KR20190127135A - Method For Battery Module - Google Patents

Abstract

An application of the present invention relates to a method for manufacturing a battery module which can prevent a resin composition from protruding from the outside of a battery module to be cured when the resin composition is cured. The application of the present invention also relates to a battery module which can prevent a resin composition from protruding from the outside of the battery module through an injection hole by the residual pressure in the battery module to be cured, a battery pack including the battery module, and a vehicle including the battery module or the battery pack.

Description

Manufacturing Method of Battery Module {Method For Battery Module}

The present application relates to a method of manufacturing a battery module.

Secondary batteries include nickel cadmium batteries, nickel hydride batteries, nickel zinc batteries or lithium secondary batteries. Typical examples are lithium secondary batteries, and lithium secondary batteries mainly use lithium oxide and carbon materials as positive electrode active materials and negative electrode active materials, respectively.

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

Recently, secondary batteries are 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 secondary batteries are used in such medium and large devices, a large number of secondary batteries are electrically connected to increase capacity and output power. Pouch type secondary batteries are widely used in such medium and large devices due to their advantages such as low weight, low manufacturing cost, and easy deformation.

However, pouch-type secondary batteries generally do not have large mechanical stiffness, and the cells themselves do not include a structure for forming a bond between the batteries, and thus are difficult to stack. Therefore, when constructing a battery module including a plurality of pouch-type secondary batteries, a coupling member such as a separate cartridge for protecting the secondary battery stack from external shocks, preventing its movement, and facilitating stacking. Configuration is required.

Conventional methods for fixing a plurality of secondary batteries to the internal space of the battery module include a method of applying an overlap design of a secondary battery body portion, a method of applying surface pressure to a large area of the body portion, or an electrode terminal of a secondary battery. The busbar was fixed by laser welding. However, according to this conventional method, when external vibration is applied, not only the body portion of the secondary battery is shaken, but also mechanical shock is transmitted from the electrode assembly to the electrode tab and the electrode lead connected thereto, thereby affecting the electrical connection state. Mitch had a problem.

Korean Laid-Open Patent Publication No. 2016-0105354

In order to solve the above-mentioned problem, a method was used in which the resin composition was injected into the battery module and then cured to minimize the influence of external vibration. For example, in Patent Document 1, the above-described method is known, and in the method of Patent Document 1, a method of forming a module that is more compact and has excellent volume-to-volume output by forming a heat transfer path in a battery module using a resin composition is disclosed. Is disclosed.

However, in the above method, when the resin composition injected into the battery module is cured, it is protruded out of the battery module by the residual pressure in the battery module and cured, and the protruding portion makes post-processing difficult, and in other battery module performances or appearances. Since a problem occurred, there was a problem in that the protruding part was further removed.

One object of the present application is to provide a method of manufacturing a battery module that can prevent the resin composition from protruding out of the battery module through the injection hole by the residual pressure in the battery module and curing when the resin composition is cured.

Another object of the present application is a battery module capable of preventing the resin composition from protruding out of the battery module through the injection hole by the residual pressure in the battery module and hardening; A battery pack including the battery module; And it provides a vehicle comprising the battery module or the battery pack.

Hereinafter, embodiments of the present application will be described in detail with reference to the accompanying drawings.

On the other hand, the size and shape of each component member configured for convenience of description may be exaggerated or reduced.

The method of manufacturing a battery module of the present application includes a resin composition injection step of injecting a resin composition into a battery module case through an injection hole formed in a lower plate or sidewall of a battery module case in which a plurality of battery cells are accommodated; And an injection hole closing step of applying a curable material to the injection hole and curing the injection hole.

1 is a cross-sectional view showing an exemplary resin composition injection step of the present application. The injector 40 may inject the resin composition 30 into the battery module case through the injection hole 20 formed in the lower plate 10a of the battery module case in which the plurality of battery cells 50 are accommodated.

