JP2012204031A - Device for forming active material layer and method for forming the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for forming an active material layer capable of enhancing performance of a battery, and to provide a method for forming the same.SOLUTION: The device for forming the active material layer comprises: a mold member 20 having a plurality of recess parts 22 on its surface; a feeding mechanism 30 for feeding an active material substance into at least the plurality of the recess parts 22 in the mold member 20; a support plate 41 for supporting a collector 2; a pressing mechanism 40 for pressing the collector 2 toward the active material substance fed into the mold member 20; and a heater that is built into the mold member 20 so as to heat the active material substance pressed by the pressing mechanism 40.

Description

  The present invention relates to an active material layer forming apparatus and a forming method.

  In recent years, in order to improve the charge / discharge characteristics of a secondary battery such as a lithium ion secondary battery, an active material layer having a concave and convex shape is formed on a current collector, and the counter electrode active material is opposed to the electrolyte layer. A battery electrode having a large surface area with respect to the layer has been proposed. As a method for manufacturing such a battery electrode, for example, a method described in Japanese Patent Application Laid-Open No. 2008-10253 (Patent Document 1) is known. In this method, first, an active material is applied on a current collector and then dried to form a flat active material layer on the current collector. Next, using a roll press apparatus, the active material layer is compressed by pressing a roll-shaped mold having an uneven surface against the active material layer formed on the current collector and compressing the active material layer. Mold into shape.

Japanese Patent Laying-Open No. 2008-10253 (for example, paragraphs 0047 and 0048, FIG. 9)

  According to the method for forming an active material layer described in Patent Document 1 described above, there arises a problem that the performance of the battery is degraded. The cause of this problem is, first, in order to form the active material layer solidified by drying into a concavo-convex shape, the active material is pressed by a mold at a high pressure of 10 MPa, for example. As a result, the active material particles in the active material layer are crushed. Secondly, the compressibility of the convex portion of the active material layer pressed by the concave portion of the mold is lower than the compressibility of the concave portion of the active material layer pressed by the convex portion of the mold. As a result, the density of the active material particles in the convex portion becomes smaller than the density of the active material particles in the concave portion of the active material layer, and the density of the active material particles in the active material layer becomes non-uniform. Third, the internal state in the vicinity of the surface of the active material layer after drying is different from the internal state in a portion away from the surface. When the active material layer is molded with a mold after drying, the surface of the active material layer near the top surface and the bottom surface of the recess remains after drying, and the side surface of the recess of the active material layer (side surface of the protrusion) is separated from the surface after drying. A portion is formed exposed on the surface. As a result, the internal structure in the vicinity of the surface of the active material layer formed into an uneven shape becomes uneven.

  In view of the above points, an object of the present invention is to provide an active material layer forming apparatus and a forming method capable of improving battery performance.

  According to a first aspect of the present invention (active material layer forming apparatus), a mold member having a plurality of recesses on the surface thereof, a supply means for supplying an active material material into at least the plurality of recesses of the mold member, Support means for supporting the electric body, pressing means for pressing the current collector supported by the supporting means against the active material supplied to the mold member by the supplying means, and an active material being pressed by the pressing means And heating means for heating the material.

  According to the first aspect of the present invention, the active material supplied to the mold member by the supply unit is heated by the heating unit while being pressed by the current collector by the pressing unit. As a result, an active material layer having a plurality of convex portions that are dried and contracted is formed on the current collector. In addition, since the active material before being dried and solidified is pressed and molded, it is not necessary to press the active material at a high pressure. As a result, the active material particles in the active material layer are prevented from being crushed, and the density uniformity of the active material particles is also improved. Furthermore, since the active material layer is dried after molding, the uniformity in the internal structure near the surface of the active material layer is improved.

  According to a second aspect of the present invention, in the first aspect, the mold member is a plate-shaped member having a plurality of recesses on the surface thereof, and the supply means discharges the active material toward the surface of the mold member And a moving means for relatively moving the nozzle along the surface of the mold member. The pressing means is supported by the support means for the active material supplied to the mold member by the supply means. And a displacement means for relatively displacing the current collector between a pressing position for pressing the current collector and a separating position located in a direction away from the mold member from the pressing position.

  According to the second aspect of the invention, the active material is discharged and supplied from the nozzle that moves relative to the plate-shaped mold member by the moving means. The active material supplied to the mold member is pressed by the current collector relatively displaced from the separated position to the pressed position by the displacing means.

