Separator winding roll, separator winding roll manufacturing method, electrode assembly manufacturing apparatus, and electrode assembly manufacturing method

Abstract

An electrode assembly manufacturing apparatus comprises: a separator winding roll in which two or more layers of separators are stacked and wound; a separator supply unit for individually separating the two or more layers of separators from the separator winding roll and supplying same; a first electrode supply unit for supplying a first electrode; a second electrode supply unit for supplying a second electrode; and a winding unit for stacking and winding the individually separated separators between the first electrode and the second electrode and on one outer side of the first electrode or the second electrode.

Description

Separator winding roll, method for manufacturing a separator winding roll, electrode assembly manufacturing device and electrode assembly manufacturing method

[0001] The present invention relates to a membrane winding roll, a method for manufacturing a membrane winding roll, an electrode assembly manufacturing device, and an electrode assembly manufacturing method.

[0002] This application is based on and claims priority to Korean Patent Application No. 10-2023-0193317, filed with the Korean Intellectual Property Office on December 27, 2023, the entire contents of which are incorporated herein by reference.

[0003]

[0004] As technological developments and demand for mobile devices increase, the demand for secondary batteries as an energy source is rapidly increasing. For example, secondary batteries are attracting significant attention not only as a power source for mobile devices such as cell phones, digital cameras, laptops, and wearable devices, but also as a power source for powertrains such as electric bicycles, electric cars, and hybrid electric vehicles.

[0005] Secondary batteries are classified into cylindrical batteries, in which the electrode assembly is housed in a cylindrical metal can, square batteries, in which the electrode assembly is housed in a square metal can, and pouch batteries, in which the electrode assembly is housed in a pouch-shaped case made of aluminum laminate sheet, depending on the shape of the battery case. Among these, cylindrical batteries have the advantages of relatively large capacity and structural stability.

[0006]

[0007] The present invention provides a novel separator in which two or more layers of separators are laminated and wound.

[0008] The present invention provides a method for manufacturing a separator in which two or more layers of separators are laminated and wound.

[0009] The present invention provides an electrode assembly manufacturing device having a simplified process structure by including one separator supply section using a novel separator winding roll in which two or more layers of separators are laminated and wound.

[0010] The present invention provides a method for manufacturing an electrode assembly with a simplified process procedure by including one separator supply section using a separator winding roll in which two or more layers of separators are laminated and wound.

[0011]

[0012] According to one aspect of the present invention, a membrane winding roll, an electrode assembly manufacturing device, and an electrode assembly manufacturing method of the following embodiments are provided.

[0013] According to the first embodiment, a membrane winding roll is provided in which two or more layers of membranes are laminated and wound.

[0014] According to a second embodiment, in the first embodiment, the two or more layers of separators may include a first separator and a second separator, and the winding length of the second separator may be longer than the winding length of the first separator.

[0015] According to a third embodiment, in any one of the first and second embodiments, the two or more layers of the separator include a first separator and a second separator, and one of the winding ends of the first separator and the second separator is wound so as to wrap over the other, so that one of the winding ends can be unwound before the other when unwinding.

[0016] According to a fourth embodiment, in any one of the first to third embodiments, the two or more layers of the separator may include a first separator and a second separator, the first separator may include a first porous polymer substrate and a first inorganic heat-resistant layer including first inorganic particles and a first binder polymer on at least one surface of the first porous polymer substrate, and the second separator may include a second porous polymer substrate and a second inorganic heat-resistant layer including second inorganic particles and a second binder polymer on at least one surface of the second porous polymer substrate.

[0017] According to a fifth embodiment, in the fourth embodiment, a heat-resistant film may be further included on at least one of the first inorganic heat-resistant layer and the second inorganic heat-resistant layer.

[0018] According to a sixth embodiment, a method for manufacturing a membrane winding roll comprises the steps of: feeding a first mixture of a first diluent and a first polymer resin into an extruder, followed by extrusion and cooling to obtain a first unstretched sheet; feeding a second mixture of a second diluent and a second polymer resin into an extruder, followed by extrusion and cooling to obtain a second unstretched sheet; laminating the first unstretched sheet and the second unstretched sheet to obtain an unstretched laminated sheet; first stretching the unstretched laminated sheet in a first direction to obtain a firstly laminated laminated sheet; second stretching the firstly stretched laminated sheet in a second direction to obtain a secondly stretched laminated sheet; and extracting the first diluent and the second diluent from the secondly stretched laminated sheet to obtain a laminated separator in which a first membrane and a second membrane are laminated. A method for manufacturing a membrane winding roll is provided, characterized in that it includes a step of winding the obtained laminated membrane.

[0019] According to the seventh embodiment, in the sixth embodiment, the step of heat-fixing the laminated separator may be further included.

[0020] According to an eighth embodiment, in any one of the sixth to seventh embodiments, the first mixture may further include a first initiator and a first crosslinking agent, the second mixture may further include a second initiator and a second crosslinking agent, and the step of crosslinking the laminated separator from which the first diluent and the second diluent are extracted may be further included.

[0021] According to a ninth embodiment, a method for manufacturing a membrane winding roll comprises the steps of: feeding a third mixture of a third diluent and a third polymer resin into an extruder, followed by extrusion and cooling to obtain a third unstretched sheet; feeding a fourth mixture of a fourth diluent and a fourth polymer resin into an extruder, followed by extrusion and cooling to obtain a fourth unstretched sheet; first stretching the third unstretched sheet and the fourth unstretched sheet in a first direction, respectively, to obtain first-stretched third sheets and fourth sheets; second stretching the first-stretched third sheets and fourth sheets in a second direction, respectively, to obtain second-stretched third sheets and fourth sheets; second extracting the third diluent and the fourth diluent from the second-stretched third sheets and fourth sheets, respectively, to obtain a third porous polymer substrate and a fourth porous polymer substrate; A method for manufacturing a membrane winding roll is provided, comprising: a step of forming a third inorganic heat-resistant layer by applying and drying a slurry for forming a third inorganic heat-resistant layer comprising third inorganic particles and a third binder polymer on at least one surface of the obtained third porous polymer substrate; a step of forming a fourth inorganic heat-resistant layer by applying and drying a slurry for forming a fourth inorganic heat-resistant layer comprising fourth inorganic particles and a fourth binder polymer on at least one surface of the obtained fourth porous polymer substrate; and a step of stacking and winding the third porous polymer substrate on which the third inorganic heat-resistant layer is formed and the fourth porous polymer substrate on which the fourth inorganic heat-resistant layer is formed.

[0022] According to the tenth embodiment, in the ninth embodiment, the step of heat-fixing the third porous polymer substrate and the fourth porous polymer substrate from which the third diluent and the fourth diluent are extracted may be further included.

[0023] According to an eleventh embodiment, in any one of the ninth to tenth embodiments, the third mixture may further include a third initiator and a third crosslinking agent, the fourth mixture may further include a fourth initiator and a fourth crosslinking agent, and the third diluent and the fourth diluent may further include a step of crosslinking the third porous polymer substrate and the fourth porous polymer substrate from which they are extracted.

[0024] According to the 12th embodiment, in any one of the 9th to 11th embodiments, the winding step may further include stacking an interlayer film on at least one of the third inorganic heat-resistant layer and the fourth inorganic heat-resistant layer, and then winding.

[0025] According to a 13th embodiment, an electrode assembly manufacturing device is provided, characterized by including a membrane winding roll in which two or more layers of membranes are laminated and wound; a membrane supply unit for individually separating and supplying the two or more layers of membranes from the membrane winding roll; a first electrode supply unit for supplying a first electrode; a second electrode supply unit for supplying a second electrode; and a winding unit for respectively laminating and winding the individually separated membranes between the first and second electrodes and on an outer side of the first or second electrode.

[0026] According to the 14th embodiment, in the 13th embodiment, the two or more layers of separation membranes laminated on the separation membrane winding roll may include a first separation membrane and a second separation membrane, and the winding length of the second separation membrane may be longer than the winding length of the first separation membrane.

[0027] According to the 15th embodiment, in any one of the 13th to 14th embodiments, the two or more layers of separation membranes laminated on the separation membrane winding roll include a first separation membrane and a second separation membrane, and one of the winding ends of the first separation membrane and the second separation membrane is wound so as to wrap over the other, so that one of the winding ends may be unwound before the other during unwinding.

[0028] According to the 16th embodiment, in any one of the 13th to 15th embodiments, the two or more layers of separation membranes laminated on the separation membrane winding roll may include a first separation membrane and a second separation membrane, and the winding unit may sequentially laminate and wind the first electrode, the first separation membrane, the second electrode, and the second separation membrane.

[0029] According to a 17th embodiment, in the 16th embodiment, it may include at least one first guide roller for supplying the first separator supplied by unwinding the separator winding roll between the first electrode and the second electrode; and at least one second guide roller for supplying the second separator supplied by unwinding the separator winding roll in a direction facing one side of one of the first electrode and the second electrode.

[0030] According to the 18th embodiment, in the 17th embodiment, the at least one second guide roller may be arranged so that the second membrane supply path from the membrane supply unit to the winding unit bypasses the first electrode supply unit or the second electrode supply unit.

[0031] According to the 19th embodiment, in any one of the 16th to 18th embodiments, the winding length of the second separator may be longer than the winding length of the first separator.

[0032] According to the 20th embodiment, in any one of the 16th to 19th embodiments, the winding length of the second separation membrane is longer than the winding length of the first separation membrane, and the difference between the winding length of the second separation membrane and the winding length of the first separation membrane may be equal to or longer than the difference between the length of the second separation membrane supply path from the separation membrane supply unit to the winding unit and the length of the first separation membrane supply path from the separation membrane supply unit to the winding unit.

