Roll press apparatus and roll press control method

Abstract

The objective is to realize a battery electrode structure that suppresses localized battery degradation. [Solution] The roll press device 100A is configured to manufacture an electrode sheet 1 to be housed in a battery by pressing a sheet-shaped current collector 2 coated with an electrode mixture in a roll press section 105A. The storage unit 102A stores the press conditions corresponding to the finished thickness of the electrode sheet 1 according to the amount of electrode mixture coating set according to the arrangement of the electrode sheet 1 when it is housed, and the press control unit 104A controls the press operation on the current collector 2 based on the press conditions stored in the storage unit 102A.

Description

Technical Field

[0001] The present invention relates to, for example, a roll press device and a roll press control method.

Background Art

[0002] Today, as a response to green manufacturing in the battery field, further market growth is expected through the practical application of next-generation batteries. Among them, the manufacturing process greatly affects the battery life.

[0003] Although the battery deteriorates through repeated use, the progress of deterioration does not uniformly progress inside the battery. Due to the battery structure, it is likely to progress in areas where the load is concentrated, etc., which causes a decrease in safety in addition to battery deterioration.

[0004] Therefore, a battery and a manufacturing method for preventing the misalignment of the positive electrode plate and the negative electrode plate have been proposed (Patent Document 1).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In the above prior art, when manufacturing the battery electrodes uniformly, there are problems such as high stress in the portions with high electrode curvature during the formation of the wound group, leading to cracking of the electrode plate and easy peeling of the active material agent from the current collector foil.

[0007] The present invention has been made in view of such a background, and an object thereof is to provide a roll press device and a roll press control method that realize a battery electrode structure for suppressing local battery deterioration.

Means for Solving the Problems

[0008] To solve the above-mentioned problems and achieve the above objective, one embodiment of the present invention is a roll press apparatus for manufacturing an electrode sheet to be placed in a battery by moving a sheet-like current collector coated with an electrode mixture and pressing it with a plurality of rolls, wherein the amount of electrode mixture to be coated is set differently for each region of the current collector according to the arrangement conditions when the electrode sheet is placed, and the apparatus is characterized by comprising: a storage unit that stores the pressing conditions of a plurality of rolls corresponding to the finished thickness of the electrode sheet determined according to the amount of electrode mixture to be coated; a detection unit that detects the region of the current collector to be pressed when the current collector is moved; and a control unit that controls the pressing operation of a plurality of rolls on the current collector based on the pressing conditions stored in the storage unit for the region detected by the detection unit.

[0009] Another embodiment of the present invention is a roll press apparatus for manufacturing an electrode sheet to be placed in a battery by moving a sheet-like current collector coated with an electrode mixture and pressing it with a plurality of rolls, wherein the surface of the current collector is marked to specify press conditions corresponding to the finished thickness after pressing with a plurality of rolls, and the apparatus comprises a storage unit that stores the press conditions in association with the marks, a detection unit that detects the marks applied to the current collector before pressing, a determination unit that refers to the storage unit and determines the press conditions based on the marks detected by the detection unit, and a control unit that controls the pressing operation of the plurality of rolls on the current collector based on the press conditions determined by the determination unit.

[0010] Another embodiment of the present invention is a roll press control method for an apparatus that manufactures an electrode sheet for which a sheet-like current collector coated with an electrode mixture is moved and pressed by a plurality of rolls to be stored in a battery, characterized in that different amounts of the electrode mixture are set for each region of the current collector according to the arrangement conditions when the electrode sheet is stored, the press conditions of the plurality of rolls are stored in memory in accordance with the finished thickness of the electrode sheet determined according to the amount of the electrode mixture, the region of the current collector to be pressed when the current collector is moved, and the press operation of the plurality of rolls on the current collector is controlled in the detected region based on the press conditions stored in memory.

[0011] Another embodiment of the present invention is a roll press control method for an apparatus for manufacturing an electrode sheet, which is a sheet-like current collector coated with an electrode mixture, which is moved and pressed by a plurality of rolls to be housed in a battery. The method is characterized in that the surface of the current collector is marked to specify press conditions corresponding to the finished thickness after pressing by a plurality of rolls, the press conditions are stored in memory in association with the marks, the marks applied to the current collector are detected before pressing, the press conditions are determined based on the detected marks by referring to the memory, and the pressing operation of the plurality of rolls on the current collector is controlled based on the determined press conditions. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a roll press apparatus and a roll press control method that can realize a battery electrode structure that suppresses localized battery degradation. [Brief explanation of the drawing]