  A third invention according to claim 3 is characterized in that, in the second invention, the heating means heats the mold member and heats the active material pressed by the pressing means. According to the third aspect of the invention, the mold member is heated by the heating means, whereby the active material material pressed by the pressing means is heated.

  A fourth invention according to claim 4 is characterized in that, in the third invention, the heating means has a heating source built in the mold member. According to the fourth aspect of the invention, the heating means heats the mold member by the heating source built in the mold member.

  According to a fifth aspect of the present invention, in the first aspect, the mold member is an annular member having a plurality of recesses on the outer surface thereof, and the supply means is an active material that faces the outer surface of the mold member. The pressing means displaces the outer surface of the mold member in the order of the position facing the nozzle, the position for pressing the current collector against the active material, and the position separating from the current collector. And a rotation driving means for rotating the mold member.

  According to the fifth aspect of the invention, the active material is supplied from the nozzle to the outer peripheral surface of the mold member that is rotated by the rotation driving means. The active material supplied to the outer peripheral surface of the mold member is heated by the heating means while passing through the position pressed by the current collector as the mold member rotates. Thereafter, the outer peripheral surface of the mold member is separated from the current collector in accordance with the rotation operation.

  The sixth invention according to claim 6 is characterized in that, in the fifth invention, the heating means heats the mold member and heats the active material pressed by the pressing means. According to the sixth aspect of the invention, the mold member is heated by the heating means, whereby the active material material pressed by the pressing means is heated.

  A seventh invention according to claim 7 is the invention according to any one of the first to sixth inventions, wherein the supplying means continuously supplies the active material to the region including the plurality of concave portions of the mold member. It is characterized by. According to the seventh aspect, the active material is filled in the plurality of recesses of the mold member, and the active material layer is formed on the region.

  According to an eighth aspect of the present invention, in any one of the first to sixth aspects, the supply means supplies the active material intermittently toward each of the plurality of recesses of the mold member. Features. According to the eighth aspect of the invention, the active material is filled in the plurality of concave portions of the mold member in an independent state.

  According to a ninth aspect of the present invention (active material layer forming method), there are provided a supply step of supplying an active material into at least a plurality of recesses of a mold member, and an active material supplied to the mold member by the supply step. On the other hand, there are a pressing step for pressing the current collector, a heating step for heating and drying the active material material pressed by the pressing step, and a plurality of convex portions after the heating step. And a separation step of separating the current collector having the active material layer from the mold member.

  According to the ninth aspect of the invention, the active material is supplied into at least the plurality of recesses of the mold member by the supplying process, and the current collector is pressed against the active material supplied to the mold member by the supplying process by the pressing process. Then, the active material pressed by the pressing step is heated by the heating step, and the active material is dried and contracts. The current collector provided with the active material layer having a plurality of convex portions is separated from the mold member after the heating step by the separation step. As a result, an active material layer having a plurality of convex portions that are dried and contracted is formed on the current collector. In addition, since the active material before being dried and solidified is pressed and molded, it is not necessary to press the active material at a high pressure. As a result, the active material particles in the active material layer are prevented from being crushed, and the density uniformity of the active material particles is also improved. Furthermore, since the active material layer is dried after molding, the uniformity in the internal structure near the surface of the active material layer is improved.

  According to a tenth aspect of the present invention, in the ninth aspect, the ratio of the depth to the width of the concave portion of the mold member is 1/2 or more, and the width dimension and height of the convex portion of the active material by the heating step The shrinkage ratio of dimensions is in the range of 10% to 50%, respectively. According to the tenth aspect of the invention, an active material layer having a plurality of high aspect ratio convex portions having a height to width ratio of 1/2 or more is formed. Further, the width and height dimensions of the convex portions of the active material material shrink within the range of, for example, 10% to 50% by the drying process, in other words, the width dimensions and height dimensions of the convex portions before shrinkage. Each of the dimensions is in the range of 90% to 50%, for example. As a result, when the active material layer is separated from the mold member in the separation step, the active material layer can be easily separated from the mold member without breaking the convex portions 4 of the active material layer.

  According to the invention of any one of claims 1 to 10, it is possible to provide an active material layer forming apparatus and a forming method capable of improving battery performance.

