Bipolar electrode, electrode assembly comprising same, bipolar battery comprising electrode assembly, and method for manufacturing bipolar battery

Abstract

The present invention relates to a bipolar electrode comprising: a current collector including a polymer film and a conductive layer added to at least a portion of the outer surface and inner surface of the polymer film; a positive electrode formed on a first surface of the current collector; and a negative electrode formed on a second surface of the current collector, wherein, by heat-fusing the current collector composed of the polymer film to implement a sealed form, the movement of electrolyte between the electrodes may be prevented.

Description

Bipolar electrode, electrode assembly including the same, bipolar battery including the electrode assembly, and method for manufacturing the bipolar battery

[0001] This application claims the benefit of priority to Korean Patent Application No. 10-2024-0027781, filed February 27, 2024, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a bipolar electrode, an electrode assembly including the same, a bipolar battery including the electrode assembly, and a method for manufacturing the bipolar battery. Specifically, the present invention relates to a bipolar electrode having a simplified means for preventing movement of electrolyte between stacked bipolar electrodes by changing the current collector structure of the bipolar electrode, an electrode assembly including the same, a bipolar battery including the electrode assembly, and a method for manufacturing the bipolar battery.

[0003]

[0004] Due to global climate change, the clock is ticking toward carbon neutrality, and the movement to replace fossil fuels with eco-friendly energy sources is growing. As one such eco-friendly energy source, lithium secondary batteries are replacing fossil fuels.

[0005] Lithium secondary batteries can be used as an energy source for devices that require a lot of energy, such as electric vehicles, due to their advantages of high energy density and high output, and the rate at which lithium secondary batteries are applied in various fields is increasing.

[0006] Lithium secondary batteries include a general type of monopolar electrode in which an electrode compound of the same polarity is applied to both sides of a current collector, or a bipolar electrode in which active materials having different polarities are applied to both sides of a current collector.

[0007] Bipolar electrodes have the advantage of forming a high potential and achieving high energy density and high output due to their structural characteristics in which the positive and negative electrodes are stacked to form a series connection.

[0008] In electrode assemblies comprising stacked bipolar electrodes, self-discharge and bypass current can occur if the electrolyte between different bipolar electrodes moves and mixes. Therefore, a structure is needed to separate the electrolyte by preventing it from moving between the bipolar electrodes.

[0009] In addition, when multiple bipolar electrodes are stacked, the current collectors of the bipolar electrodes may come into contact with each other, or if an uneven portion of the end of the bipolar electrode occurs, the electrode active material layer and the current collector may come into contact at that portion. This may cause an unexpected short circuit.

[0010] Accordingly, in the past, a structure was proposed in which an adhesive was added between the current collectors to fix the current collectors of the bipolar electrodes, or a separate member was placed on the outer periphery of the current collector and an adhesive was added to fix the separate member.

[0011] Patent Document 1 discloses a bipolar current collector including a base film and a first conductive layer and a second conductive layer coated on both sides of the base film, wherein a cathode material and a negative electrode material are attached on the first conductive layer and the second conductive layer, and a conductive sealing film including a sealing conductive layer and a polymer layer is installed on both ends of the base film. Each of the two ends of the sealing conductive layer of the conductive sealing film is connected to the first conductive layer and the second conductive layer, and the polymer layer is added so as to surround the sealing conductive layer from the outside and is connected to the first conductive layer and the second conductive layer.

[0012] Patent Document 1 discloses a structure comprising a current collector having a first conductive layer and a second conductive layer coated on both sides of a base film, and a conductive sealing film connected to the current collector while ensuring insulation from adjacent bipolar electrodes and preventing movement of electrolyte. However, Patent Document 1 requires that, in addition to the current collector, a conductive sealing film including a sealing conductive layer and a polymer layer be provided separately to achieve such a configuration.

[0013] Patent Document 2 discloses a bipolar lithium secondary battery including a bipolar unit, wherein a polymer film attached to the edge of a current collector separates electrolytes adjacent to electrodes exhibiting different polarities, and prevents mutual movement of the separated electrolytes.

[0014] However, Patent Document 2 is limited to a configuration that requires a separate polymer film in addition to the entire collector.

[0015] Therefore, there is a need for a technology capable of preventing movement of electrolyte between bipolar electrodes without requiring additional structures other than the basic bipolar electrode configuration in an electrode assembly including bipolar electrodes and a bipolar battery.

