Bipolar battery and battery device comprising same

Abstract

A bipolar battery according to embodiments comprises a cell stack including a plurality of bipolar cells stacked in a first direction, a first bus bar assembly disposed on one side of the cell stack, and a second bus bar assembly disposed on the other side of the cell stack, wherein the first bus bar assembly includes a pair of first terminals electrically connected to the cell stack, and the second bus bar assembly includes a pair of second terminals electrically connected to the cell stack.

Description

Bipolar cell and battery device including the same

[0001] The present invention relates to a bipolar cell and a battery device including the same.

[0002] This application claims the benefit of priority based on Korean Patent Application No. 2025-0002329 filed January 7, 2025 and Korean Patent Application No. 2025-0202172 filed December 17, 2025, and all contents disclosed in the documents of said Korean patent applications are incorporated herein as part of this specification.

[0003] Secondary batteries are rechargeable and dischargeable, so they are widely used in mobile devices such as digital cameras, mobile phones, and laptops, and recently, they are receiving attention as an energy source for electric vehicles and energy storage systems (ESS).

[0004] As large capacity and high output power are required in electric vehicles and energy storage systems, a new secondary battery structure capable of stably providing high-voltage power is required, and an efficient connection structure between multiple secondary batteries having such a new structure is required.

[0005] The present invention is designed to solve at least some of the problems of the prior art described above, and provides a bipolar battery and a battery device including the same that can freely configure series or parallel connections while simplifying the electrical connection structure.

[0006] To achieve the above objective, embodiments of the present invention provide a bipolar cell comprising a cell stack including a plurality of bipolar cells stacked along a first direction, a first busbar assembly disposed on one side of the cell stack, and a second busbar assembly disposed on the other side of the cell stack, wherein the first busbar assembly includes a pair of first terminals electrically connected to the cell stack, and the second busbar assembly includes a pair of second terminals electrically connected to the cell stack.

[0007] In the embodiments, the bipolar cell may further include a pressure plate positioned facing the cell stack in a first direction, a first end cover coupled to the pressure plate and covering the cell stack and a first busbar assembly, and a second end cover coupled to the pressure plate and covering the cell stack and a second busbar assembly.

[0008] In the embodiments, a pair of first terminals may protrude further than the outer surface of the first end cover, and a pair of second terminals may protrude further than the outer surface of the second end cover.

[0009] In the embodiments, the cell stack and the first busbar assembly are arranged facing each other in a second direction perpendicular to the first direction, and a pair of first terminals may include a negative terminal and a positive terminal spaced apart from each other in a third direction perpendicular to both the first direction and the second direction.

[0010] In the embodiments, the cell stack may include a first current collection plate and a second current collection plate spaced apart in a first direction with at least one of the plurality of bipolar cells in between.

[0011] In the embodiments, the first busbar assembly or the second busbar assembly may further include a plurality of internal busbars electrically connected to the first current collector plate and the second current collector plate, and a busbar frame supporting the plurality of internal busbars.

[0012] In the embodiments, the bipolar cell further includes a pressure plate positioned facing the cell stack in a first direction, and the busbar frame can be coupled with the pressure plate.

[0013] In the embodiments, a plurality of internal busbars are seated on one surface of the busbar frame, and a first current collection plate or a second current collection plate may include a connecting plate that penetrates from the opposite side of the busbar frame toward the one surface and is connected to one of the plurality of internal busbars.

[0014] In the embodiments, the bipolar cell further includes a third current collector plate disposed between a first current collector plate and a second current collector plate, the first current collector plate and the second current collector plate have the same electrical polarity, and the first current collector plate and the third current collector plate may have opposite electrical polarities.

[0015] In the embodiments, the first busbar assembly further comprises a first internal busbar electrically connected to a first current collector plate and a second current collector plate and a second internal busbar electrically connected to a third current collector plate, and either one of the pair of first terminals may be electrically connected to the first internal busbar and the other of the pair of first terminals may be electrically connected to the second internal busbar.

[0016] In the embodiments, a pair of first terminals and a pair of second terminals may be arranged so as to be rotationally symmetric with respect to the central axis of the bipolar cell.

[0017] In the embodiments, the cell stack comprises a first sub-stack in which at least two of a plurality of bipolar cells are stacked so as to be serially connected to each other, and a second sub-stack in which at least two of a plurality of bipolar cells are stacked so as to be serially connected to each other, and the first sub-stack and the second sub-stack may be connected in parallel to each other.

[0018] In the embodiments, the cell stack further comprises a third sub-stack stacked such that at least two of the plurality of bipolar cells are connected in series with each other, the first sub-stack, the second sub-stack, and the third sub-stack are stacked along one direction, and the third sub-stack may be connected in parallel with the first sub-stack and the second sub-stack.

[0019] In embodiments, a battery device is provided comprising a first bipolar cell and a second bipolar cell arranged facing each other, wherein the first bipolar cell and the second bipolar cell are each bipolar cells according to claim 1, and a pair of first terminals of the first bipolar cell are electrically connected to a pair of second terminals of the second bipolar cell.

[0020] In the embodiments, at least a portion of the first terminals of a pair of first bipolar cells may overlap with the second terminals of a pair of second bipolar cells in the stacking direction of a plurality of bipolar cells.

[0021] In the embodiments, the first bipolar cell and the second bipolar cell can be connected in parallel with each other.

[0022] According to the embodiments, a bipolar cell and a battery device including the same can be provided, which can freely configure a series connection or a parallel connection while simplifying the electrical connection structure.

[0023] In addition, according to the embodiments, electrical resistance can be reduced in the connection structure between a plurality of bipolar batteries.

[0024] In addition, according to the embodiments, the number of components for electrical connection between multiple bipolar cells can be reduced, thereby increasing the manufacturing efficiency of the battery device and reducing manufacturing costs.

[0025] FIG. 1 is a perspective view of a battery device including a bipolar cell according to one embodiment.

[0026] FIG. 2 is a perspective view of a bipolar battery according to one embodiment.

[0027] FIG. 3 is an exploded perspective view of a bipolar battery according to one embodiment.

[0028] FIG. 4 is an exploded perspective view of a cell stack included in a bipolar battery according to one embodiment.

[0029] FIG. 5 is an exploded perspective view of a bipolar cell included in a bipolar battery according to one embodiment.

[0030] FIG. 6 is an exemplary cross-sectional view of a bipolar cell along line II' of FIG. 5.

[0031] FIG. 7 is a perspective view of a first busbar assembly of a bipolar battery according to one embodiment.

[0032] FIG. 8 is an exemplary exploded perspective view of a first busbar assembly according to one embodiment.

[0033] FIG. 9 is a perspective view of a second busbar assembly of a bipolar battery according to one embodiment.

[0034] FIG. 10 is an exploded perspective view of a cell stack included in a bipolar battery according to various embodiments.

[0035] FIG. 11 is a reference diagram for explaining the connection between two bipolar batteries according to one embodiment.

[0036] FIG. 12 is a part of a side view of a bipolar battery according to one embodiment.

[0037] FIG. 13 is a part of a side view of a bipolar battery according to one embodiment.

[0038] FIG. 14 is a part of a combined cross-sectional view of two bipolar batteries according to one embodiment.

[0039] Prior to the detailed description of the present invention, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings. Instead, they should be interpreted in a sense and concept consistent with the technical spirit of the present invention, based on the principle that the inventor may appropriately define the concept of the terms to best describe his invention. Accordingly, the embodiments described in this specification and the configurations illustrated in the drawings are merely the most preferred embodiments of the present invention and do not represent all aspects of the technical spirit of the present invention. Therefore, it should be understood that various equivalents and modifications capable of replacing them may exist at the time of filing this application.

[0040] Identical reference numbers or symbols in each drawing attached to this specification represent parts or components that perform substantially the same function. For convenience of explanation and understanding, the same reference numbers or symbols may be used to describe different embodiments. That is, even if components having the same reference number are depicted in multiple drawings, the multiple drawings do not all represent a single embodiment.

[0041] In the following description, singular expressions include plural expressions unless the context clearly indicates otherwise. Terms such as "comprising" or "constituting" are intended to specify the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0042] In addition, it should be noted in advance that expressions such as upper side, top, lower side, bottom, side, front, and rear in the following description are based on the direction depicted in the drawings, and may be expressed differently if the direction of the object changes.

