Electrode assembly, manufacturing apparatus and method thereof

Abstract

The apparatus for manufacturing an electrode assembly according to the present invention includes a transport unit for transporting an electrode assembly to a sealing position, a plurality of sealing blocks, and a lower support stage. The lower support stage is controlled to move up and down in a first state in which the sealing blocks advance toward the electrode assembly, and both end portions in the length direction of a plurality of separators are bent downward while contacting the sealing blocks and sealed. According to the electrode assembly manufacturing apparatus of the present invention, an end of a separator is heat-sealed in a state where the end is bent downward, so that an electrode assembly that prevents the separator from being pinched during pouch sealing can be manufactured.

Description

[Technical field]

[0001] This application claims the benefit of priority from Korean Patent Application No. 10-2021-0157429 dated November 16, 2021 and Korean Patent Application No. 10-2022-0152709 dated November 15, 2022.

[0002] The present invention relates to an electrode assembly having a structure in which an end of a separator protruding from an electrode is heat-sealed in a state where the end is bent downward in the opposite direction to the stacking direction of the electrode assembly, and to an apparatus and method for manufacturing the electrode assembly. [Background technology]

[0003] In general, a secondary battery is a battery that can be charged and discharged, unlike a primary battery that cannot be charged. Such secondary batteries are widely used in the field of advanced electronic devices such as mobile phones, notebook computers, and camcorders.

[0004] The secondary batteries are classified into a can-type secondary battery in which the electrode assembly is housed in a metal can, and a pouch-type secondary battery in which the electrode assembly is housed in a pouch-type battery case.

[0005] The pouch-type secondary battery includes an electrode assembly, an electrode lead connected to the electrode assembly, and a pouch-type battery case that houses the electrode assembly with the ends of the electrode leads extended to the outside. The electrode assembly has a structure in which electrodes and separators are alternately stacked. At this time, the separator is cut to a size sufficient to cover the entire surfaces of the electrodes, so that the separator protrudes from the ends of the electrode assembly.

[0006] A pouch-type secondary battery is manufactured by placing an electrode assembly inside a pouch-type battery case, and then applying pressure to a sealing portion at a high temperature using a sealing member to seal the battery case. During this sealing process, a separator protruding from the electrode assembly may interfere with and be adhered to the sealing area of ​​the battery case, which is called a separator pinching phenomenon.

[0007] A pouch-type battery case is usually a laminate sheet consisting of an inner coating layer, a metal layer, and an outer coating layer, and the inner coating layer of the area to be sealed is melted by applying pressure at high temperature to the area to be sealed, and the double battery case is heat-sealed. When the area to be sealed is applied with high temperature pressure, not only the inner coating layer of the battery case but also the binder component of the separator may melt, and the inner coating layer of the battery case and the separator may be fused together. This phenomenon is called the separator being pinched.

[0008] If a secondary battery with a pinched separator flows for various reasons, such as due to an external physical impact, the internal electrode assembly may flow and a flow force may be transmitted to the internal coating layer of the battery case attached to the electrode assembly, causing damage such as cracks in the internal coating layer, which may result in insulation failure of the battery case.

[0009] In order to prevent the separator from being pinched, an attempt has been made to heat-seal the ends of the separator during the manufacturing process of the electrode assembly.

[0010] FIG. 1 illustrates a conventional method for heat-sealing the ends of a separator. Referring to FIG. 1, when an electrode assembly 1 is transferred to a sealing position by a conveyor 11, a pair of lower support stands 13 located below both ends of the electrode assembly 1 in the overall length direction rise to support both ends of the electrode assembly 1, and in this state, a sealing block 12 having a preset temperature advances toward the electrode assembly 1 in the direction of the arrow to heat the end of the separator S of the electrode assembly to heat-seal the separator. However, when the ends of the separator are heat-sealed in this process, as shown in FIG. 1, a part of the separator is heat-sealed in a state of being bent upward, and another part is heat-sealed in a state of being bent downward.

