Electrode manufacturing apparatus

Abstract

To provide an electrode manufacturing apparatus capable of suppressing warpage of an electrode.SOLUTION: An electrode manufacturing apparatus includes: a transport section which transports a workpiece in one direction, the workpiece including a substrate and an electrode slurry applied onto the substrate or an electrode layer formed by drying the electrode slurry; a drying section which dries the electrode slurry or the electrode layer; and a warpage correcting section which drives plate members at the same speed of the transportation speed of the workpiece to synchronize the plate member with the workpiece, and sandwiches the workpiece passing the drying section by the plate members.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] Various techniques have been proposed regarding electrode manufacturing apparatuses such as that disclosed in Patent Document 1. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-145034 A Summary of the Invention [Problem to be solved by the invention]

[0004] Pressing after the electrode slurry is applied and dried causes the electrodes to warp. This warping can be corrected slightly by heating the electrodes while transporting them on a reel-to-reel basis. However, with conventional technology, the only force that stretches the electrodes when heated is tension, so the ability to correct the warping is weak.

[0005] The present disclosure has been made in consideration of the above-mentioned circumstances, and has a main object to provide an electrode manufacturing apparatus that can suppress warping of the electrode. [Means for solving the problem]

[0006] That is, the present disclosure includes the following aspects. <1> An apparatus for manufacturing an electrode, comprising: A conveying unit that conveys a workpiece including a substrate and an electrode slurry applied to the substrate or an electrode layer obtained by drying the electrode slurry in one direction; a drying section for drying the electrode slurry or the electrode layer; and a warp correction section that drives a plate member at a speed equal to the transport speed of the workpiece, synchronizes the plate member and the workpiece, and clamps the workpiece that has passed through the drying section with the plate member. Effect of the Invention

[0007] The electrode manufacturing apparatus of the present disclosure can suppress warping of the electrode. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram showing an example of a production apparatus according to the present disclosure. [Diagram 2] FIG. 2 is a schematic diagram showing another example of the production apparatus of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, embodiments of the present disclosure will be described. Note that matters other than those specifically mentioned in this specification and necessary for implementing the present disclosure (for example, the general configuration and manufacturing process of an electrode manufacturing device that does not characterize the present disclosure) can be understood as design matters of a person skilled in the art based on the prior art in the field. The present disclosure can be implemented based on the contents disclosed in this specification and the technical common sense in the field. Furthermore, the dimensional relationships (length, width, thickness, etc.) in the drawings do not reflect the actual dimensional relationships.

[0010] The present disclosure provides an electrode manufacturing apparatus, comprising: A conveying unit that conveys a workpiece including a substrate and an electrode slurry applied to the substrate or an electrode layer obtained by drying the electrode slurry in one direction; a drying section for drying the electrode slurry or the electrode layer; The present invention provides an electrode manufacturing apparatus having a warp correction section that drives a plate member at a speed equal to the transport speed of the workpiece, synchronizes the plate member and the workpiece, and clamps the workpiece that has passed through the drying section with the plate member.

[0011] According to the present disclosure, the electrodes can be heated at high speed by radiation while being transported reel-to-reel, which is necessary for warping correction, and the electrodes can be sandwiched between plate members without being stopped during heating, making it possible to correct warping faster and without damage than if the electrodes were to be corrected one by one using a sheet of paper.

[0012] The electrode manufacturing apparatus of the present disclosure includes a transport unit, a drying unit, and a warpage correction unit.

[0013] The conveying unit conveys, in one direction, a workpiece including a substrate and an electrode slurry applied to the substrate or an electrode layer formed by drying the electrode slurry. The conveying speed of the conveying section may be, for example, 30 m / min or more.

[0014] The substrate may be a current collector or the like. The current collector may be a negative electrode current collector, a positive electrode current collector, a bipolar current collector, or the like. Examples of materials for the current collector include metals such as aluminum, copper, SUS, and nickel. The thickness of the current collector is, for example, 0.1 μm or more and 100 μm or less. The shape of the current collector may be a sheet or the like.

[0015] The electrode manufacturing apparatus of the present disclosure may have a coating unit that applies an electrode slurry to a substrate. The electrode slurry is applied to a first surface of a substrate. The electrode slurry may be applied only to the first surface of a current collector, or may be applied to the first surface of the current collector and a second surface opposite to the first surface. The electrode slurry can be prepared by mixing electrode materials including an active material, a binder, a conductive material, an electrolyte, a thickener, and the like, together with a solvent. The electrode slurry may be a positive electrode slurry or a negative electrode slurry. The electrode slurry may contain water of about 10,000 ppm or less.

