Patent Description:
The present disclosure relates to a battery pack and a vehicle including the same, and more specifically, to a battery pack with fire extinguishing function and a vehicle including the same.

As technology development and demand for mobile devices increase, 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 in which they have almost no memory effect compared to nickel-based secondary batteries, resulting in free charge/discharge, very low self-discharge rate, and high energy density, have been widely used.

Such a lithium secondary battery mainly uses a lithium-based oxide and a carbon material as a positive electrode active material and a negative electrode active material, respectively. The lithium secondary battery includes an electrode assembly in which a positive electrode plate and a negative electrode plate coated with the positive electrode active material and the negative electrode active material, respectively are disposed with a separator interposed therebetween, and a casing, that is, a battery case, for sealing and accommodating the electrode assembly along with an electrolyte.

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), and the like depending on which positive electrode and negative electrode active material to be used. In general, the electrodes of these lithium secondary batteries may be formed by coating a positive electrode or negative electrode active material on a current collector such as an aluminum or copper sheet, mesh, film, foil, or the like, followed by drying.

Recently, the supply of electric vehicles using secondary batteries has been spreading for eco-friendly purposes, and mandatory standards for thermal diffusion due to thermal runaway of secondary batteries have been published in countries such as China.

In this respect, the lithium secondary battery is currently in the spotlight due to its advantages such as high operating voltage and remarkably high energy density. However, the lithium secondary battery uses an organic electrolyte, so that when the lithium secondary battery is overcharged, overcurrent and overheating may occur, thereby causing a problem of a fire due to explosion or ignition in severe cases.

<CIT>, <CIT> and <CIT> each relate to battery modules having internal fire extinguishing means.

The present disclosure is designed to solve the problems of the related art, and therefore the present disclosure is directed to providing a battery pack capable of delaying propagation of flame or preventing thermal diffusion by extinguishing fire when a flame occurs in the battery pack, and a vehicle including the same.

In one aspect of the present disclosure, there is provided a battery pack according to claim <NUM>.

And, the fire extinguishing material may include Novec.

And, the stopper may include a first portion extending upwardly from an end of the lower plate; a second portion extending vertically from the first portion; and a third portion extending vertically from the second portion, wherein the third portion may be provided to be caught by the fixing portion.

Meanwhile, in another aspect of the present disclosure, there is provided a vehicle including the battery pack.

According to embodiments of the present disclosure, there is an effect of delaying propagation of flame or preventing thermal diffusion by extinguishing fire when a flame occurs in the battery pack, in virtue of the fire extinguishing material provided in the upper cover of the case to be allowed to fall in a flame.

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

As used herein, the term 'coupled' or 'connected' refers to not only a case in which one member and another member are directly coupled or directly connected, but also a case in which one member is indirectly coupled or indirectly connected to another member through a joint member.

<FIG> is an exploded perspective view schematically showing a battery pack according to the first embodiment of the present disclosure, and <FIG> is a cross-sectional view schematically showing an upper cover in a battery pack according to the first embodiment of the present disclosure.

Referring to <FIG> and <FIG>, a battery pack <NUM> according to an embodiment of the present disclosure includes a battery module <NUM>, a case <NUM>, and a fire extinguishing material <NUM>.

The battery module <NUM> includes a plurality of battery cells (not shown). The battery cell may be provided in various types, for example, in a cylindrical type, a prismatic type, or a pouch type. Hereinafter, for convenience of description, a case where the battery cell is in a pouch type will be mainly described.

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

In addition, the cartridge assembly accommodating the battery cell may be manufactured by injection molding of plastic. A connector element or a terminal element may be provided in the cartridge assembly. The connector element may 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 voltage or temperature of the battery cell.

In addition, the terminal element, as a main terminal connected to the battery cell, includes a positive electrode terminal and a negative electrode terminal, and a terminal bolt is provided in the terminal element to be electrically connected to the outside. Meanwhile, the battery cell may have a variety of shapes.

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 may be made of a conductive material.

The electrode lead may include a positive electrode lead and a negative electrode lead. The positive electrode lead and the negative electrode lead may be disposed in opposite directions with respect to the longitudinal direction of the battery cell, or the positive electrode lead and the negative electrode lead may be disposed in the same direction with respect to the longitudinal direction of the battery cell.

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

The electrode lead may be electrically coupled to a bus bar (not shown). The battery cell may have a structure in which a plurality of unit cells arranged in the order of positive electrode plate-separator-negative electrode plate or a plurality of bi-cells arranged in the order of positive electrode plate-separator-negative electrode plate-separator-positive electrode plate-separator-negative electrode plate are stacked according to the battery capacity.

The battery module <NUM> is accommodated in the case <NUM>. The case <NUM> may be provided in various ways. For example, referring to <FIG>, the case <NUM> may include a lower cover <NUM> into which the battery module <NUM> is inserted, and an upper cover <NUM> which is coupled to the lower cover <NUM> to close the battery module <NUM>.

