Inspection apparatus, manufacturing apparatus for laminated electrodes and inspection methods

Abstract

The inspection device (34) is a device for inspecting the position of the electrode plate (7) in a laminate where the spacer (5) and the electrode plate (7) are bonded together by an adhesive from the spacer (5) side. The inspection device (34) includes: an infrared irradiation unit (40) that irradiates the laminate with infrared light (IR) with a peak wavelength in the range of 6.5 μm to 9.6 μm from the spacer (5) side; a camera (42) that is sensitive in the wavelength region of infrared light (IR) and captures infrared light (IR) reflected by the electrode plate (7) through the spacer (5); and a detection unit (32) that detects the position of the electrode plate (7) based on the image captured by the camera (42).

Description

Technical Field

[0001] This disclosure relates to an inspection apparatus, an apparatus for manufacturing laminated electrodes, and an inspection method. Background Technology

[0002] In recent years, with the increasing popularity of electric vehicles (EVs), hybrid vehicles (HVs), and plug-in hybrid vehicles (PHVs), the production of secondary batteries for automotive applications has increased. This is especially true for lithium-ion secondary batteries. Furthermore, secondary batteries are not limited to automotive applications; for example, they are increasingly used as power sources for portable devices such as laptops. Among these secondary batteries, stacked batteries are known. Generally, stacked batteries have a structure in which multiple positive and negative electrode plates are alternately stacked with spacers, and the electrolyte is contained within an outer casing.

[0003] One method for forming a stacked electrode body includes a method for sequentially stacking a stacked unit consisting of two electrode plates and two spacers. The stacked unit has a structure with four layers of alternating electrode plates and spacers bonded together by an adhesive. In this method, when sequentially stacking the stacked units, efforts are made to minimize the misalignment of the electrode plates. This is because misalignment of the electrode plates can hinder the improvement of the secondary battery's performance. For example, if the positive electrode plate extends beyond the negative electrode plate, repeated charging and discharging can cause lithium deposition, potentially leading to electrical defects such as short circuits.

[0004] Therefore, in the stacking process of laminated units, it is desirable to check the position of the electrode plates in the stacked laminated units. In this regard, Patent Document 1 discloses an electrode position detection device that projects infrared light that passes through the spacer but not through the electrode into an electrode disposed in a bag-shaped spacer, and detects the position of the electrode by receiving the infrared light reflected by the electrode through a camera.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2012-221713 Summary of the Invention

[0008] The technical problem that the invention aims to solve

[0009] In existing detection devices, the adhesive strength of the bonding agent may decrease due to the heat from infrared radiation irradiating the laminated units. If the adhesive strength decreases, the spacers may peel off, exposing the electrode plates, which may then develop wrinkles. This exposure or wrinkling can also cause short circuits or uneven electrolyte impregnation.

[0010] This disclosure was made in view of the following circumstances, and its purpose is to provide a technique for detecting the position of the electrode plate while suppressing the reduction of the adhesive strength of the spacer and the electrode plate.

[0011] Methods for solving technical problems

[0012] One aspect of this disclosure is an inspection apparatus for inspecting the position of an electrode plate in a laminate where spacers and electrode plates are bonded together by an adhesive from the spacer side. The inspection apparatus includes: an infrared irradiation unit that irradiates the laminate from the spacer side with infrared light having a peak wavelength in the range of 6.5 μm to 9.6 μm; a camera that is sensitive in the infrared wavelength region and captures infrared light reflected from the electrode plate after passing through the spacer; and a detection unit that detects the position of the electrode plate based on the image captured by the camera.

[0013] Another aspect of this disclosure is a manufacturing apparatus for a laminated electrode body. This manufacturing apparatus includes: a lamination stage, a laminate containing a lamination spacer and electrode plates bonded together by an adhesive, a transfer unit for transferring the laminate to the lamination stage, and an inspection device as described above for inspecting the position of the electrode plates in the laminate released from the transfer unit; and overlapping the laminates to manufacture the laminated electrode body.

[0014] Another aspect of this disclosure is a method for inspecting the position of an electrode plate in a laminate where the spacer and electrode plate are bonded together by an adhesive from the spacer side. This method includes: irradiating the laminate with infrared light of a peak wavelength in the range of 6.5 μm to 9.6 μm from the spacer side; capturing an image of the infrared light reflected by the electrode plate through the spacer using a camera sensitive to the infrared wavelength region; and detecting the position of the electrode plate based on the image captured by the camera.

[0015] Any combination of the above-mentioned constituent elements, as well as schemes that substitute the present disclosure among methods, apparatuses, systems, etc., are also valid solutions of the present invention.

[0016] Invention Effects

[0017] According to this disclosure, it is possible to suppress the decrease in the bonding strength between the spacer and the electrode plate while checking the position of the electrode plate. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of a production line for manufacturing an apparatus for a stacked electrode body according to the embodiments.

[0019] Figure 2 (A) is a schematic diagram of a stacked unit with a four-layer structure. Figure 2 (B) is a schematic diagram of a stacked unit with a three-layer structure.

[0020] Figure 3 (A) and Figure 3 (B) is a cross-sectional view of the spacer.

[0021] Figure 4 (A) is a schematic diagram of the infrared irradiation unit and camera as viewed from the second direction. Figure 4 (B) is a schematic diagram of the infrared irradiation unit and camera as viewed from the first direction.

[0022] Figure 5 (A) is a schematic diagram of the infrared irradiation unit and camera provided by the inspection device of Embodiment 2 as viewed from the second direction. Figure 5 (B) is a schematic diagram of the infrared irradiation unit and camera viewed from the first direction.