[0016] The active material may be a positive electrode active material. Examples of the positive electrode active material include oxide active materials. Examples of the oxide active material include LiCoO2, LiMnO2, LiNiO2, LiVO2, and LiNi 1 / 3 Co1 / 3 Mn 1 / 3 O2, etc., rock salt layered active materials, LiMn2O4, Li(Ni 0.5 Mn 1.5 )O4 and the like; and olivine type active materials such as LiFePO4, LiMnPO4, LiNiPO4, and LiCuPO4.

[0017] The active material may be a negative electrode active material. Examples of the negative electrode active material include carbon active materials, oxide active materials, and metal active materials. Examples of the carbon active material include mesocarbon microbeads (MCMB), highly oriented graphite (HOPG), hard carbon, and soft carbon. Examples of the oxide active material include Nb2O5, Li4Ti5O 12 and SiO. Examples of the metal active material include In, Al, Si, Sn, and the like.

[0018] Examples of the binder include fluorine-containing binders such as polyvinylidene fluoride (PVDF) and polytetrafluoroethylene (PTFE), rubber-based binders such as butadiene rubber, and acrylic-based binders.

[0019] Examples of conductive materials include carbon materials, metal particles, conductive polymers, etc. Examples of carbon materials include particulate carbon materials such as acetylene black (AB) and ketjen black (KB), and fibrous carbon materials such as carbon fibers, carbon nanotubes (CNT), and carbon nanofibers (CNF).

[0020] Examples of thickeners include polysaccharides such as carboxymethylcellulose and methylcellulose.

[0021] Examples of the electrolyte include solid electrolytes such as sulfide solid electrolytes and oxide solid electrolytes. Examples of the sulfide solid electrolyte include solid electrolytes containing Li, X (X is at least one of P, As, Sb, Si, Ge, Sn, B, Al, Ga, and In), and S. The sulfide solid electrolyte may further contain at least one of O and halogen elements. Examples of the halogen elements include F, Cl, Br, and I.

[0022] Examples of oxide solid electrolytes include Li2O-B2O3-P2O5, Li2O-SiO2, Li2O-B2O3, Li 1.3 Al 0.3 Ti 0.7 (PO4)3, Li5La3Ta2O 12 , Li7La3Zr2O 12 , Li6BaLa2Ta2O 12 , Li 3.6 S 0.6 P 0.4 O4, Li4SiO4, Li3PO4, Li3PO 4-3 / 2x N x (x≦1).

[0023] Examples of the solvent include aqueous solvents and organic solvents. The aqueous solvent means water or a mixed solvent containing water and a polar organic solvent. For example, an appropriate dispersion medium can be selected depending on the types of active material, binder, etc. As the aqueous solvent, water is preferably used because of its ease of handling. Examples of polar organic solvents that can be used in the mixed solvent include alcohols such as methanol, ethanol, and isopropyl alcohol, ketones such as acetone, and ethers such as tetrahydrofuran. An example of the organic solvent is N-methyl-2-pyrrolidone (NMP).

[0024] The electrode manufacturing apparatus of the present disclosure may have a press section that pressurizes the work before drying the work in the drying section.

[0025] The drying section dries the electrode slurry or an electrode layer obtained by drying the electrode slurry. The drying section may be a conventionally known device capable of drying the electrode slurry or the electrode layer, such as a hot air device, a laser device, or an IR (infrared) device, and two or more of these may be used in combination. The drying section may completely dry the electrode slurry or the electrode layer until the moisture content is several hundred ppm or less, for example, 500 ppm or less. The drying time of the electrode slurry or the electrode layer in the drying section can be appropriately set depending on the drying temperature of the electrode slurry or the electrode layer, etc. The drying section may supply hot air having a dew point of −20° C. or more and 25° C. or less and a temperature of 65° C. or more to the electrode slurry or the electrode layer. The drying section may dry the electrode slurry or the electrode layer using a laser, IR, or the like under conditions of a temperature of 100° C. to 200° C. and a time of 10 to 15 seconds. The electrode slurry is dried in the drying section to form an electrode layer, and the electrode layer is bone-dried in the drying section until the moisture content is reduced to several hundred ppm or less, thereby obtaining the electrode of the present disclosure that includes a current collector as a substrate and a bone-dried electrode layer.

