Battery unit having venting gas discharge structure and device including same

Abstract

A battery unit according to an embodiment of the present invention comprises: a cell assembly including a plurality of battery cells; a frame for accommodating the cell assembly; and a heat-resistant sheet covering one side surface of the frame and having a venting part, wherein the venting part includes a trim portion and a parting line portion, and the trim portion has a higher venting gas opening level than the parting line portion.

Description

Battery unit having a venting gas discharge structure and device including the same

[0001] Cross-citation with related application(s)

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2025-0013758 dated February 4, 2025, and all contents disclosed in the document of said Korean patent application are incorporated herein as part of this specification.

[0003] The present invention relates to a battery unit and a device including the same, and more specifically, to a battery unit having a venting gas discharge structure and a device including the same.

[0004] Secondary batteries, which possess electrical characteristics such as high energy density and high applicability across product categories, are widely applied not only to portable devices but also to electric vehicles or hybrid vehicles powered by electric sources, and power storage devices. These secondary batteries are attracting attention as a new energy source for enhancing eco-friendliness and energy efficiency, not only for the primary advantage of drastically reducing the use of fossil fuels but also because they generate no by-products from energy use.

[0005] While small mobile devices use one or two or three battery cells per device, medium-to-large devices such as automobiles require high output and large capacity. Therefore, medium-to-large battery modules consisting of multiple battery cells electrically connected are used.

[0006] Meanwhile, with the recent increase in the need for large-capacity structures, including their utilization as energy storage sources, there is a growing demand for multi-module battery packs that combine multiple battery modules in which multiple secondary batteries are connected in series and / or parallel.

[0007] Meanwhile, when configuring a battery pack by connecting multiple battery cells in series or parallel, it is common practice to first construct a battery module consisting of at least one battery cell, and then use this at least one battery module to add other components to form the battery pack. Recently, modular-type battery module / pack structures are also being used, which omit the module frame constituting the battery module and directly load a cell assembly containing multiple battery cells onto a pack frame.

[0008] Battery units comprising such medium-to-large battery modules and / or battery packs are composed of rechargeable secondary batteries; therefore, these high-output, high-capacity secondary batteries generate a significant amount of heat during the charging and discharging process. If the heat generated by the battery module during the charging and discharging process is not effectively removed, heat accumulation occurs, which consequently accelerates the degradation of the battery module / battery pack and, in some cases, can lead to ignition or explosion.

[0009] Therefore, it is necessary to develop a method to smoothly discharge high-temperature gas when a thermal runaway phenomenon occurs within the battery unit.

[0010] The problem that the present invention aims to solve is to provide a battery unit and a device including the same for smooth venting gas discharge and prevention of backflow phenomena during thermal runaway of a battery.

[0011] However, the problems that the embodiments of the present invention aim to solve are not limited to the problems described above and can be expanded in various ways within the scope of the technical ideas included in the present invention.

[0012] A battery unit according to one embodiment of the present invention comprises a cell assembly including a plurality of battery cells, a frame housing the cell assembly, and a heat-resistant sheet covering one side of the frame and having a venting portion, wherein the venting portion includes a trim portion and a parting line portion, and the level of venting gas opening in the trim portion is higher than in the parting line portion.

[0013] One side of the above frame may have a venting hole formed to correspond to the venting portion.

[0014] The above venting holes are formed in multiple numbers, and the multiple venting holes may be spaced apart along the stacking direction of the battery cells.

[0015] The above venting section may have the trim area located at each of its two ends, and the parting line area located between the two trim areas.

[0016] The trim area above is a portion where the venting portion is cut in the shape of a cutting line, and the parting line area above may be a portion where the heat-resistant sheet is cut in the shape of a fracture line.

[0017] The trim area is an area where the venting gas generated in the battery cell is discharged to the outside, and the parting line area may be an area where the parting line area is torn due to pressure caused by the venting gas so that the venting gas is discharged to the outside.

[0018] The trim area above is a portion where the venting portion is cut in the shape of a cutting line, and the parting line area above may be a portion where the heat-resistant sheet is in a folded state.