In the present application, the injector 40 for injecting the resin composition 30 into the battery module case is not particularly limited, and a known injector may be used as long as it can inject the resin composition 30. For example, the injector 30 may be an injector including a cartridge accommodating one or more resin compositions, a mixer for mixing the resin composition, a nozzle for discharging the mixture of the resin composition, and a driving unit for controlling movement of the resin composition. have.

In the present application, the resin composition 30 may be an adhesive material, and may also be a solvent type, an aqueous type, or a solventless type. In addition, the resin composition may be active energy curing type, moisture curing type, heat curing type or room temperature curing type.

In one embodiment, the resin composition 30 may be a two-component resin composition comprising a main body and a curing agent. The main material may be silicone resin, polyol resin, epoxy resin or acrylic resin. On the other hand, a known curing agent suitable for the subject may be used as the curing agent. For example, when the main material is a silicone resin, the curing agent may use a siloxane compound. When the main material is a polyol resin, the curing agent may use an isocyanate compound. When the main material is an epoxy resin, the curing agent may use an amine compound. In the case of, an isocyanate compound can be used as the curing agent.

In one example, the resin composition may be a two-component urethane-based composition. The two-component urethane-based composition may include a hardener including at least a main body containing a polyol resin and at least an isocyanate. 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.

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

On the other hand, the ester polyol may be amorphous or a polyol sufficiently low in crystallinity. The term "amorphous" as used herein is known to those skilled in the art. For example, "amorphous" means a case where no crystallization temperature Tc and a melting temperature Tm are observed in differential scanning calorimetry (DSC) analysis described later. At this time, the DSC analysis can be carried out in the range of -80 to 60 ℃ at a rate of 10 ℃ / min, for example, after increasing the temperature from 25 ℃ to 60 ℃ at the above speed to -80 ℃, It can be made in such a way that the temperature is raised to 60 ℃ again. In addition, the above-mentioned "low enough 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 the case below about ℃ or about -20 ℃. At this time, the lower limit of the melting point is not particularly limited, for example, the melting point may be about -80 ℃ or more, -75 ℃ or more or about -70 ℃ or more. In the case where the polyol is crystalline or has a strong (at 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 This may adversely affect the process, lowers the processability, and as a result, it may become difficult to satisfy the cold resistance, heat resistance and water resistance required in the two-component resin composition for the battery module.

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

The carboxylic acid polyol may be formed by reacting a component including a carboxylic acid and a polyol (ex. Diol or triol, etc.), and the caprolactone polyol includes a caprolactone and a polyol (ex. Diol or triol). It can form by making the component to react. In this case, the carboxylic acid may be 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. In addition, n and m may be any number, for example n is a number in the range of 2 to 10, m is a number in the range of 1 to 10, R ₁ and R ₂ are each independently 1 to 14 carbon atoms Alkylene in 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, the term "polyol derived unit" as used herein may mean a portion excluding a hydroxy group in the polyol compound structure.

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

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. That is, in Formula 2, the polyol-derived unit, Y, may mean a portion of the polyol structure that does not participate in the ester bond when the polyol and caprolactone form an ester bond. Ester bonds are shown in formulas (1) and (2), respectively.

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 Chemical Formula 1, the kind 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 one or more compounds selected from the group consisting of aliphatic compounds having two or more 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 tetrachlorophthalic acid.

The aliphatic compound having two or more carboxyl groups may be, 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.

In view of the low glass transition temperature in the following range, an aliphatic carboxylic acid derived unit may be preferable to an aromatic carboxylic acid derived unit.

On the other hand, although 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, in the group consisting of alicyclic compounds having two or more hydroxy groups and aliphatic compounds having two or more hydroxy groups It may be derived from one or more compounds selected.

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, neopentylglycol, 1,2-ethylhexyldiol, 1,5-pentanediol, 1,9-nonanediol, 1,10-decanediol, glycerin or trimethylol It may be propane.

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.

In Formula 2 R ₁ and R ₂ is an alkylene group having a carbon number in the range of 1 to 14 independently of each other. The carbon number may be selected in consideration of the desired physical properties of the resin composition or the cured resin layer thereof.

