KR20210071564A - Two-component resin compositions and method for producing battery module comprising same - Google Patents

Abstract

The present application relates to a resin composition having an improved period in which a solidification phenomenon occurs, easing removal of solids and having excellent thermal conductivity after curing. The present application also relates to a method for manufacturing a battery module including a cured product of the two-component resin composition.

Description

Two-component resin compositions and method for producing battery module comprising same}

The present application relates to a two-component resin composition and a method for manufacturing a battery module including the same.

The secondary battery includes a nickel cadmium battery, a nickel hydride battery, a nickel zinc battery, or a lithium secondary battery. A typical example is a lithium secondary battery, and a lithium secondary battery mainly uses lithium oxide and a carbon material as a positive electrode active material and a negative electrode active material, respectively.

A secondary battery includes an electrode assembly in which a positive electrode plate and a negative electrode plate respectively coated with a positive electrode active material and a negative electrode active material are disposed with a separator interposed therebetween, and a packaging material for sealing and housing the electrode assembly together with an electrolyte. The secondary battery may be classified into a can type and a pouch type according to the shape of the exterior material.

Recently, secondary batteries have been widely used not only in small devices such as portable electronic devices, but also in medium and large devices such as automobiles and power storage devices.

When a secondary battery is used in such a medium-large device, a large number of secondary batteries are electrically connected to increase capacity and output. The pouch-type secondary battery is widely used in these medium-to-large devices due to advantages such as small weight, low manufacturing cost, and easy shape deformation.

A structure accommodated in a case after electrically connecting a plurality of secondary batteries is called a battery module, and a resin composition is used to stably fix the secondary batteries to the battery module. Patent Document 1 discloses a curable resin composition applied to a battery module.

In order to prevent deterioration of the performance of the battery module due to heat generated by a plurality of secondary batteries, the resin composition used a high content of filler to secure excellent heat dissipation performance. In addition, in order for the process in which the resin composition is applied to the battery module to have productivity, the injection processability must be excellent, and the injection process was performed under high pressure for high productivity. However, the liquid component of the resin composition and the inorganic filler were separated from the seam (leakage) present in the injection equipment by such high pressure, and a solidification phenomenon occurred. When the solidification phenomenon as described above occurred, the solids according to the solidification phenomenon had to be removed from the injection equipment. In this case, if the hardness of the solid material is high, it is not easy to remove the solid material, and the frequent solidification phenomenon shortens the life of the injection equipment and also reduces the productivity of the battery module.

Accordingly, there is a need for a two-component resin composition having an improved period in which the solidification phenomenon occurs, easy removal of solids, and excellent thermal conductivity after curing.

Korean Patent Publication No. 2016-0105354

An object of the present application is to provide a two-component resin composition having an improved period in which the solidification phenomenon occurs, easy removal of solids, and excellent thermal conductivity after curing. Another object of the present application is to provide a method of manufacturing a battery module having excellent heat dissipation performance including a cured product of a two-part resin composition.

Among the physical properties mentioned in this specification, when the measured temperature affects the result, unless otherwise specified, the corresponding physical property is a physical property measured at room temperature. The term room temperature is the natural temperature, either warmed or not desensitized, usually at a temperature in the range of about 10°C to 30°C, or on the order of about 23°C or about 25°C. In addition, unless otherwise specified in the specification, the unit of temperature is °C.

Among the physical properties mentioned in this specification, when the measured pressure affects the result, unless otherwise specified, the corresponding physical property is a physical property measured at normal pressure. The term atmospheric pressure refers to a natural pressure that is not pressurized or depressurized, and usually about 1 atmosphere is referred to as atmospheric pressure.

In an example related to the present application, the present application relates to a two-component resin composition used in a battery module. Specifically, as described below, the two-component resin composition of the present application is poured into the case of the battery module and is in contact with one or more battery cells present in the battery module to fix the battery cells in the battery module. can be The two-part resin composition of the present application may be, for example, an adhesive composition.

The two-component resin composition may include a main part including a main resin and a filler; and a curing agent part including a curing agent and a filler, wherein a maximum packing fraction of the filler included in the main part and the curing agent part is 0.80 or more, respectively.

As another example, the maximum packing fraction of the filler included in the main part and the curing agent part may be about 0.81 or more or about 0.82 or more, and may be about 0.85 or less or 0.84 or less.

A method of obtaining the maximum packing fraction of the filler included in the main part and the curing agent part is not particularly limited and may be obtained by a known method. As an example, the maximum packing fraction of the filler included in the main part and the curing agent part can be obtained by DEM simulation. In the simulation, the particle size distribution of the filler particles may be taken as a mean value without consideration. In addition, all of the filler particles can be obtained by assuming that they are spherical. In a state in which gravity is not applied, after randomly injecting in the order of the largest average particle diameter, the particles are packed by applying gravity, and the specific mass deviation (packing fraction) of the packed particles can be obtained.

On the other hand, by using Equation 1 below regarding the packing fraction of binary mixtures, it is expanded to Equation 2 below regarding Multi-component Mixtures of mixed fillers having an average particle size of three or more types. The packing fraction can be obtained.

[Formula 1]

V = V ₁ X ₁ + V ₂ X ₂ + β ₁₂ X ₁ X ₂ + γ ₁₂ X ₁ X ₂ (X ₁ - X ₂ )

[Formula 2]

In Equations 1 and 2, V is the specific volume of the packed particles, {specific volume = 1/packing fraction}, and X is the volume ratio of each particle ( ∑X = 1), and V ₁ , V ₂ and V ₃ are the specific volumes of a single particle. On the other hand, the maximum specific mass deviation can be obtained using the Krieger-Dougherty Model equation, which can simulate the viscosity according to the specific mass deviation of the filler. The maximum packing fraction of the filler included in the main part or the curing agent part is the type of the main resin included in the main part, the content of the main resin, the type of curing agent included in the curing agent part, the content of the curing agent, and the type of the filler. , may vary depending on the size of the filler or the content of the filler.

When the maximum packing fraction of the filler included in the main part and/or the curing agent is 0.80 or more, the main part including the main resin or the curing agent including the curing agent, which will be described later, is a generation cycle of solidification occurring in the injection equipment. It can prolong the life of the injection equipment. In addition, the solids generated in the main part or the curing agent part have low hardness and thus are easy to remove from the injection equipment, so that the efficiency of the solids removal operation can be improved. In addition, it is advantageous for forming a resin layer having a thermal conductivity of 3 W/mK or more.

As an example, fillers included in the main part and the curing agent part may have at least three different average particle diameters (D50).

In the present application, the average particle size is the particle diameter (direct median) at 50% cumulative by volume of the particle size distribution, and the point at which the cumulative value becomes 50% on the cumulative curve with the total volume as 100% after obtaining the particle size distribution based on the volume. is the particle diameter of The average particle diameter (or D50) as described above may be measured by a laser diffraction method.

For example, the fillers included in the main part and the curing agent part include at least a first inorganic filler having an average particle diameter of 40 μm to 120 μm, a second inorganic filler having an average particle diameter of 10 μm to 30 μm, and a agent having an average particle diameter of 5 μm or less. 3 Inorganic fillers may be used.

As another example, the first inorganic filler may have an average particle diameter of about 42 μm or more, 44 μm or more, 46 μm or more, 48 μm or more, 50 μm or more, 52 μm or more, or about 54 μm or more, and about 120 μm or less, 115 μm or more. It may be 110 μm or less, 105 μm or less, 100 μm or less, 95 μm or less, 90 μm or less, 85 μm or less, 80 μm or less, or about 75 μm or less. In addition, as another example, the second inorganic filler may have an average particle diameter of about 12 μm or more, 14 μm or more, 16 μm or more, or about 18 μm or more, and about 28 μm or less, 26 μm or less, or about 24 μm or less. In another example, the third inorganic filler may have an average particle diameter of about 0.01 μm or more, 0.1 μm or more, or about 0.5 μm or more, and may be about 5 μm or less or about 4 μm or less.

