Heat absorber and battery module including same

Abstract

According to an aspect of the present invention, a heat sink can absorb heat generated from a battery cell. The heat sink may include an absorbent material that absorbs a cooling liquid, and an exterior material in which the absorbent material is housed while absorbing the cooling liquid.

Description

[Technical field]

[0001] [CROSS REFERENCE TO RELATED APPLICATIONS] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0034316 filed on March 18, 2022 and Korean Patent Application No. 10-2023-0035225 filed on March 17, 2023, and all contents disclosed in the documents of said Korean patent applications are incorporated herein by reference.

[0002] The present invention relates to a heat sink that absorbs heat generated from a battery cell and a battery module including the same. [Background technology]

[0003] Secondary batteries, which can be charged and discharged, are suitable for use as built-in battery cells since they do not require replacement of battery cells, and the stability and capacity of secondary batteries are rapidly improving, so they are being applied to a variety of devices.

[0004] For example, secondary batteries are not only widely used as energy sources for wireless mobile devices, which are small multi-functional products, or wearable devices worn on the body, but are also used as energy sources or energy storage systems (ESS) for electric vehicles and hybrid electric vehicles, which are presented as alternatives to existing gasoline and diesel vehicles that cause air pollution.

[0005] In particular, in order to use a secondary battery as a large-capacity, high-output energy source, a battery module including a plurality of battery cells and a battery pack including a plurality of the battery modules are used. As such, as secondary batteries are used as large-capacity, high-output energy sources, the issue of ensuring the safety of the secondary batteries has become an important concern.

[0006] Conventionally, in order to prevent the lifespan of a secondary battery from being rapidly shortened due to temperature during long-term use, a cooling system has been designed based on the amount of heat generated by the secondary battery's operating environment and a reliable operating temperature. However, when one battery cell included in a battery module or battery pack exceeds a critical temperature due to abnormal heat generation, thermal runaway and propagation may occur due to the surrounding battery cells, which may cause safety issues.

[0007] In order to prevent such safety problems, a method of disposing a heat insulating material between a plurality of battery cells or a plurality of battery modules has been used in the past. However, in order to sufficiently delay the heat propagation, the thickness of the heat insulating material must be very thick, which causes a problem that the energy density of the secondary battery is reduced due to the volume of the heat insulating material. In addition, since the heat insulating material only delays the heat propagation, it is difficult to prevent the occurrence of a fire due to thermal runaway and propagation. Summary of the Invention [Problem to be solved by the invention]

[0008] An object of the present invention is to provide a heat sink capable of preventing the occurrence of a fire due to thermal runaway of a battery cell, and a battery module including the same. [Means for solving the problem]

[0009] A heat sink according to an aspect of the present invention may absorb heat generated from a battery cell. The heat sink may include an absorbent material that absorbs a cooling liquid, and an exterior material in which the absorbent material is housed while absorbing the cooling liquid.

[0010] The cooling liquid may be water mixed with an additive, the additive being a substance that improves the fire extinguishing ability of the cooling liquid.

[0011] The absorbent material may comprise a superabsorbent polymer or a superabsorbent fiber.

[0012] The exterior material may include a vent configured to discharge the vaporized cooling liquid when the cooling liquid is vaporized and the internal pressure of the exterior material increases.

[0013] The exterior material may include a storage section that stores the absorbent material, and a sealing section located on at least a portion of a periphery of the storage section. The sealing section may include a first sealing section and a second sealing section having a sealing strength lower than that of the first sealing section.

[0014] The area of ​​the second sealing portion may be smaller than the area of ​​the first sealing portion.

[0015] According to an aspect of the present invention, a battery module may include a housing, a plurality of battery cells accommodated in the housing, and at least one heat sink accommodated in the housing and in contact with the battery cells. The heat sink may include an absorbent material that absorbs a cooling liquid, and an exterior material that is accommodated in the absorbent material while the absorbent material has absorbed the cooling liquid.

[0016] The heat sink may be disposed between the plurality of battery cells.

[0017] The heat absorber may include one heat absorber having a first thickness, and another heat absorber having a second thickness greater than the first thickness and positioned more inward than the one heat absorber.

[0018] The battery module may further include a thermally conductive member in contact with the plurality of battery cells and the heat sink.

[0019] The heat sink may be disposed between the plurality of battery cells and an inner surface of the housing.

[0020] The battery module may further include a thermally conductive member that is in contact with the plurality of battery cells and is disposed on an opposite side of the heat sink with the plurality of battery cells interposed therebetween.

[0021] The battery module may further include a heat sink in contact with an outer surface of the housing and facing the thermally conductive member across the housing.

[0022] The exterior material may include a vent configured to discharge the vaporized cooling liquid when the cooling liquid is vaporized and the internal pressure of the exterior material increases.

[0023] The side of the exterior material on which the vent is provided may correspond to a side of the battery cell from which an electrode lead protrudes.

[0024] The venting portion may face an electrode lead of the battery cell in a stacking direction or an overall width direction of the battery cell.

[0025] The battery cell may be provided with a gas venting portion configured to exhaust internal gas of the battery cell, and an edge of the exterior material on which the venting portion is provided may correspond to an edge of the battery cell on which the gas venting portion is provided.

