Slit mold, rechargeable battery electrode, and method for manufacturing same

Abstract

The present invention provides a slit mold for manufacturing an electrode of a rechargeable battery, an electrode of a rechargeable battery manufactured using the same, and a method for manufacturing an electrode of a rechargeable battery using the same. The slit mold includes: a first block; a second block disposed on the first block; a third block disposed opposite to the second block; and a gasket member disposed between the second block and the third block and forming a slit outlet in the width direction and the height direction. The first block forms a first cavity that receives the supplied active material slurry, and a connection channel is formed between the first block and the second block in a width direction and a height direction of the slit outlet. The second block forms a second cavity that receives the active material slurry supplied through the connection channel, and discharges the received active material slurry through the slit outlet.

Description

Technical Field

[0001] The present disclosure relates to a slot die for manufacturing an electrode of a rechargeable battery, an electrode of a rechargeable battery, and a method of manufacturing an electrode of a rechargeable battery using the slot die. More specifically, the present disclosure relates to a slot die for manufacturing an electrode of a rechargeable battery, an electrode of a rechargeable battery, and a method of manufacturing an electrode of a rechargeable battery using the slot die, which minimizes a stagnant section of an active material slurry coated on a substrate. Background Art

[0002] Unlike a primary battery, a rechargeable battery is repeatedly charged and discharged. Small-capacity rechargeable batteries are used in small portable electronic devices such as mobile phones, laptop computers, and video cameras. Rechargeable batteries having a large capacity and high density are used as a power source for driving motors of hybrid vehicles and electric vehicles, or for energy storage.

[0003] A rechargeable battery includes an electrode assembly for charging current and discharging current, a case for accommodating the electrode assembly, an electrolyte solution, a cover plate coupled to an opening of the case, and electrode terminals for connecting the electrode assembly to the outside of the cover plate.

[0004] The electrode assembly may be formed by disposing electrodes on both sides of a separator as an electrically insulating material and winding the separator and the electrodes, laminating the separator and the electrodes, or a combination of laminating and winding the separator and the electrodes. The separator isolates electrodes of different polarities within the electrode assembly and continuously maintains ionic conductivity, enabling the electrode assembly to be charged and discharged.

[0005] An electrode is formed by coating an active material slurry on a substrate. A slot die is used to manufacture an electrode by coating an active material slurry on a substrate. The slot die forms a cavity for supplying the active material slurry, where the slot die includes a lower block and an upper block that set a height of a slot outlet for discharging the active material slurry, and a spacer member installed between the lower block and the upper block to set a width of the slot.

[0006] During the coating process, various qualities such as coating width, loading level, and start / end drag are managed. The loading level is calculated as the mass of the active material slurry per unit area (mg / cm 2 ), and is an important quality control item during the coating process. Summary of the Invention

[0007] Embodiments of the present disclosure provide a slot die for manufacturing electrodes of a rechargeable battery. In order to increase the single cell capacity of a new platform model, the slot die reduces the variation in the loading level in the width direction. Further, embodiments of the present disclosure provide a slot die for manufacturing electrodes of a rechargeable battery, which ensures the uniformity of the flow rate of the slurry discharged from the slot die in the width direction, thereby reducing the variation in the loading level in the width direction.

[0008] In addition, embodiments of the present disclosure provide an electrode of a rechargeable battery formed using a slot die for manufacturing electrodes of a rechargeable battery. Further, embodiments of the present disclosure relate to a method of manufacturing an electrode of a rechargeable battery using a slot die for manufacturing electrodes of a rechargeable battery.

[0009] A slot die for manufacturing electrodes of a rechargeable battery according to an embodiment includes: a first block; a second block disposed on the first block; a third block disposed opposite to the second block; and a spacer member disposed between the second block and the third block, the spacer member forming a slot outlet extending in the width direction and the height direction, wherein the first block forms a first cavity configured to receive the supplied active material slurry, and a connection channel is formed between the first block and the second block in the width direction and the height direction of the slot outlet, and the second block forms a second cavity for receiving the active material slurry supplied through the connection channel and discharges the received active material slurry through the slot outlet.

[0010] The first cavity may extend in the width direction and may include (i) a curved surface forming a space for receiving the active material slurry, and (ii) an inclined surface formed on one side of the curved surface and inclined upward toward the slot outlet, and the inclined surface may be connected to a planar groove formed on the upper surface of the first block.

