Battery pack

Abstract

The utility model relates to a battery pack which comprises a shell and a battery module, the shell comprises a bottom shell and an upper cover, and the battery module is mounted in the shell; the bottom shell is provided with a first peripheral wall and a first top wall, and the first top wall divides the bottom shell and the upper cover into independent inner cavities; a first exhaust channel is arranged between the top of the battery module and the first peripheral wall of the bottom shell, and a second exhaust channel is arranged in the upper cover; the first top wall is provided with a first communicating hole, and the first communicating hole communicates with the first exhaust channel and the second exhaust channel. According to the battery pack, the first exhaust channel and the second exhaust channel are arranged in the shell of the battery pack, so that gas generated when the battery pack is subjected to thermal runaway can be exhausted, explosion caused by excessive pressure in the battery pack due to gas accumulation is prevented, and the safety of the battery pack is improved.

Description

Technical Field

[0001] This application relates to the field of battery technology, and more particularly to a battery pack. Background Technology

[0002] Because of their high energy density, lithium-ion batteries can greatly improve the range of electric bicycles. However, lithium-ion batteries have problems such as poor safety and susceptibility to thermal runaway.

[0003] Existing batteries lack thermal runaway protection at the battery pack level, which prevents lithium-ion batteries from being directly used in the electric bicycle industry. Utility Model Content

[0004] This application provides a battery pack that addresses the problem that the lack of thermal runaway protection design at the battery pack level prevents the battery pack from being used in the electric bicycle field.

[0005] This application provides a battery pack comprising: a housing and a battery module; the housing comprising: a bottom shell and a top cover; the battery module being installed within the housing; the bottom shell having a first peripheral wall and a first top wall, the first top wall separating the bottom shell and the top cover into independent cavities; a first exhaust channel being provided between the top of the battery module and the first peripheral wall of the bottom shell; a second exhaust channel being provided within the top cover; and a first connecting hole being provided between the first top walls, the first connecting hole connecting the first exhaust channel and the second exhaust channel.

[0006] In one possible design, the battery module includes battery cells, a plurality of battery cells are stacked along their thickness direction, a first heat insulation member is disposed between adjacent battery cells, the first heat insulation member extends to the top of the battery cell; the battery cell has a body and a shoulder, a second heat insulation member is disposed on the surface of the shoulder near the surface of the first heat insulation member, and a third venting channel is formed between the first heat insulation member and the second heat insulation member by a spacer, the third venting channel being able to communicate with the first venting channel.

[0007] In one possible design, the first venting channel extends along the thickness direction of the cell on the outer side of the top position of the battery module, and the third venting channel is spaced apart along the thickness direction of the cell on the inner side of the top position of the battery module.

[0008] In one possible design, the second thermal insulation member has a first bend that abuts against the surface of the body facing the shoulder.

[0009] In one possible design, the battery module includes a data acquisition module disposed on the side of the battery cell near the first exhaust channel; the data acquisition module has a second connecting hole that connects the first exhaust channel and the third exhaust channel.

[0010] In one possible design, a third heat insulation component is provided on the side of the acquisition module away from the battery cell. The third heat insulation component has an opening that corresponds to the second connecting hole. The third heat insulation component has a second bend at the opening, and the second bend bends toward the direction of the battery cell.

[0011] In one possible design, the first thermal insulation element, the second thermal insulation element, and the third thermal insulation element are respectively selected from aerogel felt, mica tape, or ceramicized silicone rubber.

[0012] In one possible design, the sides and bottom of the battery module are sealed with sealant between them and the first peripheral wall.

[0013] In one possible design, the top cover includes a second peripheral wall, a second top wall, and a partition, the partition being connected to the second peripheral wall and the second top wall, and the space formed by the top cover and the first top wall having a second exhaust passage and an electrical compartment.

[0014] In one possible design, the partition is provided with a connecting groove that connects the second exhaust channel and the electrical compartment; the battery module includes an electrical connector, one end of which is connected to the battery cell and the other end of which extends into the electrical compartment.

[0015] In this application, by providing a first exhaust channel and a second exhaust channel inside the battery pack casing, the gas generated by the battery pack during thermal runaway can be discharged, preventing gas accumulation that could cause excessive pressure inside the battery pack and lead to an explosion, thereby improving the safety of the battery pack.

