Electrode sheet manufacturing device

Abstract

To provide an electrode sheet manufacturing device that comprises a pair of rolls for pressing an electrode sheet and can control the thickness of the electrode sheet.SOLUTION: An electrode sheet manufacturing device comprises: a pair of rolls 61U, 61D that presses an electrode active material layer formed on an electrode sheet; a pressing pressure adjustment mechanism 70 that adjusts the pressing pressure of the pair of rolls 61U, 61D; temperature sensors 91 to 96 that detect a surface temperature of at least one roll of the pair of rolls 61U, 61D; and a control unit. The control unit is configured to adjust the pressing pressure on the basis of the surface temperature of the rolls 61U, 61D detected by the temperature sensors 91 to 96.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an electrode sheet manufacturing apparatus for an electricity storage device. [Background technology]

[0002] For example, Patent Document 1 discloses a press roll device that continuously passes a metal web of a secondary battery electrode between upper and lower press rolls to press it. The press roll device described in Patent Document 1 is equipped with an in-line 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 pressing pressure, and by increasing the bending pressure, the gap between the upper and lower press rolls widens. According to Patent Document 1, by increasing the bending pressure, it is possible to suppress the gap between the upper and lower press rolls from gradually narrowing due to thermal expansion deformation of the press roll, and the thickness of the web from gradually becoming thinner.

[0003] The press roll device disclosed in Patent Document 1 includes a preheat roll that heats the web before pressing with the press roll. According to Patent Document 1, as pressing progresses, heat is generated in the bearing of the press roll, and the heat is transferred to both end regions of the press roll. According to Patent Document 1, since the web is heated by the preheat roll, local thermal expansion and deformation only in both end regions of the upper and lower press rolls is corrected. This makes it possible to keep the gap between the upper and lower press rolls and the press pressure almost uniform in the width direction of the web, and as a result, it is possible to eliminate thickness variations in the width direction of the web.

[0004] For example, Patent Document 2 discloses a roll press facility equipped with a thickness gauge that measures the thickness of a compressed material at multiple locations in the width direction. According to Patent Document 2, it is possible to maintain the thickness of the material within a target range at any position in the width direction by adjusting the press cylinder position and the bend cylinder pressure based on the thickness of the material measured at multiple locations in the width direction.

[0005] Patent Document 3 discloses a roll press facility equipped with a measurement sensor that measures the amount of roll deformation by dividing the deformation by roll temperature change and the deformation by roll load. According to Patent Document 3, it is possible to accurately grasp the change in roll shape, and more precise management of the rolls is possible. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2006-179401 A [Patent Document 2] JP 2013-111647 A [Patent Document 3] JP 2014-173996 A Summary of the Invention [Problem to be solved by the invention]

[0007] Patent documents 1 to 3 describe a problem that the rolls are thermally expanded and deformed by heat generated at the bearings of the rolls, causing a change in the thickness of the sheet material. In response to this problem, the devices described in Patent documents 1 and 2 attempt to control the thickness of the sheet material to a target thickness by adjusting the pressing conditions based on the measurement of the thickness of the sheet material after pressing. In addition, the device described in Patent document 3 attempts to control the thickness of the sheet material to a target thickness by controlling the dimensions of the rolls that press the sheet material.

[0008] The inventors of the present application found that when an electrode sheet on which an electrode active material layer is formed is pressed, the thickness of the electrode sheet may change from that immediately after pressing. Therefore, if the pressing conditions are adjusted based on the measurement of the thickness of the electrode sheet, there may be cases where the thickness of the electrode sheet cannot be controlled well.

[0009] Here, an electrode sheet manufacturing apparatus is proposed which is equipped with a pair of rolls that press the electrode sheet and is capable of controlling the thickness of the electrode sheet. [Means for solving the problem]

[0010] The electrode sheet manufacturing apparatus disclosed herein includes a pair of rolls for pressing an electrode active material layer formed on an electrode sheet, a press pressure adjustment mechanism for adjusting the press pressure of the pair of rolls, a temperature sensor for detecting the surface temperature of at least one of the pair of rolls, and a control device, the control device being configured to adjust the press pressure based on the surface temperature of the roll detected by the temperature sensor.

