Cooling block for battery module and method of manufacturing the same

Abstract

The present disclosure relates to a cooling block for a battery module and a method for manufacturing the same. A cooling block for a battery module and a method for manufacturing the cooling block provide different thermal conductivity and strength for each region of the cooling block by selectively cooling each region. The cooling block includes a first cooling block for contacting the battery module on a first side and a second cooling block coupled to a second side of the first cooling block and forming a cooling channel. Cooling water may flow through a cooling channel disposed at an interface with the second side of the first cooling block. The first cooling block and the second cooling block are made of the same metal-based material, and the thermal conductivity and strength of the first cooling block are different from the thermal conductivity and strength of the second cooling block.

Description

Technical Field

[0001] The present disclosure relates to a cooling block for a battery module and a method of manufacturing the same, and more particularly, to a cooling block for a battery module and a method of manufacturing the same, the cooling block providing different thermal conductivity and strength to each region by performing selective cooling on each region. Background Art

[0002] Recently, technologies for improving the fuel or energy efficiency of vehicles using electric energy as a power source have been developed. With the increase in demand for hybrid electric vehicles (HEV) and electric vehicles (EV), and for the above-mentioned purpose, research for increasing battery capacity is ongoing.

[0003] Along with the demand for increased battery capacity, technology for dissipating heat generated by batteries during battery use has also been studied.

[0004] Methods of cooling a battery in a vehicle using electric energy as a power source are roughly classified into an air cooling method and a water cooling method.

[0005] Meanwhile, recently, as the battery capacity increases to improve fuel efficiency, more heat is generated. The air-cooled cooler has limited heat dissipation. Therefore, the air-cooled cooler is replaced with a water-cooled cooler with higher cooling efficiency.

[0006] A water-cooled cooler for cooling batteries includes a cooling block having cooling channels through which cooling water flows. The cooling block is manufactured by forming a top plate and a bottom plate and then bonding the plates to form the cooling channels through which cooling water flows.

[0007] Figure 1 is an exploded perspective view showing a conventional cooling block for a battery module, and Figure 2 is a cross-sectional view of a common cooling block for a battery module. The common cooling block for a battery module in the prior art includes: a first cooling block 10, which contacts the battery module 1 on a first side; and a second cooling block 20, which is coupled to the second side of the first cooling block 10 and forms a cooling channel 21. Cooling water flows through the cooling channel 21 at the interface with the second side of the first cooling block 10.

[0008] The cooling block for the battery module must be able to easily remove the heat generated from the battery module 1 using the cooling water flow. Therefore, it is usually made of aluminum or an aluminum alloy with high thermal conductivity. In addition, the first cooling block 10 and the second cooling block 20 are combined by brazing, and have high reliability in the combination to prevent the cooling water from leaking to the outside of the cooling block.

[0009] like Figure 1As shown, there is a possibility of cooling water leakage in the water-cooled cooling block. Therefore, the first cooling block 10 is formed in a wide flat plate shape so that: all battery modules 1 can contact the first cooling block 10; and the second cooling block 20 is coupled to the second side, and the second cooling block 20 has a cooling channel 21 through which cooling water flows.

[0010] Therefore, under the trend of increasing the size of the cooling module as the battery capacity increases, there is also a need to reduce the thickness in order to reduce weight and improve cooling performance.

[0011] On the other hand, aluminum silicon or aluminum silicon based 4xxx series alloys are often used as brazed filter metals to join the first cooling block 10 and the second cooling block 20. Aluminum silicon based filter metals are most often used because they have lower melting points than the base material and have a high affinity with the base material.

[0012] However, when the first cooling block 10 and the second cooling block 20 are combined by brazing, the base material needs to be heated to melt the filter metal. However, in this process, since a series of filter metals similar to the base material are used, the base material is also heated to a temperature close to the melting point. Therefore, when the base material that has been heat-treated to improve performance is combined by brazing, it is difficult to maintain the performance improvement effect due to the temperature to which the base material is heated. Therefore, for the brazed product, the product combined after brazing is heat-treated.

[0013] However, it is necessary to increase the contact area with the battery module as a heat generating body and reduce the thickness of the cooling block for the battery module for cooling efficiency. As a result, the cooling block is formed in a generally wide and thin shape. However, there is a problem that when the cooling block having such a shape is heat-treated, deformation occurs due to the temperature difference in the product.