The molecular weight of the polyol may be adjusted in consideration of viscosity, durability or adhesion, for example, it 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 kind of isocyanate included in the curing agent is not particularly limited, but a non-aromatic isocyanate compound containing no aromatic group may be used to secure desired physical properties. 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 resin composition.

As a non-aromatic isocyanate compound, For example, aliphatic polyisocyanate, such as hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate, norbornane diisocyanate methyl, ethylene diisocyanate, propylene diisocyanate, or tetramethylene diisocyanate, etc. ; Alicyclic 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.

On the other hand, the resin component contained in the two-component resin composition may have a glass transition temperature (Tg) of less than 0 ℃ after 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 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.

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

On the other hand, the resin composition may comprise a filler. The filler 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, 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, but may be an inorganic 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 shape and proportion of the fillers are not particularly limited, and the viscosity of the resin composition, the possibility of sedimentation in the cured resin layer, the desired thermal resistance or thermal conductivity, insulation, filling effect, dispersibility or storage stability, etc. Can be adjusted appropriately. 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 described later. 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.

In one example, the resin composition 30 may include a thermally conductive filler having an average particle diameter in the range of about 0.001 μm to 80 μm. In another example, the average particle diameter of the filler may be about 0.01 μm, 0.1 μm, 0.5 μm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, or about 6 μm or more. In another example, the average particle diameter of the filler is about 75 μm or less, 70 μm or less, 65 μm or less, 60 μm or less, 55 μm or less, 50 μm or less, 45 μm or less, 40 μm or less, 35 μm or less, 30 μm or less, 25 μm or less, 20 μm or less, 15 μm or less, 10 μm or less, or about 5 μm or less.

In order to obtain excellent heat dissipation performance, it may be considered that a high content of thermally conductive filler is used. The filler may be used in the range of about 200 to about 2,000 parts by weight, relative to 100 parts by weight of the total resin component of the resin composition, for example, the total content of the polyol resin and the polyisocyanate. Specifically, the filler content may be about 250 parts by weight, 300 parts by weight, 350 parts by weight or about 400 parts by weight or more of fillers based on 100 parts by weight of the total resin component, and 100 parts by weight of the total resin component. And about 2,000 parts by weight or less, 1,800 parts by weight or less, or about 1,6000 parts by weight or less. Within the ratio range of the said filler, desired physical properties, such as thermal conductivity and insulation, can be ensured.

In one example, the moisture content of the filler may be about 1,000 ppm or less. The moisture content can be measured by a Karl fishcer titrator KR831 under conditions of 10% relative humidity and drift 5.0 or less. In this case, the moisture moisture content may be an average moisture content of the total filler used in the resin composition. In the present application, a filler that satisfies the above conditions may be selectively used, or after the filler to be dried 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 filler moisture content may be about 800 ppm or less, 600 ppm or less, or about 400 ppm or less, and the lower limit may be about 100 ppm or more or about 200 ppm or more.

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 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.

2 is a cross-sectional view showing the step of applying the exemplary curable material of the present application to the injection hole. The curable material 60 may be applied to the injection hole 20 formed in the lower plate 10a.

Application of a curable material can use a well-known applicator. The applicator 70 may apply a curable material onto the resin composition 30a of the injection hole 20.

The curable material 60 may include a resin and an initiator.

The resin is not particularly limited as long as it is a curable resin, and may be a known curable resin. For example, the resin may be a photocurable resin. The photocurable resin may include polyester acrylate, epoxy acrylate, urethane acrylate, polyether acrylate or silicone acrylate.

The term photocurable in the present application means a type that is cured by irradiation of light, and in the above category of light, microwaves, infrared rays (hereinafter referred to as IR), ultraviolet rays (hereinafter referred to as UV), X-rays and gamma rays, as well as And particle beams such as alpha-particle beams, proton beams, neutron beams or electron beams.

