Battery device

Abstract

A battery device according to embodiments comprises: a plurality of bipolar batteries including a cell stack having a plurality of bipolar cells stacked along a first direction, at least one pressing plate disposed to face the cell stack in the first direction, and at least one end cover coupled to the at least one pressing plate and covering the cell stack in a second direction intersecting the first direction; and a housing accommodating the plurality of bipolar batteries, wherein the plurality of bipolar batteries may include a first bipolar battery and a second bipolar battery disposed along the second direction inside the housing and electrically connected to each other.

Description

battery device

[0001] The present invention relates to a battery device comprising a bipolar cell.

[0002] This application claims the benefit of priority based on Korean Patent Application No. 2025-0002327 dated January 7, 2025, and all contents disclosed in the document of said Korean patent application 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 power storage devices, a new secondary battery structure capable of stably providing high-voltage power is required, and an efficient connection structure and arrangement structure between multiple secondary batteries having such a new structure are required.

[0005] The present invention aims to provide a battery device comprising a bipolar cell capable of implementing high voltage.

[0006] In addition, the present invention aims to provide a battery device having high structural stability and cooling efficiency.

[0007] To achieve the above objective, embodiments of the present invention provide a battery device comprising: a plurality of bipolar cells including a plurality of bipolar cells, each comprising a plurality of bipolar cells stacked along a first direction, at least one pressure plate disposed facing the cell stack in the first direction, and at least one end cover coupled to the at least one pressure plate and covering the cell stack in a second direction intersecting the first direction; and a housing for accommodating the plurality of bipolar cells, wherein the plurality of bipolar cells includes a first bipolar cell and a second bipolar cell disposed along the second direction inside the housing and electrically connected to each other.

[0008] In the embodiments, the end cover of the first bipolar cell can be combined with the end cover of the second bipolar cell.

[0009] In the embodiments, the end cover of the second bipolar cell includes a first protrusion protruding in a direction toward the first bipolar cell, and the end cover of the first bipolar cell includes a second protrusion protruding in a direction toward the second bipolar cell, and at least a portion of the first protrusion may overlap with the second protrusion in a first direction.

[0010] In the embodiments, the first protrusion and the second protrusion may be in contact with each other in the first direction.

[0011] In the embodiments, the battery device may further include a fastening member that penetrates either of the first protrusion and the second protrusion and is coupled to the other.

[0012] In the embodiments, the battery device may further include a cooling member extending along a second direction on one side of the first bipolar cell or on one side of the second bipolar cell.

[0013] In the embodiments, the cooling member may be positioned facing the side of the first bipolar cell and the side of the second bipolar cell in a third direction that intersects both the first direction and the second direction.

[0014] In the embodiments, a cell stack may be exposed on the side facing the cooling member of the first bipolar cell and on the side facing the cooling member of the second bipolar cell.

[0015] In the embodiments, the cooling member may include a cooling plate having a refrigerant flow path formed therein through which a refrigerant flows; and a heat transfer member disposed between at least one of a first bipolar cell or a second bipolar cell and the cooling plate.

[0016] In the embodiments, the heat transfer member may be in contact with a bipolar cell included in at least one of the first bipolar cell or the second bipolar cell.

[0017] In the embodiments, the plurality of bipolar cells further include a pair of electrode plates disposed respectively on the upper and lower surfaces of an electrode assembly in which a plurality of bipolar electrodes are stacked, and the edges of the pair of electrode plates may be in contact with a cooling member.

[0018] In the embodiments, at least one of the plurality of bipolar cells may further include a plurality of current collector plates electrically connected to the plurality of bipolar cells; and one or more terminals electrically connected to at least one of the plurality of current collector plates and exposed to the outside of the end cover.

[0019] In the embodiments, at least one of the plurality of bipolar cells may include a first end cover covering one side of a cell stack; a second end cover covering the other side of a cell stack; a pair of first terminals exposed to the outside of the first end cover and arranged along the longitudinal direction of the first end cover; and a pair of second terminals exposed to the outside of the second end cover and arranged along the longitudinal direction of the second end cover.

[0020] In the embodiments, a plurality of bipolar cells further include an electrode plate disposed on the upper or lower surface of an electrode assembly in which a plurality of bipolar electrodes are stacked and electrically connected to the electrode assembly, and the electrode plate of any one bipolar cell may be electrically connected by contacting the electrode plate of another bipolar cell in a first direction.

