Battery pack and vehicle

Abstract

The utility model relates to a battery pack and a vehicle, the battery pack comprises a battery module, a heat absorption device and a buffer pad, the battery module comprises a plurality of battery cells, the plurality of battery cells are arranged in a matrix mode, the heat absorption device and the buffer pad are alternately arranged between the adjacent battery cells in the length direction of the battery pack, the heat absorption device can absorb and block heat generated by the battery cells, and the buffer pad can absorb and block the heat generated by the battery cells. And the buffering pad can buffer the deformation of the battery cells, so that the possibility of mutual extrusion of the adjacent battery cells is reduced. The heat absorption device comprises a first state and a second state, when the heat absorption device is in the first state, heat generated by the battery cells can be absorbed, after a certain battery cell is in thermal runaway, the heat absorbed by the heat absorption device is larger than or equal to a preset range, the first state is converted into the second state, and the heat conductivity coefficient of the second state is smaller than that of the first state. And the heat transfer between the adjacent battery cells is reduced, the possibility of thermal runaway after the adjacent battery cells absorb a large amount of heat is reduced, and the safety of the battery pack is improved.

Description

Technical Field

[0001] This application relates to the field of power battery technology, and in particular to a battery pack and a vehicle. Background Technology

[0002] With the rapid development of the new energy market and the increasing popularity and ownership of electric vehicles, full electrification has become the main direction and goal for the transformation, upgrading, and green development of the automotive industry. As the power source of electric vehicles, the battery pack generates heat during charging and discharging. Excessive heat within the battery pack can lead to thermal runaway. Electric vehicles may catch fire or even explode due to thermal runaway of the battery pack. Utility Model Content

[0003] In view of this, this application provides a battery pack and a vehicle to solve the problem of battery packs being prone to thermal runaway.

[0004] In a first aspect, embodiments of this application provide a battery pack, the battery pack comprising:

[0005] A battery module, the battery module comprising multiple battery cells arranged in a matrix;

[0006] A heat-absorbing device and a buffer pad are alternately disposed between adjacent battery cells along the length direction of the battery pack;

[0007] The heat-absorbing device includes a first state and a second state. When the heat-absorbing device is in the first state, it can absorb the heat of the battery cell. When the heat absorbed by the heat-absorbing device is greater than or equal to a preset range, the heat-absorbing device changes from the first state to the second state. The thermal conductivity of the second state is less than that of the first state.

[0008] In one possible embodiment, the heat-absorbing device includes a housing and a composite material located within the housing. The composite material includes a support structure and a heat-absorbing material. The support structure includes a plurality of pores, and the heat-absorbing material fills the pores.

[0009] In one possible embodiment, the cross-sectional area of ​​the heat-absorbing device is less than or equal to the cross-sectional area of ​​the battery cell.

[0010] In one possible embodiment, the thickness of the heat-absorbing device is 1 mm to 3 mm.

[0011] In one possible embodiment, the thickness of the cushioning pad is 0.5 mm to 2 mm.

[0012] In one possible embodiment, adhesive members are provided on both sides of the heat-absorbing device in the thickness direction, and the heat-absorbing device is bonded to the battery cell through the adhesive members.

[0013] In one possible embodiment, along the length of the battery pack, there are heat absorption devices between the two sets of adjacent cells at both ends of the battery module.

[0014] In one possible embodiment, the battery pack includes a plurality of insulation components, which are located on the sides of the battery module along the length and width directions of the battery pack.

[0015] In one possible embodiment, the insulation element is made of microporous foamed polypropylene.

[0016] Secondly, embodiments of this application also provide a vehicle, the vehicle including a power system, a braking system, a steering system and a driving system, the power system including a battery pack, the battery pack being the battery pack described in any of the above embodiments.

[0017] This application relates to a battery pack and a vehicle. The battery pack includes a battery module, a heat-absorbing device, and a buffer pad. The battery module includes multiple battery cells arranged in a matrix. Along the length of the battery pack, the heat-absorbing device and the buffer pad are alternately disposed between adjacent battery cells. The heat-absorbing device can absorb and block the heat generated by the battery cells, reducing the possibility of thermal runaway. The buffer pad can cushion the deformation of the battery cells, reducing the possibility of adjacent battery cells squeezing each other. The heat-absorbing device has a first state and a second state. When the heat-absorbing device is in the first state, it can absorb the heat generated by the battery cells. After a battery cell experiences thermal runaway, if the heat absorbed by the heat-absorbing device is greater than or equal to a preset range, it will change from the first state to the second state. The thermal conductivity of the second state is lower than that of the first state, reducing heat transfer between adjacent battery cells and reducing the possibility of adjacent battery cells also experiencing thermal runaway after absorbing a large amount of heat, thus improving the safety of the battery pack. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the battery module provided in an embodiment of this application;

