JP5814588B2 - Electrode position detection device and electrode position detection method - Google Patents

Description

  The present invention relates to an electrode position detection device and an electrode position detection method.

  In recent years, secondary batteries have been used in various products. The secondary battery includes a power generation element in which a positive electrode, a separator, and a negative electrode are stacked. In the power generation element, it is important that the positive electrode and the negative electrode are laminated through the separator without misalignment. This is because stacking misalignment causes deterioration of battery performance and battery life.

  Therefore, in order to prevent misalignment between the positive electrode and the negative electrode, a technique for laminating the positive electrode and the negative electrode at high speed and accurately by arranging the positive electrode in a bag-shaped separator and laminating the bag-shaped separator and the negative electrode. It has been proposed (see Patent Document 1).

Japanese Patent No. 3380935

  However, in the invention described in Patent Document 1, it is assumed that the positive electrode is accurately positioned in the separator. Therefore, even if the positive electrode is not actually positioned accurately, it is not confirmed in a subsequent process. In this case, there is a possibility that the battery is assembled and shipped as it is with the position of the positive electrode shifted from the separator. Improvement of quality assurance is desired.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an electrode position detection device and an electrode position detection method capable of detecting the position of an electrode with respect to a separator in an electrode packed in the separator.

The electrode position detection device of the present invention transports a packaged electrode formed by arranging an electrode in a bag-shaped separator from an electrode supply table to a stacking stage by a transport device, and has a polarity different from that of the electrode. An electrode position detecting device for detecting a position of the electrode arranged in the separator with respect to one packaged electrode placed on the electrode supply table when stacking with another electrode, A light projecting unit, a first light receiving unit, a second light projecting unit, a second light receiving unit, and a detection unit; The first light projecting means projects first light that passes through the separator and does not pass through the electrode to the electrode disposed in the separator formed in a bag shape. The first light receiving means is disposed on the opposite side of the first light projecting means with respect to the electrode, and receives the first light transmitted through the separator. A 2nd light projection means projects the 2nd light reflected on a separator. The second light receiving means receives the second light reflected by the separator. The detecting means detects the positions of the separator and the electrode based on the light reception results by the first light receiving means and the second light receiving means, and detects the relative position of the electrode with respect to the separator.

In the electrode position detection method of the present invention, a packed electrode formed by arranging an electrode in a bag-shaped separator is conveyed from an electrode supply table to a stacking stage by a conveying device, and has a polarity different from that of the electrode. An electrode position detection method for detecting a position of the electrode arranged in the separator with respect to one packaged electrode placed on the electrode supply table when stacking with another electrode, It includes a light projecting step, a first light receiving step, a second light projecting step, a second light receiving step and a detecting step. In the first light projecting step, first light that is transmitted through the separator and is not transmitted through the electrode is projected by the first light projecting unit on the electrode disposed in the separator formed in a bag shape. In the first light receiving step, the first light transmitted through the separator is received by the first light receiving unit disposed on the opposite side of the first light projecting unit with respect to the electrode. In the second light projecting step, the second light projecting means projects second light reflected on the separator. In the second light receiving step, the second light reflected by the separator is received by the second light receiving means. In the detection step, the positions of the separator and the electrode are detected by the detection means based on the light reception results in the first light receiving step and the second light receiving step, and the relative position of the electrode with respect to the separator is detected.

  According to the electrode position detection device and the electrode position detection method of the present invention, since the positions of both the separator and the electrode can be detected, it can be confirmed that the electrodes are appropriately arranged in the separator.

It is a perspective view showing the appearance of a lithium ion secondary battery. It is a disassembled perspective view of a lithium ion secondary battery. It is a top view of a negative electrode and a packaged positive electrode. It is a top view which shows a mode that the negative electrode was piled up on the packaged positive electrode. It is a schematic plan view which shows a sheet | seat lamination apparatus. It is a perspective view which shows a sheet | seat lamination apparatus. It is a front view of the positive electrode supply table seen in the arrow direction of FIG. It is a top view of a positive electrode supply table. It is a figure for demonstrating the lamination | stacking operation | movement of the negative electrode and bag-packed positive electrode by a lamination | stacking robot. It is a figure for demonstrating the lamination | stacking operation | movement of the negative electrode and bag-packed positive electrode by a lamination | stacking robot. It is a figure for demonstrating the lamination | stacking operation | movement of the negative electrode and bag-packed positive electrode by a lamination | stacking robot. It is a conceptual diagram which shows a mode that the position of the positive electrode in a packaged positive electrode is confirmed. It is a conceptual diagram which shows a mode that the position of a separator is confirmed. It is a conceptual diagram which shows a mode that the position of a positive electrode is determined. It is the schematic which shows the permeation | transmission characteristic of a separator. It is the schematic which shows an example of a mode that the turning has generate | occur | produced in the separator.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. In addition, the dimension ratio of drawing is exaggerated on account of description, and may differ from an actual ratio.

