Detailed description of the invention
Technical challenges
[8]
The present application can provide a battery module.
Task resolution
[9]
The battery module of the present application includes a module case and a battery cell. The battery cell may be housed in the module case. One or more battery cells may exist in the module case, and a plurality of battery cells may be accommodated in the module case. The number of battery cells accommodated in the module case is not particularly limited as it is adjusted according to the use or the like. The battery cells housed in the module case may be electrically connected to each other.
[10]
The module case may include at least a sidewall and a lower plate forming an inner space in which the battery cells can be accommodated. The module case may further include an upper plate sealing the inner space. The side wall, the lower plate and the upper plate may be integrally formed with each other, or the separate side walls, 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 is not particularly limited, and may be appropriately selected according to a purpose, the shape and number of battery cells accommodated in the internal space.
[11]
In the above, the terms upper plate and lower plate are terms of a relative concept used to distinguish them because there are at least two plates constituting the module case. That is, it does not mean that the top plate must exist at the top and the bottom plate must be at the bottom in actual use.
[12]
1 is a view showing an exemplary module case 10, and is an example of a box-shaped case 10 including one lower plate 10a and four side walls 10b. The module case 10 may further include an upper plate 10c sealing the inner space.
[13]
FIG. 2 is a schematic view of the module case 10 of FIG. 1 in which the battery cells 20 are housed, observed from the top.
[14]
Holes may be formed in the lower plate, sidewall and/or upper plate of the module case. These holes may be formed in an upper plate and a lower plate that are in contact with the resin layer, which will be described later. The hole may be an injection hole for injecting a material (resin composition) for forming the resin layer when the resin layer is formed by an injection process as described later. At this time, the shape, number, and position of the holes may be adjusted in consideration of the injection efficiency of the forming material of the resin layer. In one example, the hole may be formed on at least the lower plate and the upper plate.
[15]
In one example, the hole may be formed at about 1/4 to 3/4 point, about 3/8 to 7/8 point, or about the middle part of the total length of the side wall, the lower plate, or the upper plate. By injecting the resin composition through the injection hole formed at this point, the resin layer can be injected to have a wide contact surface. The point of 1/4, 3/4, 3/8 or 7/8 is the total length measured based on any one end surface (E) of the lower plate, for example, as shown in FIG. It is the ratio of the distance (A) to the formation position of the hole compared to L). In addition, the end (E) where the length (L) and the distance (A) are formed may be any end (E) as long as the length (L) and the distance (A) are measured from the same end (E). have. In FIG. 3, the injection hole 50a has a shape located at an approximately middle portion of the lower plate 10a.
[16]
The size and shape of the injection hole are not particularly limited, and may be formed in consideration of injection efficiency of the resin layer material described later. For example, the hole may be polygonal or amorphous, such as circular, elliptical, triangular or square. The number of injection holes and the spacing thereof are not greatly limited, and as described above, the resin layer may be adjusted to have a large contact area with the lower plate.
[17]
Observation holes (for example, 50b in FIG. 3) may be formed at ends of the upper plate and the lower plate in which the injection holes are formed. The observation hole may be for observing whether the injected material is well injected to the end of the side wall, the lower plate, or the upper plate, for example, when the resin layer material is injected through the injection hole. The position, shape, size, and number of the observation holes are not limited as long as they are formed to confirm whether the injected material is properly injected.
[18]
The module case may be a thermally conductive case. The term thermally conductive case refers to a case in which the thermal conductivity of the entire case is 10 W/mk or more, or at least a portion having the thermal conductivity as described above is included. For example, at least one of the above-described sidewall, lower plate, and upper plate may have the thermal conductivity described above. In another example, at least one of the sidewall, the lower plate, and the upper plate may include a portion having the thermal conductivity.
[19]
The structure of the battery module according to the exemplary embodiment of the present application includes a first filler-containing cured resin layer in contact with an upper plate and a battery cell, a lower plate, and a second filler-containing cured resin layer in contact with the battery cell, as described later. . In this structure, at least the second filler-containing cured resin layer may be a thermally conductive resin layer, and thus at least the lower plate may be thermally conductive or may include a thermally conductive portion.
[20]
In the above, the thermal conductivity of the thermally conductive upper plate, lower plate or sidewall or thermally conductive portion is 20 W/mk or more, 30 W/mk or more, 40 W/mk or more, 50 W/mk or more, 60 W/mk in other examples. More than 70 W/mk, more than 80 W/mk, more than 90 W/mk, more than 100 W/mk, more than 110 W/mk, more than 120 W/mk, more than 130 W/mk, more than 140 W/mk, It may be 150 W/mk or more, 160 W/mk or more, 170 W/mk or more, 180 W/mk or more, 190 W/mk or more, or 195 W/mk or more. The higher the thermal conductivity, the higher the value is, the more advantageous it is in terms of heat dissipation characteristics of the module, and thus 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 type of material exhibiting 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 the thermally conductive material as described above, or at least a portion of the module case may be made of the thermally conductive material. Accordingly, the module case may have a thermal conductivity in the above-mentioned range, or may include at least a portion having the above-mentioned thermal conductivity.
