Electrode assembly manufacturing method and electrode assembly manufacturing apparatus

Abstract

The present application relates to an apparatus for manufacturing an electrode assembly and a method for manufacturing an electrode assembly.

Description

[Technical field]

[0001] This application claims priority to Korean Patent Application No. 10-2021-0090596 filed on July 9, 2021, Korean Patent Application No. 10-2021-0090592 filed on July 9, 2021, Korean Patent Application No. 10-2021-0090597 filed on July 9, 2021, and Korean Patent Application No. 10-2021-0090598 filed on July 9, 2021, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a method and an apparatus for manufacturing an electrode assembly. [Background technology]

[0003] Unlike primary batteries, secondary batteries are rechargeable and have the potential to be small and have large capacity, so they have been the subject of much research and development in recent years. As technological development and demand for mobile devices increases, the demand for secondary batteries as an energy source is growing rapidly.

[0004] Secondary batteries are classified into coin-type batteries, cylindrical batteries, square batteries, and pouch-type batteries according to the shape of the battery case. The electrode assembly attached inside the battery case of a secondary battery is a power generating element capable of charging and discharging, which is made of a laminated structure of electrodes and a separator.

[0005] The electrode assemblies can be generally classified into a jelly-roll type, a stack type, and a stack-and-folding type. In the jelly-roll type, a separator is interposed between a sheet-like anode and cathode coated with an active material, and the entire arrangement is wound up. In the stack type, a number of anodes and cathodes are stacked in sequence with a separator interposed therebetween. In the stack-and-folding type, stacked unit cells are wound up with a long length of separator film.

[0006] In the stack-and-fold type electrode assembly, the separator is folded in a zigzag pattern and the electrodes are positioned therebetween, which causes a problem of distorted electrode positions. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Korean Patent Publication No. 10-2013-0132230 Summary of the Invention [Problem to be solved by the invention]

[0008] First, the present invention provides a method and apparatus for manufacturing an electrode assembly that prevents cell damage and deformation of mechanical parts during the manufacturing process of an electrode assembly prepared by stacking electrodes and a separator.

[0009] The present invention also provides an apparatus for manufacturing an electrode assembly, which can prevent the electrodes from being distorted during the manufacturing process. [Means for solving the problem]

[0010] An embodiment of the present invention provides a method for manufacturing an electrode assembly. The method according to the embodiment of the present invention preferably includes the steps of assembling an electrode stack, performing a first heat press operation on the electrode stack, and then performing a second heat press operation on the electrode stack. In the step of assembling the electrode stack, the electrode stack preferably includes a plurality of electrodes stacked along a stacking axis and individual separation membrane parts located between each electrode. In the first heat press operation, the electrode stack may be coupled with a gripper to secure the position of the electrode stack. Then, while the gripper is coupled with the electrode stack, heat and pressure may be applied to the electrode stack as part of the first heat press operation. In the second heat press operation, the gripper may be separated from the electrode stack and then heat and pressure may be applied to the electrode stack as part of the second heat press operation. Furthermore, the second heat press operation preferably includes the step of applying heat and pressure to the electrode stack for 5 to 60 seconds under a temperature condition of 50°C to 90°C and a pressure condition of 1Mpa to 6Mpa.

[0011] According to one embodiment of the present invention, the separator may be a part of an elongated separator sheet. In this aspect of the present invention, the step of assembling the electrode stack may include stacking a first electrode and a second electrode alternately on an elongated separator sheet. Also, the elongated separator sheet may be folded sequentially onto one of the first and second electrodes that have been previously stacked before stacking one of the first and second electrodes.

[0012] According to another embodiment of the present invention, an apparatus for manufacturing an electrode assembly is provided. The electrode assembly may include an electrode stack having a plurality of first and second electrodes stacked along a stacking axis and a separate separator membrane portion positioned between each of the electrodes. The apparatus according to the embodiment of the present invention preferably includes a press unit and a gripper. The press unit applies heat and pressure to the electrode stack to bond the electrodes and separator membrane portions in the electrode stack. The gripper is coupled to the electrode stack to fix the position of the electrode stack when the heat and pressure are applied to the electrode stack by the press unit. Preferably, the gripper and the press unit are configured to apply heat and pressure while the gripper is coupled to the electrode stack and while the gripper is separated from the electrode stack.

[0013] According to one embodiment of the present invention, the apparatus may further include a stack table that supports the electrode stack; a separation membrane supplying unit that supplies a separation membrane to the stack table; a first electrode supplying unit that supplies the first electrode to the stack table; a second electrode supplying unit that supplies the second electrode; a first electrode stacking unit that moves the first electrode supplied from the first electrode supplying unit to the stack table; and a second electrode stacking unit that moves the second electrode supplied from the second electrode supplying unit to the stack table.

[0014] According to another embodiment of the invention, the apparatus may further include a rotating unit for rotating the stack table between a first position and a second position, the first position may be toward the first electrode stack unit to receive the first electrode from the first electrode stack unit, and the second position may be toward the second electrode stack unit to receive the second electrode from the second electrode stack unit. Effect of the Invention

[0015] According to the present invention, by heating and pressing the entire stack in the press, the electrodes can be bonded to the separator without having to heat and / or press each step of the electrode assembly where the electrodes and separator are heated and stacked (i.e., heating and / or pressing each electrode and separator pair at each step of the process), which can prevent harmful accumulation of heat and / or pressure on lower separators in the stack, thereby reducing the possibility of damage and deformation of the components of the electrode assembly.

[0016] In addition, the present invention can advantageously reduce variations in the adhesive strength between the electrode and the separator, the air permeability of the separator, and the thickness of the manufactured electrode assembly, thereby increasing uniformity.

[0017] By compressing the entire laminated stack in the press, the present invention also preferably reduces distortion or shifting of the electrode positions within the electrode stack, which can advantageously reduce manufacturing time as well as increase the energy density of the produced electrode assemblies. [Brief description of the drawings]

[0018] [Figure 1] 1A and 1B are schematic diagrams illustrating a method for manufacturing an electrode assembly according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a top view showing an example of an apparatus for manufacturing an electrode assembly according to an embodiment of the present invention. [Diagram 3] 1 is a front elevation view conceptually illustrating an apparatus for manufacturing an electrode assembly according to an embodiment of the present invention; [Figure 4] 2 is a cross-sectional view illustrating an electrode assembly manufactured by an apparatus for manufacturing an electrode assembly according to an embodiment of the present invention; [Diagram 5] 1 is a perspective view showing a pressing unit in an apparatus for manufacturing an electrode assembly according to an embodiment of the present invention; [Figure 6] 4 is a perspective view illustrating an example of a state in which a press unit presses a laminate in the electrode assembly manufacturing apparatus according to the embodiment of the present invention. FIG. [Figure 7] 1 is a perspective view showing a stack table in an electrode assembly manufacturing apparatus according to an embodiment of the present invention; [Figure 8] 1 is a perspective view showing a first electrode mounting table in an electrode assembly manufacturing apparatus according to an embodiment of the present invention; [Figure 9] 1 is a perspective view showing a second electrode mounting table in an electrode assembly manufacturing apparatus according to an embodiment of the present invention; [Figure 10] 1 is a perspective view showing a first suction head of an electrode assembly manufacturing apparatus according to an embodiment of the present invention; [Figure 11] FIG. 11 is a bottom view of the first suction head of FIG. 10 in accordance with one embodiment of the present invention. [Figure 12] FIG. 1 is a top view showing a holding mechanism and a stack table in an electrode assembly manufacturing apparatus according to one embodiment of the present invention. [Figure 13] FIG. 13 is a front elevation view conceptually showing an apparatus for manufacturing an electrode assembly according to another embodiment of the present invention. [Figure 14] 1 is a perspective view of a separation membrane heating section of a separation membrane supply section according to an embodiment of the present invention; [Figure 15A] FIG. 2 is a perspective view showing a first pressing section according to an embodiment of the present invention. [Figure 15B] FIG. 2 is a perspective view showing a second pressing section according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] The object, specific advantages, and novel features of the present invention will become more apparent from the following detailed description in conjunction with the accompanying drawings and embodiments. In this specification, when adding reference numbers to components in each drawing, it should be noted that the same components are given the same numbers even if they are displayed in different drawings. Furthermore, the present invention may be embodied in several different forms and is not limited to the embodiments described in this specification. In addition, in describing the present invention, detailed descriptions of related known technologies that may unnecessarily obscure the gist of the present invention will be omitted.

[0020] According to an embodiment of the present invention, a method for manufacturing an electrode assembly may be provided. The method may include the steps of: providing a first electrode on a stack table; providing a second electrode on the stack table; providing a separator on the stack table; and assembling a stack on the stack table by alternately stacking the first and second electrodes on the separator, and the separator may be folded sequentially onto one of the first and second electrodes that have been previously stacked before a subsequent electrode of the first and second electrodes is stacked. After assembling the stack, the method may include the step of performing a first heat press operation including gripping the stack with a gripper and applying heat and pressure. After performing the first heat press operation, the method may further include the step of performing a second heat press operation including removing the gripper and applying heat and pressure to the stack. The second heat press operation may include the step of pressing the stack for 5 to 60 seconds at a temperature condition of 50° C. to 90° C. and a pressure condition of 1 MPa to 6 MPa.

