Title of the invention: Method of manufacturing a battery module
Technical field
[One]
This application claims the benefit of priority based on Korean Patent Application No. 10-2017-0172480 filed on December 14, 2017, and all contents disclosed in the documents of the Korean patent application are included as part of this specification.
[2]
The present application relates to a method of manufacturing a battery module.
Background
[3]
The secondary battery includes a nickel cadmium battery, a nickel hydride battery, a nickel zinc battery, or a lithium secondary battery, and a representative one is a lithium secondary battery.
[4]
Lithium secondary batteries mainly use lithium oxide and carbon materials as positive and negative active materials, respectively. A lithium secondary battery includes an electrode assembly in which a positive electrode active material and a negative electrode active material are applied, respectively, and an electrode assembly in which a negative electrode plate is disposed with a separator interposed therebetween, and an exterior material for sealing and receiving the electrode assembly together with an electrolyte. And pouch-type secondary batteries.
[5]
In this specification, a single secondary battery may be referred to as a battery cell.
[6]
When used in a medium or large-sized device such as a vehicle or a power storage device, a large number of battery cells may be electrically connected to each other to increase capacity and output to form a battery module or a battery pack.
[7]
For example, Patent Document 1 discloses a battery module that is light, has excellent output to volume, and has excellent heat dissipation characteristics.
[8]
The battery module disclosed in Patent Document 1 includes battery cells housed in a case, and a resin layer is present between the battery cells and the case. This resin layer is formed by injecting a curable resin composition in the manufacturing process through an injection hole formed in the case and then curing it.
[9]
However, in the process of injecting the curable resin composition, the internal pressure in the case increases, and after the injecting process, the increased internal pressure is relieved and the injected curable resin composition is again discharged out of the injection port (see FIG. 1). The curable resin discharged back in this way needs to be removed by a separate process.
Detailed description of the invention
Technical challenge
[10]
The present application provides a method of manufacturing a battery module. An object of the present application is to provide a manufacturing method capable of solving a process delay or contamination of a case due to a reverse discharge phenomenon that occurs when a curable resin composition is injected through an injection port.
Means of solving the task
[11]
In the case where the measurement temperature affects the result among the physical properties mentioned in the present specification, the corresponding physical property is the physical property measured at room temperature, unless otherwise specified. The term room temperature is a natural temperature that is not warmed or reduced in temperature, and is usually a temperature within the range of about 10°C to about 30°C, or about 23°C or about 25°C. In addition, unless specifically stated otherwise in the specification, the unit of temperature is °C.
[12]
In the case where the measured pressure affects the result among the physical properties mentioned in the present specification, the corresponding physical properties are those measured at normal pressure, unless otherwise specified. The term atmospheric pressure is a natural temperature that is not pressurized or depressurized, and usually about 1 atmosphere is referred to as atmospheric pressure.
[13]
Hereinafter, a structure of a battery module manufactured by the manufacturing method of the present application will be described first.
[14]
The battery module manufactured in the present application includes a module case and a battery cell, and the battery cell is accommodated 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. Battery cells accommodated in the module case may be electrically connected to each other.
[15]
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 separate side walls, the lower plate and/or the upper plate may be assembled to form the module case. The shape and size of the module case is not particularly limited, and may be appropriately selected according to the purpose, the shape and number of battery cells accommodated in the internal space.
[16]
In the present specification, the terms upper plate and lower plate are terms of a relative concept used to distinguish them, since there are at least two plates constituting the module case except for the sidewall. In other words, it does not mean that the upper plate must be present on the upper side and the lower plate must be present on the lower side in the actual use state.
[17]
FIG. 2 is a view showing an exemplary module case 10, and is an example of a case 10 in the form of a box including one lower plate 10a and four side walls 10b. As shown in FIG. 2, the module case 10 may further include an upper plate 10c sealing the inner space.
[18]
3 is a schematic view of the module case 10 of FIG. 2 in which the battery cells 20 are accommodated, as viewed from above.
[19]
An injection hole is formed in the lower plate, the side wall and/or the upper plate of the module case. Such an injection hole may be formed on an upper plate and a lower plate in contact with the resin layer to be described later. The injection port is formed for a process of injecting a resin composition for forming a resin layer, as described later. The shape, number, and position of the injection ports may be adjusted in consideration of the injection efficiency of the resin composition. In one example, the injection hole may be formed on at least the lower plate and the upper plate.
[20]
In one example, the injection 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 port formed at this point, the resin layer can be injected so as to have a wide contact surface. The 1/4, 3/4, 3/8, or 7/8 points above are, for example, as shown in FIG. 4, the total length measured based on any one end surface (E) of the lower plate, etc. It is the ratio of the distance (A) to the location where the hole is formed 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. 4, the injection hole 50a is located in an approximately middle portion of the lower plate 10a.
