Battery cell thermal management structure

Abstract

A thermal management structure for a battery cell according to an embodiment of the present invention includes a plurality of repeatedly arranged battery cells, a cell cooling unit heat-transferably connected to one side of the battery cells and cooling or heating the battery cells when necessary, and a hybrid PCM unit made of different types of phase change materials (PCMs) disposed between the battery cells to absorb heat generated in the battery cells and disposed in a plurality of divided regions divided into shapes corresponding to a temperature gradient pattern of the battery cells.

Description

[Technical field]

[0001] The present invention relates to a thermal management structure for a battery cell, and more particularly, to a thermal management structure for a battery cell that can reduce temperature deviation due to the position of the battery cell and improve the cooling performance and heating performance of the battery cell by applying a hybrid PCM part formed of different types of phase change materials to the battery cell. [Background technology]

[0002] Generally, batteries are widely used in electrical devices that cannot be connected by wires, such as portable electronic devices, mobile communication terminals, electric vehicles, etc. As a result, research and development of batteries has been intensified with the trend of expanding the battery market, but the reality is that accidents such as battery fires or explosions still occur frequently.

[0003] The above-mentioned battery fires and explosions occur for various reasons, such as damage due to impact, design errors, short circuits, and harsh usage environments, and it remains difficult to completely prevent them.

[0004] In recent years, there is a trend for electric vehicles to rapidly spread in popularity. A high-capacity battery pack is used in a typical electric vehicle. In the battery pack of such an electric vehicle, while it is important to increase the performance and capacity, it is also very important to prevent damage to human life and property due to fire and explosion. For this reason, research and development has been actively conducted in recent years to develop a battery pack that has all of high capacity, high efficiency, and high safety.

[0005] In particular, the aim is to increase charging efficiency and improve power consumption by delaying the temperature rise that occurs in the battery cells of the battery pack under fast charging and harsh driving conditions of electric vehicles, and further, technologies are being continuously researched and developed to reduce the risk of fire and explosion in the battery module due to abnormal phenomena in the battery cells caused by temperature rise.In recent years, attempts have been made to improve the cooling performance of battery cells by using phase change materials (PCMs), which absorb more heat during the phase change process.

[0006] Meanwhile, in the past, a method of managing the heat of a battery cell by disposing a cooling plate under the battery cell has been widely used, but this conventional method has problems in that a very large temperature gradient occurs in the battery cell due to the temperature difference between the inlet and outlet of the coolant supplied to the cooling plate, and a temperature difference also occurs between the upper and lower parts of the battery cell due to the cooling plate located at the lower part. Such a temperature gradient in the battery cell leads to a difference in the degree of deterioration inside the battery cell, and if the battery cell is continuously operated in a state where the temperature gradient in the battery cell is large, there is a high possibility that a serious problem will occur in the stability and lifespan of the battery cell.

[0007] Therefore, a technology of applying a separate heat pipe or cooling system has been developed to solve the temperature difference between each battery cell or between the upper and lower parts of each battery cell, but this has limitations in that the structure and control method become complicated and the overall weight increases significantly.

[0008] This invention relates to technology developed by the Korea University Industry-Academia Collaboration Team through the research project "Optimization of Thermal Management System for Next-Generation High Energy Density Batteries Using Composite Phase Change Heat Transfer Package" (Project No.: 1711162708, Research Period: 2019.03.01~2023.02.28) funded by the Ministry of Science, ICT and Technology. Summary of the Invention [Problem to be solved by the invention]

[0009] An embodiment of the present invention provides a thermal management structure for a battery cell that can reduce temperature deviation of the battery cell by applying a hybrid PCM part formed of different types of phase change materials to the battery cell, thereby improving the cooling performance of the battery cell and increasing the stability and lifespan of the battery cell.

