Electrode assembly manufacturing equipment

Abstract

The present invention relates to an electrode assembly manufacturing apparatus including a fixing unit that holds and fixes a laminate having at least one first electrode, a separation membrane, and a second electrode stacked therein, and a press unit that heats and presses the fixing unit, the fixing unit including two or more parts having different properties.

Description

[Technical Field]

[0001] This application claims the benefit of the filing date of Korean Patent Application No. 10-2022-0037935, filed with the Korean Intellectual Property Office on March 28, 2022, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to an apparatus for manufacturing an electrode assembly, and more particularly, to an apparatus for manufacturing an electrode assembly that can prevent lifting or wrinkling of the electrode assembly by increasing a heat transfer rate to the electrode assembly during bonding of the electrode assembly. [Background technology]

[0003] Secondary batteries, unlike primary batteries, are rechargeable and have the potential to be small and have large capacities. As technological development and demand for mobile devices increases, the demand for secondary batteries as an energy source is rapidly increasing.

[0004] Secondary batteries are classified into coin-type batteries, cylindrical batteries, prismatic batteries, and pouch-type batteries depending on the shape of the battery case. The electrode assembly attached to the inside of the battery case in a secondary battery is a power generating element that can be charged and discharged and is made up of a laminated structure of electrodes and a separator.

[0005] Electrode assemblies can be broadly classified into a jelly-roll type in which a sheet-like positive electrode and negative electrode coated with an active material are wound up with a separator interposed between them; a stack type in which multiple positive electrodes and negative electrodes are stacked in order with a separator interposed between them; and a stack-and-fold type in which stack-type unit cells are wound up with a long separator film.

[0006] In a conventional process for manufacturing a stack-and-fold type electrode assembly, the electrode and separator are laminated and heated and pressurized in a hot press to bond the electrode and separator while the electrode assembly is fixed with a gripper or a fixing part to prevent the electrode assembly from shifting.

[0007] However, conventional electrode assembly manufacturing processes have limitations in ensuring uniformity in adhesive strength of electrode assemblies due to problems such as a reduced heat transfer rate from the heating press to the electrode assembly due to the use of grippers or fixing parts, uneven heat transfer, reduced adhesive strength between the electrode and the separator, and differences in adhesive strength depending on the position of the electrode assembly. Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention aims to solve the problems of the prior art by providing an electrode assembly manufacturing apparatus that can increase the heat transfer rate from a press part to an electrode assembly and ensure uniformity in the adhesive strength of the electrode assembly. [Means for solving the problem]

[0009] One embodiment of the present invention provides an electrode assembly manufacturing device including a fixing unit that grips and fixes a laminate including at least one first electrode, a separator, and a second electrode, and a press unit that heats and presses the fixing unit, wherein the fixing unit includes two or more parts having different properties.

[0010] One embodiment of the present invention provides an electrode assembly manufacturing apparatus, wherein the fixing portion includes a central portion including a surface that contacts the laminate, and an edge portion that surrounds the central portion, and the central portion and the edge portion are made of different materials.

[0011] One embodiment of the present invention provides an apparatus for manufacturing an electrode assembly, wherein the central portion has a higher thermal conductivity than the edge portions, and the edge portions have a higher strength than the central portion.

[0012] One embodiment of the present invention provides an apparatus for manufacturing an electrode assembly, wherein the central portion includes any one of silver, copper, gold, aluminum, and duralumin.

[0013] One embodiment of the present invention provides an apparatus for manufacturing an electrode assembly, wherein the edge portion includes any one of steel series, carbon steel, stainless steel, and engineering plastic.

[0014] One embodiment of the present invention provides an apparatus for manufacturing an electrode assembly, wherein the central portion occupies 40% to 90% of the total area of ​​the fixing portion (100%), and the edge portion occupies 10% to 60% of the total area of ​​the fixing portion (100%).

[0015] One embodiment of the present invention provides an apparatus for manufacturing an electrode assembly, wherein the edge does not contact the laminate.

[0016] One embodiment of the present invention provides an apparatus for manufacturing an electrode assembly, wherein the center portion and the edge portion are spaced apart from each other.

