Battery module

Abstract

To provide a battery module with improved stability.SOLUTION: Disclosed is a battery module (100) including a cell array (30) including a plurality of battery cells (10) and a bus bar (20) configured to electrically connect the plurality of battery cells (10), a case (115) configured to accommodate the cell array (30), a cover (140) coupled to the case (115) to cover the cell array (30), and a fire extinguisher (170) disposed between the cell array (30) and the cover (140), wherein the fire extinguisher (170) includes a fire extinguishing sheet (160) configured to discharge a fire extinguishing material and a heat conductive layer (150) configured to diffuse heat to the entire fire extinguishing sheet (160).SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a battery module. [Background technology]

[0002] Unlike primary batteries, which cannot be recharged, secondary batteries are batteries that can be charged and discharged. Low-capacity secondary batteries are used in small portable electronic devices such as smartphones, feature phones, laptops, digital cameras, and camcorders, while large-capacity secondary batteries are widely used as motor drive power sources and power storage batteries in hybrid vehicles, electric vehicles, and the like. Such secondary batteries include an electrode assembly consisting of a positive electrode and a negative electrode, a case for accommodating the electrode assembly, and electrode terminals connected to the electrode assembly.

[0003] The above information disclosed in such background of the invention is intended only to enhance understanding of the background of the invention and may therefore include information that does not constitute prior art. Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention provides a battery module with improved stability.

[0005] However, the technical problems that the present invention aims to solve are not limited to the above-mentioned problems, and other problems not mentioned will be clearly understood by those skilled in the art from the description of the invention described below. [Means for solving the problem]

[0006] One embodiment of the present invention discloses a battery module including: a cell array including a plurality of battery cells and bus bars electrically connecting the plurality of battery cells; a case that houses the cell array; a cover part that engages with the case and covers the cell array; and a fire extinguishing part disposed between the cell array and the cover part, wherein the fire extinguishing part includes a fire extinguishing sheet that releases a fire extinguishing agent and a thermally conductive layer that diffuses heat throughout the fire extinguishing sheet.

[0007] In this embodiment, the fire-extinguishing sheet may be positioned to overlap the entire area of ​​the cell array.

[0008] In this embodiment, the plurality of battery cells may include vent holes on their respective upper surfaces, and the fire-extinguishing sheet may include openings that expose the vent holes.

[0009] In this embodiment, the cell array may further include wiring electrically connected to the bus bar, and the fire extinguishing sheet may be positioned to overlap the wiring.

[0010] In this embodiment, the plurality of battery cells may be arranged in a plurality of rows, and the wiring may be located between the plurality of rows.

[0011] In this embodiment, the lower surface of the fire extinguishing sheet may have the same shape as the upper surface of the cell array.

[0012] In this embodiment, the fire extinguishing sheet may be located between the cell array and the thermally conductive layer.

[0013] In this embodiment, the thermally conductive layer may be engaged with the cover portion.

[0014] In this embodiment, the heat conductive layer is located inside the fire extinguishing sheet, and the heat conductive layer may include at least one heat conductive wire.

[0015] In this embodiment, the fire extinguishing sheet may contain 40 wt % to 60 wt % of the fire extinguishing material.

[0016] Another embodiment of the present invention discloses a battery module including a plurality of battery cells, a case that houses the plurality of battery cells, a cover that engages with the case, and a fire-extinguishing unit that is arranged between the plurality of battery cells and the cover, wherein the fire-extinguishing unit includes a fire-extinguishing sheet that releases a fire-extinguishing substance and a heat-conductive layer that diffuses heat throughout the fire-extinguishing sheet, and the fire-extinguishing sheet contains 40% to 60% by weight of the fire-extinguishing substance.

[0017] In this embodiment, the fire-extinguishing sheet may be positioned to overlap the entire area of ​​the plurality of battery cells.

[0018] In this embodiment, the plurality of battery cells may include vent holes on their respective upper surfaces, and the fire-extinguishing sheet may include openings that expose the vent holes.

[0019] In this embodiment, the battery module may further include a bus bar electrically connecting the plurality of battery cells and a wiring electrically connected to the bus bar, and the fire-extinguishing sheet may be positioned to overlap the wiring.

[0020] In this embodiment, the plurality of battery cells may be arranged in a plurality of rows, and the wiring may be located between the plurality of rows.

[0021] In this embodiment, the plurality of battery cells and the bus bars form a cell array, and the lower surface of the fire-extinguishing sheet may have the same shape as the upper surface of the cell array.

[0022] In this embodiment, the fire-extinguishing sheet may be positioned between the plurality of battery cells and the thermally conductive layer.

[0023] In this embodiment, the thermally conductive layer may be engaged with the cover portion.

[0024] In this embodiment, the heat conductive layer is located inside the fire extinguishing sheet, and the heat conductive layer may include at least one heat conductive wire.

