KR102521472B1 - High-integration battery pack and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a highly integrated battery pack and a method for manufacturing the same. In the present invention, the density of batteries is improved by aligning the batteries using a cassette fastening method, and unnecessary work space can be reduced by removing a cell protection device inside the battery pack. In addition, the capacity of the battery pack may be increased by improving the heat dissipation characteristics of the heat dissipation resin included in the battery pack.

Description

High-integration battery pack and manufacturing method thereof

The present invention relates to a highly integrated battery pack and a manufacturing method thereof.

Recently, as interest in eco-friendliness and lightweighting has increased, research on eco-friendly vehicles such as hybrid vehicles and electric vehicles has been actively conducted.

Research on electric vehicles is focused on large-capacity batteries, which are the power source of electric vehicles. Lithium ion batteries have been widely used in portable electronic devices since their commercialization in 1990, and exhibit light weight, high energy density, and voltage compared to other secondary batteries. Lithium ion batteries are used as a next-generation energy source as well as a large-capacity energy source such as hybrid vehicles because it is easy to optimize the shape and material of the battery according to its purpose.

However, a large-capacity lithium ion battery as a vehicle power source includes a plurality of unit cells, and the unit cells are used in the form of a battery pack connected in series or parallel.

Since a battery pack increases in volume due to the inclusion of a plurality of unit cells, in order to minimize the size, a plurality of unit cells are densely arranged. The unit cells generate heat during charging or discharging. If it is not discharged quickly, deterioration of the unit cells is accelerated, and there is a high possibility that local temperature differences may occur due to heat generated from each unit cell or that high heat may be generated during high power driving. This is a thermal runaway phenomenon that impairs the efficiency and stability of the battery, which greatly affects the performance and lifespan of the battery. Therefore, a system capable of efficiently managing heat generated during charging and discharging of the battery and high output is required.

In addition, in a conventional battery pack, after arranging a plurality of unit cells on a battery tray, inserting the lower end of a bolt into a hole in the battery tray, inserting the fastening piece while positioning the fastening piece on the upper end of the battery, and tightening the nut. It is manufactured by tightening method.

However, in the case of manufacturing the battery pack as described above, there are disadvantages in that assembly is inconvenient and unnecessary work space is required.

Republic of Korea Patent Publication No. 10-2019-0000210 (2019.01.02. Publication)

An object of the present invention is to provide a method for manufacturing a battery pack with increased density by utilizing a cassette fastening method.

In order to achieve the above object, the present invention is a battery case; a plurality of battery cells provided inside the battery case; And a heat dissipation resin provided in a space between the battery case and the battery cell, wherein the plurality of battery cells are fixed at regular intervals using a cassette and then the cassette is removed, and the cassette has a clip portion and a support portion. Including, it provides a battery pack characterized in that the battery cells are aligned by fixing to the clip portion.

In addition, the present invention comprises the steps of preparing a heat dissipating resin composition; aligning the battery cells to the cassette; inserting the cassette into a battery case; forming a first heat-dissipating resin layer by primarily injecting the heat-dissipating resin composition into a battery case; removing the cassette; and forming a second heat-dissipating resin layer by secondarily injecting the heat-dissipating resin composition into the battery case. and assembling a case, wherein the cassette includes a clip part and a support part, and the cells are fixed and aligned to the clip part.

In the present invention, the density of the batteries is improved by aligning the batteries using the cassette fastening method, and unnecessary work space can be reduced by removing the cell protection device inside the battery pack.

In addition, in the present invention, the energy capacity in the battery pack can be increased by improving the heat dissipation characteristics of the heat dissipation resin included in the battery pack.

In the present invention, by applying a manufacturing process using a cassette in the process of manufacturing a battery pack to which a heat dissipation resin is applied, a manufacturing method capable of aligning battery cells without a cell protection device and a fixing device inside the battery pack is provided.

In the battery pack manufactured in this way, unnecessary space inside the pack can be eliminated, and a battery pack having a large energy capacity can be manufactured by inserting more cells into the battery pack having a limited volume.

