JP2012227129A - Electrode lamination device and electrode lamination method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrode lamination device and an electrode lamination method which properly laminate an electrode bagged in a separator on other electrodes.SOLUTION: An electrode lamination device 100 includes: detection means 200 for detecting a position of a first electrode 24 for a bagged electrode 20 where the first electrode 24 is placed in a separator 40 formed into a bag shape; and lamination means 112, 122 for laminating the first electrode 24 on a second electrode 30 having a polarity different from the first electrode 24 based on the detected position of the first electrode 24.

Description

  The present invention relates to an electrode stacking apparatus and an electrode stacking method.

  In recent years, secondary batteries have been used in various products. The secondary battery includes a battery element in which a positive electrode, a separator, and a negative electrode are stacked. In the battery 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). In this technique, the separator and the negative electrode are formed in substantially the same size, and the negative electrode and the positive electrode in the separator can be aligned by aligning and laminating the outer sides.

Japanese Patent No. 3380935

  However, in the invention described in Patent Document 1, although it is described that the outer sides of the separator and the negative electrode are aligned, a method for specifically aligning is not shown. In the first place, it is difficult to align the outer shapes, and if the outer shapes cannot be aligned well, there is no guarantee that the positive electrode and the negative electrode are accurately aligned and stacked. In addition, when trying to align the outer shape accurately, man-hours increase, and high-speed stacking cannot be performed, resulting in a reduction in production tact.

  Further, in the invention described in Patent Document 1, when the bag-shaped separator and the negative electrode are different in size, the alignment of the positive electrode and the negative electrode cannot be guaranteed.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide an electrode laminating apparatus and an electrode laminating method capable of appropriately laminating an electrode packed in a separator on another electrode.

  The electrode laminating apparatus of the present invention has a detecting means and a laminating means. The detection means detects the position of the first electrode with respect to the packaged electrode in which the first electrode is disposed in the separator formed in a bag shape. The stacking unit stacks the first electrode on the second electrode having a polarity different from that of the first electrode based on the detected position of the first electrode.

  The electrode lamination method of the present invention includes a detection step and a lamination step. In the detection step, the position of the first electrode is detected with respect to the packaged electrode in which the first electrode is disposed within the bag-shaped separator. In the stacking step, the first electrode is stacked on the second electrode having a polarity different from that of the first electrode based on the detected position of the first electrode.

  According to the electrode stacking apparatus and the electrode stacking method of the present invention, the position of the first electrode hidden behind the separator is detected, and the packed electrode is stacked on the second electrode based on the detected position of the first electrode. Therefore, the packaged electrode can be stacked on the second electrode in consideration of the position of the first electrode, so that the first electrode and the second electrode can be accurately aligned and stacked.

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 the position of the detected positive electrode. It is a conceptual diagram which shows a mode that the position of a negative electrode is determined. It is a figure which shows the camera on a lamination | stacking stage. It is a figure which shows the structure of a camera. 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 the mode of the positive electrode by which the position of the edge was specified. It is a conceptual diagram which shows a mode that the position of a negative electrode is confirmed. It is a conceptual diagram which shows the mode of the negative electrode by which the position of the edge was specified. It is a conceptual diagram which shows the relative position of a positive electrode and a negative electrode. It is the schematic which shows the permeation | transmission characteristic of a 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 material. 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, a sheet laminating apparatus (electrode laminating apparatus) for assembling the power generating element 15 will be described.

  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 more and does not pass through the positive electrode 24. 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 or absorbed by the negative electrode 30. The camera 82 receives the light projected from the light source 72 and reflected by the negative electrode 30, or the light reflected around without being absorbed 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 a light source 70, a camera 80, an XY stage 122, and a control unit 160. The light source 70 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 light projecting means. The camera 80 is installed on the side opposite to the light source 70 with respect to the packaged positive electrode 20 as a light receiving means. The camera 80 images the positive electrode 24 in the packaged positive electrode 20. The light source 70 projects 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. 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 part 160 detects the position of the positive electrode 24 based on the imaging by the camera 80 as a 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.