[0016] (Prior art literature)

[0017] (Patent Document 1) Chinese Patent Publication No. 112687842 (April 20, 2021)

[0018] (Patent Document 2) Korean Patent Publication No. 2020-0143281 (December 23, 2020)

[0019]

[0020] The present invention is intended to solve the above-mentioned problem, and aims to provide a bipolar electrode capable of preventing movement of electrolyte between bipolar electrodes while simplifying the structure of the bipolar electrode by applying a polymer film having a conductive layer added to the center and heat-sealing capability at the outer periphery as a current collector of the bipolar electrode, an electrode assembly including the same, a bipolar battery including the electrode assembly, and a method for manufacturing the bipolar battery.

[0021]

[0022] A bipolar electrode according to the present invention for achieving this purpose may include a current collector including a polymer film and a conductive layer added to at least a portion of an outer surface and an inner surface of the polymer film, a positive electrode formed on a first surface of the current collector, and a negative electrode formed on a second surface of the current collector.

[0023] The polymer film may include a first region having a through hole into which a conductive material of the conductive layer added to both outer surfaces is introduced and received, and a second region located on the outer periphery of the first region and having no through hole.

[0024] The above conductive layer can be added to the first region among the first and second surfaces.

[0025] The anode may be positioned on the conductive layer of the first surface, and the cathode may be positioned on the conductive layer of the second surface.

[0026] A separator may be further added to the outer surface of either the positive or negative electrode.

[0027] The separator may be thermally bonded to at least a portion of the positive or negative electrode to which the separator is added, and the second region of the polymer film.

[0028] The present invention provides an electrode assembly in which the bipolar electrodes are stacked, wherein the bipolar electrodes in the electrode assembly can be thermally bonded to each other at the outer periphery of the polymer film of the current collector.

[0029] A unit electrode is formed by partitioning the outer periphery of the polymer film by heat fusing, and an electrolyte injected into the unit electrode can be separated from an electrolyte injected into another adjacent unit electrode.

[0030] The uppermost bipolar electrode has an electrode layer formed only on the lower surface of the current collector, the lowermost bipolar electrode has an electrode layer formed only on the upper surface of the current collector, and the remaining bipolar electrodes, excluding the uppermost bipolar electrode and the lowermost bipolar electrode, may have an anode formed on the first surface of the current collector and a cathode formed on the second surface.

[0031] A support member is additionally arranged in the second region of the above-mentioned collector, and the support member can be thermally fused to the second region of the above-mentioned collector.

[0032] The present invention provides a bipolar battery in which the electrode assembly is housed in a battery case, wherein in the bipolar battery, the uppermost bipolar electrode and the lowermost bipolar electrode in the electrode assembly include electrode terminals.

[0033] The present invention provides a method for manufacturing the bipolar battery. Specifically, the method may include a first step of preparing a bipolar electrode, a second step of manufacturing an electrode assembly by stacking the bipolar electrodes, a third step of heating three outer peripheries of the electrode assembly except for one outer periphery among the four outer peripheries thereof to thermally fuse a current collector, a fourth step of injecting an electrolyte into the electrode assembly, a fifth step of heating the one outer periphery to thermally fuse a current collector, and a sixth step of storing the electrode assembly in a battery case and sealing the battery case.

[0034] The first step may include a step 1-1 of preparing a polymer film, a step 1-2 of manufacturing a current collector by coating a conductive layer on a first area of ​​both sides of the polymer film, a step 1-3 of arranging a positive electrode on a first area of ​​a first surface of the current collector and arranging a negative electrode on a first area of ​​a second surface of the current collector, and a step 1-4 of laminating a separator on an upper surface of one of the positive electrode and the negative electrode.

[0035] The uppermost bipolar electrode and the lowermost bipolar electrode of the above electrode assembly include electrode terminals.

[0036] The present invention can also be provided in a form in which various means for solving the above problem are combined.

[0037]

[0038] In the present invention, a portion of a polymer film of a current collector to which a positive electrode and a negative electrode are applied is formed with a conductive layer on both sides of the polymer film, so that an electrical connection is formed so that electrons can move within the conductive layer, and the outer periphery of the polymer film to which the positive electrode and negative electrode are not applied can be sealed by heat fusion.