[0033] According to the 21st embodiment, a method for manufacturing an electrode assembly is provided, comprising: a step of individually separating two or more layers of separators from a membrane winding roll in which two or more layers of separators are laminated and wound; a step of supplying the separated individual separators; a step of supplying a first electrode; a step of supplying a second electrode; and a step of respectively laminating and winding the individually separated separators between the first electrode and the second electrode and on an outer side of the first electrode or the second electrode.

[0034] According to the 22nd embodiment, in the 21st embodiment, the step of supplying the separator, the step of supplying the first electrode, the step of supplying the second electrode, and the step of stacking and winding the separator may be performed simultaneously after the step of separating the two or more layers of separator into individual pieces.

[0035] According to the 23rd embodiment, in any one of the 21st to 22nd embodiments, the two or more layers of separators may include a first separator and a second separator, and the step of laminating and winding the separators may be to sequentially laminate and wind the first electrode, the first separator, the second electrode, and the second separator.

[0036] According to the 24th embodiment, in the 23rd embodiment, the winding length of the second separator may be longer than the winding length of the first separator.

[0037] According to a 25th embodiment, in any one of the 23rd to 24th embodiments, the step of individually separating the two or more layers of separation membranes from the separation membrane take-up roll is performed using a separation membrane supply unit, and the step of respectively stacking and winding the separated separation membranes is performed using a winding unit, and the winding length of the second separation membrane is longer than the winding length of the first separation membrane, and the difference between the winding length of the second separation membrane and the winding length of the first separation membrane may be equal to or longer than the difference between the length of the second separation membrane supply path from the separation membrane supply unit to the winding unit and the length of the first separation membrane supply path from the separation membrane supply unit to the winding unit.

[0038] According to the 26th embodiment, a method for manufacturing an electrode assembly is provided, including a step of sequentially stacking and winding in one direction a first electrode, a first separator, a second electrode, and a second separator in a roll-to-roll manner, wherein the first separator and the second separator are wound in a roll and overlapped, and then supplied as individual sheets by unwinding.

[0039]

[0040] Since the separator winding roll of the present invention is wound by stacking two or more layers of separators, each separator can be provided as a single sheet to different paths of an electrode assembly manufacturing device.

[0041] The method for manufacturing a membrane winding roll of the present invention can provide a method for manufacturing a membrane winding roll with a simplified process procedure by manufacturing an unstretched sheet using a diluent and a polymer resin, and simultaneously stretching a plurality of unstretched sheets by laminating them.

[0042] Since the electrode assembly manufacturing device of the present invention uses one separator supply unit, only one separator winding roll replacement is required when the separator is exhausted, so that maintenance of the electrode assembly manufacturing device can be advantageous.

[0043] In addition, since the electrode assembly manufacturing device of the present invention includes only one separator supply section, the process structure of the electrode assembly manufacturing device can be simplified. For example, the supply paths of the cathode, anode, and separator in the electrode assembly manufacturing device of the present invention can be simplified compared to conventional methods.

[0044] The electrode assembly manufacturing method of the present invention can simplify the process procedure by using a separator winding roll in which two or more layers of separators are laminated and wound. In addition, the electrode assembly manufacturing method of the present invention enables a continuous process by replacing the separator winding roll once when the separator is exhausted.

[0045]

[0046] The following drawings attached to this specification illustrate preferred embodiments of the present invention, and serve to further understand the technical idea of ​​the present invention together with the contents of the invention described above, and therefore the present invention should not be interpreted as being limited to matters described in such drawings.

[0047] Figure 1 schematically illustrates the structure of a membrane winding roll according to one embodiment of the present invention.

[0048] Figure 2 schematically illustrates the structure of a membrane winding roll according to another embodiment of the present invention.

[0049] Figure 3 schematically illustrates the structure of an electrode assembly manufacturing device according to one embodiment of the present invention.

[0050] Figure 4 schematically illustrates the structure of an electrode assembly manufacturing device according to another embodiment of the present invention.

[0051] Figure 5 schematically illustrates the structure of an electrode assembly manufacturing device according to another embodiment of the present invention.

[0052] Figure 6 is a flowchart of a method for manufacturing an electrode assembly according to one embodiment of the present invention.

[0053] In some of the accompanying drawings, corresponding components are designated by the same reference numerals. Those skilled in the art will appreciate that the drawings illustrate elements simply and clearly and are not necessarily drawn to scale. For example, to facilitate understanding of various embodiments, the dimensions of some elements depicted in the drawings may be exaggerated relative to other elements. Furthermore, elements of known technology that are useful or essential in commercially feasible embodiments may often not be depicted so as not to obscure the spirit of various embodiments of the present invention.

[0054]

[0055] Terms or words used in this specification and claims should not be interpreted as limited to their usual or dictionary meanings, but should be interpreted as meanings and concepts that conform to the technical idea of ​​the present invention, based on the principle that the inventor can appropriately define the concept of the term to explain his or her own invention in the best way.

[0056] The terminology used herein is for the purpose of describing exemplary embodiments only and is not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise.

[0057] Justice

[0058] Throughout this specification, when it is said that a part "includes" a component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise specifically stated.

[0059] Throughout this specification, when a layer is said to be located on “one surface” or “one side” of another layer, this means not only when the layer is in contact with one surface of the other layer, but also when another layer exists between the two layers.

[0060]

[0061] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein. In addition, in the drawings, parts irrelevant to the description have been omitted to clearly explain the present invention, and similar parts have been designated with similar reference numerals throughout the specification.

[0062]

[0063] The electrode assembly built into the battery case is a charge-and-discharge power plant composed of a stacked structure of a positive electrode, a separator, and a negative electrode, and is classified into jelly-roll type, stack type, and stack / folding type. The jelly-roll type is a form in which a separator is interposed between long sheet-shaped positive and negative electrodes coated with active materials and wound around them. The stack type is a form in which a plurality of positive and negative electrodes of a predetermined size are sequentially stacked with a separator interposed between them. The stack / folding type is a composite structure of the jelly-roll type and the stack type. Among them, the jelly-roll type electrode assembly has the advantages of being easy to manufacture and having a high energy density per weight.

[0064] Meanwhile, the jelly-roll type electrode assembly is formed by stacking a cathode, a separator on the cathode, an anode on the separator, and a separator on the anode. For this purpose, a winding device including one cathode supply section, one cathode supply section, and two separator supply sections is typically required. Each supply section of the winding device is equipped with a winding roll on which the cathode, anode, and separator are each prepared in sheet form and wound. If the material from any one of the four winding rolls is exhausted or a process problem occurs, the winding process of the electrode assembly must be stopped. In particular, in the case of a separator, there is a disadvantage in that the winding rolls must be replaced twice because there are two winding rolls. In addition, since the winding device must include one cathode supply section, one cathode supply section, and two separator supply sections, the paths of the cathode, anode, and separator and the structure of the winding device are complicated and maintenance is disadvantageous.

[0065] In the present invention, taking such circumstances into consideration, a jelly-roll type electrode assembly manufacturing device and an electrode assembly manufacturing method with simplified process procedures are provided by including one separator supply section, thereby being more advantageous in maintenance.

[0066]

[0067] <Separator winding roll>

[0068] The present invention provides a membrane winding roll according to one embodiment.

[0069] According to one aspect of the present invention, the present invention provides a membrane winding roll in which two or more layers of membranes are laminated and wound. The number of membrane layers of the membrane winding roll of the present invention may be two or more layers, and there is no particular limitation on the number of membrane layers.

[0070] Fig. 1 schematically illustrates the structure of a membrane winding roll according to one embodiment of the present invention. Fig. 2 schematically illustrates the structure of a membrane winding roll according to another embodiment of the present invention.

[0071] In one embodiment of the present invention, the separator winding roll (10) may include a first separator (11) and a second separator (12), as illustrated in FIG. 1, and these two layers of separators (11, 12) may be laminated and wound into one roll. At this time, the first separator (11) may refer to a separator located at a center of the separator winding roll (10) relative to the second separator (12). Since the separator winding roll (10) has two layers of separators (11, 12) laminated, each separator (11, 12) can be provided as a single sheet through different paths in an electrode assembly manufacturing device (100) using one separator winding roll (10).

[0072] In one embodiment of the present invention, the winding length of the first separator (11) and the winding length of the second separator (12) may be the same. Alternatively, the winding length of the second separator (12) may be longer than the winding length of the first separator (11). In this case, the 'winding length' refers to the total length in the longitudinal direction of the separator wound on the separator winding roll (10).

[0073] In one embodiment of the present invention, when the winding length of the first separation membrane (11) and the winding length of the second separation membrane (12) are the same, either the first separation membrane (11) or the second separation membrane (12) may be exhausted first, but there is an advantage in that the separation membrane winding roll (10) can be easily stored.

[0074] In one embodiment of the present invention, when the winding length of the second separator (12) is longer than the winding length of the first separator (11), it can be naturally separated into the first separator (11) and the second separator (12) without the aid of a separate device. At this time, the difference between the winding length of the second separator (12) and the winding length of the first separator (11) can be adjusted to suit the purpose depending on the electrode assembly manufacturing device (100) in which the separator winding roll (10) is used.

[0075] In one embodiment of the present invention, when unwinding the membrane take-up roll (10), the first membrane (11) and the second membrane (12) may be unwound simultaneously, or one of the first membrane (11) and the second membrane (12) may be unwound before the other.

[0076] In one embodiment of the present invention, the winding ends of the first separator (11) and the second separator (12) may overlap at the same position. As another example, one of the winding ends of the first separator (11) and the second separator (12) may be wound so as to cover over the other.

[0077] As illustrated in Fig. 1, the second separator (12) is wound so as to extend beyond the first separator (11), so that the second separator (12) can be unwound before the first separator (11) during unwinding. By the above method, two or more layers of separators (11, 12) can be naturally separated into the first separator (11) and the second separator (12) without the aid of a separate device.

