Immersed battery system

Abstract

The utility model provides an immersed battery system which comprises a battery module, the battery module comprises a plurality of battery cells, and each battery cell is covered with a thermal shrinkage film; a heat dissipation assembly is arranged on the side wall of the shell, the battery module is arranged in the shell, and an annular gap is formed between the outer side wall of the battery module and the inner side wall of the shell; the annular gap comprises a first annular gap arranged close to the top of the battery module and a second annular gap arranged close to the bottom of the battery module, the first annular gap is filled with a sealant, the second annular gap is filled with a cooling liquid, and the sealant is used for sealing the second annular gap; the battery module is soaked in the cooling liquid, so that heat of the battery module is transferred to the heat dissipation assembly for heat dissipation through the cooling liquid; the battery module can be directly immersed in the cooling liquid, so that the liquid cooling heat dissipation efficiency of the battery module is effectively improved.

Description

Technical Field

[0001] The present application belongs to the field of liquid cooling and heat dissipation technology, and specifically relates to an immersion battery system. Background Art

[0002] Energy storage is an inevitable trend in future development and will play an indispensable role in future power systems. As a forward-looking technology driving future energy development, it will play a significant role in new energy grid integration, electric vehicles, microgrids, home energy storage systems, and grid support services. The core component of energy storage is the lithium-ion battery pack. Lithium-ion batteries are widely used in energy storage packs due to their high power and energy density and long lifespan. However, due to their large size and the significant heat generated during charging and discharging, the accumulated heat in the battery pack increases its temperature, affecting the performance and lifespan of the energy storage battery and even causing thermal runaway.

[0003] Currently, battery systems mainly use indirect liquid cooling, which mainly transfers heat through liquid convection heat exchange. In the process of heat transfer, the liquid needs to flow through complex channels and structures, resulting in large flow resistance, high energy consumption and limited heat dissipation effect. Utility Model Content

[0004] The present application provides an immersion battery system that can directly immerse the battery module in coolant, effectively improving the liquid cooling heat dissipation efficiency of the battery module.

[0005] In order to solve the above technical problems, the present application provides an immersion battery system, comprising:

[0006] A battery module, comprising a plurality of battery cells, each of which is covered with a heat shrink film;

[0007] A housing, wherein a heat dissipation assembly is provided on a side wall of the housing, the battery module is provided in the housing, and an annular gap is provided between the outer side wall of the battery module and the inner side wall of the housing;

[0008] The annular gap includes a first annular gap provided near the top of the battery module and a second annular gap provided near the bottom of the battery module, the first annular gap is filled with a sealant, and the second annular gap is filled with a coolant, and the sealant is used to seal the second annular gap;

[0009] The battery module is immersed in the coolant so that the heat of the battery module is transferred to the heat dissipation component through the coolant for heat dissipation.

[0010] As a further improvement of the present application, a pole and an explosion-proof valve are provided on the top of the battery cell, and the height of the coolant submerging the battery module does not exceed 2 / 3 of the height of the battery module, so that the pole and the explosion-proof valve are exposed above the liquid surface of the coolant.

[0011] As a further improvement of the present application, the heat shrink film covers 4 / 5 of the surface of the battery cell, and the portion of the battery cell covered with the heat shrink film is immersed in the coolant.

[0012] As a further improvement of the present application, a vent hole and a liquid injection hole are provided on the shell, and the vent hole and the liquid injection hole are connected to the second annular gap so that coolant can be filled into the second annular gap through the liquid injection hole.

[0013] As a further improvement of the present application, a plurality of the battery cells are arranged in at least one row in the housing through end plates and connecting plates;

[0014] There are at least two end plates and connecting plates, and the two end plates are arranged on opposite sides of the battery module. Both ends of the connecting plate are respectively connected to the end plates to fasten the plurality of battery cells.

[0015] As a further improvement of the present application, an aluminum bar is provided to connect the tops of two adjacent battery cells.

