Battery pack

Abstract

The utility model relates to the technical field of batteries, and provides a battery pack, which comprises a plurality of battery cell groups, the battery cell groups are arranged side by side along the length direction of the battery pack, and each battery cell group comprises a plurality of battery cells which are sequentially arranged along the width direction of the battery pack; the side cold plates are arranged among the battery cell groups, and the two sides of each side cold plate are respectively bonded with the adjacent battery cells; wherein the side cold plate comprises a first plate body, a second plate body and connecting pieces, a liquid cooling runner is arranged in the first plate body, the first plate body is attached to the side wall of each battery cell, the second plate body is arranged at the upper end part of the first plate body, the two ends of the second plate body are respectively lapped at the end parts of two adjacent battery cells, and the connecting pieces are arranged at the two ends of the first plate body in the length direction. The battery pack provided by the utility model aims to solve the problems of poor thermal management performance and structural strength of the battery pack in the prior art.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to a battery pack. Background Technology

[0002] With the rise of new energy vehicles, the thermal management design of battery packs is directly related to the safety and service life of battery packs. How to design liquid cooling plates with better thermal management performance to improve the thermal management performance and structural strength of battery packs has become a hot research topic.

[0003] Existing CTP battery packs mostly use liquid cooling plates integrated with the lower housing. Due to their large size, the flatness of the product is affected, the flow distribution is unbalanced, and the thickness of the fluid boundary layer in the large flow channel increases. At the same time, the cold plate adopts stamping technology, and the uneven wall thickness leads to insufficient heat dissipation capacity. The flow channel size design of the cold plate affects the cooling, heat dissipation, and heating performance of the battery pack. In addition, the cold plate is a key component of the battery pack, and its structural design will also affect the rigidity of the battery pack. Utility Model Content

[0004] This invention provides a battery pack that aims to solve the problems of poor thermal management performance and structural strength in traditional battery packs.

[0005] To address the problems existing in the prior art, this utility model provides a battery pack, comprising:

[0006] A plurality of cell groups, each cell group being arranged side-by-side along the length of the battery pack, each cell group comprising a plurality of cells arranged sequentially along the width of the battery pack; and,

[0007] A side cooling plate is disposed between each of the battery cell groups, and the two sides of the side cooling plate are respectively bonded to the adjacent battery cells;

[0008] The side cooling plate includes a first plate, a second plate, and a connector. The first plate has a liquid cooling channel and is fitted to the side wall of each of the battery cells. The second plate is located at the upper end of the first plate and its two ends overlap the ends of two adjacent battery cells. The connector is located at both ends of the first plate in the length direction.

[0009] According to the present invention, a battery pack has a plurality of liquid cooling channels in the first plate body, each of which extends along the length direction of the first plate body and is arranged at intervals along the height direction of the first plate body.

[0010] According to the battery pack provided by this utility model, the first plate has n liquid cooling channels, the distance from the end of the first plate to the adjacent liquid cooling channel is L1, the height of the liquid cooling channel is L2, the distance between two adjacent liquid cooling channels is L3, the distance from the second plate to the adjacent liquid cooling channel is L4, and the height of the second plate is L5. The above parameters satisfy the following relationship:

[0011] 1.5(L1+L4+L5)≤(4L2+2L3)≤2(L1+L4+L5).

[0012] According to the battery pack provided by this utility model, the first plate is connected to the middle position of the second plate, the straight-line distance from the end of the second plate to the edge of the first plate is H1, the distance from the edge of the first plate to the edge of the liquid cooling channel is H2, and the width of the liquid cooling channel is H3. The above parameters satisfy the following relationship:

[0013] 2H1≤H3+H2≤4H1.

[0014] According to the battery pack provided by this utility model, the height L2 of the liquid cooling channel and the width H3 of the liquid cooling channel satisfy the following relationship: 2≤L2 / H3≤3.5;

[0015] The distance L3 between two adjacent liquid cooling channels and the distance H2 from the edge of the first plate to the edge of the liquid cooling channel satisfy the following relationship: 0.8 < H2 / L3 < 1.2.

[0016] According to the present invention, the length of each of the battery cells is 130-300mm, the width is 30-60mm, and the height is 105-140mm.

[0017] According to the present invention, the battery pack L1-L4 and H1-H3 satisfy the following relationships: 20mm≤L1≤25mm, 13mm≤L2≤16mm, 1.8mm≤L3≤3mm, 8mm≤L4≤12mm, 2mm≤L5≤5mm, 10mm≤H1≤15mm, 1.8mm≤H2≤3mm, and 4mm≤H3≤8mm.

[0018] According to the present invention, the total height of the side cooling plate L = L1 + nL2 + (n-1)L3 + L4 + L5, 95mm ≤ L ≤ 120mm; the total width of the side cooling plate H = 2H1 + 2H2 + H3, 20mm ≤ H ≤ 30mm.