[0019] The trim area is an area where the venting gas generated in the battery cell is discharged to the outside, and the parting line area may be an area where the parting line area is torn due to pressure caused by the venting gas so that the venting gas is discharged to the outside.

[0020] A plurality of the above-mentioned venting portions are formed, and the plurality of venting portions may be spaced apart and arranged along the stacking direction of the battery cell.

[0021] The above venting portion has a shape that extends long in the longitudinal direction of the battery cell, and the longitudinal direction of the battery cell may have a direction perpendicular to the stacking direction of the battery cell.

[0022] The plurality of venting sections may include a first venting section group formed at the front end of the cell assembly and a second venting section formed at the rear end of the cell assembly.

[0023] The heat-resistant sheet can be attached to one side of the frame.

[0024] A device according to another embodiment of the present invention includes the battery unit described above.

[0025] According to the embodiments, the novel heat-resistant sheet structure allows for the smooth discharge of venting gas and prevents the venting gas from entering adjacent battery cells where thermal runaway has occurred due to backflow.

[0026] The effects of the present invention are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art from the description in the claims.

[0027] FIG. 1 is a perspective view showing a battery unit according to one embodiment of the present invention.

[0028] Figure 2 is an exploded perspective view of the battery unit of Figure 1.

[0029] FIG. 3 is a perspective view of a battery cell included in the battery unit of FIG. 2.

[0030] FIG. 4 is a perspective view showing a structure in which a heat-resistant sheet is formed in the battery unit of FIG. 1.

[0031] FIG. 5 is a plan view showing a heat-resistant sheet according to one embodiment of the present invention.

[0032] Figure 6 is an enlarged view of one venting portion of the heat-resistant sheet of Figure 5.

[0033] FIG. 7 is a plan view showing a heat-resistant sheet according to another embodiment of the present invention.

[0034] FIG. 8 is a perspective view showing a battery unit according to a comparative example.

[0035] Hereinafter, various embodiments of the present invention are described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. The present invention may be embodied in various different forms other than those described below, and the scope of the present invention is not limited by the embodiments described herein.

[0036] To clearly explain the present invention, parts unrelated to the description have been omitted, and the same reference numerals are used for identical or similar components throughout the specification.

[0037] In addition, the size and thickness of each component shown in the drawings have been arbitrarily enlarged or reduced for convenience of explanation, so it is obvious that the content of the present invention is not limited to what is illustrated. In the drawings below, the thickness of each layer has been enlarged to clearly represent various layers and regions. Also, in the drawings below, the thickness of some layers and regions has been exaggerated for convenience of explanation.

[0038] Furthermore, when describing a part such as a layer, membrane, region, or plate as being "above" or "on" another part, this should be interpreted to include not only cases where the corresponding part is "directly above" the other part, but also cases where there is another part in between. Conversely, when describing a corresponding part such as a layer, membrane, region, or plate as being "directly above" another part, it may mean that there is no other part in between. Additionally, stating that a part is "above" or "on" a reference part means being located above or below the reference part, and does not necessarily mean being located "above" or "on" in the opposite direction of gravity. Meanwhile, just as describing a part as being "above" or "on" another part can be understood by referring to the aforementioned content, describing a part as being "below" or "under" another part can also be understood.

[0039] Furthermore, throughout the specification, when a part is described as "including" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0040] Additionally, throughout the specification, "planar" refers to the part as viewed from above, and "cross-sectional" refers to the cross-section of the part cut vertically as viewed from the side.

[0041] FIG. 1 is a perspective view showing a battery unit according to an embodiment of the present invention. FIG. 2 is an exploded perspective view of the battery unit of FIG. 1. FIG. 3 is a perspective view of a battery cell included in the battery unit of FIG. 2.

[0042] Referring to FIGS. 1 to 3, a battery unit (100) according to one embodiment of the present invention comprises: a cell assembly (120) in which a plurality of battery cells (110) are stacked, each cell having electrode leads (111, 112) protruding in opposite directions; a module frame (200), which is an example of a frame for housing the cell assembly (120); and a bus bar frame (310).