[0011] According to the electrode sheet manufacturing apparatus, the surface temperature of the roll is detected, and the pressing pressure of the roll is adjusted based on the detected temperature, thereby making it possible to control the thickness of the electrode sheet. [Brief description of the drawings]

[0012] [Figure 1] FIG. 2 is a schematic diagram of an electrode sheet manufacturing apparatus. [Diagram 2] FIG. 2 is a schematic side view of a roll press machine. [Diagram 3] FIG. 2 is a schematic front view of a press device. [Figure 4] 10 is a flowchart showing a process of controlling the thickness of an electrode sheet by controlling a bending pressure and a cylinder press pressure. [Diagram 5] 13 is an example of correlation data between the amount of change in temperature of a press roll and the amount of change in thickness of an electrode sheet. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, one embodiment of the manufacturing apparatus for electrode sheets of electricity storage devices will be described. Note that the embodiment described here is, of course, not intended to limit the present invention in particular. Also, each figure is a schematic diagram and does not necessarily faithfully reflect an actual product.

[0014] [Configuration of electrode sheet manufacturing equipment] Fig. 1 is a schematic diagram of an electrode sheet manufacturing apparatus 10 according to one embodiment. Here, the electrode sheet manufacturing apparatus 10 manufactures an electrode sheet 1 (see Fig. 2) for a lithium ion secondary battery. However, the electrode sheet 1 is not limited to the electrode sheet 1 for a lithium ion secondary battery, and may be an electrode sheet for various known electricity storage devices. The term "electricity storage device" refers to devices in general that can extract electric energy, and includes 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.

[0015] 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 member in which the electrode active material layer 3 containing an electrode active material is formed on the surface of the strip-shaped electrode foil 2 having 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 charging and discharge the lithium ions absorbed during discharging, such as natural graphite. The positive electrode active material and the negative electrode active material are not particularly limited, and various materials other than those mentioned above have been proposed.

[0016] As shown in FIG. 1, the electrode sheet manufacturing apparatus 10 includes a measuring device 20, a kneading device 30, a coating device 40, a drying device 50, and a roll press machine 60.

[0017] The measuring device 20 measures the raw materials for the electrode active material layer 3. The measured raw materials for the electrode active material layer 3 are mixed and kneaded by the kneading device 30. The raw materials for the electrode active material layer 3, which have been kneaded into a slurry form, are applied to the electrode foil 2 by the coating device 40. The drying device 50 dries the applied raw materials for the electrode active material layer 3 in the form of a slurry. The roll press machine 60 presses the electrode sheet 1 and adjusts the thickness of the electrode active material layer 3 to within a predetermined range.

[0018] Fig. 2 is a schematic side view of the roll press machine 60. As shown in Fig. 2, the roll press machine 60 according to this embodiment includes an unwinding device 60A, a pressing 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 in a roll. The winding device 60C winds up the electrode sheet 1 that has been unwound from the unwinding device 60A and pressed by the pressing device 60B. The roll press machine 60 includes a control device 100 that controls the operations of the unwinding device 60A, the pressing device 60B, and the winding device 60C.

[0019] Fig. 3 is a schematic front view of the press device 60B. As shown in Fig. 3, the press device 60B includes a pair of press rolls 61U, 61D for pressing the electrode active material layer 3 formed on the electrode sheet 1, a press pressure adjustment mechanism 70 for adjusting the press pressure of the pair of press rolls 61U, 61D, a refrigerant supply device 80 for supplying a refrigerant to the press rolls 61U, 61D, and a plurality of temperature sensors 91-96 for detecting the surface temperatures of the press rolls 61U, 61D.

[0020] The pair of press rolls 61U, 61D face each other in the thickness direction (here, the up-down direction) of the electrode sheet 1. The upper press roll 61U has a roll body 62U that contacts and presses the electrode sheet 1. Both shaft portions 63UL and 63UR are connected to both sides of the roll body 62U. Both shaft portions 63UL and 63UR are disposed outward in the width direction from the electrode sheet 1 and have a smaller diameter than the roll body 62U. Both shaft portions 63UL and 63UR do not contact the electrode sheet 1. The lower press roll 61D also has a similar roll body 62D and both shaft portions 63DL, 63DR.

[0021] The material of the press rolls 61U, 61D is not limited, but may be a high-hardness material such as high carbon bearing steel (SUJ material) or alloy tool steel (SKD material). The size of the press rolls 61U, 61D is also not limited, but may be large, for example, with a diameter of about 800 mm and a length of about 1000 mm. For example, the gap between the press rolls 61U, 61D made of SUJ2 and with a diameter of 800 mm is calculated to decrease by about 0.01 mm when the temperature rises by 1°C.