[0043] Additionally, in this specification and claims, terms including ordinal numbers, such as "first," "second," etc., may be used to distinguish between components. These ordinal numbers are used to distinguish identical or similar components from one another, and the meaning of the terms should not be limited by the use of such ordinal numbers. For example, the order of use or arrangement of components combined with such ordinal numbers should not be limited by the number. If necessary, each ordinal number may be used interchangeably.

[0044] Embodiments of the present invention will be described below with reference to the attached drawings. However, the scope of the present invention is not limited to the embodiments presented. For example, a person skilled in the art who understands the scope of the present invention may propose other embodiments that fall within the scope of the concept of the present invention by adding, changing, or deleting components, and such embodiments shall also be deemed to be within the scope of the concept of the present invention. In the drawings, the shapes and sizes of elements may be exaggerated for clearer explanation.

[0045] FIG. 1 is a perspective view of a battery device (1) including a bipolar battery (10) according to one embodiment.

[0046] A battery device (1) according to one embodiment may include one or more bipolar cells (10) and a housing (20).

[0047] A bipolar cell (10) may include one or more bipolar cells (e.g., 100 in FIG. 4 to 6) comprising a bipolar electrode (e.g., 110 in FIG. 6) having a negative electrode layer formed on one side of a current collector (e.g., 111 in FIG. 6) and a positive electrode layer formed on the other side. The bipolar cell (10) will be described in detail later with reference to FIG. 2 to 6.

[0048] In various embodiments of the present disclosure, the term "battery device (1)" collectively refers to an energy storage device comprising a battery cell capable of storing or outputting energy (e.g., a bipolar cell (100) described in FIGS. 2 to 6). For example, the term "battery device (1)" of the present disclosure may be understood as various types of energy storage devices, including battery packs or energy storage systems, as well as battery modules.

[0049] Referring further to FIG. 1, one or more bipolar cells (10) included in the battery device (1) can be accommodated in a housing (20).

[0050] The housing (20) may include a lower plate (21) and a plurality of support beams (22). A bipolar battery (10) may be seated in the inner receiving space formed by the lower plate (21) and the plurality of support beams (22). Meanwhile, although not shown in FIG. 1, the housing (20) may further include an upper plate (not shown) positioned on top of the plurality of support beams (22) to close the receiving space of the housing (20).

[0051] The lower plate (21) can form the lower surface of the housing (20). In various embodiments, the lower plate (21) may be provided as a square plate-shaped member or a polygonal plate-shaped member other than a square, but the shape of the lower plate (21) is not necessarily limited thereto.

[0052] The support beam (22) can be connected to the lower plate (21). For example, referring to FIG. 1, at least some of the plurality of support beams (22) can form the sides of the housing (20).

[0053] The lower plate (21) or the support beam (22) may be formed of a metal material having high rigidity. For example, at least a portion of the lower plate (21) and the support beam (22) may include aluminum. If the lower plate (21) includes aluminum, due to the excellent thermal conductivity of aluminum, the thermal energy generated in the bipolar cell (10) can be expected to be rapidly dissipated to the outside of the battery device (1).

[0054] Hereinafter, a bipolar battery (10) according to embodiments of the present disclosure will be described in more detail with reference to FIGS. 2 to 6.

[0055] FIG. 2 is a perspective view of a bipolar battery (10) according to one embodiment.

[0056] FIG. 3 is an exploded perspective view of a bipolar battery (10) according to one embodiment.

[0057] FIG. 4 is an exploded perspective view of a cell stack (CS) included in a bipolar battery (10) according to one embodiment.

[0058] FIG. 5 is an exploded perspective view of a bipolar cell (100) included in a bipolar battery (10) according to one embodiment.

[0059] FIG. 6 is an exemplary cross-sectional view of a bipolar cell (100) along the line II' of FIG. 5.

[0060] Since the bipolar battery (10) described in FIGS. 2 to 6 corresponds to the bipolar battery (10) described in FIG. 1, descriptions that overlap with FIG. 1 may be omitted.

[0061] Referring to FIGS. 2 to 4 together, in one embodiment, a bipolar battery (10) may include a cell stack (CS) comprising a plurality of bipolar cells (100), a plurality of pressure plates (300) covering the upper and lower surfaces of the cell stack (CS), an end cover (400) covering the side of the cell stack (CS), and a plurality of terminals (530, 630) electrically connected to the cell stack (CS).

[0062] A bipolar cell (10) according to various embodiments of the present disclosure may include a cell stack (CS) in which a plurality of bipolar cells (100) are stacked.

[0063] A plurality of bipolar cells (100) included in a cell stack (CS) can be stacked along one direction (e.g., the Z-axis direction) and electrically connected to each other. In the following description, the stacking direction of the plurality of bipolar cells (100) included in the cell stack (CS) is referred to as the "cell stacking direction." Additionally, the cell stacking direction may also be referred to as the "first direction."

[0064] In one embodiment, the bipolar cell (10) can be placed in the housing (20) of the battery device (1) in a direction approximately parallel to the cell stacking direction. Through such a placement structure, a plurality of bipolar cells (100) having a large-area flat structure can be intensively arranged in a limited space within the housing (20).

[0065] A plurality of bipolar cells (100) included in a cell stack (CS) may be electrically connected to a busbar assembly (500, 600) through current collection plates (210, 220, 230). For example, the cell stack (CS) may include one or more current collection plates (210, 220, 230) that are stacked along a first direction (e.g., Z-axis direction) together with a plurality of bipolar cells (100) and are electrically connected to a plurality of bipolar cells (100), and the plurality of bipolar cells (100) may be electrically connected to a busbar assembly (500, 600) and a terminal (530, 630) through these current collection plates (210, 220, 230). The current collection plate (210, 220, 230) may be a flat member comprising a conductive material, for example, a conductive metal material such as copper or aluminum, and may be configured to electrically connect a plurality of bipolar cells (100) and a busbar assembly (500, 600).

[0066] Referring to FIGS. 3 and FIGS. 4 together, the current collection plates (210, 220, 230) may include a first current collection plate (210) positioned to face the lower surface of a stacked body in which a plurality of bipolar cells (100) are stacked, and a second current collection plate (220) positioned to face the upper surface of a stacked body in which a plurality of bipolar cells (100) are stacked. However, the specific structure of the first current collection plate (210) and the second current collection plate (220) may be provided in various structures capable of electrically connecting a plurality of bipolar cells (100) and a busbar assembly (500, 600), in addition to the flat plate structure described above.

[0067] In various embodiments of the present disclosure, the cell stack (CS) may include a plurality of sub-stacks (CSa, CSb). For example, referring to FIG. 4, the cell stack (CS) may include a first sub-stack (CSa) and a second sub-stack (CSb) stacked along a first direction (Z-axis direction).

[0068] In various embodiments of the present disclosure, the first current collection plate (210) and the second current collection plate (220) may be spaced apart in a first direction (Z-axis direction) with at least one of the plurality of bipolar cells (100) in between. For example, referring to FIG. 4, the first current collection plate (210) and the second current collection plate (220) may be spaced apart in a first direction (Z-axis direction), and a first sub-stack (CSa) and a second sub-stack (CSb) may be placed between the first current collection plate (210) and the second current collection plate (220).

[0069] A plurality of sub-stacks (CSa, CSb) may each include a plurality of bipolar cells (100). A plurality of bipolar cells (100) included in any one sub-stack (CSa, CSb) may be stacked along a first direction (Z-axis direction) and electrically connected in series with each other. For example, a first sub-stack (CSa) and a second sub-stack (CSb) may each include a plurality of bipolar cells (100) that are electrically connected in series with each other while stacked along the first direction (Z-axis direction).

[0070] However, the specific configuration of the cell stack (CS) is not limited to what has been described above. For example, unlike the illustration in FIG. 4, the cell stack (CS) of the bipolar battery (10) according to the embodiments may be composed of a single stack in which a plurality of bipolar cells (100) are stacked, or may be composed of three or more sub-stacks.

