JP6237362B2 - Sheet stacking device - Google Patents

Description

  The present invention relates to a sheet-like material laminating apparatus for laminating sheet-like materials on a lamination table.

  A vehicle such as an EV (Electric Vehicle) or a PHV (Plug in Hybrid Vehicle) is equipped with a secondary battery such as a lithium ion battery as a power storage device that stores power supplied to an electric motor serving as a prime mover. The secondary battery includes an electrode assembly in a case. The electrode assembly is formed by stacking, for example, rectangular and sheet-like positive and negative electrodes each having an active material layer on both sides with a separator interposed therebetween. It is a thing.

  At the time of manufacturing the secondary battery, for example, the positive electrode, the separator, and the negative electrode stored in each storage unit are transported from each storage unit to the stacking table by a transport device, and stacked on the stacking table to form an electrode assembly. Is manufactured. And the manufactured electrode assembly is accommodated in a case, and a secondary battery is manufactured.

  In the electrode assembly, from the viewpoint of suppressing a decrease in energy density in the secondary battery and from the viewpoint of insertability into the case of the electrode assembly, the entire surface of the positive electrode active material layer is interposed via the separator. In this case, the outer shape of the electrode assembly is contained inside a predetermined reference outer shape. In other words, it is not preferable that each electrode and the separator move in a direction along their surfaces and the outer shape of the electrode assembly protrudes from a predetermined reference outer shape. For this reason, after the predetermined number of predetermined number of electrodes are stacked and the electrode assembly is formed, the above-described inspection for the stacking deviation is performed.

  However, even if the misalignment can be detected, in order to correct the misalignment, it is necessary to restack all the electrodes and separators of each electrode, resulting in poor productivity. Further, if the electrode assembly is discarded as a defective product without correcting the stacking deviation, the material is wasted.

In view of this, an inspection apparatus that detects a stacking deviation every time an electrode and a separator are stacked has been proposed (see, for example, Patent Document 1).
As shown in FIG. 11, the inspection apparatus 90 of Patent Document 1 includes a visible light irradiation unit 81 provided on the side of a laminated body 80 to be inspected, and an infrared light irradiation provided at an upper position of the inspection target. Means 82, a visible light camera 83, and an infrared light camera 84 are provided. The inspection device 90 includes a control device 88 to which a visible light camera 83 and an infrared light camera 84 are connected in signal.

  Then, every time two electrodes and separators that are sheet-like materials are stacked on the stacking stage 87, visible light is irradiated from the side by the visible light irradiation means 81. Then, visible light hits the edge portion of the uppermost separator immediately after lamination, and the edge portion is imaged by the visible light camera 83.

  Further, when infrared light is irradiated from above the infrared light irradiation means 82 toward the laminate 80, the infrared light passes through the separator immediately after the lamination, and the electrode immediately below the infrared light camera 84. Is imaged. Then, based on the imaging of the visible light camera 83 and the infrared light camera 84, the control device 88 can detect the stacking state of the uppermost separator and the electrode immediately below it, and can detect stacking deviation. it can.

JP 2010-257861 A

  By the way, a sheet-like material such as an electrode or a separator is often manufactured while being wound around a take-up roll for the reason of the manufacturing method, and the sheet-like material is familiar with the shape of the take-up roll when in a wound state. It may be curved. For this reason, when a number of sheet-like materials are laminated on the curved sheet-like material, the sheet-like material laminated on the curved sheet-like material subsequently causes a stacking deviation, and the stack of the laminated body becomes the top. Lamination may occur at a position other than the upper part. However, in the laminating apparatus of Patent Document 1, only the stacking deviation between the uppermost sheet-like material and the sheet material immediately below it can be detected.

  An object of the present invention is to provide a sheet-like material laminating apparatus capable of detecting a laminating deviation regardless of the generation position.

  A sheet-like material laminating apparatus for solving the above problems is a laminating device for forming a sheet-like material laminate on a lamination table, and projects light from below the sheet-like material laminated on the lamination table. A light projecting unit, a detecting unit that detects projection of the laminate formed by light irradiation, and a stacking deviation in a direction along the surface of the sheet-like object based on the projection detected by the detecting unit And a determination unit for determining the presence or absence of the above.

