KR101348020B1 - Foreign material detecting device and foreign material detecting method - Google Patents

Abstract

The foreign matter detection device 10 is a device that detects the foreign matter Z on the strip-shaped metal foil 20. This foreign matter detection apparatus 10 is a metal foil 20 with respect to the conveying apparatus 120 which conveys the metal foil 20 along the curved conveyance path 12, and the part W where the metal foil 20 is bent and conveyed. It is arrange | positioned at one side of this conveyance direction, and it is a metal foil (with respect to the X-ray irradiator 14 which irradiates the X-ray 30 along the conveyance path 12, and the part W in which the metal foil 20 is bent and conveyed). It is arrange | positioned at the other side of the direction to which 20 is conveyed, and the X-ray detector 16 which detects the X-ray 30 irradiated from the X-ray irradiator 14 is provided.

Description

Foreign substance detection device and foreign substance detection method {FOREIGN MATERIAL DETECTING DEVICE AND FOREIGN MATERIAL DETECTING METHOD}

The present invention relates to a foreign matter detection device and a foreign matter detection method for detecting a foreign matter on a metal foil (including foreign matter contained in an electrode material applied to a metal foil).

For example, Japanese Patent Application Laid-Open No. 2006-179424 discloses a method of inspecting during the manufacturing process whether metal impurity particles present in an electrode substrate can cause a short circuit in a battery. In this publication, for example, a band-shaped electrode substrate made of expanded nickel is irradiated with X-rays (X-rays) to obtain a transmission image. Based on the transmission phase, metal impurity particles are detected. have.

In addition, Japanese Patent Application Laid-Open No. 2008-210784 discloses a method of measuring the deposition amount of silicon or silicon compound per unit area of a current collector. In this method, X-rays are irradiated to the active material layer on the current collector to receive fluorescent X-rays generated from the active material layer.

Japanese Patent Application Publication No. 2006-179424 Japanese Patent Application Publication No. 2008-210784

By the way, when manufacturing a battery, the electrode body may be comprised by laminating a sheet-shaped electrode sheet which apply | coated the electrode material of a paste state to the electrical power collector which consists of metal foils through a separator. In this case, if foreign matter is mixed in the electrode body, foreign matters are precipitated when the battery is charged or discharged, thereby causing a problem. In order to prevent such a problem, it is preferable that foreign substances are not mixed in the battery.

When X-rays are irradiated to penetrate the metal foil, the X-rays are attenuated by the metal foil. For this reason, in order to detect the foreign material which exists on metal foil based on the X-ray which permeate | transmitted metal foil, X-ray of strong intensity | strength is needed. In addition, since the strong X-rays have a weak spatial resolution, it is difficult to detect minute foreign matters. In addition, foreign substances made of light metal have a weaker effect of attenuating X-rays than metal foil. For this reason, when a foreign material which consists of a light metal exists on a metal foil, a foreign material may not be detected.

Accordingly, the present invention provides a foreign matter detection apparatus and a foreign matter detection method suitable for detecting foreign matter on a metal foil (including foreign matter contained in an electrode material applied to a metal foil).

The foreign substance detection apparatus which concerns on this invention is an apparatus which detects the foreign substance on a strip | belt-shaped metal foil, and the conveying apparatus which conveys a metal foil along the curved conveyance path | route, and one side of the direction in which metal foil is conveyed with respect to the part conveyed by metal foil. The X-ray irradiator which is arranged in the X-ray irradiator along the conveyance path | route, and the metal foil is bent and conveyed, is arrange | positioned in the other direction of the direction where the said metal foil is conveyed, and detects the X-ray irradiated from the said X-ray irradiator An X-ray detector is provided.

According to such a foreign matter detection apparatus, foreign matter can be detected by observing X-rays transmitted through the electrode material without passing the metal foil. For this reason, the intensity | strength of X-rays can be weakened, a spatial resolution can be made high, and a smaller foreign material can be detected.

In this case, the foreign matter detection device may be provided with a determination unit that determines the presence or absence of the foreign matter based on the X-ray detection data detected by the X-ray detector. In addition, the X-ray detection data detected by the X-ray detector may include a normal value storage unit that stores normal detection data obtained in a state where no foreign matter is present on the metal foil. In this case, the determining unit may determine the presence or absence of the foreign matter based on the X-ray detection data detected by the X-ray detector and the normal detection data stored in the normal value storage unit.

In addition, the foreign matter detection device may be provided with an X-ray visualization device that generates image data based on the X-ray detection data detected by the X-ray detector. In this case, with respect to the image data acquired by the X-ray visualization apparatus, a normal value storage section storing normal image data obtained in a state where no foreign matter is present on the metal foil, and image data acquired by the X-ray visualization apparatus; And a difference processing unit for obtaining difference data of normal image data stored in the normal value storage unit. Moreover, you may be provided with the determination part which determines the presence or absence of a foreign material based on the difference data obtained by the difference processing part.

In addition, the foreign matter detection device may be provided with a radiation shielding box that partitions an area where X-rays are irradiated from the X-ray irradiator with respect to a portion where the metal foil is bent and conveyed by the conveying device. In this case, the shielding plate may be disposed along the conveyance path of the metal foil at the inlet or the outlet of the radiation shielding box.

In addition, the conveying apparatus may have a 1st part which bends and conveys the one side surface of metal foil toward an outer side in the conveyance path | route of metal foil, and a 2nd part which bends and conveys the surface on the opposite side of metal foil toward an outer side. In this case, what is necessary is just to arrange | position an X-ray irradiator and an X-ray detector with respect to both of a 1st part and a 2nd part, respectively. Thereby, both surfaces of the metal foil can be inspected.

Moreover, the conveying apparatus may have the curved part which conveys, bending a metal foil. In this case, the X-ray irradiator may be disposed on one side of the tangent of the curved portion, and the X-ray detector may be disposed on the other side of the tangent. In this case, the tangent may be set so as to pass through the top of the curved portion where the metal foil is bent and conveyed in the conveyance path of the metal foil. In addition, the conveying apparatus may be provided with the roller which guides a metal foil in a curved part. In addition, the foreign matter detection device may include a control unit for controlling the intensity of X-rays irradiated by the X-ray irradiator.

