A battery module

Abstract

This invention discloses a battery module, comprising: a housing having a receiving cavity, wherein a battery is disposed in the receiving cavity; a separator disposed between the inner wall of the receiving cavity and the battery, one end of the separator having a first chamber with an opening, the opening of the first chamber having a sealing cap; a first gap cavity communicating with the first chamber being disposed on the bottom wall of the first chamber, the first gap cavity extending along the length direction of the separator and extending along the width direction of the separator, the first gap cavity containing a heat-conducting first fluid, the first fluid being flowable between the first chamber and the first gap cavity; when the separator is in a first state, one end of the separator is disposed near the bottom wall of the receiving cavity, and the first fluid is placed in the first chamber; when the separator is in a second state, the other end of the separator is disposed near the bottom wall of the receiving cavity, and the first fluid is placed in the first gap cavity.

Description

Technical Field

[0001] This invention belongs to the field of battery technology, and specifically relates to a battery module. Background Technology

[0002] With the development of new energy sources, lithium-ion and sodium-ion batteries are increasingly used. Both types of batteries are rechargeable, consisting of a positive electrode, negative electrode, separator, electrolyte, and casing. During charging and discharging, lithium ions or sodium ions repeatedly insert and extract between the two electrodes. During charging, lithium ions or sodium ions are extracted from the positive electrode, pass through the electrolyte, and insert into the negative electrode; the discharge process is the reverse. Lithium-ion batteries primarily use lithium salts as electrode materials, while sodium-ion batteries primarily use sodium salts. Sodium salts are more abundant and cheaper than lithium salts. Sodium-ion batteries exhibit better low-temperature performance, superior rate capability, and higher safety. Sodium-ion batteries are increasingly used as starting power sources in automobile engines, potentially replacing lead-acid batteries and showing promising development prospects. During battery use, heat is generated, leading to a decrease in battery performance. In colder regions, the low temperature of the external environment further degrades battery performance. Therefore, excessively high or low temperatures can reduce battery performance, necessitating measures to mitigate the impact of temperature on battery performance. Summary of the Invention

[0003] The purpose of this invention is to provide a battery module that solves the problem of battery performance degradation caused by excessively high or low temperatures.

[0004] In a first aspect, embodiments of the present invention provide a battery module, comprising: A housing having a receiving cavity; A battery, wherein the battery is disposed in the receiving cavity; A partition is disposed between the inner wall of the receiving cavity and the battery. One end of the partition has a first chamber with an opening, and the opening of the first chamber has a sealing cap. The bottom wall of the first chamber has a first gap cavity communicating with the first chamber. The first gap cavity extends along the length direction of the partition and along the width direction of the partition. The first gap cavity contains a thermally conductive first fluid, which can flow between the first chamber and the first gap cavity. The state of the partition in the receiving cavity can be switched between a first state and a second state. When the partition is in the first state, one end of the partition is disposed near the bottom wall of the receiving cavity, and the first fluid is placed in the first chamber. When the partition is in the second state, the other end of the partition is disposed near the bottom wall of the receiving cavity, and the first fluid is placed in the first gap cavity.

[0005] Furthermore, the first fluid includes at least one of heat-conducting oil and heat-conducting particles.

[0006] Furthermore, both the first inner wall and the second inner wall of the first gap cavity are parallel to the partition.

[0007] Furthermore, the surface of the first inner wall is provided with spaced-apart first pillars, the ends of the first pillars away from the first inner wall being spaced apart from the second inner wall; and / or The surface of the second inner wall is provided with spaced second columns, and the end of the second column away from the second inner wall is spaced apart from the first inner wall.

[0008] Furthermore, the other end of the partition has a second chamber with an opening, the opening of the second chamber having a sealing cap; the bottom wall of the second chamber is provided with a second gap cavity communicating with the second chamber, the second gap cavity extending along the length direction of the partition and the second gap cavity extending along the width direction of the partition, the second gap cavity containing a heat-insulating second fluid, the second fluid being able to flow between the second chamber and the second gap cavity; When the partition is in the first state, one end of the partition is disposed near the bottom wall of the receiving cavity, and the second fluid is placed in the second gap cavity; when the partition is in the second state, the other end of the partition is disposed near the bottom wall of the receiving cavity, and the second fluid is placed in the second chamber.

[0009] Furthermore, the second fluid includes at least one of fine silica aerogel and thermal insulation material particles.