In order to form a resin layer with excellent thermal conductivity, an excessive amount of filler must be applied to the resin composition. When the filler is applied in excess, the viscosity of the resin composition increases significantly, the injection equipment becomes overloaded, and the resin by the residual pressure of the injection equipment In the part where the component is discharged and the resin composition of the injection equipment is discharged, the filler aggregates to form a hard solid, which can shorten the life of the injection equipment.

When the first to third inorganic fillers having an average particle diameter in the above range are mixed and used in an appropriate ratio, it may be advantageous for the above-described maximum specific mass deviation to satisfy 0.80. Therefore, it is possible to improve the overload of the injection equipment for injecting the two-component resin composition, and it is possible to more effectively prevent the generation of hard solids even if the filler aggregates due to the resin component escaping due to the residual pressure of the injection equipment. It is easy to remove solids and can also improve the life of the injection equipment.

As an example, the filler included in the main part and the curing agent part may have a sphericity of 0.95 or more. The sphericity can be confirmed through particle shape analysis. In one embodiment, the sphericity of the filler may be defined as a ratio (S'/S) of a surface area (S) of a particle to a surface area (S') of a sphere having the same volume as the particle. For real particles, we usually use circularity. The circularity is obtained by obtaining a two-dimensional image of an actual particle and expressed as a ratio of the boundary P of the image and the boundary of a circle having the same area (A) as the image, and is obtained by the following equation.

<Circularity formula>

Circularity = 4πA/P ²

The circularity has a value ranging from 0 to 1, a perfect circle has a value of 1, and irregularly shaped particles have a value lower than 1.

By using a filler having a sphericity of 0.95 or more, the maximum specific mass variation of the filler contained in the two-component resin composition can be more efficiently increased. Therefore, it may be more advantageous to form a resin layer having a thermal conductivity of 3 W/mK or more.

As an example, at least one or more of the first to third inorganic fillers may be thermally conductive fillers, and preferably, all of them may be thermally conductive fillers. In the present application, the term thermally conductive filler may refer to a material having a thermal conductivity of about 1 W/mK or more, 5 W/mK or more, 10 W/mK or more, or about 15 W/mK or more. Specifically, the thermal conductivity of the thermally conductive filler may be about 400 W/mK or less, 350 W/mK or less, or about 300 W/mK or less. The kind of thermally conductive filler that can be used is not particularly limited, and for example, aluminum oxide (alumina: Al ₂ O ₃ ), aluminum nitride (AlN), boron nitride (BN), silicon nitride (Si ₃ N ₄ ), carbide Ceramic particles such as silicon (SiC) beryllium oxide (BeO), zinc oxide (ZnO), magnesium oxide (MgO), or boehmite may be used.

In addition to the above, various types of fillers may be used as the first to third inorganic fillers. For example, in order to secure the insulating properties of the resin layer in which the resin composition is cured, the use of a carbon filler such as graphite may be considered. Alternatively, fillers such as fumed silica, clay, aluminum hydroxide (Al(OH) ₃ ), magnesium hydroxide (Mg(OH) ₂ ) or calcium carbonate (CaCO ₃ ) may be used.

In order to obtain excellent heat dissipation performance, it may be considered that a high content of the thermally conductive filler is used. The filler used in the high content may be used within the range of 70 wt% to 95 wt% based on 100 wt% of the two-component resin composition. Specifically, the content of the filler may be 100% by weight, about 74% by weight or more, 78% by weight or more, 82% by weight or more, or about 86% by weight or more of the two-part resin composition, 94% by weight or less, 93% by weight or more. % or less or about 92% by weight or less.

When the content of the filler is more than about 95% by weight compared to 100% by weight of the two-part resin composition, an overload occurs in the injection equipment for injecting the two-part resin composition including the filler into the battery module, thereby shortening the life of the injection equipment. On the other hand, if the content of the filler is less than about 70% by weight relative to 100% by weight of the two-part resin composition, it is disadvantageous in that the thermal conductivity of the resin layer formed by curing the two-part resin composition satisfies 3.0 W/mK or more. Therefore, the filler is included in the two-component resin composition in a ratio within the above range, which is advantageous to satisfy the above-mentioned maximum specific mass deviation range, and can improve the overload of injection equipment while forming a resin layer with a thermal conductivity of 3.0 W/mK or more. It is advantageous.

In one example, the filler of the present application may have a moisture content of about 1,000 ppm or less. The moisture content can be measured with a karl fishcer titrator (KR831) under the conditions of 10% relative humidity and 5.0 or less drift. In this case, the moisture content may be an average moisture content with respect to all fillers used in the resin composition. In the present application, a filler satisfying the above conditions may be selectively used, or after the filler to be used is dried in an oven at a temperature of about 200° C., the moisture content of the filler may be adjusted to satisfy the moisture content range. In another example, the upper limit of the moisture content of the filler may be about 800 ppm or less, 600 ppm or less, or about 400 ppm or less, and the lower limit thereof may be about 100 ppm or more or about 200 ppm or more.

As described above, when the thermally conductive filler is used in a high content, the viscosity of the main part, the curing agent part, or the two-part resin composition including them may increase. As described, when the viscosity of the two-part resin composition is too high, the injection processability is poor. In consideration of this, it is preferable to use a liquid or low-viscosity component capable of having sufficient flow as the resin component.

As an example, the main resin included in the main part may be a polyol resin, and the curing agent included in the curing agent part may be a compound having a polyisocyanate group.

The polyol resin as the main resin and the compound having a polyisocyanate group as the curing agent may be cured by reaction at room temperature. The curing reaction may be assisted by a catalyst. For example, the curing reaction of the polyol resin and the compound having a polyisocyanate group may be accelerated with the aid of a catalyst. Accordingly, the two-part resin composition may include both the main resin and the curing agent in a separated state, a mixed state, or a reacted state. The catalyst may be, for example, a tin-based catalyst. As an example of the tin-based catalyst, dibutyltin dilaurate (DBTDL: dibutyltin dilaurate) may be used.

In one example, an ester polyol resin may be used as the polyol resin. When using the ester polyol, it is advantageous to satisfy the range of the maximum specific mass deviation described above, and also to satisfy physical properties such as adhesion to be described later.

Meanwhile, the ester polyol may be amorphous or a polyol having sufficiently low crystallinity. In the present specification, "amorphous" means a case in which the crystallization temperature (Tc) and the melting temperature (Tm) are not observed in a differential scanning calorimetry (DSC) analysis to be described later. At this time, the DSC analysis can be performed within the range of -80 to 60 °C at a rate of 10 °C / min, for example, after raising the temperature from 25 °C to 60 °C at the above rate, the temperature is reduced to -80 °C again, It can be made in a way that the temperature is raised to 60 ℃ again. In addition, in the above, "sufficiently low crystallinity" means that the melting point (Tm) observed in the DSC analysis is less than 15°C, about 10°C or less, 5°C or less, 0°C or less, -5°C or less, -10 It means a case of about ℃ or less or about -20 ℃ or less. In this case, the lower limit of the melting point is not particularly limited, but for example, the melting point may be about -80°C or more, -75°C or more, or about -70°C or more. If the polyol is crystalline or does not satisfy the melting point range, when the crystallinity (at room temperature) is strong, the viscosity difference according to the temperature is easy to increase, so it satisfies the above-mentioned maximum specific mass deviation range or physical properties such as adhesive force described later may be difficult to satisfy.

In one example, as the ester polyol, for example, a carboxylic acid polyol or a caprolactone polyol may be used.

The carboxylic acid polyol may be formed by reacting a component including a carboxylic acid and a polyol (eg, a diol or a triol), and the caprolactone polyol includes caprolactone and a polyol (eg, a diol or a triol). It can be formed by reacting the components. In this case, the carboxylic acid may be a dicarboxylic acid.

In one example, the polyol may be a polyol represented by the following Chemical Formula 1 or 2.

