Electrode manufacturing equipment

Abstract

To provide an electrode manufacturing device capable of maintaining the uniformity of a groove depth of an electrode.SOLUTION: An electrode manufacturing device includes a molding roll 41 and an opposing roll 42 rotating in the opposite direction to each other with an electrode 100 sandwiched thereby and a temperature adjustment section. The temperature adjustment section decreases a temperature difference between a central part and an end part in the axial direction, of at least either one roll of the molding roll 41 and the opposing roll 42.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present disclosure relates to an electrode manufacturing apparatus. [Background technology]

[0002] Japanese Patent Application Laid-Open No. 2002-015764 (Patent Document 1) describes a battery having positive and negative electrodes with electrode active material layers on both sides of a current collector plate, in which a groove is formed in the electrode active material layer of one of the positive or negative electrodes. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-015764 Summary of the Invention [Problem to be solved by the invention]

[0004] When manufacturing a large-area battery using the device described in the above document, it is difficult to maintain uniformity in the groove depth in the width direction.

[0005] The present disclosure proposes an electrode manufacturing apparatus that is capable of maintaining uniformity in the groove depth of the electrode. [Means for solving the problem]

[0006] According to the present disclosure, there is provided an electrode manufacturing apparatus including a pair of rolls that rotate in opposite directions with an electrode sandwiched therebetween, and a temperature adjustment unit, wherein the temperature adjustment unit reduces the temperature difference between the center and end portions in the axial direction of at least one of the pair of rolls.

[0007] By configuring the temperature adjustment unit to reduce the temperature difference between the center and end of the roll, it is possible to improve the uniformity of thermal expansion between the center and end of the roll, and improve the uniformity of the outer diameter of the roll between the center and end of the roll, thereby maintaining the uniformity of the groove depth of the electrode in the width direction.

[0008] In the electrode manufacturing apparatus, the electrode may have a substrate and an electrode layer formed on the surface of the substrate, and the pair of rolls may have a forming roll that forms an uneven shape on the surface of the electrode layer and an opposing roll that faces the forming roll across the electrode. By adjusting the temperature of at least one of the forming roll and the opposing roll, it is possible to maintain uniformity in the groove depth of the electrode in the width direction.

[0009] In the electrode manufacturing apparatus, the forming roll may form groove-shaped recesses extending in the width direction of the electrode on the surface of the electrode layer. The recesses extending in the width direction of the electrode impart flexibility to the electrode, thereby suppressing cracking of the electrode layer during transport of the electrode.

[0010] In the electrode manufacturing apparatus, the forming roll may form a recess extending across the entire width of the electrode layer. The recess communicates with both edge portions of the electrode layer in the width direction, allowing a liquid to flow through the recess, thereby shortening the penetration time in the subsequent electrolyte injection step.

[0011] In the electrode manufacturing apparatus, the temperature adjusting unit may adjust the temperature of the opposing roll. By adjusting the temperature of the opposing roll, uniformity of the groove depth of the electrode in the width direction can be efficiently maintained.

[0012] In the electrode manufacturing apparatus, the temperature adjusting unit may include a cooling device for cooling the end portion, thereby making it possible to reliably reduce the temperature difference between the center and end portion of the roll.

[0013] In the electrode manufacturing apparatus, the temperature adjusting unit may have a heating device for heating the central portion, thereby reliably reducing the temperature difference between the central portion and the end portions of the roll.

[0014] The electrode manufacturing apparatus may further include a temperature sensor for detecting the temperatures of the center and the end portions of the roll, and the temperature adjustment unit can efficiently reduce the temperature difference between the center and the end portions of the roll based on the temperature difference between the center and the end portions of the roll. [Effects of the Invention]

