JP2020202103A - Battery pack - Google Patents

Abstract

To provide a battery pack in which adsorption performance for hydrogen sulfide gas is prevented from deteriorating over time and to which the type of porous adsorbent is not restricted.SOLUTION: In a battery pack 1 in which battery cells 10 using a sulfide-based solid electrolyte are housed in a battery case 20, the battery case 20 includes a battery cell accommodating portion 20A for accommodating the battery cells 10 and a hydrogen sulfide sensor 50, and an adsorbent accommodating portion 20B in which an adsorbent 30 capable of adsorbing hydrogen sulfide gas is air-tightly surrounded by a packaging material 25, and includes a releasing mechanism 60 for releasing the adsorbent 30 in the adsorbent accommodating portion 20B when the hydrogen sulfide sensor 50 detects hydrogen sulfide gas, thereby allowing the adsorbent 30 and gas existing in the battery cell accommodating portion 20A to come into contact with each other.SELECTED DRAWING: Figure 1

Description

The present invention relates to a battery pack in which a battery cell using a sulfide-based solid electrolyte is housed in a battery case.

In recent years, from the viewpoint of environmental protection, the development of electric vehicles or hybrid vehicles driven by electric motors has been actively promoted. The electric vehicle or hybrid vehicle is equipped with a battery pack in which a plurality of battery cells are connected in series or in parallel to serve as a power source for a driving electric motor.

Further, as this battery cell, a lithium ion secondary battery capable of high capacity and high output as compared with a lead storage battery or a nickel hydrogen battery is mainly used. Among the lithium ion secondary batteries, the all-solid-state lithium ion secondary battery, which has high safety, is attracting attention because it does not use an electrolytic solution composed of a flammable organic solvent. In this all-solid-state lithium ion secondary battery, for example, a sulfide-based solid electrolyte is preferably used instead of the electrolytic solution using an organic solvent.

However, the all-solid-state lithium ion secondary battery having the sulfide-based solid electrolyte, the air flowing from the outside of the battery is in contact with the sulfide-based solid electrolyte, hydrogen sulfide gas by moisture in the air (H 2 _S) is May occur. Hydrogen sulfide gas corrodes the electrodes and is highly toxic, so there is concern about its effects on the human body.

Therefore, it is necessary to adsorb the generated hydrogen sulfide gas. For example, in Patent Document 1, a porous adsorbent is housed in a container (battery case) together with an all-solid-state lithium ion secondary battery, and hydrogen sulfide is contained in the container. A molecule larger than the molecule of the above, for example, a gas such as nitrogen, argon or carbon dioxide is filled and pressurized.

JP 2013-65451

In Patent Document 1, the average size of the pores provided in the porous adsorbent is larger than the molecular diameter of hydrogen sulfide and smaller than the molecular diameter of the gas filled in the container. It is an adsorption mechanism that selectively captures hydrogen sulfide gas into the pores. However, the porous adsorbent is exposed in the container filled with gas, and the gas filled in the container is in a pressurized state. In addition, although the average size of the pores provided in the porous adsorbent is smaller than the molecular diameter of the gas filled in the container, the pore diameters are also distributed. Since the pores of the porous adsorbent may be larger than the molecular diameter of the gas filled in the container, the pores of the porous adsorbent are blocked by the filled gas such as nitrogen, and the adsorption performance of hydrogen sulfide gas is improved. There was a risk of deterioration over time. Further, there is a problem that the type of the porous adsorbent is also limited by the molecular diameter of the gas to be filled.

The present invention has been made in view of such a situation, and an object of the present invention is to provide a battery pack in which the adsorption performance for hydrogen sulfide gas is prevented from deteriorating with time and the type of porous adsorbent is not limited. To do.

The object of the present invention is achieved by the following (1) relating to the battery pack.
(1) A battery pack in which a battery cell using a sulfide-based solid electrolyte is housed in a battery case.
The battery case includes a battery cell accommodating portion for accommodating the battery cell and the hydrogen sulfide sensor.
An adsorbent accommodating part in which an adsorbent capable of adsorbing hydrogen sulfide gas is airtightly surrounded by a packaging material,
With
When the hydrogen sulfide sensor detects the hydrogen sulfide gas, the opening mechanism opens the adsorbent in the adsorbent accommodating portion so that the adsorbent and the gas existing in the battery cell accommodating portion can come into contact with each other. Has a battery pack.

