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 positions on 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. Therefore, research and development of batteries has been intensified along with the trend of expansion of 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 due to various reasons, such as damage caused by impact, design errors, short circuits, and harsh usage environments, and it is still difficult to completely prevent them.

[0004] In recent years, the widespread use of electric vehicles has been rapidly increasing. Typical electric vehicles use high-capacity battery packs. While increasing the performance and capacity of such battery packs is important, preventing the risk of fire and explosion from causing damage to human life and property is also extremely important. Therefore, research and development efforts have been actively conducted in recent years to develop battery packs that combine 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 a battery pack under fast charging and harsh driving conditions of electric vehicles, and also to reduce the risk of fire and explosion in battery modules 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, a conventional 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 within the battery cell due to the temperature difference between the inlet and outlet of the coolant supplied to the cooling plate, and the cooling plate located at the bottom also causes a temperature difference between the top and bottom of the battery cell. Such a temperature gradient within the battery cell leads to different degrees of deterioration within the battery cell, and if the battery cell is continuously operated in a state where the temperature gradient within the battery cell is large, there is a high possibility that serious problems 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 Systems for Next-Generation High-Energy-Density Batteries Using Composite Phase-Change Heat Transfer Packages" (Project Number: 1711162708, Research Period: 2019.03.01~2023.02.28), funded by the Ministry of Science and ICT. 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 thermal management structure for a battery cell that can act as a heat buffer to absorb heat generated by the battery cell using the latent heat of the hybrid PCM during fast charging, minimize the temperature deviation of the battery cell during cooling or heating, and promote the improvement of the battery cell life and the maintenance of 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, including: a plurality of repeatedly arranged battery cells; a cell cooling unit connected to one side of the battery cell to be able to conduct heat and cooling the battery cell or heating it as needed; and a hybrid PCM unit formed 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.

[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 with 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 with a relatively low thermal conductivity among the phase change materials may be disposed in each divided region.

[0014] Preferably, the hybrid PCM portion may be provided with a reference phase change material formed only from a pure phase change material, or 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, thereby achieving 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 nanomaterials, which have 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 heat-transferably contact with one surface of the hybrid PCM unit, has one side connected to the cell cooling unit, and serves as a heat transfer path between the hybrid PCM unit and the cell cooling unit.

[0018] Preferably, the thermal management structure of a battery cell according to an embodiment of the present invention may further include a heat transfer sheet attached to one surface of the fin member that contacts 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.

[0019] The heat transfer sheet may be made of graphite. [Effects of the Invention]

[0020] The thermal management structure of a battery cell according to an embodiment of the present invention applies a hybrid PCM part formed of different types of phase change materials to the battery cell, thereby reducing temperature deviation due to the position of the battery cell, and as a result, 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 an 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. When the battery cell is cooled or heated, the hybrid PCM can minimize the temperature deviation depending on the 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 an 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 temperature of the battery cell rises, the heat transferred from the cell cooling section can be easily transferred to each battery cell.

[0023] In addition, the thermal management structure of a 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, 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, thereby improving the efficiency of heat transfer between the hybrid PCM section and the cell cooling section, and stably transferring heat to specific parts of the battery cell far away from the cell cooling section, thereby reducing the temperature deviation of the battery cell due to 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 section in a thin pouch shape and the heat transfer sheet in a thin film shape, so that even when the hybrid PCM section and the heat transfer sheet are disposed between each battery cell, the weight and size of the battery cell do not increase significantly, 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 preventing an abnormal increase in temperature of a specific part of the battery cell and effectively preventing fires and explosions of the battery cell due to an abnormal increase in temperature of the battery cell. [Brief explanation of the drawings]

[0027] [Figure 1] 1 is a diagram illustrating a schematic diagram of a thermal management structure of a battery cell according to an embodiment of the present invention. [Figure 2] 2 is an exploded perspective view of the main part of the heat management structure of the battery cell shown in FIG. 1. FIG. [Figure 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 heat management structure of the battery cell shown in FIG. 2. [Figure 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 the maximum temperature and maximum temperature deviation of the battery cell shown in FIG. 1 during rapid charging. [Figure 7] 2 is a diagram showing the maximum temperature and the minimum temperature of the battery cell shown in FIG. 1 when the temperature of the battery cell is rising. DETAILED DESCRIPTION OF THE INVENTION