[0013] [Figure 1] This is an explanatory diagram illustrating the electrode fabrication process according to Embodiment 1 of the present invention. [Figure 2] This is an explanatory diagram illustrating the state in which the electrode sheet is housed in the battery in Embodiment 1 of the present invention. [Figure 3] This is a block diagram showing the function of a roll press device according to Embodiment 1 of the present invention. [Figure 4] This is an explanatory diagram illustrating a pressing method according to Embodiment 1 of the present invention. [Figure 5] This is an explanatory diagram showing an example of a table configuration according to Embodiment 1 of the present invention. [Figure 6] This is a diagram showing an example of the hardware configuration of a roll press apparatus according to Embodiment 1 of the present invention. [Figure 7] This is a flowchart illustrating an example of operation according to Embodiment 1 of the present invention. [Figure 8] This diagram shows the function of a roll press device according to Embodiment 2 of the present invention. [Figure 9] It is an explanatory diagram showing an example of a table configuration according to Embodiment 2 of the present invention. [Figure 10] It is a flowchart for explaining an example of an operation according to Embodiment 2 of the present invention. [Figure 11] It is a block diagram showing the functions of a roll press device according to Embodiment 3 of the present invention. [Figure 12] It is a flowchart for explaining an example of an operation according to Embodiment 3 of the present invention. [Figure 13] It is a block diagram showing the functions of a roll press device according to Embodiment 4 of the present invention. [Figure 14] It is an explanatory diagram showing an example of a table configuration according to Embodiment 4 of the present invention. [Figure 15] It is a flowchart for explaining an example of an operation according to Embodiment 4 of the present invention. [Figure 16] It is a block diagram showing the functions of a roll press device according to Embodiment 5 of the present invention. [Figure 17] It is a flowchart for explaining an example of an operation according to Embodiment 5 of the present invention. [Figure 18] It is an example of the roll press device condition setting database in the embodiments of the present invention.

Modes for Carrying Out the Invention

[0014] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the following description and drawings are merely examples for explaining the present invention, and for the sake of clarity of the explanation, appropriate omissions and simplifications are made. In addition, the present invention can also be implemented in various other forms. Also, unless otherwise particularly limited, each component may be in a single or plural number.

[0015] In the following explanation, identical or similar structures may be denoted by the same symbol, and redundant explanations may be omitted. Also, in the following explanation, various types of information may be described using expressions such as "information" and "table," but these types of information may be represented by data structures other than these. Furthermore, while expressions such as "identification information," "identifier," "name," "ID," and "number" may be used to represent identification information, these can be substituted for each other. In the following explanation, "database" will be abbreviated as "DB" and "table" as "TBL." <Embodiment 1> First, the electrode fabrication process will be explained using Figure 1. The electrode fabrication process shown in Figure 1 consists of a mixing process ST1, a coating process ST2, a drying process ST3, a pressing process ST4, and a cell assembly process ST5.

[0016] First, in the mixing process ST1, the electrode materials (active material, conductive agent, binder, etc.) are uniformly mixed, and in the coating process ST2, the mixed electrode materials are applied to the current collector (aluminum foil, copper foil, etc.).

[0017] Then, in the drying process ST3, the coated electrode material is dried, and in the pressing process ST4, the dried electrode material is compressed to increase its density. This is how an electrode sheet is manufactured. Embodiment 1, described below, shows roll press manufacturing in the pressing process ST4.

[0018] In the final cell assembly process, the electrodes are wound or stacked together with the separator to assemble the battery cell, thus completing the battery cell.

[0019] Here, the method of winding the electrode sheet will be explained using Figure 2. Figure 2 shows an example of winding the electrode sheet 1 in the winding direction R for a rectangular battery. In the electrode sheet 1, for example, the shape of the winding body is determined according to the box shape of the rectangular battery 500A and 500B. In the example in Figure 2, the electrode sheet 1 is wound so that the winding curvature is large at both ends.

[0020] As will be explained in more detail later, winding areas with a large winding curvature experience significant stress. Therefore, it is necessary to adjust the thickness of the electrode mixture during the coating process. Specifically, winding areas with a large winding curvature experience high stress during winding, leading to problems such as peeling of the electrode mixture. To address this, winding areas with a large winding curvature are pre-treated during the coating process to form thinly coated areas on the current collector, while other areas are pre-treated to form thickly coated areas on the current collector with a predetermined thickness.

[0021] Next, we will explain the function using Figure 3. Figure 3 shows the roll press device 100A of Embodiment 1. Here, both the electrode sheet 1 and the current collector 2 have long, sheet-like bodies, but for explanatory purposes, they are shown in a simplified form in each figure.

[0022] The roll press device 100A consists of a control unit 101A, a roll section 105 composed of a pair of rolls, a position detection sensor 106A, and the like. The roll press device 100A is also connected to an external device 200 via a network (not shown). This external device 200 is configured to include a CPU such as a personal computer, a communication unit, and input / output devices for input and display.

[0023] The control unit 101A consists of a storage unit 102A that stores press control TBL 103A and the like, which are configured based on press control information acquired from an external device 200, and a press control unit 104A that controls a roll press unit 105A, which is composed of a pair of rolls, based on the press control information of the press control TBL 103A.

