Battery module and battery pack

Abstract

The utility model provides a battery module and a battery pack, and the battery module comprises a first shell and a plurality of battery cells, a first liquid flow cavity for cooling liquid to flow through is formed in the first shell, part of the side wall of the battery cell is located in the first liquid flow cavity so as to form heat transfer between the cooling liquid and the battery cell, and the positive electrode end and the negative electrode end of the battery cell penetrate out of the first shell from the two sides respectively. According to the battery module disclosed by the utility model, the first shell with the first liquid flow cavity is arranged, and the partial side wall of the non-electrode end of the battery cell is arranged in the first liquid flow cavity, so that the cooling liquid can be fully contacted with the side wall of the battery cell to directly carry out heat exchange cooling on the battery cell; the cooling efficiency is high by adopting a mode of immersing the side wall of the battery cell in the cooling liquid, and the thermal management performance of the battery module is better.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and particularly relates to a battery module. The utility model also relates to a battery pack provided with the above battery module. Background Art

[0002] Nowadays, with the continuous development of the new energy industry, battery packs, as important energy storage components, have attracted more and more attention from all walks of life. Lithium batteries are widely used in the fields of power and energy storage because of their large energy density, high working voltage, large output power, long charge and discharge cycle life, low self-heat release rate, green, safe and environmentally friendly characteristics. However, heat is generated during the use of the battery. If this part of the heat accumulates in the battery, it is easy to cause thermal runaway and trigger serious safety accidents. Therefore, the thermal management technology of lithium batteries is particularly important in the design of battery modules.

[0003] A battery module usually includes multiple battery cells. During the use of the battery module, the temperature needs to be maintained within a suitable temperature range. In the case of high-rate charging, the battery cells will generate a large amount of heat, and the temperature distribution inside the battery module is very uneven. The increase in temperature will affect the performance of the battery, reduce the service life of the battery cells, and seriously cause thermal runaway, resulting in losses of life and property.

[0004] In common battery modules, the cooling method for battery cells is usually to use a cold plate to cool the battery cells. The battery cells are in contact with the cold plate, and the cold plate uses a liquid cooling method to cool the battery cells. However, nowadays, the charging rate of battery packs is getting higher and higher, and the corresponding heat generated by the battery cells is also very large. It is difficult for the cold plate to effectively cool the battery cells, and the thermal management performance of the battery module is poor. Summary of the Utility Model

[0005] In view of this, the purpose of the present utility model is to propose a battery module to improve the thermal management performance of the battery module.

[0006] To achieve the above object, the technical solution of the present utility model is realized as follows:

[0007] A battery module includes a first housing and multiple battery cells;

[0008] A first liquid flow cavity for the coolant to flow through is provided in the first housing, and part of the side walls of the battery cells are located in the first liquid flow cavity to constitute heat transfer between the coolant and the battery cells. The positive and negative electrodes of the battery cells respectively penetrate through the first housing from both sides.

[0009] Furthermore, a liquid inlet hole and a liquid outlet hole are respectively provided on two opposite sides of the first housing.

[0010] Further, liquid inlet holes and liquid outlet holes are respectively provided on two side walls of the first housing penetrated by the battery cell, so as to guide the coolant to flow through the first liquid flow cavity along the axial direction of the battery cell in the forward or reverse direction.

[0011] Further, second housings are respectively connected to two ends of the first housing, and a structural cavity is formed by enclosing the second housing and the first housing. The positive electrode end and the negative electrode end of the battery cell are respectively located in one of the structural cavities;

[0012] A pipe is inserted into each second housing, and the pipe communicates with the liquid inlet hole or the liquid outlet hole.

[0013] Further, a support body is arranged in each second housing, and the battery cell penetrates and is inserted into the support body;

[0014] In the direction away from the first housing, the support body divides the structural cavity into a second liquid flow cavity close to the first housing and an installation cavity away from the first housing. The liquid inlet hole and the liquid outlet hole both communicate with the adjacent second liquid flow cavity;

[0015] The pipe communicates with the second liquid flow cavity to introduce or discharge the coolant to or from the first liquid flow cavity.

[0016] Further, an inert gas is filled in the installation cavity.

[0017] Further, the battery cells are arranged at intervals, and the liquid inlet holes and the liquid outlet holes are arranged around each battery cell.

[0018] Further, the liquid inlet holes and the liquid outlet holes are arranged in a one-to-one correspondence.

[0019] Further, the area of the outer wall of the battery cell immersed in the coolant is greater than or equal to 60%.

