Battery pack with ignition delay structure

Abstract

A battery pack having an ignition delay structure according to the present invention includes one or more battery modules, a housing that accommodates the battery modules, a cooling unit that cools the battery modules while moving the battery modules, and an injection unit that injects the coolant onto the battery modules.

Description

[Technical Field]

[0001] The present invention relates to a battery pack, and more particularly to a battery pack having an ignition delay structure that utilizes a cooling water. [Background technology]

[0002] Unlike primary batteries, which cannot be recharged, secondary batteries are batteries that can be charged and discharged. They are used not only in portable devices but also in electric vehicles (EVs) and hybrid electric vehicles (HEVs), which are powered by electrical sources.

[0003] Currently widely used 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 unit secondary battery cells, i.e., unit battery cells, is approximately 2.5V to 4.6V. Therefore, if a higher output voltage is required, a battery pack is constructed by connecting multiple battery cells in series. Alternatively, a battery pack may be constructed by connecting multiple 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 can be variously set depending on the required output voltage or charge / discharge capacity.

[0004] When a battery pack is constructed by connecting a plurality of battery cells in series / parallel, a common method is to first construct a battery module including at least one battery cell, preferably a plurality of battery cells, and then use at least one such battery module to construct the battery pack by adding other components. Here, the battery module refers to a component in which a plurality of battery cells are connected in series or parallel, and the battery pack refers to a component in which a plurality of battery modules are connected in series or parallel to increase capacity, output, etc.

[0005] Typically, a battery pack 10 has a structure in which multiple battery modules 1 are housed in a pack housing 11, as shown in FIG. 1, and in order to maintain structural stability, multiple battery modules 1 or battery module assemblies are generally arranged on the same plane.

[0006] However, in the case of such a battery pack 10, if it is overcharged, the battery module 1 may swell, causing an explosion or fire, which may pose a greater risk to human life.

[0007] Therefore, there is a need to find a solution to provide a battery pack that can delay ignition and prevent chain fires when some battery modules 1 in the battery pack 10 ignite, as shown in FIG. 2. Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention provides a battery pack having an ignition delay structure that can slow down the heat transfer rate when some battery modules in the battery pack ignite, thereby preventing chain ignition of adjacent battery modules. [Means for solving the problem]

[0009] A battery pack having an ignition delay structure according to the present invention includes one or more battery modules, a housing that accommodates the battery modules, a cooling unit that cools the battery modules as coolant flows through the battery modules, and an injection unit that injects the coolant onto the battery modules.

[0010] In addition, the battery pack having an ignition delay structure according to the present invention further includes a coolant inlet for introducing the coolant into the battery pack, and a coolant outlet for discharging the coolant from the battery pack.

[0011] The cooling water inlet and the cooling water outlet are disposed in the housing.

[0012] In addition, the cooling water normally flows into the cooling section, and in the event of an ignition, the cooling water does not flow into the cooling section but flows into the injection section.

[0013] The cooling unit includes a cooling flow path through which the cooling water flows, and the injection unit includes an injection flow path through which the cooling water flows.

[0014] The battery pack having an ignition delay structure according to the present invention further includes a valve for selectively supplying the coolant flowing in from the coolant inlet to the cooling passage or the injection passage.

[0015] The cooling portion is disposed at the bottom of the housing.

[0016] The ejection portion is disposed on the upper surface of the housing.

[0017] The injection unit further includes an injection nozzle disposed in the injection passage for injecting the cooling water.

[0018] In addition, the battery pack having an ignition delay structure according to the present invention further includes a first valve for regulating the inflow of coolant into the cooling channel.

[0019] In addition, the battery pack having the ignition delay structure according to the present invention further includes a second valve for regulating the inflow of cooling water into the injection channel.

[0020] Furthermore, when the first valve is opened and the second valve is closed, the cooling water flows into the cooling flow path, and when the first valve is closed and the second valve is opened, the cooling water flows into the injection flow path.

[0021] In addition, the cooling water that flows in from the cooling water inlet flows into the cooling flow path by opening the first valve and closing the second valve, and the cooling water that flows in from the cooling water inlet flows into the injection flow path by closing the first valve and opening the second valve.