  According to this, when light is projected from below the sheet-like material, a projection of the laminated body is formed, and the projection is detected by the detection unit. Then, when a stacking deviation of the sheet-like material occurs, the projection of the sheet-like material that has been misstacked enters a part of the projection of the stacked body. For this reason, it is possible to detect the misalignment based on the projection. Therefore, even if the already laminated sheet-like material causes a stacking shift and a stacking shift occurs at a position other than the uppermost part of the stacked body or directly below it, the stacking shift can be detected from the projection.

In the sheet-like material stacking apparatus, the sheet-like material is a positive electrode, a negative electrode, and a separator that constitute an electrode assembly of the power storage device.
According to this, in the stacking process of the electrode assembly in the power storage device, the stacking deviation can be detected by the stacking apparatus after the stacking timing of the electrodes or separators or the stacking misalignment of the stacked electrodes or separators occurs. . Therefore, the stacking can be stopped at the timing when the stacking deviation is detected, and the stacking can be performed again immediately after the timing when the stacking shift is detected. Therefore, for example, after completion of the electrode assembly, it takes less time than re-stacking all the electrodes and separators to correct the stacking error that occurred during the stacking, and in addition, correct the stacking error. Even when discarded as a defective product, waste of materials can be reduced.

In the sheet-like material stacking apparatus, it is preferable that the stacking table is of a light transmission type, and the light projecting unit is disposed below the stacking table.
According to this, since the light irradiated from the light projection part permeate | transmits a lamination | stacking table, the projection of the laminated body laminated | stacked on the lamination | stacking table can be made clearly.

In the sheet-like material stacking apparatus, the detection unit is preferably a camera.
According to this, projection can be detected clearly.
In addition, the sheet-like material stacking apparatus includes a transport device that transports the sheet-like material to the stacking table, and the determination unit detects the stacking deviation at a timing when the transport device retreats from a detection range of the detection unit. It is preferable to judge.

According to this, it is possible to quickly determine whether or not there is a stacking deviation after the transport device is retracted while avoiding the transport device from overlapping the projection.
In the sheet-like material stacking apparatus, it is preferable that the light projecting unit starts projecting light at a timing when the conveying device retreats from a detection range of the detection unit.

  According to this, it is possible to postpone the time when the lifetime of the light projecting unit is reached, compared to the case where the light projecting unit is always operated.

  According to the present invention, stacking deviation can be detected regardless of the generation position.

The perspective view which shows the secondary battery of embodiment. The disassembled perspective view which shows the component of an electrode assembly. The figure which shows a lamination apparatus typically. The top view which shows the laminated body on a lamination | stacking table. The schematic diagram which shows the state which laminated | stacked the electrode on the laminated body with the conveying apparatus. The schematic diagram which shows the state which the conveying apparatus evacuated from the detection range of the camera. (A) is a top view which shows the projection of the laminated body in which the lamination | stacking deviation does not arise, (b) is a side view of the laminated body in which the lamination | stacking deviation does not arise. (A) is a top view which shows the projection of the laminated body in which the lamination | stacking deviation | deviation produced | generated, (b) is a side view of the laminated body in which the lamination | stacking deviation | deviation produced. The schematic diagram which shows the other example of a lamination apparatus. The schematic diagram which shows the other example of a lamination apparatus. The figure which shows background art.

Hereinafter, an embodiment in which a sheet stacking apparatus is embodied as an electrode stacking apparatus will be described with reference to FIGS.
First, the secondary battery 10 as a power storage device will be described.

  As shown in FIG. 1, the secondary battery 10 includes an electrode assembly 14 and an electrolytic solution in a case 11. The case 11 includes a bottomed rectangular tube-shaped main body member 12 and a rectangular flat plate-shaped lid 13 that closes an opening for inserting the electrode assembly 14 into the main body member 12. The main body member 12 and the lid 13 are both made of metal (for example, made of stainless steel or aluminum). The secondary battery 10 is a prismatic battery and is a lithium ion battery.