[0022] The press pressure adjustment mechanism 70 includes a pair of upper bearings 71U supporting the upper press roll 61U, a pair of upper axle boxes 72U in which the pair of upper bearings 71U are respectively housed, a pair of lower bearings 71D supporting the lower press roll 61D, a pair of lower axle boxes 72D in which the pair of lower bearings 71D are respectively housed, an upper drive unit 73U that rotates the upper press roll 61U, a lower drive unit 73D that rotates the lower press roll 61D, a pair of gap adjustment screws 74, a pair of press cylinders 75, and a pair of bend cylinders 76.

[0023] The pair of upper bearings 71U rotatably support both shaft portions 63UL, 63UR of the upper press roll 61U. When the upper press roll 61U is rotated while applying a press pressure, heat is generated due to friction between the shaft portions 63UL, 63UR of the upper press roll 61U and the pair of upper bearings 71U. The effect of this heat will be described later. One of the upper axle boxes 72U also houses a transmission member (not shown) connected to the upper drive device 73U and a counterpart transmission member (not shown) connected to one shaft portion (e.g., 63UR) of the upper press roll 61U and meshed with the transmission member. The upper drive device 73U is, for example, an electric motor. Both transmission members are, for example, gears.

[0024] The pair of lower bearings 71D rotatably support both shaft portions 63DL, 63DR of the lower press roll 61D, respectively. One of the lower axle boxes 72D accommodates a transmission member (not shown) connected to the lower drive device 73D and a mating transmission member (not shown) connected to one shaft portion (e.g., 63DR) of the lower press roll 61D.

[0025] The pair of gap adjustment screws 74 adjust the vertical position of the upper press roll 61U. The gap between the upper press roll 61U and the lower press roll 61D can be adjusted by rotating the gap adjustment screws 74. However, the gap adjustment screws 74 may not be provided, and in that case, the gap between the upper press roll 61U and the lower press roll 61D may be adjusted by the operation of the press cylinder 75.

[0026] The pair of press cylinders 75 press the lower press roll 61D toward the upper press roll 61U. The pair of press cylinders 75 support the pair of lower bearings 71D and move them in the up-down direction. The electrode sheet 1 sandwiched between the pair of press rolls 61U, 61D is pressed by driving the pair of press cylinders 75. The pair of press cylinders 75 is one of the devices that adjust the press pressure that presses the electrode sheet 1. In this embodiment, the "press pressure" means a composite pressure of a bend pressure described later and a pressure generated by the press cylinder 75. Hereinafter, the pressure generated by the press cylinder 75 is also called "cylinder press pressure" to distinguish it from the "press pressure". In addition, the press cylinder 75 is an example of a lifting device that lifts and lowers one of the pair of press rolls 61U, 61D relative to the other. By driving the press cylinder 75, the gap between the pair of press rolls 61U, 61D can also be adjusted together with the cylinder press pressure. The lifting device may be configured to press the upper press roll 61U toward the lower press roll 61D. Alternatively, the lifting device may be configured to lower the upper press roll 61U and lift the lower press roll 61D.

[0027] The pair of bend cylinders 76 is also one of the devices that adjust the press pressure of the press device 60B. The pair of bend cylinders 76 are arranged between the shaft portion 63UL of the upper press roll 61U and the shaft portion 63DL of the lower press roll 61D, and between the shaft portion 63UR of the upper press roll 61U and the shaft portion 63DR of the lower press roll 61D. The pair of bend cylinders 76 press the press rolls 61U, 61D in the direction opposite to the press pressure by the press cylinder 75. This causes the press rolls 61U, 61D to bend or correct the bend. As a result, the gap between the press rolls 61U, 61D and the press pressure are adjusted. The bend pressure is independently controlled by the left and right bend cylinders 76, so that the gap between the press rolls 61U, 61D and the press pressure are adjusted on the left and right, respectively. The pair of bend cylinders 76 is an example of a bend device that bends the press rolls 61U, 61D. Here, "curving the press rolls 61U, 61D" may also include a case where the press rolls 61U, 61D are curved so as to straighten the press rolls 61U, 61D curved by driving the press cylinder 75. The pair of bending cylinders 76 are configured to be capable of adjusting the bending pressures for curving the press rolls 61U, 61D, respectively.

[0028] The refrigerant supply device 80 supplies the refrigerant to the pair of upper axle boxes 72U and the pair of lower axle boxes 72D. The refrigerant circulates in four circulation paths 81 including one upper axle box 72U, the other upper axle box 72U, one lower axle box 72D, and the other lower axle box 72D. Each circulation path 81 is provided with a pump 82 and a cooling device 83. The refrigerant circulates in the circulation path 81 by driving the pump 82, and removes heat from the bearing 71U or 71D when passing through the bearing 71U or 71D. The refrigerant whose temperature has increased as a result 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 amount (amount per time) of the refrigerant supplied to the axle boxes 72U and 72D by controlling the pump 82 to adjust the circulation speed of the refrigerant.