1 is a schematic image of a battery pack according to a comparative example.
2 is a schematic image of a battery pack according to the present invention.
3 is a flowchart illustrating a method of manufacturing a battery pack according to the present invention.

Hereinafter, in order to explain the present invention in more detail, preferred embodiments according to the present invention will be described in more detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms.

The present invention provides a battery pack including a battery module in which a plurality of battery cells are assembled in a cassette fastening method.

1 is a schematic diagram of a battery pack according to a comparative example, in which (a) is a cross-sectional view of one side and (b) is a cross-sectional view of the other side. Figure 2 is a schematic diagram of a battery pack according to an embodiment of the present invention, Figure 2 (a) is a cross-sectional view of one side, (b) is a cross-sectional view of the other side.

Referring to FIG. 1 , the conventional battery pack includes support foams 27 on both sides of the battery module to fix the battery module 20 including a plurality of battery cells 21, and thus the battery case 10 and the battery module. It can be seen that the interval between (20) is wide. On the other hand, referring to FIG. 2, since the battery pack 1 of the present invention does not include a support form 27, which is a separate fixing device, a battery module including a battery case 10 and a plurality of battery cells 21 ( 20) is characterized by a very narrow gap between them.

In the battery pack 1 of the present invention, heat dissipation resin is applied instead of the support foam 27, which is a separate fixing and protection device, between the battery case 10 and the battery module 20 including a plurality of battery cells 21. It is characterized by a very narrow spacing.

The battery pack 1 includes a battery case 10; a plurality of battery cells 21 provided inside the battery case; and a heat dissipation resin 22 provided in a space between the battery case 10 and the battery cell 21, and the plurality of battery cells 21 may be electrically connected.

The battery pack 1 may configure the battery module 20 by arranging the plurality of battery cells 21 inside the battery case in a clip fixing method using a cassette (not shown). there is.

Specifically, the plurality of battery cells 21 may be aligned and fixed at regular intervals using a cassette, and then the cassette may be removed. Thus, the distance between the plurality of battery cells 21 may be the same as the thickness of the clip portion of the cassette.

Specifically, the plurality of battery cells 21 may be aligned at regular intervals using a cassette, fixed through primary injection and curing of a heat dissipating resin, and then removed from the cassette. Thus, the distance between the plurality of battery cells 21 may be the same as the thickness of the clip portion of the cassette.

The cassette includes a clip part and a support part, and the cassette may be composed of a clip part holding the battery cell 21 on a hard material such as plastic or metal and a support part capable of standing the cassette. The cells 21 can be fixed and aligned. More specifically, the cassette may be arranged in a fixed position in a support groove provided under the battery case 10 .

The clip part of the cassette is a device for fixing the battery cells 21 and can fix the interval between the battery cells 21 at a constant level, and part or all of the clip part may be coated with a rubber material. The height of the clip portion may be 1/5 to 1/3 or 1/4 to 1/3 of the length of the battery cell 21 . By having the same height as described above, attachment and detachment of the battery cell to the clip part can be facilitated.

In addition, the thickness of the clip portion may be 5 mm or less or 3 mm or less, and having such a thickness of the clip portion reduces the space between the battery cells 21 and the battery cells 21 to improve the density of the battery cells 21 The battery cell 21 may be spaced at an appropriate interval between the battery cells 21 to maintain a temperature difference of 5° C. or more.

The support part of the cassette is a pillar on which the cell-coupled cassette can be erected, and the support part may have a size of 0.1 to 1 mm in the form of a release-treated pin, and the support pin may have a structure that can be separated from the cassette. there is. In addition, the distance between the battery cell and the bottom surface of the battery case may be maintained at 5 mm or less, and the temperature difference between the battery cell and the outer wall of the case may be maintained at 5° C. or less.

By using the clip fixing method using a cassette as described above, the density of battery cells can be increased and unnecessary work space can be reduced compared to fastening with bolts.

