Electrode sheet manufacturing device

Abstract

The invention provides an electrode sheet manufacturing apparatus. Provided is an electrode sheet manufacturing device which is provided with a pair of rollers for pressing an electrode sheet, and which is capable of controlling the thickness of the electrode sheet. An electrode sheet manufacturing device (10) is provided with: a pair of rollers (61U, 61D) for pressing an electrode active material layer (3) formed on an electrode sheet (1); a pressurized pressure adjustment mechanism (70) that adjusts the pressurized pressure of the pair of rollers (61U, 61D); temperature sensors (91-96) for detecting the surface temperature of at least one of the pair of rollers (61U, 61D); and a control device (100). The control device (100) is configured so as to adjust the pressurization pressure on the basis of the surface temperatures of the rollers (61U, 61D) detected by the temperature sensors (91-96).

Description

Technical Field

[0001] The present invention relates to an apparatus for producing an electrode sheet for an electrical storage device. Background Art

[0002] For example, Japanese Patent Application Publication No. 2006-179401 discloses a pressure roller device that pressurizes a metal web of a secondary battery electrode by continuously passing it between upper and lower pressure rollers. The pressure roller device described in Japanese Patent Application Publication No. 2006-179401 is equipped with an embedded film thickness meter that continuously measures the thickness of the web, and is configured to increase the bending pressure by a predetermined amount each time it is confirmed that the thickness of the web has decreased by a predetermined amount. The bending pressure is a pressure applied in the opposite direction to the pressurization pressure, and by increasing the bending pressure, the gap between the upper and lower pressure rollers is expanded. According to Japanese Patent Application Publication No. 2006-179401, by increasing the bending pressure, it is possible to suppress the gap between the upper and lower pressure rollers from gradually narrowing and the thickness of the web from gradually thinning due to the thermal expansion deformation of the pressure roller.

[0003] The pressurizing roller device disclosed in Japanese Patent Application Publication No. 2006-179401 is equipped with a residual heat roller that heats the web before the pressurizing roller is used. According to Japanese Patent Application Publication No. 2006-179401, as the pressurizing progresses, heat is generated in the bearing portion of the pressurizing roller, and the heat is transferred to the two end regions of the pressurizing roller. According to Japanese Patent Application Publication No. 2006-179401, the web is heated by the preheating roller, so that only the two end regions of the upper and lower pressurizing rollers are corrected for local thermal expansion deformation. As a result, the gap between the upper and lower pressurizing rollers and the pressurizing pressure can be ensured to be approximately uniform in the width direction of the web, and as a result, the thickness deviation in the width direction of the web can be eliminated.

[0004] For example, Japanese Patent Application Publication No. 2013-111647 discloses a rolling device having a thickness gauge for measuring the thickness of a material after compression processing at multiple locations in the width direction. According to Japanese Patent Application Publication No. 2013-111647, by adjusting the pressurizing cylinder position and the bending cylinder pressure according to the thickness of the material measured at multiple locations in the width direction, the thickness of the material can be maintained within a target range regardless of the location in the width direction.

[0005] Japanese Patent Application Publication No. 2014-173996 discloses a roller press machine equipped with a measuring sensor that measures the deformation of the roller by separating the deformation caused by the temperature change of the roller and the deformation caused by the load on the roller. According to Japanese Patent Application Publication No. 2014-173996, the shape change of the roller can be accurately grasped, and the roller can be managed with higher precision.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Publication No. 2006-179401

[0009] Patent Document 2: Japanese Patent Application Publication No. 2013-111647

[0010] Patent Document 3: Japanese Patent Application Publication No. 2014-173996 Summary of the invention

[0011] The above three documents describe the problem that the thickness of the sheet material changes due to the heat generated in the roller bearing portion, the roller thermal expansion deformation. In view of the above problem, in the apparatus described in Japanese Patent Application Publication No. 2006-179401 and Japanese Patent Application Publication No. 2013-111647, it is intended to control the thickness of the sheet material to a target thickness by adjusting the pressing conditions according to the measurement of the thickness of the sheet material after pressurization. In addition, in the apparatus described in Japanese Patent Application Publication No. 2014-173996, it is intended to control the thickness of the sheet material to a target thickness by managing the size of the roller that pressurizes the sheet material.

[0012] The inventors of the present application have found that when an electrode sheet having an electrode active material layer is pressurized, the thickness of the electrode sheet sometimes changes from that immediately after the pressurization. Therefore, when adjusting the pressurization conditions based on the thickness measurement of the electrode sheet, the thickness of the electrode sheet may not be well controlled.

[0013] Here, a device for producing an electrode sheet is proposed which includes a pair of rollers for pressing the electrode sheet and can control the thickness of the electrode sheet.

[0014] The electrode sheet manufacturing device disclosed herein comprises: a pair of rollers for pressurizing an electrode active material layer formed on an electrode sheet; a pressurizing pressure adjusting mechanism for adjusting the pressurizing pressure of the pair of rollers; a temperature sensor for detecting the surface temperature of at least one of the pair of rollers; and a control device. The control device is configured to adjust the pressurizing pressure according to the surface temperature of the roller detected by the temperature sensor.