  The present invention relates to an electrode position detecting device applied to a part of a manufacturing process of a secondary battery. Before describing an electrode position detection apparatus according to an embodiment of the present invention, a sheet stacking apparatus that is a structure for assembling a battery structure and a power generation element of the battery will be described.

(battery)
First, a lithium ion secondary battery (laminated battery) formed by a sheet laminating apparatus will be described with reference to FIG. FIG. 1 is a perspective view showing the appearance of a lithium ion secondary battery, FIG. 2 is an exploded perspective view of the lithium ion secondary battery, FIG. 3 is a plan view of a negative electrode and a packaged positive electrode, and FIG. It is a top view which shows a mode that it piled up.

  As shown in FIG. 1, the lithium ion secondary battery 10 has a flat rectangular shape, and the positive electrode lead 11 and the negative electrode lead 12 are led out from the same end of the exterior material 13. A power generation element (battery element) 15 in which a charge / discharge reaction proceeds is accommodated in the exterior member 13. As shown in FIG. 2, the power generation element 15 is formed by alternately stacking the packaged positive electrode 20 and the negative electrode 30.

  As shown in FIG. 3A, the packaged positive electrode 20 includes a positive electrode 24 in which a positive electrode active material layer 22 is formed on both surfaces of a sheet-like positive electrode current collector, and is sandwiched between separators 40. The two separators 40 are joined to each other by a joining portion 42 at an end portion, and are formed in a bag shape. In the positive electrode 24, the tab portion 26 is pulled out from the bag of the separator 40. In the positive electrode 24, the positive electrode active material layer 22 is formed in a portion other than the tab portion 26.

  As shown in FIG. 3B, the negative electrode 30 is formed by forming negative electrode active material layers 32 on both surfaces of a very thin sheet-like negative electrode current collector. In the negative electrode 30, a negative electrode active material layer 32 is formed in a portion other than the tab portion 34.

  When the negative electrode 30 is stacked on the packaged positive electrode 20, the result is as shown in FIG. As shown in FIG. 4, the negative electrode active material layer 32 is formed to be slightly larger than the positive electrode active material layer 22 of the positive electrode 24 in plan view.

  In addition, since the method itself which manufactures a lithium ion secondary battery by laminating | stacking the packaged positive electrode 20 and the negative electrode 30 by turns is a general manufacturing method of a lithium secondary battery, detailed description is abbreviate | omitted.

(Sheet stacking device)
Next, the sheet | seat lamination apparatus for assembling the said electric power generation element 15 is demonstrated.

  5 is a schematic plan view showing the sheet laminating apparatus, FIG. 6 is a perspective view showing the sheet laminating apparatus, FIG. 7 is a front view of the positive electrode supply table viewed in the direction of the arrow in FIG. 6, and FIG. It is.

  As shown in FIGS. 5 and 6, the sheet stacking apparatus 100 includes a stacking robot 110, a positive electrode supply table 120, a negative electrode supply table 130, a stacking stage 140, a storage unit 150, and a control unit 160. The stacking robot 110, the positive electrode supply table 120, the negative electrode supply table 130, and the stacking stage 140 are controlled by the control unit 160. The control program and various data of the control unit 160 are stored in the storage unit 150.

  The stacking robot 110 alternately stacks the packaged positive electrode 20 and the negative electrode 30 to form a power generation element (laminated body) 15. The stacking robot 110 includes an L-shaped arm 112 and first and second suction hands 114 and 116 provided at end portions of the L-shaped arm 112. The L-shaped arm 112 rotates a predetermined angle in the horizontal direction, for example, 90 degrees in this embodiment. Further, the L-shaped arm 112 can move a predetermined amount in the vertical direction. The first suction hand 114 is provided at one end of the L-shaped arm 112 and holds or releases the packaged positive electrode 20 by suction. The second suction hand 116 is provided at the other end of the L-shaped arm 112 and holds or releases the negative electrode 30 by suction.

