JP2014123491A - Device for manufacturing electrode for cell and process of manufacturing electrode - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture an electrode for a fuel cell while suppressing generation of wrinkles.SOLUTION: The device for manufacturing an electrode for a cell includes: a press roller that rolls a substrate having a coated part where an electrode is coated and a non-coated part where the electrode is not coated; and a conveyance roller that conveys the rolled substrates. The conveyance roller is of a shape in which the roller contacts the coated part and does not contact the non-coated part.

Description

  The present invention relates to an electrode manufacturing apparatus and method for use in a battery.

  2. Description of the Related Art A thin film transport apparatus having a transport mechanism that transports a thin film while maintaining the tension of the thin film using an elastic nip roller having elasticity when forming a plurality of coated portions on the thin film is known (Patent Document) 1). In this thin film transport device, the elastic nip roller is provided with a suppression means for suppressing contact between the non-coated portion located between the coated portions formed along the thin film transport direction and the surface of the elastic nip roller. It has been.

JP 2009-280355 A

  This thin film transport device has the problem of preventing the occurrence of wrinkles and tears in the elastic nip roller, but it is sufficient from the viewpoint of maintaining the tension in the rolling process using the press roller and improving the rolling quality. There was a problem that no ingenuity was made.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms.

(1) According to one aspect of the present invention, an electrode manufacturing apparatus for a battery is provided. In this form of the battery electrode manufacturing apparatus, a coating part in which an electrode layer is applied to the central part along the longitudinal direction of the belt-like base material and the electrodes provided on both ends of the coating part are applied. A non-coated portion that is not machined, a press roller that rolls the electrode layer of the material to be rolled, and a conveyance roller that conveys the material to be rolled that has been rolled by the press roller. The shape is in contact with the coated part and not in contact with the non-coated part. According to the battery electrode manufacturing apparatus of this embodiment, since the transport roller is in contact with only the coating part, the tension for transporting the substrate after rolling is applied only to the coating part and not to the non-coating part. Therefore, it can suppress that a wrinkle arises when tension | tensile_strength is applied to a non-coating part.

(2) The transport roller has a large-diameter cylindrical portion in contact with the coating portion and a small-diameter cylindrical portion not in contact with the coating portion, and the diameter of the large-diameter cylindrical portion is φA, Diameter is φB,
The small diameter when it is assumed that the holding angle of the coated portion in the large diameter cylindrical portion is θ2, the diameter in the large diameter cylindrical portion is smaller than φA, and the small diameter cylindrical portion is brought into contact with the non-coated portion. The holding angle of the non-coated portion of the base material in the cylindrical portion is θ1, the stretching rate of the electrode layer is C, the thickness of the coated portion after the stretching is D, the thickness of the base material is E, and Then, φA> (φB−D + E) * (θ1 / θ2) * C may be satisfied. According to the battery electrode manufacturing apparatus of this embodiment, it is possible to calculate the optimum conveying roller diameter.

(3) In the battery electrode manufacturing apparatus of the above aspect, the value of C may be greater than 1 and 1.005 times or less. According to the battery electrode manufacturing apparatus of this embodiment, since the value of C exceeds 1 and is 1.005 times or less, it is difficult to cause wrinkles in the non-coated portion.

(4) In the battery electrode manufacturing apparatus of the above aspect, assuming that the width of the portion of the transport roller that contacts the coating portion is G and the width of the coating portion is L, 0.8 * L <G < The conveying roller may be formed so as to be L. According to the battery electrode manufacturing apparatus of this embodiment, it is possible to suppress the tension from being applied to the non-coated portion.

(5) In the electrode manufacturing apparatus of the said form, the both ends of the said small diameter cylindrical part side of the said large diameter cylindrical part may be chamfered. According to the electrode manufacturing apparatus of this form, it can suppress that a conveyance roller damages a coating part.

