Endothermic device

Abstract

Disclosed in the present specification are a composite material, an endothermic device, a method for manufacturing same, and a use of the composite material. The composite material can be applied to products or devices which generate heat or have a possibility of ignition or explosion during operation, storage, and / or maintenance, so as to effectively respond to the heat, ignition, and explosion. For example, the composite material can be applied to an article including a plurality of the products or devices, so as to respond to abnormal heat generation, explosion and ignition that occur in any one device or product, and to prevent or minimize propagation of the heat generation, explosion and ignition to other adjacent devices or products.

Description

heat absorbing device

[0001] This application claims the benefit of priority to Republic of Korea Patent Application No. 10-2024-0103466, filed August 2, 2024, and Republic of Korea Patent Application No. 10-2024-0174257, filed November 28, 2024, the entire contents of which are incorporated herein by reference.

[0002] The present specification discloses a heat absorbing device and a use of the heat absorbing device.

[0003] The importance of technology to manage heat generated from products is increasing, but it is a difficult problem to manage, control, and manage heat in products composed of multiple heat-generating elements (heat-generating elements).

[0004] For example, it is very important to prevent the so-called TR (Thermal Runaway) or TP (Thermal Propagation) phenomenon that occurs in battery modules or battery packs. A battery module or battery pack includes multiple battery cells or multiple battery modules, which are positioned relatively adjacent to each other. In such a structure, the phenomenon in which abnormal heat generation, ignition, and / or explosion occurring in one battery cell and / or battery module is transmitted in a chain reaction to other adjacent battery cells is called the TR or TP phenomenon. The chain reaction of ignition or explosion caused by this TR or TP phenomenon must be managed from a safety perspective.

[0005] The present specification discloses a heat absorbing device and its use. The purpose of the present specification is to disclose a heat absorbing device that can be applied to products or components that have the potential for abnormal heat generation, ignition, and / or explosion during operation, storage, and / or maintenance, and can effectively counteract such heat generation, ignition, and explosion.

[0006] For example, the heat absorbing device disclosed herein can be applied to an article including a plurality of the above products or elements to respond to abnormal heat generation, explosion, and / or ignition occurring in one of the elements or products, and prevent or minimize the spread of such heat generation, explosion, and / or ignition to other adjacent elements or products.

[0007] Another object of the present specification is to disclose a heat absorbing device having excellent handling and storage stability. Another object of the present specification is to disclose uses of the heat absorbing device.

[0008] Among the properties mentioned in this specification, properties that are affected by temperature are properties measured at room temperature, unless otherwise specified.

[0009] The term room temperature means a natural temperature that has not been artificially heated or cooled, for example, a temperature within the range of about 10°C to 30°C, for example, a temperature of about 23°C or about 25°C.

[0010] The unit of temperature referred to in this specification is Celsius (℃), unless otherwise specified.

[0011] Among the properties mentioned in this specification, properties affected by pressure are properties measured at atmospheric pressure, unless otherwise specified.

[0012] The term atmospheric pressure refers to natural pressure that has not been artificially pressurized or depressurized, and is usually a pressure in the range of about 700 mmHg to 800 mmHg.

[0013] Among the properties mentioned in this specification, properties affected by humidity are properties measured at room temperature and pressure without artificially controlling humidity, unless otherwise specified.

[0014] The present specification discloses a composite material.

[0015] The above composite material may include an inorganic gel.

[0016] The present specification also discloses a heat absorbing device comprising the composite material.

[0017] The above heat absorbing device may include a case having a sealed space inside and a composite material existing in the sealed space inside.

[0018] The case is a container for holding the composite material. The case has a sealed space inside. The case having a sealed space inside means that the sealed space is formed inside the case, or that a certain space exists inside the case, and although the space is not sealed, the case exists so that the sealed space can be formed by sealing the open portion.

[0019] The term "abnormal condition" as used herein refers to a condition in which abnormal heat generation, ignition and / or explosion occurs during the operation, storage and / or maintenance of any product or component, or in which there is a possibility of such abnormal heat generation, ignition and / or explosion occurring.

[0020] In this specification, the term normal state refers to the normal operation, storage and / or maintenance state of any product or device other than the above abnormal state.

[0021] The above-mentioned sealed space refers to a space formed so that the components of the composite material, etc., do not substantially leak out to the outside under normal conditions. In one example, the case may have a WVTR (Water Vapor Transmission Rate) within a predetermined range described below, and the sealed space may be substantially entirely surrounded by a case having the WVTR (Water Vapor Transmission Rate).

[0022] The above-mentioned sealed space has a vent area. The term "vent area" may refer to an area that exists to maintain a sealed state under normal conditions, but is opened under abnormal conditions to allow the discharge of substances within the space. Such a vent area may be formed in the manner described below.

[0023] In one example, the case may have a water vapor transmission rate (WVTR) within a predetermined range. For example, at least a portion of the case forming the sealed space may have a water vapor transmission rate (WVTR) within a predetermined range. For example, the upper limit of the WVTR of the above case may be about 10, 9.5, 9, 8.5, 8, 7.5, 7, 6.5, 6, 5.5, 5, 4.5, 4, 3.5, 3, 2.5, 2, 1.5, 1, 0.5, 0.45, 0.4, 0.35, 0.3, 0.25, 0.2, 0.15, 0.1, 0.05, 0.01, 0.005, or 0.001, and the lower limit may be about 0, 0.1, 0.2, 0.3, 0.4, or 0.5. The WVTR is within a range that is less than or equal to any one upper limit arbitrarily selected from the upper limits listed above; Or, it may be within a range that is equal to or greater than any lower limit arbitrarily selected from the lower limits listed above and equal to or less than any upper limit arbitrarily selected from the upper limits listed above. By having such a WVTR, storage stability of substances present within the enclosed space can be secured, and the heat absorbing device can more efficiently exhibit the intended extinguishing action.

[0024] The unit of the above WVTR (Water Vapor Transmission Rate) is g / m 2·day. The above WVTR is evaluated according to the standard of ASTM F1249 under the conditions of 38℃ and 100% relative humidity.

[0025] The above-mentioned heat absorbing device is configured to maintain a vaporizable substance contained in the composite material in the sealed space in a normal state and to release the vaporizable substance or its vaporized substance to the outside in an abnormal state.

[0026] This action is explained assuming that the above heat absorbing device is applied to a battery module.

[0027] Fig. 1 is a schematic diagram of a case where the heat absorption device (S) is applied to a battery module. As shown in Fig. 1, the battery module can be configured by arranging a plurality of battery cells (11, 12, 13, 14, 15, 16) adjacent to each other, and the heat absorption device (S) can be arranged between battery cells (for example, between 12 and 13 and / or between 14 and 15 in Fig. 1).

[0028] The above heat absorbing device (S) maintains volatile substances, etc., inside it in a normal state. When an abnormal state occurs, the internal substance of the heat absorbing device (S) is ejected through the vent area (dashed arrow in Fig. 1), and the internal substance ejected in this way can respond to heat generation and / or flames, etc. in the abnormal state. In Fig. 1, a case is described where the internal substance is ejected from both the upper and lower directions of the heat absorbing device (S), but the direction of the ejection is not limited to Fig. 1. The direction of the ejection may be one direction of the heat absorbing device (S), or may be two or more directions.

[0029] In order for the heat absorbing device to effectively perform the above function in an abnormal state, it is required that the volatile substances existing inside the case in a normal state be stably maintained, that the internal substances be able to be quickly discharged to the outside when an abnormal state occurs, and that the volatile substances existing inside the case in an abnormal state be able to be discharged to the outside in a vaporized state as much as possible so that they are consumed.

[0030] For the heat absorbing device to effectively perform the above function under ideal conditions, the vaporization rate of the vaporizable substance must be maintained appropriately. If the vaporizable substance vaporizes at an appropriate rate, the pores of the internal inorganic gel can be prevented from collapsing due to changes in surface tension, etc. following heat absorption by the vaporizable substance.

[0031] The heat absorbing device disclosed in this specification can satisfy the above requirements.

[0032] The above-mentioned heat absorbing device explains the principle by which the above-mentioned function is performed.

[0033] Fig. 2 shows only the heat absorbing device (S) in Fig. 1 separately. In a configuration such as Fig. 1, if abnormal heating, abnormal ignition, and / or abnormal explosion occurs in at least one of the battery cells adjacent to the heat absorbing device (S), a certain level of heat or more is instantaneously applied to the heat absorbing device, as indicated by the solid arrow in Fig. 2. In the sealed space inside the case (1001) of the heat absorbing device in Fig. 2, as indicated by the dotted arrow, volatile substances are randomly propagated in all directions within the space. At this time, if the WVTR of the portion forming the sealed space of the case (1001) is within the aforementioned range, the vaporized gas cannot be released to the outside, and therefore, the inside of the case (1001) becomes very high-pressure. At this time, when the vent area (1002) of the case is configured to open instantaneously at a high pressure above a certain level, the vent area (1002) is opened instantaneously at the high pressure state, and the gas inside is quickly discharged to the outside through the opened vent area (1002).

[0034] When the WVTR of the case is high, the pressure inside the case (1001) may not effectively increase in an abnormal state, so that the vent area (1002) may not be opened effectively, or even when the vent area (1002) is opened, the internal pressure may not sufficiently increase, so that the internal gas may not be completely discharged to the outside and exhausted, or the discharge speed may not be properly secured.

[0035] By keeping the WVTR of the case low, the storage stability of the internal material under normal conditions can also be effectively secured.

[0036] The method for forming the above-mentioned vent area (1002) is not particularly limited. The vent area can be formed by designing a certain area of ​​the case forming the sealed space to be opened when a certain level of pressure and / or heat is applied. For example, if a certain area of ​​the case forming the sealed space is configured to have lower strength than other areas, the area having the lower strength can be opened due to increased internal pressure. In addition, a method of forming the sealed space through sealing using a hot melt material or the like so that opening occurs by melting at a predetermined temperature can also be used. Alternatively, the vent area can be formed by making only a certain area of ​​the case forming the sealed space thinner than other areas. Such methods for forming the vent area can be easily adopted by those skilled in the art.

[0037] For example, when the heat absorbing device is applied to a battery module or pack, for convenience of application, the case may be a square case, pouch-shaped case, and / or cylindrical case having the same shape as the battery cell. In such cases, a vent area may also be formed by controlling the bonding strength of the cover forming a sealed space in the square or cylindrical case.

[0038] The above case can be constructed using a known material as long as it can satisfy the aforementioned WVTR, and the material can have a single-layer structure or a single-layer structure of two or more layers.

[0039] For example, the case can be formed using a material capable of exhibiting a WVTR in the above range among suitable organic and / or inorganic layers.

[0040] As the organic layer, for example, a known polymer film or sheet can be used. Examples of the organic film include a cellulose-based polymer film; a COP (cyclo olefin copolymer) film; an acrylic polymer film; a polyolefin film; a PVA (polyvinyl alcohol) film; a PVC (poly(vinyl chloride)) film, a PES (poly ether sulfone) film; a PEEK (polyetheretherketon) film; a PPS (polyphenylsulfone) film; a PEI (polyetherimide) film; a PEN (polyethylenemaphthatlate) film; a PET (poly(ethylene terephthalate)) film; a PI (polyimide) film; a PSF (polysulfone) film and / or a PAR (polyarylate) film.

