Battery pack and battery assembly including this battery pack

Abstract

The invention relates to a battery pack and a battery assembly comprising such a pack. The battery pack, according to a particular scheme of the invention, comprises: battery cells stacked along one direction; cell frames extending along the respective edges of the battery cells and covering the edges of the battery cells; and a heat sink having at least one cooling plate arranged at least at one location between the battery cells. The cell vent is made at the part corresponding to the lower end of the battery cell in the cell frame.

Description

Battery assembly and battery pack including same

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

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2024-0035066, filed March 13, 2024, and Korean Patent Application No. 10-2024-0197353, filed December 26, 2024, the entire contents of which are incorporated herein by reference.

[0003] The present invention relates to a battery assembly and a battery pack including the same, and more particularly, to a battery assembly capable of minimizing thermal runaway transition and preventing structural collapse, and a battery pack including the same.

[0004] In modern society, the widespread use of portable devices like cell phones, laptops, camcorders, and digital cameras has fueled active development of technologies related to these devices. Furthermore, rechargeable secondary batteries are increasingly being used as power sources for electric vehicles (EVs), hybrid electric vehicles (HEVs), and plug-in hybrid electric vehicles (P-HEVs) to address air pollution caused by conventional gasoline-powered vehicles. This, in turn, heightens the need for further development of these batteries.

[0005] Currently commercialized secondary batteries include nickel cadmium batteries, nickel hydrogen batteries, nickel zinc batteries, and lithium secondary batteries. Among these, lithium secondary batteries are receiving attention for their advantages of being able to charge and discharge freely, having a very low self-discharge rate, and having a high energy density, as they have almost no memory effect compared to nickel-based secondary batteries.

[0006] These lithium secondary batteries primarily use lithium oxide and carbon materials as the positive and negative electrode active materials, respectively. The lithium secondary battery comprises an electrode assembly comprising a positive electrode plate and a negative electrode plate, each coated with the positive and negative electrode active materials, with a separator interposed between them, and a battery case that seals and houses the electrode assembly together with an electrolyte.

[0007] In general, lithium secondary batteries can be classified into can-type secondary batteries in which the electrode assembly is built into a metal can and pouch-type secondary batteries in which the electrode assembly is built into a pouch of an aluminum laminate sheet, depending on the shape of the outer packaging material.

[0008] Secondary batteries used in small devices are configured with two or three battery cells. However, secondary batteries used in medium- to large-sized devices such as automobiles utilize battery modules in which multiple battery cells are electrically connected. These battery modules enhance capacity and output by forming a battery cell stack by connecting multiple battery cells in series or parallel. One or more battery modules can be mounted together with various control and protection systems, such as a battery management system (BMS), a battery disconnect unit (BDU), and a cooling system, to form a battery pack.

[0009] A battery pack includes battery modules as a sub-concept, and battery modules, in turn, include battery cells as a sub-concept. The number of battery cells contained in a battery module or the number of battery modules contained in a battery pack can vary depending on the output or capacity of the battery pack required for the electric vehicle.

[0010] Recently, important requirements for battery modules and battery packs include quick charging and thermal propagation control.

[0011] First, one of the challenges of rapid charging is the heat generated during rapid charging. Therefore, a cooling system is essential to manage the heat generated during rapid charging to an appropriate level. Conventional battery modules utilize an edge-cooling structure that cools only one side (usually the bottom) of the battery cells. Applying rapid charging to an edge-cooled battery module increases the temperature difference between the top and bottom, and the top, with its limited cooling effect, inevitably reduces rapid charging efficiency. Therefore, ensuring effective cooling performance is crucial for rapid charging.

[0012] Next, with regard to thermal propagation control, when a thermal event occurs in one of the multiple battery cells included in a battery pack, it is necessary to block the thermal propagation of such a thermal event to other battery cells.

[0013] If heat transfer between battery cells is not properly controlled, this can lead to thermal events in other battery cells within the pack, potentially leading to more serious problems, such as fire or explosion within the pack. Furthermore, fire or explosion within the battery pack can cause significant damage to people and property in the vicinity. Therefore, these battery packs require a configuration capable of appropriately controlling the aforementioned thermal events and their propagation.

[0014] In summary, there is a growing demand for battery assemblies and battery packs that have effective cooling means for rapid charging and also have means to suppress heat transfer between battery cells.

[0015] The problem to be solved by the present invention is to provide a battery assembly having an effective cooling means for rapid charging and a means for suppressing heat transfer between battery cells, and a battery pack including the same.

[0016] However, the problems to be solved by the embodiments of the present invention 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.

[0017] A battery assembly according to one embodiment of the present invention comprises: a plurality of battery cells stacked along one direction; cell frames extending along edges of each of the battery cells and covering the edges of the battery cells; and a heat sink having at least one cooling plate positioned at least between the battery cells. A cell vent portion is formed at a portion of the cell frames corresponding to a lower end of the battery cell.

[0018] The cell frame may include a first frame covering a lower portion of the battery cell; a second frame covering an upper portion of the battery cell; and a third frame and a fourth frame covering both ends of the battery cell, respectively. The cell vent portion may be formed in the first frame.

[0019] The cell frame is provided for each of the above battery cells, so that the battery cells and the cell frame can correspond one-to-one.

[0020] An adhesive material may be attached to a portion of the lower portion of the battery cell other than the portion corresponding to the cell vent.

[0021] As the adjacent cell frames are joined together, the battery cells located therein can be fixed.

[0022] The battery assembly may include a cell assembly frame that accommodates the battery cells, and the cell assembly frame may include an upper frame that covers the upper portions of the battery cells; and a lower frame that covers the lower portions of the battery cells.

[0023] A vent cover portion that opens when a certain pressure is exceeded may be formed on the lower frame.

[0024] The above vent cover part can cover the cell vent part.

[0025] Venting gas generated from the above battery cell can be discharged through the cell vent part and the vent cover part.

[0026] A refrigerant can flow inside the above cooling plate.

[0027] The above battery cell and the above cooling plate can be in surface contact.

[0028] A chamfered portion may be provided at one end of the above cooling plate.

[0029] The battery assembly may include at least one pad member disposed at least between the battery cells.

[0030] Between the above battery cells, the cooling plate or the pad member may be positioned.

[0031] A battery pack according to one embodiment of the present invention comprises: the battery assembly; and a pack frame for accommodating the battery assembly. The pack frame includes a bottom frame on which the battery assembly is placed and in which a venting space is provided.

[0032] While venting gas is discharged from the battery cell, the cell vent portion may be connected to the venting space of the bottom frame.

[0033] The heat sink may include a cooling tube connected to the cooling plate. An area occupied by the cooling tube along the height direction may overlap at least partially with an area occupied by the venting space along the height direction.

[0034] According to embodiments of the present invention, surface cooling of the battery cells can be achieved by a cell frame covering the edges of the battery cells and a cooling plate disposed between the battery cells, thereby improving cooling performance.

[0035] Additionally, when a thermal event occurs in a battery cell, high-temperature venting gases or particles emitted from the cell travel along a specific, intended path through the cell vents provided in the cell frame. This minimizes the spread of a thermal event occurring in a specific battery cell to other battery cells.

[0036] The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

[0037] FIG. 1 is a perspective view of a battery assembly according to one embodiment of the present invention.

[0038] Figure 2 is an exploded perspective view of the battery assembly of Figure 1.

[0039] Fig. 3 is a perspective view showing a state in which a battery cell stack and a lower frame included in the battery assembly of Fig. 2 are combined.

[0040] Fig. 4 is a perspective view showing the battery cell stack and lower frame of Fig. 3 with the pad member separated.

[0041] FIG. 5 is a perspective view showing battery cells and cell frames according to one embodiment of the present invention.

[0042] Figure 6 is an exploded perspective view of the battery cells and cell frames of Figure 5.

[0043] Figure 7 is a perspective view showing a battery cell according to one embodiment of the present invention.

[0044] Figures 8 and 9 are cross-sectional perspective views of a battery cell coupled to a cell frame.

[0045] Figure 10 is a perspective view showing a cell frame according to one embodiment of the present invention.

[0046] Figure 11 is a perspective view showing two cell frames combined.

[0047] FIGS. 12 and 13 are perspective and front views showing heat sinks and pad members according to one embodiment of the present invention.

[0048] Figure 14 is a front view showing the heat sink, pad members and some cell frames.

[0049] Figure 15 is an exploded perspective view showing the battery cell, cooling plate and pad member combined in the cell frame.

[0050] FIG. 16 is a perspective view showing a heat sink according to one embodiment of the present invention.

[0051] FIG. 17 is a perspective view showing one cooling plate and cooling tube in the heat sink of FIG. 16.

[0052] FIG. 18 is a perspective view showing one of the cooling plates included in the heat sink of FIG. 16.