[0021] In the embodiments, the cell stack comprises a first sub-stack in which some of the bipolar cells among a plurality of bipolar cells are stacked; and a second sub-stack in which other of the bipolar cells among a plurality of bipolar cells are stacked, disposed facing the first sub-stack in a first direction with a current collection plate in between, and the first sub-stack and the second sub-stack may be electrically connected in parallel with each other.

[0022] According to the embodiments, a battery device including a bipolar cell capable of implementing high voltage can be provided.

[0023] In addition, according to the embodiments, a battery device with increased stability and efficiency in terms of electrical and mechanical connections of a plurality of bipolar cells can be provided.

[0024] In addition, according to the embodiments, a battery device having high cooling efficiency while including a plurality of bipolar cells can be provided.

[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 a reference diagram for explaining the connection between two bipolar batteries according to one embodiment.

[0035] FIG. 11 is a part of a side view of a bipolar battery 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 combined cross-sectional view of two bipolar batteries according to one embodiment.

[0038] FIG. 14 is an exemplary exploded perspective view of a battery device according to one embodiment.

[0039] FIG. 15 is an exemplary cross-sectional view along the line II-II' of FIG. 14 with the bipolar cell and cooling member coupled to the housing.

[0040] Figure 16 is an enlarged view of part A of Figure 15.

[0041] FIG. 17 is a top view of a battery device according to one embodiment.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] FIG. 1 is a perspective view of a battery device (1) including a bipolar battery (10) according to one embodiment.

[0049] A battery device (1) according to one embodiment may include one or more bipolar cells (10) and a housing (20).

[0050] 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.

[0051] 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 (ESS), as well as battery modules.

[0052] Referring further to FIG. 1, one or more bipolar cells (10) included in the battery device (1) can be accommodated in a housing (20).

[0053] 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 positioned on top of the plurality of support beams (22) to close the receiving space of the housing (20).

[0054] 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.

[0055] 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).

[0056] The lower plate (21) or the support beam (22) may be formed from 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).

[0057] 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.

[0058] FIG. 2 is a perspective view of a bipolar battery (10) according to one embodiment.

[0059] FIG. 3 is an exploded perspective view of a bipolar battery (10) according to one embodiment.

[0060] FIG. 4 is an exploded perspective view of a cell stack (CS) included in a bipolar battery (10) according to one embodiment.

[0061] FIG. 5 is an exploded perspective view of a bipolar cell (100) included in a bipolar battery (10) according to one embodiment.

[0062] FIG. 6 is an exemplary cross-sectional view of a bipolar cell (100) along the line II' of FIG. 5.

[0063] 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.

[0064] 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).

[0065] 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.

[0066] 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.

[0067] In one embodiment, the cell stacking direction may be approximately parallel to the direction in which the bipolar cell (10) is seated in the housing (20) of the battery device (1). By making the cell stacking direction parallel to the direction in which the bipolar cell (10) is seated in the battery device (1), a plurality of bipolar cells (100) can be intensively stacked and arranged within the housing (20).

[0068] 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).

[0069] Referring to FIG. 3, 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.

[0070] In various embodiments of the present disclosure, the cell stack (CS) may again 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).

[0071] In any one substack (CSa, CSb), a plurality of bipolar cells (100) may be stacked along a first direction (Z-axis direction) and electrically connected in series with each other. For example, the first substack (CSa) and the second substack (CSb) may each include a plurality of bipolar cells (100) electrically connected in series with each other while stacked along the first direction (Z-axis direction).

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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).

[0076] 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).

[0077] 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 FIGS. 2 and FIGS. 3 together, in any 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 an 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 be moved to the positive electrode layer through the current collector (111).

[0078] 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.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] A separator (120) is disposed between multiple bipolar electrodes (110) to prevent the bipolar electrodes (110) from coming into contact with each other and short-circuiting.

[0083] For example, the separator (120) may be a porous film membrane disposed between a plurality of bipolar electrodes (110). The separator (120) may be impregnated with a liquid 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 may be reduced compared to a battery cell with a separator (120) structure impregnated with a liquid electrolyte, while structural stability may be 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.

[0084] 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.

