Battery cell and battery device comprising same

Abstract

The battery device according to the present disclosure may comprise: a battery cell assembly, wherein a first battery cell and a second battery cell are stacked in a first direction; each of the first cell and the second cell may include: an accommodation portion in which an electrolyte and an electrode assembly are accommodated in a case; the plurality of expansion parts are formed by protruding outwards from the accommodating part along the first direction, and the second battery cell can be in contact with at least one of the expansion parts of the first battery cell.

Description

Technical Field

[0001] The present invention relates to a battery cell and a battery device comprising the battery cell. Background Art

[0002] Unlike primary batteries, secondary batteries can be charged and discharged, making them suitable for a wide range of applications, including digital cameras, mobile phones, laptop computers, hybrid vehicles, and electric vehicles. Research is actively underway on lithium secondary batteries, which offer high energy density and high discharge voltage. Lithium secondary batteries can be manufactured in flexible pouch-type cells or rigid prismatic or cylindrical can-type cells.

[0003] A plurality of battery cells may be mounted in a case in units of cell assemblies stacked and electrically connected to each other to be manufactured into a battery device such as a battery module or a battery pack and mounted in an electric vehicle or the like.

[0004] Since such a battery device generates heat in the battery cell during operation, a structure that can effectively dissipate heat is required. Summary of the Invention

[0005] (1) Technical issues to be resolved

[0006] According to one aspect of the present disclosure, a battery cell and a battery device capable of improving the heat dissipation efficiency of the battery cell can be provided.

[0007] The battery device according to the present disclosure can be widely used in electric vehicles, battery charging stations, and other green technology fields such as solar power generation and wind power generation using batteries. Furthermore, the battery device according to the present disclosure can be used in eco-friendly electric vehicles and hybrid vehicles, which prevent climate change by suppressing air pollution and greenhouse gas emissions.

[0008] (2) Technical solution

[0009] According to the present disclosure, the battery device may include: a battery cell assembly, a first battery cell and a second battery cell stacked along a first direction; each of the first battery cell and the second battery cell may include: a housing portion for housing an electrolyte and an electrode assembly within a shell; and a plurality of extension portions formed to protrude outward from the housing portion along the first direction, and the second battery cell may be in contact with at least one of the extension portions of the first battery cell.

[0010] According to one embodiment, each of the expansion portions may be disposed such that at least a portion thereof faces the electrode assembly.

[0011] According to one embodiment, an air gap may be formed between the first battery cell and the second battery cell, and a distance of the air gap may correspond to a protruding distance of the expansion portion.

[0012] According to one embodiment, a protruding end portion of at least one of the expanded portions of the first battery cell may be in contact with one of the expanded portions of the second battery cell.

[0013] According to one embodiment, the first battery cell and the second battery cell may be arranged so that at least a portion of a groove portion formed between the expanded portions of the first battery cell overlaps with a groove portion formed between the expanded portions of the second battery cell.

[0014] According to one embodiment, at least one of the expansion portions of the first battery cell may be disposed within the groove portion of the second battery cell.

[0015] According to one embodiment, the width of each of the expansion portions may be narrower as it becomes farther from the electrode assembly.

[0016] According to one embodiment, each of the expansion portions may be formed to protrude from the receiving portion in a prism shape.

[0017] According to one embodiment, the plurality of expansion portions may be formed by stretching the housing, and the internal space of each expansion portion may be filled with the electrolyte.

[0018] According to one embodiment, each of the expansion portions may be formed in a straight line parallel to a length direction of the electrode assembly.

[0019] In addition, the battery cell according to the present disclosure may be a battery cell that seals the electrolyte and electrode assembly in a shell, wherein the shell may include a plurality of extension parts, which are formed to protrude outward along the thickness direction of the battery cell, and the electrolyte can be filled inside the extension parts.

[0020] According to one embodiment, on one side of the housing, at least two of the plurality of expansion portions may be spaced apart by a predetermined distance.