[0053] Figure 19 is an exploded perspective view of the cooling plate of Figure 18.

[0054] Figure 20 is a front view of the heat sink of Figure 16.

[0055] Figure 21 is a perspective view from below showing the battery cell stack and the lower frame combined.

[0056] Figure 22 is a perspective view of the battery cell stack viewed from below.

[0057] Fig. 23 is a cross-sectional perspective view showing the appearance cut along the cutting line AA of Fig. 3.

[0058] Figure 24 is a partial drawing showing an enlarged portion of the “B” portion of Figure 23.

[0059] Figure 25 is an exploded perspective view showing a lower frame according to one embodiment of the present invention.

[0060] Figures 26 (a) and (b) are a perspective view and a cross-sectional perspective view, respectively, showing a vent plate according to one embodiment of the present invention.

[0061] Figure 27 is a perspective view showing a battery pack according to one embodiment of the present invention.

[0062] Figure 28 is a perspective view showing the battery pack of Figure 27 with the pack cover removed.

[0063] Fig. 29 is a perspective view showing a pack frame included in the battery pack of Fig. 27.

[0064] Fig. 30 is a perspective view showing a floor frame included in the pack frame of Fig. 29.

[0065] Fig. 31 is a perspective view showing the arrangement of vent plates on the floor frame of Fig. 30.

[0066] FIG. 32 is a perspective view showing inner frames and cover plates according to one embodiment of the present invention.

[0067] Figure 33 is a partial drawing showing an enlarged portion of the “D” portion of Figure 32.

[0068] Fig. 34 is a perspective view showing a floor frame according to one embodiment of the present invention with a portion of the inner frame removed.

[0069] FIG. 35 is a perspective view showing an outer frame and routing plates according to one embodiment of the present invention.

[0070] Figure 36 (a) is a partial drawing showing an outer frame hole, and Figure 36 (b) is a partial drawing showing a venting device coupled to the outer frame hole.

[0071] Fig. 37 is a partial cross-sectional view showing a portion of a cross-section taken along the cutting line E-E' of Fig. 27.

[0072] FIG. 38 is a perspective view showing a battery cell, a heat sink, and a pad member according to another embodiment of the present invention.

[0073] Hereinafter, various embodiments of the present invention will be described in detail with reference to the attached drawings so that those skilled in the art can easily implement the invention. The present invention may be implemented in various different forms and is not limited to the embodiments described herein.

[0074] In order to clearly explain the present invention, parts that are not related to the description are omitted, and the same reference numerals are used for identical or similar components throughout the specification.

[0075] Furthermore, the sizes and thicknesses of each component shown in the drawings are arbitrarily indicated for convenience of explanation, and thus the present invention is not necessarily limited to the illustrated components. In the drawings, the thicknesses are enlarged to clearly represent various layers and regions. Furthermore, in the drawings, the thicknesses of some layers and regions are exaggerated for convenience of explanation.

[0076] Furthermore, when we say that a layer, membrane, region, plate, or other part is "on" or "over" another part, this includes not only cases where it is "directly on" the other part, but also cases where there are other parts in between. Conversely, when we say that a part is "directly on" another part, it means that there are no other parts in between. Furthermore, saying that a part is "on" or "over" a reference part means that it is located above or below the reference part, and does not necessarily mean that it is located "above" or "over" the direction opposite to gravity.

[0077] Additionally, throughout the specification, whenever a part is said to "include" a component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise specifically stated.

[0078] Additionally, throughout the specification, when we say "in plan", we mean when the target portion is viewed from above, and when we say "in cross section", we mean when the target portion is viewed from the side in a cross-section cut vertically.

[0079] Fig. 1 is a perspective view of a battery assembly according to one embodiment of the present invention. Fig. 2 is an exploded perspective view of the battery assembly of Fig. 1. Fig. 3 is a perspective view showing a state in which a battery cell stack and a lower frame included in the battery assembly of Fig. 2 are combined.

[0080] Referring to FIGS. 1 to 3, a battery assembly (100) according to one embodiment of the present invention includes: a plurality of battery cells (110) stacked along one direction; cell frames (300) extending along the edges of each of the battery cells (110) and covering the edges of the battery cells (110); and a heat sink (400) having at least one cooling plate (410) disposed at at least one location between the battery cells (110).

[0081] Specifically, the battery cells (110) may be stacked along one direction while each of the battery cells (110) is covered by a cell frame (300), thereby forming a battery cell stack (120). That is, a cell frame (300) is provided for each of the battery cells (110), so that the battery cells (110) and the cell frames (300) may correspond one-to-one. For example, the battery cell stack (120) may be formed by stacking the battery cells (110) along a direction parallel to the X-axis while each of the battery cells (110) is covered by a cell frame (300). The detailed structure of the cell frame (300) will be described later.

[0082] The battery assembly (100) according to the present embodiment may include a cell assembly frame (200) that accommodates battery cells (110). Specifically, the cell assembly frame (200) may accommodate battery cells (110) covered by a cell frame (300), i.e., a battery cell stack (120). The cell assembly frame (200) may include an upper frame (210) that covers the upper portions of the battery cells (110); and a lower frame (220) that covers the lower portions of the battery cells (110).

[0083] The upper frame (210) may include side portions (211) that cover both side surfaces of the battery cell stack (120) in the direction in which the battery cells (110) are stacked, and a ceiling portion (212) that covers the upper surface of the battery cell stack (120). In particular, the ceiling portion (212) may cover the upper portions of the cell frames (300) in the battery cell stack (120). The side portions (211) may extend downward from both facing sides of the ceiling portion (212).

[0084] Meanwhile, the cell assembly frame (200) may include a mounting portion (200M) that is a portion that secures the battery assembly (100) to a pack frame to be described later. A mounting hole is formed in the mounting portion (200M), and a bolt member may pass through the mounting hole to be fastened to the pack frame to be described later. For example, the mounting portion (200M) may be provided on a side portion (211) of the upper frame (210), and there is no particular limitation on the number or size thereof.

[0085] The lower frame (220) may include a first lower cover (221), a second lower cover (222), and a vent plate (223) positioned between the first lower cover (221) and the second lower cover (222). In addition, the lower frame (220) may further include an adhesive portion (224) that joins the vent plate (223) and the battery cell stack (120). The adhesive portion (224) may extend along the edge of the vent plate (223). The lower frame (220) may be combined with the upper frame (210) to form a cell assembly frame (200), and the cell assembly frame may cover the upper surface, the lower surface, and both side surfaces of the battery cell stack (120). The first lower cover (221), the second lower cover (222), and the vent plate (223) will be described later with reference to FIGS. 25 and 26 .

[0086] Fig. 4 is a perspective view showing the battery cell stack and lower frame of Fig. 3 with the pad member separated. Fig. 5 is a perspective view showing battery cells and cell frames according to one embodiment of the present invention. Fig. 6 is an exploded perspective view of the battery cells and cell frames of Fig. 5. Fig. 7 is a perspective view showing a battery cell according to one embodiment of the present invention.

[0087] Referring to FIGS. 4 to 7, the battery cell (110) according to the present embodiment may be a battery cell of various shapes. For example, as illustrated in FIGS. 5 to 7, the battery cell (110) according to the present embodiment may be a pouch-type battery cell. Hereinafter, a pouch-type battery cell will be described, but the battery cell (110) according to the present embodiment is not limited thereto, and various types of battery cells may be applied.

[0088] The battery cell (110) according to the present embodiment may be in the form of an electrode assembly having electrode leads (111) protruding in one or both directions, housed in a pouch case (114). The battery cell (110) may have a rectangular sheet shape. The battery cell (110) may have a lower portion (114a), an upper portion (114b), and both ends (114c, 114d).

[0089] The battery cell (110) can be formed by housing an electrode assembly in a pouch case (114) of a laminate sheet including a resin layer and a metal layer, and then bonding the outer periphery of the pouch case (114). For example, the battery cell (110) can have a structure in which two electrode leads (111) face each other and protrude from one end (114c) and the other end (114d) of the cell body (113), respectively. As another embodiment, a structure in which all electrode leads (111) of the battery cell (110) protrude in one direction is also possible. One of the electrode leads (111) is a positive electrode lead, and the other is a negative electrode lead.

[0090] The battery cell (110) can be manufactured by bonding the two ends (114c, 114d) of the pouch case (114) and the lower end (114a) connecting them while the electrode assembly (not shown) is housed in the pouch case (114). In other words, the battery cell (110) according to one embodiment of the present invention has a total of three sealing portions (114s), and the sealing portions (114s) have a structure in which they are sealed by a method such as fusion, and the remaining upper end (114b) can be formed as a folding portion. That is, the battery cell (110) according to the present embodiment can be a pouch-type secondary battery in which the electrode assembly is housed inside the pouch case (114) and the outer periphery of the pouch case (114) is sealed to form the sealing portion (114s). In Fig. 7, only the sealing portions (114s) formed at both ends (114c, 114d) of the pouch case (114) are shown, and the sealing portion at the lower end (114a) is not shown. However, the sealing portion at the lower end (114a) is folded to one side after sealing is completed for space utilization. This will be explained again in Fig. 9.