[0024] The roll section 105 consists of a pair of rolls and performs rolling (roll pressing) of the current collector 2 under the control of the press control unit 104A. The position detection sensor 106AA detects the movement position of the sheet-like current collector 2 as it passes between the rolls using a device such as a camera and outputs the movement position to the press control unit 104A. Note that this device and its detection technology are well known and therefore will not be explained further.

[0025] As will be described in detail later, when the press control unit 104A receives the movement position from the position detection sensor 106A, it reads the press control conditions (hereinafter referred to as press conditions) from the press control information of the press control TBL 103A based on that movement position and performs press control with a rolling force that distinguishes between the thick-coated section and the thin-coated section as described above.

[0026] Here, the pressing principle will be explained using Figure 4. In Embodiment 1, the manufactured electrode sheet 1 is coated with electrode mixture 30 on both sides of the current collector 2. Regarding the thickness of the electrode mixture 30 coating, as shown in the cross-section and top view of Figure 4, thick-coated sections 31 set to a predetermined coating thickness and thin-coated sections 31 set to a thinner coating thickness than the thick-coated sections 31 are formed alternately, so that the thickness changes alternately.

[0027] As shown in Figure 4, the wound electrode sheet 1 has a larger winding curvature at its ends 12A and 12B, and these are areas where the stress is greater than at other points. Therefore, the areas corresponding to the ends 12A and 12B, where the winding curvature is larger, are prepared in the coating process to become thin-coated sections 32, and the rolling force is set to a smaller value than that of the thick-coated sections 31. L1 to L6 indicate the electrode positions, and further details will be described later.

[0028] Here, we will explain the press control information using Figure 5. Figure 5 shows the press control TBL103A, which is composed of this press control information. The press control TBL103A stores the coating amount, density, finished thickness, and press conditions, corresponding to the electrode position.

[0029] Furthermore, this electrode thickness and position information is linked to design information such as applying a thinner coating to areas of high stress in response to the stress on the electrode sheet.

[0030] As shown in Figure 4, the combination of electrode positions L1 and L2 corresponds to the end 12A, and as shown in Figure 5, the coating amount "Specification 1", density "d1", finished thickness "a1", and press condition "1" are stored in association with it. The combination of electrode positions L5 and L6 also corresponds to the end 12A and has a similar data structure.

[0031] The combination of electrode positions L3 and L4 corresponds to the end portion 12B, and as shown in Figure 5, the coating amount "Specification 2", density "d2", finished thickness "a2", and press condition "2" are stored in association with each other.

[0032] Regarding the coating amount, Specification 1 is information that defines the coating thickness for forming the thickly coated portion 31, and applies, for example, to the combination of electrode positions L3 and L4. Specification 2 is information that defines the coating thickness for forming the thinly coated portion 32, and applies, for example, to the combination of electrode positions L1 and L2, and the combination of electrode positions L5 and L6.

[0033] Density is data that defines the degree of compression during pressing to determine the finished thickness; a higher density means that more active material is contained at the same thickness. Finished thickness is data set in accordance with the specifications indicated by the coating amount, defining the thickness of electrode sheet 1 after manufacturing for the coating amount specified in specification 1. Furthermore, press conditions are data that defines control conditions such as the rolling force required to roll to the finished thickness. Press conditions include data such as the roller rotation speed and the gap between rollers.

[0034] Next, the control unit 101A will be described using Figure 6. Figure 6 shows an example of the hardware configuration in the control unit 101A of the roll press machine.

[0035] The control unit 101A is composed of, for example, a CPU 1001 that controls the entire device, a memory 1003 that stores programs 1002 such as processes to be executed by the CPU 1001 (see Figure 7) and various data being executed, an operating device 1004 equipped with a keyboard and display device which are configured as software or hardware, an external storage device 1005 that registers and stores various data in the format of a DB, press control TBL 103A, etc., a communication IF 1006 connected to the network 300 and responsible for various external communications, and a bus 1707 connected to each unit within the control unit 101A and responsible for internal data, signal, and other communications.

[0036] Here, the press control unit 104A consists of a CPU 1001, memory 1003, communication IF 1006, and the like.

[0037] Next, we will explain the operation using Figure 7. Figure 7 shows an example of the operation of the control unit 101A. The following operation shows the process in which the CPU 1001 executes program 1002 within the control unit 101A.

[0038] First, prior to press control, press control information is received from the external device 200 and stored in the press control TBL 103A as shown in Figure 5 (step S71). In the electrode creation process shown in Figure 1, once the start of the press process ST4 is confirmed (step S72), the current collector 2 is fed into the roll press section 105A.

[0039] Until the end of the pressing process (step S74), when the current collector 2's movement position is detected by the position detection sensor 106A, that movement position is compared with the electrode position stored in the press control TBL 103A. If the comparison matches, the pressing conditions corresponding to the matched electrode position are read out (step S75), and the rolling of the roll press section 105A is controlled according to those pressing conditions (step S76).

[0040] Regarding the start and end of the pressing process, examples include receiving instructions from other external devices, storing the start and end positions in the press control TBL103A, and assigning start and end marks to the current collector 2 that can be detected by the position detection sensor 106A.

