Groove-forming mechanism for manufacturing raw materials for secondary batteries

Abstract

The present invention provides a groove-forming mechanism for a secondary battery raw material manufacturing apparatus that can form neat grooves of uniform depth on the surface of the active material layer during high-speed transport. [Solution] The groove forming mechanism 40 of the manufacturing apparatus A for secondary battery raw material 10 includes the steps of forming an active material layer 3 on one surface of a current collector 1, forming grooves 3m on the surface of the active material layer 3 which has become a semi-dried clay state, and drying the active material layer 3 on which the grooves 3m have been formed. The groove forming mechanism 40 consists of a molding roller 41 for forming grooves 3m, a molding backup roller 45, and a molding roller vibration generating unit 46 that applies vibration to the molding roller 41. The molding roller 41 consists of a rotating shaft 42 and disc-shaped flanges 43 arranged in multiple rows on the rotating shaft 42 and formed to have a larger diameter than the rotating shaft 42. The gap S43 between the tip of the disc-shaped flange 43 on the active material layer 3 side and the active material coated surface of the current collector 1 is set to be smaller than the thickness T3 of the active material layer 3.

Description

[Technical Field]

[0001] The present invention relates to a concave groove forming mechanism that continuously forms concave grooves with an accurate depth in a semi-dried active material layer, in a manufacturing apparatus for manufacturing a raw fabric for large-capacity secondary batteries (including lithium ion capacitors), where the apparatus uses a long and wide metal foil, applies a thick coating of active material onto a current collector that is conveyed in one direction, and dries the thickly coated active material layer to obtain the raw fabric. [Background Art]

[0002] At present, as environmental protection measures, secondary batteries such as large-capacity lithium-ion batteries, which serve as power supplies for power engines and electronic devices, starting with electric vehicles, have attracted enormous attention. Taking a lithium-ion battery as an example, for the positive / negative electrodes, a raw fabric for secondary batteries is used: a positive / negative active material mixture (coating liquid) is thickly applied, for example to 140 μm, onto a strip-shaped current collector (metal foil), which is then dried and cured, and further compressed to about 100 μm by a roll press to increase the density of the active material layer. Then, the current collector with the active material applied thereon is cut into a predetermined width to obtain a narrow-width current collector, or processed into a rectangular sheet.

[0003] The narrow-width current collector is wound into a cylindrical shape with a separator interposed therebetween to form an electrode assembly, which is then housed in a cylindrical battery can, or the cylindrical electrode assembly is further formed into a flat shape and housed in a prismatic battery can, and electrolyte is injected to obtain a secondary battery. For a rectangular sheet, a plurality of these positive / negative electrodes are stacked with separators interposed therebetween, housed in a bag, and electrolyte is injected in the same manner to obtain a secondary battery.

[0004] The active material layers of the positive / negative electrodes are formed by applying the coating liquid (active material mixture) extruded from a die of a coating apparatus in a rectangular shape at regular intervals on one or both sides of a long and wide current collector (metal foil), or formed by continuous coating. The coating liquid is a viscous material in the form of aqueous or solvent-based slurry or paste.

[0005] After coating, the active material layer is sent to a drying oven in a clay-like, semi-dry state, where most of the solvent or moisture is removed by volatilization or evaporation. Subsequently, roll pressing is performed to increase the density of the hardened active material layer. Further drying is performed to remove any remaining solvent or moisture from the active material layer, thereby forming a hard active material layer on the metal foil (one or both sides), which becomes the electrode material for the secondary battery.

[0006] Patent Document 1 is cited as an example of the above-mentioned drying oven. The drying oven described in Patent Document 1 comprises a furnace body through which a strip-shaped current collector conveyed in the horizontal direction passes, and a blowing unit that blows air into the furnace body to dry the active material layer. The furnace body has a heat treatment zone consisting of a preheating zone for preheating the current collector (raw material) coated with the active material, a heating zone for heating the raw material at a temperature higher than the temperature preheated in the preheating zone, and a slow cooling zone for heating at a temperature lower than the temperature heated in the heating zone. In such drying ovens, where the raw material is transported horizontally, if the active material layers on the positive and negative electrodes are thickly applied, drying takes a long time, requiring the oven to be very long, for example, 100 meters. This long drying oven requires a vast installation area.

[0007] In contrast, Patent Document 2 describes a technology that uses a roll press having multiple rows of disc-shaped flanges to form multiple rows of grooves on the surface of the active material layer on a current collector being conveyed in one direction. This allows for rapid evaporation of the solvent in the adhesive layer of the active material layer during the drying process, thereby shortening the drying time and reducing the length of the long drying oven. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Application Publication No. 10-228898 [Patent Document 2] International Publication No. WO98 / 48466 [Overview of the project] [Problems that the invention aims to solve]

[0009] In Patent Document 2, a thick layer of active material is applied to a current collector, and in a semi-dry state, a roll press with a disc-shaped flange is pressed against this clay-like active material layer to form multiple rows of grooves on its surface. At the same time, the shaft portion of the roll press is pressed against the surface of the active material layer, pushing the active material on the surface that comes into contact with the shaft portion backward, thereby forming the grooves and simultaneously defining the thickness of the active material layer after the roll press to be equal to the height of the shaft portion of the roll press. However, as described above, if one roll press attempts to simultaneously create a groove and set the thickness of the active material layer to a predetermined thickness, this may be possible at slow current collector speeds. However, at high speeds such as 100 m / min, the resistance applied to the roll press becomes excessive, and this resistance, combined with other factors, causes minute vibrations in the current collector perpendicular to the transport direction (vertical direction in the case of horizontal transport).

[0010] Because the thickness of the applied active material layer is very thin, at 140 μm, it is impossible to form grooves of precise depth unless minute vertical vibrations during transport are suppressed. If the groove depths are uneven, it will cause problems in the drying process described above, and at the same time, the uniformity of the density of the active material layer will be lost, leading to a decrease in capacity, a shortened cycle life, an increase in heat generation due to increased internal resistance, resulting in localized overheating, reduced safety, unstable charge / discharge characteristics, and a decline in quality. Furthermore, as described above, the resistance force applied to the roll press becomes excessive. As the disc-shaped flange and shaft separate from the active material layer on the current collector, which is being transported at high speed in one direction, the contacting active material adheres to and peels off the surface of the disc-shaped flange and shaft of the roll press. This results in a rough surface, making it impossible to obtain clean grooves or a flat surface.