[0015] According to the electrode sheet manufacturing apparatus described above, the surface temperature of the roller is detected and the pressing pressure of the roller is adjusted according to the detected temperature, thereby making it possible to control the thickness of the electrode sheet. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of an electrode sheet manufacturing apparatus.

[0017] Figure 2 is a schematic side view of a roller press.

[0018] Figure 3 It is a schematic front view of the pressurizing device.

[0019] Figure 4 1 is a flowchart showing a process of controlling the thickness of the electrode sheet under the control of the bending pressure and the cylinder pressurizing pressure.

[0020] Figure 5 This is an example of correlation data between the amount of change in the temperature of the pressure roller and the amount of change in the thickness of the electrode sheet.

[0021] (Explanation of symbols)

[0022] 1: electrode sheet; 2: electrode foil; 3: electrode active material layer; 10: electrode sheet manufacturing device; 20: metering device; 30: kneading device; 40: coating device; 50: drying device; 60: roller press; 60A: unwinding device; 60B: pressurizing device; 60C: winding device; 61D: lower pressurizing roller (roller); 61U: upper pressurizing roller (roller); 62D: roller body (lower side); 62U: roller body (upper side); 63DL: shaft; 63DR: shaft; 63UL: shaft; 63UR: ​​shaft; 70: pressurizing pressure adjustment mechanism; 71D: lower bearing; 71U: upper bearing; 72D: lower axle box; 72U: upper axle box; 73D: lower drive device; 73U: upper drive device ; 74: gap adjustment screw; 75: pressurizing cylinder (lifting device); 76: bending cylinder (bending device); 80: refrigerant supply device; 81: circulation flow path; 82: pump; 83: cooling device; 91: 1st temperature sensor (temperature sensor); 92: 2nd temperature sensor (other temperature sensors); 93: 3rd temperature sensor (temperature sensor); 94: 4th temperature sensor (temperature sensor); 95: 5th temperature sensor (other temperature sensors); 96: 6th temperature sensor (temperature sensor); 100: control device; 101: 1st recording unit; 102: 2nd recording unit; 103: bending pressure control unit; 104: 3rd recording unit; 105: pressurizing pressure control unit; 106: cooling control unit. DETAILED DESCRIPTION

[0023] Hereinafter, an embodiment of a manufacturing apparatus for an electrode sheet of an electrical storage device will be described. It is to be understood that the embodiment described here is not intended to limit the present invention. In addition, each figure is a schematic diagram and does not necessarily faithfully reflect an actual implementation product.

[0024] [Structure of electrode sheet manufacturing apparatus]

[0025] Figure 1FIG. 1 is a schematic diagram of an electrode sheet manufacturing apparatus 10 according to an embodiment. Here, the electrode sheet manufacturing apparatus 10 manufactures an electrode sheet 1 (see FIG. 1 ) of a lithium ion secondary battery. Figure 2 ). However, the electrode sheet 1 is not limited to the electrode sheet 1 of the lithium ion secondary battery, and may also be an electrode sheet of various known power storage devices. Power storage devices are a term for all devices that can extract electrical energy, including so-called storage batteries (chemical batteries) such as lithium ion secondary batteries and nickel-metal hydride batteries, and capacitors (physical batteries) such as electric double layer capacitors.

[0026] The electrode sheet 1 includes a strip-shaped electrode foil 2 and an electrode active material layer 3 formed on the electrode foil 2. The electrode sheet 1 is a component in which an electrode active material layer 3 containing an electrode active material is formed on the surface of a strip-shaped electrode foil 2 of a predetermined width and thickness. In a lithium-ion secondary battery, when the electrode sheet 1 is a positive electrode sheet, the electrode foil 2 is, for example, an aluminum foil. The electrode active material (positive electrode active material) is a material that can release lithium ions during charging and absorb lithium ions during discharging, such as a lithium transition metal composite material. When the electrode sheet 1 is a negative electrode sheet, the electrode foil 2 is, for example, a copper foil. The electrode active material (negative electrode active material) is a material that can absorb lithium ions during charging and release the lithium ions absorbed during discharging, such as natural graphite. Regarding the positive electrode active material and the negative electrode active material, various materials are proposed in addition to the above-mentioned materials, without particular limitation.

[0027] like Figure 1 As shown, the electrode sheet production device 10 includes a weighing device 20 , a kneading device 30 , a coating device 40 , a drying device 50 , and a roll press 60 .

[0028] The measuring device 20 measures the raw materials of the electrode active material layer 3. The measured raw materials of the electrode active material layer 3 are mixed and kneaded by the kneading device 30. The raw materials of the electrode active material layer 3 that are kneaded into a slurry are applied to the electrode foil 2 by the coating device 40. The drying device 50 dries the applied slurry raw materials of the electrode active material layer 3. The roller press 60 presses the electrode sheet 1 to adjust the thickness of the electrode active material layer 3 to a thickness within a predetermined range.

[0029] Figure 2 is a schematic side view of the roller press 60. Figure 2As shown, the roller press 60 involved in this embodiment includes an unwinding device 60A, a pressurizing device 60B, and a winding device 60C. The electrode sheet 1 after the electrode active material layer 3 is dried is supplied to the unwinding device 60A by a roller. The winding device 60C winds up the electrode sheet 1 that is successively drawn out from the unwinding device 60A and pressurized by the pressurizing device 60B. The roller press 60 includes a control device 100 that controls the operation of the unwinding device 60A, the pressurizing device 60B, and the winding device 60C.

