Thermal battery pack and thermal management method

Abstract

The application discloses a heat preservation battery pack, which comprises a battery pack and a heat preservation part. The battery pack comprises a plurality of rows of battery monomers. The heat preservation part is provided with two heat preservation layers. The plurality of rows of battery monomers are arranged on one of the heat preservation layers. The two heat preservation layers are oppositely arranged, and a hollow cavity is arranged between the two heat preservation layers. The hollow cavity is filled with gas to form an air layer, so as to reduce the heat conduction of the two opposite sides of the air layer. Meanwhile, a heat management method based on the heat preservation battery pack is also disclosed, which solves the problem of fast heat loss of the existing battery pack, thereby improving the heat preservation performance of the battery pack.

Description

Technical Field

[0001] This invention relates to the field of batteries, and more particularly to a thermally insulated battery pack and a thermal management method. Background Technology

[0002] A battery pack is composed of multiple battery cells and also includes a battery management system and an electrical system. Battery thermal management is a crucial function of the battery management system, primarily aimed at ensuring the battery pack operates within a suitable temperature range to maintain optimal performance. Battery thermal management mainly includes cooling, heating, and temperature equalization. Cooling and heating functions adjust for the potential impact of external ambient temperature on the battery. Temperature equalization reduces temperature differences within the battery pack, preventing rapid degradation caused by overheating in certain areas.

[0003] In existing battery packs, due to space limitations within the battery housing, it is difficult to ensure effective thermal insulation. When the external ambient temperature is low, although the battery management system provides heat to the battery pack, the pack's insulation performance leads to rapid heat loss. Summary of the Invention

[0004] In order to overcome at least one of the defects described in the prior art, the present invention provides a thermally insulated battery pack, which solves the problem of rapid heat loss in existing battery packs, thereby improving the thermal insulation performance of the battery pack.

[0005] The technical solution adopted by this invention to solve its problem is:

[0006] A thermally insulated battery pack, comprising:

[0007] The battery pack includes several rows of individual battery cells;

[0008] The insulation component has two insulation layers, and several rows of battery cells are disposed on one of the insulation layers. The two insulation layers are disposed opposite to each other, and a hollow cavity is formed between the two insulation layers. The hollow cavity is filled with gas to form an air layer to reduce heat conduction on the two opposite sides of the air layer.

[0009] Furthermore, the insulation component is also provided with a number of positioning openings, the shape and size of each positioning opening being adapted to the shape and size of each battery cell, and each battery cell being installed and fixed inside the positioning opening.

[0010] Furthermore, each of the positioning ports has an insulation ring on its inner wall, and the insulation ring abuts against the end face of the corresponding battery cell.

[0011] Furthermore, the thermally insulated battery pack also includes at least one liquid cooling plate, which is thermally connected to the battery pack.

[0012] Furthermore, several liquid cooling plates are vertically distributed on the insulation component, and each liquid cooling plate is disposed between two adjacent rows of battery cells, and several liquid cooling plates are connected in parallel through liquid cooling pipes.

[0013] Furthermore, the battery cell is a cylindrical cell, and several rows of the battery cells are arranged in an alternating pattern. Each liquid cooling plate is arranged in a wave-like shape so that the peripheral side of each battery cell is in contact with the liquid cooling plate.

[0014] Furthermore, the insulated battery pack also includes a tray frame, on which the insulation component is disposed.

[0015] Furthermore, the insulated battery pack also includes a battery box, and the battery pack, the insulation component, the tray frame, and each of the liquid cooling plates are all installed and fixed inside the battery box.

[0016] Furthermore, the tray frame is provided with a plurality of pressure relief ports, and each battery cell is provided with a corresponding pressure relief port; a pressure relief channel is provided between the tray frame and the battery box, and the inner hole of the insulation ring, the pressure relief port and the pressure relief channel are connected in sequence to guide the hot airflow generated by the battery cell in thermal runaway state to be discharged in an orderly manner to the outside of the battery box.

[0017] Furthermore, the battery box includes a bottom protective plate and a U-shaped outer frame. The inner sidewall of the outer frame is provided with a first step, a second step, and a third step. The first step, the second step, and the third step are sequentially arranged from one of the large surfaces of the outer frame along the height direction of the outer frame. The bottom protective plate is fixed to the first step, and the tray frame is fixed to the third step.

[0018] Furthermore, the pressure relief channel includes a first pressure relief chamber and a second pressure relief chamber. The first pressure relief chamber is formed between the tray frame, the bottom guard plate and the inner sidewall of the second step. The second pressure relief chamber is disposed inside the outer frame. The first pressure relief chamber and the second pressure relief chamber are in communication.

[0019] Furthermore, the insulation component and the inner wall of the outer frame form a temperature-regulating battery compartment, and the battery pack is located inside the temperature-regulating battery compartment.

[0020] This invention also discloses a thermal management method for a battery pack, the specific method of which is as follows:

[0021] The measured temperature value of the monitored battery is compared with the preset temperature for evaluation, so as to adjust the battery's usage status and heat exchange status. The preset temperature ranges from low to high include a first temperature range, a second temperature range, a third temperature range, a fourth temperature range, and a fifth temperature range.