A preferred embodiment of the present invention relating to a battery pack is one of the following (2) to (14).
(2) The battery pack according to (1) above, wherein the opening mechanism has a penetrating mechanism for penetrating the packaging material or a breaking mechanism for breaking the packaging material.
(3) The battery cell accommodating portion and the adsorbent accommodating portion are connected via an on-off valve.
The battery pack according to (1) above, wherein the opening mechanism has an opening / closing mechanism for opening / closing the on-off valve.
(4) The battery pack according to (2) or (3) above, wherein the adsorbent accommodating portion is arranged vertically below the battery cell.

(5) The adsorbent accommodating portion is provided with an opening that can open the adsorbent by increasing the internal pressure in the adsorbent accommodating portion.
The battery pack according to (1) above, wherein the opening mechanism has a pressurizing mechanism for pressurizing the inside of the adsorbent accommodating portion.
(6) The adsorbent is in powder form and is in the form of powder.
The battery pack according to (5) above, wherein the adsorbent accommodating portion is arranged on the upper side in the vertical direction with respect to the battery cell.
(7) The battery pack according to (6) above, wherein the opening is arranged directly above the battery cell.
(8) The battery pack according to any one of (5) to (7) above, wherein a plurality of the opening ports are arranged.

(9) The battery pack according to any one of (1) to (8) above, wherein the inside of the adsorbent accommodating portion is in a vacuum state or a reduced pressure state.
(10) The hydrogen sulfide sensor is connected to a notification means for notifying the outside.
The battery pack according to any one of (1) to (9) above, which notifies the outside when the hydrogen sulfide sensor detects the hydrogen sulfide gas.
(11) The battery pack according to any one of (1) to (10) above, wherein the packaging material is made of a gas impermeable or gas impermeable material.
(12) The packaging material has a gas permeability measured in accordance with JIS K 6275-1 (2009) or JIS K 7126-1 (2006) at 100 cc / cm ² for both nitrogen gas and oxygen gas. / mm / sec / cmHg × is ^{10 10} or less, and, and a 10000cc ^/ cm 2 ^/ mm ^/ sec / cmHg × ^{10 10} or more materials to water vapor, the (1) to (10) The battery pack described in any one.
(13) The packaging material is composed of at least one selected from rubber hydrochloride, polyamide, polyacetal, cellulose acetate, polybutadiene-acrylonitrile, polystyrene, polyurethane, chlorosulphonized polyethylene and chloroprene rubber, as described in (12) above. Battery pack.
(14) The adsorbent is an activated carbon, zeolite, metal silicate, silica gel, and at least one metal selected from zinc, iron, nickel, tin, copper and silver, an oxide of the metal and the metal. The battery pack according to any one of (1) to (13) above, which is at least one selected from the group consisting of hydroxides.

According to the battery pack according to the present invention, it is possible to prevent the adsorption performance for hydrogen sulfide gas from deteriorating with time, and to exhibit sufficient adsorption performance when hydrogen sulfide gas is generated. Further, there is no limitation on the type of the porous adsorbent as long as it is an adsorbent capable of adsorbing hydrogen sulfide gas.

FIG. 1 is a diagram schematically showing a first embodiment of a battery pack according to the present invention. FIG. 2 is a diagram schematically showing a second embodiment of the battery pack according to the present invention. FIG. 3 is a diagram schematically showing a third embodiment of the battery pack according to the present invention.

<First Embodiment>
FIG. 1 is a diagram schematically showing a first embodiment of a battery pack according to the present invention. The battery pack 1 according to the present embodiment contains a battery cell 10 using a sulfide-based solid electrolyte in a battery case 20. Further, in the battery case 20, the battery cell accommodating portion 20A accommodating the battery cell 10 and the hydrogen sulfide sensor 50 and the adsorbent 30 capable of adsorbing hydrogen sulfide gas are hermetically surrounded by the packaging material 25. It has a part 20B.

Although not shown, the battery cell 10 using the sulfide-based solid electrolyte has a sulfide-based solid electrolyte sandwiched between the positive electrode and the negative electrode, and the entire cell is airtightly surrounded by, for example, a sealing member. The battery case 20 Is housed in. Then, when the battery case 20 and the battery cell 10 are damaged due to an external factor or the like, the seal member is broken, and the moisture contained in the air or the like comes into contact with the sulfide-based solid electrolyte, hydrogen sulfide gas is produced. May occur.

