JP2018081769A - Electrode inspection method and electrode inspection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrode inspection method and an electrode inspection device which are arranged so that a basis weight of a coating part of a second layer material can be acquired without being influenced by a first layer.SOLUTION: An electrode inspection method comprises: an electrode inspection step of disposing a measurement sheet 19 on a belt-shaped electrode 16 arranged by forming an active material layer 12 on each face of a long belt shape of metal foil 11 so as to partially cover the active material layer 12; then, applying a ceramic slurry 17 to a surface of the active material layer 12, and a surface of the measurement sheet 19 to form a coating part 18 which is a precursor of a protection layer, provided that the coating part 18 has a first coating part 18a formed on the surface of the active material layer 12, and a second coating part 18b formed on the surface of the measurement sheet 19; then, removing the measurement sheet 19 with the second coating part 18b formed thereon from the belt-shaped electrode 16, and measuring a weight of the measurement sheet 19 and a weight of the second coating part 18b; and calculating a basis weight of the coating part 18 from the measured weights.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an electrode inspection method and inspection apparatus having a current collector, a first layer present on both or one side of the current collector, and a second layer present on the surface of the first layer.

  As an example of an electrode used for a secondary battery as a power storage device, a metal foil as a current collector, an active material layer as a first layer present on both sides or one side of the metal foil, and a surface of the active material layer An electrode having a protective layer as a second layer is known (see, for example, Patent Document 1). In the electrode having such a configuration, it is necessary to obtain the basis weight of the coating portion of the second layer material during the manufacturing process of the electrode in order to inspect whether or not the formation state of the coating portion of the second layer material is good. is there.

  A method for acquiring the basis weight is disclosed in Patent Document 2, for example. The electrode described in Patent Literature 2 includes a backup base material and powder that is compression-formed on the surface of the backup base material. In Patent Document 2, the basis weight of the powder is obtained from the measurement result of the film thickness sensor.

Japanese Patent Laid-Open No. 2006-72025 JP 2014-191880 A

  However, in such a method for obtaining the basis weight, when the film thickness of the backup base material varies, the film thickness of the electrode measured by the film thickness sensor also varies, and the acquired powder The basis weight may be affected by the backup base material. In particular, when the above method is applied to the electrode described in Patent Document 1, since the first layer is formed on both sides or one side of the current collector, the basis weight of the coated portion of the obtained second layer material Is more easily affected by the first layer, and it is difficult to accurately obtain the basis weight of the coating portion of the second layer material.

  The present invention has been made to solve the above-mentioned problems, and the object thereof is to inspect an electrode inspection method capable of obtaining the basis weight of the coating portion of the second layer material without being affected by the first layer, and An object of the present invention is to provide an electrode inspection apparatus.

  An electrode inspection method for solving the above problem includes a current collector, a first layer present on both surfaces or one surface of the current collector, and a second layer present on the surface of the first layer. A method for inspecting an electrode, wherein a measurement sheet is applied to a part of a portion where a second layer material is applied later to a strip electrode in which the first layer is formed on both sides or one side of the current collector. Arrangement step to be arranged, and after the arrangement step, the second layer material is applied to the surface of the first layer and the surface of the measurement sheet to form a coating portion which is a precursor of the second layer. A coating step, a removal step of removing the measurement sheet on which the coating portion has been formed from the strip electrode, the measurement sheet removed in the removal step, and a coating formed on the measurement sheet Measuring the weight of the part and the weight of the coated part from the weight measured in the measuring step A calculation step of calculating an amount, to include the subject matter.

  According to this, since the basis weight of the coating part of the second layer material is calculated from the weight of the coating part formed on the measurement sheet and the measurement sheet, it is influenced by the basis weight of the first layer. There is nothing. Moreover, if the arrangement | positioning process and removal process of a sheet | seat for a measurement are performed with the production line of an electrode operated, the fabric weight of the coating part of a 2nd layer material can be acquired, without reducing the productivity of an electrode.