[0021] (3) Beneficial effects

[0022] According to one embodiment of the present disclosure, cooling channels may be formed between battery cells simply by stacking the battery cells on top of each other without a separate component. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a perspective view of a battery cell according to an embodiment of the present disclosure.

[0024] Figure 2 yes Figure 1A partially exploded view of the battery cell is shown.

[0025] Figure 3 It is along Figure 1 A cross-sectional view taken along I-I'.

[0026] Figure 4 It is an explanation Figure 2 A cross-sectional view of a method for manufacturing a housing is shown.

[0027] Figure 5 is a perspective view of a battery device according to an embodiment of the present disclosure.

[0028] Figure 6 yes Figure 5 An exploded perspective view of the battery device shown.

[0029] Figure 7 It is along Figure 5 A cross-sectional view taken along II-II'.

[0030] Figure 8 is a cross-sectional view of a battery device according to another embodiment.

[0031] Figure 9 is a cross-sectional view of a battery device according to yet another embodiment.

[0032] Description of reference numerals:

[0033] 10: Battery device

[0034] 30: Shell

[0035] 70: Busbar assembly

[0036] 100: Battery Cell

[0037] 110: Shell

[0038] 130: Electrode assembly

[0039] 140: Sealing part

[0040] 150: Accommodation

[0041] 160: Extension Department DETAILED DESCRIPTION

[0042] Hereinafter, the present disclosure will be described in detail with reference to the accompanying drawings. However, this is only exemplary, and the present disclosure is not limited to the specific embodiments described exemplarily.

[0043] Figure 1 is a three-dimensional diagram of a battery cell according to an embodiment of the present disclosure, Figure 2 yes Figure 1 The partial exploded view of the battery cell shown. Figure 3 It is along Figure 1The cross-sectional view taken along I-I' is shown in FIG. Figure 4 It is an explanation Figure 2 A cross-sectional view of a method for manufacturing a housing is shown.

[0044] Reference Figures 1 to 4 , the battery cell 100 according to the embodiment may include an electrode assembly 130 and a case 110 accommodating the electrode assembly 130 .

[0045] The battery cell 100 according to this embodiment is a rechargeable secondary battery, and may include a lithium-ion (Li-ion) battery or a nickel-metal hydride (Ni-MH) battery. Such secondary batteries have a large capacity per unit volume and can be used not only as an energy source for electric vehicles (EVs) and hybrid electric vehicles (HEVs), but also for various applications such as energy storage.

[0046] The battery cell 100 of this embodiment may include a pouch type battery cell in which an electrode assembly 130 and an electrolyte are accommodated in a pouch type case.

[0047] like Figure 2 As shown, the case 110 of the battery cell 100 can be formed by folding a sheet of exterior material. Therefore, when describing this embodiment, the case and the exterior material can be understood as the same element.

[0048] The casing 110 defines the overall appearance of the battery cell 100 and seals the electrolyte and electrode assembly 130 contained therein, protecting them from the external environment. The casing 110 can be made of a bag-shaped exterior material with an insulating metal film surface. The metal film can be made of aluminum. A modified polypropylene, such as cast polypropylene (CPP), can be used as a polymer resin to form a heat-welded layer and coated on one side of the metal film. A resin material such as nylon or polyethylene terephthalate (PET) can be formed on the other side of the metal film.

[0049] For example, the battery cell 100 of this embodiment can be manufactured by the following steps: forming a housing space 113 in a sheet of exterior material by forming, etc.; housing the electrode assembly 130 in the housing space 113 and folding the exterior material along a folding line C; and sealing the housing space 113 by joining the edges of the casing 110. The edge joining method can be, but is not limited to, heat welding.

[0050] Hereinafter, a portion of the housing 110 forming the accommodation space 113 is referred to as an accommodation portion 150 , and an edge region along the periphery of the accommodation portion to which the exterior material is bonded is referred to as a sealing portion 140 .

[0051] In this embodiment, the sealing portion 140 may be divided into a first sealing portion 140 a formed at a portion where the electrode lead 120 is provided and a second sealing portion 140 b formed at a portion where the electrode lead 120 is not provided.