[0041] For example, the inorganic layer may be a metal layer, a metal oxide layer, a metal nitride layer, or a metal oxynitride layer. For example, the inorganic layer may be a metal layer, a metal oxide layer, a metal nitride layer, or a metal oxynitride layer including at least one selected from the group consisting of In, Sn, Pb, Au, Cu, Ag, Zr, Hf, Zn, Al, Si, La, Ti, and Ni. For example, a foil, sheet, or film of the material may be applied, or a layer formed by depositing the metal layer, the metal oxide layer, the metal nitride layer, or the metal oxynitride layer on an appropriate substrate may be used.

[0042] For example, SUS film can be used as the above-mentioned inorganic layer.

[0043] The material forming the case may be a single layer selected from the inorganic layer and organic layer, or a multilayer structure in which two or more of the layers are laminated.

[0044] The thickness of the above-mentioned inorganic layer and / or organic layer is selected in consideration of the desired properties such as WVTR and is not particularly limited. For example, the lower limit of the thickness may be about 1, 5, 10, 15, 20, 25 or 30, and the upper limit may be about 5,000, 4,000, 3,000, 2,000, 1,000, 500, 200, 150, 100, 90, 80, 70, 60, 50, 40 or 30. The unit of the thickness is μm. The thickness is within a range that is less than or equal to any upper limit arbitrarily selected from the upper limits listed above; or within a range that is greater than or equal to any lower limit arbitrarily selected from the lower limits listed above. Or, it may be within a range that is equal to or greater than any lower limit arbitrarily selected from the lower limits listed above and equal to or less than any upper limit arbitrarily selected from the upper limits listed above.

[0045] For example, the lower limit of the thickness of the outer shell forming the case may be about 10 μm or 100 μm, and the upper limit may be about 500 μm or 200 μm. The thickness may be within a range that is less than or equal to any upper limit arbitrarily selected from the upper limits listed above; or within a range that is greater than or equal to any lower limit arbitrarily selected from the lower limits listed above; or within a range that is greater than or equal to any lower limit arbitrarily selected from the lower limits listed above and less than or equal to any upper limit arbitrarily selected from the upper limits listed above.

[0046] For example, the lower limit of the thickness of the heat absorbing device may be about 1 mm or 2 mm, and the upper limit may be about 10 mm, 5 mm, or 3 mm. The thickness may be within a range that is less than or equal to any upper limit arbitrarily selected from the upper limits listed above; or within a range that is greater than or equal to any lower limit arbitrarily selected from the lower limits listed above; or within a range that is greater than or equal to any lower limit arbitrarily selected from the lower limits listed above and less than or equal to any upper limit arbitrarily selected from the upper limits listed above.

[0047] The above heat absorbing device may include additional components to enable the above operation to be performed more effectively.

[0048] For example, the heat absorbing device may additionally include a heat conductive layer. This heat conductive layer may be located at an appropriate location within the heat absorbing device, for example, the heat conductive layer may be located between the case and the composite material described below within the heat absorbing device.

[0049] Fig. 3 is an example of a case in which the heat-conducting layer (2001) is added to the heat-absorbing device of Fig. 2. The heat-conducting layer may be located between the case (1001) and the composite material as shown in Fig. 3, but is not limited thereto in terms of location. The heat-conducting layer may be located in other locations, such as inside the case, and the number of heat-conducting layers may be one or two or more.

[0050] The term thermally conductive layer refers to a layer having a thermal conductivity (at 20°C) within the range described below. The lower limit of the thermal conductivity (at 20°C) of the thermally conductive layer may be about 15, 18, 20, 50, 100, 150, 200, 250, 300, 350, or 400, and the upper limit may be about 2,000, 1,500, 1,000, 900, 800, 700, 600, 500, 400, 300, 200, 100, or 50. The thermal conductivity is within a range that is equal to or greater than any lower limit arbitrarily selected from the lower limits listed above; Or, it may be within a range that is equal to or greater than any lower limit arbitrarily selected from the lower limits listed above and equal to or less than any upper limit arbitrarily selected from the upper limits listed above. The unit of the thermal conductivity is W / m·K.

[0051] The type of thermally conductive layer is not particularly limited as long as it possesses the above-mentioned thermal conductivity. Typically, metal materials with excellent thermal conductivity can be used as thermally conductive layers. For example, layers made of metal materials such as aluminum, gold, pure silver, tungsten, copper, nickel, or platinum can be applied.

[0052] There is no special limitation on the thickness of the thermal conductive layer, and an appropriate thickness can be set in consideration of the specifications of the heat absorption device, etc. For example, the lower limit of the thickness of the thermal conductive layer may be about 1, 5, 10, 15, 50, 75, or 90, and the upper limit may be about 500, 400, 300, 200, 100, 50, 40, or 30. The unit of the thickness is μm. The thickness may be within a range that is equal to or greater than any lower limit arbitrarily selected from the lower limits listed above; or within a range that is equal to or greater than any lower limit arbitrarily selected from the lower limits listed above and equal to or less than any upper limit arbitrarily selected from the upper limits listed above.

[0053] As shown in Fig. 3, in some cases, heat generated in an abnormal state may not be uniformly applied to the heat absorber, but may be locally applied only to a certain area. However, in order for the volatile substances inside the heat absorber to quickly vaporize and achieve a high-pressure state, the heat in the abnormal state must be uniformly applied to the heat absorber. In the case where a heat conductive layer exists, even if the heat in the abnormal state is locally applied, the heat can be quickly and efficiently transferred to the entire heat absorber, thereby enabling the aforementioned extinguishing action of the heat absorber to occur quickly and efficiently.

[0054] The present specification discloses a composite material. Such composite material may be present in a sealed space of a case of the above-described heat absorbing device.

[0055] The term composite refers to a material comprising two or more components. While the material comprises at least two components, it may additionally comprise other components.

[0056] The above composite material may possess appropriate cushioning properties. Under ideal conditions, the heat absorber may be subjected to high temperatures and high pressures momentarily. If the heat absorber fails to adequately respond to such momentary high pressures, complete exhaustion of the material within the enclosed space may become difficult, and even if exhaustion occurs, the exhaustion rate may not be properly controlled. Accordingly, the composite material may be designed to possess appropriate cushioning properties.

[0057] The above composite material or heat absorbing device may exhibit suitable insulating and heat absorbing properties, and may also exhibit suitable thermal conductivity properties.

[0058] For example, the lower limit of the thermal conductivity of the composite or heat absorbing device may be about 20, 30, 40, 50, 75, 100, 150, 200, 250 or 300, and the upper limit may be about 500, 450, 400, 350, 300, 250, 200, 150 or 100. The unit of the thermal conductivity is mW / m K. The thermal conductivity may be within a range that is less than or equal to any one of the upper limits listed above; or within a range that is greater than or equal to any one of the lower limits listed above; or within a range that is greater than or equal to any one of the lower limits listed above and less than or equal to any one of the upper limits listed above. In one example, the thermal conductivity may be, but is not limited to, 200 mW / m·K to 300 mW / m·K.

[0059] For example, the lower limit of the thermal conductivity after drying the moisture of the composite or heat absorbing device may be about 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60 or 65, and the upper limit may be about 200, 150, 100, 95, 90, 85, 80, 75, 70, 65, 60, 55, 50, 45 or 40. The unit of the thermal conductivity is mW / m K. The thermal conductivity is within a range that is less than or equal to any one of the upper limits listed above; or within a range that is greater than or equal to any one of the lower limits listed above; Or it may be within a range that is equal to or greater than any one of the lower limits listed above and equal to or less than any one of the upper limits listed above. In one example, the thermal conductivity may be, but is not limited to, 40 mW / m·K to 60 mW / m·K.

[0060] In one embodiment, the heat absorbing device may have an absolute value of the thickness change rate △T according to the following equation 1 within a predetermined range.

[0061] [Formula 1]

[0062] △T (%) = [(t2-t1) / t1] Х 100

[0063] In Equation 1, t2 is the thickness of the heat absorber confirmed after maintaining the heat absorber at -30°C for 20 hours, and t1 is the thickness of the heat absorber confirmed at 25°C before maintaining the heat absorber at -30°C for 20 hours.

[0064] In another embodiment, the absolute value of the thickness change rate △T according to the above formula 1 may be within a predetermined range. When checking the △T of the composite, t1 and t2 of the above formula 1 are the thicknesses of the composite, and other conditions are the same.

[0065] The method for measuring △T of Equation 1 is described in Test Example 2 of this specification. The thicknesses t1 and t2 are each an average of the thicknesses measured at three arbitrary points of the composite material or heat absorbing device according to the contents described in Test Example 2.

[0066] In one example, the upper limit of the absolute value of the thickness change rate △T may be about 5%, 4.5%, 4%, 3.5%, 3%, 2.5%, 2%, 1.5%, 1%, 0.9%, 0.8%, 0.7%, or 0.6%, and the lower limit may be about 0%, 0.5%, 1%, 1.5%, 2%, or 2.5%. The △T may be within a range that is less than or equal to any one upper limit arbitrarily selected from the upper limits listed above; or within a range that is equal to or greater than any one lower limit arbitrarily selected from the lower limits listed above and less than or equal to any one upper limit arbitrarily selected from the upper limits listed above. The △T may be a positive or negative number.

[0067] In one example, the upper limit of the thickness change rate △T may be about 5%, 4.5%, 4%, 3.5%, 3%, 2.5%, 2%, 1.5%, 1%, 0.9%, 0.8%, 0.7%, 0.6%, 0.5%, 0.4%, 0.3%, 0.2%, 0.15%, or 0.1%, and the lower limit may be about -5%, -4.5%, -4%, -3.5%, -3%, -2.5%, -2%, -1.5%, -1%, -0.9%, -0.8%, -0.7%, -0.6%, -0.5%, -0.4%, -0.3%, -0.2%, -0.15%, -0.1%, or 0%. The above thickness change rate may be within a range that is less than or equal to an upper limit arbitrarily selected from the upper limits listed above; or within a range that is greater than or equal to an lower limit arbitrarily selected from the lower limits listed above and less than or equal to an upper limit arbitrarily selected from the upper limits listed above.

[0068] By ensuring that the thickness change rate of the composite or heat absorbing device is within the above range, for example, the composite or heat absorbing device can be prevented from causing damage to other components of the device. For example, if the thickness change rate is large when the temperature decreases in the environment in which the composite or heat absorbing device is applied, the stress generated by the expansion or contraction of the composite or heat absorbing device may adversely affect other adjacent devices.

[0069] The composite material or heat absorbing device may exhibit suitable insulating and heat absorbing properties. For example, it may exhibit a specific trend in a temperature-time graph confirmed under conditions of 700°C and 50 kPa of pressure. The method for confirming the temperature-time graph is described in Test Example 1 of this specification.

[0070] A composite material or heat absorbing device according to an embodiment may exhibit an inflection point in a certain region of the temperature-time graph.

