Battery assembly and battery pack including the same

Abstract

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 the edge of each of the battery cells and covering the edge of the battery cells; and a heat sink having at least one cooling plate disposed at least at one of the locations between the battery cells. A cell vent portion is formed in the cell frame at a portion corresponding to the lower portion of the battery cell.

Description

Technology Field

[0001] The present invention relates to a battery assembly and a battery pack including the same, and more specifically, to a battery assembly and a battery pack including the same capable of minimizing thermal runaway transition and preventing structural collapse. Background Technology

[0002] In modern society, as the use of portable devices such as mobile phones, laptops, camcorders, and digital cameras has become commonplace, the development of technologies related to such mobile devices is becoming active. Furthermore, rechargeable secondary batteries are being utilized as power sources for electric vehicles (EVs), hybrid electric vehicles (HEVs), and plug-in hybrid electric vehicles (P-HEVs) as a solution to address air pollution caused by conventional gasoline vehicles using fossil fuels; consequently, the need for the development of secondary batteries is increasing.

[0003] Currently commercialized rechargeable batteries include nickel-cadmium, nickel-hydrogen, nickel-zinc, and lithium-ion batteries. Among these, lithium-ion batteries are gaining attention for their advantages, such as the ability to charge and discharge freely with almost no memory effect compared to nickel-based batteries, a very low self-discharge rate, and high energy density.

[0004] These lithium secondary batteries primarily use lithium-based oxides and carbon materials as the positive and negative active materials, respectively. The lithium secondary battery comprises an electrode assembly in which a positive plate and a negative plate, each coated with the positive and negative active materials, are arranged with a separator in between, and a battery case that seals and houses the electrode assembly together with an electrolyte.

[0005] Generally, lithium secondary batteries can be classified according to the shape of the casing into can-type secondary batteries, in which the electrode assembly is embedded in a metal can, and pouch-type secondary batteries, in which the electrode assembly is embedded in a pouch of aluminum laminate sheet.

[0006] In the case of secondary batteries used in small devices, 2 to 3 battery cells are arranged, whereas in the case of secondary batteries used in medium to large devices such as automobiles, battery modules in which multiple battery cells are electrically connected are used. In such battery modules, capacity and output are improved by connecting multiple battery cells in series or parallel to form a battery cell stack. 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.

[0007] A battery pack includes battery modules as a sub-concept, and battery modules include battery cells as a sub-concept. Furthermore, the number of battery cells in a battery module or the number of battery modules in a battery pack can be determined in various ways depending on the output or capacity of the battery pack required for an electric vehicle.

[0008] Recently, key requirements for battery modules or battery packs include quick charging and thermal propagation control.

[0009] First, one of the drawbacks of rapid charging is the heat generated during the process. In other words, a cooling system is essential to manage the heat generated during rapid charging at an appropriate level. Conventional battery modules utilize an edge cooling structure that cools only one side (usually the bottom side) of the battery cells. When rapid charging is applied to battery modules with an edge cooling structure, the temperature difference between the top and bottom increases, and rapid charging efficiency inevitably drops in the upper section, where the cooling effect is insufficient. Therefore, securing effective cooling performance is crucial for rapid charging.

[0010] Next, regarding thermal propagation control, if a thermal event occurs in any one of the multiple battery cells included in the battery pack, it is necessary to block the thermal propagation of this thermal event to other battery cells.

[0011] If heat propagation between battery cells is not properly suppressed, it can lead to thermal events in other battery cells within the battery pack, potentially causing more serious problems such as ignition or explosion of the battery pack. Furthermore, ignition or explosion occurring within the battery pack can cause significant damage to surrounding human lives and property. Therefore, such battery packs require a configuration capable of appropriately controlling the aforementioned thermal events and their propagation.

[0012] In summary, there is a growing demand for battery assemblies and battery packs equipped with effective cooling means for rapid charging and means to suppress heat propagation between battery cells. The problem to be solved

[0013] The problem that the present invention aims to solve is to provide a battery assembly having an effective cooling means for rapid charging and a means to suppress heat propagation between battery cells, and a battery pack including the same.

[0014] 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. means of solving the problem

[0015] 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 the edge of each of the battery cells and covering the edge of the battery cells; and a heat sink having at least one cooling plate disposed at least at one of the locations between the battery cells. A cell vent portion is formed in the cell frame at a portion corresponding to the lower portion of the battery cell.

[0016] The cell frame may include 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. The cell vent portion may be formed on the first frame.

[0017] A 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.

[0018] An adhesive member may be attached to the lower portion of the battery cell, excluding the portion corresponding to the cell vent portion.

[0019] As the adjacent cell frames are joined together, the battery cells located inside can be fixed.

[0020] 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 portion of the battery cells; and a lower frame that covers the lower portion of the battery cells.

[0021] A vent cover portion that opens at a pressure above a certain level may be formed on the lower frame.

[0022] The above vent cover part can cover the above cell vent part.

[0023] The venting gas generated in the battery cell can be discharged through the cell vent portion and the vent cover portion.

[0024] A refrigerant may flow inside the above cooling plate.

[0025] The battery cell and the cooling plate can be in surface contact.

[0026] A chamfer portion may be provided at one end of the above cooling plate.

[0027] The battery assembly may include at least one pad member disposed at at least one location among the battery cells.

[0028] Between the battery cells, the cooling plate or the pad member may be located.

[0029] A battery pack according to one embodiment of the present invention comprises: the battery assembly; and a pack frame that accommodates the battery assembly. The pack frame includes a bottom frame on which the battery assembly is placed and a venting space is provided.

[0030] While venting gas is being discharged from the battery cell, the cell vent portion may be in communication with the venting space of the bottom frame.

[0031] The heat sink may include a cooling tube connected to the cooling plate. The area occupied by the cooling tube along the height direction may overlap at least partially with the area occupied by the venting space along the height direction. Effects of the invention

[0032] According to embodiments of the present invention, surface cooling of the battery cells can be achieved by means of a cell frame covering the edges of the battery cells and a cooling plate disposed between the battery cells, thereby improving cooling performance.

[0033] In addition, when a thermal event occurs in a battery cell, high-temperature venting gases or particles emitted from the battery cell travel along a specific intended path through the cell vent provided in the cell frame. Accordingly, the propagation of a thermal event generated in a specific battery cell to other battery cells can be minimized.

