WO2019190106A1 - Resin composition - Google Patents

Abstract

The present application relates to a composition, a battery module, and a battery pack. According to an embodiment of the present application, a relevant manufacturing process can be improved, and a battery module having excellent insulation properties can be provided.

Description

Resin composition

Citation with Related Applications

This application claims the benefit of priority based on Korea Patent Application No. 10-2018-0035749 dated March 28, 2018 and Korea Patent Application No. 10-2019-0029277 dated March 14, 2019, the corresponding Korean patent All content disclosed in the literature of the application is included as part of this specification.

Field of technology

The present application relates to a resin composition. Specifically, the present application relates to a battery module, a battery pack, and an automobile including a resin composition and a cured product of the resin composition.

The secondary battery includes a nickel cadmium battery, a nickel hydrogen battery, a nickel zinc battery or a lithium secondary battery, and a lithium secondary battery is typical.

Lithium secondary batteries mainly use lithium oxide and carbon materials as positive and negative electrode active materials, respectively. The lithium secondary battery includes an electrode assembly in which a positive electrode active material and a negative electrode active material are respectively coated, and an electrode assembly in which a negative electrode plate is disposed with a separator interposed therebetween, and an exterior material for sealingly accommodating the electrode assembly together with an electrolyte solution. And pouch type secondary batteries. Such a single secondary battery may be referred to as a battery cell.

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

One of the methods of configuring the battery module or the battery pack as described above is to use an adhesive material to fix the plurality of battery cells inside the battery module. In this case, the adhesive material may be injected into the battery module through an injection hole formed in the surface of the battery module.

One object of the present application is to improve the implantability of a composition in an adhesive composition that can be used to fix a battery cell in a battery module.

Another object of the present application is to provide a composition capable of providing excellent insulation, adhesion, exothermicity, etc. after being injected into the battery module and cured.

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

The above and other objects of the present application can all be solved by the present application described in detail below.

In one example of the present application, the present application relates to a curable resin composition used in a battery module or a battery pack. Specifically, the composition of the present application is injected into the case of the battery module and used to fix the battery cell in the battery module after curing in contact with one or more battery cells present in the battery module, as described below. Can be. Accordingly, the resin composition may include a main component, and may include a curing agent component that may be cured when mixed with the main component. In addition, the resin composition may contain a filler as described below.

In connection with the use of the resin composition, when the curing rate of the resin composition, that is, the adhesive composition is too fast and the viscosity is high, injection into the module is not easy. On the other hand, since the viscosity of the injected liquid adhesive is not sufficiently cured, the viscosity may be low, so that the adhesive may leak or contaminate the component if the module is moved or flipped over depending on the additional process. The interface between the parts to be bonded may be raised. In view of this point, the inventors of the present application have excellent processability because they have a certain level of curing rate, and develop a resin composition that can prevent contamination or separation between parts, which may be caused by an adhesive in a battery module manufacturing process. Reached.

Accordingly, the resin composition of the present application may have curing properties at the following rates. In the present application, the curing rate of the resin composition can be expressed as a viscosity change with time.

The composition may be a composition satisfying the initial viscosity change rate, which is defined by the following relational formula 1 within the range of 1.1 to 5.0.

[Relationship 1]

Initial Viscosity Change Rate = V ₂ / V ₁

In the above relation 1, V ₁ is the initial viscosity, the viscosity value measured at room temperature within 60 seconds after mixing the components of the resin composition, that is, the main body and the curing agent, V ₂ is the resin composition measured V ₁ at room temperature Viscosity value measured after 5 min. V ₁ above And V ₂ is a viscosity value measured at the 2.5 / s point when measured in a shear rate range from 0.01 to 10.0 / s using an Rheometer (ARES). In the present application, the term "room temperature" is a state that is not particularly warmed or reduced, and any temperature within the range of about 10 ° C to 30 ° C, for example, about 15 ° C or more, about 18 ° C or more, about 20 ° C or more, Or about 23 ° C. or higher and about 27 ° C. or lower.

Satisfying the rate of change of viscosity represented by the relational formula 1 as described above means that the viscosity of the liquid adhesive composition injected at the beginning of the work for forming the battery module is maintained at a relatively low level. Thereby, sufficient process load ratio can be ensured.

In addition, the composition may be a composition satisfying the initial viscosity change rate of 10 or more defined by the following relational formula 2.

[Relationship 2]

Initial Viscosity Change Rate = V ₃ / V ₁

In the above relation 2, V ₁ is the initial viscosity, the viscosity value measured at room temperature within 60 seconds after mixing the components of the resin composition, that is, the main component and the curing agent component, V ₃ is the room temperature of the resin composition V ₁ is measured The viscosity value measured after leaving for 60 minutes at. V ₁ And V ₃ is a viscosity value measured at a 2.5 / s point when measured in a shear rate range of 0.01 to 10.0 / s using a rheometer (ARES).

As described above, satisfying the rate of change of viscosity represented by Equation 2 indicates that after 60 minutes of injecting into the battery module, the injected composition may harden to some extent to fix the battery cell inside the module case. This means that even when moved or flipped, contamination of adjacent parts or lifting between parts interfaces can be prevented.

In the present application, the V ₁ , V ₂ , And V ₃ may be referred to as a temporary curing viscosity value. In the present application, the temporary hardening state may mean that the hardened state is not reached. The hardened state is hardened enough to perform a function as an adhesive to which a material injected into the module is actually provided with a heat dissipation function to manufacture a battery module. It can mean a state that can be seen. Taking urethane resin as an example, the state of hardening is based on the NCO peak reference conversion at 2250 cm ⁻¹ , as confirmed by FT-IR analysis, based on 24-hour curing at room temperature and 30 to 70% relative humidity conditions. conversion may be found to be 80% or more.

In one example, the value of V ₁ possessed by the resin composition may be 500,000 cP or less. The lower limit may be, for example, 100,000 cP or more. When the range is satisfied, it is advantageous to satisfy the above relations 1 and 2, thereby ensuring proper fairness.

In one example, the value of V ₂ of the resin composition may be 2,000,000 cP or less. Satisfying the range means that even though a curing reaction occurs after the constituent components of the two-component resin composition described below are mixed, proper flowability still exists in the composition. When the value of V ₂ is satisfied, it is advantageous to satisfy the above-described relational expression 1, thereby ensuring proper fairness.

In another example, the value of V ₃ of the resin composition may be 5,000,000 cP or more. Satisfying this range means that the flow rate of the composition is weakened while the curing reaction takes place sufficiently during the usual time that the components of the two-component resin composition are mixed and can be injected into the battery module. It means you can fix it enough. When the value of V ₃ is satisfied, it is advantageous to satisfy the relation 2 described above, thereby ensuring proper processability and product durability.

On the premise of satisfying the relational expression 1, if necessary, a predetermined action may be additionally taken to shorten the time for achieving the viscosity value corresponding to V ₃ in the relational expression 2 above. For example, a viscosity value corresponding to V ₃ may be obtained faster by heating or heating the composition at levels that do not adversely affect the battery module components.

The kind of the resin composition is not particularly limited as long as it satisfies the curing rate characteristic associated with the above-defined viscosity and has curing property suitable for the use after curing.

In one example, a room temperature curable composition may be used as the resin composition. The room temperature curable composition means a composition having a system capable of exhibiting a predetermined adhesive ability through a curing reaction at room temperature. For example, a two-component silicone resin composition, a two-component urethane resin composition, and a two-component epoxy resin composition. Or a two-component acrylic resin composition.