(6) According to one form of this invention, the manufacturing method of the electrode for batteries is provided. The method for manufacturing an electrode for a battery includes: a coating part in which an electrode layer is applied to a central part along a longitudinal direction of a belt-like base material; and the electrode provided on both ends of the coating part. A rolling process for rolling the electrode layer of the material to be rolled having a non-coated part, and a conveying process for conveying the material to be rolled rolled by the press roller using a conveying roller. The transport roller includes a portion in contact with the coating portion and a portion not in contact with the non-coating portion, and applies the tension to the portion in contact with the coating portion in the transporting step, and the rolled base material. Transport. According to the battery electrode manufacturing method of this embodiment, since the transport roller is in contact with only the coating part, the tension for transporting the rolled base material is applied only to the coating part and applied to the non-coating part. Since there is no wrinkle, it can suppress that a wrinkle arises when tension is applied to a non-coating part.

  The present invention can be realized in various forms. For example, in addition to a battery electrode manufacturing apparatus, a battery electrode manufacturing method, an electrode film transport apparatus, an electrode film transport method, and the like Can be realized.

It is explanatory drawing which shows a part of electrode film manufacturing apparatus concerning one Example of this invention. It is explanatory drawing which expands and shows a conveyance roller. It is explanatory drawing explaining a formula (3) theoretically. It is explanatory drawing which shows the relationship between the diameter (phi) B of the part which does not contact the non-coating part of a conveyance roller, the diameter (phi) A of the part which contacts a coating part, and generation | occurrence | production of a wrinkle.

  FIG. 1 is an explanatory view showing a part of an electrode film manufacturing apparatus according to an embodiment of the present invention. The electrode film manufacturing apparatus 10 includes a coating apparatus 100, a press roller 110, a transport roller 120, and a winding roller 130. The coating apparatus 100 is an apparatus that coats the electrode layer 210 on both surfaces of a belt-like substrate 200. The coating apparatus 100 applies the electrode layer 210 to the center of the substrate 200 along the band formed by the substrate 200. In the present embodiment, a gravure coater is used as the coating apparatus 100. When the thickness of the electrode layer 210 (hereinafter, the “electrode layer 210” is also referred to as the “coating portion 210”) is thin, the thickness of the electrode layer 210 can be controlled uniformly by using a gravure coater. Is easy. As a material of the electrode layer 210, for example, a lithium cobalt composite oxide or a lithium manganese composite oxide can be used.

  There are two press rollers 110, which are arranged so as to sandwich the substrate 200 coated with the electrode layer 210 from both sides. The two press rollers 110 are rolling devices that press the base material 200 coated with the electrode layer 210 from both sides and roll the electrode layer 210 C times in the longitudinal direction. The rolling ratio (also referred to as the stretching ratio) is preferably more than 1.0 and 1.01 or less, and more preferably more than 1.0 and 1.005 or less. The winding roller 130 is a winding device that winds the rolled base material 200 into a roll.

  The conveyance roller 120 is a roller provided between the press roller 110 and the winding roller 130, and is a conveyance device that conveys the rolled base material 200 to the winding roller 130. Further, the transport roller 120 has a function of removing wrinkles generated in the rolling process. The conveyance roller 120 has a large diameter cylindrical portion 120a and a small diameter cylindrical portion 120b having different thicknesses. The large-diameter cylindrical portion 120 a forms the central portion of the transport roller 120 and contacts the electrode layer 210 of the substrate 200. The small-diameter cylindrical portion 120 b forms both end portions of the transport roller 120 and does not contact the electrode layer 210 of the base material 200. The angle at which the conveyance roller 120 comes into contact with the substrate 200 is expressed as an angle, which is called “a holding angle”. The holding angle is an angle of a portion where the large-diameter cylindrical portion 120 a contacts the electrode layer 210. In the present embodiment, the holding angle at which the large-diameter cylindrical portion 120a contacts the electrode layer 210 is θ2. The holding angle θ2 can be measured.

FIG. 2 is an explanatory view showing the conveying roller in an enlarged manner. In FIG. 2, the transport roller 120 and the substrate 200 on which the electrode layer 210 is applied are illustrated. The base material 200 on which the electrode layer 210 after rolling is coated has a thickness D, and the base material 200 has a thickness E. The thickness D is the sum of the thickness E of the substrate 200 and the thicknesses of the two electrode layers 210. If the thickness of only the electrode layer 210 is d,
D = E + 2 * d (1)
It becomes. The width of the electrode layer 210 applied is L.

