JP2015035294A - Manufacturing method for electrode and inspection device of electrode - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method for electrode and an inspection device of electrode in which inspection results of an active material layer can be reflected quickly on the manufacturing process, for the active material layer on a metal foil.SOLUTION: In the inspection of an electrode (e.g., SiO negative electrode) where an active material layer is formed by coating a metal foil L with an electrode paste P, a strip metal foil L is coated with an electrode paste P for electrode and the place other than a part being cut as an electrode is coated with an electrode paste P for inspection. The electrode paste P for inspection thus applied is analyzed by emission spectroscopic analysis (e.g., vacuum emission spectrometry 40).

Description

  The present invention relates to an electrode manufacturing method and an inspection apparatus in which an active material layer is formed by applying an electrode paste to a metal foil.

  The electrode of the power storage device has an active material layer formed by applying an electrode paste to a metal foil. The electrode paste contains an active material, a conductive aid, a binder, and the like. In order to manufacture a high-quality electrode, the ratio of each of these substances contained in the active material layer is important. Therefore, it is necessary to inspect the active material layer, and it has been proposed to use an optical emission spectroscopy (OES [Optical Emission Spectroscopy]) for the inspection. For example, Patent Document 1 discloses that the abundance of an element is analyzed by high-frequency plasma emission spectrometry for a positive electrode of a lithium ion secondary battery. Patent Document 2 discloses analyzing the binding state of the active material by glow discharge emission spectroscopic analysis of the negative electrode active material of the lithium ion secondary battery. Further, Patent Document 3 describes that a mixing condition in a container into which an active material, a conductive additive, a binder, and the like are added and kneaded is inspected using a fluorescent material.

JP 2010-118179 A JP 2012-89267 A JP 2010-277821 A

  In Patent Documents 1 and 2, the manufactured electrode is analyzed, and after the manufacturing, it is inspected before shipment. For this reason, even if it is found from the analysis result that the ratio of the electrode paste is not appropriate, it cannot be quickly reflected in the manufacturing process. As a result, many electrodes after being manufactured are defective. Patent document 3 inspects the mixing condition in the container which knead | mixes an electrode paste. However, in the electrode paste, separation of substances having different specific gravities and aggregation of some substances proceed with time, and therefore, there may be places where the dispersion state of each substance is not appropriate when applied on a metal foil. With the technique of Patent Document 3, it is impossible to detect a problem in a state where such an active material layer is formed.

  Then, this invention makes it a subject to provide the manufacturing method of an electrode and the inspection apparatus of an electrode which can reflect the inspection result of an active material layer to a manufacturing process rapidly about the active material layer on metal foil.

  An electrode manufacturing method according to the present invention is an electrode manufacturing method in which an electrode paste is applied to a metal foil to form an active material layer, and is used for inspection at a place other than a portion cut as an electrode on a strip-shaped metal foil. And an analysis process for analyzing the electrode paste applied in the inspection coating process by emission spectroscopic analysis.

  In this manufacturing method, an electrode paste for inspection is applied to a portion that is not used as an electrode of a strip-shaped metal foil during manufacturing of the electrode. Since this part is not used as an electrode (since it is usually discarded), it can be effectively used for inspection using emission spectroscopic analysis which is destructive analysis. The state of the active material layer can be quickly grasped by applying the electrode paste for inspection to the strip-shaped metal foil in the middle of manufacturing the electrode and performing the emission spectroscopic analysis on the electrode paste for inspection during the electrode manufacturing. .

  In the said manufacturing method of this invention, it is suitable if the result analyzed at the analysis process is reflected in the kneading | mixing conditions of an electrode paste.

  In this manufacturing method, if the ratio of each substance contained in the electrode paste is known by performing an emission spectroscopic analysis on the electrode paste for inspection, the electrode is adjusted to an appropriate ratio using the actual ratio during the manufacturing. Correct paste kneading conditions. In this way, by performing the emission spectroscopic analysis using the previously discarded portion of the strip-shaped metal foil, the analysis result can be quickly reflected in the electrode paste kneading conditions in the manufacturing process.