[0091] The pouch case (114) of the laminate sheet may include an inner resin layer for sealing, a metal layer for preventing penetration of materials, and an outermost outer resin layer. Based on the electrode assembly inside the pouch case (114), the inner resin layer may be positioned at the innermost side, the outer resin layer may be positioned at the outermost side, and the metal layer may be positioned between the inner resin layer and the outer resin layer.

[0092] The outer resin layer may have excellent tensile strength and weather resistance relative to its thickness and may exhibit electrical insulation properties to protect the electrode assembly from the outside. The outer resin layer may include polyethylene terephthalate (PET) resin or nylon resin. The metal layer may prevent air, moisture, etc. from entering the pouch-type secondary battery. The metal layer may include aluminum (Al). The inner resin layers may be thermally bonded to each other by heat and / or pressure applied while the electrode assembly is embedded. The inner resin layer may include cast polypropylene (CPP) or polypropylene (PP).

[0093] A pouch case (114) may be divided into two parts, and a concave receiving portion in which an electrode assembly can be mounted may be formed in at least one of the two parts. Along the outer periphery of the receiving portion, the inner resin layers of the two parts of the pouch case (114) may be bonded to each other to form a sealing portion (114s). In this manner, the pouch case may be sealed, and a battery cell (110), which is a pouch-type secondary battery, may be manufactured.

[0094] As described above, the battery cells (110) may be configured in plurality within the battery assembly (100). For example, the plurality of battery cells (110) may be stacked along one direction so as to be electrically connected to each other to form a battery cell stack (120). For example, the plurality of battery cells (110) may be stacked along a direction parallel to the X-axis while standing upright. Accordingly, the electrode leads (111) may protrude in a direction perpendicular to the direction in which the battery cells (110) are stacked. In the battery cell (110), one electrode lead (111) may protrude toward the Y-axis direction, and the other electrode lead (111) may protrude toward the -Y-axis direction. If the electrode leads (111) are battery cells that protrude in only one direction, the electrode leads (111) may protrude in the Y-axis direction or the -Y-axis direction.

[0095] FIGS. 8 and 9 are cross-sectional perspective views of battery cells coupled to a cell frame. Specifically, FIG. 8 is a cross-sectional perspective view of a battery cell coupled to a cell frame taken along the xy plane, and FIG. 9 is a cross-sectional perspective view of a battery cell coupled to a cell frame taken along the xz plane. FIG. 10 is a perspective view showing a cell frame according to one embodiment of the present invention. FIG. 11 is a perspective view showing a state in which two cell frames are coupled.

[0096] Referring to FIGS. 5 to 11 together, the cell frame (300) according to the present embodiment extends along the edge of the battery cell (110) and can cover the edge of the battery cell (110). A cell vent portion (300V) is formed in a portion of the cell frame (300) corresponding to the lower portion (114a) of the battery cell (110).

[0097] Specifically, the cell frame (300) may include a first frame (310) covering the lower end (114a) of the battery cell (110); a second frame (320) covering the upper end (114b) of the battery cell (110); and a third frame (330) and a fourth frame (340) covering the opposite ends (114c, 114d) of the battery cell (110), respectively. As described above, the battery cells (110) and the cell frames (300) correspond one-to-one, and each of the battery cells (110) may be covered by each of the cell frames (300).

[0098] The cell vent part (300V) may be formed in the first frame (310) of the cell frames (300). Specifically, the cell vent part (300V) may be a part that guides the discharge of high-temperature venting gas or particles generated from a battery cell (110) when a thermal event or thermal runaway occurs in a battery cell (110). This cell vent part (300V) may be provided in the central part of the first frame (310) that covers the lower part (114a) of the battery cell (110).

[0099] For example, the cell vent part (300V) may include a first part (300V1), a second part (300V2), and a third part (300V3). The first part (300V1), the second part (300V2), and the third part (300V3) may extend downward, forming an open space therebetween. However, this is only one exemplary structure of the cell vent part (300V), and it is sufficient as long as it can guide the discharge of high-temperature venting gas or particles generated from the battery cell (110) in an open form, and there are no other limitations on its form.

[0100] The portion of the first frame (310) excluding the cell vent portion (300V) is in close contact with the lower portion (114a) of the battery cell (110), but the portion corresponding to the cell vent portion (300V) is perforated downward, so that high-temperature venting gas or particles generated from the battery cell (110) can be discharged downward through the cell vent portion (300V). That is, the battery assembly according to the present embodiment has a directional venting structure that discharges venting gas and particles, etc. in a preset direction through the cell frame (300) having the cell vent portion (300V). In particular, since the cell vent portion (300V) is formed in the portion of the cell frame (300) corresponding to the lower portion (114a) of the battery cell (110), a so-called “lower venting” structure in which venting gas and particles, etc. are discharged downward can be implemented. The advantages of the “lower venting” structure will be explained again below.

[0101] Meanwhile, referring to FIGS. 5 to 9, an adhesive member (130) may be attached to a portion of the lower portion (114a) of the battery cell (110) except for a portion corresponding to the cell vent portion (300V). As described above, the lower portion (114a) of the battery cell (110) may be a sealing portion (114s, see FIGS. 7 and 9) where the pouch case (114) is sealed, and the upper portion (114b) of the battery cell (110) may not be a sealing portion but may be a folding portion where the pouch case (114) is folded. When a thermal event or thermal runaway occurs in the battery cell (110), venting gas is generated in the battery cell (110) and the internal pressure of the battery cell (110) increases. These venting gases can be mainly discharged through the sealing portion (114s) of the battery cell (110). That is, due to increased internal pressure, the sealing portion of the sealing portion (114s) is released, and the venting gases, etc. can be discharged through the released sealing portion (114s).

[0102] In the battery assembly (100) according to the present embodiment, the battery cells (110) may be arranged so that the lower portion (114a) of the battery cells (110) becomes a sealing portion (114s) and the upper portion (114b) of the battery cells (110) becomes a folding portion. Through this arrangement, a “lower venting” structure that discharges venting gases and particles generated from the battery cells (110) downward can be more clearly implemented. FIG. 9 shows a sealing portion (114s) corresponding to the lower portion (114a) of the battery cells (110) folded for space utilization after sealing is completed.

[0103] Meanwhile, it is preferable that the venting gas of the battery cell (110) be discharged through the cell vent portion (300V) of the cell frame (300), among the downward directions. To this end, an adhesive member (130) may be attached to a portion of the lower portion (114a) of the battery cell (110) other than the portion corresponding to the cell vent portion (300V). The adhesive member (130) may be, for example, an adhesive tape.

[0104] The portion of the lower part (114a) of the battery cell (110) to which the adhesive member (130) is attached is not sealed even if the internal pressure of the battery cell (110) increases because the degree of sealing is supplemented by the adhesive member (130). On the other hand, the portion of the lower part (114a) of the battery cell (110) to which the adhesive member (130) is not attached has a relatively low degree of sealing, so the sealing may be released before the portion to which the adhesive member (130) is attached. Accordingly, the venting gas may be discharged to the portion corresponding to the cell vent part (300V) of the lower part (114a) of the battery cell (110) (i.e., the portion without the adhesive member), and the venting gas may be discharged downward through the cell vent part (300V).

[0105]

[0106] Referring again to FIGS. 4, 5, 6, 10, and 11, in the battery cell stack (120) according to the present embodiment, adjacent cell frames (300) may be coupled to each other, and battery cells (110) located therein may be fixed. There is no particular limitation on the coupling method between the cell frames (300), but coupling may be achieved by physical restraint. For example, each cell frame (300) may include a hook protrusion (300P) and a hook groove (300G). The hook protrusion (300P) may protrude in the direction in which another adjacent cell frame (300) is located. The cell frames (300) may be coupled to each other in such a manner that the hook protrusion (300P) of one cell frame (300) is hook-coupled to the hook groove (300G) of another adjacent cell frame (300). An example of such a hook coupling between two cell frames (300) is illustrated in FIG. 11. As the connection between the hook protrusion (300P) and the hook groove (300G) is continuously performed for each adjacent cell frame (300), a plurality of cell frames (300) can all be connected.

[0107] Each battery cell (110) is covered by each cell frame (300), and a battery cell stack (120) can be formed by combining these cell frames (300). The battery cell stack (120) including the cell frames (300) in this way is structurally more stable and can withstand external vibrations or shocks better than a form in which only the battery cells (110) are stacked without the cell frames (300). In the case in which only the battery cells (110) are stacked without the cell frames (300), there may be a problem in that the battery cell stack cannot be maintained by external vibrations or shocks and the shape collapses. In addition, in the case of the battery cell stack (120) including the cell frames (300), since it is assembled in units of cell frames (300), replacement can be easily performed in units of cell frames (300). That is, even after the battery cell stack (120) has already been manufactured, there is an advantage in that a specific battery cell (110) that has a problem can be easily replaced by disassembling and reassembling the cell frame (300).

