JP2019109990A - Inspection device - Google Patents

Abstract

To provide an inspection device that can detect a leakage of an electrolyte which can reduce the possibility that a conductive member is damaged or disconnected.SOLUTION: An inspection device 30 is for detecting a leakage of the electrolyte in a power storage module. The inspection device includes: a substrate 31; conductive members 32 and 33 on the substrate 31; a solid electrolyte body 39 in contact with the conductive members 32 and 33; and a detector for applying a voltage to between the conductive members 32 and 33 and detecting a leakage of the electrolyte according to the conduction between the conductive members 32 and 33. The solid electrolyte body 39 covers the conductive members 32 and 33.SELECTED DRAWING: Figure 5

Description

  The present invention relates to an inspection apparatus.

  2. Description of the Related Art There is known an inspection apparatus which detects a leak of an electrolytic solution filled in an electricity storage module constituting an electricity storage device mounted on an electric vehicle or the like. For example, in the battery structure described in Patent Document 1, an apparatus (inspection apparatus) for detecting a leak of the electrolytic solution is provided on the lower surface of the battery pack (electric storage device). In this inspection apparatus, an insulating tray (substrate) is provided to be in contact with the lower surface of the battery pack, and a pair of printed wiring is provided on the surface of the insulating tray as a conductive member. The leakage of the electrolyte is detected based on the change in the resistance value of the printed wiring.

JP 2007-273353

  In the above-described inspection apparatus, the leaked electrolytic solution adheres to the pair of printed wires such that the leaked electrolytic solution straddles between the pair of printed wires, whereby the pair of printed wires are energized and the resistance value of the printed wires changes. For this reason, it is necessary to expose the printed wiring provided on the surface of the substrate. As a result, for example, the printed wiring may be damaged or broken by direct contact of the printed wiring with the uneven portion in the case of the storage module or the like. If the printed wiring is damaged or broken, the inspection device may not be able to detect the leakage of the electrolyte.

  An object of the present invention is to provide an inspection device which detects leakage of an electrolyte which can reduce the possibility of damage or disconnection of a conductive member.

  An inspection device for solving the above-mentioned subject is an inspection device which detects a leak of an electrolysis solution contained in an accumulation-of-electricity module, and the substrate, the 1st electric conduction member and the 2nd electric conduction member provided in the substrate, the 1st A voltage is applied between the first conductive member and the second conductive member, and a solid electrolyte body in contact with the conductive member and the second conductive member, based on energization between the first conductive member and the second conductive member. And a detection unit that detects a leak of the electrolytic solution. The solid electrolyte body covers the first conductive member and the second conductive member.

  In this inspection apparatus, a solid electrolyte body in contact with the first conductive member and the second conductive member is provided, and the solid electrolyte body covers the first conductive member and the second conductive member. When leakage of the electrolyte solution from the storage module occurs and the electrolyte solution is absorbed by the solid electrolyte body, the solid electrolyte body is in a state in which ions can move. Since a voltage is applied between the first conductive member and the second conductive member, current is conducted between the first conductive member and the second conductive member. Thus, the detection unit detects the leak of the electrolytic solution based on the energization between the first conductive member and the second conductive member. Further, since the solid electrolyte body covers the first conductive member and the second conductive member, the possibility of the first conductive member and the second conductive member being in direct contact with the storage module is reduced. As a result, it is possible to reduce the possibility of the conductive member being damaged or broken.

  The substrate may be provided with a groove, and the groove may contain the first conductive member, the second conductive member, and the solid electrolyte body. In this case, the solid electrolyte body covering the first conductive member and the second conductive member can be formed in a state in which the first conductive member and the second conductive member are accommodated in the groove, so the inspection device can be easily manufactured. It becomes possible.

  The first conductive member and the second conductive member may be printed wiring. For example, when the printed wiring is provided on the surface of the substrate, since the printed wiring is formed of metal foil, the substrate can be thinned.

  The wiring surface on which the first conductive member and the second conductive member of the substrate are provided may have a micro uneven shape at a position facing the first conductive member and the second conductive member. For example, in the case where the first conductive member and the second conductive member are printed wiring, when the printed wiring is formed, the metal foil constituting the printed wiring enters into the concave and convex concave portions of the wiring surface of the substrate. It is possible to increase the adhesion between the first conductive member and the second conductive member, and the substrate.

  The solid electrolyte body may be composed of a proton conductive solid electrolyte. For example, when the electrolytic solution contained in the storage module to be inspected is an alkaline solution, in the above configuration, the solid electrolyte body has conductivity by the alkali component of the electrolytic solution being absorbed by the solid electrolyte body. As a result, current flows between the first conductive member and the second conductive member, so that the leak of the electrolytic solution can be detected by the inspection device.

  The storage module may have a plurality of stacked bipolar electrodes and a resin member surrounding the plurality of bipolar electrodes. Each of the plurality of bipolar electrodes has an electrode plate having a first surface and a second surface opposite to the first surface, a positive electrode provided on the first surface, and a negative electrode provided on the second surface. Alternatively, a resin member may be provided at the edge of the electrode plate. Even when such a storage module is inspected, in the inspection apparatus of the above configuration, the possibility of the conductive member being damaged or broken can be reduced.

