Resin composition

Abstract

The present application relates to a resin composition, a battery module, and a battery pack. According to an example of the present application, a urethane heat dissipation material capable of providing excellent thermal conductivity and storage stability is provided.

Description

[0001] This application is a divisional application of an application with an application date of March 19, 2019, a priority date of March 28, 2018, an application number of 201980004483.3, and an invention title of "Resin Composition" (PCT / KR2019 / 003152, the date of entry into the national phase is March 12, 2020).

[0002] Cross - reference to related applications

[0003] This application claims the benefit of priority based on Korean Patent Application No. 10-2018-0035751, filed on March 28, 2018, and Korean Patent Application No. 10-2019-0029279, filed on March 14, 2019, the disclosures of which are incorporated herein by reference in their entirety. Technical Field

[0004] This application relates to a resin composition. Specifically, this application relates to a resin composition, a battery module, a battery pack, and an automobile including a cured product of the resin composition. Background Art

[0005] Secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, or lithium secondary batteries, etc., and typical examples thereof are lithium secondary batteries.

[0006] Lithium secondary batteries mainly use lithium oxide and carbon materials as the positive electrode active material and the negative electrode active material, respectively. A lithium secondary battery includes: an electrode assembly in which a positive electrode plate and a negative electrode plate coated with the positive electrode active material and the negative electrode active material, respectively, are provided with a separator therebetween; and an outer material in which the electrode assembly and an electrolyte are sealed and accommodated, and the lithium secondary battery can be classified into a can-type secondary battery and a pouch-type secondary battery according to the type of the outer material. Such a single secondary battery may be referred to as a battery cell.

[0007] In the case of medium and large-sized devices such as automobiles or power storage systems, for capacity and power, a battery module in which a large number of battery cells are electrically connected to each other may be used, or a battery pack in which a plurality of such battery modules are connected may be used.

[0008] One of the methods of constructing the battery module or the battery pack as described above is to use an adhesive material capable of fixing a plurality of battery cells in the battery module. At this time, the adhesive material may be injected into the battery module through an adhesive material injection hole formed on the surface of the battery module. A liquid silicone series is mainly used for injection, and in the case of the silicone series, there is a problem that the adhesive force is insufficient or even low molecular weight siloxane causes contact failure after curing.

[0009] On the other hand, in order to eliminate the adhesion problem described above, a room temperature curable urethane adhesive of the two-component type can be used, but in the components of the two-component urethane, isocyanate is very susceptible to moisture. Summary of the Invention

[0010] The present application provides the following embodiments.

[0011] Embodiment 1. A two-component urethane composition comprising a main composition portion containing an ester-based polyol resin; a curing agent composition portion containing a polyisocyanate; a filler; and a moisture remover,

[0012] wherein the ester-based polyol resin is an amorphous polyol in which no crystallization temperature Tc and melting temperature Tm are observed in differential scanning calorimetry (DSC) analysis, or has a melting temperature Tm of less than 15 °C.

[0013] Embodiment 2. The two-component urethane composition according to Embodiment 1, wherein the main composition portion or the curing agent composition portion contains the filler and the moisture remover.

[0014] Embodiment 3. The two-component urethane composition according to Embodiment 1, wherein the filler includes alumina, aluminum nitride (AlN), boron nitride (BN), silicon nitride, SiC, or BeO.

[0015] Embodiment 4. The two-component urethane composition according to Embodiment 1, wherein the filler is included in an amount of 50 parts by weight to 2,000 parts by weight relative to the total of 100 parts by weight of the ester-based polyol resin content and the polyisocyanate content.

[0016] Embodiment 5. The two-component urethane composition according to Embodiment 1, wherein the moisture remover is selected from methyl diphenyl ethoxysilane, molecular sieve, p-toluenesulfonyl isocyanate (PTSI), acid anhydride ester, a silane compound represented by the following formula, and mixtures thereof:

[0017] [Formula]

[0018] R 1 SiR 2 (n) R 3 (3-n)

[0019] wherein, R 1 is a functional group having a carbon-carbon double bond bonded to a silicon atom, and R 2 and R 3 each independently represent a hydroxyl group, a halogen, an amino group, or -R 4 R5 , wherein R 4 is an oxygen atom or a sulfur atom, and R 5 is an alkyl group, an aryl group, an aralkyl group, an acyl group or -R 6 R 7 , wherein R 6 is an alkylene group, and R 7 is an alkoxy group.

[0020] Embodiment 6. The two-component urethane composition according to Embodiment 5, wherein the silane compound includes vinyltrimethoxysilane, vinyltriethoxysilane, vinyltripropoxysilane, vinyltriisopropoxysilane, vinyltributoxysilane, vinyltripentyloxysilane, vinyltriphenoxysilane, vinyltriacetoxysilane, or vinyltris(2-methoxyethoxy)silane.

[0021] Embodiment 7. The two-component urethane composition according to Embodiment 1, wherein the glass transition temperature Tg of the mixture of the ester-based polyol resin and the polyisocyanate after curing is lower than 0°C.

[0022] Embodiment 8. The two-component urethane composition according to Embodiment 1, wherein the viscosities of the ester-based polyol resin and the polyisocyanate are each less than 900 cP.

[0023] Embodiment 9. The two-component urethane composition according to Embodiment 1, wherein the ester-based polyol resin is represented by Formula 1 or 2:

[0024] [Formula 1]

[0025]

[0026] [Formula 2]

[0027]

[0028] wherein, X is a carboxylic acid-derived unit, Y is a polyol-derived unit, n is a number in the range of 2 to 10, and m is a number in the range of 1 to 10.

[0029] Embodiment 10. The two-component urethane composition according to Embodiment 9, wherein the carboxylic acid-derived unit X is one or more units selected from the following: phthalic acid unit, isophthalic acid unit, terephthalic acid unit, trimellitic acid unit, tetrahydrophthalic acid unit, hexahydrophthalic acid unit, tetrachlorophthalic acid unit, and fatty acid unit.

[0030] Embodiment 11. The two-component urethane composition according to Embodiment 9, wherein the polyol-derived unit Y is any one or two or more units selected from the following: ethylene glycol unit, propylene glycol unit, 1,2-butanediol unit, 2,3-butanediol unit, 1,3-propanediol unit, 1,3-butanediol unit, 1,4-butanediol unit, 1,6-hexanediol unit, neopentyl glycol unit, 1,2-ethylhexanediol unit, 1,5-pentanediol unit, 1,9-nonanediol unit, 1,10-decanediol unit, 1,3-cyclohexanedimethanol unit, 1,4-cyclohexanedimethanol unit, glycerol unit, and trimethylolpropane unit.

[0031] Embodiment 12. The two-component urethane composition according to Embodiment 1, wherein the polyisocyanate is a non-aromatic polyisocyanate.

[0032] Embodiment 13. The two-component urethane composition according to Embodiment 9, wherein the carboxylic acid-derived unit X is one or more units selected from the following: phthalic acid unit, isophthalic acid unit, terephthalic acid unit, trimellitic acid unit, tetrahydrophthalic acid unit, hexahydrophthalic acid unit, tetrachlorophthalic acid unit, oxalic acid unit, adipic acid unit, azelaic acid unit, sebacic acid unit, succinic acid unit, malic acid unit, glutaric acid unit, malonic acid unit, pimelic acid unit, suberic acid unit, 2,2-dimethylsuccinic acid unit, 3,3-dimethylglutaric acid unit, 2,2-dimethylglutaric acid unit, maleic acid unit, fumaric acid unit, and itaconic acid unit.

[0033] Embodiment 14. A battery module, comprising: a module housing having a top plate, a bottom plate, and side walls, wherein an internal space is formed by the top plate, the bottom plate, and the side walls;

[0034] A plurality of battery cells present in the internal space of the module housing; and

[0035] A resin layer formed by curing the composition according to Embodiment 1 and in contact with the plurality of battery cells.

[0036] Embodiment 15. A battery pack, comprising one or more battery modules according to Embodiment 14.

[0037] Embodiment 16. An automobile, comprising the battery module according to Embodiment 14 or the battery pack according to Embodiment 15.

[0038] An object of the present application is to provide a resin composition for a battery module that can solve the above problems.

[0039] Another object of the present application is to provide a resin composition for a battery module having excellent heat dissipation, adhesion strength, cold resistance, heat resistance, insulation, and adhesion reliability.

[0040] Another object of the present application is to provide a battery module and a battery pack.

[0041] The above and other objects of the present application can be fully solved by the present application, which will be described in detail below.

[0042] Technical solution

[0043] In an example related to the present application, the present application relates to a composition for a battery module or a battery pack. Specifically, the composition of the present application can be a composition for fixing one or more battery cells in a module housing by injecting it into the housing of the battery module and contacting the battery cells present in the battery module, as described below.

[0044] In the present application, a urethane-based composition can be used as the composition. Specifically, in the present application, a two-component urethane-based composition can be used. Two-component urethane means a polyurethane formed by mixing an isocyanate-based compound and a polyol-based compound, which is different from a one-component polyurethane having a urethane group in a single composition.