[0022] In addition, the battery pack having the ignition delay structure according to the present invention further includes a first coolant inlet passage that guides the coolant flowing in from the coolant inlet to the cooling flow path, and a second coolant inlet passage that guides the coolant flowing in from the coolant inlet to the injection flow path.

[0023] The first valve is disposed in the first cooling water inlet passage, and the second valve is disposed in the second cooling water inlet passage.

[0024] The second cooling water inlet passage is connected to the first cooling water inlet passage.

[0025] The second cooling water inlet passage is connected to the first cooling water inlet passage upstream of the first valve.

[0026] The cooling system further includes a first cooling water outlet passage that guides the cooling water from the cooling flow passage to a cooling water outlet, and a second cooling water outlet passage that guides the cooling water from the injection flow passage to the cooling water outlet.

[0027] The second coolant outlet passage is connected to the first coolant outlet passage. [Effects of the Invention]

[0028] The battery pack having the ignition delay structure according to the present invention has the effect of slowing down the heat transfer rate when some battery modules in the battery pack ignite, thereby preventing chain fires of adjacent battery modules. [Brief explanation of the drawings]

[0029] [Figure 1] FIG. 1 is a diagram showing a conventional battery pack. [Figure 2] 2 is a diagram showing a fire in a part of the battery module of FIG. 1. FIG. [Figure 3] 1 illustrates a battery pack having a fire delay structure according to the present invention. [Figure 4] 1 is a perspective view of a battery module according to the present invention; [Figure 5] 1 is an exploded perspective view of a battery module according to the present invention; [Figure 6] 1 is a perspective view of a battery cell according to the present invention; [Figure 7] 10A and 10B are diagrams illustrating the injection of cooling water in a battery pack having an ignition delay structure according to the present invention; [Figure 8] 10 is a diagram showing the cooling lines of the cooling section and the injection lines of the injection section as flow paths of cooling water according to the present invention. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0030] The advantages and features of the present invention and methods for achieving them will become more apparent from the following detailed description of the embodiments in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, and may be embodied in various different forms. These embodiments are provided solely to complete the disclosure of the present invention and to fully convey the scope of the invention to those skilled in the art. The present invention is defined only by the claims. Therefore, in some embodiments, well-known process steps, well-known device structures, and well-known techniques are not specifically described to avoid obscuring the present invention. The same reference numerals refer to the same elements throughout the specification.

[0031] In the drawings, thicknesses may be exaggerated to clearly show the various layers and regions. Similar parts are designated by the same reference numerals throughout the specification. When a layer, film, region, plate, or other part is said to be "on" another part, this includes not only the case where it is "directly on" the other part, but also the case where there are other parts between them. Conversely, when a part is said to be "directly on" another part, it means that there are no other parts between them. Furthermore, when a part is said to be "under" another part, this includes not only the case where it is "directly under" the other part, but also the case where there are other parts between them. Conversely, when a part is said to be "directly under" the other part, it means that there are no other parts between them.

[0032] The battery pack 2000 having an ignition delay structure according to the present invention will be described in detail with reference to the drawings.

[0033] Figure 3 is a diagram showing a battery pack having an ignition delay structure according to the present invention, Figure 4 is a perspective view of a battery module according to the present invention, Figure 5 is an exploded perspective view of a battery module according to the present invention, Figure 6 is a perspective view of a battery cell according to the present invention, Figure 7 is a diagram showing the injection of cooling water in a battery pack having an ignition delay structure according to the present invention, and Figure 8 is a diagram showing the cooling line of the cooling section and the injection line of the injection section as the flow path of cooling water according to the present invention.

[0034] The battery pack 2000 having an ignition delay structure according to an embodiment of the present invention may include one or more battery modules 1000 and a housing 2100 that accommodates the battery modules 1000 .

[0035] The housing 2100 can accommodate a plurality of battery modules 1000, and can include a bottom 2110, a side 2120, and a top cover 2130, as shown in FIGS.

[0036] The bottom 2110 of the housing 2100 may be in the form of a plate extending horizontally and may form the bottom of the housing 2100 .

[0037] The side portion 2120 of the housing 2100 forms the side of the housing 2100, and may include a left side portion 2121 that forms the left side of the housing 2100, a right side portion 2122 that forms the right side of the housing 2100, a front portion 2123 that forms the front surface of the housing 2100, and a rear portion 2124 that forms the rear surface of the housing 2100.

