JP2016115416A - Device and method for manufacturing electrode - Google Patents

Abstract

PROBLEM TO BE SOLVED: To propose a device and a method for manufacturing an electrode, capable of flattening a protrusion portion (especially, an end high portion) of an electrode paste while suppressing an influence on the electrode paste coated on a belt-like metal foil.SOLUTION: There is provided a device 1 for manufacturing an electrode for flattening a protrusion portion (end high portion Ba) of an electrode paste B coated on a belt-like metal foil A. The device includes a flattening part (a comma roll 10) which is arranged on a conveyance path of the belt-like metal foil A and removes the protrusion portion of the electrode paste B to flatten the removed portion during conveyance of the belt-like metal foil A. The flattening part has a protrusion part (a step 10b) protruding to a conveyance path side, and the protrusion part extends in a direction inclined with respect to a direction orthogonal to a conveyance direction C of the belt-like metal foil A.SELECTED DRAWING: Figure 1

Description

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

  When manufacturing an electrode used for a lithium ion secondary battery or the like, an electrode paste is applied to a strip-shaped metal foil to form an active material layer. The coated electrode paste is required to have surface flatness. However, when the discharge amount of the electrode paste becomes unstable at the start of coating or the like, there is a problem that an end height portion higher than other portions is formed at the end portion of the applied electrode paste. In order to flatten the edge height portion, for example, in Patent Document 1, a slit is disposed on the belt-shaped metal foil conveyance path, and after the surface of the edge height portion is dried, the edge height portion is formed in the slit. It is disclosed that, by applying, the inner paste material is allowed to flow downstream in the process while preventing the end high portion from being deformed, and the end high portion is reduced.

JP, 2014-120293, A

  When the edge height portion is reduced by the slits disclosed in Patent Document 1, the shape loss of the edge height portion is prevented, but the paste material that is flowed downstream in the process is spread and leveled by the slit. Become. For this reason, since the paste material of the edge high part adheres to the surface of the electrode paste applied to the strip-shaped metal foil, the thickness of the applied electrode paste is increased, or the surface of the electrode paste is streaked. Can do.

  Therefore, the present invention provides an electrode manufacturing apparatus and an electrode manufacturing method capable of flattening the protruding portion (particularly, the end height portion) of the electrode paste while suppressing the influence on the electrode paste applied to the strip-shaped metal foil. The challenge is to propose.

  An electrode manufacturing apparatus according to one aspect of the present invention is an electrode manufacturing apparatus for flattening a protruding portion of an electrode paste applied to a strip-shaped metal foil, and is disposed on a transport path of the strip-shaped metal foil. , Including a flattening portion that removes and flattenes the protruding portion of the electrode paste during conveyance of the belt-shaped metal foil, the flattening portion has a convex portion protruding toward the conveyance path side, the convex portion is It extends in a direction inclined with respect to the direction orthogonal to the conveying direction of the strip-shaped metal foil.

  In this manufacturing apparatus, the protruding portion of the electrode paste is removed by the convex portion inclined with respect to the direction orthogonal to the transport direction of the strip-shaped metal foil. Therefore, the removed electrode paste of the protruding portion is not attached to the surface of the electrode paste applied to the strip-shaped metal foil. Thereby, the manufacturing apparatus can planarize a protrusion part (especially edge height part), suppressing the influence on the electrode paste apply | coated to the strip | belt-shaped metal foil. The convex portion is a portion protruding from the surface of the flattened portion, and includes a stepped portion.

  The electrode manufacturing apparatus according to an embodiment includes a recovery unit that recovers the electrode paste at the protruding portion removed by the planarization unit. With this configuration, the manufacturing apparatus can recover the removed electrode paste in the recovery unit.

  In the electrode manufacturing apparatus according to one embodiment, the flattening portion is a comma roll, and the convex portion is a step portion of the comma roll. With this configuration, the manufacturing apparatus removes the protruding portion from the one end side in the width direction to the other end side with the stepped step of the comma roll.

  In the electrode manufacturing apparatus according to one embodiment, the flattening unit is a gravure roll, and the gravure roll has a plurality of convex portions, and a groove between the convex portions and the convex portions is orthogonal to the conveyance direction. It extends in a direction that is inclined with respect to the direction of movement. With this configuration, the manufacturing apparatus removes the protruding portion by the inclined groove of the gravure roll.