[0015] According to the electrode manufacturing apparatus of the present disclosure, uniformity of the groove depth of the electrode can be maintained even when manufacturing a large-area battery. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a perspective view showing a schematic configuration of a first example of an electrode in an embodiment. [Figure 2] FIG. 4 is a perspective view showing a schematic configuration of a second example of an electrode in the embodiment. [Figure 3] FIG. 10 is a perspective view showing a schematic configuration of a third example of an electrode in the embodiment. [Figure 4] 1 is a conceptual diagram showing an electrode manufacturing apparatus according to an embodiment. [Figure 5] FIG. 2 is a conceptual diagram showing the details of the configuration of a film forming apparatus. [Figure 6] FIG. 2 is a conceptual perspective view showing the details of the configuration of the film forming apparatus. [Figure 7] FIG. 2 is a schematic diagram showing a first example of a temperature adjusting section. [Figure 8] FIG. 10 is a schematic diagram showing a second example of a temperature adjusting section. [Figure 9] 10 is a graph showing the temperature difference and groove depth difference between the center and end portions of a roll in a comparative example. [Figure 10] 1 is a graph showing the temperature difference and groove depth difference between the center and end portions of a roll in an example. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, an embodiment will be described with reference to the drawings. In the following description, the same components are denoted by the same reference numerals. The names and functions of the components are also the same. Therefore, detailed description thereof will not be repeated.

[0018] <Electrode 100> FIG. 1 is a perspective view showing a schematic configuration of a first example of an electrode 100 according to an embodiment. The electrode 100 is used, for example, as an electrode for a lithium ion secondary battery (nonaqueous electrolyte secondary battery). The lithium ion secondary battery can be used, for example, as a power source for a hybrid vehicle (HV), an electric vehicle (EV), a plug-in hybrid vehicle (PHV), or the like. However, the electrode 100 of the present disclosure is not limited to such in-vehicle applications and can be applied to a variety of applications.

[0019] As shown in FIG. 1 , the electrode 100 has a substrate 110 and an electrode layer 120. The substrate 110 is a support for the electrode layer 120. The substrate 110 may be, for example, sheet-shaped. The substrate 110 may be, for example, strip-shaped. The substrate 110 may be conductive. The substrate 110 may function as a current collector. The substrate 110 may include, for example, a metal foil. When the electrode 100 is a positive electrode, the substrate 110 may include, for example, aluminum foil. When the electrode 100 is a negative electrode, the substrate 110 may include, for example, copper foil.

[0020] The electrode layer 120 is formed on the surface of the substrate 110. The electrode layer 120 may be formed on only one surface of the substrate 110 as shown in FIG. 1, or may be formed on both the front and back surfaces of the substrate 110.

[0021] The electrode layer 120 is an electrode active material layer containing an electrode active material. The electrode active material may be a positive electrode active material or a negative electrode active material. Examples of the positive electrode active material include lithium-containing metal oxides and lithium-containing phosphates. Examples of the negative electrode active material include carbon-based negative electrode active materials such as graphite, graphitizable carbon, and non-graphitizable carbon, and alloy-based negative electrode active materials containing silicon, tin, and the like.

[0022] Recesses 121 (grooves) are formed in the electrode layer 120. At least one recess 121 is formed in the electrode layer 120. The cross-sectional shape of the recess 121 is arbitrary. The bottom of the recess 121 may be flat, curved, or inclined. In cross-sectional view, the recess 121 may be U-shaped or V-shaped. Protrusions 122 are formed between adjacent recesses 121.

[0023] The electrode 100 has a longitudinal direction (Y direction) and a lateral direction (X direction). The longitudinal direction corresponds to the transport direction in the manufacturing process of the electrode 100. The lateral direction is a direction perpendicular to the longitudinal direction, which can also be described as the width direction of the electrode 100. The electrode 100 also has a thickness direction (Z direction). The thickness direction is a direction perpendicular to the XY plane. The recess 121 is formed such that a portion of the electrode layer 120 is recessed from the surface of the electrode layer 120 and extends in the Z direction.

[0024] 1, the recesses 121 and the protrusions 122 extend along the short-side direction. The recesses 121 are formed at equal intervals in the longitudinal direction. Groove-shaped recesses 121 extending in the short-side direction of the electrode 100 are formed in the electrode layer 120, imparting flexibility to the electrode 100. This prevents cracks in the electrode layer 120 when the electrode 100 is transported, improving the transportability of the electrode 100.

[0025] 2 is a perspective view showing a schematic configuration of a second example of the electrode 100 according to the embodiment. In the example shown in FIG. 2, the recesses 121 and the protrusions 122 extend along the longitudinal direction. The recesses 121 are formed at equal intervals in the width direction. The recesses 121 extending along the longitudinal direction of the electrode 100 are formed in the electrode layer 120, thereby reducing the difference in the amount of shrinkage between the substrate 110 and the electrode layer 120 during drying. This suppresses warping of the electrode 100 after drying.

