Battery thermal management device and battery pack

Abstract

The utility model relates to the technical field of battery thermal management, and discloses a battery thermal management device and a battery pack, and the battery thermal management device comprises a plurality of heat pipes, a battery cell and a cooling piece. According to the battery heat management device with the structure, in a cooling mode, a liquid working medium in the evaporation section at the bottom of the heat pipe is heated and evaporated into a gaseous working medium, the gaseous working medium rises to the condensation section at the top of the heat pipe, the gaseous working medium is in contact with a low-temperature wall surface of the condensation section to be condensed into the liquid working medium, and the liquid working medium flows back to the condensation section at the bottom of the heat pipe by gravity; and heat exchange circulation is achieved. The transition section, the condensation section and the evaporation section of the heat pipe are all in contact with the battery cell, so that the heat exchange area is greatly increased, the heat exchange amount is increased, and the cooling effect of the battery cell can be remarkably improved. The arrangement number of the cooling plates can be reduced, so that the arrangement of the cooling pipelines can be simplified, the occupied space of the cooling plates and the cooling pipelines can be reduced, and the volume utilization rate and the mass energy density of the battery thermal management device and the battery pack can be improved.

Description

Technical Field

[0001] This utility model relates to the field of battery thermal management technology, specifically to a battery thermal management device and battery pack. Background Technology

[0002] The current trend in battery pack development is towards higher energy density and faster charging power, with charging time reduced from 30-40 minutes to 15-20 minutes. This increased fast-charging efficiency leads to increased battery heat generation, posing unprecedented challenges to cooling systems. To improve battery pack cooling efficiency, existing technologies employ multi-faceted cooling schemes. These schemes involve numerous cooling plates and complex cooling pipes, increasing the space occupied by the cooling plates and pipes within the battery pack and consequently increasing its weight, thus reducing its volumetric efficiency and mass energy density. Utility Model Content

[0003] In view of this, the present invention provides a battery thermal management device and a battery pack to solve the problems of the large number of cooling plates and the complex cooling pipelines in the cooling scheme of the battery pack in the prior art.

[0004] In a first aspect, this utility model provides a battery thermal management device, comprising:

[0005] Multiple heat pipes, each heat pipe including a transition section, a condensing section and an evaporating section, the condensing section and the evaporating section being disposed opposite each other at the upper and lower ends of the transition section, the condensing section and the evaporating section extending horizontally, both ends of the horizontal extension of the condensing section and the evaporating section extending outwards from the transition section, and adjacent heat pipes being arranged in a row to form an accommodating space between adjacent heat pipes;

[0006] A battery cell is disposed within the receiving space; the outer wall surface of the battery cell is attached to the evaporation section, the transition section, and the condensation section;

[0007] A cooling element is disposed on the top surface of the condensation section, and the cooling element is used to provide a cold source for the condensation section.

[0008] Beneficial Effects: In this battery thermal management device, the cooling element is positioned above the battery cell. Under high-rate fast charging and normal-temperature fast charging conditions, the cell temperature rises, with the lower part of the cell being hotter than the upper part. The high-temperature region at the bottom of the cell transfers heat to the heat pipe. The liquid working fluid in the evaporation section at the bottom of the heat pipe evaporates into a gaseous working fluid. This gaseous working fluid rises to the condensation section at the top of the heat pipe, where it contacts the cooling element. The temperature of the condensation section decreases, and the gaseous working fluid condenses back into a liquid upon contact with the low-temperature wall of the condensation section. The liquid working fluid then flows back to the condensation section at the bottom of the heat pipe by gravity, completing the heat exchange cycle. Since the transition section, condensation section, and evaporation section of the heat pipe all contact the battery cell, the heat exchange area and heat transfer capacity are significantly increased, resulting in a substantial improvement in the cooling effect of the battery cell. Compared to placing cooling plates on multiple sides of the battery cell separately, this design reduces the number of cooling plates required, simplifying the cooling pipe layout and reducing the space occupied by the cooling plates and pipes. This improves the volume utilization and mass energy density of the battery thermal management device and battery pack. In addition, the heat pipe reduces the temperature difference between the high-temperature area at the bottom and the low-temperature area at the top of the cell through evaporation and condensation cycles, thereby reducing the temperature difference of a single cell.

