Method for manufacturing battery material

Abstract

To provide a battery material manufacturing device for continuously and efficiently manufacturing a battery material while suppressing generation of a void.SOLUTION: A battery material manufacturing device 100 includes: a drawing device 160; a monitoring device 180; and a control device 200. The drawing device 160 receives a sheet-like molded product obtained by kneading a base material and a filler at first conveying speed from a sheet molding device 140 for continuously sending out the molded product, and sends out the molded product at second conveying speed higher than the first conveying speed to reduce a thickness of the molded product. The monitoring device 180 generates monitoring data by monitoring at least one of a thickness, tension, and strain applied to the molded product at a plurality of different positions in order to determine drawing conditions under which no void is generated in the molded product, and outputs the monitoring data to the control device 200 that controls the drawing conditions.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an apparatus for manufacturing a battery material, a system for manufacturing a battery material, and a method for manufacturing a battery material. [Background technology]

[0002] In recent years, the demand for batteries has increased in various fields, and the development of next-generation batteries is progressing. For example, a technology to replace metal current collectors with resin and a technology to impregnate a specific polymer with an electrolyte have been proposed as next-generation batteries.

[0003] For example, Patent Document 1 discloses a resin current collector for lithium ion batteries having a conductive resin layer containing a matrix resin, a conductive filler, and a dispersant for the conductive filler.

[0004] Patent Document 2 discloses a resin current collector for a positive electrode in which a conductive filler is dispersed in a matrix resin containing a specific polymer.

[0005] Patent Document 3 discloses a negative electrode for a lithium ion battery having a current collector and a negative electrode composition layer disposed on the surface of the current collector, and a method for producing the same. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent Publication No. 2021-068587 [Patent Document 2] JP 2021-118046 A [Patent Document 3] JP 2021-125337 A Summary of the Invention [Problem to be solved by the invention]

[0007] However, the inventions of the above-mentioned patent documents do not necessarily provide a means for mass-producing lithium-ion batteries or battery materials. In addition, when manufacturing a sheet-shaped battery material containing a filler, there is a risk of voids being generated between the substrate and the filler. The voids cause deterioration of the quality of the battery.

[0008] The present disclosure has been made to solve such problems, and provides a battery material manufacturing apparatus and the like that continuously and efficiently manufactures battery materials while suppressing the occurrence of voids. [Means for solving the problem]

[0009] The battery material manufacturing apparatus according to the present disclosure includes a stretching device and a monitoring device. The stretching device receives a sheet-shaped molded product obtained by kneading a base material and a filler from a sheet molding device that continuously delivers the product at a first conveying speed and delivers the product at a second conveying speed faster than the first conveying speed, thereby reducing the thickness of the molded product. The monitoring device monitors at least any of the tension, strain, and thickness applied to the molded product at multiple different positions in order to determine a stretching condition that does not cause voids in the molded product, generates monitoring data, and outputs the monitoring data to a control device that controls the stretching conditions.

[0010] In the battery material manufacturing method according to the present disclosure, a battery material manufacturing apparatus executes the following processes. The battery material manufacturing apparatus receives a molded product at a first conveying speed from a sheet molding apparatus that continuously delivers sheet-like molded products obtained by kneading a base material and a filler. The battery material manufacturing apparatus stretches the molded product so that the thickness of the molded product becomes thinner by delivering the molded product at a second conveying speed. The battery material manufacturing apparatus acquires monitoring data from a monitoring device that monitors at least one of the tension, strain, and thickness applied to the molded product at a plurality of different positions. The battery material manufacturing apparatus determines a stretching condition under which no voids are generated in the molded product according to the monitoring data. The battery material manufacturing apparatus controls the stretching device based on the stretching conditions. Effect of the Invention

[0011] According to the present disclosure, it is possible to provide a battery material manufacturing apparatus and the like that can continuously and efficiently manufacture battery materials while suppressing the occurrence of voids. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a configuration diagram of a battery according to an embodiment. [Diagram 2] 1 is an overall configuration diagram of a battery material manufacturing system according to an embodiment. [Diagram 3] FIG. 1 is a block diagram of a battery material manufacturing system. [Figure 4] FIG. 2 is a diagram for explaining the state of a molded product. [Diagram 5] 1 is a first graph showing the relationship between distortion and tension of a molded product. [Figure 6] 1 is a second graph showing the relationship between distortion and tension of a molded product. [Figure 7] 11 is a third graph showing the relationship between distortion and tension of a molded product. [Figure 8] 1 is a flowchart of a method for manufacturing a battery material. [Figure 9] 4 is a flowchart showing a method for controlling the stretching device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The present invention will be described below through the embodiments of the invention, but the invention according to the claims is not limited to the following embodiments. In addition, not all of the configurations described in the embodiments are necessarily essential as means for solving the problems. For clarity of explanation, the following description and drawings are omitted and simplified as appropriate. In each drawing, the same elements are given the same reference numerals, and duplicate explanations are omitted as necessary.

[0014] <Embodiment> Hereinafter, a battery material manufacturing system according to an embodiment will be described with reference to the drawings. The battery material manufacturing system according to the present embodiment manufactures materials for manufacturing a predetermined battery. The predetermined battery is, for example, a lithium ion battery, which is a type of semi-solid battery.

[0015] Fig. 1 is a configuration diagram of a battery according to the present embodiment. The battery P100 shown in Fig. 1 is made up of, from the top, a current collector P10, a positive electrode layer P20, a separator P30, a negative electrode layer P40, and another current collector P10 stacked in layers.

[0016] The current collector P10 is formed by stacking, in order from the top, a negative electrode current collector P11, a current collecting substrate P12, and a positive electrode current collector P13 in a layered manner.

[0017] The negative electrode current collector P11 mainly comprises a matrix resin and a conductive filler dispersed in the matrix resin. The matrix resin is, for example, PP (polypropylene), PMMA (acrylic resin), or PVC (polyvinyl chloride). The conductive filler is, for example, a powder or granular material having electrical conductivity, such as titanium powder, nickel powder, aluminum powder, or carbon black. The conductive filler is not limited to the above, and may be, for example, a fibrous material having electrical conductivity, such as carbon nanotubes, graphene, or metal nanowires. The negative electrode current collector P11 may contain a dispersant. The dispersant is not particularly limited in terms of ingredients or composition, as long as it is a resin that can be molded into a film or sheet. The dispersant may be, for example, a copolymer of PP and PE (polyethylene).

