Battery packs and devices containing them

Abstract

A battery pack according to one aspect of the present invention includes a plurality of cell units arranged in a line in one direction, and a pack case housing the plurality of cell units, the cell unit including at least one battery cell and a cell cover covering a portion of the battery cell, the cell cover having an upper portion inclined.

Description

[Technical Field]

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0089758 filed on July 20, 2022 and Korean Patent Application No. 10-2023-0090048 filed on July 11, 2023, and all contents disclosed in the documents of said Korean patent applications are incorporated herein by reference.

[0002] The present invention relates to a battery pack and a device including the same, and more particularly to a battery pack having high energy density and improved safety against thermal runaway, and a device including the same. [Background technology]

[0003] In recent years, the demand for portable electronic products such as laptops, video cameras, and mobile phones has increased dramatically, and the development of electric vehicles, energy storage batteries, robots, satellites, etc. has been gaining momentum. As a result, research into high-performance secondary batteries that can be repeatedly charged and discharged is being actively conducted.

[0004] Currently commercially available secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, and lithium secondary batteries. Of these, lithium secondary batteries are attracting attention due to their advantages of almost no memory effect compared to nickel-based secondary batteries, free charging and discharging, extremely low self-discharge rate, and high energy density.

[0005] Such lithium secondary batteries mainly use lithium oxide and carbon materials as positive and negative electrode active materials, respectively, and include a positive electrode plate and a negative electrode plate coated with the positive electrode active material and the negative electrode active material, an electrode assembly in which the positive electrode plate and the negative electrode plate are disposed with a separator therebetween, and an exterior material that hermetically houses the electrode assembly together with an electrolyte.

[0006] Meanwhile, lithium secondary batteries can be classified into can-type secondary batteries, in which an electrode assembly is housed in a metal can, and pouch-type secondary batteries, in which an electrode assembly is housed in an aluminum laminate sheet pouch, depending on the shape of the battery case. Can-type secondary batteries can also be classified into cylindrical batteries and prismatic batteries depending on the shape of the metal can.

[0007] Here, a pouch-type secondary battery is formed by enclosing an electrode assembly formed by stacking and winding a positive electrode, a negative electrode, and a separator in a case sheet and sealing the periphery of the sheet by heat sealing, etc. Also, electrode tabs drawn from each electrode included in the electrode assembly are connected to electrode leads, and portions of the electrode leads may protrude outside the periphery of the sheet.

[0008] As such, pouch-type secondary batteries have the flexibility to be configured in various shapes, and also have the advantage of being able to realize a secondary battery with the same capacity with a smaller volume and mass.

[0009] The lithium secondary battery can be used in the form of a battery module or a battery pack including a plurality of battery cells to provide high voltage and high current. The battery module can be provided in the form of including a plurality of battery cells inside a module case, and the battery pack can be provided in the form of including at least one such battery module.

[0010] One of the most important issues in such a battery pack configuration is safety. In particular, if a thermal event occurs in one of the multiple battery cells included in the battery pack, it is necessary to suppress the propagation of such an event to other battery cells. If thermal propagation between battery cells is not properly suppressed, this may lead to a thermal event in other battery cells included in the battery pack, which may result in a fire or explosion of the battery pack. Furthermore, a fire or explosion occurring in the battery pack may cause significant damage to surrounding lives and property. Therefore, a configuration that can appropriately control the above-mentioned thermal event is required for such a battery pack. Summary of the Invention [Problem to be solved by the invention]

[0011] The present invention has been made to solve these problems, and an object of the present invention is to provide a battery pack and device with improved safety by minimizing chain fires even when a thermal runaway phenomenon occurs. [Means for solving the problem]

[0012] A battery pack according to one aspect of the present invention includes a plurality of cell units arranged in a line, and a pack case that houses the plurality of cell units, the cell units including at least one battery cell and a cell cover that covers a portion of the battery cell, the cell cover having a sloped upper portion.

[0013] The cell cover may have a width at its periphery greater than a width at its center.

[0014] The cell cover may have a shape that is inclined upward toward an end in the length direction.

[0015] The battery cells may be vertically arranged such that one peripheral edge corresponds to a bottom surface of the pack case, and the cell covers may cover upper peripheral edges of the vertically arranged battery cells and leave lower peripheral edges of the battery cells open.

[0016] The cell cover may include a second surface and a third surface arranged parallel to one surface of the battery cell, and a first surface extending between the second surface and the third surface, and a cross section of the cell cover may have an n-shape.

[0017] The second surface may include a second central portion and a second peripheral portion, and the length value of the width of the second central portion may be smaller than the length value of the width of the second peripheral portion.

[0018] The upper peripheral edge of the second surface may have a shape that slopes upward toward an end of the second surface in the length direction.

[0019] The cross section of the first surface in the width direction may have a shape that slopes upward toward the end in the length direction.

[0020] The cell cover may include a fourth surface extending between the first surface, the second surface, and the third surface.

[0021] The fourth surface may partially cover an open longitudinal end of the cell cover.

[0022] A vent hole communicating with the outside may be formed in the bottom surface of the pack case.

[0023] The venting holes may be located at positions corresponding to the longitudinal ends of the cell units.

[0024] The venting holes may be plural, and the plural venting holes may be arranged in a straight line.

[0025] A device according to another aspect of the present invention includes at least one battery pack as described above. [Effects of the Invention]

[0026] According to one aspect of the present invention, a plurality of pouch-type battery cells can be stably housed inside a case without the need for a stacking frame such as a plastic cartridge or a separate module case.