[0010] Furthermore, the third and fourth inner walls of the second gap cavity are both parallel to the partition plate.

[0011] Furthermore, the surface of the third inner wall is provided with spaced-apart third pillars, the end of each third pillar away from the third inner wall being spaced apart from the fourth inner wall; and / or The surface of the fourth inner wall is provided with spaced fourth columns, and the end of the fourth column away from the fourth inner wall is spaced apart from the third inner wall.

[0012] Furthermore, the battery module also includes: An equalization circuit is provided, wherein there are multiple batteries, and each battery is electrically connected to the equalization circuit.

[0013] Furthermore, the number of the receiving cavities is multiple, and each of the receiving cavities is respectively provided with the battery; and / or The shell is made of thermally conductive material, and the partition is made of thermally conductive material.

[0014] In the battery module of this invention, the housing has a receiving cavity, the battery is disposed in the receiving cavity, and a separator is disposed between the inner wall of the receiving cavity and the battery. One end of the separator has a first chamber with an opening, and the opening of the first chamber has a sealing cap. The bottom wall of the first chamber has a first gap cavity communicating with the first chamber. The first gap cavity extends along the length direction of the separator and along the width direction of the separator. The first gap cavity contains a thermally conductive first fluid, which can flow between the first chamber and the first gap cavity. The state of the separator in the receiving cavity can be switched between a first state and a second state. When the separator is in the first state, one end of the separator is disposed near the bottom wall of the receiving cavity, and the first fluid is placed in the first chamber. When the separator is in the second state, the other end of the separator is disposed near the bottom wall of the receiving cavity, and the first fluid is placed in the first gap cavity.

[0015] During use, the separator can be positioned between the inner wall of the receiving cavity and the battery. The separator is removable and can be inserted between the inner wall of the receiving cavity and the battery. One side of the separator can abut against the inner wall of the receiving cavity, and the other side of the separator can abut against the battery. In high-temperature environments, the battery generates a lot of heat that is difficult to dissipate, leading to heat accumulation and reduced battery performance. The separator can be positioned in a second state. In this second state, the other end of the separator is positioned close to the bottom wall of the receiving cavity. A first fluid is placed in the first gap cavity. The first fluid fills the first gap cavity to improve thermal conductivity. The system rapidly dissipates heat generated by the battery to prevent overheating. In low-temperature environments, the battery needs insulation to prevent temperature drops from affecting battery performance. In low-temperature environments, the separator is in its first state, with one end positioned close to the bottom wall of the receiving cavity. A first fluid is placed in the first chamber, and all the first fluid in the first gap cavity can enter the first chamber, creating a near-vacuum state in the first gap cavity. This reduces heat transfer within the first gap cavity, making it less prone to heat loss and minimizing heat transfer between the battery and the external low-temperature environment, thus preventing performance degradation caused by excessively low battery temperatures. Therefore, the state of the separator can be adjusted according to the needs of the external environment, allowing the first fluid within the separator to flow between the first chamber and the first gap cavity. This alters the thermal conductivity of the separator, thereby regulating its heat dissipation performance. This allows the battery to dissipate heat or maintain its temperature as needed, ensuring optimal battery performance. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of a battery module in an embodiment of the present invention; Figure 2This is another structural schematic diagram of the battery module in an embodiment of the present invention; Figure 3 This is a schematic diagram of a partition structure in an embodiment of the present invention; Figure 4 This is another structural schematic diagram of the partition in an embodiment of the present invention; Figure 5 This is another structural schematic diagram of the partition in an embodiment of the present invention; Figure 6 This is another structural schematic diagram of the partition in an embodiment of the present invention; Figure 7 This is a schematic diagram showing the connection between the battery and the equalization circuit. Casing 10; Battery 20; Separator 30; First chamber 31; First gap chamber 32; Second chamber 33; Second gap chamber 34; First column 41; Second column 42; Third column 43; Fourth column 44; Equalization circuit 50. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] like Figures 1 to 6As shown, the battery module of this embodiment includes: a housing 10, a battery 20, and a separator 30. The housing 10 has a receiving cavity, the battery 20 is disposed in the receiving cavity, and the separator 30 is disposed between the inner wall of the receiving cavity and the battery 20. The separator 30 can be disposed between the inner wall of the receiving cavity and the battery 20, and the separator 30 is detachable. The separator 30 can be inserted between the inner wall of the receiving cavity and the battery 20. One side surface of the separator 30 can abut against the inner wall of the receiving cavity, and the other side surface of the separator 30 can abut against the battery 20. One end of the separator 30 has a first chamber 31 with an opening. The opening of the first chamber 31 can have a sealing cover, and the sealing cover is detachable. The bottom wall of the first chamber 31 may be provided with a first gap cavity 32 communicating with the first chamber 31. The first gap cavity 32 may extend along the length direction of the partition 30 and along the width direction of the partition 30. The first gap cavity 32 may contain a thermally conductive first fluid, which can flow between the first chamber 31 and the first gap cavity 32. The thermal conductivity of the partition can be adjusted by the position of the first fluid. The edge of the first gap cavity 32 and the edge of the corresponding partition 30 may be spaced apart by a certain distance, for example, the distance between the edge of the first gap cavity 32 and the edge of the corresponding partition 30 may be 2-10 cm. The first fluid may include at least one of thermally conductive oil, thermally conductive metal particles, and thermally conductive metal powder. The thermal conductivity of the first fluid may be greater than that of the partition material and the shell material.