[0010] In addition, the embodiments of the present invention provide a heat management structure for a battery cell that can act as a heat buffer to absorb heat generated by a battery cell using latent heat of a hybrid PCM during fast charging, minimize temperature deviation of the battery cell during cooling or heating, and promote improvement of the battery cell life and ensuring operational stability. [Means for solving the problem]

[0011] According to one embodiment of the present invention, there is provided a thermal management structure for a battery cell, the thermal management structure including: a plurality of repeatedly arranged battery cells; a cell cooling unit connected to one side of the battery cell for thermal conduction and cooling the battery cell or heating the battery cell when necessary; and a hybrid PCM unit formed of different types of phase change materials (PCMs) arranged between the battery cells to absorb heat generated in the battery cells and arranged in a plurality of divided regions divided into shapes corresponding to a temperature gradient pattern of the battery cells.

[0012] Preferably, the hybrid PCM unit may be divided into a plurality of divided regions according to a temperature gradient pattern of the battery cell, and the phase change materials disposed in each divided region may have different thermal conductivities.

[0013] For example, as the temperature of the battery cell corresponding to each divided region increases, a phase change material having a relatively high thermal conductivity among the phase change materials may be disposed in each divided region, and as the temperature of the battery cell corresponding to each divided region decreases, a phase change material having a relatively low thermal conductivity among the phase change materials may be disposed in each divided region.

[0014] Preferably, the hybrid PCM part may be provided with a reference phase change material formed only of a pure phase change material, and a composite phase change material formed by combining the reference phase change material with a heat transfer material having a higher thermal conductivity than the reference phase change material.

[0015] The thermal conductivity of the composite phase change material can be changed by adjusting the content of the heat transfer material synthesized in the reference phase change material.

[0016] The heat transfer material may include at least one of metal foam, carbon-based materials, metal fins, and nano-materials, which have a higher thermal conductivity than the reference phase change material.

[0017] Preferably, the thermal management structure of a battery cell according to one embodiment of the present invention may further include a fin member made of a metal material that is in thermally conductive contact with one side of the hybrid PCM section, has one side connected to the cell cooling section, and serves as a heat transfer passage between the hybrid PCM section and the cell cooling section.

[0018] Preferably, the thermal management structure of a battery cell according to one embodiment of the present invention may further include a heat transfer sheet attached to one side of the fin member in contact with the hybrid PCM portion and made of a material having a higher thermal conductivity than the fin member to enhance the heat transfer performance of the fin member.

[0019] The heat transfer sheet may be made of a graphite material. Effect of the Invention

[0020] The thermal management structure of a battery cell according to an embodiment of the present invention can reduce temperature deviation due to the position of the battery cell by applying a hybrid PCM part formed of different types of phase change materials to the battery cell, thereby improving the cooling performance of the battery cell and increasing the stability and lifespan of the battery cell.

[0021] In addition, the thermal management structure of the battery cell according to the embodiment of the present invention absorbs the sudden heat generated in the battery cell by using the latent heat of the hybrid PCM when the battery cell is fast charged, so that the hybrid PCM can act as a thermal buffer, and when the battery cell is cooled or heated, the hybrid PCM can minimize the temperature deviation at each position of the battery cell, thereby improving the lifespan of the battery cell and ensuring the operational stability of the battery cell.

[0022] In addition, the thermal management structure of the battery cell according to the embodiment of the present invention has a structure in which a hybrid PCM section, a heat transfer sheet, and a fin member are respectively arranged between each battery cell, so that heat generated in each battery cell can be smoothly transferred to the cell cooling section via the hybrid PCM section, the heat transfer sheet, and the fin member, and when the battery cell is heated, the heat transferred from the cell cooling section can be easily transferred to each battery cell.

[0023] In addition, the thermal management structure of the battery cell according to an embodiment of the present invention is a structure in which a hybrid PCM part is divided into a plurality of divided regions according to a temperature gradient pattern depending on the position of the battery cell, and the divided regions are formed of phase change materials having different thermal conductivities. Therefore, the temperature gradient depending on the position of the battery cell can be appropriately eliminated by the hybrid PCM part formed of phase change materials having different thermal conductivities, and as a result, the temperature deviation of the battery cell can be reduced and the performance and stability of the battery cell can be improved.