[0018] Of the above-mentioned configurations, the conductive filler, in the form of powder, preferably has a particle diameter of 1 micrometer or more and 500 micrometers or less, and a mass percentage of 5% or more and 85% or less, and more preferably a mass percentage of 20% or more and 80% or less. The conductive filler may form secondary particles. Secondary particles are aggregated particles formed by agglomeration (clustering) of primary particles of 1 nanometer or more and less than 10 micrometers. The shape of the secondary particles does not necessarily have to be spherical or a lump-like shape close to a sphere, and may be a shape connected like beads, or may have a branched portion like a tree.

[0019] Furthermore, when the conductive filler is in a fibrous body, the fiber diameter is, for example, 1 nanometer or more and 500 nanometers or less, the fiber length is 1 micrometer or more and 500 micrometers or less, and the mass percentage is preferably 5 percent or more and 85 percent or less, and more preferably 20 percent or more and 80 percent or less.

[0020] The particle size can be suitably measured using a particle size distribution measuring device that utilizes the diffraction and scattering of laser light. That is, the particle size may be the average of the particle size distribution in the measurement using the particle size distribution measuring device. The fiber diameter and fiber length can also be measured using the above-mentioned particle size distribution measuring device. In this case, since the particle size distribution pattern obtained by the measurement has multiple peaks, the peak on the small diameter side may be the fiber diameter, and the peak on the large diameter side may be the fiber length.

[0021] The current collecting substrate P12 is provided between the negative electrode current collector P11 and the positive electrode current collector P13. The current collecting substrate P12 contains, for example, PP, a copolymer of PP and PE, carbon black, graphite, or the like.

[0022] The positive electrode current collector P13 mainly comprises a matrix resin and a conductive filler dispersed in the matrix resin. The matrix resin is, for example, PP. The conductive filler is, for example, carbon powder and carbon fiber. The carbon powder is not limited in form as long as it is a powder material mainly composed of carbon. That is, the carbon powder may be graphite or carbon black. The carbon fiber is not limited in form as long as it is a fibrous material mainly composed of carbon. That is, the carbon fiber may be carbon nanotubes or graphene. The positive electrode current collector P13 may also contain a dispersant. The dispersant is, for example, a copolymer of PP and PE.

[0023] Of the above-mentioned configurations, the conductive filler, in the form of powder, preferably has a particle diameter of 1 micrometer or more and 500 micrometers or less, and a mass percentage of 5% or more and 85% or less, and more preferably a mass percentage of 20% or more and 80% or less. The conductive filler may form secondary particles. Secondary particles are aggregated particles formed by agglomeration (clustering) of primary particles of 1 nanometer or more and less than 10 micrometers. The shape of the secondary particles does not necessarily have to be spherical or a lump-like shape close to a sphere, and may be a shape connected like beads, or may have a branched portion like a tree.

[0024] The conductive filler, in the fibrous body, has, for example, a fiber diameter of 1 nanometer or more and 500 nanometers or less, a fiber length of 1 micrometer or more and 500 micrometers or less, and a mass percentage of 5% or more and 85% or less, and more preferably a mass percentage of 20% or more and 80% or less. The positive electrode side current collector P10 has a negative electrode current collector P11 disposed on the opposite side, and a positive electrode current collector P13 contacts the positive electrode layer P20.

[0025] The positive electrode layer P20 is provided between the positive electrode current collector P13 and the separator P30. The positive electrode layer P20 includes a gel-like polymer compound, a positive electrode active material, and a conductive filler. The gel-like polymer compound may be a resin having electrical conductivity.

[0026] The separator P30 is provided between the positive electrode layer P20 and the negative electrode layer P40. The separator P30 is, for example, a polyolefin (PO)-based microporous film.

[0027] The negative electrode layer P40 is provided between the separator P30 and the negative electrode current collector P11. The negative electrode layer P40 includes a gel-like polymer compound, negative electrode active material particles, and a conductive filler. The gel-like polymer compound may be a resin having electrical conductivity.

[0028] A current collector P10 is disposed on the side opposite to where the negative electrode layer P40 is in contact with the separator P30. In the negative electrode side current collector P10, a negative electrode current collector P11 is in contact with the negative electrode layer P40, and a positive electrode current collector P13 is disposed on the opposite side.

[0029] Although the configuration of the battery P100 according to the present embodiment has been described above, the battery P100 may have a structural material for maintaining the shape of the battery P100 in addition to the above-mentioned configuration. The battery P100 may also be configured such that a plurality of batteries P100 are stacked in layers.

[0030] In the above-mentioned battery P100, for example, the current collector P10 can be manufactured as follows. That is, first, the manufacturer forms the current collecting substrate P12 into a film. Next, the manufacturer applies the negative electrode current collector P11 to one surface of the formed current collecting substrate P12 and dries it. Furthermore, the manufacturer applies the positive electrode current collector P13 to the opposite surface of the current collecting substrate P12 and dries it. The battery material manufacturing system according to this embodiment manufactures, for example, this current collecting substrate P12.

[0031] Next, a battery material manufacturing system will be described with reference to FIG. 2. FIG. 2 is an overall configuration diagram of a battery material manufacturing system 10 according to an embodiment. The battery material manufacturing system 10 shown in FIG. 2 is a schematic diagram of each configuration for easy understanding. The battery material manufacturing system 10 shown in the figure continuously manufactures, for example, the above-mentioned current collecting substrate P12. The battery material manufacturing system 10 has a battery material manufacturing apparatus 100 as a main component. In addition to the battery material manufacturing apparatus 100, the battery material manufacturing system 10 also has a raw material input section 110, an extrusion device 120, a pump section 130, a sheet forming device 140, a cast roller 150, a rolling system 190, and a winding device 170.

