Hydrogen sulfide detection device

Abstract

A hydrogen sulfide detection device comprises a wire electrically connecting a first node and a second node, and a monitoring circuit that monitors the voltage between the first and second nodes. The wire contains a variety of metallic exposed sections where a metal that reacts with the hydrogen sulfide by corrosion is exposed.

Description

BACKGROUND OF THE INVENTION 1. Field of the invention

[0001] The present disclosure relates to a device for detecting hydrogen sulfide (hydrogen sulfide detection device) that can be applied to a battery pack / battery assembly containing a battery cell with a sulfide-based electrolyte. 2. Description of the related prior art

[0002] Solid-state batteries are attracting attention as the next generation of battery cells used to configure battery packs. Compared to conventional batteries with liquid electrolytes, solid-state batteries offer the advantages of high safety and a long lifespan. Solid-state batteries with a sulfide-based electrolyte offer high capacity and performance and are expected to be used in vehicle batteries.

[0003] If the battery cell containing the sulfide-based electrolyte is configured as a solid-state battery cell, a failure can cause the formation of hydrogen sulfide gas. Hydrogen sulfide gas is toxic and corrodes surrounding metal components. Therefore, there is a need for a technology to adequately detect hydrogen sulfide formation in the battery pack / assembly containing the sulfide-based electrolyte cell.

[0004] The unexamined Japanese patent application disclosure no. 2017-199667 (JP 2017-199667 A) discloses a detection system in which a resistance-changing element, containing a resistance-changing material whose electrical resistance is modified by a chemical reaction with hydrogen sulfide, is provided in a battery cell, and in which, based on a detection value between terminals of the resistance-changing element, it is determined whether or not hydrogen sulfide is being generated in the battery cell. Additionally, WO 2003 / 029801 is cited as a document representing the state of the art. BRIEF SUMMARY OF THE INVENTION

[0005] In a solid-state battery cell with a sulfide-based electrolyte, it is extremely difficult to predict the amount of hydrogen sulfide produced. Furthermore, it is also difficult to predict how the generated hydrogen sulfide will distribute. Therefore, to detect hydrogen sulfide production effectively, it is desirable to perform detection at numerous points within the battery pack.

[0006] However, in the technology disclosed in JP 2017-199667 A, a detection circuit is configured for each resistance-changing element. Therefore, the detection circuit becomes complex when resistance-changing elements are located in numerous sections of the battery pack. Consequently, the cost increase becomes a problem when detection is performed in many sections of the battery pack. Furthermore, the space required for configuring the detection system also increases.

[0007] The present disclosure was made with regard to the problems mentioned above. The present disclosure aims to provide a technology capable of detecting the generation of hydrogen sulfide at a variety of sections within a battery pack, while simultaneously reducing costs.

[0008] One aspect of the present disclosure relates to a device for detecting or sensing hydrogen sulfide (hydrogen sulfide detection device) that can be used in a battery pack / consumer assembly / battery pack containing a battery cell with a sulfide-based electrolyte. The hydrogen sulfide detection device comprises a wire electrically connecting a first node and a second node, and a monitoring circuit that monitors a voltage between the first node and the second node. The wire contains a plurality of metallic exposed sections in which a metal that reacts with hydrogen sulfide under corrosion is exposed.

[0009] In the present disclosure, the exposed metallic parts are arranged on a plurality of parts of the battery pack, so that the generation of hydrogen sulfide can be detected on a plurality of parts of the battery pack. Furthermore, in the present disclosure, the hydrogen sulfide detection device consists only of the monitoring circuit and a wire, regardless of the number of detection sections, thereby reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Features, advantages and technical and industrial significance of embodiments of the invention are described below with reference to the accompanying drawings, in which the same symbols denote the same elements and in which: Fig. Figure 1 is a schematic diagram showing the configuration of a device for detecting hydrogen sulfide according to a first embodiment; Fig. Figure 2A is an explanatory schematic diagram showing the operation of the device for detecting hydrogen sulfide; Fig. Figure 2B is an explanatory schematic diagram showing the operation of the device for detecting hydrogen sulfide; Fig. Figure 3 is a flowchart illustrating the process carried out by a monitoring circuit; Fig. Figure 4 is a conceptual diagram showing an example of the arrangement of the exposed metal parts; Fig. Figure 5 is a schematic diagram showing the configuration of a device for detecting hydrogen sulfide according to a second embodiment; and Fig. Figure 6 is a schematic diagram showing a configuration of a device for detecting hydrogen sulfide according to a third embodiment. DETAILED DESCRIPTION OF THE EXECUTION EXAMPLES

