Electrode assembly manufacturing method and electrode assembly manufacturing device

Abstract

To provide an electrode assembly and a method for manufacturing the electrode assembly that prevents cell damage and deformation of mechanical parts.SOLUTION: An electrode assembly includes a plurality of electrodes arranged along the stacking axis of a laminate, with each separation membrane portion located between each electrode in the laminate, the plurality of electrodes include an upper electrode located at the top of the laminate along the stacking axis, an intermediate electrode located in the middle of the laminate along the stacking axis, and a lower electrode located at the bottom of the laminate along the stacking axis, and the separation membrane portion includes an upper separation membrane portion in contact with the upper electrode, an intermediate separation membrane portion in contact with the intermediate electrode, and a lower separation membrane portion in contact with the lower electrode, and the air permeability value per square inch of the intermediate separation membrane portion at a pressure of 0.05 MPa and room temperature deviates by less than 20 sec / 100 ml from the air permeability value per square inch of each of the upper separation membrane portion and the lower separation membrane portion at a pressure of 0.05 MPa and room temperature.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] This application claims the priority of Korean Patent Application Nos. 10-2021-0090596, filed on July 9, 2021, 10-2021-0090592, filed on July 9, 2021, 10-2021-0090597, filed on July 9, 2021, and 10-2021-0090598, filed on July 9, 2021, and all of its content is incorporated herein by reference.

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

Background Art

[0003] Unlike primary batteries, secondary batteries can be recharged and have been actively studied in recent years due to their potential for miniaturization and high capacity. As the technology development and demand for mobile devices increase, the demand for secondary batteries as an energy source has been rapidly increasing.

[0004] Secondary batteries can be classified into coin-type batteries, cylindrical batteries, prismatic batteries, and pouch-type batteries according to the shape of the battery case. An electrode assembly mounted inside the battery case in a secondary battery is a power generation element capable of charge and discharge, which has a laminated structure of electrodes and a separator.

[0005] The electrode assembly can generally be classified into a jelly-roll type, a stack type, and a stack-and-folding type. In the jelly-roll type, the overall arrangement is wound with a separator interposed between a sheet-shaped anode and a cathode, each coated with an active material. In the stack type, a number of anodes and cathodes are sequentially laminated with a separator interposed therebetween. In the stack-and-folding type, the laminated unit cells are wound with a long separation film.

[0006] The stacked and folded electrode assembly had a problem that the position of the electrode was distorted in a form where the separation membrane was folded in a zigzag pattern and the electrode was positioned therebetween.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0008] First, the present invention provides a method and an apparatus for manufacturing an electrode assembly that prevent cell damage and deformation of mechanical parts in the manufacturing process of an electrode assembly produced by laminating an electrode and a separation membrane.

[0009] Also, the present invention provides an apparatus for manufacturing an electrode assembly that can prevent the electrode from being distorted during the manufacturing process.

Means for Solving the Problems

[0010] One embodiment of the present invention provides a method for manufacturing an electrode assembly. The method according to one embodiment of the present invention preferably includes, after assembling an electrode laminate, performing a first heat press operation on the electrode laminate, and then performing a second heat press operation on the electrode laminate. In the step of assembling the electrode laminate, it is preferable to include a plurality of electrodes laminated along a lamination axis and individual separation film portions located between each electrode. In the first heat press operation, the electrode laminate may be coupled to a gripper to secure the position of the electrode stack. Then, while the gripper is coupled to the electrode laminate, heat and pressure may be applied to the electrode laminate as part of the first heat press operation. In the second heat press operation, after the gripper is separated from the electrode laminate, heat and pressure may be applied to the electrode laminate as part of the second heat press operation. Further, the second heat press operation preferably includes applying heat and pressure to the electrode laminate for 5 seconds to 60 seconds under temperature conditions of 50°C to 90°C and pressure conditions of 1 Mpa to 6 Mpa.

[0011] According to one embodiment of the present invention, the separation film portion may be a part of an elongated separation film sheet. In such an aspect of the present invention, the step of assembling the electrode laminate may include alternately laminating a first electrode among the electrodes and a second electrode among the electrodes on the elongated separation film sheet. Further, the elongated separation film sheet may be sequentially folded onto one of the first electrode and the second electrode that have been previously laminated before one of the subsequent electrodes among the first electrode and the second electrode is laminated.

[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 laminate in which a plurality of first electrodes and second electrodes laminated along a stacking axis have individual separator portions positioned between the respective electrodes and laminated along the stacking axis. The apparatus according to an embodiment of the present invention preferably includes a pressing unit and a gripper. The pressing unit applies heat and pressure to the electrode laminate to bond the electrodes and the separator portions in the electrode laminate. The gripper engages with the electrode laminate to fix the position of the electrode laminate when heat and pressure are applied to the electrode laminate by the pressing unit. Preferably, the gripper and the pressing unit are configured to be able to apply heat and pressure while the gripper is engaged with the electrode laminate and while the gripper is separated from the electrode laminate.

[0013] According to an embodiment of the present invention, the apparatus may further include a stack table for supporting the electrode laminate; a separator supply unit for supplying a separator to the stack table; a first electrode supply unit for supplying the first electrode to the stack table; a second electrode supply unit for supplying the second electrode; a first electrode stacking unit for moving the first electrode supplied from the first electrode supply unit to the stack table; and a second electrode stacking unit for moving the second electrode supplied from the second electrode supply unit to the stack table.

[0014] According to another embodiment of the present 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 stacking unit to receive the first electrode from the first electrode stacking unit, and the second position may be toward the second electrode stacking unit to receive the second electrode from the second electrode stacking unit.

Advantages of the Invention

[0015] According to the present invention, by heating and pressing the entire stack in the pressing section, it is possible to bond the electrodes to the separator without the need to individually heat and / or press (i.e., heat and / or press each electrode-separator pair at each stage of the process) at each stage of the electrode assembly that heats and laminates the electrodes and the separator. As a result, it is possible to prevent harmful accumulation of heat and / or pressure in the lower separator 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 such as the adhesive force between the electrode and the separator, the air permeability of the separator, and the thickness of the manufactured electrode assembly, and can increase the uniformity.

[0017] By pressing the entire stack laminated in the pressing section, the present invention also preferably reduces the distortion or movement of the position of the electrodes in the electrode laminate. Advantageously, it is possible to shorten the manufacturing time as well as improve the energy density of the manufactured electrode assembly.

Brief Description of the Drawings

[0018]

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Embodiments for Carrying Out the Invention

[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. It should be noted that when adding reference numerals to the components of each drawing in this specification, the same components are given the same numbers even if they are shown 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 describing the present invention, detailed descriptions of related known technologies that may unnecessarily obscure the gist of the present invention are omitted.