  The positive electrode supply table 120 is a table for delivering the packaged positive electrode 20 to the L-shaped arm 112. The positive electrode supply table 120 receives and places the packed positive electrodes 20 created in the previous process and transported by the suction conveyor 60 one by one. The positive electrode supply table 120 is also an adsorption conveyor, and adsorbs the packed positive electrode 20 from which the negative pressure from the adsorption conveyor 60 is released, carries it to the approximate center, and fixes it by the negative pressure. Further, the positive electrode supply table 120 can be moved and rotated in the planar direction so that the planar position of the packaged positive electrode 20 can be adjusted. The positive electrode supply table 120 is provided on, for example, an XY stage 122, and the planar position is adjusted by the XY stage 122 moving in the X and Y directions or rotating in the planar direction. The XY stage 122 is moved and rotated in the plane direction by three motors.

  The positive electrode supply table 120 is narrower than the suction conveyor 60 and is configured so that the side of the packaged positive electrode 20 protrudes. Although not shown in FIGS. 5 and 5, transparent support bases 124 are provided on both sides of the positive electrode supply table 120 as shown in FIGS. 7 and 8. The support table 124 supports the end of the packaged positive electrode 20 protruding from the positive electrode supply table 120. A clamper 126 is provided at a position corresponding to the support base 124. The clamper 126 is fixed by sandwiching the end portion of the packed positive electrode 20 together with the support base 124. Both the support base 124 and the clamper 126 are movable, and when the packaged positive electrode 20 is placed on the positive electrode supply table 120, the packaged positive electrode 20 is attached to the packaged positive electrode 20 so as to support and fix the end of the packaged positive electrode 20. approach.

  A light source 70 is disposed below the positive electrode supply table 120 and a camera 80 is disposed above. The light source 70 is installed below the transparent support base 124 and irradiates light to the end of the packaged positive electrode 20. The irradiated light is light having a wavelength that passes through the separator 40 at a predetermined transmittance or higher and does not pass through the positive electrode 24 (transmits at a predetermined transmittance or lower). The camera 80 receives light transmitted from the light source 70 and blocked by the positive electrode 24 while passing through the separator 40, and images the position of the positive electrode 24. That is, the position of the positive electrode 24 is imaged based on the shadow of the positive electrode 24. Based on the position of the positive electrode 24 imaged by the camera 80, the horizontal position of the positive electrode 24 (packed positive electrode 20) is adjusted. By this adjustment, the suction hand 114 can pick up the packaged positive electrode 20 in which the position of the positive electrode 24 is accurately positioned every time.

  5 and 6, the negative electrode supply table 130 is a table for delivering the negative electrode 30 to the L-shaped arm 112. The negative electrode supply table 130 receives and places the negative electrodes 30 created in the previous process and transported by the suction conveyor 62 one by one. The negative electrode supply table 130 is also an adsorption conveyer, and adsorbs the negative electrode 30 from which the negative pressure from the adsorption conveyer 62 is released, carries it to approximately the center, and fixes it by the negative pressure. When the negative electrode 30 is sucked by the first suction hand 116, the negative electrode supply table 130 releases the suction. Further, the negative electrode supply table 130 can be moved and rotated in the planar direction so that the planar position of the negative electrode 30 can be adjusted. The negative electrode supply table 130 is provided on, for example, an XY stage 132, and the plane position is adjusted by the XY stage 132 moving in the X and Y directions or rotating in the plane direction. The XY stage 132 is moved and rotated in the plane direction by three motors.

  A light source 72 and a camera 82 are arranged above the negative electrode supply table 130. The light source 72 irradiates the negative electrode 30 with light having a wavelength reflected by the negative electrode 30. The camera 82 receives the light projected from the light source 72 and reflected by the negative electrode 30, and images the position of the negative electrode 30. In the negative electrode supply table 130, the horizontal position of the negative electrode 30 is adjusted based on the position of the negative electrode 30 captured by the camera 82. By this adjustment, the suction hand 116 can pick up the accurately positioned negative electrode every time.

  The stacking stage 140 is disposed on the mounting portion 142 for mounting the pallet on which the packaged positive electrode 20 and the negative electrode 30 are alternately stacked, the driving portion 144 for moving the mounting portion 142 up and down, and the peripheral portion of the mounting portion 142. And four clampers 146.

  The mounting unit 142 holds the stacked body 15 until a predetermined number of the stacked positive electrodes 20 and negative electrodes 30 are stacked and the power generation element 15 is completed. When the power generation element 15 is completed, the power generation element 15 is delivered to the conveyor 64. The drive unit 144 adjusts the height of the placement unit 142. Specifically, the packaged positive electrode 20 and the negative electrode 30 are alternately stacked, and placed according to the progress of the stacking so that the height of the top surface of the stacked body 15 does not change even if the height of the stacked body 15 varies. The position of the part 142 is lowered. Thereby, the stacking robot 110 can stack the power generating elements 15 only by repeating the same operation regardless of the progress of the stacking. The clamper 146 fixes the four corners of the laminated body 15 every time the negative electrode 30 or the packaged positive electrode 20 is laminated so that the laminated body 15 is not displaced. Since the height of the mounting portion 142 is adjusted to be lower as the stacking progresses, the clamper 146 can repeat clamping with the same stroke every time.