[0011] The planar groove may extend in the front-rear direction intersecting the width direction, and the planar groove may be connected to the inclined surface, and the connection channel may be set as the space between the first planar groove and the lower surface of the second block placed on the first planar groove.

[0012] The second cavity may penetrate the second block in the vertical direction and may be formed in a length corresponding to the first cavity in the width direction.

[0013] The inclined surface may be a first inclined surface, the second cavity may include a second inclined surface inclined upward toward the slot outlet, and the second inclined surface may be connected to the planar groove at the lower surface of the second block.

[0014] The connection channel can be the first connection channel, and a second connection channel can be formed between the second block and the third block. The second cavity can extend in the width direction to form a space for receiving the active material slurry, and includes a second inclined surface formed on a side inclined upward toward the slit outlet. And the planar groove can be the first planar groove, and the second inclined surface can be connected to the second planar groove formed on the upper surface of the second block.

[0015] The second planar groove can extend in the front-back direction intersecting the width direction, and the second planar groove can be connected to the second inclined surface. The second connection channel can be set as the space between the inner surfaces at both ends of the gasket member, the second planar groove, and the lower surface of the third block placed on the second planar groove.

[0016] The slit outlet can be connected to the second connection channel, and the slit outlet can be set between the upper surface of the second block and the lower surface of the third block in the height direction, and between the inner surfaces at both ends of the gasket member in the width direction.

[0017] The first cross-section of the first cavity in the vertical direction can be larger than the second cross-section of the second cavity in the vertical direction.

[0018] The second cavity forms an opening having uniform dimensions in the front-back direction and extending along the width direction, and the distance from the opening of the second cavity to the slit outlet is uniformly set in the width direction.

[0019] The second cavity can penetrate the second block in the vertical direction and is formed to extend in the width direction by a length corresponding to the length of the first cavity in the width direction, and the second cavity can be formed by a concave inclined surface inclined upward toward the slit outlet.

[0020] The slit outlet can be connected to the concave inclined surface, and the slit outlet can be set by the upper surface of the second block in the front-back direction and the width direction, the inner surfaces at both ends of the gasket member, and the lower surface of the third block provided on the second cavity.

[0021] The second cavity can form an opening with uniform dimensions in the width direction and the front-back direction, and the distance from the second cavity to the slit outlet is the largest at the middle in the width direction of the second cavity and the smallest at both ends in the width direction of the second cavity.

[0022] The second cavity can form an opening, the dimension of which in the front-back direction intersecting the width direction varies in the width direction. The distance from the second cavity to the slit outlet can be the largest at the middle in the width direction of the second cavity and the smallest at both ends in the width direction of the second cavity.

[0023] The size of the opening formed by the second cavity in the front-rear direction may be minimized at the middle in the width direction of the second cavity and may be maximized at both ends in the width direction of the second cavity.

[0024] Furthermore, the electrodes of the rechargeable battery according to an embodiment of the present disclosure may be manufactured using a slot die for manufacturing electrodes of a rechargeable battery.

[0025] The substrate in a wet state may have a maximum slurry loading level of 17.43 mg / cm 2 in the width direction of the substrate and a minimum slurry loading level of 17.16 mg / cm 2 in the width direction of the substrate.

[0026] Furthermore, a method for manufacturing an electrode of a rechargeable battery may include manufacturing an electrode by applying an active material slurry to a substrate using a slot die for manufacturing electrodes of a rechargeable battery.

[0027] The slot die according to an embodiment connects a first cavity and a second cavity in the height direction with a first connection channel to minimize the stagnation of the slurry in the first cavity and the second cavity. Therefore, the variation in the loading level of the active material slurry in the width direction with respect to the width of the slot outlet can be reduced. Furthermore, since the stagnation of the slurry in the first cavity and the second cavity can be minimized according to an embodiment, the uniformity of the flow rate of the slurry discharged to the slot outlet in the width direction can be ensured, thereby reducing the variation in the loading level of the active material slurry in the width direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is an exploded perspective view of a slot die for manufacturing electrodes of a rechargeable battery according to a first embodiment of the present disclosure.

[0029] Figure 2 is a top view of an intermediate block used in the Figure 1 slot die.

[0030] Figure 3 is a cross-sectional view taken along line III-III of the Figure 1 slot die.

[0031] Figure 4 is a cross-sectional view of a slot die for manufacturing electrodes of a rechargeable battery according to a second embodiment of the present disclosure.