  An electrode manufacturing method according to one aspect of the present invention is an electrode manufacturing method including a coating step of applying an electrode paste to a strip-shaped metal foil, and is performed during the transport of the strip-shaped metal foil. The removal step of removing the protruding portion of the coated electrode paste with a convex portion inclined with respect to the direction orthogonal to the transport direction of the strip-shaped metal foil, and collecting the electrode paste of the protruding portion removed in the removal step A recovery step.

  In this manufacturing method, the protruding portion of the electrode paste is removed by the convex portion inclined with respect to the direction orthogonal to the transport direction, and the electrode paste of the removed protruding portion is collected. It does not adhere to the surface of the electrode paste coated on the strip-shaped metal foil. Thereby, the manufacturing method can planarize a protrusion part (especially edge height part), suppressing the influence on the electrode paste applied to the strip | belt-shaped metal foil.

  In the electrode manufacturing method of one embodiment, in the coating process, an electrode paste is intermittently applied to a strip-shaped metal foil. In intermittent coating, since the discharge start and discharge end of the electrode paste are repeated at a constant period, the discharge amount of the electrode paste tends to become unstable. For this reason, the electrode paste applied to the strip-shaped metal foil at regular intervals is likely to have a high end. Therefore, it is effective when this electrode manufacturing method is applied when intermittent coating is performed in the coating process.

  ADVANTAGE OF THE INVENTION According to this invention, a protrusion part (especially edge high part) can be planarized, suppressing the influence on the electrode paste apply | coated to the strip | belt-shaped metal foil.

It is a figure which shows typically the manufacturing apparatus of the electrode which concerns on 1st Embodiment. It is a perspective view of the comma roll shown in FIG. It is a figure which shows the flow of operation | movement of the manufacturing apparatus of the electrode which concerns on 1st Embodiment, Fig.3 (a) is the time of a removal start, FIG.3 (b) is under removal, FIG.3 (c) and FIG. 3 (d) is being recovered. It is a figure which shows typically the manufacturing apparatus of the electrode which concerns on 2nd Embodiment. FIG. 5 is a perspective view of the gravure roll shown in FIG. 4. It is a figure which shows the flow of operation | movement of the manufacturing apparatus of the electrode which concerns on 2nd Embodiment, Fig.6 (a) is under removal, FIG.6 (b) is after removal, FIG.6 (c) is after transcription | transfer. FIG. 6 (d) is being collected.

  Hereinafter, an electrode manufacturing apparatus and an electrode manufacturing method according to embodiments of the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected about the element which is the same or it corresponds in each figure, and the overlapping description is abbreviate | omitted.

  The electrode manufacturing apparatus according to the present embodiment is an apparatus that removes an end height portion (protruding portion) of an electrode paste intermittently applied in an electrode coating process. The first embodiment is a form using a comma roll, and the second embodiment is a form using a gravure roll. The manufactured electrode is used for power storage devices such as a secondary battery and an electric double layer capacitor. The secondary battery is, for example, a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery. Moreover, the manufactured electrode may be used for a primary battery. In this embodiment, it is assumed that an electrode used for a lithium ion secondary battery is manufactured.

  The electrode has an active material layer formed by applying an electrode paste on at least one surface of a metal foil. The electrode has a tab on which an active material layer is not formed at the end of the metal foil. The metal foil is, for example, an aluminum foil in the case of the positive electrode, and a copper foil or a nickel foil in the case of the negative electrode. The electrode paste is in the form of a slurry having a predetermined viscosity and includes an active material, a binder, a solvent, and the like. The active material is a positive electrode active material or a negative electrode active material. The positive electrode active material is, for example, a composite oxide or a sulfur-based material. The composite oxide includes at least one of manganese, nickel, cobalt, and aluminum and lithium. Examples of the negative electrode active material include graphite, highly oriented graphite, carbon such as mesocarbon microbeads, hard carbon, and soft carbon, alkali metals such as lithium and sodium, metal compounds, and SiOx (0.5 ≦ x ≦ 1.5). ) And the like, and boron-added carbon. The binder is, for example, a fluorine-containing resin such as polyvinylidene fluoride, polytetrafluoroethylene, or fluorine rubber, a thermoplastic resin such as polypropylene or polyethylene, an imide resin such as polyimide or polyamideimide, or an alkoxysilanol group-containing resin. Examples of the solvent include organic solvents such as NMP (N-methylpyrrolidone), methanol, and methyl isobutyl ketone, and water. The electrode paste may contain a conductive auxiliary such as carbon black, graphite, acetylene black, and ketjen black (registered trademark). The electrode paste may contain a thickening agent such as carboxymethylcellulose (CMC).