Moreover, about the said inspection method of an electrode, it is preferable in the said arrangement | positioning process that the said sheet | seat for a measurement is affixed on the said strip | belt-shaped electrode by an adhesive means.
According to this, the shift | offset | difference of the measurement sheet | seat with respect to a strip | belt-shaped electrode is suppressed.

Moreover, it is preferable that the said inspection method of an electrode has a drying process which dries the said coating part before the said removal process.
According to this, if what is evaporated in the drying process is adopted as the bonding means, it is not necessary to consider the weight of the bonding means in the calculation process.

Moreover, it is preferable that the said inspection method of the electrode includes the determination process which determines the quality of the formation state of the said coating part based on the fabric weight of the said coating part calculated at the said calculation process.
According to this, the quality of the formation state of the coating part of the second layer material can be determined. The determination result can be used for feedback to the coating process and selection of non-defective / defective products of the electrode on which the second layer is formed.

Moreover, about the said inspection method of an electrode, it is preferable to arrange | position the said sheet | seat for a measurement so that it may have a part which protrudes from the said strip | belt-shaped electrode in the said arrangement | positioning process.
According to this, in the process of removing the measurement sheet, the measurement sheet can be easily removed by gripping the portion protruding from the strip electrode.

In the electrode inspection method, the first layer is preferably an active material layer, and the second layer is preferably a protective layer made of a ceramic material as the second layer material.
According to this, when a plurality of electrodes whose first layer is an active material layer are stacked, the insulating function between the electrodes can be enhanced by the protective layer which is the second layer.

In the electrode inspection method, the measurement sheet is preferably made of the same material as the current collector.
According to this, it is not necessary to prepare a separate material for the measurement sheet.

Moreover, about the said inspection method of an electrode, it is preferable to use a gravure coating apparatus for the said coating process.
In coating using a gravure coating apparatus, the weight per unit area of the coating part depends on the rotation speed of the gravure roll. For this reason, if the coating process is performed in a state where the rotation speed of the gravure roll is constant, even if the thickness of the strip electrode varies due to the arrangement of the measurement sheet, it is formed in the first layer of the strip electrode. The same weight per unit area can be achieved in the coating portion and the coating portion formed on the measurement sheet. Moreover, when changing the fabric weight of the coating part of 2nd layer material, it is only necessary to change the rotation speed of a gravure roll, and a complicated adjustment operation is not required.

  An electrode inspection apparatus for solving the above problems includes a current collector, a first layer present on both surfaces or one surface of the current collector, and a second layer present on the surface of the first layer. An inspection apparatus for an electrode for inspecting an electrode, wherein the second layer material is applied to a part of a strip electrode in which the first layer is formed on both sides or one side of the current collector. The second layer material is applied to the arrangement device for arranging the measurement sheet, the surface of the first layer, and the surface of the measurement sheet arranged on the belt-like electrode. After a certain coating portion is formed, a removal device that removes the measurement sheet on which the coating portion is formed from the strip electrode, the removed measurement sheet, and the coating formed on the measurement sheet A measuring unit for measuring the weight of the working part, and the weight measured by the measuring unit And summarized in that with a measuring device provided with a calculation unit for calculating a weight per unit area of the coated portion.

  According to this, since the basis weight of the coating part of the second layer material is calculated from the weight of the coating part formed on the measurement sheet and the measurement sheet, it is influenced by the basis weight of the first layer. There is nothing. Further, if the inspection apparatus is operated while the electrode production line is in operation, the basis weight of the coating portion of the second layer material can be acquired without reducing the productivity of the electrode.

  According to the present invention, the basis weight of the coated portion of the second layer material can be obtained without being affected by the first layer.

The perspective view of an electrode. The schematic diagram which shows the production equipment and inspection apparatus which are used at a protective layer formation process. (A) is a schematic front view which shows the arrangement | positioning process in a protective layer formation process, (b) is a schematic side view which shows the coating process in a protective layer formation process, (c) is a schematic side view which shows the removal process in a protective layer formation process Figure.