[0039] Therefore, not only can a serial connection be formed between the positive and negative electrodes through the polymer film, but also the movement of electrolyte between neighboring unit electrodes can be blocked.

[0040]

[0041] Figure 1 is an exploded perspective view of a bipolar electrode according to the present invention.

[0042] Figure 2 is a vertical cross-sectional exploded view of the bipolar electrode of Figure 1.

[0043] Figure 3 is a vertical cross-sectional view of a bipolar electrode of the present invention with a separator added.

[0044] Figure 4 is an electrode assembly in which bipolar electrodes are stacked according to the first embodiment.

[0045] Figure 5 is a perspective view showing the process of heat-melting the electrode assembly of Figure 4.

[0046] Figure 6 is an electrode assembly in which bipolar electrodes are stacked according to the second embodiment.

[0047] Fig. 7 is a perspective view showing the process of heat-melting the electrode assembly of Fig. 6.

[0048]

[0049] Hereinafter, with reference to the attached drawings, embodiments of the present invention will be described in detail, so that those skilled in the art can easily implement the present invention. When describing the operating principles of the embodiments of the present invention in detail, detailed descriptions of known functions or components will be omitted if they are deemed to unnecessarily obscure the gist of the present invention.

[0050] Parts with similar functions and actions are designated by the same drawing reference numerals throughout the drawings. Throughout the specification, when a part is said to be connected to another part, this includes not only direct connections but also indirect connections with other elements intervening. Furthermore, inclusion of a component does not exclude other components unless otherwise specifically stated, but rather implies the inclusion of additional components.

[0051] The description that concretizes or adds to the components may be applied to all inventions unless there is a special limitation, and is not limited to the description of a specific invention.

[0052] Throughout the description and claims of the invention herein, the singular includes the plural unless otherwise stated.

[0053] Throughout the description and claims of the present invention, the term "or" includes "and" unless otherwise stated. Therefore, "comprising A or B" means all three cases of including A, including B, or including A and B.

[0054] The present invention is described in detail with examples according to the drawings.

[0055] Fig. 1 is an exploded perspective view of a bipolar electrode according to the present invention, and Fig. 2 is an exploded vertical cross-sectional view of the bipolar electrode of Fig. 1.

[0056] In general, a bipolar electrode is configured such that a positive electrode mixture layer and a negative electrode mixture layer are added to each side of a current collector, and electrons can move between the positive and negative electrodes through the current collector, so that current flows in the thickness direction of the electrode within the battery cell. However, since there is a risk of an internal short circuit occurring if the electrolyte is transmitted across the current collector of the bipolar electrode, it is necessary to block the movement of the electrolyte between adjacent unit electrodes.

[0057] Referring to FIGS. 1 and 2, a bipolar electrode according to the present invention has a positive electrode (200) positioned on a first surface (121) of a current collector (100) and a negative electrode (300) positioned on a second surface (122). The current collector (100) includes a polymer film (110) and a conductive layer (120), and the polymer film (110) includes a first region (111) having a through hole through which a conductive material of the conductive layer (120) added to both outer surfaces is introduced and received, and a second region (112) located on the outer periphery of the first region (111) and having no through hole.

[0058] The polymer film (110) may include at least one selected from the group consisting of polyethylene terephthalate (PET), polypropylene, polyethylene, polystyrene, polyvinyl chloride, polyimide, and polyamide.

[0059] The above through hole may be configured in a through-hole form so that a conductive material of a conductive layer added to the outer surface of the polymer film can penetrate the polymer film and move to the opposite outer surface, and for example, the first region may be configured in a mesh structure.

[0060] The diameter of the above-mentioned through hole may be configured to be tens of micrometers to several millimeters in size, but the size is not particularly limited as long as the conductive material of the conductive layer added to each of both sides of the polymer film can flow in and pass through.

[0061] However, if the size of the through hole is too small, it is difficult for the conductive material to flow in, and if the size of the through hole is too large, there is a risk of the bipolar electrode breaking when bent, so this is not desirable.