[0026] The battery cell may be provided with a gas venting portion configured to exhaust internal gas of the battery cell, and the venting portion may face the gas venting portion of the battery cell in the stacking direction or the overall width direction of the multiple battery cells.

[0027] At least one vent hole may be formed in the housing, and the vent portion may be non-overlapping with the vent hole in a penetration direction of the vent hole.

[0028] A pair of the vents may be provided, each vent facing a different battery cell. Effect of the Invention

[0029] According to a preferred aspect of the present invention, the heat absorber may include an absorbent material that has absorbed a cooling liquid and an exterior material that contains the absorbent material. Since such a heat absorber has a large heat absorption capacity relative to its volume, when the heat absorber is provided in the battery module, the battery cell can effectively dissipate heat while minimizing a decrease in the energy density of the battery module.

[0030] The cooling liquid may be mixed with an additive that improves fire extinguishing ability, so that the vapor generated by the evaporation of the cooling liquid due to high heat caused by thermal runaway of the battery cells is discharged to the outside of the exterior material, thereby effectively preventing the occurrence of a fire.

[0031] In addition, the present invention may have other effects that can be easily predicted by a person skilled in the art from a configuration according to a preferred embodiment of the present invention. [Brief description of the drawings]

[0032] 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 facilitate a better understanding of the technical concepts of the present invention. Therefore, the present invention should not be interpreted as being limited solely to the matters depicted in such drawings. [Figure 1] 1 is a perspective view of a battery module according to a first embodiment of the present invention; [Diagram 2] 2 is a cross-sectional view taken along line AA' in FIG. [Diagram 3] 3 is a cross-sectional view showing a modified example of the battery module shown in FIG. 2. [Figure 4] 2 is a cross-sectional view taken along line BB' in FIG. [Diagram 5] FIG. 1 is an exploded perspective view of a heat sink according to a first embodiment of the present invention. [Figure 6] 6 is a schematic diagram showing a mode in which a cooling liquid is absorbed into the absorbent material shown in FIG. 5. FIG. [Figure 7] FIG. 1 is a diagram showing the appearance of a heat absorber according to a first embodiment of the present invention. [Figure 8] 1 is a flow chart showing a method for manufacturing a heat sink according to a first embodiment of the present invention. [Figure 9] FIG. 11 is a schematic diagram showing an arrangement of a heat absorber and battery cells in a second embodiment of the present invention. [Figure 10] FIG. 11 is a schematic diagram showing an arrangement of a heat absorber and battery cells according to a third embodiment of the present invention. [Figure 11] FIG. 11 is a schematic diagram showing an arrangement of a heat absorber and battery cells according to a fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. However, the present invention may be embodied in various different forms and should not be construed as being limited to the following embodiments.

[0034] In order to clearly explain the present invention, detailed descriptions of parts that are not relevant to the description or related known technologies that may obscure the gist of the present invention will be omitted, and in this specification, when adding reference numbers to components in each drawing, the same reference numbers will be used for identical or similar components throughout the specification.

[0035] Furthermore, the terms and words used in this specification and the claims should not be interpreted limited to their ordinary and dictionary meanings, but should be interpreted in a way that is consistent with the technical ideas of the present invention, based on the principle that the inventor himself / herself can appropriately define the concepts of terms in order to explain the invention in the best possible manner.

[0036] FIG. 1 is an oblique view of a battery module according to a first embodiment of the present invention, FIG. 2 is a cross-sectional view along A-A' in FIG. 1, FIG. 3 is a cross-sectional view showing a modified example of the battery module shown in FIG. 2, and FIG. 4 is a cross-sectional view along B-B' in FIG. 1.

[0037] Referring to FIG. 1, a battery module 100 according to a first embodiment of the present invention may include a housing 110, a plurality of battery cells 101 housed in the housing 110, and at least one heat sink 120 housed in the housing 110 and in contact with the battery cells 101.

[0038] The battery cells 101 may be arranged in parallel to each other. The battery cells 101 may be stacked on each other. More specifically, the battery cells 101 may be vertically arranged in the housing 110 and stacked in the horizontal direction. However, the present invention is not limited to this.

[0039] The battery cell 101 may be a pouch-type battery cell in which an electrode assembly is housed in a pouch-type battery case, but is not limited to this.

[0040] Furthermore, a pair of electrode leads 102 provided in a battery cell 101 and having opposite electrodes may protrude in opposite directions. However, this is not limited thereto, and the pair of electrode leads 102 may of course protrude parallel to each other. The direction in which the multiple battery cells 101 are stacked and the direction in which the electrode leads 102 protrude from each battery cell 101 may be perpendicular to each other. The electrode leads 102 of the multiple battery cells 101 may be electrically connected to each other by a bus bar (not shown) or the like.

