Electrode coating die and electrode coating device comprising same

Abstract

The present invention relates to an electrode coating die and an electrode coating device and, more specifically, to an electrode coating die and an electrode coating device having increased durability and service life. According to one embodiment of the present invention, an electrode coating die for applying and coating slurry on an electrode substrate of a secondary battery comprises: an upper body; a lower body coupled to the upper body; a slot formed between the upper body and the lower body so as to apply slurry toward the upper surface of the electrode substrate that is continuously transported; and a die lip provided at a lower end of the upper body and positioned in front of the slot to press the upper surface of the electrode substrate, thereby maintaining contact between the electrode coating die and the electrode substrate, wherein the die lip guides the transport of the electrode substrate by rolling with respect to the upper body.

Description

Electrode coating die and electrode coating device including the same

[0001] The present invention relates to an electrode coating die and an electrode coating device, and more specifically, to an electrode coating die and an electrode coating device with increased durability and service life.

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2024-0141413 filed on October 16, 2024, and all contents disclosed in the documents of said Korean patent application are incorporated herein as part of this specification.

[0003] Unlike primary batteries, which cannot be recharged, secondary batteries refer to batteries capable of charging and discharging, and are applied not only to portable devices but also to electric vehicles (EVs) and hybrid electric vehicles (HEVs) driven by electric power sources.

[0004] Currently, widely used types of secondary batteries include lithium-ion batteries, lithium-polymer batteries, nickel-cadmium batteries, nickel-hydrogen batteries, and nickel-zinc batteries. The operating voltage of these unit secondary battery cells, or unit battery cells, is approximately 25V to 46V. Therefore, if a higher output voltage is required, a battery module is formed by connecting multiple battery cells in series. Additionally, a battery module is formed by connecting multiple battery cells in parallel depending on the charge / discharge capacity required for the battery module. Accordingly, the number of battery cells included in the battery module can be varied depending on the required output voltage or charge / discharge capacity.

[0005] The electrodes of a secondary battery include a positive electrode and a negative electrode, and the electrodes can be manufactured by coating a positive or negative material on both sides of an electrode substrate, such as aluminum foil or copper foil. For mass production, it is common to manufacture electrodes using a roll-to-roll method.

[0006] After manufacturing the electrode roll, the positive electrode, separator, negative electrode, and separator are sequentially stacked to produce an electrode assembly in various ways and forms. The manufactured electrode assembly can be housed in a cylindrical, pouch, or prismatic case to produce a secondary battery of various forms.

[0007] Coater equipment is required to coat an electrode substrate by applying an anode or cathode material, and in particular, a die is used to apply an anode or cathode material in a slurry state to the electrode substrate. Such a die is also called a coater die or a slot die.

[0008] To coat the upper and lower surfaces of an electrode substrate and increase the productivity of electrode manufacturing, the upper and lower surfaces of the electrode can be manufactured using a single coating facility by utilizing a roll-to-roll process. That is, a series of processes in which one side of a continuously transported electrode substrate is coated first, then the other side is coated, and the electrode is dried after coating can be continuously performed through the roll-to-roll process.

[0009] Figure 1 illustrates the concept of an example of a conventional electrode coating.

[0010] The electrode substrate (10) in roll state is continuously transported from the unwinder and coating is performed.

[0011] First, a coating roll (30) and a back coating die (20) are provided to apply a slurry to the lower surface of an electrode substrate for coating. The electrode substrate (10) moves while in contact with the coating roll (30), and at this time, the coating roll (30) also rotates. The back coating die (20) is positioned in the normal direction of the coating roll (30) and is fixed at a constant distance from the coating roll (30).

[0012] Accordingly, the coating roll (30) performs the function of a table that supports the electrode substrate to be coated, and the back coating die (20) performs coating by continuously applying a slurry toward the lower surface, i.e., the back, of the electrode substrate (10).

[0013] The back-coated electrode substrate is continuously transported and can have its upper surface coated by passing through a support roller (50). At the position or time when the upper surface of the electrode substrate is coated, the lower surface of the electrode substrate is coated with a slurry. Therefore, it is not easy to physically support the lower surface of the electrode substrate while the slurry is not completely dried.