[0062] The conductive layer (120) is added to at least a portion of the outer surface and the inner surface of the polymer film (110), and is added to the first region (111) among the first surface (121) and the second surface (122) of the current collector (100). Therefore, the conductive material constituting the conductive layer (120) can be added to the surface of the first region (111) and at least a portion of the through-holes formed in the first region (111). In this way, by adding the conductive material to the outer surface of the insulating polymer film (110) and the inner surface of the through-hole, the current collector can function as an electrically conductive current collector. In addition, the conductive material added to the first region (111) fills the inside of the through-hole, and the conductive material added to each of the outer surfaces of both sides of the polymer film (110) can be connected through the through-hole, thereby forming an electrical connection path.

[0063] The anode (200) is located on the conductive layer (120) of the first surface (121), and the cathode (300) is located on the conductive layer (120) of the second surface (122).

[0064] In the current collector (100) between the positive electrode (200) and the negative electrode (300), the first region (111) of the polymer film (110) is filled with a conductive material in the through hole, so that the positive electrode (200) and the negative electrode (300) can be connected in series as electrons move between them through the conductive material.

[0065] Meanwhile, the second region (112) is a region where the positive electrode (200) and negative electrode (300) are not arranged, and has a polymer film (110) without a through hole. Therefore, the second region (112) can be thermally bonded after laminating the electrode assembly. When the outer periphery of the current collector is thermally bonded in this way, an independent space is formed between the current collectors of adjacent bipolar electrodes.

[0066] Components arranged within the independent space formed in this way constitute individual unit electrodes, which can prevent electrolyte from moving between neighboring unit electrodes.

[0067] Meanwhile, the conductive layer (120) formed on the first surface (121) of the collector (100) and the conductive layer (120) formed on the second surface (122) may be composed of the same material or may be composed of different materials.

[0068] For example, the conductive layer (120) formed on the first surface (121) and the conductive layer (120) formed on the second surface (122) may be composed of any one selected from the group consisting of aluminum, copper, and nickel.

[0069] Alternatively, the conductive layer (120) formed on the first surface (121) where the anode (200) is placed may be made of aluminum, and the conductive layer (120) formed on the second surface (122) where the cathode (300) is placed may be made of copper.

[0070] Figure 3 is a vertical cross-sectional view of a bipolar electrode of the present invention with a separator added.

[0071] Referring to FIG. 3, a separator (400) is further added to the bipolar electrode. When a plurality of bipolar electrodes are stacked to form an electrode assembly, physical contact between the bipolar electrodes can be blocked by the separator (400).

[0072] Figure 3 (a) illustrates a state in which a separator (400) is added to the upper surface of the anode (200), but of course, the separator (400) can be added to the lower surface of the cathode (300).

[0073] In this way, the separator (400) added to the outer surface of the positive electrode (200) or negative electrode (300) can be thermally bonded to the added positive electrode or negative electrode.

[0074] Figure 3 (b) shows a form in which a separator (400) is added that extends not only to the upper surface of the positive electrode (200) but also to the second region (112) of the polymer film of the current collector (100).

[0075] Even when an extended-shaped separator (400) is added as in Fig. 3 (b), the separator (400) can be added not only to the upper surface of the positive electrode, but also to the lower surface of the negative electrode (300) and the second region (112) of the polymer film of the current collector (100).

[0076] The separator (400) can be thermally bonded to the surface of the positive electrode (200) or negative electrode (300) and the second region (112). Stable adhesion between the electrode to which the separator is added and the current collector can be ensured.

[0077] A method for manufacturing a bipolar electrode according to the present invention may include a step 1-1 of preparing a polymer film, a step 1-2 of manufacturing a current collector by coating a conductive layer on a first area among both sides of the polymer film, a step 1-3 of arranging a positive electrode on a first area of ​​a first surface of the current collector and arranging a negative electrode on a first area of ​​a second surface of the current collector, and a step 1-4 of laminating a separator on an upper surface of one of the positive electrode and the negative electrode.

[0078] Additionally, a process of arranging the positive and negative electrodes on the above-described collector and stacking the separator, and then heating and pressurizing the bipolar electrode may be further included, so that the separator is fused to the surface of the bipolar electrode.

[0079] Figure 4 is an electrode assembly in which bipolar electrodes are stacked according to the first embodiment.

[0080] Referring to FIG. 4, the electrode assembly (1000) is formed by stacking bipolar electrodes in the form of FIG. 3 (a).

[0081] The picture above in Fig. 4 shows an electrode assembly (1000) manufactured by stacking multiple bipolar electrodes, and the picture below shows a state in which the current collector (100) of the electrode assembly (1000) is heated so that the second region, which is the outer periphery of the current collector (100), is heat-fused.

