Battery pack and vehicle including the battery pack

Abstract

The present invention relates to the technical field of power batteries, and in particular to a battery pack and a vehicle including the battery pack. The present invention is intended to solve the problem of large heat loss of existing power batteries in low-temperature environments. To this end, the battery pack of the present invention includes: a frame, a mounting position is formed in the frame; a battery module, the battery module is mounted in the mounting position, and the battery module includes a plurality of battery cells; a side beam, the side beam is connected to the outer side wall of the frame, and the side beam is made of a first heat insulating material. The above-mentioned arrangement can reduce the natural convection heat exchange coefficient between the side wall of the frame and the environment, reduce the heat flux, and thus reduce the temperature loss of the battery cell.

Description

Technical Field

[0001] The present invention relates to the technical field of power batteries, and in particular to a battery pack and a vehicle including the battery pack. Background Art

[0002] With the increasing market share of new energy vehicles, especially pure electric vehicles, they are becoming increasingly common in cold northern environments. When a vehicle is stationary in cold conditions for extended periods, the battery, a core component of an electric vehicle, must maintain an ideal internal cell temperature, directly impacting its chemical activity and lifespan.

[0003] Typically, to ensure the overall structural strength of power batteries, the outer shell of power batteries is made of metal. However, in low-temperature environments, the metal material is more likely to exchange heat with the external environment, causing the battery cell temperature to drop too quickly. To address this issue, some manufacturers have equipped power batteries with active heating functions, which actively heat the power battery when the battery temperature drops to a certain threshold. However, this method requires frequent or long-term operation of the heater to keep the battery warm, which is not only inefficient but also consumes a lot of power from the power battery, resulting in a significant loss of range.

[0004] Accordingly, the art requires a new battery pack and a vehicle including the battery pack to solve the above problems. Summary of the Invention

[0005] In order to solve at least one of the above-mentioned problems in the prior art, that is, to solve the problem of large heat loss of existing power batteries in low-temperature environments, the present invention provides a battery pack, which includes: a frame, a mounting position formed in the frame; a battery module, the battery module is installed in the mounting position, and the battery module includes a plurality of battery cells; a side beam, the side beam is connected to the outer side wall of the frame, and the side beam is made of a first thermal insulation material.

[0006] In the preferred technical solution of the above battery pack, the first thermal insulation material is a micro-foam composite material.

[0007] In the preferred technical solution of the above battery pack, the micro-foamed composite material is micro-foamed polypropylene or micro-foamed nylon.

[0008] In the preferred technical solution of the above battery pack, two side beams are provided, and the two side beams are respectively connected to the two side walls of the frame along the length direction of the frame.

[0009] In the preferred technical solution of the above battery pack, the interior of the side beam is filled with energy-absorbing material.

[0010] In the preferred technical solution of the above-mentioned battery pack, a plurality of ribs are formed inside the side beam, and the plurality of ribs divide the interior of the side beam into a plurality of installation cavities opening toward the frame, and the energy-absorbing material is filled in the plurality of installation cavities.

[0011] In the preferred technical solution of the above battery pack, the energy-absorbing material is foamed polypropylene or ethylene-vinyl acetate copolymer.

[0012] In the preferred technical solution of the above-mentioned battery pack, the outer side wall of the frame is provided with a hanging ear for connecting to the vehicle, and the interior of the side beam is formed with a covering cavity opening toward the frame. In the connected state, the hanging ear is accommodated in the covering cavity.

[0013] In the preferred technical solution of the above-mentioned battery pack, a plurality of reinforcing ribs are formed on the outer side wall of the frame, a plurality of filling spaces are formed between the plurality of reinforcing ribs, and each of the filling spaces is filled with a second thermal insulation material.

[0014] In the preferred technical solution of the above battery pack, the second thermal insulation material is a foamed thermal insulation material.

[0015] In the preferred technical solution of the above battery pack, the foam insulation material is silicone foam, polyurethane sponge or polyvinyl chloride foam plastic.

[0016] In the preferred technical solution of the above battery pack, the frame is a hollow structure forming a cavity, and the cavity is filled with a phase change material.

[0017] In the preferred technical solution of the above battery pack, the phase change material is an inorganic phase change material, an organic phase change material or a composite phase change material.

[0018] In the preferred technical solution of the above-mentioned battery pack, the battery pack further includes an active thermal compensation component, which is arranged on the heat dissipation path of the battery module, and the active thermal compensation component is configured to heat the battery cell.

[0019] In the preferred technical solution of the above battery pack, the active thermal compensation component is connected to the battery management system.