In one example, the resin composition may provide excellent electrical insulation after curing (hardening). When the resin layer exhibits electrical insulation in the battery module structure described below, the performance of the battery module can be maintained and stability can be ensured. For example, when 24 hours after mixing the components of the resin composition, that is, the main material and the curing agent, the breakdown voltage of the cured product is measured, the breakdown voltage is about 10 kV / mm or more, 15 kV / mm or more, or 20 kV / mm or more. The higher the numerical value of the dielectric breakdown voltage, the better the insulating property of the resin layer. Therefore, the upper limit is not particularly limited, but considering the composition of the resin layer or the like, 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. The dielectric breakdown voltage can be measured according to ASTM D149, as described in the following examples. In addition, the dielectric breakdown voltage in the above range can be ensured, for example, by adjusting the filler or resin component or the content thereof used in the curable composition described below.

In one example, the composition may be a two-component urethane-based composition. Two-component urethane means a polyurethane formed by mixing an isocyanate compound and a polyol compound, and is distinguished from a one-component polyurethane having a urethane group in a single composition. When a two-component urethane-based composition is used, the composition may have the following configuration. In the case of the two-component polyurethane, a main agent including a polyol and a curing agent including an isocyanate may be reacted at room temperature to cure. The curing reaction may be aided by a catalyst, for example dibutyltin dilaurate (DBTDL). Accordingly, the two-component urethane-based composition may include a physical mixture of the main component (polyol) and the hardener component (isocyanate), and / or may include a reactant (cured product) of the main component and the hardener component.

The two-component urethane composition may include a main composition part (or main part) including at least a polyol resin, and a hardener composition part (or hardener part) including at least polyisocyanate. Accordingly, the cured product of the resin composition may include both the polyol-derived unit and the polyisocyanate-derived unit. In this case, the polyol-derived unit may be a unit formed by a polyol reacting with a polyisocyanate and a urethane, and the polyisocyanate-derived unit may be a unit formed by reacting a polyol with a urethane.

The composition may also include a filler. For example, to ensure thixotropy as needed in the process, and / or to ensure heat dissipation (thermal conductivity) in a battery module or battery pack, the composition of the present application may have excess fillers as described below. May be included. Details are described in detail in the following description.

In one example, an ester-based polyol resin may be used as the polyol resin included in the subject composition part. In the case of using an ester-based polyol, it is advantageous to ensure excellent adhesion and adhesion reliability in the battery module after curing the resin composition.

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

The carboxylic acid-based polyol may be formed by reacting a component including a carboxylic acid and a polyol (ex. Diol or triol, etc.), and the caprolactone-based polyol may include caprolactone and a polyol (ex. Diol or triol). It can form by making a component react. 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 carboxylic acid, and Y is a unit derived from polyol. The unit derived from a polyol may be a triol unit or a diol unit, for example. Also, n and m can be any number.

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

That is, when the hydroxyl group of the polyol and the carboxyl group of the carboxylic acid react, water (HO ₂ ) molecules are detached by the condensation reaction, and an ester bond is formed. In Formula 1, X represents the carboxylic acid forming an ester bond by the condensation reaction. After that means a portion except the ester bond portion. In addition, Y is a part except the ester bond after a polyol forms an ester bond by the said condensation reaction. The ester bond is shown in the formula (1).

In addition, Y of the formula (2) also represents a portion excluding the ester bond after the polyol forms an ester bond with the caprolactone. The ester bond is shown in the formula (2).

Meanwhile, when the polyol-derived unit of Y in the formula is a unit derived from a polyol including three or more hydroxy groups, such as a triol unit, a structure in which a branch is formed in the Y part in the formula structure may be implemented.

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, phthalic acid units, isophthalic acid units, terephthalic acid units, trimellitic acid units, tetrahydrophthalic acid units, hexahydrophthalic acid units, Tetrachlorophthalic acid unit, oxalic acid unit, adipic acid unit, azelaic acid unit, sebacic acid unit, succinic acid unit, malic acid unit, glataric acid unit, malonic acid unit, pimelic acid unit, suberic acid unit, 2,2-dimethyl It may be any one unit selected from the group consisting of succinic 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. . In view of the low glass transition temperatures in the above-described ranges, aliphatic carboxylic acid derived units may be preferred over aromatic carboxylic acid derived units.

On the other hand, the type of the polyol-derived unit of Y in the general formula (1) and (2) is not particularly limited, in order to ensure the desired physical properties, ethylene glycol units, diethylene glycol units, propylene glycol units, 1,2-butylene glycol units, 2,3-butylene glycol unit, 1,3-propanediol unit, 1,3-butanediol unit, 1,4-butanediol unit, 1,6-hexanediol unit, neopentyl glycol unit, 1,2-ethylhexyl Diol units, 1,5-pentanediol units, 1,9-nonanediol units, 1,10-decanediol units, 1,3-cyclohexanedimethanol units, 1,4-cyclohexanedimethanol units, glycerin units and It may be any one or more selected from the group consisting of trimethylolpropane units.

Meanwhile, n in Formula 1 may be any number, and the range may be selected in consideration of the desired physical properties of the resin composition or the cured resin layer thereof. For example, n may be about 2-10 or 2-5.

In addition, m in the formula (2) is an arbitrary number, the range may be selected in consideration of the desired physical properties of the resin composition or the cured resin layer thereof, m is about 1 to 10 or 1 to 5 days Can be.

When n and m in the formulas (1) and (2) are out of the above ranges, the crystalline expression of the polyol may become stronger and may adversely affect the injection processability of the composition.

The molecular weight of the polyol may be adjusted in consideration of the low viscosity characteristics, durability, or adhesiveness described below, for example, may be in the range of about 300 to 2,000. Unless otherwise specified, in the present specification, "molecular weight" may be a weight average molecular weight (Mw) measured using GPC (Gel Permeation Chromatograph). If it is out of the above range, the resin layer may not be reliable after curing, or problems related to volatile components may occur.

In the present application, the polyisocyanate may mean a compound including two or more isocyanate groups.

In the present application, the type of polyisocyanate included in the curing agent composition portion is not particularly limited, but a non-aromatic isocyanate compound containing no aromatic group may be used to secure desired physical properties. That is, it may be advantageous to use aliphatic or cycloaliphatic series. When using an aromatic polyisocyanate, since the reaction rate is too fast and the glass transition temperature of the cured product may be high, it may be difficult to secure processability and physical properties suitable for use of the present application composition.

For example, aliphatic or alicyclic cyclic polyisocyanates or modified substances thereof can be used. Specifically, aliphatic polyisocyanate, such as hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate, norbornane diisocyanate methyl, ethylene diisocyanate, propylene diisocyanate or tetramethylene diisocyanate; Aliphatic cyclic polyisocyanates such as transcyclohexane-1,4-diisocyanate, isophorone diisocyanate, bis (isocyanatemethyl) cyclohexane diisocyanate or dicyclohexylmethane diisocyanate; Or at least one of the above carbodiimide-modified polyisocyanates and isocyanurate-modified polyisocyanates; And the like can be used. In addition, mixtures of two or more of the compounds listed above may be used.

The ratio of the polyol-derived resin component and the polyisocyanate-derived resin component in the resin composition is not particularly limited and may be appropriately adjusted to enable the urethane reaction therebetween.