[0085] The sealing portion (130) can surround and seal the electrode stack (ES). For example, the sealing portion (130) may be 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.

[0086] 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).

[0087] 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).

[0088] 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 each have different electrical polarities due to the anode layer / cathode layer in contact with each other.

[0089] 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).

[0090] 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, a unit cell can be realized in which the electrical resistance in the terminal area is very low and the thermal energy generated by the resistance is also very low.

[0091] 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). Accordingly, 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.

[0092] A bipolar cell (100) according to one embodiment of the present invention 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.

[0093] 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).

[0094] 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.

[0095] 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.

[0096] 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).

[0097] 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.

[0098] 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.

[0099] 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 interposed between them. For example, the sealing member may include various polymer resin films, including PP film. However, the material of the sealing member 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.

[0100] In one embodiment, a plurality of bipolar cells (100) of one sub-stack (CSa, CSb) can 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) can be in contact with the second electrode plate (160) of the lower bipolar cell (100), and accordingly, the upper bipolar cell (100) and the lower bipolar cell (100) can be electrically connected in series. As a result of the plurality of bipolar cells (100) being electrically connected by being in direct contact through their respective electrode plates (150, 160), a connecting member (e.g., a conductive busbar) that was previously used to interconnect conventional battery cells can be omitted. In particular, at least one bipolar cell (100) has a high voltage value as a plurality of bipolar electrodes (110) inside it are connected in series with one another. This direct contact method between the bipolar cells (100) reduces the connection resistance between the bipolar cells (100), which is highly advantageous for electrical stability and temperature stability. In this way, a plurality of bipolar cells (100) stacked along a first direction (Z-axis direction) can be electrically connected in series with one another to form a sub-stack (CSa, CSb) having a high voltage. However, if necessary, a conductive connector may be added between two bipolar cells (100) stacked adjacent to each other vertically.

[0101] 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).

[0102] In one embodiment, the busbar assembly (500, 600) may include a conductive inner busbar (510, 610) electrically connected to the bipolar cell (100), a busbar frame (520, 620) 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).

[0103] 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 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 direction perpendicular to the first direction (Z-axis direction). In the following description, the direction in which the busbar assemblies (500, 600) and the cell stack (CS) face each other is referred to as the "second direction." That is, the first busbar assembly (500) and the second busbar assembly (600) may be positioned apart in a second direction (e.g., X-axis direction) perpendicular to the first direction (Z-axis direction) with the cell stack (CS) in between.

[0104] 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).

[0105] 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.

[0106] 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).

[0107] 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 first terminals (530) 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.

[0108] 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.

[0109] 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) in the bipolar battery (10) is set, 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 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.

[0110] 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).

[0111] 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.

[0112] 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).

[0113] 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.

[0114] 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).

[0115] 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.

[0116] 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. 10 to 13.

[0117] 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).

[0118] 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.

[0119] In one embodiment, the bipolar cell (10) may further include a pair of pressure plates (300) covering the upper and lower surfaces of the cell stack (CS). For example, the pair of pressure plates (300) may include a first pressure plate (310) and a second pressure plate (320) that are spaced apart in a first direction (Z-axis direction) with the cell stack (CS) in between to protect the upper and lower surfaces of the cell stack (CS).

[0120] 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).

[0121] 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).

[0122] 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.

[0123] 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 prevent the cell stack (CS) and the pressure plate (300) from being electrically short-circuited to each other, while also performing the function of 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.

[0124] 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.

[0125] FIG. 7 is a perspective view of a first busbar assembly (500) of a bipolar battery (10) according to one embodiment.

[0126] FIG. 8 is an exemplary exploded perspective view of a first busbar assembly (500) according to one embodiment.

[0127] FIG. 9 is a perspective view of a second busbar assembly (600) of a bipolar battery (10) according to one embodiment.

[0128] 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.

[0129] 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.

[0130] 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).

[0131] 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).

[0132] 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).

[0133] 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 different 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 different current collection plates (210, 220, 230).

[0134] 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).

[0135] 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 as to penetrate the busbar frame (520, 620). For example, referring to FIG. 7, the connecting plate (211) of the first current collection plate (210) may be formed by bending a portion of the first current collection plate (210) so as to penetrate from one side facing the cell stack (CS) in the first busbar frame (520) toward the other side opposite thereto, and to be in close contact with the first internal busbar (511) disposed on the first busbar frame (520).