[0071] For example, the composite material or heat absorbing device may exhibit a predetermined inflection point confirmation temperature in the temperature-time graph. For example, the lower limit of the inflection point confirmation temperature may be about 80°C, 85°C, or 90°C, and the upper limit may be about 500°C, 450°C, 400°C, 350°C, 300°C, 250°C, 200°C, 150°C, 140°C, 130°C, 120°C, 110°C, 105°C, or 100°C. The inflection point confirmation temperature may be within a range that is equal to or greater than any lower limit arbitrarily selected from the lower limits listed above; or within a range that is equal to or greater than any lower limit arbitrarily selected from the lower limits listed above and equal to or less than any upper limit arbitrarily selected from the upper limits listed above. Composites that satisfy the above conditions in the temperature-time graph have a slow rate of heat transfer to the back of the material, effective heat-blocking performance, and appropriate heat absorption performance, while the heat-absorbing solution is appropriately absorbed so that it does not leak out of the packaging (case), effectively responding to overheating, ignition, and explosion.

[0072] The above inflection point confirmation temperature is the temperature at the point where the inflection point appears in the temperature-time graph, and the inflection point is the temperature at the point where the direction of the bend in the temperature-time graph changes.

[0073] The composite material or heat absorbing device according to an embodiment of the present invention may indicate a predetermined time to reach 180°C in the temperature-time graph. The time to reach 180°C is the time required for a temperature of 180°C to be confirmed in the temperature-time graph.

[0074] For example, the lower limit of the time to reach 180°C may be about 30, 35, 40, 45, 50, or 55, and the upper limit may be about 1,000, 500, 450, 400, 350, 300, 250, 200, 150, 140, 130, 120, or 110. The time to reach 180°C may be within a range that is equal to or greater than any arbitrarily selected lower limit among the lower limits listed above; or within a range that is equal to or greater than any arbitrarily selected lower limit among the lower limits listed above and equal to or less than any arbitrarily selected upper limit among the upper limits listed above. The unit of the time to reach 180°C is seconds. When the time for reaching 180℃ of the above composite satisfies the above-mentioned range, the rate at which heat is transferred to the back of the heat-blocking material is sufficiently slow, the heat-blocking performance is effective, and it is easy to suppress the chain reaction of external ignition or heat generation.

[0075] The composite material according to one embodiment may include an inorganic gel and a volatile material.

[0076] The above composite material may include an inorganic gel.

[0077] These inorganic gels can stably maintain the volatile substances described below in the composite material under normal conditions, while effectively discharging them under abnormal conditions. Furthermore, the inorganic gels exhibit appropriate buffering, insulation, and heat-insulating properties, thereby enabling the composite material and heat-absorbing device to effectively respond to abnormal conditions.

[0078] The above characteristics can be secured by controlling the material of the inorganic gel and the degree and form of gelation.

[0079] The above-mentioned inorganic gel may be, for example, an oxide network formed by a so-called sol-gel process. This oxide network may include a network in which inorganic elements are connected via oxygen atoms. As the inorganic elements, one or more selected from the group consisting of silicon, titanium, zirconium, niobium, tantalum, molybdenum, and tungsten may be exemplified. For example, if the inorganic element is silicon, the inorganic gel may be called silica gel.

[0080] Since the inorganic gel disclosed herein can stably contain and maintain a large amount of moisture, a composite material using the inorganic gel can maintain dimensional stability against external pressure compared to packs that simply contain moisture, and can prevent unnecessary excessive release of fire extinguishing solution in the event of ignition. Furthermore, after all the heat absorbents within the composite have vaporized and the latent heat has been consumed, the remaining inorganic network structure exhibits low porosity, thereby exhibiting an additional insulating effect.

[0081] The specific type of the above-mentioned inorganic gel is not particularly limited, as long as it can appropriately perform the above-mentioned function. In one example, the above-mentioned inorganic gel may be silica gel, which can more effectively achieve the desired effect.

[0082] The content of the above-mentioned inorganic gel can be appropriately controlled depending on the purpose. For example, the lower limit of the content of the above-mentioned inorganic gel based on the total weight of the composite material may be about 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, or 3.2 wt%, and the upper limit may be about 20 wt%, 15 wt%, 10 wt%, 8 wt%, 6 wt%, or 4 wt%. The above-mentioned ratio may be within a range that is less than or equal to any upper limit arbitrarily selected from the above-mentioned upper limits and greater than or equal to any lower limit arbitrarily selected from the above-mentioned lower limits.

[0083] In another example, the lower limit of the content of the inorganic gel relative to 100 parts by weight of the volatile material may be about 0.001 parts by weight, 0.005 parts by weight, 0.01 parts by weight, 0.05 parts by weight, 0.1 parts by weight, 0.15 parts by weight, 0.2 parts by weight, 0.25 parts by weight, 0.3 parts by weight, 0.5 parts by weight, 1 part by weight, 3 parts by weight or 5 parts by weight, and the upper limit may be about 100 parts by weight, 95 parts by weight, 90 parts by weight, 85 parts by weight, 80 parts by weight, 75 parts by weight, 70 parts by weight, 65 parts by weight, 60 parts by weight, 55 parts by weight, 50 parts by weight, 45 parts by weight, 40 parts by weight, 35 parts by weight, 30 parts by weight, 25 parts by weight, 20 parts by weight, 15 parts by weight, 10 parts by weight, It can be about 5 parts by weight, 4 parts by weight, or 3 parts by weight. The ratio can be within a range that is less than or equal to any upper limit arbitrarily selected from the upper limits listed above; or within a range that is equal to or greater than any lower limit arbitrarily selected from the lower limits listed above; or within a range that is equal to or greater than any lower limit arbitrarily selected from the lower limits listed above and less than or equal to any upper limit arbitrarily selected from the upper limits listed above.

[0084] The shape of the inorganic gel can be controlled to effectively achieve the desired effect. After the internal heat absorbent of the composite material is completely vaporized and the latent heat is consumed, the remaining network exhibits low porosity, thereby providing additional insulation.

[0085] The above composite material may include a vaporizable material. The term "vaporizable material" refers to a material that vaporizes at a given temperature. Such a vaporizable material may exist in a liquid state at room temperature (25°C). Such a vaporizable material may be used to reduce heat through heat exchange or the like when heat generation, ignition, and / or explosion occurs in an abnormal state in an object adjacent to the heat absorbing device, or to eliminate flames generated by the ignition and / or explosion. Such a vaporizable material may rapidly vaporize in the abnormal state, thereby increasing the pressure in the enclosed space, opening the vent area, and discharging to the outside through the opened vent area.

[0086] As the above-mentioned volatile substance, any substance that can be vaporized and is non-flammable may be used without any special restrictions. For example, the above-mentioned volatile substance may be a solvent having a freezing point and / or boiling point within a certain range.

[0087] For example, the lower limit of the freezing point of the volatile substance may be about -50°C, -40°C, -30°C, -20°C, -10°C, -5°C, -4°C, -3°C, -2°C, -1°C or 0°C, and the upper limit may be about 10°C, 9°C, 8°C, 7°C, 6°C, 5°C, 4°C, 3°C or 2°C. The freezing point may be within a range that is less than or equal to any upper limit arbitrarily selected from the upper limits listed above; or within a range that is greater than or equal to any lower limit arbitrarily selected from the lower limits listed above; or within a range that is greater than or equal to any lower limit arbitrarily selected from the lower limits listed above and less than or equal to any upper limit arbitrarily selected from the upper limits listed above. The freezing point is a freezing point under 1 atm.

[0088] In order for the above-mentioned volatile substance to effectively respond to the above-mentioned heat generation, ignition and / or explosion, it may be advantageous for the above-mentioned volatile substance to be vaporized at least by the heat generated by the above-mentioned heat generation, ignition and explosion, and for this purpose, the boiling point of the above-mentioned volatile substance may be controlled.

[0089] The lower limit of the boiling point of the above-mentioned volatile substance may be about 80°C, 85°C, 90°C, or 95°C, and the upper limit may be about 200°C, 180°C, 160°C, 140°C, 120°C, 115°C, 110°C, or 105°C. The boiling point may be within a range that is less than or equal to any upper limit arbitrarily selected from the upper limits listed above; or within a range that is greater than or equal to any lower limit arbitrarily selected from the lower limits listed above; or within a range that is greater than or equal to any lower limit arbitrarily selected from the lower limits listed above and less than or equal to any upper limit arbitrarily selected from the upper limits listed above. The boiling point is a boiling point under 1 atm.

[0090] As a volatile substance, any suitable type can be selected and used without special restrictions as long as it has a freezing point and / or boiling point within the above range and is non-flammable. Representative examples of such volatile substances include water, glycerol, mineral oil, oligosaccharides, silicone oils such as polydimethylsiloxane, glycols such as toluene, dimethyl sulfoxide, and polyethylene glycol. Accordingly, water can be used as the volatile substance, but the types of applicable volatile substances are not limited to the above. Specifically, water can be used as the volatile substance.

[0091] In one example, the volatile material may be used as a solvent for an ionic compound. That is, the ionic compound may be mixed with the volatile material to form an ionic compound solution, and the composite may include a structure in which the solution is impregnated into inorganic fibers.

[0092] The lower limit of the ratio of the above-mentioned volatile material may be, for example, about 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt%, 60 wt% or 65 wt% based on 100 wt% of the composite material, and the upper limit may be about 95 wt%, 90 wt%, 85 wt%, 80 wt%, 75 wt%, 70 wt%, 65 wt%, 60 wt%, 55 wt%, 50 wt%, 45 wt% or 40 wt%. The ratio is within a range that is equal to or greater than any one lower limit arbitrarily selected from among the lower limits listed above; Or, it may be within a range that is equal to or greater than any lower limit arbitrarily selected from the lower limits listed above and equal to or less than any upper limit arbitrarily selected from the upper limits listed above. The above-described heat absorption can be achieved by adjusting the content of the volatile substance. If the volatile substance is not sufficiently included in the composite, there is a problem that the thermal runaway blocking performance is significantly reduced.

[0093] The above composite may include an ionic compound.

[0094] These ionic compounds may be derived from a substance added to adjust the freezing point of the composite, a substance added as a polymerization catalyst for forming the inorganic gel, and / or a substance added to form polymerization conditions that cause the inorganic gel to exhibit desired properties.

[0095] For example, a composite including an inorganic gel formed under polymerization conditions formed by the addition of the ionic compound may exhibit appropriate buffering properties. In addition, the mobility of the vaporizable material molecules adjusted by the addition of the ionic compound may enable the vaporizable material to exhibit an appropriate vaporization rate in the above-described state. In addition, the freezing point of the composite adjusted by the addition of the ionic compound may suppress expansion of the vaporizable material at low temperatures, thereby solving problems such as a decrease in stability due to an increase in internal pressure caused by an increase in the thickness of the composite, and / or a decrease in stability due to an increase in pressure caused by unnecessary vapor generation and subsequent volume expansion at high temperatures.

[0096] Ionic compounds can be used that have a certain level of solubility in the above-mentioned volatile substances or water. The degree of freedom in selecting an ionic compound with an appropriate solubility increases with the amount of the ionic compound added. Accordingly, an amount that secures the desired freezing point can be selected without impairing the fire extinguishing function and while improving it.