[0016] It should be understood that the above general description and the following detailed description are merely exemplary and do not limit this application. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the battery pack provided in this application in a specific embodiment;

[0018] Figure 2 for Figure 1 A sectional view;

[0019] Figure 3 for Figure 2 Partial cross-sectional view of the middle shell;

[0020] Figure 4 for Figure 2 A schematic diagram of the structure of the battery cell, the first heat insulation component, and the second heat insulation component of the battery module;

[0021] Figure 5 for Figure 2 A magnified view of a portion of region I;

[0022] Figure 6 for Figure 2 A schematic diagram of the structure of the battery module, excluding the third heat insulation component;

[0023] Figure 7 for Figure 2 A structural diagram of the battery module and electrical connectors, wherein the battery module includes a third heat insulation component;

[0024] Figure 8 for Figure 2 A schematic diagram of the upper and middle covers.

[0025] Figure label:

[0026] 1-Bottom shell;

[0027] 1a - First exhaust passage;

[0028] 1b - First connecting hole;

[0029] 11-First week wall;

[0030] 12-First top wall;

[0031] 13-Bottom wall;

[0032] 2-Top cover;

[0033] 2a - Second exhaust passage;

[0034] 2b - Electrical Warehouse;

[0035] 21-Second week wall;

[0036] 22-Second top wall;

[0037] 23-Partition;

[0038] 231-Connecting slot;

[0039] 3-Battery module;

[0040] 3a - Third exhaust vent;

[0041] 31-cell;

[0042] 311-Ontology;

[0043] 312 - Shoulder;

[0044] 313-Ear;

[0045] 32 - First thermal insulation element;

[0046] 33 - Second thermal insulation component;

[0047] 331 - First bend;

[0048] 34 - Acquisition Module;

[0049] 341 - Second connecting hole;

[0050] 35 - Third thermal insulation component;

[0051] 351 - Opening;

[0052] 352 - Second bend;

[0053] 4-Electrical connections;

[0054] 5-Explosion-proof valve.

[0055] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. Detailed Implementation

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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, and B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0060] It should be noted that the directional terms such as "upper," "lower," "left," and "right" described in the embodiments of this application are used to describe the angles shown in the accompanying drawings and should not be construed as limiting the embodiments of this application. Furthermore, in the context, it should be understood that when it is mentioned that an element is connected "upper" or "lower" to another element, it can be directly connected to the other element "upper" or "lower," or indirectly connected to the other element "upper" or "lower" through an intermediate element.

[0061] This application provides a battery pack, such as... Figure 1 and Figure 2 As shown, the battery pack includes a housing and a battery module 3. The housing includes a bottom shell 1 and a top cover 2. The battery module 3 is installed inside the housing. The bottom shell 1 has a first peripheral wall 11 and a first top wall 12. The first top wall 12 separates the bottom shell 1 and the top cover 2 into independent cavities. A first exhaust channel 1a is provided between the top of the battery module 3 and the first peripheral wall 11 of the bottom shell 1. A second exhaust channel 2a is provided inside the top cover 2. The first top wall 12 has a first connecting hole 1b, which connects the first exhaust channel 1a and the second exhaust channel 2a.

[0062] In this embodiment, such as Figure 1 and Figure 2 As shown, by providing a first exhaust channel 1a and a second exhaust channel 2a inside the battery pack casing, the gas generated by the battery pack during thermal runaway can be discharged, and the excessive pressure inside the battery pack caused by gas accumulation can be prevented from causing an explosion, thereby improving the safety of the battery pack.

[0063] Specifically, the battery pack includes an explosion-proof valve 5, which is located on the upper cover 2. One end of the explosion-proof valve 5 is connected to the second venting channel 2a, and the other end is connected to the outside. When the pressure inside the battery pack is lower than the threshold of the explosion-proof valve 5, the explosion-proof valve 5 closes, thereby sealing the connection between the second venting channel 2a and the outside; when the pressure inside the battery pack is higher than the threshold of the explosion-proof valve 5, the explosion-proof valve 5 opens, thereby connecting the second venting channel 2a to the outside.

[0064] More specifically, such as Figure 2 and Figure 3 As shown, the first peripheral wall 11 includes four side walls connected end to end, which form a cavity structure. The first top wall 12 is located at the first end of the cavity structure. Three of the four side walls are connected to the first top wall 12, and there is a gap between the side walls not connected to the first top wall 12 and the first top wall 12. This gap is the first connecting hole 1b. In addition, the bottom shell 1 also includes a bottom wall 13, which is connected to the second end of the cavity structure. All four side walls are connected to the bottom wall 13, so that the bottom wall 13 closes the second end of the cavity structure.