[0041] In this way, the roll press device 100A moves the current collector 2, which is in sheet form and coated with electrode mixture, and presses it with multiple rolls to manufacture an electrode sheet 1 to be housed in the battery. Depending on the arrangement conditions such as the rotational curvature when the electrode sheet 1 is housed, it is necessary to pre-set different amounts of electrode mixture to be applied to each electrode position of the current collector 2.

[0042] Therefore, a press control TBL103A, which stores press conditions corresponding to the finished thickness of the electrode sheet 1 determined by the amount of electrode mixture applied, is involved in the rolling control. When the current collector 2 moves during the pressing process, the position detection sensor 106A detects the area of ​​the current collector 2, and the rolling operation on the electrode sheet 1 is controlled based on the press conditions.

[0043] As described above, according to Embodiment 1, for electrodes where the curvature of the electrode sheet is high during winding is thinned during electrode coating, it is possible to create an electrode plate with a desired electrode thickness by changing the parameters of the press conditions so that the electrode thickness differs between the high-curvature and non-high-curvature parts. As a result, it is possible to realize a battery electrode structure that suppresses localized battery degradation. Furthermore, making the electrode film thickness non-uniform has the advantage of obtaining a suitable current distribution and expansion / contraction resistance after electrode winding.

[0044] <Embodiment 2> Next, Embodiment 2 will be described using Figures 8 to 10. Figure 8 shows the function of the roll press apparatus of Embodiment 2, and Figure 9 shows an example of the table configuration of Embodiment 2.

[0045] In the aforementioned Embodiment 1, the electrode position is stored in the press control TBL103A, and the press operation is performed according to the press conditions by detecting the electrode position. In contrast, in Embodiment 2, a mark detectable by a sensor is placed on the current collector, and the press operation is performed according to the press conditions by detecting the mark.

[0046] Therefore, in Embodiment 2, the explanation of the configuration similar to that of Embodiment 1 will be omitted, and only the differences will be explained. As shown in Figure 8, the roll press apparatus 100B of Embodiment 2 consists of a control unit 101B equipped with a storage unit 102B and a press control unit 104B, a roll press unit 105B, a mark detection sensor 106B, and the like.

[0047] Here, the components that differ significantly from Embodiment 1 are the press control TBL103B and the mark detection sensor 106B. Also, since the current collector has been marked, it will be referred to as the current collector 3 with mark 4.

[0048] The position where mark 4 is placed corresponds to the thin-coated portion, for the same reasoning as in Embodiment 1. Therefore, the position where mark 4 is placed corresponds to the thin-coated portion 32 of the electrode sheet 1 after manufacturing.

[0049] In the press control unit 104B, as shown in Figure 9, a mark item is placed instead of the electrode position item shown in the press control unit 104A. In the example in Figure 9, mark M1 is placed and stored in place of the combination of electrode positions L1 and L2 and the combination of electrode positions L5 and L6, and the correspondence with data such as coating amount is the same. Similarly, mark M2 is placed and stored in place of the combination of electrode positions L3 and L4, and the correspondence with data such as coating amount is the same. This mark can be any information that can determine the press conditions, for example, code information such as a barcode or QR code. For the mark detection sensor 106B, in the case of a barcode, a line sensor or the like can be used as a scanner, and in the case of a QR code, a camera or the like can be used.

[0050] Next, an example of operation will be explained using Figure 10. Steps similar to those in Embodiment 1 described above will be given the same step numbers, and their explanations will be omitted below. In this case as well, the press control unit 104B executes the program to proceed with the process.

[0051] When the pressing process starts in step S72, the mark detection sensor 106B detects a mark from the current collector 3 (step S91), and if mark 4 is detected and determined to be mark M1, the pressing condition 1 corresponding to mark M1 is read out (step S92), and pressing control is executed according to the pressing condition 1 (step S76).

[0052] As described above, according to Embodiment 2, the pressing conditions are changed by detecting marks applied to the sheet-shaped current collector, which have both a normal thick coating area and a thin coating area. Therefore, it is possible to realize a battery electrode structure that suppresses localized battery degradation, similar to the previously described embodiment. In this case, since marks are detected, it is possible to perform press control with higher precision than in Embodiment 1. In other words, it has the effect of suppressing errors in measured values. <Embodiment 3> Next, Embodiment 3 will be described using Figures 11 and 12. Figure 8 shows the function of the roll press apparatus of Embodiment 3.

[0053] Embodiment 3 adds to Embodiment 1 described above the fact that the actual thickness of the manufactured electrode sheet 1 is measured from its finish, and the measurement results are fed back to modify the finished thickness or press conditions of the press control TBL. Of course, when the finished thickness is modified, the press conditions are also modified in conjunction with that modification.

[0054] In this third embodiment, the description of the configuration similar to that of the first embodiment will be omitted, and only the differences will be described. As shown in Figure 11, the roll press apparatus 100C of the third embodiment consists of a control unit 101C equipped with a storage unit 102C and a press control unit 104C, a roll press unit 105C, a position detection sensor 106C, and the like.