[0014] The above description provided as the prior art of the present disclosure is only for helping understanding the background of the present disclosure and should not be construed as being included in the prior art known to those of ordinary skill in the art. Summary of the invention

[0015] The present disclosure provides a cooling block for a battery module and a method for manufacturing the cooling block. The cooling block is made of the same metal-based material but provides different thermal conductivity and strength for each area by partially controlling cooling.

[0016] A cooling block for a battery module according to an embodiment of the present disclosure includes: a first cooling block in contact with the battery module on a first side; and a second cooling block coupled to a second side of the first cooling block and forming a cooling channel. Cooling water flows through the cooling channel at an interface with the second side of the first cooling block. The first cooling block and the second cooling block are made of the same metal-based material. The thermal conductivity and strength of the first cooling block are different from the thermal conductivity and strength of the second cooling block.

[0017] The thermal conductivity of the first cooling block is higher than the thermal conductivity of the second cooling block.

[0018] The strength of the second cooling block is greater than that of the first cooling block.

[0019] The first cooling block and the second cooling block are made of an aluminum-based alloy.

[0020] The first cooling block and the second cooling block are welded, and then only the second cooling block is partially quenched.

[0021] According to an embodiment of the present disclosure, a method for manufacturing a cooling block for a battery module includes: a preparation step of preparing a first cooling block and a second cooling block, the first cooling block being in contact with the battery module on a first side of the first cooling block, the second cooling block being coupled to the second side of the first cooling block and forming a cooling channel through which cooling water flows at an interface with the second side of the first cooling block; a fixing step of placing and fixing the second cooling block on the second side of the prepared first cooling block with a clamp; a combining step of combining and fixing the first cooling block and the second cooling block by heating and welding the first cooling block and the second cooling block; and a cooling step of selectively quenching only the second cooling block from the heated first cooling block and the second cooling block.

[0022] The preparation step prepares an aluminum-based alloy for the first cooling block and the second cooling block. The bonding step heats the first cooling block and the second cooling block to above a solution treatment temperature of the aluminum-based alloy, and then welds the first cooling block and the second cooling block.

[0023] The method further includes a post-heat treatment step of performing heat treatment by heating the first cooling block and the second cooling block after the cooling step.

[0024] The fixture used in the fixing step is divided into a first fixture and a second fixture. The first fixture supports the side opposite to the side of the outside of the first cooling block facing the second cooling block. The second fixture supports the side opposite to the side of the outside of the second cooling block facing the first cooling block. The shape prepared by the first fixture corresponds to the side opposite to the side of the outside of the first cooling block facing the second cooling block, and the shape prepared by the second fixture covers and partially exposes the side opposite to the side of the outside of the second cooling block facing the first cooling block. The cooling step selectively quenches only the second cooling block by contacting cooling water or cooling oil with the exposed area of ​​the second cooling block exposed by the second fixture.

[0025] In the cooling step, a discharge portion for discharging cooling water or cooling oil is provided around the second jig.

[0026] The third jig forms a cooling channel through which cooling water or cooling oil flows, and covers the exposed area of ​​the second cooling block. The third jig is further provided, and then only the second cooling block is selectively quenched by guiding cooling water or cooling oil to the cooling channel.

[0027] According to an embodiment of the present disclosure, the first cooling block in contact with the battery module and the second cooling block forming the cooling channel are combined by brazing. Then only the second cooling block is quenched. Therefore, it has the following effect: the first cooling block maintains a relatively high thermal conductivity, and the second cooling block maintains a high strength, thereby improving performance.

[0028] In addition, the performance is improved by heat treatment, so the thickness of the entire cooling block can be reduced. Therefore, not only the weight can be reduced, but also the cooling performance of the cooling block can be improved.

[0029] In addition, since heat treatment such as quenching can be performed immediately after bonding using a brazing furnace for brazing, advantages in manufacturing cost can be obtained. In addition, since heat treatment can be selectively performed only on necessary areas of the cooling block, which are conventionally difficult to heat treat due to shape restrictions, an effect of improving desired characteristics of each area can be expected. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The above and other aspects, features and advantages of the present disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0031] Figure 1 is an exploded perspective view showing a general cooling block for a battery module.

