Cell assembly and battery pack comprising same

Abstract

The present invention relates to a cell assembly and a battery pack comprising same, the cell assembly comprising: a cell block including a plurality of battery cells; protective covers, each being coupled to the front and the rear of the cell block; and a module frame coupled to the protective covers while encompassing the periphery of the cell block such that the cell block is sealed, wherein the module frame includes at least one melting recess at the top thereof.

Description

Cell assembly and battery pack including the same

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

[0002] The present disclosure claims the benefit of priority based on Korean Patent Application No. 10-2024-0193616 filed December 23, 2024, and all contents of Korean Patent Application No. 10-2024-0193616 are incorporated by reference into the present disclosure.

[0003] Generally, a battery cell consists of an electrode assembly in which electrodes and separators are alternately stacked, an electrode lead coupled to the electrode of the electrode assembly, a case in which the electrode lead is exposed to the outside and which encloses the electrode assembly, and an electrolyte filled together with the electrode assembly inside the case.

[0004] The above battery cells can be broadly classified into cylindrical cells, pouch-type cells, and prismatic cells depending on the shape of the case.

[0005] Meanwhile, while battery cells may be used individually, they are generally configured such that multiple battery cells are electrically connected in series and / or parallel. In particular, multiple battery cells are electrically connected to form a single cell block. Additionally, the cell block can be housed inside a module frame to form a single cell assembly.

[0006] FIG. 1 is an exploded perspective view and a perspective view of a conventional cell assembly in which a battery cell (20) is housed.

[0007] A cell assembly that accommodates the above battery cell (20) may have a protective cover (30) attached to the front and rear surfaces of the cell block (40).

[0008] Accordingly, the cell block (40) can be protected while being isolated from the outside by the module frame (10) and the protective cover (30).

[0009] The module frame (10) surrounding the cell block (40) is made of a metal material to effectively dissipate heat from the cell block (40).

[0010] This type of sealing structure can protect the internal cell block (40) from external impact and flames.

[0011] However, when high-temperature gas is generated in the internal cell block (40), such a cell assembly may fail to effectively release the gas, leading to thermal runaway. At this time, due to a rapid increase in gas pressure, the thermally runaway cell assembly is at high risk of exploding.

[0012] In the case of conventional battery packs, such cell assemblies are housed in a single space, and if an explosion occurs in one cell assembly, the impact may cause a chain reaction of explosions in adjacent cell assemblies.

[0013] Accordingly, the present invention is devised to solve the above-mentioned problems and aims to provide a cell assembly with a structure capable of effectively suppressing thermal runaway to improve safety, and a battery pack including the same.

[0014] Other objects and advantages of the present invention may be understood from the following description and will become more clearly apparent from the embodiments of the present invention. Furthermore, it will be readily apparent that the objects and advantages of the present invention can be realized by the means and combinations thereof set forth in the claims.

[0015] According to the present invention, a cell assembly is provided comprising: a cell block including a plurality of battery cells; a protective cover coupled to the front and rear of the cell block, respectively; and a module frame that wraps around the perimeter of the cell block to seal the cell block and is coupled to the protective cover, wherein the module frame includes at least one melting groove on its upper surface.

[0016] An upper protective coating layer resistant to heat and flame may be provided on the outer surface of the above module frame.

[0017] The inner surface of the module frame may be provided with a lower protective coating layer that is resistant to heat and flame.

[0018] The above lower protective coating layer may be provided only in the area excluding the melting groove.

[0019] The module frame comprises: a bottom support member supporting the lower part of the cell block; a pair of side support members extending upward from both ends of the bottom support member to support the side part of the cell block; and a cover member with both ends respectively coupled to the side support members to face the bottom support member to cover the upper part of the cell block, and the melting groove may be formed in the lower part of the cover member.

[0020] The melting groove may include a bottom portion formed at a certain depth in the thickness direction of the cover portion.

[0021] In the above cover portion, the ratio of the thickness of the bottom portion of the melting groove to the thickness of the area excluding the melting groove may be 0.1:1 to 0.8:1.