  When producing an electrode, a kneading step for kneading each of the above substances to produce an electrode paste, a coating step for intermittently applying the electrode paste to a strip-shaped metal foil, a drying step for drying the intermittently applied electrode paste, etc. Thus, an active material layer is formed on the strip-shaped metal foil. And an electrode is cut out from the strip | belt-shaped metal foil in which this active material layer was formed.

  With reference to FIG.1 and FIG.2, the manufacturing apparatus 1 of the electrode which concerns on 1st Embodiment is demonstrated. FIG. 1 is a diagram schematically illustrating an electrode manufacturing apparatus 1 according to the first embodiment. FIG. 2 is a perspective view of a comma roll provided in the manufacturing apparatus 1.

  The process of removing the edge height portion using the manufacturing apparatus 1 and the coating process of the preceding process are performed during the transport of the strip-shaped metal foil A. Prior to transport, the strip-shaped metal foil A is in the form of a roll (unwinding roll) wound up on a reel (not shown). During conveyance, the strip-shaped metal foil A is fed out from the unwinding roll, and the strip-shaped metal foil A on which the active material layer is formed is wound around a reel (not shown) to form a roll (winding roll). The strip-shaped metal foil A is conveyed from the unwinding roll to the winding roll through a predetermined conveyance path. The strip-shaped metal foil A is transported at a predetermined transport speed. A predetermined tension (tension) is applied to the strip-shaped metal foil A being conveyed. In FIG. 1, the direction in which the strip-shaped metal foil A is conveyed is indicated by the arrow C. This conveyance direction C is substantially orthogonal to the width direction of the strip-shaped metal foil A to be conveyed.

  Before describing the manufacturing apparatus 1, the coating process will be described. A coating process is performed by the die-type coating apparatus 3 shown in FIG. 1, for example. The coating apparatus 3 includes a coating gun 30, a backup roll 31, and the like. An electrode paste stored in a tank (not shown) is fed into the coating gun 30 by a pump (not shown). The backup roll 31 is disposed to face the discharge port 30 a of the coating gun 30. The coating gun 30 discharges the electrode paste from the discharge port 30 a to the strip-shaped metal foil A that is conveyed while being supported by the backup roll 31. In particular, the coating apparatus 3 applies the electrode paste to the strip-shaped metal foil A at regular intervals by intermittent coating. The intermittent coating is performed by stopping the discharge of the electrode paste from the coating gun 30 at regular intervals. The intermittent coating may be performed by moving the coating gun 30 back and forth with respect to the backup roll 31 or by moving the backup roll 31 back and forth with respect to the coating gun 30.

  When discharging the electrode paste with the coating gun 30 or the like, pressure is applied to the electrode paste to push out the electrode paste. Therefore, the discharge amount tends to become unstable at the start and end of discharge of the electrode paste. When the discharge amount becomes unstable (when the discharge amount is slightly larger than the constant discharge amount during discharge), a flat portion of the surface is formed at the end of the surface of the electrode paste B applied to the strip-shaped metal foil A. A protruding portion (hereinafter referred to as an end height portion) is formed. In the case of the example illustrated in FIG. 1, the end height portion Ba is formed at the start end portion (the end portion on the downstream side in the transport direction C) of the electrode paste B. In the case where the end height portion can be the terminal portion (the upstream end portion in the transport direction C) of the electrode paste B, the end height portion may be both the start end portion and the end portion. In addition, there are other factors such as the surface tension of the electrode paste as a factor for forming the edge height portion. Further, when intermittent coating is performed by moving the backup roll 31 or the like back and forth, the thickness of the electrode paste B tends to become unstable at the start or end of transfer of the electrode paste to the metal foil A.

  In particular, in intermittent coating, the discharge start and discharge end of the electrode paste are repeated at regular intervals. As a result, an electrode paste B having a substantially rectangular pattern is formed on the strip-shaped metal foil A at regular intervals (see FIG. 3). Therefore, in the case of intermittent coating, there is a possibility that end height portions Ba are formed in the electrode paste B at regular intervals. When the electrode is manufactured, since the flatness (thickness uniformity) of the surface of the electrode paste B (the surface of the active material layer) is required, the edge height portion Ba (excess electrode paste) is removed from the surface of the electrode paste B. It needs to be removed and flattened. Therefore, in the manufacturing apparatus 1, immediately after the coating process, the end height portion Ba is removed from the electrode paste B intermittently applied to the strip-shaped metal foil A and flattened.

