JP5831223B2 - Electrode drying method, electrode drying control method, electrode drying apparatus, and electrode drying control apparatus - Google Patents

Description

  The present invention relates to an electrode drying method for drying an electrode, an electrode drying control method for drying an electrode at a predetermined position in a drying device, an electrode drying device, and an electrode drying control device.

  Conventionally, for example, an electrode used in a lithium ion secondary battery is formed by applying an electrode slurry containing a volatile solvent to a current collector and then drying the electrode slurry. Before starting mass production of such an electrode, whether or not the drying conditions set in advance are appropriate is verified in trial production and mass production trial production.

  For example, in Patent Document 1, after a thermocouple is embedded in an electrode paste applied to an electrode substrate, the temperature of the electrode paste whose temperature rapidly rises immediately before the completion of drying is measured with a thermocouple. A method for verifying the dry state of the electrode paste is proposed.

Japanese Patent Laid-Open No. 2003-178752

  However, in mass production carried out after trial production related to electrode drying or mass production trial production, if the electrode is dried continuously over several kilometers in a drying furnace, for example, the enormous heat of evaporation of the solvent contained in the electrode paste is generated. As a result, the temperature inside the drying furnace decreases.

  Such temperature fluctuations in the drying furnace are difficult to verify at the stage of trial manufacture or mass production trial related to electrode drying disclosed in Patent Document 1. In the first place, an error occurs in the fluctuation of the temperature in the drying furnace between the production lots in the mass production of the electrodes. Therefore, the electrode drying conditions that are appropriate in the trial production and the mass production trial performed in advance are not necessarily appropriate in the mass production of the electrodes.

  If the electrode drying conditions are not appropriate for actual mass production of the electrode, the electrode slurry applied to the current collector constituting the electrode may be sufficiently dried before the electrode drying operation is completed. is there. Thus, when drying becomes inadequate, the active material contained in the electrode slurry will not adhere | attach firmly on an electrical power collector, but the problem that the lifetime of the electrode after manufacture does not satisfy a design value will generate | occur | produce.

  The present invention has been made to solve the above-described problems, and an electrode drying method and an electrode drying method that can sufficiently dry the electrode to ensure quality even when the electrode is continuously dried It is an object to provide a control method, an electrode drying apparatus, and an electrode drying control apparatus.

  The electrode drying method according to the present invention that achieves the above object is a method in which an electrode formed by applying an electrode slurry containing a volatile solvent to a current collector is dried with a drying device. Such an electrode drying method has a conveyance process, a drying process, a measurement process, and a drying determination process. In the transport process, the electrodes are transported. In the drying step, the electrode is dried by a drying means. In the measuring step, the position of the end of the electrode is measured by a measuring means provided along the electrode transport path. In the dry determination step, the dry state of the electrode is determined based on the amount of displacement of the position of the end of the electrode.

  The electrode drying control method according to the present invention that achieves the above object is a control method for drying an electrode formed by applying an electrode slurry containing a volatile solvent on a current collector at a predetermined position of a drying apparatus. Such an electrode drying control method has a conveyance process, a drying process, a measurement process, and a drying control process. In the transport process, the electrodes are transported. In the drying step, the electrode is dried by a drying means. In the measuring step, the position of the end of the electrode is measured by a measuring means provided along the electrode transport path. In the drying control step, the drying state of the electrode is determined based on the displacement amount of the position of the end portion of the electrode, and the drying means is controlled so that the drying of the electrode is completed at a position within a predetermined range in the transport path.

  The electrode drying apparatus according to the present invention that achieves the above object is an apparatus for drying an electrode formed by applying an electrode slurry containing a volatile solvent to a current collector. Such an electrode drying apparatus has a conveyance part, a drying part, a measurement part, and a dry determination part. In the transport unit, the electrode is transported. In the drying section, the electrode is dried by a drying means. In the measurement unit, the position of the end of the electrode is measured by measurement means provided along the electrode transport path. The dry determination unit determines the dry state of the electrode based on the displacement amount of the position of the end of the electrode.

  The electrode drying control device according to the present invention that achieves the above object is a control device that dries an electrode formed by applying an electrode slurry containing a volatile solvent on a current collector at a predetermined position. Such an electrode drying control method includes a transport unit, a drying unit, a measurement unit, and a drying control unit. In the transport unit, the electrode is transported. In the drying section, the electrode is dried by a drying means. In the measurement unit, the position of the end of the electrode is measured by measurement means provided along the electrode transport path. The drying control unit determines the drying state of the electrode based on the amount of displacement of the position of the end portion of the electrode, and controls the drying means so that the drying of the electrode is completed at a position within a predetermined range in the transport path.

  According to the present invention configured as described above, in order to determine the dry state of the electrode based on the amount of displacement of the end position of the electrode measured by the measuring means, The quality of the electrode can be ensured.

It is a perspective view which shows the electrode drying apparatus which concerns on 1st Embodiment. It is a side view which shows the electrode drying apparatus which concerns on 1st Embodiment. It is a schematic perspective view which shows the electrode of the single side coating in the drying process in the electrode drying apparatus which concerns on 1st Embodiment. It is principal part sectional drawing which shows the electrode of the single-sided coating in the drying process shown in FIG. 3, (A) is an electrode of the state before drying in the position of the AA 'line of FIG. 3, (B) is a figure. 3, the electrode in the middle of drying at the position of line BB ′, (C) shows the electrode in the state after drying at the position of line CC ′ in FIG. It is a graph which shows the displacement rate of the edge part of the electrode of the single side coating in the drying process illustrated in FIG. It is a graph which shows the dry state of the electrode slurry of the single side coating in the drying process illustrated in FIG. It is a schematic perspective view which shows the electrode of the double-sided coating in the drying process in the electrode drying apparatus which concerns on 1st Embodiment. It is principal part sectional drawing which shows the electrode of the double-sided coating in the drying process shown in FIG. 7, (A) is an electrode of the state before drying in the position of the AA 'line of FIG. 7, (B) is a figure. 7 shows an electrode in the middle of drying at the position of line BB ′, and FIG. 7C shows the electrode after drying at the position of line CC ′ in FIG. It is a graph which shows the displacement ratio of the edge part of the electrode of the double-sided coating in the drying process illustrated in FIG. It is a perspective view which shows one method of measuring the position of the edge part of an electrode in the electrode drying apparatus which concerns on 1st Embodiment. It is principal part sectional drawing which shows the measuring method of the position of the edge part of the electrode shown in FIG. It is a perspective view which shows the other method of measuring the position of the edge part of an electrode in the electrode drying apparatus which concerns on 1st Embodiment. It is principal part sectional drawing which shows the measuring method of the position of the edge part of the electrode shown in FIG. It is a perspective view which shows the other method of measuring the position of the edge part of an electrode in the electrode drying apparatus which concerns on 1st Embodiment. It is principal part sectional drawing which shows the measuring method of the position of the edge part of the electrode shown in FIG. It is a side view which shows typically the electrode drying control apparatus which concerns on 2nd Embodiment. It is a flowchart which shows the control which stores the drying position of an electrode in the position in the predetermined range in the conveyance path | route of the electrode using the electrode drying control apparatus which concerns on 2nd Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. In addition, the size and ratio of each member in the drawings are exaggerated for convenience of explanation and may be different from the actual size and ratio.

