Electrode assembly and electrochemical device including same

Abstract

The present invention relates to an electrode assembly having a novel structure, and an electrochemical device comprising same, the electrode assembly comprising: a first unit comprising at least one first monocell; a second unit comprising at least one second monocell; and an insulating film interposed between the first unit and the second unit, wherein the first unit and the second unit are electrically connected in series so as to implement a high nominal voltage and a high energy density. According to one aspect of the present invention, an advantageous effect may be achieved in that a nominal voltage of the electrochemical device can be improved while minimizing a configuration of auxiliary components of the electrochemical device.

Description

Electrode assembly and electrochemical device including the same

[0001] The present invention relates to an electrode assembly for an electrochemical device and an electrochemical device including the same.

[0002] This application claims priority based on Korean Patent Application No. 2024-0133079 filed with the Korean Intellectual Property Office on September 30, 2024, and all contents disclosed in the specification of said application are incorporated into this application.

[0003] Recently, due to air pollution caused by the use of fossil fuels and the development of alternative energy sources resulting from energy depletion, the demand for electrochemical devices capable of storing generated electrical energy is increasing. Rechargeable electrochemical devices are being closely utilized in daily life, such as in mobile devices, electric vehicles, and hybrid electric vehicles.

[0004] Electrochemical devices, which are used as energy sources for various electronic devices that are indispensable in modern society, are required to increase in capacity due to the increased usage and complexity of mobile devices and the development of electric vehicles. To meet user demand, multiple battery cells are arranged in small devices, whereas in automobiles, battery modules that electrically connect multiple battery cells or battery packs equipped with multiple such battery modules are used.

[0005] Meanwhile, pouch-type electrochemical devices are sealed after housing an electrode assembly inside a case, and the electrode assembly is structured such as a jelly-roll type electrode assembly in which a separator is interposed between a long sheet-type cathode and anode and then wound; a stack-type electrode assembly composed of unit cells in which rectangular anodes and cathodes are stacked with a separator interposed between them; a stack-folding type electrode assembly in which unit cells are wound by a long separating film; or a lamination-stack type electrode assembly in which unit cells are stacked with a separator interposed between them and attached to one another.

[0006] A generally known electrode assembly has a structure in which multiple monocells are stacked in the order of separator, cathode, separator, and anode from bottom to top, and a half-cell with a cathode interposed between a pair of separators is located at the very top. Additionally, all cathodes and anodes are connected in parallel to form the cathode and anode terminals.

[0007] According to the conventional general electrode assembly described above, there is an advantage in that the battery capacity can be increased by increasing the number of monocells stacked in a single battery cell, but there is a disadvantage in that the nominal voltage cannot be increased because the negative and positive electrodes are all connected in parallel.

[0008] Therefore, the problem that the present invention aims to solve is,

[0009] The purpose is to provide an electrochemical device having high energy density and high voltage performance.

[0010] Specifically, according to one aspect of the present invention, the invention aims to provide an electrode assembly and an electrochemical device including the same that can realize a battery having a high voltage while minimizing the composition of auxiliary materials to realize the high energy density, which is an advantage of lithium electrochemical devices.

[0011] More specifically, according to one aspect of the present invention, the invention aims to provide an electrochemical device having high voltage performance with a single package and by minimizing the composition of auxiliary materials.

[0012] In order to solve the above problem,

[0013] According to one aspect of the present invention, electrode assemblies of the following embodiments are provided.

[0014] The electrode assembly according to the first embodiment is,

[0015] A first unit comprising at least one first monocell,

[0016] A second unit comprising at least one second monocell, and

[0017] It includes an insulating film interposed between the first unit and the second unit, and

[0018] The first unit and the second unit are electrically connected in series.

[0019] According to the second embodiment, in the first embodiment,

[0020] The first unit comprises two or more first monocells electrically connected in parallel, and

[0021] The second unit may include two or more second monocells electrically connected in parallel.

