Battery pack structure

Abstract

The utility model discloses a kind of battery pack structures, its subject is to provide a kind of battery pack structure which can inhibit cost, the reduction of electric power efficiency and large-scale, while realizing the temperature equalization of battery unit. Battery pack structure is the structure of the battery pack that multiple battery units are arranged and contained in battery housing, it has: cooling component, it is set in battery housing;And heat transfer component, it is between the cooling surface of cooling component and battery unit, according to the heat transfer coefficient of cooling surface and the thickness of heat transfer component, the distribution of the heat transfer area of battery unit and cooling component is adjusted, regarding heat transfer area, it is set as two ends relative to the central of battery unit larger and / or the end portion side of the arrangement of battery unit is less than the central of the arrangement of battery unit.

Description

Technical Field

[0001] This utility model relates to a battery pack structure. Background Technology

[0002] Patent Document 1 discloses a battery pack comprising: a plurality of Peltier elements; a plurality of control circuits, each controlling one of the plurality of Peltier elements; a plurality of battery cells, each connected to at least one end of one of the plurality of Peltier elements; and a heat transfer component connected to the other end of the plurality of Peltier elements. In this battery pack, the plurality of control circuits are individually driven to control the heat transfer direction of the plurality of Peltier elements, and the heat transfer component facilitates thermal movement between the battery cells connected to the Peltier elements, thereby equalizing the temperature of the plurality of battery cells.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2023-23527 Utility Model Content However, in the aforementioned battery packs, each cell requires a Peltier element and control circuitry, as well as a heat exchange mechanism on the heat dissipation side of the Peltier element, leading to increased cost and size. Furthermore, the required power to drive the Peltier element results in higher electricity costs. Therefore, in the aforementioned battery packs, constructing a heat exchanger based on a Peltier element for each cell results in disadvantages in terms of cost, power efficiency, and size.

[0004] This invention was made in view of the above circumstances, and its purpose is to provide a battery pack structure that can suppress the reduction of cost and power efficiency and increase the size, and achieve temperature uniformity of battery cells.

[0005] To achieve the above objectives, the present invention provides a battery pack structure. A battery pack structure for arranging and housing multiple battery cells within a battery casing, the battery pack structure comprises: Cooling components are disposed in the battery casing; and A heat transfer component, which is located between the cooling surface of the cooling component and the battery cell. Based on the heat transfer coefficient of the cooling surface and the thickness of the heat transfer component, the distribution of the heat transfer area between the battery cell and the cooling component is adjusted. Regarding the heat transfer area, it is set such that both ends are larger than the center of the battery cell and / or the end sides of the arrangement of the battery cells are smaller than the center of the arrangement of the battery cells.

[0006] According to the battery pack structure of this design, the heat transfer area of ​​the battery cells and cooling components is larger relative to the central ends of the battery cells, and / or the end sides of the battery cell arrangement are smaller than the central side of the battery cell arrangement. This allows for the suppression of cost reduction, power efficiency degradation, and large-scale production, and also enables the suppression and equalization of temperature variations between individual battery cells and / or arranged battery cells housed in the battery casing.

[0007] Utility Model Effect According to this utility model, a battery pack structure can be provided that can suppress the reduction of cost and power efficiency and the increase in size, and achieve the uniformity of temperature of battery cells. Attached Figure Description

[0008] Figure 1 This is a partial perspective view illustrating the battery pack structure involved in this embodiment.

[0009] Figure 2 This is a schematic diagram illustrating the temperature distribution of the cooling components in the battery mounting section of the battery casing.

[0010] Figure 3 This is a schematic diagram illustrating the temperature distribution of the battery cells in the battery mounting section placed in the battery casing.

[0011] Figure 4 It is a diagram showing the distribution of heat transfer area between battery cells and cooling components.

[0012] Figure 5 It is a graph showing the relationship between the heat transfer area, heat transfer coefficient and temperature in a single battery cell.

[0013] Figure 6 It is a graph showing the relationship between the heat transfer area, heat transfer coefficient and temperature in the arranged battery cells.

[0014] Figure 7 It is a chart showing the results of temperature evaluation in a battery pack with multiple battery cells. Detailed Implementation

[0015] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0016] Figure 1 This is a partial perspective view of the battery pack 11 illustrating the battery pack structure involved in this embodiment. Figure 2 This is a schematic diagram illustrating the temperature distribution of the cooling component 22 in the battery mounting section 21 of the battery casing 20. Figure 3 This is a schematic diagram illustrating the temperature distribution of the battery cell 10 placed in the battery mounting section 21 of the battery casing 20. Additionally, in Figure 2 and Figure 3In this system, the shades of color represent temperature distribution, with darker colors indicating lower temperatures.