[0024] In addition, since the thermal management structure of the battery cell according to an embodiment of the present invention has a structure in which a thermal conductive sheet having high thermal conductivity is arranged between the hybrid PCM section and the fin member, the efficiency of heat transfer between the hybrid PCM section and the cell cooling section can be improved, and heat transfer to a specific portion of the battery cell far away from the cell cooling section can be stably performed, so that the temperature deviation of the battery cell can be reduced by the hybrid PCM section and the thermal conductive sheet.

[0025] In addition, the thermal management structure of the battery cell according to the embodiment of the present invention manufactures the hybrid PCM part in a thin pouch shape and the heat transfer sheet in a thin film shape, so that even when the hybrid PCM part and the heat transfer sheet are disposed between each battery cell, the weight and size of the battery cell are not significantly increased, and the battery cell can be manufactured compactly.

[0026] In addition, the thermal management structure of the battery cell according to the embodiment of the present invention reduces the temperature deviation of the battery cell by the hybrid PCM part and the thermal conductive sheet, thereby making it possible to prevent an abnormal increase in temperature of a specific part of the battery cell, and effectively prevent fires and explosions of the battery cell due to an abnormal increase in temperature of the battery cell. [Brief description of the drawings]

[0027] [Figure 1] 1 is a schematic diagram illustrating a thermal management structure of a battery cell according to an embodiment of the present invention. [Diagram 2] 2 is an exploded perspective view of a main part of the thermal management structure of the battery cell shown in FIG. 1. [Diagram 3] 3 is a diagram showing a heat transfer path due to cooling and heating of the battery cell shown in FIG. 2. [Figure 4] 3 is a diagram showing another example of the thermal management structure of the battery cell shown in FIG. 2. [Diagram 5]FIG. 5 is a diagram showing a modification of the hybrid PCM unit shown in FIGS. 2 and 4. [Figure 6] 2 is a graph showing a maximum temperature and a maximum temperature deviation of the battery cell shown in FIG. 1 during rapid charging. [Figure 7] 2 is a diagram showing maximum and minimum temperatures of the battery cell shown in FIG. 1 during temperature rise. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] Hereinafter, the embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited or restricted by the embodiments. The same reference numerals in the drawings indicate the same elements.

[0029] FIG. 1 is a schematic diagram of a thermal management structure 100 for a battery cell according to one embodiment of the present invention, FIG. 2 is an exploded perspective view of the main parts of the thermal management structure 100 for a battery cell shown in FIG. 1, FIG. 3 is a diagram showing a heat transfer path due to cooling and heating of the battery cell 110 shown in FIG. 2, FIG. 4 is a diagram showing another example of the thermal management structure 100 for a battery cell shown in FIG. 2, and FIG. 5 is a diagram showing a modified example of the hybrid PCM section 140 shown in FIGS. 2 and 4.

[0030] 1 to 4, a thermal management structure 100 for a battery cell according to an embodiment of the present invention may include a battery cell 110, a cell cooling portion 120, a fin member 130, a hybrid PCM portion 140, and a heat transfer sheet 150.

[0031] In the thermal management structure 100 for a battery cell according to the present embodiment, the battery cell 110 is described as being formed as a rectangular thin plate structure, but is not limited thereto and may be formed as a structure of other shapes. In particular, in the present embodiment, for the convenience of explanation of the thermal management structure 100 for a battery cell, the front-rear direction, the up-down direction, and the left-right direction are described in a preset state.

[0032] For example, the battery cells 110 may be arranged in a standing structure on the upper side of the cell cooling unit 120, and a plurality of the battery cells 110 may be arranged alternately in the front-rear direction. The cell cooling unit 120 may be connected to a lower portion of the battery cell 110, and the cell tab 112 of the battery cell 110 may be arranged on an upper portion of the battery cell 110.

[0033] 1 to 3, a plurality of battery cells 110 of the present invention may be repeatedly arranged. The battery cells 110 are components that perform charging and discharging of electricity and may be accommodated inside a battery module housing (not shown). In general, the battery cells 110 may generate heat during charging and discharging, causing the temperature to increase.

[0034] Here, the battery cells 110 may be arranged such that a plurality of the battery cells 110 are repeatedly and closely attached to each other along the front-rear direction. A cell tab 112 may be extended upwardly from an upper portion of the battery cell 110. For reference, a lower portion of the battery cell 110 may be connected to an upper surface of the cell cooling unit 120 so as to be capable of conducting heat.