[0022] According to the third embodiment, in the first embodiment or the second embodiment,

[0023] Each of the electrode tabs in the first unit and the second unit may be located on the same short side line of the electrode assembly.

[0024] According to the fourth embodiment, in any one of the first to third embodiments,

[0025] The first electrode tab in the first unit and the second electrode tab in the second unit may be positioned such that at least a portion overlaps with respect to the stacking direction of the first unit and the second unit.

[0026] The first electrode and the second electrode may be electrodes with different polarities.

[0027] According to the fifth embodiment, in any one of the first to fourth embodiments,

[0028] It may include a welded portion in which a first electrode tab in the first unit and a second electrode tab in the second unit are welded.

[0029] The first electrode and the second electrode are electrodes with different polarities.

[0030] According to the 6th embodiment, in any one of the 1st to 5th embodiments,

[0031] The first monocell above includes a first cathode, a first separator, and a first anode that are sequentially stacked, and

[0032] The second monocell above includes a second anode, a second separator, and a second cathode that are sequentially stacked, and

[0033] The above welded part is,

[0034] The first positive tab and the second negative tab are welded, or

[0035] The first cathode tab and the second anode tab may be formed by welding.

[0036] According to the seventh embodiment, in any one of the first to sixth embodiments,

[0037] It may further include a sealing portion for sealing the above-mentioned welded portion.

[0038] According to the eighth embodiment, in any one of the first to seventh embodiments,

[0039] The first monocell and the second monocell may be included in the same number.

[0040] According to the ninth embodiment, in any one of the first to eighth embodiments,

[0041] The insulating film may have a shape in which an opening is formed so that the first electrode tab in the first unit and the second electrode tab in the second unit come into contact.

[0042]

[0043] According to another aspect of the present invention, electrochemical elements of the following embodiments are provided.

[0044] The electrochemical device according to the 10th embodiment is,

[0045] An electrode assembly according to any one of the first to ninth embodiments,

[0046] Electrolytes, and

[0047] It may include a case for storing these.

[0048] According to the 11th embodiment, in the 10th embodiment,

[0049] It may include electrode leads connected to each electrode tab positioned so as not to overlap based on the stacking direction of the first unit and the second unit.

[0050] According to the 12th embodiment, in the 10th embodiment or the 11th embodiment,

[0051] It may include a welded portion in which a first electrode tab in the first unit and a second electrode tab in the second unit are welded.

[0052] The case may further include an insulating member provided at a location where the welded part contacts the inner side of the case.

[0053] According to the 13th embodiment, in any one of the 10th to 12th embodiments,

[0054] The above case may further include a sealing portion that seals the outer periphery.

[0055] According to the 14th embodiment, in any one of the 10th to 13th embodiments,

[0056] The above case may be a pouch-type case.

[0057] An electrode assembly according to one embodiment of the present invention has the effect of enabling the realization of an electrochemical device having high voltage performance with only a single package.

[0058] Specifically, by using n monocells relative to the nominal voltage (Vn) of a single monocell, it is possible to provide an electrochemical device that exhibits a nominal voltage of nx Vn.

[0059] FIG. 1 is a side view of a first monocell (100) according to one embodiment of the present invention.

[0060] FIG. 2 is a side view of a first monocell (100) according to one embodiment of the present invention.

[0061] FIG. 3 is a side view of a second monocell (200) according to one embodiment of the present invention.

[0062] FIG. 4 is a side view of a second monocell (200) according to one embodiment of the present invention.

[0063] FIG. 5 is an exploded perspective view of a first monocell (100) and an exploded perspective view of a first unit in which two or more first monocells (100) are stacked according to one embodiment of the present invention.

[0064] FIG. 6 is an exploded perspective view of a second monocell (200) and an exploded perspective view of a second unit in which two or more second monocells (200) are stacked according to one embodiment of the present invention.