  A positive electrode terminal 15 and a negative electrode terminal 16 are electrically connected to the electrode assembly 14. The positive electrode terminal 15 and the negative electrode terminal 16 are respectively attached with ring-shaped insulating members 13 b for insulating from the case 11. The positive terminal 15 and the negative terminal 16 are exposed from the lid 13 to the outside of the case 11.

  As shown in FIG. 2, the electrode assembly 14 includes a plurality of positive electrodes 21 as sheets and positive electrodes, a plurality of negative electrodes 26 as sheets and negative electrodes, and a sheet that insulates both. And a separator 20 as a shape. The positive electrode 21 includes a positive electrode active material layer 23 on both surfaces of a positive metal foil (aluminum foil) 22. The positive electrode 21 has a positive electrode uncoated portion 24 in which the positive electrode active material layer 23 is not provided and the positive metal foil 22 is exposed along one side. In the positive electrode 21, a positive electrode current collecting tab 24 a protrudes from a part of one side of the positive electrode uncoated portion 24.

  The negative electrode 26 includes a negative electrode active material layer 28 on both surfaces of a negative electrode metal foil (copper foil) 27. The negative electrode 26 has a negative electrode uncoated portion 29 in which the negative electrode active material layer 28 is not provided and the negative electrode metal foil 27 is exposed along one side. In the negative electrode 26, a negative electrode current collecting tab 29 a is provided on a part of one side of the negative electrode uncoated portion 29 so as to protrude. The electrode assembly 14 has a stacked structure in which a plurality of positive electrodes 21 and a plurality of negative electrodes 26 are alternately stacked, and a separator 20 is interposed between the positive electrodes 21 and the negative electrodes 26.

  In the positive electrode 21 and the negative electrode 26, the lengths of the two adjacent sides of the negative electrode active material layer 28 (the length in the longitudinal direction and the length in the short direction) are 2 adjacent to the positive electrode active material layer 23. It is set to be longer than the length of each side (length in the longitudinal direction and length in the short direction). That is, the negative electrode active material layer 28 is set to a size that can cover the entire surface of the positive electrode active material layer 23. In the electrode assembly 14, the entire surface of the positive electrode active material layer 23 is laminated so as to face the negative electrode active material layer 28 with the separator 20 interposed therebetween.

  As shown in FIG. 7A, the outer shape of the electrode assembly 14 in which the entire surface of the positive electrode active material layer 23 is laminated so as to face the negative electrode active material layer 28 via the separator 20 is predetermined. The shape follows the reference outline L. The reference outer shape L includes a slight manufacturing tolerance than the outer shape line of the electrode assembly 14 in which the entire surface of the positive electrode active material layer 23 is laminated with the separator 20 facing the negative electrode active material layer 28. Is set. That is, the reference outer shape L is obtained by bordering the outer shape line of the electrode assembly 14 formed without causing the stacking deviation with a slight margin.

The electrode assembly 14 is manufactured by laminating the positive electrode 21, the separator 20, and the negative electrode 26 with an electrode laminating apparatus.
Next, an electrode stacking apparatus will be described.

  As shown in FIG. 3, the electrode stacking apparatus 30 includes a box-shaped positive electrode storage portion 31 that stores and stacks a plurality of positive electrodes 21 with current collecting tabs 24 a aligned in the same direction. In addition, the electrode stacking device 30 includes a box-shaped negative electrode storage portion 32 that stores and stacks a plurality of negative electrodes 26 with the current collecting tabs 29a aligned in the same direction. Furthermore, the electrode stacking apparatus 30 includes a box-shaped separator storage portion 36 that stores and stacks a plurality of separators 20. The electrode stacking device 30 includes a stacking table 33 on which the positive electrode 21, the separator 20, and the negative electrode 26 are placed. The stacked table 33 is disposed between the positive electrode storage unit 31 and the negative electrode storage unit 32.

