JP2012127782A - Coating device, coating method, and method of manufacturing battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating device and a coating method in which the coating status of layers formed on the base material side in two-layer coating can be inspected, and also to provide a method of manufacturing a battery.SOLUTION: In a coating device 1 in which a binder liquid 32 and a negative electrode paste 36 are discharged from a die 10 to a copper foil 30 to be conveyed, and overlapped on a binder layer 34 to form a negative electrode paste layer 38, an inspection mechanism 12 to inspect the binder layer 34 is provided inside a partition part 18 for forming a first discharge port 22 from which the binder liquid 32 in the die 10 is discharged.

Description

  The present invention relates to a coating apparatus, a coating method, and a battery manufacturing method for coating and forming an active material paste used in, for example, a lithium ion battery on a current collector.

  Patent Document 1 discloses a method for manufacturing an electrode in which a conductive layer is formed in a lower layer and an active material layer is formed in an upper layer on a base material. In the electrode manufacturing method of Patent Document 1, the conductive liquid and the active material liquid are discharged to the base material by a die having two discharge ports to form a conductive layer and an active material layer.

JP 2001-345096 A

  Here, the quality inspection of each coating layer in a multilayer coating product such as an adhesive tape is generally performed by transmitting radiation or infrared rays through each coating layer. However, when manufacturing an electrode by performing two-layer coating that forms two layers of a conductive layer and an active material layer on a substrate as shown in Patent Document 1, the upper active material layer is not permeable, It is difficult to inspect the application state of the lower conductive layer covered with the upper active material layer.

  Also, in the case of manufacturing an electrode by applying a binder as a binder to the lower layer of the current collector and applying an active material as the upper layer, the permeability of the active material and the copper night is low, It becomes difficult to inspect the application state of the lower binder with the camera. Further, since radiation is confused and blocked by the active material and copper stay (metal), it is difficult to inspect the coating state of the lower binder by the radiation. In addition, since the material of the die is a metal with a large atomic number such as stainless steel, for example, even if a radiation inspection device is provided around the discharge port of the die, the radiation irradiated from the radiation inspection device is confused or blocked. Therefore, it is difficult to inspect the coating state of the lower layer binder.

  Then, this invention was made | formed in order to solve the above-mentioned problem, The coating apparatus which can test | inspect the application state of the layer formed in the base material side in 2 layer coating, the coating method, It is an object to provide a method for manufacturing a battery.

  One aspect of the present invention made to solve the above-described problems is that the first liquid and the second liquid are discharged from the die to the substrate to be conveyed, and the first layer is formed on the first layer formed by the first liquid. In a coating apparatus for forming a second layer formed by the second liquid, an inspection unit for inspecting the first layer inside a member forming a first discharge port for discharging the first liquid in the die. Is provided.

  According to this aspect, the application state of the first layer formed on the base material side without being influenced by the second layer by the inspection means provided inside the member forming the first liquid discharge port in the die is determined. Can be inspected.

  In the said aspect, the said die | dye is comprised in order of the upstream part, the partition part, and the downstream part with respect to the conveyance direction of the said base material, and the member which forms the said 1st discharge port is comprised by the said upstream part and the said partition part. In addition, it is preferable that the inspection means is provided inside the partition.

  According to this aspect, it is possible to inspect the application state of the first layer before the second layer is formed by being overlapped by the inspection means through the intermediate partition portion. Therefore, the coating state of the first layer can be inspected more reliably without being affected by the second layer.

  In the above aspect, the inspection means is an image inspection camera device, and the member forming the first discharge port is formed of a material capable of capturing an image of the first layer by the image inspection camera device. It is preferable to provide the part which has.

  According to this aspect, the image of the first layer can be directly captured by the image inspection camera device, and the application state of the first layer can be inspected based on the captured image.

  In the above aspect, the inspection means is a radiation inspection apparatus, and the member forming the first discharge port is a portion formed of a material that can inspect the formation state of the first layer by the radiation inspection apparatus. It is preferable to provide.

  According to this aspect, radiation data on the first layer can be directly acquired by the radiation inspection apparatus, and the application state of the first layer can be inspected based on the acquired radiation data.