[0027] Furthermore, according to one aspect of the present invention, a pouch-type battery cell having a flexible material case can be easily made into a rigid shape, so that a configuration in which the battery cells are directly stacked inside the case can be more easily realized.

[0028] Furthermore, according to one aspect of the present invention, safety against gases generated in the cells can be improved. In particular, according to one embodiment of the present invention, a directional venting structure against gases and flames can be realized, and the gas exhaust direction can be controlled.

[0029] Furthermore, according to one embodiment of the present invention, the energy density, ease of assembly, cooling performance, and the like of the battery pack can be improved.

[0030] In addition, the present invention can have various other effects, which will be described in each embodiment, or effects that can be easily guessed by a person skilled in the art will not be described. [Brief explanation of the drawings]

[0031] [Figure 1] FIG. 2 is a perspective view of a cell unit according to an embodiment of the present invention. [Figure 2] 1 is a perspective view of a battery cell according to an embodiment of the present invention; [Figure 3] 2 is a diagram showing a part of the cell unit according to FIG. 1; [Figure 4] 2 is a view showing the front or rear of the cell unit shown in FIG. 1; [Figure 5]2 is a side view of the cell unit shown in FIG. 1; [Figure 6] 1 is a diagram showing a gas venting path when a thermal event occurs in a battery cell included in a cell unit of the present embodiment. [Figure 7] 1 is a view showing a pack case of a battery pack according to an embodiment of the present invention; [Figure 8] 8 is an enlarged view of a portion AA in FIG. 7. [Figure 9] 1 is a diagram illustrating a schematic view of directional venting of a battery pack according to an embodiment of the present invention. [Figure 10] 1 is a diagram illustrating a schematic view of directional venting of a battery pack according to an embodiment of the present invention. [Figure 11] 1 is a diagram illustrating a state in which a case is provided for a plurality of cell units according to an embodiment of the present invention; [Figure 12] 12 is an enlarged view of the underside of the case shown in FIG. 11. DETAILED DESCRIPTION OF THE INVENTION

[0032] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. The terms and phrases used in this specification and claims should not be construed as being limited to their ordinary or dictionary meanings, but should be construed in a way that is consistent with the technical concept of the present invention, based on the principle that the inventor can appropriately define the concept of the term in order to best describe his or her invention. Therefore, it should be understood that the embodiments described in this specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention and do not represent the entire technical concept of the present invention, and that various equivalents and modifications may exist as of the time of filing this application.

[0033] In the drawings, the size of each component or specific parts constituting the component may be exaggerated, omitted, or illustrated schematically for convenience and clarity of description. Therefore, the size of each component does not completely reflect the actual size. If it is determined that a detailed description of related known functions or configurations may unnecessarily obscure the gist of the present invention, such description will be omitted.

[0034] Furthermore, when a layer, film, region, plate, or other portion is said to be "on" or "above" another portion, this includes not only the case where the layer, film, region, plate, or other portion is "directly above" the other portion, but also the case where there is another portion in between. Conversely, when a portion is said to be "directly above" another portion, it means that there is no other portion in between. Furthermore, being "on" or "above" a reference portion means being located above or below the reference portion, and does not necessarily mean being located "on" or "above" the direction opposite to gravity. Meanwhile, just as describing something as being "on" or "above" another portion, describing something as being "below" or "below" another portion can also be understood with reference to the above content.

[0035] Furthermore, throughout the specification, when a part is said to "comprise" a certain element, this means that it may further include other elements, not excluding other elements, unless otherwise specified.

[0036] Also, throughout the specification, "in a plane" means when the subject part is viewed from above, and "in cross section" means when the subject part is cut vertically and viewed from the side.

[0037] A cell unit according to an embodiment of the present invention will now be described.

[0038] FIG. 1 is a perspective view of a cell unit according to an embodiment of the present invention. FIG. 2 is a perspective view of a battery cell according to an embodiment of the present invention. FIG. 3 is a view showing a portion of the cell unit according to FIG. 1. FIG. 4 is a view showing the front or rear of the cell unit according to FIG. 1. FIG. 5 is a view showing a side of the cell unit according to FIG. 1. FIG. 6 is a view showing a gas venting path when a thermal event occurs in a battery cell included in the cell unit of this embodiment.

[0039] 1 to 6, a cell unit 100 according to an embodiment of the present invention may include a battery cell 110 in which an electrode assembly is housed while being immersed in an electrolyte, and a cell cover 200 that covers a portion of the battery cell 110. The cell unit 100 may be a minimum unit that protects the battery cell 110.

[0040] Prior to the explanation, the cell unit 100 may have a hexahedral shape having a horizontal (length), vertical (width), and thickness, where the vertical direction may be the X-axis, the horizontal direction may be the Z-axis, and the thickness direction may be the Y-axis. Furthermore, when the cell units 100 are arranged upright as shown in the figure, the horizontal direction (Z-axis direction) may also be referred to as the height direction. Multiple cell units 100 may be arranged consecutively along the thickness direction (Y-axis direction), which may also be referred to as the stacking direction of the cell units 100.

[0041] Here, the two surfaces that face each other in the length direction (X-axis direction) of the cell unit 100 can be referred to as the front and rear surfaces, the two surfaces that face each other in the thickness direction (Y-axis direction) of the cell unit 100 can be referred to as the side surfaces, and the two surfaces that face each other in the width direction (Z-axis direction) of the cell unit 100 can be referred to as the top and bottom surfaces.