[0032] (Battery material manufacturing equipment) The battery material manufacturing apparatus 100 receives a sheet-shaped molded product obtained by kneading a base material and a filler, and stretches the sheet to manufacture a battery material. The battery material manufacturing apparatus 100 mainly includes a stretching device 160, a monitoring device 180, and a control device 200.

[0033] The stretching device 160 receives the sheet-like molded product delivered by the sheet forming device 140, stretches the received molded product, and delivers the molded product with a reduced thickness due to the stretching. The molded product received by the stretching device 160 is a sheet-like molded product obtained by kneading a base material and a filler, which is continuously delivered by the sheet forming device 140. At this time, the stretching device 160 is controlled so that the conveying speed, which is the speed at which the molded product is conveyed, is faster on the downstream side than on the upstream side. For example, the stretching device 160 receives the molded product at a first conveying speed and delivers it at a second conveying speed faster than the first conveying speed, thereby stretching the molded product and reducing its thickness. The first conveying speed and the second conveying speed of the stretching device 160 are controlled by the control device 200.

[0034] The monitoring device 180 monitors at least any of the tension, distortion, and thickness applied to the molded product at a plurality of different positions in order to determine the stretching conditions under which no voids are generated in the molded product. The monitoring device 180 also generates monitoring data related to at least any of the tension, distortion, and thickness applied to the molded product, and outputs the generated monitoring data to the control device 200. The monitoring device 180 may have, for example, a tension sensor that measures the tension applied to the molded product. The monitoring device 180 may also have a distortion sensor that measures the distortion of the molded product. The distortion of the molded product may be calculated from the difference in thickness between the upstream side and the downstream side. The distortion of the molded product may also be calculated from the difference in thickness between the upstream side and the downstream side and the dimension extended in the conveying direction. In this case, the monitoring device 180 may measure the thickness using an optical dimension measuring device. The monitoring device 180 may also calculate the dimension extended by the molded product from the difference in conveying speed between the upstream side and the downstream side. The monitoring device 180 may have an image sensor that monitors the dimensional change by photographing the appearance of the molded product.

[0035] The monitoring device 180 may include an optical inspection device that determines the dispersion state of the filler in the molded product M2. The means for determining the dispersion state of the filler is not particularly limited, and may include, for example, a means for detecting the intensity of transmitted light when light having a single or multiple wavelengths is transmitted through the molded product M2. The means for determining the dispersion state of the filler may include, for example, a means for detecting a specific wavelength among the scattered light generated when light having a single or multiple wavelengths is irradiated onto the molded product M2. The means for determining the dispersion state of the filler may include, for example, a means for visually imaging the filler dispersion state by detecting at least one of the transmitted light, reflected light, and scattered light generated when light having a single or multiple wavelengths is irradiated onto the molded product M2. In this case, the control device 200 determines the stretching conditions at least based on the filler dispersion states in multiple different regions of the molded product M2. As a result, the battery material manufacturing system 10 can determine the stretching conditions while suitably determining whether or not voids are generated in the molded product in the stretching section.

[0036] The monitoring device 180 may include a temperature inspection device that determines the temperature distribution of the molded article M2. The means for determining the temperature distribution of the molded article M2 is not particularly limited, and may include, for example, a means for detecting the intensity of far-infrared light emitted from the molded article M2. In this case, the control device 200 determines the stretching conditions based at least on the temperature distribution state in multiple different regions of the molded article M2.

[0037] The control device 200 determines the stretching conditions under which no voids will occur in the molded product according to the output of the monitoring device 180, and controls the stretching device within a range under which no voids will occur in the molded product based on the determined stretching conditions. In this way, the control device 200 controls the stretching device 160 so that no voids will occur in the state of the molded product. Also, the stretching device 160 can stretch the molded product while suppressing the occurrence of voids.

[0038] In the battery material manufacturing apparatus 100, the stretching device 160 may have a plurality of stretching sections. The stretching device 160 shown in FIG.

[0039] In the stretching device 160, the first stretching section 161 receives the molded product M2 at a conveying speed V5 and delivers the molded product at a conveying speed V6. The second stretching section 162 receives the molded product M2 delivered by the first stretching section 161 and delivers the molded product at a conveying speed V7. At this time, the conveying speed V6 is faster than the conveying speed V5. Furthermore, the conveying speed V7 is faster than the conveying speed V6. In this case, the control device 200 controls the conveying speeds V5, V6, and V7 in accordance with the output of the monitoring device 180 under conditions where no voids are generated in the molded product.

[0040] The stretching device 160 shown in FIG. 2 has two stretching parts. However, the stretching device 160 may have three or more stretching parts. With this configuration, the battery material manufacturing apparatus 100 can perform stretching multiple times to an extent that no voids are generated. This allows the battery material manufacturing apparatus 100 to manufacture a molded product of a desired thickness without generating voids.

[0041] 2, the monitoring device 180 has a first sensor 181 provided in an upstream region of the first stretching section 161, a second sensor 182 provided in an intermediate region between the first stretching section 161 and the second stretching section 162, and a third sensor 183 provided in a downstream region of the second stretching section 162. In this case, the control device 200 controls the stretching device 160 according to the outputs of the first sensor 181, the second sensor 182, and the third sensor 183. This allows the battery material manufacturing device 100 to perform multiple stretching operations in multiple stretching sections under stretching conditions that do not cause voids in the molded product.

[0042] The stretching device 160 has stretching rolls that sandwich the front and back of the molded product and stretch it. In this case, the control device 200 controls the rotation speed of the stretching rolls. This allows the stretching device 160 to suitably stretch the molded product. The stretching device 160 may also have guide rollers that guide the molded product.

[0043] In the battery material manufacturing apparatus 100, the monitoring device 180 may have a sensor that measures the tension applied to the molded product. More specifically, the tension sensor measures the force in the pulling direction of the molded product M2 in the stretching device 160 as the tension. In this case, the control device 200 controls the stretching device 160 within a range that does not exceed a preset threshold tension.

[0044] In the battery material manufacturing apparatus 100, the monitoring device 180 may have a sensor for monitoring the strain on the molded product. In this case, the control device 200 controls the stretching device 160 within a range in which the strain rate on the molded product does not exceed a preset threshold rate.