The plurality of battery cells 21 may be arranged parallel to each other at regular intervals in the clip portion of the cassette, and electrically connect adjacent battery cells 21 to each other so that power of required voltage and current is output. Specifically, the battery cells 21 may be inserted into the battery case 10 to configure the battery module 20, and the battery cells 21 may be aligned using a cassette as described above.

In the battery pack 1 , the space between the battery module 20 and the wall of the battery case 10 may be 10 to 50 cm ³ or 10 to 50 cm ³ . Specifically, in the battery pack 1, the space between the battery module 20 and the outer wall of the battery case 10 may be reduced by 50% to 90% or 70% to 90% compared to a battery pack to which a heat dissipation resin is not applied. This has the same effect as reducing a dead zone inside the battery case 10 .

In this case, the voltage output from each battery cell 21 may be monitored by connecting a measuring tool to the sensing unit at a portion where the battery cells 21 adjacent to each other are connected.

The battery cell 21 includes an assembly in which a positive electrode plate, a separator, and a negative electrode plate are stacked, and may be sealed in a case together with an electrolyte, and terminals respectively connected to the positive electrode plate and the negative electrode plate may be located outside the cell case.

The battery module 20 including the battery cells 21 may be fixed with a bracket 23 provided on one side, and specifically, in a state in which a plurality of battery cells 21 are aligned, the bracket 23 provided on one side ) can be fixed.

In addition, a busbar 24 may be provided on one side of the battery module including the battery cells, and the busbar 24 may be connected to a sensing unit. Specifically, a bus bar 24 may be provided at an upper end of the battery module 20 . The busbar 24 serves to connect each battery module 20 and transmits it to the power supply unit.

The battery module 20 including the battery cell 21 has a battery management system (BMS) 25 on one side, and a connector provided at an end of a cable transmitting information of the battery pack to the BMS 25 can be connected. The BMS 25 serves to diagnose and control the state of the battery. An insulation board 26 may be further provided between the BMS 25 and the battery module 20 .

The battery pack according to the present invention includes a heat dissipating resin provided in a space between the battery case and the battery cell, and specifically, a heat dissipating resin layer may be formed by applying a heat dissipating resin to an empty space between the battery case and the battery cell. there is. The heat-dissipating resin may be a form in which a thermally conductive filler is uniformly dispersed in a polyurethane resin prepared by reacting a polyol with an isocyanate.

The battery pack 1 may be formed by injecting a heat dissipating resin 22 and curing the plurality of battery cells 21 to be completely submerged. Specifically, the heat dissipation resin 22 may be injected to a thickness that completely fills the space between the battery cell 21 and the battery case 10, and the thickness is most preferably 5 mm or less, 13 mm or less, or 30 mm or less. A space may be provided between the battery cell and the battery case.

In addition, the injection height of the heat dissipating resin 22 included in the battery pack 1 is most preferably 5 mm or less from the uppermost layer of the battery case 10, and may have a space of 13 mm or less or 30 mm or less.

By including the heat dissipation resin as described above, the battery pack of the present invention can increase the battery energy capacity by increasing the heat dissipation efficiency.

Specifically, the heat dissipation resin is a polyurethane resin prepared by reacting polyol and isocyanate; and a thermally conductive filler uniformly dispersed in the polyurethane resin, and may optionally include an additive. Specifically, the heat dissipation resin contains 20% to 40% by weight of polyol, 5% to 15% by weight of solvent, 30% to 60% by weight of thermally conductive filler, 5% to 15% by weight of isocyanate, and 0.1% to 0.1% by weight of additives. It can be prepared with a heat dissipating resin composition containing at a rate of 2.0% by weight. More specifically, the heat dissipation resin composition contains 25% to 35% by weight of polyol, 5% to 10% by weight of solvent, 45% to 55% by weight of thermally conductive filler, 8% to 10% by weight of isocyanate, and 0.7% by weight of additives. It may be included in a ratio of % to 1.5% by weight.

The thermally conductive filler includes aluminum oxide (Al ₂ O ₃ ), aluminum nitride (AlN), boron nitride (BN), silicon nitride (Si ₃ N ₄ ), silicon carbide (SiC), beryllium oxide (BeO), and zinc oxide (ZnO). and aluminum hydroxide (Al(OH) ₃ ).