  According to the present invention, it is possible to reduce the possibility of damage or disconnection of the conductive member of the inspection apparatus for detecting the leak of the electrolytic solution.

FIG. 1 is a diagram showing a power storage device to which an inspection apparatus according to an embodiment is applied. FIG. 2 is a cross-sectional view showing a storage module of the storage device shown in FIG. FIG. 3 is a cross-sectional view showing a safety valve of the storage module shown in FIG. FIG. 4 is a schematic view of an inspection apparatus according to an embodiment. FIG. 5 is a cross-sectional view taken along the line V-V of FIG. FIG. 6 is a diagram showing another power storage device to which the inspection apparatus is applied. FIG. 7 is a view showing another application example of the inspection apparatus.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. In the description of the drawings, the same or equivalent elements will be denoted by the same reference symbols, without redundant description. For the convenience of description, an orthogonal coordinate system is shown in the following drawings.

  FIG. 1 is a diagram showing a power storage device to which an inspection apparatus according to an embodiment is applied. Power storage device 1 is used, for example, as a battery of various vehicles such as a forklift, a hybrid car, and an electric car. The power storage device 1 includes a power storage module stack 2 and a restraining member 3.

  The storage module stack 2 is a stack configured from a plurality of (here, three) storage modules 4 stacked. The storage module laminate 2 includes a plurality of storage modules 4, a plurality of (here, four) conductive plates 5, a positive electrode terminal 6, a negative electrode terminal 7, and an insulating film 8. Note that the storage module stack 2 may include a single storage module 4.

  The storage module 4 is a bipolar battery having a plurality of bipolar electrodes 15 described later. The storage module 4 is a secondary battery such as, for example, a nickel-hydrogen secondary battery, a nickel-cadmium secondary battery, and a nickel-zinc secondary battery. The storage module 4 may be a lithium ion secondary battery or an electric double layer capacitor. The following description exemplifies a nickel-hydrogen secondary battery.

  The plurality of storage modules 4 are stacked along the Z-axis direction. The storage modules 4, 4 adjacent to each other in the Z-axis direction are electrically connected via the conductive plate 5. The plurality of conductive plates 5 are disposed between two adjacent power storage modules 4 and 4 in the Z-axis direction and outside the power storage modules 4 and 4 positioned at both ends of the power storage module stack 2 in the Z-axis direction. It is done. Conductive plate 5 arranged between two adjacent power storage modules 4 in the Z-axis direction electrically connects adjacent two power storage modules 4.

  The positive electrode terminal 6 is connected to the conductive plate 5 positioned at one end in the Z-axis direction. The negative electrode terminal 7 is connected to the conductive plate 5 positioned at the other end in the Z-axis direction. The positive electrode terminal 6 and the negative electrode terminal 7 extend from the edge of the conductive plate 5 along the X-axis direction in a direction away from the conductive plate 5. Charging and discharging of power storage device 1 are performed via positive electrode terminal 6 and negative electrode terminal 7. Insulating films 8 and 8 having electrical insulation are disposed at both ends of the storage module laminate 2. The insulating film 8 electrically insulates between the conductive plate 5 and an end plate 9 described later.

  Inside each conductive plate 5, a plurality of flow paths 5a for circulating a refrigerant such as air are provided. Each of the plurality of flow paths 5a extends substantially parallel to each other along the Y-axis direction. By the refrigerant flowing through the plurality of flow paths 5 a, the conductive plate 5 releases the heat generated in each of the storage modules 4 to the outside of the storage device 1.

  The restraint member 3 is a member that restrains the storage module stack 2 by sandwiching the storage module stack 2 in the Z-axis direction. The restraint member 3 includes a pair of end plates 9, a bolt 10 and a nut 11. End plate 9 is a substantially rectangular metal plate having a larger area than storage module 4 and conductive plate 5 when viewed in the Z-axis direction.

  Insertion holes 9 a are provided at the corners of each end plate 9 at positions outside the storage module stack 2. The shaft portion 10a of the bolt 10 extends from the insertion hole 9a of one end plate 9 toward the insertion hole 9a of the other end plate 9 along the Z-axis direction, and penetrates the respective insertion holes 9a. . A nut 11 is screwed into an end portion of the shaft portion 10a which protrudes in the Z-axis direction from one of the insertion holes 9a of the pair of end plates 9, 9. The storage module stack 2 is held between the pair of end plates 9 and 9, whereby a restraint load is applied to the storage module stack 2 in the Z-axis direction.

  FIG. 2 is a cross-sectional view showing a storage module of the storage device shown in FIG. The storage module 4 includes an electrode stack 12 and a frame 13 made of resin that seals the electrode stack 12.

  The electrode stack 12 is configured by stacking a plurality of bipolar electrodes 15 along the Z-axis direction via the separator 14. The stacking direction of the electrode stack 12 matches the stacking direction of the storage module stack 2. Each of the plurality of bipolar electrodes 15 includes an electrode plate 16, a positive electrode 17 provided on one surface 16 a (first surface) of the electrode plate 16, and the other surface 16 b (second surface) opposite to one surface. And the negative electrode 18 provided on the The positive electrode 17 is a positive electrode active material layer configured by applying a positive electrode active material. The negative electrode 18 is a negative electrode active material layer configured by being coated with a negative electrode active material. The positive electrode 17 of one bipolar electrode 15 is opposed to the negative electrode 18 of the other bipolar electrode 15 with the separator 14 in the pair of bipolar electrodes 15 and 15 adjacent in the Z-axis direction.

