Battery pack

Abstract

The present invention discloses a battery pack having an improved structure to improve energy density and enhance safety when a thermal event occurs in an individual battery cell or cell assembly. A battery pack according to one aspect of the present invention includes a cell assembly including n (n is a natural number of 1 or more) battery cells, a cell case that houses the cell assembly therein, and a pack housing that houses one or more of the cell cases in an internal space.

Description

[Technical field]

[0001] This application claims priority to Korean Patent Application No. 10-2022-0097741, filed on August 5, 2022, the entire contents of which are incorporated herein by reference in their entirety in the specification and drawings.

[0002] The present invention relates to a battery pack, and more particularly to a battery pack having improved energy density of a battery cell and enhanced safety in the event of a thermal event. [Background technology]

[0003] Demand for portable electronic products that use electricity as a power source, such as laptops, video cameras, and mobile phones, is growing rapidly, and mobile robots, electric bicycles, electric carts, and electric cars are being commercialized. As a result, research into high-performance secondary batteries that can be repeatedly charged and discharged is being actively conducted.

[0004] Commercially available secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, and lithium secondary batteries. Among them, lithium secondary batteries have the advantages of almost no memory effect compared to nickel-based secondary batteries, being freely chargeable and dischargeable, and having a very low self-discharge rate. In addition, they have the characteristics of high energy density and high operating voltage. Therefore, they are being researched more intensively than other types of secondary batteries and are being applied more extensively to actual products.

[0005] Recently, secondary batteries have been widely used not only in small devices such as portable electronic devices, but also in medium to large devices such as electric vehicles and energy storage systems (ESS).

[0006] A conventional battery pack is basically configured by housing a plurality of battery modules in a pack case, and each battery module is configured by housing a plurality of secondary batteries, which are electrically connected together, inside a module case.

[0007] Pouch-type batteries have many advantages such as being lightweight and leaving little dead space when multiple units are stacked or arranged, but are relatively vulnerable to external impacts and are somewhat difficult to assemble due to their shape, material, etc. As a result, in the case of the conventional battery packs described above, a method is applied in which a battery module is first constructed by housing multiple pouch-type battery cells in a module case, and then the multiple battery modules are housed in a pack case.

[0008] For this reason, a portion of the space in a conventional battery pack must be used as space for multiple battery modules, which reduces the number of battery cells that can be stored and reduces the energy density. Furthermore, if the same number of battery cells were to be stored, the size of the battery pack itself would be larger.

[0009] A battery module requires a significant amount of space since it is made up of various physical and electrical components such as a module case, a stacking frame, and an electrical connection structure. In addition, additional space is required to ensure the assembly or design tolerance of components, resulting in a significant loss of space in terms of energy density.

[0010] In addition, in the case of a conventional battery pack, a process of modularizing a plurality of battery cells is always required beforehand, which makes the manufacturing or assembly process of the battery pack itself complicated and lengthy. Furthermore, since the battery cells, which are heat generating bodies, are covered with a double case, it is difficult to dissipate heat from the battery cells to the outside, and the cooling or heat dissipation efficiency may also be reduced.

[0011] Meanwhile, although the range of applications of secondary batteries is expanding, due to the behavioral characteristics of secondary batteries, swelling, application of rush current, overheating due to Joule heating, or thermal runaway due to decomposition reaction of electrolyte may occur.

[0012] In addition, if an event such as a short circuit between secondary batteries or excessive temperature rise occurs, a large amount of vent gas may be generated, and in serious cases, not only flames but also high-temperature particles including electrode active material and aluminum particles may be released together, making it even more important to ensure the safety of the battery pack.

[0013] Battery packs are more vulnerable to thermal events because a large number of secondary cells (battery cells) are densely packed in a space. In particular, if thermal runaway occurs in a battery cell, high-temperature gas, flames, and heat are generated, and if these are not quickly controlled, a chain reaction fire or explosion may spread to the adjacent battery cells (cell assemblies) as well as the battery cell (cell assembly) due to thermal propagation.

[0014] In the case of medium- to large-sized battery packs applied to vehicles such as passenger-carrying electric vehicles, a large number of battery cells are mounted in a more intensive manner in order to increase output and capacity, which may cause a large-scale fire and even damage to human life. Therefore, there is a great need to more strongly suppress and control thermal events that may occur in battery cells from the early stages. Summary of the Invention [Problem to be solved by the invention]

[0015] The present invention has been made to solve the above problems, and an object of the present invention is to provide a battery pack that can improve process efficiency by directly housing a battery cell in a battery pack and effectively suppress the diffusion of generated vent gas, etc.

[0016] The technical problems to be solved by the present invention are not limited to the problems mentioned above, and other problems will be clearly understood by those skilled in the art from the following description of the invention. [Means for solving the problem]

[0017] In order to achieve the above object, a battery pack according to one aspect of the present invention includes a cell assembly consisting of one or more battery cells, a cell case that houses the cell assembly therein, and a pack housing that houses the one or more cell cases in an internal space.