[0020] In the preferred technical solution of the above-mentioned battery pack, the frame includes an outer frame and an inner frame, the outer frame and the inner frame are arranged to form a plurality of the mounting positions, and the active thermal compensation component is arranged on the inner side wall of the outer frame.

[0021] In the preferred technical solution of the above-mentioned battery pack, the active thermal compensation component is an electric heater, a graphene heat radiation sheet or a semiconductor cooler.

[0022] In a preferred technical solution of the above battery pack, the battery pack further includes a temperature balancing component, which is disposed in the frame and configured to balance the temperatures between different battery cells.

[0023] In the preferred technical solution of the above battery pack, the temperature equalizing component is attached to the outer side wall of the battery module close to the periphery of the frame.

[0024] In the preferred technical solution of the above-mentioned battery pack, the temperature equalizing component is a heat pipe group, a heat-conducting aluminum plate group or a heat-conducting silicone sheet group.

[0025] The present application also provides a vehicle, which includes a battery pack according to any one of the above-mentioned preferred technical solutions.

[0026] It will be understood by those skilled in the art that, in the preferred technical solution of the present invention, the battery pack includes: a frame, a mounting position is formed in the frame; a battery module, the battery module is installed in the mounting position, and the battery module includes a plurality of battery cells; a side beam, the side beam is connected to the outer side wall of the frame, and the side beam is made of a first thermal insulation material.

[0027] The above-mentioned setting method can reduce the natural convection heat transfer coefficient between the side wall of the frame and the environment, reduce the heat flux, and thus reduce the temperature loss of the battery cell. Specifically, by connecting the side beams to the outer wall of the frame, and the side beams are made of the first thermal insulation material, the battery pack can achieve heat exchange between the side beams and the frame at a lower heat conduction rate during normal use. That is, under low temperature conditions, the speed at which heat is conducted to the side beams through the connection between the frame and the side beams can be reduced, and the speed of heat conduction and heat radiation from the side beams to the outside air can be reduced, thereby reducing heat loss, thereby maintaining the temperature of the battery cell at a more reasonable value for a long time, and ensuring the performance of the battery pack under low temperature conditions.

[0028] Furthermore, by filling the side beams with energy-absorbing materials, when the vehicle collides, part of the energy generated by the collision can be absorbed by the energy-absorbing materials in the side beams, reducing the impact of the collision on the battery pack and improving the safety of the battery pack.

[0029] Furthermore, by forming a covering cavity inside the side beam and using the covering cavity to cover the hanging ears provided on the outer side wall of the frame, heat loss through the hanging ears can be further reduced.

[0030] Furthermore, by forming multiple reinforcing ribs on the outer wall of the frame, creating spaces between the ribs, and then filling these spaces with a second thermal insulation material, the ribs not only enhance the structural strength, but the spaces between the ribs also provide sufficient insulation against heat loss through the second thermal insulation material. As a result, when the battery pack is stationary in a cold environment, the heat flux around the frame is significantly reduced, significantly improving the battery cell temperature compared to conventional battery pack designs.

[0031] Furthermore, by filling the hollow structure of the frame with phase change material, when the temperature of the battery cell drops to a certain level, the phase change material works to release latent heat, slowing down the rate of heat loss from the battery and extending the insulation time.

[0032] Furthermore, by placing active thermal compensation components along the battery module's heat dissipation path, when the battery cell temperature is low, only a small amount of heat source is applied along this specific heat transfer path to compensate for the heat lost to the air, thereby extending the battery cell's heat retention time. Compared to existing battery pack heating functions, this configuration reduces battery power consumption and minimizes the impact of active thermal compensation on driving range.

[0033] Furthermore, by setting up a temperature equalizing component within the frame, a heat transfer channel can be constructed between the battery cells with higher temperatures and the battery cells with lower temperatures inside the battery pack, thereby reducing the temperature difference between the battery cells in the battery pack, improving the temperature uniformity of the battery pack, and alleviating the short-board effect.

[0034] Another aspect of the present invention provides a vehicle. By installing the above-mentioned battery pack on the vehicle, when the vehicle is stationary in a cold environment, the battery pack can maintain heat for a sufficiently long time while consuming little or no power, thereby ensuring that the performance of the battery pack is not affected after being placed outdoors for a long time.

[0035] Solution 1: A battery pack, characterized in that the battery pack comprises:

[0036] a frame, wherein a mounting position is formed in the frame;

[0037] a battery module, the battery module being installed in the installation position and comprising a plurality of battery cells;

[0038] The side beam is connected to the outer side wall of the frame and is made of a first heat insulating material.

[0039] Option 2: The battery pack according to Option 1 is characterized in that the first thermal insulation material is a micro-foam composite material.