[0020] Compared with the prior art, the present utility model has the following advantages:

[0021] For the battery module of the present utility model, by providing the first housing with the first liquid flow cavity, and arranging part of the side walls of the non-electrode ends of the battery cells in the first liquid flow cavity, the coolant can fully contact the side walls of the battery cells, directly perform heat exchange and cooling on the battery cells. Compared with the cold plate cooling method, the method of immersing the side walls of the battery cells in the coolant has higher cooling efficiency and better thermal management performance of the battery module.

[0022] By respectively arranging the liquid inlet hole and the liquid outlet hole on two opposite sides of the first housing, the coolant can contact the battery cells more fully when flowing in the first liquid flow cavity.

[0023] By providing liquid inlet holes and liquid outlet holes on the two side walls penetrating through the battery cells, it is possible to guide the coolant to flow along the battery cells, making the contact between the coolant and each battery cell more uniform, and the heat dissipation effect on each battery cell more uniform, which is beneficial to improving the overall thermal management performance of the battery module.

[0024] The second housing can cover the electrode ends of the battery cells, playing a role in sealing and protecting the electrode ends, and the pipeline can supply and receive the coolant to and from the first liquid flow chamber.

[0025] The support body can better support the battery cells, improve the installation stability of the battery cells, and divide the structural cavity into a second liquid flow chamber and an installation chamber. The second liquid flow chamber can cooperate with the liquid inlet holes to divide the coolant, or cooperate with the liquid outlet holes to gather the coolant, which is convenient for the management of the coolant; the electrode ends of the battery cells are located in the installation chamber, which is convenient for wiring and arranging electronic components.

[0026] Filling the installation chamber with inert gas can improve the insulation performance of the battery module in the installation chamber, prevent combustion in the installation chamber due to faults, and reduce the oxidation and corrosion of electrical components and battery cells in the installation chamber.

[0027] Spacing the battery cells can improve the utilization rate of the space inside the first housing; arranging the liquid inlet holes and liquid outlet holes around the battery cells can make the coolant contact the battery cells more fully to improve the cooling efficiency.

[0028] Aligning the liquid inlet holes and liquid outlet holes one by one can make the coolant flow more smoothly when passing through the first liquid flow chamber, accelerate the circulation speed of the coolant, and improve the cooling and heat exchange efficiency.

[0029] The immersed area of the battery cells is greater than or equal to 60%, which can enable the coolant to exchange heat with the battery cells more efficiently and improve the thermal management performance of the battery module.

[0030] Another object of the present invention is to provide a battery pack, which is provided with the battery module as described above.

[0031] The battery pack described in the present invention has the same beneficial effects as the battery module described above compared with the prior art, and will not be elaborated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0033] Figure 1 It is a schematic structural diagram of the battery module according to Embodiment 1 of the present invention;

[0034] Figure 2Schematic diagram of the internal structure of the battery module according to Embodiment 1 of the present utility model;

[0035] Figure 3 Schematic diagram of the connection structure between the first housing and the battery cell according to Embodiment 1 of the present utility model;

[0036] Figure 4 Schematic diagram of another perspective of the connection structure between the first housing and the battery cell according to Embodiment 1 of the present utility model.

[0037] Explanation of reference numerals:

[0038] 1. First housing;

[0039] 101. First liquid flow chamber; 102. Liquid inlet hole; 103. Liquid outlet hole;

[0040] 2. Battery cell;

[0041] 3. Second housing;

[0042] 301. Support body;

[0043] 4. Structure chamber;

[0044] 401. Second liquid flow chamber; 402. Installation chamber;

[0045] 5. Pipeline. Detailed implementation manners

[0046] It should be noted that, without conflict, the embodiments in the present utility model and the features in the embodiments may be combined with each other.

[0047] In the description of the present utility model, it should be noted that if terms indicating orientation or positional relationship such as "upper", "lower", "inner", "outer", etc. appear, they are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present utility model. In addition, if terms such as "first", "second", etc. appear, they are also only for descriptive purposes, and

[0048] In addition, in the description of the present utility model, unless otherwise clearly defined, the terms "installation", "connection", "connection", "connection member" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model may be understood in combination with specific situations.

[0049] The present utility model will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0050] Embodiment 1

[0051] This embodiment relates to a battery module to improve the thermal management performance of the battery module.

[0052] In terms of the overall structure, a battery module in this embodiment includes a first housing and a plurality of battery cells.

[0053] A first liquid flow chamber for coolant to flow through is provided in the first housing, and part of the side walls of the battery cells are located in the first liquid flow chamber to constitute heat transfer between the coolant and the battery cells. The positive and negative electrodes of the battery cells respectively penetrate out of the first housing from both sides.