Hereinafter, an embodiment in which an electrode inspection method is embodied in an electrode inspection method and an inspection apparatus for a secondary battery will be described with reference to FIGS. 1 to 3.
Although not shown, the secondary battery as a power storage device using the electrode inspected by the inspection method and inspection apparatus of this embodiment is a square battery having a rectangular external appearance, and is a lithium ion secondary battery. This secondary battery includes an electrode assembly in a case. The electrode assembly includes a plurality of positive electrodes and a plurality of negative electrodes. The electrode assembly is configured by alternately laminating positive electrodes and negative electrodes in a state where they are insulated by a separator.

  As shown in FIG. 1, an electrode 10 for a secondary battery includes a rectangular metal foil 11 as a current collector, an active material layer 12 as a first layer present on both surfaces of the metal foil 11, and an active material. And a protective layer 15 as a second layer present on the surface of the layer 12. The electrode 10 has an uncoated portion 13 along which the active material layer 12 is not present and the metal foil 11 is exposed. And in the electrode 10, the current collection tab 14 exists in the state in which a part of the uncoated part 13 protrudes. In the present embodiment, the electrode 10 is described as a negative electrode 10. The negative electrode 10 includes a protective layer 15 that covers the entire surface of the active material layer 12. The protective layer 15 includes alumina particles as ceramic particles and a resin binder, and has a layer structure in which alumina particles or alumina particles and active material particles on the surface of the active material layer 12 are bonded via the binder. . The heat-resistant temperature of the protective layer 15 mainly composed of alumina particles is higher than that of a resin separator.

  Next, a manufacturing process of the negative electrode 10 will be described. The manufacturing process of the negative electrode 10 includes an active material layer forming process in which the negative electrode active material layer 12 is formed on both surfaces of the long strip-shaped metal foil 11, and a protection layer 15 in which the protective layer 15 is formed on the surface of the active material layer 12. A layer forming step, and a punching step of punching the metal foil 11 on which the active material layer 12 and the protective layer 15 are formed into the shape of the electrode 10.

  Although not shown, the active material layer forming step includes a coating step, a drying step, and a pressing step. The application step is a step of applying an active material paste to one side of the long strip-shaped metal foil 11. However, the active material paste is not applied to the portion that will later become the uncoated portion 13. The metal foil 11 of this embodiment is, for example, a copper foil, and the active material paste is an active material paste for a negative electrode. The drying step is a step of drying the coated active material paste to form an active material layer precursor. The pressing step is a step of increasing the active material density of the active material layer precursor by passing the metal foil 11 on which the active material layer precursor is formed, through a roll press. Thereby, an active material layer 12 having a predetermined density and thickness is formed on one surface of the strip-shaped metal foil 11. Similarly, the active material layer 12 is formed on the other surface of the metal foil 11.

  As shown in FIG. 2, the protective layer forming process includes a coating process, a drying process, and an inspection process. In the coating process, the second layer material is formed on the surface of the active material layer 12 of the belt-like electrode 16 while conveying the long strip-shaped metal foil 11 (hereinafter referred to as the belt-like electrode 16) having the active material layer 12 formed on both sides. The ceramic slurry 17 as a coating is applied to form a coating portion 18 that becomes a precursor of the protective layer 15. Therefore, the coating part 18 is formed by the coating of the ceramic slurry 17. The drying process is a process of drying the coating part 18.

  The transport device 30 used in the protective layer forming step includes a supply roll 31, a take-up roll 32, and a plurality of guide rolls 33 arranged at a location between the supply roll 31 and the take-up roll 32. Each of the rolls 31 to 33 is rotatably supported by a support device (not shown). The strip electrode 16 is wound around the supply roll 31. The strip electrode 16 supplied from the supply roll 31 is conveyed by being wound around the winding roll 32.