[0136] 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.

[0137] 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).

[0138] The busbar frame (520, 620) can structurally fix the inner busbar (510, 610) in the event of external shock or vibration. For example, the busbar frame (520, 620) may include a polymer resin material having insulating properties and excellent mechanical strength, and thus can structurally support the inner busbar (510, 610) while ensuring insulation.

[0139] 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 direction parallel to the first direction (Z-axis direction). These connecting pins (521) can be inserted into the pressure plate (300) and fixed to 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.

[0140] A terminal (530, 630) may be formed in each internal busbar (510, 610). For example, referring to FIGS. 7 to 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 coupling one terminal (530, 630) with another terminal (530, 630).

[0141] 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.

[0142] 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 are in contact with 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 one connecting portion (512a, referred to as the second connecting portion) formed therein that is connected to the connecting plate (231) of the third current collection plate (230). 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 a parallel circuit having a pair of first terminals (530) with opposite electrical polarities can be formed.

[0143] 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).

[0144] In one embodiment, the first busbar assembly (500) may further include a sensing unit (540) electrically connected to a 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)).

[0145] 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).

[0146] Additionally, through a pair of terminals (530, 630) each disposed on both sides of the bipolar battery (10), other bipolar batteries (10) can be connected in series or parallel to both sides of the bipolar battery (10). Accordingly, various types of power circuits can be implemented using the same bipolar battery (10).

[0147] Hereinafter, with reference to FIGS. 10 to 12, the connection structure between a plurality of bipolar batteries (10) will be described in detail.

[0148] FIG. 10 is a reference diagram for explaining the connection between two bipolar batteries (10) according to one embodiment.

[0149] FIG. 11 is a part of a side view of a bipolar battery (10) according to one embodiment.

[0150] FIG. 12 is a part of a side view of a bipolar battery (10) according to one embodiment.

[0151] FIG. 13 is a part of a combined cross-sectional view of two bipolar batteries (10) according to one embodiment.

[0152] Since the bipolar battery (10) described in FIGS. 10 to 13 includes all the features of the bipolar battery (10) described in FIGS. 1 to 9, descriptions that overlap with FIGS. 1 to 9 may be omitted.

[0153] FIG. 10 illustrates two bipolar batteries (10) being electrically connected to each other, and it should be noted that the end cover (400) in the drawing has been omitted.

[0154] In one embodiment, a plurality of bipolar batteries (10) can be electrically connected to each other through connections between terminals (530, 630). For example, in a first bipolar battery (10a) and a second bipolar battery (10b) arranged so that their end covers (400) face each other, 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.

[0155] In one embodiment, a plurality of bipolar batteries (10) may have terminals (530, 630) that are in direct contact with each other and electrically connected. For example, referring to FIG. 10, 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 be joined by contacting each other in a first direction (Z-axis direction). 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 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 connection structure of the first terminal (530) and the second terminal (630) is not limited to that described above. For example, the first terminal (530) and the second terminal (630) may be welded together in a direct contact state.

[0156] In this way, multiple bipolar cells (10) can be connected in a manner where the terminals (530, 630) come into direct contact, thereby eliminating the 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 portion of the 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. Additionally, since the terminals (530, 630) are directly connected to each other, additional conductive connecting members can be eliminated, thereby reducing manufacturing costs.

[0157] 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. 11 and FIGS. 12 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.

[0158] First, referring to FIG. 11, 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).

[0159] 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. 11, 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).

[0160] Referring to FIG. 12, 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).

[0161] 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, and in this case, the first terminals (530) of each bipolar battery (10) may be electrically connected by touching each other.

[0162] 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. 12, 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).

[0163] In one embodiment, two adjacent bipolar cells (10) can be fixed to each other by joining their end covers (400). Such a joining structure is illustrated with reference to FIG. 13. The second end cover (420) of the first bipolar cell (10a) may include a second protrusion (421) protruding in a direction toward the second bipolar cell (10b), and the first end cover (410) of the second bipolar cell (10b) may include a first protrusion (411) protruding in a direction toward the first bipolar cell (10a). The second protrusion (421) of the first bipolar cell (10a) and the first protrusion (411) of the second bipolar cell (10b) may overlap in a first direction (Z-axis direction). Alternatively, the second step portion (421a) of the first bipolar cell (10a) and the first step portion (411a) of the second bipolar cell (10b) may overlap in a first direction (Z-axis direction). Here, the fact that the two members 'overlap in a first direction (Z-axis direction)' may mean that when a virtual line extending along the first direction (Z-axis direction) is assumed, this virtual line passes through both members.