[0023] Figure 6 (A) is a schematic diagram of the infrared irradiation unit and camera provided by the inspection device of Embodiment 3 as viewed from the second direction. Figure 6 (B) is a magnified schematic diagram showing the infrared irradiated surface.

[0024] Figure 7 This is a schematic diagram of the infrared irradiation unit and camera included in the inspection device of Embodiment 4.

[0025] Figure 8 This is a schematic diagram of the inspection device used in verification test I.

[0026] Figure 9 This is a graph showing the results of verification experiment I.

[0027] Figure 10 (A) is a schematic diagram of the inspection device of Example 1. Figure 10 (B) is an image obtained by the inspection device of Example 1. Figure 10 (C) is a schematic diagram of the inspection device of Example 2. Figure 10 (D) is the image obtained by the inspection device of Example 2. Figure 10 (E) is a schematic diagram of the inspection device of Example 3. Figure 10 (F) is the image obtained by the inspection device of Example 3. Figure 10 (G) is a schematic diagram of the inspection device of Example 4. Figure 10 (H) is the image obtained by the inspection device of Example 4. Detailed Implementation

[0028] The present disclosure will now be described with reference to the accompanying drawings based on preferred embodiments. These embodiments are not intended to limit the present disclosure but are illustrative, and all features or combinations thereof described in the embodiments do not necessarily represent the essential content of the present disclosure. For the same or equivalent constituent elements, components, and processes shown in the various drawings, the same reference numerals are used, and repeated descriptions are omitted where appropriate. Furthermore, the scales or shapes of the parts shown in the various drawings are set for ease of explanation and are not intended to be limiting unless specifically mentioned. Additionally, when terms such as "first" and "second" are used in this specification or claims, unless specifically mentioned, these terms do not indicate any order or importance, but are used to distinguish one configuration from other configurations. Furthermore, in the various drawings, parts of less important components are omitted when describing the embodiments.

[0029] (Implementation Method 1)

[0030] Figure 1 This is a schematic diagram of a production line for manufacturing an apparatus for a stacked electrode body, including embodiments thereof. Figure 2 (A) is a schematic diagram of a stacked unit with a four-layer structure. Figure 2 (B) is a schematic diagram of a stacked unit with a three-layer structure. The stacked units in each figure illustrate the state of the perspective spacer. Figure 3 (A) and Figure 3 (B) is a cross-sectional view of the spacer.

[0031] The fabrication apparatus 1 for the stacked electrode body 100 is an apparatus that manufactures the stacked electrode body 100 by stacking stacked body units 2 (stacks) on a stacking stage 4. The stacked electrode body 100 is, for example, composed of 30 to 40 stacked body units 2. The resulting stacked electrode body 100 is used, for example, in a lithium-ion secondary battery. Examples of stacked body units 2 include... Figure 2 The unit shown in (A) has a four-layer structure, and as shown in (A) Figure 2 The unit shown in (B) has a three-layer structure.

[0032] The four-layer laminated unit 2 has two spacers 5 and two electrode plates 7 stacked together and bonded together with an adhesive. Specifically, the first spacer 6, the first electrode plate 8, the second spacer 10, and the second electrode plate 12 are arranged in order from top to bottom. The three-layer laminated unit 2 has two spacers 5 and one electrode plate 7 stacked together and bonded together with an adhesive. Specifically, the first spacer 6, the first electrode plate 8, and the second spacer 10 are arranged in order from top to bottom. In this embodiment, the first electrode plate 8 is the negative electrode plate, and the second electrode plate 12 is the positive electrode plate. In the following text, when it is not necessary to distinguish between the first electrode plate 8 and the second electrode plate 12, they will both be referred to as electrode plate 7, and when it is not necessary to distinguish between the first spacer 6 and the second spacer 10, they will both be referred to as spacer 5.

[0033] The positive electrode plate has a positive current collector and a positive active material layer. The positive active material layer is laminated on both sides or one side of the positive current collector. Either the positive current collector or the positive active material layer can be made of known materials, and either has a known structure. The positive current collector is, for example, made of a foil or porous body made of stainless steel or aluminum. The positive active material layer is formed by coating a positive electrode slurry containing a positive active material such as lithium cobalt oxide or lithium iron phosphate, a binder, and a dispersant onto the surface of the positive current collector, and then drying and calendering the coating.

[0034] The negative electrode plate has a negative current collector and a negative active material layer. The negative active material layer is laminated on both sides or one side of the negative current collector. Both the negative current collector and the negative active material layer can be made of known materials and have known structures. The negative current collector is, for example, made of foil or porous material made of copper or aluminum. The negative active material layer is formed by coating a negative electrode slurry containing a negative active material such as graphite, a binder, and a dispersant onto the surface of the negative current collector, and then drying and calendering the coating.

[0035] As an example of spacer 5, Figure 3 The adhesive spacer shown in (A), and Figure 3 The heat-resistant adhesive spacer shown in (B) consists of a substrate 14 and an adhesive layer 16. The substrate 14 is a resin sheet made of a polyolefin such as polyethylene (PE) or polypropylene (PP). The adhesive layer 16 is made of polyethylene terephthalate (PMMA), polyvinylidene fluoride resin (PVDF), etc., and is laminated on both sides of the main surface of the substrate 14. Alternatively, the adhesive layer 16 may be laminated only on one side of the main surface of the substrate 14. Furthermore, the adhesive constituting the adhesive layer 16 may be applied to the entire main surface of the substrate 14, or it may be applied locally, for example, in dots.