  In the manufacturing method of the present invention, the electrode to be inspected is a negative electrode, and the electrode paste of the negative electrode preferably includes at least a silicon oxide active material and a carbon-containing conductive additive.

  The emission spectroscopic analysis (particularly, the spark discharge emission spectroscopic analysis) is excellent in the analysis of elements such as silicon (Si) and carbon (C), and the content of each of these elements can be measured with high accuracy. Therefore, an electrode paste made of a material containing each of these elements can be analyzed with high accuracy. Therefore, the inspection object is a negative electrode, and the negative electrode is a negative electrode manufactured using an electrode paste containing at least a silicon oxide active material and a carbon-containing conductive additive.

  In the inspection application step of the manufacturing method of the present invention, it is preferable to apply an inspection electrode paste to both ends of the band-shaped metal foil in the width direction.

  In this manufacturing method, an inspection electrode paste is applied to both ends in the width direction of the strip-shaped metal foil, and emission spectroscopic analysis is performed on each of the inspection electrode pastes applied to each end in the width direction. . Thus, this manufacturing method can analyze the ratio of each substance contained in the electrode paste for inspection at both ends in the width direction, and each substance contained in the electrode paste in the width direction from the analysis result at both ends. It is possible to inspect whether the ratio is uniform or varied.

  The electrode inspection apparatus according to the present invention is an electrode inspection apparatus in which an electrode paste is applied to a metal foil to form an active material layer, and is used for inspection at a place other than a portion cut as an electrode on a strip-shaped metal foil. An inspection application means for applying the electrode paste and an analysis means for analyzing the electrode paste applied by the inspection application means by emission spectroscopic analysis. This inspection apparatus operates in the same manner as the above manufacturing method and has the same effects.

  According to the present invention, by applying an electrode paste for inspection to a portion other than a portion cut out as an electrode in a strip-shaped metal foil, and performing an emission spectroscopic analysis on the electrode paste for inspection, For the active material layer on the foil, the inspection result of the active material layer can be quickly reflected in the manufacturing process.

It is a figure which shows typically the manufacturing apparatus of the electrode containing the test process which concerns on this Embodiment. It is a figure which shows the application | coating state of the electrode paste in the case of two strips, (a) is the case where the electrode paste for a test | inspection is not apply | coated, and (b) is the case where the electrode paste for a test | inspection is applied It is. It is a figure which shows the application | coating state of the electrode paste in the case of 1 line | wire taking, (a) is the case where the electrode paste for a test | inspection is not apply | coated, and (b) is the case where the electrode paste for a test | inspection is applied It is.

  Embodiments of an electrode inspection apparatus and a manufacturing method using the inspection apparatus according to the present invention will be described below with reference to the drawings. In addition, the same code | symbol is attached | subjected about the element which is the same or it corresponds in each figure, and the overlapping description is abbreviate | omitted.

  In the present embodiment, the present invention is applied to an inspection device incorporated in a production line for a SiO negative electrode (electrode) of a power storage device, and a manufacturing method that reflects an inspection result of the inspection device. In the present embodiment, a kneading process, a coating process, and a drying process related to the implementation of the present invention will be described in the electrode manufacturing line, and description of other electrode manufacturing processes will be omitted. The manufactured electrode is used for, for example, a lithium ion secondary battery.

The SiO negative electrode has an active material layer formed by applying an electrode paste to at least one surface of a metal foil, and also has a tab to which no electrode paste is applied. The metal foil is, for example, a copper foil. The electrode paste contains an active material, a conductive aid, a binder, a solvent, and the like. The active material is silicon oxide (SiO _x (0.5 ≦ x ≦ 1.5)). The conductive auxiliary agent is a carbon-based material containing carbon (C), and examples thereof include carbon black, graphite, acetylene black, and ketjen black. The binder is, for example, a thermoplastic resin such as polyamideimide or polyimide, or a polymer resin having an imide bond in the main chain. Examples of the solvent include organic solvents such as NMP (N-methylpyrrolidone), methanol, and methyl isobutyl ketone, and water.