[0052] The sealing portion 140 may be formed in a flange shape extending outward from the receiving portion 150 .

[0053] In addition, the battery cell 100 of this embodiment may form the second sealing portion 140 b in a folded form at least once, so as to improve the bonding reliability of the sealing portion 140 and increase the energy density.

[0054] The housing 110 of this embodiment can be divided into a first housing 110a and a second housing 110b based on a fold line C formed by folding the outer material. Accommodation spaces 113 can be partially provided in each of the first housing 110a and the second housing 110b. However, the configuration of the present invention is not limited to this, and various modifications are possible. For example, the accommodation space 113 can be provided in only one of the first housing 110a and the second housing 110b. Alternatively, the first housing 110a and the second housing 110b can be formed from separate outer materials.

[0055] The electrode assembly 130 can be housed in the housing 150 of the housing 110 together with the electrolyte. The electrode assembly 130 can include a plurality of electrodes divided into positive and negative plates, and a separator disposed between the positive and negative plates to electrically and physically isolate the positive and negative plates. The overall shape of the electrode assembly 130 of this embodiment can be formed into a rectangular parallelepiped. However, the shape of the electrode assembly 130 is not limited thereto.

[0056] The electrode assembly 130 may include electrode tabs 135 protruding outward from multiple positive plates and multiple negative plates. Each electrode tab 135 may be connected to the electrode lead 120 so that electrode tabs 135 of the same polarity contact each other. The electrode tabs 135 may be disposed in a terrace 145. In this embodiment, the terrace 145 may refer to the space formed around the electrode assembly 130 in the accommodating portion 150 and the portion corresponding thereto. Therefore, the terrace 145 may be defined as the portion of the housing 110 corresponding to the space between the electrode assembly 130 and the sealing portion 140, or the portion of the housing 110 that is not in contact with the electrode assembly 130.

[0057] The electrode lead 120 is electrically connected to the electrode assembly 130 within the housing 150, and a portion of the electrode lead 120 may be exposed outside the housing 110. In the battery cell 100 of this embodiment, the two electrode leads 120 may be arranged to face in opposite directions. However, the present invention is not limited thereto; the two electrode leads 120 may also face in the same direction.

[0058] In addition, the battery cell 100 of this embodiment may form an expansion portion 160 in the housing 110 .

[0059] The extension portion 160 is formed by protruding outward from a portion of the housing 110 that forms the accommodating portion 150. In this embodiment, the extension portion 160 may protrude from the battery device 100, which will be described later, in a first direction (e.g., ±Y directions) in which the battery cells 100 are stacked. In this embodiment, the battery cells 100 may be stacked along the thickness direction of the accommodating portion 150 or the thickness direction of the battery cells 100. Therefore, the extension portion 160 may protrude outward from the accommodating portion 150 along the thickness direction of the accommodating portion 150.

[0060] like Figure 4 As shown, the expansion portion 160 can be formed together with the accommodating space 113 during the process of forming the accommodating space 113 of the housing 110 using the mold P. Therefore, the expansion portion 160 can be formed in the form of a protrusion protruding outward from the accommodating portion 150. In this embodiment, the expansion portion 160 can be formed by drawing the housing 110. Therefore, the internal space 161 of the expansion portion 160 can be formed in the form of a groove to expand the volume of the accommodating space 113.

[0061] The internal space 161 of the extension portion 160 may be filled with electrolyte. Therefore, the battery cell 100 of this embodiment may contain more electrolyte, thereby extending the battery life.

[0062] In this embodiment, the extension portion 160 may be formed in an area of the housing 110 corresponding to the side of the electrode assembly 130. Therefore, the extension portion 160 may be adjacent to the platform 145, or a portion of the extension portion 160 may be located in the platform 145. In addition, the entire extension portion 160 may be formed in the platform 145 as needed.

[0063] In this embodiment, the expansion portion 160 may be formed in a straight line parallel to the length direction (eg, X direction) of the electrode assembly 130 , and may be disposed such that at least a portion thereof faces the electrode assembly 130 .