[0055] The roll press device 100C is connected to the actual value measuring device 400 as an external device, and the press control unit 104C acquires actual values ​​from the actual value measuring device 400.

[0056] One aspect is that, regarding the finished thickness, if an error is detected in the relationship between the finished thickness stored in the press control TBL103C and the thin-coated or thick-coated portion of the electrode sheet 1, the finished thickness or press conditions are corrected.

[0057] Of course, if an error is detected in the arrangement of the thin-coated and thick-coated portions of the electrode sheet 1 that deviates from a predetermined error range, based on the relationship with the electrode positions stored in the press control TBL103C, the electrode positions may be corrected.

[0058] Next, an example of operation will be explained using Figure 12. Steps similar to those in Embodiment 1 described above will be given the same step numbers, and their explanations will be omitted below. In this case as well, the press control unit 104C executes the program and proceeds with the processing.

[0059] In Figure 12, when press control is performed according to press condition 1 (step S76), measurement is performed by the actual value measuring device 400. Once the actual value (finished thickness) is obtained from the actual value measuring device 400, the error amount of the finished thickness is determined.

[0060] In this case, if the error amount exceeds a predetermined error amount, a determination result is obtained indicating that the press control TBL103C needs to be corrected, while if it is less than or equal to that error amount, a determination result is obtained indicating that the press control TBL103C does not need to be corrected (step S77).

[0061] If the result indicates that a correction is needed (YES route in step S78), the press control information is corrected as described above, and the process returns to step S73 (step S79). If the result indicates that no correction is needed, the process returns to step S73 (NO route in step S78).

[0062] As described above, according to Embodiment 3, the measured values ​​of the electrode sheets manufactured after pressing can be measured, and the press control information of the press control TBL103C can be modified, thereby reducing errors in subsequent pressing processes. In particular, since the press control information can be modified in real time, it is possible to reduce errors during manufacturing. Of course, modifications can be made at regular intervals rather than in real time during manufacturing, or modifications can be made after manufacturing in preparation for the next manufacturing cycle. For example, it can be used as inspection information before proceeding to the next process. Even if the error is large, it does not necessarily mean that the product will be discarded, but it is possible to select which products to use and which to combine based on yield, etc.

[0063] Furthermore, recording areas with large pressing errors allows this information to be used for inspection. This makes sorting before subsequent processes easier.

[0064] In Embodiment 3, the actual measurement device 400 was treated as an external device of the roll press device 100C, but it may also be part of the roll press device 100C. <Embodiment 4> Next, Embodiment 4 will be described using Figures 13 to 15. Figure 13 shows the function of the roll press apparatus of Embodiment 4, and Figure 14 shows an example of the table configuration of Embodiment 4.

[0065] Embodiment 1 showed an example of pressing with a uniform rolling force in a direction intersecting the direction of movement of the current collector, but Embodiment 4 shows an example of pressing with an uneven rolling force in the rightward direction of that intersection.

[0066] In this embodiment 4, the description of the configuration similar to that of embodiment 1 will be omitted, and only the differences will be described. As shown in Figure 13, the roll press device 100D of embodiment 4 is composed of a control unit 101D equipped with a storage unit 102D having a press control TBL 103D and a press control unit 104D, an actuator-type roll press unit 105D, a position detection sensor 106D, and the like.

[0067] The actuator-type roll press section 105D has a structure that applies an uneven rolling force in a direction intersecting the direction of movement of the current collector 2. This rolling force is defined by the press control TBL103D.

[0068] The press control TBL103D defines specifications for each electrode position, as shown in Figure 14, for example. In the case of the press control TBL103A described in Figure 5 of Embodiment 1, electrode positions L1 and L2 located near both ends of the current collector 2 are treated as a pair, and a specification is set to press with a uniform rolling force in a direction intersecting the direction of movement of the current collector 2. In contrast, in Embodiment 4, the press control TBL103C defines different specifications 1 and 2 for electrode positions L1 and L2 located near both ends of the current collector 2 in order to obtain different finished thicknesses with different rolling forces. As a result, a specification is set to press with an uneven rolling force in a direction intersecting the direction of movement of the current collector 2.

[0069] Next, an example of operation according to Embodiment 4 will be explained using Figure 15. Steps similar to those in Embodiment 1 described above will be given the same step numbers, and their explanations will be omitted below. In this case as well, the press control unit 104D executes the program to proceed with the process.

[0070] In Figure 15, the movement position of the current collector 2 is detected (step S73), and the process proceeds to step S95 and beyond until the completion of the pressing process is confirmed (NO route of step S74). When the movement position of the current collector 2 reaches the electrode position defined by the press control TBL103D, the pressing conditions for the corresponding finished thickness for each electrode position are read out (step S95), and the press control is executed (step S76).