  Another aspect of the present invention made in order to solve the above-described problem is that the first liquid and the second liquid are discharged from the die to the substrate to be conveyed, and the first layer is formed on the first layer formed by the first liquid. In the coating method for forming the second layer formed by the second liquid, the first layer is inspected from the inside of the member forming the first discharge port for discharging the first liquid in the die. It is characterized by.

  Another aspect of the present invention made to solve the above-described problem is that the binder liquid and the active material liquid are discharged from the die to the conveyed current collector, and the layer is formed on the binder layer formed by the binder liquid. In a method of manufacturing a battery having an electrode in which an active material layer formed by an active material liquid is formed, while inspecting the binder layer from the inside of a member forming a first discharge port for discharging the binder liquid in the die. The electrode is formed.

  According to the coating apparatus, the coating method, and the battery manufacturing method according to the present invention, it is possible to inspect the coating state of the layer formed on the substrate side in the two-layer coating.

It is a figure which shows the schematic structure of a coating device, and the discharge port periphery. It is a flowchart figure explaining the feedback control with respect to die coating performed based on the inspection information of the binder layer inspected by the image inspection camera. It is a flowchart figure explaining the feedback control with respect to die coating performed based on the inspection information of the binder layer inspected with the radiation inspection machine.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[Description of coating equipment]
As shown in FIG. 1, the coating apparatus 1 of this embodiment includes a die 10, an inspection mechanism 12, a control unit 14, and the like. The die 10 includes an upstream portion 16, an intermediate partition portion 18, and a downstream portion 20, and is configured in the order of the upstream portion 16, the intermediate partition portion 18, and the downstream portion 20 in the conveyance direction of the copper stay 30 described later. The die 10 includes a first discharge port 22 formed between the upstream portion 16 and the intermediate partition portion 18 and a second discharge port 24 formed between the intermediate partition portion 18 and the downstream portion 20. With two outlets. The material of the upstream part 16 and the downstream part 20 is a metal such as SUS304, for example. As will be described later, the material of the middle partition portion 18 is a material having a light transmittance of 80% or a low atomic number material.

  The inspection mechanism 12 includes a detection unit 26 and an inspection main body unit 28. The detection unit 26 is provided inside the partition part 18 of the die 10, and the inspection mechanism 12 inspects the application state of the binder layer 34 through the partition part 18 as will be described later. The details of the partition portion 18 of the die 10 and the inspection mechanism 12 will be described later.

  The control unit 14 is means for controlling the gap G of the die 10 based on the inspection information in the inspection mechanism 12 and controlling the pump (not shown) driving the binder liquid 32 to the die 10.

  The coating apparatus 1 according to the present embodiment having such a configuration discharges the binder liquid 32 as the binder from the first discharge port 22 to the copper stay 30 of the current collector to be conveyed, thereby binding the binder layer. 34 is further formed, and the negative electrode paste 36 containing the electrode active material is discharged from the second discharge port 24 and applied over the binder layer 34 to form the negative electrode paste layer 38. Thereby, an electrode in which two layers of the binder layer 34 and the negative electrode paste layer 38 are formed with respect to the copper stay 30 can be manufactured, and a battery can be manufactured using the electrode thus manufactured.

  The copper stay 30 is an example of the “base material” in the present invention, the binder liquid 32 is an example of the “first liquid” in the present invention, and the negative electrode paste 36 is an example of the “second liquid” in the present invention. is there. The binder layer 34 is an example of the “first layer” in the present invention, and the negative electrode paste layer 38 is an example of the “second layer” in the present invention.

[Description of inspection mechanism and partition]
Next, details of the inspection mechanism 12 and the partition 18 of the die 10 will be described. Example 1 and Example 2 can be considered for the partitioning portion 18 of the inspection mechanism 12 and the die 10 as follows.