[0034] 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. Brief explanation of the drawing

[0035] FIG. 1 is a perspective view of a battery assembly according to one embodiment of the present invention. Figure 2 is an exploded perspective view of the battery assembly of Figure 1. FIG. 3 is a perspective view showing the state in which a battery cell stack and a lower frame included in the battery assembly of FIG. 2 are combined. FIG. 4 is a perspective view showing the state in which the pad member is separated from the battery cell stack and lower frame of FIG. 3. 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. FIGS. 8 and FIGS. 9 are cross-sectional perspective views of a battery cell coupled to a cell frame. 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 the combined state of two cell frames. FIGS. 12 and FIGS. 13 are a perspective view and a front view showing heat sink and pad members according to one embodiment of the present invention. FIG. 14 is a front view showing a heat sink, pad members, and some cell frames. FIG. 15 is an exploded perspective view showing a battery cell, a cooling plate, and a pad member combined in a cell frame. FIG. 16 is a perspective view showing a heat sink according to one embodiment of the present invention. FIG. 17 is a perspective view showing one cooling plate and a cooling tube in the heat sink of FIG. 16. FIG. 18 is a perspective view showing 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. FIG. 21 is a perspective view taken from below showing the battery cell stack and the lower frame combined. FIG. 22 is a perspective view of a battery cell stack viewed from below. FIG. 23 is a cross-sectional perspective view showing the cut along the cutting line AA of FIG. 3. FIG. 24 is a partial drawing showing an enlarged view of section “B” of FIG. 23. FIG. 25 is an exploded perspective view showing a lower frame according to one 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 one embodiment of the present invention. FIG. 27 is a perspective view showing a battery pack according to one embodiment of the present invention. FIG. 28 is a perspective view showing the battery pack of FIG. 27 with the pack cover removed. FIG. 29 is a perspective view showing a pack frame included in the battery pack of FIG. 27. FIG. 30 is a perspective view showing a bottom frame included in the pack frame of FIG. 29. FIG. 31 is a perspective view showing vent plates arranged on the bottom frame of FIG. 30. FIG. 32 is a perspective view showing an inner frame and cover plates according to one embodiment of the present invention. FIG. 33 is a partial drawing showing an enlarged view of section “D” of FIG. 32. FIG. 34 is a perspective view of 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 drawing showing an outer frame hole, and FIG. 36 (b) is a partial drawing showing a venting device coupled to the outer frame hole. FIG. 37 is a partial cross-sectional view showing a portion of the cross-section cut along the cutting line E-E' of FIG. 27. 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. Specific details for implementing the invention

[0036] 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 present invention. The present invention may be embodied in various different forms and is not limited to the embodiments described herein.

[0037] To clearly explain the present invention, parts unrelated to the explanation have been omitted, and the same reference numerals are used for identical or similar components throughout the specification.

[0038] Furthermore, the size and thickness of each component shown in the drawings are depicted arbitrarily for convenience of explanation, and thus the present invention is not necessarily limited to what is illustrated. Thicknesses have been enlarged in the drawings to clearly represent various layers and regions. Additionally, for convenience of explanation, the thickness of some layers and regions has been exaggerated in the drawings.

[0039] Furthermore, when a part such as a layer, membrane, region, or plate is said to be "on" or "on" another part, this includes not only the case where it is "directly above" the other part, but also the case where there is another part in between. Conversely, when a part is said to be "directly above" another part, it means that there is no other part in between. Also, saying that a part is "on" or "on" a reference part means that it is located above or below the reference part, and does not necessarily mean that it is located "on" or "on" facing the opposite direction of gravity.

[0040] 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.

[0041] Additionally, throughout the specification, "planar" means when the subject part is viewed from above, and "cross-sectional" means when the cross-section obtained by vertically cutting the subject part is viewed from the side.

[0042] FIG. 1 is a perspective view of a battery assembly according to an 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 the state in which a battery cell stack and a lower frame included in the battery assembly of FIG. 2 are combined.

[0043] Referring to FIGS. 1 to 3, a battery assembly (100) according to one embodiment of the present invention comprises: a plurality of battery cells (110) stacked along one direction; cell frames (300) extending along the edge of each of the battery cells (110) and covering the edge of the battery cells (110); and a heat sink (400) having at least one cooling plate (410) disposed between at least one of the battery cells (110).

[0044] Specifically, a battery cell stack (120) can be formed by stacking the battery cells (110) along one direction while each of the battery cells (110) is covered by a cell frame (300). That is, a cell frame (300) is provided for each battery cell (110), so that the battery cells (110) and the cell frame (300) correspond one-to-one. For example, a battery cell stack (120) can 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.

[0045] 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), i.e., a battery cell stack (120), which are covered by a cell frame (300). The cell assembly frame (200) may include an upper frame (210) that covers the upper portion of the battery cells (110); and a lower frame (220) that covers the lower portion of the battery cells (110).

[0046] The upper frame (210) may include side portions (211) covering both sides according to the direction in which battery cells (110) are stacked in the battery cell stack (120), and a ceiling portion (212) covering the upper surface of the battery cell stack (120). In particular, the ceiling portion (212) may cover the upper portion of the cell frames (300) in the battery cell stack (120). The side portions (211) may extend downward from both sides facing the ceiling portion (212).

[0047] Meanwhile, the cell assembly frame (200) may include a mounting portion (200M) which is a part that fixes the battery assembly (100) to the pack frame described later. A mounting hole is formed in the mounting portion (200M), and a bolt member can pass through the mounting hole to be fastened to the pack frame described later. For example, the mounting portion (200M) may be provided on the side portion (211) of the upper frame (210), and there are no special limitations on the number or size thereof.

[0048] The lower frame (220) may include a first lower cover (221), a second lower cover (222), and a vent plate (223) located between the first lower cover (221) and the second lower cover (222). Additionally, the lower frame (220) may further include an adhesive portion (224) that bonds 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 this cell assembly frame may cover the upper surface, lower surface, and both sides 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, 26, etc.

[0049] FIG. 4 is a perspective view showing the state in which the pad member is separated from the battery cell stack and lower frame of FIG. 3. FIG. 5 is a perspective view showing battery cells and cell frames according to an 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 an embodiment of the present invention.

[0050] Referring to FIGS. 4 to 7, the battery cell (110) according to the present embodiment may be a battery cell of various types, and for example, as shown in FIGS. 5 to 7, the battery cell (110) according to the present embodiment may be a pouch-type battery cell. Although the following description focuses on a pouch-type battery cell, the battery cell (110) according to the present embodiment is not limited thereto and various types of battery cells may be applied.

[0051] 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 be in the shape of a rectangular sheet. The battery cell (110) may have a bottom portion (114a), a top portion (114b), and both ends (114c, 114d).

[0052] A battery cell (110) can be formed by housing an electrode assembly in a pouch case (114) of a laminate sheet comprising a resin layer and a metal layer, and then bonding the outer periphery of the pouch case (114). For example, the battery cell (110) may 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.

[0053] A battery cell (110) can be manufactured by bonding the two ends (114c, 114d) of a 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, a battery cell (110) according to one embodiment of the present invention has a total of three sealing portions (114s), and the sealing portions (114s) are sealed by a method such as fusion, and the remaining upper portion (114b) can be formed as a folding portion. That is, the battery cell (110) according to the present embodiment may 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 portions (114s). In FIG. 7, only the sealing portions (114s) formed on both ends (114c, 114d) of the pouch case (114) are shown, and the sealing portion on the bottom portion (114a) is not shown, but the sealing portion on the bottom portion (114a) is folded to one side after sealing is completed for space utilization. This will be explained again in FIG. 9.