[0071] As described above, according to Embodiment 4, in the roll structure, screw-type actuators are used at both ends of the roll to individually control the amount of indentation at the left and right ends of the roll. This allows the press conditions to be changed even for electrodes coated with a gap inclined in the coating width direction. As a result, it becomes possible to set the press conditions according to the positive and negative electrode locations, and to press with a non-uniform rolling force in a direction intersecting the movement direction of the current collector. Of course, a hydraulic system or the like may be applied in addition to the actuator type. <Embodiment 5> Next, Embodiment 5 will be described using Figures 16 and 17. Figure 16 shows the function of the roll press apparatus of Embodiment 5.

[0072] In Embodiment 4, the roll press section 105D had a structure in which rolling was performed by a pair of rolls. However, in Implementation Value 5, the roll press section is arranged in multiple stages, and a structure is shown in which, as in Embodiment 4, the rolling force is applied unevenly in a direction intersecting the direction of movement of the current collector. The actuator system as in Embodiment 4 is not applied, and a system is used in which crown rolls with different bulges in the axial direction of the rolls are arranged in multiple stages. In this case, the bulges between the crown rolls are made different when they are arranged.

[0073] In this embodiment 5, the description of the configurations similar to those in embodiments 1 and 4 will be omitted, and only the differences will be described. As shown in Figure 16, the roll press device 100E of embodiment 5 is composed of a control unit 101E equipped with a storage unit 102E and a press control unit 104E, a multi-stage roll press unit 105E, a position detection sensor 106E, and the like.

[0074] In this embodiment 5, the stepped roll press section 105E has a two-stage structure consisting of a first roll press section 105E1 and a second roll press section 105E2, but it may also have a structure with three or more stages. As defined in embodiment 5, the number of stages shall correspond to the number of locations where the current collector 2 is pressed with an uneven rolling force in a direction intersecting the direction of movement.

[0075] Furthermore, the data configuration for the press control TBL103E is the same as in Figure 14, but an additional data item may be added that defines which roll press section will be used for rolling, corresponding to the electrode position. For example, the first roll press section 105E1 is associated with electrode position L1, and the second roll press section 105E2 is associated with electrode position L2. The press control unit 104E reads this correspondence and determines which roll press section will be used for rolling.

[0076] Next, an example of operation according to Embodiment 5 will be explained using Figure 17. Steps similar to those in Embodiment 1 described above will be given the same step numbers, and their explanations will be omitted below. In this case as well, the press control unit 104E executes the program to proceed with the process.

[0077] In step S95, the press conditions are read out. Here, the electrode positions in a direction intersecting the direction of movement of the current collector 2 are treated as a single set, and the press conditions are read out all at once. That is, in the example in Figure 14, electrode positions L1 and L2 are treated as a single set.

[0078] In the press control unit 104E, first, control is performed to move the current collector 2 to the position of the first roll press unit 105E1, and then press control is performed by the first roll press unit 105E1 (step S96). Subsequently, control is performed to move the current collector 2 to the position of the second roll press unit 105E2, and then press control is performed by the second roll press unit 105E2 (step S97).

[0079] As described above, according to Embodiment 5, for example, the roll section composed of crown rolls is provided in multiple stages, and the structure is such that different rolling forces are applied between the crown rolls. Therefore, similar to Embodiment 4 described above, it is possible to press with an uneven rolling force in a direction intersecting the direction of movement of the current collector.

[0080] In Embodiment 5, a crown roll was applied to the roll section, but other types such as tapered rolls can also be applied, and a combination of crown rolls and tapered rolls is also possible.

[0081] Furthermore, the multi-stage rolls may be configured such that, for example, the first roll section is for rolling the thick coating portion, and the second roll section is for rolling the thin coating portion.

[0082] Furthermore, while the electrode sheet of the rotating body shown in Figure 2 was used as an example in the embodiments described above, the present invention is not limited thereto, and cases that can be folded and stored in a battery, or cases that can be cut and stored, are also provided. In that case as well, the coating thickness and the division into thick-coated and thin-coated areas can be performed by the curvature, and the same processing can be carried out.

[0083] Furthermore, in the embodiments described above, the finished thickness was adjusted using two patterns: a thin-coated section and a thick-coated section. However, the present invention is not limited to this, and the finished thickness may be set to three or more patterns, and the pressing conditions may be increased accordingly.

[0084] Furthermore, although the first embodiment described above used two pairs of electrode positions, the present invention is not limited to this, and may use one electrode position or three or more.

[0085] Furthermore, in the above-described embodiment 1, the position detection sensor 106A was configured to detect the electrode position, but a press control TBL may also be used that detects the thickness of the coated current collector and adjusts the rolling force according to that thickness.

[0086] Generally, when lithium-ion battery electrodes are coated with a wet ink onto the current collector, the viscosity of the mixture slurry changes over time, especially at high alkalinity levels. Therefore, errors occur at the beginning and end of coating, as well as at the edges of the coating width, which deviate from the design specifications. The allowable error for this variation is defined, for example, by the thickness of the mixture after the electrodes have dried. This defined error range applies when the specifications remain constant.