[0025] In this embodiment, the fire extinguishing sheet may include at least two fire extinguishing sheets spaced apart from each other, and the heat conductive layer may overlap the at least two fire extinguishing sheets. [Effects of the Invention]

[0026] According to an embodiment of the present invention, the battery module includes a fire-extinguishing sheet and a thermally conductive layer that diffuses heat throughout the fire-extinguishing sheet. Therefore, even if the battery module experiences localized thermal runaway, the entire fire-extinguishing sheet releases fire-extinguishing material, extinguishing the battery module at the initial stage of thermal runaway and preventing the thermal runaway from spreading throughout the battery module, thereby improving the stability of the battery module.

[0027] However, the effects obtained by the present invention are not limited to the effects described above, and other technical effects not mentioned will be clearly understood by those skilled in the art from the description of the invention described below. [Brief explanation of the drawings]

[0028] The following drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the detailed description of the invention described below, serve to further understand the technical concept of the present invention. Therefore, the present invention should not be interpreted as being limited to only the matters depicted in such drawings.

[0029] [Figure 1] FIG. 1 is an exploded perspective view schematically illustrating an example of a battery module according to an embodiment of the present invention. [Figure 2] FIG. 2 is a perspective view schematically illustrating an example of a battery cell of the battery module of FIG. [Figure 3] FIG. 3 is a cross-sectional view schematically showing an example of a cross section taken along the line III-III in FIG. [Figure 4] FIG. 4 is an exploded perspective view schematically illustrating another example of a battery module according to an embodiment of the present invention. [Figure 5] FIG. 5 is an exploded perspective view schematically illustrating another example of a battery module according to an embodiment of the present invention. [Figure 6] FIG. 6 is a perspective view schematically illustrating an example of part A in FIG. [Figure 7] FIG. 7 is an exploded perspective view schematically illustrating another example of a battery module according to an embodiment of the present invention. [Figure 8] FIG. 8 is an exploded perspective view schematically illustrating another example of a battery module according to an embodiment of the present invention. [Figure 9] FIG. 9 is an exploded perspective view schematically illustrating another example of a battery module according to an embodiment of the present invention. [Figure 10] FIG. 10 is a perspective view schematically illustrating an example of a cover including a thermally conductive layer of a battery module according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0030] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, the terms and words used in the specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted as meanings and concepts that are consistent with the technical idea of ​​the present invention, based on the principle that the inventor can appropriately define the concepts of terms to best describe the invention. Therefore, it should be understood that the embodiments described in this specification and the configurations shown in the drawings are merely some of the most preferred embodiments of the present invention and do not represent the entire technical idea of ​​the present invention, and therefore various equivalents and modified forms that can be substituted for them at the time of filing this application may exist.

[0031] Furthermore, as used herein, "comprise" and / or "comprising" specify the presence of stated shapes, numbers, steps, operations, members, elements, and / or groups thereof, but do not exclude the presence or addition of one or more other shapes, numbers, operations, members, elements, and / or groups.

[0032] Furthermore, to facilitate understanding of the present invention, the accompanying drawings may not be drawn to scale, and the dimensions of some components may be exaggerated, and the same reference numerals may be used to refer to the same components in different embodiments.

[0033] Although terms such as "first" and "second" are used to describe various components, it goes without saying that these components are not limited by these terms. These terms are used merely to distinguish one component from another, and it goes without saying that a first component can also be a second component unless otherwise specified.

[0034] Throughout the specification, unless specifically stated to the contrary, each element may be singular or plural.

[0035] When any structure is disposed "on (or under)" a component or "above (or below)" a component, it can mean that the structure is disposed in contact with the upper surface (or lower surface) of the component, but also that other structures may be interposed between the component and any structure disposed on (or below) the component.

[0036] Furthermore, when a component is described as being "coupled," "engaged," or "connected" to another component, it should be understood that the components may be directly coupled or connected to each other, or that different components may be "interposed" between the components, or that the components may be "coupled," "engaged," or "connected" through different components. Also, when a component is said to be electrically coupled to another component, this includes not only a direct connection, but also a connection via another element between them.

[0037] FIG. 1 is an exploded perspective view schematically illustrating an example of a battery module according to an embodiment of the present invention.

[0038] Referring to FIG. 1, a battery module 100 according to an embodiment of the present invention may include a cell array 30 including a plurality of battery cells 10 arranged in a plurality of rows side by side with each other, and bus bars 20 electrically connecting any one of the battery cells 10 to other adjacent battery cells 10.

[0039] The battery cell 10 may include a first terminal 11 and a second terminal 12 electrically connected via a bus bar 20 on one side thereof, and a vent hole 13 serving as a passage for discharging gas generated inside.

[0040] The first terminal 11 may be either a positive terminal or a negative terminal. When the first terminal 11 is a positive terminal, the second terminal 12 may be a negative terminal, and conversely, when the first terminal 11 is a negative terminal, the second terminal 12 may be a positive terminal. In other words, the first terminal 11 and the second terminal 12 are formed to have different electrical polarities and are not limited to a specific polarity.

[0041] The first terminal 11 of any battery cell 10 can be electrically connected to the second terminal 12 of another adjacent battery cell 10 via a bus bar 20, and the second terminal 12 of any battery cell 10 can be electrically connected to the first terminal 11 of another adjacent battery cell 10 via another bus bar 20. While FIG. 1 shows a series connection, it goes without saying that this is not limited to this structure and various connection structures can be adopted as needed. Furthermore, the number and arrangement of the battery cells 10 are not limited to the structure shown in FIG. 1 and can be changed as needed.