  In the electrode stack 12, the positive electrode termination electrode 19 is disposed at one end in the Z-axis direction. The positive electrode termination electrode 19 includes an electrode plate 16 and a positive electrode 17 provided on one surface 16 a of the electrode plate 16, and the positive electrode 17 of the positive electrode termination electrode 19 is a bipolar disposed at one end in the Z-axis direction. The negative electrode 18 of the electrode 15 and the separator 14 are opposed to each other. One conductive plate 5 adjacent to the power storage module 4 is in contact with the other surface 16 b of the electrode plate 16 of the positive electrode terminal electrode 19.

  In the electrode stack 12, the negative electrode terminal electrode 20 is disposed at the other end in the Z-axis direction. The negative electrode termination electrode 20 includes an electrode plate 16 and a negative electrode 18 provided on the other surface 16 b of the electrode plate 16. The negative electrode 18 of the negative electrode termination electrode 20 is disposed at the other end in the Z-axis direction The positive electrode 17 of the bipolar electrode 15 and the separator 14 are opposed to each other. The other conductive plate 5 adjacent to the storage module 4 is in contact with one surface 16 a of the electrode plate 16 of the negative electrode terminal electrode 20.

  The electrode plate 16 is made of, for example, a metal foil made of nickel or a nickel-plated steel plate, and has a substantially rectangular shape as viewed from the Z-axis direction. As a positive electrode active material which comprises the positive electrode 17, nickel hydroxide is mentioned, for example. As a negative electrode active material which comprises the negative electrode 18, a hydrogen storage alloy is mentioned, for example.

  The separator 14 is formed in a sheet shape. The separator 14 is formed of, for example, a porous film made of a polyolefin resin such as polyethylene (PE) or polypropylene (PP). The separator 14 may be formed of a woven fabric made of polypropylene, polyethylene terephthalate (PET), methylcellulose or the like, or a non-woven fabric made of those materials. The separator 14 may be reinforced with a vinylidene fluoride resin compound. The separator 14 is not limited to a sheet but may be a bag.

  The frame 13 is a member that holds the edge 16 c of the electrode plate 16 on the side surface of the electrode stack 12 extending in the Z-axis direction. The frame 13 is formed of an insulating resin. As a resin material which comprises the frame 13, a polypropylene, polyphenylene sulfide (PPS), or modified polyphenylene ether (modified PPE) etc. are mentioned, for example. The frame 13 is provided around the electrode stack 12 as viewed in the Z-axis direction. That is, the frame 13 is provided so as to surround the side surface of the electrode stack 12. The frame 13 includes a plurality of first resin portions 21 (resin members) provided at the edge 16 c of each electrode plate 16 and a second resin portion 22 provided around the first resin portion 21 when viewed from the Z-axis direction. And.

  The plurality of first resin portions 21 are formed, for example, by injection molding using an insulating resin, and constitute the inner wall of the frame 13. Each first resin portion 21 is provided in the edge portion 16 c of the electrode plate 16 from one surface 16 a to the side surface 16 d. Each first resin portion 21 is continuously provided over all sides of the electrode plate 16 as viewed in the Z-axis direction. Adjacent first resin portions 21 abut each other on a surface extending outward from the other surface 16 b of the electrode plate 16. As a result, the edge 16 c of the electrode plate 16 is buried and held in the adjacent first resin portions 21, 21.

  The second resin portion 22 is formed, for example, by injection molding using an insulating resin, and constitutes the outer wall of the frame 13. The second resin portion 22 extends in the Z-axis direction over the entire length of the electrode stack 12 and is formed in a hollow cylindrical shape. The second resin portion 22 covers the outer side surface of the first resin portion 21 and is welded to the first resin portion 21 inside the second resin portion 22 as viewed in the Z-axis direction.

  An internal space V airtightly partitioned by the electrode plates 16 and the first resin portion 21 is formed between the electrode plates 16 adjacent to each other in the Z-axis direction. A plurality of internal spaces V are formed in the storage module 4. An electrolyte (not shown) made of an alkaline solution is injected (filled) into the internal space V. The alkaline solution has, for example, a strongly alkaline property in which the hydrogen ion concentration (pH) is 12 or more. As an alkaline solution, potassium hydroxide aqueous solution, lithium hydroxide aqueous solution, etc. are mentioned, for example.

  FIG. 3 is a cross-sectional view showing a safety valve of the storage module shown in FIG. The safety valve 23 is provided to connect each of the plurality of internal spaces V with the outside (the atmosphere) of the frame 13. Specifically, the safety valve 23 penetrates the first resin portion 21 and the second resin portion 22 along the X-axis direction. The safety valve 23 has a function of releasing the gas present in the internal space V to the outside of the storage module 4 when the pressure in the internal space V becomes equal to or higher than a predetermined value. In addition, illustration of the safety valve 23 is abbreviate | omitted in FIG.