[0029] 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 press roll 61U. Here, the first temperature sensor 91 to the third temperature sensor 93 are disposed above the upper press roll 61U. The first temperature sensor 91 to the third temperature sensor 93 are spaced apart from the upper press roll 61U. The first temperature sensor 91 to the third temperature sensor 93 are non-contact temperature sensors, for example, infrared temperature sensors. However, the first temperature sensor 91 to the third temperature sensor 93 may be contact temperature sensors. Furthermore, the first temperature sensor 91 to the third temperature sensor 93 may be disposed in front of, behind, or at other positions of the upper press roll 61U.

[0030] The first temperature sensor 91 is provided 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 of the upper press roll 61U. The second temperature sensor 92 is provided to the right of the first temperature sensor 91, and detects the surface temperature of the center of the upper press roll 61U. The third temperature sensor 93 is provided 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 of the upper press roll 61U. Here, the "end" of the upper press roll 61U means the substantial end of the press roll 61U, that is, the end of the roll body 62U here. The "end" of the upper press roll 61U refers to, for example, both end regions when the roll body 62U is divided into three equal parts in the axial direction. The "center" of the upper press roll 61U refers to, for example, the middle region when the roll body 62U is divided into three equal parts in the axial direction. "Detecting the temperature of the end or the center" means measuring the temperature of at least one point of the end or the center.

[0031] 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 press roll 61D. Here, the fourth temperature sensor 94 to the sixth temperature sensor 96 are disposed below the lower press roll 61D. However, the fourth temperature sensor 94 to the sixth temperature sensor 96 may be disposed in front of, behind, or at other positions of the lower press roll 61D. The fourth temperature sensor 94 to the sixth temperature sensor 96 are also non-contact temperature sensors.

[0032] The fourth temperature sensor 94 is provided at the leftmost position among the fourth to sixth temperature sensors 94 to 96, and detects the surface temperature of the left end portion of the lower press roll 61D (roll body portion 62D). The fifth temperature sensor 95 is provided to the right of the fourth temperature sensor 94, and detects the surface temperature of the center portion of the lower press roll 61D (roll body portion 62D). The sixth temperature sensor 96 is provided at the rightmost position among the fourth to sixth temperature sensors 94 to 96, and detects the surface temperature of the right end portion of the lower press roll 61D (roll body portion 62D).

[0033] The control device 100 is configured to adjust the press pressure based on the surface temperature of the press rolls 61U, 61D detected by the temperature sensors 91-96. Here, the control device 100 adjusts the bend pressure with which the bend cylinder 76 bends the press rolls 61U, 61D based on the temperature detected by the temperature sensors 91-96. In detail, the control device 100 pre-records correlation data between the temperature detected by the temperature sensors 91-96 and the thickness of the electrode sheet 1. The control device 100 adjusts the bend pressure with which the bend cylinder 76 bends the press rolls 61U, 61D based on the correlation data. The control device 100 also pre-records correlation data between the amount of change in the bend pressure and the amount of change in the thickness of the electrode sheet 1. The control device 100 adjusts the bend pressure to reduce the difference in thickness depending on the position in the width direction of the electrode sheet 1, and to make the thickness uniform.

[0034] 2, the control device 100 includes a first recording unit 101 in which correlation data between the temperatures detected by the temperature sensors 91-96 and the thickness of the electrode sheet 1 is recorded, and a second recording unit 102 in which correlation data between the amount of change in bending pressure and the amount of change in thickness of the electrode sheet 1 is recorded. The control device 100 also includes a bending pressure control unit 103 that adjusts the bending pressure with which the bending cylinder 76 bends the press rolls 61U, 61D, based on the correlation data recorded in the first recording unit 101 and the correlation data recorded in the second recording unit 102.

[0035] The thickness of the electrode sheet 1 in the above correlation data is actually measured after the pressing process is completed. The thickness of the electrode sheet 1 may increase compared to immediately after pressing due to, for example, springback of the electrode sheet 1. Therefore, the gap between the upper press roll 61U and the lower press roll 61D may not be the same as the thickness of the electrode sheet 1 after the pressing process. Therefore, the above correlation data is created based on the thickness of the electrode sheet 1 actually measured after the pressing process is completed.