  The coating apparatus that performs the coating process is a gravure coating apparatus 40. The gravure coating device 40 is disposed downstream of the supply roll 31 in the transport direction of the strip electrode 16. The gravure coating apparatus 40 includes a storage part 41 for the ceramic slurry 17, a cylindrical gravure roll 42, and a back roll 43 that faces the gravure roll 42 and the strip electrode 16. The ceramic slurry 17 stored in the storage unit 41 is obtained by kneading alumina particles and a binder such as PVDF (polyvinylidene fluoride) with water or a nonaqueous solvent such as NMP (N methylpyrrolidone).

  Although not shown, an oblique gravure pattern is engraved on the outer peripheral surface of the gravure roll 42. For this reason, the gravure roll 42 has a groove 42a extending obliquely with respect to the axial direction. Further, the gravure roll 42 is supported in a state where a part of the outer peripheral surface is always exposed in the storage portion 41.

  Such a gravure roll 42 is rotationally driven by a motor 44. As the gravure roll 42 rotates, the ceramic slurry 17 in the reservoir 41 adheres to the surface of the gravure pattern while entering the groove 42a of the gravure roll 42. The ceramic slurry 17 adhering to the surface of the gravure pattern is conveyed from the storage portion 41 toward the strip electrode 16 by the rotation of the gravure roll 42. At the coating position P, the conveyed ceramic slurry 17 contacts the surface of the active material layer 12 of the strip electrode 16 supplied from the supply roll 31. As a result, the ceramic slurry 17 is applied to the surface of the active material layer 12 to form a coating portion 18.

  The strip electrode 16 on which the coating unit 18 is formed is guided by the guide roll 33 and is transported into the drying device 50 disposed downstream of the gravure roll 42 in the transport direction. The coating unit 18 is dried by the drying device 50. The belt-like electrode 16 is guided by the guide roll 33 and then taken up by the take-up roll 32.

Next, the inspection process will be described.
An inspection process is a process of inspecting the formation state of coating part 18 which becomes protective layer 15 later using measurement sheet 19 mentioned below. The inspection process is performed while the coating process and the drying process are performed. For example, the inspection process is performed every time the belt-like electrode 16 is conveyed 100 m. The inspection process is performed using an inspection apparatus.

  As shown in FIGS. 2 and 3A, the inspection process includes an arrangement process of arranging the measurement sheet 19 with respect to the belt-like electrode 16 being conveyed. The placement process is performed by a sticking device 60 (not shown in FIG. 3A) as a placement device of the inspection device. In the arranging step, the rectangular measurement sheet 19 is attached to a part of the surface of the strip electrode 16 supplied from the supply roll 31 and before the ceramic slurry 17 is applied by using the attaching device 60. The measurement sheet 19 is the same copper foil as the copper foil used for the metal foil 11. In the present embodiment, the lateral direction of the measurement sheet 19 coincides with the conveyance direction of the strip electrode 16, and the longitudinal direction of the measurement sheet 19 is a direction perpendicular to the conveyance direction and the thickness direction in the strip electrode 16. To match. The dimension in the short direction of the measurement sheet 19 is, for example, about 50 cm, and the dimension in the longitudinal direction is larger than the dimension in the width direction of the strip electrode 16. Therefore, the measurement sheet 19 attached to the strip electrode 16 has portions 19 a that protrude in the width direction from the strip electrode 16 at both ends in the longitudinal direction. Further, water as an adhering means is preliminarily applied to the surface of the measurement sheet 19 to be attached to the strip electrode 16 by the attaching device 60. Thereby, the metal foil 11 and a part of the active material layer 12 are covered with the measurement sheet 19 in the transport direction of the strip electrode 16.

  Then, as shown in FIG.3 (b), the ceramic slurry 17 is apply | coated to the strip | belt-shaped electrode 16 with which the sheet | seat 19 for measurement was affixed, and the coating part 18 is formed (coating process). The coating portion 18 is formed on the surface of the active material layer 12 of the strip electrode 16 and the surface of the measurement sheet 19. Of the coating part 18, the part formed on the surface of the active material layer 12 is referred to as a first coating part 18a, and the part formed on the surface of the measurement sheet 19 is referred to as a second coating part 18b. In the coating process, by setting the rotational speed of the gravure roll 42 to a constant value, the first coating part 18a and the second coating part 18b have the same basis weight.