[0022] The shape of the rim of the bottom portion above may be either a circular or a polygonal shape.

[0023] The above bottom portion may have a flat shape.

[0024] The above bottom portion may have an inclined surface formed such that the thickness becomes thinner towards the center.

[0025] The melting groove can be formed to a certain depth in the thickness direction of the cover portion from the edge of the bottom portion.

[0026] The above bottom portion may include: a first bottom portion; and a second bottom portion formed to a certain depth in the thickness direction of the cover portion at the edge of the first bottom portion and continuously formed along the edge of the first bottom portion.

[0027] The second bottom portion may be formed to be spaced apart from the edge of the first bottom portion by a predetermined distance.

[0028] According to the present invention, a battery pack is provided that accommodates at least one cell assembly.

[0029] The battery pack comprises: a pack case on which the cell assembly is seated; and an upper case coupled to the pack case to cover the upper part of the cell assembly.

[0030] According to the present invention, the phenomenon of a cell assembly exploding can be suppressed.

[0031] In addition, in a battery pack accommodating multiple cell assemblies, even if one cell assembly undergoes thermal runaway, the phenomenon of flames and high-temperature gases invading other adjacent cell assemblies can be suppressed.

[0032] FIG. 1 is an exploded perspective view and a perspective view of a conventional cell assembly.

[0033] FIG. 2 is a perspective view of a cell assembly according to a first embodiment of the present invention.

[0034] Figure 3 is a bottom perspective view of the cover portion included in the cell assembly of Figure 2.

[0035] Figure 4 is a cross-sectional view of the cell assembly of Figure 2.

[0036] Figure 5 is a schematic diagram briefly illustrating the thermal runaway situation of a cell block.

[0037] FIG. 6 is a cross-sectional view of a modified example of the cell assembly of FIG. 2.

[0038] FIG. 7 is a cross-sectional view of another variation of the cell assembly of FIG. 2.

[0039] FIG. 8 is a cross-sectional view of a melting groove included in a cell assembly according to a second embodiment of the present invention.

[0040] Fig. 9 is a cross-sectional perspective view of the melting groove of Fig. 8.

[0041] FIG. 10 is a cross-sectional view of a melting groove included in a cell assembly according to a third embodiment of the present invention.

[0042] FIG. 11 is a cross-sectional perspective view of the melting groove of FIG. 10.

[0043] FIG. 12 is a cross-sectional view of a melting groove included in a cell assembly according to a fourth embodiment of the present invention.

[0044] FIG. 13 is a cross-sectional perspective view of the melting groove of FIG. 12.

[0045] FIG. 14 is a perspective view of the battery pack of the present invention.

[0046] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, and should be interpreted in a meaning and concept consistent with the technical spirit of the present invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention.

[0047] Therefore, 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 of the technical ideas of the present invention; thus, it should be understood that various equivalents and modifications that can replace them may exist at the time of filing this application.

[0048] In addition, in describing the present invention, if it is determined that a detailed description of related known components or functions may obscure the essence of the invention, such detailed description is omitted.

[0049] Since embodiments of the present invention are provided to more fully explain the invention to those skilled in the art, the shapes and sizes of the components in the drawings may be exaggerated, omitted, or schematically depicted for clearer explanation. Accordingly, the size or proportion of each component does not entirely reflect the actual size or proportion.

[0050] In describing each drawing, similar reference numerals have been used for similar components. In the attached drawings, the dimensions of the structures are depicted enlarged from their actual size for the clarity of the invention. The terms used to describe the various components are for illustrative purposes only and should not limit the components. The terms are used solely for the purpose of distinguishing one component from another. For example, without departing from the scope of the invention, a first component may be named a second component, and similarly, a second component may be named a first component. A singular expression includes a plural expression unless the context clearly indicates otherwise.

[0051]

[0052] Terms such as "comprising" or "having," as used throughout the specification of the present invention, 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.