[0030] Figure 3 60B is a schematic front view of the pressurizing device 60B. Figure 3 As shown, the pressurizing device 60B comprises: a pair of pressurizing rollers 61U and 61D for pressurizing the electrode active material layer 3 formed on the electrode sheet 1; a pressurizing pressure adjusting mechanism 70 for adjusting the pressurizing pressure of the pair of pressurizing rollers 61U and 61D; a refrigerant supplying device 80 for supplying refrigerant to the pressurizing rollers 61U and 61D; and a plurality of temperature sensors 91 to 96 for detecting the surface temperature of the pressurizing rollers 61U and 61D.

[0031] A pair of pressure rollers 61U and 61D face each other in the thickness direction (in this vertical direction) of the electrode sheet 1. The upper pressure roller 61U has a roller body 62U that contacts and presses the electrode sheet 1. Two shafts 63UL and 63UR are connected on both sides of the roller body 62U. The two shafts 63UL and 63UR are arranged outside the electrode sheet 1 in the width direction and have a smaller diameter than the roller body 62U. The two shafts 63UL and 63UR do not contact the electrode sheet 1. The lower pressure roller 61D also has the same roller body 62D and two shafts 63DL and 63DR.

[0032] The material of the pressure rollers 61U and 61D is not limited, and can be, for example, a material with high hardness such as high carbon bearing steel (SUJ material) or alloy tool steel (SKD material). The size of the pressure rollers 61U and 61D is also not limited, and if large, for example, the diameter is 800 mm and the length is about 1000 mm. For example, the interval between the pressure rollers 61U and 61D made of SUJ2 and having a diameter of 800 mm is calculated to decrease by about 0.01 mm when the temperature rises by 1°C.

[0033] The pressurizing pressure adjustment mechanism 70 comprises: a pair of upper bearings 71U for supporting the upper pressurizing roller 61U; a pair of upper axle boxes 72U for respectively accommodating a pair of upper bearings 71U; a pair of lower bearings 71D for supporting the lower pressurizing roller 61D; a pair of lower axle boxes 72D for respectively accommodating a pair of lower bearings 71D; an upper driving device 73U for rotating the upper pressurizing roller 61U; a lower driving device 73D for rotating the lower pressurizing roller 61D; a pair of gap adjustment screws 74; a pair of pressurizing cylinders 75; and a pair of bending cylinders 76.

[0034] A pair of upper bearings 71U rotatably support the two shaft portions 63UL and 63UR of the upper pressure roller 61U, respectively. When the upper pressure roller 61U is rotated while applying a pressure, heat is generated due to the friction between the two shaft portions 63UL and 63UR of the upper pressure roller 61U and the pair of upper bearings 71U. The influence of this heat will be described later. The upper axle box 72U on one side also houses a transmission component (not shown) connected to the upper drive device 73U and a transmission component (not shown) on the other side that is connected to the shaft portion (for example, 63UR) of one side of the upper pressure roller 61U and engages with the above-mentioned transmission component. The upper drive device 73U is, for example, an electric motor. The two transmission components are, for example, gears.

[0035] A pair of lower bearings 71D rotatably supports the two shaft portions 63DL and 63DR of the lower pressure roller 61D. A transmission component (not shown) connected to the lower drive device 73D and a transmission component (not shown) on the other side connected to one shaft portion (e.g., 63DR) of the lower pressure roller 61D are housed in the lower shaft box 72D.

[0036] The pair of gap adjustment screws 74 adjust the vertical position of the upper pressure roller 61U. By rotating the gap adjustment screws 74, the gap between the upper pressure roller 61U and the lower pressure roller 61D can be adjusted. However, the gap adjustment screws 74 may be removed, and in this case, the gap between the upper pressure roller 61U and the lower pressure roller 61D can be adjusted by the operation of the pressure cylinder 75.

[0037] A pair of pressurizing cylinders 75 press the lower pressurizing roller 61D toward the upper pressurizing roller 61U. The pair of pressurizing cylinders 75 support a pair of lower bearings 71D so that they can move in the up-down direction. The electrode sheet 1 sandwiched by the pair of pressurizing rollers 61U and 61D is pressurized by driving the pair of pressurizing cylinders 75. The pair of pressurizing cylinders 75 is one of the devices for adjusting the pressurizing pressure for pressurizing the electrode sheet 1. In the present embodiment, "pressurizing pressure" refers to the synthetic pressure of the bending pressure described later and the pressure generated by the pressurizing cylinder 75. Hereinafter, in order to distinguish it from "pressurizing pressure", the pressure generated by the pressurizing cylinder 75 is also referred to as "cylinder pressurizing pressure". In addition, the pressurizing cylinder 75 is an example of a lifting device for lifting one side of a pair of pressurizing rollers 61U and 61D relative to the other side. By driving the pressurizing cylinder 75, the gap between the pair of pressurizing rollers 61U and 61D can also be adjusted together with the cylinder pressurizing pressure. The lifting device may be configured to press the upper pressure roller 61U toward the lower pressure roller 61D. Alternatively, the lifting device may be configured to lower the upper pressure roller 61U and raise the lower pressure roller 61D.