[0018] In this case, the cell case may include a metal cover that houses the cell assembly therein, an opening formed in the cover to expose an electrode portion of the cell assembly to the outside, and an insulating block provided in the opening to insulate the electrode portion from the cover.

[0019] Preferably, the insulating block may include a body portion and a slot portion formed in the body portion to provide a space through which the electrode portion passes.

[0020] The pack housing may further include a vent frame having an access hole formed at a position corresponding to the insulating block, in which case the insulating block may be configured to move toward the access hole when a thermal event occurs in the cell assembly.

[0021] The slot portion may be configured such that the space in the outward direction, which is the direction toward the entrance hole, is smaller than the space in the opposite direction, which is the inward direction.

[0022] The vent frame may further include a blocking member provided in the inlet hole and configured to be partially or completely removed from the inlet hole to open the inlet hole when the insulating block moves.

[0023] More preferably, the horizontal length of the main body portion may be configured to be longer than a first separation distance, which is the distance between the vent frame and the cell casing, so that when one end of the main body portion enters the entry hole due to the thermal event, the other end of the main body portion does not leave the opening.

[0024] In addition, the insulating block may further include a locking structure formed on the other end of the main body portion to prevent the main body portion from escaping outside the opening, and it is preferable that the main body portion of the insulating block is configured so that its length can be extended toward the entrance hole side.

[0025] The vent frame may also include vent channels therein that extend or redirect the path of the vent gas.

[0026] In addition, the cover of the cell case may further include a first coupling portion provided on one side and having a first coupling structure, and a second coupling portion provided on the other side, having a coupling structure corresponding to the first coupling structure, and coupling to the first coupling portion provided on the cover of another adjacent cell case.

[0027] In order to achieve the above object, a vehicle according to another aspect of the present invention includes a battery pack according to an aspect of the present invention. Effect of the Invention

[0028] According to one aspect of the present invention, a plurality of battery cells can be directly housed in a pack case (pack housing) without a separate stacking frame or module case, thereby improving process efficiency and more effectively improving energy density.

[0029] In particular, according to one aspect of the present invention, a hexahedral case having a minimized structure is applied to each of one or more battery cell units, making it easier to implement a process of stacking or arranging a plurality of battery cells in an upright state in a pack case.

[0030] Furthermore, according to one aspect of the present invention, since the cell case contains a material that is highly resistant to thermal events, such as SUS (stainless steel), it is possible to suppress or delay the propagation of a thermal event that occurs in an individual battery cell (cell assembly) to other battery cells (cell assemblies).

[0031] According to one aspect of the present invention, an insulating block that insulates between an electrode portion of a battery cell and a cell case can be used as a medium that forms a closed path through which vent gas is discharged, thereby effectively preventing the vent gas from diffusing to other adjacent battery cells (cell assemblies).

[0032] In particular, through a configuration in which the insulating block is guided to naturally enter the inlet hole of the vent frame (having a vent channel inside) due to the pressure of the vent gas generated inside, the vent gas generated in the corresponding battery cell or cell assembly can be effectively discharged to the outside through the vent frame installed in the pack housing (pack case) without any artificial operation or the addition of a complex structure.

[0033] In addition, according to one aspect of the present invention, during processes such as storing battery cells or cell assemblies in a pack housing, direct contact between workers or process fixtures and devices and the battery cells can be essentially avoided, thereby effectively preventing damage or breakage, such as cracks, of the battery cells. In addition, the process is performed using a cell case having an optimal volume as a unit, thereby improving the efficiency of the processing process.

[0034] The present invention has many other advantages, which will be described in the respective embodiments, but explanations of advantages that can be easily inferred by those skilled in the art will be omitted.

[0035] The following drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the detailed description of the invention, serve to further understand the technical ideas of the present invention. Therefore, the present invention should not be interpreted as being limited to only the matters described in the drawings. [Brief description of the drawings]

[0036] [Figure 1] 1 is a perspective view illustrating an overall appearance of a battery pack according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a diagram showing a cell case with a cell assembly housed therein. [Diagram 3] FIG. 3 is a perspective view showing the overall appearance of the cell case shown in FIG. 2. [Figure 4] FIG. 2 is an exploded perspective view of a cell casing according to one embodiment of the present invention. [Diagram 5] 1 is a diagram illustrating an insulating block according to an embodiment of the present invention coupled to an electrode portion of a cell assembly. [Figure 6] FIG. 2 is a diagram showing the structure of a vent frame according to one embodiment of the present invention. [Figure 7] FIG. 13 is a diagram showing the relationship between a vent frame and a cell case. [Figure 8] FIG. 13 is a diagram showing the relationship between a vent frame and a cell case. [Figure 9] FIG. 8 is an enlarged view of part A in FIG. [Figure 10] 10 is a diagram showing an operational relationship in which the insulating block shown in FIG. 9 moves into the entrance hole of the vent frame. [Figure 11] 13A and 13B are diagrams illustrating an insulating block according to another embodiment of the present invention. [Figure 12] 13A and 13B are diagrams illustrating an insulating block according to another embodiment of the present invention. [Figure 13]FIG. 13 is a diagram showing the outer structure of a cell casing according to another embodiment of the present invention. [Figure 14] FIG. 2 illustrates a pack housing equipped with a heat sink according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0037] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, the terms and words used in the present specification and claims are not to be construed as being limited to their ordinary and dictionary meanings, but are to be construed as having meanings and concepts corresponding to the technical ideas of the present invention, in accordance with the principle that the inventors themselves can appropriately define the concepts of terms in order to best describe the invention.

