JP6476782B2 - Electrode manufacturing method and electrode manufacturing apparatus - Google Patents

Description

  The present invention relates to an electrode manufacturing method and an electrode manufacturing apparatus, and more particularly to an electrode manufacturing method and an electrode manufacturing apparatus having an active material layer on at least one surface of a metal foil.

  In recent years, lithium ion secondary batteries have been adopted not only as power sources for electronic devices but also as power sources for hybrid vehicles and electric vehicles. Usually, a battery case of a lithium ion secondary battery contains an electrode assembly as a power generation element. The electrode assembly includes a positive electrode obtained by applying a positive electrode active material to a metal foil, and a negative electrode active material on the metal foil. It has a coated negative electrode and a separator interposed between the positive electrode and the negative electrode. As an electrode assembly, for example, there are a wound electrode assembly and a stacked electrode assembly. The wound electrode body is formed by winding an electrode sheet with a separator interposed between a long positive electrode and a negative electrode. On the other hand, a stacked electrode assembly has a structure in which a large number of positive electrodes, negative electrodes, and separators are alternately stacked.

  By the way, when manufacturing the electrodes (positive electrode and negative electrode) of the electrode assembly, a sheet-like electrode sheet may be wound into a roll. The electrode sheet wound in a roll shape has a problem that warping due to curling (hereinafter referred to as “winding warpage”) occurs. When the electrode sheet wound in a roll shape is warped, when the electrode assembly formed by stacking the electrodes obtained from the electrode sheet is accommodated in the case, the electrode may come into contact with the case. It is desired to suppress the winding of the electrode as much as possible. Further, if the electrode is warped, it is not preferable because the position of the positive electrode and the negative electrode may be shifted in the electrode assembly and the capacity may be reduced. For this reason, cancellation of the winding curvature of the electrode sheet wound by roll shape is requested | required.

  As a conventional technique aiming at elimination of the winding of the electrode, for example, a method for manufacturing an electrode disclosed in Patent Document 1 can be cited. In the method for producing an electrode disclosed in Patent Document 1, a primary firing step of heating a coating part in a state where the metal foil is wound in a roll shape, and a metal foil with respect to a wound state in the primary firing step. A rewinding step for reversing the front and back to roll up, and a secondary firing step for heating the coated portion in a state where the metal foil is reversed. According to the electrode manufacturing method disclosed in Patent Document 1, the curvature generated in the coating part in the primary firing step and the curvature generated in the coating part in the secondary firing step cancel each other, and the electrode obtained Warpage can be suppressed.

JP 2014-78436 A

  However, in the electrode manufacturing method disclosed in Patent Document 1, it is unavoidable that the electrode sheet is curved due to the heating in the secondary firing step, and the electrode sheet is still wound in a roll shape after firing. There is a problem that remains. Moreover, when the roll-shaped electrode sheet after baking is stored for a long period of time, for example, the winding warp generated in the electrode sheet is further increased.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an electrode manufacturing method and an electrode manufacturing apparatus capable of suppressing the electrode warping.

In order to solve the above-mentioned problems, the present invention includes an active material layer on at least one surface of a metal foil, a pulling-out step of pulling out a wound electrode sheet wound in a roll shape, and the drawn electrode sheet In the electrode manufacturing method, the electrode sheet drawn out from the wound state is warped in a direction opposite to the direction of warping of the electrode sheet. is brought into contact with a plurality of straightening rollers for straightening the warp in the order, when a reverse camber contact angle is defined by the contact area between the electrode sheet and the straightening rollers, the sum of the inverse warp contact angle exceeds the 360 °, the roll The correction roller is moved in a direction to increase the reverse warp contact angle of the correction roller in accordance with a decrease in the winding diameter of the electrode sheet in the wound state. And, the winding diameter Ru is detected by the winding diameter detecting means.

In the present invention, the wound electrode sheet wound in a roll shape is brought out of contact with and pulled out in the direction opposite to the direction of winding warp by a plurality of correction rollers. The reverse warp contact angle is defined by the contact range between the straightening roller and the electrode sheet. The sum of the reverse warp contact angles exceeds 360 ° , and the straightening roller is wound into a roll-shaped electrode sheet wound in a roll shape. As the take-up diameter decreases, the correction roller moves in the direction of increasing the reverse warp contact angle, and the take-up diameter is detected by the take-up diameter detecting means. Winding diameter of the electrode sheet from Rukoto be decreased with drawer electrode sheet, it is possible to correct the winding warping of the electrode sheet. Therefore, the electrode warpage obtained in the molding step can be suppressed. In addition, the electrode sheet tends to be more warped as it is closer to the winding center, but the correction roller moves as the winding diameter decreases to increase the reverse warping contact angle, so that strong winding warp is also corrected. Can do.

In the electrode manufacturing method, in the drawing step, the electrode sheet is brought into contact with a feeding roller that is bent in the same direction as the direction of winding warpage, and the reverse warping contact is made depending on a contact range of the electrode sheet in the sending roller. When a forward warpage contact angle smaller than the angle is defined, the difference between the reverse warpage contact angle and the forward warpage contact angle may be more than 360 ° .
In this case, even if the drawn electrode sheet is brought into contact with the feeding roller that warps in the same direction as the direction of winding and warping, the sum of the reverse warping contact angles is larger than the forward warping contact angle. Since the difference of 360 ° exceeds 360 ° , it is possible to correct the warping of the electrode sheet.