[0045] In the case of two-component polyurethane, a main material containing a polyol or the like and a curing agent containing an isocyanate or the like can react and cure at room temperature. That is, the composition of the present application can be a room-temperature curing type. In the present application, the term "room temperature" is a state without special heating or cooling, which can mean any temperature in the range of about 10°C to 30°C, for example, a temperature of about 15°C or higher, 18°C or higher, 20°C or higher, or about 23°C or higher and about 27°C or lower. The curing reaction can be assisted by a catalyst such as dibutyltin dilaurate (DBTDL). Therefore, the two-component urethane-based composition can contain a physical mixture of a main component (polyol) and a curing agent component (isocyanate), and / or can contain a reaction product (cured product) of the main component and the curing agent component.

[0046] The two-component urethane-based composition of the present application can include a main composition part (or main part) containing at least a polyol resin and / or a curing agent composition part (or curing agent part) containing at least a polyisocyanate. Therefore, the cured product of the resin composition can contain both polyol-derived units and polyisocyanate-derived units. At this time, the polyol-derived units can be units formed by subjecting a polyol to a urethane reaction with a polyisocyanate, and the polyisocyanate-derived units can be units formed by subjecting a polyisocyanate to a urethane reaction with a polyol.

[0047] The composition may further comprise a filler. For example, in order to ensure the thixotropy required during the process and / or in order to ensure the heat dissipation (thermal conductivity) within the battery module or battery pack, the composition of the present application may comprise an excessive amount of filler, as described below. Details will be described in detail in the following related description.

[0048] In addition, the composition comprises a dehumidifying agent. The dehumidifying agent can be used to eliminate the adverse effects of moisture on the respective components comprised in the composition. For example, the dehumidifying agent can be used to ensure the storage stability of the main composition part and / or the curing agent composition part. Details are described below.

[0049] In one example, an ester-based polyol resin can be used as the polyol resin comprised in the main composition part. When using an ester-based polyol, it is beneficial to ensure excellent adhesiveness and adhesion reliability in the battery module after curing the resin composition.

[0050] In one example, as the ester-based polyol, for example, a carboxylic acid-based polyol or a caprolactone-based polyol can be used.

[0051] The carboxylic acid-based polyol can be formed by reacting a component comprising a carboxylic acid and a component comprising a polyol (e.g., diol or triol), and the caprolactone-based polyol can be formed by reacting a component comprising caprolactone and a component comprising a polyol (e.g., diol or triol). At this time, the carboxylic acid can be a dicarboxylic acid.

[0052] In one example, the polyol can be a polyol represented by Formula 1 or 2 below.

[0053] [Formula 1]

[0054]

[0055] [Formula 2]

[0056]

[0057] In Formulas 1 and 2, X is a unit derived from a carboxylic acid, and Y is a unit derived from a polyol. The unit derived from a polyol can be, for example, a triol unit or a diol unit. In addition, n and m can be any numbers.

[0058] In the above formula, the unit derived from a carboxylic acid is a unit formed by reacting a carboxylic acid with a polyol, and the unit derived from a polyol is a unit formed by reacting a polyol with a carboxylic acid or caprolactone.

[0059] That is, when the hydroxyl group of the polyol reacts with the carboxyl group of the carboxylic acid, water (H 2O) An ester bond is formed with a molecule, where after the carboxylic acid forms an ester bond through a condensation reaction, X in Formula 1 above means a part other than the ester bond portion. Further, after the polyol forms an ester bond through a condensation reaction, Y is a part other than the ester bond. The ester bond is shown in Formula 1.

[0060] In addition, after the polyol forms an ester bond with caprolactone, Y in Formula 2 also represents a part other than the ester bond. The ester bond is shown in Formula 2.

[0061] On the other hand, when the unit Y derived from the polyol in the above formula is a unit derived from a polyol having three or more hydroxyl groups, such as a triol unit, a branched structure can be achieved in the Y part in the formula structure.

[0062] In Formula 1 above, the type of the unit X derived from the carboxylic acid is not particularly limited, but in order to ensure desired physical properties, it can be any one of the following units: phthalic acid unit, isophthalic acid unit, terephthalic acid unit, trimellitic acid unit, tetrahydrophthalic acid unit, hexahydrophthalic acid unit, tetrachlorophthalic acid unit, oxalic acid unit, adipic acid unit, azelaic acid unit, sebacic acid unit, succinic acid unit, malic acid unit, glutaric acid unit, malonic acid unit, pimelic acid unit, suberic acid unit, 2,2-dimethylsuccinic acid unit, 3,3-dimethylglutaric acid unit, 2,2-dimethylglutaric acid unit, maleic acid unit, fumaric acid unit, itaconic acid unit, and fatty acid unit. From the viewpoint of a low glass transition temperature within the above range, an aliphatic carboxylic acid-derived unit can be superior to an aromatic carboxylic acid-derived unit.

[0063] On the other hand, in Formulas 1 and 2, the type of the unit Y derived from the polyol is not particularly limited, but in order to ensure desired physical properties, it can be one or more of the following: ethylene glycol unit, diethylene glycol unit, propylene glycol unit, 1,2-butanediol unit, 2,3-butanediol unit, 1,3-propanediol unit, 1,3-butanediol unit, 1,4-butanediol unit, 1,6-hexanediol unit, neopentyl glycol unit, 1,2-ethylhexanediol unit, 1,5-pentanediol unit, 1,9-nonanediol unit, 1,10-decanediol unit, 1,3-cyclohexanedimethanol unit, 1,4-cyclohexanedimethanol unit, glycerol unit, and trimethylolpropane unit.

[0064] On the other hand, in Formula 1 above, n is an arbitrary number, and the range can be selected in consideration of the desired physical properties of the resin composition or the resin layer as its cured product. For example, n can be about 2 to 10, or 2 to 5.

[0065] In addition, in Formula 2 above, m is an arbitrary number, and the range can be selected in consideration of the desired physical properties of the resin composition or the resin layer as its cured product. For example, m is about 1 to 10, or 1 to 5.

[0066] If n and m in Formulas 1 and 2 are outside the above ranges, the crystallizability performance of the polyol becomes stronger, which may adversely affect the injectable processability of the composition.

[0067] The molecular weight of the polyol can be adjusted in consideration of low viscosity characteristics, durability, adhesiveness, etc. as described below, and it can be in the range of, for example, about 300 to 2,000. Unless otherwise specified, in this specification, the "molecular weight" can be the weight-average molecular weight (Mw) measured using GPC (gel permeation chromatography). If it is outside the above range, the reliability of the resin layer after curing may be poor, and problems related to volatile components may occur.

[0068] In the present application, the polyisocyanate can mean a compound containing two or more isocyanate groups.

[0069] In the present application, the type of polyisocyanate contained in the curing agent composition part is not particularly limited, but in order to ensure the desired physical properties, a non-aromatic isocyanate compound not containing an aromatic group can be used. That is, it may be advantageous to use an aliphatic series or an alicyclic series. When using an aromatic polyisocyanate, the reaction rate may be too fast and the glass transition temperature of the cured product may increase, so it may be difficult to ensure the processability and physical properties suitable for the use of the composition of the present application.

[0070] For example, an aliphatic or alicyclic polyisocyanate or its modified product can be used. Specifically, aliphatic polyisocyanates such as hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate, norbornane diisocyanate, ethylene diisocyanate, propylene diisocyanate, or tetramethylene diisocyanate can be used; alicyclic polyisocyanates such as trans-cyclohexane-1,4-diisocyanate, isophorone diisocyanate, bis(isocyanatomethyl)cyclohexane diisocyanate, or dicyclohexylmethane diisocyanate; or one or more of the foregoing carbodiimide-modified polyisocyanates or isocyanurate-modified polyisocyanates; and so on. In addition, a mixture of two or more of the compounds listed above can be used.

[0071] The ratio of the resin component derived from the polyol and the resin component derived from the polyisocyanate in the resin composition is not particularly limited, and it can be appropriately adjusted so that the urethane reaction between them can occur.

[0072] As described above, in order to ensure the heat dissipation (thermal conductivity) or thixotropy required during the process, the composition may contain an excessive amount of filler. If an excessive amount of filler is used, the viscosity of the composition increases, so that the processability when injecting the composition into the housing of the battery module may deteriorate. Therefore, while containing an excessive amount of filler, it is required to have a low viscosity property sufficient not to interfere with the processability. In addition, when only a low viscosity is exhibited, it is also difficult to ensure the processability. Therefore, it may be necessary to have appropriate thixotropy, exhibit excellent adhesiveness during curing, and the curing itself is carried out at room temperature. Then, the ester-based polyol is advantageous for ensuring the adhesiveness after curing, but is highly crystalline, so it is highly likely to become waxy at room temperature, and it is not conducive to ensuring appropriate injectable processability due to the increased viscosity. Even if it is used after reducing the viscosity by melting, due to the crystallinity that occurs naturally during storage, the viscosity increases due to crystallization during the injection or application of the composition, which can continue after mixing with the filler, and therefore, the processability may be reduced. Considering this, the ester-based polyol used in the present application can satisfy the following properties.