[0065] Furthermore, such as Figure 2As shown, the battery module 3 includes battery cells 31, with multiple battery cells 31 stacked along their thickness direction. A first heat insulation member 32 is disposed between adjacent battery cells 31, extending to the top of the battery cell 31; as shown Figure 4 and Figure 5 As shown, the battery cell 31 has a body 311 and a shoulder 312 (corresponding to the tab extension position of the battery cell 31). The thickness of the shoulder 312 is thinner than the thickness of the body 311. A second heat insulation member 33 is disposed on the surface of the shoulder 312 near the first heat insulation member 32. The first heat insulation member 32 and the second heat insulation member 33 are spaced apart to form a third exhaust channel 3a, and the third exhaust channel 3a can communicate with the first exhaust channel 1a.

[0066] Along the thickness direction of the cell 31, the projection of the body 311 onto the first heat insulation member 32 does not protrude beyond the edge of the first heat insulation member 32. This means the first heat insulation member 32 can block the transfer of heat between adjacent cells 31, preventing thermal runaway in one group of cells 31 from causing thermal runaway in other cells 31. Because the shoulder 312 is relatively thin, it is difficult for the first heat insulation member 32 to make contact with the body 311. By providing a second heat insulation member 33 on the surface of the shoulder 312, heat transfer at the shoulder 312 can be blocked. Furthermore, a third venting channel 3a is formed between the first heat insulation member 32 and the second heat insulation member 33. This allows the gas generated by the battery pack during thermal runaway to be vented into the first venting channel 1a and then discharged to the outside. Figure 5 The red dashed arrow in the image indicates one direction of gas flow in the exhaust channel.

[0067] Specifically, the first thermal insulation element 32 can be aerogel felt. Aerogel felt is a thermal insulation material made primarily of aerogel, combined with carbon fiber, ceramic glass fiber cotton, or pre-oxidized fiber felt. It has the advantages of low thermal conductivity and light weight. Understandably, the first thermal insulation element 32 can also be made of other materials with low thermal conductivity.

[0068] Optionally, the first thermal insulation element 32 also includes foam, which is bonded to aerogel felt, so that the first thermal insulation element 32 can also play a cushioning role.

[0069] Specifically, the second heat insulation element 33 is mica tape. Mica tape is a fire-resistant and insulating material produced by a mica tape machine. Understandably, the second heat insulation element 33 can also be made of other fire-resistant and insulating materials.

[0070] Furthermore, such as Figure 2As shown, the first exhaust channel 1a extends along the thickness direction of the cell 31 on the outer side of the top position of the battery module 3, and the third exhaust channel 3a is spaced apart along the thickness direction of the cell 31 on the inner side of the top position of the battery module 3. Therefore, multiple third exhaust channels 3a can communicate with the first exhaust channel 1a, and the gas in the multiple third exhaust channels 3a can be discharged into the first exhaust channel 1a.

[0071] Preferred, such as Figure 5 As shown, the second heat insulation member 33 has a first bend 331 that bends towards the first heat insulation member 32. The first bend 331 overlaps the surface of the body 311 facing the shoulder 312, thereby preventing gas from spreading from the first venting channel 1a to the third venting channel 3a adjacent to the cell 31 that has not experienced thermal runaway, thus preventing the temperature of the cell 31 from rising and further improving the safety of the battery pack. In addition, the first bend 331 can also abut against the first heat insulation member 32.

[0072] In one specific implementation, such as Figure 5 and Figure 6 As shown, the battery module 3 includes a data acquisition module 34, which is located on the side of the battery cell 31 near the first exhaust channel 1a. The data acquisition module 34 has a second connecting hole 341, which connects the first exhaust channel 1a and the third exhaust channel 3a, so that the gas generated by the battery pack during thermal runaway will not be blocked by the data acquisition module 34, ensuring the smooth discharge of the gas.

[0073] The acquisition module 34 is used to collect information such as the temperature and voltage of the battery cell 31 to monitor the condition of the battery cell 31. Since the acquisition module 34 is easily damaged at high temperatures, the second heat insulation component 33 can also prevent gas from diffusing into the acquisition module 34, thus protecting the acquisition module 34.

[0074] In addition, the battery cell 31 also includes a tab 313. One end of the tab 313 is connected to the shoulder 312 of the battery cell 31, and the other end passes through the second connecting hole 341 and is bent to connect with the bent tab 313 of the adjacent battery cell 31. That is, the tab 313 of the adjacent battery cell 31 passes through the second connecting hole 341 and overlaps the acquisition module 34, thereby ensuring the accuracy of the information of the battery cell 31 acquired by the acquisition module 34.