[0032] Figure 5 is a perspective view of an intermediate block used in a slot die for manufacturing electrodes of a rechargeable battery according to a third embodiment of the present disclosure.

[0033] Figure 6Perspective view of an intermediate block used in a slit die for manufacturing a rechargeable battery electrode according to a fourth embodiment of the present disclosure.

[0034] Figure 7 Figure showing the stagnant state of the slurry in a slit die according to the conventional technique.

[0035] Figure 8 Figure showing the stagnant state of the slurry in a slit die according to a first embodiment of the present disclosure.

[0036] Figure 9 Image showing the uniformity of the loading level in the width direction of the electrode in the case of using a slit die according to a first embodiment of the present disclosure.

[0037] Figure 10 Image showing the uniformity of the loading level in the width direction of the substrate in the electrode in the case of using a slit die according to the conventional technique.

[0038] <Reference numeral description>

[0039] 1, 2: Slit die 10: First block

[0040] 11: First cavity 12: First inclined surface

[0041] 13: First planar groove 14: First connection channel

[0042] 15: Supply hole 20: Second block

[0043] 21: Second cavity 22: Second inclined surface

[0044] 23: Second planar groove 24: Second connection channel

[0045] 30: Third block 40: Spacer member

[0046] 41, 42: Inner surfaces at both ends 50: Slit outlet

[0047] 61: Backup roller 62: Substrate

[0048] 220: Second block 221: Second cavity

[0049] 222: Concave inclined surface 320: Intermediate block

[0050] 321: Second cavity 420: Intermediate block

[0051] 421: Second cavity L1: Dimension

[0052] L2: Distance L21: Dimension

[0053] L41: Minimum distance L42: Maximum distance

[0054] L50: Distance L51: Maximum distance

[0055] L52: Minimum distance L250: Distance

[0056] S: Active material paste θ1: First angle

[0057] θ2: Second angle Detailed implementation manners

[0058] In the following, with reference to the accompanying drawings, various implementation manners of the present disclosure will be described in detail, so that those of ordinary skill in the art can easily practice the present disclosure in the technical field to which the present disclosure belongs. As those skilled in the art will recognize, the described implementation manners can be modified in various different ways, and all such modifications do not depart from the spirit or scope of the present invention. The drawings and the description are considered to be illustrative in nature and not restrictive. Throughout the specification, the same reference numerals denote the same elements.

[0059] Figure 1 is an exploded perspective view of a slit die for manufacturing a rechargeable battery electrode according to a first implementation manner of the present disclosure, Figure 2 is used in Figure 1 a top view of an intermediate block in the slit die of Figure 3 is a cross-sectional view taken along line III-III of Figure 1 of

[0060] Referring to Figures 1 to 3 , a slit die (hereinafter referred to as the slit die) for manufacturing a rechargeable battery electrode according to the first implementation manner includes a first block 10, a second block 20 on the first block 10, a third block 30 disposed opposite to the second block 20, and a gasket member 40 disposed between the second block 20 and the third block 30.

[0061] The gasket member 40 installed between the second block 20 and the third block 30, the first block 10, the second block 20, and the third block 30 can be fastened with fastening members (not shown) to form the slit die 1. As a reference, the fastening holes through which the fastening members pass are shown in the first block 10, the second block 20, the third block 30, and the gasket member 40.

[0062] The gasket member 40 is disposed between the second block 20 and the third block 30 to form a slit outlet 50 in a plane (x-z plane) in the width direction (x-axis direction) and the height direction (z-axis direction). The slit die 1 applies the active material paste S discharged through the slit outlet 50 to the substrate 62. The substrate advances while being supported by the backup roll 61, while allowing the active material paste S to be applied.

[0063] In the width direction (x-axis direction), the width refers to the width of the substrate 62 coated with the slit die 1 and the width of the slit outlet 50 corresponding to this width. The width of the substrate 62 is perpendicular to the moving direction of the substrate 62.

[0064] For the purpose of single cell encapsulation of rechargeable batteries, it is generally necessary to minimize the variation in the loading level in the width direction (x-axis direction) of the substrate 62 and the slit outlet 50. That is, in order to increase the cell capacity of rechargeable batteries, it is generally necessary to minimize the variation in the loading level in the width direction (x-axis direction) of the substrate 62 and the slit outlet 50. In order to reduce the variation in the loading level in the width direction, the flow rate of the active material slurry discharged from the slit die 1 needs to be uniform in the width direction.

