the primary side of helium leak is measured. Specifically, a helium leak detector is used as the test device. Also, the gas valve (valve device main body 110) of the valve device 100 is installed in a leak test jig (a jig for confirming that there is no helium leak when a dummy valve device with a gas valve blocked is inserted). and install it into the helium leak detector through the test port. Confirm that there is no helium leak between the jig and the helium leak detector. Thereafter, the primary side of the valve device 100 is evacuated to 13 Pa, 99.99% helium gas is sprayed from the secondary side of the valve device 100, and measurement is started. Spray for 1-2 seconds, wait for 2-4 seconds and record the results of the evaluation. As a precaution, the same valve device 100 was covered with a hood having a volume of 50 ml in accordance with the method specified in the "vacuum envelope method (vacuum hood method)" of JIS Z2331:2006 "helium leak test method". You may wait 20 seconds to confirm that the measurement results are the same. The environmental temperature for measurement is 25°C in all cases.

In the valve device 100, the differential pressure between the primary side and the secondary side (that is, the opening pressure of the valve device 100) has a lower limit of preferably about 0.05 MPa or more, more preferably about 0.1 MPa or more. , The upper limit is preferably about 1 MPa or less, more preferably about 0.3 MPa or less. , about 0.1 to 0.3 MPa. By satisfying these differential pressures, when gas is generated inside the container 20, the gas can be suitably released to the outside, and water vapor (moisture) can be prevented from entering from the external environment. Can be highly suppressed.

The set pressure inside the battery cell 10 (container 20) to which the valve device 100 is attached is preferably set to a certain pressure or less. The set value of the internal pressure is appropriately set according to the type of package with a valve device, and is preferably about 0.1 MPa or less, more preferably about 1.0×10 ⁻² MPa or less. Approximately 1.0×10 ⁻¹⁰ MPa or more can be mentioned, and the preferable range of the internal pressure is about 1.0×10 ⁻¹⁰ to 0.1 MPa, 1.0×10 ⁻¹⁰ to 1.0×10 ⁻ About ² MPa can be mentioned.

In the valve device 100, the helium leak amount can be set by a known method. For example, the material, shape, and size of the members (for example, the ball 114, the valve seat 112, the spring 116, the vent O1) that constitute the valve device main body 110 (valve mechanism) of the valve device 100, and the spring 116 By designing the force for pressing the ball 114, the helium leak amount can be adjusted.

For example, by using an elastic body for one of the ball 114 and the valve seat 112 of the valve mechanism and using a high-hardness member such as metal for the other, the helium leak amount can be reduced to 5.0×10 ⁻¹¹ Pa·m ³ /sec. As mentioned above, it becomes easy to set to the range of 5.0*10 ^<-6> Pa*m ^<3> /sec or less. In order to reduce the helium leak amount, it is effective to use an elastic body for both the ball 114 and the valve seat 112 of the valve mechanism. Since it becomes difficult to appropriately release the gas generated inside to the outside, the material, shape, size, etc. of the members constituting the valve mechanism are appropriately adjusted. For example, in the valve mechanism, if the portion of the valve seat 112 that contacts the ball 114 has a shape that follows the surface shape of the ball 114, it is easy to design the helium leak amount within the above range.

That is, in the valve device 100, the helium leak amount is set in a range of about 5.0×10 ⁻¹¹ Pa·m ³ /sec to 2.0×10 ⁻¹⁰ Pa·m ³ /sec, furthermore, 5.0×10 ⁻ In order to set the pressure in the range of ¹¹ Pa·m ³ /sec to 1.5 × 10 ^-10 Pa·m ³ /sec, the valve mechanism of the valve mechanism must be adjusted to a high level that is not achieved with conventional check valves. It is necessary to design and process the shape of the portion where the seat 112 and the ball 114 contact each other with extremely high accuracy. For example, it is effective to set the average surface roughness of the surface of the valve seat 112 and the surface of the ball 114 to 20 μm or less, preferably 5 μm or less, more preferably 1 μm or less. However, if objects with high precision are brought into contact with each other, a problem may arise in that the valve device 100 does not operate properly (the valve device main body 110 does not open). It is necessary to adjust so that

<1-4. Structure of assembled battery>
FIG. 5 is a side view of the battery module 40 with a part of the exterior seen through. As shown in FIG. 5, the battery module 40 includes a plurality of battery cells 10 (10A, 10B, 10C, 10D) and an exterior pack 24. As shown in FIG.