[0082] The electrode assembly (1000) has three bipolar electrodes (1100) stacked on top of the current collector (100) with the positive electrode (200) positioned on the top surface and the negative electrode (300) positioned on the bottom surface. The uppermost bipolar electrode (1200) has the negative electrode (300) positioned only on the bottom surface of the current collector (100), and the lowest bipolar electrode (1300) has the positive electrode (200) positioned only on the top surface of the current collector (100).

[0083] The number of bipolar electrodes (1100) in the electrode assembly (1000) illustrated in FIG. 4 may vary as needed.

[0084] The uppermost bipolar electrode (1200) and the lowermost bipolar electrode (1300) of the electrode assembly (1000) include electrode terminals.

[0085] The electrode terminal may include an electrode lead or an electrode tab, and the electrode terminal may include a main body portion coupled to the uppermost bipolar electrode and the lowermost bipolar electrode, the main body portion having a planar area equal to or smaller than the planar area of ​​the uppermost bipolar electrode and the lowermost bipolar electrode, and an extension portion extending from the main body portion to one outer periphery and protruding beyond the outer periphery of the uppermost bipolar electrode and the lowermost bipolar electrode.

[0086] Specifically, the uppermost bipolar electrode (1200) of the electrode assembly (1000) contains only a negative electrode, and the lowermost bipolar electrode (1300) contains only a positive electrode, so that a negative terminal (301) is coupled to the upper surface of the uppermost bipolar electrode (1200), and a positive terminal (201) is coupled to the lower surface of the lowermost bipolar electrode (1300).

[0087] Unlike as shown in FIG. 4, the positive terminal (201) and the negative terminal (301) may include a main body portion having a size that covers the entire uppermost bipolar electrode (1200) and the lowermost bipolar electrode (1300), and an extension portion that extends from the main body portion to one outer periphery and protrudes outside the battery case when stored in the battery case.

[0088] Alternatively, the area of ​​the main body may be configured to cover at least a portion of the outer surface of the uppermost bipolar electrode (1200) and the lowermost bipolar electrode (1300), and the extension portion may be configured to be extended so as to protrude outside the electrode case.

[0089] In this case, the electrode assembly (1000) including the bipolar electrodes is configured such that a series connection is formed between the electrodes, and when the electrode assembly (1000) is stored in the battery case, only the positive terminal (201) and the negative terminal (301) attached to each of the two ends of the series-connected bipolar electrodes can be configured to extend outside the battery case.

[0090] By heating the outer periphery of the electrode assembly (1000), the outer periphery of the polymer films (110) of the current collectors (100) are thermally fused to each other. As the polymer films (110) are thermally fused in this way, a pocket-shaped space (510) is formed, and the inside and the outside of the pocket-shaped space (510) are separated. A unit electrode (500) is formed by having the space (510) partitioned by the polymer film as a single unit. When an electrolyte is individually injected into the unit electrode (500) and the outer periphery of the polymer film (110) is thermally fused, the electrolyte injected into the unit electrode (500) is separated from the electrolyte injected into another adjacent unit electrode.

[0091] A method for manufacturing a bipolar battery according to the present invention comprises a first step of preparing a bipolar electrode, a second step of manufacturing an electrode assembly by stacking the bipolar electrodes, a third step of heating three outer peripheries of the electrode assembly except one outer periphery among four outer peripheries thereof to thermally fuse a current collector, a fourth step of injecting an electrolyte into the electrode assembly, a fifth step of heating the one outer periphery to thermally fuse a current collector, and a sixth step of storing the electrode assembly in a battery case and sealing the battery case.

[0092] Figure 5 is a perspective view showing the process of heat-melting the electrode assembly of Figure 4.

[0093] Referring to Fig. 5, after preparing the electrode assembly of Fig. 4 by stacking bipolar electrodes, as shown in Fig. 5 (a), among the four outer peripheries of the electrode assembly, the outer peripheries (112a, 112b, 112c) are pressurized and heated to thermally fuse, thereby forming a pocket-shaped space in which only one outer periphery (112d) is open. The reason why only one outer periphery (112d) is not thermally fused is to inject an electrolyte in this direction.

[0094] As shown in Fig. 5 (b), the electrolyte is injected in the direction of the arrow, and the electrolyte is injected individually into each pocket-shaped space.