[0022] First state: When the measured temperature value is within the first temperature range, the battery is in a state of not charging and not discharging, and the battery's heat exchange state is in a heating state.

[0023] Second state: When the measured temperature value is within the second temperature range, the battery is in a charging state and the battery's heat exchange state is in a heating state.

[0024] Third state: When the measured temperature value is within the third temperature range, the battery is in a charging state or a discharging state, and the battery's heat exchange state is in a heating state.

[0025] Fourth state: When the measured temperature value is within the fourth temperature range, the battery is in a charging state or a discharging state, and the battery's heat exchange state is neither heating nor cooling.

[0026] Fifth state: When the measured temperature value is within the fifth temperature range, the battery is in a charging state or a discharging state, and the battery's heat exchange state is a cooling state.

[0027] Furthermore, the first temperature range is less than -20℃, the second temperature range is -20℃ to 5℃, the third temperature range is 5℃ to 15℃, the fourth temperature range is 15℃ to 37℃, and the fifth temperature range is greater than 37℃.

[0028] Furthermore, a first termination temperature value is set within the second temperature range. When the measured temperature value is greater than the first termination temperature value, the first state is exited.

[0029] Furthermore, a second termination temperature value is set within the third temperature range. When the measured temperature value is greater than the second termination temperature value, the second state is exited.

[0030] Furthermore, a third termination temperature value is set within the fourth temperature range. When the measured temperature value is greater than the third termination temperature value, the third state is exited.

[0031] Furthermore, a fourth termination temperature value is set within the fourth temperature range. When the measured temperature value is less than the fourth termination temperature value, the system exits the fifth state.

[0032] In summary, the thermal insulation battery pack and thermal management method provided by this invention have the following technical effects:

[0033] By cleverly incorporating an air layer within the insulation component and utilizing the slow thermal conductivity of airflow, heat cannot be rapidly conducted across the sides of the air layer, thus preventing rapid heat loss. This ensures and significantly improves the insulation performance of the battery pack equipped with the insulation component, solving the problem of rapid heat loss in existing battery packs. It also ensures that the battery pack can operate within its optimal temperature range for extended periods, maintaining optimal performance and effectively enhancing the stability of the battery pack. Furthermore, it significantly improves the reliability of electrical devices (such as electric vehicles) using this battery pack. Attached Figure Description

[0034] Figure 1 This is a first overall structural diagram of a thermally insulated battery pack according to a first embodiment of the present invention;

[0035] Figure 2 This is a schematic diagram of the overall assembly of a thermally insulated battery pack according to the first embodiment of the present invention;

[0036] Figure 3 for Figure 2 A magnified view of a portion of point A in the middle;

[0037] Figure 4 for Figure 2 A magnified view of a portion of point B in the middle;

[0038] Figure 5 for Figure 2 A magnified view of a portion of point C in the middle;

[0039] Figure 6 This is a second overall structural diagram of a thermally insulated battery pack according to the first embodiment of the present invention.

[0040] Icons: 1-Battery pack, 11-Battery cell, 2-Insulation component, 21-Insulation layer, 22-Air layer, 23-Positioning port, 24-Insulation ring, 3-Liquid cooling plate, 31-First liquid cooling plate, 32-Second liquid cooling plate, 4-Tray frame, 41-Pressure relief port, 5-Battery box, 51-Outer frame, 511-First step, 512-Second step, 513-Third step, 52-Bottom guard plate, 531-First pressure relief chamber, 532-Second pressure relief chamber, 6-Temperature-regulating battery compartment. Detailed Implementation

[0041] To better understand and implement this invention, the technical solutions in the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings.

[0042] In the description of this invention, it should be noted that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0044] First Embodiment

[0045] In this embodiment, the power battery (lithium-ion power battery) refers to the battery pack 1 and the battery cell 11. The driving range, charging time and safety of the power battery are mainly constrained by the characteristics of the power battery. The characteristics of the power battery are significantly affected by the ambient temperature. Especially in low temperature environments, its usable energy and power decay are more severe. Furthermore, long-term use in low temperature environments will accelerate the aging of the power battery and shorten its service life.

[0046] Commonly used power batteries experience a significant decrease in capacity and operating voltage at -10℃, and their performance deteriorates further at -20℃, resulting in a sharp drop in their usable discharge capacity, which can only maintain about 30% of the specific capacity at room temperature.

[0047] Furthermore, lithium-ion batteries are difficult to charge in low-temperature environments, and metallic lithium tends to accumulate on the negative electrode surface during charging. The growth of lithium dendrites can pierce the battery separator, causing internal short circuits, which not only causes permanent damage to the battery but also induces thermal runaway, significantly reducing its safety.

[0048] To address the issue of heat preservation in power batteries, the inventors have provided a heat-insulating battery pack, specifically combined with... Figure 1 and Figure 2 As shown, in order to clearly show the assembly relationship between the tray frame 4 and the insulation component 2 and the battery box 5, a cross-sectional schematic diagram of the battery box 5 is provided. The insulated battery pack includes the battery box 5 and the battery pack 1, insulation component 2, and tray frame 4 disposed inside the battery box 5. The battery pack 1 includes several rows of battery cells 11.