[0065] To this end, in addition to the first chamber 11, the slit die 1 of the first embodiment further has a second chamber 21. In other words, the active material slurry passing through the first chamber 11 is discharged to the slit outlet 50 via the second chamber 21 having a height difference (difference in the z-axis direction). Therefore, as the active material slurry advances sequentially, the flow rate of the active material slurry becomes more uniform in the width direction (x-axis direction).

[0066] Even when the first chamber 11 and the second chamber 21 are provided, a stagnant section of the active material slurry may be formed inside the first chamber 11 and the second chamber 21, and slurry precipitation may occur in the stagnant section. The precipitated slurry changes the size and shape of the first chamber 11 and the second chamber 21, which may have a negative impact on the slurry flow rate. Therefore, the first embodiment has a structure for reducing the precipitation of the active material slurry inside the first chamber 11 and the second chamber 21.

[0067] Specifically, the first block 10 is provided with the first chamber 11, and the first chamber 11 is formed to temporarily accommodate the supplied active material slurry. The first block 10 is provided with a supply port 15 at the bottom and is connected to a slurry pump (not shown) that supplies the active material slurry. Therefore, the active material slurry is supplied to the first chamber 11 through the supply port 15.

[0068] The first chamber 11 has an inner surface along a semi-circular curve in the y-z cross-section to minimize or prevent the precipitation of the active material slurry. The first chamber 11 is formed long in the width direction (x-axis direction) and further includes a first inclined surface 12 that slopes upward at a first angle θ1 toward the slit outlet 50, and the first inclined surface 12 extends from one curved surface of the inner surface of the semi-circular curve toward the second block 20. The semi-circular curve and the first inclined surface 12 continuing from the curve can further reduce the precipitation of the active material slurry.

[0069] The first connection channel 14 is formed between the first block 10 and the second block 20. The first inclined surface 12 in the first cavity 11 is connected to the first planar groove 13 formed on the upper surface of the first block 10. The first planar groove 13 includes a flat surface on the concave inner surface.

[0070] The first planar groove 13 is formed in the front-rear direction (y-axis direction) and the width direction (x-axis direction) intersecting the front-rear direction, and is connected to the first inclined surface 12 of the first cavity 11. Therefore, the first connection channel 14 is defined as the space between the first planar groove 13 and the lower surface of the second block 20 placed on the first planar groove 13. In other words, the first connection channel 14 forms an open space on the upper surface of the first block 10 having a cross-section in the width direction (x-axis direction) and the height direction (z-axis direction), such that the active material slurry can advance in the y-axis direction.

[0071] The second block 20 forms a second cavity 21 that receives the active material slurry supplied through the first connection channel 14 and discharges it to the slit outlet 50. That is, the second block 20 is placed on the first block 10 to establish the second cavity 21, and the first connection channel 14 is established between the first block 10 and the second block 20. Therefore, the second cavity 21 is provided at a position higher (in the z-axis direction) than the first cavity 11.

[0072] The second cavity 21 is connected to the first cavity 11 through the first connection channel 14, and the lower side of the second cavity 21 is defined by the first planar groove 13. Therefore, the active material slurry supplied from the first cavity 11 to the first connection channel 14 travels from the bottom to the top of the second cavity 21 through the first planar groove 13 and fills the second cavity 21. That is, in the height direction (z-axis direction) of the slit die 1, the first cavity 11 is provided below the second cavity 21.

[0073] The second cavity 21 penetrates the second block 20 in the vertical direction and is formed to have a length corresponding to the first cavity 11 in the width direction (x-axis direction). Therefore, the active material slurry supplied from the first cavity 11 can be supplied to the second cavity 21 through the first connection channel 14 in the entire width direction (x-axis direction).

[0074] The second cavity 21 has an inclined inner surface in the y-z cross-section to minimize and prevent precipitation of the active material slurry. The second cavity 21 is formed long in the width direction (x-axis direction) to form a space for receiving the active material slurry, and further includes a second inclined surface 22 that slopes upward at a second angle θ2 toward the slit outlet 50 in the direction toward the third block 30. The second inclined surface 22 of the second cavity 21 is used to further minimize and prevent precipitation of the active material slurry in the second cavity 21.

[0075] In an exemplary embodiment, the second angle θ2 has the same magnitude as the first angle θ1 to prevent and minimize precipitation of the active material slurry on either side of the first chamber 11 and the second chamber 21.