[0011] When the separator is folded both upward and downward, some of the separator may become straight again depending on the folding direction during the sealing process of the battery case, resulting in a problem of the separator being pinched. Summary of the Invention [Problem to be solved by the invention]

[0012] In order to solve the above-mentioned problems, the present invention provides an electrode assembly, a manufacturing apparatus and a manufacturing method thereof, in which the heat sealing direction of the separator is controlled downward to prevent the separator from being pinched when the battery case is sealed. [Means for solving the problem]

[0013] According to an embodiment of the present invention, an apparatus for manufacturing an electrode assembly includes a transport unit that transports an electrode assembly, in which a plurality of electrodes and a plurality of separators are alternately stacked, to a sealing position, a plurality of sealing blocks that are configured to advance toward the electrode assembly transported to the sealing position and heat and pressurize the ends of the plurality of separators to seal them, a pair of lower support tables that are located below both end portions in the overall length direction of the electrode assembly and lift and lower to support both end portions in the overall length direction of the electrode assembly for sealing the separators, and a control unit that controls operations of the transport unit, the sealing blocks, and the lower support tables. The control unit controls the lower support tables to move up and down in a first state in which the sealing blocks advance toward the electrode assembly, and as the lower support tables move up and down, both end portions in the overall length direction of the plurality of separators are bent downwardly while contacting the sealing blocks and sealed.

[0014] In the apparatus for manufacturing an electrode assembly according to an embodiment of the present invention, the first state may be a state in which a plurality of sealing blocks are advanced relative to each other such that a distance between a sealing block located on one side and a sealing block located on the other side in a full length direction of the electrode assembly is smaller than a full length of the separator and larger than a full length of the electrode.

[0015] In an electrode assembly manufacturing apparatus according to one embodiment of the present invention, the transfer unit may include a conveyor on which the electrode assembly is placed, and the conveyor may be configured to transfer the electrode assembly in a placed state such that the entire length direction of the electrode assembly intersects perpendicularly with a transfer direction of the conveyor.

[0016] In an electrode assembly manufacturing apparatus according to one embodiment of the present invention, the width direction length of the conveyor is smaller than the overall length of the electrode assembly, and the electrode assembly placed on the conveyor is bent along the overall length such that both end portions in the overall length direction are located below the contact surface height between the conveyor and the electrode assembly.

[0017] In the manufacturing apparatus for an electrode assembly according to an embodiment of the present invention, each of the plurality of sealing blocks is configured to have a shape corresponding to a corner of the electrode assembly. TIFF0007615434000001.tif2832" may have a glyph shape.

[0018] In the apparatus for manufacturing an electrode assembly according to an embodiment of the present invention, each of the sealing blocks may have a curved surface that contacts a corner of the electrode assembly.

[0019] In the apparatus for manufacturing an electrode assembly according to an embodiment of the present invention, the plurality of sealing blocks may include four sealing blocks.

[0020] The electrode assembly manufacturing apparatus according to one embodiment of the present invention further includes a pair of alignment blocks for aligning the electrode assembly, the pair of alignment blocks being disposed on the transfer section and spaced apart a distance corresponding to a widthwise length of the electrode assembly, and the electrode assembly may be placed within the space between the pair of alignment blocks.

[0021] In the apparatus for manufacturing an electrode assembly according to an embodiment of the present invention, the alignment block may be in a bar shape extending along the entire length of the electrode assembly.

[0022] A method for manufacturing an electrode assembly according to an embodiment of the present invention includes: (a) a transporting step of transporting an electrode assembly having a plurality of electrodes and a plurality of separators stacked alternately to a sealing position; (b) a first step of advancing a sealing block located on one side of the electrode assembly in the overall length direction and a sealing block located on the other side of the electrode assembly in the overall length direction toward each other at a predetermined interval toward the electrode assembly; and (c) a second step of sealing the separation membranes at both end portions by bending them downward while contacting the sealing blocks as both end portions of the electrode assembly in the overall length direction are elevated by a support table that ascends and descends toward the electrode assembly from below the electrode assembly.

[0023] In the method for manufacturing an electrode assembly according to an embodiment of the present invention, the preset gap in the first step (b) may be smaller than a total length of the separator and larger than a total length of the electrodes.

[0024] In the method for manufacturing an electrode assembly according to an embodiment of the present invention, the transferring step (a) may include transferring the electrode assembly placed on a conveyor to a sealing position.

[0025] In a method for manufacturing an electrode assembly according to one embodiment of the present invention, the second step (c) may comprise raising and lowering the support table while the sealing blocks are advanced at a preset interval by the first step (b).

[0026] In the method for manufacturing an electrode assembly according to an embodiment of the present invention, the second step (c) may involve heating the separator in contact with the sealing block at a preset temperature, causing a binder component of the separator to melt and form an adhesive force.