[0045] The battery material manufacturing apparatus 100 has been described above. With the above-mentioned configuration, the battery material manufacturing apparatus 100 can perform stretching after appropriately determining the stretching conditions under which no voids are generated in the molded product in the stretching section. The battery material manufacturing apparatus 100 stretches the thickness of the molded product M2 received from the sheet molding apparatus 140 to, for example, about 500 micrometers to 5 micrometers.

[0046] (Configuration of battery material manufacturing system) Next, other configurations of the battery material manufacturing system 10 will be described. The raw material input section 110 stores the raw material M1 and supplies the raw material M1 to the extrusion device 120 through a supply port. The raw material input section 110 may be a container called a hopper. The raw material input section 110 may include a rotary valve. The raw material M1 is a pellet of conductive resin in which a resin as a base material and a conductive filler are kneaded. The raw material M1 contains, for example, 50 weight percent or more of a conductive filler as a filler. The shape and size of the raw material M1 are not particularly limited, but the diagonal length in the case of a block shape is preferably 0.1 mm to 50 mm, and more preferably 1 to 20 mm.

[0047] The extrusion device 120 receives the raw material M1, kneads the received raw material M1, and supplies the kneaded product to the pump section 130. The pump section 130 supplies the kneaded product received from the extrusion device 120 to the sheet forming device 140. The pump section 130 is, for example, a gear pump. With this configuration, the extrusion device 120 can suitably knead the raw material and supply (pump) the kneaded product of the raw material M1 to the sheet forming device 140 with a predetermined pressure.

[0048] The sheet forming device 140 receives the kneaded material M1 from the pump section 130 and continuously delivers the sheet-shaped molded product M2. Specifically, the sheet forming device 140 includes a mold called a T-die. The sheet forming device 140 has an inlet 141, a stretching section 142, and a delivery port 143. The inlet 141 receives a fluid-like kneaded material obtained by kneading a base material and a filler. The extension section 142 guides the kneaded material in the delivery direction while stretching it in a direction perpendicular to the delivery direction. The delivery port 143 is a slit-shaped opening that can continuously deliver the stretched kneaded material as a molded product. The sheet forming device 140 supplies the sheet-shaped molded product M2 to the battery material manufacturing device 100 via the cast roller 150. At this time, the thickness of the molded product M2 delivered by the delivery port 143 is about 1000 micrometers to 1500 micrometers.

[0049] In addition to the above-mentioned configuration, the sheet forming apparatus 140 may have a temperature control device. The sheet forming apparatus 140 may also have a degassing unit. The degassing unit extracts bubbly gas contained in the raw material M1 inside the sheet forming apparatus 140.

[0050] The degassing section mainly comprises a branching section, a branching pipe, a storage section, and an outlet pipe. The branching section is a flow path provided in the flow path of the composition in the sheet forming apparatus 140. The purpose of the branching section is to extract gas such as air bubbles contained in the raw material M1. Therefore, the branching section can be provided in multiple locations in the sheet forming apparatus 140.

[0051] The branch pipe is a pipe for guiding at least the gas contained in the raw material M1 from the branching portion. The flow path cross-sectional area of ​​the branch pipe is not particularly limited, but it is preferable that the cross-sectional area corresponds to the flow speed when the raw material M1 passes through the sheet forming apparatus 140. For this reason, the branch pipe may have a valve for adjusting the flow path cross-sectional area of ​​the branch pipe at at least one point in the flow path. It is preferable that the valve has a mechanism for adjusting the opening degree by an electric signal.

[0052] The storage section is connected to the branch pipe, is provided above the branch pipe, and is a predetermined space having a flow cross-sectional area larger than that of the branch pipe. With this configuration, the degassing section can prevent the raw material M1 from flowing back beyond the storage section even if the raw material M1 itself flows into the branch pipe from the branch pipe.

[0053] The outlet pipe guides the gas accumulated in the storage section to the outside of the sheet forming apparatus 140. The outlet pipe is connected to, for example, a vacuum pump. This allows the degassing section to suck out the gas contained in the raw material M1. The vacuum pump may be connected to multiple outlet pipes. The storage section may be connected to multiple branch pipes. With this configuration, the battery material manufacturing system 10 can suppress the generation of air bubbles in the battery material.

[0054] The cast roller 150 receives the molded product M2 on the roller surface while rotating, and sends the received molded product M2 to the next process. The cast roller 150 cools the molded product M2 by contacting with the molded product M2, and solidifies the molded product M2. The cast roller may have a temperature control unit for setting the molded product M2 at a predetermined temperature. The cast roller 150 supplies the received molded product M2 to the battery material manufacturing apparatus 100. The cast roller 150 may further have a rotation drive unit, a displacement drive unit, and a drive control unit, so that the degree of solidification and the degree of stretching of the molded product M2 can be adjusted. In this case, for example, the cast roller 150 receives the sheet-shaped molded product sent out from the delivery port at a fourth conveying speed, and unwinds it while winding it up. The rotation drive unit also rotates and drives the cast roller 150 so as to send out the molded product M2 at a fifth conveying speed that is faster than the fourth conveying speed. The cast roller 150, the rotation drive unit, the displacement drive unit, and the drive control unit may be called a cast block. With the above-mentioned configuration, the casting roller 150 can stretch the molded product M2 while cooling it.

[0055] The rotation drive unit and the drive control unit control the speed of the surface of the cast roller 150 to a predetermined speed. For example, the cast roller receives a molded product M2 at a speed V1 and sends it out at a speed V2. Here, the speed V2 is set to be faster than the speed V1. The rotation drive unit includes a motor for rotating the cast roller 150, a sensor for measuring the rotation speed of the cast roller 150, and the like.