The upper cover <NUM> includes a lower plate <NUM>, a deformation layer <NUM>, and an upper plate <NUM>.

Referring to <FIG>, the lower plate <NUM> is provided as a plate having various shapes, and at least one hole <NUM> is formed in the lower plate <NUM>. Then, when a flame is generated and the deformation layer <NUM> to be described later melts, the fire extinguishing material <NUM> falls through the hole <NUM> of the lower plate <NUM>.

The lower plate <NUM> may be made of various materials, for example, a metal material such as steel to maintain the shape of the hole <NUM> even in a flame. However, the material of the lower plate <NUM> is not limited thereto.

The deformation layer <NUM> is positioned on an upper side of the lower plate <NUM> and is provided to be deformed by flame. Deformation by flame may vary, for example, the shape may be deformed by melting by flame.

In addition, the deformation layer <NUM> is made of vinyl or plastic, which is a material that melts by flame. Hereinafter, for convenience of description, a case where the deformation layer <NUM> is vinyl will be mainly described.

When a flame starts in the battery module <NUM> inside the battery pack <NUM>, the flame melts the deformation layer <NUM> made of vinyl through the hole <NUM> of the lower plate <NUM>. Then, when a flame is generated and the deformation layer <NUM> is all melted, the hole <NUM> of the lower plate <NUM> blocked by the deformation layer <NUM> is completely opened, and thus the fire extinguishing material <NUM> located on the deformation layer <NUM> falls through the hole <NUM> of the lower plate <NUM> to remove the flame.

The upper plate <NUM> is coupled to the lower plate <NUM> to cover the fire extinguishing material <NUM>. That is, the fire extinguishing material <NUM> is disposed in a closed space between the upper plate <NUM> and the lower plate <NUM>. Here, since the deformation layer <NUM> made of vinyl is located on the upper side of the lower plate <NUM>, the fire extinguishing material <NUM> is disposed on the deformation layer <NUM> made of vinyl.

The fire extinguishing material <NUM> is provided in the upper cover <NUM> of the case <NUM>. For example, the fire extinguishing material <NUM> is disposed in a closed space between the upper plate <NUM> and the lower plate <NUM> of the upper cover <NUM>, and when a flame occurs in the battery cell or the battery module <NUM> inside the battery pack <NUM>, the fire extinguishing material <NUM> drops to the point where the flame occurs to remove the flame.

Here, the fire extinguishing material <NUM> includes a fire extinguishing liquid or fire extinguishing powder. That is, the fire extinguishing material <NUM> may be either liquid or powder as long as it is capable of extinguishing fire. For example, the fire extinguishing material <NUM> may be configured to include Novec. However, the fire extinguishing material <NUM> is not limited thereto, and various liquid or powder-type materials may be included as long as fire extinguishing function is possible.

Hereinafter, the operation and effect of the battery pack <NUM> according to the present disclosure will be described with reference to the drawings.

The case <NUM> of the battery pack <NUM> includes the upper cover <NUM>, wherein the upper cover <NUM> includes the lower plate <NUM>, the deformation layer <NUM>, and the upper plate <NUM>. The hole <NUM> is formed in the lower plate <NUM>. Also, the deformation layer <NUM> is made of vinyl or the like to be deformed by flame and is placed on the lower plate <NUM>, and the upper plate <NUM> is coupled to the lower plate <NUM> to form a closed space.

The fire extinguishing material <NUM> includes a fire extinguishing liquid or fire extinguishing powder, and is located on the deformation layer <NUM> in a closed space between the upper plate <NUM> and the lower plate <NUM>.

In addition, when a fire starts inside the battery pack <NUM> and flame is generated, the vinyl that is the deformation layer <NUM> is melted by the heat of the flame, thereby completely opening the hole <NUM> of the lower plate <NUM> blocked by the deformation layer <NUM>.

At this time, the fire extinguishing material <NUM> is dropped by gravity to the point where there is a flame through the hole <NUM> of the lower plate <NUM> to perform the function of fire extinguishing.

Accordingly, there is an effect of delaying propagation of flame or preventing thermal diffusion by extinguishing fire when a flame occurs in the battery pack <NUM>.

<FIG> is a cross-sectional view schematically showing the upper cover <NUM> in the battery pack <NUM> according to the invention of the present disclosure, and <FIG> is a perspective view schematically showing the deformation layer <NUM> in which the fixing portion <NUM> is formed in the battery pack <NUM> according to the invention of the present disclosure. Also, <FIG> is a perspective view schematically showing the lower plate <NUM> in which the stopper <NUM> is formed in the battery pack <NUM> according to the invention of the present disclosure.

Hereinafter, the operation and effect of the battery pack <NUM> according to the invention of the present disclosure will be described with reference to the drawings. However, descriptions common to those described in the battery pack <NUM> according to the present disclosure will be replaced with the above-mentioned descriptions.

Referring to <FIG>, the fixing portion <NUM> is formed in the deformation layer <NUM> and the stopper <NUM> is formed in the lower plate <NUM>.