[0032] Figure 2 is a cross-sectional view showing a general cooling block for a battery module.

[0033] Figure 3is a view showing a state when a jig is fastened to manufacture a cooling block for a battery module according to an embodiment of the present disclosure; and

[0034] Figure 4 and Figure 5 is a view showing a state when a jig is fastened to manufacture a cooling block for a battery module according to another embodiment of the present disclosure. DETAILED DESCRIPTION

[0035] Hereinafter, embodiments of the present disclosure are described in detail with reference to the accompanying drawings. However, the present disclosure is not limited to the following embodiments and can be implemented in various ways different from each other. Embodiments are provided to complete the present disclosure and fully inform the ordinary technicians in the field of the scope of the present disclosure. In the accompanying drawings, the same components are given the same reference numerals.

[0036] Figure 1 is an exploded perspective view showing a conventional cooling block for a battery module, and Figure 2 is a cross-sectional view showing a general cooling block for a battery module.

[0037] like Figure 1 As shown, the cooling block for a battery module according to the present disclosure (similar to the cooling block for a battery module in the prior art) includes a first cooling block 10, which contacts the battery module 1 on a first side; and a second cooling block 20, which is combined with the second side of the first cooling block 10 and forms a cooling channel 21. Cooling water flows through the cooling channel 21 at the interface with the second side of the first cooling block 10.

[0038] However, the cooling block for the battery module according to the present disclosure is characterized by Figure 1 According to the present disclosure, the first cooling block 10 and the second cooling block 20 are made of the same metal-based material, but the thermal conductivity and strength of the first cooling block 10 are different from those of the second cooling block 20.

[0039] The first cooling block 10 is in contact with the battery module (ie, a heat generating body) on a first side and is in contact with cooling water on a second side, thereby dissipating heat generated from the battery module 1 .

[0040] The first cooling block 10 is formed in a wide plate shape so that all battery modules 1 can contact the first cooling block 10, and so that all battery modules 1 are located on the first side, because cooling water leakage may occur. The first cooling block 10 is formed thicker than the second cooling block to support the battery module 1 and improve the collision performance. The first cooling block 10 is not limited to a specific shape as long as all battery modules 1 can contact the first side and the second cooling block 20 can be combined to the second side. For example, as shown in the figure, although the first cooling block 10 can be formed in a flat plate shape, a groove for accommodating the battery module 1 or a protrusion around the area where the battery module 1 is accommodated can be formed on the first side of the first cooling block 10. This is to make the battery module 1 in a stable posture and to improve the heat transfer efficiency by increasing the contact area between the battery module 1 and the first cooling module 10. In addition, a groove or protrusion may be formed on the second side of the first cooling block 10 so as to improve the heat transfer efficiency by increasing the contact area between the first cooling block 10 and the cooling water. In addition, the first cooling block 10 may be partially bent while maintaining the entire wide plate shape to achieve the functions of the above-mentioned grooves and protrusions.

[0041] The first cooling block 10 requires high thermal conductivity to dissipate heat from the battery module 1. However, when a heat treatment is performed, the thermal conductivity may be deteriorated due to the heat treatment.

[0042] The second cooling block 20 is coupled to the first cooling block 10 , thereby providing a space in which cooling water flows.

[0043] Therefore, the second cooling block 20 has a cooling channel 21 having a U-shaped cross section. The cooling channel 21 is on the surface, thereby forming a space for cooling water to flow at the interface by contacting the second side of the first cooling block 10. Obviously, the cross-sectional shape of the cooling channel 21 is not limited to the U-shape, and can be changed to various shapes that can form a space in which cooling water can flow. The second cooling block 20 is formed to be thinner than the first cooling block 10 to prevent the thickness of the entire layout of the cooling block from increasing and reducing the material. However, the higher the strength, the more conducive the second block 20 is to prevent deformation caused by the pressure of the cooling water flowing through the cooling channel 21.

[0044] The first cooling block 10 and the second cooling block 20 are made of the same metal-based material to be combined by welding such as brazing. For example, the first cooling block 10 and the second cooling block 20 may be made of aluminum or an aluminum alloy having high thermal conductivity.