Therefore, in order to adsorb the generated hydrogen sulfide gas, the battery pack 1 according to the present embodiment includes an adsorbent 30 capable of adsorbing the hydrogen sulfide gas in the battery case 20. Further, in the battery pack 1, when the hydrogen sulfide sensor 50 detects hydrogen sulfide gas in the battery case 20, the adsorbent 30 in the adsorbent accommodating portion 20B is opened, and the adsorbent 30 and the battery cell accommodating portion are opened. It is provided with an opening mechanism 60 that makes contact with the gas existing in 20A.

Here, the reason why the battery pack 1 according to the present invention includes the opening mechanism 60 will be described below.

As described above, in Patent Document 1, the average size of the pores provided in the porous adsorbent is larger than the molecular diameter of hydrogen sulfide and smaller than the molecular diameter of the gas filled in the container. Although it has an adsorption mechanism that selectively captures the generated hydrogen sulfide gas into the pores, some of the pores may be larger than the molecular diameter of the gas filled in the container. The pores of the porous adsorbent may be clogged by the filled gas such as nitrogen, and the adsorption performance of the hydrogen sulfide gas may deteriorate over time. Further, there is a problem that the type of the porous adsorbent is also limited by the molecular diameter of the gas to be filled.

Therefore, the present inventors airtightly surround the adsorbent 30 with the packaging material 25 to prevent the invasion of gases such as nitrogen gas and oxygen gas existing outside the adsorbent 30, and hydrogen sulfide from the battery cell 10. When gas is generated, the hydrogen sulfide gas is detected by the hydrogen sulfide sensor 50, and based on the detection, the adsorbent 30 is released from the packaging material 25 so that it can come into contact with the hydrogen sulfide gas generated from the battery cell 10. We considered adopting the opening mechanism 60. Then, according to such an opening mechanism 60, when hydrogen sulfide gas is not generated, the nitrogen gas and oxygen gas existing in the battery case 20 permeate through the packaging material 25, and the pores of the adsorbent 30 are formed. It is possible to suppress the blockage of the gas, and when hydrogen sulfide gas is generated from the battery cell 10, the adsorbent 30 and the hydrogen sulfide gas can be brought into contact with each other to effectively adsorb the hydrogen sulfide gas. I found out what I could do.

Hereinafter, each component of the battery pack 1 will be described in detail.

(Battery case)
In the battery case 20, the battery cell accommodating portion 20A accommodating the battery cell 10 using the sulfide-based solid electrolyte and the hydrogen sulfide sensor 50 and the adsorbent 30 capable of adsorbing hydrogen sulfide gas are hermetically surrounded by the packaging material 25. It has an adsorbent accommodating portion 20B made of sulfur.

(Battery cell housing)
The battery cell accommodating portion 20A is a portion in the battery case 20 accommodating the battery cell 10 using the sulfide-based solid electrolyte and the hydrogen sulfide sensor 50.

The battery cell 10 using the sulfide-based solid electrolyte has a sulfide-based solid electrolyte sandwiched between a positive electrode and a negative electrode, and the entire cell is airtightly surrounded by, for example, a sealing member. It is attached to the equipment used in. As described above, the battery cell 10 using the sulfide-based solid electrolyte is sulfided when the battery cell 10 is damaged due to an external factor or the like and the moisture contained in the air or the like comes into contact with the sulfide-based solid electrolyte. It can be a source of hydrogen gas. As shown in FIG. 1, in the battery cell 10, the battery case 20 is in a state where a plurality of battery cells 10 are connected in series or in parallel for the purpose of increasing the capacity (the connection state is not shown). Although it is often housed in the battery cell 10, the battery cell 10 may be used alone if necessary.

The hydrogen sulfide sensor 50 plays a role of detecting the hydrogen sulfide gas generated from the battery cell 10 in the battery cell accommodating portion 20A. The hydrogen sulfide sensor 50 is not particularly limited as long as it can detect hydrogen sulfide gas, and known ones such as an electrolytic sensor, a thin film sensor, a ceramic sensor, an organic material sensor, an electrolytic material sensor, and a thermocouple sensor are used. can do.

The battery cell accommodating portion 20A may be airtight, but may be connected to the outside so that air can flow in. The battery cell 10 can be air-cooled by communicating with the outside. Further, in the present embodiment, since the battery cell 10 is a heavy object, it is placed on, for example, a breathable mesh-shaped pedestal 40. Further, the hydrogen sulfide sensor 50 is mounted on the pedestal 40 in the vicinity of the battery cell 10.

(Adsorbent housing)
The adsorbent accommodating portion 20B is a portion in the battery case 20 in which the adsorbent 30 capable of adsorbing hydrogen sulfide gas is airtightly surrounded by the packaging material 25.