[0021] In one embodiment of the present invention, the first heat press operation may include the steps of pressing the top surface of the stack with the gripper to fix the laminate; heating the stack table and / or a pair of pressurizing blocks; and pressing the laminate between the pair of heated and pressurizing blocks or between the pressurizing blocks and the stack table (either one or both may be heated).

[0022] In one embodiment of the present invention, the first electrode, the second electrode, and the separation membrane may be supplied to the stack table in a heated state, which means that the first electrode, the second electrode, and the separation membrane may be heated by a commonly used method before being supplied to the stack table, as long as the first electrode, the second electrode, and the separation membrane are not damaged by such heating.

[0023] In one embodiment of the present invention, the first heat pressing operation may include a step of heating and pressing the laminate for 10 to 30 seconds under temperature conditions of 65°C to 90°C and pressure conditions of 1 MPa to 3 MPa. More preferably, the first heat pressing operation may include a step of heating and pressing the laminate for 10 to 20 seconds under temperature conditions of 65°C to 75°C and pressure conditions of 1.5 MPa to 2 MPa.

[0024] In one embodiment of the present invention, the second heat press operation includes the steps of: ceasing heating of the stack table and / or the pair of pressurizing blocks; ceasing pressurization of the stack; moving the gripper away from the stack; heating the stack table and / or the pair of pressurizing blocks to transfer heat to the stack; and pressing the stack between the pair of pressurizing blocks and / or pressing the stack between the pressurizing blocks and the stack table (any one or both may be heated).

[0025] In one embodiment of the present invention, the pair of pressurizing blocks include a pressurizing heater for heating the pair of pressurizing blocks, and the pair of pressurizing blocks can heat the stack. That is, in one embodiment of the present invention, the step of heating and pressurizing the stack may include the step of heating and pressurizing the stack with the pair of pressurizing blocks. In some embodiments of the present invention, the stack table may also include a stack table heater for heating the stack table body and transferring heat to the stack.

[0026] In an alternative embodiment of the invention, one or both of the heat pressing operations may originate from the stack table. In such a case, only one of the pressure blocks may be used to press the top of the stack against the stack table. The gripper may then be a holding mechanism for the stack table capable of stabilizing the stack by fixing the position of the stack relative to the stack table. The holding mechanism may also be configured to hold the stack in this manner during at least a first heat pressing operation.

[0027] In this specification, FIG. 1 is a schematic diagram showing a method for manufacturing an electrode assembly according to an embodiment of the present invention. That is, referring to FIG. 1, the method may first include a stacking process in which first and second electrodes are alternately stacked on a separator to form a stack cell on a stack table, in which the separator is folded sequentially onto one of the first and second electrodes that have been stacked before the subsequent electrode. The first and second electrodes are stacked. After the stacking process, the stack may be removed from the stack table. During this time, the separator is pulled and cut after being pulled by a predetermined length. Then, a predetermined length of the cut end of the separator is wound around the stack cell. The movement of the stack away from the stack table may be performed by a gripper, and the gripper is preferably a movable component that can grip the stack on the stack table and then move it to a press unit where a heat press operation is performed. Then, a first heat press operation is performed while the wound stack cell is gripped by the gripper. After the first heat pressing operation is completed, the gripper releases the stack cell, and after the gripper is removed, a second heat pressing operation is performed. After the second heat pressing operation is completed, a completed electrode assembly can be completed.

[0028] In an embodiment of the present invention, the temperature condition of the second heat pressing operation may be 50° C. or higher, preferably 65° C. or higher.

[0029] In an embodiment of the present invention, the temperature condition of the second heat pressing operation may be 90° C. or less, preferably 85° C. or less.

[0030] In an embodiment of the present invention, the temperature condition of the second heat pressing operation may be 50° C. to 90° C., preferably 65° C. to 90° C., more preferably 65° C. to 85° C. Most preferably, the temperature condition of the second heat pressing operation may be 70° C.

[0031] In an embodiment of the present invention, the pressure condition of the second heat pressing operation may be 1 Mpa or more, preferably 1.5 Mpa or more, and more preferably 3 Mpa or more.

[0032] In an embodiment of the present invention, the pressure condition of the second heat pressing operation may be 6Mpa or less, preferably 5.5Mpa or less.

[0033] In an embodiment of the present invention, the pressure condition of the second heat pressing operation may be 1 Mpa to 6 Mpa, preferably 1.5 Mpa to 6 Mpa, and more preferably 3 Mpa to 5.5 Mpa.

[0034] In an embodiment of the present invention, the heating and pressing in the second heat pressing operation may be performed for 5 seconds or more, preferably 7 seconds or more.

[0035] In an embodiment of the present invention, the heating and pressing in the second heat pressing operation may be performed for 60 seconds or less, preferably 30 seconds or less, and more preferably 25 seconds or less.

[0036] In an embodiment of the present invention, the heating and pressing in the second heat pressing operation may be performed for 5 to 60 seconds, preferably 5 to 30 seconds, and more preferably 7 to 25 seconds.

[0037] In an embodiment of the present invention, the second heat pressing operation may include heating and pressing the laminate for 5 to 60 seconds under temperature conditions of 50°C to 90°C and pressure conditions of 1 MPa to 6 MPa, preferably for 5 to 30 seconds under temperature conditions of 65°C to 90°C and pressure conditions of 1.5 MPa to 6 MPa. More preferably, the second heat pressing operation may include a step of heating and pressing the laminate for 7 to 25 seconds under temperature conditions of 65°C to 85°C and pressure conditions of 3 MPa to 5.5 MPa. Here, it is most preferable that the temperature condition is 70°C.

[0038] Here, the pressure conditions of the first heat press operation and the pressure conditions of the second heat press operation refer to the pressure applied by the pair of pressure blocks (or the pressure blocks for the stack table), and the temperature conditions refer to the temperature of heat applied by the stack table and / or the pair of pressure blocks. Also, the pair of pressure blocks used in the first heat press operation and the second heat press operation may be the same or different. That is, in the first heat press operation, the laminate is gripped by a gripper and pressurized and heated by the pair of pressure blocks, and then, in the second heat press operation, the gripper is released and the laminate is pressurized and heated by the same pair of pressure blocks or a different pair of pressure blocks.

[0039] In an alternative embodiment where at least one of the heat pressing operations occurs from a stack table, the first heat pressing operation may include a pressurizing block that applies pressure to the stack placed on the stack table, as described above, where the laminate is heated by one or both of the heaters of the stack table and / or pressurizing block. During such first heat pressing operation, the laminate may be fixed to the stack table by a gripper in the form of a holding mechanism of the stack table. After the first heat pressing operation, a second heat pressing operation may be performed with the gripper released from the stack. Such a second heat pressing operation may be performed on the stack table under pressure by the same or a different pressurizing block. Alternatively, the laminate may be moved to a separate press section, where the second heat pressing operation may be performed by applying heat and pressure to the stack by a pair of pressurizing blocks of the press section.

[0040] If the temperature, pressure, and time conditions described herein are not met, the components of the electrode assembly will not adhere properly, which may cause the electrode assembly to break or the components inside the electrode assembly to become displaced, especially before the electrode assembly is inserted into the battery case. Also, problems with the separator having too high breathability may occur.

[0041] On the other hand, when performing the heat pressing operations disclosed herein (including meeting the respective pressure, temperature and time conditions), the electrode assembly can be produced without separately applying heat and / or pressure at each stage of the electrode assembly to bond the components together (i.e., without heating and / or pressing each electrode to separate them).

[0042] Since already stacked layers each subsequently experience applied heat and / or pressure, separate heating and pressurization at each of these stages can cause the effects of the heat and / or pressure to accumulate detrimentally on lower separators in the stack. This can negatively impact such portions of the separator, for example by reducing porosity (and breathability). In contrast, the present invention can bond the entire electrode assembly simultaneously, improving uniformity above all else. Thus, a separator with the right level of adhesion between the electrodes and the right breathability can be simultaneously achieved while minimizing damage to the unit electrodes.

[0043] In one embodiment of the present invention, the step of stacking the first electrode, the separator, and the second electrode on a stack table to manufacture a stack includes the steps of stacking the separator on the stack table (S1), stacking the first electrode on the upper surface of the separator (S2), supplying the separator while rotating the stack table so as to cover the upper surface of the first electrode (S3), and stacking the second electrode on the portion of the separator covering the upper surface of the first electrode (S4). The steps S1 to S4 may be repeated one or more times. By repeating the above steps one or more times, zigzag folding is possible so that the separator is located between the first electrode and the second electrode.

[0044] In one embodiment of the present invention, the stack including the separation membrane and at least one of the first and second electrodes may be held by the holding mechanism and fixed to the stack table. The holding mechanism may also be called a gripper.

[0045] In one embodiment of the present invention, the method may further include holding the first electrode or the second electrode using the holding mechanism, and fixing the first electrode or the second electrode to the stack table when the first electrode or the second electrode is stacked on the stack table, thereby preventing the position of the electrode from shifting from the electrode assembly.

[0046] In this case, the holding mechanism can press and fix the top surface of the stack (i.e., the top surface or separation film of the first electrode or second electrode stacked at the top of the stack) when stacked on the stack table.