[0036] The heat-resistant adhesive spacer is composed of a substrate 14, an adhesive layer 16, and a heat-resistant agent layer 18. The substrate 14 and adhesive layer 16 are as described above. The heat-resistant agent layer 18 is a layer with at least higher heat resistance than the substrate 14, and is composed of, for example, boehmite, magnesium oxide, barium sulfate, aramid fiber, etc. The heat-resistant agent layer 18 is located between the substrate 14 and the adhesive layer 16. That is, the heat-resistant agent layer 18 is laminated on one or both main surfaces of the substrate 14, and the adhesive layer 16 is laminated on top of the heat-resistant agent layer 18.

[0037] The first electrode plate 8 is bonded to the adhesive layer 16 of the first spacer 6 and the adhesive layer 16 of the second spacer 10. The second electrode plate 12 is bonded to the adhesive layer 16 of the second spacer 10. The adhesive layer 16 exerts its adhesive force when heated to a predetermined set temperature, thus holding the electrode plate 7. Furthermore, if the adhesive layer 16, which is in the bonded state of the electrode plate 7, is heated to a temperature above the set temperature, the adhesive force decreases, and the electrode plate 7 is released from holding. For example, when the adhesive layer 16 is heated to a temperature above the glass transition point, the resin constituting the adhesive layer 16 melts, and the adhesive force decreases. In addition, the adhesive layer 16 can maintain the state of the electrode plate 7 connected to the spacer 5 at room temperature (e.g., 20-25°C).

[0038] In the production line of the stacked electrode body 100, multiple stacked body units 2 are transported as continuous stacked bodies 20 connected by strip-shaped spacer connectors 22. The spacer connectors 22 are cut by a cutter 23, and the stacked body units 2 are individually cut. At this time, the spacer connectors 22 are cut between adjacent electrode plates 7 in the transport direction of the continuous stacked body 20. The cut spacer connectors 22 become spacers 5 in the stacked body units 2. The individually cut stacked body units 2 are transported to the manufacturing apparatus 1 by a transport unit 24. The transport unit 24 is, for example, composed of an adsorption pad that adsorbs and holds the stacked body units 2 by drawing air from an adsorption hole.

[0039] Before reaching the manufacturing apparatus 1 of the stacked electrode body 100, the position of the stacked unit 2 relative to the transport unit 24 is checked. This position check is referred to as the first position check. In the first position check, the stacked unit 2 is photographed by a camera 28 while light of a predetermined wavelength is illuminating the stacked unit 2 from the illumination device 26. The image captured by the camera 28 is transmitted to the control device 30. The control device 30 has a detection unit 32 that performs the first position check. The detection unit 32 performs predetermined image processing on the image obtained from the camera 28 and detects the position of the stacked unit 2 relative to the transport unit 24.

[0040] The control device 30, as a hardware structure, is implemented through components or circuits, such as a computer's CPU or memory, and as a software structure, it is implemented through computer programs, etc. Figure 1 In this diagram, functional blocks are drawn as functional blocks that are realized through their collaboration. Those skilled in the art will understand that these functional blocks can be implemented in various forms through a combination of hardware and software.

[0041] The laminated unit 2, which undergoes a first position check, is transferred by the transfer unit 24 to the manufacturing apparatus 1 for the laminated electrode body 100. The manufacturing apparatus 1 for the laminated electrode body 100 includes a lamination stage 4, a transfer unit 24, and an inspection device 34. The operation of each part of the manufacturing apparatus 1 is controlled by the control device 30. Therefore, the control device 30 can be interpreted as constituting part of the manufacturing apparatus 1.

[0042] When the transfer unit 24 reaches the stacking position opposite to the stacking stage 4, it stops drawing air from the adsorption holes and releases the stacked unit 2 onto the stacking stage 4. The drive of the transfer unit 24 is controlled by the transfer control unit 36 ​​of the control device 30. By sequentially releasing the stacked unit 2 from multiple transfer units 24, the stacked unit 2 is stacked on the stacking stage 4.

[0043] The stacking stage 4 can be driven in the X-axis and Y-axis directions, which are orthogonal to each other. Furthermore, it can be driven in the Z-axis direction, which is orthogonal to the X-axis and Y-axis directions. It can also rotate around the Z-axis. The X-axis and Y-axis directions are horizontal, and the Z-axis direction is vertical. The drive of the stacking stage 4 is controlled by the stage control unit 38 of the control device 30. When the stacked unit 2 is released from the transport unit 24, the stage control unit 38 adjusts the position of the stacking stage 4 relative to the stacked unit 2 located directly above it, based on the position information of the stacked unit 2 obtained from the first position check. This corrects for any offset in the adsorption position of the stacked unit 2 in the transport unit 24, allowing the stacked unit 2 to be stacked on the stacking stage 4 with high positional accuracy.

[0044] After the stacked unit 2 is released from the transfer unit 24 onto the stacking stage 4, the position of the stacked unit 2 mounted on the stacking stage 4 is checked by the inspection device 34. The inspection device 34 checks the position of the electrode plate 7 in the stacked unit 2 from the spacer 5 side. In this embodiment, the position of the first electrode plate 8 is checked through the first spacer 6.

[0045] The inspection device 34 includes an infrared irradiation unit 40, a camera 42, a reflector 44, and a detection unit 32. The infrared irradiation unit 40 irradiates the laminate unit 2 from the spacer 5 side with infrared (IR) rays (far-infrared rays) whose peak wavelength is in the range of 6.5 μm to 9.6 μm. This infrared IR ray is an electromagnetic wave that passes through the spacer 5 (transmitting with a specified transmittance or higher) but does not pass through the electrode plate 7 (transmitting with a transmittance less than a specified transmittance). The transmittance of the infrared IR ray to the spacer 5 is, for example, 50% or higher. Furthermore, the transmittance of the infrared IR ray to the electrode plate 7 is, for example, less than 50%. The irradiation time of the infrared IR ray to each laminate unit 2 is, for example, 1 second or less.