[0035] 1, the cell cooling unit 120 of the present embodiment may be connected to a lower portion of the battery cell 110 in a heat-transferable manner so as to cool the battery cell 110 or heat it up as necessary. That is, the cell cooling unit 120 may prevent overheating of the battery cell 110 and a resulting decrease in efficiency by cooling the battery cell 110 when the battery module is in use, or may preheat the battery cell 110 by heating the battery cell 110 in a very cold environment or before actual use.

[0036] For example, the cell cooling portion 120 may include a cold plate 122 and a heat sink 124 .

[0037] The cooling plate 122 is configured to be connected to the lower part of the battery cell 110, and can transfer heat generated in the battery cell 110 to the heat sink 124 when cooling the battery cell 110, and can transfer heat from the heat sink 124 to the battery cell 110 when the temperature of the battery cell 110 increases. For this purpose, the cooling plate 122 can be formed of a metal material having high thermal conductivity. For reference, a gap filler having excellent thermal conductivity can be disposed between the cooling plate 122 and the lower part of the battery cell 110 to eliminate a gap between the cooling plate 122 and the battery cell 110.

[0038] When the battery cells 110 are cooled, the heat sink 124 may absorb heat transferred from the battery cells 110 to the cooling plate 122 and then release the heat to the outside, and when the battery cells 110 are heated, the heat sink 124 may provide the heat to be transferred to the battery cells 110 to the cooling plate 122. To this end, the heat sink 124 may be disposed on the lower surface of the cooling plate 122 to be capable of transferring heat.

[0039] For example, the heat sink 124 may cool or heat the cooling plate 122 using cooling water W flowing in from the outside. In this case, the cooling water W may be cooled or heated to a desired temperature through a separate heat pump system disposed outside the battery module.

[0040] 1 to 3, the fin member 130 of this embodiment may serve as a heat transfer path between the hybrid PCM unit 140 and the cell cooling unit 120. The fin member 130 may be made of a metal material having high thermal conductivity, and in this embodiment, the fin member 130 is made of an aluminum material. Here, the fin member 130 may be in contact with one side of the hybrid PCM unit 140 so as to be capable of transferring heat. A lower portion of the fin member 130 may be placed on the cooling plate 122 of the cell cooling unit 120 so as to be capable of transferring heat.

[0041] For example, the fin member 130 may include a fin panel 132 that contacts one side of the hybrid PCM section 140, and a fin mounting portion 134 that is provided in a flange shape at a lower end of the fin panel 132 and placed on the cooling plate 122. In this case, the contact surface of the fin panel 132 may be provided in a shape that corresponds to one side of the hybrid PCM section 140, and the fin mounting portion 134 may be connected to the cooling plate 122 so as to be capable of conducting heat.

[0042] 1 to 3, the hybrid PCM unit 140 of the present embodiment may be disposed between a plurality of battery cells to absorb heat generated in the battery cells 110. The hybrid PCM unit 140 may be provided in a thin pouch structure that contains various types of phase change materials 142, 144. Therefore, even when the hybrid PCM unit 140 is disposed between each battery cell 110, the size and weight of the battery module do not increase significantly, and the battery module may be formed compactly and simply.

[0043] In this case, the hybrid PCM unit 140 may be formed with a plurality of divided regions A and B each divided into a shape corresponding to the temperature gradient pattern of the battery cell 110. The positions and number of the divided regions A and B of the hybrid PCM unit 140 may be determined according to the temperature gradient pattern of the battery cell 110, and the divided regions A and B may be formed of different types of phase change materials (PCMs) 142 and 144.

[0044] Specifically, the hybrid PCM unit 140 may be divided into a plurality of divided regions A and B according to a temperature gradient pattern of the battery cell 110. In this case, each of the phase change materials 142 and 144 disposed in each of the divided regions A and B may have different thermal conductivities according to the temperature gradient of the battery cell 110.