[0016] As a further improvement of the present application, the heat dissipation assembly is a heat dissipation fin arranged around the outer side wall of the shell.

[0017] As a further improvement of the present application, the coolant is a 50% water-glycol solution, an anhydrous phase change solution, silicone oil or a fluorinated liquid;

[0018] The sealant is polyurethane sealant.

[0019] As a further improvement of the present application, polyurethane foam and epoxy board are filled between two adjacent battery cells.

[0020] As a further improvement of the present application, the height of the second annular gap is greater than the height of the first annular gap.

[0021] Compared with the prior art, the immersed battery system provided in the embodiment of the present application is provided with a first annular gap and a second annular gap between the battery module and the inner wall of the shell. The first annular gap is filled with sealant, and the second annular gap is filled with coolant. The sealant is used to seal the second annular gap, and the battery module is directly immersed in the coolant. A heat dissipation component is provided on the side wall of the shell. The heat generated by the battery module is transferred to the heat dissipation component for heat dissipation through the flow of coolant, which is beneficial to improving the temperature consistency of the battery module, avoiding the impact of excessive temperature difference on the life of the battery cell, reducing the risk of thermal runaway and heat diffusion in the battery system, and effectively improving the safety of the battery system. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0023] Figure 1 A schematic structural diagram of an immersion battery system provided in an embodiment of the present application;

[0024] Figure 2 for Figure 1 Schematic diagram of the structure of the sealant in the immersed battery system shown;

[0025] Figure 3 for Figure 1 Schematic diagram of the structure of the coolant in the immersed battery system shown;

[0026] Description of reference numerals:

[0027] 10-battery module; 11-battery cell; 12-heat shrink film; 13-end plate; 14-connecting plate; 15-aluminum busbar;

[0028] 20 - housing; 21 - heat dissipation assembly; 211 - heat dissipation fins; 22 - sealant; 23 - coolant; 24 - vent; 25 - injection hole; 26 - epoxy board; 27 - polyurethane foam. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of this application more clearly understood, this application is further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0030] In the description of this application, the meaning of "plurality" is at least two, for example, two, three, etc., unless otherwise specifically defined. All directional indications in the embodiments of this application (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship and movement of the components under a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions.

[0031] To provide a more detailed and complete description of the present disclosure, the following provides illustrative descriptions of the embodiments and examples of the present application; however, these descriptions are not intended to be the only ways to implement or use the embodiments of the present application. The embodiments cover features of various embodiments, as well as the method steps and sequences for constructing and operating these embodiments. However, other embodiments may also be used to achieve the same or equivalent functionality and step sequences.

[0032] Please refer to Figure 1-Figure 3 The embodiment of the present application provides an immersion battery system that can directly immerse the battery module in the coolant, effectively improving the liquid cooling heat dissipation efficiency of the battery module.

[0033] Please refer to Figure 1 , is a structural schematic diagram of an immersion battery system provided in an embodiment of the present application, wherein the immersion battery system includes a shell 20 and a battery module 10 arranged inside the shell 20; wherein, the battery module 10 includes a plurality of battery cells 11. Since immersion liquid cooling is a direct contact liquid cooling method, which puts the heating element in direct contact with the coolant 23, the heat dissipation efficiency is higher than that of indirect liquid cooling. Therefore, the present application covers each battery cell 11 with a heat shrink film 12 to play an insulating and waterproof role to prevent the battery cell 11 from leaking electricity, thereby improving the safety performance of the immersion battery system.

[0034] As an optional embodiment, the present application provides a heat dissipation component 21 on the side wall of the shell 20, and the battery module 10 is arranged inside the shell 20 and an annular gap is formed between the battery module 10 and the inner wall of the shell 20. The annular gap includes a first annular gap arranged near the top of the battery module 10, and a second annular gap arranged near the bottom of the battery module 10.