  The inspection device 30 according to the present embodiment is applied to the storage module 4 described above as an inspection target. The inspection device 30 is a device for detecting a leak of the electrolytic solution contained in the storage module 4. Inspection device 30 is used in the inspection step of the manufacturing process of power storage device 1. In the inspection process, the inspection device 30 is repeatedly used. The inspection device 30 is used, for example, for inspection of a plurality of places in one power storage device 1, and is also used for a test of other plurality of power storage devices.

  In the inspection step, as shown in FIG. 1 and FIG. 2, the inspection device 30 (substrate 31, see FIG. 4) includes, for example, a first resin portion 21 and a second resin portion 22 arranged at one end in the Z-axis direction. Placed in the vicinity of the welded portion with the When the electrolyte leaks from the gap between the first resin portion 21 and the second resin portion 22 arranged at one end in the Z-axis direction, the inspection device 30 detects the leak of the electrolyte. The place where the inspection apparatus 30 is applied may be any place where leakage of the electrolyte is a concern. In the case where the electrolytic solution leaks, before the liquid electrolytic solution leaks, a leak of a trace amount of gas having alkalinity occurs as a sign of the leak of the electrolytic solution.

  For example, a gap between the safety valve 23 and the second resin portion 22 may be mentioned as an example of a portion where there is a concern about leakage of the electrolyte solution. As shown in FIG. 3, if there is a concern that the electrolyte leaks from the gap between the safety valve 23 and the second resin portion 22, in the vicinity of the joint portion between the safety valve 23 and the second resin portion 22, The inspection device 30 (substrate 31) may be disposed. In addition, the gap between the electrode plate 16 and the first resin portion 21 and the gap generated by the crack in the frame 13 or the crack in the frame 13 may be mentioned as a portion where there is a concern about leakage of the electrolytic solution. . In addition, if there is a concern that the electrolytic solution may leak from the gap caused by the peeling of the adhesive surfaces of the first resin portions 21, the portions adjacent to the adjacent first resin portions 21 may be in contact with each other. The inspection apparatus 30 (substrate 31) may be disposed.

  Next, a specific example of the inspection apparatus 30 will be described with reference to FIGS. 4 and 5. FIG. 4 is a schematic view of an inspection apparatus according to an embodiment. FIG. 5 is a cross-sectional view taken along the line V-V of FIG. The inspection apparatus 30 includes a substrate 31, a conductive member 32 (first conductive member), a conductive member 33 (second conductive member), a detection unit 34, and a solid electrolyte body 39.

  The substrate 31 is a plate-like base material that holds the conductive member 32, the conductive member 33, and the solid electrolyte body 39. The substrate 31 has a rectangular shape as viewed in the Z1 axis direction, and extends along the X1 axis direction. A groove 40 extending along the X1 axis direction is provided on the surface 31 a of the substrate 31.

  The substrate 31 has flexibility. The substrate 31 is made of, for example, hard rubber. Examples of hard rubber constituting the substrate 31 include styrene-butadiene rubber (SBR), and silicone rubber. The substrate 31 is made of, for example, hard rubber having a durometer hardness of 60 to 90, which is measured based on the JIS standard (K6253-3: 2012). If the durometer hardness is less than 60, it will be difficult to form the groove 40 in the substrate 31, and furthermore, the groove 40 may not be formed as designed. The substrate 31 may be made of a resin having elasticity, or may be a substrate having no flexibility. The substrate 31 may be flexible printed circuits.

  The bottom surface (wiring surface) of the groove 40 has a micro uneven shape. For example, by forming the groove 40 in the substrate 31 by laser processing, the groove 40 having the fine concavo-convex shape is formed on the bottom surface. The bottom surface of the groove 40 may have a micro uneven shape by performing the ozone treatment on the substrate 31 in which the groove 40 is formed. The ozone treatment is a treatment in which fine irregularities are formed by immersing the substrate 31 in an ozone solution and eroding the surface 31 a (bottom surface of the groove 40) of the substrate 31 by the ozone solution. In the groove 40, the conductive member 32, the conductive member 33, and the solid electrolyte body 39 are accommodated. The bottom surface of the groove 40 has a micro uneven shape at a position facing the conductive member 32 and the conductive member 33. The bottom surface of the groove 40 may have a micro uneven shape on the entire surface including the positions facing the conductive members 32 and 33. The depth of the groove 40 is larger than the height of the conductive member 32 and the height of the conductive member 33.

  The conductive member 32 is a printed wiring, and is made of, for example, a copper foil. The conductive member 32 is provided on the bottom surface of the groove 40 and extends along the X1 axis direction. The conductive member 33 is a printed wiring, and is made of, for example, a copper foil. The conductive member 32 and the conductive member 33 are made of, for example, metal foils of the same type. The conductive member 33 is provided on the bottom surface of the groove 40 and extends along the X1 axis direction. In the substrate 31, the conductive members 32 and the conductive members 33 are provided substantially in parallel at a predetermined interval. The one end 32 a of the conductive member 32 and the one end 33 a of the conductive member 33 in the X1 axis direction are electrically connected to the detection unit 34. The other end 32 b of the conductive member 32 and the other end 33 b of the conductive member 33 in the X1 axis direction are open and not electrically connected. The cross-sectional shape of the conductive member 32 and the conductive member 33 is, for example, a substantially rectangular shape.