[0108]

[0109] Below, the heat sink and pad member included in the battery assembly according to the present embodiment will be described in detail.

[0110] Figures 12 and 13 are perspective views and front views illustrating a heat sink and pad members according to one embodiment of the present invention. Figure 14 is a front view illustrating a heat sink, pad members, and some cell frames. Specifically, Figure 14 illustrates four cell frames (300) interposed between cooling plates (410) of a heat sink (400) and pad members (500). Figure 15 is an exploded perspective view illustrating a battery cell, cooling plate, and pad member coupled to a cell frame.

[0111] Referring to FIGS. 12 to 15, as described above, the battery assembly according to the present embodiment includes a heat sink (400), and the heat sink (400) includes at least one cooling plate (410) disposed at least in one location between battery cells (110). A coolant may flow inside the cooling plate (410). Specifically, the cooling plate (410) has a coolant path, which is a space in which the coolant flows, and may be in contact with the battery cells (110).

[0112] Specifically, the battery cell (110) and the cooling plate (410) can be in surface contact. At least one surface of the battery cell (110) can be in surface contact with the cooling plate (410). More specifically, one surface of the cooling plate (410) can be in contact with one surface of the cell body (113, see FIG. 7) of the battery cell (110). One surface of the battery cell (110) can be in contact with the cooling plate (410), or both sides of the battery cell (110) can be in contact with the cooling plate (410). That is, at least one surface of the battery cell (110) can be in direct surface contact with the cooling plate (410).

[0113] The cooling plate (410) can cool the battery cell (110) in a plate-like shape. The coolant flowing inside the cooling plate (410) may be cooling water. The battery assembly (100) according to the present embodiment may have a water-cooling structure.

[0114] Conventional battery assemblies have an edge cooling structure in which a thermal resin layer is brought into contact with the edge portion of a battery cell, and the heat of the battery cell is discharged by the thermal resin layer directly / indirectly coming into contact with a heat sink. On the other hand, the battery assembly (100) according to the present embodiment may have a surface cooling structure in which a cooling plate (410) through which a coolant flows is interposed between the battery cells (110) and comes into contact with one surface of the cell body (113, see FIG. 7) of the battery cells (110). Since one surface of the cell body (113, see FIG. 7) of the battery cell (110) can come into contact with one surface of the cooling plate (410), the cooling area is much larger, and thus there is an advantage of superior cooling performance compared to conventional battery assemblies.

[0115] Recently, quick charging has become a prerequisite for battery assemblies, but one of the problems with quick charging is the heat generated during quick charging. A cooling system is essential for managing the heat generated during the process to an appropriate level. When quick charging is applied to a conventional edge-cooled battery assembly, the temperature difference between the upper and lower portions increases, and the upper portion, with its insufficient cooling effect, inevitably results in reduced quick charging efficiency. On the other hand, the battery assembly (100) according to the present embodiment has excellent cooling performance capable of controlling heat generation during quick charging because the cooling plate (410) makes surface contact with the battery cells (110) and directly cools them.

[0116] Within the battery assembly (100), there is no particular limitation on the number or size of the cooling plates (410), as long as surface cooling of the battery cells (110) can be performed. The number of cooling plates (410) may be appropriately changed in consideration of the size, capacity, heat generation, etc. of the battery assembly (100). In addition, there is no particular limitation on the area of ​​the cooling plate (410), as long as it can cover 60% or more of the area of ​​one side of the battery cell (110). However, a plurality of cooling plates (410) may be provided within the battery assembly (100), and it is preferable that the number of cooling plates (410) be sufficient so that one side of all the battery cells (110) can be in contact with the cooling plates (410).

[0117] Meanwhile, referring to FIG. 7, the sealing portion (114s) at both ends (114c, 114d) of the battery cell (110) where the electrode lead (111) protrudes from the battery cell (110) corresponds to the so-called terrace portion of the battery cell (110). This terrace portion is thinner than the cell body (113) of the battery cell (110). Referring again to FIG. 15, due to the thin thickness of the terrace portion, a slight gap may occur between the terrace portion of the battery cell (110) and the cooling plate (410). In order to fill the gap between the terrace portion of the battery cell (110) and the cooling plate (410), a spacer (700) may be additionally provided between the terrace portion of the battery cell (110) and the cooling plate (410).

[0118] Meanwhile, referring again to FIGS. 12 to 15, the battery assembly according to the present embodiment may include at least one pad member (500) positioned at at least one location between the battery cells (110). The pad member (500) may be a foam-type member having thermal insulation properties. As long as the pad member (500) has thermal insulation properties and a certain degree of elasticity, there is no particular limitation on the material of the pad member (500). For example, the pad member (500) may include a silicone material or an aerogel material.

[0119] In one embodiment of the present invention, a cooling plate (410) or a pad member (500) may be positioned between battery cells (110). Specifically, in the battery cell stack (120), the battery cells (110) are stacked while being covered by a cell frame (300), and either a cooling plate (410) or a pad member (500) may be positioned between adjacent battery cells (110). More specifically, as illustrated in FIGS. 12 to 14, the cooling plates (410) and the pad members (500) may be alternately arranged one by one along the X-axis direction, which is the direction in which the battery cells (110) are stacked. The battery cells (110) coupled to the cell frame (300) may be interposed in the space (S, see FIG. 13) between the cooling plates (410) and the pad members (500). Fig. 14 illustrates that each of the four cell frames (300) is interposed between a cooling plate (410) and a pad member (500). Of course, in Fig. 14, the battery cell (110) is not visible because it is covered by the cell frame (300), but the battery cell (110) is located inside the cell frame (300).

[0120] Accordingly, as illustrated in FIG. 15, in one battery cell (110), one side of the battery cell (110) may be in contact with the cooling plate (410) of the heat sink (400), and the opposite side of the battery cell (110) may be in contact with the pad member (500). However, this is just one example, and in another embodiment of the present invention, cooling plates (410) may be positioned on both sides of the battery cell (110) without the pad member (500). The thermal propagation prevention function and swelling control function of the cooling plate (410) and the pad member (500) will be described later.

[0121]

[0122] Below, the structure of the heat sink according to the present embodiment will be described in detail.

[0123] Fig. 16 is a perspective view illustrating a heat sink according to one embodiment of the present invention. Fig. 17 is a perspective view illustrating one cooling plate and cooling tube in the heat sink of Fig. 16. Fig. 18 is a perspective view illustrating one of the cooling plates included in the heat sink of Fig. 16. Fig. 19 is an exploded perspective view of the cooling plate of Fig. 18. Fig. 20 is a front view of the heat sink of Fig. 16.

[0124] Referring to FIGS. 16 to 20, a heat sink (400) according to the present embodiment may include cooling plates (410) that surface-cool a battery cell (110) and cooling tubes (420) connected to the cooling plates (410).

[0125] First, the cooling plate (410) may include a first cooling cover (411), a second cooling cover (412), and a cooling center plate (413) positioned between the first cooling cover (411) and the second cooling cover (412). The first cooling cover (411), the cooling center plate (413), and the second cooling cover (412) may be positioned sequentially along the -X-axis direction among the directions in which the battery cells (110) are stacked.

[0126] A refrigerant path (CP), which is a path through which refrigerant flows, may be provided in the cooling center plate (413). By sealing this refrigerant path (CP) between the first cooling cover (411) and the second cooling cover (412), the path through which the refrigerant flows may be completed. As an example, FIG. 19 illustrates the refrigerant path (CP) as a meandering path, but there are no special limitations on the width, shape, area, etc. of the refrigerant path (CP) as long as the refrigerant can flow. In addition, as another embodiment, the refrigerant path (CP) may be implemented as a single empty space. The width, shape, area, etc. of the refrigerant path (CP) may be appropriately adjusted in consideration of the flow rate, flow rate, etc. of the refrigerant.

[0127] The cooling plate (410) may include an inlet (410N) and an outlet (410U) connected to a refrigerant path (CP). Each of the inlet (410N) and the outlet (410U) of the cooling plate (410) may be connected to a cooling tube (420). The cooling tubes (420) may supply refrigerant to the cooling plate (410) and discharge refrigerant from the cooling plate (410). Specifically, the cooling tube (420) may include a first cooling tube (421) and a second cooling tube (422), and the first cooling tube (421) may be connected to the inlet (410N) of the cooling plate (410), and the second cooling tube (422) may be connected to the outlet (410U) of the cooling plate (410).