In addition, the present invention includes an active material layer on at least one surface of the metal foil, a drawing step of drawing out the wound electrode sheet wound in a roll shape, and forming the drawn electrode sheet into an electrode shape In the method for manufacturing an electrode having a forming step, in the drawing step, the electrode sheet drawn out from a wound state is bent in a direction opposite to a direction of winding of the electrode sheet to correct the winding warp. When the reverse warp contact angle is defined by the contact range between the straightening roller and the electrode sheet, the total of the reverse warp contact angles exceeds 360 °, and the electrode is drawn from the winding state. The sheet drawing path is a path that circulates around the electrode roll supporting the wound electrode sheet wound in a roll shape for one or more rounds. To.

Furthermore, in the present invention, an active material layer is provided on at least one surface of the metal foil, a drawing mechanism for pulling out the wound electrode sheet wound in a roll shape, and an electrode by cutting or punching from the drawn electrode sheet In the electrode manufacturing apparatus having a forming mechanism for forming, the pull-out mechanism includes an electrode roll that supports the wound electrode sheet wound in a roll shape, and the electrode sheet is in a direction opposite to a direction in which the electrode sheet is wound. A plurality of straightening rollers arranged continuously so as to be warped in order, a winding detection means for detecting a winding diameter of the wound electrode sheet wound in the form of a roll , and the straightening roller includes a roller moving means for moving the, the, when a reverse camber contact angle is defined by the contact area between the straightening roller and the electrode sheet, the sum of the inverse warp contact angle Beyond 60 °, the roller moving means, according to the decrease of the winding diameter, and wherein the Rukoto moving the straightening roller in the direction of increasing the reverse camber contact angle in the straightening roller.

According to the present invention, since the electrode sheet drawn out from the wound state is warped in the direction opposite to the direction of the electrode sheet by the correction roller, it is possible to correct the electrode sheet. The sum of the reverse warp contact angles exceeds 360 ° , and the correction roller moves in a direction to increase the reverse warp contact angle of the correction roller in accordance with a decrease in the winding diameter of the wound electrode sheet wound in a roll shape. The winding diameter is detected by the winding diameter detecting means. Winding diameter of the electrode sheet can be corrected reduced to Turkey Toka et With the withdrawal of the electrode sheet, the winding warping of the electrode sheet. In addition, the electrode sheet tends to be more warped as it is closer to the winding center, but the correction roller moves as the winding diameter decreases to increase the reverse warping contact angle, so that strong winding warp is also corrected. Can do.
The present invention also includes an active material layer on at least one surface of the metal foil, a pulling mechanism for pulling out the wound electrode sheet wound in a roll shape, and an electrode by cutting or punching from the drawn electrode sheet. In the electrode manufacturing apparatus having a forming mechanism for forming, the pull-out mechanism includes an electrode roll that supports the wound electrode sheet wound in a roll shape, and the electrode sheet is in a direction opposite to a direction in which the electrode sheet is wound. A plurality of straightening rollers arranged in succession so as to contact each other in a warped manner, and when the reverse warping contact angle is defined by the contact range between the straightening roller and the electrode sheet, the reverse warping contact angle The total of the plurality of correction rollers is five or more, and the rotation axes of the plurality of correction rollers surround the rotation axis of the electrode roll. Characterized in that it is location.

  The present invention can provide an electrode manufacturing method and an electrode manufacturing apparatus capable of suppressing electrode warping.

4 is an exploded perspective view of a secondary battery according to Reference Example 1. FIG. 5 is a longitudinal sectional view of a secondary battery according to Reference Example 1. FIG. It is a disassembled perspective view of a part of electrode assembly. It is a schematic side view which shows the extraction mechanism in the manufacturing apparatus of the electrode which concerns on the reference example 1. FIG. It is a schematic side view which shows the shaping | molding mechanism in the manufacturing apparatus of the electrode which concerns on the reference example 1 . It is a schematic side view which shows the extraction | drawer mechanism in the manufacturing apparatus of the electrode which concerns on 1st Embodiment. It is a schematic side view which shows the extraction mechanism in the manufacturing apparatus of the electrode which concerns on 2nd Embodiment.

( Reference Example 1 )
Hereinafter, an electrode manufacturing apparatus and an electrode manufacturing method using the electrode manufacturing apparatus according to Reference Example 1 of the present invention will be described with reference to the drawings. In this reference example , first, a secondary battery as a power storage device including an electrode manufactured by an electrode manufacturing apparatus will be described. The secondary battery of this reference example is specifically a lithium ion secondary battery.

As shown in FIGS. 1 and 2, the secondary battery 10 of the present reference example is a square secondary battery. An electrode assembly 12 is accommodated in the battery case 11 of the secondary battery 10. The longitudinal direction of the battery case 11 shown in FIG. 1 is shown as the left-right direction, the height direction of the battery case 11 is shown as the up-down direction, and the short direction of the battery case 11 is shown as the front-rear direction. The height direction of the battery case 11 coincides with the accommodation direction of the electrode assembly 12. The electrode assembly 12 is a power generation element that generates a battery function (charging / discharging, etc.).