[0087] An electrode plate whose thickness is increased or decreased beyond the specified tolerance range is an electrode plate (current collector) with a pre-press thickness coated with multiple specifications. The roll press apparatus of the present invention makes it possible to set such an electrode plate with multiple specifications to any desired finished thickness. In battery design, the capacity and output change depending on the amount and density of the composite material, i.e., the active material. Since electrodes with intentionally varied coating amounts, or even if the coating amount is constant, the finished thickness and composite density can be changed in parts, it becomes easier to reduce manufacturing defects in batteries and improve performance such as charge and discharge characteristics.

[0088] In the dry process for lithium-ion batteries, the roll press conditions can be applied to the thickness after compound molding and the thickness after pressing. This is applicable not only to lithium-ion batteries but also to processes in which electrode sheets are molded by roll pressing.

[0089] The press conditions in a roll press machine may be determined using a database (DB) that shows the press conditions for each condition specification, such as those shown in Figure 18, in relation to the thickness before and after pressing. Typically, the press conditions are adjusted by changing the thickness of the coated electrode while changing the press pressure, gap, etc., and it is also possible to use a database that accumulates the relationship between the conditions and press pressure during this coating adjustment.

[0090] The simplest configuration involves specifying the thickness before and after pressing, and the press machine settings, in relation to the given conditions. If detailed electrode design information is recorded within the specifications of the conditions, it becomes even easier to use this information to adjust the specifications to values ​​closer to the optimal pressing conditions. The roll press apparatus of the present invention also has the effect of shortening the line start-up period.

[0091] Here, we will describe the electrode composition and pressing conditions in detail using Figure 18. Figure 18 shows DB600, which illustrates the relationship between the electrode composition and pressing conditions. This DB600 is stored in the memory unit described above. DB600 stores the mixture composition, material, mixture weight (kilograms / square meter), density (kilograms / cubic meter), thickness before pressing (micrometers), thickness after pressing (micrometers), and pressing conditions, corresponding to a condition number that distinguishes the conditions.

[0092] In the example in Figure 18, condition numbers "1001" to "1004" correspond to combination composition "Specification 1" and combination weight "W1", condition numbers "1005" and "1006" correspond to combination composition "Specification 2" and combination weight "W2", condition numbers "1007" and "1008" correspond to combination composition "Specification 3" and combination weight "W3", condition numbers "1009" and "1010" correspond to combination composition "Specification 4" and combination weight "W4", and condition numbers "1011" and "1012" correspond to combination composition "Specification 5" and combination weight "W5".

[0093] Furthermore, specifications "1" through "3" correspond to material "Cassertive Compound A," and specifications "4" and "5" correspond to material "Anode Compound B." In addition, densities such as Cd1 through Cd4, Ad1, and Ad2 are associated with each other, regardless of the specification, compound, or weight.

[0094] In Specification 1, for condition numbers "10001" to "10004", the post-press thickness "t1" to "t4" are set for the pre-press thickness "W1a", respectively. The press conditions are set to "a1" to "a4" in corresponding order. Similarly, for condition numbers "1005" to "10012", the press conditions are set to "a5" to "a12", and so on, with the pre-press thickness and post-press thickness being different.

[0095] Electrode specifications define the amount of the mixture to be applied to the electrode surface, which is determined by mixing the electrode active materials (positive electrode active material, negative electrode active material) with conductive materials, binders, and additives in a certain ratio, as the ink specification (mixture composition). The mixture composition is diluted to a certain viscosity, the gap during coating is adjusted, and after coating and drying, the thickness before pressing is determined. If the gap and viscosity are the same, the weight of the mixture will be constant.

[0096] Even if the weight of the mixture is the same, changing the density will change the finished thickness. Therefore, the conditions on the roll press machine are determined using DB600, which links the thickness after pressing with other conditions, to achieve the desired finish. For DB600, the composition of the mixture is used as the unit of specification, but it is sufficient to define the relationship between the specification, the thickness after pressing, and the press conditions of the press machine by including density and thickness before pressing as the unit of specification.

[0097] Typically, the pressing conditions are adjusted by changing the thickness of the coated electrode, as well as the pressing pressure and gap. These conditions for coating adjustment can be accumulated and compiled into a database. In Figure 18, the thickness values ​​after pressing may be the same in some cases, but they are also determined by the specifications of each product. Therefore, all thicknesses are given as individual values, for example, from t1 to t12.

[0098] Each of the above-described configurations, functional units, processing units, and processing means may be implemented in hardware, in whole or in part, for example, by designing them as integrated circuits. Alternatively, each of the above-described configurations and functions may be implemented in software by a processor interpreting and executing programs that realize each function. Information such as programs, tables, and files that realize each function can be stored in memory, hard disks, SSDs (Solid State Drives), or other recording devices, or in recording media such as IC cards, SD cards, or DVDs.