[0011] Exemplary embodiments of the present disclosure are described below with reference to the accompanying drawings. It should be noted that identical or corresponding configurations in each figure are identified by the same reference symbols, and their descriptions are simplified or omitted. 1 First Implementation Example 1.1 Configuration

[0012] Fig. Figure 1 is a schematic diagram showing a configuration of a device (hydrogen sulfide detection device) 10 for detecting hydrogen sulfide according to a first embodiment. The hydrogen sulfide detection device 10 is attached to a battery pack containing a battery cell with a sulfide-based electrolyte and detects the formation of hydrogen sulfide. The hydrogen sulfide detection device 10 is stored together with the battery cell in the battery pack. The battery cell with the sulfide-based electrolyte is typically a solid-state battery using a solid sulfide-based electrolyte. The type of battery cell is not particularly restricted. For example, the battery cell can be laminated or prismatic. The solid-state battery using the sulfide-based electrolyte has a large capacity and high power output and is suitable for use as a vehicle battery.Therefore, the battery in which the device for detecting hydrogen sulfide 10 is used can in particular be a vehicle battery.

[0013] The device 10 for detecting hydrogen sulfide comprises a monitoring circuit 100 and a plurality of substrates 200. The substrates 200 are printed circuit boards (PCBs) of the same pattern 220, made of a metal. Each of the substrates 200 can, in particular, be a flexible printed circuit (FPC).

[0014] The monitoring circuit 100 is connected to an external device via a terminal 110, and the substrates 200 are each connected to an external device via a terminal 210. As shown in Fig. As shown in Figure 1, the monitoring circuit 100 and the substrates 200 are connected in series via a cable 300. In this way, the cable 300 and the pattern 220 of each of the substrates 200 form a wire that electrically connects a first node 401 and a second node 402 (hereinafter simply referred to as the "wire"). The wire forms a current path.

[0015] The monitoring circuit 100 monitors a voltage between the first node 401 and the second node 402. In the monitoring circuit 100, the first node 401 is connected via a resistor 120 to a power supply with a voltage Vcc (e.g., 5 V), and the second node 402 is connected to a ground GND, which has a reference potential (e.g., 0 V). The monitoring circuit 100 includes a monitoring processing unit 130. The monitoring processing unit 130 is a computer that performs the processing of the voltage monitoring. The monitoring processing unit 130 can, in particular, be a microcontroller. The monitoring processing unit 130 is configured to receive a potential between the resistor 120 and the first node 401 as its input.If the monitoring processing unit 130 is, for example, a microcontroller, one input pin of the microcontroller is connected between resistor 120 and the first node 401. Resistor 120 is a pull-up resistor for the monitoring processing unit 130. The resistance value of resistor 120 is, for example, approximately 10 kΩ. The second node 402 is connected to ground (GND), and therefore the monitoring processing unit 130 can detect the voltage between the first node 401 and the second node 402.

[0016] It should be noted that the voltage between the first node 401 and the second node 402 can also be indirectly detected by measuring the voltage at both ends of the resistor 120. Therefore, monitoring the voltage between the first node 401 and the second node 402 involves measuring the voltage at both ends of the resistor 120. From this perspective, the monitoring processing unit 130 can be arranged to measure the voltage at both ends of the resistor 120.