[0047] In an embodiment of the present invention, the step of supplying the separation membrane to the stack table may include continuously supplying (unwinding) the separation membrane while the separation membrane passes through a passage of the separation membrane supply unit.

[0048] In one embodiment of the present invention, the method may further include inspecting a lamination quality of the first electrode or the second electrode using image information acquired by photographing with a camera before laminating the first electrode or the second electrode.

[0049] According to an embodiment of the present invention, there is provided an electrode assembly manufactured by the above-described manufacturing method. The electrode assembly has uniform adhesion and air permeability across all layers of the assembly, and each electrode has a uniform thickness. That is, variations in adhesion, air permeability, and electrode thickness are minimized throughout the electrode assembly.

[0050] According to an embodiment of the present invention, there is provided an apparatus for manufacturing an electrode assembly according to the above-mentioned manufacturing method. As disclosed herein, such an apparatus includes a stack table on which a first electrode, a separation membrane, and a second electrode are stacked; a separation membrane supply unit that supplies a separation membrane to the stack table; a first electrode supply unit that supplies the first electrode; a second electrode supply unit that supplies the second electrode; a first electrode stack unit that stacks the first electrode supplied from the first electrode supply unit on the stack table; a second electrode stack unit that stacks the second electrode supplied from the second electrode supply unit on the stack table; a press unit that heats and pressurizes a stack including the first electrode, the separation membrane, and the second electrode to bond the first electrode, the separation membrane, and the second electrode; and a gripper that grips and fixes the stack when heated and pressed by the press unit, and the press unit heats and pressurizes the stack while the stack is gripped by the gripper to perform a first heat press operation, and the press unit presses the stack for 5 to 60 seconds under temperature conditions of 50°C to 90°C and pressure conditions of 1 MPa to 6 MPa to perform a second heat press operation.

[0051] In one embodiment of the present invention, the press unit may further include a pair of pressurizing blocks and a press heater for heating the pressurizing blocks, and the pair of pressurizing blocks may be configured to move toward each other to heat and pressurize the stacked laminate. The pressurizing blocks and the press heater constituting the press unit may be applied as described above in the method for manufacturing an electrode assembly.

[0052] In one embodiment of the present invention, the first electrode supply unit may include a first electrode placing table on which the first electrode is placed before being stacked on the stack table by the first electrode stack unit, and the second electrode supply unit may include a second electrode placing table on which the second electrode is placed before being stacked on the stack table by the second electrode stack unit.

[0053] In addition, the first electrode stack unit may include a first suction head for vacuum suction to pick up the first electrode placed on the first electrode mounting table, and the second electrode stack unit may include a second suction head for similarly vacuum suction to pick up the second electrode placed on the second electrode mounting table.

[0054] In an embodiment of the present invention, the first electrode supply unit and the second electrode supply unit may include a heater, and the first electrode and the second electrode may be supplied while being heated by the heater, respectively.

[0055] More specifically, in one embodiment of the present invention, the first electrode placement table may include a heater capable of heating the first electrode placement table in order to transfer heat to the first electrode.

[0056] Furthermore, in one embodiment of the present invention, the second electrode placement table may include a heater capable of heating the second electrode placement table in order to transfer heat to the second electrode.

[0057] In one embodiment of the present invention, the first suction head may include a heater, and the heater may be used to heat the first electrode.

[0058] In one embodiment of the present invention, the second suction head may include a heater, and the heater may be used to heat the second electrode.

[0059] In an embodiment of the present invention, the electrode assembly manufacturing apparatus may further include a rotating unit for rotating a stack table, and the first electrode stack unit may be provided on one side of the rotating unit and the second electrode stack unit may be provided on the other side of the rotating unit. Thus, the separator is positioned between the first electrode and the second electrode, thereby enabling zigzag folding, and the rotating unit may rotate the stack table to one side to face the first suction head of the first electrode stack unit when the first electrodes are alternately stacked, and rotate the stack table to the other side to face the second suction head of the second electrode stack unit when the second electrodes are stacked.

[0060] In an embodiment of the present invention, the holding mechanism may apply a certain amount of pressure to fix an upper surface of an electrode or a separator located at the top of the stack stacked on the stack table.

[0061] The method for measuring the adhesive strength of the separator in the present invention is not particularly limited. In the method further used and discussed in this specification, the lower, middle and upper parts of the electrode assembly were separated along the lamination direction of the electrode assembly, and samples were prepared in the width direction of the anode tab part, the middle part and the cathode tab part, respectively. The width of the samples was 55 mm and the length was 20 mm, and each sample may include an anode and a separator or a cathode and a separator. The samples were attached to a glass slide, and the electrodes were located on the adhesive surface of the glass slide.

[0062] More specifically, the slide glass to which the sample was attached was attached was attached to an adhesion measuring device, and the force value (g / mm) per sample width was measured when the separation film was peeled off from the electrode according to the standard test method described in ASTM-D 6862. Specifically, the edge of the separation film was pulled upward at 90° to the slide glass at a speed of 100 mm / min, and the separation film was peeled off from the electrode along the width direction of the sample (i.e., peeled off from 0 mm to 55 mm).

[0063] In the present invention, the method for measuring the air permeability of the separation membrane is not particularly limited. In the method further utilized and discussed in this specification, the air permeability was measured according to the method commonly used in the industry, i.e., the JIS Gurley measurement method of the Japanese Industrial Standards using a Gurley type densitometer (No. 158) manufactured by Toyo Seiki Co., Ltd. That is, the air permeability of the separation membrane was obtained by measuring the time it takes for 100 ml (or 100 cc) of air to pass through 1 square inch of separation membrane under a pressure of 0.05 MPa at room temperature.

[0064] Fig. 2 shows a top view of an example of an apparatus for manufacturing an electrode assembly according to an embodiment of the present invention, and Fig. 3 shows a front elevational view conceptually illustrating an example of an apparatus for manufacturing an electrode assembly according to an embodiment of the present invention. Here, for convenience, the separation membrane supply unit 120 shown in Fig. 3 is omitted in Fig. 2, and the holding mechanism 170 shown in Fig. 2 is omitted in Fig. 3, and the pressing unit 180 located at the rear in the top view is indicated by a dotted line.

[0065] 2 and 3, an apparatus 100 for manufacturing an electrode assembly according to an embodiment of the present invention includes a stack table 110, a separation membrane supply unit 120 for supplying a separation membrane 14, a first electrode supply unit 130 for supplying a first electrode 11, a second electrode supply unit 140 for supplying a second electrode 12, a first electrode stack unit 150 for stacking the first electrode 11 on the stack table 110, a second electrode stack unit 160 for stacking the second electrode 12 on the stack table 110, and a press unit 180 for bonding the first electrode 11, the separation membrane 14, and the second electrode 12 to each other. The press unit 180 can be used in both the first and second heat pressing operations described above. Alternatively, the second heat pressing operation may be performed by another press unit (not shown) that transfers between press units after the first heat pressing operation is completed by the press unit 180.

[0066] In addition, the electrode assembly manufacturing apparatus 100 according to an embodiment of the present invention may further include a holding mechanism 170 that fixes the first electrode 11 and the second electrode 12 to the stack table 110 when the first electrode 11 and the second electrode 12 are stacked on the stack table 110. In addition, the holding mechanism 170 may fix the stack of the first electrode 11, the separator 14, and the second electrode 12.

[0067] Hereinafter, the manufacturing apparatus for an electrode assembly according to one embodiment of the present invention will be described in more detail with reference to FIGS.

[0068] FIG. 4 is a cross-sectional view showing an electrode assembly manufactured by an apparatus for manufacturing an electrode assembly according to an embodiment of the present invention.

[0069] 2 to 4, an apparatus 100 for manufacturing an electrode assembly according to an embodiment of the present invention is an apparatus for manufacturing an electrode assembly 10 by stacking a first electrode 11, a separator 14, and a second electrode 12.

[0070] The electrode assembly 10 is a chargeable and dischargeable power generating element, and may be formed in a form in which a first electrode 11, a separator 14, and a second electrode 12 are alternately stacked and assembled.

[0071] Here, in the electrode assembly 10, for example, the separator 14 may be folded in a zigzag shape, and the first electrodes 11 and the second electrodes 12 may be alternately arranged between the folded separators 14. In this case, the electrode assembly 10 may be provided in a form in which the outermost periphery is surrounded by the separator 14, for example, as shown in FIG 4, or in a form in which the assembled electrode assembly 10 surrounds the separator.

[0072] Fig. 5 shows a perspective view of a press unit in an electrode assembly manufacturing apparatus according to an embodiment of the present invention, and Fig. 6 shows a perspective view of an example of a state in which the press unit presses the laminate in the electrode assembly manufacturing apparatus. More specifically, Fig. 6 shows the above-mentioned second heat press operation.

[0073] 4 to 6, press unit 180 applies pressure to heated and stacked first electrode 11, separator 14, and second electrode 12 to bond first electrode 11, separator 14, and second electrode 12 to one another.

[0074] In addition, the press unit 180 includes a pair of pressure blocks 181 and 182 that move toward each other to affect the compression of the laminate S including the first electrode 11, the separator 14, and the second electrode 12 that are laminated.