  In addition, in order for the SiO negative electrode to exhibit good performance as an electrode, the ratio of the active material and the conductive additive is important. If this ratio is not an appropriate ratio set in advance by experiment or the like, good performance as an electrode cannot be exhibited. Therefore, it is necessary to accurately analyze the ratio between the active material and the conductive additive in the active material layer (particularly, the ratio between silicon (Si) contained in the active material and carbon (C) contained in the conductive additive). .

  With reference to FIG. 1, a production line 1 (including a kneading step, a coating step, a drying step, and an inspection step) that is a part of the production line for the SiO negative electrode and according to the present embodiment will be described.

  In the production line 1, the ratio of silicon (Si) to carbon (C) contained in the active material layer on the metal foil is analyzed in the process before producing the SiO negative electrode and assembling the battery. This analysis result is reflected in the electrode paste kneading step, which is the previous step of the coating step. In the production line 1 of this embodiment, cant back is used for elemental analysis of silicon and carbon.

  The cant back is one of inspection apparatuses that use an emission spectroscopic analysis method, and is an emission spectroscopic analysis apparatus that gives electric energy to an inspection object by spark discharge. The emission spectroscopic analysis method analyzes an emission line spectrum emitted by an atom excited by electric energy, and is therefore excellent in analyzing a material in which different elements such as silicon as an active material and carbon as a conductive aid are mixed. In addition, in the emission spectroscopic analysis method, spark discharge or arc discharge is used for the inspection object, so that it is a substantial destruction analysis, but unlike the analysis method using X-rays, a shielding facility is unnecessary, and during the manufacturing process. Easy installation with other devices.

  The production line 1 includes a coating process 2 for coating the electrode paste P on the strip-shaped metal foil L, a drying process 3 for drying the electrode paste P coated on the metal foil L to form an active material layer, and an active material. An inspection process 4 for inspecting (analyzing) the layer is included. In the coating process 2, the drying process 3, and the inspection process 4, the strip-shaped metal foil L is fed out from the unwinding roll 5, and is sequentially wound up by the winding roll 6 after passing through each process. The conveying speed of the metal foil L by the unwinding roll 5, the winding roll 6, and the plurality of auxiliary rolls 7 is controlled by a driving device (not shown) that drives each roll. This conveyance speed is, for example, 10 m / min. In the production line 1, in the electrode paste kneading step before the coating step 2, an active material, a conductive additive, a binder, a solvent, and the like are kneaded to generate an electrode paste P in a well dispersed state.

  The kneading step is a step of generating an electrode paste. An appropriate amount of container 20 and stirring means (stirring blade 20a) disposed in container 20 for kneading and dispersing each substance, and active material / conductive aid / binder / solvent (solvent) in container 20 Is provided with an input means (input port 20b). Each substance put into the container 20 is stirred by a stirring means, and is produced into an electrode paste P having a good dispersion state and a viscosity suitable for application.

  The coating process 2 is a process of coating an electrode paste P for an electrode for forming an active material layer on the strip-shaped metal foil L. The coating process 2 includes a gun 23 for coating the electrode paste P on the metal foil L. The electrode paste P is supplied to the gun 23 from the container 20 through the supply pipe 21 by the pump 22. In addition, a coating roll 24 is disposed facing the gun 23 and supports the metal foil L. In the gun 23, the supplied electrode paste P temporarily accumulates in the internal manifold 23a, the electrode paste P is pushed out from the manifold 23a to the nozzle 23b at the tip, and the electrode paste P is discharged onto the metal foil L from the nozzle 23b. As described above, the gun 23 forms a part of a die type coating apparatus. In the coating step 2, continuous application is performed in the case of two strips of electrodes as shown in FIG. 2, and intermittent coating is performed in the case of one strip as shown in FIG. Control of the pump 22 and the like in the coating process 2 corresponding to the continuous coating or intermittent coating is performed by a control device (not shown).