Curable material 60 may comprise an initiator, which may be a photoinitiator. The photoinitiator may include at least one selected from the group consisting of acetophenone-based, benzoin-based, benzophenone-based, thioxanthone-based, iodonium-based, and sulfonium-based.

3 is a cross-sectional view illustrating an exemplary injection hole closing step of the present application. The light irradiator 80 irradiates light toward the curable material (60 in FIG. 2) applied to the injection hole 20 to cure the curable material (60 in FIG. 2) to form a curing member (or a sealing member) ( The injection hole can be closed by forming 60a).

The light irradiator 80 is not particularly limited, and a known light irradiator capable of irradiating light may be used. The light is not particularly limited as long as it can be irradiated by a light irradiator such as infrared rays, visible rays or ultraviolet rays, for example, UV may be used.

The light irradiation may be cured by irradiating the curable material 60 with light for about 5 to 15 seconds. In one embodiment the light irradiation may be irradiated for at least about 5 seconds, 6 seconds, 7 seconds or about 8 seconds, or about 15 seconds, 14 seconds 13 seconds or less than about 12 seconds.

When the curable material (60 in Fig. 2) is cured by light irradiation such as UV irradiation, a hardening member 60a is formed, and the injection hole 20 is closed by the hardening member 60a to harden the resin. The composition 30a may be prevented from protruding out of the battery module through the injection hole by the residual pressure in the battery module and hardening. Therefore, an additional process for removing the hardened portion protruding out of the battery module is not required, thereby reducing the manufacturing cost and manufacturing time of the battery module.

The battery module manufacturing method of the present application may further include a sheet attaching step of attaching the adhesive sheet to the injection hole formed in the lower plate or the sidewall before the resin composition injection step, wherein the resin composition in the resin composition injection step comprises the adhesive sheet It may be penetrated and injected into the battery module case.

4 is a cross-sectional view showing the step of attaching the exemplary adhesive sheet 90 of the present application. The adhesive sheet 90 may be attached to the injection hole 20 formed in the lower plate 10a of the battery module case.

The adhesive sheet 90 may include a substrate and an adhesive layer formed on the substrate. The substrate may be selected from materials having high tensile strength in the form of a polymer film having flexibility and durability. For example, the substrate may be a polyolefin such as polyethylene or polypropylene, polyester such as polyethylene terephthalate or polybutylene terephthalate, polyvinyl chloride, polystyrene, polyurethane, polycarbonate, polyamide, polyimide, poly (meth) One or more selected from the group consisting of acrylic acid, polybutene and polybutadiene, but is not limited thereto.

The adhesive layer formed on the substrate may include a material having adhesiveness such that the substrate is adhered to the battery module case. For example, the adhesive layer may be formed by applying an adhesive including acrylic, polyester, polyurethane, rubber, silicone, or epoxy onto a substrate, or an adhesive film formed from the adhesive may be attached onto the substrate.

The adhesive sheet 90 may be attached to the injection hole 20. Meaning of being attached to the injection hole 20 may be attached in a form covering the injection hole 20 beyond the size of the injection hole 20. In addition, when one or more injection holes 20 are provided, an individual adhesive sheet 90 corresponding to each injection hole 20 may be attached and one adhesive sheet 90 covering all of the one or more injection holes 20. ) Can be attached. That is, in one embodiment, when the plurality of injection holes 20 are formed to be arranged in an arbitrary direction, one adhesive sheet 90 may be extended and attached along the arrangement direction of the injection holes 20.

In the resin composition injection step, the resin composition 30 may be injected into the battery module case through the adhesive sheet 90.

Injection into the battery module case through the adhesive sheet 90 means that the adhesive sheet 90 attached to the injection hole 20 formed in the lower plate 10a or the side wall 10b of the battery module case is opened before injection. Alternatively, it can be injected by opening simultaneously with the injection.