It is a figure showing typically a 1st embodiment of the present invention. It is a figure which shows a mold member. It is a figure which shows a press mechanism. It is a block diagram which shows an electric structure. It is a flowchart which shows the flow of operation | movement of 1st Embodiment. It is a figure which shows the state of operation | movement typically. It is a figure for demonstrating the shrinkage | contraction ratio of an active material layer. It is a figure which shows typically the operation state of a modification. It is a figure which shows 2nd Embodiment of this invention typically.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
<First Embodiment>
First, the configuration of the first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a diagram schematically showing a first embodiment of the present invention, FIG. 1 (a) is a side view, and FIG. 1 (b) is a front view. In this specification, the X, Y, and Z coordinate directions are defined as shown in FIG. An active material layer forming apparatus 1a shown in FIG. 1 is an apparatus used when manufacturing an electrode having an active material layer formed on a current collector, for example, an electrode for a lithium ion secondary battery. The active material layer forming apparatus 1 a is supplied to the mold member 20 having a plurality of recesses 22 on the surface thereof, a supply mechanism 30 for supplying an active material material into at least the recesses 22 of the mold member 20, and the mold member 20. A pressing mechanism 40 that presses the current collector against the active material is mainly provided.

  The mold member 20 is fixed to the upper surface of the base 9, and as shown in FIG. 2, the mold member 20 has a plurality of recesses 22 having a rectangular parallelepiped-shaped inner space extending in the X direction. They are formed in parallel. In addition, the side wall which forms the recessed part 22 is made into the convex part 23. FIG. As shown in FIG. 2, the mold member 20 includes a heater 24 incorporated so as to cover the periphery of the recess 22. The heater 24 is a heating source for heating the active material supplied to the mold member 20.

  The supply mechanism 30 includes a nozzle 31 as shown in FIG. The nozzle 31 extends in the X direction, and its lower portion is tapered. A discharge port (not shown) is formed at the lower end of the nozzle 31, and this discharge port is a slit-shaped discharge port extending in the X direction. The nozzle 31 is connected to a pump 39 (FIG. 4) for sending an active material to the nozzle 31 and discharging it from a discharge port, and a liquid supply / discharge mechanism (not shown) such as piping.

  The upper surface of the nozzle 31 is fixed to the lower surface of a beam (beam member) 33, and both ends of the beam 33 are supported by a pair of frames 32. Slide portions 34 are respectively provided at the lower ends of the pair of frames 32. Further, a pair of rails 35 extending in the Y direction are provided on the upper surface of the base 9 so as to sandwich the mold member 20. The pair of slide portions 34 are slidably connected to the pair of rails 35. A moving element 37 of the linear motor 36 is fixed to one side (−X direction side) of the pair of frames 32. Further, a stator 38 of a linear motor 36 that is opposed to the moving element 37 and extends in the Y direction is provided on the upper surface of the base 9.

  The supply mechanism 30 configured as described above drives the linear motor 36 to move the pair of frames 32, the beam 33, and the nozzle 31 integrally in the Y direction, thereby moving the nozzle 31 above the mold member 20. Move. Although only one side of the pair of frames 32 is driven by the linear motor 36, a linear motor may be provided on the other side to drive both sides in synchronization.

  The pressing mechanism 40 is a mechanism that raises and lowers the support plate 41 that supports the current collector 2 from the back surface side (the upper surface side in the drawing) with respect to the mold member 20. The support plate 41 holds the current collector 2 by a vacuum suction force or a mechanical chuck mechanism. The current collector 2 is a rectangular negative electrode current collector or positive electrode current collector, for example, a metal foil such as a copper foil or an aluminum foil. In the case of a thin metal foil, it is difficult to transport and handle, so it is preferable to improve the transportability by sticking one side to a carrier such as a glass plate. The support plate 41 is supported by a pair of arms 42 from above. As shown in FIG. 3, the ends in the X direction of the pair of arms 42 are slidably connected to a pair of rails 49 that are fixed to the frame 43 and extend in the vertical direction (Z direction). FIG. 3 is a side view (a) and a front view (b) for explaining the pressing mechanism 40, and illustration of the mold member 20 and the supply mechanism 30 is omitted.

  As shown in FIG. 3, the pair of arms 42 are fixed to each other by a connecting member 44. A nut portion (not shown) is provided near the center of the connecting member 44 in the Y direction, and a screw shaft 45 extending in the Z direction is screwed to the nut portion. The upper end of the screw shaft 45 is supported by a bearing member 461 and the lower end is supported by a bearing member 462 so as to be rotatable around the shaft. A driven pulley 471 is fixed to the lower portion of the screw shaft 45. The driven pulley 471 is connected to a driving pulley 472 fixed to a rotating shaft of a motor 48 provided on the base 9 via a belt 473.