[0017] One embodiment of the present invention provides an apparatus for manufacturing an electrode assembly, further comprising a connecting portion connecting the center portion and the edge portion.

[0018] One embodiment of the present invention provides an apparatus for manufacturing an electrode assembly, wherein the connecting portion connects the center portion and the edge portion by either a rivet connection or a T-screw connection.

[0019] One embodiment of the present invention provides an electrode assembly manufacturing apparatus, wherein the fixing portion includes a pair of fixing blocks that move in opposite directions to each other and apply surface pressure to one or more of the laminates.

[0020] In one embodiment of the present invention, there is provided an apparatus for manufacturing an electrode assembly, wherein the pair of fixing blocks have flat pressure surfaces that come into contact with and press the laminate.

[0021] In one embodiment of the present invention, the press unit includes a pair of heating blocks, each of which has a heating plate provided on one surface thereof that contacts the fixing unit.

[0022] In one embodiment of the present invention, the press unit includes a pair of heating blocks, each of which includes a heating unit therein. [Effects of the Invention]

[0023] According to the electrode assembly manufacturing apparatus according to the embodiment of the present invention, the heat transfer rate from the press part to the electrode assembly can be increased, thereby ensuring uniform adhesion of the electrode assembly. [Brief explanation of the drawings]

[0024] [Figure 1] FIG. 2 is a side view illustrating the concept of applying heat and pressure to a laminate using a fixing unit and a press unit according to one embodiment of the present invention. [Figure 2] 1A is a plan view showing a fixing part according to an embodiment of the present invention, and FIG. 1B is a cross-sectional view showing a fixing part according to an embodiment of the present invention. [Figure 3] FIG. 10 is a cross-sectional view showing a fixing part according to another embodiment of the present invention. [Figure 4] 4(a) is a plan view illustrating the concept of connecting a coupling part to a fixing part according to one embodiment of the present invention, and FIG. 4(b) is a cross-sectional view taken along line A-A' in FIG. 4(a). [Figure 5] 5(a) is a plan view illustrating the concept of combining the fixing part and the coupling part in another embodiment of the present invention, (b) is a cross-sectional view taken along line B-B' in (a) of FIG. 5, and (c) is a cross-sectional view taken along line C-C' in (a) of FIG. 5. [Figure 6] 1 illustrates cross-sectional structures of a center portion and an edge portion according to an embodiment of the present invention. [Explanation of symbols]

[0025] 100 Electrode assembly manufacturing apparatus 10...Fixed part 11 First fixed block 12 Second fixed block 20 Press Department 21 First heating block 22 Second heating block 23...heating plate 30...joint part C...Central part C1...Protrusion S Edge S1: First edge S2...Second edge DETAILED DESCRIPTION OF THE INVENTION

[0026] The detailed description of the present invention is intended to fully explain the present invention to those skilled in the art. Throughout the specification, when a part is described as "comprising" a certain element or as "featuring" a certain structure and shape, this does not mean that other elements are excluded or that other structures and shapes are excluded, but that other elements, structures and shapes may be included, unless otherwise specified to the contrary.

[0027] Since the present invention can be modified in various ways and can have various embodiments, specific embodiments will be presented and described in detail in the detailed description, but this is not intended to limit the content of the invention to the embodiments, and it should be understood that the present invention includes all modifications, equivalents, or alternatives that fall within the spirit and technical scope of the present invention.

[0028] The present invention will be described in detail below with reference to the drawings. However, the drawings are for illustrative purposes only and the scope of the present invention is not limited by the drawings.

[0029] FIG. 1 is a side view illustrating the concept of applying heat and pressure to a laminate by a fixing unit 10 and a pressing unit 20 according to one embodiment of the present invention.

[0030] Fixing unit 10 grips and fixes a laminate in which one or more first electrodes, separators, and second electrodes are stacked, and may include a pair of fixing blocks. That is, fixing unit 10 includes first fixing block 11 and second fixing block 12, and first and second fixing blocks 11 and 12 are moved in directions facing each other to apply surface pressure to one or more of the laminate to fix the laminate.