[0049] As the core of this solution, the insulation component 2 is provided with two insulation layers 21, and several rows of battery cells 11 are all set on one of the insulation layers 21. The two insulation layers 21 are arranged opposite to each other, and a hollow cavity is set between the two insulation layers 21. The hollow cavity is filled with gas to form an air layer 22. The gas referred to here can be air or an inert gas. At this time, the air layer 22 and the two insulation layers 21 form a sandwich structure.

[0050] By utilizing the non-circulating gas inside the hollow cavity and outside the insulation component 2, heat conduction is blocked. That is, the gas inside the hollow cavity has good slow thermal conductivity, which reduces the rate at which the heat-conducting insulation layer 21 with more heat conducts to the other insulation layer 21 with less heat, thereby reducing the heat conduction between the two opposite sides of the air layer 22, thus enhancing the insulation effect of the insulation component 2 and improving its insulation performance.

[0051] It should be noted that this is not limited to the insulation material of insulation component 2. Depending on the usage environment of the battery pack and the needs of electric vehicles, the insulation material of insulation component 2 can be selected from materials with lower thermal conductivity or higher strength. In addition, the insulation material of insulation component 2 can be arranged in different areas according to the heat transfer path to achieve the optimal insulation effect.

[0052] For specific details, please refer to... Figure 1 and Figure 2 As shown, the battery box 5 includes a bottom protective plate 52 and a U-shaped outer frame 51. One large surface of the outer frame 51 is defined as a horizontal plane. The height direction of the outer frame 51 is perpendicular to the horizontal plane. The inner sidewall of the outer frame 51 is provided with a first step 511, a second step 512, and a third step 513 sequentially along the height direction from one side of the horizontal plane. The first step 511, second step 512, and third step 513 are all evenly distributed along the inner periphery of the outer frame 51. The bottom protective plate 52 is embedded inside the outer frame 51 and welded to the first step 511, making the battery box 5 more flat and stable overall. At the same time, it ensures good airtightness of the battery box 5.

[0053] For further details, please refer to [the relevant documentation / reference]. Figure 2 , Figure 4 and Figure 5 As shown, the tray frame 4 is embedded inside the outer frame 51 and is welded and fixed to the third step 513. The insulation component 2 is set on the tray frame 4, that is, the insulation component 2 is supported on the top of the tray frame 4. At this time, the insulation component 2 and the inner side wall of the outer frame 51 form a temperature-regulating battery compartment 6. When the top of the battery box 5 is covered with a box cover, the interior of the temperature-regulating battery compartment 6 forms a relatively sealed space.

[0054] When the temperature of the external environment of the battery box 5 is lower than the temperature inside the temperature-regulating battery compartment 6, that is, the heat inside the temperature-regulating battery compartment 6 is greater than the heat of the external environment of the battery box 5, the heat of each battery cell 11 of the battery pack 1 is also greater than the heat of the external environment of the battery box 5. Since each battery cell 11 is set on the heat insulation component 2, the heat of each battery cell 11 will not be easily conducted directly to the surface of the battery box 5 for diffusion and release.

[0055] Alternatively, when the battery pack is in a low-temperature environment for an extended period, only a small portion of the heat from the individual battery cells 11 is conducted to the surface of the battery case 5 and dissipated through the slow conduction of the air layer 22, thus improving the heat dissipation defect of the battery pack. Furthermore, when the battery pack is in a low-temperature environment for a long time, the battery management system takes optimal thermal management measures within a sufficient timeframe, ensuring that the battery pack 1 remains within its optimal temperature range.

[0056] Similarly, when the temperature of the external environment of the battery box 5 is higher than the temperature inside the temperature-regulating battery compartment 6 (i.e., the heat inside the temperature-regulating battery compartment 6 is less than the heat of the external environment of the battery box 5), the heat of each battery cell 11 in the battery pack 1 is also less than the heat of the external environment of the battery box 5. Thanks to the insulation component 2, the heat from the external environment cannot be directly and quickly transferred to each battery cell 11. Alternatively, if the battery pack is in a high-temperature environment for a prolonged period, the battery management system will take optimal thermal management measures within a sufficient timeframe to ensure that the battery pack 1 remains within its optimal temperature range.

[0057] With the thermal management of the battery pack's own battery management system, the temperature inside the temperature-controlled battery compartment 6 and the temperature of each battery cell 11 are kept in a relatively stable state, thereby ensuring that each battery cell 11 can still be used within the optimal temperature range under external low or high temperature conditions.

[0058] For further details, please refer to... Figure 3 As shown, the insulation component 2 is also provided with a number of positioning holes 23. The shape and size of each positioning hole 23 are adapted to the shape and size of each battery cell 11. Each battery cell 11 is installed and fixed inside the positioning hole 23, that is, the end of each battery cell 11 is inserted into the corresponding positioning hole 23. The shape and size of the insulation component 2 are preferably adapted to the shape and size of the temperature regulating battery compartment 6, so that the insulation component 2 is constrained and fixed inside the temperature regulating battery compartment 6. That is, the bottom surface of the insulation component 2 abuts against the bottom protective plate 52, and the periphery of the insulation component 2 is uniformly surrounded by the periphery of the outer frame 51.