[0036] The control device 100 also controls the press cylinder 75 based on the temperature detected by the temperature sensors 91-96 to adjust the press pressure. In detail, the control device 100 performs the above control based on the correlation data between the temperature detected by the temperature sensors 91-96 and the thickness of the electrode sheet 1 described above. The control device 100 thereby controls the thickness of each part in the width direction of the electrode sheet 1 to be within a predetermined range. The control device 100 also has correlation data between the amount of change in the cylinder press pressure and the amount of change in the electrode sheet 1 recorded in advance. As shown in FIG. 2, the control device 100 includes a third recording unit 104 in which correlation data between the amount of change in the cylinder press pressure and the amount of change in the thickness of the electrode sheet 1 is recorded, and a press pressure control unit 105 that controls the press cylinder 75 based on the temperature detected by the temperature sensors 91-96 to adjust the cylinder press pressure.

[0037] Furthermore, the control device 100 adjusts the amount of refrigerant supplied from the refrigerant supply device 80 based on the temperatures detected by the temperature sensors 91-96. More specifically, the control device 100 controls the multiple pumps 82 to adjust the supply speed of the refrigerant. As shown in FIG. 2, the control device 100 includes a cooling control unit 106 that controls the pumps 82 based on the temperatures detected by the temperature sensors 91-96 to adjust the amount of refrigerant supplied from the refrigerant supply device 80. In this way, the control device 100 brings the temperatures of the press rolls 61U, 61D closer to a predetermined temperature and reduces the temperature difference depending on the location of the press rolls 61U, 61D. Here, the control device 100 controls each pump 82 independently.

[0038] [Controlling electrode sheet thickness] An example of thickness control of the electrode sheet 1 by the roll press machine 60 will be described below. The roll press machine 60 suppresses the temperature rise of the press rolls 61U, 61D by flowing a refrigerant in order to facilitate the thickness control of the electrode sheet 1. When the temperature of the press rolls 61U, 61D rises, the press rolls 61U, 61D thermally expand, and the gap between them narrows. This reduces the thickness of the electrode sheet 1. By suppressing the temperature rise of the press rolls 61U, 61D, it is possible to suppress the thickness of the electrode sheet 1 from becoming thinner. When the temperature of the press rolls 61U, 61D rises, the roll press machine 60 increases the supply amount of the refrigerant. When the temperature of the press rolls 61U, 61D rises despite cooling, the roll press machine 60 controls the thickness of the electrode sheet 1 by controlling the bend pressure and the cylinder press pressure.

[0039] FIG. 4 is a flowchart showing a process of controlling the thickness of the electrode sheet 1 by controlling the bend pressure and the cylinder press pressure. As shown in FIG. 4, in step S01 of controlling the thickness of the electrode sheet 1, the roll press machine 60 acquires the temperatures of the left ends of the press rolls 61U, 61D measured by the first temperature sensor 91 and the fourth temperature sensor 94, respectively. In step S02, the thickness of the left end of the electrode sheet 1 is estimated based on the acquired temperatures of the left ends of the press rolls 61U, 61D and the correlation data recorded in the first recording unit 101. FIG. 5 is an example of correlation data between the temperature and the thickness of the electrode sheet 1, more specifically, correlation data between the amount of change in the temperature of the press rolls 61U, 61D and the amount of change in the thickness of the electrode sheet 1. As shown in FIG. 5, as the temperature of the press rolls 61U, 61D increases, the estimated thickness of the electrode sheet 1 becomes thinner. Here, as the temperature of the left end of the press rolls 61U, 61D increases, the estimated thickness of the left end of the electrode sheet 1 becomes thinner.

[0040] In step S03, the roll press machine 60 acquires the temperatures of the right ends of the press rolls 61U, 61D measured by the third temperature sensor 93 and the sixth temperature sensor 96, respectively, in the same manner as for the left end. In the following step S04, the thickness of the right end of the electrode sheet 1 is estimated from the acquired temperatures of the right ends of the press rolls 61U, 61D based on the correlation data recorded in the first recording unit 101. As the temperatures of the right ends of the press rolls 61U, 61D increase, the estimated thickness of the right end of the electrode sheet 1 becomes thinner.

[0041] In step S05, the roll press machine 60 acquires the temperatures of the central parts of the press rolls 61U, 61D measured by the second temperature sensor 92 and the fifth temperature sensor 95, respectively. In step S06, the thickness of the central part of the electrode sheet 1 is estimated from the acquired temperatures of the central parts of the press rolls 61U, 61D based on the correlation data recorded in the first recording unit 101. Heat is generated mainly by friction between the press rolls 61U, 61D and the bearings 71U, 71D. Therefore, the temperature of the central parts of the press rolls 61U, 61D is usually lower than the temperatures of both ends. The estimated thickness of the central part of the electrode sheet 1 is usually thicker than the estimated thickness of both ends. The order of the set of steps S01 and S02, the set of steps S03 and S04, and the set of steps S05 and S06 may be interchanged.