The adsorbent 30 capable of adsorbing hydrogen sulfide gas is not limited as long as it is a material capable of adsorbing hydrogen sulfide gas, and is limited to activated carbon, zeolite, metal silicate, silica gel, and zinc, iron, nickel, tin, copper and silver. Such as metals, oxides of these metals, hydroxides of these metals and the like, and these may be used alone or in combination.

The type of activated carbon is not particularly limited, and examples thereof include those using coconut husk, coal, charcoal, and the like as main raw materials.

The metal silicate is, for example, a metal silicate containing at least one metal selected from copper, zinc, manganese, cobalt, and nickel described in Japanese Patent No. 6164900.

The type of zeolite is not particularly limited, and examples thereof include β-type zeolite, Y-type zeolite, ferrierite, ZSM-5 type zeolite, mordenite, forgesite, zeolite A, and zeolite L.

From the viewpoint of improving the adsorption rate, it is preferable to use any of activated carbon, zeolite, and silica gel as the adsorbent 30. From the viewpoint of improving the adsorptive power, the adsorbent 30 is a metal silicate, or at least one metal selected from zinc, iron, nickel, tin, copper and silver, an oxide of the metal and the metal. It is preferable to use at least one selected from the group consisting of hydroxides of.

Further, the adsorbent 30 may be in the form of powder, or may be contained as it is in the packaging material 25 described later. Further, the powder of the adsorbent 30 may be bound with an appropriate binder and processed into a sheet, or the powder of the adsorbent 30 may be integrated into a layer on one side or both sides of an appropriate support. A form integrated with the sheet or the support may be airtightly surrounded by the packaging material 25.

When the adsorbent 30 is in the form of powder, the average particle size of the powder is preferably as small as possible because the surface area per unit mass is larger, and specifically, it is preferably 0.5 to 100 μm. It is more preferably 0.5 to 10 μm.

As the binder, styrene-butadiene rubber (SBR), silicone resin, acrylic resin, polystyrene, polybutadiene and the like can be used. Above all, it is more preferable to use styrene-butadiene rubber (SBR) because the permeability of hydrogen sulfide gas is particularly high. The amount of the binder used is preferably 0.5 to 5% by mass with respect to the total amount of the adsorbent 30 and the binder.

The support is not particularly limited as long as it can support the powder of the adsorbent 30, and various materials including organic materials such as resin and inorganic materials such as metal and glass may be used. Can be done. In addition, a large number of fine through holes may be formed in the support so that the hydrogen sulfide gas can easily reach the interface between the adsorbent 30 and the support.

Subsequently, the packaging material 25 is preferably made of a material that is impermeable to gas or impervious to gas, and specifically, a material that does not substantially allow gas to permeate, such as a metal foil, is preferable. Since the packaging material 25 is made of a gas impermeable or gas impermeable material, nitrogen gas or oxygen gas is used as the packaging material when hydrogen sulfide gas is not generated in the battery cell accommodating portion 20A. It is possible to prevent the adsorbent 30 from being blocked by passing through 25.

Further, the packaging material 25 may be a sheet or film made of a material having a gas permeability of polar molecules higher than that of the gas permeability of non-polar molecules. Here, nitrogen gas and oxygen gas, which are abundant in the atmosphere, have a relatively large molecular diameter and are so-called non-polar molecules. On the other hand, hydrogen sulfide gas that can be generated from the battery cell 10 and the atmosphere, etc. The water vapor present in is a so-called polar molecule as well as having a relatively small molecular diameter as compared with nitrogen gas and oxygen gas. Therefore, it can be said that the packaging material 25 is made of a material that easily permeates hydrogen sulfide gas and water vapor having a relatively small molecular diameter and hardly permeates nitrogen gas and oxygen gas having a relatively large molecular diameter. Specifically, the packaging material 25 has a gas permeability of 100 cc / cm ² / mm / sec / cmHg × 10 ¹⁰ or less for both nitrogen gas and oxygen gas, and 10000 cc / cm ² for water vapor. / Mm/sec/cmHg × 10 ¹⁰ or more is preferable.

In order to effectively suppress the permeation of nitrogen gas and oxygen gas in the packaging material 25, the gas permeation rate is 50 cc / cm ² / mm / sec / cmHg × 10 ¹⁰ for both nitrogen gas and oxygen gas. It is more preferably 10 cc / cm ² / mm / sec / cmHg × 10 ¹⁰ or less. Further, in order to effectively permeate the water vapor in the packaging material 25 (the original purpose is to effectively permeate hydrogen sulfide gas), the gas permeation rate is 12000 cc / cm ² / for both water vapor. more preferably mm / sec / cmHg × is ^{10 10} or more, still more preferably 15000cc ^/ cm 2 ^/ mm ^/ sec / cmHg × ^{10 10} or more.