[0065] FIG. 7 is an exploded perspective view of an electrode assembly (1) according to one embodiment of the present invention.

[0066] FIG. 8 is a schematic diagram showing the location where the electrode lead (400) is formed in the electrode assembly (1) of FIG. 7.

[0067] FIG. 9 is a drawing for explaining the assembly form of an electrode assembly (1) according to one embodiment of the present invention.

[0068] FIG. 10 is a drawing for explaining the assembly process in which an electrode assembly (1) according to one embodiment of the present invention is housed in a pouch-type case (500).

[0069] FIG. 11 is a drawing for explaining an electrochemical device assembled according to one embodiment of the present invention.

[0070] The present invention will be described in detail below.

[0071] In this specification, when a part is described as "comprising" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0072] In this specification, the description of the term "A and / or B" means "A or B, or both."

[0073] In this specification, words indicating directions such as up, down, left, right, outside, and inside are for convenience only and are not intended to limit the invention.

[0074] The present invention relates to an electrode assembly and an electrochemical device comprising the same.

[0075] In the present invention, the electrochemical device is a device that converts chemical energy into electrical energy through an electrochemical reaction, and is a concept that includes a primary battery and a secondary battery. The secondary battery is capable of charging and discharging and is a concept that encompasses lithium-ion batteries, nickel-cadmium batteries, nickel-hydrogen batteries, etc.

[0076]

[0077] [Electrode Assembly]

[0078] An electrode assembly according to one aspect of the present invention comprises two or more monocells connected in series with each other.

[0079] Specifically, the electrode assembly (1) comprises a first unit including at least one first monocell (100), a second unit including at least one second monocell (200), and an insulating film (300) interposed between the first unit and the second unit.

[0080] According to one aspect of the present invention, the term "mono cell" refers to a unit cell in which electrodes having different polarities are stacked with a separator in between. For example, it may refer to a laminate in which a negative electrode, a separator, and a positive electrode are sequentially stacked in the thickness direction. Additionally, the mono cell may further include a separator at the top and / or bottom of the laminate.

[0081] In contrast, in this specification, 'half cell' refers to a laminate in which only an electrode having one polarity is interposed between separators. For example, it may refer to a laminate having a structure of separator / cathode / separator or separator / anode / separator.

[0082] In one embodiment of the present invention, the term "unit" refers to a structure comprising one or more monocells. The unit may comprise one monocell or be a structure in which two or more monocells are stacked in the thickness direction. Additionally, the unit may be a structure comprising one monocell and one halfcell. Alternatively, the unit may be a structure in which two or more monocells are stacked in the thickness direction and one halfcell is additionally included at the top and / or bottom. In other words, the "unit" may be referred to as a stacked cell. For example, the first unit may be referred to as a first stacked cell and the second unit as a second stacked cell.

[0083] Accordingly, an electrode assembly according to one aspect of the present invention may have a structure comprising two stack cells electrically connected in series, with an insulating film interposed between the two stack cells.

[0084] In this specification, the first monocell and the second monocell are merely terms used to describe monocells provided on the left-right or top-bottom sides, respectively, centered on an insulating film; the specific structure and / or composition of the first monocell and the second monocell may be identical or different from each other, and the present invention is not limited thereto. In this specification, for convenience of description, the electrode, anode, cathode, and separator included in the first monocell may be referred to as the first electrode, the first anode, the first cathode, and the first separator, and the electrode, anode, cathode, and separator included in the second monocell may be referred to as the second electrode, the second anode, the second cathode, and the second separator.

[0085] In this specification, when the term "electrode" is used without distinguishing between an anode and a cathode, the electrode may be either an anode or a cathode. Furthermore, since the specific configurations of the anode and cathode may utilize conventional forms, a description thereof will be omitted.