[0027] In the method for manufacturing an electrode assembly according to an embodiment of the present invention, an aligning step of aligning the electrode assembly may be further included between the transferring step (a) and the first step (b).

[0028] In the method for manufacturing an electrode assembly according to an embodiment of the present invention, after the second step (c), the method may further include the steps of: moving the sealing blocks advanced in the first step back to their original positions; lowering the lower support table elevated in the second step back to its original position; and transporting the electrode assembly with the separator sealed thereon from the sealing position.

[0029] According to the present invention, there is provided an electrode assembly in which a plurality of electrodes and a plurality of separators are alternately stacked, and the separators protruding from the ends of the electrodes have their ends bent downward in an opposite direction to the stacking direction.

[0030] Also, according to the present invention, there is provided a pouch-type secondary battery having an electrode assembly accommodated in an accommodation portion of a pouch-type battery case, the electrode assembly having a structure in which a plurality of electrodes and a plurality of separators are alternately stacked, the separator protruding from an end of the electrode has an end portion bent in a first direction, and the accommodation portion of the pouch-type battery case protrudes in a flat shape and in a direction opposite to the first direction. Effect of the Invention

[0031] In the electrode assembly manufacturing apparatus and method according to the present invention, an end of a separator is heat-sealed in a bent downward state, so that an electrode assembly and a lithium secondary battery in which the separator is prevented from being pinched when a pouch-type battery case is sealed can be manufactured. [Brief description of the drawings]

[0032] [Figure 1] 1 is a diagram for explaining problems with a conventional method for manufacturing an electrode assembly. [Diagram 2] 1 is a perspective view of an apparatus for manufacturing an electrode assembly according to an embodiment of the present invention; [Diagram 3] 11 is a top view of another electrode assembly manufacturing apparatus according to an embodiment of the present invention. FIG. [Figure 4] 13 is a conceptual diagram for explaining the effect of the operating procedure of the sealing block and the lower support stand. FIG. [Diagram 5] FIG. 1 is a perspective view of a sealing block according to an embodiment of the present invention. [Figure 6] FIG. 13 is a perspective view of a sealing block according to another embodiment of the present invention; [Figure 7] 1 is a diagram showing a pouch-type secondary battery according to an embodiment of the present invention. [Figure 8] 8 is a cross-sectional view taken along line AA' in FIG. 7. [Figure 9] 9 is an enlarged view of a portion of FIG. 8. [Figure 10]4 is a view illustrating a process of accommodating an electrode assembly inside a battery case and sealing the battery case, during a process of manufacturing a pouch-type secondary battery according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] Since the present invention can be modified in various ways and can have various forms, specific embodiments are illustrated in the drawings and described in detail in the text, but it is not intended to limit the present invention to the specific disclosed forms, and it should be understood that the present invention includes all modifications, equivalents, and alternatives falling within the spirit and technical scope of the present invention.

[0034] In this application, the terms "comprise" or "have" are intended to specify the presence of a feature, number, step, operation, component, part, or combination thereof described herein, and should be understood as not precluding the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof. In addition, when a part such as a layer, film, region, or plate is described as being "on" another part, this includes not only the case where it is "directly on" the other part, but also the case where there is another part in between. Conversely, when a part such as a layer, film, region, or plate is described as being "under" another part, this includes not only the case where it is "directly under" the other part, but also the case where there is another part in between. In addition, in this application, being "on" may include not only the case where it is located at the top, but also the case where it is located at the bottom.

[0035] In this specification, the X-axis direction corresponds to the overall length direction of the electrode assembly and the width direction of the conveyor, the Y-axis direction corresponds to the width direction of the electrode assembly and the transfer direction of the conveyor, and the Z-axis direction corresponds to the ascending and descending direction of the lower support platform.

[0036] The electrode assembly manufacturing apparatus of the present invention will be described in detail below.

[0037] FIG. 2 is an oblique view of an electrode assembly manufacturing apparatus according to one embodiment of the present invention, FIG. 3 is an upper view of another electrode assembly manufacturing apparatus according to one embodiment of the present invention, and FIG. 4 is a conceptual diagram for explaining the action and effect according to the operating procedure of the sealing block and the lower support stand.