[0026] Fig. 3 is a perspective view showing a schematic configuration of a third example of the electrode 100 according to the embodiment. In the example shown in Fig. 3, the recess 121 extends in the width direction of the electrode 100, similarly to Fig. 1, and extends over the entire length of the electrode layer 120 in the width direction. The formation of the recess 121 that extends continuously from one edge of the electrode layer 120 in the width direction to the other edge imparts flexibility to the electrode 100, and the recess 121 communicates with both edges of the electrode layer 120 in the width direction, allowing liquid to flow through the recess 121, thereby shortening the penetration time in the subsequent electrolyte injection step.

[0027] The electrode 100 may have both recesses 121 and protrusions 122 extending in the longitudinal direction as shown in Fig. 2, and recesses 121 and protrusions 122 extending in the lateral direction as shown in Figs. 1 and 3. The shape of each recess 121 is not limited to the straight line shown in Figs. 1 to 3, but may be curved, wavy, or dotted. The planar pattern of the recesses 121 may be line-like or lattice-like.

[0028] <Electrode manufacturing equipment 1> 4 is a conceptual diagram showing an electrode manufacturing apparatus 1 in an embodiment. As shown in FIG. 4, the electrode manufacturing apparatus 1 includes a conveying device 10, a film forming device 20, a forming device 40, and a drying device 50.

[0029] The conveying device 10 has a feed roll 11 and a take-up roll 12. The feed roll 11 is formed by winding a substrate 110 around a core material. The substrate 110 is unwound from the feed roll 11. The take-up roll 12 takes up the substrate 110 (electrode 100). The conveying device 10 conveys the substrate 110 so that it passes through the film-forming device 20, the molding device 40, and the drying device 50 in this order, and conveys the electrode 100, which is a laminate formed by laminating an electrode layer 120 on the substrate 110.

[0030] The film forming apparatus 20 forms an electrode layer 120 on the surface of the substrate 110. Details of the film forming apparatus 20 will be described later.

[0031] The forming device 40 forms an uneven shape on the surface of the electrode layer 120. The forming device 40 forms recesses 121 and protrusions 122 in the electrode layer 120. The forming device 40 has, for example, a forming roll 41 and an opposing roll 42. The forming roll 41 and the opposing roll 42 constitute a pair of rolls that rotate in opposite directions with the electrode 100 sandwiched between them. The forming roll 41 forms an uneven shape on the surface of the electrode layer 120. The opposing roll 42 faces the forming roll 41 with the electrode 100 sandwiched between them.

[0032] One or more convex portions are formed on the outer peripheral surface of the forming roll 41. In the forming device 40, the electrode 100 conveyed in the longitudinal direction (Y direction) by the conveying device 10 is sandwiched between the forming roll 41 and the opposing roll 42, and at this time, the convex portions of the forming roll 41 are pressed against the surface of the electrode layer 120, thereby forming concave portions 121 and convex portions 122 on the surface of the electrode layer 120. The forming device 40 is disposed upstream of the drying device 50 in the conveying direction of the electrode 100, and is configured to process the surface of the electrode layer 120 in a wet state before drying. This makes it easy to form the concave and convex shapes.

[0033] When the electrode layer 120 is formed with both a concave-convex shape extending in the longitudinal direction and a concave-convex shape extending in the lateral direction of the electrode 100, the forming device 40 may have one forming roll that forms both the concave-convex shape extending in the longitudinal direction and the concave-convex shape extending in the lateral direction of the electrode 100. Alternatively, the forming device 40 may have separate forming rolls that form the concave-convex shape extending in the longitudinal direction of the electrode 100 and the concave-convex shape extending in the lateral direction of the electrode 100.

[0034] The drying device 50 dries the electrode layer 120 after the concave-convex shape has been formed. The drying device 50 can dry the electrode layer 120 by any method. The drying device 50 may include, for example, a hot air drying device, an infrared drying device, or the like. The drying conditions (drying temperature, drying time, etc.) in the drying device 50 are adjusted so that the electrode layer 120 is in a dry state.

[0035] After the electrode layer 120 has been dried, the electrode 100 is cut to a predetermined size using, for example, a slitter, thereby producing a sheet-like electrode 100 as shown in FIGS. 1 to 3.