As described above, in order to secure heat dissipation (thermal conductivity) or in order to obtain thixotropy according to a process necessity, an excess filler may be included in the composition. The processability when injecting the composition into the case may be worse. Therefore, there is a need for a low viscosity characteristic sufficient to include an excess of filler but not to interfere with fairness. In addition, simply showing a low viscosity, it is also difficult to ensure the fairness, and therefore appropriate thixotropy is required, exhibits excellent adhesion as cured, the curing itself may need to proceed at room temperature. In addition, the ester-based polyol is advantageous for securing adhesiveness after curing, but is highly likely to be in a wax state at room temperature because of its strong crystallinity, and has an unfavorable aspect of securing proper injection processability due to an increase in viscosity. Even if the viscosity is lowered through melting, the crystallinity naturally occurring during the storage process causes a viscosity increase due to crystallization in the injection or application process of the composition which may follow after mixing with the filler. As a result, fairness may be reduced. In consideration of this point, the ester polyol used in the present application may satisfy the following characteristics.

In the present application, the ester-based polyol may be amorphous or polyol having a low enough crystallinity. "Amorphous" means the case where no crystallization temperature (Tc) and melting temperature (Tm) are observed in DSC (Differential Scanning calorimetry) analysis. The DSC analysis can be performed using a known device, for example, Q2000 (TA instruments). Specifically, the DSC analysis can be carried out in the range of -80 to 60 ℃ at a rate of 10 ℃ / min (min), for example, after the temperature is raised from 25 ℃ to 50 ℃ at the rate-to 70 ℃ The temperature may be reduced, and the temperature may be raised to 50 ° C. In addition, the above-mentioned "low enough crystallinity" means that the melting point or melting temperature (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, It means the case of -10 degrees C or less, or -20 degrees C 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, about −75 ° C. or more, or about −70 ° C. or more. In the case where the polyol is crystalline or has a strong (room temperature) crystallinity such as not satisfying the melting point range, the viscosity difference with temperature tends to be large, so that the filler dispersion and the viscosity of the final mixture in the process of mixing the filler and the resin It may adversely affect, lower the processability, and as a result it may be difficult to meet the cold resistance, heat resistance and water resistance required in the adhesive composition for the battery module.

FIG. 1 is a graph showing the results of DSC analysis on several polyols as an example of determining the amorphous properties or low enough crystallinity of the ester polyol. According to the present application, Sample # 1 may be determined to be amorphous, and Samples # 2 and # 3 may be judged to be sufficiently low in crystallinity. On the other hand, in the case of Sample # 4 having a melting temperature (Tm) of 33.52 ° C., it can be said that the crystallinity is high.

In one example, the polyol resin and the isocyanate component included in the urethane-based composition may have a glass transition temperature (Tg) of less than 0 ° C. after curing (curing curing).

When the glass transition temperature range is satisfied, the brittle characteristic can be secured within a relatively short time even at a low temperature at which the battery module or the battery pack can be used, and thus shock resistance and vibration resistance can be ensured. Can be. On the other hand, when the said range is not satisfied, there exists a possibility that the adhesiveness (tacky) of hardened | cured material may be too high or thermal stability may fall. In one example, the lower limit of the glass transition temperature of the urethane-based composition after curing may be-70 ℃ or more,-60 ℃ or more,-50 ℃ or more,-40 ℃ or more or-30 ℃ or more, the upper limit is-5 C or less, -10 degrees C or less, -15 degrees C or less, or -20 degrees C or less. The glass transition temperature may be measured after curing the polyol resin and the isocyanate component (not including filler).

In addition, in the present application, in order to secure the required function according to the use of the resin composition and its use, an additive may be used. For example, the resin composition may include a predetermined filler in consideration of thermal conductivity, insulation, heat resistance (TGA analysis), and the like of the resin layer. The form or method in which a filler is contained in a resin composition is not specifically limited. For example, the filler may be used to form the urethane-based composition in a state previously contained in the main composition portion and / or the curing agent composition portion. Alternatively, in the process of mixing the main composition portion and the curing agent composition portion, it may also be used in a manner that the fillers prepared separately are mixed together.

In at least one example, the filler included in the composition may be a thermally conductive filler. As used herein, the term thermally conductive filler may refer to 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 may be about 400 W / mK or less, about 350 W / mK or less or about 300 W / mK or less. The type of thermally conductive filler that can be used is not particularly limited, but may be a ceramic filler in consideration of insulation and the like. For example, ceramic particles such as alumina, aluminum nitride (AlN), boron nitride (BN), silicon nitride, SiC, or BeO may be used. The form or ratio of the filler is not particularly limited, and is appropriately adjusted in consideration of the viscosity of the urethane-based composition, the possibility of sedimentation in the cured resin layer, the desired thermal resistance or thermal conductivity, insulation, filling effect or dispersibility, and the like. Can be. In general, the larger the size of the filler, the higher the viscosity of the composition including the same, and the higher the possibility that the filler precipitates in the resin layer. In addition, the smaller the size, the higher the heat resistance tends to be. Therefore, in consideration of the above point, a filler of an appropriate type and size may be selected, and two or more fillers may be used together if necessary. In addition, it is advantageous to use a spherical filler in consideration of the filling amount, but fillers in the form of a needle or plate may be used in consideration of the formation of a network or conductivity. The thermal conductivity of the filler can be measured according to known methods, wherein the thermal conductivity of the filler can be measured by melting the filler and making a specimen.

In one example, the composition may include a thermally conductive filler having an average particle diameter in the range of 0.001 μm to 80 μm. In another example, the average particle diameter of the filler may be at least 0.01 μm, at least 0.1 μm, at least 0.5 μm, at least 1 μm, at least 2 μm, at least 3 μm, at least 4 μm, at least 5 μm, or at least about 6 μm. The average particle diameter of the filler is, in another example, 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 diameter may be measured using a particle size analysis (PSA) instrument. In one example, the average particle diameter may mean D (50), which is the particle size of the 50th rank, when ranking the particles from size 1 to 100 by size.

In order to obtain excellent heat dissipation performance, it may be considered that a high content of thermally conductive filler is used. For example, the filler may be used in the range of about 50 to 2,000 parts by weight, based on 100 parts by weight of the total resin component, that is, the total content of the ester-based polyol resin and the polyisocyanate. In another example, the filler content may be used in excess of the total resin component. Specifically, based on 100 parts by weight of the total content of the ester-based polyol resin and polyisocyanate, 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, At least about 350 parts by weight, at least about 400 parts by weight, at least about 500 parts by weight, at least about 550 parts by weight, at least about 600 parts by weight or at least about 650 parts by weight of fillers may be used. In one example, when the filler is used in the above range, it may be dispensed in the same amount in the main composition portion and the curing agent composition portion.

As described above, when the thermally conductive filler is used in a high content, the viscosity of the main composition portion, the hardener composition portion, or the composition including the filler may be increased. As described, the injection processability is not good when the viscosity of the resin composition is too high, and thus the physical properties required for the resin layer may not be sufficiently implemented throughout the resin layer. In view of this point, it is preferable to use a low viscosity component that can be liquid or have sufficient flow as the resin component.

In one example, each of the ester-based polyol resin and the polyisocyanate component may have a viscosity of 10,000 cP or less. Specifically, the resin component may have a viscosity of 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 may 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 may be 50 cP or more or 100 cP or more. If the viscosity is too low, the fairness may be good, but as the molecular weight of the raw material is lowered, the likelihood of volatilization may increase, and heat resistance / cold resistance, flame retardancy, and adhesive strength may deteriorate. Such disadvantages may be prevented by satisfying the lower limit. The viscosity of the resin can be measured at room temperature, for example using a Brookfield LV type viscometer.