[0042] Meanwhile, the battery module 100 may include a case 115 that houses the cell array 30 and the fire extinguishing unit 170 on the cell array 30. The battery module 100 may further include a cover unit 140 that engages with the case 115 and covers the cell array 30 and the fire extinguishing unit 170.

[0043] The case 115 and the cover unit 140 can be engaged with each other using fastening members such as bolts, but the present invention is not limited to this and any fastening method is possible. That is, the case 115 and the cover unit 140 can be engaged with each other to form an internal space, and the cell array 30 and the fire extinguishing unit 170 can be housed in the internal space. Therefore, the materials of the case 115 and the cover unit 140 need to be materials that can protect the cell array 30 and the fire extinguishing unit 170 from mechanical shock or thermal shock.

[0044] The material of the case 115 and the cover portion 140 may include, but is not limited to, a durable and heat-resistant material such as ABS (Acrylonitrile Butadiene Styrene), PC (Polycarbonate), PP (Polypropylene), aluminum, or stainless steel.

[0045] Meanwhile, the fire extinguishing unit 170 located between the cell array 30 and the cover unit 140 may include a fire extinguishing sheet 160 that releases fire extinguishing material above a certain temperature, and a thermally conductive layer 150 that diffuses heat throughout the fire extinguishing sheet 160.

[0046] The fire extinguishing sheet 160 can be placed on the cell array 30. Furthermore, the fire extinguishing sheet 160 can be activated by high-temperature gas or flames emitted from the vent holes 13 when the temperature of the battery module 100 rises.

[0047] Specifically, the fire-extinguishing sheet 160 on the upper surface of the vent hole 13 can be melted by high-temperature gas or flames emitted from the vent hole 13. As a result, the fire extinguishing material stored inside the fire-extinguishing sheet 160 is released toward the battery module 100, thereby extinguishing the fire in the battery module 100.

[0048] In an optional embodiment, the fire extinguishing sheet 160 may include a weakened portion with a melting point lower than the surrounding area in the area overlapping the vent hole 13. If the fire extinguishing sheet 160 includes a weakened portion with a melting point lower than the surrounding area, the weakened portion may melt more easily when the temperature of any battery cell 10 rises and high-temperature gas or flame is released from the vent hole 13, thereby melting the fire extinguishing sheet 160 adjacent to the vent hole 13. Therefore, the fire extinguishing sheet 160 can preferentially release fire-extinguishing material around the weakened portion, efficiently suppressing thermal runaway of the battery module 100.

[0049] In another example, the fire-extinguishing sheet 160 may include an opening that exposes the vent hole 13. When the fire-extinguishing sheet 160 includes an opening, a discharge passage for high-temperature gas emitted from the vent hole 13 can be formed, and the high-temperature gas or flame emitted from the vent hole 13 can directly contact the thermally conductive layer 150 (described later), thereby diffusing the thermal energy generated in the battery module 100 throughout the fire-extinguishing sheet 160.

[0050] As a result, even if thermal runaway occurs locally in the battery module, the heat can be diffused throughout the fire-extinguishing sheet 160 via the thermally conductive layer 150. When the heat is diffused throughout the fire-extinguishing sheet 160, fire-extinguishing material is released from the entire fire-extinguishing sheet 160, and the battery module 100 is extinguished at the beginning of thermal runaway, thereby improving the stability of the battery module 100.

[0051] Meanwhile, various fire-extinguishing materials and fire-extinguishing methods may be used for the fire-extinguishing sheet 160. For example, the fire-extinguishing material contained in the fire-extinguishing sheet 160 may be a substance that cuts off oxygen in the battery module 100 to suffocate and extinguish the fire, such as a solid aerosol contained in a capsule form.

[0052] As another example, the fire-extinguishing material contained in the fire-extinguishing sheet 160 may include, but is not limited to, a substance that reduces the temperature of the battery module 100 to cool and extinguish the fire, such as NOVEC or cooling water.

[0053] The ratio of the total weight of the fire extinguishing material to the total weight of the fire extinguishing sheet 160 may be 40% to 60%. That is, the fire extinguishing sheet 160 may contain 40 wt% to 60 wt% of the fire extinguishing material. If the weight ratio of the fire extinguishing material is less than 40 wt%, the fire extinguishing effect on the battery module 100 may be insufficient, and if the weight ratio of the fire extinguishing material exceeds 60 wt%, it may be difficult to manufacture the fire extinguishing sheet 160 containing the fire extinguishing material.

[0054] In optional embodiments, the fire extinguishing sheet 160 may include more than one fire extinguishing material or may be formed in a multi-layer structure.

[0055] For example, the fire extinguishing sheet 160 may include fire extinguishing materials that are activated at different temperatures, or the fire extinguishing sheet 160 may include one layer adjacent to the cell array 30 and two layers above the first layer. In this case, the first layer adjacent to the cell array 30 may include a first fire extinguishing material with a relatively low activation temperature, and the second layer above the first layer may include a second fire extinguishing material with a higher activation temperature than the first fire extinguishing material.

