Battery pack and vehicle comprising the same

Abstract

Disclosed is a battery pack and a vehicle including the same. The battery pack according to one embodiment of the present application includes a battery module including a plurality of battery cells, a case accommodating the battery module and including an upper cover, and a fire extinguishing substance included in the upper cover of the case to fall down during a fire.

Description

TECHNICAL FIELD

[0001] This application claims priority to Korean Patent Application No. 10-2021-0002876, filed on January 8, 2021 in Korea, the disclosure of which is incorporated herein by reference.

[0002] The present disclosure relates to a battery pack and a vehicle including the same, and more particularly, to a battery pack having a fire extinguishing function and a vehicle including the same. BACKGROUND

[0003] As technology develops and the demand for mobile devices increases, the demand for secondary batteries as an energy source is rapidly increasing. In the related art, nickel-cadmium batteries or hydrogen ion batteries have been used as secondary batteries, but recently, lithium secondary batteries have been widely used, in which they have almost no memory effect compared to nickel-based secondary batteries, resulting in free charging / discharging, very low self-discharge rate, and high energy density.

[0004] Such a lithium secondary battery mainly uses lithium-based oxides and carbon materials as positive active materials and negative active materials, respectively. The lithium secondary battery includes an electrode assembly in which a positive electrode sheet and a negative electrode sheet coated with positive active materials and negative active materials, respectively, and a separator interposed between the positive electrode sheet and the negative electrode sheet are provided, and a case, i.e., a battery case, for sealing and accommodating the electrode assembly and an electrolyte.

[0005] The lithium secondary battery includes a positive electrode, a negative electrode, a separator interposed therebetween, and an electrolyte, and is classified into a lithium ion battery (LIB), a polymer lithium ion battery (PLIB), etc., depending on which positive active material and negative active material will be used. In general, the electrodes of these lithium secondary batteries can be formed by coating the positive active material or the negative active material on a current collector such as a sheet, a mesh, a film, or a foil of aluminum or copper, and then drying.

[0006] Recently, for the purpose of eco-friendliness, the supply of electric vehicles using secondary batteries has become widespread.

[0007] In this regard, lithium secondary batteries are currently in the spotlight due to their advantages such as high operating voltage and significantly high energy density. However, the lithium secondary battery uses an organic electrolyte, so that when the lithium secondary battery is overcharged, overcurrent and overheating can occur, thereby causing a fire problem due to explosion or ignition in a serious case. SUMMARY

[0008] TECHNICAL PROBLEM

[0009] The disclosure is designed to solve problems of the related art, and thus the disclosure aims to provide a battery pack capable of delaying the spread of a flame or preventing heat diffusion by extinguishing a flame when the flame occurs in the battery pack, and a vehicle including the same.

[0010] Technical Solution

[0011] In one aspect of the disclosure, a battery pack includes a battery module including a plurality of battery cells, a case configured to accommodate the battery module therein and including an upper cover, and a fire extinguishing substance disposed in the upper cover of the case to fall down when a flame occurs.

[0012] Further, the upper cover includes a lower plate in which at least one hole is formed, a deformation layer located on an upper side of the lower plate and deformed by a flame, and an upper plate coupled to the lower plate to cover the fire extinguishing substance, wherein the fire extinguishing substance can be disposed in the deformation layer.

[0013] Also, the deformation layer can be made of a vinyl material or plastic that is a material that melts in a flame so as to allow the fire extinguishing substance to fall down through the hole of the lower plate when the flame occurs.

[0014] In addition, the fire extinguishing substance can include a fire extinguishing liquid or a fire extinguishing powder.

[0015] Also, the fire extinguishing substance can include Novec.

[0016] Further, a fixing portion can be formed at both ends of the deformation layer, and a stopper in contact with the fixing portion can be formed in the upper plate or the lower plate.

[0017] Also, the fixing portion can be formed to protrude upward by having a greater thickness than the deformation layer.