  The solid electrolyte body 39 is provided along the X1-axis direction over a length substantially equal to the total length of the conductive members 32 and 33. As shown in FIG. 5, the solid electrolyte body 39 is in contact with the conductive member 32 and the conductive member 33. That is, the conductive member 32 and the conductive member 33 are connected via the solid electrolyte body 39. The solid electrolyte body 39 may be provided along the X1-axis direction, not over the entire length of the conductive member 32 and the conductive member 33, but over a part of the length.

  The solid electrolyte body 39 covers the conductive member 32 and the conductive member 33. Specifically, the solid electrolyte body 39 covers the upper surface and both side surfaces of the conductive member 32, and covers the upper surface and both side surfaces of the conductive member 33. The solid electrolyte body 39 is exposed to the outside of the inspection device 30. The substrate 31 is disposed on the storage module 4 such that the solid electrolyte body 39 and the storage module 4 to be tested face each other when the inspection apparatus 30 is in use. For example, the substrate 31 is disposed on the storage module 4 such that the surface 31 a of the substrate 31 contacts the storage module 4.

  The solid electrolyte body 39 is constituted of, for example, a proton conductive solid electrolyte. When the solid electrolyte body 39 is impregnated (absorbed) with the alkali component, the solid electrolyte body 39 becomes in a state in which ions can move. That is, when the main component (for example, sodium hydroxide) of the alkaline solution constituting the electrolytic solution is sufficiently stably fixed to the solid electrolyte body 39, the solid electrolyte body 39 has conductivity. The material constituting the solid electrolyte body 39 will be described later.

  The detection unit 34 detects a leak of the electrolytic solution based on energization between the conductive member 32 and the conductive member 33. The detection unit 34 includes a power supply 35 that applies a voltage, a voltmeter 36 that measures a voltage, an ammeter 37 that measures a current, and a control unit 38.

  The power source 35 applies a DC voltage between the conductive member 32 and the conductive member 33. The positive electrode of the power source 35 is electrically connected to one end 32 a of the conductive member 32 via an ammeter 37. The negative electrode of the power source 35 is electrically connected to one end 33 a of the conductive member 33. Thus, one end 32 a of the conductive member 32 and one end 33 a of the conductive member 33 are electrically connected via the power supply 35 and the ammeter 37.

  Both ends of the voltmeter 36 are electrically connected to the positive electrode and the negative electrode of the power source 35, respectively. The voltmeter 36 measures the potential difference between both ends of the power source 35 or the potential difference generated between the conductive member 32 and the conductive member 33. The voltmeter 36 outputs the measured voltage value to the control unit 38. Both ends of the ammeter 37 are electrically connected to the positive electrode of the power source 35 and one end 32 a of the conductive member 32, respectively. The ammeter 37 outputs the measured current value to the control unit 38.

  The control unit 38 is, for example, a computer including an input interface having an analog-digital conversion function, a CPU (Central Processing Unit), and a storage device. The control unit 38 calculates the resistance value between the conductive member 32 and the conductive member 33 based on the voltage value measured by the voltmeter 36 and the current value measured by the ammeter 37. For example, the control unit 38 divides the voltage value by the current value to calculate the resistance value. The control unit 38 detects a leak of the electrolytic solution, for example, according to a change in resistance value. The specific detection method will be described later.

  Next, materials constituting the solid electrolyte body 39 will be described. The solid electrolyte body 39 is formed by kneading a powdered solid electrolyte having a particle size of 0.1 μm to 5 μm and a PTFE dispersion composed of PTFE (polytetrafluoroethylene).

  The solid electrolyte constituting the solid electrolyte body 39 is, for example, a solid electrolyte having proton conductivity (proton conductive solid electrolyte). The proton conductive solid electrolyte contains, for example, a composite compound containing polyvinyl alcohol and a zirconate compound as a component. A complex compound containing polyvinyl alcohol and a zirconate compound is a solution in which a zirconium salt or an oxyzirconium salt is hydrolyzed in a solution containing a water-containing solvent, polyvinyl alcohol, and a zirconium salt or an oxyzirconium salt. The solvent is later removed, and the intermediate from which the solvent is removed is formed by contacting an alkaline substance. By including the above-described composite compound, a proton conductive solid electrolyte having high ion conductivity can be obtained.

  The PTFE dispersion is a liquid in which short fibers of PTFE are dispersed in water. When the solid electrolyte body 39 is formed, the PTFE dispersion and the powdered solid electrolyte are mixed and kneaded at a predetermined ratio. By kneading the PTFE dispersion and the solid electrolyte, the short fibers of PTFE physically entangle in three dimensions. As a result, a clay-like potting agent (mixture) rich in elasticity and binding is obtained. The concentration of the PTFE dispersion is, for example, a few percent (weight percent). If the amount of the PTFE dispersion is small, the binding effect may be weakened. Examples of the PTFE dispersion include "Polyflon PTFE D-210C" manufactured by Daikin Industries, Ltd.