  In addition, although applied to the die method in this embodiment, other coating methods such as a comma roll method using a comma roll and a gravure method using a gravure roll are also applicable. In the case of other coating methods, an end height portion may be formed at the end of the surface of the coated electrode paste. Moreover, although applied to intermittent coating in this embodiment, it is applicable also to continuous coating. In continuous coating, there may be a case where an end height portion is formed at the start end portion, the end end portion, or the like of the electrode paste that has been continuously applied. In the example shown in FIG. 1, the electrode paste is applied to one surface of the strip-shaped metal foil A, but the present invention can also be applied to the case where the electrode paste is applied to both surfaces of the strip-shaped metal foil A. . When applied to both sides, an electrode paste is applied to one side of the strip-shaped metal foil A, and after the applied electrode paste is dried, the electrode paste is applied to the other side of the strip-shaped metal foil A. The

  Now, the manufacturing apparatus 1 will be described. The manufacturing apparatus 1 removes the edge height portion Ba from the electrode paste B intermittently applied to the band-shaped metal foil A during the conveyance of the band-shaped metal foil A, and flattens it. In particular, the manufacturing apparatus 1 uses a comma roll to remove the end height portion Ba. In the manufacturing apparatus 1, the end height portion Ba is removed from one end side in the width direction of the metal foil A to the other end side by the step of the comma roll, and the electrode paste of the removed end height portion Ba is moved to the other end side. Collect at the end. For this purpose, the manufacturing apparatus 1 includes a comma roll 10, a backup roll 11, and a collection container 12.

  The comma roll 10 is a comma roll for removing the end height portion Ba from one end side in the width direction of the metal foil A to the other end side and bringing the electrode paste of the removed end height portion Ba toward the other end side. . The comma roll 10 is made of metal. The comma roll 10 has a substantially cylindrical shape. The comma roll 10 has a width wider than the width of the electrode paste B applied to the strip-shaped metal foil A. A step 10 b is provided on the peripheral surface 10 a of the comma roll 10. The step 10b extends in a direction inclined at a predetermined angle upstream of the transport direction C with respect to a direction orthogonal to the transport direction C (the width direction of the strip-shaped metal foil A being transported (the axial direction of the comma roll 10)). doing. This predetermined angle is appropriately set in consideration of the conveyance speed of the strip-shaped metal foil A, the coating width of the electrode paste, the viscosity of the electrode paste, and the like. The predetermined angle is, for example, 5 ° to 45 ° with respect to the direction orthogonal to the conveyance direction C, and more preferably 10 ° to 30 °. If the predetermined angle is less than 5 °, there is a possibility that the thickness of the electrode paste B becomes thicker or streaks or the like may be formed on the surface of the electrode paste B. Further, if the predetermined angle is larger than 45 °, the removed electrode paste of the end height portion Ba may not move in the width direction, and the removed electrode paste may adhere to the surface of the electrode paste B.

  The comma roll 10 is disposed on the downstream side of the coating gun 30 on the transport path of the strip-shaped metal foil A and above the strip-shaped metal foil A being transported. In particular, the comma roll 10 is disposed such that the step 10b is located at the lower end as shown in FIG. Therefore, the step 10b is a convex shape protruding toward the transport path side of the strip-shaped metal foil A. In the arrangement of the comma roll 10, a slight gap is formed between the tip 10c of the step 10b and the surface of the electrode paste B (assuming the average thickness electrode paste B) applied to the metal foil A. The height position of the comma roll 10 is adjusted. Moreover, the comma roll 10 is arrange | positioned so that the side where the diameter of the surrounding surface 10a becomes small in the level | step difference 10b may become the downstream of the conveyance direction C, as shown in FIG. The comma roll 10 does not rotate and is fixed.

  The step 10b is inclined at a predetermined angle with respect to the direction orthogonal to the transport direction C. Therefore, with the movement of the strip-shaped metal foil A in the transport direction C, the end height portion Ba of the electrode paste B applied to the strip-shaped metal foil A gradually increases from one end in the width direction to the other end. It hits the step 10b. The part that collides is the part of the peripheral surface 10a on the upstream side of the step 10b. The electrode paste of the end high portion Ba that hits the step 10b is pushed to the other end side by the inclined step 10b and gradually pushed away from the surface of the electrode paste B. The electrode paste of the pushed end high portion Ba is brought closer to the other end side by the inclined step 10b. Accordingly, the step 10b becomes a portion where the electrode paste of the end high portion Ba is pushed away from one end portion to the other end portion, and becomes a portion where the pushed electrode paste is brought closer to the other end side.