  FIG. 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 the position of the detected positive electrode, and FIG. 14 is a conceptual diagram showing how the position of the negative electrode is determined. .

  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 source 70 before the packed positive electrode 20 is sucked by the suction hand 114.

  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.

  For the positive electrode 24 specified as a rectangle, a rectangular square C is calculated from the intersection of the sides as indicated by a dotted line in FIG. Furthermore, the center point of the positive electrode 24 is calculated by averaging the calculated positions of the square C. In addition, the inclination of the positive electrode 24 in the planar direction is also calculated based on the specified side posture. The calculated position information and inclination of the center point O of the positive electrode 24 are stored in the storage unit 150.

  The control unit 160 reads the position information and inclination of the center point O of the positive electrode 24 from the storage unit 150, controls the XY stage 122 so that the center point O is a predetermined position and the positive electrode 24 is in a constant posture. The XY stage 122 adjusts the position of the positive electrode 24 by moving / rotating the packaged positive electrode 20 in the plane direction. That is, the XY stage 122 functions as a position adjusting unit. Here, the position of the positive electrode 24 is adjusted so that the suction hand 114 becomes a reference position for picking up the packaged positive electrode 20 in order to accurately stack the positive electrode 24 and the negative electrode 30 in the stacking stage 140.

  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 is detected. Therefore, not the separator 40 but the position of the packed positive electrode 20 can be adjusted based on the detected position of the positive electrode 24. The positive electrode 24 is always delivered to the suction hand 114 at a predetermined position. As a result, the stacking robot 110 can accurately stack the positive electrode 24 without shifting from the stacked body 15. That is, it can be accurately positioned indirectly with the negative electrode 30. The hand 114 and the XY stage 122 can work together to appropriately stack the packaged positive electrode 20 on the negative electrode 30 based on the detected position of the positive electrode 24 as a stacking unit.

  The electrode position detection device 200 detects not only the position of the positive electrode 24 but also the position of the negative electrode 30. Here, the electrode position detection apparatus 200 further includes a light source 72, a camera 82, and an XY stage 132.

  The electrode position detection device 200 projects light from the light source 72 to the negative electrode 30 placed on the negative electrode supply table 130. The light to be projected may be any light as long as it has a wavelength that does not pass through the negative electrode 30 (is reflected or absorbed). For example, white light is projected. The projected light is reflected by the negative electrode 30. The camera 82 receives the reflected light through the negative electrode 30 and images the negative electrode 30. The imaged negative electrode 30 is as shown in FIG. The control unit 160 analyzes the imaging result and detects each side of the negative electrode 30. Further, the control unit 160 calculates the position of the square c of the negative electrode 30 as the detected intersection of each side. The control unit 160 calculates the average of the calculated positions of the square c and calculates the center point o of the negative electrode 30. In addition, the inclination of the positive electrode 24 in the planar direction is also calculated based on the specified side posture. The calculated position information and inclination of the center point o of the negative electrode 30 are stored in the storage unit 150.

  The control unit 160 reads the center point o and inclination of the negative electrode 30 from the storage unit 150, and controls the XY stage 132 so that the center point o is located at a predetermined position and the negative electrode 30 is in a constant posture. The XY stage 132 adjusts the position of the negative electrode 30 by moving / rotating the negative electrode 30 in the planar direction. The XY stage 132 functions as a position adjusting unit. Thereby, not only the positive electrode 24 but also the negative electrode 30 is delivered to the suction hand 116 at the same position every time. Here, the position of the negative electrode 30 is adjusted so that the suction hand 116 becomes a reference position for picking up the negative electrode 30 in order to accurately stack the positive electrode 24 and the negative electrode 30 in the stacking stage 140.