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

[0029] FIG. 1 is a diagram illustrating a schematic view of a battery cell thermal management structure 100 according to one embodiment of the present invention, FIG. 2 is an exploded perspective view of the main parts of the battery cell thermal management structure 100 shown in FIG. 1, FIG. 3 is a diagram illustrating the heat transfer path due to cooling and heating of the battery cell 110 shown in FIG. 2, FIG. 4 is a diagram illustrating another example of the battery cell thermal management structure 100 shown in FIG. 2, and FIG. 5 is a diagram illustrating 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 one embodiment of the present invention may include a battery cell 110, a cell cooling unit 120, a fin member 130, a hybrid PCM unit 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 having a rectangular thin plate structure, but is not limited thereto and may have a structure of other shapes. In particular, for the convenience of describing the thermal management structure 100 for a battery cell according to the present embodiment, the battery cell 110 is described with a front-rear direction, a top-bottom direction, and a left-right direction set in advance.

[0032] For example, the battery cells 110 may be arranged in an upright structure above the cell cooling unit 120, and a plurality of the battery cells 110 may be arranged alternately in the front-to-rear direction. The cell cooling unit 120 may be connected to the lower part of the battery cell 110, and the cell tab 112 of the battery cell 110 may be arranged on the upper part 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 charge and discharge electricity and may be housed inside a battery module housing (not shown). Typically, the battery cells 110 may generate heat during the charging and discharging process, causing the temperature to rise.

[0034] Here, the battery cells 110 may be arranged such that a plurality of them are repeatedly and closely contacted along the front-rear direction. A cell tab 112 may extend upward from the upper portion of the battery cell 110. For reference, a lower portion of the battery cell 110 may be connected to the upper surface of the cell cooling unit 120 to enable heat transfer.

[0035] 1, the cell cooling unit 120 of this embodiment may be heat-conductively connected to the lower part of the battery cell 110 to cool or, when necessary, heat the battery cell 110. That is, the cell cooling unit 120 may cool the battery cell 110 during use of the battery module to prevent overheating of the battery cell 110 and a resulting decrease in efficiency, or may preheat the battery cell 110 in an extremely cold environment or by heating the battery cell 110 before actual use.

[0036] For example, the cell cooling section 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 may be formed of a metal material with high thermal conductivity. For reference, a gap filler with excellent thermal conductivity may 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 able to transfer heat.

[0039] For example, the heat sink 124 may use cooling water W flowing in from the outside to cool or heat the cooling plate 122. 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 with 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 to allow heat transfer. The lower portion of the fin member 130 may be placed on the cooling plate 122 of the cell cooling unit 120 to allow heat transfer.

[0041] For example, the fin member 130 may include a fin panel 132 that contacts one side of the hybrid PCM unit 140, and a fin mount 134 that is flange-shaped at the lower end of the fin panel 132 and is mounted on the cooling plate 122. In this case, the contact surface of the fin panel 132 may be shaped to correspond to one side of the hybrid PCM unit 140, and the fin mount 134 may be connected to the cooling plate 122 so as to be capable of transmitting heat.

[0042] 1 to 3, the hybrid PCM unit 140 of this 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 have a thin pouch structure that accommodates 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 can 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 the temperature gradient pattern of the battery cell 110. In this case, the phase change materials 142 and 144 arranged in the divided regions A and B may have different thermal conductivities according to the temperature gradient of the battery cell 110.

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

[0046] Therefore, a high-temperature region of the battery cell 110 may be cooled or heated more quickly 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 part 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 from a pure phase change material, and a composite phase change material 144 formed 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 can be made of only a paraffin-based material having low thermal conductivity.

