Battery pack and method for removing hydrogen sulfide in battery pack

Abstract

The present disclosure provides a battery pack capable of effectively removing hydrogen sulfide generated from a battery including a sulfide solid electrolyte, and a method for removing such hydrogen sulfide in the battery pack. This battery pack (1) is provided with: an outer container (10); a battery (20) that is housed in the outer container (10) and contains a sulfide solid electrolyte; and a hydrogen sulfide absorbent (40) that is housed in the outer container (10) or is disposed in a flow path (30) that communicates with the interior of the outer container (10). The hydrogen sulfide absorbent is selected from zinc oxide, limestone, dolomite or a combination thereof. A method of the present disclosure of removing hydrogen sulfide in a battery pack includes removing hydrogen sulfide in a battery pack of the present disclosure by a hydrogen sulfide absorbent.

Description

Technical Field

[0001] The present disclosure relates to a battery pack and a method for removing hydrogen sulfide in the battery pack. Background Art

[0002] A battery pack having a plurality of batteries is known. When the battery is a battery having a sulfide solid electrolyte, the sulfide solid electrolyte and water may react to produce hydrogen sulfide (H2S). In this regard, a technology has been developed to suppress the increase in the concentration of hydrogen sulfide in the battery pack.

[0003] For example, Patent Document 1 discloses an all-solid-state battery pack, which is constructed as follows: the all-solid-state battery cell includes a positive electrode, a negative electrode and a sulfide-based solid electrolyte, and when the temperature of the all-solid-state battery cell rises above a threshold value, an inert gas is sprayed into the all-solid-state battery cell with the increased temperature, and when the concentration of hydrogen sulfide further rises above the threshold value, in addition to spraying the inert gas, an alkaline gas is also sprayed.

[0004] Patent document 2 discloses a battery pack mounted on a mobile body, which comprises a battery case and an adsorbent. The battery case houses an all-solid-state battery containing a sulfur-based material in a positive electrode and / or a solid electrolyte. The adsorbent is arranged at the bottom of the battery case and adsorbs hydrogen sulfide. The adsorbent is arranged at the outer periphery of the bottom.

[0005] Prior art literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2022-014295

[0007] Patent Document 2: Japanese Patent Application Publication No. 2022-167149 Summary of the invention

[0008] An object of the present disclosure is to provide a battery pack capable of effectively removing hydrogen sulfide generated from a battery containing a sulfide solid electrolyte, and a method for removing such hydrogen sulfide in the battery pack.

[0009] The present inventors have found that the above-mentioned problems can be solved by the following means.

[0010] <Method 1>

[0011] A battery pack having:

[0012] external container;

[0013] a battery contained in the outer container and containing a sulfide solid electrolyte; and

[0014] a hydrogen sulfide absorbent contained in the outer container or disposed in a flow path communicating with the outer container, and

[0015] The hydrogen sulfide absorbent is selected from zinc oxide, limestone, dolomite or a combination thereof.

[0016] <Method 2>

[0017] The battery pack according to aspect 1 further includes a heater for heating the hydrogen sulfide absorbent.

[0018] <Method 3>

[0019] According to the battery pack of aspect 2, a power source for the heater is the battery.

[0020] <Method 4>

[0021] The battery pack according to any one of aspects 1 to 3,

[0022] The flow path is a circulation path for circulating the gas in the outer container.

[0023] The battery pack further includes an oxygen absorber housed in the outer container or disposed in a circulation path communicating with the outer container.

[0024] <Method 5>

[0025] A method for removing hydrogen sulfide in a battery pack,

[0026] The battery pack has:

[0027] external container;

[0028] a battery contained in the outer container and containing a sulfide solid electrolyte; and

[0029] a hydrogen sulfide absorbent contained in the outer container or disposed in a flow path communicating with the outer container,

[0030] The hydrogen sulfide absorbent is selected from zinc oxide, limestone, dolomite or a combination thereof, and

[0031] The method comprises removing the hydrogen sulfide by the hydrogen sulfide absorbent.

[0032] <Method 6>

[0033] According to the method described in method 5,

[0034] The battery pack further comprises a heater for heating the hydrogen sulfide absorbent.

[0035] The method further includes heating the hydrogen sulfide absorbent by the heater when one or more values ​​selected from the group consisting of the temperature, the pressure, and the concentration of the hydrogen sulfide of the battery pack reaches or exceeds a threshold value.

[0036] <Method 7>

[0037] The method according to mode 5 or 6,

[0038] The flow path is an exhaust flow path for discharging the gas in the outer container to the outside of the outer container.