[0018] Further, the stopper can be formed at both ends of the lower plate, and can be disposed such that at least a portion of the stopper is caught by the fixing portion.

[0019] Also, the stopper can include a first portion extending upward from an end of the lower plate, a second portion extending perpendicularly from the first portion, and a third portion extending perpendicularly from the second portion, wherein the third portion can be disposed to be caught by the fixing portion.

[0020] Meanwhile, in another aspect of the disclosure, a vehicle including the battery pack is provided.

[0021] Advantageous Effects

[0022] According to embodiments of the present disclosure, since the fire extinguishing substance provided in the upper cover of the case is allowed to fall into the flame, there is an effect of delaying the spread of the flame or preventing the heat spread by extinguishing the flame when the flame occurs in the battery pack. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is an exploded perspective view schematically illustrating a battery pack according to a first embodiment of the present disclosure.

[0024] Figure 2 is a cross-sectional view schematically illustrating an upper cover in a battery pack according to the first embodiment of the present disclosure.

[0025] Figure 3 is a cross-sectional view schematically illustrating an upper cover in a battery pack according to a second embodiment of the present disclosure.

[0026] Figure 4 is a perspective view schematically illustrating a deformation layer in which a fixing portion is formed in a battery pack according to the second embodiment of the present disclosure.

[0027] Figure 5 is a perspective view schematically illustrating a lower plate in which a stopper is formed in a battery pack according to the second embodiment of the present disclosure. DETAILED DESCRIPTION

[0028] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. It should be understood that the terms used in the specification and the appended claims should not be interpreted as limited to general and dictionary meanings, but interpreted based on the meanings and concepts corresponding to technical aspects of the present disclosure on the basis of the principle that the inventor is allowed to define appropriate terms in order to best explain the application. Therefore, the description proposed herein merely is a preferred example for the purpose of illustrations only and is not intended to limit the scope of the disclosure, and it should be understood that other equivalents and modifications could be made thereto without departing from the scope of the disclosure.

[0029] In the drawings, the size of each component or a specific portion constituting the component is exaggerated for the sake of convenience and clarity in description, omitted, or schematically illustrated. Therefore, the size of each component does not fully reflect the actual size. When it is determined that a detailed description of the relevant known function or configuration can unnecessarily obscure the gist of the present disclosure, such description will be omitted.

[0030] As used herein, the term 'coupled' or 'connected' means not only a direct coupling or direct connection between one member and another member, but also an indirect coupling or indirect connection between one member and another member through an intervening member.

[0031] Figure 1 is an exploded perspective view schematically illustrating a battery pack according to a first embodiment of the present disclosure, Figure 2is a cross-sectional view schematically illustrating an upper cover in a battery pack according to a first embodiment of the disclosure.

[0032] Referring to Figure 1 and Figure 2 A battery pack 10 according to an embodiment of the disclosure includes a battery module 100, a case 200, and a fire extinguishing substance 300.

[0033] The battery module 100 includes a plurality of battery cells (not shown). The battery cells can be provided as various types, such as a cylindrical type, a square type, or a pouch type. Hereinafter, a case in which the battery cells are mainly described as a pouch type will be described for convenience of description.

[0034] The plurality of battery cells can be stacked on each other in various forms. For example, the battery cells are accommodated in a cell assembly (not shown), and a plurality of cell assemblies can be stacked on each other. However, a stacking method of the plurality of battery cells is not limited thereto and can vary.

[0035] Further, the cell assembly accommodating the battery cells can be manufactured by injection molding of plastic. A connector element or a terminal element can be provided in the cell assembly. The connector element can include, for example, various types of electrical connection parts or connection members to be connected to a battery management system (BMS, not shown) capable of providing data on a voltage or a temperature of the battery cells.

[0036] Further, the terminal element connected to a main terminal of the battery cell includes a positive terminal and a negative terminal, and a terminal bolt is provided in the terminal element to be electrically connected to the outside. Meanwhile, the battery cell can have various shapes.