[0042] 2, the battery cell 110 of this embodiment may be a pouch-type battery cell that can maximize the number of cells stacked per unit area. A pouch-type battery cell may be manufactured by placing an electrode assembly including a positive electrode, a negative electrode, and a separator in a cell case made of a laminate sheet, and then heat-sealing the sealing portion of the cell case. However, it is clear that battery cells do not necessarily have to be provided in a pouch-type battery cell, and that they may be provided in a prismatic, cylindrical, or other various shapes as long as the storage capacity required by the device to be installed can be achieved.

[0043] The battery cell 110 may include two electrode leads 111 and 112. Each of the electrode leads 111 and 112 may be positioned to protrude in one direction from one peripheral edge of the cell casing 101. The electrode leads 111 and 112 may be positioned to protrude from one side of the peripheral edge of the battery cell 110 where the sealing portion 130 is formed. One end of the electrode leads 111 and 112 may be positioned inside the battery cell 110 and electrically connected to the positive or negative electrode of the electrode assembly, and the other end of the electrode leads 111 and 112 may be led out of the battery cell 110 and electrically connected to another member, for example, a bus bar.

[0044] The battery cell 110 may include a receiving portion 120 that receives the electrode assembly and a sealing portion 130 formed on the periphery of the battery cell 110 to seal the electrode assembly. In the case of a pouch-type battery cell, the battery cell may be manufactured by receiving the electrode assembly in the cell case 101 and then sealing the periphery of the cell case 101 located outside the electrode assembly. When forming the battery cell 110 by receiving the electrode assembly in the inner space formed by folding the cell case 101 and sealing the peripheries of the three open sides, the sealing portion 130 may be formed on three of the four peripheries of the cell case 101, and in this case, the remaining periphery may be referred to as an unsealed portion 132. However, unlike the above, all four peripheries of the cell case may be heat-sealed to manufacture the battery cell 110. In this case, the sealing portion 130 may be formed on all four peripheries of the battery cell 110.

[0045] As shown in FIG. 2 , the battery cell 110 may have a hexahedral shape having a width (length), a height (width), and a thickness, where the length direction may be the X-axis, the width direction may be the Z-axis, and the thickness direction may be the Y-axis. Based on the hexahedral shape, the battery cell 110 may be described as including two faces (faces on the XZ plane) corresponding to the receiving portion 120 and four faces located on the periphery of the receiving portion 120. However, in the case of a pouch-type battery cell 110, because the thickness of the sealing portion 130 formed by thermal sealing is small, for convenience of explanation, the battery cell 110 will be described below as having two faces corresponding to the receiving portion 120 and four edges located outside the receiving portion 120. In this case, when the battery cell 110 is arranged upright along the Z-axis so that one face thereof is perpendicular to the ground, the edge on the +Z axis may be described as the upper edge, and the edge on the −Z axis may be described as the lower edge.

[0046] In this embodiment, the battery cells 110 may be provided in the form of a cell unit 100 covered by a cell cover 200. By providing the battery cells 110 in the form of a cell unit 100, a module case for protecting the battery cells 110 from the external environment is omitted, and the battery cells 110 may be directly mounted and stored inside the pack case 300 without a module case. In the case of pouch-type battery cells, the cell case is made of a soft material and tends to be vulnerable to external impacts and have low hardness. Therefore, it may not be easy to store the battery cells by themselves inside the pack case 300 without storing them in a module case. However, in this embodiment, the cell cover 200 complements the rigidity of the battery cells 110, allowing the battery cells 110 to be directly stored inside the pack case 300 and maintain a stacked state. In addition, the cell cover 200 makes it possible to omit conventional fastening members such as a module case, stacking frame, and bolts, thereby simplifying the manufacturing process and internal structure, reducing the weight and volume of the battery pack, and improving the energy density.

[0047] In this way, the rigidity of the battery cell 110 is complemented by the cell cover 200, which makes it easier to handle the battery cell 110 during the battery pack assembly process. More specifically, by gripping the cell cover 200 coupled to the battery cell 110 during the process of housing the battery cell 110 in the pack case 300, damage to the battery cell 110 can be prevented and the assembly process can be performed more easily. In addition, it is easy to control the expansion of the battery cell 110 and design a gas venting path.

[0048] The cell cover 200 may be for covering at least a portion of the outer surface of the battery cell 110. The cell cover 200 covers a portion of the battery cell 110 and leaves the other portion exposed, thereby improving cooling efficiency and guiding gas generated in the battery cell 110 in a predetermined direction.

[0049] The cell cover 200 complements the rigidity of the battery cells 110, thereby enabling the battery cells 110 to maintain an upright state. The cell cover 200 covers at least a portion of the battery cells 110, thereby supporting the battery cells 110 and enabling the stacked state of the battery cells 110 arranged upright in one direction to be stably maintained. More specifically, the second surface 220 and the third surface 230 of the cell cover 200 support one side of the battery cells 110, thereby enabling the battery cells 110 to maintain an upright state. In addition, the lower corners of the cell cover 200 can be attached to the bottom surface 312 of the pack case 300, thereby enabling the cell cover 200 to stand on its own and maintaining the upright state of the battery cells 110 inside the cell cover 200.