[0097] The lower limit of the solubility of the above ionic compound in water 100 at 0℃ may be about 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, 185, 190, 195, 200, 205, 210 or 215, and the upper limit may be about 1000, 900, 800, 700, 600, 500, It can be 400, 300, 250, 245, 240, 235, 230, 225, 220, 215, 210, 205, 200, 195, 190, 185, 180, 175, 170, 165, 160, 155, 150, 145, 140, 135, 130, 125, 120, 115, 110, 105, 100, 95, 90, 85, 80, 75, 70, 65, 60, 55, 50, 45, 40, 35, or 30. The solubility may be within a range that is less than or equal to any one of the upper limits arbitrarily selected from the upper limits listed above; or within a range that is greater than or equal to any one of the lower limits arbitrarily selected from the lower limits listed above; or within a range that is greater than or equal to any one of the lower limits arbitrarily selected from the lower limits listed above and less than or equal to any one of the upper limits listed above. The solubility is the weight of an ionic compound that can be maximally dissolved in 100 g of water at 0°C, and the unit of the solubility is g. The solubility may be defined as the amount of a sample that can be maximally dissolved in 100 g of water at 0°C according to ASTM E1148-02.

[0098] The lower limit of solubility of the above ionic compound in 100 g of water at 25°C is 70, 75, 80, 85, 90, 95, 100, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, 185, 190, 195, 200, 205, 210, 215, 225, 230, 235, 240, 255, 260, 265, 270, 275, 280, 285, 290, 295, 300, 305, It can be around 310, 315 or 320, and its upper limit is 1000, 900, 800, 700, 600, 500, 400, 350, 345, 340, 335, 330, 325, 320, 315, 310, 305, 300, 295, 290, 280, 275, 270, 265, 260, 255, 250, 245, 240, 235, 230, 225, 220, 215, 210, 205, 200, 195, 190, 185, 180, 175, 170, 165, It can be about 160, 155, 150, 145, 140, 135, 130, 125, 120, 115, 110, 105 or 100. The solubility can be within a range that is less than or equal to any upper limit arbitrarily selected from the upper limits listed above; or within a range that is greater than or equal to any lower limit arbitrarily selected from the lower limits listed above; or within a range that is greater than or equal to any lower limit arbitrarily selected from the lower limits listed above and less than or equal to any upper limit arbitrarily selected from the upper limits listed above. The solubility is the weight of an ionic compound that can be maximally dissolved in 100 g of water at 25°C, and the unit of the solubility is g. The solubility can be defined as the amount of a sample that can be maximally dissolved in 100 g of water at 25°C according to ASTM E1148-02.

[0099] The category of ionic compounds mentioned above includes substances that are ionic in themselves or can produce ions, such as salts.

[0100] In one example, the ionic compound may be exemplified by at least one selected from the group consisting of potassium salts, sodium salts, magnesium salts, and ammonium salts. The ionic compound may be at least one selected from the group consisting of formic acid, acetate, carbonate, and / or sulfate. Specific examples of the ionic compound include at least one selected from the group consisting of sodium acetate (CH3COONa), sodium formate (HCOONa), potassium acetate (CH3COOK), potassium formate (HCOOK), calcium formate ((HCOO)2Ca), magnesium formate ((HCOO)2Mg), potassium carbonate (K2CO3), and ammonium sulfate ((NH4)2SO4).

[0101] In another example, the ionic compound may be an acid and / or base added as a catalyst for the polymerization described below.

[0102] For example, a potassium-based salt or an ammonium-based salt may be used as the ionic compound. In this case, the ionic compound may include one or more selected from the group consisting of potassium acetate, potassium formate, potassium chloride, potassium hydroxide, ammonium carbonate, and ammonium sulfate.

[0103] Ionic compounds have the following formula 2 △T f can be included so that it is within a certain range. △T in Equation 2 below f is a value reflecting the degree of freezing point adjustment that can be achieved by adding the ionic compound, and this value can be adjusted within a range that ensures the above-described effects, i.e., appropriate adjustment of the mobility of the vaporizable substance molecules, formation of the inorganic gel of the desired network, and stability at high or low temperatures.

[0104] [Formula 2]

[0105] △T f = K f ХMХI

[0106] K in Equation 2 f is the freezing point depression constant of the volatile substance, M is the molal concentration of the ionic compound with respect to the volatile substance, and I is the number of moles of ions produced by complete dissociation of 1 mole of the ionic compound.

[0107] K in Equation 2 f is the freezing point depression constant of a volatile substance, and its unit is K / m or K / ℃. For example, if the volatile substance is water, the above K f is 1.86.

[0108] M in Equation 2 is the molal concentration of the ionic compound, which is the molal concentration relative to the volatile substance. Therefore, M is the number of moles of the ionic compound present per 1 kg of the volatile substance in the composite.

[0109] I in Equation 2 is the number of ions (moles) formed by 1 mole of the ionic compound when the ionic compound is dissociated, and in this case, dissociation means a state in which the ionic compound is completely dissociated.

[0110] △T in Equation 2 f The lower limit of may be, for example, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22 or 23, and the upper limit may be, for example, 50, 45, 40, 35, 30, 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12 or 11. The above △T fIt may be within a range that is greater than or equal to any one of the lower limits arbitrarily selected from the lower limits listed above; or within a range that is less than or equal to any one of the upper limits arbitrarily selected from the upper limits listed above; or within a range that is greater than or equal to any one of the lower limits arbitrarily selected from the lower limits listed above and less than or equal to any one of the upper limits arbitrarily selected from the upper limits listed above. △T in Equation 2 f The unit is ℃. Within the above range, the desired effects, such as appropriate adjustment of the mobility of the vaporizable material molecules, formation of an inorganic gel of the desired network, and securing stability at high or low temperatures, can be obtained.

[0111] The above ionic compound can exhibit a boiling point or decomposition temperature within a predetermined range. Through this, the above appropriate heat absorption performance and heat blocking performance can be realized.

[0112] In one example, the lower limit of the boiling point or decomposition temperature of the ionic compound may be 300°C, 320°C, 340°C, 360°C, 380°C, 400°C, 420°C, 440°C, 460°C, 480°C or 500°C, and the upper limit may be 1500°C, 1450°C, 1400°C, 1350°C, 1300°C, 1250°C, 1200°C, 1150°C, 1100°C, 1050°C or 1000°C. The range may be within a range that is less than or equal to any upper limit arbitrarily selected from the upper limits listed above; or within a range that is equal to or greater than any lower limit arbitrarily selected from the lower limits listed above; Or, it may be within a range that is equal to or greater than any lower limit arbitrarily selected from the lower limits listed above and equal to or less than any upper limit arbitrarily selected from the upper limits listed above.

[0113] The above composite may include inorganic fibers. These inorganic fibers may serve to enable the composite to exhibit the aforementioned cushioning properties and, in some cases, to support some or all of the components, such as the volatile substances, described above.

[0114] As inorganic fibers, for example, inorganic fibers commonly used in the formation of insulating materials can be used, such as so-called glass fibers and / or ceramic fibers, fibers mixed with high and low molecules, etc. Such inorganic fibers can exist in the form of, for example, woven or nonwoven fabrics or paper. The category of woven or nonwoven fabrics may also include objects referred to as wool or blankets.

[0115] For example, as the inorganic fiber, ceramic paper, ceramic paper using an organic / inorganic binder, binder-free fiber, ceramic fiber, glass fiber, glass felt, basalt fiber, basalt felt, aramid fabric, silica felt, oxpan carbon felt, carbon fiber felt, and / or melamine fiber can be used, and an organic binder can be used. When the inorganic fiber is used, the insulation property is excellent, and the sol is easily absorbed, so that materials such as gels and heat absorbents can be evenly positioned within the substrate, thereby increasing stability.

[0116] The properties of the above inorganic fibers can be adjusted according to the purpose.

[0117] For example, the lower limit of the tensile strength of the inorganic fiber may be about 0.01 MPa, 0.05 MPa, or 0.1 MPa, and the upper limit may be about 10 MPa, 9 MPa, 8 MPa, 7 MPa, 6 MPa, 5 MPa, 4 MPa, 3 MPa, 2 MPa, 1 MPa, or 0.5 MPa. The tensile strength may be within a range that is less than or equal to any upper limit arbitrarily selected from the upper limits listed above; or within a range that is equal to or greater than any lower limit arbitrarily selected from the lower limits listed above; or within a range that is equal to or greater than any lower limit arbitrarily selected from the lower limits listed above and less than or equal to any upper limit arbitrarily selected from the upper limits listed above.

[0118] For example, the lower limit of the compressive strength of the inorganic fiber may be about 1 kPa, 5 kPa, 10 kPa, 50 kPa, 100 kPa, or 150 kPa, and the upper limit may be about 1,000 kPa, 900 kPa, 800 kPa, 700 kPa, 600 kPa, 500 kPa, 400 kPa, 300 kPa, or 200 kPa. The compressive strength may be within a range that is less than or equal to any upper limit arbitrarily selected from the upper limits listed above; or within a range that is greater than or equal to any lower limit arbitrarily selected from the lower limits listed above; or within a range that is greater than or equal to any lower limit arbitrarily selected from the lower limits listed above and less than or equal to any upper limit arbitrarily selected from the upper limits listed above. At this time, the compressive strength may be measured as the compressive strength when compressed to 50% of the initial thickness of the inorganic fiber.

[0119] For example, the lower limit of the Young's modulus of the inorganic fiber may be about 0.1 MPa, 0.5 MPa, 1 MPa, 1.5 MPa, 2 MPa, 2.5 MPa, or 3 MPa, and the upper limit may be about 20 MPa, 18 MPa, 16 MPa, 14 MPa, 12 MPa, 10 MPa, 8 MPa, 6 MPa, or 4 MPa. The Young's modulus may be within a range that is less than or equal to any upper limit arbitrarily selected from the upper limits listed above; or within a range that is equal to or greater than any lower limit arbitrarily selected from the lower limits listed above; or within a range that is equal to or greater than any lower limit arbitrarily selected from the lower limits listed above and less than or equal to any upper limit arbitrarily selected from the upper limits listed above.

[0120] The inorganic fibers, when included in the composite, may exhibit one or more of the tensile strength, compressive strength, and Young's modulus within the above range. Thus, for example, if the inorganic fibers are included in the composite in the form of the woven or nonwoven fabric, the woven or nonwoven fabric may exhibit one or more of the tensile strength, compressive strength, and Young's modulus within the above range. The tensile strength, compressive strength, and Young's modulus may be measured according to the KS K ISO 9073-3 standard.

[0121] It is possible to form a composite having the desired properties by applying inorganic fibers exhibiting tensile strength, compressive strength and / or Young's modulus in the above range.

[0122] The lower limit of the density of the above-mentioned inorganic fiber may be about 0.01, 0.05, or 0.1, and the upper limit may be about 10, 8, 6, 4, 2, 1, 0.5, or 0.3. The density may be within a range that is less than or equal to any upper limit arbitrarily selected from the upper limits listed above; or within a range that is greater than or equal to any lower limit arbitrarily selected from the lower limits listed above; or within a range that is greater than or equal to any lower limit arbitrarily selected from the lower limits listed above and less than or equal to any upper limit arbitrarily selected from the upper limits listed above. The unit of the density is g / cm 3 am.