<First Embodiment>
The electrode drying apparatuses 1 to 3 according to the first embodiment are apparatuses for drying an electrode 100 formed by applying an electrode slurry 101 containing a volatile solvent to a current collector 102. Here, the electrode drying apparatus 1 is comprised from the conveyance part 10, the drying part 20, the measurement part 30, and the dry determination part 60, as shown in FIG. The electrode drying apparatus 2 according to the first embodiment is a modification of the electrode drying apparatus 1 and includes a measurement unit 40 instead of the measurement unit 30 as shown in FIG. Furthermore, the electrode drying apparatus 3 according to the first embodiment is also a modification of the electrode drying apparatus 1 and includes a measurement unit 50 instead of the measurement unit 30 as shown in FIG. Hereinafter, the structure of the electrode drying apparatuses 1 to 3 and the method for drying the electrode 100 using the electrode drying apparatuses 1 to 3 will be described.

  As shown in FIG. 1, the transport unit 10 of the electrode drying apparatuses 1 to 3 transports an electrode 100 formed by applying an electrode slurry 101 containing a volatile solvent to a current collector 102.

  As shown in FIG. 2, the transport unit 10 includes a supply roll 11, a first guide roll 12, a second guide roll 13, a plurality of support rolls 14, and a third guide roll along the transport path of the electrode 100. 15, a fourth guide roll 16 and a winding roll 17. The structure of this conveyance part 10 and the conveyance method of the electrode 100 by the conveyance part 10 are demonstrated, referring FIG. 1 and FIG. In addition, the structure of the electrode 100 conveyed by the conveyance part 10 is demonstrated in detail in the drying part 20 mentioned later.

  The supply roll 11 of the transport unit 10 has a cylindrical shape that is rotatably held, and holds the current collector 102 before being applied with the electrode slurry 101 in a roll shape. The supply roll 11 carries out the current collector 102 toward the first guide roll 12 while rotating in accordance with a winding roll 17 described later. Here, the coater 91 of the electrode slurry application unit 90 is disposed between the supply roll 11 and the first guide roll 12 and is in contact with the current collector 102. The coater 91 applies the electrode slurry 101 with a predetermined thickness to the current collector 102 to form the electrode 100. The first guide roll 12 and the second guide roll 13 have a cylindrical shape that is rotatably held, and guide the electrode 100 formed by the coater 91 toward the drying unit 20.

  The support roll 14 of the transport unit 10 has a cylindrical shape that is rotatably held, and a plurality of support rolls 14 are disposed in each of the first heating zone 20A to the eighth heating zone 20H of the drying unit 20. This support roll 14 contacts the back side of the current collector 102 to which the electrode slurry 101 is not applied. The third guide roll 15 and the fourth guide roll 16 each have a cylindrical shape that is rotatably held, and guides the electrode 100 after being transported from the drying unit 20 toward the take-up roll 17. The take-up roll 17 has a cylindrical shape that is rotatably held, and takes up and stores the electrode 100 carried out from the fourth guide roll 16. The winding roll 17 is rotationally driven at a constant speed in a predetermined direction by a motor (not shown).

  As described above, in the transport unit 10, the electrode 100 is formed by applying the electrode slurry 101 to the long current collector 102 supplied from the supply roll 11 using the coater 91. Thereafter, in the transport unit 10, the electrode 100 dried in the drying unit 20 is wound and stored by the winding roll 17.

  The drying unit 20 dries the electrode 100 by a drying unit. This drying means corresponds to, for example, the heater 22 described later, but is not particularly limited as long as the electrode 100 can be dried. For example, a fan may be used. Here, as shown in FIG. 1, the drying unit 20 includes, for example, eight heating zones of the first heating zone 20 </ b> A to the eighth heating zone 20 </ b> H from the upstream side to the downstream side of the transport unit 10, and each independently. Control. As shown in FIG. 2, the drying unit 20 includes an air supply fan 21, a heater 22, a circulation fan 23, an upper nozzle 24, and a lower part in each of the first heating zone 20 </ b> A to the eighth heating zone 20 </ b> H. The nozzle 25, the circulation port 26, the exhaust port 27, the exhaust fan 28, and the heat insulating wall 29 are configured. The configuration of the drying unit 20 and the drying of the electrode 100 in the drying unit 20 will be described with reference to FIGS.

  First, the configuration of the drying unit 20 will be described with reference to FIGS. 1 and 2.

  The air supply fan 21 of the drying unit 20 is a blower for taking air into the heating zones from the outside. The heater 22 of the drying unit 20 is a heater that is provided in each heating zone and heats the air taken in via the air supply fan 21 to a predetermined temperature. The circulation fan 23 of the drying unit 20 is a blower that is provided in each heating zone and circulates the air heated by the heater 22 to the upper nozzle 24 and the lower nozzle 25. The upper nozzle 24 of the drying unit 20 is provided above each heating zone and supplies hot air from above to the electrode 100 being conveyed. Similarly, the lower nozzle 25 of the drying unit 20 is provided in the lower part of each heating zone, and supplies hot air to the conveyed electrode 100 from below.

  In addition, the circulation port 26 of the drying unit 20 is an opening for reusing the hot air supplied from the upper nozzle 24 and the lower nozzle 25 to each heating zone, provided in the lower part of each heating zone. The circulation port 26 is connected to the heater 22 through a pipe. In addition, the exhaust port 27 of the drying unit 20 is provided at the upper part of each heating zone, and is an opening for exhausting the air in each heating zone to the outside. Further, the exhaust fan 28 of the drying unit 20 is a blower for releasing the air exhausted from the exhaust port 27 provided in the upper part of each heating zone to the outside. The exhaust fan 28 is connected to the exhaust port 27 of each heating zone via a pipe. Further, the heat insulating walls 29 of the drying unit 20 are provided at the upper part, the side part, and the lower part of each heating zone, and each of the eight heating zones of the first heating zone 20A to the eighth heating zone 20H is independently set at a predetermined temperature. It is a wall for heat insulation to control.

  Such a drying unit 20 heats and drys the electrode 100 with different temperature control in eight heating zones of the first heating zone 20A to the eighth heating zone 20H. Specifically, for example, first, in the first heating zone 20A and the second heating zone 20B, the temperature is adjusted so that the temperature of the electrode 100 gradually increases. Next, in the third heating zone 20C to the fifth heating zone 20E, the temperature is adjusted so that the temperature of the electrode 100 becomes a constant value. In the third heating zone 20C to the fifth heating zone 20E, the drying rate of the electrode slurry 101 constituting the electrode 100 is constant. Further, in the sixth heating zone 20F to the eighth heating zone 20H, the temperature is adjusted so that the temperature of the electrode 100 gradually increases again. In the sixth heating zone 20F to the eighth heating zone 20H, the drying rate of the electrode slurry 101 constituting the electrode 100 is gradually reduced.

  Here, the configuration of the electrode 100 will be described in detail with reference to FIG.

  As shown in FIG. 3, the electrode 100 is formed by applying an electrode slurry 101 to a current collector 102 that is a conductor and then drying the electrode slurry 101. The current collector 102 of the electrode 100 is made of an electrode foil, and for example, aluminum, copper, nickel, iron, or stainless steel can be used. Here, for the positive electrode current collector 102, for example, an electrode foil made of aluminum is used. Similarly, for the negative electrode current collector 102, for example, an electrode foil made of copper is used. The thickness of the electrode foil is about 20 μm when the material is aluminum, and about 10 μm when the material is copper.