[0045] Although the first cooling block 10 and the second cooling block 20 are made of the same metal-based material, as described above, depending on the function, the thermal conductivity of the first cooling block 10 may be higher than the second cooling block 20, and the strength of the second cooling block 20 may be higher than the first cooling block 10.

[0046] Generally, the properties of heat-treated aluminum alloys before and after heat treatment are shown in Table 1 below.

[0047] [Table 1]

[0048]

[0049] As shown in Table 1, when the heat treatment tempering is T6 (artificial aging), the ordinary heat-treated aluminum alloy is improved in yield strength and tensile strength, but reduced in thermal conductivity, compared with the case where the heat treatment tempering is not performed to O. The reason is that the heat treatment of the aluminum alloy first prepares a supersaturated solid solution by rapidly cooling the aluminum alloy and forming unstable reinforcing particles (post-heat treatment) during the aging process, thereby improving the strength. The reinforcing particles are a factor that improves the strength but interferes with the thermal conductivity.

[0050] The present disclosure utilizes the characteristic that the properties of the aluminum alloy are changed before and after heat treatment. According to the present disclosure, in order to give the first cooling block 10 and the second cooling block 20 different thermal conductivity and strength, the first cooling block 10 and the second cooling block 20 are heated and combined by welding. However, the quenching is then only partially applied to the second cooling block 20. Brazing can be used for welding. The type of welding is not limited to brazing, and according to the shape of the first cooling block 10 and the second cooling block 20 and the type of material, various types of welding that can combine the first cooling block 10 and the second cooling block 20 while heating the first cooling block 10 and the second cooling block 20 can be applied.

[0051] A method of manufacturing the cooling block for a battery module having the above-described configuration according to an embodiment of the present disclosure is described with reference to the accompanying drawings.

[0052] Figure 3 is a view showing a state when a jig is fastened to manufacture a cooling block for a battery module according to an embodiment of the present disclosure. Figure 4 and Figure 5 is a view showing a state when a jig is fastened to manufacture a cooling block for a battery module according to another embodiment of the present disclosure.

[0053] The method for manufacturing a cooling block for a battery module according to an embodiment of the present disclosure includes: a preparation step, preparing a first cooling block 10 and a second cooling block 20, the first cooling block 10 is in contact with the battery module 1 on the first side, and the second cooling block 20 is combined with the second side of the first cooling block and forms a cooling channel 21 through which cooling water flows at the interface with the second side of the first cooling block 10. The method includes a fixing step, placing and fixing the second cooling block 20 on the second side of the prepared first cooling block 10 with a clamp. The method includes a combining step, combining the fixed first cooling block 10 and the second cooling block 20 by heating and welding the first cooling block 10 and the second cooling block 20. The method includes a cooling step, selectively quenching only the second cooling block 20 from the first cooling block 10 and the second cooling block 20.

[0054] The method includes a post-heat treatment step of performing heat treatment by heating the first cooling block 10 and the second cooling block 20 after the cooling step.

[0055] The preparation step is a step of preparing the first cooling block 10 and the second cooling block 20 constituting the cooling block, and the same aluminum alloy for the first cooling block 10 and the second cooling block 20 is prepared. A heat-treated aluminum alloy that improves yield strength and tensile strength by heat treatment can be prepared for the first cooling block 10 and the second cooling block 20. For example, the first cooling block 10 and the second cooling block 20 can be manufactured using aluminum-copper-based, aluminum-magnesium-silicon-based, and aluminum-zinc-based aluminum. The first cooling block 10 and the second cooling block 20 can be manufactured using any aluminum alloy selected from the proposed aluminum-copper-based, aluminum-magnesium-silicon-based, and aluminum-zinc-based aluminum, or can be manufactured using an aluminum alloy selected from aluminum-copper-based, aluminum-magnesium-silicon-based, and aluminum-zinc-based aluminum in a different manner.

[0056] The fixing step is a step of disposing and fixing the second cooling block 20 on the second side of the first cooling block 10 so as to combine the prepared first cooling block 10 and second cooling block 20 by brazing, and the fixing step uses a jig to fix the cooling blocks.

[0057] The jig used in this step is divided into a first jig 100 and a second jig 200. The first jig 100 supports the first cooling block 10 on the side opposite to the side of the outer side of the first cooling block 10 facing the second cooling block 20. The second jig 20 supports the second cooling block 20 on the side opposite to the side of the outer side of the second cooling block 20 facing the first cooling block 10.