[0054] The pouch case (114) of the laminate sheet may include an inner resin layer for sealing, a metal layer for preventing penetration of material, and an outermost resin layer. Based on the electrode assembly inside the pouch case (114), the inner resin layer may be located at the innermost position, the outer resin layer at the outermost position, and the metal layer may be located between the inner resin layer and the outer resin layer.

[0055] The outer resin layer may possess excellent tensile strength and weather resistance relative to its thickness and electrical insulation properties to protect the electrode assembly from the outside. This outer resin layer may include polyethylene terephthalate (PET) resin or nylon resin. The metal layer may prevent air, moisture, etc. from entering the interior of the pouch-type secondary battery. This metal layer may include aluminum (Al). The inner resin layers may be thermally fused together by applied heat and / or pressure while the electrode assembly is embedded. This inner resin layer may include casted polypropylene (CPP) or polypropylene (PP).

[0056] A pouch case (114) may be divided into two parts, and a concave-shaped storage portion may be formed in at least one of the two parts so that an electrode assembly can be seated thereon. Along the outer circumference of this storage portion, the inner resin layers of the two parts of the pouch case (114) may be bonded together to form a sealing portion (114s). In this way, the pouch case is sealed so that a battery cell (110), which is a pouch-type secondary battery, can be manufactured.

[0057] As described above, the battery cells (110) within the battery assembly (100) may be configured in multiple numbers. For example, multiple battery cells (110) may be stacked along one direction to form a battery cell stack (120) so that they can be electrically connected to each other. For example, multiple battery cells (110) may be stacked upright along a direction parallel to the X-axis. Accordingly, electrode leads (111) may protrude in a direction perpendicular to the direction in which the battery cells (110) are stacked. In a battery cell (110), one electrode lead (111) may protrude toward the Y-axis direction, and another electrode lead (111) may protrude toward the -Y-axis direction. If the battery cell has electrode leads (111) protruding in only one direction, the electrode leads (111) may protrude toward the Y-axis direction or the -Y-axis direction.

[0058] FIGS. 8 and 9 are cross-sectional perspective views of a battery cell coupled to a cell frame; specifically, FIG. 8 is a cross-sectional perspective view of the battery cell coupled to the cell frame cut along the xy plane, and FIG. 9 is a cross-sectional perspective view of the battery cell coupled to the cell frame cut along the xz plane. FIG. 10 is a perspective view showing a cell frame according to an embodiment of the present invention. FIG. 11 is a perspective view showing two cell frames coupled together.

[0059] 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 the cell frame (300) at a portion corresponding to the lower portion (114a) of the battery cell (110).

[0060] Specifically, the cell frame (300) may include a first frame (310) covering the lower portion (114a) of the battery cell (110); a second frame (320) covering the upper portion (114b) of the battery cell (110); and a third frame (330) and a fourth frame (340) covering the two ends (114c, 114d) of the battery cell (110), respectively. As described above, the battery cells (110) and the cell frame (300) correspond one-to-one, and each of the battery cells (110) can be covered by each of the cell frames (300).

[0061] The cell vent portion (300V) may be formed in the first frame (310) of the cell frame (300). Specifically, the cell vent portion (300V) may be a part that guides the discharge of high-temperature venting gas or particles generated from the battery cell (110) when a thermal event or thermal runaway occurs in any one of the battery cells (110). This cell vent portion (300V) may be provided in the central part of the first frame (310) that covers the lower part (114a) of the battery cell (110).

[0062] For example, the cell vent section (300V) may include a first section (300V1), a second section (300V2), and a third section (300V3). The first section (300V1), the second section (300V2), and the third section (300V3) may extend downward, and an open space may be formed between them. However, this is an exemplary structure of the cell vent section (300V), and it is sufficient that 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 restrictions on its shape.

[0063] 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 open in the downward direction, so high-temperature venting gas or particles generated from the battery cell (110) can be discharged downward through this 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 predetermined 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.

[0064] Meanwhile, referring to FIGS. 5 to 9, an adhesive member (130) may be attached to the lower portion (114a) of the battery cell (110), excluding the 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 sealing of the pouch case (114) is performed, and the upper portion (114b) of the battery cell (110) may not be a sealing portion but 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 discharged primarily through the sealing portion (114s) of the battery cell (110). That is, due to increased internal pressure, the sealing is released in some parts of the sealing portion (114s), and venting gases, etc., can be discharged through the released sealing portion (114s).

[0065] In the battery assembly (100) according to the present embodiment, the battery cell (110) can be arranged such that the lower portion (114a) of the battery cell (110) becomes the sealing portion (114s) and the upper portion (114b) of the battery cell (110) becomes the folding portion. Through this arrangement, a “bottom venting” structure that discharges venting gas and particles generated from the battery cell (110) in a downward direction can be more clearly implemented. FIG. 9 shows the sealing portion (114s) corresponding to the lower portion (114a) of the battery cell (110) folded for space utilization after the sealing is completed.

[0066] 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) in the downward direction. To this end, an adhesive member (130) may be attached to the lower portion (114a) of the battery cell (110), excluding the portion corresponding to the cell vent portion (300V). The adhesive member (130) may be, for example, an adhesive tape.

[0067] In the lower portion (114a) of the battery cell (110) where the adhesive member (130) is attached, the sealing degree is supplemented by the adhesive member (130), so the sealing is not released even if the internal pressure of the battery cell (110) increases. On the other hand, in the lower portion (114a) of the battery cell (110) where the adhesive member (130) is not attached, the sealing degree is relatively lower, so the sealing may be released before the portion where the adhesive member (130) is attached. Accordingly, the discharge of venting gas can be induced to the portion of the lower portion (114a) of the battery cell (110) corresponding to the cell vent portion (300V) (i.e., the portion without the adhesive member), and the venting gas can be discharged downward through the cell vent portion (300V).

[0069] Referring again to FIGS. 4, 5, 6, 10, and 11, in a battery cell stack (120) according to the present embodiment, adjacent cell frames (300) are joined together, and the battery cells (110) located therein can be fixed. There are no special limitations on the method of joining cell frames (300), but joining can be achieved through 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 an adjacent cell frame (300) is located. Cell frames (300) can be joined together in such a manner that the hook protrusion (300P) of one cell frame (300) is hook-joined to the hook groove (300G) of an adjacent cell frame (300). FIG. 11 illustrates such hook joining between two cell frames (300). As the connection between the hook protrusion (300P) and the hook groove (300G) is continuously formed for each adjacent cell frame (300), multiple cell frames (300) can all be connected.