[0164] In one embodiment, the second protrusion (421) of the first bipolar cell (10a) and the first protrusion (411) of the second bipolar cell (10b) may be joined together by contacting each other in a first direction (Z-axis direction). According to the structure in which the two end covers (400) are joined by contacting each other in this way, when arranging a plurality of bipolar cells (10) within the housing (20), each end cover (400) can be utilized as an alignment guide structure between the bipolar cells (10). For example, when placing one bipolar cell (10) inside the housing (20), it can be positioned in a position that contacts the protrusion of the end cover (400) of another bipolar cell (10) already placed inside the housing (20), thereby allowing it to be positioned correctly inside the housing (20).

[0165] In one embodiment, the first bipolar battery (10a) and the second bipolar battery (10b) can be coupled to each other through a fastening member (70) that is simultaneously fastened to each end cover (400). For example, referring to FIG. 13, the fastening member (70) can be coupled to the other by penetrating either the second protrusion (421) of the first bipolar battery (10a) or the first protrusion (411) of the second bipolar battery (10b), thereby securing the first bipolar battery (10a) and the second bipolar battery (10b) to each other.

[0166] 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) 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 the above description, and, for example, a fusion, welding, or snap-fit ​​coupling method between the end covers (400) may be applied.

[0167] Referring together to FIGS. 11 to 13, in one embodiment, the first terminal (530) may be spaced apart from the first stepped portion (411a) of the first end cover (410) by a first gap (d1) in the first direction (Z-axis direction), and the second terminal (630) may be spaced apart from the second stepped portion (421a) of the second end cover (420) by a second gap (d2) in the first direction (Z-axis direction). Here, the first gap (d1) may be smaller than the second gap (d2), and accordingly, a connection structure such as that of FIG. 13 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.

[0168] 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 (530, 630) 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 (530, 630) 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).

[0169] FIG. 14 is an exemplary exploded perspective view of a battery device (1) according to one embodiment.

[0170] FIG. 15 is an exemplary cross-sectional view along the line II-II' of FIG. 14 with the bipolar cell (10) and cooling member (60) coupled to the housing (20).

[0171] Figure 16 is an enlarged view of part A of Figure 15.

[0172] In one embodiment, the battery device (1) may include a cooling member (60) configured to cool the bipolar cell (10).

[0173] In one embodiment, the cooling member (60) may include a cooling frame (61) disposed on at least one side of the bipolar cell (10) and a refrigerant flow path (62) formed inside the cooling frame (61).

[0174] Referring to FIG. 14, a pair of cooling frames (61) may be provided and positioned facing each other on the support beams (22) on both sides of the housing (20). Each cooling frame (61) may extend in a second direction (X-axis direction), which is the direction in which a plurality of bipolar cells (10) are arranged. Accordingly, one of the cooling frames (61) may be positioned facing each of the plurality of bipolar cells (10) in a third direction (Y-axis direction).

[0175] The cooling frame (61) can be fixed to the housing (20) or the bipolar battery (10) through fastening members such as bolts. However, the connection structure of the cooling frame (61) is not limited to that described above. For example, the cooling frame (61) may be fixed to the housing (20) through a snap-fit ​​connection, welding, adhesive bonding, etc. Alternatively, the cooling frame (61) may be directly connected to a plurality of bipolar batteries (10) to form a single assembly together with the plurality of bipolar batteries (10) and then accommodated inside the housing (20).

[0176] The cooling frame (61) may be formed from a material with excellent thermal conductivity. For example, the cooling frame (61) may include a metal material having high thermal conductivity, such as aluminum or stainless steel. A cooling frame (61) including such a material can rapidly absorb heat generated from a plurality of bipolar cells (10).

