KR102579153B1 - Assembly manufacturing equipment and method for electrode assembly - Google Patents

Abstract

The present invention relates to an electrode assembly manufacturing apparatus including a stack table, a separator supply unit, a first electrode supply unit, a second electrode supply unit, and a side sealing unit. On the stack table, a first electrode, a second electrode, and a separator between the first electrode and the second electrode are stacked. The separator supply unit is configured to supply a separator to the stack table. The first electrode supply unit is configured to stack the first electrode on the cross section of the separator on the stack table. The second electrode supply unit stacks the second electrode on another end surface of the separator on the first electrode. The side sealing unit heats at least one side of the stack.

Description

Electrode assembly manufacturing device and manufacturing method {ASSEMBLY MANUFACTURING EQUIPMENT AND METHOD FOR ELECTRODE ASSEMBLY}

This application is based on the filing date of Korean Patent Application No. 10-2021-0090590 filed with the Korea Intellectual Property Office on July 9, 2021, and Korean Patent Application No. 10-2021-0090591 filed with the Korea Intellectual Property Office on July 9, 2021. Benefits are claimed, the entire contents of which are incorporated into this specification.

The present invention relates to an electrode assembly manufacturing apparatus and manufacturing method. Specifically, the present invention relates to an electrode assembly manufacturing apparatus and manufacturing method that increases the electrode density of the electrode assembly by reducing the size of the separator included in the electrode assembly.

Unlike primary batteries, secondary batteries can be recharged and have been extensively researched and developed in recent years due to their small size and high capacity. As technology development and demand for mobile devices increase, the demand for secondary batteries as an energy source is rapidly increasing.

Secondary batteries are classified into coin-shaped batteries, cylindrical batteries, square-shaped batteries, and pouch-shaped batteries, depending on the shape of the battery case. In a secondary battery, the electrode assembly mounted inside the battery case is a power generating element capable of charging and discharging consisting of a stacked structure of electrodes and a separator.

The electrode assembly is a jelly-roll type that is wound with a separator interposed between a sheet-like positive and negative electrode coated with an active material, and a laminate type in which multiple positive and negative electrodes are stacked sequentially with a separator interposed. , and the laminated type can be roughly classified into the laminated and folded type in which unit cells of the laminated type are wound with a long length of separation film.

In the conventional process of manufacturing a laminate and folding type electrode assembly, the electrode assembly was manufactured by heating and pressurizing a laminate of electrodes and a separator to adhere the electrode and the separator. At this time, the electrode assembly had a problem in which the separator was folded and the electrode was exposed to the outside.

In order to solve this problem of the conventional electrode assembly, the electrode and separator were heated and stacked, and each layer was pressed and bonded at the same time as stacking, and the separator wrapped around the outermost layer of the electrode and separator laminate to manufacture the electrode assembly. did.

However, in the electrode assembly, a space is formed between the separator located on the side of the electrode assembly and the electrode at the position facing the separator located on the side of the electrode assembly due to the separator surrounding the outermost layer of the laminate, so that the separator on the side of the electrode assembly has wrinkles. Therefore, a problem occurred in which the energy density of the electrode assembly was reduced.

Therefore, measures are needed for the space formed between the separator side and the electrode assembly side.

Korean Patent Publication No. 10-2020-0023854

The present invention provides an electrode assembly manufacturing apparatus and method for manufacturing an electrode assembly that can be configured to manufacture an electrode assembly with a reduced area compared to a conventional electrode assembly. In particular, the width of the electrode assembly can be reduced by heating and pressurizing the laminate in which the first electrode, the second electrode, and the separator between the first electrode and the second electrode are stacked, thereby shrinking the electrode assembly compared to the conventional electrode assembly. .

One embodiment of the present invention is an electrode assembly manufacturing apparatus for manufacturing a laminate including a first electrode, a second electrode, and a cross section of a separator between the first electrode and the second electrode, which supports the laminate. stack table; a separator supply unit that supplies a portion of the separator to the stack table; a first electrode supply unit that stacks the first electrode on the separator supported on the stack table; a second electrode supply unit configured to stack the second electrode on the separator supported by the stack table, and a separate part that heats at least one side of the stack to cover a portion separated from the end surface of the separator or a side of the stack. An electrode assembly manufacturing apparatus including a side sealing portion for bonding any one of the separators to a side of the laminate is provided.

One embodiment of the present invention provides an electrode assembly manufacturing apparatus in which the side sealing part includes a pair of heating bars, and the pair of heating bars move in directions facing each other and press the side of the laminate.

One embodiment of the present invention provides an electrode assembly manufacturing apparatus further including a press unit. In one embodiment of the present invention, the press unit provides an electrode assembly manufacturing apparatus that heats the laminate while compressing the laminate. In one embodiment of the present invention, the press unit provides an electrode assembly manufacturing apparatus that compresses and simultaneously heats the laminate. In one embodiment of the present invention, the press unit can heat the laminate before compressing it, and in another embodiment, the press unit heats the laminate before and during compression of the laminate. do.

One embodiment of the present invention provides an electrode assembly manufacturing apparatus in which the side sealing unit presses the laminate in a direction perpendicular to the pressing direction of the press unit.

In one embodiment of the present invention, the press unit may include a pair of pressing blocks. The pair of pressurizing blocks may face each other. An electrode assembly manufacturing apparatus is provided in which the pair of pressure blocks are moved toward each other to compress the upper and lower surfaces of the stack facing each other.

In one embodiment of the present invention, the pair of pressure blocks each include a pressure surface, the pressure surface is in contact with a surface facing the laminate, and when the pressure surface compresses the laminate, the lamination An electrode assembly manufacturing apparatus is provided wherein the surface facing the water is provided as a flat surface.

One embodiment of the present invention provides an electrode assembly manufacturing apparatus in which the press unit includes a press heater that heats a pair of pressing blocks.

One embodiment of the present invention provides an electrode assembly manufacturing apparatus in which a pair of pressure blocks of the press unit each include a flat pressure surface, and the pressure surface of the pressure block is longer than the width and length of the laminate. do.

In one embodiment of the present invention, the first electrode supply unit temporarily fixes a first electrode seating table and the first electrode for seating the first electrode before the first electrode is stacked on the stack table, and the first electrode and a first transfer head that transfers the first electrode to the stack table during a process on the stack table while temporarily fixed to the electrode seating table, wherein the first transfer head transfers the first electrode to the first electrode. An electrode assembly manufacturing apparatus is provided, comprising a first suction head configured to suction the first electrode for fixation to the head. In one embodiment of the present invention, the second electrode supply unit temporarily fixes a second electrode seating table and the second electrode for seating the second electrode before the second electrode is stacked on the stack table, and the second electrode and a second transfer head that transfers the second electrode to the stack table during a process on the stack table while temporarily fixed to the electrode seating table, wherein the second transfer head transfers the second electrode to the second electrode. An electrode assembly manufacturing apparatus is provided, comprising a second suction head configured to suction the second electrode for fixation to the head. One embodiment of the present invention provides an electrode assembly manufacturing apparatus in which the first transfer head and the second transfer head each include a vacuum device for temporarily fixing the first electrode and the second electrode.

One embodiment of the present invention further includes a rotating part that rotates the stack table, the first electrode supply part is provided on one side of the rotating part, and the second electrode supply part is provided on the other side opposite to one side of the rotating part, , the rotation unit rotates the stack table to the first side so that the stack table faces the first transfer head when the first electrode is stacked, and faces the second transfer head when the second electrode is stacked. An electrode assembly manufacturing apparatus is provided that rotates the stack table to the second side so as to do so.

One embodiment of the present invention provides an electrode assembly manufacturing apparatus in which the rotation unit alternately rotates the stack table in the direction of the first electrode supply unit and the direction of the second electrode supply unit.