[0011] The present invention was made to solve these problems, and its objective is to provide a groove-forming mechanism for a secondary battery raw material manufacturing apparatus that can form neat grooves of uniform depth on the surface of the active material layer during high-speed transport. [Means for solving the problem]

[0012] The invention described in claim 1 (Figures 1 to 4) is a case in which a groove 3m is formed in the active material layer 3 formed on one side of the current collector 1. In a groove-forming mechanism 40 of a secondary battery raw material 10 manufacturing apparatus A, the process includes forming an active material layer 3 on one surface of a long, strip-shaped current collector 1 that is conveyed in one direction, forming grooves 3m on the surface of the semi-dried, clay-like active material layer 3, and drying the active material layer 3 on which the grooves 3m have been formed, The groove-forming mechanism 40 that forms grooves 3m on the surface of the active material layer 3 is A molding roller 41 positioned on the active material layer 3 side, A molding backup roller 45 is positioned opposite the molding roller 41 on the opposite side of the active material layer 3, with the current collector 1 in between, and rotates while in contact with the other side of the current collector 1. It consists of a molding roller vibration generating unit 46 connected to the molding roller 41 and which applies vibration to the molding roller 41, The molding roller 41 is Rotating shaft 42 and The current collector 1 is characterized by comprising a disc-shaped flange 43 arranged in multiple rows on the rotating shaft 42 and having a larger diameter than the rotating shaft 42, and by being set such that the gap S43 between the tip of the disc-shaped flange 43 on the active material layer 3 side and the active material coated surface of the current collector 1 is smaller than the thickness T3 of the active material layer 3 before the formation of the groove 3m.

[0013] The invention described in claim 2 relates to a vibration-preventing structure for the current collector 1 in the groove-forming mechanism 40 (Figure 4), and in the groove-forming mechanism 40 of the manufacturing apparatus A for secondary battery raw material 10 described in claim 1, The device is characterized in that clamping rolls 41k and 45k are provided on the forming roller 41 and the forming backup roller 45, respectively, at positions that coincide with the ear portion 1b where the active material layer 3 is not coated, and which clamp the ear portion 1b.

[0014] The invention described in claim 3 (Figures 8 and 9) is a case in which first and second active material layers 3 and 3 are formed on both sides of the current collector 1, and first and second grooves 3m and 3m are formed in the first and second active material layers 3 and 3, respectively. In a groove forming mechanism 40-40 of a secondary battery raw material A manufacturing apparatus, the process includes forming first and second active material layers 3-3 on both sides of a long, strip-shaped current collector 1 that is conveyed in one direction, forming first and second grooves 3m-3m on the surface of the first and second active material layers 3-3 which have become clay-like in a semi-dried state, and drying the first and second active material layers 3-3 on which the first and second grooves 3m-3m have been formed, The first and second groove forming mechanisms 40, 40, which form first and second grooves 3m, 3m in the first and second active material layers 3, 3 respectively, The first and second molding rollers 41, 41 are respectively positioned on the first and second active material layers 3, 3 sides, It consists of first and second molding roller vibration generating units 46, 46 which are connected to the first and second molding rollers 41, 41 respectively and which apply vibration to the first and second molding rollers 41, 41, The first and second molding rollers 41, 41 are The first and second rotating shafts 42, 42, It is composed of first and second disc-shaped flanges 43, 43 which are arranged in multiple rows on the first and second rotating shafts 42, 42 and face each other at mutually coincidental positions, and which have a larger diameter than the first and second rotating shafts 42, 42, The gap S43-S43 between the tip of the first and second disc-shaped flanges 43-43 on the active material layer 3-3 side and the current collector 1 is set to be smaller than the thickness T3-T3 of the first and second active material layers 3-3 before the formation of the grooves 3m-3m.

[0015] The invention described in claim 4 relates to a vibration-preventing structure for the current collector 1 in the first and second groove-forming mechanisms 40 and 40 (Figure 10), in the groove-forming mechanisms 40 and 40 of the manufacturing apparatus A for secondary battery raw material 10 described in claim 3, The invention is characterized in that clamping roll portions 41k, 41k that clamp the tab 1b are respectively provided on the first and second forming rollers 41, 41 at a position provided between the side edges 3a, 3a of the active material layers 3, 3 and the side edge 1a of the current collector 1 and matching the tab 1b on which the active material layers 3, 3 are not coated.

[0016] The invention according to claim 5 relates to a forming roller vibration generating portion 46 (46, 46) in a groove forming mechanism 40 (40, 40), and is characterized in that, in the groove forming mechanism 40 (40, 40) of the apparatus A for manufacturing a raw fabric 10 for a secondary battery according to claim 1 or 3, the vibration generating source of the forming roller vibration generating portion 46 (46, 46) is an ultrasonic generator.

[0017] Claim 6 relates to the material of the disc-shaped flange 43, and in the groove forming mechanism 40 (40, 40) of the apparatus A for manufacturing a raw fabric 10 for a secondary battery according to claim 1 or 3, the disc-shaped flanges 43 (43, 43) are formed of one non-conductive material selected from ceramics, engineering resins (for example, Delrin), wood materials or rubbers.

[0018] Claim 7 relates to a leveling roller 51 (51, 51) installed downstream of the forming roller 41 (41, 41) (Fig. 5, Fig. 11), and in the groove forming mechanism 40 (40, 40) of the apparatus A for manufacturing a raw fabric 10 for a secondary battery according to claim 1 or 3, a leveling roller 51 (51, 51) is further installed downstream of the groove forming mechanism 40 (40, 40), a gap S51 (S51, S51) between the tip on the active material layer 3 (3, 3) side of the leveling roll portion 51n (51n, 51n) of the leveling roller 51 (51, 51) that contacts the active material layer 3 (3, 3) formed with the groove 3m (3m, 3m) and the surface of the current collector 1 is set to be smaller than the thickness Tm (Tm, Tm) of the active material layer 3 (3, 3) formed with the groove 3m (3m, 3m).

[0019] Claim 8 relates to the material of the leveling roll portion 51n (51n-51n) of the leveling roller 51 (51-51) (Figures 5 and 11), and in the groove forming mechanism 40 (40-40) of the manufacturing apparatus A for secondary battery raw material 10 described in Claim 7, The leveling roll section 51n (51n·51n) is characterized by being formed from one non-conductive material selected from ceramics, engineering resin (e.g., Delrin®), wood, or rubber.

[0020] Claim 9 relates to the groove forming drive unit 47(47-47) of the groove forming mechanism 40(40-40), and in the groove forming mechanism 40(40-40) of the manufacturing apparatus A for secondary battery raw material 10 described in Claim 1 or 3, The molding roller 41 (41-41) is connected to a groove molding drive motor 47m (47m-47m) which is synchronized with the transport speed of the current collector 1.

[0021] Claim 10 relates to the leveling roller drive unit 57 (57-57) of the leveling roller 51 (51-51), and in the groove forming mechanism 40 (40-40) of the manufacturing apparatus A for secondary battery raw material 10 described in Claim 7, The leveling roller 51 (51-51) is connected to a leveling roller drive motor 57m (57m-57m) which is synchronized with the transport speed of the current collector 1. [Effects of the Invention]

[0022] According to the present invention (Claim 1), a groove 3m extending in the transport direction of the active material layer 3 is formed on the surface of the semi-dried active material layer 3 by the groove forming mechanism 40. Therefore, when the drying process begins, the solvent and moisture in the active material layer 3 evaporate not only from the surface of the active material layer 3 but also from the inner surface of the groove 3m, shortening the drying time of the active material layer 3 and consequently shortening the drying distance, i.e., the total length of the drying oven 60. Furthermore, since vibration can be applied to the molding roller 41 when the groove 3m is formed, adhesion of the active material to the disc-shaped flange 43 is suppressed.

