Unit battery cell and battery cell comprising the same

Abstract

A unit cell according to an embodiment of the present application includes: separators and electrodes alternately stacked a predetermined number of times; a first adhesive portion positioned between the separators and the electrodes and made of a first adhesive component; and a second adhesive portion positioned between the separators and another separator and made of a second adhesive component, wherein a dispersity of the first adhesive component is greater than a dispersity of the second adhesive component.

Description

TECHNICAL FIELD

[0001] Cross Reference to Related Applications

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2021-0066460, filed on May 24, 2021, and Korean Patent Application No. 10-2022-0048386, filed on April 19, 2022, and the contents of these documents are incorporated herein as part of the present application.

[0003] The present disclosure relates to a unit battery cell and a battery cell including the same, and more particularly, to a unit battery cell configured to adhere electrodes and separators and separators using an adhesive composition instead of a conventional lamination using heat and pressure, and a battery cell including the same. BACKGROUND

[0004] As technology develops and the demand for mobile devices increases, the demand for batteries as an energy source is rapidly increasing. In particular, secondary batteries have attracted considerable attention as an energy source for power-driven devices such as electric bicycles, electric vehicles, and hybrid electric vehicles, and as an energy source for mobile devices such as mobile phones, digital cameras, notebook computers, and wearable devices.

[0005] Based on the shape of the battery case, such a secondary battery can be classified into a cylindrical battery in which an electrode assembly is installed in a cylindrical metal can, a prismatic battery in which an electrode assembly is installed in a prismatic metal can, and a pouch-type battery in which an electrode assembly is installed in a pouch-type case formed of an aluminum-made laminate sheet. Here, the electrode assembly installed in the battery case is a power-generating element, the structure of which includes a cathode, an anode, and a separator interposed between the cathode and the anode, and is capable of charging and discharging. The electrode assembly can be classified into a jelly-roll type electrode assembly configured to have a structure in which a long sheet type cathode and a long sheet type anode, in which active materials are coated, are wound in a state in which a separator is interposed between the cathode and the anode, and a stacked type electrode assembly configured to have a structure in which a plurality of cathodes and anodes are sequentially stacked in a state in which a separator is interposed between the cathode and the anode.

[0006] Among them, in particular, the pouch-type battery having a structure in which a stacked / folded type electrode assembly is installed in a pouch-type battery case formed of an aluminum-made laminate sheet has advantages such as low manufacturing cost, small weight, and easy deformation of shape, and thus, the amount of use thereof is gradually increasing.

[0007] Here, in the case of a stacked electrode assembly, it is generally manufactured by preparing unit cells in advance and then stacking a plurality of unit cells. More specifically, the unit cells in a state of being alternately stacked in the order of separator-anode-separator-cathode can be fixed to each other by applying heat and pressure through a stacking device.

[0008] However, after being alternately stacked in the order of separator-anode-separator-cathode, a portion of the separator or the electrode is pushed out of place before entering the stacking device or during the stacking process, which causes a problem of breakage or a difference in adhesion strength.

[0009] Therefore, it is necessary to develop a unit cell capable of preventing movement between an electrode and a separator and preventing deformation and breakage of the electrode and the separator. SUMMARY

[0010] TECHNICAL PROBLEM

[0011] An object of the disclosure is to provide a unit cell configured to adhere an electrode and a separator and a separator and a separator using an adhesive component instead of conventional lamination using heat and pressure, and a battery cell including the same.

[0012] The object of the disclosure is not limited to the above-described object, and other objects not described herein will be clearly understood by those skilled in the art from the following detailed description and accompanying drawings.

[0013] TECHNICAL SOLUTION

[0014] According to one embodiment of the disclosure, a unit cell includes a separator and an electrode alternately stacked in a predetermined number, a first adhesive portion positioned between the separator and the electrode and including a first adhesive component, and a second adhesive portion positioned between the separator and another separator and including a second adhesive component, wherein a dispersion degree of the first adhesive component is greater than a dispersion degree of the second adhesive component.

[0015] The first adhesive component can include at least one of an ethylene-vinyl acetate (EVA)-based material, an acrylic-based material, and an epoxy-based material, and the second adhesive component can include at least one of an ethylene-vinyl acetate (EVA)-based material, an acrylic-based material, an epoxy-based material, a polyolefin-based material, a rubber-based material, a polyamide-based material, and a polyurethane-based material.

[0016] The second adhesive component can include at least one of a polyolefin-based material, a rubber-based material, a polyamide-based material, and a polyurethane-based material.

[0017] The separator can include a lower separator and an upper separator, and the electrode can include a first electrode and a second electrode, wherein the lower separator, the first electrode, the upper separator, and the second electrode can be stacked in this order.

[0018] The first adhesive portion can be positioned at at least one location selected from between the first electrode and the lower separator, between the first electrode and the upper separator, and between the second electrode and the upper separator.

[0019] The second adhesive portion can be positioned between the upper separator and the lower separator.

[0020] The first adhesive portion and the second adhesive portion can each be formed as a pattern including a plurality of dots.

[0021] The plurality of dots can be spaced apart from each other.

[0022] According to another embodiment of the disclosure, there is provided an electrode assembly formed by alternately stacking the unit cells, the first adhesive portion including an adhesive pattern arranged in the same location between the electrode and the separator.

[0023] According to another embodiment of the disclosure, there is provided an electrode assembly formed by alternately stacking the unit cells, the first adhesive portion including an adhesive pattern arranged in a staggered form between the electrode and the separator.

[0024] According to one embodiment of the disclosure, there is provided a battery cell including an electrolyte solution and an electrode assembly in which the unit cells are alternately stacked.

[0025] The first adhesive portion can be dissolved in the electrolyte solution.

[0026] The first adhesive component can include at least one of an ethylene-vinyl acetate (EVA)-based material, an acrylic-based material, and an epoxy-based material, and the second adhesive component can include at least one of an ethylene-vinyl acetate (EVA)-based material, an acrylic-based material, an epoxy-based material, a polyolefin-based material, a rubber-based material, a polyamide-based material, and a polyurethane-based material.

[0027] The content of the first adhesive component and the second adhesive component can be 0.8 wt.% or more to 1.2 wt.% or less with respect to the content of the electrolyte solution.

[0028] The content of the first binder component can be 0.6 wt.% or more to 0.9 wt.% or less relative to the content of the electrolyte solution, and the content of the second binder component can be 0.1 wt.% or more to 0.45 wt.% or less relative to the content of the electrolyte solution.

[0029] The second binder component can include at least one of a rubber-based material, a polyamide-based material, and a polyurethane-based material.

[0030] The content of the second binder component can be 0.1 wt.% or more to 0.2 wt.% or less relative to the content of the electrolyte solution.

[0031] The electrolyte solution can include at least one of an organic liquid electrolyte, an inorganic liquid electrolyte, a solid polymer electrolyte, a gel-type polymer electrolyte, a solid inorganic electrolyte, and an inorganic molten electrolyte.

[0032] The battery cell has a zigzag shape by folding the separator.