[0038] 1. Referring to these drawings, an electrode assembly manufacturing apparatus 100 according to one embodiment of the present invention includes a transfer unit 110 that transfers an electrode assembly 1, in which a plurality of electrodes and a plurality of separation membranes are alternately stacked, to a sealing position, a plurality of sealing blocks 120, 121-124 that are configured to be able to advance toward the electrode assembly 1 transferred to the sealing position and that heat and pressurize the ends of the plurality of separation membranes to seal them, a pair of lower support stages 130 that are located below both end portions in the overall length direction (X-axis direction) of the electrode assembly and rise and fall to support both end portions in the overall length direction of the electrode assembly for sealing the separation membranes, and a control unit (not shown) that controls the operations of the transfer unit 110, the sealing blocks 120, and the lower support stage 130.

[0039] The control unit controls the lower support table 130 to move up and down in a first state in which the sealing block 120 advances toward the electrode assembly 1, and as the lower support table 130 moves up and down, both end portions of the separators in the length direction are bent downward while contacting the sealing block 120 and are heat-sealed.

[0040] Here, the first state refers to a state in which the sealing blocks 120, 121 to 124 are close to the electrode assembly so as to be in contact with ends of the separators at both ends in the overall length direction of the electrode assembly.

[0041] With reference to Fig. 4, the process of heat-sealing the ends of a separator using the electrode assembly manufacturing apparatus according to the present invention will be described. Normally, the length of the separator S constituting the electrode assembly 1 in the overall length direction (X-axis direction) is longer than the overall length direction of the electrodes, so that the ends of the separator protrude beyond the ends of the electrodes. The electrode assembly manufacturing apparatus according to the present invention is for heat-sealing such protruding ends of the separator S in a state where they are bent in one direction.

[0042] 4(a) shows a state in which the electrode assembly 1 is transported to the sealing position by the transport unit 110. At this time, the width direction (X-axis direction) length of the means (e.g., conveyor) on which the electrode assembly 1 is placed in the transport unit 110 may be configured to be smaller than the overall length (X-axis direction) length of the electrode assembly. As a result, the center of the electrode assembly is supported by the placement means of the transport unit 110, but both side edges of the electrode assembly located outside the placement means of the transport unit 110 may be gently curved in an arch shape along the overall length (X-axis direction) due to the weight of the electrode assembly itself since there is no means to support them.

[0043] When the electrode assembly 1 is transported to the sealing position, the control unit 140 controls the sealing block 120 to advance toward the electrode assembly 1, and the electrode assembly manufacturing apparatus 100 enters a first state as shown in Fig. 4(b). In the first state, the interval between the alternating sealing blocks 120 may be set to be smaller than the overall length of the separator and larger than the overall length of the electrodes.

[0044] In the first state, the control unit 140 controls the lower support 130 located below the electrode assembly 1 to move up and down. The electrode assembly 1, which was bent in an arch shape, gradually straightens out as the lower support 130 moves up and down, and both ends of the separator are bent downward in a direction opposite to the direction in which the lower support 130 moves up and down while contacting the sealing block 120, and are heat-sealed in a state in which both ends of the separator are bent downward as shown in FIG. 4(c) by being heated and pressurized by the high-temperature sealing block 120.

[0045] In this manner, in the electrode assemblies manufactured by the electrode assembly manufacturing apparatus of the present invention, the ends of the separators are heat-sealed in a state where they are uniformly bent downward. The electrode assemblies in which the ends of the separators are heat-sealed in a state where they are bent downward have the effect of preventing the separators from being pinched, as will be described later with reference to FIG.

[0046] The transfer unit 110 may include a conveyor on which the electrode assembly 1 is placed, and may further include a driving unit (not shown) for moving the conveyor in a transfer direction, and a transfer unit controller (not shown) for controlling the driving unit to stop a transfer operation of the conveyor when the electrode assembly placed on the conveyor is transferred to a sealing position, and to resume the transfer operation of the conveyor when the separator sealing of the electrode assembly is completed.

[0047] The electrode assembly is placed on the conveyor so that the overall length of the electrode assembly perpendicularly intersects with the conveyor's moving direction (Y-axis direction in FIG. 3). The overall length of the electrode assembly placed in this manner is longer than the width of the conveyor (X-axis direction in FIG. 3).

[0048] In the present invention, the width direction length of the conveyor is made smaller than the overall length of the electrode assembly, so that the electrode assembly is not in a straight line along its entire length but is gently curved as shown in FIG. 4. The weight of the electrode assembly naturally positions both ends of the electrode assembly along its entire length lower than the height of the contact surface between the conveyor and the electrode assembly.