[0049] The thermal conductivity of the composite phase change material 144 can be changed by adjusting the content of the heat transfer material synthesized with 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 manufactured with various compositions depending on the design conditions and circumstances for the battery cell thermal management structure 100.

[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 that has higher thermal conductivity than the fin member 130 to further improve 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 shows 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 shown in FIG. 4, the hybrid PCM section 140 may be divided into three divided regions A, B, and C. As a result, the hybrid PCM section 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 for a battery cell shown in FIG. 4 may perform more precise thermal management of the battery cell 110 than that shown in FIG. 2.

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

[0055] However, the present invention is not limited thereto, and as described above, the divided regions A, B, and C of the hybrid PCM unit 140 of this 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 standard 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 standard phase change material 142, a greater cooling effect can be obtained in areas of the battery cell 110 where heat generation 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 is transferred to the hybrid PCM unit 140 along the heat transfer sheet 150 and the fin member 130, and then heats the battery cell 110 through the hybrid PCM unit 140.

[0060] At this time, the upper portion 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 portion 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 portion of the battery cell 110, which is far from the cell cooling unit 120, can be further enhanced.

[0061] On the other hand, if the battery module is fast charged at room temperature and the temperature reaches a temperature above the melting point of the hybrid PCM unit 140, the high latent heat of the hybrid PCM unit 140 can have the effect of acting as a thermal buffer, significantly reducing the maximum temperature and maximum temperature deviation of the battery cell 110.

[0062] Furthermore, 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 top 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 top of the battery cell 110 perpendicular to the cooling plate 122 via the heat transfer sheet 150, which has very high thermal conductivity and is attached to the fin member 130.

[0063] At this time, heat is quickly transferred from the heat transfer sheet 150 to the upper part of the battery cell 110 via the composite phase change material 144 in the first divided region A located at the upper part of the hybrid PCM unit 140, which is far from the cooling plate 122. On the other hand, due to the base phase change material 142 in the second divided region B located at 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, if a heat transfer sheet 150 with high thermal conductivity is attached to the fin member 130 between each battery cell 110, heat can be transferred quickly in the vertical direction from the cooling plate 122, thereby solving the temperature difference 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 temperature rise 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 the 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 the 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 for the "proposed design" are generally smaller than those for the "baseline." In particular, the "proposed design" exhibits the characteristic of being stably maintained at temperatures below the melting point because it uses the latent heat of the phase change material, 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 rises in the "proposed design," the maximum temperature and the difference between the maximum temperatures are generally smaller than in the "baseline." In particular, the "proposed design" tends to maintain a constant temperature within a certain range because it uses the latent heat of the phase change material, while the "baseline" shows very rapid temperature changes.

[0070] As described above, the embodiments of the present invention have been described using specific details such as specific components and limited examples and drawings, but these are provided merely to facilitate a more comprehensive understanding of the present invention, and the present invention is not limited to the above embodiments, and those skilled in the art will appreciate that various modifications and variations can be made from such descriptions. Therefore, the spirit 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 below, but also all that are equivalent to or have equivalent modifications within the scope of the claims fall within the scope of the spirit of the present invention.

Claims

1. A plurality of battery cells arranged repeatedly; a cell cooling unit that is heat-transferably connected to one side of the battery cell and that cools or heats the battery cell when necessary; and A thermal management structure for a battery cell, comprising: a hybrid PCM portion formed of different types of phase change materials (PCMs) disposed between the battery cells to absorb heat generated in the battery cells, the hybrid PCM portion being disposed in a plurality of divided regions 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 has: 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 is disposed, 3. The thermal management structure of claim 2, wherein a phase change material having a relatively low thermal conductivity is disposed among the phase change materials as the temperature of the battery cell corresponding to each divided region decreases.

4. The hybrid PCM unit a reference phase change material formed solely 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, the composite phase change material having a higher thermal conductivity than the reference phase change material.

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

6. The heat transfer material is The thermal management structure of claim 5 , comprising at least one of a metal foam, a carbon-based material, a metal fin, and a nanomaterial, each of which has a thermal conductivity higher than that of 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 heat-transferable 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 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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