[0041] The housing 110 may accommodate the multiple battery cells 101. For example, the housing 110 may include an upper plate 111 located above the multiple battery cells 101, a lower plate 112 located below the multiple battery cells 101, and a pair of side plates 113 located on both sides of the multiple battery cells 101. At least one of the upper plate 111, the lower plate 112, and the pair of side plates 113 may be integrally formed. However, this is not limited thereto, and the upper plate 111, the lower plate 112, and the pair of side plates 113 may each be formed as separate members and fastened to each other. In addition, the housing 110 may further include a pair of end covers (not shown) that cover the multiple battery cells 101 in the front-rear direction.

[0042] The configuration of the housing 110 is not limited to this, and it goes without saying that the housing 110 may be configured in the form of a monoframe or a U-shaped frame.

[0043] At least one vent hole 111a may be formed in the housing 110. More specifically, at least one vent hole 111a may be formed in the upper plate 111. When gas leaks from the battery cell 101 due to an abnormal operation of the battery cell 101, the gas can be discharged through the vent hole 111a. This makes it possible to prevent the internal pressure in the battery module 100 from becoming too high, thereby preventing an explosion.

[0044] The heat sink 120 may be disposed inside the housing 110 so as to be in contact with the battery cells 101. The battery module 100 may include at least one heat sink 120, and preferably multiple heat sinks 120.

[0045] The heat absorber 120 can dissipate heat generated from the battery cell 101. In addition, if a fire or the like occurs in the battery cell 101, a cooling liquid 121 (see FIG. 6) described below in the heat absorber 120 can be vaporized and discharged from the heat absorber 120 to perform a fire extinguishing function. More specifically, the vaporized cooling liquid 121 can lower the temperature of flammable gases generated from the battery cell 101 and remove solid emitted particles (e.g., sparks) generated from the battery cell 101, thereby significantly reducing the possibility of flames occurring.

[0046] The detailed structure and function of the heat absorber 120 will be described below.

[0047] Each heat absorber 120 may be disposed between the plurality of battery cells 101 or between the plurality of battery cells 101 and the inner surface of the housing 110. The heat absorber 120 disposed between the plurality of battery cells 101 may be named a first heat absorber 120a, and the heat absorber 120 disposed between the plurality of battery cells 101 and the inner surface of the housing 110 may be named a second heat absorber 120b.

[0048] The battery module 100 may include at least one of the first heat absorber 120a and the second heat absorber 120b. In the following, a case where the battery module 100 includes the first heat absorber 120a and the second heat absorber 120b will be described as an example.

[0049] At least one first heat absorber 120a may be provided. Each first heat absorber 120a may be disposed between the plurality of battery cells 101. Thus, each first heat absorber 120a may be in contact with a pair of battery cells 101. At least some of the plurality of battery cells 101 may be stacked with the first heat absorber 120a sandwiched therebetween. The first heat absorber 120a preferably has a size and shape similar to those of the battery cells 101.

[0050] At least one second heat sink 120b may be provided. Each second heat sink 120b may be in contact with at least a portion of the plurality of battery cells 101.

[0051] The second heat absorber 120b may be in contact with a portion of the periphery of the battery cell 101 from which the electrode lead 102 does not protrude. For example, when the battery cell 101 is vertically stood, the second heat absorber 120b may be located above or below the plurality of battery cells 101. In this case, as shown in Figures 2 and 4, the second heat absorber 120b may be located between the upper plate 111 and the plurality of battery cells 101, or between the lower plate 112 and the plurality of battery cells 101. The second heat absorber 120b may be in contact with the first heat absorber 120a.

[0052] However, the present invention is not limited to this, and the second heat absorber 120b may be in contact with one side of the battery cell 101, particularly the outermost battery cell 101. For example, when the battery cells 101 are stood vertically, the second heat absorber 120b may be located near the outermost battery cell 101. In this case, the second heat absorber 120b may be located between the side plate 113 and the outermost battery cell 101.

[0053] 3, the thicknesses of at least some of the first heat absorbers 120a may be different from each other. More specifically, the first heat absorbers 120a may include one first heat absorber 120a having a first thickness (t1) and another first heat absorber 120a having a second thickness (t2) thicker than the first thickness (t1) and positioned inside the one first heat absorber 120a. The thicknesses of the first heat absorbers 120a may be formed to be thicker toward the inside. This can improve the heat dissipation performance and fire extinguishing function for the inner battery cells 101 where heat is concentrated and there is a high possibility of thermal runaway.

[0054] Meanwhile, the battery module 100 may further include a thermally conductive member 150 in contact with the plurality of battery cells 101 and / or a heat sink 160 in contact with the outer surface of the housing 110 .

[0055] The thermally conductive member 150 may be located between the plurality of battery cells 101 and the inner surface of the housing 110. The thermally conductive member 150 may be a member that assists in thermal conduction between the housing 110 and the plurality of battery cells 101. For example, the thermally conductive member 150 may be a thermally conductive adhesive. This allows heat generated from the plurality of battery cells 101 to be rapidly conducted to the housing 110 and a heat sink 160, which will be described later, via the thermally conductive member 150.

[0056] The thermal conductive member 150 may be in contact with the first heat absorber 120a. Thus, heat absorbed by the first heat absorber 120a from the battery cell 101 may be rapidly conducted to the housing 110 and a heat sink 160 (described later) via the thermal conductive member 150.