[0059] By cleverly utilizing the rigidity and structural strength of the insulation layer 21, the periphery of each battery cell 11 is evenly stressed onto the sidewall of the positioning port 23. Preferably, the battery cell 11 is a cylindrical cell, and the positioning port 23 is correspondingly set as a circular hole. Thus, the forces on the periphery of the positioning port 23 and the sidewall of the battery cell 11 are both directed towards the central axis of the battery cell 11. That is, the structure of the positioning port 23 and the structural strength of the insulation layer 21 complement each other, effectively ensuring that each battery cell 11 is fixed on the insulation component 2, thereby achieving the unexpected effect of the battery pack 1 being stably installed and fixed in the battery box 5.

[0060] During the insertion and assembly process, the bottom surface of the battery cell 11 will abut against the tray frame 4, and the weight of the battery cell 11 will be directly and entirely supported on the tray frame 4. However, since the battery cell 11 is in direct contact with the tray frame 4, and the tray frame 4 is fixedly connected to the battery box 5, some of the heat from the battery cell 11 will be transferred along the tray frame 4. Ultimately, the heat will be conducted from the tray frame 4 to the battery box 5, which will lead to a small amount of heat loss from the battery pack.

[0061] Regarding the aforementioned problems, the inventor also discloses a further improvement scheme, the details of which can be found in [the relevant documents / properties]. Figure 3 As shown, each positioning port 23 has an insulation ring 24 on its inner sidewall. Specifically, the inner sidewall of the positioning port 23 near the tray frame 4 extends into the positioning port 23 to form the insulation ring 24. The insulation ring 24 is preferably integrally formed with the insulation component 2, and it abuts against the end face of the corresponding battery cell 11. It should be noted that the inner diameter of the insulation ring 24 is determined according to the battery design or design requirements.

[0062] During installation, each battery cell 11 is inserted into the corresponding positioning port 23 until the end of the battery cell 11 abuts against the heat insulation ring 24. This not only allows each battery cell 11 to act directly on the heat insulation ring 24, preventing the battery cell 11 from colliding with the tray frame 4, but more importantly, the heat insulation ring 24 separates the battery cell 11 from the tray frame 4, thereby preventing the heat of the battery cell 11 from being directly transferred to the tray frame 4, effectively solving the problem of heat loss from the battery cell 11 along the tray frame 4.

[0063] For further details, please refer to... Figure 3 As shown, the tray frame 4 is provided with several pressure relief ports 41. Each battery cell 11 is correspondingly provided with each pressure relief port 41. When any battery cell 11 experiences thermal runaway, the high temperature and high pressure airflow generated by the battery cell 11 flows from the end of the battery cell 11 through the inner hole of the heat preservation ring 24 and the pressure relief port 41 in sequence, and finally flows out from the pressure relief port 41.

[0064] It should be added that the pressure relief port 41 is preferably a through hole, which can be formed by punching, resulting in a simple and low-cost process. The diameter of the through hole is preferably equal to the inner diameter of the insulation ring 24, but it can also be larger than the inner diameter of the insulation ring 24. Furthermore, the pressure relief port 41 can also be a countersunk hole or a recessed hole. The inner diameter of the countersunk hole or recessed hole is preferably equal to the inner diameter of the insulation ring 24, but it can also be larger than the inner diameter of the insulation ring 24. Of course, the pressure relief port 41 can also be a groove structure with a through hole, the diameter of which is equal to or larger than the inner diameter of the insulation ring 24.

[0065] When the size of the pressure relief port 41 is larger than the inner diameter of the insulation ring 24, the side of the insulation ring 24 near the pressure relief port 41 can extend into the pressure relief port 41 along the central axis of the insulation ring 24 to form a protruding structure (not shown in the figure). The shape and size of the protruding structure are adapted to the shape and size of the pressure relief port 41, or an assembly tolerance is maintained between the protruding structure and the pressure relief port 41.

[0066] In the above, please refer to the specific details. Figure 3 , Figure 4 and Figure 5 As shown, a pressure relief channel is provided between the tray frame 4 and the battery box 5. The pressure relief channel includes a first pressure relief cavity 531 formed between the tray frame 4, the bottom protective plate 52 and the inner side wall of the outer frame 51, that is, the first pressure relief cavity 531 is formed between the tray frame 4, the bottom protective plate 52 and the inner side wall of the second step 512, and a second pressure relief cavity 532 provided inside the outer frame 51. The outer frame 51 is also provided with at least one connecting port and at least one exhaust port (not shown in the figure). The second pressure relief cavity 532 is connected to the first pressure relief cavity 531 through at least one connecting port, and the second pressure relief cavity 532 is connected to the external environment of the battery box 5 through at least one exhaust port.

[0067] Therefore, when any battery cell 11 is in a state of thermal runaway, the high-temperature and high-pressure gas (hot gas flow) released by the battery cell 11 is output to the first pressure relief chamber 531 through the inner hole of the heat preservation ring 24 and the pressure relief port 41 on the tray frame 4. Under the guidance of the first pressure relief chamber 531, the high-temperature and high-pressure gas flows to the inside of the second pressure relief chamber 532 through the connecting port. Finally, the high-temperature and high-pressure gas flows directionally along the second pressure relief chamber 532 to the exhaust port and is discharged to the outside of the battery box 5, thereby achieving the effect of guiding the hot gas flow generated by the battery cell 11 in the state of thermal runaway to be discharged to the outside of the battery box 5 in an orderly manner.