[0046] The camera 42 is sensitive in the infrared (IR) wavelength region and captures the infrared (IR) reflected by the transmission spacer 5 and the electrode plate 7. Preferably, the camera 42 has a germanium lens at the infrared (IR) entrance. Because of its high infrared (IR) transmittance, the germanium lens can more effectively capture images of the electrode plate 7. Furthermore, since the infrared (IR) wavelength in this embodiment is 6 μm or higher, a chalcogenide glass lens with the same high transmittance as the germanium lens can also be used.

[0047] Figure 4 (A) is a schematic diagram of the infrared irradiation unit 40 and the camera 42 as viewed from the second direction B. Figure 4 (B) is a schematic diagram of the infrared irradiation unit 40 and the camera 42 as viewed from the first direction A. In this embodiment, the infrared irradiation unit 40 is fixed in a position to horizontally irradiate infrared radiation (IR). Furthermore, the infrared irradiation unit 40 and the camera 42 are arranged horizontally. Hereinafter, the direction in which the infrared irradiation unit 40 and the camera 42 are arranged will be referred to as the first direction A, the horizontal direction orthogonal to the first direction A will be referred to as the second direction B, and the vertical direction orthogonal to both the first direction A and the second direction B will be referred to as the third direction C.

[0048] The infrared irradiation unit 40 includes a heat source 46, a thermocouple 48, a metal plate 50, a mounting bracket 52, and a heat insulation plate 54. The heat source 46 can be a rubber heater or the like. The thermocouple 48 controls the output of the heat source 46. One main surface of the metal plate 50 is thermally conductively fixed to the heat source 46, uniformly distributing the heat generated by the heat source 46. The metal plate 50 is, for example, made of copper. The other main surface of the metal plate 50 constitutes the infrared irradiation surface 56. The infrared irradiation surface 56 is blackbody coated to suppress unwanted infrared (IR) radiation or reflection.

[0049] The mounting bracket 52, clamping the heat source 46, is positioned on the opposite side of the metal plate 50 and connected to an external support mechanism. A heat insulation plate 54, for example a baking plate, is disposed between the heat source 46 and the mounting bracket 52. The heat insulation plate 54 suppresses heat conduction from the heat source 46 to the mounting bracket 52.

[0050] Camera 42 is positioned in the infrared IR optical path, between infrared irradiation unit 40 and laminate unit 2. Specifically, camera 42 is positioned in front of infrared irradiation surface 56 in the infrared IR irradiation direction. Furthermore, infrared irradiation unit 40 and camera 42 are arranged such that the infrared irradiation axis of infrared irradiation unit 40 extends parallel to the optical axis of camera 42. Infrared irradiation unit 40 has an infrared irradiation surface 56 that extends outward from camera 42 when viewed from a first direction A where camera 42 and infrared irradiation unit 40 are arranged. Therefore, infrared IR irradiated from the area overlapping with camera 42 in infrared irradiation surface 56 obstructs its path towards laminate unit 2, but infrared IR irradiated from the area surrounding camera 42 can reach the laminate unit 2.

[0051] A reflector 44 is positioned downstream of the camera 42 in the infrared (IR) optical path, reflecting infrared (IR) light towards the stacked unit 2. Thus, the infrared (IR) light irradiated horizontally from the infrared irradiation section 40 propagates towards the stacked unit 2 mounted on the stacking stage 4. The reflector 44 is preferably gold-plated on its reflective surface. This increases the reflectivity of the infrared (IR), allowing for efficient and effective imaging of the electrode plate 7.

[0052] Infrared light (IR) irradiates the laminated unit 2 from the spacer 5 side, passes through the spacer 5, and reaches the electrode plate 7. The infrared light (IR) reaching the electrode plate 7 is reflected by the electrode plate 7, passes through the spacer 5 again, is reflected by the reflector 44, and enters the camera 42. Thus, the camera 42 captures an image of the laminated unit 2. Furthermore, if the infrared irradiation unit 40 is fixed in a posture that allows direct irradiation of the laminated unit 2 with infrared light (IR), the reflector 44 can be omitted.

[0053] The camera 42 sends the captured image information to the detection unit 32. The detection unit 32 detects the position of the electrode plate 7 based on the image captured by the camera 42. This position check is called a second position check. Regarding the second position check, the detection unit 32 pre-stores reference position information of the electrode plate 7 and a threshold value for the offset from the reference position. The reference position information is, for example, the position information of two defined corners of the electrode plate 7. After acquiring an image from the camera 42, the detection unit 32 organizes the positions of the two corners in the image into reference positions. Furthermore, if the offset of the two corners relative to the reference position is greater than the threshold value, the detection unit 32 determines that the stacking position of the laminate unit 2 is inappropriate.

[0054] The detection unit 32 sends the judgment result to the transfer control unit 36. After receiving the judgment result from the detection unit 32, the transfer control unit 36 ​​controls the transfer unit 24 to remove the laminated unit 2 that is judged to be unsuitable from the lamination table 4 by re-attaching it. Furthermore, the transfer control unit 36 ​​controls the transfer unit 24 to either re-laminate the removed laminated unit 2 or to remove it from the production line.

[0055] In this embodiment, the detection unit 32 performs both a first position check and a second position check, but the first and second position checks can also be performed by different detection units. Furthermore, the detection unit 32 performing the second position check can be independent of the control devices 30 controlling each part of the manufacturing apparatus 1. Additionally, the infrared irradiation unit 40 and the camera 42 can also be used in the first position check.