In addition to the above, various kinds of fillers may be used. For example, in order to secure the insulating properties of the resin layer on which the resin composition is cured, the use of a carbon (based) filler such as graphite may be considered. Alternatively, for example, fillers such as fumed silica, clay or calcium carbonate may be used. The form or content ratio of the filler is not particularly limited and may be selected in consideration of the viscosity of the resin composition, the possibility of sedimentation in the resin layer, thixotropy, insulation, filling effect or dispersibility.

The composition may contain a viscosity modifier such as a thixotropic agent, a diluent, a dispersant, a surface treatment agent or a coupling agent to adjust the required viscosity, for example to increase or decrease the viscosity or to adjust the viscosity according to shear force. It may be additionally included.

The thixotropic agent may adjust the viscosity according to the shear force of the resin composition so that the manufacturing process of the battery module is effectively performed. Examples of the thixotropic agent that can be used include fumed silica and the like.

Diluents or dispersants are usually used to lower the viscosity of the resin composition, so long as they can exhibit the same action can be used without limitation various kinds known in the art.

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

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

In addition, the resin composition may further include a flame retardant or a flame retardant aid. In this case, a known flame retardant may be used without particular limitation, and for example, a solid filler-type flame retardant or a liquid flame retardant may 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 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 may be added that can act as a flame retardant synergist.

The composition may include a composition as described above, and may also be a solvent-type composition, an aqueous composition, or a solvent-free composition, but considering the convenience of the manufacturing process described below, a solvent-free type may be appropriate.

The composition of the present application may have physical properties suitable for the uses described below after curing. If the measurement temperature affects the physical properties among the physical properties mentioned in the present specification, the physical properties may be physical properties measured at room temperature unless otherwise stated. In addition, in relation to physical properties, the expression "after curing" may be used in the same meaning as the above-described curing.

In one example, the resin composition may have a predetermined adhesive strength (S ₁ ) at room temperature after curing. Specifically, the resin layer may have an adhesive strength of about 150 gf / 10mm or more, 200 gf / 10mm or more, 250 gf / 10mm or more, 300 gf / 10mm or more, 350 gf / 10mm or more or 400 gf / 10mm or more. When the adhesive force 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 for example, 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 500 gf / It may be about 10 mm or less. If the adhesion is too high, there is a risk of tearing of the cured composition and the portion of the pouch to which it is attached. Specifically, in the event of an accident while driving a car, the impact of the shape of the battery module deforms, if the battery cell is adhered too hard through the hardened resin layer, the pouch is torn and the dangerous substance inside the battery is exposed or exploded. can do. The adhesion can be measured against an aluminum pouch. For example, an aluminum pouch used for fabricating a battery cell is cut to a width of about 10 mm, a resin composition is loaded onto a glass plate, and the cut aluminum pouch is placed on the pouch (poly (ethylene terephthalate) (PET) of the pouch. The resin composition was cured for 24 hours at 25 ° C. and 50% RH after loading the resin composition into contact with the surface, and the aluminum pouch was peeled at 180 ° and 300 mm / min by a tensile analyzer. The adhesive force can be measured while peeling at a peeling rate of.

In another example, the adhesive strength after curing of the resin composition may be maintained at a considerable level even under high temperature / high humidity. Specifically, in the present application, with respect to the adhesive strength (S ₁ ) after curing measured at room temperature, the percentage of adhesive force (S ₂ ) measured by the same method after the high temperature / high humidity acceleration test performed under a predetermined condition The ratio [(S ₂ / S ₁ ) × 100] may be at least 70%, or at least 80%. In one example, the high temperature / high humidity acceleration test may be measured after storing the same specimen as the one used to measure the room temperature adhesion force for 10 days at 40-100 ° C. temperature and 75% RH or higher humidity condition. When the adhesive force and the relationship are satisfied, even when the use environment of the battery module is changed, excellent adhesion durability may be maintained.

In one example, the resin composition may have excellent heat resistance after curing. In this regard, the composition of the present application does not include a filler, the temperature of 5% weight loss during thermogravimetric analysis (TGA) measured on the cured product of only the resin component is 120 ℃ It may be abnormal. In addition, the composition of the present application, in the state including a filler, in the thermogravimetric analysis (TGA) measured for the cured product of the resin composition, the residual amount of 800 ℃ may be 70% by weight or more. The balance of 800 ° C. may be at least about 75 wt%, at least about 80 wt%, at least about 85 wt%, or at least about 90 wt%. The residual amount of 800 ° C. may be about 99% by weight or less in another example. In this case, the thermogravimetric analysis (TGA) may be measured in a range of 25 to 800 ° C. at a temperature rising rate of 20 ° C./min in an atmosphere of nitrogen (N ₂ ) of 60 cm ³ / min. Heat resistance characteristics associated with the thermogravimetric analysis (TGA) can be secured by adjusting the type of resin and / or filler or their content.

In another example relating to the present application, the present application relates to a battery module. The module includes a module case and a battery cell. The battery cell may be stored in the module case. One or more battery cells may be present in the module case, and a plurality of battery cells may be stored in the module case. The number of battery cells housed in the module case is not particularly limited to be adjusted according to the use. The battery cells stored in the module case may be electrically connected to each other.

The module case may include at least a side wall and a bottom plate forming an inner space in which the battery cells can be stored. In addition, the module case may further include a top plate for sealing the inner space. The side wall, the lower plate and the upper plate may be integrally formed with each other, or separate sidewalls, the lower plate and / or the upper plate may be assembled to form the module case. The shape and size of such a module case are not particularly limited, and may be appropriately selected according to the use or the shape and number of battery cells accommodated in the internal space.

In the above terms, the upper plate and the lower plate are terms of a relative concept used to distinguish them because at least two plates constituting the module case exist. That is, it does not mean that the upper plate must be present at the top, and the lower plate must be present at the bottom in the actual use state.

FIG. 2 shows an exemplary module case 10 and is an illustration of a case 10 in the form of a box comprising one bottom plate 10a and four side walls 10b. The module case 10 may further include a top plate 10c that seals the internal space.

FIG. 3 is a schematic view of the module case 10 of FIG. 2 in which the battery cells 20 are housed.

Holes 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, a resin composition, when the resin layer is formed by an injection process, as described below. The shape, number and position of the holes can be adjusted in consideration of the 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.

In one example, the hole may be formed at about 1/4 to 3/4 or about 3/8 to 7/8 of the entire length of the side wall, the bottom plate or the top plate, or about the middle portion. By injecting the resin composition through the injection hole formed at this point, it is possible to inject the resin layer to have a wide contact face foot. The 1/4, 3/4, 3/8 or 7/8 point is the total length (L) measured based on any one end surface E of the lower plate or the like, for example, as shown in FIG. ) Is the ratio of the distance A to the formation position of the hole. In addition, the terminal (E) in which the length (L) and the distance (A) are formed in the above may be any terminal (E) as long as the length (L) and the distance (A) are measured from the same terminal (E). have. In FIG. 4, the injection hole 50a is positioned at an approximately middle portion of the lower plate 10a.

The size and shape of the injection hole is not particularly limited and may be adjusted in consideration of the injection efficiency of the resin layer material described later. For example, the hole may be polygonal or amorphous, such as a circle, an oval, a triangle or a rectangle. The number and spacing of the injection holes is not particularly limited, and as described above, the resin layer may be adjusted to have a wide contact area with the lower plate.

Observation holes (eg, 50b of FIG. 4) may be formed at ends of the upper plate and the lower plate on which the injection holes are formed. For example, the observation hole 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 to confirm whether the injected material is properly injected.