[0073] In the present application, the ester-based polyol can be an amorphous or sufficiently low-crystallinity polyol. Here, "amorphous" means that no crystallization temperature (Tc) and melting temperature (Tm) are observed in DSC (differential scanning calorimetry) analysis. DSC analysis can be performed using known devices such as Q2000 (TA instruments). Specifically, DSC analysis can be performed at a rate of 10 °C / min in the range of -80 °C to 60 °C, and for example, a method can be performed in which the temperature is raised from 25 °C to 50 °C at the above rate, then the temperature is lowered to -70 °C and raised to 50 °C again. Here, "sufficiently low crystallinity" means that the melting point or melting temperature (Tm) observed in DSC analysis is lower than 15 °C (which is about 10 °C or lower, 5 °C or lower, 0 °C or lower, -5 °C or lower, -10 °C or lower, or about -20 °C or lower). At this time, the lower limit of the melting point is not particularly limited, but for example, the melting point can be about -80 °C or higher, about -75 °C or higher, or about -70 °C or higher. When the polyol is crystalline or has high (room temperature) crystallizability (for example, does not satisfy the melting point range), the viscosity difference depending on the temperature easily increases. Therefore, during the process of mixing the filler and the resin, it may adversely affect the dispersion of the filler and the viscosity of the final mixture, the processability is reduced, and therefore, it may become difficult to satisfy the cold resistance, heat resistance, and water resistance required for the adhesive composition for the battery module.

[0074] Figure 1A graph showing DSC analysis results of several polyols as examples for determining the amorphous or sufficiently low crystallizable properties of ester-based polyols. According to the present application, it can be determined that sample #1 is amorphous, and it can be determined that samples #2 and #3 are sufficiently low in crystallinity. On the other hand, in the case of sample #4 with a melting temperature (Tm) of 33.52 °C, it can be said that the crystallinity is high.

[0075] The glass transition temperature (Tg) of the polyol resin component and the isocyanate component contained in the urethane composition after curing can be lower than 0 °C. In the present application, the term "glass transition temperature after curing" can be the glass transition temperature measured for a cured product with a conversion rate of the NCO peak near 2250 cm -1 of 80% or more, and the conversion rate is determined by FT-IR analysis based on the cured state at room temperature and 30% to 70% relative humidity for 24 hours. The glass transition temperature can be measured after curing the polyol resin component and the isocyanate component (without any fillers).

[0076] When the glass transition temperature range is satisfied, even at low temperatures where a battery module or battery pack can be used, brittle properties can be ensured in a relatively short time, thereby ensuring impact resistance and vibration resistance properties. On the other hand, if the above range is not satisfied, the viscosity of the cured product may be too high or the thermal stability may decrease. In one example, the lower limit of the glass transition temperature of the urethane composition after curing can be about -70 °C or higher, -60 °C or higher, -50 °C or higher, -40 °C or higher, or about -30 °C or higher, and its upper limit can be about -5 °C or lower, -10 °C or lower, -15 °C or lower, or about -20 °C or lower

[0077] Furthermore, in the present application, additives can be used to ensure the use of the resin composition and the functions required according to its use. For example, considering the thermal conductivity, insulation, heat resistance (TGA analysis), etc. of the resin layer, the resin composition can contain a predetermined filler. The form or method of incorporating the filler into the resin composition is not particularly limited. For example, the filler can be used in the state where it is pre-incorporated into the main composition part and / or the curing agent composition part to form the urethane composition. Alternatively, during the process of mixing the main composition part and the curing agent composition part, the separately prepared filler can also be used by the method of mixing it together.

[0078] In one example, the filler can be a filler that has been pretreated by heat drying or the like for reducing the moisture content. For example, such a pretreatment can be carried out where the filler to be used is dried at a temperature of about 200 °C before being mixed with other components.

[0079] In one example, the moisture content of the filler can be 1,000 ppm or less. The moisture content can be measured using a Karl Fischer titrator (KR831) under conditions of 10% relative humidity and a deviation of 5.0 or less. At this time, the moisture content can be the average moisture content of all the fillers used in the resin composition. In the present application, fillers that meet the above conditions can also be selectively used, or after drying the fillers to be used in an oven at a temperature of about 200 °C, the moisture content of the fillers can also be adjusted to meet the said moisture content range. In another example, the upper limit of the filler moisture content can be 800 ppm or less, 600 ppm or less, or 400 ppm or less, and the lower limit can be 100 ppm or more, or 200 ppm or more.

[0080] In one example, the filler contained in the composition can be at least a thermally conductive filler. In the present application, the term thermally conductive filler can mean a material having a thermal conductivity of about 1 W / mK or more, about 5 W / mK or more, about 10 W / mK or more, or about 15 W / mK or more. Specifically, the thermal conductivity of the thermally conductive filler can be about 400 W / mK or less, about 350 W / mK or less, or about 300 W / mK or less. The types of available thermally conductive fillers are not particularly limited, but when considering insulation properties, etc., it can be a ceramic filler. For example, ceramic particles such as alumina, AlN (aluminum nitride), BN (boron nitride), silicon nitride, SiC, or BeO can be used. The shape or proportion of the filler is not particularly limited, and it can be appropriately adjusted considering the viscosity of the urethane-based composition, the possibility of sedimentation in the cured resin layer of the composition, the desired heat resistance or thermal conductivity, insulation properties, filling effect, or dispersibility, etc. Generally, the larger the size of the filler, the higher the viscosity of the composition containing it, and the higher the possibility of the filler precipitating in the resin layer. In addition, the smaller the size, the more likely the heat resistance is to increase. Therefore, considering the above points, fillers of appropriate types and sizes can be selected, and if necessary, two or more fillers can also be used. Considering the filling amount, it is advantageous to use spherical fillers, but considering the formation of a network structure or conductivity, fillers in the form of needle-like or flat forms can also be used. The thermal conductivity of the filler can be measured according to known methods, where the thermal conductivity of the filler can be measured by melting the filler and then making a sample.

[0081] In one example, the composition may include a thermally conductive filler having an average particle size in the range of 0.001 μm to 80 μm. In another example, the average particle size of the filler may be 0.01 μm or greater, 0.1 μm or greater, 0.5 μm or greater, 1 μm or greater, 2 μm or greater, 3 μm or greater, 4 μm or greater, 5 μm or greater, or about 6 μm or greater. In another example, the average particle size of the filler may be about 75 μm or less, about 70 μm or less, about 65 μm or less, about 60 μm or less, about 55 μm or less, about 50 μm or less, about 45 μm or less, about 40 μm or less, about 35 μm or less, about 30 μm or less, about 25 μm or less, about 20 μm or less, about 15 μm or less, about 10 μm or less, or about 5 μm or less. The average particle size can be measured using a PSA (particle size analysis) device. In one example, when the particles are arranged in order of size from 1 to 100, the average particle size may mean D(50), which is the particle size ranked 50th.

[0082] To obtain excellent heat dissipation performance, the use of a high content of thermally conductive filler can be considered. For example, relative to 100 parts by weight of the total resin components (i.e., the sum of the ester-based polyol resin content and the polyisocyanate content), the filler can be used in an amount of about 50 parts by weight to 2,000 parts by weight. In another example, a filler content exceeding the total resin components can be used. Specifically, relative to 100 parts by weight of the sum of the ester-based polyol resin content and the polyisocyanate content, the filler can be used in the following amounts: about 100 parts by weight or more, about 150 parts by weight or more, about 200 parts by weight or more, about 250 parts by weight or more, about 300 parts by weight or more, about 350 parts by weight or more, about 400 parts by weight or more, about 500 parts by weight or more, about 550 parts by weight or more, about 600 parts by weight or more, or about 650 parts by weight or more. In one example, when the filler is used within the above range, it can be distributed in the main composition part and the curing agent composition part in the same amount.

[0083] As described above, when a thermally conductive filler is used in a high content, the viscosity of the main composition part containing the filler or the curing agent composition part or the composition containing them may increase. As described above, when the viscosity of the resin composition is too high, the injection processability is poor, and thus the required physical properties of the resin layer may not be fully achieved throughout the resin layer. Considering this, it is preferable to use a low-viscosity component that can be a liquid or has sufficient fluidity as the resin component.

[0084] In one example, the viscosities of the ester-based polyol resin component and the polyisocyanate component can each be 10,000 cP or less. Specifically, the viscosity of the resin component can be 8,000 cP or less, 6,000 cP or less, 4,000 cP or less, 2,000 cP, or 1,000 cP or less. Preferably, the upper limit of the viscosity can be 900 cP or less, 800 cP or less, 700 cP or less, 600 cP or less, 500 cP or less, or 400 cP or less. Although not particularly limited, the lower limit of the viscosity of each resin component can be 50 cP or greater, or 100 cP or greater. If the viscosity is too low, the processability can be good, but due to the low molecular weight of the raw materials, the possibility of volatilization may increase, and the heat resistance / cold resistance, flame retardancy, and adhesion may deteriorate, and such disadvantages can be prevented by satisfying the lower limit range. The viscosity can be measured, for example, using a Brookfiled LV type viscometer at room temperature.

[0085] In addition to the above, multiple types of fillers can also be used. For example, carbon-based fillers such as graphite can be considered to be used to ensure the insulating properties of the cured resin layer of the resin composition. Alternatively, fillers such as pyrogenic silica, clay, or calcium carbonate can be used. The form or content ratio of the filler is not particularly limited, and it can be selected considering the viscosity of the resin composition, the possibility of sedimentation in the resin layer, thixotropy, insulating properties, filling effect, or dispersibility.