  As shown in FIG. 4, the stacked table 33 has a square shape in plan view, and is larger than the planar shape including the current collecting tabs 24 a and 29 a of the positive electrode 21 and the negative electrode 26 and the planar shape of the separator 20. The laminated table 33 can transmit light and is made of a transparent or translucent resin.

  In the stacking table 33, the positive electrode 21 and the negative electrode 26 are arranged such that the positive current collecting tabs 24a are arranged in a row in the stacking direction and the negative current collecting tabs 24a are not overlapped with the positive current collecting tabs 24a. The electric tabs 29a are stacked so as to be arranged in a row along the stacking direction. And in the lamination | stacking table 33, the positive electrode 21 and the negative electrode 26 are laminated | stacked alternately via the separator 20, and the laminated body 17 is formed.

  As shown in FIG. 3, the positive electrode storage part 31, the negative electrode storage part 32, the separator storage part 36, and the lamination | stacking table 33 are arrange | positioned in the state aligned on the same straight line. The electrode stacking device 30 includes a guide rail 34 and a transport device 40 that can move along the guide rail 34.

  As shown in FIG. 4, the guide rail 34 is disposed at a position away from the upper surface along the direction along the upper surface of the stacked table 33, and the guide rail 34 and the stacked table 33 do not overlap in the vertical direction. The transport device 40 includes a rectangular suction pad 42, and the suction pad 42 is attached to one end of a substantially L-shaped arm 43. The other end of the arm 43 is connected to the guide rail 34 via the transport device 40. The suction pad 42 is suspended from the guide rail 34. The suction pad 42 can be moved along the guide rail 34 above the positive electrode storage unit 31, the negative electrode storage unit 32, the separator storage unit 36, and the stacking table 33 by the transport device 40.

  As shown in FIG. 3, the arm 43 of the transport device 40 includes a lifting device 44 that lifts and lowers the suction pad 42 in the middle of the axial direction. The lifting device 44 is a pneumatic cylinder, and the other end of the arm 43 is connected to the piston of the lifting device 44. The piston is movably accommodated in the cylinder tube 45 of the lifting device 44, and the arm 43 protrudes and retracts with respect to the cylinder tube 45 as the piston moves. Then, by controlling the supply and discharge of air to and from the lifting device 44, the arm 43 is moved in and out of the cylinder tube 45, and the suction pad 42 is lifted and lowered. The electrode stacking device 30 includes a control device 60 that controls driving of the transport device 40, and the transport device 40 is signal-connected to the control device 60. The control device 60 can control the transport device 40.

  The electrode stacking apparatus 30 includes a projector 37 as a light projecting unit disposed below the stacked table 33, and irradiates light from below the stacked table 33 toward the entire lower surface of the stacked table 33. For this reason, the laminated body 17 laminated on the laminated table 33 is irradiated with light transmitted through the laminated table 33 from below. In addition, in FIG. 3 etc., arrangement | positioning of the projector 37 and the projector 37 and the lamination | stacking table 33 is simplified and shown. The size of the projector 37 or the distance from the stacking table 33 is determined so that the projected light can pass through the stacking table 33 almost vertically at the outer peripheral position of the stacked body 17.

  The electrode stacking apparatus 30 includes a camera 39 as a detection unit disposed above the stacking table 33. The camera 39 images a projection 50 that is a shadow of the stacked body 17 formed by light projection from the light projector 37. The camera 39 is signal-connected to the control device 60, and the projection 50 captured by the camera 39 is output to the control device 60.

  The camera 39 always images the laminated table 33. Further, the camera 39 is arranged at a position where the entire upper surface of the stacked table 33 including the projection 50 can be imaged. Therefore, the imaging range (detection range) of the camera 39 is the entire top surface of the stacked table 33. A monitor 61 is signal-connected to the control device 60, and the projection 50 captured by the camera 39 can be displayed on the monitor 61.