[0075] In this case, when the separation membrane 14 surrounds the outer surface of the laminate S, the outer portion of the separation membrane 14 located along the side surface of the laminate S and the space between the folded portion of the separation membrane 14 facing the outer portion and a part of the first and second electrodes 11 and 12 may be joined. This makes it possible to more effectively prevent the first and second electrodes 11 and 12 from being misaligned with the separation membrane 14 and to prevent the components of the stack from being separated from each other.

[0076] In addition, the press unit 180 further includes press heaters 183, 184 for heating the pair of pressurizing blocks 181, 182, and the pair of pressurizing blocks 181, 182 can heat and pressurize the laminate S. This allows for better thermal fusion between the first electrode 11, the separation membrane 14, and the second electrode 12 when the laminate S is pressed by the press unit 180, thereby enabling stronger adhesion.

[0077] The pair of pressure blocks 181, 182 have flat pressure surfaces, and the width and length dimensions of the pressure surfaces may be longer than the opposing width and length dimensions of the laminate S.

[0078] The pair of pressure blocks 181, 182 includes a first pressure block 181 and a second pressure block 182, and the first pressure block 181 and the second pressure block 182 are each defined as a rectangular block having a rectangular hexahedral shape.

[0079] FIG. 7 is a perspective view showing a stack table in an apparatus for manufacturing an electrode assembly according to an embodiment of the present invention.

[0080] Referring to Figures 3 and 7, the stack table 110 may include a table body 111 on which the first electrode 11, the separation membrane 14 and the second electrode 12 are stacked, and a stack table heater 112 that heats the table body 111 and transfers heat to the stack S.

[0081] The first electrode 11 may be an anode and the second electrode 12 may be a cathode, but is not necessarily limited to this. For example, the first electrode 11 may be a cathode and the second electrode 12 may be an anode.

[0082] Referring to FIG. 3, the separation membrane supply unit 120 can supply the separation membrane 14 to the stack table 110 .

[0083] The separation membrane supply unit 120 may have a passage through which the separation membrane 14 passes toward the stack table 110. In particular, the separation membrane supply unit 120 may include a separation membrane heating unit (separation membrane heating unit 121) that defines a passage through which the separation membrane 14 passes toward the stack table 110. As shown in FIG. 14, the separation membrane heating unit 121 includes a pair of bodies 121a, each of which may be configured in a rectangular block shape, and the bodies 121a may be spaced apart by a distance that defines one of the dimensions of the passage through which the separation membrane 14 passes. At least one or both of the bodies 121a may further include a separation membrane heater 121b that transfers heat to the separation membrane 14 by heating the respective bodies 121a.

[0084] The separation membrane supply unit 120 may further include a separation membrane roll 122 on which the separation membrane 14 is wound. Thus, the separation membrane 14 wound on the separation membrane roll 122 can be gradually unwound and fed to the stack table 110 through the formed passage.

[0085] FIG. 8 is a perspective view showing a first electrode mounting table in an electrode assembly manufacturing apparatus according to an embodiment of the present invention.

[0086] 3 and 8, the first electrode supply unit 130 can supply the first electrodes 11 to the first electrode stack unit 150. In addition, the first electrode supply unit 130 may include a first electrode placement table 131 on which the first electrodes 11 are placed before being stacked on the stack table 110 by the first electrode stack unit 150.

[0087] The first electrode supply unit 130 may further include a first electrode roll 133 on which the first electrode 11 is wound in a sheet shape, a first cutter 134 for cutting the sheet-shaped first electrode 11 wound around the first electrode roll 133 at regular intervals to form first electrodes 11 of a predetermined size when the sheet-shaped first electrode 11 is unwound and supplied, a first conveyor belt 135 for moving the first electrode 11 cut by the first cutter 134, and a first electrode supply head 136 for picking up (e.g., vacuum suction) the first electrode 11 transported by the first conveyor belt 135 and placing it on the first electrode placement table 131. Here, the first cutter 134 may cut the sheet-shaped first electrode 11 so that a first electrode tab 11a is formed protruding from an end portion when the sheet-shaped first electrode 11 is cut.

[0088] FIG. 9 is a perspective view showing a second electrode mounting table in an electrode assembly manufacturing apparatus according to an embodiment of the present invention.

[0089] 3 and 9, the second electrode supply unit 140 can supply the second electrode 12 to the second electrode stack unit 160. In addition, the second electrode supply unit 140 may include a second electrode placement table 141 on which the second electrode 12 is placed before being stacked on the stack table 110 by the second electrode stack unit 160.

[0090] The second electrode supply unit 140 may further include a second electrode roll 143 on which the second electrode 12 is wound in a sheet shape, a second cutter 144 for cutting the sheet-shaped second electrode 12 wound around the second electrode roll 143 at regular intervals to form second electrodes 12 of a predetermined size when the sheet-shaped second electrode 12 is unwound and supplied, a second conveyor belt 145 for moving the second electrode 12 cut by the second cutter 144, and a second electrode supply head 146 for picking up (e.g., vacuum suction) the second electrode 12 transported by the second conveyor belt 145 and placing it on the second electrode placement table 141. Here, the second cutter 144 may cut the sheet-shaped second electrode 12 so that a second electrode tab 12a is formed protruding from an end portion when cutting the sheet-shaped second electrode 12.

[0091] FIG. 10 is an oblique view showing a first suction head in an electrode assembly manufacturing apparatus according to one embodiment of the present invention, and FIG. 11 is a bottom view showing the first suction head in an electrode assembly manufacturing apparatus according to one embodiment of the present invention.

[0092] 3, 10 and 11, the first electrode stacking unit 150 may stack the first electrodes 11 on the stack table 110. The first electrode stacking unit 150 may include a first suction head 151 and a first moving unit 153. The first suction head 151 may pick up the first electrode 11 placed on the first electrode placement table 131 through vacuum suction. At this time, the first suction head 151 may have a vacuum suction port 151a formed on a bottom surface 151b thereof, and may suck the first electrode 11 through the vacuum suction port 151a to fix the first electrode 11 to the bottom surface 151b of the first suction head 151. Here, the first suction head 151 may have a passage formed therein connecting the vacuum suction port 151a to a vacuum suction device (not shown).

[0093] The first moving section 153 can move the first suction head 151 to the stack table 110 so that the first suction head 151 can stack the first electrodes 11 on the stack table 110 .

[0094] Meanwhile, referring to FIG. 3, the second electrode stacking unit 160 may stack the second electrode 12 on the stack table 110. Here, the second electrode stacking unit 160 may have the same structure as the above-mentioned first electrode stacking unit 150. In this case, the second electrode stacking unit 160 may include a second suction head 161 and a second moving unit 163. The second suction head 161 may pick up the second electrode 12 placed on the second electrode placement table 141 through vacuum suction. Then, the second moving unit 163 may move the second suction head 161 to the stack table 110 so that the second suction head 161 can stack the second electrode 12 on the stack table 110.

[0095] FIG. 12 is a plan view showing a holding mechanism and a stack table in an apparatus for manufacturing an electrode assembly according to one embodiment of the present invention.

[0096] 2 and 12, when the first electrode 11 or the second electrode 12 is stacked on the stack table 110, the holding mechanism 170 can hold the first electrode 11 or the second electrode 12 and fix the first electrode 11 or the second electrode 12 to the stack table 110. At this time, the holding mechanism 170 can apply pressure to the upper surface of the stack S (i.e., the first electrode 11, the second electrode 12, or the separation membrane 14 stacked on the top layer of the stack S). That is, when the first electrode 11 and the second electrode 12 in the stack S are located between the layers of the separation membrane 14, the holding mechanism 170 can press the stack S toward the stack table 110 to fix the top surface of the stack and prevent the stack S from moving relative to the stack table 110. The holding mechanism 170 may include, for example, a first holder 171 and a second holder 172 for fixing both sides of the first electrode 11 or the second electrode 12. Holders 171, 172 may each be in the form of one or more clamps or other clamping mechanisms.

[0097] When the stack table 110 rotates, with the holding mechanism 170 gripping the first electrode 11 or the second electrode 12, the separation membrane 14 may be unwound from the separation membrane roll 122 and fed to the stack table 110 in proportion to the amount of rotation of the stack table 110. The holding mechanism 170 and the stack table 110 may be connected or coupled to a rotating device (not shown) that affects the rotation of the stack table 110. Such a rotating device may include, for example, a mandrel or other form of rotating or pivot shaft. Thus, when the holding mechanism 170 grips the first electrode 11 or the second electrode 12, the rotating device may rotate the holding mechanism 170 together with the stack table 110.

[0098] Hereinafter, the operation of the electrode assembly manufacturing apparatus 100 according to an embodiment of the present invention will be described.

[0099] 2 to 4, the separation membrane 14 wound around the separation membrane roll 122 is supplied onto the stacking table 110 while passing through a passage formed so that the separation membrane is stacked.

[0100] Furthermore, when the first electrode 11 is supplied from the first electrode supply unit 130 to the first electrode stack unit 150 , the first electrode stack unit 150 stacks the first electrode 11 on the upper surface of the separation membrane 14 stacked on the stack table 110 .

[0101] Thereafter, the holding mechanism 170 applies pressure to the upper surface of the first electrode 11 to secure the position of the first electrode 11 on the stack table 110 .

[0102] Thereafter, when the stack table 110 rotates toward the second electrode stack unit 160, the separation film 14 is continuously supplied so as to cover the upper surface of the first electrode 11.