(Lamination operation)
According to the sheet laminating apparatus 100 configured as described above, the packed positive electrode 20 and the negative electrode 30 placed on the positive electrode supply table 120 and the negative electrode supply table 130 after being adjusted in position are picked up by the laminating robot 110 and laminated. Alternately provided to the stage 140. Hereinafter, the stacking operation of the sheet stacking apparatus 100 will be described with reference to FIGS.

  9-11 is a figure for demonstrating the lamination | stacking operation | movement of the negative electrode by a lamination | stacking robot, and a packaged positive electrode. In the following, the operation when the packaged positive electrode 20 is stacked on the stacking stage 140 by the stacking robot 110 will be described.

  As shown in FIG. 9A, the packaged positive electrode 20 and the negative electrode 30 are placed on the lamination stage 140, and the suction hand 114 is positioned above the lamination stage 140. The negative electrode 30 is disposed in the uppermost layer of the stacked positive electrode 20 and negative electrode 30, and the suction hand 114 holds the packed positive electrode 20 by suction. On the other hand, the suction hand 116 is located above the negative electrode supply table 130. The negative electrode 30 is placed on the negative electrode supply table 130.

  Subsequently, the L-shaped arm 112 of the stacking robot 110 is lowered by a predetermined amount (see FIG. 9B). As the L-shaped arm 112 is lowered, the suction hand 116 and the suction hand 114 are lowered onto the negative electrode supply table 130 and the stacking stage 140, respectively. At this time, negative pressure acts on the bottom surface of the suction hand 116, and the suction hand 116 sucks and holds the negative electrode 30. On the other hand, the negative pressure is released from the suction hand 114 and the packaged positive electrode 20 is released.

  Subsequently, the L-shaped arm 112 of the stacking robot 110 is raised by a predetermined amount (see FIG. 10C). As the L-shaped arm 112 rises, the suction hand 116 picks up the negative electrode 30 from the table 130. Further, the suction hand 116 and the suction hand 114 move on the negative electrode supply table 130 and above the stacking stage 140.

  Subsequently, the L-shaped arm 112 of the stacking robot 110 rotates by a predetermined amount (see FIG. 10D). When the L-shaped arm 112 is rotated 90 degrees in the horizontal direction, the suction hand 116 is positioned above the stacking stage 140 and the suction hand 114 is positioned above the table 120.

  Subsequently, the L-shaped arm 112 of the stacking robot 110 is lowered by a predetermined amount (see FIG. 11E). As the L-shaped arm 112 descends, the suction hand 116 and the suction hand 114 reach the stacking stage 140 and the positive electrode supply table 120, respectively. At this time, the negative pressure of the suction hand 116 is released, and the suction hand 116 releases the negative electrode 30 on the uppermost surface of the stacked body on the stacking stage 140. On the other hand, a negative pressure is generated on the bottom surface of the suction hand 114, and the suction hand 114 sucks and holds the packaged positive electrode 20 on the table 120.

  Subsequently, the L-shaped arm 112 of the stacking robot 110 is raised by a predetermined amount (see FIG. 11F). As the L-shaped arm 112 rises, the suction hand 116 moves above the stacking stage 140. On the other hand, the suction hand 114 picks up the packed positive electrode 20 from the table 120.

  Subsequently, the L-shaped arm 112 of the stacking robot 110 rotates by a predetermined amount. When the L-shaped arm 112 is rotated by −90 degrees in the horizontal direction, the suction hand 116 is positioned above the table 130 and the suction hand 114 is positioned above the stacking stage 140 (FIG. 9 ( A)).

  By repeating the above operation, the packed positive electrode 20 and the negative electrode 30 are alternately stacked on the stacking stage 140. By laminating a predetermined number of the packed positive electrode 20 and the negative electrode 30, a laminate as the power generation element 15 is formed.

(Electrode position detector)
Next, the electrode position detection apparatus 200 applied to the sheet laminating apparatus 100 will be described.

  Returning to FIG. 5 and FIG. 6, the configuration of the electrode position detection apparatus 200 will be described.

