Battery electrode coating device

Abstract

The battery electrode coating device consists of a coating mold, a wedge mounted on the mold, and a bolt-type fixing device that secures the wedge to the mold so that the tightening element passes through the wedge and tightens into the mold. A portion of the tightening element is positioned inside the through-hole of the wedge and comprises at least two steps of different diameters.

Description

Battery electrode coating device

[0001] The present invention relates to an electrode coating apparatus, and more specifically, to a battery electrode coating apparatus for coating an intermediate material onto a thin film in a battery electrode process.

[0002] With the increasing technological development and demand for mobile devices, the demand for rechargeable batteries as an energy source is rapidly rising. Among rechargeable batteries, lithium-ion batteries, which exhibit high energy density and operating potential, long cycle life, and low self-discharge rate, have been commercialized and are widely used.

[0003] Furthermore, with the recent increase in interest in environmental issues, extensive research is being conducted on electric vehicles (EVs) and hybrid electric vehicles (HEVs) that can replace fossil fuel-using vehicles, such as gasoline and diesel cars, which are one of the major causes of air pollution. Lithium-ion batteries, characterized by high energy density, high discharge voltage, and output stability, are primarily being researched and used as the power source for these EVs and HEVs.

[0004] These lithium secondary batteries are generally manufactured by stacking or winding positive and negative electrodes with a separator in between, and embedding them in a battery case along with an electrolyte. Electrodes such as the positive and negative electrodes are manufactured by applying, drying, and rolling an active material slurry onto a current collector, and the application of the active material slurry is generally performed by a coating device that discharges the active material slurry.

[0005] Generally, an electrode coating device includes an upper coating die, a lower coating die, and a shim assembly interposed between them. The shim assembly includes spacer shims and a body shim that discharge an insulating liquid, and the spacer shims are secured to the lower coating die via fixing bolts.

[0006] In a coating device, spacer shims are individually assembled to the lower coating die using fixing bolts. When fixing spacer shims to the lower coating die using fixing bolts in this manner, managing assembly tolerances is important. In particular, managing the shim offset, which refers to the distance between the spacer shim and the end of the lower coating die, is essential.

[0007] Generally, the fixing bolt (30) that assembles the spacer shims (10) to the lower coating die (20) is composed of a head portion (31) and a fastening portion (32) as shown in FIGS. 12 and 13, and the fastening portion (32) is formed as a single-stage structure with the same diameter. In this way, according to the conventional fastening structure in which the fastening portion (32) of the fixing bolt (30) is formed as a single-stage structure, it is not easy to manage the assembly tolerance between the spacer shims (10) and the lower coating die (20). In particular, since the inner diameter of the shim hole (11) formed in the spacer shim (10) is formed relatively large compared to the diameter of the fastening portion (32), the clearance of the spacer shim (10) is bound to be large. That is, the assembly tolerance between the spacer shims (10) and the lower coating die (20) is bound to be large.

[0008] As such, if the assembly tolerance between the spacer shims (10) and the lower coating die (20) becomes large, the coating quality of the electrode is bound to deteriorate.

[0009] The present invention was devised to solve the problems of the prior art as described above, and aims to provide a battery electrode coating device that allows for smooth management of the shim offset between the spacer shim and the lower coating die end.

[0010] A battery electrode coating device according to the present invention for achieving the above-mentioned purpose comprises a coating die, a spacer core mounted on the coating die, and a bolt-type fixing member that fixes the spacer core to the coating die in a manner in which a fastening part penetrates the spacer core and is then fastened to the coating die, wherein the portion of the fastening part located within the through hole of the spacer core is composed of at least two stages having different diameters.

[0011] A fastening groove is formed in the coating die for the fastening part to be screw-fastened.

[0012] At least one of the parts located within the through hole of the fastening portion may have an outer surface that comes into surface contact with the inner surface of the through hole.

[0013] The fastening portion may include a threaded portion, in which a portion is located within a through hole and the remainder is screw-fastened to a coating die and threads are formed on all or part thereof, and a tolerance improvement portion formed between the head portion and the threaded portion, having a larger diameter than the threaded portion and located within the through hole.

[0014] The through hole can be formed as a single step with a constant inner diameter.

[0015] The through hole may include a threaded through hole through which a threaded portion passes, and a tolerance improvement through hole connected to the threaded through hole, having an inner diameter larger than that of the threaded through hole, through which a tolerance improvement portion passes.

[0016] The tolerance improvement section is formed as a single step with a constant diameter, and the tolerance improvement section through hole can be formed as a single step with a constant inner diameter.