[0023] According to the invention described in claim 2, the forming roller 41 and the forming backup roller 45 are each provided with clamping roll portions 41k and 45k that clamp the ear portion 1b, so that in the groove forming mechanism 40, minute vertical vibrations during high-speed transport of the current collector 1 are suppressed. As a result, the surface position of the current collector 1 during transport is fixed to a constant position (gap S43) relative to the insertion tip of the disc-shaped flange 43 into the active material layer 3, and a groove 3m is formed to an accurate depth.

[0024] According to the invention described in claim 3, since the first and second forming rollers 41 and 41 are symmetrically arranged on both sides of the current collector 1, which has active material layers 3 and 3 coated on both sides, grooves 3m and 3m are symmetrically formed in the active material layers 3 and 3m formed on both sides of the current collector 1 as it passes between the first and second forming rollers 41 and 41, and the drying of the active material layers 3 and 3m can be accelerated, similar to claim 1. Furthermore, since the first and second disc-shaped flanges 43 and 43 are formed at positions that coincide with each other, the first and second disc-shaped flanges 43 and 43 back up each other, and the grooves 3m and 3m are formed neatly and symmetrically (Figure 10). As a result, there is no variation in the density of the active material layers 3 and 3m on the front and back sides. In addition, since vibration can be applied to the first and second forming rollers 41 and 41 when forming the grooves 3m and 3m, adhesion of the active material is suppressed, similar to claim 1.

[0025] According to the invention described in claim 4, the presence of the first and second clamping roll portions 41K, 41K suppresses vibration during high-speed transport of the current collector 1 in the groove forming mechanism 40, similar to claim 2.

[0026] According to the invention described in claim 5, since the molding roller vibration generating unit 46 (46-46) is an ultrasonic generator, when the disc-shaped flange 43 (43-43) forms grooves 3m (3m-3m) in the active material layer 3 (3-3), the active material is shaken off and does not adhere to the disc-shaped flange 43 (43-43), making it possible to form clean grooves 3m (3m-3m).

[0027] According to the invention described in claim 6, since a non-conductive material is used as the material for the disc-shaped flange 43 (43-43), there is no risk of metal components migrating to the active material layer 3 (3-3) as contamination during groove formation.

[0028] According to the invention described in claim 7, after groove formation, the surface of the active material layer 3(3·3) that has risen due to the formation of the groove 3m(3m·3m) can be flattened by the leveling roller 51(51·51), thus enabling the formation of a clean groove 3m(3m·3m). Because the groove formation and leveling processes are separated into two steps, excessive pressure is not applied to the molding roller 41(41·41), leveling roller 51(51·51), or the active material layer 3(3·3) during high-speed conveyance of the raw material, enabling the formation of a clean groove 3m(3m·3m).

[0029] According to the invention described in claim 8, since a non-conductive material is used as the material for the leveling roll portion 51n (51n-51n) of the leveling roller 51 (51-51), similar to claim 6, metal components do not migrate to the active material layer 3 (3-3) as contamination during leveling.

[0030] According to the invention described in claims 9 and 10, since synchronized drive motors 47m and 57m (47m, 57m, 47m, and 57m) are used, the contact portions of the molding rollers 41 (41, 41) and leveling rollers 51 (51, 51) with respect to the active material layer 3 (3, 3) rotate without shifting, thereby suppressing adhesion of the active material. [Brief explanation of the drawing]

[0031] [Figure 1] This is a schematic diagram of Embodiment 1 of the present invention and a partially enlarged view of its groove-forming mechanism. [Figure 2] Figure 1 is a perspective view of the groove formation mechanism. [Figure 3] This is a cross-sectional view of Figure 2. [Figure 4] Figure 3 is a partially enlarged cross-sectional view showing the groove formation state. [Figure 5]This is an enlarged partial cross-sectional view of the planarization of the active material layer by a leveling roller according to Embodiment 1 of the present invention. [Figure 6] (a) Enlarged perspective view of a partial cross-section of a groove in the active material layer, (b) Enlarged perspective view of a partial cross-section of another groove, and (c) Enlarged perspective view of a partial cross-section of the flattened active material layer. [Figure 7] This is a partial cross-sectional view of an example in Embodiment 1 where the groove forming mechanism is provided in the front half of the drying oven. [Figure 8] This is a schematic diagram of Embodiment 2 of the present invention. [Figure 9] This is a modified version of Figure 8. [Figure 10] This is a partial cross-sectional view showing the groove formation state in Embodiment 2 of the present invention. [Figure 11] This is an enlarged partial cross-sectional view of the planarization of the active material layer by the leveling roller in Embodiment 2. [Figure 12] This is a perspective view of an example in which the groove-forming roller of the groove-forming mechanism of the present invention is divided into multiple parts. [Modes for carrying out the invention]

[0032] The present invention will now be described in detail with reference to the drawings. Figure 1 is Embodiment 1 according to the present invention, Figure 7 is a modified example thereof, Figures 8 and 9 are schematic diagrams of Embodiment 2, and Figure 12 is an example in which the groove forming roller of the groove forming mechanism is divided into multiple parts. Both Embodiment 1 and Embodiment 2 are roll-to-roll raw material manufacturing apparatus A that applies a coating liquid 2 to one or both sides of a wide, long current collector 1 fed in one direction, dries it, and manufactures raw material 10 for high-capacity secondary batteries. Embodiment 2 will mainly describe the parts that differ from Embodiment 1, and the overlapping parts will refer to the description of Embodiment 1.

[0033] (Embodiment 1) The apparatus A of Embodiment 1 is as shown in Figures 1 to 4 and is generally composed of a coating section 20, a current collector delivery section 30, transport rollers 36a to 36n, a groove forming mechanism 40, a leveling roller 51, a drying oven 60, a winding and recovery section 70, and a control unit (not shown). In Embodiment 1, a groove-forming drive unit 47 and a leveling roller drive unit 57 are installed on the molding roller 41 of the groove-forming mechanism 40 and on the leveling roller 51 located downstream thereof. (As will be described later, these groove-forming drive unit 47 and leveling roller drive unit 57 are not essential, and in modified forms (not shown), they may not be provided at all. In that case, the molding roller 41 and leveling roller 51 will be rotated by the contact resistance with the active material layer 3. Also, if the groove formation is performed cleanly and the surface of the active material layer 3 is not roughened by the groove formation and the surface is kept flat (not shown), the leveling roller 51 is not required.) In Embodiment 1, there is one molding roller 41.

[0034] The current collector 1 used in this device A is made of a wide, long metal foil and is wound into a roll. This is referred to as the metal foil roll 1r. The current collector 1 is aluminum foil when it is the positive electrode and copper foil when it is the negative electrode.