[0017] The monitoring processing unit 130 comprises one or more processors 131 (hereinafter referred to simply as "processor 131") and one or more devices 132 (hereinafter referred to simply as "storage device 132"). The processor 131 performs various types of processing. Examples of the processor 131 include a general-purpose processor, a special-purpose processor, a central processing unit (CPU), a graphics processing unit (GPU), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), an integrated circuit, a conventional circuit, and one or more combinations thereof. The processor 131 can also be referred to as a processing circuit. The storage device 132 stores various types of information required for the processor 131 to perform processing.Examples of the storage device 132 include recording media such as random-access memory (RAM), read-only memory (ROM), a solid-state drive (SSD), and a hard disk drive (HDD). The device 132 stores a computer program that can be executed by the processor 131. The computer program consists of a variety of instruction codes that describe the processing to be performed by the processor 131. The computer program is stored on a computer-readable recording medium. The functions of the monitoring processing unit 130 are realized through the cooperation between the device 132 and the processor 131, which executes the computer program.

[0018] The metal forming the pattern 220 of the substrate 200 is one that reacts with and corrodes in hydrogen sulfide. For example, copper or silver is used. Furthermore, in the first embodiment, a portion of the pattern 220 of each of the substrates 200 forms a metal-exposed section 500 by exposing the metal to the surface of the substrate 200. This condition can be achieved by configuring the substrate 200 such that surface protection (e.g., solder mask or topcoat) or surface treatment (e.g., plating) is prevented in that portion of the pattern 220. As described above, in the first embodiment, a portion of the pattern 220 of each of the substrates 200 forms the exposed metallic section 500. In this way, the wire contains, as in Fig. 1 shown, a multitude of metallically exposed sections 500. 1.2 Functioning of the device for detecting hydrogen sulfide

[0019] The following describes the operation of the device 10 for detecting hydrogen sulfide according to the first embodiment.

[0020] Fig. 2A and Fig. 2B are explanatory schematic diagrams illustrating the operation of the device 10 for the detection of hydrogen sulfide.

[0021] Fig. Figure 2A illustrates an operation where the target battery is functioning normally. That is, Fig. 2A shows an operating mode in which no hydrogen sulfide is produced by the battery cell. When the battery pack is functioning normally, the wire is simply a current path without resistance. Therefore, as shown in transmission path TR, the ground potential (GND) is directly fed into monitoring unit 130. That is, monitoring processing unit 130 detects the reference potential as its detection value.

[0022] Fig. Figure 2B illustrates a process in which hydrogen sulfide is generated from the battery cell. At this point, the metal of the exposed metal part 500 reacts with the generated hydrogen sulfide and corrodes. As the metal becomes a sulfide through corrosion, the resistance of the metallic area 500 increases. Furthermore, the metal tends to move radially due to corrosion. The corroded metal also moves when subjected to vibrations. For example, when vibrations from the vehicle are transmitted, the corroded metal moves. As the corrosion progresses as described above, the metal of the exposed metal part 500 gradually disappears, reducing its cross-sectional area. In this way, the resistance of the exposed metal part 500 continues to increase. Eventually, the metal of the exposed part 500 is degraded.

[0023] As described above, the resistance of the metallic part 500 gradually increases as hydrogen sulfide is generated by the battery cell, and the metallic part 500 eventually switches off. Therefore, during this process of the increasing resistance of the metallic part 500, the monitoring processing unit 130 detects a voltage difference caused by this resistance as its detection value. That is, as the resistance of the exposed metallic part 500 increases, the detection value of the monitoring unit 130 rises relative to the reference potential. When the metallic part 500 is finally disconnected, the power supply voltage Vcc is directly input to the monitoring processing unit 130. Thus, the monitoring processing unit 130 detects the power supply voltage Vcc as its detection value.

[0024] Fig. Figure 2B shows a diagram illustrating an example of the detection value of monitoring unit 130 when the reference potential is 0 V. As shown in the diagram, the detection value of monitoring unit 130 changes from 0 V to Vcc when hydrogen sulfide is generated by the battery cell. Thus, monitoring unit 130 can determine whether or not hydrogen sulfide is being generated by the battery cell based on the detection value (the voltage between the first node 401 and the second node 402). For example, monitoring unit 130 determines that hydrogen sulfide is being generated by the battery cell when the deviation from an initial detection value exceeds a threshold.Furthermore, the monitoring processing unit 130 can, for example, determine that the hydrogen sulfide is being produced by the battery cell without calculating the deviation amount of the detection value, but directly using the detection value, in response to the fact that the detection value has become greater than a threshold.

