Battery pack

Abstract

The present invention relates to a battery pack accommodating a plurality of cell assemblies. More specifically, the battery pack of the present invention includes a pack case providing a space in which the cell assemblies are seated, the pack case including a base plate supporting lower portions of the cell assemblies, hollow sidewalls coupled to edges of the base plate to support sides of the cell assemblies, and partition walls coupled to the base plate to define a space in the pack case, the sidewalls including a gas passage through which gas can move inside and a through-hole formed in the gas passage to connect the gas passage to the space in the pack case defined by the partition, and the sidewalls are internally coated with a protective layer including at least one of a thermal insulating material and a flame retardant.

Description

[Technical Field]

[0001] The present invention relates to a battery pack, and more particularly, the battery pack of the present invention is characterized in that a heat insulating material or a flame retardant is applied to a gas inflow passage to prevent the internal structure from collapsing due to high-temperature gas.

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0167129, filed December 2, 2022, Korean Patent Application No. 10-2023-0035444, filed March 17, 2023, and Korean Patent Application No. 10-2023-0172120, filed December 1, 2023, and all contents disclosed in the documents of said Korean patent applications are incorporated herein by reference. [Background technology]

[0003] Types of secondary batteries include lithium ion batteries, lithium polymer batteries, nickel cadmium batteries, nickel metal hydride batteries, and nickel zinc batteries. The operating voltage of such a unit secondary battery cell, i.e., a unit battery cell, is approximately 2.5V to 4.2V. Therefore, if a higher output voltage is required, a battery pack may be configured by connecting a plurality of battery cells in series. Alternatively, a battery pack may be configured by connecting a number of battery cells in parallel depending on the required charge / discharge capacity of the battery pack. Therefore, the number of battery cells included in the battery pack may be variously set depending on the required output voltage or charge / discharge capacity.

[0004] For example, when a battery pack is constructed by connecting a plurality of battery cells in series / parallel, a cell assembly including the plurality of battery cells is first constructed.

[0005] Fig. 1 shows a pack case 20 of a conventional battery pack in which pouch-type cell assemblies 10 are housed. As shown in Fig. 1, the pack case 20 can provide spaces in which the pouch-type cell assemblies 10 can be housed separately. Each pouch-type cell assembly 10 is supported at its lower portion by a base plate 30 corresponding to the bottom of the pack case 20, at its sides by side walls 40 joined along the edges of the base plate 30, and at its sides by partition walls 50, so that the pouch-type cell assemblies 10 can be separated at the same time.

[0006] 2 shows a pack case 20 in which all the pouch-type cell assemblies 10 are housed, and each pouch-type cell assembly 10 is separated by a partition wall 50. Additionally, the pack case 20 may further include a main wall 60 that crosses the center, as shown in FIG. 2, and each pouch-type cell assembly 10 is seated in an independent space by the main wall 60 and the partition wall 50.

[0007] Meanwhile, in such a battery pack with a multi-battery module structure, it is important to easily release high-temperature gases generated in each battery module. If the high-temperature gases generated during the charge and discharge process are not effectively removed, heat accumulation occurs, which can accelerate deterioration of the battery modules and, in some cases, cause fires or explosions. Furthermore, the heat from the gases can be transferred to other battery modules that are operating normally, which can cause problems such as deterioration or explosion of all battery modules housed inside the battery pack.

[0008] Conventionally, battery packs and the like have been developed that are provided with a gas flow path to allow high-temperature gas generated inside to be released to the outside as described above. However, even if a gas flow path is provided as described above, the gas flow path often melts or collapses due to the high-temperature gas, and therefore, a solution to this problem is required. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Korean Patent No. 10-2172517 Summary of the Invention [Problem to be solved by the invention]

[0010] Therefore, the present invention has been made to solve the above problems, and an object of the present invention is to provide a battery pack having a structure that can quickly discharge high-temperature gas generated inside to the outside.

[0011] Another object is to provide a battery pack whose internal structure does not easily collapse even when high-temperature gas is generated.