  In addition, in application | coating with the gun | dye 23 of the application | coating process 2, the application | coating of the electrode paste for a test | inspection (for analysis) used in the test | inspection process 4 is also performed besides application | coating of the electrode paste for electrodes for forming an active material layer. The location where the electrode paste P for inspection is applied is a location other than the portion cut out as an electrode in the strip-shaped metal foil L. Since the part other than the part cut out as this electrode is not used as an electrode (since it is usually discarded), it is effectively used for inspection. A specific method of applying the electrode paste P with the gun 23 will be described separately in the case of two strips and the case of one strip in the description of the inspection step 4.

  The drying step 3 is a step of drying the electrode paste P applied on the strip-shaped metal foil L in the applying step 2 and removing the solvent in the electrode paste P. The drying process 3 includes a drying furnace 30. In the drying furnace 30, heating means are arranged along the path of the strip-shaped gold billion night L guided by the auxiliary roll 7. The metal foil L coated with the electrode paste P is heated while passing through the drying furnace 30, the solvent in the electrode paste P is removed, and an active material layer is formed on the metal foil L.

  The inspection step 4 is a step of analyzing elements (particularly silicon and carbon) contained in the electrode paste P (active material layer). The inspection process 4 is arranged immediately after the drying process 3 and includes an analysis unit 4B. The inspection application unit 4A is an application unit that also applies the electrode paste P for inspection (for analysis) when the electrode paste P for electrode in the application step 2 is being applied. In the inspection application means 4A, when the metal foil L unwound from the unwinding roll 5 is supported by the application roll 24, the inspection electrode paste P is applied on the metal foil L from the gun 23 onto the metal foil L. Apply to. The location where the inspection electrode paste P is applied is a location other than the portion of the strip-shaped metal foil L that is cut off as an electrode. Since the portion other than the portion cut out as this electrode is not used as an electrode (since it is usually discarded), it can be effectively used for inspection.

  With reference to FIG. 2, the coating method for electrodes and inspection by the gun 23 in the case of two strips will be described. 2A and 2B are diagrams showing the application state of the electrode paste in the case of two strips, where FIG. 2A shows the case where the electrode paste for inspection is not applied, and FIG. 2B shows the case where the electrode paste for inspection is applied. This is the case. In FIGS. 2 and 3, a portion cut as an electrode is shown by a broken line, and a portion to which an electrode paste is applied is shown by hatching.

Conventionally, when two electrodes are manufactured in the width direction in the strip-shaped metal foil L, as shown in FIG. 2 (a), the electrodes for the two electrodes are formed on the strip-shaped metal foil L (with the width W). Paste P ₁ (with width A) is continuously applied to form active material layers S and S having a width A / 2 corresponding to two electrodes in the width direction of the metal foil L. In the width B (= (W−A) / 2) portion of each end in the width direction of the metal foil L, the electrode paste is not applied, and a part thereof becomes the tab T of each electrode. Except for the electrode tab T at the width B at each end, the portion is cut off.

In the inspection for coating unit 4A, as shown in FIG. 2 (b), while continuous application of the electrode paste P ₁ of the two electrodes (SiO negative electrode) content in a strip of metal foil L, the width direction of the metal foil L the electrode paste P ₂ for inspection locations that do not tab T in the portion of the width B of each end intermittently applied respectively. The shape of the electrode paste P ₂ for inspection may be a circular shape as shown in FIG. 2 (b), may be other shapes. The size of the electrode paste P ₂ for inspection, within which it is possible to analyze in Kant back, may be set as appropriate. Intervals electrode paste P ₂ is intermittently applied for inspection may be set as appropriate.

