Coating device, circulating device, and conveying device

Abstract

An impurity detection support device 100 is equipped with: a pipe 102 through which a test fluid flows; a first electrode and a second electrode which are positioned inside the pipe 102 and are positioned so as to be capable of applying an AC voltage to or superimposing an alternating current onto the test fluid in a space extending between a first position and a second position which are offset from one another in the direction in which the pipe 102 extends; a power supply unit 106 for applying the AC voltage or superimposing the alternating current between the pair of electrodes; a measurement unit 108 for measuring the current produced between the pair of electrodes by application of the AC voltage or measuring the voltage produced between the pair of electrodes by superimposition of the alternating current; and a calculation unit 110 for calculating the resistance of the test fluid, which is an indicator used to determine whether or not conductive impurities are contained in the test fluid, by using the measurement results from the measurement unit 108.

Description

[Technical Field]

[0001] The present disclosure relates to an impurity detection support device and an impurity detection support method. [Background technology]

[0002] When preparing a solid-liquid mixture with electronic conductivity, conductive particles such as metal particles may be mixed in as impurities. When a solid-liquid mixture containing conductive impurities is used in an electronic device, the impurities may cause defects in the electronic device. Examples of electronic devices include energy storage devices such as lithium-ion batteries, lithium-ion secondary batteries, alkaline batteries, electric double-layer capacitors, and electrochemical capacitors. Examples of solid-liquid mixtures include electrode slurries used in these energy storage devices. If conductive impurities are mixed into the electrode slurry, the conductive impurities may cause short circuits between positive and negative electrodes. In response to this issue, for example, Patent Document 1 discloses a method for magnetically detecting metallic foreign matter contained in an aqueous slurry containing an electrode active material and a particulate binder. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2014 / 142045 Summary of the Invention [Problem to be solved by the invention]

[0004] Conventional methods that utilize magnetism to detect conductive impurities have been unable to detect conductive impurities made of non-magnetic materials, resulting in an insufficient detection rate for conductive impurities.

[0005] The present disclosure has been made in view of these circumstances, and its purpose is to provide a technique for increasing the detection rate of conductive impurities in a test liquid. [Means for solving the problem]

[0006] One aspect of the present disclosure is an impurity detection support device. The device includes: a pipe through which a test liquid flows; first and second electrodes disposed within the pipe, the first and second electrodes being capable of applying an AC voltage or superimposing an AC current to the test liquid in a space extending between a first position in the pipe and a second position offset from the first position in the direction of extension of the pipe; a power supply unit that applies the AC voltage or superimposes an AC current between the first and second electrodes; a measurement unit that measures the current generated between the first and second electrodes by applying the AC voltage or the voltage generated between the first and second electrodes by superimposing the AC current; and a calculation unit that uses the measurement results from the measurement unit to calculate the resistance of the test liquid, which serves as an index for determining whether the test liquid contains conductive impurities.

[0007] Another aspect of the present disclosure is an impurity detection support method, which includes flowing a test liquid through a pipe, applying an AC voltage or superimposing an AC current on the test liquid in a space extending between a first position in the pipe and a second position shifted from the first position in the extension direction of the pipe, measuring the current generated by the application of the AC voltage or measuring the voltage generated by the superimposition of the AC current, and using the measurement results to calculate the resistance of the test liquid, which serves as an index for determining whether the test liquid contains conductive impurities.

[0008] Any combination of the above components, and conversion of the expression of the present disclosure into a method, device, system, etc., are also valid aspects of the present disclosure. [Effects of the Invention]

[0009] According to the present disclosure, it is possible to increase the detection rate of conductive impurities in a test liquid. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic diagram of a coating device provided with an impurity detection support device according to a first embodiment. [Figure 2] 2(A) to 2(C) are schematic diagrams of the electrode part. [Figure 3] 4 is a flowchart showing an example of an impurity detection support method according to the first embodiment. [Figure 4] 4(A) to 4(C) are schematic diagrams of an electrode unit provided in the impurity detection support apparatus according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present disclosure will be described below with reference to preferred embodiments and drawings. The embodiments are illustrative and do not limit the present disclosure, and all features and combinations thereof described in the embodiments are not necessarily essential to the present disclosure. The same or equivalent components, parts, and processes shown in each drawing are designated by the same reference numerals, and redundant descriptions will be omitted where appropriate. The scale and shape of each part shown in each drawing are set for convenience to facilitate explanation and should not be interpreted as limiting unless otherwise specified. Furthermore, when terms such as "first" and "second" are used in this specification or claims, unless otherwise specified, these terms do not indicate any order or importance, but are intended to distinguish one configuration from another. Furthermore, some components that are not important for explaining the embodiments are omitted from each drawing.

[0012] (Embodiment 1) FIG. 1 is a schematic diagram of a coating device 1 provided with an impurity detection support device 100 according to a first embodiment. In FIG. 1, some of the components of each device are depicted as functional blocks. These functional blocks are realized as a hardware configuration by elements and circuits such as a computer CPU and memory, and as a software configuration by a computer program or the like. Those skilled in the art will understand that these functional blocks can be realized in various ways by combining hardware and software.

[0013] The coating device 1 includes a coating die 2, a valve 4, a tank 6, a pump 8, a feed pipe 10, a return pipe 12, and a die supply pipe 14.