  As shown in FIGS. 1 and 2, the battery case 11 includes a bottomed cylindrical case main body 13 and a rectangular flat plate-like cover body 15 that closes an opening 14 of the case main body 13. The case main body 13 and the lid 15 are made of a metal material (for example, aluminum). The lid 15 is fixed to the case body 13 by laser welding. As shown in FIG. 2, an insulating sheet 16 is attached to the inner surface of the case body 13 as an insulating member for insulation from the electrode assembly 12 accommodated in the battery case 11. In addition, an insulating sheet 17 as an insulating member for insulating the electrode assembly 12 housed in the battery case 11 is attached to the inner surface of the lid 15. A pair of through holes 18 are formed in the lid 15.

As shown in FIG. 3, the electrode assembly 12 includes a sheet-like positive electrode 21 and a sheet-like negative electrode 22. The positive electrode 21 and the negative electrode 22 correspond to electrodes. The positive electrode 21 includes a rectangular positive electrode main body 23 and a strip-shaped positive electrode current collector 24 formed at the edge of the positive electrode main body 23. The positive electrode body 23 includes a positive electrode metal foil 25 and a positive electrode active material layer 26 formed of a positive electrode active material coated on both surfaces of the positive electrode metal foil 25. The positive electrode current collector 24 is formed of a positive electrode metal foil 25, and the positive electrode current collector 24 is not coated with a positive electrode active material. In addition, the positive electrode metal foil 25 of this reference example is an aluminum foil.

The negative electrode 22 has a rectangular negative electrode main body 27 and a strip-shaped negative electrode current collector 28 formed at the edge of the negative electrode main body 27. The negative electrode main body 27 has a negative electrode metal foil 29 and a negative electrode active material layer 30 formed of a negative electrode active material coated on both surfaces of the negative electrode metal foil 29. The negative electrode current collector 28 is formed of a negative electrode metal foil 29, and the negative electrode current collector 28 is not coated with a negative electrode active material. In addition, the negative electrode metal foil 29 of this reference example is a copper foil. The left and right and top and bottom dimensions of the negative electrode body 27 are set slightly larger than the positive electrode body 23.

The electrode assembly 12 has a separator 31 that insulates between the positive electrode 21 and the negative electrode 22, and has a layered structure in which the plurality of positive electrodes 21 and the plurality of negative electrodes 22 are alternately stacked while maintaining an insulating state. That is, the electrode assembly 12 of this reference example is a stacked electrode assembly in which a plurality of positive electrodes 21 and a plurality of negative electrodes 22 are alternately stacked while maintaining an insulating state. The separator 31 is set to have substantially the same dimensions as the negative electrode body 27. For example, as shown in FIG. 3, the electrode assembly 12 is configured by laminating a plurality of positive electrodes 21 and a plurality of negative electrodes 22.

The positive electrode current collectors 24 are arranged in a row along the stacking direction of the electrode assemblies 12. Each of the negative electrode current collectors 28 is arranged in a row along the stacking direction like the positive electrode current collector 24 so as not to overlap with the positive electrode current collector 24. In the present reference example , the positive electrode current collectors 24 are set to the same size, and the negative electrode current collectors 28 are also set to the same size. Each positive electrode current collector 24 is collected on the front side of the electrode assembly 12 to form a positive electrode current collection group 32. Each negative electrode current collector 28 is collected on the front side of the electrode assembly 12 in the same manner as the positive electrode current collector 24 to form a negative electrode current collection group 33.

  A positive current collector plate 34 is joined to the positive current collector group 32, and a negative current collector plate 35 is joined to the negative current collector group 33. As shown in FIG. 2, the positive electrode current collector plate 34 is provided with a positive electrode terminal 37 that is electrically connected via an overcurrent protection circuit 36. Further, the negative electrode current collector plate 35 is provided with a negative electrode terminal 38 that is electrically connected via an overcurrent protection circuit 36. The positive terminal 37 is inserted into one through hole 18 of the lid 15, and the negative terminal 38 is inserted into the other through hole 18. An insulating ring 39 is attached to the positive electrode terminal 37 and the negative electrode terminal 38, and the lid 15 is insulated from the positive electrode terminal 37 and the negative electrode terminal 38 by the insulating ring 39.

Next, an electrode manufacturing apparatus according to Reference Example 1 will be described. The electrode manufacturing apparatus includes a drawing mechanism 40 shown in FIG. 4 and a forming mechanism 41 shown in FIG. For convenience of explanation, the left in FIGS. 4 and 5 is the front and the right is the rear. The lead-out mechanism 40 is a mechanism for providing an active material layer on at least one surface of the metal foil and pulling out the wound electrode sheet S wound in a roll shape. The forming mechanism 41 is a mechanism for forming the electrode sheet S drawn from the drawing mechanism 40 into the shape of an electrode (positive electrode 21 or negative electrode 22). In this reference example , the manufacturing apparatus for the positive electrode 21 will be described as an example, and the manufacturing apparatus for the negative electrode 22 is the same as the manufacturing apparatus for the positive electrode 21. .

  The drawing mechanism 40 shown in FIG. 4 includes an electrode roll 42 that supports the positive electrode sheet S in a wound state wound in a roll shape, and a plurality of rollers 43 to 48 that are arranged in the drawing path of the electrode sheet S. It has. The electrode roll 42 is held so that its rotational axis is horizontal, and can be rotated by receiving a rotational force from a drive source (not shown). The electrode sheet S wound around the electrode roll 42 in a roll shape is fired while being wound around the electrode roll 42, and the electrode sheet S is warped.