[Formula 1]

[Formula 2]

In Formulas 1 and 2, X is a unit derived from a carboxylic acid, and Y is a unit derived from a polyol. The polyol-derived unit may be, for example, a triol unit or a diol unit. In addition, n and m may be any number, for example, n is a number within the range of 2 to 10, m is a number within the range of 1 to 10, and R ₁ and R ₂ are each independently 1 to 14 carbon atoms. alkylene within the range of

As used herein, the term “carboxylic acid-derived unit” may mean a portion excluding a carboxyl group in a carboxylic acid compound. Similarly, as used herein, the term “polyol-derived unit” may mean a portion of a polyol compound structure excluding a hydroxyl group.

That is, when the hydroxy group of the polyol and the carboxyl group of the carboxylic acid react, water (H ₂ O) molecules are desorbed by the condensation reaction to form an ester bond. As such, when the carboxylic acid forms an ester bond by the condensation reaction, the carboxylic acid-derived unit may mean a portion of the carboxylic acid structure that does not participate in the condensation reaction. In addition, the polyol-derived unit may refer to a portion of the polyol structure that does not participate in the condensation reaction.

In addition, Y in Formula 2 also represents a portion excluding the ester bond after the polyol forms an ester bond with caprolactone. That is, when the polyol-derived unit, Y, in Formula 2 forms an ester bond between the polyol and caprolactone, it may mean a portion of the polyol structure that does not participate in the ester bond. The ester bond is shown in Formulas 1 and 2, respectively.

On the other hand, when the polyol-derived unit of Y in the formula is a unit derived from a polyol including three or more hydroxyl groups, such as a triol unit, a branched structure may be implemented in the Y portion in the formula structure.

In Formula 1, the type of the carboxylic acid-derived unit of X is not particularly limited, but in order to secure desired physical properties, a fatty acid compound, an aromatic compound having two or more carboxyl groups, an alicyclic compound having two or more carboxyl groups, and 2 It may be a unit derived from at least one compound selected from the group consisting of aliphatic compounds having at least two carboxyl groups.

The aromatic compound having two or more carboxyl groups may be, for example, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid or tetrachlorophthalic acid.

The alicyclic compound having two or more carboxyl groups may be, for example, tetrahydrophthalic acid or hexahydrophthalic acid.

In addition, the aliphatic compound having two or more carboxyl groups is, for example, oxalic acid, adipic acid, azelaic acid, sebacic acid, succinic acid, malic acid, glutaric acid, malonic acid, pimelic acid, suberic acid, 2,2-dimethyl succinic acid, 3,3-dimethylglutaric acid, 2,2-dimethylglutaric acid, maleic acid, fumaric acid or itaconic acid.

Considering the low glass transition temperature in the range to be described later, an aliphatic carboxylic acid-derived unit may be preferable rather than an aromatic carboxylic acid-derived unit.

Meanwhile, in Formulas 1 and 2, the type of the polyol-derived unit of Y is not particularly limited, but in order to secure desired physical properties, from the group consisting of an alicyclic compound having two or more hydroxyl groups and an aliphatic compound having two or more hydroxyl groups. may be derived from one or more selected compounds.

The alicyclic compound having two or more hydroxyl groups may be, for example, 1,3-cyclohexanedimethanol or 1,4-cyclohexanedimethanol.

In addition, the aliphatic compound having two or more hydroxyl groups is, for example, ethylene glycol, propylene glycol, 1,2-butylene glycol, 2,3-butylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, 1,2-ethylhexyldiol, 1,5-pentanediol, 1,9-nonanediol, 1,10-decanediol, glycerin or trimethylol It may be propane.

Meanwhile, in Chemical Formula 1, n is an arbitrary number, and the range may be selected in consideration of desired physical properties of the two-component resin composition or a resin layer that is a cured product thereof. For example, n can be about 2 to 10 or 2 to 5.

In addition, in Formula 2, m is an arbitrary number, and the range may be selected in consideration of the desired physical properties of the two-component resin composition or a resin layer that is a cured product thereof. For example, m is about 1 to 10 or 1 to It can be 5.

When n and m in Chemical Formulas 1 and 2 are out of the above ranges, the crystallinity of the polyol may be strengthened and adversely affect the injection processability of the composition.

In Formula 2, R ₁ and R ₂ are each independently alkylene having 1 to 14 carbon atoms. The number of carbon atoms may be selected in consideration of the desired physical properties of the two-component resin composition or a resin layer that is a cured product thereof.

The molecular weight of the polyol may be adjusted in consideration of viscosity, durability, or adhesion, for example, in the range of about 300 to about 2,000. Unless otherwise specified, in the present specification, "molecular weight" may be a weight average molecular weight (Mw) measured using Gel Permeation Chromatograph (GPC). If out of the above range, the reliability of the resin layer after curing may be poor or problems related to volatile components may occur.

In the present application, the type of the compound having a polyisocyanate group included in the curing agent part is not particularly limited, but a non-aromatic compound not containing an aromatic group may be used to secure desired physical properties. When an aromatic polyisocyanate is used, the reaction rate is too fast and the glass transition temperature of the cured product may be high, so it may be disadvantageous to satisfy the above-described maximum specific mass deviation range, and it may be difficult to satisfy physical properties such as adhesion to be described later. can

Examples of the non-aromatic isocyanate compound include aliphatic polyisocyanates such as hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate, norbornane diisocyanate methyl, ethylene diisocyanate, propylene diisocyanate or tetramethylene diisocyanate. ; alicyclic polyisocyanates such as transcyclohexane-1,4-diisocyanate, isophorone diisocyanate, bis(isocyanatemethyl)cyclohexane diisocyanate or dicyclohexylmethane diisocyanate; Or any one or more of the above-mentioned carbodiimide-modified polyisocyanate or isocyanurate-modified polyisocyanate; etc. may be used. Also, mixtures of two or more of the compounds listed above may be used.

Meanwhile, the resin component included in the two-part resin composition may have a glass transition temperature (Tg) of less than 0° C. after curing. When the glass transition temperature range is satisfied, brittle characteristics can be secured in a relatively short time even at a low temperature at which the battery module can be used, and accordingly, impact resistance or vibration resistance can be guaranteed. On the other hand, if the above range is not satisfied, there is a possibility that the tacky of the cured product may be too high or thermal stability may be deteriorated. In one example, the lower limit of the glass transition temperature of the two-component resin composition after curing may be about -70°C or more, -60°C or more, -50°C or more, -40°C or more, or about -30°C or more, The upper limit may be about −5° C. or less, −10° C. or less, −15° C. or less, or about −20° C. or less.

In the present application, the expression “after curing” may be used in the same sense as “hardening”. The deep curing may mean a state in which it can be seen that the two-component resin composition injected into the module to manufacture the battery module is sufficiently hardened to perform a function such as actual heat dissipation. Taking a urethane resin as an example, the anti-curing is based on 24 hours of curing at room temperature and 30% to 70% relative humidity conditions, the conversion rate of NCO peak in the vicinity of ^{2250 cm -1 confirmed by FT-IR analysis (} conversion) can be confirmed from 80% or more.

On the other hand, the ratio of the polyol resin component and the polyisocyanate component in the two-component resin composition is not particularly limited, and may be appropriately adjusted so that a urethane reaction between them is possible.

As an example, the viscosity value of the two-part resin composition of the present application may be about 500,000 cP or less. The lower limit may be, for example, about 150,000 cP or greater. For example, the viscosity value of the two-part resin composition may be about 450,000 cP or less, 400,000 cP or less, or about 350,000 cP or less, and may be about 160,000 cP or more, 180,000 cP or more, or about 200,000 cP or more.

Meanwhile, the viscosity of the two-component resin composition may be measured at room temperature using a Brookfield HB type viscometer. Specifically, the viscosity can be measured using a Brookfield HB type viscometer at about 25 °C with a torque of about 90% and a shear rate of about 100 rpm.