[0033] According to another embodiment of the present disclosure, there is provided a method of manufacturing a unit cell, the method including the steps of: applying a first binder to a first face of an electrode or to an adjoining region of a first separator, or to both; applying the first binder to a second face of the electrode or to an adjoining region of a second separator, or to both, the second face of the electrode being located opposite the first face of the electrode; applying a second binder to a peripheral region of the first separator or to a peripheral region of the second separator, or to both; and forming at least a portion of a stack by stacking the electrode between the first separator and the second separator such that the first face of the electrode adjoins the adjoining region of the first separator and the second face of the electrode adjoins the adjoining region of the second separator, the stack being formed such that the peripheral region of each of the first separator and the second separator extends outward beyond an edge of the electrode, the peripheral regions of each of the first separator and the second separator facing each other without the electrode interposed therebetween, wherein the first binder is configured to have a greater degree of dispersibility in an electrolyte than the second binder.

[0034] The first binder can have a greater degree of dispersibility in the electrolyte than the second binder.

[0035] The peripheral region of each of the first and second separators can extend around a periphery of the respective first and second separators, such that each of the peripheral regions can encircle the abutment region of the respective first and second separators.

[0036] The first adhesive can include at least one of an ethylene-vinyl acetate (EVA)-based material, an acrylic-based material, and an epoxy-based material, and the second adhesive can include at least one of an ethylene-vinyl acetate (EVA)-based material, an acrylic-based material, an epoxy-based material, a polyolefin-based material, a rubber-based material, a polyamide-based material, and a polyurethane-based material.

[0037] The first and second adhesives can each be applied in a respective dot pattern, the dots being spaced apart from one another.

[0038] The dots in the dot pattern of the first adhesive can be arranged in a grid of rows and columns of dots.

[0039] According to another embodiment of the disclosure, there is provided a method of manufacturing a battery cell, the method including the steps of: forming a stack by alternately stacking the unit cells; and placing the stack and an electrolyte in a battery case.

[0040] The method of manufacturing a battery cell can further include dissolving at least a portion of the first adhesive into the electrolyte.

[0041] The electrolyte can be a solution including at least one of an organic liquid electrolyte, an inorganic liquid electrolyte, a solid polymer electrolyte, a gel-type polymer electrolyte, a solid inorganic electrolyte, and an inorganic molten electrolyte.

[0042] A total amount of the first adhesive in the battery case can be 0.6 wt.% to 0.9 wt.% of a total amount of the electrolyte in the battery case.

[0043] A total amount of the second adhesive in the battery case can be 0.1 wt.% to 0.45 wt.% of a total amount of the electrolyte in the battery case.

[0044] A total amount of the first and second adhesives in the battery case can be 0.8 wt.% to 1.2 wt.% of a total amount of the electrolyte in the battery case.

[0045] The total amount of the first adhesive in the battery case can be 0.6 wt.% to 0.9 wt.% of the total amount of the electrolyte in the battery case, and wherein the total amount of the second adhesive in the battery case can be 0.1 wt.% to 0.45 wt.% of the total amount of the electrolyte in the battery case.

[0046] The second adhesive can include at least one of a polyolefin-based material, a rubber-based material, a polyamide-based material, and a polyurethane-based material.

[0047] The total amount of the second adhesive in the battery case can be 0.1 wt.% to 0.2 wt.% of the total amount of the electrolyte in the battery case.

[0048] Advantageous Effects

[0049] According to embodiments, the unit cell and the battery cell including the same of the present disclosure are configured to adhere the electrode and the separator and the separator using an adhesive component instead of using conventional lamination using heat and pressure, thereby preventing movement between the electrode and the separator, and preventing deformation and breakage of the electrode and the separator.

[0050] Effects of the present disclosure are not limited to the above-mentioned effects, and other additional effects not described above can be clearly understood by those skilled in the art from the description of the appended claims. BRIEF DESCRIPTION OF DRAWINGS

[0051] Figure 1 is an exploded perspective view of a unit cell according to an embodiment of the present disclosure;

[0052] Figure 2 is a perspective view of a unit cell in which components of Figure 1 are combined;

[0053] Figure 3 is a sectional view taken along an A-A axis line of Figure 2 ;

[0054] Figure 4 is a top view of a battery cell according to another embodiment of the present disclosure;

[0055] Figure 5 is a graph showing a result of a dispersion degree of a content of an adhesive component included in a unit cell according to Figure 2 ;

[0056] Figure 6 is a view showing linear sweep voltammetry (LSV) of an adhesive component included in a unit cell of Figure 2 ;

[0057] Figure 7is a cross-sectional view illustrating an electrode assembly according to an embodiment of the disclosure; and

[0058] Figure 8 is a cross-sectional view illustrating an electrode assembly according to another embodiment of the disclosure. DETAILED DESCRIPTION

[0059] Hereinafter, various embodiments of the disclosure will be described in detail with reference to the accompanying drawings so as to be easily practiced by those skilled in the art. The disclosed embodiments can be modified in various different ways without departing from the spirit or scope of the disclosure.

[0060] Portions unrelated to the description will be omitted for clarity in describing the disclosure, and like reference numerals refer to like elements throughout the specification.

[0061] Further, the size and thickness of each element are arbitrarily shown in the drawings for convenience of description, and the disclosure is not necessarily limited to those shown in the drawings. In the drawings, the thickness of layers, regions, and the like is exaggerated for clarity. In the drawings, the thickness of some layers and regions is exaggerated for convenience of description.

[0062] Further, throughout the specification, when a portion is referred to as "including" a certain component, it means that the portion includes the stated component but does not exclude any other components unless explicitly described as the contrary.

[0063] Further, throughout the specification, when referred to as "planar", it means when the target portion is observed from the upper side, and when referred to as "cross-sectional", it means when the target portion is observed from the cross-sectional side of the vertical section.

[0064] Hereinafter, a unit battery according to an embodiment of the disclosure will be described.

[0065] Figure 1 is an exploded perspective view of a unit battery according to an embodiment of the disclosure. Figure 2 is a perspective view of a unit battery in which Figure 1 components of Figure 3 are combined. Figure 2 is a cross-sectional view taken along the A-A axis of

[0066] Referring to Figure 1 and Figure 2According to one embodiment of the present disclosure, the unit cell includes: separators 210 and 250 and electrodes 110 and 150 alternately stacked in a predetermined number; a first adhesive portion 310 positioned between the separators 210 and 250 and the electrodes 110 and 150 and including a first adhesive component; and a second adhesive portion 350 positioned between the separators 210 and 250 and other separators 210 and 250 and including a second adhesive component.

[0067] More specifically, the separators 210 and 250 include a lower separator 210 and an upper separator 250, and the electrodes 110 and 150 include a first electrode 110 and a second electrode 150, wherein the lower separator 210, the first electrode 110, the upper separator 250, and the second electrode 150 can be stacked in this order.