Nozzle 23b of cancer 23, a main nozzle for an electrode for applying an electrode paste P ₁ of the width A of the two electrode length, and the sub nozzle two inspection issued from both sides of the main nozzle Consists of. The discharge port of the main nozzle is arranged so that the center position thereof coincides with the center line of the metal foil L. The discharge port of each sub nozzle is arranged so that the center position thereof coincides with the center line of the width B portion of each end in the width direction of the metal foil L. Each the secondary nozzle valve is provided for intermittently applying an electrode paste P ₂ for inspection, the valve is momentarily opened and electrode paste from the secondary nozzle at a predetermined intermittent interval is applied. The main nozzle is not provided with a valve, and the electrode paste is continuously applied from the main nozzle. In this two-stripe embodiment, the sub nozzle for inspection corresponds to the inspection applying means described in the claims.

In the case of two strips, two different electrodes are formed in the width direction of the metal foil L. Therefore, each substance (active material, conductive assistant, etc.) contained in the electrode paste in the width direction than in the case of one strip. Must be uniformly dispersed. Therefore, an inspection electrode paste P is provided at both ends of the metal foil L in the width direction so that the dispersion state of the electrode paste (ratio of the active material and the conductive additive) can be analyzed at both ends in the width direction of the metal foil L. _2, has been coated with a _{P 2.} In the electrode paste, substances having different specific gravities are mixed, and substances that cause aggregation with the passage of time are also included. Therefore, even if the material is once sufficiently dispersed in the container 20 of the kneading process, The dispersed state may not be uniform, and the deviation of each substance may occur.

  With reference to FIG. 3, the coating method for the electrodes and the inspection by the gun 23 in the case of a single strip will be described. 3A and 3B are diagrams showing the application state of the electrode paste in the case of one strip, where FIG. 3A shows the case where the inspection electrode paste is not applied, and FIG. 3B shows the case where the inspection electrode paste is applied. This is the case.

Conventionally, when one electrode is manufactured in the width direction in the strip-shaped metal foil L, as shown in FIG. 3 (a), an electrode corresponding to one electrode is formed on the strip-shaped metal foil L (the width is W). Paste P ₃ (with a width C) is intermittently applied to form an active material layer S having a width D corresponding to one electrode in the width direction of the metal foil L. Width C which is the electrode paste P ₃ is applied is slightly wider than the width D of the active material layer S of the electrode. In the width E (= (WC) / 2) portion of each end in the width direction of the metal foil L, the electrode paste is not applied and the tab T is not used. The part of each end having a width E is a part to be cut off. Incidentally, the tab T, the electrode paste intermittent application is formed at a portion between the electrode paste P ₃ and the electrode paste P ₃ which is not coated.

In the inspection application means 4A, as shown in FIG. 3B, when the electrode paste for one electrode (SiO negative electrode) is intermittently applied to the strip-shaped metal foil L, an electrode having a width F wider than the width C. the paste _{P 4} to intermittent application. The electrode paste P ₄ having the width F is wider than the conventional electrode paste P _{3 having} the width C for an electrode by an amount of (F−C) in the width E portion at one end in the width direction of the metal foil L. It is a thing. Portion of the width of the end portion of the electrode paste P ₄ (F-C) becomes an electrode paste for inspection. The width of (FC) may be set as appropriate within the range where analysis by cant back is possible.

Nozzle 23b of cancer 23, only the main nozzle (electrode + inspection) for applying an electrode paste P ₄ of width F. The discharge port of the main nozzle is arranged with its center position deviated from the center line of the metal foil L by (FC) / 2. Valve to the main nozzle for intermittently applying an electrode paste P ₄ is provided, the electrode paste is applied the valve is opened a predetermined time at a predetermined intermittent intervals. The valve opening / closing control of the gun 23 is performed by the control device of the production line 1. In this one-stripe embodiment, the main nozzle also serves as the inspection application means described in the claims.