[0017] like Figure 1 As shown, the battery pack structure involved in this embodiment is a battery pack 11 having multiple battery cells 10. The battery cells 10 are housed in a state where they are arranged in the battery casing 20.

[0018] The battery cell 10 is formed in a cuboid shape and is aligned in the same direction in the width direction. Figure 1 In the state of (X direction), along one direction ( Figure 1 Arranged in the Y direction.

[0019] The battery housing 20 has multiple rows of battery mounting sections 21, on the upper part of which multiple battery cells 10 are arranged.

[0020] The battery casing 20 includes a cooling component 22. The cooling component 22 is disposed in each battery mounting portion 21, and its upper surface is provided as a cooling surface 23. The battery cell 10 is placed on the cooling surface 23 of the cooling component 22 via a heat transfer component 24.

[0021] The cooling component 22 has a flow path (not shown) inside, through which a cooling medium such as coolant flows. For example, the flow path is located at the center in the width direction of each battery mounting portion 21 in the cooling component 22. Furthermore, as the cooling medium flows through this flow path, the heat of the battery cell 10 is transferred to the cooling component 22 via the heat transfer component 24, and the battery cell 10 is cooled.

[0022] In the battery pack 11 equipped with cooling component 22, the temperature of the battery cell 10 is directly related to the power efficiency. Therefore, it is desirable to reduce the temperature deviation in the individual battery cell 10 and the temperature deviation between the arranged battery cells 10.

[0023] However, as Figure 2 As shown, in the battery mounting section 21 of the cooling component 22, the central side of the width direction X is cooled more than the two ends of the width direction X by the cooling medium flowing in the central flow path of the cooling medium, thus generating a temperature deviation in the individual battery cell 10. Furthermore, as... Figure 3 As shown, the battery cells 10 arranged in the battery mounting section 21 have a high temperature at the center side in the arrangement direction Y and a lower temperature towards both ends, thus causing a temperature difference between the battery cells 10.

[0024] Therefore, in this embodiment, based on the heat transfer coefficient of the cooling surface 23 of the cooling component 22 and the thickness of the heat transfer component 24 between the cooling surface 23 and the battery cell 10, the distribution of the heat transfer area between the battery cell 10 and the cooling component 22 is adjusted to suppress the temperature deviation in the individual battery cell 10 and the temperature deviation between the arranged battery cells 10, so as to achieve equalization.

[0025] Specifically, according to the following formula (1), the distribution of the heat transfer area A is adjusted so that the product of the heat transfer coefficient λ and the heat transfer area A becomes constant.

[0026]

[0027] but, Q: Heat flow [W] A: Heat transfer area [m²] 2 ] λ: Heat transfer coefficient [W / mK] ΔT: Temperature difference [K] L: Thickness of the heat transfer component [m] In addition, if there is a deviation in the thickness of the heat transfer component 24 between the battery cell 10 and the cooling component 22 during the assembly process, the distribution of the heat transfer area A between the battery cell 10 and the cooling component 22 is adjusted based on the prior knowledge of the deviation in the thickness of the heat transfer component 24.

[0028] Hereinafter, a specific example of temperature equalization of the battery cell 10 in this embodiment will be described.

[0029] Figure 4 This is a diagram showing the distribution of the heat transfer area A of the battery cell 10 and the cooling component 22. Figure 5 It is a graph showing the relationship between the heat transfer area A, heat transfer coefficient λ and temperature T in a single battery cell 10. Figure 6 This is a graph showing the relationship between the heat transfer area A, heat transfer coefficient λ, and temperature T in the arranged battery cells 10. Additionally, in Figure 4 In the diagram, the heat transfer area A is represented by a wavy line. The larger the period of the wavy line, the larger the heat transfer area A is.

[0030] (Temperature equalization within individual battery cells) like Figure 4 As shown, in the battery pack structure according to this embodiment, the battery cell 10 ( ) is arranged in the center of the arrangement. Figure 4 In the battery cell 10C on the left side of the array, the heat transfer area A is larger at both ends PE relative to the central PC in the width direction. Similarly, the battery cells 10C arranged at the ends of the array... Figure 4In the battery cell 10E on the right side, the heat transfer area A is larger at both ends PE than the central PC in the width direction.