[0068] Here, the first electrode 110 can include a first electrode tab 115 protruding in one direction, and the second electrode 150 can include a second electrode tab 155 protruding in one direction. In one embodiment, as shown in FIGS. 1A and 1B, the stacking can be performed such that the upper separator 250 is positioned between the first electrode 110 and the second electrode 150, and the stacking can be performed such that the first electrode tab 115 of the first electrode 110 and the second electrode tab 155 of the second electrode 150 are positioned in opposite directions to each other. However, the present disclosure is not limited thereto, and a structure in which the first electrode tab 115 and the second electrode tab 155 are stacked to be positioned in the same direction can also be included in an embodiment of the present disclosure. Figure 1 and Figure 2 Here, the first electrode 110 and the second electrode 150 can each include an electrode current collector and an active material layer positioned on the electrode current collector. Here, the active material layer can be formed of an electrode component containing an electrode active material. More specifically, the first electrode 110 and the second electrode 150 can be a cathode and an anode. Here, the cathode can include a cathode current collector and an active material layer containing a cathode active material, and the anode can include an anode current collector and an active material layer containing an anode active material. In one embodiment, the first electrode 110 can be an anode, and the second electrode 150 can be a cathode, but the present disclosure is not limited thereto, and a case in which the first electrode 110 can be a cathode, and the second electrode 150 can be an anode can also be included in an embodiment of the present disclosure.

[0069] Here, the first electrode 110 and the second electrode 150 can each include an electrode current collector and an active material layer positioned on the electrode current collector. Here, the active material layer can be formed of an electrode component containing an electrode active material. More specifically, the first electrode 110 and the second electrode 150 can be a cathode and an anode. Here, the cathode can include a cathode current collector and an active material layer containing a cathode active material, and the anode can include an anode current collector and an active material layer containing an anode active material. In one embodiment, the first electrode 110 can be an anode, and the second electrode 150 can be a cathode, but the present disclosure is not limited thereto, and a case in which the first electrode 110 can be a cathode, and the second electrode 150 can be an anode can also be included in an embodiment of the present disclosure.

[0070] As for the anode active material, an anode active material of a lithium secondary battery well known in the art can be used, and as one embodiment, a material such as metallic lithium, a lithium alloy, petroleum coke, activated carbon, graphite, silicon, tin, a metal oxide, or other carbon can be used.

[0071] Further, in one embodiment, the positive active material can be selected from the group consisting of lithium cobalt-based oxides, lithium manganese-based oxides, lithium nickel-manganese-based oxides, lithium manganese-cobalt-based oxides, lithium nickel-manganese-cobalt-based oxides, and lithium iron phosphate, or can be a combination thereof or a composite oxide thereof.

[0072] The anode current collector or the cathode current collector is not particularly limited as long as it has high conductivity while not causing chemical changes in the battery, and, for example, copper, 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.

[0073] The separators 210 and 250 can separate the first electrode 110 and the second electrode 150 and provide a moving path for lithium ions. Further, the separators 210 and 250 include a lower separator 210 and an upper separator 250, and separators made of different or the same materials from each other can be applied as the lower separator 210 and the upper separator 250.

[0074] In one embodiment, the separators 210 and 250 can be used without particular limitation as long as they are generally used as separators in lithium secondary batteries. In particular, it is desirable for the separators to have low resistance to ion movement of an electrolyte solution and to be excellent in terms of a wetting ability of the electrolyte solution. Specifically, a porous polymer film made of a polyolefin-based polymer such as an ethylene homopolymer, a propylene homopolymer, an ethylene / butene copolymer, an ethylene / hexene copolymer, and an ethylene / methacrylate copolymer can be used alone, or a stacked structure having two or more layers thereof can be used.

[0075] Hereinafter, the first adhesive portion 310 and the second adhesive portion 350 included in the unit cell according to the embodiment of the disclosure will be mainly described.

[0076] Referring to Figure 1 and Figure 3 The first adhesive portion 310 can be positioned at at least one position selected from between the first electrode 110 and the lower separator 210, between the first electrode 110 and the upper separator 250, and between the second electrode 150 and the upper separator 250.

[0077] Accordingly, the first adhesive portion 310 can fix the first electrode 110 and the second electrode 150 to the lower separator 210 and / or the upper separator 250, respectively. That is, the first adhesive portion 310 can prevent movement between the electrodes 110 and 150 and the separators 210 and 250 and prevent deformation and breakage of the electrodes 110 and 150 and the separators 210 and 250.

[0078] Further, the second adhesive portion 350 can be positioned between the upper separator 250 and the lower separator 210. More specifically, the second adhesive portion 350 can be positioned between the end of the lower separator 210 and the end of the first electrode 110. Further, the second adhesive portion 350 can be provided between the end of the upper separator 250 and the end of the first electrode 110. In other words, the second adhesive portion 350 is positioned on the surface of the separators 210 and 250 which does not contact the first electrode 110, wherein the second adhesive portion 350 can be positioned along the periphery of the first electrode 110. Here, the second adhesive portion 350 can even be selectively positioned in the portion where the electrode tabs 115 and 155 protruding from the electrodes 110 and 150 are positioned.

[0079] Accordingly, the first electrode 110 is positioned between the lower separator 210 and the upper separator 250, and the lower separator 210 and the upper separator 250 can be fixed to each other by means of the second adhesive portion 350, thereby preventing the first electrode 110 from moving between the lower separator 210 and the upper separator 250. In other words, the second adhesive portion 350 fixes the lower separator 210 and the upper separator 250 to each other along the periphery of the first electrode 110, thereby limiting the space in which the first electrode 110 can move, thereby enabling the deformation and breakage of the first electrode 110 to be prevented.

[0080] In addition, the first adhesive portion 310 and the second adhesive portion 350 can form a pattern including a plurality of dots, respectively, as shown in FIGS. 1A and 1B. Figure 1 and Figure 3 More specifically, the plurality of dots can be spaced apart from each other. Here, if necessary, the spacing between the plurality of dots can be adjusted to be the same as or different from each other.

[0081] Accordingly, the first adhesive portion 310 and the second adhesive portion 350 can form the above-described pattern, whereby when an electrolyte solution is injected into the electrode assembly 1100( Figure 4 ) including a plurality of unit battery cells 100, there is an advantage in that the electrode assembly 1100( Figure 4 ) can be quickly impregnated. More specifically, since the plurality of dots are spaced apart from each other in the first adhesive portion 310 and the second adhesive portion 350, there is an advantage in that the electrolyte solution can flow between the plurality of dots. That is, according to the embodiment of the disclosure, the manufacturing time of the battery cell 1000( Figure 4 ) can be relatively shortened, and the yield can also be improved.

[0082] Further, the first adhesive portion 310 can include a first adhesive component, and the second adhesive portion 350 can include a second adhesive component. More specifically, the first adhesive portion 310 can block a lithium ion passage between the electrodes 110 and 150 and the separators 210 and 250. That is, it can be preferable that the first adhesive portion 310 include a material having a relatively high dispersibility or a high solubility in an electrolyte solution. Here, the dispersibility of the first adhesive component included in the first adhesive portion 310 can be equal to or greater than the dispersibility of the second adhesive component included in the second adhesive portion 350.

