WO2017213336A1 - Method for manufacturing electrode assembly having irregular structure, and irregular electrode assembly - Google Patents

Abstract

The present invention provides a manufacturing method capable of fundamentally resolving a problem caused by an inflow of foreign matter into a separator by cutting the separator into a desired shape in a state in which a plurality of separators are bonded so as to reduce the generation of foreign matter. The present invention also provides an electrode assembly having an irregular structure applicable to devices with various designs.

Description

A method for manufacturing an electrode assembly having an amorphous structure and an amorphous electrode assembly

This application claims the benefit of priority based on Korean Patent Application No. 10-2016-0070655 filed on June 8, 2016, and all the contents disclosed in the literature of that Korean patent application are incorporated as part of this specification.

The present invention relates to a method for producing an electrode assembly having an amorphous structure and to an amorphous electrode assembly.

As technology (Information Technology) technology has developed remarkably, the spread of various portable information and communication devices has made it possible to develop the ubiquitous society, which is capable of providing high quality information services regardless of time and place.

Lithium battery cells occupy an important position on the basis of the development to such a ubiquitous society. Specifically, lithium battery cells capable of charging and discharging are not only widely used as energy sources for wearable electronic devices worn on a wireless mobile device or body, but also for air pollution of conventional gasoline vehicles and diesel vehicles using fossil fuel. It is also used as an energy source for electric vehicles and hybrid electric vehicles, which are being proposed as a solution to the problem.

As described above, as devices to which lithium battery cells are applied are diversified, lithium battery cells are diversified to provide outputs and capacities suitable for the devices to which they are applied. In addition, there is a strong demand for miniaturization.

On the other hand, lithium battery cells are manufactured in consideration of the size and shape of the device using them as a power source, and in recent years, the product is used in a variety of lithium battery cells, so that it is applicable to a variety of devices having a curved or curved, rectangular Apart from the structure, at least five polygonal structures or geometrically irregular designs are manufactured.

1 and 2 illustrate an example electrode assembly of one exemplary amorphous structure.

1 and 2, the electrode assembly 10 has a structure in which an anode 2, a separator 3a, a cathode 6, a separator 3b, and an anode 4 are sequentially stacked and planarized. It consists of hexagonal structure with six internal angles.

It has four internal angles in plan view, and the overall hexahedral shape is compared with the rectangular structure, and the shape is more complicated than the rectangular structure while having more internal angles in the plane. It may be referred to as atypical.

Accordingly, in the present invention, the electrode structure shown in FIG. 1 is defined as an electrode assembly having an amorphous structure under this concept.

Referring again to the atypical electrode assembly 10 shown in FIGS. 1 and 2, each of the electrodes 2, 4, and 6 has a shape in which a lower edge forms an oblique line with respect to the direction leader lines x and y. The separators 3a and 3b have a larger size than the electrodes 2, 4 and 6 due to contact between the electrodes 2, 4 and 6 and blocking of foreign substances.

In the manufacturing of the electrode assembly, the separators 3a and 3b are stacked with the electrodes 2, 4 and 6 so as to correspond to the shape of the bottom edges of the electrodes 2, 4 and 6. Cutting along the imaginary cutting line (C), the separator pieces generated at this time may be introduced into the positive electrode (2, 4) or the negative electrode (4) by the static electricity can reduce the quality of the electrode.

In order to solve this problem, the foreign material must be checked with the naked eye and the foreign material of the separator must be removed through manpower. However, the structure of the electrode may be damaged in this process, which may impair the quality of the electrode assembly.

Therefore, there is a high demand for a method for more stably manufacturing an amorphous electrode assembly, and an electrode assembly applicable to more various devices as an amorphous structure.

The present invention aims to solve the problems of the prior art as described above and the technical problems that have been requested from the past.

Specifically, an object of the present invention is to provide a manufacturing method that can fundamentally solve the problems caused by the introduction of foreign matter to the separator by cutting in a desired form in a state in which a plurality of separation membranes are bonded to reduce the occurrence of foreign matter.

It is still another object of the present invention to provide an amorphous electrode assembly whose structure is stable.

The manufacturing method according to the present invention for achieving this object is

A method of manufacturing an electrode assembly having an amorphous structure consisting of at least six outer peripheries on a plane,

(a) between a first electrode and a second electrode, a first separator having a plane area of 110% to 150% of any one of these electrodes, except for a portion protruding beyond the first electrode and the second electrode; Laminating the separator and the electrodes;

(b) a second separator between the second electrode and the third electrode with a second separator having a plane area of 110% to 150% relative to any one of these electrodes, except for a portion protruding beyond the second electrode and the third electrode; Laminating the electrodes;

(c) Among the outer peripheries of each of the first separator and the second separator, the outer peripheral surfaces of the first separator and the second separator adjacent to the protruding outer periphery are formed at an angle of 30 to 60 degrees with respect to the outer periphery of the adjacent electrode. Lamination process;

(d) cutting the laminated outer circumferential surfaces such that an outer circumference of 0 degrees to 10 degrees with respect to the outer circumference of the electrode of the step (c) is formed on the first and second separators. It features.

That is, in the manufacturing method of the present invention, the first separator and the second separator are not cut, but are bonded to each other by lamination and fusion, that is, the fiber tissue of the separator is cut in a cured state. The degree of foreign matter generation can be significantly reduced, and due to the fact that the separator in which the fibrous structure is cured is not easily induced by static electricity, even if a small amount of foreign matter is generated, the inevitable phenomenon of the foreign material adsorbed to the electrode can be considerably alleviated.

In particular, since the static electricity is hardly involved in the electrode adsorption of foreign matters, it is also understood as a feature of the present invention that foreign matters can be removed from the electrode surface by a simple method such as blowing.

In one specific example, in the above processes (a) to (c), the first separator and the second separator have a planar rectangular structure, and in step (d), the first separator and the second separator have a planar amorphous structure. Can be.

That is, in the present invention, the first and second separators having a rectangular shape are first cut into a shape substantially corresponding to the electrode in the process (d) and processed into an amorphous structure, and the cutting is separated into each of the first separator and the second separator. It should be noted that the bar is processed in a state in which a predetermined portion is formed in one, and the cutting process is easy and the manufacturing processability is excellent while the generation of foreign matter is reduced, so that a good electrode assembly can be manufactured.