[0014] The coating die 2 is a tool for applying a coating material 18 to a substrate 16. The coating apparatus 1 of this embodiment is used, for example, to manufacture an electrode plate for a secondary battery. The electrode plate for a secondary battery is a sheet-like electrode material obtained by applying an electrode slurry to a current collector and then drying the applied material. Therefore, in this embodiment, the substrate 16 is the current collector of the secondary battery, and the coating material 18 is the electrode slurry for the secondary battery. The current collector is, for example, a metal foil. The electrode slurry is an electronically conductive solid-liquid mixture containing a solvent and at least one of an electrode active material and a conductive additive. In a typical lithium-ion secondary battery, a positive electrode plate is prepared by applying an electrode slurry containing a positive electrode active material such as lithium cobalt oxide or lithium iron phosphate to an aluminum foil. The positive electrode slurry may also contain a conductive additive such as graphite. A negative electrode plate is prepared by applying an electrode slurry containing a negative electrode active material (or a conductive additive) such as graphite to a copper foil.

[0015] The coating die 2 is disposed so that the discharge port 22 faces the peripheral surface of the backup roll 20 at a predetermined distance. As the backup roll 20 rotates, the object 16 to be coated is continuously transported to a position where the backup roll 20 and the discharge port 22 face each other.

[0016] A valve 4 is connected to the coating die 2 via a die supply pipe 14. The valve 4 can switch between supplying and not supplying paint 18 to the coating die 2. While the paint 18 is being supplied to the coating die 2, the coating device 1 can eject the paint 18 from the coating die 2 onto the object to be coated 16. A tank 6 is connected to the valve 4 via a feed pipe 10 and a return pipe 12.

[0017] Tank 6 stores paint 18. Pump 8 is provided in feed pipe 10, and paint 18 is sent from tank 6 to valve 4 by driving pump 8. Valve 4 supplies paint 18 supplied from tank 6 to coating die 2 via die supply pipe 14. Alternatively, valve 4 returns paint 18 supplied from tank 6 to tank 6 via return pipe 12.

[0018] The valve 4 supplies the coating material 18 to the coating die 2, whereby the coating material 18 is ejected from the coating die 2 to form a coated portion 18a of the coating material 18 on the workpiece 16. The valve 4 also returns the coating material 18 to the tank 6, whereby the application of the coating material 18 from the coating die 2 is stopped and an uncoated portion 16a of the coating material 18 is formed on the workpiece 16. In other words, the valve 4 allows the coating material 18 to be intermittently coated on the workpiece 16. The uncoated portion 16a is used for attaching a center lead of an electrode, etc. Note that the configuration of each part of the coating device 1 is not limited to that described above.

[0019] The coating device 1 is provided with an impurity detection support device 100 according to this embodiment. The impurity detection support device 100 includes a pipe 102, an electrode unit 104, a power supply unit 106, a measurement unit 108, a calculation unit 110, and a determination unit 112.

[0020] The pipe 102 is a flow path through which a test liquid flows, which is to be tested for the presence or absence of conductive impurities. The conductive impurities are, for example, metals. In this embodiment, the area of ​​the feed pipe 10 between the tank 6 and the pump 8 constitutes the pipe 102. In other words, the impurity detection support device 100 is provided in the feed pipe 10. The paint 18, in other words, the electrode slurry, corresponds to the test liquid.

[0021] The impurity detection support device 100 may be provided in a region of the feed pipe 10 between the pump 8 and the valve 4. The impurity detection support device 100 may also be provided in the return pipe 12, the die supply pipe 14, or the like. The coating apparatus 1 may also be interpreted as including a circulation device or a conveying device for the paint 18, which is composed of the tank 6, the pump 8, the feed pipe 10, and the return pipe 12. In this case, the impurity detection support device 100 provided in the feed pipe 10 or the return pipe 12 may also be interpreted as being provided in the circulation device or the conveying device. The coating apparatus 1 is not limited to being used for manufacturing electrode plates for secondary batteries, and the substrate 16 and the paint 18 do not have to be electrode plates or electrode slurry. The impurity detection support device 100 may also be provided in devices other than the coating apparatus 1, such as a manufacturing device for a test liquid.

[0022] The electrode unit 104 includes a first electrode 114 and a second electrode 116. Hereinafter, the first electrode 114 and the second electrode 116 may be collectively referred to as a pair of electrodes as appropriate. FIGS. 2(A) to 2(C) are schematic diagrams of the electrode unit 104. FIG. 2(A) is a first example of the electrode unit 104, FIG. 2(B) is a second example of the electrode unit 104, and FIG. 2(C) is a third example of the electrode unit 104. Note that the power supply unit 106 is not shown in FIGS. 2(B) and 2(C).

[0023] The pair of electrodes is disposed within the pipe 102. The electrode unit 104 of this embodiment has a rod-shaped body 118 that is inserted into the pipe 102 and disposed at a distance from the pipe 102. The first electrode 114 is provided on the pipe 102, and the second electrode 116 is provided on the rod-shaped body 118. The first electrode 114 and the second electrode 116 are insulated from each other. The first electrode 114 and the second electrode 116 are made of an electrically conductive material. The material has, for example, a volume resistivity of 0.1 Ω·cm or less. Specific examples of materials that may be used to form the first electrode 114 and the second electrode 116 include insoluble metals such as stainless steel, titanium, platinum, gold, niobium, and ruthenium, as well as carbon. These materials may also be combined as appropriate.