As an example, the load value measured within 30 seconds of the main part and the curing agent part starting the curing reaction may be 35 kgf or less.

As another example, the load value may be about 10 kgf or more, 11 kgf or more, 12 kgf or more, 13 kgf or more, 14 kgf or more, or about 15 kgf or more, and about 34 kgf or less, 32 kgf or less, 30 kgf or less, or about 28 kgf can be below. If the load value is too low, overflow may occur after the two-part resin composition is injected into the battery module or the storage stability of the two-part resin composition may be deteriorated.

Meanwhile, the load value of the two-component resin composition may be measured using the mixer 1 configured as shown in FIG. 1 . Specifically, the load value is determined by injecting the main part and the curing agent into the two cartridges 2a and 2b, respectively, pressurizing the main part and the curing agent at a constant speed of 1 mm/s with the pressing means 3a and 3b, and the mixer 5 for the main part and the curing agent. The curing agent part is injected, and the force applied to the pressing means is measured from the time when the main resin of the main part and the curing agent of the curing agent part are first discharged 90 seconds after the start of the curing reaction in the mixer, and the force is the maximum value At this point, the maximum value may be used as the load value. On the other hand, when 90 seconds have elapsed from the start of the curing reaction of the main resin and the curing agent, the pressure is stopped when the main part and the curing agent are injected into the mixer 5 to reach about 95% of the capacity (volume) of the mixer, It means a time point when 90 seconds have elapsed from the stop time. Therefore, when the 90 seconds have elapsed, the force applied to the pressing means is measured from the first discharge by re-pressurizing with the pressing means at a constant speed of 1 mm/s, and the maximum value is obtained at the point where the force becomes the maximum value. It can be set as the said load value.

The maximum value in the load value is the maximum value initially confirmed in the process, and is the maximum value at the first point where the applied force increases and then decreases, or the maximum value at the point where the applied force increases and then does not increase any more. to be.

Meanwhile, in the mixer 1, the cartridge 2 is not particularly limited, and a known cartridge may be used as long as it can accommodate the main part and the curing agent part. In one embodiment, the diameter of the cartridge accommodating the main part or the curing agent part is about 15 mm to about 20 mm circular, and the diameter of the first discharge parts 4a and 4b for discharging the main part or the curing agent part is about 2 mm to about 5 mm circular. and a height of about 80 mm to about 300 mm, and a total capacity of about 10 ml to about 100 ml.

The pressurizing means 3a and 3b in the mixer 1 are not particularly limited, and a known pressurizing means may be used. For example, the pressing means may use a TA (Texture Analyser). The pressing means (3a, 3b) can press the cartridge (2a, 2b) to discharge the main part and the curing agent inside the cartridge through the mixer (5). The pressing speed of the pressing means 3a and 3b may be about 0.01 to about 1 mm/s. For example, the pressing speed may be about 0.01 mm/s or more, 0.05 mm/s or more, or about 0.1 mm/s or more, and about 1 mm/s or less, 0.8 mm/s or less, 0.6 mm/s or less, 0.4 mm/s or less. s or less or about 0.2 mm/s or less.

The mixer 5 in the mixer 1 is not particularly limited, and a known mixer may be used. For example, the mixer may be a static mixer. In one embodiment, the static mixer 5 is mixed by the static mixer 5 and two accommodating parts 6a and 6b for accommodating the main part and the curing agent part respectively from the two cartridges 2a and 2b. It has one second discharge part 7 for discharging the two-component resin composition, and the size of the receiving parts 6a and 6b is a circular shape with a diameter of about 2 mm to about 5 mm, respectively, and the diameter of the second discharge part 7 has a circular shape of about 1 mm to about 3 mm, and the number of elements may be about 5 to about 20.

Meanwhile, the capacity of the mixer may have a capacity satisfying the range of Formula 1 below.

[General formula 1]

V < t2/td * Q

In Formula 1, V is the capacity of the static mixer, t2 is the time for doubling the viscosity of the two-component resin composition, td is the dispensing process time, and Q is the injection amount per process unit time. When the capacity of the static mixer is greater than the time (t2) for which the viscosity is doubled, the residence time exceeds the amount per unit process and the viscosity increases, and if the process speed is slow or severe, the resin composition is cured and the mixer is likely to be blocked.

As an example, the cured product of the two-component resin composition of the present application may form a resin layer having a thermal conductivity of 3.0 W/mK or more. As another example, the resin layer has a thermal conductivity of about 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. or less, 15 W/mk or less, or about 10 W/mK or less. The thermal conductivity of the resin layer is, for example, a value measured according to ASTM D5470 standard or ISO 22007-2 standard. The thermal conductivity of the resin layer as described above is effective in dissipating heat generated inside the battery module to the outside, which will be described later.

As an example, in the thermogravimetric analysis (TGA) of the solids generated by the solidification generating device, the residual amount of the resin at 800° C. may be 7.6% by weight or more in the main part or the curing agent part. As another example, it may be about 7.7 wt% or more, 7.8 wt% or more, 7.9 wt% or more, or about 8.0 wt% or more. The solidification generating device will be described later.

In a two-component resin composition that satisfies a resin residual amount of 7.6% by weight or more at 800° C. in thermogravimetric analysis (TGA) in the solids generated from the main part or the curing agent part, some of the resin component escapes due to the pressure of the injection equipment, and the filler aggregates. Even if a phenomenon occurs, the generation of hard solids is prevented, so it is easy to remove solids, and the life of the injection equipment can be improved.

On the other hand, thermogravimetric analysis (TGA), 60 cm ³ / min nitrogen (N ₂ ) atmosphere at a temperature increase rate of 20 °C / min can be measured in the range of 25 to 800 ℃.

As an example, the main part or the curing agent part may further satisfy the following general formula (2).

[General Formula 2]

Hardness of solid (H) ≤ 200

In the general formula 2, H is applied to the pressing means at an arbitrary point in time when 0.3 seconds to 0.7 seconds have elapsed from when the solid material of the main part or the curing agent part is pressed at a constant velocity of 0.3 mm/s. is the force (gf).

In the general formula 2, any one time point when 0.3 seconds to 0.7 seconds have elapsed may mean, for example, a time point when about 0.3 seconds, 0.4 seconds, 0.5 seconds, 0.6 seconds, or about 0.7 seconds have elapsed from when the solid material was pressed. have.

In Formula 2, the solid material of the main part or the curing agent part may refer to a specimen obtained by cutting the solid material generated through the solidification generator of FIG. 2 .

2 is an exemplary cross-sectional view of a solidification generating device. The solidification generating device 10 may include a syringe 11 and a filter 12 positioned at the discharging part 11a of the syringe. In addition, the solidification generating device 10 may have a pressing means 13 capable of pressing the composition filled in the syringe.

The syringe 11 is not particularly limited, and a known syringe may be used. In one embodiment, the syringe has a circular injection part having a diameter of about 23 mm to about 27 mm, and the ejection part 11a of the syringe has a circular diameter of about 6 mm to about 10 mm, and a syringe height of about 75 mm to Syringes of about 85 mm in diameter and having an internal volume of about 20 ml to about 30 ml may be used.

As the filter 12, a known filter may be used, and in one embodiment, a filter having a pore size of about 0.4 μm to about 0.5 μm and a diameter of about 10 mm to about 15 mm may be used.

The syringe 11 and the filter 12 may be coupled by a conventional coupling method. For example, the syringe and the filter may be fastened by a male and female screw type. Specifically, a spiral embossed may be formed on the outer circumferential surface of the syringe to which the filter is coupled, and a spiral intaglio may be formed on the inner circumferential surface of the filter coupled to the syringe so that the spiral embossed formed on the outer circumferential surface of the syringe can be fastened. .

On the other hand, the pressing means 13 is not particularly limited, and a known pressing means can be used. In one embodiment, a texture analyzer (TA) may be used as a pressurizing means.