Another embodiment of the present invention is an electrode assembly manufacturing method for manufacturing a laminate, in which a first electrode, a separator, and a second electrode are supplied and stacked, and the separator is disposed between the first electrode and the second electrode. Providing a method for manufacturing an electrode assembly comprising manufacturing the laminate of a first electrode and a second electrode and bonding the first electrode and the second electrode to the separator by heating at least one side of the laminate. do.

Another embodiment of the present invention is that the step of bonding the first electrode and the second electrode to the separator is pressing at least one side of the laminate for 10 seconds or less at a temperature of 100 ° C. to 200 ° C. A method for manufacturing an electrode assembly is provided.

Another embodiment of the present invention provides a method of manufacturing an electrode assembly further comprising pressing the laminate in the direction in which the laminate is laminated. Another embodiment of the present invention provides a method for manufacturing an electrode assembly further comprising the step of heating the laminate. Another embodiment of the present invention provides a method of manufacturing an electrode assembly in which the laminate is heated before and simultaneously with being compressed, or before and simultaneously with the laminate being compressed. Another embodiment of the present invention provides a method of manufacturing an electrode assembly in which the press unit compresses and simultaneously heats the laminate. In another embodiment of the present invention, the press unit may heat the laminate before compressing the laminate, and in another embodiment, the press unit may heat the laminate before and during compression of the laminate. provides.

Another embodiment of the present invention provides a method of manufacturing an electrode assembly in which the step of bonding the first electrode and the second electrode to the separator compresses at least one side of the laminate with a pressure of 0.1 to 1.5 MPa. .

According to the electrode assembly manufacturing apparatus and method of the present invention, the electrode assembly is shrunk and the area of the electrode assembly is reduced by heating and pressing a laminate in which the first electrode, the separator, and the second electrode are alternately stacked. Electrode density and energy density can be increased. In one embodiment, the width of the stacked components of the electrode assembly can be reduced when shrinking the electrode assembly. In one embodiment, the width of the stack may be reduced by heating the stack, which may include first and second electrodes and a separator between the first and second electrodes.

In one embodiment according to any of the foregoing, the electrode assembly may be manufactured with dimensions corresponding to the inner space of a pouch, for example, the inner space of a can for use in a pouch-type battery or for use in a cylindrical battery. As such, the size of the pouch or can can be easily varied as desired without concern for manufacturability of the electrode assembly.

1 is a cross-sectional view showing an electrode assembly according to an exemplary embodiment of the present invention.
FIG. 2 is a perspective view showing a stack of the electrode assemblies of FIG. 1.
Figure 3 is a plan view showing an electrode assembly manufacturing apparatus according to an exemplary embodiment of the present invention.
Figure 4 is a front view showing the electrode assembly manufacturing apparatus of Figure 3.
FIG. 5 is a cross-sectional view of the electrode assembly within the side sealing portion of the electrode assembly manufacturing apparatus of FIG. 3 according to an exemplary embodiment of the present invention.
Figure 6 is a process flow diagram of an electrode assembly manufacturing process according to an exemplary embodiment of the present invention.
FIG. 7 is an enlarged cross-sectional photograph of the electrode assembly roughly located along line A-A' of the electrode assembly according to FIG. 1 taken with an optical microscope.
Figure 8 is an enlarged cross-sectional photograph of the electrode assembly taken with an optical microscope after cutting the cross-sections of Comparative Examples 1 and 2, as further described in the present invention.
Figure 9 is a photograph of the electrode assembly according to Comparative Example 3.

The detailed description of the present invention is intended to completely explain the present invention to those skilled in the art. Throughout the specification, when a part is said to “include” a certain component or is “characterized” by a certain structure and shape, this means excluding other components or excluding other structures and shapes unless specifically stated to the contrary. It does not mean that it does, but that it can include other components, structures, and shapes.

Since the present invention can be modified in various ways and can have various embodiments, specific embodiments will be presented and explained in detail in the detailed description. However, this is not intended to limit the content of the invention by examples, and should be understood to include all transformations, equivalents, and substitutes included in the spirit and technical scope of the present invention.

Hereinafter, the present invention will be described in detail with reference to the drawings. However, the drawings are for illustrating the present invention, and the scope of the present invention is not limited by the drawings.

Referring to FIGS. 1 and 2 , the electrode assembly may include a stack S and a second separator 5 surrounding the stack S.

As shown, in the stack S, the first electrodes 1 and the second electrodes 2 may be alternately disposed between the stacked portions 4a of the first separator 4. As further shown, the first separator 4 may be folded in a zigzag manner to form the stacked portion 4a.

3 to 5, the electrode assembly manufacturing apparatus 100 includes a stack table 10, a separator supply unit 20, a first electrode supply unit 30, a second electrode supply unit 40, and a side sealing unit 60. Includes.

The stack table 10 may have one support surface in which the first electrode 1, the stacked portion of the first separator 4, and the second electrode 2 are stacked in that order. The laminate (S) in which the first electrode 1, the second electrode 2, and the laminated portion of the first separator 4 located between the first and second electrodes is laminated, the first electrode 1, the laminated portion ( 4a) and the second electrode 2. The first separator 4 may be folded in a zigzag manner to form the stacked portion 4a and the folded portion 4b on the opposite side of each stacked portion 4a. In this way, the stack 4a of the first separator 4 can be disposed between each electrode of the first electrode 1 and each electrode of the second electrode 2 in the stack S. .

The stack table 10 is provided so that the first electrode 1 is placed on each stacked portion 4a of the first separator 4 supported by the stack table 10 and on the stacked portion 4a of the electrode and separator that are linearly stacked. A stacked portion 4a of the first separator 4 supported by the stack table 10 and a line-stacked electrode that can be rotated in one direction toward each of the first electrodes 1 supplied to be stacked, and It can rotate in one direction and in the other direction opposite to each of the supplied second electrodes 2 so that the second electrodes 2 can be stacked on each of the stacked portions 4a of the separator. Accordingly, the electrode assembly manufacturing apparatus 100 may further include a rotating part (not shown) that rotates the stack table 10. For further details on this rotating part, refer to Korean Patent Publication No. 10-2020-0023853, which is incorporated herein by reference.

In the electrode assembly manufacturing apparatus 100, the first electrode supply unit 30 may be located on one side of the stack table 10, and the second electrode supply unit 40 may be located on the other side of the stack table 10. In the illustrated configuration of the electrode assembly manufacturing apparatus 100, the rotating unit may alternately rotate the stack table 10 in the direction of the first electrode supply unit 30 and the second electrode supply unit 40.

For example, the separator supply unit 20 may be located at the top of the stack table 10, that is, along the stacking direction of the stack S. In this configuration, the first electrode supply unit 30 is located on the left side of the stack table 10, and the second electrode supply unit 40 is located on the right side of the stack table 10 based on the stacking direction of the stack S. can do.

In the illustrated configuration of the electrode assembly manufacturing apparatus 100, the rotary unit allows the stack table 10 to temporarily hold the first transfer head 32 or the first electrode 1 when stacking the first electrode 1. The stack table 10 can be rotated to face another first attachment device. When stacking the second electrode 2, the rotating unit is configured to place a stack table 10 so that the second attachment device or second transfer head 42 for temporarily holding the second electrode 2 and the stack table 10 face each other. ) can be rotated.

When using the electrode assembly manufacturing apparatus 100, the stacking portion 4a and the folding portion 4b of the first separator 4 are supplied by the separator supply unit 20 and placed on the stack table 10 to form a portion of the first separator 4. Can be mounted in an array. When the rotary unit rotates the stack table 10 to the left, the first electrode 1 supplied from the first electrode supply unit 30 can be supplied onto the first separator 4. Moreover, the rotating unit can rotate the stack table 10 to the right, and this rotation can occur at the same time that the first separator 4 is supplied. In this rotary configuration of the rotating unit, the first separator 4 may form a first pocket in the form of a left pocket covering the lower, right, and upper surfaces of the first electrode 1 of the laminate S. Here, the first electrode 1 of the stack S may be placed on the stack table 10 so that the upper surface of the first electrode 1 is partially covered by the first separator 4. In this case, the second electrode 2 may be supplied from the second electrode supply unit 40 to the portion of the first separator 4 covering the upper surface of the first electrode 1.