[0020] According to an embodiment of the present invention, a method for manufacturing an electrode assembly can be provided. The method includes the steps of supplying a first electrode to a stack table; supplying a second electrode to the stack table; supplying a separation membrane to the stack table; and alternately laminating the first electrode and the second electrode on the separation membrane to assemble a laminate on the stack table, wherein the separation membrane may be sequentially folded onto one of the previously laminated first electrode and second electrode before one of the subsequent electrodes of the first electrode and the second electrode is laminated. After assembling the laminate, a primary heat press operation including the step of heating and pressing the laminate after gripping the laminate with a gripper may be performed. After performing the primary heat press operation, after removing the gripper, a secondary heat press operation including the step of heating and pressing the laminate may be further performed. The secondary heat press operation may include the step of pressing the laminate for 5 seconds to 60 seconds under a temperature condition of 50°C to 90°C and a pressure condition of 1 Mpa to 6 Mpa.

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

[0022] In an 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. This means that before supplying the first electrode, the second electrode, and the separation membrane to the stack table, as long as the first electrode, the second electrode, and the separation membrane are not damaged by such heating, they can be heated by a commonly used method.

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

[0024] In one embodiment of the present invention, the second heat press operation includes: a step of stopping heating of the stack table and / or a pair of pressure blocks; a step of stopping pressurization of the stack; a step of moving the gripper away from the stack; a step of heating the stack table and / or a pair of pressure blocks to transfer heat to the stack; and a step of pressurizing the laminate between the pair of pressure blocks and / or pressurizing the laminate between the pressure block and the stack table (either one or both may be heated).

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

[0026] In an alternative embodiment of the present invention, one or both of the heat press operations may occur 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. At this time, the gripper may be a holding mechanism of the stack table capable of stabilizing the laminate by fixing the position of the stack relative to the stack table. Further, the holding mechanism may be configured to fix the laminate in such a manner at least during the primary heat press operation.

[0027] In this specification, FIG. 1 is a diagram schematically 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 include a stacking step of alternately stacking a first electrode and a second electrode on a separation membrane and stacking (stacking cells) on a stack table, where the separation membrane is sequentially folded onto one of the first electrode and the second electrode stacked in advance before the subsequent electrode. The first electrode and the second electrode are stacked. After the stacking step, the laminate may be separated from the stack table. During such a time, the separation membrane is pulled, and after the separation membrane is pulled by a predetermined length, the separation membrane is cut. Then, a predetermined length of the cut end of the separation membrane is wound around the stack cell. The movement of the stack away from the stack table can be performed by a gripper, and the gripper is preferably a movable component that can move the laminate on the stack table to a press section where a heat press operation is performed after gripping the laminate. Next, a primary heat press operation is performed while gripping the wound stack cell with the gripper. After the primary heat press operation is completed, the gripping of the stack cell by the gripper is released, and after the gripper is removed, a secondary heat press operation is performed. When the secondary heat press operation is completed, the completed electrode assembly can be completed.

[0028] In an embodiment of the present invention, the temperature condition of the secondary heat press 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 secondary heat press operation may be 90°C or lower, preferably 85°C or lower.

[0030] In an embodiment of the present invention, the temperature condition of the secondary heat press 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 secondary heat press operation may be 70°C.

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

[0032] In an embodiment of the present invention, the pressure condition of the secondary heat press operation is 6 Mpa or lower, and preferably 5.5 Mpa or lower.

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

[0034] In an embodiment of the present invention, the heating and pressurization in the secondary heat press operation may be performed for 5 seconds or longer, preferably 7 seconds or longer.

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

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

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

[0038] Here, the pressure conditions of the primary heat pressing operation and the pressure conditions of the secondary heat pressing operation mean the pressure applied by the pair of pressing blocks (or the pressing blocks against the stack table), and the temperature conditions mean the temperature of the heat applied by the stack table and / or the pair of pressing blocks. Also, the pair of pressing blocks used for the primary heat pressing operation and the secondary heat pressing operation may be the same or different. That is, when the laminate is gripped by the gripper during the primary heat pressing operation, after the laminate is pressurized and heated by the pair of pressing blocks, the gripper is released during the secondary heat pressing operation and the laminate can be pressurized and heated by the same pair of pressing blocks or a different pair of pressing blocks.

[0039] In an alternative embodiment in which at least one of the heat press operations occurs from a stack table, the primary heat press operation may include one pressing block that applies pressure to a 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 the pressing block. During such a primary heat press operation, the laminate may be fixed to the stack table by grippers in the form of a holding mechanism of the stack table. After the primary heat press operation, a secondary heat press operation can be performed with the grippers released from the stack. Such a secondary heat press operation may be performed on the stack table while being pressed by the same or different pressing blocks. Alternatively, the laminate may be moved to a separate press section, where the secondary heat press operation may be performed by applying heat and pressure to the stack by a pair of pressing blocks of the press section.

[0040] If the conditions of temperature, pressure, and time described herein are not met, the components of the electrode assembly may not adhere properly, resulting in breakage of the electrode assembly or misalignment of the components inside the electrode assembly, especially before the electrode assembly is inserted into the battery case. There is also a possibility of a problem that the air permeability of the separator membrane is too high.

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

[0042] Since the layers that have already been laminated will each later experience the applied heat and / or pressure, individually heating and pressing at these respective stages can accumulate the effects of heat and / or pressure in the lower separator membrane within the stack and be detrimental. This can negatively affect such parts of the separator membrane, for example, by reducing the porosity (and air permeability). In contrast, the present invention can bond the entire electrode assembly simultaneously and, above all, improve the uniformity. Therefore, while minimizing damage to the unit electrodes, it is possible to simultaneously achieve an appropriate level of adhesion between the electrodes and a separator membrane having appropriate air permeability.

[0043] In one embodiment of the present invention, the step of manufacturing a laminate by laminating the first electrode, the separator membrane, and the second electrode on a stack table includes: a step of laminating the separator membrane on the stack table (S1); a step of laminating the first electrode on the upper surface of the separator membrane (S2); a step of supplying the separator membrane while rotating the stack table so as to cover the upper surface of the first electrode (S3); and a step of laminating the second electrode on the separator membrane portion covering the upper surface of the first electrode (S4), and the operations of S1 to S4 can be repeated one or more times. By repeating the above operations one or more times, zigzag folding is possible such that the separator membrane is positioned between the first electrode and the second electrode.

[0044] In one embodiment of the present invention, a laminate including at least one of the separator membrane and each of the first electrode and the second electrode may be held by the holding mechanism and fixed to the stack table. The holding mechanism may sometimes be also referred to as a gripper.