The syringe 11 of the solidification generating device of FIG. 2 may be filled with the main part or the curing agent part and pressurized by the pressing means 13 to generate a solid. In one embodiment, the main part or the curing agent part is filled in the syringe 11 of the solidification generating device 10 of FIG. 2, and the pressing means 13 is about 4 bar to about 8 bar, about 4 bar to about 7 bar or A pressure of about 5 bar to about 6 bar may be pressurized for about 14 hours to about 18 hours or about 15 hours to about 17 hours to generate a solid.

According to the above method, the solid material generated on the filter 12 combined with the discharge part 11a is made into a cylinder having a diameter of about 1 mm to about 2 mm and a height of about 1 mm to about 4 mm. Thus, the hardness of the solid can be measured.

Therefore, the hardness (H) of the solid material starts to measure the force applied to the pressing means from the time of pressing the specimen of the solid material when the specimen of the solid material is pressed at a constant speed of 0.3 mm/s, and from the time of pressing The force (gf) applied to the pressing means at any one time point after 0.3 seconds to 0.7 seconds has elapsed may be the hardness of the solid. The above-described TA (Texture Analyzer) may be used as the pressing means.

The solid hardness (H) of Formula 2 may be, for example, about 180 gf or less, 160 gf or less, 140 gf or less, or about 120 gf or less, and about 10 gf or more, 15 gf or more, 20 gf or more, or about 25 gf or more. can

In order to inject the two-component resin composition into the battery module, it is necessary to apply a certain force to the injection equipment to inject the two-component resin composition charged in the injection equipment into the battery module. At this time, the resin component and the filler component of the two-component resin composition are separated by pressurization, so that a solidification phenomenon may occur in a leakage portion of the injection equipment, thereby forming a solid. If solids form in the dosing equipment, they must be removed from the dosing equipment. At this time, it is not easy to remove the solid material formed in the battery module as the hardness of the solid material is higher. In addition, if the solids generation cycle is short, the life of the injection equipment may be shortened, and the productivity of the battery module may be greatly reduced.

The two-component resin composition in which the hardness of the solid material according to Formula 2 satisfies 200 gf or less, the cycle of generating solids in the injection equipment is long, and thus the life of the injection equipment can be extended, and the battery module productivity is improved. can In addition, the hardness of the generated solid is low, so it is easy to remove the solid from the battery module.

The two-component resin composition may contain a viscosity modifier, for example, a thixotropic agent, a diluent, a dispersant, a surface treatment agent, or a coupler to control the required viscosity, for example, to increase or decrease the viscosity or to control the viscosity according to shear force. It may further include a ring agent and the like.

The thixotropic agent may adjust the viscosity according to the shear force of the two-component resin composition so that the manufacturing process of the battery module can be effectively performed. As the thixotropic agent that can be used, fumed silica and the like may be exemplified.

Diluents or dispersants are generally used to lower the viscosity of the two-part resin composition, and as long as they can exhibit the above action, various types of known in the art may be used without limitation.

The surface treatment agent is for surface treatment of the filler introduced into the resin layer, and various types known in the art may be used without limitation as long as it can exhibit the above-described action.

In the case of the coupling agent, for example, it may be used to improve the dispersibility of the thermally conductive filler such as alumina, and if it can exhibit the above action, various types of known in the art may be used without limitation.

In addition, the two-component resin composition may further include a flame retardant or a flame retardant auxiliary agent. In this case, a known flame retardant may be used without any particular limitation, for example, a flame retardant in the form of a solid filler or a liquid flame retardant may be applied. Examples of the flame retardant include organic flame retardants such as melamine cyanurate and inorganic flame retardants such as magnesium hydroxide. When the amount of 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.) may be used. In addition, a silane coupling agent capable of acting as a flame retardant synergist may be added.

The two-part resin composition may include the configuration as described above, and may be a solvent-based composition, an aqueous composition, or a solvent-free composition, but considering the convenience of the manufacturing process, the solvent-free type may be appropriate.

The two-part resin composition of the present application may have physical properties suitable for the uses described below.

In one example, in the two-component resin composition, the leakage current measured after 60 minutes at room temperature after the main part and the curing agent part starts the curing reaction may be less than about 1 mA. The lower limit of the leakage current is not particularly limited, but considering the composition of the two-component resin composition, it may be about 0.01 mA or more, 0.02 mA or more, 0.03 mA or more, or about 0.05 mA or more. The leakage current was measured according to ISO 6469-3. When the range of the leakage current is satisfied, the resin layer formed after curing of the two-component resin composition has excellent electrical insulation properties. Therefore, the performance of the battery module can be maintained and stability can be secured. The leakage current as described above can also be controlled by adjusting the components of the resin composition. For example, the leakage current can be controlled by applying an insulating filler in the two-component resin composition. In general, the ceramic filler as described above among thermally conductive fillers is known as a component capable of securing insulation.

In one example, in the two-part resin composition, the adhesive strength (S1) of the two-part resin composition measured after 24 hours at room temperature after the main part and the curing agent part starts the curing reaction may be about 200 gf/10mm or more. That is, it may mean the adhesive force after curing of the two-component resin composition. In another example, the adhesion is at least about 220 gf/10mm, at least 250 gf/10mm, at least 300 gf/10mm, at least 350 gf/10mm, at least 400 gf/10mm, at least 420 gf/10mm, at least 440 gf/10mm, or at least about 460 gf /10mm or more. When the adhesive force satisfies the above range, the battery module may secure appropriate impact resistance and vibration resistance. The upper limit of the adhesive strength is not particularly limited, and for example, about 1,000 gf/10mm or less, 900 gf/10mm or less, 800 gf/10mm or less, or 700 gf/10mm or less, 600 gf/10mm or less, or about 500 gf/10mm or less. It may be about the following. If the adhesive force is too high, there is a risk of tearing the resin layer formed after curing of the two-part resin composition and the pouch portion to which it is attached. Specifically, if an impact occurs to the extent that the shape of the battery module is deformed due to an accident while driving, if the battery cell is attached too strongly through the resin layer, the pouch is torn and hazardous materials inside the battery may be exposed or explode. have. The adhesion can be measured for an aluminum pouch. For example, an aluminum pouch used for manufacturing a battery cell is cut to a width of about 10 mm, a two-component resin composition is loaded on a glass plate, and the cut aluminum pouch is placed on the PET (poly(ethylene) After loading so that the terephthalate) side and the two-part resin composition are in contact, the two-part resin composition is cured at 25° C. and 50% RH for 24 hours, and the aluminum pouch is peeled at 180° with a tensile tester (texture analyzer). Adhesion can be measured while peeling at an angle and a peel rate of 300 mm/min.

In another example, the adhesive strength after curing of the two-component resin composition may be maintained at a significant level even under high temperature/high humidity. Specifically, in the present application, with respect to the adhesive force (S1) after curing measured at room temperature, the % ratio [ (S2/S1) x 100] may be about 70% or more or about 80% or more. In one example, the high-temperature/high-humidity accelerated test may be measured after storing the same specimen as the specimen used to measure the room temperature adhesion at a temperature of 40°C to 100°C and a humidity condition of 75% RH or more for 10 days. . When the above adhesive force and relationship are satisfied, excellent adhesion durability may be maintained even if the usage environment of the battery module is changed.

In one example, the two-component resin composition may have excellent heat resistance after curing. In this regard, the composition of the present application has a temperature of 5% weight loss (5% weight loss) of 120°C during thermogravimetric analysis (TGA) measured for a cured product of only the resin component in a state that does not include a filler. may be more than In addition, the two-component resin composition of the present application may have a residual amount of about 70% by weight or more at 800° C. during thermogravimetric analysis (TGA) measured on the cured product of the two-part resin composition in a state including a filler. The remaining amount at 800°C may be about 75% by weight or more, 80% by weight or more, 85% by weight or more, or about 90% by weight or more in another example. The remaining amount at 800°C may be about 99% by weight or less in another example. At this time, thermogravimetric analysis (TGA), 60 cm ³ / min nitrogen (N ₂ ) atmosphere in the 20 ℃ / min at a temperature increase rate can be measured in the range of 25 to 800 ℃. The heat resistance properties related to the thermogravimetric analysis (TGA) may be secured by controlling the type or content of the resin and/or filler.