  The backup roll 11 is a backup roll for supporting the strip-shaped metal foil A from below when the end height portion Ba is removed by the comma roll 10. The backup roll 11 is made of metal. The backup roll 11 has a cylindrical shape. The backup roll 11 is disposed on the downstream side of the backup roll 31 and below the belt-shaped metal foil A being conveyed. In particular, the backup roll 11 is disposed at a position facing the comma roll 10. The backup roll 11 is freely rotatable.

  The collection container 12 is a container that collects the electrode paste of the end height portion Ba that has been dropped by the comma roll 10 toward the other end. The collection container 12 is a rectangular parallelepiped container, for example. The upper end of the collection container 12 is open. The collection container 12 is disposed on the downstream side of the backup roll 31 and on the side of the belt-shaped metal foil A being conveyed. In particular, the collection container 12 is disposed at a position where the electrode paste dropped by the step 10 b of the comma roll 10 enters.

  The operation of the manufacturing apparatus 1 will be described with reference to FIG. FIG. 3 is a diagram showing a flow of operations of the manufacturing apparatus 1. In FIG. 3, the electrode paste of the end high portion Ba is drawn in gray. In FIG. 3, the electrode paste removed by the comma roll 10 is denoted by reference symbol Ba ′. 3 (a) to 3 (c) are views of the strip-shaped metal foil A being transported as viewed from above, and FIG. 3 (d) is a diagram of the strip-shaped metal foil A being transported as viewed from the side. It is. 3 (a) to 3 (c), the strip-shaped metal foil A is gradually moving in the transport direction C, and in FIG. 3 (d), the strip-shaped metal foil A is at the same position as FIG. 3 (c). .

  The strip-shaped metal foil A is transported in the transport direction C at a predetermined transport speed. The coating gun 30 coats the electrode paste on a surface of the belt-shaped metal foil A being conveyed for a predetermined time every predetermined time (coating process). Thereby, the strip-shaped metal foil A is coated with the electrode paste B having a substantially rectangular pattern at regular intervals. In the example shown in FIG. 3, an end height portion Ba is formed at the start end portion of the surface of the electrode paste B.

  Since the strip-shaped metal foil A moves in the transport direction C, the end height portions Ba of the electrode paste B applied to the strip-shaped metal foil A at regular intervals sequentially reach the lower side of the comma roll 10. As shown in FIG. 3A, one end of the end height portion Ba in the width direction first hits the step 10 b of the comma roll 10.

  Due to the movement of the strip-shaped metal foil A in the transport direction C, as shown in FIG. 3B, the other end side of the end height portion Ba is gradually inclined with respect to the direction perpendicular to the transport direction C. Bump into a step 10b. Thereby, the other end side from the one end part of the edge high part Ba is gradually pushed away from the surface of the electrode paste B by the level | step difference 10b (removal process). The electrode paste Ba 'of the pushed end high portion Ba is brought closer to the other end side by the step 10b. Eventually, everything from one end of the end height portion Ba to the other end is pushed away by the step 10b. Then, the electrode paste Ba 'of the pushed end high portion Ba is brought close to the other end portion of the surface of the electrode paste B by the step 10b. Thereby, the end high portion Ba is removed from the surface of the electrode paste B and flattened.

  Further, as shown in FIGS. 3C and 3D, the electrode paste Ba 'brought to the other end gradually falls downward. The dropped electrode paste Ba 'enters the recovery container 12 and is recovered (recovery process). Then, all the removed electrode paste Ba ′ is collected in the collection container 12. Thus, the electrode paste Ba ′ removed from the surface of the electrode paste B is brought to the other end by the step 10 b of the comma roll 10 and collected. Therefore, the removed electrode paste Ba ′ does not adhere to the surface of the electrode paste B. Therefore, the thickness of the electrode paste B (active material layer) as a product is not increased by the electrode paste Ba ', and no streaks are formed on the surface of the electrode paste B. Since the thickness of the electrode paste B does not increase, the basis weight (weight) of the electrode paste B does not exceed a predetermined amount.

  According to this electrode manufacturing apparatus 1, by arranging the step 10b of the comma roll 10 to be inclined with respect to the direction orthogonal to the transport direction C, the end height portion Ba is moved from one end side to the other end in the width direction at the step 10b. The electrode paste Ba ′ of the end height portion Ba that has been pushed away can be moved toward the other end side, and the electrode paste Ba ′ can be recovered at the other end side. Thereby, the manufacturing apparatus 1 can remove and planarize the end height portion Ba while suppressing the influence on the electrode paste B applied to the strip-shaped metal foil A. As a result, the manufacturing apparatus 1 can improve the flatness of the surface of the electrode paste B. Even when a protruding portion protruding from the flat portion is formed on the portion other than the end portion of the surface of the electrode paste B, the manufacturing apparatus 1 removes the protruding portion while suppressing the influence on the electrode paste B. And can be flattened.