[0049] As a result, both end portions of the electrode assembly in the overall length direction are located below the sealing block, so even if the sealing block moves forward in a certain direction in which the electrode assembly is in the first state for sealing, both end portions of the electrode assembly in the overall length direction remain non-contact with the sealing block and are located below the sealing block.

[0050] The first state is a state in which a plurality of sealing blocks are adjacent to the electrode assembly so as to be able to contact the separator protrusions at both ends of the electrode assembly in the overall length direction. In one specific example, the first state is a state in which the sealing blocks are advanced relative to each other so that the distance between the sealing block located on one side and the sealing block located on the other side in the overall length direction of the electrode assembly is smaller than the overall length of the separator and larger than the overall length of the electrode.

[0051] In the first state, when the lower supporter located under the electrode assembly moves upward, both ends of the electrode assembly move upward while being supported by the supporter, and the separation membranes at both ends come into contact with the sealing blocks. At this time, the overall length of the separation membrane between the sealing blocks on one side and the sealing block on the other side is greater than the distance between the sealing blocks, and both ends of the electrode assembly are gently bent due to the load, so that the separation membrane that comes into contact with the sealing blocks while both ends of the electrode assembly move upward naturally bends downward and is sealed, as shown in FIG.

[0052] The plurality of sealing blocks 120 are for heat sealing both ends of the plurality of separators in the overall length direction, and are provided on one side 121, 122 and the other side 123, 124 in the overall length direction of the electrode assembly 1. The sealing blocks in Figs. 2 and 3 are composed of four sealing blocks, and an embodiment in which two are located on one side and two on the other side in the overall length direction of the electrode assembly is shown, but the present invention is not limited to this.

[0053] Sealing blocks 121, 122 on one side and sealing blocks 123, 124 on the other side are configured to be able to move forward toward the electrode assembly or backward in the opposite direction to assume a first state, which is a suitable position for sealing the separator.

[0054] The sealing blocks have a set temperature, so that the sealing blocks can effectively bend and heat seal the ends of the separator by applying heat and pressure to both ends of the separator along its length.

[0055] In one embodiment, each of the sealing blocks may have a coating layer formed on the pressing surface to prevent the binder component of the separation membrane from adhering thereto, and the coating layer may be made of silicon (Si) or Teflon (registered trademark), thereby eliminating the trouble of having to clean the pressing surface of the sealing block every time it is used.

[0056] Meanwhile, the plurality of sealing blocks may further include a position adjusting unit (not shown) for adjusting a position so that the electrode assembly is disposed in the center between one sealing block and the other sealing block. The position adjusting unit may photograph the electrode assembly and the sealing block from above when the electrode assembly is transferred to the sealing position, confirm the center line of the pressure block and the center line of the electrode assembly in the photographed image, and then move the sealing block forward and backward in the direction of the arrow in FIG. 2 so that they coincide with each other.

[0057] FIG. 5 illustrates the shape of a sealing block according to an embodiment. Referring to FIG. 5, each of the sealing blocks has a " The corner portion means a vertex periphery of the electrode assembly in the longitudinal direction, and the sealing block may have a shape of " TIFF0007615434000003.tif3933" shape, the separator protruding from the electrode can be effectively folded and sealed.

[0058] 6 illustrates the shape of a sealing block according to another embodiment. Referring to FIG. 6, each of the sealing blocks 220 has a curved surface that contacts the corner of the electrode assembly. This can prevent damage to the separator when the sealing block is heated and pressurized.

[0059] The lower support 130 is for bending the separator, and may be configured as a pair to support both ends of the electrode assembly in the overall length direction.

[0060] The lower support 130 is controlled to move upward so as to support both ends of the electrode assembly in the full length direction after the sealing block moves to the first state in order to bend the separator downward.

[0061] In one embodiment, the electrode assembly manufacturing apparatus 100 of the present invention may further include a pair of alignment blocks 140 for aligning the electrode assembly 1. The alignment blocks 140 guide and properly align some electrodes or some separators that are misaligned with the alignment direction of the electrode assembly 1. Therefore, the height of the alignment blocks may correspond to the total thickness of the electrode assembly or may be slightly higher than the total thickness of the electrode assembly.

[0062] 2 and 3, the pair of alignment blocks 140 may be bar-shaped and extend along the entire length of the electrode assembly 1 (X-axis direction).