[0053] Furthermore, when a part such as a layer, film, region, or plate is described as being "on" another part, this includes not only cases where it is "immediately above" the other part, but also cases where there is another part in between. Conversely, when a part such as a layer, film, region, or plate is described as being "under" another part, this includes not only cases where it is "immediately below" the other part, but also cases where there is another part in between. Additionally, in the specification of the present invention, being "placed on" may include cases where it is placed on the lower part as well as the upper part.

[0054]

[0055] The present invention relates to a cell assembly and a battery pack including the same, wherein the cell assembly of the present invention is characterized by including a plurality of melting grooves on its upper surface.

[0056] FIGS. 1 to 7 relate to a cell assembly according to a first embodiment of the present invention, FIGS. 8 to 9 relate to a cell assembly according to a second embodiment of the present invention, FIGS. 10 to 11 relate to a cell assembly according to a third embodiment of the present invention, FIGS. 12 to 13 relate to a cell assembly according to a fourth embodiment of the present invention, and FIG. 14 relates to a battery pack of the present invention.

[0057] Hereinafter, specific embodiments of the cell assembly of the present invention and a battery pack including the same will be described in detail with reference to the attached drawings. For reference, the directions of front, back, up, down, left, and right used to specify relative positions in the following description are intended to aid in understanding the invention, and unless otherwise specifically defined, the directions shown in the drawings are used as the reference.

[0058] (Additionally, the length direction of a configuration is defined as the direction corresponding to the side having the longest length of the configuration shown in the drawing with respect to the horizontal direction, and the width direction of a configuration is defined as the direction perpendicular to the length direction with respect to the horizontal direction.)

[0059]

[0060] In the present invention, the width direction of the cell assembly is defined as the direction in which the battery cells are stacked, and the length direction of the cell assembly is defined as the direction perpendicular to the width direction of the cell assembly.

[0061] Additionally, the width direction of the battery pack refers to the length direction of the cell assembly accommodated in the battery pack, and the length direction of the battery pack refers to the width direction of the cell assembly accommodated in the battery pack.

[0062]

[0063] Cell assembly (100)

[0064] (First embodiment)

[0065] FIG. 2 is a perspective view of a cell assembly (100) according to a first embodiment of the present invention, FIG. 3 is a bottom perspective view of a cover portion (133) included in the cell assembly (100) of FIG. 2, and FIG. 4 is a cross-sectional view of the cell assembly (100) of FIG. 2.

[0066] The cell assembly (100) of the present invention includes a cell block comprising a plurality of battery cells as shown in FIGS. 2 to 4, a protective cover (120) that is respectively coupled to the front and rear of the cell block, and a module frame (130) that wraps around the perimeter of the cell block to seal the cell block and is coupled to the protective cover (120).

[0067]

[0068] The cell block is protected from the outside by a pair of protective covers (120) and a module frame (130) that surrounds the cell block and is coupled to the protective covers (120).

[0069] The cell assembly (100) is characterized by including at least one melting groove (G) on the upper part of the module frame (130).

[0070] The module frame (130) includes a bottom support (131) that supports the lower part of the cell block, a pair of side support parts (132) that support the sides of the cell block, and a cover part (133) that covers the upper part of the cell block.

[0071] The above pair of side support members (132) are formed to extend upward from both ends of the bottom support member (131).

[0072] The above cover portion (133) has both ends connected to the side support portion (132) respectively so as to face the bottom support portion (131).

[0073] The melting groove (G) is formed in the lower part of the cover portion (133) as shown in FIG. 3.

[0074] The melting groove (G) formed at the lower part of the cover portion (133) includes a bottom portion (B) formed at a certain depth in the thickness direction of the cover portion (133).

[0075] The shape of the bottom portion (B) is not particularly limited. For example, the bottom portion (B) may be circular or polygonal.

[0076] The bottom portion (B) can be formed in a flat shape as shown in FIGS. 3 and FIGS. 4.

[0077] The cell assembly (100) of the present invention is formed such that the thickness (h1) of the bottom portion (B) is thin.

[0078] In the above cover portion (133), the thickness (h1) of the bottom portion (B) of the melting groove (G) is formed to be thinner than the thickness (h2) of the area excluding the melting groove (G).