[0050] The cell cover 200 can cover two faces and a periphery between the two faces of the battery cell 110. Alternatively, it can be described as covering two faces of the hexahedral battery cell 110 that face each other and one face that shares a corner with the two faces.

[0051] The cell cover 200 may include a second surface 220 and a third surface 230 that are parallel to and spaced apart from each other, and a first surface 210 that extends between the second surface 220 and the third surface 230. One peripheral edge of the first surface 210 is connected to one peripheral edge of the second surface 220, and the other peripheral edge of the first surface 210 is connected to one peripheral edge of the third surface 230. Alternatively, the second surface 220 may extend in a first direction from one peripheral edge of the first surface 210, and the third surface 230 may extend in the first direction from the other peripheral edge of the first surface 210. In this case, the first direction is substantially perpendicular to the first surface 210 and is represented as the -Z-axis direction in the drawing. In this manner, the cross section of the cell cover 200 may be n-shaped, and the cross section may refer to a cross section of the cell cover 200 in the longitudinal direction (X-axis direction).

[0052] The cell cover 200 may cover one side of the battery cell 110. The second side 220 and the third side 230 of the cell cover 200 may cover both side surfaces of the battery cell 110. The second side 220 and the third side 230 of the cell cover 200 may be positioned parallel to one side of the battery cell 110. More specifically, as shown in FIG. 4 , the second side 220 may cover one side of the right side (-Y axis) of the battery cell 110 from the right side. The third side 230 may cover one side of the left side (+Y axis) of the battery cell 110 from the left side.

[0053] The second surface 220 and the third surface 230 of the cell cover 200 separate the battery cells 110 from the adjacent battery cells 110, thereby preventing gas generated in one battery cell 110 from migrating to the adjacent battery cells 110. In addition, the cell cover 200 is placed in contact with or close to one surface of the battery cell 110, so that heat generated in the battery cell 110 is transferred to the cell cover 200, thereby promoting heat dissipation of the battery cell 110. Furthermore, when the lower corner of the cell cover 200 is placed in contact with the pack case 300 (see FIG. 7 ) that houses the cell unit 100, a heat transfer path can be formed through the battery cell 110, the cell cover 200, and the pack case 300, thereby improving the overall cooling efficiency of the battery pack.

[0054] The cell cover 200 may cover one peripheral edge of the battery cell 110. A first surface 210 of the cell cover 200 may cover one peripheral edge of the battery cell 110. The cell cover 200 may cover the upper peripheral edge of a battery cell 110 that is vertically arranged so that one peripheral edge corresponds to the bottom surface 312 (see FIG. 7 ) of the pack case 300. The first surface 210 of the cell cover 200 may correspond to the upper peripheral edge of the battery cell 110 in an upright state.

[0055] The cell cover 200 may not cover the lower peripheral edge of the vertically arranged battery cell 110 corresponding to the bottom surface 312 of the pack case 300, and the lower peripheral edge of the battery cell 110 may be exposed toward the bottom surface 312. As a result, the battery cell 110 may be in contact with or located close to the bottom surface 312 of the pack case 300, so that heat generated in the battery cell 110 can be rapidly released to the bottom surface 312 of the pack case 300. At this time, if a cooling member is located on the bottom surface 312 of the pack case 300, this heat dissipation effect can be further improved.

[0056] The cell cover 200 may include a fourth surface 240 extending from between the first surface 210, the second surface 220, and the third surface 230. The fourth surface 240 may be described as extending in a first direction from the periphery of the first surface 210 in the length direction (X-axis direction). There may be two fourth surfaces 240, and the two fourth surfaces 240 may be formed at both ends of the cell cover 200 in the length direction (X-axis direction). The fourth surface 240 may be perpendicular to the second surface 220 and the third surface 230. Depending on the shape of the first surface 210, the fourth surface 240 may form an acute angle with the first surface 210.

[0057] Meanwhile, the end of the cell cover 200 in the length direction (X-axis direction) may be open, and the electrode leads 111, 112 of the battery cell 110 may be disposed at the end of the cell cover 200 in the length direction (X-axis direction). Here, the fourth surface 240 may be formed to partially cover the open end. By forming the fourth surface 240 on the cell cover 200, gas generated inside the battery cell 110 can be prevented from migrating along the length direction (X-axis direction) of the cell cover 200. The fourth surface 240 can prevent gas in the battery cell 110 from migrating toward the electrode leads 111, 112. The fourth surface 240 may also be referred to as a "blocking portion."

[0058] In the past, when a fire occurred in a battery cell 110, gas and sparks could move toward the electrode leads 111 and 112, causing additional damage to the electrode leads 111 and 112 of the adjacent battery cells 110 and the bus bars of the battery pack, thereby accelerating thermal runaway. However, in the cell unit 100 of this embodiment, the fourth surface 240 partially covers one surface of the cell cover 200 where the electrode leads 111 and 112 are located, thereby minimizing the movement of gas and sparks toward the electrode leads 111 and 112.

[0059] Referring to Fig. 5, the cell cover 200 of this embodiment may have a sloped top. The cell cover 200 may have a shape in which the width increases toward the end in the length direction (X-axis direction). The cell cover 200 may also have a height increase toward the end in the length direction (X-axis direction). The cell cover 200 may have an overall "M" shape from the front (XZ plane) as a reference.