The plurality of rollers 43 to 48 are sequentially arranged from the upstream side to the downstream side of the drawing path of the electrode sheet S. In this reference example , the most upstream roller is the first roller 43, the second roller 44, the third roller 45, the fourth roller 46, and the fifth roller 47 in this order, and the most downstream side in the drawing path of the electrode sheet S This roller is a sixth roller 48. The rotation axis of the first roller 43 to the sixth roller 48 is parallel to the rotation axis of the electrode roll 42. The first roller 43 to the sixth roller 48 are rollable and are disposed so as to surround the electrode roll 42. In this reference example , a driving roller (not shown) for pulling out the electrode sheet S is provided on the downstream side of the first roller 43 to the sixth roller 48.

In the present reference example , the position where the electrode sheet S starts to be pulled out of the electrode roll 42 is below the electrode roll 42, and the first roller 43 is located at a position where the electrode sheet S is directed obliquely upward and forward from the position where the electrode roll S is started. Has been placed. A second roller 44 is disposed below the first roller 43, and a third roller 45 is disposed behind the second roller 44. A fourth roller 46 is disposed above the third roller 45, and a fifth roller 47 is disposed in front of the fourth roller 46 and substantially above the first roller 43. A sixth roller 48 is disposed obliquely below and in front of the fifth roller 47. Accordingly, the lead-out path of the electrode sheet S is a path that goes around the electrode roll 42 almost once.

In this reference example , the electrode roll 42 and the drive roller are rotated so that the electrode sheet S is pulled out so as to contact the first roller 43 to the fifth roller 47 sequentially in the direction opposite to the direction of curling. Therefore, among the plurality of first rollers 43 to sixth rollers 48 arranged in succession, the first roller 43 to the fifth roller 47 warp in the direction opposite to the direction of the electrode sheet S to be wound. Corresponds to a straightening roller to correct. On the other hand, the electrode sheet S is pulled out so as to come into contact with the sixth roller 48 which is the most downstream side in the drawing path of the electrode sheet S while warping in the same direction as the direction of curling. Accordingly, the sixth roller 48 corresponds to a feed roller that warps the electrode sheet S in the same direction as the direction of curling.

The first roller 43 to the fifth roller 47 are in contact with the electrode sheet S while being warped in the direction opposite to the direction of warping of the electrode sheet S. In the 1st roller 43-the 5th roller 47, the contact range with the electrode sheet S exists. The contact range is a range in the circumferential direction in which the electrode sheet S is in contact with the outer peripheral surfaces of the first roller 43 to the fifth roller 47. Depending on the contact range of the first roller 43 to the fifth roller 47, reverse warp contact angles θ1 to θ5 corresponding to the first roller 43 to the fifth roller 47 are defined. In this reference example , the reverse warp contact angle θ1 of the first roller 43 is 150 °, the reverse warp contact angle θ2 of the second roller 44, the reverse warp contact angle θ3 of the third roller 45, and the reverse warp of the fourth roller 46. The contact angle θ4 is 90 °. The reverse warp contact angle θ5 of the fifth roller 47 is 80 °. Therefore, the total sum of the reverse warp contact angles is 500 °.

The sixth roller 48 is in contact with the electrode sheet S while being warped in the same direction as that of the electrode sheet S. The sixth roller 48 has a contact range with the electrode sheet S. The contact range is a range in the circumferential direction in which the electrode sheet S contacts on the roller outer peripheral surface of the sixth roller 48. The forward warping contact angle θ6 corresponding to the sixth roller 48 is defined by the contact range of the sixth roller 48. In this reference example , the forward warpage contact angle θ6 of the sixth roller 48 is 80 °, and the total forward warpage contact angle is 80 °. Here, when the sum of the reverse warp contact angles of 500 ° and the sum of the forward warp contact angles of 80 ° are subtracted, the reverse warp contact angle becomes 420 °.

In this reference example , a set angle of 360 ° is set in advance for the sum of the reverse warp contact angles and the difference between the reverse warp contact angle and the forward warp contact angle. In the case of the electrode sheet S of this reference example, the inventors know in advance that the winding warp of the electrode sheet S is eliminated when the difference between the reverse warp contact angle and the forward warp contact angle exceeds 360 °. ing. In this reference example , the sum of the reverse warp contact angles of 500 ° exceeds a preset set angle of 360 °. The difference between the reverse warp contact angle 500 ° and the forward warp contact angle 80 ° is 420 °, which exceeds the set angle 360 °. The sum of the reverse warp contact angles is larger than the set angle, the sum of the reverse warp contact angles is larger than the forward warp contact angle, and the difference between the reverse warp contact angle and the forward warp contact angle is set larger than the set angle. . Accordingly, when the electrode sheet S is pulled out from the first roller 43 through the sixth roller 48, the winding of the electrode sheet S is corrected.