[0037] The battery cell includes an electrode lead (not shown), and the electrode lead provided in the battery cell is a kind of terminal exposed to the outside and connected to an external device, and can be made of an electrically conductive material.

[0038] The electrode lead can include a positive electrode lead and a negative electrode lead. The positive electrode lead and the negative electrode lead can be arranged in opposite directions with respect to a longitudinal direction of the battery cell, or the positive electrode lead and the negative electrode lead can be arranged in the same direction with respect to the longitudinal direction of the battery cell.

[0039] The positive electrode lead and the negative electrode lead can be made of various materials. For example, the positive electrode lead can be made of an aluminum material, and the negative electrode lead can be made of a copper material.

[0040] The electrode lead can be electrically coupled to a busbar (not shown). The battery cell can have a structure in which a plurality of unit cells arranged in the order of a positive plate-separator-negative plate or a plurality of double cells arranged in the order of a positive plate-separator-negative plate-separator-positive plate-separator-negative plate are stacked according to a battery capacity.

[0041] The battery module 100 is accommodated in the case 200. The case 200 can be provided in various ways. For example, referring to Figure 1 , the case 200 can include a lower cover 220 into which the battery module 100 is inserted, and an upper cover 210 coupled to the lower cover 220 to enclose the battery module 100.

[0042] The upper cover 210 includes a lower plate 211, a deformation layer 217, and an upper plate 219.

[0043] Referring to Figure 2 , the lower plate 211 is provided as a plate having various shapes, and at least one hole 212 is formed in the lower plate 211. Then, when a flame is generated and the deformation layer 217, which will be described later, is melted, the fire extinguishing substance 300 falls through the hole 212 of the lower plate 211.

[0044] The lower plate 211 can be made of various materials, for example, a metallic material such as steel, to maintain the shape of the hole 212 even in a flame. However, the material of the lower plate 211 is not limited thereto.

[0045] The deformation layer 217 is provided on the upper side of the lower plate 211, and is provided to be deformed by a flame. The deformation caused by the flame can vary, for example, the shape can be deformed by melting caused by the flame.

[0046] Further, the deformation layer 217 can be made of a vinyl or plastic, which is a material that is melted by a flame. Hereinafter, for convenience of description, a case in which the deformation layer 217 is a vinyl material will be mainly described.

[0047] When a flame starts in the battery module 100 within the battery pack 10, the flame melts the deformation layer 217 made of a vinyl material through the hole 212 of the lower plate 211. Then, when a flame is generated and the deformation layer 217 is completely melted, the hole 212 of the lower plate 211, which is blocked by the deformation layer 217, is completely opened, and thus the fire extinguishing substance 300 located on the deformation layer 217 falls through the hole 212 of the lower plate 211 to remove the flame.

[0048] The upper plate 219 is coupled to the lower plate 211 to cover the fire extinguishing substance 300. That is, the fire extinguishing substance 300 is provided in an enclosed space between the upper plate 219 and the lower plate 211. Here, since the deformation layer 217 made of a vinyl material is located on the upper side of the lower plate 211, the fire extinguishing substance 300 is provided on the deformation layer 217 made of a vinyl material.

[0049] The fire extinguishing substance 300 is disposed in the upper cover 210 of the case 200. For example, the fire extinguishing substance 300 is disposed in a closed space between the upper plate 219 and the lower plate 211 of the upper cover 210, and when a fire occurs in a battery cell or a battery module 100 within the battery pack 10, the fire extinguishing substance 300 falls to a point where the fire occurs to remove the fire.

[0050] Here, the fire extinguishing substance 300 can include a fire extinguishing liquid or a fire extinguishing powder. That is, as long as the fire extinguishing substance 300 can extinguish a fire, the fire extinguishing substance 300 can be a liquid or a powder. For example, the fire extinguishing substance 300 can be configured to include Novec. However, the fire extinguishing substance 300 is not limited thereto, and as long as a fire extinguishing function is possible, various liquid or powder type materials can be included.