If the above process is repeated, the first separator 4 can be placed on the stack table 10 from the separator supply unit 20 in the form of a left pocket and a right pocket in a position opposite to the left pocket. In this configuration, when each portion of the first separator 4 is positioned to rest on the stack table 10, the left and right pockets alternately form respective left and right openings, wherein these left and right openings are It may be configured to accommodate the first electrode 1 and the second electrode 2 supplied by the first electrode supply unit 30 and the second electrode supply unit 40, respectively. Additionally, the folding portion 4b of the first separator 4, which may be in the form of a folded portion when the first separator 4 is folded, may be provided at a position facing the left and right openings (see FIG. 2). In some alternative arrangements, which may be mirror arrangements to the arrangement of the electrode assembly manufacturing apparatus 100, the first separator 4 is formed in the form of a right pocket covering the lower, left and upper surfaces of the second electrode 2. A first pocket may be formed. In this mirror arrangement, the second electrode 2 may be the first electrode of the stack S disposed on the stack table 10.

The stack table 10 may further include a table body (not shown) and a table heater (not shown) that determine the shape of the stack table 10, and the table heater is, for example, located on the main body of the stack table 10. , may be a resistance coil embedded underneath or inside. The table heater can heat the table body to heat the laminate S seated on the stack table 10.

The table heater may heat the laminate S before the laminate S is heated and compressed by the press unit 50 of the electrode assembly manufacturing apparatus 100. Preheating of the laminate S by such a table heater can shorten the time for heat to be conducted to the center of the laminate S, thereby reducing the pressing time required for sufficient pressurization by the press unit 50.

The first electrode 1 may be configured as an anode, and the second electrode 2 may be configured as a cathode, but the electrode assembly manufacturing apparatus 100 according to the present invention is not limited thereto. For example, the first electrode 1 ) may be composed of a cathode and the second electrode 2 may be composed of an anode.

In one embodiment, the positive electrode may be manufactured, for example, by coating a positive electrode current collector with a positive electrode coating mixture including a positive electrode active material, a conductive material, and a binder, and then drying the coating mixture. Fillers may be added to the mixture if necessary. Such materials may be any suitable materials used in the relevant field, especially materials commonly used for a particular application.

Specifically, the positive electrode active material may be, for example, a layered compound such as lithium cobalt oxide (LiCoO ₂ ) or lithium nickel oxide (LiNiO ₂ ) or a compound substituted with one or more transition metals; Lithium manganese oxide with the formula Li _1+x Mn _2-x O ₄ (where x is 0 to 0.33), LiMnO ₃ , LiMn ₂ O ₃ , LiMnO _{2 ,} etc.; lithium copper oxide (Li ₂ CuO ₂ ); Vanadium oxides such as LiV ₃ O ₈ , LiFe ₃ O ₄ , V ₂ O ₅ , and Cu ₂ V ₂ O ₇ ; Nisite-type lithium nickel oxide represented by the formula LiNi _1-x M _x O ₂ (where M = Co, Mn, Al, Cu, Fe, Mg, B or Ga and x = 0.01 to 0.3); _{Chemical formula LiMn 2 -x M} Lithium manganese complex oxide expressed as Ni, Cu or Zn); LiMn ₂ O ₄ in which part of Li in the chemical formula is replaced with an alkaline earth metal ion; disulfide compounds; Fe ₂ (MoO ₄ ) ₃ etc. may be mentioned, but it is not limited to these alone.

Materials that can be used for the positive electrode current collector are not particularly limited. The positive electrode current collector preferably does not undergo chemical changes when used in a battery and has a relatively high conductivity. For example, stainless steel, aluminum, nickel, titanium, calcined carbon, or the surface of aluminum or stainless steel treated with carbon, nickel, titanium, silver, etc. can be used. Preferably, the positive electrode current collector may be aluminum. Preferably, the adhesion between the current collector and the positive electrode coating mixture can be increased by including fine irregularities on the surface in contact with the coating mixture of the current collector. In addition, various forms such as films, sheets, foils, nets, porous materials, foams, and non-woven materials are possible. The positive electrode current collector may generally have a thickness of 3 ㎛ to 500 ㎛.

The conductive material contained in the positive electrode coating mixture may generally be included in 1 to 50% by weight of the total weight of the mixture containing the positive electrode active material. For example, graphite such as natural graphite or artificial graphite; Carbon black such as carbon black, acetylene black, Ketjen black, channel black, furnace black, lamp black, and summer black; Conductive fibers such as carbon fiber and metal fiber; Metal powders such as carbon fluoride, aluminum, and nickel powder; Conductive whiskeys such as zinc oxide and potassium titanate; Conductive metal oxides such as titanium oxide; Conductive materials such as polyphenylene derivatives may be used.

The binder of the positive electrode coating mixture is a component that assists in binding the active material and the conductive material and the coating mixture to the current collector. This binder may generally be included in an amount of 1 to 50% by weight of the total weight of the mixture containing the positive electrode active material. Examples of such binders include polyvinylidene fluoride, polyvinyl alcohol, carboxymethylcellulose (CMC), starch, hydroxypropylcellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, and polyethylene. , polypropylene, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene butyrene rubber, fluorine rubber, and various copolymers.

Fillers optionally added to the positive electrode coating mixture may be used as ingredients to inhibit expansion of the positive electrode. These fillers are not particularly limited and may include fibrous materials that do not cause chemical changes when used in batteries. For example, olipine polymers such as polyethylene and polypropylene; Fibrous materials such as glass fiber and carbon fiber are used.

In one embodiment, the negative electrode can be manufactured by applying, drying, and compressing the negative electrode active material on the negative electrode current collector, and if necessary, conductive materials, binders, fillers, etc. as described above may be optionally further included. In this case as well, materials commonly used in the relevant field may be used. Specifically, the negative electrode active material includes, for example, carbon such as non-graphitizable carbon and graphitic carbon; Li _{x Fe 2} O ₃ ( _0≤x≤1 ), Li _x WO ₂ (0≤x≤1 _{) , Sn} : Al, B, P, Si, elements of groups 1, 2, and 3 of the periodic table, halogen; metal complex oxides such as 0<x≤1;1≤y≤3;1≤z≤8); lithium metal; lithium alloy; silicon-based alloy; tin-based alloy; SnO, SnO ₂ , PbO, PbO ₂ , Pb ₂ O ₃ , Pb ₃ O ₄ , Sb ₂ O ₃ , Sb ₂ O ₄ , Sb ₂ O ₅ , GeO, GeO ₂ , Bi ₂ O ₃ , Bi ₂ O ₄ , and metal oxides such as Bi ₂ O ₅ ; Conductive polymers such as polyacetylene; Li-Co-Ni based materials, etc. can be used.

Materials that can be used for the negative electrode current collector are not particularly limited. It is desirable for the negative electrode current collector to have relatively high conductivity without causing chemical changes when used in a battery. For example, copper, stainless steel, aluminum, nickel, titanium, calcined carbon, surface treatment of copper or stainless steel with carbon, nickel, titanium, silver, etc., aluminum-cadmium alloy, etc. can be used.

Additionally, like the positive electrode current collector, the bonding force of the negative electrode active material can be strengthened by forming fine irregularities on the surface. It can be used in various forms such as films, sheets, foils, nets, porous materials, foams, and non-woven materials. Additionally, the negative electrode current collector may generally have a thickness of 3 ㎛ to 500 ㎛.