[0056] The displacement drive unit displaces the cast roller 150 in the Z-axis direction (i.e., the vertical direction) in FIG. 2 and the X-axis direction (i.e., the horizontal direction, or the thickness direction of the molded product M2 sent out in a sheet form). More specifically, the displacement drive unit includes, for example, a linear rail that can move along each of the Z-axis direction and the X-axis direction, a bearing that engages with the linear rail and supports the cast roller 150, and a motor that drives the bearing along the linear rail. The displacement drive unit displaces the cast roller 150 upon receiving a control signal from the drive control unit. This allows the cast roller 150 to suitably adjust the conditions for solidification and stretching of the molded product M2. Specifically, the displacement drive unit adjusts the position of the cast roller 150 in the vertical direction (Z-axis direction) to adjust the temperature of the molded product M2 in contact with the cast roller 150 and adjust the degree of solidification of the molded product M2. The displacement drive unit adjusts the position of the casting roller 150 in the horizontal direction (X-axis direction) to adjust the position of the casting roller 150 with which the molded product M2 comes into contact, thereby adjusting the degree of stretching of the molded product M2. The displacement drive unit may change the position of the casting roller 150 depending on the composition of the molded product M2.

[0057] The drive control unit includes a drive circuit that drives the rotation drive unit and the displacement drive unit, respectively, and an arithmetic circuit that drives the rotation drive unit and the displacement drive unit, respectively, in accordance with data regarding the rotation speed of the cast roller 150 and the position of the cast roller 150 received from the rotation drive unit and the displacement drive unit.

[0058] With the above-mentioned configuration, the cast roller 150 stretches the molded product M2, which is in a high-temperature and fluid state and sent out from the sheet forming device 140, while cooling it. In general, when resin is molded into a film and stretched, the resin is stretched in a solidified state. However, when the sheet-like molded product M2 containing filler is stretched in a solidified state, especially in the case of a thick sheet having a thickness of, for example, 1 mm, such as a sheet immediately after being sent out from the sheet forming device 140, there is a risk that the sheet may break or have uneven thickness during stretching. To prevent this, the post-process of the sheet forming device 140 needs to perform stretching at a relatively slow speed. Therefore, by performing a slight stretching in a molten state with the above-mentioned configuration, the battery material manufacturing system 10 can thin the sheet-like molded product M2 containing filler quickly, to a wide width, and uniformly. For example, with the above-mentioned configuration, the cast roller 150 stretches the molded product M2 having a thickness of 1000 micrometers to a thickness of 850 micrometers.

[0059] The rolling system 190 mainly includes a first rolling device 191, a second rolling device 192, and a third rolling device 193. The rolling system 190 receives the molded product M2 delivered by the cast roller 150 at a speed V2, and rolls the received molded product M2 by the first rolling device 191. The first rolling device 191 sandwiches the front and back of the molded product M2 between the rolling rollers, and delivers the molded product M2 at a speed V3 while compressing it.

[0060] The second rolling device 192 receives the formed product M2 rolled by the first rolling device 191 at a speed V3, and delivers the formed product M2 at a speed V4 while further compressing it. The third rolling device 193 receives the formed product M2 rolled by the second rolling device 192 at a speed V4, and delivers the formed product M2 at a speed V5 while further compressing it.

[0061] At this time, the delivery speed of each rolling device is not particularly limited. However, for example, it is preferable that the delivery speed of the subsequent rolling device is faster, such as V2 < V3 < V4 < V5. By controlling the speed of each rolling device of the rolling system 190 individually in this way, the rolling system 190 can superimpose the force that expands in the thickness direction of the molded product M2 and the force that stretches in the delivery direction of the current collector P10. Therefore, using the rolling system 190, the molded product M2 can be processed quickly and thinly. Thus, the battery material manufacturing system 10 can improve productivity.

[0062] In addition to the above-described configuration, the rolling system 190 may further include a heating device. Also, the rolling system 190 only needs to have one or more rolling devices. The rolling system 190 rolls the thickness of the molded product M2 received from the casting roller 150 to about 500 micrometers from 850 micrometers, for example.

[0063] The winding device 170 receives the molded product M2 sent out by the battery material manufacturing device 100 and winds the received molded product M2 into a roll.

[0064] The configuration of the battery material manufacturing system 10 has been described above. In the above-described configuration, the battery material manufacturing system 10 gradually stretches the battery material formed in a sheet shape. Thereby, the battery material manufacturing system 10 can continuously and efficiently manufacture the battery material while suppressing the generation of voids.

[0065] Note that the battery material manufacturing system 10 may further include a process of manufacturing the molded product M2 cut into a sheet shape by cutting the molded product M2 with a cutting device using a cutter, a cutting roller, or the like. Alternatively, the battery material manufacturing system 10 may further include a process of laminating or enclosing a plurality of molded products M2 or sheet-shaped battery materials. That is, the battery material manufacturing system 10 may have a lamination molding system that stacks and laminates sheet-shaped objects to be laminated including at least one cut molded product M2 to manufacture a laminate.

[0066] The battery material manufacturing system 10 may also have a lamination molding system that stacks and bonds a plurality of cut molded products M2, which are objects to be laminated. The plurality of molded products M2 may have the same composition or different compositions. The plurality of molded products M2 may be, for example, a negative electrode current collector P11 and a current collecting substrate P12, or a current collector P10 and a current collecting substrate P12. The sheet-shaped battery material is, for example, a resin such as a conductive polymer or a separator having fine voids. The sheet-shaped battery material is, for example, a metal such as aluminum foil or copper foil. The step of encapsulating the battery material may be a step of encapsulating the battery material including the molded product M2 with an exterior material made of resin or metal. In this case, the step of encapsulating the battery material may be a step of increasing the adhesiveness of the exterior material by disposing a frame-shaped thermosetting resin between the first metal foil and the second metal foil.

[0067] The lamination molding system may be responsible for the step of laminating or sealing the battery material. The lamination molding system has a vacuum chamber that opens and closes from above and below, and presses the laminated object including the cut molded product M2 under a reduced pressure environment. Specifically, the lamination molding system receives, from one end side, a rectangular laminated object cut to have a side of about 50 to 600 millimeters. Next, the lamination molding system closes the vacuum chamber to make the inside of the vacuum chamber airtight, and then reduces the pressure in the vacuum chamber to a predetermined pressure using a vacuum pump or the like. The predetermined pressure is, for example, an air pressure of 1 hectopascal or less. Next, the vacuum chamber presses a predetermined region of the laminated object with a predetermined pressure. The predetermined pressure is, for example, a pressure of 0.1 to 10 megapascals. Finally, the lamination molding system sends out the laminated object from the other end side and simultaneously receives the next laminated object from the one end side. The lamination molding system has a control unit for controlling a series of operations and adjustment of the atmosphere in the vacuum chamber. This control unit may be included in the above-mentioned control device 200.