[0056] If the fire extinguishing sheet 160 contains two or more types of fire extinguishing materials or is formed in a multi-layer structure, different fire extinguishing materials can be activated sequentially depending on the temperature and amount of gas discharged from the vent hole 13. In addition, such dual operation of the fire extinguishing sheet 160 allows for continuous discharge of fire extinguishing materials by sequentially activating according to the gas temperature and generation time.

[0057] Meanwhile, a thermally conductive layer 150 may be positioned between the fire-extinguishing sheet 160 and the cover part 140. If the temperature of any of the battery cells 10 rises, the upper part of the fire-extinguishing sheet 160 adjacent to that battery cell 10 may melt. In this case, if the thermally conductive layer 150 is disposed on top of the fire-extinguishing sheet 160, the thermally conductive layer 150 can diffuse the thermal energy generated in that battery cell 10 throughout the entire fire-extinguishing sheet 160.

[0058] For example, the fire extinguishing sheet 160 may include a plurality of fire extinguishing sheets 160 spaced apart from one another, and the heat conducting layer 150 may be arranged to overlap all of the plurality of fire extinguishing sheets 160 spaced apart from one another.

[0059] 1, the fire extinguishing sheet 160 may include a first fire extinguishing sheet 161 and a second fire extinguishing sheet 162. The thermally conductive layer 150 may be disposed so as to overlap both the first fire extinguishing sheet 161 and the second fire extinguishing sheet 162.

[0060] As a result, if thermal runaway occurs in any of the battery cells 10, the thermally conductive layer 150 can diffuse the thermal energy throughout the entire fire-extinguishing sheet 160. As a result, the entire fire-extinguishing sheet 160 releases the fire-extinguishing material to extinguish the battery module 100 at the initial stage of thermal runaway, thereby preventing the thermal runaway from spreading throughout the battery module 100 and improving the stability of the battery module 100.

[0061] If the thermally conductive layer 150 is omitted and the fire extinguishing agent is released only in the area of ​​the fire extinguishing sheet 160 that is located above any of the battery cells 10, the fire extinguishing efficiency for the battery module 100 may be reduced, and even if the fire extinguishing agent is released only in a portion of the fire extinguishing sheet 160, the entire fire extinguishing sheet 160 may have to be discarded, which may result in a waste of material.

[0062] Therefore, the thermally conductive layer 150 may include a material with excellent thermal conductivity, such as, but not limited to, copper, silver, gold, aluminum, or graphite.

[0063] Meanwhile, the shape of the thermally conductive layer 150 may vary. In an optional embodiment, the thermally conductive layer 150 may include a break that breaks due to a thermal shock or a mechanical shock in the area overlapping with the vent hole 13. If the thermally conductive layer 150 includes a break, when the temperature of any of the battery cells 10 rises and high-temperature gas is released through the vent hole 13, the break in the thermally conductive layer 150 can break to form an exhaust path for the high-temperature gas.

[0064] As another example, the thermally conductive layer 150 may include an opening hole corresponding to the vent hole 13 in the area overlapping the vent hole 13. When the thermally conductive layer 150 includes an opening hole, a discharge passage for high-temperature gas released from the vent hole 13 can be formed.

[0065] In addition, the cover portion 140 positioned on the thermally conductive layer 150 may also include gas exhaust passages corresponding to the gas exhaust passages that may be formed in the thermally conductive layer 150 .

[0066] Therefore, if the thermally conductive layer 150 includes a break or an opening hole and the cover part 140 also includes a gas exhaust passage, when high-temperature gas is released from the vent hole 13, the thermal energy contained in the high-temperature gas can be released to the outside of the battery module 100 through the high-temperature gas exhaust passage.

[0067] 2 is a perspective view schematically showing an example of a battery cell of the battery module of FIG. 1, and FIG. 3 is a cross-sectional view schematically showing an example of a cross section taken along line III-III of FIG.

[0068] Referring to Figures 2 and 3 together, the battery cell 10 according to this embodiment may include at least one electrode assembly 210 wound between a positive electrode 211 and a negative electrode 212 with a separator 213, which is an insulator, interposed therebetween, and a case 15 in which the electrode assembly 210 is housed.

[0069] The battery cell 10 according to the present embodiment will be described as a prismatic lithium-ion battery cell, but the present invention is not limited thereto and may be applied to various types of battery cells, such as a lithium polymer battery cell or a cylindrical battery cell.

[0070] The positive electrode 211 and the negative electrode 212 may include a coated portion, which is a region where an active material is applied to a current collector formed of a thin metal foil, and a plain portion 211a, 212a, which is a region where the active material is not coated.

[0071] The positive electrode 211 and the negative electrode 212 are wound up after sandwiching an insulating separator 213 therebetween. However, the present invention is not limited to this, and the electrode assembly 210 may have a structure in which positive electrodes and negative electrodes made of a plurality of sheets are alternately stacked with separators sandwiched between them.