[0014] For this reason, the electrode substrate is not supported at the location where the slurry is applied to the upper surface of the electrode substrate. That is, since the electrode substrate is not supported on the coating roll or support table, it is important to ensure that the top coating die (40) and the electrode substrate (10) are always in contact.

[0015] As described above, during top coating, the lip portion of the top coating die maintains contact with the upper surface, i.e., the top, of the electrode substrate while the coating is performed. At this time, since the electrode substrate is continuously transported, the lip portion of the top coating die wears down, inevitably reducing the die life. Therefore, the entire top coating die is replaced at regular intervals.

[0016] Replacing the entire top coating die takes a significant amount of time, and resetting it may also require additional time. Consequently, the entire electrode coating line must be shut down during the die replacement process. This leads to problems such as reduced productivity and increased manufacturing costs.

[0017] The present invention aims to solve the problems of conventional coating dies and coating devices including the same.

[0018] Through one embodiment of the present invention, we aim to provide a coating die and a coating apparatus including the same that improve durability and reliability by reducing the frictional force between the lip of the die and the electrode substrate.

[0019] Through one embodiment of the present invention, we aim to provide a coating die and a coating apparatus including the same that can solve the problems of reduced productivity and increased manufacturing costs caused by die replacement by making it possible to replace only a part of the die, namely the lip portion, rather than the entire die.

[0020] Through one embodiment of the present invention, we aim to provide a die having a lip that contacts an electrode substrate being continuously conveyed through rolling, and to provide a coating die and a coating apparatus including the same that facilitates easy mounting and replacement of the lip.

[0021] Through one embodiment of the present invention, by providing a die having a lip that maintains contact with an electrode substrate through rolling on the upstream side of a slot from which a slurry is discharged, the spacing between the slot and the electrode substrate can be accurately maintained and the slurry can be applied stably, and the present invention aims to provide a coating die and a coating apparatus including the same.

[0022] In order to achieve the objective of the present invention, according to one embodiment of the present invention, an electrode coating die for coating a secondary battery electrode substrate by applying a slurry is provided, comprising: an upper body; a lower body coupled to the upper body; a slot formed between the upper body and the lower body to apply a slurry toward the upper surface of an electrode substrate being continuously transported; and a die lip provided at the lower end of the upper body and positioned in front of the slot to press the upper surface of the electrode substrate to maintain contact between the electrode coating die and the electrode substrate, wherein the die lip guides the transport of the electrode substrate by rolling relative to the upper body.

[0023] A die lip refers to a part that is formed to protrude at the front and rear of the above slit, respectively, and protrudes from the upper body and the lower body, respectively, and a slit may be formed between the protruding die lips.

[0024] The upper body and the lower body of the electrode coating die described above can be distinguished according to their vertical position or according to their vertical position. For example, the body located on the upstream side can be referred to as the upper body, and the body located on the downstream side can be referred to as the lower body.

[0025] According to the present embodiment, among the two die lips, a die lip located particularly at the front of the slot and in direct contact with an electrode substrate being transported from the front to the rear can be provided to be rollable. The electrode substrate moves from the front to the rear of the slot, and the slot supplies a slurry to the moving electrode substrate. Accordingly, the front of the slot can be considered the upstream side of the slot, and the rear of the slot can be considered the downstream side of the slot.

[0026] Since a die lip is provided at the front, or upstream, side of the slot to maintain contact with the electrode substrate by rolling, interference between the die lip and the discharged slurry can be eliminated.

[0027] The die lip is detachably provided on the upper body, and the lowest end of the die lip may be positioned to protrude further downward than the lowest end of the upper body.

[0028] It is preferable that the lowest end of the die lip protrudes further downward than the lowest end of the lower body. Accordingly, it is preferable that the upper body does not come into contact with the electrode substrate, and only the die lip comes into contact with and maintains contact with the electrode substrate.

[0029] The above die lip may include a lip rod that is rotatably provided relative to the main body by contact frictional force with the electrode substrate.

[0030] It may include bearings that rotatably support both ends of the above-mentioned rib bar. It is preferable that the bearings be mounted and fixed to both ends of the upper body.

[0031] It is preferable that the above-mentioned lip bar be formed as a single bar integrally provided in the longitudinal direction of the main body. Accordingly, the mounting and detachment of the die lip can be easily performed through the mounting and detachment of the single bar.