[0128] The first cooling tube (421) and the second cooling tube (422) can be connected to a refrigerant circulation system (not shown) provided inside or outside the battery pack. The refrigerant moving along the first cooling tube (421) from the refrigerant circulation system can be introduced into the refrigerant path (CP) through the inlet (410N) of the cooling plate (410) and flow inside the cooling plate (410). Thereafter, the refrigerant discharged from the refrigerant path (CP) through the outlet (410U) of the cooling plate (410) can flow along the second cooling tube (422) and then be returned to the refrigerant circulation system again. Through the above process, a refrigerant circulation structure can be implemented within the battery assembly (100). The heat generated from the battery cells (110) inside the battery assembly (100) can be transferred to the coolant introduced into the coolant path (CP) of the cooling plate (410) and discharged to the outside of the battery assembly (100) along the second cooling tube (422). Thereafter, the coolant cooled again in the coolant circulation system can be introduced into the coolant path (CP) of the cooling plate (410) again through the first cooling tube (421). That is, the battery assembly (100) according to the present embodiment can have a structure that discharges the heat generated from the battery cells (110) through the coolant flowing along the heat sink (400).

[0129] Meanwhile, as illustrated in FIG. 20, a chamfered portion (410CH) may be provided at one end of the cooling plate (410). The chamfered portion (410CH) may be a portion whose thickness gradually narrows toward the outside of the cooling plate (410) from one end of the cooling plate (410).

[0130] In a battery cell stack (120) formed by stacking battery cells (110) mounted on a cell frame (300) in one direction, a cooling plate (410) can be inserted into a gap between the battery cells (110). Since a chamfered portion (410CH) is provided at one end of the cooling plate (410), when the cooling plate (410) is assembled to the battery cell stack (120), the cooling plate (410) can be easily inserted between the battery cells (110). The cooling plate (410) can be pushed in while being pressed closely between the battery cells (110) starting from the chamfered portion (410CH).

[0131]

[0132] Referring again to FIGS. 2 to 6, the battery assembly (100) may further include a bus bar (610) and a terminal bus bar (620) connected to the electrode leads (111) of the battery cells (110). The bus bar (610) and the terminal bus bar (620) may be electrically connected to the electrode leads (111) of the battery cells (110). For example, the bus bar (610) and the terminal bus bar (620) may be joined to the electrode leads (111) by welding. The bus bar (610) and the terminal bus bar (620) may be arranged on both sides (the side in the Y-axis direction and the side in the -Y-axis direction) of the battery cell stack (120) that are not covered by the cell assembly frame (200).

[0133] Battery cells (110) can be electrically connected in series or parallel via these bus bars (610).

[0134] The terminal bus bar (620) may be electrically connected to the electrode leads (111) of some battery cells (110), and a portion thereof may be exposed to the outside of the battery assembly (100). The battery assembly (100) may form an HV (High voltage) connection with other battery assemblies or electrical components through the terminal bus bar (620). Here, the HV connection is a connection that serves as a power source to supply power requiring high voltage, and refers to a connection between battery cells or a connection between battery assemblies.

[0135] Meanwhile, although not specifically illustrated, the battery assembly (100) may include a connector. The connector (not illustrated) is a member for LV (Low Voltage) connection of the battery assembly (100). LV connection refers to an electrical connection that requires a relatively low voltage, such as a battery electrical component. For example, a sensing member (not illustrated) may sense voltage data of battery cells (110) or temperature data inside the battery assembly (100), and a connector connected to the sensing member may transmit the sensed voltage data or temperature data to a BMS (Battery Management System) located outside the battery assembly (100). Accordingly, a portion of the connector may also be exposed to the outside of the battery assembly (100).

[0136]

[0137] Hereinafter, the functions of the cell frame (300), the cooling plate (410) of the heat sink (400), and the pad member (500) in the battery assembly (100) according to the present embodiment will be described in more detail.

[0138] Referring to FIGS. 5 to 19 together, the cell frame (300) according to the present embodiment extends along the edge of each of the battery cells (110) and covers the edges of the battery cells (110), so that one surface of the cell body (113) of the battery cell (110) is exposed without being covered by the cell frame (300). The cell frame (300) can stably fix the battery cells (110), and at the same time, guide one surface of the cell body (113) of the battery cells (110) to come into contact with the cooling plate (410) of the heat sink (400). That is, surface cooling of the battery cells (110) in the battery cell stack (120) can be implemented by the cell frame (300) and the cooling plate (410). Accordingly, the battery assembly (100) according to the present embodiment can have excellent cooling performance capable of controlling heat generation during rapid charging.

[0139] Since one side of the cell body (113) of the battery cell (110) is in close contact with the cooling plate (410) or the pad member (500), even if a thermal event or thermal runaway occurs in the battery cell (110), it is difficult for heat to propagate and venting gas to be discharged in the surface direction, that is, the X-axis or -X-axis direction in which the battery cells (110) are stacked. Accordingly, there is a high possibility that high-temperature venting gas or particles due to thermal runaway of the battery cell (110) will be discharged through the lower end (114a), upper end (114b), or both ends (114c, 114d) of the battery cell (110). There is a high possibility that high-temperature venting gas or particles will be discharged when the sealing is released at the lower end (114a) and both ends (114c, 114d) where the sealing portion (114s) is provided. In particular, the sealing portion (114s) at both ends (114c, 114d) of the battery cell (110) from which the electrode lead (111) protrudes is called a terrace part. In a conventional battery assembly, venting gas was mainly discharged when the sealing was released at this terrace part.

[0140] However, according to the present embodiment, since the first to fourth frames (310, 320, 330, 340) of the cell frame (300) are in close contact with the lower end (114a), the upper end (114b), and both ends (114c, 114d) of the battery cell, respectively, the venting gas or particles may be restricted from being discharged through the edges of the battery cell (110). Instead, since a cell vent part (300V) that is open downward is provided in the part corresponding to the lower end (114a) of the battery cell among the cell frames (300) according to the present embodiment, i.e., the first frame (310), high-temperature venting gas or particles generated during the thermal runaway process of the battery cell (110) may be induced to be discharged only through the cell vent part (300V). That is, the battery assembly (100) according to the present embodiment can induce directional venting in the downward direction, i.e., “bottom venting,” by the cell frame (300) having the cell vent portion (300V). In addition, as described above, venting only toward the cell vent portion (300V) can be more clearly implemented by the adhesive member (130) attached to a portion of the lower portion (114a) of the battery cell (110) other than the portion corresponding to the cell vent portion (300V).

[0141] Meanwhile, as will be described later, when the battery assembly (100) is housed in the pack frame, venting gas or particles discharged from the cell vent section (300V) can be discharged to the outside of the pack frame through the inside of the bottom frame of the pack frame. This will be described in detail later with reference to FIGS. 27 to 37.

[0142] In the battery assembly (100), there is a high-voltage current path, such as the HV (High voltage) connection of the bus bar (610) or the terminal bus bar (620). Here, the HV connection is a connection that serves as a power source to supply power that requires high voltage, and refers to a connection between battery cells or a connection between battery assemblies. At this time, if high-temperature gas or particles, etc. due to a thermal event of the battery cell (110) come into contact with a high-voltage path such as the HV connection, a short circuit or arc discharge may occur, which may lead to additional explosion and flame generation. In particular, the terrace part is a part adjacent to the electrode lead (111), the bus bar (610), etc., and the venting gas discharged through the terrace part may be more dangerous because it directly affects the HV connection. On the other hand, in the case of the battery pack according to the present embodiment, as mentioned above, since it has a “bottom venting” structure through the cell vent part (300V), high-temperature gas or particles due to a thermal event may be discharged downward. In particular, as will be described later, it can be discharged externally through the bottom frame of the pack frame. Therefore, there is no risk of high-temperature gases or particles reaching high-voltage paths, such as HV connections, and ultimately, safety against thermal runaway can be enhanced.

[0143] Meanwhile, as described above, since one side of the cell body (113) of the battery cell (110) is in close contact with the cooling plate (410) or the pad member (500), the cooling plate (410) and the pad member (500) can minimize the heat propagation of the thermal runaway phenomenon occurring in the battery cell (110) to other adjacent battery cells (110). That is, the cooling plate (410) can implement excellent cooling performance capable of controlling heat generation during rapid charging through the surface cooling structure, while simultaneously preventing thermal propagation between the battery cells (110). In particular, the cooling plate (410) has a configuration in which a coolant flows inside, so it can lower the thermal runaway temperature of the battery cell (110) and is effective in preventing thermal propagation between the battery cells (110) because it blocks the lateral direction. Likewise, the pad member (500) can also prevent thermal propagation between battery cells (110). If the pad member (500) includes a material with excellent insulating properties, it can be more effective in preventing thermal propagation.