[21]
The size and shape of the injection port are not particularly limited, and may be formed in consideration of injection efficiency of the resin layer material described later. For example, the injection hole may be a polygonal or amorphous shape such as a circle, an ellipse, a triangle or a square. The number of injection ports and the spacing thereof are also not limited, and as described above, the resin layer may be adjusted to have a large contact area such as the lower plate.
[22]
Observation holes (for example, 50b of FIG. 4) may be formed at ends of the upper plate and the lower plate in which the injection hole is formed. The observation hole may be for observing whether the injected composition is well injected to the end of the side wall, the lower plate, or the upper plate, for example, when the resin composition 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.
[23]
The module case may be a thermally conductive case. The term thermally conductive case refers to a case including a portion having a thermal conductivity of 10 W/mk or more, or at least as described above. 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.
[24]
A structure of a battery module according to an example 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 cells, as described below. In this structure, at least one of the first and second filler-containing cured resin layers may be a thermally conductive resin layer, and accordingly, at least an upper plate or a lower plate in contact with the thermally conductive resin layer is thermally conductive, It may include a thermally conductive portion.
[25]
A thermally conductive upper plate, lower plate or side wall; Or the thermal conductivity of the thermally conductive portion; in another example, about 20 W/mk or more, 30 W/mk or more, 40 W/mk or more, 50 W/mk or more, 60 W/mk or more, 70 W/mk or more, 80 W/mk or more, 90 W/mk or more, 100 W/mk or more, 110 W/mk or more, 120 W/mk or more, 130 W/mk or more, 140 W/mk or more, 150 W/mk or more, 160 W /mk or more, 170 W/mk or more, 180 W/mk or more, 190 W/mk or more, or about 195 W/mk or more. The higher the thermal conductivity, the higher the value is, the more advantageous it is in terms of heat dissipation characteristics of the module, and so 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 less than about 250 W/mK, 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 of the above-mentioned range, or may include at least a portion having the above-mentioned thermal conductivity.
[26]
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 to be described later. In addition, the portion having the thermal conductivity may be a portion in contact with a cooling medium such as cooling water. According to this structure, a structure capable of effectively discharging heat generated from the battery cell to the outside may be implemented.
[27]
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. 5, the pouch-type battery cell 100 may typically include an electrode assembly, an electrolyte, and a pouch case.
[28]
5 is an exploded perspective view schematically showing the configuration of an exemplary pouch-shaped cell, and FIG. 6 is a combined perspective view of the configuration of FIG. 5.
[29]
The electrode assembly 110 included in the pouch-shaped cell 100 may have a form in which one or more positive plates and one or more negative plates 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.
[30]
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 internal elements such as the electrode assembly 110. The metal layer of the electrode assembly 110 may protect internal elements such as an electrolyte, and may include a metal thin film such as aluminum in consideration of supplementation of electrochemical properties and heat dissipation by the electrode assembly 110 and the electrolyte. The metal thin film may be interposed between an insulating layer formed of an insulating material in order to secure electrical insulation from elements such as the electrode assembly 110 and an electrolyte or other elements outside the battery 100.
[31]
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 has a concave inner 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.
[32]
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.
[33]
The shape of the pouch-type cell described above is only 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.
[34]
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, the liquid phase or the low viscosity having sufficient fluidity may mean about 400 cP or less or a range of about 100 to about 400 cP (at room temperature, based on a shear rate of 2.5/s). The viscosity is the 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.
[35]
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.
[36]
In one example, each of the resin layers may be an adhesive layer. The term adhesive layer, when 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 about 400 gf/10mm or more it means. 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 about 500 gf/10mm or less.
[37]
By forming at least two filler-containing cured resin layers in the battery module, a battery module having excellent durability against external shock or vibration can be provided.
[38]
In the battery module, 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 may include, for example, a resin layer and the upper plate, lower plate and/or sidewall; Alternatively, it may mean that the battery cells are in direct contact, or other elements, for example, an insulating layer, etc. exist between them. In addition, the resin layer in contact with the thermally conductive sidewall, the lower plate, or the upper plate may be in thermal contact with the object. 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 hindered. In the above, that the transfer of heat is not hindered means that 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 about 4 W/mK or more, or the resin layer and contact with it This means that the overall thermal conductivity of the lower plate, etc., is within the above range even when the other factors are present. The thermal conductivity of the thermal contact is about 50 W/mK or less, 45 W/mk or less, 40 W/mk or less, 35 W/mk or less, 30 W/mk or less, 25 W/mk or less, 20 W/mk or less, 15 W/mk or less, 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.
[39]
Among the 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 structure as described above, the unit volume while securing heat dissipation characteristics while significantly reducing various fastening parts or cooling equipment of 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, it is possible to provide a battery module having a smaller, lighter weight and high output.
[40]
7 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 7; 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. FIG. 7 is a view of the resin layer 30 present on the lower plate 10a side, but the battery module includes a resin layer in the same shape as that of FIG. 7 on the upper plate side.