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

This SRS separator does not undergo high-temperature heat shrinkage due to the heat resistance of the inorganic particles, so even if the electrode assembly is penetrated by the needle-shaped conductor, the elongation of the safety separator can be maintained.

Such an SRS separator may have a uniform pore structure formed by the pore structure contained in the separator substrate itself as well as the interstitial volume between the inorganic particles that are components of the coating layer. The pores can not only significantly alleviate external shocks applied to the electrode assembly, but also allow smooth movement of lithium ions through the pores and fill with a large amount of electrolyte solution, resulting in a high impregnation rate, thereby improving battery performance. We can work together.

In one embodiment of the present invention, the width dimension of the separator (perpendicular to the longitudinal dimension in which the separator is unfolded) extends outward on both sides beyond the edges corresponding to adjacent anodes and cathodes (hereinafter referred to as “surplus portion”). The dimensions can be determined by . In addition, it has a structure in which a coating layer thicker than the thickness of the separator is formed on one or both sides of the separator surplus portion to prevent the separator from shrinking. For further details on the thick coating layer of the excess portion extending outward of the separator, see Korean Patent Publication No. 10-2016-0054219, the entire contents of which are incorporated herein by reference. In one embodiment of the present invention, the surplus portion of the separator may have a size of 5% to 12% of the width of the separator. Furthermore, in one embodiment of the present invention, the coating layer may be coated on both sides of the separator in a size of 50% to 90% of the width of the surplus portion of the separator on one side. Additionally, the widths of the coating layers on both sides may be the same or different sizes.

In one embodiment of the present invention, the coating layer may include inorganic particles and a binder polymer.

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

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

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

In one embodiment of the present invention, the substrate and the coating layer exist in a form in which pores and the coating layer on the surface of the polyolefin-based separator substrate are entangled with each other (anchoring), so that the separator substrate and the active layer can be physically firmly bonded. The thickness ratio between the substrate of the separator and the active layer may be 9:1 to 1:9. Preferably the thickness ratio may be 5:5.

In one embodiment of the present invention, the inorganic particles may be inorganic particles commonly used in the art. The inorganic particles interact with each other to form micropores in the form of empty spaces between the inorganic particles and at the same time help to structurally maintain the physical form of the coating layer. In addition, since the inorganic particles generally have the property that their physical properties do not change even at high temperatures of 200°C or higher, the formed organic/inorganic composite porous film has excellent heat resistance.

Additionally, the material that can be used for the inorganic particles is not particularly limited, but is preferably an electrochemically stable material. That is, the inorganic particles that can be used in the present invention are not particularly limited as long as they do not cause oxidation and/or reduction reactions in the operating voltage range of the battery to which they are applied (e.g., 0 to 5 V based on Li/Li+). In particular, when using inorganic particles capable of ion transport, performance can be improved by increasing the ion conductivity within the electrochemical device. Therefore, it is desirable to use inorganic particles with as high an ion conductivity as possible. In addition, when the inorganic particles have a high density, it is difficult to disperse the inorganic particles during coating, and there is a problem of increasing the weight of the battery during battery manufacturing. Therefore, it is desirable to use inorganic particles with as low a density as possible. In addition, in the case of an inorganic material with a high dielectric constant, 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 solution.

For the reasons described above, the inorganic particles may be one or more types selected from the group consisting of inorganic particles having piezoelectricity and inorganic particles having lithium ion transport ability.

The piezoelectric inorganic particles refer to materials that are insulators at normal pressure but have the property of conducting electricity due to changes in their internal structure when a certain pressure is applied. In addition, it is a material that exhibits high dielectric constant characteristics with a dielectric constant of 100 or more. Inorganic particles with piezoelectricity are also materials that generate a charge when stretched or compressed by applying a certain pressure, so that one side is positively charged and the other side is negatively charged, thereby generating a potential difference between both sides (e.g. , separation membrane).

When inorganic particles with the above characteristics are used as a coating layer component, if an internal short circuit of the positive electrode occurs due to an external impact such as a needle-shaped conductor, the anode and the cathode are in direct contact due to the inorganic particles coated on the separator. You may not be able to do it. In addition, due to the piezoelectricity of the inorganic particles, a potential difference occurs within the particle, which causes electron movement (i.e., a minute flow of current) between the two electrodes, which can gradually reduce the voltage of the battery and thereby improve safety. there is.

Examples of the inorganic particles having piezoelectricity include BaTiO ₃ , Pb(Zr,Ti)O ₃ (PZT), Pb ₁ - _x La _x Zr ₁ - _y Ti _y O ₃ (PLZT), PB (Mg ₃ Nb _2/3 )O ₃ -PbTiO ₃ It may be one or more selected from the group consisting of (PMN-PT) and hafnia (HfO ₂ ), but is not limited thereto.

The inorganic particle having the ability to transport lithium ions refers to an inorganic particle that contains lithium element but does not store lithium, but instead has the function of moving lithium ions. Inorganic particles capable of transmitting lithium ions can transmit and move lithium ions due to a type of defect that exists inside the particle structure. As a result, lithium ion conductivity in the battery is improved, thereby improving battery performance.

Examples of inorganic particles having the ability to transport lithium ions include lithium phosphate (Li ₃ PO ₄ ), lithium titanium phosphate (Li _x Ti _y (PO ₄ ) ₃ , 0<x<2, 0<y<3), and lithium aluminum. Titanium phosphate (Li _x Al _y Ti _z (PO _{4 ) 3} , 0<x _< 2, 0<y<1, 0<z<3), (LiAlTiP) <y<13), lithium lanthanum titanate (Li _x La _y TiO ₃ , 0<x<2, 0<y<3), lithium germanium thiophosphate (Li _x Ge _y P _z S _w , 0<x <4, 0<y<1, 0<z<1, 0<w<5), lithium nitride (Li _x N _y , 0<x<4, 0<y<2), SiS ₂ (Li _x Si _y S _z , 0<x<3, 0<y<2, 0<z<4) series glass and P ₂ S ₅ (Li _x P _y S _z , 0<x<3, 0<y<3, 0 It may be one or more types selected from the group consisting of <z<7) series glass, but is not limited thereto.

The composition ratio of the inorganic particles and binder polymer constituting the coating layer of the separator is not particularly limited, but can be adjusted within the range of 10:90 to 99:1 weight%, and is preferably in the range of 80:20 to 99:1 weight%. If the composition ratio is less than 10:90% by weight, the polymer content becomes too high, which may reduce the pore size and porosity due to a decrease in the empty space formed between the inorganic particles, resulting in a decrease in final battery performance. On the other hand, if the ratio exceeds 99:1 wt%, the mechanical properties of the final organic/inorganic composite porous separator may deteriorate due to weakening of the adhesion between inorganic materials because the polymer content is too small.

In one embodiment of the present invention, the binder polymer commonly used in the art may be used.

The coating layer of the organic/inorganic composite porous separator may further include other commonly known additives in addition to the above-described inorganic particles and binder polymer.

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

Referring again to FIGS. 1 and 2, the first separator 4 has a plurality of stacked parts 4a located between the first electrode 1 and the second electrode 2 and the side of the adjacent stacked part 4a. It may include a folding part 4b connected and extending therebetween. In this specification, the side of the stacked portion 4a refers to one side in a direction perpendicular to the stacking direction of the stacked product S. Accordingly, the side surface of the stacked portion 4a is a position corresponding to the side surface of the stacked product S.

In the laminate S, the folding portions 4b may be alternately positioned on the sides of each layer of the laminate. The adjacent stacked portion 4a and the folded portion 4b attached to the adjacent stacked portion 4a may have openings formed in the first separator 4. Here, the side of the stack (S) facing the folding portion (4b) may be defined by the first and second electrodes accommodated in the opening of the first separator (4). In this way, the laminate S may be alternately provided with openings and folding portions 4b defined by the first separator 4 on a pair of opposing sides for each layer of the laminate.