[0123] The inorganic fibers, when included in the composite, can exhibit a density within the above range. Thus, for example, if the inorganic fibers are included in the composite in the form of a woven or nonwoven fabric, the woven or nonwoven fabric can exhibit the above density.

[0124] When the above-mentioned inorganic fiber is included in the form of a woven fabric or a non-woven fabric, the thickness of the woven fabric or the non-woven fabric may be selected within a range capable of exhibiting the above-described characteristics. For example, the lower limit of the thickness may be about 0.01, 0.05, 0.1, 0.5, 1, 1.5, 2, 2.5, or 3, and the upper limit may be about 100, 50, 30, 10, 8, 6, or 4. The thickness may be within a range that is less than or equal to any upper limit arbitrarily selected from the upper limits listed above; or within a range that is greater than or equal to any lower limit arbitrarily selected from the lower limits listed above; or within a range that is greater than or equal to any lower limit arbitrarily selected from the lower limits listed above and less than or equal to any upper limit arbitrarily selected from the upper limits listed above. The unit of the thickness is mm.

[0125] The above-mentioned inorganic fibers may be present in the composite material in an appropriate ratio. For example, the lower limit of the weight ratio of the inorganic fiber to 100 parts by weight of the volatile material may be about 0.5 parts by weight, 1 part by weight, 5 parts by weight, 7 parts by weight, 7.5 parts by weight, 8 parts by weight, 8.5 parts by weight, 10 parts by weight, 20 parts by weight, or 25 parts by weight, and the upper limit may be about 200 parts by weight, 180 parts by weight, 160 parts by weight, 140 parts by weight, 120 parts by weight, 100 parts by weight, 95 parts by weight, 90 parts by weight, 85 parts by weight, 80 parts by weight, 75 parts by weight, 70 parts by weight, 65 parts by weight, 60 parts by weight, 55 parts by weight, 50 parts by weight, 45 parts by weight, 40 parts by weight, 35 parts by weight, 30 parts by weight, 25 parts by weight, or 20 parts by weight. The above ratio may be within a range that is less than or equal to any one of the upper limits arbitrarily selected from the upper limits listed above; or within a range that is greater than or equal to any one of the lower limits arbitrarily selected from the lower limits listed above; or within a range that is greater than or equal to any one of the lower limits arbitrarily selected from the lower limits listed above and less than or equal to any one of the upper limits arbitrarily selected from the upper limits listed above.

[0126] In another example, the lower limit of the content of the inorganic fiber based on 100 wt% of the composite may be about 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt% or 12 wt%, and the upper limit may be about 30 wt%, 25 wt%, 20 wt%, 18 wt%, 17 wt%, 16 wt%, 15 wt%, 14 wt%, 13 wt% or 12 wt%. The ratio may be within a range that is less than or equal to any one upper limit arbitrarily selected from the upper limits listed above; or within a range that is greater than or equal to any one lower limit arbitrarily selected from the lower limits listed above. Or, it may be within a range that is equal to or greater than any lower limit arbitrarily selected from the lower limits listed above and equal to or less than any upper limit arbitrarily selected from the upper limits listed above.

[0127] When the above-described inorganic fibers and inorganic gel exist simultaneously, the inorganic gel may be attached to the inorganic fibers, or the inorganic gel and the inorganic fibers may exist in a state of being entangled with each other. For example, as described below, the above-described structure can be realized by performing the gelation process in the presence of the inorganic fibers, thereby allowing the composite to exhibit desired properties and perform the desired function more effectively.

[0128] The above composite material includes the above components and may include additional components if necessary.

[0129] Additionally, the composite material that may be present within the case of the heat absorbing device may exhibit a certain level of peel strength or higher relative to the case. Such a composite material may provide excellent packaging strength characteristics for the heat absorbing device and may also provide advantageous results during transport of the heat absorbing device.

[0130] The above composite material may have a moisture content W within a predetermined range as analyzed according to Equation 3 below.

[0131] [Formula 3]

[0132] W(%) = [(ab) / a] Х 100

[0133] In Equation 3, b is the weight measured after drying the composite at a temperature of 150°C for 24 hours, and a is the weight of the composite before drying it at a temperature of 150°C for 24 hours. The drying can be performed using, for example, a convection oven.

[0134] The moisture content according to Equation 3 represents the moisture content contained within the composite, representing the ratio of the weight of moisture to the total weight of the composite. This can be calculated from the amount of evaporated moisture, determined by comparing the weight before drying and the weight loss after drying the composite at 150°C for 24 hours, using Equation 3.

[0135] The lower limit of the moisture content according to the above formula 3 may be about 50 wt%, 60 wt%, or 65 wt%, and the upper limit may be about 95 wt%, 90 wt%, or 85 wt%. The ratio may be within a range that is equal to or greater than any arbitrarily selected lower limit among the lower limits listed above; or within a range that is equal to or greater than any arbitrarily selected lower limit among the lower limits listed above and equal to or less than any arbitrarily selected upper limit among the upper limits listed above.

[0136] The present specification discloses a method for producing the above composite material or inorganic gel.

[0137] For example, the method for producing the above-mentioned inorganic gel includes a step of polymerizing a precursor solution containing an inorganic gel precursor and a vaporizable material.

[0138] The polymerization described above is a process in which relatively low-molecular-weight substances, such as monomers or oligomers, form chains or networks to form high-molecular-weight components. In this case, the monomer or oligomer may be the precursor. Furthermore, there are no particular limitations on the specific method by which the polymerization is performed. For example, if the inorganic gel precursor is a condensation precursor described below, the polymerization process may be a so-called sol-gel process.

[0139] The composition of the precursor solution can be adjusted to form the desired inorganic gel and composite.

[0140] As the precursor, for example, a metal alkoxide can be used. This precursor is a condensation precursor and can form an inorganic gel through the sol-gel process. Specifically, as the metal alkoxide, one or more alkoxides selected from the group consisting of silicon, titanium, zirconium, niobium, tantalum, molybdenum, and tungsten can be exemplified. The lower limit of the number of carbon atoms present in the alkoxide can be about 4, 6, 8, or 10, and the upper limit can be about 20, 18, 16, 14, 12, 10, or 8. The above carbon number may be within a range that is equal to or greater than any lower limit arbitrarily selected from the lower limits listed above, and equal to or less than any upper limit arbitrarily selected from the upper limits listed above.

[0141] As the precursor, for example, a component called sodium silicate may be used, and this component can form silica gel as an inorganic gel.

[0142] As the above-mentioned volatile material, components such as water described above can be used.

[0143] The composition of the precursor solution can be adjusted to form the desired inorganic gel and composite.

[0144] For example, the content of the vaporizable substance in the precursor solution can be adjusted. For example, the lower limit of the content of the vaporizable substance in the precursor solution can be about 30 wt%, 40 wt%, 50 wt%, 60 wt%, or 70 wt%, and the upper limit can be about 95 wt%, 90 wt%, 85 wt%, 80 wt%, 75 wt%, 70 wt%, 65 wt%, or 60 wt%. The content can be within a range that is equal to or greater than any lower limit arbitrarily selected from the lower limits listed above, and equal to or less than any upper limit arbitrarily selected from the upper limits listed above.

[0145] The lower limit of the weight ratio of the precursor to 100 parts by weight of the vaporizable substance in the precursor solution may be about 3 parts by weight, 5 parts by weight, 7 parts by weight, 10 parts by weight, 15 parts by weight, or 20 parts by weight, and the upper limit may be about 100 parts by weight, 90 parts by weight, 80 parts by weight, 70 parts by weight, 60 parts by weight, 50 parts by weight, 40 parts by weight, 30 parts by weight, 25 parts by weight, 20 parts by weight, 15 parts by weight, or 10 parts by weight. The content may be within a range that is equal to or greater than any lower limit arbitrarily selected from the lower limits listed above, and is equal to or less than any upper limit arbitrarily selected from the upper limits listed above.

[0146] The above-described precursor solution may be formulated to exhibit a pH within a predetermined range. For example, the lower limit of the pH of the above-described precursor solution may be about 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, or 7, and the upper limit may be about 14, 13, 12, 11, 10, 9, 8, or 7. The pH may be within a range that is equal to or greater than any lower limit arbitrarily selected from the above-described lower limits and equal to or less than any upper limit arbitrarily selected from the above-described upper limits.

[0147] To adjust the pH, the precursor solution may additionally contain a catalyst. This catalyst may be an ionic compound. There is no particular limitation on the type of applicable catalyst, and for example, an acid catalyst or a base catalyst applicable to a general sol-gel process may be used. Examples of such acid catalysts include one or a mixture of two or more selected from hydrochloric acid, sulfuric acid, fluorosulfuric acid, nitric acid, phosphoric acid, acetic acid, hexafluorophosphoric acid, p-toluenesulfonic acid, and trifluoromethanesulfonic acid, and examples of base catalysts include, but are not limited to, alkaline catalysts such as sodium hydroxide, ammonium hydroxide, or ammonium chloride.

[0148] The content of the catalyst can be controlled within a range where the above-mentioned pH can be achieved. For example, the lower limit of the molal concentration of the catalyst (i.e., the number of moles of catalyst present per 1 kg of the vaporizable substance) based on the vaporizable substance in the precursor solution may be about 0.05, 0.1, 0.5, 1, or 1.5, and the upper limit may be about 5, 4.5, 4, 3.5, 3, 2.5, 2, or 1.5. The molal concentration may be within a range that is equal to or greater than any lower limit arbitrarily selected from the lower limits listed above and equal to or less than any upper limit arbitrarily selected from the upper limits listed above.

[0149] The above-mentioned precursor solution may additionally contain an ionic compound in addition to the catalyst. This ionic compound may be added to adjust the molecular energy of the vaporizable substance and thereby its mobility. Examples of the ionic compound include the aforementioned potassium salts, sodium salts, magnesium salts, and / or ammonium salts.

[0150] The content of all ionic compounds present in the precursor solution, including the catalyst, can be adjusted. Adjusting this content controls the fluidity of the vaporizable material, and this controlled fluidity can affect the polymerization efficiency of the precursor, thereby forming the desired inorganic gel at a specified polymerization temperature.

[0151] For example, the ionic compound has △T of the above-mentioned formula 2 f can be added so that it is within a certain range. In this case, K in Equation 2 f is the freezing point depression constant of the vaporizable substance in the above-mentioned precursor solution, M is the molal concentration of the ionic compound with respect to the vaporizable substance in the above-mentioned precursor solution, and I is the number of moles of ions generated by complete dissociation of 1 mole of the ionic compound.

[0152] △T of Equation 2 in the bulb solution f The lower limit of may be, for example, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22 or 23, and the upper limit may be, for example, 50, 45, 40, 35, 30, 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12 or 11. The above △T fIt may be within a range that is greater than or equal to any one of the lower limits arbitrarily selected from the lower limits listed above; or within a range that is less than or equal to any one of the upper limits arbitrarily selected from the upper limits listed above; or within a range that is greater than or equal to any one of the lower limits arbitrarily selected from the lower limits listed above and less than or equal to any one of the upper limits arbitrarily selected from the upper limits listed above. △T of the above formula 2 f The unit is ℃. Within the above range, the desired effects, such as appropriate adjustment of the mobility of the vaporizable material molecules, formation of an inorganic gel of the desired network, and securing stability at high or low temperatures, can be obtained.