[0017] The tolerance improvement section is formed in at least two stages with different diameters, and the tolerance improvement section through hole is formed in at least two stages with different inner diameters, and a step difference may be formed between each stage.

[0018] The tolerance improvement section may include a first tolerance improvement section connected to a screw section and having a larger diameter than the screw section, and a second tolerance improvement section formed between the first tolerance improvement section and the head section and having a larger diameter than the first tolerance improvement section.

[0019] The tolerance improvement part through hole may include a first tolerance improvement part through hole that is connected to the screw part through hole and has an inner diameter larger than the screw part through hole and through which the first tolerance improvement part passes, and a second tolerance improvement part through hole that is connected to the first tolerance improvement part through hole and has an inner diameter larger than the first tolerance improvement part through hole and through which the second tolerance improvement part passes.

[0020] The spacer shim can be secured to the coating die using at least two fixing members.

[0021] The spacer shim is secured to the coating die using three fixing members, and the three fixing members can be placed on the vertices of a virtual isosceles triangle.

[0022] According to the battery electrode coating device of the present invention, by configuring the portion located within the through hole of the spacer core, which is fastened to the coating die after penetrating the through hole of the spacer core, into at least two stages with different diameters, the assembly tolerance of the spacer core and the coating die can be reduced when using the conventional assembly configuration of the spacer core and the coating die.

[0023] That is, by configuring the fastening part with a threaded portion where screw threads are formed and a tolerance improvement portion that has a larger diameter than the threaded portion and is located within the through hole, the gap between the fastening part and the inner surface of the through hole is reduced compared to the conventional method, thereby allowing the assembly tolerance of the spacer shim and the coating die to be reduced.

[0024] In addition, at least one outer surface of the portion located within the through hole of the fastening portion is formed to come into surface contact with the inner surface of the through hole, thereby further reducing the assembly tolerance between the spacer shim and the coating die.

[0025] Through the structures described above, the assembly tolerance between the spacer shim and the coating die can be minimized, thereby maintaining good coating quality.

[0026] FIG. 1 is an exploded perspective view of a battery electrode coating device according to one embodiment of the present invention.

[0027] Figure 2 is a perspective view of a spacer core.

[0028] FIG. 3 is a perspective view showing the spacer shim fixed to the lower coating die.

[0029] FIG. 4 is a cross-sectional view showing an example of a spacer shim being fixed to a lower coating die using a fixing member.

[0030] FIG. 5 is a side view of the fixing member shown in FIG. 4.

[0031] Figure 6 is a cross-sectional view showing the fixed member removed from Figure 4.

[0032] FIG. 7 is a cross-sectional view showing another example of a spacer shim being fixed to a lower coating die with a fixing member.

[0033] FIG. 8 is a cross-sectional view showing the fixed member removed from FIG. 7.

[0034] FIG. 9 is a cross-sectional view showing another example of a spacer shim being fixed to a lower coating die with a fixing member.

[0035] FIG. 10 is a side view of the fixing member shown in FIG. 9.

[0036] FIG. 11 is a cross-sectional view showing the fixed member removed from FIG. 9.

[0037] FIG. 12 is a cross-sectional view showing the assembly relationship between a spacer shim and a lower coating die according to the prior art.

[0038] FIG. 13 is a side view of the fixing member shown in FIG. 12.

[0039] Hereinafter, a battery electrode coating device according to a preferred embodiment of the present invention will be described in detail with reference to the attached drawings.

[0040]

[0041] FIG. 1 is an exploded perspective view of a battery electrode coating device according to one embodiment of the present invention, FIG. 2 is a perspective view of a spacer core, and FIG. 3 is a perspective view showing the spacer core fixed to a lower coating die.

[0042] A battery electrode coating device according to one embodiment of the present invention includes an upper coating die (100), a lower coating die (200), and a shim assembly (300) provided between them. The shim assembly (300) includes a body shim (310) and a spacer shim (320) that discharges an insulating liquid. The spacer shims (320) can be fixed to the lower coating die (200) using a bolt-type fixing member to be described later.

[0043] The battery electrode coating device is configured so that the active material slurry stored in the lower coating die (200) is discharged through the spacer shims (320). The insulating liquid is discharged from the spacer shims (320).

[0044] An insulating liquid injection path (110) is formed in the upper coating die (100) through which insulating liquid is injected from the outside. The insulating liquid injection path (110) is formed from the top to the bottom. Insulating liquid is supplied to the spacer shim (320) through the insulating liquid injection path (110) of the upper coating die (100).