[0040] Option 3: The battery pack according to Option 2 is characterized in that the micro-foamed composite material is micro-foamed polypropylene or micro-foamed nylon.

[0041] Option 4: The battery pack according to Option 1 is characterized in that there are two side beams, and the two side beams are respectively connected to the two side walls of the frame along the length direction of the frame.

[0042] Option 5: The battery pack according to Option 1 is characterized in that the interior of the side beam is filled with energy-absorbing material.

[0043] Option 6: The battery pack according to Option 5 is characterized in that a plurality of ribs are formed inside the side beam, and the plurality of ribs divide the interior of the side beam into a plurality of installation cavities opening toward the frame, and the energy-absorbing material is filled in the plurality of installation cavities.

[0044] Option 7: The battery pack according to Option 5 is characterized in that the energy-absorbing material is foamed polypropylene or ethylene-vinyl acetate copolymer.

[0045] Option 8. The battery pack according to Option 1 is characterized in that the outer wall of the frame is provided with a hanging ear for connecting to the vehicle, and the interior of the side beam is formed with a covering cavity opening toward the frame, and when in a connected state, the hanging ear is accommodated in the covering cavity.

[0046] Option 9: The battery pack according to Option 1 is characterized in that a plurality of reinforcing ribs are formed on the outer side wall of the frame, a plurality of filling spaces are formed between the plurality of reinforcing ribs, and each of the filling spaces is filled with a second thermal insulation material.

[0047] Option 10: The battery pack according to Option 9 is characterized in that the second thermal insulation material is a foamed thermal insulation material.

[0048] Option 11. The battery pack according to Option 10 is characterized in that the foam insulation material is silicone foam, polyurethane sponge or polyvinyl chloride foam plastic.

[0049] Option 12: The battery pack according to Option 1 is characterized in that the frame is a hollow structure forming a cavity, and the cavity is filled with phase change material.

[0050] Option 13: The battery pack according to Option 12 is characterized in that the phase change material is an inorganic phase change material, an organic phase change material or a composite phase change material.

[0051] Option 14: The battery pack according to Option 1 is characterized in that the battery pack also includes an active thermal compensation component, the active thermal compensation component is arranged on the heat dissipation path of the battery module, and the active thermal compensation component is configured to heat the battery cell.

[0052] Option 15: The battery pack according to Option 14 is characterized in that the active thermal compensation component is connected to the battery management system.

[0053] Option 16. The battery pack according to Option 14 is characterized in that the frame includes an outer frame and an inner frame, the outer frame and the inner frame are arranged to form a plurality of mounting positions, and the active thermal compensation component is arranged on the inner side wall of the outer frame.

[0054] Option 17. The battery pack according to Option 14 is characterized in that the active thermal compensation component is an electric heater, a graphene heat radiation sheet or a semiconductor cooler.

[0055] Option 18. The battery pack according to Option 1 is characterized in that the battery pack also includes a temperature equalizing component, the temperature equalizing component is arranged in the frame, and the temperature equalizing component is configured to balance the temperatures between different battery cells.

[0056] Option 19: The battery pack according to Option 18 is characterized in that the temperature equalizing component is attached to the outer wall of the battery module near the periphery of the frame.

[0057] Option 20: The battery pack according to Option 18 is characterized in that the temperature equalizing component is a heat pipe group, a thermally conductive aluminum plate group or a thermally conductive silicone sheet group.

[0058] Option 21. A vehicle, characterized in that the vehicle includes the battery pack described in any one of Options 1 to 20. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] The battery pack of the present invention and the vehicle including the battery pack are described below with reference to the accompanying drawings and in conjunction with a pure electric vehicle.

[0060] Figure 1 An exploded view of the battery pack of the present invention;

[0061] Figure 2 A partial cross-sectional view of the battery pack of the present invention;

[0062] Figure 3 A structural diagram of a side beam of a battery pack of the present invention;

[0063] Figure 4 is a cross-sectional view of a side beam of a battery pack of the present invention;

[0064] Figure 5 is a cross-sectional view of a first embodiment of the outer frame of the present invention;

[0065] Figure 6 This is a diagram showing the installation position of the temperature balancing component of the present invention in the battery module;

[0066] Figure 7 It is a cross-sectional view of a second embodiment of the outer frame of the present invention.