[0045] In one embodiment of the present invention, the step of further fixing the first electrode or the second electrode to the stack table when the first electrode or the second electrode is held by the holding mechanism and laminated on the stack table may be further included. By doing so, it is possible to prevent the position of the electrode from shifting from the electrode assembly.

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

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

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

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

[0050] According to an embodiment of the present invention, it is possible to provide an apparatus for manufacturing an electrode assembly by the above-described manufacturing method. Such an apparatus includes, as disclosed herein, a stack table on which a first electrode, a separation membrane, and a second electrode are laminated; a separation membrane supply unit that supplies the 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 stacking unit that stacks the first electrode supplied from the first electrode supply unit on the stack table; a second electrode stacking unit that stacks the second electrode supplied from the second electrode supply unit on the stack table; a press unit that heats and presses a laminate 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 laminate when heated and pressed by the press unit. The press unit performs a first heat press operation by heating and pressing the laminate in a state where the laminate is gripped by the gripper, and performs a second heat press operation by pressing the laminate for 5 seconds to 60 seconds under a temperature condition of 50°C to 90°C and a pressure condition of 1 Mpa to 6 Mpa.

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

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

[0053] Further, the first electrode stack portion may include a first suction head for picking up the first electrode placed on the first electrode placement table by vacuum suction, and the second electrode stack portion may similarly include a second suction head for picking up the second electrode placed on the second electrode placement table by vacuum suction.

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

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

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

[0057] In an 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 an 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 one embodiment of the present invention, the manufacturing apparatus of the electrode assembly may further include a rotating part for rotating the stack table. The first electrode stack part may be provided on one side of the rotating part, and the second electrode stack part may be provided on the other side of the rotating part. Thereby, zigzag folding is possible when the separation membrane is positioned between the first electrode and the second electrode. When the first electrode is laminated alternately, the rotating part rotates the stack table to one side so as to face the first suction head of the first electrode stack part, and when the second electrode is laminated, the rotating part rotates the stack table to the other side so as to face the second suction head of the second electrode stack part.

[0060] In one embodiment of the present invention, the holding mechanism can apply a certain amount of pressure to fix the upper surface of the electrode or the separation membrane located at the uppermost stage of the stack laminated on the stack table.

[0061] The method for measuring the adhesion force of the separation membrane 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 stacking 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 sample is 55 mm and the length is 20 mm, and each sample may include an anode and a separation membrane or a cathode and a separation membrane. The sample was adhered to a slide glass, and the electrode was located on the adhesion surface of the slide glass.

[0062] More specifically, the slide glass with the sample attached was mounted on an adhesion force measuring device, and the force value (g / mm) per sample width when the separation membrane was peeled off from the electrode according to the standard test method described in ASTM-D6862 was measured. Specifically, the edge of the separation membrane was pulled upward at a speed of 100 mm / min with respect to the slide glass at an angle of 90°, and the separation membrane 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, that is, the JIS Gurley measurement method of the Japanese Industrial Standard using a Gurley densitometer (No. 158) manufactured by Toyo Seiki. That is, the air permeability of the separation membrane was determined by measuring the time required for 100 ml (or 100 cc) of air to pass through a one-square-inch separation membrane under a pressure of 0.05 MPa at room temperature.

[0064] FIG. 2 shows a top view illustrating 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, in FIG. 2, the separation membrane supply unit 120 shown in FIG. 3 is omitted for convenience, and in FIG. 3, the holding mechanism 170 shown in FIG. 2 is omitted, and the press unit 180 located at the rear in the top view is indicated by a dotted line.

[0065] Referring to FIGS. 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 stacking unit 150 for stacking the first electrode 11 on the stack table 110, a second electrode stacking unit 160 for stacking the second electrode 12 on the stack table 110, and a press unit 180 for joining the first electrode 11, the separation membrane 14, and the second electrode 12 to each other. The press unit 180 can be used for both the first and second heat press operations described above. Alternatively, the second heat press operation may be performed by another press unit (not shown) involving conveyance between press units after the first heat press operation is completed by the press unit 180.

[0066] Further, the manufacturing apparatus 100 for an electrode assembly 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. Further, the holding mechanism 170 can fix the laminate of the first electrode 11, the separation membrane 14, and the second electrode 12.

[0067] Hereinafter, with reference to FIGS. 2 to 12, a manufacturing apparatus for an electrode assembly according to an embodiment of the present invention will be described in more detail.

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

[0069] Referring to FIGS. 2 to 4, a manufacturing apparatus 100 for an electrode assembly according to an embodiment of the present invention is an apparatus that manufactures the electrode assembly 10 by laminating the first electrode 11, the separation membrane 14, and the second electrode 12.

[0070] The electrode assembly 10 is a charge-dischargeable power generation element, and the first electrode 11, the separation membrane 14, and the second electrode 12 may be alternately laminated and aggregated.

[0071] Here, the electrode assembly 10 may be, for example, such that the separation membrane 14 is folded in a zigzag shape, and the first electrode 11 and the second electrode 12 may be alternately arranged between the folded separation membranes 14. At this time, the electrode assembly 10 may be provided, for example, in a form in which the outermost contour is surrounded by the separation membrane 14 as shown in FIG. 4, or in a form in which the separation membrane surrounds the assembled electrode assembly 10.

[0072] FIG. 5 shows a perspective view of a press part in the manufacturing apparatus for an electrode assembly according to an embodiment of the present invention, and FIG. 6 shows a perspective view of an example in which the press part pressurizes a laminate in the manufacturing apparatus for an electrode assembly. More specifically, FIG. 6 shows the above-described secondary heat press operation.

[0073] Referring to FIGS. 4 to 6, the press unit 180 heats and presses the stacked first electrode 11, separation membrane 14, and second electrode 12 to join the first electrode 11, separation membrane 14, and second electrode 12 to each other.

[0074] Further, the press unit 180 includes a pair of pressing blocks 181, 182, and the pair of pressing blocks 181, 182 move toward each other and affect the pressing of the stack S including the first electrode 11, separation membrane 14, and second electrode 12 that are stacked.

[0075] At this time, when the separation membrane 14 surrounds the outer surface of the stack S, the space between the outer portion of the separation membrane 14 located along the side surface of the stack S and a part of the first electrode and the second electrodes 11, 12 and the folded portion of the separation membrane 14 facing the outer portion may be joined. Thereby, it is possible to more effectively prevent the displacement of the positions of the first electrode and the second electrodes 11, 12 and the separation membrane 14 and the separation of the components of the stack from each other.