The exterior pack 24 is a case that accommodates a plurality of battery cells 10 . A plurality of battery cells 10 are stacked (stacked) in the exterior pack 24 . The exterior pack 24 is formed with a hole through which the valve device 100 of each battery cell 10 penetrates. At least the valve device main body 110 (FIGS. 3 and 4) of each valve device 100 protrudes outside the exterior pack 24 through the hole. That is, in each valve device 100, the length of the gas passage portion 120 in the longitudinal direction is determined by accommodating the plurality of stacked battery cells 10 (accommodating body 20) in the exterior pack 24 to form the battery module 40. In this case, the valve device main body 110 is sufficiently long to be located outside the outer circumference of the exterior pack 24 . In the exterior pack 24, the plurality of battery cells 10 may be stacked in a horizontal direction, or may be stacked so that the plurality of battery cells 10 are in direct contact with each other. The members may be sandwiched between each other and stacked.

That is, even if one of the plurality of valve devices 100 in the battery module 40 operates, the gas released from the valve device 100 is released at a position away from the exterior pack 24 . Therefore, according to the valve device 100, since the gas is discharged to the outside of the outer pack 24, it is possible to prevent the gas from filling the outer pack 24 and degrading the outer layer of the container 20 (FIGS. 1 and 2). be able to.

Further, in the valve device 100, a certain length is ensured as the length of the gas passage portion 120 in the longitudinal direction, so that the following merits are obtained. Consider a case where the valve device body 110 is thicker than each container 20 . In this case, if the gas passage portion 120 is short or absent in the valve device 100, the adjacent valve devices 100 will come into contact with each other (the valve device 100 will become an obstacle) when a plurality of containers 20 are stacked, and each container 20 will cannot be superimposed in contact with each other. In valve device 100 according to the present embodiment, the longitudinal length of gas passage portion 120 is secured to some extent. Therefore, even if the valve device main body 110 is thicker than each containing body 20, even if a plurality of containing bodies 20 are stacked, the plurality of valve devices 100 simply spread in a fan shape, and each containing body 20 can be stacked in contact with each other.

<1-5. Features>
As described above, when valve device 100 according to the present embodiment is attached to container 20 , the tip of valve device 100 (valve device main body 110 ) is positioned outside the outer periphery of container 20 . That is, even if the valve device 100 is actuated, the gas released from the valve device 100 is released at a position away from the container 20 . Therefore, according to the valve device 100, since the discharged gas is less likely to hit the containing body 20, deterioration of the outer layer of the containing body 20 can be suppressed.

[2. Embodiment 2]
<2-1. Overview>
In Embodiment 1 described above, one valve device 100 is provided for one container 20 . In this case, when configuring the battery module 40 , as many valve devices 100 as the number of battery cells 10 (containers 20 ) included in the battery module 40 are used. As the number of valve devices 100 increases, the possibility of water vapor (moisture) entering from the secondary side of the valve device 100 to the primary side increases. In other words, the amount of moisture that permeates one battery cell 10 increases. Also, as the number of valve devices 100 increases, the cost increases.

In Embodiment 2, only one valve device is provided for a plurality of containers (battery cells). That is, in Embodiment 2, one valve device is provided for one battery module.

FIG. 6 is a side view of battery module 50 according to Embodiment 2, with a part of the exterior being transparent. As shown in FIG. 6, the battery module 50 includes a plurality of battery cells 60 (60A, 60B, 60C, 60D) and an exterior pack 26. As shown in FIG. In the battery module 50 , only one valve device 200 is provided for the plurality of battery cells 60 .