  In the case of one strip, only one electrode is provided in the width direction of the metal foil L, so that the accuracy of the dispersion state of each substance contained in the electrode paste is not required in the width direction compared to the case of two strips. Therefore, the electrode paste having the inspection width (FC) is applied only to one end in the width direction of the metal foil L. In the case of a single strip, an electrode paste having an inspection width (FC) may be applied to both ends of the metal foil L in the width direction. Also, in the case of single striping, the electrode paste for normal electrodes is spread and applied for inspection, so that for electrode strips (continuous coating) and for inspection (intermittent coating) as in the case of double striping There is no need to apply the electrode paste separately. Therefore, in the case of a single strip, application of a comma roll method other than the die method is also applicable.

The analysis means 4B is a means for analyzing elements (particularly carbon (C) and silicon (Si)) contained in the inspection electrode paste applied by the inspection application means 4A. Therefore, the cant bag 40 is disposed as the analyzing means 4B immediately after the drying step 3 (step where the electrode paste is dried and the solvent is removed). In the cant back 40, when a portion where the inspection electrode paste is applied passes through the metal foil L being transported, a spark discharge occurs on the inspection electrode paste, and the elements contained in the electrode paste are discharged. Perform qualitative and quantitative analysis. At this time, the metal foil L being conveyed may be temporarily stopped. In the cant bag 40, the content of each element contained in the electrode paste (at least the carbon content and the silicon content) is detected. Further, in the cant bag 40, the ratio of carbon and silicon contained in the electrode paste is calculated from the carbon content and the silicon content. In the cant back 40, in the case of two strips, analysis is performed on the electrode pastes P ₂ and P ₂ for inspection at both ends in the width direction of the metal foil L. In the case of one strip, the electrode paste P is analyzed. _The analysis is performed on the electrode paste for inspection of (FC) at one end in the width direction of the metal foil L in FIG. In the case of a single strip, since the electrode paste for inspection (FC) is applied to each electrode, it is not necessary to analyze all of the electrode paste for inspection, and every predetermined number of electrodes. You can analyze it.

  With reference to FIG. 1, the effect | action of the application | coating process 2, the drying process 3, and the test | inspection process 4 in the manufacturing line 1 of the said structure is demonstrated.

  When the unwinding roll 5 and the winding roll 6 are operated, the metal foil L is sent out from the unwinding roll 5, and the metal foil L is conveyed between the unwinding roll 5 and the winding roll 6 at a predetermined conveying speed. When the metal foil L starts to move, the operations in the application process 2, the drying process 3 and the inspection process 4 are also started.

In the application process 2, the pump 22 is operated to supply the electrode paste P from the container 20 to the gun 23 via the supply pipe 21. In the gun 23, the electrode paste P temporarily accumulates in the manifold 23a, pushes the electrode paste P from the manifold 23a to the nozzle 23b, and applies the electrode paste P onto the metal foil L supported by the application roll 24 from the nozzle 23b. In this case, the coating step, (see FIG. 2 (b)) in the case of Article 2 up continuously applying an electrode paste P _1, the electrode paste P ₄ intermittently applied in the case of Article 1 up (FIG. 3 (b )reference). Further, in the inspection coating process of the inspection process, in the case of two strips, the inspection electrode pastes P ₂ and P ₂ are intermittently applied to both ends in the width direction of the metal foil L (see FIG. 2B). intermittently applying an electrode paste P ₄ for inspection of electrode integral with one end portion in the width direction of the metal foil L in the case of Article 1 up (see Figure 3 (b)).

  In the drying step 3, when the metal foil L coated with the electrode paste is placed in the drying furnace 30, the heating means disposed in the drying furnace 30 heats the electrode paste, evaporates the solvent in the electrode paste, The paste dries.