[0075] like Figure 5 and Figure 7 As shown, a third heat insulation component 35 is provided on the side of the acquisition module 34 away from the battery cell 31. The third heat insulation component 35 has an opening 351, which is corresponding to the second connecting hole 341. The third heat insulation component 35 has a second bending portion 352 at the opening 351, which bends in the direction of the battery cell 31.

[0076] The third heat insulation component 35 covers the acquisition module 34, thereby preventing the diffusion of gas discharged into the first exhaust channel 1a to the acquisition module 34 and protecting the acquisition module 34. The opening 351 is correspondingly arranged with the second connecting hole 341, so that the installation of the third heat insulation component 35 does not obstruct gas from being discharged from the third exhaust channel 3a into the first exhaust channel 1a. At the same time, the second bend 352 overlaps with the second heat insulation component 33, which can prevent gas in the third exhaust channel 3a from spreading to the tab 313 and the acquisition module 34 through the gap between the second bend 352 and the second heat insulation component 33.

[0077] Preferably, the surface of the third heat insulation component 35 facing the acquisition module 34 is provided with an adhesive layer, which on the one hand enables the third heat insulation component 35 to be stably bonded to the acquisition module 34, and on the other hand enables the second bending portion 352 to be bonded to the second heat insulation component 33, sealing the gap between the second bending portion 352 and the second heat insulation component 33.

[0078] Specifically, the third thermal insulation component 35 can be made of ceramicized silicone rubber. Ceramicized silicone rubber is a new type of composite silicone rubber material that can transform into an inorganic ceramic material at high temperatures. It possesses excellent fire resistance, aging resistance, high-temperature resistance, and electrical properties. Understandably, the third thermal insulation component 35 can also be made of other fire-resistant materials, such as mica paper.

[0079] More specifically, when the third heat insulation component 35 is placed on the acquisition module 34, the second bending part 352 does not bend in the direction of the battery cell 31. At this time, the opening 351 is in the shape of an I-beam. By pressing the second bending part 352, the second bending part 352 overlaps with the second heat insulation component 33.

[0080] In the above embodiments, sealant is applied between the side and bottom of the battery module 3 and the first peripheral wall 11. Since the battery module 3 only contacts three side walls of the first peripheral wall 11, sealant is applied only between the battery module 3 and the three side walls of the first peripheral wall 11. Sealant is also applied between the side of the battery module 3 and the bottom wall 13.

[0081] The sealant can prevent the gas generated by the cell 31 during thermal runaway from spreading out from the side or bottom of the cell, so as to ensure that the gas generated by the battery pack during thermal runaway can only be discharged through the third exhaust channel 3a, the first exhaust channel 1a, and the second exhaust channel 2a in sequence.

[0082] Furthermore, such as Figure 2 and Figure 3As shown, the upper cover 2 includes a second peripheral wall 21, a second top wall 22, and a partition 23. The partition 23 is connected to the second peripheral wall 21 and the second top wall 22. The space formed by the upper cover 2 and the first top wall 12 is divided into a second exhaust channel 2a and an electrical compartment 2b. The electrical compartment 2b is used to house electronic components that control the operation of the battery pack and communicate with the vehicle.

[0083] The second peripheral wall 21 also includes four side walls connected end to end in sequence. The electrical compartment 2b is surrounded by the three side walls of the second peripheral wall 21, the second top wall 22, the partition 23, and the first top wall 12. Among them, the partition 23 can prevent the gas in the second exhaust channel 2a from spreading to the electrical compartment 2b, and the first top wall 12 can prevent the gas in the first exhaust channel 1a and the third exhaust channel 3a from spreading to the electrical compartment 2b. In the event of thermal runaway of the battery pack, this can avoid or delay the damage to the electronic components in the electrical compartment 2b, and enable the electronic components to promptly feed back the thermal runaway signal to the vehicle's alarm system, giving the driver time to leave and protecting the vehicle from being burned by the entire battery pack catching fire and exploding.

[0084] Preferably, the first top wall 12 can be an insulating board made of polycarbonate (PC).