[0024] The first electrode 114 is provided at least on the inner wall (inner peripheral surface) of the pipe 102. The first electrode 114 may be provided on the entire inner wall of the pipe 102, or on a portion thereof. When the first electrode 114 is provided on a portion of the inner wall, it may be on a partial region in the direction in which the test liquid flows, or on a partial region in the circumferential direction of the pipe 102. Furthermore, the entire pipe 102 may be made of an insoluble metal or the like, and the entire pipe 102 may constitute the first electrode 114. In other words, the first electrode 114 may be provided only on the surface of the inner wall of the pipe 102, or may be provided all the way to the inside of the inner wall.

[0025] The second electrode 116 is provided at least on the outer wall (peripheral surface) of the rod-shaped body 118. The second electrode 116 may be provided on the entire outer wall of the rod-shaped body 118, or on a portion thereof. When the second electrode 116 is provided on a portion of the outer wall, it may be on a partial region in the direction of flow of the test liquid, or on a partial region in the circumferential direction of the rod-shaped body 118. Furthermore, the entire rod-shaped body 118 may be made of an insoluble metal or the like, and the entire rod-shaped body 118 may constitute the second electrode 116. In other words, the second electrode 116 may be provided only on the surface of the outer wall of the rod-shaped body 118, or may be provided inside the outer wall.

[0026] The first electrode 114 and the second electrode 116 are arranged so that an AC voltage can be applied to the test liquid in the space extending between an arbitrary first position 102a of the pipe 102 and a second position 102b shifted from the first position 102a in the extension direction of the pipe 102, or so that an AC current can be superimposed thereon. The first electrode 114 and the second electrode 116 in this embodiment are elongated and extend in the extension direction of the pipe 102. Therefore, the pair of electrodes extend parallel to the axis of the pipe 102 with a gap between them in the radial direction of the pipe 102. Preferably, the pair of electrodes are arranged so that the distance between the pair of electrodes is equal at any position in the extension direction of the pipe 102.

[0027] This allows an AC voltage to be applied or an AC current to be superimposed on the entire test liquid that spreads between the first position 102a and the second position 102b in the extension direction of the pipe 102, in other words, in the flow direction of the test liquid. The distance between the first position 102a and the second position 102b, in other words, the length of the first electrode 114 and the second electrode 116 in the extension direction of the pipe 102, is, for example, equal to or greater than the distance between the pair of electrodes and, for example, equal to or greater than the diameter of the pipe 102.

[0028] Moreover, the rod-shaped body 118 is arranged so that the distance from the inner wall of the pipe 102 is substantially equal at each position in the extension direction of the pipe 102. In other words, the rod-shaped body 118 extends parallel to the axis of the pipe 102. This makes it possible to make the distance between the pair of electrodes (the radial distance of the pipe 102) substantially equal in the extension direction of the pipe 102. As a result, the accuracy of detection of conductive impurities by the impurity detection support device 100 can be improved. Furthermore, the rod-shaped body 118 is arranged so that the distance from the inner wall of the pipe 102 is substantially equal at each position in the circumferential direction of the rod-shaped body 118. In other words, the pipe 102 and the rod-shaped body 118 are arranged coaxially. This makes it possible to make the distance between the pair of electrodes substantially equal in the circumferential direction of the rod-shaped body 118. As a result, the accuracy of detection of conductive impurities by the impurity detection support device 100 can be improved. In other words, the rod-shaped body 118 constituting the second electrode 116 is inserted through the center of the pipe 102 so that it is not biased in the radial direction of the pipe 102 and extends parallel to the extension direction of the pipe 102 without tilting.

[0029] In a first example shown in FIG. 2(A), the rod-shaped body 118 is hollow. The inside of the rod-shaped body 118 is sealed, preventing the test liquid from flowing through the pipe 102. In a second example shown in FIG. 2(B), the rod-shaped body 118 is solid. By using a hollow or solid rod-shaped body 118, it is possible to prevent the rod-shaped body 118 from increasing pressure loss when the test liquid passes through the pipe 102. On the other hand, in a third example shown in FIG. 2(C), the rod-shaped body 118 is a cylindrical mesh. The test liquid can move between the inside and outside of the rod-shaped body 118 through openings in the mesh while flowing through the pipe 102. Using a cylindrical mesh rod-shaped body 118 increases the contact area between the second electrode 116 and the test liquid, thereby improving the accuracy of conductive impurity detection by the impurity detection support device 100.

[0030] The power supply unit 106 applies an AC voltage or superimposes an AC current between the first electrode 114 and the second electrode 116. The power supply unit 106 can be configured with a known AC / DC converter, inverter, control circuit, etc. For example, the first electrode 114 is connected to the negative output terminal of the power supply unit 106, and the second electrode 116 is connected to the positive output terminal of the power supply unit 106. Therefore, the first electrode 114 is the negative electrode, and the second electrode 116 is the positive electrode. Alternatively, the first electrode 114 may be the positive electrode, and the second electrode 116 may be the negative electrode. The control circuit can be configured with, for example, a microcomputer, and can control each switching element of the power supply unit 106 so that the current or voltage maintains a target value according to the measurement result of the measurement unit 108.

[0031] The measuring unit 108 measures the current generated between the first electrode 114 and the second electrode 116 due to the application of an AC voltage. Alternatively, the measuring unit 108 measures the voltage generated between the first electrode 114 and the second electrode 116 due to the superposition of an AC current. When measuring the current generated between the pair of electrodes, the measuring unit 108 can be configured with a known ammeter, FRA (Frequency Response Analyzer), or the like electrically connected to the pair of electrodes. When measuring the voltage generated between the pair of electrodes, the measuring unit 108 can be configured with a known voltmeter, FRA, or the like electrically connected to the pair of electrodes.