The lamination as defined in the present invention means a process of applying heat to the surfaces of the separators and the electrodes in surface contact, and the separators and the electrodes in contact with each other by mutually joining the surfaces thereof.

The separator is composed of an insulating thin polymer membrane having high ion permeability and mechanical strength, the pore diameter is generally 0.01 ~ 10 ㎛, thickness may be generally 5 ~ 300 ㎛. In this state, when two or more separators made of polymer are bonded by heat, the fiber structure thereof becomes firm, so that the phenomenon of falling into fine pieces during cutting may be reduced.

As a polymer which comprises the said separator, For example, Olefin type polymers, such as a chemical resistance and hydrophobic polypropylene; Sheets or non-woven fabrics made of glass fibers or polyethylene, etc. may be used.

In some cases, the separation membrane may be formed of an organic / inorganic hybrid porous safety-reinforcing separator (SRS) membrane.

Since the SRS membrane does not generate high temperature heat shrinkage due to the heat resistance of the inorganic particles, even if the electrode assembly is penetrated by the needle conductor, it is possible to maintain the elongation of the safety separator.

The SRS separator may have a structure in which an inorganic layer and a binder polymer are coated with an active layer component on a polyolefin-based separator substrate.

Such an SRS separator may have a uniform pore structure formed by an interstitial volume between inorganic particles as an active layer component in addition to the pore structure included in the separator substrate itself, and the pores may be formed on the outside of the electrode assembly. Not only can the shock be considerably alleviated, the smooth movement of lithium ions through the pores, and a large amount of electrolyte can be filled to show a high impregnation rate, thereby improving battery performance.

The separator substrate and the active layer are present in a form in which the pores of the surface of the polyolefin-based separator substrate and the active layer are entangled with each other (anchoring), so that the separator substrate and the active layer may be physically firmly bonded, wherein the separator substrate and the active layer are physically In consideration of the bonding force and the pore structure present on the separation membrane, it may have a thickness ratio of 9: 1 to 1: 9, and in detail, may have a thickness ratio of 5: 5.

In the SRS separator, one of the active layer components formed on the surface of the polyolefin-based separator substrate and / or a part of the pores of the substrate is an inorganic particle commonly used in the art.

The inorganic particles may serve as a kind of spacer capable of forming micro pores by allowing the formation of empty spaces between the inorganic particles and maintaining a physical form. In addition, since the inorganic particles generally have a property that physical properties do not change even at a high temperature of 200 degrees Celsius or more, the formed organic / inorganic composite porous film has excellent heat resistance.

The inorganic particles are not particularly limited as long as they are electrochemically stable. That is, the inorganic particles that can be used in the present invention are not particularly limited as long as the oxidation and / or reduction reactions do not occur in the operating voltage range of the battery to be applied (for example, 0 to 5 V on the basis of Li / Li +). In particular, in the case of using the inorganic particles having the ion transfer ability, since the ion conductivity in the electrochemical device can be improved to improve the performance, it is preferable that the ion conductivity is as high as possible. In addition, when the inorganic particles have a high density, it is not only difficult to disperse during coating, but also has a problem of weight increase during battery manufacturing, and therefore, it is preferable that the density is as small as possible. In addition, in the case of an inorganic material having a high dielectric constant, it is possible to contribute to an increase in the degree of dissociation of an electrolyte salt such as lithium salt in the liquid electrolyte, thereby improving the ionic conductivity of the electrolyte solution.

For the above reasons, the inorganic particles may be at least one selected from the group consisting of (a) inorganic particles having piezoelectricity and (b) inorganic particles having lithium ion transfer capability.

The piezoelectric inorganic particles are insulators at normal pressure, but when they are applied at a certain pressure, they mean materials having electrical properties through electrical structure change, and exhibit dielectric constants of 100 or more, as well as constant pressures. When tension or compression is applied, electric charge is generated so that one side is positively charged and the other side is negatively charged, thereby generating a potential difference between both surfaces.

In the case of using the inorganic particles having the above characteristics as the porous active layer component, the positive electrode and the negative electrode may not directly contact due to the inorganic particles coated on the separator when the internal short circuit of both electrodes occurs due to an external impact such as a needle conductor. In addition, due to the piezoelectricity of the inorganic particles, the potential difference in the particles is generated, which results in electron transfer between the two electrodes, that is, a minute current flow, thereby reducing the voltage of the gentle battery and thereby improving safety.

Examples of the inorganic particles having piezoelectric properties include BaTiO ₃ , Pb (Zr, Ti) O ₃ (PZT), Pb _{1 -} xLa _x Zr _1-y Ti _y O ₃ (PLZT), PB (Mg ₃ Nb _2/3 ) One or more selected from the group consisting of O ₃ -PbTiO ₃ (PMN-PT) and hafnia (HfO ₂ ), but is not limited thereto.

The inorganic particles having a lithium ion transfer capacity refers to inorganic particles containing lithium elements but having a function of transferring lithium ions without storing lithium, and the inorganic particles having lithium ion transfer ability are present in the particle structure. Since lithium ions can be transferred and moved due to a kind of defect, the lithium ion conductivity in the battery is improved, thereby improving battery performance.

Examples of the inorganic particles having the lithium ion transfer ability 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) _x O _y series glass (0 <x <4, 0 <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 <z <7) may be one or more selected from the group consisting of glass, but is not limited thereto.

The composition ratio of the inorganic particles and the binder polymer as the active layer component is not particularly limited, but may be controlled within a range of 10:90 to 99: 1% by weight, and preferably 80:20 to 99: 1% by weight. If the ratio is less than 10: 90% by weight, the polymer content becomes excessively large, resulting in a decrease in pore size and porosity due to a decrease in the void space formed between the inorganic particles, resulting in deterioration of final cell performance. When the ratio is exceeded, the polymer content is too small, and thus the mechanical properties of the final organic / inorganic composite porous separator may be degraded due to the weakening of the adhesion between the inorganic materials.

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

In the organic / inorganic composite porous separator, the substrate coated with a mixture of the inorganic particles and the binder polymer as the active layer component may be a polyolefin-based separator commonly used in the art. Examples of the polyolefin-based separator components include high density polyethylene, linear low density polyethylene, low density polyethylene, ultra high molecular weight polyethylene, polypropylene, or derivatives thereof.