[0057] The first heat absorber 120a may have a folded portion 143 (see FIGS. 5 and 7) which will be described later in detail, in contact with the heat conductive member 150. Since the folded portion 143 protrudes a little more from the accommodating portion 144 than the sealing portion 145, the cooling liquid 121 and the absorbent 130 in the accommodating portion 144 may be cooled more quickly than when the sealing portion 145 contacts the heat conductive member 150.

[0058] The heat conducting member 150 may be disposed on the opposite side of the second heat sink 120b across the multiple battery cells 101. This allows heat from the multiple battery cells 101 to be dissipated efficiently.

[0059] For example, the second heat absorber 120b may be located above the multiple battery cells 101, and the heat conductive member 150 may be located below the multiple battery cells 101. In other words, the second heat absorber 120b may be located between the upper plate 111 and the multiple battery cells 101, and the heat conductive member 150 may be located between the lower plate 120 and the multiple battery cells 101.

[0060] The heat sink 160 may be in contact with the outer surface of the housing 110 and face the thermally conductive member 150 across the housing 110. Therefore, heat generated from the multiple battery cells 101 can be quickly conducted to the heat sink 160 via the thermally conductive member 150 and the housing 110.

[0061] For example, the thermally conductive member 150 may be located below the multiple battery cells 101, and the heat sink 160 may be in contact with the bottom surface of the housing 110. That is, the thermally conductive member 150 and the heat sink 160 may face each other with the lower plate 112 in between.

[0062] FIG. 5 is an exploded perspective view of a heat absorber according to a first embodiment of the present invention, FIG. 6 is a schematic diagram showing a manner in which a cooling liquid is absorbed into the absorbent material shown in FIG. 5, and FIG. 7 is a diagram showing the appearance of the heat absorber according to the first embodiment of the present invention.

[0063] The configuration of the heat absorber 120 according to the first embodiment will be described below with reference to FIGS.

[0064] The heat absorber 120 according to the first embodiment of the present invention may absorb heat generated from the battery cell 101 as described above.

[0065] More specifically, the heat absorber 120 includes an absorbent material 130 that absorbs the cooling liquid 121, and an exterior material 140 in which the absorbent material 130 is housed while it has absorbed the cooling liquid 121.

[0066] The cooling liquid 121 may be a liquid with excellent heat absorption capacity. Preferably, the cooling liquid 121 may be water. Water has excellent heat absorption capacity due to its specific heat (1.0 kcal / kg) and latent heat of vaporization (539 kcal / kg), and is advantageous for cooling and extinguishing a fire. In addition, since water has a very large vaporization expansion rate of approximately 1700 times, vaporized water vapor can cover the burning surface and suffocate the fire.

[0067] An additive may be mixed into the cooling liquid 121. The additive may be a material that improves the fire extinguishing ability of the cooling liquid 121. There is no limitation on the additive, and any material that improves the fire extinguishing ability of the cooling liquid 121 may be used without limitation.

[0068] When the cooling liquid 121 is water, the additive may include at least one of the following: an antifreeze that lowers the freezing point of water, a penetrant that lowers the surface tension of water to increase the penetration effect, a thickener that increases the viscosity of water to prevent water loss, a density improver, and an emulsifier that increases the fire extinguishing effect for high boiling point oils. These types of additives are well known substances, so detailed explanations will be omitted.

[0069] The additive may also include a negative catalytic agent that prevents a continuous chain reaction of combustible materials from occurring. For example, the additive may include salts, more specifically, the alkali metal salts potassium carbonate and ammonium phosphate.

[0070] Also, commercially available fire extinguishing agents may be used as additives, for example, F-500 Encapsulator Agent (F-500EA) from Hazard Control Technologies.

[0071] The absorbent material 130 may be made of a material having high water absorption properties in order to sufficiently absorb the cooling liquid 120. Preferably, the absorbent material 130 may include a super absorbent polymer (SAP) or a super absorbent fiber (SAF).

[0072] Superabsorbent polymers and highly water-absorbent fibers can absorb tens to hundreds of times their own weight in solution. They have a three-dimensional network structure in which minute pores are formed, and a large number of hydrophilic groups, so they do not dissolve in solutions such as water and can absorb large amounts of solution. In particular, when superabsorbent polymers absorb solution, they can swell significantly from their existing shape and turn into a gel.

[0073] The exterior material 140 may be sealed after containing the absorbent material 130 that has absorbed the cooling liquid 121.

[0074] For example, the exterior material 140 may be manufactured by forming a laminate sheet. The laminate sheet may have a well-known structure formed in a typical pouch-type battery case. More specifically, the exterior material 140 may include an outer polymer layer located on the outermost side, an inner polymer layer located on the innermost side, and a metal layer located between the outer polymer layer and the inner polymer layer.

[0075] The metal layer may have a certain level of mechanical strength, is light in weight, and may prevent leakage of a cooling liquid and ensure heat dissipation. For example, the metal layer may include aluminum.

[0076] The outer polymer layer can protect the heat absorber 120 from external friction and impact. For example, the outer polymer layer can be made of a polyethylene terephthalate (PET) material. However, the outer polymer layer is not limited thereto, and various materials can be used as the outer polymer layer according to need.