[0079] If the thickness (h1) of the bottom portion (B) is thin, the melting groove (G) portion may first melt or break and open as the cover portion (133) comes into contact with external flames and high-temperature heat. The formation of such an opening can suppress a larger explosion by reducing the internal pressure of the cell assembly (100).

[0080] Specifically, the ratio of the thickness (h1) of the bottom portion (B) of the melting groove (G) to the thickness (h2) of the area excluding the melting groove (G) is 0.1:1 to 0.8:1.

[0081]

[0082] Figure 5 is a schematic diagram briefly illustrating the thermal runaway situation of a cell block.

[0083] More specifically, FIG. 5 simply shows the direction of movement (D) of high-temperature gas and flame when they are generated inside the cell assembly (100).

[0084] As the cell block contained within the cell assembly (100) of the present invention overheats, high-temperature gas and flames, etc., may be generated as shown in FIG. 5.

[0085] At this time, the high-temperature gas can increase the pressure inside the cell assembly (100), and as the bottom part (B) of the melting groove (G) is damaged first by the heat, the gas and flames can quickly escape to the top of the cell assembly (100).

[0086]

[0087] The cell assembly (100) of the present invention may have a protective coating layer formed on the surface of the module frame (130) that is resistant to heat and flame.

[0088] The above protective coating layer may be provided on the surface of the module frame (130) by applying a functional binder having at least one of flame retardancy, flame resistance, and non-combustibility, or may be provided on the surface of the module frame (130) by attaching a functional sheet containing a material having at least one of flame retardancy, flame resistance, and non-combustibility to the surface of the module frame (130).

[0089] The above protective coating layer may be at least one of an upper protective coating layer (400a) provided on the outer surface of the module frame (130) and a lower protective coating layer (400b) provided on the inner surface of the module frame (130).

[0090] FIG. 6 is a cross-sectional view of a modified example of the cell assembly (100) of FIG. 2.

[0091] The lower protective coating layer (400b) is provided on the lower part of the cover portion (133) as shown in FIG. 6.

[0092] Preferably, the lower protective coating layer (400b) is provided only in the area excluding the melting groove (G) at the bottom of the cover portion (133). Therefore, if high-temperature gas and flames are generated due to the ignition of the cell block, the melting groove (G) area excluding the part where the lower protective coating layer (400b) is formed can be damaged and opened more quickly.

[0093] Unlike the lower protective coating layer (400b), the upper protective coating layer (400a) is provided over the entire upper portion of the cover portion (133). The upper protective coating layer (400a) can prevent the cover portion (133) from being damaged when the cell assembly (100) comes into contact with external high-temperature gas and flames.

[0094]

[0095] FIG. 7 is a cross-sectional view of another variation of the cell assembly (100) of FIG. 2.

[0096] The upper protective coating layer (400a) and the lower protective coating layer (400b) are provided to face each other with the cover portion (133) in between.

[0097] Preferably, the lower protective coating layer (400b) is provided only in the area excluding the melting groove (G) at the bottom of the cover portion (133), and the upper protective coating layer (400a) is provided over the entire top of the cover portion (133). Accordingly, if high-temperature gas and flames are generated due to the ignition of the cell block, the melting groove (G) area, excluding the part where the lower protective coating layer (400b) is formed, can be rapidly damaged and opened. Conversely, when the cell assembly (100) comes into contact with high-temperature gas and flames generated from the outside, the upper protective coating layer (400a) can prevent damage to the cover portion (133).

[0098]

[0099] Due to the configuration of the melting groove (G), the cell assembly (100) of the present invention can prevent a large explosion even if the contained cell block undergoes thermal runaway and high-temperature gas and flames are generated, by causing damage to the melting groove (G).

[0100]

[0101] (Second embodiment)

[0102] FIG. 8 is a cross-sectional view of a melting groove (G) included in a cell assembly (100) according to a second embodiment of the present invention, and FIG. 9 is a cross-sectional perspective view of the melting groove (G) of FIG. 8.

[0103] The melting groove (G) included in the cell assembly (100) according to the second embodiment has a structure in which the thickness is reduced in a double manner by forming a step on the bottom portion (B) as shown in FIGS. 8 and 9.