  As described above, both the positive electrode 24 and the negative electrode 30 are taken from the suction hands 114 and 116 at the same position each time. Therefore, also in the lamination stage 140, the negative electrode 30 and the positive electrode 24 are laminated at the same position every time, and the accurate lamination of the power generating elements 15 can be achieved.

  Note that the accurate stacking of the positive electrode 24 and the negative electrode 30 is a stack in which it is determined that there is no stacking deviation.

  15 is a diagram showing the camera on the stacking stage, FIG. 16 is a diagram showing the structure of the camera, FIG. 17 is a conceptual diagram showing how to check the position of the positive electrode in the packed positive electrode, and FIG. FIG. 19 is a conceptual diagram showing a state of confirming the position of the negative electrode, FIG. 20 is a conceptual diagram showing a state of the negative electrode in which the position of the side is specified, and FIG. It is a conceptual diagram which shows a relative position. Note that FIG. 17A is a conceptual diagram of the laminated body when confirming the position of the positive electrode of the packaged electrode as seen from the front, and FIG. 17B is a conceptual diagram of the laminated body as seen from the plane. . FIG. 19A is a conceptual diagram of the laminate when the position of the negative electrode is confirmed as seen from the front, and FIG. 19B is a conceptual diagram of the laminate as seen from the plane.

  The electrode position detection apparatus 300 will be described with reference to FIGS. 5, 15, and 16.

  The electrode position detection apparatus 300 includes a light source 76, a camera 84, and a control unit 160. Although not shown in FIG. 6, the light source 76 and the camera 84 are installed above the stacking stage 140. The light source 76 and the camera 84 are each connected to the control unit 160, and the operation is controlled by the control unit 160.

  The light source 76 is disposed above the stacking stage 140 as light projecting means. The light source 76 transmits light having a wavelength that passes through the separator 40 toward the packaged positive electrode 20 or the negative electrode 30 placed on the uppermost layer of the laminate 15 and reflects to the positive electrode 24 and the negative electrode 30, for example, near infrared light. Light up. 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.

  In the present embodiment, the light source 76 is provided in a ring shape around the camera 84 as shown in FIG. The light source 76 projects light toward at least the four corners of the corresponding positive electrode 24 (packed positive electrode 20) or negative electrode 30.

  As shown in FIG. 15, the camera 84 is disposed above the stacking stage 140 as a light receiving unit, and images the power generation element 15 formed on the stacking stage 140 from directly above the stacking direction. In the present embodiment, four cameras 84 are provided and images the four corners of the positive electrode 24 (packed positive electrode 20) or the negative electrode 30, respectively.

  The control unit 160 detects the positions of the positive electrode 24 and the negative electrode 30 based on the image captured by the camera 84 as detection means.

  The operation (electrode detection method) of the electrode position detection device 300 when detecting the positions of the positive electrode 24 and the negative electrode 30 will be described.

  In the lamination stage 140, the packaged positive electrode 20 and the negative electrode 30 are alternately laminated by the sheet laminating apparatus 100. The electrode position detection device 300 projects light from the light source 76 onto the packaged positive electrode 20 or negative electrode 30 in the uppermost layer of the laminate 15.