[0071] In a structure in which a plurality of sub-stacks (CSa, CSb) are stacked, a current collection plate may be disposed between the plurality of sub-stacks (CSa, CSb). For example, referring to FIG. 4, a third current collection plate (230) may be disposed between a first sub-stack (CSa) and a second sub-stack (CSb) that are stacked along a first direction (Z-axis direction). In this case, the first current collection plate (210), the second current collection plate (220), and the third current collection plate (230) may each be electrically connected to a busbar assembly (500, 600). Regarding the electrical connection of the cell stack (CS), the bipolar cell (100) will be described in detail first, and then described again.

[0072] Hereinafter, with reference to FIGS. 5 and FIGS. 6, a bipolar cell (100) included in a bipolar battery (10) according to embodiments will be described.

[0073] Referring to FIG. 5, a bipolar cell (100) according to one embodiment may include an electrode assembly (EA) comprising a plurality of bipolar electrodes (110), an electrode plate (150, 160) electrically connected to the electrode assembly (EA), and a cell frame (140) coupled to the electrode plate (150, 160).

[0074] In one embodiment, the electrode assembly (EA) of the bipolar cell (100) may include an electrode stack (ES) in which a plurality of bipolar electrodes (110) and a separator (120) are alternately stacked along one direction (e.g., the Z-axis direction) and a sealing portion (130) that seals the electrode stack (ES).

[0075] A bipolar electrode (110) may have a structure in which electrode layers (112, 113) having different polarities are formed on both sides of a single current collector (111). For example, referring to FIG. 6, in one bipolar electrode (110), a first electrode layer (112) and a second electrode layer (113) having opposite electrical polarities may be disposed on one side and the opposite side of the current collector (111). For example, the first electrode layer (112) may be a negative electrode layer, and the second electrode layer (113) may be a positive electrode layer. Alternatively, the first electrode layer (112) may be a positive electrode layer, and the second electrode layer (113) may be a negative electrode layer. In each bipolar electrode (110), electrons emitted from the negative electrode layer may move to the positive electrode layer through the current collector (111).

[0076] In one embodiment, the current collector (111) may have a flat structure made of a conductive material (e.g., a conductive metal such as copper or aluminum) so as to function as a current pathway in the bipolar electrode (110). If necessary, the current collector (111) may be formed to include a porous structure or a mesh structure.

[0077] In one embodiment, the cathode layer may be formed using materials such as graphite, silicon (Si), or lithium (Li), but is not limited thereto. Additionally, the anode layer may be formed using materials such as lithium metal oxide, such as lithium cobalt oxide (LiCoO2), lithium nickel manganese cobalt oxide (NMC), or lithium iron phosphate (LFP), but is not limited thereto.

[0078] An electrode stack (ES) can be formed by stacking a plurality of bipolar electrodes (110), each having electrode layers (112, 113) formed on both sides of a current collector (111), in one direction (e.g., Z-axis direction) with a separator (120) in between. In this case, the direction in which the plurality of bipolar cells (100) are stacked and the direction in which the plurality of bipolar electrodes (110) are stacked in one bipolar cell (100) may be approximately the same direction.

[0079] In one embodiment, an electrode layer (112, 113) may be formed on only one side of a current collector (111) positioned at the top or bottom of an electrode stack (ES). For example, referring to FIG. 6, in the current collector (111) positioned at the bottom among the plurality of current collectors (111) included in the electrode stack (ES), a first electrode layer (112) may be formed on the side facing the separator (120), but a second electrode layer (113) may not be formed on the opposite side. Alternatively, in the current collector (111) positioned at the top among the plurality of current collectors (111) included in the electrode stack (ES), a second electrode layer (113) may be formed on the side facing the separator (120), but a first electrode layer (112) may not be formed on the opposite side.

[0080] A separator (120) is disposed between a plurality of bipolar electrodes (110) to prevent the bipolar electrodes (110) from coming into contact with each other and short-circuiting. For example, the separator (120) may be a porous film disposed between a plurality of bipolar electrodes (110), and the separator (120) may be impregnated with an electrolyte to enable the movement of ions between the positive electrode layer and the negative electrode layer. Alternatively, the separator (120) may be formed in the form of a gel having fluidity or may be formed as a solid. When the separator (120) is provided in the form of a gel or a solid, the possibility of leakage is reduced compared to the case where a liquid electrolyte is applied, while structural stability is improved. However, the shape of the separator (120) is not limited to that described above, and the separator (120) may be formed in any shape that enables the movement of ions while preventing the positive electrode layer and the negative electrode layer facing each other from coming into contact.

[0081] This stacked structure of multiple bipolar electrodes (110) and a separator (120) can form an electrical series structure in the electrode stack (ES). For example, referring to FIG. 6, multiple bipolar electrodes (110) can all be stacked along a first direction (Z-axis direction) with a separator (120) in between, with the first electrode layer (112) facing in the same direction, to form an electrical series structure. In this way, as the multiple bipolar electrodes (110) form a stacked structure in which they are connected in series, the bipolar cell (100) can supply high voltage and high density electrical energy.

[0082] The sealing portion (130) can surround and seal the electrode stack (ES). For example, the sealing portion (130) is formed along the perimeter of the electrode stack (ES) to primarily seal the electrode stack (ES) from the outside and protect the electrode stack (ES) from external moisture or foreign matter.

[0083] The sealing portion (130) can prevent the electrolyte from leaking out of the electrode assembly (EA). Alternatively, as described above, if the separator (120) itself is provided in the form of a gel or solid having a certain fluidity, the separator (120) may not leak out of the electrode assembly (EA) due to the sealing structure of the sealing portion (130).

[0084] The sealing portion (130) can fix and support the electrode stack (ES). The sealing portion (130) is formed to have a predetermined thickness in a direction perpendicular to the first direction (Z-axis direction), and at least a portion of the current collector (111) or the separator (120) can be inserted into and fixed to the sealing portion (130). Each bipolar electrode (110) of the electrode stack (ES) can be prevented from being displaced or misaligned from its original position due to the support structure of the sealing portion (130).

[0085] In one embodiment, the electrode stack (ES), which is sealed and surrounded by the sealing portion (130), may be arranged so that current collectors (111) are exposed at both ends in the first direction (Z-axis direction). The current collectors (111) located at both ends in the first direction (Z-axis direction) of the electrode stack (ES) may form an electrical connection with the electrode plates (150, 160). The current collector (111) located at one end in the first direction (Z-axis direction) and the current collector (111) located at the other end in the first direction (Z-axis direction) may have different electrical polarities.

[0086] In one embodiment, the bipolar cell (100) may include a plurality of electrode plates (150, 160) that cover one side and the other side of the electrode assembly (EA), respectively, and are electrically connected to the electrode assembly (EA). For example, referring to FIGS. 5 and FIGS. 6 together, the plurality of electrode plates (150, 160) may include a first electrode plate (150) that covers the lower surface of the electrode assembly (EA) and a second electrode plate (160) that covers the upper surface of the electrode assembly (EA).

[0087] The electrode plates (150, 160) may be formed of a conductive material, such as metal, in at least a portion thereof, and may be electrically connected to the electrode assembly (EA) to serve as a terminal for connecting the electrode assembly (EA) to an electrical circuit outside the bipolar cell (100). For example, in any bipolar cell (100), the lower surface of the first electrode plate (150) below the electrode assembly (EA) and the upper surface of the second electrode plate (160) above the electrode assembly (EA) may have a state in which a conductive material is widely exposed, and such a widely exposed portion of the conductive material can be utilized as a terminal. That is, the electrode assembly (EA) of any bipolar cell (100) may be electrically connected to an external electrical circuit or another bipolar cell (100) through the electrode plates (150, 160). In this way, as a large-area electrode plate (150, 160) covering the upper or lower surface of the electrode assembly (EA) is utilized as a terminal of an individual bipolar cell (100), electrical resistance can be lowered in the terminal area, and as a result, a unit cell with very small thermal energy generated by resistance can be realized.

[0088] In one embodiment, the first electrode plate (150) and the second electrode plate (160) may have opposite electrical polarities. For example, referring to FIG. 6, the first electrode plate (150) may be electrically connected to the lowest current collector (111) of the electrode stack (ES), and the second electrode plate (160) may be electrically connected to the uppermost current collector (111) of the electrode stack (ES) which has an electrically opposite polarity to the current collector (111) electrically connected to the first electrode plate (150), so that the first electrode plate (150) and the second electrode plate (160) may have opposite electrical polarities. That is, in any bipolar cell (100), one of the first electrode plate (150) and the second electrode plate (160) may be a positive terminal and the other may be a negative terminal.