Specifically, the average diameter of the thermally conductive filler may be 1 to 120 μm, and more specifically, 1 to 100 μm, 1 to 80 μm, or 5 to 30 μm. By having a diameter of the same size as above, the heat transfer efficiency of the heat dissipating resin can be improved.

In addition, the thermally conductive filler is formed on the surface of the coating layer through a pretreatment reaction with the coating material, the coating material is formed on the surface of the thermally conductive filler, at least one of a coupling agent, a polymer resin and graphite carbon can include The coating material may include 0.1 to 1.0 wt%, 0.2 to 1.0 wt%, or 0.2 to 0.5 wt% of the thermally conductive filler. By including the thermally conductive filler as described above, bonding strength may be improved by increasing adhesion between the polyurethane resin and the thermally conductive filler.

The coating layer may have a thickness of 1 Å to 50 μm, 1 nm to 50 μm, 10 nm to 10 μm, or 10 nm to 1 μm.

The coupling agent is (3-glycidyloxypropyl)trimethoxysilane ((3-Glycidyloxypropyl)trimethoxysilane), (3-glycidyloxypropyl)triethoxysilane ((3-Glycidyloxypropyl)triethoxysilane), It includes at least one of diethoxy (3-glycidyloxypropyl) methylsilane and 3-glycidoxypropyldimethoxymethylsilane.

The pretreatment method of coating the coupling agent may be performed by impregnating a thermally conductive filler into a solution obtained by mixing 0.5 to 3% by weight of the coupling agent in ethanol to treat the surface.

The polymer resin includes at least one of silane, urethane, silicone, and epoxy.

The metal oxide includes at least one of aluminum oxide (Al ₂ O ₃ ), aluminum nitride (AlN), boron nitride (BN), and beryllium oxide (BeO), and the metal oxide has an average diameter of 10 nm to 100 μm. can be

The pretreatment method of coating the polymer resin and the metal oxide may be performed by mixing and impregnating a mixture of the polymer resin and the metal oxide in a wet coating method, followed by heat treatment at a temperature of 60 to 120 ° C and drying. In this case, it is microencapsulated to block electrical conductivity by metal as much as possible and improve thermal conductivity.

The graphitic carbon may include at least one of activated carbon, graphite, graphene oxide, and carbon nanotubes. Specifically, the graphitic carbon may be graphite or graphene oxide.

The pretreatment method for coating the graphitic carbon may be a dry coating method or a wet coating method. In the dry coating method, heat treatment may be performed at 60 to 150° C. after simply mixing the thermally conductive filler and graphite carbon. The wet coating method may be performed by mixing and impregnating a thermally conductive filler into a solution in which graphite carbon is dispersed, followed by heat treatment at a temperature of 60 to 120° C. and drying.

mixing a polyol, a solvent, and a thermally conductive filler to form a mixture; And adding isocyanate to the mixture to prepare a composition; provides a method for producing a heat dissipating resin composition for a secondary battery comprising a.

The present invention comprises the steps of preparing a heat dissipating resin composition; aligning the battery cells to the cassette; inserting the cassette into a battery case; forming a first heat-dissipating resin layer by primarily injecting the heat-dissipating resin composition into a battery case; removing the cassette; and forming a second heat-dissipating resin layer by secondarily injecting the heat-dissipating resin composition into the battery case. And it provides a method for manufacturing a battery pack comprising a case assembling step.

3 is a flowchart illustrating a method of manufacturing a battery pack according to the present invention. Referring to Figure 3, the manufacturing method of the battery pack of the present invention comprises the steps of preparing a heat dissipating resin composition; aligning the battery cells to the cassette; inserting the cassette into a battery case; forming a first heat-dissipating resin layer by primarily injecting the heat-dissipating resin composition into a battery case; removing the cassette; and forming a second heat-dissipating resin layer by secondarily injecting the heat-dissipating resin composition into the battery case. Combining at least one of a bracket, a bus bar, and a BMS; And it may include a case assembling step.