  The electrode position detection apparatus 200 includes light sources 70 and 74, a camera 80, and a control unit 160. The light sources 70 and 74 and the camera 80 are each connected to the control unit 160, and the operation is controlled by the control unit 160. The electrode position detection device 200 includes a configuration common to the above-described sheet stacking device 100.

  The light source 70 is installed below the positive electrode supply table 120 as a first light projecting unit. The camera 80 is installed as the first and second light receiving means on the side opposite to the light source 70 with respect to the packaged positive electrode 20. The camera 80 images the positive electrode 24 in the packaged positive electrode 20. The light source 70 projects light (first light) having a wavelength that passes through the separator 40 and does not pass through the positive electrode 24 (reflected or absorbed), for example, red light, toward the packaged positive electrode 20. The light from the light source 70 passes through the transparent support 124 and is projected onto the end of the packaged positive electrode 20. Since the central portion of the packaged positive electrode 20 is hidden by the positive electrode supply table 120, the light from the light source 70 is not irradiated.

  The light source 74 is disposed on the same side as the camera 80 with respect to the packaged positive electrode 20 as the second light projecting means. The light source 74 projects light having a wavelength (second light) reflected by the separator 40 toward the packaged positive electrode 20, for example, white light. It is known that the longer the wavelength of light, the higher the transmittance, but the transmittance varies depending on the material. Based on the material of the separator 40, the wavelength of the light to be projected needs to be set as appropriate. Details on how to set the wavelength of the light to be projected will be described later.

  The control unit 160 detects the positions of the positive electrode 24 and the separator 40 based on the image captured by the camera 80 as detection means. Hereinafter, an operation (electrode position detection method) of the electrode position detection device 200 when detecting the position of the positive electrode 24 will be described.

  12 is a conceptual diagram showing how to check the position of the positive electrode in the packaged positive electrode, FIG. 13 is a conceptual diagram showing how to check the position of the separator, and FIG. 14 is a conceptual diagram showing how to determine the position of the positive electrode. is there.

  First, the packed positive electrode 20 is placed on the positive electrode supply table 120, the end of the packed positive electrode 20 is supported by a transparent support base 124, and is fixed by a clamper 126. After fixing, the electrode position detection device 200 projects light by the light sources 70 and 74 before the packed positive electrode 20 is sucked by the suction hand 114. The light projection is performed sequentially rather than simultaneously. For example, light projection by the light source 70 is performed first.

  The projected light passes through the end of the separator 40 and does not pass through the positive electrode 24. The camera 80 receives light that has passed through the separator 40. That is, the camera 80 receives light in which the portion of the positive electrode 24 is shaded via the positive electrode 24. The position of the positive electrode 24 can be detected by detecting the shadow outline. However, since the light is not originally transmitted through the portion where the positive electrode 24 is hidden by the positive electrode supply table 120, the position of the positive electrode 24 cannot be detected. For example, as shown in a colored manner in FIG. 12, the shape and position of the end of the positive electrode 24 are confirmed.

  When an image as shown in FIG. 12 is obtained by the camera 80, the control unit 160 analyzes the image and specifies the side of the positive electrode 24 in the range indicated by the double arrow in the figure. The specified side is extended to specify the position of the entire side of the positive electrode 24. Although the positive electrode 24 has the tab part 26, as shown in FIG. 12, the edge of the coating part in which the active material layer 22 was formed is specified. Therefore, the positive electrode 24 in which the position of the entire side is specified is specified as a rectangle as shown in FIG. The position information of the specified side of the positive electrode 24 is stored in the storage unit 150.

  Subsequently, the light source 74 projects light onto the packaged positive electrode 20. The projected light is reflected by the separator 40 and received by the camera 80. The camera 80 receives the entire image of the separator 40. For example, as shown in FIG. 13, the position of the separator 40 is confirmed. When an image as shown in FIG. 13 is obtained by the camera 80, the control unit 160 analyzes the image and specifies the side of the separator 40 in the range indicated by the double arrow in the figure. The position information of the specified side of the separator 40 is stored in the storage unit 150.

  The control unit 160 reads the position information of the sides of the separator 40 and the positive electrode 24 from the storage unit 150 and confirms the position of the positive electrode 24 with respect to the position of the separator 40. For example, as shown in FIG. 14, the control unit 160 superimposes the positions of the sides of the separator 40 and the positive electrode 24, and measures the distance between the positions indicated by the double arrows. Here, the superposed positive electrode 24 is only a portion included in the separator 40 without the tab portion 26. And it is determined whether the position of the positive electrode 24 is normal or abnormal by determining whether or not the measured distance is within a predetermined range. The predetermined range is set in advance as a range of distances from each side of the separator 40 and is appropriately determined according to the standard of the packaged positive electrode 20 or the like. When the control unit 160 finds that the position of at least one side of the positive electrode 24 is not within the predetermined range with respect to the position of the side of the separator 40, the control unit 160 discharges the found packed positive electrode 20 by the stacking robot 20, It can be incorporated into the power generation element 15 or stored in the storage unit 150 and discharged as a defective product in a later process.