[0089] A bipolar cell (100) according to one embodiment may further include a connecting member (170) that connects electrode plates (150, 160) and a bipolar electrode (110). For example, referring to FIG. 6, a connecting member (170) electrically connected to a current collector (111) may be disposed on the outermost sides of one side and the other side of an electrode assembly (EA). One side of the connecting member (170) may be electrically connected to the current collector (111) by contacting it, and the other side of the connecting member (170) may be electrically connected to the electrode plates (150, 160) by contacting them.

[0090] The connecting member (170) may be provided with a conductive foam having a predetermined length variability in the first direction (Z-axis direction), but is not limited thereto. In addition, the shape or placement position of the connecting member (170) is not limited to that shown in FIG. 6, and can have any shape as long as it can electrically connect the electrode assembly (EA) and the electrode plates (150, 160).

[0091] Alternatively, in various embodiments, the electrode assembly (EA) may have the current collector (111) in direct contact with the electrode plate (150, 160) or electrically connected through a separate means, in which case the connecting member (170) may be omitted.

[0092] In one embodiment, if necessary, a binder may be applied between the electrode assembly (EA) and the electrode plate (150, 160) to fix the mutual position between the electrode assembly (EA) and the electrode plate (150, 160). For example, the binder may be a conductive binder. However, alternatively, the electrode assembly (EA) may be electrically connected to the electrode plate (150, 160) in a state of close contact on the electrode plate (150, 160) without a separate bonding member such as a binder.

[0093] Referring to FIGS. 5 and FIGS. 6 together, the first electrode plate (150) and the second electrode plate (160) may be spaced apart in a first direction (Z-axis direction) with the electrode assembly (EA) in between. Additionally, the first electrode plate (150) and the second electrode plate (160) may be coupled to different sides of the cell frame (140) and spaced apart from each other with the cell frame (140) in between. For example, referring to FIGS. 5 and FIGS. 6, the first electrode plate (150) may be coupled to the lower side of the cell frame (140), and the second electrode plate (160) may be coupled to the upper side of the cell frame (140).

[0094] In one embodiment, the cell frame (140) may be positioned in the spaced-out space between the edge of the first electrode plate (150) and the edge of the second electrode plate (160) to form the side of the bipolar cell (100). For example, the cell frame (140) may be positioned along the perimeter of the electrode assembly (EA) to protect the side of the electrode assembly (EA) and to support the first electrode plate (150) and the second electrode plate (160) so as to maintain a gap between them.

[0095] In one embodiment, the cell frame (140) may include an insulating material so as to have sufficient rigidity to protect the electrode assembly (EA) while being electrically insulated from the electrode plates (150, 160). For example, the cell frame (140) may include a polymer resin material such as polypropylene (PP) or polycarbonate (PC) or a non-conductive metal material.

[0096] In one embodiment, the electrode plates (150, 160) may be fused and joined to the cell frame (140). For example, the electrode plates (150, 160) and the cell frame (140) may be heat-fused to each other with a sealing member (not shown) interposed between them. For example, the sealing member (not shown) may include various polymer resin films, including PP film. However, the material of the sealing member (not shown) is not limited to what is described above, and any material capable of stably fixing the electrode plates (150, 160) and the cell frame (140) to each other while maintaining airtightness may be applied without limitation.

[0097] In one embodiment, a plurality of bipolar cells (100) included in one sub-stack (CSa, CSb) may be electrically connected with their electrode plates (150, 160) in contact with each other. For example, in two bipolar cells (100) stacked adjacent to each other vertically, the first electrode plate (150) of the upper bipolar cell (100) may be in contact with the second electrode plate (160) of the lower bipolar cell (100), thereby allowing the upper bipolar cell (100) and the lower bipolar cell (100) to be electrically connected in series. Alternatively, if necessary, a conductive connector (not shown) may be added between the two bipolar cells (100) stacked adjacent to each other vertically. In this way, a plurality of bipolar cells (100) stacked along the first direction (Z-axis direction) can be electrically connected in series with each other to form a sub-stack (CSa, CSb) having a high voltage.

[0098] Referring again to FIGS. 2 to 4, a plurality of sub-stacks (CSa, CSb) can be electrically connected to a busbar assembly (500, 600) through current collection plates (210, 220, 230).

[0099] In one embodiment, the busbar assembly (500, 600) may include a conductive inner busbar (e.g., 510 in FIG. 7, 610 in FIG. 9) electrically connected to the bipolar cell (100), a busbar frame (e.g., 520 in FIG. 7, 620 in FIG. 9) supporting the inner busbar (510, 610), and a plurality of terminals (530, 630) connected to the inner busbar (510, 610) and exposed to the outside of the bipolar cell (100).

[0100] In one embodiment, the bipolar battery (10) may include a plurality of busbar assemblies (500, 600), each comprising a first busbar assembly (500) and a second busbar assembly (600). For example, referring to FIG. 3, the first busbar assembly (500) may be positioned to face one side of the cell stack (CS) in a second direction (e.g., X-axis direction) perpendicular to the first direction (Z-axis direction), and the second busbar assembly (600) may be positioned to face the other side of the cell stack (CS) in a second direction (X-axis direction). That is, the first busbar assembly (500) and the second busbar assembly (600) may be positioned spaced apart in the second direction (X-axis direction) with the cell stack (CS) in between. In the following description, unless otherwise specifically stated, 'second direction' may mean the direction in which the busbar assembly (500, 600) and the cell stack (CS) face each other.

[0101] The first busbar assembly (500) may include a pair of first terminals (530) electrically connected to the cell stack (CS). The pair of first terminals (530) may be spaced apart along a third direction (e.g., Y-axis direction) perpendicular to both the first direction (Z-axis direction) and the second direction (X-axis direction) on one side of the cell stack (CS), and may be positioned so as to be exposed to the outside of the bipolar cell (10).

[0102] A pair of first terminals (530) may consist of two terminals having different electrical polarities. For example, one of the pair of first terminals (530) may be electrically connected to a current collector plate having a first polarity (e.g., positive), and the other of the pair of first terminals (530) may be electrically connected to a current collector plate having a second polarity (e.g., negative). Accordingly, the pair of first terminals (530) may include both a positive terminal and a negative terminal. In the following description, the terminal having the first polarity among the pair of first terminals (530) is referred to as the first-1 terminal, and the terminal having the second polarity is referred to as the first-2 terminal.

[0103] The second busbar assembly (600) may include a pair of second terminals (630) electrically connected to the cell stack (CS). The pair of second terminals (630) may be spaced apart along a third direction (Y-axis direction) perpendicular to both the first direction (Z-axis direction) and the second direction (X-axis direction) on the opposite side of the pair of first terminals (530) relative to the cell stack (CS), and may be positioned so as to be exposed to the outside of the bipolar cell (10).

[0104] A pair of second terminals (630) may consist of two terminals having different electrical polarities. For example, one of the pair of second terminals (630) may be electrically connected to a current collector plate having a first polarity (e.g., positive), and the other of the pair of second terminals (630) may be electrically connected to a current collector plate having a second polarity (e.g., negative). Accordingly, the pair of second terminals (630) may include both a positive terminal and a negative terminal. In the following description, the terminal having the first polarity among the pair of second terminals (630) is referred to as the second-1 terminal, and the terminal having the second polarity is referred to as the second-2 terminal. In this case, the second-1 terminal may have the same polarity as the first-1 terminal.

[0105] In one embodiment, for a pair of first terminals (530) and a pair of second terminals (630), the direction in which the terminals having a first polarity and the terminals having a second polarity are arranged may be the same. For example, the first-1 terminal and the first-2 terminal may be arranged sequentially along the +Y-axis direction, and the second-1 terminal and the second-2 terminal may also be arranged sequentially along the +Y-axis direction.