[0072] The case 15 forms the overall appearance of the battery cell 10 and may be made of a conductive metal such as aluminum, an aluminum alloy, or nickel-plated steel. Furthermore, the case 15 may provide a space in which the electrode assembly 210 is housed.

[0073] The battery cell 10 may include a cap plate 17 that covers the opening of the case 15, and the case 15 and the cap plate 17 may be made of a conductive material. Here, the first terminal 11 and the second terminal 12 electrically connected to the positive electrode 211 or the negative electrode 212 may penetrate the cap plate 17 and protrude outward.

[0074] In addition, the outer circumferential surfaces of the upper pillars of the first terminal 11 and the second terminal 12 protruding outward from the cap plate 17 may be threaded and may be fixed to the cap plate 17 with nuts.

[0075] However, the present invention is not limited to this, and the first terminal 11 and the second terminal 12 may be formed with a rivet structure and riveted together, or may be welded to the cap plate 17 .

[0076] In addition, the cap plate 17 may be made of a thin plate and may be engaged with the opening of the case 15. The cap plate 17 may be formed with an electrolyte injection port 14 in which a sealing plug can be installed, and may be formed with a vent hole 13 with a notch.

[0077] The first terminal 11 and the second terminal 12 can be electrically connected to current collectors including first and second current collectors 240, 250 (hereinafter referred to as positive and negative current collectors) joined by welding to the positive electrode uncoated portion 211a or the negative electrode uncoated portion 212a.

[0078] For example, the first terminal 11 and the second terminal 12 may be joined by welding to the positive and negative electrode current collectors 240, 250. However, the present invention is not limited to this, and the first terminal 11 and the second terminal 12 may be integrally engaged with the positive and negative electrode current collectors 240, 250.

[0079] An insulating member may be provided between the electrode assembly 210 and the cap plate 17. Here, the insulating member may include first and second lower insulating members 260 and 270, and each of the first and second lower insulating members 260 and 270 may be provided between the electrode assembly 210 and the cap plate 17.

[0080] Furthermore, according to this embodiment, one end of a separating member that can be provided opposite one side surface of the electrode assembly 210 can be provided between the insulating member and the first terminal 11 and the second terminal 12 .

[0081] Here, the separating member may include first and second separating members 280 and 290 .

[0082] Therefore, one end of the first and second separating members 280 and 290 may be provided between the first and second lower insulating members 260 and 270 and the first terminal 11 and the second terminal 12, facing one side of the electrode assembly 210.

[0083] Finally, the first terminal 11 and the second terminal 12 welded to the positive and negative electrode current collectors 240, 250 can be engaged with one end of the first and second lower insulating members 260, 270 and the first and second separating members 280, 290.

[0084] FIG. 4 is an exploded perspective view schematically illustrating another example of a battery module according to an embodiment of the present invention.

[0085] 4, the battery module 400 may include a cell array 430 and a fire extinguishing unit 470 positioned on the cell array 430. The fire extinguishing unit 470 may include a fire extinguishing sheet 460 and a thermally conductive layer 450.

[0086] A fire extinguishing sheet 460 may be provided between the cell array 430 and a cover portion (not shown).

[0087] For example, the fire-extinguishing sheet 460 may be positioned so as to overlap the entire area of ​​the cell array 430. That is, the fire-extinguishing sheet 460 may be in a form that can cover the entire top of the cell array 430. For example, the fire-extinguishing sheet 460 may be in a rectangular form having an area corresponding to the entire area of ​​the cell array 430, but is not limited to this. Alternatively, the fire-extinguishing sheet 460 may be fabricated separately from the battery module 400 and then placed on the cell array 430.

[0088] When the fire-extinguishing sheet 460 covers the entire upper part of the cell array 430, if the temperature of the battery module 400 rises, a large amount of fire-extinguishing material is released onto the battery module 400, thereby efficiently controlling or preventing thermal runaway. Furthermore, since the fire-extinguishing sheet 460 covers the entire upper part of the cell array 430, even if the temperature of any battery cell rises and high-temperature gas or flames erupts, the fire-extinguishing material is released from the entire fire-extinguishing sheet 460, thereby extinguishing the fire in the battery module 400. In other words, when the fire-extinguishing sheet 460 covers the entire upper part of the cell array 430, fires in all of the battery cells 10 can be efficiently dealt with.

[0089] Meanwhile, the thermally conductive layer 450 may be positioned on the fire-extinguishing sheet 460. When the temperature of any battery cell 10 rises, the thermally conductive layer 450 can diffuse the heat throughout the fire-extinguishing sheet 460. As a result, the fire-extinguishing sheet 460 can release the extinguishing agent not only in a localized area where heat is generated but also from the entire fire-extinguishing sheet 460, thereby effectively extinguishing the fire in the battery module 400.

[0090] Since the thermally conductive layer 450 needs to diffuse heat throughout the fire-extinguishing sheet 460, the shape of the thermally conductive layer 450 may correspond to the shape of the fire-extinguishing sheet 460. Alternatively, the thermally conductive layer 450 may be fabricated separately from the battery module 400 and then disposed on the fire-extinguishing sheet 460.