[0019] The state of the partition 30 within the receiving cavity can switch between a first state and a second state. In the first state, one end of the partition 30 is positioned close to the bottom wall of the receiving cavity, and the first fluid is placed in the first chamber 31. In the second state, the other end of the partition 30 is positioned close to the bottom wall of the receiving cavity, and the first fluid is placed in the first gap cavity 32. For example, when the partition 30 is in the first state, with one end close to the bottom wall of the receiving cavity, the first fluid can be entirely placed in the first chamber 31, resulting in a vacuum or near-vacuum state in the first gap cavity 32. This reduces the thermal conductivity rate in the first gap cavity 32 region, thus decreasing the thermal conductivity effect. When the partition 30 is in the second state, with the other end close to the bottom wall of the receiving cavity, the first fluid can fill the first gap cavity 32 completely, resulting in better thermal conductivity in the first gap cavity 32. The volume of the first chamber 31 can be greater than or equal to the volume of the first gap cavity 32. For example, the volume of the first chamber 31 can be equal to the volume of the first gap cavity 32, or the volume of the first chamber 31 can be 1.05-1.2 times the volume of the first gap cavity 32.

[0020] During use, a separator can be positioned between the inner wall of the receiving cavity and the battery. One side of the separator can abut against the inner wall of the receiving cavity, and the other side of the separator can abut against the battery. In high-temperature environments, the battery generates a lot of heat that is difficult to dissipate, leading to heat accumulation and reduced battery performance. In this second state, the separator's other end is positioned near the bottom wall of the receiving cavity, and a first fluid is placed in the first gap cavity. This first fluid fills the first gap cavity, improving thermal conductivity and allowing for rapid heat dissipation, preventing the battery from overheating. In low-temperature environments, the battery needs insulation to prevent temperature drops from affecting battery performance. In this case, the separator can be positioned in the first state, with one end positioned near the bottom wall of the receiving cavity. A first fluid is placed in the first chamber, allowing all the first fluid in the first gap cavity to enter the first chamber, creating a near-vacuum state. This reduces the heat transfer rate within the first gap cavity, making it less prone to heat loss and minimizing heat transfer between the battery and the external low-temperature environment, thus preventing performance degradation caused by excessively low battery temperatures. Therefore, the state of the separator can be adjusted according to the needs of the external environment, so that the first fluid in the separator can flow in the first chamber and the first gap chamber, thereby changing the heat conduction rate of the separator and adjusting the heat dissipation performance of the separator. Depending on the environmental needs, the battery can be cooled or kept warm to ensure battery performance.

[0021] Optionally, the first fluid includes at least one of heat-conducting oil and heat-conducting particles, and the first fluid is easy to flow.

[0022] In some embodiments of the present invention, the receiving cavity may have a first sidewall, a second sidewall, a third sidewall, and a fourth sidewall. The first and second sidewalls may be arranged parallel and spaced apart, the third and fourth sidewalls may be arranged parallel and spaced apart, and the first and third sidewalls may be arranged perpendicularly. A partition 30 may be disposed between the first sidewall and the battery, and a partition 30 may be disposed between the second sidewall and the battery. Protruding limiting portions 11 may be provided on the surfaces of both the third and fourth sidewalls, and a partition 30 may also be disposed between the limiting portions 11 and the battery. The edge of the partition 30 may be disposed between the first sidewall and the limiting portion 11, and the edge of the partition 30 may be disposed between the second sidewall and the limiting portion 11.