[0070] 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). A battery cell stack (120) containing cell frames (300) in this manner is structurally more stable than a form in which only battery cells (110) are stacked without cell frames (300), and can withstand external vibrations or shocks well. In the case where only battery cells (110) are stacked without cell frames (300), there may be a problem where the battery cell stack cannot be maintained against external vibrations or shocks, causing the shape to collapse. Additionally, in the case of a battery cell stack (120) containing 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).

[0072] Hereinafter, the heat sink and pad members included in the battery assembly according to the present embodiment will be described in detail.

[0073] FIGS. 12 and 13 are a perspective view and a front view showing a heat sink and pad members according to an embodiment of the present invention. FIG. 14 is a front view showing a heat sink, pad members, and some cell frames. Specifically, FIG. 14 shows four cell frames (300) interposed between the cooling plates (410) of the heat sink (400) and the pad members (500). FIG. 15 is an exploded perspective view showing a battery cell, cooling plates, and pad members combined with a cell frame.

[0074] Referring to FIGS. 12 to 15, as previously described, 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 between at least one of the battery cells (110). A refrigerant may flow inside the cooling plate (410). Specifically, the cooling plate (410) has a refrigerant path, which is a space in which a refrigerant flows, and may come into contact with the battery cell (110).

[0075] Specifically, the battery cell (110) and the cooling plate (410) may be in surface contact. At least one surface of the battery cell (110) may be in contact with the cooling plate (410). More specifically, one surface of the cooling plate (410) may 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) may be in contact with the cooling plate (410), or both sides of the battery cell (110) may be in contact with the cooling plate (410). That is, at least one surface of the battery cell (110) may be in direct surface contact with the cooling plate (410).

[0076] The cooling plate (410) can cool the battery cell (110) in a plate-like shape. The refrigerant flowing inside the cooling plate (410) may be cooling water. The battery assembly (100) according to the present embodiment may have a water-cooled cooling structure.

[0077] 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 direct or indirect contact of this thermal resin layer 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 refrigerant flows is interposed between the battery cells (110) and contacts one side of the cell body (113, see FIG. 7) of the battery cells (110). Since one side of the cell body (113, see FIG. 7) of the battery cell (110) can come into contact with one side of the cooling plate (410), the cooling area is much larger, so there is an advantage of superior cooling performance compared to conventional battery assemblies.

[0078] Recently, quick charging has become a required feature in battery assemblies, but one of the problems with quick charging is the heat generated during the process. For quick charging, a cooling system is essential to manage the heat generated during the process to an appropriate level. When quick charging is applied to a battery assembly with a conventional edge cooling structure, the temperature difference between the upper and lower parts increases, and the quick charging efficiency inevitably decreases in the upper part, where the cooling effect is insufficient. On the other hand, in the case of the battery assembly (100) according to the present embodiment, the cooling plate (410) directly surface-cools the battery cells (110) by making surface contact with the battery cells (110), so it can have excellent cooling performance sufficient to control the heat generated during quick charging.

[0079] If surface cooling of the battery cells (110) can be performed within the battery assembly (100), there are no special limitations on the number or size of the cooling plates (410). The number of cooling plates (410) can be appropriately changed considering the size, capacity, heat generation amount, etc. of the battery assembly (100). Additionally, if it can cover 60% or more of the surface area of ​​one side of the battery cell (110), there are no special limitations on the area of ​​the cooling plates (410). However, the cooling plates (410) may be provided in multiple numbers within the battery assembly (100), and it is desirable to ensure that the number of cooling plates (410) is sufficient so that one side of all battery cells (110) can come into contact with the cooling plates (410).

[0080] 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 part of the battery cell (110). This terrace part 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 part, a slight gap may occur between the terrace part of the battery cell (110) and the cooling plate (410). To fill the gap between the terrace part of the battery cell (110) and the cooling plate (410), a spacer (700) may be additionally provided between the terrace part of the battery cell (110) and the cooling plate (410).

[0081] Meanwhile, referring again to FIGS. 12 to 15, the battery assembly according to the present embodiment may include at least one pad member (500) disposed at at least one location among the battery cells (110). The pad member (500) may be a foam-shaped member having thermal insulation. There are no special restrictions on the material of the pad member (500) as long as the pad member (500) has thermal insulation and a certain elasticity. For example, the pad member (500) may include a silicone material or an aerogel material.

[0082] 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 a battery cell stack (120), battery cells (110) are stacked while 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 shown in FIGS. 12 to 14, a cooling plate (410) and a pad member (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. A battery cell (110) coupled to the cell frame (300) may be interposed in the space (S, see FIG. 13) between the cooling plate (410) and the pad member (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 obscured by the cell frame (300), but the battery cell (110) is located inside the cell frame (300).

[0083] Accordingly, as illustrated in FIG. 15, in any 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 merely one example, and in other embodiments of the present invention, it is also possible for the cooling plates (410) to 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.

[0085] The structure of the heat sink according to the present embodiment will be described in detail below.

[0086] FIG. 16 is a perspective view showing a heat sink according to an embodiment of the present invention. FIG. 17 is a perspective view showing one cooling plate and a cooling tube in the heat sink of FIG. 16. FIG. 18 is a perspective view showing 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.

[0087] Referring to FIGS. 16 to 20, the heat sink (400) according to the present embodiment may include cooling plates (410) that surface-cool a battery cell (110) and a cooling tube (420) connected to the cooling plates (410).

[0088] First, the cooling plate (410) may include a first cooling cover (411), a second cooling cover (412), and a cooling center plate (413) located between the first cooling cover (411) and the second cooling cover (412). Along the -X-axis direction in the direction in which the battery cells (110) are stacked, the first cooling cover (411), the cooling center plate (413), and the second cooling cover (412) may be positioned in order.

[0089] A refrigerant path (CP), which is a path through which refrigerant flows, may be provided in the cooling central 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 can be completed. FIG. 19 is illustrated as an example in which the refrigerant path (CP) is depicted as a winding path, but there are no special restrictions 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) can be appropriately adjusted by considering the flow rate and flow rate of the refrigerant.

[0090] The cooling plate (410) may include an inlet (410N) and an outlet (410U) that are in communication with 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), 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).

[0091] The first cooling tube (421) and the second cooling tube (422) may be connected to a refrigerant circulation system (not shown) provided inside or outside the battery pack. Refrigerant traveling along the first cooling tube (421) from the refrigerant circulation system may flow into the refrigerant path (CP) through the inlet (410N) of the cooling plate (410) and flow inside the cooling plate (410). Subsequently, the refrigerant discharged from the refrigerant path (CP) through the outlet (410U) of the cooling plate (410) may flow along the second cooling tube (422) and then be recovered back into the refrigerant circulation system. Through the above process, a refrigerant circulation structure can be implemented within the battery assembly (100). Heat generated in the battery cells (110) inside the battery assembly (100) can be transferred to the refrigerant flowing into the refrigerant path (CP) of the cooling plate (410) and discharged to the outside of the battery assembly (100) along the second cooling tube (422). Subsequently, the refrigerant, which has been cooled again in the refrigerant circulation system, can be introduced back into the refrigerant path (CP) of the cooling plate (410) through the first cooling tube (421). That is, in the case of the battery assembly (100) according to the present embodiment, it may have a structure that discharges heat generated in the battery cells (110) through the refrigerant flowing along the heat sink (400).