  The belt-like electrode 16 on which the coating part 18 is formed is guided by the guide roll 33 and is conveyed into the drying device 50. The first coating part 18a and the second coating part 18b are dried (drying process). In addition, the water as the adhesion means applied to the measurement sheet 19 evaporates in this drying step.

  As shown in FIGS. 2 and 3C, the inspection process includes a removal process of removing the measurement sheet 19 and the dried second coating portion 18b from the belt-like electrode 16 being conveyed. The removing process is performed by a removing device 70 (not shown in FIG. 3C) of the inspection device. In the removal step, the second coating portion 18b formed on the measurement sheet 19 is also collected by removing the measurement sheet 19 from the strip electrode 16 on which the coating portion 18 is formed using the removal device 70. Removed. The removing device 70 removes the measurement sheet 19 from the strip electrode 16 by grasping a portion 19 a protruding from the strip electrode 16 in the measurement sheet 19. The strip electrode 16 from which the measurement sheet 19 has been removed is taken up by a take-up roll 32 through a guide roll 33. However, the portion of the strip electrode 16 where the measurement sheet 19 is attached is not made into a product.

  The inspection step includes a measurement step of measuring the weight A of the removed measurement sheet 19 and the second coating portion 18b and the area D of the second coating portion 18b. The measurement process is performed by the measurement unit 81 included in the measurement device 80 of the inspection apparatus. The inspection process includes a calculation process for calculating the basis weight of the coating part 18 from the weight A and the area D measured in the measurement process. The calculation process is performed by a calculation unit 82 included in the measurement device 80 of the inspection apparatus. The calculation unit 82 subtracts the known weight B of the measurement sheet 19 from the weight A measured by the measurement unit 81 to obtain the weight C of only the second coating unit 18b. The calculation unit 82 divides the weight C of the obtained second coating part 18b by the area D of the second coating part 18b to obtain the basis weight of the second coating part 18b. As described above, since the first coating portion 18a and the second coating portion 18b are coated so as to have the same basis weight, the basis weight of the second coating portion 18b is set to the first coating portion 18a. It is good as a basis weight.

  In the inspection process, the quality of the formation state of the first coating part 18a is determined based on the basis weight of the coating part 18 (the first coating part 18a and the second coating part 18b) calculated by the calculation part 82. A determination step is included. The determination process is performed by the determination device 91 of the inspection apparatus. The determination device 91 is signal-connected to the measurement device 80, and the basis weight calculated by the calculation unit 82 is output to the determination device 91. The determination device 91 determines whether or not the input weight per unit area of the coating unit 18 is within the target weight per unit area. When the basis weight of the coating unit 18 is within the target basis weight range, the determination device 91 determines that the formation state of the first coating unit 18a is good. When the basis weight of the coating unit 18 exceeds the target upper limit value of the basis weight, the determination device 91 determines the formation state of the first coating unit 18a as defective 1. When the basis weight of the coating part 18 falls below the lower limit value, the determination device 91 determines that the formation state of the first coating part 18a is defective 2.

  When the determination device 91 determines the formation state of the first coating portion 18a as defect 1 or defect 2, it corresponds to the determination of defect 1 or defect 2 to the control device 92 connected to the gravure coating device 40. Output a signal. When a signal corresponding to the determination of defect 1 is input, the control device 92 accelerates the rotational drive of the motor 44 to accelerate the rotational speed of the gravure roll 42 and reduces the basis weight of the coating unit 18. On the other hand, when the signal corresponding to the determination of the defect 2 is input, the control device 92 reduces the rotational speed of the gravure roll 42 by reducing the rotational drive of the motor 44 and increases the basis weight of the coating unit 18. .