The method of manufacturing the battery pack includes the step of bonding the electrodes of the battery cells, the order of bonding the electrodes of the battery cells is different depending on the direction of the electrodes of the battery cells, and the direction of the electrodes is the direction of the side of the battery case. If located at , after assembling the battery cell into the cassette, performing a step of bonding the electrode of the battery cell before inserting it into the battery case, or removing the cassette when the direction of the electrode is located at the top of the battery case Thereafter, a step of bonding the electrodes of the battery cells may be performed before the step of forming the second heat dissipation resin layer.

The manufacturing step of the heat dissipating resin composition may include the following detailed steps.

The manufacturing step of the heat dissipating resin composition may include forming a polyol solution by mixing a polyol and a solvent; adding a thermally conductive filler to the polyol solution; and preparing a composition by adding isocyanate to the mixture. Specifically, the step of preparing the heat dissipating resin composition may be performed at a temperature of 20 °C to 40 °C or 20 °C to 30 °C.

In the step of forming the polyol solution, the polyol may include a polyether-based or ester-based polyol. Specifically, the polyol is polyethylene glycol (PEG), polypropylene glycol (PPG), polytetramethylene ether glycol (PTMG), polyhexamethylene ether glycol (PHMG), polyethylene adipate glycol, polypropylene adipate glycol, polybutylene It includes at least one or more of adipate glycol, polyhexamethylene adipate glycol, and polycaprolactone polyol.

The solvent includes at least one of methylene chloride, acetone and ethyl acetate. Specifically, the solvent may be methylene chloride, acetone or ethyl acetate. The viscosity of the composition can be controlled by using the solvent as described above.

Adding a thermally conductive filler to the polyol solution is a step of injecting the thermally conductive filler into the polyol solution.

The thermally conductive filler includes aluminum oxide (Al ₂ O ₃ ), aluminum nitride (AlN), boron nitride (BN), silicon nitride (Si ₃ N ₄ ), silicon carbide (SiC), beryllium oxide (BeO), and zinc oxide (ZnO). and aluminum hydroxide (Al(OH) ₃ ).

Specifically, the average diameter of the thermally conductive filler may be 1 to 120 μm, and more specifically, 1 to 100 μm, 1 to 80 μm, or 5 to 30 μm. By having a diameter of the same size as above, the heat transfer efficiency of the heat dissipating resin can be improved.

The thermally conductive filler forms a coating layer through a pretreatment reaction with a coating material, and the coating material is formed on the thermally conductive filler and may include at least one of a coupling agent, a polymer resin, and graphite carbon. The coating material may include 0.1 to 1.0 wt%, 0.2 to 1.0 wt%, or 0.2 to 0.5 wt% of the thermally conductive filler. By including the thermally conductive filler as described above, bonding strength may be improved by increasing adhesion between the polyurethane resin and the thermally conductive filler.

The coating layer may have a thickness of 1 Å to 50 μm, 1 nm to 50 μm, 10 nm to 10 μm, or 10 nm to 1 μm.

The coupling agent is (3-glycidyloxypropyl)trimethoxysilane ((3-Glycidyloxypropyl)trimethoxysilane), (3-glycidyloxypropyl)triethoxysilane ((3-Glycidyloxypropyl)triethoxysilane), It includes at least one of diethoxy (3-glycidyloxypropyl) methylsilane and 3-glycidoxypropyldimethoxymethylsilane.

The pretreatment method of coating the coupling agent may be performed by impregnating a thermally conductive filler into a solution obtained by mixing 0.5 to 3% by weight of the coupling agent in ethanol to treat the surface.

The polymer resin includes at least one of silane, urethane, silicone, and epoxy.

