Battery cell, battery module and battery pack
By setting an aerogel heat insulator between the electrode core of the battery core and the shell weld, the problem of the electrode core ejecting the shell when the battery core is thermally out of control is solved, and the effect of reducing weld cracking and core ejection is achieved.
Patent Information
- Application Number
- CN202421263125.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-04
- Publication Date
- 2025-03-18
- Estimated Expiration
- 2034-06-04
AI Technical Summary
The existing battery cells are prone to the problem of the extreme core ejecting the shell when thermally out of control, and the existing thermal insulation measures cannot effectively delay this process.
Aerogel heat insulator is provided between the electrode core and the weld of the shell to delay the steep temperature rise of the battery core at the weld and heat conduction, thereby avoiding the instantaneous cracking of the shell weld.
It effectively reduces the probability of weld cracking and core ejection, extends the time of gas discharge in the battery cell, reduces internal pressure, and improves the safety of the battery cell.
Smart Images
Figure CN222637426U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of battery technology, and specifically provides a battery cell, a battery module and a battery pack. Background Art
[0002] In the prior art, battery packs usually have aerogel insulation sheets between the surfaces outside the shells of adjacent single-cell batteries to reduce heat transfer between the cells and to prevent flame retardancy. However, when thermal runaway occurs in a single cell, the aerogel insulation sheet can only delay the conduction of heat over a large area, but cannot delay the core of the thermal runaway cell from being ejected from the shell. Summary of the invention
[0003] The present application aims to solve the above technical problem, that is, to solve the problem in the prior art that the battery cell pole core is easily ejected from the shell in the case of thermal runaway.
[0004] The present application provides a battery cell, comprising a shell, a pole core and an aerogel insulation sheet, wherein the shell is arranged around the pole core, a weld is formed on the shell, and the aerogel insulation sheet is arranged between the pole core and the weld.
[0005] In the optional technical solution of the above-mentioned battery cell, it also includes a pole core protection film, which is arranged around the pole core and between the pole core and the shell, and the pole core protection film is arranged in contact with the aerogel insulation sheet.
[0006] In an optional technical solution of the above-mentioned battery cell, the pole core protection film includes a first end and a second end, the first end is arranged on the first surface of the pole core, the pole core protection film surrounds the pole core so that the second end is overlapped and arranged on the first end, the weld is opposite to the first surface of the pole core, the aerogel insulation sheet is arranged between the first end and the second end, or, the aerogel insulation sheet is arranged between the weld and the second end, or, the aerogel insulation sheet is arranged between the first end and the pole core.
[0007] In the optional technical solution of the above battery cell, the thickness of the aerogel thermal insulation sheet is not less than 0.3 mm and not more than 0.5 mm.
[0008] In the optional technical solution of the above-mentioned battery cell, the aerogel insulation sheet is one of pre-oxidized silk aerogel felt, flexible insulation felt or insulation sheet.
[0009] The present application also provides a battery module, which includes a battery cell according to any one of the above technical solutions.
[0010] In an optional technical solution of the above battery module, a plurality of battery cells are provided, and the aerogel insulation sheet is provided between adjacent battery cells.
[0011] The present application also provides a battery pack, which includes the battery cell described in any one of the above technical solutions, or the battery pack includes the battery module described in any one of the above technical solutions.
[0012] In the case of adopting the above-mentioned technical solution, the present application arranges an aerogel insulation sheet between the weld of the pole core and the shell. When a single battery cell thermally runs away, the aerogel insulation sheet can delay the temperature rise and heat conduction of the battery cell at the weld, avoiding the instantaneous cracking of the weld of the shell, thereby reducing the probability of weld cracking and pole core ejection. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] BRIEF DESCRIPTION OF THE DRAWINGS The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application.
[0014] The preferred embodiments of the present application are described below in conjunction with the accompanying drawings, in which:
[0015] Figure 1 is a schematic diagram of a battery cell of the present application;
[0016] Figure 2 yes Figure 1 Exploded view of the battery cell;
[0017] Figure 3 It is a schematic diagram of the aerogel insulation sheet of the battery cell of the present application being located between the first end and the second end of the pole core protection film;
[0018] Figure 4 It is a schematic diagram showing that the aerogel insulation sheet of the battery cell of the present application is located on the upper side of the pole core protective film.