[0060] The cell cover 200 may include a central portion 202 and a peripheral portion 204. The cell cover 200 may have a shape that slopes upward from the central portion 202 toward the peripheral portion 204. The central portion 202 may be a portion that includes the center (CT) of the cell cover 200 in the length direction (X-axis direction), and the peripheral portion 204 may be a portion that includes the periphery of the cell cover 200 in the length direction (X-axis direction).

[0061] Meanwhile, as will be described later, the central portion 202 of the cell cover 200 may include a first central portion 212 of the first surface 210, a second central portion 222 of the second surface 220, and, although not shown, a third central portion of the third surface 230. The peripheral portion 204 of the cell cover 200 may include a first peripheral portion 214 of the first surface 210, a second peripheral portion 224 of the second surface 220, and, although not shown, a third peripheral portion of the third surface 230.

[0062] The second surface 220 and the third surface 230 may be provided in a shape in which the width increases toward the end in the length direction (X-axis direction). Here, the length direction of the second surface 220 and the third surface 230 may correspond to the X-axis direction, and the width direction may correspond to the Z-axis direction.

[0063] More specifically, the second surface 220 can include a second central portion 222 and a second peripheral portion 224. The second central portion 222 can be defined as a portion including the center (CT) of the second surface 220 in the length direction (X-axis direction), and the second peripheral portion 224 can be defined as a portion including the periphery of the second surface 220 in the length direction (X-axis direction).

[0064] In the second surface 220, the width length (LA) of the second central portion 222 may be smaller than the width length (LB) of the second peripheral portion 224. The width length (LA) of the second central portion 222 may be the minimum width length of the second surface 220, and the width length (LB) of the second peripheral portion 224 may be the maximum width length of the second surface 220. In the second surface 220, the width length value may be relatively smaller the closer to the second central portion 222, and the width length value may be relatively larger the closer to the second peripheral portion 224.

[0065] In response to this change in the length value of the width, the upper periphery of the second surface 220 may be formed in an inclined shape. The second surface 220 may have an overall "M" shape. More specifically, the upper periphery of the second surface 220 may have a shape that is inclined upward toward an end in the length direction (X-axis direction) of the second surface 220. The upper periphery of the second surface 220 may have a shape that is inclined upward from the second center portion 222 toward the second periphery portion 224. Here, the upper periphery may be the periphery located on the +Z-axis of the second surface 220.

[0066] The above description of the second surface 220 can also be applied to the third surface 230.

[0067] Meanwhile, since the upper peripheral edges of the second surface 220 and the third surface 230 have an inclined shape, the first surface 210 connected to the second surface 220 and the third surface 230 may also have an inclined shape. More specifically, the first surface 210 may include a first central portion 212 and a first peripheral portion 214. The first central portion 212 may be a portion including the center (CT) of the first surface 210 in the length direction (X-axis direction), and the first peripheral portion 214 may be a portion including the peripheral edge of the first surface 210 in the length direction (X-axis direction).

[0068] The first central portion 212 may correspond to the second central portion 222. The position of the first central portion 212 relative to the ground, i.e., the height value, may correspond to the width length value of the second central portion 222. The first peripheral portion 214 may correspond to the second peripheral portion 224. The height value of the first peripheral portion 214 relative to the ground may correspond to the width length value of the second peripheral portion 224.

[0069] The first surface 210 may be formed to be inclined at an angle with respect to the ground. In this case, the ground may also be described as the bottom surface 312 of the pack case 300 or the bottom surface 412 of the module case 400. In the first surface 210, the first central portion 212 may be located at a position relatively lower than the first peripheral portion 214. In the first surface 210, the first peripheral portion 214 may be located at a position relatively higher than the first central portion 212. The first surface 210 may have a shape that slopes upward toward an end portion in the length direction (X-axis direction). The first surface 210 may have a shape that slopes upward from the center toward the peripheral portion. A cross section of the first surface 210 in the width direction (Y-axis direction) may have a shape that slopes upward from the center toward the peripheral portion. A cross section (XZ plane) of the first surface 210 in the width direction (Y-axis direction) may be "V" shaped.

[0070] 6, the cell cover 200 of this embodiment may have a sloped top, which limits the direction of gas venting when a thermal event occurs, thereby preventing a chain reaction of thermal runaway. Here, the arrows in FIG. 6 indicate the direction of gas venting.

[0071] Because the cell cover 200 has an inclined shape, the internal volume of the cell cover 200 can be increased compared to a conventional cell cover structure having a flat top, and the flow of venting gas or flame can be guided along the cell cover 200, which is inclined upward, in the event of thermal runaway of the battery cell 110.

[0072] More specifically, the center 202 of the cell cover 200 may have a relatively small volume, and the peripheral portion 204 may have a relatively large volume. When venting gas is generated inside the cell cover 200 due to thermal runaway, the venting gas may move to the peripheral portion 204, which has a relatively large volume, to relieve the increased internal pressure of the cell cover 200. Meanwhile, the peripheral portion 204 may have a fourth surface 240, which prevents the venting gas from moving further along the length direction (X-axis direction) of the cell cover 200. When the gas collides with the fourth surface 240, its movement direction is changed, and it may move toward the lower side (-Z-axis direction) of the cell cover 200. As will be described later, a venting hole may be formed on the lower surface of the pack case 300 to which the cell unit 100 is attached. The venting hole may be positioned to correspond to the gas discharge direction induced by the cell cover 200, thereby preventing the venting gas or flame from being randomly discharged from the cell cover.

