Inclined movement prevention type drying chamber device for electrode plate for secondary battery

Abstract

The invention relates to an anti-skew drying chamber device for an electrode plate for a secondary battery. Namely, an electrode sheet having a coating portion that is a region coated with an active material and a non-coating portion that is a region not coated with the active material is passed through and heated, thereby drying the active material by heat, comprising: a drying case that has an inlet portion and an outlet portion, passes through the electrode sheet, and provides a drying space; a plurality of conveying rollers which are arranged inside the drying housing and convey the electrode slices entering from the inlet part and send the electrode slices out from the outlet part; a heating unit that heats the electrode sheet passing through the drying case to dry the active material; and a plurality of skew prevention rollers that are provided between the conveyance rollers and that apply a traction force to the non-coated portion of the electrode sheet to prevent skew of the electrode sheet. The electrode slice skew prevention type drying chamber device for the secondary battery can prevent skew of the electrode slice passing through the drying shell, thereby realizing uniform drying of the active material.

Description

Technical Field

[0001] This invention relates to an active material drying chamber used in the manufacturing process of secondary batteries, and more specifically, to an anti-slant drying chamber device for electrode sheets in secondary batteries, which prevents the electrode sheets passing through the drying chamber from slanting, thereby preventing uneven drying and providing good drying efficiency. Background Technology

[0002] A secondary battery is a rechargeable battery that has a structure that allows for repeated charging and discharging by the movement of ions in the electrolyte between the anode and cathode, which are insulated by a separator.

[0003] The electrodes in a secondary battery, namely the anode and cathode, have a laminated structure consisting of a current collector and an electrode material layer. The current collector is a sheet or foil made of aluminum or copper, while the electrode material layer is a laminated body consisting of an active material in slurry form coated and cured onto the current collector. The electrode material layer is formed by drying and curing the active material.

[0004] Figure 1 This is a partial perspective view showing the electrode plates used in a typical secondary battery.

[0005] Referring to the accompanying drawings, an electrode material layer 13 is laminated on a current collector substrate 11 having a constant width. The electrode material layer 13 is formed by heating and drying a coated active substance. On the current collector substrate 11, the area coated with the electrode material layer 13 is the coated portion 10A, and the area not coated with the electrode material layer 13 is the uncoated portion 10B.

[0006] On the other hand, electrodes for secondary batteries are manufactured by coating active materials onto current collector substrates that are continuously supplied in roll-to-roll manner, followed by processes such as magnetic alignment, drying, curing, cutting, and notching. In these multi-step manufacturing processes, a drying chamber is used as equipment for drying the active materials.

[0007] Magnetic alignment is a process performed before drying the active material in a secondary battery. It involves aligning the magnetic particles within the active material in a specific direction. The purpose of magnetic alignment is to improve the conductivity and mechanical strength of the electrodes. However, magnetic alignment also has disadvantages, namely, the possibility of the electrode sheets becoming misaligned during transport. This will be addressed by referring to... Figure 2 This will be discussed later.

[0008] Figure 2 This is a schematic plan view used to illustrate the problems existing in the conventional electrode drying chamber device 20.

[0009] As shown in the figure, the conventional chamber device 20 includes a drying shell 21, a roller frame 22, a conveying roller 23, and a heating dryer (not shown).

[0010] The drying housing 21 provides a drying space for the electrode sheet 10 to pass through and be dried. Furthermore, a roller frame 22 horizontally supports multiple conveyor rollers 23 inside the drying housing 21. The conveyor rollers 23 convey the electrode sheet 10 in a state rotatably supported by the roller frame 22. The electrode sheet 10, after being oriented by individual orientation devices 15, is conveyed in the direction of arrow a, supported by the conveyor rollers 23. A heating dryer is located above the conveyor rollers 23 and heats and dries the active material of the conveyed electrode sheet.

[0011] However, a problem with the aforementioned conventional chamber device 20 is that the electrode sheet 10 moves at an angle during its movement in the direction of arrow a. In other words, the electrode sheet 10 does not move straight along the conveyor roller, but is gradually pushed to one side in the width direction during the conveying process. This is caused by the magnetic force of the magnetically oriented active material. In other words, this is due to the attraction of the electrode sheet to the ferrous material on the inner wall of the drying housing 21. The angled movement of the electrode sheet 10 hinders the normal drying of the active material, thus leading to poor secondary battery performance.