[0035] It can be understood that the battery module 10 includes a top side wall, a bottom side wall and an outer side wall arranged around it. The above-mentioned annular gap refers to the annular gap formed between the outer side wall of the battery module 10 and the inner side wall of the shell 20. The annular gap is divided into a first annular gap and a second annular gap along the direction from the top side wall to the bottom side wall of the battery module 10.

[0036] Further, please refer to Figure 2In this application, sealant 22 is poured into the first annular gap, and coolant 23 is filled in the second annular gap. The coolant 23 arranged in the second annular gap is sealed by the sealant 22 to ensure the airtightness of the shell 20 and the second annular gap and prevent the coolant 23 from overflowing.

[0037] In this application, the battery module 10 is immersed in the coolant 23, the battery module 10 is cooled by the coolant 23 in the second annular gap, and the heat generated by the battery module 10 is transferred to the heat dissipation component 21 provided on the side wall of the shell 20 to achieve heat dissipation. The heat dissipation effect is effectively improved by directly contacting the battery module 10 with the coolant 23.

[0038] It should be noted that the present application achieves heat dissipation of the battery module 10 through the flow of the coolant 23 and heat transfer. Therefore, the coolant 23 can be filled in the second annular gap according to actual needs, and it is not necessary to completely fill the second annular gap, so that the heat generated by the battery module 10 during the charging and discharging process is taken away by the flow of the coolant 23.

[0039] It is understandable that since the top of the battery cell 11 is usually provided with a pole and an explosion-proof valve, the present application sets the height of the coolant 23 to immerse the battery module 10 not exceeding 2 / 3 of the height of the battery module 10, so that the pole and the explosion-proof valve are exposed to the liquid surface of the coolant 23.

[0040] It can also be understood that the liquid level of the coolant 23 is set to no more than 2 / 3 of the height of the battery module 10, thereby ensuring that the pole and the explosion-proof valve are exposed to the liquid surface of the coolant 23; of course, the liquid level of the above-mentioned coolant 23 can also be adjusted accordingly according to actual needs, and this application does not impose further restrictions on this.

[0041] Furthermore, the heat shrink film 12 is arranged to cover 4 / 5 of the surface of the corresponding battery cell 11 , and the portion of the battery cell 11 covered with the heat shrink film 12 is immersed in the coolant 23 .

[0042] Specifically, since a pole and an explosion-proof valve are provided on the top of the battery cell 11, the heat shrink film 12 should cover the bottom of the battery cell 11 and the part of the outer wall of the battery cell 11 immersed in the coolant 23, ensuring that the part of the battery cell 11 immersed in the coolant 23 is wrapped with the corresponding heat shrink film 12.

[0043] Of course, the battery cell 11 can also be subjected to insulation spraying treatment at the position where it is immersed in the coolant 23, and ceramic materials or polymer materials can be selected as the coating, or the insulation and waterproofing of the battery cell 11 can be achieved by combining the above-mentioned heat shrinkable film 12 covering and insulation spraying treatment. This application does not impose too many restrictions on the above-mentioned treatment methods.

[0044] As an optional embodiment, several battery cells 11 are usually arranged to form a battery module 10 and arranged inside the shell 20. In this application, several battery cells 11 are arranged in at least one row through end plates 13 and connecting plates 14 and arranged inside the shell 20.

[0045] For example, please refer to Figure 3 It can be observed that the present application arranges several battery cells 11 into two rows through the end plates 13 and the connecting plates 14 and arranges them inside the shell 20. Of course, they can also be arranged into three rows, four rows, etc. The above arrangement methods are all feasible and the present application does not impose further restrictions on this.

[0046] In the embodiment of the present application, the number of end plates 13 and connecting plates 14 is at least two. The two end plates 13 are arranged on opposite sides of the battery module 10. The size and size of the end plates 13 should be close to or the same as the size of the corresponding side walls of the battery module 10, so that several battery cells 11 are clamped between the two end plates 13. The connecting plate 14 is used to connect the two end plates 13 arranged on opposite sides of the battery module 10, so as to cooperate with the end plates 13 to press and fix several battery cells 11.