  Next, the forming mechanism 41 will be described. The forming mechanism 41 shown in FIG. 5 includes an electrode sheet conveying device (not shown) that conveys the electrode sheet S drawn by the drawing mechanism 40, and a punching device 49 that punches the drawn electrode sheet S to obtain the positive electrode 21. And an electrode transport device (not shown) for transporting the obtained electrode. The punching device 49 includes a fixed lower mold 50 and an upper mold 51 that moves up and down.

Next, a method for manufacturing the positive electrode 21 will be described. The manufacturing method of the positive electrode 21 of the present reference example includes a drawing step of drawing the wound electrode sheet S wound in a roll shape by the drawing mechanism 40, and forming the drawn electrode sheet S into the shape of the positive electrode 21 by the forming mechanism 41. A molding step of molding.

In the drawing process, the electrode sheet S passes through the first roller 43 by the rotation of the electrode roll 42 and the driving roller. When the electrode sheet S passes through the first roller 43, the electrode sheet S warps in the direction opposite to the winding warpage and comes into contact with the outer peripheral surface of the first roller 43. The electrode sheet S warps in the opposite direction to the winding warp corresponding to the reverse warping contact angle of 150 ° of the first roller 43, and the winding warp is corrected.

  Next, the electrode sheet S passes through the second roller 44, and at this time, the electrode sheet S warps in the direction opposite to the winding warpage and comes into contact with the outer peripheral surface of the second roller 44. The electrode sheet S warps in the opposite direction to the winding warp corresponding to the reverse warping contact angle of 90 ° of the first roller 43, and the winding warp is corrected. Next, the electrode sheet S passes through the third roller 45, warps in the direction opposite to the winding warpage, and comes into contact with the outer peripheral surface of the third roller 45. Similarly to the second roller 44, the electrode sheet S warps in the opposite direction to the winding warp corresponding to the reverse warping contact angle of 90 °, and the winding warp is corrected. Next, the electrode sheet S passes through the fourth roller 46 and warps in the direction opposite to the winding warpage and comes into contact with the outer peripheral surface of the fourth roller 46. Similarly to the second roller 44 and the third roller 45, the electrode sheet S warps in the opposite direction to the winding warp corresponding to the reverse warping contact angle of 90 °, and the warping is corrected.

Next, the electrode sheet S passes through the fifth roller 47 and comes into contact with the outer peripheral surface of the fifth roller 47 while being warped in the opposite direction to the warping. The electrode sheet S warps in the opposite direction to the winding warp corresponding to the reverse warping contact angle of 80 ° of the fifth roller 47, and the winding warp is corrected.

Next, the electrode sheet S passes through the sixth roller 48. At this time, the electrode sheet S warps in the same direction as the winding warpage and comes into contact with the roller outer peripheral surface of the fifth roller 47. The electrode sheet S warps in the same direction as the winding warp corresponding to the forward warping contact angle of 80 ° of the fifth roller 47, and the winding warpage of the electrode sheet S is promoted. However, in this reference example , the sum of the reverse warp contact angles is 500 ° and the sum of the forward warp contact angles is 80 °. Therefore, the sum of the reverse warp contact angles is 500 ° and the sum of the forward warp contact angles is 80 °. When subtracted, the reverse warp contact angle is 420 °. For this reason, the electrode sheet S pulled out from the sixth roller 48 is subjected to correction of the curling by reversely warping in the reverse direction to the winding direction corresponding to a reverse warping contact angle of 420 °. As a result, the electrode sheet S drawn out from the sixth roller 48 is in a state in which the winding warpage is almost eliminated.

  Next, the electrode sheet S in which the winding warp is corrected in the drawing process proceeds to the forming process. In the forming step, the electrode sheet S is continuously punched out by the punching device 49 of the forming mechanism 41 to form the positive electrode 21. The positive electrode 21 punched out by the punching device 49 is transported to the next process such as an assembly process for assembling the electrode assembly.

The electrode manufacturing method and electrode manufacturing apparatus of the present reference example have the following effects.
(1) The wound electrode sheet S wound in a roll shape is brought out of contact with the first roller 43 to the fifth roller 47 in a direction opposite to the direction of winding warpage and pulled out. The reverse warp contact angles θ1 to θ5 of the first roller 43 to the fifth roller 47 are defined by the contact range between the first roller 43 to the fifth roller 47 and the electrode sheet S, but the sum of the reverse warp contact angles. Exceeds the preset angle. From this, the winding warp of the electrode sheet S can be corrected. Accordingly, it is possible to suppress winding warpage of the electrodes (positive electrode 21 and negative electrode 22) obtained in the molding step.

(2) Even when the drawn electrode sheet S is brought into contact with the sixth roller 48 that warps in the same direction as the direction of winding warpage, the total sum of the reverse warp contact angles is 500 °, which is larger than the forward warp contact angle of 80 °. . The difference between the reverse warp contact angle and the forward warp contact angle is 420 °, which exceeds the set angle of 360 °. For this reason, the winding curvature of the electrode sheet S can be corrected.

(3) Since the drawing path of the drawn electrode sheet S is formed so as to go around the electrode roll 42, the space in the vertical direction can be effectively used as the space necessary for drawing. For this reason, the increase in the horizontal space required for drawing out the electrode sheet S can be suppressed.