[0063] In addition, in one embodiment, the pair of alignment blocks 140 may be disposed on the conveyor unit 110 and spaced apart from each other by a distance corresponding to the length of the electrode assembly 1 in the width direction (Y-axis direction).

[0064] The method for producing the electrode assembly of the present invention will now be described in detail.

[0065] As shown in FIGS. 2 to 4, a method for manufacturing an electrode assembly according to an embodiment of the present invention includes: (a) a transporting step of transporting an electrode assembly having a plurality of electrodes and a plurality of separators alternately stacked to a sealing position; (b) a first step of advancing a sealing block located on one side of the electrode assembly in the overall length direction and a sealing block located on the other side of the electrode assembly in the overall length direction toward each other at a predetermined interval toward the electrode assembly; and (c) a second step of sealing by bending the separators at the both end portions downward while contacting the sealing blocks as both end portions of the electrode assembly in the overall length direction are elevated by a support table that ascends and descends toward the electrode assembly from below the electrode assembly.

[0066] The above step (a) is a step of transporting the electrode assembly 1, in which a plurality of electrodes and a plurality of separation membranes are alternately stacked, to a sealing position suitable for sealing the separation membranes using a plurality of sealing blocks 120, 121-124 and a pair of support stands.

[0067] In one embodiment, the above-mentioned (a) transferring step may include transferring the electrode assembly to a sealing position with the electrode assembly placed on a conveyor.

[0068] The width of the conveyor is adjusted to be smaller than the overall length of the electrode assembly, so that the electrode assembly is bent along its overall length due to its own load, and both ends are positioned below the height of the conveyor.

[0069] The step (b) is a step of advancing the sealing blocks 120; 121-124 located on both sides of the electrode assembly in the overall length direction toward the electrode assembly at a preset interval so that the intervals between them become narrower.

[0070] The predetermined interval means an interval between sealing blocks that contact the separator to heat and press the separator but do not contact the electrodes. Specifically, the interval may be smaller than the length of the separator in the overall length direction and larger than the length of the electrodes in the overall length direction. Thus, the sealing blocks can stably press and bend both end portions in the overall length direction of the separator, and do not press both end portions in the overall length direction of the electrodes, thereby preventing deformation of the electrodes.

[0071] Meanwhile, an alignment step of aligning the electrode assembly may be further included between the above-mentioned (a) transferring step and (b) step 1. Although some of the electrodes or separators constituting the electrode assembly may be misaligned with respect to the alignment direction of the electrode assembly, the alignment step can ensure that the misaligned electrodes or separators are properly aligned, thereby preventing poor sealing of the separator.

[0072] In the second step (c), the support table is raised and lowered in a state where the sealing blocks have advanced at a preset interval in the first step (b) so that both ends of the separator are brought into contact with the sealing blocks.

[0073] In other words, as the sealing blocks move toward the electrode assembly at a preset interval, the lower support platform moves up and down while supporting both ends of the electrode assembly, and the separation membrane, which has a length longer than the distance between the sealing blocks, comes into contact with the sealing blocks. When the sealing blocks come into contact with both ends of the separation membrane, the both ends of the separation membrane are bent downward to seal (glue) the separation membrane.

[0074] In the second step (c), the sealing block has a set temperature and heats both ends of the separation membrane in the full length direction that is in contact with the sealing block, thereby melting the binder component of the coating layer applied to both ends of the separation membrane to form an adhesive force.

[0075] Here, the set temperature may be 60° C. to 90° C. If the set temperature is less than 60° C., it is difficult to melt the coating layer applied to the separator, and conversely, if the set temperature exceeds 90° C., the separator may shrink and deform, which is not preferable.

[0076] After the separation membranes at both ends of the electrode assembly are sealed by the operation of the sealing blocks and the lower support as described above, the steps of (b) the sealing blocks that advanced in the first step moving backward to their original positions, (c) the lower support table that moved upward in the second step moving downward to its original position, and (c) the electrode assembly with the sealed separation membrane being transported out of the sealing position can be sequentially performed.

[0077] In this way, in the method for manufacturing an electrode assembly according to the present invention, in a state where the sealing blocks, which seal the separation membrane at both end portions in the entire length direction of the electrode assembly, advance at a preset interval, the lower support supports both end portions of the electrode assembly and rises, so that the separation membrane at both end portions is sealed in a state where it is bent downward while contacting the sealing blocks, thereby manufacturing an electrode assembly in which the separation membrane is prevented from being pinched during pouch sealing.