[0032] It is preferable that the length of the single rod be formed to be longer than the length of the main body. This facilitates the mounting and detachment of the single rod, and also enables stable contact with the electrode substrate, maintenance of contact, and guidance of the electrode substrate's transport.

[0033] The above-mentioned lip rod is preferably provided so as to be detachably mounted in a mounting groove formed along the longitudinal direction of the main body, and the contact surface of the lip roller that contacts the electrode substrate is mounted so as to protrude from the mounting groove.

[0034] It is desirable that a large portion of the rib bar be surrounded by a mounting groove in the outer circumference direction, with only a portion protruding from the mounting groove. Accordingly, the rib bar can be stably mounted and operated.

[0035] It is preferable that the mounting groove be provided with a plurality of support rollers at predetermined intervals along the longitudinal direction of the mounting groove so as to rotatably support the rib bar.

[0036] It is preferable that the above support rollers be provided in multiple numbers at predetermined intervals along the circumferential direction of the mounting groove.

[0037] To achieve the objective of the present invention, according to one embodiment of the present invention, an electrode coating device may be provided comprising: a coating roll provided to support the upper surface of an electrode substrate that is continuously conveyed while rotating; a back coating die provided adjacent to the coating roll and applying a slurry through a slot toward the lower surface of the electrode substrate supported by the coating roll; and a top coating die provided at the rear end of the coating roll and applying a slurry through a slot toward the upper surface while pressing the upper surface of the electrode substrate, wherein the top coating die includes a die lip located in front of the slot and guiding the pressing and conveying of the electrode substrate by rolling.

[0038] The electrode coating device described above may include an unwinder that continuously supplies an electrode substrate in a roll state and a rewinder that continuously recovers the electrode substrate after coating is completed and converts it into a roll state.

[0039] The coating roll, back coating die, and top coating die are provided between the unwinder and the rewinder, and various rolls may be provided in addition to the coating roll. For example, a dancer roll for controlling the tension of the electrode substrate may be provided, and a plurality of support rolls and driving rolls may be provided.

[0040] In addition, the electrode coating device may include a drying device for drying the applied slurry, and furthermore, may include a rolling device for rolling the dried electrode.

[0041] It is preferable that the electrode substrate is supported in a direction opposite to the application direction of the electrode substrate at the location where the slurry is applied to the lower surface of the electrode substrate, and that the electrode substrate is not supported in a direction opposite to the application direction of the electrode substrate at the location where the slurry is applied to the upper surface of the electrode substrate. This is because it is not desirable to physically support a slurry that has not yet been dried. For this reason, in order to maintain a constant gap between the electrode substrate and the top coating die, it is preferable that the slurry be applied while the die lip of the top coating die maintains contact with the electrode substrate.

[0042] The top coating die comprises an upper body and a lower body coupled to the upper body to form the slot between the upper body and the lower body, and preferably the die lip is detachably provided at the bottom of the upper body.

[0043] It is preferable that the above die lip includes a lip rod that is rotatably provided with respect to the upper body by means of contact frictional force with the electrode substrate.

[0044] It is preferable to include bearings provided at both ends of the upper body to rotatably support both ends of the rib bar; and a plurality of support rollers provided at predetermined intervals along the longitudinal direction of the rib bar to rotatably support the rib bar.

[0045] The bearings are mounted at both ends of the main body of the top coating die, and it is preferable that the support rollers are provided in multiple numbers at regular intervals along the longitudinal direction inside the mounting grooves formed in the main body.

[0046] Therefore, the rib bar can be rolled while being stably supported overall. In addition, since the rib bar is easy to install and remove, the time required to replace the rib bar can be significantly reduced compared to replacing the entire top coating die.

[0047] Through one embodiment of the present invention, a coating die and a coating apparatus including the same can be provided, which improve durability and reliability by reducing the frictional force between the lip of the die and the electrode substrate.

[0048] Through one embodiment of the present invention, a coating die and a coating device including the same can be provided, which can solve the problems of reduced productivity and increased manufacturing costs caused by die replacement by making it possible to replace only a part of the die, namely the lip portion, rather than the entire die.

[0049] Through one embodiment of the present invention, a die having a lip that contacts an electrode substrate being continuously conveyed through rolling is provided, and a coating die and a coating device including the same can be provided in which mounting and replacement of the lip is easy.