The first electrode 1 and the second electrode 2 may not be disposed inside or on the folding part 4b.

As shown in FIG. 1, the second separator 5 may be located on the upper surface, lower surface, and at least one pair of opposing sides of the stack S. That is, as further shown in FIG. 1, the end of the second separator 5 is connected to the end of the first separator 4 and can be wound around the laminate S at least once.

Accordingly, the inner separator surface of the second separator 5 located on a pair of opposing sides of the stack S may face the folding portion 4b. Additionally, the second separator 5 located on both sides of at least one pair of the stack S may be in contact with at least one folding portion 4b.

The electrode assembly 10 may be manufactured by heating or heat-compressing the side of the laminate S when the second separator 5 is wound around the outermost layer of the laminate S. For example, when the electrode assembly 10 is wound around the second separator 5, the side sealing portion 60 (FIG. 3) includes a pair of pressing blocks 60a and 60b on both sides of the stack S. and related description) may be manufactured by heating or heat pressing. The space formed between the folding portion 4b located on both sides of the laminate S and the inner separator surface of the second separator 5 facing the folding portion 4b opens at least one of the side and inner separator surfaces. It can be condensed by fusion. Thermal fusion of the folding portion 4b and the second separator 5 is performed by wrapping the second separator 5 around the outermost layer of the laminate S and using the side sealing portion 60 to seal the laminate S. It can be formed by heating and compressing opposing sides.

The electrode assembly 10 may be manufactured by heat-compressing some or all of the upper surface, lower surface, and both sides of the multilayer S, in which the second separator 5 is wound around the outermost layer of the multilayer S. For example, the electrode assembly 10 heats and compresses the upper and lower surfaces of the laminate S with a press part 50 (see FIG. 3 and the related description in this specification), and separately or simultaneously with a side sealing part ( The electrode assembly 10 can be manufactured by heating and compressing both sides of the laminate S using 60).

The press unit 50 may include a pair of pressing blocks 50a and 50b. The space between the first electrode 1, the first separator 4, and the second electrode 2 can be condensed by heat-sealing the upper and lower surfaces of the laminate S to the inner separator surface of the second separator 5. . In this way, the upper and lower surfaces are thermally bonded to the second separator 5 by forming the laminate ( S) can be formed by heating and compressing. Here, the upper and lower surfaces of the laminate S refer to the outer surfaces of the laminate S located above and below the stacking direction.

Accordingly, in one embodiment of the electrode assembly 10, the first electrode 1 and the first separator 4, and the first separator 4 and the second electrode 2 may be bonded. Furthermore, as the upper and lower surfaces of the laminate S are heated and compressed, the folded portion 4b is compressed, and adjacent folded portions 4b may be heat-sealed to each other. That is, two or more folding portions 4b can be joined to each other. In that respect, unlike the schematic representation shown in FIG. 1, the folding portion 4b extends outward a relatively significant distance past the ends of the electrodes 1 and 2, as shown in the examples of FIGS. 5 and 6. It may be extended. In this way, the folding portion 4b can be deflected and bonded to each other through any one or any combination of heat and compression of the side seal portion 60 and the press portion 50.

In one embodiment, the inner surface of the second separator 5 positioned to face the folding portion 4b of the two or more bonded folding portions 4b of the first separator 4 and the folding portion 4b of the laminate S is can be joined to each other.

In one embodiment, the folding portion 4b may be bonded to the inner surface of the second separator 5 in a state in which adjacent folding portions 4b of the folding portions 4b are not bonded to each other. At this time, the folding portion 4b may be bonded to the second separator 5 in a folded state without being bent in a direction parallel to the stacking direction of the laminate S, or the folding portion 4b may be bonded to the second separator 5 ) can be bent one or more times in any direction parallel to the stacking direction.

The length of each folding portion 4b may range from 0.1% to 1% based on 100% of the total length of the lamination portion 4a to which each folding portion 4b is attached. At this time, the length of the folding part 4b may mean that the folding part 4b is not bent.

If the length of the folding portion 4b exceeds 1% of the total length of the laminated portion 4a to which the folding portion 4b is attached, the electrode density and energy density of the electrode assembly 10 may be reduced. Here, the total length of the stacked portion 4a refers to the length from the folded portion 4b to the opening on the opposite side of the folded portion 4b.

Additionally, the number of folding portions 4b bonded to the inner surface of the second separator 5 may be 30% or more of the total number of folding portions 4b. Preferably, the number of folding portions 4b may be 40% or more, and more preferably 50% or more.

In a state where a plurality of adjacent folding parts 4b are bonded to each other, any folding part 4b can be bonded to the inner surface of the second separator 5. When the folding portion 4b of the first separator 4 and the adjacent folding portion 4b are bonded, the area of the second separator 5 bonded to any folding portion 4b is opposite to that of the laminate S. It may be 30% or more of the total area of the second separator 5 located on the pair of side surfaces. Preferably, the area of the second separator may be 40% or more, and more preferably 50% or more.

In the electrode assembly 10 where the number of folding parts 4b to be joined and the bonding area between the folding parts 4b and the second separator 5 are less than the above-mentioned 30%, the side of the laminate S is not sufficiently fixed. It may have part 4b. In this case, it may not be easy to put the electrode assembly 10 into a pouch or can. In addition, in the electrode assembly 10 in which the number of joints of the folding portion 4b and the area of the second separator 5 satisfy the above-mentioned 30%, the folding portion 4b may protrude from the sealed portion of the pouch. and the electrode assembly 10 may be undesirably sealed with the pouch.

Moreover, because the difference between the size of the pouch or can and the size of the electrode increases, there is a limit to minimizing the size of the pouch or can.

In one embodiment, when adjacent folding portions 4b are bonded to each other, more than 50% of the total number of folding portions 4b may be bonded to each other. In one embodiment, the width of the first electrode 1 and the second electrode 2 may be smaller than the width of the stack S. In other words, the electrode assembly 10 is configured so that the ends of the first electrode 1 and the second electrode 2 do not overlap or lie below each other in the folding portion 4b and the layer adjacent to the layer of the folding portion 4b. can be located At this time, the first electrode 1 or the second electrode 2 is not located between the adjacent folding parts 4b, so the adjacent folding parts 4b can be adhered.

For example, if the electrode assembly 10 includes 10 folding portions 4b and 50% of the total number of folding portions 4b are glued together, the electrode assembly 10 has two folding portions 4b glued together ( 4b), three folding parts 4b glued together and five folding parts 4b not glued to adjacent folding parts 4b may be included.

Referring to FIGS. 3 and 4 , as an example of the electrode assembly manufacturing apparatus 100 , the separator supply unit 20 may be configured to supply the first separator 4 to the stack table 10 . For detailed information about the separator supply unit 20, refer to Republic of Korea Patent Publication No. 10-2020-0023853. For example, as shown in FIG. 4 , the separator supply unit 20 may be located at the top of the stack table 10 . Additionally, the separator supply unit 20 may include a separator roll 21 on which the first separator 4 can be wound. The first separator 4 wound around the separator roll 21 may be gradually unwound by gravity and supplied to the stack table 10.

A passage through which the first separator 4 passes is formed in the separator supply unit 20. The separator supply unit 20 may include a separator heating unit (not shown) to heat the first separator 4 passing therethrough. For detailed information about this separation foil heating unit, refer to Republic of Korea Patent Publication No. 10-2020-0023853.

The separator heating unit may include a pair of main bodies (not shown) and a separator heater (not shown) that heats the main bodies. A pair of main bodies may be positioned on both sides of the first separator 4 at a predetermined distance apart to allow the first separator 4 to pass through. For example, the first separator 4 may pass through the separator heater in a non-contact manner so that the first separator 4 can be heated in a non-contact manner. In one embodiment, the pair of main bodies of the separator heating unit may be formed, for example, in a rectangular block shape.