(First Embodiment)
An electrode manufacturing apparatus and an electrode manufacturing method using the electrode manufacturing apparatus according to the first embodiment will be described. In the present embodiment, the first roller as the correction roller is moved in a direction to increase the reverse warp contact angle in the correction roller in accordance with a decrease in the winding diameter of the wound electrode sheet wound in a roll shape. It is configured. Reference Example 1 are given to the same configuration as the aid of the description of Example 1, used in common codes.

  As shown in FIG. 6, the first roller 43 in the drawer mechanism 40 is provided so that it can reciprocate within a certain range by a roller moving means (not shown). As for the certain range, specifically, there is a certain distance between the first position set between the electrode roll 42 and the sixth roller 48 and the second position obliquely above and behind the first position. The range. For convenience of explanation, the left in FIG. 6 is the front and the right is the rear.

  In FIG. 6, the first roller 43 located at the first position is indicated by a virtual line, and the first roller 43 located at the second position is indicated by a solid line. When the winding diameter of the electrode sheet S wound around the electrode roll 42 is equal to or larger than a preset first set diameter, the first position is set so that the first roller 43 is positioned. When the winding diameter of the electrode sheet S wound around the electrode roll 42 is equal to or smaller than a preset second set diameter, the first roller 43 is set to be positioned. When the winding diameter of the electrode sheet S wound around the electrode roll 42 is less than the first set diameter and exceeds the second set diameter, it is between the first position and the second position according to the winding diameter. The first roller 43 is located.

  As the electrode sheet S is closer to the winding center, the winding warpage tends to be stronger. In this embodiment, as the winding diameter of the electrode sheet S wound around the electrode roll 42 becomes smaller, the first roller 43 is reversely warped. The angle θ <b> 1 is increased by the movement of the first roller 43. The reverse warp contact angle θ1 when the first roller 43 is located at the first position is 150 °, and the reverse warp contact angle θ1 when the first roller 43 is located at the second position is 160 °. When the first roller 43 is positioned at the second position, the reverse warp contact angle θ2 of the second roller 44 increases from 90 ° to 110 °. Accordingly, when the first roller 43 is positioned at the second position, the total sum of the reverse warp contact angles is 530 °. When the 1st roller 43 is located in the 2nd position, compared with the time when the 1st roller 43 is located in the 1st position, the position of the drawing start of electrode sheet S in electrode roll 42 becomes high. In the present embodiment, although not shown, a winding diameter detecting means for detecting the winding diameter of the electrode sheet S wound around the electrode roll 42, and a roller moving means according to a detection signal of the winding diameter detecting means. A control device is provided for controlling the above. In the present embodiment, a configuration in which the first roller 43 is moved upward in the vertical direction so as to increase only the reverse warp contact angle θ1 may be employed. In this case, the lower position is set as the first position, and the position above the first position is set as the second position.

According to this embodiment, there exists an effect equivalent to the reference example 1. FIG .
Moreover, the winding diameter of the electrode sheet S decreases as the electrode sheet S is pulled out, and the first roller 43 moves in accordance with the decrease in the winding diameter, thereby increasing the reverse warp contact angle θ1. For this reason, the total sum of the reverse warp contact angles increases, and the strong winding warp generated in the electrode sheet S can be corrected.

(Second Embodiment)
An electrode manufacturing apparatus and an electrode manufacturing method using the electrode manufacturing apparatus according to the second embodiment will be described. In this embodiment, ten rollers are used, and the total sum of the reverse warp contact angles is set larger than that in Reference Example 1 . Reference Example 1 are given to the same configuration as the aid of the description of Example 1, used in common codes.

  As shown in FIG. 7, the plurality of rollers 61 to 70 are arranged in order from the upstream side to the downstream side of the drawing path of the electrode sheet S. In the present embodiment, the most upstream roller is the first roller 61, and the second roller 62, the third roller 63, the fourth roller 64, the fifth roller 65, the sixth roller 66, the seventh roller 67, and the eighth roller in order. The roller 68 and the ninth roller 69 are used, and the most downstream roller in the drawing path of the electrode sheet S is the tenth roller 70. The rotation axis of the first roller 61 to the tenth roller 70 is parallel to the axis of the electrode roll 42. The first roller 61 to the tenth roller 70 are rollable and are arranged so as to surround the electrode roll 42. In the present embodiment, a driving roller (not shown) for pulling out the electrode sheet S is provided on the downstream side of the first roller 61 to the tenth roller 70. For convenience of explanation, the left in FIG. 7 is the front and the right is the rear.

  In the present embodiment, the position where the electrode sheet S starts to be pulled out in the electrode roll 42 is below the electrode roll 42, and the first roller 61 is located at a position where the electrode sheet S is directed obliquely forward and upward from the position where the electrode roll S is started. Has been placed. A second roller 62 is disposed below the first roller 61, and a third roller 63 is disposed behind the second roller 62. A fourth roller 64 is disposed above the third roller 63, and a fifth roller 65 is disposed in front of the fourth roller 64 and substantially above the first roller 43. A sixth roller 66 is disposed below the fifth roller 65, and a seventh roller 67 is disposed behind the sixth roller 66. An eighth roller 68 is disposed above the seventh roller 67, and a ninth roller 69 is disposed in front of the eighth roller 68 and substantially above the fifth roller 65. A tenth roller 70 is disposed obliquely below and in front of the ninth roller 69. Accordingly, the lead-out path of the electrode sheet S is a path that goes around the electrode roll 42 approximately twice.