[0064] Such expansion portion 160 may be formed on first and second surfaces S1, S2 of receiving portion 150, respectively, disposed along the thickness direction of receiving portion 150. Here, first and second surfaces S1, S2 of receiving portion 150 may refer to areas of the wide sides of case 110 forming receiving portion 150 facing electrode assembly 130.

[0065] The expansion portion 160 may be formed on at least one of the first surface S1 and the second surface S2. For example, a plurality of expansion portions 160 may be formed side by side on the first surface S1 and the second surface S2 of the receiving portion 150.

[0066] Since the plurality of extension portions 160 are formed to protrude outward from the receiving portion 150 , a groove-shaped space, ie, a groove portion 167 , may be formed between two extension portions 160 formed on one side of the receiving portion 150 .

[0067] When multiple battery cells 100 are stacked, the groove portion 167 can serve as a flow path for fluid such as air to pass through. Therefore, as long as the shape of the expansion portion 160 or the groove portion 167 is maintained, the protrusion distance of the expansion portion 160 or the width of the expansion portion 160 can be variously changed.

[0068] Next, the battery device 10 including the battery cell 100 of this embodiment will be described.

[0069] Figure 5 is a perspective view of a battery device according to an embodiment of the present disclosure, Figure 6 yes Figure 5 The exploded perspective view of the battery device shown, Figure 7 It is along Figure 5 A cross-sectional view taken along II-II'.

[0070] Reference Figures 5 to 7 The battery device 10 according to the embodiment may include a cell assembly 20 , a bus bar assembly 70 , and a housing 30 .

[0071] The battery cell assembly 20 can be formed by combining a plurality of the battery cells 100 described above, and the stacked state can be fixed by tape, brackets, etc. In this embodiment, the plurality of battery cells 100 can stand vertically within the housing 30 and can be stacked along the thickness direction of the accommodating portion 150, i.e., the first direction, so that the battery cell assembly 20 can be formed into an overall hexahedral shape.

[0072] The bus bar assemblies 70 may be respectively disposed on sides of the battery cells 100 where the electrode leads 120 are disposed, and combined with the battery cell assembly 20 . Each bus bar assembly 70 may include at least one bus bar 77 and an insulating frame 71 .

[0073] The insulation frame 71 may be formed of an insulation material, and the size of the insulation frame 71 may correspond to the entire side size of the battery cell assembly 20 facing the bus bar assembly 70 .

[0074] A plurality of through holes may be provided in the insulating frame 71 , and thus the electrode leads 120 may pass through the through holes and be fastened to the bus bars 77 .

[0075] The bus bar 77 may be formed in the form of a conductive metal plate, and at least a portion of the bus bar 77 may be embedded in the interior of the insulating frame 71 or attached to the outer surface of the insulating frame 71. The battery cells 100 may be electrically connected to each other via the bus bar 77. To this end, the electrode lead 120 may be joined to the bus bar 77 by welding or the like.

[0076] A plurality of bus bars 77 may be provided spaced apart side by side along the stacking direction of the battery cells 100 , and at least two battery cells 100 may be connected to one bus bar 77 .

[0077] The housing 30 defines the appearance of the battery device 10 and houses the cell assembly 20 therein to protect the cell assembly 20 from the external environment. Furthermore, the housing 30 of this embodiment can serve as a heat dissipation component for the cell assembly 20.

[0078] The housing 30 may be provided to surround all or part of the cell assembly 20. The housing 30 may be formed of a metal material to ensure rigidity, but is not limited thereto. In addition, at least a portion of the housing 30 may be formed of aluminum to improve heat dissipation efficiency.

[0079] To facilitate the manufacture of the battery device 10, the housing 30 can be divided into multiple parts. The housing 30 of this embodiment can include a first housing 30a covering the upper portion of the battery cell assembly 20, a second housing 30b covering the lower portion of the battery cell assembly 20, and a third housing 30c covering the side surfaces of the battery cell assembly 20, but is not limited thereto.