[0038] Therefore, it should be understood that the embodiment described in this specification and the configurations shown in the drawings are merely the most preferred embodiment of the present invention and do not represent the entire technical idea of ​​the present invention, and therefore there may be various equivalents and modifications that can be substituted therefor at the time of this application.

[0039] FIG. 1 is a perspective view showing an overall appearance of a battery pack 1000 according to an embodiment of the present invention, and FIG. 2 is a view showing a cell case 200 in which a cell assembly 100 is housed.

[0040] The battery pack 1000 according to an embodiment of the present invention is configured in such a way that a plurality of battery cells 110 are directly installed in a pack housing 300 without the use of an intermediate component such as a battery module in which the battery cells are housed.

[0041] As shown, a battery pack 1000 according to one embodiment of the present invention may include a pack housing 300 that functions as a case, a cell assembly 100 consisting of n battery cells 110, and a cell case 200 that houses the cell assembly 100 therein.

[0042] Since one or more battery cells 110 may be grouped together to be housed inside the cell case 200, n is a natural number equal to or greater than 1. When a plurality of battery cells 110 are grouped together, electrodes of the individual battery cells 110 that correspond to the same polarity are connected to each other by a known method and means to form a common electrode portion.

[0043] The pack housing 300 according to an embodiment of the present invention provides an internal space in which one or more cell cases 200 are housed. Specifically, the pack housing 300 may include an upper frame 310, a lower frame 320, and side frames 330-360.

[0044] The upper frame 310, the lower frame 320 or the side frames 330 to 360 may be in the form of a plate, but may also be configured in the form of a polyhedron (for example, a rectangular parallelepiped) having a certain thickness or more.

[0045] The upper frame 310 is located on the upper part of the pack housing 300, the lower frame 320 is disposed below the upper frame 310 at a predetermined distance therefrom, and the side frames 330 to 360 may be disposed between the upper frame 310 and the lower frame 320 with their upper ends and lower ends connected to each other.

[0046] At least some of the upper frame 310, the lower frame 320, and the side frames 330 to 360 may be configured in an integrated form with each other. For example, the right frame 360 ​​and the left frame 350 among the side frames 330 to 360 may be configured in an integrated form with the lower frame 320. In this case, the left frame 350, the right frame 360, and the lower frame 320 that are integrated with each other may be referred to as a U-frame based on their shape characteristics.

[0047] In this case, the front frame 330 and the rear frame 340 are end frames, which are respectively connected to the front and rear open portions of the U-frame, and the top frame 310 may be connected to the upper open portion of the U-frame. Adjacent frames may be connected to each other by flange and bolt fastening, laser welding, ultrasonic welding, etc.

[0048] One or more of the upper frame 310, the lower frame 320, and the side frames 330 to 360 may include a clad metal on the inner surface, or a flame-retardant material such as GFRP (Glass Fiber Reinforced Polymer) may be attached to the inner surface.

[0049] One or more of the frames (upper frame 310, lower frame 320, side frames 330-360) that make up pack housing 300 may include a metal such as high-strength SUS (stainless steel), or a plastic such as ABS (acrylonitrile-butadiene-styrene) resin that has high heat resistance, temperature resistance, and impact resistance, or other types of plastic, in order to effectively provide physical protection for the internal components, and depending on the embodiment, different parts may include different types of materials.

[0050] Each frame can function as a vent unit or a vent frame that forms a vent channel VC (see FIG. 7, etc.) so that vent gas, flame, etc. can flow inside. In this case, it is preferable that the exhaust path of the vent gas is extended so that the temperature of the vent gas is lowered during the exhaust process of the vent gas.

[0051] In addition, when a flame is discharged together with the vent gas, it is more preferable to provide a guide or vent rib 375 (see Figure 7, etc.) having a bent shape in the vent channel, etc., so as to weaken the flame by reducing the strong straightness, which is a behavior characteristic of the flame.

[0052] In particular, as shown in Fig. 1, when the cell casing 200, i.e., the cell assembly 100, is generally composed of a 2 x 1 matrix group, it is preferable that a vent frame 370 is provided between the first group and the second group. The vent frame 370 will be described in detail later.