In one specific example, the first electrode and the third electrode may be an anode or a cathode, and the second electrode may have a different polarity than the first electrode and the third electrode.

Therefore, the electrode assembly manufactured by the method of the present invention, the A-type bi-cell structure in which the positive electrode, the separator, the negative electrode, the separator positive electrode is sequentially stacked, or the C-type bicell in which the negative electrode, the separator, the positive electrode, the separator negative electrode is sequentially stacked It may be a structure.

The A-type bi-cell generally refers to a bi-cell in which the electrode of the electrode located in the middle layer is an anode, and the C-type bi-cell is a cathode of the electrode located in the middle layer. Refers to a bicell.

In addition, the manufacturing method according to the present invention may further include a process of manufacturing a modified bicell-type electrode assembly including a separator as well as the A-type and C-type bicells.

Specifically, in the process (a) of the manufacturing method, the third separator is further laminated on an opposite surface of the surface on which the first separator is laminated, and in the process (c), the outer circumferential surface of the third separator is The method may further include laminating the outer circumferential surfaces of the first separator and the second separator.

Through this process, the electrode assembly may have a structure in which a third separator, a first electrode, a first separator, a second electrode, a second separator, and a third electrode are sequentially stacked.

Similarly, in the process (b) of the manufacturing method, the third electrode is further laminated on the opposite surface of the surface on which the second separator is laminated, and in the process (c), the outer circumferential surface of the fourth separator is The method may further include laminating the outer circumferential surfaces of the first separator and the second separator.

Through this process, the electrode assembly may have a structure in which a first electrode, a first separator, a second electrode, a second separator, a third electrode, and a fourth separator are sequentially stacked.

In some cases, both the third separator and the fourth separator may be laminated on the first electrode and the third electrode, respectively, and in this state, the third separator and the fourth separator may be further laminated on the outer peripheral surfaces of the first separator and the second separator.

In the electrode assembly manufactured according to the above embodiment, the third separator or the fourth separator is positioned on the outermost electrode, and when the needle conductor penetrates, the third separator or the fourth separator located at the outermost portion is formed with the acicular conductor. Stretching together prevents the mutually opposite electrodes from directly conducting through the needle conductor.

The present invention also provides an electrode assembly having an amorphous structure applicable to devices of various designs.

Specifically, the electrode assembly has a structure in which n amorphous electrodes (n≥3) composed of at least six outer peripheries in a plane are stacked together with n, n-1, or n + 1 separators. Each of the separators has an area of 110% to 150% of the area of the electrode so as to protrude outward from the outer periphery of the adjacent electrode;

Among the outer peripheries of each of the separators, the outer periphery of the separators adjacent to the protruding periphery is formed at an angle of 30 degrees to 60 degrees with respect to the periphery of the adjacent electrode, and is 0 to the periphery of the electrode. It characterized in that it comprises a junction outer periphery of the structure cut to achieve 10 degrees.

That is, the electrode assembly according to the present invention is formed of six or more polymorphs in a plane, and thus it can be seen that the shape is applicable to a device such as a polygon or a geometric structure, and also a circular or curved surface, which is out of a general rectangular design.

In addition, the separators are cut to correspond to the shape of the at least one electrode, but as described above, the separator portions that do not correspond to the outer periphery of the electrode are cut to be substantially parallel to the outer periphery of the electrode. In this case, the foreign matters that are separated from the separator are significantly reduced, and thus, the electrode assembly has a stable structure without deterioration of electrode performance or deterioration due to foreign matters because there is almost no foreign matter on the electrodes.

In one specific example, n, n-1, or n + 1 separators may be bonded to each other around the junction.

In such a structure, an edge portion of the electrodes positioned between the separators sharing the outer circumference of the junction may be supported while being surrounded by the outer circumference of the junction.

Thus, if the electrode assembly of the present invention is expanded to the concept of a battery cell mounted in the battery case, the outer surface of the electrode assembly consisting of the corner portion is relatively small surface area is applied a considerable pressure when the impact is applied, the battery case in this process The electrodes of opposite polarities may be in contact with each other while being strongly rubbed with the inner surface, but the structure, that is, the structure in which the n, n-1, or n + 1 separators are bonded to each other is the inner surface of the battery case. The previous problem can be solved by alleviating the friction degree of the edge portion against.

Alternatively, n, n-1, or n + 1 separators may be separated from each other around the junction.

The electrode assembly according to the present invention may have a structure in which six or more polymorphic electrodes are stacked on a planar bar, and may have six or more polymorphic structures on a plane, and may include two or more bonding outer peripheries.

In one specific example, the electrode assembly may have a second electrode having a different polarity between the first electrode and the third electrode having the same polarity, and the first electrode, the second electrode, and the third electrode may have the same shape. . However, the size of these electrodes, for example, the thickness or the planar area may be different from each other.

The first electrode and the third electrode may be an anode or a cathode, and the second electrode may have a different polarity from that of the first electrode and the third electrode.

Herein, when n is 3 and the separator is two, the electrode assembly may have a stacked structure in order of an electrode, a separator, an electrode, a separator, and an electrode.

In contrast, when n is 3 and the separator is 3, the electrode assembly may have a stacked structure in order of a separator, an electrode, a separator, an electrode, a separator, and an electrode.

In addition, when n is 3 and the separator is four, the electrode assembly may have a stacked structure in order of a separator, an electrode, a separator, an electrode, a separator, an electrode, and a separator.

Such an electrode stack structure is commonly referred to as a bicell, and more specifically, when the polarity of the electrode positioned in the intermediate layer is an anode, it may be defined as an A-type bicell in a broad sense, and is located in the intermediate layer. When the polarity of the electrode is a cathode, it can be defined as a C-type bicell in a broad sense.

In one specific example, each of the outer periphery of the electrode may be interconnected to form an internal angle of less than 60 degrees to less than 270 degrees with an adjacent outer periphery, in detail, may be interconnected to form an internal angle of more than 90 degrees less than 180 degrees. have.

On the other hand, the electrodes may each include an electrode tab protruding outward from the outer periphery located in the same direction.