The large-diameter cylindrical portion 120a has a diameter φA and a width G. The small-diameter cylindrical portion 120b has a diameter φB. Let x be the difference in radius between the large diameter cylindrical portion 120a and the small diameter cylindrical portion 120b. The size of the width G is smaller than the size of the width L on which the electrode layer 210 is applied so as not to apply tension to a portion where the electrode layer 210 is not applied. In addition, since the tension | tensile_strength cannot be given to the electrode layer 210 when the magnitude | size of the width | variety G is too smaller than the width | variety L, it is preferable that the width | variety L is larger than 0.8 * G. Therefore, the width L and the width G preferably satisfy the following relationship.
0.8 * L <G <L (2)

  Further, both end portions of the large diameter cylindrical portion 120a may be chamfered. If both end portions of the large diameter cylindrical portion 120a are chamfered, it is possible to make it difficult for the large diameter cylindrical portion 120a to mechanically damage the electrode layer 210 of the substrate 200.

  According to the electrode film manufacturing apparatus of this embodiment, since the transport roller 120 is in contact with only the electrode layer 210, the tension for transporting the rolled base material 200 is applied only to the electrode layer 210, and the electrode layer 210 is coated. Since it is not applied to the part which is not made, it can suppress that a wrinkle arises when tension | tensile_strength is applied to the part to which the electrode layer 210 is not traveled.

Further, from examples and theoretical analysis described later, the diameter of the large-diameter cylindrical portion 120a that contacts the electrode layer 210 (coating portion) of the transport roller 120 is φA, and the small-diameter cylindrical portion 120b that does not contact the electrode layer 210 of the transport roller 120. ΦB, the holding angle of the coating portion 120 in the large-diameter cylindrical portion 120a of the conveying roller 120 is θ2, the stretching ratio by rolling is C, the thickness of the coating portion 120 after stretching is D, the thickness of the base material The substrate 210 coated with the electrode layer 210, which is not rolled, is coated with the electrode 210 with a conveying roller 120z having a diameter φz (φz = φB−D + E) instead of the conveying roller 120. When the holding angle of the electrode layer 210 when transporting the substrate 200 is θ1 (hereinafter also referred to as “theoretical holding angle θ1”),
φA> (φB−D + E) * (θ1 / θ2) * C (3)
It is preferable to satisfy.

FIG. 3 is an explanatory diagram for theoretically explaining the expression (3). FIG. 3A shows a case where the substrate 200 coated with the electrode 210 is conveyed by the conveying roller 120z. The conveyance roller 120 shown in FIG. 2 includes a large-diameter cylindrical portion 120a and a small-diameter cylindrical portion 120b. The conveyance roller 120z shown in FIG. 3A is a conveyance roller having a single diameter. The diameter φz of the transport roller 120z is z. In FIG. 3A, the thickness of only the electrode layer 210 is represented by d, and the thickness of the substrate 200 is represented by e. The following relationship exists between the magnitudes of D and E shown in FIG. 2 and d and e.
d = (DE) / 2 (4)
e = E (5)

The electrode layer 210 is in contact with the transport roller 120z, and the holding angle of the electrode layer 210 at this time is θ1. The length L1 of the coating part (electrode layer 210) at the holding angle θ1 is represented by the following formula (6).
L1 = z * π * (θ1 / 360) (6)

If the length of the coating part (electrode layer 210) is extended C times by rolling, the length L1C of the coating part (electrode layer 210) after stretching is represented by the following formula (7).
L1C = z * π * (θ1 / 360) * C (7)

  FIG. 3B is a diagram schematically showing an arrow when the small-diameter cylindrical portion 120b of FIG. 2 is cut along a 3B-3B cutting line. The small diameter cylindrical portion 120b of the transport roller 120 is in contact with a portion (base material 200) of the base material 200 where the electrode layer 210 is not coated. In FIG. 3B, four layers of the substrate 200, the electrode layer 210, the substrate 200, and the electrode layer 210 are visible from the inside. Here, the innermost base material 200 of the four layers is in contact with the small diameter cylindrical portion 120b, and the remaining three layers (electrode layer 210, base material 200, electrode layer 210) are not in contact with the small diameter cylindrical portion 120b. . Of these three layers, the innermost electrode layer 210 is in contact with the large-diameter cylindrical portion 120a indicated by a broken line.