[0032] The calculation unit 110 calculates the resistance of the test liquid using the measurement result of the measurement unit 108. As an example, the calculation unit 110 calculates the resistance of the test liquid by an AC impedance method.

[0033] When the power supply unit 106 applies an AC voltage between the pair of electrodes, the current generated between the pair of electrodes via the test liquid is measured by the measurement unit 108. In this case, the calculation unit 110 can calculate the resistance component of the test liquid from the value of this current and the value of the AC voltage applied between the pair of electrodes. The magnitude of the applied AC voltage can be selected appropriately depending on the electrode area, the distance between the electrodes, the type of test liquid, etc., but is preferably 1 to 100 mV, and more preferably 5 to 50 mV. The application time of the AC voltage is not particularly limited. Note that a bias may be applied to the AC voltage.

[0034] Furthermore, when the power supply unit 106 superimposes an AC current between the pair of electrodes, the voltage generated between the pair of electrodes via the test liquid is measured by the measurement unit 108. In this case, the calculation unit 110 can calculate the resistance component of the test liquid from the value of this voltage and the value of the AC current superimposed between the pair of electrodes. The magnitude of the superimposed AC current can be selected appropriately depending on the electrode area, the distance between the electrodes, the type of test liquid, etc., but is preferably 5 nA to 5 A, and more preferably 50 nA to 500 mA. The superimposition time of the AC current is not particularly limited. Note that a bias may be applied to the AC current.

[0035] In particular, it is preferable to apply an AC voltage between a pair of electrodes and calculate the resistance of the test liquid by an AC impedance method. The frequency of the AC can be selected appropriately depending on the electrode area, the distance between the electrodes, the type of test liquid, etc., but is preferably 1 Hz to 1,000,000 Hz, and more preferably 10,000 Hz to 1,000,000 Hz. This can shorten the time required to calculate the resistance and further improve the accuracy of the resistance calculation.

[0036] When conductive impurities such as metals are mixed into the solid-liquid mixture that is the test liquid, the resistance of the test liquid decreases regardless of whether the impurities are magnetic or non-magnetic. In other words, the resistance of the test liquid serves as an indicator for determining whether the test liquid contains conductive impurities. Therefore, by capturing changes in the resistance of the test liquid flowing through the pipe 102 through resistance measurement using the AC impedance method, the presence of conductive impurities can be detected.

[0037] The determination unit 112 determines whether the test liquid contains conductive impurities based on the resistance calculated by the calculation unit 110. For example, the determination unit 112 pre-stores the resistance value of the test liquid that does not contain conductive impurities as a reference value. The determination unit 112 compares the resistance calculated by the calculation unit 110 with the reference value. When the difference between the calculated resistance and the reference value exceeds a predetermined threshold, the determination unit 112 determines that the test liquid contains conductive impurities. The threshold can be set appropriately by a designer based on experiments, simulations, etc. For example, the threshold may be zero.

[0038] The determination unit 112 can also determine whether the test liquid contains conductive impurities as follows. Specifically, the electrode unit 104 of this embodiment generates an electric field in the test liquid within the space extending between the first position 102a and the second position 102b. This allows an AC voltage or AC current to be continuously applied to the test liquid or superimposed thereon for a predetermined continuous period of time, rather than instantaneously. The power supply unit 106 then continuously or stepwise changes the frequency of the AC voltage or AC current applied to the test liquid. The measurement unit 108 then measures the current or voltage generated between the pair of electrodes at multiple different frequencies. This allows the calculation unit 110 to calculate the resistance of the test liquid at each frequency. The determination unit 112 determines the presence or absence of conductive impurities based on the multiple resistances calculated by the calculation unit 110. For example, the determination unit 112 determines whether the difference between the resistance value at each frequency and the corresponding reference value exceeds a threshold value. These determination results are then combined to determine the presence or absence of conductive impurities, for example, based on the number of threshold-exceeding determinations. This improves the accuracy of conductive impurity detection.

[0039] The determination unit 112 can also determine the presence or absence of conductive impurities based on the size of the arc in the equivalent circuit model obtained by the AC impedance method. Furthermore, the determination unit 112 may determine the presence or absence of conductive impurities based on the capacitance (electrostatic capacity) of the test liquid in addition to the resistance of the test liquid.

[0040] As an example, the determination result of the determination unit 112 is sent to the control device 24. The control device 24 may display the determination result of the determination unit 112 on a monitor (not shown). Furthermore, when the determination unit 112 determines that the test liquid contains conductive impurities, the control device 24 may notify the user of the impurity detection support device 100 of the determination result by a known notification method. The notification method is not particularly limited, and known methods such as emitting a notification sound or turning on a notification light can be used. These methods allow the user to monitor the presence or absence of conductive impurities in real time. Furthermore, the user can more quickly recognize the presence of conductive impurities.