[0043] First, referring to FIG. 3, the battery cell (110) may be a pouch-type battery cell. For example, the battery cell (110) according to the present embodiment has a structure in which two electrode leads (111, 112) face each other and protrude from one end (114a) and the other end (114b) of the cell body (113). More specifically, the electrode leads (111, 112) are connected to an electrode assembly (not shown) and protrude from the electrode assembly (not shown) to the outside of the battery cell (110).

[0044] Meanwhile, the battery cell (110) can be manufactured by bonding the two ends (114a, 114b) of the cell case (114) and the one side (114c) connecting them, while the electrode assembly (not shown) is housed in the cell case (114). In other words, the battery cell (110) according to the present embodiment has a total of three sealing parts (114sa, 114sb, 114sc), and the sealing parts (114sa, 114sb, 114sc) are sealed by a method such as heat fusion, and the other side can be formed as a connecting part (115). The cell case (114) can be made of a laminate sheet including a resin layer and a metal layer.

[0045] Additionally, the connecting portion (115) may extend along one edge of the battery cell (110), and a protrusion (110p) of the battery cell (110), called a bat-ear, may be formed at the end of the connecting portion (115). Additionally, as the cell case (114) is sealed with the protruding electrode leads (111, 112) in between, a terrace portion (116) may be formed between the electrode leads (111, 112) and the cell body (113). That is, the battery cell (110) includes a terrace portion (116) that extends from the cell case (114) in the direction in which the electrode leads (111, 112) protrude.

[0046] Although the battery cell (110) according to the present embodiment has been described as being pouch-type, it is not limited thereto, and a prismatic cell or a cylindrical cell may also be used.

[0047] A plurality of battery cells (110) may be configured, and a plurality of battery cells (110) may be stacked to be electrically connected to each other to form a cell assembly (120). Referring to FIG. 2, battery cells (110) may be stacked along the y-axis direction to form a cell assembly (120). A first bus bar frame (310) may be located on one side of the cell assembly (120) in the direction in which the electrode lead (111) protrudes (x-axis direction). Although not specifically illustrated, a second bus bar frame may be located on the other side of the cell assembly (120) in the direction in which the electrode lead (112) protrudes (-x-axis direction). The cell assembly (120) and the first bus bar frame (310) may be accommodated together in a module frame (200). The module frame (200) may protect the cell assembly (120) and the electrical components connected thereto, which are accommodated inside the module frame (200), from external physical impact.

[0048] The module frame (200) according to an embodiment of the present invention may have a monoframe structure. First, the monoframe may be in the form of a metal plate in which the upper surface, lower surface, and both sides are integrated, and may be manufactured by extrusion molding. However, the structure of the module frame (200) is not limited thereto and may be a structure in which a U-shaped frame and an upper plate are combined. In the case of a structure in which a U-shaped frame and an upper plate are combined, the upper plate may be formed by combining the upper side of a U-shaped frame, which is a metal plate in which the lower surface and both sides are integrated or combined, and may be manufactured by press molding.

[0049] A thermally conductive resin may be injected between the lower surface of the cell assembly (120) and the module frame (200), and a thermally conductive resin layer (not shown) may be formed between the lower surface of the cell assembly (120) and the module frame (200) through the injected thermally conductive resin.

[0050] Meanwhile, the module frame (200) may be opened in the direction in which the electrode leads (111, 112) protrude (x-axis direction, -x-axis direction), and a first end plate (410) and a second end plate (420) may be positioned on each of the open sides of the module frame (200). The first end plate (410) may be joined to the module frame (200) while covering the first bus bar frame (310), and the second end plate (420) may be joined to the module frame (200) while covering the second bus bar frame (not shown). That is, the first bus bar frame (310) may be positioned between the first end plate (410) and the cell assembly (120), and the second bus bar frame (not shown) may be positioned between the second end plate (420) and the cell assembly (120). Additionally, an insulating cover (800, see FIG. 1) for electrical insulation may be located between the first end plate (410) and the first bus bar frame (310).

[0051] The first end plate (410) and the second end plate (420) are positioned to cover the one side and the other side of the cell assembly (120), respectively. The first end plate (410) and the second end plate (420) can protect the first bus bar frame (310) and various electrical components connected thereto from external impact, and for this purpose, they must have a certain strength and may include a metal such as aluminum. Additionally, the first end plate (410) and the second end plate (420) may each be joined to the corresponding corner of the module frame (200) by means such as welding.