[0086] When using a filler as described above, the above problems may occur due to the moisture adsorbed on the filler. In such a case, a method of reducing the amount of filler used (which is a moisture increasing factor) can be considered, but when the amount of filler used is reduced, it is difficult to achieve the appropriate level of heat dissipation (thermal conductivity), withstand voltage resistance, heat resistance, etc. required in the resin layer for the battery module.

[0087] As a method of minimizing the adverse effects caused by moisture while ensuring an appropriate level of physical properties using a filler, a method of reducing the absolute moisture content adsorbed to the filler by pretreatment (e.g., heat drying) can be considered. In addition, in the present application, a predetermined dehumidifying agent can be used. When the composition contains a dehumidifying agent, the storage stability of the main composition part or the curing agent composition part can be ensured, and problems caused by moisture (e.g., surface curing or viscosity increase of the composition) and process errors generated can be solved.

[0088] The dehumidifying agent can be contained in the main composition part and / or the curing agent composition part. In particular, a dehumidifying agent can be used in the curing agent composition containing isocyanate that is susceptible to moisture.

[0089] In one example, the dehumidifying agent may be, for example, methyldiphenylethoxysilane, molecular sieve, p-toluenesulfonyl isocyanate (PTSI), acid anhydride esters (e.g., diethyl malonate and dimethyl succinate), (unsaturated) silane compounds represented by the following formula, and mixtures thereof.

[0090] [Formula]

[0091] R 1 SiR 2 (n) R 3 (3-n)

[0092] In the above formula, R 1 is a functional group having a carbon-carbon double bond bonded to a silicon atom. For example, R 1 may include an alkenyl group. The carbon number of the alkenyl group may be 2 to 20, 2 to 12, or 2 to 6. In one example, R 1 may be vinyl, allyl, propenyl, isopropenyl, butenyl, hexenyl, cyclohexenyl, or γ-methacryloxypropyl, etc.

[0093] R 2 and R 3 each independently represent hydrogen, an alkyl group, an aryl group, an aralkyl group, a hydroxyl group, a halogen, an amino group, or -R 4 R 5 wherein R 4 is an oxygen atom or a sulfur atom, and R 5 is an alkyl group, an aryl group, an aralkyl group, an acyl group, or -R 6 R 7 wherein R 6 may be an alkylene group or an alkylidene group, and R 7 may be an alkoxy group.

[0094] In the above formula, n is an integer from 1 to 3.

[0095] In one example, the unsaturated silane compound that can be used as the dehumidifying agent in this application may be vinyltrimethoxysilane, vinyltriethoxysilane, vinyltripropoxysilane, vinyltriisopropoxysilane, vinyltributoxysilane, vinyltripentyloxysilane, vinyltriphenoxysilane, vinyltriacetoxysilane, vinyltris(2-methoxyethoxy)silane, or a mixture of two or more thereof, but is not particularly limited thereto.

[0096] Since the dehumidifying agent reacts preferentially with moisture rather than the -NCO group of the isocyanate, the storage stability of the isocyanate can be improved.

[0097] In one example, based on 100 parts by weight of the polyol content or the isocyanate content, the dehumidifying agent can be included in a proportion of 50 parts by weight or less. For example, based on 100 parts by weight of the polyol content or the isocyanate content, the dehumidifying agent can be used in an amount of 45 parts by weight or less, 40 parts by weight or less, 35 parts by weight or less, or 30 parts by weight or less, and can be used in an amount of 1 part by weight or more, 3 parts by weight or more, or 5 parts by weight or more.

[0098] In another example, when the content of the curing agent composition or the main composition part is 100, the dehumidifying agent can be included in an amount of about 5% by weight or less. In this case, the polyol resin or the isocyanate resin can be included in an amount of about 5% to 15% by weight, and the filler can be used for other contents.

[0099] If necessary, the composition can further include a viscosity control agent for adjusting the viscosity, such as a thixotropic agent, a diluent, a dispersant, a surface treatment agent, or a coupling agent, for example, to increase or decrease the viscosity or to control the viscosity according to the shear force.

[0100] The thixotropic agent controls the viscosity of the resin composition according to the shear force, so that the process of manufacturing the battery module can be effectively carried out. As an available thixotropic agent, pyrogenic silica etc. can be exemplified.

[0101] Diluents or dispersants are generally used to reduce the viscosity of the resin composition, and any of various types known in the art can be used without limitation as long as it can exhibit the above functions.

[0102] The surface treatment agent is used for surface-treating the filler introduced into the resin layer, and any of various types known in the art can be used without limitation as long as it can exhibit the above functions.

[0103] For example, a coupling agent can be used to improve the dispersibility of a heat-conducting filler such as alumina, and any of various types known in the art can be used without limitation as long as it can exhibit the above functions.

[0104] In addition, the resin composition can further include a flame retardant or a flame retardant aid. In this case, known flame retardants can be used without any particular limitation, and for example, a solid-phase flame retardant or a liquid flame retardant can be applied. Flame retardants include, for example, organic flame retardants (such as melamine cyanurate) and inorganic flame retardants (such as magnesium hydroxide). When the amount of the filler filled in the resin layer is large, a liquid-type flame retardant material (TEP, triethyl phosphate, or TCPP, tris(1,3-chloro-2-propyl) phosphate, etc.) can also be used. In addition, a silane coupling agent that can be used as a flame retardant synergist can also be added.

[0105] The composition may include the above components and may be a solvent-based composition, a water-based composition, or a solvent-free composition. However, considering the convenience of the manufacturing process described below, a solvent-free composition may be suitable.

[0106] After curing, the composition of the present application may have physical properties suitable for the uses described below. Among the physical properties mentioned in this specification, when the measured temperature affects the physical properties, unless otherwise specified, the physical properties may be those measured at room temperature. In addition, the expression "after curing" related to the physical properties may be used with the same meaning as described above regarding the glass transition temperature.

[0107] In one example, the resin composition may have a predetermined adhesive strength (S 1 ) at room temperature after curing. Specifically, the adhesive strength of the resin layer may be about 150 gf / 10 mm or greater, 200 gf / 10 mm or greater, 250 gf / 10 mm or greater, 300 gf / 10 mm or greater, 350 gf / 10 mm or greater, or 400 gf / 10 mm or greater. When the adhesive strength satisfies the above range, appropriate impact resistance and vibration resistance can be ensured. The upper limit of the adhesive strength of the resin layer is not particularly limited and may be about 1,000 gf / 10 mm or less, 900 gf / 10 mm or less, 800 gf / 10 mm or less, 700 gf / 10 mm or less, 600 gf / 10 mm or less, or about 500 gf / 10 mm or less. When the adhesive strength is too high, there is a risk of tearing of the bag portion to which the cured composition is attached. Specifically, in the case of an impact in which the shape of the battery module is deformed due to an accident while driving a vehicle, when the battery cells are attached too firmly by the cured resin layer, when the bag is torn, dangerous materials inside the battery may be exposed or explode. The adhesive strength can be measured with respect to an aluminum bag according to the method disclosed in the following examples. For example, after cutting an aluminum bag used for manufacturing a battery cell into a width of about 10 mm, the resin composition is loaded on a glass plate, and the cut aluminum bag is loaded thereon such that the resin composition contacts the PET (poly(ethylene terephthalate)) side of the bag, and then the resin composition is cured at 25 °C and 50% RH for 24 hours. When peeling the aluminum bag with a tensile tester (texture analyzer) at a peeling angle of 180° and a peeling speed of 300 mm / min, the adhesive strength is measured.

[0108] In another example, even under high temperature / high humidity conditions, the adhesive strength of the resin composition after curing can be maintained at a relatively high level. Specifically, in the present application, the adhesive strength (S) measured by the same method after a high temperature / high humidity accelerated test conducted under predetermined conditions2 ) The ratio [(S 1 ) / S 2 × 100]% relative to the adhesive strength (S 1 ) measured at room temperature can be 70% or greater, or 80% or greater. In one example, the high temperature / high humidity accelerated test can be measured after storing a sample identical to the sample used for measuring the room temperature adhesive strength for 10 days under conditions of a temperature of 40°C to 100°C and a humidity of 75% RH or greater. When the adhesive strength and relationship are satisfied, excellent adhesive durability can be maintained even when the usage environment of the battery module changes.

[0109] In one example, the resin composition can have excellent heat resistance after curing. In this regard, when measuring thermogravimetric analysis (TGA) of the cured product of only the resin component in a state without filler, the 5% weight loss temperature of the composition of the present application can be 120°C or higher. In addition, when measuring thermogravimetric analysis (TGA) of the cured product of the resin composition in a state containing filler, the 800°C balance of the composition of the present application can be 70% by weight or greater. In another example, the 800°C balance can be about 75% by weight or greater, about 80% by weight or greater, about 85% by weight or greater, or about 90% by weight or greater. In another example, the 800°C balance can be about 99% by weight or less. At this time, thermogravimetric analysis (TGA) can be measured in a nitrogen (N 3 ) atmosphere at a rate of 60 cm 2 / min with a heating rate of 20°C / min in the range of 25°C to 800°C. By controlling the type and / or content of the resin and / or filler, heat resistance characteristics related to thermogravimetric analysis (TGA) can be ensured.