[0009] In one optional embodiment, the two sidewalls of the transition section are vertically arranged, the inner sidewalls of the condensation section and the evaporation section facing the accommodating space are both planar, and the longitudinal section of the accommodating space is rectangular.

[0010] Beneficial effects: The containment space can accommodate a battery cell with a rectangular cross-section, and the heat pipe outside the containment space contacts the four sides of the battery cell, which can significantly increase the heat exchange area of ​​the battery cell and improve heat dissipation efficiency.

[0011] In one alternative embodiment, the ends of the condensing sections of adjacent heat pipes are joined together, and the ends of the evaporating sections of adjacent heat pipes are joined together.

[0012] Beneficial effects: This arrangement allows adjacent heat pipes to form a closed containment space, and allows the entire sidewall of the battery cell to contact the heat pipes, which can significantly increase the heat exchange area and improve the heat dissipation effect.

[0013] In one alternative embodiment, the cooling element includes a direct cooling plate.

[0014] Beneficial effects: Direct cooling has a faster temperature response speed and a lower cooling temperature. It can exchange more heat during the cooling process, thereby significantly reducing the temperature of the battery cell and improving the heat dissipation effect.

[0015] In one alternative embodiment, a heating element is further included, which is disposed on the bottom surface of the evaporation section and is used to provide a heat source to the evaporation section.

[0016] Beneficial effects: In low-temperature fast charging and low-temperature driving conditions, the heating mode is generally activated to heat the battery cell. Heat is supplied to the evaporation section via a heating element. The liquid working fluid in the evaporation section evaporates into a gaseous state and rises to the top of the battery cell where it cools. In low-temperature conditions, since the temperature at the top and bottom of the battery cell is lower than the condensation temperature of the working fluid, condensation occurs almost throughout the entire area where the heat pipe contacts the battery cell. The condensed liquid working fluid flows back to the evaporation section at the bottom by gravity, achieving a heating cycle. The transition section, evaporation section, and condensation section all contact the sidewalls of the battery cell, greatly increasing the heat exchange area and the amount of heat exchanged, thus improving the heating rate of the battery cell. For fast charging, this can effectively shorten the charging time. Furthermore, the heat pipe reduces the temperature difference between the high-temperature area at the top and the low-temperature area at the bottom of the battery cell through evaporation and condensation cycles.

[0017] In one alternative embodiment, the heating element includes a heating film.

[0018] In one alternative embodiment, the cooling element is bonded to the top surface of the condensation section by a thermally conductive structural adhesive;

[0019] And / or, the heating element is bonded to the bottom surface of the evaporation section by a thermally conductive structural adhesive.

[0020] In one alternative embodiment, a bottom protective plate is further included, which is disposed on the bottom surface of the heating element.

[0021] Beneficial effects: The bottom protective plate supports the bottom of the heating film and the battery cell, providing support and protection.

[0022] Secondly, this utility model also provides a battery pack, including the battery thermal management device and the housing described above, wherein the battery thermal management device is disposed within the housing. The battery pack includes the battery thermal management device and has the same technical effects as the battery thermal management device, which will not be elaborated further here.

[0023] In one alternative embodiment, the cooling element is located at the top of the housing.

[0024] Beneficial effects: The cooling component can be directly used as the top cover of the battery pack, which can reduce the size of the battery pack in the height direction, make up for the space occupied by the heat pipe in the height direction of the battery pack, and achieve dimensional balance in the height direction of the battery pack. Attached Figure Description

[0025] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific 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.

[0026] Figure 1 This is a schematic diagram of a battery thermal management device according to an embodiment of the present invention;

[0027] Figure 2 This is a schematic diagram of the interaction between a heat pipe and a battery cell in a battery thermal management device according to an embodiment of the present invention;

[0028] Figure 3 This is a partial cross-sectional view of a battery thermal management device according to an embodiment of the present invention;

[0029] Figure 4 This is a schematic diagram of heat transfer in cooling mode of a battery thermal management device according to an embodiment of the present invention.

[0030] Figure 5 This is a schematic diagram of heat transfer in heating mode for a battery thermal management device according to an embodiment of the present invention.