  With reference to FIG.4 and FIG.5, the manufacturing apparatus 2 of the electrode which concerns on 2nd Embodiment is demonstrated. FIG. 4 is a view schematically showing the electrode manufacturing apparatus 2 according to the second embodiment. FIG. 5 is a perspective view of a gravure roll (roll having slanted line-shaped continuous grooves) provided in the manufacturing apparatus 2.

  The manufacturing apparatus 2 removes the edge height portion Ba from the electrode paste B applied to the band-shaped metal foil A during the conveyance of the band-shaped metal foil A, and flattens it. In particular, the manufacturing apparatus 2 uses a gravure roll to remove the end height portion Ba. In the manufacturing apparatus 2, the end height portion Ba is removed by continuous grooves of a constant pattern of the gravure roll, and the electrode paste of the removed end height portion Ba is transferred to another roll and collected. Therefore, the manufacturing apparatus 2 includes a gravure roll 20, a backup roll 21, a transfer roll 22, a scraper 23, and a collection container 24.

  The gravure roll 20 is a gravure roll for removing the electrode paste at the end high portion Ba from one end to the other end in the width direction of the metal foil A and carrying the removed electrode paste to the transfer roll 22. The gravure roll 20 is made of metal. The gravure roll 20 has a width wider than the width of the electrode paste B applied to the strip-shaped metal foil A. The gravure roll 20 has a shape in which a gravure pattern (a hatched groove 20b arranged at regular intervals) is provided on the surface of a cylinder. This gravure pattern is an uneven pattern as shown in FIG. The groove 20b is a concave portion between one convex portion and the other convex portion that are adjacent to each other in the concavo-convex pattern. In particular, this concavo-convex pattern is inclined at a predetermined angle on the upstream side in the transport direction C with respect to the direction orthogonal to the transport direction C (the width direction of the strip-shaped metal foil A being transported (the axial direction of the gravure roll 20)). ing. Therefore, the groove 20b inclined with respect to the direction orthogonal to the conveyance direction C extends on the circumferential surface 20a of the gravure roll 20 at regular intervals. The cross-sectional shape of the groove 20b may be an appropriate shape such as a trapezoidal shape, a rectangular shape, a V shape, or a U shape. The predetermined angle is appropriately set in consideration of the conveying speed of the strip-shaped metal foil A, the coating width of the electrode paste, the viscosity of the electrode paste, and the like. The predetermined angle is, for example, 5 ° to 45 ° with respect to the direction orthogonal to the conveyance direction C, and more preferably 10 ° to 30 °.

  The gravure roll 20 is disposed on the downstream side of the coating gun 30 on the transport path of the strip-shaped metal foil A and above the strip-shaped metal foil A being transported. In the arrangement of the gravure roll 20, the height position of the gravure roll 20 is adjusted so that a slight gap is formed between the convex portion of the peripheral surface 20 a and the surface of the electrode paste B applied to the metal foil A. Is done. The gravure roll 20 is freely rotatable. The gravure roll 20 is rotationally driven at a constant rotational speed by a motor (not shown) or the like. This rotational speed is appropriately set according to the diameter of the gravure roll 20, the transport speed of the strip-shaped metal foil A, and the like. Since the gravure roll 20 rotates, the groove 20b located at the lower end of the gravure roll 20 changes sequentially.

  The groove 20b is inclined at a predetermined angle with respect to a direction orthogonal to the conveyance direction C. The electrode paste of the end high portion Ba reaching the groove 20b enters the groove 20b and is peeled off from the surface of the electrode paste B. At this time, the electrode paste from one end portion in the width direction of the end height portion Ba to the other end portion is divided into a plurality of grooves 20b. Since the gravure roll 20 is rotating, the electrode paste that has entered the groove 20b is separated from the surface of the electrode paste B in accordance with the rotational movement of the groove 20b. The electrode paste that has entered the groove 20b is carried to the transfer roll 22 as the gravure roll 20 rotates. Therefore, the groove 20b becomes a portion for stripping the electrode paste of the end high portion Ba from one end portion to the other end portion, and also a portion for carrying the stripped electrode paste. In addition, when the amount of the electrode paste in the end high portion Ba is large and does not fit in the groove 20b, the electrode paste that does not fit moves from one end portion in the width direction to the other end side due to the inclination of the groove 20b. The electrode paste that does not fit in the groove 20b is peeled off at the next groove 20b that comes in contact with the gravure roll 20 or moves further to the other end. Thereby, the electrode paste of the end high portion Ba moves to the other end side even when the electrode paste is peeled off by the plurality of grooves 20b or not peeled off.