Here, the reason why the material physical properties of the packaging material 25 are such that the gas permeability of the non-polar molecule is low and the gas permeability of the polar molecule is high will be described below.

As described above, in Patent Document 1, the average size of the pores provided in the porous adsorbent is larger than the molecular diameter of hydrogen sulfide and smaller than the molecular diameter of the gas filled in the container. Although it has an adsorption mechanism that selectively captures the generated hydrogen sulfide gas into the pores, some of the pores may be larger than the molecular diameter of the gas filled in the container. The pores of the porous adsorbent may be clogged by the filled gas such as nitrogen, and the adsorption performance of the hydrogen sulfide gas may deteriorate over time. Further, there is a problem that the type of the porous adsorbent is also limited by the molecular diameter of the gas to be filled.

Therefore, as a packaging material 25 that airtightly surrounds the adsorbent 30, the present inventors consider that the pores of the adsorbent 30 can be blocked while allowing the hydrogen sulfide gas to permeate relatively easily in the air. If a material having material properties that block existing nitrogen gas and oxygen gas is adopted, the nitrogen gas and oxygen gas permeate through the packaging material 25 and the pores of the adsorbent 30 when hydrogen sulfide gas is not generated. In addition, when hydrogen sulfide gas is generated from the battery cell 10, the packaging material 25 selectively permeates the hydrogen sulfide gas to close the pores of the adsorbent 30. I thought that it might be possible to effectively adsorb hydrogen sulfide gas.

Then, as a method for defining the material properties capable of blocking nitrogen gas and oxygen gas while allowing hydrogen sulfide gas to permeate relatively easily, hydrogen sulfide gas is a polar molecule, and nitrogen gas and oxygen gas are non-polar molecules. It has been found that the problem of the present invention can be solved by adopting a packaging material 25 having a gas permeability of polar molecules larger than that of nonpolar molecules.

It should be noted that water vapor (water molecule) is a polar molecule having a molecular diameter close to that of hydrogen sulfide gas, and is often described by the gas permeability of water vapor in the literature values of general gas permeability. In the present invention, it is defined by substituting the gas permeability with respect to water vapor. Further, the transmittance of the gas is specified in JIS K 6275-1 (2009) for the rubber film and JIS K 7126-1 (2006) for the plastic film. Therefore, in the present invention, the gas based on these JIS is specified. Adopt transmittance.

Examples of materials that can satisfy such gas permeability include rubber hydrochloride, polyamide, polyacetal, cellulose acetate, polybutadiene-acrylonitrile, polystyrene, polyurethane, chlorosulfonized polyethylene, and chloroprene rubber. Depending on the type of material, there is a range of numerical values for gas permeability. As an example, the gas permeability of polyamide is 0.1 to 0.2 cc / cm ² / mm / sec / sec for nitrogen gas. cmHg × ^{10 10,} a 700~17000cc ^/ cm 2 ^/ mm ^/ sec / cmHg × ^{10 10} for 0.38cc ^/ cm 2 ^/ mm ^/ sec / cmHg × ^{10 10,} the steam to oxygen gas ( Homepage of Junkosha Inc.; http://junkosha.co.jp/technical/tec8.html, see "2-3 Gas permeability of tube material"). In this case, for example, the degree of polymerization and crystallinity of the polymer can be adjusted, or known means such as modification can be appropriately adjusted so as to satisfy the above-mentioned preferable gas permeability.

Among the materials that can satisfy the gas permeability, it is preferable to use any of rubber hydrochloride, polyamide, and polyacetal, which have relatively lower gas permeability to nitrogen gas and oxygen gas.

The thickness of the packaging material 25 is not particularly limited, and may be the same as that of general paper, sheet, or film, and for example, 0.05 mm to 0.25 mm is suitable. However, from the viewpoint of effectively suppressing the permeation of nitrogen gas and oxygen gas, the thickness of the packaging material 25 is preferably 0.08 mm or more, and more preferably 0.10 mm or more. Further, from the viewpoint of effectively exerting the permeation of water vapor gas and hydrogen sulfide gas, the thickness of the packaging material 25 is preferably 0.20 mm or less, and more preferably 0.15 mm or less.