[0144] Meanwhile, during the process of repeated charging and discharging, the battery cells (110) may experience a swelling phenomenon, in which the internal electrolyte decomposes and gas is generated, causing the battery cells (110) to swell. In the swelling phenomenon of the battery cells (110), the battery cells (110) expand in the thickness direction. That is, the battery cells (110) may expand along the direction in which the battery cells (110) are stacked (the direction parallel to the X-axis). The pad member (5000) according to the present embodiment can control the swelling while absorbing the swelling of the battery cells (110). Accordingly, the battery assembly (100) can be prevented from being deformed beyond its deformation limit due to the swelling of the battery cells (110). The cooling plate (410) in contact with the other side of the battery cells (110) can also absorb the swelling of the battery cells (110) to some extent.

[0145]

[0146] Hereinafter, a vent plate and a vent cover according to one embodiment of the present invention will be described in detail.

[0147] Fig. 21 is a perspective view of a battery cell stack and a lower frame combined as seen from below. Fig. 22 is a perspective view of a battery cell stack as seen from below. That is, Fig. 22 shows a view with the lower frame removed from Fig. 21. Fig. 23 is a cross-sectional perspective view showing a view cut along the cutting line AA of Fig. 3. Fig. 24 is a partial view showing an enlarged portion of “B” of Fig. 23. Fig. 25 is an exploded perspective view showing a lower frame according to an embodiment of the present invention. Fig. 26 (a) and (b) are a perspective view and a cross-sectional perspective view, respectively, showing a vent plate according to an embodiment of the present invention. In particular, Fig. 26 (b) shows a view cut along the cutting line CC in Fig. 26 (a).

[0148] Referring to FIGS. 2, 3, and 21 to 26, as described above, the battery assembly (100) according to the present embodiment may include a cell assembly frame (200) that accommodates battery cells (110), and the cell assembly frame (200) may include an upper frame (210) that covers the upper portions of the battery cells (110); and a lower frame (220) that covers the lower portions of the battery cells (110).

[0149] A vent cover part (220VC) that opens when a certain pressure or higher may be positioned below the cell vent part (300V). For example, the vent cover part (220VC) that opens when a certain pressure or higher may be formed on the lower frame (220). For example, the lower frame (220) may include a first lower cover (221), a second lower cover (222), and a vent plate (223) positioned between the first lower cover (221) and the second lower cover (222).

[0150] A first lower cover (221), a vent plate (223), and a second lower cover (222) may be sequentially positioned along a direction from one end (114d) of the battery cell (110) to the other end (114c). That is, the vent plate (223) may be positioned corresponding to the cell vent portion (300V) of the cell frame (300), and a vent cover portion (220VC) may be provided on the vent plate (223).

[0151] The vent cover part (220VC) can cover the cell vent part (300V) of the cell frame (300). Specifically, the vent cover part (220VC) can cover the lower part of the cell vent part (300V) of the cell frame (300). The vent plate (223) including the vent cover part (220VC) can include a refractory material. For example, the vent plate (223) can include a MICA material.

[0152] The vent cover (220VC) may be a structure that opens when a certain pressure is applied due to venting gas discharged through the cell vent (300V). If this function is implemented, there are no special restrictions on the structure of the vent cover (220VC), nor are there any special restrictions on the standards for the pressure at which it opens. The standards for the pressure at which it opens may vary depending on the number, size, and components of the battery cells included in the battery assembly.

[0153] For example, the vent cover part (220VC) according to the present embodiment may include a connecting part (220C) that is connected to the vent plate (223), and a slit (220S) in the form of a hole may be formed on the three sides excluding the connecting part (220C). That is, by forming a slit (220S) on the three sides of the vent plate (223) excluding the connecting part (220C), the vent cover part (220VC) may be provided on the vent plate (223). There is no particular limitation on the number of vent cover parts (220VC) provided on the vent plate (223), but for example, the number of vent cover parts (220VC) may be the same as the number of cell vent parts (300V) in the battery cell stack (120), and each of the vent cover parts (220VC) may correspond one-to-one with each of the cell vent parts (300V).

[0154] Normally, the vent cover part (220VC) covers the lower part of the cell vent part (300V), but when venting gas is discharged from the battery cell (110) and a certain pressure or higher is applied to the vent cover part (220VC), the vent cover part (220VC) may be bent in the opposite direction to the direction in which the cell vent part (300V) is located, thereby opening the vent cover part (220VC). Accordingly, the venting gas generated from the battery cell may be discharged through the cell vent part (300V) and the vent cover part (220VC).

[0155] Meanwhile, the lower frame (220) may include an adhesive portion (224) that joins the vent plate (223) and the battery cell stack (120). This adhesive portion (224) may extend along the edge of the vent plate (223). More specifically, the adhesive portion (224) may be provided at the edge of the vent plate (223), and the vent plate (223) may be attached to the lower portion of the cell frame (300), i.e., the first frame (310) of the cell frame (300), through the adhesive portion (224). Since the adhesive portion (224) is attached to the edge of the vent plate (223), the venting gas or particles discharged from the cell vent portion (300V) may be prevented from leaking to a portion other than the vent cover portion (220VC).

[0156]

[0157] In addition, referring to FIGS. 10, 12, 15, 16, and 24, the cooling plate (410) according to the present embodiment may include a cooling plate protrusion (410P) that protrudes to correspond to the cell vent portion (300V) of the cell frame (300). The cooling plate protrusion (410P) may protrude downward from the lower side of the cooling plate (410) to face the cell vent portion (300V).

[0158] Additionally, the pad member (500) may include a pad member protrusion (500P) that protrudes to correspond to the cell vent portion (300V) of the cell frame (300). The pad member protrusion (500P) may protrude downward from the lower side of the pad member (500) to face the cell vent portion (300V).

[0159] As illustrated in FIG. 10, the cell vent portion (300V) may include a first portion (300V1), a second portion (300V2), and a third portion (300V3), and a portion facing the third portion (300V3) may be opened without any other member.

[0160] At this time, a cooling plate (410) or pad member (500) may be positioned between the battery cells (110), and a cooling plate protrusion (410P) or pad member protrusion (500P) may be positioned at a portion facing the third portion (300V3) of the cell vent portion (300V).

[0161] Specifically, as illustrated in FIG. 24, a pad member protrusion (500P) may be positioned opposite the third part (300V3) of one cell vent part (300V), and a cooling plate protrusion (410P) may be positioned opposite the third part (300V3) of another adjacent cell vent part (300V).

[0162] When the first part (300V1) and the second part (300V2) of the cell vent part (300V) come into contact with either the cooling plate protrusion (410P) or the pad member protrusion (500P), a path for venting can be formed in the cell vent part (300V). That is, the space surrounded by the first part (300V1), the second part (300V2), the third part (300V3), and the cooling plate protrusion (410P) or the pad member protrusion (500P) can become a venting path (VP, see FIG. 24) through which a venting gas passes. In addition, the lower part of the venting path (VP) can be blocked by the vent cover part (220VC) of the vent plate (223). Normally, the venting path (VP) is blocked by the vent cover part (220VC), but when a certain pressure or more is applied to the vent cover part (220VC), the vent cover part (220VC) may bend downwards, thereby opening the venting path (VP). Venting gas generated from the battery cell (110) may be discharged downward through the venting path (VP) of the cell vent part (300V).

[0163] Meanwhile, referring again to FIG. 2, the upper frame (210) of the cell assembly frame (200) may include side portions (211) and a ceiling portion (212) that cover the battery cell stack (120). The upper frame (210) may protect the battery cell stack (120) and control swelling of the battery cells (110). In addition, although a cell vent portion (300V) is provided in the cell frame (300), there may be venting gas leaking to other parts between the cell frames (300), and the upper frame (210) may block the leaking venting gas from spreading to the outside of the battery assembly (100).

[0164]

[0165] Hereinafter, a battery pack according to one embodiment of the present invention will be described in detail.

[0166] Fig. 27 is a perspective view illustrating a battery pack according to one embodiment of the present invention. Fig. 28 is a perspective view illustrating the battery pack of Fig. 27 with the pack cover removed. Fig. 29 is a perspective view illustrating a pack frame included in the battery pack of Fig. 27. Fig. 30 is a perspective view illustrating a bottom frame included in the pack frame of Fig. 29.

[0167] Referring to FIGS. 27 to 30, a battery pack (1000) according to one embodiment of the present invention includes a battery assembly (100); and a pack frame (1100) for accommodating the battery assembly (100). The pack frame (1100) includes a bottom frame (1200) on which the battery assembly (100) is placed and in which a venting space (VS) is provided. FIG. 27 illustrates a battery pack (1000) in which six battery assemblies (100) are placed on the bottom frame (1200).