1 is a diagram illustrating a foreign matter detection device according to a first embodiment of the present invention.
It is a figure which shows the electrode material application | coating installation apparatus which has a foreign matter detection apparatus which concerns on 1st Embodiment of this invention.
It is a figure which shows the X-ray image obtained by the foreign material detection apparatus which concerns on 1st Embodiment of this invention.
It is a figure which shows the X-ray image obtained by the foreign material detection apparatus which concerns on 1st Embodiment of this invention.
It is a figure which shows the X-ray difference processing obtained by the foreign material detection apparatus which concerns on 1st Embodiment of this invention.
It is a figure which shows the foreign material detection apparatus which concerns on 1st Embodiment of this invention.
It is a figure which shows the foreign matter detection apparatus which concerns on other embodiment of this invention.
It is a figure which shows the foreign matter detection apparatus which concerns on other embodiment of this invention.
It is a figure which shows the foreign matter detection apparatus which concerns on other embodiment of this invention.
It is a figure which shows the structural example of a battery.
It is a figure which shows the structural example of a wound electrode body.
It is a figure which shows the structural example of a wound electrode body.
It is a figure which shows an example of the vehicle in which the battery was mounted.

The foreign matter detection apparatus and the foreign matter detection method according to the first embodiment of the present invention are described above. In addition, in another embodiment, the same code | symbol is attached | subjected to the member and site | part which exhibit the same effect | action.

1 is a schematic diagram showing the foreign matter detection apparatus 10. The foreign matter detection apparatus 10 detects foreign matter Z on the metal foil 20 (including foreign matter contained in the electrode material coated on the metal foil 20). As shown in FIG. 1, this foreign matter detection device 10 includes a transport device 120 for transporting the metal foil 20, an X-ray irradiator 14, and an X-ray detector 16. In this embodiment, the metal foil 20 which is metal foil used for the electrical power collector of a battery, and the electrode material 20a was apply | coated was made into the test object. In addition, in this embodiment, as shown in FIG. 2, the foreign substance detection apparatus 10 is built in the electrode material application | coating apparatus 100 which apply | coats the electrode material 20a to the metal foil 20. As shown in FIG. FIG. 2 illustrates an electrode material coating device 100 for coating the electrode material 20a on the metal foil 20.

The metal foil 20 is used as an electrical power collector of a battery, for example. In a lithium-ion secondary battery, aluminum foil, copper foil, or the like is used as the current collector of the battery. Aluminum foil is mainly used as an electrical power collector of a positive electrode, and copper foil is mainly used as an electrical power collector of a negative electrode.

In lithium-ion secondary batteries, for example, lithium manganate (LiMn ₂ O ₄ ), lithium cobalt (LiCoO ₂ ), lithium nickelate (LiNiO ₂ ), or the like as a positive electrode active material. Is being used. As the negative electrode active material, for example, a carbon-based material such as graphite or amorphous carbon, a lithium-containing transition metal oxide, a transition metal nitride, or the like is used. The positive electrode active material and the negative electrode active material are mixed with a solvent, a binder, a conductive material and the like in a paste state. And it is apply | coated to the metal foil 20 as a collector. In addition, the structural example of the battery which used the metal foil 20 as an electrical power collector is explained in full detail later.

In this embodiment, the metal foil 20 may have a site | part in which the electrode material 20a is not apply | coated (henceforth a said site | part is called an "unpainted part") (refer FIG. 11). This foreign matter detection apparatus 10 is, for example, foreign matter included in the electrode material 20a, foreign matter attached to an uncoated construction part, and electrode with respect to the metal foil 20 to which such electrode material 20a is applied. A foreign matter or the like adhering to the surface of the material 20a can be detected. The foreign material detection device 10 may be disposed, for example, in a subsequent step of the device for applying the electrode material 20a to the metal foil 20.

As shown in FIG. 2, the electrode material coating apparatus 100 includes the feeding unit 101, the coating unit 102, the drying unit 103, the winding unit 104, and the transfer control unit 105. ). The feeding part 101 is a site | part where the metal foil 20 wound up in roll shape is set, and the said metal foil 20 is fed out. The application part 102 is a site | part which apply | coats the electrode material 20a of a paste state to the metal foil 20. FIG. In the example shown in FIG. 2, the application part 102 opposes the back roll 112 which guides the back surface of the metal foil 20 conveyed, and the back roll 112, and pastes on the surface of the metal foil 20. The application head 114 which apply | coats the electrode material 20a of a state is provided.

The drying part 103 is a site | part which dries the electrode material 20a of the paste state apply | coated and applied to the metal foil 20 by the application part 102. FIG. The winding-up part 104 is a site | part in which the metal foil 20 to which the electrode material 20a was apply | coated was wound up in roll shape. As shown in FIG. 2, the metal foil 20 extracted from the feeding unit 101 is guided to the plurality of guide rolls 106, and the coating unit 102 and the drying unit 103 are removed from the feeding unit 101. The predetermined conveyance path 12 which passes through in order, and reaches the winding-up part 104 is formed. The conveyance control part 105 controls the rotation of the drawing | feeding-out part 101 and the winding-up part 104, and conveys the metal foil 20 along the predetermined | prescribed conveyance path 12. As shown in FIG. In this way, the electrode material coating device 100 includes a conveying device 120 for conveying the metal foil 20 along a predetermined path.

In this embodiment, the foreign substance detection apparatus 10 is arrange | positioned at the post process of the coating apparatus which apply | coats the electrode material 20a to the metal foil 20. As shown in FIG. That is, in this embodiment, the electrode material 20a is apply | coated to the metal foil 20, it is arrange | positioned at the process after drying, and the drying part 103 of the conveyance path | route 12 of the electrode material application-coating apparatus 100 is carried out. ) And the winding-up part 104.

In addition, although illustration is abbreviate | omitted, the electrode material coating apparatus 100 should just be equipped with the well-known means of conveying the metal foil 20 with high precision. For example, the position detection device which detects the position of the width direction of the metal foil 20, the correction device which correct | amends the shift | deviation of the width direction of the metal foil 20, or the tension adjustment device which applies an appropriate tension to the metal foil 20, for example. What is necessary is just to provide various apparatuses, such as these in the conveyance path | route 12. Thereby, the metal foil 20 supplied to the application part 102, the drying part 103, and the foreign material detection apparatus 10 can be conveyed with high precision.