[0054] With the above arrangement, for the battery module in this embodiment, by providing the first housing with the first liquid flow chamber and arranging part of the side walls of the non-electrode ends of the battery cells in the first liquid flow chamber, the coolant can fully contact the side walls of the battery cells and directly exchange heat with the battery cells for cooling. Compared with the cold plate cooling method, the method of submerging the side walls of the battery cells with the coolant has higher cooling efficiency and better thermal management performance of the battery module.

[0055] Based on the above overall introduction, referring to Figures 1 to 4 As shown, specifically, the battery cell 2 in this embodiment uses a cylindrical battery cell, and its positive and negative electrodes are respectively arranged at both ends and penetrate out of the first housing 1. The side wall of the battery cell 2 is hermetically connected to the first housing 1. Of course, it is also possible to use a blade battery cell or a square battery cell for the battery cell 2. Correspondingly, only the two ends of the battery cell 2 need to penetrate out of the first housing 1 and be hermetically connected to the first housing 1. For the shape of the first housing 1, it can be specifically selected according to the usage conditions. In this embodiment, the first housing 1 is a cuboid, and each battery cell 2 is arranged in a "mouth" shape on the first housing 1.

[0056] Among them, a liquid inlet hole 102 and a liquid outlet hole 103 are respectively provided on two opposite sides of the first housing. By respectively arranging the liquid inlet hole 102 and the liquid outlet hole 103 on two opposite sides of the first housing 1, the coolant can contact the battery cell 2 more fully when flowing in the first liquid flow chamber 101.

[0057] Specifically, in order to improve the cooling efficiency of the coolant on the battery cell 2 in the first housing 1, referring to Figure 3 and Figure 4 As shown, liquid inlet holes 102 and liquid outlet holes 103 are respectively provided on the two side walls of the first housing 1 penetrated by the battery cell 2 to guide the coolant to flow through the first liquid flow chamber 101 in the forward or reverse direction along the axis of the battery cell 2. By providing the liquid inlet hole 102 and the liquid outlet hole 103, the coolant can be guided to flow along the battery cell 2, making the contact between the coolant and each battery cell 2 more uniform, and the heat dissipation effect on each battery cell 2 more uniform, which is beneficial to improving the overall thermal management performance of the battery module.

[0058] It should be noted that it is also possible to arrange the liquid inlet hole 102 and the liquid outlet hole 103 at the other opposite ends of the first housing 1. However, in this way of coolant flow, due to the flow direction problem, the colder coolant will first contact the battery cell 2 near the liquid inlet hole 102, and after absorbing a certain amount of heat and rising in temperature, it will then cool other battery cells 2, resulting in a poorer cooling effect of the coolant on other battery cells 2, causing uneven cooling of each battery cell 2, and the cooling effect is not as good as the arrangement of the liquid inlet hole 102 and the liquid outlet hole 103 in this embodiment.

[0059] Specifically, regarding the specific positions of the liquid inlet hole 102 and the liquid outlet hole 103, in this embodiment, the battery cells 2 are arranged at intervals, and the liquid inlet hole 102 and the liquid outlet hole 103 are arranged around each battery cell 2. Arranging each battery cell 2 at intervals can improve the space utilization rate inside the first housing 1, enabling the side walls of each battery cell 2 to be effectively contacted by the coolant to improve the heat exchange efficiency. Arranging the liquid inlet hole 102 and the liquid outlet hole 103 around the battery cell 2 can enable the coolant to evenly enter the periphery of each battery cell 2 when entering the first housing 1, making the coolant more fully contact the battery cell 2 to improve the cooling efficiency.

[0060] Furthermore, in this embodiment, the liquid inlet hole 102 and the liquid outlet hole 103 are directly opposite to each other. The liquid inlet hole 102 and the liquid outlet hole 103 are arranged in paired groups, and the liquid inlet hole 102 and the liquid outlet hole 103 in the same group are directly opposite. When the flow power of the coolant is certain, it can make the flow path of the coolant shorter when flowing through the first liquid flow chamber 101, the flow of the coolant will be smoother, accelerate the flow circulation speed of the coolant, prevent the coolant from overheating after absorbing heat, and improve the cooling heat exchange efficiency of the battery module.