[0103] Next, the second electrode 12 supplied from the second electrode stack unit 140 is stacked by the second electrode stack unit 160 in a portion covering the upper surface of the separation membrane 14. Thereafter, the holding mechanism 170 releases the grip on the upper surface of the first electrode 11, and then presses the upper surface of the second electrode 12 to secure the position of the stack S to be constructed relative to the stack table 110.

[0104] Thereafter, the process of stacking the first electrode 11 and the second electrode 12 can be repeated to form a stack S in which the separator 14 is folded in a zigzag pattern and positioned between the continuous first and second electrodes 11, 12.

[0105] The laminate S is then moved to the press section 180, which heats and presses the laminate S to heat-seal the components of the stack (i.e., the heated first electrode 11, the separator 14 and the second electrode 12) to produce the electrode assembly 10.

[0106] The laminate S may be moved to the press section by a gripper 51 configured to grip the laminate on the stack table 110 and then move the laminate to the press section 180 where a heat press operation is performed. The press section 180 may be divided into a first press section 50 and a second press section 60, where the first press section 50 may be used for a first heat press operation (or preheating) and the second press section 60 may be used for a second heat press operation.

[0107] 15A and 15B, the first press unit 50 can apply heat and pressure primarily while fixing the laminate S. The first press unit 50 includes a pair of first pressurizing blocks 50a, 50b, and may further include a gripper 51 configured to fix the laminate S. When fixing the laminate S, the gripper 51 can press the upper and lower surfaces of the laminate S along the stacking direction (along the y-axis) to grip the laminate S and fix the relative positions of the first electrode 11, the second electrode 12, and the separator 14. As shown in the example, the gripper 51 can press the upper and lower surfaces of the laminate S to maintain such relative positions.

[0108] The first pressurizing blocks 50a, 50b of the pair of first press units 50 can move toward and away from each other. The pair of first pressurizing blocks 50a, 50b can compress either or both of the laminate S and the gripper 51 while moving toward each other.

[0109] In this manner, the first press section 50 can heat and compress the laminate S to reduce or eliminate the spaces between the first electrode 11 and the separator 14 and second electrode 12 contained in the laminate S, thereby bonding such components of the laminate S.

[0110] As shown, each pressure surface of the pair of first pressure blocks 50a, 50b configured for contacting and compressing the laminate S can be defined as a plane. At least one of the pair of first pressure blocks 50a, 50b may include gripper grooves 52 shaped to correspond to the fixed parts 51b of the gripper 51 described herein. In the example shown in FIG. 15A, the pair of first pressure blocks 50a, 50b each includes four gripper grooves 52, corresponding to the four fixed parts 51b. However, there may be more or fewer gripper grooves 52. Preferably, the number of gripper grooves 52 should match the number of fixed parts used.

[0111] The gripper 51 may include a main body 51a and a plurality of fixing portions 51b. As in the illustrated arrangement, the main body 51a may have a length along the x-axis and a height along the y-axis, each of which may have the same or approximately the same length and height as the length and height of the stack S. In some other arrangements, the main body may have a height that is longer than the length of the stack S in the x-axis and greater than the height of the stack S in the y-axis. The fixing portions 51b may preferably be in the form of a rod, column, or plate extending along the width direction (z-axis) of the stack S. Here, the length of the stack S in the x-axis refers to the longest part from one end of the stack S to the other end, the height in the y-axis refers to the distance in the stacking direction of the stack S, and the width in the z-axis may refer to the distance in the direction perpendicular to both sides of the x-axis and y-axis.

[0112] The fixing portions 51b may be provided in two rows, one row adjacent to the pressing surface of the pressing block 50a and the other row adjacent to the pressing surface of the pressing block 50b. The position of each fixing portion 51b can be adjusted in the height direction of the main body 51a. In this manner, each fixing portion 51b may be arranged to contact the upper and lower surfaces of the stack S, preferably along its width, so as to fix the relative positions of the first electrode 11 and the second electrode 12 in the stack S and the position of the stack S.

[0113] In some arrangements, the second press section 60 may heat and compress the laminate S that has previously been heated and compressed by the first press section 50, to secondarily compress the already primarily compressed laminate S.

[0114] As shown in Fig. 15B, the second press section 60 includes a pair of second pressurizing blocks 60a, 60b. The pair of pressurizing blocks 60a, 60b may be moved toward or away from each other. When moving toward each other, the pair of pressurizing blocks 60a, 60b can apply pressure to the top and bottom surfaces of the laminate S to compress the laminate.

[0115] As shown, each pressure surface of the pair of second pressure blocks 60a, 60b configured for contacting and compressing the laminate S can be defined as a plane. As shown, in some arrangements, the groove for the fixing portion 51b may be omitted from the second pressure blocks 60a, 60b. In some other arrangements, at least one of the pair of second pressure blocks 60a, 60b may include one or more grooves shaped to correspond to the fixing portion 51b of the gripper 51.

[0116] In some arrangements, each of a pair of first pressure blocks 50a, 50b of the first press section 50 includes a gripper groove 52 shaped to correspond to the fixed portion 51b of the gripper 51, and each of a pair of second pressure blocks 60a, 60b of the second press section 60 has a flat press surface without a gripper groove.

[0117] In some arrangements, the second press part 60 may heat and press only the portion of the laminate S where (or before) the grippers are located that is not heated and pressed by the first press part 50. In some other arrangements, the second press part 50 may heat and press the entire top and bottom surfaces of the laminate.

[0118] In some arrangements, the first press section 50 may initially pressurize the heated laminate S with the top and bottom surfaces of the laminate S secured to the grippers 51 in order to reduce or eliminate the space between the first electrode 11, separator 14 and second electrode 2 contained in the laminate S to bond the components of the laminate S together in areas of the laminate S where the grippers 51 are not located.

[0119] In some such configurations, the second press unit 60 can compress and heat the laminate S that has been previously joined by the first press unit 50 and from which the gripper 51 has been removed. This allows the second press unit 60 to reduce or remove spaces between the first electrode 11, the separator 4, and the second electrode 12 included in the laminate S to bond such components of the laminate S together in areas where the gripper 51 previously pressed the laminate S during the initial pressing operation by the first press unit 50. In some such arrangements, the pair of second press blocks 60a, 60b may each be a rectangular hexahedron-shaped square block. In such an arrangement, the pair of second press blocks 60a, 60b may have the flat pressing surface described above.

[0120] In some arrangements, the pair of first press blocks 50a, 50b of the first press section 50 may each have a flat press surface. In such an arrangement, the pair of second press blocks 60a, 60b of the second press section 60 may each have a groove shaped to correspond to the fixing portion 51b of the gripper 51.

[0121] In some arrangements, the fastening portion 51b may comprise a thermally conductive material, such as a thermally conductive metallic material selected from the group consisting of aluminum and iron. By conducting heat to the laminate S, when the first press portion 50 compresses the laminate S fastened by the gripper 51, the electrodes 11, 12 and the separator 4 may be joined together with the space therebetween reduced or eliminated.

[0122] In some arrangements, the second press section 60 may not compress areas of the laminate S where the grippers 51 were previously located, but instead may compress only areas of the laminate S where the grippers 51 were not previously located and were not being pressed during the initial pressurization of the first press section 50.

[0123] Also, the pair of first pressurizing blocks 50a, 50b may each be a rectangular block having a rectangular parallelepiped shape. In such an arrangement, the pair of first pressurizing blocks 50a, 50b may have the flat pressurizing surfaces described above.

[0124] Either or both of the first and second press units 50, 60 preferably include a press heater (not shown) configured to heat the pair of first and second press blocks 50a, 50b, 60a, 60b to heat the laminate S as the blocks press the laminate. In this manner, pressing the laminate S in the first and second press units 50, 60 can better heat-seal the first electrode 11, the separator 14, and the second electrode 12, forming stronger bonds between these layers.

[0125] In any one or more of the pair of first and second pressure blocks 50a, 50b, 60a, 60b, the length and width of each pressure surface may be greater than the corresponding length and width of the laminate S (x and z axes, respectively).

[0126] The electrode assembly manufacturing apparatus 100 according to one embodiment of the present invention configured as described above can preferably prevent the components of the laminate S from collapsing or the components of the laminate S from shifting in position within the laminate S by thermally fusing the components of the laminate S to each other.

[0127] Hereinafter, an apparatus for manufacturing an electrode assembly according to another embodiment of the present invention will be described.

[0128] 13 is a front view conceptually illustrating an electrode assembly manufacturing apparatus according to another embodiment of the present invention, in which a holding mechanism is omitted for convenience, and a pressing unit 180 located at the rear in the plan view is indicated by a dotted line.

[0129] Referring to FIG. 13, an electrode assembly manufacturing apparatus 200 according to another embodiment of the present invention includes a stack table 110; a separation membrane supply unit 120 that supplies a separation membrane 14; a first electrode supply unit 130 that supplies a first electrode 11; a second electrode supply unit 140 that supplies a second electrode 12; a first electrode stack unit 150 that stacks the first electrode 11 on the stack table 110; a second electrode stack unit 160 that stacks the second electrode 12 on the stack table 110; a press unit 180 that joins the first electrode 11, the separation membrane 14 and the second electrode 12 to each other; and a holding mechanism 170 for fixing the position of the stack S on the stack table 110 (see FIG. 12).