In the present embodiment, the small-diameter cylindrical portion 120b is set so that the curvature of the base 200 in FIG. 3A and the curvature of the innermost base 200 in the four layers in FIG. 3B are the same. The diameter is determined. In this case, the holding angle of the base material 200 in the small-diameter cylindrical portion 120b is θ1, which is equal to the holding angle θ1 in the conveying roller 120z in FIG. Here, since the base material 200 does not stretch, the diameter of the small-diameter cylindrical portion 120b of the transport roller 120 is made larger than the diameter φz of the transport roller 120z in FIG. 3A by twice the thickness d of the electrode layer 210. , Φz + 2 * d, the curvature of the substrate 200 in FIG. 3A and the curvature of the innermost substrate 200 of the four layers in FIG. 3B can be made the same. Further, the holding angle can be set to the same θ1. And the small diameter cylindrical part 120b of the conveyance roller 120 just contacts the part (base material 200) in which the electrode layer 210 of the base material 200 is not coated. Therefore, the relationship of the following formula | equation (8) should just exist between the diameter (phi) B of the small diameter cylindrical part 120b of the conveyance roller 120, and the diameter (phi) z (= z) of the conveyance roller 120z.
φB = φz + 2 * d = z + 2 * d (8)

FIG.3 (c) is a figure which shows typically a cut surface when the large diameter cylindrical part 120a of FIG. 2 is cut | disconnected by the 3C-3C cutting line. Also in FIG. 3C, four layers of the substrate 200, the electrode layer 210, the substrate 200, and the electrode layer 210 are visible from the inside. Here, the two female electrode layers 210 from the inside of the four layers are in contact with the large-diameter cylindrical portion 120a. In addition, the base material 200 shown by the innermost broken line in the four layers is in contact with the small-diameter cylindrical portion 120b as described with reference to FIG. If the difference in diameter between the large diameter cylindrical portion 120a and the small diameter cylindrical portion 120b is 2 * x, the following equation (9) is established between the diameter φA of the large diameter cylindrical portion 120a and the diameter φB of the small diameter cylindrical portion 120b. There is a relationship to show.
φA = φB + 2 * x (9)

  In FIG. 3B, the uncoated base material 200 is just in contact with the small-diameter cylindrical portion 120 b of the transport roller 120. On the other hand, in FIG. 3C, the electrode 210 coated on the substrate 200 is just in contact with the large-diameter cylindrical portion 120 a of the transport roller 120. Here, if the diameter of the large-diameter cylindrical portion 120a is larger than the diameter φA shown in FIG. 3C, the electrode 210 applied to the base 200 is in contact with the large-diameter cylindrical portion 120a. The portion where the electrode layer 210 is not coated does not contact the small diameter cylindrical portion 120b.

In FIG. 3C, the holding angle of the electrode layer 210 is θ2. The length L2 of the coating part (electrode layer 210) corresponding to the holding angle θ2 is represented by the following formula (10).
L2 = φA * π * (θ2 / 360)
= (ΦB + 2 * x) * π * (θ2 / 360)
= (Φz + 2 * d + 2 * x) * π * (θ2 / 360) (10)

Here, since the length L1C and the length L2 are the same length, the following equation (11) is established.
(Φz * π) * (θ1 / 360) * C
= (Φz + 2 * d + 2 * x) * π * (θ2 / 360) (11)

In the equation (11), (φz + 2 * d + 2 * x) is equal to φA. Therefore, φA is expressed by the following equation (12).
φA = φz * (θ1 / θ2) * C (12)
By applying the equation (8) to the equation (12), the following equation (13) can be obtained.
φA = (φB−2 * d) * (θ1 / θ2) * C (13)
Here, as shown in FIG. 3A, since 2 * d is equal to DE, Expression (14) is obtained.
φA = (φB−D + E) * (θ1 / θ2) * C (14)
Therefore, if the diameter φA of the large diameter cylindrical portion 120a of the conveyance roller 120 satisfies the following expression (15) with respect to the diameter φB of the small diameter cylindrical portion 120b, the conveyance roller 120 and the electrode layer 210 are It is possible to contact only the substrate 200 and not to contact the substrate 200. Here, E is the thickness of the base material 200, and D is the thickness of the base material 200 coated with the electrode layer 210 after rolling. The thickness D includes the thickness e of the substrate 200 and the thickness 2 * d of the two electrode layers 210.
φA> (φB−D + E) * (θ1 / θ2) * C (15)