[0042] In step S07, the roll press machine 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, based on the correlation data recorded in the second recording unit 102, the bend pressure of the left bend cylinder 76 is adjusted so as to eliminate the difference obtained in step S07. 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 bend 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, based on the correlation data recorded in the second recording unit 102, the bend pressure of the right bend cylinder 76 is adjusted so as to eliminate the difference obtained in step S09.

[0043] Furthermore, in step S11, the difference between the thickness of the central portion of the electrode sheet 1 estimated in step S06 and a predetermined target value of the thickness of the central portion is obtained. In step S12, the cylinder press pressure of the press cylinder 75 is adjusted so as to eliminate the difference from the target value based on the correlation data recorded in the third recording unit 104. The thinner the estimated thickness of the central portion of the electrode sheet 1 is, the smaller the cylinder press pressure is set. Although not shown in the figure, steps S01 to S12 are repeated, for example, at predetermined time intervals. Note that the order of the set of steps S07 and S08, the set of steps S09 and S10, and the set of steps S11 and S12 may be interchanged.

[0044] [Effects of the embodiment] The following describes the effects that can be achieved by the manufacturing apparatus 10 for the electrode sheet 1 according to this embodiment.

[0045] The manufacturing apparatus 10 for the electrode sheet 1 according to this embodiment includes a pair of press rolls 61U, 61D for pressing the electrode active material layer 3 formed on the electrode sheet 1, a press pressure adjustment mechanism 70 for adjusting the press pressure of the pair of press rolls 61U, 61D, temperature sensors 91-96 for detecting the surface temperature of the pair of press rolls 61U, 61D, and a control device 100. The control device 100 is configured to adjust the press pressure based on the surface temperature of the press rolls 61U, 61D detected by the temperature sensors 91-96. The temperature sensor may detect the surface temperature of at least one of the pair of press rolls 61U, 61D.

[0046] According to the manufacturing apparatus 10 for the electrode sheet 1, the thickness of the electrode sheet 1 can be controlled by detecting the surface temperatures of the press rolls 61U, 61D and adjusting the pressing pressure of the press rolls 61U, 61D based on the detected temperature.

[0047] In the conventional roll press machine, the thickness of the electrode sheet after pressing is measured to address the problem of the thickness of the electrode sheet changing due to heat generated at the bearing part of the press roll. In detail, in the conventional roll press machine, the thickness of the electrode sheet is controlled to a target thickness by feedback control of the pressing pressure based on the measurement of the thickness of the electrode sheet after pressing. However, the inventors of the present application have found that, at least when pressing an electrode sheet on which an electrode active material layer is formed, the thickness of the electrode sheet may change from immediately after pressing due to, for example, springback of the electrode sheet. Therefore, if the pressing pressure is adjusted based on the measurement of the thickness of the electrode sheet, there may be cases where the thickness of the electrode sheet cannot be well controlled.

[0048] In the manufacturing apparatus 10 for the electrode sheet 1 according to this embodiment, the thickness of the electrode sheet 1 after pressing is estimated based on the surface temperatures of the press rolls 61U, 61D, and the pressing pressure of the press rolls 61U, 61D is adjusted. Therefore, even if the thickness of the electrode sheet 1 changes immediately after pressing, the thickness of the electrode sheet 1 can be controlled.

[0049] In this embodiment, the press pressure adjustment mechanism 70 includes a bend cylinder 76 that bends the press rolls 61U, 61D. The control device 100 adjusts the bend pressure with which the bend cylinder 76 bends the press rolls 61U, 61D, based on the temperatures detected by the temperature sensors 91-96. With this configuration, it is possible to suppress partial changes in thickness of the electrode sheet 1 (here, the thickness becoming thinner at both end portions of the electrode sheet 1) caused by bending the press rolls 61U, 61D.

[0050] The manufacturing apparatus 10 for the electrode sheet 1 according to this embodiment further includes a refrigerant supplying device 80 that supplies a refrigerant to the press rolls 61U, 61D. The control device 100 adjusts the amount of refrigerant supplied from the refrigerant supplying device 80 based on the temperatures detected by the temperature sensors 91-96. This configuration makes it possible to suppress an increase in the temperature of the press rolls 61U, 61D. This makes it possible to suppress the thickness of the electrode sheet 1 from becoming thin.