[0039] The hydrogen sulfide absorbent is disposed in the exhaust gas flow path, and

[0040] The method further includes exhausting the hydrogen sulfide absorbent from the exhaust flow path when the temperature of the hydrogen sulfide absorbent reaches or exceeds a threshold value.

[0041] <Method 8>

[0042] The method according to mode 5 or 6,

[0043] The flow path is a circulation path for circulating the gas in the outer container.

[0044] The battery pack further comprises: an oxygen absorber housed in the outer container or arranged in the circulation path communicating with the outer container, and

[0045] The method further includes removing oxygen within the battery pack by the oxygen absorber.

[0046] <Method 9>

[0047] According to the method described in mode 8,

[0048] The method further includes: performing circulation in the circulation path when one or more values ​​selected from the group consisting of the temperature, the pressure, and the concentration of the hydrogen sulfide of the battery pack reaches or exceeds a threshold value.

[0049] According to the present disclosure, it is possible to provide a battery pack capable of effectively removing hydrogen sulfide generated from a battery containing a sulfide solid electrolyte, and a method for removing such hydrogen sulfide in the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 It is a schematic diagram showing an example of the battery pack of the present disclosure.

[0051] Figure 2 It is a schematic diagram showing an example of the battery pack of the present disclosure.

[0052] Figure 3 It is a schematic diagram showing an example of the battery pack of the present disclosure.

[0053] Figure 4 This is a flowchart showing an example of the method of the present disclosure for removing hydrogen sulfide in a battery pack.

[0054] Figure 5 This is a flowchart showing an example of the method of the present disclosure for removing hydrogen sulfide in a battery pack.

[0055] Figure 6 This is a flowchart showing an example of the method of the present disclosure for removing hydrogen sulfide in a battery pack.

[0056] Figure 7 This is a graph showing the hydrogen sulfide absorption capacity of zinc oxide and limestone according to temperature.

[0057] Description of Reference Numerals

[0058] 1 battery pack

[0059] 10 external containers

[0060] 20 batteries

[0061] 30 flow path

[0062] 31 Exhaust flow path

[0063] 32 loop paths

[0064] 40 Hydrogen sulfide absorbent

[0065] 50 Heater

[0066] 60 oxygen absorber DETAILED DESCRIPTION

[0067] Hereinafter, the embodiments of the present disclosure will be described in detail. Note that the present disclosure is not limited to the following embodiments, and can be implemented with various modifications within the scope of the disclosed gist.

[0068] Hereinafter, the battery pack of the present disclosure will be described with reference to the accompanying drawings. Note that the dimensional relationships in the accompanying drawings do not reflect the actual dimensional relationships.

[0069] Battery Pack

[0070] like Figure 1 As shown, the battery pack 1 of the present disclosure comprises: an outer container 10; a battery 20 contained in the outer container 10 and containing a sulfide solid electrolyte; and a hydrogen sulfide absorbent 40 contained in the outer container 10 or disposed in a flow path 30 communicating with the interior of the outer container 10. The hydrogen sulfide absorbent is selected from zinc oxide, limestone, dolomite, or a combination thereof.

[0071] As described above, in a battery including a sulfide solid electrolyte, the sulfide solid electrolyte and water may react to generate hydrogen sulfide. In addition, when the battery is exposed to abnormal heat, the temperature of the generated hydrogen sulfide becomes high, and thus the high-temperature hydrogen sulfide may be discharged outside the outer container of the battery pack.

[0072] In this regard, the inventors of the present disclosure have found that hydrogen sulfide generated in the outer container can be effectively removed by disposing a hydrogen sulfide absorbent selected from zinc oxide, limestone, dolomite or a combination thereof in the outer container of the battery pack or in a flow path communicating with the outer container.

[0073] like Figure 7 As shown, according to the research results of the present inventors, zinc oxide has a high absorption capacity for hydrogen sulfide in the temperature range of room temperature to 300°C, and limestone and dolomite have a high absorption capacity for hydrogen sulfide at temperatures above 300°C. Therefore, by using these hydrogen sulfide absorbents alone or in combination, the generated hydrogen sulfide can be effectively removed. That is, at a relatively low temperature (temperature range of room temperature to 300°C), hydrogen sulfide can be effectively removed by using zinc oxide. At a relatively high temperature (temperature above 300°C), hydrogen sulfide can be effectively removed by using limestone and / or dolomite. In the temperature range from relatively low temperature to relatively high temperature, hydrogen sulfide can be effectively removed by using zinc oxide and limestone and / or dolomite in combination.