In another example related to the present application, the present application relates to a method of manufacturing a battery module.

A battery module manufactured according to the manufacturing method in the present application will be described first, and then a manufacturing method of the battery module according to the present application will be described.

A battery module manufactured according to the manufacturing method of the present application includes a module case and a battery cell. The battery cell may be accommodated in the module case. One or more battery cells may be present in the module case, and a plurality of battery cells may be accommodated in the module case. The number of battery cells accommodated in the module case is not particularly limited as it is adjusted according to the use or the like. The battery cells accommodated in the module case may be electrically connected to each other.

The module case may include at least a side wall and a lower plate forming an internal space in which the battery cell can be accommodated. In addition, the module case may further include an upper plate sealing the inner space. The side wall, the lower plate, and the upper plate may be integrally formed with each other, or the module case may be formed by assembling the separate side walls, the lower plate, and/or the upper plate, respectively. The shape and size of the module case are not particularly limited, and may be appropriately selected depending on the purpose or the shape and number of battery cells accommodated in the internal space.

In the above, the terms upper plate and lower plate are terms of a relative concept used to distinguish between at least two plates constituting the module case. That is, it does not mean that the upper plate necessarily exists in the upper part and the lower plate necessarily exists in the lower part in an actual use state.

A hole may be formed in the lower plate, the side wall, and/or the upper plate of the module case. The hole may be an injection hole used to inject a material for forming the resin layer, that is, the above-described two-component resin composition, when the resin layer is formed by an injection process. The shape, number, and position of the holes may be adjusted in consideration of injection efficiency of the resin layer forming material. In one example, the hole may be formed in at least the lower plate and/or the upper plate.

An observation hole may be formed at the ends of the upper plate and the lower plate in which the injection hole is formed. This observation hole, for example, may be formed to observe whether the injected material is well injected to the end of the side wall, the lower plate, or the upper plate when the resin layer material is injected through the injection hole. The position, shape, size, and number of the observation holes are not particularly limited as long as they are formed so as to confirm whether the injected material is properly injected.

The module case may be a thermally conductive case. The term thermally conductive case refers to a case having an overall thermal conductivity of 10 W/mk or more, or at least including a portion having the above-described thermal conductivity. For example, at least one of the aforementioned sidewall, lower plate, and upper plate may have the aforementioned thermal conductivity. In another example, at least one of the side wall, the lower plate, and the upper plate may include a portion having the thermal conductivity. For example, the battery module of the present application may include a first cured resin layer in contact with the upper plate and the battery cell, and a second cured resin layer in contact with the lower plate and the battery cell, wherein at least the second resin layer is a thermoelectric layer. It may be a conductive resin layer. Accordingly, it can be said that at least the lower plate may have thermal conductivity or include a thermally conductive portion.

a top plate, a bottom plate, and a side wall that are thermally conductive in the above; Or thermal conductivity of the region; in another example, about 20 W / mk or more, 30 W / mk or more, 40 W / mk or more, 50 W / mk or more, 60 W / mk or more, 70 W / mk or more, 80 W/mk or more, 90 W/mk or more, 100 W/mk or more, 110 W/mk or more, 120 W/mk or more, 130 W/mk or more, 140 W/mk or more, 150 W/mk or more, 160 W /mk or more, 170 W/mk or more, 180 W/mk or more, 190 W/mk or more, or about 195 W/mk or more. The higher the thermal conductivity, the more advantageous in terms of heat dissipation characteristics of the module, and the upper limit thereof is not particularly limited. In one example, the thermal conductivity is 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 about 250 W/mK or less, but is not limited thereto. The type of material exhibiting the above thermal conductivity is not particularly limited, and for example, a metal material such as aluminum, gold, silver, tungsten, copper, nickel, or platinum may be used. The module case may be entirely made of the thermally conductive material as described above, or at least a portion of the module case may be made of the thermally conductive material. Accordingly, the module case may have thermal conductivity within the above-mentioned range, or may include at least one portion having the above-mentioned thermal conductivity.

In the module case, a portion having thermal conductivity within the above range may be a portion in contact with the resin layer and/or the insulating layer. In addition, the portion having the thermal conductivity may be a portion in contact with a cooling medium such as cooling water. In the case of having such a structure, heat generated from the battery cell can be effectively discharged to the outside.

In the present application, the term battery cell refers to a single unit secondary battery including an electrode assembly and a casing.

The type of battery cells accommodated in the battery module case is not particularly limited, and all known various battery cells may be applied. In one example, the battery cell may be of a pouch type.

The battery module of the present application may further include a resin layer. Specifically, the battery module of the present application may include a cured resin layer in which the filler-containing composition is cured. The cured resin layer may be formed from the above-described two-component resin composition.

The battery module may include, as the resin layer, a first cured resin layer in contact with the upper plate and the battery cell, and a second cured resin layer in contact with the lower plate and the battery cell. At least one of the first and second cured resin layers may include a cured product of the above-described resin composition, and thus may have the predetermined adhesive strength, cold resistance, heat resistance, and insulation properties described above.

In addition, the first and second cured resin layers are thermally conductive resin layers, and the thermal conductivity of the resin layer is about 3 W/mK or more as described above. Meanwhile, the lower plate, the upper plate, and/or the side wall to which the resin layer is attached may be a region having the aforementioned thermal conductivity of 10 W/mK or more. In this case, the portion of the module case showing the thermal conductivity may be a portion in contact with a cooling medium, for example, cooling water.

In addition, the resin layer may be a flame retardant resin layer. In the present application, the term flame retardant resin layer may mean a resin layer showing a V-0 grade in UL 94 V Test (Vertical Burning Test). This ensures safety against fires and other accidents that may occur in the battery module.

At least one of the sidewall, the lower plate, and the upper plate in contact with the resin layer in the battery module of the present application may be the aforementioned thermally conductive sidewall, lower plate, or upper plate. On the other hand, in this specification, the term contact, for example, the resin layer and the upper plate, lower plate and / or sidewall; Alternatively, it may mean a case in which the battery cells are in direct contact or another element, for example, an insulating layer, is present therebetween. In addition, the resin layer in contact with the thermally conductive sidewall, the lower plate, or the upper plate may be in thermal contact with the object. At this time, in the thermal contact, the resin layer is in direct contact with the lower plate or the like, or there is another element, for example, an insulating layer to be described later, between the resin layer and the lower plate, etc., but the other element is the It may mean a state in which heat transfer from the battery cell to the resin layer and from the resin layer to the lower plate is not prevented. The fact that heat transfer is not hindered in the above means that even when another element (eg, an insulating layer) exists between the resin layer and the lower plate, the total thermal conductivity of the other element and the resin layer is about 1.5 W/ mK or more, 2 W/mK or more, 2.5 W/mK or more, 3 W/mK or more, 3.5 W/mK or more, or about 4 W/mK or more, or the entire resin layer and the lower plate in contact with it It means that the thermal conductivity is included within the range even if the other factors are present. The thermal conductivity of the thermal contact is about 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. Such thermal contact may be achieved by controlling the thermal conductivity and/or thickness of the other element, if present.

The thermally conductive resin layer may be in thermal contact with the lower plate and the like, and may also be in thermal contact with the battery cell. Through the adoption of the above structure, the heat dissipation characteristics are secured, and the unit volume while significantly reducing the various fastening parts or cooling equipment of the module, etc., which were previously required in the configuration of a general battery module or a battery pack, which is an aggregate of such modules. It is possible to implement a module in which more battery cells are accommodated per unit. Accordingly, in the present application, it is possible to provide a more compact, light and high-output battery module.