[21]
In the module case, the portion having the thermal conductivity in the above range may be a portion in contact with the resin layer and/or the insulating layer described later. In addition, the portion having the thermal conductivity may be a portion in contact with a cooling medium such as cooling water. According to this structure, a structure capable of effectively discharging heat generated from the battery cell to the outside can be implemented.
[22]
On the other hand, in the case where the measured temperature affects the physical properties among the physical properties mentioned in the present specification, the physical properties may be those measured at room temperature, unless otherwise stated. As used herein, the term room temperature may mean any temperature in the range of about 10°C to 30°C, for example, about 25°C, about 23°C, or about 20°C.
[23]
The type of battery cells accommodated in the module case is 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. 4, the pouch-type battery cell 100 may typically include an electrode assembly, an electrolyte, and a pouch case.
[24]
4 is an exploded perspective view schematically showing the configuration of an exemplary pouch-type cell, and FIG. 5 is a combined perspective view of the configuration of FIG. 4.
[25]
The electrode assembly 110 included in the pouch-shaped cell 100 may have a form in which at least one positive electrode plate and at least one negative electrode plate are disposed with a separator interposed therebetween. The electrode assembly 110 may be divided into a winding type in which one positive plate and one negative plate are wound together with a separator, or a stack type in which a plurality of positive plates and a plurality of negative plates are alternately stacked with a separator interposed therebetween.
[26]
The pouch exterior material 120 may be configured in a form including, for example, an outer insulating layer, a metal layer, and an inner adhesive layer. The exterior material 120 protects the electrode assembly 110 and internal elements such as an electrolyte, and may include a metal thin film such as aluminum in consideration of supplementation and heat dissipation properties of the electrochemical properties by the electrode assembly 110 and the electrolyte. I can. The metal thin film may be interposed between an insulating layer formed of an insulating material to secure electrical insulation with elements such as the electrode assembly 110 and an electrolyte or other elements outside the battery 100.
[27]
In one example, the exterior material 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 internal space (I). Can be formed. The electrode assembly 110 may be accommodated in the inner space I of the pouch. A sealing part S is provided on the outer circumferential surfaces of the upper pouch 121 and the lower pouch 122, and the sealing parts S are adhered to each other, so that the inner space in which the electrode assembly 110 is accommodated may be sealed.
[28]
Each electrode plate of the electrode assembly 110 is provided with 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 and exposed to the outside of the exterior material 120, thereby functioning as an electrode terminal of the secondary battery 100.
[29]
The shape of the pouch-type cell is an example, and the battery cell applied in the present application is not limited to the above type. In the present application, known various types of pouch-type cells or other types of batteries may all be applied as battery cells.
[30]
The battery module of the present application may further include a resin layer. Specifically, the battery module of the present application may include at least a filler-containing cured resin layer. In the present application, the term filler-containing cured resin layer is a layer including a resin component and a filler. The term cured resin layer refers to a layer formed by curing a resin composition having a low viscosity of a liquid or sufficient fluidity. In the above, a liquid state or a low viscosity having sufficient fluidity may mean about 400 cP or less or a range of 100 to 400 cP (at room temperature, based on a shear rate of 2.5/s). The viscosity is a result of measurement according to the method of Examples to be described later. The lower limit of the viscosity is not particularly limited as long as the resin composition has a sufficient low viscosity, but may generally be about 10 Pas or more. In addition, the said viscosity is the viscosity of the resin composition before hardening.
[31]
The battery module may include, as the filler-containing cured 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. have.
[32]
In one example, each of the resin layers may be an adhesive layer. The term adhesive layer means that the adhesive strength of the resin layer is 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 do. The adhesion is measured with respect to an aluminum pouch according to the method disclosed in Examples to be described later. The upper limit of the adhesive force of the resin layer is not particularly limited, for example, about 2,000 gf/10mm or less, 1,500 gf/10mm or less, 1,000 gf/10mm or less, 900 gf/10mm or less, 800 gf/10mm or less, 700 gf It may be about /10mm or less, 600 gf/10mm or less, or 500 gf/10mm or less.
[33]
By forming at least two filler-containing cured resin layers in the battery module as described above, a battery module having excellent durability against external shock or vibration may be provided.