[41]
The contact area between the resin layer and the lower plate may be about 70% or more, 75% or more, 80% or more, 85% or more, 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.
[42]
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. 7, heat (H) can be easily discharged to the lower plate by the above structure, and by contacting the lower plate with the cooling medium (CW), even in a more simplified structure You can make it easier to dissipate heat.
[43]
Each of the first and second cured resin layers may have a thickness in a range of, for example, about 100 μm to about 5 mm or about 200 μm to about 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.
[44]
As shown in FIG. 7, 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 adopted 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, interlayer paper or an adhesive layer may be present between the battery cells 20 to be accommodated. In the above, the slipper may serve as a buffer during charging and discharging of the battery cell.
[45]
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.
[46]
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, 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 or less, 10 W/mK or less, 5 W/mK or less, 4.5 W/mK or less, or about 4.0 W/mK or less. As described above, when the resin layer is a thermally conductive resin layer, the lower plate, the upper plate, and/or the side wall to which the resin layer is attached may have a thermal conductivity of about 10 W/mK or more. In this case, the portion of the module case showing the thermal conductivity may be a portion in contact with a cooling medium, for example, cooling water. 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.
[47]
Among the resin components known to be generally used as adhesives, acrylic resins, urethane resins and silicone resins have similar thermal conductivity properties, epoxy resins have superior thermal conductivity compared to them, and olefin resins have higher thermal conductivity than epoxy resins. It is known to have a city. Therefore, it is possible to select one having excellent thermal conductivity among 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.
[48]
Both the first and second filler-containing cured resin layers included in the battery module may be thermally conductive resin layers having the thermal conductivity, and 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. This structure may be advantageous for heat dissipation characteristics of the battery module.
[49]
In this case, the thermal conductivity of the resin layer with low thermal conductivity is less than about 1.5 W/mK, less than 1 W/mK, less than 0.8 W/mK, less than 0.6 W/mK, less than 0.4 W/mK, or less than about 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.
[50]
In the battery module, the heat resistance of the resin layer or the battery module to which the resin layer is applied is about 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 It can be less than 2.8 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 ensured. 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.
[51]
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 level of performance may be required to secure durability.
[52]
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, 5 kV/mm or more, 7 kV/mm or more, 10 kV/mm or more, 15 kV/mm or more, or about 20 measured in accordance with ASTM D149. It may be more than kV/mm. 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 about 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 below are known as components capable of securing insulation.
[53]
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.
[54]
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 about 4.5 or less, 4 or less, 3.5 or less, or about 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 about 2 or more. Components added to the resin layer may be adjusted in order for the resin layer to exhibit specific gravity in the above range. For example, when a filler is added, a filler capable of securing a desired thermal conductivity even at as low a specific gravity as possible, that is, a filler having a low specific gravity by itself, or a filler having a surface treatment may be used.
[55]
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 nonvolatile content of about 90% by weight or more, 95% by weight or more, or about 98% by weight or more. 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.
[56]
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.
[57]
It may be advantageous for the first and second filler-containing cured resin layers to 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.
[58]
It may be advantageous for the first and second filler-containing cured resin layers to 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 about 300 ppm/K, less than 250 ppm/K, less than 200 ppm/K, less than 150 ppm/K, or about It may be less than 100 ppm/K. Since the coefficient of thermal expansion is more advantageous as the value is lower, the lower limit thereof is not particularly limited.
[59]
The tensile strength of the cured resin layer containing the first and second fillers may be appropriately adjusted, and through this, excellent impact resistance may be secured, and thus a module showing appropriate durability may be provided. The tensile strength can be adjusted in a range of, for example, about 1.0 MPa or more.
[60]
In the cured resin layer containing the first and second fillers, elongation may be appropriately adjusted, and through this, excellent impact resistance, etc. may be secured to provide a module exhibiting appropriate durability. The elongation may be adjusted in a range of, for example, about 10% or more or about 15% or more.
[61]
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 a product can be secured by controlling the hardness of the resin layer. The resin layer, for example, has a hardness of less than about 100, 99 or less, 98 or less, 95 or less, or about 93 or less in Shore A type, or has a hardness of less than about 80, 70 or less in Shore D type, or It may be about 65 or less or about 60 or less. The lower limit of the hardness is not particularly limited. For example, the hardness may be about 60 or more in 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-based 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.
[62]
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 these characteristics, the stability of the battery module at high temperatures may be further improved. In another example, the remaining amount of 800° C. may be about 75% by weight or more, 80% by weight or more, 85% by weight or more, or about 90% by weight or more. The residual 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 kind 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.