  The pressing mechanism 40 configured as described above drives the motor 48 forward and backward to integrally raise and lower the pair of arms 42, the connecting member 44, and the support plate 41 above the mold member 20. The current collector 2 supported by 41 is moved in a direction approaching the mold member 20 or in a direction away from the mold member 20, and the position of the current collector 2 is displaced.

  The active material layer forming apparatus 1a includes a control unit 7 shown in FIG. 4, and the control unit 7 includes a computer having a CPU, a ROM, a RAM, and the like. The control unit 7 comprehensively controls operations of the supply mechanism 30 and the pressing mechanism 40 described above. The controller 24 is electrically connected to the heater 24, the pump 39, the linear motor 36, the motor 48, and the like described above.

The active material is, for example, a paste-like negative electrode active material or positive electrode active material used for a lithium ion secondary battery. When the active material is a negative electrode active material, for example, particulate lithium titanate (Li ₄ Ti ₅ O ₁₂ ) as a negative electrode active material, acetylene black or ketjen black as a conductive additive, binder Polyvinylidene fluoride (PVDF), styrene butadiene rubber (SBR), polyvinyl pyrrolidone (PVP), polyvinyl alcohol (PVA) or polytetrafluoroethylene (PTFE), N-methyl-2-pyrrolidone (NMP) as a solvent, etc. Can be used. The viscosity of the negative electrode active material is preferably, for example, about 1 mPa · s (Pascal second) to 100 Pa · s at a shear rate of 1 s ⁻¹ (1 / second). In addition to the above lithium titanate, for example, graphite, metallic lithium, SnO ₂ , an alloy system, or the like can be used as the negative electrode active material.

When the active material is a positive electrode active material, this positive electrode active material is, for example, particulate lithium cobaltate (LiCoO ₂ ) as a positive electrode active material, acetylene black as a conductive additive, and a binder. As a solvent, a mixture of polyvinylidene fluoride (PVDF) as a solvent, N-methyl-2-pyrrolidone (NMP) as a solvent, or the like can be used. As the positive electrode active material, in addition to LiCoO ₂ , LiNiO ₂ or LiFePO ₄ , LiMnPO ₄ , LiMn ₂ O ₄ , and LiMeO ₂ (Me = MxMyMz; Me and M are transition metals, x + y + z = 1) are representative. For example, LiNi _1/3 Mn _1/3 Co _1/3 O ₂ or LiNi _0.8 Co _0.15 Al _0.05 O ₂ can be used. The viscosity of the positive electrode active material 44 is preferably about 1 mPa · s to 100 Pa · s at a shear rate of 1 s ⁻¹ , for example, as with the negative electrode active material.

  Next, the operation of the first embodiment will be described with reference to FIGS. FIG. 5 is a flowchart showing an operation flow of the first embodiment, and FIG. 6 is a diagram schematically showing an operation state in each step shown in FIG.

  In step S <b> 10 of FIG. 5, the paste mechanism active material is continuously discharged from the discharge port of the nozzle 31 toward the upper surface of the mold member 20 while the nozzle 31 is moved in the Y direction on the mold member 20 by the supply mechanism 30. . By this step S10, the active material 5 is continuously supplied toward the region including the plurality of recesses 22 formed on the upper surface of the mold member 20 as shown in FIG. 6A. As a result, the active material 5 is filled into the plurality of concave portions 22 and the active material 5 is continuously supplied onto the plurality of convex portions 23, so that the active material 5 is applied to the region on the upper surface of the mold member 20. Are formed (application process). At this time, the support plate 41 stands by at a separation position that is a position separated upward from the mold member 20 while holding the current collector 2 supplied by an operator or a transport robot.

  In step S <b> 20 of FIG. 5, the support plate 41 is lowered toward the mold member 20 by the pressing mechanism 40. As shown in FIG. 6B, the current collector 2 held on the descending support plate 41 comes into contact with the active material 5 on the mold member 20, and then the active material 5 is pressed at a pressure of 5 MPa, for example. Press. As a result, the active material 5 filled in the concave portion 22 and the active material 5 on the convex portion 23 are compressed (pressing step). At this time, when the amount of the active material 5 supplied onto the convex portion 23 is large, the active material 5 on the convex portion 23 flows out of the mold member 20 from the mold member 20. Thus, the position of the current collector 2 in a state where the active material 5 is pressed by the current collector 2 is defined as a pressing position.