  As shown in FIG. 7A, the above-described reference outline L is displayed on the monitor 61 in advance, and the control device 60 causes the monitor 61 to display the projection 50 on the reference outline L. Further, the position of the reference outer shape L on the stacked table 33 is stored in advance in the control device 60, and the control device 60 determines that the outer shape of the projection 50 is the reference outer shape L based on the data relating to the projection 50 output from the camera 39. It is determined whether or not it protrudes. If the control device 60 determines that the outer shape of the projection 50 protrudes from the reference outer shape L, the control device 60 determines that a stacking error has occurred in the stacked body 17 and detects the stacking error.

  The control device 60 stops driving the transport device 40 at the timing when the stacking deviation is detected. On the other hand, if the control device 60 determines that the outer shape of the projection 50 does not protrude from the reference outer shape L, that is, unless the stacking deviation is detected, the driving of the transport device 40 is not stopped.

  Further, the control device 60 can control the start of light projection by the light projector 37 and the end of light projection. The control device 60 starts the light projection by the projector 37 when the transport device 40 retreats from the imaging range (detection range) of the camera 39, and projects the light by the projector 37 when the transport device 40 enters the imaging range of the camera 39. Stop the light.

Next, the effect | action of the electrode lamination apparatus 30 is described with a lamination process.
Now, under the control of the control device 60, the transport device 40 is driven, and the transport device 40 moves to the positive electrode storage unit 31, the negative electrode storage unit 32, or the separator storage unit 36. The elevating device 44 is driven by the control of the control device 60, and the suction pad 42 is lowered in the storage units 31, 32, 36. Then, the adsorption pad 42 is driven under the control of the control device 60, and the positive electrode 21, the separator 20, or the negative electrode 26 is adsorbed to the adsorption pad 42.

  Next, under the control of the control device 60, the elevating device 44 is raised on the storage units 31, 32, 36, and the positive electrode 21, the separator 20, or the negative electrode 26 adsorbed on the adsorption pad 42 is raised. Then, under the control of the control device 60, the transport device 40 moves along the guide rail 34 and transports the positive electrode 21, the separator 20, or the negative electrode 26 adsorbed by the suction pad 42 toward the stacking table 33.

  As shown in FIG. 5, when the transport device 40 moves onto the stacking table 33, the lifting device 44 is lowered by the control of the control device 60, and the positive electrode 21, the separator 20, or the negative electrode 26 adsorbed on the suction pad 42. Are stacked on the stacked body 17 on the stacking table 33. In FIG. 5, the positive electrode 21 adsorbed by the adsorption pad 42 is laminated on the laminate 17.

  The stacked body 17 is formed on the stacked table 33 by repeatedly transporting the positive electrode 21, the separator 20, or the negative electrode 26 to the stacked table 33 by the transport device 40 and lifting and lowering the suction pad 42 by the lifting device 44. Is done. The control device 60 stops the light projection by the light projector 37 when the transport device 40 has moved up onto the stacking table 33 and enters the imaging range of the camera 39.

  As shown in FIG. 6, after the positive electrode 21, the separator 20, or the negative electrode 26 is stacked on the stacked body 17, the control device 60 is connected to the projector 37 at the timing when the transport device 40 is retracted from the imaging range of the camera 39. Start flooding. Then, the projection 50 of the stacked body 17 is formed by the light transmitted through the stacked table 33. Therefore, each time the positive electrode 21, the separator 20, or the negative electrode 26 is stacked on the stacking table 33, the light is projected and the projection 50 is imaged.

  As shown in FIGS. 7A and 7B, when there is no stacking deviation in the stacked body 17, the outer shape of the projection 50 fits inside the reference outer shape L and does not protrude from the reference outer shape L. For this reason, the control device 60 does not detect the stacking deviation and continuously drives the transport device 40 without stopping the drive of the transport device 40.

  As shown in FIG. 8B, when the laminated negative electrode 26 is curved, the separator 20 laminated on the negative electrode 26 moves along the curved surface of the negative electrode 26, and the laminated Deviation occurs.

  As shown in FIG. 8A, the outer shape of the projection 50 captured by the camera 39 immediately after the occurrence of the stacking deviation protrudes from the reference outer shape L. For this reason, the control device 60 detects the stacking deviation and stops the driving of the transport device 40.