[0086] FIGS. 1 and FIGS. 2 each show a side view of a first monocell (100) according to one embodiment of the present invention. Referring to FIGS. 1, the first monocell (100) includes a first cathode (110), a first separator (130), and a first anode (120) stacked sequentially in the thickness direction. Referring to FIGS. 2, the first monocell (100) may include a first separator (130), a first cathode (110), a first separator (130), and a first anode (120) stacked sequentially in the thickness direction.

[0087] FIGS. 3 and FIGS. 4 each show a side view of a second monocell (200) according to one embodiment of the present invention. Referring to FIG. 3, the second monocell (200) includes a second anode (220), a second separator (230), and a second cathode (210) that are sequentially stacked in the thickness direction. Referring to FIG. 4, the second monocell (200) may include a second separator (230), a second anode (220), a second separator (230), and a second cathode (210) that are sequentially stacked in the thickness direction.

[0088] In this specification, the term "thickness direction" refers to the direction in which the cathode, separator, and anode are stacked within the electrode assembly. Additionally, the "thickness direction" may coincide with the direction in which the first monocell is stacked within the first unit, the direction in which the second monocell is stacked within the second unit, or the direction in which the first unit, insulating film, and second unit are stacked within the electrode assembly.

[0089] FIG. 5 illustrates a schematic diagram in which p first monocells (100) are stacked (1 ≤ an integer p) to form a first unit according to one embodiment of the present invention. Referring to FIG. 5, the direction in which p first monocells are stacked within the first unit can be referred to as the thickness direction of the electrode assembly.

[0090] FIG. 6 illustrates a schematic diagram in which q (an integer of 1 ≤ q) second monocells (200) are stacked to form a second unit according to one embodiment of the present invention. Referring to FIG. 6, the direction in which q second monocells are stacked within the second unit can be referred to as the thickness direction of the electrode assembly.

[0091] In one embodiment of the present invention, p and q may each be an integer of 1 or more independently of each other, and it is preferable to vary the number of stacked monocells depending on the specifications of the electrochemical device in which the electrode assembly is used. For example, depending on the specifications of the electrochemical device, p and q may each be 1 to 200, 5 to 150, 10 to 100, 15 to 90, 20 to 80, 25 to 70, 30 to 60, or 40 to 50 independently of each other, and are not particularly limited to the number.

[0092] In one embodiment of the present invention, the electrode assembly may preferably include the first monocell and the second monocell in equal numbers, but the present invention is not limited thereto.

[0093] In one embodiment of the present invention, the first unit may include one first monocell or two or more first monocells. Here, if the first unit includes two or more first monocells, the two or more first monocells are electrically connected in parallel.

[0094] Likewise, in one embodiment of the present invention, the second unit may include one second monocell or two or more second monocells. Here, if the second unit includes two or more second monocells, the two or more second monocells are electrically connected in parallel.

[0095] To this end, when two or more first monocells are included within the first unit, it may be preferable that the included first positive tabs be included at positions that overlap with respect to the stacking direction of the first monocells. Furthermore, the included first positive tabs may be connected to each other to form a bundle of first positive tabs. Similarly, when two or more first monocells are included within the first unit, the included first negative tabs may be included at positions that overlap with respect to the stacking direction of the first monocells and may be connected to each other to form a bundle of first negative tabs.

[0096] In one embodiment of the present invention, in order to prevent a short circuit caused by physical contact between the anode and the cathode within the first unit, it may be preferable that the first anode tab bundle and the first cathode tab bundle be provided at positions that do not overlap with respect to the stacking direction of the first monocell.

[0097] More specifically, the first positive tab bundle and the first negative tab bundle may be preferably located on the same short side line of the first unit, but at a position that does not overlap with respect to the stacking direction of the first monocell.

[0098] In another embodiment of the present invention, when the second unit, like the first unit, also includes two or more second monocells, a second positive tab bundle and a second negative tab bundle may be formed, and it may be preferable that the second positive tab bundle and the second negative tab bundle are provided at positions that do not overlap with each other with respect to the stacking direction of the second monocells.