  As described above, in the present embodiment, the position of the positive electrode 24 itself arranged in the separator 40 formed in a bag shape can be detected, and the position relative to the separator 40 can be detected. Therefore, it can be reliably inspected whether the relative position is within the allowable range, that is, whether or not the positive electrode 24 is accurately positioned in the separator 40. As a result, it is possible to prevent the power generation element 15 from being formed and shipped while the positive electrode 24 that has been misaligned is packed in the separator 40. Since the position of the separator 40 is also detected, the quality of the position of the positive electrode 24 can be determined based on the relative positional relationship with the separator 40.

  Further, the camera 80 can receive light from both the light source 70 and the light source 74 in common. Therefore, it is not necessary to prepare a camera for each of the light sources 70 and 74, and equipment costs can be reduced.

  In addition, in the above embodiment, a part of the side of the positive electrode 24 is detected, and the entire side is calculated from the detected side. Therefore, although the part of the positive electrode 24 is hidden by the positive electrode supply table 120 and the total length of the side of the positive electrode 24 cannot be detected optically, the contour of the positive electrode 24 can be specified.

  Next, the wavelength of light to be projected will be described.

  FIG. 15 is a schematic view showing the transmission characteristics of the separator. In FIG. 15, the horizontal axis indicates the light wavelength (nm), and the vertical axis indicates the light transmittance (%).

  FIG. 15 shows the transmission characteristics of three types of separators, that is, a polypropylene separator, a polyethylene separator, and a ceramic separator. The polypropylene separator and the polyethylene separator are polymer skeletons formed of polypropylene and polyethylene, respectively. The ceramic separator is a polypropylene base material coated with a porous film formed by bonding ceramic particles such as silica, alumina, zirconium oxide, titanium oxide and a binder.

  Referring to FIG. 15, the separator 40 has a different transmission tendency depending on the material. However, for any material, it can be seen that the longer the wavelength, the higher the transmittance. In the above embodiment, when the positive electrode 24 is detected, it is necessary to project light having a wavelength that passes through the separator 40 from the light source 70. Although depending on the sensitivity of the camera 80, it is preferable that light having a wavelength such that at least the transmittance of the separator is 50% or more is projected from the light source 70. When the transmittance is 50% or more, the positive electrode 24 can be detected by reliably transmitting the separator 40.

  The positive electrode 24 is made of a metal such as aluminum or copper, and therefore hardly transmits light. Accordingly, there is no particular upper limit as long as even the separator 40 has a wavelength that allows transmission.

  As described above, the wavelength of light to be projected can be set based on the transmittance with respect to the separator 40 regardless of the material of the separator 40. That is, the lower limit of the wavelength can be set by the transmittance (50% or more) with respect to the separator 40.

  For example, when the ceramic separator having the transmission characteristics shown in FIG. 15 is employed, light having a wavelength of about 1300 nm or more, for example, near infrared light can be used. Ceramic separators are less permeable to light than polypropylene separators and polyethylene separators, but can be transmitted by using near infrared light.

  The light emitted from the light source 74 is for detecting the exposed separator 40. Therefore, the light source 74 irradiates light that does not pass through the separator 40 so much, for example, light having a wavelength with a transmittance of 50% or less.

(Modification)
In the above embodiment, the electrode position detection device 200 detects the position of the positive electrode 24 for the packaged positive electrode 20 placed on the positive electrode supply table 120. However, the present invention is not limited to this. In the process of manufacturing the secondary battery 10, the electrode detection by the electrode position detection device 200 can be applied to any process as long as the packaged positive electrode 20 is formed. For example, the position of the positive electrode 24 relative to the separator 40 may be detected immediately after the positive electrode 24 is sandwiched between two separators 40 and packed in a bag.

  Moreover, in the said embodiment, the form where the positive electrode 24 was packed in the separator 40 as the packaged positive electrode 20 was demonstrated. However, the negative electrode 30 may be packaged. In this case, the position of the negative electrode with respect to the separator is detected for the packed negative electrode as the packed electrode.