  In step S30 of FIG. 5, the active material 5 pressed by the current collector 2 by the pressing mechanism 40 is heated by the heater 24 built in the mold member 20. The mold member 20 is heated by the heater 24, and the active material 5 in contact with the mold member 20 is heated to, for example, 80 ° C. (80 degrees Celsius). When the active material 5 is heated in this way, the solvent component in the active material 5 is vaporized and escapes from the active material 5. As a result, as shown in FIG. 6C, the active material 5 contracts in the direction toward the inside, and the active material 5 filled in the recess 22 is separated from the surface of the recess 22. In this state, the active material 5 is dried and solidified to form an uneven active material layer 3 having a plurality of protrusions 4 on the current collector 2 (drying step).

  In step S40 of FIG. 5, the support plate 41 is raised from the pressing position toward the separation position by the pressing mechanism 40. As shown in FIG. 6D, the current collector 2 to which the active material layer 3 having the plurality of convex portions 4 has been transferred rises to the separation position and stops (separation step). Thereafter, the current collector 2 is removed from the support plate 41 by an operator or a transport robot.

  Here, the shrinkage ratio of the active material 5 in the above-described operation will be described. First, step S20 (pressing step) in FIG. 5, that is, the dimensions of the active material 5 in the state shown in FIG. 6B will be described with reference to FIG. Note that FIG. 7 is shown by inverting the vertical relationship in FIG. As shown in FIG. 7A, since the active material 5 is pressed in a state of being filled in the concave portion 22 of the mold member 20 in step S20, the width dimension w1 of the convex portion is in the Y direction of the concave portion 22. It is equal to the width dimension, for example, 100 μm. Moreover, the height dimension h1 of the convex part is equal to the depth dimension of the concave part 22, and is 50 μm, for example. The dimension s1 between the convex portions in the Y direction of the active material 5 is, for example, 100 μm. Moreover, the thickness dimension t1 of the active material 5 pressed between the upper surface of the convex portion 23 of the mold member 20 and the current collector 2 is, for example, 50 μm.

  Next, the dimensions of the active material 5 after step S30 (drying step) in FIG. 5, that is, in the state shown in FIG. 6C will be described with reference to FIG. Note that the width dimension w2 and the height dimension h2 of the protrusions 4 of the active material layer 3 shown in FIG. 7B are the active material materials shown in FIG. 5 is smaller than the width dimension w1 and the height dimension h1. The shrinkage ratio of the width dimension and the height dimension of the convex part 4 of the active material layer 3 is in the range of 10% to 50%, for example. If the shrinkage ratio is 50%, the width dimension w2 of the active material layer 3 is, for example For example, the height h2 is 25 μm. The dimension s2 between the convex portions 4 of the active material layer 3 is, for example, 150 μm, and the thickness dimension t2 in the concave portion of the active material layer 3 is, for example, 25 μm.

  As described above, the ratio of the depth dimension h1 (for example, 50 μm) to the width dimension w1 (for example, 100 μm) of the recess 22 is ½, and the active material 5 contracts with drying while maintaining this ratio. Therefore, the ratio of the height dimension h2 to the width dimension w2 of the projection 4 formed on the active material layer 3 is also halved, and the projection 4 having a high aspect ratio can be formed. Further, by increasing the ratio of the depth dimension h1 to the width dimension w1 of the concave portion 22 to more than one half, for example, within a range of 1 to 2, the aspect ratio of the convex portion 4 of the active material layer 3 is also reduced to one half. As described above, for example, the aspect ratio can be increased within a range of 1 to 2.

  Moreover, the width dimension w1 and the height dimension h1 of the convex part 4 of the active material 5 contract each within a range of, for example, 10% to 50% by the drying process, in other words, the width dimension w1 and the high dimension of the convex part 4 The dimension h1 is a dimension within a range of 90% to 50%, for example, before contraction. As a result, when the active material layer 3 is separated from the mold member 20 in the separation step, the active material layer 3 can be easily separated from the mold member 20 without the protrusions 4 of the active material layer 3 being destroyed. it can.

<Modification of First Embodiment>
Next, a modification of the first embodiment will be described. The configuration of the active material layer forming apparatus in this modification is the same as that in the first embodiment, and the coating operation in step S10 (coating step) shown in FIG. 5 is different from that in the first embodiment. In the first embodiment described above, the paste-form active material is continuously discharged from the discharge port of the nozzle 31 toward the upper surface of the mold member 20 while the supply mechanism 30 moves the nozzle 31 in the Y direction on the mold member 20. Thus, a layer of the active material 5 is formed on the upper surface of the mold member 20. On the other hand, in this modification, the active material 5 is intermittently supplied from the nozzle 31 toward each of the plurality of recesses 22 of the mold member 20.