[0153] The bulb solution may contain any necessary ingredients in addition to the above ingredients.

[0154] For example, the polymerization of the precursor solution may be performed in the presence of the inorganic fibers. The inorganic fibers also affect the polymerization efficiency of the precursor. In such a case, the precursor solution may include the inorganic fibers described above.

[0155] The lower limit of the weight ratio of the inorganic fiber to 100 parts by weight of the volatile material in the bulb solution may be about 5 parts by weight, 10 parts by weight, 15 parts by weight, 20 parts by weight, or 25 parts by weight, and the upper limit may be about 100 parts by weight, 90 parts by weight, 80 parts by weight, 70 parts by weight, 60 parts by weight, 50 parts by weight, 40 parts by weight, 30 parts by weight, or 25 parts by weight. The weight ratio may be within a range that is equal to or greater than any lower limit arbitrarily selected from the lower limits listed above, while at the same time being less than or equal to any upper limit arbitrarily selected from the upper limits listed above.

[0156] The temperature for polymerization of the above-mentioned bulb solution can be controlled. This controlled temperature is the above-mentioned △T fIt contributes to the formation of an inorganic gel of the desired shape by linking with an ionic compound having a value of .

[0157] For example, the lower limit of the polymerization temperature may be about 10°C, 15°C, 20°C, 25°C, 30°C, or 35°C, and the upper limit may be about 50°C, 45°C, 40°C, 35°C, 30°C, or 25°C. The polymerization temperature may be within a range that is equal to or greater than any arbitrarily selected lower limit among the lower limits listed above, while being less than or equal to any arbitrarily selected upper limit among the upper limits listed above.

[0158] In order to form the desired inorganic gel and composite, the polymerization may be carried out in multiple stages. For example, the manufacturing method may include a first stage (primary polymerization) of polymerizing the precursor solution to obtain a prepolymer, and a second stage (secondary polymerization) of polymerizing the precursor or prepolymer in the presence of the inorganic fiber to obtain an inorganic gel. The precursor solution applied to the first polymerization may not include the inorganic fiber. That is, the first polymerization is performed in the absence of the inorganic fiber, and the second polymerization of the second stage may be performed in the presence of the inorganic fiber. That is, after the first polymerization, the polymer may be mixed with the inorganic fiber, and further polymerization may be performed. The precursor of the second stage may refer to a precursor that did not participate in the polymerization during the first polymerization to form the prepolymer.

[0159] The polymerization temperature, polymerization time, and / or mixing conditions of the first step may be adjusted.

[0160] The lower limit of the polymerization temperature of the first step may be about 10°C, 15°C, 20°C, 25°C, 30°C, or 35°C, and the upper limit may be about 50°C, 45°C, 40°C, 35°C, 30°C, or 25°C. The polymerization temperature may be within a range that is equal to or greater than any lower limit arbitrarily selected from the lower limits listed above, while being less than or equal to any upper limit arbitrarily selected from the upper limits listed above.

[0161] The above first step can be performed while stirring the precursor solution at an appropriate speed. In this process, the lower limit of the stirring speed can be about 100 rpm, 150 rpm, 200 rpm, 250 rpm, 300 rpm, 350 rpm, 400 rpm, 450 rpm, or 500 rpm, and the upper limit can be about 2,000 rpm, 1,500 rpm, 1,000 rpm, 800 rpm, 600 rpm, 400 rpm, or 300 rpm. The stirring speed can be within a range that is equal to or greater than any lower limit arbitrarily selected from the lower limits listed above and equal to or less than any upper limit arbitrarily selected from the upper limits listed above.

[0162] The lower limit of the time for performing the above first polymerization may be about 1 second, 5 seconds, 10 seconds, 30 seconds, 1 minute, 5 minutes, 10 minutes, or 15 minutes, and the upper limit may be about 60 minutes, 55 minutes, 50 minutes, 45 minutes, 40 minutes, 35 minutes, 30 minutes, 25 minutes, 20 minutes, 15 minutes, 10 minutes, 8 minutes, 6 minutes, 4 minutes, 2 minutes, 1 minute, or 30 seconds. The time may be within a range that is equal to or greater than any lower limit arbitrarily selected from the lower limits listed above and equal to or less than any upper limit arbitrarily selected from the upper limits listed above.

[0163] By forming a primary polymer (a prepolymer or a mixture of a prepolymer and a precursor) under the above conditions and performing secondary polymerization, the desired composite material can be formed.

[0164] The above primary polymer can be further polymerized secondaryally to form an inorganic gel. As described above, the secondary polymerization can be performed in the presence of the inorganic fibers. That is, after the primary polymerization, the inorganic fibers and the primary polymer are mixed so as to satisfy the ratio described above (ratio of inorganic fibers to 100 parts by weight of the volatile material), and then further polymerization is performed to effectively form the desired inorganic gel.

[0165] The above secondary polymerization can be performed at an appropriate temperature.

[0166] For example, the lower limit of the polymerization temperature may be about 10°C, 15°C, 20°C, or 25°C, and the upper limit may be about 40°C, 35°C, 30°C, or 25°C. The temperature may be within a range that is equal to or greater than any lower limit arbitrarily selected from the lower limits listed above and equal to or less than any upper limit arbitrarily selected from the upper limits listed above.

[0167] By maintaining the mixture of the primary polymer and the inorganic fiber at the above temperature during the secondary polymerization, the desired inorganic gel can be obtained.

[0168] The composite can be prepared by mixing the inorganic gel formed in this manner with other components of the required composite, such as the aforementioned ionic compounds, opacifiers (e.g., TiO2, Fe2O3, and / or SiC, etc.) and / or flame retardants (MC, Ultracarb, Al(OH)3, Mg(OH)2, etc.). The components may be mixed with the inorganic gel after the inorganic gel is prepared, or may be mixed into the precursor solution before the process of preparing the inorganic gel, or may be performed at an appropriate point during the process of preparing the inorganic gel.

[0169] After manufacturing the composite material as described above, it can be placed within a case to form a heat absorbing device. The composite material can be manufactured and placed within the case, or the entire or partial manufacturing process of the composite material can be performed within the case to form the heat absorbing device. For example, the heat absorbing device and the composite material can be manufactured simultaneously by pre-placing the inorganic fibers within the case, injecting the primary polymer, followed by additional polymerization, and then introducing additional components after polymerization, if necessary.

[0170] The present specification also discloses an electronic equipment or device to which the above heat absorbing device is applied.

[0171] The type of electronic equipment or device is not particularly limited. For example, the composite material or heat-absorbing device may be applied to equipment or devices that pose a risk of abnormal heat generation, ignition, and / or explosion during operation, maintenance, and / or storage, and where such abnormal phenomena must be controlled.

[0172] Examples of the above equipment or devices include batteries. In particular, in battery modules comprised of multiple battery cells, it is crucial to prevent abnormal heat generation, ignition, and / or explosion from occurring in one battery cell from spreading to adjacent battery cells.

[0173] The present specification discloses a battery module including the above heat absorbing device.

[0174] Such a battery module may basically include a plurality of battery cells; and the heat absorbing device disposed between the battery cells.

[0175] As long as the above-mentioned heat absorbing device is applied, the specific configuration of the battery module, for example, the type of the battery cell, etc., is not particularly limited, and any known material may be applied. For example, any known pouch-shaped, square-shaped, or cylindrical battery cell may be applied as the battery cell.

[0176] The method for manufacturing the above battery module is not particularly limited, and for example, a method may be used in which a heat absorbing device in the form of a battery cell is manufactured as described above, and then the heat absorbing device is positioned at a required location during the manufacturing process of the battery module.

[0177] The present specification discloses a composite material and a heat absorbing device that can be applied to a product or device that is in an abnormal state or has the potential to experience such an abnormal state, and can effectively respond to heat, ignition, and explosion during such an abnormal state. For example, the composite material and heat absorbing device can be applied to an article comprising multiple products or devices, and can respond to abnormal heat generation, explosion, and ignition occurring in one of the devices or products, and prevent or minimize the spread of such heat generation, explosion, and ignition to other adjacent devices or products. The composite material and heat absorbing device also exhibit excellent handling and storage stability. The present specification can also provide uses for the composite material and heat absorbing device.

[0178] Figure 1 is an exemplary cross-sectional view of a battery module to which a heat absorbing device is applied.

[0179] Figures 2 and 3 are exemplary drawings for explaining the operating principle of the heat absorbing device.

[0180] Figure 4 is an exemplary drawing of an outer shell for packaging a composite material.

[0181] Figure 5 is a laminated structure of a heating and pressing process for deriving a temperature-time graph of a composite material.

[0182] The composite material and the like are specifically described with reference to the following examples, but the scope of the composite material and the like is not limited by the following examples.

[0183]

[0184] Example 1.

[0185] A mixture was prepared by mixing primary distilled water (W), potassium acetate (PC) (molar mass: 98.15 g / mol), hydrochloric acid (molar mass: 36.46 g / mol) aqueous solution (H) (hydrochloric acid concentration: 33 wt%), and liquid sodium silicate (S) in a weight ratio of 63:17:2:5 (W:PC:H:S), and a silica sol was prepared. As the liquid sodium silicate, No. 3 (KS) (No. 3 KS) of Youngil Chemical Co., Ltd. was used.

[0186] The pH of the above mixture was approximately 6 to 7.

[0187] The molal concentration of the hydrochloric acid based on the primary distilled water in the above mixture was approximately 0.3, and the molal concentration of potassium acetate was approximately 2.7. Therefore, in the above mixture, △T of the following equation 2 by the hydrochloric acid f is about 1.0, and △T of the following equation 2 by potassium acetate f is about 10.0.

[0188] [Formula 2]

[0189] △T f = K f Х M Х I

[0190] K in Equation 2 f is the freezing point depression constant of the above-mentioned primary distilled water, which is approximately 1.86 K / m, M is the molal concentration of each ionic compound (hydrochloric acid or potassium acetate), and I is the number of moles of ions generated when 1 mole of the above-mentioned ionic compound is completely dissociated.

[0191] The above silica sol was prepared by stirring the mixture at about 30°C at a speed of about 600 rpm for about 1 minute.

[0192] Next, the silica sol was impregnated into ceramic paper, and gelation was performed to manufacture a composite. At this time, the ceramic paper was HT Ceramic fiber paper (190 kg / m) from HITEMS.3 ) product was used, and impregnation was performed so that the weight (S) of the liquid sodium silicate added during the preparation of the mixture and the weight (CP) of the ceramic paper (S:CP) were approximately 5:13.

[0193] The gelation was carried out at about 30°C after the impregnation, so that gelation could proceed 7 minutes after the silica sol was impregnated into the ceramic paper. The weight ratio of the silica (SiO2) network in the composite was about 1.5 wt%, the content of the ceramic paper was about 13 wt%, and the content of water was about 67 wt%.