[0074] Hereinafter, each structure of the battery pack of the present disclosure will be described.

[0075] <External container>

[0076] like Figure 1 As shown, in the first embodiment, the battery pack 1 of the present disclosure has an outer container 10. The size and shape of the outer container 10 are not particularly limited, for example, as long as the battery 20 and the hydrogen sulfide absorber 40, and the oxygen absorber that is optionally added can be accommodated, and the flow path 30 can be configured. The material of the outer container is not particularly limited, for example, it can be a metal such as aluminum or stainless steel.

[0077] <Battery>

[0078] like Figure 1 As shown, the battery pack 1 of the present disclosure has a battery 20 contained in an outer container 10 and containing a sulfide solid electrolyte. The battery may contain a sulfide solid electrolyte in the positive electrode active material layer and / or the negative electrode active material layer. In addition, in the case where the battery is a solid battery, the battery may contain a sulfide solid electrolyte in the solid electrolyte layer. That is, the battery 20 may be a sulfide solid battery containing a sulfide solid electrolyte in the solid electrolyte layer. In the present disclosure, the battery may be an electrode of an electrode stack in which layers such as a collector layer, an electrode active material layer, and an electrolyte layer are stacked in a laminated film, i.e., a so-called laminated battery (also called a soft pack battery).

[0079] Furthermore, in the present disclosure, "solid battery" refers to a battery that uses at least a solid electrolyte as an electrolyte, and therefore, a solid battery may also use a combination of a solid electrolyte and a liquid electrolyte as an electrolyte. In addition, the solid battery of the present disclosure may also be an all-solid battery, that is, a battery that uses only a solid electrolyte as an electrolyte.

[0080] The battery disclosed in the present invention may be a lithium ion battery. In this case, examples of sulfide solid electrolytes include, but are not limited to, sulfide amorphous solid electrolytes, sulfide crystalline solid electrolytes, and argyrodite-type solid electrolytes. Specific examples of sulfide solid electrolytes include Li2S-P2S5 (Li7P3S 11 , Li3PS4, Li8P2S9, etc.), Li2S-SiS2, LiI-Li2S-SiS2, LiI-Li2S-P2S5, LiI-LiBr-Li2S-P2S5, Li2S-P2S5-GeS2 (Li 13 GeP3S 16 , Li 10 GeP2S 12 etc.), LiI-Li2S-P2O5, LiI-Li3PO4-P2S5, Li 7-x PS 6-x Cl x etc.; or combinations thereof, but not limited thereto.

[0081] The sulfide solid electrolyte may be glass or crystallized glass (glass ceramic).

[0082] The batteries 20 housed in the outer container 10 are electrically connected in series, in parallel, or in a combination of series and parallel. Figure 1 In the figure, a plurality of batteries 20 are schematically shown, but the number of batteries housed in the outer container 10 may be one. The battery 20 may be in any form known in the art, such as a stacked type or a wound type. When each battery 20 is composed of two or more unit cells, in each battery 20, the unit cells are electrically connected in series, in parallel, or in a combination of series and parallel. Figure 1 In the embodiment, a case where a plurality of batteries are arranged in parallel in the outer container 10 is schematically illustrated, but the arrangement of the batteries in the outer container 10 is not particularly limited and may be any arrangement. Therefore, the plurality of batteries 20 may be stacked on each other or may be arranged separately from each other.

[0083] <Hydrogen sulfide absorbent>

[0084] like Figure 1As shown, the battery pack 1 of the present disclosure includes a hydrogen sulfide absorbent 40 , and the hydrogen sulfide absorbent 40 is accommodated in an outer container 10 or is disposed in a flow path 30 communicating with the interior of the outer container 10 . Figure 1 , the hydrogen sulfide absorbent 40 is arranged in the flow path 30 , but as described above, the hydrogen sulfide absorbent 40 may be accommodated in the outer container 10 .

[0085] The hydrogen sulfide absorbent is selected from zinc oxide, limestone, dolomite or a combination thereof. As described above, zinc oxide has a high absorption capacity for hydrogen sulfide at a temperature between room temperature and 300° C., and limestone and dolomite have a high absorption capacity for hydrogen sulfide at a temperature above 300° C. Therefore, by using these hydrogen sulfide absorbents alone or in combination, the generated hydrogen sulfide can be effectively removed.