[0038] The pair of bending cylinders 76 is also one of the devices for adjusting the pressure of the pressure device 60B. The pair of bending cylinders 76 are arranged between the shaft portion 63UL of the upper pressure roller 61U and the shaft portion 63DL of the lower pressure roller 61D and between the shaft portion 63UR of the upper pressure roller 61U and the shaft portion 63DR of the lower pressure roller 61D. The pair of bending cylinders 76 press the pressure rollers 61U and 61D in the direction opposite to the pressure provided by the pressure cylinder 75. As a result, the pressure rollers 61U and 61D are bent or the bending is corrected. As a result, the gap and the pressure between the pressure rollers 61U and 61D are adjusted. By independently controlling the bending pressure with the left and right bending cylinders 76, the gap and the pressure between the pressure rollers 61U and 61D are adjusted on the left and right. The pair of bending cylinders 76 is an example of a bending device for bending the pressure rollers 61U and 61D. Here, “bending the pressure rollers 61U, 61D” may include bending the pressure rollers 61U, 61D to correct the bent pressure rollers 61U, 61D by driving the pressure cylinder 75. The pair of bending cylinders 76 are configured to be able to adjust the bending pressure for bending the pressure rollers 61U, 61D.

[0039] The refrigerant supply device 80 supplies refrigerant to a pair of upper shaft boxes 72U and a pair of lower shaft boxes 72D. The refrigerant circulates in four circulation paths 81, each of which includes an upper shaft box 72U on one side, an upper shaft box 72U on the other side, a lower shaft box 72D on one side, and a lower shaft box 72D on the other side. A pump 82 and a cooling device 83 are provided in each circulation path 81. The refrigerant circulates in the circulation path 81 driven by the pump 82, and absorbs heat from the bearing 71U or 71D when passing through the bearing 71U or 71D. As a result, the refrigerant with a rising temperature is cooled by the cooling device 83. The pump 82 is configured to be able to adjust the circulation speed of the refrigerant. The refrigerant supply device 80 adjusts the circulation speed of the refrigerant by controlling the pump 82, and adjusts the amount of refrigerant supplied to the shaft boxes 72U and 72D (the amount per unit time).

[0040] A plurality of temperature sensors 91 to 93 (hereinafter also referred to as the first temperature sensor 91 to the third temperature sensor 93) detect the surface temperature of the upper pressure roller 61U. Here, the first temperature sensor 91 to the third temperature sensor 93 are arranged above the upper pressure roller 61U. The first temperature sensor 91 to the third temperature sensor 93 are separated from the upper pressure roller 61U. The first temperature sensor 91 to the third temperature sensor 93 are non-contact temperature sensors, such as infrared temperature sensors. However, the first temperature sensor 91 to the third temperature sensor 93 may also be a contact temperature sensor. In addition, the first temperature sensor 91 to the third temperature sensor 93 may also be arranged in front of, behind, or at other positions of the upper pressure roller 61U.

[0041] The first temperature sensor 91 is disposed at the leftmost position among the first temperature sensor 91 to the third temperature sensor 93, and detects the surface temperature of the left end portion of the upper pressure roller 61U. The second temperature sensor 92 is disposed at the right of the first temperature sensor 91, and detects the surface temperature of the center portion of the upper pressure roller 61U. The third temperature sensor 93 is disposed at the rightmost position among the first temperature sensor 91 to the third temperature sensor 93, and detects the surface temperature of the right end portion of the upper pressure roller 61U. Here, the "end portion" of the upper pressure roller 61U refers to the substantial end portion of the pressure roller 61U, that is, the end portion of the roller body 62U. The "end portion" of the upper pressure roller 61U is, for example, the region at both ends when the roller body 62U is divided into three equal parts in the axial direction. In addition, the "center portion" of the upper pressure roller 61U is, for example, the region in the middle when the roller body 62U is divided into three equal parts in the axial direction. "Detecting the temperature of the end portion or the center portion" means measuring the temperature of at least one point in the end portion or the center portion.

[0042] A plurality of temperature sensors 94 to 96 (hereinafter also referred to as the fourth temperature sensor 94 to the sixth temperature sensor 96) detect the surface temperature of the lower pressure roller 61D. Here, the fourth temperature sensor 94 to the sixth temperature sensor 96 are arranged below the lower pressure roller 61D. However, the fourth temperature sensor 94 to the sixth temperature sensor 96 may be arranged in front of, behind, or at other positions of the lower pressure roller 61D. The fourth temperature sensor 94 to the sixth temperature sensor 96 are also non-contact temperature sensors.

[0043] The fourth temperature sensor 94 is disposed at the leftmost position among the fourth temperature sensor 94 to the sixth temperature sensor 96, and detects the surface temperature of the left end portion of the lower pressure roller 61D (roller body portion 62D). The fifth temperature sensor 95 is disposed to the right of the fourth temperature sensor 94, and detects the surface temperature of the center portion of the lower pressure roller 61D (roller body portion 62D). The sixth temperature sensor 96 is disposed at the rightmost position among the fourth temperature sensor 94 to the sixth temperature sensor 96, and detects the surface temperature of the right end portion of the lower pressure roller 61D (roller body portion 62D).