[0092] 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 in which the thickness gradually narrows as it goes from one end of the cooling plate (410) toward the outer direction of the cooling plate (410).

[0093] 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 the gap between the battery cells (110). Since a chamfer (410CH) is provided at one end of the cooling plate (410), when the cooling plate (410) is assembled into the battery cell stack (120), the cooling plate (410) is easily inserted between the battery cells (110). The cooling plate (410) can be pushed in close contact between the battery cells (110), starting from the chamfer (410CH).

[0095] Referring again to FIGS. 2 through 6, the battery assembly (100) may further include a busbar (610) and a terminal busbar (620) connected to the electrode lead (111) of the battery cell (110). The busbar (610) and the terminal busbar (620) may be electrically connected to the electrode lead (111) of the battery cell (110). For example, the busbar (610) and the terminal busbar (620) may be joined to the electrode lead (111) by a welding method. The busbar (610) and the terminal busbar (620) may be placed 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).

[0096] Battery cells (110) can be electrically connected in series or parallel via these busbars (610).

[0097] The terminal busbar (620) may be electrically connected to the electrode leads (111) of some battery cells (110), and a portion of it may be exposed to the outside of the battery assembly (100). The battery assembly (100) may form a High Voltage (HV) connection with other battery assemblies or electrical components through this terminal busbar (620). Here, the HV connection refers to a connection that serves as a power source to supply power requiring high voltage, and means a connection between battery cells or between battery assemblies.

[0098] Meanwhile, although not specifically illustrated, the battery assembly (100) may include a connector. The connector (not illustrated) is a component for the LV (Low Voltage) connection of the battery assembly (100). An LV connection refers to an electrical connection that requires a relatively low voltage, such as a battery electrical component. For example, a sensing component (not illustrated) may sense voltage data of the battery cells (110) or temperature data inside the battery assembly (100), and a connector connected to the sensing component may transmit the sensed voltage data or temperature data to a BMS (Battery Management System) located outside the battery assembly (100). Therefore, a part of the connector may also be exposed to the outside of the battery assembly (100).

[0100] Hereinafter, the functions of the cell frame (300), the cooling plate (410) of the heat sink (400), and the pad member (500), etc., in the battery assembly (100) according to the present embodiment will be explained in more detail.

[0101] Referring together to FIGS. 5 to 19, the cell frame (300) according to the present embodiment extends along the edge of each battery cell (110) and covers the edge of the battery cells (110), so that one side of the cell body (113) of the battery cell (110) is not obscured by the cell frame (300) and is exposed. The cell frame (300) can stably fix the battery cells (110) and, at the same time, guide the one side 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 sufficient to control heat generation during rapid charging.

[0102] 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 propagation and the discharge of venting gas to occur in the direction of the surface, that is, in the direction in which the battery cells (110) are stacked, i.e., in the X-axis or -X-axis direction. Accordingly, high-temperature venting gas or particles caused by the thermal runaway of the battery cell (110) are highly likely to be discharged through the bottom part (114a), top part (114b), or both ends (114c, 114d) which are the edges of the battery cell (110). There is a high possibility that high-temperature venting gas or particles will be discharged as the sealing is released at the bottom part (114a) and both ends (114c, 114d) where the sealing part (114s) is provided. In particular, the sealing portion (114s) at both ends (114c, 114d) of the battery cell (110) where the electrode lead (111) protrudes is called the terrace part, and in conventional battery assemblies, the sealing is mainly released at this terrace part and venting gas is discharged.

[0103] 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 bottom part (114a), top part (114b), and both ends (114c, 114d) of the battery cell, the discharge of venting gas or particles through the edges of the battery cell (110) may be restricted. Instead, since a cell vent part (300V) that is open downward is provided in the part of the cell frame (300) according to the present embodiment that corresponds to the bottom part (114a) of the battery cell, 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 guided to be discharged only through this cell vent part (300V). That is, in the battery assembly (100) according to the present embodiment, directional venting in the downward direction, i.e., “bottom venting,” can be induced by a cell frame (300) equipped with a cell vent portion (300V). In addition, as previously described, venting to only the cell vent portion (300V) can be more clearly implemented by an adhesive member (130) attached to a portion of the lower part (114a) of the battery cell (110) excluding the portion corresponding to the cell vent portion (300V).

[0104] Meanwhile, as will be described later, when the battery assembly (100) is housed in the pack frame, the venting gas or particles discharged from the cell vent section (300V) can be discharged to the outside of the pack frame through the interior of the bottom frame of the pack frame. This will be described in detail later with reference to FIGS. 27 to 37.

[0105] In the battery assembly (100), there exists a high-voltage current path, such as the HV (High voltage) connection of the busbar (610) or terminal busbar (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 between battery assemblies. At this time, if high-temperature gas or particles resulting from a thermal event in 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 explosions and flames. In particular, the terrace section is a part adjacent to the electrode lead (111) and the busbar (610), and the venting gas discharged through the terrace section may be even more dangerous because it has a direct impact on the HV connection. On the other hand, in the case of the battery pack according to the present embodiment, as mentioned above, it has a structure of “bottom venting” through the cell vent section (300V), so high-temperature gas or particles resulting from a thermal event can be discharged in a downward direction. In particular, as will be described later, it can be discharged to the outside through the bottom frame of the pack frame. Therefore, there is no risk of high-temperature gases or particles coming into contact with high-voltage paths such as HV connections, and ultimately, safety against thermal runaway phenomena can be enhanced.

[0106] Meanwhile, as previously explained, 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 thermal runaway phenomenon generated in the battery cell (110) from spreading heat to adjacent battery cells (110). That is, the cooling plate (410) can achieve excellent cooling performance sufficient to control heat generation during rapid charging through a surface cooling structure, while simultaneously preventing thermal propagation between battery cells (110). In particular, the cooling plate (410) is configured to have a refrigerant flowing inside, which can lower the thermal runaway temperature of the battery cell (110), and is effective in preventing thermal propagation between battery cells (110) because it blocks the lateral direction. Likewise, the pad member (500) can also prevent thermal propagation between the battery cells (110). If the pad member (500) includes a material with excellent thermal insulation properties, it may be more effective in preventing thermal propagation.