[0099] Furthermore, the arrangement of the various functional units, processing units, and databases described above is merely an example. The arrangement of the various functional units, processing units, and databases can be changed to the optimal arrangement from the standpoint of the performance, processing efficiency, and communication efficiency of the hardware and software of these devices. [Explanation of Symbols]

[0100] 1 Electrode sheet 2, 3 Current collectors 4 marks 100A, 100B, 100C, 100D, 100E Roll Press Machine 101A, 101B, 101C, 101D, 101E Control Unit 102A, 102B, 102C, 102D, 102E Storage section 103A, 103B, 103C, 103D, 103E Press Control Table 104A, 104B, 104C, 104D, 104E Press Control Unit 105A, 105B, 105C, 105E Roll press section 105D Actuator-type roll press section 105E Multi-stage roll press section 105E1 First Roll Press Section 105E2 Second Roll Press Section 106A, 106C, 106D, 106E Position detection sensors 106B Mark Detection Sensor 400 Measurement device for actual values 600 DB

Claims

1. A roll press apparatus for manufacturing electrode sheets to be placed in a battery, wherein a current collector, which is in sheet form and coated with an electrode mixture, is moved and pressed by multiple rolls, The amount of electrode mixture to be applied to each region of the current collector is set according to the arrangement conditions when the electrode sheet is stored, and the storage unit stores the press conditions of the multiple rolls in accordance with the finished thickness of the electrode sheet determined according to the amount of electrode mixture applied. A detection unit for detecting the area of ​​the current collector to be pressed when the current collector moves, A control unit controls the pressing operation of the plurality of rolls against the current collector based on the pressing conditions stored in the storage unit in the region detected by the detection unit, A roll press apparatus characterized by comprising the following features.

2. A roll press apparatus according to claim 1, characterized in that the storage unit sets the press conditions according to the stress applied to the electrode sheets caused by the arrangement of the electrode sheets.

3. A roll press apparatus according to claim 1, characterized in that the storage unit sets different pressing conditions in the vicinity of the battery terminals and in areas other than the vicinity of the terminals, based on the arrangement of the electrode sheets.

4. A roll press apparatus according to claim 1, characterized in that the storage unit is configured to set the press conditions in at least one direction between the direction of movement of the current collector and a direction intersecting the direction of movement.

5. The roll press apparatus according to claim 4, characterized in that the press conditions stored in the memory unit are information for pressing with a uniform force in a direction intersecting the direction of movement of the current collector.

6. A roll press apparatus according to claim 4, characterized in that the press conditions stored in the memory unit are information for pressing with an uneven rolling force in a direction intersecting the direction of movement of the current collector.

7. A roll press apparatus according to claim 1, characterized in that the control unit controls the press in a region in which the amount of coating per unit area of ​​the current collector changes by a larger amount than a certain error range.

8. A roll press apparatus according to claim 1, characterized in that the control unit modifies the finished thickness and press conditions stored in the storage device based on the measured values ​​after manufacturing of the electrode sheet.

9. A roll press apparatus according to claim 1, characterized in that the plurality of rolls are arranged in a multi-stage configuration using a combination of two units.

10. A roll press apparatus for manufacturing electrode sheets to be placed in a battery, wherein a current collector, which is in sheet form and coated with an electrode mixture, is moved and pressed by multiple rolls, The surface of the current collector is marked to specify the pressing conditions corresponding to the finished thickness after pressing with the plurality of rolls, and a storage unit stores the pressing conditions in association with the marks. A detection unit for detecting a mark applied to the current collector before the press, A determination unit that determines the press conditions based on the marks detected by the detection unit by referring to the storage unit, A control unit that controls the pressing operation of the plurality of rolls on the current collector based on the pressing conditions determined by the determination unit, A roll press apparatus characterized by comprising the following features.

11. A roll press control method for an apparatus that manufactures electrode sheets for a battery, which are formed by moving a sheet-like current collector coated with an electrode mixture and pressing it with multiple rolls, A roll press control method characterized in that different amounts of the electrode mixture are set for each region of the current collector according to the arrangement conditions when the electrode sheet is stored, the press conditions of the plurality of rolls are stored in memory in accordance with the finished thickness of the electrode sheet determined according to the amount of the electrode mixture, the region of the current collector to be pressed is detected when the current collector moves, and the press operation of the plurality of rolls on the current collector is controlled in the detected region based on the press conditions stored in memory.

12. A roll press control method for an apparatus that manufactures electrode sheets for a battery, which are formed by moving a sheet-like current collector coated with an electrode mixture and pressing it with multiple rolls, A roll press control method characterized in that the surface of the current collector is marked to specify press conditions corresponding to the finished thickness after pressing with the plurality of rolls, the press conditions are stored in memory in association with the marks, the marks applied to the current collector before pressing are detected, the press conditions are determined based on the detected marks by referring to the memory, and the pressing operation of the plurality of rolls on the current collector is controlled based on the determined press conditions.

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