[0068] The means for receiving and sending the laminated object to the laminated molding system is not particularly limited, but for example, the laminated object can be placed on a polyethylene terephthalate (PET) sheet inserted into a vacuum chamber, and the sheet can be intermittently moved in conjunction with the operation of the vacuum chamber or the like. The pressing means of the laminated molding system is not particularly limited, and for example, the upper and lower press plates may be hydraulically or electrically raised and lowered, or may include a means for supplying gas to a predetermined air pressure. Alternatively, the pressing means may utilize the expansion and contraction of a diaphragm-like flexible sheet made of a heat-resistant polymer. In addition, when a frame-shaped thermosetting resin is placed between the first metal foil and the second metal foil and a battery material that is a laminate including the molded product M2 is enclosed, it is desirable that the battery material manufacturing system 10 has a frame-shaped press surface on one of the upper and lower press plates. At this time, the location where the exterior material is attached has unevenness due to electrode tabs, etc. For this reason, in order to accommodate such irregularities, it is preferable that the lower press surface be made of a mirror-finished metal plate and the upper press surface be made of a metal plate containing a frame-shaped heat-resistant resin or heat-resistant rubber, for example.

[0069] The lamination molding system may also have a temperature adjustment mechanism such as a heater or a heat medium for adjusting the temperature of the lamination object. The temperature adjustment mechanism may be included in the mechanism for pressurizing the lamination object, or may be provided in another location. The temperature adjustment mechanism adjusts the temperature of the lamination object to be within a range of, for example, room temperature to about 200 degrees Celsius. In this way, the lamination molding system can suitably bond and encapsulate the battery material.

[0070] This enables the lamination molding system to prevent the occurrence of lamination defects such as air bubbles remaining in gaps between objects to be laminated, and to bond and encapsulate battery materials including the molded product M2 with good productivity.

[0071] Next, the functional configuration of the battery material manufacturing system 10 will be further described with reference to FIG. 3. FIG. 3 is a block diagram of the battery material manufacturing system 10. The battery material manufacturing system 10 has, as its main components, a battery material manufacturing apparatus 100, an extrusion apparatus 120, a sheet forming apparatus 140, a cast roller 150, and a winding apparatus 170. Each component shown in FIG. 3 is appropriately connected to be able to communicate with each other. As shown in FIG. 3, the extrusion apparatus 120, the sheet forming apparatus 140, the cast roller 150, and the winding apparatus 170 are connected to a control device 200 included in the battery material manufacturing apparatus 100 so as to be able to communicate with each other. That is, each of these components is controlled by the control device 200.

[0072] The stretching device 160 according to this embodiment may have a temperature control unit 163 that controls the temperature of the molded product. The temperature control unit 163 controls the atmosphere of the stretching device 160 so that the molded product M2 has a preset temperature. The temperature control unit 163 controls the temperature of the stretching device 160 in cooperation with the control device 200. In this case, the monitoring device 180 has a temperature sensor. Also, the control device 200 determines the stretching conditions according to the temperature of the molded product. This allows the battery material manufacturing system 10 to set more efficient and robust stretching conditions.

[0073] The control device 200 includes a calculation device such as a CPU (Central Processing Unit) or an MCU (Micro Controller Unit). The control device 200 includes a calculation unit 201 and a storage unit 202. The control device 200 determines the stretching conditions from data received from a monitoring device 180 that monitors the state of the molded product, and controls the stretching device so that no voids are generated in the molded product.

[0074] The calculation unit 201 determines the stretching conditions from the data received from the monitoring device 180, and selects or calculates parameters for controlling each component of the battery material manufacturing system 10 according to the determination result. For example, the calculation unit 201 calculates the yield time at which at least a part of the monitoring units set in the molded product reaches the yield tension after the start of stretching, and the completion time at which the monitoring units complete the stretching process. In this case, if the yield time is before the completion time, the control device 200 controls the stretching device to change the stretching speed. On the other hand, if the yield time is after the completion time, the control device 200 controls the stretching device to maintain the stretching speed.

[0075] The control device 200 also has a function of communicatively connecting to each component of the battery material manufacturing system 10 and controlling each component. This allows the battery material manufacturing system 10 to cooperate with the sheet forming device 140 and the battery material manufacturing device 100, and allows the battery material to be manufactured more efficiently. The communicative connection means may be wireless or wired. It is also preferable that the control device 200 has a display that visibly displays the control state of each component of the battery material manufacturing system 10. Furthermore, the control device 200 may visibly display the state of each component of the battery material manufacturing system 10 on a medium other than the display provided on the control device 200 via wireless communication. The medium other than the display provided on the control device 200 is, for example, a personal computer, a tablet, or a smartphone. In this case, it is further preferable that the battery material manufacturing system 10 can remotely execute, change, stop, or otherwise control each component of the battery material manufacturing system 10 via those media or software installed on those media.

[0076] The storage unit 202 is a storage device having at least a non-volatile memory such as a flash memory or an SSD (Solid State Drive). The storage unit 202 stores at least a program executed by the control device 200. The storage unit 202 also stores data related to the extension conditions determined by the control device 200. That is, the control device 200 controls the extension device 160 by referring to the data received from the monitoring device 180 and the data related to the extension conditions stored in the storage unit 202. The storage unit 202 may also have an interface for electronically or visually outputting past data to the outside.

[0077] The functional configuration of the battery material manufacturing system 10 has been described above. With the above-mentioned configuration, the battery material manufacturing apparatus 100 can stretch a molded product while suppressing the occurrence of voids. Therefore, the battery material manufacturing system 10 can continuously manufacture battery materials. The battery material manufacturing system 10 may have two or more control devices 200. In that case, the battery material manufacturing system 10 may control the battery material manufacturing system 10 in cooperation with a plurality of control devices connected to each other so as to be able to communicate with each other.