[0035] The coating liquid 2 applied to the current collector 1 is, in the case of a positive electrode, a positive electrode active material mixture prepared by dispersing and kneading lithium transition metal composite oxides, such as LixCoO2, LixNiO2, LixMn2O4, LixMnO3, LixNiyCo(1-y)O2, etc., with a conductive material such as carbon black, a binder such as polyvinylidene fluoride (PVDF), and a solvent such as N-methyl-2-pyrrolidone (NMP).

[0036] In the case of the negative electrode coating solution 2, for example, it is a negative electrode active material mixture prepared by dispersing and kneading a lithium-doped and dedoped pyrolytic carbon, cokes such as pitch coke, needle coke, and petroleum coke, graphites, glassy carbons, phenolic resins, furan resins, etc., carbonaceous materials such as carbon fibers and activated carbon, and conductive polymer materials such as polyacetylene and polypyrrole with a conductive substance such as carbon black, a binder such as polyvinylidene fluoride (PVDF), and a solvent such as N-methyl-2-pyrrolidone (NMP).

[0037] Next, the device A will be described. The current collector delivery unit 30 is the unit that supports and rotates the metal foil roll 1r, which is wound into a roll shape, and feeds it out to the current collector 1 in the direction of the die 21. The current collector 1 is fed out by a feeding servo motor (not shown).

[0038] The coating section 20, which includes the die 21, consists of the die 21 and a coating liquid supply section 25 that supplies the coating liquid 2 to the die 21 in the correct amount by pump operation. The coating roller 34 is positioned directly opposite the die 21. The die 21 has a tapered cross-section, and a liquid reservoir 22 is formed inside it, which serves as a space for accumulating the coating liquid 2 formed from the active material. This liquid reservoir 22 is connected to a slit-shaped nozzle opening 23. The nozzle opening 23 extends along the width direction of the current collector 1. The coating liquid 2 is applied to the current collector 1 with a width dimension approximately the same as the width dimension of the nozzle opening 23.

[0039] A coating liquid supply unit 25 is connected to the liquid reservoir unit 22 to supply the coating liquid 2. The direction in which the coating liquid 2 stored in the liquid reservoir unit 22 flows from the nozzle opening 23 to the current collector 1 is perpendicular to the surface of the current collector 1, and the coating is applied along the feeding direction of the current collector 1.

[0040] The liquid reservoir 22 can store the coating liquid 2 supplied from the coating liquid supply unit 25, and the coating liquid 2 stored in the liquid reservoir 22 is discharged by pump pressure from the nozzle opening 23 to the current collector 1 which is sent roll-to-roll, thereby coating the current collector 1 with the coating liquid 2. The thickness of the coating liquid 2 film (active material layer 3) applied on the current collector 1 is designed to be approximately constant in the width direction.

[0041] The current collector 1 is guided in one direction by a coating roller 34 positioned directly opposite the die 21. The distance between the current collector 1 and the slit-shaped nozzle opening 23 of the die 21 is kept constant, and the coating liquid 2 is applied in this state. The width direction of the nozzle opening 23 of the die 21 is parallel to the direction of the rotation centerline of the coating roller 34. The width of the nozzle opening 23 is narrower than the width of the current collector 1, and an uncoated portion (ear portion 1b) of a certain width is generated on the side edge 3a of the extruded active material layer 3 and the side edge 1a of the current collector 1. Before and after the coating roller 34, a transport roller 36a on the inlet side and a transport roller 36b on the outlet side are rotatably provided to guide the current collector 1. The entire transport roller system is denoted by reference numeral 36.

[0042] The current collector 1, unwound from the current collector delivery unit 30, is transported at a predetermined speed while maintaining a predetermined tension by the rotational drive of a plurality of transport rollers 36a to 36n arranged at predetermined intervals. The transport surface of the current collector 1 by the transport rollers 36a to 36n is represented by the symbol M. The rotational speed of the metal foil roll 1r in the current collector delivery unit 30, the winding speed of the winding and retrieval unit 70, and the rotational speed of the transport rollers 36a to 36n are controlled by a control unit (not shown).

[0043] A groove-forming mechanism 40 is provided downstream of the coating section 20 (Figures 2 and 3). The groove-forming mechanism 40 of Embodiment 1 mainly consists of one molding roller 41, a molding backup roller 45 directly opposite it, a molding roller vibration generating section 46, and a groove-forming drive section 47. The molding roller 41 is positioned on the active material layer 3 side, and the molding backup roller 45 is positioned on the opposite side via the current collector 1 and is in contact with the back surface of the current collector 1. The straight line connecting the rotation centers of the molding roller 41 and the molding backup roller 45 is perpendicular to the current collector 1 (in other words, the conveying surface M). The molding backup roller 45 is configured to constantly press the current collector 1 against the clamping roll portion 41k (described later) of the molding roller 41 with a constant pressure using a support member (not shown).

[0044] As shown in Figure 3, the forming roller 41 consists of a rotating shaft 42 and disc-shaped flanges 43 protruding from the surface of the rotating shaft 42. The rotating shaft 42 consists of a main shaft 42a supported by bearings, a forming shaft portion 42b made of a different material from the main shaft 42a and fixed to the main shaft 42a and rotating together, clamping roll portions 41k provided on both sides of the forming shaft portion 42b, and disc-shaped flanges 43 protruding in multiple rows at regular intervals from the outer circumference of the forming shaft portion 42b.

[0045] The main shaft 42a and the clamping roll section 41k are made of a metal material such as iron, but the forming shaft section 42b and the disc-shaped flange 43 that protrudes integrally from the forming shaft section 42b and contacts the active material layer 3 are made of a non-conductive material selected from one of ceramics, engineering resin (for example, Delrin®), wood, or rubber.

[0046] The length of the molding shaft portion 42b is set to match the width of the nozzle opening 23 of the die 21. As described above, the molding shaft portion 42b is provided with multiple rows of disc-shaped flanges 43 for forming grooves at regular intervals. The distance between the two outermost disc-shaped flanges 43 is set to be slightly narrower than the width of the active material layer 3, so that a large number of grooves 3m are formed by the disc-shaped flanges 43 at predetermined intervals.

[0047] On both sides of the molding shaft portion 42b, clamping roll portions 41k are provided so as to rotate integrally with the main shaft 42a. The clamping roll portions 41k are provided so as to coincide with the ear portions 1b of the current collector 1, and the clamping roll portions 41k contact the surface of the current collector 1 at the ear portions 1b. Since the current collector 1 is transported at high speed in one direction on the transport rollers 36a to 36n, if there is no means of suppression in the groove forming mechanism 40, micro-vibrations will occur perpendicular to the transport direction. These micro-vibrations will cause uneven formation of the grooves 3m, so the groove forming mechanism 40 needs to suppress them. Therefore, a forming backup roller 45 is provided so as to face the forming roller 41 via the current collector 1.