[0045] That is, the composite phase change material 144 having relatively high thermal conductivity among the phase change materials 142, 144 may be disposed in the first division region A where the temperature of the battery cells 110 is relatively high among the division regions A and B. Meanwhile, the reference phase change material 142 having relatively low thermal conductivity among the phase change materials 142, 144 may be disposed in the second division region B where the temperature of the battery cells 110 is relatively low among the division regions A and B.

[0046] Therefore, a high temperature region of the battery cell 110 may be cooled or heated faster than a low temperature region of the battery cell 110 through the composite phase change material 144 of the first divided region A. As described above, since the temperature deviation of the battery cell 110 is compensated for by the difference in thermal conductivity of the phase change materials 142, 144 of the hybrid PCM unit 140, the entire battery cell 110 may be cooled or heated without temperature deviation through the thermal management structure 100 of this embodiment.

[0047] For example, the hybrid PCM section 140 may be provided with a reference phase change material 142 formed only of a pure phase change material, and a composite phase change material 144 formed with a higher thermal conductivity than the reference phase change material 142 by combining the reference phase change material 142 with a heat transfer material (not shown) having a higher thermal conductivity than the reference phase change material 142.

[0048] Here, the reference phase change material 142 may be made of only a paraffin-based material having low thermal conductivity.

[0049] The composite phase change material 144 may change thermal conductivity by adjusting the content of the heat transfer material synthesized in the reference phase change material 142. The heat transfer material may include at least one of foam metal, carbon-based material, metal fin, nano material, and paraffin substitute material, which have higher thermal conductivity than the reference phase change material 142.

[0050] For reference, the reference phase change material 142 and the composite phase change material 144 are not limited to the above compositions, but may be fabricated with various compositions depending on the design conditions and circumstances for the thermal management structure 100 of the battery cell.

[0051] 2 and 3, the heat transfer sheet 150 of this embodiment may be attached to one surface of the fin member 130 that contacts the hybrid PCM unit 140. The heat transfer sheet 150 may be made of a material having a higher thermal conductivity than the fin member 130 to further enhance the heat transfer performance of the fin member 130. As an example, the heat transfer sheet 150 may be made of a graphite material.

[0052] 4 illustrates another example of a thermal management structure 100 for a battery cell according to an embodiment of the present invention. That is, in the thermal management structure 100 for a battery cell illustrated in FIG 4, the hybrid PCM unit 140 may be divided into three divided regions A, B, and C, and as a result, the hybrid PCM unit 140 may be formed of three phase change materials 142, 144, and 146 having different thermal conductivities.

[0053] In this case, the first divided region A of the battery cell 110 having the highest temperature may be formed of the first composite phase change material 146 having the highest relative thermal conductivity, the second divided region B of the battery cell 110 having the second highest temperature may be formed of the second composite phase change material 144 having the second highest relative thermal conductivity, and the third divided region C of the battery cell 110 having the lowest temperature may be formed of the reference phase change material 142 having the lowest relative thermal conductivity. Therefore, the thermal management structure 100 of a battery cell shown in FIG. 4 may perform more precise thermal management of the battery cell 110 than that of FIG. 2.

[0054] Meanwhile, FIG. 5 shows modified examples of the hybrid PCM unit 140 having divided regions A, B, and C of various shapes. The hybrid PCM section 140 shown in FIG. 5(a) shows a state in which three divided regions A, B, and C are formed at an angle, the hybrid PCM section 140 shown in FIG. 5(b) shows a state in which one of the two divided regions A and B (e.g., the first divided region A) is formed in the center, the hybrid PCM section 140 shown in FIG. 5(c) shows a state in which one of the three divided regions A, B, and C (e.g., the first divided region A) is formed at the top and the other of the three divided regions A, B, and C (e.g., the second divided region B) is formed in the center, and the hybrid PCM section 140 shown in FIG. 5(d) shows a state in which one of the three divided regions A, B, and C (e.g., the first divided region A) is formed at the top and the other of the three divided regions A, B, and C (e.g., the second divided region B) is formed multiple times in the center.