[0023] In some embodiments, the first inner wall and the second inner wall of the first gap cavity 32 may be parallel to the partition 30, and the first gap cavity 32 as a whole may be in the shape of a cuboid or a cube.

[0024] In other embodiments, the surface of the first inner wall may be provided with spaced-apart first pillars 41, with one end of the first pillar 41 away from the first inner wall spaced apart from the second inner wall. The surface of the second inner wall may be provided with spaced-apart second pillars 42, with one end of the second pillar 42 away from the second inner wall spaced apart from the first inner wall. The gap cavity region of the separator 30 may have a certain buffering effect, allowing the gap cavity region of the separator 30 to deform and absorb the deformation generated by the battery when it deforms or collides. The first pillars 41 and second pillars 42 may provide a supporting function, preventing the sidewalls of the first gap cavity 32 from being squeezed by external forces and thus limiting the first gap cavity 32. The separator 30 may have a middle region and an edge region, with the edge region surrounding the middle region. The first gap cavity 32 located in the middle region of the separator 30 serves as the middle gap cavity, and the first gap cavity 32 located in the edge region of the separator 30 serves as the edge gap cavity. The distribution density of the first column 41 located in the middle gap cavity is less than that of the first column 41 located in the edge gap cavity, and the distribution density of the second column 42 located in the middle gap cavity is less than that of the second column 42 located in the edge gap cavity. When the first fluid enters the first gap cavity 32, the middle gap cavity can have more first fluid and a higher thermal conductivity rate. At the same time, the supporting force of the middle region of the separator is less than that of the edge region. The middle region of the separator may correspond to the middle region of the battery wall. When the middle region of the battery expands, the deformation of the middle region of the separator can accommodate the expansion of the battery.

[0025] In an embodiment of the present invention, the other end of the partition 30 may have a second chamber with an opening, the opening of which has a sealing cover that is removable. The bottom wall of the second chamber 33 may have a second gap cavity 34 communicating with it. The second gap cavity 34 may extend along the length of the partition 30 and along the width of the partition 30. The second gap cavity 34 contains a heat-insulating second fluid, which can flow between the second chamber 33 and the second gap cavity 34. The second fluid may include at least one of heat-insulating material particles, fine silica aerogel, silicate insulation powder, and polystyrene particles. The thermal conductivity of the second fluid may be less than that of the partition material and the shell material.

[0026] When the separator 30 is in the first state, one end of the separator 30 is positioned close to the bottom wall of the receiving cavity, and the second fluid is placed in the second gap cavity 34. The second fluid can completely fill the second gap cavity 34, providing heat insulation and reducing heat transfer between the battery and the external environment, preventing the battery performance from being affected by excessively low external temperatures. When the separator 30 is in the second state, the other end of the separator 30 is positioned close to the bottom wall of the receiving cavity, and the second fluid is placed in the second chamber 33. The first fluid is placed in the first gap cavity, and the first fluid filling the first gap cavity improves thermal conductivity, allowing the heat generated by the battery to dissipate quickly and preventing the battery temperature from becoming too high. The width of the second gap cavity 34 in the separator thickness direction can be smaller than the width of the first gap cavity in the separator thickness direction. The width of the second gap cavity 34 in the separator thickness direction can be less than or equal to 1 / 4 to 1 / 2 of the width of the first gap cavity in the separator thickness direction. The second fluid can be fine silica aerogel, which has good heat insulation effect, and a smaller filling thickness can achieve a good heat insulation effect.

[0027] Optionally, the second fluid may include at least one of fine silica aerogel and thermal insulation material particles. For example, the second fluid may include at least one of thermal insulation material particles, fine silica aerogel, silicate thermal insulation powder, and polystyrene granules.

[0028] In some embodiments, the third inner wall and the fourth inner wall of the second gap cavity 34 may be parallel to the partition 30.

[0029] The surface of the third inner wall is provided with spaced-apart third columns 43, with the end of the third column 43 away from the third inner wall spaced apart from the fourth inner wall. The surface of the fourth inner wall is provided with spaced-apart fourth columns 44, with the end of the fourth column 44 away from the fourth inner wall spaced apart from the third inner wall.