[0051] Hereinafter, the operation and effects of the battery pack 10 according to the first embodiment of the disclosure will be described with reference to the accompanying drawings.

[0052] The case 200 of the battery pack 10 includes the upper cover 210, in which the upper cover 210 includes the lower plate 211, the deformation layer 217, and the upper plate 219. The hole 212 is formed in the lower plate 211. Also, the deformation layer 217 is made of a vinyl material or the like to be deformed by a flame, and is disposed on the lower plate 211, and the upper plate 219 is coupled to the lower plate 211 to form a closed space.

[0053] The fire extinguishing substance 300 includes a fire extinguishing liquid or a fire extinguishing powder, and is located on the deformation layer 217 in the closed space between the upper plate 219 and the lower plate 211.

[0054] Further, when a fire occurs inside the battery pack 10 and a flame is generated, the vinyl material as the deformation layer 217 is melted by the heat of the flame, thereby completely opening the hole 212 of the lower plate 211 blocked by the deformation layer 217.

[0055] At this time, the fire extinguishing substance 300 falls to a point where the flame exists via the hole 212 of the lower plate 211 by gravity to perform a fire extinguishing function.

[0056] Accordingly, there is an effect of delaying the spread of a flame or preventing the spread of heat by extinguishing the flame when a flame occurs in the battery pack 10.

[0057] Figure 3 FIG. 2 is a cross-sectional view schematically showing the upper cover 210 in the battery pack 10 according to the second embodiment of the disclosure, and Figure 4 FIG. 3 is a perspective view schematically showing the deformation layer 217 in which the fixing portion 218 is formed in the battery pack 10 according to the second embodiment of the disclosure. Also, Figure 5 FIG. 4 is a perspective view schematically showing the lower plate 211 in which the stopper 213 is formed in the battery pack 10 according to the second embodiment of the disclosure.

[0058] Hereinafter, the operation and effects of the battery pack 10 according to the second embodiment of the present disclosure will be described with reference to the drawings. However, the same descriptions as those described in the battery pack 10 according to the first embodiment of the present disclosure will be replaced by the above-described descriptions.

[0059] Referring to Figures 3 to 5 , the second embodiment differs from the first embodiment in that the fixing portions 218 are formed in the deformation layer 217 and the stoppers 213 are formed in the lower plate 211.

[0060] If the size of the hole 212 formed in the lower plate 211 is small, even though the deformation layer 217 made of a vinyl material is disposed on the lower plate 211 and the fire extinguishing liquid or powder is placed on the deformation layer 217, the deformation layer 217 does not descend through the hole 212 of the lower plate 211.

[0061] However, if the size of the hole 212 formed in the lower plate 211 is greater than the size within a predetermined range, a portion of the deformation layer 217 descends into the hole 212 formed in the lower plate 211 due to the weight of the fire extinguishing liquid or powder placed on the deformation layer 217.

[0062] In order to prevent this, a structure capable of holding the deformation layer 217 from both sides of the deformation layer 217 is required. To this end, in the second embodiment, the fixing portions 218 are formed in the deformation layer 217 and the stoppers 213 are formed in the lower plate 211.

[0063] Referring to Figure 3 and Figure 4 , the fixing portions 218 are formed at both ends of the deformation layer 217. Here, the fixing portions 218 can be made of the same material as the deformation layer 217, or can be made of a different material. For example, when the deformation layer 217 is made of a vinyl material, the fixing portions 218 are made of plastic and can be fixedly coupled to the vinyl material.

[0064] Further, the fixing portions 218 are provided to have a thickness greater than that of the deformation layer 217 and are formed to protrude upward higher than the deformation layer 217. That is, the thickness of the fixing portions 218 in the height direction is thicker than the thickness of the deformation layer 217 in the height direction.

[0065] Referring to Figure 3 and Figure 5 , the stoppers 213 are formed in the lower plate 211. Here, the stoppers 213 can be formed in the upper plate 219 or the lower plate 211, but hereinafter, for convenience of description, a case in which the stoppers 213 are formed in the lower plate 211 will be mainly described.

