Battery cell, battery pack and vehicle
By creating a venting channel in a thin area of a protective film inside the battery cell casing, the risk of explosion during battery thermal runaway is mitigated, thus improving battery safety.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-25
- Publication Date
- 2026-03-27
AI Technical Summary
The safety of existing battery packs needs to be improved, especially given the high risk of explosion during battery thermal runaway.
A protective film is provided inside the casing of the battery cell. The protective film includes a first region and a second region with different thicknesses. The second region is thinner than the first region. This is used to form an exhaust channel and balance the internal pressure in the event of thermal runaway.
By creating venting channels, the risk of battery cell and battery pack explosions is reduced, thus improving battery safety.
Smart Images
Figure CN224053161U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present disclosure relates to the technical field of batteries, in particular to a battery cell, a battery pack and a vehicle. BACKGROUND
[0002] With the continuous development of electric vehicles, the safety of electric vehicles has become a special concern of users, and the battery is one of the main factors affecting the safety of electric vehicles.
[0003] The safety of the existing battery pack needs to be improved.
[0004] It should be noted that the information disclosed in the above background section is only used to strengthen the understanding of the background of the present disclosure, and therefore can include information that does not constitute prior art known to those of ordinary skill in the art. SUMMARY
[0005] The present disclosure provides a battery cell, a battery pack and a vehicle, which can improve the safety of the battery.
[0006] According to a first aspect of the present disclosure, a battery cell is provided, comprising:
[0007] a housing;
[0008] a winding core arranged in the housing, the winding core comprising a first end face, a second end face and an outer peripheral surface, the first end face and the second end face being connected by the outer peripheral surface;
[0009] a protective film arranged in the housing and covering at least the outer peripheral surface, the protective film comprising a first region and a second region, the film thickness of the second region being thinner than that of the first region, the second region being used to form an exhaust passage when the battery cell is in thermal runaway.
[0010] In an embodiment of the present disclosure, the second region is arranged opposite to the outer peripheral surface.
[0011] In an embodiment of the present disclosure, the film thickness of the second region is 5% to 95% of the film thickness of the first region.
[0012] In an embodiment of the present disclosure, the number of the second regions is multiple, the multiple second regions are arranged in an array, and at least one of the second regions is arranged in a closed graphic shape.
[0013] In an embodiment of the present disclosure, the protective film comprises a connecting end film and a peripheral film, the end film is attached to the first end surface, the peripheral film is attached to the peripheral surface, and the second region is located on the peripheral film; the peripheral film comprises two oppositely arranged front surfaces and two oppositely arranged side surfaces, the front surfaces and the side surfaces are alternately distributed along the circumferential direction of the peripheral film, and the second region is arranged on the side surface, and the area of one second region is 0.1% to 50% of the area of one side surface.
[0014] In an embodiment of the present disclosure, the second region extends from the second end surface to the first end surface, and the first region and the second region are alternately distributed along the circumferential direction of the peripheral surface.
[0015] In an embodiment of the present disclosure, the size of the second region is 5% to 100% of the distance from the second end surface to the first end surface.
[0016] In an embodiment of the present disclosure, the second region is arranged in a straight line, and the size of the second region is equal to the distance from the second end surface to the first end surface.
[0017] In an embodiment of the present disclosure, the battery monomer further comprises an explosion-proof valve, the explosion-proof valve is arranged on the shell, and the shell and the protective film have a ventilation gap therebetween, and the explosion-proof valve is in communication with the ventilation gap.
[0018] In an embodiment of the present disclosure, the second region is arranged opposite to the explosion-proof valve.
[0019] According to a second aspect of the present disclosure, a battery pack is also provided, comprising the battery monomer of any of the above embodiments.
[0020] According to a third aspect of the present disclosure, a vehicle is also provided, comprising the battery pack of any of the above embodiments.
[0021] The battery monomer, the battery pack and the vehicle of the present disclosure have the following advantages: the shell is arranged with the winding core, the winding core is coated with the protective film, the first region and the second region are arranged on the protective film, the thickness of the second region is thinner than that of the first region, when excessive gas pressure is generated in the winding core, the protective film where the second region is located is broken, thereby forming an exhaust passage, the high pressure in the winding core can be balanced through the exhaust passage, the risk of explosion of the winding core is reduced, the safety of the battery monomer is improved, and the safety of the battery pack is improved.
[0022] It should be understood that the foregoing general description and the following detailed description are only exemplary and explanatory, and cannot limit the present disclosure. BRIEF DESCRIPTION OF DRAWINGS
[0023] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and serve to explain the principles of the present disclosure. It is apparent that the accompanying drawings, which are described below, are only some embodiments of the present disclosure, and other drawings can be obtained from these drawings without creative labor for those skilled in the art.
[0024] Figure 1 A schematic view of a structure of a battery cell in one embodiment of the present disclosure.
[0025] Figure 2 A schematic view of a structure of a battery cell in one embodiment of the present disclosure. Figure 1 A cross-sectional view of a first perspective of a battery cell in one embodiment of the present disclosure.
[0026] Figure 3 A cross-sectional view of a second perspective of a battery cell in one embodiment of the present disclosure. Figure 1 A cross-sectional view of a second perspective of a battery cell in one embodiment of the present disclosure.
[0027] Figure 4 A schematic view of a side of a battery cell in one embodiment of the present disclosure, intended to illustrate a second region.
[0028] Figure 5 A schematic view of a side of a battery cell in one embodiment of the present disclosure, intended to illustrate a second region.