[34]
In the battery module of the present application, at least one of the sidewall, the lower plate, and the upper plate in contact with the resin layer may be the thermally conductive sidewall, the lower plate, or the upper plate. Meanwhile, in the present specification, the term contact means, for example, the resin layer and the upper plate, the lower plate and/or the sidewall or the battery cell are in direct contact, or other elements such as an insulating layer are present therebetween. It can also mean a case. Further, the resin layer in contact with the thermally conductive sidewall, the lower plate, or the upper plate may be in thermal contact with the object. In this case, in the thermal contact, the resin layer is in direct contact with the lower plate or the like, or another element such as an insulating layer to be described later exists between the resin layer and the lower plate. It may mean a state in which heat transfer from the battery cell to the resin layer and from the resin layer to the lower plate is not obstructed. In the above, that it does not interfere with the transfer of heat, even when another element (ex. an insulating layer or a guiding part to be described later) exists between the resin layer and the lower plate, the total thermal conductivity of the other element and the resin layer. Is about 1.5 W/mK or more, 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, or is in contact with the resin layer and It means that the total thermal conductivity of the lower plate or the like is included in the above range even when the other elements are present. 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, It may be 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 present.
[35]
Of the first and second filler-containing curable resin layers, at least a thermally conductive cured resin layer to be described later may be in thermal contact with the lower plate or the like, and may also be in thermal contact with the battery cell. Through the adoption of the above structure, the unit volume while securing heat dissipation characteristics while significantly reducing various fastening parts or cooling equipment of the modules that were previously required when configuring a general battery module or a battery pack that is an assembly of such modules A module in which more battery cells are accommodated can be implemented. Accordingly, in the present application, a smaller, lighter, and high-output battery module can be provided.
[36]
6 is an exemplary cross-sectional view of the battery module. For example, the module includes: a case 10 including a side wall 10b and a lower plate 10a as shown in 6; It may have a shape including a plurality of battery cells 20 accommodated in the case and a resin layer 30 in contact with both the battery cells 20 and the case 10. 6 is a view of the resin layer 30 present on the lower plate 10a side, but the battery module of the present application includes a resin layer in the same shape as FIG. 6 on the upper plate side.
[37]
In the above structure, the lower plate or the like in contact with the resin layer 30 may be a lower plate having thermal conductivity as described above.
[38]
The contact area between 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 of the total area of ​​the lower plate. The upper limit of the contact area is not particularly limited, and may be, for example, 100% or less or about 100% or less.
[39]
When the upper plate or the lower plate is thermally conductive and the cured resin layer in contact therewith 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 schematically shown in FIG. 6, heat H can be easily discharged to the lower plate or the like by the above structure, and by contacting the lower plate or the like with the cooling medium CW, even in a more simplified structure, You can make it easier to dissipate heat.
[40]
Each of the first and second cured resin layers may have a thickness in a range of, for example, about 100 μm to 5 mm or about 200 μm to 5 mm. In the structure of the present application, the thickness of the resin layer may be set to an appropriate thickness in consideration of desired heat dissipation properties or durability. The thickness may be the thickness of the thinnest portion of the resin layer, the thickness of the thickest portion, or an average thickness.
[41]
As shown in FIG. 6, a guiding part capable of guiding the battery cell 20 accommodated on at least one surface of the module case 10, for example, a surface 10a in contact with the resin layer 30 (10d) may exist. At this time, the shape of the guiding portion 10d is not particularly limited, and an appropriate shape may be employed in consideration of the shape of the battery cell to be applied, and the guiding portion 10d is formed integrally with the lower plate, etc. Or it may be attached separately. The guiding part 10d may be formed of a thermally conductive material, for example, a metal material such as aluminum, gold, pure silver, tungsten, copper, nickel, or platinum in consideration of the aforementioned thermal contact. In addition, although not shown in the drawings, a slip sheet or an adhesive layer may be present between the battery cells 20 to be accommodated. In the above, the separator sheet may serve as a buffer when charging and discharging the battery cell.
[42]
The resin layer or the battery module to which the resin layer is applied may have at least one or more of the physical properties described later. Each physical property to be described later is independent, and one of the physical properties does not prioritize the other, and the resin layer may satisfy at least one or two or more of the physical properties described below.
[43]
In one example, at least one of the first and second filler-containing cured resin layers 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 Hereinafter, it may be 10 W/mK or less, 5 W/mK or less, 4.5 W/mK or less, or about 4.0 W/mK or less. As described above, when the resin layer is a thermally conductive resin layer, the lower plate, the upper plate, and/or the sidewall to which the resin layer is attached may have a thermal conductivity of 10 W/mK or more. In this case, the portion of the module case indicating 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 a value measured according to, for example, ASTM D5470 standard or ISO 22007-2 standard. The method of making the thermal conductivity of the resin layer into the above range is not particularly limited. For example, the thermal conductivity of the resin layer can be adjusted by using a filler having thermal conductivity as a filler included in the resin layer.