[0031] The first and second fixing blocks 12 may have flat pressure surfaces that come into contact with and apply pressure to the laminate. Here, the pressure surfaces are the surfaces of the first and second fixing blocks 12 that come into contact with the laminate, and may be provided in a shape that corresponds to the planar cross-sectional shape of the laminate.

[0032] The fixing part 10 may include two or more parts having different properties. The fixing part 10 may include a central part C and an edge part S surrounding the central part C.

[0033] FIG. 2(a) is a plan view showing a fixing portion 10 according to an embodiment of the present invention, and FIG. 2(b) is a side view showing a fixing portion 10 according to an embodiment of the present invention.

[0034] In one embodiment, the first and second fixing blocks 12 include a central portion C including a surface that contacts the laminate, and an edge portion S that surrounds the central portion C, and the central portion C and the edge portion S may be provided as different materials.

[0035] The central portion C may occupy 40% to 90% of the total area of ​​the fixing part 10, which is 100%, and the edge portion S may occupy 10% to 60% of the total area of ​​the fixing part 10, which is 100%.

[0036] The area of ​​the surface of the central portion C that comes into contact with the laminate may correspond to the cross-sectional area of ​​the laminate or may be larger than the cross-sectional area of ​​the laminate. The cross-sectional area of ​​the laminate may refer to the area of ​​the surface when the laminate is cut into a flat surface.

[0037] The central portion C may include a material having a higher thermal conductivity than the edge portion S, and may include a material having a lower strength than the edge portion S. The edge portion S may include a material having a higher strength than the central portion C.

[0038] The edges S are located at the side edges of the central portion C and may not contact the laminate.

[0039] For example, the central portion (C) may include any of silver, copper, gold, aluminum, and duralumin, and the edge portion S may include any of steel (SUS) series, carbon steel, stainless steel, and engineering plastic.

[0040] The steel (SUS) series may include either stainless steel or chromium, molybdenum, titanium, and niobium.

[0041] The engineering plastic may be one or more selected from the group consisting of polyamide (PA), polyacetal (POM), polycarbonate (PC), modified polyphenylene ether (PPE), polybutylene terephthalate (PBT), GF-reinforced polyethylene terephthalate (GF-PET), ultra-high molecular weight polyethylene (UHPE), polysulfone (PSF), polyethersulfone (PES), polyphenylene sulfide (PPS), polyarylate (PAR), polyamideimide (PAI), polyetherimide (PEI), polyetheretherketone (PEEK), polyimide (PI), liquid crystal polyester (LCP), polytetrafluoroethylene (PTFE), polyaminobismaleimide (PABM), and polybisamidotriazole (BT). Preferably, the engineering plastic is polyetheretherketone.

[0042] The area occupied by the edge S on one surface of the fixing part 10 that comes into contact with the laminate may be different from the area occupied by the edge S on the opposite surface (the other surface of the fixing part 10). In other words, the length of the central part C that occupies the other surface of the fixing part 10 may be shorter than the length of the central part C that occupies one surface of the fixing part 10. Here, the length of the central part C means the longest length among the lengths perpendicular to the stacking direction of the laminate.

[0043] FIG. 6 illustrates the cross-sectional structure of the center portion C and the edge portion S according to an embodiment of the present invention.

[0044] For example, the length of the central portion C may increase at a constant rate from the other surface toward the one surface, and the boundary between the central portion C and the edge portion S may be formed by a diagonal line. Alternatively, the length of the central portion C may change once from the other surface toward the one surface of the fixing part 10, and the cross section of the central portion C may be formed in a stepped shape.

[0045] In this case, the surface of the edge portion S facing the side surface of the center portion C is provided to correspond to the shape of the side surface of the center portion C, and there are no particular limitations on the size and shape thereof.

[0046] That is, when the length of the center portion C increases at a constant rate from the other side to the one side, the edge portion S may be provided in the shape of a right-angled inverted triangle or a parallelogram.

[0047] And, based on the area of ​​one surface of the fixing part 10 being 100%, the edge part S can occupy 0% or more and 40% or less.

[0048] The fixing part 10 may be provided with a center C and an edge S spaced apart from each other. In this case, the distance between the center C and the edge S may be such that the shape of the fixing part 10 is not deformed when the center C and the edge S thermally expand at the process temperature, i.e., the distance may be such that the expansion length of the center C and the edge S can be accommodated.