[0058] The first clamp 100 is formed in a plate shape to prevent the first cooling block 10 from being twisted and deformed, so that it can cover the entire first side surface of the first cooling block 10 to support the first cooling block 10 .

[0059] The second jig 200 is prepared to cover and partially expose one side of the outer side of the second cooling block 20 opposite to the side facing the first cooling block 10. The second jig 200 may be divided into several parts to form an area 20a (hereinafter referred to as "exposed area") exposed from the outer side of the second cooling block 20. The exposed area 20a formed by the second jig 200 is an area that is directly contacted by cooling water or cooling oil as a cooling medium in the next cooling step.

[0060] Therefore, the first jig 100 prevents deformation of the first cooling block 10 and the second cooling block 20. The second jig 200 fixes the first cooling block 10 and the second cooling block 20 while forming the exposed area 20a.

[0061] The bonding step is a step of bonding the first cooling block 10 and the second cooling block 20 by heating through brazing, and the first cooling block 10 and the second cooling block 20 fixed by the first clamp 100 and the second clamp 200 are placed in a brazing furnace and then heated therein. The aluminum alloy used to manufacture the first cooling block 10 and the second cooling block 20 is heated to a temperature above the solution treatment temperature. For example, the first cooling block 10 and the second cooling block 20 are heated to a level of 600°C ± 20°C (1110°F ± 36°F).

[0062] After being sufficiently heated, the first cooling block 10 and the second cooling block 20 are bonded by brazing.

[0063] The cooling step selectively or partially quenches only the second cooling block of the first cooling block 10 and the second cooling block 20 that have been heated in the bonding step. By bringing cooling water or cooling oil into contact with the exposed area 20a of the second cooling block 20 formed by the second jig 200, only the second cooling block 20 is selectively or partially quenched.

[0064] The cooling step may be performed in the brazing furnace where the bonding step is performed, or may be performed outside the brazing furnace. Depending on the type of process, the location where the cooling step is performed may be varied in various ways, such as whether the cooling step and the bonding step are performed in a single chamber like a brazing furnace, or whether these steps are performed in a continuous furnace.

[0065] Furthermore, the method of selectively or partially quenching only the second cooling block 20 may be implemented in various ways.

[0066] For example, Figure 4 As shown, a discharge unit 300 for discharging cooling water or cooling oil may be provided around the second jig 200 .

[0067] By providing the discharge portion or the discharge unit 300 around the second jig 200 , the cooling water or cooling oil supplied to the exposed area 20 a of the second cooling block 20 may be discharged without directly contacting the first cooling block 10 and the first jig 100 .

[0068] To this end, flow grooves (not shown) along which cooling water or cooling oil can flow in a specific direction may be formed on a surface of the second jig 200 and a surface of the discharge portion or unit 300 .

[0069] On the other hand, Figure 5 As shown, a third fixture 310 may be further provided. The third fixture 310 has a cooling channel 311 through which cooling water or cooling oil flows and covers the exposed area 20 a of the second cooling block 20 .

[0070] Therefore, only the exposed area 20a of the second cooling block 20 may be cooled by guiding cooling water or cooling oil through the cooling channel 311 formed on the third jig 310. In addition, the cooling water or cooling oil may be guided without directly contacting the first cooling block 10 and the first jig 100.

[0071] In addition, in order to selectively quench only the second cooling block 20, the first cooling block 10 may be arranged at an upper position and the second cooling block 20 may be arranged at a lower position, which is similar to Figure 4 The arrangement of the first cooling block 10 and the second cooling block 20 is shown to be reversed. Then, cooling water or cooling oil may be sprayed to the exposed area 20a of the second cooling block 20 from below the second cooling block 20. Therefore, the cooling water or cooling oil can only flow downward by its own weight without contacting the first cooling block 10 even without a separate unit for discharging the cooling water or cooling oil.