[0078] Hereinafter, an electrode assembly according to the present invention will be described in detail.

[0079] The electrode assembly according to the present invention has a structure in which a plurality of electrodes and a plurality of separators are alternately stacked.

[0080] Here, the electrodes may be positive and negative electrodes. The separator has a larger area than the electrodes to prevent short circuiting between the positive and negative electrodes. That is, both ends of the separator in the overall length direction and both ends in the overall width direction of the electrode assembly protrude beyond both ends of the electrodes in the overall length direction and both ends in the overall width direction, respectively, to prevent short circuiting.

[0081] In particular, the separators protruding from both ends of the electrode in the length direction are bonded to each other in a folded state by the binder component of the separator. Since the separators at both ends of the electrode in the length direction are heat-sealed in a folded state, the electrode assembly of the present invention has an effect of preventing the separators from being pinched when sealing a pouch-type battery case, particularly a single-cup model.

[0082] Fig. 7 is a view showing a pouch-type secondary battery according to an embodiment of the present invention, Fig. 8 is a cross-sectional view taken along line A-A' of Fig. 7, and Fig. 9 is an enlarged view of a portion of Fig. 8. Fig. 10 is a view showing a process of accommodating an electrode assembly inside a battery case and sealing the battery case, in a manufacturing process of the pouch-type secondary battery according to an embodiment of the present invention.

[0083] Referring to these drawings, a pouch-type secondary battery B according to one embodiment of the present invention includes an electrode assembly 1 and a pouch-type battery case 2 that houses the electrode assembly therein, and with the electrode assembly 1 housed within the housing section 23 of the pouch-type battery case 2, the outer periphery of the housing section 23 is sealed and hermetically sealed using a sealing member 30.

[0084] As described above, the electrode assembly 1 may have a structure in which a plurality of electrodes 1c and a plurality of separators S are alternately stacked. The separators S protruding from the ends of the electrodes are fused in a state in which their ends are bent in a first direction.

[0085] The pouch-type battery case 2 may have a structure in which a lower case 22 and an upper case 21 covering the lower case 22 are integrated together, and each of the lower case 22 and the upper case 21 may have a laminate structure in which an inner coating layer, a metal layer, and an outer coating layer are laminated in sequence.

[0086] Either the upper case 21 or the lower case 22 is provided with an electrode assembly receiving portion 23 having a recessed interior for receiving the electrode assembly 1. The electrode assembly 1 is received in the receiving portion 23, and the surface where the lower case 22 and the upper case 21 meet is folded. Then, a sealing portion is formed by heat sealing along the outer periphery of the electrode assembly receiving portion 23 using a sealing member 30, thereby manufacturing a pouch-type secondary battery B.

[0087] 10(a), in one embodiment, when the electrode assembly is disposed on the lower case 22, a first direction, which is a direction in which the end of the separator is bent, is arranged to face the bottom surface of the lower case 22. Then, the lower case 22 is covered with the upper case 21 so that the electrode assembly 1 is accommodated in the receiving portion 23 provided in the upper case 21, and then a sealing process of the battery case is performed. At this time, the receiving portion 23 protrudes on a plane and protrudes in a second direction, which is a direction opposite to the first direction.

[0088] 10(b), the sealing member 30 is used to heat / pressurize the area to be sealed around the periphery of the receiving portion 23, melting the inner coating layers of the upper case 21 and the lower case 22, and heat-sealing the upper case 21 and the lower case 22. Because the electrode assembly receiving portion 23 provided in the upper case 21 protrudes in the second direction, the sealing member 30 heats and pressurizes the area to be sealed in the first direction. Therefore, the direction of heating and pressing by the sealing member 30 coincides with the direction in which the end of the separator in the electrode assembly is bent, preventing the separator from being pinched during the sealing of the battery case. [Explanation of symbols]

[0089] 1: Electrode assembly 10, 100: Electrode assembly manufacturing apparatus 11, 110:Transfer section 12, 120, 121-124, 220: Sealing block 13, 130: Lower support stand 140: Alignment block

Claims

1. a transport unit for transporting an electrode assembly, in which a plurality of electrodes and a plurality of separators are alternately stacked, to a sealing position; configured to advance toward the electrode assembly transferred to the sealing position; A plurality of sealing blocks for sealing the ends of the separation membranes by applying heat and pressure; a pair of lower support tables positioned below both ends of the electrode assembly in the overall length direction and elevating to support both ends of the electrode assembly in the overall length direction for sealing the separator; A control unit that controls the operation of the transfer unit, the sealing block, and the lower support stand, the control unit controls the lower support table to move up and down in a first state in which the sealing block advances toward the electrode assembly, As the lower support platform moves up and down, both ends of the separators in the length direction are bent downward while contacting the sealing block and sealed.