[0068] Unexpectedly, through the cooperation of the insulation ring 24 of the insulation component 2, the pressure relief port 41 of the tray frame 4, the second pressure relief chamber 532 of the outer frame 51, and the first pressure relief chamber 531 set between the bottom guard plate 52 and the tray frame 4, the high-temperature and high-pressure gas will not be directly discharged into the temperature-regulating battery compartment 6 and diffuse. This ensures that the other battery cells 11 of the battery pack 1 are less affected or even avoided by the high-temperature and high-pressure airflow. This avoids the problem of heat spread caused by the hot airflow generated by any battery cell 11 of the battery pack 1 in the case of thermal runaway due to irregular diffusion in the temperature-regulating battery compartment 6. This reduces the degree of impact of thermal runaway on the battery pack 1 and improves the stability of the battery pack during use.

[0069] When a single battery cell 11 or the battery pack 1 is in a state of thermal runaway, or when a single battery cell 11 is overcharged or over-discharged, the temperature of the single battery cell 11 will rise significantly. Since the battery pack 1 is mainly composed of multiple single battery cells 11, if any single battery cell 11 does not dissipate heat in time when its temperature rises, heat will accumulate. Furthermore, since the battery pack 1 is installed and fixed in a relatively closed temperature-regulating battery compartment 6, the temperature of the temperature-regulating battery compartment 6 can easily rise rapidly.

[0070] To prevent the temperature of the battery pack 1 or the temperature-regulating battery compartment 6 from rising and affecting the performance of each individual battery cell 11, the inventors proposed a further improvement, specifically combining... Figure 1 , Figure 2 and Figure 6 As shown, a liquid cooling plate 3 is installed inside the battery box 5, that is, a liquid cooling plate 3 is installed inside the temperature-regulating battery compartment 6, and the liquid cooling plate 3 is thermally connected to the battery pack 1.

[0071] The heat exchange medium (such as water) is then supplied to the interior of the liquid cooling plate 3. Due to the temperature difference between the heat exchange medium and the temperature-regulating battery compartment 6, especially when the battery cell 11 is in thermal runaway, i.e. the temperature of the battery pack 1 is higher than the temperature of the battery cell 11, the heat of the battery pack 1 is transferred to the heat exchange medium of the liquid cooling plate 3 and discharged from the battery pack in time with the flow of the heat exchange medium. Thus, heat exchange is formed between the liquid cooling plate 3 and the battery pack 1, effectively dissipating heat from the battery pack 1 in a timely and real-time manner, thereby effectively avoiding the risk of thermal runaway and heat spread of the battery pack 1.

[0072] It should be noted that the liquid cooling plate 3 can be disposed on the top of the battery pack 1, or it can be disposed on the periphery of the battery cell 11. Here, the liquid cooling plate 3 disposed on the top of the battery pack 1 is defined as the first liquid cooling plate 31, and the liquid cooling plate disposed on the periphery of the battery cell 11 of the battery pack 1 is defined as the second liquid cooling plate 32. This is only for the purpose of distinguishing the position of the liquid cooling plate 3 in the following text, and is not intended to limit the difference in their structure.

[0073] The number of liquid cooling plates 3 can be one. To ensure that each battery cell 11 can exchange heat with the liquid cooling plate 3 and achieve the purpose of heat dissipation and cooling for each battery cell 11, the specific method is based on... Figure 6 As shown, the first liquid cooling plate 31 is distributed parallel to the insulation member 2 and disposed on the top of the battery pack 1, and the first liquid cooling plate 31 covers at least each battery cell 11, so that the heat released by each battery cell 11 can be conducted from the top of the battery cell 11 to the first liquid cooling plate 31. In addition to covering the battery pack 1, the first liquid cooling plate 31 can also cover the temperature-regulating battery compartment 6, so that the heat inside the temperature-regulating battery compartment 6 can be transferred to the first liquid cooling plate 31.

[0074] Preferably, the number of second liquid cooling plates 32 can also be a plurality of second liquid cooling plates 32, specifically according to... Figure 1 and Figure 2 As shown, several second liquid cooling plates 32 are vertically distributed on the insulation component 2, and each second liquid cooling plate 32 is disposed between two adjacent rows of battery cells 11, that is, the large surface of the second liquid cooling plate 32 is in contact with the periphery of the battery cell 11, which increases the heat exchange surface between the second liquid cooling plate 32 and the battery cell 11, thereby effectively ensuring that the heat of the battery cell 11 can be quickly conducted to the second liquid cooling plate 32, thereby improving the heat dissipation capacity of the battery pack.

[0075] Specifically based on Figure 1 and Figure 2 As shown, several of the aforementioned second liquid cooling plates 32 are connected in parallel via liquid cooling pipes. When heat exchange medium is simultaneously supplied to each second liquid cooling plate 32, both rows of battery cells 11 on opposite sides of the second liquid cooling plate 32 can conduct heat to the second liquid cooling plate 32, thereby achieving the purpose of simultaneous and balanced heat dissipation for both rows of battery cells 11. That is, each row of battery cells 11 can be used at the optimal ambient temperature. At the same time, the second liquid cooling plates 32, which are fixed between the two rows of battery cells 11, can also effectively reduce the overall volume of the battery pack. In addition, since the externally supplied heat exchange medium is diverted through multiple second liquid cooling plates 32, an unexpected effect of reducing the flow resistance of the battery's liquid cooling system is achieved.