In the inspection step 4, when the electrode paste for inspection after drying on the metal foil L is conveyed to the cant back 40, the cant back 40 performs a spark discharge to analyze the elements contained in the electrode paste. At this time, the cant back 40 detects the content of each element contained in the electrode paste (particularly, the carbon content and the silicon content), and calculates the ratio of carbon to silicon contained in the electrode paste. In the case of two strips, analysis is performed on the inspection electrode pastes P ₂ and P ₂ at both ends in the width direction of the metal foil L, and in the case of one strip, the inspection is performed on the electrode paste P ₄ . Analysis is performed on the electrode paste portion. In the cant bag 40, the analysis results (content of each element, ratio of carbon and silicon, etc.) are output to a control device that controls the stirring means and the charging means in the kneading process.

  In the control device, when the analysis result is input, the ratio of the active material and the conductive additive is calculated from the ratio of carbon and silicon, and whether or not the ratio of the actual active material and the conductive additive is an appropriate ratio. Determine. If it is not an appropriate ratio, the state of dispersion of each substance in the electrode paste may be deteriorated. Therefore, in the control device, the drive condition (kneading condition) of the stirring means is changed so that the appropriate ratio is obtained. .

  According to the electrode inspection apparatus in this production line 1, a means for applying an electrode paste for inspection to a portion other than a portion cut out as an electrode in the strip-shaped metal foil L is provided, and the metal foil L is used as an analysis means. The active material layer on the metal foil L can be inspected before being assembled as a battery by performing an emission spectroscopic analysis on the electrode paste for inspection applied thereon with the cant back 40. Moreover, accurate breakdown analysis can be used in the production line 1 by using a portion that is not used as an electrode.

  In addition, since the output method of the inspection device in the manufacturing line 1 is a manufacturing method that reflects the kneading process, the ratio of the active material and the conductive additive included in the electrode paste is grasped in real time and included in the electrode paste being manufactured. The ratio between the active material and the conductive auxiliary agent can be quickly reflected in the electrode paste kneading step. As a result, the ratio between the active material and the conductive additive contained in the active material layer can be adjusted quickly and appropriately.

  Moreover, according to the electrode inspection in the production line 1, the electrode to be inspected is a SiO negative electrode, and the cant back 40 excellent in the analysis of silicon (Si) and carbon (C) is used as an emission spectroscopic analysis. The ratio of silicon and carbon contained in the paste can be detected with high accuracy. As a result, the ratio between the active material and the conductive additive contained in the SiO negative electrode paste can be detected with high accuracy, and the ratio between the active material and the conductive additive contained in the SiO negative electrode paste can be adjusted quickly and appropriately. it can.

  Further, according to the electrode inspection in the production line 1, in the case of two strips, the electrode paste is applied to both ends in the width direction of the metal foil L, and cant back is applied to the electrode paste for inspection at both ends. By performing emission spectroscopic analysis at 40, it is possible to grasp the dispersion state (whether uniform or varied) of the electrode paste active material and the conductive additive in the width direction. As a result, it is possible to prevent the active material and the conductive additive from being dispersed differently in the two electrodes that differ in the width direction in the two strips, and it is possible to manufacture an electrode having the same quality.

  An SiO negative electrode produced using an electrode paste having an appropriate (proper) ratio between the active material and the conductive additive has a high quality of the active material layer and a high quality as an electrode. As a result, the performance as the SiO negative electrode can be sufficiently exhibited, and it can be prevented as much as possible from becoming a defective product after production. Further, by manufacturing a power storage device using the high-quality SiO negative electrode, the power storage device becomes a high-performance battery with high output and long life. Such a power storage device is suitable for a vehicle that is required to have a high output and a long life, and is typically mounted on an automobile (particularly, an automobile equipped with an electric motor such as a hybrid vehicle, an electric vehicle, and a fuel cell vehicle). It is suitable as a battery to be used.

  As mentioned above, although embodiment which concerns on this invention was described, this invention is implemented in various forms, without being limited to the said embodiment.