[0050] Through one embodiment of the present invention, by providing a die having a lip that maintains contact with an electrode substrate through rolling on the upstream side of a slot from which a slurry is discharged, a coating die and a coating apparatus including the same can be provided, which can accurately maintain the gap between the slot and the electrode substrate and also stably apply the slurry.

[0051] FIG. 1 is a conceptual diagram of a conventional electrode coating device, and

[0052] FIG. 2 is a perspective view of an electrode coating die according to an embodiment of the present invention, and

[0053] Figure 3 is a side view of an electrode coating die, and

[0054] Figure 4 is a cross-sectional view of an electrode coating die, and

[0055] Figure 5 illustrates a mounting groove in which a die lip is mounted and a roller provided in the mounting groove.

[0056] Hereinafter, a coating die according to an embodiment of the present invention and a coating apparatus including the same will be described in detail with reference to the attached drawings.

[0057] The coating die and coating device according to the present embodiment are similar to the coating die and coating device illustrated and described in FIG. 1. However, the lip structure of the die may differ from the conventional lip structure, and a very significant effect can be expected due to this difference.

[0058] FIG. 2 illustrates an example of a coating die according to an embodiment of the present invention. A coating device or coating facility in which the coating die (50) shown in FIG. 2 replaces the top coating die (40) shown in FIG. 1 may also be considered an embodiment of the present invention.

[0059] FIG. 3 shows a side view of a coating die, FIG. 4 shows a cross-section (AA' cross-section) of the middle part of the coating die, and FIG. 5 shows a cross-section (BB' cross-section) showing the shape of a mounting groove.

[0060] The coating die (50) is a device for coating by applying a slurry to an electrode substrate of a secondary battery, and may include an upper body (51) and a lower body (52). The upper body (51) and the lower body (52) may be combined to form a single coating die or a coating die body.

[0061] Depending on the installation configuration of the coating die (50), the upper body and the lower body may be referred to as the front body and the rear body, respectively.

[0062] The upper body (51) and the lower body (52) are combined to form a fine gap between them, which can be called a slit or slot (53). Generally, slurry flowing into the body through the upper body (51) is discharged through the slot (53) to apply the slurry to the electrode substrate.

[0063] A shim is interposed between the upper body (51) and the lower body (52), through which the height of the slot (53) can be defined and the width of the discharged slurry can also be defined.

[0064] The coating die (50) according to the present embodiment is preferably not a back coating die, for example, a coating die that applies a slurry in a non-contact state with the electrode substrate being transported, but a top coating die, for example, a coating die that applies a slurry in a contact state with the electrode substrate being transported. Of course, depending on whether the transport direction of the electrode substrate changes or which of the two sides of the electrode substrate is defined as the top surface, the coating die (50) according to the present embodiment may be a top coating die.

[0065] When the electrode substrate is transported horizontally, the coating die (50) is installed in the state shown in FIG. 3 and can apply the slurry substantially vertically downward.

[0066] According to the present embodiment, the die (55) is not integrally formed with the upper body (51) or the lower body (52), but can be rotatably formed with respect to the upper body (51) or the lower body (52).

[0067] When the die lip (55) is provided on the upper body (51) based on FIG. 3, the electrode substrate is pressed downward by the die lip (55) and maintains contact with the die lip (55). A slurry can be applied from the rear of the die lip (55).

[0068] The die lip (55) can guide the transport of the electrode substrate by rolling against the upper body (51). That is, the die lip (55) continues to roll against the upper body (51) by the electrode substrate being transported while in contact with the die lip (55). Through this, the frictional force between the die lip (55) and the electrode substrate is reduced, and the entire circumferential surface of the die lip (55), rather than a specific part of the die lip (55), rotates and comes into contact with the electrode substrate. Therefore, wear and damage to the die lip can be significantly reduced.

[0069] The coating die (50) is formed in a shape with a long width or length corresponding to the width of the electrode substrate. Due to the shim, the slurry is not discharged from the slots at both ends of the coating die (50). That is, uncoated portions are formed at both ends of the electrode substrate.

[0070] Here, it is preferable that the width of the coating die (50) is greater than the width of the electrode substrate. In particular, in the case of a coating die that discharges a slurry while maintaining contact with the electrode substrate, it is preferable that both ends of the coating die (50) be installed extending outward from both ends of the electrode substrate in order to ensure stable contact with the electrode substrate and to prevent shaking and twisting of the electrode substrate.