[0072] The post-heat treatment step is a T6 heat treatment (artificial aging heat treatment), which is performed to improve the performance of the first cooling block 10 and the second cooling block 20. The post-heat treatment step heats the first cooling block 10 and the second cooling block 20 (forced to be selectively cooled) at a T6 heat treatment temperature (artificial aging heat treatment temperature), and then cools them with air. The T6 heat treatment temperature can be determined based on the material of the first cooling block 10 and the second cooling block 20. For example, since the first cooling block 10 and the second cooling block 20 are made of aluminum or an aluminum alloy with high thermal conductivity, they will be heated in a temperature range of 160 to 220°C (320 to 430°F) according to the composition of the material, and then cooled by air.

[0073] As described above, by performing the post-heat treatment, the residual stress generated by the first cooling block 10 and the second cooling block 20 being exposed to high temperature during welding is removed, and the quenched second cooling block 20 is artificially aged.

[0074] By selectively or partially quenching the second cooling block 20 through the above steps, the first cooling block 10 can maintain a state with excellent thermal conductivity, such as the case of tempering 0, that is, the state without heat treatment in Table 1. In addition, the second cooling block 20 is similar to the state of heat treatment (that is, the case of T6 tempering), and can maintain a state with excellent yield strength and tensile strength.

[0075] Although the present disclosure has been described above with reference to the accompanying drawings and embodiments, the present disclosure is not limited thereto but is defined by the appended claims. Therefore, those skilled in the art may change and modify the present disclosure in various ways without departing from the spirit of the claims.

Claims

1. A cooling block for a battery module, the cooling block include: a first cooling block in contact with the battery module on a first side; and A second cooling block is coupled to the second side of the first cooling block and forms a cooling channel through which cooling water flows at an interface with the second side of the first cooling block. Wherein, the first cooling block and the second cooling block are made of the same aluminum-based alloy, The thermal conductivity and strength of the first cooling block are different from the thermal conductivity and strength of the second cooling block, and Wherein, the first cooling block and the second cooling block are heated and bonded by welding, and then only the second cooling block is partially quenched.

2. The cooling block according to claim 1, in, The thermal conductivity of the first cooling block is higher than the thermal conductivity of the second cooling block.

3. The cooling block according to claim 1, in, The second cooling block has a strength greater than that of the first cooling block.

4. A method for manufacturing a cooling block for a battery module, the method The following steps are involved: A preparation step, using the same aluminum-based alloy to prepare a first cooling block and a second cooling block, wherein the first cooling block is configured to contact the battery module on a first side of the first cooling block, and the second cooling block is configured to be coupled to a second side of the first cooling block and form a cooling channel through which cooling water can flow at an interface with the second side of the first cooling block; A fixing step, placing and fixing the second cooling block on the second side of the prepared first cooling block using a clamp; a combining step of combining the fixed first cooling block and the second cooling block by heating and welding the first cooling block and the second cooling block; as well as The cooling step selectively quenches only the second cooling block.

5. The method according to claim 4, in, The preparing step includes preparing an aluminum-based alloy for the first cooling block and the second cooling block, and The bonding step includes heating the first cooling block and the second cooling block to above a solution treatment temperature of the aluminum-based alloy, and then welding the first cooling block and the second cooling block. 6 . The method according to claim 4 , further comprising a post-heat treatment step including performing heat treatment by heating the first cooling block and the second cooling block after the cooling step.

7. The method according to claim 4, in, The jig used in the fixing step is divided into a first jig and a second jig, the first jig supporting a side of the first cooling block opposite to a side of an outer side of the first cooling block facing the second cooling block, and the second jig supporting a side of the second cooling block opposite to a side of an outer side of the second cooling block facing the first cooling block, wherein the shape prepared by the first fixture corresponds to a side opposite to a side of the outer side of the first cooling block facing the second cooling block, and the shape prepared by the second fixture covers and partially exposes a side opposite to a side of the outer side of the second cooling block facing the first cooling block, and The cooling step selectively quenches only the second cooling block by bringing cooling water or cooling oil into contact with an exposed area of ​​the second cooling block exposed by the second jig.

8. The method according to claim 7, in, In the cooling step, a discharge portion discharges the cooling water or cooling oil and is provided around the second jig.

9. The method according to claim 7, in, A third jig is also provided, which has a cooling channel through which cooling water or cooling oil flows and covers the exposed area of ​​the second cooling block, and then selectively quenches only the second cooling block by guiding the cooling water or cooling oil to the cooling channel.

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