The module case may be a thermally conductive case. The term thermally conductive case means a case including a portion having a thermal conductivity of 10 W / mk or more or at least having the above-described thermal conductivity of the entire case. For example, at least one of the above-described sidewalls, bottom plate and top plate may have the thermal conductivity described above. In another example, at least one of the sidewall, the bottom plate, and the top plate may include a portion having the thermal conductivity. For example, the battery module of the present application may include a first filler-containing cured resin layer in contact with an upper plate and a battery cell, and a second filler-containing cured resin layer in contact with a lower plate and a battery cell, as described below. At least the second filler-containing cured resin layer may be a thermally conductive resin layer, and thus, at least the lower plate may have a thermal conductivity or may include a thermally conductive portion.

The thermal conductivity of the top plate, bottom plate, side wall, or thermally conductive portion, which is thermally conductive above, is, in another example, 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, 130 W / mk or more, 130 W / mk or more, 140 W / mk or more , At least 150 W / mk, at least 160 W / mk, at least 170 W / mk, at least 180 W / mk, at least 190 W / mk, or at least 195 W / mk. The higher the thermal conductivity is, the more advantageous it is 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, It may be 300 W / mk or 250 W / mK or less, but is not limited thereto. The kind of the material which exhibits the above thermal conductivity is not particularly limited, and examples thereof include metal materials such as aluminum, gold, pure silver, tungsten, copper, nickel or platinum. The module case may be entirely made of such a thermally conductive material, or at least a part of the module case may be a portion of the thermally conductive material. Accordingly, the module case may have a thermal conductivity in the above-mentioned range, or may include at least one region having the above-mentioned thermal conductivity.

In the module case, a portion having thermal conductivity in the above range may be a portion in contact with a resin layer and / or an insulating layer, which will be described later. In addition, the portion having the thermal conductivity may be a portion in contact with a cooling medium such as cooling water. With such a structure, heat generated from the battery cells can be effectively released to the outside.

The type of battery cell accommodated in the module case is also not particularly limited, and various known battery cells may be applied. In one example, the battery cell may be a pouch type. Referring to FIG. 5, the pouch-type battery cell 100 may typically include an electrode assembly, an electrolyte, and a pouch sheath.

5 is an exploded perspective view schematically showing the configuration of an exemplary pouch-type cell, and FIG. 6 is a combined perspective view of the configuration of FIG. 5.

The electrode assembly 110 included in the pouch-type cell 100 may have a form in which one or more positive electrode plates and one or more negative electrode plates are disposed with a separator therebetween. The electrode assembly 110 may be a winding type in which one positive electrode plate and one negative electrode plate are wound together with a separator, or a stack type in which a plurality of positive electrode plates and a plurality of negative electrode plates are alternately stacked with a separator interposed therebetween.

The pouch packaging material 120 may be configured to include, for example, an outer insulating layer, a metal layer, and an inner adhesive layer. The exterior member 120 may include a metal thin film such as aluminum in order to protect internal elements such as the electrode assembly 110 and the electrolyte, and to compensate for the electrochemical properties of the electrode assembly 110 and the electrolyte and to provide heat dissipation. Can be. The metal thin film may be interposed between an insulating layer formed of an insulating material in order to ensure electrical insulation between the electrode assembly 110 and other elements such as an electrolyte or other elements outside the battery 100. In addition, the pouch may further include a polymer resin layer (base material) such as PET.

In one example, the exterior member 120 may include an upper pouch 121 and a lower pouch 122, and at least one of the upper pouch 121 and the lower pouch 122 may have a concave inner space I. This can be formed. The electrode assembly 110 may be accommodated in the internal space I of the pouch. Sealing portions S may be provided on the outer circumferential surfaces of the upper pouch 121 and the lower pouch 122, and the sealing portions S may be adhered to each other to seal an inner space in which the electrode assembly 110 is accommodated.

Each electrode plate of the electrode assembly 110 includes an electrode tab, and one or more electrode tabs may be connected to the electrode lead. The electrode lead is interposed between the sealing portion S of the upper pouch 121 and the lower pouch 122 to be exposed to the outside of the exterior member 120, thereby functioning as an electrode terminal of the secondary battery 100.

The shape of the pouch-type cell described above is just one example, and the battery cell to which the present application is applied is not limited to the above kind. In the present application, various well-known pouch-type cells or other types of batteries may be applied as battery cells.

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 urethane-based composition described above.

The battery module may include, as the resin layer, a first filler-containing cured resin layer in contact with the upper plate and the battery cell, and a second filler-containing cured resin layer in contact with the lower plate and the battery cell. At least one of the first and second filler-containing cured resin layers may comprise a cured product of the urethane-based composition described above, and thus may have the predetermined adhesion, cold resistance, heat resistance, and insulation as described above. In addition, the 1st and 2nd filler containing cured resin layer can have the following characteristics.

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 1.5 W / mK or more, about 2 W / mK or more, 2.5 W / mK or more, 3 W / mK or more, 3.5 W / mK or more, or 4 W / mK or more. . The thermal conductivity is 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 a thermally conductive resin layer as described above, the lower plate, the upper plate, and / or the sidewall on which the resin layer is attached may be a portion having the above-described thermal conductivity of 10 W / mK or more. At this time, the portion of the module case showing the thermal conductivity may be a portion in contact with a cooling medium, for example, cooling water. The thermal conductivity of the resin layer is measured using a known hot disk device, for example, a numerical value measured according to ASTM D5470 standard or ISO 22007-2 standard. The thermal conductivity of the resin layer as described above can be ensured, for example, by appropriately adjusting the filler contained in the resin layer and its content ratio as described above.

In one example, the thermal resistance of the resin layer or the battery module to which the resin layer is applied in the battery module is 5 K / W or less, 4.5 K / W or less, 4 K / W or less, 3.5 K / W or less, 3 K Or less than or about 2.8 K / W. When the resin layer or the battery module to which the resin layer is applied is adjusted so that the heat resistance in the above range is shown, excellent cooling efficiency or heat radiation efficiency can be ensured. The measurement of the thermal resistance can be calculated based on the temperature measured from the sensor, attaching a temperature sensor according to the cell position on the module while driving the battery module. The method of measuring the thermal resistance is not particularly limited, and for example, the thermal resistance may be measured according to ASTM D5470 standard or ISO 22007-2 standard.

In one example, the resin layer may be a resin layer formed to maintain durability even in a predetermined thermal shock test. Thermal shock testing can be performed in a manner known in the art. For example, when the temperature is maintained at a low temperature of about -40 ° C for 30 minutes and then the temperature is raised to 80 ° C for 30 minutes as a cycle, the module case of the battery module or The resin layer may be peeled off from the battery cell or cracks may not occur. For example, when the battery module is applied to a product that requires a long warranty period (about 15 years or more in the case of an automobile) such as an automobile, the above level of performance may be required to secure durability.

In one example, the resin layer may be a flame retardant resin layer. As used herein, the term flame retardant resin layer may refer to a resin layer having a V-0 rating in a UL 94 V Test (Vertical Burning Test). This ensures stability against fire and other accidents that may occur in the battery module.

In one example, the resin layer may have a specific gravity of 5 or less. In another example, the specific gravity may be 4.5 or less, 4 or less, 3.5 or less, or 3 or less. The resin layer exhibiting specific gravity in this range is advantageous for the production of a lighter battery module. The lower the specific gravity is, the more advantageous the weight of the module is. Therefore, the lower limit thereof is not particularly limited. For example, the specific gravity may be about 1.5 or more or 2 or more. In order for the resin layer to exhibit specific gravity in the above range, components added to the resin layer may be adjusted. For example, when the filler is added, a filler capable of securing a desired thermal conductivity even at a low specific gravity as much as possible, that is, a filler having a low specific gravity or a surface-treated filler may be used.