[0020] Figure 2 An exploded view of the battery module provided in the embodiments of this application;

[0021] Figure 3 Exploded view of the heat-absorbing device provided in the embodiments of this application;

[0022] Figure 4 This is a schematic diagram of the heat absorption device provided in an embodiment of this application.

[0023] Figure label:

[0024] 1-Battery module;

[0025] 11-Battery cell;

[0026] 12-End plate;

[0027] 2-Heat absorption device;

[0028] 21-Shell;

[0029] 211-First shell;

[0030] 212 - Second shell;

[0031] 22-Composite materials;

[0032] 221-Bearing structure;

[0033] 222 - Heat-absorbing material;

[0034] 3-Cushioning pad;

[0035] 4-Adhesive components;

[0036] 5-Insulation components. Detailed Implementation

[0037] To better understand the technical solution of this application, the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0038] It should be understood that the described embodiments are merely some, not all, of the embodiments in this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0039] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms “a,” “the,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0040] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0041] like Figure 1 and Figure 2 As shown in the figure, this application embodiment provides a battery pack, which includes a battery module 1, and the battery module 1 includes multiple battery cells 11 arranged in a matrix. The battery pack also includes a heat absorption device 2 and a buffer pad 3, which are alternately disposed between adjacent battery cells 11 along the length Y direction of the battery pack.

[0042] During the charging and discharging process of the battery cell 11, heat is generated. The heat-absorbing device 2, which is placed between adjacent battery cells 11, includes a heat-absorbing material 222 that can absorb the heat generated by the battery cell 11. During the charging and discharging process of the battery cell 11, the possibility of thermal runaway within the battery pack is reduced, which is beneficial to improving the safety of the battery pack. The buffer pad 3 can be made of a material with good elasticity, such as foam. After multiple charging and discharging cycles, the battery cell 11 may expand during the charging and discharging process. The buffer pad 3 has good elasticity and can buffer the expansion of the battery cell 11, reducing the possibility that one battery cell 11 in the battery module 1 may compress adjacent battery cells 11 after expansion, which is beneficial to reducing the possibility of mutual interference between adjacent battery cells 11. The buffer pad 3 also needs to have good insulation to reduce the possibility of short circuits caused by electrical connection between adjacent battery cells 11 through the buffer pad 3, which is beneficial to improving the safety of the battery pack. The heat-absorbing device 2 and the buffer pad 3 are arranged alternately to absorb the heat generated by the battery cell 11, reducing the possibility of thermal runaway of the battery cell 11, and to buffer the deformation of the battery cell 11, reducing the possibility of mutual compression between adjacent battery cells 11.

[0043] like Figure 3 As shown, in one possible embodiment, the heat-absorbing device 2 includes a housing 21 and a composite material 22, with the composite material 22 located inside the housing 21. The composite material 22 includes a supporting structure 221 and a heat-absorbing material 222. The supporting structure 221 includes multiple pores, and the heat-absorbing material 222 is in a gel state at room temperature, filling the pores of the supporting structure 221.

[0044] The composite material 22 is located inside the housing 21. Under normal temperature conditions, it can fix the heat-absorbing material 222 between adjacent cells 11, reducing the possibility of leakage of the gel-state heat-absorbing material 222 and improving the heat absorption effect of the heat-absorbing device 2. The supporting structure 221 enables the heat-absorbing material 222 to be evenly distributed within the housing 21, which is beneficial to improving the uniformity of the heat dissipation effect of the heat-absorbing device 2.

[0045] Along the length Y of the battery pack, the housing 21 of the heat absorption device 2 includes a first housing 211 and a second housing 212. Along the width X and height Z of the battery pack, the first housing 211 is provided with flanges on all four sides. The thickness of the flanges can be 1 mm. A receiving space is formed on the first housing 211. The composite material 22 is placed in the receiving space. Then, the second housing 212 is pressed onto the first housing 211 to seal the receiving space.