  In this example, an aluminum foil having a thickness of 15 μm was used as the substrate 200. The electrode layer 210 was applied to the base material 200 so that the sum of the thickness of the base material 200 and the thickness of the two electrode layers 210 was 160 μm. In this example, lithium cobalt composite oxide was used as the material of the electrode layer 210. Then, the base material 200 with which the electrode layer 210 was coated was rolled using the two press rollers 110 so that the length of the coating part of the electrode layer 210 might be 1.005 times. At this time, the tension applied to the substrate 200 before the press roller 110 was 45 N, and the tension applied to the substrate 200 after the press roller 110 was 100 N. After rolling by the press roller 110, the thickness D of the base material 200 coated with the electrode layer 210 was compressed from 160 μm to 124 μm, but the thickness E of the base material 200 itself was 15 μm and did not change.

  Thereafter, the base material 200 coated with the electrode layer 210 was transported to the winding roller 130 using the transport roller 120. Here, the diameter φB of the small-diameter cylindrical portion 120b that does not contact the non-coated portion of the transport roller 120 was set to 100 mm or 150 mm. The width G of the large-diameter cylindrical portion 120a of the conveying roller 120 is set to 0.8 times the width L of the coating portion, and the diameter φA of the large-diameter cylindrical portion 120a is the same as the diameter φB or slightly larger than the diameter φB. Then, the relationship between the diameter φA of the large-diameter cylindrical portion 120a and wrinkles was examined as the holding angle θ120 ° in the large-diameter cylindrical portion 120a.

  FIG. 4 is an explanatory diagram showing the relationship between the diameter φB of the portion that does not contact the non-coated portion of the transport roller, the diameter φA of the portion that contacts the coated portion, and the occurrence of wrinkles. When the draw ratio C is 1.005 times and the diameter φB of the small-diameter cylindrical portion 120b of the conveying roller 120 is 100 mm, wrinkles occur when the diameter φA of the large-diameter cylindrical portion 120a of the conveying roller 120 is larger than 100.5 mm. However, wrinkles occurred when the diameter φA of the large-diameter cylindrical portion 120a was 100 to 100.3 mm. Further, when the diameter φB of the small-diameter cylindrical portion 120b of the conveying roller 120 is 150 mm, if the diameter φA of the large-diameter cylindrical portion 120a of the conveying roller 120 is larger than 150.8 mm, no wrinkles occurred, but the large-diameter cylinder Wrinkles occurred when the diameter φA of the portion 120a was 150 to 100.6 mm.

  Further, when the stretching ratio C is 1.003 times and the diameter φB of the small-diameter cylindrical portion 120b of the conveying roller 120 is 100 mm, if the diameter φA of the large-diameter cylindrical portion 120a of the conveying roller 120 is larger than 100.3 mm, No wrinkles occurred, but wrinkles occurred when the diameter φA of the large-diameter cylindrical portion 120a was 100 mm. Further, when the diameter φB of the small-diameter cylindrical portion 120b of the conveying roller 120 is 150 mm, if the diameter φA of the large-diameter cylindrical portion 120a of the conveying roller 120 is larger than 150.6 mm, no wrinkles occurred, but the large-diameter cylinder When the diameter φA of the portion 120a was 150, wrinkles were generated.

From the above experimental results, the diameter φA of the large diameter cylindrical portion 120a, the diameter φB of the small diameter cylindrical portion 120b, the thickness D of the electrode after stretching, the thickness of the base material of the electrode as E, and the transport It has been confirmed that wrinkles do not occur when the holding angle between the roller 120 and the electrode layer 210 is θ2 and the theoretical holding angle θ1 is represented by the following equation (16).
φA> (φB−D + E) * (θ1 / θ2) * C (16)

In the equation (16), when the theoretical holding angle θ1 and the holding angle θ2 are the same value, θ1 and θ2 can be canceled and transformed into the equation (17).
φA> (φB−D + E) * C (17)

  In the present embodiment, the transport roller 120 transports the substrate 200 coated with the electrode layer 210 in contact with only the coating portion of the substrate 200 coated with the electrode layer 210. It is possible to apply the tension for conveying the base material 200 after rolling only to the coating part, and to suppress the generation of wrinkles by suppressing the tension from being applied to the non-coating part. Become.