As an example of the electrode assembly manufacturing apparatus 100, the first electrode supply unit 30 supplies the first electrode 1 to the stack table 10 and stacks the first electrode 1 on the stack table 10. It can be configured to do so. The first electrode supply unit 30 may include a first electrode seating table 31 on which the first electrode 1 is placed before being stacked on the stack table 10 . Additionally, the first electrode supply unit 30 may include a first electrode roll 33, a first cutter 34, a first conveyor 35, and a first electrode supply head 36. The first electrode supply unit 30 supplies one of the first electrodes 1 to the first electrode seating table 31 and places the first electrode sheet on which the first electrode 1 is formed on the first electrode roll 33. Roll it up and slowly release it. The first cutter 34 may cut the first electrode 1 from the first electrode sheet supplied from the first electrode roll 33 to a preset length. The first cutter 34 may cut the first electrode sheet so that the first electrode tab 1a protrudes from the end of the first electrode 1.

The first electrode 1 cut by the first cutter 34 may be supplied to the first conveyor 35, and the first conveyor 35, which may be in the form of a belt as shown, may provide the first electrode 1 ) can be moved to the first electrode seating table 31. The first electrode supply head 36 (e.g., via a vacuum fitting, suction cup or similar fitting or other temporary attachment format such as a magnetic attachment) is connected to the first electrode 1 disposed on the first conveyor 35. can be picked up and placed on the first electrode seating table 31.

As shown, the first electrode supply unit 30 may include a first transfer head 32 and a first moving unit 37 through which the first transfer head 32 can extend and vibrate. The first transfer head 32 (e.g., via a vacuum fitting, suction cup, or similar fitting, or other temporary form of attachment such as magnetic attachment) attaches a first electrode seated to the first electrode seating table 31. You can pick up (1). In one embodiment, the first transfer head 32 may be configured to suction the first electrode 1 through a vacuum suction port to attach the first electrode 1 to the bottom surface of the first transfer head 32. A vacuum suction unit (not shown) may be included on the bottom surface of the transfer head. The flow path formed in the first transfer head 32 may connect a vacuum suction port and a vacuum suction device (not shown).

The first moving part 37 picks up the first electrode 1 seated on the first electrode seating table 31, and the first suction head 32 can be released, for example, the first electrode ( 1) configured to move the first suction head 32 to a position resting on the stack table 10 by reducing or eliminating the vacuum suction or other force applied to the first electrode 1 to maintain it relative to the transfer head. can do. In this way, the first transfer head 32 transfers the first electrode 1 from the first electrode seating table 31 through the other electrodes 1 and 2 to the electrode placed on or on the stack table 10. 1 It can be transferred to a section of the separator (4).

The second electrode supply unit 40 may have or essentially have a mirror configuration of the first electrode supply unit 30 . In this way, the second electrode supply unit 40 supplies the second electrode 2 to a portion of the stack S seated on the stack table 10, and this part of the stack S on the stack table 10 The second electrode 2 can be stacked on the portion.

The second electrode supply unit 40 may include a second electrode seating table 41 on which the second electrode 2 is placed before being moved to and stacked on the stacked product S portion on the stacking table 10 .

The second electrode supply unit 40 includes a second electrode roll 43 on which the second electrode sheet on which the second electrode 2 is formed is wound, and the second electrode sheet is cut at regular intervals to form the second electrode 2. It may include a second cutter 44. A second conveyor 45 that moves the second electrode 2 cut by the second cutter 44 to a certain size while unwinding the second electrode sheet from the second electrode roll 43. and the second electrode 2 is placed on the second electrode seating table 41.

Like the first cutter 34, the second cutter 44 is a second electrode sheet such that the formed second electrode 2 includes a second electrode tab 2a protruding from the end of the second electrode 2. It can be cut.

In addition, the second electrode supply unit 40 includes a second transfer head 42 that picks up the second electrode 2 seated on the second electrode seating table 41 and, for example, picks up the second electrode 2. 2 moving to the top of the stack table 10 where the second transfer head 42 can be released by reducing or eliminating the vacuum suction or other force applied to the second electrode 2 to hold it against the transfer head 42 It may include a second moving part 47 configured to do so. At this time, the second transfer head 42 may stack the second electrode 2 on a portion of the stack S on the stack table 10. The second transfer head 42 is installed in the same manner as the first transfer head 32 so that the second electrode 2 can be temporarily attached to the second transfer head 42 on the bottom surface of the second transfer head 42. can be formed.

The side sealing unit 60 may surround the outermost portion of the stack S with the first separator 4 and heat at least one side of the stack S. That is, the side sealing portion 60 applies heat to at least one side of the laminate S to provide or increase adhesion to the coating layer component applied to one side of the first separator 4 and facing the electrodes 1 and 2. You can do it.

The pressing direction of the side sealing unit 60 may be perpendicular to the pressing direction of the press unit 50, which will be described further here.

In one embodiment, the side sealing portion 60 may include a pair of heating bars 60a and 60b. A pair of heating bars 60a and 60b may be moved toward or away from each other to heat and compress the stack S from the side toward the center of the stack. That is, the side sealing unit 60 can heat and compress the multilayer body (S) from the side of the multilayer body (S).

The side of the laminate (S) is the side that includes the folded portion (P) of the laminate (S). Preferably, the side of the laminate is not located on the same side of the electrodes 1, 2 on which the electrode tab 1a is located.

The laminate (S) may be provided in a structure in which one or more first electrodes (1), a first separator (4), and a second electrode (2) are stacked in that order, and the outermost layer is surrounded by the first separator (4). there is. The side sealing portion 60 heats and compresses the outermost part of the first separator 4 (hereinafter referred to as the outermost separator) surrounding the outermost part of the laminate S to form the side surface of the laminate S and the laminate ( The folded portion (P) included in S) can be heated and compressed. Accordingly, the side sealing portion 60 heats and compresses the side surfaces of the laminate S to adhere the plurality of folded portions P included in the laminate S, and forms the outermost first separator 4 and the outermost separator 4. The folding portion of the first separator 4 facing the outer first separator 4, the first electrode 1, and the second electrode 2 can be bonded.

The electrode assembly manufacturing apparatus 100 may further include a pressing portion 50. The pressing unit 50 is heated to compress the laminate S. The first electrode 1, the first separator 4, and the second electrode 2 can be joined by pressing the pressing portion 50.

The pressing unit 50 may include a pair of pressing blocks 50a and 50b that may be positioned adjacent to the upper and lower surfaces of the laminate S. A pair of pressure blocks 50a and 50b may move in directions toward each other to compress the upper and lower surfaces of the stack S, and then move away from each other according to this compression.

When the first separator 4 is configured to surround the outer surface of the laminate S, the inner surface of the outermost first separator 4, the side surfaces of the first and second electrodes 1 and 2, and the first separator The space between the inner surface of (4) and the opposing outermost first separator (4) may be bonded. In this configuration, the outermost first separator 4 includes the upper and lower surfaces of the laminate S and two opposing sides between the upper and lower surfaces of the outermost first separator 4 surrounding the laminate S. can do.

Accordingly, when forming the electrode assembly 10 by stacking the first electrode 1, the first separator 4, and the second electrode 2, the first and second electrodes 1 are formed by the press unit 50. , 2) and the position of the first separator 4 can be prevented from being dislocated and the stacked form unraveling.

The press unit 50 includes a press heater (not shown) that heats a pair of pressurizing blocks 50a and 50b so that the pair of pressurizing blocks 50a and 50b can heat the laminate S while compressing the laminate. ) may further be included. In this way, when the laminate S is compressed by the press unit 50, the first electrode 1, the section of the first separator 4 adjacent to the first electrode 1, and the second electrode 2 Heat fusion between the section of the first separator 4 adjacent to the second electrode 2 can be better achieved.