[0041] Furthermore, the voltage and current values ​​measured by the measuring unit 108 may be sent to the control device 24. The control device 24 may display the waveforms of the voltage and current values ​​on an oscilloscope (not shown). Furthermore, the resistance value calculated by the calculation unit 110 may be sent to the control device 24. The control device 24 may display the resistance value on a monitor. The resistance value displayed on the monitor may be a plurality of resistance values ​​obtained by changing the frequency of the AC voltage or AC current. In this case, the user can determine the presence or absence of conductive impurities from the resistance value displayed on the monitor. If the resistance value itself is used by the user, the determination unit 112 may be omitted.

[0042] For example, the execution of the impurity detection process can be instructed by a user via the control device 24 or by an operation program in the control device 24. The same applies to changing the settings of the impurity detection process. The control device 24 may also control the valve 4 and the pump 8.

[0043] 3 is a flowchart showing an example of the impurity detection support method according to Embodiment 1. This flow is executed repeatedly at predetermined timings, for example.

[0044] First, an AC voltage is applied between the first electrode 114 and the second electrode 116, or an AC current is superimposed thereon (S101). Next, the current generated between the first electrode 114 and the second electrode 116 due to the application of the AC voltage is measured, or the voltage generated between the first electrode 114 and the second electrode 116 due to the superimposition of the AC current is measured (S102). Next, the resistance of the test liquid is calculated based on the measured current or voltage (S103). Then, it is determined whether the difference between the calculated resistance value and a reference value exceeds a threshold value (S104).

[0045] If the difference between the resistance value and the reference value exceeds the threshold value (Y in S104), the user is notified that the test liquid contains impurities (S105), and this routine ends. If the difference between the resistance value and the reference value is equal to or less than the threshold value (N in S104), this routine ends without notifying the user. In step S104, whether the difference between one resistance value and the reference value exceeds the threshold value is used to determine whether the test liquid contains conductive impurities. However, this is not limiting, and it is also possible to determine whether the difference between a reference value and a resistance value obtained by changing the frequency of the AC voltage or AC current exceeds the threshold value, and to combine the multiple determination results to determine whether the test liquid contains conductive impurities.

[0046] As described above, the impurity detection support device 100 of this embodiment comprises a pipe 102 through which a test liquid flows, a first electrode 114 and a second electrode 116 arranged within the pipe 102, the first electrode 114 and the second electrode 116 being arranged so that an AC voltage can be applied or an AC current can be superimposed to the test liquid in the space extending between a first position 102a of the pipe 102 and a second position 102b shifted from the first position 102a in the extension direction of the pipe 102, i.e., to the entire test liquid extending within the space, a power supply unit 106 that applies an AC voltage or superimposes an AC current between this pair of electrodes, a measurement unit 108 that measures the current generated between the pair of electrodes by applying an AC voltage or measures the voltage generated between the pair of electrodes by superimposing an AC current, and a calculation unit 110 that uses the measurement results of the measurement unit 108 to calculate the resistance of the test liquid, which is an indicator for determining whether the test liquid contains conductive impurities.

[0047] The impurity detection support device 100 of this embodiment applies an AC voltage or superimposes an AC current on the test liquid to measure resistance, which serves as an indicator for determining whether conductive impurities are present. Therefore, even if the impurities are non-magnetic, a highly reliable indicator can be obtained. This increases the detection rate of conductive impurities in the test liquid. Furthermore, because an electric field is generated in the test liquid flowing through the pipe 102, conductive impurities can be detected while the test liquid is being transported. In other words, in-line impurity detection processing can be achieved. Furthermore, because sample collection and other operations are not required, full-volume testing of the test liquid can be easily achieved. This reduces the introduction of foreign matter into the next process.

[0048] Furthermore, an AC voltage is applied to the test liquid in the space extending between a first position 102a of the pipe 102 and a second position 102b shifted from the first position 102a in the direction of extension of the pipe, or an AC current is superimposed on the test liquid. This allows the area through which the conductive impurities are energized to be expanded in the direction of flow of the test liquid, thereby improving the detection efficiency of the conductive impurities.

[0049] As an example, the test liquid is an electrode slurry containing a solvent and at least one of an electrode active material and a conductive additive. In this case, highly accurate detection of conductive impurities can prevent short circuits between positive and negative electrodes caused by the conductive impurities themselves. Furthermore, in an energy storage device in which an electrolyte is interposed between positive and negative electrodes, if the positive electrode slurry contains conductive impurities (particularly metal impurities), the conductive impurities may dissolve into the electrolyte during charging of the energy storage device, be reduced on the surface of the negative electrode, and precipitate. If this precipitation occurs repeatedly, the conductive impurities grow into dendrites, penetrate the separator, and reach the positive electrode, causing a short circuit. Therefore, increasing the detection rate of conductive impurities can also prevent short circuits caused by dendrites.

[0050] As another example, the piping 102 is provided in a coating apparatus 1 that includes a coating die 2 that applies the test liquid to the workpiece 16 and a tank 6 that stores the test liquid. Alternatively, the piping 102 is provided in a circulation device or transport device for the test liquid. This makes it possible to perform impurity detection processing on the test liquid while it is being transported from the tank 6 to the coating die 2. Furthermore, by arranging the impurity detection support device 100 in the feed piping 10 or the die supply piping 14 of the coating apparatus 1, it is possible to perform impurity detection processing on the test liquid up until just before it is applied to the workpiece 16. This can further reduce the risk of foreign matter getting into the electronic device, thereby improving the performance of the electronic device.

[0051] Furthermore, the impurity detection support device 100 can be attached to an existing device by simply using part of the piping in the existing device as the piping 102, or by simply replacing part of the piping with the piping 102 of the impurity detection support device 100. Therefore, the impurity detection support device 100 can be easily installed, replaced, and maintained.