Hereinafter, the foreign matter detection device 10 will be described in more detail. In the foreign substance detection apparatus 10, as shown in FIG. 1, the conveyance path | route of the metal foil 20 is bent. In this embodiment, the roller 22 which guides the metal foil 20 is arrange | positioned, and the metal foil 20 is guided by the roller 22, and is conveyed, bending at predetermined curvature.

In this embodiment, as shown in FIG. 1, the electrode material 20a is apply | coated to the single side | surface of the metal foil 20. FIG. When detecting the foreign matter contained in such an electrode material 20a, as shown in FIG. 1, when the metal foil 20 hangs on the roller 22 toward the outside on the surface by which the electrode material 20a was apply | coated, do.

The X-ray irradiator 14 is disposed at one side of the direction in which the metal foil 20 is conveyed with respect to the portion W where the metal foil 20 is bent and conveyed, and the X-ray 30 is moved along the conveyance path 12. Investigate. In this embodiment, the X-ray irradiator 14 is tangent from one side of the tangent L of the conveyance path 12 with respect to the curved part W in which the metal foil 20 was bent in the conveyance path 12. It is arrange | positioned so that X-ray may be irradiated to metal foil along (L). In addition, in this embodiment, the X-ray irradiator 14 irradiates the X-ray 30 so that the metal foil 20 may be irradiated to the metal foil 20 along the tangent L from the upstream side of the conveyance path 12. The site | part to irradiate is arrange | positioned toward the curved part W.

Moreover, in this embodiment, the X-ray irradiator 14 is equipped with the control part 14a which controls the intensity | strength of the X-ray to irradiate. Thereby, the intensity | strength suitable for detecting the foreign material Z on the metal foil 20 (in the example shown in FIG. 1, containing the foreign material Z contained in the electrode material 20a apply | coated to the metal foil 20). X-rays 30 can be controlled. For example, what is necessary is just to control the intensity | strength of the X-ray to irradiate according to the apply | coated electrode material 20a and the foreign material Z used as a detection object. The intensity of X-rays can be controlled by manipulating a voltage that generates X-rays, for example. Such an X-ray irradiator 14 preferably has an X-ray source of low tube voltage and high tube current with a smaller focal dimension. As such X-ray irradiator 14, what has a function required by a commercial X-ray irradiator may be employ | adopted, for example.

Next, the X-ray detector 16 is arrange | positioned at the other side of the direction in which the metal foil 20 is conveyed with respect to the part W where the metal foil 20 is bent and conveyed. The X-ray detector 16 detects X-rays irradiated from the X-ray irradiator 14. This X-ray detector 16 is arrange | positioned on the opposite side to the X-ray irradiator 14 in the tangent L of the curved part W of the conveyance path | route 12. As shown in FIG. In addition, in this embodiment, the X-ray detector 16 is arrange | positioned downstream of the conveyance path 12 with respect to the curved part W in which the metal foil 20 was bent in the conveyance path 12.

In this embodiment, the X-ray detector 16 has an X-ray visualization device 16a that generates image data obtained by converting an X-ray image into a visible light image. A so-called "X-ray image intensifier" can be used for such an X-ray visualization apparatus 16a. The X-ray visualizing device 16a may employ a device having a necessary function for high sensitivity, high pixel number, aspect ratio suitable for visualization, and the like.

In addition, in this embodiment, the tangential line L is set so that the metal foil 20 may pass through the top part T of the curved part W by which the metal foil 20 is bent and conveyed among the conveyance paths 12 of the metal foil 20. . And the X-ray irradiator 14 is arrange | positioned at one side of this tangent L, and the X-ray detector 16 is arrange | positioned at the other side of this tangent L. As shown in FIG. In addition, in this embodiment, the X-ray irradiator 14 is arrange | positioned at the upstream of the conveyance path 12, and the X-ray detector 16 is arrange | positioned at the downstream side of the conveyance path 12. As shown in FIG.

According to such a foreign matter detection apparatus 10, the X-ray 30 is irradiated from the X-ray irradiator 14, conveying the metal foil 20 along the conveyance path 12. As shown in FIG. The X-rays 30 are irradiated from one of the tangent lines L to the curved portion W in which the conveyance path of the metal foil 20 is curved. And the X-ray 30 irradiated to the metal foil 20 is observed by the X-ray detector 16 arrange | positioned at the other side of the said tangent L. As shown in FIG. In this embodiment, the X-ray detector 16 generates image data obtained by converting an X-ray image into a visible light image.

In this embodiment, X-rays are irradiated to the metal foil along the tangent line from one side of the tangent of the curved transfer route while conveying along the curved path of the strip-shaped metal foil 20, and on the other side of the tangent line. X-rays are observed. In this case, X-rays transmitted through the electrode material 20a can be observed without passing through the metal foil 20. That is, as shown in FIG. 3, the X-ray image observed by the X-ray detector 16 has the site | part a1 where the X-ray 30 is interrupted | blocked by the metal foil 20, and the X-ray 30 is The site | part a2 which permeate | transmits the electrode material 20a, and the site | part a3 which the X-ray 30 does not permeate | transmit the metal foil 20 and the electrode material 20a are included.

At this time, a dark shadow occurs in the portion a1 where the X-ray 30 is blocked by the metal foil 20. On the other hand, in the site | part a2 which permeate | transmits the electrode material 20a, a shadow becomes dim compared with the site | part a1 which the X-ray 30 is interrupted by the metal foil 20. FIG. In addition, in the portion a3 where the X-rays 30 do not penetrate the metal foil 20 and the electrode material 20a, the X-rays 30 are not attenuated and almost no shadows are generated. In the electrode material 20a, an active material (positive electrode active material or negative electrode active material), a solvent, a binder, a conductive material, and the like are mixed and applied in a paste state and dried. For this reason, the electrode material 20a has a low effect of attenuating the X-ray 30 compared with the metal foil 20, and the site | part a2 which permeate | transmits the electrode material 20a is X-ray by metal foil 20 It is thought that the shadow becomes blurry compared with the site | part a1 where (30) is blocked.