[0091] FIG. 5 is an exploded perspective view schematically illustrating another example of a battery module according to an embodiment of the present invention, and FIG. 6 is a perspective view schematically illustrating an example of a portion A of FIG.

[0092] 5 and 6, the battery module 500 may include a cell array 530 and a fire extinguishing unit 570. The cell array 530 may further include wiring 535 electrically connected to the bus bar 520, and the fire extinguishing unit 570 may include a fire extinguishing sheet 560 and a thermally conductive layer 550.

[0093] The battery cells 510 are arranged in a plurality of rows, and the wiring 535 is positioned between the rows. The wiring 535 can be electrically connected to the bus bar 520 that electrically connects the battery cells 510.

[0094] As an example, the bus bar 520 may be provided with a terminal for measuring temperature and / or a terminal for measuring voltage, and the wiring 535 may be a wiring connected to the terminal for measuring temperature and / or the terminal for measuring voltage.

[0095] Meanwhile, heat generation in the battery module 500 can occur not only from the battery cells 510 but also from Joule heat in the wiring 535 or a short circuit in the wiring 535, and the heat generated in the wiring 535 can cause thermal runaway in the adjacent battery cells 510. Therefore, the fire-extinguishing sheet 560 is positioned in the area overlapping with the wiring 535, and when the temperature of the wiring 535 rises, the fire-extinguishing sheet 560 releases a fire-extinguishing agent onto the wiring 535 to lower the temperature of the wiring 535 or extinguish the fire, thereby preventing heat from being transferred to the entire battery module 500.

[0096] On the other hand, the wiring 535 can contain a material with excellent thermal conductivity. Therefore, if the fire-extinguishing sheet 560 is formed to extend in the same direction as the longitudinal direction of the wiring 535, heat conduction also occurs through the wiring 535, allowing the fire-extinguishing sheet 560 to operate as a whole.

[0097] Meanwhile, when the fire-extinguishing sheet 560 is placed on the cell array 530, it has the advantage of easily extinguishing a fire that occurs in the cell array 530, but it may cause defects such as pinching due to the protrusion of the wires 535. Furthermore, when the fire-extinguishing sheet 560 is placed on the cell array 530, foreign matter inside the battery cell 510 may damage the wires 535 in the event of thermal runaway, causing secondary thermal runaway. However, when the fire-extinguishing sheet 560 is placed in an area overlapping with the wires 535 and covers the wires 535, it is possible to prevent pinching of the wires 535 or secondary thermal runaway caused by foreign matter inside the battery cell 510 damaging the wires 535.

[0098] Therefore, in an optional embodiment, the battery module 500 may be provided with a dual fire-extinguishing sheet (not shown) positioned on the cell array 530 and a fire-extinguishing sheet 560 positioned overlapping the wiring 535.

[0099] Meanwhile, the thermally conductive layer 550 may be positioned on the fire-extinguishing sheet 560. The thermally conductive layer 550 may diffuse heat throughout the entire fire-extinguishing sheet 560. As a result, the fire-extinguishing sheet 560 may operate not only in a localized area where heat is generated, but also throughout the entire fire-extinguishing sheet 560, thereby effectively extinguishing the fire in the battery module 500.

[0100] Therefore, the thermally conductive layer 550 should be formed to cover the entire fire-extinguishing sheet 560. For example, the thermally conductive layer 550 may be formed to be larger than the area of ​​the fire-extinguishing sheet 560. For example, if the wiring 535 is formed in multiple rows, the fire-extinguishing sheets 560 may be positioned on the wiring 535, respectively. In this case, the thermally conductive layer 550 may be formed to cover all of the multiple fire-extinguishing sheets 560 that are spaced apart from one another. Such a thermally conductive layer 550 may be fabricated separately from the battery module 500 and then positioned on the fire-extinguishing sheet 560.

[0101] FIG. 7 is an exploded perspective view schematically illustrating another example of a battery module according to an embodiment of the present invention.

[0102] 7, the battery module 700 may include a cell array 730 and a fire extinguishing unit 770 on the cell array 730. The fire extinguishing unit 770 may include a fire extinguishing sheet 760 and a thermally conductive layer 750.

[0103] A fire extinguishing sheet 760 may be positioned on the cell array 730. Additionally, the fire extinguishing sheet 760 may include openings 765 that expose the vent holes 713 at the top of the battery cells 710.

[0104] When the fire-extinguishing sheet 760 includes the openings 765, an exhaust passage can be formed for the high-temperature gas emitted from the vent holes 713, and the high-temperature gas or flame emitted from the vent holes 713 can directly contact the thermally conductive layer 750, thereby diffusing the thermal energy generated in the battery module 700 throughout the fire-extinguishing sheet 760.

[0105] Meanwhile, the thermally conductive layer 750 may be positioned on the fire-extinguishing sheet 760. When the temperature of the battery module 700 rises, the thermally conductive layer 750 can diffuse the heat throughout the fire-extinguishing sheet 760. As a result, the fire-extinguishing sheet 760 can release extinguishing material not only in the localized area where heat is generated but also throughout the entire fire-extinguishing sheet 760, thereby effectively extinguishing the fire in the battery module 700.