[0099] In one embodiment of the present invention, it may be preferable that each of the electrode tabs in the first unit and the second unit, or each of the electrode tab bundles in the first unit and the second unit, be located on the same short side line of the electrode assembly.

[0100] As described above, each of the first unit and the second unit may include a plurality of first monocells or a plurality of second monocells. For convenience of description, the configuration of an electrode assembly having one first monocell, an insulating film, and one second monocell may be described below; however, the electrode assembly may include a first unit in which two or more first monocells are stacked instead of one first monocell, and a second unit in which two or more second monocells are stacked instead of one second monocell, and the structure of the present invention is not limited thereto.

[0101] An electrode assembly according to one aspect of the present invention comprises a first unit including at least one first monocell and a second unit including at least one second monocell, wherein the first unit and the second unit are electrically connected in series to increase the nominal voltage of the electrode assembly by the number of stacks of the first and second monocells.

[0102] At this time, the electrode assembly includes a first unit and a second unit electrically connected in series, and includes an insulating film to block electricity and prevent the electrolyte from communicating except at a location connected in series between the first unit and the second unit.

[0103] In one embodiment of the present invention, the insulating film may be used without limitation as long as it is made of a material having insulating performance to electrically isolate the first unit and the second unit, except for a serial connection position. For example, the insulating film may be a material comprising polyethylene terephthalate (PET), polyimide (PI), polypropylene (PP), polyethylene (PE), polyvinyl chloride (PVC), high-density polyethylene (HDPE), epoxy resin, or a mixture of two or more of these, but the present invention is not limited thereto.

[0104] FIG. 7 shows an exploded perspective view of an electrode assembly (1) according to one embodiment of the present invention. Referring to FIG. 7, the electrode assembly (1) includes a first unit including a first monocell (100) on one side and a second unit including a second monocell (200) on the other side, with an insulating film (300) in between. At this time, for electrical series connection of the first unit and the second unit, the first electrode (120) and the second electrode (210), which have opposite polarities, may have a structure in which they physically come into contact through electrode tabs (121, 211).

[0105] In one embodiment of the present invention, it may be preferable for the insulating film (300) to have a shape having an opening so that the first electrode tab and the second electrode tab can physically come into contact. For example, referring to FIG. 7, the first positive electrode tab (121) and the second negative electrode tab (211) are connected in series, and the insulating film (300) may have a shape in which an opening is formed at a position where the first positive electrode tab (121) and the second negative electrode tab (211) come into contact so that they can come into contact.

[0106] According to another embodiment of the present invention, a first negative tab (111) in a first monocell and a second positive tab (221) in a second monocell may be connected in series within the electrode assembly (1) according to the stacking order, but the present invention is not limited thereto.

[0107] As described above, according to one embodiment of the present invention, the structure in which the first positive tab (121) and the second negative tab (211) come into contact within the electrode assembly may represent a structure in which the first positive tab bundle and the second negative tab bundle or the first negative tab bundle and the second positive tab bundle come into contact when the first monocell and the second monocell are each included in a plurality.

[0108] In one embodiment of the present invention, for electrical series connection of the first unit and the second unit, the first electrode tab (or first electrode tab bundle) in the first unit and the second electrode (or second electrode tab bundle) in the second unit may be positioned such that at least a portion overlaps with respect to the stacking direction. At this time, the first electrode and the second electrode must have different polarities. For example, referring to FIG. 7, the electrode assembly (1) may be provided with the first positive electrode tab (121) and the second negative electrode tab (211) in a position where they overlap with respect to the stacking direction of the electrode assembly.

[0109] According to one embodiment of the present invention, when the first positive electrode tab (121) and the second negative electrode tab (211) are configured to come into contact, it is preferable that the first negative electrode tab (111) and the second positive electrode tab (221) be provided at positions that do not overlap with respect to the stacking direction. More preferably, when manufacturing an electrochemical device, it is preferable that the electrode leads be formed to be connected to the electrode tabs provided at positions that do not overlap each other.