In the portion a2 through which the X-ray 30 penetrates the electrode material 20a, the component ratio of the active material (positive electrode active material or negative electrode active material), the solvent, the binder, and the conductive material included in the electrode material 20a By the degree of the mixed state, the shadow density is determined, and the shadow of a substantially constant density is generated. The portion a2 that penetrates the electrode material 20a and the portion a1 where the X-ray 30 is blocked by the metal foil 20 are markedly different in the density of shadows generated and can be easily identified. .

In addition, when the foreign material Z is contained in the electrode material 20a, as shown in FIG. 4, the shadow resulting from the foreign material Z is observed in the shadow resulting from the electrode material 20a. In particular, in the case of a metallic foreign material which is likely to attenuate the X-rays 30, a shadow darker than the electrode material 20a is likely to occur.

As illustrated in FIG. 1, the foreign matter detection device 10 is configured to convey the strip-shaped metal foil 20 along the bent conveyance path 12. And the X-ray 30 is irradiated along the conveyance path 12 with respect to the said bent conveyance path 12, and the foreign material on the metal foil 20 based on the X-ray 30 observed from the other side ( Z) (containing foreign matter Z included in the electrode material 20a coated on the metal foil 20) is detected. According to this foreign matter detection apparatus 10, the foreign matter Z can be detected by observing the X-ray 30 which permeate | transmitted the electrode material 20a, without passing the metal foil 20 as mentioned above. For this reason, even if the intensity | strength of the X-ray 30 is made weak, the foreign material Z can be detected. In addition, since X-rays with low intensity have high spatial resolution, smaller foreign substances Z can be detected. Moreover, since X-ray which permeate | transmitted the electrode material 20a can be observed, without passing through the metal foil 20, foreign matter with a small effect which attenuates X-ray 30 like a hard metal can also be detected.

In addition, in this embodiment, the metal foil 20 is bent and conveyed in part. And the X-ray irradiator 14 is arrange | positioned at one side and the X-ray detector 16 is arrange | positioned at the other with respect to the tangent line L set so that the top part T of the curved part W may pass. In this case, the range where the X-ray which permeate | transmitted the electrode material 20a by the X-ray detector 16 among the conveyance path | route 12 of the metal foil 20 is observed is narrow. For this reason, when it is suspected that foreign matter Z exists on the metal foil 20 based on the X-ray 30 observed by the X-ray detector 16, the foreign matter Z at any position of the metal foil 20. This may be specified in a narrower range. Thereby, for example, when removing the part in which the foreign material Z exists from the metal foil 20 and assembling a battery, since the range to remove can be made small, a yield can be improved.

In addition, by changing the radius of curvature of the curved portion W in which the metal foil 20 is curved and conveyed, the X-ray detector 16 transmits the electrode material 20a in the conveying path 12 of the metal foil 20. The range over which one X-ray is observed can be adjusted to any length.

In the foreign matter detection apparatus 10, the X-ray detector 16 generates image data obtained by converting an X-ray image into a visible light image. Based on such image data, an operator may monitor and determine the X-ray image on the display. However, the X-ray image observed by the X-ray detector 16 may include a shadow caused by the metal foil 20 or a shadow caused by the electrode material 20a, and may be difficult to determine as it is.

In this embodiment, as shown in FIG. 1, the foreign matter detection device 10 determines a presence or absence of the foreign matter Z based on the X-ray detection data detected by the X-ray detector 16. 50 is provided.

This determination unit 50 includes a normal value storage unit 52, a difference processing unit 54, and a determination processing unit 56. Such a determination unit 50 can be realized by, for example, executing a program that is set in advance so as to exert a required function on each computer. In this case, the computer may include, for example, a computing device such as a CPU and a storage device such as a nonvolatile memory, and may have a function capable of processing a required operation according to a set program.

The stationary value storage unit 52 stores normal detection data obtained in a state where no foreign matter Z is present on the metal foil 20 with respect to the X-ray detection data detected by the X-ray detector 16. . In this embodiment, the X-ray detector 16 has an X-ray visualization device 16a that generates image data obtained by converting an X-ray image into a visible light image. The normal value storage unit 52 stores normal image data obtained in a state where no foreign matter Z is present on the metal foil 20 with respect to the image data acquired by the X-ray visualization apparatus 16a.

The difference processing unit 54 obtains difference data between the image data acquired by the X-ray visualization apparatus 16a and the normal image data stored in the normal value storage unit 52. 5 schematically illustrates the processing of the difference processing unit 54. The difference processing unit 54 obtains the difference data D3 of the image data D1 acquired by the X-ray visualization apparatus 16a and the normal image data D2 stored in the normal value storage unit 52. In this embodiment, the difference data D3 subtracts the normal image data D2 stored in the normal value storage unit 52 from the image data D1 acquired by the X-ray visualizing apparatus 16a, and debris ( We are extracting shadows due to Z).

In this case, after subtracting the normal image data D2 stored in the normal value storage unit 52 from the image data D1 acquired by the X-ray visualization apparatus 16a, the noise may be removed as necessary. By removing the noise, as shown in FIG. 5, the shadow caused by the foreign matter Z can be extracted more appropriately. Thus, in this embodiment, the difference which acquires the difference data D3 of the image data D1 acquired by the X-ray visualization apparatus 16a, and the normal image data D2 stored in the normal value memory | storage part 52 is obtained. The processing part 54 is provided. Therefore, in the image based on such difference data D3, the shadow resulting from the metal foil 20 or the electrode material 20a is deleted, and the shadow resulting from the rough foreign matter Z remains. For this reason, determination of the presence or absence of the foreign material Z can be performed easily. Such a determination may be made by, for example, illuminating an image based on the difference data D3 on the display device and monitoring the image on the display device by the operator.

In this foreign matter detection apparatus 10, the determination can be further performed using a computer. That is, in this embodiment, the determination processing part 56 determines the presence or absence of the foreign material Z based on the difference data D3 obtained by the difference processing part 54. As shown in FIG. The determination processing part 56 may determine the presence or absence of the foreign material Z, for example based on whether the shadow resulting from the foreign material Z exists in the difference data D3. In this case, for example, whether or not the shadow generated in the difference data D3 obtained by the difference processing unit 54 is actually the shadow caused by the foreign matter Z becomes a problem. In addition, there is also a foreign matter (Z) small enough to not cause a problem even when the battery is assembled. Therefore, the determination processing part 56 may set a certain threshold value with respect to the shadow which generate | occur | produced in the difference data D3, and may judge that there exists a foreign material Z when the said threshold value is exceeded.