[0012] There is a need for an anti-skewing method for effectively drying an oriented active substance coated on a current collector substrate.

[0013] As background technology related to the oblique movement of electrode sheets, Korean Patent Publication No. 10-2330719 (Electrode sheet processing apparatus for secondary batteries using laser and vision) was previously published.

[0014] The disclosed processing apparatus includes: a conveying unit that continuously conveys an electrode sheet while unwinding it; a vision unit equipped with at least one camera for capturing images of at least one edge portion of the electrode sheet's width-direction edges to capture the oblique state of the conveyed electrode sheet in real time and provide oblique information; a measuring unit that measures the conveying distance of the electrode sheet and provides conveying distance information in real time; a control unit that obtains the position of a pre-set processing area of ​​the electrode sheet using the conveying distance information provided in real time by the measuring unit, and obtains the oblique state of the electrode sheet using the oblique information provided in real time by the vision unit, and provides processing information for a processing area generated or corrected corresponding to the oblique state of the electrode sheet, the processing information including laser irradiation time point, laser irradiation position, and laser irradiation angle; and at least one laser cutter or blade cutter that receives the processing information provided from the control unit and performs laser cutting on the processing area of ​​the electrode sheet based on the processing information. Summary of the Invention

[0015] Technical issues

[0016] The present invention is proposed to solve the above-mentioned problems. Its purpose is to provide a drying chamber device for electrode sheets of secondary batteries that prevents the electrode sheets passing through the drying shell from becoming oblique, thereby achieving uniform drying of active materials.

[0017] Technical solution

[0018] As a technical solution for achieving the above-mentioned objectives, the anti-skewing drying chamber device for electrode sheets of the secondary battery of the present invention dries the active material by passing through and heating an electrode sheet having an area coated with active material (i.e., a coated portion) and an area uncoated with active material (i.e., a non-coated portion). The anti-skewing drying chamber device for electrode sheets of the secondary battery includes: a drying shell having an inlet and an outlet for passing through the electrode sheet and providing a drying space; a plurality of conveying rollers disposed inside the drying shell for conveying the electrode sheet entering from the inlet and exiting from the outlet; a heating unit for heating the electrode sheet passing through the drying shell to dry the active material; and a plurality of anti-skewing rollers disposed between the conveying rollers for applying traction force to the non-coated portion of the electrode sheet to prevent the electrode sheet from skewing.

[0019] Furthermore, the anti-skewing roller is a convex roller with a shape in which the diameter of the part in contact with the non-coated part is relatively larger than the diameter of the other part.

[0020] In addition, the conveying roller includes a pad roller having a constant diameter and having fine irregularities formed on its outer circumferential surface.

[0021] In addition, the upper part of the convex roller is provided with a pressing part, which presses the electrode sheet toward the convex roller side to prevent the convex roller from slipping relative to the non-coated part.

[0022] Meanwhile, the anti-skewing rollers are relatively more numerous in the rear half of the electrode sheet conveying path inside the drying housing, compared to the front half.

[0023] In addition, the anti-skewing roller has: a supporting surface that supports the coated portion of the electrode sheet; and an anti-slip surface that is integral with the supporting surface, supports and supports the uncoated portion, and has a surface roughness higher than that of the supporting surface.

[0024] In addition, the anti-skewing roller includes: a support surface that contacts the coated portion of the electrode sheet; and a friction ring that supports and abuts the uncoated portion and has a larger diameter than the support surface.

[0025] The effects of the invention

[0026] The electrode sheet anti-slant drying chamber device for secondary batteries of the present invention, configured as described above, can prevent the electrode sheets passing through the drying shell from slanting, thereby achieving uniform drying of the active material. Attached Figure Description

[0027] Figure 1 This is a partial perspective view showing the electrode plates used in a typical secondary battery.

[0028] Figure 2 This is a plan view used to illustrate the problems existing in conventional electrode drying chamber devices.

[0029] Figure 3 This is a side view showing the overall structure of an electrode sheet anti-slant drying chamber device according to an embodiment of the present invention.

[0030] Figure 4 It is Figure 3 The diagram showing the padding roller is presented separately.

[0031] Figure 5 It is used for explanation Figure 3 A diagram illustrating the structure and working principle of the anti-skewing roller.