[0110] In one example, the resin composition can have excellent electrical insulation after curing. In the battery module structure described below, when the resin layer exhibits a predetermined electrical insulation, the performance of the battery module can be maintained and stability can be ensured. For example, as measured according to ASTM D149, the dielectric breakdown voltage of the cured product of the resin composition can be about 10 kV / mm or greater, 15 kV / mm or greater, or 20 kV / mm or greater. The higher the value of the dielectric breakdown voltage, the more excellent the insulation of the resin layer, and thus it is not particularly limited, but considering the composition of the resin layer, etc., it can be about 50 kV / mm or less, 45 kV / mm or less, 40 kV / mm or less, 35 kV / mm or less, or 30 kV / mm or less. For example, by adjusting the content of the above-mentioned filler and resin components, the dielectric breakdown voltage within the above range can be ensured.

[0111] In another example of the present application, the present application relates to a battery module. The module includes a module housing and battery cells. The battery cells can be accommodated in the module housing. One or more battery cells may be present in the module housing, and a plurality of battery cells can be accommodated in the module housing. The number of battery cells accommodated in the module housing is adjusted according to applications and the like, and there is no particular limitation. The battery cells accommodated in the module housing can be electrically connected to each other.

[0112] The module housing may include at least side walls and a bottom plate that form an internal space in which the battery cells can be accommodated. In addition, the module housing may further include a top plate for sealing the internal space. The side walls, the bottom plate, and the top plate are integrally formed with each other, or separate side walls, bottom plates, and / or top plates are assembled so that the module housing can be formed. The shape and size of such a module housing are not particularly limited and can be appropriately selected according to applications or the type and number of battery cells accommodated in the internal space.

[0113] Here, since at least two plates constitute the module housing, the terms "top plate" and "bottom plate" are terms having relative concepts for distinguishing them. That is, it does not mean that in the actual use state, the top plate must be present at the upper part and the bottom plate must be present at the lower part.

[0114] Figure 2 FIG. showing an exemplary module housing 10, which is an example of a box-shaped module housing 10 including a bottom plate 10a and four side walls 10b. The module housing 10 may further include a top plate 10c for sealing the internal space.

[0115] Figure 3 FIG. is a schematic view of the module housing 10 in which the battery cells 20 are accommodated as viewed from above. Figure 2 of the module housing 10.

[0116] Holes can be formed in the bottom plate, side walls, and / or top plate of the module housing. When forming a resin layer by an injection process, the holes can be injection holes for injecting a material (i.e., a resin composition) for forming the resin layer, as described below. The shape, number, and position of the holes can be adjusted in consideration of the injection efficiency of the material for forming the resin layer. In one example, the holes can be formed at least in the bottom plate and / or the top plate.

[0117] In one example, the holes can be formed at about 1 / 4 to 3 / 4 points or about 3 / 8 to 7 / 8 points or substantially in the middle of the total length of the side walls, bottom plate, or top plate. By injecting the resin composition through the injection holes formed at this point, the resin layer can be injected to have a wide contact area. As Figure 4As shown, the 1 / 4, 3 / 4, 3 / 8, or 7 / 8 points are the ratios of the distance A from the end face E (such as the bottom plate, etc.) to the hole formation position to the total length L. The end face E for forming the length L and the distance A can be any end face E as long as the length L and the distance A are measured from the same end face E. In Figure 4 In [reference], the injection hole 50a is in the form of being located in the approximate middle part of the bottom plate 10a.

[0118] The size and shape of the injection hole are not particularly limited and can be adjusted in consideration of the injection efficiency of the resin layer material to be described below. For example, the hole can have a circular shape, an elliptical shape, a polygonal shape (such as a triangle or a square), or an amorphous shape. The number and spacing of the injection holes are not particularly limited and can be adjusted so that the resin layer can have a wide contact area with the bottom plate, etc., as described above.

[0119] Observation holes (such as Figure 4 50b in [reference]) can be formed at the ends of the top plate and the bottom plate where the injection holes are formed. For example, when injecting the material of the resin layer through the injection holes, such observation holes can be formed to observe whether the injected material is well injected to the ends of the side wall, the bottom plate, or the top plate. The position, shape, size, and number of the observation holes are not particularly limited as long as they are formed so that it can be determined whether the injected material is properly injected.

[0120] The module housing can be a heat-conducting housing. The term heat-conducting housing means a housing in which the thermal conductivity of the entire housing is 10 W / mK or greater, or includes at least a part having the thermal conductivity as described above. For example, at least one of the side wall, the bottom plate, and the top plate as described above can have the above thermal conductivity. In another example, at least one of the side wall, the bottom plate, and the top plate can include a part having the thermal conductivity. For example, as described below, the battery module of the present application can include a first filler-containing cured resin layer in contact with the top plate and the battery cell; and a second filler-containing cured resin layer in contact with the bottom plate and the battery cell, where at least the second filler-containing cured resin layer can be a heat-conducting resin layer, and thus it can be said that at least the bottom plate can have heat conductivity or can include a heat-conducting part.

[0121] Here, the thermal conductivity of the thermally conductive top plate, bottom plate, side wall, or thermally conductive portion may be 20 W / mK or greater, 30 W / mK or greater, 40 W / mK or greater, 50 W / mK or greater, 60 W / mK or greater, 70 W / mK or greater, 80 W / mK or greater, 90 W / mK or greater, 100 W / mK or greater, 110 W / mK or greater, 120 W / mK or greater, 130 W / mK or greater, 140 W / mK or greater, 150 W / mK or greater, 160 W / mK or greater, 170 W / mK or greater, 180 W / mK or greater, 190 W / mK or greater, or about 195 W / mK or greater. The higher the value of the thermal conductivity, the more advantageous it is from the viewpoint of heat dissipation characteristics of the module, etc., and the upper limit is not particularly limited. In one example, the thermal conductivity may be about 1,000 W / mK or less, 900 W / mK or less, 800 W / mK or less, 700 W / mK or less, 600 W / mK or less, 500 W / mK or less, 400 W / mK or less, 300 W / mK or less, or 250 W / mK or less, but is not limited thereto. The type of material exhibiting the above-described thermal conductivity is not particularly limited, and includes, for example, metal materials such as aluminum, gold, pure silver, tungsten, copper, nickel, or platinum. The module housing may be entirely composed of the above-described thermally conductive material, or at least a part of the module housing may be a part composed of the thermally conductive material. Therefore, the module housing may have a thermal conductivity within the above range, or include at least a part having the aforementioned thermal conductivity.

[0122] In the module housing, the portion having a thermal conductivity within the above range may be a portion in contact with the resin layer and / or insulating layer described below. In addition, the portion having the thermal conductivity may be a portion in contact with a cooling medium such as cooling water. When it has such a structure, the heat generated by the battery cells can be effectively discharged to the outside.

[0123] In addition, the type of battery cells accommodated in the module housing is not particularly limited, and various known battery cells can be applied. In one example, the battery cells may be pouch type. Referring to Figure 5 , the pouch type battery cell 100 generally may include an electrode assembly, an electrolyte, and a pouch outer material.

[0124] Figure 5 To schematically show an exploded perspective view of the configuration of an exemplary pouch type cell, and Figure 6 For Figure 5 The combined perspective view of the configuration of.

[0125] The electrode assembly 110 included in the pouch-type battery cell 100 may be in such a form that at least one positive electrode plate and at least one negative electrode plate are provided with respective separators interposed therebetween. The electrode assembly 110 may be a wound type in which one positive electrode plate and one negative electrode plate are wound together with a separator, or a stacked type in which a plurality of positive electrode plates and a plurality of negative electrode plates are alternately laminated with respective separators interposed therebetween.

[0126] The pouch exterior material 120 may be configured in a form equipped with, for example, an outer insulating layer, a metal layer, and an inner adhesive layer. Such exterior material 120 protects internal components such as the electrode assembly 110 and the electrolyte, supplements the electrochemical characteristics of the electrode assembly 110 and the electrolyte, and takes into account heat dissipation and the like. Such a metal thin film may be interposed between insulating layers formed of an insulating material to ensure electrical insulation from components such as the electrode assembly 110 and the electrolyte or other components outside the pouch-type battery cell 100. In addition, the pouch may further include, for example, a polymer resin layer (substrate), such as PET.

[0127] In one example, the exterior material 120 may include an upper pouch 121 and a lower pouch 122, and a concave inner space I may be formed in at least one of the upper pouch 121 and the lower pouch 122. The electrode assembly 110 may be accommodated in the inner space I of the pouch. Sealing portions S are provided on the outer peripheral surfaces of the upper pouch 121 and the lower pouch 122 respectively, and these sealing portions S are joined to each other so that the inner space accommodating the electrode assembly 110 can be sealed.

[0128] Each electrode plate of the electrode assembly 110 is provided with an electrode tab, and one or more electrode tabs may be connected to an electrode lead. The electrode lead may be interposed between the sealing portions S of the upper pouch 121 and the lower pouch 122 and exposed to the outside of the exterior material 120 to serve as an electrode terminal of the pouch-type battery cell 100.

[0129] The shape of the pouch-type cell as described above is merely an example, and the battery cells applied in this application are not limited to the above types. In this application, known pouch-type cells or other types of cells in various shapes can be used as battery cells.

[0130] The battery module of this application may further include a resin layer. Specifically, the battery module of this application may include a cured resin layer in which a composition containing a filler is cured. The cured resin layer may be formed of the urethane-based composition as described above.