<Example 1>
In Example 1, the partition part 18 of the die 10 is formed of a member made of a material (acrylic resin or the like) having a light transmittance of 80%. Then, an image inspection camera device is employed as the inspection mechanism 12, and an imaging unit of the image inspection camera device is provided as the detection unit 26 inside the partition 18. In addition, the main body of the image inspection camera device is connected to the imaging unit as the inspection main body 28. The imaging unit of the image inspection camera device may be a camera generally used in image inspection, and a CCD camera, a high-sensitivity camera, or the like can be considered.

  In this embodiment, since the partition part 18 of the die 10 is formed of a material made of a material having a light transmittance of 80%, the image pickup part (detection part 26) of the image inspection camera device passes through the partition part 18. Thus, the lower binder layer 34 can be directly imaged. Therefore, even if the upper negative electrode paste layer 38 does not have transparency, the quality inspection of the lower binder layer 34 can be performed by the image inspection camera device. The contents of the quality inspection of the binder layer 34 by the image inspection camera device include coating scales in a predetermined region of the binder layer 34 (coating defect such that the copper stay 30 (base material) can be seen) and coating unevenness (coating). The presence / absence of unevenness in the amount may be considered.

  Here, the quality inspection of the binder layer 34 was actually performed using an image inspection camera device. The inspection conditions for the die 10 are SUS304 for the material of the upstream portion 16 and the downstream portion 20 and acrylic resin (light transmittance is about 93%, and the constituent elements are C, H, and O). . A high-sensitivity camera was used as the image inspection camera device, and a telecentric lens and halogen illumination were further used. Then, a binder liquid 32 made of SBR (styrene / butadiene rubber) is applied to form a binder layer 34 in the lower layer, and a negative electrode paste 36 containing a carbon material and a thickener is applied to form a negative electrode paste layer 38 in the upper layer. Under such conditions, the binder layer 34 was inspected. As a result, the imaging unit of the image inspection camera device can directly image the binder layer 34 through the partitioning part 18, and can detect coating scale and coating unevenness in the binder layer 34.

  Then, based on the inspection information such as coating scale and coating unevenness in the binder layer 34 detected in this way, the control unit 14 performs feedback control on the coating of the die 10 as shown in FIG. Can do. FIG. 2 is a flowchart for explaining feedback control for the coating of the die 10 performed based on the inspection information.

  First, an image of the binder layer 34 is captured and captured by the imaging unit (detection unit 26) of the image inspection camera device provided inside the partition portion 18 of the die 10 (step S1). Next, based on the captured image of the binder layer 34, image data is generated by performing operations such as image processing in the main body (inspection main body 28) of the image inspection camera device (step S2). Next, the created image data is compared with a plurality of pre-created application scales and application uneven pattern information (suke / uneven patterns) (step S3).

  Then, it is determined whether or not there is any coating scale or coating unevenness in the binder layer 34 (step S4). When it is determined that there is coating scale or uneven coating in the binder layer 34, an appropriate gap G (see FIG. 1) of the die 10 for preventing the coating layer or uneven coating from existing in the binder layer 34 is set. Calculate (step S5). Then, for example, the balance of the gap G in the left and right direction (longitudinal direction, vertical direction in FIG. 1) in the die 10 is adjusted by the gap adjusting means (not shown) so as to obtain the calculated appropriate gap G (step S6). On the other hand, if it is determined in step S4 that there is no coating scale or unevenness in the binder layer 34 in the image data, the gap G of the die 10 is maintained as it is (step S7). As described above, feedback control can be performed on the coating of the die 10 based on inspection information such as coating scale and coating unevenness in the binder layer 34.

  According to the present embodiment, the imaging unit (detection unit) of the image inspection camera device (inspection mechanism 12) provided inside the partition 18 that forms the first discharge port 22 through which the binder liquid 32 in the die 10 is discharged. 26), the application state of the binder layer 34 can be directly inspected through the intermediate partition portion 18 without being affected by the negative electrode paste layer 38.

  Further, since feedback control is performed on the coating of the die 10 by the control unit 14 based on the inspection information of the coating state of the binder layer 34 by the image inspection camera device, the lack of coating and the coating unevenness are applied to the copper stay 30. The binder layer 34 can be stably applied while being suppressed. Therefore, the yield can be improved in the manufacture of the electrodes.