[0036] <Film forming equipment 20> In the film forming apparatus 20, an electrode material is supplied between a pair of rolls that are arranged parallel to each other with a gap between them and are each driven to rotate, and the electrode material is compression molded by the pair of rolls to form a sheet-like coating film.

[0037] Fig. 5 is a conceptual diagram showing the detailed configuration of the film formation apparatus 20. Fig. 6 is a conceptual perspective view showing the detailed configuration of the film formation apparatus 20. As shown in Figs. 5 and 6, the film formation apparatus 20 has a first roll 21, a second roll 22, and a third roll 23. The first roll 21, the second roll 22, and the third roll 23 have a roughly cylindrical shape with approximately the same diameter.

[0038] The first roll 21, the second roll 22, and the third roll 23 are each driven to rotate. In Figures 5 and 6, the curved arrows drawn on each roll indicate the rotation direction of each roll. The second roll 22 rotates in the opposite direction to the first roll 21. The third roll 23 rotates in the opposite direction to the second roll 22. In Figures 5 and 6, the first roll 21 rotates in the clockwise direction, the second roll 22 rotates in the counterclockwise direction, and the third roll 23 rotates in the clockwise direction.

[0039] The second roll 22 is disposed parallel to and spaced apart from the first roll 21. The outer circumferential surface of the first roll 21 and the outer circumferential surface of the second roll 22 face each other via a first gap, which is the gap between the first roll 21 and the second roll 22. The shafts of the first roll 21 and the second roll 22 are fixed so that the distance between them is maintained constant.

[0040] The third roll 23 is disposed parallel to and spaced apart from the second roll 22. The outer circumferential surface of the second roll 22 and the outer circumferential surface of the third roll 23 face each other via a second gap, which is the gap between the second roll 22 and the third roll 23. The shaft of the third roll 23 is fixed so that the distance between it and the second roll 22 is maintained constant.

[0041] The feeder 25 is disposed between the pair of rolls, specifically directly above the first gap between the first roll 21 and the second roll 22. The feeder 25 supplies the electrode material 91 to the first gap between the first roll 21 and the second roll 22. The electrode material 91 is, for example, a powder.

[0042] 6, the film forming apparatus 20 further includes a pair of partition walls 24. The pair of partition walls 24 are arranged parallel to each other at a predetermined interval in the axial direction of each roll. The pair of partition walls 24 regulates the width dimension of the electrode material 91 supplied to the gap between the first roll 21 and the second roll 22.

[0043] As the first roll 21 and the second roll 22 rotate, the electrode material 91 passes through a first gap between the first roll 21 and the second roll 22 and is drawn below the first gap. When the electrode material 91 passes through the first gap between the first roll 21 and the second roll 22, it is consolidated (compressed) and formed into a sheet. As a result, a thin film coating film 92 is formed from the electrode material 91. By changing the dimension of the first gap between the first roll 21 and the second roll 22, the thickness of the coating film 92 and the mass per unit area of ​​the coating film 92 can be adjusted.

[0044] After passing through the first gap between the first roll 21 and the second roll 22, the coating film 92 is transported while adhering to the second roll 22 and supplied to the second gap between the second roll 22 and the third roll 23.

[0045] The substrate 110 is fed from the feed roll 11 (FIG. 4) and then transported to the third roll 23. The substrate 110 is transported on the third roll 23 and supplied to the second gap between the second roll 22 and the third roll 23.

[0046] The coating film 92 and the substrate 110 are supplied between the second roll 22 and the third roll 23. In the second gap, the coating film 92 is pressed against the substrate 110, and then the coating film 92 is separated from the second roll 22 and pressure-bonded to the surface of the substrate 110. That is, the coating film 92 is transferred from the second roll 22 to the substrate 110. In this manner, an electrode 100 is formed in which a sheet-like electrode layer 120 is laminated at a predetermined position on the surface of the substrate 110. The second roll 22 and the third roll 23 constitute a pair of rolls that rotate in opposite directions with the electrode 100 sandwiched between them.

[0047] Since the film forming apparatus 20 has a pair of partition walls 24 and restricts the width dimension of the electrode layer 120, exposed portions (see FIGS. 1 to 3) where the electrode layer 120 is not formed are provided on both sides of the electrode 100 in the width direction (X direction) of the electrode 100. A recess 121 shown in FIG. 3 connects the exposed portions on both sides of the electrode layer 120 to each other.