Further, the packaging material 25 is hermetically sealed, that is, airtightly sealed by hot-sealing its ends (four corners) in a state where the adsorbent 30 is housed. At the time of sealing, for example, the inside of the packaging material 25 is adsorbed in a vacuum or a state close to vacuum (that is, a vacuum state or a reduced pressure state) so that nitrogen gas or oxygen gas does not enter the inside of the packaging material 25. It is preferable to house the material 30. By doing so, even before the adsorbent 30 and the gas existing in the battery cell accommodating portion 20A can be brought into contact with each other by the opening mechanism 60, nitrogen gas, oxygen gas, etc. that can exist in the packaging material 25 can be removed. Since the gas can be reduced as much as possible and the gas in the packaging material 25 can be prevented from clogging the pores of the adsorbent 30, the adsorbent 30 can obtain a higher adsorption effect of hydrogen sulfide gas. .. The "vacuum state" indicates a state in which the pressure is zero, and the "decompression state" indicates a state in which the pressure is lower than the atmospheric pressure.

In the adsorbent accommodating portion 20B configured as described above, when hydrogen sulfide gas is not generated from the battery cell 10, nitrogen gas or oxygen gas cannot enter the inside of the packaging material 25, for example, the adsorbent. Even when the pores of 30 are larger than the molecular diameter of nitrogen gas or oxygen gas, the pores of the adsorbent 30 are not blocked, so that the adsorption performance of hydrogen sulfide gas does not deteriorate over time. , The adsorbent 30 is maintained in a state close to that at the time of manufacture.

As shown in FIG. 1, the adsorbent accommodating portion 20B is preferably arranged on the lower side in the vertical direction than the battery cell 10. Since the hydrogen sulfide gas is heavier than air, the adsorbent 30 effectively adsorbs the hydrogen sulfide gas by arranging the adsorbent accommodating portion 20B below the battery cell 10 which is the source of the hydrogen sulfide gas. be able to.

(Opening mechanism)
When the hydrogen sulfide sensor 50 detects hydrogen sulfide gas, the opening mechanism 60 opens the adsorbent 30 in the adsorbent accommodating portion 20B, and the adsorbent 30 and the gas existing in the battery cell accommodating portion 20A (sulfurization). It plays a role of making contact with hydrogen, air, etc.). Then, as shown in FIG. 1, this opening mechanism 60 is connected to the hydrogen sulfide sensor 50, and in conjunction with the detection of hydrogen sulfide gas by the hydrogen sulfide sensor 50, the adsorbent 30 in the adsorbent accommodating portion 20B Performs a predetermined operation for releasing.

For example, the opening mechanism 60 has a penetrating mechanism for penetrating the packaging material 25, and specific examples thereof include needles. Further, as another example, the opening mechanism 60 has a breaking mechanism for breaking the packaging material 25, and specific examples thereof include a cutting edge. That is, when the hydrogen sulfide gas generated from the battery cell 10 is detected by the hydrogen sulfide sensor 50, the needle and the cutting edge of the opening mechanism 60 are interlocked with the detection by the hydrogen sulfide sensor 50, and the through hole is formed in the packaging material 25. Or cut the packaging material 25. As a result, the generated hydrogen sulfide gas can flow into the adsorbent accommodating portion 20B from the through hole or the cut portion, and is easily adsorbed by the adsorbent 30.

Further, although not shown, when a material such as rubber or plastic having a relatively low melting point is used as the packaging material 25, for example, a form in which a metal mesh is attached to the packaging material 25 can be used. In this case, the opening mechanism 60 can be a heater (heat source) connected to a metal mesh. When the hydrogen sulfide gas generated from the battery cell 10 is detected by the hydrogen sulfide sensor 50, the heater, which is the opening mechanism 60, starts generating heat in conjunction with the detection by the hydrogen sulfide sensor 50, thereby causing a metal mesh. Is heated. Further, since the packaging material 25 in contact with the heated metal mesh melts to form a hole in the packaging material 25, the generated hydrogen sulfide gas can flow into the adsorbent accommodating portion 20B. ..

As another method, a metal body in which a heating wire such as a nichrome wire is assembled in a mesh shape is attached to the packaging material 25, and the opening mechanism 60 can be a switch connected to the heating wire. In this case, when the hydrogen sulfide gas generated from the battery cell 10 is detected by the hydrogen sulfide sensor 50, the heating wire is heated by turning on the switch which is the opening mechanism 60, thereby heating in the same manner as described above. It is also possible to make a hole in the packaging material 25 by melting the packaging material 25 that comes into contact with the heated wire.