For example, the shadow generated in the difference data D3 may be determined to be "there is a foreign material Z" compared to a certain threshold value. For example, when the shadow value suspected to be caused by the foreign matter Z is set in advance, and the shadow suspected to be caused by the foreign matter Z is larger than the threshold value, there is a "foreign matter Z". May be determined. In addition, the shadow smaller than the predetermined size may be removed as noise. As a result, it is possible to ignore the foreign matter Z that is small enough to cause no problem even when the battery is assembled and the shadow caused by the noise. As a result, a more appropriate judgment can be made and the determination error can be eliminated. For example, when it determines with "the foreign material Z" by such determination part 50, it can be made not to use this part for a battery. In this case, by removing the shadows smaller than the predetermined size as noise, it is possible to reduce the unnecessary portions discarded by mistake. Thereby, a yield can be improved.

Moreover, this foreign matter detection apparatus 10 is equipped with the X-ray visualization apparatus 16a, as shown to FIG. 1 and FIG. 5, and the image data D1 acquired by the X-ray visualization apparatus 16a is carried out. Getting. And in the determination part 50, presence or absence of the foreign material Z by a computer based on the difference data D3 of the said image data D1 and the image data D2 stored in the normal value memory | storage part 52. Is determined. In this case, the presence or absence of the foreign matter Z can be determined uniformly on a predetermined determination basis without requiring artificial judgment.

In addition, you may combine this determination process by a computer, and the judgment by a person. For example, if only the computer judges the presence or absence of the foreign matter Z, the image data D1 acquired by the X-ray visualizing device 16a, the image data D1 and the normal value storage are suspected. The operator may determine the image based on the difference data D3 of the normal image data D2 stored in the unit 52.

In addition, in this embodiment, as shown in FIG. 1, the foreign material detection apparatus 10 is equipped with the radiation shielding box 40 in order to prevent the X-ray 30 from leaking to the exterior. The radiation shielding box 40 partitions the curved part W in which the metal foil 20 was bent in the conveyance path 12, and the area | region P to which the X-ray 30 is irradiated from the X-ray irradiator 14, The radiation is shielded in the region P. Although the part in which the roller 22 was provided in the radiation shielding box 40 is open, the said roller 22 is comprised with the material which interrupts the X-rays 30. As shown in FIG. Such a roller 22, the metal foil 20 caught by the roller 22, and the radiation shielding box 40 cooperate with each other, and the X-ray 30 is prevented from leaking outside.

In addition, in this embodiment, as shown in FIG. 1, the conveyance path | route 12 of the metal foil 20 is curved. And the X-ray irradiator 14 is arrange | positioned at one side of the tangent L set at the top part T of the said curved part W, and the X-ray detector 16 is arrange | positioned at the other side of the said tangent L. As shown in FIG. . In this case, in the conveyance path | route of the metal foil 20, the clearance gap on the inlet side S1 side of the radiation shielding box 40 is roughly opposite to the direction which the X-ray detector 16 irradiates X-rays 30 with. Located in Moreover, the X-ray 30 irradiated from the X-ray detector 16 and reflected on the metal foil 20 conveyed reflects in the direction opposite to the entrance S1 of the radiation shielding box 40. For this reason, the X-rays 30 are hard to exit from the gap on the inlet S1 side of the radiation shielding box 40. In addition, the gap which arises in the exit S2 side of the radiation shielding box 40 becomes the back side of the site | part where the metal foil 20 is conveyed from the position where the X-ray detector 16 is arrange | positioned. For this reason, the X-ray 30 irradiated from the X-ray detector 16 hardly comes out from the clearance gap on the said exit S2 side.

Thus, in this foreign material detection apparatus 10, the X-ray 30 is irradiated along the conveyance path 12 from the one with respect to the bent conveyance path | route 12 of the metal foil 20. FIG. For this reason, when the area | region P to which the X-ray 30 is irradiated from the X-ray irradiator 14 is partitioned by the radiation shielding box 40 as mentioned above, the reflection direction of the X-ray 30 is a metal foil ( 20) Do not face in the direction of the entrance or exit. For this reason, it is easy to prevent the leakage of the X-rays 30.

In addition, a gap is generated in the inlet S1 and the outlet S2 of the radiation shielding box 40 along the conveyance path of the metal foil 20. In this embodiment, in order to prevent the leakage of the X-ray 30 from such a clearance, the conveyance path | route 12 of the metal foil 20 to the inlet S1 and the outlet S2 of such a radiation shielding box 40 is carried out. A shield plate 42 is disposed along the line. By this shielding plate 42, the X-ray 30 leaks to the outside along the transport path 12 of the metal foil 20 from the gap between the inlet S1 and the outlet S2 of the radiation shielding box 40. It is preventing.

In addition, what is necessary is just to provide the shielding plate 42 as needed. In the example shown in FIG. 1, although the shielding plate 42 is provided in both the inlet S1 and the outlet S2 of the radiation shielding box 40, you may provide in either one. In addition, when the X-rays 30 do not leak from the inlet S1 and the outlet S2 of the radiation shielding box 40 to the outside, the shielding plate 42 may not be provided. In addition, the shielding plate 42 extends along the conveyance path 12 of the metal foil 20 to the outer side of the radiation shielding box 40 as shown in FIG. Although not shown, the shielding plate 42 may extend along the conveyance path 12 of the metal foil 20 inside the radiation shielding box 40.

As mentioned above, although the foreign matter detection apparatus which concerns on 1st Embodiment of this invention was illustrated, the foreign matter detection apparatus which concerns on this invention is not limited to the above.

For example, in the above-described embodiment, the X-ray visualization apparatus 16a which produces | generates image data based on the X-ray detection data detected by the X-ray detector 16 is provided. In the case of determining the presence or absence of the foreign matter Z, in particular, when it is not necessary to generate image data, such an X-ray visualization apparatus 16a is not necessarily required. When the X-ray visualizing apparatus 16a is not used, the determination unit 50 does not generate image data based on the X-ray detection data detected by the X-ray detector 16, and the foreign matter Z is not present. It may be configured to determine the presence or absence.