[0083] According to one embodiment, the first adhesive component included in the first adhesive portion 310 and the second adhesive component included in the second adhesive portion 350 can include a material having the same component. In one embodiment, the first adhesive component can include at least one of an ethylene-vinyl acetate (EVA)-based material, an acrylic-based material, and an epoxy-based material, and the second adhesive component can include at least one of an ethylene-vinyl acetate (EVA)-based material, an acrylic-based material, an epoxy-based material, a polyolefin-based material, a rubber-based material, a polyamide-based material, and a polyurethane-based material.

[0084] Further, according to another embodiment, the first adhesive portion 310 and the second adhesive portion 350 can include materials having different components from each other. More specifically, the first adhesive component and the second adhesive component can have different dispersing abilities from each other. In other words, the dispersibility of the first adhesive component can be greater than the dispersibility of the second adhesive component. In one embodiment, the first adhesive component can include at least one of an ethylene-vinyl acetate (EVA)-based material, an acrylic-based material, and an epoxy-based material, and the second adhesive component can include at least one of a polyolefin-based material, a rubber-based material, a polyamide-based material, and a polyurethane-based material. For example, when the first adhesive component is made of an acrylic material, it can be considered to exhibit a certain solubility in an electrolyte since the acrylic material includes an ester group.

[0085] Accordingly, the first adhesive component included in the first adhesive portion 310 can have a relatively same or higher dispersibility than the second adhesive component included in the second adhesive portion 350, whereby it can be dissolved between the electrodes 110 and 150 and the separators 210 and 250 when an electrolyte solution is injected into an electrode assembly 1100 including a plurality of unit cells 100 (see FIG. 1) (see FIG. 2). Figure 4 ) In this case, the first adhesive portion 310 positioned between the electrodes 110 and 150 and the separators 210 and 250 is dissolved in the electrolyte solution, and thus can not block a lithium ion passage between the electrodes 110 and 150 and the separators 210 and 250.

[0086] Referring to Figure 6 With the first adhesive composition included in the first adhesive portion 310 corresponding to the first position, the oxidation reaction was confirmed to occur at about 4.0 V according to the result of linear sweep voltammetry (LSV). This can cause a side reaction in the battery cell, which can be a factor in reducing the capacity and lifespan. Therefore, it is not preferable to use the second adhesive composition for the first adhesive portion 310. One of the reasons for forming the second adhesive portion 350 is to prevent the folding of the separator during the electrolyte injection process. When at least one of an ethylene-vinyl acetate material, an acrylic material, and an epoxy-based material is used as the first adhesive composition, and a polyolefin-based material, a rubber-based material, a polyamide-based material, and a polyurethane-based material are used as the second adhesive composition, the result shown in Table 1 can occur. Figure 6

[0087] The separator according to the embodiments described herein can be a ceramic-coated separator (CCS). In general, the separator has a base film and a coating layer formed on at least one surface of the base film, and the coating layer can include alumina powder and a binder to aggregate them. In a safety reinforced separator (SRS), a large amount of binder is coated on the surface of the coating layer, but in the CCS, the binder is not coated on the surface of the coating layer, or the binder content distributed on the surface can be very low compared to the SRS. For example, in the case of the CCS separator according to the present embodiment, the content of the binder coated on the surface of the coating layer of the separator can be about 3 wt% or less.

[0088] When the separator is a CCS, since the internal electrode included in the electrode assembly is transported in a non-fixed state, the alignment can be disturbed during the transportation. Of course, when the separator is a CCS, it is possible to fix by means of heat and pressure, but even after the formation of the electrode and the separator into a laminate, the alignment of the internal electrode can be disturbed in the process of transferring the electrode and the separator to the fixing device of heating and pressurization. In addition, there is a disadvantage in that an expensive separator having a high binder content must be used to attach the electrode and the separator by means of heat and pressure. On the other hand, according to the present embodiment, it is possible to increase the fixing force while preventing the alignment of the internal electrode from being disturbed during the transportation.

[0089] Figure 4 is a top view of a battery cell according to another embodiment of the present disclosure.

[0090] Referring to Figure 2 and Figure 4 ​According to another embodiment of the present disclosure, a battery cell 1000 includes an electrode assembly 1100, on which unit cells 100 are alternately stacked, and an electrolyte solution. Here, a first electrode tab 1150, on which the first electrode tab 115 of the unit cell 100 is stacked, and a second electrode tab 1550, on which the second electrode tab 155 is stacked, can be electrically connected to an electrode lead 3000, respectively. A lead film 4000 can be positioned above and / or below the electrode lead 3000.

[0091] Further, the electrode assembly 1100 is mounted within a battery case 120, in which the electrode assembly 1100 can be positioned together with the electrolyte solution within a receiving portion 2100 having a concave shape. Further, a sealing portion 2500 can be formed such that the peripheral surfaces of the battery case 2000 are heat-fused and sealed to each other.

[0092] In one embodiment, the electrolyte solution can include at least one of an organic liquid electrolyte, an inorganic liquid electrolyte, a solid polymer electrolyte, a gel-type polymer electrolyte, a solid inorganic electrolyte, an inorganic molten electrolyte, etc., but the present disclosure is not limited thereto and can include all electrolyte solutions commonly used in the art.

[0093] According to an embodiment of the present disclosure, the first adhesive portion 310 can be dissolved in the electrolyte solution. More specifically, a first adhesive ingredient included in the first adhesive portion 310 can be dissolved in the electrolyte solution. More preferably, the first adhesive ingredient included in the first adhesive portion 310 can be completely dissolved in the electrolyte solution.

[0094] Accordingly, in an embodiment of the present disclosure, the first adhesive portion 310 is dissolved in the electrolyte solution, so that a lithium ion passage between the electrodes 110 and 150 and the separators 210 and 250 can not be obstructed, and the battery performance of the battery cell can be improved.

[0095] Here, the content of the first adhesive ingredient and the second adhesive ingredient can be 0.8 wt.% or more to 1.2 wt.% or less, with respect to the content of the electrolyte solution. More specifically, the content of the first adhesive ingredient and the second adhesive ingredient can be 0.85 wt.% or more to 1.15 wt.% or less, with respect to the content of the electrolyte solution. The content of the first adhesive ingredient and the second adhesive ingredient can be 0.9 wt.% or more to 1.1 wt.% or less, with respect to the content of the electrolyte solution.

[0096] Accordingly, the battery cell 1000 according to the embodiment of the disclosure can include the first binder component and the second binder component in the above-described range, to be fixed between the electrodes 110 and 150 and the separators 210 and 250, whereby the first binder portion 310 and the second binder portion 350 can be easily dispersed and dissolved in the electrolyte solution even while preventing electrode misalignment.

[0097] In contrast, when the content of the first binder component and the second binder component is less than 0.8 wt% relative to the content of the electrolyte solution, the adhesive strength between the electrodes 110 and 150 and the separators 210 and 250 or between the lower separator 210 and the upper separator 250 can be excessively reduced due to the first binder portion 310 and the second binder portion 350. In addition, when the content of the first binder component and the second binder component exceeds 1.2 wt.% relative to the content of the electrolyte solution, the first binder portion 310 positioned between the electrodes 110 and 150 and the separators 210 and 250 is not easily dispersed and dissolved in the electrolyte solution, which can obstruct the lithium ion path, thereby generating a non-charging area.