[0086] <Heater>

[0087] like Figure 2 As shown, the battery pack 1 of the present disclosure may further include a heater 50 for heating the hydrogen sulfide absorbent 40. By adopting such a structure, it is possible to promote the absorption of hydrogen sulfide by limestone and dolomite as hydrogen sulfide absorbents operating at relatively high temperatures.

[0088] The power source of the heater may be a battery housed in the outer container. Thus, when hydrogen sulfide is generated, the SOC (State Of Charge) of the battery housed in the outer container can be reduced.

[0089] The above is the first embodiment of the battery pack of the present disclosure.

[0090] <Flow path>

[0091] In the second embodiment, the flow path 30 may be a gas exhaust flow path 31 for exhausting the gas in the outer container 10 to the outside of the outer container 10. That is, in this embodiment, the battery pack 1 may not be sealed.

[0092] In the third embodiment, the flow path 30 may be a circulation path 32 for circulating the gas in the outer container 10. That is, in this embodiment, the battery pack 1 may also be sealed. When an oxygen absorber described later is used, the absorption of oxygen by the oxygen absorber is promoted by circulating the gas in the outer container 10.

[0093] <Oxygen absorber>

[0094] like Figure 3 As shown, in the third embodiment, the battery pack 1 of the present disclosure may further include an oxygen absorber 60 , and the oxygen absorber 60 is accommodated in the outer container 10 or is disposed in the circulation path 32 communicating with the outer container 10 . Figure 3, the oxygen absorber 60 is arranged in the circulation path 32 , but as described above, the oxygen absorber 60 may be accommodated in the outer container 10 .

[0095] The oxygen absorber is not particularly limited as long as it is a material that can absorb oxygen. The oxygen absorber may be a material that can absorb oxygen by reacting with oxygen, that is, by being oxidized. Examples of such materials include metals such as iron, and organic compounds such as vitamin C. In addition, the oxygen absorber may be a material that can absorb oxygen by being oxidized at a temperature above 100°C. Examples of such materials include paraffin. For example, when the hydrogen sulfide absorber is in powder form, the paraffin can not only absorb oxygen at a predetermined temperature, but also act as a binder for the hydrogen sulfide absorber.

[0096] 《Method for removing hydrogen sulfide in battery pack》

[0097] In a first embodiment, the method of the present disclosure for removing hydrogen sulfide in a battery pack comprises: removing hydrogen sulfide in the battery pack by a hydrogen sulfide absorbent, wherein the battery pack comprises: an outer container, a battery contained in the outer container and comprising a sulfide solid electrolyte, and the hydrogen sulfide absorbent contained in the outer container or arranged in a flow path connected to the outer container, wherein the hydrogen sulfide absorbent is selected from zinc oxide, limestone, dolomite, or a combination thereof.

[0098] For the battery pack in the method of the present disclosure, reference may be made to the above description about the battery pack of the present disclosure.

[0099] The method disclosed herein comprises removing hydrogen sulfide by a hydrogen sulfide absorbent selected from zinc oxide, limestone, dolomite or a combination thereof. By adopting this method, as described above, hydrogen sulfide generated in the outer container can be effectively removed.

[0100] The battery pack may further include a heater for heating the hydrogen sulfide absorbent.

[0101] The power source of the heater may be a battery housed in the outer container.

[0102] Regarding the heater and its power supply, reference may be made to the above description regarding the battery pack of the present disclosure.

[0103] The method of the present disclosure may further include: heating the hydrogen sulfide absorbent by a heater when one or more values ​​selected from the group consisting of the temperature, pressure, and hydrogen sulfide concentration of the battery pack reaches or exceeds a threshold value.

[0104] In the present disclosure, "battery pack temperature" may be the temperature inside the outer container, the temperature of the battery, the temperature inside the flow path, etc. "battery pack pressure" may be the pressure inside the outer container, the pressure inside the flow path, etc. "Battery pack hydrogen sulfide concentration" may be the hydrogen sulfide concentration inside the outer container, the hydrogen sulfide concentration inside the flow path, etc.

[0105] There is no particular limitation on the method of measuring the temperature of the battery pack, and an example thereof includes a method of measuring by a heat detection unit such as a temperature sensor. There is no particular limitation on the method of measuring the pressure of the battery pack, and an example thereof includes a method of measuring by a pressure detection unit such as a pressure sensor. There is no particular limitation on the method of measuring the hydrogen sulfide concentration of the battery pack, and an example thereof includes a method of measuring by a hydrogen sulfide concentration detection unit such as a hydrogen sulfide concentration sensor. The temperature, pressure, and hydrogen sulfide concentration of the battery pack can be constantly monitored by, for example, the above-mentioned sensors.