[0038] Therefore, the left side portion 2121 and the right side portion 2122 of the side portion 2120 can be disposed at the left and right ends of the bottom portion 2110, respectively, and the front portion 2123 and the rear portion 2124 can be disposed at the front and rear ends of the bottom portion 2110, respectively.

[0039] In this embodiment, the housing 2100 is shown in the form of a rectangular box, but is not limited thereto and may be configured in various shapes including a polygonal shape.

[0040] The top cover 2130 is disposed on the top of the housing 2100 and has a plate shape extending horizontally, and can cover the inside of the housing 2100. The top cover 2130 is connected to the upper end of the side part 2120, and more specifically, the edge of the top cover 2130 can be connected to the upper ends of the left side part 2121, the right side part 2122, the front part 2123, and the rear part 2124 that constitute the side part 2120 by bolts or the like.

[0041] Although not shown, partitions (not shown) may be disposed between the battery modules 1000 on the bottom 2110.

[0042] The battery module 1000 may include a battery cell stack 100 in which a plurality of battery cells 110 are stacked in one direction, a module case 200 that houses the battery cell stack 100, a bus bar frame 300 that is positioned on the front and / or rear surface of the battery cell stack 100, end plates 400 that cover the front and / or rear surface of the battery cell stack 100, and bus bars 310, 320 that are attached to the bus bar frame 300.

[0043] The battery cell stack 100 is formed by stacking a plurality of battery cells 110 in one direction, and the plurality of battery cells 110 may be electrically connected. The direction in which the plurality of battery cells 110 are stacked may be the Y-axis direction (or the −Y-axis direction) in FIG. 4.

[0044] The direction from the front surface to the rear surface of the battery cell stack 100 or the opposite direction may be defined as the length direction of the battery cell stack 100, which may be the X-axis direction in the drawing. Furthermore, the direction from the top surface to the bottom surface of the battery cell stack 100 or the opposite direction may be defined as the width direction of the battery cell stack 100, which may be the Z-axis direction in the drawing.

[0045] The longitudinal direction of the battery cell stack 100 may be substantially the same as the longitudinal direction of the battery cells 110. The electrode leads 111, 112 of the battery cells 110 are located on the front and rear surfaces of the battery cell stack 100, and the bus bars 310, 320 of the battery module 1000 may be disposed near the front and rear surfaces of the battery cell stack 100 to easily form electrical connections with the electrode leads 111, 112.

[0046] The battery cells 110 are provided as pouch-type battery cells, which can maximize the number of battery cells stacked per unit area. However, the battery cells 110 do not necessarily have to be provided as pouch-type cells, and may be provided as prismatic, cylindrical, or other various shapes.

[0047] The battery cell 110 provided in a pouch form can include an electrode assembly and a cell case 115 that houses the electrode assembly (see FIG. 6).

[0048] The cell case 115 of the battery cell 110 is for housing the electrode assembly and may be a pouch-type cell case 115. The cell case 115 may include a lower case and an upper case covering the lower case, and the upper and lower cases may be integrated. Alternatively, as shown in Fig. 4, the connecting portion between the upper and lower cases may be folded to form a folding structure. As shown, the upper case may completely cover the lower case, and a sealing portion 114 may be formed around the periphery.

[0049] Both the upper and lower cases may have a laminate structure including an inner coating layer, a metal layer, and an outer coating layer. The inner coating layer is located inside the cell case 115 relative to the metal layer and is in direct contact with the electrode assembly, so it must have insulating and electrolytic resistance. Furthermore, the sealing properties, i.e., the sealing portion where the inner layers are thermally bonded together, must have excellent thermal adhesive strength to seal against the outside. The metal layer is located between the inner and outer coating layers and serves as a barrier layer to prevent moisture and various gases from penetrating into the battery from the outside. A suitable material for the metal layer in contact with the inner coating layer is an aluminum (Al) thin film, which is lightweight yet highly formable. The outer coating layer is located outside the cell case 115 relative to the metal layer. This outer coating layer can be made of a heat-resistant polymer with excellent tensile strength, moisture barrier, and air barrier properties to protect the electrode assembly while ensuring heat resistance and fire resistance. For example, nylon or polyethylene terephthalate can be used.