  Moreover, the electrode slurry 101 of the electrode 100 has an active material, a conductive support agent, and a binder, for example, and is made into predetermined viscosity by adding a volatile solvent. Here, in the electrode 100 shown in a schematic perspective view in FIG. 3, the electrode 100 at the position of the A-A ′ line is in a state before the electrode slurry 101 a is dried. Further, the electrode 100 at the position of the C-C ′ line shown in FIG. 3 is in a state where the drying of the electrode slurry 101 c has been completed. For example, such an electrode slurry 101 is applied to a current collector 102 having a thickness of 20 μm with a thickness of 200 μm, and contracts to a thickness of 100 μm when drying is completed.

  The active material for the positive electrode of the electrode slurry 101 of the electrode 100 is, for example, lithium manganate. Here, it is preferable to apply a lithium-transition metal composite oxide as the positive electrode active material from the viewpoint of capacity and output characteristics. Moreover, the active material for negative electrodes is a graphite, for example. Here, hard carbon or a lithium-transition metal composite oxide may be used as the active material for the negative electrode. The conductive auxiliary agent is, for example, acetylene black, carbon black, or graphite. The binder is, for example, polyvinylidene fluoride (PVDF). The solvent is, for example, normal methyl pyrrolidone (NMP) or water. Here, the solvent contained in the electrode slurry 101 is removed from the electrode slurry 101 by evaporating at the time of drying.

  Next, regarding the drying of the electrode 100 by the drying unit 20, a case where the electrode slurry 101 is applied to one side of the current collector 102 (single-side coating) will be described with reference to FIGS.

In the electrode 100 shown in the schematic perspective view of FIG. 3, the electrode 100 at the position of the line AA ′ is in a state before the electrode slurry 101a is dried, and the electrode 100 before being carried into the first heating zone 20A. It corresponds to. FIG. 4A shows a cross-sectional view of the electrode 100 taken along the line AA ′ in FIG. Such an electrode 100 is formed by applying the electrode slurry 101a with the thickness D1 to the current collector 102a having the lateral width W1 by the coater 91 of the electrode slurry application unit 90 described above. The electrode 100 at the position of the line B ′ is in a state where the electrode slurry 101b is in the middle of drying, and corresponds to the electrode 100 being transported, for example, in the sixth heating zone 20F of the drying unit 20. FIG. 4B is a cross-sectional view of the electrode 100 taken along the line BB ′ in FIG. The thickness D2 of the electrode slurry 101b of the electrode 100 is smaller than the thickness D1 shown in FIG. 4A as a result of evaporation of a part of the volatile solvent contained in the electrode slurry 101a. Here, both ends of the current collector 102b are drawn or bent or refracted by the dried and contracted electrode slurry 101b. Therefore, the lateral width W2 of the current collector 102b illustrated in FIG. 4B is shorter than the lateral width W1 of the current collector 102a illustrated in FIG.

  The electrode 100 at the position of the C-C ′ line shown in FIG. 3 is in a state where the drying of the electrode slurry 101 c has been completed, and corresponds to the electrode 100 being transported through, for example, the eighth heating zone 20 </ b> H of the drying unit 20. FIG. 4C is a cross-sectional view of the electrode 100 taken along the line C-C ′ in FIG. The thickness D3 of the electrode slurry 101c of such an electrode 100 is smaller than the thickness D2 shown in FIG. 4B as a result of the evaporation of most of the volatile solvent remaining in the electrode slurry 101b. Here, both ends of the current collector 102c are further bent or refracted by being attracted to the electrode slurry 101c that has been dried and contracted. Therefore, the lateral width W3 of the current collector 102c illustrated in FIG. 4C is shorter than the lateral width W2 of the current collector 102b illustrated in FIG.

  Here, the end of the current collector 102 of the electrode 100 shown in FIGS. 3 and 4 is bent or refracted according to the following principle. The electrode 100 is formed by, for example, applying the electrode slurry 101 to a current collector 102 having a thickness of 20 μm and a thickness of 200 μm, which is ten times that of the current collector 102, and then drying by heating. Along with this heating, the solvent in the electrode slurry 101 having a thickness sufficiently larger than that of the current collector 102 is dried while evaporating. As the electrode slurry 101 is dried in this manner, the thickness of the electrode slurry 101 becomes about half of the initial coating. Further, at the end of the drying of the electrode slurry 101, the surface of the electrode slurry 101 shrinks due to drying, and both ends of the current collector 102b are attracted and bent or refracted by the shrinkage stress.

  The graph relating to the electrode 100 shown in FIG. 5 shows the displacement of the end of the current collector 102 with respect to the evaporation rate of the solvent in the electrode slurry 101 for the electrode 100 coated on one side in the drying process shown in FIGS. Shows the percentage. The displacement rate of the end portion of the current collector 102 represents the reduction width of the lateral width of the current collector 102 shortened by bending or refraction as a percentage. Therefore, the evaporation rate when the volatile solvent contained in the electrode slurry 101 completely evaporates is 100%, and the displacement rate of the end when the end of the current collector 102 stops bending or refraction. It is defined as 100%. As shown in FIG. 5, the displacement rate of the end portion of the current collector 102 increases rapidly from the point where the evaporation rate of the volatile solvent contained in the electrode slurry 101 exceeds 90%. Here, the width W2 of the current collector 102b shown in FIG. 4B reflects the displacement rate of the end of the current collector 102 after the evaporation rate of the solvent shown in FIG. 5 exceeds 90%. . Further, the width W3 of the current collector 102c shown in FIG. 4C reflects the displacement rate of the end of the current collector 102 immediately before the evaporation rate of the solvent shown in FIG. 5 reaches 100%.

  The graph relating to the electrode 100 shown in FIG. 6 shows the dry state of the electrode slurry 101 in the electrode 100 applied to the single-side coated electrode 100 in the drying process shown in FIGS. 3 and 4. The electrode slurry 101 is dried through a temperature raising zone, a solvent evaporation zone, and a dry finishing zone as shown on the horizontal axis of FIG. Here, the residual ratio of the solvent in the electrode slurry 101 is 100% at the beginning of the temperature rising zone, but starts to decrease rapidly from the boundary between the temperature rising zone and the solvent evaporation zone, and reaches 0 in the latter half of the dry finishing zone. %become. The temperature of the electrode slurry 101 is room temperature at the beginning of the temperature raising zone, but rises from the temperature raising zone to the drying finishing zone, reaches 130 ° C. in the drying finishing zone, and suddenly exceeds the drying finishing zone. It drops to room temperature. The wind speed of the hot air supplied to the electrode slurry 101 is constant in the temperature raising zone. Next, the wind speed of the hot air is kept constant in the solvent evaporation zone after being lowered by a predetermined value when shifting from the temperature raising zone to the solvent evaporation zone. Furthermore, the wind speed of the hot air is rapidly increased after exceeding the finish drying zone, and is increased until it exceeds the finish drying zone.

  Next, regarding the drying of the electrode 100 by the drying unit 20, the electrode slurry 103 is applied to the other surface of the current collector 102 that has been dried by applying the electrode slurry 101 to one surface of the current collector 102. The case (double-sided coating) will be described with reference to FIGS.