Therefore, according to the valve device 200, compared to the case where each of the plurality of battery cells 60 is provided with a valve device, the number of valve function units is reduced. can reduce the possibility of water vapor entering the In other words, the amount of moisture that permeates each battery cell 60 can be reduced. Further, according to the valve device 200, the number of valve devices is reduced compared to the case where each battery cell 60 is provided with one valve device, so the cost of the valve device in the battery module 50 can be suppressed.

Also, in the battery module 50 , the tip of the valve device 200 (valve device main body 210 (described later)) is positioned outside the exterior pack 26 . That is, even if the valve device 200 operates in the battery module 50 , the gas released from the valve device 200 is released at a position away from the exterior pack 26 . Therefore, according to the valve device 200, the gas is discharged to the outside of the exterior pack 26, so that it is possible to prevent the gas from filling the interior of the exterior pack 26 and degrading the outer layer of the housing of each battery cell 60. . The valve device 200 will be described in detail below.

<2-2. Configuration of valve device>
FIG. 7 is a top view of the valve device 200. FIG. FIG. 8 is a cross-sectional view taken along line VIII-VIII of FIG. As shown in FIGS. 7 and 8, the valve device 200 includes a valve device body 210, gas passage portions 220A, 220B, 220C and 220D, and mounting portions 230A, 230B, 230C and 230D. The valve device main body 210, the gas passage portions 220A, 220B, 220C, 220D, and the mounting portions 230A, 230B, 230C, 230D may be configured integrally or separately. For example, if each part is configured separately, it is possible to select different materials for each part.

The valve device main body 210 is made of, for example, metal, resin, or the like. When the pressure in the battery cell 60 rises due to gas generated in the battery cell 60 while the valve device 200 is attached to the battery cell 60 (container), the valve device body 210 reduces the pressure. It includes a lowering structure (valve seat 112, ball 114, spring 116, membrane 118 and vent O1). The structure is similar to that of the first embodiment. As a difference from the first embodiment, the air passage is branched into a plurality (four) at the lower part of the structure. A gas passage portion 220 is connected to each air passage, and a mounting portion 230 is connected to each gas passage portion 220 . The amount of helium leaked from valve device main body 210 (valve device 200) is the same as the amount of helium leaked from valve device 100 according to the first embodiment.

Each mounting portion 230 is similar to the mounting portion 130 in the first embodiment. Further, each gas passage portion 220 is the same as the gas passage portion 120 in the first embodiment except that the shape is different. The shape of each gas passage portion 220 is appropriately set according to the position in the battery module 50 of the battery cell 60 to which it is attached.

With the valve device 200 attached to the battery module 50, when the pressure in any one of the battery cells 60 reaches a predetermined pressure, the gas guided through the attachment portion 230 and the gas passage portion 220 moves the ball 114 through the vent hole. Press to the O1 side. When the ball 114 is pressed and the spring 116 is compressed, the gas in the battery cell 60 passes through the gap formed between the ball 114 and the valve seat 112, permeates the membrane 118, and exits the battery cell 60 through the vent O1. (battery module 50) is discharged to the outside.

<2-3. Features>
As described above, valve device 200 according to the second embodiment is attached to battery module 50 configured by stacking a plurality of containers (battery cells 60) each containing a battery element.

In the valve device 200 , only one valve device main body 210 is provided for the plurality of battery cells 60 . Therefore, according to the valve device 200, water vapor can enter the battery cell 60 (container) through minute gaps in the valve device main body 210, compared to the case where each of the plurality of battery cells 60 is provided with a valve device. Possibility of infiltration can be reduced.

Also, in the valve device 200 , only one valve device main body 210 is provided for the plurality of gas passage portions 220 . Therefore, according to the valve device 200, the number of valve device main bodies is reduced compared to the case where each gas passage portion 220 is provided with one valve device main body, so the cost of the valve device in the battery module 50 is suppressed. can do.

[3. Modification]
Although Embodiments 1 and 2 have been described above, the present invention is not limited to Embodiments 1 and 2, and various modifications can be made without departing from the scope of the invention. Modifications will be described below. However, the following modified examples can be combined as appropriate.