  Although not shown, the strip electrode 16 on which the coating portion 18 is formed is punched into the shape of the electrode 10 in a punching process. The protective layer 15 is formed from the 1st coating part 18a. In this way, the sheet-like negative electrode 10 is manufactured.

Next, the operation of this embodiment will be described.
The basis weight of the coating part 18 that will later become the protective layer 15 is calculated from the weight A of the measurement sheet 19 and the second coating part 18b.

Next, characteristic effects of the present embodiment will be described.
(1) The basis weight of the coating part 18 that will later become the protective layer 15 is calculated from the weight A of the measurement sheet 19 and the second coating part 18b. Unlike the case where the weight per unit area of the coating part 18 is acquired from the whole including the metal foil 11, the active material layer 12, and the coating part 18, it is not affected by the active material layer 12. Therefore, even if there is a variation in the basis weight of the active material layer 12 in the active material layer forming step, the basis weight of the coating portion 18 can be obtained accurately without being affected. Moreover, since the arrangement | positioning process and removal process of the measurement sheet | seat 19 are performed, conveying the strip | belt-shaped electrode 16, the fabric weight of the coating part 18 can be acquired, without reducing the productivity of the electrode 10. FIG.

  (2) Since the measurement sheet 19 is affixed to the strip electrode 16 with water in the placement step by the sticking device 60, the displacement of the measurement sheet 19 with respect to the strip electrode 16 is suppressed.

  (3) Since the removal process is performed after the drying process and water is used as the bonding means, the water evaporates in the drying process. Therefore, it is not necessary to consider the weight of water in the calculation process.

  (4) The determination device 91 determines the quality of the formation state of the first coating part 18a based on the basis weight of the coating part 18, and controls the determination result (defect 1 or defect 2) if determined to be defective. The signal is output to the device 92. The control device 92 changes the rotation speed of the gravure roll 42 of the gravure coating device 40 based on the signal input from the determination device 91 to increase or decrease the basis weight of the coating unit 18. That is, the quality of the formation state of the first coating part 18 a determined by the determination device 91 is fed back to the coating process of the ceramic slurry 17. For this reason, it is possible to form the coating portion 18 having an appropriate basis weight.

  (5) Since the measurement sheet 19 has a dimension in the longitudinal direction larger than the dimension in the width direction of the strip electrode 16, the measurement sheet 19 has portions 19 a that protrude from the strip electrode 16 on both sides in the width direction. In the process of removing the measurement sheet 19 by the removal device 70, the measurement sheet 19 can be easily removed by gripping the portion 19 a protruding from the strip electrode 16 by the removal device 70.

(6) Since the same copper foil is used for the measurement sheet 19 and the metal foil 11, it is not necessary to prepare a material for the measurement sheet 19 separately.
(7) In coating using the gravure coating apparatus 40, the basis weight of the coating unit 18 depends on the rotation speed of the gravure roll 42. For this reason, if the coating process is performed in a state where the rotation speed of the gravure roll 42 is constant, the active material layer of the strip electrode 16 can be obtained even if the thickness of the strip electrode 16 varies due to the measurement sheet 19 being arranged 12 and the second coating portion 18b formed on the measurement sheet 19 can have the same basis weight. Moreover, when changing the fabric weight of the coating part 18, it is only necessary to change the rotational speed of the gravure roll 42, and a complicated adjustment operation is not required.

In addition, you may change the said embodiment as follows.
In the above embodiment, the case where the electrode 10 is a negative electrode has been described. However, in the case of a positive electrode, the basis weight of the coating portion 18 can be inspected by the same inspection method. However, for example, an aluminum foil is used for the metal foil 11 of the positive electrode 10, and an active material paste for the positive electrode is used for the active material paste.

  The electrode 10 may have the active material layer 12 and the protective layer 15 only on one side of the metal foil 11. In this case, the active material layer 12 is provided only on one surface of the belt-like electrode 16, and the coating portion 18 of the ceramic slurry 17 is formed on the active material layer 12.