[0044] The control device 100 is configured to adjust the pressing pressure according to the surface temperature of the pressing rollers 61U and 61D detected by the temperature sensors 91 to 96. Here, the control device 100 adjusts the bending pressure of the bending cylinder 76 to bend the pressing rollers 61U and 61D according to the temperature detected by the temperature sensors 91 to 96. In detail, the control device 100 pre-records the correlation data between the temperature detected by the temperature sensors 91 to 96 and the thickness of the electrode sheet 1. The control device 100 adjusts the bending pressure of the bending cylinder 76 to bend the pressing rollers 61U and 61D according to the above correlation data. The control device 100 also pre-records the correlation data between the change in the bending pressure and the change in the thickness of the electrode sheet 1. The control device 100 reduces the difference in thickness based on the position in the width direction of the electrode sheet 1 by adjusting the bending pressure, thereby making the thickness uniform.

[0045] like Figure 2 As shown, the control device 100 includes: a first recording unit 101 for recording correlation data between the temperature detected by the temperature sensors 91 to 96 and the thickness of the electrode sheet 1; and a second recording unit 102 for recording correlation data between the amount of change in bending pressure and the amount of change in the thickness of the electrode sheet 1. In addition, the control device 100 includes a bending pressure control unit 103 for adjusting the bending pressure of the bending cylinder 76 for bending the pressure rollers 61U and 61D based on the correlation data recorded in the first recording unit 101 and the correlation data recorded in the second recording unit 102.

[0046] The thickness of the electrode sheet 1 of the above-mentioned related data is measured after the pressing process is completed. The thickness of the electrode sheet 1 may increase compared to just after the pressing process, for example, due to the rebound of the electrode sheet 1. Therefore, the gap between the upper pressing roller 61U and the lower pressing roller 61D and the thickness of the electrode sheet 1 after the pressing process may be different. Therefore, the above-mentioned related data are prepared based on the thickness of the electrode sheet 1 measured after the pressing process is completed.

[0047] In addition, the control device 100 controls the pressurizing cylinder 75 according to the temperature detected by the temperature sensors 91 to 96 to adjust the pressurizing pressure. In detail, the control device 100 performs the above control according to the correlation data between the temperature detected by the temperature sensors 91 to 96 and the thickness of the electrode sheet 1. Thus, the control device 100 makes the thickness of each part of the electrode sheet 1 in the width direction within a predetermined range. The control device 100 also pre-records the correlation data between the change in the cylinder pressurizing pressure and the change in the electrode sheet 1. Figure 2 As shown, the control device 100 comprises: a third recording unit 104 for recording correlation data between changes in cylinder pressurization pressure and changes in thickness of the electrode sheet 1; and a pressurization pressure control unit 105 for controlling the pressurization cylinder 75 according to the temperature detected by the temperature sensors 91 to 96 to adjust the cylinder pressurization pressure.

[0048] Furthermore, the control device 100 adjusts the amount of refrigerant supplied from the refrigerant supply device 80 according to the temperature detected by the temperature sensors 91 to 96. Specifically, the control device 100 controls the plurality of pumps 82 to adjust the supply speed of the refrigerant. Figure 2 As shown, the control device 100 includes a cooling control unit 106 that controls the pump 82 based on the temperature detected by the temperature sensors 91 to 96 and adjusts the amount of refrigerant supplied from the refrigerant supply device 80. Thus, the control device 100 makes the temperature of the pressure rollers 61U and 61D close to a predetermined temperature and reduces the temperature difference based on the location of the pressure rollers 61U and 61D. Here, the control device 100 controls each pump 82 independently.

[0049] [Thickness control of electrode sheet]

[0050] An example of thickness control of the electrode sheet 1 using the roller press 60 is described below. In order to facilitate thickness control of the electrode sheet 1, the roller press 60 suppresses the temperature rise of the pressure rollers 61U and 61D by allowing a refrigerant to flow. When the temperature of the pressure rollers 61U and 61D rises, the pressure rollers 61U and 61D thermally expand, and the gap between them narrows. As a result, the thickness of the electrode sheet 1 becomes thinner. By suppressing the temperature rise of the pressure rollers 61U and 61D, the thickness of the electrode sheet 1 can be suppressed from becoming thinner. When the temperature of the pressure rollers 61U and 61D rises, the roller press 60 increases the supply of the refrigerant. When the temperature of the pressure rollers 61U and 61D rises despite cooling, the roller press 60 controls the thickness of the electrode sheet 1 by controlling the bending pressure and the cylinder pressure.