[0080] In addition, the battery cell assembly 20 of this embodiment may include at least one air gap AG. The air gap AG may be a space formed by the groove portion 167 of the battery cell 100 . Therefore, the interval of the air gap AG may correspond to the protrusion distance of the expansion portion 160 .

[0081] In the battery cells 100 constituting the battery cell assembly 20, the first battery cell 100a and the second battery cell 100b disposed continuously may contact each other through at least one expansion portion 160. The first battery cell 100a may contact at least one of the expansion portions 160 of the second battery cell 100b. For example, the first battery cell 100a may contact the second battery cell 100b only through the expansion portion 160 of the second battery cell 100b.

[0082] In addition, in the present embodiment, the protruding end of at least one of the extensions 160 of the first battery cell 100a may contact one of the extensions 160 of the second battery cell 100b. Specifically, when the first battery cell 100a and the second battery cell 100b are stacked on each other along the first direction, the extension 160 formed on the first surface S1 of the first battery cell 100a and the end of the extension 160 formed on the second surface S2 of the second battery cell 100b may contact each other. Therefore, when the first battery cell 100a and the second battery cell 100b are stacked on each other, an air gap AG may be formed between the first battery cell 100a and the second battery cell 100b, and the air gap AG may be formed by the space formed by the combination of the groove portion 167 of the first battery cell 100a and the groove portion 167 of the second battery cell 100b. However, the present disclosure is not limited thereto, and an air gap AG may also be formed by one groove portion 167 as in the embodiment to be described later.

[0083] The air gap AG configured in this manner can function as a cooling channel through which air flows and cools the battery cells 100. Therefore, the battery device 10 of this embodiment can form cooling channels between the battery cells 100 without interposing a separate component therebetween.

[0084] Furthermore, the air gap AG can serve as space for the battery cell 100 to expand. When the battery cell 100 expands due to, for example, battery swelling, the air gap AG can be reduced. Therefore, even if the first battery cell 100a expands, the impact on the second battery cell 100b is minimized. Thus, the battery device 10 of this embodiment can suppress deformation of the battery cell assembly 20 caused by swelling in a specific battery cell 100.

[0085] The following will further illustrate the embodiments of the present disclosure with reference to specific experimental examples. The examples and comparative examples included in the experimental examples are merely illustrative of the present disclosure and do not limit the appended claims. It is obvious to those skilled in the art that various changes and modifications can be made to the embodiments within the scope of the present disclosure and the technical concept, and such changes and modifications fall within the scope of the appended claims.

[0086] Figure 8 is a cross-sectional view of a battery device according to another embodiment, showing Figure 5 II-II' corresponds to the cross section.

[0087] Reference Figure 8In the battery cell 100 of this embodiment, the extension portion 160 may be formed on only one of the first surface S1 and the second surface S2 of the accommodating portion 150. Therefore, the extension portion 160 formed on the first surface S1 of the first battery cell 100a may contact the second surface S2 of the second battery cell 100b, which does not have the extension portion 160 formed thereon. Therefore, in this embodiment, one groove portion 167 may be formed by one air gap AG.

[0088] In addition, the battery cell 100 of this embodiment may be formed such that the entire extension portion 160 rather than a portion of the extension portion 160 faces the electrode assembly 130. Therefore, the extension portion 160 of this embodiment may be formed at a position spaced a predetermined distance from the platform 145.

[0089] In addition, the expansion portion 160 of this embodiment can be formed in a prism shape protruding from the receiving portion 150. The expansion portion 160 can be formed so that its width becomes narrower as it moves away from the electrode assembly 130. For example, the cross-section of the expansion portion 160 can be formed in a trapezoidal shape. However, this embodiment is not limited to this, and the cross-section of the expansion portion 160 can be variously modified, for example, the cross-section of the expansion portion 160 can be formed in a quadrilateral or triangular shape.

[0090] The battery device 10 of this embodiment configured in this manner can improve the rigidity of the extension portion 160 relative to the stacking direction of the battery cells 100 (eg, the Y direction), so that the extension portion 160 will not be easily deformed even if another adjacent battery cell 100 applies pressure to the extension portion 160 .