[0078] Meanwhile, the membrane winding roll (10) of the present invention may include a first membrane (11), a second membrane (12), and a third membrane (13), as illustrated in FIG. 2, and these three layers of membranes (11, 12, 13) may be laminated and wound into one roll. At this time, the first membrane (11) may refer to a membrane positioned at the center of the membrane winding roll (10) relative to the second membrane (12) and the third membrane (13). In addition, the second membrane (12) may refer to a membrane positioned at the center of the membrane winding roll (10) relative to the third membrane (13). As shown in Fig. 2, the present invention is a membrane winding roll (10) in which multiple layers of membranes are laminated and wound. Fig. 2 only illustrates three layers of membranes (11, 12, 13) laminated, but the number of laminated membranes can be increased without limitation. Meanwhile, in the present specification, a membrane in which two or more layers of membranes are laminated is also referred to as a 'overlapping wound membrane'.

[0079] In one embodiment of the present invention, the membrane may have a winding length of about 100 m to 10,000 m, 1,000 m to 7,000 m, or 2,000 m to 5,000 m.

[0080] In one embodiment of the present invention, the membrane winding roll may have two or more layers of membranes wound on a bobbin, but the membrane winding roll may not include the bobbin.

[0081]

[0082] In one embodiment of the present invention, each of two or more layers of separators wound around a separator winding roll may include a porous polymer substrate.

[0083] In the present specification, if the separator comprises only a porous polymer substrate, the separator and the porous polymer substrate may be used as the same. On the other hand, if the separator comprises an inorganic heat-resistant layer on the porous polymer substrate, the separator may comprise both the porous polymer substrate and the inorganic heat-resistant layer.

[0084] In one embodiment of the present invention, the porous polymer substrate refers to a substrate having a plurality of pores formed therein as a porous ion-conducting barrier that allows ions to pass while blocking electrical contact between the cathode and the anode. The pores are structured to be interconnected, allowing gas or liquid to pass from one side of the substrate to the other.

[0085] In one embodiment of the present invention, the porous polymer substrate may be, for example, a porous polymer film substrate or a porous polymer nonwoven fabric substrate.

[0086] The material constituting the porous polymer substrate can be either an organic or inorganic material with electrical insulation properties. From the perspective of imparting a shutdown function to the porous polymer substrate, it is preferable to use a thermoplastic resin as the constituent material of the porous polymer substrate. Here, the shutdown function refers to the function in which, when the battery temperature rises, the thermoplastic resin melts and closes the pores of the porous substrate, thereby blocking the movement of ions and preventing thermal runaway of the battery.

[0087] The porous polymer substrate may be a porous polymer substrate made of polyolefin such as polyethylene or polypropylene, and such a polyolefin porous polymer substrate exhibits a shutdown function at a temperature of, for example, 80°C to 130°C.

[0088] At this time, the polyolefin porous polymer substrate can be formed into a polymer by using a single or a mixture of two or more types of polyolefin polymers such as polyethylene, polypropylene, polybutylene, polypentene, etc., such as high-density polyethylene, linear low-density polyethylene, low-density polyethylene, and ultra-high molecular weight polyethylene.

[0089] In addition, the porous polymer substrate may be manufactured by forming a film shape using various polymers such as polyester in addition to polyolefin. In addition, the porous polymer substrate may be formed by laminating two or more layers of porous polymer substrates, and each layer may be formed of a single polymer such as the aforementioned polyolefin or polyester, or a polymer obtained by mixing two or more types thereof.

[0090] In addition, the porous polymer substrate may be formed of a polymer, either singly or in combination, of polyethyleneterephthalate, polybutyleneterephthalate, polyester, polyacetal, polyamide, polycarbonate, polyimide, polyetheretherketone, polyethersulfone, polyphenyleneoxide, polyphenylenesulfide, polyethylenenaphthalene, etc., in addition to the polyolefins described above.

[0091] The thickness of the porous polymer substrate is not particularly limited, but may be about 1 µm to 100 µm, or about 5 µm to 50 µm, and the pore size and pore content present in the porous polymer substrate are also not particularly limited, but may be about 0.01 µm to 50 µm and about 10% to 95%, respectively.

[0092] Meanwhile, the terms “about,” “approximately,” and “substantially” used in this specification are used to mean a range of values ​​or degrees or something close to them, taking into account inherent manufacturing and material tolerances.

[0093] In one embodiment of the present invention, the weight average molecular weight of the polyolefin may be 100,000 to 5,000,000. If the weight average molecular weight is less than 100,000, it may be difficult to secure sufficient mechanical properties. In addition, if it exceeds 5,000,000, the shutdown characteristics may deteriorate or molding may become difficult. In addition, the puncture strength of the porous polymer substrate may be 300 gf or more from the viewpoint of improving the manufacturing yield. The puncture strength of the porous substrate refers to the maximum puncture load (gf) measured by performing a puncture test under the conditions of a needle tip radius of 0.5 mm and a puncture speed of 4 mm / sec using a Kato tech KES-G5 handy compression tester.

[0094]

[0095] In one embodiment of the present invention, when the separator comprises only the porous polymer substrate, even if two or more layers of separators are laminated and wound, the separators are not adhered to each other, so that they can be naturally separated without any additional force or device when separated into individual sheets. Accordingly, when a separator comprising two or more layers of laminated separators is overlapped and wound, an interlayer film such as a release paper to separate the two or more layers of separators is not required, thereby providing an advantage in the process.

[0096]

[0097] Meanwhile, in one embodiment of the present invention, the separator may optionally include an inorganic heat-resistant layer on at least one surface of the porous polymer substrate, i.e., the separator. The inorganic heat-resistant layer may include inorganic particles and a binder polymer.

[0098] For example, the two or more layers of the separator may include a first separator and a second separator, the first separator may include a first porous polymer substrate and a first inorganic heat-resistant layer including first inorganic particles and a first binder polymer on at least one surface of the first porous polymer substrate, and the second separator may include a second porous polymer substrate and a second inorganic heat-resistant layer including second inorganic particles and a second binder polymer on at least one surface of the second porous polymer substrate.

[0099]

[0100] In one embodiment of the present invention, the first binder polymer and the second binder polymer (hereinafter also referred to as binder polymer) can play a role in connecting and fixing inorganic particles within the inorganic heat-resistant layer.

[0101] In one embodiment of the present invention, the binder polymer may include a particulate binder polymer or a non-particulate binder polymer. The "particulate" binder polymer may refer to a binder polymer that is added to a dispersion medium in a particulate form and then coated and dried to maintain the added particle shape. The "non-particulate" binder polymer may refer to a binder polymer that is dissolved in a solvent when forming an inorganic heat-resistant layer and then coated and dried, or that is added to a dispersion medium in a particulate form but does not maintain the particle shape by coating and drying.

[0102] In one embodiment of the present invention, non-limiting examples of the binder polymer include polyvinylidene fluoride, polyvinylidene fluoride-co-hexafluoropropylene, polyvinylidene fluoride-co-trichloroethylene, polymethylmethacrylate, polybutylacrylate, polybutylmethacrylate, polyacrylonitrile, polyvinylpyrrolidone, polyvinylacetate, polyethylene-co-vinyl acetate, polyethylene oxide, polyarylate, cellulose acetate, cellulose acetate butyrate. Examples thereof include, but are not limited to, cellulose acetate propionate, cyanoethylpullulan, cyanoethylpolyvinylalcohol, cyanoethylcellulose, cyanoethylsucrose, pullulan, polyacrylic acid, and carboxyl methyl cellulose.

[0103] In one embodiment of the present invention, the first binder polymer and the second binder polymer may be the same or different. For example, the first binder polymer and the second binder polymer may be of different types depending on the electrode surfaces, thereby controlling the negative electrode-separator adhesion and the positive electrode-separator adhesion.

[0104] According to one embodiment of the present invention, the binder polymer can be divided into a dispersant binder polymer that also functions as a dispersant and a non-dispersant binder polymer. The dispersant binder polymer is a polymer having at least one dispersion-contributing functional group in the main chain or side chain of the polymer, and the dispersion-contributing functional group may include an OH group, a CN group, or the like. Examples of such dispersant binder polymers may include cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethylpullulan, cyanoethylpolyvinylalcohol, cyanoethylcellulose, cyanoethylsucrose, pullulan, carboxyl methyl cellulose, and the like. Non-dispersant binder polymers may include examples of the above binder polymers excluding the dispersant binder polymer.

[0105]

[0106] The above 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 can be used within the operating voltage range of the applied electrochemical device (e.g., Li / Li). +There are no particular limitations as long as no oxidation and / or reduction reaction occurs at a voltage of 0 to 5 V as a standard. In particular, when using inorganic particles with a high dielectric constant as inorganic particles, it can contribute to increasing the degree of dissociation of electrolyte salts, such as lithium salts, in the liquid electrolyte, thereby improving the ionic conductivity of the electrolyte.

[0107] Non-limiting examples of the above inorganic particles include high-k inorganic particles having a dielectric constant of about 5 or greater, or about 10 or greater, inorganic particles having lithium ion transport capabilities, or mixtures thereof.

[0108] Non-limiting examples of inorganic particles having a dielectric constant of about 5 or more include BaTiO3, Pb(Zr,Ti)O3(PZT), Pb 1-x La x Zr 1-y Ti y O3(PLZT), Pb(Mg 1 / 3 Nb 2 / 3 )O3-PbTiO3(PMN-PT), hafnia (HfO2), SrTiO3, SnO2, CeO2, MgO, NiO, CaO, ZnO, ZrO2, Y2O3, Al2O3, TiO 2,　 There are SiC, AlO(OH), Al2O3·H2O, or mixtures thereof.