[0019] According to the present invention, each of the battery cells is wrapped with a blue film around its periphery, and a first window is provided on both sides of the blue film of each battery cell. The first window is coated with thermally conductive adhesive, which is used to bond with the side cold plate. The sum of the adhesive coating areas on both sides of the battery cell is less than the side surface area of ​​the battery cell.

[0020] According to the present invention, a battery pack is provided in which each of the battery cells is wrapped with a blue film around its periphery, and a second window is opened at the end of the blue film of each battery cell. The second window is coated with thermally conductive adhesive, which is used to bond to the upper shell of the battery pack. The area of ​​the adhesive coating at the end of the battery cell is smaller than the end face area of ​​the battery cell.

[0021] The battery pack provided by this utility model has a cell side contacting a side cooling plate. The side cooling plate adopts a modular combination design, which improves the high-temperature cooling and low-temperature heating performance and the rigidity of the battery pack. In addition, the side cooling plate is provided with a connector, which replaces the longitudinal beam structure of the battery pack in the traditional technology, and can further improve the rigidity of the battery pack. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the battery pack provided by this utility model;

[0024] Figure 2 yes Figure 1 A sectional view of the structure;

[0025] Figure 3 yes Figure 1 Schematic diagram of the middle side cold plate;

[0026] Figure 4 yes Figure 1 A cross-sectional view of the middle side cold plate.

[0027] Reference numerals: 1. Battery cell; 2. Side cooling plate; 21. First plate; 22. Second plate; 23. Connector; 24. Liquid cooling channel. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0029] In the description of the embodiments of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this utility model based on the specific circumstances.

[0030] In the description of the embodiments of this utility model, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this utility model.

[0031] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0032] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0033] The following disclosure provides numerous different embodiments or examples for implementing various structures of the present invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of the invention. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this invention; however, those skilled in the art will recognize the applicability of other processes and / or the use of other materials.

[0034] The following is combined with Figures 1-4 This invention describes the battery pack provided by this utility model.

[0035] With the rise of new energy vehicles, the thermal management design of battery packs directly affects their safety and lifespan. Designing liquid cooling plates with better thermal management performance to improve the thermal management performance and structural strength of battery packs has become a current research hotspot. Given the problems of poor thermal management performance and structural strength in traditional battery pack technologies, this utility model provides a battery pack comprising several cell groups 1 and a side cooling plate 2.

[0036] Please see Figure 1 The battery comprises multiple cell groups arranged side-by-side along the length of the battery pack. Each cell group includes multiple cells 1 arranged sequentially along the width of the battery pack. Side cooling plates 2 are located between the cell groups, and both sides of the side cooling plates 2 are bonded to adjacent cells 1. For details, please refer to [link to relevant documentation]. Figures 2-3 The side cooling plate 2 includes a first plate 21, a second plate 22, and a connector 23. The first plate 21 has a liquid cooling channel 24 inside and is fitted to the side wall of each battery cell 1. The liquid cooling channel 24 is in close contact with the heat-generating area of ​​the battery cell 1, allowing the coolant to quickly dissipate heat. The second plate 22 is located at the upper end of the first plate 21, with its two ends overlapping the ends of two adjacent battery cells 1. This overlap ensures the stability of the connection between the side cooling plate 2 and the battery cells 1, making the installation of the side cooling plate 2 more stable.

[0037] Furthermore, connectors 23 are located at both ends of the first plate 21 along its length. (See also...) Figure 3The connector 23 can be connected to the first plate 21 by welding. The connector 23 blocks the liquid cooling channel 24. A metal insert with a screw hole is provided on the connector 23, which can be connected to other battery structures by bolts and screw holes. By setting the connector 23 on the side cold plate 2, the connector 23 can act as a crossbeam of the battery pack, eliminating the need for an additional beam and improving the strength of the battery pack.

[0038] The battery pack provided by this utility model has a cell 1 in contact with a side cooling plate 2. The side cooling plate 2 adopts a modular combination design, which improves the high-temperature cooling and low-temperature heating performance and the rigidity of the battery pack. In addition, the side cooling plate 2 is provided with a connector 23, which replaces the longitudinal beam structure of the battery pack in the traditional technology, and can further improve the rigidity of the battery pack.

[0039] To improve heat dissipation, the first plate 21 has multiple liquid cooling channels 24, each extending along the length of the first plate 21 and spaced apart along its height. The length of each liquid cooling channel 24 is aligned with the arrangement direction of the battery cells 1, ensuring that the coolant flows evenly through the heat dissipation area of ​​each battery cell 1. The specific number of liquid cooling channels 24 can be configured according to the heat generation of the battery cell 1. In areas with high heat load, the channel density can be increased to improve cooling efficiency; this invention does not limit this. In an optional embodiment, the first plate 21 is provided with four liquid cooling channels 24, which are evenly arranged. It should be noted that the first plate 21 adopts a multi-cavity extrusion structure, and the hollow structure provides the design for the liquid cooling channels 24. The combination of the hollow structure and the solid structure can improve the rigidity of the battery pack.