In one example, the resin layer preferably does not contain a volatile material. For example, the resin layer may have a ratio of nonvolatile content of 90 wt% or more, 95 wt% or more, or 98 wt% or more. In the above, the nonvolatile components and their proportions can be defined in the following manner. That is, the part which remains after maintaining a resin layer at 100 degreeC for about 1 hour can be defined as a nonvolatile component. Therefore, the ratio of the nonvolatile component can be measured based on the initial weight of the resin layer and the ratio after maintaining for 1 hour at 100 ° C.

In one example, it may be advantageous that the resin layer has a low shrinkage after curing or after curing. Through this, it is possible to prevent peeling or the generation of voids that may occur during the manufacture or use of the module. The shrinkage rate may be appropriately adjusted in a range capable of exhibiting the above-described effects, for example, may be less than 5%, less than 3% or less than about 1%. Since the said shrinkage rate is so advantageous that the numerical value is low, the minimum in particular is not restrict | limited.

In one example, the resin layer may have a low coefficient of thermal expansion (CTE) in order to prevent peeling or the generation of voids that may occur during the manufacture or use of the module. The thermal expansion coefficient can 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. Since the said coefficient of thermal expansion is so advantageous that the numerical value is low, the minimum in particular is not restrict | limited. The method for measuring the thermal expansion coefficient is not particularly limited. For example, using a TMA (Thermo Mechanical Analyze) to measure in the expansion mode, 0.05N load at -40 to 125 degrees 5 ℃ / min conditions, to determine the length strain within a specified temperature range based on the modified length Thermal expansion coefficient can be measured.

In one example, in order to impart excellent durability or impact 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 more. Young's modulus is measured in tensile mode at low temperature (about -40 ° C), room temperature (about 25 ° C), and high temperature (about 80 ° C) for each point within a range of -40 to 80 ° C, for example. It may be a slope value. Young's modulus is measured at higher temperatures. For example, the resin layer of the present application may have a Young's modulus of 1.0 Mpa or more, more specifically, 10 to 500 Mpa within the above section. If the Young's modulus is less than the above range, the function of fixing a large weight of the cell is not good, and if the Young's modulus is too large, the brittle characteristic is strong, so that a crack may occur in an impact situation such as a vehicle crash.

In one example, it may be advantageous that the resin layer exhibits an appropriate hardness. For example, when the hardness of the resin layer is too high, since the resin layer has brittle characteristics, it may adversely affect reliability. In view of such a point, by controlling the hardness of the resin layer, it is possible to secure impact resistance and vibration resistance and to secure durability of the product. The resin layer may, for example, have a hardness in Shore A type of less than 100, 99 or less, 98 or less, 95 or less, or 93 or less, or hardness in Shore D type of less than about 80, about 70 or less, or about 65 or less or about 60 or less. The lower limit of the hardness is not particularly limited. For example, the hardness may be about 60 or more in Shore A type, or about 5 or about 10 or more in Shore 00 type. Hardness of the above range can be secured by adjusting the content of the filler. Shore hardness can be measured according to known methods using a hardness meter for each type, such as, for example, shore A hardness meter. Known methods include ASTM D2240 and the like.

By forming a cured resin layer that satisfies the above characteristics in the battery module as described above, a battery module having excellent durability against external shock or vibration can be provided.

In the battery module of the present application, at least one of the sidewalls, the bottom plate, and the top plate contacting the resin layer may be the above-described thermally conductive sidewall, the bottom plate, or the top plate. On the other hand, the term contact in the present specification is, for example, the resin layer and the top plate, bottom plate and / or side wall or battery cells are in direct contact, or other elements, for example, an insulating layer or the like therebetween. It may mean a case. Further, the resin layer in contact with the thermally conductive sidewall, the bottom plate or the top plate may be in thermal contact with the object. In this case, the thermal contact is such that the resin layer is in direct contact with the lower plate or the like, or there is another element between the resin layer and the lower plate, for example, an insulating layer to be described later. It may mean a state that does not interfere with the transfer of heat from the battery cell to the resin layer and the resin layer to the lower plate. In the above, not impeding the transfer of heat, even if there is another element (eg an insulating layer or a guiding part described later) between the resin layer and the lower plate, the overall thermal conductivity of the other element and the resin layer. Is at least about 1.5 W / mK, at least about 2 W / mK, at least 2.5 W / mK, at least 3 W / mK, at least 3.5 W / mK, or at least 4 W / mK, or in contact with the resin layer and the It means the case that the overall thermal conductivity of the lower plate, such as being included in the above range even if there is the other element. The thermal conductivity of the thermal contact is 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 can be achieved by controlling the thermal conductivity and / or thickness of the other element, if such other element is 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. By adopting the structure as described above, it is possible to secure heat dissipation characteristics while significantly reducing various fastening components or cooling equipment of modules that are required in the conventional battery module or a battery pack that is a collection of such modules. It is possible to implement a module that accommodates more battery cells per unit. Accordingly, in the present application, it is possible to provide a battery module having a smaller size, light weight, and high power.

7 is an exemplary cross-sectional view of the battery module. In FIG. 6, the module includes a case 10 including a side wall 10b and a bottom plate 10a; It may have a form including a plurality of battery cells 20 stored in the case and the resin layer 30 in contact with both the battery cell 20 and the case 10. Although FIG. 7 is a view of the resin layer 30 existing on the lower plate 10a side, the battery module of the present application may include a resin layer positioned in the same shape as FIG. 7 on the upper plate side.

In the structure, the lower plate and the like contacting with the resin layer 30 may be a thermally conductive lower plate and the like as described above.

The contact area of the resin layer and the lower plate 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 relative to the total area of the lower plate or the like. The upper limit of the contact area is not particularly limited, and may be, for example, 100% or less or less than about 100%.

When the upper plate or the lower plate is thermally conductive, and the cured resin layer in contact with it is also thermally conductive, the thermally conductive portion or the thermally conductive lower plate may be a portion in contact with a cooling medium such as cooling water. That is, as shown schematically in FIG. 7, heat (H) can be easily discharged to the lower plate and the like by the above structure, and by contacting the lower plate and the like with the cooling medium (CW), even in a more simplified structure The heat can be released easily.

Each of the first and second cured resin layers may have a thickness, for example, in the range of about 100 μm to 5 mm or in the range of about 200 μm to 5 mm. In the structure of this application, the thickness of the said resin layer can be set to an appropriate thickness in consideration of target heat dissipation characteristic and durability. The thickness may be the thickness of the thinnest portion, the thickness of the thickest portion, or the average thickness of the resin layer.

As shown in FIG. 7, at least one surface of the inside of the module case 10, for example, a surface 10a in contact with the resin layer 30, may include a guiding part configured to guide the battery cell 20 to be accommodated. 10d) may be present. At this time, the shape of the guiding part 10d is not particularly limited, and an appropriate shape may be adopted in consideration of the shape of the battery cell to be applied. The guiding part 10d may be formed integrally with the lower plate or the like, or may be separately attached. The guiding part 10d may be formed using a thermally conductive material, for example, a metal material such as aluminum, gold, pure silver, tungsten, copper, nickel or platinum in consideration of the thermal contact described above. In addition, although not shown in the drawings, a gap sheet or an adhesive layer may exist between the battery cells 20 to be accommodated. The interleaver may serve as a buffer when charging and discharging the battery cell.