[0109] The above inorganic particles having lithium ion transfer capability refer to inorganic particles that contain lithium elements but do not store lithium and have the function of transferring lithium ions. Non-limiting examples of inorganic particles having lithium ion transfer capability include lithium phosphate (Li3PO4), lithium titanium phosphate (Li). x Ti y (PO4)3, 0 <x<2, 0<y<3), 리튬알루미늄티타늄포스페이트(Li x Al y Ti z (PO4)3, 0 <x<2, 0<y<1, 0<z<3), 14Li2O-9Al2O3-38TiO2-39P2O 5　 (LiAlTiP) etc.x O y Series Glass (0) <x<4, 0<y<13), 리튬란탄티타네이트(Li x La y TiO3, 0 <x<2, 0<y<3), Li 3.25 Ge 0.25 P 0.75 S 4　 Lithium germanium thiophosphate (Li) such as x Ge y P z S w , 0 <x<4, 0<y<1, 0<z<1, 0<w<5), Li3N 등과 같은 리튬나이트라이드(Li x N y , 0 <x<4, 0<y<2), Li3PO4-Li2S-SiS 2　 SiS2 series glass (Li) such as x Si y S z , 0 <x<3, 0<y<2, 0<z<4), LiI-Li2S-P2S 5　 P2S5 series glass (Li) such as x P y S z , 0 <x<3, 0<y<3, 0<z<7) 또는 이들의 혼합물 등이 있다.

[0110] The thickness of the above-mentioned inorganic heat-resistant layer is not particularly limited, but may be about 1 ㎛ to 10 ㎛, or about 1.5 ㎛ to 6 ㎛, and the porosity of the above-mentioned inorganic heat-resistant layer is also not particularly limited, but may be about 35% to 65%.

[0111] In one embodiment of the present invention, the content of the inorganic particles may be about 80 wt% to 95 wt%, 85 wt% to 93 wt%, or 90 wt% to 92 wt% based on 100 wt% of the inorganic heat-resistant layer. When the content of the inorganic particles satisfies the above-described range, the inorganic heat-resistant layer may have a high density, and the porosity and resistance characteristics of the separator may be excellent.

[0112] In one embodiment of the present invention, the content of the binder polymer may be 5 wt% to 20 wt%, or 10 wt% to 15 wt%, based on 100 wt% of the inorganic heat-resistant layer. When the content of the binder polymer satisfies the above-described range, the heat resistance of the separator may be excellent without delamination of inorganic particles within the inorganic heat-resistant layer.

[0113]

[0114] Meanwhile, in the case where an inorganic heat-resistant layer is formed on the separator, an interlayer film may be further included on at least one of the first inorganic heat-resistant layer and the second inorganic heat-resistant layer. That is, an interlayer film may be included between the first inorganic heat-resistant layer and the second inorganic heat-resistant layer, an interlayer film may be included between the first inorganic heat-resistant layer and the second porous polymer substrate, and an interlayer film may be included between the second inorganic heat-resistant layer and the first porous polymer substrate.

[0115] In one embodiment of the present invention, depending on the content of the binder polymer in the inorganic heat-resistant layer, the binder polymer may be present inside the inorganic heat-resistant layer to bind the inorganic particles, while the binder may be present on the surface of the inorganic heat-resistant layer. In this case, it may be difficult to supply the first separator and the second separator separately, so in this case, an interlayer film may be further included on at least one of the first inorganic heat-resistant layer and the second inorganic heat-resistant layer, thereby facilitating the separation of the first separator and the second separator.

[0116] In one embodiment of the present invention, the adhesive film is also called a release film, and the adhesive film is not limited in type, but may be, for example, a PET film.

[0117]

[0118] <Method for manufacturing a membrane winding roll>

[0119] The present invention provides a method for manufacturing a membrane winding roll according to one embodiment.

[0120] According to one aspect of the present invention, the present invention provides a method for manufacturing a membrane winding roll, comprising: a step of introducing a first mixture of a first diluent and a first polymer resin into an extruder, followed by extrusion and cooling to obtain a first unstretched sheet; a step of introducing a second mixture of a second diluent and a second polymer resin into the extruder, followed by extrusion and cooling to obtain a second unstretched sheet; a step of laminating the first unstretched sheet and the second unstretched sheet to obtain an unstretched laminated sheet; a step of primarily stretching the unstretched laminated sheet in a first direction; a step of secondarily stretching the primarily stretched laminated sheet in a second direction; a step of extracting the diluent from the secondarily stretched laminated sheet to obtain a laminated separator in which a first separator and a second separator are laminated; and a step of winding the obtained laminated separator.

[0121]

[0122] Hereinafter, a method for manufacturing a membrane winding roll is described in detail.

[0123] First, a first mixture of a first diluent and a first polymer resin is introduced into an extruder, followed by extrusion and cooling to obtain a first unstretched sheet, and a second mixture of a second diluent and a second polymer resin is introduced into the extruder, followed by extrusion and cooling to obtain a second unstretched sheet.

[0124] In one embodiment of the present invention, the materials of the first polymer resin and the second polymer resin may each include polyethylene such as high-density polyethylene, linear low-density polyethylene, low-density polyethylene, ultra-high molecular weight polyethylene, polypropylene, polybutylene, polypentene, polyester, polyethyleneterephthalate, polybutyleneterephthalate, polyester, polyacetal, polyamide, polycarbonate, polyimide, polyetheretherketone, polyethersulfone, polyphenyleneoxide, polyphenylenesulfide, polyethylenenaphthalene, or a mixture of two or more thereof. The first polymer resin and the second polymer resin may each include polyethylene, such as high-density polyethylene, linear low-density polyethylene, low-density polyethylene, ultra-high molecular weight polyethylene, polypropylene, polybutylene, polypentene, or mixtures thereof.

[0125] In one embodiment of the present invention, the first and second diluents may each be diluents generally used in the manufacture of wet separation membranes, and examples thereof include liquid or solid paraffin oil, wax, soybean oil, phthalic acid esters such as dibutyl phthalate, dihexyl phthalate, and dioctyl phthalate; aromatic ethers such as diphenyl ether and benzyl ether; fatty acids having 10 to 20 carbon atoms such as palmitic acid, stearic acid, oleic acid, linoleic acid, and linolenic acid; fatty acid alcohols having 10 to 20 carbon atoms such as palmitic alcohol, stearic alcohol, and oleic alcohol; Palmitic acid mono-, di-, or triester, stearic acid mono-, di-, or triester, oleic acid mono-, di-, or triester, linoleic acid mono-, di-, or triester, etc., saturated and unsaturated fatty acids having 4 to 26 carbon atoms in the fatty acid group, or fatty acid esters in which one or more fatty acids in which the double bond of the unsaturated fatty acid is replaced by an epoxy group are ester-bonded with an alcohol having 1 to 8 hydroxyl groups and 1 to 10 carbon atoms; but are not limited thereto. The diluent may be used alone or as a mixture containing at least two kinds of the above-mentioned components.

[0126] In one embodiment of the present invention, the content of the first diluent or the second diluent may be added in a conventionally added content, and may be 100 to 350 parts by weight, or 125 to 300 parts by weight, or 150 to 250 parts by weight based on 100 parts by weight of each of the first mixture or the second mixture, but is not limited thereto.

[0127] In one embodiment of the present invention, the first mixture and the second mixture may further contain general additives for improving specific functions, such as an antioxidant, an initiator, a crosslinking agent, a crosslinking catalyst, a surfactant, a UV stabilizer, an antistatic agent, and a nucleating agent, in addition to a diluent.

[0128] In one embodiment of the present invention, the extruder may be a single-screw extruder or a twin-screw extruder, and a T-die is provided as a discharge unit. By using a T-die as a discharge unit, a separation membrane with excellent thickness uniformity can be obtained. After each of the first mixture and the second mixture is fed into the extruder, a molten composition can be obtained by melting and mixing the polymer resin at a high temperature.

[0129] Thereafter, the first and second mixtures, which are each molten, are extruded through an extruder equipped with the T-die, and then a general casting or calendaring method using water cooling or air cooling is used to obtain a first unstretched sheet and a second unstretched sheet in a sheet shape, respectively.

[0130] Meanwhile, as the extrudate is cooled through the above cooling process, phase separation of the polymer resin and the diluent may occur.

[0131]

[0132] Thereafter, the first unstretched sheet and the second unstretched sheet are laminated to obtain an unstretched laminated sheet. The first unstretched sheet and the second unstretched sheet may be physically overlapped and laminated.

[0133] In one embodiment of the present invention, the size of the first unstretched sheet and the size of the second unstretched sheet may be the same or different from each other.

[0134]

[0135] Thereafter, the above-mentioned unstretched laminated sheet is first stretched in the first direction, and the first-stretched laminated sheet is secondarily stretched in the second direction.

[0136] In one embodiment of the present invention, the first stretching and the second stretching can be performed sequentially or simultaneously, for example, in a roll manner or a tenter manner.

[0137] In one embodiment of the present invention, the first direction and the second direction may be the same or different from each other.

[0138] Additionally, in one embodiment of the present invention, the first direction and the second direction may each independently be a direction parallel to the machine direction (MD) or the transverse direction (TD).

[0139] In this specification, the 'machine direction' refers to a direction parallel to the direction of travel of the [extrusion->molding->stretching...] process in the manufacturing process of the membrane. The machine direction can be identified through the fiber orientation direction of the polymer of the membrane substrate, and the direction parallel to the fiber orientation direction is the machine direction.

[0140] Accordingly, the above-mentioned 'transverse direction' means a direction orthogonal to the machine direction. The above-mentioned transverse direction can also be identified as a direction orthogonal to the fiber orientation direction of the polymer of the membrane substrate.

[0141] In one embodiment of the present invention, the first direction may generally be a direction parallel to MD, and the second direction may be a direction parallel to TD, but the present invention is not limited thereto.