[0095] Figure 5 (c) shows a state in which the outer periphery (112d) is pressurized and heated to achieve thermal fusion.

[0096] Afterwards, although omitted in Fig. 5, the electrode assembly is housed in a battery case and sealed.

[0097] The battery case can be a pouch-shaped case made of a laminate sheet including a resin layer and a metal layer, or a square case made of a metal material.

[0098] Meanwhile, as shown in Fig. 5 (a), an electrode assembly with three outer peripheries (112a, 112b, 112c) heat-sealed is first placed in a battery case, and then an electrolyte is injected into the inside of the electrode assembly, and a bipolar battery can be manufactured in the order of heat-sealing of the outer periphery (112d) of the electrode assembly and sealing of the battery case.

[0099] In this way, since the bipolar battery according to the present invention includes a current collector in the form of a polymer film surface having a through hole only in the center thereof and a conductive layer added thereto, the outer periphery of the polymer film without the through hole can be thermally fused to form a partitioned space. Accordingly, a series connection can be formed between adjacent bipolar electrodes, while preventing the movement of electrolyte between adjacent unit electrodes.

[0100] Figure 6 is an electrode assembly in which bipolar electrodes are stacked according to the second embodiment.

[0101] Referring to FIG. 6, the electrode assembly including a bipolar electrode according to the second embodiment is different from the electrode assembly including a bipolar electrode according to the first embodiment illustrated in FIG. 4 in that a support member (600) is added between the current collectors (100).

[0102] The support member (600) is arranged in the second region of the current collectors (100) to enable the shape of the electrode assembly to be maintained, to block the movement of the electrolyte, and to prevent a side reaction with the electrolyte, so that the material thereof is not particularly limited, and for example, it may be composed of one or more selected from the group consisting of polyethylene terephthalate (PET), polypropylene, polyethylene, polystyrene, polyvinyl chloride, polyimide, and polyamide, and specifically, it may be composed of the same material as the polymer film.

[0103] FIG. 6 illustrates that the height of the support member (600) corresponds to the sum of the thicknesses of the cathode (300), the separator (400), and the anode (200), but, of course, the height of the support member (600) may be smaller than the sum of the thicknesses of the cathode (300), the separator (400), and the anode (200).

[0104] When a support member (600) is added, each of the upper and lower surfaces of the support member (600) can be heat-fused to the second region of the current collector (100).

[0105] In addition, the description of the electrode assembly in which bipolar electrodes are laminated according to the second embodiment can be applied in the same manner as the description of the electrode assembly in which bipolar electrodes are laminated according to the first embodiment.

[0106] Fig. 7 is a perspective view showing the process of heat-melting the electrode assembly of Fig. 6.

[0107] Referring to FIG. 7, the support member (600) can be configured in a square frame shape, and when stacking bipolar electrodes, the bipolar electrodes and the support member can be alternately stacked so that the support member (600) is positioned between the current collectors (100). Thereafter, as shown in FIG. 7 (a), among the four outer peripheries of the electrode assembly, the outer peripheries (112a, 112b, 112c) are pressurized and heated to thermally fuse, thereby forming a pocket-shaped space in which only one outer periphery (112d) is open.

[0108] The electrolyte is injected in a state where a gap is created between the current collector (100) and the support member (600) in one direction of the outer periphery (112d) that is not thermally fused. At this time, the electrolyte is injected individually into each pocket-shaped space.

[0109] After the electrolyte injection is completed, the outer periphery (112d) on one side is pressurized and heated to heat-seal.

[0110] Afterwards, although omitted in Fig. 7, the electrode assembly is housed in a battery case and sealed.

[0111] Meanwhile, as shown in Fig. 7 (a), an electrode assembly with three outer peripheries (112a, 112b, 112c) heat-sealed is first placed in a battery case, and then an electrolyte is injected into the inside of the electrode assembly, and a bipolar battery can be manufactured in the order of heat-sealing of the outer periphery (112d) of the electrode assembly and sealing of the battery case.

[0112] In addition, the description of the electrode assembly in which bipolar electrodes are laminated according to the second embodiment can be applied in the same manner as the description of the electrode assembly in which bipolar electrodes are laminated according to the first embodiment, so detailed descriptions are omitted.