[0130] The apparatus 200 according to another embodiment of the present invention may further include a rotating unit R for rotating the stack table 110 and a vision device 290 for inspecting the first and second electrodes 11,12.

[0131] Therefore, in this embodiment, the contents that overlap with the previous embodiment will be briefly described, and the description will focus on the differences from the previous embodiment.

[0132] More specifically, the vision device 290 of the device 200 may include a first camera 291 and a second camera 292. The first camera 291 can photograph the first electrode 11 placed on the first electrode placement table 131 in the first electrode supply unit 130, and the second camera 292 can photograph the second electrode 12 placed on the second electrode placement table 141 in the second electrode supply unit 140. Through the image information obtained by the first camera 291 and the second camera 292, the stacking quality of the first electrode 11 and the second electrode 12 can be inspected. For example, the placement position, size, and stacking state of the first electrode 11 and the second electrode 12 can be inspected.

[0133] The rotating unit R can rotate the stack table 110 in one direction r1 and the other direction r2. A first electrode stack unit 150 may be provided on one side of the rotating unit R, and a second electrode stack unit 160 may be provided on the other side of the rotating unit R. The rotating unit R can rotate the stack table 110 to one side to face the first suction head 151 when the first electrode 11 is stacked, and rotate the stack table 110 to the other side to face the second suction head 161 when the second electrode 12 is stacked. By alternately rotating the stack table 110 between the direction facing the first electrode stack unit 150 and the direction facing the second electrode stack unit 160, as shown in FIG. 4, the zigzag folding of the separation membrane 14 between each successive electrode of the first electrode 11 and the second electrode 12 can be achieved.

[0134] The apparatus 200 of this embodiment and all of its subcomponents operate similarly to the apparatus 100 of the previous embodiment, unless otherwise noted. For example, when the first electrode 11 is supplied and placed on the first electrode placement table 131 of the first electrode supply unit 130, the lamination quality of the first electrode 11 can be inspected via the vision device 290. Similarly, when the second electrode 12 is supplied and placed on the second electrode placement table 141 of the second electrode supply unit 140, the lamination quality of the second electrode 12 can be inspected via the vision device 290.

[0135] In one embodiment of the present invention, the anode is prepared by, for example, coating a mixture of a cathode active material, a conductive material, and a binder on an anode current collector and then drying the mixture, and a filler may be further added to the mixture, if necessary. Materials commonly used in the art may be used as the materials used in this case.

[0136] Specifically, the positive electrode active material is, for example, a layered compound such as lithium cobalt oxide (LiCoO2), lithium nickel oxide (LiNiO2), or a compound substituted with one or more transition metals; 1+x Mn 2-xLithium manganese oxides such as LiMnO3, LiMn2O3, and LiMnO2; lithium copper oxide (Li2CuO2); vanadium oxides such as LiV3O8, LiFe3O4, V2O5, and Cu2V2O7; and the chemical formula LiNi1- x M x Lithium nickel oxide with Ni site represented by the chemical formula LiMnO2 (where M=Co, Mn, Al, Cu, Fe, Mg, B or Ga, and x=0.01 to 0.3); 2-x M x Examples of such compounds include, but are not limited to, lithium manganese composite oxides represented by Li2Mn3MO8 (where M is Co, Ni, Fe, Cr, Zn, or Ta, and x is 0.01 to 0.1) or Li2Mn3MO8 (where M is Fe, Co, Ni, Cu, or Zn); LiMn2O4 in which part of the Li in the chemical formula is replaced with an alkaline earth metal ion; disulfide compounds; and Fe2(MoO4)3.

[0137] Specifically, the anode current collector is not particularly limited as long as it has high conductivity without inducing chemical changes in the battery, and may be, for example, stainless steel, aluminum, nickel, titanium, baked carbon, or aluminum or stainless steel surface-treated with carbon, nickel, titanium, silver, etc., but may be aluminum in particular. The current collector may have fine irregularities on its surface to increase the adhesive strength of the anode active material, and may be in various forms such as a film, sheet, foil, net, porous body, foam, nonwoven fabric, etc. In addition, the anode current collector may generally have a thickness of 3 μm to 500 μm.

[0138] The conductive material can be added in an amount of 1 to 50% by weight based on the total weight of the mixture containing the positive electrode active material. Such a conductive material is not particularly limited as long as it has conductivity without inducing chemical changes in the battery, and examples thereof include graphite such as natural graphite and artificial graphite; carbon black such as carbon black, acetylene black, ketjen black, channel black, furnace black, lamp black, and summer black; conductive fibers such as carbon fiber and metal fiber; metal powders such as carbon fluoride, aluminum, and nickel powder; conductive whiskey such as zinc oxide and potassium titanate; conductive metal oxides such as titanium oxide; and conductive materials such as polyphenylene derivatives.

[0139] The binder is a component that aids in binding the active material and conductive material and binding to the current collector, and is usually added in an amount of 1 to 50% by weight based on the total weight of the mixture including the positive electrode active material. Examples of such binders include polyvinylidene fluoride, polyvinyl alcohol, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene-butylene rubber, fluororubber, various copolymers, and the like.

[0140] The filler is selectively used as a component that suppresses the expansion of the anode, and is not particularly limited as long as it does not cause chemical changes in the battery and is a fibrous material. For example, olefin polymers such as polyethylene and polypropylene; glass fiber, carbon fiber, and other fibrous substances are used.

[0141] Also, in one embodiment of the present invention, the cathode is manufactured by applying, drying, and pressing the cathode active material onto a cathode current collector, and optionally further contains a conductive material, a binder, a filler, etc. similar to the above. In this case as well, substances commonly used in the art may be used. Specifically, the cathode active material is, for example, carbon such as graphitizable carbon and graphite-based carbon; Li x Fe2O3(0≦x≦1), Li x WO2(0≦x≦1), Sn x Me 1-x Me' y O z (Me: Mn, Fe, Pb, Ge; Me': Al, B, P, Si, Group 1, Group 2, Group 3 elements of the periodic table, halogen; 0<x≦1; 1≦y≦3; 1≦z≦8), etc. metal composite oxides; lithium metal; lithium alloy; silicon-based alloy; tin-based alloy; metal oxides such as SnO, SnO2, PbO, PbO2, Pb2O3, Pb3O4, Sb2O3, Sb2O4, Sb2O5, GeO, GeO2, Bi2O3, Bi2O4, and Bi2O5; conductive polymers such as polyacetylene; Li-Co-Ni-based materials, etc. can be used.

[0142] Such a cathode current collector is not particularly limited as long as it does not induce a chemical change in the battery and has conductivity. For example, copper, stainless steel, aluminum, nickel, titanium, fired carbon, those surface-treated with carbon, nickel, titanium, silver, etc. on the surface of copper or stainless steel, aluminum-cadmium alloy, etc. can be used. Also, similar to the anode current collector, fine irregularities can be formed on the surface to strengthen the binding force of the cathode active material, and it may be used in various forms such as a film, a sheet, a foil, a net, a porous body, a foam, a non-woven fabric body, etc. Further, the cathode current collector may generally have a thickness of 3 μm to 500 μm.

[0143] In one embodiment of the present invention, the separator may be an organic / inorganic composite porous safety-reinforcing separator (SRS) separator. The SRS separator may have a structure in which a coating layer component including inorganic particles and a binder polymer is coated on a polyolefin-based separator substrate.

[0144] The SRS separator does not undergo high-temperature thermal shrinkage due to the heat resistance of the inorganic particles, so that the elongation rate of the safety separator can be maintained even if the electrode assembly is pierced by the needle-shaped conductor.

[0145] Such an SRS separator may have a uniform pore structure formed by the interstitial volume between inorganic particles, which are a component of the coating layer, as well as the pore structure contained in the separator substrate itself. The pores can significantly reduce external impacts applied to the electrode assembly, and lithium ions can move smoothly through the pores, allowing a large amount of electrolyte to be filled, resulting in a high impregnation rate, thereby improving battery performance.

[0146] In some arrangements, the separator may have a width dimension (perpendicular to the longitudinal dimension along which the separator extends) such that portions of the separator extend outward from both sides beyond the corresponding edges (hereinafter "excess portions") of the adjacent anode and cathode. In addition, such outwardly extending portions of the separator may have a structure including a coating layer formed on one or both sides of the separator that is thicker than the thickness of the separator to prevent the separator from shrinking. For details of the thick coating layer of the excess portions extending outward from the separator, reference may be made to Korean Patent Publication No. 10-2016-0054219, the entire contents of which are incorporated herein by reference. In some arrangements, each excess portion of the separator may have a size of 5% to 12% of the width of the separator. In addition, in some arrangements, the coating layer may be coated on both sides of the separator over a width of 50% to 90% of the width of each excess portion of the separator. In addition, the width of the coating layer may be the same or different on each side of the separator. In some arrangements, the coating layer may include as components inorganic particles and binder polymers.

[0147] In one embodiment of the present invention, examples of the polyolefin-based separator component include high density polyethylene, linear low density polyethylene, low density polyethylene, ultra-high molecular weight polyethylene, polypropylene, or derivatives thereof.

[0148] In one embodiment of the present invention, the thickness of the coating layer may be smaller than the thickness of the first electrode or the second electrode. In a specific example, the thickness of the coating layer may be 30% to 99% of the thickness of the first electrode or the second electrode.