[0052] The first bus bar frame (310) is positioned on one side of the cell assembly (120) to cover the cell assembly (120) and simultaneously guide the connection between the cell assembly (120) and an external device. Specifically, at least one of a bus bar, a terminal bus bar, and a module connector may be mounted on the first bus bar frame (310). In particular, at least one of a bus bar, a terminal bus bar, and a module connector may be mounted on the side opposite to the side of the first bus bar frame (310) facing the cell assembly (120). For example, FIG. 2 shows a bus bar (510) and a terminal bus bar (520) mounted on the first bus bar frame (310).

[0053] Battery cells (110) constituting the cell assembly (120) can be connected in series or in parallel by a bus bar (510) or a terminal bus bar (520), and the battery cells (110) can be electrically connected to an external device or circuit through a terminal bus bar (520) exposed to the outside of the battery unit (100). For example, the terminal bus bar (520) can be connected to an external bus bar that allows the battery unit containing the terminal bus bar (520) to be connected to another battery unit adjacent to it.

[0054] The first bus bar frame (310) may include an electrically insulating material. The first bus bar frame (310) may prevent a short circuit by restricting the bus bar (510) or terminal bus bar (520) from contacting the battery cells (110), except for the portion where the bus bar (510) or terminal bus bar (520) is joined to the electrode lead (111).

[0055] Meanwhile, as described above, a second bus bar frame may be positioned on the other side of the cell assembly (120), and a bus bar and a module connector may be mounted on the second bus bar frame. An electrode lead (112) may be connected to this bus bar.

[0056] An opening may be formed in the first end plate (410) according to the present embodiment to expose a terminal bus bar (520). The opening may be a terminal bus bar opening. For example, as shown in FIGS. 1 and 2, a terminal bus bar opening (410H) to expose a terminal bus bar (520) may be formed in the first end plate (410). The terminal bus bar (520) further includes an upwardly protruding portion compared to the bus bar (510), and this upwardly protruding portion may be exposed to the outside of the battery unit (100) through the terminal bus bar opening (410H). The terminal bus bar (520) exposed through the terminal bus bar opening (410H) may be connected to another battery unit or a BDU (Battery Disconnect Unit) to form a High Voltage (HV) connection.

[0057] The battery unit (100) according to the embodiment described above is described based on the battery module. In the battery unit according to the embodiment, a venting hole (210) may be formed on the upper surface of the module frame (200) as an example of one side of the module frame (200). As shown in FIGS. 1 and 2, the venting hole (210) may be an elliptical shape extending along the length direction (x-axis direction) of the battery cell (110), and may have a structure in which the inside of the ellipse is open.

[0058] A plurality of venting holes (210) may be formed along the direction (y-axis direction) in which the battery cells (110) included in the cell assembly (120) are stacked. The plurality of venting holes (210) may include a first group of venting holes formed in an area that overlaps vertically with the front end of the cell assembly (120) and a second group of venting holes formed in an area that overlaps vertically with the rear end of the cell assembly (120).

[0059] FIG. 4 is a perspective view showing a structure in which a heat-resistant sheet is formed in the battery unit of FIG. 1. FIG. 5 is a plan view showing a heat-resistant sheet according to an embodiment of the present invention. FIG. 6 is an enlarged view showing one venting portion of the heat-resistant sheet of FIG. 5.

[0060] Referring to FIGS. 1, 2 and 4, the battery unit (100) according to the present embodiment includes a heat-resistant sheet (900) having a venting portion (910) and covering the upper surface of the module frame (200). At this time, the heat-resistant sheet (900) may be attached to the upper surface of the module frame (200). The heat-resistant sheet (900) may be an insulating sheet.