[0049] The fixing part 10 includes different materials, and the two materials may have different thermal expansion coefficients.

[0050] When heat is supplied to the fixing part 10 from the pressing part 20, the two types of materials will each thermally expand, and at this time, interference may occur due to the difference in the thermal expansion coefficients of the different materials, which may cause the fixing part 10 to bend or deform.

[0051] 3 is a side view of a fixture 10 according to another embodiment of the present invention. For example, the fixture 10 may have a central portion C made of aluminum and an edge portion S made of steel. The thermal expansion coefficient of aluminum is 24×10 -6 / ℃, and steel is 13×10 -6 / °C. In addition, the length LC of the center C of the fixing part 10 is 100 mm, and the length LS of the edge S is 50 mm. The center C receives heat from the press part 20, causing the temperature to rise to 100°C, and the edge S receives partial heat from the center C, causing the temperature to rise to 30°C.

[0052] At this time, the expansion length of the central portion C is 0.24 mm and the expansion length of the edge portion S is 0.0195 mm, so the separation distance L between the central portion C and the edge portion S is set to 0.26 mm or more, thereby preventing interference due to thermal expansion between the central portion C and the edge portion S and preventing the fixing portion 10 from bending or deforming.

[0053] The electrode assembly manufacturing apparatus 100 may further include a connecting unit 30 that connects the center portion C and the edge portion S of the fixing unit 10. The connecting unit 30 connects the center portion C and the edge portion S of the fixing unit 10 while the center portion C and the edge portion S are spaced apart, and the fixing unit 10 can connect the center portion C and the edge portion S by either rivet connection or T-screw connection.

[0054] Figure 4(a) is a plan view illustrating the concept of connecting a connecting portion 30 to a fixed portion 10 according to one embodiment of the present invention, Figure 4(b) is a cross-sectional view taken along A-A' in Figure 4(a), Figure 5(a) is a plan view illustrating the concept of connecting a fixed portion 10 and a connecting portion 30 according to another embodiment of the present invention, Figure 5(b) is a cross-sectional view taken along B-B' in Figure 5(a), and Figure 5(c) is a cross-sectional view taken along C-C' in Figure 5(a).

[0055] 4(a) and 4(b), the central portion C of the fixing part 10 according to one embodiment includes a first protrusion C1 protruding in the width direction of the central portion C, and at least one first protrusion C1 may be provided. Here, the width direction of the central portion C may refer to the longest direction from one end face to the other end face of the central portion C, among directions perpendicular to the pressing direction of the pressing part 20.

[0056] For example, the central portion C may have a pair of first protrusions C1 on opposite sides thereof, and the pair of first protrusions C1 may be spaced apart from each other.

[0057] Alternatively, the protrusion C1 may be provided along the side surface of the central portion C, and the protrusion C1 may be provided at a height lower than the height of the central portion C. One surface of the protrusion C1 may be located on the same line as one surface of the central portion C. Here, the central portion C and one surface and the other surface of the protrusion C1 refer to the surfaces facing the press portion 20, and the side surface may refer to the surface connecting the one surface and the other surface.

[0058] For example, the protrusion C1 may be provided in a stepped shape with one change in length in the width direction of the central portion C.

[0059] At this time, the connecting portion 30 can be connected to a position corresponding to the position of the protruding portion C1, and the connecting portion 30 can penetrate the edge portion S from the other surface of the fixing portion 10 in one direction like a rivet and be fixed to the center portion C to connect the center portion C and the edge portion S. The edge portion S through which the connecting portion 30 penetrates may be a region laminated on the other surface of the protruding portion C1.

[0060] Alternatively, the connecting portion 30 may be fixed to the center portion C by passing through the edge portion S in the direction from one side surface of the fixing portion 10 to the other side surface.

[0061] That is, the coupling portion 30 may completely penetrate the edge portion S, and only a portion of the coupling portion 30 may be inserted into the center portion C.