[0149] In one embodiment of the present invention, the coating layer may be formed by wet coating or dry coating.

[0150] In one embodiment of the present invention, the substrate and the coating layer are present in a form in which the pores on the surface of the polyolefin-based separator substrate and the coating layer are intertwined with each other (anchoring), so that the separator substrate and the active layer can be physically firmly bound to each other.

[0151] In this case, the substrate and the active layer may have a thickness ratio of 9:1 to 1:9, particularly 5:5, taking into consideration the physical binding force and the structure of the pores present on the separator.

[0152] In one embodiment of the present invention, the inorganic particles may be inorganic particles commonly used in the art. The inorganic particles allow for the formation of voids between the inorganic particles, and serve as a kind of spacer that can form micropores and maintain a physical shape. In addition, the inorganic particles generally have physical properties that do not change even at high temperatures of 200°C or higher, so that the organic / inorganic composite porous film formed has excellent heat resistance.

[0153] In addition, the inorganic particles are not particularly limited as long as they are electrochemically stable. That is, the inorganic particles that can be used in the present invention are not particularly limited as long as they do not undergo oxidation and / or reduction reactions in the operating voltage range of the applied battery (for example, 0 to 5 V based on Li / Li+). In particular, when inorganic particles having ion transfer ability are used, it is preferable that the ion conductivity is as high as possible because the ion conductivity in the electrochemical element can be increased to improve performance. In addition, when the inorganic particles have a high density, it is not only difficult to disperse them during coating, but also there is a problem of an increase in weight during battery production, so it is preferable that the density is as small as possible. In addition, in the case of an inorganic material with a high dielectric constant, it contributes to an increase in the degree of dissociation of the electrolyte salt, for example, lithium salt, in the liquid electrolyte, and can improve the ion conductivity of the electrolyte solution.

[0154] For the above reasons, the inorganic particles may be at least one type selected from the group consisting of inorganic particles having piezoelectricity and inorganic particles having lithium ion transport ability.

[0155] The piezoelectric inorganic particles are non-conductors under normal pressure, but when a certain pressure is applied, they have the physical property of conducting electricity due to a change in their internal structure. They not only exhibit high dielectric constant characteristics with a dielectric constant of 100 or more, but also have the function of generating charges when stretched or compressed by applying a certain pressure, causing one side to become positively charged and the other side to become negatively charged, generating a potential difference between both sides.

[0156] When inorganic particles having the above-mentioned characteristics are used as a coating layer component, in the event of an internal short circuit between the two electrodes due to an external impact such as a needle-shaped conductor, not only will the inorganic particles coated on the separator prevent direct contact between the anode and cathode, but the piezoelectricity of the inorganic particles will generate a potential difference within the particles, which will result in electron transfer between the two electrodes, i.e., a minute current flow, resulting in a gradual decrease in the battery voltage and thus improved safety.

[0157] Examples of the inorganic particles having piezoelectricity include BaTiO3, Pb(Zr,Ti)O3 (PZT), Pb 1-x La x Zr 1-y Ti y O3(PLZT), PB(Mg3Nb 2 / 3 )O3-PbTiO3 (PMN-PT) and hafnia (HfO2), but is not limited thereto.

[0158] The inorganic particles having the lithium ion transfer ability contain lithium element, but do not store lithium, and refer to inorganic particles having the function of moving lithium ions. The inorganic particles having the lithium ion transfer ability can transfer and move lithium ions due to a kind of defect existing inside the particle structure, so the lithium ion conductivity in the battery is improved, and thereby the battery performance can be improved.

[0159] Examples of the inorganic particles having the lithium ion transfer ability include lithium phosphate (Li3PO4), lithium titanium phosphate (Li x Ti y (PO4)3, 0 < x < 2, 0 < y < 3), lithium aluminum titanium phosphate (Li x Al y Ti z (PO4)3, 0 < x < 2, 0 < y < 1, 0 < z < 3), (LiAlTiP) x O y series glass (0 < x < 4, 0 < y < 13), lithium lanthanum titanate (Li x La y TiO3, 0 < x < 2, 0 < y < 3), lithium germanium thiophosphate (Li x Ge y P z S w , 0 < x < 4, 0 < y < 1, 0 < z < 1, 0 < w < 5), lithium nitride (Li x N y , 0 < x < 4, 0 < y < 2), SiS2 (Li x Si y S z , 0 < x < 3, 0 < y < 2, 0 < z < 4) series glass and P2S5 (Li x P y S z , 0 < x < 3, 0 < y < 3, 0 < z < 7) series glass, and may be one or more selected from the group consisting of, but not limited thereto.

[0160] The composition ratio of the inorganic particles and the binder polymer, which are the components of the coating layer, is not limited, but can be adjusted within a range of 10:90 to 99:1 wt%, and preferably within a range of 80:20 to 99:1 wt%. If the ratio is less than 10:90 wt%, the polymer content becomes too high, and the pore size and porosity decrease due to the reduction in the vacant space formed between the inorganic particles, resulting in a deterioration of the final battery performance. Conversely, if the ratio exceeds 99:1 wt%, the polymer content is too low, and the adhesive strength between the inorganic particles becomes weak, which may result in a deterioration of the mechanical properties of the final organic / inorganic composite porous separator.

[0161] In an embodiment of the present invention, the binder polymer may be a binder polymer commonly used in the art.

[0162] In the organic / inorganic composite porous separator, the coating layer may further contain other commonly known additives in addition to the inorganic particles and binder polymer described above.

[0163] In one embodiment of the present invention, the coating layer may also be referred to as an active layer.

[0164] Although the present invention has been described in detail above through specific embodiments, this is for the purpose of specifically explaining the present invention, and the manufacturing apparatus of the electrode assembly according to the present invention is not limited thereto. It can be said that various implementations are possible by a person having ordinary skill in the art within the technical concept of the present invention.

[0165] 1) Example 1 Nineteen anode sheets, 20 cathode sheets and a long separation membrane were supplied to the stack table from the anode supply section, cathode supply section and separation membrane supply section, respectively.

[0166] More specifically, the anode and cathode were supplied in the form of cuts from an anode sheet and a cathode sheet, respectively, and the long separator was supplied in the form of a separator sheet. Then, as described above, the stack table was rotated to stack the anode and cathode, and the supplied separator was folded. At this time, a holding mechanism was used to press and stabilize the stack on the stack table, producing a stack including 39 electrodes.

[0167] After preparing the laminate, the laminate was gripped with a gripper and pressed for 15 seconds under heating conditions of a temperature of 70° C. and a pressure of 1.91 MPa to perform a first heat press step.

[0168] After the first heat pressing step, the stack table was heated to a temperature of 70° C. as shown in Table 1 below, and a pressure of 2.71 MPa (pressure condition) was applied to the laminate by the press block of the press for 10 seconds (press time), thereby preparing the electrode assembly of Example 1.

[0169] In the process of manufacturing the electrode assembly, the above-mentioned contents regarding the present invention can be applied.

[0170] 2) Examples 2 to 12 The electrode assemblies of Examples 2 to 12 were manufactured in the same manner as in Example 1, except that the second heat pressing step was carried out under the temperature conditions, pressure conditions, and pressing time shown in the following Table 1. That is, the first heat pressing conditions of Examples 1 to 12 were the same.

[0171] [Table 1]

[0172] 3) Comparative Examples 1 to 7 The electrode assemblies of Comparative Examples 1 to 7 were manufactured in the same manner as in Example 1, except that the temperature conditions, pressure conditions, and pressing time of the first heat pressing step in Example 1 were as shown in Table 2 below, and the second heat pressing step was not performed.

[0173] [Table 2]

[0174] An experiment was conducted in which the electrode assemblies of Examples 1 to 12 and Comparative Examples 1 to 5 manufactured under the conditions of Tables 1 and 2 were picked up by a suction mechanism under the same conditions as the electrode supply unit according to the present invention, and the vacuum suction mechanism was maintained for 60 seconds. It was observed that the electrode and the separator were separated from each other before 60 seconds in the electrode assemblies of Comparative Examples 1 to 5. This is because the electrode and the separator were not well bonded in the electrode assemblies of Comparative Examples 1 to 5, whereas the electrode assemblies according to the present application (which underwent the first and second pressing) had a good bonded state, and there was an excellent effect in preventing the electrode assembly from loosening and falling off.

[0175] In the case of Comparative Examples 6 and 7, the phenomenon of the electrode and separator separating before 60 seconds was not observed, but damage was observed in the manufactured electrode assembly, which is believed to be due to the fact that the first pressing was performed under a pressure condition of 2.54 MPa (i.e., high pressure).

[0176] 4) Experimental Example 1 - Adhesion Strength Evaluation The electrode assemblies of Examples 1 to 12 and Comparative Examples 6 and 7 (the phenomenon of the electrode and separator separating before 60 seconds was not observed in previous tests) were disassembled (i.e., layer separation), and the separated layers were analyzed to measure the adhesive strength between the upper, lower, and middle surfaces of the laminate S. Specifically, the adhesive strength between the separator located at the bottom of the laminate and the cathode was measured. In addition, the adhesive strength between the cathode located at the top of the laminate and the separator was measured. Finally, the adhesive strength between the cathode located at the middle position along the stacking direction of the laminate and the separator was measured.