[0050] The upper and lower cases each have a receiving groove 116 formed therein, and the electrode assembly can be received in the receiving groove 116 of the upper and lower cases.

[0051] The electrode assembly accommodated in the cell case 115 may be one selected from the group consisting of a jelly-roll type electrode assembly having a structure in which a separator is interposed between a long sheet-shaped negative electrode and a positive electrode and then wound up; a stack type electrode assembly consisting of unit cells having a structure in which rectangular positive and negative electrodes are stacked with a separator between them; a stack-folding type electrode assembly in which unit cells are wound up with a long separator film; and a lamination-stack type electrode assembly in which unit cells are stacked with a separator between them and attached to each other.

[0052] The electrode assembly may also include two electrode tabs and two electrode leads 111 and 112 connected to the electrode tabs via welding.

[0053] One of the two electrode leads 111, 112 may be a positive electrode lead connected to a positive electrode tab, and the other electrode lead 111, 112 may be a negative electrode lead connected to a negative electrode tab.

[0054] A lead film 113 may be attached to each of the electrode leads 111 and 112. The lead film 113 connected to the electrode leads 111 and 112 is located between the electrode leads 111 and 112 and the cell case 115, and prevents short circuits from occurring between the electrode leads 111 and 112 and the cell case 115, and improves sealing strength to prevent leakage of electrolyte.

[0055] Although the two electrode leads 111, 112 are shown as being located on opposite sides of the electrode assembly, they may be located on only one side of the electrode assembly depending on the placement of the electrode tabs.

[0056] The module case 200 is intended to protect the battery cell stack 100 and the electrical components connected thereto from external physical impacts, and the module case 200 can accommodate the battery cell stack 100 and the electrical components connected thereto in the internal space of the module case 200.

[0057] The module case 200 may have various structures. For example, the module case 200 may have a mono-frame structure. Here, the mono-frame may have the form of a metal plate with an integrated top, bottom, and both side surfaces. The mono-frame may be manufactured by extrusion molding. As another example, the module case 200 may have a structure in which a U-shaped frame and an upper plate (upper surface 201) are coupled together. In the case of a structure in which a U-shaped frame and an upper plate are coupled together, the module case 200 is formed by coupling the upper plate to the top of a U-shaped frame, which is a metal plate with an integrated or combined bottom and both side surfaces, and each frame or plate may be manufactured by press molding. In addition to the mono-frame or U-shaped frame, the module case 200 may also have an L-shaped frame structure, and may have various structures not described in the above examples.

[0058] The structure of the module case 200 may be provided in a form that is open in the longitudinal direction of the battery cell stack 100. The front and rear surfaces of the battery cell stack 100 may not be blocked by the module case 200. The electrode leads 111, 112 of the battery cells 110 may not be blocked by the module case 200. The front and rear surfaces of the battery cell stack 100 are blocked by a bus bar frame 300, an end plate 400, or bus bars 310, 320, which will be described later, and thereby the front and rear surfaces of the battery cell stack 100 can be protected from external physical impacts, etc.

[0059] A compression pad 150 may be positioned between the battery cell stack 100 and one side of the inner surface of the module case 200 .

[0060] The compression pad 150 may be disposed in the battery cell stack 100 so as to face the outermost battery cell 110 of the battery cell stack 100 in the X-axis direction on the drawing.

[0061] Furthermore, although not shown, a thermally conductive resin may be injected between the battery cell stack 100 and the inner surface of the module case 200, and the injected thermally conductive resin may form a thermally conductive resin layer (not shown) between the battery cell stack 100 and one side of the inner surface of the module case 200. Here, the thermally conductive resin layer may be located on the Z-axis of the battery cell stack 100, and the thermally conductive resin layer may be formed between the battery cell stack 100 and the bottom surface of the module case 200 located on the -Z-axis.

[0062] The bus bar frame 300 is positioned on one side of the battery cell stack 100 to cover that side and guide the connection between the battery cell stack 100 and an external device. Specifically, as shown, the bus bar frame 300 may be positioned on the front or rear side of the battery cell stack 100. At least one of bus bars 310, 320 and a module connector may be attached to the bus bar frame 300. As shown in FIG. 5 , one side of the bus bar frame 300 may be connected to the front or rear side of the battery cell stack 100, and the other side of the bus bar frame 300 may be connected to the bus bars 310, 320.