[0078] Next, the state of the molded article before and after stretching will be described with reference to Fig. 4. Fig. 4 is a diagram for explaining the state of the molded article. The molded article M2 before stretching is shown on the left side of Fig. 4. Here, in the molded article M2 before stretching, filler F2 is dispersed and disposed on a base material F1.

[0079] The upper right corner of Figure 4 shows a molded product M2 after stretching under stretching condition C1. Stretching condition C1 is a condition that generates voids in the molded product. Therefore, in the molded product M2 after stretching, voids F3 are generated around the filler F2.

[0080] The bottom right of Fig. 4 shows a molded product M2 after stretching under stretching condition C2. Stretching condition C2 is a condition under which no voids are generated in the molded product. Therefore, in the molded product M2 after stretching, no voids F3 are generated around the filler F2.

[0081] In this way, the molded article M2 may or may not have voids after stretching depending on the stretching conditions. Therefore, the battery material manufacturing apparatus 100 determines the stretching conditions under which no voids are generated, and stretches the molded article under these stretching conditions.

[0082] Next, the stretching conditions will be described with reference to the relationship between the strain and tension of the molded article with reference to Fig. 5. Fig. 5 is a first graph showing the relationship between the strain and tension of the molded article. In the graph shown in Fig. 5, the horizontal axis represents strain (S) and the vertical axis represents tension (T).

[0083] In the graph, the data of sample M11 is plotted by a dashed line. In the data of sample M11, point R11 indicated by a circle is the boundary where voids occur. In other words, when a tension higher than tension T11 is applied to sample M11, voids occur.

[0084] The graph also shows the data for sample M12 as a solid line below the data for sample M11. In the data for sample M12, point R12, indicated by a circle, is the boundary at which voids occur. That is, when a tension higher than tension T12 is applied to sample M12, voids occur.

[0085] As shown in Fig. 5, the plotted data varies depending on the sample. Therefore, when stretching a molded product while monitoring the tension applied to the molded product, the battery material manufacturing apparatus 100 sets the threshold tension Tth to a value lower than the tension T12, for example. This allows the battery material manufacturing apparatus 100 to stretch the molded product while applying a tension lower than the threshold tension Tth under conditions where no voids are generated.

[0086] Next, variations in the stretching conditions will be described. The diagonal straight line indicated by the bold two-dot chain line at point R12 of sample M12 indicates the rate of change dT / dS between strain S and tension T. Although the tensions applied when voids are generated are different between sample M11 and sample M12, the rate of change dT / dS between strain S and tension T is approximately the same. Therefore, the battery material manufacturing apparatus 100 can set a threshold value for the rate of change dT / dS between strain S and tension T, for example. This allows the battery material manufacturing apparatus 100 to stretch the molded product while monitoring the rate of change dT / dS between strain S and tension T.

[0087] Next, the temperature and strain rate of the molded product when stretching the molded product will be described with reference to Fig. 6. Fig. 6 is a second graph showing the relationship between the strain and tension of the molded product. In the graph shown in Fig. 6, the horizontal axis represents strain and the vertical axis represents tension, similar to the graph in Fig. 5. The graph in Fig. 6 is for a case where the atmosphere during stretching or the temperature of the molded product (stretching temperature) is 50 degrees Celsius.

[0088] In FIG. 6, data for a strain rate of 1.0 s-1 is plotted by a bold solid line. In this case, voids will occur in the molded product if it is subjected to a strain greater than the strain at point R21. Below the data for a strain rate of 1.0 s-1, data for a strain rate of 0.5 s-1 is plotted by a bold dashed line. In this case, voids will occur in the molded product if it is subjected to a strain greater than the strain at point R22. Below the data for a strain rate of 0.5 s-1, data for a strain rate of 0.1 s-1 is plotted by a thin solid line. In this case, voids will not occur in the molded product within the strain range shown in this graph.

[0089] In this way, when the stretching temperature is 50° C., if the strain rate applied to the molded product is different, the conditions (stretching conditions) under which voids are generated in the molded product are different.

[0090] Figure 7 is a third graph showing the relationship between the strain and tension of a molded product. In the graph shown in Figure 7, the horizontal axis represents strain and the vertical axis represents tension, as in the above graphs. The graph in Figure 7 is for a stretching temperature of 125 degrees Celsius.

[0091] In FIG. 7, data for a strain rate of 1.0 s-1 is plotted by a bold solid line. In this case, voids will occur in the molded product if it is subjected to a strain larger than the strain at point R31. Below the data for a strain rate of 1.0 s-1, data for a strain rate of 0.5 s-1 is plotted by a bold dashed line. In this case, voids will occur in the molded product if it is subjected to a strain larger than the strain at point R32. Below the data for a strain rate of 0.5 s-1, data for a strain rate of 0.1 s-1 is plotted by a thin solid line. In this case, voids will occur in the molded product if it is subjected to a strain larger than the strain at point R33.

[0092] As described above, when a molded product is stretched, the conditions for void generation depend on the stretching temperature. Also, when a molded product is stretched, the conditions for void generation depend on the strain rate. Therefore, in the battery material manufacturing apparatus 100, the control device 200 receives these data from the monitoring device 180, determines the stretching conditions according to each data, and controls the stretching device 160. As a result, the battery material manufacturing apparatus 100 can perform the stretching process of the molded product while efficiently suppressing the generation of voids.

[0093] Next, the process executed by the battery material production system 10 will be described with reference to Fig. 8. Fig. 8 is a flowchart of a battery material production method.

[0094] First, the battery material manufacturing system 10 adjusts the temperature of each component in response to a user's operation (step S10). In this case, the battery material manufacturing system 10 adjusts the temperature of the battery material manufacturing apparatus 100 as well as the sheet molding apparatus 140, the cast roller 150, etc.

[0095] Next, the battery material manufacturing system 10 starts driving each component and inputting the raw material (step S20). Specifically, the battery material manufacturing system 10 starts driving, for example, the stretching rollers of the stretching device 160. Alternatively, the battery material manufacturing system 10 starts driving the screw of the extrusion device 120. Then, the battery material manufacturing system 10 inputs the raw material M1 into the extrusion device 120.