[44]
For example, among resin components known to be generally used as adhesives, acrylic resins, urethane resins, and silicone resins have similar heat conduction properties, epoxy resins have superior thermal conductivity compared to them, and olefin resins are epoxy resins. It is known to have high thermal conductivity compared to. Therefore, it is possible to select a resin having excellent thermal conductivity among the resins as needed. However, in general, it is difficult to secure the desired thermal conductivity with only the resin component, and a method of including a filler component having excellent thermal conductivity in an appropriate ratio in the resin layer as described below may also be applied.
[45]
The first and second filler-containing cured resin layers included in the battery module may both be a thermally conductive resin layer having the thermal conductivity, or at least one may be the thermally conductive resin layer. In one example, one of the first and second filler-containing cured resin layers may be the thermally conductive resin layer, and the other may be a resin layer having low thermal conductivity. Such a structure may be advantageous for the heat dissipation characteristics of the battery module.
[46]
In this case, the thermal conductivity of the resin layer with low thermal conductivity is less than 1.5 W/mK, less than about 1 W/mK, less than about 0.8 W/mK, less than 0.6 W/mK, less than 0.4 W/mK, or less than 0.2 W/mK. I can. In the above, the lower limit of the thermal conductivity is not particularly limited, and may be about 0 W/mK or more or 0 W/mK or more.
[47]
In a battery module, the heat resistance of the resin layer or the battery module to which the resin layer is applied 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/W or less, or about 2.8 It may be below K/W. When the resin layer or the battery module to which the resin layer is applied is controlled so that the thermal resistance in this range is displayed, excellent cooling efficiency or heat dissipation efficiency can be secured. The method of measuring the heat resistance is not particularly limited. For example, it can be measured according to ASTM D5470 standard or ISO 22007-2 standard.
[48]
The resin layer is also subjected to a thermal shock test, for example, after holding the battery at a low temperature of about -40°C for 30 minutes and then raising the temperature to 80°C for 30 minutes as one cycle, and repeating the cycle 100 times. It may be required to be formed so as not to be separated from, peeled off, or cracked from the module case or battery cell of the module. For example, when the battery module is applied to a product requiring a long warranty period (about 15 years or more in the case of a vehicle), such as a vehicle, the above-described performance may be required to secure durability.
[49]
The first and second filler-containing cured resin layers may be electrically insulating resin layers. In the above-described structure, the resin layer exhibits electrical insulation, so that the performance of the battery module can be maintained and stability can be ensured. The electrical insulating resin layer has an insulation breakdown voltage of about 3 kV/mm or more, about 5 kV/mm or more, about 7 kV/mm or more, 10 kV/mm or more, 15 kV/mm or more, or It may be 20 kV/mm or more. The dielectric breakdown voltage is not particularly limited as the resin layer exhibits excellent insulation as the value increases, but considering the composition of the resin layer, 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 as described above can also be controlled by adjusting the insulation properties of the resin component of the resin layer. For example, the dielectric breakdown voltage can be adjusted by applying an insulating filler in the resin layer. In general, among thermally conductive fillers, ceramic fillers as described later are known as components capable of securing insulation.
[50]
As the cured resin layers containing the first and second fillers, a flame-retardant resin layer may be applied in consideration of stability. In the present application, the term flame-retardant resin layer may mean a resin layer exhibiting a V-0 rating in UL 94 V Test (Vertical Burning Test). Through this, it is possible to secure stability against fire and other accidents that may occur in the battery module.
[51]
The first and second filler-containing cured resin layers 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. A resin layer exhibiting a specific gravity in this range is advantageous for manufacturing a more lightweight battery module. The lower the specific gravity is, the lower the value is, the more advantageous it is to reduce the weight of the module, and thus the lower limit thereof is not particularly limited. For example, the specific gravity may be about 1.5 or more or 2 or more. The component added to the resin layer may be adjusted so that the resin layer exhibits specific gravity in the above range. For example, when a filler is added, a filler capable of securing a desired thermal conductivity even at a specific gravity as low as possible, that is, a method of applying a filler having a low specific gravity or applying a filler having a surface treatment may be used.
[52]
It is appropriate that the first and second filler-containing cured resin layers do not contain volatile substances as much as possible. For example, the resin layer may have a ratio of non-volatile components of at least 90% by weight, at least 95% by weight, or at least 98% by weight. In the above, the nonvolatile component and its ratio can be defined in the following manner. That is, the non-volatile portion may be defined as a portion remaining after the resin layer is maintained at 100°C for about 1 hour, and thus the ratio is the initial weight of the resin layer and maintained at 100°C for about 1 hour. It can be measured based on the later ratio.
[53]
The first and second filler-containing cured resin layers may have excellent resistance to deterioration as necessary, but stability in which the surface of the module case or battery cell does not react chemically as possible may be required.