In one example, the battery module may further include an insulating layer between the module case and the battery cell or between the resin layer and the module case. By adding an insulating layer, it is possible to prevent problems such as electric short circuit or fire caused by contact between the cell and the case due to an impact that may occur during use. The insulating layer may be formed using an insulating sheet having high insulating properties and thermal conductivity, or may be formed by coating or injecting a material exhibiting insulating properties. For example, a process of forming an insulating layer may be performed before injection of the two-part resin composition. A so-called TIM (thermal interface material) or the like may be applied to the formation of the insulating layer. Alternatively, the insulating layer may be formed of an adhesive material. For example, the insulating layer may be formed using a resin layer with little or no filler such as a thermally conductive filler. As a resin component that can be used to form the insulating layer, acrylic resin, olefin resin such as PVC (poly(vinyl chloride)), PE (polyethylene), epoxy resin, silicone, or EPDM rubber ((ethylene propylene diene monomer rubber) The insulating layer may have a breakdown voltage of about 5 kV/mm or more, 10 kV/mm or more, 15 kV/mm measured according to ASTM D149, but is not limited thereto. or more, it may be 20 kV/mm or more, 25 kV/mm or more, or about 30 kV/mm or more.The breakdown voltage is not particularly limited as it shows excellent insulation as the value increases. For example, the insulation The dielectric breakdown voltage of the layer may be about 100 kV/mm or less, 90 kV/mm or less, 80 kV/mm or less, 70 kV/mm or less, or about 60 kV/mm or less. It can be set in an appropriate range in consideration of insulation or thermal conductivity, for example, about 5 μm or more, 10 μm or more, 20 μm or more, 30 μm or more, 40 μm or more, 50 μm or more, 60 μm or more, 70 μm or more. or more, 80 μm or more, or about 90 μm or more The upper limit of the thickness is not particularly limited, for example, about 1 mm or less, 200 μm or less, 190 μm or less, 180 μm or less, 170 μm or less , 160 μm or less or about 150 μm or less.

The manufacturing method of the battery module according to the present application includes the steps of injecting the two-component resin composition in the module case described above; Accommodating a battery cell in the module case and curing the resin composition to form a resin layer, wherein injecting the two-component resin composition measures the maximum specific mass deviation of the two-component resin composition, When the measured maximum specific mass deviation meets the preset maximum specific mass deviation, the two-component resin composition is injected into the module case.

The order of the step of injecting the two-component resin composition into the module case and the step of accommodating the battery cells in the module case is not particularly limited. For example, the two-component resin composition may be first injected into the module case, and then the battery cells may be accommodated in that state, or the two-part resin composition may be injected after the battery cells are first housed in the module case.

The maximum specific mass deviation of the two-component resin composition means the specific mass deviation of the main part and the curing agent part. Therefore, the two-component resin composition can be mixed and injected into the module case only when the maximum specific mass deviation of the main part and the curing agent part is compared with the preset maximum specific mass deviation of the main part and the curing agent part.

On the other hand, the preset maximum specific mass deviation of the main part or the curing agent part may be set in consideration of the solidification occurrence cycle, whether solids are easily removed, or whether excessive loading of the injection equipment occurs. For example, the preset maximum specific mass deviation of the main part and the curing agent part may be about 0.80 to about 0.85.

The two-component resin composition in which the maximum specific mass deviation of the main part and the curing agent part satisfies the above ranges has a long solidification cycle and low solid hardness, so it is easy to remove solids, and it can be easy to secure excellent thermal conductivity after curing. have.

Therefore, in the manufacturing stage of the battery module, it is determined whether the maximum specific mass deviation of the filler meets the preset maximum specific mass deviation, and only when it is met, the two-component resin composition is mixed with the two-component resin composition and injected into the battery. In addition to being able to improve the thermal conductivity of the battery module, it has the effect of preventing in advance from occurring.

According to an example of the present application, there is provided a resin composition having an improved period in which the solidification phenomenon occurs, easy removal of solids, and excellent thermal conductivity after curing. Also provided is a method for manufacturing a battery module including a cured product of the two-part resin composition.

1 shows an exemplary mixer that may be applied in the present application.
2 shows an exemplary solidification generating device that can be applied in the present application.

Hereinafter, the present application will be described in detail through Examples, but the scope of the present application is not limited by the Examples below.

Maximum Packing Fraction

The maximum specific mass deviation (maximum packing fraction) of the filler included in the main part and the curing agent part of Examples and Comparative Examples was obtained by using DEM Simulation. Specifically, the particle size distribution of the mixed filler particles was taken as a mean value without consideration, and all filler particles were assumed to be spherical. In a state in which gravity is not applied, after randomly injecting in the order of the largest average particle diameter, the particles are packed by applying gravity, and the specific mass deviation (packing fraction) of the packed particles is calculated. In addition, the maximum specific mass deviation was obtained using the Krieger-Dougherty Model equation, which can simulate the viscosity according to the specific mass deviation of the filler.

load value

The load value (kgf) of the two-component resin composition was measured using a mixer 1 constructed by combining two cartridges 2a and 2b and a static mixer 5 as shown in FIG. 1 .

As for the cartridges 2a and 2b (Sulzer, AB050-01-10-01) in the mixer configured as shown in FIG. 1, the resin injection part is a circle with a diameter of 18 mm, and the discharge parts 4a and 4b are circular with a diameter of 3 mm. , the cartridges (2a, 2b) are 100mm in height and have an internal volume of 25ml. In addition, as the static mixer 5 (Sulzer, MBH-06-16T), a circular discharge part 7 having a diameter of 2 mm was used. The static mixer is of a stepped type, and the number of elements is 16.

As the pressing means 3, 3a, 3b in the configuration as shown in FIG. 1, TA (Texture Analyser) was applied.

The main part prepared in Examples and Comparative Examples is filled in any one of the two cartridges 2a and 2b, and the curing agent part is filled in the other cartridge, and then a constant force is applied with the pressing means 3, 3a, 3b to first discharge. After mixing in the static mixer 5 via the parts 4a and 4b, the load value was measured while being discharged to the second discharging unit 7 .

That is, the main part and the curing agent part are injected into the two cartridges 2a and 2b, respectively, and the main part is pressed with a TA (texture ananlyer) 3a, 3b at a constant speed of 1 mm/s, and the main part is used with the static mixer 5 and the curing agent part is injected, and the main resin of the main part and the curing agent of the curing agent part in the mixer 5 are measured 90 seconds after the start of the curing reaction, and the force applied to the pressing means is measured from the time it is first discharged, The said maximum value was made into the said load value at the point used as this maximum value. On the other hand, when 90 seconds have elapsed from the start of the curing reaction of the main resin and the curing agent, the pressure is stopped when the main part and the curing agent are injected into the mixer 5 to reach about 95% of the capacity (volume) of the mixer, It means a time point when 90 seconds have elapsed from the stop time. Therefore, when the 90 seconds have elapsed, the force applied to the pressing means is measured from the first discharge by re-pressurizing with the pressing means at a constant speed of 1 mm/s, and the maximum value is obtained at the point where the force becomes the maximum value. It was set as the said load value.

The maximum value in the load value is the maximum value initially confirmed in the process, and is the maximum value at the first point where the applied force increases and then decreases, or the maximum value at the point where the applied force increases and then does not increase any more. to be.

thermal conductivity

Thermal conductivity was measured using the two-component resin composition of Examples and Comparative Examples in accordance with the ISO 22007-2 measurement standard by a hot-disk (Hot-Dist) method. Specifically, the cured product of the two-component resin composition may be placed in a mold having a thickness of about 7 mm, and thermal conductivity may be measured in the through plane direction using a hot disk device. As stipulated in the above standard (ISO 22007-2), the Hot Disk equipment is an equipment that can check the thermal conductivity by measuring the temperature change (electrical resistance change) while the sensor with the nickel wire has a double spiral structure is heated. Thermal conductivity was measured according to the standard.