  In the electrode 100 shown in the schematic perspective view of FIG. 7, the electrode 100 at the position of the AA ′ line is in a state before the electrode slurry 103a coated on both sides is dried, and is carried into the first heating zone 20A. This corresponds to the electrode 100 before being processed. FIG. 8A shows a cross-sectional view of the electrode 100 taken along the line A-A ′ of FIG. 7. Note that the end portion of the current collector 102 that has been bent or refracted in FIG. 4C is in the process of being wound and stored by the winding roll 17 of the transport unit 10 as shown in FIG. Refraction or refraction has been eliminated. Such an electrode 100 is formed by applying the electrode slurry 103a with a thickness D4 to the current collector 102a having the lateral width W1 by the coater 91 of the electrode slurry application unit 90 described above.

  The electrode 100 at the position of the B-B ′ line shown in FIG. 7 corresponds to the electrode 100 in which the electrode slurry 103 b is in the middle of drying and is transported through, for example, the sixth heating zone 20 </ b> F of the drying unit 20. FIG. 8B is a cross-sectional view of the electrode 100 taken along the line B-B ′ in FIG. The thickness D5 of the electrode slurry 103b of the electrode 100 is thinner than the thickness D4 shown in FIG. 8A as a result of evaporation of a part of the volatile solvent contained in the electrode slurry 103a. Here, both ends of the current collector 102b are drawn or bent or refracted by the dried and contracted electrode slurry 103b. Therefore, the lateral width W4 of the current collector 102b shown in FIG. 8B is shorter than the lateral width W1 of the current collector 102a shown in FIG.

  The electrode 100 at the position of the C-C ′ line shown in FIG. 7 is in a state where the drying of the electrode slurry 103 c has been completed, and corresponds to the electrode 100 being transported through, for example, the eighth heating zone 20 </ b> H of the drying unit 20. FIG. 8C is a cross-sectional view of the electrode 100 taken along the line C-C ′ in FIG. The thickness D6 of the electrode slurry 103c of such an electrode 100 is smaller than the thickness D5 shown in FIG. 8B as a result of almost volatile solvent remaining in the electrode slurry 103b being evaporated. Here, both ends of the current collector 102c are further bent or refracted by being attracted to the electrode slurry 103c that has dried and contracted. Therefore, the lateral width W5 of the current collector 102c illustrated in FIG. 8C is shorter than the lateral width W4 of the current collector 102b illustrated in FIG. 8B.

  The graph relating to the electrode 100 shown in FIG. 9 shows the displacement of the end portion of the current collector 102 with respect to the evaporation rate of the solvent in the electrode slurry 103 for the double-sided coated electrode 100 shown in FIGS. 7 and 8. Shows the percentage. The displacement ratio of the end portion of the current collector 102 is expressed by the ratio of the width of the current collector 102 that has been shortened by bending or refraction, with reference to FIG. As shown in FIG. 9, the displacement rate of the end portion of the current collector 102 is increased from the point where the evaporation rate of the volatile solvent contained in the electrode slurry 103 exceeds 90%. Here, the width W4 of the current collector 102b shown in FIG. 8B reflects the displacement rate of the end of the current collector 102 after the evaporation rate of the solvent shown in FIG. 9 exceeds 90%. . Further, the width W5 of the current collector 102c shown in FIG. 8C reflects the displacement rate of the end portion of the current collector 102 immediately before the evaporation rate of the solvent shown in FIG. 9 reaches 100%. In any case, the change in the displacement ratio in the drying stage is about half of the double-sided coating graph shown by the solid line in FIG. 9 compared to the single-sided coating graph shown by the dotted line in FIG. This is because, when the electrode slurry 103 is dried and contracted, the electrode slurry 101 that has already been applied to the current collector 102 and has been dried prevents the end of the current collector 102 from being bent or refracted. .

  As shown in FIG. 10, the measuring unit 30 of the electrode drying apparatus 1 measures the position of the end of the electrode 100 by a plurality of measuring means provided along one or both ends of the side of the transport path of the electrode 100.

  Here, in FIG. 10, in order to clarify the arrangement of each component of the measurement means in the measurement unit 30, most of the drying unit 20 is not illustrated, and 8 of the first heating zone 20 </ b> A to the eighth heating zone 20 </ b> H. Only one heating zone is indicated by the arrows. The measuring means of the measuring unit 30 includes a detector, and as shown in FIG. 11, a part of the light L1 emitted from the light emitting member 31 disposed on one side of the left end of the electrode surface of the electrode 100 is used as the electrode. Light is received by the light receiving member 33 disposed on the other side of the surface. Here, the electrode surface of the electrode 100 corresponds to a surface on which the electrode slurry 101 is applied to the current collector 102. Similarly, the measuring means of the measuring unit 30 receives a part of the light L2 emitted from the light emitting member 32 arranged on one side of the right end of the electrode surface of the electrode 100, and is received on the other side of the electrode surface. Light is received by the member 34. That is, FIG. 10 shows a configuration in which measuring means are provided along both ends on the side of the conveyance path of the electrode 100. A configuration of the measurement unit 30 and a method of measuring the position of the end of the electrode 100 by the measurement unit 30 will be described with reference to FIGS. 10 and 11.

  For example, the measurement unit 30 includes 20 sets of detectors from the center of the sixth heating zone 20F to the center of the eighth heating zone 20H at regular intervals along the transport direction of the electrode 100. Therefore, in the second half region of the sixth heating zone 20F, the whole region of the seventh heating zone 20G, and the first half region of the eighth heating zone 20H, the position of the end portion of the electrode 100 is detected using 20 sets of detectors. Can be measured continuously. Here, the 20 sets of detectors are respectively provided at both ends on the side of the transport path of the electrode 100. Specifically, as shown in FIG. 11, the light emitting member 31 and the light receiving member 33 of the detector are arranged above and below the electrode 100 so as to face each other while being separated from the left end of the electrode 100. Similarly, the light emitting member 32 and the light receiving member 34 of the detector are disposed above and below the electrode 100 so as to face each other in a state of being separated from the right end of the electrode 100.

  Here, the light emitting members 31 and 32 are arranged above the electrode 100, and the light receiving members 33 and 34 are arranged below the electrode 100. However, the arrangement is not limited to this, and the light emitting members 31 and 32 may be disposed below the electrode 100, and the light receiving members 33 and 34 may be disposed above the electrode 100. Specifically, for example, in the case where the detector is regularly maintained, the light receiving members 33 and 34 are positioned more than the electrode 100 so that the light incident on the light receiving members 33 and 34 can be easily visually confirmed. It should be placed on the lower side. On the other hand, for example, when the influence of disturbance light caused by a fluorescent lamp mounted on the ceiling or a satellite provided in the apparatus is large, the light receiving members 33 and 34 are connected to the electrode 100 so that the disturbance light can be easily blocked. Is also preferably arranged on the upper side.

  Such light emitting members 31 and 32 are provided with, for example, a laser diode or a light emitting diode as a light source. The light emitting members 31 and 32 have the same specifications. Here, the light emitted from the laser diode has less light diffraction and higher straightness than the light emitted from the light emitting diode. Therefore, if a laser diode is used as the light source, it is possible to reduce detection errors when light is received by the light receiving members 33 and 34 described later. In addition, the light emitting members 31 and 32 have a configuration in which, for example, light emitted from a laser diode or a light emitting diode is converted into parallel light having a constant emission width by using a collimator lens. Further, the light emitting members 31 and 32 are configured so that light emitted from the laser diode is reflected by a rotating mirror whose outer periphery is formed into a polyhedron so that light can be scanned linearly in a certain region. Can do.