[0051] Figure 4 FIG. 1 is a flow chart showing the process of controlling the thickness of the electrode sheet 1 under the control of the bending pressure and the cylinder pressurizing pressure. Figure 4 As shown, in step S01 of controlling the thickness of the electrode sheet 1, the roller press machine 60 obtains the temperatures of the left end portions of the pressure rollers 61U and 61D respectively measured by the first temperature sensor 91 and the fourth temperature sensor 94. In step S02, the thickness of the left end portion of the electrode sheet 1 is estimated based on the obtained temperatures of the left end portions of the pressure rollers 61U and 61D and the relevant data recorded in the first recording unit 101. Figure 5 This is an example of correlation data between the temperature and the thickness of the electrode sheet 1, more specifically, between the amount of change in the temperature of the pressure rollers 61U and 61D and the amount of change in the thickness of the electrode sheet 1. Figure 5 As shown, as the temperature of the pressure rollers 61U and 61D increases, the estimated thickness of the electrode sheet 1 decreases. Here, as the temperature of the left end of the pressure rollers 61U and 61D increases, the estimated thickness of the left end of the electrode sheet 1 decreases.

[0052] In step S03, the roller press machine 60 obtains the temperature of the right end of the pressure rollers 61U and 61D measured by the third temperature sensor 93 and the sixth temperature sensor 96, respectively, in the same manner as the left end. In the following step S04, based on the obtained temperature of the right end of the pressure rollers 61U and 61D, the thickness of the right end of the electrode sheet 1 is estimated based on the relevant data recorded in the first recording unit 101. As the temperature of the right end of the pressure rollers 61U and 61D rises, the estimated thickness of the right end of the electrode sheet 1 becomes thinner.

[0053] In step S05, the roller press 60 obtains the temperature of the central portion of the pressure rollers 61U and 61D measured by the second temperature sensor 92 and the fifth temperature sensor 95, respectively. In step S06, the thickness of the central portion of the electrode sheet 1 is estimated based on the obtained temperature of the central portion of the pressure rollers 61U and 61D and the relevant data recorded in the first recording unit 101. Heat generation is mainly caused by friction between the pressure rollers 61U and 61D and the bearings 71U and 71D. Therefore, the temperature of the central portion of the pressure rollers 61U and 61D is usually lower than the temperature of the two end portions. The estimated thickness of the central portion of the electrode sheet 1 is usually thicker than the estimated thickness of the two end portions. In addition, the order of the group of steps S01 and S02, the group of steps S03 and S04, and the group of steps S05 and S06 can also be reversed.

[0054] In step S07, the roller press 60 obtains the difference between the estimated thickness of the left end portion and the thickness of the central portion of the electrode sheet 1. In step S08, the bending pressure of the bending cylinder 76 on the left side is adjusted in a manner to eliminate the difference obtained in step S07 based on the relevant data recorded in the second recording unit 102. The greater the difference between the estimated thickness of the left end portion and the thickness of the central portion of the electrode sheet 1, the greater the bending pressure is set. Similarly, in step S09, the difference between the estimated thickness of the right end portion and the thickness of the central portion of the electrode sheet 1 is obtained. In step S10, the bending pressure of the bending cylinder 76 on the right side is adjusted in a manner to eliminate the difference obtained in step S09 based on the relevant data recorded in the second recording unit 102.

[0055] Furthermore, in step S11, the difference between the thickness of the central portion of the electrode sheet 1 estimated in step S06 and the predetermined target value of the thickness of the central portion is obtained. In step S12, the cylinder pressurization pressure of the pressurization cylinder 75 is adjusted in a manner to eliminate the difference with the above-mentioned target value based on the relevant data recorded in the third recording unit 104. The thinner the estimated thickness of the central portion of the electrode sheet 1, the smaller the cylinder pressurization pressure is set. Although omitted in the figure, for example, steps S01 to S12 are repeated at predetermined time intervals. In addition, the order of the group of steps S07 and S08, the group of steps S09 and S10, and the group of steps S11 and S12 can also be reversed.

[0056] [Effects of the Embodiments]

[0057] Hereinafter, the effects that can be achieved by the manufacturing apparatus 10 of the electrode sheet 1 according to the present embodiment will be described.

[0058] The manufacturing device 10 of the electrode sheet 1 according to the present embodiment includes: a pair of pressurizing rollers 61U and 61D for pressurizing the electrode active material layer 3 formed on the electrode sheet 1; a pressurizing pressure adjusting mechanism 70 for adjusting the pressurizing pressure of the pair of pressurizing rollers 61U and 61D; temperature sensors 91 to 96 for detecting the surface temperature of the pair of pressurizing rollers 61U and 61D; and a control device 100. The control device 100 is configured to adjust the pressurizing pressure according to the surface temperature of the pressurizing rollers 61U and 61D detected by the temperature sensors 91 to 96. In addition, the temperature sensor may detect the surface temperature of at least one of the pair of pressurizing rollers 61U and 61D.

[0059] According to the manufacturing apparatus 10 of the electrode sheet 1 described above, the thickness of the electrode sheet 1 can be controlled by detecting the surface temperature of the pressing rollers 61U and 61D and adjusting the pressing pressure of the pressing rollers 61U and 61D according to the detected temperature.