[0067] Reference Signs List

[0068] 1. Frame; 11. Outer frame; 12. Inner frame; 13. Mounting position; 14. Mounting ear; 15. Reinforcement rib; 16. Filling space; 17. Cavity; 2. Battery module; 21. Battery cell; 3. Side beam; 31. Rib plate; 32. Mounting cavity; 33. Encapsulation cavity; 34. Through hole; 4. Second thermal insulation material; 5. Energy-absorbing material; 6. Phase change material; 7. Thermal compensation component; 8. Temperature equalization component. DETAILED DESCRIPTION

[0069] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention. For example, although this embodiment is introduced in conjunction with a pure electric vehicle, this is not intended to limit the scope of protection of the present invention. Without departing from the principles of the present invention, those skilled in the art can apply the battery pack of the present invention to other application scenarios. For example, the battery pack of the present invention can also be applied to hybrid vehicles, electric bicycles, electric motorcycles, etc.

[0070] It should be noted that in the description of the present invention, terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. These are merely for ease of description and are not intended to indicate or imply that the device or element described must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0071] Furthermore, it should be noted that, in the description of the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0072] Example 1

[0073] First refer to Figure 1 , the first embodiment of the battery pack of the present invention is described. Figure 1 This is an exploded view of the battery pack of the present invention.

[0074] like Figure 1 As shown, in order to solve the problem of large heat loss of existing power batteries in low temperature environments, the present invention provides a battery pack, which includes a frame 1, a plurality of battery modules 2 and two side beams 3. A plurality of mounting positions 13 are formed in the frame 1, and each battery module 2 is mounted in a mounting position 13. Each battery module 2 includes a plurality of battery cells 21 (see Figure 6 ), multiple battery cells 21 are connected in series and / or in parallel. The two side beams 3 are respectively connected to the two outer side walls of the frame 1, and the side beams 3 are made of a first heat insulating material.

[0075] The above-mentioned arrangement can reduce the natural convection heat transfer coefficient between the side wall of the frame 1 and the environment, and reduce the heat flux, thereby reducing the temperature loss of the battery cell 21. Specifically, by connecting the side beam 3 to the outer wall of the frame 1, and the side beam 3 is made of the first thermal insulation material, the battery pack can achieve heat exchange between the side beam 3 and the frame 1 at a lower heat conduction rate during normal use. That is, under low temperature conditions, the speed at which heat is conducted to the side beam 3 through the connection between the frame 1 and the side beam 3 can be reduced, and the speed of heat conduction and heat radiation from the side beam 3 to the outside air can be reduced, thereby reducing heat loss, thereby maintaining the temperature of the battery cell 21 at a relatively reasonable value for a long time, and ensuring the performance of the battery pack under low temperature conditions.

[0076] Those skilled in the art will understand that, although the above embodiment only describes that the battery pack includes a frame 1, a battery module 2 and a side beam 3, it is obvious that these are not all the components of the battery pack. Under normal circumstances, the battery pack may also include one or more of a shell, an upper cover, a lower cover, a cooling plate, a battery management system (BMS), etc. In order to unnecessarily obscure the embodiments of the present disclosure, these structures are not shown in the accompanying drawings.

[0077] Further reference below Figures 1 to 6 , the battery pack of this embodiment is described in detail. Figure 2 A partial cross-sectional view of the battery pack of the present invention; Figure 3 A structural diagram of a side beam of a battery pack of the present invention; Figure 4 is a cross-sectional view of a side beam of a battery pack of the present invention; Figure 5 is a cross-sectional view of a first embodiment of the outer frame of the present invention; Figure 6 This is a diagram showing the installation position of the temperature balancing component of the present invention in the battery module.

[0078] like Figure 1 As shown, in a possible embodiment, the frame 1 is made of a metal material, such as aluminum alloy or stainless steel casting, and includes an outer frame 11 and an inner frame 12. The outer frame 11 is in a "convex" shape as a whole, and six rectangular mounting positions 13 are formed between the outer frame 11 and the inner frame 12. Correspondingly, six battery modules 2 are provided, and the outer peripheral shape of the battery module 2 is adapted to the mounting position 13, and each battery module 2 is fixedly embedded in a mounting position 13. A plurality of hanging ears 14 are integrally formed on the outer side wall of the outer frame 11, and the hanging ears 14 are provided with connection holes. After the battery pack is assembled, the hanging ears 14 can be fixedly connected to the chassis of the pure electric vehicle (hereinafter referred to as electric vehicle or vehicle) by screws, pins and other connectors, thereby fixing the battery pack to the pure electric vehicle to provide energy for the vehicle.