[0040] Specifically, please refer to Figure 4 The first plate 21 has n liquid cooling channels 24. The distance from the end of the first plate 21 to the adjacent liquid cooling channel 24 is L1, the height of the liquid cooling channel 24 is L2, the distance between two adjacent liquid cooling channels 24 is L3, the distance from the second plate 22 to the adjacent liquid cooling channel 24 is L4, and the height of the second plate 22 is L5. Further, the first plate 21 is connected to the middle of the second plate 22. The straight-line distance from the end of the second plate 22 to the edge of the first plate 21 is H1, the distance from the edge of the first plate 21 to the edge of the liquid cooling channel 24 is H2, and the width of the liquid cooling channel 24 is H3.

[0041] In the technical solution provided by this utility model, to avoid resonance between the battery pack and the vehicle, and considering the requirements for lightweighting and weight reduction, the stiffness of the battery pack is characterized by modal analysis, and the modal analysis needs to meet the requirements of 35Hz-50Hz. Furthermore, while ensuring the stiffness of the battery pack, the thermal management performance of the battery pack still needs to be considered. In a specific implementation, the high-temperature cooling performance of the battery pack needs to meet the following requirements: when the ambient temperature is 40℃, the coolant temperature is 20-30℃, the initial battery temperature is 35℃-45℃, and the maximum battery temperature is not allowed to exceed 47℃, the battery temperature difference needs to be ≤5℃. Furthermore, the low-temperature heating performance of the battery pack needs to meet the following requirements: when the ambient temperature is -(30-40)℃, the temperature difference when the power battery assembly is heated from -(20-30)℃ to the lowest temperature T(20-25)℃ needs to be ≤10℃.

[0042] To meet the rigidity and thermal management performance requirements of the battery pack, this invention has conducted multiple experimental designs for various parameters of the battery pack, especially the parameters of the side cooling plate 2, L1-L5 and H1-H3, resulting in the following embodiments:

[0043]

[0044] This invention, through multiple parameter designs and experiments (including not only the 10 embodiments mentioned above), and through calculation and simulation, shows that for the battery pack to meet the stiffness requirements, the following parameters must satisfy the following relationships: distance L1 from the end of the first plate 21 to the adjacent liquid cooling channel 24; height L2 of the liquid cooling channel 24; distance L3 between two adjacent liquid cooling channels 24; distance L4 from the second plate 22 to the adjacent liquid cooling channel 24; and height L5 of the second plate 22: 1.5(L1+L4+L5)≤(4L2+2L3)≤2(L1+L4+L5). Furthermore, the following parameters must satisfy the following relationships: straight-line distance H1 from the end of the second plate 22 to the edge of the first plate 21; distance H2 from the edge of the first plate 21 to the edge of the liquid cooling channel 24; and width H3 of the liquid cooling channel 24: 2H1≤H3+H2≤4H1. It should be noted that the stiffness of the battery pack is generally characterized by modal analysis. By designing the parameters mentioned above, the battery pack's modes meet the 35-50Hz requirement, which can effectively avoid the problem of vehicle resonance.

[0045] Furthermore, the thermal management performance of the battery pack is related to the parameter design of the liquid cooling channel 24. To meet the requirements for thermal management performance, the height L2 and width H3 of the liquid cooling channel 24 need to satisfy the following relationship: 4 < L2 / H3 < 5; the distance L3 between two adjacent liquid cooling channels 24 and the distance H2 from the edge of the first plate 21 to the edge of the liquid cooling channel 24 need to satisfy the following relationship: 0.8 < H2 / L3 < 1.2.

[0046] In an optional embodiment, each battery cell 1 has a length of 130-300mm, a width of 30-60mm, and a height of 105-140mm. L1-L4 and H1-H3 satisfy the following relationships: 20mm≤L1≤25mm, 13mm≤L2≤16mm, 1.8mm≤L3≤3mm, 8mm≤L4≤12mm, 2mm≤L5≤5mm, 10mm≤H1≤15mm, 1.8mm≤H2≤3mm, 4mm≤H3≤8mm. Correspondingly, the total height L of the side cold plate 2 is L=L1+nL2+(n-1)L3+L4+L5, 95mm≤L≤120mm; the total width H of the side cold plate 2 is H=2H1+2H2+H3, 20mm≤H≤30mm.