[54]
It may be advantageous that the first and second filler-containing cured resin layers also have a low shrinkage during the curing process or after curing. Through this, it is possible to prevent the occurrence of delamination or voids that may occur during the manufacturing or use of the module. The shrinkage rate may be appropriately adjusted within a range capable of exhibiting the above-described effect, and may be, for example, less than 5%, less than 3%, or less than about 1%. Since the shrinkage ratio is more advantageous as the value is lower, its lower limit is not particularly limited.
[55]
It may be advantageous that the first and second filler-containing cured resin layers also have a low coefficient of thermal expansion (CTE). Through this, it is possible to prevent the occurrence of delamination or voids that may occur during the manufacturing or use of the module. The coefficient of thermal expansion may be appropriately adjusted within a range capable of exhibiting the above-described effect, for example, less than 300 ppm/K, less than 250 ppm/K, less than 200 ppm/K, less than 150 ppm/K, or about 100 It may be less than ppm/K. Since the coefficient of thermal expansion is more advantageous as the value is lower, its lower limit is not particularly limited.
[56]
The tensile strength of the cured resin layer containing the first and second fillers may be appropriately adjusted, thereby ensuring excellent impact resistance, and thus providing a module exhibiting appropriate durability. Tensile strength can be adjusted, for example, in a range of about 1.0 MPa or more.
[57]
In the cured resin layer containing the first and second fillers, elongation may be appropriately adjusted, and through this, it is possible to provide a module exhibiting adequate durability by securing excellent impact resistance. The elongation may be adjusted in a range of, for example, about 10% or more or about 15% or more.
[58]
It may be advantageous for the first and second filler-containing cured resin layers to also exhibit an appropriate hardness. For example, if the hardness of the resin layer is too high, the resin layer becomes too brittle, which may adversely affect reliability. In addition, impact resistance and vibration resistance can be secured and durability of the product can be secured by controlling the hardness of the resin layer. The resin layer, for example, has a hardness of less than 100, 99 or less, 98 or less, 95 or less, or 93 or less in Shore A type, or has a hardness of less than about 80, about 70 or less, or about 70 or less in Shore D type. It may be 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 the shore A type, or about 5 or more or about 10 or more in the shore OO type. The hardness of the resin layer is usually influenced by the kind or ratio of the filler contained in the resin layer, and when an excessive amount of filler is included, the hardness usually increases. However, just as silicone resins usually exhibit lower hardness than other resins such as epoxy or urethane, the resin component included in the resin layer also affects the hardness.
[59]
The first and second filler-containing cured resin layers may also have a 5% weight loss temperature in thermogravimetric analysis (TGA) of 400° C. or higher, or a balance of 800° C. may be 70 wt% or more. Due to this characteristic, the stability of the battery module at high temperature may be further improved. The residual amount of 800°C may be about 75% by weight or more, about 80% by weight or more, about 85% by weight or more, or about 90% by weight or more in another example. The remaining amount of 800° C. may be about 99% by weight or less in another example. The thermogravimetric analysis (TGA) may be measured within a range of 25° C. to 800° C. at a temperature increase rate of 20° C./min in a nitrogen (N 2 ) atmosphere of 60 cm 3 /min . The thermogravimetric analysis (TGA) result can also be achieved through control of the composition of the resin layer. For example, the residual amount of 800° C. is usually influenced by the type or ratio of the filler contained in the resin layer, and when an excessive amount of the filler is included, the residual amount increases. However, since silicone resins generally have higher heat resistance than other resins such as epoxy or urethane, the residual amount is higher, and the resin component included in the resin layer also affects its hardness.
[60]
The type of the resin layer is not particularly limited as long as it is possible to effectively fix the battery cells, and if necessary, the above-mentioned physical properties can be imparted, and any known curable resin material may be used. Materials that can be used include acrylic resins, epoxy resins, urethane resins, olefin resins, urethane resins, EVA (Ethylene vinyl acetate) resins, or silicone resins, and thus the resin layer includes the resins. can do. The resin layer may contain the resin as a main component in the resin component. That is, among all resin components included in the resin layer, the acrylic resin, epoxy resin, urethane resin, olefin resin, urethane resin, EVA (Ethylene vinyl acetate) resin or silicone resin is about 70% by weight. Or more, about 75% or more, about 80% or more, about 85% or more, or about 90% or more. The ratio may be about 99% or less or about 95% or less.
[61]
The material forming the resin layer, that is, the resin composition, may be an adhesive material as described above, and may be a solvent type, an aqueous system, or a solventless type. I can.
[62]
The resin layer material may be an active energy ray curing type, a moisture curing type, a heat curing type, a room temperature curing type, or the like, and also a room temperature curing type may be appropriate in consideration of the convenience of a manufacturing process described later.