[63]
In one example, the battery module may further include an insulating layer between the module case and the battery cell or between the resin layer and the module case. 8 is an example of a case where the insulating layer 40 is formed between the resin layer 30 and the guiding portion 10d formed on the lower plate 10a of the case. By adding an insulating layer, it is possible to prevent problems such as electric short-circuit phenomenon or fire occurrence due to contact between the cell and the case due to impact that may occur during use. The insulating layer may be formed using an insulating sheet having high insulating properties and thermal conductivity, or may be formed by coating or injection of an insulating material. For example, in the method of manufacturing a battery module to be described later, a process of forming an insulating layer before injection of the resin composition may be performed. A so-called TIM (Thermal Interface Material) or the like may be applied to the formation of the insulating layer. In another method, the insulating layer may be formed of an adhesive material, and for example, the insulating layer may be formed using a resin layer having a low or no filler content such as a thermally conductive filler. Resin components that can be used to form the insulating layer include acrylic resin, olefin resin such as PVC (poly(vinyl chloride)), PE (polyethylene), epoxy resin, silicone, or EPDM rubber ((ethylene propylene diene monomer rubber). Rubber components, etc. may be exemplified, but are not limited thereto. The insulation layer has an insulation breakdown voltage of about 5 kV/mm or more, 10 kV/mm or more, and 15 kV/mm as measured in accordance with ASTM D149. Or more, 20 kV/mm or more, It may be 25 kV/mm or more or about 30 kV/mm or more. The dielectric breakdown voltage is not particularly limited as it exhibits excellent insulation as the value increases. For example, the dielectric breakdown voltage of the insulating layer may be about 100 kV/mm or less, 90 kV/mm or less, 80 kV/mm or less, 70 kV/mm or less, or about 60 kV/mm or less. The thickness of the insulating layer may be set in an appropriate range in consideration of the insulating property or thermal conductivity of the insulating layer, for example, about 5 μm or more, 10 μm or more, 20 μm or more, 30 μm or more, 40 μm or more, It may be about 50 μm or more, 60 μm or more, 70 μm or more, 80 μm or more, or about 90 μm or more. Further, the upper limit of the thickness is not particularly limited, and may be, for example, about 1 mm or less, about 200 μm or less, 190 μm or less, 180 μm or less, 170 μm or less, 160 μm or less, or 150 μm or less.
[64]
It relates to a method of manufacturing a battery module of the type as described above, which is an exemplary aspect of the present application. That is, the exemplary manufacturing method includes: a module case in which an inner space is formed by a lower plate and a side wall, and an injection hole is formed in the lower plate or side wall; A plurality of battery cells present in the internal space; And a resin layer in contact with the lower plate or the sidewall while in contact with the battery cell.
[65]
In the above manufacturing method, details of the battery cell and the resin layer, such as the specific structure of the case, its material and shape, etc., are as already described. However, the battery module is an example of a module that can be manufactured by the manufacturing method of the present application, and the manufacturing method of the present application includes other modules to be manufactured requiring a similar injection process in the manufacturing process in addition to the above-described module. It can also be applied to formation.
[66]
The manufacturing method of the present application includes a process of attaching a tape to the injection port before injecting the resin composition through the injection port. That is, the manufacturing method may include attaching a tape to cover the injection hole of the lower plate or the side wall. 9 is a schematic diagram of a lower plate or side wall 100 to which the tape 600 is attached to cover the injection hole 500.
[67]
In the manufacturing method of the present application, following the steps as described above, a device for injecting a resin composition is mounted to the inlet. In this process, the injection device may be mounted so that the injection device passes through the tape and is mounted to the injection hole. Such a process is schematically shown in FIG. 10, and the process can be performed by moving the injection device 700 toward the tape 600 covering the injection hole of the lower plate 100, as shown in FIG. As a result, as the tape is torn as shown in FIG. 11, the injection device may penetrate the tape and be mounted to the injection hole.
[68]
The type of injection device applied in this process is not particularly limited, and a nozzle or other device capable of injecting the resin composition may be used.
[69]
In the manufacturing method of the present application, after mounting the injection device as described above, the resin composition may be injected into the injection device.
[70]
In this manner, the above-described reverse discharge phenomenon can be prevented, or even if reverse discharge occurs, by removing the tape after removal of the injection device, the material that has been reverse discharged can be simply and cleanly removed.
[71]
In the manufacturing method of the present application, the type of tape attached to the injection port is not particularly limited, and an appropriate type may be used. For example, the tape may be paper, a polyester polymer film such as polyethylene terephthalate or polyethylene naphthalate, a cellulose polymer film such as diacetyl cellulose or triacetyl cellulose, an acrylic polymer film such as polymethyl methacrylate, Styrene polymer films, such as polystyrene and acrylonitrile/styrene copolymer (AS resin), and polycarbonate polymer films, etc. are mentioned. In addition, polyethylene, polypropylene, polyolefin having a cyclo- or norbornene structure, polyolefin-based polymer film such as ethylene/propylene copolymer, vinyl chloride-based polymer film, amide-based polymer film such as nylon or aromatic polyamide, imide-based Polymer film, sulfone polymer film, polyether sulfone polymer film, polyether ether ketone polymer film, polyphenylene sulfide polymer film, vinyl alcohol polymer film, vinylidene chloride polymer film, vinyl butyral polymer film, An allylate-based polymer film, a polyoxymethylene-based polymer film, an epoxy-based polymer film, or a film of a blend of the polymer may also be used. The attachment process can be performed by forming a known adhesive layer on one side of such a tape. In addition, there is no particular limitation on the thickness of the film, and an appropriate thickness may be selected according to the purpose.