[0098] In addition, the content of the first binder component can be 0.6 wt.% or more to 0.9 wt.% or less, and the content of the second binder component can be 0.1 wt.% or more to 0.45 wt.% or less. More specifically, the content of the first binder component can be 0.65 wt.% or more to 0.85 wt.% or less, and the content of the second binder component can be 0.15 wt.% or more to 0.4 wt.% or less. In one embodiment, the content of the first binder component can be 0.7 wt.% or more to 0.8 wt.% or less, and the content of the second binder component can be 0.15 wt.% or more to 0.35 wt.% or less.

[0099] Accordingly, the battery cell 1000 according to the embodiment of the disclosure can include the first binder component and the second binder component in the above-described range, to be fixed between the electrodes 110 and 150 and the separators 210 and 250, whereby the first binder portion 310 and the second binder portion 350 can be easily dispersed and dissolved in the electrolyte solution even while preventing electrode misalignment.

[0100] In contrast, when the content of the first binder component is less than 0.6 wt.% or greater than 0.9 wt.%, the adhesive strength between the electrodes and the first binder portion 310 is insufficient, which results in electrode misalignment, or, alternatively, the first binder portion 310 is not easily dispersed and dissolved in the electrolyte solution, which can obstruct the lithium ion path, thereby generating a non-charging area.

[0101] Further, when the content of the second binder component is less than 0.1 wt.% or greater than 0.45 wt.%, the adhesion strength between the lower separator 210 and the upper separator 250 is excessively reduced, or the content of the binder component of the second binder portion 350 is excessively large, thereby making the second binder portion 350 likely to deviate from the surface area that can be formed.

[0102] Further, when the second binder component includes at least one of a rubber-based material, a polyamide-based material, and a polyurethane-based material having a small dispersibility in the electrolyte solution, the content of the second binder component can be 0.1 wt.% or more to 0.2 wt.% or less with respect to the content of the electrolyte solution. More specifically, in this case, the content of the second binder component can be 0.12 wt.% or more to 0.18 wt.% or less with respect to the content of the electrolyte solution. In one embodiment, in this case, the content of the second binder component can be 0.14 wt.% or more to 0.16 wt.% or less with respect to the content of the electrolyte solution.

[0103] Accordingly, in the battery cell 1000 according to the embodiment of the disclosure, even if the dispersibility of the second binder component is relatively small, the second binder component having the content in the above range can be used to fix between the electrodes 110 and 150 and the separators 210 and 250, thereby the first binder portion 310 and the second binder portion 350 can be easily dispersed and dissolved in the electrolyte solution while preventing misalignment of the electrodes.

[0104] Unlike this, when the content of the second binder component is less than 0.1 wt.% or greater than 0.2 wt.%, there is a problem in that the adhesion strength between the lower separator 210 and the upper separator 250 is excessively reduced, or the content of the binder component of the second binder portion 350 is excessively large, which results in a reduction in dispersibility.

[0105] Hereinafter, the disclosure will be described with reference to more specific embodiments, but the scope of the right of the disclosure is not limited to the following embodiments for the purpose of illustration only.

[0106] <Experimental Example 1 - Measurement of dispersibility>

[0107] Based on an electrolyte solution in which 1M LiPF6 of a lithium salt is mixed in a ratio of EC:EMC=3:7, the dispersibility of an ethylene-vinyl acetate (EVA)-based material, an acrylic-based material, an epoxy-based material, a polyolefin-based material, a rubber-based material, a polyamide-based material, and a polyurethane-based material, which are binder components, was measured, respectively.

[0108] Here, the acrylic-based material is acResin 204UV available from BASF, the EVA-based material is Technomelt 4046 of Henkel, the epoxy-based material is Lotite EA608 of Henkel, the polyolefin-based material is Supra 502 of Henkel, the rubber-based material is 2802 dispomelt of Henkel, the polyamide-based material is HPX 002 of Henkel, and the polyurethane-based material is EH9702 of Fuller. In addition, Figure 5 is a dispersibility result of Technomelt 4046, in which the content of the adhesive component is increased from left to right, and the dispersibility is measured according to the content. As Figure 5 is shown in the rightmost result, it looks suspended at 1 wt.%, which is indicated as NG. In addition, experiments were performed on other materials in the same manner, and the results are shown in Table 1 below.

[0109] [Table 1]

[0110]

[0111] [Example 1]

[0112] LiNi 0.6 Mn 0.2 Co 0.2 O2 was used as a cathode active material, carbon black was used as a conductive material, and polyvinylidene fluoride (PVdF) was used as a binder, and NMP was added as a solvent to a mixture of the cathode active material: conductive material: binder in a weight ratio of 96:2:2 to prepare a cathode active material slurry. The cathode active material slurry was applied to an aluminum current collector, and then dried and rolled to manufacture a cathode.

[0113] Artificial graphite was used as an anode active material, carbon black was used as a conductive material, and an SBR emulsion aqueous solution was used as a binder, and water was added to a mixture of the anode active material: conductive material: binder in a weight ratio of 96:1:5 to prepare an anode active material slurry. The anode active material slurry was applied to a copper current collector, and then dried and rolled to manufacture an anode.

[0114] A slurry of Al2O3 and PVDF mixed in a weight ratio of 94:6 was applied to both sides (each thickness of 3 μm) of a substrate (thickness of 10 μm) made of polyethylene / polypropylene, and dried at 60°C to manufacture a separator. According to the position, the separator was a top separator and a bottom separator.

[0115] As an electrolyte solution, a solution in which 1M LiPF6 of a lithium salt was mixed in a ratio of EC:EMC=3:7 was added and prepared.

[0116] The lower separator, anode, upper separator, and cathode were alternately stacked in this order to manufacture a unit cell, wherein the first adhesive portion comprising acResin 250UV in an amount of 0.75 wt.% relative to the electrolyte solution was positioned between the separator and the anode and between the separator and the cathode, and the second adhesive portion comprising acResin 250UV in an amount of 0.25 wt.% relative to the electrolyte solution was positioned between the upper separator and the lower separator.

[0117] <Example 2>

[0118] A unit cell was manufactured in the same manner as Example 1, except that the first adhesive portion used a composition comprising Lotite EA608, which was different from Example 1.

[0119] <Example 3>

[0120] A unit cell was manufactured in the same manner as Example 1, except that the first adhesive portion used a composition comprising Technomelt 4046, which was different from Example 1.

[0121] <Example 4>

[0122] A unit cell was manufactured in the same manner as Example 1, except that the first adhesive portion used a composition comprising Supra 502, which was different from Example 1.

[0123] <Example 5>

[0124] A unit cell was manufactured in the same manner as Example 1, except that the first adhesive portion used a composition comprising Lotite EA608 and the second adhesive portion used a composition comprising Supra 502, which was different from Example 1.