[0046] In one possible embodiment, the heat-absorbing material 222 can be paraffin wax and polyvinyl alcohol. A gel is formed by cross-linking paraffin wax, polyvinyl alcohol, boric acid, and heat stabilizers through an emulsion mixture of various chemical additives. The paraffin wax and other substances are dispersed in the gel material and act within the voids of the special fiber aerogel. At room temperature, the heat-absorbing device 2 is in its first state, and the heat-absorbing material 222 is in a gel state, allowing it to contact the inner wall of the casing 21. This results in a higher thermal conductivity for the heat-absorbing device 2, facilitating heat transfer between adjacent battery cells 11. During charging and discharging, the temperature of the battery cells 11 in the battery module 1 rises, generating heat. The heat-absorbing device 2 can absorb and store the heat generated by the battery cells 11, reducing the possibility of thermal runaway due to excessively high temperatures in the battery cells 11. When a cell 11 in battery module 1 experiences thermal runaway, the cell 11 will generate a large amount of heat. After the heat absorption device 2 absorbs the heat generated by the cell 11 to a value greater than or equal to a preset range, it will change from the first state to the second state. The heat absorption material 222 will undergo a chemical reaction, causing the heat absorption material 222 to decompose into solid and gaseous states. The gaseous heat absorption material 222 is located between the solid heat absorption material 222 and the inner wall of the shell 21, which will reduce the thermal conductivity of the heat absorption device 2.

[0047] When the heat-absorbing device 2 is in its first state, its thermal conductivity is relatively high, facilitating heat transfer between the two battery cells 11 on either side of the device. This improves the temperature uniformity of the multiple battery cells 11 and helps extend the battery pack's lifespan. If a battery cell 11 experiences thermal runaway, the heat-absorbing device 2 switches to its second state, where its thermal conductivity is lower. This reduces heat transfer between adjacent battery cells 11, lowering the possibility of neighboring cells 11 absorbing a large amount of heat and also experiencing thermal runaway, thus improving the battery pack's safety.

[0048] In one possible embodiment, the cross-sectional area of ​​the heat-absorbing device 2 is less than or equal to the cross-sectional area of ​​the battery cell 11.

[0049] The heat-absorbing device 2 is located between adjacent battery cells 11 and in contact with the surface of the battery cells 11 to absorb the heat generated by the battery cells 11. The cross-sectional area of ​​the heat-absorbing device 2 is less than or equal to the cross-sectional area of ​​the battery cell 11, reducing the possibility of the heat-absorbing device 2 protruding and thus reducing the possibility of interference between the heat-absorbing device 2 and other devices in the battery pack. Taking a square battery cell 11 as an example, the heat-absorbing device 2 is located on the side with the larger cross-section of the battery cell 11, which can increase the contact area between the heat-absorbing device 2 and the battery cell 11, making it easier for the heat-absorbing device 2 to absorb the heat generated by the battery cell 11 and improving the heat absorption effect of the heat-absorbing device 2. Preferably, the cross-sectional area of ​​the heat-absorbing device 2 is equal to the cross-sectional area of ​​the battery cell 11, and both can have a length of 148 mm and a width of 112 mm to improve the heat absorption effect of the heat-absorbing device 2.

[0050] In one possible embodiment, the thickness of the heat-absorbing device 2 is 1 mm to 3 mm along the length Y direction of the battery pack.

[0051] The heat-absorbing device 2 can absorb the heat generated by the battery cell 11. As the thickness of the heat-absorbing device 2 increases, the amount of heat-absorbing material 222 within it can be increased, thereby improving its heat absorption capacity. The thickness of the heat-absorbing device 2 is greater than or equal to 1 mm, enabling it to absorb the heat generated during thermal runaway of the battery cell 11, thus maintaining the battery pack at a suitable operating temperature. The heat-absorbing device 2 is located between adjacent battery cells 11, allowing heat generated by two adjacent cells to be conducted through it. The thickness of the heat-absorbing device 2 is less than or equal to 3 mm, which improves its thermal conductivity, thereby enhancing the temperature uniformity of adjacent cells 11 and extending the battery pack's lifespan. Furthermore, along the length Y of the battery pack, the location of the heat-absorbing device 2 between adjacent cells 11 and its thickness of less than or equal to 3 mm also reduce the length Y dimension of the battery pack. Therefore, the thickness of the heat-absorbing device 2 can be 1 mm, 2 mm, 3 mm, etc., preferably 1 mm.