[0025] Fig. Figure 3 is a flowchart showing the processing sequence performed by monitoring circuit 100 (more precisely, monitoring processing unit 130). The Fig. The processing sequence shown in Figure 3 is executed repeatedly for each predetermined processing period.

[0026] First, in step S110, the monitoring circuit 100 acquires the detection value. Next, in step S120, the monitoring circuit 100 calculates the magnitude of the deviation from the initial value of the detection value. In the hydrogen sulfide detection device 10, the initial value of the detection value is the reference potential, and the magnitude of the deviation from the initial value is the difference between the detection value and the reference potential. Specifically, if the reference potential is 0 V, the magnitude of the deviation from the initial value coincides with the detection value. Next, in step S130, the monitoring circuit 100 determines whether the calculated magnitude of the deviation is greater than a threshold value.

[0027] If the deviation is equal to or less than the threshold (step S130; No), the monitoring circuit 100 detects that no hydrogen sulfide is being generated and terminates processing for that time. If the deviation is greater than the threshold (step S130; Yes), the monitoring circuit 100 detects that hydrogen sulfide is being generated by the battery cell (step S140). The monitoring circuit 100 can also issue a warning to the user about the generation of hydrogen sulfide by visual or audible signal. 1.3 Effects

[0028] As described above, the hydrogen sulfide detection device 10, according to the first embodiment, can detect the generation of hydrogen sulfide from the battery cell. Specifically, the hydrogen sulfide detection device 10 detects the generation of hydrogen sulfide when the metal of one of the metallic parts 500 reacts with the hydrogen sulfide. That is, the hydrogen sulfide detection device 10 can detect the formation of hydrogen sulfide at a plurality of sections in the battery pack by arranging the metallically exposed sections 500 at a plurality of sections in the battery pack. Furthermore, the hydrogen sulfide detection device 10 consists of a monitoring circuit 100 and a wire that serves as a current path, regardless of the number of detection sections.In particular, the hydrogen sulfide detection device 10 can be achieved by using only one input terminal of the monitoring processing unit 130 of the monitoring circuit 100. As described above, the hydrogen sulfide detection device 10 can be configured cost-effectively and in a space-saving manner without complicating the circuit, even when the number of detection sections is increased. Furthermore, compared to the case where the detection value is taken between the terminals of the battery cell when the circuit is not electrically connected to the battery cell, the circuit configuration can be simplified, and the number of detection sections can be easily increased.

[0029] According to the first embodiment, the metal-exposed part 500 is formed by the pattern 220 of the substrate 200. The pattern 220 of the substrate 200 can be very thin. For example, the pattern 220 can be formed with a thickness of approximately 50 µm. If the metal-exposed section 500 is formed with such a pattern 220, the rate of corrosion can be increased when the metal of the metal-exposed section 500 reacts with hydrogen sulfide. That is, when the hydrogen sulfide is generated by the battery cell, the metal of the exposed metal part 500 disappears quickly and can be easily removed. As a result, the detection accuracy of the device 10 for detecting hydrogen sulfide can be improved.Furthermore, the device 10 can be configured for the detection of hydrogen sulfide by reusing an existing substrate used for voltage monitoring of the battery cell or similar. This can further reduce costs.

[0030] According to the first embodiment, the hydrogen sulfide detection device 10 also comprises substrates 200 corresponding to the respective metallic areas 500. Each of the metal-exposed sections 500 is formed by the pattern 220 of the corresponding substrate 200 from the substrates 200. In other words, the metal-exposed sections 500 are formed by the respective patterns 220 of the individual substrates 200. Furthermore, the substrates 200 are connected in series by the cable 300. In this way, the metal-exposed parts 500 can be individually positioned at the desired locations within the battery pack. Thus, the hydrogen sulfide detection device 10 can be designed with a high degree of freedom in the arrangement of the detection element.

[0031] It is quite possible that the location in the battery cell where the hydrogen sulfide is to be generated is a sealing section of an outer part of the battery cell. This is because the sealing section is likely to have lower scratch resistance than other parts. Considering the above, the exposed metal sections 500 could include an exposed metal section 500 located adjacent to the sealing section of the outer element of the battery cell.