[0076] The second connection channel 24 is formed between the second block and the third block 30. In the second chamber 21, the second inclined surface 22 is connected to a second planar groove 23 formed on the upper surface of the second block 20. The second planar groove 23 includes a flat surface on the concave inner surface. With respect to the plane in the x-y direction, the second chamber 21 forms a minimum area at the portion connected to the first planar groove 13, and this area gradually increases upward (z direction) along the second inclined surface 22.

[0077] The second planar groove 23 is formed in the front-rear direction (y-axis direction) and the width direction (x-axis direction) intersecting the front-rear direction, and is connected to the second inclined surface 22 of the second chamber 21. Accordingly, the second connection channel 24 is defined as the space between the inner surfaces 41 and 42 at both ends of the gasket member 40, the second planar groove 23, and the lower surface of the third block 30 provided above the second planar groove 23. In other words, the second connection channel 24 forms an open space having a cross-section in the width direction (x-axis direction) and the height direction (z-axis direction) on the upper surface of the second block 20, so that the active material slurry can advance in the y-axis direction.

[0078] In a plane (x-y plane) extending in the width direction (x-axis direction) and the front / rear direction (y-axis direction), the second chamber 21 forms an opening in the front-rear direction. The opening has the same dimension L1 in the front-rear direction (y-axis direction) in the width direction (x-axis direction), and the distance L2 from the opening of the second chamber 21 to the slit outlet 50 is uniform in the width direction (x-axis direction).

[0079] The slit die 1 of the first embodiment is compared with a slit die having at least one of the above configurations in which the first chamber 11 and the second chamber 21, the first inclined surface 12 and the second inclined surface 22, and the first connection channel 14 and the second connection channel 24 are not provided. Compared with other slit dies, the slit die 1 of the first embodiment makes the flow rate of the active material slurry discharged to the slit outlet 50 more uniform in the entire width direction (x-axis direction).

[0080] In addition, the slit outlet 50 is connected to the second connection channel 24 and is defined as an open area between the inner surfaces 41 and 42 at both ends in the width direction (x-axis direction) of the gasket member 40 between the upper surface of the second block 20 and the lower surface of the third block 30 in the height direction (z-axis direction).

[0081] In addition, in the cross-section (yz) in the front-back direction (y-axis direction) and the up-down direction (z-axis direction) that intersects with the width direction (x-axis direction), the cross-section of the first chamber 11 is larger than that of the second chamber 21. Therefore, when the active material slurry moves from the first chamber 11 to the second chamber 21, precipitation can be prevented due to the decrease in supply pressure.

[0082] In the first embodiment, the first chamber 11 and the second chamber 21 are connected through the first connection channel 14 and the second connection channel 24, so that the stagnation of the slurry in the first chamber 11 and the second chamber 21 can be minimized. Therefore, according to the first embodiment, the change in the loading level of the active material slurry in the width direction of the slit outlet 50 can be reduced, and the single-cell capacity of the rechargeable battery can be improved.

[0083] Hereinafter, various embodiments of the present disclosure will be described. Configurations that are the same as those in the previously described embodiments will be omitted, and different configurations will be described.

[0084] Figure 4 is a cross-sectional view of a slit die 2 for manufacturing a rechargeable battery electrode according to a second embodiment of the present disclosure. Refer to Figure 4 , in the slit die 2 according to the second embodiment, the second chamber 221 penetrates the second block 220 in the up-down direction and is formed long in the width direction (x-axis direction) and has a length corresponding to that of the first chamber 11. Therefore, the active material slurry supplied from the first chamber 11 can be simultaneously supplied to the second chamber 221 across the entire width direction (x-axis direction) through the first connection channel 14.

[0085] The second chamber 221 has an inclined inner surface in the y-z cross-section to minimize and prevent the precipitation of the active material slurry. The second chamber 221 is formed long in the width direction (x-axis direction) to form a space for receiving the active material slurry. The second chamber 221 includes a concave inclined surface 222 that slopes upward (z-axis direction) toward the slit outlet 50 and the third block 30. The concave inclined surface 222 is formed to be connected to the slit outlet 50. The concave inclined surface 222 of the second chamber 221 is used to further minimize and prevent the precipitation of the active material slurry in the second chamber 221.

[0086] In addition, the slit outlet 50 is connected to the concave inclined surface 222 and is defined by the upper surface of the second block 220 extending in the front-back direction (y-axis direction) in the width direction (x-axis direction), the inner surfaces 41 and 42 at both ends of the gasket member 40, and the bottom surface of the third block 30 provided on the second chamber 221.