Opening the adhesive sheet 90 before the injection may be performed after opening the portion of the adhesive sheet 90 corresponding to the injection hole 20 before attaching the adhesive sheet 90 to the injection hole 20. Alternatively, the adhesive sheet 90 may be opened by puncturing a portion corresponding to the injection hole 20 after attaching the adhesive sheet 90 to the injection hole 20. In addition, the method of opening the adhesive sheet 90 is not specifically limited, It can open by a well-known method.

Opening the adhesive sheet 90 at the same time as the injection means that the injector (40 in FIG. 1) for injecting the resin composition 30 is positioned in the injection hole 20 for injecting the resin composition 30. The injector 40 may open the adhesive sheet by applying a predetermined pressure to the adhesive sheet 90 attached to the injection hole 20. At this time, one end surface (not shown) of the injector 40 may be sharply formed to facilitate the opening of the adhesive sheet 90.

On the other hand, if the injector 40 can be easily injected into the injection hole 20 through the adhesive sheet 90, the size and shape of the opening of the adhesive sheet 90 is not particularly limited. For example, the size of the opening of the adhesive sheet 90 may be equal to or smaller than the size of the injection hole. If the adhesive sheet 90 is the same as or smaller than the size of the injection hole, it is possible to prevent the battery module from being contaminated even if the resin composition is back discharged.

 The battery module manufacturing method of the present application may further include a sheet peeling step of peeling the adhesive sheet attached to the injection hole before the injection hole closing step.

5 is a cross-sectional view showing a step of peeling an exemplary adhesive sheet of the present application. That is, the adhesive sheet 90 attached to the injection hole 20 of the lower plate 10a may be peeled off from the lower plate.

The method of peeling off an adhesive sheet is not specifically limited. It can be peeled off manually by a person and can be peeled off automatically by a machine.

On the other hand, peeling of an adhesive sheet can peel after about 1 hour-about 4 hours after resin composition is inject | poured into a battery module case. That is, after hardening of the said resin composition advances more than a predetermined time, an adhesive sheet is peeled off. The peeling time may be controlled by the type of resin composition. That is, when the curing of the resin composition proceeds quickly, the peeling of the adhesive sheet may be accelerated. When the curing of the resin composition proceeds slowly, the peeling of the adhesive sheet may be delayed. When the resin composition peels off the adhesive sheet before curing sufficiently, the uncured resin composition may be stained on the adhesive sheet, and the battery module may be contaminated. When the resin composition is cured, the adhesive composition is adhered to the adhesive sheet. It may not be easy to peel off.

The present application also relates to a battery module. 6 is a cross-sectional view illustrating an exemplary battery module of the present application. The battery module has a bottom plate 10a and sidewalls 10b, and an inner space is formed by the bottom plate 10a and sidewalls 10b, and an injection of a resin composition formed on the bottom plate 10a or sidewalls 10b. A module case having a hole 20; A plurality of battery cells 50 present in an inner space of the module case; A resin layer (30b) formed by curing the resin composition and in contact with at least one of the plurality of battery cells, the bottom plate, or the sidewalls; And a sealing member (60a) for sealing the injection hole of the resin composition.

The battery module case may have a box shape including one lower plate 10a and four sidewalls 10b. The battery module case forms an inner space by a lower plate 10a and four sidewalls 10b. The battery module case may further include a top plate (not shown) for sealing the internal space. The terms "top plate" and "bottom plate" may be used interchangeably along the reference direction.

The battery module case may be formed by an integrated lower plate 10a and sidewalls 10b, or may be formed by assembling separate lower plate 10a, sidewalls 10b and / or top plates (not shown). The shape and size of the module case is not particularly limited and may be appropriately selected according to the use of the module case and the shape and number of battery cells accommodated in the internal space.