[0168] The pack frame (1100) may include a side frame (1300) extending along the edge of the bottom frame (1200). For example, the side frame (1300) may include a first side frame (1310), a second side frame (1320), a third side frame (1330), and a fourth side frame (1340). The first side frame (1310), the second side frame (1320), the third side frame (1330), and the fourth side frame (1340) may be arranged along the four sides of the edge of the bottom frame (1200) having a rectangular shape. A storage space with an open upper portion is provided by the bottom frame (1200) and the side frames (1300), and a battery assembly (100) may be arranged in this storage space. After the battery assembly (100) is arranged in the storage space, a pack cover (1400) may cover the open upper portion of the storage space. The pack cover (1400) can be joined to the side frame (1300) of the pack frame (1100), and for example, welding or adhesive joining can be applied. The battery assembly (100) can be sealed by the pack frame (1100) and the pack cover (1400). In addition, a gasket can be interposed between the pack cover (1400) and the side frame (1300) to enhance sealing properties.

[0169] Meanwhile, the battery pack (1000) according to the present embodiment may include a mounting beam (1300M) provided on a side frame (1300) for fixing the battery pack (1000). For example, the mounting beams (1300M) formed on the side frame (1300) are illustrated in FIGS. 27 to 29. The mounting beams (1300M) may be utilized when mounting the battery pack (1000) on a device. For example, when mounting the battery pack (1000) on a vehicle device, the mounting beams (1300M) may be fixed to the chassis of the vehicle.

[0170] Additionally, according to the present embodiment, the battery pack (1000) may include a vertical beam (1800) positioned on the floor frame (1200) and dividing a space in which battery assemblies (100) are positioned. For example, FIGS. 28 and 29 illustrate three vertical beams (1800) that divide a storage space in which six battery assemblies (100) are positioned into three zones.

[0171]

[0172] Fig. 31 is a perspective view showing the arrangement of vent plates on the bottom frame of Fig. 30. That is, other parts of the battery assembly are omitted, and only the arrangement of the vent plate (223) of the battery assembly on the bottom frame (1200) is shown in Fig. 31.

[0173] Referring to FIGS. 21, 22, 30, and 31, a venting space (VS) is provided in the bottom frame (1200) through which venting gas and particles, etc., discharged from the cell vent part (300V) move. The cell vent part (300V) of the cell frame (300) may be communicated with the venting space (VS) of the bottom frame (1200). Specifically, while the venting gas is discharged from the battery cell (110) due to thermal runaway in the battery cell (110), the cell vent part (300V) may be communicated with the venting space (VS) of the bottom frame (1200). Accordingly, the venting gas may move from the cell vent part (300V) to the venting space (VS) of the bottom frame (1200).

[0174] More specifically, due to the cell vent part (300V) covering the lower part of the cell vent part (300V) of the cell frame (300), the cell vent part (300V) and the venting space (VS) of the floor frame (1200) may not be in communication during normal times. However, when the vent cover part (220VC) is opened due to the venting gas discharged through the cell vent part (300V), the cell vent part (300V) and the venting space (VS) of the floor frame (1200) become in communication, and the venting gas may move from the cell vent part (300V) to the venting space (VS) of the floor frame (1200).

[0175] High-temperature venting gas and particles introduced into the venting space (VS) can be discharged to the outside of the battery pack (1000). The battery pack (1000) according to the present embodiment has a so-called “bottom venting” structure that discharges high-temperature venting gas and particles to the outside using the bottom frame (1200). If high-temperature venting gas or particles caused by a thermal event of the battery cell (110) come into contact with a high-voltage path such as an HV connection, a short circuit or an arc discharge may occur, which may lead to additional explosion and flame generation. On the other hand, in the case of the battery pack (1000) according to the present embodiment, as mentioned above, since it has a “bottom venting” structure, high-temperature venting gas or particles caused by a thermal event are discharged downward, that is, to the bottom frame (1200). Therefore, there is no risk of high-temperature venting gases or particles reaching high-voltage paths such as HV connections, and ultimately, safety against thermal runaway can be improved.

[0176]

[0177] Below, as an example, the detailed structure of the floor frame (1200) will be described in detail.

[0178] Fig. 32 is a perspective view showing the inner frame and cover plates according to one embodiment of the present invention. Fig. 33 is a partial drawing showing an enlarged portion of “D” of Fig. 32.

[0179] Referring to FIGS. 28 to 33 together, a bottom frame (1200) according to one embodiment of the present invention may include an outer frame (1210) and an inner frame (1220) positioned above the outer frame (1210). The outer frame (1210) may be a plate positioned at the lowest end of the battery pack (1000), and the outer frame (1210) may be coupled to a side frame (1300).

[0180] The inner frame (1220) is a plate-shaped member, but may include concave portions (1221) and convex portions (1222). In the inner frame (1220), the concave portions (1221) and convex portions (1222) may be alternately arranged along the Y-axis direction. Meanwhile, in order to form a venting space (VS), a cover plate (1500) or the like may be coupled to both side surfaces of the inner frame (1220). The inner frame (1220) and the cover plate (1500) may be coupled by a method such as welding.

[0181] The venting space (VS) according to the present embodiment may include a first venting space (VS1) and a second venting space (VS2). Specifically, a portion of the concave portion (1221) of the inner frame (1220) surrounded by the cover plate (1500) and the vent plate (223) of the battery assembly (100) may correspond to the first venting space (VS1). That is, when the vent cover portion (220VC) is opened, the venting gas discharged from the cell vent portion (300V) may move to the first venting space (VS1).

[0182] In addition, a portion of the convex portion (1222) of the inner frame (1220) surrounded by the cover plate (1500) may correspond to a second venting space. In addition, the inner frame (1220) may include a plurality of filtering holes (1220H) that connect the first venting space (VS1) and the second venting space (VS2). That is, the venting gas (VG) introduced into the first venting space (VS1) may move to the second venting space (VS2) through the filtering holes (1220H). Particles, ash, byproducts, etc. contained in the high-temperature venting gas (VG) may be primarily filtered out while passing through the filtering holes (1220H). That is, in the case of the floor frame (1200) according to the present embodiment, the venting space (VS) is divided into a first venting space (VS1) and a second venting space (VS2), and the first venting space (VS1) and the second venting space (VS2) are connected through a filtering hole (1220H), thereby exerting a function of primarily filtering high-temperature venting gas (VG).

[0183] Meanwhile, a gas shield (1600) may be arranged in a concave portion (1221) of the inner frame (1220). Specifically, in order to separate a first venting space (VS1) located below one battery assembly (100) from a first venting space (VS1) located below another battery assembly (100) in adjacent battery assemblies (100) along the X-axis direction, a gas shield (1600) may be arranged in the concave portion (1221). According to this gas shield (1600), a venting gas discharged from one battery assembly (100) to the first venting space (VS1) may be prevented from flowing back into the first venting space (VS1) located below another adjacent battery assembly (100). That is, the gas shield (1600) according to the present embodiment may correspond to a member that independently separates the first venting space (VS1) so that each battery assembly (100) has an independent first venting space (VS1). Consequently, since the first venting spaces (VS1) are separated to correspond to each of the battery assemblies (100), thermal runaway transfer between the battery assemblies (100) can be minimized, and explosion and structural collapse of the battery pack can be prevented. The gas shield (1600) may be positioned at a location corresponding to the vertical beam (1800) described above.

[0184]

[0185] Fig. 34 is a perspective view showing a bottom frame according to one embodiment of the present invention with a portion of the inner frame removed. Fig. 35 is a perspective view showing an outer frame and routing plates according to one embodiment of the present invention. Fig. 36 (a) is a partial view showing an outer frame hole, and Fig. 36 (b) is a partial view showing a venting device coupled to the outer frame hole.

[0186] Referring to FIGS. 32 to 36 together, a routing plate (1700) may be positioned inside the convex portion (1222) of the inner frame (1220), i.e., in the second venting space (VS2). The routing plate (1700) may be a structure that has an internal space and extends along one direction (a direction parallel to the X-axis).

[0187] The battery pack (1000) may include a venting device (1900) provided in the pack frame (1100). For example, an outer frame hole (1210H) may be formed in the outer frame (1210), and a venting device (1900) may be mounted in the outer frame hole (1210H). The venting device (1900) is a general term for a member or mechanism provided to discharge venting gas, etc. For example, the venting device (1900) may be a valve structure that opens or bursts when the internal pressure exceeds a certain level.

[0188] At this time, the outer frame hole (1210H) and the venting device (1900) may be located in the inner space of the routing plate (1700). Accordingly, the venting gas (VG) introduced into the second venting space (VS2) through the filtering hole (1220H) as shown in FIG. 33 may be bent multiple times while moving into the inner space of the routing plate (1700) as shown in FIG. 34.