[0053] In addition, although not directly shown, one or more vent holes that function as a type of outlet through which vent gas generated from the cell assembly 100, etc. is discharged to the outside through the vent frame 370 may be formed in one or more of the frames (upper frame 310, lower frame 320, side frames 330-360).

[0054] According to an embodiment, a heat shielding member P having a vertically standing form (based on the Z-axis) may be interposed between the cell cases 200. The heat shielding member P may be made of a ceramic material such as mica or a material such as silicone, and serves to block or reduce the propagation of heat, gas, flame, etc. that may occur between the cell assemblies 100 or the cell cases 200, or to delay the propagation time.

[0055] The drawings show an example in which cell cases 200 (with cell assemblies 100 inside) consisting of a 2×1 matrix group based on the vertical (X-axis) and horizontal (Y-axis) are housed in a pack housing 300, but cell assemblies 100 having various arrangements such as 1×1, 2×4, 3×2 matrix groups, etc. may be provided in the pack housing 300 depending on the spatial characteristics, electrical capacity, power size, etc. of the applied device.

[0056] Also, referring to FIG. 1, an embodiment in which a heat-shielding member P is interposed between cell cases 200 at the rear (X-axis reference) of the pack housing 300, and an embodiment in which a heat-shielding member P is not interposed at the front in order to increase the energy density, i.e., the number of cell assemblies 100 provided per unit area, are shown, however, this is merely a symbolic example of various embodiments and may be configured in various other forms.

[0057] The battery cell 110 refers to a secondary battery including an electrode assembly, an electrolyte, a battery case, etc., and the drawing shows a pouch-type secondary battery as an example, which has high energy density and is easy to stack.

[0058] As shown in FIG. 2, a cell assembly 100 consisting of n battery cells 110 is housed in a cell case 200 of the present invention with its minor axis standing vertically (Z-axis in the drawing).

[0059] The cell case 200 includes a cover 210 that functions as an exterior material of the cell case 200. The cover 210 may have various embodiments, including a dual-sided form with left and right sides, such as a first cover 210-1 and a second cover 210-2 shown in FIG 2, so that assembly and coupling can be performed after the cell assembly 100 is housed therein.

[0060] In order to physically protect the cell assembly 100 housed therein, the cover 210 preferably comprises a material having structural rigidity, and when provided on the bottom surface of the pack housing 300, for example, it is preferable that the cover be configured in a polyhedral shape with a flat bottom in order to improve assembly efficiency.

[0061] In addition, it is preferable that the cover 210 includes a stainless steel material having excellent heat resistance so as to effectively block or suppress the diffusion or propagation of a thermal event occurring in a cell assembly 100 consisting of one or more battery cells 110 to other adjacent cell assemblies 100.

[0062] When the cover 210 of the cell case 200 contains SUS material, its melting point is higher than that of aluminum, which is mainly used for metal cases, so that even if a flame or the like occurs inside, the structural form can be stably maintained, and the spread of thermal events to other adjacent cell cases 200, etc. can be delayed or suppressed.

[0063] In addition, since SUS material has excellent mechanical strength and rigidity, it can more stably support the stacked state of the pouch-type battery cells 110 and effectively prevent external impact from being transmitted to the battery cells 110 contained inside, thereby effectively preventing damage or breakage of the battery cells 110.

[0064] Although not shown, a TIM (Thermal Interface Material) may be interposed between the cell assembly 100 and the cell case 200, and between the cell case 200 and the pack housing 300, in order to improve cooling efficiency.

[0065] Meanwhile, the inner surface of the cover 210 in which the battery cell 110 or the cell assembly 100 is housed may be provided with an insulating member or insulating sheet including a non-conductive material, and depending on the embodiment, the insulating member etc. may be configured to be attached to the inner surface of the cover 210 by having an adhesive layer on one side.

[0066] According to such an embodiment, not only can short circuits caused by cracks in the outer casing of the pouch be prevented, but when the first cover 210-1 and the second cover 210-2 are combined to form one cover 210, the bonding strength between the first cover 210-1 and the second cover 210-2 can also be strengthened.

[0067] As shown in the drawings, the cell case 200 of the present invention includes an opening 220 formed in a cover 210 to expose the electrode unit 120 of the cell assembly 100 to the outside, and an insulating block 230 provided in the opening 220 to insulate the electrode unit 120 of the cell assembly 100 from the cover 210. The detailed function and operation of the insulating block 230 will be described later.

[0068] In addition, although not shown, the electrode unit 120 of the cell assembly 100 exposed to the outside may be electrically connected by a metal bus bar having electrical conductivity. In this case, the bus bar or the like is preferably bent upward or downward one or more times to minimize interference due to the relationship with the insulating block 230 or the physical movement of the insulating block 230, and a slit or notch capable of adaptively accommodating such a bus bar shape may be provided at one or more of the upper and lower parts of the insulating block 230.

[0069] The illustrated axes, terms referring to the axes, and terms indicating directions such as upper, lower, front, rear, vertical, etc., described based on the axes, are intended to provide a relative reference for describing the embodiment of the present invention, and are not intended to specify any direction or position on an absolute basis, and may of course change relatively depending on the position of the target object, the position of the observer, the viewing direction, etc.