[72]
In the method of the present application, the tape attached to cover the injection hole may have a smaller penetration auxiliary portion than the injection hole, and in another example, forming the penetration auxiliary portion after attaching the tape to the injection hole You can also perform additionally.
[73]
12 is an example of a case in which the penetration auxiliary portion 800 is formed, and the penetration auxiliary portion may be performed in a known manner such as, for example, a sheathing method on the tape.
[74]
After the auxiliary portion is formed, the injection device is mounted toward the auxiliary portion so that the injection device more effectively penetrates the tape and is mounted in the tape.
[75]
In the manufacturing method of the present application, a series of processes of attaching the tape, mounting the injection device, and injecting the resin composition may be performed in a state in which the battery cell is present in the inner space of the module case, or in a state in which the battery cell does not exist. However, in general, it can be performed while a plurality of battery cells are present in the internal space.
[76]
In the manufacturing method of the present application, a process of removing the attached tape following the injection process may be additionally performed.
[77]
In addition, any necessary process may be additionally performed. For example, when the injected resin composition is a curable resin, a process of curing the resin composition may be performed, and as described above, the first and second In order to form a structure in which the resin layer is simultaneously applied, the above process may be performed through the injection port of the lower plate, and the same process may be repeatedly performed through the injection port of the upper plate.
[78]
The type of the resin composition injected in the above process is not particularly limited, and any type may be used as long as it is formulated to form a resin layer as described above. For example, the resin composition may include an acrylic resin, an epoxy resin, a urethane resin, an olefin resin, a urethane resin, an EVA (Ethylene vinyl acetate) resin or a silicone resin, or a precursor of the resin.
[79]
As described above, the resin composition may be an adhesive material, and may be a solvent type, an aqueous type, or a non-solvent type, but it may be appropriate to be a solvent-free resin layer in consideration of convenience of a manufacturing process described below.
[80]
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 a room temperature curing type may be appropriate in consideration of the convenience of a manufacturing process described later.
[81]
In one example, the resin composition may be a curable resin composition. For example, in order to manufacture a battery module having the structure described above, the following physical properties are required for the curable resin composition. First, if necessary, in order to secure thixotropy or to secure thermal conductivity, a very large amount of filler may be included in the resin composition.Even in this case, the resin composition has sufficient low viscosity as described above to secure injection processability, etc. Need to indicate In addition, if only a low viscosity is shown, it is also difficult to ensure fairness, so that appropriate thixotropy is required, and it may be necessary to proceed at room temperature while curing itself to show excellent adhesion.
[82]
In the present application, as a resin composition securing such characteristics, a urethane-based resin composition may be applied. That is, the resin layer may be a urethane-based resin layer, that is, a resin layer including a urethane resin as a main component of the resin component.
[83]
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.
[84]
For example, after mixing the main composition part and the curing agent composition by applying a known mixer such as a static mixer, the mixture may be injected through the injection device.
[85]
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.
[86]
As the urethane-based resin composition, at least as a polyol contained in the main composition for securing the above properties, a resin composition including a polyol having amorphous or sufficiently low crystallinity may be applied.
[87]
In the above, the term amorphousness refers to a case where the crystallization temperature (Tc) and melting temperature (Tm) are not observed in DSC (Differential Scanning calorimetry) analysis, and the DSC analysis is performed at a rate of -80 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 then raising the temperature to 60 ℃. In addition, the sufficiently low crystallinity in the above means that the melting point (Tm) observed in the DSC analysis is about 20°C or less, about 15°C or less, 10°C or less, 5°C or less, 0°C or less, -5°C or less, It means a case of about -10℃ or less or about -20℃ 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, -75°C or higher, or about -70°C or higher.
[88]
As the polyol as described above, an ester-based polyol 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.
[89]
In general, carboxylic acid-based polyols are formed by urethane reaction of a component containing a dicarboxylic acid and a polyol (ex. diol or triol, etc.), and the caprolactone-based polyol is made of caprolactone and a polyol (ex. diol or triol, etc.). It is formed by reacting with a urethane component, 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.
[90]
In one example, the polyol may be a polyol represented by Formula 1 or 2 below.
[91]
[Formula 1]
[92]

[93]
[Formula 2]
[94]

[95]
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.
[96]
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.