[0012] Other objects and advantages of the present invention can be understood from the following description and become more apparent from the embodiments of the present invention. Also, it is easily understood that the objects and advantages of the present invention can be realized by the means and combinations thereof as claimed. [Means for solving the problem]

[0013] According to the present invention, there is provided a battery pack including a pack case providing a space in which a cell assembly is seated, the pack case including a base plate supporting a lower portion of the cell assembly, and a hollow side wall coupled to an edge of the base plate to support a side of the cell assembly, the side wall including a gas flow path through which gas can move inside, and a through-hole formed in the gas flow path to connect the gas flow path to a space in the pack case, and the side wall is coated on the inside with a protective layer including at least one of a thermal insulating material and a flame retardant.

[0014] The protective layer may be formed on the gas flow path adjacent to the through-hole.

[0015] The protective layer may be formed over the entire gas flow path.

[0016] The gas flow passage may extend along the sidewall.

[0017] The sidewall may further include an exhaust hole formed on an outer surface thereof to communicate the gas passage with the outside.

[0018] The sidewall may further include an auxiliary flow path formed at a predetermined interval above the gas flow path, and an auxiliary hole formed above the through hole such that a space of the pack case communicates with the auxiliary flow path, and the protective layer may be formed on the auxiliary flow path adjacent to the auxiliary hole.

[0019] The protective layer may be formed over the entire secondary flow path.

[0020] The sidewall may further include an auxiliary discharge hole formed through an outer surface thereof to communicate the auxiliary flow path with the outside.

[0021] The pack case further includes an upper cover coupled to the side wall to cover an upper portion of the cell assembly, the upper cover including an upper flow path through which gas can move inside, and an upper hole formed on the upper flow path so that the upper flow path communicates with the space of the pack case, and the upper cover may be coated on the inside with a protective layer including at least one of a heat insulating material and a flame retardant.

[0022] The protective layer may be formed on the upper channel adjacent to the upper hole.

[0023] The protective layer may be formed over the entire upper flow channel.

[0024] The sidewall may further include a flow channel at an upper end thereof, the flow channel being open to the top, and the flow channel may be formed to extend along the gas flow path of the sidewall.

[0025] The upper cover may be coupled to the side wall such that an edge portion thereof covers an upper portion of a flow channel formed at an upper end of the side wall, and may include a communication hole at the edge portion thereof that opens to allow the flow channel to communicate with the upper flow channel.

[0026] The protective layer may be formed on the flow channel.

[0027] The sidewall may further include a discharge hole formed through an outer surface thereof to communicate with the gas passage and the auxiliary groove.

[0028] The pack case may further include a hollow main wall that crosses a center and is coupled to the base plate, the main wall including a main flow path through which gas can move and a main hole formed on the main flow path such that the main flow path communicates with a space in the pack case, and the protective layer may be formed on the main flow path adjacent to the main hole.

[0029] At least one of the front end and the rear end of the main wall may be opened so that the main flow path communicates with the outside. [Effects of the Invention]

[0030] According to the present invention, in a battery pack containing a plurality of cell assemblies, the stability can be improved by preventing the collapse of the internal structure caused by high-temperature gas. [Brief explanation of the drawings]

[0031] [Figure 1] 1 shows a pack case included in a conventional battery pack. [Figure 2] 1 shows a conventional pack case containing a cell assembly. [Figure 3] 1 is a perspective view of a pack case included in a battery pack according to a first embodiment of the present invention; [Figure 4] 1A and 1B are a partial perspective view and a partial cross-sectional view of a pack case with an upper cover removed. [Figure 5]The following shows an example of a protective layer formed on a pack case. [Figure 6] This shows a part of the pack case in Figure 3 cut away. [Figure 7] This shows the movement of high-temperature gas when it is generated in the internal space of the pack case shown in FIG. [Figure 8] 1 shows the path of gas moving along the gas flow path inside the side wall. [Figure 9] 10A and 10B are a cross-sectional perspective view and a cross-sectional view of a portion of a side wall included in a battery pack according to a second embodiment. [Figure 10] The figure shows the migration path of the gas that has flowed into the auxiliary flow path via the auxiliary hole. [Figure 11] FIG. 10 is a cross-sectional perspective view of a portion of a battery pack according to a third embodiment. [Figure 12] This shows the battery pack of FIG. 11 with the top cover removed. [Figure 13] 12 shows the path of gas moving through the upper flow passage in the battery pack of FIG. 11. [Figure 14] FIG. 2 is a cross-sectional perspective view of a portion of the battery pack. [Figure 15] 1 shows a part of the pack case with the top cover removed and a partial cross section. [Figure 16] This shows the movement of the gas when high-temperature gas is generated in the internal space of the pack case. [Figure 17] This shows the path that high-temperature gas generated inside the pack case travels through the main wall. DETAILED DESCRIPTION OF THE INVENTION