[0142] In one embodiment of the present invention, the first direction may be a direction parallel to the TD, and the second direction may be a direction parallel to the MD.

[0143] In one embodiment of the present invention, the stretching ratio of the first stretching and the second stretching may be, for example, 3 times or more, or 5 to 12 times in the machine direction or the transverse direction, respectively, and the total stretching ratio may be 20 to 120 times. When the stretching ratio satisfies the above numerical range, there may be advantageous effects in terms of thickness uniformity of the manufactured membrane substrate and balance of physical properties between the longitudinal and transverse directions, but the present invention is not limited thereto.

[0144] In one embodiment of the present invention, the stretching temperature may vary depending on the melting point of the polymer resin used, the concentration and type of the diluent, and the present invention is not limited thereto.

[0145]

[0146] Next, the diluent is extracted from the second-stretched laminated sheet to obtain a laminated separator in which the first separator and the second separator are laminated.

[0147] In one embodiment of the present invention, the diluent can be extracted using an organic solvent. The organic solvent is not particularly limited as long as it can extract the diluent. However, suitable solvents include methyl ethyl ketone, methylene chloride, hexane, or a mixture of two or more thereof, which have high extraction efficiency and rapid drying.

[0148] In one embodiment of the present invention, the extraction method may be any general solvent extraction method such as an immersion method, a solvent spray method, an ultrasonic method, etc., either individually or in combination. The content of the residual diluent after the extraction treatment may be, for example, 1 wt% or less based on 100 wt% of the obtained laminated membrane to be manufactured. If the content of the residual diluent exceeds 1 wt%, the physical properties deteriorate and the permeability of the membrane decreases. The content of the residual diluent may be affected by the extraction temperature and extraction time. In order to increase the solubility of the diluent and the organic solvent, a high extraction temperature is preferable, but considering the safety issue due to boiling of the organic solvent, it may be 40°C or lower. If the extraction temperature is lower than the freezing point of the diluent, the extraction efficiency is greatly reduced, so it must be higher than the freezing point of the diluent.

[0149]

[0150] In one embodiment of the present invention, the step of heat-setting the laminated separator may be further included. The heat-setting may mean applying heat to the separator to fix it, forcibly holding the porous membrane that is about to shrink, thereby removing residual stress.

[0151] In one embodiment of the present invention, the heat setting temperature may be, for example, about 120°C to 140°C or 125 to 135°C. If the heat setting temperature exceeds the upper limit, fracture of the porous polymer substrate may occur, and if it is below the lower limit, stress relaxation of the porous polymer substrate may be insufficient.

[0152]

[0153] Thereafter, the obtained laminated separator is wound to obtain a separator winding roll.

[0154]

[0155] In one embodiment of the present invention, the first mixture may further include a first initiator and a first crosslinking agent, the second mixture may further include a second initiator and a second crosslinking agent, and the step of crosslinking the laminated separator from which the diluent is extracted may further be included.

[0156]

[0157] In one embodiment of the present invention, when the first polymer resin and the second polymer resin are each polyolefin, any crosslinking agent commonly used in manufacturing polyolefin crosslinked separators may be used as the crosslinking agent. For example, the first crosslinking agent and the second crosslinking agent may each be, for example, an alkoxy silane compound containing a carbon-carbon double bond group that causes a silane crosslinking reaction. That is, the alkoxy silane compound containing a carbon-carbon double bond group is grafted onto the polyolefin by the carbon-carbon double bond group, and a crosslinking reaction proceeds by the alkoxy group, thereby crosslinking the polyolefin. Accordingly, the meltdown temperature of the separator can be increased.

[0158] The above carbon-carbon double bond group is a reactive group capable of grafting onto polyolefin as described above, and is a substituent having a double bond between two carbons. Examples thereof include a vinyl group, an acryloxy group, or a methacryloxy group.

[0159] In one embodiment of the present invention, the carbon-carbon double bond group-containing alkoxy silane compound may include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, (3-methacryloxypropyl)trimethoxysilane, (3-methacryloxypropyl)triethoxysilane, vinylmethyldimethoxysilane, vinyl-tris(2-methoxyethoxy)silane, vinylmethyldiethoxysilane, or a mixture of at least two or more thereof.

[0160] In one embodiment of the present invention, the content of the first cross-linking agent may be about 0.1 to 3.0 wt%, or 0.15 to 2.0 wt%, or 0.2 to 1.5 wt% based on 100 wt% of the first mixture.

[0161] In one embodiment of the present invention, the content of the second cross-linking agent may be about 0.1 to 3.0 wt%, or 0.15 to 2.0 wt%, or 0.2 to 1.5 wt% based on 100 wt% of the second mixture.

[0162] In one embodiment of the present invention, the first initiator and the second initiator can be used without limitation as long as they are initiators capable of generating radicals. The first initiator and the second initiator can be, for example, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane (DHBP), benzoyl peroxide, acetyl peroxide, dilauryl peroxide, di-tert-butyl peroxide, dicumyl peroxide, cumyl peroxide, hydrogen peroxide, potassium persulfate, or a combination thereof.

[0163] In one embodiment of the present invention, the content of the first initiator may be about 0.1 to 20 parts by weight, or 0.5 to 10 parts by weight, or 1 to 5 parts by weight based on 100% by weight of the first crosslinking agent.

[0164] In one embodiment of the present invention, the content of the second initiator may be about 0.1 to 20 parts by weight, or 0.5 to 10 parts by weight, or 1 to 5 parts by weight based on 100 wt% of the second crosslinking agent.

[0165] In one embodiment of the present invention, when the first mixture further includes a first initiator and a first crosslinking agent, and the second mixture further includes a second initiator and a second crosslinking agent, the laminated separator from which the diluent is extracted can be crosslinked after being heat-set.

[0166] In one embodiment of the present invention, the crosslinking may be a water crosslinking, and the water crosslinking may be performed at 60 to 100°C, 65 to 95°C, or 70 to 90°C. In a specific embodiment of the present invention, the water crosslinking may be performed at a humidity of 60 to 95% for 6 to 50 hours.

[0167]

[0168] According to another aspect of the present invention, a method for manufacturing a membrane winding roll of the present invention comprises the steps of: feeding a third mixture of a third diluent and a third polymer resin into an extruder, followed by extrusion and cooling to obtain a third unstretched sheet; feeding a fourth mixture of a fourth diluent and a fourth polymer resin into an extruder, followed by extrusion and cooling to obtain a fourth unstretched sheet; first stretching the third unstretched sheet and the fourth unstretched sheet in a first direction, respectively; second stretching the first-stretched third sheet and the fourth sheet in a second direction, respectively; extracting the third diluent and the fourth diluent from the second-stretched sheets, respectively, to obtain a third porous polymer substrate and a fourth porous polymer substrate; applying and drying a third inorganic heat-resistant layer-forming slurry containing third inorganic particles and a third binder polymer onto at least one surface of the obtained third porous polymer substrate, thereby forming a third inorganic heat-resistant layer; A step of forming a fourth inorganic heat-resistant layer by applying and drying a slurry for forming a fourth inorganic heat-resistant layer including fourth inorganic particles and a fourth binder polymer on at least one surface of the fourth porous polymer substrate obtained above; and a step of stacking and winding the third porous polymer substrate on which the third inorganic heat-resistant layer is formed and the fourth porous polymer substrate on which the fourth inorganic heat-resistant layer is formed.

[0169] Hereinafter, a method for manufacturing a membrane winding roll is described in detail.

[0170]

[0171] First, a third mixture of a third diluent and a third polymer resin is fed into an extruder, followed by extrusion and cooling to obtain a third unstretched sheet, and a fourth mixture of a fourth diluent and a fourth polymer resin is fed into an extruder, followed by extrusion and cooling to obtain a fourth unstretched sheet.

[0172] At this time, the third diluent and the fourth diluent are identical to the first diluent and the second diluent described above, respectively, and are substituted for the above.

[0173] In addition, the third polymer resin and the fourth polymer resin are identical to the first polymer resin and the second polymer resin described above, respectively, and replace the aforementioned ones.

[0174]

[0175] Thereafter, the third unstretched sheet and the fourth unstretched sheet are each first stretched in the first direction, and the first stretched third sheet and the fourth sheet are each second stretched in the second direction.

[0176] At this time, the extension step may be the same as described above.

[0177] Meanwhile, the stretching step may be performed by laminating the third unstretched sheet and the fourth unstretched sheet to obtain an unstretched laminated sheet and then stretching it.

[0178]

[0179] Thereafter, the third diluent and the fourth diluent are extracted from the second-stretched sheet, respectively, to obtain the third porous polymer substrate and the fourth porous polymer substrate. At this time, the third diluent and the fourth diluent are the same as the first diluent and the second diluent described above, respectively, and are substituted for them.

[0180]

[0181] In one embodiment of the present invention, the step of heat-setting the third porous polymer substrate and the fourth porous polymer substrate from which the diluent is extracted may be further included. In this case, the heat-setting step is replaced with the step described above.

[0182]

[0183] Thereafter, a slurry for forming a third inorganic heat-resistant layer, including third inorganic particles and a third binder polymer, is applied and dried on at least one surface of the obtained third porous polymer substrate to form a third inorganic heat-resistant layer, and a slurry for forming a fourth inorganic heat-resistant layer, including fourth inorganic particles and a fourth binder polymer, is applied and dried on at least one surface of the obtained fourth porous polymer substrate to form a fourth inorganic heat-resistant layer.

[0184] The third inorganic particle, the fourth inorganic particle, the third binder polymer, and the fourth binder polymer are substituted for those described above.

[0185] In one embodiment of the present invention, the third inorganic heat-resistant layer-forming slurry and the fourth inorganic heat-resistant layer-forming slurry (hereinafter also referred to as inorganic heat-resistant layer-forming slurry) each contain inorganic particles and a binder polymer in a dispersion medium.