[0079] Continue to refer to Figure 1 In this embodiment, two side beams 3 are provided, and the two side beams 3 are arranged along the length direction of the frame 1 (ie Figure 1 A direction in the figure) are respectively connected to the two side walls of the outer frame 11. Specifically, see Figures 2 to 4 The side beam 3 is in the shape of a long strip as a whole, and is connected to the outer frame 11 by riveting. The side beam 3 is integrally formed of a first heat-insulating material, and the first heat-insulating material is preferably a micro-foamed composite material, such as a micro-foamed polypropylene material. After molding, the side of the side beam 3 facing the outer frame 11 is an open side, and a plurality of ribs 31 are formed inside the opening. The plurality of ribs 31 divide the inside of the side beam 3 into a plurality of installation cavities 32, and each installation cavity 32 is filled with an energy-absorbing material 5, and the energy-absorbing material 5 is preferably expanded polypropylene (EPP). A covering cavity 33 is also formed inside the opening, and the lug 14 is accommodated in the covering cavity 33 in the riveted state. A through hole 34 is provided in the side beam 3 at the position corresponding to the connection hole on the lug 14, so that the connecting part passes through the through hole 34 to fix the lug 14 to the vehicle chassis.

[0080] See also Figure 1 、 Figure 2 and Figure 5, a plurality of horizontal and vertical reinforcing ribs 15 are formed on the outer wall of the outer frame 11, and a plurality of filling spaces 16 are formed between the plurality of reinforcing ribs 15, and each filling space 16 is filled with a second thermal insulation material 4. The second thermal insulation material 4 is preferably a foamed thermal insulation material, such as silicone foam, polyurethane sponge (also known as PU foam) or polyvinyl chloride foam plastic (also known as foamed PVC). The depth and area of ​​the filling space 16 are calculated so that the filled thermal insulation material can exert sufficient heat insulation ability. Since the frame 1 itself has the requirements of bearing mechanical properties and at the same time has the ability to insulate and heat, the larger the filling space 16, the more second thermal insulation material 4 that can be filled, the better the thermal insulation performance, but the worse the structural performance. Therefore, the method for calculating the size of the filling space 16 should be to maximize the filling space 16 on the basis of ensuring structural strength. For example, the three parameters of the bottom area of ​​the filling space 16, the thickness of the reinforcing rib 15, and the base material thickness of the outer frame 11 are taken and simulated in sequence through the orthogonal analysis method. On the basis of qualified mechanical structure performance simulation, thermal insulation and heat dissipation simulation is carried out based on this. The parameter ratio with the best thermal insulation performance is the best solution.

[0081] Continue to see Figure 1 and Figure 2 , the battery pack also includes an active thermal compensation component 7, which is arranged on the heat dissipation path of the battery module 2, and the active thermal compensation component 7 is configured to heat the battery cell 21. Specifically, the active thermal compensation component 7 can be an electric heater (such as a resistive heater, an electromagnetic heater, a short-wave heater, etc.), or a graphene thermal radiation sheet, or an electrical component made using the Peltier effect, such as a semiconductor refrigerator, etc. Among them, the setting position of the active thermal compensation component 7 is determined based on the quantitative analysis of the heat transfer path. For example, based on the thermal simulation heat dissipation model, the heat transfer interface of each component (such as the environment and the shell, the cooling plate and the frame 1, the upper cover and the shell, the battery cell 21 and the glue, etc.) is extracted to build a thermal simulation model and calculate the heat flux of each component in several hours, and then a data analysis model is established based on the above calculation data to find the heat transfer sensitive path, that is, to determine one or more optimal setting positions of the active thermal compensation component 7. In this embodiment, if Figure 1 As shown, the two inner side walls of the outer frame 11 along the length direction are selected as the best installation positions, and the active thermal compensation component 7 is attached to the inner side walls or embedded in the inner side walls.

[0082] In addition, in a possible application scenario, the active thermal compensation component 7 is connected to the battery management system (BMS) and is controlled by the battery management system. When the temperature of the battery cell 21 drops to a certain temperature threshold, the battery management system determines the optimal working time and power (that is, the energy-saving power and working time) of the active thermal compensation component 7 according to the state of the battery cell 21 and the static time of the battery pack, and then controls the active thermal compensation component 7 to start heating the battery cell 21 according to the above parameters. Among them, the power of active thermal compensation should be determined based on the insulation target (for example, the temperature is greater than or equal to 0°C for 12 hours of insulation). The determination method can be to first roughly determine multiple groups of power and working time parameters based on the thermal capacity of the battery cell 21, the above temperature threshold and the insulation target, and then take the multiple groups of parameters for thermal simulation respectively to finally determine the most energy-saving power and working time under the insulation target.