[0032] Fig. Figure 4 is a conceptual diagram showing an example of the arrangement of the exposed metal parts 500. Fig. Figure 4 shows a schematic representation of a battery cell 20. If the battery cell 20 is of the laminated type, an outer element 21 of the battery cell 20 is typically a laminate film. If the battery cell 20 is of the prismatic type, the outer element 21 of the battery cell 20 is typically a metal can. In the Fig. In the example shown in Figure 4, a sealing section 22 of the outer element 21 is positioned to cover an electrode terminal 23 of the battery cell 20. Furthermore, the substrate 200 is located adjacent to the sealing section 22 of the outer element 21. As described above, the exposed metal section 500 is located adjacent to the sealing section 22 of the outer element 21 of the battery cell 20.

[0033] As described above, the detection accuracy of the device 10 for detecting hydrogen sulfide can be improved if the exposed metal section 500 is positioned next to the sealing section 22 of the outer element 21 of the battery cell 20. 1.4 Example of a modification

[0034] In the first embodiment described above, the monitoring circuit 100 is configured such that resistor 120 acts as a pull-up resistor for the monitoring processing unit 130. As a modification, the monitoring circuit 100 can be configured such that resistor 120 acts as a pull-down resistor for the monitoring processing unit 130. That is, the first node 401 can be directly connected to the power supply, and the second node 402 can be connected to ground (GND) via resistor 120. Furthermore, the monitoring processing unit 130 can be arranged to detect the voltage between the first node 401 and the second node 402. For example, the input terminal of the monitoring processing unit 130 is connected between resistor 120 and the second node 402.

[0035] In the device 10 for detecting hydrogen sulfide according to the modification example, the voltage Vcc of the power supply is directly input to the monitoring unit 130 at normal times. That is, the monitoring processing unit 130 detects the voltage Vcc as a detection value. If hydrogen sulfide is then generated from the battery cell, the resistance value of the metallic part 500 increases, similar to the process mentioned above, and the metallic part 500 is eventually switched off. In this way, the detection value of the monitoring processing unit 130 changes from Vcc to 0 V. Thus, in the modification example as well, the monitoring processing unit 130 can determine, based on the detection value, whether or not hydrogen sulfide is being generated from the battery cell. The processing sequence of the operation performed by the monitoring circuit 100 at this time can be the same as that described in the modification example. Fig. Figure 3. In the device 10 for detecting hydrogen sulfide according to the modification example, the initial value of the detection value is the voltage Vcc of the power supply, and the amount of the deviation from the initial value is a difference between the detection value and Vcc.

[0036] As described above, similar effects to those mentioned above can also be achieved with the device 10 for the detection of hydrogen sulfide according to the amendment example. 2 Second embodiment

[0037] A second embodiment is described below. It should be noted that the following mainly describes the difference from the first embodiment, and descriptions of content that overlaps with the first embodiment are omitted where applicable.

[0038] Fig. Figure 5 is a schematic diagram showing the configuration of the device 10 for detecting hydrogen sulfide according to the second embodiment. The device 10 for detecting hydrogen sulfide according to the second embodiment includes the monitoring circuit 100 similar to that in the first embodiment. In contrast to the first embodiment, the device 10 for detecting hydrogen sulfide in the second embodiment contains only one substrate 200. The monitoring circuit 100 and the substrate 200 are directly connected to each other via the terminals 110 and 210. In the second embodiment, the pattern 220 of the substrate 200 forms the wire that electrically connects the first node 401 and the second node 402.

[0039] In the second embodiment, the pattern 220 of the substrate 200 forms the metallic sections 500 in which metal is exposed from the surface of the substrate 200 in a plurality of sections. In this way, the wire contains, as in Fig. 5 shown, the exposed metal sections 500.

[0040] The operating principle of the device 10 for detecting hydrogen sulfide according to the second embodiment is the same as that of the first embodiment. Thus, the hydrogen sulfide detection device 10 according to the second embodiment can detect the generation of hydrogen sulfide at a plurality of sections in the battery pack by arranging the metallically exposed sections 500 at a plurality of sections in the battery pack, similar to the first embodiment. Furthermore, the device 10 for detecting hydrogen sulfide according to the second embodiment can be configured cost-effectively and in a space-saving manner without complicating the circuit, even if the number of detection sections is increased, similar to the first embodiment.