<Example 2>
In the second embodiment, the partition 18 of the die 10 is a member made of a low atomic number material. As the low atomic number material, a resin composed of H, C, O or the like, for example, acrylic or the like can be considered. A radiation inspection apparatus is employed as the inspection mechanism 12, and a radiation detection unit of the radiation inspection apparatus that detects radiation data by irradiating the object to be inspected with radiation as a detection unit 26 is provided inside the partition 18. In addition, the main body of the radiation inspection apparatus is connected to the radiation detection unit as the inspection main body 28.

  Thus, the partition part 18 of the die 10 is a member made of a low atomic number material. Therefore, it is possible to inspect the lower binder layer 34 through the intermediate partition 18 by the radiation detection unit without the radiation radiated from the radiation detection unit (detection unit 26) of the radiation inspection apparatus being confused or blocked. it can. Therefore, even if the upper negative electrode paste layer 38 does not have transparency, the quality inspection of the lower binder layer 34 can be performed by the radiation inspection apparatus. The content of the quality inspection of the binder layer 34 by the radiation inspection apparatus may be the thickness of the binder layer 34 (amount of the binder liquid 32 applied).

In selecting the low atomic number material in the partition 18 of the die 10, a low atom such that the following formula is established for the mass attenuation coefficient μm, which is the attenuation amount of the radiation irradiated from the radiation detection unit of the radiation inspection apparatus. Select the number material.

Further, the mean free path λ as the radiation transmission distance is expressed by the following equation.

  Then, based on the mathematical formula of the formula 2, the condition of the mean free process λ that satisfies the condition expressed by the formula 1 is obtained, and the low atomic number material that satisfies the condition of the obtained mean free process λ is selected. May be. In this embodiment, the density ρ of the substance in the mathematical formula 2 corresponds to, for example, the density of the binder layer and the density of the copper stay.

  Then, based on the detected coating amount inspection information in the binder layer 34, the control unit 14 can perform feedback control on the coating of the die 10 as shown in FIG. FIG. 3 is a flowchart for explaining feedback control for coating the die 10 performed based on the inspection information.

  First, the radiation data detected by the binder layer 34 is taken in by the radiation detection part (detection part 26) of the radiation inspection apparatus provided inside the partition part 18 of the die 10 (step S11). Next, based on the acquired radiation data, a calculation process is performed in the main body (inspection main body 28) of the radiation inspection apparatus, and the amount of radiation transmitted through the binder layer 34 is calculated (step S12). Next, based on the calculated amount of radiation transmitted through the binder layer 34, the thickness of the binder layer 34 is calculated from a correlation graph (calibration curve) between the amount of radiation transmitted through the binder layer 34 and the thickness of the binder layer 34 prepared in advance. Is calculated (step S13).

  In step S12, the amount of reflection is calculated instead of the amount of radiation transmitted through the binder layer 34. From the correlation graph between the amount of radiation reflected in the binder layer 34 and the thickness of the binder layer 34 prepared in advance in step S13, the binder layer is calculated. A thickness of 34 may be calculated.

  Next, it is determined whether or not the calculated thickness of the binder layer 34 is a target thickness (step S14). When it is determined that the calculated thickness of the binder layer 34 is not the target thickness, a pump (not shown) that supplies the binder liquid 32 so that the thickness of the binder layer 34 becomes the target thickness. The rotational speed is controlled (step S15). On the other hand, when it is determined that the thickness of the binder layer 34 calculated in step S14 is the target thickness, control is performed so that the rotational speed of the pump that supplies the binder liquid 32 is maintained as it is. As described above, feedback control can be performed on the coating of the die 10 based on the inspection information of the coating amount in the binder layer 34.

  According to the present embodiment, the radiation detection unit (detection unit) of the radiation inspection apparatus (inspection mechanism 12) provided in the inner partition 18 that forms the first discharge port 22 through which the binder liquid 32 in the die 10 is discharged. 26), the application state of the binder layer 34 can be directly inspected through the intermediate partition portion 18 without being affected by the negative electrode paste layer 38.