[0063] The bus bar frame 300 may include an electrically insulating material. The bus bar frame 300 may limit contact between the bus bars 310 and 320 and other parts of the battery cell 110 other than the parts connected to the electrode leads 111 and 112, thereby preventing an electrical short circuit from occurring.

[0064] The bus bar frames 300 may be located on the front and rear surfaces of the battery cell stack 100, respectively.

[0065] The bus bars 310, 320 may be attached to one surface of the bus bar frame 300 and may be used to electrically connect the battery cell stack 100 or the battery cells 110 to an external device circuit. The bus bars 310, 320 are located between the battery cell stack 100 or the bus bar frame 300 and the end plates 400, 450, thereby protecting them from external impacts and minimizing deterioration in durability due to external moisture.

[0066] The bus bars 310 , 320 can be electrically connected to the battery cell stack 100 via the electrode leads 111 , 112 of the battery cells 110 .

[0067] Specifically, the electrode leads 111, 112 of the battery cells 110 may pass through slits formed in the bus bar frame 300 and then bend to connect to the bus bars 310, 320. The bus bars 310, 320 may connect the battery cells 110 that make up the battery cell stack 100 in series or in parallel.

[0068] The bus bars 310, 320 may include a terminal bus bar 320 for electrically connecting one battery module 1000 to another battery module 1000. To be connected to another battery module 1000, at least a portion of the terminal bus bar 320 is exposed to the outside of the end plate 400, and the end plate 400 may have a terminal opening 410 for this purpose.

[0069] Unlike the other bus bars 310, the terminal bus bar 320 may further include a protruding portion that protrudes upward, and the protruding portion may be exposed to the outside of the battery module 1000 through the terminal opening 410. The terminal bus bar 320 may be connected to another battery module 1000 or a battery disconnect unit (BDU) through the protruding portion exposed through the terminal opening 410, thereby forming a high voltage (HV) connection therewith.

[0070] The end plate 400 may serve to protect the battery cell stack 100 and the electrical components connected thereto from external physical impact by sealing the open side of the module case 200. To this end, the end plate 400 may be made of a material having a predetermined strength, and may include, for example, a metal such as aluminum.

[0071] The end plate 400 may be coupled to the module case 200 while covering the bus bar frame 300 or the bus bars 310, 320 located on one side of the battery cell stack 100. Each corner of the end plate 400 may be coupled to a corresponding corner of the module case 200 by a method such as welding. In addition, an insulating cover 500 for electrical insulation may be located between the end plate 400 and the bus bar frame 300. The insulating cover 500 may include an electrically insulating material and may block contact between the bus bars 310, 320 and the end plate 400. The insulating cover 500 may be located on the inner surface of the end plate 400 and may be in close contact with the inner surface of the end plate 400, but this is not necessarily the case.

[0072] The end plates 400 may be located on the front and rear surfaces of the module case 200 so as to cover the front and rear surfaces of the battery cell stack 100, respectively.

[0073] The battery pack 2000 according to the present invention may further include a cooling water inlet 2200, a cooling water outlet 2300, a cooling unit 2400 for cooling the battery module 1000, and an injector 2500 for injecting cooling water onto the battery module 1000.

[0074] The coolant inlet 2200 allows coolant to flow from the outside into the battery pack 2000, and the coolant flows from the outside into the battery pack 2000 through the coolant inlet 2200. As shown in Fig. 3, the coolant inlet 2200 may be disposed on one side of the side part 2120 of the housing 2100, but may also be disposed on the top part 2130 or the bottom part 2110, for example.

[0075] The coolant outlet 2300 allows the coolant to flow out from the battery pack 2000 to the outside, and the coolant flows out from the battery pack 2000 to the outside through the coolant outlet 2300. As shown in Fig. 3, the coolant outlet 2300 may be disposed on one side of the side portion 2120 of the housing 2100, or on one side of the housing 2100 where the coolant inlet 2200 is disposed, but may also be disposed on the top portion 2130 or the bottom portion 2110.

[0076] The cooling unit 2400 may cool the battery modules 1000 accommodated inside the battery pack 2000, and may include a cooling flow path 2410 through which the cooling water flowing in from the cooling water inlet 2200 flows.