[0048] The molding backup roller 45 is a cylindrical member, mounted on the opposite side of the molding roller 41 via the current collector 1, and in contact with the back side of the current collector 1. The straight line connecting the rotation center of the molding backup roller 45 and the rotation center of the molding roller 41 is set to be perpendicular to the current collector 1 (in other words, the conveying surface M). The portions of the molding shaft portion 42b that face the clamping roll portions 41k at both ends are the clamping roll portions 45k of the molding backup roller 45. The molding backup roller 45 is constantly pressed against the clamping roll portions 41k of the molding roller 41 by a support base (not shown), as indicated by the arrow (Figure 4).

[0049] As described above, in the groove forming mechanism 40, the current collector 1 is transported on the molding backup roller 45 and moves on the transport surface M, which is a virtual plane passing through the apex of the molding backup roller 45 on the side of the clamping roll portion 41k, by the upper and lower clamping roll portions 41k and 45k. The clamping roll portion 45k of the molding backup roller 45 is provided so as to be constantly pressed against the clamping roll portion 41k of the molding roller 41, and this clamping suppresses minute vibrations of the current collector 1 in the vertical direction (in other words, in the direction perpendicular to the transport direction) in the groove forming mechanism 40.

[0050] Here, the relationship between the clamping roll section 41k and the disc-shaped flange 43 will be explained. The radius of the disc-shaped flange 43 is smaller than the radius of the clamping roll section 41k, so that the tip of the disc-shaped flange 43 does not come into contact with the surface of the current collector 1 when the groove 3m is formed. In other words, the height of the forming roller 41 is set so that the gap S43 between the tip of the disc-shaped flange 43 on the active material layer 3 side and the coating surface of the current collector 1 is smaller than the thickness T3 of the active material layer 3 before the groove 3m is formed.

[0051] The cross-sectional shape of the disc-shaped flange 43 can range from a narrow V-shape to a wide V-shape, or it can be a semi-elliptical or rectangular shape. When the cross-sectional shape of the disc-shaped flange 43 is V-shaped, the adhesion of the active material to the disc-shaped flange 43 is more easily suppressed by the addition of ultrasonic vibration, as described later.

[0052] The groove forming drive unit 47 of the groove forming mechanism 40 consists of a groove forming drive motor 47m, a timing belt 47t, a drive pulley 47p, and a driven pulley 47q. The drive pulley 47p is mounted on the drive shaft of the groove forming drive motor 47m, and the driven pulley 47q is mounted on the main shaft 42a. The timing belt 47t is stretched between the drive pulley 47p and the driven pulley 47q, transmitting the rotation of the groove forming drive motor 47m to the driven pulley 47q. This drive force transmission system can also be replaced with gears.

[0053] The molding roller vibration generating section 46 is a section that applies micro-vibrations with small axial amplitude and high frequency to the molding shaft section 42b. The micro-vibrations are generated by applying a voltage to a piezoelectric element, causing the ceramic to vibrate slightly, thereby generating micro-vibrations of various frequencies, from high frequency to ultrasonic. In the embodiment shown in the figure, the molding roller vibration generating unit 46 is composed of a vibration generating block consisting of a piezoelectric element 461, an electrode plate 462, a front plate 463, a backing plate 464 and a tightening bolt 46f, and a spring 465. Multiple piezoelectric elements 461 and electrode plates 462 are provided and arranged alternately. They are sandwiched between a front plate 463 and a backing plate 464, and tightened with a fastening bolt 46f. By rotating the fastening bolt 46f to expand or contract the gap between the front plate 463 and the backing plate 464, the pressing force on the piezoelectric element 461 can be changed, thereby changing the amplitude of the vibration generating block. The vibration generating block of this molding roller vibration generating unit 46 is installed at one end of the molding shaft 42b, and a spring 465 is installed at the other end. The spring 465 constantly applies a pressing force to the molding shaft 42b in the direction of the piezoelectric element 461. (Note that if the vibration generating block including the piezoelectric element 461 is fixed to one end of the molding shaft 42b, the spring 465 can be omitted.) The piezoelectric element 461 is a polycrystalline ceramic made by sintering high-purity powder (titanium oxide, barium oxide, etc.) at high temperatures. When a voltage is applied, it deforms and can generate ultrasonic vibrations (longitudinal waves "compression waves" and transverse waves) in the range of several kHz to several MHz.

[0054] In addition to the clamping rolls 41k and 45k described above, in this embodiment, transport rollers 36f and 36g are provided on the upstream and downstream sides of the molding roller 41 and the molding backup roller 45, respectively. Transport rollers 36c and 36d are provided directly opposite the transport rollers 36f and 36g, respectively. The ear portion 1b of the current collector 1 is clamped from both sides by the transport rollers 36f, 36c, 36g, and 36d. The portion of these conveyor rollers 36f and 36g corresponding to the active material layer 3 is thin and designed not to come into contact with the active material layer 3. Conveyor rollers 36f and 36g are part of the conveyor rollers 36a to 36n. As a result, slight vertical vibrations of the current collector 1 caused by high-speed transport are reliably suppressed before and after the molding roller 41, and the current collector 1 does not vibrate vertically while being transported during the formation of the groove 3m by the molding roller 41, allowing the groove 3m to be formed to an accurate depth.

[0055] The leveling roller 51 is installed downstream of the downstream conveying roller 36g on the active material layer 3 side. As shown in Figure 3, the leveling roller 51 consists of a main shaft 51a supported by bearings, a leveling shaft portion 51b made of a different material from the main shaft 51a and fixed to the main shaft 51a and rotating together, and leveling clamping roll portions 51k provided on both sides of the leveling shaft portion 51b. The length of the leveling shaft portion 51b is set to match the width of the active material layer 3. The leveling clamping roll portions 51k are provided to coincide with the ear portion 1b of the current collector 1, and the leveling clamping roll portions 51k contact the surface (coating surface) of the current collector 1 at the ear portion 1b. The main shaft 51a and the leveling clamping roll section 51k are made of a metallic material such as iron, but since the leveling shaft section 51b comes into contact with the active material layer 3, it is made of a non-conductive material selected from one of the following: ceramics, engineering resin (e.g., Delrin®), wood, or rubber. This prevents conductive contaminants from entering the active material layer 3. Furthermore, a leveling backup roller 55 is provided so as to face the leveling roller 51 via the current collector 1.

[0056] The leveling and clamping roll section 51k, which corresponds to the ear portion 1b, is made with a large diameter, while the portion corresponding to the active material layer 3 (this portion is referred to as the leveling roll section 51n) is formed with a smaller diameter. Then, a leveling backup roller 55 is installed facing the leveling roller 51 via the current collector 1.