[0177] To improve cooling efficiency, a heat transfer member (63) may be disposed between the cooling frame (61) and the plurality of bipolar cells (10). The heat transfer member (63) may be disposed such that one side contacts at least one of the plurality of bipolar cells (10), and the other side opposite to the one side contacts the cooling frame (61). For example, the heat transfer member (63) may include a thermal interface material (TIM) or a thermal adhesive. The heat transfer member (63) may fill the space between the side of the bipolar cell (10) and the cooling frame (61) to allow heat transfer by conduction to occur more actively. Accordingly, the heat dissipation efficiency of the battery device (1) may be increased. However, in various embodiments of the present disclosure, the heat transfer member (63) may be omitted.

[0178] Referring to FIG. 15 and FIG. 16 together, in one embodiment, the cooling member (60) may further include a refrigerant flow path (62) formed in the cooling frame (61). A refrigerant may flow inside the refrigerant flow path (62). The refrigerant may be a fluid material for cooling, for example, cooling water.

[0179] In one embodiment, the refrigerant flow path (62) may be provided so that the refrigerant can flow evenly throughout the entire interior area of ​​the cooling frame (61). To this end, the refrigerant flow path (62) may be provided as a path that bends at least once inside the cooling frame (61). However, the specific structure of the refrigerant flow path (62) is not limited to that described above and may be provided to form various refrigerant flow paths as needed.

[0180] In one embodiment, the cooling frame (61) or the housing (20) may include a plurality of refrigerant ports through which refrigerant can flow in and out. The refrigerant ports of the cooling frame (61) and the refrigerant ports of the housing (20) may be interconnected, so that refrigerant introduced from outside the housing (20) can be introduced into the refrigerant flow path (62) inside the cooling frame (61).

[0181] Referring to FIG. 15 and FIG. 16 together, the cooling frame (61) may be positioned to face a plurality of bipolar cells (100) included in the bipolar battery (10) in a third direction (Y-axis direction), and a heat transfer member (63) may be positioned to fill the space between the cooling frame (61) and the bipolar cells (100).

[0182] In the bipolar cell (10), a plurality of bipolar cells (100) may be arranged so as to be exposed to the side of the bipolar cell (10). For example, as shown in FIGS. 15 and 16, the side of a plurality of bipolar cells (100) may be exposed between a pair of pressure plates (300) and may come into direct contact with a cooling frame (61) or a heat transfer member (63).

[0183] Referring to FIG. 16, in any bipolar cell (100), the first electrode plate (150) and the second electrode plate (160) forming the lower and upper surfaces of the bipolar cell (100) may be configured such that their edges are bent to wrap around the corners of the cell frame (140). Accordingly, the bent portions of the first electrode plate (150) and the second electrode plate (160) may be exposed to the side of the bipolar cell (100). The bent portions of the first electrode plate (150) and the second electrode plate (160) may be spaced apart from each other with the protrusion (141) of the cell frame (140) in between. The protrusion (141) of the cell frame (140) can prevent an electrical short circuit from occurring between the bent portion of the first electrode plate (150) and the bent portion of the second electrode plate (160).

[0184] In one embodiment, the cooling frame (61) or the heat transfer member (63) may come into contact with the bent portion of the first electrode plate (150) and the bent portion of the second electrode plate (160). As previously described through FIGS. 5 and 6, the electrode plates (150, 160) include a conductive metal material, so they may have excellent thermal conductivity. Due to the structure in which the cooling member (60) comes into contact with the first electrode plate (150) and the second electrode plate (160), which include a metal material having excellent thermal conductivity, the heat dissipation efficiency in each bipolar cell (100) can be further increased.

[0185] In one embodiment, referring to FIG. 15, the bipolar cell (10) may have a protruding portion on the side of the cell stack (CS) due to internal components such as current collection plates (210, 220, 230) placed between the bipolar cells (100), and to avoid collision with such protruding portion, a avoidance portion (61a) may be formed in the cooling frame (61). For example, the avoidance portion (61a) may have the form of a recess formed on the surface of the cooling frame (61) facing the cell stack (CS) of the bipolar cell (10).

[0186] FIG. 17 is a top view of a battery device (1) according to one embodiment.

[0187] Since the bipolar cell (10) and battery device (1) described in FIG. 17 include all the features of the bipolar cell (10) and battery device (1) described in FIG. 1 to 16, descriptions that overlap with FIG. 1 to 16 may be omitted.