[0087] The concave inclined surface 222 of the second cavity 221 does not require a separate configuration corresponding to the second connection channel 24 of the first embodiment. The upper end of the concave inclined surface 222 serves as the second connection channel 24 of the first embodiment, enabling the active material slurry to advance in the y-axis direction.

[0088] In the second embodiment, the first cavity 11 and the second cavity 221 are connected through the first connection channel 14, and the second cavity 221 is provided with a concave inclined surface 222. Therefore, the stagnation of the slurry in the first cavity 11 and the second cavity 221 can be minimized. Thus, according to the second embodiment, the change in the loading level of the active material slurry in the width direction of the slit outlet 50 can be reduced, and the monomer capacity of the rechargeable battery can be increased.

[0089] Figure 5 is a perspective view of an intermediate block 320 (corresponding to the second block in the foregoing embodiments) used in a slit die for manufacturing a rechargeable battery electrode according to a third embodiment of the present disclosure. Refer to Figure 5 In the intermediate block 320 used in the slit die according to the third embodiment, in a plane (x-y plane) extending in the width direction (x-axis direction) and the front-rear direction (y-axis direction) intersecting the width direction, the second cavity 321 is formed with an opening having the same dimension L21 in the front-rear direction, and the distance L50 from the second cavity 321 to the slit outlet 50 has a maximum distance L51 in the middle of the width direction (y-axis direction) and a minimum distance L52 at both ends of the width direction.

[0090] Compared with other parts, the maximum distance L51 in the middle of the width direction of the slit outlet 50 can effectively respond to the faster flow rate of the active material slurry. That is, the flow rate of the active material slurry has the maximum flow rate at the maximum distance L51 of the slit outlet 50 and the minimum flow rate at the minimum distance L52. This difference in the distances L51 and L52 minimizes and prevents the difference in the flow rate. Therefore, the maximum distance L51 and the minimum distance L52 of the second cavity 321 and the distances varying between the maximum distance L51 and the minimum distance L52 can further minimize and prevent the precipitation of the active material slurry in the second cavity 321.

[0091] In addition, according to the third embodiment, the stagnation of the slurry in the first cavity 11 and the second cavity 321 can be minimized, ensuring the uniformity of the flow rate of the slurry discharged to the slit outlet 50 in the width direction (x-axis direction), so that the change in the loading level of the active material slurry can be reduced, and the monomer capacity of the rechargeable battery can be increased.

[0092] Figure 6is a perspective view of an intermediate block 420 used in a slit die for manufacturing a rechargeable battery electrode according to a fourth embodiment of the present disclosure. Referring to Figure 6 , in the intermediate block 420, on a plane (x-y plane) extending in the width direction (x-axis direction) and the front-rear direction (y-axis direction) intersecting the width direction, the second cavity 421 is formed with an opening having a width that gradually changes in the width direction. Accordingly, the distance L250 from the second cavity 421 to the slit outlet 50 has a maximum distance L51 at the middle in the width direction (x-axis direction) and a minimum distance L52 at both ends in the width direction.

[0093] In addition, the plane of the second cavity 421 forms an opening in the front-rear direction, having a minimum distance L41 at the middle in the width direction and a maximum distance L42 at both ends in the width direction. Therefore, the combination of the maximum distance L51 and the minimum distance L52 of the second cavity 321, the distance varying between the maximum distance L51 and the minimum distance L52, and the minimum distance L41 and the maximum distance L42 of the opening of the second cavity 421 is used to further minimize the precipitation of the active material slurry in the second cavity 321.

[0094] Furthermore, according to the fourth embodiment, the stagnation of the slurry in the first cavity 11 and the second cavity 421 can be minimized, thereby ensuring the uniformity of the flow rate of the slurry discharged to the slit outlet 50 in the width direction (x-axis direction), reducing the variation in the loading level of the active material slurry, and increasing the single-cell capacity of the rechargeable battery.

[0095] Figure 7 is a diagram showing the stagnation state of the slurry in a slit die according to the conventional technique. Referring to Figure 7 , in the slit die according to the conventional technique, the slurry movement path remains horizontal from the first cavity C1 to the slit outlet SO where the slurry is discharged. Therefore, the slurry flow rate is high only at the upper part of the second cavity C2, while the slurry flow rate is low at the lower part, resulting in a slurry stagnation section SSS. In addition, over time, slurry precipitation occurs in the slurry stagnation section at the bottom of the second cavity C2. This increases the variation in the loading level of the active material slurry and reduces the single-cell capacity of the rechargeable battery.