[0071] For this reason, it is preferable that the die lip (55) includes a round bar (56) that is integrally formed and rolls while in contact with the electrode substrate. Such a round bar can be called a lip round bar.

[0072] The die lip (55), particularly the round bar (56), is detachably provided on the upper body, and it is preferable that the bottom end of the die lip (55) protrudes further downward than the bottom end of the upper body. Additionally, it is preferable that the bottom end of the die lip protrudes further downward than the bottom end of the lower body. Accordingly, the electrode material comes into contact only with the die lip (55), particularly the round bar (56), provided on the upper body, and does not come into contact with the lower body (52).

[0073] It is preferable that the above-mentioned round bar (55) be integrally provided in the longitudinal direction of the main body, particularly the upper main body (51). That is, it is preferable that it be provided as a continuous single round bar. Accordingly, it is easy to attach and detach the round bar (55) in the longitudinal direction of the main body, and also easy to form a structure that rotatably supports the round bar on the upper main body (51).

[0074] Here, it is preferable that the round bar (55) be mounted by penetrating the upper body (51) in the longitudinal direction. That is, both ends or one end may be mounted so as to protrude laterally from the upper body. Additionally, bearings (57) are provided at both ends of the round bar (55), and the round bar may be rotatably supported through the bearings (57).

[0075] The above bearing (57) is provided at both ends of the upper body (51), and at least one bearing (57) can be easily detachably provided on the upper body (51) to facilitate the attachment and detachment of the round bar (55).

[0076] Referring to FIGS. 4 and FIGS. 5, the mounting structure of the rib bar (56) will be described in detail.

[0077] A mounting groove (58) is formed in the upper body (51). The mounting groove (58) is formed in the front or lower part of the upper body (51) and can be formed to penetrate the upper body (51). Since a rib bar (55) in the shape of a round bar is mounted in the mounting groove (58), the mounting groove (58) is formed to correspond to the cross-sectional shape of the rib bar. At this time, it is preferable that a part of the rib bar (55) is formed to be exposed to the outside of the mounting groove (58). That is, it is preferable that the mounting groove (58) is formed in a structure in which the entire outer surface of the rib bar (55) is inserted and mounted, rather than a structure in which a part of the outer surface of the rib bar (55) is wrapped and a part is exposed. In other words, an opening is formed in the mounting groove (58), and a part of the rib bar (55) can protrude and be exposed through this opening.

[0078] The portion of the above-mentioned lip rod (55) that protrudes and is exposed from the mounting groove (58) forms the lowest or foremost part of the upper body (51) and can come into direct contact with the electrode substrate.

[0079] When the rib bar (55) is mounted in the mounting groove (58), both ends of the rib bar (55) are rotatably supported through the bearing (57). Since the length of the rib bar (55) must be formed to be relatively long in correspondence with the width of the electrode substrate, support is also required for the central part of the rib bar (55). This is because if an external force is applied to the central part of the rib bar (55), the rib bar will bend, making it difficult to perform smooth rotation, i.e., rolling.

[0080] Accordingly, it is preferable that a roller (59) is provided in the central portion, excluding both ends of the rib bar (55), to rotatably support the rib bar (55). Here, it is preferable that the roller (59) itself be inserted and mounted in the mounting groove (58). Accordingly, the roller (59) is rotatably provided with respect to the upper body, and a part of it may be embedded inside the upper body and a part of it may be provided protruding into the mounting groove (58).

[0081] It is preferable that the above rollers (59) be provided in multiple numbers to stably support the ribbed bar (55) in a rotatable manner. Additionally, it is preferable that the rollers (59) be provided in multiple numbers to form multiple support points in the outer circumference direction of the ribbed bar (55).

[0082] For example, a pair of rollers (59) may support a 90-degree point of the ribbed bar, another pair of rollers (59) may support a 30-degree point of the ribbed bar, and yet another pair of rollers (59) may support a 150-degree point of the ribbed bar. That is, a plurality of rollers or pairs of rollers may be provided at regular intervals along the outer circumference of the ribbed bar.

[0083] Additionally, multiple rollers (59) may be provided along the longitudinal direction of the ribbed bar. Rollers may be arranged at regular intervals along the longitudinal direction of the ribbed bar.