[0052] like Figure 4 As shown, in one possible embodiment, adhesive members 4 are provided on both sides of the heat absorption device 2 in the thickness direction Y, so that the heat absorption device 2 is bonded to the battery cell 11.

[0053] The heat absorption device 2 is bonded to the battery cell 11 via the adhesive component 4, which restricts the position of the heat absorption device 2 and reduces the possibility of displacement. At the same time, the heat absorption device 2 can also restrict the position of two adjacent battery cells 11, which helps to improve the reliability of the battery module 1.

[0054] like Figure 2As shown, in one possible embodiment, along the length Y of the battery pack, the battery module 1 includes multiple battery cells 11, with heat-absorbing devices 2 and buffer pads 3 alternately disposed between adjacent battery cells 11. In the battery module 1, the heat-absorbing devices 2 are located between the two sets of adjacent battery cells 11 at both ends, and the buffer pads 3 are located on both sides.

[0055] The heat-absorbing device 2 and the buffer pad 3 are alternately arranged so that one side of the battery cell 11 is in contact with the heat-absorbing device 2 and the other side is in contact with the buffer pad 3, so that the heat generated by the battery cell 11 during charging and discharging can be absorbed by the heat-absorbing device 2 and can be buffered by the buffer pad 3 when expansion occurs.

[0056] The battery module 1 also includes end plates 12 to restrict the position of the cells 11. Both sides of the two sets of cells 11 located at both ends of the battery module 1 are equipped with buffer pads 3, providing a buffer between the cells 11 and the end plates 12. When the cells 11 at the ends expand, this reduces the stress between the cells 11 and the end plates 12, lowering the possibility of damage to the cells 11. Between the two sets of adjacent cells 11 located at both ends of the battery module 1 are heat-absorbing devices 2, allowing the cells 11 at both ends to contact the heat-absorbing devices 2, reducing the possibility of thermal runaway in the cells 11 at both ends, and improving the safety of the battery pack.

[0057] In one possible embodiment, the cross-sectional area of ​​the buffer pad 3 is less than or equal to the cross-sectional area of ​​the battery cell 11. This reduces the possibility of interference and damage between adjacent battery cells 11 when the battery cell 11 expands, and also reduces the possibility of the buffer pad 3 protruding from the battery cell 11 and interfering with other structures within the battery pack. Preferably, the cross-sectional area of ​​the buffer pad 3 is equal to the cross-sectional area of ​​the battery cell 11, and both can have a length of 148 mm and a width of 112 mm to improve the buffering effect of the buffer pad 3.

[0058] In one possible embodiment, the thickness of the buffer pad 3 is 0.5 mm to 2 mm along the length Y direction of the battery pack.

[0059] The buffer pad 3 has good elasticity. Increasing the thickness of the buffer pad 3 improves its elastic deformation. A thickness greater than or equal to 0.5 mm enhances its buffering effect on the battery cell 11. A thickness less than or equal to 2 mm improves its thermal conductivity, allowing heat from adjacent battery cells 11 to be conducted through the buffer pad 3, thus improving temperature uniformity and reducing the length (Y) dimension of the battery pack. Therefore, the thickness of the buffer pad 3 can be 0.5 mm, 1 mm, 1.5 mm, 2 mm, etc., preferably 0.6 mm, to provide better buffering for the battery cell 11 and improve temperature uniformity among multiple battery cells 11.

[0060] like Figure 2As shown, in one possible embodiment, the battery pack includes a plurality of insulation components 5, which are arranged around the battery module 1. Insulation components 5 are provided on the sides of the battery module 1 along the length direction Y and width direction X of the battery pack.

[0061] Along the length Y of the battery pack, the battery module 1 has end plates 12 on both sides to restrict the position of multiple battery cells 11. The end plates 12 are made of metal and have a high thermal conductivity. When the ambient temperature is low, the heat generated by the battery cells 11 near the end plates 12 is easily dissipated through the end plates 12, resulting in a lower temperature for the battery cells 11 near the end plates 12. A heat insulation component 5 is provided between the end plates 12 and the battery cells 11 to reduce the possibility of heat dissipation from the battery cells 11, which is beneficial for improving the heat preservation of the battery module 1 and the temperature uniformity of the battery cells 11 located in the middle and edge positions. Along the width X of the battery pack, the battery cells 11 located on both sides of the battery module 1 are in direct contact with the air. When the ambient temperature is low, the heat of the battery cells 11 at the edges dissipates faster, resulting in a lower temperature for the battery cells 11 at the edges. Heat insulation components 5 are provided on both sides of the battery module 1 to reduce the temperature difference between the lower temperature of the battery cells 11 at the edges and the battery cells 11 in the middle, which is beneficial for improving the service life of the battery pack.