[0070] Hereinafter, as described above, the embodiment of the present invention will be described with the Z axis as the up-down or vertical reference, and from the corresponding viewpoint, the embodiment of the present invention will be described with the X axis as the front or rear reference and the Y axis as the left or right reference. According to such reference, the XY plane is the horizontal plane in the embodiment of the present invention, and the X axis direction is the longitudinal direction (long axis reference) of the battery cell 110 and the cell assembly 100.

[0071] FIG. 3 is an oblique view showing the overall appearance of the cell case 200 shown in FIG. 2, FIG. 4 is an exploded oblique view of the cell case 200 according to one embodiment of the present invention, and FIG. 5 is a diagram illustrating an insulating block 230 according to one embodiment of the present invention which is combined with the electrode portion 120 of the cell assembly 100.

[0072] As briefly described above, a cell casing 200 according to one embodiment of the present invention may include a cover 210, an opening 220 formed at one or more of the front and rear of the cover 210, and an insulating block 230 provided in the opening.

[0073] When the cover 210 is an integrated type, the opening 220 may be formed by a punching method. When the cover 210 is divided into a first cover 210-1 and a second cover 210-2 and then combined, spaces may be formed in front and behind the first cover 210-1 and the second cover 210-2, respectively, and the first cover 210-1 and the second cover 210-2 may be combined to form the opening 220 overall.

[0074] The openings 220 formed in the cover 210 are preferably provided at positions corresponding to the electrodes of the cell assembly 100 housed therein. In the illustrated example, the openings 220 are formed in the center portions of the front and rear surfaces (YZ plane) of the cover 210, but if the electrodes of the cell assembly 100 are offset downward or upward (based on the Z axis) according to the embodiment, the positions of the openings 220 may be offset upward or downward from the center accordingly.

[0075] The opening 220 provides a space through which the electrode unit 120 of the cell assembly 100 housed inside the cell case 200 is exposed to the outside. The cover 210, which functions as an exterior material of the cell case 200, is preferably made of a metal material such as SUS to provide structural rigidity and heat resistance. In this case, if the electrode unit 120 of the cell assembly 100 exposed to the outside through the opening 220 comes into physical contact with the cover 210, a short circuit will occur.

[0076] In order to eliminate such safety problems, it is preferable that an insulating block 230 for insulating the electrode unit 120 from the cover 210 is provided in the opening 220 .

[0077] Specifically, an insulating block 230 according to one embodiment of the present invention may include a body portion 231 and a slot portion 232 formed in the body portion 231 to provide a space through which the electrode portion 120 of the cell assembly 100 passes.

[0078] The shape of the slot portion 232 may correspond to that of the electrode portion 120, but since physically fixing the electrode portion 120 is not an essential function of the slot portion 232, the width or size of the slot portion 232 may be larger than that of the electrode portion 120, and may be partially open, unlike the example illustrated in the embodiment.

[0079] As described below, according to an embodiment of the present invention, when vent gas is generated from the battery cell 110 or cell assembly 100 housed inside the cell case 200, the vent gas is configured to be discharged to the outside through the slot portion 232, and in this respect, it is preferable that the size of the slot portion 232 is larger than that of the electrode portion 120.

[0080] In addition, although the drawings show the cross section of the slot portion 232 as a rectangle with a relatively long vertical length corresponding to the electrode portion 120, the cross section of the slot portion 232 may be configured to be elliptical or polygonal such as a triangle, trapezoid, hexagon, etc., so that a portion of the cross section physically supports the electrode portion 120 and another portion of the cross section forms spare space that can more effectively exhaust vent gas, as described above.

[0081] The insulating block 230, which exposes the electrode unit 120 of the cell assembly 100 to the outside, is configured to be provided in the opening 220 of the cell case 200 and maintain its position. Various methods may be used to maintain the position of the insulating block 230 in the opening 220, such as bonding, welding, adhesion, physical bonding, etc.

[0082] The insulating block 230 according to one embodiment of the present invention not only performs the basic function of an insulator or insulating member, but is also configured to function as a through hole for discharging the vent gas through the excess space between the electrode portion 120 and the slot portion 232 when vent gas is generated in the cell assembly 100 housed inside the cell case 200 as described above.

[0083] According to an embodiment of the present invention, since the insulating block 230 is provided at the front and / or rear of the cell case 200, the direction of the vent gas generated inside can be guided so that the vent gas does not flow toward adjacent cell cases 200 arranged or stacked sideways (based on the Y axis). When the discharge direction of the vent gas is guided in a specific direction in this manner, not only the discharge direction can be controlled, but also organic connection with the vent channel can be more effectively achieved.

[0084] Furthermore, when the internal pressure increases due to the generated vent gas, in order to further increase the efficiency of exhausting the vent gas, it is preferable that the insulating block 230 is configured to move outward from the opening 220 due to the internal pressure caused by the vent gas, thereby expanding the exhaust space for the vent gas.