[0057] The active material layer 3 with grooves 3m formed on it is slightly raised between the grooves 3m. Let Tm be the thickness of the active material layer 3 with grooves 3m formed on it. The thickness Tm of the active material layer 3 is slightly thicker than the thickness T3 of the active material layer 3 before the formation of grooves 3m, and its surface is roughened by the formation of grooves 3m. Since it is necessary to smooth the surface of this active material layer 3, the smoothing roll section 51n comes into contact with the surface of the active material layer 3 with grooves 3m formed on it and smooths its surface. Thus, the height of the active material layer 3 is determined by the height of the smoothing roll section 51n. The height of the smoothing roll section 51n is set so that its outer surface comes into contact with the surface of the active material layer 3 with grooves 3m formed on it and slightly presses it down. That is, the gap S51 between the outer surface of the smoothing roll section 51n (i.e., the tip on the active material layer 3 side) and the surface of the current collector 1 is set to be slightly smaller than the thickness Tm of the active material layer 3 with grooves 3m formed on it. Of course, the height of the leveling roll section 51n may be adjusted to match the thickness T3 of the active material layer 3 before the formation of the groove 3m.

[0058] The leveling backup roller 55 is positioned similarly to the molding backup roller 45 described above, such that the line connecting the rotation center of the leveling roller 51 and the rotation center of the leveling backup roller 55 is perpendicular to the current collector 1. As can be seen from Figures 2 and 4, the leveling backup roller 55 of Embodiment 1 is cylindrical and contacts the current collector 1 with the entire width of the back surface of the current collector 1, and the leveling roll portion 51 k The current collector 1 is being transported while its ear portion 1b is being gripped.

[0059] The leveling roller 51 is equipped with a leveling roller drive unit 57, which has the same configuration as the groove-forming drive unit 47 of the molding roller 41. Specifically, the leveling roller drive unit 57 consists of a leveling roller drive motor 57m, a timing belt 57t, a drive pulley 57p, and a driven pulley 57q. The description of the groove-forming drive unit 47 will be used as a reference for details of the configuration and operation of the leveling roller drive unit 57. This drive force transmission system can also be replaced with gears. Furthermore, the leveling roller 51 is equipped with a leveling vibration generating unit 56, which has the same configuration as the molding roller vibration generating unit 46 of the molding roller 41. The leveling vibration generating unit 56 consists of a vibration generating block made of a piezoelectric element 561 and other components, and a spring 565. For details of the configuration of the leveling vibration generating unit 56, please refer to the description of the molding roller vibration generating unit 46.

[0060] The drying oven 60 is located downstream of the leveling roller 51. The drying oven 60 is surrounded by side walls and consists of a cylindrical body having a passage 66 through which a long current collector 1 passes, a heat source (such as a pipe through which high-temperature steam passes or an electric heater) which is provided as needed to heat and dry the current collector 1 as it moves through the passage 66, and a dryer which blows air to dry the current collector 1.

[0061] Inside the drying oven 60, multiple heat sources and dryers are arranged along the passage 66 of the current collector 1. The drying oven 60 dries the active material layer 3 formed on the current collector 1 by radiant heat from the heat sources and hot air from the dryers. In the embodiment shown in Figure 1, the groove forming mechanism 40 is installed upstream of the drying oven 60, but it may also be installed at the inlet portion 60a of the drying oven 60 where the active material layer 3 is kept in a semi-dried state (Figure 7).

[0062] The winding and retrieval section 70 is located on the opposite side of the current collector delivery section 30 and is the part that winds up the raw material roll 10, on which rectangular dry active material layers 3z are formed at predetermined intervals on one surface of the current collector 1, or a continuous dry active material layer (not shown), into a roll shape. Winding is performed by synchronizing a winding servo motor (not shown) so that the tension of the current collector 1, which is unwound in cooperation with the current collector delivery unit 30 via a dancer roller (e.g., transport roller 36a or 36n), which is one of the transport rollers 36, remains constant at all times. Furthermore, a compression roller (not shown) may be provided between the drying oven 60 and the winding and retrieval unit 70 to compress the raw material 10 from above and below, thereby increasing the density of the dried active material layer 3. The compression process of the active material layer 3 may also be performed after the winding and retrieval unit 70 of this apparatus A.

[0063] Next, the operation of device A will be described. In the steady-state operation of device A, the current collector 1 is fed out from the metal foil roll 1r of the current collector feed unit 30 by the operation of the current collector feed unit 30. A viscous coating liquid 2 is extruded from the die 21 towards the current collector 1 that has been sent out, and the coating liquid 2 is applied to the surface of the current collector 1 within the width of the nozzle opening 23 of the die 21. The applied film-like coating liquid 2 forms the active material layer 3.

[0064] In the case of continuous coating, the coating liquid 2 is continuously pushed out onto the surface of the current collector 1 as the current collector 1 moves, forming a strip-shaped active material layer 3. In the case of intermittent extrusion, the coating liquid 2 is extruded intermittently to form rectangular active material layers 3 on the surface of the current collector 1 at regular intervals. The areas where the active material layer 3 is formed and the areas where it is not formed (uncoated regions) appear alternately. The uncoated region between the side edge 1a of the current collector 1 and the side edge 3a of the active material layer 3 is the ear portion 1b. The active material layer 3 formed in this way is a viscous paste and is sent to the groove forming mechanism 40 while coated onto the strip-shaped current collector 1.

[0065] As shown in Figures 1 to 4, the groove-forming mechanism 40 of Embodiment 1 is a single-stage structure in which multiple disc-shaped flanges 43 for forming grooves are installed on the molding shaft portion 42b that constitutes the molding roller 41, and is installed on the upstream side of the drying oven 60. As described above, the molding roller 41 is equipped with a recess molding roller vibration generating unit 46 and a recess groove forming drive unit 47. The recess groove forming drive motor 47m of the recess groove forming drive unit 47 rotates the molding roller 41 via a drive pulley 47p, a timing belt 47t, and a driven pulley 47q, causing the disc-shaped flange 43 of the molding roller 41 to rotate in synchronization with the transport speed of the current collector 1.

[0066] Since the disc-shaped flange 43 rotates in sync with the transport speed of the current collector 1, when the active material layer 3 reaches the disc-shaped flange 43, the disc-shaped flange 43 smoothly enters the semi-dried active material layer 3 and forms a groove 3m in the active material layer 3 in accordance with the transport of the current collector 1. Semi-dried means that the surface of the active material layer 3 is dry, but the inside remains in a paste-like or clay-like state.

[0067] Since the radius of the disc-shaped flange 43 is smaller than the radius of the clamping roll portion 41k, when the groove 3m is formed, the lower edge of the disc-shaped flange 43 does not reach the current collector 1 and does not damage the current collector 1. The groove 3m formed by the disc-shaped flange 43 extends in the transport direction as the current collector 1 is transported. At this time, the active material between the disc-shaped flanges 43 is pushed inward by the disc-shaped flanges 43, but since there is no place for it to escape, it bulges out on both sides of the groove 3m, forming protrusions 3t, as shown in Figure 4. At this time, excessive molding pressure is not applied to the molding roller 41. Figure 6(a) is a perspective view of the active material layer 3 with the protrusions 3t formed. Alternatively, the convex burr 3v may be formed with an inverted V-shaped cross-section (Figure 6(b)).