[0131] As a resin layer, the battery module may include a first filler-containing cured resin layer that contacts the top plate and the battery cells; and a second filler-containing cured resin layer that contacts the bottom plate and the battery cells. One or more of the first filler-containing cured resin layer and the second filler-containing cured resin layer may include a cured product of the urethane composition as described above, and thus have the predetermined adhesive force, cold resistance, heat resistance, and insulation as described above. In addition, the first filler-containing cured resin layer and the second filler-containing cured resin layer may have the following characteristics.

[0132] In one example, the resin layer may be a thermally conductive resin layer. In this case, the thermal conductivity of the thermally conductive resin layer may be about 1.0 W / mK or greater, 1.5 W / mK or greater, about 2 W / mK or greater, 2.5 W / mK or greater, 3 W / mK or greater, 3.5 W / mK or greater, or 4 W / mK or greater. The thermal conductivity may be 50 W / mK or less, 45 W / mK or less, 40 W / mK or less, 35 W / mK or less, 30 W / mK or less, 25 W / mK or less, 20 W / mK or less, 15 W / mK or less, 10 W / mK or less, 5 W / mK or less, 4.5 W / mK or less, or about 4.0 W / mK or less. When the resin layer is the thermally conductive resin layer as described above, the bottom plate, the top plate, and / or the side wall to which the resin layer is attached may be the part with the thermal conductivity of 10 W / mK or greater as described above. At this time, the module housing part showing the thermal conductivity may be the part in contact with a cooling medium such as cooling water. The thermal conductivity of the resin layer is measured using a known hot disk device, which is a value measured according to, for example, ASTM D5470 standard or ISO22007-2 standard. The thermal conductivity of such a resin layer can be ensured, for example, by appropriately adjusting the filler and its content included in the resin layer as described above.

[0133] In one example, in the battery module, the thermal resistance of the resin layer or the battery module to which the resin layer is applied may be 5 K / W or less, 4.5 K / W or less, 4 K / W or less, 3.5 K / W or less, 3 K / W or less, or about 2.8 K / W. When the resin layer or the battery module to which the resin layer is applied is adjusted to exhibit a thermal resistance within the above range, excellent cooling efficiency or heat dissipation efficiency can be ensured. The measurement of the thermal resistance can be performed as follows: while driving the battery module, attach temperature sensors according to the cell positions on the module, and calculate the thermal resistance based on the temperatures measured by the sensors. The method for measuring the thermal resistance is not particularly limited, and for example, the thermal resistance can be measured according to ASTM D5470 standard or ISO 22007-2 standard.

[0134] In one example, the resin layer can be a resin layer formed to maintain durability even in a predetermined thermal shock test. The thermal shock test can be performed in a manner known in the art. For example, when one cycle consists of holding the battery module at a low temperature of -40°C for 30 minutes and then holding it again for 30 minutes after increasing the temperature to 80°C, it can be a resin layer that does not peel or crack from the module housing or battery cells of the battery module after 100 cycles of the thermal shock test. For example, when the battery module is applied to a product (e.g., an automobile) that requires a long shelf life (e.g., about 15 years or more in the case of an automobile), the same level of performance as above may be required to ensure durability.

[0135] In one example, the resin layer can be a flame-retardant resin layer. In this application, the term flame-retardant resin layer can mean a resin layer that shows a V-0 rating in the UL 94V test (vertical burn test). This can ensure stability against fire and other accidents that may occur in the battery module.

[0136] In one example, the specific gravity of the resin layer can be 5 or less. In another example, the specific gravity can be 4.5 or less, 4 or less, 3.5 or less, or 3 or less. A resin layer showing a specific gravity within this range is beneficial for manufacturing a lightweight battery module. The lower the value of the specific gravity, the more beneficial it is for the weight reduction of the module, so the lower limit is not particularly limited. For example, the specific gravity can be about 1.5 or greater, or 2 or greater. The components added to the resin layer can be adjusted so that the resin layer exhibits a specific gravity within the above range. For example, when adding fillers, methods such as applying fillers that can ensure the desired thermal conductivity even at a low specific gravity (if possible, i.e., fillers with a low specific gravity or surface-treated fillers) can be used.

[0137] In one example, if possible, it is preferred that the resin layer does not contain volatile substances. For example, the proportion of non-volatile components in the resin layer can be 90 wt% or greater, 95 wt% or greater, or 98 wt% or greater. Here, the non-volatile components and their proportion can be specified in the following manner. That is, the non-volatile components can be defined as the remaining part after holding the resin layer at 100°C for about 1 hour. Therefore, the proportion of non-volatile components can be measured based on the initial weight of the resin layer and the proportion after holding the resin layer at 100°C for about 1 hour.

[0138] In one example, it is beneficial for the resin layer to have a low shrinkage rate during or after the curing process. This can prevent the occurrence of peeling or voids that may occur during the manufacturing or use of the module. The shrinkage rate can be appropriately adjusted within a range that can exhibit the above effects, and can be, for example, less than 5%, less than 3%, or less than about 1%. The lower the value of the shrinkage rate, the more beneficial the shrinkage rate, so the lower limit is not particularly limited.

[0139] In one example, the resin layer may have a low coefficient of thermal expansion (CTE) to prevent the occurrence of peeling or voids that may occur during the manufacture or use of the module. The coefficient of thermal expansion may be, for example, less than 300 ppm / K, less than 250 ppm / K, less than 200 ppm / K, less than 150 ppm / K, or less than about 100 ppm / K. The lower the value of the coefficient of thermal expansion, the more advantageous the coefficient, and thus the lower limit is not particularly limited. The method for measuring the coefficient of thermal expansion is not particularly limited. For example, it is measured using a TMA (Thermomechanical Analyzer) in the expansion mode and under a load of 0.05 N in the range of -40°C to 125°C at a rate of 5°C / minute, where the coefficient of thermal expansion can be measured in a manner that determines the rate of change of length within a specified temperature range based on the modified length.

[0140] In one example, to impart good durability or shock resistance to the battery module, the resin layer may have an appropriate level of tensile strength. For example, the resin layer may be configured to have a Young's modulus of about 1.0 MPa or greater. The Young's modulus may be, for example, the slope value measured in the tensile mode at low temperature (about -40°C), room temperature (about 25°C), and high temperature (about 80°C) for each point in the range of -40°C to 80°C. The higher the temperature, the lower the measured Young's modulus. For example, the Young's modulus of the resin layer of the present application may be 1.0 Mpa or greater, and more specifically, in the range of 10 Mpa to 500 Mpa. When the Young's modulus is less than the above range, the function of fixing the large weight unit is not good; while when it is too large, the brittle characteristic is strong, so that cracks may occur in the case of impacts such as vehicle collisions.

[0141] In one example, it may be advantageous for the resin layer to exhibit appropriate hardness. For example, if the hardness of the resin layer is too high, it may adversely affect the reliability due to the brittle characteristic of the resin layer. When this is taken into account, by controlling the hardness of the resin layer, shock resistance and vibration resistance can be ensured, and the durability of the product can be ensured. The Shore A hardness of the resin layer may be, for example, less than 100, 99 or less, 98 or less, 95 or less, or 93 or less, or the Shore D hardness may be, for example, less than about 80, about 70 or less, about 65 or less, or about 60 or less. The lower limit of the hardness is not particularly limited. For example, the Shore A hardness may be 60 or greater, or the Shore 00 hardness may be 5 or greater, or about 10 or greater. The hardness within the above range can be ensured by controlling the content of the filler, etc. The Shore hardness can be measured using various types of hardness testers (e.g., Shore A hardness tester) according to known methods. Known methods are ASTM D2240, etc.

[0142] By forming a cured resin layer satisfying the above-described characteristics in the battery module as described above, a battery module having excellent durability against external shock or vibration can be provided.

[0143] In the battery module of the present application, at least one of the side wall, bottom plate, and top plate in contact with the resin layer may be the above-described heat-conductive side wall, bottom plate, or top plate. On the other hand, in the present specification, the term "contact" may also mean a situation where, for example, the top plate, bottom plate, and / or side wall or battery cell is in direct contact with the resin layer, or there are other elements such as an insulating layer therebetween. In addition, the resin layer in contact with the heat-conductive side wall, bottom plate, or top plate may be in thermal contact with the target. At this time, thermal contact may mean a state where the resin layer is in direct contact with the bottom plate or the like, or there are other elements such as an insulating layer as described below between the resin layer and the bottom plate or the like, but the other elements do not impede heat transfer from the battery cell to the resin layer and from the resin layer to the bottom plate or the like. Here, the phrase "does not impede heat transfer" means a situation where even when there are other elements (for example, an insulating layer or a guide portion as described below) between the resin layer and the bottom plate or the like, the total thermal conductivity of the other elements and the resin layer is about 1.5 W / mK or greater, about 2 W / mK or greater, 2.5 W / mK or greater, 3 W / mK or greater, 3.5 W / mK or greater, or 4 W / mK or greater, or even when there are other elements, the total thermal conductivity of the resin layer and the bottom plate or the like in contact therewith is also included in this range. The thermal conductivity of the thermal contact may be 50 W / mK or less, 45 W / mK or less, 40 W / mK or less, 35 W / mK or less, 30 W / mK or less, 25 W / mK or less, 20 W / mK or less, 15 W / mK or less, 10 W / mK or less, 5 W / mK or less, 4.5 W / mK or less, or about 4.0 W / mK or less. When there are other elements, this thermal contact can be achieved by controlling the thermal conductivity and / or thickness of the other elements.