  In particular, when the transport roller 120 satisfying the above formula (16) or formula (17) is used, the transport roller 120 is in contact with only the coating portion of the substrate 200 on which the electrode layer 210 is coated, and is not coated. Do not touch the engineering department.

  The difference between the diameter φA of the large-diameter cylindrical portion 120a of the conveying roller 120 and the diameter φB of the small-diameter cylindrical portion 120b is 0.5 mm (diameter φB = 0.5% with respect to 100 mm), 0.8 mm (diameter φB = The difference between φA and φB is slight. Therefore, the transport roller 120 is preferably formed of a rigid body such as a metal so as not to be deformed by tension.

  In the present embodiment, the description has been given using the configuration in which only one transport roller 120 is disposed between the press roller 110 and the take-up roll. However, a configuration including a plurality of transport rollers 120 may be used.

  The embodiments of the present invention have been described above based on some embodiments. However, the embodiments of the present invention described above are for facilitating the understanding of the present invention and limit the present invention. It is not a thing. The present invention can be changed and improved without departing from the spirit and scope of the claims, and it is needless to say that the present invention includes equivalents thereof.

DESCRIPTION OF SYMBOLS 10 ... Electrode film manufacturing apparatus 100 ... Coating apparatus 110 ... Press roller 120 ... Conveyance roller 120a ... Cylindrical part 120b ... Cylindrical part 130 ... Winding roller 200 ... Base material 210 ... Electrode φA, φB ... Diameter θ1, θ2 ... Holding angle

Claims (6)

An electrode manufacturing apparatus for a battery,
A coated portion in which an electrode layer is coated at a central portion along the longitudinal direction of the belt-shaped substrate, and a non-coated portion on which the electrodes provided at both ends of the coated portion are not coated. A press roller for rolling the electrode layer of the material to be rolled,
A transport roller for transporting the material to be rolled rolled by the press roller;
With
The battery transport electrode manufacturing apparatus has a shape in which the transport roller is in contact with the coating portion and not in contact with the non-coating portion. The electrode manufacturing apparatus for a battery according to claim 1,
The transport roller has a large-diameter cylindrical portion in contact with the coating portion, and a small-diameter cylindrical portion not in contact with the coating portion,
The diameter of the large diameter cylindrical portion is φA,
The diameter of the small diameter cylindrical portion is φB,
The holding angle of the coating part in the large diameter cylindrical part is θ2,
The holding angle of the non-coated portion of the base material in the small-diameter cylindrical portion when the diameter of the large-diameter cylindrical portion is made smaller than φA and the small-diameter cylindrical portion is brought into contact with the non-coated portion is θ1. ,
The stretching rate of the electrode layer is C,
The thickness of the coated part after the stretching is D,
When the thickness of the substrate is E,
φA> (φB−D + E) * (θ1 / θ2) * C
An electrode manufacturing apparatus for a battery that satisfies the requirements. The electrode manufacturing apparatus for a battery according to claim 2,
The apparatus for producing an electrode for a battery, wherein the value of the stretching ratio C exceeds 1 and is 1.005 times or less. In the electrode manufacturing apparatus for batteries as described in any one of Claims 1-3,
When the width of the portion of the transport roller that contacts the coating portion is G, and the width of the coating portion is L,
0.8 * L <G <L
An electrode manufacturing apparatus for a battery, in which the transport roller is formed to be In the electrode manufacturing apparatus for batteries as described in any one of Claims 1-4,
An electrode manufacturing apparatus for a battery, wherein both end portions of the large-diameter column portion on the small-diameter column portion side are chamfered. A method for producing an electrode for a battery, comprising:
A coated portion in which an electrode layer is coated at a central portion along the longitudinal direction of the belt-shaped substrate, and a non-coated portion on which the electrodes provided at both ends of the coated portion are not coated. A rolling step of rolling the electrode layer of the material to be rolled,
A conveying step of conveying the material to be rolled that has been rolled by the press roller using a conveying roller;
Have
The transport roller is
A portion that contacts the coated portion and a portion that does not contact the non-coated portion;
The manufacturing method of the electrode for batteries which applies the tension | tensile_strength to the part which contact | connects the said coating part in the said conveyance process, and conveys the said rolled base material.

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