[0045] In the lower coating die (200), a slurry input path (not shown) through which an active material slurry is introduced from the outside and a slurry storage space (210) in which the active material slurry is stored are formed. The active material slurry stored in the slurry storage space (210) of the lower coating die (200) is discharged between the spacer shims (320).

[0046] A plurality of spacer shims (320) are fixed at equal intervals on the upper surface of the lower coating die (200), particularly adjacent to the end of the lower coating die (200). The spacer shims (320) are individually assembled to the lower coating die (200) using a fixing member. When fixing the spacer shims (320) to the lower coating die (200) using a fixing member in this manner, assembly tolerance management is important. In particular, to maintain good coating quality, it is essential to manage the shim offset, which refers to the distance between the spacer shims (320) and the end of the lower coating die (200).

[0047] An insulating fluid channel (321) is formed in the spacer shim (320) through which insulating fluid introduced from the upper coating die (100) flows, and insulating fluid is discharged during the coating process through the end of the insulating fluid channel (321). The insulating fluid channel (321) may have two branch channels extending parallel to each other toward one end of the spacer shim (320).

[0048] Three through holes (322) are formed in each spacer shim (320), and each spacer shim (320) is fixed to the lower coating die (200) using three fixing members. The fixing stability of the spacer shim (320) can be improved by arranging the three through holes (322) in a triangular shape. In one embodiment, one of the three through holes (322) is drilled adjacent to one end of the spacer shim (320), and the remaining two through holes are drilled adjacent to the other end of the spacer shim. The three through holes (322) can be positioned on the vertices of a virtual isosceles triangle. The through hole (322) drilled on the one end of the spacer shim (320) can be positioned between the two branch paths of the insulating fluid path (321).

[0049]

[0050] FIG. 4 is a cross-sectional view showing an example of a spacer shim fixed to a lower coating die with a fixing member, FIG. 5 is a side view of the fixing member shown in FIG. 4, and FIG. 6 is a cross-sectional view showing the fixing member removed from FIG. 4.

[0051] The fixing member (400) fixes the spacer shim (320) to the lower coating die (200), is configured as a bolt type, and includes a head portion (410) and a fastening portion (420). The fastening portion (420) includes two parts with different diameters.

[0052] The head portion (410) of the fixing member (400) is caught on the upper surface of the spacer core (320), and the fastening portion (420) is formed to penetrate the spacer core (320) and then be screw-fastened to the lower coating die (200), thereby connecting the spacer core (320) and the lower coating die (200). That is, the lower surface of the head portion (410) is in close contact with the upper surface of the spacer core (320), and the fastening portion (420) penetrates the spacer core (320) and is screw-fastened to the coating die (200).

[0053] A through hole (322) through which a fastening part (420) passes is formed in the spacer shim (320), and a fastening groove (220) into which the fastening part (420) is screw-fastened is formed in the lower coating die (200). The fastening part (420) includes at least two parts with different diameters. In the embodiment illustrated in FIGS. 4 to 6, the fastening part (420) includes two parts with different diameters. The through hole (322) and the fastening groove (220) are formed as a single step with a constant inner diameter.

[0054] The fastening portion (420) may include a screw portion (421) and a tolerance improvement portion (422). The screw portion (421) of the fastening portion (420) is screw-fastened to the fastening groove (220) while passing through the through hole (322). Screw threads may be formed on all or part of the screw portion (421). The tolerance improvement portion (422) is formed between the head portion (410) and the screw portion (421), has a larger diameter than the screw portion (421), and can be inserted into the through hole (322). A step is formed between the screw portion (421) and the tolerance improvement portion (422).

[0055] The tolerance improvement part (422) can be inserted while making surface contact with the through hole (322). That is, the inner diameter of the through hole (322) is formed to correspond to the diameter of the tolerance improvement part (422), so that the tolerance improvement part (422) can be inserted while its outer surface makes surface contact with the inner surface of the through hole (322).

[0056]

[0057] FIG. 7 is a cross-sectional view showing another example of a spacer shim fixed to a lower coating die with a fixing member, and FIG. 8 is a cross-sectional view showing FIG. 7 with the fixing member removed.

[0058] In this embodiment, the through hole (322A) includes a threaded portion through hole (323) through which a threaded portion (421) passes, and a tolerance improvement portion through hole (324) connected to the threaded portion through hole (323), having an inner diameter larger than that of the threaded portion through hole (323), into which a tolerance improvement portion (422) is inserted. A step is formed between the threaded portion through hole (323) and the tolerance improvement portion through hole (324).