[0085] Furthermore, such as Figure 3 and Figure 8 As shown, a connecting groove 231 is provided on the partition 23, which connects the second exhaust channel 2a and the electrical compartment 2b; as Figure 7 As shown, the battery module 3 includes an electrical connector 4. One end of the electrical connector 4 is connected to the battery cell 31, and the other end extends into the electrical compartment 2b through the first connecting hole 1b and the connecting groove 231. By providing the connecting groove 231, the battery module 3 can communicate with the electronic components in the electrical compartment 2b through the electrical connector 4.

[0086] like Figure 8 As shown, two connecting channels 231 can be provided at intervals, and the partition 23 abuts against the first top wall 12, thereby reducing the gas flow between the second exhaust channel 2a and the electrical compartment 2b.

[0087] Optionally, a gap exists between the partition 23 and the first top wall 12, through which the electrical connector 4 extends into the electrical compartment 2b, thus eliminating the need for a connecting slot 231 on the partition 23. Meanwhile, to reduce gas flow between the second exhaust passage 2a and the electrical compartment 2b, the size of this gap should not exceed 10 mm, and preferably is less than 5 mm.

[0088] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A battery pack, characterized in that, The battery pack includes a housing and a battery module (3). The housing includes a bottom shell (1) and a top cover (2). The battery module (3) is installed inside the housing. The bottom shell (1) has a first peripheral wall (11) and a first top wall (12), the first top wall (12) separating the bottom shell (1) and the top cover (2) into independent internal cavities; The top of the battery module (3) has a first exhaust channel (1a) between the top of the battery module (3) and the first peripheral wall (11) of the bottom shell (1), and the top cover (2) has a second exhaust channel (2a). The first top wall (12) has a first connecting hole (1b) that connects the first exhaust passage (1a) and the second exhaust passage (2a).

2. The battery pack according to claim 1, characterized in that, The battery module (3) includes a battery cell (31), and a plurality of the battery cells (31) are stacked along their thickness direction. A first heat insulation member (32) is provided between adjacent battery cells (31), and the first heat insulation member (32) extends to the top of the battery cell (31). The battery cell (31) has a body (311) and a shoulder (312). A second heat insulation member (33) is disposed on the surface of the shoulder (312) near the first heat insulation member (32). A third exhaust channel (3a) is formed between the first heat insulation member (32) and the second heat insulation member (33) at an interval. The third exhaust channel (3a) can communicate with the first exhaust channel (1a).

3. The battery pack according to claim 2, characterized in that, The first exhaust channel (1a) extends along the thickness direction of the cell (31) on the outer side of the top position of the battery module (3), and the third exhaust channel (3a) is spaced along the thickness direction of the cell (31) on the inner side of the top position of the battery module (3).

4. The battery pack according to claim 2, characterized in that, The second heat insulation member (33) has a first bend (331) that abuts against the surface of the body (311) toward the shoulder (312).

5. The battery pack according to claim 2, characterized in that, The battery module (3) includes a data acquisition module (34), which is located on the side of the battery cell (31) near the first exhaust channel (1a). The acquisition module (34) has a second connecting hole (341), which connects the first exhaust channel (1a) and the third exhaust channel (3a).

6. The battery pack according to claim 5, characterized in that, The acquisition module (34) is provided with a third heat insulation component (35) on the side away from the battery cell (31). The third heat insulation component (35) is provided with an opening (351), and the opening (351) is provided in correspondence with the second connecting hole (341). The third heat insulation member (35) has a second bend (352) at the opening (351), the second bend (352) bends toward the direction of the battery cell (31).

7. The battery pack according to claim 6, characterized in that, The first heat insulation element (32), the second heat insulation element (33) and the third heat insulation element (35) are respectively selected from aerogel felt, mica tape or ceramicized silicone rubber.

8. The battery pack according to any one of claims 1-7, characterized in that, The battery module (3) has sealant between its sides and bottom and the first peripheral wall (11).

9. The battery pack according to any one of claims 1-7, characterized in that, The upper cover (2) includes a second peripheral wall (21), a second top wall (22) and a partition (23). The partition (23) is connected to the second peripheral wall (21) and the second top wall (22). The space formed by the upper cover (2) and the first top wall (12) has a second exhaust channel (2a) and an electrical compartment (2b).

10. The battery pack according to claim 9, characterized in that, The partition (23) is provided with a connecting groove (231), which connects the second exhaust channel (2a) and the electrical compartment (2b). The battery module (3) includes a battery cell (31) and an electrical connector (4). One end of the electrical connector (4) is connected to the battery cell (31), and the other end extends into the electrical compartment (2b).

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