[0047] As mentioned earlier, the side cooling plate 2 is bonded to the side wall of the battery cell 1. Specifically, each battery cell 1 is wrapped with a blue film around its periphery, and each side of the blue film of each battery cell 1 has a first window. Thermally conductive adhesive is applied to each of the first windows for bonding with the side cooling plate 2. It should be noted that the sum of the adhesive areas on both sides of the battery cell 1 is less than the side surface area of ​​the battery cell 1. Further, the height of the side window opening of the battery cell 1 is 60-90mm, and the width is 15-30mm. The ratio of the area of ​​the first window to the total side surface area of ​​the battery cell 1 is less than or equal to 2 / 3. In an optional embodiment, the length of the battery cell 1 is 148mm, the width is 55mm, the height is 108mm, the side window area is 65mm*35mm, and the adhesive coating dimensions are 65-80mm long and 35-40mm wide.

[0048] Furthermore, a second window is provided on the blue film at the end of each cell 1, and thermally conductive adhesive is applied to the second window. The thermally conductive adhesive is used to bond to the upper shell of the battery pack. The adhesive application area at the end of cell 1 is smaller than the end face area of ​​cell 1. In an optional embodiment, the top window area is 85mm*30mm, and the adhesive application dimensions are 85-100mm in length and 30-45mm in width.

[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A battery pack, characterized in that, include: A plurality of cell groups, each cell group being arranged side-by-side along the length of the battery pack, each cell group comprising a plurality of cells arranged sequentially along the width of the battery pack; and, A side cooling plate is disposed between each of the battery cell groups, and the two sides of the side cooling plate are respectively bonded to the adjacent battery cells; The side cooling plate includes a first plate, a second plate, and a connector. The first plate has a liquid cooling channel and is fitted to the side wall of each of the battery cells. The second plate is located at the upper end of the first plate and its two ends overlap the ends of two adjacent battery cells. The connector is located at both ends of the first plate in the length direction.

2. The battery pack according to claim 1, characterized in that, The first plate has multiple liquid cooling channels, each of which extends along the length of the first plate and is spaced apart along the height of the first plate.

3. The battery pack according to claim 2, characterized in that, The first plate has n liquid cooling channels. The distance from the end of the first plate to the adjacent liquid cooling channel is L1, the height of the liquid cooling channel is L2, the distance between two adjacent liquid cooling channels is L3, the distance from the second plate to the adjacent liquid cooling channel is L4, and the height of the second plate is L5. The above parameters satisfy the following relationship: 1.5(L1+L4+L5)≤(4L2+2L3)≤2(L1+L4+L5).

4. The battery pack according to claim 3, characterized in that, The first plate is connected to the middle of the second plate. The straight-line distance from the end of the second plate to the edge of the first plate is H1. The distance from the edge of the first plate to the edge of the liquid cooling channel is H2. The width of the liquid cooling channel is H3. The above parameters satisfy the following relationship: 2H1≤H3+H2≤4H1.

5. The battery pack according to claim 4, characterized in that, The height L2 of the liquid cooling channel and the width H3 of the liquid cooling channel satisfy the following relationship: 2≤L2 / H3≤3.5; The distance L3 between two adjacent liquid cooling channels and the distance H2 from the edge of the first plate to the edge of the liquid cooling channel satisfy the following relationship: 0.8 < H2 / L3 < 1.

2.

6. The battery pack according to claim 5, characterized in that, The length of each of the battery cells is 130-300mm, the width is 30-60mm, and the height is 105-140mm.

7. The battery pack according to claim 6, characterized in that, L1-L4 and H1-H3 satisfy the following relationships: 20mm≤L1≤25mm, 13mm≤L2≤16mm, 1.8mm≤L3≤3mm, 8mm≤L4≤12mm, 2mm≤L5≤5mm, 10mm≤H1≤15mm, 1.8mm≤H2≤3mm, 4mm≤H3≤8mm.

8. The battery pack according to claim 7, characterized in that, The total height of the side cold plate is L = L1 + nL2 + (n-1)L3 + L4 + L5, 95mm ≤ L ≤ 120mm; the total width of the side cold plate is H = 2H1 + 2H2 + H3, 20mm ≤ H ≤ 30mm.

9. The battery pack according to claim 1, characterized in that, Each of the battery cells is surrounded by a blue film, and each of the two sides of the blue film of each battery cell has a first window. The first window is coated with thermally conductive adhesive, which is used to bond with the side cold plate. The sum of the adhesive areas on both sides of the battery cell is less than the side area of ​​the battery cell.

10. The battery pack according to claim 1, characterized in that, Each of the battery cells is surrounded by a blue film, and a second window is opened at the end of the blue film of each battery cell. The second window is coated with thermally conductive adhesive, which is used to bond to the upper shell of the battery pack. The area of ​​the adhesive coating at the end of the battery cell is smaller than the end face area of ​​the battery cell.

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