[0032] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Before that, the terms and words used in the specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted as meanings and concepts that are consistent with the technical idea of ​​the present invention based on the principle that the inventor can appropriately define the concepts of the terms to best describe his own invention.

[0033] Therefore, 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 idea of ​​the present invention, and there may be various equivalents and modifications that can replace them at the time of this application.

[0034] Furthermore, in the description of the present invention, if it is determined that a detailed description of related publicly known structures or functions may obscure the gist of the present invention, the detailed description will be omitted.

[0035] The embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art, and therefore the shapes and sizes of components in the drawings may be exaggerated, omitted, or shown in a schematic manner for clearer explanation. Therefore, the sizes and proportions of each component do not completely reflect the actual sizes and proportions.

[0036] The present invention relates to a battery pack accommodating a plurality of cell assemblies. More specifically, the battery pack of the present invention is characterized in that a heat insulating material or a flame retardant is applied to a gas inflow passage to prevent the internal structure from collapsing due to high-temperature gas.

[0037] The cell assembly used in the present invention includes a cell block containing a plurality of cells.

[0038] The cell includes an electrode assembly in which electrodes including anodes and cathodes and separators are alternately stacked, electrode leads electrically connected to the electrodes, and a battery case that encloses and seals the electrode assembly so that the electrode leads can be led out.

[0039] The cells can be classified into cylindrical cells, prismatic cells, and pouch cells depending on the shape of the electrode assembly and the battery case.

[0040] The cylindrical cell has an electrode assembly wound into a roll and inserted into a cylindrical battery case.

[0041] The prismatic cell may be in a stack form in which the electrode assembly is stacked by alternately stacking electrodes and separators, or in a stack-fold form in which electrodes and the like are provided on a sheet-like separator folded at regular intervals.

[0042] In the prismatic cell, the electrode assembly is inserted into a square box-shaped battery case.

[0043] The pouch-type cell may have an electrode assembly in a stacked form or a stack-folded form.

[0044] In the pouch-type cell, the electrode assembly is inserted into a pouch-shaped battery case.

[0045] Therefore, the cell assembly may include any one of cylindrical cells, prismatic cells, and pouch cells.

[0046] The cell assembly includes a plurality of cells and a bus bar frame including bus bars electrically connected to electrode leads included in each of the cells.

[0047] The cell assembly may further include a module frame surrounding the periphery of the cell block to protect each cell from external impact. In this case, the module frame may be provided to support or protect only a portion of the cell block, or may be provided on all exposed portions of the cell block to completely isolate the cell block from the outside.

[0048] Figures 3 to 8 relate to a battery pack according to a first embodiment of the present invention, Figures 9 to 10 relate to a battery pack according to a second embodiment of the present invention, Figures 11 to 13 relate to a battery pack according to a third embodiment of the present invention, and Figures 14 to 17 relate to a battery pack according to a fourth embodiment of the present invention.

[0049] Hereinafter, a battery pack according to each embodiment of the present invention will be described with reference to the drawings.

[0050] (First embodiment) FIG. 3 is a perspective view of a pack case 1000 included in the battery pack according to the first embodiment of the present invention, and FIG. 4 is a partial perspective view and a partial cross-sectional view of the pack case 1000 with the upper cover 500 removed.

[0051] The battery pack of the present invention includes a pack case 1000 that provides a space in which the cell assembly is seated.

[0052] The pack case 1000 includes a base plate 100 and a side wall 200 .

[0053] The cell assembly is seated in an internal space formed by the combination of the base plate 100 and the side wall 200 .

[0054] Furthermore, the pack case 1000 may further include a partition wall 300 and an upper cover 500, if necessary. The pack case 1000 may further include a main wall 400 that divides the internal space into two large areas.

[0055] The base plate 100 serves to support the lower portion of each cell assembly housed in the pack case 1000 .

[0056] The base plate 100 may be provided with cooling channels through which a cooling fluid flows to prevent overheating of the cell assembly housed therein, if necessary.

[0057] The partition walls 300 separate the plurality of cell assemblies mounted on the base plate 100 and support the sides of the separated cell assemblies.

[0058] As shown in FIG. 4, the partition walls 300 are coupled to the base plate 100 at predetermined intervals along the longitudinal direction d1 of the pack case 1000.

[0059] The partition walls 300 divide the internal space of the pack case 1000, and allow the cell assemblies to be separately mounted in each of the divided spaces.

[0060] The side walls 200 support the sides of the cell assembly mounted on the base plate 100 and protect it from external impacts.

[0061] The side wall 200 is coupled along the edge of the base plate 100 .

[0062] The sidewall 200 has a hollow structure, and gas can move through the hollow. Specifically, as shown in Fig. 4, the sidewall 200 includes a gas passage 220 through which gas can move inside, and through-holes 210 formed on the gas passage 220 to communicate with the interior space of the pack case 1000. Therefore, when one of the plurality of cell assemblies housed inside the pack case 1000 deteriorates and releases high-temperature gas, the gas can flow into the gas passage 220 through the through-holes 210 formed on the inner surface of the sidewall 200.

[0063] The gas flow passage 220 may be formed to extend along the sidewall 200 .

[0064] Since one sidewall 200 is adjacent to a plurality of spaces partitioned by the partition walls 300, a plurality of through-holes 210 spaced apart at predetermined intervals may be formed on one gas passage 220.

[0065] The sidewall 200 further includes exhaust holes 230 formed on the outer surface thereof to communicate the gas passage 220 with the outside, and gas moving through the gas passage 220 can be exhausted to the outside through the exhaust holes 230.

[0066] The top cover 500 may be coupled to the side wall 200 to cover the top of the cell stuff assembly mounted on the base plate 100. More specifically, the top cover 500 may be coupled to the top end of the side wall 200, the edge of which is formed in a square frame shape on the base plate 100. Additionally, the top cover 500 may be screwed to the top end of each partition wall 300 for more stable coupling.

[0067] The upper cover 500 serves to protect the upper portion of each cell assembly from external impact.

[0068] 4, the pack case 1000 may further include a main wall 400 that crosses the center and is coupled to the base plate 100. In this case, both ends of the partition wall 300 are coupled to the main wall 400 and the side wall 200, respectively, to define an internal space of the pack case 1000.

[0069] The battery pack of the present invention is characterized in that the pack case 1000 is coated with a protective layer C including at least one of a heat insulating material C2 and a flame retardant C1. For example, the protective layer C may be applied to a side wall 200 included in the pack case 1000.

[0070] The protective layer C can be formed by applying a slurry-like heat insulating material C2 or a flame retardant C1 onto the surface of the target area.

[0071] The insulating material C2 may include at least one of organic and inorganic materials. For example, the insulating material C2 may be cork, cotton, felt, carbide, rubber, asbestos, glass wool, quartz wool, diatomaceous earth, magnesium carbonate powder, etc. However, the types of the insulating material C2 are not limited to those listed above, and any material that has low thermal conductivity or can block heat transfer may be used.

[0072] The flame retardant C1 may include at least one of a halogen-based flame retardant C1, a phosphorus-based flame retardant C1, and an inorganic compound flame retardant C1. For example, the flame retardant C1 may be tribromophenoxyethane, tetrabromobisphenol-A (TBBA), octabromodiphenyl ether, calcium bromide, brominated epoxy oligomer, brominated polycarbonate oligomer, chlorinated paraffin, chlorinated polyethylene, alicyclic chlorine-based flame retardant C1, red phosphorus, ammonium phosphate, aluminum hydroxide, magnesium hydroxide, boric acid, antimony oxide, tin hydroxide, tin oxide, molybdenum oxide, zirconium compound, borate, calcium salt, etc. However, the types of the flame retardant C1 are not limited to those listed above, and any flame retardant that can inhibit combustion may be used.

[0073] FIG. 5 shows an example of the protective layer C formed on the pack case 1000.

[0074] The protective layer C may contain only a flame retardant C1 as shown in Fig. 5(a) or only a heat insulating material C2 as shown in Fig. 5(b). Alternatively, it may contain both the flame retardant C1 and the heat insulating material C2. In this case, it is preferable that the flame retardant C1, which prevents combustion, is located on the outside and the heat insulating material C2, which prevents heat transfer, is interposed between the pack case 1000 and the flame retardant C1.

[0075] More specifically, the protective layer C is formed on the gas flow passage 220.

[0076] The protective layer C is applied to protect the gas flow passage 220 from the high heat transmitted by the high-temperature gas.

[0077] Generally, the gas generated from a thermal runaway cell assembly has a very high temperature, and therefore, any structure that the gas first comes into contact with is at high risk of melting or collapsing due to the high heat.

[0078] The protective layer C is formed on the gas flow path 220 adjacent to the through-hole 210 for the purpose of protecting the gas flow path 220 with which the high-temperature gas that has passed through the through-hole 210 comes into contact relatively early.

[0079] Referring to the partial cross-sectional view of FIG. 4, a protective layer C is coated on a part of the inner surface of the gas flow passage 220 .

[0080] FIG. 6 shows a part of the pack case 1000 of FIG. 3 cut away (however, for ease of understanding, the cell assembly is omitted in FIG. 7).

[0081] 6, the protective layer C is formed on the inner surface of the gas flow passage 220 exposed through the through-hole 210. As shown in FIG.

[0082] FIG. 7 is a simplified diagram showing the movement G of the gas when high-temperature gas is generated in the internal space of the pack case 1000 shown in FIG.

[0083] 7, high-temperature gas is generated in the partitioned space and moves through the through-holes 210 and gas flow passage 220. At this time, the gas first comes into contact with the protective layer C formed on the wall surface of the gas flow passage 220 exposed through the through-holes 210.

[0084] The protective layer C protects the gas flow passage 220 inside the side wall 200 from the heat of the gas.

[0085] FIG. 8 shows the path G of gas movement along the gas flow passage 220 inside the side wall 200.

[0086] 8, the gas flows into the gas passage 220 through the through-holes 210 in each partition space, then travels through the gas passage 220 formed along the sidewall 200, and is then discharged to the outside through the discharge holes 230.

[0087] The protective layer C may be formed on the gas passage 220 adjacent to the through-hole 210 as shown in FIGS. 6 to 8, or may be formed over the entire gas passage 220.

[0088] (Second embodiment) In the battery pack according to the second embodiment of the present invention, in addition to the gas flow passage 220, an auxiliary flow passage 250 that can assist the function of the gas flow passage 220 is additionally formed in the side wall 200.

[0089] FIG. 9 is a cross-sectional perspective view and a cross-sectional view of a portion of a side wall 200 included in a battery pack according to the second embodiment.

[0090] As shown in FIG. 9, the side wall 200 further includes auxiliary channels 250 formed at predetermined intervals above the gas channels 220, and auxiliary holes 240 formed above the through holes 210.

[0091] The auxiliary holes 240 and the auxiliary channels 250 may be applied to assist the functions of the through-holes 210 and the gas channels 220. Therefore, the diameters and sizes of the auxiliary holes 240 and the auxiliary channels 250 may be smaller than those of the through-holes 210 and the gas channels 220.

[0092] The auxiliary hole 240 is formed on the auxiliary flow path 250 to connect the auxiliary flow path 250 to the space of the pack case 1000 .

[0093] The gas flowing into the auxiliary channel 250 through the auxiliary holes 240 may be discharged to the outside via a path different from that of the gas flowing into the gas channel 220. That is, as shown in FIG. 9, the side wall 200 may further include auxiliary discharge holes 260 formed on the outer surface thereof so as to communicate the auxiliary channel 250 with the outside.

[0094] The auxiliary discharge hole 260 is formed on the auxiliary flow path 250 so that the auxiliary flow path 250 communicates with the outside.

[0095] FIG. 10 shows the path G of gas flowing into the auxiliary flow path 250 through the auxiliary hole 240. As shown in FIG.

[0096] Referring to FIG. 10, high-temperature gas generated in the internal space of the pack case 1000 flows into the gas flow passage 220 and the auxiliary flow passage 250 via the through-holes 210 and the auxiliary holes 240, respectively.

[0097] The gas flowing into the auxiliary flow path 250 through the auxiliary holes 240 moves through the auxiliary flow path 250 and can be quickly discharged to the outside through any one of the auxiliary discharge holes 260 connected to the auxiliary flow path 250.

[0098] A plurality of auxiliary holes 240 may be formed on the single auxiliary flow path 250 .

[0099] The battery pack according to the second embodiment is characterized in that the protective layer C is also formed on the auxiliary channel 250. Preferably, the protective layer C is formed on the auxiliary channel 250 adjacent to the auxiliary hole 240.

[0100] 9 and 10, the protective layer C is coated on the auxiliary flow passage 250 exposed through the auxiliary hole 240.

[0101] The protective layer C may be formed by coating the entire auxiliary passage 250 in the same manner as the gas passage 220 .

[0102] (Third embodiment) In the battery pack according to the third embodiment of the present invention, a flow path through which gas moves is formed in the upper cover 500.

[0103] Specifically, the upper cover 500 includes an upper passage 520 through which gas can move, and an upper hole 510 formed on the upper passage 520 .

[0104] FIG. 11 is a cross-sectional perspective view of a portion of a battery pack according to the third embodiment.

[0105] As shown in FIG. 11, the upper cover 500 includes an upper passage 520 through which gas can move inside, and an upper hole 510 formed on the upper passage 520 so that the upper passage 520 communicates with the space of the pack case 1000.

[0106] The upper flow passage 520 may be formed to extend along the width direction d2 of the pack case 1000 as shown in the figure, or may be formed to extend along the longitudinal direction d1 of the pack case 1000, or may be formed in various shapes extending in a zigzag shape along the width direction d2 and the longitudinal direction d1 of the pack case 1000.

[0107] As shown in FIG. 11, an upper hole 510 connected to an upper passage 520 may be formed at the lower end of the upper cover 500, and the upper hole 510 is opened downward so that high-temperature gas generated in the cell assembly located below can flow into the upper passage 520.

[0108] The gas flowing in through the upper cover 500 may move inside the upper cover 500 along the upper flow passage 520 and then move to the side wall 200. Therefore, in this case, a separate flow passage communicating with the upper flow passage 520 of the upper cover 500 may be formed in the side wall 200.

[0109] FIG. 12 shows the battery pack of FIG. 11 with the top cover 500 removed.

[0110] Referring to FIG. 12, the sidewall 200 further includes a flow channel 270 at an upper end thereof, the flow channel 270 being open upward, and the flow channel 270 is formed to extend along the gas flow channel 220 of the sidewall 200 .

[0111] The upper cover 500 includes a communication hole 530 at its edge, which is opened so that the flow channel 270 and the upper flow channel 520 communicate with each other.

[0112] The upper cover 500 is coupled to the side wall 200 such that its edge covers the upper portion of the flow channel 270 formed at the upper end of the side wall 200, and includes a communication hole 530 at the edge that is opened to allow the flow channel 270 to communicate with the upper flow channel 520.

[0113] As shown in FIG. 11, the upper cover 500 has an edge connected to the upper end of the side wall 200 so that the flow channel 270 communicates with the upper flow channel 520 .

[0114] The upper cover 500 is characterized in that the inside thereof is coated with a protective layer C containing at least one of a heat insulating material C2 and a flame retardant C1.

[0115] 11, the protective layer C may be coated on one side of the upper channel 520 exposed through the upper hole 510. More specifically, the protective layer C is formed on the upper channel 520 adjacent to the upper hole 510.

[0116] The protective layer C may be formed by coating the entire upper channel 520 .

[0117] According to the present invention, the protective layer C may be formed on the flow channel 270 as shown in Fig. 12. Therefore, the flow channel 270 inside the side wall 200 may be protected from high-temperature gas moving through the upper flow channel 520 by the protective layer C.

[0118] FIG. 13 shows a path G of gas movement through the upper flow passage 520 in the battery pack of FIG.

[0119] 13, high-temperature gas flowing into upper passage 520 through upper hole 510 moves along upper passage 520 to the end of upper cover 500. At this time, protective layer C coated on upper passage 520 adjacent to upper hole 510 protects upper passage 520 by preventing it from burning or overheating due to the high-temperature gas flowing in through upper hole 510.

[0120] The gas that has moved to the end of the upper cover 500 flows into the flow channel 270 of the side wall 200 that is connected to the end of the upper cover 500 through the communication hole 530, and moves along the flow channel 270. In this case, if a protective layer C is coated on the surface of the flow channel 270 adjacent to the communication hole 530, the protective layer C can also protect the flow channel 270 from the high-temperature gas.

[0121] Similar to the first embodiment, the sidewall 200 may further include exhaust holes 230 that connect the gas passage 220 to the outside, and in this case, the exhaust holes 230 are also connected to a flow channel 270 formed on the upper portion of the gas passage 220. Therefore, high-temperature gas moving along the flow channel 270 and the gas passage 220 can be exhausted to the outside through the exhaust holes 230.

[0122] (Fourth embodiment) The battery pack according to the fourth embodiment of the present invention includes a hollow main wall 400 .

[0123] FIG. 14 is a cross-sectional perspective view of a portion of the battery pack, and FIG. 15 shows a portion and a partial cross section of the pack case 1000 with the top cover 500 removed.

[0124] Referring to FIG. 14, the main wall 400 includes a main flow path 410 through which gas can move, and a main hole 420 formed on the main flow path 410 so that the main flow path 410 communicates with the space of the pack case 1000 partitioned by the partition wall 300.

[0125] The main flow channel 410 is formed to extend horizontally along the main wall 400 .

[0126] The protective layer C of the present invention may be formed on the main channel 410. Preferably, the protective layer C is formed on the main channel 410 adjacent to the main hole 420.

[0127] Specifically, as shown in FIG. 15, the main wall 400 protrudes vertically and extends along the longitudinal direction d1 of the pack case 1000. The main wall 400 is composed of a separation portion 400a that divides the internal space of the pack case 1000 in half, a bottom portion 400c that is coupled to the lower end of the separation portion 400a to support the lower portion of the separation portion 400a, and a pair of cover portions 400b that are coupled to the separation portion 400a and the bottom portion 400c to form a hollow space inside on both sides of the separation portion 400a.

[0128] The protective layer C may be coated on both sides of the separating portion 400a.

[0129] The high-temperature gas flowing into the main passage 410 through the main hole 420 moves through the main passage 410 and can be discharged to the outside.

[0130] 16 and 17 are simplified diagrams showing the path along which high-temperature gas generated inside the pack case 1000 travels through the main wall 400. FIG.

[0131] The high-temperature gas flows into the main channel 410 formed by the cover part 400b and the separation part 400a through the main hole 420. Then, the gas moves through the main channel 410 formed along the main wall 400.

[0132] At least one of the front end and the rear end of the main wall 400 may be opened. More specifically, at least one of the front end and the rear end of the main wall 400 may be opened so that the main flow path 410 communicates with the outside, and gas moving through the main flow path 410 may be discharged to the outside through the opened end of the main wall 400.

[0133] 17, the front end of the main wall 400 is opened, and the main flow path 410 is exposed to the outside through the front end. High-temperature gas generated inside the pack case 1000 flows into the main flow path 410 through the main hole 420, moves to the front end of the main wall 400, and can be discharged through the opening at the front end of the main wall 400.

[0134] The present invention has been described in more detail above through the drawings and embodiments, etc. However, the configurations described in the drawings or embodiments in this specification are merely one embodiment of the present invention and do not represent all of the technical ideas of the present invention, and therefore, there may be various equivalents and modifications that can replace them at the time of filing this application. [Explanation of symbols]

[0135] 10: (Prior Art) Pouch-type cell assembly 20: (Conventional technology) Pack case 30: (Prior Art) Base Plate 40: (Prior Art) Sidewall 50: (Conventional) Partition 60: (Conventional technology) Main wall 1000: Pack case 100: Base plate 200: Side wall 210:Through hole 220: Gas flow path 230: Discharge hole 240: Auxiliary Hall 250: Auxiliary flow path 260: Auxiliary discharge hole 270: Flow channel 300: Bulkhead 400: Main wall 400a: Separation part 400b: Cover part 400c: bottom 410: Main flow path 420: Main Hall 500: Top cover 510: Upper hall 520: Upper flow channel 530: Connecting hole C: Protective layer C1: Flame retardant C2: Insulation G: Gas transfer d1: Longitudinal direction of pack case d2: Width direction of pack case

Claims

1. In a battery pack containing a plurality of cell assemblies, A pack case is provided to provide a space in which the cell assembly is seated. The pack case is a base plate supporting a lower portion of the cell assembly; a hollow sidewall coupled along an edge of the base plate to support the sides of the cell assembly; the side wall includes a gas flow path through which gas moves inside, and a through-hole formed in the gas flow path so that the gas flow path communicates with a space in the pack case, The side wall is internally coated with a protective layer including at least one of a thermal insulating material and a flame retardant.

2. The battery pack according to claim 1 , wherein the protective layer is formed on the gas flow path adjacent to the through-hole.

3. The battery pack according to claim 1 , wherein the protective layer is formed over the entire gas flow path.

4. The battery pack according to claim 1 , wherein the gas flow passage extends along the side wall.

5. The battery pack of claim 1 , wherein the sidewall further includes a vent hole formed on an outer surface thereof to communicate the gas passage with the outside.

6. the sidewall further includes an auxiliary passage formed above the gas passage at a predetermined interval, and an auxiliary hole formed above the through hole such that a space of the pack case communicates with the auxiliary passage, The battery pack according to claim 1 , wherein the protective layer is formed on an auxiliary flow path adjacent to the auxiliary hole.

7. The battery pack according to claim 6 , wherein the protective layer is formed over the entire auxiliary flow path.

8. The battery pack of claim 6, wherein the side wall further comprises an auxiliary discharge hole formed on an outer surface thereof to communicate the auxiliary flow path with the outside.

9. the pack case further includes an upper cover coupled to the side wall to cover an upper portion of the cell assembly; the upper cover includes an upper passage through which gas moves inside, and an upper hole formed on the upper passage such that the upper passage communicates with a space of the pack case, The battery pack according to claim 1 , wherein the upper cover is internally coated with a protective layer including at least one of a thermal insulating material and a flame retardant.

10. The battery pack according to claim 9 , wherein the protective layer is formed on an upper channel adjacent to the upper hole.

11. The battery pack according to claim 9 , wherein the protective layer is formed over the entire upper channel.

12. The sidewall further includes a flow channel at an upper end thereof, the flow channel being open at an upper end thereof, The battery pack according to claim 9 , wherein the flow channel extends along the gas flow channel of the side wall.

13. 13. The battery pack of claim 12, wherein the upper cover is coupled to the side wall such that an edge portion thereof covers an upper portion of a flow channel formed at an upper end of the side wall, and the edge portion includes a communication hole that opens to allow communication between the flow channel and an upper flow channel.

14. The battery pack according to claim 12 , wherein the protective layer is formed on the flow channel.

15. The battery pack of claim 12 , wherein the sidewall further includes a vent hole formed on an outer surface thereof to penetrate the gas passage and communicate with the auxiliary groove.

16. the pack case further includes a hollow main wall that traverses a center portion and is coupled to the base plate; the main wall includes a main flow path through which gas moves inside, and a main hole formed in the main flow path such that the main flow path communicates with a space in the pack case, The battery pack according to claim 1 , wherein the protective layer is formed on a main flow path adjacent to the main hole.

17. The battery pack according to claim 16 , wherein at least one of a front end and a rear end of the main wall is opened so that the main flow path communicates with the outside.

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