[0188] A battery device (1) according to one embodiment may include a plurality of bipolar cells (10) electrically connected to each other, a control module, and a housing (20) that accommodates them. For example, referring to FIG. 17, the battery device (1) may include a first bipolar cell (10a), a second bipolar cell (10b), and a third bipolar cell (10c) that are electrically connected to each other and arranged along a second direction (X-axis direction).

[0189] A plurality of bipolar cells (10) can be electrically connected by having their respective terminals (e.g., 530, 630 in FIG. 2) in direct contact. For a detailed description of the terminals (530, 630) of individual bipolar cells (10), refer to FIG. 1 through FIG. 13.

[0190] In one embodiment, some of the plurality of bipolar batteries (10) may have a structure in which a pair of terminals are arranged on one side and the other side respectively, allowing for electrical connection in both directions (hereinafter referred to as a "bidirectional connection structure"), while others may have a structure in which a pair of terminals is arranged only on one side, allowing for electrical connection in only one direction (hereinafter referred to as a "unidirectional connection structure"). For example, the bidirectional connection structure may be implemented by a pair of first terminals (530) and a pair of second terminals (630) of the bipolar batteries (10) described above in FIGS. 1 to 13.

[0191] In one embodiment, the first bipolar battery (10a) has a bidirectional connection structure and can be electrically connected to the control module (30) and the second bipolar battery (10b), respectively. For example, a pair of first terminals (530) may be disposed on one side of the first bipolar battery (10a), and a pair of second terminals (630) may be disposed on the other side, wherein the pair of first terminals (530) may be electrically connected to the control module (30), and the pair of second terminals (630) may be electrically connected to the second bipolar battery (10b).

[0192] The control module (30) may be configured to monitor or control the status of a plurality of bipolar cells (10) housed within the battery device (1). For example, the control module (30) may be a battery management system (BMS) configured to detect and control the status, such as voltage or temperature, of each bipolar cell (10), or a battery disconnect unit (BDU) configured to control the electrical connection between the bipolar cells (10). The BMS may be configured to monitor the current, voltage, and temperature of each bipolar cell (10), and based on the monitoring results, may calculate the Status of Charge (SOC), State of Health (SoH), and State of Power (SoP), and appropriately control the bipolar cells (10) accordingly. The BDU may include a relay circuit and is configured to cut off the electrical connection between the electrical components (e.g., power converter) inside the battery device (1) and the bipolar cell (10) when a current exceeding a preset range occurs in the battery device (1), thereby performing the role of protecting the battery device (1).

[0193] In one embodiment, the battery device (1) may further include an external busbar (40) connecting the first bipolar battery (10a) and the control module (30). For example, the external busbar (40) may be electrically connected to a pair of first terminals (530) of the first bipolar battery (10a) and a terminal portion of the control module (30), respectively, to electrically connect the first bipolar battery (10a) and the control module (30). However, in various embodiments, a pair of first terminals (530) of the first bipolar battery (10a) may be in direct contact with a terminal portion of the control module (30), in which case the external busbar (40) may be omitted.

[0194] In one embodiment, the second bipolar battery (10b) has a bidirectional connection structure and can be electrically connected to the first bipolar battery (10a) and the third bipolar battery (10c), respectively. For example, a pair of first terminals (530) may be disposed on one side of the second bipolar battery (10b), and a pair of second terminals (630) may be disposed on the other side, wherein the pair of first terminals (530) may be electrically connected to the first bipolar battery (10a), and the pair of second terminals (630) may be electrically connected to the third bipolar battery (10c).

[0195] In one embodiment, among the plurality of bipolar batteries (10), the third bipolar battery (10c) located at the outermost position in the second direction (X-axis direction) has a unidirectional connection structure and can be electrically connected to the second bipolar battery (10b). For example, a pair of first terminals (530) may be disposed on one side of the third bipolar battery (10c), wherein the pair of first terminals (530) can be electrically connected to the second bipolar battery (10b). Another bipolar battery (10) may not be disposed on the other side of the third bipolar battery (10c), and accordingly, a pair of terminals (e.g., a pair of first terminals (530)) may be disposed only on one side of the third bipolar battery (10c), and a terminal (e.g., a pair of second terminals (630)) may not be disposed on the other side.