  For example, in this embodiment, the present invention is applied to a SiO negative electrode in which the active material is silicon oxide and the conductive assistant is a carbon-based substance. As long as it is composed of a substance composed of different element components as an auxiliary agent, it can be applied to negative electrodes having other constitutions. For example, a carbon-based substance is applied as an active material and a non-carbon-based substance is applied as a conductive auxiliary agent. It can also be applied to the positive electrode.

  Further, in this embodiment, the spark discharge cantback is applied as the emission spectroscopic analysis apparatus, but other emission spectroscopic analysis apparatuses such as arc discharge may be used.

  In this embodiment, the inspection electrode paste is applied to the end of the strip-shaped metal foil in the width direction. However, in the case of one strip, the intermediate portion in the width direction is also used as an electrode electrode by intermittent application. Since there is a portion where the paste is not applied, an inspection electrode paste may be applied to the intermediate portion in the width direction.

  Further, in the present embodiment, the emission spectroscopic analysis is performed in a state where the electrode paste for inspection is applied on the metal foil in the middle of conveyance, but after the end in the width direction is cut from the metal foil, An emission spectroscopic analysis may be performed on the electrode paste for inspection applied to the end after being cut off.

  In this embodiment, the driving conditions of the stirring means in the kneading process are changed based on the result of the emission spectroscopic analysis. However, the conditions of the charging means of each substance may be changed. In the result of emission spectroscopic analysis, when there is a uniform bias in the detection results of a plurality of times, or when there is a uniform bias in the detection location of the strip-shaped metal foil, the mixing ratio of each substance into the container 20 However, it is possible that the value is not appropriate. In this case, it is effective to control the input means and change the input amount of each substance.

  In this embodiment, the inspection process is arranged immediately after the drying process. However, a roll press may be arranged between the drying process and the inspection process.

  In this embodiment, the electrode paste for inspection is applied in the application step of applying the electrode paste for the electrode, and the application step also serves as the inspection application step. However, the present invention is particularly limited to this embodiment. is not. For example, an inspection application process for applying an inspection electrode paste may be separately provided between the application process and the drying process.

  DESCRIPTION OF SYMBOLS 1 ... Manufacturing line, 2 ... Application | coating process, 3 ... Drying process, 4 ... Inspection process, 4A ... Application | coating means for inspection, 4B ... Analyzing means, 5 ... Unwinding roll, 6 ... Winding roll, 7 ... Auxiliary roll, 20 DESCRIPTION OF SYMBOLS ... Container, 20a ... Stirrer blade, 20b ... Input port, 21 ... Supply pipe, 22 ... Pump, 23 ... Gun, 23a ... Manifold, 23b ... Nozzle, 24 ... Coating roll, 30 ... Drying furnace, 40 ... Cant back.

Claims (5)

An electrode manufacturing method for forming an active material layer by applying an electrode paste to a metal foil,
An inspection application process for applying an inspection electrode paste to a portion other than a portion cut as an electrode on a strip-shaped metal foil;
An analysis step of analyzing the electrode paste applied in the inspection application step by emission spectral analysis;
The manufacturing method of the electrode characterized by including.   2. The method for producing an electrode according to claim 1, wherein the result of analysis in the analysis step is reflected in the kneading conditions of the electrode paste. The electrode to be inspected is a negative electrode,
The method for producing an electrode according to claim 1, wherein the electrode paste for the negative electrode includes at least a silicon oxide active material and a conductive additive containing carbon.   The electrode for inspection according to any one of claims 1 to 3, wherein in the inspection application step, an inspection electrode paste is applied to both end portions in the width direction of the strip-shaped metal foil. Production method. An electrode inspection apparatus in which an active material layer is formed by applying an electrode paste to a metal foil,
An inspection application means for applying an inspection electrode paste to a portion other than a portion cut as an electrode on a band-shaped metal foil,
Analysis means for analyzing the electrode paste applied by the inspection application means by emission spectral analysis;
An electrode inspection apparatus comprising:

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