[0073] The cell cover 200 may be made of a material with a high melting point so as not to melt even in the event of thermal runaway inside the battery pack. In addition, the cell cover 200 may be made of a material with a mechanical strength above a predetermined range so as to stably support the battery cell 110, thereby protecting the battery cell 110 from external impacts, etc. Examples of materials used for the cell cover 200 include steel, stainless steel (SUS), etc.

[0074] The cell cover 200 may be coupled to the upper side of the battery cell 110 to cover the battery cell 110. Here, an adhesive thermally conductive resin or the like may be provided between the cell cover 200 and the battery cell 110, but this is not necessarily the case, and no other material may be interposed between the cell cover 200 and the battery cell 110. This is to maximize the number of battery cells 110 accommodated inside the pack case 300 by minimizing the volume of the cell cover 200 and the battery cell 110, thereby maximizing the energy density of the battery pack.

[0075] In this embodiment, the cell cover 200 is described as covering one battery cell 110 individually, but this is not necessarily the case, and the cell cover 200 can also be designed to cover two or more battery cells 110 depending on the designer's intention.

[0076] In this embodiment, the cell covers 200 are described as being provided for all the battery cells 110, but this is not necessarily the case, and the cell covers 200 may be provided for only some of the multiple battery cells 110.

[0077] Although the cell cover 200 of this embodiment has been described as being n-shaped, it may be configured in other shapes as long as it achieves the purpose of preventing gas and other contaminants from transferring to the electrode leads 111, 112 and other electrical components. For example, the cell cover may be formed in a square shape, a U shape, an O shape, an L shape, etc.

[0078] Meanwhile, although not specifically shown, the cell cover 200 of this embodiment may be provided with a clamping member. The clamping member fixes different ends of the cell cover 200 to prevent them from expanding or deforming. For example, the clamping member may be provided at the lower end of the cell cover 200 where the lower periphery of the battery cell 110 is located, and prevents the second surface 220 and the third surface 230 from expanding, thereby maintaining the battery cell 110 in a housed state. As a specific example, the clamping member may be tape. As another specific example, the clamping member may be made of an elastic metal material.

[0079] Although not specifically shown, a bus bar frame may be coupled to an end of the cell cover 200 in the length direction (X-axis direction). The end of the cell cover 200 in the length direction (X-axis direction) may be open, and the open end may be covered by the bus bar frame. The bus bar frame may be configured to electrically connect the battery cell 110 covered by the cell cover 200 to an external conductive member or an adjacent battery cell 110. The bus bar frame may be configured to support the electrode leads 111, 112 of at least one battery cell 110 and electrically connect the electrode leads 111, 112 of the battery cell 110 to the electrode leads 111, 112 of the adjacent battery cell 110. The bus bar frame may include a bus bar made of an electrically conductive material such as copper and a bus bar housing made of a plastic material such as polycarbonate (PC).

[0080] A battery pack including the above-described cell unit will now be described.

[0081] Figure 7 is a view showing a pack case of a battery pack according to an embodiment of the present invention. Figure 8 is an enlarged view of a portion AA in Figure 7. Figures 9 and 10 are views schematically showing directional venting of a battery pack according to an embodiment of the present invention. Here, the arrows in Figure 10 may exemplify the gas venting direction.

[0082] The cell unit 100 of this embodiment may be housed inside the pack case 300 and provided in the form of a battery pack. The cell unit 100 may be housed inside the pack case 300, thereby protecting it from the external environment. There may be a plurality of cell units 100, and the plurality of cell units 100 may be housed in the pack case 300 by being stacked in one direction. The cell units 100 may be arranged consecutively such that one surface of the cell unit 100 is parallel to one surface of an adjacent cell unit 100. The cell units 100 may be arranged consecutively such that the side surface of the cell unit 100 is parallel to the side surface of an adjacent cell unit 100. One surface of the cell unit 100 may be perpendicular to the bottom surface 312 of the pack case 300. The cell units 100 may be arranged such that the bottom surface thereof corresponds to the bottom surface 312 of the pack case 300.

[0083] Meanwhile, the plurality of battery cells 110 may be arranged along the thickness direction (Y-axis direction) or the left-right direction of the battery cell 110. The plurality of battery cells 110 may also be arranged along the length direction (X-axis direction) or the front-rear direction of the battery cell 110. In this manner, the plurality of battery cells 110 are stacked along the thickness direction (Y-axis direction) to form a cell assembly, and such cell assemblies may be arranged in two columns and two rows along the thickness direction (Y-axis direction) and length direction (X-axis direction) and then housed in the pack case 300. However, this is merely an example, and the cell assemblies may also be arranged consecutively along the thickness direction (Y-axis direction) or length direction (X-axis direction).

[0084] As shown in FIG. 7 , the pack case 300 may include a lower case 310 and an upper case 320. The lower case 310 may include a bottom surface 312 and a lower side surface 314 extending vertically from one corner of the bottom surface 312, thereby forming an internal space capable of accommodating a plurality of battery cells 110. The upper case 320 may include a top surface 322 and an upper side surface 324 extending vertically from one corner of the top surface 322. The lower side surface 314 may overlap at least a portion of the upper side surface 324. Here, an upper coupling portion 326 extending vertically from one surface of the upper side surface 324 may be formed on the upper side surface 324, and a lower coupling portion 316 extending vertically from one surface of the lower side surface 314 may be formed on the lower side surface 314. The lower case 310 and the upper case 320 may be coupled together by coupling the upper coupling portion 326 and the lower coupling portion 316.