[0047] It can be understood that the above-mentioned end plates 13 and connecting plates 14 are arranged around the outer wall of the battery module 10. In principle, the arrangement positions of the end plates 13 and connecting plates 14 should not affect the structures arranged at the top and bottom of the battery module 10, which should be known to those skilled in the art.

[0048] Preferably, the end plate 13 and the connecting plate 14 may be made of stainless steel.

[0049] As an optional embodiment, an aluminum bar 15 is provided at the top of two adjacent battery cells 11. It should be understood that the aluminum bar 15 can connect several battery cells 11 so that several single battery cells 11 can work together. It is usually made of aluminum alloy material with high conductivity and excellent heat dissipation performance. Since aluminum alloy has good conductivity and thermal conductivity, it can effectively transmit current and dissipate heat, effectively dissipate the heat generated by the battery, and ensure the stable operation of the battery module 10.

[0050] Preferably, the present application sets the heat dissipation component 21 as a heat dissipation fin 211 arranged around the outer wall of the shell 20, and sets the shell 20 as a temperature conductive material with heat conduction performance, such as setting the shell 20 to a metal material with a high thermal conductivity coefficient such as copper, aluminum, iron, steel, etc. The present application preferably sets the shell 20 to an aluminum shell 20, so that the heat transferred by the coolant 23 is dissipated to the outside through the heat dissipation fin 211 set on the shell 20.

[0051] Of course, based on the above-mentioned heat dissipation fins 211, common heat dissipation components 21 such as heat dissipation fans can be combined to achieve a better heat dissipation effect, and this application does not impose further restrictions on this.

[0052] Please continue to refer to Figure 3 Since there may be gaps between several battery cells 11, the present application fills and sets polyurethane foam 27 and epoxy board 26 between two adjacent battery cells 11. Adjacent here refers to two adjacent battery cells 11 located in the same column, and also includes the space between two battery cells 11 in adjacent columns. The polyurethane foam 27 and epoxy board 26 can be used to achieve heat insulation and insulation, ensuring that there is enough space for the coolant 23 to flow between the battery cells 11.

[0053] In the embodiment of the present application, the coolant 23 can be set to an ethylene glycol aqueous solution, an anhydrous phase change solution, silicone oil or a fluorinated liquid solution. In actual applications, it is preferably set to a 50% water plus ethylene glycol solution. Of course, other types of coolants 23 can also be selected. As long as it can dissipate heat for the battery module 10 immersed in the coolant 23, other types of coolants 23 selected are also feasible. This application does not make specific restrictions on this.

[0054] In actual production, the battery module 10 and the shell 20 are usually first filled with sealant 22 to ensure the airtightness inside the shell 20, and then the coolant 23 is injected into the second annular gap when it is actually used. Therefore, the present application provides a vent hole 24 and a liquid injection hole 25 connected to the second annular gap on the shell 20, so that the user can fill the coolant 23 into the second annular gap through the liquid injection hole 25.

[0055] It should be noted that, since the housing 20 after potting and glue-packing is equivalent to a closed chamber, it is necessary to provide a vent hole 24 for exhausting airflow, thereby ensuring that liquid can be injected through the injection hole 25 .

[0056] Specifically, an aluminum tube with G1 / 4 pipe thread can be set at the injection hole 25 and the vent hole 24 to facilitate filling the coolant 23 into the second annular gap through the aluminum tube. After the coolant 23 is filled, it can be packaged through a corresponding sealing cover. Of course, the specific model of the pipe thread can also be adjusted according to needs and the aperture size of the injection hole 25 and the vent hole 24. The above methods are all feasible.

[0057] Preferably, the injection hole 25 and the vent hole 24 should be arranged at a position on the shell 20 that is convenient for maintenance operations. In principle, they should be connected to the second annular gap. Any position that can realize the injection of the coolant 23 is feasible. This application does not make further restrictions on this.