[0077] The inner polymer layers may be layers that are fused together when sealing the exterior material 140. The inner polymer layers are in contact with the cooling liquid and must have corrosion resistance and completely seal the inside, so they can have high sealing properties. That is, the sealing portion bonded to the inner polymer layers can have excellent thermal adhesive strength. For example, the inner polymer layers may be made of polypropylene (PP) or polyethylene (PE). However, the materials are not limited thereto, and various materials forming the inner polymer layers may be selected as necessary.

[0078] Meanwhile, the exterior material 140 may include a first exterior material 141 and a second exterior material 142. At least one of the first exterior material 141 and the second exterior material 142 may have a recessed storage section 144 in which the absorbent material 130 is stored.

[0079] The first outer material 141 and the second outer material 142 are connected by a folding portion 143, and when the folding portion 143 is folded, the absorbent material 130 may be housed between the first outer material 141 and the second outer material 142. However, this is not limited thereto, and the first outer material 141 and the second outer material 142 may be manufactured separately from each other.

[0080] The area where the first exterior material 141 and the second exterior material 142 abut against each other may be fused and sealed together by heat and pressure, and the area may be referred to as a sealing portion 145.

[0081] The sealing portion 145 may be formed on at least a portion of the periphery of the receiving portion 144. For example, the sealing portion 145 may be located on three of the four sides of the receiving portion 144, and the folding portion 143 may be located on the remaining side. If the first exterior material 141 and the second exterior material 142 are manufactured separately from each other, it can be easily understood by those skilled in the art that the sealing portion 145 can be located on the four sides of the receiving portion 144.

[0082] However, the configuration of the exterior material 140 is not limited thereto, and the configuration is not limited as long as it can accommodate the absorbent material 130 (FIG. 6) that has absorbed the cooling liquid. As another example, the exterior material 140 may include a case having an open end and a cap that seals the case.

[0083] Meanwhile, the exterior material 140 may be provided with a venting unit 147 configured to discharge the vaporized cooling liquid when the cooling liquid 121 is vaporized and the internal pressure of the exterior material 140 increases. The configuration of the venting unit 147 is not limited, and those skilled in the art may implement the venting unit 147 in various ways.

[0084] For example, the venting portion 147 may include a weak sealing portion configured to be preferentially broken when the cooling liquid 121 evaporates and the internal pressure of the exterior material 140 increases. Hereinafter, for convenience of explanation, the weak sealing portion will be denoted by the reference numeral "147" like the venting portion.

[0085] The weak sealing portion 147 may be formed by sealing a portion of the sealing portion 145 weaker than the surrounding area. More specifically, if a fire or the like occurs in the battery cell 101 and the temperature rises excessively, the cooling liquid 121 absorbed in the absorbent 130 is vaporized by the heat absorbed by the heat absorber 120, and the internal pressure of the exterior material 140 increases, so that the weak sealing portion 147 may be broken preferentially. As a result, the vapor of the vaporized cooling liquid 121 quickly diffuses within the battery module 100 to perform a fire extinguishing function.

[0086] More specifically, the sealing portion 145 of the exterior material 140 may include a first sealing portion 146 and a second sealing portion 147 having a sealing strength lower than that of the first sealing portion 146. The second sealing portion 147 may be named a weak sealing portion.

[0087] The sealing part 145 may be formed by fusing the inner polymer layers of the exterior material 140 together using heat and pressure applied by a sealing tool. In this process, the first sealing part 146 and the second sealing part 147 may be formed to have different sealing strengths by making the pressure, temperature, and pressurizing time of the sealing tool different from each other. Alternatively, the sealing strengths may be made different from each other through a polymer recrystallization process of the inner polymer layers.

[0088] However, the present invention is not limited thereto, and a material that weakens the sealing strength at high temperatures may be inserted into the second sealing part 147. More specifically, the material may melt at a temperature that is the same as or similar to the temperature at which the cooling liquid 121 evaporates, and when the material melts, the sealing strength of the second sealing part 147 becomes weak, and breakage may occur quickly. The type of the material is not limited.

[0089] The area of ​​the second sealing portion 147 may be smaller than the area of ​​the first sealing portion 146. This allows the overall sealing strength of the sealing portion 145 to be maintained high.

[0090] As described above, the configuration of the venting portion 147 is not limited to a weak sealing portion, and may be embodied in other ways. For example, the venting portion 147 may include a venting valve that is mechanically opened and closed by the internal pressure of the exterior material 140. Typically, such a venting valve may include a sheet having a passage formed therein, a valve body that opens and closes the passage, and an elastic member that applies a force to the valve body in a direction that closes the passage. Since the venting valve is a well-known configuration, a person skilled in the art can easily understand the configuration and operation of the venting valve.

[0091] The function of the heat absorber 120 will now be described.

[0092] The heat absorber 120 can absorb heat generated during charging and discharging of the battery cell 101 to maintain a low temperature of the battery cell 101. In particular, the cooling liquid 121 in the heat absorber 120 has a high heat absorption capacity, and therefore can provide a high heat dissipation effect.