[0061] The venting portion (910) according to the present embodiment may correspond to the venting hole (210) described in FIG. 1. For example, the venting portion (910) may be an elliptical shape extending along the length direction (x-axis direction) of the battery cell (110) as shown in FIG. 5, and the elliptical structure of the venting portion (910) may have substantially the same size as the open portion where the venting hole (210) of FIG. 1 is formed. The length direction (x-axis direction) of the battery cell (110) may have a direction substantially perpendicular to the stacking direction (y-axis direction) of the battery cell (110).

[0062] A plurality of venting sections (910) may be formed, and the plurality of venting sections (910) may be spaced apart along the stacking direction (y-axis direction) of the battery cell (110). At this time, the plurality of venting sections (910) may include a first group of venting sections formed in an area that overlaps vertically with the front end of the cell assembly (120) and a second group of venting sections formed in an area that overlaps vertically with the rear end of the cell assembly (120). Accordingly, the first group of venting holes (210) described above and the first group of venting sections (910) may be matched with each other in a vertically overlapping structure, and the second group of venting holes (210) and the second group of venting sections (910) may also be matched with each other in a vertically overlapping structure.

[0063] As illustrated in FIGS. 5 and 6, the venting portion (910) according to the present embodiment may include a trim portion (910a) and a parting line portion (910b). According to the present embodiment, the venting gas opening level of the trim portion (910a) may be higher than the venting gas opening level of the parting line portion (910b). The trim portion (910a) is a portion of the venting portion (910) that is cut in the shape of a cutting line (915), and the parting line portion (910b) may be a portion of the heat-resistant sheet (900) that is cut in the shape of a break line (920). The cutting line shape (915) may be a state in which there is a gap inside and outside the heat-resistant sheet (900), and the break line shape (920) may be a state in which there is a gap inside and outside the heat-resistant sheet (900) in the shape of a dotted line.

[0064] For example, as shown in FIG. 6, the venting section (910) according to the present embodiment may have trim areas (910a) located at each end and a parting line area (910b) located between the two trim areas (910a). In this case, the trim area (910a) may have a “Y” shape to facilitate the discharge of venting gas.

[0065] According to the present embodiment, the trim area (910a) is an area where the venting gas generated in the battery cell (110) is discharged to the outside of the battery unit (100), and the parting line area (910b) may be an area where the parting line area (910b) is torn due to the pressure caused by the venting gas, thereby allowing the venting gas to be discharged to the outside of the battery unit (100). In FIG. 5, assuming that thermal runaway begins in the battery cell (110) located below the leftmost venting section (910), the venting gas may first be discharged to the trim area (910a), where venting gas discharge is relatively easy, due to the venting gas pressure inside the battery unit (100). At the same time, as pressure is applied to section A indicated in FIG. 6, the parting line area (910b) adjacent to section A is gradually torn. Therefore, by discharging the venting gas from most of the venting section (910), smooth venting gas discharge can be achieved.

[0066] Even if the heat-resistant sheet (900) is damaged in the leftmost venting section (910) in Fig. 5 and the venting gas is smoothly discharged, the parting line area (910b) still largely exists in the heat-resistant sheet (900) that overlaps the upper and lower parts of the remaining battery cell (110), so the backflow of venting gas caused by thermal runaway of the leftmost battery cell (110) and damage to other battery cells (110) can be minimized.

[0067] In this way, according to the present embodiment, venting gas caused by thermal runaway generated inside the battery unit (100) can be smoothly discharged, and at the same time, damage to neighboring battery cells (110) due to backflow can be minimized.

[0068] FIG. 7 is a plan view showing a heat-resistant sheet according to another embodiment of the present invention.

[0069] Referring to FIG. 7, the venting portion (960) formed in the heat-resistant sheet (950) according to the present embodiment may include a trim area and a parting line area. In the present embodiment, the trim area is a portion where the venting portion (960) is cut in the shape of a cutting line (965) that forms a gap inside and outside the heat-resistant sheet (950), and the parting line area may be a portion where the heat-resistant sheet (950) has a folded state (970). Aside from these differences, the heat-resistant sheet (950) according to the present embodiment is identical to the heat-resistant sheet (900) described in FIG. 5.

[0070] FIG. 8 is a perspective view showing a battery unit according to a comparative example.