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. FIG. 8 exemplarily shows a case where the insulating layer 40 is formed between the guiding portion 10d and the resin layer 30 formed on the lower plate 10a of the case. By adding an insulating layer, it is possible to prevent problems such as an electrical short circuit or fire caused by contact between the cell and the case due to the impact that may occur during use. The insulating layer may be formed using an insulating sheet having high insulation and thermal conductivity, or may be formed by coating or injecting a material exhibiting insulation. For example, in the method of manufacturing a battery module described below, a process of forming an insulating layer may be performed before the injection of the resin composition. 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, and for example, the insulating layer may be formed using a resin layer having little or no filler such as a thermally conductive filler. Examples of the resin component that can be used to form the insulating layer include acrylic resins, olefin resins such as PVC (poly (vinyl chloride)) and PE (polyethylene), epoxy resin, silicone, and EPDM rubber (ethylene propylene diene monomer rubber). Rubber components, such as, but not limited to, etc. The insulating layer has an insulation breakdown voltage measured in accordance with ASTM D149 of about 5 kV / mm or more, about 10 kV / mm or more, about 15 kV / kmm or more, 20 kV / mm or more, 25 kV / mm or more or 30 kV / mm or more The breakdown voltage is not particularly limited as the value shows higher insulation. The dielectric breakdown voltage of the insulating 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 60 kV / mm or less. In consideration of insulation and thermal conductivity, it can be set in an appropriate range. Cotton, at least about 5 μm, at least about 10 μm, at least 20 μm, at least 30 μm, at least 40 μm, at least 50 μm, at least 60 μm, at least 70 μm, at least 80 μm, or at least 90 μm. The upper limit of the thickness is not particularly limited, and may 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.

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

Manufacturing method of the present application, the step of injecting the resin composition in the above-described module case; And storing the battery cell in the module case and curing the resin composition to form the resin layer.

The order of injecting the resin composition into the module case and storing the battery cells in the module case are not particularly limited. For example, the resin composition may be first injected into the module case, and the battery cell may be stored in that state, or the resin composition may be injected after the battery cell is first stored inside the module case.

As the resin composition, the resin composition described above can be used.

The method of injecting the resin composition into the module case is not particularly limited, and a known method may be applied. For example, the resin composition is poured into the opening of the module case to inject the resin composition, or the resin composition is injected through the above-described injection holes formed in the module case, the resin composition in both the battery cell and the battery module. The method of applying this may be applied. The implantation process may be performed while constantly vibrating the battery module or battery cell for proper fixation.

 The manner in which the battery cells are housed in the module case in which the resin composition is injected or in the module case before the composition is injected is not particularly limited.

The storage of the battery cells can be performed by arranging the battery cells at suitable positions in the module case in consideration of the desired arrangement and the like. In addition, when the cartridge structure is present, the above steps may be performed by positioning the battery cell at an appropriate position of the cartridge structure, or inserting the cartridge structure in which the battery cell is located in the module case.

After storing the battery cells, adhesion between the battery cells or adhesion between the battery cells and the module case may be formed by curing the injected resin composition. The manner of curing the resin composition is not particularly limited. In one example, when the composition is used, the resin composition may be cured by a method of maintaining the resin composition for a predetermined time (about 24 hours) at room temperature. At a level not to impair the thermal stability of the cell, heat may be applied for a certain time to promote curing. For example, prior to curing or prior to curing or storage of a battery cell, or the like, a temperature of less than 60 ° C., more specifically, a heat in the range of about 30 ° C. to 50 ° C., is applied to reduce tack time. And fairness can be improved. A cured product that can achieve adhesion between battery cells or adhesion between a battery cell and a module case may have a conversion rate of at least 80% or more as described above.

In another example of the present application, the present application relates to a battery pack, for example, a battery pack including two or more battery modules described above. In the battery pack, the battery modules may be electrically connected to each other. A method of configuring a battery pack by electrically connecting two or more battery modules is not particularly limited, and all known methods may be applied.

The present application also relates to a device including the battery module or the battery pack. Examples of the device include, but are not limited to, an automobile such as an electric vehicle, and may be any device for which a secondary battery is required as an output. In addition, the method of configuring the vehicle using the battery module or the battery pack is not particularly limited, and a general method known in the art may be applied.

According to an example of the present application, a resin composition which is excellent in injection processability into a battery module and which can prevent contamination of other components in the battery module after injection is provided. In addition, the composition has excellent insulation, heat dissipation, and adhesiveness after curing.

1 shows an example of determining the amorphous property or the sufficiently low crystallinity property of an ester polyol, according to an example of the present application.

2 illustrates an example module case that may be applied in the present application.

3 schematically illustrates a form in which a battery cell is accommodated in a module case.

4 schematically illustrates an example bottom plate in which injection holes and observation holes are formed.

5 and 6 schematically illustrate an example battery pouch that can be used as a battery cell.

7 and 8 schematically show the structure of an exemplary battery module.

Reference numerals associated with the drawings are as follows.

10: module case

10a: bottom plate

10b: sidewall

10c: top plate

10d: guiding part

20: battery cell

30: resin layer

50a: injection hole

50b: observation hall

40: insulation layer

100: pouch cell

110: electrode assembly

120: exterior material

121: upper shell

122: lower pouch

S: sealing part

Hereinafter, the battery module of the present application will be described with reference to Examples and Comparative Examples, but the scope of the present application is not limited by the scope given below.

Assessment Methods

1. Viscosity

The viscosity of the resin composition was measured under shear rate conditions from 0.01 to 10.0 / s at room temperature using a rheometer (ARES). The viscosity mentioned in the examples is the viscosity at the point of shear rate 2.5 / s, the TI (thixotropic index) can be determined through the ratio of the viscosity at the point of shear rate is 0.25 / s and 2.5 / s.

2. Insulation performance

Each of the breakdown voltage and the breakdown voltage described below was marked as O when the predetermined value was satisfied, and otherwise indicated by X.

(1) withstand voltage

It was measured according to ISO 6469-3. Specifically, the composition was injected in a module state, and after 1 hour, 2 kV was applied for 1 second, and if the leakage current was less than 1 mA, it was indicated as ○, and if it was above, it was indicated as X.

(2) Breakdown voltage

On the basis of ASTM D149, a cured product (cured hardening) having a thickness of 2 mm was prepared. When the dielectric breakdown voltage was measured, the value was expressed as ○ when the value of the dielectric breakdown voltage was 10 kV / mm or more, and the value indicated by the X was lower than this.

3. Fairness

As a module case having a shape as shown in FIG. 1, a module case having a lower plate, a side wall, and an upper plate made of aluminum was used. Guiding parts for guiding the mounting of the battery cells are formed on the inner side of the lower plate of the module case, and injection holes for injecting the resin composition are formed at regular intervals in the center of the upper plate and the lower plate of the module case. At the ends of the upper plate and the lower plate, a case having an observation hole was used. A bundle of pouches in which a plurality of battery pouches were stacked was stored in the module case. The top plate was then covered on the upper surface of the module case.

(1) The resin composition was injected into each of the injection holes of the upper plate and the lower plate, and it was confirmed that the composition reached the observation hole. If it takes less than 5 minutes to reach the observation hole, mark ○, and if it does not have enough flow to reach the observation hole, or because of too much flow, the upper direction of gravity in the module after injection In the case of not evenly filling each of the and the bottom is marked with X.