[0076] Further, the press unit 180 further includes press heaters 183, 184 for heating the pair of pressing blocks 181, 182, and the pair of pressing blocks 181, 182 can heat and press the stack S. Thereby, when the stack S is pressed by the press unit 180, heat fusion with the first electrode 11, separation membrane 14, and second electrode 12 is performed better, so that stronger adhesion becomes possible.

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

[0078] Further, the pair of pressing blocks 181, 182 includes a first pressing block 181 and a second pressing block 182, and the first pressing block 181 and the second pressing block 182 are each defined as a rectangular parallelepiped-shaped square block.

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

[0080] Referring to FIGS. 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 stacked 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 thereto. 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, and the bodies 121a may each be configured in a rectangular block shape, and the bodies 121a may be separated 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 each body 121a.

[0084] The separation membrane supply unit 120 may further include a separation membrane roll 122 around which the separation membrane 14 is wound. Therefore, the separation membrane 14 wound around the separation membrane roll 122 can be supplied to the stack table 110 through a passage formed by being gradually unwound.

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

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

[0087] The first electrode supply unit 130 includes a first electrode roll 133 around which the first electrode 11 is wound in a sheet form, a first cutter 134 that cuts the sheet-shaped first electrode 11 wound around the first electrode roll 133 at regular intervals to form the first electrode 11 of a predetermined size, a first conveyor belt 135 that moves the first electrode 11 cut by the first cutter 134, and a first electrode supply head 136 that picks up (for example, vacuum-sucks) the first electrode 11 conveyed by the first conveyor belt 135 and places it on the first electrode placement table 131. Here, the first cutter 134 can cut the sheet-shaped first electrode 11 so that a first electrode tab 11a protrudes at an end when cutting.

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

[0089] Referring to FIGS. 3 and 9, the second electrode supply unit 140 can supply the second electrode 12 to the second electrode stack unit 160. Further, 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 around which the second electrode 12 is wound in a sheet form, a second cutter 144 that cuts the sheet-shaped second electrode 12 wound around the second electrode roll 143 at regular intervals to form the second electrode 12 of a predetermined size, a second conveyor belt 145 that moves the second electrode 12 cut by the second cutter 144, and a second electrode supply head 146 that picks up (e.g., vacuum-suction) the second electrode 12 conveyed by the second conveyor belt 145 and places it on the second electrode placement table 141. Here, when cutting the sheet-shaped second electrode 12, the second cutter 144 can be cut so that the second electrode tab 12a protrudes from the end.

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

[0092] Referring to FIGS. 3, 10, and 11, the first electrode stack unit 150 can stack the first electrode 11 on the stack table 110. The first electrode stack unit 150 may include a first suction head 151 and a first moving unit 153. The first suction head 151 can 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 has a vacuum suction port 151a formed on the bottom surface 151b, and the first electrode 11 can be sucked through the vacuum suction port 151a and fixed to the bottom surface 151b of the first suction head 151. Here, a passage connecting the vacuum suction port 151a and a vacuum suction device (not shown) may be formed inside the first suction head 151.

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

[0094] On the other hand, referring to FIG. 3, the second electrode stack portion 160 can stack the second electrode 12 on the stack table 110. Here, the second electrode stack portion 160 may have the same structure as the first electrode stack portion 150 described above. At this time, the second electrode stack portion 160 may include a second suction head 161 and a second moving portion 163. The second suction head 161 can pick up the second electrode 12 placed on the second electrode placement table 141 through vacuum suction. Next, the second moving portion 163 can 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 electrode assembly manufacturing apparatus according to an embodiment of the present invention.

[0096] Referring to FIGS. 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 grip 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 (that is, the first electrode 11, the second electrode 12, or the separation film 14 stacked on the uppermost stage 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 film 14, the holding mechanism 170 can press the stack toward the stack table 110 side to fix the uppermost surface of the stack and prevent the stack S from moving with respect 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. The holders 171 and 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 supplied to the stack table 110 in a state of being unwound from the separation membrane roll 122 in proportion to the rotation amount 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 forms of rotating or pivot shafts. Therefore, when the holding mechanism 170 grips the first electrode 11 or the second electrode 12, the rotating device can rotate the holding mechanism 170 together with the stack table 110.

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

[0099] Referring to FIGS. 2 to 4, the separation membrane 14 wound around the separation membrane roll 122 is supplied while passing through a passage formed so that the separation membrane is laminated on the lamination table 110.

[0100] Further, 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 laminates the first electrode 11 on the upper surface of the separation membrane 14 laminated on the stack table 110.

[0101] Thereafter, the holding mechanism 170 presses 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 in the direction of the second electrode stack unit 160, the separation membrane 14 is continuously supplied so as to cover the upper surface of the first electrode 11.

[0103] Subsequently, the second electrode 12 supplied from the second electrode stack portion 140 is laminated by the second electrode stack portion 160 on the portion covering the upper surface of the separation membrane 14. Thereafter, after the holding mechanism 170 releases the grip on the upper surface of the first electrode 11, it presses the upper surface of the second electrode 12 to secure the position of the laminate S constructed with respect to the stack table 110.

[0104] Thereafter, by repeating the process of laminating the first electrode 11 and the second electrode 12, the separation membrane 14 can be folded in a zigzag manner to form a laminate S positioned between the continuous first electrode and second electrodes 11 and 12.

[0105] Next, the laminate S is moved to the press portion 180, and the press portion 180 heats and presses the laminate S to thermally fuse the components of the stack (i.e., the heated first electrode 11, the separation membrane 14, and the second electrode 12) to manufacture the electrode assembly 10.

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

[0107] Referring to FIGS. 15A and 15B, the first press portion 50 can primarily heat and press the laminate S in a fixed state. The first press portion 50 may include a pair of first pressure blocks 50a and 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 lamination 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 separation membrane 14. As in the illustrated example, the gripper 51 can press the upper and lower surfaces of the laminate S to maintain such relative positions.

[0108] The first pressing blocks 50a and 50b of the pair of first pressing parts 50 can move in a direction away from each other in a direction facing each other. The pair of first pressing blocks 50a and 50b can compress either one or both of the laminate S and the gripper 51 while moving toward each other.

[0109] In this way, the first pressing part 50 can heat and compress the laminate S to reduce or remove the space between the first electrode 11, the separation film 14, and the second electrode 12 included in the laminate S, and bond such components of the laminate S.

[0110] As shown in the drawing, each pressing surface of the pair of first pressing blocks 50a and 50b configured for contacting and compressing the laminate S can be defined as a flat surface. At least one of the pair of first pressing blocks 50a and 50b may include a gripper groove 52 having a shape corresponding to the fixing part 51b of the gripper 51 described in this specification. In the example shown in FIG. 15A, the pair of first pressing blocks 50a and 50b each include four gripper grooves 52, corresponding to the four fixing parts 51b. However, the number of gripper grooves 52 may be more or less. Preferably, the number of the gripper grooves 52 must match the number of the fixing parts used.