In this case, when the electrode assembly has a structure in which the first electrode, the second electrode, and the third electrode are stacked, the electrode tabs of the first electrode and the third electrode are formed to form the first electrode terminal of the electrode assembly in a state where the electrode tabs are overlapped up and down. The electrode tab of the second electrode forms a second electrode terminal of the electrode assembly at a position spaced from at least the first electrode terminal.

That is, although the electrode tabs of the first electrode and the second electrode and the electrode tab of the second electrode protrude outward from the outer periphery located in the same direction, they may be spaced apart within a range that does not contact each other.

In contrast, the first electrode and the third electrode include electrode tabs protruding outward from the outer periphery positioned in the same direction, and the second electrode is different from the outer periphery where the electrode tabs of the first and third electrodes are located. It may include an electrode tab protruding outwardly from the outer periphery.

Accordingly, in the structure in which the first electrode, the second electrode, and the third electrode are stacked, the first electrode terminal is formed at the same outer periphery of the electrode assembly with the electrode tabs of the first electrode and the third electrode overlapping up and down side by side. The electrode tab of the second electrode may form the second electrode terminal of the electrode assembly at the outer periphery of a position different from the outer periphery of the first electrode terminal.

Such a structure is provided by a device in which a first electrode terminal and a second electrode terminal are spaced apart from each other to apply a current to the first electrode terminal and the second electrode terminal in an activation process of the battery cell, that is, an initial charge / discharge process. They may not interfere with each other. The interference may be, for example, interference by a magnetic field formed when a current flows through an electrode terminal.

Furthermore, in the above structure, since the first electrode terminal and the second electrode terminal are formed at outer peripheries in different directions, an electrical connection structure to each of these terminals can be achieved in different directions, and because of this, It is possible to implement the connection structure with the circuit that the electrode assembly can be electrically connected in more various forms.

The electrode assembly of the present invention composed of such electrodes consists of a polygonal structure having N internal angles (N ≧ 6) in plan view, and may be formed of left and right and / or vertically symmetrical structures.

In contrast, the electrode assembly may have a polygonal structure having N internal angles (N ≧ 6) in a planar shape, and may have a left, right, and / or up and down asymmetrical structure.

The present invention also provides a secondary battery including at least one electrode assembly.

Although the type of the secondary battery is not particularly limited, specific examples thereof include lithium ion (Li-ion) batteries, lithium polymer (Li-polymer) batteries having advantages such as high energy density, discharge voltage, and output stability, Or a lithium secondary battery such as a lithium ion polymer battery.

In general, a lithium secondary battery is composed of a positive electrode, a negative electrode, a separator, and a lithium salt-containing nonaqueous electrolyte.

The positive electrode is prepared by, for example, applying a mixture of a positive electrode active material, a conductive material, and a binder to a positive electrode current collector, followed by drying, and optionally, a filler is further added to the mixture.

The positive electrode current collector is generally made to a thickness of 3 to 500 micrometers. Such a positive electrode current collector is not particularly limited as long as it has high conductivity without causing chemical changes in the battery. For example, the surface of stainless steel, aluminum, nickel, titanium, calcined carbon, or aluminum or stainless steel Surface treated with carbon, nickel, titanium, silver or the like can be used. The current collector may form fine irregularities on its surface to increase the adhesion of the positive electrode active material, and may be in various forms such as film, sheet, foil, net, porous body, foam, and nonwoven fabric.

The positive electrode active material may be a layered compound such as lithium cobalt oxide (LiCoO ₂ ), lithium nickel oxide (LiNiO ₂ ), or a compound substituted with one or more transition metals; Lithium manganese oxides such as Li _{1 + x} Mn _2-x O ₄ (where x is 0 to 0.33), LiMnO ₃ , LiMn ₂ O ₃ , LiMnO _2, and the like; Lithium copper oxide (Li ₂ CuO ₂ ); Vanadium oxides such as LiV ₃ O ₈ , LiFe ₃ O ₄ , V ₂ O ₅ , Cu ₂ V ₂ O ₇ and the like; Ni-site type lithium nickel oxide represented by the formula LiNi _{1 - x} M _x O ₂ , wherein M = Co, Mn, Al, Cu, Fe, Mg, B, or Ga, and x = 0.01 to 0.3; Formula LiMn _{2 - x} M _x O ₂ (wherein M = Co, Ni, Fe, Cr, Zn or Ta and x = 0.01 to 0.1) or Li ₂ Mn ₃ MO ₈ (wherein M = Fe, Co, Lithium manganese composite oxide represented by Ni, Cu or Zn); LiMn ₂ O _{4 in} which a part of Li in the formula is substituted with alkaline earth metal ions; Disulfide compounds; Fe ₂ (MoO ₄ ) ₃ and the like, but are not limited to these.

The conductive material is typically added in an amount of 1 to 30 wt% based on the total weight of the mixture including the positive electrode active material. Such a conductive material is not particularly limited as long as it has conductivity without causing chemical change in the battery, and examples thereof include graphite such as natural graphite and artificial graphite; Carbon blacks such as carbon black, acetylene black, Ketjen black, channel black, furnace black, lamp black, and summer black; Conductive fibers such as carbon fibers and metal fibers; Metal powders such as carbon fluoride powder, aluminum powder 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 and the like can be used.

The binder is a component that assists the bonding of the active material and the conductive material to the current collector, and is generally added in an amount of 1 to 30 wt% based on the total weight of the mixture including the positive electrode active material. Examples of such binders include polyvinylidene fluoride, polyvinyl alcohol, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene , Polypropylene, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene butylene rubber, fluorine rubber, various copolymers and the like.

The filler is optionally used as a component for inhibiting expansion of the positive electrode, and is not particularly limited as long as it is a fibrous material without causing chemical change in the battery. Examples of the filler include olefinic polymers such as polyethylene and polypropylene; Fibrous materials, such as glass fiber and carbon fiber, are used.

The negative electrode is manufactured by coating and drying a negative electrode active material on a negative electrode current collector, and optionally, the components as described above may optionally be further included.