  When the packaged positive electrode 20 is laminated on the uppermost layer as shown in FIG. 17A, the electrode position detection device 300 projects light onto the packaged positive electrode 20 by the light source 76. The projected light passes through the separator 40 of the packaged positive electrode 20 and is reflected by the positive electrode 24. The camera 84 receives reflected light through the positive electrode 24. For example, the four cameras 84 capture an area indicated by a dotted line in FIG. When the image in the region indicated by the dotted line is obtained, the control unit 160 analyzes the image and specifies a part of the side of the positive electrode 24 in the range indicated by the double arrow in the drawing. The control unit 160 extends a part of the specified side of the positive electrode 24 and specifies the position of the side of the positive electrode active material layer 22 that is a coating portion of the positive electrode 24. Thereby, the position of the specified side is expressed in a rectangle as shown in FIG. The specified position information of the side of the positive electrode active material layer 22 is stored in the storage unit 150 as information indicating the position of the positive electrode 24. The camera 84 can also identify the position of the separator 40 by photographing the packaged positive electrode 20 in the absence of light from the light source 76. The position information of the specified side of the separator 40 may also be stored in the storage unit 150. Thereby, the relative position of the positive electrode 24 with respect to the separator 40 can also be specified. A part of the projected light is transmitted through the separator 40 at the outer peripheral portion of the positive electrode 24, further transmitted through the separator 40, and reflected by the negative electrode 30. In this case, the camera 84 receives the reflected light, but receives light that is weaker than the reflected light reflected by the positive electrode 24. Therefore, an image obtained by imaging is thinner than that of the positive electrode 24. Therefore, the negative electrode 30 can be reliably compared with the positive electrode 24 in an image state.

  Subsequently, as illustrated in FIG. 19A, when the negative electrode is stacked on the stacked body 15, the electrode position detection device 300 projects light onto the negative electrode 30 by the light source 76. The projected light is reflected by the negative electrode 30. The camera 84 receives reflected light via the negative electrode 30. For example, the four cameras 84 capture an area indicated by a dotted line in FIG. When the image in the region indicated by the dotted line is obtained, the control unit 160 analyzes the image and specifies a part of the side of the negative electrode 30 in the range indicated by the double arrow in the drawing. The control unit 160 extends a part of the specified side of the negative electrode 30 and specifies the position of the side of the negative electrode active material 32 that is a coating portion of the negative electrode 30. Thereby, the position of the specified side is represented in a rectangle as shown in FIG. The specified position information of the side of the negative electrode active material layer 32 is stored in the storage unit 150 as information indicating the position of the negative electrode 30. The camera 84 can also identify the position of the separator 40 by photographing the end of the packaged positive electrode 20 laminated under the negative electrode 30 in the absence of light from the light source 76. Since the separator 40 is larger than the negative electrode 30, even if the negative electrode 30 is laminated on the separator 40, it can be photographed by the camera 84 only at the end. The position information of the sides of the separator 40 specified by photographing may also be stored in the storage unit 150. Thereby, the relative position of the negative electrode 30 with respect to the separator 40 can also be specified.

  As described above, the control unit 160 sequentially detects the positions of the positive electrode 24 and the negative electrode 30 (the relative position of the positive electrode 24 with respect to the separator 40 and the relative position of the negative electrode 30 with respect to the separator 40) and stores them in the storage unit 150. The controller 160 determines whether the negative electrode 30 and the positive electrode 24 have a stacking deviation after the stacked body 15 is completed as a battery element or during the stacking of the stacked body 15.

  When determining the stacking deviation, the control unit 160 reads the positional information of the sides of the positive electrode 24 and the negative electrode 30 from the storage unit 150 and detects the relative positional relationship between the two. At the time of detection, the positions of the positive electrode 24 and the negative electrode 30 specified in FIGS. 18 and 20 are overlapped. The superposed conceptual diagram is as shown in FIG. The control unit 160 analyzes the superimposed result and determines the relative positional relationship between the positive electrode 24 and the negative electrode 30. Specifically, the positions of the sides of the positive electrode 24 and the negative electrode 30 are confirmed, and it is confirmed whether the corresponding sides are within a predetermined range. For example, when the positive electrode 24 is smaller than the negative electrode 30 in a range overlapping with the separator 40, it is confirmed whether or not each side of the positive electrode 24 is inside each corresponding side of the negative electrode 30. Then, the control unit 160 determines that there is no stacking deviation when all sides of the positive electrode 24 are inside the negative electrode 30. Not only whether the side is the inner side or the outer side, but the distance between the sides may be calculated to determine the stacking deviation within the range of the distance.

  Further, 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 projected for positive electrode detection will be described.