  Moreover, in the said embodiment, the quality of the relative position of the positive electrode 24 was determined by whether the position of the side of the positive electrode 24 was in a predetermined range on the basis of the position of the side of the separator 40. However, the reference for evaluating the relative position of the positive electrode 24 is not limited to this. For example, the respective corners (four corners) are calculated from the positions of the sides of the separator 40 and the positive electrode 24, the respective central positions are calculated from the average positions of the corners, and the positions of the positive electrodes 24 are determined based on the deviation between the central positions. May be evaluated.

  In the embodiment, the light source 70 is provided at a position facing the camera 80. However, the positional relationship between the light source 70 and the camera 80 is not limited to this. The light source 70 and the camera 80 may be provided on the same side with respect to the packaged positive electrode 20. In this case, the light emitted from the light source 70 passes through the separator 40 and does not pass through the positive electrode 24 but is captured by the camera 80. That is, the camera 80 images the positive electrode 24 itself, not the shadow of the positive electrode 24.

  In the above embodiment, the light from both the light sources 70 and 74 is received by the single camera 80. However, each of the light sources 70 and 74 may be provided with a light receiving camera. In this case, for example, the light sources 70 and 74 can be arranged on the same side or the design can be changed.

  In the above embodiment, as shown in FIG. 1, the case where the positive electrode 11 and the negative electrode lead 12 are led out from the same end of the exterior member 13 has been described. However, it is not limited to this. The positive electrode lead 11 and the negative electrode lead 12 may be led out from opposite ends, for example. In this case, when forming the power generation element 15 of the secondary battery 10, the negative electrode 30 and the packaged positive electrode 20 are laminated so that the tab portions 26 and 34 are opposite to each other.

(Detection of separator turning)
In the above embodiment, the relative position of the positive electrode 24 with respect to the separator 40 is detected. However, the camera 80 also images the separator 40 itself. Accordingly, whether or not the separator 40 is normal may be determined based on the imaging result of the separator 40 itself.

  FIG. 16 is a schematic diagram illustrating an example of a state where the separator is turned up.

  As shown in FIG. 16, the control unit 160 can detect that the separator 40 is abnormal when the lower left corner of the separator 40 is turned over.

  The occurrence of turning can be detected as follows. The controller 160 irradiates light from the light source 74 and receives light reflected by the separator 40 by the camera 80. The control unit 160 analyzes the image picked up by the camera 80 and distinguishes the separator 40 that looks white and the positive electrode 24 that looks black. For example, the positive electrode 24 is detected based on a difference in image brightness. When the black positive electrode 24 is detected in a range where the separator 40 should be, it can be detected that the separator 40 is turned over and the positive electrode 24 is exposed.

  The detection of turning up of the separator 40 can be performed simultaneously with the determination of the relative position of the positive electrode 24 with respect to the separator 40.

  With the above-described configuration, the turning of the separator 40 can also be detected, and the defect of the packed positive electrode 20 can be detected with higher accuracy.

(Joint detection)
In the above embodiment, the relative position of the positive electrode 24 with respect to the separator 40 is detected. In addition, the position of the joint portion 42 of the separator 40 may be evaluated.

  When the separator 40 is formed in a bag shape, the end sides are joined by, for example, heat welding. At this time, as shown in FIG. 3B, the joining portion 42 is formed. The joining portion 42 that joins the separators 40 has different physical properties from the original separator 40, and the light transmittance is also different from the portions other than the joining portions 42. The transmittance of the joint portion 42 is lower than that of the other separators 40. Therefore, by adjusting the wavelength of light projected from the light source 70, the position of the joint portion 42 can also be detected when the position of the positive electrode 24 is detected.

  The detected position of the joining portion 42 can be evaluated by comparing with the position of the separator 40 detected in the above embodiment. That is, as in the case of the positive electrode 24, the distance of the corresponding joint portion 42 is calculated based on the position of each side of the separator 40. If the calculated distance is within a predetermined range, the position of the joint portion 42 is normal. If it is out of range, it is determined to be abnormal.

10 Secondary battery,
15 power generation elements,
20 Packed positive electrode,
22 positive electrode active material layer,
24 positive electrode,
26 Tab part,
30 negative electrode,
32 negative electrode active material layer,
34 Tab part,
40 separator,
42 joints,
60, 62, 64 suction conveyor,
70, 72, 74 light source,
80, 82 cameras,
100 sheet laminating device,
110 stacking robot,
112 L-shaped arm,
114, 116 suction hand,
120 positive electrode supply table,
122 XY stage,
124 support base,
126 Clamper,
130 negative electrode supply table,
132 XY stage,
140 stacking stage,
142 mounting section,
144 drive unit,
146 Clamper,
150 storage unit,
160 control unit,
200 Electrode position detection device.