[0076] Furthermore, based on specific circumstances Figure 1 and Figure 2As shown, since the battery cell 11 is preferably a cylindrical cell, the sidewall of the battery cell 11 is curved. To make the assembly of several battery cells 11 more compact, several rows of battery cells 11 are arranged in an alternating pattern. At the same time, each second liquid cooling plate 32 is arranged in a wave-like shape, and the peripheral side of each battery cell 11 is in contact with the second liquid cooling plate 32. That is, each second liquid cooling plate 32 has multiple arc-shaped troughs, and each battery cell 11 is correspondingly abutted and attached to the corresponding trough. The shape and size of each trough are preferably adapted to the shape and size of the battery cell 11, so that the heat exchange area between the battery cell 11 and the second liquid cooling plate 32 is larger, thereby maximizing the heat exchange efficiency of the battery cells 11 in the battery pack 1 and achieving the best heat dissipation effect.

[0077] Second Embodiment

[0078] The first embodiment described above discloses a thermally insulated battery pack with good thermal insulation performance. At the same time, the thermally insulated battery pack, combined with the liquid cooling plate 3, can also provide good heat dissipation, thereby solving the problem of the contradiction between thermal insulation and heat dissipation in existing battery packs, so that thermal insulation and heat dissipation are maintained in a relatively balanced relationship, thereby ensuring that the thermally insulated battery pack is in the best working state, and improving the stability and reliability of the thermally insulated battery pack and the power-consuming device using the battery pack.

[0079] Based on the thermal insulation battery pack disclosed in the first embodiment, the inventors also disclosed a thermal management method, which compares and evaluates the measured temperature value of the monitored battery with a preset temperature in order to adjust the battery's usage state and heat exchange state. The preset temperature includes a first temperature range, a second temperature range, a third temperature range, a fourth temperature range, and a fifth temperature range from low to high.

[0080] First state: When the measured temperature value is within the first temperature range, the battery is in a state of not charging and not discharging, and the battery's heat exchange state is in a heating state.

[0081] Second state: When the measured temperature value is in the second temperature range, the battery is in the charging state and the battery's heat exchange state is in the heating state.

[0082] Third state: When the measured temperature value is in the third temperature range, the battery is in either charging or discharging state, and the battery's heat exchange state is in heating state.

[0083] Fourth state: When the measured temperature value is in the fourth temperature range, the battery is in either charging or discharging state, and the battery's heat exchange state is neither heating nor cooling.

[0084] Fifth state: When the measured temperature value is in the fifth temperature range, the battery is in either charging or discharging state, and the battery's heat exchange state is cooling state.

[0085] It should be noted that the measured temperature value of the monitored battery here can be the temperature of the single battery cell 11 of the monitored battery, or the temperature of the monitored battery pack 1, or the temperature of the monitored battery box 5. Of course, it can be the temperature of any two or all three of them combined.

[0086] In this embodiment, the first temperature range is within the lowest temperature range. Considering that the performance of the power battery deteriorates rapidly when the temperature is below -20°C, preferably, the first temperature range is less than -20°C. Within this temperature range, to achieve the best purpose of protecting the battery, the battery cell 11 is in a state of stopping charge and discharge. Combining with the thermal management in the battery management system, the heated heat exchange medium is controlled to be delivered to the liquid cooling plate 3, so that the heat of the heat exchange medium can be effectively transferred to each battery cell 11, thereby achieving the purpose of preheating and thawing the battery cell 11. At the same time, under the action of the heat preservation member 2, the problem that the heat supplied to the battery cell 11 is conducted to the battery box 5 and causes loss can be effectively avoided, and the battery pack can also be quickly adjusted and restored to the optimal temperature range.

[0087] Through long-term research and experiments in the battery field, it is found that when the power battery operates within the range of 15°C - 35°C (or 15°C - 37°C), it can achieve the best power output and input, the maximum available energy, and the longest cycle life. Therefore, when the temperature of the battery recovers from below -20°C to above -20°C, the battery can be appropriately charged.

[0088] According to the surface distribution diagram of the relationship between battery performance and temperature, after the battery is preheated and thawed to -20°C, as the temperature rises, the battery performance gradually improves. Preferably, taking the intermediate value of 5°C between the temperature ranges of -20°C to 15°C, the temperature range of -20°C to 15°C is divided into a second temperature range of -20°C - 5°C and a third temperature range of 5°C - 15°C, and the battery is charged within the second temperature range.

[0089] When the temperature enters the third temperature range, the user can appropriately select the usage state of the battery according to the usage environment of the battery pack. To enable the battery to obtain the best battery performance within the optimal temperature range and ensure the longest service life of the battery, in the second temperature range and the third temperature range, the thermal management in the battery management system continuously controls the heated heat exchange medium to be delivered to the liquid cooling plate 3 to continuously supply heat to the battery pack 1.