[0093] If a safety problem such as thermal runaway or fire occurs in the battery cell 101, the cooling liquid 121 in the heat absorber 120 may be vaporized as steam due to high heat and may be discharged into the battery module 100 through the venting part 147 of the exterior material 140. Since an additive that improves fire extinguishing ability is mixed into the steam, it is possible to lower the temperature of flammable gases generated from the battery cell 101 and remove solid emitted particles (e.g., sparks) generated from the battery cell 101, thereby significantly reducing the possibility of fire occurrence.

[0094] Meanwhile, the venting portion 147 of the exterior material 140 may not overlap the venting hole 111a (see FIG. 1) formed in the housing 110 in the penetration direction of the venting hole 111a. More specifically, at least one venting hole 111a may be formed in the upper surface of the housing 110, and the venting portion 147 may not overlap the venting hole 111a in the vertical direction.

[0095] This delays the vaporized cooling liquid discharged from the venting portion 147 from escaping into the venting hole 111a of the housing 110, and allows the liquid to remain within the battery module 100, thereby enabling the fire extinguishing action to be performed sustained and reliably.

[0096] FIG. 8 is a flow chart of a method for manufacturing a heat sink according to a first embodiment of the present invention.

[0097] Below, any content that overlaps with the above content is incorporated by reference.

[0098] The manufacturing method of the heat absorber 120 may include a step (S20) of absorbing the cooling liquid 121 into the absorbent 130, a step (S30) of housing the absorbent 130 in the exterior material 140, and a step (S40) of sealing the exterior material 140. The manufacturing method may further include a step (S10) of preparing the cooling liquid 121.

[0099] For example, in the step of preparing the cooling liquid 121 (S10), the cooling liquid 121 can be prepared by mixing an additive into water.

[0100] The step (S20) of absorbing the cooling liquid 121 into the absorbent 130 and the step (S30) of housing the absorbent 130 in the exterior material 140 may be performed in this order. However, the present invention is not limited thereto, and the cooling liquid 121 may be absorbed into the absorbent 130 while the absorbent 130 is housed in the exterior material 140, more specifically, in the housing portion 144.

[0101] In the step of sealing the exterior material 140 (S40), a sealing tool may apply heat and pressure to the exterior material 140, more specifically, to the area where the first exterior material 141 and the second exterior material 142 abut against each other, to form a sealing portion 145.

[0102] More specifically, the step of sealing the exterior material 140 (S40) may include a process of forming a first sealing portion 146 and a process of forming a second sealing portion 147 having a sealing strength lower than that of the first sealing portion 146. As described above, the process of forming the first sealing portion 146 and the process of forming the second sealing portion 147 may differ from each other in terms of the pressure, temperature, pressurization time, etc. of the sealing tool. Alternatively, during the process of forming the second sealing portion 147, a material that weakens the sealing strength at high temperatures may be inserted into the portion that will become the second sealing portion 147.

[0103] Alternatively, in the step of sealing the exterior material 140 (S40), a venting valve may be sealed between the first exterior material 141 and the second exterior material 142. In this case, the venting valve may be fixed to the sealing portion 145 and may function as the venting portion 147.

[0104] 9 is a schematic diagram showing an arrangement of a heat absorber and battery cells in the second embodiment of the present invention. The heat absorber 120 shown in FIG 9 is the first heat absorber 120a described above.

[0105] In the battery module 100 according to the second embodiment, the side where the venting portion 147 is provided in the exterior material 140 of the heat sink 120 may correspond to the side where the electrode lead 102 of the battery cell 101 protrudes.

[0106] 9, the electrode leads 102 may protrude from both short sides 101a of the battery cell 101. In this case, the venting portions 147 may be provided on both short sides of the exterior material 140 of the heat sink 120.

[0107] As a result, flammable gas discharged to the peripheral area of ​​the electrode lead 102 of the battery cell 101 can be quickly extinguished by the vaporized cooling liquid discharged to the venting portion 147 .

[0108] If abnormally high temperature or thermal runaway occurs due to abnormal operation of the battery cell 101, the sealing around the electrode lead 102, which has a relatively weak sealing force in the battery cell 101, may be destroyed, causing flammable gas to be rapidly discharged. Since the venting portion 147 of the heat sink 120 is located close to the point where the flammable gas is discharged in the battery cell 101, i.e., the periphery of the electrode lead 102, the fire extinguishing function for the flammable gas can be improved.

[0109] Furthermore, in the battery module 100 according to the second embodiment, the venting portion 147 of the heat absorber 120 may face the electrode lead 102 of the battery cell 101. More specifically, the venting portion 147 of the heat absorber 120 may face the electrode lead 102 of the battery cell 101 in the stacking direction (direction parallel to the Y axis) or the overall width direction (direction parallel to the Z axis) of the battery cell 101. The electrode lead 102 may include not only a portion protruding from the battery cell 101 but also a portion located inside the battery cell 101.

[0110] More specifically, the venting portion 147 of the first heat absorber 120a may face the electrode lead 102 of the battery cell 101 in the stacking direction (direction parallel to the Y-axis) of the battery cell 101. Although not shown in Fig. 9, the venting portion 147 of the second heat absorber 120b may face the electrode lead 102 of the battery cell 101 in the overall width direction of the battery cell 101 (direction parallel to the Z-axis).