[0144] The heat-conductive resin layer may be in thermal contact with the bottom plate or the like and may also be in thermal contact with the battery cell. By adopting such a structure, various fastening members or cooling devices of the module previously required in the configuration of a general battery module or a battery pack as an assembly of such modules are greatly reduced, and at the same time, a module in which heat dissipation characteristics are ensured and more battery cells are accommodated per unit volume can be achieved. Therefore, the present application can provide a battery module that is more compact and lighter while having high power.

[0145] Figure 7 FIG. is an exemplary cross-sectional view of a battery module. In Figure 7 the module may be in a form that includes a housing, the housing 10 including a side wall 10b and a bottom plate 10a; a plurality of battery cells 20 accommodated in the housing; and a resin layer 30 in contact with both the battery cells 20 and the housing.Figure 7 This is a diagram of the resin layer 30 existing on the side of the bottom plate 10a. However, the battery module of the present application may also include a resin layer located on the top plate side in the same form. Figure 7

[0146] In the above structure, the bottom plate in contact with the resin layer 30 and the like may be the heat-conducting bottom plate and the like as described above.

[0147] Relative to the total area of the bottom plate and the like, the contact area between the resin layer and the bottom plate and the like may be about 70% or more, about 75% or more, about 80% or more, about 85% or more, about 90% or more, or about 95% or more. There is no particular limitation on the upper limit of the contact area, and it may be, for example, 100% or less, or less than about 100%.

[0148] When the top plate or the bottom plate is heat-conducting and the cured resin layer in contact with it is also heat-conducting, the heat-conducting part or the heat-conducting bottom plate and the like may be the part in contact with the cooling medium (for example, cooling water). That is, as Figure 7 schematically shown, through the above structure, heat H can be easily discharged to the bottom plate and the like, and by bringing the bottom plate and the like into contact with the cooling medium CW, heat release can be easily carried out even in a simpler structure.

[0149] The thickness of each of the first cured resin layer and the second cured resin layer may be in the range of, for example, about 100 μm to 5 mm, or in the range of about 200 μm to 5 mm. In the structure of the present application, considering the desired heat dissipation characteristics or durability, the thickness of the resin layer can be set to an appropriate thickness. The thickness may be the thickness of the thinnest part, the thickest part, or the average thickness of the resin layer.

[0150] As Figure 7 shown, on at least one surface inside the module housing (for example, the surface of the bottom plate 10a in contact with the resin layer 30), there may also be a guiding portion 10d that can guide the accommodated battery cells 20. At this time, the shape of the guiding portion 10d is not particularly limited, and an appropriate shape can be adopted in consideration of the shape of the battery cells to be applied. The guiding portion 10d can be integrally formed with the bottom plate and the like, or can be separately attached to it. Considering the above heat contact, the guiding portion 10d can be formed using a heat-conducting material (for example, a metal material such as aluminum, gold, pure silver, tungsten, copper, nickel, or platinum). In addition, although not shown in the figure, there may also be an interleaf or an adhesive layer between the accommodated battery cells 20. Here, the interleaf can act as a buffer when the battery cells are charged and discharged.

[0151] In one example, the battery module may further include an insulating layer between the module housing and the battery cells or between the resin layer and the module housing. Figure 8 ​Schematically shows a situation where an insulating layer 40 is formed between a resin layer 30 and a guiding portion 10d formed on a bottom plate 10a of a housing. By adding the insulating layer, problems such as an electrical short - circuit phenomenon or a fire caused by contact between the unit and the housing due to an impact that may occur during use can be prevented. The insulating layer can be formed using an insulating sheet having high insulation and thermal conductivity, or can be formed by applying or injecting a material exhibiting insulating properties. For example, in the method for manufacturing a battery module described below, the process of forming the insulating layer can be carried out before injecting the resin composition. A so - called TIM (thermal interface material) etc. can be applied when forming the insulating layer. Alternatively, the insulating layer can be formed of an adhesive material, and for example, the insulating layer can also be formed using a resin layer having little or no filler (such as a thermal conductive filler). As resin components that can be used to form the insulating layer, acrylic resins, PVC (poly(vinyl chloride)), olefin resins (such as PE (polyethylene)), epoxy resins, silicone, or rubber components (such as EPDM (ethylene propylene diene monomer) rubber) etc. can be exemplified, but are not limited thereto. The insulation breakdown voltage of the insulating layer measured according to ASTM D149 can be about 5 kV / mm or greater, about 10 kV / mm or greater, about 15 kV / mm or greater, 20 kV / mm or greater, 25 kV / mm or greater, or 30 kV / mm or greater. The higher the value of the dielectric breakdown voltage, the better the insulation performance exhibited, so there is no particular limitation. For example, the dielectric breakdown voltage of the insulating layer can be about 100 kV / mm or less, 90 kV / mm or less, 80 kV / mm or less, 70 kV / mm or less, or 60 kV / mm or less. The thickness of the insulating layer can be set within an appropriate range considering the insulation characteristics and thermal conductivity of the insulating layer, and for example, can be about 5 μm or greater, 10 μm or greater, 20 μm or greater, 30 μm or greater, 40 μm or greater, 50 μm or greater, 60 μm or greater, 70 μm or greater, 80 μm or greater, or about 90 μm or greater. In addition, the upper limit of the thickness is not particularly limited, and can be, for example, about 1 mm or less, about 200 μm or less, 190 μm or less, 180 μm or less, 170 μm or less, 160 μm or less, or 150 μm or less.

[0152] In another example of the present application, the present application relates to a method for manufacturing a battery module (such as the above - mentioned battery module).

[0153] The manufacturing method of the present application can include the following steps: injecting a resin composition into the above - mentioned module housing; accommodating battery cells in the module housing; and curing the resin composition to form a resin layer.

[0154] The order of the steps of injecting the resin composition into the module housing and placing the battery cells in the module housing is not particularly limited. For example, the resin composition can be first injected into the module housing, and then the battery cells can be placed in this state; or the battery cells can be first placed in the module housing, and then the resin composition can be injected therein.

[0155] As the resin composition, the above resin composition can be used.

[0156] The method of injecting the resin composition into the module housing is not particularly limited, and known methods can be applied. For example, the resin composition can be injected by pouring the resin composition into the opening of the module housing, or the method of injecting the resin composition through the above injection holes formed in the module housing, the method of applying the resin composition to both the battery cells and the battery module, etc. can be applied. For proper fixation, the injection process can also be carried out while continuously vibrating the battery module or the battery cells.

[0157] The manner of placing the battery cells in the module housing injected with the resin composition or in the module housing before injecting the composition is not particularly limited.

[0158] Considering the desired arrangement, etc., the placement of the battery cells can be carried out by arranging the battery cells at appropriate positions in the module housing. In addition, when there is a cassette structure, this step can be carried out by placing the battery cells at appropriate positions in the cassette structure or inserting the cassette structure in which the battery cells are located into the module housing.

[0159] After placing the battery cells therein, the adhesion between the battery cells or the adhesion between the battery cells and the module housing can be achieved by curing the injected resin composition. The manner of curing the resin composition is not particularly limited. In one example, when using this composition, the resin composition can be cured by holding the resin composition at room temperature for a predetermined time. The curing can also be accelerated by applying heat for a certain period of time at a level that does not impair the thermal stability of the cells. For example, by applying heat at a temperature below 60 °C, more specifically, in the range of about 30 °C to 50 °C, before curing or during the curing process, or before placing the battery cells or during the placement process, the takt time can be reduced and the processability can be improved. The conversion rate of the cured product that can achieve the adhesion between the battery cells or the adhesion between the battery cells and the module housing can be at least 80% or more as described above.

[0160] In another example of the present application, the present application relates to a battery pack, for example, a battery pack including two or more of the battery modules described above. In the battery pack, the battery modules may be electrically connected to each other. The method of electrically connecting two or more battery modules to form a battery pack is not particularly limited, and all known methods can be applied thereto.

[0161] The present application also relates to a device including a battery module or a battery pack. Examples of such a device may include, but are not limited to, an automobile (such as an electric vehicle), and may be a device for all applications that require a secondary battery as power. In addition, the method of constructing an automobile using a battery module or a battery pack is not particularly limited, and general methods known in the relevant field can be applied.

[0162] Advantageous Effects

[0163] According to an example of the present application, a urethane composition capable of preventing a decrease in processability or storage stability caused by moisture introduced into the composition can be provided. The cured composition can effectively fix the battery cells in the module housing and improve heat dissipation of the battery module. Description of the Drawings

[0164] Figure 1 An example of determining the amorphous property or sufficiently low crystallizability of an ester-based polyol according to an example of the present application is shown.

[0165] Figure 2 An exemplary module housing that can be applied in the present application is shown.

[0166] Figure 3 A form in which battery cells are accommodated in the module housing is schematically shown.

[0167] Figure 4 An exemplary bottom plate in which an injection hole and an observation hole are formed is schematically shown.

[0168] Figure 5 and 6 An exemplary battery pouch that can be used as a battery cell is schematically shown.

[0169] Figure 7 and 8 The structure of an exemplary battery module is schematically shown.