The metal oxide includes at least one of aluminum oxide (Al ₂ O ₃ ), aluminum nitride (AlN), boron nitride (BN), and beryllium oxide (BeO), and the metal oxide has an average diameter of 10 nm to 100 μm. can be

The pretreatment method of coating the polymer resin and the metal oxide may be performed by mixing and impregnating a mixture of the polymer resin and the metal oxide in a wet coating method, followed by heat treatment at a temperature of 60 to 120 ° C and drying. In this case, it is microencapsulated to block electrical conductivity by metal as much as possible and improve thermal conductivity.

The graphitic carbon may include at least one of activated carbon, graphite, graphene oxide, and carbon nanotubes. Specifically, the graphitic carbon may be graphite or graphene oxide.

The pretreatment method for coating the graphitic carbon may be a dry coating method or a wet coating method. In the dry coating method, heat treatment may be performed at 60 to 150° C. after simply mixing the thermally conductive filler and graphite carbon. The wet coating method may be performed by mixing and impregnating a thermally conductive filler into a solution in which graphite carbon is dispersed, followed by heat treatment at a temperature of 60 to 120° C. and drying.

In the adding of the thermally conductive filler to the polyol solution, additives may be further added to the mixture. The additive may include at least one of a dispersing agent, an antifoaming agent, and a leveling agent.

The dispersant includes at least one of sodium naphthalene sulfonate, sodium phenol sulfonate, sodium alkyl diphenyl ether disulfonate, alkylbenzene sulfonate, sodium polyacrylate, and polyoxyethylene alkyl ether.

The antifoaming agent includes at least one or more of a silicone-based antifoaming agent, a higher fatty acid-based antifoaming agent, and a lower alcohol.

Specifically, the silicone-based antifoaming agent includes at least one of polydimethylsiloxane (PDMS), a copolymer with Poly(Alkylene Oxide), and Polytrifluoro propylmethylsiloxanes, and the fatty acid-based antifoaming agent isoamyl stearic acid, diglycol lauric acid , distearyl succinic acid, at least one of sorbitan monolauric acid and polyoxyethylene sorbitan, and the lower alcohol-based antifoaming agent is methanol, octanol, 3-heptanol, 2-ethylhexanol and de- and at least one of tetra-amylphenoxyethanol.

The leveling agent includes at least one of polyalkyl acrylate, polyalkylvinyl ether, cellulose acetate butylate, dimethyl polysiloxane, and methylphenyl polysiloxane.

In the step of preparing the composition (S300), 20% to 40% by weight of polyol, 5% to 15% by weight of solvent, 30% to 60% by weight of thermally conductive filler, 5% to 15% by weight of isocyanate and 0.1% by weight of additives The composition can be prepared by mixing in a ratio of weight% to 2.0% by weight. Specifically, the step of preparing the composition (S300) includes 25% to 35% by weight of polyol, 5% to 10% by weight of solvent, 45% to 55% by weight of thermally conductive filler, and 8% to 10% by weight of isocyanate. And additives can be prepared by mixing in a ratio of 0.7% by weight to 1.5% by weight.

The isocyanate is not particularly limited as long as it reacts with polyol to form polyurethane. Specifically, the isocyanate may include at least one of methylene diphenyl diisocyanate (MDI) and toluene diisocyanate (TDI).

In the preparing of the heat-dissipating resin, a process of removing air bubbles from the heat-dissipating resin composition may be additionally performed. The process of removing air bubbles from the heat dissipating resin composition may be performed using vacuum defoaming, pressure defoaming, or a method of adding an antifoaming agent.

The vacuum defoaming may remove air bubbles by reducing the pressure of the heat dissipating resin composition at room temperature to a pressure of 20 to 100 mmHg.

The pressurized defoaming may remove air bubbles by applying pressure of 3 bar or more to the heat dissipating resin composition at room temperature.

The reason why the vacuum defoaming and the pressure defoaming are performed at room temperature is that curing is generally accelerated when the temperature is high, and curing is initiated before bubbles escape.

The antifoaming agent may be added before injecting the heat dissipating resin composition into the battery pack, and the antifoaming agent includes at least one of a silicone-based antifoaming agent, a higher fatty acid-based antifoaming agent, and a lower alcohol. Specifically, the antifoaming agent is included in an amount of 0.1% by weight to 0.5% by weight.