[0032] Figure 6 and Figure 7 It is shown in Figure 5 The diagram shows the state in which the anti-skewing roller is equipped with a pressing roller on its upper part.

[0033] Figures 8 to 10 This is a diagram illustrating a modified example of an anti-skewing roller that can be used in a drying chamber apparatus according to an embodiment of the present invention. Detailed Implementation

[0034] An embodiment of the present invention will now be described in more detail with reference to the accompanying drawings.

[0035] Figure 3 This is a side view showing the overall configuration of an electrode sheet anti-slant type drying chamber device 30 according to an embodiment of the present invention.

[0036] As shown in the figure, the drying chamber device 30 of this embodiment includes a drying shell 31, a heating part, a roller frame 35, a conveying roller 41, anti-skewing rollers 43, 45, 47, 49, and a pressing roller 42.

[0037] The drying housing 31 is a structure through which the electrode sheet 10 passes, and it provides an inlet 31a and an outlet 31b. The electrode sheet 10, which has a constant width and is continuous in the length direction, enters the drying space 31d of the drying housing 31 through the inlet 31a and exits through the outlet 31b. The dimensions and configuration of the drying housing 31 itself are the same as those of a general drying chamber.

[0038] Reference numeral 17 in the figure refers to a guide roller. The guide roller 17 supports and holds the electrode sheet 10 that enters and exits the drying housing 31.

[0039] like Figure 1As shown, the electrode sheet 10 entering the drying housing 31 through the inlet 31a is composed of a current collector substrate 11 with a constant width and an active material layer coated on the current collector substrate. The active material layer is heated and dried during the process of passing through the drying housing 31 to become the electrode material layer 13. Furthermore, the area coated with the active material layer is the coated portion 10A, and the area without the active material layer is the uncoated portion 10B.

[0040] The heating unit is a heat dryer 33 located on the upper inner side of the drying housing 31, which heats and dries the active material of the electrode plates passing through the drying space 31d. The heat dryer 33 outputs radiant heat at 100°C to 170°C. Various types of heat dryers 33 can be used, such as halogen lamps.

[0041] The roller frame 35 is a structure horizontally arranged at the lower part of the heating dryer 33, which can rotatably support the conveyor roller 41, anti-skewing rollers 43, 45, 47, 49 and pressing roller 42.

[0042] The two ends of the conveying roller 41 are rotatably supported on the roller frame, and multiple conveying rollers are arranged in parallel to provide a conveying path for the electrode sheet 10. The electrode sheet 10 passes through the drying space 31d in a state supported and supported by the conveying roller 41 and detaches from the outlet 31b.

[0043] In particular, as shown in Figure 4, a portion or all of the conveying roller 41 may have fine irregularities 41a formed on its outer peripheral surface. The fine irregularities 41a are used to prevent the current collector substrate 11 constituting the electrode sheet from slipping. The maximum height of the protrusions constituting the fine irregularities is less than 1 / 10 of the thickness of the current collector substrate 11.

[0044] Anti-skewing rollers 43, 45, 47, and 49 are positioned between the conveyor rollers 41 to apply traction force to the non-coated portion 10B of the electrode sheet 10, preventing the electrode sheet from skewing. Unlike the conveyor rollers 41, which apply traction force to both the non-coated portion 10A and the coated portion 10B, the anti-skewing rollers concentrate the traction force only on the non-coated portion 10B. The total traction force applied by the conveyor rollers or the anti-skewing rollers is equal.

[0045] For example, assuming a traction force of 100, the force of 100 is uniformly distributed along the width direction when conveying the electrode sheet 10 on the conveying roller 41; while when conveying the electrode sheet 10 on the anti-skewing roller, the force of 100 is only transmitted to the non-coated portion 10B. In other words, only the non-coated portion 10B located in the center of the electrode sheet 10 is pulled. As long as this function can be achieved, the configuration of the anti-skewing roller can be arbitrarily changed.

[0046] When only the moment when the electrode sheet 10 passes over the anti-skewing roller is considered, the part of the electrode sheet 10 except for the non-coated part 10B is in a suspended state. Only the non-coated part 10B is subjected to the conveying force, i.e. the traction force. Therefore, the electrode sheet 10 is conveyed only in the direction guided by the anti-skewing roller.