[0085] Therefore, it is preferable that the insulating block 230 of the present invention is configured so that its position is maintained in the opening 220 but is not permanently fixed in position, and it is preferable that the insulating block 230 is provided in the opening 220 with an appropriate fixing force designed through a functional relationship with the internal pressure due to the vent gas.

[0086] Examples of such methods include a tight-fitting physical connection using the correlation between the size of the insulating block 230 and the size of the opening 220, taping that breaks or weakens when a critical value is exceeded, application of an adhesive having an adhesive strength weaker than an external force exceeding a designed standard value, adjustment of the adhesive application area, etc. In addition, since the vent gas also has high-temperature properties, a method of providing an additional member for physical connection between the opening 220 and the insulating block 230 and making the member melt at a temperature equal to or higher than a critical value may also be applied.

[0087] Hereinafter, the structure of the vent frame 370 in which the vent channel VC is formed and the operational relationship of the insulating block 230 organically combined with the vent frame 370 will be described in detail.

[0088] FIG. 6 is a diagram showing the structure of a vent frame 370 according to one embodiment of the present invention, FIGS. 7 and 8 are diagrams showing the relationship between the vent frame 370 and the cell case 200, FIG. 9 is an enlarged view of portion A in FIG. 7, and FIG. 10 is a diagram showing the operational relationship in which the insulating block 230 shown in FIG. 9 moves into the entry hole 371 of the vent frame 370.

[0089] 1, when the cell assembly 100 is composed of an overall 2×1 matrix group, the vent frame 370 may be provided between the first group and the second group. However, the vent frame 370 does not mean only a specific frame provided at a predetermined position, and one or more of the side frames 330 to 360 may be the vent frame 370 as long as it can perform the function of discharging the vent gas discharged from the inside of the cell case 200 and flowing in to the outside.

[0090] In this regard, FIG. 7 is an exemplary diagram showing a vent frame 370 provided in the central portion of the pack housing 300, and FIG. 8 is a diagram showing a structure in which one of the side frames 330 to 360 is illustrated, and the rear frame 340 functions as a vent frame.

[0091] As shown in FIG. 6, the vent frame 370 includes one or more access holes 371 formed at positions corresponding to the insulating block 230 provided in the cell casing 200, and a vent channel VC is formed therein.

[0092] The vent channel VC may be configured in a zigzag or labyrinth shape to extend the vent gas exhaust path so that the temperature of the vent gas is reduced during the exhaust process of the vent gas. In addition, when a flame is exhausted together with the vent gas, it is more preferable to provide a guide or vent rib 375 having a bent shape or the like in the vent channel so that the flame is weakened by reducing the strong straightness, which is a behavior characteristic of the flame.

[0093] As described above, when vent gas (thermal event) occurs in a particular cell assembly 100 and the internal pressure of the vent gas exceeds an appropriate level, the internal pressure causes the insulating block 230 to move outward (see FIG. 10).

[0094] As shown in the figure, the access hole 371 of the vent frame 370 is located on the outside of the insulating block 230, so that one end of the insulating block 230 naturally enters the access hole 371 without any artificial operation or complicated mechanism.

[0095] When one end of the insulating block 230 enters the inlet hole 371, a closed exhaust path is formed, as shown by the arrow in Figure 10, connecting the cell assembly 100 (or battery cell 110) where the vent gas is generated → the insulating block 230 → the inlet hole 371 of the vent frame 370 → the vent channel VC inside the vent frame 370 → an exhaust port (not shown).

[0096] In other words, the vent gas generated in a particular cell assembly 100 is discharged to the outside through a flow path that is directly connected to the vent frame 370 through the insulating block 230 provided in the corresponding cell case 200, thereby effectively suppressing the impact of the generated vent gas on other adjacent cell assemblies 100.

[0097] It is preferable that the horizontal (X-axis) length D (see FIG. 9) of the insulating block 230 (specifically, the main body 231 of the insulating block 230) is longer than the first separation distance D1 (see FIG. 9), which is the distance between the vent frame 370 and the cell case 200.

[0098] According to this embodiment of the present invention, even if one end of insulating block 230 (specifically, main body 231 of insulating block 230) enters entrance hole 371 due to internal pressure from vent gas, the other end on the opposite side of insulating block 230 does not come out of opening 220, and the above-mentioned closed exhaust path can be more effectively realized.

[0099] On the other hand, it is preferable that the inlet hole 371 be provided with a blocking member 372 that blocks or closes the inlet hole 371 unless a physical pressing force or the like is applied, so that the vent gas that flows into the vent channel VC does not flow back or is discharged through other inlet holes 371 to other cell assemblies 100.

[0100] In other words, the blocking member 372 is configured to normally physically block the access hole 371, and to open the access hole 371 by partially or completely detaching from the access hole 371 when the insulating block 230 moves.