[0019] List of reference numerals:
[0020] 1. Battery cell; 11. Electrode core; 111. First side; 112. Second side; 113. Third side; 12. Shell; 121. Weld; 13. Electrode core protective film; 131. First end; 132. Second end; 14. Aerogel thermal insulation sheet. DETAILED DESCRIPTION
[0021] Exemplary embodiments will be described in detail herein, examples of which are illustrated in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numerals in different drawings represent the same or similar elements.
[0022] The words "first", "second", "third" and the like used in the specification and claims of this application do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, "plurality" means two or more.
[0023] Unless otherwise specified, the orientations or positional relationships indicated by "length", "width", "up", "down", "inside" and "outside" are based on the orientations or positional relationships shown in the drawings and are only for the convenience of describing the present application and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.
[0024] like Figure 1 As shown, the present application provides a battery cell 1. In order to clearly show the structure of the battery cell 1, Figure 2 The exploded view of the battery cell 1 is shown. The battery cell 1 includes a shell 12, a pole core 11 and an aerogel insulation sheet 14. The shell 12 is arranged around the pole core 11. A weld 121 is formed on the shell 12. The aerogel insulation sheet 14 is arranged between the pole core 11 and the weld 121. The overall effect of the battery cell 1 formed by the shell 12 is as follows Figure 1 As shown, at this time, the aerogel insulation sheet 14 is hidden in the shell 12. The thermal runaway of the battery cell 1 in the prior art is mainly manifested in the generation of heat under violent reaction, rapid temperature rise, and rapid increase in internal air pressure. Under the dual effects of high temperature and pressure, the weld 121 of the shell 12 of the battery cell 1 is easy to crack and eject the pole core 11. In the present application, the aerogel insulation sheet 14 is arranged between the weld 121 and the pole core 11. When the abnormality of the battery cell 1 causes thermal runaway, the aerogel insulation sheet 14 arranged at the weld 121 can delay the temperature rise at the weld 121 and prevent the pole core 11 from conducting heat to the weld 121, thereby avoiding the problem of instantaneous cracking at the weld 121 when the battery cell 1 is in thermal runaway. Since the aerogel insulation sheet 14 delays the temperature rise and heat conduction at the weld 121, the time for the gas inside the battery cell 1 to be discharged to the explosion-proof valve of the battery cell 1 is extended, and the pressure inside the battery cell 1 can be reduced. At this time, the probability of the weld 121 cracking and the pole core 11 ejecting is greatly reduced. In addition, since the time of the shell 12 cracking is delayed, the above-mentioned thermal runaway problem can be promptly warned to the staff at the beginning, and sufficient time can be provided for the staff to take corresponding measures.
[0025] In one embodiment, if Figure 2 As shown, the battery cell 1 further includes a core protection film 13, which is disposed around the core 11 (eg Figure 3As shown) and arranged between the pole core 11 and the shell 12, the pole core protection film 13 is arranged in affixed with the aerogel insulation sheet 14. When the battery cell 1 also includes the pole core protection film 13, since the aerogel insulation sheet 14 arranged between the pole core 11 and the weld 121 of the shell 12 can insulate and reduce heat transfer, the pole core protection film 13 can also play a certain role in heat insulation and protection of the pole core 11. Therefore, when the battery cell 1 abnormally causes thermal runaway, the possibility of instantaneous cracking at the weld 121 is further reduced. In addition, the aerogel insulation sheet 14 is arranged in affixed with the pole core protection film 13, which can be formed by hot melt bonding, tape bonding or glue bonding.