Claims (9)

When the electrode packed in the bag-shaped separator is disposed, the packed electrode is transported from the electrode supply table to the stacking stage by the transport device, and stacked with another electrode having a different polarity from the electrode, An electrode position detection device for detecting the position of the electrode arranged in the separator for one of the packaged electrodes placed on an electrode supply table,
To the electrodes disposed within the separator, the first light projecting means passes through the separator, projecting the first light not transmitted through the electrode,
A first light receiving means disposed on the opposite side of the first light projecting means with respect to the electrode, and receiving the first light transmitted through the separator;
Second light projecting means for projecting second light reflected on the separator;
Second light receiving means for receiving the second light reflected by the separator;
Detecting means for detecting positions of the separator and the electrode based on light reception results by the first light receiving means and the second light receiving means, and detecting a relative position of the electrode with respect to the separator;
An electrode position detecting device having When the electrode packed in the bag-shaped separator is disposed, the packed electrode is transported from the electrode supply table to the stacking stage by the transport device, and stacked with another electrode having a different polarity from the electrode, An electrode position detection device for detecting the position of the electrode arranged in the separator for one of the packaged electrodes placed on an electrode supply table,
To the electrodes disposed within the separator, the first light projecting means passes through the separator, projecting the first light not transmitted through the electrode,
First light receiving means for receiving the first light transmitted through the separator;
Second light projecting means for projecting second light reflected on the separator;
Second light receiving means for receiving the second light reflected by the separator;
Based on the light reception result by the first light receiving means and the second light receiving means detects the position of the separator and the electrodes, have a, a detecting means for detecting the relative position of the electrode with respect to the separator,
The first light projecting unit and the second light projecting unit are disposed on opposite sides of each other via the electrode,
The first light receiving means and the second light receiving means are realized by a common light receiving device,
An electrode position detection device in which the position of the electrode is detected based on a shadow of the first light blocked by the electrode. A first light projecting means for projecting a first light that passes through the separator and does not pass through the electrode, with respect to the electrode disposed in the bag-shaped separator;
First light receiving means for receiving the first light transmitted through the separator;
Second light projecting means for projecting second light reflected on the separator;
Second light receiving means for receiving the second light reflected by the separator;
An electrode position detecting device comprising: a detecting unit that detects positions of the separator and the electrode based on a light reception result by the first light receiving unit and the second light receiving unit, and detects a relative position of the electrode with respect to the separator. Because
The bag-shaped separator is formed by joining the edges of two separators with a joint portion,
The detection means detects the joint portion based on a light reception result by the first light receiving means, and determines whether the position of the joint portion is good based on a relative position of the joint portion with respect to the separator. Equipment . The electrode position detection device according to any one of claims 1 to 3, wherein the detection unit determines whether the relative position of the electrode with respect to the separator is good or bad. The electrode position detection device according to any one of claims 1 to 4, wherein the separator is a ceramic separator, and the first light is near-infrared light. It said detection means detects the edge of the separator and the electrode, based on the position of each side, electrode position according to any one of claims 1 to 5 for detecting the position of the electrode relative to the separator Detection device. The electrode position detection device according to any one of claims 1 to 6 , wherein the detection unit inspects whether or not the bag-shaped separator is turned based on a light reception result by the second light reception unit.   The electrode position detecting device according to any one of claims 1 to 7, wherein the first light projected by the first light projecting unit is light having a wavelength at which the transmittance of the separator is 50% or more. . When the electrode packed in the bag-shaped separator is disposed, the packed electrode is transported from the electrode supply table to the stacking stage by the transport device, and stacked with another electrode having a different polarity from the electrode, An electrode position detection method for detecting the position of the electrode arranged in the separator with respect to one packaged electrode placed on an electrode supply table,
To the electrodes disposed within the separator, the first light projecting means, a first light projecting step of projecting the first light not transmitted through the separator, passes through the electrode,
A first light receiving step of receiving the first light transmitted through the separator by a first light receiving means disposed on the opposite side of the first light projecting means with respect to the electrode;
A second light projecting step of projecting the second light reflected by the separator by the second light projecting means;
A second light receiving step of receiving the second light reflected by the separator by a second light receiving means;
A detection step of detecting a position of the separator and the electrode based on a light reception result in the first light receiving step and the second light receiving step by a detecting unit, and detecting a relative position of the electrode with respect to the separator;
An electrode position detection method comprising: