Battery pack and vehicle including same

Abstract

A battery pack and a vehicle including the same are disclosed. The battery pack according to an embodiment of the present invention includes a cell unit including at least one battery cell, and a case including an accommodation room having a bottom surface on which the cell unit is placed and accommodating the cell unit in the accommodation room, the bottom surface including a pocket configured to capture a mass that is ejected and falls from a battery cell included in the cell unit.

Description

[Technical Field]

[0001] This application claims priority based on Korean Patent Application No. 10-2022-0110386 filed on August 31, 2022, and Korean Patent Application No. 10-2023-0065197 filed on May 19, 2023, the entire contents of which are incorporated herein by reference in their entirety in their specifications and drawings.

[0002] The present invention relates to a battery assembly, a battery pack including the same, and a vehicle, and more particularly to a battery pack manufactured by a cell-to-pack method and a vehicle including the same. [Background technology]

[0003] Generally, a secondary battery refers to a battery that can be repeatedly charged and discharged, such as a lithium-ion battery, lithium polymer battery, nickel-cadmium battery, nickel-metal hydride battery, nickel-zinc battery, etc. The output voltage of a battery cell, which corresponds to the basic unit of charge and discharge of such a secondary battery, is approximately 2.5V to 4.2V.

[0004] In recent years, as secondary batteries are applied to devices requiring high output voltage and large charging capacity, such as electric vehicles and energy storage systems (ESS), battery packs manufactured by connecting a plurality of battery cells in series or parallel to form a battery module and then connecting the thus-formed battery modules again in series or parallel have become widely used.

[0005] However, as disclosed in Korean Patent Publication No. 10-2379227 and Korean Patent Publication No. 10-2022-0052183, existing technologies manufacture battery packs by accommodating battery cells in a box-shaped metal case to form a battery module, and then accommodating this battery module in a battery pack case. This increases the weight and volume of the entire battery pack and reduces the energy density of the battery pack.

[0006] In addition, when the existing cell-to-pack method, in which multiple battery cells are directly attached to a battery pack case to increase the energy density of the battery pack, is applied to a pouch-type secondary battery with a soft case, it is difficult to handle or stack multiple battery cells at the same time, and there is a risk of the battery cells being damaged during the process of attaching them to the pack case.

[0007] Furthermore, the existing cell-to-pack method has the problem that, because multiple battery cells are densely packed in a spatially concentrated manner inside a pack case, it is difficult to exhaust gases and flames generated when a battery cell experiences thermal runaway in the intended direction. Therefore, if thermal runaway occurs in some battery cells, it can lead to a chain reaction of thermal runaway in the remaining battery cells.

[0008] In addition, with existing technologies, when thermal runaway occurs in a battery cell, particles and foreign matter emitted from the battery cell accumulate inside the battery pack, making it difficult to smoothly release gas. This also increases the internal pressure of the battery pack, which can lead to damage or explosion of the battery pack. Summary of the Invention [Problem to be solved by the invention]

[0009] The technical problem to be solved by the present invention is to provide a battery pack and a vehicle including the same, which can reduce the overall weight and volume of the battery pack, increase the energy density, and enable safe and easy handling and installation of battery cells during battery pack manufacturing.

[0010] Another technical problem to be solved by the present invention is to provide a battery pack and a vehicle including the same that prevent structural damage or explosion of the battery pack when thermal runaway occurs in a battery cell and suppress chain reaction of thermal runaway between battery cells. [Means for solving the problem]

[0011] A battery pack according to one embodiment of the present invention includes a cell unit including at least one battery cell, and a case having a storage room with a bottom surface on which the cell unit is placed, the case storing the cell unit in the storage room, the bottom surface including a pocket configured to collect mass that falls from a battery cell included in the cell unit.

[0012] In one embodiment, the cell unit may further include a cell cover that includes a slot into which the at least one battery cell is inserted and an opening through which an electrode lead of the at least one battery cell inserted into the slot is exposed, and that covers the at least one battery cell inserted into the slot.

[0013] In one embodiment, the cell cover is arranged so that the entrance of the slot faces the bottom surface portion, and the entrance of the pocket can be provided at a position corresponding to the entrance of the slot.

[0014] In one embodiment, the entrance of the pocket may be provided at a position corresponding to a portion of the entrance of the slot that is adjacent to an electrode lead of the at least one battery cell.

[0015] In one embodiment, the cell unit may further include a bus bar electrically connected to the electrode lead, and a bus bar frame disposed in the opening of the cell cover to support the bus bar.

[0016] In one embodiment, the base portion further includes a gas passage extending along an interior of the base portion, and the pocket may be configured to be in communication with the gas passage.

[0017] In one embodiment, the bottom portion further includes a barrier membrane that blocks the inlet of the gas passage connected to the pocket, and the barrier membrane may be configured to rupture when the surrounding pressure rises above a predetermined pressure, thereby opening the inlet of the gas passage.

[0018] In one embodiment, the battery pack further includes a heat sink disposed between the cell unit and the bottom portion to cool the battery cells included in the cell unit, and the heat sink may include a guide hole provided in a portion of the heat sink corresponding to an entrance of the pocket to guide the mass to the entrance of the pocket.

[0019] In one embodiment, the guide hole may be configured to gradually widen as it progresses from the pocket side toward the cell unit side.

[0020] In one embodiment, the battery pack may further include a thermal interface material (TIM) that is a thermally conductive material interposed between the cell unit and the heat sink.

[0021] In one embodiment, the battery pack includes a plurality of the cell units, and the plurality of cell units may be stacked on top of each other in one direction.

[0022] In one embodiment, the at least one battery cell may be comprised of a pouch-type secondary battery.

[0023] A vehicle according to another aspect of the present invention includes a battery pack according to any one of the above-described embodiments. [Effects of the Invention]

[0024] According to the present invention, a pocket configured to capture mass that is ejected from a battery cell and falls under its own weight is provided on the bottom surface of the battery pack case, thereby facilitating the release of gas when thermal runaway occurs in the battery cell and preventing damage or explosion of the battery pack due to an increase in internal pressure of the battery pack.

[0025] In addition, instead of a plurality of battery cells being housed in a separate module case and then attached to the battery pack case, the battery cells are only partially covered by a cell cover with a simplified structure and then directly attached to the battery pack case, thereby reducing the weight and volume of the entire battery pack and increasing the energy density of the battery pack, while facilitating safe handling and attachment of the battery cells during battery pack manufacturing and reducing manufacturing costs.

[0026] Furthermore, a gas passage communicating with the pocket is provided at the bottom of the battery pack case, thereby diversifying the gas vent paths inside the battery pack and providing an alternative path when other gas vent paths are blocked.

[0027] Furthermore, gas that has traveled through a gas passage provided in the bottom portion of the battery pack case or another gas passage provided in the wall of the case is discharged in a predetermined direction by a gas valve, so that the gas vent direction of a battery pack mounted on the bottom of a vehicle can be set to the rear or side rather than above where the occupants are located, thereby ensuring the safety of the occupants.

[0028] Furthermore, the blocking portion of the cell cover supports the battery cell inserted in the slot of the cell cover and blocks the removal of the battery cell, thereby preventing the battery cell from being displaced or the cell cover from being detached to the outside, thereby ensuring the safety and reliability of the battery pack.

[0029] In addition, an insertion groove is provided in the blocking portion of the cell cover to facilitate the insertion of a tool that comes into contact with the inner surface of the cell cover to change the slot width of the cell cover, thereby facilitating the process of inserting the battery cell into the cell cover and preventing damage to the battery cell.

[0030] Furthermore, it should be clear to those skilled in the art that the various embodiments of the present invention can solve various technical problems not mentioned above. [Brief explanation of the drawings]

[0031] [Figure 1] 1 illustrates a battery pack according to one embodiment of the present invention. [Figure 2] FIG. 2 is an exploded view showing a battery assembly of a battery pack according to an embodiment of the present invention. [Figure 3] FIG. 2 is an enlarged view showing the M1 region of FIG. [Figure 4] 1 is a diagram showing a cell unit of a battery pack according to an embodiment of the present invention; [Figure 5] FIG. 5 is an exploded view showing the cell unit shown in FIG. [Figure 6] 2 is a cross-sectional view taken along line A1-A1' of the battery pack shown in FIG. [Figure 7] FIG. 7 is a diagram showing the lower end portion of the cell unit shown in FIG. [Figure 8] FIG. 5 is a diagram showing an assembly method of the cell unit shown in FIG. [Figure 9] FIG. 5 is a diagram showing an assembly method of the cell unit shown in FIG. [Figure 10] FIG. 10 shows a cell cover according to an alternative embodiment. [Figure 11] FIG. 10 shows a cell cover according to another modified embodiment. [Figure 12] 1 is a diagram illustrating a vehicle according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0032] In order to clarify the solution to the technical problem of the present invention, the following embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, in describing the present invention, if it is deemed that a description of known technologies related to the present invention may unnecessarily obscure the gist of the present invention, the description of such technologies may be omitted. Furthermore, the terms used in describing the present invention are defined in consideration of the functions of the present invention, and these terms may vary depending on the intentions or practices of designers, manufacturers, etc. Therefore, it is appropriate that the definitions of the terms described below be defined in light of the overall content of this specification.

[0033] For reference, terms indicating directions in this specification are terms based on the components shown in the accompanying drawings, and are relative terms that can be changed depending on the attitude and position of the actual components.

[0034] FIG. 1 shows a battery pack 10 according to one embodiment of the present invention.

[0035] As shown in FIG. 1, the battery pack 10 includes a battery assembly 100 and a case 300 that houses one or more battery assemblies 100.

[0036] The battery assembly 100 also includes a plurality of cell units 200. Each cell unit 200 includes at least one battery cell and a cell cover that partially encloses and covers the at least one battery cell, and may be stacked in the width direction (Y-axis direction) with other cell units.

[0037] The battery cell included in each cell unit 200 may be configured as a pouch-type secondary battery. In this case, the pouch-type secondary battery may be manufactured by placing an electrode assembly and an electrolyte in a pouch-type case and sealing the case. Depending on the embodiment, the battery cell may be configured in various shapes, such as a prismatic secondary battery or a cylindrical secondary battery.

[0038] A plurality of such cell units 200 can be stacked in one direction and housed in the case 300 .

[0039] The case 300 includes one or more storage rooms R1 each having a bottom surface 310 on which the cell unit 200 is placed, and stores the cell unit 200 in the storage rooms R1. For example, the case 300 may be configured to store multiple battery assemblies 100 in separate storage rooms.

[0040] For this purpose, the case 300 may include a lower case 302 having an opening at its upper end and an internal space connected to the opening, and an upper case 304 covering the opening of the lower case 302 .

[0041] The lower case 302 may include walls 312 that divide the interior space into a plurality of storage rooms R1. A gas inlet 314 through which gas generated in the battery assembly 100 stored in the storage room R1 flows may be provided in the wall 312 of the lower case 302 adjacent to the storage room R1. A gas valve 316 for discharging gas may be provided on the outer surface of the lower case 302. A gas passage connecting the gas inlet 314 and the gas valve 316 may be provided inside the lower case 302.

[0042] In this case, a gas vent path for discharging gas by gas valve 316 may be provided individually for each storage room. That is, gas generated in a first storage room may be discharged through a first gas vent path connected to a first gas inlet, a first gas passage, and a first gas valve, and gas generated in a second storage room may be discharged through a second gas vent path connected to a second gas inlet, a second gas channel, and a second gas valve.

[0043] As will be described again later, the bottom portion 310 of the storage room R1 may include a pocket 310a configured to collect mass that is ejected and falls from the battery cells included in the cell unit 200.

[0044] In addition, the battery pack 10 may further include a heat sink 320 disposed between the cell unit 200 of the battery assembly 100 and the bottom portion 310 of the accommodating room R1 to cool the battery cells included in the cell unit 200.

[0045] In this case, the heat sink 320 may have a guide hole 322 provided in a portion of the heat sink corresponding to the entrance of the pocket 310 a to guide the mass to the entrance of the pocket 310 a. Such a heat sink 320 may be made of a metal material having high thermal conductivity and heat resistance.

[0046] Depending on the embodiment, the heat sink 320 may be integrally formed with the bottom surface 310 of the receiving room R1.

[0047] Meanwhile, the case 300 may have an accommodating space R2 for accommodating various electrical components required for the operation of the battery pack 10.

[0048] In one embodiment, the battery pack 10 may further include a control module 330. The control module 330 may include a battery management system (BMS) that manages the charge / discharge operation, state of charge (SOC), state of health (SOH), etc. of the battery cells included in the battery assembly, and may be installed in the receiving space R2 of the case 300.

[0049] The battery pack 10 may further include a switching unit 340. The switching unit 340 may be configured to control an electrical connection between the battery pack 10 and an external circuit. To this end, the switching unit 340 may selectively include a current sensor, a power relay, a fuse, etc.

[0050] FIG. 2 shows an exploded view of the battery assembly 100 of the battery pack shown in FIG.

[0051] As shown in FIG. 2, a battery assembly 100 according to one embodiment of the present invention includes a plurality of cell units 200 and a support structure 110.

[0052] Each of the plurality of cell units 200 includes at least one battery cell and is configured to be stacked in the width direction (Y-axis direction). As will be described again later, each cell unit 200 may include at least one battery cell that serves as a basic unit for charging and discharging, and a cell cover that partially covers and supports the battery cell.

[0053] The support structure 110 is configured to support the plurality of cell units 200 and maintain a stacked state of the plurality of cell units 200. To this end, the support structure 110 may include sidewalls 112 and an integrated end cover 114. Such sidewalls 112 and integrated end covers 114 may be arranged along the lateral periphery of the plurality of cell units 200 stacked on top of each other.

[0054] In one embodiment, the support structure 110 may include a pair of sidewalls 112 and integrated end covers 114 .

[0055] In this case, the sidewalls 112 can be configured to support the multiple cell units 200, with one sidewall 112 positioned at each end of the multiple cell units 200, based on the width direction (Y-axis direction) or stacking direction of the multiple cell units 200.

[0056] That is, the first sidewall of the pair of sidewalls can be arranged adjacent to the first cell unit located at the outermost edge on one side of the plurality of cell units 200, and the second sidewall can be arranged adjacent to the second cell unit located at the outermost edge on the other side of the plurality of cell units 200.

[0057] The sidewalls 112, together with the integrated end cover 114 described below, tightly seal the plurality of cell units 200 together to form a single cell unit block that can be handled simultaneously. In this case, the sidewalls 112 can distribute pressure applied to the plurality of cell units 200 evenly across the entire cell unit 200.

[0058] Such a sidewall 112 may be made from a metal material such as aluminum or stainless steel, or may be made from a material in which metal and polymeric synthetic resin are combined using insert molding.

[0059] The integrated end cover 114 may be arranged at each end of the plurality of cell units 200 based on the longitudinal direction (X-axis direction) of the plurality of cell units 200. Furthermore, the integrated end cover 114 may be configured such that one end thereof is connected to the first sidewall and the other end thereof is connected to the second sidewall, and so as to collectively cover the openings of two or more cell covers among the cell covers of the plurality of cell units 200.

[0060] For this purpose, the sidewall 112 may include connecting portions 112a provided at both ends thereof and connected to one end or the other end of the integrated end cover 114. Correspondingly, the integrated end cover 114 may include a main body portion covering the openings of the plurality of cell units 200 and a corresponding connecting portion 114a extending from the main body portion and connected to the connecting portion 112a of the sidewall 112.

[0061] In one embodiment, the integrated end cover 114 may be provided with vent holes 114b for discharging gas generated in the battery cells of each cell unit at portions of the integrated end cover corresponding to the openings of the multiple cell units 200.

[0062] As shown in FIG. 2, the integrated end cover 114 may include a support portion 114c that extends from its main body toward the lower ends of the cell units 200 and supports the lower ends of the cell units 200.

[0063] Such an integrated end cover 114 may be made from a metal material such as aluminum or stainless steel, or may be made from a material that combines metal and polymeric synthetic resin using insert molding.

[0064] In this way, by applying an integrated end cover 114 that supports the cell unit and integrally covers the opening of the cell unit to the battery assembly 100, it is possible to eliminate the need for individual end covers to be applied to each cell unit, thereby simplifying the manufacturing process of the battery assembly.

[0065] FIG. 3 shows an enlarged view of the M1 region of FIG.

[0066] 3, the sidewalls 112 and the integrated end cover 114 included in the support structure 110 of the battery assembly 100 may be connected to each other to support a plurality of cell units 200. To this end, the connecting portion 112a of the sidewall 112 may have an insertion groove into which the corresponding connecting portion 114a of the integrated end cover 114 is inserted.

[0067] The corresponding connecting portion 114a of the integrated end cover 114 can be inserted into an insertion groove provided in the connecting portion 112a of the sidewall 112, and then fixed to the connecting portion 112a of the sidewall 112 by a fastening member S1 such as a screw or bolt.

[0068] Furthermore, the support portion 114c of the integrated end cover 114 may be configured to extend from the main body of the integrated end cover 114 toward the lower end side of the plurality of cell units 200 and support the lower ends of the plurality of cell units 200. In this case, the support portion 114c of the integrated end cover 114 may be configured to support the bus bar frame of each cell unit 200.

[0069] FIG. 4 shows a cell unit 200 of a battery assembly according to one embodiment of the present invention.

[0070] As shown in FIG. 4, the cell unit 200 may include a cell cover 210 that partially covers and supports at least one battery cell, holding it in an upright state.

[0071] The cell unit 200 may further include a bus bar assembly 220. The bus bar assembly 220 includes bus bars electrically connected to electrode leads of the battery cells inserted into the cell cover 210, and may be disposed at both ends of the cell cover 210 in the longitudinal direction (X-axis direction).

[0072] FIG. 5 shows an exploded view of the cell unit 200 shown in FIG.

[0073] As shown in FIG. 5 , the cell unit 200 may include at least one battery cell 202 and a cell cover 210 .

[0074] The battery cell 202 corresponds to the most basic rechargeable secondary battery, and may be manufactured by housing an electrode assembly and an electrolyte inside a case and sealing the case. The electrode assembly may be manufactured by sandwiching a separator between a positive electrode and a negative electrode.

[0075] The battery cell 202 may be a pouch-type secondary battery having a predetermined length and height, and electrode leads 202a electrically connected to the electrode assembly may be provided at both ends of the battery cell 202 in the longitudinal direction (X-axis direction).

[0076] The cell cover 210 may be configured to partially cover and support at least one battery cell 202 to hold it in an upright state. For example, as shown in Fig. 5, the cell cover 210 may be configured to partially cover and support three battery cells 202 stacked on top of each other to hold the battery cells in an upright state.

[0077] For this purpose, the cell cover 210 may be configured to cover at least one battery cell 202 inserted into the slot 214, and to have an opening 216 through which the electrode lead 202a of the at least one battery cell 202 inserted into the slot 214 is exposed to the outside of the cell cover 210.

[0078] When the cell unit 200 is placed in the storage room R1 of the case 300 described above, the cell cover 210 may be positioned so that the entrance of the slot 214 faces the bottom surface 310 of the storage room R1. In this case, the entrance of the pocket 310a provided in the bottom surface 310 may be provided at a position corresponding to the entrance of the slot 214.

[0079] Such a cell cover 210 may be formed in an "n" or "u" shape surrounding three sides of the at least one battery cell.

[0080] For example, the cell cover 210 may include a first cover portion 210a that forms one side wall of a slot 214 into which at least one battery cell is inserted, a second cover portion 210b that forms the other side wall of the slot 214, and a third cover portion 210c that connects the first cover portion 210a and the second cover portion 210b and forms the end portion of the slot 214.

[0081] That is, the first cover portion 210a may cover one side of the battery cell inserted into the slot 214. The second cover portion 210b may cover the other side of the inserted battery cell. Furthermore, the third cover portion 210c may cover the top end of the inserted battery cell.

[0082] In this case, an entrance to the slot 214 and an opening 216 through which the electrode lead 202a of at least one battery cell 202 inserted into the slot 214 is exposed may be provided between the first cover portion 210a and the second cover portion 210b.

[0083] The height L1 of the cell cover 210 (or the depth L1 of the slot 214) may be greater than the height L2 of the battery cell 202 in an upright state. As a result, the extra space created inside the slot 214 when the battery cell 202 is inserted can be used as a gas discharge passage.

[0084] Although Figure 5 shows a case where the number of battery cells 202 covered by one cell cover 210 is three, the number of battery cells covered by the cell cover 210 can be changed depending on the scale of the cell cover 210.

[0085] In one embodiment, the cell unit 200 may further include a bus bar assembly 220. The bus bar assembly 220 may include a bus bar 222 electrically connected to the electrode lead 202 a of the battery cell 202 inserted into the cell cover 210, and a bus bar frame 224 disposed in the opening 216 of the cell cover 210 to support the bus bar 222.

[0086] The bus bar assembly 220 may further include an insulating cover 226 disposed between the bus bar frame 224 and the integrated end cover 114 of the support structure 110 to prevent short circuits of the bus bars 222. The insulating cover 226 may be formed from a polymer resin having insulating properties.

[0087] In one embodiment, the cell cover 210 may further include a blocking portion 218 disposed at the entrance of the slot 214 to block removal of the battery cell inserted into the slot 214. The blocking portion 218 may be configured to protrude from the ends of the first cover portion 210a and the second cover portion 210b toward the entrance of the slot 214 and support the lower end of the battery cell inserted into the slot 214.

[0088] Furthermore, in one embodiment, the blocking portion 218 may have an insertion groove 218a into which a finger of a jig is inserted to contact the inner surface of the cell cover 210 and change the width of the slot 214, i.e., the spacing between the first cover portion 210a and the second cover portion 210b.

[0089] The cell cover 210 may be integrally formed, for example, by using a sheet metal processing process or an injection molding process.

[0090] The cell cover 210, which has a simplified structure, is formed from a metal material having higher rigidity than the battery cell case, and can protect the battery cell covered by the cell cover from external shocks and vibrations. For example, the cell cover 210 can be formed from a material including stainless steel (SUS), which is easy to process and has high corrosion resistance.

[0091] 4 and 5, the cell unit 200 may further include a clamp member configured to clamp the cell cover 210. In this case, the clamp member may be configured to clamp the cell cover 210 with at least one battery cell inserted therein, to prevent the slot 214 of the cell cover 210 from expanding or the battery cell 202 inserted in the slot 214 from being removed from the cell cover 210. Such a clamp member may be formed from tape or a strip of metal material.

[0092] FIG. 6 shows a cross-sectional view of the battery pack taken along line A1-A1' shown in FIG.

[0093] As shown in Figure 6, when the cell unit 200 is placed in the storage room R1 of the above-mentioned case 300, the cell cover 210 of the cell unit 200 can be positioned so that the entrance of its slot 214 faces the bottom portion 310 of the storage room R1.

[0094] Furthermore, the entrance of the pocket 310a provided in the bottom portion 310 may be provided at a position corresponding to the entrance of the slot 214. In this case, the entrance of the pocket 310a may be provided at a position corresponding to a portion of the entrance of the slot 214 of the cell cover 210 that is adjacent to the electrode lead 202a of the battery cell 202 inserted into the slot 214. This is because, when thermal runaway occurs in the battery cell 202, gas venting frequently occurs at the edge portion where the electrode lead 202a of the battery cell 202 is located.

[0095] Meanwhile, the heat sink 320 disposed between the cell unit 200 and the bottom surface part 310 may include guide holes 322 provided in a portion of the heat sink corresponding to the entrance of the pocket 310a of the bottom surface part 310 to guide the mass discharged from the battery cell 202 to the entrance of the pocket 310a. To this end, the guide holes 322 may be configured to gradually widen from the pocket 310a side toward the cell unit 200 side.

[0096] In one embodiment, the battery pack 10 may further include a thermal interface material (TIM) 350, which is a thermally conductive material interposed between the cell unit 200 and the heat sink 320. By using the TIM 350 to increase the thermal conductivity between the cell unit 200 and the heat sink 320, the cooling performance of the heat sink 320 can be further improved.

[0097] In one embodiment, the bottom portion 310 of the case 300 may include a gas passage 310b extending along the interior of the bottom portion 310. One end of the gas passage 310b may be connected to the pocket 310a, and the other end may be connected to the gas valve 316 of the case 300 described above.

[0098] In one embodiment, the bottom portion 310 may further include a barrier film 310c that blocks the entrance of the gas passage 310b connected to the pocket 310a. In this case, the barrier film 310c may be configured to burst when the surrounding pressure rises above a predetermined pressure, thereby opening the entrance of the gas passage 310b. To this end, the barrier film 310c may have various shapes of notches or grooves formed therein.

[0099] FIG. 7 shows the lower end portion of the cell unit 200 shown in FIG.

[0100] 7, the body of the battery cell 202 inserted into the cell cover 210 of the cell unit 200 and the bus bar frame 224 coupled to the end of the cell cover 210 are positioned with a certain gap between them, so that a vent area VA through which gas is discharged from the battery cell 202 may be provided at the lower end of the cell unit 200. An entrance of the above-described pocket 310a may be provided at a position corresponding to the vent area VA.

[0101] 8 and 9 show an assembly method for the cell unit 200 shown in FIG.

[0102] First, as shown in FIG. 8, when the fingers of the jig are inserted into the inside of the cell cover 210 to widen the gap between the first cover portion 210a and the second cover portion 210b of the cell cover 210, the battery cell 202 can be safely inserted between the first cover portion 210a and the second cover portion 210b.

[0103] The cutoff portion 218 of the cell cover 210 may have an appropriate length and shape so as not to damage the battery cell inserted as described above.

[0104] Next, as shown in FIG. 9, after at least one battery cell 202 is inserted into the cell cover 210, when the fingers of the jig are removed, the first cover portion 210a and the second cover portion 210b of the cell cover 210 return to their original positions due to their elastic force.

[0105] Then, the blocking portion 218 of the cell cover 210 supports the lower end of the battery cell 202 inserted between the first cover portion 210a and the second cover portion 210b, and can prevent removal of the battery cell 202. To this end, the blocking portion 218 can be bent from the ends of each of the first cover portion 210a and the second cover portion 210b toward the inside of the cell cover 210 to form a locking structure.

[0106] FIG. 10 shows a battery cell cover 210' according to an alternative embodiment.

[0107] As shown in FIG. 10, the blocking portion 218' of the battery cell cover 210' is bent from each end of the first cover portion 210a and the second cover portion 210b of the battery cell cover 210' toward the inside of the battery cell cover 210', but may also be bent toward the third cover portion 210c to form a locking structure.

[0108] FIG. 11 shows a battery cell cover 210'' according to another modified embodiment.

[0109] 11 , the cutoff portion 218″ of the battery cell cover 210″ may be bent from each end of the first cover portion 210a and the second cover portion 210b of the battery cell cover 210″ toward the third cover portion 210c, and then bent again to form a rounded curve on the opposite side of the third cover portion 210c. In this manner, the cutoff portion 218″ is configured to support the battery cell with its rounded surface, thereby preventing damage to soft battery cells such as pouch-type battery cells.

[0110] FIG. 12 shows a vehicle 2 according to one embodiment of the present invention.

[0111] As shown in FIG. 12, a vehicle 2 according to one embodiment of the present invention may include at least one battery pack 10 according to any one of the various embodiments described above.

[0112] In this way, the battery pack 10 installed in the vehicle 2 can provide the electrical energy required for various operations of the vehicle 2.

[0113] For reference, the battery pack according to the present invention can be applied to various electric devices and systems other than vehicles, as well as to an energy storage system (ESS).

[0114] As described above, according to the present invention, a pocket configured to capture mass that is ejected from a battery cell and falls under its own weight is provided on the bottom of the battery pack case, thereby facilitating the release of gas when thermal runaway occurs in the battery cell and preventing damage or explosion of the battery pack due to an increase in internal pressure of the battery pack.

[0115] In addition, instead of a plurality of battery cells being housed in a separate module case and then attached to the battery pack case, the battery cells are only partially covered by a cell cover with a simplified structure and then directly attached to the battery pack case, thereby reducing the weight and volume of the entire battery pack and increasing the energy density of the battery pack, while facilitating safe handling and attachment of the battery cells during battery pack manufacturing and reducing manufacturing costs.

[0116] Furthermore, a gas passage communicating with the pocket is provided at the bottom of the battery pack case, thereby diversifying the gas vent paths inside the battery pack and providing an alternative path when other gas vent paths are blocked.

[0117] Furthermore, gas that has traveled through a gas passage provided in the bottom portion of the battery pack case or another gas passage provided in the wall of the case is discharged in a predetermined direction by a gas valve, so that the gas vent direction of a battery pack mounted on the bottom of a vehicle can be set to the rear or side rather than above where the occupants are located, thereby ensuring the safety of the occupants.