[0051] In this embodiment, the press pressure adjustment mechanism 70 includes a press cylinder 75 that raises and lowers one of the pair of press rolls 61U, 61D relative to the other (here, raises and lowers the lower press roll 61D). The control device 100 controls the press cylinder 75 based on the temperatures detected by the temperature sensors 91-96 to adjust the press pressure. With this configuration, the thickness of the electrode sheet 1 can be controlled simultaneously across the entire width.

[0052] In this embodiment, correlation data between the temperatures detected by the temperature sensors 91-96 and the thickness of the electrode sheet 1 is pre-recorded in the control device 100. The control device 100 controls the press pressure adjustment mechanism 70 based on the correlation data. With this configuration, the press pressure adjustment mechanism 70 is controlled based on the correlation data between the temperatures detected by the temperature sensors 91-96 and the thickness of the electrode sheet 1. Therefore, even if the thickness of the electrode sheet 1 changes immediately after pressing, the thickness of the electrode sheet 1 can be controlled.

[0053] More specifically, the manufacturing device 10 of the electrode sheet 1 according to the present embodiment includes a first temperature sensor 91 to a sixth temperature sensor 96. The first temperature sensor 91 and the fourth temperature sensor 94 detect the temperature of the left end of the press rolls 61U, 61D, and the second temperature sensor 92 and the fifth temperature sensor 95 detect the temperature of the center of the press rolls 61U, 61D. The third temperature sensor 93 and the sixth temperature sensor 96 detect the temperature of the right end of the press rolls 61U, 61D. According to this configuration, the temperatures of the end and center of the press rolls 61U, 61D are measured, so that the thickness of the end and center of the electrode sheet 1 in the width direction can be controlled. More specifically, the control device 100 adjusts the bending pressure with which the bending cylinder 76 bends the press rolls 61U, 61D based on the recorded correlation data. As a result, the difference in thickness between the end and center of the electrode sheet 1 in the width direction caused by the temperature difference between the end and center of the press rolls 61U, 61D 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 press rolls 61U and 61D is also suppressed.

[0054] In this embodiment, the temperature sensors 91-96 are non-contact temperature sensors. With this configuration, there is no risk of the surfaces of the press rolls 61U, 61D being damaged by contact with the temperature sensors. This prevents generated foreign matter from being mixed into the electrode sheet 1 and degrading the quality of the electrode sheet 1. Furthermore, since there is no risk of this, the press rolls 61U, 61D can be rotated at high speed. This allows the productivity of the electrode sheet 1 to be improved.

[0055] [Other embodiments] An embodiment of the electrode sheet manufacturing apparatus proposed herein has been described above. However, the above embodiment is merely an example, and the present invention can be implemented in other ways. For example, in the above embodiment, the press pressure is controlled by controlling the press cylinder 75 and the bend cylinder 76, but this is not limited thereto. The press pressure may be controlled, for example, by controlling one or more press cylinders.

[0056] In the above embodiment, the coolant supply device 80 is provided, but it may not be provided if possible.

[0057] In addition, the above-described embodiments do not limit the present invention unless otherwise specified. Furthermore, the technology disclosed herein can be modified in various ways, and the components and processes described herein can be omitted or combined as appropriate, provided that no particular problems arise.

[0058] This specification includes the disclosures set forth in the following sections:

[0059] Section 1: A pair of rolls for pressing the electrode active material layer formed on the electrode sheet; a press pressure adjustment mechanism for adjusting the press pressure of the pair of rolls; a temperature sensor for detecting a surface temperature of at least one of the pair of rolls; A control device, The control device is configured to adjust the press pressure based on the surface temperature of the roll detected by the temperature sensor. Electrode sheet manufacturing equipment.

[0060] Section 2: The press pressure adjustment mechanism includes a bending device that curves the roll, The control device adjusts a bending pressure at which the bending device bends the roll, based on the temperature detected by the temperature sensor. Item 1. An electrode sheet manufacturing apparatus according to item 1.

[0061] Section 3: A coolant supply device is further provided for supplying a coolant to the roll, The control device adjusts the amount of refrigerant supplied from the refrigerant supply device based on the temperature detected by the temperature sensor. Item 3. The electrode sheet manufacturing apparatus according to item 1 or 2.

[0062] Section 4: The press pressure adjustment mechanism includes a lifting device that lifts and lowers one of the pair of rolls relative to the other, The control device controls the lifting device based on the temperature detected by the temperature sensor to adjust the press pressure. Item 4. An electrode sheet manufacturing apparatus according to any one of Items 1 to 3.