[0083] See also Figure 1 、 Figure 2 and Figure 6 The battery pack also includes a temperature balancing component 8, which is disposed within the frame 1 and configured to balance the temperatures of different battery cells 21. Specifically, the temperature balancing component 8 preferably utilizes a heat pipe assembly, each heat pipe assembly including multiple heat pipes, and the heat pipe assembly is attached to the outer wall of a portion of the battery module 2 near the outer frame 11. For example Figure 1 As shown in the figure, two heat pipe groups are respectively attached to the outer walls of two battery modules 2 arranged along the length direction of the frame 1, which are close to the outer wall of one long side of the outer frame 11. The length of each heat pipe group is substantially equal to the length of the side wall of the battery module 2.

[0084] The advantages of the above setting are:

[0085] A frame 1 is made of metal material, and a plurality of reinforcing ribs 15 are formed on the outer wall of the frame 1. A filling space 16 is formed between the reinforcing ribs 15. The filling space 16 is filled with a foamed heat-insulating material. Then, a side beam 3 is made of a micro-foamed composite material, and an installation cavity 32 and a covering cavity 33 are formed inside the side beam 3. The installation cavity 32 is filled with an energy-absorbing material 5, and the covering cavity 33 wraps the hanging ear 14. The battery pack of the present application can take into account both structural strength and heat insulation.

[0086] First, the provision of reinforcing ribs 15 not only enhances structural strength, but also allows the spaces 16 formed between the ribs 15 to provide sufficient insulation against heat loss through the presence of the foamed insulation material. Consequently, when the battery pack is stationary in a cold environment, the heat flux around the frame 1 is significantly reduced, significantly improving the temperature of the battery cells 21 compared to conventional battery packs. Second, by using a micro-foam composite material to form the side beams 3, the side beams 3 and the frame 1 can exchange heat at a lower thermal conductivity rate. This reduces the rate of heat conduction from the connection between the frame 1 and the side beams 3 to the side beams 3 at low temperatures, while also reducing the rate of heat conduction and radiation from the side beams 3 to the outside air. This reduces heat loss and maintains the temperature of the battery cells 21 at a relatively reasonable value for a long period of time, ensuring the battery pack's performance in low-temperature conditions. Third, by filling the side beams 3 with expanded polypropylene (EPP), the foamed polypropylene within the side beams 3 absorbs some of the energy generated by a vehicle collision, reducing the impact on the battery pack and improving its safety. Finally, by forming a covering cavity 33 inside the side beam 3 and using the covering cavity 33 to cover the hanging ear 14 set on the outer wall of the frame 1, heat loss through the hanging ear 14 can be reduced, further reducing heat loss of the battery pack.

[0087] Furthermore, the cooling of the battery pack presents a specific temperature distribution trend, such as cold around and hot in the middle, so that the battery cells 21 around become end plates that limit the performance of the entire vehicle. The present application can construct a heat transfer channel between the battery cells 21 with higher temperatures and the battery cells 21 with lower temperatures inside the battery pack by attaching a heat pipe group between the outer wall of the battery module 2 and the outer frame 11, and transfer the heat of the battery cells 21 in the middle part to the battery cells 21 around in time, so that the temperature difference between the battery cells 21 in the battery pack is reduced, the temperature uniformity of the battery pack is improved, and the short-board effect is alleviated.

[0088] Furthermore, by setting an active thermal compensation component 7 on the heat dissipation path of the battery module 2, and setting the active thermal compensation component 7 on the heat transfer sensitive path, when the temperature of the battery cell 21 drops, only a small amount of heat source needs to be applied on the specific heat transfer path to compensate for the heat lost to the air, thereby extending the heat preservation time of the battery cell 21. Compared with the existing battery pack heating function, this setting method can reduce the consumption of battery power and reduce the impact of active thermal compensation on the cruising range. In particular, when the active thermal compensation component 7 is combined with the insulation methods such as filling the outer wall of the frame 1 with foam insulation material, using micro-foam composite materials for the side beam 3, filling the inner part of the measurement with foamed polypropylene, covering the side beam 3 with the hanging ear 14, and attaching heat pipes to the outer wall of the battery module 2, it can greatly reduce the energy consumption of the battery and improve the heating effect.

[0089] Example 2

[0090] See below Figure 7 , briefly introduces the second embodiment of the present invention. Figure 7 It is a cross-sectional view of a second embodiment of the outer frame of the present invention.

[0091] like Figure 7 As shown, under the premise that other settings of Example 1 remain unchanged, the frame 1 is set as follows: the frame 1 is set to a hollow structure to form a cavity 17, and the cavity 17 is filled with a phase change material 6. The frame 1 can be a casting or a profile, and a closed or semi-closed cavity 17 is reserved inside it as a space for filling the phase change material 6. The phase change material 6 can use an inorganic phase change material (such as a crystalline hydrated salt, a molten salt, a metal alloy, etc.), an organic phase change material (such as paraffin, carboxylic acid, ester, polyol, etc.) or a composite phase change material (such as a mixture of an organic phase change material and an inorganic phase change material). Among them, the phase change material 6 is a material with a specific phase change latent heat and phase change temperature point obtained through calculation.