[0048] 5 and 6 show an example in which the first roll 21, the second roll 22, and the third roll 23 are arranged side by side, and the rotation axes of the first roll 21, the second roll 22, and the third roll 23 are on the same plane. The first roll 21, the second roll 22, and the third roll 23 are not limited to the example shown in Figures 5 and 6, and may be arranged in any other manner. For example, the third roll 23 may be arranged directly below the second roll 22 with a gap therebetween.

[0049] <Temperature adjustment part> The electrode manufacturing apparatus 1 of the embodiment further includes a temperature adjustment unit. The temperature adjustment unit has a function of reducing the temperature difference between the center and end portions in the axial direction of at least one of a pair of rolls (i.e., the forming roll 41 and the opposing roll 42) that rotate in opposite directions with the electrode 100 sandwiched therebetween in the forming apparatus 40.

[0050] Fig. 7 is a schematic diagram showing a first example of a temperature adjustment unit. The temperature adjustment unit shown in Fig. 7 adjusts the temperature of the forming roll 41 and adjusts the temperature of the opposing roll 42. More specifically, the temperature adjustment unit has a cooling device 60. The cooling device 60 cools both ends of the forming roll 41. The cooling device 60 cools both ends of the opposing roll 42.

[0051] The cooling device 60 is realized, for example, by a cooling medium flow path formed in a housing that supports the end of the roll. The cooling medium is, for example, water. The housing rotatably supports the end of the roll via bearings. A cooling medium flow path is formed around the bearing, and the cooling medium circulates through this flow path. The cooling medium, whose temperature has increased due to heat transfer from the end of the roll, is cooled at a position away from the end of the roll and returns to the end of the roll. The cooling device 60 is not limited to this example, and may cool the end of the roll by any means, such as a Peltier element or a heat pipe.

[0052] Fig. 8 is a schematic diagram showing a second example of the temperature adjustment unit. The temperature adjustment unit shown in Fig. 8 adjusts the temperature of the forming roll 41 and adjusts the temperature of the opposing roll 42. More specifically, the temperature adjustment unit has a heating device 70. The heating device 70 heats the center of the forming roll 41. The heating device 70 heats the center of the opposing roll 42.

[0053] The heating device 70 is realized by, for example, an electric heater. The heating device 70 may have multiple heaters arranged in the axial direction of the roll. Which of the multiple heaters generates heat and the amount of heat generated by the heater may be controlled according to the temperature distribution of the roll in the axial direction.

[0054] As shown in FIGS. 7 and 8 , the film forming apparatus 20 further includes a temperature sensor 80. The temperature sensor 80 may be a non-contact sensor such as an infrared sensor. A temperature sensor 80 that detects the temperature of the center of the roll and a temperature sensor 80 that detects the temperature of the end of the roll may be provided. The temperature sensor 80 that scans in the axial direction of the roll may detect the temperatures of the center and end of the roll. The temperature difference between the center and end of the roll is determined based on the detection result of the temperature sensor 80. By feedback-controlling the temperature adjustment unit based on the temperature difference between the center and end of the roll, the temperature adjustment unit can efficiently reduce the temperature difference between the center and end of the roll.

[0055] <Action and effect> The characteristic configurations and effects of the above-described embodiment will be summarized as follows.

[0056] As shown in Fig. 4, the electrode manufacturing apparatus 1 includes a forming device 40. The forming device 40 includes a forming roll 41 that forms an uneven shape on the surface of the electrode layer 120, and an opposing roll 42 that faces the forming roll 41 with the electrode 100 sandwiched between them. The forming roll 41 and the opposing roll 42 rotate in opposite directions with the electrode 100 sandwiched between them. As shown in Figs. 7 and 8, the electrode manufacturing apparatus 1 includes a temperature adjustment unit that reduces the temperature difference between the center and end portions in the axial direction of at least one of the forming roll 41 and the opposing roll 42.

[0057] The ends of the roll are supported by a housing. Frictional heat is generated when the roll rotates relative to the housing. As the frictional heat is transferred to the roll, the ends of the roll are more likely to heat up than the center of the roll. When manufacturing a wide electrode 100, the temperature difference between the center and ends of the roll becomes significant, and this temperature difference can cause the ends of the roll to expand more thermally than the center of the roll. The ends of the roll have a larger diameter than the center, widening the gap between the pair of opposing rolls at the center of the roll. Weaker groove-forming pressure at the center of the roll reduces the depth of the recesses 121 (grooves) formed in the electrode layer 120, potentially making it impossible to maintain uniformity in the groove depth of the electrode layer 120 between the center and ends of the electrode 100 in the width direction.