The negative electrode current collector is generally made to a thickness of 3 to 500 micrometers. Such a negative electrode current collector is not particularly limited as long as it has conductivity without causing chemical change in the battery. For example, the surface of copper, stainless steel, aluminum, nickel, titanium, calcined carbon, copper or stainless steel Surface-treated with carbon, nickel, titanium, silver, and the like, aluminum-cadmium alloy, and the like can be used. In addition, like the positive electrode current collector, fine concavities and convexities may be formed on the surface to enhance the bonding strength of the negative electrode active material, and may be used in various forms such as a film, a sheet, a foil, a net, a porous body, a foam, and a nonwoven fabric.

As said negative electrode active material, For example, carbon, such as hardly graphitized carbon and graphite type carbon; Li _x Fe ₂ O ₃ (0 ≦ _x ≦ 1), Li _x WO ₂ (0 ≦ _x ≦ 1), Sn _x Me _{1 - x} Me ' _y O _z (Me: Mn, Fe, Pb, Ge; Me' Metal complex oxides such as Al, B, P, Si, Group 1, Group 2, Group 3 elements of the periodic table, halogen, 0 <x ≦ 1; 1 ≦ y ≦ 3; 1 ≦ z ≦ 8); Lithium metal; Lithium alloys; Silicon-based alloys; Tin-based alloys; 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 and the like can be used.

The electrolyte may be a lithium salt-containing non-aqueous electrolyte, and consists of a non-aqueous electrolyte and a lithium salt. As the nonaqueous electrolyte, nonaqueous organic solvents, organic solid electrolytes, inorganic solid electrolytes, and the like are used, but not limited thereto.

Examples of the non-aqueous organic solvent include N-methyl-2-pyrrolidinone, propylene carbonate, ethylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, and gamma Butyl lactone, 1,2-dimethoxy ethane, tetrahydroxy franc, 2-methyl tetrahydrofuran, dimethyl sulfoxide, 1,3-dioxorone, formamide, dimethylformamide, dioxolon , Acetonitrile, nitromethane, methyl formate, methyl acetate, phosphate triester, trimethoxy methane, dioxorone derivatives, sulfolane, methyl sulfolane, 1,3-dimethyl-2-imidazolidinone, propylene carbo Aprotic organic solvents such as nate derivatives, tetrahydrofuran derivatives, ethers, methyl pyroionate and ethyl propionate can be used.

Examples of the organic solid electrolytes include polyethylene derivatives, polyethylene oxide derivatives, polypropylene oxide derivatives, phosphate ester polymers, polyedgetion lysine, polyester sulfides, polyvinyl alcohols, polyvinylidene fluorides, Polymers containing ionic dissociating groups and the like can be used.

Examples of the inorganic solid electrolyte include Li ₃ N, LiI, Li ₅ NI ₂ , Li ₃ N-LiI-LiOH, LiSiO ₄ , LiSiO ₄ -LiI-LiOH, Li ₂ SiS ₃ , Li ₄ SiO ₄ , Nitrides, halides, sulfates and the like of Li, such as Li ₄ SiO ₄ -LiI-LiOH, Li ₃ PO ₄ -Li ₂ S-SiS ₂ , and the like, may be used.

The lithium salt is a good material to be dissolved in the non-aqueous electrolyte, for example, LiCl, LiBr, LiI, LiClO ₄ , LiBF ₄ , LiB ₁₀ Cl ₁₀ , LiPF ₆ , LiCF ₃ SO ₃ , LiCF ₃ CO ₂ , LiAsF _{6, LiSbF 6, LiAlCl 4,} CH 3 SO 3 Li, CF 3 SO 3 Li, (CF 3 SO 2) 2 NLi, chloroborane lithium, lower aliphatic carboxylic acid lithium, lithium tetraphenyl borate and imide have.

In addition, for the purpose of improving charge / discharge characteristics, flame retardancy, etc., for example, pyridine, triethyl phosphite, triethanolamine, cyclic ether, ethylene diamine, n-glyme, hexaphosphate triamide, Nitrobenzene derivatives, sulfur, quinone imine dyes, N-substituted oxazolidinones, N, N-substituted imidazolidines, ethylene glycol dialkyl ethers, ammonium salts, pyrroles, 2-methoxy ethanol, aluminum trichloride and the like may be added. have. In some cases, in order to impart nonflammability, a halogen-containing solvent such as carbon tetrachloride or ethylene trifluoride may be further included, and carbon dioxide gas may be further included to improve high temperature storage characteristics, and FEC (Fluoro-Ethylene) may be further included. Carbonate), PRS (Propene sultone) may be further included.

In one specific example, lithium salts such as LiPF ₆ , LiClO ₄ , LiBF ₄ , LiN (SO ₂ CF ₃ ) _2, and the like, may be prepared by cyclic carbonate of EC or PC, which is a highly dielectric solvent, and DEC, DMC, or EMC, which are low viscosity solvents. Lithium salt-containing non-aqueous electrolyte can be prepared by adding to a mixed solvent of linear carbonate.

 The present invention also provides a device including at least one of the battery cells.

The device may be, for example, an electronic device selected from the group consisting of wearable electronic devices, mobile phones, portable computers, smart phones, tablet PCs, smart pads, netbooks, light electronic vehicles (LEVs), and wearable electronic devices. It is not limited only to these.

Since the devices are known in the art, detailed description thereof is omitted herein.

1 and 2 are schematic diagrams of one exemplary amorphous electrode assembly;

3 is a flowchart of a manufacturing method according to one embodiment of the present invention;

4 and 5 are schematic views of an electrode assembly according to one embodiment of the present invention;

FIG. 6 is an enlarged vertical cross sectional view of the portion L of FIG. 4; FIG.

7 is a schematic view of an electrode assembly according to another embodiment of the present invention;

8 is a schematic view of an electrode assembly according to still another embodiment of the present invention;

9 is a schematic plan view of an electrode assembly according to another embodiment of the present invention;

10 is a schematic plan view of an electrode assembly according to another embodiment of the present invention;

11 is a schematic plan view of an electrode assembly according to another embodiment of the present invention.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings, but the scope of the present invention is not limited thereto.

3 is a flow chart of a manufacturing method according to one embodiment of the present invention.

In order to explain the manufacturing method according to the present invention in more detail based on the structure of the electrode assembly, the electrode assembly according to one embodiment of the present invention shown in Figs. do.