[0092] The characteristics of phase change material 6 include phase change latent heat and temperature phase change point. Among these two parameters, the phase change temperature in particular is customized according to demand. The placement area and placement amount of phase change material 6 can be obtained based on battery thermal simulation. For example, the energy Q required to delay the time from 5°C to 0°C in a specific area of ​​the battery pack for a hour can be calculated with the help of simulation software, and then based on the calculation results, a material with a phase change temperature of about 5°C and a phase change latent heat greater than Q is selected as a qualified solution. In this way, when the temperature of the specific area in the battery pack drops to about 5°C, the phase change material 6 works and releases latent heat.

[0093] By filling the hollow structure of the frame 1 with phase change material 6, when the temperature of the battery cell 21 drops to a certain level, the phase change material 6 works to release latent heat, slowing down the rate of heat loss from the battery and extending the heat preservation time.

[0094] It should be noted that although only two embodiments are provided herein for a battery pack, this is not intended to limit the scope of protection of the present invention. Without departing from the principles of the present invention, those skilled in the art may adjust the above-mentioned configuration so that the present invention can be applied to more specific application scenarios.

[0095] For example, in an alternative embodiment, although the first thermal insulation material described above is described as a micro-foam composite material, this type of thermal insulation material is not fixed. Those skilled in the art may also use other thermal insulation materials as replacements, provided that both strength and thermal insulation are met. For example, the first thermal insulation material may be a material produced using a supercritical extraction process, such as a composite material composed of one or more of aerogel, glass fiber, and polyester. Similarly, in addition to the micro-foam polypropylene described in the above embodiment, the micro-foam composite material may also be a micro-foam nylon material.

[0096] Similarly, the second thermal insulation material 4 may also be adjusted in other embodiments. For example, it may be a material made by supercritical extraction process, such as a composite material composed of one or more combinations of aerogel, glass fiber, and polyester.

[0097] Similarly, the energy absorbing material 5 may also be adjusted in other embodiments. For example, the energy absorbing material 5 may also be ethylene-vinyl acetate copolymer (EVA).

[0098] For example, in another replaceable embodiment, although the above-mentioned heat equalizing assembly is introduced in combination with a heat pipe group, this is not restrictive. In other embodiments, it can also be replaced by a heat-conducting aluminum plate group or a heat-conducting silicone sheet group. This replacement does not deviate from the principle of this application.

[0099] For example, the above-mentioned embodiments 1 and 2 represent only preferred implementations. In other alternative implementations, those skilled in the art may omit some features to create technical solutions that suit other application scenarios. For example, those skilled in the art may omit one or more features of the rib plate 31, the lug 14, the reinforcing rib 15, the energy-absorbing material 5, the second thermal insulation material 4, the active thermal compensation assembly 7, and the temperature-stabilizing assembly 8.

[0100] For example, in an alternative embodiment, although the side beam 3 is connected to the outer frame 11 by riveting, this connection method is not the only one. In other embodiments, the side beam 3 can also be fixedly connected to the outer frame 11 by welding, screwing, etc.

[0101] For example, in another alternative embodiment, although the above technical solution limits the setting position and setting quantity of each feature, this setting method is not unique, and those skilled in the art can adjust its quantity and setting position so that the adjusted technical solution can be applied to more specific application scenarios. For example, in addition to forming six installation positions 13 for battery modules 2, the above outer frame 11 and inner frame 12 can also form any number of installation positions 13, such as one, two, three, or seven, and the number of battery modules 2 only needs to be adjusted accordingly; for example, the side beam 3 can be arranged around all the outer walls of the frame 1, or only on one outer wall; for example, the active thermal compensation component 7 can be attached to one or more of the four inner walls of the outer frame 11, or on the side wall of the inner frame 12; for example, the temperature equalizing component 8 can be arranged around the outer peripheral side of all battery modules 2 facing the outer frame 11, or only on the outer wall of some battery modules 2.

[0102] Of course, the above-mentioned replaceable implementations, as well as the replaceable implementations and the preferred implementations, can be used in a cross-functional manner to combine new implementations to suit more specific application scenarios.

[0103] Example 3

[0104] The present invention further provides a vehicle, which is equipped with the battery pack described in the above embodiment 1 or 2. The vehicle is preferably a pure electric vehicle, and the battery pack is fixedly connected to the chassis of the vehicle.