[0107] Meanwhile, during the process of repeated charging and discharging, the internal electrolyte of the battery cells (110) decomposes and gas is generated, causing the battery cells (110) to swell, i.e., a swelling phenomenon may occur. 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 (a 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, it is possible to prevent the battery assembly (100) from deforming beyond its deformation limit due to the swelling of the battery cells (110). A cooling plate (410) in contact with the other side of the battery cell (110) can also absorb the swelling of the battery cell (110) to some extent.

[0109] Hereinafter, a vent plate and a vent cover portion according to one embodiment of the present invention will be described in detail.

[0110] FIG. 21 is a perspective view taken from below showing the battery cell stack and the lower frame combined. FIG. 22 is a perspective view taken from below showing the battery cell stack. That is, FIG. 22 shows the lower frame removed from FIG. 21. FIG. 23 is a cross-sectional perspective view taken along the cutting line AA of FIG. 3. FIG. 24 is a partial view taken by enlarging section “B” of FIG. 23. FIG. 25 is an exploded perspective view showing the 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 the view taken along the cutting line CC in FIG. 26 (a).

[0111] Referring to FIGS. 2, FIGS. 3 and FIGS. 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 part of the battery cells (110); and a lower frame (220) that covers the lower part of the battery cells (110).

[0112] A vent cover portion (220VC) that opens at a pressure above a certain level may be located below the cell vent portion (300V). For example, a vent cover portion (220VC) that opens at a pressure above a certain level 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) located between the first lower cover (221) and the second lower cover (222).

[0113] Along the direction from one end (114d) to the other end (114c) of the battery cell (110), a first lower cover (221), a vent plate (223), and a second lower cover (222) may be positioned in sequence. That is, the vent plate (223) may be positioned at a location corresponding to the cell vent portion (300V) of the cell frame (300), and a vent cover portion (220VC) may be provided on this vent plate (223).

[0114] The vent cover portion (220VC) can cover the cell vent portion (300V) of the cell frame (300). Specifically, the vent cover portion (220VC) can cover the lower part of the cell vent portion (300V) of the cell frame (300). The vent plate (223) including the vent cover portion (220VC) may include a refractory material. For example, the vent plate (223) may include MICA material.

[0115] The vent cover portion (220VC) may be a structure that opens when pressure exceeding a certain level is applied due to the venting gas discharged through the cell vent portion (300V). If this function is performed, there are no special restrictions on the structure of the vent cover portion (220VC), nor are there special restrictions on the criteria for the opening pressure. The criteria for the opening pressure may vary depending on the number, size, composition, etc. of the battery cells included in the battery assembly.

[0116] For example, the vent cover portion (220VC) according to the present embodiment may include a connecting portion (220C) which is a part connected to the vent plate (223), and a slit (220S) in the shape of a hole may be formed on the remaining three sides excluding the connecting portion (220C). That is, by forming slits (220S) on the remaining three sides excluding the connecting portion (220C) from the vent plate (223), the vent cover portion (220VC) can be provided on the vent plate (223). There is no particular limit to the number of vent cover portions (220VC) provided on the vent plate (223), but for example, the number of vent cover portions (220VC) may be equal to the number of cell vent portions (300V) in the battery cell stack (120), and each of the vent cover portions (220VC) may correspond one-to-one with each of the cell vent portions (300V).

[0117] Normally, this vent cover portion (220VC) covers the lower part of the cell vent portion (300V), but when venting gas is discharged from the battery cell (110) and a pressure greater than a certain amount is applied to the vent cover portion (220VC), the vent cover portion (220VC) can be bent in the opposite direction to where the cell vent portion (300V) is located, and the vent cover portion (220VC) can be opened. Accordingly, the venting gas generated from the battery cell can be discharged through the cell vent portion (300V) and the vent cover portion (220VC).

[0118] 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 part of the cell frame (300), that is, the first frame (310) of the cell frame (300), through the adhesive portion (224). Because the adhesive portion (224) is attached to the edge of the vent plate (223), venting gas or particles discharged from the cell vent portion (300V) may be prevented from leaking out to a part other than the vent cover portion (220VC).

[0120] Additionally, with reference 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 edge of the cooling plate (410) to face the cell vent portion (300V).

[0121] Additionally, the pad member (500) may include a pad member protrusion (500P) that protrudes in a shape corresponding to the cell vent portion (300V) of the cell frame (300). The pad member protrusion (500P) may protrude downward from the lower edge of the pad member (500) to face the cell vent portion (300V).

[0122] 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 the portion facing the third portion (300V3) may be open without other members.

[0123] At this time, a cooling plate (410) or a pad member (500) may be located between the battery cells (110), and a cooling plate protrusion (410P) or a pad member protrusion (500P) may be located in the portion facing the third portion (300V3) of the cell vent portion (300V).

[0124] Specifically, as illustrated in FIG. 24, a pad member protrusion (500P) may be located opposite the third part (300V3) of one cell vent (300V), and a cooling plate protrusion (410P) may be located opposite the third part (300V3) of another cell vent (300V) adjacent thereto.

[0125] A first part (300V1) and a second part (300V2) of the cell vent portion (300V) may come into contact with either the cooling plate protrusion (410P) or the pad member protrusion (500P), thereby forming a venting path in the cell vent portion (300V). That is, the space enclosed 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) may become a venting path (VP, see FIG. 24) through which venting gas passes. Additionally, the lower part of the venting path (VP) may be blocked by the vent cover portion (220VC) of the vent plate (223). Normally, the venting path (VP) is blocked by the vent cover part (220VC), but when a pressure greater than a certain amount is applied to the vent cover part (220VC), the vent cover part (220VC) bends downward, and the venting path (VP) can be opened. Venting gas generated from the battery cell (110) can be discharged downward through the venting path (VP) of the cell vent part (300V).

[0126] 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). This upper frame (210) can protect the battery cell stack (120) and control swelling of the battery cells (110). Additionally, 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) can block the leaking venting gas from spreading to the outside of the battery assembly (100).

[0128] Hereinafter, a battery pack according to one embodiment of the present invention will be described in detail.

[0129] FIG. 27 is a perspective view showing a battery pack according to an embodiment of the present invention. FIG. 28 is a perspective view showing the battery pack of FIG. 27 with the pack cover removed. FIG. 29 is a perspective view showing a pack frame included in the battery pack of FIG. 27. FIG. 30 is a perspective view showing a bottom frame included in the pack frame of FIG. 29.

[0130] Referring to FIGS. 27 to 30, a battery pack (1000) according to one embodiment of the present invention comprises: a battery assembly (100); and a pack frame (1100) that accommodates the battery assembly (100). The pack frame (1100) includes a bottom frame (1200) on which the battery assembly (100) is placed and which has a venting space (VS). FIG. 27 illustrates a battery pack (1000) in which six battery assemblies (100) are placed on the bottom frame (1200).