[0186] In one embodiment of the present invention, the dispersion medium is an aqueous dispersion medium. The aqueous dispersion medium may be water or an aqueous dispersion medium containing water. In addition, when there are limitations on the drying speed and temperature, methanol, ethanol, isopropyl alcohol, etc. having 1 to 5 carbon atoms and having a boiling point lower than water may be used together. In the above manufacturing method, by using an aqueous dispersion medium, the particulate binder polymer is dispersed while maintaining its particle shape without dissolving in the dispersion medium.

[0187] Meanwhile, in one embodiment of the present invention, it is preferable that the slurry for forming the water-based inorganic heat-resistant layer and the slurry for forming the water-based adhesive layer are controlled so that the concentration of solids excluding the dispersion medium (or also referred to as the content of solids) has a range of 20 wt% to 50 wt%.

[0188] In one embodiment of the present invention, there is no limitation on the method of applying the slurry for forming the water-based inorganic heat-resistant layer onto at least one surface of the porous polymer substrate. For example, various methods may be used as the application method, such as dip coating, die coating, roll coating, comma coating, microgravure coating, doctor blade coating, reverse roll coating, Mayer Bar coating, direct metering coating, or a mixture thereof.

[0189] In one embodiment of the present invention, the drying method of the slurry for forming the water-based inorganic heat-resistant layer is not limited to a specific method, and for example, one or a combination of two or more of convection drying, hot air drying, ventilation drying, and natural drying methods may be applied. The drying method may be hot air drying.

[0190] In one embodiment of the present invention, the drying step may be performed at a temperature of 55°C to 68°C. When the temperature of the drying step satisfies the above-described range, limited inorganic particles may be arranged within the inorganic heat-resistant layer to provide better durability and mechanical strength.

[0191] In one embodiment of the present invention, the drying step may be performed for 10 to 120 seconds within the temperature range described above.

[0192]

[0193] Thereafter, the third porous polymer substrate having the third inorganic heat-resistant layer formed thereon and the fourth porous polymer substrate having the fourth inorganic heat-resistant layer formed thereon are laminated and wound.

[0194] In one embodiment of the present invention, the winding step may further include laminating a liner film on at least one of the third inorganic heat-resistant layer and the fourth inorganic heat-resistant layer, and then winding the film. In this case, the third liner film and the fourth liner film are of the same type as the first liner film and the second liner film described above, respectively, and are substituted for the first liner film and the second liner film described above.

[0195]

[0196] In one embodiment of the present invention, the third mixture may further include a third initiator and a third crosslinking agent, the fourth mixture may further include a fourth initiator and a fourth crosslinking agent, and the step of crosslinking the third porous polymer substrate and the fourth porous polymer substrate from which the diluent is extracted may be further included.

[0197] At this time, the third initiator and the fourth initiator are identical to the first and second initiators described above, respectively, and replace them.

[0198] At this time, the third cross-linking agent and the fourth cross-linking agent are identical to the first cross-linking agent and the second cross-linking agent described above, respectively, and replace them.

[0199]

[0200] Electrode assembly manufacturing device

[0201] The present invention provides an electrode assembly manufacturing device including the aforementioned separator winding roll.

[0202] An electrode assembly manufacturing device (100) according to one embodiment of the present invention may be configured to supply a first electrode (14), a first separator (11), a second electrode (15), and a second separator (12) in a roll-to-roll manner, sequentially stack them, and wind them in one direction, while the first separator (11) and the second separator (12) are wound in an overlapped manner on one roll and then unwound into individual sheets to supply them. That is, the electrode assembly manufacturing device (100) is configured to manufacture an electrode assembly using the above-mentioned overlapped and wound separator.

[0203] Fig. 3 schematically illustrates the structure of an electrode assembly manufacturing device (100) according to one embodiment of the present invention. Fig. 4 schematically illustrates the structure of an electrode assembly manufacturing device (100) according to another embodiment of the present invention. Fig. 5 schematically illustrates the structure of an electrode assembly manufacturing device (100) according to yet another embodiment of the present invention.

[0204] First, referring to FIG. 3, an electrode assembly manufacturing device (100) includes a membrane supply unit (110) that supplies two or more layers of membranes individually separated from a membrane winding roll (10) in which two or more layers of membranes are laminated and wound; a first electrode supply unit (120) that supplies a first electrode (14); a second electrode supply unit (130) that supplies a second electrode (15); and a winding unit (140) that laminates and winds the individually separated membranes between the first electrode (14) and the second electrode (15) and on an outer side of the first electrode (14) or the second electrode (15).

[0205] The separator supply unit (110), the first electrode supply unit (120), and the second electrode supply unit (130) may be configured to continuously supply the first separator (11), the second separator (12), the first electrode (14), and the second electrode (15) wound into a roll by unwinding them, respectively. The winding unit (140) may be configured to sequentially stack the first electrode (14), the first separator (11), the second electrode (15), and the second separator (12) and wind them in one direction to be wound into a roll. Therefore, the device may be configured in a roll-to-roll manner to enable a continuous process. In this case, the electrode assembly manufacturing device (100) of the present invention uses one separator supply unit (110), so that when the separator is exhausted, only one replacement of the separator winding roll (10) is required, thereby making maintenance advantageous. Since the separator supply unit (110) may include only one, the process structure of the electrode assembly manufacturing device (100) can be simplified. In addition, the paths of the cathode, anode, and separator in the electrode assembly manufacturing device (100) can be simplified compared to the prior art.

[0206] In one embodiment of the present invention, the winding unit (140) is a device for winding the first electrode (14), the second electrode (15), and the first and second separators (11, 12), and is also called a mandrel. The winding unit (140) may include a core and a motor for rotating the core. At this time, after the first electrode (14), the first and second separators (11, 12), and the second electrode (15) are supplied, the winding unit (140) rotates, and the first electrode (14), the second electrode (15), and the separators (11, 12) are pulled by the rotational force of the winding unit (140), and an electrode assembly may be manufactured.

[0207] In one embodiment of the present invention, the first electrode (14) may be a cathode and the second electrode (15) may be an anode, or the first electrode (14) may be an anode and the second electrode (15) may be a cathode.

[0208] The first electrode supply unit (120) supplies the first electrode (14) to the winding unit (140). For this purpose, the first electrode supply unit (120) may include a winding roll on which the first electrode (14) cut into a sheet shape is wound. The first electrode supply unit (120) may include other components such as a shaft or roller necessary for mounting and unwinding the winding roll. The second electrode supply unit (130) supplies the second electrode (15) to the winding unit (140). For this purpose, the second electrode supply unit (130) may include a winding roll on which the second electrode (15) cut into a sheet shape is wound. The second electrode supply unit (130) may include other components such as a shaft or roller necessary for mounting and unwinding the winding roll.

[0209] The membrane supply unit (110) may be configured to supply the first membrane (11) and the second membrane (12) that are wound and overlapped into a single roll by unwinding them into individual sheets. To this end, the membrane supply unit (110) may include the membrane take-up roll (10) according to the present invention as described above. The membrane supply unit (110) may include other components such as a shaft and a roller that are necessary to mount the membrane take-up roll (10) and unwind the membrane from the membrane take-up roll (10). As described above, the membrane take-up roll (10) includes the first membrane (11) and the second membrane (12), and the take-up unit (140) may sequentially stack and wind the first electrode (14), the first membrane (11), the second electrode (15), and the second membrane (12). Alternatively, the winding unit (140) may sequentially stack and wind the second separator (12), the first electrode (14), the first separator (11), and the second electrode (15).

[0210] As illustrated in FIG. 3, in the electrode assembly manufacturing device (100), a first separator (11) may be positioned between the first electrode (14) and the second electrode (15), and a second separator (12) may be positioned on the outside of the second electrode (15).

[0211] As another example, as illustrated in FIG. 4, in the electrode assembly manufacturing device (100), a first separator (11) may be positioned between the first electrode (14) and the second electrode (15), and a second separator (12) may be positioned on the outside of the first electrode (14). In other words, in the electrode assembly manufacturing device (100) of FIG. 3, the second separator (12) is positioned on the outside of the second electrode (15), whereas in the assembly manufacturing device (100) of FIG. 4, the second separator (12) is positioned on the outside of the first electrode (14).

[0212] In one embodiment of the present invention, as illustrated in FIG. 3 or FIG. 4, the electrode assembly manufacturing device (100) may further include at least one first guide roller (111) for supplying the first separator (11) supplied by unwinding the separator winding roll (10) between the first electrode (14) and the second electrode (15); and at least one second guide roller (112) for supplying the second separator (12) supplied by unwinding the separator winding roll (10) in a direction opposite to one surface of one of the first electrode (14) and the second electrode (15).

[0213] In one embodiment of the present invention, the path along which the first separation membrane (11) passes from the separation membrane supply unit (110) to the winding unit (140) is referred to as a first separation membrane supply path, and the first separation membrane supply path may refer to a path along which the first separation membrane (11) is unwound from the separation membrane supply unit (110) and moves to the winding unit (140) while wrapping around the outer periphery of the first guide roller (111). At this time, the first guide roller (111) may be positioned so that the first separation membrane (11) located in the first separation membrane supply path has tension.

[0214] In one embodiment of the present invention, the path along which the second separation membrane (12) passes from the separation membrane supply unit (110) to the winding unit (140) is referred to as a second separation membrane supply path, and the second separation membrane supply path may refer to a path along which the second separation membrane (12) is unwound from the separation membrane supply unit (110) and moves to the winding unit (140) through the outer periphery of the second guide roller (112). At this time, the second guide roller (112) may be positioned so that the second separation membrane (12) located in the second separation membrane supply path has tension.

[0215] In one embodiment of the present invention, the at least one second guide roller (112) may be arranged so that the second membrane supply path from the membrane supply unit (110) to the winding unit (140) bypasses the first electrode supply unit (120) or the second electrode supply unit (130).