[0111] The gripper 51 may include a main body 51a and a plurality of fixing parts 51b. As shown in the illustrated arrangement, the main body 51a can have a length along the x-axis and a height along the y-axis, and each axis can have the same or approximately the same length and height as the length and height of the laminate S. In some other arrangements, the main body can have a length longer than the length of the laminate S in the x-axis and a height larger than the height of the laminate S in the y-axis. The fixing part 51b may preferably be in the form of a rod, column, or plate extending along the width direction (z-axis) of the laminate S. Here, the length of the laminate S in the x-axis means the portion where the distance from one end to the other end of the laminate S is the longest, the height in the y-axis means the distance in the stacking direction of the laminate S, and the width in the z-axis may mean the distance in the direction perpendicular to both the x-axis and the y-axis.

[0112] The fixing parts 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 part 51b can be adjusted in the height direction of the main body 51a. In this way, each fixing part 51b may be arranged so as to contact the upper and lower surfaces of the laminate S, preferably along its width, so as to fix the relative positions of the first electrode 11 and the second electrode 12 in the laminate S and the position of the laminate S.

[0113] In some arrangements, the second pressing part 60 may heat and compress the laminate S that has been pre-heated and compressed by the first pressing part 50 to perform secondary compression on the laminate S that has already been primarily compressed.

[0114] As shown in FIG. 15B, the second pressing part 60 includes a pair of second pressing blocks 60a, 60b. The pair of pressing blocks 60a, 60b may be moved in a direction away from each other. The pair of pressing blocks 60a, 60b can compress the laminate by pressing the upper and lower surfaces of the laminate S when moving relative to each other.

[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 flat surface. As shown, in some arrangements, the grooves for the fixing part 51b may be excluded 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 having a shape corresponding to the fixing part 51b of the gripper 51.

[0116] In some arrangements, each of the pair of first pressure blocks 50a, 50b of the first press part 50 includes a gripper groove 52 having a shape corresponding to the fixing part 51b of the gripper 51, and each of the pair of second pressure blocks 60a, 60b of the second press part 60 has a flat press surface without a gripper groove.

[0117] In some arrangements, the second press part 60 can heat and press only a part of the laminate S where the gripper (or previously) located that is not heated and pressed by the first press part 50. In some other arrangements, the second press part 50 can heat and press the entire upper and lower surfaces of the laminate.

[0118] In some arrangements, the first press part 50 can press the initially heated laminate S with the upper and lower surfaces of the laminate S fixed to the gripper 51 in a fixed state in order to reduce or remove the space between the first electrode 11, the separation film 14 and the second electrode 2 included in the laminate S and bond the components of the laminate S together in the region where the gripper 51 is not located.

[0119] In some such configurations, the second pressing part 60 is pre-joined by the first pressing part 50 and can compress and heat the laminate S from which the gripper 51 has been removed. Thereby, the second pressing part 60 reduces or removes the space between the first electrode 11, the separation membrane 4, and the second electrode 12 included in the laminate S, and can bond such components of the laminate S to each other in the region where the gripper 51 previously pressed the laminate S during the initial pressing operation by the first pressing part 50. In some such arrangements, the pair of second pressing blocks 60a, 60b may each be a rectangular parallelepiped-shaped square block. In such an arrangement, the pair of second pressing blocks 60a, 60b may have the aforementioned flat pressing surfaces.

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

[0121] In some arrangements, the fixing part 51b may include a heat-conductive material such as a heat-conductive metal material selected from the group consisting of aluminum and iron. By conducting heat to the laminate S, when the first pressing part 50 compresses the laminate S fixed by the gripper 51, the electrodes 11, 12, and the separation membrane 4 can have the space therebetween reduced or removed and be joined to each other.

[0122] In some arrangements, the second pressing part 60 does not compress the region of the laminate S where the gripper 51 was previously located, but instead can compress only the region of the laminate S that was not pressed during the initial pressing by the first pressing part 50 and where the gripper 51 was not previously located.

[0123] Further, the pair of first pressing blocks 50a and 50b may each be a rectangular parallelepiped square block. In such an arrangement, the pair of first pressing blocks 50a and 50b can have the flat pressing surfaces described above.

[0124] Either one or both of the first and second pressing portions 50 and 60 preferably include a press heater (not shown) configured to heat one or both of the pair of first and second pressing blocks 50a, 50b, 60a, 60b so as to heat the laminate S when the blocks press the laminate. Thus, when the laminate S is pressed by the first and second pressing portions 50 and 60, the thermal fusion of the first electrode 11, the separation film 14, and the second electrode 12 can be performed more favorably, and a stronger bond can be formed between these layers.

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

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

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

[0128] FIG. 13 is a front view conceptually showing an apparatus for manufacturing an electrode assembly according to another embodiment of the present invention. The holding mechanism is omitted in FIG. 13 for convenience, and the pressing portion 180 located rearward in the plan view is shown by a dotted line.

[0129] Referring to FIG. 13, a manufacturing apparatus 200 for an electrode assembly according to another 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 stacking unit 150 for stacking the first electrode 11 on the stack table 110; a second electrode stacking unit 160 for stacking the second electrode 12 on the stack table 110; a pressing unit 180 for joining 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 laminate 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 and 12.

[0131] Therefore, in this embodiment, the content overlapping 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 apparatus 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 part R can rotate the stack table 110 in one direction r1 and the other direction r2. A first electrode stack part 150 may be provided on one side of the rotating part R, and a second electrode stack part 160 may be provided on the other side of the rotating part R. When the first electrode 11 is laminated, the rotating part R rotates the stack table 110 to one side so as to face the first section head 151, and when the second electrode 12 is laminated, the rotating part R can rotate the stack table 110 to the other side so as to face the second section head 161. By alternately rotating the stack table 110 between the direction facing the first electrode stack part 150 and the second electrode stack part 160, as shown in FIG. 4, the zigzag folding of the separation film 14 between consecutive electrodes of the first electrode 11 and the second electrode 12 can be achieved.

[0134] The device 200 of the present embodiment and all its sub-components operate in the same manner as the device 100 of the foregoing embodiment, unless otherwise mentioned separately. 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] Also, in one embodiment of the present invention, the anode is manufactured, for example, by applying a mixture of an anode active material, a conductive material, and a binder on an anode current collector and then drying, and if necessary, further adding a filler to the mixture. Substances used at this time can be materials commonly used in the art.