[0131] The pack frame (1100) may include a side frame (1300) that extends 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), which is rectangular in shape. A storage space with an open top is provided by the bottom frame (1200) and the side frame (1300), and a battery assembly (100) may be placed in this storage space. After the battery assembly (100) is placed in the storage space, a pack cover (1400) may cover the open top of the storage space. The pack cover (1400) can be joined to the side frame (1300) of the pack frame (1100), and, for example, a welded joint or a joint using an adhesive may be applied. The battery assembly (100) can be sealed by the pack frame (1100) and the pack cover (1400). Additionally, a gasket may be interposed between the pack cover (1400) and the side frame (1300) to enhance sealing performance.

[0132] 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, mounting beams (1300M) formed on the side frame (1300) are illustrated in FIGS. 27 to 29. The mounting beam (1300M) can be utilized when mounting the battery pack (1000) to a device. For example, when mounting the battery pack (1000) to a vehicle device, the mounting beam (1300M) can be fixed to the chassis of the vehicle.

[0133] Additionally, according to the present embodiment, the battery pack (1000) may include a vertical beam (1800) located on a floor frame (1200) and partitioning the space where the battery assemblies (100) are located. For example, FIGS. 28 and 29 show three vertical beams (1800) that divide the storage space where six battery assemblies (100) are placed into three zones.

[0135] FIG. 31 is a perspective view showing vent plates arranged on the bottom frame of FIG. 30. That is, other parts of the battery assembly are omitted from the illustration, and only the arrangement of the vent plate (223) of the battery assembly on the bottom frame (1200) is shown in FIG. 31.

[0136] Referring to FIGS. 21, 22, 30, and 31, the bottom frame (1200) is provided with a venting space (VS) through which venting gas and particles, etc., discharged from the cell vent section (300V) can move. The cell vent section (300V) of the cell frame (300) can be in communication with the venting space (VS) of the bottom frame (1200). Specifically, while venting gas is discharged from the battery cell (110) due to thermal runaway in the battery cell (110), the cell vent section (300V) can be in communication with the venting space (VS) of the bottom frame (1200). Accordingly, the venting gas can move from the cell vent section (300V) to the venting space (VS) of the bottom frame (1200).

[0137] More specifically, due to the cell vent section (300V) covering the lower part of the cell vent section (300V) of the cell frame (300), the cell vent section (300V) and the venting space (VS) of the bottom frame (1200) may not be in communication under normal circumstances. However, once the vent cover section (220VC) is opened due to the venting gas discharged through the cell vent section (300V), the cell vent section (300V) and the venting space (VS) of the bottom frame (1200) become in communication, allowing the venting gas to move from the cell vent section (300V) to the venting space (VS) of the bottom frame (1200).

[0138] 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 a bottom frame (1200). If high-temperature venting gas or particles resulting from a thermal event in the battery cell (110) come into contact with a high-voltage path such as an HV connection, a short circuit or arc discharge may occur, which may lead to additional explosions and flames. On the other hand, in the case of the battery pack (1000) according to the present embodiment, as mentioned above, because it has a “bottom venting” structure, high-temperature venting gas or particles resulting from a thermal event are discharged downward, that is, toward the bottom frame (1200). Therefore, there is no risk of high-temperature venting gas or particles coming into contact with a high-voltage path such as an HV connection, and ultimately, safety against thermal runaway phenomena can be increased.

[0140] Below, as an example, the detailed structure of the floor frame (1200) will be described in detail.

[0141] FIG. 32 is a perspective view showing an inner frame and cover plates according to an embodiment of the present invention. FIG. 33 is a partial view showing an enlarged view of section “D” of FIG. 32.

[0142] Referring together to FIGS. 28 to 33, a bottom frame (1200) according to one embodiment of the present invention may include an outer frame (1210) and an inner frame (1220) located on the upper part of the outer frame (1210). The outer frame (1210) may be a plate located at the bottom of the battery pack (1000), and such an outer frame (1210) may be combined with a side frame (1300).

[0143] The inner frame (1220) is a plate-shaped member, but may include a concave portion (1221) and a convex portion (1222). Along the Y-axis direction in the inner frame (1220), the concave portion (1221) and the convex portion (1222) may be arranged alternately. Meanwhile, to form a venting space (VS), a cover plate (1500), etc., may be attached to both sides of the inner frame (1220). The inner frame (1220) and the cover plate (1500) may be joined by a method such as welding.

[0144] The venting space (VS) according to the present embodiment may include a first venting space (VS1) and a second venting space (VS2). Specifically, the portion of the concave part (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, as the vent cover part (220VC) is opened, the venting gas discharged from the cell vent part (300V) can move to the first venting space (VS1).

[0145] Additionally, the portion of the inner frame (1220) that is surrounded by the cover plate (1500) may correspond to the second venting space. Furthermore, the inner frame (1220) may include a plurality of filtration 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) can move to the second venting space (VS2) through the filtration holes (1220H). Particles, ash, byproducts, etc. contained in the high-temperature venting gas (VG) can be filtered out primarily as they pass through these filtration 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 by connecting the first venting space (VS1) and the second venting space (VS2) through a filter hole (1220H), the function of primarily filtering high-temperature venting gas (VG) can be achieved.

[0146] Meanwhile, a gas shield (1600) may be disposed in the recess (1221) of the inner frame (1220). Specifically, in adjacent battery assemblies (100) along the X-axis direction, a gas shield (1600) may be disposed in the recess (1221) 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). With this gas shield (1600), it is possible to block the backflow of venting gas discharged from one battery assembly (100) to the first venting space (VS1) located below the 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 battery assemblies (100) is minimized, and explosion and structural collapse of the battery pack can be prevented. The gas shield (1600) may be located at a position corresponding to the vertical beam (1800) described above.

[0148] FIG. 34 is a perspective view of a bottom frame according to an embodiment of the present invention with a portion of the inner frame removed. FIG. 35 is a perspective view of an outer frame and routing plates according to an 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.

[0149] Referring to FIGS. 32 through 36 together, a routing plate (1700) may be positioned inside the convex portion (1222) of the inner frame (1220), that is, 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).

[0150] A battery pack (1000) may include a venting device (1900) provided in a pack frame (1100). For example, an outer frame hole (1210H) may be formed in an 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 component or mechanism provided to discharge venting gas, etc. For example, the venting device (1900) may be a valve structure that opens or ruptures when the internal pressure exceeds a certain level.

[0151] At this time, the outer frame hole (1210H) and the venting device (1900) may be located in the internal space of the routing plate (1700). Accordingly, the venting gas (VG) introduced into the second venting space (VS2) through the filtration hole (1220H) as in FIG. 33 may be bent in multiple directions while moving into the interior of the routing plate (1700) as shown in FIG. 34.