[0096] Figure 8 is a diagram showing the stagnation state of the slurry in a slit die according to the first embodiment of the present disclosure. Referring to Figure 8 , in the slit die 1 according to the first embodiment, the first cavity 11 is provided below the second cavity 21. Therefore, since the slurry passes through the second cavity 21 as a whole, the slurry stagnation section SSS at the bottom of the second cavity 21 can be minimized. As a result, the slurry precipitation in the second cavity 21 is reduced, and the loading level similar to the initial stage can be maintained even during the long-term production process of the battery electrodes.

[0097] Figure 9 is an image showing the uniformity of the loading level in the width direction of the electrode in the case of using the slot die according to the first embodiment of the present disclosure, Figure 10 is an image showing the uniformity of the loading level in the width direction of the substrate in the electrode in the case of using the slot die according to the conventional technique. Referring to Figure 9 and Figure 10 , the quality of the loading level of the electrode of the rechargeable battery manufactured with the slot die of the first embodiment can be compared with the quality of the loading level of the electrode of the rechargeable battery manufactured with the slot die having one cavity according to the conventional technique.

[0098] To verify this comparison, the slot die of the first embodiment and the slot die of the conventional technique are used in the same equipment, and the same active material slurry is supplied to each slot die through the same supply pipeline and is simultaneously coated on the substrate. The result of the comparison shows that, compared with the conventional technique, the first embodiment tends to have better uniformity of the loading level in the width direction of the substrate.

[0099] In Figure 9 , in the wet state of the moving substrate according to the first embodiment in the width direction (x-axis direction), the maximum loading level is 17.43 mg / cm 2 , and the minimum loading level is 17.16 mg / cm 2 . The difference between the maximum thickness and the minimum thickness, that is, the difference in the loading level in the width direction, results in a rechargeable battery electrode with a loading level change of 0.27 mg / cm 2 .

[0100] In Figure 10 , in the wet state of the moving substrate according to the conventional technique in the width direction (x-axis direction), the maximum loading level is 17.65 mg / cm 2 , and the minimum loading level is 17.23 mg / cm 2 . The difference between the maximum thickness and the minimum thickness, that is, the difference in the loading level in the width direction, results in a rechargeable battery electrode with a loading level change of 0.42 mg / cm 2 .

[0101] The difference in the loading level of the electrode of the rechargeable battery of the first embodiment (which is 0.27 mg / cm 2 ) is smaller than the difference in the loading level of the electrode of the rechargeable battery of the conventional technique (which is 0.42 mg / cm 2 ). Therefore, it can be seen that, in terms of the uniformity of the loading level of the electrode of the rechargeable battery in the width direction, the first embodiment is superior to the conventional technique.

[0102] In addition, a method for manufacturing an electrode of a rechargeable battery according to an embodiment can manufacture an electrode of a rechargeable battery by applying an active material slurry to a substrate using a slit die for manufacturing an electrode of a rechargeable battery.

[0103] Although the present invention has been described in connection with presently considered practical embodiments, it will be understood that the present invention is not limited to the disclosed embodiments. On the contrary, it is intended to cover various modifications and equivalent arrangements included within the scope of the description of the present disclosure and the appended claims and drawings.

Claims

1. A slot die for manufacturing a rechargeable battery electrode, the slot die comprising: The first piece; a second block disposed on the first block; a third block disposed opposite to the second block; as well as a spacer member disposed between the second block and the third block, the spacer member forming a slit outlet extending in the width direction and the height direction, wherein the first block forms a first cavity configured to receive the supplied active material slurry and form a connecting channel between the first block and the second block in the width direction and the height direction of the slit outlet, and The second block forms a second cavity for receiving the active material slurry supplied through the connecting channel, and discharges the received active material slurry through the slit outlet.

2. The slot die for manufacturing a rechargeable battery electrode according to claim 1, wherein: The first cavity extends in the width direction, the first cavity includes (i) a curved surface forming a space for receiving the active material slurry, and (ii) an inclined surface formed on one side of the curved surface and inclined upward toward the slit outlet, and Wherein the inclined surface is connected to a planar groove formed on an upper surface of the first block.