[63]
As described above, the first and second filler-containing cured resin layers are layers formed by curing the curable resin composition. In order to realize the unique structure of the present application, the following physical properties are required for the curable resin composition. First of all, in order to secure thixotropy or to secure thermal conductivity, if necessary, the resin composition may contain a very large amount of filler. In this case, the resin composition is sufficiently low in viscosity as described above to secure injection processability. Need to indicate In addition, if only a low viscosity is shown, it is also difficult to secure fairness, and thus appropriate thixotropy is required, and it may be necessary to proceed at room temperature while curing itself to show excellent adhesion.
[64]
In the present application, as a resin composition securing such properties, a urethane-based resin composition is applied. That is, the resin layer may be a urethane-based resin layer, that is, a resin layer containing a urethane resin as a main component in the resin component.
[65]
The urethane-based resin composition includes a main composition portion containing at least a polyol or the like; And it may be a two-part type including a curing agent composition portion containing at least an isocyanate compound, such a two-part type may be blended to prepare a resin composition, and the resin layer may be formed by curing it.
[66]
Accordingly, the urethane resin layer may include at least the polyol-derived unit and the polyisocyanate-derived unit. In this case, the polyol-derived unit may be a unit formed by urethane reaction of the polyol with the polyisocyanate, and the polyisocyanate-derived unit may be a unit formed by urethane reaction of the polyisocyanate with the polyol.
[67]
As the urethane-based resin composition, a resin composition containing a polyol that is amorphous or sufficiently low in crystallinity as at least a polyol contained in the main composition for securing the above properties may be applied.
[68]
In the above, the term amorphous means a case in which the crystallization temperature (Tc) and melting temperature (Tm) are not observed in DSC (Differential Scanning calorimetry) analysis, and in this case, the DSC analysis is performed at a rate of -80°C/min. It can be carried out within the range of ℃ to 60 ℃, for example, after raising the temperature from 25 ℃ to 60 ℃ at the above rate, it can be measured by reducing the temperature to -80 ℃ again, and raising the temperature to 60 ℃ again. In addition, the sufficiently low crystallinity is that the melting point (Tm) observed in the DSC analysis is about 20°C or less, about 15°C or less, about 10°C or less, about 5°C or less, about 0°C or less, about- It means a case of 5°C or less, about -10°C or less, or about -20°C or less. In the above, the lower limit of the melting point is not particularly limited, and for example, the melting point may be about -80°C or higher, about -75°C or higher, or about -70°C or higher.
[69]
As the polyol, an ester-based polyol to be described later may be exemplified. That is, among ester-based polyols, carboxylic acid-based polyols or caprolactone-based polyols, specifically polyols having a structure described later, effectively satisfy the above-described characteristics.
[70]
In general, carboxylic acid-based polyols are formed by urethane-reacting a component containing a dicarboxylic acid and a polyol (ex. diol or triol, etc.), and caprolactone-based polyol is made of caprolactone and a polyol (ex. diol or triol, etc.). It is formed by reacting a component containing urethane, and at this time, a polyol that satisfies the above-described physical properties can be formed by controlling the type and ratio of each component.
[71]
In one example, the polyol may be a polyol represented by Formula 1 or 2 below.
[72]
[Formula 1]
[73]

[74]
[Formula 2]
[75]

[76]
In Formulas 1 and 2, X is a dicarboxylic acid-derived unit, Y is a polyol-derived unit, for example, a triol or diol unit, and n and m are arbitrary numbers.
[77]
In the above, the dicarboxylic acid-derived unit is a unit formed by urethane reaction of a dicarboxylic acid with a polyol, and the polyol-derived unit is a unit formed by urethane reaction of a polyol with dicarboxylic acid or caprolactone.
[78]
That is, when the hydroxy group of the polyol and the carboxyl group of the dicarboxylic acid react, the water (HO 2 ) molecule is desorbed by the condensation reaction , and an ester bond is formed. X in Formula 1 is the dicarboxylic acid is esterified by the condensation reaction. After forming a bond, it refers to a portion excluding the ester bond, and Y is a portion excluding the ester bond after the polyol forms an ester bond by the condensation reaction, and the ester bond is represented in Chemical Formula 1. .
[79]
In addition, Y in Formula 2 also represents a portion excluding the ester bond after the polyol forms an ester bond with caprolactone.
[80]
Meanwhile, in the case where the polyol-derived unit of Y is a unit derived from a polyol containing three or more hydroxy groups such as a triol unit, a structure in which the Y portion is branched in the structure of the above formula may be implemented.