[0152] In this way, as a 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 extended venting path and bend several times along the path. While the venting gas (VG) flows along the path extended by the routing plate (1700), the temperature of the venting gas (VG) or particles can be lowered. Therefore, it is possible to prevent the venting gas (VG) or particles from triggering an explosion. Additionally, as the path of the venting gas (VG) is extended, oxygen introduced from the outside of the battery pack (1000) is blocked from coming into contact with the venting gas, etc., thereby preventing an explosion from occurring. Furthermore, large particles can be filtered out in the extended path.

[0153] FIG. 37 is a partial cross-sectional view showing a portion of the cross-section cut along the cutting line E-E' of FIG. 27.

[0154] 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. FIG. 37 shows, as an example, that 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 in part.

[0155] 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 lead (111) protrudes 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 lead (111) protrudes 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.

[0156] As described above, the cooling tube (420) may be configured to supply and discharge refrigerant to the cooling plates (410) of the heat sink (400). Additionally, the cell vent section (300V) of the cell frame (300) may be in communication with 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 section (300V) of the cell frame (300). The venting gas may flow along the venting space (VS) and finally 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 the concave portion (1221) and the 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.

[0157] In this embodiment, the cooling tube (420) for supplying and discharging refrigerant and the venting space (VS), which is a path for venting gas to be discharged from the bottom frame (1200), can be arranged so that the areas occupied along the height direction overlap each other. For a directional venting structure, a venting space (VS), which is a space for venting gas to be discharged, is provided in the bottom frame (1200), and the remaining space in the bottom frame (1200) other than the venting space (VS) can be utilized as a space for supplying refrigerant to the cooling plates (410). The remaining space in the bottom frame (1200) other than the venting space (VS) can be utilized as a space for arranging the cooling tube (420). Since the cooling tube (420) and the venting space (VS) are located together with respect to the height direction, the space utilization in the height direction of the battery pack (1000) can be increased. This can lead to a reduction in the weight of the battery pack (1000) and an increase in the battery capacity of the battery pack (1000).

[0158] Meanwhile, the area (A1) occupied by the cooling tube (420) along the height direction may overlap at least partially with the cell vent portion (300V) of the cell frame (300). In the present invention, there are no separate limitations 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 located between the first cooling tube (421) and the second cooling tube (422). Accordingly, the cooling plate protrusion (410P) and the pad member protrusion (500P) may also be located between the first cooling tube (421) and the second cooling tube (422) in correspondence with the position of the cell vent portion (300V).

[0159] 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.

[0160] Referring to FIG. 38, in another embodiment of the present invention, cell vent sections (300V) may be provided in plurality, and cooling tubes (420) may be located between the cell vent sections (300V). The cooling tubes (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 located between the plurality of cell vent sections (300V).

[0161] Each of the first cooling tube (421) and the second cooling tube (422) can be connected to the inlet (410N) and outlet (410U) of the cooling plate (410). The cooling plate protrusions (410P) and pad member protrusions (500P) may also be provided in multiple numbers corresponding to the location of the cell vent portion (300V). The cooling tube (420) may be located between the cooling plate protrusions (410P) and between the pad member protrusions (500P).

[0162] In the present invention, the cell vent portion (300V) and the cooling tube (420) may overlap at least partially in the area occupied along the height direction. The cell vent portion (300V) and the cooling tube (420) may be provided in various ways without any separate limitations on their position or number.

[0163] In this embodiment, terms indicating directions such as front, back, left, right, up, and down have been used; however, these terms are for convenience of explanation only and may vary depending on the location of the object or the observer.

[0164] One or more battery assemblies according to the embodiment described above 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.

[0165] The above battery assembly or battery pack can be applied to various devices. Specifically, it can be applied to means of transportation such as electric bicycles, electric vehicles, and hybrids, or to Energy Storage Systems (ESS), but is not limited thereto and can be applied to various devices capable of using secondary batteries.

[0166] 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. Explanation of the symbols

[0167] 100: Battery assembly 110: Battery cell 200: Cell Assembly Frame 300: Cell Frame 300V: Cell vent 400: Heat sink 410: Cooling plate 500: Pad missing 1000: Battery pack 1100: Pack Frame 1200: Floor frame 1300: Side frame 1400: Pack Cover

Claims

Claim 1 A battery assembly comprising: a plurality of battery cells stacked along one direction; cell frames extending along the edge of each of the battery cells and covering the edge of the battery cells; and a heat sink having at least one cooling plate disposed between at least one of the battery cells; wherein the cell frames include a first frame covering the bottom portion of the battery cell; a second frame covering the top portion of the battery cell; and a third frame and a fourth frame covering both ends of the battery cell, respectively, and are open along the direction in which the battery cells are stacked, wherein a cell vent portion is formed in the first frame among the cell frames, wherein the cell vent portion is open, and at least a portion of the bottom portion of the battery cell corresponding to the cell vent portion is not covered by the first frame. Claim 2 delete Claim 3 A battery assembly according to claim 1, wherein a cell frame is provided for each of the battery cells, and the battery cells and the cell frame correspond one-to-one. Claim 4 A battery assembly according to claim 1, wherein an adhesive member is attached to a portion of the lower part of the battery cell excluding the portion corresponding to the cell vent portion. Claim 5 A battery assembly in which adjacent cell frames are joined together and the battery cells located therein are fixed. Claim 6 A battery assembly according to claim 1, comprising a cell assembly frame for housing the battery cells, wherein the cell assembly frame comprises: an upper frame covering the upper portion of the battery cells; and a lower frame covering the lower portion of the battery cells. Claim 7 A battery assembly according to claim 6, wherein a vent cover portion that opens at a pressure above a certain level is formed on the lower frame. Claim 8 In claim 7, a battery assembly in which the vent cover portion covers the cell vent portion. Claim 9 In claim 7, the venting gas generated in the battery cell is discharged through the cell vent portion and the vent cover portion of the battery assembly. Claim 10 A battery assembly in which a refrigerant flows inside the cooling plate in claim 1. Claim 11 In claim 1, the battery assembly in which the battery cell and the cooling plate are in surface contact. Claim 12 A battery assembly according to claim 1, wherein a chamfer portion is provided at one end of the cooling plate. Claim 13 A battery assembly comprising at least one pad member disposed at at least one location among the battery cells in claim 1. Claim 14 In paragraph 13, a battery assembly in which the cooling plate or the pad member is located between the battery cells. Claim 15 A battery pack comprising: a battery assembly according to claim 1; a pack frame housing the battery assembly; wherein the pack frame comprises a bottom frame on which the battery assembly is placed and a venting space is provided. Claim 16 A battery pack according to claim 15, wherein the cell vent portion communicates with the venting space of the bottom frame while the venting gas is discharged from the battery cell. Claim 17 In paragraph 15, the heat sink comprises a cooling tube connected to the cooling plate, and the area occupied by the cooling tube along the height direction overlaps at least partially with the area occupied by the venting space along the height direction, in a battery pack.

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