Also, as shown in FIG. 1, the normal value storage unit also determines the presence or absence of foreign matter Z without generating image data based on the X-ray detection data detected by the X-ray detector 16. You may provide 52. With respect to the X-ray detection data, a normal value storage unit 52 that stores normal detection data obtained in a state where no foreign matter is present on the metal foil may be provided. In this case, the determination unit 50 may determine the presence or absence of the foreign matter Z based on the X-ray detection data detected by the X-ray detector 16 and the normal detection data stored in the normal value storage unit 52. do.

For example, as a structure which determines the presence or absence of the foreign material Z, as shown in FIG. 1, the difference processing part 54 and the determination processing part 56 may be provided in the foreign matter detection apparatus 10. As shown in FIG. In this case, the difference processing unit 54 obtains difference data between the X-ray detection data detected by the X-ray detector 16 and the normal X-ray detection data stored in the normal value storage unit 52. Then, the determination processing unit 56 determines the presence or absence of the foreign matter Z based on the difference data obtained by the difference processing unit 54. The foreign substance detection apparatus 10 may be comprised so that presence or absence of the foreign substance Z may be determined, without generating image data.

In addition, in the above-mentioned embodiment, although the metal foil 20 has illustrated the form in which the electrode material 20a was apply | coated, the metal foil 20 as an inspection object shows the electrode material 20a as shown in FIG. It does not have to be applied. As described above, the foreign matter detection device 10 can be used to detect the foreign matter Z attached to the metal foil 20.

In addition, the electrode material 20a may be apply | coated on both surfaces of the metal foil 20 in some cases. The foreign substance detection apparatus 10 can also be comprised so that the foreign material Z can be detected in both surfaces of the metal foil 20. FIG. 7 shows a foreign matter detection device 10A configured to be able to detect the foreign matter Z on both surfaces of the metal foil 20. In this foreign matter detection apparatus 10A, the conveyance path 12 of the metal foil 20 is the first side W1 that bends and conveys the surface F1 on one side of the metal foil 20 outward and the opposite side to the metal foil. Is provided with the 2nd part W2 which bends the surface F2 toward the outer side, and conveys it. The foreign material detection apparatus 10A is provided with X-ray irradiators 14A and 14B and X-ray detectors 16A and 16B, respectively, on both of the first portion W1 and the second portion W2.

Thereby, by irradiating X-ray 31 to the surface F1 of the one side of the said metal foil 20 in the 1st part W1 which bent and conveyed the surface F1 of the one side of the metal foil 20 toward the outer side. The foreign matter Z1 on the surface F1 can be detected. Moreover, the X-ray 32 is made to the surface F2 on the opposite side to the said metal foil 20 by the 2nd part W2 which bend | folded and conveyed the surface F2 on the opposite side of the metal foil 20 toward outward. By irradiating, the foreign material Z2 of the said surface F2 can be detected. According to this foreign matter detection apparatus 10A, both surfaces F1 and F2 of the metal foil 20 can be inspected in order. In addition, in the both surfaces of the metal foil 20, when it is comprised so that foreign material Z can be detected, a foreign material detection apparatus can be comprised compactly.

In addition, in the above-mentioned embodiment, as shown in FIG. 1, with respect to the curved part W in which the metal foil 20 was curved in the conveyance path | route 12, the X-ray irradiator (upstream) of the conveyance path | route 12 14 is disposed and the X-ray detector 16 is disposed downstream of the conveyance path 12. Not limited to this, for example, as shown in FIG. 8, the X-ray irradiator downstream of the conveying path 12 with respect to the curved portion W in which the metal foil 20 is curved in the conveying path 12. You may arrange | position (14) and the X-ray detector 16 may be arrange | positioned upstream of the conveyance path | route 12. As shown in FIG.

Moreover, in embodiment mentioned above, the X-ray irradiator 14 is arrange | positioned at one side with respect to the tangent L set so that the metal foil 20 may be bent and passed through the top part T of the curved part W, The X-ray detector 16 is disposed on the other side. The arrangement of the X-ray irradiator 14 and the X-ray detector 16 is not limited to this form. Although illustration is abbreviate | omitted, the tangent L is set in the position which shifted to the circumferential direction from the top part T of the curved part W by which the metal foil 20 is bent and conveyed, and an X-ray irradiator to one side of the said tangent L You may arrange | position (14) and arrange | position the X-ray detector 16 on the other side.

In addition, in embodiment mentioned above, the conveying apparatus 120 has illustrated the form which has the curved part W to convey, conveying the metal foil 20. FIG. The conveyance path | route 12 of the metal foil 20 formed by the conveyance apparatus 120 is not limited to this form. That is, the conveyance path | route 12 of the metal foil 20 does not necessarily have the curved part W curved by constant curvature. Although not shown, the foreign matter detection apparatus 10 may be provided with the conveyance path | route 12 of the metal foil 20 bent by the some roller in the site | part to which the X-ray 30 is irradiated.

For example, as shown in FIG. 9, the foreign substance detection apparatus 10B may convey the strip | belt-shaped metal foil 20 along the curved conveyance path 12. As shown in FIG. In the form shown in FIG. 9, the conveyance path | route of the metal foil 20 is bent by the two rollers 22a and 22b, and metal foil (along the straight line L1 is provided between the said two rollers 22a and 22b). The portion W3 to which 20 is conveyed is formed.

In this embodiment, the X-ray irradiator 14 is arrange | positioned at one side of the said straight line L1, and the X-ray detector 16 is arrange | positioned at the other side of the said straight line L1. Then, the X-ray irradiator 14 irradiates the X-ray 30 along the straight line L1, and the X-ray 30 irradiated along the straight line L1 is irradiated by the X-ray detector 16. It is detecting.

And based on the X-ray 30 observed by the X-ray detector 16, the foreign material Z on the metal foil 20 is detected. In this case, on the straight line L1 between the two rollers 22a and 22b, the foreign matter Z included in the foreign material Z on the metal foil 20 (the foreign matter Z included in the electrode material 20a coated and applied to the metal foil 20). )) Can be detected.