[0136] Specifically, the anode 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; the chemical formula Li 1+x Mn 2-xO4 (where x is from 0 to 0.33), lithium manganese oxides such as LiMnO3, LiMn2O3, LiMnO2; lithium copper oxide (Li2CuO2); vanadium oxides such as LiV3O8, LiFe3O4, V2O5, Cu2V2O7; chemical formula LiNi1- x M x O2 (where M = Co, Mn, Al, Cu, Fe, Mg, B or Ga and x = 0.01 to 0.3), Ni-site type lithium nickel oxides represented by; chemical formula LiMn 2-x M x O2 (where M = Co, Ni, Fe, Cr, Zn or Ta and x = 0.01 to 0.1) or lithium manganese composite oxides represented by Li2Mn3MO8 (where M = Fe, Co, Ni, Cu or Zn); LiMn2O4 in which part of the Li in the chemical formula is substituted with alkaline earth metal ions; disulfide compounds; Fe2(MoO4)3 and the like, but not limited thereto.

[0137] Specifically, the anode current collector is not particularly limited as long as it has high conductivity without inducing chemical changes in the battery. For example, stainless steel, aluminum, nickel, titanium, fired carbon, or those surface-treated with carbon, nickel, titanium, silver, etc. on the surface of aluminum or stainless steel can be used, and specifically, aluminum may be used. The current collector can also form fine irregularities on its surface to enhance the adhesive force of the anode active material, and various forms such as films, sheets, foils, nets, porous bodies, foams, non-woven bodies are possible. Further, the anode current collector may generally have a thickness of 3 μm to 500 μm.

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

[0139] The binder is a component that helps bind the active material, conductive material, etc. and bind 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 containing the anode active material. Examples of such binders include polyvinylidene fluoride, polyvinyl alcohol, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinyl pyrrolidone, 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 to suppress the expansion of the anode, and is not particularly limited as long as it is a fibrous material without causing a chemical change in the battery. For example, olefin polymers such as polyethylene and polypropylene; fibrous substances such as glass fibers and carbon fibers are used.

[0141] Also, in one embodiment of the present invention, the cathode is manufactured by applying, drying, and pressing the cathode active material on a cathode current collector, and optionally may further contain, selectively, a conductive material, a binder, a filler, etc. similar to those described above. Also in this case, substances commonly used in the art may be used. Specifically, the cathode active material may be, 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) and other metal composite oxides; lithium metal; lithium alloys; silicon-based alloys; tin-based alloys; 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 films, sheets, foils, nets, porous bodies, foams, non-woven fabric bodies, 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 separation membrane may be an organic / inorganic composite porous SRS (Safety-Reinforcing Separators) separation membrane. The SRS separation membrane may have a structure in which a coating layer component containing inorganic particles and a binder polymer is applied on a polyolefin-based separation membrane substrate.

[0144] Such an SRS separation membrane does not undergo high-temperature thermal shrinkage due to the heat resistance of the inorganic particles. Therefore, even if the electrode assembly is penetrated by a needle-shaped conductor, the elongation rate of the safety separation membrane can be maintained.

[0145] Such an SRS separation membrane can have a uniform pore structure formed by the interstitial volume between the inorganic particles, which are the coating layer components, together with the pore structure contained in the separation membrane substrate itself. The pores can not only significantly mitigate the external impact applied to the electrode assembly, but also enable smooth movement of lithium ions through the pores, and a large amount of electrolyte can be filled to exhibit a high impregnation rate, thus improving the battery performance together.

[0146] In some arrangements, the separation membrane may have a dimension of the width of the separation membrane (perpendicular to the longitudinal dimension in which the separation membrane extends) such that a portion of the separation membrane extends outward from both sides beyond the corresponding edges of the adjacent anode and cathode (hereinafter "excess portion"). Further, the portion extending outside such a separation membrane may have a structure including a coating layer thicker than the thickness of the separation membrane formed on one or both surfaces of the separation membrane to prevent shrinkage of the separation membrane. Details of the thick coating layer of the excess portion extending outside the separation membrane can be referred to Korean Patent Publication No. 10-2016-0054219, the entire content of which is incorporated herein by reference. In some arrangements, each separation membrane excess portion can have a size of 5% to 12% of the width of the separation membrane. Further, in some arrangements, the coating layer may be coated on both surfaces of the separation membrane over a width of 50% to 90% of the width of the excess portion of each separation membrane. Also, the width of the coating layer may be the same or different on each surface of the separation membrane. In some arrangements, the coating layer may include inorganic particles and a binder polymer as components.

[0147] In one embodiment of the present invention, examples of the polyolefin-based separation membrane 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 a size smaller than the thickness of the first electrode or the second electrode. In a specific example, the thickness of the coating layer may be a size of 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 exist in a form (anchoring) in which the pores on the surface of the polyolefin-based separation membrane substrate and the coating layer are intertwined with each other, and the separation membrane substrate and the active layer can be physically firmly bonded.

[0151] At this time, the substrate and the active layer may have a thickness ratio of 9:1 to 1:9, and specifically, may have a thickness ratio of 5:5, considering the physical bonding force and the structure of the pores present on the separation membrane.

[0152] In one embodiment of the present invention, as the inorganic particles, inorganic particles commonly used in the art may be used. The inorganic particles can form empty spaces between the inorganic particles, serve as a kind of spacer that can form micropores and maintain the physical form, and generally have the property that their physical properties do not change even at a high temperature of 200 °C or higher, so that the formed organic / inorganic composite porous film 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 oxidation and / or reduction reactions do not occur within the operating voltage range of the applied battery (for example, 0 to 5V based on Li / Li+). In particular, when using inorganic particles with ion transfer ability, the ion conductivity in the electrochemical element can be increased to improve the performance, so it is preferably as high as possible. Also, when the inorganic particles have a high density, it is not only difficult to disperse them during coating, but there is also a problem of weight increase during battery manufacturing, so it is preferably as low as possible. In the case of inorganic substances with a high dielectric constant, it can contribute to an increase in the dissociation degree of electrolyte salts, such as lithium salts, in the liquid electrolyte, and improve the ion conductivity of the electrolyte solution.

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

[0155] The piezoelectric inorganic particles are substances that are insulators under normal pressure but conduct electricity due to changes in their internal structure when a certain pressure is applied. They not only exhibit a high dielectric constant characteristic with a dielectric constant of 100 or more, but also have the function of generating a potential difference between both sides when a certain pressure is applied and the particles are stretched or compressed, causing charges to be generated and one side to be positively charged and the opposite side to be negatively charged.