  The PTFE dispersion may contain a conductive aid in order to reduce the electrical resistance of the solid electrolyte body 39. The conductive aid is, for example, carbon nanofibers composed of short fibrous carbon fibers. The PTFE dispersion may contain a conductive aid other than carbon nanofibers. Examples of conductive assistants other than carbon nanofibers include acetylene black, carbon black, graphite, and ketjen black. The PTFE dispersion may contain two or more of the above-described materials as a conductive additive.

  A binder may be used instead of the PTFE dispersion. As such a binder, for example, a fluorine-based polymer such as polyvinylidene fluoride (PVDF) or polytetrafluoroethylene can be mentioned. In addition, as the binder, rubber such as styrene butadiene rubber (SBR) and imide type polymers such as polyimide, polyamide imide, or polyamide imide silica hybrid may be mentioned. Furthermore, alkoxysilyl group-containing resin, polyacrylic acid, polymethacrylic acid, polyitaconic acid and the like can be mentioned.

  Further, as a binder, a copolymer of acrylic acid and an acid monomer such as methacrylic acid, itaconic acid, fumaric acid or maleic acid may be used. For example, when any resin of polyimide, polyamideimide, polyamideimide silica hybrid, polyacrylic acid, and carboxymethylcellulose is used as a binder, the binding property of the potting agent is improved. For example, when a polyamideimide resin or a polyamideimide silica hybrid of the above-mentioned resins is used as a binder, the binding property of the potting agent is further improved. One of the plurality of materials described above may be used as a binder, or a combination of two or more may be used as a binder.

  Next, a method of manufacturing the inspection apparatus 30 will be described. First, the groove 40 is formed on the surface 31 a of the substrate 31 by, for example, laser processing. The conductive member 32 and the conductive member 33, which are printed wiring, are formed in the groove 40. Subsequently, the potting agent obtained by kneading the powdery solid electrolyte and the PTFE dispersion is embedded in the groove 40 so as to cover the surface of the conductive member 32 and the conductive member 33 exposed to the outside of the inspection device 30. Be The potting agent embedded in the groove 40 is dried, and the moisture evaporates, whereby a solid electrolyte body 39 covering the conductive member 32 and the conductive member 33 is formed.

  Next, a method of detecting a leak of the electrolytic solution in the inspection apparatus 30 will be described. First, when leakage of the electrolyte does not occur, the solid electrolyte body 39 is not in a state in which ions can move. Furthermore, since the space between the other end 32b of the conductive member 32 and the other end 33b of the conductive member 33 is open, current does not flow from the power supply 35 without conduction between the conductive member 32 and the conductive member 33. . At this time, the resistance value calculated by the control unit 38 is infinite. For this reason, the control unit 38 does not detect leakage of the electrolytic solution, for example, because the calculated resistance value does not change from infinity.

  On the other hand, when the leak of the electrolytic solution occurs and the leaked electrolytic solution is absorbed by the solid electrolyte body 39, the solid electrolyte body 39 is in a state in which ions can move. Therefore, an electrically closed circuit is formed by the power source 35, the conductive member 32, the conductive member 33, and the solid electrolyte body 39. As a result, when the current flows from the power supply 35 to the closed circuit, the resistance value calculated by the control unit 38 changes (decreases). In this case, the control unit 38 detects the leakage of the electrolytic solution in response to the decrease of the resistance value from infinity. That is, the detection unit 34 detects the leakage of the electrolyte based on the energization between the conductive members 32 and 33. The control unit 38 may detect the leak of the electrolytic solution by comparing the calculated resistance value with the threshold value. The detection unit 34 may not have the voltmeter 36. In this case, the control unit 38 may detect the leakage of the electrolyte according to the change in the current value measured by the ammeter 37 or by comparing the current value with the threshold value.

  There is another inspection apparatus for detecting a leak of an electrolytic solution by adhering the leaked electrolytic solution to a pair of conductive members so as to straddle the other conductive member from one conductive member. In this inspection apparatus, the electrolyte needs to be physically and continuously attached to the pair of conductive members. On the other hand, in the above-described inspection apparatus 30, when the solid electrolyte body 39 absorbs the electrolytic solution to such an extent that the solid electrolyte body 39 can move ions, leakage of the electrolytic solution is detected. . Therefore, not only in the case where the leaked electrolyte is liquid, but also in the form of a mist in which the liquid is dispersed in the gas, if the solid electrolyte body 39 is in a state in which ions can move, the electrolyte Can be detected.

  The conductive member 32 and the conductive member 33 are covered by a solid electrolyte body 39. Therefore, even if the conductive member 32 and the portion of the substrate 31 where the conductive member 33 is positioned come into contact with the uneven portion of the storage module 4, the uneven portion or the like contacts the solid electrolyte body 39. Thereby, the possibility that the conductive member 32 and the conductive member 33 directly contact the storage module 4 is reduced. As a result, it is possible to reduce the possibility of disconnection or damage of the conductive member 32 and the conductive member 33.