[0110] For example, FIG. 8 illustrates a configuration in which an electrode lead (400) is connected to an electrode tab when manufacturing an electrochemical device using the electrode assembly (1). Referring to FIG. 8, the first negative tab (111) and the second positive tab (221) are provided at positions that do not overlap with respect to the stacking direction, and a negative lead (410) may be connected to the first negative tab and a positive lead (420) may be connected to the second positive tab.

[0111] In one embodiment of the present invention, the first electrode tab and the second electrode tab, which are positioned such that at least a portion overlaps with respect to the stacking direction of the electrode assembly (1), may include a welded portion (600) formed by welding.

[0112] In one embodiment of the present invention, the electrode assembly (1) may further include a sealing portion for sealing the weld portion (600) to prevent the weld portion from detaching. The sealing portion may be made of a material selected from polyolefin resins such as polypropylene, polyethylene, polyethylene acrylic acid, and polybutylene, polyurethane resin, polyimide resin, or a mixture thereof, which have excellent chemical resistance and good sealing properties, and any material used as a sealing member of a battery may be used without limitation, even if not described.

[0113] FIG. 9 illustrates an assembly diagram of an electrode assembly (1) according to one embodiment of the present invention. Referring to FIG. 9, electrode tab portions that are in contact with each other are welded and then sealed, and electrode leads (410, 420) may be provided on each electrode tab provided at a position that does not overlap with each other. However, the position of the electrode tab where the electrode lead is provided and the position of the electrode tab that is in contact and welded in the electrode assembly may be modified and are not limited to the drawings exemplified in this specification. For example, according to FIG. 9, the position where the weld portion is formed is the center of one end side of the electrode assembly and the electrode lead is provided on the outer side of one end side, but as another example, the position where the weld portion is formed may be on one outer side of one end side of the electrode assembly and the electrode lead may be provided at the center and the other outer side of one end side, and the present invention is not limited thereto.

[0114]

[0115] [Electrochemical Device]

[0116] According to another aspect of the present invention, an electrochemical device comprising the electrode assembly described above is provided.

[0117] Specifically, the electrochemical device may include the electrode assembly described above, an electrolyte, and a case housing the same.

[0118] FIG. 10 illustrates an exploded schematic diagram of the electrode assembly (1) and case described above for manufacturing an electrochemical device according to one embodiment of the present invention. Referring to FIG. 10, the case may include an upper case and a lower case, and may have a pocket-shaped storage space formed to accommodate the electrode assembly.

[0119] In one embodiment of the present invention, the electrochemical element includes electrode leads (400) connected to each electrode tab positioned so as not to overlap with respect to the stacking direction of the first unit and the second unit, and each electrode lead (410, 420) may be provided to be exposed to the outside of the case.

[0120] In one embodiment of the present invention, the case may further include an auxiliary material composition, such as an insulating resin layer, inside the storage space to protect the electrode assembly.

[0121] However, according to one embodiment of the present invention, in order to reduce the weight of the electrochemical element by minimizing the composition of auxiliary materials, it may be more preferable to provide an insulating part (700) on the inner side of the case at a position where the welded part (600) between the electrode tabs in contact within the electrode assembly comes into contact.

[0122] Referring to FIG. 10, the insulating part (700) may preferably be provided in both the upper case and the lower case to improve the safety of the electrochemical element.

[0123] In one embodiment of the present invention, the electrochemical element may further include a sealing portion (800) to seal at least a portion of the outer periphery of the case.

[0124] Referring to FIG. 11, in one embodiment of the present invention, the sealing portion (800) may be provided to seal the outer periphery of the case.