Referring to these figures together, the manufacturing method 100 according to the present invention for the electrode assembly 200, relative to these electrodes between the first electrode 210 and the second electrode 220 in the process (110). Intervening the first separator 202 and the electrodes with heat except for a portion protruding beyond the first electrode 210 and the second electrode 220 with a rectangular first separator 202 having a large planar area. .

In a subsequent process 120, the second electrode 220 is interposed between the second electrode 220 and the third electrode 230 with a rectangular second separator 204 having a relatively larger planar area than those of the electrodes. The second separator 204 and the electrodes are laminated as a row except for a portion protruding beyond the third electrode 230.

When the processes 110 and 120 are completed, as shown in FIG. 5, the lower portions of the first separator 202 and the second separator 204 protrude beyond the electrodes, as illustrated in FIG. 5. .

In the present invention, the angle (a) of 30 degrees to 60 degrees with respect to the outer periphery 208 of the adjacent electrode among the outer peripheries of each of the first separator 202 and the second separator 204 in the present invention. And the outer peripheral surfaces 260 of the first separation membrane 202 and the second separation membrane 204 adjacent to the outer peripheral edges 251 and 252 protruding from each other.

In this state, through the process 130, by laminating the outer peripheral surfaces 260, which are part of the protruding first separator 202 and the second separator 204 as heat, the outer peripheral surfaces protruding beyond the electrodes ( 260 is bonded to form an integral.

Subsequently, in step 140, the outer periphery 240, which is approximately 0 degrees to 10 degrees with respect to the outer periphery of the electrode 208, is formed in the first separator 202 and the second separator 204, The laminated outer peripheral surfaces 260 are cut along the virtual cutting line C.

Although not shown in FIG. 3, in the process 110, a third separator (not shown) may be additionally laminated on an opposite surface of the surface where the first separator 202 is laminated on the first electrode 210. In this case, the process 130 may further include a process in which the outer circumferential surface of the third separator is further laminated to the outer circumferential surfaces 260 of the first separator 202 and the second separator 204.

In addition, in a state in which the third separator is further laminated, the third separator may also be cut together with the first separator 202 and the second separator 204 through the process 140.

Similarly, a fourth separator (not shown) may be additionally laminated on an opposite surface of the surface on which the second separator 204 is laminated on the second electrode 220, and in this case, the process 130 may be performed in a fourth manner. The outer circumferential surface of the separator may further include laminating the outer circumferential surfaces 260 of the first separator 202 and the second separator 204.

In addition, in a state in which the fourth separator is further laminated, the fourth separator may also be cut together with the first separator 202 and the second separator 204 through the process 140.

As described above, in the manufacturing method of the present invention, the plurality of separators are not cut, but are bonded to each other by lamination and fusion, that is, the fiber tissues of the separators are cut in a cured state. Due to the fact that the separator in which the fibrous structure is cured is not easily induced by static electricity, the inevitable phenomenon that the foreign material is adsorbed to the electrode can be significantly alleviated even when a small amount of foreign material is generated.

4 and 5 are schematic views of an electrode assembly according to an embodiment of the present invention, Figure 6 is a vertical cross-sectional schematic of the L portion of FIG.

Referring to these drawings together, the electrode assembly 200 is a planar electrode consisting of at least six outer periphery of the first electrode 210, the second electrode 220, the third electrode 230, the first electrode A separator 202 and a second separator 204, and include a first electrode 210, a first separator 202, a second electrode 220, a second separator 204, and a third electrode 230. It consists of a stacked structure in order.

The first electrode 210, the second electrode 220, and the third electrode 230 have an amorphous structure having six outer peripheries and six internal angles, respectively, and the shapes thereof are all the same.

In addition, the first electrode 210, the second electrode 220, and the third electrode 230 each include electrode tabs 212, 222, and 232 protruding outward from the outer periphery positioned in the same direction.

 In a state where the first electrode 210, the second electrode 220, and the third electrode 230 are stacked, the electrode tabs 212 and 232 of the first electrode 210 and the third electrode 230 are arranged up and down side by side. The overlapping electrode tabs 212 and 232 having the same polarity form the first electrode terminal 206 of the electrode assembly 200.

The electrode tab 222 of the second electrode 220 forms a second electrode terminal of the electrode assembly 200 at a position spaced apart from at least the first electrode terminal 206.

Although not separately illustrated in the drawings, the first electrode terminal 206 and the second electrode terminal 222 may be combined with a current-carrying member such as an electrode lead by welding or soldering, respectively.

The first separator 202 and the second separator 204 have an area of approximately 130% of the planar surface of any one of the first electrode 210, the second electrode 220, and the third electrode 230. The electrode 210, the second electrode 220, and the third electrode 230 have substantially the same shape.

However, the first separator 202 and the second separator 204 have a first rectangular structure, and in a state in which the first separator 202 and the second separator 204 are stacked together with the electrodes 210, 220, and 230, the first separator 202 and the second separator 202 may be formed. Outer peripheral surfaces of the separation membranes 202 and 204 adjacent to the outer peripheral edge 208 protruding at an angle (a, a ') of approximately 30 to 60 degrees with respect to the outer peripheral edge of the adjacent electrode among the respective outer peripheral edges The fields 260 are bonded to each other, and in this state, the outer circumferential surfaces 260 joined along the imaginary cutting line C, which are 0 to 10 degrees with respect to the outer circumference 208 of the electrode, are cut. The electrode 210, the second electrode 220, and the third electrode 230 have a structure substantially the same shape.

The portions of the first separator 202 and the second separator 204 cut in the bonded state as described above are defined as the bonding outer periphery 240 in the present invention. In addition, the concept of the bonding outer periphery 240 is, as shown in FIG. (A) or a separator portion from the cut portion to the outer periphery of the adjacent electrode.

6, if the bonded outer circumferential surface is cut along the cutting line CC so that some of the remaining outer circumferential surface remains, the first separator 202 and the second separator 204 may be formed at the outer circumferential edge 240a of the bonding. Stay bonded to each other. In this structure, the corner portion of the second electrode 220 positioned between the separators 202 and 204 sharing the junction outer periphery 240a is supported by the junction outer periphery 240.

On the contrary, as shown in (ii) of FIG. 6, if the bonded outer circumferential surfaces are cut along the cutting line CC so as to be separated from each other, the first separator 202 and the second separator 204 are separated from each other at the outer circumferential junction. Exists in a closed state.