  FIG. 22 is a schematic view showing the transmission characteristics of the separator. In FIG. 22, the horizontal axis indicates the wavelength (nm) of light, and the vertical axis indicates the light transmittance (%).

  FIG. 22 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. 22, 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. 22 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.

(Modification)
In the above embodiment, the form in which the positive electrode 24 is packed in the separator 40 as the packaged positive electrode 20 has been described. 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.

  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, is reflected by the positive electrode 24, and is imaged by the camera 80. That is, the camera 80 images the reflected light of the positive electrode 24 instead of the shadow of the positive electrode 24.

  In the above embodiment, the case where the positive electrode lead 11 and the negative electrode lead 12 are led out from the same end portion of the exterior member 13 as shown in FIG. 1 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 packaged positive electrode 20 and the negative electrode 30 are laminated so that the tab portions 26 and 34 are opposite to each other.

  In the above embodiment, the reference position of the positive electrode 24 for the suction hand 114 to pick up the packed positive electrode 20 is set in advance, and the position of the packed positive electrode 20 is set so that the positive electrode 24 is positioned at the reference position. Is corrected. However, it is not limited to this. For example, the position of the negative electrode 30 is detected by the electrode position detection device 200 and the position is adjusted. The position of the negative electrode 30 can be stored in the storage unit 150. A reference position for picking up the positive electrode 24 may be calculated based on the stored position of the negative electrode 30, and the position of the packaged positive electrode 20 may be adjusted so that the positive electrode 24 is positioned at the calculated reference position. Of course, when the reference position matches the position of the positive electrode 24, the position of the positive electrode 24 need not be adjusted. Further, when the deviation between the reference position and the position of the positive electrode 24 is within a predetermined error range, the position of the positive electrode 24 may not be adjusted.

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 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 (10)

Detecting means for detecting the position of the first electrode with respect to the packed electrode in which the first electrode is disposed in the bag-shaped separator;
Laminating means for laminating the first electrode on a second electrode having a polarity different from that of the first electrode based on the detected position of the first electrode;
An electrode laminating apparatus.   The electrode according to claim 1, wherein the stacking unit includes a position adjusting unit that adjusts the position of the packaged electrode based on the detected position of the first electrode and a reference position required for stacking with the second electrode. Laminating equipment.   3. The electrode stacking apparatus according to claim 2, wherein the position adjusting unit is a stage capable of moving and rotating the packaged electrode in a planar direction in a state where the packaged electrode is placed. The detection means includes
Light projecting means for projecting the first electrode with light that passes through the separator and does not pass through the first electrode;
Light receiving means for receiving the light transmitted through the separator,
The electrode stacking apparatus according to any one of claims 1 to 3, wherein a position of the electrode is detected based on a light reception result of the light receiving step.   The electrode stacking apparatus according to claim 4, wherein the light projected by the light projecting unit is light having a wavelength at which the transmittance of the separator is 50% or more.   The electrode stacking apparatus according to claim 4, wherein the separator is a ceramic separator, and the light is near infrared light.   The electrode stacking apparatus according to claim 1, wherein the detection unit detects a side of the first electrode and detects a position of the first electrode based on a position of the side. A detection step of detecting the position of the first electrode with respect to the packaged electrode in which the first electrode is disposed in the bag-shaped separator;
A stacking step of stacking the first electrode on a second electrode having a polarity different from that of the first electrode based on the detected position of the first electrode;
An electrode stacking method comprising:   The electrode according to claim 8, wherein the stacking step includes a position adjusting step of adjusting the position of the packaged electrode based on the detected position of the first electrode and a reference position required for stacking with the second electrode. Lamination method. The detection step includes
Projecting the first electrode with light that passes through the separator and does not pass through the first electrode;
Receiving the light transmitted through the separator;
Detecting a position of the electrode based on a light reception result of the light receiving step;
The electrode position detection method of Claim 8 or Claim 9 containing these.