[0026] The warp correction unit drives a plate member at a speed equal to the conveying speed of the workpiece, and synchronizes the plate member and the workpiece (constant speed synchronization) to sandwich the workpiece that has passed through the drying unit with the plate member. In other words, the warp correction unit periodically drives the plate member at a speed equal to the conveying speed so that the conveyed workpiece is sandwiched between the plate member. The plate members may be two flat plates, two belts, or the like. The plate member may be made of an insulating material such as resin. The plate member may be heatable. The plate member may be heated to a temperature of 120° C. or higher. The plate member may be a rubber heater or the like to prevent foreign matter from entering the battery. The time for clamping with the plate members may be 1 second or more. The warp correction section drives the plate member at a speed equal to the workpiece transport speed, synchronizing the plate member and the workpiece, and pressing the workpiece that has passed through the drying section with the plate member, thereby quickly correcting the warp in the electrode.

[0027] FIG. 1 is a schematic diagram showing an example of a production apparatus according to the present disclosure. The manufacturing apparatus shown in Fig. 1 includes a conveying section 2 that conveys in one direction a work 1 including a substrate and an electrode slurry applied to the substrate or an electrode layer obtained by drying the electrode slurry, a drying section 10 having a laser device 11 and a hot air device 12, and a warpage correction section 20 that drives a heated flat plate (rubber heater) 21 in synchronization with the work 1 at a speed equal to the conveying speed of the work 1 and sandwiches the dried work 1 between the two heated flat plates 21. The work 1 is conveyed in the conveying direction by the conveying section 2, heated by the laser device 11, hot air 50 is supplied by the hot air device 12, and the work 1 is sandwiched between the two heated flat plates 21, so that the warpage of the electrode is corrected. In the drying section 10, an IR device may be used instead of the laser device 11, or these may be used in combination.

[0028] FIG. 2 is a schematic diagram showing another example of the production apparatus of the present disclosure. The manufacturing apparatus shown in FIG. 2 has the same configuration as that of the manufacturing apparatus shown in FIG. 1, except that the warp correction unit 20 has two heated belts 22 instead of the two heated flat plates 21.

[0029] The electrode obtained by the manufacturing apparatus of the present disclosure includes an electrode layer and a current collector. The electrode layer may be a positive electrode layer or a negative electrode layer. The electrode layer may contain one of a positive electrode active material and a negative electrode active material, and may further contain a binder, a conductive material, an electrolyte, etc. These materials are as described above. The current collector may be a negative electrode current collector, a positive electrode current collector, a bipolar current collector, etc. The material of the current collector, the thickness of the current collector, and the shape of the current collector are as described above.

[0030] The electrodes of the present disclosure are typically used in the manufacture of batteries. The electrodes may be positive or negative electrodes. The type of battery in which the electrode is used is not particularly limited, and may be, for example, a lithium ion secondary battery. The battery may be a liquid battery using an electrolytic solution as an electrolyte, or a solid battery using a solid electrolyte as an electrolyte. Examples of uses of the battery include power sources for vehicles such as hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), electric vehicles (BEVs), gasoline automobiles, and diesel automobiles. In particular, the battery may be used as a driving power source for hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), or electric vehicles (BEVs). The battery may also be used as a power source for moving objects other than vehicles (for example, railways, ships, and aircraft), and may be used as a power source for electrical products such as information processing devices. EXAMPLES

[0031] (Examples 1 to 4, Comparative Examples 1 to 3) An electrode slurry was applied to one side of a current collector, dried, and pressed to prepare a workpiece, and in each example and comparative example, the electrode warpage was corrected and the amount of electrode warpage was measured using the device conditions shown in Table 1. The workpiece was heated in the drying section at an ultimate temperature of 120°C for a heating time of 10 seconds, and the workpiece was sandwiched between two flat plates in the warpage correction section for a holding time of 1 second and a temperature of the heated flat plates of 120°C. The results are shown in Table 1.

[0032] [Table 1]

[0033] As shown in Table 1, it has been demonstrated that the electrodes obtained by the manufacturing apparatus of the present disclosure can reduce warping. [Explanation of symbols]

[0034] 1. Work 2.Transportation section 10.Drying section 11. Laser equipment 12.Hot air device 20. Warping correction section 21. Heated plate 22. Heated belt 50. Hot air

Claims

[Claim 1] An apparatus for manufacturing an electrode, comprising: A conveying unit that conveys a workpiece including a substrate and an electrode slurry applied to the substrate or an electrode layer obtained by drying the electrode slurry in one direction; a drying section for drying the electrode slurry or the electrode layer; and a warp correction section that drives a plate member at a speed equal to the transport speed of the workpiece, synchronizes the plate member and the workpiece, and clamps the workpiece that has passed through the drying section with the plate member.

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