[0156] When inorganic particles having the above characteristics are used as a coating layer component, if an internal short circuit occurs between the two electrodes due to an external shock such as a needle-shaped conductor, not only will the anode and cathode not come into direct contact due to the inorganic particles coated on the separation membrane, but also a potential difference will be generated within the particles due to the piezoelectricity of the inorganic particles. As a result, electron transfer between the two electrodes, that is, the flow of a fine current, will occur, thereby achieving a gentle reduction in the battery voltage and an improvement in safety.

[0157] Examples of the inorganic particles having piezoelectricity include, but are not limited to, one or more selected from the group consisting of 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).

[0158] The inorganic particles having the lithium ion conduction ability contain lithium element, but do not store lithium, and refer to inorganic particles having a function of moving lithium ions. Since the inorganic particles having the lithium ion conduction ability can transmit and move lithium ions due to a kind of defect existing inside the particle structure, 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 conduction 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 coating layer components, is not greatly restricted, but can be adjusted within the range of 10:90 to 99:1% by weight, and the range of 80:20 to 99:1% by weight is preferable. When the ratio is less than 10:90% by weight, the content of the polymer becomes excessively large, and the pore size and porosity due to the decrease in the empty space formed between the inorganic particles decrease, leading to a decrease in the final battery performance. Conversely, when the ratio exceeds 99:1% by weight, since the polymer content is too small, the adhesive force between the inorganics becomes weak, and the mechanical properties of the final organic / inorganic composite porous separation membrane may decrease.

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

[0162] Among the organic / inorganic composite porous separation membranes, the coating layer may further contain other commonly known additives in addition to the above-mentioned inorganic particles and binder polymer.

[0163] In one embodiment of the present invention, the coating layer can also be called an active layer.

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

[0165] 1) Example 1 19 anode sheets, 20 cathode sheets, and a long separation membrane were respectively supplied from the anode supply unit, the cathode supply unit, and the separation membrane supply unit to the stack table.

[0166] More specifically, the anode and the cathode are each supplied in a form cut from an anode sheet and a cathode sheet, and the long separation membrane is supplied in the form of a separation membrane sheet. Then, while rotating the stack table as described above, the separation membrane supplied while laminating the anode and the cathode was folded. At this time, the laminate on the stack table was pressed using a holding mechanism to stabilize it, and a laminate including 39 electrodes was manufactured.

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

[0168] After the first heat press step, as shown in Table 1 below, it was heated so that the temperature of the stack table became 70°C temperature conditions, and a pressure (pressure condition) of 2.71 Mpa was applied to the laminate with a press block for 10 seconds (press time), and it proceeded to the second heat press step, and the electrode assembly of Example 1 was produced.

[0169] In the process of manufacturing the electrode assembly, the content described above 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 press step was carried out under the temperature conditions, pressure conditions, and press time shown in Table 1 below. That is, the first heat press conditions of Examples 1 to 12 were the same.

[0171]

Table 1

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

[0173]

Table 2

[0174] Experiments were conducted to pick up the electrode assemblies of Examples 1 to 12 and Comparative Examples 1 to 5 manufactured under the conditions of Tables 1 and 2 above with a suction mechanism under the same conditions as those of the electrode supply unit according to the present invention, and the vacuum suction mechanism was to be maintained for 60 seconds. It was observed that in all of the electrode assemblies of Comparative Examples 1 to 5, the electrode and the separation membrane were separated 60 seconds before. This is because the adhesion state of the electrode and the separation membrane in the electrode assemblies of Comparative Examples 1 to 5 is not good, while the electrode assembly according to the present application (with the first and second presses carried out) has a good adhesion state and has an excellent effect of preventing loosening and falling off of the electrode assembly.

[0175] In the case of Comparative Examples 6 and 7, the phenomenon that the electrode and the separation membrane were separated 60 seconds before was not observed, but it was confirmed that damage occurred in the manufactured electrode assemblies. This is judged to be because the first press was carried out under a pressure condition of 2.54 Mpa (that is, high pressure).

[0176] 4) Experimental Example 1 - Adhesion Force Evaluation After decomposing (i.e., delaminating) the electrode assemblies of Examples 1 to 12 and Comparative Examples 6 and 7 (in the previous test, the phenomenon that the electrode and the separation membrane were separated 60 seconds before was not observed), the separated layers were analyzed to measure the adhesion force between the upper, lower, and middle surfaces of the laminate S. Specifically, the adhesion force between the separation membrane and the cathode located at the lowermost layer of the laminate was measured. Also, the adhesion force between the cathode and the separation membrane located at the uppermost layer of the laminate was measured. Finally, the adhesion force between the cathode and the separation membrane located at the middle position along the lamination direction of the laminate was measured.

[0177] The width of the cathode and the separation membrane sampled in each of the separated electrode assemblies was 55 mm, and the length was 20 mm. The sampled sample was adhered to a slide glass such that the electrode was located on the adhesive surface of the slide glass. Thereafter, after placing the slide glass with the sample adhered thereon in an adhesion force measuring device, a 90° peel test was conducted and tested at a speed of 100 mm / min according to the test method specified in ASTM-D6862 as described above. After discounting the first significant variation, the force (g / mm) applied per sample width while the separation membrane was peeled off from the electrode was measured. The value was measured when the separation membrane was pulled in a direction perpendicular to the plane on which the slide glass was placed and the separation membrane was peeled off from the electrode.

[0178] The results were as shown in Table 3 below.

[0179]

Table 3

[0180] In the case of Comparative Examples 6 and 7 described above, since it proceeded under the pressure condition of 2.54 Mpa as described above, it was confirmed that damage occurred in the electrode assembly. Furthermore, looking at the results in Table 3 above, the deviation of the adhesive force 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 case of Examples 1 to 12, it was confirmed that the deviation of the adhesive force 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 air permeabilities of the electrode assemblies of Examples 1, 6, and 12, which differed only in the temperature conditions of the second press, were evaluated.

[0183] Specifically, after recovering the separation membrane from the electrode assemblies of Examples 1, 6, and 12, the separation membrane was cut to produce separation membrane samples with a size of 5 cm × 5 cm (width × length). Then, the separation membrane samples were washed with acetone.

[0184] Thereafter, according to the Gurley (JIS Gurley) measurement method of Japanese Industrial Standards, using a Toyoseiki Gurley type Densometer (No. 158), the time required for 100 ml (or 100 cc) of air to pass through a one-square-inch separation membrane under normal temperature and a pressure condition of 0.05 MPa was measured to determine the air permeability of Examples 1, 6, and 12.

[0185] The results were as shown in Table 4.

[0186]

Table 4

[0187] From the results in Table 4 above, when the secondary heat press conditions according to the present invention were satisfied, it was confirmed that while having an air permeability level suitable for use as an electrode assembly, the air permeability corresponding to each position was less than 120 sec / 100 ml. The deviation of the air permeability according to each position also appeared to be less than 20 sec / 100 ml and was determined to be substantially uniform. That is, it was confirmed again that the electrode assembly manufactured by the manufacturing method according to the present invention has uniform performance.