[0031] Explanation of reference numerals in the attached figures:

[0032] 1. Heat pipe; 11. Transition section; 12. Condensation section; 13. Evaporation section; 2. Battery cell; 3. Cooling component; 4. Heating component; 5. Bottom cover plate. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments 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 protection scope of this utility model.

[0034] The following is combined Figures 1 to 5 The following describes embodiments of the present invention.

[0035] According to an embodiment of the present invention, a battery thermal management device is provided, including a plurality of heat pipes 1, a battery cell 2, and a cooling component 3.

[0036] Each heat pipe 1 includes a transition section 11, a condensing section 12, and an evaporating section 13. The condensing section 12 and the evaporating section 13 are positioned opposite each other at the upper and lower ends of the transition section 11. The condensing section 12 and the evaporating section 13 extend horizontally, with both ends of the horizontal extension of the condensing section 12 and the evaporating section 13 extending outward from the transition section 11. Adjacent heat pipes 1 are arranged in a row to form a receiving space between adjacent heat pipes 1. The battery cell 2 is disposed within the receiving space. The outer wall of the battery cell 2 is attached to the evaporating section 13, the transition section 11, and the condensing section 12. The cooling element 3 is disposed on the top surface of the condensing section 12 and is used to provide a cold source to the condensing section 12.

[0037] In this battery thermal management device, the cooling element 3 is positioned above the battery cell 2. Under high-rate fast charging and normal-temperature fast charging conditions, the temperature of the battery cell 2 rises, and the temperature of the lower part of the battery cell 2 is higher than that of the upper part. Figure 4 As shown in the diagram, the dashed arrows represent the gaseous working fluid, and the solid arrows represent the liquid working fluid. The high-temperature region at the bottom of cell 2 transfers heat to heat pipe 1. The liquid working fluid in the evaporation section 13 at the bottom of heat pipe 1 evaporates into a gaseous working fluid. The gaseous working fluid rises to the condensation section 12 at the top of heat pipe 1. The condensation section 12 contacts the cooling element 3, and its temperature decreases. The gaseous working fluid then condenses into a liquid working fluid upon contact with the low-temperature wall of the condensation section 12. The liquid working fluid flows back to the condensation section 12 at the bottom of heat pipe 1 by gravity, thus achieving a heat exchange cycle. The transition section 11, condensation section 12, and evaporation section 13 of heat pipe 1 all contact cell 2, greatly increasing the heat exchange area and the amount of heat exchanged, which significantly improves the cooling effect of cell 2. Compared to setting cooling plates on multiple sides of cell 2 separately, this method reduces the number of cooling plates, simplifies the arrangement of cooling pipes, and reduces the space occupied by cooling plates and cooling pipes. This is beneficial for improving the volume utilization and mass energy density of the battery thermal management device and battery pack. In addition, heat pipe 1 reduces the temperature difference between the high-temperature area at the bottom and the low-temperature area at the top of cell 2 through evaporation and condensation cycles, thereby reducing the temperature difference of individual cell 2.

[0038] The two side walls of the transition section 11, the inner side walls of the condensation section 12 and the evaporation section 13 contact the outer wall surface of the battery cell 2. Optionally, in some embodiments, the two side walls of the transition section 11 are vertically arranged, and the inner side walls of the condensation section 12 and the evaporation section 13 facing the accommodating space are both planar, so that the longitudinal section of the accommodating space is rectangular. The accommodating space can accommodate the battery cell 2 with a rectangular longitudinal section. The heat pipe 1 outside the accommodating space contacts the four sides of the battery cell 2, which can significantly increase the heat exchange area of ​​the battery cell 2 and improve the heat dissipation efficiency.

[0039] like Figures 1 to 5As shown, the longitudinal section of heat pipe 1 is in the shape of an "I". The ends of the condensing section 12 and the evaporating section 13 extend out of the transition section 11 and are flush. The transition section 11 is located in the middle of the condensing section 12. The transition section 11, the condensing section 12 and the evaporating section 13 are provided with interconnected chambers, and the chambers are filled with an appropriate amount of working fluid.