[0125] In one embodiment of the present invention, the sealing portion that seals the outer periphery of the case may also be made of a material selected from polyolefin resins such as polypropylene, polyethylene, polyethylene acrylic acid, and polybutylene, polyurethane resin, polyimide resin, or a mixture thereof, which have excellent chemical resistance and good sealing properties, as described in the sealing portion of the welded portion. However, any material used as a sealing member for the case of an electrochemical element, even if not described, may be used without limitation.

[0126]

[0127] According to another aspect of the present invention, a method for manufacturing the electrode assembly described above and a method for manufacturing an electrochemical element are provided.

[0128] A method for manufacturing an electrode assembly according to one aspect of the present invention may include the steps of preparing each of a first unit and a second unit, interposing an insulating film between the first unit and the second unit, and electrically connecting the first unit and the second unit in series.

[0129] In one embodiment of the present invention, the step of preparing each of the first unit and the second unit may include the step of preparing a first monocell and a second monocell, respectively. Furthermore, if two or more monocells are included within the first unit and the second unit, the step of stacking each of the prepared first monocell and second monocell may be further included.

[0130] In one embodiment of the present invention, the step of preparing each of the first monocell and the second monocell may further include the step of laminating the anode, the separator, and the cathode in order, and, if necessary, including the separator at the top and / or bottom of the stack, and then applying a predetermined heat and / or pressure.

[0131] In one embodiment of the present invention, the step of electrically connecting the first unit and the second unit in series may include welding a first positive tab (or first positive tab bundle) in the first unit and a second negative tab (or second negative tab bundle) in the second unit, or welding a first negative tab (or first negative tab bundle) in the first unit and a second positive tab (or second positive tab bundle) in the second unit.

[0132] After that, if necessary, a sealing step for sealing the welded portion of the electrode tab may be further included.

[0133] A method for manufacturing an electrochemical device according to one aspect of the present invention may include the step of, after manufacturing an electrode assembly as described above, forming electrode leads on each of the unwelded electrode tabs (or tab bundles) in addition to the welded electrode tabs for serial connection of a first unit and a second unit within the electrode assembly.

[0134] Next, the method may include the step of housing the electrode assembly with the electrode leads formed thereon in a case and injecting an electrolyte.

[0135] According to one embodiment of the present invention, a sealing step of sealing the outer periphery of a case while the electrolyte is injected may be included.

[0136] However, the manufacturing method of the electrode assembly and electrochemical device described above is not limited thereto.

[0137]

[0138] The present invention will be described in more detail below through examples, but the following examples are intended to illustrate the invention and the scope of the invention is not limited thereto.

[0139] [Fabrication of Pouch-Type Electrochemical Devices]

[0140] Comparative Example 1

[0141] An electrode assembly stacked in the order of cathode, separator, and anode was placed in a pouch-type case, electrode leads were connected to the cathode tab and anode tab, respectively, and then the electrolyte was injected and the outer periphery of the case was sealed. At this time, the electrodes were prepared such that the cathode tab was formed on one outer side of the electrode and the anode tab was formed on the other outer side.

[0142]

[0143] Example 1

[0144] As shown in FIG. 8, two monocells were prepared in which a cathode, a separator, and an anode were stacked, and an insulating film (PET film) was interposed between the two monocells. At this time, the same electrodes and separators as those used in Comparative Example 1 were used, except that the anode tab in the upper monocell was positioned in the center of the electrode and the cathode tab in the lower monocell was positioned in the center of the electrode.

[0145] Referring to FIG. 9, the positive electrode tab (121) and the negative electrode tab (211), located in the center of the electrode assembly, were welded together and then sealed. Next, referring to FIG. 10, an insulating tape (700) was attached to the inner side of the case at the location where the welded part touches.

[0146]

[0147] Example 2

[0148] An electrochemical device was manufactured in the same manner as in Example 1, except that two monocells were stacked on the upper and lower sides, respectively.

[0149]

[0150] The nominal voltage (V), capacity (Ah), and energy (Wh) of the electrochemical devices of Comparative Example 1, Example 1, and Example 2 prepared above are compared and summarized as follows.