[0060] In conventional roller presses, it is intended to deal with the problem of thickness variation of the electrode sheet due to heat generated in the bearing portion of the pressurizing roller by measuring the thickness of the electrode sheet after pressurization. Specifically, in conventional roller presses, it is intended to control the thickness of the electrode sheet to a target thickness by performing feedback control on the pressurization pressure based on the measurement of the thickness of the electrode sheet after pressurization. However, the inventors of the present application have discovered that when pressurization is applied to an electrode sheet having at least an electrode active material layer formed thereon, the thickness of the electrode sheet sometimes changes from that immediately after pressurization, for example, due to the rebound of the electrode sheet. Therefore, when adjusting the pressurization pressure based on the measurement of the thickness of the electrode sheet, there may be a situation where the thickness of the electrode sheet cannot be well controlled.

[0061] In the manufacturing device 10 of the electrode sheet 1 according to the present embodiment, the thickness of the electrode sheet 1 after pressing is estimated based on the surface temperature of the pressing rollers 61U and 61D, and the pressing pressure of the pressing rollers 61U and 61D is adjusted. Therefore, even in the case where the thickness of the electrode sheet 1 changes from that immediately after pressing, the thickness of the electrode sheet 1 can be controlled.

[0062] In the present embodiment, the pressure adjustment mechanism 70 includes a bending cylinder 76 for bending the pressure rollers 61U and 61D. The control device 100 adjusts the bending pressure of the bending cylinder 76 for bending the pressure rollers 61U and 61D according to the temperature detected by the temperature sensors 91 to 96. According to the above structure, by bending the pressure rollers 61U and 61D, it is possible to suppress the partial change in the thickness of the electrode sheet 1 (here, the thickness becomes thinner at both ends of the electrode sheet 1).

[0063] The manufacturing device 10 of the electrode sheet 1 according to the present embodiment further includes a refrigerant supply device 80 for supplying refrigerant to the pressure rollers 61U and 61D. The control device 100 adjusts the amount of refrigerant supplied from the refrigerant supply device 80 according to the temperature detected by the temperature sensors 91 to 96. According to the above structure, the temperature rise of the pressure rollers 61U and 61D can be suppressed. Thus, the thickness of the electrode sheet 1 can be suppressed from being reduced.

[0064] In this embodiment, the pressure adjustment mechanism 70 includes a pressure cylinder 75 that raises and lowers one of the pair of pressure rollers 61U and 61D relative to the other (here, the lower pressure roller 61D is raised and lowered). The control device 100 controls the pressure cylinder 75 according to the temperature detected by the temperature sensors 91 to 96 to adjust the pressure. According to the above structure, the thickness of the electrode sheet 1 can be controlled simultaneously over the entire width.

[0065] In the present embodiment, the control device 100 records in advance the correlation data between the temperature detected by the temperature sensors 91 to 96 and the thickness of the electrode sheet 1. The control device 100 controls the pressurizing pressure adjusting mechanism 70 based on the correlation data. According to the above structure, the pressurizing pressure adjusting mechanism 70 is controlled based on the correlation data between the temperature detected by the temperature sensors 91 to 96 and the thickness of the electrode sheet 1. Therefore, even in the case where the thickness of the electrode sheet 1 changes from immediately after pressurization, the thickness of the electrode sheet 1 can be controlled.

[0066] In more detail, the manufacturing device 10 of the electrode sheet 1 according to the present embodiment includes the first temperature sensor 91 to the sixth temperature sensor 96. The first temperature sensor 91 and the fourth temperature sensor 94 detect the temperature of the left end of the pressure rollers 61U and 61D, and the second temperature sensor 92 and the fifth temperature sensor 95 detect the temperature of the center of the pressure rollers 61U and 61D. In addition, the third temperature sensor 93 and the sixth temperature sensor 96 detect the temperature of the right end of the pressure rollers 61U and 61D. According to the above structure, the temperature of the end and the temperature of the center of the pressure rollers 61U and 61D are measured, so that the thickness of the end and the thickness of the center in the width direction of the electrode sheet 1 can be controlled together. More specifically, the control device 100 adjusts the bending pressure of the bending cylinder 76 to bend the pressure rollers 61U and 61D based on the recorded correlation data. As a result, the difference in thickness between the end and the center of the pressure rollers 61U and 61D in the width direction of the electrode sheet 1 caused by the temperature difference between the end and the center can be suppressed. The difference in thickness between the left and right ends of the electrode sheet 1 caused by the temperature difference between the left and right ends of the pressure rollers 61U and 61D is also suppressed.

[0067] In the present embodiment, the temperature sensors 91 to 96 are non-contact temperature sensors. According to the above structure, there is no possibility that the surface of the pressure rollers 61U and 61D is damaged due to contact with the temperature sensors. There is no possibility that foreign matter generated thereby is mixed into the electrode sheet 1, thereby reducing the quality of the electrode sheet 1. In addition, since there is no such possibility, the pressure rollers 61U and 61D can be rotated at a high speed. As a result, the productivity of the electrode sheet 1 can be improved.

[0068] [Other embodiments]

[0069] The above describes one embodiment of the manufacturing device of the electrode sheet proposed herein. However, the above embodiment is only an example and can be implemented in other ways. For example, in the above embodiment, the pressurizing pressure is controlled by controlling the pressurizing cylinder 75 and the bending cylinder 76, but it is not limited to this. For example, the pressurizing pressure can also be controlled by controlling one or more pressurizing cylinders.

[0070] In the above embodiment, the refrigerant supply device 80 is provided, but it may not be provided if possible.