[0071] Referring to FIG. 8, the battery unit (10) according to the comparative example includes a heat-resistant sheet (90) covering the upper surface of the module frame (20). A plurality of venting portions (91) are formed in the heat-resistant sheet (90), and the venting portions (91) according to the comparative example can be cut in the shape of a cutting line, such that the portions corresponding to the trim area and the parting line area of ​​the venting portion (910) according to the present embodiment of FIG. 5 are all cut.

[0072] According to a comparative example, although venting gas can be smoothly discharged from a battery cell in which thermal runaway has occurred, the venting gas may flow back through a venting section that overlaps vertically with the remaining battery cells, thereby damaging the battery cell adjacent to the battery cell in which thermal runaway has occurred. In contrast, a battery unit according to an embodiment of the present invention can smoothly discharge venting gas while simultaneously minimizing damage to the remaining battery cells adjacent to the battery cell in which thermal runaway has occurred due to backflow.

[0073] Meanwhile, one or more battery modules included in the battery unit according to the present embodiment may be packaged within a pack case to form a battery pack.

[0074] The battery module and the battery pack containing the same described above can be applied to various devices. Such devices may be applied to means of transportation such as electric bicycles, electric vehicles, and hybrid vehicles, but the present invention is not limited thereto and can be applied to various devices capable of using the battery module and the battery pack containing the same, and this also falls within the scope of the present invention.

[0075] The battery module or battery pack described in this specification may be included in a battery unit.

[0076] Although preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concept of the present invention as defined in the following claims also fall within the scope of the present invention.

[0077] [Explanation of the symbol]

[0078] 100: Battery unit

[0079] 200: Module Frame

[0080] 900, 950: Heat-resistant sheet

[0081] 915, 965: Cutting line shape

[0082] 920: Break line shape

[0083] 960: Venting section

[0084] 970: Folded state

Claims

1. A cell assembly comprising a plurality of battery cells, A frame housing the above cell assembly, and It includes a heat-resistant sheet covering one side of the above frame and having a venting portion, The above venting portion includes a trim portion and a parting line portion, and A battery unit in which the above trim area has a higher venting gas opening level than the above parting line area.

2. In Paragraph 1, A battery unit having a venting hole formed on one side of the above frame to correspond to the venting portion.

3. In Paragraph 2, The above venting holes are formed in multiple numbers, and The above plurality of venting holes are spaced apart and arranged along the stacking direction of the battery cells in a battery unit.

4. In Paragraph 1, The above venting section is a battery unit in which the trim area is located at each of the two ends, and the parting line area is located between the two trim areas.

5. In Paragraph 1, A battery unit in which the trim area is a portion in which the venting portion is cut in the shape of a cutting line, and the parting line area is a portion in which the heat-resistant sheet is cut in the shape of a fracture line.

6. In Paragraph 5, A battery unit in which the trim area is an area where the venting gas generated in the battery cell is discharged to the outside, and the parting line area is an area where the parting line area is torn due to the pressure caused by the venting gas, thereby allowing the venting gas to be discharged to the outside.

7. In Paragraph 4, A battery unit in which the trim area is a portion in which the venting portion is cut in the shape of a cutting line, and the parting line area is a portion in which the heat-resistant sheet is in a folded state.

8. In Paragraph 7, A battery unit in which the trim area is an area where the venting gas generated in the battery cell is discharged to the outside, and the parting line area is an area where the parting line area is torn due to the pressure caused by the venting gas, thereby allowing the venting gas to be discharged to the outside.

9. In Paragraph 1, A plurality of the above venting sections are formed, and The above plurality of venting sections are spaced apart along the stacking direction of the battery cells and are arranged in a battery unit.

10. In Paragraph 9, The above venting portion has a shape that extends long in the longitudinal direction of the battery cell, and A battery unit having a longitudinal direction of the above battery cell perpendicular to the stacking direction of the above battery cell.

11. In Paragraph 9, A battery unit comprising a plurality of venting sections, a first venting section group formed at the front end of the cell assembly, and a second venting section formed at the rear end of the cell assembly.

12. In Paragraph 1, The above heat-resistant sheet is a battery unit attached to one side of the above frame.

13. A device comprising a battery unit according to paragraph 1.

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