  As shown in FIG. 8A, the supply mechanism 30 moves the nozzle 31 in the Y direction on the mold member 20, and removes the paste-like active material 5 from the discharge port of the nozzle 31. It supplies intermittently toward each of 22 (application | coating process). The supply amount of the active material 5 at this time is set to be slightly larger than the volume amount in the recess 22. This intermittent supply operation is realized by intermittently driving the pump 39 in synchronization with the movement of the nozzle 31 by the control unit 7. As a result, the active material 5 is filled into the plurality of recesses 22. The upper end height position of the filled active material 5 is slightly higher than the height position of the upper surface of the convex portion 23 of the mold member 23.

  Next, as shown in FIG. 8B, the support plate 41 is lowered toward the mold member 20 by the pressing mechanism 40, and the active material 5 is moved by the current collector 2 held by the support plate 41 at the pressing position. For example, pressing is performed at a pressure of 5 MPa. As a result, the active material 5 filled in the recess 22 is compressed (pressing step).

  Next, as shown in FIG. 8 (c), the active material 5 pressed by the current collector 2 by the pressing mechanism 40 is heated by the heater 24 built in the mold member 20 to contact the mold member 20. The active material 5 in contact is heated to, for example, 80 ° C. (80 degrees Celsius). As a result, the solvent component in the active material 5 evaporates and escapes from the active material 5, and the active material 5 contracts in the direction toward the inside, and the active material filled in the recess 22. 5 separates from the surface of the recess 22. In this state, the active material 5 is dried and solidified to form an active material layer 3b having a plurality of protrusions 4b on the current collector 2 (drying step).

  Next, as illustrated in FIG. 8D, the current collector 2 having the active material layer 3 b is raised to the separation position by raising the support plate 41 from the pressing position toward the separation position by the pressing mechanism 40. Stop (separation step). Thereafter, the current collector 2 is removed from the support plate 41 by an operator or a transport robot.

  Unlike the active material layer 3 formed according to the first embodiment, the active material layer 3b formed on the current collector 2 according to this modification has a plurality of protrusions 4b that are independent from each other. Further, in the active material layer 3 according to the first embodiment, the surface of the current collector 2 is covered with the active material layer 3 even between the plurality of convex portions 4, but in this modified example, the current is collected between the plurality of convex portions 4b. The surface of the electric body 2 is exposed.

Second Embodiment
Next, the structure of 2nd Embodiment of this invention is demonstrated with reference to FIG. FIG. 9 is a view for explaining a second embodiment of the present invention, and FIG. 9A is a side view schematically showing an active material layer forming apparatus 1b according to the second embodiment. (B) is a figure which shows an operation state.

  In the first embodiment described above, the active material layer 3 is formed on the sheet-like current collector 2, but in the second embodiment, the active material layer is formed on the long strip (web-shaped) current collector 2b. 3c is formed. As shown in FIG. 9A, the active material layer forming apparatus 1b mainly includes a current collector transport mechanism 60, a conveyor mechanism 80, a mold transport mechanism 50, a supply mechanism 30b, a heater 24b, and a controller 7b.

  The current collector transport mechanism 60 rolls a driven roller 62 that rotatably supports a long belt-shaped (web-shaped) current collector 2 b wound in a roll shape, and a current collector 2 b that is drawn from the driven roller 62. And a driving roller 61 that winds in a shape. The drive roller 61 is driven to rotate in the clockwise direction in the drawing, so that the current collector 2b drawn out from the driven roller 62 is conveyed in the right direction (+ Y direction) in the drawing.

  The conveyor mechanism 80 is disposed between the drive roller 61 and the driven roller 62 of the current collector transport mechanism 60 and includes a drive roller 81, a driven roller 82, and an endless belt 83. The endless belt 83 is bridged between the driving roller 81 and the driven roller 83, and is provided at a position where the current collector 2 conveyed by the current collector conveying mechanism 60 is supported from the back surface. The driving roller 81 of the conveyor mechanism 80 is driven by the controller 7b so that the endless belt 83 moves at the same speed as the current collector 2 conveyed by the current collector conveying mechanism 60. It is driven in synchronization with.