As shown in Figure 4, the length and width of each of the pair of pressure blocks (50a, 50b) can be formed to be longer than the length and width of the laminate (S), and can be formed as a flat pressure surface. You can.

Additionally, the pair of pressure blocks 50a and 50b may be provided as rectangular blocks in the shape of a rectangular parallelepiped.

In one embodiment, the electrode assembly manufacturing apparatus 100 may further include a third moving part (not shown) attached to a third transfer head (not shown) and configured to rotate or otherwise move. The third moving unit and the third transfer head may be the same or similar to the first and second moving units 37 and 47 and the first and second transfer heads 32 and 42, respectively.

In one embodiment, the third transfer head may suction the stacked material S seated on the stack table 10. The third transfer head is provided with a vacuum suction part on the bottom surface, and the laminate S can be temporarily attached to the lower surface of the third transfer head by suctioning the laminate S through the vacuum suction port. The third transfer head may have a passage connecting the vacuum suction port and the vacuum suction device.

The third moving unit moves the third transfer head to the side sealing unit 60 so that the laminate S seated on the stack table 10 can be moved to the side sealing unit 60. For example, one of translation and rotation, or You can move it through both.

In one embodiment, the third transfer head may be temporarily attached to the stack S in the manner described above when the stack is seated on the press unit 50. In one embodiment, the third moving unit is configured to move the third transfer head to the side sealing unit 60 so that the laminate S seated on the press unit 50 can be moved to the side sealing unit 60. You can.

Referring to FIG. 6, the electrode assembly manufacturing method may include a step of manufacturing a laminate (S10) and a side sealing step (S30).

In the step S10 of manufacturing a laminate, a first electrode (e.g., first electrode 1), a separator (e.g., first separator 4), and a second electrode (e.g., The laminate may be manufactured by supplying two electrodes (2) to an in-process laminate on a stack table (e.g., stack table 10).

In step S11 of step S10 of manufacturing the laminate, a portion of the separator is supplied to the stack table. In one embodiment, the separator portion is mounted to the stack table by a retaining mechanism such as, but not limited to, a clamp or clamp set or other clamping mechanism. In step S12, the stack table may rotate in a direction toward the first electrode supply unit, for example, the first electrode supply unit 30. In step S13, the first electrode may be supplied and then mounted on a stack table or otherwise laminated on a separator portion laminated on the stack table. In step S14, the stack table is rotated toward the second electrode supply unit, for example, the second electrode supply unit 40, so that an additional portion of the separator can be folded and overlapped with the first electrode. In step S15, the second electrode may be laminated to an additional portion of the separator after being supplied. In step (S16), steps (S12), (S13), (S14), and (S15) may be repeated to sequentially add one or more first electrodes, a separator portion, and one or more second electrodes. In repeating the step (S12), another part of the separator is folded and overlapped over the second electrode through rotation of the stack table and the next first electrode is supplied, and the supplied first electrode is stacked on the additional part of the separator. It can be. The separator may be stacked in a zigzag manner between the first electrode and the second electrode through alternate rotation of the stack table.

In addition, in step S17 of step S10 of manufacturing the laminate, the outermost layer of the laminate may be surrounded by the separator by rotating the separator in one direction. Here, the outermost part of the laminate includes the upper surface, lower surface, and both opposing sides of the laminate. Each side may extend in a plane parallel to the stacking direction of the laminate. Each of the sides may exclude all sides on which an electrode tab, for example, the electrode tab 1a is located. The top and bottom surfaces of the laminate each include a plane perpendicular to one or both sides of the laminate.

The side sealing step (S30) may heat at least one side of the laminate. In this operation, one or both opposing sides of the laminate may be heated and compressed to compress the laminate. In this step, the pair of heating bars, e.g., heating bars 60a and 60b, are heated along the side of the laminate for 10 seconds, with the heating bars at a side sealing temperature of 100°C to 200°C. The separator can be pressurized for the following time.

If the side sealing temperature is less than 100°C, the binder applied to the separator may not have sufficient adhesion, and if the side sealing temperature exceeds 200°C or the pressing time exceeds 10 seconds, a pair of The increase in adhesion effect may be minimal compared to the energy supplied to heat the heating bar.

And, during the side sealing step (S30), at least one side of the laminate may be compressed with a pressure ranging from 0.1 MPa to 1.5 MPa. Preferably, the one or more sides can be pressurized with a pressure ranging from 0.1 MPa to 1 MPa, more preferably with a pressure ranging from 0.1 MPa to 0.5 MPa.

That is, in the side sealing step (S30), both sides of the laminate can be simultaneously heated and compressed in a direction perpendicular to the side and toward the center surface of the laminate.

When the pressure compressing the side of the covered laminate satisfies the above pressure range, damage to the first electrode and the second electrode can be prevented or at least suppressed by contact and bonding between the outermost separator and the folded portion.

The electrode assembly manufacturing method may further include heating and pressurizing the laminate (S20). In this step, a pair of heat press blocks, for example a pair of press blocks 50a, 50b, compress the laminate in a downward and optionally upward direction toward the laminate generally parallel to the side of the laminate. can do. Due to the heat conducted from the pair of pressure blocks, the adhesion between the binder and the separator to which the binder is applied can be improved, and the separator and the first and second electrodes can be further combined by pressure.

Referring to FIG. 7 , each folding portion 4b may be bent one or more times in a direction parallel to the stacking direction of the stacked product S. In this way, the second separator 5 is directed toward the end of the first electrode 1 and the end of the first electrode 1 of the second separator 5 in the electrode assembly 10 wound around the laminate S. The distance between the internal separator surface of the second separator 5 and the distance between the end of the second electrode 2 and the portion of the internal separator surface of the second separator 5 facing the end of the second electrode 2 are reduced, thereby reducing the electrode The overall width of assembly 10 may be reduced.

Between the first electrode (1) or second electrode (2) and the inner separator surface portion of the second separator (5) adjacent to the end of the first electrode (1) or second electrode (2) of the electrode assembly (10) The distance may be reduced by 50% to 95% based on 100% of the total length of the folding portion 4b. The entire length of the folding portion 4b is in contact with the second separator 5 at the end of the first electrode 1 or the second electrode 2 when the folding portion 4b is in a non-refracting state. is the distance to the end of .

As the length of the folding portion 4b is reduced by 50% to 95% compared to the total length of the folding portion 4b, the folding portion 4b that does not include the first electrode 1 and the second electrode 2 By partially reducing the electrode density and energy density of the electrode assembly 10, it is possible to increase the electrode density and energy density.

The wet adhesive force of the folding portion 4b of the electrode assembly 10 and the second separator 5 bonded to the folding portion 4b may be in the range of 40 gf/25 mm to 70 gf/25 mm.

Experiment example

The following experiment was performed to measure the battery characteristics according to the adhesion rate and adhesion area between the inner separator surface of the outermost part and the side end of the separator serving as the second separator of the laminate included in the electrode assembly.

Example

An electrode assembly was manufactured by folding the separator in a zigzag shape, placing the anode and cathode alternately between the cross sections of the folded separator, and surrounding the outermost layer of the laminate with the separator. The resulting electrode assembly was bonded to the entire laminate by compressing the upper and lower surfaces of the laminate using a heated press unit, and side sealing was performed by compressing both opposing sides of the laminate using a heated side sealing unit.

Example 1

In Example 1, the laminate was compressed at a pressure of 0.15 MPa using a side seal, and the folding portion of the separator was bonded to an area of 30% of the total area of the inner separator surface located on the side of the laminate opposite the folding portion. Includes an electrode assembly.

Example 2

Example 2 is an electrode assembly bonded to 80% of the total area of the inner separator surface of the separator located on the side of the laminate where the side part of the separator faces the side part by compressing the laminate at a pressure of 0.25 MPa using a side sealing part. Includes.