  The backup roll 21 is a backup roll for supporting the strip-shaped metal foil A from below when the end height portion Ba is removed by the gravure roll 20. The backup roll 21 is the same backup roll as the backup roll 11 of the first embodiment. In particular, the backup roll 21 is disposed at a position facing the gravure roll 20.

  The transfer roll 22 is a transfer roll to which the electrode paste contained in the groove 20b of the gravure roll 20 is transferred. At least the surface of the transfer roll 22 is made of a material to which the electrode paste is easily transferred, for example, rubber. The transfer roll 22 has a cylindrical shape. The transfer roll 22 has the same width as that of the gravure roll 20. The transfer roll 22 is disposed on the upstream side of the gravure roll 20 and above the gravure roll 20. In particular, the transfer roll 22 is disposed such that the peripheral surface 22 a is in contact with the peripheral surface 20 a of the gravure roll 20. The transfer roll 22 is freely rotatable. The transfer roll 22 is rotationally driven at a constant rotational speed by a motor (not shown) or the like. This rotational speed is appropriately set according to the rotational speed of the gravure roll 20, the ratio between the diameter of the gravure roll 20 and the diameter of the transfer roll 22, and the like. The rotation direction of the transfer roll 22 is the same as the rotation direction of the gravure roll 20.

  The scraper 23 is a scraper for scraping off the electrode paste transferred to the transfer roll 22. The scraper 23 has a width approximately the same as the width of the transfer roll 22. The scraper 23 is arranged on the upstream side of the transfer roll 22 and at the same height as the transfer roll 22. In particular, the scraper 23 is disposed so that the tip portion is in contact with the peripheral surface 22 a of the transfer roll 22.

  The collection container 24 is a container for collecting the electrode paste of the end high portion Ba scraped off by the scraper 23. The collection container 24 is, for example, a rectangular parallelepiped container. In particular, the collection container 24 is a container having a width wider than the width of the scraper 23. The upper end of the collection container 24 is open. The collection container 24 is disposed below the contact portion between the scraper 23 and the transfer roll 22 so that the electrode paste dropped by the scraper 23 can enter.

  The operation of the manufacturing apparatus 2 will be described with reference to FIG. FIG. 6 is a diagram showing a flow of operations of the manufacturing apparatus 2. In FIG. 6, the electrode paste of the end high portion Ba is drawn in gray. In FIG. 6, the electrode paste removed by the gravure roll 20 is denoted by reference numeral Ba ′. FIG. 6A to FIG. 6D are views of the band-shaped metal foil A being conveyed as viewed from the side. In Fig.6 (a)-FIG.6 (d), the strip | belt-shaped metal foil A moves to the conveyance direction C gradually, and the gravure roll 20 and the transfer roll 22 are rotating gradually. Since the coating process similar to that of the first embodiment is performed in the second embodiment, the description of the coating process is omitted.

  Since the strip-shaped metal foil A moves in the conveying direction C, the end height portions Ba of the electrode paste B applied to the strip-shaped metal foil A at regular intervals sequentially reach the lower part of the gravure roll 20. As shown in FIG. 6A, the reached electrode paste of the end height portion Ba enters the groove 20b of the gravure roll 20 and is peeled off from the surface of the electrode paste B (removal step). Since the gravure roll 20 is rotating, as shown in FIG. 6B, the electrode paste Ba 'that has entered the groove 20b is carried to the transfer roll 22 side. As a result, the end height portion Ba is removed from the electrode paste B and flattened. The removal of the end height portion Ba by the groove 20b is performed by the plurality of grooves 20b.

  Eventually, the electrode paste Ba ′ entering the groove 20 b reaches the transfer roll 22. One end of the electrode paste Ba ′ in the groove 20 b in the width direction first hits the peripheral surface 22 a of the transfer roll 22. By rotation of the gravure roll 20 and the transfer roll 22, the other end side of the electrode paste Ba 'in the groove 20b gradually comes into contact with the peripheral surface 22a. As a result, the electrode paste Ba ′ in the groove 20 b is gradually transferred to the peripheral surface 22 a of the transfer roll 22. Eventually, as shown in FIG. 6C, all the electrode paste Ba ′ in the groove 20 b is transferred to the transfer roll 22. Since the transfer roll 22 is rotating, the electrode paste Ba 'transferred to the transfer roll 22 is carried to the scraper 23 side.