The battery module case may be a thermally conductive case. The term thermally conductive case means a case having a thermally conductive region in which the thermal conductivity of the entire case is 10 W / mk or more or at least has the above-described thermal conductivity. For example, at least one of the above-described side wall 10b, the bottom plate 10a, and the top plate (not shown) may have the thermally conductive region. In another example, the lower plate 10a and the sidewall 10b may include the thermally conductive region at a portion in contact with a resin layer described later formed by the injected resin composition. In the above, the thermal conductivity is, 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 At least 90 W / mk, at least 100 W / mk, at least 110 W / mk, at least 120 W / mk, at least 130 W / mk, at least 140 W / mk, 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 about 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 less than or equal to 300 W / mk or about 250 W / mK. The kind of the material which exhibits the above thermal conductivity is not particularly limited, and examples thereof include iron, aluminum, gold, silver, tungsten, copper, nickel, platinum or a metal material of an alloy containing them.

In addition, the thermally conductive region may be a portion in contact with a cooling medium such as cooling water. According to this structure, a structure capable of effectively dissipating heat generated from the battery cell to the outside may be implemented.

On the other hand, when the measurement temperature affects the physical properties among the physical properties mentioned in the present specification, unless otherwise stated, the physical properties may be physical properties measured at room temperature. As used herein, the term room temperature may refer to any temperature within a range of about 10 ° C. to 30 ° C., for example, about 25 ° C., 23 ° C., or about 20 ° C.

The lower plate 10a, the side wall 10b, and / or the upper plate (not shown below) of the battery module case may have an injection hole 20 (or a through hole). At this time, the shape, number and position of the injection hole 20 can be adjusted in consideration of the injection efficiency of the resin composition.

The injection hole 20 may be formed in the side wall 10b, the lower plate 10a, or the upper plate (not shown). The position (Q) of the injection hole may be formed at about 1/4 to 3/4 points or about 3/8 to 7/8 points or about an intermediate portion of the entire length of the lower plate or the like. By injecting the resin composition through the injection hole 20 formed at the point, the injection time of the resin composition can be shortened, and the resin composition can be evenly injected into the battery module. In a specific embodiment, the resin composition injected through the injection hole 20 moves along the injection (or movement) direction of the resin composition.

The 1/4, 3/4, 3/8 or 7/8 point is formed of the injection hole 20 relative to the total length L of the lower plate or the like measured based on any one end surface of the lower plate or the like. It is the ratio of the distance A to the position. In addition, the terminal in which the length L and the distance A are formed in the above may be any terminal as long as the length L and the distance A are measured from the same end.

In the present application, the term battery cell 50 refers to one unit secondary battery including an electrode assembly and an exterior member.

The type of battery cell 50 accommodated in the battery module case is not particularly limited, and various known battery cells may be applied. In one example, the battery cell 50 may be a pouch type.

On the other hand, the resin layer 30b may be a resin layer 30b formed by curing the above-described resin composition 30. The resin layer 30b 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, 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. . The thermal conductivity 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, 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 a resin layer is a numerical value measured according to ASTMD5470 standard or ISO 22007-2 standard, for example. 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.

The sealing member 60a is not particularly limited as long as it can seal the injection hole 20. The sealing member may be formed or coupled. The term forming form in the present application means all formed on the cured resin composition 30a of the injection hole to seal the injection hole. For example, the forming sealing member may seal the injection hole 20 by applying and curing the aforementioned curable material 60 to the injection hole.

On the other hand, in the present application, the term coupled type means other than the formed type, and may mean, for example, a sealing member manufactured by star. In one embodiment, the injection hole may be sealed by fastening a separately manufactured sealing member to the injection hole.

The present application also 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. The method of configuring the 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 such devices include, but are not limited to, automobiles such as electric vehicles, and may include all applications requiring a secondary battery as an output. For example, a method of configuring the vehicle using the battery module or the battery pack is not particularly limited, and a general method may be applied.

The method of manufacturing the battery module of the present application may prevent the resin composition from protruding out of the battery module through the injection hole by the residual pressure in the battery module and curing when the resin composition is cured. In addition, the manufacturing method of the battery module of the present application may reduce the production cost of the battery module and shorten the production time since an additional process for removing the hardened portion protruding out of the battery module is unnecessary. In addition, even if the residual pressure in the battery module is high, the resin composition may be prevented from protruding out of the battery module and cured. It is possible.