[0106] In one embodiment, a pair of first terminals (530) and a pair of second terminals (630) may be arranged so as to be rotationally symmetric with respect to the cell stack (CS). For example, referring to FIG. 2, when a central axis (CL1) extending from the center of the second direction (X-axis direction) and the third direction (Y-axis direction) to the first direction (Z-axis direction) is set in the bipolar battery (10), a pair of first terminals (530) and a pair of second terminals (630) may be arranged so as to be rotationally symmetric with respect to the central axis (CL1). That is, when the bipolar battery (10) is rotated 180 degrees with respect to the central axis (CL1), a pair of second terminals (630) are placed at the position of a pair of first terminals (530) before the bipolar battery (10) is rotated. According to the arrangement structure of such terminals (530, 630), when interconnecting multiple bipolar batteries (10), each bipolar battery (10) can be appropriately rotated to easily implement a series connection structure or a parallel connection structure.

[0107] Alternatively, in one embodiment, a pair of first terminals (530) and a pair of second terminals (630) may be arranged so as to be mirror-symmetric with respect to the cell stack (CS). For example, referring to FIG. 2, when setting a center line (CL2) extending from the center of the second direction (X-axis direction) to the third direction (Y-axis direction) in a bipolar cell (10), a pair of first terminals (530) and a pair of second terminals (630) may be arranged so as to be mirror-symmetric with respect to the center line (CL2). According to such an arrangement structure of terminals (530, 630), the terminal connection structure between adjacent bipolar cells (10) can be simplified when interconnecting a plurality of bipolar cells (10).

[0108] The detailed configuration of the busbar assembly (500, 600) and the electrical connection structure between the plurality of bipolar batteries (10) will be described later with reference to FIGS. 7 to 9.

[0109] Referring further to FIG. 2 and FIG. 3, the bipolar cell (10) is positioned on the outer edge of the busbar assembly (500, 600) and may further include a plurality of end covers (400). The end covers (400) may form at least one side of the bipolar cell (10). The end covers (400) may be positioned on the side of the cell stack (CS) where the busbar assembly (500, 600) is installed, thereby covering and protecting the cell stack (CS) and the busbar assembly (500, 600).

[0110] In one embodiment, a plurality of end covers (400) may include a first end cover (410) disposed on one side of the cell stack (CS) and a second end cover (420) disposed on the other side of the cell stack (CS). The first end cover (410) may be disposed facing the cell stack (CS) in a second direction (X-axis direction) with the first busbar assembly (500) in between, and the second end cover (420) may be disposed facing the cell stack (CS) in a second direction (X-axis direction) with the second busbar assembly (600) in between.

[0111] In one embodiment, the first end cover (410) can cover the cell stack (CS) and the first busbar assembly (500) on one side of the cell stack (CS). The second end cover (420) can cover the cell stack (CS) and the second busbar assembly (600) on the other side of the cell stack (CS).

[0112] The end cover (400) may be formed of a material having sufficient rigidity to reliably protect the cell stack (CS). For example, the end cover (400) may include a metal such as aluminum or a polymer resin material having a certain rigidity.

[0113] In one embodiment, the end cover (400) can be used as a coupling structure for coupling a plurality of bipolar batteries (10) together. A detailed description thereof will be given later with reference to FIGS. 11 to 14.

[0114] Referring further to FIGS. 2 and FIGS. 3, the bipolar battery (10) may further include an insulating cover (700) disposed between the end cover (400) and the busbar assembly (500, 600). The insulating cover (700) may include an insulating material to prevent components inside the bipolar battery (10), such as a cell stack (CS), a busbar assembly (500, 600), a terminal (530, 630), etc., from being electrically short-circuited with the end cover (400).

[0115] As shown in FIG. 3, the insulating cover (700) may be provided with a structure corresponding to the shape of the busbar assembly (500, 600). However, the specific structure of the insulating cover (700) is not limited to that shown in the drawing, and any structure that can prevent the end cover (400) and the cell stack (CS), or the end cover (400) and the busbar assembly (500, 600) from being electrically short-circuited to each other may be applied without limitation.

[0116] In one embodiment, the bipolar cell (10) may further include a pair of pressure plates (300) covering the upper and lower surfaces of a cell stack (CS). For example, the pair of pressure plates (300) may include a first pressure plate (310) and a second pressure plate (320) spaced apart in a first direction (Z-axis direction) with the cell stack (CS) in between. For example, the first pressure plate (310) may be positioned to face the lower surface of the cell stack (CS) in the first direction (Z-axis direction) to cover the lower surface of the cell stack (CS). Additionally, the second pressure plate (320) may be positioned to face the upper surface of the cell stack (CS) in the first direction (Z-axis direction) to cover the upper surface of the cell stack (CS).

[0117] The first pressure plate (310) and the second pressure plate (320) can be combined with the end cover (400). The first pressure plate (310) is combined with the lower part of the first end cover (410) and the lower part of the second end cover (420), and the second pressure plate (320) can be combined with the upper part of the first end cover (410) and the upper part of the second end cover (420).

[0118] The first pressure plate (310) and the second pressure plate (320) can apply a predetermined pressure to the cell stack (CS). For example, the first pressure plate (310) and the second pressure plate (320) can be each coupled to the end cover (400) so that the spacing in the first direction (Z-axis direction) can be fixed, and accordingly, they can be configured to withstand the expansion pressure generated during the charging and discharging process of the cell stack (CS) and apply surface pressure to the cell stack (CS).

[0119] The first pressure plate (310) and the second pressure plate (320) may be formed of a material having sufficient rigidity to protect the cell stack (CS). For example, the first pressure plate (310) and the second pressure plate (320) may include a metal such as aluminum or a polymer resin material having a certain rigidity.

[0120] In one embodiment, the bipolar cell (10) may further include a compression pad disposed between the cell stack (CS) and the pressure plate (300). For example, the compression pad may perform the function of preventing the cell stack (CS) and the pressure plate (300) from being electrically short-circuited to each other, while uniformly distributing the pressure applied from the pressure plate (300) to the upper or lower surface of the cell stack (CS). However, in various embodiments of the present disclosure, the compression pad may be omitted.

[0121] Hereinafter, with reference to FIGS. 7 to 9, the electrical connection structure of the bipolar battery (10) according to the embodiments will be described in detail.

[0122] FIG. 7 is a perspective view of a first busbar assembly (500) of a bipolar battery (10) according to one embodiment.

[0123] FIG. 8 is an exemplary exploded perspective view of a first busbar assembly (500) according to one embodiment.

[0124] FIG. 9 is a perspective view of a second busbar assembly (600) of a bipolar battery (10) according to one embodiment.

[0125] Since the bipolar battery (10) described in FIGS. 7 to 9 includes all the features of the bipolar battery (10) described in FIGS. 1 to 6, descriptions that overlap with FIGS. 1 to 6 may be omitted.

[0126] Meanwhile, FIGS. 7 and 9 illustrate a cell stack (CS) and a busbar assembly (500, 600) of a bipolar battery (10), and it should be noted that a pressure plate (e.g., 300 in FIGS. 2 and 3) covering the upper and lower surfaces of the cell stack (CS) has been omitted.

[0127] In one embodiment, the bipolar cell (10) may include a first busbar assembly (500) disposed on one side of the cell stack (CS) and a second busbar assembly (600) disposed on the other side of the cell stack (CS).

[0128] In one embodiment, the first busbar assembly (500) may include a plurality of conductive inner busbars (510) electrically connected to current collection plates (210, 220, 230) of a cell stack (CS), a busbar frame (520) supporting the plurality of inner busbars (510), and a pair of first terminals (530) electrically connected to the inner busbars (510) and exposed to the outside of the end cover (400).

[0129] In one embodiment, the second busbar assembly (600) may include a conductive inner busbar (610) electrically connected to a current collection plate (210, 220, 230) of a cell stack (CS), a busbar frame (620) supporting the inner busbar (610), and a pair of second terminals (630) electrically connected to the inner busbar (610) and exposed to the outside of the end cover (400).

[0130] In any one busbar assembly (500, 600), the internal busbars (510, 610) may be provided in multiple numbers. For example, referring to FIGS. 7 and FIGS. 9 together, the first busbar assembly (500) may include a first internal busbar (511) and a second internal busbar (512) that are electrically connected to current collection plates (210, 220, 230). Alternatively, the second busbar assembly (600) may include a third internal busbar (611) and a fourth internal busbar (612) that are electrically connected to current collection plates (210, 220, 230).