  Eventually, the electrode paste Ba ′ transferred to the transfer roll 22 reaches the tip of the scraper 23. As shown in FIG. 6D, the electrode paste Ba ′ transferred to the transfer roll 22 is gradually scraped off by the rotation of the transfer roll 22. The dropped electrode paste Ba 'enters the recovery container 24 and is recovered (recovery process). Then, all of the scraped electrode paste Ba 'is collected in the collection container 24. As described above, the electrode paste Ba ′ removed from the surface of the electrode paste B is sequentially conveyed by the gravure roll 20 and the transfer roll 22 and collected. Therefore, the removed electrode paste Ba ′ does not adhere to the surface of the electrode paste B.

  According to the electrode manufacturing apparatus 2, the groove 20b of the gravure roll 20 is disposed so as to be inclined with respect to the direction orthogonal to the transport direction C, whereby the end height portion Ba is shifted from one end in the width direction to the other end in the groove 20b. The electrode paste Ba ′ of the peeled end height portion Ba can be separated from the surface of the electrode paste B. Further, according to the manufacturing apparatus 2, the electrode paste Ba ′ in the groove 20 b of the gravure roll 20 can be collected by providing the transfer roll 22 and the scraper 23. Thereby, the manufacturing apparatus 2 can remove and planarize the end height portion Ba while suppressing the influence on the electrode paste B applied to the strip-shaped metal foil A. As a result, the manufacturing apparatus 2 can improve the flatness of the surface of the electrode paste B. Even when a protruding portion protruding from the flat portion is formed on the portion other than the end portion of the surface of the electrode paste B, the manufacturing apparatus 2 removes the protruding portion while suppressing the influence on the electrode paste B. And can be flattened.

  As mentioned above, although embodiment of this invention was described, it is implemented in various forms, without being limited to the said embodiment.

  For example, in the above-described embodiment, the flattening portion is configured by a comma roll or a gravure roll, but the flattening portion may be configured by a material other than such a roll-shaped one. For example, a flattened portion is provided on the lower surface of a rectangular parallelepiped mold similar to the inclined step of the comma roll of the first embodiment. Even in such a flattened portion, the end height portion can be pushed away from one end side in the width direction by the inclined step, and the electrode paste in the pushed end height portion can be brought closer to the other end side in the width direction.

  DESCRIPTION OF SYMBOLS 1, ... Electrode manufacturing apparatus, 10 ... Comma roll (flattening part), 10a ... Peripheral surface, 10b ... Level difference, 10c ... Tip part, 11 ... Backup roll, 12 ... Collection container (collection part), 20 ... Gravure Roll (flattening part), 20a ... peripheral surface, 20b ... groove, 21 ... backup roll, 22 ... transfer roll, 22a ... peripheral surface, 23 ... scraper, 24 ... collection container (collection part).

Claims (6)

An electrode manufacturing apparatus for flattening a protruding portion of an electrode paste applied to a band-shaped metal foil,
A flattening portion disposed on the belt-shaped metal foil transport path, and planarizing by removing the protruding portion of the electrode paste during the transport of the strip-shaped metal foil;
The flattening part has a convex part protruding to the transport path side,
The said convex-shaped part is an electrode manufacturing apparatus extended in the direction inclined with respect to the direction orthogonal to the conveyance direction of the said strip | belt-shaped metal foil.   The electrode manufacturing apparatus according to claim 1, further comprising a recovery unit that recovers the electrode paste of the protruding portion removed by the flattening unit. The flattening portion is a comma roll.
The electrode manufacturing apparatus according to claim 1, wherein the convex portion is a stepped portion of the comma roll. The flattening part is a gravure roll,
The gravure roll has a plurality of the convex portions, and a groove between the convex portions and the convex portions extends in a direction inclined with respect to a direction orthogonal to the transport direction. The electrode manufacturing apparatus according to claim 1 or 2. A method for producing an electrode including a coating step of coating an electrode paste on a strip-shaped metal foil,
Removal of the protruding portion of the electrode paste applied in the coating process by the convex portion inclined with respect to the direction orthogonal to the transport direction of the strip metal foil during the transport of the strip metal foil Process,
A recovery step of recovering the electrode paste of the protruding portion removed in the removal step;
A method for producing an electrode, comprising:   The said coating process is a manufacturing method of the electrode of Claim 5 which applies an electrode paste to the said strip | belt-shaped metal foil intermittently.