[97]
That is, when the hydroxy group of the polyol and the carboxyl group of the dicarboxylic acid react, the water (H 2 O) molecule is desorbed by the condensation reaction , and an ester bond is formed. X in Formula 1 is the dicarboxylic acid After forming an ester bond, it means a portion excluding the ester bond portion, and Y is also a portion excluding the ester bond after the polyol forms an ester bond by the condensation reaction, and the ester bond is represented in Formula 1 have.
[98]
In addition, Y in Formula 2 also represents a portion excluding the ester bond after the polyol forms an ester bond with caprolactone.
[99]
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 may be implemented in the structure of the above formula.
[100]
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, units derived from aliphatic dicarboxylic acids are more advantageous than units derived from aromatic dicarboxylic acids.
[101]
On the other hand, the type of the polyol-derived unit of Y in Formulas 1 and 2 is not particularly limited, but in order to secure the unit and desired physical properties, ethylene glycol unit, propylene glycol unit, 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 units and trimethylolpropane units May be more than one.
[102]
Meanwhile, in Formula 1, n is an arbitrary number, and the range may be selected in consideration of desired physical properties, and may be, for example, about 2 to 10 or 2 to 5.
[103]
In addition, 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.
[104]
When n and m in Formulas 1 and 2 are too large, the expression of crystallinity of the polyol may increase.
[105]
The molecular weight of the polyol as described above may be adjusted in consideration of the desired low viscosity characteristics, durability or adhesion, 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 means a weight average molecular weight.
[106]
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 be an alicyclic type in order to secure desired physical properties.
[107]
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; Aliphatic polyisocyanates such as hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate, norbornane diisocyanate methyl, ethylene diisocyanate, propylene diisocyanate or tetramethylene diisocyanate; Alicyclic polyisocyanates such as transcyclohexane-1,4-diisocyanate, isoborone diisocyanate, bis(isocyanate methyl)cyclohexane diisocyanate or dicyclohexylmethane diisocyanate; Or any one or two or more of the above carbodiimide-modified polyisocyanates or isocyanurate-modified polyisocyanates; And the like can be used, but application of polyisocyanates other than aromatic is suitable.
[108]
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.
[109]
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 the curing agent composition.
[110]
Accordingly, the resin composition may include a filler in consideration of the above-described thermal conductivity, insulation, heat resistance (TGA analysis) or specific gravity. When necessary, thermal conductivity in the above-described range can be secured through the use of an appropriate filler. In one example, the filler included in the cured resin layer containing at least a thermally conductive filler may be a thermally conductive filler. In the present application, the term thermally conductive filler refers 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. 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 type of thermally conductive filler that can be used is not particularly limited, but a ceramic filler may be applied in consideration of insulating 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 form or ratio of the filler contained in the resin composition 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. In addition, as the size decreases, the thermal resistance tends to increase. Therefore, in consideration of the above points, an appropriate type of filler can 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 a form such as a needle or plate may be used in consideration of network formation or conductivity. In one example, the resin layer may include a thermally conductive filler having an average particle diameter in the range of about 0.001 µm to about 80 µm. In another example, the average particle diameter of the filler may be about 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, 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, It may be 25 μm or less, 20 μm or less, 15 μm or less, 10 μm or less, or about 5 μm or less.
[111]
The ratio of the filler included in the thermally conductive resin layer or resin composition may be selected in consideration of the properties of the resin layer so that the above-described properties, for example, thermal conductivity, insulation, and the like can be secured. For example, the filler may be included within a range of about 50 to about 2,000 parts by weight based on 100 parts by weight of a resin component or a precursor thereof of the resin layer or resin composition. The weight part of the filler is about 100 parts by weight or more, about 150 parts by weight or more, 200 parts by weight or more, 250 parts by weight or more, 300 parts by weight or more, 350 parts by weight or more, 400 parts by weight or more, 500 parts by weight or more, It may be 550 parts by weight or more, 600 parts by weight or more, or about 650 parts by weight or more.
[112]
Therefore, the ratio of the filler in the resin composition may be adjusted according to the above contents.
[113]
A filler-containing cured resin layer that is not thermally conductive may include a filler depending on the purpose, for example, to ensure thixotropy. In this case, the filler need not be thermally conductive, and the ratio is not required to be particularly large as long as appropriate thixotropic properties are ensured.
[114]
The type of the filler contained in this resin layer is not particularly limited, and may be, for example, fumed silica, clay, calcium carbonate, or the like. Of course, if necessary, the resin layer or the resin composition may also contain a small amount of an appropriate type among the aforementioned thermally conductive fillers. The shape or 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. As described above, an appropriate type of filler may be selected in consideration of the viscosity of the resin composition, the possibility of sedimentation of the filler, or heat resistance, and if necessary, two or more fillers may be used. In one example, the average particle diameter of the filler included in the resin layer may be in the range of about 0.001 μm to about 80 μm. In another example, the average particle diameter of the filler may be about 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, 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, It may be 25 μm or less, 20 μm or less, 15 μm or less, 10 μm or less, or about 5 μm or less.