[0105] By installing the above-mentioned battery pack on a vehicle, when the vehicle is stationary in a cold environment, the battery pack can keep warm for a long enough time without consuming much or even no power, ensuring that the performance of the battery pack is not affected after being placed outdoors for a long time. After repeated tests, observations, analyses and comparisons by the inventors, when an electric vehicle equipped with the battery pack of the present application is stationary in a cold environment, the battery can keep warm for a long enough time (one night) without consuming much power, ensuring that the performance of the vehicle (endurance / acceleration / maximum speed, etc.) is not affected after being placed outdoors all night. Moreover, when an electric vehicle equipped with the battery pack of the present application is stationary in a cold environment for a long time (>1 day), the active thermal compensation component 7 can be activated to slow down the heat loss of the battery, ensuring that the vehicle still has sufficient vehicle performance after being stationary for a longer period of time.

[0106] Those skilled in the art will appreciate that although some embodiments described herein include certain features included in other embodiments but not other features, the combination of features from different embodiments is intended to be within the scope of the present invention and to form different embodiments. For example, in the claims of the present invention, any one of the claimed embodiments may be used in any combination.

[0107] Thus far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art may make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will fall within the scope of protection of the present invention.

Claims

1. A battery pack, characterized in that: The battery pack includes: a frame, wherein a mounting position is formed in the frame; a battery module, the battery module being installed in the installation position and comprising a plurality of battery cells; a side beam connected to an outer side wall of the frame and made of a first heat-insulating material; The outer side wall of the frame is provided with a hanging ear for connecting to the vehicle, and the interior of the side beam is formed with a covering cavity opening toward the frame, and in a connected state, the hanging ear is accommodated in the covering cavity; The hanging ear is provided with a connection hole, and the side beam is provided with a through hole at a position corresponding to the connection hole.

2. The battery pack according to claim 1, wherein: The first thermal insulation material is a micro-foam composite material.

3. The battery pack according to claim 2, wherein: The micro-foamed composite material is micro-foamed polypropylene or micro-foamed nylon.

4. The battery pack according to claim 1, wherein: Two side beams are provided, and the two side beams are respectively connected to the two side walls of the frame along the length direction of the frame.

5. The battery pack according to claim 1, wherein: The interior of the side beam is filled with energy absorbing material.

6. The battery pack according to claim 5, characterized in that: A plurality of ribs are formed inside the side beam, and the plurality of ribs divide the inside of the side beam into a plurality of installation cavities with openings facing the frame, and the energy absorbing material is filled in the plurality of installation cavities.

7. The battery pack according to claim 5, characterized in that: The energy absorbing material is foamed polypropylene or ethylene-vinyl acetate copolymer.

8. The battery pack according to claim 1, wherein: A plurality of reinforcing ribs are formed on the outer side wall of the frame, and a plurality of filling spaces are formed between the plurality of reinforcing ribs. Each of the filling spaces is filled with a second heat insulating material.

9. The battery pack according to claim 8, characterized in that: The second thermal insulation material is a foamed thermal insulation material.

10. The battery pack according to claim 9, characterized in that: The foamed heat-insulating material is silica gel foam, polyurethane sponge or polyvinyl chloride foam plastic.

11. The battery pack according to claim 1, wherein: The frame is a hollow structure and forms a cavity, and the cavity is filled with a phase change material.

12. The battery pack according to claim 11, wherein: The phase change material is an inorganic phase change material, an organic phase change material or a composite phase change material.

13. The battery pack according to claim 1, wherein: The battery pack further includes an active thermal compensation component, which is disposed on a heat dissipation path of the battery module and configured to heat the battery cell.

14. The battery pack according to claim 13, wherein: The active thermal compensation component is connected to the battery management system.

15. The battery pack according to claim 13, wherein: The frame includes an outer frame and an inner frame. The outer frame and the inner frame are arranged to form a plurality of the installation positions. The active thermal compensation component is arranged on the inner side wall of the outer frame.

16. The battery pack according to claim 13, characterized in that: The active thermal compensation component is an electric heater, a graphene heat radiation sheet or a semiconductor cooler.

17. The battery pack according to claim 1, wherein: The battery pack further includes a temperature balancing component, which is disposed in the frame and configured to balance the temperatures between different battery cells.

18. The battery pack according to claim 17, characterized in that: The temperature balancing component is attached to the outer side wall of the battery module close to the periphery of the frame.

19. The battery pack according to claim 17, wherein: The temperature-averaging component is a heat pipe group, a heat-conducting aluminum plate group or a heat-conducting silicone sheet group.

20. A vehicle, characterized in that: The vehicle includes the battery pack according to any one of claims 1 to 19.

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