[0026] In one embodiment, if Figure 3 As shown, the pole core protection film 13 includes a first end 131 and a second end 132, the first end 131 is arranged on the first surface 111 of the pole core 11, the pole core protection film 13 surrounds the pole core 11 so that the second end 132 is superimposed on the first end 131, the weld 121 is opposite to the first surface 111 of the pole core 11, and the aerogel insulation sheet 14 can be arranged between the first end 131 and the second end 132 (such as Figure 3 As shown), at this time, the first end 131 and the second end 132 sandwich the aerogel insulation sheet 14 in the middle to better protect the aerogel insulation sheet 14 from damage, and at the same time, the aerogel insulation sheet 14 can be connected to the pole core protection film 13 on both sides to form a stable connection. The aerogel insulation sheet 14 can also be arranged between the weld 121 and the second end 132 (as shown Figure 4 As shown, in order to conveniently show the position of the aerogel insulation sheet 14 while preventing the aerogel insulation sheet 14 from being blocked by the weld 121, Figure 4 Only the aerogel insulation sheet 14 is shown to be arranged above the pole core protection film 13, and the shell 12 and the weld 121 are not shown. The aerogel insulation sheet 14 can also be arranged between the first end 131 and the pole core 11, but the above arrangement is not shown in the figure. The first end 131, the second end 132 and the aerogel insulation sheet 14 of the pole core protection film 13 are arranged on the first surface 111 and correspond to the weld 121, which can further reduce the possibility of the weld 121 breaking when the battery cell 1 is thermally runaway.
[0027] It should be noted that the core protection film 13 can be in the form of the first end 131 and the second end 132 described above being stacked up and down (such as Figure 3As shown), of course, the ends of the first end 131 and the second end 132 may be connected but not overlapped. For example, the edges of the first end 131 and the second end 132 are connected so that the pole core protection film 13 is arranged in a ring shape around the pole core 11. At this time, only the first end 131 is arranged on the first surface 111 of the pole core 11, and the second end 132 is arranged on the side adjacent to the first surface 111. At this time, the aerogel insulation sheet 14 is located between the first end 131 and the pole core 11, or, between the first end 131 and the weld 121 of the shell 12. The above is not restrictive and can be arranged according to the needs of technicians in this field. The above are all within the protection scope of the present application.
[0028] In one embodiment, the thickness of the aerogel insulation sheet 14 is not less than 0.3 mm and not more than 0.5 mm, and the above thickness can better block the heat generated by thermal runaway of the battery cell 1, while also preventing waste due to excessive thickness of the aerogel insulation sheet 14.
[0029] In one embodiment, the aerogel thermal insulation sheet 14 is one of pre-oxidized silk aerogel felt, flexible thermal insulation felt or thermal insulation sheet, wherein the pre-oxidized silk aerogel felt is formed by composite silica aerogel with pre-oxidized silk fiber as the base material, the flexible thermal insulation felt is formed by composite aerogel with wet glass fiber felt as the base material, and the thermal insulation sheet is formed by composite silica aerogel with ceramic fiber as the base material. The aerogel thermal insulation sheet 14 can produce a good thermal insulation effect through the above materials, thereby reducing the possibility of instantaneous cracking of the weld 121 when thermal runaway occurs in the battery cell 1.
[0030] In one embodiment, there are some battery cells 1 with light weight and long length, and the volume utilization rate of the module formed by the above battery cells 1 is high. When the battery cell 1 is long, the corresponding pole core 11 is also long. Therefore, the shell 12 corresponding to the pole core 11 cannot be formed by conventional stamping, and can only be formed by bending a thin plate and then laser welding to form the shell 12. The shell 12 is generally an aluminum shell, and the weld 121 is located at the long narrow side of the aluminum shell. The main manifestation of thermal runaway of the battery cell 1 monomer is heat generation under violent reaction, rapid temperature rise, and rapid increase in internal air pressure. Under the dual effects of high temperature and pressure, the aluminum shell weld 121 is easy to crack and eject the pole core 11. The aerogel insulation sheet 14 is arranged between the pole core 11 and the weld 121 of the aluminum shell, which can also delay the temperature rise at the weld 121 and prevent the pole core 11 from conducting heat to the weld 121, thereby avoiding the problem of instantaneous cracking at the weld 121 when the battery cell 1 is thermally runaway.