[0068] During the formation of the grooves, the molding roller vibration generating unit 46 operates, applying axial high-frequency (including ultrasonic) micro-vibrations to the disc-shaped flange 43 via the molding shaft portion 42b of the molding roller 41. These high-frequency micro-vibrations suppress the adhesion of the active material to the disc-shaped flange 43 during groove formation. The adhesion suppression effect is further enhanced when the high-frequency micro-vibrations are ultrasonic. At the same time, these high-frequency micro-vibrations make the density of the surface layer of the active material layer 3 more uniform.

[0069] The active material layer 3, on which grooves 3m have been formed, is then fed to the next leveling roller 51. The leveling roller 51 is equipped with a leveling roller drive unit 68 and a leveling vibration generating unit 56. As described above, the leveling roller drive unit 68 has the same structure as the groove forming drive unit 47, and the leveling vibration generating unit 56 has the same structure as the molding roller vibration generating unit 46. The leveling roll portion 51n of the leveling roller 51 contacts the surface of the fed-in active material layer 3 and pushes back any portion higher than the leveling roll portion 51n, making the surface of the active material layer 3 a uniform height. At the same time, the leveling vibration generating unit 56 installed on the leveling roller 51 suppresses the adhesion of the active material to the leveling roll portion 51n with its high-frequency micro-vibrations.

[0070] As described above, this device A separates the groove forming process and the leveling process, thereby distributing the pressure generated during the groove forming and leveling processes, which were previously performed simultaneously, to the forming roller 41 and the leveling roller 51, enabling high-speed transport of the current collector 1.

[0071] After being leveled in this manner, the current collector 1 is sent to the drying oven 60. In the drying oven 60, the active material layer 3 is gradually dried from the surface inward by radiant heat from a drying heat source and exposure to drying air from a dryer. Once grooves 3m are formed in the active material layer 3, any solvent or moisture that remained inside the active material layer 3 escapes through the grooves 3m, accelerating the drying of the active material layer 3. As the drying of the active material layer 3 is accelerated, the drying time and the distance required for drying are naturally shortened, and as a result, the overall length of the drying oven 60 can be shortened. Once drying is complete, the current collector 1 becomes a raw material roll 10 for secondary batteries and is wound onto the winding and recovery unit 70.

[0072] (Modification 1 of Embodiment 1) In the embodiment shown in Figure 2, an example is shown in which a groove 3m is formed on the surface of the active material layer 3 by a single molding roller 41. In the embodiment shown in Figure 12, the spacing between the disc-shaped flanges 43 is narrow, and multiple (three in the figure) molding rollers 41a, 41b, and 41c are installed in sequence. Disc-shaped flanges 43 are provided on each molding roller 41a, 41b, and 41c at a partially narrow pitch. In the embodiment shown in the figure, the molding area of ​​the disc-shaped flange 43 is divided into three sections and arranged in a staggered pattern on the molding rollers 41a, 41b, and 41c. A groove forming drive motor 47m1, 47m2, and 47m3 are installed on each molding roller 41a, 41b, and 41c, respectively, to provide synchronous rotation to the disc-shaped flange 43. Molding roller vibration generating units 46a, 46b, and 46c are installed on the opposite side of the groove forming drive motors 47m1, 47m2, and 47m3, respectively. Each of the forming rollers 41a, 41b, and 41c has forming backup rollers 45a, 45b, and 45c positioned directly opposite it. This makes it possible to form grooves 3m long with a narrower pitch. Although not shown in the diagram, the groove forming drive motor 47m1, 47m2, and 47m3 may be combined into a single unit, and the forming rollers 41a, 41b, and 41c may be driven by a gear train. (The diagram has been enlarged in the width direction for illustrative purposes.)

[0073] (Modification 2 of Embodiment 1) In Embodiment 1, an example was shown in which the groove forming mechanism 40 is provided with a molding roller vibration generating unit 46 and a groove forming drive unit 47, and the leveling roller 51 is provided with a leveling vibration generating unit 56 and a leveling roller drive unit 57. However, depending on the state of the active material layer 3, the active material may not adhere when forming the grooves 3m, resulting in the formation of clean grooves 3m. In such cases, the molding roller vibration generating unit 46 and the leveling vibration generating unit 56 can be omitted.

[0074] If the groove-forming drive unit 47 and the leveling roller drive unit 57 are omitted, the molding roller 41 and leveling roller 51 can be made to rotate freely with bearing support. In this case, when the molding roller 41 and leveling roller 51 come into contact with the active material layer 3, they rotate freely due to the contact resistance when the active material layer 3 moves, forming grooves 3m and adjusting the height of the surface layer of the active material layer 3 and flattening the surface.

[0075] (Embodiment 2) Embodiment 2 is the case of coating on both sides. Figure 8 shows an example where coating liquid 2 is applied to both sides of a horizontally conveyed current collector 1, with dies 21-21 positioned on its front and back. Figure 9 shows a case where dies 21-21 are positioned directly opposite each other on the front and back of a vertically lifted current collector 1, and coating is performed simultaneously. Therefore, downstream of the dies 21-21, in the area where the active material layers 3-3 are formed, a conveying roller (not shown) that grips the ear portion 1b is provided up to the outlet of the drying oven 60.

[0076] In the groove-forming mechanism 40-40, a cylindrical molding backup roller 45 is not provided, and molding rollers 41-41 with the same configuration are installed on both sides of the current collector 1. The disc-shaped flanges 43-43 of the molding rollers 41-41 are provided at the same position on the top and bottom as shown in Figure 1, and the disc-shaped flanges 43-43 approach the current collector 1 from both sides to form grooves 3m-3m in the active material layers 3-3 on both sides. As a result, grooves 3m-3m are formed at the same position in the active material layers 3-3 on both sides. In the groove forming mechanism 40-40, the ear portion 1b is gripped and conveyed by the gripping roll portions 41k-41k of the front and back forming rollers 41-41.

[0077] The same applies to the leveling rollers 51-51; a leveling backup roller 55 is not provided, and leveling rollers 51-51 with the same configuration are installed on both sides of the current collector 1 (Figure 11). The leveling roll portions 51n-51n of the leveling rollers 51-51 on the front and back sides contact the surface of the active material layers 3-3 on the front and back sides, leveling them to a certain height and simultaneously flattening their surfaces. In addition, with the leveling rollers 51-51, the ear portion 1b is gripped and conveyed by the leveling clamping roll portions 51k-51k on both sides, similar to Embodiment 1. The remaining points are the same as in Embodiment 1.