[0058] In the electrode manufacturing apparatus 1 of the embodiment, the forming device 40 has a temperature adjustment unit, and is configured to reduce the temperature difference between the center and end of the roll. This improves the uniformity of thermal expansion between the center and end of the roll, and improves the uniformity of the outer diameter of the roll between the center and end of the roll. Therefore, the electrode manufacturing apparatus 1 of the embodiment can maintain uniformity of the groove depth of the electrode layer 120 in the width direction, even when manufacturing a wide electrode 100.

[0059] 1 and 3, the forming roll 41 may form groove-shaped recesses 121 extending in the width direction of the electrode 100 on the surface of the electrode layer 120. If the electrode layer 120 has a thickness equal to or greater than a certain level, cracks may occur in the electrode layer 120 when the electrode 100 passes over a roll with a large embrace angle during transport. By forming the recesses 121 extending in the short direction of the electrode 100 in the electrode layer 120 and imparting flexibility to the electrode 100, cracks in the electrode layer 120 during transport can be suppressed, and the transportability of the electrode 100 can be improved.

[0060] 3, the forming roll 41 may form recesses 121 extending across the entire width of the electrode layer 120. The recesses 121 communicate with both edge portions of the electrode layer 120 in the width direction, and the recesses 121 communicate with exposed portions on both sides of the electrode layer 120 in the width direction. Because liquid can flow through the recesses 121, the permeation time in the subsequent electrolyte injection step can be shortened. This can improve the productivity of batteries using the electrode 100.

[0061] 7 and 8, the temperature adjusting unit may adjust the temperature of the opposing roll 42. The load on the forming roll 41 may vary depending on the relationship between the convex shape of the forming roll 41 and the depth of the recesses 121 formed in the electrode layer 120. On the other hand, the load on the opposing roll 42 is kept relatively constant, regardless of the relationship between the convex shape of the forming roll 41 and the depth of the recesses 121 formed in the electrode layer 120. Therefore, by adjusting the temperature of the opposing roll 42 and improving the uniformity of the outer diameter at the center and ends of the opposing roll 42, the uniformity of the groove depth in the electrode layer 120 can be efficiently maintained.

[0062] As shown in FIGS. 7 and 8, by providing temperature adjustment units to both the forming roll 41 and the opposing roll 42 that make up the forming device 40, the uniformity of the groove depth of the electrode layer 120 can be further improved.

[0063] As shown in FIG. 7 , the temperature adjustment unit may include a cooling device 60 that cools the ends of the roll. Cooling the ends of the roll using the cooling device 60 reliably reduces the temperature difference between the center and ends of the roll. The forming device 40 is located upstream of the drying device 50 that dries the electrode layer 120 in the conveying direction of the electrode 100, and the electrode layer 120 is in a wet state before drying when it passes through the forming device 40. Heating the roll can accelerate evaporation of water from the electrode layer 120, reducing the water content of the electrode layer 120 and making it difficult to handle. Adjusting the temperature of the roll by cooling the ends of the roll can suppress evaporation of water from the electrode layer 120, thereby suppressing changes in the properties of the electrode 100 that occur due to changes in the water content.

[0064] As shown in FIG. 8, the temperature adjustment unit may have a heating device 70 that heats the center of the roll. By using the heating device 70 to heat the center of the roll, the temperature difference between the center and ends of the roll can be reliably reduced. By controlling the amount of heat applied by the heating device 70, the temperature difference between the center and ends of the roll can be precisely reduced. By configuring the heating device 70 to have multiple heaters arranged in the axial direction of the roll and controlling the multiple heaters according to the temperature distribution in the axial direction of the roll, the temperature difference between the center and ends of the roll can be further reduced.

[0065] 7 and 8, the film forming apparatus 20 may have a temperature sensor 80 that detects the temperatures of the center and end portions of the roll. By feedback-controlling the temperature adjustment unit based on the temperature difference between the center and end portions of the roll, the temperature adjustment unit can efficiently reduce the temperature difference between the center and end portions of the roll.