[115]
The ratio of the filler contained in the resin layer or resin composition having low thermal conductivity may be selected in consideration of desired thixotropic properties. For example, the filler may be included within a range of about 100 to about 300 parts by weight based on 100 parts by weight of the resin component of the resin layer or resin composition.
[116]
The resin layer or resin composition is a viscosity modifier, such as a thixotropic agent, a diluent, a dispersant, a surface treatment agent, for controlling the viscosity as necessary, for example, to increase or decrease the viscosity, or to control the viscosity according to shear force. Alternatively, it may further include a coupling agent and the like.
[117]
The thixotropy imparting agent may control the viscosity according to the shear force of the resin composition so that the manufacturing process of the battery module is effectively performed. As the thixotropic imparting agent that can be used, fumed silica and the like can be exemplified.
[118]
Diluents or dispersants are usually used to lower the viscosity of the resin composition, and any of various types known in the art may be used without limitation as long as it can exhibit the above-described action.
[119]
The surface treatment agent is for surface treatment of the filler introduced into the resin layer, and various types known in the art may be used without limitation as long as it can exhibit the above-described action.
[120]
In the case of the coupling agent, for example, it may be used to improve the dispersibility of a thermally conductive filler such as alumina, and any of various types known in the art may be used without limitation as long as it can exhibit the above-described action.
[121]
The resin layer or resin composition may further include a flame retardant or a flame retardant auxiliary. Such a resin layer or resin composition can form a flame retardant resin layer. As the flame retardant, a variety of known flame retardants may be applied without any particular limitation, and for example, a solid filler-type flame retardant or a liquid flame retardant may be applied. Examples of the flame retardant include, but are not limited to, an organic flame retardant such as melamine cyanurate, or an inorganic flame retardant such as magnesium hydroxide.
[122]
When the amount of filler to be filled in the resin layer or the resin composition is large, a liquid-type flame retardant material (TEP, Triethyl phosphate or TCPP, tris(1,3-chloro-2-propyl)phosphate, etc.) may be used. In addition, a silane coupling agent capable of acting as a flame retardant enhancing agent may be added.
Effects of the Invention
[123]
In the present application, it is possible to provide a method of manufacturing a battery module with a simple process and low cost without occurrence of a reverse discharge phenomenon.
Brief description of the drawing
[124]
1 is a photograph showing a reverse discharge phenomenon.
[125]
2 is a diagram showing an exemplary module case.
[126]
3 is a diagram showing a form in which a battery cell is accommodated in a module case.
[127]
4 is a view of an exemplary lower plate in which an injection port and an observation hole are formed.
[128]
5 and 6 are diagrams illustrating an exemplary battery pouch that can be used as a battery cell.
[129]
7 and 8 are diagrams showing the structure of an exemplary battery module.
[130]
9 is a schematic diagram of a form in which a tape is attached so as to cover the injection port.
[131]
10 is a schematic diagram of a process of attaching an injection device to an injection port, and FIG. 11 is a view showing an injection device mounted on the injection port.
[132]
Fig. 12 is a schematic diagram of a case where a penetration auxiliary part is formed in the tape.
Mode for carrying out the invention
[133]
Hereinafter, the battery module of the present application will be described through Examples and Comparative Examples, but the scope of the present application is not limited by the ranges presented below.
[134]
[135]
1. Viscosity of resin composition
[136]
The viscosity of the resin composition was measured under a shear rate condition of 0.01 to 10.0/s at room temperature using a rheological property analyzer (ARES). The viscosity mentioned in the examples is the viscosity at the point of the shear rate of 2.5/s, and a thixotropic index (TI) can be determined through the ratio of the viscosity at the point at which the shear rate is 1.0/s and the point at 10.0/s.
[137]
[138]
Example 1.
[139]
Preparation of resin composition
[140]
As the resin composition, a two-component urethane adhesive composition was used. As a main composition, as a caprolactone polyol represented by Formula 2, the number of repeating units (m in Formula 2) is at a level of about 1 to 3, and as a polyol-derived unit (Y in Formula 2), ethylene glycol and Using a main composition comprising a polyol containing a propylene glycol unit (viscosity: about 350,000 to 400,000 cP, room temperature, based on 2.5/s shear rate), and a curing agent composition (viscosity: about 270,000 to 300,000 cP, room temperature, 2.5/s) As a shear rate standard), a composition containing polyisocyanate (HDI, Hexamethylene diisocyanate) was used. In the resin composition, as a filler, calcium carbonate was mixed in equal amounts in the main body and the curing agent composition so as to have a weight ratio of about 280 parts by weight to 100 parts by weight of the total solid content of the main and curing agent composition in order to secure thixotropy. In the formation of the resin layer, the base material and the curing agent composition were mixed and used in an equivalent amount. The viscosity of the main and curing agent compositions described in the examples is the viscosity in the state in which the filler is blended.