[0078] As described above, the present invention makes it possible to form neat grooves of uniform depth on the surface of the active material layer coated on one or both sides of the current collector 1 during high-speed transport, and to significantly reduce the subsequent drying time without degrading battery performance. [Explanation of Symbols]

[0079] A: Manufacturing equipment for raw materials used in secondary batteries M: Conveyor surface S43: Gap between the tip of the disc-shaped flange on the active material layer side and the current collector. S51: Gap between the tip of the leveling roller on the active material layer side and the surface of the current collector. T3: Thickness of the active material layer Tm: Thickness of the active material layer where grooves are formed. 1: Current collector 1a: Side edge 1b:Ear part 1r: Metal foil roll 2: Coating liquid 3: Active material layer 3a: Side edge 3m: Concave groove 3t: ridge 3v: Convex burr 3z: Dry active material layer 10: Original fabric 20: Coating Department 21: Die 22: Liquid reservoir 23: Nozzle opening 25: Coating liquid supply unit 30: Current collector output section 34: Coating roller 36 (36a~36f, 36g~36n): Conveyor rollers 40: Groove formation mechanism 41(41a, 41b, 41c): Forming roller 41k: Clamping Roll Section 42: Rotation axis 42a: Main shaft 42b: Molded shaft part 43: Disc-shaped flange 45 (45a, 45b, 45c): Molding backup roller 45k: Clamping roll section 46(46a, 46b, 46c): Molding roller vibration generation section 461: Piezoelectric element 462: Electrode plate 463: Front plate 464: Backing board 465: Spring 47: Groove Forming Drive Unit 47m (47m1, 47m2, 47m3): Groove molding drive motor 47p: Drive pulley 47q: Driven pulley 47t: Timing belt 51: Leveling roller 51a: Main shaft 51b: Leveling shaft 51k: Leveling and clamping roll section 51n: Leveling roll section 55: Leveling backup roller 56: Leveling vibration generation section 561: Piezoelectric element 565: Spring 57: Leveling roller drive unit 57m: Leveling roller drive motor 57p: Drive pulley 57q: Driven pulley 57t: Timing belt 60: Drying oven 60a: Entrance part 66: Passage route 70: Winding and retrieval section

Claims

1. In a groove-forming mechanism 40 of a secondary battery raw material 10 manufacturing apparatus A, the process includes forming an active material layer 3 on one surface of a long, strip-shaped current collector 1 that is conveyed in one direction, forming grooves 3m on the surface of the active material layer 3 which has become a semi-dried, clay-like state, and drying the active material layer 3 on which the grooves 3m have been formed, The groove forming mechanism 40 that forms grooves 3m on the surface of the active material layer 3 is A molding roller 41 positioned on the active material layer 3 side, A molding backup roller 45 is positioned opposite the molding roller 41 on the opposite side of the active material layer 3, with the current collector 1 in between, and rotates while in contact with the other side of the current collector 1. It consists of a molding roller vibration generating unit 46 connected to the molding roller 41 and which applies vibration to the molding roller 41, The molding roller 41 is Rotating shaft 42 and A groove-forming mechanism for a secondary battery raw material manufacturing apparatus, comprising a disc-shaped flange 43 arranged in multiple rows on the rotating shaft 42 and having a larger diameter than the rotating shaft 42, wherein the gap S43 between the tip of the disc-shaped flange 43 on the active material layer 3 side and the active material coated surface of the current collector 1 is set to be smaller than the thickness T3 of the active material layer 3 before groove 3m is formed.

2. The groove forming mechanism for a secondary battery raw material manufacturing apparatus according to claim 1, characterized in that gripping rolls 41k and 45k are provided on the molding roller 41 and the molding backup roller 45, respectively, at positions that coincide with the ear portion 1b to which the active material layer 3 is not coated, and are located between the side edge 3a of the active material layer 3 and the side edge 1a of the current collector 1.

3. In a groove forming mechanism 40,40 of a secondary battery raw material A manufacturing apparatus, the first and second active material layers 3,3 are formed on both sides of a long, strip-shaped current collector 1 that is conveyed in one direction; first and second grooves 3m,3m are formed on the surface of the first and second active material layers 3,3 which have become clay-like in a semi-dried state; and the first and second active material layers 3,3 with the grooves 3m,3m formed are dried. The first and second groove forming mechanisms 40, 40, which form the first and second grooves 3m, 3m in the first and second active material layers 3, 3 respectively, The first and second molding rollers 41, 41 are respectively positioned on the first and second active material layers 3, 3 sides, It consists of first and second molding roller vibration generating units 46, 46, which are connected to the first and second molding rollers 41, 41 respectively and apply vibration to the first and second molding rollers 41, 41, The first and second molding rollers 41, 41 are The first and second rotating shafts 42, 42, It is composed of first and second disc-shaped flanges 43, 43 which are arranged in multiple rows on the first and second rotating shafts 42, 42 and face each other at mutually coincidental positions, and which have a larger diameter than the first and second rotating shafts 42, 42, A groove forming mechanism for a secondary battery raw material manufacturing apparatus, characterized in that the gap S43, S43 between the tip of the first and second disc-shaped flanges 43, 43 on the active material layer 3, 3 side and the current collector 1 is set to be smaller than the thickness T3, T3 of the first and second active material layers 3, 3 before the groove 3m, 3m is formed.

4. The groove forming mechanism for a secondary battery raw material manufacturing apparatus according to claim 3, characterized in that gripping rolls 41k, 41k for gripping the ear portion 1b are provided on the first and second molding rollers 41, 41, respectively, at positions that coincide with the ear portion 1b to which the active material layer 3, 3 is not coated, and are located between the side edges 3a, 3a of the active material layer 3, 3 and the side edges 1a, 1a of the current collector 1.

5. The groove forming mechanism for a secondary battery raw material manufacturing apparatus according to claim 1 or 3, characterized in that the vibration source of the molding roller vibration generating section 46 (46, 46) is an ultrasonic generator.

6. The groove forming mechanism for a secondary battery raw material manufacturing apparatus according to claim 1 or 3, characterized in that the disc-shaped flange 43 (43, 43) is formed of one non-conductive material selected from ceramics, resin, wood, or rubber.

7. Further downstream of the groove forming mechanism 40 (40, 40), leveling rollers 51 (51, 51) are installed. The groove forming mechanism for a secondary battery raw material manufacturing apparatus according to claim 1 or 3, characterized in that the gap S51 (S51, S51) between the tip of the leveling roll portion 51n (51n, 51n) of the leveling roller 51 (51, 51) that contacts the active material layer 3 (3, 3) in which the groove 3m (3m, 3m) is formed, on the active material layer 3 (3, 3) side, and the surface of the current collector 1 is set to be smaller than the thickness Tm (Tm, Tm) of the active material layer 3 (3, 3) in which the groove 3m (3m, 3m) is formed.

8. The groove forming mechanism for a secondary battery raw material manufacturing apparatus according to claim 7, characterized in that the leveling roll section 51n (51n, 51n) is formed of one non-conductive material selected from ceramics, resin, wood, or rubber.

9. The groove forming mechanism for a secondary battery raw material manufacturing apparatus according to claim 1 or 3, characterized in that the forming roller 41 (41, 41) is connected to a groove forming drive motor 47m (47m, 47m) which is synchronized with the transport speed of the current collector 1.

10. The groove forming mechanism for a secondary battery raw material manufacturing apparatus according to claim 7, characterized in that the leveling roller 51 (51, 51) is connected to a leveling roller drive motor 57m (57m, 57m) which is synchronized with the transport speed of the current collector 1.

Images