[0052] The impurity detection support device 100 of this embodiment also includes a determination unit 112 that determines whether the test liquid contains conductive impurities based on the resistance calculated by the calculation unit 110. This allows the user to more quickly determine whether the test liquid contains conductive impurities.

[0053] As an example of determining whether conductive impurities are contained, the power supply unit 106 changes the frequency of the applied AC voltage or the superimposed AC current continuously or stepwise, the measurement unit 108 measures the current or voltage at different frequencies, the calculation unit 110 calculates multiple resistances from the current or voltage at each frequency, and the determination unit 112 determines whether conductive impurities are contained based on the multiple resistances. This can further improve the accuracy of detecting conductive impurities.

[0054] In addition, the first electrode 114 and the second electrode 116 in this embodiment are elongated and extend in the extension direction of the pipe 102. This allows the region in which an electric field is generated to be more easily expanded in the extension direction of the pipe 102. Furthermore, the first electrode 114 is provided on the pipe 102, and the second electrode 116 is provided on a rod-shaped body 118 inserted into the pipe 102. The rod-shaped body 118 is disposed at a distance from the pipe 102 and extends parallel to the axis of the pipe 102. This makes it easier to maintain a uniform distance between the pair of electrodes throughout the entire region, even when the region in which an electric field is generated is expanded in the extension direction of the pipe 102, allowing the electric field to be generated more uniformly throughout the entire region. Furthermore, the rod-shaped body 118 is a hollow body, a solid body, or a cylindrical mesh. If the rod-shaped body 118 is a hollow body or a solid body, an increase in pressure loss when the test liquid passes through the pipe 102 can be suppressed. When the rod-shaped body 118 is a cylindrical mesh, the contact area between the second electrode 116 and the test liquid can be increased, thereby increasing the detection rate of impurities.

[0055] (Embodiment 2) The second embodiment has a common configuration with the first embodiment, except for the shapes and arrangements of the first electrode 114 and the second electrode 116. The following description of the second embodiment will focus on the configurations that are different from the first embodiment, and the common configurations will be explained briefly or omitted.

[0056] 4(A) to 4(C) are schematic diagrams of the electrode unit 104 included in the impurity detection support apparatus 100 according to embodiment 2. Fig. 4(A) is a fourth example of the electrode unit 104, Fig. 4(B) is a fifth example of the electrode unit 104, and Fig. 4(C) is a sixth example of the electrode unit 104. Note that the power supply unit 106 is not shown in Figs. 4(B) and 4(C).

[0057] In this embodiment, the first electrode 114 extends in a direction intersecting the extension direction of the pipe 102 at the first position 102a. The second electrode 116 extends in a direction intersecting the extension direction of the pipe 102 at the second position 102b. That is, each of the pair of electrodes is filter-shaped and extends in the radial direction of the pipe 102. This allows the area through which conductive impurities are conducted to be expanded in a direction intersecting the flow direction of the test liquid, thereby improving the detection efficiency of conductive impurities.

[0058] The first electrode 114 and the second electrode 116 are fixed to, for example, the pipe 102. If the pipe 102 is made of metal, insulation is provided between each electrode and the pipe 102. If the pipe 102 is made of a non-metal, insulation between each electrode and the pipe 102 can be omitted, and the electrodes may be in direct contact with each other.

[0059] In a fourth example shown in FIG. 4(A), the first electrode 114 and the second electrode 116 are mesh sheets. In a fifth example shown in FIG. 4(B), the first electrode 114 and the second electrode 116 are slit sheets. In a sixth example shown in FIG. 4(C), the first electrode 114 and the second electrode 116 are porous sheets. The test liquid flowing through the pipe 102 can pass through the mesh of each electrode and proceed downstream of each electrode. By making each electrode filter-shaped, the contact area between each electrode and the test liquid can be increased, thereby improving the accuracy of detecting conductive impurities by the impurity detection support device 100.

[0060] The above describes the embodiments of the present disclosure in detail. The above-described embodiments merely illustrate specific examples of implementing the present disclosure. The content of the embodiments does not limit the technical scope of the present disclosure, and many design modifications, such as changing, adding, or deleting components, are possible within the scope of the concept of the present disclosure defined in the claims. A new embodiment with design modifications will combine the effects of the combined embodiments and modifications. In the above-described embodiments, the content in which such design modifications are possible is emphasized by using notations such as "in this embodiment" or "in this embodiment," but design modifications are also permitted even in content without such notation. Any combination of the above components is also valid as an aspect of the present disclosure. Hatching in cross sections in the drawings does not limit the material of the hatched object.