[0059] Meanwhile, the portion of the screw portion (421) that does not have screw threads can pass through while its outer surface contacts the inner surface of the screw portion through hole (323), and the tolerance improvement portion (422) can be inserted while its outer surface contacts the inner surface of the tolerance improvement portion through hole (324).

[0060]

[0061] FIG. 9 is a cross-sectional view showing another example of a spacer shim being fixed to a lower coating die with a fixing member, FIG. 10 is a side view of the fixing member shown in FIG. 9, and FIG. 11 is a cross-sectional view showing the fixing member removed from FIG. 9.

[0062] In this embodiment, the fixing member (400A) includes a head portion (430) and a fastening portion (440), wherein the fastening portion (440) may be formed as a three-stage structure with different diameters.

[0063] The fastening part (440) may include a screw part (441) and a tolerance improvement part (442) of a two-stage structure.

[0064] The tolerance improvement section (442) includes a first tolerance improvement section (443) connected to the screw section (441) and having a larger diameter than the screw section (441), and a second tolerance improvement section (444) formed between the first tolerance improvement section (443) and the head section (430) and having a larger diameter than the first tolerance improvement section (443). Steps are formed between the screw section (441) and the first tolerance improvement section (443), and between the first tolerance improvement section (443) and the second tolerance improvement section (444), respectively.

[0065] The through hole (322B) formed in the spacer shim (320) includes a threaded through hole (325) and a tolerance improvement through hole (326).

[0066] The tolerance improvement part through hole (326) includes a first tolerance improvement part through hole (327) which is connected to the threaded part through hole (325), has an inner diameter larger than the threaded part through hole (325), and through which the first tolerance improvement part (443) is inserted; and a second tolerance improvement part through hole (328) which is connected to the first tolerance improvement part through hole (327), has an inner diameter larger than the first tolerance improvement part through hole (327), and through which the second tolerance improvement part (444) is inserted. Steps are formed between the threaded part through hole (325) and the first tolerance improvement part through hole (327), and between the first tolerance improvement part through hole (327) and the second tolerance improvement part through hole (328), respectively.

[0067] Meanwhile, the portion of the screw portion (441) that does not have screw threads can pass through while its outer surface contacts the inner surface of the screw portion through hole (325), the first tolerance improvement portion (443) can be inserted while its outer surface contacts the inner surface of the first tolerance improvement portion through hole (327), and the second tolerance improvement portion (444) can be inserted while its outer surface contacts the inner surface of the second tolerance improvement portion through hole (328).

[0068]

[0069] According to the battery electrode coating device of the present invention, the fastening portion (420)(440) of the fixing member (400)(400A) formed as a bolt type may be configured to have multiple stages with different diameters, and the outer surface of at least one of the multiple stages may be configured to be inserted in a surface contact manner into the inner surface of the through hole (322)(322A)(322B) of the spacer core (320).

[0070] In particular, the fastening portion (420)(440) includes a screw portion (421)(441) that is screw-fastened to the lower coating die (200) while penetrating the spacer shim (320), and a tolerance improvement portion (422)(442) formed between the screw portion (421)(441) and the head portion (410)(430), wherein the tolerance improvement portion (422)(442) is composed of at least one end having a different diameter, and the entire tolerance improvement portion (422)(442) or at least one end may be inserted in a surface contact manner into the inner circumference of the through hole (322)(322A)(322B).

[0071] Through this assembly structure, the assembly tolerance of the spacer shim (320) is reduced to within a few μm, so the shim offset between the spacer shim (320) and the end of the lower coating die (200) can be managed smoothly and the coating quality can be maintained well.

[0072] In particular, in the embodiment illustrated in FIGS. 4 to 6, the spacer shim (320) and lower coating die (200) can be used as they are with the conventional spacer shim (10) and lower coating die (200), and only the fixing member (400) is changed, thereby minimizing the assembly tolerance of the spacer shim (320) and lower coating die (200). For reference, the through hole (322) formed in the spacer shim (320) illustrated in FIGS. 4 to 6 can be formed with the same size as the shim hole (11) formed in the conventional spacer shim (10).