[0106] The threshold value of the battery pack temperature is not particularly limited, and may be, for example, a value that can be determined as a temperature that causes the generation of hydrogen sulfide. Furthermore, when the battery pack temperature is a temperature above the temperature at which limestone and dolomite effectively function as hydrogen sulfide absorbers, for example, a temperature above 300° C., heating by the heater may not be performed.

[0107] The threshold value of the battery pack pressure is not particularly limited, and may be, for example, a value that can be determined as a pressure increase associated with the generation of hydrogen sulfide.

[0108] The hydrogen sulfide concentration threshold value of the battery pack is not particularly limited, and may be, for example, a measurable value as a concentration of hydrogen sulfide indicating the generation of hydrogen sulfide.

[0109] As described above, since the heater is used to heat the hydrogen sulfide absorbent, ie, limestone and dolomite, which operate particularly at a relatively high temperature, the heating temperature of the heater may be determined in consideration of the temperature at which the limestone and dolomite effectively operate as the hydrogen sulfide absorbent.

[0110] The above is the first embodiment of the method of the present disclosure.

[0111] In a second embodiment, the flow path may be an exhaust flow path that discharges the gas in the outer container to the outside of the outer container, and the hydrogen sulfide absorber is arranged in the exhaust flow path. In this case, the method disclosed herein may further include: exhausting the gas from the exhaust flow path when the temperature of the hydrogen sulfide absorber reaches or exceeds a threshold value. The temperature threshold of the hydrogen sulfide absorber can be appropriately designed based on the temperature at which the hydrogen sulfide absorber effectively functions. That is, in the case where the hydrogen sulfide absorber is zinc oxide, the above threshold can be made a lower temperature, and in the case where the hydrogen sulfide absorber is limestone or dolomite, the above threshold can be made a higher temperature. By adopting this method, the gas can be exhausted from the exhaust flow path at a temperature at which the hydrogen sulfide absorber effectively functions, thereby suppressing the hydrogen sulfide from being discharged to the outside of the outer container.

[0112] The method for measuring the temperature of the hydrogen sulfide absorbent is not particularly limited, and an example thereof includes a method of measuring with a heat detection unit such as a temperature sensor.

[0113] In a third embodiment, the flow path may be a circulation path for circulating the gas in the outer container, and the battery pack may further include an oxygen absorber, which is contained in the outer container or arranged in the circulation path connected to the outer container. In this case, the method of the present disclosure may further include removing oxygen in the battery pack by the oxygen absorber.

[0114] In a third embodiment, the method of the present disclosure may further include: when one or more values ​​selected from the temperature, pressure and hydrogen sulfide concentration of the battery pack reaches or exceeds a threshold value, circulating in the circulation path. By adopting this method, the energy required for circulation can be reduced compared to the case where the gas in the outer container is always circulated.

[0115] In the method disclosed herein, the battery pack may have a control unit. The control unit may be connected to the heat detection unit, the pressure detection unit, and the hydrogen sulfide concentration detection unit, respectively. Thus, the control unit can operate the heater when one or more values ​​selected from the temperature, pressure, and concentration of hydrogen sulfide of the battery pack reach or exceed a threshold value. In addition, the control unit can exhaust gas from the exhaust flow path when the temperature of the hydrogen sulfide absorbent reaches or exceeds a threshold value. Moreover, the control unit can circulate in the circulation path when the temperature, pressure, and concentration of hydrogen sulfide of the battery pack reach or exceed a threshold value.

[0116] Below, refer to Figures 4 to 6 The method of the present disclosure for removing hydrogen sulfide in a battery pack will be described.

[0117] Figure 4The present invention is a flowchart showing an example of a first embodiment of the method of removing hydrogen sulfide in a battery pack. In the first embodiment, the flow path of the battery pack may be an exhaust flow path or a circulation path. In addition, the battery pack may or may not have an oxygen absorber in addition to the hydrogen sulfide absorber.

[0118] like Figure 4 As shown, in the first embodiment, first, at the start, one or more values ​​selected from the temperature, pressure and hydrogen sulfide concentration of the battery pack are monitored by the heat detection unit, the pressure detection unit or the hydrogen sulfide concentration detection unit.