[0216] For example, as illustrated in FIG. 3, at least one second guide roller (112) may be arranged so that the second membrane supply path from the membrane supply unit (110) to the winding unit (140) bypasses the second electrode supply unit (130).

[0217] In addition, as illustrated in FIG. 4, at least one second guide roller (112) may be arranged so that the second separation membrane supply path from the separation membrane supply unit (110) to the winding unit (140) bypasses the first electrode supply unit (120).

[0218] In addition, referring to FIGS. 3 and 4, the electrode assembly manufacturing device (100) may further include a first electrode guide roller (121) so that the first electrode (14) is supplied from the first electrode supply unit (120) to the winding unit (140), and may further include a second electrode guide roller (131) so that the second electrode (15) is supplied from the second electrode supply unit (130) to the winding unit (140). The first electrode guide roller (121) and the second electrode guide roller (131) may apply tension to the first electrode (14) and the second electrode (15) being wound, thereby reducing defects in the jelly-roll type electrode assembly.

[0219] As previously described with reference to FIG. 1, the winding length of the first separator (11) and the winding length of the second separator (12) may be the same, or the winding length of the second separator (12) may be longer than the winding length of the first separator (11).

[0220] In one embodiment of the present invention, when the winding length of the second separator (12) is longer than the winding length of the first separator (11), the difference between the winding length of the second separator (12) and the winding length of the first separator (11) may be equal to or longer than the difference between the length of the second separator supply path and the length of the first separator supply path. In this case, the first separator (11) and the second separator (12) may be included in the same content in the jelly-roll-type electrode assembly wound by the winding unit (140), and the manufacturing of the electrode assembly may not be interrupted due to a shortage of the second separator (12).

[0221] Meanwhile, in one embodiment of the present invention, the length of the first membrane supply path and the second membrane supply path may be different when the membrane supply unit (110) is unwound when the electrode assembly manufacturing device (100) is in operation, but the length of the first membrane supply path and the second membrane supply path may be defined as follows. For example, the length from the point where the first membrane (11) comes into contact with (is perpendicular to) the membrane winding roll (10) to the part where the first membrane (11) comes into contact with (is perpendicular to) the electrode assembly manufactured in the winding unit (140) may be the length of the first membrane supply path, and in this case, the first guide roller (111) must be positioned to come into contact with the first membrane (11), each of the membrane winding rolls (10) and the electrode assembly. The length of the second membrane supply path may also be defined similarly.

[0222] In one embodiment of the present invention, the electrode assembly manufacturing device (100) may further include at least one tension roller (150) to apply tension when the first electrode (14), the second electrode (15), and the separator (11, 12) are supplied from each of the supply units (110, 120, 130) to the winding unit (140). When the tension roller (150) is further included, the first electrode (14), the first separator (11), the second electrode (15), and the second separator (12) can be stacked without folding, thereby improving the manufacturing yield of the electrode assembly and reducing the defect rate.

[0223] Meanwhile, in one embodiment of the present invention, the positions of the membrane supply unit (110), the first electrode supply unit (120), and the second electrode supply unit (130) in the electrode assembly manufacturing device (100) may be freely modified depending on the intended use. For example, as shown in FIG. 5, the first electrode supply unit (120) and the second electrode supply unit (130) may be positioned symmetrically with respect to the winding unit (140).

[0224]

[0225] <Method for manufacturing electrode assembly>

[0226] The present invention provides a method for manufacturing an electrode assembly. The electrode assembly manufactured in the present invention is a jelly-roll type electrode assembly.

[0227] The method for manufacturing an electrode assembly of the present invention includes a step of sequentially stacking and winding a first electrode, a first separator, a second electrode, and a second separator by supplying them in a roll-to-roll manner, wherein the first separator and the second separator may be supplied by unwinding them into individual sheets after being wound in an overlapping manner on a single roll. In other words, the electrode assembly is manufactured using overlapping and wound separators.

[0228] This electrode assembly manufacturing method can be performed using the electrode assembly manufacturing device (100) illustrated and described above in FIGS. 3 to 5.

[0229] Referring to FIG. 6, a method for manufacturing an electrode assembly according to an embodiment of the present invention includes: (S10) a step of individually separating two or more layers of separators from a separator winding roll in which two or more layers of separators are laminated and wound; (S20) a step of supplying the separated individual separators; (S30) a step of supplying a first electrode; (S40) a step of supplying a second electrode; and (S50) a step of respectively laminating and winding the individually separated separators between the first electrode and the second electrode and on an outer side of the first electrode or the second electrode.

[0230] This method can also be performed using the electrode assembly manufacturing device (100) illustrated and described in FIGS. 3 to 5. The electrode assembly manufacturing method of the present invention can simplify the process procedure by using a membrane winding roll (10) in which two or more layers of membranes are laminated and wound. When the membrane is exhausted, a continuous process is possible by replacing the membrane winding roll (10) once.

[0231] The step of separating the two or more layers of separation membranes into individual pieces from the separation membrane winding roll (10) above (S10) may be a step of manually separating the two or more layers of separation membranes into individual pieces by a worker. In addition, the step of supplying the separated individual separation membranes above (S20) may be a step of manually hanging the separated separation membranes on a winding unit (140) by a worker.

[0232] In one embodiment of the present invention, steps (S20) to (S50) may be performed simultaneously after step (S10) is performed. That is, in the electrode assembly manufacturing method of the present invention, steps (S20), (S30), and (S40) of separating two or more layers of separators individually from a separator winding roll (10) and then supplying them to a winding unit (140), and step (S50) of stacking and winding the individually separated separators between the supplied first electrode (14) and second electrode (15) and on an outer side of the first electrode (14) or the second electrode (15), respectively, may be performed simultaneously.

[0233] In one embodiment of the present invention, the two or more layers of separators include a first separator (11) and a second separator (12), and the step (S50) may be to sequentially stack and wind the first electrode (14), the first separator (11), the second electrode (15), and the second separator (12), or to sequentially stack and wind the second separator (12), the first electrode (14), the first separator (11), and the second electrode (15).

[0234] As described above, the winding length of the first separator (11) and the winding length of the second separator (12) may be the same, or the winding length of the second separator (12) may be longer than the winding length of the first separator (11). In this case, the jelly-roll-shaped electrode assembly wound by the winding unit (140) may include the same content of the first separator (11) and the second separator (12), and the manufacturing of the electrode assembly may not be interrupted due to a shortage of the second separator (12).

[0235] According to one embodiment, the step (S10) is performed using the aforementioned membrane supply unit (110), and the step (S50) is performed using the aforementioned winding unit (140). At this time, a membrane winding roll (10) having a winding length of the second membrane (12) longer than a winding length of the first membrane (11) is used, so that the difference between the winding length of the second membrane (12) and the winding length of the first membrane (11) may be equal to or longer than the difference between the length of the second membrane supply path and the length of the first membrane supply path. In this case, the jelly-roll-type electrode assembly wound by the winding unit (140) may include the same content of the first membrane (11) and the second membrane (12), and the manufacturing of the electrode assembly may not be interrupted due to a lack of the second membrane (12).

[0236]

[0237] Hereinafter, the present invention will be described in more detail through examples, but the following examples are intended to illustrate the present invention, and the scope of the present invention is not limited to these examples.

[0238] Example

[0239] Liquid paraffin oil (Kukdong Yuhwa, LP 350P, 68 cSt) as the first diluent and polyethylene resin (Daehan Yuhwa, VH 035) with a weight average molecular weight of 600,000 as the first polymer resin were mixed in a ratio of 3:7 and fed into an extruder equipped with a T-die. At this time, the conveying, mixing, and extrusion were controlled at a temperature of 210°C, and the extrusion speed was controlled at 0.37 m / min. The composition passing through the extruder was passed through a cooling casting roll maintained at 45°C to produce a first unstretched sheet.

[0240] At the same time, liquid paraffin oil (Kukdong Oil & Chemical, LP 350P, 68 cSt) as a second diluent and polyethylene resin (Daehan Oil & Chemical, VH035) with a weight average molecular weight of 600,000 as a second polymer resin were mixed in a ratio of 3:7 and fed into an extruder equipped with a T-die. At this time, the conveying, mixing, and extrusion were controlled at a temperature of 210°C, and the extrusion speed was controlled at 0.37 m / min. The composition passing through the extruder was passed through a cooling casting roll maintained at 45°C to produce a second unstretched sheet.

[0241] The first unstretched sheet and the second unstretched sheet were laminated to manufacture an unstretched laminated sheet.

[0242] The above unstretched laminated sheet was biaxially stretched using a tenter-type sequential stretching machine for MD stretching (longitudinal stretching) and TD stretching (transverse stretching), and the diluent was extracted to manufacture a laminated separator. The MD stretching ratio was 5 times, and the TD stretching ratio was 6 times in both cases. The stretching temperature was 113°C for MD and 121°C for TD. The diluent was extracted using a methylene chloride / water mixture solution, and the extraction speed was 2 m / min.

[0243] The above laminated separator was heat-set at 129°C under conditions of stretching to 140% of its initial width and then relaxing to 120%. At this time, the heat-setting speed was 4 m / min, the thickness of the first and second separators constituting the laminated separator was 10.0 μm, and the winding length was 2,000 m.

[0244] The laminated separator obtained above was wound in one direction to manufacture a separator winding roll.

[0245]

[0246] Experimental example

[0247] Among the membrane winding rolls manufactured in the above example, the first and second membranes were separated and the air permeability and resistance characteristics were measured, which are shown in Table 1 below.

[0248] Air permeability (sec / 100ml) Resistance characteristics [ohm] 1st membrane 620.38 2nd membrane 630.38

[0249] The first and second separators manufactured according to the example had substantially the same air permeability and resistance characteristics.