The current collector is not limited to the metal foil 11 as long as the active material layer 12 can be formed. For example, a woven or net-like sheet may be used.
The second layer is not limited to the protective layer 15. For example, an active material layer having a different structure from the water repellent layer and the active material layer 12 as the first layer may be used.

The ceramic particles included in the protective layer 15 are not limited to alumina particles. For example, other metal oxides or metal nitrides may be used.
O Adhesive means is not limited to water as long as it volatilizes or evaporates in the drying process. For example, ethanol, NMP, or the like may be used. However, when NMP is used as the solvent of the active material paste, it is not preferable to use NMP as the bonding means.

  ○ For the measurement sheet 19 of the above embodiment, the same copper foil as the copper foil used for the metal foil 11 was used, as long as the corrosion resistance, the wettability of the ceramic slurry 17 and the heat resistance in the drying process are satisfied. Other sheet-like materials (for example, aluminum foil) may be used.

The shape of the measurement sheet 19 is not limited to a rectangular shape. For example, a circle or a polygon may be used.
The dimension in the width direction of the measurement sheet 19 may be smaller than the dimension in the width direction of the strip electrode 16.

O Although the dimension in the conveyance direction of the measurement sheet 19 was about 50 cm, the numerical value may be changed as appropriate.
In the above embodiment, the measurement sheet 19 is disposed so as to cover a part of the metal foil 11 and the active material layer 12 of the strip electrode 16, but it may be a part where the ceramic slurry 17 is applied in the coating process. For example, the measurement sheet 19 may be arranged so as to cover only a part of the metal foil 11 of the strip electrode 16 or only a part of the active material layer 12.

  For example, the ceramic slurry 17 is applied so that the width of the coating portion 18 is larger than the width of the active material layer 12 in the width direction of the strip electrode 16. In this case, in the metal foil 11, the active material layer 12 may not be formed, and the measurement sheet 19 may be disposed on a part of the portion where the ceramic slurry 17 is applied in the coating process.

  The active material paste coating step in the active material layer forming step may be continuous coating performed continuously in the conveying direction of the metal foil 11 or intermittent coating applied at intervals. In the case of intermittent coating, the coating process of the ceramic slurry 17 in the protective layer forming process is an intermittent coating in which the rotation of the gravure roll 42 is intermittently stopped and the strip electrode 16 is applied at intervals in the transport direction. To do.

In the above embodiment, the formation state of the coating portion 18 is inspected every time the belt-like electrode 16 is transported 100 m. However, the inspection frequency may be changed as appropriate.
In the above embodiment, the placement step and the removal step are performed using the sticking device 60 and the removal device 70, but may be performed manually by an operator. Moreover, in the said embodiment, although the measuring process and the determination process were performed using the measuring apparatus 80 and the determination apparatus 91, you may perform manually by an operator.

  (Circle) the coating method in a coating process is not limited to the gravure coating using the gravure coating apparatus 40. FIG. Other coating methods (for example, spray coating) in which the first coating portion 18a and the second coating portion 18b have the same basis weight may be used. Moreover, even if it is the coating method in which the 1st coating part 18a and the 2nd coating part 18b do not become the same basis weight, the basis weight of the 1st coating part 18a and the basis weight of the 2nd coating part 18b It is sufficient to clarify the relationship in advance.

  In the above embodiment, the measurement sheet 19 and the second coating part 18b are removed from the strip electrode 16 after the drying process, but even if the measurement sheet 19 and the second coating part 18b are removed before the drying process. Good. However, in the calculation process, it is necessary to calculate the basis weight of the coating part 18 in consideration of the volatilization amount of the coating part 18 and the weight of the bonding means.

  In the manufacturing process of the electrode 10 of the above embodiment, a determination process for determining the quality of the formation state of the coating part 18 based on the calculated basis weight of the coating part 18 is provided. Also good.

  ○ In the above embodiment, the pass / fail judgment of the formation state of the coating part 18 is used by feeding back to the coating process, but it is used for selecting non-defective / defective products of the electrode 10 on which the protective layer 15 is formed. May be.