[0170] The reference numerals and symbols related to the drawings are as follows.

[0171] 10: Module housing

[0172] 10a: Bottom plate

[0173] 10b: Side wall

[0174] 10c: Top plate

[0175] 10d: Guide portion

[0176] 20: Battery cell

[0177] 30: Resin layer

[0178] 50a: Injection hole

[0179] 50b: Observation hole

[0180] 40: Insulation layer

[0181] 100: Pouch-type battery cell

[0182] 110: Electrode assembly

[0183] 120: Outer material

[0184] 121: Upper pouch

[0185] 122: Lower pouch

[0186] S: Sealing portion Detailed implementation manners

[0187] In the following, the battery module of the present application will be described with reference to the embodiments and comparative examples, but the scope of the present application is not limited by the following scope.

[0188] Evaluation method

[0189] 1. Storage stability

[0190] Measure the viscosity of the curative composition portion containing isocyanate prepared in the measurement examples and comparative examples. Specifically, determine the viscosity two months after mixing the components contained in the curative composition portion. If the viscosity after 2 months is too high compared to the initial viscosity of the prepared composition (i.e., in the case of exceeding 400,000 cP), it is evaluated as unqualified. If the viscosity shows an appropriate level of increase (i.e., in the case of about 100,000 cP to 400,000 cP), it is evaluated as qualified. The fact that the viscosity after 2 months increases excessively relative to the initial viscosity under the condition that external factors such as heat have less influence on the composition can be regarded as the deterioration of storage stability caused by moisture penetration. That is, in the case of being evaluated as unqualified, it is considered that moisture penetrates during the two-month storage period, and at the same time, the moisture reacts with the isocyanate component, resulting in an increase in viscosity. The viscosity is measured using a rheological property measuring device (ARES) at room temperature and a shear rate condition of 0.01 / second to 10.0 / second. The viscosity described in Table 1 below is the viscosity at a shear rate of 2.5 / second.

[0191] 2. Thermal conductivity

[0192] Measure the thermal conductivity of the cured product composed of the following according to the ISO 22007-2 standard.

[0193] Examples and comparative examples

[0194] Example 1

[0195] Polyol: A resin is used in a predetermined amount in the main composition (the viscosity measured by a Brookfield LV type viscometer is about 280 cP), and the resin contains a polyol having a repeating unit number (m in Formula 2) of about 1 to 3 and containing 1,4-butanediol as a polyol-derived unit (Y in Formula 2) as a caprolactone-based polyol represented by the above Formula 2.

[0196] Isocyanate: A mixture of HDI (hexamethylene diisocyanate) and HDI trimer is used in the curative composition (the viscosity measured by a Brookfield LV type viscometer is 170 cP). At this time, adjust the amount of the isocyanate compound used so that the NCO index is about 100.

[0197] Filler: Alumina is used. Its content is adjusted at a ratio of 500 parts by weight relative to the total of 100 parts by weight of the polyol content and the isocyanate content, and the alumina is distributed and formulated in the main composition part and the curing agent composition part in the same amount. In the case of the formulated filler, the filler is dried (moisture treatment) in an oven at 200 °C for 12 hours or longer before formulation and then used.

[0198] Humectant: VTMO (vinyltrimethoxysilane) is used. Its content is at a ratio of 20 parts by weight relative to the total of 100 parts by weight of the polyol content and the isocyanate content, and the VTMO is distributed and formulated in the main composition part and the curing agent composition part in the same amount.

[0199] Catalyst: Dibutyltin dilaurate (DBTDL) is used in a predetermined amount.

[0200] Examples 2 to 4 and Comparative Examples 1 to 2

[0201] The same method as in Example 1 is used, except that the composition is changed to that shown in Table 1 below.

[0202] [Table 1]

[0203]

[0204] In Table 1, by comparing the examples and comparative examples, when the humectant is included in the curing agent composition part, the viscosity after two months is 100,000 to 400,000 cP compared to the initial viscosity, showing excellent storage stability. However, when the humectant is not included in the curing agent composition part, the viscosity after two months is greater than 400,000 cP compared to the initial viscosity, showing poor storage stability.

Claims

1. A two-component urethane composition, comprising: A main composition part; A curing agent composition part; A filler; and A dehumidifying agent, wherein the main composition part comprises an ester-based polyol resin, and the curing agent composition part comprises a polyisocyanate, wherein the curing agent composition part comprises the filler and the dehumidifying agent, wherein the ester-based polyol resin comprises a caprolactone-based polyol, wherein the ester-based polyol resin has a viscosity of 100 cP or greater and 900 cP or less at room temperature, wherein the ester-based polyol resin is an amorphous polyol in which no crystallization temperature Tc and melting temperature Tm are observed in differential scanning calorimetry DSC analysis, or the melting temperature Tm of the ester-based polyol resin is lower than 15 °C, wherein the polyisocyanate comprises a non-aromatic polyisocyanate, wherein the polyisocyanate consists of a polyisocyanate having a viscosity of 100 cP or greater and 900 cP or less at room temperature, wherein the filler is included in an amount of 150 parts by weight to 2,000 parts by weight relative to the total content of 100 parts by weight of the ester-based polyol resin and the polyisocyanate, wherein the filler is a thermally conductive filler, wherein the dehumidifying agent is selected from methyl diphenyl ethoxysilane, a silane compound represented by the following formula, and mixtures thereof: [Formula] R 1 SiR 2 (n) R 3 (3-n ) wherein, R 1 is a functional group having an inter-carbon double bond bonded to a silicon atom, R 2 and R 3 each independently represent a hydroxyl group, a halogen, an amino group or -R 4 R 5 wherein R 4 is an oxygen atom or a sulfur atom, and R 5 is an alkyl group, an aryl group, an aralkyl group, an acyl group or -R 6 R 7 wherein R 6 is an alkylene group, and R 7 is an alkoxy group, and n is an integer from 1 to 3.

2. The two-component urethane composition according to claim 1, wherein the main composition part comprises the filler and the dehumidifying agent.

3. The two-component urethane composition according to claim 1, wherein the filler comprises alumina, aluminum nitride AlN, boron nitride BN, silicon nitride, SiC or BeO.

4. The two-component urethane composition according to claim 1, wherein the dehumidifying agent is further selected from molecular sieves, p-toluenesulfonyl isocyanate PTSI, acid anhydride esters, and mixtures thereof.

5. The two-component urethane composition according to claim 1, wherein the silane compound comprises vinyltrimethoxysilane, vinyltriethoxysilane, vinyltripropoxysilane, vinyltriisopropoxysilane, vinyltributoxysilane, vinyltripentoxysilane, vinyltriphenoxysilane, vinyltriacetoxysilane, or vinyltris(2-methoxyethoxy)silane.

6. The two-component urethane composition according to claim 1, wherein the glass transition temperature Tg of the mixture of the ester-based polyol resin and the polyisocyanate after curing is lower than 0 °C.

7. The two-component urethane composition according to claim 1, wherein the viscosity of the ester-based polyol resin at room temperature is 100 cP or greater and 800 cP or less.

8. The two-component urethane composition according to claim 1, wherein the ester-based polyol resin is represented by the following formula 1 or 2: [Formula 1] [Formula 2] wherein, X is a carboxylic acid-derived unit, Y is a polyol-derived unit, n is a number in the range of 2 to 10, and m is a number in the range of 1 to 10.

9. The two-component urethane composition according to claim 8, wherein the carboxylic acid-derived unit X is one or more units selected from the following: phthalic acid unit, isophthalic acid unit, terephthalic acid unit, trimellitic acid unit, tetrahydrophthalic acid unit, hexahydrophthalic acid unit, tetrachlorophthalic acid unit, and fatty acid unit.

10. The two-component urethane composition according to claim 8, wherein the polyol-derived unit Y is any one or two or more units selected from the following: ethylene glycol unit, propylene glycol unit, 1,2-butanediol unit, 2,3-butanediol unit, 1,3-propanediol unit, 1,3-butanediol unit, 1,4-butanediol unit, 1,6-hexanediol unit, neopentyl glycol unit, 1,2-ethylhexanediol unit, 1,5-pentanediol unit, 1,9-nonanediol unit, 1,10-decanediol unit, 1,3-cyclohexanedimethanol unit, 1,4-cyclohexanedimethanol unit, glycerol unit, and trimethylolpropane unit.

11. The two-component urethane composition according to claim 8, wherein the carboxylic acid-derived unit X is one or more units selected from the following: oxalic acid unit, adipic acid unit, azelaic acid unit, sebacic acid unit, succinic acid unit, malic acid unit, glutaric acid unit, malonic acid unit, pimelic acid unit, suberic acid unit, 2,2-dimethylsuccinic acid unit, 3,3-dimethylglutaric acid unit, 2,2-dimethylglutaric acid unit, maleic acid unit, fumaric acid unit, and itaconic acid unit.

12. A battery module, comprising: a module housing having a top plate, a bottom plate, and side walls, wherein an internal space is formed by the top plate, the bottom plate, and the side walls; a plurality of battery cells present in the internal space of the module housing; and a resin layer formed by curing the composition according to claim 1 and in contact with the plurality of battery cells.

13. A battery pack comprising one or more battery modules according to claim 12.

14. A vehicle comprising the battery module according to claim 12 or the battery pack according to claim 13.

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