[0196] Meanwhile, in a bipolar battery (10c) having a unidirectional connection structure, a pair of terminals (e.g., a pair of first terminals (530)) are arranged on only one side, so the busbar assembly (e.g., a second busbar assembly (600)) and a pair of terminals (e.g., a pair of second terminals (630)) on the other side may be omitted, and other technical features may be the same as those of other bipolar batteries (10a, 10b) having a bidirectional connection structure.

[0197] 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.

[0198] 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 plurality of bipolar cells comprising a plurality of bipolar cells each including a plurality of bipolar electrodes stacked along a first direction, at least one pressure plate disposed facing the cell stack in the first direction, and at least one end cover coupled to the at least one pressure plate and covering the cell stack in a second direction intersecting the first direction; and It includes a housing that accommodates the plurality of bipolar cells mentioned above, The above plurality of bipolar batteries, A battery device comprising a first bipolar cell and a second bipolar cell arranged along the second direction inside the housing and electrically connected to each other.

2. In Paragraph 1, A battery device in which the end cover of the first bipolar battery is combined with the end cover of the second bipolar battery.

3. In Paragraph 2, The end cover of the second bipolar battery includes a first protrusion protruding in a direction toward the first bipolar battery, and The end cover of the first bipolar battery includes a second protrusion protruding in a direction toward the second bipolar battery, and A battery device in which at least a portion of the first protrusion overlaps with the second protrusion in the first direction.

4. In Paragraph 3, A battery device in which the first protrusion and the second protrusion are in contact with each other in the first direction.

5. In Paragraph 4, A battery device further comprising a fastening member that penetrates either of the first protrusion and the second protrusion and is coupled to the other.

6. In Paragraph 1, A battery device further comprising a cooling member extending along the second direction from one side of the first bipolar battery or one side of the second bipolar battery.

7. In Paragraph 6, A battery device in which the cooling member is positioned to face the side of the first bipolar cell and the side of the second bipolar cell in a third direction that intersects both the first direction and the second direction.

8. In Paragraph 7, A battery device having the cell stack exposed on the side facing the cooling member of the first bipolar cell and the side facing the cooling member of the second bipolar cell.

9. In Paragraph 7, The above cooling member is A cooling plate having a refrigerant flow path formed therein through which the refrigerant flows; and A battery device comprising a heat transfer member disposed between at least one of the first bipolar cell or the second bipolar cell and the cooling plate.

10. In Paragraph 9, The above heat transfer member is a battery device in contact with the bipolar cell included in the first bipolar battery or the bipolar cell included in the second bipolar battery.

11. In Paragraph 6, The above plurality of bipolar cells are, The electrode assembly further includes a pair of electrode plates respectively disposed on the upper and lower surfaces of the electrode assembly in which the plurality of bipolar electrodes are stacked, and A battery device in which the edges of a pair of electrode plates are in contact with the cooling member.

12. In Paragraph 1, At least one of the plurality of bipolar batteries above is, A plurality of current collection plates electrically connected to the plurality of bipolar cells above; and A battery device comprising at least one terminal electrically connected to at least one of the plurality of current collection plates and further including one or more terminals exposed to the outside of the end cover.

13. In Paragraph 12, At least one of the plurality of bipolar batteries above is A first end cover covering one side of the cell stack; A second end cover covering the other side of the cell stack; A pair of first terminals exposed to the outside of the first end cover and arranged along the longitudinal direction of the first end cover; and A battery device comprising a pair of second terminals exposed to the outside of the second end cover and arranged along the longitudinal direction of the second end cover.

14. In Paragraph 1, The above plurality of bipolar cells are, The electrode assembly further includes an electrode plate disposed on the upper or lower surface of the electrode assembly in which the plurality of bipolar electrodes are stacked and electrically connected to the electrode assembly. A battery device in which the electrode plate of one bipolar cell is electrically connected to the electrode plate of another bipolar cell by contacting it in the first direction.

15. In Paragraph 1, The above cell stack is, A first substack in which some of the plurality of bipolar cells are stacked; and It includes a second substack which is positioned facing the first substack in the first direction with a current collection plate in between, and in which some of the other bipolar cells among the plurality of bipolar cells are stacked. A battery device in which the first sub-stack and the second sub-stack are electrically connected in parallel with each other.

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