As described above, the electrode assembly according to the present invention is formed of six or more polymorphs in a plane, and it can be seen that the shape is applicable to a device such as a polygon or a geometric structure, and also a circular or curved surface, which is out of the general rectangular design. have.

In addition, the separators are cut to correspond to the shape of the at least one electrode, but as described above, the separator portions that do not correspond to the outer periphery of the electrode are cut to be substantially parallel to the outer periphery of the electrode. In this case, the foreign matters that are separated from the separator are significantly reduced, and thus, the electrode assembly has a stable structure without deterioration of electrode performance or deterioration due to foreign matters because there is almost no foreign matter on the electrodes.

7 is a schematic view of an electrode assembly according to another embodiment of the present invention.

Referring to FIG. 7, the electrode assembly 300 may be a first electrode 310, a second electrode 320, a third electrode 330, and a first separator, which are amorphous electrodes having at least six outer peripheries in plan view. 302, a second separator 304, and a sequence of the first electrode 310, the first separator 302, the second electrode 320, the second separator 304, and the third electrode 330. It consists of a laminated structure.

The first electrode 310, the second electrode 320, and the third electrode 330 have an amorphous structure having six outer peripheries and six internal angles, respectively, and the shapes thereof are all the same.

The first electrode 310 and the third electrode 330 include electrode tabs 312 and 332 protruding outward from the outer periphery positioned in the same direction, and the second electrode 320 includes the first electrode 310 and the first electrode 310. It includes an electrode tab 322 protruding outward from the outer periphery located in a different direction with respect to the outer periphery where the electrode tabs 312 and 332 of the three electrodes 330 are located.

Accordingly, in the structure in which the first electrode 310, the second electrode 320, and the third electrode 330 are stacked, the electrode tabs 312 and 332 of the first electrode 310 and the third electrode 330 may be formed. While the first electrode terminal 306 is formed at the same outer periphery of the electrode assembly 300 in a state where the upper and lower sides overlap, the electrode tab of the second electrode 320 has an outer periphery at which the first electrode terminal 306 is located. The second electrode terminal 322 of the electrode assembly 300 is formed at the outer periphery of the position different from the.

In this structure, the first electrode terminal 306 and the second electrode terminal 322 are spaced apart from each other so that the first electrode terminal 306 and the second electrode terminal ( By means of devices which respectively apply current to 322, they may not interfere with each other.

Furthermore, since the first electrode terminal 306 and the second electrode terminal 322 are formed at outer peripheries in different directions, an electrical connection structure to each of these terminals can be achieved in different directions, and in this respect Due to this, the connection structure of the electrode assembly 300 and the circuit which can be electrically connected thereto can be implemented in more various forms.

8 is a vertical cross-sectional view of three electrode assemblies according to still another embodiment of the present invention.

First, referring to the first form (i) of FIG. 8, the electrode assembly 400 may include a third separator 406, a first electrode 410, a first separator 402, a second electrode 420, and a second electrode. The separator 404 and the third electrode 430 are sequentially stacked.

The electrode assembly 500 according to the second aspect (ii) of FIG. 8 includes a first electrode 510, a first separator 502, a second electrode 520, a second separator 504, and a third electrode 530. ) And the fourth separator 508 are sequentially stacked.

The electrode assembly 600 according to the third aspect (iii) of FIG. 8 includes a third separator 606, a first electrode 610, a first separator 602, a second electrode 620, and a second separator 604. ), The third electrode 630 and the fourth separator 608 are sequentially stacked.

The electrode assemblies 400, 500, and 600 shown in these first (i), second (ii) and third (iii) commonly have additional separators on the outermost electrode. As an additional structure, when the needle conductor penetrates the electrode assembly in the direction of the outermost electrode, the third or fourth separator added to the outermost portion may be stretched along the needle conductor to surround the needle conductor surface. For this reason, the needle conductors can block the mutually opposite electrodes, for example, the first electrode and the second electrode, or the second electrode and the third electrode from being directly energized through the needle conductors.

To this end, the third and fourth separators added to the outermost portion may have a relatively thicker thickness than that of the first and second separators, and in detail, is about 1.5 to 3 times the thickness of the first or second separators. It may have a thickness of twice.

9 to 11 are schematic plan views of electrode assemblies according to still other embodiments of the present invention.

For convenience of description, when the electrode assemblies 700, 800, and 900 are viewed from the top or the bottom, the outer periphery of the separators 730, 830, and 930 forming the outermost part of the electrode assembly may be formed. In the present invention, the planar shape of the separator is the same as that of the electrode, and thus, the outer periphery of the electrode assembly may be understood as the outer periphery of the electrode and implemented according to the planar shape of the separator. Of course.

Accordingly, referring to FIG. 9, the electrode assembly 700 has a polygonal structure consisting of six outer peripheries 701, 702, 703, 704, 705, and 706 that are straight in a plane.

These outer periphery 701, 702, 703, 704, 705, 706 are connected to the adjacent outer periphery at an angle of more than 90 degrees to less than 160 degrees, respectively, the shape of the connection is an amorphous polygonal structure.

The electrode assembly 700 is also symmetrically with respect to the vertical axis P-P 'passing through its center in a plane, and has an up and down asymmetrical structure with respect to the horizontal axis H-H'.

The first electrode terminal 710 and the second electrode terminal 720 of the electrode assembly 700 protrude side by side at the same outer periphery.

10 schematically shows an electrode assembly according to another embodiment of the present invention.

Referring to FIG. 10, the electrode assembly 800 has a polygonal structure including eight outer peripheries 801, 802, 803, 804, 805, 806, 807, and 808 that are straight in a plane.

These outer periphery 801, 802, 803, 804, 805, 806, 807, 808 are connected to the adjacent outer periphery at an angle of more than 90 degrees to less than 150 degrees, respectively, the shape is connected to the amorphous polygonal structure .

The electrode assembly 800 also consists of left and right symmetry with respect to the vertical axis (P-P ') and the horizontal axis (H-H') passing through its center in a plane.

The first electrode terminal 810 and the second electrode terminal 820 of the electrode assembly 800 protrude side by side at the same outer periphery.

11 schematically illustrates an electrode assembly according to another embodiment of the present invention.