  The wavelength of the light emitted from the light emitting members 31 and 32 can be selected from the region of ultraviolet light, visible light, or infrared light. Here, when ultraviolet rays are selected as the wavelength of light, it becomes easy to detect separately from infrared rays emitted from the heat source provided in the drying unit 20. In addition, when visible light is selected as the wavelength of light, the light can be visually recognized, which facilitates optical adjustment of the detector. On the other hand, when infrared light is selected as the wavelength of light, the light is less attenuated due to transmission and reflection than ultraviolet light and visible light, so that it is possible to suppress a decrease in light intensity due to a window plate or the like. . Furthermore, when an infrared ray is selected as the wavelength of light, the influence can be avoided by providing a color filter that does not transmit disturbance light such as ultraviolet rays and visible rays.

  Further, the light receiving members 33 and 34 are provided with, for example, a plurality of linearly adjacent Si photodiodes or a CCD image sensor having a light receiving surface having a rectangular shape as light receiving elements. The light receiving members 33 and 34 have the same specifications. In addition, when using a Si photodiode, a specification in which the horizontal width of one pixel is several hundred μm is selected. Similarly, when a CCD image sensor is used, a specification in which the width of one pixel is several tens to several hundreds of μm is selected. Such a horizontal width of one pixel is a resolution related to a light detection position by the light receiving members 33 and 34. Here, if the lights L1 and L2 are reflected at the end of the current collector 102f, the reflected light may enter the light receiving member 33 or 34 and become noise. In such a case, for example, a polarizing filter is provided in front of the light receiving members 33 and 34 to shield the reflected light.

  The detector of the measurement unit 30 described above is provided adjacent to the drying unit 20. Here, in the drying part 20, in order to control internal temperature to a predetermined value, it is necessary to insulate with the surrounding structure. Therefore, the light emitting members 31 and 32 are disposed, for example, through a transparent heat-resistant glass (not shown) provided at the top of the drying unit 20. In this case, the light receiving members 33 and 34 are disposed over the transparent heat-resistant glass provided at the lower portion of the drying unit 20 so as to face the light emitting members 31 and 32. Moreover, since this heat-resistant glass may become clouded by the solvent evaporated from the electrode slurry 101, for example, a wiper is provided.

  Further, a method for measuring the position of the end portion of the electrode 100 by the measurement unit 30 will be described. The electrode 100 shown in FIG. 11 is formed of an electrode slurry 101f in which a certain amount of solvent is dried and a current collector 102f whose end is bent as the solvent in the electrode slurry 101f is dried. Here, the end portion of the electrode 100 corresponds to the end portion of the current collector 102 f constituting the electrode 100. As shown in FIG. 11, a part of the light L1 emitted from the light emitting member 31 with the emission width H1 is not shielded by the left end portion of the current collector 102f in the drawing, and the light receiving member 33 with the incident width H3. Is incident on. Similarly, as shown in FIG. 11, a part of the light L2 emitted from the light emitting member 32 with the emission width H2 is not shielded by the right end of the current collector 102f in the drawing, but with the incident width H4. The light enters the light receiving member 34. In addition, when the light beams of the lights L1 and L2 are illustrated in FIG. 10 for 20 sets of detectors, these light beams are concentrated. Therefore, in FIG. 10, the light beams L1 and L2 are illustrated only for three sets of detectors near both ends and the center of the 20 sets of detectors.

  Here, in the measurement unit 30, the displacement amount R1 of the end of the current collector 102f is calculated by the following equation (1).

  This displacement amount R1 corresponds to one side of the reduced width related to the lateral width of the current collector 102f whose both ends are bent or refracted. Specifically, the displacement amount R1 is a value obtained by subtracting the lateral width W1 of the current collector 102a shown in FIG. 4A by the lateral width W6 of the current collector 102f shown in FIG. Thus, even if the amount of bending or refraction is different between the right end portion and the left end portion of the current collector 102f, the displacement amount R1 is an average value of the reduction width of the current collector 102f due to the bending or refraction. calculate. Further, according to such a configuration, even when the electrode 100 is conveyed while meandering with respect to the normal direction of the conveyance direction, the measurement means is provided at both ends of the side of the conveyance path of the electrode 100. The displacement amount R1 can be calculated without being affected by the meandering.

  In the measurement unit 30 described above, as shown in FIG. 10, by providing measurement means along both lateral ends of the conveyance path of the electrode 100, the electrode 100 is conveyed while meandering with respect to the normal direction of the conveyance direction. Even if it is, it is configured not to be affected by the meandering. On the other hand, in the case where the electrode 100 can be transported without meandering with respect to the normal direction of the transport direction, the measuring means of the measuring unit 30 is provided along only one side of the transport path of the electrode 100. It is good. Here, in order to prevent meandering of the electrode 100, for example, a sensor that detects the position of the end of the electrode 100 is provided in the transport unit 10 adjacent to the drying unit 20, and the supply roll is based on the detection result by the sensor. 11 is moved with respect to the normal direction of the conveying direction of the electrode 100.

  Next, the measurement unit 40 will be described. The measurement unit 40 is disposed in the electrode drying apparatus 2 according to the first embodiment shown in FIG. 12, and corresponds to another form of the measurement unit 30 described above.

  Such a measuring unit 40 has fewer constituent members and can be easily optically adjusted compared to the measuring unit 30 provided with measuring means along both lateral ends of the transport path of the electrode 100. Such labor can be greatly reduced. In the electrode drying apparatus 2, the configuration other than the measurement unit 40 is the same as that of the electrode drying apparatus 1.

  As shown in FIG. 12, the measurement unit 40 measures the position of the end of the electrode 100 by a plurality of measurement means provided above or below the conveyance path of the electrode 100. In addition, in FIG. 12, in order to clarify arrangement | positioning of the measurement means of the measurement part 40 like FIG. 10, most illustration of the drying part 20 is abbreviate | omitted and the 1st heating zone 20A-8th heating zone 20H. These eight heating zones are shown by arrows. The measuring means of such a measuring unit 40 has an imager, and images the electrode 100 from the electrode surface side as shown in FIG. A configuration of the measurement unit 40 and a method of measuring the position of the end of the electrode 100 by the measurement unit 40 will be described with reference to FIGS. 12 and 13.

  Here, similarly to the measurement unit 30, for example, the measurement unit 40 is configured so that 20 sets of imagers are fixed along the conveyance direction of the electrode 100 from the center of the sixth heating zone 20F to the center of the eighth heating zone 20H. Provided at intervals. Accordingly, in the second half area of the sixth heating zone 20F, the whole area of the seventh heating zone 20G, and the first half area of the eighth heating zone 20H, the position of the end portion of the electrode 100 is set using 20 sets of imagers. Can be measured continuously.

  A CCD camera 41 is used for the image pickup device of the measurement unit 40. The CCD camera 41 receives the light L3 reflected from the electrode 100, and measures the position of the end of the electrode 100. Specifically, the position of the end of the electrode 100 is detected from the image of the electrode 100 obtained by the CCD camera 41 based on the difference in color tone and reflectance from the surrounding structure. For the resolution of the CCD camera 41, a specification of several tens of μm to several hundreds of μm is selected. Here, the CCD camera 41 is disposed over a transparent heat-resistant glass (not shown) provided at the top of the drying unit 20. Moreover, since this heat-resistant glass may become clouded by the solvent evaporated from the electrode slurry 101, for example, a wiper is provided. Further, since the CCD camera 41 interferes with the upper nozzle 24 of the drying unit 20 shown in FIG. 1, the shape of the upper nozzle 24 is partially changed so that the CCD camera 41 can be disposed.