[0177] The width and length of the sampled cathode and separator for each of the separated electrode assemblies were 55 mm and 20 mm. The sampled sample was attached to a glass slide so that the electrode was located on the adhesive surface of the glass slide. The glass slide to which the sample was attached was then placed on the adhesion measuring device, and a 90° peel test was performed at a speed of 100 mm / min according to the test method specified in ASTM-D6862 as described above. After discounting the initial significant fluctuation, the force (g / mm) applied per sample width while the separator was peeled from the electrode was measured. The separator was pulled in a direction perpendicular to the plane on which the glass slide was placed, and the value when the separator was peeled from the electrode was measured.

[0178] The results are shown in Table 3 below.

[0179] [Table 3]

[0180] In the case of Comparative Examples 6 and 7, as described above, the pressure was 2.54 MPa, and therefore it was confirmed that damage occurred to the electrode assembly. Furthermore, as shown in the results of Table 3, the deviation in adhesive strength was significantly large, exceeding 15 gf / 20 mm. This means that the performance of the electrode assembly may not be uniform depending on the position.

[0181] On the other hand, in the cases of Examples 1 to 12, it was confirmed that the deviation in adhesive strength was not large, less than 15 gf / 20 mm, that is, it was confirmed that the electrode assemblies of Examples 1 to 12 had uniform performance.

[0182] 5) Experimental Example 2 - Air permeability evaluation Among Examples 1 to 12, the electrode assemblies of Examples 1, 6 and 12, which differ only in the temperature condition of the second press, were evaluated for air permeability.

[0183] Specifically, the separation membrane was collected from the electrode assemblies of Examples 1, 6, and 12, and then cut into separation membrane samples measuring 5 cm x 5 cm (width x length), and then the separation membrane samples were washed with acetone.

[0184] Thereafter, the air permeability of Examples 1, 6 and 12 was measured by measuring the time it took for 100 ml (or 100 cc) of air to pass through 1 square inch of the separation membrane at room temperature and a pressure of 0.05 MPa using a Toyoseiki Gurley type Densometer (No. 158) according to the Japanese Industrial Standard Gurley measurement method.

[0185] The results are shown in Table 4.

[0186] [Table 4]

[0187] From the results in Table 4, it was confirmed that when the second heat pressing conditions according to the present invention were met, the electrode assembly had a suitable level of air permeability for use as an electrode assembly, and the air permeability at each position was less than 120 sec / 100 ml. The deviation in air permeability at each position was also less than 20 sec / 100 ml, and was determined to be substantially uniform. In other words, it was again confirmed that the electrode assembly manufactured by the manufacturing method according to the present invention has uniform performance.

[0188] It was confirmed that Example 1 under the temperature condition of 70° C. had the smallest air permeability deviation.

[0189] Through the above experimental examples, it was confirmed that the electrode assembly according to the present invention has appropriate and uniform air permeability and adhesive strength. [Explanation of symbols]

[0190] 10...electrode assembly 11...1st electrode 11a First electrode tab 12...Second electrode 12a Second electrode tab 14...Separation membrane 50 ···First Press Department 50a, 50b: First pressure block 51 Gripper 51a Main unit 51b...Fixed part 52 Gripper groove 60 ···Second Press Department 60a, 60b Second pressurizing block 100, 200 Manufacturing apparatus for electrode assembly 110 Stack Table 111 Table body 112 Stack table heater 120...Separation membrane supply section 121 Separation membrane heating section 121a: Torso 121b Separation membrane heater 122 Separation membrane roll 130...First electrode supply section 131 First electrode placement table 133 First electrode roll 134 First cutter 135 No. 1 Conveyor Belt 136 First electrode supply head 140...Second electrode supply section 141 Second electrode placement table 143 Second electrode roll 144 No. 2 cutter 145 - Second conveyor belt 146 Second electrode supply head 150 First electrode stack section 151 1st suction head 151a Vacuum inlet 151b...Bottom surface 153 First moving part 160 Second electrode stack section 161 Second suction head 163 Second moving part 170 ···Holding mechanism 171 First holder 172 2nd Holder 180 ···Press Department 181, 182: Pressure block 183,184 ···Press heater 290 Vision Device 291 ···Camera 1 292 ···Second Camera R Rotating part S ···Laminate

Claims

1. assembling an electrode stack including a plurality of electrodes stacked along a stacking axis and individual separator membrane portions positioned between each of the electrodes; performing a first heat press operation on the electrode stack after assembling the electrode stack, the first heat press operation including: combining the electrode stack with a gripper to fix a position of the electrode stack; and applying heat and pressure to the electrode stack in a state where the gripper is combined with the electrode stack; performing a second heat press operation on the electrode stack after the first heat press operation, the second heat press operation including: separating the gripper from the electrode stack, and then heating and pressing the electrode stack; The second heat pressing operation includes pressing the electrode laminate under a temperature condition of 50° C. to 90° C. and a pressure condition of 1 MPa to 6 MPa for 5 seconds to 60 seconds.

2. 2. The method of claim 1, wherein the separator portion is a portion of a long separator sheet, and the step of assembling the electrode stack includes stacking first and second electrodes of the electrodes alternately on the long separator sheet, and the long separator sheet is folded sequentially onto the first and second electrodes that have been previously stacked before a subsequent electrode of the first and second electrodes is stacked.

3. The step of assembling the electrode stack comprises: (1) placing the long separation membrane sheet on a stack table; (2) laminating one of the first electrodes on an upper surface of the long separator sheet; (3) rotating the stack table while covering an upper surface of one of the first electrodes with the long separator sheet; and (4) laminating one of the second electrodes on an extended portion of a separator sheet covering an upper surface of one of the first electrodes; The method for manufacturing an electrode assembly according to claim 2, wherein steps (1) to (4) are repeated one or more times.

4. The method for manufacturing an electrode assembly according to claim 3 , wherein the electrode stack is fixed to the stack table by a holding mechanism.

5. The method of claim 2 , further comprising inspecting a stacking state of the first electrode and the second electrode using a camera.

6. The method of claim 1 , wherein the first heat pressing operation and the second heat pressing operation both include advancing a pressure block along the lamination axis to engage the electrode laminate.

7. The method for manufacturing an electrode assembly according to claim 6 , further comprising the step of heating the pressurizing block to transfer heat to the electrode stack.

8. 2. The method of claim 1, wherein the first heat pressing operation comprises heating and pressing the electrode laminate under a temperature condition of 65° C. to 90° C. and a pressure condition of 1 MPa to 3 MPa for 10 seconds to 30 seconds.

9. The method of claim 1 , wherein the step of assembling the electrode stack comprises winding a long separator sheet around an outer periphery of the electrode stack.

10. The method of claim 1 , further comprising the step of heating at least one of the electrodes and the separator before assembling the electrode stack.

11. An apparatus for manufacturing an electrode assembly including an electrode stack having a plurality of first electrodes and second electrodes stacked along a stacking axis and each electrode having a separate separator portion located between the electrodes, comprising: a press unit that applies heat and pressure to the electrode stack to bond the electrodes and the separator unit in the electrode stack; and a gripper for engaging with the electrode stack to secure a position of the electrode stack when the heat and pressure are applied to the electrode stack by the press unit, An apparatus for manufacturing an electrode assembly, wherein the press section is configured to apply heat and pressure to the electrode stack while the gripper is engaged with the electrode stack and while the gripper is separated from the electrode stack.

12. a stack table for supporting the electrode stack; a separation membrane supply unit that supplies the separation membrane unit to the stack table; a first electrode supplying unit that supplies the first electrode to the stack table; a second electrode supplying unit that supplies the second electrode to the stack table; a first electrode stack unit that moves the first electrode supplied from the first electrode supply unit to the stack table; The apparatus for manufacturing an electrode assembly according to claim 11, further comprising: a second electrode stacking unit that moves the second electrode supplied from the second electrode supplying unit to the stack table.

13. the first electrode supply unit includes a first electrode placement table on which the first electrodes are placed before being stacked on the stack table by the first electrode stack unit, The apparatus for manufacturing an electrode assembly according to claim 12 , wherein the second electrode supply unit includes a second electrode placement table on which the second electrodes are placed before being stacked on the stack table by the second electrode stack unit.

14. the first electrode stack unit includes a first suction head that picks up the first electrode by vacuum suction; The apparatus for manufacturing an electrode assembly according to claim 12 , wherein the second electrode stack unit includes a second suction head for picking up the second electrode by vacuum suction.

15. 13. The electrode assembly manufacturing apparatus of claim 12, further comprising a rotating unit for rotating the stack table between a first position and a second position, the first position facing the first electrode stack unit to receive the first electrode from the first electrode stack unit, and the second position facing the second electrode stack unit to receive the second electrode from the second electrode stack unit.

16. The electrode assembly manufacturing apparatus according to claim 11 , wherein the gripper is a device that applies downward pressure to an upper surface of the electrode stack along the stacking axis to fix the position of the electrode stack relative to the press section.

17. The press unit further includes a press block and a press heater for heating the press block. The electrode assembly manufacturing apparatus of claim 11 , wherein the pressure block is configured to advance along the lamination axis of the electrode stack to apply heat and pressure to the electrode stack.

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