1 is a cross-sectional view showing an exemplary resin composition injection step of the present application.
2 is a cross-sectional view illustrating the steps of applying an exemplary curable material of the present application.
3 is a cross-sectional view illustrating an exemplary injection hole closing step of the present application.
4 is a cross-sectional view showing the step of attaching an exemplary adhesive sheet of the present application.
5 is a cross-sectional view showing a step of peeling an exemplary adhesive sheet of the present application.
6 is a cross-sectional view illustrating an exemplary battery module of the present application.
7 is a schematic view showing a manufacturing method of an exemplary battery module of the present application.

7 is a schematic view showing a manufacturing method of an exemplary battery module of the present application. Hereinafter, examples and comparative examples will be described with reference to FIG. 7, but the scope of the present application is not limited by the ranges set forth below.

Assessment Methods

One. Reverse discharge

The resin composition was injected through the injection holes formed in the lower plate of the battery module case in which the plurality of battery cells were accommodated. Injecting the resin composition was placed through the injection hole formed in the lower plate after the lower plate is positioned upward.

Whether the injected resin composition is discharged upward through the injection hole by the residual pressure in the battery module during curing, or through the injection hole formed in the lower plate due to the weight of the battery cell when the battery module is turned upside down immediately after injection. It was evaluated whether or not this was back discharged.

<Evaluation result>

○: reverse discharge

X: If not discharged back

2. Fairness

Even when the back discharge of the resin composition is prevented, two steps of attaching and removing the adhesive sheet to the injection hole are required for the above prevention, a process of manually closing the injection hole, or an additional process such as heat treatment is required. When it is required that it is not suitable for an automated process or an excessively long manufacturing time is illustrated, it is evaluated that fairness suitable for an automated process is not secured.

<Evaluation result>

○: suitable for automated process applications

X: Not suitable for automated process application

Example  To Comparative example

Example

The battery module was manufactured through the following steps S1 to S6.

Step S1: The adhesive sheet is attached to the injection hole formed in the lower plate of the battery module case containing a plurality of battery cells.

Step S2: The two-component urethane resin composition is cured with alumina (particle size distribution: 1 µm to 60 µm) in a two-component urethane resin composition (topic: HP-3753 (KPX Chemical), a curing agent: TLA-100 (made by Asaika)). Later, it is mixed in an amount capable of exhibiting a thermal conductivity of about 3 W / mK (within the range of about 600 to 900 parts by weight relative to 100 parts by weight of the total amount of lyotropic liquid), using a rheometer (ARES) at room temperature, 0.01 to 10.0 / When measured in a shear rate range up to s, a resin composition having a viscosity of about 250,000 cP measured at a point of 2.5 / s was prepared, and injected through the injection hole.

Step S3: The resin composition injected into the battery module was cured for 80 minutes.

Step S4: After 80 minutes curing, the adhesive sheet attached to the injection hole was removed.

S5 step: photocurable polyurethane resin and photoinitiator (TPO (Diphenyl (2,4,6-trimethylbenzoyl) -phosphine oxide)) having a weight average molecular weight (Mw) of 500 or more as a curable resin on the injection hole where the adhesive sheet is peeled off The curable material containing the was applied.

S6 step: UV (UV) was irradiated to the site to which the curable material was applied for 10 seconds.

Comparative example  One

Among the steps S1 to S6 of the embodiment, the battery module was manufactured only by the steps S2 and S3.

Comparative example  2

After the steps S1 to S4 of the embodiment, the adhesive sheet having no opening was attached to the injection hole and the adhesive sheet was removed after curing the resin composition.

Comparative example  3

After the steps S1 to S4 of the embodiment, the injection hole was sealed using a stopper.