[0077] The cooling channel 2410 has a channel through which the coolant flows, and the coolant flows through the cooling channel 2410 to cool the battery module 1000. The cooling channel 2410 may have a zigzag shape as shown in Fig. 8, and may be configured in the form of a duct or a pipe.

[0078] The cooling unit 2400 including such a cooling channel 2410 may be disposed in the bottom 2110, as shown in Fig. 7. In the bottom 2110, the cooling unit 2400 may be disposed in the lower part of the bottom 2110, as shown in Fig. 7. As another example, the cooling unit 2400 may be disposed inside or on the upper part of the bottom 2110, or may be disposed in the side part 2120 or the top part 2130.

[0079] A first cooling water inlet passage 2210 may be disposed between the cooling water inlet 2200 and the cooling passage 2410, and a first valve 2220 may be disposed in the first cooling water inlet passage 2210.

[0080] The first valve 2220 can open and close the first cooling water inlet passage 2210 and adjust the inflow of cooling water into the cooling passage 2410 .

[0081] 8, a process in which coolant flows into the cooling unit 2400 according to the present invention will be described. The coolant flowing in through the coolant inlet 2200 flows into the cooling channel 2410 of the cooling unit 2400 through a first coolant inlet passage 2210 disposed between the coolant inlet 2200 and the cooling channel 2410 of the cooling unit 2400. The coolant flowing in the cooling channel 2410 cools the battery module 1000 while moving along the cooling channel 2410, and then the coolant flows through a first coolant outlet passage 2310 disposed between the coolant outlet 2300 and the cooling channel 2410, and is then discharged to the outside of the battery pack 2000 through the coolant outlet 2300.

[0082] The first cooling water inlet passage 2210, the cooling flow path 2410, and the first cooling water outlet passage 2310 may be connected to each other to form a single cooling water movement passage, and the first cooling water inlet passage 2210, the cooling flow path 2410, and the first cooling water outlet passage 2310 may be configured in the form of a duct or a pipe, etc.

[0083] The spraying unit 2500 may include a spraying passage 2510 through which the coolant flowing in from the coolant inlet 2200 flows, and may spray the coolant onto the battery module 1000 in the event of an ignition of the battery module 1000 or the like.

[0084] The injection flow path 2510 has a flow path through which the cooling water moves, and one or more injection holes or injection nozzles 2520 for injecting the cooling water may be disposed in the injection flow path 2510. Thus, the cooling water moves through the injection flow path 2510 and may be sprayed onto the battery modules 1000 through the injection holes or injection nozzles 2520. A plurality of injection holes or injection nozzles 2520 may be disposed at intervals along the injection flow path 2510 and disposed above each battery module 1000.

[0085] The ejection channel 2510 has a zigzag shape as shown in FIG. 8 and may be configured in the form of a duct or pipe.

[0086] The injection unit 2500 including such an injection channel 2510 may be disposed above the battery module 1000 inside the battery pack 2000, as shown in Fig. 7. The injection unit 2500 may be disposed apart from the upper surface unit 2130 and disposed below the upper surface unit 2130, as shown in Fig. 7. As another example, the injection unit 2500 may be disposed on the side surface unit 2120 or the bottom unit 2110.

[0087] A second cooling water inlet passage 2240 may be disposed between the cooling water inlet 2200 and the injection passage 2510, and a second valve 2230 may be disposed in the second cooling water inlet passage 2240. As shown in FIG. 8 , one end of the second cooling water inlet passage 2240 may be connected to the first cooling water inlet passage 2210, and the other end of the second cooling water inlet passage 2240 may be connected to the injection passage 2510.

[0088] The portion P of the first cooling water inlet passage 2210 to which the second cooling water inlet passage 2240 is connected may be a portion upstream of the first valve 2220.

[0089] The second valve 2230 can open and close the second cooling water inflow passage 2240 to adjust the inflow of cooling water into the injection passage 2510 .