<3-1>
In Embodiments 1 and 2, the interior of gas passage portions 120 and 220 is hollow. However, the inside of gas passage portions 120 and 220 does not necessarily have to be hollow. For example, a desiccant such as silica may be held inside the gas passages 120 and 220 . For example, a desiccant is held on the inner wall surfaces of the gas passage portions 120 and 220 . In this case, when water vapor enters from the secondary side to the primary side of the valve device 100, 200, the influence of the water vapor can be reduced.

<3-2>
Moreover, the gas passage portions 120 and 220 in the first and second embodiments may be composed of, for example, bendable and stretchable flexible tubes. As a result, the gas discharge location can be adjusted more freely.

<3-3>
Further, the gas passage portion 120 in Embodiment 1 is not necessarily linear, and may be L-shaped, for example.

<3-4>
Further, by appropriately setting the shape and length of the gas passage portions 120 and 220 in Embodiments 1 and 2 above, it is possible to control where the gas is discharged by the valve devices 100 and 200 .

10, 10A, 10B, 10C, 10D, 60, 60A, 60B, 60C, 60D battery cell (single battery), 15 battery element, 20 container, 22 sealing part, 24, 26 exterior pack, 30, 30A, 30B electrode tab, 40,50 battery module (assembled battery), 100,100A, 100B, 100C, 100D, 200 valve device, 110,210 valve device body, 112 valve seat, 114 ball, 116 spring, 118 membrane, 120,220, 220A, 220B, 220C, 220D gas passage portion, 130, 230, 230A, 230B, 230C, 230D attachment portion, A1 ventilation path, O1 ventilation port.

Claims (9)

A valve device attached to a first container that contains a battery,
one valve device main body configured to reduce the pressure in the case where the pressure inside the first containing body rises due to the gas generated inside the first containing body;
a gas passage portion connected to the valve device main body and configured to allow the gas generated inside the first container to pass into the valve device main body;
The valve device, wherein the outer diameter of the valve device main body is longer than the outer diameter of the gas passage portion . 2. The valve device according to claim 1, wherein the gas passage portion has a length of 10 mm or more. 3. The valve device according to claim 1, wherein the gas passage portion is composed of a flexible tube . 4. The valve device according to any one of claims 1 to 3, wherein the gas passage portion is configured to retain a desiccant therein. 2. The method according to claim 1, wherein when an assembled battery is constructed by housing a plurality of the first housing bodies in a second housing body, the valve device main body is positioned outside an outer circumference of the second housing body. The described valve device. From the secondary side to the primary side of the valve device, measured in accordance with the method specified in JIS Z2331:2006 "Helium leak test method" and "Vacuum spray method (spray method)" in a 25°C environment. 6. The helium leak amount of 5.0×10 −11 Pa·m ³ /sec or more and 5.0×10 ⁻⁶ Pa·m ³ /sec or less according to any one of claims 1 to 5. valve device. A valve device attached to an assembled battery comprising a predetermined number of two or more containers each containing a battery,
one valve device main body configured to reduce the pressure when the pressure inside the containing bodies rises due to the gas generated in at least one of the predetermined number of containing bodies;
each of the predetermined number of gas passage portions connected to the predetermined number of containers and configured to allow gas generated in at least one of the containers to pass through the valve device main body;
One gas passage portion extends from each of the predetermined number of containers ,
A valve device , wherein each of the predetermined number of gas passage portions is not provided with a valve mechanism . the predetermined number of containers each containing a battery;
An assembled battery comprising the valve device according to claim 7 . a battery element;
and a housing that houses the battery element,
The container is composed of a laminate film including a heat-sealable resin layer,
further comprising a valve device attached to the container by being sandwiched between the heat-fusible resin layers;
The valve device is
configured to be attached to the container,
a valve device main body configured to reduce the pressure in the container when the pressure inside the container rises due to the gas generated inside the container;
a gas passage part connected to the valve device main body and configured to allow gas generated inside the container to pass into the valve device main body;
The battery, wherein the outer diameter of the valve device main body is longer than the outer diameter of the gas passage portion.

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