  Furthermore, the measuring method of the position of the edge part of the electrode 100 by the measurement part 40 is demonstrated. An electrode 100 shown in FIG. 13 is formed of an electrode slurry 101g in which a certain amount of solvent is dried and a current collector 102g whose end is bent as the solvent in the electrode slurry 101g is dried. Here, the end portion of the electrode 100 corresponds to the end portion of the current collector 102 g constituting the electrode 100. In addition, when the light beams of the light L3 are illustrated in FIG. 12 for 20 sets of imagers, the light beams are concentrated. Therefore, in FIG. 12, the light beam L3 is illustrated only for the three sets of imagers near both ends and the center of the 20 sets of imagers.

  Here, in the measurement unit 40, the displacement amount R2 of the end of the current collector 102g is calculated by the following equation (2).

  This displacement amount R2 corresponds to one side of the reduced width related to the lateral width of the current collector 102g whose both ends are bent or refracted. Specifically, the displacement amount R2 is a value obtained by subtracting the lateral width W1 of the current collector 102a shown in FIG. 4A by the lateral width W7 of the current collector 102g shown in FIG. Thus, even if the amount of bending or refraction differs between the right end portion and the left end portion of the current collector 102g, the displacement amount R2 is an average value of the reduction width of the current collector 102g due to the bending or refraction. calculate. Further, according to such a configuration, even if the electrode 100 is conveyed while meandering with respect to the normal direction of the conveyance direction, since both ends of the electrode 100 are imaged by the imaging device, the influence of the meandering is affected. The displacement amount R2 can be calculated without receiving it.

  Next, the measurement unit 50 will be described. The measurement unit 50 is disposed in the electrode drying apparatus 3 according to the first embodiment shown in FIG. 14, and corresponds to still another form of the measurement unit 30 described above.

  Such a measuring unit 50 can halve the configuration of the detector as compared to the measuring unit 30 provided with measuring means along both lateral ends of the transport path of the electrode 100. In the electrode drying apparatus 3, the configuration other than the measurement unit 50 is the same as that of the electrode drying apparatus 1.

  As shown in FIG. 14, the measurement unit 50 measures the position of the end of the electrode 100 by a plurality of measurement means provided along the side of the conveyance path of the electrode 100. In addition, in FIG. 14, in order to clarify arrangement | positioning of each structure of the measurement means of the measurement part 50 like FIG. 10, most illustration of the drying part 20 is abbreviate | omitted and the 1st heating zone 20A-8th. The eight heating zones of the heating zone 20H are only indicated by arrows. The measuring means of the measuring section 50 has a detector, and as shown in FIG. 15, a part of the light L4 emitted from the light emitting member 51 disposed on one side of the electrode 100 is used as the electrode. Light is received by a light receiving member 52 disposed on the other side of the side surface of 100. Here, the side surface of the electrode 100 corresponds to a surface in the thickness direction of the current collector 102 and the electrode slurry 101 applied to the current collector 102. A configuration of the measurement unit 50 and a method of measuring the position of the end of the electrode 100 by the measurement unit 50 will be described with reference to FIGS. 14 and 15.

  Here, similarly to the measurement unit 30, for example, the measurement unit 50 includes 20 sets of detectors from the center of the sixth heating zone 20F to the center of the eighth heating zone 20H along the transport direction of the electrode 100. Provided at intervals. Therefore, in the second half region of the sixth heating zone 20F, the whole region of the seventh heating zone 20G, and the first half region of the eighth heating zone 20H, the position of the end portion of the electrode 100 is detected using 20 sets of detectors. Can be measured continuously.

  The light emitting member 51 of the detector is provided with, for example, a laser diode as a light source. In addition, the light emitting member 51 has a configuration in which light emitted from the laser diode is converted into parallel light having a constant emission width by using a collimator lens. The light receiving member 52 of the detector is provided with, for example, a plurality of linearly adjacent Si photodiodes or a CCD image sensor having a light receiving surface having a rectangular shape as light receiving elements. Here, the light emitting member 51 is disposed over a transparent heat-resistant glass (not shown) provided on one side of the drying unit 20. The light receiving member 52 is disposed over the transparent heat-resistant glass provided on the other side of the drying unit 20 so as to face the light emitting member 51. Moreover, since this heat-resistant glass may become clouded by the solvent evaporated from the electrode slurry 101, for example, a wiper is provided.

  Further, a method for measuring the position of the end portion of the electrode 100 by the measurement unit 50 will be described. The electrode 100 shown in FIG. 15 is formed of an electrode slurry 101h in which a certain amount of solvent is dried, and a current collector 102h whose end is bent as the solvent in the electrode slurry 101h is dried. Here, the end portion of the electrode 100 corresponds to the end portion of the current collector 102 h constituting the electrode 100. As shown in FIG. 15, a part of the light L4 emitted from the light emitting member 51 is shielded by the current collector 102h, so that a light shielding width H5 is generated in the light receiving member 52. In addition, if the light beams of the light L4 are illustrated in FIG. 14 for 20 sets of detectors, those light beams are densely gathered. Therefore, in FIG. 14, the light beam L4 is illustrated only for the three sets of detectors near both ends and the center of the 20 sets of detectors.

  Here, in the measurement unit 50, the displacement amount R3 of the end of the current collector 102h is calculated by the following equation (3).

  This displacement amount R3 corresponds to an increase width in the height direction corresponding to the thickness of the current collector 102h where both ends are bent or refracted. Here, when the end portion of the current collector 102h is bent or refracted over a long section, the displacement amount R3 in the height direction is larger than the displacement amount R1 in the lateral direction described above with reference to FIG. Therefore, it is easy to detect the displacement amount R3. Further, according to such a configuration, even if the electrode 100 is conveyed while meandering with respect to the normal direction of the conveyance direction, the detector detects an increase width in the height direction corresponding to the thickness of the current collector 102h. Therefore, the displacement amount R3 can be calculated without being affected by the meandering. Further, the displacement R3 is calculated as a large value when the right end portion and the left end portion of the current collector 102f have different bending or refraction sizes.

  The drying determination unit 60 of the electrode drying apparatus 1 determines the dry state of the electrode 100 based on the amount of displacement of the position of the end of the electrode 100.

  The drying determination unit 60 includes a controller 61 as shown in FIG. Here, the controller 61 includes a CPU, a ROM, and a RAM. A CPU (Central Processing Unit) executes a control program stored in the ROM. A ROM (Read Only Memory) stores a control program for determining the dry state of the electrode 100. A RAM (Random Access Memory) temporarily stores measurement data of the position of the end of the electrode 100 in accordance with the execution of the control program by the CPU. Here, the controller 61 determines the dry state of the electrode 100 based on the amount of change in the position of the end of the electrode 100 measured by the measurement units 30 to 50. Specifically, for example, as a reference table, the displacement ratio of the end portion of the current collector 102 of the electrode 100 shown in FIG. 5 is stored in the ROM. In addition, the controller 61 compares the amount of change in the position of the end of the electrode 100 measured by the measuring units 30 to 50 with the value of the reference table stored in the ROM. Determine the dry state.

  According to the electrode drying method of the first embodiment described above and the electrode drying apparatuses 1 to 3 equipped with the electrode drying method, the following effects can be obtained.