Referring to FIG. 11, the electrode assembly 900 has a polygonal structure including seven outer peripheries 901, 902, 903, 904, 905, 906, and 907 that are straight in a plane.

These outer peripheries 901, 902, 903, 904, 905, 906, and 907 are connected to adjacent outer peripheries at an angle of more than 90 degrees to less than 180 degrees, respectively, and the connected shapes are atypical polygonal structures.

The electrode assembly 900 is also asymmetrical with respect to the vertical axis (P-P ') passing through its center in a plane, and has a vertically asymmetrical structure with respect to the horizontal axis (H-H').

In addition, the first electrode terminal 910 and the second electrode terminal 920 of the electrode assembly 900 protrude outward from different outer peripheral surfaces.

Those skilled in the art to which the present invention pertains will be able to perform various applications and modifications within the scope of the present invention based on the above contents.

As described above, in the manufacturing method according to the present invention, the first separator and the second separator are not cut, but are bonded to each other by lamination and fusion, that is, the fiber tissue of the separators is cut in a cured state. Bar, the generation of fine foreign matters due to cutting can be significantly reduced, and since the separator in which the fibrous structure is cured is not easily induced by static electricity, even if a small amount of foreign matter is generated, the inevitable phenomenon that the foreign material is adsorbed on the electrode is quite significant. Can be mitigated.

In addition, the electrode assembly according to the present invention consists of six or more polymorphs in planar shape, and is formed in a shape applicable to a device such as a polygon or a geometric structure, and also a circular or curved surface, which is out of a general rectangular design.

Claims (19)

1. A method of manufacturing an electrode assembly having an amorphous structure consisting of at least six outer peripheries on a plane,

   (a) between a first electrode and a second electrode, a first separator having a plane area of 110% to 150% of any one of these electrodes, except for a portion protruding beyond the first electrode and the second electrode; Laminating the separator and the electrodes;

   (b) a second separator between the second electrode and the third electrode with a second separator having a plane area of 110% to 150% relative to any one of these electrodes, except for a portion protruding beyond the second electrode and the third electrode; Laminating the electrodes;

   (c) Among the outer peripheries of each of the first separator and the second separator, the outer peripheral surfaces of the first separator and the second separator adjacent to the protruding outer periphery are formed at an angle of 30 to 60 degrees with respect to the outer periphery of the adjacent electrode. Lamination process;

   (d) cutting the laminated outer circumferential surfaces such that an outer circumference of 0 degrees to 10 degrees with respect to the outer circumference of the electrode of the step (c) is formed in the first and second separators;

   Method comprising a.
2. The method of claim 1, wherein in the process (a), the first electrode is further laminated on an opposite surface of the surface on which the first separator is laminated, and in the process (c), the outer circumferential surface of the third separator is And lamination to the outer peripheral surfaces of the first separator and the second separator.
3. The method of claim 1, wherein in the process (b), the third electrode is further laminated on the opposite surface of the surface on which the second separator is laminated, and in the process (c), the outer circumferential surface of the fourth separator is formed in the first electrode. And further laminated to the outer peripheral surfaces of the separator and the second separator.
4. The method of claim 1, wherein the first electrode and the third electrode are an anode or a cathode, and the second electrode has a different polarity than the first electrode and the third electrode.
5. The method of claim 1, wherein the first separator and the second separator in the process (a) to (c) has a planar rectangular structure, and in the process (d), the first separator and the second separator in a planar amorphous structure Method characterized in that.
6. As an electrode assembly,

   N amorphous electrodes (n≥3) having at least six outer peripheries in a plane are stacked together with n, n-1, or n + 1 separators, and each of the separators is adjacent to each other. Has an area of 110% to 150% relative to the planar surface of the electrode to protrude outward beyond the outer periphery of the electrode;

   Among the outer peripheries of each of the separators, the outer periphery of the separators adjacent to the protruding periphery is formed at an angle of 30 degrees to 60 degrees with respect to the periphery of the adjacent electrode, and is 0 to the periphery of the electrode. Electrode assembly characterized in that it comprises a junction outer periphery of the structure cut to achieve 10 degrees.
7. The electrode assembly of claim 6, wherein each of the outer peripheries of the electrode is interconnected with an adjacent outer periphery at least 90 degrees to less than 180 degrees.
8. The electrode assembly of claim 6, wherein a second electrode having a different polarity is located between the first electrode and the third electrode having the same polarity, and the first electrode, the second electrode, and the third electrode have the same shape. Electrode assembly.
9. 7. The electrode assembly of claim 6, wherein the electrode assembly has a polygonal structure having N internal angles (N≥6) in a planar shape, and has a left and right and / or a vertical symmetrical structure.
10. 7. The electrode assembly of claim 6, wherein the electrode assembly has a polygonal structure having N internal angles (N≥6) in a planar shape, and has left, right, and / or vertically asymmetrical structures.
11. 8. The electrode assembly of claim 7, wherein each of the electrodes includes an electrode tab protruding outward from an outer periphery positioned in the same direction.
12. The method of claim 7, wherein the first electrode and the third electrode includes an electrode tab protruding outward from the outer periphery located in the same direction, the second electrode is located on the outer periphery where the electrode tab of the first electrode and the third electrode is located; And an electrode tab protruding outward from an outer periphery positioned in a different direction with respect to the electrode assembly.
13. The electrode assembly of claim 6, wherein n, n-1, or n + 1 separators are bonded to each other around the junction.
14. The electrode assembly of claim 6, wherein the electrode assembly includes two or more outer peripheries of the junction.
15. The electrode assembly of claim 6, wherein n is 3 and the separator is two, and the electrode assembly is stacked in order of an electrode, a separator, an electrode, a separator, and an electrode.
16. 7. The electrode assembly of claim 6, wherein n is 3 and the separator is three, and the electrode assembly is stacked in order of a separator, an electrode, a separator, an electrode, a separator, and an electrode.
17. 7. The electrode assembly of claim 6, wherein n is 3 and the separator is four, and the electrode assembly is stacked in order of a separator, an electrode, a separator, an electrode, a separator, an electrode, and a separator.
18. A secondary battery comprising at least one electrode assembly according to claim 6.
19. A device comprising the secondary battery according to claim 19.

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