[0031] In one embodiment, if Figure 3As shown, when the battery cell 1 is set as a rectangular parallelepiped, the corresponding pole core 11 is also set as a rectangular parallelepiped. The pole core 11 includes a first surface 111 opposite to the weld 121, a second surface 112 and a third surface 113 adjacent to the first surface 111. The lengths of the first surface 111, the second surface 112 and the third surface 113 are equal and are all L. The above three surfaces are all arranged in contact with the pole core protection film 13. The width W1 of the first surface 111 is smaller than the width W2 of the second surface 112 and the width W2 of the third surface 113. Since the second surface 112 and the third surface 113 are opposite to each other in the rectangular parallelepiped, the widths of the two surfaces are equal and are all W2. Therefore, Figure 3 Only the width W2 of the third surface 113 is marked. When the pole core 11 is long, the shell 12 cannot be formed by conventional stamping, and can only be formed by bending a thin plate and then laser welding to form the shell 12. The weld 121 is located on the long narrow side of the shell 12. Therefore, the surface of the pole core 11 corresponding to the long narrow side should be the first surface 111 with a smaller width. At this time, an aerogel insulation sheet 14 is arranged between the first surface 111 of the pole core 11 of the battery cell 1 and the weld 121. The aerogel insulation sheet 14 is arranged between the weld 121 and the first surface 111 with a smaller width, which can reduce the use size of the aerogel insulation sheet 14, thereby reducing the cost to a certain extent.
[0032] In addition, the present application also provides a battery module, which has the battery cell 1 described in any of the above embodiments. The battery cell 1 of the battery module is provided with an aerogel insulation sheet 14 between the pole core 11 and the weld 121. When the battery cell 1 of the battery module has thermal runaway, the battery cell 1 provided with the aerogel insulation sheet 14 can reduce the possibility of instantaneous cracking at the weld 121 causing the pole core 11 to be ejected, thereby reducing the possibility of the pole core 11 being ejected and arcing with the metal parts of the battery module and breaking through the shell of the battery module, thereby reducing the possibility of violent combustion of the battery module.
[0033] In one embodiment, a plurality of battery cells 1 are provided, and an aerogel thermal insulation sheet 14 is also provided between adjacent battery cells 1. At this time, when a battery cell 1 has thermal runaway, the aerogel thermal insulation sheet 14 provided at the weld 121 can reduce the possibility of instantaneous cracking at the weld 121, and the aerogel thermal insulation sheet 14 provided between adjacent battery cells 1 can delay the conduction of heat in a large area, and at this time, the possibility of violent combustion of the battery module due to thermal runaway of the battery cell 1 can be further reduced.
[0034] The present application also provides a battery pack, which has the battery module described in any of the above embodiments, or the battery pack has the battery cell 1 described in any of the above embodiments.
[0035] It should be noted that the technical solutions or technical features described in the above embodiments can be combined or supplemented with each other without causing conflicts. The scope of protection of this application is not limited to the precise structures described in the above embodiments and shown in the drawings; all modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of this application should be included in the scope of protection of this application.
Claims
1. A battery cell, characterized in that: The invention comprises a shell, a pole core and an aerogel heat insulation sheet. The shell is arranged around the pole core. A welding seam is formed on the shell. The aerogel heat insulation sheet is arranged between the pole core and the welding seam.
2. The battery cell according to claim 1, characterized in that: It also includes a pole core protection film, which is arranged around the pole core and between the pole core and the shell, and the pole core protection film is bonded to the aerogel insulation sheet.
3. The battery cell according to claim 2, characterized in that: The pole core protection film includes a first end and a second end, the first end is arranged on the first surface of the pole core, the pole core protection film surrounds the pole core so that the second end is overlapped and arranged on the first end, the weld is opposite to the first surface of the pole core, and the aerogel insulation sheet is arranged between the first end and the second end, or, The aerogel heat insulation sheet is arranged between the weld and the second end, or, The aerogel thermal insulation sheet is arranged between the first end and the pole core.
4. The battery cell according to claim 2, characterized in that: The thickness of the aerogel thermal insulation sheet is not less than 0.3 mm and not more than 0.5 mm.
5. The battery cell according to any one of claims 1 to 4, characterized in that: The aerogel thermal insulation sheet is one of pre-oxidized silk aerogel felt, flexible thermal insulation felt or thermal insulation sheet.
6. A battery module, characterized in that: The battery module comprises the battery cell according to any one of claims 1 to 5.
7. The battery module according to claim 6, characterized in that: A plurality of battery cells are provided, and the aerogel heat insulation sheet is arranged between adjacent battery cells.
8. A battery pack, characterized in that: The battery pack includes the battery cell described in any one of claims 1 to 5, or the battery pack includes the battery module described in claim 6 or 7.