[0040] In other embodiments, the sidewalls of the transition section 11 can be arc-shaped, the inner sidewalls of the condensing section 12 and the evaporating section 13 facing the receiving space are arc-shaped, the top surface of the condensing section 12 is flat, and the bottom surface of the evaporating section 13 is flat. Correspondingly, the receiving space enclosed by adjacent heat pipes 1 is circular, and a cylindrical battery cell is placed in the receiving space. The heat pipes 1 contact the outer peripheral wall of the cylindrical battery cell, resulting in a large heat exchange area and high heat exchange efficiency.

[0041] In other embodiments, the two side walls of the transition section 11, the inner side walls of the condensation section 12 and the evaporation section 13 facing the containment space may also be in other shapes, and the containment space ultimately formed is adapted to the longitudinal cross-sectional shape of the battery cell 2, so that the transition section 11, the condensation section 12 and the evaporation section 13 can respectively contact the outer wall surface of the battery cell 2.

[0042] In some alternative embodiments, such as Figures 3 to 5 As shown, the ends of the condensing sections 12 of adjacent heat pipes 1 are connected, and the ends of the evaporating sections 13 of adjacent heat pipes 1 are connected, so that the adjacent heat pipes 1 form a closed receiving space, which can make the side wall of the battery cell 2 completely contact the heat pipe 1, significantly increasing the heat exchange area and improving the heat dissipation effect.

[0043] Alternatively, in some embodiments, such as Figure 1 As shown, the cooling component 3 includes a direct cooling plate through which a low-temperature refrigerant flows. The cooling component 3 employs direct cooling instead of liquid cooling. Direct cooling offers a faster temperature response and lower cooling temperature. Compared to the conventional liquid cooling method with a cooling end temperature of approximately 20°C, direct cooling can reduce the cooling end temperature to 5°C–15°C. This allows for greater heat exchange during the cooling process, significantly reducing the temperature of the battery cell 2 and improving heat dissipation.

[0044] In some optional embodiments, the battery thermal management device further includes a heating element 4, which is disposed on the bottom surface of the evaporation section 13 and is used to provide a heat source to the evaporation section 13. Under conditions such as low-temperature fast charging and low-temperature driving, a heating mode is generally activated to heat the battery cell 2. Figure 5As shown, heat is supplied to the evaporation section 13 via the heating element 4. The liquid working fluid in the evaporation section 13 evaporates into a gaseous working fluid upon heating, rising to the top region of the battery cell 2 where it encounters cooling. Under low-temperature conditions, since the temperatures at the top and bottom of the battery cell 2 are both lower than the condensation temperature of the working fluid, condensation occurs almost throughout the entire area where the heat pipe 1 contacts the battery cell 2. The condensed liquid working fluid flows back to the bottom of the evaporation section 13 by gravity, achieving a heating cycle. The transition section 11, evaporation section 13, and condensation section 12 all contact the sidewall of the battery cell 2, greatly increasing the heat exchange area and the amount of heat exchanged, thus improving the heating rate of the battery cell 2. For fast charging, this can effectively shorten the fast charging time. In addition, the heat pipe 1 reduces the temperature difference between the high-temperature region at the top and the low-temperature region at the bottom of the battery cell 2 through the evaporation and condensation cycle.

[0045] Optionally, in some embodiments, the heating element 4 includes a heating film. The heating end provides heat through the heating film, which offers fast heating speed, precise temperature control, and energy saving and environmental protection.

[0046] The battery thermal management device operates in separate cooling and heating modes. When the temperature of cell 2 is greater than 35°C, the battery BMS activates the direct cooling plate, and the battery thermal management device switches to cooling mode; when the temperature of cell 2 is less than 10°C, the battery BMS activates the heating film, and the battery thermal management device switches to heating mode.

[0047] Optionally, in some embodiments, the cooling element 3 is bonded to the top surface of the condensation section 12 by a thermally conductive structural adhesive. This arrangement can improve the thermal conductivity and the overall structural strength of the battery thermal management device.

[0048] The heating element 4 is bonded to the bottom surface of the evaporation section 13 with thermally conductive structural adhesive. This arrangement can improve the thermal conductivity and the overall structural strength of the battery thermal management device.

[0049] In some alternative embodiments, the battery thermal management device further includes a bottom protective plate 5, which is disposed on the bottom surface of the heating element 4. The bottom protective plate 5 supports the bottom of the heating film and the battery cell 2, providing support and protection.