If the size of the hole <NUM> formed in the lower plate <NUM> is small, the deformation layer <NUM> does not descend through the hole <NUM> of the lower plate <NUM> in spite of the fact that the deformation layer <NUM> made of vinyl is placed on the lower plate <NUM> and the fire extinguishing liquid or fire extinguishing powder is placed on the deformation layer <NUM>.

However, if the size of the hole <NUM> formed in the lower plate <NUM> is larger than that in a predetermined range, a portion of the deformation layer <NUM> descends to the hole <NUM> formed in the lower plate <NUM> due to the weight of the fire extinguishing liquid or fire extinguishing powder placed on the deformation layer <NUM>.

In order to prevent this, a structure capable of pulling the deformation layer <NUM> from both sides of the deformation layer <NUM> is required. To this end, in the invention, the fixing portion <NUM> is formed in the deformation layer <NUM>, and the stopper <NUM> is formed in the lower plate <NUM>.

Referring to <FIG>, the fixing portions <NUM> are formed at both ends of the deformation layer <NUM>. Here, the fixing portion <NUM> may be made of the same material as the deformation layer <NUM> or may be made of a different material. For example, when the deformation layer <NUM> is made of vinyl, the fixing portion <NUM> is made of plastic and may be fixedly coupled to the vinyl.

In addition, the fixing portion <NUM> is provided to have a thickness greater than that of the deformation layer <NUM> and is formed to protrude upwardly higher than the deformation layer <NUM>. That is, the thickness of the fixing portion <NUM> in the height direction is thicker than the thickness of the deformation layer <NUM> in the height direction.

Referring to <FIG> and <FIG>, the stopper <NUM> is formed in the lower plate <NUM>.

The stoppers <NUM> are formed at both ends of the lower plate <NUM> and are in contact with the fixing portion <NUM> as shown in <FIG>. That is, at least a portion of the stopper <NUM> is provided to be caught by the fixing portion <NUM>.

For example, the stopper <NUM> may be configured to include a first portion <NUM>, a second portion <NUM>, and a third portion <NUM>.

The first portion <NUM> extends upwardly from the end of the lower plate <NUM>. Also, the second portion <NUM> extends from the first portion <NUM> at a predetermined angle, for example, vertically. And, the third portion <NUM> extends from the second portion <NUM> at a predetermined angle, for example, vertically.

Here, referring to <FIG>, a predetermined space in which the third portion <NUM> side is opened by the first portion <NUM>, the second portion <NUM>, and the third portion <NUM> of the stopper <NUM> is formed, and referring to <FIG>, the fixing portions <NUM> formed at both ends of the deformation layer <NUM> are configured to be inserted into the space.

Accordingly, the third portion <NUM> is caught by the fixing portion <NUM>, and even if the fire extinguishing liquid or fire extinguishing powder is placed on the deformation layer <NUM>, a portion of the deformation layer <NUM> is prevented from descending into the hole <NUM> formed in the lower plate <NUM>.

Meanwhile, a vehicle (not shown) according to an embodiment of the present disclosure may include the above-described battery pack <NUM>. The battery pack <NUM> may be used in various machines or devices using electricity, and for example, may be disposed on an electric vehicle, particularly, an underfloor of an electric vehicle. Here, the electric vehicle may include not only an electric vehicle driven purely by electricity, but also a hybrid vehicle using other energy together with electric energy.

Claim 1:
A battery pack (<NUM>) comprising:
a battery module (<NUM>) comprising a plurality of battery cells;
a case (<NUM>) configured to accommodate the battery module (<NUM>) therein, and comprising an upper cover (<NUM>); and
a fire extinguishing material (<NUM>), comprising a fire extinguishing liquid or fire extinguishing powder, and provided in the upper cover (<NUM>) of the case (<NUM>) to fall when a flame occurs; wherein
the upper cover comprises (<NUM>) a lower plate (<NUM>) having at least one hole (<NUM>) formed therein; a deformation layer (<NUM>) positioned on an upper side of the lower plate (<NUM>) and deformed by flame; and an upper plate (<NUM>) coupled to the lower plate (<NUM>) to cover the fire extinguishing material (<NUM>), wherein the fire extinguishing material (<NUM>) is disposed on the deformation layer (<NUM>); wherein
the deformation layer (<NUM>) is made of vinyl or plastic, which is a material that melts in a flame in order to allow the fire extinguishing material (<NUM>) to fall through the hole (<NUM>) of the lower plate (<NUM>) when a flame occurs; wherein
fixing portions (<NUM>) are formed at both ends of the deformation layer (<NUM>), and stoppers (<NUM>) in contact with the fixing portions (<NUM>) are formed in the lower plate (<NUM>); wherein
the fixing portion (<NUM>) is formed to protrude upward by having a thickness greater than that of the deformation layer (<NUM>); and wherein
the stoppers (<NUM>) are formed at both ends of the lower plate (<NUM>) and are provided such that at least a portion of the stoppers (<NUM>) is caught by the fixing portion (<NUM>).