3. The slot die for manufacturing a rechargeable battery electrode according to claim 2, wherein: The planar groove extends in a front-rear direction intersecting the width direction and in the width direction, and the planar groove is connected to the inclined surface, and The connecting passage is defined as a space between the planar groove and a lower surface of the second block placed on the planar groove.

4. The slot die for manufacturing a rechargeable battery electrode according to claim 3, wherein: The second cavity penetrates the second block in a vertical direction and is formed with a length corresponding to that of the first cavity in the width direction.

5. The slot die for manufacturing a rechargeable battery electrode according to claim 4, wherein: The inclined surface is a first inclined surface, the second cavity includes a second inclined surface that is inclined upward toward the slit outlet, and Wherein the second inclined surface connects to the planar groove at the lower surface of the second block.

6. The slot die for manufacturing a rechargeable battery electrode according to claim 5, wherein: The connecting channel is a first connecting channel, and a second connecting channel is formed between the second block and the third block, wherein the second cavity extends in the width direction to form a space for receiving the active material slurry, and includes the second inclined surface formed on one side inclined upward toward the slit outlet, and Wherein the planar groove is a first planar groove, and the second inclined surface is connected to a second planar groove formed on an upper surface of the second block.

7. The slot die for manufacturing a rechargeable battery electrode according to claim 6, wherein: The second planar groove extends in the front-rear direction intersecting the width direction and in the width direction, and the second planar groove is connected to the second inclined surface, The second connection channel is defined as a space between inner surfaces of both ends of the gasket member, the second planar groove, and a lower surface of the third block placed on the second planar groove.

8. The slot die for manufacturing a rechargeable battery electrode according to claim 7, wherein: The slit outlet is connected to the second connection passage and is set between the upper surface of the second block and the lower surface of the third block in the height direction and between the inner surfaces of both ends of the spacer member in the width direction.

9. The slot die for manufacturing a rechargeable battery electrode according to claim 1, wherein A first cross-section of the first cavity in the vertical direction is larger than a second cross-section of the second cavity in the vertical direction.

10. The slot die for manufacturing a rechargeable battery electrode according to claim 1, wherein: The second cavity forms an opening having a uniform size in the front-rear direction and extending in the width direction, and Wherein a distance from the opening of the second cavity to the slit outlet is uniform in the width direction.

11. The slot die for manufacturing a rechargeable battery electrode according to claim 3, wherein: the second cavity penetrates the second block in the vertical direction and is formed to extend in the width direction by a length corresponding to a length of the first cavity in the width direction, and The second cavity is formed by a concave inclined surface that slopes upward toward the slit outlet.

12. The slot die for manufacturing a rechargeable battery electrode according to claim 11, wherein: The slit outlet is connected to the concave inclined surface, and The slit outlet is defined by an upper surface of the second block in the front-rear direction and the width direction, inner surfaces of both ends of the gasket member, and a lower surface of the third block disposed on the second cavity.

13. The slot die for manufacturing a rechargeable battery electrode according to claim 1, wherein: The second cavity forms an opening of uniform size in the width direction and in the front-rear direction, and The distance from the second cavity to the slit outlet is the largest in the middle of the second cavity in the width direction, and is the smallest at both ends of the second cavity in the width direction.

14. The slot die for manufacturing a rechargeable battery electrode according to claim 1, wherein: The second cavity forms an opening whose dimension in a front-rear direction intersecting the width direction varies in the width direction, and The distance from the second cavity to the slit outlet is the largest in the middle of the second cavity in the width direction, and is the smallest at both ends of the second cavity in the width direction.

15. The slot die for manufacturing a rechargeable battery electrode according to claim 13, wherein: The size of the opening formed by the second cavity in the front-rear direction is smallest in the middle of the second cavity in the width direction, and is largest at the both ends of the second cavity in the width direction. 16 . An electrode for a rechargeable battery, formed by applying an active material slurry to a substrate using the slit die for manufacturing a rechargeable battery electrode according to claim 1 .

17. The electrode for a rechargeable battery according to claim 16, wherein The substrate in a wet state has a thickness of 17.43 mg / cm in the width direction of the substrate. 2 The maximum slurry loading level and 17.16 mg / cm 2 Minimum slurry loading level. 18 . A method for manufacturing an electrode for a rechargeable battery, comprising manufacturing the electrode by applying an active material slurry to a substrate using the slot die for manufacturing an electrode for a rechargeable battery according to claim 1 .

Images