[0131] The inner busbar (510, 610) can be electrically connected by contacting the connecting plate (211, 221, 231) of the current collection plate (210, 220, 230). For example, referring to FIG. 7, the first current collection plate (210) may have a conductive connecting plate (211) that penetrates a slit formed in the busbar frame (520, 620), and the first inner busbar (511) may be electrically connected to the first current collection plate (210) by being coupled to the connecting plate (211) of the first current collection plate (210).

[0132] In one embodiment, the connecting plate (211, 221, 231) of the current collection plate (210, 220, 230) may be formed by bending a portion of the current collection plate (210, 220, 230) so that it penetrates the busbar frame (520, 620). For example, referring to FIG. 7, the connecting plate (211) of the first current collection plate (210) may be bent so that a portion of the first current collection plate (210) penetrates the first busbar frame (520) and is in close contact with the first inner busbar (511) placed on the first busbar frame (520).

[0133] Various welding methods, including ultrasonic welding or laser welding, can be applied to the connection plate (211, 221, 231) of the internal busbar (510, 610) and the current collection plate (210, 220, 230). However, in addition to welding methods, any connection method can be applied without limitation as long as the two members can be electrically connected.

[0134] The inner busbar (510, 610) can be electrically connected to the bipolar cell (100) while fixed to the busbar frame (520, 620). For example, referring to FIGS. 7 and FIGS. 8 together, one side of the busbar frame (520, 620) may be positioned to face the bipolar cell (100), and a receiving groove may be formed on the other side of the busbar frame (520, 620) opposite to the one side, into which the inner busbar (510, 610) can be seated. The inner busbar (510, 610) can be received in this receiving groove and fixed while electrically connected to the bipolar cell (100). The busbar frame (520, 620) may include a material having insulating properties and excellent mechanical strength (e.g., a polymer resin material) so as to stably support the inner busbar (510, 610) even under external shock or vibration conditions.

[0135] The busbar frame (520, 620) can be combined with the pressure plate (300). For example, referring to FIG. 8, the busbar frame (520, 620) may include one or more connecting pins (521) protruding in a first direction (Z-axis direction) or the opposite direction. These connecting pins (521) may be inserted into the pressure plate (300). However, the method of combining the busbar frame (520, 620) and the pressure plate (300) is not limited to that described above.

[0136] A terminal (530, 630) may be formed in each internal busbar (510, 610). For example, referring to FIGS. 7 through 9, a terminal (530, 630) may be formed in each of the first to fourth internal busbars (511, 512, 611, 612). A connecting hole (530a, 630a) may be formed in the terminal (530, 630). This connecting hole (530a, 630a) can be utilized as a fixing structure for connecting one terminal (e.g., 530) and another terminal (e.g., 630) to each other.

[0137] Referring together to FIGS. 7 to 9, in one embodiment, the first busbar assembly (500) may be configured to electrically connect the first sub-stack (CSa) and the second sub-stack (CSb) in parallel. For example, a plurality of bipolar cells (100) constituting the first sub-stack (CSa) may all be stacked and connected in series such that a first electrode plate (150) having a first polarity (e.g., positive) faces upward (+Z-axis direction). Additionally, a plurality of bipolar cells (100) constituting the second sub-stack (CSb) may all be stacked and connected in series such that a second electrode plate (160) having a second polarity (e.g., negative) faces upward (+Z-axis direction). In such a cell stack (CS) stacked structure, the first current collector plate (210) can be electrically connected to the second electrode plate (160) at the bottom of the first sub-stack (CSa), and thus may have a second polarity. Additionally, the second current collector plate (220) can be electrically connected to the second electrode plate (160) at the top of the second sub-stack (CSb), and thus may have a second polarity. Additionally, the third current collector plate (230) can be electrically connected to the first electrode plate (150) at the top of the first sub-stack (CSa) and the first electrode plate (150) at the bottom of the second sub-stack (CSb), and thus may have a first polarity.

[0138] The first internal busbar (511) and the second internal busbar (512) can be electrically connected to current collection plates having different electrical polarities. For example, referring to FIG. 7, the first internal busbar (511) can be electrically connected to the first current collection plate (210) and the second current collection plate (220) having the same electrical polarity, and the second internal busbar (512) can be electrically connected to the third current collection plate (230) having an electrical polarity opposite to that of the first current collection plate (210). In this case, the first internal busbar (511) may have a plurality of connecting portions (511a) formed therein so as to be coupled to the connecting plate (211) of the first current collection plate (210) and the connecting plate (221) of the second current collection plate (220), respectively. For example, referring to FIGS. 7 and FIGS. 8 together, the first internal busbar (511) may include a plurality of first connecting portions (511a) that contact the connecting plate (211) of the first current collection plate (210) and the connecting plate (221) of the second current collection plate (220). Meanwhile, the second internal busbar (512) may have a second connecting portion (512a) formed that connects to the connecting plate (231) of the third current collection plate (230).

[0139] In this way, as the first internal busbar (511) and the second internal busbar (512) are connected to current collection plates (210, 220, 230) having different electrical polarities, the first internal busbar (511) and the second internal busbar (512) have opposite electrical polarities, and the first terminals (530) connected to the first internal busbar (511) and the second internal busbar (512), respectively, may also have opposite electrical polarities. Accordingly, in any bipolar battery (10), the first sub-stack (CSa) and the second sub-stack (CSb) may be connected in parallel to have a pair of first terminals (530) having opposite electrical polarities.

[0140] In one embodiment, the connecting plate (231) of the third current collection plate (230) may be positioned between the connecting plate (211) of the first current collection plate (210) and the connecting plate (221) of the second current collection plate (220), and correspondingly, the second connecting portion (512a) may be positioned between a plurality of first connecting portions (511a). In this case, the first connecting portion (511a) and the second connecting portion (512a) may be positioned spaced apart from each other along the first direction (Z-axis direction).

[0141] In one embodiment, the first busbar assembly (500) may further include a sensing unit (540) electrically connected to the cell stack (CS). The sensing unit (540) may be configured to detect the magnitude of the voltage or temperature of the cell stack (CS) and transmit information thereto to an external circuit (e.g., a control module of the battery device (1 in FIG. 1).

[0142] In one embodiment, the second busbar assembly (600) may be configured to electrically connect the first substack (CSa) and the second substack (CSb) to each other in parallel, just like the first busbar assembly (500). For example, referring to FIG. 9, the third internal busbar (611) may be electrically connected to the first current collector plate (210) and the second current collector plate (220) having the same electrical polarity, and the fourth internal busbar (612) may be electrically connected to the third current collector plate (230) having an electrical polarity opposite to that of the first current collector plate (210). According to this connection structure, a structure in which two sub-cell stacks (CS) are connected in parallel can be implemented, wherein a pair of first terminals (530) having opposite electrical polarities are arranged along one edge of the bipolar cell (10), and a pair of second terminals (630) having opposite electrical polarities are arranged along the other edge of the bipolar cell (10).

[0143] Meanwhile, in various embodiments of the present disclosure, a single cell stack (CS) may include three or more sub-stacks. Hereinafter, with reference to FIG. 10, a cell stack (CS) including three or more sub-stacks (CSa, CSb, CSc) will be described. FIG. 10 is an exploded perspective view of a cell stack (CS) included in a bipolar cell (e.g., 10 of FIG. 1) according to various embodiments.

[0144] In various embodiments of the present disclosure, a cell stack (CS) may include three or more sub-stacks (CSa, CSb, CSc) that are electrically connected to each other. For example, referring to FIG. 10, the cell stack (CS) may include a first sub-stack (CSa), a second sub-stack (CSb), and a third sub-stack (CSc) that are stacked along a first direction (Z-axis direction).

[0145] The first sub-stack (CSa), the second sub-stack (CSb), and the third sub-stack (CSc) may each include a plurality of bipolar cells (100). For example, a plurality of bipolar cells (100) included in any one sub-stack (CSa, CSb, CSc) may be stacked along a first direction (Z-axis direction) and electrically connected to one another. Regarding the electrical connection of the plurality of bipolar cells (100), reference can be made to the previously described content through FIGS. 1 to 9.