[0061] In addition, in order to ensure that the battery cell 2 is effectively cooled, as shown in Figures 2 to 4 The area of the outer wall of the battery cell 2 immersed in the coolant is greater than or equal to 60%. The area of the outer wall of the battery cell 2 in contact with the coolant is not less than 60%, which can enable sufficient contact between the coolant and the battery cell 2, and at the same time, it can also leave parts at both ends of the motor that are not in contact with the coolant, ensuring that the battery cell 2 does not leak electricity under normal heat dissipation conditions. For the selection of the coolant, the battery module requires special coolants with high temperature resistance, low toxicity, low corrosiveness, low expansibility, etc. Therefore, it is necessary to select an immersion liquid suitable for the battery, such as mineral oil, silicone oil, natural ester, etc.

[0062] As a further enclosure for the battery cell 2, second housings 3 are respectively connected to both ends of the first housing 1. The second housing 3 and the first housing 1 enclose a structural cavity 4, and the positive and negative terminals of the battery cell 2 are respectively located in one structural cavity 4. A pipe 5 is inserted into each second housing 3, and the pipe 5 communicates with the liquid inlet hole 102 or the liquid outlet hole 103. The first housing 1 and the second housing 3 are hermetically connected, so that the structural cavity 4 is relatively enclosed to maintain the isolation of the battery cell 2 from the external environment, to ensure the working environment of the battery cell 2, and at the same time protect the battery cell 2 from being easily collided externally, improving the durability of the battery module. The pipe 5 can supply and receive the coolant to and from the first liquid flow cavity 101.

[0063] For the purpose of improving the installation firmness of the battery cell 2, a support body 301 is provided in each second housing 3, and the battery cell 2 is inserted through the support body 301. The support body 301 can support and fix the battery cell 2, making the connection between the battery cell 2, the first housing 1 and the second housing 3 more firm, and the battery cell 2 is not easily displaced when the battery module is in use.

[0064] Specifically, in the direction away from the first housing 1, the support body 301 divides the structural cavity 4 into a second liquid flow cavity 401 close to the first housing 1 and an installation cavity 402 away from the first housing 1. The liquid inlet hole 102 and the liquid outlet hole 103 both communicate with the adjacent second liquid flow cavity 401. The pipe 5 communicates with the second liquid flow cavity 401 to introduce or export the coolant to and from the first liquid flow cavity 101. In this embodiment, the support body 301 is plate-shaped and parallel to the outer wall of the first housing 1 provided with the liquid inlet hole 102. A rectangular second liquid flow cavity 401 and a rectangular installation cavity 402 are formed in the second housing 3. The second liquid flow cavity 401 adjacent to the liquid inlet hole 102 is used to distribute the coolant to each liquid inlet hole 102 to ensure that each battery cell 2 can fully contact the coolant. The second liquid flow cavity 401 adjacent to the liquid outlet hole 103 is used to gather the coolant flowing out of each liquid outlet hole 103, so as to facilitate the unified delivery of the battery module and facilitate the thermal management of the battery module.

[0065] It should be noted that the pipe 5 can also be directly connected to the first housing 1, so that the pipe 5 communicates with the liquid inlet hole 102 or the liquid outlet hole 103. With such a setting, the two electrode ends of the battery cell 2 can also be not immersed in the coolant, so as to maintain the insulating environment where the electrode ends of the battery cell 2 and the electrical components are located, and facilitate the setting and installation.

[0066] The pipe 5 is used to connect the first liquid flow chamber 101 and the second liquid flow chamber 401 to the coolant circulation pipeline. The coolant circulation pipeline can adopt a common liquid cooling circulation system, so that the coolant with reduced temperature can continuously enter the second liquid flow chamber 401 and the first liquid flow chamber 101. In this embodiment, one end of the pipe 5 is connected to the support body 301, communicating with the second liquid flow chamber 401, and the other end passes through the second housing 3 in the direction away from the first housing 1. The pipes 5 corresponding to the two second housings 3 are coaxially and oppositely arranged, and no liquid inlet hole 102 is provided at the position of the first housing 1 facing the pipe orifice of the pipe 5, so that the coolant will diffuse around after entering the second liquid flow chamber 401, enabling the coolant to enter each liquid inlet hole 102 more evenly and improving the cooling effect of the coolant on the battery cell 2.

[0067] It should be noted that the extending direction of the pipe 5 can be arbitrary and can be arranged according to the actual use environment of the battery module. It still needs to be explained that the pipe 5 can also be connected to the second housing 3, as long as the pipe orifice of the pipe 5 communicates with the second liquid flow chamber 401. However, in this arrangement, after the coolant enters the second liquid flow chamber 401 from one side, the amount flowing into each liquid inlet hole 102 may be uneven, and the effect is not as good as the arrangement of this embodiment.