According to the above embodiment, the following effects can be obtained.
(1) Light is projected onto the laminate 17 from below the laminate table 33, and the projection 50 of the laminate 17 is imaged by the camera 39. Then, by comparing the captured outer shape of the projection 50 with the reference outer shape L, it is possible to determine whether or not there is a stacking deviation. Since the projection 50 of the stacked body 17 is a detection target, it is possible to detect a stacking shift that occurs not only at the top of the stacked body 17 or directly below it but also at a position other than the top.

  (2) The stacking by the electrode stacking apparatus 30 can be stopped at the timing when the stacking deviation is detected by the electrode stacking apparatus 30, and the electrode assembly 14 can be stacked again immediately after the timing at which the stacking shift is detected. Therefore, for example, after completion of the electrode assembly 14, less labor is required than when all the positive electrodes 21, the separators 20, and the negative electrodes 26 are stacked again in order to correct the stacking error that occurred during the stacking. In addition, waste of materials can be reduced even when discarded as a defective product without correcting misalignment.

  (3) The laminated table 33 is a light transmission type, and the projector 37 is disposed below the laminated table 33. For this reason, the projection 50 can be clearly made by projecting light capable of forming the projection 50 from the projector 37, and the presence or absence of the stacking deviation of the stacked body 17 can be accurately determined.

  (4) The formed projection 50 can be imaged by the camera 39. Therefore, it is possible to clearly detect the formed projection 50 and accurately determine whether or not the outer shape of the projection 50 protrudes from the reference outer shape L.

  (5) The control device 60 determines whether or not there is a stacking deviation at the timing when the transport device 40 retreats from the imaging range of the camera 39. For this reason, the control device 60 can determine whether or not there is a stacking deviation in a state where the shadow of the transport device 40 does not enter the formed projection 50.

Further, since the control device 60 determines whether or not there is a stacking error immediately after the transfer device 40 is retracted, even if a stacking error occurs, the stacking error can be detected quickly.
(6) The control device 60 starts the light projection by the light projector 37 at the timing when the transport device 40 is retracted from the imaging range of the camera 39. For this reason, for example, compared with the case where the projector 37 is always operated, the time when the projector 37 reaches the end of its life can be postponed.

  (7) The electrode stacking device 30 determines whether or not there is a stacking deviation every time the positive electrode 21, the separator 20, or the negative electrode 26 is stacked. If the stacking deviation is detected, the electrode stacking device 30 immediately stops the stacking. For this reason, it is possible to prevent the stacking process from being continued after the stacking shift occurs, and to quickly grasp the cause of the stacking shift.

In addition, you may change the said embodiment as follows.
As shown in FIG. 9, in the electrode stacking apparatus 30, the light projecting unit may be a light emitting layer 33 a provided on the surface of the stacking table 33 instead of the projector 37. As the light emitting layer 33a, for example, a layer formed from a coating film made of organic EL may be used. Even in this case, light can be projected from below the stacked body 17 by the light emission of the light emitting layer 33a.

  In the electrode stacking apparatus 30, the light projecting unit may be a light projector built in the stacked table 33 so as to be lower than the upper surface of the stacked table 33, instead of the projector 37 provided below the stacked table 33.

  As shown in FIG. 10, a mirror 52 may be provided above the laminated table 33 at a position where the four sides of the laminated body 17 are reflected, and a conical mirror 53 may be provided at a position surrounded by the mirror 52. Then, the projection 50 may be transferred to the conical mirror 53 by each mirror 52, and may be imaged by the camera 39 through the conical mirror 53.

In this case, the camera 39 can be disposed closer to the stacked body 17 and the electrode stacking apparatus 30 can be made compact compared to the case where the projection 50 is directly imaged by the camera 39.
Depending on the arrangement of the mirror 52 and the conical mirror 53, the detection unit (camera 39) may be arranged on the side of the laminated table 33 instead of above the laminated table 33.