[0091] Figure 9 is a cross-sectional view of a battery device according to another embodiment, showing Figure 5 II-II' corresponds to the cross section.

[0092] Reference Figure 9 In the battery cell 100 of this embodiment, the expansion portion 160 is formed on both the first surface S1 and the second surface S2 of the accommodating portion 150. The expansion portion 160 of the first surface S1 and the expansion portion 160 of the second surface S2 can be formed at positions that do not face each other. Here, the non-facing position can refer to a position where the expansion portions 160 do not overlap or only partially overlap when the first surface S1 and the second surface S2 are projected onto each other based on the thickness direction of the battery cell 100.

[0093] Therefore, when the first battery cell 100a and the second battery cell 100b are stacked on each other along the first direction, the end portions of the extension portion 160 formed on the first side S1 of the first battery cell 100a and the end portions of the extension portion 160 formed on the second side S2 of the second battery cell 100b may not contact each other. For example, the end portion of the extension portion 160 formed on the first side S1 of the first battery cell 100a may contact the second side S2 of the second battery cell 100b, and the end portion of the extension portion 160 formed on the second side S2 of the second battery cell 100b may contact the first side S1 of the first battery cell 100a.

[0094] Therefore, in this embodiment, the first battery cell 100a and the second battery cell 100b may be arranged so that at least a portion of the groove portion 167 of the first battery cell 100a overlaps with the groove portion 167 of the second battery cell 100b. In addition, at least one of the expansion portions 160 of the first battery cell 100a may be disposed within the groove portion 167 of the second battery cell 100b.

[0095] The above description is only an example of applying the principles of the present disclosure, and other configurations may be included without departing from the scope of the present disclosure.

Claims

1. A battery device comprising: A battery cell assembly, wherein a first battery cell and a second battery cell are stacked along a first direction; Each of the first battery cell and the second battery cell includes: a receiving portion in which an electrolyte and an electrode assembly are received within a housing; and a plurality of expansion portions formed to protrude outward from the accommodation portion along the first direction, The second battery cell contacts at least one of the expanded portions of the first battery cell.

2. The battery device according to claim 1, wherein Each of the expanded portions is disposed so that at least a portion thereof faces the electrode assembly.

3. The battery device according to claim 1 or 2, wherein: An air gap is formed between the first battery cell and the second battery cell, The interval of the air gap corresponds to the protruding distance of the expansion portion.

4. The battery device according to claim 1 or 2, wherein: A protruding end portion of at least one of the expanded portions of the first battery cell contacts one of the expanded portions of the second battery cell.

5. The battery device according to claim 3, wherein: The first battery cell and the second battery cell are arranged so that at least a portion of a groove portion formed between the expanded portions of the first battery cell overlaps with a groove portion formed between the expanded portions of the second battery cell.

6. The battery device according to claim 5, wherein: At least one of the expanded portions of the first battery cell is disposed in the groove portion of the second battery cell.

7. The battery device according to claim 1 or 2, wherein: The farther away each of the expansion portions is from the electrode assembly, the narrower the width of the expansion portions becomes.

8. The battery device according to claim 1 or 2, wherein: Each of the expansion portions is formed in a prism shape and protrudes from the receiving portion.

9. The battery device according to claim 1 or 2, wherein: The plurality of extension portions are formed by stretching the shell. The inner space of each of the extension parts is filled with the electrolyte.

10. The battery device according to claim 1 or 2, wherein: Each of the expansion portions is formed in a straight line parallel to a length direction of the electrode assembly.

11. A battery cell, wherein an electrolyte and an electrode assembly are sealed in a shell, wherein: The shell includes a plurality of extension parts, and the plurality of extension parts are formed to protrude outward along the thickness direction of the battery core. The electrolyte is filled in the interior of the extended portion.

12. The battery cell according to claim 11, wherein: At least two of the plurality of extension portions are spaced apart from each other by a predetermined distance on one side of the housing.

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