[0113]

[0114] Anyone with ordinary knowledge in the field to which the present invention pertains will be able to perform various applications and modifications within the scope of the present invention based on the above contents.

[0115] (Explanation of symbols)

[0116] 100: Whole house

[0117] 110: Polymer film

[0118] 111: Area 1

[0119] 112: Area 2

[0120] 112a, 112b, 112c, 112d: Outer perimeter

[0121] 120: Conductive layer

[0122] 121: Page 1

[0123] 122: Page 2

[0124] 200: Bipolar

[0125] 201: Positive terminal

[0126] 300: Cathode

[0127] 301: Negative terminal

[0128] 400: Membrane

[0129] 500: Unit electrode

[0130] 510: Space

[0131] 600: Support member

[0132] 1000: Electrode assembly

[0133] 1100, 1200, 1300: Bipolar electrodes

Claims

1. A current collector comprising a polymer film and a conductive layer added to at least a portion of an outer surface and an inner surface of the polymer film; An anode formed on the first surface of the above-mentioned collector; and A cathode formed on the second surface of the above-mentioned collector; A bipolar electrode including:

2. In paragraph 1, The above polymer film, A first region having a through hole into which a conductive material of the conductive layer added to both outer surfaces is introduced and received, and A bipolar electrode located on the outer periphery of the first region and including a second region without the through hole.

3. In paragraph 2, The above conductive layer is a bipolar electrode added to the first region among the first and second surfaces.

4. In paragraph 3, A bipolar electrode in which the anode is located on the conductive layer of the first surface, and the cathode is located on the conductive layer of the second surface.

5. In paragraph 1, A bipolar electrode in which a separator is further added to the outer surface of one of the positive and negative electrodes.

6. In paragraph 5, The above separator is, A bipolar electrode, wherein the anode or cathode to which the separator is added is thermally bonded to at least a portion of the second region of the polymer film.

7. In an electrode assembly comprising bipolar electrodes stacked according to any one of claims 1 to 6, The above bipolar electrodes are an electrode assembly in which the outer periphery of the polymer film of the current collector is heat-fused to each other.

8. In paragraph 7, A unit electrode is formed by partitioning the outer periphery of the heat-fused polymer film, An electrode assembly in which the electrolyte injected into the unit electrode is separated from the electrolyte injected into another adjacent unit electrode.

9. In paragraph 8, The top bipolar electrode has an electrode layer formed only on the lower surface of the current collector. The lowest bipolar electrode has an electrode layer formed only on the upper surface of the current collector. An electrode assembly in which the remaining bipolar electrodes, excluding the uppermost bipolar electrode and the lowermost bipolar electrode, have a positive electrode formed on the first surface of the current collector and a negative electrode formed on the second surface.

10. In paragraph 7, A support member is additionally placed in the second region of the above-mentioned collector, The above support member is an electrode assembly that is thermally fused to the second region of the current collector.

11. In a bipolar battery in which the electrode assembly according to Article 7 is housed in a battery case, A bipolar battery in which the uppermost bipolar electrode and the lowermost bipolar electrode in the above electrode assembly include electrode terminals.

12. A method for manufacturing a bipolar battery according to Article 11, Step 1: Preparing the bipolar electrode; A second step of manufacturing an electrode assembly by stacking the above bipolar electrodes; A third step of heating the outer periphery of the electrode assembly in four directions, excluding one outer periphery, and thermally bonding the current collector; A fourth step of injecting an electrolyte into the electrode assembly; A fifth step of heating the outer periphery of the above-mentioned one side to thermally fuse the entire body; and A sixth step of storing the electrode assembly in a battery case and sealing the battery case; A method for manufacturing a bipolar battery comprising:

13. In paragraph 12, The above first step is, Step 1-1: Preparing a polymer film; Step 1-2 of manufacturing a current collector by coating a conductive layer on the first area of ​​both sides of the polymer film; Step 1-3 of placing a positive electrode in a first region of a first surface of the current collector and placing a negative electrode in a first region of a second surface of the current collector; and Steps 1-4 of laminating a separator on the upper surface of one of the positive and negative electrodes; A method for manufacturing a bipolar battery comprising:

14. In paragraph 12, A method for manufacturing a bipolar battery, wherein the uppermost bipolar electrode and the lowermost bipolar electrode of the electrode assembly include electrode terminals.

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