In the above embodiment, the active material layer forming step, the protective layer forming step, and the punching step are performed in separate production lines, but may be performed continuously in the same production line.
In the above embodiment, the measurement unit 81 and the calculation unit 82 are integrated as the measurement device 80, but may be separate from each other.

(Circle) You may apply to the inspection method of the electrode for not only the electrode inspection method for laminated | stacked electrode assemblies but the winding type electrode assembly.
(Circle) the inspection method of the electrode 10 in the said embodiment may be applied to the inspection method of the electrode used for electrical storage apparatuses, such as an electrode used for a nickel hydride secondary battery, and an electrical double layer capacitor, for example.

Next, a technical idea that can be grasped from the above embodiment and another example will be added below.
(A) The current collector and the measurement sheet are copper foils.

  DESCRIPTION OF SYMBOLS 10 ... Electrode, 11 ... Metal foil as a collector, 12 ... Active material layer as 1st layer, 15 ... Protective layer as 2nd layer, 16 ... Strip electrode, 17 ... Ceramic slurry as 2nd layer material , 18a ... 1st coating part as a coating part, 18b ... 2nd coating part as a coating part, 19 ... Sheet for measurement, 19a ... Projecting part, 40 ... Gravure coating apparatus, 60 ... As arrangement apparatus Sticking device, 70 ... removal device, 80 ... measuring device, 81 ... measuring unit, 82 ... calculating unit.

Claims (9)

An inspection method for an electrode having a current collector, a first layer present on both or one side of the current collector, and a second layer present on the surface of the first layer,
An arrangement step of arranging a measurement sheet on a part of a portion where the second layer material is applied later, with respect to the band-like electrode on which the first layer is formed on both surfaces or one surface of the current collector;
After the arrangement step, a coating step of coating the second layer material on the surface of the first layer and the surface of the measurement sheet to form a coating portion that is a precursor of the second layer;
A removal step of removing the measurement sheet on which the coating portion is formed from the strip electrode;
A measurement step of measuring the weight of the coating sheet formed on the measurement sheet and the measurement sheet removed in the removal step;
A calculation step of calculating the basis weight of the coated part from the weight measured in the measurement step;
A method for inspecting an electrode, comprising:   2. The electrode inspection method according to claim 1, wherein in the arranging step, the measurement sheet is attached to the strip electrode by an adhesive unit.   The electrode inspection method according to claim 2, further comprising a drying step of drying the coated portion before the removing step.   The electrode according to any one of claims 1 to 3, further comprising a determination step of determining pass / fail of the formation state of the coated portion based on the basis weight of the coated portion calculated in the calculating step. Inspection method.   5. The electrode inspection method according to claim 1, wherein, in the arrangement step, the measurement sheet is arranged so as to have a portion protruding from the belt-like electrode.   The electrode according to any one of claims 1 to 5, wherein the first layer is an active material layer, and the second layer is a protective layer made of a ceramic material as the second layer material. Inspection method.   The electrode inspection method according to claim 1, wherein the measurement sheet is made of the same material as the current collector.   The electrode inspection method according to any one of claims 1 to 7, wherein a gravure coating apparatus is used in the coating step. An electrode inspection apparatus for inspecting an electrode having a current collector, a first layer present on both or one side of the current collector, and a second layer present on the surface of the first layer,
An arrangement device that arranges a measurement sheet on a part of a portion to which the second layer material is applied later, with respect to the band-like electrode on which the first layer is formed on both sides or one side of the current collector;
After the second layer material is applied to the surface of the first layer and the surface of the measurement sheet disposed on the belt-like electrode, and the coating part that is the precursor of the second layer is formed, A removal device for removing the measurement sheet on which the coating portion is formed from the strip electrode;
A measurement unit that measures the weight of the measurement sheet that has been removed, and a weight of the coating part that is formed on the measurement sheet, and a calculation unit that calculates the basis weight of the coating part from the weight measured by the measurement unit; A measuring device with
An electrode inspection apparatus comprising:

Images