[0084] In the drawings describing the aforementioned embodiments, components such as ribbed rods or bearings are depicted in a size somewhat exaggerated compared to their actual applicability to explain the features in the embodiments.

[0085] According to the coating die of the above-described embodiment, it is not necessary to replace the coating die in order to replace the die lip. That is, while the coating die is installed, it is possible to separate and replace only the lip bar without separating the coating die. Therefore, maintenance is very easy, and in particular, the time required for maintenance can be significantly reduced, thereby significantly increasing the productivity of the electrode manufacturing process.

[0086] As described in the detailed description of the invention.

Claims

1. An electrode coating die for coating a secondary battery by applying a slurry to an electrode substrate, Upper body; A lower body coupled to the upper body above; A slot formed between the upper body and the lower body to apply a slurry toward the upper surface of an electrode substrate being continuously transported; It comprises a die lip provided at the bottom of the upper body and positioned in front of the slot to press the upper surface of the electrode substrate to maintain contact between the electrode coating die and the electrode substrate, An electrode coating die characterized in that the above die lip guides the transport of the electrode substrate by rolling with respect to the upper body.

2. In Paragraph 1, An electrode coating die characterized in that the die lip is detachably provided on the upper body, and the lowest end of the die lip is positioned to protrude further downward than the lowest end of the upper body.

3. In Paragraph 2, An electrode coating die characterized in that the lowest end of the die lip is positioned to protrude further downward than the lowest end of the lower body.

4. In Paragraph 3, The electrode coating die is characterized by the above die lip including a lip rod that is rotatably provided relative to the main body by contact frictional force with the electrode substrate.

5. In Paragraph 4, An electrode coating die characterized by including bearings that rotatably support both ends of the above-mentioned rib bar.

6. In Paragraph 5, The electrode coating die is characterized in that the above-mentioned rib bar is formed as a single rod integrally provided in the longitudinal direction of the above-mentioned main body.

7. In Paragraph 6, An electrode coating die characterized in that the length of the single rod is formed to be longer than the length of the main body.

8. In Paragraph 6, An electrode coating die characterized in that the above-mentioned lip rod is detachably provided in a mounting groove formed along the longitudinal direction of the main body, and the contact surface of the above-mentioned lip roller that contacts the electrode substrate is mounted to protrude from the mounting groove.

9. In Paragraph 8, An electrode coating die characterized in that the mounting groove is provided with a plurality of support rollers at predetermined intervals along the longitudinal direction of the mounting groove to rotatably support the lip rod.

10. In Paragraph 9, An electrode coating die characterized by the fact that the above support rollers are provided in plurality at predetermined intervals along the circumferential direction of the mounting groove.

11. A coating roll provided to support the upper surface of an electrode substrate that is continuously transported while rotating; A back coating die provided adjacent to the coating roll and applying a slurry through a slot toward the lower surface of the electrode substrate supported by the coating roll; and It comprises a top coating die provided at the rear end of the coating roll, which applies a slurry through a slot toward the upper surface while pressing the upper surface of the electrode substrate. An electrode coating device characterized in that the top coating die includes a die lip positioned in front of the slot to guide the pressing and transport of the electrode substrate by rolling.

12. In Paragraph 11, At the location where the above slurry is applied to the lower surface of the electrode substrate, the electrode substrate is supported in a direction opposite to the application direction of the electrode substrate, and An electrode coating apparatus characterized by the electrode substrate being unsupported in a direction opposite to the application direction of the electrode substrate at a location where the slurry is applied to the upper surface of the electrode substrate.

13. In Paragraph 12, The above top coating die comprises an upper body and a lower body coupled to the upper body to form the slot between the upper body and the lower body, and An electrode coating device characterized in that the above-described die lip is detachably provided at the bottom of the above-described upper body.

14. In Paragraph 13, The electrode coating device is characterized by the above die lip including a lip rod that is rotatably provided relative to the upper body by contact frictional force with the electrode substrate.

15. In Paragraph 14, Bearings provided at both ends of the upper body to rotatably support both ends of the above-mentioned rib bar; and An electrode coating device characterized by including a plurality of support rollers provided at predetermined intervals along the longitudinal direction of the rib bar to rotatably support the rib bar.

Images