[0047] Although anti-skewing rollers 43, 45, 47, and 49 could be used to replace all conveyor rollers 41, the ends of the electrode sheet 10 in the width direction might sag due to gravity. Therefore, approximately one anti-skewing roller can be used for every N conveyor rollers. N is preferably 10 to 15.

[0048] Furthermore, compared to the first half of the electrode sheet conveying path inside the drying housing 31, the anti-skewing rollers are relatively more numerous in the second half. The first half is the range from the inlet 31a to the outlet 31b. The second half is the range from the end of the first half to the outlet 31b.

[0049] The anti-skewing rollers can be configured in 3% to 10% of the front half and 90% to 97% of the rear half. Furthermore, the anti-skewing rollers configured in the rear half are more densely arranged closer to the outlet 31b.

[0050] The pressing roller 42 is horizontally positioned above the anti-skewing rollers 43, 45, 47, and 49. It presses the electrode sheet 10, which is passing over the anti-skewing roller, downwards to prevent the anti-skewing roller from slipping relative to the non-coated area. The shape of the pressing roller can be varied, as will be described later. The pressing roller 42 can also be further positioned above the conveying roller 41.

[0051] Figure 5 It is shown Figure 3 The diagram shows an example of an anti-skewing roller.

[0052] Figure 5 The anti-skewing roller 43 of the type shown is a convex roller with a diameter at the center of its length direction, i.e., the diameter of the part that contacts the non-coated part 10B, being relatively larger than the diameter of other parts.

[0053] The anti-skewing roller 43 makes point contact with the uncoated portion 10B. The point contact portion is the traction portion 43a, which provides traction force to the electrode sheet 10. Although the active material of the electrode sheet 10 is oriented, the central portion of the electrode sheet, i.e., the uncoated portion 10B, is pulled by the traction portion 43a and will not skew.

[0054] In the figures illustrating this embodiment, the diameter of the traction portion 43a of the anti-skewing roller 43 is shown to be larger than the diameters of other portions for easy visual distinction. However, in actual equipment, the diameter of the traction portion 43a is so large as to be imperceptible to the naked eye. The difference between the diameter of the traction portion 43a of the anti-skewing roller 43 and the diameter of the smallest diameter portion is less than or equal to the thickness of the electrode sheet 10.

[0055] Figure 6 and Figure 7 It is shown in Figure 5 The diagram shows the state in which the anti-slant roller is equipped with the pressing roller 42 on its upper part.

[0056] Figure 6 The pressing roller 42 shown is a flat roller with a constant outer diameter that presses the electrode sheet 10 downwards. As the electrode sheet 10 is pressed downwards, the bottom surface of the non-coated portion 10B comes into closer contact with the traction portion 43a of the anti-skewing roller 43. When the pressing roller 42 is used, the number of anti-skewing rollers 43 can be reduced.

[0057] also, Figure 7 The pressing roller 42 has the same shape as the anti-skewing roller 43 on the lower side. That is, the pressing roller 42 itself is a convex roller. The maximum diameter portion of the pressing roller 42 is located above the maximum diameter portion of the anti-skewing roller 43 in the vertical direction. The pressing roller 42 applies downward pressure to the central portion of the non-coated portion 10B of the electrode sheet 10, so that it is strongly pressed against the traction portion 43a of the anti-skewing roller 43.

[0058] Figures 8 to 10 This is a diagram illustrating a modified example of an anti-skewing roller that can be used in a drying chamber apparatus according to an embodiment of the present invention.

[0059] Figure 8 The anti-slip roller 45 shown has a support surface 45a and an anti-slip surface 45b.

[0060] The supporting surface 45a supports the coated portion 10A of the electrode sheet 10 and has the same diameter as the conveying roller 41. The anti-slip surface 45b is located in the center of the anti-slip roller 45 and supports the uncoated portion of the electrode sheet 10. The anti-slip surface 45b has finely textured surfaces with a higher surface roughness than the supporting surface 45a. The anti-slip surface 45b contacts the uncoated portion 10B of the electrode sheet 10, acting as a traction part to pull the uncoated portion.