[0085] However, the structure of the pack case 300 described above is merely exemplary, and the pack case 300 of this embodiment may be provided with a different structure. For example, the pack case 300 may include a bottom, side surfaces extending vertically from one corner of the bottom, and a top surface that is parallel to the bottom and connected to each peripheral edge of the lower side surface. Here, the bottom, lower side surfaces, and top surface may be integrally formed, which may be referred to as a monoframe structure. Alternatively, the bottom, lower side surfaces, and top surface may be connected by a welding process. As such, the pack case 300 of this embodiment is not limited to the illustrated structure and may be implemented with various modifications and variations as long as it can house and protect the cell units 100 therein.

[0086] Meanwhile, an adhesive may be provided between the battery cell 110 and the pack case 300 so that the battery cell 110 accommodated in the cell cover 200 can be stably positioned in the pack case 300. More specifically, an adhesive may be provided between one periphery of the battery cell 110 and the bottom surface 312 of the pack case 300. In this case, the periphery of the battery cell 110 to which the adhesive is provided may be the unsealed portion 132. Examples of the adhesive include a thermally conductive resin, a thermally insulating material (TIM), etc., and any known material having thermal conductivity or adhesive properties may be used. In addition, such an adhesive may be provided between the cell cover 200 and the pack case 300 or between the battery cell 110 and the cell cover 200 to strengthen the structure of the battery pack.

[0087] 8, in this embodiment, a vent hole 330 may be formed in a bottom surface 312 of the pack case 300 to discharge gas generated in the battery cells 110 to the outside of the pack case 300. The vent hole 330 may be used to communicate the inside and outside of the pack case 300.

[0088] The cell cover 200 covering the outer surface of the battery cell 110 may have an open bottom, and the cell cover 200 may not cover the lower periphery of the battery cell 110. This allows the battery cell 110 to be exposed to the outside of the cell cover 200 and to face the bottom surface 312 of the pack case 300.

[0089] 6 and 10, the movement of gas generated in the battery cell 110 is restricted by the cell cover 200 and may be concentrated at the lower periphery of the battery cell 110. The venting gas concentrated at the bottom inside the cell cover 200 may be discharged to the outside through venting holes 330 formed in the bottom surface 312 of the pack case 300.

[0090] The venting holes 330 may correspond to each of the plurality of cell units 100. There may be a plurality of venting holes 330, with at least one venting hole 330 corresponding to each cell unit 100. Alternatively, one venting hole 330 may correspond to a plurality of cell units 100.

[0091] The plurality of venting holes 330 may be positioned in a row along the stacking direction of the cell units 100. As described above, when the cell units 100 are arranged continuously along the thickness direction (Y-axis direction), the plurality of venting holes 330 may be positioned continuously along the thickness direction (Y-axis direction) of the cell units 100.

[0092] The venting holes 330 may correspond to the ends of the cell units 100 in the length direction (X-axis direction). The venting holes 330 may be arranged in two rows or two columns to correspond to the ends of the cell units 100 in the length direction (X-axis direction). The venting holes 330 may be formed continuously along two parallel straight lines on the bottom surface 312 of the internal space in which a plurality of cell units 100 are accommodated.

[0093] 9 and 10 , the effects of the cell cover 200 of the present invention can be explained. More specifically, gas generated in the battery cell 110 due to a thermal event is restricted in its movement by the cell cover 200, concentrated on the bottom surface 312 of the pack case 300, and can be discharged through the vent holes 330 formed in the bottom surface 312. More specifically, the movement of gas generated in the battery cell 110 in the thickness direction (Y-axis direction) can be restricted by the second surface 220 and the third surface 230 of the cell cover 200. In addition, the movement of gas in the length direction (X-axis direction) can be restricted by the fourth surface 240 of the cell cover 200. In addition, because the movement of gas in the upper direction (+Z-axis) is also restricted by the first surface 210 of the cell cover 200, it can be concentrated on the lower direction (−Z-axis) and can be discharged through the vent holes 330 provided in the pack case 300. Furthermore, since the cell cover 200 has a sloped upper portion, the internal gas can be concentrated at the end in the length direction (X-axis direction) of the cell cover 200. The venting holes 330 are positioned to correspond to the end in the length direction (X-axis direction) of the cell cover 200, so that the internal gas can be quickly discharged through the venting holes 330.

[0094] Meanwhile, the above description has focused on a module-less structure in which a cell assembly including a plurality of battery cells 110 is not sealed by a module case. Here, the module-less structure refers to a cell-to-pack structure in which a cell structure is directly coupled to a pack structure without a module case.

[0095] However, unlike the above, the cell unit 100 of this embodiment can also be mounted in a battery pack while housed inside a separate case.

[0096] 11 is a view showing a case provided for a plurality of cell units according to an embodiment of the present invention, and FIG. 12 is an enlarged view of the bottom surface of the case according to FIG.

[0097] 11 and 12, the cell unit 100 of this embodiment can be housed in a module case 400 and mounted in a modularized state in a battery pack.