  Since the depth of the groove 40 is larger than the height of the conductive member 32 and the height of the conductive member 33, the conductive member 32 and the conductive member 33 do not protrude from the surface 31 a of the substrate 31. That is, the conductive members 32 and the conductive members 33 are located in the area defined by the groove 40. For this reason, the possibility that the conductive members 32 and the conductive members 33 directly contact the storage module 4 to be inspected is further reduced. As a result, it is possible to further reduce the possibility that the conductive member 32 and the conductive member 33 are broken or damaged.

  The bottom surface of the groove 40 has a micro uneven shape at a position facing the conductive member 32 and the conductive member 33. For this reason, when the conductive member 32 and the conductive member 33 are formed on the bottom of the groove 40, the metal foils constituting the conductive member 32 and the conductive member 33 enter the concave portion of the fine concavo-convex shape. The adhesion between the member 33 and the substrate 31 is enhanced. As a result, peeling of the conductive member 32 and the conductive member 33 from the substrate 31 (the bottom surface of the groove 40) is suppressed, so the possibility of damaging the conductive member 32 and the conductive member 33 is reduced.

  In the groove 40, the conductive member 32, the conductive member 33, and the solid electrolyte body 39 are accommodated. Therefore, in the state where the conductive member 32 and the conductive member 33 are accommodated in the groove, the clay-like potting agent described above is embedded in the groove 40 so as to cover the conductive member 32 and the conductive member 33 to dry the water. The electrolyte body 39 can be formed in the groove 40. As a result, the inspection apparatus 30 can be easily manufactured. Also, the conductive member 32, the conductive member 33, and the solid electrolyte body 39 can be easily held on the substrate 31.

  As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment.

  In the inspection apparatus 30, although the conductive member 32, the conductive member 33, and the solid electrolyte body 39 are all accommodated in the groove 40, the present invention is not limited thereto. The groove 40 may not be provided in the substrate 31, and the conductive member 32, the conductive member 33, and the solid electrolyte body 39 may be provided on the surface 31 a of the substrate 31. In this case, the surface 31 a (wiring surface) of the substrate 31 may have a fine concavo-convex shape at a position facing the conductive member 32 and the conductive member 33.

  The conductive member 32 and the conductive member 33 are not limited to the printed wiring. The conductive members 32 and 33 may be conductive wires made of metal. The cross-sectional shapes of the conductive member 32 and the conductive member 33 may be circular, oval or polygonal.

  The conductive member 32 and the conductive member 33 extend in only one direction, but may extend in one direction as well as another direction. The conductive member 32 and the conductive member 33 extend linearly, but may extend curvilinearly.

  Leakage of the electrolytic solution is detected by providing the conductive member 32 and the conductive member 33 on the substrate 31. Even if the leak of the electrolytic solution is detected by providing the conductive members in plural sets. Good. In this case, the plurality of conductive members may extend in different directions.

  The substrate 31 of the inspection apparatus 30 extends in one direction, but is not limited thereto. The substrate 31 may extend in one direction and in another direction. The conductive members 32 and the conductive members 33 may extend along the extending direction of the substrate 31. The inspection device 30 may be applied to the storage module 4 by arranging the substrate 31 extending only in one direction so as to be bent and wound around the outer periphery of the storage module 4.

  The inspection target of the inspection apparatus 30 is not limited to the storage module 4. FIG. 6 is a diagram showing another power storage device to which the inspection apparatus is applied.

  As shown in FIG. 6, power storage device 1A includes a plurality of (here, nine) battery cells 51A to 51I. The plurality of battery cells 51A to 51I (storage modules) are arranged in a line along the Y2 axis direction. Each of battery cells 51A to 51I is, for example, a nickel hydrogen secondary battery. Each of battery cells 51A to 51I may be a nickel cadmium secondary battery or a nickel zinc secondary battery. Each of battery cells 51A to 51I may be a lithium ion secondary battery or an electric double layer capacitor.

  Each of the battery cells 51A to 51I includes a case 52 as an exterior member, an electrode assembly accommodated in the case 52, an electrode terminal 53, and a safety valve 54. Inside the case 52, an electrolytic solution composed of an alkaline solution such as a potassium hydroxide aqueous solution is injected (filled). The case 52 has a bottomed square cylindrical main body 52a for housing the electrode assembly, and a lid 52b for closing the opening of the main body 52a. The outer periphery of the lid 52 b is sealed by, for example, laser welding, so that the internal space of the case 52 configured of the main body 52 a and the lid 52 b is sealed.

  The lid 52 b is provided with an electrode terminal 53 and a safety valve 54. The electrode terminal 53 is electrically connected to the electrode assembly housed in the case 52. The safety valve 54 reduces the pressure in the internal space when the pressure in the internal space of the case 52 rises to a predetermined value. The substrate 31 is disposed at one end in the X2-axis direction at a position corresponding to the welded portion between the main body 52a and the lid 52b.