  In the present embodiment, the electrode sheet 42 is pulled out so as to contact the first roller 61 to the ninth roller 69 in order in the direction opposite to the direction of curling in the direction opposite to the direction of winding warp by the rotation of the electrode roll 42 and the driving roller. Accordingly, among the plurality of rollers 61 to 70 that are continuously arranged, the first roller 61 to the ninth roller 69 are used as correction rollers that correct the winding warp in a direction opposite to the direction of the electrode sheet S winding. Equivalent to. On the other hand, the electrode sheet S is pulled out so as to come into contact with the tenth roller 70 on the most downstream side in the drawing path of the electrode sheet S while warping in the same direction as the direction of curling. Accordingly, the tenth roller 70 corresponds to a feed roller that warps the electrode sheet S in the same direction as the direction of curling.

The first roller 61 to the ninth roller 69 are in contact with the electrode sheet S while being warped in the direction opposite to the direction of warping of the electrode sheet S. A contact range with the electrode sheet S exists in the first roller 61 to the ninth roller 69. The contact range is a range in the circumferential direction in which the electrode sheet S is in contact with the outer peripheral surfaces of the first roller 61 to the ninth roller 69. Depending on the contact range of the first roller 61 to the ninth roller 69, reverse warp contact angles θ1 to θ9 corresponding to the first roller 61 to the ninth roller 69 are defined. In the present embodiment, the reverse warp contact angle θ1 of the first roller 61 is 150 °. Further, the reverse warp contact angle θ2 of the second roller 62, the reverse warp contact angle θ3 of the third roller 63, the reverse warp contact angle θ4 of the fourth roller 64, the reverse warp contact angle θ5 of the fifth roller 65, and the sixth roller 66 The reverse warp contact angle θ6 of the seventh roller 67, the reverse warp contact angle θ7 of the seventh roller 67, and the reverse warp contact angle θ8 of the eighth roller 68 are all 90 °. Furthermore, the reverse warp contact angle θ9 of the ninth roller 69 is 80 °. Therefore, the total sum of the reverse warp contact angles is 860 °.

  The tenth roller 70 is in contact with the electrode sheet S while being warped in the same direction as that of the electrode sheet S. In the 10th roller 70, the contact range with the electrode sheet S exists. The contact range is a range in the circumferential direction in which the electrode sheet S contacts on the roller outer peripheral surface of the tenth roller 70. The forward warping contact angle θ10 corresponding to the tenth roller 70 is defined by the contact range of the tenth roller 70. In this embodiment, the forward warpage contact angle θ10 of the tenth roller 70 is 80 °, and the total forward warpage contact angle is 80 °. Here, when the sum of the reverse warp contact angles 860 ° and the sum of the forward warp contact angles 80 ° is subtracted, the reverse warp contact angle becomes 780 °.

  In the present embodiment, a preset angle of 360 ° is set in advance for the sum of the reverse warp contact angles and the difference between the reverse warp contact angle and the forward warp contact angle. Therefore, in this embodiment, the total sum 860 ° of the reverse warpage contact angle exceeds a preset setting angle 360 °, and the difference between the total sum 860 ° of the reverse warpage contact angle and the forward warpage contact angle 80 ° is 780 °. And the set angle exceeds 360 °. The sum of the reverse warp contact angles is larger than the set angle, the sum of the reverse warp contact angles is larger than the forward warp contact angle, and the difference between the reverse warp contact angle and the forward warp contact angle is set larger than the set angle. . Accordingly, when the electrode sheet S is pulled out from the first roller 61 through the tenth roller 70, the warping of the electrode sheet S is corrected.

According to this embodiment, there exists an effect equivalent to the reference example 1. FIG .
In this embodiment, the total sum of the reverse warp contact angles is 860 °, and the difference between the total sum of the reverse warp contact angles 860 ° and the total sum of the forward warp contact angles 80 ° is the reverse warp contact angle 780 °. . For this reason, compared with the reference example 1 , the electrode sheet S is sufficiently warped in the opposite direction to the winding warp, and the warping can be more reliably corrected.

  The present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the gist of the invention. For example, the following modifications may be made.

In the above-described embodiment, the electrode sheet is started to be pulled out from the electrode roll at a position below the electrode roll, and the electrode sheet is directed obliquely upward from the position at which the electrode roll is started. The electrode sheet drawing start position is free in the circumferential direction of the electrode roll, and the electrode sheet drawing direction drawn from the drawing start position is not particularly limited.
In the above embodiment, in the drawer mechanism, the sixth roller or the tenth roller is provided as a feeding roller that warps the electrode sheet in the same direction as the direction of curling, but this is not restrictive. For example, the feeding roller may not be provided, and the correction roller may be arranged in the drawing path. Alternatively, a plurality of delivery rollers may be provided. In this case, the sum of the reverse warp contact angles is larger than the forward warp contact angle, and the difference between the reverse warp contact angle and the forward warp contact angle exceeds the set angle. do it. The upper limit of the difference between the reverse warp contact angle and the forward warp contact angle is set according to the conditions of the electrode sheet, but may be set in a range in which the reverse warp does not remain more than necessary in the drawn electrode sheet. .
In the above embodiment, the sum of the reverse warp contact angles is exemplified as 500 ° or 860 °, but the sum of the reverse warp contact angles is not limited to this. For example, the number of rollers may be increased so that the total sum of the reverse warp contact angles exceeds 860 °, and at least the reverse warp contact angle only needs to be larger than a preset angle. The preset angle set in advance with respect to the reverse warp contact angle is not limited to 360 °. The set angle may be, for example, 360 ° or more, and is changed according to conditions such as the dimensions and materials of the electrode sheet and the winding state on the electrode roll. Similarly, the set angle with respect to the difference between the sum of the reverse warp contact angles and the sum of the forward warp contact angles is also changed according to the conditions such as the dimensions and materials of the electrode sheet and the winding state on the electrode roll.
In the above embodiment, the electrode is obtained by a molding mechanism having a punching device in the molding step, but the molding mechanism may obtain the electrode by a cutting device other than the punching device. For example, a molding mechanism having an abrasive water jet device may be used, and in this case, an electrode sheet can be cut to obtain an electrode by ejecting a high-pressure fluid containing abrasive particles from the abrasive water jet device.