[0111] As a result, flames and / or gases discharged to the peripheral areas of the electrode leads 102 of the battery cells 101 can be quickly extinguished by the vaporized cooling liquid discharged to the venting portion 147 .

[0112] 10 is a schematic diagram showing an arrangement of a heat absorber and battery cells according to a third embodiment of the present invention. The heat absorber 120 shown in FIG 10 is the first heat absorber 120a described above.

[0113] The battery cell 101 may be provided with a gas venting portion 103 configured to exhaust internal gas of the battery cell 101. When the internal pressure of the battery cell 101 increases, the gas within the battery cell 101 may be exhausted through the gas venting portion 103.

[0114] 10 shows an embodiment in which the gas venting portion 103 is provided on the long side 101b of the battery cell 101. However, the position of the gas venting portion 103 is not limited, and it goes without saying that the gas venting portion 103 may be provided on the short side 101a of the battery cell 101.

[0115] The configuration of the gas venting unit 103 is not limited, and those skilled in the art may realize the gas venting unit 103 in various ways.

[0116] For example, the gas venting portion 103 may include a weak sealing portion configured to be preferentially broken when the internal pressure of the battery cell 101 increases. The weak sealing portion may be formed by sealing a portion of the sealing portion of the pouch weaker than the surrounding area.

[0117] The configuration of the gas venting part 103 is not limited to a weak sealing part and may be embodied in other ways. As another example, the gas venting part 103 may include a venting valve that is mechanically opened and closed according to the internal pressure of the battery cell 101. As yet another example, the gas venting part 103 may include a permeable member through which gas can pass. The permeable member may include an olefin-based polymer or a fluorine-based polymer material such as PTFE (Polytetrafluoroethylene).

[0118] In the battery module 100 according to the third embodiment, the side of the exterior material 140 of the heat absorber 120 on which the venting portion 147 is provided may correspond to the side of the battery cell 101 on which the gas venting portion 103 is provided.

[0119] 10, the gas venting portion 103 may be provided on a long side 101b of the battery cell 101. In this case, the venting portion 147 may be provided on a long side of the exterior material 140 of the heat absorber 120.

[0120] As a result, the flammable gas discharged to the gas venting portion 103 of the battery cell 101 can be quickly extinguished by the vaporized cooling liquid discharged to the venting portion 147 of the heat absorber 120 .

[0121] When abnormal high temperature or thermal runaway occurs due to abnormal operation of the battery cell 101, the internal pressure of the battery cell 101 increases and flammable gas may be rapidly discharged to the gas venting part 103. Since the venting part 147 of the heat absorber 120 is located close to the point where the flammable gas is discharged from the battery cell 101, i.e., the gas venting part 103, the fire extinguishing function for the flammable gas can be improved.

[0122] Furthermore, in the battery module 100 according to the third embodiment, the venting portion 147 of the heat absorber 120 may face the gas venting portion 103 of the battery cell 101. More specifically, the venting portion 147 of the heat absorber 120 may face the gas venting portion 103 of the battery cell 101 in the stacking direction (direction parallel to the Y-axis) or the overall width direction (direction parallel to the Z-axis) of the battery cell 101.

[0123] More specifically, the venting portion 147 of the first heat absorber 120a may face the gas venting portion 103 of the battery cell 101 in the stacking direction (direction parallel to the Y-axis) of the battery cell 101. Although not shown in Fig. 10, the venting portion 147 of the second heat absorber 120b may face the gas venting portion 103 of the battery cell 101 in the overall width direction of the battery cell 101 (direction parallel to the Z-axis).

[0124] As a result, flames and / or gases discharged to the peripheral areas of the electrode leads 102 of the battery cells 101 can be quickly extinguished by the vaporized cooling liquid discharged to the venting portion 147 .

[0125] 11 is a schematic diagram showing an arrangement of a heat absorber and battery cells according to a fourth embodiment of the present invention. A heat absorber 120' shown in FIG 11 is the first heat absorber 120a described above.

[0126] The heat absorber 120' according to this embodiment may include an outer casing 140' that houses an absorbent 130 (FIG. 6) that has absorbed a cooling liquid, and a venting portion 149 configured to discharge the vaporized cooling liquid when the cooling liquid 121 vaporizes and the internal pressure of the outer casing 140 increases.

[0127] The configuration of the venting part 149 is not limited, and those skilled in the art may implement the venting part 149 in various ways. As an example, an opening may be formed in the exterior material 140', and a cover covering the opening may be sealed to the exterior material 140' to form the venting part 149. In this case, when the internal pressure of the exterior material 140' exceeds a certain level, the seal between the cover and the exterior material 140' may be broken, and the vaporized cooling liquid may be discharged to the opening.

[0128] The exterior material 140′ may be provided with a pair of venting portions 149. The pair of venting portions 149 may be directed toward different battery cells 101.

[0129] More specifically, the pair of venting portions 149 may be provided on both sides of the exterior material 140'. More specifically, one of the pair of venting portions 149 may be provided on one side of the exterior material 140' and may face one battery cell 101. Furthermore, the other of the pair of venting portions 149 may be provided on the other side of the exterior material 140'. The one venting portion may be named a first venting portion, and the other venting portion may be named a second venting portion.