Comparative example  4

After the steps S1 to S4 of the embodiment, the injection hole portion was heated to a temperature of 50 ℃ or less.

fair Reverse discharge Fairness Example UV irradiation X ○ Comparative Example 1 none ○ X Comparative Example 2 Attach the adhesive sheet to the injection hole
Removing after curing resin composition X X
(2 steps required) Comparative Example 3 Seal the injection hole with a stopper X X
(Automation process difficulty) Comparative Example 4 Heating the injection hole ○ X
(Long time to harden)

From the above Table 1, the battery module of the embodiment manufactured by the method of manufacturing the battery module of the present application applied a curable material to the injection hole after removing the adhesive sheet and irradiated with UV to prevent the resin composition from being reversed and cured. Therefore, no additional process for removing the resin composition that protrudes and cures is not necessary, and the curable material is cured in a short time, thereby shortening the manufacturing time per battery module, thereby making it suitable for an automated process application.

On the other hand, Comparative Example 1 has a resin composition is back discharged, Comparative Examples 2 and 3 are not discharged because the resin composition is back discharged, but in order to prevent this, Comparative Example 2 attaches an adhesive sheet to the injection hole and cures the resin composition. After removing the adhesive sheet, the adhesive sheet is removed after attaching the adhesive sheet, which requires two times in the manufacturing process of the battery module, resulting in poor processability. In Comparative Example 3, the injection hole must be manually sealed using a stopper. The battery cells can be pressurized, making them unsuitable for automated process applications. On the other hand, in Comparative Example 4, the viscosity of the resin composition was lowered by heating, and when the upside and downside of the battery module was inverted immediately after injecting the resin composition, the discharge of the resin composition was better, and the resin composition was sufficiently cured to support the weight of the battery cell. It takes a long time to manufacture, which makes manufacturing time per battery module too long, making it unsuitable for the automated process application of battery modules.

10a: bottom plate
10b: sidewall
20: injection hole
30: resin composition
30a: resin composition to be cured
30b: resin layer
40: injector
50: battery cell
60: curable material
60a: hardening member, sealing member
70: curable material applicator
80: light irradiator
90: adhesive sheet

Claims (15)

A resin composition injection step of injecting the resin composition into the battery module case through an injection hole formed in a lower plate or sidewall of a battery module case in which a plurality of battery cells are accommodated; And
The battery module manufacturing method comprising the injection hole closing step of applying a curable material to the injection hole to cure. The method of claim 1, wherein the resin composition is a two-component composition comprising a main agent and a curing agent. The method of claim 2, wherein the resin composition further comprises an inorganic filler. The method of claim 1, wherein the curable material applied to the injection hole is photocurable. The method of claim 4, wherein the curable material comprises a resin and an initiator. The method of claim 5, wherein the initiator is at least one selected from the group consisting of acetophenone-based, benzoin-based, benzophenone-based, thioxanthone-based, iodonium-based, and sulfonium-based. The method of claim 1, wherein the curing of the curable material is performed by irradiating light for 5 to 15 seconds. The battery module of claim 1, further comprising a sheet attaching step of attaching the adhesive sheet to the injection hole before the resin composition injecting step, wherein the resin composition is injected into the battery module case through the adhesive sheet. Manufacturing method. The method of claim 8, further comprising a sheet peeling step of peeling the adhesive sheet attached to the injection hole before the injection hole closing step. The method of claim 9, wherein the adhesive sheet has an opening at a position corresponding to the injection hole. A module case having a lower plate and sidewalls, an inner space formed by the lower plate and sidewalls, and an injection hole of a resin composition formed in the lower plate or sidewalls;
A plurality of battery cells existing in an inner space of the module case;
A resin layer formed by curing the resin composition and in contact with at least one of the plurality of battery cells, the bottom plate, or the sidewalls; And
Battery module including a sealing member for sealing the injection hole of the resin composition. The battery module according to claim 11, wherein the thermal conductivity of the resin layer is 3.0 W / mK or more. The battery module according to claim 11, wherein the sealing member is a cured product of a photocurable resin. A battery pack comprising two or more battery modules of claim 11 electrically connected to each other. An automobile comprising the battery module of claim 11 or the battery pack of claim 14.

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