Hardness of solids (H)

Solids generation: Solids were generated using a solidification generating device 10 constructed by combining a syringe and a filter as shown in FIG. 2 . As for the syringe 11 in the solidification generating device configured as shown in FIG. 2, the injection part has a circular diameter of about 25 mm, the discharge part 11a of the syringe has a circular diameter of about 8 mm, the syringe height is about 80 mm, and the internal volume is About 25 ml was used. In addition, as the filter 12, a PTFE filter (pore size: 0.45 μm, diameter: 13 mm) manufactured by Whatman was used. In the configuration shown in FIG. 2 , a texture analyzer (TA) was used as the pressing means 13 . The resin composition prepared in Examples and Comparative Examples is filled in the syringe 11 of the solidification generator of FIG. 2, and the pressure of about 5 bar is pressed with the pressurizing means 13 for about 16 hours to combine with the filter 12 It was induced to generate solids according to the solidification phenomenon of the resin composition inside the discharge part 11a.

Hardness of solids: According to the above method, a specimen of solids was prepared so that the solids generated on the filter combined with the discharge part had a cylindrical shape with a diameter of about 2mm and a height of about 2mm, and the hardness of the solids was measured using this. . Specifically, the hardness (H) of the solid material starts to measure the force applied to the pressing means from the time the solid material is pressed when the specimen of the produced solid material is pressed at a constant velocity of 0.3 mm/s, and is approximately from the time of pressing. The force (gf) applied to the pressing means at the time of 0.5 second elapsed was taken as the hardness of the solid. As the pressurizing means, the TA (Texture Analyzer) was used.

Equipment maintenance cycle evaluation

When the load value is X(kgf) for the normal operation of the injection equipment after equipment inspection (10 hours daily operation), the amount of time it takes from the equipment inspection until the load value of the injection equipment becomes X+20 (kgf) or more than 50kgf Time was counted to evaluate the equipment maintenance cycle.

[Evaluation standard]

If the equipment maintenance interval is more than 600 hours: ○

If the equipment maintenance interval is less than 600 hours: ×

Example

A two-component urethane-based adhesive composition was used. The main resin of the main part is a caprolactone-based polyol represented by Formula 2, the number of repeating units (m in Formula 2) is at a level of about 1 to 3, and as a polyol-derived unit (Y in Formula 2), ethylene glycol A main composition including a polyol including a propylene glycol unit and a propylene glycol unit was used, and a curing agent for the curing agent part was a composition including a hexamethylene diisocyanate trimer.

_{A plurality of alumina fillers having an average particle diameter (D 50} ) and a ratio as shown in Table 1 below were used as the fillers included in the main part and the curing agent part, and about 84% to about 89% by weight compared to 100% by weight of the two-component resin composition % was divided and blended in equal amounts in the main part and the curing agent part. The maximum specific mass deviation of the fillers included in the main part and the curing agent part was 0.811, respectively.

Comparative Example 1

The main part and the hardening|curing agent part were the same as Example 1 used.

_{A plurality of alumina fillers having an average particle diameter (D 50} ) and a ratio as shown in Table 1 below were used as the fillers included in the main part and the curing agent part, and about 84% to about 89% by weight compared to 100% by weight of the two-component resin composition % was divided and blended in equal amounts in the main part and the curing agent part. The maximum specific mass deviation of the fillers included in the main part and the curing agent part was 0.784, respectively.

Comparative Example 2

The main part and the hardening|curing agent part were the same as Example 1 used.

_{A plurality of alumina fillers having an average particle diameter (D 50} ) and a ratio as shown in Table 1 below were used as the fillers included in the main part and the curing agent part, and about 84% to about 89% by weight compared to 100% by weight of the two-component resin composition % was divided and blended in equal amounts in the main part and the curing agent part. The maximum specific mass deviation of the fillers included in the main part and the curing agent part was 0.720, respectively.

Comparative Example 3

The main part and the hardening|curing agent part were the same as Example 1 used.

_{A plurality of alumina fillers having an average particle diameter (D 50} ) and a ratio as shown in Table 1 below were used as the fillers included in the main part and the curing agent part, and about 84% to about 89% by weight compared to 100% by weight of the two-component resin composition % was divided and blended in equal amounts in the main part and the curing agent part. The maximum specific mass deviation of the fillers included in the main part and the curing agent part was 0.770, respectively.

division Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 subject part hardener part subject part hardener part subject part hardener part subject part hardener part Filler type
(ratio) 70μm 6 6 - - - - 4 4 40μm - - 4 4 8 8 - - 20μm 2 2 3 3 5 5 2μm 2 2 3 3 2 2 One One

The evaluation results for the Examples and Comparative Examples are summarized in Table 2 below.

division Example 1
Comparative Example 1
Comparative Example 2
Comparative Example 3
subject part hardener part subject part hardener part subject part hardener part subject part hardener part Hardness of solids (gf) 50 43 323 458 57 45 75 45 Thermal Conductivity (W/mK) 3.0~3.2 3.0~3.2 3.0~3.2 2.9 Load factor (kgf) 25-30 25-30 50 or more 25-30 Equipment inspection cycle ○ × × ○

1: mixer
2, 2a, 2b: cartridge
3, 3a, 3b: pressurizing means
4, 4a, 4b: first discharge unit
5: mixer
6, 6a, 6b: receiving part
7: second discharge unit
10: solidification generator
11: Syringe
11a: ejection part of the syringe
12: filter
13: pressurizing means

Claims (12)

a main part comprising a main resin and a filler; and a curing agent part including a curing agent and a filler;
A two-component resin composition having a maximum packing fraction of 0.80 or more, respectively, of the fillers included in the main part and the curing agent part. According to claim 1, wherein the fillers included in the main part and the curing agent are at least a first inorganic filler having an average particle diameter of 40 μm to 120 μm, a second inorganic filler having an average particle diameter of 10 μm to 30 μm, and an average particle diameter of 5 μm or less. A two-part resin composition comprising a third inorganic filler. The two-component resin composition according to claim 1, wherein each of the fillers included in the main part and the curing agent has a sphericity of 0.95 or more. The two-part resin composition according to claim 1, wherein the filler included in the main part and the curing agent is included in an amount of 70 wt% to 95 wt% based on 100 wt% of the two-part resin composition. The two-part resin composition according to claim 1, wherein the main resin is a polyol resin, and the curing agent is a compound having polyisocyanate. The two-component resin composition according to claim 5, wherein the polyol resin is amorphous or amorphous, or an ester polyol resin having a melting point (Tm) of less than 15°C. The two-part resin composition according to claim 5, wherein the compound having polyisocyanate is a non-aromatic compound having two or more isocyanate groups. The two-component resin composition according to claim 1, wherein the load value of the main part and the curing agent part measured within 30 seconds after the curing reaction starts is 35 kgf or less. The two-part resin composition according to claim 1, wherein the cured product of the two-component resin composition has a thermal conductivity of 3.0 W/mK or more. The two-component resin composition according to claim 1, wherein the main part or the curing agent part has a resin balance of 7.6 wt% or more at 800°C in thermogravimetric analysis (TGA) of a solid produced by a solidification generator. The two-component resin composition according to claim 1, wherein the main part or the curing agent part further satisfies the following general formula 2:
[General Formula 2]
Hardness of solid (H) ≤ 200 (gf)
In the above general formula 2, H is applied to the pressing means at an arbitrary point in time when 0.3 seconds to 0.7 seconds have elapsed from when the solid material of the main part or the curing agent part is pressed at a constant velocity of 0.3 mm/s. is the force (gf). injecting a two-component resin composition into a module case having an upper plate, a lower plate, and a side wall, and having an internal space formed by the upper plate, lower plate and side wall;
accommodating a plurality of battery cells in the module case; and
and curing the resin composition to form a resin layer,
In the step of injecting the two-component resin composition, the maximum specific mass deviation of the two-component resin composition is measured, and when the measured maximum specific mass deviation meets the preset maximum specific mass deviation, the two-component resin composition is injected into the module case A method of manufacturing a battery module.

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