  The mold conveying mechanism 50 includes an annular (endless belt-shaped) mold member 20b having a plurality of recesses 22b (FIG. 9B) over the outer peripheral surface thereof, a drive roller 51 over which the mold member 20b is bridged, and A driven roller 52 is provided. When the drive roller 51 is driven to rotate counterclockwise in the drawing, the driven roller 52 and the mold member 20b are also rotated counterclockwise in conjunction with this. The drive roller 51 of the mold transport mechanism 50 is driven by the controller 7b so that the mold member 20b moves at the same speed as the current collector 2 transported by the current collector transport mechanism 60. It is driven in synchronization with 61. In addition, the height position of the mold member 20 b is a position where the mold member 20 b is supported by the endless belt 83 of the conveyor mechanism 80 at the position facing the current collector 2 b conveyed by the current collector conveyance mechanism 60. It is set at a position where the surface (upper surface) of the electric body 2 b is pressed through the active material 5. The ratio of the depth dimension to the width dimension of the recess 22b of the mold member 20b is 1/2 or more, as in the first embodiment.

  The supply mechanism 30b includes a nozzle 31b. The nozzle 31b is disposed at a position facing the outer peripheral surface of the mold member 20b on the upstream side in the rotation direction of the mold member 20b rather than the position where the mold member 20b faces the surface of the current collector 2. The nozzle 31b extends in the X direction, and its lower portion is tapered. A discharge port (not shown) is formed at the tip (right end in the drawing) of the nozzle 31b, and this discharge port is a slit-like discharge port extending in the X direction. The nozzle 31b is connected to a liquid feed / discharge mechanism such as a pump and a pipe (not shown) for sending an active material to the nozzle 31b and discharging it from the discharge port.

  The heater 24b is disposed at a position facing the back surface of the mold member 20b at a position where the mold member 20b faces the current collector 2, and heats the mold member 20b at this position.

  In the second embodiment, the current collector 2 and the active material 5 are, for example, a negative electrode current collector or a positive electrode current collector used in a lithium ion secondary battery, and a paste-like material, as in the first embodiment. It is a negative electrode active material or a positive electrode active material.

  Next, the operation of the second embodiment will be described. First, the controller 7b drives the drive roller 61 of the current collector transport mechanism 60, the drive roller 81 of the conveyor mechanism 80, and the drive roller 51 of the mold transport mechanism 50 in synchronization with each other. Moreover, the control part 7b discharges toward the outer peripheral surface of the type | mold member 20b which moves the active material 5 from the nozzle 31b of the supply mechanism 30b.

  By continuously discharging the paste-like active material 5 from the discharge port of the nozzle 31b toward the outer peripheral surface of the mold member 20b, the active material 5 is filled in the plurality of recesses 22b and on the plurality of protrusions 23b. In addition, the active material 5 is continuously supplied, and a layer of the active material 5 is formed in a region on the outer peripheral surface of the mold member 20 (application process).

  The active material 5 supplied onto the mold member 20b includes the current collector 2b supported by the endless belt 83 and the mold member, as shown on the left side of FIG. 9B, as the mold member 20b rotates. It is sandwiched between 20b and pressed (pressing step).

  The current collector 2b, the active material 5 and the mold member 20b, which are pressed and stacked, pass below the heater 24b as the current collector 2 and the mold member 20b move. The mold member 20b passing under the heater 24b is heated by the heater 24. As a result, the active material 5 in contact with the mold member 20b is also heated. When the active material 5 is heated in this way, the solvent component in the active material 5 is vaporized and escapes from the active material 5. As a result, as shown on the right side of FIG. 9B, the active material 5 contracts in the direction toward the inside, and the active material 5 filled in the recess 22 is separated from the surface of the recess 22. In this state, the active material 5 is dried and solidified to form an uneven active material layer 3c having a plurality of protrusions 4c on the current collector 2 (drying step). Note that the shrinkage ratio of the active material 5 in the drying process is in the range of 10% to 50% as in the first embodiment, and the height relative to the width dimension of the protrusion 4c in the active material layer 3c after the drying process. The ratio of dimensions is 1/2 or more as in the first embodiment.

  The mold member 20b that has passed below the heater 24b moves upward with the rotation thereof. As a result, the mold member 20b is separated from the active material layer 3c formed on the current collector 20 that has passed under the heater 24b (a separation step).

  In the coating process of the second embodiment, the active material may be intermittently discharged from the nozzle 31b toward the plurality of recesses 20b as in the modification of the first embodiment. In the case of this modification, after the pressing step, the drying step, and the separation step, an active material layer having a plurality of independent protrusions is formed on the current collector 2b.