[0061] Figure 9 The anti-skewing roller 47 consists of a support surface 47a with a constant diameter and a protrusion 47b formed at the center of the anti-skewing roller 47 in the longitudinal direction. The protrusion 47b is a portion with a relatively larger diameter than the support surface 47a. Figure 9In the illustration, the protrusion 47b is shown to protrude to a degree that is not visually distinguishable from the slanted roller 47, but this is shown for convenience and is not actually visible to the naked eye. The protrusion height of the protrusion 47b relative to the support surface 47a is less than 1 / 5 of the current collector substrate 11.

[0062] on the other hand, Figure 10 The anti-skewing roller 49 shown consists of a support surface 49a with a constant diameter and two friction rings 49c located at the center of the anti-skewing roller 49. The support surface 49a supports and supports the bottom surface of the coating section 10A. Furthermore, the friction rings 49c are annular components made of rubber and are detachably inserted into the central groove 49b. The outer diameter of the friction rings 49c is relatively larger than the outer diameter of the support surface 49a.

[0063] To allow the friction ring 49c to be mounted on the anti-skewing roller 49, a central groove 49b is formed on the outer circumferential surface of the central portion of the anti-skewing roller 49. The central groove 49b is a groove with a constant width and depth. The friction ring 49c is inserted into the central groove 49b and pressed against the bottom surface of the non-coated portion 10B. When the anti-skewing roller 49 rotates, the friction ring 49c acts as a traction part that provides traction force to the non-coated portion 10B.

[0064] Of course, in Figures 8 to 10 The upper part of the anti-slant roller of the type shown can also be fitted with the pressing roller 42 described above.

[0065] In summary, the drying chamber apparatus 30 of this embodiment, configured as described above, avoids skewing caused by the magnetic force of the electrode sheets by applying anti-skewing rollers between the conveying rollers of the conveying electrode sheets 10.

[0066] The present invention has been described in detail above through specific embodiments, but the present invention is not limited to the above embodiments. Within the scope of the technical concept of the present invention, those skilled in the art can make various modifications.

[0067] Industrial applicability

[0068] Because it can prevent the electrode plates from sliding obliquely through the drying shell, thus achieving uniform drying of the active material, it has industrial applicability.

Claims

1. A drying chamber device for electrode sheets of secondary batteries with anti-slant type, which dries the active material by passing an electrode sheet having an area coated with active material (coated portion) and an area uncoated with active material (non-coated portion) through and heating it, wherein the active material is dried by heat. The drying chamber device for electrode sheets of secondary batteries with anti-slant type is characterized by comprising: The drying housing has an inlet and an outlet for the electrode sheets to pass through and for providing a drying space. Multiple conveyor rollers, arranged inside the drying housing, convey the electrode sheets that enter from the inlet and exit from the outlet. The heating section heats the electrode plates passing through the drying shell to dry the active material; and Multiple anti-skewing rollers are arranged between the conveying rollers to apply traction force to the non-coated portion of the electrode sheet to prevent the electrode sheet from skewing.

2. The anti-slant drying chamber device for electrode sheets of secondary batteries according to claim 1, characterized in that, The anti-skewing roller is a convex roller with a shape in which the diameter of the part in contact with the non-coated part is relatively larger than the diameter of the other part.

3. The anti-slant drying chamber device for electrode sheets of secondary batteries according to claim 2, characterized in that, The conveying roller includes a padding roller having a constant diameter and having fine irregularities formed on its outer circumferential surface.

4. The anti-slant drying chamber device for electrode sheets of secondary batteries according to claim 2, characterized in that, The upper part of the convex roller is also provided with a pressing part, which presses the electrode sheet toward the convex roller side to prevent the convex roller from slipping relative to the non-coated part.

5. The anti-slant drying chamber device for electrode sheets of secondary batteries according to claim 1, characterized in that, The anti-skewing rollers are relatively more numerous in the rear half of the electrode sheet conveying path inside the drying housing, compared to the front half.

6. The anti-slant drying chamber device for electrode sheets of secondary batteries according to claim 1, characterized in that, The anti-skew roller has: Supports the face, including the coating portion of the supporting electrode sheet; as well as The anti-slip surface is integral with the supporting surface, supports and supports the uncoated part, and has a higher surface roughness than the supporting surface.

7. The anti-slant drying chamber device for electrode sheets of secondary batteries according to claim 1, characterized in that, The anti-skew roller includes: Supporting the face, which contacts the coated portion of the electrode pad; and A friction ring, which supports and holds the uncoated portion, has a larger diameter than the supporting face.

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