[0090] 8, a process in which coolant flows into the injection unit 2500 according to the present invention will be described. The coolant flowing in through the coolant inlet 2200 flows into the injection passage 2510 of the injection unit 2500 through a second coolant inlet passage 2240 disposed between the coolant inlet 2200 and the injection passage 2510 of the injection unit 2500. The coolant flowing in the injection passage 2510 moves along the injection passage 2510, passes through a second coolant outlet passage 2320 disposed between the coolant outlet 2300 and the injection passage 2510, and is then discharged to the outside of the battery pack 2000 through the coolant outlet 2300. The second coolant outlet passage 2320 may be connected to the first coolant outlet passage 2310.

[0091] The second cooling water inlet passage 2240, the injection passage 2510, and the second cooling water outlet passage 2320 are connected to each other to form a single cooling water movement passage, and the second cooling water inlet passage 2240, the injection passage 2510, and the second cooling water outlet passage 2320 may be configured in the form of a duct or a pipe, etc.

[0092] In the present invention, when the second valve 2230 is normally closed and the first valve 2220 is normally open, the coolant flowing in through the coolant inlet 2200 flows through the first coolant inlet passage 2210 into the cooling flow path 2410, and as the coolant moves along the cooling flow path 2410, it cools the battery module 1000, and then flows out through the coolant outlet 2300 via the first coolant outlet passage 2310.

[0093] In the event of an event such as a fire, an abnormal rise in temperature or pressure, or heat detection, the first valve 2220 is switched from an open state to a closed state, and the second valve 2230 is switched from a closed state to an open state. In this manner, with the first valve 2220 closed and the second valve 2230 open, the coolant flows into the second coolant inlet passage 2240 and then flows into the injection passage 2510. As the coolant moves along the injection passage 2510, it is injected into the battery module 1000 through the injection hole or injection nozzle 2520, and the remaining coolant passes through the second coolant outlet passage 2320 and flows out through the coolant outlet 2300.

[0094] The battery pack 2000 according to the present invention has the ignition delay structure as described above, and normally coolant flows through the cooling flow path 2410 to cool the battery module 1000. In the event of an ignition or other such event, the coolant flows along the injection flow path 2510 and is directly injected onto the battery module 1000, thereby delaying the heat transfer phenomenon and preventing chain ignition.

[0095] In the above-described embodiment, the coolant flowing in through the coolant inlet 2200 flows into the cooling channel 2410 or the injection channel 2510 by opening and closing the first valve 2220 and the second valve 2230. However, in other embodiments, the coolant can flow into the cooling channel 2410 or the injection channel 2510 by using a single valve. In this case, a valve is disposed at a portion P of the first coolant inlet channel 2210 where the second coolant inlet channel 2240 is connected. A three-way valve can be used as this valve.

[0096] Meanwhile, the battery pack 2000 according to the present invention may further include a sensor, which may be a temperature sensor, a heat detection sensor, a pressure sensor, etc. Such a sensor may detect ignition, and upon detection of ignition, cooling water may be directly sprayed onto the battery module 1000, as described above.

[0097] In addition, in the present invention, it has been described that the cooling water flowing in through the cooling water inlet 2200 flows into the cooling section 2400 and the spraying section 2500 and moves there, but instead of the cooling water, a refrigerant can also flow in and move through the cooling section 2400 and the spraying section 2500 to perform the same function.

[0098] The battery pack according to the present invention may further include various control and protection systems such as a battery management system (BMS) and a cooling system.

[0099] The battery module 1000 and the battery pack 2000 according to the present invention can be applied to various devices, specifically, but not limited to, transportation means such as electric bicycles, electric cars, and hybrid cars, and ESS (Energy Storage Systems).

[0100] As described above, the present invention has been described based on preferred embodiments, but it is not limited to the above embodiments, and various changes and modifications may be made by a person having ordinary skill in the art to which the present invention pertains without departing from the spirit of the present invention. [Industrial Applicability]

[0101] The present invention provides a battery pack that can prevent chain fires of adjacent battery modules by slowing down the heat transfer rate when some battery modules in the battery pack catch fire. [Explanation of symbols]