  Further, since the control unit 14 performs feedback control on the coating of the die 10 based on the inspection information on the coating state of the binder layer 34 by the radiation inspection apparatus, the amount of the binder liquid 32 applied to the copper stay 30 The binder layer 34 can be stably applied while adjusting. Therefore, the yield can be improved in the manufacture of the electrodes.

[Other Examples]
Moreover, you may provide both the imaging part of an image inspection camera apparatus, and the radiation detection part of a radiation inspection apparatus as the detection part 26 of the test | inspection mechanism 12 in the inside of the partition part 18 of die | dye 10. FIG. As a result, it is possible to perform both inspection of coating scale and coating unevenness in the binder layer 34 and inspection of the thickness of the binder layer 34.

  Moreover, the partition part 18 of the die 10 is not limited to being formed of a member made of a material having a light transmittance of 80% or a low atomic number material. The partition part 18 of the die 10 is, for example, a member made of a material having a light transmittance of 80% or a material having a low atomic number only on the copper stay 30 side from the position where the detection part 26 of the inspection mechanism 12 is provided. The other portions may be formed of a metal such as SUS304.

  Further, the detection unit 26 of the inspection mechanism 12 is not limited to being provided inside the partition part 18 of the die 10, and may be provided inside the upstream part 16 of the die 10. At this time, the upstream portion 16 of the die 10 is formed of a member made of a material having a light transmittance of 80% or more, and the imaging portion of the image inspection camera device serves as the detection portion 26 of the inspection mechanism 12 inside the upstream portion 16 of the die 10. A part may be provided. Further, the upstream portion 16 of the die 10 may be formed of a member made of a low atomic number material, and the radiation detection portion of the radiation inspection apparatus may be provided as the detection portion 26 of the inspection mechanism 12 inside the upstream portion 16 of the die 10. .

  It should be noted that the above-described embodiment is merely an example and does not limit the present invention in any way, and various improvements and modifications can be made without departing from the scope of the invention.

DESCRIPTION OF SYMBOLS 1 Coating apparatus 10 Die 12 Inspection mechanism 14 Control part 16 Upstream part 18 Middle part 20 Downstream part 22 1st discharge port 24 2nd discharge port 26 Detection part 28 Inspection body part 30 Copper stay 32 Binder liquid 34 Binder layer 36 Negative electrode Paste 38 Negative electrode paste layer

Claims (6)

Coating that discharges the first liquid and the second liquid from the die to the substrate to be conveyed and forms the second layer formed by the second liquid on the first layer formed by the first liquid. In the device
Inspection means for inspecting the first layer is provided inside a member forming a first outlet from which the first liquid is discharged in the die;
A coating device characterized by In the coating apparatus of Claim 1,
The die is configured in the order of the upstream part, the intermediate partition part and the downstream part in the transport direction of the base material,
The member forming the first discharge port is constituted by the upstream part and the partition part,
The inspection means is provided inside the partition;
A coating device characterized by The coating apparatus according to claim 1 or 2,
The inspection means is an image inspection camera device,
The member forming the first discharge port includes a portion formed of a material capable of capturing an image of the first layer by the image inspection camera device;
A coating device characterized by The coating apparatus according to claim 1 or 2,
The inspection means is a radiation inspection apparatus,
The member forming the first discharge port includes a portion formed of a material capable of inspecting a formation state of the first layer by the radiation inspection apparatus;
A coating device characterized by Coating that discharges the first liquid and the second liquid from the die to the substrate to be conveyed and forms the second layer formed by the second liquid on the first layer formed by the first liquid. In the method
Inspecting the first layer from within a member forming a first outlet through which the first liquid in the die is discharged;
A coating method characterized by A battery having an electrode in which a binder liquid and an active material liquid are discharged from a die to a conveyed current collector, and an active material layer formed by the active material liquid is formed on a binder layer formed by the binder liquid. In the manufacturing method of
Creating the electrode while inspecting the binder layer from the inside of the member forming the first outlet through which the binder liquid in the die is discharged;
A battery manufacturing method characterized by the above.

Images