In this method, the shadow of the X-rays 30 caused by the foreign matter Z is observed while the foreign matter Z passes through the straight line L1 between the two rollers 22a and 22b. For this reason, even when the conveyance speed of the metal foil 20 is the same, since the time which can capture | acquire the foreign material Z becomes long, it becomes possible to detect foreign matter Z more reliably. In this case, what is necessary is just to adjust the distance between two rollers 22a and 22b suitably so that the foreign material Z can be detected reliably.

In this manner, the foreign matter detection device may convey the strip-shaped metal foil 20 along the bent conveyance path 12. In this case, the X-ray irradiator 14 radiates to the one side of the direction in which the metal foil 20 is conveyed so as to irradiate the X-ray 30 along the conveyance path 12 to the portion where the metal foil 20 is bent and conveyed. You just need to be arranged. In addition, the X-ray detector 16 should just be arrange | positioned with respect to the direction to which the metal foil 20 is conveyed with respect to the part to which the metal foil 20 is bent and conveyed. Then, the X-ray detector 16 irradiated from the X-ray irradiator 14 may be detected by the X-ray detector 16. Thereby, the foreign material Z on the metal foil 20 (including the foreign material Z contained in the electrode material 20a apply | coated to the metal foil 20) can be detected, conveying the metal foil 20 by this. . Thus, various methods can be employ | adopted for the method of bending the conveyance path | route of the metal foil 20.

Moreover, in embodiment mentioned above, the lithium ion secondary battery was mentioned as a use which this metal foil 20 is used. The use for which the metal foil 20 is used is not limited to a lithium ion secondary battery. Such a metal foil 20 can be used for current collectors of various batteries, and can be used for various batteries. Here, the term "battery" refers to a general electrical storage device capable of extracting electrical energy, and includes, for example, a secondary battery such as a lithium ion secondary battery, a metal lithium secondary battery, a nickel hydrogen battery, a nickel cadmium battery, and the like. ) And a primary battery and a power storage device such as an electric double-layer capacitor.

The foreign matter detection device and the foreign matter detection method described above can be incorporated into the battery manufacturing method. Hereinafter, an example is given about the manufacturing method of the battery which used metal foil as an electrical power collector.

For example, as shown in FIG. 10, this battery 1000 is composed of a rectangular metal battery case 300. The wound electrode body 310 is accommodated in the battery case 300.

In this embodiment, as shown in FIGS. 11 and 12, the wound electrode body 310 includes a positive electrode sheet 311 and a negative electrode sheet 313 as a strip-shaped electrode. Further, as the strip-shaped separator, a first separator 312 and a second separator 314 are provided. The positive electrode sheet 311, the first separator 312, the negative electrode sheet 313, and the second separator 314 are stacked and wound up in this order.

The positive electrode sheet 311 is coated with an electrode material 311d containing a positive electrode active material on both surfaces of the aluminum foil (corresponding to the metal foil 20 (see FIG. 1)) as the current collector sheet 311c. The negative electrode sheet 313 is coated with an electrode material 313d containing a negative electrode active material on both surfaces of copper foil (corresponding to the metal foil 20 (see FIG. 1)) as the current collector sheet 313c. The separators 312 and 314 are membranes through which an ionic substance can permeate. In this embodiment, a microporous membrane made of polypropylene is used.

In addition, in this embodiment, the electrode materials 311d and 313d are applied to the current collector sheets 311c and 313c at the one side in the width direction. Electrode materials 311d and 313d are not applied to the edge portions of the current collector sheets 311c and 313c opposite to the width direction. Among the positive electrode sheet 311 and the negative electrode sheet 313, portions where the electrode materials 311d and 313d are applied to the current collector sheets 311c and 313c are referred to as application portions 311a and 313a, and the current collector sheet ( The portions where the electrode materials 311d and 313d are not coated on 311c and 313c are referred to as uncoated portions 311b and 313b.

FIG. 11: is sectional drawing of the width direction which shows the state which the positive electrode sheet 311, the 1st separator 312, the negative electrode sheet 313, and the 2nd separator 314 piled in order. The coating part 311a of the positive electrode sheet 311 and the coating part 313a of the negative electrode sheet 313 oppose the separators 312 and 314, respectively. As shown to FIG. 11 and FIG. 12, the uncoated part of the positive electrode sheet 311 and the negative electrode sheet 313 in the both sides of the direction orthogonal to the winding direction of the wound electrode body 310 (winding axis direction). 311b and 313b protrude from the separators 312 and 314, respectively. The uncoated portions 311b and 313b of the positive electrode sheet 311 and the negative electrode sheet 313 form current collectors 311b1 and 313b1 of the positive electrode and the negative electrode of the wound electrode body 310, respectively.

As illustrated in FIG. 10, the battery case 300 is provided with a positive electrode terminal 301 and a negative electrode terminal 303. The positive electrode terminal 301 is electrically connected to the positive electrode current collector 311b1 of the wound electrode body 310. The negative electrode terminal 303 is electrically connected to the negative electrode current collector 313b1 of the wound electrode body 310. The battery case 300 is filled with an electrolyte solution. The electrolyte solution may be composed of a nonaqueous electrolyte solution such as a mixed solvent such as diethyl carbonate and ethylene carbonate containing an appropriate amount of an appropriate electrolyte salt (for example, lithium salt such as LiPF ₆ ).

The foreign matter detection apparatus 10 (refer FIG. 1 and FIG. 2) mentioned above can detect the foreign material Z contained in the positive electrode sheet 311 and the negative electrode sheet 313. FIG. The foreign matter Z included in the battery 1000 can be reduced by incorporating such a foreign matter detection device 10 into the manufacturing process of the battery 1000.

In this case, the foreign matter detection device 10 may detect the foreign matter Z included in the positive electrode sheet 311 and the negative electrode sheet 313, for example, in a step before assembling the battery 1000. What is necessary is just to incorporate into the manufacturing process of (1000). In the above-described embodiment, as shown in FIG. 2, the foreign matter detection device 10 is built in the electrode material coating device 100 that applies electrode material to the current collector sheets 311c and 313c (metal foil). However, it is not limited to this form. For example, the foreign matter detection device 10 is applied to all the steps of the step of being stacked and wound in the order of the positive electrode sheet 311, the first separator 312, the negative electrode sheet 313, and the second separator 314. ) May be embedded. In addition, the foreign matter detection apparatus 10 detects the foreign matter adhering on the current collector sheets 311c and 313c before applying the electrode materials 311d and 313d to the current collector sheets 311c and 313c. You may use it as an apparatus (refer FIG. 6).