[0106] Therefore, since the thermally conductive layer 750 needs to diffuse heat throughout the fire-extinguishing sheet 760, the shape of the thermally conductive layer 750 may correspond to the shape of the fire-extinguishing sheet 760. For example, the thermally conductive layer 750 may have opening holes 755 formed therein that correspond to the openings 765 of the fire-extinguishing sheet 760.

[0107] Furthermore, when the fire extinguishing sheet 760 and the heat conductive layer 750 include the openings 765 and the opening holes 755, a discharge passage for the high temperature gas released from the vent holes 713 can be formed.

[0108] FIG. 8 is an exploded perspective view schematically illustrating another example of a battery module according to an embodiment of the present invention.

[0109] 8, the battery module 800 may include a cell array 830 and a fire extinguishing unit 870 on the cell array 830. The fire extinguishing unit 870 may include a fire extinguishing sheet 860 and a thermally conductive layer 850.

[0110] In one embodiment of the present invention, the fire extinguishing sheet 860 may be a layer formed by applying a liquid fire extinguishing material onto the cell array 830 and then drying the material. In this manner, when the fire extinguishing sheet 860 is formed by applying a liquid fire extinguishing material onto the cell array 830 and then drying the material, the fire extinguishing sheet 860 may be formed in close contact with the upper surface of the cell array 830. Therefore, the lower surface of the fire extinguishing sheet 860 may have the same shape as the upper surface of the cell array 830. In other words, the fire extinguishing sheet 860 may include uneven portions corresponding to the unevenness of the cell array 830.

[0111] In addition, since the fire-extinguishing sheet 860 is in close contact with the upper surface of the cell array 830, when thermal runaway occurs in the battery module 800, it is possible to prevent fragments of the battery cell 810 or fragments of the cover (not shown) from entering the gap between the fire-extinguishing sheet 860 and the cell array 830 and causing a short circuit.

[0112] The thermally conductive layer 850 may be positioned on the fire-extinguishing sheet 860. When the temperature of the battery module 800 rises, the thermally conductive layer 850 can diffuse the heat throughout the fire-extinguishing sheet 860. As a result, the fire-extinguishing sheet 860 can release fire extinguishing material not only in the localized area where heat is generated but also throughout the entire fire-extinguishing sheet 860, thereby effectively extinguishing the fire in the battery module 800.

[0113] Meanwhile, although FIG. 8 shows an example in which the fire extinguishing sheet 860 corresponds to the total area of ​​the cell array 830, the present invention is not limited to this.

[0114] For example, the fire-extinguishing sheet 860 in Fig. 8 may have a shape that extends in one direction along the wiring 835 so as to overlap the wiring 835, according to the example shown and described in Fig. 5. In such a case, the fire-extinguishing sheet 860 that is in close contact with the wiring 835 can effectively prevent the wiring 835 located between the battery cells 810 from being pinched, and can prevent damage to the wiring 835 by foreign objects.

[0115] As another example, the fire extinguishing sheet 860 in FIG. 8 is formed by applying a liquid fire extinguishing material along the wiring 835 so as to overlap the wiring 835, and other areas of the cell array 830 may further include a sheet-like fire extinguishing sheet (such as 160 in FIG. 1) as shown and described in FIG. 1, etc.

[0116] FIG. 9 is an exploded perspective view schematically illustrating another example of a battery module according to an embodiment of the present invention.

[0117] 9, a battery module 900 may include a cell array 930 and a fire-extinguishing unit 970 on the cell array 930. The fire-extinguishing unit 970 may include a fire-extinguishing sheet 960 and a thermally conductive layer 950.

[0118] Referring to FIG. 9, a heat-conducting layer 950 can be disposed inside a fire-extinguishing sheet 960 .

[0119] By inserting the thermally conductive layer 950 inside the fire-extinguishing sheet 960, the integration degree of the battery module 900 can be increased.

[0120] For example, the thermally conductive layer 950 may include at least one thermally conductive wire 952 having an area smaller than that of the fire-extinguishing sheet 960. For example, the thermally conductive wire 952 may form a grid pattern. However, without being limited thereto, the thermally conductive wire 952 may have various patterns as long as the thermally conductive layer 950 is located inside the fire-extinguishing sheet 960 and the thermally conductive wire 952 can diffuse heat throughout the fire-extinguishing sheet 960.

[0121] The heat conducting wire 952 may include a material with good thermal conductivity, such as, but not limited to, copper, silver, gold, aluminum, or graphite.

[0122] Meanwhile, in FIG. 9, the fire-extinguishing sheet 960 is shown as including the vent hole 913 and an area corresponding to the periphery of the vent hole 913, and also including an opening 965 exposing the vent hole 913. However, it goes without saying that the heat-conductive layer 950 may be located inside the fire-extinguishing sheet (such as 160 in FIG. 1).

[0123] FIG. 10 is a perspective view schematically illustrating an example of a cover including a thermally conductive layer of a battery module according to an embodiment of the present invention.

[0124] Referring to FIG. 10, a cover 1040 covering the battery module may include a thermally conductive layer 1050.