[0102] 1 Battery Module 10 Battery Pack 11 Pack Housing 100 Battery cell stack 110 battery cells 111 Electrode lead 112 Electrode Lead 113 Lead Film 114 Sealing part 115 Cell Case 116 Storage groove 150 compression pads 200 Module Case 201 Top surface 300 Busbar Frame 310 Busbar 320 Busbar 320 Terminal Busbar 400 End Plate 410 Terminal opening 450 end plate 500 Insulation Cover 1000 Battery Module 2000 battery pack 2100 Housing 2110 Bottom 2120 Side part 2121 Left side part 2122 Right side part 2123 Front part 2124 Rear section 2130 Top part 2200 Cooling water inlet 2210 1st cooling water inflow passage 2220 First Valve 2230 Second Valve 2240 2nd cooling water inflow passage 2300 Cooling water outlet 2310 1st cooling water outflow passage 2320 2nd cooling water outflow passage 2400 Cooling section 2410 Cooling Channel 2500 injection part 2510 Injection channel 2520 Injection Nozzle

Claims

1. one or more battery modules; a housing that accommodates the battery module; a cooling unit that cools the battery module while cooling water flows; an injector for injecting the cooling water onto the battery module; A battery pack having a fire-retardant structure, comprising:

2. a cooling water inlet through which the cooling water flows into the battery pack; a cooling water outlet through which the cooling water flows out from the battery pack; 10. A battery pack having the ignition delay structure of claim 1, further comprising:

3. The battery pack with an ignition delay structure according to claim 2 , wherein the cooling water inlet and the cooling water outlet are respectively disposed on the housing.

4. Normally, the cooling water flows into the cooling section, 2. The battery pack having the ignition delay structure of claim 1, wherein the cooling water is configured to flow into the injection portion without flowing into the cooling portion during an event including a fire.

5. the cooling section includes a cooling flow path through which the cooling water flows, The battery pack having an ignition delay structure according to claim 1 , wherein the injection portion includes an injection flow path through which the cooling water flows.

6. The battery pack having an ignition delay structure according to claim 5 , further comprising a valve for selectively supplying the cooling water flowing in from a cooling water inlet to the cooling channel or the injection channel.

7. The battery pack having an ignition delay structure according to claim 5 , wherein the cooling portion is disposed at a bottom of the housing.

8. The battery pack with an ignition delay structure according to claim 5 , wherein the injection portion is disposed on an upper surface of the housing.

9. The battery pack with an ignition delay structure according to claim 5 , wherein the injection unit further comprises an injection nozzle disposed in the injection passage and injecting the cooling water.

10. The battery pack with an ignition delay structure according to claim 5 , further comprising a first valve for regulating the inflow of cooling water into the cooling channel.

11. The battery pack with an ignition delay structure according to claim 10 , further comprising a second valve for regulating the inflow of cooling water into the injection channel.

12. When the first valve is opened and the second valve is closed, the cooling water flows into the cooling flow path, The battery pack with an ignition delay structure according to claim 11 , wherein the first valve is closed and the second valve is opened, thereby allowing the coolant to flow into the injection passage.

13. The cooling water that flows in from a cooling water inlet flows into the cooling flow path by opening the first valve and closing the second valve, The battery pack with an ignition delay structure according to claim 12 , wherein the cooling water flowing in through the cooling water inlet flows into the injection passage by closing the first valve and opening the second valve.

14. a first cooling water inlet passage that guides the cooling water that has flowed in from the cooling water inlet into the cooling flow path; The battery pack with an ignition delay structure according to claim 5 , further comprising: a second coolant inlet passage that guides the coolant flowing in from the coolant inlet to the injection passage.

15. The battery pack with an ignition delay structure according to claim 14 , wherein the second coolant inlet passage is connected to the first coolant inlet passage.

16. a first valve for adjusting the inflow of cooling water into the cooling flow path; a second valve for adjusting the inflow of cooling water into the injection flow path, the first valve is disposed in the first cooling water inlet passage, The battery pack with an ignition delay structure according to claim 14 , wherein the second valve is disposed in the second coolant inlet passage.

17. The battery pack with an ignition delay structure according to claim 16 , wherein the second coolant inlet passage is connected to the first coolant inlet passage upstream of the first valve.

18. a first cooling water outlet passage that guides the cooling water from the cooling flow path to a cooling water outlet; The battery pack with an ignition delay structure according to claim 5 , further comprising: a second coolant outlet passage that guides the coolant from the injection passage to the coolant outlet.

19. The battery pack having an ignition delay structure according to claim 18 , wherein the second coolant outlet passage is connected to the first coolant outlet passage.

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