[0056] By setting the peak wavelength range of infrared (IR) to 6.5 μm to 9.6 μm, the temperature rise of the laminate unit 2 irradiated by infrared (IR) can be suppressed to below 50°C, preferably below 40°C. This suppresses the decrease in adhesive strength of the adhesive layer 16 while allowing the electrode plate 7 to be photographed through the spacer 5.

[0057] As explained above, the inspection device 34 of this embodiment is an apparatus for inspecting the position of the electrode plate 7 in the laminate of the spacer 5 and the electrode plate 7 from the spacer 5 side. It includes: an infrared irradiation unit 40, which irradiates infrared IR with a peak wavelength in the range of 6.5μm to 9.6μm from the spacer 5 side to the laminate unit 2; a camera 42, which is sensitive in the wavelength region of infrared IR and captures infrared IR reflected by the electrode plate 7 through the spacer 5; and a detection unit 32, which detects the position of the electrode plate 7 based on the image captured by the camera 42.

[0058] In this way, by irradiating the laminate unit 2 with infrared light of a specific wavelength (IR) to detect the position of the electrode plate 7, the adhesive layer 16 can be prevented from rising to a temperature that reduces adhesive strength. Therefore, the position of the electrode plate 7 can be checked through the spacer 5 while maintaining the adhesive bond between the spacer 5 and the electrode plate 7.

[0059] Furthermore, the manufacturing apparatus 1 for the stacked electrode body 100 in this embodiment includes: a stacking stage 4, a stacked unit 2 bonded together with a stacking spacer 5 and an electrode plate 7 using an adhesive; a transfer unit 24 for transferring the stacked unit 2 and releasing it onto the stacking stage 4; and an inspection device 34 for detecting the position of the electrode plate 7 in the stacked unit 2 released from the transfer unit 24. This improves the quality of the stacked electrode body 100 and achieves a balance between increased capacity and safety in secondary batteries.

[0060] Furthermore, in the inspection apparatus 34 of this embodiment, the camera 42 is disposed in the infrared IR optical path, between the infrared irradiation unit 40 and the laminated unit 2. The infrared irradiation unit 40 has an infrared irradiation surface 56 that extends outward from the camera 42 when viewed from a first direction A where the camera 42 and the infrared irradiation unit 40 are arranged. This improves the incident efficiency of infrared IR reflected from the electrode plate 7 onto the camera 42, resulting in a higher contrast image. Consequently, the position of the electrode plate 7 can be detected with higher precision.

[0061] (Implementation Method 2)

[0062] Embodiment 2 has a structure common to Embodiment 1, except for the shape of the infrared irradiation unit 40 and the arrangement of the infrared irradiation unit 40 and the camera 42. Hereinafter, this embodiment will be described focusing on the structure different from Embodiment 1, while the common structure will be described simply or omitted. Figure 5 (A) is a schematic diagram of the infrared irradiation unit 40 and camera 42 of the inspection device 34 of Embodiment 2 as viewed from the second direction B. Figure 5 (B) is a schematic diagram of the infrared irradiation unit 40 and the camera 42 viewed from the first direction A.

[0063] The infrared irradiation unit 40 of this embodiment, like the infrared irradiation unit 40 described in Embodiment 1, includes a heat source 46, a thermocouple 48, a metal plate 50, a mounting bracket 52, a heat insulation plate 54, and an infrared irradiation surface 56. Furthermore, the infrared irradiation surface 56 has a through hole 58. In this embodiment, the through hole 58 extends from the infrared irradiation surface 56 to the heat insulation plate 54, penetrating the entire infrared irradiation unit 40 in the first direction A. Moreover, viewed from the first direction A where the infrared irradiation unit 40 and the camera 42 are arranged, the infrared irradiation unit 40 and the camera 42 are configured such that the through hole 58 overlaps with the optical axis O of the camera 42.

[0064] This improves the incident efficiency of infrared (IR) light reflected from the electrode plate 7 onto the camera 42, resulting in images with higher contrast. Consequently, the position of the electrode plate 7 can be checked with greater precision. Alternatively, the camera 42 can be positioned on the back side of the infrared irradiation unit 40, with at least a portion of the camera 42 disposed within the through-hole 58. By positioning the infrared irradiation unit 40 on the back side of the camera 42, the overlap of the through-hole 58 and the optical axis O reduces the amount of infrared (IR) light obstructed by the camera 42, thereby improving the utilization efficiency of the infrared (IR) light.

[0065] (Implementation Method 3)

[0066] Embodiment 3 has a structure common to Embodiment 1 or 2, except for the shape of the infrared irradiation section 40. Hereinafter, this embodiment will be described focusing on the structure different from Embodiment 1; common structures will be described simply or omitted. Figure 6 (A) is a schematic diagram of the infrared irradiation unit 40 and camera 42 of the inspection device 34 of Embodiment 3 as viewed from the second direction B. Figure 6 (B) is a magnified schematic diagram showing the infrared irradiation surface 56.

[0067] The infrared irradiation unit 40 of this embodiment, like the infrared irradiation unit 40 described in Embodiment 1, includes a heat source 46, a thermocouple 48, a metal plate 50, a mounting bracket 52, a heat insulation plate 54, and an infrared irradiation surface 56. Furthermore, like the infrared irradiation surface 56 described in Embodiment 2, the infrared irradiation surface 56 has a through hole 58. The through hole 58 extends from the infrared irradiation surface 56 to the heat insulation plate 54, penetrating the entire infrared irradiation unit 40 in the first direction A. Viewed from the first direction A where the infrared irradiation unit 40 and the camera 42 are arranged, the infrared irradiation unit 40 and the camera 42 are configured such that the through hole 58 overlaps with the optical axis O of the camera 42.