[0090] It should be noted that the temperature is between -20°C and 15°C but not limited to 5°C, and it can also be 0°C, etc., as long as the temperature range of -20°C to 15°C can be relatively evenly divided into two temperature ranges.

[0091] Preferably, the fourth temperature range is set to 15°C - 37°C. That is, when the first temperature range is within the optimal temperature range, at this time, the battery does not need to continuously supply heat actively, that is, the heating of the battery cell 11 is stopped. Only by using the heat generated during the use of the battery cell 11 and the heat stored in the heat exchange medium inside the liquid cooling plate 3 can the battery be in a relatively stable temperature range, that is, the battery can maintain the best performance.

[0092] Furthermore, when the temperature of the battery exceeds 37°C, that is, the fifth temperature range is greater than 37°C. At this time, the fifth temperature range is within a relatively high temperature range. At this time, the battery performance will be gradually affected by the high temperature. That is, after the battery enters the fifth temperature range, as the temperature rises, the electromagnetic performance gradually decreases. Therefore, after the battery enters the fifth temperature range, it needs to be cooled while in use. Combining with the thermal management in the battery management system, the low-temperature heat exchange medium is controlled to be输送至液冷板3, then the heat of each battery cell 11 will be transferred to the heat exchange medium and finally output from the battery pack with the heat exchange medium, so as to achieve the effect of efficient heat dissipation of the battery through the liquid cooling plate 3.

[0093] Meanwhile, under the action of the heat preservation member 2, it can effectively prevent the heat outside the battery box 5 from being less or even unable to be conducted to the battery pack 1 inside the battery box 5, so as to quickly restore the battery pack 1 to the optimal temperature range, and then ensure that the battery pack can maintain the best battery performance for a long time.

[0094] Furthermore, a first termination temperature value is also set within the second temperature range. When the measured temperature value is greater than the first termination temperature value, the first state is exited. Preferably, the measured temperature value is set to -15°C or -10°C. The battery performance drops sharply at -10°C. Then when the measured temperature value recovers and is greater than -10°C, the battery performance basically recovers, and the first state is exited.

[0095] Furthermore, a second termination temperature value is also set within the third temperature range. When the measured temperature value is greater than the second termination temperature value, the second state is exited. Preferably, the measured temperature value is set to 10°C. A third termination temperature value is also set within the fourth temperature range. When the measured temperature value is greater than the third termination temperature value, the third state is exited. Preferably, the measured temperature value is set to 20°C.

[0096] That is, the thermal management in the battery management system continuously controls the heated heat exchange medium to be输送至液冷板3 until the measured temperature value is 20°C. At this time, the temperature of the battery is within the fourth temperature range of 15°C - 37°C, so as to ensure that the battery maintains a dynamic balance within the fourth temperature range, and thus avoid the problem that the battery temperature drops below 15°C after the heat supply stops when the battery temperature reaches 15°C, resulting in the battery performance not being within the best performance range, effectively improving the stability of the battery pack.

[0097] Furthermore, a fourth termination temperature value is also set within the fourth temperature range. When the measured temperature value is less than the fourth termination temperature value, the fifth state is exited. Preferably, the fourth termination temperature value is greater than the third termination temperature value, and the measured temperature value is set to 33°C. That is, the heat management in the battery management system continuously controls the heat exchange medium after cooling to be delivered to the liquid cooling plate 3 until the measured temperature value reaches 33°C. At this time, the temperature of the battery is within the fourth temperature range of 15°C - 37°C, thereby ensuring that the battery maintains a dynamic balance within the fourth temperature range, and avoiding the problem that the temperature of the battery rises above 37°C after stopping cooling when the temperature of the battery reaches 37°C, which may cause the battery performance not to be within the range of the best performance. Furthermore, the stability of the battery pack is effectively improved.

[0098] Based on the above, the above temperatures are divided into multiple temperature ranges based on the temperature value with the best battery performance and the low-temperature mutation value of the battery performance, making the temperature control range of the battery heat management more reasonable. By using the first termination temperature value, the second termination temperature value, the third termination temperature value, and the fourth termination temperature value, the problem of frequent on and off of the heat management in the battery management system can be effectively avoided.

[0099] More importantly, by using the heat management method in combination with the heat preservation member 2 and the liquid cooling plate 3, the heat preservation performance and heat dissipation performance of the battery pack can be effectively improved. At the same time, it can also ensure that the battery pack and the electrical device (such as an electric vehicle, etc.) are better in a balanced state of heat supply and heat dissipation and maintain the best performance state, greatly improving the stability and reliability of the battery pack and the electrical device.

[0100] The technical means disclosed in the solution of the present invention are not limited to the technical means disclosed in the above embodiments, but also include technical solutions composed of any combination of the above technical features. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements are also regarded as the protection scope of the present invention.

Claims

1. A thermally insulated battery pack, characterized in that, include: Battery pack (1), the battery pack (1) includes several rows of battery cells (11); The insulation component (2) has two insulation layers (21) and several rows of battery cells (11) are disposed on one of the insulation layers (21). The two insulation layers (21) are disposed opposite to each other and a hollow cavity is formed between the two insulation layers (21). The hollow cavity is filled with gas to form an air layer (22) to reduce heat conduction on the two opposite sides of the air layer (22). The heat insulation component (2) is also provided with a number of positioning ports (23), the shape and size of each positioning port (23) are adapted to the shape and size of each battery cell (11), and each battery cell (11) is installed and fixed inside the positioning port (23). Each of the positioning ports (23) is provided with a heat-insulating ring (24) on its inner sidewall, and the heat-insulating ring (24) abuts against the end face of the corresponding battery cell (11); It also includes a tray frame (4), on which the insulation component (2) is disposed.