[0055] However, the present invention is not limited thereto. As described above, the divided regions A, B, and C of the hybrid PCM unit 140 of the present embodiment may be variously set and changed according to the temperature gradient pattern of the battery cells 110.

[0056] Hereinafter, the operation and effects of the thermal management structure 100 for a battery cell according to an embodiment of the present invention configured as above will be described.

[0057] 3, when the battery cell 110 is cooled, heat F1 and F2 generated in the battery cell 110 is transferred to the heat transfer sheet 150 through the hybrid PCM unit 140, and then transferred to the cooling plate 122 of the cell cooling unit 120 along the heat transfer sheet 150 and the fin member 130. The heat F1 and F2 transferred to the cooling plate 122 of the cell cooling unit 120 is discharged to the outside through the heat sink 124.

[0058] At this time, heat F1 is transferred very quickly through the composite phase change material 144 provided in the first division region A of the hybrid PCM unit 140, and heat F2 is transferred relatively slowly through the reference phase change material 142 provided in the second division region B of the hybrid PCM unit 140. Therefore, since the amount of heat transferred through the composite phase change material 144 is greater than the amount of heat transferred through the reference phase change material 142, a greater cooling effect can be obtained in the area of ​​the battery cell 110 where the amount of heat generated is high.

[0059] As shown in FIG. 3, when the temperature of the battery cell 110 rises, heat H1 and H2 transferred from the cell cooling unit 120 are transferred to the hybrid PCM unit 140 along the heat transfer sheet 150 and the fin member 130, and then heat the battery cell 110 through the hybrid PCM unit 140.

[0060] At this time, the upper part of the battery cell 110 is heated very quickly through the composite phase change material 144 provided in the first division region A of the hybrid PCM unit 140, and the lower part of the battery cell 110 is heated relatively slowly through the reference phase change material 142 provided in the second division region B of the hybrid PCM unit 140. Therefore, since the amount of heat transfer H1 through the composite phase change material 144 is greater than the amount of heat transfer H2 through the reference phase change material 142, the heating effect on the upper part of the battery cell 110 far away from the cell cooling unit 120 can be further enhanced.

[0061] On the other hand, when the battery module is fast-charged at room temperature and the temperature reaches or exceeds the melting point of the hybrid PCM section 140, the high latent heat of the hybrid PCM section 140 can act as a thermal buffer that significantly reduces the maximum temperature and maximum temperature deviation of the battery cells 110.

[0062] In addition, when cooling or heating the battery module, heat can be rapidly transferred from the cooling plate 122 of the cell cooling unit 120 to the upper part of each battery cell 110 via the fin member 130 to which the heat transfer sheet 150 is attached. That is, when cooling or heating, heat is transferred from the cooling plate 122 to the fin member 130, and the heat is rapidly transferred toward the upper part of the battery cell 110 perpendicular to the cooling plate 122 via the heat transfer sheet 150 attached to the fin member 130 and having very high thermal conductivity.

[0063] At this time, heat is quickly transferred from the heat transfer sheet 150 to the upper part of the battery cell 110 through the composite phase change material 144 in the first divided region A located in the upper part of the hybrid PCM unit 140 far from the cooling plate 122. Meanwhile, due to the reference phase change material 142 in the second divided region B located in the lower part of the hybrid PCM unit 140 near the cooling plate 122, less heat is transferred between the heat transfer sheet 150 and the lower part of the battery cell 110 than the upper part.

[0064] As described above, the heat transfer to the upper and lower parts of the battery cell 110 is appropriately adjusted by the hybrid PCM unit 140, so that the upper and lower parts of the battery cell 110 can be uniformly and quickly cooled or heated.

[0065] For reference, when a heat transfer sheet 150 having high thermal conductivity between each battery cell 110 is attached to the fin member 130, heat transfer can occur quickly in a vertical direction from the cooling plate 122, thereby solving the temperature deviation between the upper and lower parts of the battery cell 110, which is a problem in the thermal management structure.

[0066] FIG. 6 is a graph showing the maximum temperature and maximum temperature deviation of the battery cell 110 shown in FIG. 1 during fast charging, and FIG. 7 is a graph showing the maximum temperature and minimum temperature of the battery cell 110 during heating of the battery cell 110 shown in FIG. 1.