[0194] In order to manufacture the heat absorbing device, two outer shells (121, 122) as shown in Fig. 4 were prepared. Each of the outer shells is made of Al material and has a WVTR (Water Vapor Transmission Rate) of approximately 0 g / m 2 ·day. The above WVTR was evaluated according to the standard of ASTM F1249 under the conditions of 38℃ and 100% relative humidity. The composite material was placed in the concave portion (I) of the lower outer shell (122), and after covering it with the upper outer shell (121), the connection portion (S) of the upper outer shell (121) and the lower outer shell (122) was fused at a temperature of about 200℃ to manufacture a heat absorbing device.

[0195]

[0196] Example 2.

[0197] A mixture was prepared by mixing primary distilled water (W), potassium chloride (PC) (molar mass: 74.55 g / mol), an aqueous solution of acetic acid (molar mass: 60.052 g / mol) (H) (acetic acid concentration: 98 wt%), and liquid sodium silicate (S) in a weight ratio of 54:24:1.5:5.5 (W:PC:H:S), and a silica sol was prepared. As the liquid sodium silicate, No. 3 (KS) (No. 3 KS) of Youngil Chemical Co., Ltd. was used.

[0198] The pH of the above mixture was approximately 7 to 8.

[0199] The molal concentration of the acetic acid based on the primary distilled water in the above mixture was about 0.45, and the molal concentration of potassium chloride was about 6. Therefore, △T of Equation 2 of Example 1 by the acetic acid in the above mixture f is about 1.7, and △T of the formula 2 of Example 1 by the potassium chloride f is about 22.2.

[0200] The above silica sol was prepared by stirring the mixture at about 30°C at a speed of about 600 rpm for about 1 minute.

[0201] Next, the silica sol was impregnated into ceramic paper, and gelation was performed to manufacture a composite. At this time, the ceramic paper was HT Ceramic fiber paper (190 kg / m) from HITEMS. 3 ) product was used, and impregnation was performed so that the weight (S) of the liquid sodium silicate added during the preparation of the mixture and the weight (CP) of the ceramic paper (S:CP) were approximately 5.5:15.

[0202] The gelation was carried out at about 30°C after the impregnation, so that gelation could proceed 5 minutes after the silica sol was impregnated into the ceramic paper. The weight ratio of the silica (SiO2) network in the composite was about 1.6 wt%, the content of the ceramic paper was about 15 wt%, and the content of water was about 57.3 wt%.

[0203] A heat absorbing device was manufactured using the above composite material in the same manner as in Example 1.

[0204]

[0205] Example 3.

[0206] A mixture was prepared by mixing primary distilled water (W), potassium acetate (PC) (molar mass: 98.15 g / mol), hydrochloric acid (molar mass: 36.46 g / mol) aqueous solution (H) (hydrochloric acid concentration: 33 wt%), and liquid sodium silicate (S) in a weight ratio of 59:22:2:4.8 (W:PC:H:S), and a silica sol was prepared. As the liquid sodium silicate, No. 3 (KS) (No. 3 KS) of Youngil Chemical Co., Ltd. was used.

[0207] The pH of the above mixture was approximately 5 to 6.

[0208] The molal concentration of the hydrochloric acid based on the primary distilled water in the above mixture was about 0.3, and the molal concentration of potassium acetate was about 3.7. △T of Equation 2 of Example 1 by the hydrochloric acid in the above mixture f is about 1.1, and △T of the formula 2 of Example 1 by the potassium acetate f is about 13.8.

[0209] The above silica sol was prepared by stirring the mixture at about 35°C for about 1 minute at a speed of about 600 rpm.

[0210] Next, the silica sol was impregnated into ceramic paper, and gelation was performed to manufacture a composite. At this time, the ceramic paper was HT Ceramic fiber paper (190 kg / m) from HITEMS. 3 ) product was used, and impregnation was performed so that the ratio (S:CP) of the weight (S) of the liquid sodium silicate added during the preparation of the mixture and the weight (CP) of the ceramic paper was approximately 4.8:12.2.

[0211] The gelation was carried out at about 35°C after the impregnation, so that gelation could proceed 10 minutes after the silica sol was impregnated into the ceramic paper. The weight ratio of the silica (SiO2) network in the composite was about 1.4 wt%, the content of the ceramic paper was about 12.2 wt%, and the content of water was about 63 wt%.

[0212] A heat absorbing device was manufactured using the above composite material in the same manner as in Example 1.

[0213]

[0214] Example 4.

[0215] A mixture was prepared by mixing primary distilled water (W), potassium acetate (PC) (molar mass: 98.15 g / mol), hydrochloric acid (molar mass: 36.46 g / mol) aqueous solution (H) (hydrochloric acid concentration: 33 wt%), and liquid sodium silicate (S) in a weight ratio of 52:28:2:5 (W:PC:H:S), and a silica sol was prepared. As the liquid sodium silicate, No. 3 (KS) (No. 3 KS) of Youngil Chemical Co., Ltd. was used.

[0216] The pH of the above mixture was approximately 7 to 8.

[0217] The molal concentration of the hydrochloric acid based on the primary distilled water in the above mixture was about 0.3, and the molal concentration of potassium acetate was about 5.3. △T of Equation 2 of Example 1 by the hydrochloric acid in the above mixture f is about 1.3, and △T of the formula 2 of Example 1 by the potassium acetate f is about 19.9.

[0218] The above silica sol was prepared by stirring the mixture at about 35°C for about 1 minute at a speed of about 600 rpm.

[0219] Next, the silica sol was impregnated into ceramic paper, and gelation was performed to manufacture a composite. At this time, the ceramic paper was HT Ceramic fiber paper (190 kg / m) from HITEMS. 3 ) product was used, and impregnation was performed so that the weight (S) of the liquid sodium silicate added during the preparation of the mixture and the weight (CP) of the ceramic paper (S:CP) were approximately 5:13.

[0220] The gelation was carried out at about 35°C after the impregnation, so that gelation could proceed 10 minutes after the silica sol was impregnated into the ceramic paper. The weight ratio of the silica (SiO2) network in the composite was about 1.5 wt%, the content of the ceramic paper was about 13 wt%, and the content of water was about 56 wt%.

[0221] A heat absorbing device was manufactured using the above composite material in the same manner as in Example 1.

[0222]

[0223] Example 5.

[0224] A mixture was prepared by mixing primary distilled water (W), potassium acetate (PC) (molar mass: 98.15 g / mol), sodium hydroxide (molar mass: 39.997 g / mol) aqueous solution (H1) (sodium hydroxide concentration: 40 wt%), acetic acid (molar mass: 60.052 g / mol) aqueous solution (H2) (acetic acid concentration: 99 wt%), and liquid sodium silicate (S) in a weight ratio of 54:18:0.1:1.1:11.8 (W:PC:H1:H2:S), and a silica sol was prepared. As the liquid sodium silicate, No. 3 (KS) (No. 3 KS) of Youngil Chemical Co., Ltd. was used.

[0225] The pH of the above mixture was approximately 7 to 8.

[0226] In the above mixture, the molal concentration of the sodium hydroxide based on the first distilled water was about 0.02, the molal concentration of acetic acid was about 0.3, and the molal concentration of potassium acetate was about 3.4. In the above mixture, △T of the equation 2 of Example 1 by the sodium hydroxide f is about 0.07, and △T of formula 2 of Example 1 by acetic acid f is about 1.2, and △T of the formula 2 of Example 1 by the potassium acetate f is about 12.6.

[0227] The above silica sol was prepared by stirring the mixture at about 25°C at a speed of about 600 rpm for about 1 minute.

[0228] Next, the silica sol was impregnated into ceramic paper, and gelation was performed to manufacture a composite. At this time, the ceramic paper was HT Ceramic fiber paper (190 kg / m) from HITEMS. 3) product was used, and impregnation was performed so that the weight ratio (S:CP) of the liquid sodium silicate added during the preparation of the mixture and the weight (CP) of the ceramic paper was approximately 11.8:15.

[0229] The gelation was carried out at about 25°C after the impregnation, so that gelation could proceed 10 minutes after the silica sol was impregnated into the ceramic paper. The weight ratio of the silica (SiO2) network in the composite was about 3.4 wt%, the content of the ceramic paper was about 15 wt%, and the content of water was about 61.2 wt%.

[0230] A heat absorbing device was manufactured using the above composite material in the same manner as in Example 1.

[0231]

[0232] Comparative Example 1.

[0233] A hydrogel was prepared by absorbing distilled water (W) into a superabsorbent polymer (SAP) (SONGWON, HI-SWELL HS-1000V) at a weight ratio of 1:9 (SAP:W) to prepare a composite. A heat absorbing device was prepared using the composite in the same manner as in Example 1.

[0234]

[0235] Comparative Example 2.

[0236] Ceramic paper 380gsm 2T substrate (HITEMS, HT Ceramic fiber paper, 190kg / m 3 , 2T) was allowed to absorb water for more than 24 hours, then the ceramic paper was taken out and the moisture on the outer surface was removed to prepare a composite. Using the composite, a heat absorbing device was manufactured in the same manner as in Example 1.

[0237]

[0238] Comparative Example 3.

[0239] A mixture was prepared by mixing primary distilled water (W), an aqueous solution of acetic acid (molar mass: 60.052 g / mol) (acetic acid concentration: 98 wt%), and liquid sodium silicate (S) in a weight ratio of 79.2:2:5.3 (W:H:S), and a silica sol was prepared. As the liquid sodium silicate, No. 3 (KS) (No. 3 KS) of Youngil Chemical Co., Ltd. was used.

[0240] The pH of the above mixture was approximately 8 to 9.

[0241] The molal concentration of the acetic acid in the mixture based on the primary distilled water was approximately 0.4. △T of the equation 2 of Example 1 by the acetic acid in the mixture f was about 1.53.

[0242] The above silica sol was prepared by stirring the mixture at about 35°C for about 1 minute at a speed of about 600 rpm.

[0243] Next, the silica sol was impregnated into ceramic paper, and gelation was performed to manufacture a composite. At this time, the ceramic paper was HT Ceramic fiber paper (190 kg / m) from HITEMS. 3 ) product was used, and impregnation was performed so that the ratio (S:CP) of the weight (S) of the liquid sodium silicate added during the preparation of the mixture and the weight (CP) of the ceramic paper was approximately 5.3:13.5.

[0244] The gelation was carried out at about 35°C after the impregnation so that gelation could proceed 12 minutes after the silica sol was impregnated into the ceramic paper. The weight ratio of water in the composite was about 82 wt%, the content of the silica (SiO2) network was about 1.9 wt% based on 100 wt% of the water, and the content of the ceramic paper was about 16 wt% based on 100 wt% of the water.

[0245] A heat absorbing device was manufactured using the above composite material in the same manner as in Example 1.

[0246]

[0247] Comparative Example 4.

[0248] A mixture was prepared by mixing primary distilled water (W), potassium acetate (PC) (molar mass: 98.15 g / mol), sodium hydroxide (molar mass: 39.997 g / mol) aqueous solution (H1) (sodium hydroxide concentration: 40 wt%), acetic acid (molar mass: 60.052 g / mol) aqueous solution (H2) (acetic acid concentration: 99 wt%), and liquid sodium silicate (S) in a weight ratio of 67:4.5:0.1:1.1:12.3 (W:PC:H1:H2:S), and a silica sol was prepared. As the liquid sodium silicate, No. 3 (KS) (No. 3 KS) of Youngil Chemical Co., Ltd. was used.