[0071] In addition, the above-mentioned embodiments do not limit the present invention except for the cases mentioned in particular. In addition, the technology disclosed herein can be modified in various ways, and each component and each process mentioned herein can be appropriately omitted or appropriately combined as long as no particular problem occurs.

[0072] This specification includes the disclosure of the following items.

[0073] Item 1:

[0074] An electrode sheet manufacturing device, comprising:

[0075] a pair of rollers for pressurizing the electrode active material layer formed on the electrode sheet;

[0076] A pressing pressure adjustment mechanism for adjusting the pressing pressure of the pair of rollers;

[0077] a temperature sensor for detecting a surface temperature of at least one of the pair of rollers; and

[0078] Control device,

[0079] The control device is configured to adjust the pressing pressure based on the surface temperature of the roller detected by the temperature sensor.

[0080] Item 2:

[0081] The electrode sheet manufacturing device according to item 1, wherein

[0082] The pressing pressure adjustment mechanism includes a bending device for bending the roller,

[0083] The control device adjusts a bending pressure with which the bending device bends the roller, based on the temperature detected by the temperature sensor.

[0084] Item 3:

[0085] The electrode sheet manufacturing device according to item 1 or 2, wherein:

[0086] further comprising a refrigerant supply device for supplying a refrigerant to the roller,

[0087] The control device adjusts the amount of refrigerant supplied from the refrigerant supply device according to the temperature detected by the temperature sensor.

[0088] Item 4:

[0089] The electrode sheet manufacturing device according to any one of items 1 to 3, wherein

[0090] The pressurizing pressure adjustment mechanism includes a lifting device for lifting one of the pair of rollers relative to the other.

[0091] The control device controls the lifting device according to the temperature detected by the temperature sensor to adjust the pressurizing pressure.

[0092] Item 5:

[0093] The electrode sheet manufacturing device according to any one of items 1 to 4, wherein

[0094] In the control device, correlation data between the temperature detected by the temperature sensor and the thickness of the electrode sheet is pre-recorded.

[0095] The control device controls the pressurization pressure adjustment mechanism according to the relevant data.

[0096] Item 6:

[0097] The electrode sheet manufacturing device according to any one of items 1 to 5, wherein

[0098] The temperature sensor is a non-contact temperature sensor.

[0099] Item 7:

[0100] The electrode sheet manufacturing device according to any one of items 1 to 6, wherein

[0101] There are other temperature sensors,

[0102] One of the temperature sensor and the other temperature sensor detects the temperature of the end portion of the roller.

[0103] The other of the temperature sensor and the other temperature sensor detects a temperature of a center portion of the roller.

[0104] Item 8:

[0105] The electrode sheet manufacturing device according to item 7, wherein:

[0106] The pressing pressure adjustment mechanism includes a bending device for bending the roller,

[0107] In the control device, correlation data between the temperature detected by the temperature sensor or the other temperature sensor and the thickness of the electrode sheet is pre-recorded,

[0108] The control device adjusts the bending pressure of the bending device to bend the roller according to the relevant data.

Claims

1. An electrode sheet manufacturing device, comprising: a pair of rollers for pressurizing the electrode active material layer formed on the electrode sheet; A pressing pressure adjustment mechanism for adjusting the pressing pressure of the pair of rollers; a temperature sensor for detecting a surface temperature of at least one of the pair of rollers; and Control device, The control device is configured to adjust the pressing pressure based on the surface temperature of the roller detected by the temperature sensor.

2. The electrode sheet manufacturing device according to claim 1, in, The pressing pressure adjustment mechanism includes a bending device for bending the roller, The control device adjusts a bending pressure with which the bending device bends the roller, based on the temperature detected by the temperature sensor.

3. The electrode sheet manufacturing device according to claim 1, in, further comprising a refrigerant supply device for supplying a refrigerant to the roller, The control device adjusts the amount of refrigerant supplied from the refrigerant supply device according to the temperature detected by the temperature sensor.

4. The electrode sheet manufacturing device according to claim 1, in, The pressurizing pressure adjustment mechanism includes a lifting device for lifting one of the pair of rollers relative to the other. The control device controls the lifting device according to the temperature detected by the temperature sensor to adjust the pressurizing pressure.

5. The electrode sheet manufacturing device according to claim 1, in, In the control device, correlation data between the temperature detected by the temperature sensor and the thickness of the electrode sheet is pre-recorded. The control device controls the pressurization pressure adjustment mechanism according to the relevant data.

6. The electrode sheet manufacturing device according to claim 1, in, The temperature sensor is a non-contact temperature sensor.

7. The electrode sheet manufacturing device according to claim 1, in, There are also other temperature sensors, One of the temperature sensor and the other temperature sensor detects the temperature of the end portion of the roller. The other of the temperature sensor and the other temperature sensor detects a temperature of a center portion of the roller.

8. The electrode sheet manufacturing device according to claim 7, in, The pressing pressure adjustment mechanism includes a bending device for bending the roller, In the control device, correlation data between the temperature detected by the temperature sensor or the other temperature sensor and the thickness of the electrode sheet is pre-recorded, The control device adjusts the bending pressure of the bending device to bend the roller according to the relevant data.

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