[0146] A plurality of sub-stacks (CSa, CSb, CSc) included in a cell stack (CS) can be electrically connected to each other through a plurality of current collection plates (210, 220, 230, 240). For example, referring to FIG. 10, the cell stack (CS) may include a plurality of sub-stacks (CSa, CSb, CSc) and a plurality of current collection plates (210, 220, 230, 240) that are alternately stacked along a first direction (Z-axis direction). Each sub-stack (CSa, CSb, CSc) can be electrically connected to another sub-stack (CSa, CSb, CSc) through a plurality of current collection plates (210, 220, 230, 240) arranged facing each other on its upper and lower surfaces.

[0147] Referring to FIG. 10, the first current collector plate (210) and the third current collector plate (230) are each positioned to face the lower and upper surfaces of the first sub-stack (CSa) and can be electrically connected to the first sub-stack (CSa). Additionally, the third current collector plate (230) and the second current collector plate (220) are each positioned to face the lower and upper surfaces of the second sub-stack (CSb) and can be electrically connected to the second sub-stack (CSb). Additionally, the second current collector plate (220) and the fourth current collector plate (240) are each positioned to face the lower and upper surfaces of the third sub-stack (CSc) and can be electrically connected to the third sub-stack (CSc).

[0148] A busbar assembly (e.g., 500, 600 in FIG. 3) can be electrically connected to a first current collector plate (210), a second current collector plate (220), and a third current collector plate (230), and accordingly, a plurality of sub-stacks (CSa, CSb, CSc) can be electrically connected to each other through a plurality of current collector plates (210, 220, 230, 240) and a busbar assembly (500, 600).

[0149] In various embodiments of the present disclosure, three or more substacks (CSa, CSb, CSc) may be connected to each other in series or in parallel. For example, in the cell stack (CS) illustrated in FIG. 10, the first current collector plate (210) and the second current collector plate (220) may be arranged to have a first polarity, and the third current collector plate (230) and the fourth current collector plate (240) may be arranged to have a second polarity opposite to the first polarity. Of a pair of terminals (e.g., 530 in FIG. 3) included in the first busbar assembly (e.g., 500 in FIG. 3), one terminal (530) may be connected to the first current collector plate (210) and the second current collector plate (220), and the other terminal (530) may be connected to the third current collector plate (230) and the fourth current collector plate (240). Additionally, a pair of terminals (e.g., 630 in FIG. 3) included in the second busbar assembly (e.g., 600 in FIG. 3) can also be connected in the same manner. According to this connection structure, the first sub-stack (CSa), the second sub-stack (CSb), and the third sub-stack (CSc) can be electrically connected to other components outside the bipolar battery (10) while connected in parallel with each other. However, unlike the above, any one of the first sub-stack (CSa), the second sub-stack (CSb), and the third sub-stack (CSc) may be arranged to be connected in series with the other.

[0150] Meanwhile, other technical features regarding the first sub-stack (CSa), the second sub-stack (CSb), the first current collector plate (210), the second current collector plate (220), and the third current collector plate (230) may be applied with reference to FIGS. 1 through 9, to the extent that they do not contradict the description of FIG. 10.

[0151] In FIG. 10, three substacks (CSa, CSb, CSc) are shown, but in various embodiments of the present disclosure, the cell stack (CS) may include four or more substacks.

[0152] In various embodiments of the present disclosure, another bipolar cell (10) can be connected in series or parallel to both sides of the bipolar cell (10) through a pair of terminals (530, 630) respectively disposed on both sides of the bipolar cell (10). Accordingly, various types of power circuits can be implemented using the same bipolar cell (10).

[0153] Hereinafter, with reference to FIGS. 11 to 14, the connection structure between a plurality of bipolar batteries (10) will be described in detail.

[0154] FIG. 11 is a reference diagram for explaining the connection between two bipolar batteries (10) according to one embodiment.

[0155] FIG. 12 is a part of a side view of a bipolar battery (10) according to one embodiment.

[0156] FIG. 13 is a part of a side view of a bipolar battery (10) according to one embodiment.

[0157] FIG. 14 is a part of a combined cross-sectional view of two bipolar batteries (10) according to one embodiment.

[0158] Since the bipolar battery (10) described in FIGS. 11 to 14 includes all the features of the bipolar battery (10) described in FIGS. 1 to 10, descriptions that overlap with FIGS. 1 to 10 may be omitted.

[0159] FIG. 11 illustrates two bipolar batteries (10) being electrically connected to each other, and it should be noted that the end cover (e.g., 400 in FIG. 3) in the drawing has been omitted.

[0160] In one embodiment, a plurality of bipolar batteries (10) can be electrically connected to each other through connections between a plurality of terminals (530, 630). For example, in a first bipolar battery (10a) and a second bipolar battery (10b) arranged facing each other in a second direction (X-axis direction), the first bipolar battery (10a) and the second bipolar battery (10b) can be electrically connected to each other as a pair of second terminals (630) of the first bipolar battery (10a) and a pair of first terminals (530) of the second bipolar battery (10b) are electrically connected.

[0161] In one embodiment, a plurality of bipolar batteries (10) may be electrically connected by their terminals (530, 630) coming into direct contact with each other. For example, referring to FIG. 11, a pair of second terminals (630) of a first bipolar battery (10a) and a pair of first terminals (530) of a second bipolar battery (10b) may come into contact with each other in a first direction (Z-axis direction) and be joined. In this case, the connection hole (530a) of the first terminal (530) and the connection hole (630a) of the second terminal (630) may overlap in the first direction (Z-axis direction), and a fastening bolt (not shown) may be inserted into both connection holes (530a, 630a) to secure the first terminal (530) and the second terminal (630) to each other. However, the combined structure of the first terminal (530) and the second terminal (630) is not limited to what has been described above. For example, the first terminal (530) and the second terminal (630) may be welded together in a state of direct contact.

[0162] In this way, multiple bipolar cells (10) are connected in a manner where multiple terminals (530, 630) come into direct contact, thereby eliminating the need for a separate conductive connecting member that was previously used to connect conventional battery modules. Accordingly, a simple yet stable electrical connection structure can be implemented, and the electrical resistance at the connection point of the multiple terminals (530, 630) can be reduced. In particular, even if individual bipolar cells (100) are implemented at high voltage, a safe and efficient battery device (1) can be implemented through the connection structure that minimizes electrical resistance as described above. Furthermore, since the terminals (530, 630) are directly connected to each other, additional conductive connecting members can be eliminated, thereby reducing manufacturing costs.

[0163] To implement such a connection structure, the first terminal (530) and the second terminal (630) may be arranged to have different heights relative to a reference position. Hereinafter, with reference to FIGS. 12 and FIGS. 13 together, the coupling structure through the end cover (400) and the arrangement positions of the first terminal (530) and the second terminal (630) in the bipolar battery (10) will be explained.

[0164] First, referring to FIG. 12, a first end cover (410) may be disposed on one side of a cell stack (CS) included in a bipolar battery (10). The first end cover (410) may include a first protrusion (411) that protrudes outward from the first end cover (410) in a direction parallel to the second direction (X-axis direction), which is the direction in which the first end cover (410) and the cell stack (CS) face each other. A first step portion (411a) may be formed on one side of the first protrusion (411), and this first step portion (411a) may be utilized as a coupling portion with a second end cover (420) of an adjacent bipolar battery (10).

[0165] In one embodiment, the first terminal (530) may protrude further in the direction toward the first end cover (410) from the cell stack (CS) than the outer surface of the first end cover (410). For example, referring to FIG. 12, the first protrusion (411) may form the outermost surface of the first end cover (410), and the end of the first terminal (530) may protrude further than the first protrusion (411). As such, as the first terminal (530) protrudes further than the outermost surface of the first end cover (410), it can easily come into contact with the terminals (530, 630) of the adjacent other bipolar cell (10).

[0166] Referring to FIG. 13, a second end cover (420) may be disposed on the other side of a cell stack (CS) included in a bipolar battery (10). The second end cover (420) may include a second protrusion (421) that protrudes outward from the second end cover (420) in a direction parallel to the second direction (X-axis direction). A second stepped portion (421a) may be formed on one side of the second protrusion (421), and this second stepped portion (421a) may be utilized as a coupling portion with the first end cover (410) of an adjacent bipolar battery (10).

[0167] However, the structure of the first end cover (410) and the second end cover (420) described above is merely an example, and in various embodiments, the first end cover (410) and the second end cover (420) may not have protrusions (411, 421) formed therein. For example, in various embodiments, any two bipolar batteries (10) may be coupled to each other with their respective first end covers (410) facing each other in a second direction (X-axis direction), and in this case, the first terminals (530) of each bipolar battery (10) may be electrically connected by touching each other.