[0151] Nominal Voltage (V) Capacity (Ah) Energy (Wh) Comparative Example 1 XY xy Example 1 2 x 1 / 2 y Xy Example 2 2 x 2 y 4 xy

[0152] As can be seen in Table 1 above, it was confirmed that the nominal voltage of the electrochemical device can be increased by a multiple of the number of monocells by increasing the number of monocells included in the upper and lower sections, respectively, with the insulating film in between. At this time, it was confirmed that the energy density can be further increased as the capacitance of the electrochemical device also increases.

[0153] Although the present invention has been described with reference to embodiments thereof, those skilled in the art will be able to make various applications and modifications within the scope of the present invention based on the above description.

[0154]

[0155] [Explanation of the symbol]

[0156] 1: Electrode assembly

[0157] 100: The first monocell

[0158] 110: First cathode

[0159] 111: First cathode tab

[0160] 120: First anode

[0161] 121: 1st positive tap

[0162] 130: First separator

[0163] 1000: 1st Unit

[0164] 200: The 2nd Monocell

[0165] 210: Second cathode

[0166] 211: Second cathode tab

[0167] 220: Second bipolar anode

[0168] 221: Second positive tap

[0169] 230: Second separator

[0170] 2000: 2nd Unit

[0171] 300: Insulating film

[0172] 400: Electrode Lead

[0173] 410: Cathode Lead

[0174] 420: Positive lead

[0175] 500: Case

[0176] 600: Welded part

[0177] 700: Insulation part

[0178] 800: Sealing part

Claims

1. A first unit comprising at least one first monocell, A second unit comprising at least one second monocell, and It includes an insulating film interposed between the first unit and the second unit, and An electrode assembly in which the first unit and the second unit are electrically connected in series.

2. In Claim 1, The first unit comprises two or more first monocells electrically connected in parallel, and The above second unit is an electrode assembly comprising two or more second monocells electrically connected in parallel.

3. In Claim 1, An electrode assembly in which each of the electrode tabs within the first unit and the second unit is located on the same short side line of the electrode assembly.

4. In Claim 1, The first electrode tab in the first unit and the second electrode tab in the second unit are positioned such that at least a portion overlaps with respect to the stacking direction of the first unit and the second unit, and An electrode assembly in which the first electrode and the second electrode have different polarities.

5. In Claim 1, It includes a welded portion in which a first electrode tab in the first unit and a second electrode tab in the second unit are welded, An electrode assembly in which the first electrode and the second electrode are electrodes having different polarities.

6. In Claim 5, The first monocell above includes a first cathode, a first separator, and a first anode that are sequentially stacked, and The second monocell above includes a second anode, a second separator, and a second cathode that are sequentially stacked, and The above welded part is, The first positive tab and the second negative tab are welded, or An electrode assembly formed by welding the first cathode tab and the second anode tab.

7. In Claim 5, An electrode assembly further comprising a sealing portion for sealing the above-mentioned welded portion.

8. In Claim 1, An electrode assembly comprising the first monocell and the second monocell in equal numbers.

9. In Claim 1, The above insulating film is an electrode assembly having a shape in which an opening is formed so that a first electrode tab in the first unit and a second electrode tab in the second unit come into contact.

10. An electrode assembly according to any one of claims 1 to 9, Electrolytes, and Electrochemical device including a case for housing these.

11. In Claim 10, An electrochemical device comprising electrode leads connected to each electrode tab positioned so as not to overlap with respect to the stacking direction of the first unit and the second unit.

12. In Claim 10, It includes a welded portion in which a first electrode tab in the first unit and a second electrode tab in the second unit are welded, An electrochemical element further comprising an insulating portion provided on the inner side of the above case at a position where the welded portion contacts.

13. In claim 10, An electrochemical device further comprising a sealing portion that seals the outer periphery of the above case.

14. In Claim 10, The above case is an electrochemical device that is a pouch-type case.

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