[141]
[142]
Manufacture of battery modules
[143]
As a module case having the shape as shown in FIG. 2, a module case having a lower plate made of aluminum, a side wall, and an upper plate was used. A guiding part for guiding mounting of the battery cell is formed on the inner side of the lower plate of the module case, and an injection hole 50a for injecting a resin composition as shown in FIG. 4 is formed at the center of the lower plate of the module case. It is formed at intervals, and an observation hole 50b is formed at the end. A bundle of pouches in which a plurality of battery pouches were stacked was stored in the module case. Subsequently, the upper plate was covered on the upper surface of the module case. Thereafter, as shown in FIG. 9, a tape 600 was attached to cover the injection hole 500 of the lower plate 100, and a small sheath was made in the center to form an auxiliary portion as shown in FIG. 12. In the above, as the tape 600, a tape having an acrylic adhesive formed on one side of a PET (poly(ethylene terephthalate)) base film having a thickness of about 30 μm to about 50 μm was used.
[144]
Subsequently, the injection nozzle was moved toward the cut portion of the tape in the manner shown in FIG. 10 and mounted in the shape shown in FIG. 11, and the resin composition was injected. The injection was performed until it was confirmed that the injected resin composition reached the observation hole. After the injection was completed, the injection device was removed and the tape was also removed.
[145]
As a result, there was no component of the resin composition discharged back at the injection port, and this series of processes was performed in less than 20 seconds.
[146]
[147]
Comparative Example 1.
[148]
A battery module was manufactured in the same manner as in Example 1, except that the resin composition was injected directly using an injection device without attaching a tape. As a result, a reverse discharge phenomenon as described in FIG. 1 was observed. Accordingly, in the process of removing the back-discharged resin composition with a solvent, a phenomenon in which the surface of the case was ground blackened by the filler in the resin composition was observed, and a time period of 20 minutes or more was also performed for the removal.
[149]
[150]
Comparative Example 2.
[151]
The tape was attached in the same manner as in Example 1, but a hole was previously drilled in the tape according to the shape of the injection port, and the tape was attached so that the drilled hole fits the injection port. That is, in the above example, the tape did not cover the injection port. In this way, a resin composition still remaining around the injection port was observed, and in the process of removing the resin composition, a phenomenon in which the surface of the case was also ground black by the filler in the resin composition was observed. In addition, compared to Comparative Example 1, the amount of the remaining resin composition was small, so the removal time was shortened, but it also took about 10 minutes.
Claims
[Claim 1]
A module case in which an internal space is formed by a lower plate and a side wall, and an injection hole is formed in the lower plate or the side wall; A plurality of battery cells present in the internal space; And a resin layer in contact with the lower plate or the side wall while being in contact with the battery cell, the method comprising: attaching a tape to cover the injection hole of the lower plate or the side wall; Mounting the injection device so that the injection device of the resin composition is mounted to the injection hole while penetrating the tape; And injecting the resin composition into the mounted injection device.
[Claim 2]
The method of claim 1, wherein the injection hole is formed at a point of 1/4 to 3/4 of the total length of the side wall or the lower plate.
[Claim 3]
The method of claim 1, wherein the tape attached to cover the injection port comprises a polyester film, an acrylic film, a polyolefin film, paper, a cellulose polymer film, a polystyrene film, or a polycarbonate film.
[Claim 4]
The battery module according to claim 1, wherein the tape attached to cover the injection hole has a penetrating auxiliary part having a size smaller than that of the injection hole, or forming the penetration auxiliary part after attaching the tape to the injection hole. Manufacturing method.
[Claim 5]
The method of manufacturing a battery module according to claim 4, wherein the injection device is mounted in the injection port toward the through auxiliary part.
[Claim 6]
The method of claim 1, wherein the injection of the resin composition is performed while a plurality of battery cells are present in the internal space.
[Claim 7]
The method of claim 1, further comprising removing the tape after the resin composition is injected.
[Claim 8]
The method of claim 1, wherein the resin composition has a room temperature viscosity of 400 cP or less at a shear rate of 2.5/s.
[Claim 9]
The method of claim 1, wherein the resin composition is a room temperature curable resin composition.
[Claim 10]
The method of claim 1, wherein the resin composition comprises a resin component which is an acrylic resin, an epoxy resin, a urethane resin, an olefin resin, a urethane resin, an EVA resin or a silicone resin, or contains any one or more precursors of the resins. Method of manufacturing a battery module.
[Claim 11]
The method of claim 10, wherein the resin composition further comprises a filler.
[Claim 12]
The method of claim 11, wherein the resin composition comprises a filler within a range of 50 to 2,000 parts by weight based on 100 parts by weight of a resin component or a precursor.