[0061] The invention according to the above-described embodiment may be specified by the following items. [Item 1] a pipe (102) through which the test liquid flows; a first electrode (114) and a second electrode (116) disposed in the pipe (102), the first electrode (114) and the second electrode (116) being disposed so as to be able to apply an AC voltage to a test liquid in a space extending between a first position (102a) of the pipe (102) and a second position (102b) displaced from the first position (102a) in the extending direction of the pipe (102), or to be able to superimpose an AC current thereon; a power supply unit (106) that applies an AC voltage or superimposes an AC current between the first electrode (114) and the second electrode (116); a measuring unit (108) that measures a current generated between the first electrode (114) and the second electrode (116) by applying an AC voltage, or that measures a voltage generated between the first electrode (114) and the second electrode (116) by superimposing an AC current; a calculation unit (110) that calculates the resistance of the test liquid, which serves as an index for determining whether or not the test liquid contains conductive impurities, using the measurement result of the measurement unit (108); Impurity detection support device (100). [Item 2] a determination unit (112) that determines whether or not the test liquid contains conductive impurities based on the resistance calculated by the calculation unit (110); Item 1. An impurity detection support device (100) according to item 1. [Item 3] The power supply unit (106) changes the frequency of the applied voltage or the superimposed current continuously or stepwise, The measuring unit (108) measures the current or voltage at different frequencies, The calculation unit (110) calculates a plurality of resistances from the current or voltage at each frequency, The determination unit (112) determines whether or not conductive impurities are contained based on the plurality of resistances. Item 2. An impurity detection support device. [Item 4] The first electrode (114) and the second electrode (116) are elongated and extend in the extension direction. An impurity detection support device (100) according to any one of items 1 to 3. [Item 5] The first electrode (114) is provided in the pipe (102), The second electrode (116) is provided on a rod-shaped body (118) that is inserted into the pipe (102) and is spaced apart from the pipe (102). Item 4. An impurity detection support device (100) according to item 4. [Item 6] The rod-shaped body (118) extends parallel to the axis of the pipe (102). Item 6. An impurity detection support device according to item 5. [Item 7] The rod (118) may be a hollow body, a solid body, or a cylindrical mesh. 7. The impurity detection support device (100) according to item 5 or 6. [Item 8] The first electrode (114) extends in a direction intersecting the extending direction at the first position (102a), The second electrode (116) extends in a direction intersecting the extending direction at the second position (102b). An impurity detection support device (100) according to any one of items 1 to 3. [Item 9] The first electrode (114) and the second electrode (116) are mesh sheets, slit sheets, or porous sheets. Item 8. An impurity detection support device (100) according to item 8. [Item 10] The test liquid is an electrode slurry containing a solvent and at least one of an electrode active material and a conductive assistant. 10. An impurity detection support device (100) according to any one of items 1 to 9. [Item 11] The piping (102) is provided in at least one of a coating device (1) that applies the test liquid to the object to be coated (16), a circulating device for the test liquid, and a conveying device for the test liquid. An impurity detection support device (100) according to any one of items 1 to 10. [Item 12] The liquid to be inspected is passed through the pipe (102), applying an AC voltage or superimposing an AC current to the test liquid in a space extending between a first position (102a) of the pipe (102) and a second position (102b) shifted from the first position (102a) in the extending direction of the pipe (102); Measure the current generated by applying an AC voltage or measure the voltage generated by superimposing an AC current; Calculating the resistance of the test liquid, which serves as an index for determining whether or not the test liquid contains conductive impurities, using the measurement results. Methods to assist in detecting impurities. [Item 13] determining whether or not the test liquid contains conductive impurities based on the calculated resistance; Item 13. The impurity detection support method according to Item 12. [Item 14] When applying an AC voltage or superimposing an AC current, the frequency of the AC voltage or AC current is changed continuously or stepwise, In the measurement, the current or voltage is measured at different frequencies, In the calculation, multiple resistances are calculated from the current or voltage at each frequency, In the determination, it is determined whether or not conductive impurities are contained according to the plurality of resistances. Item 14. The impurity detection support method according to Item 13. [Industrial Applicability]

[0062] The present disclosure can be used in an impurity detection support device and an impurity detection support method. [Explanation of symbols]

[0063] 1 Coating device, 2 Coating die, 6 Tank, 16 Object to be coated, 100 Impurity detection support device, 102 Pipe, 102a First position, 102b Second position, 106 Power supply unit, 108 Measurement unit, 110 Calculation unit, 112 Determination unit, 114 First electrode, 116 Second electrode, 118 Rod-shaped body.

Claims

1. A coating device that applies a test liquid to a substrate, comprising: The coating device is equipped with an impurity detection support device, The impurity detection support device includes: A pipe through which the test liquid flows; a first electrode and a second electrode disposed in the pipe, the first electrode and the second electrode being disposed so as to be able to apply an AC voltage to the test liquid in a space extending between a first position of the pipe and a second position shifted from the first position in the extending direction of the pipe, or to be able to superimpose an AC current thereon; a power supply unit that applies an AC voltage or superimposes an AC current between the first electrode and the second electrode; a measurement unit that measures a current generated between the first electrode and the second electrode by applying the AC voltage, or that measures a voltage generated between the first electrode and the second electrode by superimposing the AC current; a calculation unit that calculates the resistance of the test liquid, which serves as an index for determining whether or not the test liquid contains conductive impurities, using the measurement result of the measurement unit; The test liquid is an electrode slurry containing a solvent and at least one of an electrode active material and a conductive assistant. Coating equipment.

2. A circulating device for a test liquid, comprising: the circulation device includes an impurity detection support device; The impurity detection support device includes: A pipe through which the test liquid flows; a first electrode and a second electrode disposed in the pipe, the first electrode and the second electrode being disposed so as to be able to apply an AC voltage to the test liquid in a space extending between a first position of the pipe and a second position shifted from the first position in the extending direction of the pipe, or to be able to superimpose an AC current thereon; a power supply unit that applies an AC voltage or superimposes an AC current between the first electrode and the second electrode; a measurement unit that measures a current generated between the first electrode and the second electrode by applying the AC voltage, or that measures a voltage generated between the first electrode and the second electrode by superimposing the AC current; a calculation unit that calculates the resistance of the test liquid, which serves as an index for determining whether or not the test liquid contains conductive impurities, using the measurement result of the measurement unit; The test liquid is an electrode slurry containing a solvent and at least one of an electrode active material and a conductive assistant. Circulation device.