○ The projector 37 may be always operated.
The detection unit may be a light receiving sensor instead of the camera 39.
In the embodiment, the reference outer shape L is set in advance and the presence or absence of stacking misalignment is determined by comparing the reference outer shape L with the outer shape of the projection 50 each time the stacking is performed. The outer shape of the sheet-like material (for example, the negative electrode 26) first placed on the stacking table 33 may be a reference outer shape, and a stacking deviation may be detected when the outer shape of the negative electrode 26 protrudes.

  The projection 50 is imaged by the camera 39 at the timing when the transport device 40 is retracted from the imaging range of the camera 39, but the present invention is not limited to this. For example, the camera 39 always captures an image, and the control device 60 may acquire imaging data obtained at the timing when the transport device 40 is retracted to determine whether there is a stacking deviation.

  In the embodiment, the stacking table 33, the positive electrode storage unit 31, the negative electrode storage unit 32, and the separator storage unit 36 are arranged on the same straight line, and the electrode stacking device 30 is movable along the guide rail 34. However, it is not limited to this. For example, the stacking table 33 and the storage units 31, 32, and 36 may be arranged in a turntable shape, and the transfer device 40 may be rotated to be movable.

  The electrode laminating apparatus 30 may laminate a sheet-like material other than the positive electrode 21, the separator 20, or the negative electrode 26. As the sheet-like material, for example, a material in which a base material sheet is coated with a predetermined shape is used. It may be manufactured by cutting into pieces.

The power storage device is not limited to the secondary battery 10 and may be embodied as a power storage device such as an electric double layer capacitor.
The number of the positive electrode 21, the separator 20, and the negative electrode 26 constituting the electrode assembly 14 may be changed as appropriate.

  In the embodiment, the positive electrode 21 has the positive electrode active material layer 23 on both sides of the positive electrode metal foil 22, but may have the positive electrode active material layer 23 only on one side of the positive electrode metal foil 22. Similarly, the negative electrode 26 has the negative electrode active material layer 28 on both sides of the negative electrode metal foil 27, but may have the negative electrode active material layer 28 only on one side of the negative electrode metal foil 27.

  The positive electrode 21 may be stored in the bag-shaped separator 20 in advance. In this case, in the electrode stacking apparatus 30, the positive electrode storage unit 31 stores the positive electrode 21 stored in the separator 20 and stores the separator. The part 36 is deleted.

  The secondary battery 10 is a lithium ion battery, but is not limited thereto, and may be another secondary battery such as nickel metal hydride. In short, any ion may be used as long as ions move between the positive electrode active material layer 23 and the negative electrode active material layer 28 and transfer charge.

  DESCRIPTION OF SYMBOLS 14 ... Electrode assembly, 17 ... Laminate, 20 ... Separator as sheet-like material, 21 ... Positive electrode as sheet-like material and positive electrode, 26 ... Negative electrode as sheet-like material and negative electrode, 30 ... Electrode laminating device as a laminating device, 33... Laminating table, 37... Projector as light projecting unit, 39... Camera as detecting unit, 40.

Claims (5)

A laminating apparatus for forming a laminate of a positive electrode, a negative electrode, and a separator as a sheet-like material on a laminating table,
A light projecting unit that projects light from below the sheet-like material laminated on the lamination table;
A detection unit for detecting a shadow of the laminate formed by the light projection of the light projecting unit;
And a determination unit that determines whether or not there is a stacking deviation in a direction along the surface of the sheet based on the shadow detected by the detection unit. The sheet stacking apparatus according to claim 1, wherein the stacking table is a light transmission type, and the light projecting unit is disposed below the stacking table. The sheet-like material stacking apparatus according to claim 1, wherein the detection unit is a camera. A conveying device for conveying the sheet to said stacking table, the determination unit, the detection unit from the detection range the conveying device is determined claims 1 to 3 wherein the stack deviation in timing of saving A sheet-like material laminating apparatus according to any one of the above. The sheet projecting device according to claim 4 , wherein the light projecting unit starts projecting light at a timing when the transport device is retracted from a detection range of the detection unit.