[0104] The above bottom portion (B) includes a first bottom portion (B1) and a second bottom portion (B2) formed to have a thinner thickness than the first bottom portion (B1) and a step difference with respect to the first bottom portion (B1).

[0105] Specifically, the second bottom portion (B2) is formed at a certain depth in the thickness direction of the cover portion (133) from the edge of the first bottom portion (B1) and is formed continuously along the edge of the first bottom portion (B1). For example, if the first bottom portion (B1) is circular, the second bottom portion (B2) is formed in the shape of a circular ring.

[0106] Based on the thickness direction of the cover portion (133), the ratio of the thickness of the first bottom portion (B1) and the thickness of the area excluding the melting groove (G) is 0.3:1 to 0.8:1.

[0107] In addition, the ratio of the thickness of the second bottom portion (B2) and the thickness of the area excluding the melting groove (G) is 0.1:1 to 0.7:1.

[0108] If the bottom portion (B) of the melting groove (G) is formed to have a step, damage may selectively occur within the second bottom portion (B2), which has a relatively thin thickness.

[0109]

[0110] (Third embodiment)

[0111] FIG. 10 is a cross-sectional view of a melting groove (G) included in a cell assembly (100) according to a third embodiment of the present invention, and FIG. 11 is a cross-sectional perspective view of the melting groove (G) of FIG. 10.

[0112] The bottom portion (B) of the cell assembly (100) according to the third embodiment is formed with an inclined surface such that the thickness becomes thinner toward the center, as shown in FIGS. 10 and 11.

[0113] That is, the thickness of the melting groove (G) becomes thinner towards the center.

[0114] Therefore, if high-temperature gas and flames are generated inside the cell assembly (100), damage to the center of the melting groove (G) may occur first.

[0115]

[0116] (Fourth embodiment)

[0117] FIG. 12 is a cross-sectional view of a melting groove (G) included in a cell assembly (100) according to a fourth embodiment of the present invention, and FIG. 13 is a cross-sectional perspective view of the melting groove (G) of FIG. 12.

[0118] The melting groove (G) included in the cell assembly (100) according to the fourth embodiment has a structure in which the thickness is reduced in a double manner by forming a step on the bottom portion (B) as shown in FIGS. 12 and 13.

[0119] The above bottom portion (B) includes a first bottom portion (B1) and a second bottom portion (B2) formed to have a thinner thickness than the first bottom portion (B1) and a step difference with respect to the first bottom portion (B1).

[0120] Specifically, the second bottom portion (B2) is formed at a predetermined distance from the edge of the first bottom portion (B1) to a certain depth in the thickness direction of the cover portion (133), and is formed continuously along the edge of the first bottom portion (B1). For example, if the first bottom portion (B1) is circular, the second bottom portion (B2) is formed in the shape of a circular ring.

[0121] Based on the thickness direction of the cover portion (133), the ratio of the thickness of the first bottom portion (B1) and the thickness of the area excluding the melting groove (G) is 0.3:1 to 0.8:1.

[0122] In addition, the ratio of the thickness of the second bottom portion (B2) and the thickness of the area excluding the melting groove (G) is 0.1:1 to 0.7:1.

[0123] If the bottom portion (B) of the melting groove (G) is formed to have a step, damage may selectively occur within the second bottom portion (B2), which has a relatively thin thickness.

[0124]

[0125] Battery pack (1000)

[0126] FIG. 14 is a perspective view of the battery pack (1000) of the present invention.

[0127] The battery pack (1000) of the present invention accommodates at least one cell assembly (100) including a melting groove (G) on the top as shown in FIG. 14.

[0128] The battery pack (1000) includes a pack case (200) on which a cell assembly (100) is seated, and an upper case (300) coupled to the pack case (200) to cover the upper part of the cell assembly (100).

[0129] A plurality of cell assemblies (100) are inserted into the above pack case (200) so as to be seated, as shown in FIG. 14.

[0130] The above pack case (200) and upper case (300) are combined to surround the internal cell assembly (100) so that it can be protected from external impacts, etc.