3. A transport device for a test liquid, comprising: the transport device is equipped with an impurity detection support device, The impurity detection support device includes: A pipe through which the test liquid flows; a first electrode and a second electrode disposed in the pipe, the first electrode and the second electrode being disposed so as to be able to apply an AC voltage to the test liquid in a space extending between a first position of the pipe and a second position shifted from the first position in the extending direction of the pipe, or to be able to superimpose an AC current thereon; a power supply unit that applies an AC voltage or superimposes an AC current between the first electrode and the second electrode; a measurement unit that measures a current generated between the first electrode and the second electrode by applying the AC voltage, or that measures a voltage generated between the first electrode and the second electrode by superimposing the AC current; a calculation unit that calculates the resistance of the test liquid, which serves as an index for determining whether or not the test liquid contains conductive impurities, using the measurement result of the measurement unit; The test liquid is an electrode slurry containing a solvent and at least one of an electrode active material and a conductive assistant. Conveying device.

4. The impurity detection support device includes a determination unit that determines whether the test liquid contains the conductive impurities based on the resistance calculated by the calculation unit. The coating device according to claim 1 .

5. The impurity detection support device includes a determination unit that determines whether the test liquid contains the conductive impurities based on the resistance calculated by the calculation unit. The circulation device according to claim 2 .

6. The impurity detection support device includes a determination unit that determines whether the test liquid contains the conductive impurities based on the resistance calculated by the calculation unit. The conveying device according to claim 3 .

7. the power supply unit changes the frequency of the applied AC voltage or the superimposed AC current continuously or stepwise; the measuring unit measures current or voltage at different frequencies; the calculation unit calculates a plurality of resistances from the current or voltage at each frequency, the determining unit determines whether the conductive impurities are contained or not based on the plurality of resistances. The coating device according to claim 4.

8. The power supply unit changes the frequency of the applied AC voltage or the superimposed AC current continuously or stepwise, the measuring unit measures current or voltage at different frequencies; the calculation unit calculates a plurality of resistances from the current or voltage at each frequency, the determining unit determines whether the conductive impurities are contained or not based on the plurality of resistances. The circulation device according to claim 5 .

9. The power supply unit changes the frequency of the applied AC voltage or the superimposed AC current continuously or stepwise, the measuring unit measures current or voltage at different frequencies; the calculation unit calculates a plurality of resistances from the current or voltage at each frequency, the determining unit determines whether the conductive impurities are contained or not based on the plurality of resistances. The conveying device according to claim 6.

10. The first electrode and the second electrode are elongated and extend in the extension direction. The coating device according to any one of claims 1, 4 and 7.

11. The first electrode and the second electrode are elongated and extend in the extension direction.

9. The circulation device according to claim 2, 5 or 8.

12. The first electrode and the second electrode are elongated and extend in the extension direction.

10. A conveying device according to any one of claims 3, 6 and 9.

13. the first electrode is provided on the pipe, The second electrode is provided on a rod-shaped body that is inserted into the pipe and is arranged at a distance from the pipe. The coating device according to claim 10.

14. The first electrode is provided in the piping, The second electrode is provided on a rod-shaped body that is inserted into the pipe and is arranged at a distance from the pipe. The circulation device according to claim 11.

15. The first electrode is provided in the piping, The second electrode is provided on a rod-shaped body that is inserted into the pipe and is arranged at a distance from the pipe.

13. The conveying device of claim 12.

16. The rod-shaped body extends parallel to the axis of the pipe. The coating device according to claim 13.

17. The rod-shaped body extends parallel to the axis of the pipe. The circulation device of claim 14.

18. The rod-shaped body extends parallel to the axis of the piping.

16. The conveying device of claim 15.

19. The rod-shaped body is a hollow body, a solid body, or a cylindrical mesh. The coating device according to claim 13 or 16.

20. The rod-shaped body is a hollow body, a solid body, or a cylindrical mesh.

18. The circulation device according to claim 14 or 17.

21. The rod-shaped body is a hollow body, a solid body, or a cylindrical mesh.

19. A conveying device according to claim 15 or 18.

22. the first electrode extends in a direction intersecting the extending direction at the first position; the second electrode extends in a direction intersecting the extending direction at the second position; The coating device according to any one of claims 1, 4 and 7.

23. The first electrode extends in a direction intersecting the extension direction at the first position, the second electrode extends in a direction intersecting the extending direction at the second position; 9. The circulation device according to claim 2, 5 or 8.

24. The first electrode extends in a direction intersecting the extension direction at the first position, the second electrode extends in a direction intersecting the extending direction at the second position; 10. A conveying device according to any one of claims 3, 6 and 9.

25. The first electrode and the second electrode are a mesh sheet, a slit sheet, or a porous sheet.

23. The coating device according to claim 22.

26. The first electrode and the second electrode are a mesh sheet, a slit sheet, or a porous sheet.

24. The circulation device of claim 23.

27. ​​The first electrode and the second electrode are a mesh sheet, a slit sheet, or a porous sheet.

25. The transport device of claim 24.

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