[0066] In the explanation of the embodiments so far, an example in which the temperature adjustment unit has a cooling device 60 is shown in Fig. 7, and an example in which the temperature adjustment unit has a heating device 70 is shown in Fig. 8. The temperature adjustment unit may have both the cooling device 60 and the heating device 70.

[0067] 7 and 8 show an example in which the forming device 40 has a temperature sensor 80, but the temperature sensor 80 is not necessarily provided. For example, it is possible to verify in advance how the temperature of the roll varies in accordance with the groove processing conditions, and then control the temperature adjustment unit in accordance with a program created based on the verification results to reduce the temperature difference between the center and end portions of the roll, thereby achieving the same effects as those of the above-described embodiment. [Example]

[0068] Examples will be described below. Using the molding device 40 provided with a temperature adjustment unit as described in the embodiment, recesses 121 were formed on the surface of the electrode layer. The roll temperature during groove processing and the difference in groove depth between the center and end of the roll were measured. As a comparative example, molding was similarly performed using a film forming device not provided with a temperature adjustment unit, and the difference in roll temperature during groove processing and the difference in groove depth were measured.

[0069] 9 is a graph showing the temperature difference and groove depth difference between the center and end of the roll in the comparative example. In the comparative example, a temperature difference occurred between the center and end of the roll 10 minutes after the start of groove processing. Thermal expansion caused the outer diameter of the end of the roll to become larger than the outer diameter of the center of the roll, resulting in a difference in groove depth between the center and end exceeding 3 μm, making it impossible to maintain uniformity in the groove depth of the electrode 100.

[0070] FIG. 10 is a graph showing the temperature difference and groove depth difference between the center and end of the roll in the example. In the example, the temperature difference between the center and end of the roll during heating was smaller than in the comparative example. The difference in outer diameter between the center and end of the roll was reduced, and as a result, the groove depth difference between the center and end was maintained at a maximum of approximately 1 μm. Therefore, it was revealed that the uniformity of the groove depth of the electrode 100 can be maintained by reducing the temperature difference between the center and end of the roll.

[0071] The embodiments disclosed herein are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include meanings equivalent to the claims and all modifications within the scope thereof. [Explanation of symbols]

[0072] 1 electrode manufacturing apparatus, 10 conveying device, 11 delivery roll, 12 winding roll, 20 film forming device, 21 first roll, 22 second roll, 23 third roll, 24 partition wall, 25 feeder, 40 forming device, 41 forming roll, 42 opposing roll, 50 drying device, 60 cooling device, 70 heating device, 80 temperature sensor, 91 electrode material, 92 coating film, 100 electrode, 110 substrate, 120 electrode layer, 121 recess, 122 protrusion.

Claims

1. a film forming device for forming an electrode layer on a surface of a substrate; a molding device, the forming device includes a forming roll that forms an uneven shape on the surface of the electrode layer, and an opposing roll that faces the forming roll with an electrode that is a laminate obtained by laminating the electrode layer on the base material sandwiched therebetween, the forming roll and the opposing roll rotating in opposite directions to each other, the forming roll forms groove-shaped recesses extending in the width direction of the electrode on the surface of the electrode layer, The electrode manufacturing apparatus further comprises a temperature adjusting unit that reduces the temperature difference between a central portion and an end portion in the axial direction of at least one of the forming roll and the opposing roll.

2. The electrode manufacturing apparatus according to claim 1 , wherein the forming roll forms the recesses extending over the entire length of the electrode layer in the width direction.

3. The electrode manufacturing apparatus according to claim 1 , wherein the temperature adjusting unit adjusts the temperature of the opposing roll.

4. The electrode manufacturing apparatus according to claim 1 , wherein the temperature adjusting unit has a cooling device that cools the end portion.

5. The electrode manufacturing apparatus according to claim 1 , wherein the temperature adjusting section has a heating device that heats the central portion.

6. The electrode manufacturing apparatus according to claim 1 , further comprising temperature sensors that detect temperatures of the central portion and the end portions.

7. the cooling device cools both of the ends; 6. The electrode manufacturing apparatus according to claim 5, wherein the heating device has a plurality of heaters arranged in the axial direction, and the plurality of heaters are controlled in accordance with a temperature distribution in the axial direction.

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