[0041] In the hydrogen sulfide detection device 10 according to the second embodiment, the metallic exposed parts 500 are formed by the pattern 220 of the same substrate 200, and therefore the degree of freedom in the arrangement of the detection part is less than in the first embodiment. Meanwhile, the hydrogen sulfide detection device 10 according to the second embodiment can be configured from a single substrate 200, and no cable 300 is required for the connection. Thus, the costs can be reduced compared to the first embodiment. 3 Third example

[0042] A third embodiment is described below. It should be noted that the following mainly describes the difference from the first embodiment, and descriptions of content that overlaps with the first embodiment are omitted where applicable.

[0043] Fig. Figure 6 is a schematic diagram showing the configuration of the device 10 for detecting hydrogen sulfide according to the third embodiment. The device 10 for detecting hydrogen sulfide according to the third embodiment comprises the monitoring circuit 100 similar to that in the first embodiment. In contrast to the first embodiment, the device 10 for detecting hydrogen sulfide in the third embodiment does not include a substrate 200. Instead of the substrate 200, both ends of the single cable 300 are connected to the terminal 110 of the monitoring circuit 100. In the third embodiment, the cable 300 forms the conductor that electrically connects the first node 401 and the second node 402.

[0044] In the third embodiment, the metal used for the cable 300 is one that reacts with and corrodes with hydrogen sulfide. Furthermore, the cable 300 contains metal-exposed sections 500 in which the metal is exposed to the outside of the cable 300 at a plurality of sections. This condition can be achieved by peeling back the sheathing of the cable 300 at a plurality of sections. In this way, the wire contains, as in Fig. Figure 6 shows the exposed metal sections 500.

[0045] The operating principle of the device 10 for detecting hydrogen sulfide according to the third embodiment is the same as that of the first embodiment. Thus, the hydrogen sulfide detection device 10 according to the third embodiment can detect the generation of hydrogen sulfide at a plurality of sections in the battery pack by arranging the exposed metallic sections 500 at a plurality of sections in the battery pack, similar to the first embodiment. Furthermore, the device 10 for detecting hydrogen sulfide according to the third embodiment can be configured cost-effectively and in a space-saving manner without complicating the circuit, even if the number of detection sections is increased, similar to the first embodiment.

[0046] In the hydrogen sulfide detection device 10 according to the third embodiment, the metallic exposed part 500 cannot be made very thin, unlike the substrate 200 in the sample 220, and therefore the detection accuracy is reduced compared to the first embodiment. However, the hydrogen sulfide detection device 10 according to the third embodiment can be easily configured from a single cable 300 without requiring a design for the substrate 200, as in the first embodiment. Furthermore, the costs can be reduced. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 2017-199667

[0004] JP 2017-199667 A [0004, 0006] WO 2003 / 029801

[0004]

Claims

[1] Hydrogen sulfide detection device used in a battery pack accommodating a battery cell having a sulfide-based electrolyte, wherein the hydrogen sulfide detection device comprises: a wire that electrically connects a first node and a second node; and a monitoring circuit that monitors an electrical voltage between the first node and the second node, wherein: The wire comprises a multitude of exposed metal sections where a metal is exposed that reacts with the hydrogen sulfide to corrode. [2] Hydrogen sulfide detection device according to claim 1, wherein the exposed metal sections comprise a pattern of at least one substrate. [3] Hydrogen sulfide detection device according to claim 2, wherein: that at least one substrate comprises a multitude of substrates corresponding to the respective exposed metal sections; and The exposed metal sections each have the pattern of a corresponding substrate from the substrates. [4] Hydrogen sulfide detection device according to claim 1, wherein the exposed metal sections comprise an exposed metal section that is arranged adjacent to a sealing section of an outer element of the battery cell. [5] Hydrogen sulfide detection device according to any one of claims 1 to 4, wherein the monitoring circuit determines whether the hydrogen sulfide is generated by the battery cell on the basis of a change in electrical voltage or not.

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