[0096] Next, in the battery material manufacturing system 10, the sheet forming device 140 sends out the molded product M2 from the kneaded material (step S30). Furthermore, the battery material manufacturing system 10 supplies the molded product M2 to the battery material manufacturing device 100, which stretches the molded product M2 (step S40).

[0097] Next, the battery material manufacturing system 10 causes the winding device 170 to wind up and collect the molded product sent out by the battery material manufacturing device 100 (step S50).

[0098] Next, the process executed by the battery material manufacturing apparatus 100 will be described with reference to Fig. 9. Fig. 9 is a flowchart showing a method for controlling the elongation apparatus. The flowchart shown in Fig. 9 shows details of step S40 in Fig. 8.

[0099] First, the battery material manufacturing apparatus 100 starts receiving the molded product M2 (step S41). More specifically, the battery material manufacturing apparatus 100 receives the molded product M2 from the sheet molding apparatus 140, which continuously delivers the sheet-like molded product M2 obtained by kneading the base material and the filler, via the cast roller 150. Here, the battery material manufacturing apparatus 100 stretches the received molded product M2 so that the thickness of the molded product M2 becomes thinner. Specifically, the battery material manufacturing apparatus 100 receives the molded product M2 at a first conveying speed, for example, and delivers the molded product M2 at a second conveying speed while conveying the received molded product M2. This causes the molded product M2 to be stretched so that the thickness of the molded product M2 becomes thinner.

[0100] Next, the control device 200 receives data from the monitoring device 180 (step S42). Here, the monitoring device 180 generates data according to a preset method for determining the stretching conditions among the various data described above, and supplies the data to the control device 200. In addition, the control device 200 also receives data according to the preset method for determining the stretching conditions from the monitoring device 180. That is, the control device 200 acquires monitoring data from the monitoring device 180, which monitors at least one of the tension, distortion, and thickness applied to the molded product at a plurality of different positions.

[0101] Next, the control device 200 determines whether the delivery speed VOUT at which the molded product M2 is delivered in the elongation device 160 is faster than the receiving speed VIN at which the molded product M2 is received (step S43). If it is determined that the delivery speed VOUT is faster than the receiving speed VIN (step S43: YES), the battery material manufacturing apparatus 100 proceeds to step S44. If it is not determined that the delivery speed VOUT is faster than the receiving speed VIN (step S43: NO), the battery material manufacturing apparatus 100 proceeds to step S46.

[0102] In step S44, the control device 200 determines whether the monitoring data received from the monitoring device 180 is within the range of the stretching conditions. If it is within the range of the stretching conditions, no voids are generated in the molded product M2. On the other hand, if it is not within the range of the stretching conditions, there is a possibility that voids are generated in the molded product M2. Therefore, if the control device 200 determines that the monitoring data is within the range of the stretching conditions (step S44: YES), the battery material manufacturing apparatus 100 proceeds to step S45. On the other hand, if the control device 200 does not determine that the monitoring data is within the range of the stretching conditions (step S44: NO), the battery material manufacturing apparatus 100 proceeds to step S46.

[0103] In step S45, the control device 200 judges whether the thickness BOUT of the molded product M2 at the position where the stretching device 160 sends out is within the range of the required specifications of the product. More specifically, the control device 200 judges whether the thickness BOUT of the molded product M2 received from the monitoring device 180 is equal to or greater than B1 and less than B2 (step S45). If the control device 200 judges that the thickness BOUT of the molded product M2 is equal to or greater than B1 and less than B2 (step S45: YES), the battery material manufacturing apparatus 100 returns to step S43 and continues monitoring the stretching conditions. On the other hand, if the control device 200 does not judge that the thickness BOUT of the molded product M2 is equal to or greater than B1 and less than B2 (step S45: NO), the battery material manufacturing apparatus 100 proceeds to step S46.

[0104] In step S46, the control device 200 controls the stretching device 160 (step S46). Here, the control of the stretching device 160 differs depending on the status of the monitoring data, etc. The control device 200 changes, for example, at least one of the conveying speed and the stretching temperature of the stretching device 160. After the control device 200 controls the stretching device 160, the battery material manufacturing apparatus 100 returns to step S43 and continues to monitor the molded product M2 and control the stretching device 160.

[0105] As described above, the control device 200 determines the stretching conditions under which no voids are generated in the molded product M2 based on the monitoring data, and controls the stretching device 160 based on the stretching conditions. This allows the battery material manufacturing apparatus 100 to continuously and efficiently manufacture battery material while suppressing the generation of voids.

[0106] In the configuration of the battery material manufacturing system described above, the shape of the roller is not limited to a cylindrical or columnar shape, but may be a polyhedron or a gear shape. The roller may be oscillated or vibrated while being controlled to a predetermined amplitude or frequency by a power source such as a motor. This allows the battery material manufacturing system 10 to suitably solidify, roll, stretch, and wind up the molded product M2.

[0107] Although the present invention has been described above with reference to the embodiment, the present invention is not limited to the above. Various modifications that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the invention. [Explanation of symbols]

[0108] 10. Battery material manufacturing system 100 Battery material manufacturing equipment 110 Raw material input section 120 Extrusion Equipment 130 Pump section 140 Sheet forming equipment 141 Inlet 142 Extension Department 143 Outlet 150 Cast Roller 160 Stretching device 161 1st extension section 162 2nd extension section 163 Temperature control unit 170 Winding device 180 Monitoring equipment 181 First Sensor 182 Second Sensor 183 3rd Sensor 190 Rolling System 191 First Rolling Mill 192 No. 2 Rolling Mill 193 No. 3 Rolling Mill 200 Control device 201 Arithmetic section 202 Storage section F1 base material F2 Filler F3 void M1 raw material M2 molded product P10 Current collector P11 Negative electrode current collector P12 Current collector substrate P13 Positive electrode current collector P20 positive electrode layer P30 Separator P40 negative electrode layer P100 battery

Claims

1. A sheet-like molded product including a substrate and a filler is prepared; Cutting the molded product, A sheet-like laminate object including at least one cut molded article is laminated. Method for producing battery materials.

2. The laminated objects are bonded together under a reduced pressure environment. The method for producing a battery material according to claim 1 .

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