[0189] In this way, as the routing plate (1700) is provided inside the second venting space (VS2), the venting gas (VG) or particles introduced into the second venting space (VS2) move along the elongated venting path and bend the path several times. While the venting gas (VG) flows along the path elongated by the routing plate (1700), the temperature of the venting gas (VG) or particles may be lowered. Therefore, the venting gas (VG) or particles may be prevented from triggering an explosion. In addition, as the path of the venting gas (VG) is elongated, oxygen introduced from the outside of the battery pack (1000) is blocked from encountering the venting gas, etc., thereby preventing an explosion from occurring. In addition, large particles may be filtered out in the elongated path.

[0190] Fig. 37 is a partial cross-sectional view showing a portion of a cross-section taken along the cutting line E-E' of Fig. 27.

[0191] Meanwhile, referring to FIG. 37 together with FIGS. 15 to 22 and FIGS. 27 to 33, the area (A1) occupied by the cooling tube (420) along the height direction may overlap at least partially with the area (A2) occupied by the venting space (VS) along the height direction. As an example, FIG. 37 shows a case where the area (A1) occupied by the cooling tube (420) along the height direction and the area (A2) occupied by the venting space (VS) along the height direction overlap partially.

[0192] The height direction may correspond to a direction perpendicular to both the direction in which the battery cells (110) are stacked and the direction in which the electrode leads (111) protrude from the battery cells (110). The direction in which the battery cells (110) are stacked may be a direction parallel to the X-axis, the direction in which the electrode leads (111) protrude from the battery cells (110) may be a direction parallel to the Y-axis, and the height direction may be a direction parallel to the Z-axis.

[0193] As described above, the cooling tube (420) may be configured to supply and discharge refrigerant to and from the cooling plates (410) of the heat sink (400). In addition, the cell vent portion (300V) of the cell frame (300) may be connected to the venting space (VS) of the bottom frame (1200). Venting gas discharged from the battery cell (110) may move to the venting space (VS) through the cell vent portion (300V) of the cell frame (300). The venting gas may flow along the venting space (VS) and ultimately be discharged to the outside through the venting device (1900) mounted in the outer frame hole (1210H). The venting space (VS) may be implemented by the outer frame (1210) and the inner frame (1220) of the bottom frame (1200). The venting space (VS) may include a first venting space (VS1) and a second venting space (VS2), and the first venting space (VS1) and the second venting space (VS2) may be implemented by a concave portion (1221) and a convex portion (1222) of the inner frame (1220). This is an exemplary structure of the bottom frame (1200), and a detailed description thereof is omitted as it overlaps with the previously described content.

[0194] In the present embodiment, the cooling tube (420) for supplying and discharging the refrigerant and the venting space (VS), which is a path through which the venting gas is discharged from the floor frame (1200), may be arranged so that their areas in the height direction overlap each other. For a directional venting structure, the venting space (VS), which is a space through which the venting gas is discharged, may be provided in the floor frame (1200), and the remaining space in the floor frame (1200) other than the venting space (VS) may be utilized as a space for supplying the refrigerant to the cooling plates (410). The remaining space in the floor frame (1200) other than the venting space (VS) may be utilized as a space for arranging the cooling tube (420). Since the cooling tube (420) and the venting space (VS) are positioned together in the height direction, the space utilization in the height direction of the battery pack (1000) may be increased. This can lead to weight reduction of the battery pack (1000) and increase in battery capacity of the battery pack (1000).

[0195] Meanwhile, the area (A1) occupied by the cooling tube (420) along the height direction may overlap at least partly with the cell vent portion (300V) of the cell frame (300). In the present invention, there is no separate limitation on the position or number of the cell vent portion (300V) and the cooling tube (420). For example, referring to FIGS. 15 to 17, the cooling tube (420) may include a first cooling tube (421) and a second cooling tube (422), and the cell vent portion (300V) may be positioned between the first cooling tube (421) and the second cooling tube (422). Accordingly, the cooling plate protrusion portion (410P) and the pad member protrusion portion (500P) may also be positioned between the first cooling tube (421) and the second cooling tube (422) corresponding to the position of the cell vent portion (300V).

[0196] FIG. 38 is a perspective view showing a battery cell, a heat sink, and a pad member according to another embodiment of the present invention.

[0197] Referring to FIG. 38, a cell vent unit (300V) according to another embodiment of the present invention may be provided in multiple numbers, and a cooling tube (420) may be positioned between the cell vent units (300V). The cooling tube (420) may include a first cooling tube (421) and a second cooling tube (422), and both the first cooling tube (421) and the second cooling tube (422) may be positioned between a plurality of cell vent units (300V).

[0198] Each of the first cooling tube (421) and the second cooling tube (422) can be connected to the inlet (410N) and the outlet (410U) of the cooling plate (410). The cooling plate protrusions (410P) and the pad member protrusions (500P) can also be provided in plurality, corresponding to the positions of the cell vents (300V). The cooling tubes (420) can be positioned between the cooling plate protrusions (410P) and can also be positioned between the pad member protrusions (500P).

[0199] In the present invention, the cell vent part (300V) and the cooling tube (420) can overlap at least partially in the area occupied along the height direction. The positions or numbers of the cell vent part (300V) and the cooling tube (420) are not particularly limited and can be provided in various ways.

[0200] In this example, terms indicating directions such as front, back, left, right, up, and down are used, but these terms are only for convenience of explanation and may vary depending on the location of the target object or the location of the observer.

[0201] One or more battery assemblies according to the above-described embodiment can be mounted together with various control and protection systems such as a BMS (Battery Management System), a BDU (Battery Disconnect Unit), and a cooling system to form a battery pack.

[0202] The above battery assembly or battery pack can be applied to various devices. Specifically, it can be applied to transportation vehicles such as electric bicycles, electric vehicles, and hybrid vehicles, as well as ESS (Energy Storage Systems), but is not limited thereto. It can also be applied to various devices that utilize secondary batteries.

[0203] Although the 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 made by those skilled in the art using the basic concept of the present invention defined in the following claims also fall within the scope of the present invention.

[0204] Description of the symbol

[0205] 100: Battery assembly

[0206] 110: Battery cell

[0207] 200: Cell Assembly Frame

[0208] 300: Cell Frame

[0209] 300V: Cell vent

[0210] 400: Heat sink

[0211] 410: Cooling plate

[0212] 500: Absence of pad

[0213] 1000: Battery Pack

[0214] 1100: Pack Frame

[0215] 1200: Floor frame

[0216] 1300: Side frame

[0217] 1400: Pack Cover

Claims

1. A plurality of battery cells stacked along one direction; Cell frames extending along the edges of each of the battery cells and covering the edges of the battery cells; and A heat sink having at least one cooling plate disposed at least between the battery cells; A battery assembly in which a cell vent portion is formed in a portion corresponding to the lower portion of the battery cell among the cell frames.

2. In paragraph 1, The cell frame includes a first frame covering the lower portion of the battery cell; a second frame covering the upper portion of the battery cell; and a third frame and a fourth frame covering both ends of the battery cell, respectively. A battery assembly in which the cell vent portion is formed on the first frame.

3. In paragraph 1, A battery assembly in which the cell frame is provided for each of the battery cells, and the battery cells and the cell frame correspond one-to-one.

4. In paragraph 1, A battery assembly in which an adhesive material is attached to a portion of the lower portion of the battery cell except for a portion corresponding to the cell vent.

5. In paragraph 1, A battery assembly in which adjacent cell frames are joined together and the battery cells located therein are fixed.

6. In paragraph 1, Includes a cell assembly frame that houses the above battery cells, A battery assembly comprising: an upper frame covering the upper portions of the battery cells; and a lower frame covering the lower portions of the battery cells.

7. In paragraph 6, A battery assembly in which a vent cover portion that opens when a certain pressure is exceeded is formed on the lower frame.

8. In paragraph 7, A battery assembly in which the vent cover portion covers the cell vent portion.

9. In paragraph 7, A battery assembly in which venting gas generated from the battery cell is discharged through the cell vent portion and the vent cover portion.

10. In paragraph 1, A battery assembly in which coolant flows inside the above cooling plate.

11. In paragraph 1, A battery assembly in which the above battery cells and the above cooling plate are in surface contact.

12. In paragraph 1, A battery assembly in which a chamfer is provided at one end of the cooling plate.

13. In paragraph 1, A battery assembly comprising at least one pad member disposed at least between the battery cells.

14. In paragraph 13, A battery assembly in which the cooling plate or the pad member is positioned between the battery cells.

15. Battery assembly according to paragraph 1; including a pack frame for storing the above battery assembly; The above pack frame is a battery pack including a bottom frame on which the battery assembly is placed and in which a venting space is provided.

16. In paragraph 15, A battery pack in which the cell vent portion communicates with the venting space of the bottom frame while venting gas is discharged from the battery cell.

17. In paragraph 15, The heat sink includes a cooling tube connected to the cooling plate, A battery pack in which the area occupied by the cooling tube along the height direction overlaps at least partly with the area occupied by the venting space along the height direction.

Images