  The position of the end of the electrode 100 is measured by the measuring means provided in the measuring units 30 to 50 of the electrode drying apparatuses 1 to 3, and provided in the drying determination unit 60 based on the amount of displacement of the position of the end of the electrode 100. The controller 61 determines the dry state of the electrode 100. Therefore, even if the electrode 100 is continuously dried, the quality of the electrode 100 can be ensured.

  Specifically, in the electrode 100, the surface of the electrode slurry 101 contracts due to drying, and both ends of the current collector 102b are drawn and bent or refracted by the contraction stress. Since such a phenomenon occurs quantitatively with good reproducibility when the electrode 100 is dried, the method for determining the dry state of the electrode 100 based on the displacement amount of the position of the end of the electrode 100 has high reliability. .

  Further, as shown in FIG. 10, the measuring unit 30 of the electrode drying apparatus 1 includes a plurality of measuring means (light emitting members 31 and 32 and light receiving members 33 and 34) provided along both lateral ends of the transport path of the electrode 100. Thus, the position of the end portion of the electrode 100 is measured. According to such a method for measuring the position of the end of the electrode 100, the measurement means can be constructed with an easy configuration, and does not interfere with each component of the drying unit 20, and maintains high measurement accuracy. be able to. In particular, the specifications of the light emitting members 31 and 32 and the light receiving members 33 and 34 constituting the measuring means can be arbitrarily selected according to the installation environment of the electrode drying apparatus 1 and the like. Further, according to such a configuration, even when the electrode 100 is conveyed while meandering with respect to the normal direction of the conveyance direction, the measurement means is provided at both ends of the side of the conveyance path of the electrode 100. The displacement amount R1 can be calculated without being affected by the meandering.

  Further, as shown in FIG. 12, the measurement unit 40 of the electrode drying apparatus 2 is provided with a plurality of measurement means (CCD camera 41) provided above or below the conveyance path of the electrode 100 to position the end of the electrode 100. Measure. According to such a method for measuring the position of the end of the electrode 100, since the measuring means has only the CCD camera 41 and the number of constituent members and optical adjustment is easy, the labor for assembly adjustment can be greatly reduced. Can do. Further, according to such a configuration, even if the electrode 100 is conveyed while meandering with respect to the normal direction of the conveyance direction, since both ends of the electrode 100 are imaged by the imaging device, the influence of the meandering is affected. The displacement amount R2 can be calculated without receiving it.

  Further, as shown in FIG. 14, the measuring unit 50 of the electrode drying apparatus 3 includes a plurality of measuring means (light emitting member 51 and light receiving member 52) provided along the side of the conveyance path of the electrode 100, so Measure the position of the part. Such a measuring unit 50 can halve the configuration of the detector as compared to the measuring unit 30 provided with measuring means along both lateral ends of the transport path of the electrode 100. Further, according to such a configuration, even if the electrode 100 is conveyed while meandering with respect to the normal direction of the conveyance direction, the detector detects an increase width in the height direction corresponding to the thickness of the current collector 102h. Therefore, the displacement amount R3 can be calculated without being affected by the meandering.

Second Embodiment
The electrode drying control device 4 according to the second embodiment is a control device that dries an electrode 100 formed by applying an electrode slurry 101 containing a volatile solvent on a current collector 102 at a predetermined position.

  That is, the electrode drying control device 4 according to the second embodiment is a control device that dries the electrode 100 at a predetermined position in the drying device, unlike the electrode drying devices 1 to 3 according to the first embodiment. As shown in FIG. 16, such an electrode drying control device 4 includes a transport unit 10, a drying unit 70, measurement units 30 to 50, and a drying control unit 80. Hereinafter, in the second embodiment, a configuration unique to the electrode drying control device 4 and a method for drying the electrode 100 unique to the electrode drying control device 4 will be described.

  The drying unit 70 of the electrode drying control device 4 dries the electrode 100 with a drying means. The drying means corresponds to, for example, a heat exchanger 71 and an infrared lamp 73 described later, but is not particularly limited as long as the electrode 100 can be dried. Here, the drying unit 70 varies the temperature control in the first heating zone 70 </ b> A and the second heating zone 70 </ b> B of the drying unit 70 based on the control by the drying control unit 80. Here, even if the drying unit 20 is used, the temperature control in the first heating zone 20A and the second heating zone 20B can be varied. However, in order to facilitate understanding of the configuration related to drying in the electrode drying control device 4, a description will be given using the drying unit 70.

  The basic configuration of the drying unit 70 is the same as the configuration of the drying unit 20. As shown in FIG. 16, the drying unit 70 includes eight heating zones of the first heating zone 70 </ b> A to the eighth heating zone 70 </ b> H from the upstream side to the downstream side of the transport unit 10, and is controlled independently. Here, the temperature control in the first heating zone 70A and the second heating zone 70B of the drying unit 70 is separately controlled by the drying control unit 80 in addition to the control by the drying unit 70 itself. In the drying unit 70, an infrared lamp 73 is provided in each of the upper nozzles 74 of the first heating zone 70A and the second heating zone 70B. Further, in the drying unit 70, a heat exchanger 71 is provided in the lower nozzle 72 of the first heating zone 70A to the eighth heating zone 70H. The operation of the drying unit 70 will be described later with reference to FIG.

  The drying control unit 80 of the electrode drying control device 4 determines the drying state of the electrode 100 based on the displacement amount of the position of the end of the electrode 100, and the drying of the electrode 100 is completed at a position within a predetermined range in the transport path. Thus, the drying means of the drying unit 70 is controlled. Accordingly, the drying control unit 80 controls the drying unit of the drying unit 70 so that the drying of the electrode 100 is completed at a position within a predetermined range in the transport path, in addition to the determination in the drying determination unit 60 described above. Such a drying control unit 80 is provided with a controller 81 as shown in FIG. Here, the controller 81 includes a CPU, a ROM, and a RAM. A CPU (Central Processing Unit) executes a control program stored in the ROM. A ROM (Read Only Memory) stores a control program for determining the dry state of the electrode 100 and controlling the drying unit 70 so that the drying of the electrode 100 is completed at a position within a predetermined range in the transport path. doing. A RAM (Random Access Memory) temporarily stores data related to the position of the end of the electrode 100 and the degree of drying generated by the execution of the control program by the CPU. The control of the drying unit 70 by the drying control unit 80 will be described later with reference to FIG.

  Next, control of the drying means of the drying unit 70 by the drying control unit 80 will be described with reference to FIG.

  FIG. 17 is a flowchart showing the control of using the electrode drying control device 4 to place the drying position of the electrode 100 at a position within a predetermined range in the transport path of the electrode 100.

  First, the position of the end of the electrode 100 is measured by the 20 sets of detectors of the measuring unit 30 (step S1). Subsequently, the drying control unit 80 determines the drying completion position of the electrode 100. Specifically, for example, as a reference table, the displacement ratio of the end of the current collector 102 of the electrode 100 as shown in FIG. After that, the controller 81 compares the amount of change in the position of the end of the electrode 100 measured by the 20 sets of detectors of the measuring unit 30 with the value of the reference table stored in the ROM. Furthermore, the controller 81 confirms the dry state of the electrode 100 from the comparison result, and determines the drying completion position of the electrode 100 in the transport path (step S2).