[0125] <Example 6>

[0126] A unit cell was manufactured in the same manner as Example 1, except that the first adhesive portion used a composition comprising Technomelt 4046 and the second adhesive portion used a composition comprising Supra 502, which was different from Example 1.

[0127] <Example 7>

[0128] A unit cell was manufactured in the same manner as Example 1, except that the second adhesive portion used a composition comprising 2802dispomelt in an amount of 0.15 wt.% relative to the electrolyte solution, which was different from Example 1.

[0129] <Comparative Example 1>

[0130] A unit battery cell was manufactured in the same manner as in Example 1, except that, unlike Example 1, the first adhesive portion used a component having a content of 0.25 wt.% relative to the electrolyte solution, and the second adhesive portion used a component having a content of 0.75 wt.% relative to the electrolyte solution.

[0131] <Comparative Example 2>

[0132] A unit battery cell was manufactured in the same manner as in Example 1, except that, unlike Example 1, the first adhesive portion used a component having a content of 0.5 wt.% relative to the electrolyte solution, and the second adhesive portion used a component having a content of 0.25 wt.% relative to the electrolyte solution.

[0133] <Comparative Example 3>

[0134] A unit battery cell was manufactured in the same manner as in Example 1, except that, unlike Example 1, the second adhesive portion used a component having a content of 0.5 wt.% relative to the electrolyte solution.

[0135] <Comparative Example 4>

[0136] A unit battery cell was manufactured in the same manner as in Example 1, except that, unlike Example 1, the first adhesive portion used a component containing Supra 502, and the second adhesive portion used a component containing Supra 502.

[0137] <Comparative Example 5>

[0138] A unit battery cell was manufactured in the same manner as in Example 1, except that, unlike Example 1, the first adhesive portion used a component containing Supra 502.

[0139] <Experimental Example 2 - Measurement of Dispersion, Viscosity, and Ionic Conductivity>

[0140] For the battery cells manufactured in Examples 1 to 7 and Comparative Examples 1 to 5, the dispersion, viscosity, and ionic conductivity according to the content of the adhesive component contained in the first adhesive portion and the second adhesive portion relative to the content of the electrolyte solution were measured, respectively.

[0141] The dispersion was measured in the same manner as in Experimental Example 1, and the results are shown in Table 2 below.

[0142] The ionic conductivity was measured using an ionic conductivity measuring device of a Cond probe InLab 710 instrument (Mettler Toledo).

[0143] The spindle portion of the Brookfield DV2T LV TJ10 machine was replaced with a cone plate and CPA-40Z cone was applied to measure the viscosity at 10 rpm.

[0144] Here, if the lithium salt of 1M LiPF6 is within ±10% based on the electrolyte solution mixed at EC:EMC = 3:7, the viscosity and ionic conductivity are judged to be acceptable (viscosity of 3.78 cPs@25℃, ionic conductivity of 8.65 mS / cm). The results are shown in Table 2 below.

[0145] [Table 2]

[0146]

[0147] [Experimental Example 3 (Measurement of electrode misalignment)]

[0148] For the unit cells manufactured in Examples 1 to 7 and Comparative Examples 1 to 5, electrode misalignment was measured at 170 kV, 200 umA, and 34 W using a computed tomography (CT) scanner of GE company at a resolution of 33 um / pixel. The results are shown in Table 3 below.

[0149] [Table 3]

[0150]

[0151] [Analysis of experimental results]

[0152] Referring to Tables 1 to 3, when the composition consisting of acResin 250UV at a content of 0.75 wt.% is used for the first adhesive portion and the composition consisting of acResin 250UV, Loctite EA608, and Technomelt 4046 at a content of 0.25 wt.% is used for the second adhesive portion as in Examples 1 to 3, it can be confirmed that the dispersibility, viscosity, and ionic conductivity are all excellent and no electrode misalignment occurs.

[0153] Unlike this, when the composition consisting of Supra 502 at a content of 0.75 wt.% is used for the first adhesive portion and the composition consisting of Supra 502 at a content of 0.25 wt.% is used for the second adhesive portion, it can be confirmed that no electrode misalignment occurs, but the dispersibility is too low and the viscosity and ionic conductivity cannot be measured. In addition, the same explanation can even be applied to the case of 2802dispomelt, HPX 002, and EH9702, which have low dispersibility.

[0154] Therefore, when the dispersity of the first adhesive portion and the second adhesive portion is the same as or similar to each other, it can be confirmed that, unlike Comparative Example 4, as in Examples 1 to 3, it is appropriate that the first adhesive portion and the second adhesive portion respectively include at least one of acResin 250UV, Loctite EA608, and Technomelt 4046 having a relatively high dispersity.

[0155] Further, in the case of Comparative Example 2 in which the total content of the first adhesive portion and the second adhesive portion is small, unlike Example 1, it can be confirmed that electrode misalignment is generated. Further, in Comparative Example 3 in which the total content of the first adhesive portion and the second adhesive portion is large, unlike Example 1, it can be confirmed that the dispersity is too low, and thus the viscosity and the ion conductivity cannot be measured.

[0156] Therefore, it can be confirmed that the total content of the first adhesive portion and the second adhesive portion is appropriately included in the range of 0.8 wt.% or more to 1.2 wt.% or less, as in Example 1.

[0157] Further, unlike Example 1, when the total content of the first adhesive portion and the second adhesive portion is the same, but the content of the first adhesive portion is small and the content of the second adhesive portion is large, it can be confirmed that electrode misalignment is generated. Further, unlike Example 1, in the case of Comparative Example 2 in which the content of the first adhesive portion is small, it can be confirmed that electrode misalignment is generated. Further, unlike Example 1, in the case of Comparative Example 3 in which the content of the second adhesive portion is large, it can be confirmed that the dispersity is too low, and thus the viscosity and the ion conductivity cannot be measured.

[0158] Therefore, it can be confirmed that, appropriately, the content of the first adhesive portion is included in the range of 0.6 wt.% or more to 0.9 wt.% or less, and the content of the second adhesive portion is included in the range of 0.1 wt.% or more to 0.45 wt.% or less, as in Example 1.

[0159] Further, with reference to Tables 1 to 3, when components including acResin 250UV, Loctite EA608, and Technomelt 4046 each having a content of 0.75 wt.% are used for the first adhesive portion, and components consisting of Supra 502 having a content of 0.25 wt.% are used for the second adhesive portion (as in Examples 4 to 6), it can be confirmed that the dispersity, the viscosity, and the ion conductivity are all excellent, and electrode misalignment is not generated.

[0160] In contrast, as in Comparative Example 5, when the composition consisting of Supra 502 in an amount of 0.75 wt.% is used for the first binder portion and the composition consisting of acResin 250UV in an amount of 0.25 wt.% is used for the second binder portion, it can be confirmed that electrode deformation does not occur, but the dispersibility is too low, and thus the viscosity and the ion conductivity cannot be measured. In addition, the same explanation can be applied even to the case where 2802dispomelt, HPX 002, and EH9702, which have lower dispersibility than Supra 502, are used for the first binder portion.