[0073] In the embodiment illustrated in FIGS. 4 to 6, the fastening portion (420) is formed as a two-stage structure of a screw portion (421) and a tolerance improvement portion (422) having different diameters. By forming the screw portion (421) with the same diameter as the conventional fastening portion (32) and forming the diameter of the tolerance improvement portion (422) larger than the diameter of the screw portion (421), the gap between the fastening portion (420) and the inner surface of the through hole (322) is reduced compared to the conventional method, thereby reducing the assembly tolerance of the spacer shim and the coating die. In particular, the assembly tolerance can be minimized by inserting the tolerance improvement portion (422) into the inner surface of the through hole (322) in a surface contact manner.

[0074]

[0075] Although a battery electrode coating device according to embodiments of the present invention has been described in detail with reference to the attached drawings as above, the present invention is not limited to the embodiments described above and can be implemented in various modified ways within the scope of the claims.

[0076] [Explanation of the symbol]

[0077] 100: Upper coating die 110: Insulating liquid injection path

[0078] 200: Bottom coating die 210: Slurry storage space

[0079] 220 : Fastening groove 300 : Seam assembly

[0080] 310: Body shim 320: Spacer shim

[0081] 321: Insulating fluid path 322, 322A, 322B: Through holes

[0082] 323, 325: Through-holes for threaded sections 324, 326: Through-holes for tolerance improvement sections

[0083] 327: 1st tolerance improvement part through hole 328: 2nd tolerance improvement part through hole

[0084] 400, 400A: Fixing member 410, 430: Head part

[0085] 420, 440: Fastening part 421, 441: Threaded part

[0086] 422, 442: Tolerance Improvement Department 443: 1st Tolerance Improvement Department

[0087] 444 : 2nd Tolerance Improvement Department

Claims

1. Coating die; A spacer shim mounted on the coating die above; and A bolt-type fixing member that fixes the spacer shim to the coating die in a manner in which the fastening portion penetrates the spacer shim and is fastened to the coating die; comprising A battery electrode coating device in which the portion of the above-mentioned fastening part located within the through hole of the spacer core is composed of at least two stages with different diameters.

2. In Paragraph 1, A battery electrode coating device having a fastening groove formed in the coating die above, into which the fastening part is screw-fastened.

3. In Paragraph 1, A battery electrode coating device in which at least one of the portions of the above-mentioned fastening part located within the through hole has an outer surface that is in surface contact with the inner surface of the through hole.

4. In Paragraph 1, The above fastening part is, A screw portion having a portion located within the through hole and the remainder screwed to the coating die, with threads formed on all or part thereof; and A battery electrode coating device comprising: a tolerance improvement portion formed between the head portion and the screw portion, having a larger diameter than the screw portion and located within the through hole.

5. In Paragraph 4, A battery electrode coating device in which the above-mentioned through hole is formed as a single step with a constant inner diameter.

6. In Paragraph 4, The above through hole is, A threaded hole through which the above-mentioned threaded portion passes; and A battery electrode coating device comprising: a tolerance improvement part through hole that is connected to the above-mentioned screw part through hole, has an inner diameter larger than the screw part through hole, and through which the above-mentioned tolerance improvement part passes.

7. In Paragraph 6, A battery electrode coating device in which the above-mentioned tolerance improvement part is formed as a single step with a constant diameter, and the above-mentioned tolerance improvement part through hole is formed as a single step with a constant inner diameter.

8. In Paragraph 6, A battery electrode coating device wherein the tolerance improvement part is formed in at least two stages with different diameters, the through hole of the tolerance improvement part is formed in at least two stages with different inner diameters, and a step difference is formed between each stage.

9. In Paragraph 8, The above-mentioned tolerance improvement unit is, A first tolerance improvement part connected to the above screw part and having a larger diameter than the screw part; and A battery electrode coating device comprising: a second tolerance improvement portion formed between a first tolerance improvement portion and a head portion, the second tolerance improvement portion having a larger diameter than the first tolerance improvement portion.

10. In Paragraph 9, The through hole in the above-mentioned tolerance improvement part is, A first tolerance improvement part through hole connected to the above-mentioned screw part through hole, having an inner diameter larger than the screw part through hole, and through which the above-mentioned first tolerance improvement part passes; and A battery electrode coating device comprising: a second tolerance improvement part through hole connected to the first tolerance improvement part through hole, having an inner diameter larger than the first tolerance improvement part through hole, and through which the second tolerance improvement part passes.

11. In Paragraph 1, A battery electrode coating device in which the above spacer shim is fixed to the coating die using at least two of the above fixing members.

12. In Paragraph 11, A battery electrode coating device in which the above spacer shim is fixed to the coating die using three of the above fixing members, and the three fixing members are positioned on the vertices of a virtual isosceles triangle.

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