Further, when the packaging material 25 is melted by heating to make a hole, it is preferable to use a heat-shrinkable film as the packaging material 25. By using the heat-shrinkable film, the packaging material 25 is easily broken by heat shrinkage, and holes can be easily formed in the packaging material 25 at a low heating temperature stage, and in the initial stage of hydrogen sulfide gas generation, It becomes possible to start adsorption by the adsorbent 30. In this case, it is preferable to form a thin-walled portion on the packaging material 25 because the heat-shrinkable film is likely to break from the thin-walled portion at the time of heat shrinkage. In addition to the linear shape, the thin-walled portion may be formed in a dot shape at appropriate intervals.

As a specific material of the heat-shrinkable film, for example, polyvinyl chloride, polystyrene, polyethylene terephthalate, polyethylene, polypropylene and the like can be used.

<Second Embodiment>
FIG. 2 is a diagram schematically showing a second embodiment of the battery pack according to the present invention. The battery pack 1 according to the present embodiment is different from the first embodiment in that an on-off valve 26 is installed between the opening mechanism 60 and the adsorbent accommodating portion 20B. Other configurations are the same as those in the first embodiment. That is, the battery cell accommodating portion 20A and the adsorbent accommodating portion 20B are connected to each other via an on-off valve 26 so that gas can flow back and forth. In this case, the opening mechanism 60 may have an opening / closing mechanism for opening / closing the on-off valve 26, and specifically, an opening / closing switch for opening / closing the on-off valve 26. Then, in the state before the generation of hydrogen sulfide gas, the on-off valve 26 is kept in the closed state, and when the hydrogen sulfide gas generated from the battery cell 10 is detected by the hydrogen sulfide sensor 50, the on-off switch which is the opening mechanism 60 is used. By switching the on-off valve 26 to the open state, hydrogen sulfide gas flows into the adsorbent accommodating portion 20B through the on-off valve 26 and is adsorbed by the adsorbent 30.

<Third Embodiment>
FIG. 3 is a diagram schematically showing a third embodiment of the battery pack according to the present invention. When the adsorbent 30 is in the form of powder, as shown in FIG. 3, the battery pack 1 has the adsorbent accommodating portion 20B arranged vertically above the battery cell 10 and is placed in the adsorbent accommodating portion 20B. It may have a form in which an opening 27 capable of opening the adsorbent 30 by increasing the internal pressure in the adsorbent accommodating portion 20B is provided. In this case, the opening mechanism 60 can be a pressurizing mechanism that pressurizes the inside of the adsorbent accommodating portion 20B.

In the present embodiment, when the hydrogen sulfide gas generated from the battery cell 10 is detected by the hydrogen sulfide sensor 50, the pressurizing means, which is the opening mechanism 60, is linked to the detection by the hydrogen sulfide sensor 50 and is an adsorbent. Pressurize the inside of the accommodating portion 20B. As a result, the internal pressure in the adsorbent accommodating portion 20B increases, and the opening 27 is opened. Therefore, the powdery adsorbent 30 accommodated in the adsorbent accommodating portion 20B is ejected from the opening 27, and the battery It is poured into cell 10. Therefore, the hydrogen sulfide gas generated from the battery cell 10 is adsorbed by the adsorbent 30.

Here, the opening 27 capable of opening the adsorbent 30 by increasing the internal pressure in the adsorbent accommodating portion 20B is a material that is more easily broken than the packaging material 25 (for example, a material similar to the packaging material 25). A material having a thickness but a thin thickness, or a material having the same thickness as the packaging material 25 but having a weak strength, etc.) can be adopted. Alternatively, it may have a mechanism capable of opening the opening 27 in conjunction with an increase in the internal pressure in the adsorbent accommodating portion 20B.

Even if the adsorbent 30 is in the form of powder, the adsorbent accommodating portion 20B may be arranged vertically below the battery cell 10, but in this case, the opening 27 Since the adsorbent 30 ejected from the adsorbent 30 is not directly poured onto the battery cell 10, the adsorbing effect of the hydrogen sulfide gas of the adsorbent 30 may not be sufficiently expected. Therefore, it is preferable that the adsorbent accommodating portion 20B is arranged on the upper side in the vertical direction with respect to the battery cell 10.