2. The thermally insulated battery pack according to claim 1, characterized in that: It also includes at least one liquid cooling plate (3), and at least one of the liquid cooling plates (3) is thermally connected to the battery pack (1).

3. The thermal insulation battery pack according to claim 2, characterized in that: Several liquid cooling plates (3) are vertically distributed on the insulation component (2), and each liquid cooling plate (3) is disposed between two adjacent rows of battery cells (11). Several liquid cooling plates (3) are connected in parallel through liquid cooling pipes.

4. The thermally insulated battery pack according to claim 3, characterized in that: The battery cell (11) is a cylindrical cell, and several rows of battery cells (11) are arranged in an alternating pattern. Each liquid cooling plate (3) is arranged in a wave shape so that the peripheral side of each battery cell (11) is in contact with the liquid cooling plate (3).

5. The thermally insulated battery pack according to claim 2, characterized in that: It also includes a battery box (5), in which the battery pack (1), the insulation component (2), the tray frame (4) and each of the liquid cooling plates (3) are installed and fixed inside the battery box (5).

6. The thermally insulated battery pack according to claim 5, characterized in that: The tray frame (4) is provided with a plurality of pressure relief ports (41), and each battery cell (11) is provided with a corresponding pressure relief port (41); A pressure relief channel is provided between the tray frame (4) and the battery box (5). The inner hole of the heat preservation ring (24), the pressure relief port (41) and the pressure relief channel are connected in sequence to guide the hot air flow generated by the battery cell (11) in thermal runaway state to the outside of the battery box (5).

7. The thermally insulated battery pack according to claim 6, characterized in that: The battery box (5) includes a bottom protective plate (52) and a U-shaped outer frame (51). The inner sidewall of the outer frame (51) is provided with a first step (511), a second step (512) and a third step (513). The first step (511), the second step (512) and the third step (513) are arranged sequentially from one of the large surfaces of the outer frame (51) along the height direction of the outer frame (51). The bottom protective plate (52) is fixed to the first step (511) and the tray frame (4) is fixed to the third step (513).

8. The thermally insulated battery pack according to claim 7, characterized in that: The pressure relief channel includes a first pressure relief chamber (531) and a second pressure relief chamber (532). The first pressure relief chamber (531) is formed between the inner wall of the tray frame (4), the bottom guard plate (52) and the second step (512). The second pressure relief chamber (532) is disposed inside the outer frame (51). The first pressure relief chamber (531) and the second pressure relief chamber (532) are in communication.

9. The thermally insulated battery pack according to claim 7, characterized in that: The insulation component (2) and the inner wall of the outer frame (51) form a temperature-regulating battery compartment (6), and the battery pack (1) is located inside the temperature-regulating battery compartment (6).

10. A thermal management method, characterized in that: For use in the thermally insulated battery pack as described in any one of claims 1 to 9, comprising: The measured temperature value of the monitored battery is compared with the preset temperature for evaluation, so as to adjust the battery's usage status and heat exchange status. The preset temperature ranges from low to high include a first temperature range, a second temperature range, a third temperature range, a fourth temperature range, and a fifth temperature range. First state: When the measured temperature value is within the first temperature range, the battery is in a state of not charging and not discharging, and the battery's heat exchange state is in a heating state. Second state: When the measured temperature value is within the second temperature range, the battery is in a charging state and the battery's heat exchange state is in a heating state. Third state: When the measured temperature value is within the third temperature range, the battery is in a charging state or a discharging state, and the battery's heat exchange state is in a heating state. Fourth state: When the measured temperature value is within the fourth temperature range, the battery is in a charging state or a discharging state, and the battery's heat exchange state is neither heating nor cooling. Fifth state: When the measured temperature value is within the fifth temperature range, the battery is in a charging state or a discharging state, and the battery's heat exchange state is a cooling state.

11. A thermal management method according to claim 10, characterized in that: The first temperature range is less than -20℃, the second temperature range is -20℃ to 5℃, the third temperature range is 5℃ to 15℃, the fourth temperature range is 15℃ to 37℃, and the fifth temperature range is greater than 37℃.

12. A thermal management method according to claim 10 or 11, characterized in that: The second temperature range is further defined by a first termination temperature value. When the measured temperature value is greater than the first termination temperature value, the first state is exited.

13. A thermal management method according to claim 10 or 11, characterized in that: The third temperature range is further defined by a second termination temperature value. When the measured temperature value is greater than the second termination temperature value, the second state is exited.

14. A thermal management method according to claim 10 or 11, characterized in that: The fourth temperature range is further defined by a third termination temperature value. When the measured temperature value is greater than the third termination temperature value, the third state is exited.

15. A thermal management method according to claim 14, characterized in that: The fourth temperature range is further defined by a fourth termination temperature value. When the measured temperature value is less than the fourth termination temperature value, the system exits the fifth state.

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