[0131] Each of the above cell assemblies (100) can share an internal space formed by the combination of the pack case (200) and the upper case (300).

[0132] The battery pack (1000) of the present invention can suppress the rapid transfer of heat and flames due to the configuration of the cover portion (133) of another cell assembly (100) even if one of the cell assemblies (100) among the accommodated cell assemblies (100) undergoes thermal runaway and high-temperature gas and flames are ejected through the melting groove (G).

[0133]

[0134] The present invention has been described in more detail above through drawings and embodiments. However, the configurations described in the drawings or embodiments described in this specification are merely one embodiment of the present invention and do not represent all technical concepts of the present invention; therefore, it should be understood that various equivalents and modifications that can replace them may exist at the time of filing this application.

[0135]

[0136] [Explanation of the symbol]

[0137] 10: (Prior Art) Module Frame

[0138] 20: (Prior Art) Battery Cell

[0139] 30: (Prior art) Protective cover

[0140] 40: (Prior Art) Cell Block

[0141] 1000: Battery pack

[0142] 100: Cell assembly

[0143] 120: Protective cover

[0144] 130: Module Frame

[0145] 131: Floor support

[0146] 132: Side support

[0147] 133: Cover part

[0148] 200: Pack case

[0149] 300: Upper case

[0150] 400a: Upper protective coating layer

[0151] 400b: Lower protective coating layer

[0152] G: Melting Home

[0153] B: Bottom part

[0154] B1: 1st floor section

[0155] B2: Second bottom part

[0156] D: Gas and flame movement (direction)

Claims

1. A cell block comprising a plurality of battery cells; Protective covers coupled to the front and rear of the cell block, respectively; and A module frame that wraps around the perimeter of the cell block to seal the cell block and is coupled with the protective cover; comprising A cell assembly characterized in that the above module frame includes at least one melting groove on the upper side.

2. In Paragraph 1, A cell assembly provided with an upper protective coating layer having resistance to heat and flame on the outer surface of the module frame.

3. In Paragraph 1, A cell assembly provided with a lower protective coating layer having resistance to heat and flame on the inner surface of the module frame.

4. In Paragraph 3, The cell assembly provided with the lower protective coating layer only in the area excluding the melting groove.

5. In Paragraph 1, The above module frame is, A bottom support member that supports the lower part of the cell block above; A pair of side supports extending upward from both ends of the floor support to support the sides of the cell block; and A cover portion covering the upper part of the cell block, wherein both ends are respectively connected to the side support portions so as to face the floor support portion; The above melting groove is a cell assembly formed at the lower part of the above cover.

6. In Paragraph 5, The above melting groove comprises a bottom portion formed at a certain depth in the thickness direction of the cover portion; a cell assembly.

7. In Paragraph 6, A cell assembly in which, in the above cover portion, the ratio of the thickness of the bottom portion of the melting groove to the thickness of the area excluding the melting groove is 0.1:1 to 0.8:

1.

8. In Paragraph 6, The rim shape of the bottom portion above is a cell assembly that is either a circular or a polygonal shape.

9. In Paragraph 6, The above bottom portion is a cell assembly having a flat shape.

10. In Paragraph 6, The above-mentioned bottom portion is a cell assembly having an inclined surface formed such that the thickness decreases towards the center.

11. In Paragraph 6, The above melting groove is a cell assembly formed to a certain depth in the thickness direction of the cover portion from the edge of the bottom portion.

12. In Paragraph 6, The above bottom part is, 1st bottom part; and A cell assembly comprising: a second bottom portion formed to a certain depth in the thickness direction of the cover portion at the edge of the first bottom portion and continuously formed along the edge of the first bottom portion.

13. In Paragraph 12, The above second bottom portion is a cell assembly formed to be spaced apart from the edge of the above first bottom portion by a predetermined distance.

14. A battery pack accommodating at least one cell assembly according to paragraph 1, A pack case on which the above cell assembly is seated; and A battery pack comprising: an upper case coupled to the pack case to cover the upper part of the cell assembly.

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