  In power storage device 1A, lid 52b is welded to main body 52a by laser welding, and if there is a defect (for example, a pinhole) in the laser welded portion, there is a risk that the electrolyte may leak from each of battery cells 51A to 51I. . For example, welding defects occur at the welding overlap portion at the start point and the end point when laser welding is performed along the periphery of the lid 52b, or at the corner of the lid 52b where heat by the laser is concentrated there is a possibility. The electrode terminal 53 penetrates the lid 52b and extends to the inside of the case 52, and a seal member such as an O-ring is provided to fill the gap between the electrode terminal 53 and the lid 52b. If a minute gap is generated between the seal member and the electrode terminal 53 or the lid 52b, the electrolyte may leak. Even if the electrolytic solution leaks from such a defect of the laser welded portion or a fine gap generated around the seal member, the inspection device 30 can detect the electrolytic solution leak.

  An alkaline solution as an electrolytic solution has a property of better wettability than an acidic electrolytic solution. That is, the alkaline solution has the property of being easily attached to the solid surface. Further, the hydroxyl group (hydroxy group) contained in the alkaline solution and the component such as potassium are easily separated (ionized). Therefore, a component such as potassium contained in the alkaline solution is likely to move toward the electrode terminal 53 of the positive electrode with the movement of electrons, and the leakage of the electrolytic solution is likely to occur. Furthermore, since the alkaline solution has the property of good wettability, the electrolytic solution easily enters the fine gap and easily leaks from the case 52 to the outside. That is, leakage of the electrolytic solution due to capillary phenomenon is likely to occur. These phenomena are the same in the storage device 1. In an alkaline battery provided with an alkaline solution having such a property, even if a leak of the electrolytic solution occurs, the inspection device 30 can detect the leak of the electrolytic solution.

  FIG. 7 is a view showing another application example of the inspection apparatus. The substrate 31 is disposed along the plurality of safety valves 54 in the Y2 axis direction. According to this configuration, it is possible to detect the electrolytic solution leaking from the junction between the safety valve 54 and the lid 52b. Alternatively, it is possible to detect the operation of the safety valve 54 accompanying the increase of the internal pressure of the case 52.

The solid electrolyte constituting the solid electrolyte body 39 is not limited to the proton conductive solid electrolyte. Examples of the material of the solid electrolyte constituting the solid electrolyte body 39 in which ions can be transferred by absorbing the electrolytic solution contained in the lithium ion secondary battery include, for example, La _{0. 51} Li _0.34 TiO _2.94 , Li _1.3 Al _0.3 Ti _1.7 (PO ₄ ) _{3 having} a NASICON-type crystal structure, and Li ₇ La ₃ Zr ₂ O ₁₂ having a garnet-type crystal structure. Be These oxide-based solid electrolytes have the property of being resistant to oxidation (deterioration) in the air at room temperature. Other, as the material for the solid electrolyte, for _example, Li ₂ S-SiS 2 based _sulfides, Li ₁₀ Ge 2 _{PS 12,} and _Li 2 _S-P 2 _{S 5,} and the like. These sulfide-based solid electrolytes have high conductivity, for example, of about 10 ⁻³ S / cm at room temperature.

  Inspection device 30 may be provided in power storage devices 1 and 1A mounted in a vehicle. In this case, the control unit 38 may be an ECU (Electronic Control Unit).

  Since the positive electrode 17 and the negative electrode 18 included in the storage module 4 are made of materials different from each other, the degree of expansion and contraction of the positive electrode 17 and the negative electrode 18 accompanying charging and discharging of the storage module 4 are different from each other. Therefore, a gap may be formed between the first resin portions 21 adjacent to each other in the stacking direction, and the electrolyte may leak through the gap. As described above, even if the electrolytic solution leaks through the gap generated between the first resin portions 21, the inspection device 30 described above can detect the electrolytic solution leak.

  1, 1A: power storage device, 4: storage battery module, 30: inspection device, 31: substrate, 32, 33: conductive member, 34: detection portion, 39: solid electrolyte body, 40: groove.

Claims (6)

An inspection apparatus for detecting leakage of an electrolytic solution contained in a storage module, the inspection apparatus comprising:
A substrate,
A first conductive member and a second conductive member provided on the substrate;
A solid electrolyte body in contact with the first conductive member and the second conductive member;
A detection unit that applies a voltage between the first conductive member and the second conductive member, and detects leakage of the electrolytic solution based on energization between the first conductive member and the second conductive member; , And
The solid electrolyte body covers the first conductive member and the second conductive member.
Inspection device. The substrate is provided with a groove,
The groove accommodates the first conductive member, the second conductive member, and the solid electrolyte body.
The inspection apparatus according to claim 1. The first conductive member and the second conductive member are printed wiring.
The inspection apparatus according to claim 1 or 2. The wiring surface of the substrate on which the first conductive member and the second conductive member are provided has a micro uneven shape at a position facing the first conductive member and the second conductive member.
The inspection apparatus according to claim 3. The solid electrolyte body is composed of a proton conductive solid electrolyte
The inspection apparatus according to any one of claims 1 to 4. The storage module includes a plurality of stacked bipolar electrodes, and a resin member surrounding the plurality of bipolar electrodes.
Each of the plurality of bipolar electrodes includes an electrode plate having a first surface and a second surface opposite to the first surface, a positive electrode provided on the first surface, and a negative electrode provided on the second surface. Have and
The resin member is provided at the edge of the electrode plate,
The inspection apparatus according to any one of claims 1 to 5.

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