2. The first state is 2. The apparatus for manufacturing an electrode assembly according to claim 1, wherein a plurality of sealing blocks are advanced relative to one another such that a distance between a sealing block located on one side and a sealing block located on the other side in a full length direction of the electrode assembly is smaller than a length of the separator in the full length direction and larger than a length of the electrode in the full length direction.

3. the transfer unit includes a conveyor on which the electrode assembly is placed, 2 . The apparatus for manufacturing an electrode assembly according to claim 1 , wherein the conveyor is configured to transport the electrode assembly while being placed thereon such that a full length direction of the electrode assembly perpendicularly intersects with a transport direction of the conveyor.

4. 4. The electrode assembly manufacturing apparatus according to claim 3, wherein the conveyor has a widthwise length that is smaller than the overall length of the electrode assembly, so that the electrode assembly placed on the conveyor is bent along its overall length, and both end portions in the overall length direction are located below the height of a contact surface between the conveyor and the electrode assembly.

5. Each of the plurality of sealing blocks comprises: The shape of the corner of the electrode assembly is The electrode assembly manufacturing apparatus according to claim 1 , having a " " shape.

6. Each of the plurality of sealing blocks comprises: The electrode assembly manufacturing apparatus according to claim 1 , wherein a surface that contacts the corner portion of the electrode assembly has a curved shape.

7. 2. The apparatus of claim 1, wherein each of the plurality of sealing blocks comprises four sealing blocks.

8. a pair of alignment blocks for aligning the electrode assembly; The pair of alignment blocks are disposed on the conveying part and spaced apart from each other by a distance corresponding to a width direction length of the electrode assembly, The electrode assembly manufacturing apparatus according to claim 1 , wherein the electrode assembly is placed in a space separated by the pair of alignment blocks.

9. The apparatus of claim 8 , wherein the alignment block is bar-shaped and extends along the entire length of the electrode assembly.

10. (a) transferring an electrode assembly having a plurality of electrodes and a plurality of separators alternately stacked to a sealing position; (b) a first step in which a sealing block located on one side of the electrode assembly in a length direction and a sealing block located on the other side of the electrode assembly in a length direction advance toward the electrode assembly at a predetermined interval from each other; and (c) a second step of bending the separation membranes at both ends of the electrode assembly downward while contacting the sealing blocks and being sealed as both ends of the electrode assembly in a length direction are raised by a support table that rises and falls from below the electrode assembly toward the electrode assembly.

11. 11. The method of claim 10, wherein in the first step (b), the preset gap is smaller than a total length of the separator and larger than a total length of the electrodes.

12. The method of claim 10, wherein in the transferring step (a), the electrode assembly is transferred to the sealing position in a state where the electrode assembly is placed on a conveyor.

13. 11. The method of claim 10, wherein in the second step (c), the support table is raised and lowered while the sealing blocks are advanced at the predetermined intervals in the first step (b).

14. 11. The method of claim 10, wherein in the second step (c), the sealing block heats the separator in contact with the sealing block at a preset temperature, and a binder component of the separator melts to form an adhesive force.

15. The method of claim 10, further comprising an aligning step of aligning the electrode assembly between the transferring step (a) and the first step (b).

16. After the second step (c), the sealing blocks advanced in the first step are retracted to their original positions; the lower support platform ascending upward in the second step descending backward to its original position; The method of claim 10 , further comprising the step of removing the electrode assembly from the sealing position after the separator is sealed.

17. An electrode assembly in which a plurality of electrodes and a plurality of separators are alternately stacked, The separator protruding from the end of the electrode has an end portion bent downward in the opposite direction to the stacking direction, The end portions are bonded to each other in a folded state by a binder component of the separator, forming an electrode assembly.

18. A pouch-type secondary battery in which the electrode assembly according to claim 17 is accommodated in a storage section of a single-cup model pouch-type battery case having a structure in which a lower case and an upper case covering the lower case are integrated, a pouch-type secondary battery, wherein the pouch-type battery case accommodation portion provided in the upper case protrudes in the stacking direction.

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