[0130] When the internal pressure in the heat absorber 120' rises, as long as a flame occurs or flammable gas is discharged, the venting portion 149 of the pair of venting portions 149 that faces the battery cell 101 may be opened first. That is, the venting portion 149 is preferably configured so that opening is promoted by high temperature. For example, sealing may be performed with a material that weakens the sealing strength at high temperature inserted between the exterior material 140' and a cover that covers the opening formed in the exterior material 140'. However, the present invention is not limited to this.

[0131] As a result, the vaporized cooling liquid can be discharged from the vent 149 toward the battery cell 101 where the flame occurs or the flammable gas is discharged, so that the fire can be extinguished more quickly.

[0132] The above description is merely an illustrative example of the technical concept of the present invention, and various modifications and variations can be made by those having ordinary knowledge in the technical field to which the present invention pertains without departing from the essential characteristics of the present invention.

[0133] Therefore, the embodiments disclosed in the present invention are intended to explain the technical idea of ​​the present invention, rather than to limit it, and the scope of the technical idea of ​​the present invention is not limited by such embodiments.

[0134] The scope of protection of the present invention should be interpreted according to the following claims, and all technical ideas within the scope equivalent thereto should be interpreted as being included in the scope of the present invention. [Explanation of symbols]

[0135] 100 Battery Module 101 Battery Cell 110 Housing 120 Heat absorber 121 Cooling Fluid 130 Absorbent 140 Exterior materials 150 Heat transfer components 160 Heatsink

Claims

1. A heat sink that absorbs heat generated from a battery cell, An absorbent material for absorbing the cooling liquid; an exterior material in which the absorbent material is accommodated while absorbing the cooling liquid; A heat absorber comprising:

2. The cooling liquid is water mixed with an additive, The heat sink of claim 1 , wherein the additive is a material that improves the fire extinguishing ability of the cooling liquid.

3. The heat sink of claim 1 , wherein the absorbent material comprises a superabsorbent polymer or fiber.

4. The heat sink according to claim 1 , wherein the exterior material is provided with a venting portion configured to discharge the vaporized cooling liquid when the cooling liquid vaporizes and the internal pressure of the exterior material increases.

5. The exterior material is A storage section that stores the absorbent material; a sealing portion located on at least a portion of the periphery of the housing portion; Including, The sealing portion is A first sealing portion; a second sealing portion having a lower sealing strength than the first sealing portion; The heat sink according to claim 1 , comprising:

6. The heat sink according to claim 5 , wherein an area of ​​the second sealing portion is smaller than an area of ​​the first sealing portion.

7. Housing and A plurality of battery cells accommodated in the housing; At least one heat sink accommodated in the housing and in contact with the battery cell; Including, The heat sink is An absorbent material for absorbing the cooling liquid; An exterior material in which the absorbent material is accommodated in a state in which the absorbent material has absorbed the cooling liquid; a battery module including:

8. The battery module according to claim 7 , wherein the heat sink is disposed between the plurality of battery cells.

9. The heat sink is a heat sink having a first thickness; Another heat absorber has a second thickness greater than the first thickness and is positioned more inward than the first heat absorber; The battery module of claim 8 .

10. The battery module according to claim 8 , further comprising a thermally conductive member in contact with the plurality of battery cells and the heat sink.

11. The battery module according to claim 7 , wherein the heat sink is disposed between the plurality of battery cells and the inner surface of the housing.

12. The battery module according to claim 11 , further comprising a thermally conductive member in contact with the plurality of battery cells and disposed on the opposite side of the heat sink with the plurality of battery cells interposed therebetween.

13. The battery module according to claim 10 or 12, further comprising a heat sink in contact with an outer surface of the housing and facing the thermally conductive member across the housing.

14. The exterior material includes: The battery module according to claim 7 , further comprising a venting portion configured to discharge the vaporized cooling liquid when the cooling liquid is vaporized and the internal pressure of the exterior material increases.

15. The battery module according to claim 14 , wherein a side of the exterior material on which the venting portion is provided corresponds to a side of the battery cell from which an electrode lead protrudes.

16. The battery module according to claim 14 , wherein the venting portion faces an electrode lead of the battery cell in a stacking direction or an overall width direction of the battery cells.

17. The battery cell includes a gas venting portion configured to exhaust internal gas of the battery cell, The battery module according to claim 14 , wherein a side of the exterior material on which the venting portion is provided corresponds to a side of the battery cell on which the gas venting portion is provided.

18. The battery cell includes a gas venting portion configured to exhaust internal gas of the battery cell, The battery module according to claim 14 , wherein the venting portion faces the gas venting portion of the battery cell in a stacking direction or an overall width direction of the plurality of battery cells.

19. The housing has at least one vent hole formed therein, The battery module according to claim 14 , wherein the venting portion does not overlap the venting hole in a penetration direction of the venting hole.

20. The battery module according to claim 14 , wherein the venting portion includes a pair of venting portions each directed toward a different battery cell.

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