[0098] The modular case 400 may be provided in various forms. As an example, the modular case 400 may have a mono-frame structure. Here, the mono-frame may be a metal plate having an integrated top surface 422, bottom surface 412, and both side surfaces 414. The mono-frame may be manufactured by extrusion molding. As another example, the modular case 400 may have a structure in which a U-shaped frame and an upper plate are combined together. In the case of a U-shaped frame and an upper plate combined together structure, the modular case 400 may be formed by combining the upper surface 422 with the upper part of a U-shaped frame, which is a metal plate having an integrated or combined bottom surface and both side surfaces, and each component may be manufactured by press molding. Furthermore, the modular case 400 may have an L-shaped frame structure in addition to the mono-frame or U-shaped frame structure, and may also have various structures not described in the above examples.

[0099] The battery cells 110 located inside the module case 400 may be in the form of cell units 100 protected by cell covers 200. In this case, the cell covers 200 included in the cell units 100 may have an open bottom and not cover the lower edges of the battery cells 110. As a result, the battery cells 110 may be exposed to the outside of the cell covers 200 and face a bottom surface 412 of the module case 400. A vent hole 430 for discharging gas generated in the battery cells 110 to the outside of the module case 400 may be formed in the bottom surface 412.

[0100] 10, the internal gas of the cell unit 100 can be concentrated at the end in the length direction (X-axis direction) and move downward due to the inclined shape of the cell unit 100. The venting hole 430 can be positioned to correspond to the end in the length direction (X-axis direction) of the cell unit 100, so that the venting hole 430 can easily accommodate the gas that moves downward and quickly discharge the gas.

[0101] The venting holes 430 of the module case 400 have a purpose and use similar to those of the venting holes 330 of the pack case 300, and for more details regarding the venting holes 430 of the module case 400, please refer to the explanation regarding "venting holes 330" in Figures 7 to 10 above.

[0102] 11, the electrode leads 111, 112 of the battery cells 110 are exposed to the outside of the cell cover 200, and the battery cells 110 in this state are shown housed in the module case 400. However, this is merely a simplification of the drawing, and when actual battery cells 110 are housed in the module case 400, the battery cells 110 housed in each cell unit 100 may be electrically connected to adjacent battery cells 110 and / or bus bars via a bus bar frame or the like.

[0103] In addition, although the above description has been made separately regarding a battery pack and a battery module, the battery pack and the battery module all include a cell unit 100 including a battery cell 110, and may also be referred to as a minimum unit for sale or use. Therefore, the terms battery pack and battery module in this specification may be used interchangeably.

[0104] Furthermore, the above-mentioned pack case 300 and module case 400 are used to protect the cell unit 100 from the external environment and have the same purpose, so they can be collectively referred to as cases.

[0105] Meanwhile, the battery module and the battery pack including the same can be applied to various devices. Such devices can include not only transportation means such as electric bicycles, electric vehicles, and hybrid vehicles, but also energy storage devices such as energy storage systems (ESS). However, the present invention is not limited thereto and can be applied to various devices that can use the battery module and the battery pack including the same, which also fall within the scope of the present invention.

[0106] 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 claims below also fall within the scope of the present invention.

[0107] 100 cell units 110 battery cells 200 cell covers 300 pack case 312 bottom 330 Venting Hall 400 Module Case 412 bottom 430 Venting Hall

Claims

1. A plurality of cell units arranged side by side in one direction; a pack case that houses the plurality of cell units; Including, The cell unit comprises: at least one battery cell; a cell cover that covers a portion of the battery cell; Including, The cell cover has an upper portion having a sloped shape, The cell cover is a shape that is inclined upward from a center of the cell cover toward one end in a length direction of the cell cover where one electrode lead of the battery cell is located; a shape that is inclined upward from a center of the cell cover toward another end portion of the cell cover in a length direction where the other electrode lead of the battery cell is located; A battery pack having:

2. The battery pack according to claim 1 , wherein the cell cover has a width at a periphery that is greater than a width at a center portion.

3. the battery cell is vertically disposed so that one peripheral edge thereof corresponds to the bottom surface of the pack case; The battery pack according to claim 1 , wherein the cell cover covers upper peripheral edges of the vertically arranged battery cells and leaves lower peripheral edges of the battery cells open.

4. the cell cover has a second surface and a third surface disposed parallel to the one surface of the battery cell; a first surface extending between the second surface and the third surface; Including, The battery pack according to claim 1 , wherein a cross section of the cell cover has an n-shape.

5. the second surface includes a second central portion and a second peripheral portion; The battery pack according to claim 4 , wherein a length value of the width of the second central portion is smaller than a length value of the width of the second peripheral portion.

6. The battery pack according to claim 4 , wherein an upper peripheral edge of the second surface has a shape that slopes upward toward an end of the second surface in the length direction.

7. The battery pack according to claim 4 , wherein a cross section of the first surface in the width direction has a shape that slopes upward toward an end in the length direction.

8. the cell cover includes a fourth surface; The battery pack of claim 4 , wherein the fourth surface extends from between the first surface, the second surface, and the third surface.

9. The battery pack according to claim 8 , wherein the fourth surface partially covers an open longitudinal end of the cell cover.

10. The battery pack according to claim 1 , wherein a vent hole communicating with the outside is formed in a bottom surface of the pack case.

11. The battery pack according to claim 10 , wherein the venting holes are located at positions corresponding to longitudinal ends of the cell units.

12. The battery pack according to claim 10 , wherein the venting hole is a plurality of venting holes, and the plurality of venting holes are positioned in a line.

13. The battery pack according to claim 1 , wherein the plurality of cell units are housed in the pack case while being housed in a separate case.

14. A device comprising the battery pack of claim 1.

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