In this manner, the foreign matter contained in the battery can be reduced by incorporating the foreign matter detection device 10 into the battery manufacturing process. As a result, a secondary battery having less foreign matters can be produced in the battery, and the quality of the secondary battery can be improved to prevent deterioration of the performance of the secondary battery, and the life of the secondary battery can be extended. have.

A plurality of such lithium-ion secondary batteries are combined to form the assembled battery 1000, and are mounted as a power source of the vehicle 2000, for example, as shown in FIG. 13. The present invention contributes to the stability of the performance of such a battery for a vehicle and to the long life. For example, the vehicle 2000 can be applied as a power source (secondary battery) of an automobile including an electric motor such as a hybrid vehicle, an electric vehicle, and a fuel cell vehicle.

10, 10A, 10B: foreign matter detection device
12: return path
14, 14A, 14B: X-Ray Irradiator
14a: control unit
16, 16A, 16B: X-ray detector
16a: X-ray visualization device
20: Metal foil
20a: electrode material
22, 22a, 22b: roller
30, 31, 32: X-ray
40: radiation shielding box
42: shield plate
50: judgment unit
52: normal value storage unit
54: difference processing unit
56: judgment processing unit
100: electrode material coating construction device
101: drawing unit
102: coating unit
103: drying unit
104: winding part
105: transport control
106: guide roll
112: back roll
114: application head
120: conveying device
300: battery case
301: Positive electrode terminal
303: Negative terminal
310: wound electrode body
311 positive electrode sheet
311a:
311b: unpainted construction department
311b1: Positive electrode current collector
311c: collector sheet (metal foil)
311d: electrode material
312, 314: separator
313: negative electrode sheet
313a:
313b: Unpainted construction department
313b1: anode collector
313c: collector sheet (metal foil)
313d: electrode material
1000: Battery (Assembled Battery)
2000: vehicles
L, L1: Tangent
W, W1, W2, W3: curved portion (part where metal foil is bent and conveyed)
Z, Z1, Z2: foreign matter
T: top

Claims (17)

It is a foreign substance detection device which detects the foreign substance contained in the electrode material apply | coated to the strip-shaped metal foil,
A conveying apparatus which conveys the said metal foil along the curved conveyance path,
An X-ray irradiator arranged at one side of the direction in which the metal foil is conveyed and irradiated with X-rays along the conveyance path to a portion where the metal foil is bent and conveyed;
And an X-ray detector which is arranged on the other side of the direction in which the metal foil is conveyed, and which detects the X-rays irradiated from the X-ray irradiator with respect to a portion where the metal foil is bent and conveyed. The foreign matter detection device according to claim 1, further comprising a determination unit that determines the presence or absence of the foreign matter based on the X-ray detection data detected by the X-ray detector. A normal value storage section according to claim 2, further comprising a normal value storage section for storing normal detection data obtained in a state where no foreign matter is present with respect to X-ray detection data detected by the X-ray detector,
And the determining unit determines the presence or absence of the foreign matter based on the X-ray detection data detected by the X-ray detector and the normal detection data stored in the normal value storage unit. The foreign matter detection device according to claim 1, further comprising an X-ray visualization device that generates image data based on the X-ray detection data detected by the X-ray detector. The normal value storage section according to claim 4, wherein the image data obtained by the X-ray visualization apparatus stores normal image data obtained in a state where no foreign matter is present.
And a difference processing unit for obtaining difference data between the image data acquired by the X-ray visualization apparatus and the normal image data stored in the normal value storage unit. The foreign matter detection device according to claim 5, further comprising a determination unit that determines the presence or absence of the foreign matter based on the difference data obtained by the difference processing unit. The radiation shielding box according to any one of claims 1 to 6, wherein the radiation shielding box for partitioning an area where X-rays are irradiated from the X-ray irradiator with respect to a portion where the metal foil is bent and conveyed by the conveying device is provided. The foreign matter detection apparatus provided. The foreign matter detection device according to claim 7, wherein a shielding plate is disposed along a conveyance path of the metal foil at an inlet or an outlet of the radiation shielding box. The said conveying apparatus is a conveyance apparatus of any one of Claims 1-6, Comprising: The 1st part which bends and conveys the one side surface of the said metal foil toward an outer side to the conveyance path | route of the said metal foil, and the surface on the opposite side of metal foil. Having a second portion that is bent toward the outside and conveyed,
The foreign material detection apparatus which arrange | positioned the said X-ray irradiator and the said X-ray detector with respect to both of the said 1st part and the 2nd part, respectively. The said conveying apparatus has the curved part conveyed, bending the said metal foil, The said X-ray irradiator is arrange | positioned at one side of the tangent of the said curved part, The said X-ray of any one of Claims 1-6. The detector is disposed on the other side of the tangent. The foreign matter detection device according to claim 10, wherein the tangent is set so as to pass through a top portion of a curved portion where the metal foil is bent and conveyed in the conveyance path of the metal foil. The foreign material detection device according to claim 10, wherein the conveying device includes a roller that guides the metal foil to the curved portion. The foreign matter detection device according to any one of claims 1 to 6, further comprising a control unit for controlling the intensity of X-rays irradiated by the X-ray irradiator. The electrode material application | coating apparatus of any one of Claims 1-6 arrange | positioned at the post process of the coating device which apply | coats an electrode material to the said metal foil. delete While conveying the strip | belt-shaped metal foil by which the electrode material was apply | coated along the curved conveyance path | route, X-rays are irradiated along the conveyance path | route from one side with respect to the said bent conveyance path | route, based on the said X-ray observed from the other, The foreign substance detection method which detects the foreign substance contained in the electrode material apply | coated to metal foil. It is a manufacturing method of the battery which has an electrical power collector sheet by which electrode material was apply | coated to metal foil, and the manufacturing method of the battery provided with the foreign material detection method of Claim 16.

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