(2) Composition injection (filling) After 1 hour, the module was moved and vibrated while observing whether the composition flowed out of the module. In case there is no external contamination by the composition which flowed out, it was marked with (circle) and in case of contamination, it was marked with X.

Example  To Comparative example

Example  One

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

Isocyanate: A mixture of Hexamethylene diisocyanate (HDI) and an HDI trimer (having a viscosity of 170 cP as measured by a Brookfield LV type viscometer) was used for the isocyanate composition. At this time, the amount of isocyanate compound was adjusted so that the NCO index was about 100.

Filler: Alumina was used. The content was set to a ratio of 1,000 parts by weight to 100 parts by weight of the total content of the polyol and isocyanate, and the alumina was divided and blended in the same amount in the main composition part and the hardener composition part.

Dispersant: A predetermined amount of anionic dispersant was added.

Catalyst: Dibutyltin dilaurate (DBTDL: dibutyltin dilaurate) was used as the content shown in Table 1.

The components were mixed to prepare a two-component urethane composition.

Example  2

The composition was prepared in the same manner as in Example 1, except that the content of the dispersant was added to 70% of the content of the dispersant used in Example 1.

Example  3

The main composition portion includes polydimethylsiloxane (PDMS) having a vinyl group, and the curing agent composition portion is configured to include polydimethylsiloxane having a vinyl group and polydimethylsiloxane having a hydride group, and each has a viscosity of about 200,000 to 300,000. Blended with filler. The amount of the platinum catalyst used was properly adjusted during the mixing process.

Comparative example  One

The composition was prepared in the same manner as in Example 1, except that the content of the catalyst was used at 30% of the content used in Example 1.

Comparative example  2

The composition was prepared in the same manner as in Example 1, except that the content of the catalyst was used at a level three times that of the content used in Example 1.

Comparative example  3

The composition was prepared in the same manner as in Example 1, except that the repeating unit m in the general formula (2) of the main composition was less than 1.

TABLE 1

TABLE 2

From Tables 1 and 2 above, the embodiment satisfying the viscosity-related conditions of the present application implements excellent processability and insulation performance, it can be seen that the fairness is not good in the case of the comparative example that the viscosity conditions are not satisfied. Specifically, when V3 is too low due to insufficient curing as in Comparative Example 1, contamination to adjacent parts or peeling on the adhesive surface may occur, and when V2 is measured as in Comparative Example 2, curing is already performed. If too much, it can be seen that the injection fairness is not good. In the case where the viscosity related to V1 is too low, as in Comparative Example 3, excessive flow occurs before the curing progress after the injection, and thus the injected composition flows from the top of the gravity direction in the module to the bottom to be cured evenly. Rather than forming a resin layer, only the lower portion of the gravity direction is filled, and as a result, the upper portion of the gravity direction may be unfilled.

Claims (16)

The initial viscosity change rate defined by the following relational formula 1 is in the range of 1.1 to 5.0, The initial viscosity change rate defined by the following relational formula 2 is 10 or more, In the following relations 1 and 2, V ₁ is in the range of 100,000 to 500,000 cP, V ₂ is 2,000,000 cP or less, and V ₃ satisfies 5,000,000 cP or more: [Relationship 1] Initial Viscosity Change Rate = V ₂ / V ₁ [Relationship 2] Initial Viscosity Change Rate = V ₃ / V ₁ (In the above relations 1 and 2, V ₁ is the initial viscosity, the viscosity value measured at room temperature within 60 seconds after mixing the main composition and the curing agent components of the resin composition, V ₂ is a resin composition measured V ₁ at room temperature Viscosity measured after leaving for 5 minutes, V ₃ is the viscosity measured after leaving the resin composition V ₁ measured at room temperature for 60 minutes, V ₁ To V ₃ is a viscosity value measured at 2.5 / s when measured in a shear rate range of 0.01 to 10.0 / s using an Rheometer (ARES).) The resin composition according to claim 1, wherein the resin composition is a room temperature curing type, and the composition comprises a two-component silicone resin composition, a two-component urethane resin composition, a two-component epoxy resin composition, or a two-component acrylic resin composition. The resin composition of Claim 2 whose dielectric breakdown voltage of the hardened | cured material measured after 24 hours after mixing a main body and a hardening | curing agent is 10 kV / mm or more. The method of claim 2, wherein the resin composition is a two-component urethane-based composition, The two-component urethane composition may include an ester-based polyol resin-containing main composition portion; Polyisocyanate containing hardening | curing agent composition part; And fillers, The ester-based polyol is an amorphous polyol in which crystallization temperature (Tc) and melting temperature (Tm) are not observed in DSC (Differential Scanning calorimetry) analysis, or a resin composition having a melting temperature (Tm) of less than 15 ° C. The resin composition according to claim 4, wherein the resin component has a glass transition temperature (Tg) of less than 0 ° C. after curing. The resin composition of claim 4, wherein each of the ester-based polyol resin and the polyisocyanate has a viscosity of less than 10,000 cP. The resin composition of claim 4, wherein the ester polyol is represented by the following Chemical Formula 1 or 2: [Formula 1]

[Formula 2]

However, in said Formula (1) and (2), X is a carboxylic acid derived unit, Y is a polyol derived unit, n is a number in the range of 2-10, m is a number in the range of 1-10. The carboxylic acid-derived unit X is a 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, glataric acid unit, malonic acid unit, pimelic acid unit, suberic acid unit, 2, 2-dimethylsuccinic acid unit, 3,3-dimethylglutaric acid A resin composition which is at least one unit selected from the group consisting of units, 2,2-dimethylglutaric acid units, maleic acid units, fumaric acid units, itaconic acid units, and fatty acid units. 8. The polyol-derived unit Y according to claim 7, wherein the polyol-derived unit Y is an ethylene glycol unit, a propylene glycol unit, a 1,2-butylene glycol unit, a 2,3-butylene glycol unit, a 1,3-propanediol unit, 1,3 -Butanediol unit, 1,4-butanediol unit, 1,6-hexanediol unit, neopentylglycol unit, 1,2-ethylhexyldiol unit, 1,5-pentanediol unit, 1,9-nonanediol unit, 1 A resin composition which is one or two or more units selected from the group consisting of 10-decanediol units, 1,3-cyclohexanedimethanol units, 1,4-cyclohexanedimethanol units, glycerin units, and trimethylolpropane units . The two-component urethane composition according to claim 4, wherein the polyisocyanate is a non-aromatic polyisocyanate. The resin composition according to claim 10, wherein the non-aromatic polyisocyanate is an alicyclic polyisocyanate, a carbodiimide modified polyisocyanate of an alicyclic polyisocyanate, or an isocyanurate modified polyisocyanate of an alicyclic polyisocyanate. The resin composition of claim 4, wherein the filler comprises alumina, aluminum nitride (AlN), boron nitride (BN), silicon nitride, SiC, or BeO. The resin composition according to claim 4, comprising 50 to 2,000 parts by weight of a filler, based on 100 parts by weight of the total content of the ester-based polyol resin and the polyisocyanate. A module case having an upper plate, a lower plate, and sidewalls, and an inner space formed by the upper plate, lower plate, and sidewalls; A plurality of battery cells existing in an inner space of the module case; And The battery module of claim 1, wherein the composition according to claim 1 is cured and comprises a resin layer in contact with the plurality of battery cells. A battery pack comprising at least one other battery module according to claim 14. An automobile comprising the battery module according to claim 14 or the battery pack according to claim 15.

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