[0067] That is, Figures 6 and 7 are comparative experimental graphs between a battery module to which the thermal management structure 100 of a battery cell according to this embodiment is applied (e.g., indicated as "Proposed Design") and an existing battery module to which the thermal management structure 100 of a battery cell according to this embodiment is not applied (indicated as "Baseline").

[0068] As shown in Figure 6, the maximum temperature (Tmax) and maximum temperature deviation (ΔTmax) during fast charging in the "proposed design" are generally smaller than those in the "baseline." In particular, the "proposed design" uses the latent heat of the phase change material, and therefore exhibits characteristics that are stably maintained at temperatures below the melting point, whereas the "baseline" exhibits temperature changes that rise above the melting point and then suddenly drop, which may result in a shortened product lifespan and safety issues.

[0069] As shown in Figure 7, when the temperature of the "proposed design" increases, the maximum temperature and the difference between the maximum temperatures are generally smaller than those of the "baseline." In particular, since the "proposed design" uses the latent heat of the phase change material, the temperature tends to remain stable within a certain range, whereas the "baseline" shows very rapid changes in temperature.

[0070] As described above, the embodiments of the present invention have been described with specific details such as specific components and limited embodiments and drawings, but these are merely provided to facilitate a more general understanding of the present invention, and the present invention is not limited to the above embodiments, and a person having ordinary knowledge in the field to which the present invention belongs can make various modifications and variations from such descriptions. Therefore, the idea of ​​the present invention should not be limited to the described embodiments, and it can be said that not only the scope of the claims described below, but also all things that are equivalent to the scope of the claims or have equivalent modifications fall within the scope of the idea of ​​the present invention.

Claims

1. A plurality of battery cells arranged in a repeated fashion; a cell cooling unit that is thermally connected to one side of the battery cell and cools or heats the battery cell when necessary; and A thermal management structure for a battery cell including: a hybrid PCM portion formed of different types of phase change materials (PCMs) that is disposed between each of the battery cells to absorb heat generated in the battery cells and that is disposed in a plurality of divided regions that are divided into shapes corresponding to a temperature gradient pattern of the battery cells.

2. The hybrid PCM unit is divided into a plurality of divided regions according to a temperature gradient pattern of the battery cell, The thermal management structure of a battery cell according to claim 1 , wherein the phase change materials disposed in the divided regions have different thermal conductivities.

3. Each of the divided regions includes: As the temperature of the battery cell corresponding to each of the divided regions increases, a phase change material having a relatively high thermal conductivity among the phase change materials is disposed, 3. The thermal management structure of claim 2, wherein as the temperature of the battery cell corresponding to each divided region decreases, a phase change material having a relatively low thermal conductivity among the phase change materials is disposed.

4. The hybrid PCM unit includes: A reference phase change material formed only of pure phase change material; and 4. The thermal management structure of claim 3, wherein the phase change material is a composite phase change material formed by combining a heat transfer material having a higher thermal conductivity than the reference phase change material with the reference phase change material.

5. The synthetic phase change material comprises: The thermal management structure of a battery cell according to claim 4 , wherein the thermal conductivity is changed by adjusting a content of the heat transfer material combined with the reference phase change material.

6. The heat transfer material is The thermal management structure of a battery cell according to claim 5 , comprising at least one of a metal foam, a carbon-based material, a metal fin, and a nano-material, the material having a higher thermal conductivity than the reference phase change material.

7. 2. The thermal management structure of claim 1, further comprising: a fin member made of a metal material that is in thermally conductive contact with one surface of the hybrid PCM portion, has one side connected to the cell cooling portion, and serves as a heat transfer path between the hybrid PCM portion and the cell cooling portion.

8. 8. The thermal management structure of a battery cell according to claim 7, further comprising: a heat transfer sheet attached to one surface of the fin member in contact with the hybrid PCM portion and made of a material having a higher thermal conductivity than the fin member to improve the heat transfer performance of the fin member.

9. The thermal management structure of a battery cell according to claim 8, wherein the heat transfer sheet is made of a graphite material.

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