[0058] As an optional embodiment, since the heat shrink film 12 covers 4 / 5 of the surface of the battery cell 11, the height of the coolant 23 immersed in the battery module 10 does not exceed 2 / 3 of the height of the battery module 10. Therefore, based on the overall height of the battery module 10, it can be observed that the height of the unimmersed battery module 10 is less than the height of the immersed battery module 10. Therefore, this application stipulates that the height of the second annular gap is greater than the height of the first annular gap.

[0059] For example, the sealant 22 may be polyurethane sealant. Of course, other sealant forms that can achieve a sealing effect are also feasible, and this application does not impose any further restrictions on this.

[0060] The immersed battery system provided in the embodiment of the present application is provided with a first annular gap and a second annular gap between the battery module and the inner wall of the shell. The first annular gap is poured with sealant, and the second annular gap is filled with coolant. The sealant is used to seal the second annular gap, and the battery module is directly immersed in the coolant. A heat dissipation component is provided on the side wall of the shell. The heat generated by the battery module is transferred to the heat dissipation component for heat dissipation through the flow of coolant, which is beneficial to improving the temperature consistency of the battery module, avoiding the impact of excessive temperature difference on the life of the battery cell, reducing the risk of thermal runaway and heat diffusion in the battery system, and effectively improving the safety of the battery system.

[0061] It can be understood that the various technical features of the above embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the various technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0062] The above embodiments are merely exemplary embodiments for illustrating the principles of the present application, but the present application is not limited thereto. Those skilled in the art may make various modifications and improvements without departing from the spirit and substance of the present application, and such modifications and improvements are also considered to be within the scope of protection of the present application.

Claims

1. An immersion battery system, characterized in that: include: A battery module, comprising a plurality of battery cells, each of which is covered with a heat shrink film; A housing, wherein a heat dissipation assembly is provided on a side wall of the housing, the battery module is provided in the housing, and an annular gap is provided between the outer side wall of the battery module and the inner side wall of the housing; The annular gap includes a first annular gap provided near the top of the battery module and a second annular gap provided near the bottom of the battery module, the first annular gap is filled with a sealant, and the second annular gap is filled with a coolant, and the sealant is used to seal the second annular gap; The battery module is immersed in the coolant so that the heat of the battery module is transferred to the heat dissipation component through the coolant for heat dissipation.

2. The submerged battery system according to claim 1, wherein: A pole and an explosion-proof valve are provided on the top of the battery cell, and the height of the battery module immersed in the coolant does not exceed 2 / 3 of the height of the battery module, so that the pole and the explosion-proof valve are exposed above the liquid surface of the coolant.

3. The submerged battery system according to claim 2, wherein: The heat shrink film covers 4 / 5 of the surface of the battery core, and the portion of the battery core covered with the heat shrink film is immersed in the coolant.

4. The submerged battery system according to claim 1, wherein: A vent hole and a liquid injection hole are provided on the shell, and the vent hole and the liquid injection hole are communicated with the second annular gap so that coolant can be filled into the second annular gap through the liquid injection hole.

5. The submerged battery system according to claim 1, wherein: A plurality of the battery cells are arranged in at least one row in the housing through end plates and connecting plates; There are at least two end plates and connecting plates, and the two end plates are arranged on opposite sides of the battery module. Both ends of the connecting plate are respectively connected to the end plates to fasten the plurality of battery cells.

6. The submerged battery system according to claim 5, wherein: An aluminum bar is provided to connect the tops of two adjacent battery cells.

7. The submerged battery system according to claim 1, wherein: The heat dissipation component is a heat dissipation fin arranged around the outer side wall of the shell.

8. The submerged battery system according to claim 1, wherein: The coolant is a 50% water-glycol solution, an anhydrous phase change solution, silicone oil or fluorinated liquid; The sealant is polyurethane sealant.

9. The submerged battery system according to claim 1, wherein: Polyurethane foam and epoxy board are filled between two adjacent battery cells.

10. The submerged battery system according to claim 1, wherein: The height of the second annular gap is greater than the height of the first annular gap.

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