[0068] Furthermore, the infrared irradiation unit 40 of this embodiment has an infrared irradiation surface 56 including a first irradiation region 56a and a second irradiation region 56b. The first irradiation region 56a allows infrared IR to enter the laminate unit 2 at a predetermined first incident angle θ1. The second irradiation region 56b allows infrared IR to enter the laminate unit 2 at a second incident angle θ2, which is different from the first incident angle θ1.

[0069] As an example of an infrared irradiation surface 56 including a first irradiation region 56a and a second irradiation region 56b, the infrared irradiation section 40 has a parabolic shape (parabolic surface shape) infrared irradiation surface 56. In this case, the infrared irradiation section 40 is preferably configured such that the focal point of the parabola is located near the laminate unit 2, or overlaps with the laminate unit 2. In the parabolic infrared irradiation surface 56, infrared IR irradiated from the first irradiation region 56a located on the outer side of the infrared irradiation surface 56 is incident into the laminate unit 2 at a predetermined first incident angle θ1. On the other hand, infrared IR irradiated from the second irradiation region 56b located closer to the center of the infrared irradiation surface 56 than the first irradiation region 56a is incident into the laminate unit 2 at a second incident angle θ2 smaller than the first incident angle θ1.

[0070] In this way, by causing infrared IR rays irradiated from the infrared irradiation surface 56 to be incident on the stacked unit 2 at multiple incident angles, the incident efficiency of infrared IR rays reflected from the electrode plate 7 to the camera 42 can be improved, resulting in images with higher contrast. As a result, the position of the electrode plate 7 can be checked with higher precision. Furthermore, high contrast enhancement based on images of infrared IR rays incident on the stacked unit 2 at multiple incident angles and high contrast enhancement based on images of the overlapping through-hole 58 and the optical axis O observed from the first direction A can be implemented independently.

[0071] (Implementation Method 4)

[0072] Embodiment 4 has a structure common to Embodiment 1, except for the arrangement of the infrared irradiation unit 40 and the camera 42. Hereinafter, this embodiment will be described focusing on the structure different from Embodiment 1, while the common structure will be described simply or omitted. Figure 7 This is a schematic diagram of the infrared irradiation unit 40 and camera 42 provided in the inspection device 34 of Embodiment 4.

[0073] The infrared irradiation unit 40 of this embodiment, like the infrared irradiation unit 40 described in Embodiment 1, includes a heat source 46, a thermocouple 48, a metal plate 50, a mounting bracket 52, a heat insulation plate 54, and an infrared irradiation surface 56. Furthermore, the infrared irradiation surface 56 of this embodiment has a central axis P that is inclined relative to the normal n of the laminate unit 2. The central axis P is, for example, an imaginary straight line extending towards the laminate unit 2 side from the geometric center of the outline shape of the infrared irradiation surface 56 as viewed from the laminate unit 2 side. Additionally, the camera 42 is configured such that its optical axis O is inclined relative to the normal n of the laminate unit 2.

[0074] exist Figure 7 In the example shown, the central axis P of the infrared illumination surface 56 is tilted at an angle θ3 from the normal n. Furthermore, the optical axis O of the camera 42 is tilted at an angle θ4 from the normal n. Angles θ3 and θ4 can be the same or different. Preferably, the central axis P and the optical axis O are tilted in opposite directions relative to the normal n. That is, the direction in which the central axis P is tilted is 180° offset from the direction in which the optical axis O is tilted around the normal n.

[0075] By configuring the infrared illumination surface 56 and the camera 42 in this way, the incident efficiency of infrared (IR) light reflected from the electrode plate 7 onto the camera 42 can be improved, resulting in images with higher contrast. Consequently, the position of the electrode plate 7 can be checked with greater precision.

[0076] The embodiments of this disclosure have been described in detail above. The foregoing embodiments are merely specific examples of implementing this disclosure. The content of the embodiments does not limit the technical scope of this disclosure; various design changes, such as alterations, additions, and deletions of constituent elements, are possible without departing from the spirit of this disclosure as defined in the claims. New embodiments with design changes combine the effects of both combined embodiments and variations. In the foregoing embodiments, the phrases "in this embodiment" and "in this embodiment" are used to emphasize the possibility of such design changes; however, design changes are permitted even without such expressions. Any combination of the aforementioned constituent elements is also valid as a solution of this invention. The shading lines in the cross-sectional annotations of the drawings do not limit the material of the objects to be shaded.

[0077] The invention described above can be determined by the following items.

[0078] [Project 1]

[0079] One inspection method is to inspect the position of the electrode plate (7) in the laminate (2) to which the spacer (5) and the electrode plate (7) are bonded by adhesive from the spacer (5) side, including:

[0080] Infrared (IR) rays with peak wavelengths between 6.5 μm and 9.6 μm are irradiated from the spacer (5) to the laminate (2).

[0081] Infrared (IR) light reflected by the electrode plate (7) through the spacer (5) is captured by a camera (42) with sensitivity in the wavelength region of infrared (IR).

[0082] The position of the electrode plate (7) is detected based on the image captured by the camera (42).

[0083] [Example]

[0084] The following describes embodiments of the present invention, but these embodiments are merely illustrative of the invention and do not limit the scope of the invention in any way.

[0085] [Verification Experiment I: Verification of the wavelength range of infrared radiation]

[0086] Experiment I was conducted to verify the effects of the peak wavelength of infrared (IR) on camera capture and the state of stacked units.