[0161] Therefore, when the dispersibility of the first binder portion and the second binder portion is greatly different, it can be confirmed that, unlike Comparative Example 5, it is appropriate that the first binder portion includes at least one of acResin 250UV, Loctite EA608, and Technomelt 4046, which have relatively high dispersibility, and the second binder portion includes at least one of Supra 502, 2802dispomelt, HPX 002, and EH9702, which have relatively low dispersibility, as in Examples 4 to 6.

[0162] In addition, in the case of Comparative Example 3, which is different from Example 4 in which the content of the first binder portion is large, it can be confirmed that electrode misalignment does not occur, but the dispersibility is too low, and thus the viscosity and the ion conductivity cannot be measured. In addition, when the content of the second binder portion is increased, unlike Example 4, the dispersibility is too low, and thus the viscosity and the ion conductivity cannot be measured.

[0163] Therefore, it can be confirmed that it is appropriate that the content of the first binder portion is included in the range of 0.6 wt.% or more to 0.9 wt.% or less, and the content of the second binder portion is included in the range of 0.1 wt.% or more to 0.45 wt.% or less, as in Example 1.

[0164] In addition, with reference to Tables 1 to 3, when the composition consisting of acResin 250UV in an amount of 0.75 wt.% is used for the first binder portion, and the composition consisting of 2802dispomelt in an amount of 0.15 wt.% is used for the second binder portion, as in Example 7, it can be confirmed that the dispersibility, the viscosity, and the ion conductivity are all excellent, and electrode misalignment does not occur.

[0165] In contrast, if the dispersity of the second binder portion is too low, the viscosity and ion conductivity cannot be measured. Therefore, in the case of 2802dispomelt, HPX002, and EH9702, which include a binder component having a dispersity that is too low in the second binder portion, it was confirmed that it is appropriate for the content of the second binder portion to be included in the range of 0.1 wt.% or more to 0.2 wt.% or less, as in Example 7.

[0166] Figure 7 is a cross-sectional view illustrating an electrode assembly according to one embodiment of the present disclosure.

[0167] Referring to Figure 7 The electrode assembly 3 according to the present embodiment can include an electrode stack 40 manufactured by repeatedly forming a basic unit 30 a plurality of times. Here, the basic unit 30 can be a unit in which a separator 322 is folded to have a zigzag shape, covers an electrode 31, and the electrode 31 and the separator 322 are stacked. That is, in the basic unit 30, one side and the other side of the separator 322 are sequentially folded to cover the electrode 31, and the electrode 31 and the separator 322 can be sequentially stacked.

[0168] The fixing tape can be attached to the electrode assembly 3, but one end of the separator 322 can cover a portion of the outer surface of the electrode stack 40, rather than covering a portion of the outer surface of the fixing tape. The basic unit 30 of the present embodiment can be in a state in which the electrodes 3112 and 3122 and the separator 322 are adhered to each other with the binder 34. Accordingly, the alignment between the electrodes 3112 and 3122 and the separator 322 can be maintained by the adhesion of the binder 34.

[0169] In the electrode stack 40 of the present embodiment, the separator 322 covers the upper and lower portions and one side of the electrodes 3112 and 3122, and thus the stacking alignment of the basic unit 30 can be maintained without the fixing tape. Furthermore, when the fixing tape is attached to the outside of the electrode stack 40 of the present embodiment or the fixing tape is wound around one end of the separator 322, the stacking alignment of the basic unit 30 is more stably maintained.

[0170] In addition, in the electrode assembly 3 manufactured in the present embodiment, the binder 34 can be disposed at the same position between the electrodes 3112 and 3122 and the separator 322. For example, as Figure 7As shown in FIG. 1, in the electrode assembly 3 of the present embodiment, the adhesive 34 positioned between the lower portion of the first electrode 3112 and the separator 322 and the adhesive 34 positioned between the upper portion of the first electrode 3112 and the separator 322 can be arranged on the same vertical line with respect to the bottom surface of the first electrode 3112 or the separator 322, respectively, and the gaps for arranging the adhesives 34 can be equal to each other. This can similarly explain the case where the adhesive 34 is positioned between the second electrode 3122 and the separator 322.

[0171] Therefore, in the electrode assembly 3 manufactured in the present embodiment, the adhesives 34 are arranged at the same positions between the electrodes 3112 and 3122 and the separator 322, thereby existing an advantage in that the process time and efficiency can be improved.

[0172] Figure 8 is a cross-sectional view showing an electrode assembly according to another embodiment of the present disclosure.

[0173] Referring to Figure 8 In the electrode assembly 4 according to the present embodiment, the adhesives 34 are arranged between the electrodes 3112 and 3122 and the separator 322, and the adhesives 34 arranged in adjacent layers can be arranged in a staggered form. For example, as shown in FIG. 2, the adhesives 34 arranged in the electrode assembly 4 of the present embodiment can be arranged in a staggered form. Figure 8 As shown in FIG. 1, in the electrode assembly 3 of the present embodiment, the adhesive 34 positioned between the lower portion of the first electrode 3112 and the separator 322 and the adhesive 34 positioned between the upper portion of the first electrode 3112 and the separator 322 can be arranged on the same vertical line with respect to the bottom surface of the first electrode 3112 or the separator 322, respectively, and the gaps for arranging the adhesives 34 can be equal to each other. This can similarly explain the case where the adhesive 34 is positioned between the second electrode 3122 and the separator 322.

[0174] However, the present invention is not limited thereto, and the structure in which the first adhesive 34-1 and the second adhesive 34-2 are displaced from each other can be manufactured by applying various methods.

[0175] Therefore, in the electrode assembly 4 of the present embodiment, the adhesives 34 are arranged between the electrodes 3112 and 3122 and the separator 322, and the adhesives 34 arranged in adjacent layers are staggered. Therefore, it is possible to minimize the increase in the thickness of the electrode assembly 4 due to the adhesives 34. Further, since the adhesives 34 arranged in adjacent layers are displaced from each other, the adhesives 34 can be more easily dissolved in the electrolyte included in the above-described battery cell.

[0176] The first adhesive component included in the first adhesive portion 310 can be used as the adhesive 34 used in the electrode assemblies 3 and 4 according to Figure 7 and Figure 8 of the present disclosure.

[0177] While the application has been shown and described with reference to the preferred embodiments, it will be understood by those skilled in the art that various changes in form and detail can be made therein without departing from the spirit and scope of the application as defined by the appended claims.