  Subsequently, if the determination result of “determination value> target upper limit position” is Yes in the drying completion position of the electrode 100 determined in step S2, the process proceeds to step S4, and if the determination result is No, the process proceeds to step S5 (step S5). S3). Subsequently, when the process proceeds from step S3 to step S4, if the determination result of “target upper limit position> determination value” is Yes at the drying completion position of the electrode 100 determined in step S2, the control is completed. In this case, the process proceeds to step S6 (step S4).

  Subsequently, when the process proceeds from step S3 to step S5, the drying control unit 80 increases the output of the infrared lamp 73 and increases the temperature of the amount of heat supplied from the heat exchanger 71. By such control, the drying completion position of the electrode 100 is shifted to the upstream side with respect to the drying path of the electrode 100 (step S5). Subsequently, when the process proceeds from step S4 to step S6, the drying control unit 80 lowers the output of the infrared lamp 73 and lowers the temperature of the amount of heat supplied from the heat exchanger 71. By such control, the drying completion position of the electrode 100 is shifted downstream with respect to the drying path of the electrode 100 (step S6).

  According to the electrode drying control method of the second embodiment described above and the electrode drying control device 4 equipped with the electrode drying method, the following effects can be obtained.

  The position of the end portion of the electrode 100 is measured by the measuring unit 30 of the electrode drying control device 4, and the electrode 100 is dried by the controller 81 provided in the drying control unit 80 based on the displacement amount of the end portion of the electrode 100. After determining the state, the electrode 100 is dried at a predetermined position in the drying apparatus. Therefore, even when the electrode 100 is continuously dried, the drying operation can be prevented from being completed when the electrode 100 is not yet dried, and the drying of the electrode 100 is reliably completed in the drying apparatus. Can be made.

  Furthermore, according to the electrode drying control method and the electrode drying control apparatus 4 equipped with the electrode drying method, even when the electrode 100 is continuously dried, the drying of the electrode 100 is completed. Nevertheless, the drying operation is not continued. Therefore, according to the electrode drying control device 4, it is possible to prevent the conveyance path of the electrode 100 in the drying device from being unnecessarily lengthened.

  In particular, according to the electrode drying control method and the electrode drying control device 4 equipped with the electrode drying method, the length of the transport path of the electrode 100 in the drying device does not have an originally unnecessary margin. The apparatus can be reduced in size and the energy used can also be suppressed.

  In the first embodiment and the second embodiment, the electrode slurry 101 is continuously applied to the current collector 102 using the coater 91 of the electrode slurry application unit 90, but this is the case. It is not limited to a simple configuration. For example, the electrode slurry 101 may be intermittently applied to the current collector 102 using the coater 91 of the electrode slurry application unit 90.

  Moreover, in 1st Embodiment and 2nd Embodiment, although the electrode 100 always conveyed by the conveyance part 10 was demonstrated as a structure dried continuously, it is not limited to such a structure. For example, the electrode 100 may be configured to be dried in a batch manner so that the process of drying the electrode 100 in a state where the electrode 100 is temporarily stopped after being transported by a certain distance by the transport unit 10 is repeated a plurality of times.

  Moreover, in 1st Embodiment and 2nd Embodiment, although demonstrated as a structure which uses a laser diode for the light source provided in the measurement parts 30 and 50, for example, it is not limited to such a structure. For example, a CCD camera 41 may be provided in the measurement units 30 and 50, and the position of the end of the electrode 100 may be imaged and measured.

  Further, in the second embodiment, in order to dry the electrode 100 at a predetermined position in the drying apparatus, the heat exchanger 71 and the infrared lamp 73 corresponding to the drying means of the drying unit 70 are used by using the drying control unit 80. Although described as the configuration to be controlled, it is not limited to such a configuration. For example, only the heat exchanger 71 of the drying unit 70 may be controlled using the drying control unit 80, or only the infrared lamp 73 of the drying unit 70 may be controlled.

  In addition, the present invention can be variously modified based on the configurations described in the claims, and it goes without saying that these are also within the scope of the present invention.

1,2,3 electrode drying device,
4 electrode drying control device,
10 Conveying section,
20 Drying section,
22 Heating heater (drying means),
30 measuring section,
31, 32 light emitting member,
33, 34 light receiving member,
40 measuring unit,
50 measuring section,
51 light emitting member,
52 light receiving member,
60 Drying determination unit,
70 drying section,
71 heat exchanger (drying means),
73 Infrared lamp (drying means),
80 Drying control unit,
100 electrodes,
101, 101a, 101b, 101c, 101f, 101g, 101h, 103, 103a, 103b, 103c electrode slurry,
102, 102a, 102b, 102c, 102f, 102g, 102h Current collector.

Claims (7)

A method of drying an electrode formed by applying an electrode slurry containing a volatile solvent on a current collector with a drying device,
A transporting process for transporting the electrodes;
A drying step of drying the electrode by a drying means;
A measuring step of measuring the position of the end of the electrode by a measuring means provided along the transport path of the electrode;
A drying determination step of determining a dry state of the electrode based on a displacement amount of an end position of the electrode. The measuring means includes a detector that receives a part of light emitted from a light emitting member disposed on one side of the electrode surface of the electrode by a light receiving member disposed on the other side of the electrode surface, Provide multiple each along one side or both ends of the side of the electrode transport path,
The electrode drying method according to claim 1, wherein, in the measurement step, the position of the end portion of the current collector bent or refracted as the solvent is dried is measured by the detector. The measuring means includes an imager that images the electrode from the electrode surface side, and a plurality of the measuring means are provided above or below the transport path of the electrode,
The electrode drying method according to claim 1, wherein in the measurement step, the position of the end of the current collector that is bent or refracted as the solvent is dried is measured by the imaging device. The measuring means includes a detector that receives a part of light emitted from a light emitting member arranged on one side of the side surface of the electrode by a light receiving member arranged on the other side of the side surface, Provide multiple along the side of the transport path,
The electrode drying method according to claim 1, wherein, in the measurement step, the position of the end portion of the current collector bent or refracted as the solvent is dried is measured by the detector. A control method of drying an electrode formed by applying an electrode slurry containing a volatile solvent on a current collector at a predetermined position of a drying device,
A transporting process for transporting the electrodes;
A drying step of drying the electrode by a drying means;
A measuring step of measuring the position of the end of the electrode by a measuring means provided along the transport path of the electrode;
A drying control step of determining a drying state of the electrode based on a displacement amount of an end position of the electrode, and controlling the drying means so that the drying of the electrode is completed at a position within a predetermined range in the transport path; And an electrode drying control method. An apparatus for drying an electrode formed by applying an electrode slurry containing a volatile solvent to a current collector,
A transport section for transporting the electrodes;
A drying section for drying the electrode by a drying means;
A measuring unit for measuring the position of the end of the electrode by a measuring means provided along the transport path of the electrode;
An electrode drying apparatus comprising: a dry determination unit that determines a dry state of the electrode based on a displacement amount of an end position of the electrode. A control device for drying an electrode formed by applying an electrode slurry containing a volatile solvent on a current collector at a predetermined position,
A transport section for transporting the electrodes;
A drying section for drying the electrode by a drying means;
A measuring unit for measuring the position of the end of the electrode by a measuring means provided along the transport path of the electrode;
A drying control unit that determines a drying state of the electrode based on a displacement amount of an end position of the electrode, and controls the drying unit so that the drying of the electrode is completed at a position within a predetermined range in the transport path; An electrode drying control device.

Images