[0087] Figure 8This is a schematic diagram of the inspection device 34 used in verification test I. In this verification test, the camera 42 is positioned directly above the laminate unit 2. The camera 42 has an imaging element 42a and a light-collecting lens 60. The light-collecting lens 60 is positioned between the laminate unit 2 and the imaging element 42a. Furthermore, the infrared irradiation section 40 is configured to irradiate infrared IR at an angle relative to the laminate unit 2. The structure of the infrared irradiation section 40 is the same as that of the infrared irradiation section 40 in the inspection device 34 of Embodiment 1 (see reference). Figure 4 (A) Furthermore, a laminated unit 2 is used, with the first electrode plate 8 (negative electrode plate) sandwiched between a first spacer 6 and a second spacer 10. Each spacer 5 is a heat-resistant adhesive spacer, having a substrate 14 made of PE, a heat-resistant agent layer 18 made of magnesium oxide laminated on both sides of the substrate 14, and an adhesive layer 16 made of PVDF laminated on each heat-resistant agent layer 18. Each spacer 5 is heated to 50°C and pressed against the first electrode plate 8.

[0088] At room temperature of 26°C, infrared IR rays of various peak wavelengths are irradiated onto the laminated unit 2 from the infrared irradiation section 40 for 1 second, and the laminated unit 2 is photographed by the camera 42. The infrared IR rays reaching the laminated unit 2 pass through the first spacer 6 and are reflected by the first electrode 8. The infrared IR rays reflected by the first electrode 8 pass through the light-collecting lens 60 and are imaged by the imaging element 42a. The peak wavelengths of the infrared IR rays are set to 6.5μm, 8.7μm, 8.9μm, 9.0μm, 9.2μm, 9.3μm, and 9.6μm. In addition, the surface temperature of the laminated unit 2 after 1 second of infrared IR irradiation is measured using a contact thermometer. The temperature of the infrared irradiation surface 56 is measured using a digital thermometer with a thermocouple attached to the surface of the infrared irradiation surface 56. Furthermore, changes in the state of the laminated unit 2, including the peeling of the spacer, are observed by visual inspection.

[0089] Figure 9 This is a graph showing the results of verification experiment I. (Example) Figure 9 As shown, it can be confirmed that when the laminate unit 2 is irradiated with infrared (IR) light with a peak wavelength of 6.5 μm to 9.6 μm, the position of the first electrode plate 8 can be checked from the first spacer 6 side. Furthermore, the surface temperature of the laminate unit 2 is below 28.0 °C, which is sufficiently low compared to the bonding temperature of the adhesive layer 16, which is 50 °C. Of course, no peeling of the spacer 5 was observed at any peak wavelength. Based on the above, it can be confirmed that when the peak wavelength of the infrared (IR) light is in the range of 6.5 μm to 9.6 μm, the reduction in the bonding strength between the spacer 5 and the electrode plate 7 can be suppressed, and the position of the electrode plate 7 can be detected.

[0090] Furthermore, the inventors of this invention have confirmed through visual observation that the spacer peels off when the peak wavelength of the infrared IR is less than 6.5 μm or greater than 9.6 μm. When the peak wavelength of the infrared IR is less than 6.5 μm, the temperature of the spacer 5 rises due to irradiation based on the infrared IR, reducing the adhesive strength of the adhesive layer 16. Since the surface temperature of the spacer 5 tends to rise as the wavelength of the infrared IR decreases, peeling of the spacer 5 is more likely to occur when the peak wavelength is less than 6.5 μm.

[0091] On the other hand, when the peak wavelength of infrared IR is higher than 9.6 μm, the temperature rise of spacer 5 is suppressed. However, the electrode plate 7 is heated by infrared IR irradiation, and the adhesive force of the adhesive layer 16 decreases due to the temperature rise of the electrode plate 7. When infrared IR reaches the electrode plate 7, electron vibration in the metal constituting the electrode plate 7 generates heat. As a result, the temperature of the electrode plate 7 rises. Furthermore, since the electrode plate 7 is covered by spacer 5, heat easily accumulates in the electrode plate 7, and the temperature of the electrode plate 7 rises in a relatively short time. Since the temperature of the electrode plate 7 tends to rise as the wavelength of infrared IR increases, the spacer 5 is more prone to peeling when the peak wavelength is higher than 9.6 μm.

[0092] [Verification Test II: Verification of Infrared Irradiation Unit and Camera]

[0093] Verification Experiment II was conducted to verify the shape of the infrared irradiation unit and the impact of the configuration of the infrared irradiation unit and the camera on the camera's shooting.

[0094] Figure 10 (A) is a schematic diagram of the inspection device 34 of Embodiment 1. Figure 10 Image (B) is obtained by the inspection device 34 of Example 1. The inspection device 34 of Example 1 is the same as the inspection device 34 used in Verification Test I (see [reference]). Figure 8 ).

[0095] Figure 10 (C) is a schematic diagram of the inspection device 34 of Example 2. Figure 10 Image (D) is the image obtained by the inspection device 34 of Embodiment 2. The inspection device 34 of Embodiment 2 is the same as the inspection device 34 described in Embodiment 1 (see [reference]). Figure 4 (A)).

[0096] Figure 10 (E) is a schematic diagram of the inspection device 34 of Embodiment 3. Figure 10 Image (F) is the image obtained by the inspection device 34 of Embodiment 3. The inspection device 34 of Embodiment 3 is the same as the inspection device 34 described in Embodiment 4 (see [reference]). Figure 7 ).

[0097] Figure 10 (G) is a schematic diagram of the inspection device 34 of Embodiment 4. Figure 10 (H) is the image obtained by the inspection device 34 of Embodiment 4. The inspection device 34 of Embodiment 4 is the same as the inspection device 34 described in Embodiment 3 (see [reference]). Figure 6 (A)).