[0250]

[0251] Measurement of air permeability

[0252] The separation membrane of the example was measured using a Gurley-type air permeability meter according to JIS P-8117. At this time, the time for 100 ml of air to pass through a 28.6 mm diameter and 645 mm2 area was measured.

[0253] Resistance characteristic measurement

[0254] The separator manufactured in the example was impregnated with an electrolyte (ethylene carbonate (EC): diethyl carbonate (DEC) = 3:7, LiPF6 1.0M), and then the AC resistance was measured, and the results are shown in Table 1 below. At this time, the AC resistance is the value measured at 1 kHz using EIS (Ametek).

[0255]

[0256] Although the present invention has been described above with reference to limited embodiments and drawings, the present invention is not limited thereto, and it is obvious that various modifications and variations are possible within the scope of the technical idea of ​​the present invention and the equivalent scope of the patent claims to be described below by a person having ordinary skill in the art to which the present invention pertains.

Claims

A membrane winding roll in which 1.2 or more layers of membranes are laminated and wound.

2. In claim 1, The above two or more layers of separation membranes include a first separation membrane and a second separation membrane, A membrane winding roll, characterized in that the winding length of the second membrane is longer than the winding length of the first membrane.

3. In claim 1, The above two or more layers of separation membranes include a first separation membrane and a second separation membrane, A membrane winding roll characterized in that one of the winding ends of the first membrane and the second membrane is wound so as to extend beyond the other, and is unwound before the other during unwinding.

4. In claim 1, The above two or more layers of separation membranes include a first separation membrane and a second separation membrane, The first separator comprises a first porous polymer substrate and a first inorganic heat-resistant layer comprising first inorganic particles and a first binder polymer on at least one surface of the first porous polymer substrate, A membrane winding roll, characterized in that the second membrane comprises a second porous polymer substrate and a second inorganic heat-resistant layer comprising second inorganic particles and a second binder polymer on at least one surface of the second porous polymer substrate.

5. In claim 4, A membrane winding roll characterized in that it further includes a sealing film on at least one of the first inorganic heat-resistant layer and the second inorganic heat-resistant layer.

6. A method for manufacturing a membrane winding roll, A step of introducing a first mixture of a first diluent and a first polymer resin into an extruder, then extruding and cooling to obtain a first unstretched sheet; A step of introducing a second mixture of a second diluent and a second polymer resin into an extruder, and then extruding and cooling to obtain a second unstretched sheet; A step of laminating the first unstretched sheet and the second unstretched sheet to obtain an unstretched laminated sheet; A step of first stretching the above-mentioned unstretched laminated sheet in a first direction to obtain a first laminated laminated sheet; A step of secondarily stretching the first-stretched laminated sheet in a second direction to obtain a second-stretched laminated sheet; A step of extracting the first diluent and the second diluent from the second-stretched laminated sheet to obtain a laminated separator in which the first separator and the second separator are laminated; and A method for manufacturing a membrane winding roll, characterized by including a step of winding the obtained laminated membrane.

7. In claim 6, A method for manufacturing a membrane winding roll, characterized in that it further includes a step of opening and fixing the laminated membrane.

8. In claim 6, The first mixture further comprises a first initiator and a first crosslinking agent, The second mixture further comprises a second initiator and a second crosslinking agent, A method for manufacturing a membrane winding roll, characterized in that it further comprises a step of cross-linking the laminated membrane from which the first diluent and the second diluent are extracted.

9. A method for manufacturing a membrane winding roll, A step of introducing a third mixture of a third diluent and a third polymer resin into an extruder, and then extruding and cooling to obtain a third unstretched sheet; A step of introducing a fourth mixture of a fourth diluent and a fourth polymer resin into an extruder, and then extruding and cooling to obtain a fourth unstretched sheet; A step of first stretching the third unstretched sheet and the fourth unstretched sheet in the first direction, respectively, to obtain first-stretched third sheets and fourth sheets; A step of secondarily stretching the first-stretched third sheet and fourth sheet in the second direction to obtain second-stretched third sheet and fourth sheet; A step of extracting the third diluent and the fourth diluent from the second-extended third sheet and fourth sheet, respectively, to obtain a third porous polymer substrate and a fourth porous polymer substrate; A step of forming a third inorganic heat-resistant layer by applying and drying a slurry for forming a third inorganic heat-resistant layer including third inorganic particles and a third binder polymer on at least one surface of the third porous polymer substrate obtained above; A step of forming a fourth inorganic heat-resistant layer by applying and drying a slurry for forming a fourth inorganic heat-resistant layer including fourth inorganic particles and fourth binder polymer on at least one surface of the fourth porous polymer substrate obtained above; and A method for manufacturing a membrane winding roll, comprising the step of stacking and winding a third porous polymer substrate having a third inorganic heat-resistant layer formed thereon and a fourth porous polymer substrate having a fourth inorganic heat-resistant layer formed thereon.

10. In claim 9, A method for manufacturing a membrane take-up roll, characterized in that it further includes a step of heat-fixing the third porous polymer substrate and the fourth porous polymer substrate from which the third diluent and the fourth diluent are extracted.

11. In claim 9, The third mixture further comprises a third initiator and a third crosslinker, The fourth mixture further comprises a fourth initiator and a fourth crosslinker, A method for manufacturing a membrane winding roll, characterized in that it further includes a step of crosslinking the third porous polymer substrate and the fourth porous polymer substrate from which the third diluent and the fourth diluent are extracted.

12. In claim 9, A method for manufacturing a membrane winding roll, characterized in that the winding step further comprises stacking an interlayer film on at least one of the third inorganic heat-resistant layer and the fourth inorganic heat-resistant layer, and then winding. A membrane winding roll in which 13.2 or more layers of membranes are laminated and wound; A membrane supply unit that individually separates and supplies two or more layers of membrane from the membrane winding roll; A first electrode supply unit supplying a first electrode; a second electrode supply unit supplying a second electrode; and An electrode assembly manufacturing device characterized by including a winding unit that laminates and winds the individually separated separators between the first electrode and the second electrode and on an outer side of the first electrode or the second electrode.

14. In claim 13, The two or more layers of separation membranes laminated on the above separation membrane winding roll include a first separation membrane and a second separation membrane, An electrode assembly manufacturing device, characterized in that the winding length of the second separator is longer than the winding length of the first separator.

15. In claim 13, The two or more layers of separation membranes laminated on the above separation membrane winding roll include a first separation membrane and a second separation membrane, An electrode assembly manufacturing device, characterized in that one of the winding ends of the first separator and the second separator is wound so as to extend beyond the other, and is unwound before the other during unwinding.

16. In claim 13, The two or more layers of separation membranes laminated on the above separation membrane winding roll include a first separation membrane and a second separation membrane, An electrode assembly manufacturing device characterized in that the above-mentioned winding part sequentially laminates and winds the first electrode, the first separator, the second electrode, and the second separator.

17. In claim 16, At least one first guide roller for supplying the first separator, which is supplied by unwinding the separator winding roll, between the first electrode and the second electrode; and An electrode assembly manufacturing device characterized by comprising at least one second guide roller for supplying the second separator, which is supplied by unwinding the separator winding roll, in a direction opposite to one surface of one of the first electrode and the second electrode.

18. In claim 17, An electrode assembly manufacturing device, characterized in that at least one second guide roller is arranged so that a second membrane supply path from the membrane supply unit to the winding unit bypasses the first electrode supply unit or the second electrode supply unit.

19. In claim 16, An electrode assembly manufacturing device, characterized in that the winding length of the second separator is longer than the winding length of the first separator.

20. In claim 16, The winding length of the second separator is longer than the winding length of the first separator, An electrode assembly manufacturing device, characterized in that the difference between the winding length of the second separator and the winding length of the first separator is equal to or longer than the difference between the length of the second separator supply path from the separator supply unit to the winding unit and the length of the first separator supply path from the separator supply unit to the winding unit. A step of individually separating two or more layers of separation membranes from a separation membrane winding roll in which 21.2 or more layers of separation membranes are laminated and wound; A step of supplying the separated individual separation membranes; Step of supplying the first electrode; a step of supplying a second electrode; and A method for manufacturing an electrode assembly, characterized by including a step of laminating and winding individually separated separators between the first electrode and the second electrode and on an outer side of the first electrode or the second electrode.

22. In claim 21, A method for manufacturing an electrode assembly, characterized in that the steps of supplying the separator, the step of supplying the first electrode, the step of supplying the second electrode, and the step of stacking and winding the separator respectively are performed simultaneously after the step of separating the two or more layers of separators individually is performed.

23. In claim 21, The above two or more layers of separation membranes include a first separation membrane and a second separation membrane, A method for manufacturing an electrode assembly, characterized in that the step of laminating and winding the above separators is to sequentially laminate and wind the first electrode, the first separator, the second electrode, and the second separator.

24. In claim 23, A method for manufacturing an electrode assembly, characterized in that the winding length of the second separator is longer than the winding length of the first separator.

25. In claim 23, The step of individually separating the two or more layers of separation membranes from the separation membrane winding roll is performed using a separation membrane supply unit, and the step of individually stacking and winding the separated separation membranes is performed using a winding unit. The winding length of the second separator is longer than the winding length of the first separator, A method for manufacturing an electrode assembly, characterized in that the difference between the winding length of the second separator and the winding length of the first separator is equal to or longer than the difference between the length of the second separator supply path from the separator supply unit to the winding unit and the length of the first separator supply path from the separator supply unit to the winding unit.

26. A method for manufacturing an electrode assembly, comprising a step of sequentially stacking and winding in one direction a first electrode, a first separator, a second electrode, and a second separator supplied in a roll-to-roll manner, wherein the first separator and the second separator are wound in an overlapped manner on one roll and then supplied by unwinding them into individual sheets.

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