[0030] The second gap cavity region of the separator 30 can have a certain buffering effect. When the battery deforms or is impacted, the second gap cavity region of the separator 30 can deform and absorb the deformation generated by the battery. The third column 43 and the fourth column 44 can provide support, prevent the sidewalls of the gap cavity from being squeezed by external forces, and limit the gap cavity. The separator 30 may have a middle region and an edge region, with the edge region surrounding the middle region. The second gap cavity 34 located in the middle region of the separator 30 serves as the middle gap cavity, and the second gap cavity 34 located in the edge region of the separator 30 serves as the edge gap cavity. The distribution density of the third column 43 in the middle gap cavity is less than that in the edge gap cavity, and the distribution density of the fourth column 44 in the middle gap cavity is less than that in the edge gap cavity. When the second fluid enters the second gap cavity 34, the middle gap cavity can have more second fluid, resulting in better heat insulation. At the same time, the supporting force in the middle region of the separator is less than that in the edge region. The middle region of the separator may correspond to the middle region of the battery wall. When the middle region of the battery expands, the deformation of the middle region of the separator can accommodate the expansion of the battery.

[0031] The housing 10 can be made of a thermally conductive material, and the partition 30 can be made of a thermally conductive material. The housing 10 can be made of plastic, and the partition 30 can be made of metal.

[0032] In some embodiments, such as Figure 7 As shown, the battery module may also include: The equalization circuit 50 can accommodate multiple batteries, each electrically connected to the equalization circuit 50. There are also multiple receiving cavities, each housing a battery. Five batteries (batteries C1-C5) can be electrically connected to the equalization circuit 50. For example, the battery module can be used in automotive start-stop power supplies. The battery module can contain five batteries, which can be NFPP sodium-ion batteries. NFPP stands for sodium iron pyrophosphate. Since the highest charging cutoff voltage of an NFPP sodium-ion cell is 3.4V, the lowest discharging cutoff voltage is 1.5V, and the nominal voltage is 2.8V; therefore, the highest charging cutoff voltage of five batteries is 3.4V × 5 = 17V, the lowest discharging cutoff voltage is 1.5V × 5 = 7.5V, and the nominal voltage is 2.8V × 5 = 14V.

[0033] Since the generators in gasoline vehicles typically output voltages around 13.5V-14.5V to charge traditional 12V lead-acid start-stop batteries, the nominal voltage of the five NFPP sodium-ion batteries at 14V falls precisely at the midpoint of the typical 13.5V-14.5V output voltage range of gasoline vehicle generators. NFPP sodium-ion batteries can operate in a comfortable nominal voltage range with shallow charge and discharge for extended periods, more effectively absorbing ripple from the vehicle's electrical system. This makes the entire vehicle's electrical power supply system more stable and efficient, significantly extending the battery pack's lifespan and improving the energy quality of the power supply system.

[0034] The maximum charging cutoff voltage of the five NFPP sodium-ion batteries is 3.4V×5=17V, and the minimum discharging cutoff voltage is 1.5V×5=7.5V, which perfectly matches the wide voltage requirement of 6V~18V in GB / T 28046.2-2019 standard "Environmental conditions and tests for electrical and electronic equipment of road vehicles - Part 2 - Electrical loads". The maximum charging voltage of the 17V five NFPP sodium-ion batteries is 1V lower than the maximum overvoltage of 18V in the GB / T 28046.2-2019 standard. Even with the upper limit of the overvoltage regulation of 18V, it still meets the charging cutoff voltage of 1.15 times the cell pack in "8.1.3" of "Safety Requirements for Power Batteries for Electric Vehicles" in GB 38031-2020, which is 3.4V×5×1.15=19.55V, the upper limit safe voltage value. This is lower than the upper limit safe value of 19.55V-18V=1.55V. Therefore, the five NFPP sodium-ion battery pack can prevent overcharging more effectively than the four NFPP sodium-ion battery pack with a maximum charging voltage of 13.6V, and can achieve a longer life and safety. Compared to the minimum discharge voltage of 7.5V for a 5-cell NFPP sodium-ion battery pack, which is 1.5V higher than the minimum 6V discharge voltage of GB / T28046.2-2019 standard, this effectively avoids the problem of voltage drop and power failure during cold starts at low temperatures and low voltage, providing more sufficient voltage protection for the normal operation of the vehicle's electrical system under low-temperature conditions. In practical use, it better ensures that the battery pack's capacity is not affected by low voltage and cannot discharge, thus avoiding battery capacity loss.