[81]
The type of the dicarboxylic acid-derived unit of X in Formula 1 is not particularly limited, but in order to secure the unit and desired physical properties, a phthalic acid unit, an isophthalic acid unit, a terephthalic acid unit, a trimellitic acid unit, a tetrahydrophthalic acid unit, and a 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 unit, 2,2-dimethylglutaric acid unit, maleic acid unit, fumaric acid unit, itaconic acid unit, and any one unit selected from the group consisting of fatty acid units In view of the glass transition temperature of the cured resin layer, an aliphatic dicarboxylic acid-derived unit is more advantageous than an aromatic dicarboxylic acid-derived unit.
[82]
On the other hand, in the formulas 1 and 2, the type of the polyol-derived unit of Y is not particularly limited, but in order to secure the unit and desired physical properties, an ethylene glycol unit, a propylene glycol unit, a 1,2-butylene glycol unit, 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-ethylhexyldiol unit, 1 ,5-pentanediol unit, 1,10-decanediol unit, 13-cyclohexanedimethanol unit, 1,4-cyclohexanedimethanol unit, any one or 2 selected from the group consisting of glycerin unit and trimethylolpropane unit May be more than one.
[83]
Meanwhile, in Formula 1, n is an arbitrary number, and the range may be selected in consideration of the desired physical properties, and may be, for example, about 2 to 10 or 2 to 5.
[84]
Further, in Formula 2, m is an arbitrary number, and the range may be selected in consideration of desired physical properties, and may be, for example, about 1 to 10 or 1 to 5.
[85]
When n and m are excessively large in Chemical Formulas 1 and 2, crystallinity of the polyol may be enhanced.
[86]
The molecular weight of the polyol as described above may be adjusted in consideration of the desired low viscosity characteristics, durability or adhesiveness, and may be, for example, in the range of about 300 to 2000. The molecular weight referred to in the present specification may be, for example, a weight average molecular weight measured using GPC (Gel Permeation Chromatograph), and unless otherwise specified in the specification, the molecular weight of a polymer refers to a weight average molecular weight.
[87]
The type of polyisocyanate included in the curing agent composition portion of the urethane-based resin composition is not particularly limited, but it may be advantageous to have an alicyclic type in order to secure desired physical properties.
[88]
That is, the polyisocyanate is tolyene diisocyanate, diphenylmethane diisocyanate, phenylene diisocyanate, polyethylenephenylene polyisocyanate, xylene diisocyanate, tetramethylxylene diisocyanate, triazine diisocyanate, naphthalene diisocyanate, and triphenyl. Aromatic polyisocyanate compounds such as methane triisocyanate, and aliphatic polyisocyanates such as hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate, norbornane diisocyanate methyl, ethylene diisocyanate, propylene diisocyanate or tetramethylene diisocyanate Or alicyclic polyisocyanates such as transcyclohexane-1,4-diisocyanate, isoborone diisocyanate, bis(isocyanate methyl)cyclohexane diisocyanate or dicyclohexylmethane diisocyanate, or any one of the above or two or more carboxylates. Although bodyimide-modified polyisocyanate or isocyanurate-modified polyisocyanate, etc. can be used, application of polyisocyanate other than aromatic is suitable.
[89]
The ratio of the polyol and the polyisocyanate in the resin composition is not particularly limited and is appropriately controlled so that their urethane reaction is possible.
[90]
In order to include other components such as a filler and a flame retardant to be described later in the resin layer, the resin composition may be cured by adding a desired additive to the main body and/or curing agent composition.
[91]
The resin layer may include a filler in consideration of the above-described thermal conductivity, insulation, heat resistance (TGA analysis) or specific gravity. If necessary, the use of an appropriate filler can ensure thermal conductivity and the like in the above range. In one example, the filler included in the cured resin layer containing at least a thermally conductive filler may be a thermally conductive filler. The term thermally conductive filler in the present application means 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. 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 the thermally conductive filler that can be used is not particularly limited, but a ceramic filler can be applied in consideration of insulation properties and the like. For example, ceramic particles such as alumina, aluminum nitride (AlN), boron nitride (BN), silicon nitride, SiC or BeO may be used. In addition, if the insulating properties of the resin layer can be secured, application of a carbon filler such as graphite can be considered. The shape or ratio of the filler contained in the resin layer is not particularly limited, and is selected in consideration of the viscosity of the resin composition, the possibility of sedimentation in the resin layer, the desired heat resistance or thermal conductivity, insulation, filling effect, or dispersibility. Can be. In general, as the size of the filler increases, the viscosity of the resin composition increases, and the likelihood that the filler precipitates in the resin layer increases. Also, as the size decreases, the thermal resistance tends to increase. Therefore, in consideration of the above points, an appropriate type of filler may be selected, If necessary, two or more fillers may be used. In addition, it is advantageous to use a spherical filler in consideration of the amount to be filled, but a filler in the form of a needle or plate may also be used in consideration of the formation of a network or conductivity. In one example, the resin layer 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 0.01 µm or more, 0.1 or more, 0.5 µm or more, 1 µm or more, 2 µm or more, 3 µm or more, 4 µm or more, 5 µm or more, or about 6 µm or more. In another example, the average particle diameter of the filler is 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 It may be 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.