[0068] The installation cavity 402 in this embodiment is used to accommodate the connection wires or other electrical components at the electrode ends of the battery cell 2, and can provide a space isolated from the coolant, so that the electrical components in the installation cavity 402 are in an environment where leakage is not likely to occur. The installation cavity 402 is located at the end of the battery module, which is also convenient for disassembly and maintenance. A switchable door or window can be provided on the second housing 3 for personnel to operate.

[0069] Secondly, in order to improve the insulation protection level in the installation cavity 402, an inert gas is filled in the installation cavity 402. Filling an inert gas in the installation cavity 402 can improve the insulation performance of the battery module in the installation cavity 402, prevent combustion caused by faults in the installation cavity 402, and reduce the oxidation and corrosion of the electrical components and the battery cell 2 in the installation cavity 402. In this embodiment, nitrogen is selected as the inert gas. Nitrogen is an inert gas with inactive chemical properties and is commonly used in the gas inerting technology of electrical equipment. By injecting nitrogen into the installation cavity 402, the fire and explosion risks inside the installation cavity 402 can be effectively reduced, protecting the safety of equipment and personnel. Of course, the inert gas can also be argon or sulfur hexafluoride gas, as long as it can provide insulation protection for the electrical components in the installation cavity 402.

[0070] For the battery module of this embodiment, the flow path of the coolant is the inlet pipe 5 - the second liquid flow chamber 401 at the inlet end - the liquid inlet hole 102 - the first liquid flow chamber 101 - the liquid outlet hole 103 - the second liquid flow chamber 401 at the outlet end - the outlet pipe 5, that is, the flow path of the coolant circulation path within the battery module. By arranging the battery cells 2 on the first housing 1 and introducing the coolant into the first liquid flow chamber 101 within the first housing 1, the coolant can efficiently cool the battery cells 2, improving the thermal management performance of the battery module.

[0071] Embodiment 2

[0072] This embodiment relates to a battery pack, and this battery pack is provided with the battery module in Embodiment 1.

[0073] By arranging the battery module in Embodiment 1 within this embodiment's battery pack, the coolant can be used to conduct heat exchange cooling for the battery cells in the battery pack. Compared with traditional cold plate refrigeration, it can more efficiently cool the battery cells, improving the overall thermal management performance of the battery pack, reducing the heat generated during the charging and discharging of the battery pack and enabling it to be dissipated in a timely manner, and enhancing the usage quality of the battery pack.

[0074] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A battery module, characterized in that: include: A first housing and a plurality of battery cells; A first liquid flow cavity for coolant to flow through is provided in the first shell, and part of the side wall of the battery cell is located in the first liquid flow cavity to form heat transfer between the coolant and the battery cell, and the positive terminal and the negative terminal of the battery cell respectively pass through the first shell from both sides.

2. The battery module according to claim 1, characterized in that: Two opposite sides of the first shell are respectively provided with a liquid inlet hole and a liquid outlet hole.

3. The battery module according to claim 2, characterized in that: The liquid inlet hole and the liquid outlet hole are respectively provided on the two side walls of the first shell through which the battery core passes, so as to guide the coolant to flow through the first liquid flow cavity in a positive or reverse direction along the axis direction of the battery core.

4. The battery module according to claim 3, characterized in that: The two ends of the first shell are respectively connected to the second shell, the second shell and the first shell form a structural cavity, and the positive terminal and the negative terminal of the battery cell are respectively located in one of the structural cavities; A pipeline is inserted into each of the second shells, and the pipeline is connected to the liquid inlet or the liquid outlet.

5. The battery module according to claim 4, characterized in that: A support body is provided in each of the second shells, and the battery core penetrates and is plugged into the support body; In a direction away from the first shell, the support body divides the structural cavity into a second liquid flow cavity close to the first shell and a mounting cavity away from the first shell, and the liquid inlet hole and the liquid outlet hole are both connected to the adjacent second liquid flow cavity; The pipeline is connected to the second liquid flow cavity to introduce or export the cooling liquid to the first liquid flow cavity.

6. The battery module according to claim 5, characterized in that: The installation cavity is filled with inert gas.

7. The battery module according to claim 2, characterized in that: The battery cells are arranged at intervals, and the liquid inlet holes and the liquid outlet holes are arranged around the battery cells.

8. The battery module according to claim 7, characterized in that: The liquid inlet holes and the liquid outlet holes are directly opposite to each other.

9. The battery module according to any one of claims 1 to 8, characterized in that: The area of ​​the outer wall of the battery core immersed in the coolant is greater than or equal to 60%.

10. A battery pack, characterized in that: The battery pack is provided with a battery module as claimed in any one of claims 1 to 9.

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