  The present invention is not limited to the above-described embodiment, and various modifications other than those described above can be made without departing from the spirit of the present invention. For example, the mold member 20 according to the first embodiment and the mold member 20b according to the second embodiment are formed with recesses 22 and 22b having a rectangular parallelepiped shape. It may be hemispherical or semicylindrical.

  In the first embodiment and the modification thereof, the nozzle 31 is horizontally moved with respect to the fixedly arranged mold member 20, but the mold member may be horizontally moved with respect to the fixedly arranged nozzle. . Further, although the current collector 2 is raised and lowered with respect to the fixedly arranged mold member 20, a structure in which the mold member is raised and lowered with respect to the fixedly arranged current collector may be used.

  Instead of the heater as the heating source, a configuration in which a medium such as a heated liquid or gas is allowed to flow in the mold member may be used. Moreover, the structure which heats the active material material currently pressed rather than heating the mold member and heating it may be sufficient.

  Further, the current collector and the active material exemplified in the above embodiment are examples, and the present invention is not limited thereto, and other materials used as a constituent material of the electrode for the lithium ion secondary battery are used. Even in the case of manufacturing an electrode for a lithium ion battery, the forming apparatus and method of the present invention can be suitably applied. Further, the present invention can be applied not only to the lithium ion secondary battery but also to the manufacture of chemical battery electrodes using other materials.

DESCRIPTION OF SYMBOLS 1a, 1b Active material layer formation apparatus 2, 2b Current collector 3, 3b, 3c Active material layer 4, 4b, 4c Convex part 5 Active material material 7, 7b Control part 20, 20b Mold member 22, 22b Concave part 24, 24b Heater 30 Supply mechanism 40 Press mechanism 50 Type transport mechanism 60 Current collector transport mechanism 80 Conveyor mechanism

Claims (10)

A mold member having a plurality of recesses on its surface;
Supply means for supplying active material into at least a plurality of recesses of the mold member;
A supporting means for supporting the current collector;
A pressing means for pressing the current collector supported by the support means against the active material supplied to the mold member by the supply means;
Heating means for heating the active material being pressed by the pressing means;
An apparatus for forming an active material layer, comprising: In the active material layer forming apparatus according to claim 1,
The mold member is a plate-like member having a plurality of recesses on the surface thereof,
The supply means includes a nozzle that discharges the active material toward the surface of the mold member, and a moving means that relatively moves the nozzle along the surface of the mold member.
The pressing means includes a pressing position for pressing the current collector supported by the supporting means against the active material supplied to the mold member by the supplying means, and a separation position positioned in a direction away from the mold member from the pressing position. An active material layer forming apparatus, characterized in that it has a displacement means for relatively displacing the current collector. The apparatus for forming an active material layer according to claim 2,
An apparatus for forming an active material layer, characterized in that the heating means heats the mold member and heats the active material pressed by the pressing means. The apparatus for forming an active material layer according to claim 3,
An apparatus for forming an active material layer, wherein the heating means has a heating source built in the mold member. In the active material layer forming apparatus according to claim 1,
The mold member is an annular member having a plurality of recesses on its outer surface,
The supply means has a nozzle that discharges the active material toward the outer surface of the mold member,
The pressing means rotates the mold member so that the outer surface of the mold member is displaced in the order of the position facing the nozzle, the position where the current collector is pressed against the active material, and the position away from the current collector. An apparatus for forming an active material layer, characterized by comprising means. In the active material layer forming apparatus according to claim 5,
An apparatus for forming an active material layer, characterized in that the heating means heats the mold member and heats the active material pressed by the pressing means. In the active material layer forming apparatus according to any one of claims 1 to 6,
An apparatus for forming an active material layer, wherein the supply means continuously supplies an active material toward a region including a plurality of concave portions of the mold member. In the active material layer forming apparatus according to any one of claims 1 to 6,
An apparatus for forming an active material layer, wherein the supplying means supplies the active material intermittently toward each of the plurality of recesses of the mold member. A supply step of supplying an active material into at least a plurality of recesses of the mold member;
A pressing step of pressing the current collector against the active material supplied to the mold member by the supplying step;
Heating the active material being pressed in the pressing step to dry and shrink the active material, and
A separation step of separating the current collector including the active material layer having a plurality of convex portions from the mold member after the heating step;
A method for forming an active material layer, comprising: In the formation method of the active material layer according to claim 9,
The ratio of the depth to the width of the concave portion of the mold member is 1/2 or more, and the contraction ratio of the width dimension and the height dimension of the convex portion of the active material material by the heating process is within a range of 10% to 50%, respectively. A method for forming an active material layer, comprising:

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