[0062] The edge portion S may include a coupling hole (not shown) into which the coupling portion 30 is inserted, and the coupling portion 30 may be inserted into the coupling hole and retracted to the center portion C. In this case, the coupling portion 30 may be positioned apart from the inner surface of the coupling hole.

[0063] That is, in one embodiment, the fixing portion 10 may include a separation distance between the central portion C and the edge portion S and between the coupling hole and the coupling portion 30 so as to accommodate the increased length or width of the central portion C when the central portion C increases in volume due to thermal expansion.

[0064] If the connecting portion 30 includes a head that protrudes after being connected to the fixing portion 10, such as a round rivet, a round head rivet, a flat rivet, a flat head rivet, a T-shaped screw, etc., the edge S may further include a groove of a certain depth in the portion where the head of the connecting portion 30 is located.

[0065] 5(a), 5(b), and 5(c), in another embodiment of the fixing part 10, the protrusion C1 may be provided along the side of the central part C and positioned at the center of the side of the central part C. That is, in another embodiment of the fixing part 10, one and the other surfaces of the protrusion C1 may not be positioned on the same line as the one and the other surfaces of the central part C.

[0066] The edge portion S may have a receiving groove S1 that can receive the protrusion C1 protruding from the side of the center portion C. The protrusion C1 and the receiving groove (not shown) may be positioned apart from each other. For example, the edge portion S may have a U-shaped or H-beam cross section.

[0067] The edge portion S may include a first edge portion S1 and a second edge portion S2 for positioning the protrusion C1 in the receiving groove S1, and the coupling portion 30 can fix the first and second edge portions S1 and S2.

[0068] For example, the edge portion S may be configured to surround the central portion C and may be provided in a frame shape based on the plan view of the fixed portion 10, in which case the first edge portion S1 may be provided in a "C" shape and the second edge portion S2 may be provided in an "I" shape.

[0069] The connecting portion 30 penetrates from one side of the edge portion S to the other side of the edge portion S at the portion where the first and second edge portions S1, S2 contact each other, and can connect the first and second edge portions S1, S2.

[0070] The central portion C is provided with a receiving groove that fits into the protrusion C1, so that the structure for fixing the central portion C to the edge portion S can be omitted, and there can be no separation between the connecting portion 30 and the edge portion S.

[0071] The pressing unit 20 heats and presses the fixing unit 10, and may include a pair of heating blocks 21 and 22. That is, the pressing unit 20 includes a first heating block 21 and a second heating block 22, and the first and second heating blocks 21 and 22 are moved in directions facing each other to pressurize and supply heat to one side of each of the first and second fixing blocks 12.

[0072] The pair of heating blocks 21 and 22 may each include a heating surface that comes into contact with the fixed portion 10 and heats the fixed portion 10 .

[0073] In one embodiment, the pressing unit 20 may be provided in a form in which a heating plate 23 is provided on the heating surfaces of a pair of heating blocks 21 and 22. In this case, the heating plate 23 may be provided so that the surface that comes into contact with the fixing unit 10 is flat.

[0074] In another embodiment, the press unit 20 may include a heating unit (not shown) therein. The heating unit may be included in the press unit 20 in the form of a wire, plate, rod, or the like that is heated by supplying electricity.

[0075] In this case, the pressing part 20 may include a thermally conductive material to transfer the heat generated from the heating part to the fixing part 10 .

[0076] The heating plate 23 and the heating unit may be supplied with power from an external power source, or a power source may be further included on the other side of the pressing unit 20, and the heating plate 23 may be supplied with power from a power source connected to the pressing unit 20.

[0077] The electrode assembly manufacturing apparatus 100 may further include a pre-treatment unit (not shown). The pre-treatment unit prepares a laminate to be supplied to the fixing unit 10, and may further include a first electrode supply unit, a separation membrane supply unit, and a second electrode supply unit.

[0078] The first electrode, separation membrane, and second electrode may be supplied to fixing unit 10. For example, when the first electrode, separation membrane, and second electrode are supplied to first fixing block 11, second fixing block 12 can move toward first fixing block 11 to fix the stacked structure. In other words, of the pair of fixing blocks 11, 12, the fixing block to which the first electrode, separation membrane, and second electrode are supplied and stacked may not move and may remain in a fixed position.