Specifically, the silicone-based antifoaming agent includes at least one of polydimethylsiloxane (PDMS), a copolymer with Poly(Alkylene Oxide), and Polytrifluoro propylmethylsiloxanes, and the fatty acid-based antifoaming agent isoamyl stearic acid, diglycol lauric acid , distearyl succinic acid, at least one of sorbitan monolauric acid and polyoxyethylene sorbitan, and the lower alcohol-based antifoaming agent is methanol, octanol, 3-heptanol, 2-ethylhexanol and de- and at least one of tetra-amylphenoxyethanol.

In the step of arranging the battery cells in the cassette, a plurality of battery cells may be arranged parallel to each other in a line by fixing the plurality of battery cells to the clip portion of the cassette. Specifically, the battery cells may constitute a battery module in a state of being inserted into a cell case.

Specifically, the cassette includes a clip part and a support part, and the cassette may be composed of a clip part for holding battery cells on a hard material such as plastic or metal, and a support part for erecting the cassette. You can sort by fixing . More specifically, the cassette may be arranged in a fixed position in a support groove provided at a lower portion of the battery case.

The clip part of the cassette is a device for fixing the cells, and can fix the interval between the cells at a constant level, and part or all of the clip part may be coated with a rubber material. The height of the clip portion may be 1/5 to 1/3 or 1/4 to 1/3 of the length of the battery cell. By having the same height as described above, attachment and detachment of the battery cell to the clip part can be facilitated.

In addition, the thickness of the clip part may be 5 mm or less or 3 mm or less, and by having such a thickness of the clip part, it is possible to improve the density of battery cells by reducing the space between battery cells and cells, and appropriate spacing between cells can be maintained so that the temperature difference does not widen more than 5 ℃.

By using the clip fixing method using a cassette as described above, the density of battery cells can be increased and unnecessary work space can be reduced compared to fastening with bolts.

In addition, the step of arranging the battery cells in the cassette may additionally perform the step of bonding the electrodes of the battery cells, which may be a process of mounting and connecting harness wires and temperature sensors.

In the step of inserting the cassette into the battery case, a pin may be installed in a groove inside the battery case to fix the cassette in which the battery cells are arranged in place. Specifically, the support pin of the cassette is mounted in the groove inside the case. can do.

In the forming of the first heat-dissipating resin layer, the prepared heat-dissipating resin composition may be injected and cured so that the injection height of the heat-dissipating resin is lower than the height of the cassette.

Specifically, in the forming of the first heat-dissipating resin layer, the heat-dissipating resin composition may be injected into four or more inlets provided in the lower housing using a dispenser.

In the first heat-dissipating resin layer forming step, the heat-dissipating resin composition may be injected at a temperature of 10 to 30° C. at an injection rate of 100 ml to 600 ml. Specifically, the step of injecting the heat-dissipating resin composition is the heat-dissipating resin composition at an injection rate of 100 ml to 600 ml, 200 ml to 550 ml, or 300 ml to 500 ml per minute at a temperature of 10 to 30 ° C. or 15 to 25 ° C. can be injected.

In the removing of the cassette, the first heat dissipation resin layer may be formed by curing the firstly injected heat dissipation resin, and then removed.

The second heat dissipation resin layer forming step may be performed in the same manner as the first heat dissipation resin layer forming step, but may include aligned battery cells or may be formed by injecting heat dissipation resin so that the inside of the battery case is filled and then cured.

Through the second heat dissipation resin layer forming step, the battery pack 1 may be manufactured by injecting and curing the heat dissipation resin 22 so that the plurality of battery cells 21 are completely submerged. Specifically, the heat dissipation resin 22 may be injected to a thickness that completely fills the space between the battery cell 21 and the battery case 10, and the thickness is most preferably 5 mm or less, and the battery thickness is 13 mm or less or 30 mm or less. It may have a space between the cell and the battery case.