[0031] That is, such as Figure 5 As shown, in the width direction X of the battery cell 10, the heat transfer coefficient λ of the cooling component 22 decreases relative to the central PC and becomes smaller at both ends PE, making it difficult to cool. Therefore, in this embodiment, by increasing the heat transfer area A of the cooling component 22 relative to the central PC at the two ends PE, which are difficult to cool, the temperature T deviation of each battery cell 10 is suppressed and made equal.

[0032] (Temperature equalization among battery cells) like Figure 4 As shown, in the battery pack structure according to this embodiment, the battery cells 10 arranged at the ends of the arrangement ( Figure 4 The heat transfer area A of the battery cell 10E on the right side of the array is greater than that of the battery cell 10 (located in the center of the array). Figure 4 The heat transfer area A of the battery cell 10C on the left side of the image is small.

[0033] That is, such as Figure 6 As shown, in the arrangement direction Y of the arranged battery cells 10, the heat transfer coefficient λ of the cooling component 22 becomes smaller in the center compared to the two ends of the arrangement, making it difficult to cool. Therefore, in this embodiment, by increasing the heat transfer area A of the cooling component 22 in the center of the difficult-to-cool arrangement compared to the two ends of the arrangement, the temperature deviation of the arranged battery cells 10 is suppressed and made uniform.

[0034] Thus, according to the battery pack structure of this embodiment, the heat transfer area A of the battery cell 10 and the cooling member 22 increases at both ends relative to the center of the battery cell 10, and the end sides of the arrangement of battery cells 10 decrease in size compared to the center of the arrangement of battery cells 10. This suppresses the reduction in cost and power efficiency, as well as the need for larger sizes, and also suppresses and equalizes the temperature deviation between the individual battery cells 10 housed in the battery casing 20 and the arranged battery cells 10.

[0035] In addition, in the above embodiment, the heat transfer area A of the battery cell 10 and the cooling component 22 is made larger at both ends relative to the center of the battery cell 10, and the end side of the arrangement of battery cells 10 is made smaller than the center of the arrangement of battery cells 10. However, the heat transfer area A of the battery cell 10 and the cooling component 22 may only be made larger at both ends relative to the center of the battery cell 10, or the end side of the arrangement of battery cells 10 may only be made smaller than the center of the arrangement of battery cells 10.

[0036] (Example) Heaters H1 to H24, simulating 24 battery cells 10, are arranged on the cooling component 22 to form a battery pack. The temperature T in battery cell 10 was evaluated.

[0037] (1) Evaluation object An embodiment in which the distribution of the heat transfer area A between the heaters H1 to H24 and the cooling component 22 was adjusted, and a comparative example in which the distribution of the heat transfer area A between the heaters H1 to H24 and the cooling component 22 was kept constant, were evaluated. In the embodiment, the heat transfer area A of the heaters H1 to H24 at the ends of the arrangement was smaller than that of the heaters H1 to H24 in the center of the arrangement.

[0038] (2) Evaluation results Figure 7 This is a graph representing the evaluation results, showing the extracted temperatures of heaters H1, H3, H10, H16, H18, H22, and H24 out of heaters H1 to H24. In the example, it was confirmed that the maximum temperature difference relative to the average temperature among the 24 heaters H1 to H24 was 4.2°C, indicating a smaller temperature deviation. In the comparative example, the maximum temperature difference relative to the average temperature among the 24 heaters H1 to H24 was 10.3°C.

[0039] Therefore, in a comparative example where the distribution of the heat transfer area A between the battery cell 10 and the cooling component 22 was kept constant, it was confirmed that the temperature of the heater at the end decreased, and the temperature difference between the center and the end of the arrangement increased. In contrast, it was found that in the embodiment, by adjusting the distribution of the heat transfer area A between the heater and the cooling component 22, the temperature deviation of the heater simulating the battery cell 10 could be made more uniform.

[0040] Symbol Explanation 10-Battery cell, 11-Battery pack, 20-Battery casing, 22-Cooling component, 23-Cooling surface, 24-Heat transfer component, A-Heat transfer area, λ-Heat transfer coefficient.

Claims

1. A battery pack structure comprising a plurality of battery cells arranged and housed in a battery casing, the battery pack structure being characterized by having: Cooling components are disposed in the battery casing; and A heat transfer component, which is located between the cooling surface of the cooling component and the battery cell. Based on the heat transfer coefficient of the cooling surface and the thickness of the heat transfer component, the distribution of the heat transfer area between the battery cell and the cooling component is adjusted. Regarding the heat transfer area, it is set such that both ends are larger than the center of the battery cell and / or the end sides of the arrangement of the battery cells are smaller than the center of the arrangement of the battery cells.

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