[0168] In one embodiment, the second terminal (630) may protrude further in the direction toward the second end cover (420) from the cell stack (CS) than the outer surface of the second end cover (420). For example, referring to FIG. 13, the second protrusion (421) may form the outermost surface of the second end cover (420), and the end of the second terminal (630) may protrude further than the second protrusion (421). As such, as the second terminal (630) protrudes further than the outermost surface of the second end cover (420), it can easily come into contact with the terminals (530, 630) of the adjacent other bipolar cell (10).

[0169] Referring together to FIGS. 12 to 14, in one embodiment, the first terminal (530) may be spaced apart by a first gap (d1) in a first direction (Z-axis direction) from the first stepped portion (411a) of the first end cover (410), and the second terminal (630) may be spaced apart by a second gap (d2) in a first direction (Z-axis direction) from the second stepped portion (421a) of the second end cover (420). Here, the first gap (d1) may be smaller than the second gap (d2), and accordingly, a connection structure such as that of FIG. 14 may be formed. For example, the first bipolar battery (10a) and the second bipolar battery (10b) can be combined such that the second step portion (421a) of the second end cover (420) of the first bipolar battery (10a) and the first step portion (411a) of the first end cover (410) of the second bipolar battery (10b) are in contact with each other, and the first terminal (530) is spaced apart from the first step portion (411a) by a first gap (d1), and the second terminal (630) is spaced apart from the second step portion (421a) by a second gap (d2) which is larger than the first gap (d1), so that the first terminal (530) and the second terminal (630) can be combined so as to overlap in a first direction (Z-axis direction) without mutual interference.

[0170] In one embodiment, two adjacent bipolar batteries (10) can be fixed to each other through a fastening member (70) that is coupled to each end cover (400). For example, referring to FIG. 14, a first bipolar battery (10a) and a second bipolar battery (10b) can be coupled such that the second stepped portion (421a) of the first bipolar battery (10a) and the first stepped portion (411a) of the second bipolar battery (10b) are in contact with each other, and at this time, a fastening member (70) that penetrates either the first stepped portion (411a) or the second stepped portion (421a) and is coupled to the other can fix the two bipolar batteries (10) to each other. In this way, not only can a robust coupling structure be formed by interlocking the end covers (400) with each other, but a cross beam between each bipolar cell (10) in the housing (20 in FIG. 1) is not required, thereby enabling the realization of a simple yet robust battery device (1) structure. However, the coupling structure of two adjacent bipolar cells (10) is not limited to what has been described above; for example, when coupling two adjacent bipolar cells (10), a method of fusion, welding, or snap-fitting between the end covers (400) may be applied.

[0171] In various embodiments, the electrical connection structure between bipolar cells (10) can be implemented in various modified ways. For example, a first bipolar cell (10a) and a second bipolar cell (10b) may be electrically connected in parallel by contacting terminals having the same electrical polarity. Alternatively, a first bipolar cell (10a) and a second bipolar cell (10b) may be electrically connected in series by contacting terminals having opposite electrical polarities. In the case of such a series connection, it can be implemented by changing the arrangement direction of one of the bipolar cells (10) compared to a parallel connection. That is, according to the bipolar cell (10) and the battery device (1) including the same according to the present disclosure, a series connection structure or a parallel connection structure of a plurality of bipolar cells (10) can be simply implemented by changing the connection direction of the bipolar cells (10).

[0172] Meanwhile, the battery device (1) according to various embodiments of the present disclosure can be used as a power source for various electronic devices, and the battery device may be, for example, a laptop computer, netbook, tablet PC, mobile phone, MP3, wearable electronic device, power tool, electric vehicle (EV), hybrid electric vehicle (HEV), plug-in hybrid electric vehicle (PHEV), electric bicycle (E-bike), electric scooter (E-scooter), electric golf cart, or energy storage system (ESS), but is not limited to these.

[0173] Although various embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and it will be obvious to those with average knowledge in the art that various modifications and variations are possible within the scope of the technical concept of the present invention as described in the claims. Furthermore, the above-described embodiments may be implemented by deleting some components, and each embodiment may be implemented in combination with one another.

Claims

1. A cell stack comprising a plurality of bipolar cells stacked along a first direction; A first busbar assembly disposed on one side of the cell stack; and It includes a second busbar assembly disposed on the other side of the cell stack, and The first busbar assembly includes a pair of first terminals electrically connected to the cell stack, and The above second busbar assembly comprises a pair of second terminals electrically connected to the cell stack, a bipolar cell.

2. In Paragraph 1, A pressure plate positioned facing the cell stack and the first direction; A first end cover coupled to the above-mentioned pressure plate and covering the cell stack and the first busbar assembly; and A bipolar battery further comprising a second end cover coupled to the above-mentioned pressure plate and covering the cell stack and the second busbar assembly.

3. In Paragraph 2, The above pair of first terminals protrudes further than the outer surface of the first end cover, and A bipolar battery in which the above pair of second terminals protrude further than the outer surface of the above second end cover.

4. In Paragraph 2, The cell stack and the first busbar assembly are arranged to face each other in a second direction perpendicular to the first direction, and A bipolar battery comprising a pair of first terminals, wherein the first terminals are spaced apart from each other in a third direction perpendicular to both the first direction and the second direction.

5. In Paragraph 1, The above cell stack is, A bipolar battery comprising a first current collection plate and a second current collection plate spaced apart in the first direction with at least one of the plurality of bipolar cells in between.

6. In Paragraph 5, The first busbar assembly or the second busbar assembly is, A bipolar battery further comprising a plurality of internal busbars electrically connected to the first current collection plate and the second current collection plate, and a busbar frame supporting the plurality of internal busbars.

7. In Paragraph 6, It further includes a pressure plate positioned facing the cell stack and the first direction, The above busbar frame is a bipolar battery coupled with the above pressure plate.

8. In Paragraph 6, The above plurality of internal busbars are seated on one surface of the busbar frame, and The first current collector plate or the second current collector plate is, A bipolar battery comprising a connecting plate that penetrates from the opposite side of the busbar frame toward the one side and is connected to one of the plurality of internal busbars.

9. In Paragraph 5, It further includes a third current collector plate disposed between the first current collector plate and the second current collector plate, and The first current collector plate and the second current collector plate have the same electrical polarity, and A bipolar battery in which the first current collector plate and the third current collector plate have electrically opposite polarities.

10. In Paragraph 9, The above-mentioned first busbar assembly is, A first internal busbar electrically connected to the first current collection plate and the second current collection plate; and It further includes a second internal busbar electrically connected to the third current collection plate, One of the above pair of first terminals is electrically connected to the first internal busbar, and A bipolar battery, the other of the pair of first terminals is electrically connected to the second internal busbar.

11. In Paragraph 1, A bipolar cell in which the above pair of first terminals and the above pair of second terminals are arranged so as to be rotationally symmetric with respect to the central axis of the bipolar cell.

12. In Paragraph 1, The above cell stack is, A first substack stacked such that at least two of the plurality of bipolar cells are connected in series with each other; and It includes a second sub-stack in which at least two of the plurality of bipolar cells are stacked to be connected in series with each other, A bipolar battery in which the first sub-stack and the second sub-stack are connected in parallel.

13. In Paragraph 12, The above cell stack is, It further includes a third sub-stack in which at least two of the plurality of bipolar cells are stacked to be connected in series with each other. The first sub-stack, the second sub-stack, and the third sub-stack are stacked along one direction, The above third sub-stack is a bipolar cell connected in parallel with the above first sub-stack and the above second sub-stack.

14. A first bipolar cell and a second bipolar cell arranged facing each other, and The first bipolar battery and the second bipolar battery are each bipolar batteries according to claim 1, and A battery device in which the pair of first terminals of the first bipolar battery are electrically connected to the pair of second terminals of the second bipolar battery.

15. In Paragraph 14, A battery device in which at least a portion of the pair of first terminals of the first bipolar cell overlaps with the pair of second terminals of the second bipolar cell in the stacking direction of the plurality of bipolar cells.

16. In Paragraph 15, A battery device in which the first bipolar cell and the second bipolar cell are connected in parallel.

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