[0063] Section 5: The control device stores in advance correlation data between the temperature detected by the temperature sensor and the thickness of the electrode sheet, The control device controls the press pressure adjusting mechanism based on the correlation data. Item 5. An electrode sheet manufacturing apparatus according to any one of items 1 to 4.

[0064] Item 6: The temperature sensor is a non-contact temperature sensor. 6. An electrode sheet manufacturing apparatus according to any one of items 1 to 5.

[0065] Section 7: Further comprising another temperature sensor; one of the temperature sensor and the other temperature sensor detects a temperature of the end of the roll; the other of the temperature sensor and the other temperature sensor detects a temperature of a central portion of the roll. Item 7. An electrode sheet manufacturing apparatus according to any one of items 1 to 6.

[0066] Section 8: The press pressure adjustment mechanism includes a bending device that curves the roll, The control device stores in advance correlation data between the temperature detected by the temperature sensor or the other temperature sensor and the thickness of the electrode sheet, The control device adjusts a bending pressure at which the bending device bends the roll based on the correlation data. Item 8. The electrode sheet manufacturing apparatus according to item 7. [Explanation of symbols]

[0067] 1 Electrode sheet 2 Electrode foil 3 Electrode active material layer 10 Electrode sheet manufacturing equipment 20 Weighing device 30 Kneading equipment 40 Coating equipment 50 Drying equipment 60 Roll Press Machine 60A Unwinding Device 60B Press device 60C winding device 61D Lower press roll (roll) 61U Upper press roll (roll) 62D Roll body (lower side) 62U Roll body (upper side) 63DL Shaft 63DR shaft part 63UL Shaft 63UR shaft 70 Press pressure adjustment mechanism 71D Lower Bearing 71U Upper bearing 72D Lower axle box 72U upper axle box 73D Lower Drive Unit 73U Upper Drive Unit 74 Gap adjustment screw 75 Press cylinder (lifting device) 76 Bend cylinder (bending device) 80 Refrigerant supply device 81 Circulation flow path 82 Pump 83 Cooling device 91 First temperature sensor (temperature sensor) 92 Second temperature sensor (another temperature sensor) 93 3rd temperature sensor (temperature sensor) 94 4th temperature sensor (temperature sensor) 95 5th temperature sensor (other temperature sensor) 96 6th temperature sensor (temperature sensor) 100 Control device 101 First Recording Section 102 Second Recording Section 103 Bend pressure control section 104 Third Recording Section 105 Press pressure control section 106 Cooling control unit

Claims

1. A pair of rolls for pressing the electrode active material layer formed on the electrode sheet; a press pressure adjustment mechanism for adjusting the press pressure of the pair of rolls; a temperature sensor for detecting a surface temperature of at least one of the pair of rolls; A control device, The control device is configured to adjust the press pressure based on the surface temperature of the roll detected by the temperature sensor. Electrode sheet manufacturing equipment.

2. The press pressure adjustment mechanism includes a bending device that curves the roll, The control device adjusts a bending pressure at which the bending device bends the roll, based on the temperature detected by the temperature sensor. The electrode sheet manufacturing apparatus according to claim 1 .

3. A coolant supply device is further provided for supplying a coolant to the roll, The control device adjusts the amount of refrigerant supplied from the refrigerant supply device based on the temperature detected by the temperature sensor. The electrode sheet manufacturing apparatus according to claim 1 .

4. The press pressure adjustment mechanism includes a lifting device that lifts and lowers one of the pair of rolls relative to the other, The control device controls the lifting device based on the temperature detected by the temperature sensor to adjust the press pressure. The electrode sheet manufacturing apparatus according to claim 1 .

5. The control device stores in advance correlation data between the temperature detected by the temperature sensor and the thickness of the electrode sheet, The control device controls the press pressure adjusting mechanism based on the correlation data. The electrode sheet manufacturing apparatus according to claim 1 .

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

7. Further comprising another temperature sensor; one of the temperature sensor and the other temperature sensor detects a temperature of the end of the roll; the other of the temperature sensor and the other temperature sensor detects a temperature of a central portion of the roll. The electrode sheet manufacturing apparatus according to claim 1 .

8. The press pressure adjustment mechanism includes a bending device that curves the roll, The control device stores in advance correlation data between the temperature detected by the temperature sensor or the other temperature sensor and the thickness of the electrode sheet, The control device adjusts a bending pressure at which the bending device bends the roll based on the correlation data. The electrode sheet manufacturing apparatus according to claim 7 .

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