[0062] In one possible embodiment, the insulation element 5 is made of microporous foamed polypropylene.

[0063] The microporous foamed polypropylene has micron-scale pores inside, which can reduce the convection of gas inside the insulation component 5, thereby quietly reducing the heat transfer caused by air convection, reducing the thermal conductivity of the insulation component 5, reducing the possibility of heat leakage from the battery module 1 when the ambient temperature is low, and also improving the temperature consistency of the cells 11 in different locations within the battery module 1.

[0064] This application also provides a vehicle, which includes a power system, a braking system, a steering system, a driving system, etc., wherein the power system includes the aforementioned battery pack, and the battery pack can provide power to the vehicle when discharged. The technical effects of the battery pack are the same as described above, and will not be repeated here.

[0065] This application relates to a battery pack and a vehicle. The battery pack includes a battery module 1, a heat-absorbing device 2, and a buffer pad 3. The battery module 1 includes multiple battery cells 11 arranged in a matrix along the length Y of the battery pack. The heat-absorbing device 2 and the buffer pad 3 are alternately disposed between adjacent battery cells 11. The heat-absorbing device 2 can absorb and block the heat generated by the battery cells 11, reducing the possibility of thermal runaway of the battery cells 11. The buffer pad 3 can buffer the deformation of the battery cells 11, reducing the possibility of adjacent battery cells 11 squeezing each other. The heat-absorbing device 2 has a first state and a second state. When the heat-absorbing device 2 is in the first state, it can absorb the heat generated by the battery cells 11. After a battery cell 11 experiences thermal runaway, if the heat absorbed by the heat-absorbing device 2 is greater than or equal to a preset range, it will change from the first state to the second state. The thermal conductivity of the second state is less than that of the first state, reducing heat transfer between adjacent battery cells 11 and reducing the possibility of adjacent battery cells 11 also experiencing thermal runaway after absorbing a large amount of heat, which is beneficial to improving the safety of the battery pack.

Claims

1. A battery pack, characterized in that, The battery pack includes: A battery module (1) includes multiple battery cells (11) arranged in a matrix. The heat-absorbing device (2) and the buffer pad (3) are alternately arranged between adjacent cells (11) along the length direction of the battery pack. The heat-absorbing device (2) includes a first state and a second state. When the heat-absorbing device (2) is in the first state, it can absorb the heat of the battery cell (11). When the heat absorbed by the heat-absorbing device (2) is greater than or equal to a preset range, the heat-absorbing device (2) changes from the first state to the second state. The thermal conductivity of the second state is less than that of the first state.

2. The battery pack according to claim 1, characterized in that, The heat absorption device (2) includes a shell (21) and a composite material (22). The composite material (22) is located inside the shell (21). The composite material (22) includes a supporting structure (221) and a heat-absorbing material (222). The supporting structure (221) includes multiple pores, and the heat-absorbing material (222) fills the pores.

3. The battery pack according to claim 1, characterized in that, The cross-sectional area of ​​the heat-absorbing device (2) is less than or equal to the cross-sectional area of ​​the battery cell (11).

4. The battery pack according to claim 1, characterized in that, The thickness of the heat absorption device (2) is 1 mm to 3 mm.

5. The battery pack according to claim 1, characterized in that, The thickness of the buffer pad (3) is 0.5 mm to 2 mm.

6. The battery pack according to claim 1, characterized in that, The heat absorption device (2) has adhesives (4) on both sides in the thickness direction, and the heat absorption device (2) and the battery cell (11) are bonded together by the adhesives (4).

7. The battery pack according to claim 1, characterized in that, Along the length of the battery pack, there are heat absorption devices (2) between the two sets of adjacent cells (11) at both ends of the battery module (1).

8. The battery pack according to claim 1, characterized in that, The battery pack includes multiple insulation components (5), which are located on the sides of the battery module (1) along the length and width directions of the battery pack.

9. The battery pack according to claim 8, characterized in that, The insulation component (5) is made of microporous foamed polypropylene.

10. A vehicle, characterized in that, The vehicle includes a power system, a braking system, a steering system, and a driving system, wherein the power system includes a battery pack, and the battery pack is the battery pack according to any one of claims 1 to 9.

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