[0101] 11 and 12 are diagrams showing an insulating block 230 according to another embodiment of the present invention. As shown in (a) and (b) of FIG. 11, it is preferable that the slot portion 232 formed in the body portion 231 of the insulating block 230 is configured such that the outer space 232A facing the entrance hole 371 formed in the vent frame 370 is smaller than the inner space 232B facing the opposite direction.

[0102] According to such an embodiment of the present invention, when the insulating block 230 recedes outward due to the internal pressure (i.e., when it enters the entrance hole 371), it is possible to more effectively secure a space for discharging the vent gas generated inside, thereby improving the discharge efficiency. Furthermore, since the area on which the internal pressure acts is increased, it is possible to further increase the driving force for leaving the opening 220, and it is possible to realize the physical behavior characteristic of the insulating block 230 moving outward more quickly.

[0103] Also, as shown in FIG. 11, it is preferable that the insulating block 230 is further configured to include a locking structure 233 formed on the other end (inner side) of the main body 231 so that the main body 231 of the insulating block 230 does not completely detach outside the opening 220 when it moves outward due to the internal pressure of the vent gas, i.e., so that the above-mentioned closed exhaust path does not collapse.

[0104] The locking structure may have various structures and shapes as long as it can prevent the other end of the main body portion 231 from coming off the opening 220, and may be a flange structure having a wider cross-sectional area than the main body portion 231, as shown in FIG. 11.

[0105] Furthermore, the main body 231 of the insulating block 230 may be configured to be composed of multiple parts 231A, 231B as shown in FIG. 12, and configured so that its length is extended (L2→L1) toward the entrance hole 371 by a sliding structure.

[0106] FIG. 13 is a diagram showing the outer structure of a cell casing 200 according to another embodiment of the present invention.

[0107] 13, the cell case 200 according to an embodiment of the present invention may further include a first coupling part 211A and a second coupling part 211B. As described above, the cell case 200 is generally hexahedral in shape, and when the cell case 200 is placed on the pack housing 300, the bottom surface may be configured as a flat surface to effectively guide the cell case 200 upright.

[0108] However, according to an embodiment, when the number of battery cells 110 housed inside the cell case 200 is small or only one, the cell case 200 has an overall slender shape extending in the longitudinal direction (X-axis direction), and therefore, even if its bottom surface is flat, it is not easy to erect it.

[0109] To solve this problem, the cover 210 of the cell case 200 may include a first coupling portion 211A and a second coupling portion 211B having an outwardly extending shape, as shown in the drawings. When the first coupling portion 211A, etc. are provided on the cover 210 in this manner, the area physically supported by the bottom surface of the pack housing 300 can be expanded, making it easier and more effective to guide the cell case 200 to stand upright.

[0110] Furthermore, as shown in the figure, the first coupling portion 211A provided on one side of the cover 210 may have a first coupling structure having a concave, convex, or a pattern in which concave and convex shapes are repeated, and the second coupling portion 211B provided on the other side of the cover 210 may have a coupling structure corresponding to the first coupling structure of the first coupling portion 211A, i.e., the coupling structures may be interlocking with each other.

[0111] According to such an embodiment of the present invention, not only is it easier to erect each of the multiple cell cases 200-1, 200-2, but it is also easier and clearer to arrange or stack adjacent cell cases 200-1, 200-2 together, thereby improving the efficiency of the process of placing multiple cell cases 200 on the pack housing 300.

[0112] FIG. 14 illustrates a pack housing 300 equipped with a heat sink 321 according to one embodiment of the present invention.

[0113] 14, a heat sink 321 for improving heat dissipation or cooling efficiency may be attached to a lower frame 320 of the frames constituting the pack housing 300. When the heat sink 321 is provided in the pack housing 300, one or more cell cases 200 of the present invention described above may be attached to the heat sink 321 in a manner that the bottom surface of the cell case 200 is in surface contact with the heat sink 321.

[0114] To further improve heat dissipation efficiency, a thermal resin may be applied to the surface of the heat sink 321. The thermal resin includes a material having high heat transfer properties and adhesiveness, and therefore can effectively transfer heat generated in the battery cell 110 or the cell assembly 100 to the heat sink 321, and can also improve the position retention of the cell case 200 when it is attached to the heat sink 321.

[0115] As shown in the figure, linear grooves 323 corresponding to the width and length of the cell case 200 may be formed on the upper surface of the heat sink 321, and guide portions 324 may be formed between the linear grooves 323.

[0116] When the linear groove 323 is formed in the heat sink 321 in this manner, the cell case 200 can be attached by being placed on the linear groove 323, which not only further improves the attachment efficiency by guiding the assembly position, but also improves the position fixing force or bonding force since the lower part of the cell case 200 is physically supported through the space of the linear groove 323.

[0117] When the cell case 200 is installed by being placed on the linear groove 323 of the heat sink 321, it is preferable that the first coupling portion 211A and the second coupling portion 211B described through FIG. 13 are provided at a position corresponding to the height of the guide portion 324 between the linear grooves 323.