[0098] In this evaluation test, the same stacked unit 2 as in Evaluation Test I was used. At room temperature of 26°C, infrared IR with a peak wavelength of 9.35 μm was irradiated onto the stacked unit 2 from the infrared irradiation unit 40 for 1 second, and the stacked unit 2 was photographed by the camera 42.

[0099] A camera 42 is positioned directly above the laminated unit 2, and infrared (IR) light is obliquely irradiated in the inspection device 34 of Embodiment 1 to obtain... Figure 10 The image shown in (B). On the other hand, in the inspection device 34 of Embodiment 2, where a camera 42 is arranged between the infrared irradiation unit 40 and the laminate unit 2, as shown in (B). Figure 10 As shown in (D), a higher contrast image is obtained compared to the inspection device 34 of Embodiment 1. This allows for a clearer distinction between the spacer 5 and the electrode plate 7. Furthermore, based on the results of Embodiment 2, it can be inferred that the inspection device 34 of Embodiment 2, i.e., the inspection device 34 that overlaps the through-hole 58 provided on the infrared irradiation surface 56 with the optical axis O of the camera 42, can obtain an image with a contrast as high as or greater than that of the inspection device 34 of Embodiment 2.

[0100] Furthermore, in the inspection device 34 of Embodiment 3, where the central axis P of the infrared irradiation surface 56 is inclined to the optical axis O of the camera 42, such as Figure 10 As shown in (F), an image with higher contrast than that obtained by the inspection apparatus 34 of Embodiment 1 and Embodiment 2 is obtained. Furthermore, in the inspection apparatus 34 of Embodiment 4, which has a parabolic infrared irradiation surface 56, as... Figure 10 As shown in (H), a high-contrast image is obtained that is equivalent to or higher than that of the inspection device 34 of Example 3.

[0101] Based on the above, it can be confirmed that image contrast is improved by irradiating infrared light IR from the back of the camera 42, and by the through-hole 58 superimposed on the infrared irradiation surface 56 and the optical axis O of the camera 42. Furthermore, it is confirmed that image contrast is improved by tilting the central axis P of the infrared irradiation surface 56 and the optical axis O of the camera 42 relative to the normal n of the stacked unit 2. Furthermore, it is confirmed that image contrast is improved by making the incident angle of infrared light IR irradiated from the first irradiation area 56a of the infrared irradiation surface 56 towards the stacked unit 2 different from the incident angle of infrared light IR irradiated from the second irradiation area 56b towards the stacked unit 2.

[0102] Industrial availability

[0103] This disclosure can be used in inspection apparatus, manufacturing apparatus for laminated electrodes, and inspection methods.

[0104] Explanation of reference numerals in the attached figures

[0105] 1 Manufacturing apparatus, 4 Stacking platform, 5 Spacer, 7 Electrode plate, 24 Transmission unit, 28 Camera, 32 Detection unit, 34 Inspection device, 40 Infrared irradiation unit, 42 Camera, 56 Infrared irradiation surface, 56a First irradiation area, 56b Second irradiation area, 58 Through hole, 100 Stacked electrode body.

Claims

1. An inspection device for inspecting the position of an electrode plate in a laminate bonded by an adhesive to a spacer and an electrode plate from the spacer side, wherein if the laminate is irradiated with infrared light, the adhesive force of the adhesive decreases due to the heat of the infrared light, the inspection device comprising: The infrared irradiation section irradiates the laminate with infrared light having a peak wavelength in the range of 6.5 μm to 9.6 μm from the spacer side. A camera, sensitive in the wavelength region of the infrared light, captures the infrared light reflected from the electrode plate after passing through the spacer; The detection unit detects the position of the electrode plate based on the image captured by the camera.

2. The inspection device according to claim 1, The infrared irradiation part has an infrared irradiation surface. The infrared irradiation surface has a through hole. Viewed from a first direction in which the infrared irradiation unit and the camera are arranged, the infrared irradiation unit and the camera are configured such that the through hole overlaps with the optical axis of the camera.

3. The inspection device according to claim 1 or 2, The infrared irradiation section has an infrared irradiation surface, which includes a first irradiation area that allows infrared rays to enter the laminate at a predetermined first incident angle, and a second irradiation area that allows infrared rays to enter the laminate at a second incident angle different from the first incident angle.

4. The inspection device according to claim 3, The infrared irradiation section has a parabolic infrared irradiation surface.

5. The inspection device according to claim 1 or 2, The infrared irradiation section has an infrared irradiation surface whose central axis is inclined relative to the normal of the laminate. The camera is configured such that its optical axis is tilted relative to the normal.

6. The inspection device according to claim 1 or 2, The camera is positioned in the infrared optical path, between the infrared irradiation part and the laminate. The infrared irradiation unit has an infrared irradiation surface that extends outward from the camera when viewed from a first direction in which the camera and the infrared irradiation unit are arranged.

7. An apparatus for manufacturing a stacked electrode body, comprising: A laminate consisting of a stacking platform, stacking spacers, and electrode plates bonded together with an adhesive. The transmission unit transmits the laminated body and releases it onto the lamination stage. The inspection apparatus according to any one of claims 1 to 6 inspects the position of the electrode plate in the laminate discharged from the transmission section; The stacked bodies are overlapped to create a stacked electrode body.

8. An inspection method for inspecting the position of the electrode plate in a laminate bonded by an adhesive from the spacer side, wherein if the laminate is irradiated with infrared light, the adhesive force of the adhesive decreases due to the heat of the infrared light, the inspection method comprising: Infrared radiation with a peak wavelength in the range of 6.5 μm to 9.6 μm is irradiated onto the laminate from the spacer side. A camera sensitive to the wavelength region of infrared light captures images of the infrared light reflected by the electrode plate through the spacer. The position of the electrode plate is detected based on the image captured by the camera.

Images