[0178] [Legend of Reference Numerals]

[0179] 100: unit cell

[0180] 110: first electrode

[0181] 150: second electrode

[0182] 210: lower separator

[0183] 250: upper separator

[0184] 310: first adhesive portion

[0185] 350: second adhesive portion

[0186] 1000: battery cell

[0187] 1100: electrode assembly

[0188] 2000: battery case

[0189] 3000: electrode lead

[0190] 4000: lead film

Claims

1. A unit battery comprising: a separator and an electrode, which are alternately stacked in a predetermined number; a first adhesive portion positioned between the separator and the electrode and including a first adhesive component; and a second adhesive portion positioned between the separator and another separator to fix them to each other and including a second adhesive component, wherein the first adhesive component has a higher dispersibility in an electrolyte solution than the second adhesive component, and the first adhesive portion is dissolved in the electrolyte solution. 2.The unit battery of claim 1, wherein the first adhesive component includes at least one of an ethylene-vinyl acetate (EVA)-based material, an acrylic-based material, and an epoxy-based material, and the second adhesive component includes at least one of an EVA-based material, an acrylic-based material, an epoxy-based material, a polyolefin-based material, a rubber-based material, a polyamide-based material, and a polyurethane-based material. 3.The unit battery of claim 1, wherein the second adhesive component includes at least one of a polyolefin-based material, a rubber-based material, a polyamide-based material, and a polyurethane-based material. 4.The unit battery of claim 1, wherein the separator includes a lower separator and an upper separator, and the electrode includes a first electrode and a second electrode, wherein the lower separator, the first electrode, the upper separator, and the second electrode are stacked in this order. 5.The unit battery of claim 4, wherein the first adhesive portion is positioned at at least one location selected from between the first electrode and the lower separator, between the first electrode and the upper separator, and between the second electrode and the upper separator. 6.The unit battery of claim 5, wherein the second adhesive portion is positioned between the upper separator and the lower separator. 7.The unit battery of claim 1, wherein each of the first adhesive portion and the second adhesive portion is formed in a pattern including a plurality of dots. 8.The unit battery of claim 7, wherein the plurality of dots are spaced apart from each other. 9.An electrode assembly formed by alternately stacking the unit battery of any one of claims 1 to 8, the electrode assembly being configured such that: the first adhesive portion includes an adhesive pattern arranged at the same location between the electrode and the separator. 10.An electrode assembly formed by alternately stacking the unit battery of any one of claims 1 to 8, the electrode assembly being configured such that: the first adhesive portion includes an adhesive pattern arranged in a staggered form between the electrode and the separator. 11.A battery cell including an electrolyte solution and an electrode assembly in which the unit battery of claim 1 is alternately stacked. 12.The battery cell of claim 11, wherein ​ The first adhesive component includes at least one of an ethylene-vinyl acetate (EVA)-based material, an acrylic-based material, and an epoxy-based material, and The second adhesive component includes at least one of an ethylene-vinyl acetate (EVA)-based material, an acrylic-based material, an epoxy-based material, a polyolefin-based material, a rubber-based material, a polyamide-based material, and a polyurethane-based material.

13. The battery cell of claim 12, wherein The content of the first adhesive component and the second adhesive component is 0.8 wt.% or more to 1.2 wt.% or less with respect to the content of the electrolyte solution.

14. The battery cell of claim 13, wherein The content of the first adhesive component is 0.6 wt.% or more to 0.9 wt.% or less with respect to the content of the electrolyte solution, and The content of the second adhesive component is 0.1 wt.% or more to 0.45 wt.% or less with respect to the content of the electrolyte solution.

15. The battery cell of claim 12, wherein The second adhesive component includes at least one of a rubber-based material, a polyamide-based material, and a polyurethane-based material.

16. The battery cell of claim 15, wherein The content of the second adhesive component is 0.1 wt.% or more to 0.2 wt.% or less with respect to the content of the electrolyte solution.

17. The battery cell of claim 11, wherein The electrolyte solution includes at least one of an organic liquid electrolyte, an inorganic liquid electrolyte, a solid polymer electrolyte, a gel-type polymer electrolyte, a solid inorganic electrolyte, and an inorganic molten electrolyte.

18. The battery cell of claim 11, wherein The separator is folded to have a zigzag shape.

19. A method of manufacturing a unit cell, the method comprising the steps of: applying a first adhesive to a first face of an electrode or to an adjoining region of a first separator or to both; applying a second adhesive to a second face of the electrode or to an adjoining region of a second separator or to both, the second face of the electrode being on an opposite side of the first face of the electrode; applying a second adhesive to a peripheral region of the first separator or to a peripheral region of the second separator or to both, to secure the first separator and the second separator to each other; and forming at least a portion of an electrode assembly by stacking the electrode between the first separator and the second separator such that the first face of the electrode adjoins the adjoining region of the first separator and the second face of the electrode adjoins the adjoining region of the second separator, the electrode assembly being formed such that the peripheral region of each of the first separator and the second separator extends outward beyond an edge of the electrode, the peripheral region of each of the first separator and the second separator facing each other without the electrode interposed therebetween, wherein the first adhesive is configured to have a greater dispersibility in the electrolyte solution than the second adhesive has in the electrolyte solution, and the first adhesive is dissolved in the electrolyte solution.

20. The method of claim 19, wherein, The peripheral region of each of the first and second separators extends around a perimeter of the respective first and second separators, such that each of the peripheral regions encircles the abutment region of the respective first and second separators.

21. The method of claim 19, wherein, the first adhesive comprises at least one of an ethylene-vinyl acetate (EVA)-based material, an acrylic-based material, and an epoxy-based material, and the second adhesive comprises at least one of an ethylene-vinyl acetate (EVA)-based material, an acrylic-based material, an epoxy-based material, a polyolefin-based material, a rubber-based material, a polyamide-based material, and a polyurethane-based material.

22. The method of claim 19, wherein, the first and second adhesives are each applied in a respective dot pattern, the dots being spaced apart from one another.

23. The method of claim 22, wherein, The dots of the dot pattern of the first adhesive are arranged in a grid of rows and columns of dots.

24. A method of manufacturing a battery cell, the method comprising the steps of: forming an electrode assembly by alternately stacking unit cells formed according to the method of claim 19; and placing the electrode assembly and an electrolyte in a battery case.

25. The method of claim 24, wherein, The electrolyte is a solution comprising at least one of an organic liquid electrolyte, an inorganic liquid electrolyte, a solid polymer electrolyte, a gel-type polymer electrolyte, a solid inorganic electrolyte, and an inorganic molten electrolyte.

26. The method of claim 24, wherein, The total amount of the first adhesive in the battery case is 0.6 wt.% to 0.9 wt.% of the total amount of the electrolyte in the battery case.

27. The method of claim 24, wherein, The total amount of the second adhesive in the battery case is 0.1 wt.% to 0.45 wt.% of the total amount of the electrolyte in the battery case.

28. The method of claim 24, wherein, The total amount of the first and second adhesives in the battery case is 0.8 wt.% to 1.2 wt.% of the total amount of the electrolyte in the battery case.

29. The method of claim 28, wherein, The total amount of the first adhesive in the battery case is 0.6 wt.% to 0.9 wt.% of the total amount of the electrolyte in the battery case, and wherein the total amount of the second adhesive in the battery case is 0.1 wt.% to 0.45 wt.% of the total amount of the electrolyte in the battery case.

30. The method of claim 24, wherein, The second adhesive comprises at least one of a polyolefin-based material, a rubber-based material, a polyamide-based material, and a polyurethane-based material.

31. The method of claim 30, wherein, The total amount of the second adhesive in the battery case is 0.1 wt.% to 0.2 wt.% of the total amount of the electrolyte in the battery case.

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