[0118] The battery pack 1000 according to an embodiment of the present invention may further include a battery management system (not shown). The battery management system (BMS) may be installed in the internal space of the pack housing 300 and configured to generally control the charging and discharging operations of the battery cells 110 and the data transmission and reception operations.

[0119] Furthermore, the battery pack 1000 according to an embodiment of the present invention may further include a battery disconnect unit. The battery disconnect unit (BDU) may be configured to control an electrical connection of the battery cells to manage the power capacity and functions of the battery pack 1000. To this end, the battery disconnect unit may include a power relay, a current sensor, a fuse, and the like. The battery disconnect unit is also configured to be provided on a pack basis rather than on a module basis, and various disconnect units known at the time of filing of the present invention may be used.

[0120] In addition, the battery pack 1000 according to the present invention may further include various battery pack components known at the time of filing of the present invention. For example, the battery pack 1000 may further include a manual service disconnector (MSD) that allows an operator to manually remove a service plug to cut off the power supply.

[0121] An automobile (not shown) according to an embodiment of the present invention may include the battery pack 1000 according to the present invention. Here, the automobile (not shown) according to the present invention may be a predetermined automobile (not shown) that uses electricity as a driving source, such as an electric automobile or a hybrid automobile. Furthermore, the automobile according to the present invention may further include various components included in an automobile, such as a body and a motor, in addition to the battery pack 1000 according to the present invention.

[0122] Although the present invention has been described above using limited embodiments and drawings, the present invention is not limited thereto, and it goes without saying that various modifications and variations are possible within the scope of the technical spirit of the present invention and the scope of the claims.

[0123] The accompanying drawings for describing the present invention and illustrating related embodiments may be shown in an exaggerated form to emphasize the technology of the present invention, and it should be understood that various modifications are possible within the level of ordinary skill in the art in consideration of the above content and illustrated matters.

[0124] Furthermore, in the description of the present invention, expressions such as first, second, upper, lower, or up and down are merely terms of an instrumental concept used to relatively divide each component (element), and are not terms used to express a specific order, priority, etc., or terms used to physically divide each component (element) on an absolute basis. [Explanation of symbols]

[0125] 1000: Battery pack 100: Cell assembly 110: Battery cell 120: Electrode part 200: Cell case 210: Cover 210-1: First cover 210-2: 2nd cover 211A: 1st joint 211B:Second joint 220: Opening 230: Insulation block 231: Main body 232: Slot section 233: Locking structure (flange) 300: Pack housing 310: Top frame 320: Lower frame 330: Front frame 340: Rear frame 350: Left frame 360: Right frame 370: Bent frame 317: Entrance hole 372: Blocking member 375: Bent Rib VC: Vent Channel P: Heat shielding material

Claims

1. a cell assembly comprising one or more battery cells; a cell case that accommodates the cell assembly therein; a pack housing that houses the one or more cell cases in an internal space.

2. The cell casing comprises: a metal cover that houses the cell assembly therein; an opening formed in the cover to expose an electrode portion of the cell assembly to the outside; The battery pack according to claim 1 , further comprising: an insulating block provided in the opening for insulating the electrode portion from the cover.

3. The insulating block is A main body portion, The battery pack according to claim 2 , further comprising: a slot portion formed in the body portion to provide a space through which the electrode portion passes.

4. the pack housing further includes a vent frame having an access hole formed at a position corresponding to the insulating block, The battery pack according to claim 3 , wherein the insulating block is configured to move toward the access hole when a thermal event occurs in the cell assembly.

5. The battery pack according to claim 4 , wherein the slot portion is configured such that an outer space toward the entrance hole is smaller than an inner space in the opposite direction.

6. 5. The battery pack of claim 4, wherein the vent frame further comprises a blocking member provided at the inlet, the blocking member being partially or completely detached from the inlet to open the inlet when the insulating block moves.

7. 5. The battery pack of claim 4, wherein a horizontal length of the body portion is configured to be longer than a first separation distance, which is a distance between the vent frame and the cell casing, so that when one end of the body portion enters the entry hole due to the thermal event, the other end of the body portion does not come off the opening.

8. The battery pack according to claim 7 , wherein the insulating block further comprises a locking structure formed on the other end of the body to prevent the body from slipping out of the opening.

9. The battery pack according to claim 4 , wherein the body portion of the insulating block is configured so that its length can be extended toward the entrance hole.

10. 5. The battery pack of claim 4, wherein the vent frame includes a vent channel therein that extends or redirects a path of a vent gas.

11. The cell case cover includes: a first coupling part provided on one side and having a first coupling structure; 3. The battery pack of claim 2, further comprising: a second coupling portion provided on the other side, the second coupling portion having a coupling structure corresponding to the first coupling structure and coupled to a first coupling portion provided on a cover of another adjacent cell case.

12. A motor vehicle comprising a battery pack according to any one of claims 1 to 11.

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