Specifically, the injection height of the heat dissipating resin 22 injected into the battery pack 1 is most preferably 5 mm or less from the uppermost layer of the battery case 10, and may have a space of 13 mm or less or 30 mm or less.

Prior to the case assembling step, after the heat dissipation resin is completely cured through the second heat dissipation resin layer forming step, the battery case may be fastened by combining the harness and the BMS.

The harness may be mounted by connecting the wires from the bracket and the busbar to the BMS board in the step of bonding the battery cell electrodes.

In addition, the case assembling step may include a process of attaching a label and packaging the battery pack.

The scope of the present invention is indicated by the following claims, and all changes or modifications derived from the meaning and scope of the claims and equivalent concepts should be interpreted as being included in the scope of the present invention.

1: battery pack 10: battery case
20: battery module 21: battery cell
22: heat dissipation resin 23: bracket
24: bus bar 25; BMS
26: insulation board 27: support foam

Claims (14)

battery case; a plurality of battery cells provided inside the battery case; And a battery pack including a heat dissipation resin provided in a space between the battery case and the battery cell,
The plurality of battery cells are arranged and fixed at regular intervals using a cassette, and then the cassette is removed,
The cassette includes a clip part and a support part, and the battery cells are fixed and aligned in the clip part,
The battery pack is manufactured by injecting and curing a heat dissipating resin so that the battery cells are completely immersed, and is injected to a thickness that completely fills the space between the battery cells and the battery case,
The heat-dissipating resin is a form in which a thermally conductive filler is uniformly dispersed in a polyurethane resin prepared by reacting a polyol and an isocyanate,
The thermally conductive filler is a battery pack, characterized in that a coating layer is formed on the surface of the thermally conductive filler. delete delete According to claim 1,
The battery pack, characterized in that the plurality of battery cells are arranged parallel to each other at regular intervals in the clip portion of the cassette. According to claim 1,
The battery pack, characterized in that the thickness of the space between the battery cell and the battery case is 30 mm or less. According to claim 1,
The battery pack is further provided with a bracket, a bus bar and a BMS. preparing a heat dissipating resin composition; aligning the battery cells to the cassette; inserting the cassette into a battery case; forming a first heat-dissipating resin layer by primarily injecting the heat-dissipating resin composition into a battery case; removing the cassette; and forming a second heat-dissipating resin layer by secondarily injecting the heat-dissipating resin composition into the battery case. And a case assembly step,
The method of manufacturing a battery pack, characterized in that the cassette includes a clip portion and a support portion, and the cells are fixed and aligned in the clip portion. According to claim 7,
The method of manufacturing the battery pack includes the step of bonding the electrodes of the battery cells, the order of bonding the electrodes of the battery cells is different according to the direction of the electrodes of the battery cells,
When the direction of the electrode is located in the side direction of the battery case, performing a step of bonding the electrode of the battery cell before inserting it into the battery case after assembling the battery cell into a cassette, or
A method of manufacturing a battery pack, characterized in that performing the step of bonding the electrodes of the battery cells after the step of removing the cassette and before the step of forming the second heat dissipation resin layer when the direction of the electrode is located at the top of the battery case. According to claim 7,
The method of manufacturing a battery pack, characterized in that the ratio of the height of the clip portion of the cassette is 1/5 to 1/3 or less with respect to the length of the battery cell. According to claim 7,
The method of manufacturing a battery pack, characterized in that the step of aligning the battery cells to the cassette further performs the step of bonding the electrodes of the battery cells. According to claim 7,
The method of manufacturing a battery pack, characterized in that in the forming of the first heat dissipation resin layer, the injection height of the heat dissipation resin is formed lower than the cassette height. According to claim 7,
The method of manufacturing a battery pack, characterized in that the step of removing the cassette is removed after curing the first injected heat dissipation resin. According to claim 7,
In the step of inserting the cassette into the battery case, a pin is installed in a groove inside the battery case to fix it in place. According to claim 7,
The method of manufacturing a battery pack further comprising the step of coupling the harness and the BMS after the step of forming the second heat dissipation resin layer and before the step of assembling the case.

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