[0249] The pH of the above mixture was approximately 7 to 8.

[0250] In the above mixture, the molal concentration of the sodium hydroxide based on the first distilled water was about 0.01, the molal concentration of acetic acid was about 0.3, and the molal concentration of potassium acetate was about 0.7. In the above mixture, △T of the equation 2 of Example 1 by the sodium hydroxide f is about 0.06, and △T of the formula 2 of the above Example 1 by the acetic acid f is about 1, and △T of the formula 2 of Example 1 by the potassium acetate f is about 2.5.

[0251] The above silica sol was prepared by stirring the mixture at about 25°C at a speed of about 600 rpm for about 1 minute.

[0252] Next, the silica sol was impregnated into ceramic paper, and gelation was performed to manufacture a composite. At this time, the ceramic paper was HT Ceramic fiber paper (190 kg / m) from HITEMS. 3 ) product was used, and impregnation was performed so that the ratio (S:CP) of the weight (S) of the liquid sodium silicate added during the preparation of the mixture and the weight (CP) of the ceramic paper was approximately 12.3:15.

[0253] The gelation was carried out at about 25°C after the impregnation so that gelation could proceed 10 minutes after the silica sol was impregnated into the ceramic paper. The weight ratio of water in the composite was about 74.5 wt%, the content of the silica (SiO2) network was about 5 wt% based on 100 wt% of the water, and the content of the ceramic paper was about 20.1 wt% based on 100 wt% of the water.

[0254] A heat absorbing device was manufactured using the above composite material in the same manner as in Example 1.

[0255]

[0256] Comparative Example 5.

[0257] Tetraethyl orthosilicate (TEOS) and water were mixed in a molar ratio of 3:1 (TEOS:water), and ethanol (EtOH) was added to the TEOS in a weight ratio of 4:1 (TEOS:EtOH) to prepare a precursor solution. After adding an acid that induces hydrolysis of the precursor to prepare a solution, ethanol (EtOH) was added to the prepared solution (S) in a weight ratio of 1:3 (S:EtOH) to prepare a silica sol. Subsequently, a base catalyst solution (10 wt% NaOH aqueous solution) was added to the silica sol (S) in a volume ratio of 99.6:0.4 (S:NaOH aqueous solution) to prepare a catalyzed sol. The above catalyzed sol was impregnated into ceramic paper and gelation was performed, and the gelled sample was aged and surface modified in an 8 wt% TMES (trimethylethoxysilane) solution at 60°C for about 48 hours to produce a hydrogel blanket. The produced hydrogel blanket was placed in a supercritical extractor, supercritical CO2 was injected, and supercritical drying was performed at a temperature of 70°C or higher and a pressure of 90 bar or higher to produce an aerogel blanket, which was used instead of a composite material to produce a heat absorbing device in the same manner as in Example 1.

[0258]

[0259] Test Example 1.

[0260] A heating plate (5000), an insulation board (2000), and a cooling plate (3000) were prepared. As shown in Fig. 5, an insulation board (2000) was laminated on the cooling plate (3000), and a temperature measuring device (thermal coupler) (4000) was installed on the insulation board (2000). The temperature measuring device (thermal coupler) (4000) was positioned so that the surface of the device (4000) and the surface of the insulation board (2000) formed the same horizontal surface. A groove was formed on the surface of the insulation board (2000), and the temperature measuring device (4000) was inserted into the groove to match the height. The insulation board (1000) was used as an Incera Board 10T product from HITEMS.

[0261] The sample (1000) to be measured (width: 7.5 cm, length: 7.5 cm) was placed on an insulating board (2000) and a temperature measuring device (4000), and the temperature of the heating plate (5000) was stabilized at 700°C. Then, the sample (1000) was pressed by the heating plate (5000) maintained at a temperature of 700°C, and the temperature change was confirmed by the temperature measuring device (4000). Before pressurizing by the heating plate (5000), if the temperature of the temperature measuring device (4000) was 50°C or higher, the sample was waited until the temperature dropped below 50°C, and then pressurizing by the heating plate (5000) was performed. During the above process, the temperature of the cooling plate (3000) was maintained at a level of 20°C to 30°C.

[0262] The above pressurization was performed at a pressure of approximately 50 kPa.

[0263]

[0264] Table 1 below shows the time to reach 180°C and the inflection point confirmation temperature (temperature at which the inflection point is confirmed) confirmed through the above test results. The time to reach 180°C is the time required from the time when pressurization with the heating plate (5000) begins in the above process until the temperature of 180°C is confirmed by the temperature measuring device (4000). In addition, the inflection point confirmation temperature is the temperature at the point where the direction of the bend changes in the graph when the temperature confirmed by the temperature measuring device (4000) in the above experiment process is expressed as a graph over time (x-axis: time, y-axis: temperature).

[0265] 180℃ Reaching Time (sec) Inflection Point Confirmation Temperature (℃) Example 16792 Example 26392 Example 36993 Example 45892 Example 514294 Comparative Example 18 (Dissolution) 98 Comparative Example 213 (Dissolution) 96 Comparative Example 37793 Comparative Example 47392 Comparative Example 5295 None

[0266]

[0267] Test Example 2.

[0268] The heat absorbing devices manufactured in the examples and comparative examples were placed in a cooling chamber capable of maintaining a constant temperature. After the temperature inside the cooling chamber reached the set temperature (approximately -30℃), the temperature was maintained and stored for 20 hours. After the heat absorbing device was taken out of the cooling chamber, the thickness t2 was measured within 1 minute. At this time, the thickness was measured at three arbitrary points (3-points) of the heat absorbing device at intervals of >2 cm while applying a pressure of approximately 2 kPa, and then the value obtained was obtained by averaging the three measured values.

[0269] The thickness t1 at 25°C and the thickness t2 at -30°C were substituted into the formula [(t2-t1) / t1] Х 100 to calculate the thickness change rate △T, which was recorded as shown in Table 2 below.

[0270] The thickness at 25°C was measured in the same manner as described above before placing the heat absorbing device into the cooling chamber.

[0271] △T (%) Example 12.6 Example 22.9 Example 3-1.7 Example 4-0.6 Example 51.5 Comparative Example 18.1 Comparative Example 27.8 Comparative Example 37.2 Comparative Example 46.5 Comparative Example 50.8

[0272] Specifically, when the composites of Examples 1 to 5 were used, the heat absorption performance and heat blocking properties of the composites were significantly improved, while the thickness increase rate was low or the thickness tended to decrease, confirming that the stability in harsh environments such as battery packs could be improved.

[0273] In the case of Comparative Examples 1 to 4, there was a problem in that when the thickness change rate was high and these were inserted into a battery pack, etc., pressure was applied to the densely assembled battery pack structure, which may cause the jig constituting the battery pack to detach, or the pressure applied to the cell may increase, which may cause a decrease in the performance of the cell and / or an explosion. In addition, in the case of Comparative Examples 1 and 2, the temperature rose rapidly, which resulted in the dissolution of substances inside the composite.

[0274] In the case of Comparative Example 5, since there was no inflection section due to the lack of an endothermic solution containing an ionic compound, the endothermic performance of the composite was significantly reduced, and since the moisture content within the composite was low, the ability to fundamentally remove the heat energy generated when thermal propagation occurred was significantly reduced, so there was a limit to securing stability by lowering the temperature of the battery pack despite the low thickness change rate.

[0275] Therefore, when using the composite material disclosed in this specification, chain ignition can be suppressed through a rapid extinguishing action using the latent heat of the internal heat absorbent in the event of ignition, heat generation, etc., and while exhibiting an excellent insulation effect, the stability of the battery pack can be effectively secured by having a low thickness increase rate.

Claims

1. A case; and a composite material present within the case, The above composite material comprises a volatile material and an inorganic gel, An absorbing device in which the absolute value of △T in Equation 1 below is 5% or less: [Formula 1] △T = [(t2-t1) / t1] Х 100 In Equation 1, t2 is the thickness after the heat absorber is maintained at -30°C for 20 hours, and t1 is the thickness at 25°C before the heat absorber is maintained at -30°C for 20 hours.

2. In claim 1, An absorber showing an inflection point in a temperature-time graph obtained under conditions of a temperature of 700°C and a pressure of 50 kPa.

3. In claim 2, An absorption device that reaches 180℃ in 30 seconds or more in the above temperature-time graph.

4. In claim 1, The above volatile material is a heat absorbing device in which water is used.

5. In claim 1, An endothermic device comprising 40 to 90 wt% of a vaporizable material.

6. In claim 1, An absorbent device comprising 0.5 to 15 parts by weight of an inorganic gel relative to 100 parts by weight of a volatile material.

7. In claim 1, The inorganic gel is a heat absorbing device made of silica gel.

8. In claim 1, An absorbent device additionally comprising inorganic fibers.

9. In claim 8, The inorganic fiber is a heat absorbing device in the form of woven, non-woven or paper.

10. In claim 8, A heat absorbing device in which an inorganic gel is attached to an inorganic fiber, or in which the inorganic gel and the inorganic fiber are entangled with each other.

11. In claim 8, An absorbent device comprising 3 to 50 parts by weight of inorganic fibers relative to 100 parts by weight of a volatile material.

12. In claim 1, △T of Equation 2 below f An endothermic device further comprising an ionic compound having a molecular weight of 5 to 50: [Formula 2] △T f = K f 1991 K in Equation 2 f is the freezing point depression constant of the volatile substance, M is the molal concentration of the ionic compound with respect to the volatile substance, and I is the number of moles of ions produced when 1 mole of the ionic compound is completely dissociated.

13. In claim 12, The above ionic compound is an absorbent device, wherein at least one is selected from the group consisting of potassium salts, sodium salts, magnesium salts, and ammonium salts.

14. A method for manufacturing an absorbing device according to claim 1, comprising the step of polymerizing a precursor solution containing an inorganic gel precursor and a vaporizable material.

15. In claim 14, A method for manufacturing an absorption device in which polymerization is performed while maintaining the pH of the precursor solution in the range of 5 to 10.

16. In claim 14, Polymerization is performed when the precursor solution is △T of the following equation 2 f A method for manufacturing an endothermic device, which is performed at a temperature in the range of 20°C to 40°C in a state in which an ionic compound is included so as to be in the range of 5 to 50: [Formula 2] △T f = K f 1991 K in Equation 2 f is the freezing point depression constant of the volatile substance, M is the molal concentration of the ionic compound with respect to the volatile substance, and I is the number of moles of ions produced when 1 mole of the ionic compound is completely dissociated.

17. In claim 14, A method for manufacturing an absorbent device, the polymerization comprising the step of stirring the precursor solution at a speed of 100 to 1,000 rpm.

18. In claim 14, A method for manufacturing an absorbent device comprising the step of polymerizing an inorganic gel precursor or a prepolymer of an inorganic gel precursor in the presence of inorganic fibers.

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