Comparative Example 1

Comparative Example 1 includes an electrode assembly in which the laminate was compressed to a pressure of 0.05 MPa using a side sealing portion.

Comparative Example 2

Comparative Example 2 is an electrode assembly bonded to 20% of the total area of the inner separator surface of the separator located on the side of the laminate where the side part of the separator faces the side part by compressing the laminate with a pressure of 0.10 MPa using a side sealing part. Includes.

Comparative Example 3

Comparative Example 3 is an electrode assembly bonded to 90% of the total area of the inner separator surface of the separator located on the side of the laminate where the side part of the separator faces the side part by compressing the laminate at a pressure of 0.30 MPa using a side seal. Includes.

press department side ceiling temperature
(℃) enter
(Mpa) hour
(s) temperature
(℃) enter
(Mpa) hour
(s) Example 1 70 1.91 15 150 0.15 3 Example 2 70 1.91 15 150 0.25 3 Comparative Example 1 70 1.91 15 150 0.05 3 Comparative Example 2 70 1.91 15 150 0.10 3 Comparative Example 3 70 1.91 15 150 0.30 3

cathode damage Side sealing degree Side separator lifting Example 1 doesn't exist good No restlessness Example 2 doesn't exist good No restlessness Comparative Example 1 not measurable Comparative Example 2 doesn't exist bad No restlessness Comparative Example 3 doesn't exist good Excitation occurs

Table 2 shows the results of measuring damage to the cathode of the electrode assembly, the degree of adhesion between the folding portion and the portion of the separator located on the folding portion, and the degree of lifting (lifting) of the outermost portion of the separator located on the side of the electrode assembly.

At this time, the degree of side sealing was observed with the naked eye based on the degree of adhesion between the folding portion of the separator and the outermost part of the separator serving as the second separator. The degree of lifting of the second or side separator means that the second separator is pushed to the upper or lower surface of the electrode assembly, and that a part of the separator located on the upper and lower surfaces of the electrode assembly is not in close contact with the electrode.

Referring to Table 2, in Comparative Example 1, the pressure applied by the side seal was low, so the electrode assembly could not be compressed, and the damage to the cathode, the degree of side sealing, or the degree of lifting of the second separator could not be measured.

In the case of Comparative Example 2, although the side sealing part presses the side of the electrode assembly, the second separator located on the side of the electrode assembly does not move to the folding part due to low pressure, so it can be seen that the adhesive force between the folding part and the second separator is reduced.

In Comparative Example 3, it can be seen that the pressure applied to the side of the electrode assembly by the side sealing part was large. In this way, the second separator located on the side of the electrode assembly rises above the cathode, and the cathode pushes the separator located on the upper or lower surface of the electrode assembly. It can be visually confirmed that the separator located on the upper or lower surface of the electrode assembly is folded.

Although the present invention has been described above with reference to preferred embodiments, those skilled in the art may make various modifications and changes to the present invention without departing from the spirit and scope of the present invention as set forth in the claims below. You will understand that you can do it.

S: Laminate
1: first electrode
2: second electrode
4: first separator
4a: Laminated section
4b: folding part
5: second separator
100: Electrode assembly manufacturing device
10: Stack table
20: Separator supply unit
21: Separator roll
22: Separator heating unit
30: first electrode supply unit
31: first electrode seating table
32: first transfer head
33: first electrode roll
34: first cutter
35: first conveyor
36: first electrode supply head
37: first moving part
40: second electrode supply unit
41: Second electrode seating table
42: second transfer head
43: second electrode roll
44: second cutter
45: second conveyor
46: second electrode supply head
47: second moving part
50: Press department
50a, 50b: A pair of pressurizing blocks
60: Side sealing part
60a, 60b: Heating block

Claims (17)

A laminate including a first electrode, a second electrode, and a first separator folded in a zigzag shape between the first electrode and the second electrode, and located on the upper surface, lower surface, and at least one pair of opposing sides of the laminate. An electrode assembly manufacturing apparatus for manufacturing a laminate including a second separator,
A stack table supporting the stacked product;
a separator supply unit supplying portions of the first separator and the second separator to the stack table;
a first electrode supply unit for stacking the first electrode on the first separator supported on the stack table;
a second electrode supply unit configured to stack the second electrode on the first separator supported by the stack table;
A press unit that presses the laminate in a direction parallel to the direction of stacking the laminate, and
A side sealing portion that heats at least one side of the laminate to bond the second separator positioned on at least a pair of opposing sides of the laminate to the side of the laminate,
The side sealing portion includes a pair of heating bars, and the pair of heating bars move in directions facing each other and press the side of the laminate,
The electrode assembly manufacturing apparatus wherein the side sealing unit presses at least one side of the laminate with a pressure of 0.1 MPa to 1.5 MPa. delete delete The electrode assembly manufacturing apparatus according to claim 1, wherein the press unit heats the laminate while compressing the laminate. The electrode assembly manufacturing apparatus according to claim 1, wherein the side sealing unit presses the laminate in a direction perpendicular to the pressing direction of the press unit. The method according to claim 1, wherein the press unit includes a pair of pressing blocks,
An electrode assembly manufacturing apparatus in which the pair of pressurizing blocks are moved in directions facing each other to pressurize the laminate. The method of claim 6, wherein the pair of pressure blocks each include a pressure surface,
The pressing surface is in contact with a surface facing the laminate, and when the pressing surface compresses the laminate, the surface facing the laminate is provided as a flat surface. The electrode assembly manufacturing apparatus according to claim 6, wherein the press unit includes a press heater that heats a pair of press blocks. The method according to claim 6, wherein each pressing block of the press unit each includes a flat pressing surface, and the pressing surface of the pressing block is provided to be longer than the width and length of the laminate. In claim 1,
The first electrode supply unit temporarily fixes the first electrode and a first electrode seating table for seating the first electrode before the first electrode is stacked on the stack table, and is temporarily fixed to the first electrode seating table. and a first transfer head that transfers the first electrode to the stack table during processing on the stack table,
The second electrode supply unit temporarily fixes the second electrode and a second electrode seating table for seating the second electrode before the second electrode is stacked on the stack table, and is temporarily fixed to the second electrode seating table. An electrode assembly manufacturing apparatus comprising a second transfer head that transfers the second electrode to the stack table during a process on the stack table. The electrode assembly manufacturing apparatus according to claim 10, wherein the first transfer head and the second transfer head each include a vacuum device for temporarily fixing the first electrode and the second electrode. In claim 10,
Further comprising a rotating part that rotates the stack table,
The first electrode supply part is provided on one side of the rotating part, and the second electrode supply part is provided on the other side opposite to one side of the rotating part,
The rotation unit rotates the stack table to one side so that the stack table faces the first transfer head when the first electrode is stacked, and the rotation unit rotates the stack table to face the second transfer head when the second electrode is stacked. An electrode assembly manufacturing device that rotates the stack table to the other side. The electrode assembly manufacturing apparatus of claim 12, wherein the rotation unit alternately rotates the stack table in the direction of the first electrode supply unit and the direction of the second electrode supply unit. A first electrode, a first separator, a second electrode, and a second separator are supplied and stacked to form a laminate in which the first separator folded in a zigzag shape is disposed between the first electrode and the second electrode. The upper and lower surfaces of the laminate are formed. and winding a second separator positioned on at least one pair of opposing sides,
Heating and pressurizing the laminate in the direction in which the laminate is laminated; and
A side sealing step of heating at least one side of the laminate to bond the second separator located on at least a pair of opposing sides of the laminate to the side of the laminate,
In the side sealing step, both sides of the laminate are pressed toward the center of the laminate in a direction perpendicular to the side, and at least one side of the laminate is compressed with a pressure of 0.1 MPa to 1.5 MPa. . The method of claim 14, wherein the side sealing step presses at least one side of the laminate at a temperature of 100°C to 200°C for 10 seconds or less.
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