[0066] The stoppers 213 are formed at both ends of the lower plate 211 and are in contact with the fixing portions 218, as inFigure 3 That is, at least a portion of the stopper 213 is disposed to be caught by the fixing portion 218.

[0067] For example, the stopper 213 can be configured to include a first portion 214, a second portion 215, and a third portion 216.

[0068] The first portion 214 extends upward from an end of the lower plate 211. Also, the second portion 215 extends from the first portion 214 at a predetermined angle (e.g., perpendicularly). Also, the third portion 216 extends from the second portion 215 at a predetermined angle (e.g., perpendicularly).

[0069] Here, referring to Figure 5 , a predetermined space in which the third portion 216 side is opened is formed by the first portion 214, the second portion 215, and the third portion 216 of the stopper 213, and referring to Figure 3 , the fixing portion 218 formed at both ends of the deformation layer 217 is configured to be inserted into the space.

[0070] Accordingly, the third portion 216 is caught by the fixing portion 218, and even if the fire extinguishing liquid or the fire extinguishing powder is placed on the deformation layer 217, a portion of the deformation layer 217 is prevented from descending into the hole 212 formed in the lower plate 211.

[0071] Meanwhile, a vehicle (not shown) according to an embodiment of the disclosure can include the battery pack 10 described above. The battery pack 10 can be used in various machines or devices using electric power, and for example, can be disposed on an electric vehicle, particularly, under a floor of the electric vehicle. Here, the electric vehicle can include not only a pure electric power-driven electric vehicle, but also a hybrid vehicle using other energy together with electric energy.

[0072] The present application has been described in detail. However, it should be understood that although a preferred embodiment of the disclosure is indicated, the detailed description and specific examples are given by way of illustration only, since various changes and modifications within the scope of the disclosure will become apparent to those skilled in the art from this detailed description.

[0073] Industrial Applicability

[0074] The disclosure relates to a battery pack and a vehicle including the same, and particularly, can be used in an industry related to a secondary battery.

Claims

1.A battery pack comprising: a battery module including a plurality of battery cells; a case configured to accommodate the battery module therein, and including an upper cover; and a fire extinguishing substance disposed in the upper cover of the case to fall upon occurrence of a flame, wherein the upper cover includes: a lower plate in which at least one hole is formed; a deformation layer located on an upper side of the lower plate and deformed by a flame; and an upper plate coupled to the lower plate to cover the fire extinguishing substance, wherein the fire extinguishing substance is disposed on the deformation layer, wherein a fixing portion is formed at both ends of the deformation layer, and wherein a stopper in contact with the fixing portion is formed in the upper plate or the lower plate. 2.The battery pack according to claim 1, wherein the deformation layer is made of a plastic as a material that melts in a flame, so as to allow the fire extinguishing substance to fall through the hole of the lower plate upon occurrence of a flame. 3.The battery pack according to claim 1, wherein the deformation layer is made of a vinyl material as a material that melts in a flame, so as to allow the fire extinguishing substance to fall through the hole of the lower plate upon occurrence of a flame. 4.The battery pack according to claim 1, wherein the fire extinguishing substance includes a fire extinguishing liquid or a fire extinguishing powder. 5.The battery pack according to claim 1, wherein the fire extinguishing substance includes Novec. 6.The battery pack according to claim 1, wherein the fixing portion is formed to protrude upward by having a thickness greater than that of the deformation layer. 7.The battery pack according to claim 6, wherein, the stopper is formed at both ends of the lower plate, and is disposed such that at least a portion of the stopper is caught by the fixing portion. 8.The battery pack according to claim 7, wherein the stopper includes a first portion extending upward from an end of the lower plate, a second portion extending perpendicularly from the first portion, and a third portion extending perpendicularly from the second portion, wherein the third portion is disposed to be caught by the fixing portion. 9.A vehicle including the battery pack according to any one of claims 1 to 8.

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