Further, when the opening 27 is arranged directly above the battery cell 10, the powdery adsorbent 30 can be efficiently poured onto the battery cell 10, which is particularly preferable. Further, in FIG. 3, only one opening port 27 is arranged in the adsorbent accommodating portion 20B, but by arranging a plurality of the opening ports 27, when a plurality of battery cells 10 are present, the powder is formed over a wide range. It is particularly preferable because the adsorbent 30 of the above can be poured.

Although various embodiments have been described above with reference to the drawings, it goes without saying that the present invention is not limited to such examples. It is clear that a person skilled in the art can come up with various modifications or modifications within the scope of the claims, which naturally belong to the technical scope of the present invention. Understood. Further, each component in the above embodiment may be arbitrarily combined as long as the gist of the invention is not deviated.

In addition to the above basic configuration, the hydrogen sulfide sensor 50 is connected to a notification means (not shown) for notifying the outside, and when the hydrogen sulfide sensor 50 detects hydrogen sulfide gas, it is external. It may be configured to notify the user. By having the above-mentioned notification means, it is possible to evacuate from the battery pack 1 by notifying the generation of hydrogen sulfide gas to the outside.

1 Battery pack 10 Battery cell 20 Battery case 20A Battery cell housing 20B Adsorbent storage 25 Packaging material 26 Opening valve 27 Opening port 30 Adsorbent 40 Pedestal 50 Hydrogen sulfide sensor 60 Opening mechanism

Claims (14)

A battery pack in which a battery cell using a sulfide-based solid electrolyte is housed in a battery case.
The battery case includes a battery cell accommodating portion for accommodating the battery cell and the hydrogen sulfide sensor.
An adsorbent accommodating part in which an adsorbent capable of adsorbing hydrogen sulfide gas is airtightly surrounded by a packaging material,
With
When the hydrogen sulfide sensor detects the hydrogen sulfide gas, the opening mechanism opens the adsorbent in the adsorbent accommodating portion so that the adsorbent and the gas existing in the battery cell accommodating portion can come into contact with each other. Has a battery pack. The battery pack according to claim 1, wherein the opening mechanism has a penetrating mechanism for penetrating the packaging material or a breaking mechanism for breaking the packaging material. The battery cell accommodating portion and the adsorbent accommodating portion are connected via an on-off valve.
The battery pack according to claim 1, wherein the opening mechanism has an opening / closing mechanism for opening / closing the on-off valve. The battery pack according to claim 2 or 3, wherein the adsorbent accommodating portion is arranged vertically below the battery cell. The adsorbent accommodating portion includes an opening that can open the adsorbent by increasing the internal pressure in the adsorbent accommodating portion.
The battery pack according to claim 1, wherein the opening mechanism has a pressurizing mechanism that pressurizes the inside of the adsorbent accommodating portion. The adsorbent is in powder form and
The battery pack according to claim 5, wherein the adsorbent accommodating portion is arranged on the upper side in the vertical direction with respect to the battery cell. The battery pack according to claim 6, wherein the opening is arranged directly above the battery cell. The battery pack according to any one of claims 5 to 7, wherein a plurality of the opening ports are arranged. The battery pack according to any one of claims 1 to 8, wherein the inside of the adsorbent accommodating portion is in a vacuum state or a reduced pressure state. The hydrogen sulfide sensor is connected to a notification means for notifying the outside.
The battery pack according to any one of claims 1 to 9, wherein when the hydrogen sulfide sensor detects the hydrogen sulfide gas, the battery pack notifies the outside. The battery pack according to any one of claims 1 to 10, wherein the packaging material is made of a gas impermeable or gas impermeable material. The packaging material has a gas permeability measured in accordance with JIS K 6275-1 (2009) or JIS K 7126-1 (2006) with respect to both nitrogen gas and oxygen gas at 100 cc / cm ² / mm / mm. sec / cmHg × is ^{10 10} or less, and, and a 10000cc ^/ cm 2 ^/ mm ^/ sec / cmHg × ^{10 10} or more materials to water vapor, according to any one of claims 1 to 10 Battery pack. The battery pack according to claim 12, wherein the packaging material comprises at least one selected from rubber hydrochloride, polyamide, polyacetal, cellulose acetate, polybutadiene-acrylonitrile, polystyrene, polyurethane, chlorosulphonized polyethylene and chloroprene rubber. The adsorbent is activated carbon, zeolite, metal silicate, silica gel, and at least one metal selected from zinc, iron, nickel, tin, copper and silver, oxides of the metals and hydroxides of the metals. The battery pack according to any one of claims 1 to 13, which is at least one selected from the group consisting of.

Images