Claim
[Claim 1]
A module case having an upper plate, a lower plate, and a side wall, wherein an inner space is formed by the upper plate, the lower plate, and the side wall; A plurality of battery cells present in the interior space of the module case; A battery module including a first filler-containing cured resin layer in contact with the upper plate while in contact with the battery cells, and a second filler-containing cured resin layer in contact with the lower plate while in contact with the battery cells.
[Claim 2]
The battery module according to claim 1, wherein the first filler-containing cured resin layer has a thermal conductivity of 1.0 W/mK or less, and the second filler-containing resin layer has a thermal conductivity of 1.5 W/mK or more.
[Claim 3]
The battery module according to claim 1, wherein the first and second filler-containing cured resin layers have a dielectric breakdown voltage of 10 kV/mm or more.
[Claim 4]
The battery module according to claim 1, wherein the first and second filler-containing cured resin layers have an adhesive strength of 200 gf/10 mm or more.
[Claim 5]
The battery module according to claim 1, wherein the first and second filler-containing cured resin layers are urethane resin layers.
[Claim 6]
The battery module according to claim 5, wherein the urethane resin layer comprises an ester-based polyol-derived unit and a polyisocyanate-derived unit.
[Claim 7]
The battery module according to claim 6, wherein the ester-based polyol is an amorphous ester-based polyol or an ester-based polyol having a melting point (Tm) of 20°C or less.
[Claim 8]
The battery module of claim 6, wherein the ester-based polyol is represented by the following Chemical Formula 1 or 2. [Formula 1] [Chemical Formula 2] In Formula 1 and 2, X is D and carboxylic acid-derived units, Y is a unit of a polyol derived, n is a number in the range of 2 to 10, m is a number in the range of 1 to 10.
[Claim 9]
The dicarboxylic acid derived unit is 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 according to claim 8, 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 unit , 2,2-dimethylglutaric acid unit, maleic acid unit, fumaric acid unit, itaconic acid unit, and a battery module of one or more units selected from the group consisting of fatty acid units.
[Claim 10]
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, and 1,3- Butanediol unit, 1,4-butanediol unit, 1,6-hexanediol unit, neopentyl glycol unit, 1,2-ethylhexyldiol unit, 1,5-pentanediol unit, 1,10-decanediol unit, 13- A battery module that is any one or two or more units selected from the group consisting of cyclohexanedimethanol units, 1,4-cyclohexanedimethanol units, glycerin units and trimethylolpropane units.
[Claim 11]
The battery module according to claim 6, wherein the polyisocyanate-derived unit is a unit derived from an alicyclic polyisocyanate, a carbodiimide-modified polyisocyanate-derived unit of an alicyclic polyisocyanate, or an isocyanurate-modified polyisocyanate-derived unit of an alicyclic polyisocyanate. .
[Claim 12]
According to claim 1, The first filler-containing cured resin layer is fumed silica, clay, calcium carbonate, alumina, AlN (aluminum nitride), BN (boron nitride), silicon nitride (silicon nitride), SiC, BeO or carbon filler Battery module containing.
[Claim 13]
The battery module of claim 12, wherein the cured resin layer containing the first filler comprises 100 to 300 parts by weight of a filler based on 100 parts by weight of the resin component.
[Claim 14]
The battery module according to claim 1, wherein the second filler-containing cured resin layer includes a thermally conductive filler that is a ceramic particle or a carbon-based filler.
[Claim 15]
The battery module according to claim 14, wherein the second filler-containing cured resin layer includes 500 to 2,000 parts by weight of a filler based on 100 parts by weight of the resin component.
[Claim 16]
The battery module according to claim 1, wherein the first or second filler-containing cured resin layer contains a thixotropic agent, a diluent, a dispersant, a surface treatment agent, a flame retardant, or a coupling agent.
[Claim 17]
The battery module according to claim 1, wherein the first or second filler-containing resin layer has a thickness in a range of 100 μm to 5 mm.
[Claim 18]
Injecting a resin composition into a module case having an upper plate, a lower plate, and side walls forming an interior space; A method of manufacturing a battery module according to claim 1, comprising the steps of accommodating the battery cell in the module case and curing the resin composition to form a cured resin layer containing first and second fillers.
[Claim 19]
A battery pack comprising two or more battery modules of claim 1 that are electrically connected to each other.
[Claim 20]
A vehicle comprising the battery module of claim 1 or the battery pack of claim 20.