[0119] Next, the control unit compares the temperature, pressure, and hydrogen sulfide concentration of the battery pack transmitted from each detection unit with respective threshold values ​​(step S101). Here, when all values ​​selected from the temperature, pressure, and hydrogen sulfide concentration of the battery pack are less than the threshold value, the monitoring of each detection unit is continued.

[0120] On the other hand, when one or more values ​​selected from the battery pack temperature, pressure, and hydrogen sulfide concentration are equal to or higher than the threshold value, the control unit operates the heater for heating the hydrogen sulfide absorbent (step S102 ).

[0121] Figure 5 1 is a flow chart showing an example of a second embodiment of the method of the present disclosure for removing hydrogen sulfide in a battery pack. In the second embodiment, the flow path of the battery pack is an exhaust flow path.

[0122] like Figure 5 As shown, in the second embodiment, the process from the beginning to step S202 is the same as the process from the beginning to step S102 in the first embodiment.

[0123] After step S202, the control unit compares the temperature of the hydrogen sulfide absorbent sent from the heat detection unit with a threshold value (step S203). Here, when the temperature of the hydrogen sulfide absorbent is lower than the threshold value, the heater continues to heat the hydrogen sulfide absorbent.

[0124] On the other hand, when the temperature of the hydrogen sulfide absorbent is equal to or higher than the threshold value, the control unit performs exhaust from the exhaust flow path (step S204).

[0125] Figure 6 This is a flow chart showing an example of a third embodiment of the method of the present disclosure for removing hydrogen sulfide in a battery pack. In the third embodiment, the flow path of the battery pack is a circulation path, and the battery pack has an oxygen absorber in addition to the hydrogen sulfide absorber.

[0126] like Figure 6As shown, in the third embodiment, the start and step S301 are the same as the start and step S101 in the first embodiment.

[0127] In step S301 , when one or more values ​​selected from the battery pack temperature, pressure, and hydrogen sulfide concentration are equal to or higher than a threshold value, the control unit operates a heater for heating the hydrogen sulfide absorbent and performs circulation in the circulation path (step S302 ).

Claims

1. A battery pack having: external container; a battery contained in the outer container and containing a sulfide solid electrolyte; and a hydrogen sulfide absorbent contained in the outer container or disposed in a flow path communicating with the outer container, and The hydrogen sulfide absorbent is selected from zinc oxide, limestone, dolomite or a combination thereof. 2 . The battery pack according to claim 1 , further comprising a heater for heating the hydrogen sulfide absorbent. The battery pack according to claim 2 , wherein the power source of the heater is the battery.

4. The battery pack according to any one of claims 1 to 3, The flow path is a circulation path for circulating the gas in the outer container. The battery pack further includes an oxygen absorber housed in the outer container or disposed in a circulation path communicating with the outer container.

5. A method for removing hydrogen sulfide, which is a method for removing hydrogen sulfide in a battery pack. The battery pack has: external container; a battery contained in the outer container and containing a sulfide solid electrolyte; and a hydrogen sulfide absorbent contained in the outer container or disposed in a flow path communicating with the outer container, The hydrogen sulfide absorbent is selected from zinc oxide, limestone, dolomite or a combination thereof, and The method comprises removing the hydrogen sulfide by the hydrogen sulfide absorbent.

6. The method for removing hydrogen sulfide according to claim 5, The battery pack further comprises a heater for heating the hydrogen sulfide absorbent. The method further includes heating the hydrogen sulfide absorbent by the heater when one or more values ​​selected from the group consisting of the temperature, the pressure, and the concentration of the hydrogen sulfide of the battery pack reaches or exceeds a threshold value.

7. The method for removing hydrogen sulfide according to claim 5 or 6, The flow path is an exhaust flow path for exhausting the gas in the outer container to the outside of the outer container. The hydrogen sulfide absorbent is disposed in the exhaust gas flow path, and The method further includes exhausting the hydrogen sulfide absorbent from the exhaust flow path when the temperature of the hydrogen sulfide absorbent reaches or exceeds a threshold value.

8. The method for removing hydrogen sulfide according to claim 5 or 6, The flow path is a circulation path for circulating the gas in the outer container. The battery pack further comprises: an oxygen absorber housed in the outer container or arranged in the circulation path communicating with the outer container, and The method further includes removing oxygen within the battery pack by the oxygen absorber. 9 . The method for removing hydrogen sulfide according to claim 8 , further comprising: performing circulation in the circulation path when one or more values ​​selected from the group consisting of the temperature, the pressure of the battery pack and the concentration of the hydrogen sulfide reaches or exceeds a threshold value.

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