10 Secondary battery 21 Positive electrode 22 Negative electrode 40, 60 Drawer mechanism 41 Molding mechanism 42 Roll shaft 43, 61 First roller 44, 62 Second roller 45, 63 Third roller 46, 64 Fourth roller 47, 65 Fifth roller 48 , 66 6th roller 49 Punching device 67 7th roller 68 8th roller 69 9th roller 70 10th roller S Electrode sheet (for positive electrode)
θ1, θ2, θ3, θ4, θ5, θ6, θ7, θ8 , θ9 , θ10 Contact angle

Claims (5)

An electrode comprising an active material layer on at least one surface of a metal foil, a drawing step for drawing out a wound electrode sheet wound in a roll shape, and a forming step for shaping the drawn electrode sheet into an electrode shape In the manufacturing method of
In the drawing step, the electrode sheet drawn out from the wound state is sequentially brought into contact with a plurality of correction rollers that correct the winding warp in a direction opposite to the direction of winding of the electrode sheet,
When the reverse warp contact angle is defined by the contact range between the correction roller and the electrode sheet, the sum of the reverse warp contact angles exceeds 360 ° ,
The correction roller is moved in a direction to increase the reverse warp contact angle of the correction roller according to a decrease in the winding diameter of the wound electrode sheet wound in the roll shape, and the winding diameter is method for producing a detected by taking diameter detecting means electrode, wherein Rukoto. In the drawing step, the electrode sheet is brought into contact with a feeding roller that warps in the same direction as the direction of the warping,
When a forward warpage contact angle smaller than the reverse warpage contact angle is defined by the contact range of the electrode sheet in the delivery roller,
The method of manufacturing an electrode according to claim 1, wherein a difference between the reverse warpage contact angle and the forward warpage contact angle exceeds 360 ° . An electrode comprising an active material layer on at least one surface of a metal foil, a drawing step for drawing out a wound electrode sheet wound in a roll shape, and a forming step for shaping the drawn electrode sheet into an electrode shape In the manufacturing method of
  In the drawing step, the electrode sheet drawn out from the wound state is sequentially brought into contact with a plurality of correction rollers that correct the winding warp in a direction opposite to the direction of winding of the electrode sheet,
When the reverse warp contact angle is defined by the contact range between the correction roller and the electrode sheet, the sum of the reverse warp contact angles exceeds 360 °,
The electrode sheet pull-out path drawn out from the wound state is a path that circulates around the electrode roll supporting the wound-up electrode sheet wound in a roll shape one or more times. Manufacturing method. An active material layer is provided on at least one surface of the metal foil, and a drawing mechanism for pulling out the wound electrode sheet wound in a roll shape, and a forming mechanism for forming the electrode by cutting or punching from the drawn electrode sheet In an electrode manufacturing apparatus having
  The drawer mechanism is
  An electrode roll that supports the wound electrode sheet wound in the form of a roll;
  A plurality of straightening rollers arranged continuously so that the electrode sheet contacts in turn in the direction opposite to the direction of curling,
  A winding detection means for detecting a winding diameter of the wound electrode sheet wound in a roll;
  Roller moving means for moving the straightening roller,
  When the reverse warp contact angle is defined by the contact range between the correction roller and the electrode sheet, the sum of the reverse warp contact angles exceeds 360 °,
  The said roller moving means moves the said correction roller to the direction which increases the said reverse curvature contact angle in the said correction roller according to the reduction | decrease of the said winding diameter, The manufacturing apparatus of the electrode characterized by the above-mentioned. An active material layer is provided on at least one surface of the metal foil, and a drawing mechanism for pulling out the wound electrode sheet wound in a roll shape, and a forming mechanism for forming the electrode by cutting or punching from the drawn electrode sheet In an electrode manufacturing apparatus having
The drawer mechanism is
An electrode roll that supports the wound electrode sheet wound in the form of a roll;
A plurality of straightening rollers arranged continuously so that the electrode sheet contacts in turn in the direction opposite to the direction of curling, and
When the reverse warp contact angle is defined by the contact range between the correction roller and the electrode sheet, the sum of the reverse warp contact angles exceeds 360 °,
The plurality of correction rollers is five or more,
The rotation axis of the plurality of correction rollers is disposed so as to surround the rotation axis of the electrode roll .

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