[0118] Furthermore, the blocking portion of the cell cover supports the battery cell inserted in the slot of the cell cover and blocks the removal of the battery cell, thereby preventing the battery cell from being displaced or the cell cover from being detached to the outside, thereby ensuring the safety and reliability of the battery pack.

[0119] In addition, an insertion groove is provided in the blocking portion of the cell cover to facilitate the insertion of a tool that comes into contact with the inner surface of the cell cover to change the slot width of the cell cover, thereby facilitating the process of inserting the battery cell into the cell cover and preventing damage to the battery cell.

[0120] Furthermore, it goes without saying that the embodiments of the present invention can solve various technical problems other than those mentioned in this specification in the technical field in question as well as in related technical fields.

[0121] The present invention has been described above with reference to specific embodiments. However, it will be apparent to those skilled in the art that various modified embodiments can be realized within the technical scope of the present invention. Therefore, the embodiments disclosed above should be considered from an illustrative perspective, not a restrictive one. That is, the true technical scope of the present invention is defined by the appended claims, and all differences within the scope of equivalents thereto should be construed as being included in the present invention. [Explanation of symbols]

[0122] 2 vehicles 10 Battery Pack 100 Battery Assembly 110 Support structure 112 Sidewall 112a Connection part 114 Integrated End Cover 114a compatible connection part 114b Vent hole 114c Support part 200 cell units 202 battery cells 202a Electrode lead 210 Cell Cover 210' Battery Cell Cover 210'' Battery Cell Cover 210a first cover part 210b second cover part 210c Third cover part 214 Slots 216 Aperture 218 Breaker 218' Interceptor 218'' interrupter 218a Insertion groove 220 Busbar Assembly 222 Busbar 224 Busbar Frame 226 Insulating cover 300 cases 302 Lower case 304 Upper case 310 Bottom part 310a Pocket 310b Gas passage 310c Barrier membrane 312 Wall 314 Gas inlet 316 Gas Valve 320 Heatsink 322 Guide hole 330 Control Module 340 Switching Unit R1 Containment Room R2 Containment Space S1 Fastening member VA Vent Area

Claims

1. a cell unit including at least one battery cell; a case including a storage room having a bottom surface on which the cell unit is placed, the case storing the cell unit in the storage room; Including, the bottom surface portion includes a pocket configured to capture a mass that is ejected and falls from a battery cell included in the cell unit, The cell unit comprises: the battery cell assembly further includes a cell cover that covers the at least one battery cell inserted into the slot, the cell cover including a slot into which the at least one battery cell is inserted and an opening through which an electrode lead of the at least one battery cell inserted into the slot is exposed; the cell cover is arranged so that the entrance of the slot faces the bottom surface portion; The pocket has an entrance located at a position corresponding to the entrance of the slot, the opening of the pocket is provided at a position corresponding to a portion of the opening of the slot that is adjacent to an electrode lead of the at least one battery cell.

2. The cell unit comprises: a bus bar electrically connected to the electrode lead; a bus bar frame disposed in the opening of the cell cover and supporting the bus bar; 10. The battery pack of claim 1, further comprising:

3. the bottom portion further includes a gas passage extending along an interior of the bottom portion; The battery pack according to claim 1 , wherein the pocket is configured to be in communication with the gas passage.

4. the bottom portion further includes a blocking film blocking an inlet of the gas passage communicating with the pocket; The battery pack according to claim 3 , wherein the barrier membrane is configured to burst when the surrounding pressure rises above a predetermined pressure, thereby opening the entrance of the gas passage.

5. a heat sink disposed between the cell unit and the bottom surface portion to cool the battery cells included in the cell unit; The battery pack according to claim 1 , wherein the heat sink includes a guide hole provided in a portion of the heat sink corresponding to an entrance of the pocket, the guide hole guiding the mass to the entrance of the pocket.

6. The battery pack according to claim 5 , wherein the guide hole is configured to gradually widen from the pocket side toward the cell unit side.

7. The battery pack according to claim 5 , further comprising a thermally conductive material (TIM) interposed between the cell unit and the heat sink.

8. The cell unit includes a plurality of the cell units, The battery pack according to claim 1 , wherein the plurality of cell units are stacked on one another in one direction.

9. The battery pack according to claim 1 , wherein the at least one battery cell is comprised of a pouch-type secondary battery.

10. A vehicle comprising the battery pack according to any one of claims 1 to 9.

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