[0188] It was confirmed that in the case of Example 1 with a temperature condition of 70°C, the air permeability deviation was the smallest.

[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 Reference Numerals

[0190] 10 ··· Electrode assembly 11 ··· First electrode 11a ··· First electrode tab 12 ··· Second electrode 12a ··· Second electrode tab 14 ··· Separation membrane 50 ··· First press part 50a, 50b ··· First pressure block 51 ··· Gripper 51a ··· Body 51b ··· Fixed part 52 ··· Gripper groove 60 ··· Second press part 60a, 60b ··· Second pressure block 100, 200 ··· Manufacturing apparatus for electrode assembly 110 ··· Stack table 111 ··· Table body 112 ··· Stack table heater 120 ··· Separation membrane supply part 121 ··· Separation membrane heating part 121a ··· Body 121b ··· Separation membrane heater 122 ··· Separation membrane roll 130 ··· First electrode supply part 131 ··· First electrode placement table 133 ··· First electrode roll 134 ··· First cutter 135 ··· First conveyor belt 136 ··· First electrode supply head 140 ··· Second electrode supply part 141 ··· Second electrode placement table 143 ··· Second electrode roll 144 ··· Second cutter 145 ··· Second conveyor belt 146 ··· Second electrode supply head 150 ··· First electrode stack part 151 ··· First suction head 151a ··· Vacuum suction port 151b ··· Bottom surface 153 ··· First moving part 160 ··· Second electrode stack part 161 ··· Second suction head 163 ··· Second moving part 170 ··· Holding mechanism 171 ··· First holder 172 ··· Second holder 180 ··· Pressing part 181, 182 ··· Pressing blocks 183, 184 ··· Pressing heaters 290 ··· Vision device 291 ··· First camera 292 ··· Second camera R ··· Rotating part S ··· Laminate

Claims

1. Assembling an electrode laminate including a plurality of electrodes laminated along a stacking axis and individual separator membrane portions located between the respective electrodes; After assembling the electrode laminate, performing a first heat press operation on the electrode laminate, the first heat press operation including coupling the electrode laminate to a gripper to fix the position of the electrode laminate and heating and pressing the electrode laminate while the gripper is coupled to the electrode laminate; After the first heat press operation, performing a second heat press operation on the electrode laminate, the second heat press operation including separating the gripper from the electrode laminate and then heating and pressing the electrode laminate; The second heat press operation includes pressing the electrode laminate for 5 to 60 seconds under a temperature condition of 50°C to 90°C and a pressure condition of 1 MPa to 6 MPa, a method for manufacturing an electrode assembly.

2. The separator membrane portion is a portion of a long separator membrane sheet, and the step of assembling the electrode laminate includes alternately laminating a first electrode and a second electrode among the electrodes on the long separator membrane sheet, and the long separator membrane sheet is sequentially folded on the first electrode and the second electrode that have been previously laminated before a subsequent electrode is laminated, the method for manufacturing an electrode assembly according to Claim 1.

3. The step of assembling the electrode laminate includes: (1) Positioning the long separator membrane sheet on a stack table; (2) Laminating one of the first electrodes on the upper surface of the long separator membrane sheet; (3) Rotating the stack table while covering the upper surface of one of the first electrodes with the long separator membrane sheet; and (4) Laminating one of the second electrodes on an extended portion of the separator membrane sheet covering the upper surface of one of the first electrodes; including, Repeating the steps (1) to (4) one or more times, the method for manufacturing an electrode assembly according to Claim 2.

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

5. Further including the step of inspecting the lamination state of the first electrode and the second electrode using a camera, the method for manufacturing an electrode assembly according to Claim 2.

6. The method for manufacturing an electrode assembly according to claim 1, wherein both the first heat press operation and the second heat press operation include a step of advancing a pressure block along the stacking axis to engage with the electrode laminate.

7. The method for manufacturing an electrode assembly according to claim 6, wherein the pressure block is heated to transfer heat to the electrode laminate.

8. The method for manufacturing an electrode assembly according to claim 1, wherein the first heat press operation includes a step of heating and pressurizing the electrode laminate for 10 to 30 seconds under temperature conditions of 65°C to 90°C and pressure conditions of 1 MPa to 3 MPa.

9. The method for manufacturing an electrode assembly according to claim 1, wherein the step of assembling the electrode laminate includes a step of winding a long separation sheet around the outer periphery of the electrode laminate.

10. The method for manufacturing an electrode assembly according to any one of claims 1 to 9, further including a step of heating at least one of the electrode and the separation film portion before the step of assembling the electrode laminate.

11. An apparatus for manufacturing an electrode assembly including an electrode laminate in which a plurality of first electrodes and second electrodes laminated along a stacking axis have individual separation film portions positioned between the respective electrodes, a press portion that applies heat and pressure to the electrode laminate to bond the electrodes and the separation film portions within the electrode laminate; and a gripper that includes a gripper for securing the position of the electrode laminate by coupling with the electrode laminate when applying heat and pressure to the electrode laminate by the press portion, wherein the gripper and the press portion are configured to apply heat and pressure to the electrode laminate while the gripper is coupled to the electrode laminate and while the gripper is separated from the electrode laminate.

12. a stack table that supports the electrode laminate; a separation film supply portion that supplies the separation film portion to the stack table; a first electrode supply portion that supplies the first electrode to the stack table; a second electrode supply portion that supplies the second electrode to the stack table; a first electrode stacking portion that moves the first electrode supplied from the first electrode supply portion to the stack table; The apparatus for manufacturing an electrode assembly according to claim 11, further including a second electrode stacking portion that moves the second electrode supplied from the second electrode supply portion to the stack table.

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

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

15. It further includes a rotating unit for rotating the stack table between a first position and a second position. The first position faces the first electrode stack unit to receive the first electrode from the first electrode stack unit, and the second position faces the second electrode stack unit to receive the second electrode from the second electrode stack unit. The manufacturing apparatus for an electrode assembly according to claim 12.

16. The gripper is a device that applies a downward pressure to the upper surface of the electrode laminate along the stacking axis to fix the position of the electrode laminate with respect to the pressing unit. The manufacturing apparatus for an electrode assembly according to claim 11.

17. The pressing unit further includes a pressing block and a press heater for heating the pressing block. The pressing block is configured to advance along the stacking axis of the electrode laminate in order to apply heat and pressure to the electrode laminate. The manufacturing apparatus for an electrode assembly according to any one of claims 11 to 16.

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