[0079] While the present invention has been described above with reference to preferred embodiments, it will be understood by those skilled in the art that various modifications and variations can be made thereto without departing from the spirit and scope of the invention as set forth in the following claims.

Claims

1. a fixing portion that grips and fixes a stack of at least one first electrode, a separation membrane, and a second electrode; and a press unit that heats and presses the fixing unit, the fixing portion includes two or more portions having different properties from each other, the fixing portion includes a central portion including a surface that contacts the laminate, and an edge portion that surrounds the central portion; the central portion and the edge portion are made of different materials; the central portion has a higher thermal conductivity than the edge portion; The edge portion has a greater strength than the center portion.

2. A fixing portion that grips and fixes a laminate in which at least one first electrode, a separation membrane, and a second electrode are stacked; and a press unit that heats and presses the fixing unit, the fixing portion includes two or more portions having different properties from each other, the fixing portion includes a central portion including a surface that contacts the laminate, and an edge portion that surrounds the central portion; the central portion and the edge portion are made of different materials; The apparatus for manufacturing an electrode assembly, wherein the central portion includes any one of silver, copper, gold, aluminum, and duralumin.

3. A fixing portion that grips and fixes a laminate in which at least one first electrode, a separation membrane, and a second electrode are stacked; and a press unit that heats and presses the fixing unit, the fixing portion includes two or more portions having different properties from each other, the fixing portion includes a central portion including a surface that contacts the laminate, and an edge portion that surrounds the central portion; the central portion and the edge portion are made of different materials; The manufacturing apparatus for an electrode assembly, wherein the edge portion includes any one of steel series, carbon steel, stainless steel, and engineering plastic.

4. A fixing portion that grips and fixes a laminate in which at least one first electrode, a separation membrane, and a second electrode are stacked; and a press unit that heats and presses the fixing unit, the fixing portion includes two or more portions having different properties from each other, the fixing portion includes a central portion including a surface that contacts the laminate, and an edge portion that surrounds the central portion; the central portion and the edge portion are made of different materials; the central portion occupies 40% to 90% of the total area of ​​the fixing portion, based on 100%; The edge portion occupies 10% to 60% of the total area of ​​the fixing portion, based on 100%.

5. A fixing portion that grips and fixes a laminate in which at least one first electrode, a separation membrane, and a second electrode are stacked; and a press unit that heats and presses the fixing unit, the fixing portion includes two or more portions having different properties from each other, the fixing portion includes a central portion including a surface that contacts the laminate, and an edge portion that surrounds the central portion; the central portion and the edge portion are made of different materials; The device for manufacturing an electrode assembly, wherein the edge does not contact the laminate.

6. A fixing part that grips and fixes a laminate in which at least one first electrode, a separation membrane, and a second electrode are stacked; and a press unit that heats and presses the fixing unit, the fixing portion includes two or more portions having different properties from each other, the fixing portion includes a central portion including a surface that contacts the laminate, and an edge portion that surrounds the central portion; the central portion and the edge portion are made of different materials; The central portion and the edge portion are spaced apart from each other.

7. The electrode assembly manufacturing apparatus according to claim 6 , further comprising a connecting portion that connects the center portion and the edge portion.

8. The electrode assembly manufacturing apparatus according to claim 7 , wherein the connecting portion connects the center portion and the edge portion by either a rivet connection or a T-screw connection.

9. The fixing portion includes a pair of fixing blocks, The electrode assembly manufacturing apparatus according to claim 1 , wherein the pair of fixing blocks move in directions opposite to each other to apply pressure to one or more surfaces of the laminate.

10. The electrode assembly manufacturing apparatus according to claim 9 , wherein the pair of fixing blocks have flat pressure surfaces that come into contact with and press the laminate.

11. the press section includes a pair of heating blocks; The electrode assembly manufacturing apparatus according to claim 1 , wherein each of the pair of heating blocks has a heating plate provided on one surface that contacts the fixing portion.

12. the press unit includes a pair of heating blocks; The electrode assembly manufacturing apparatus according to claim 1 , wherein each of the pair of heating blocks includes a heating portion therein.

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