[0035] Due to the excellent start-stop discharge rate of NFPP sodium-ion batteries (above 15C), a 5-cell system can reduce battery pack capacity while maintaining the same total battery capacity and start-stop discharge power. This ensures the start-stop performance and cost advantages of the entire 5-cell NFPP sodium-ion battery system. The capacity adjustment of the 5-cell system can be 75%~85% of that of the 4-cell system. To complement the 5-cell NFPP sodium-ion battery pack, a balancing board can be provided. Considering the specific start-stop conditions of the start-stop power supply, the current and voltage changes caused by the increase or decrease of various vehicle electrical loads and changes in operating conditions, and the need for filtering the generator output voltage, the balancing board needs to have rapid response to battery voltage difference balancing requirements, low power consumption, and high voltage difference accuracy. An active balancing board can be used, with a maximum balancing current of approximately 10% of the battery system capacity, a total system balancing voltage difference of 10mV (not the voltage difference between adjacent cells), a static balancing time of 4~6 hours, and a start and stop balancing voltage of 2.8V minus 0.2V, or 2.6V, the nominal voltage of the cell. The circuit board can be made of aluminum substrate, and the equalization circuit can have better equalization performance, heat resistance, service life and safety.

[0036] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of the present invention.

Claims

1. A battery module, characterized in that, include: A housing having a receiving cavity; A battery, wherein the battery is disposed in the receiving cavity; A partition is disposed between the inner wall of the receiving cavity and the battery. One end of the partition has a first chamber with an opening, and the opening of the first chamber has a sealing cap. The bottom wall of the first chamber has a first gap cavity communicating with the first chamber. The first gap cavity extends along the length direction of the partition and along the width direction of the partition. The first gap cavity contains a thermally conductive first fluid, which can flow between the first chamber and the first gap cavity. The state of the partition in the receiving cavity can be switched between a first state and a second state. When the partition is in the first state, one end of the partition is disposed close to the bottom wall of the receiving cavity, and the first fluid is placed in the first chamber. When the partition is in the second state, the other end of the partition is disposed near the bottom wall of the receiving cavity, and the first fluid is placed in the first gap cavity.

2. The battery module according to claim 1, characterized in that, The first fluid includes at least one of heat-conducting oil and heat-conducting particles.

3. The battery module according to claim 1, characterized in that, The first inner wall and the second inner wall of the first gap cavity are both parallel to the partition.

4. The battery module according to claim 3, characterized in that, The surface of the first inner wall is provided with spaced-apart first pillars, the ends of the first pillars away from the first inner wall being spaced apart from the second inner wall; and / or The surface of the second inner wall is provided with spaced second columns, and the end of the second column away from the second inner wall is spaced apart from the first inner wall.

5. The battery module according to any one of claims 1-4, characterized in that, The other end of the partition has a second chamber with an opening, and the opening of the second chamber has a sealing cover; the bottom wall of the second chamber is provided with a second gap cavity communicating with the second chamber, the second gap cavity extends along the length direction of the partition and extends along the width direction of the partition, and the second gap cavity contains a heat-insulating second fluid, which can flow between the second chamber and the second gap cavity; When the partition is in the first state, one end of the partition is disposed near the bottom wall of the receiving cavity, and the second fluid is placed in the second gap cavity; when the partition is in the second state, the other end of the partition is disposed near the bottom wall of the receiving cavity, and the second fluid is placed in the second chamber.

6. The battery module according to claim 5, characterized in that, The second fluid includes at least one of fine silica aerogel and thermal insulation material particles.

7. The battery module according to claim 5, characterized in that, The third and fourth inner walls of the second gap cavity are both parallel to the partition plate.

8. The battery module according to claim 7, characterized in that, The surface of the third inner wall is provided with spaced-apart third pillars, the ends of the third pillars away from the third inner wall being spaced apart from the fourth inner wall; and / or The surface of the fourth inner wall is provided with spaced fourth columns, and the end of the fourth column away from the fourth inner wall is spaced apart from the third inner wall.

9. The battery module according to claim 1, characterized in that, Also includes: An equalization circuit is provided, wherein there are multiple batteries, and each battery is electrically connected to the equalization circuit.

10. The battery module according to claim 1, characterized in that, The number of the receiving cavities is multiple, and each of the receiving cavities is respectively provided with the battery; and / or The shell is made of thermally conductive material, and the partition is made of thermally conductive material.

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