[0125] For example, the thermally conductive layer 1050 may be fastened to the cover part 1040. When the thermally conductive layer 1050 is fastened to the cover part 1040, manufacturing of the battery module can be simplified.

[0126] In addition, if thermal runaway occurs in the battery module, strong vibrations may occur in the battery module, which may cause the fire extinguishing sheet (not shown) and the thermally conductive layer 1050 to shift positions.In such a case, the fire extinguishing sheet (not shown) in areas where the thermally conductive layer 1050 does not overlap may not be able to diffuse heat, and the fire extinguishing sheet (not shown) may not be able to release fire extinguishing material as a whole.

[0127] However, when the cover 1040 includes the thermally conductive layer 1050 and the thermally conductive layer 1050 is fixed to the cover 1040, the thermally conductive layer 1050 can be fixed in position without moving on the fire-extinguishing sheet (not shown) even if thermal runaway occurs in the battery module. As a result, even if thermal runaway occurs in the battery module and strong vibrations occur in the battery module, the positions of the thermally conductive layer 1050 and the fire-extinguishing sheet (not shown) do not shift, and the entire area of ​​the fire-extinguishing sheet (not shown) operates, thereby effectively extinguishing the fire in the battery module.

[0128] Although the present invention has been described above using limited embodiments and drawings, it goes without saying that the present invention is not limited thereto, and that various modifications and variations can be made by a person having ordinary skill in the art to which the present invention pertains within the technical spirit of the present invention and the equivalent scope of the claims set forth below.

Claims

1. a cell array including a plurality of battery cells and bus bars electrically connecting the plurality of battery cells; a case that accommodates the cell array; a cover portion that engages with the case to cover the cell array; a fire extinguishing unit disposed between the cell array and the cover unit, The fire extinguishing unit is a battery module including a fire extinguishing sheet that releases a fire extinguishing agent and a thermally conductive layer that diffuses heat throughout the fire extinguishing sheet.

2. The battery module according to claim 1 , wherein the fire-extinguishing sheet is positioned to overlap the entire area of ​​the cell array.

3. the plurality of battery cells each include a vent hole on an upper surface thereof; The battery module according to claim 1 , wherein the fire-extinguishing sheet includes an opening that exposes the vent hole.

4. the cell array further includes wiring electrically connected to the bus bar; The battery module according to claim 1 , wherein the fire-extinguishing sheet is positioned to overlap the wiring.

5. the plurality of battery cells are arranged in a plurality of rows, The battery module according to claim 4 , wherein the wiring is located between the plurality of rows.

6. The battery module according to claim 1 , wherein the lower surface of the fire-extinguishing sheet has the same shape as the upper surface of the cell array.

7. The battery module according to claim 1 , wherein the fire-extinguishing sheet is located between the cell array and the thermally conductive layer.

8. The battery module according to claim 1 , wherein the thermally conductive layer is engaged with the cover portion.

9. The heat conductive layer is located inside the fire extinguishing sheet, The battery module according to claim 1 , wherein the thermally conductive layer comprises at least one thermally conductive wire.

10. The battery module according to claim 1 , wherein the fire-extinguishing sheet contains 40 wt % to 60 wt % of the fire-extinguishing material.

11. a plurality of battery cells; a case that houses the plurality of battery cells; a cover portion that engages with the case; a fire extinguishing unit disposed between the plurality of battery cells and the cover unit, The fire extinguishing unit includes a fire extinguishing sheet that releases a fire extinguishing agent and a heat conductive layer that diffuses heat throughout the fire extinguishing sheet, The fire-extinguishing sheet contains 40 wt % to 60 wt % of the fire-extinguishing material.

12. The battery module according to claim 11 , wherein the fire-extinguishing sheet is positioned to overlap with an entire area of ​​the plurality of battery cells.

13. the plurality of battery cells each include a vent hole on an upper surface thereof; The battery module according to claim 11 , wherein the fire-extinguishing sheet includes an opening that exposes the vent hole.

14. the battery module further includes a bus bar electrically connecting the plurality of battery cells and a wiring electrically connected to the bus bar; The battery module according to claim 11 , wherein the fire-extinguishing sheet is positioned to overlap the wiring.

15. the plurality of battery cells are arranged in a plurality of rows, The battery module according to claim 14 , wherein the wiring is located between the plurality of rows.

16. the plurality of battery cells and the bus bar form a cell array; The battery module according to claim 14 , wherein the lower surface of the fire-extinguishing sheet has the same shape as the upper surface of the cell array.

17. The battery module according to claim 11 , wherein the fire-extinguishing sheet is located between the plurality of battery cells and the thermally conductive layer.

18. The battery module according to claim 11 , wherein the thermally conductive layer is engaged with the cover portion.

19. The heat conductive layer is located inside the fire extinguishing sheet, The battery module according to claim 11 , wherein the thermally conductive layer includes at least one thermally conductive wire.

20. The fire extinguishing sheet includes at least two fire extinguishing sheets spaced apart from each other, The battery module according to claim 11 , wherein the heat-conducting layer overlaps the at least two fire-extinguishing sheets.

Images