[0050] According to an embodiment of the present invention, another aspect provides a battery pack, including the aforementioned battery thermal management device and a housing, wherein the battery thermal management device is disposed within the housing.

[0051] In this battery pack structure, under high-rate fast charging and normal-temperature fast charging conditions, the temperature of cell 2 rises. The high-temperature region at the bottom of cell 2 transfers heat to heat pipe 1. The liquid working fluid in the evaporation section 13 at the bottom of heat pipe 1 evaporates into a gaseous working fluid. The gaseous working fluid rises to the condensation section 12 at the top of heat pipe 1. The condensation section 12 contacts the cooling element 3, and its temperature decreases. The gaseous working fluid then condenses into a liquid working fluid upon contact with the low-temperature wall of the condensation section 12. The liquid working fluid flows back to the condensation section 12 at the bottom of heat pipe 1 by gravity, achieving a heat exchange cycle. The transition section 11, condensation section 12, and evaporation section 13 of heat pipe 1 all contact cell 2, greatly increasing the heat exchange area and the amount of heat exchanged, thus significantly improving the cooling effect of cell 2. Compared to setting cooling plates on multiple sides of cell 2 separately, this reduces the number of cooling plates, thereby simplifying the arrangement of cooling pipes and reducing the space occupied by cooling plates and cooling pipes. This is beneficial for improving the volume utilization rate and mass energy density of the battery pack. In addition, heat pipe 1 reduces the temperature difference between the high-temperature area at the bottom and the low-temperature area at the top of cell 2 through evaporation and condensation cycles, thereby reducing the temperature difference of individual cells 2 and improving the safety performance of the battery pack.

[0052] In some alternative embodiments, the cooling element 3 is located on the top of the housing, and the cooling element 3 directly serves as the top cover of the battery pack. This can reduce the size of the battery pack in the height direction, make up for the space occupied by the heat pipe 1 in the height direction of the battery pack, and achieve dimensional balance in the height direction of the battery pack.

[0053] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A battery thermal management device, characterized in that, include: Multiple heat pipes, each heat pipe including a transition section, a condensing section and an evaporating section, the condensing section and the evaporating section being disposed opposite each other at the upper and lower ends of the transition section, the condensing section and the evaporating section extending horizontally, both ends of the horizontal extension of the condensing section and the evaporating section extending outwards from the transition section, and adjacent heat pipes being arranged in a row to form an accommodating space between adjacent heat pipes; A battery cell is disposed within the receiving space; the outer wall surface of the battery cell is attached to the evaporation section, the transition section, and the condensation section; A cooling element is disposed on the top surface of the condensation section, and the cooling element is used to provide a cold source for the condensation section.

2. The battery thermal management device according to claim 1, characterized in that, The two side walls of the transition section are vertically arranged, and the inner side walls of the condensation section and the evaporation section facing the containment space are both planar, and the longitudinal section of the containment space is rectangular.

3. The battery thermal management device according to claim 1 or 2, characterized in that, The ends of the condensing sections of adjacent heat pipes are joined together, and the ends of the evaporating sections of adjacent heat pipes are joined together.

4. The battery thermal management device according to claim 1 or 2, characterized in that, The cooling component includes a direct cooling plate.

5. The battery thermal management device according to claim 1 or 2, characterized in that, It also includes a heating element, which is disposed on the bottom surface of the evaporation section and is used to provide a heat source for the evaporation section.

6. The battery thermal management device according to claim 5, characterized in that, The heating element includes a heating film.

7. The battery thermal management device according to claim 5, characterized in that, The cooling component is bonded to the top surface of the condensation section by thermally conductive structural adhesive; And / or, the heating element is bonded to the bottom surface of the evaporation section by a thermally conductive structural adhesive.

8. The battery thermal management device according to claim 5, characterized in that, It also includes a bottom protective plate, which is disposed on the bottom surface of the heating element.

9. A battery pack, characterized in that, The device includes a battery thermal management device and a housing as described in any one of claims 1 to 8, wherein the battery thermal management device is disposed within the housing.

10. The battery pack according to claim 9, characterized in that, The cooling component is located at the top of the housing.

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