[0029] BRIEF DESCRIPTION OF DRAWINGS
[0030] 1: housing; 2: roll core; 3: protective film; 31: first region; 32: second region; 4: bottom support sheet. DETAILED DESCRIPTION
[0031] Example embodiments now will be described more fully hereinafter with reference to the accompanying drawings; however, these embodiments can be implemented in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the example embodiments to those skilled in the art. Like reference numerals refer to like elements throughout the specification. Additionally, the drawings are merely schematic and are not drawn to scale.
[0032] The terms "one", "a", "an", "the", and "at least one" are used to mean that "one or more" of something is present; the terms "comprising" and "having" are used to mean "including" and mean the inclusion of something not limited to the steps, elements, and / or components listed or discussed; and the use of "first", "second", and "third" and / or "and / or" used in the description are only to distinguish one element from another, and are not necessarily used to describe a number sequence.
[0033] In this document, "film thickness" refers to the thickness of the protective film.
[0034] In an electric vehicle, when the winding core of a battery cell is in thermal runaway, excessive pressure is generated inside the battery cell, which has the risk of explosion.
[0035] To solve the above problems, the present disclosure provides a battery cell. Referring to Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 The battery cell includes a shell 1, a winding core 2, and a protective film 3. The winding core 2 is arranged in the shell 1, and the winding core 2 includes a first end face, a second end face, and an outer peripheral surface, and the first end face and the second end face are connected by the outer peripheral surface. The protective film 3 is arranged in the shell 1 and at least covers the outer peripheral surface, and the protective film 3 includes a first region 31 and a second region 32, and the film thickness of the second region 32 is thinner than the film thickness of the first region 31, and the second region 32 is used to form an exhaust passage when the battery cell is in thermal runaway.
[0036] In an embodiment of the present disclosure, since the thickness of the second region 32 is thinner than the thickness of the first region 31, when excessive air pressure is generated inside the winding core 2, the protective film 3 where the second region 32 is located will be broken, thereby forming an exhaust passage, and the high pressure inside the winding core 2 can be balanced through the exhaust passage, reducing the risk of explosion of the winding core 2 and improving the safety of the battery cell.
[0037] In an embodiment of the present disclosure, the shell 1 is in a cubic structure, and the shell 1 is hollow to facilitate the arrangement of the winding core 2 and the protective film 3 in the shell 1. Further, the material of the shell 1 can be aluminum, which is beneficial to the lightweight of the battery cell.
[0038] The shell 1 is provided with a first electrode and a second electrode, and the first electrode and the second electrode are located on the same side of the shell 1 and extend into the shell 1, and the first electrode and the second electrode are electrically connected with the winding core 2 respectively. One of the first electrode and the second electrode is a positive electrode, and the other is a negative electrode.
[0039] In other embodiments, the first electrode and the second electrode can also be located on both sides of the shell 1, the first electrode can be electrically connected with the first end face, the second electrode can be electrically connected with the second end face, or the first electrode can be electrically connected with the second end face, and the second electrode can be electrically connected with the first end face. In this embodiment, the protective film 3 can surround and cover the outer peripheral surface, and the protective film 3 can not be arranged on the first end face and the second end face.
[0040] In an embodiment of the present disclosure, the shape of the winding core 2 can be cylindrical, prismatic, or irregular. The structure of the shell 1 can also be other shapes, such as cylindrical, prismatic, or other shapes.
[0041] In an embodiment of the present disclosure, the first end face, the outer peripheral face, and the second end face are sequentially arranged along a length direction of the battery cell, and the protective film 3 is arranged around the outer peripheral face. In this way, the battery cell can be a blade battery cell. In another embodiment of the present disclosure, the first end face, the outer peripheral face, and the second end face are sequentially arranged along a height direction of the battery cell, and the protective film 3 is arranged around the outer peripheral face and the second end face. In this way, the battery cell can be a square battery cell. It should be noted that the length direction and the height direction of the battery cell are perpendicular to each other.
[0042] In an embodiment of the present disclosure, the material of the protective film 3 can be PPT plastic material or PET (polyethylene terephthalate) material, so that the protective film 3 has good insulation and thermoplasticity. The film thickness of the protective film 3 can be 0.1 mm to 0.15 mm. For example, the film thickness of the protective film 3 can be 0.1 mm, 0.11 mm, 0.12 mm, 0.13 mm, 0.14 mm, or 0.15 mm.
[0043] In an embodiment of the present disclosure, the second region 32 is arranged opposite to the outer peripheral face. In other words, referring to Figure 2 , the protective film 3 includes an end film and a peripheral film which are integrally connected. The end film is attached to the first end face, and the peripheral film is attached to the outer peripheral face, so as to encapsulate and protect the winding core 2.
[0044] In an embodiment of the present disclosure, referring to Figure 2 , Figure 4 and Figure 5 , the second region 32 is located on the peripheral film, and the film thickness of the first region 31 is greater than that of the second region 32. The first region 31 is a region of the protective film 3 except the second region 32, and the film thickness of the second region 32 is 5% to 95% of the film thickness of the first region 31. For example, the film thickness of the second region 32 is 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, or 95% of the film thickness of the first region 31. In this way, the film thickness of the second region 32 is not 0. On the one hand, the second region 32 does not affect the encapsulation and protection of the winding core 2 by the protective film 3. On the other hand, when high-pressure gas is generated in the winding core 2, the protective film 3 of the second region 32 can be broken under the action of the high-pressure gas to form an exhaust passage, so as to facilitate the balance of the gas pressure in the winding core 2 and reduce the possibility of explosion of the winding core 2.
[0045] In one embodiment of the present disclosure, the number of the second regions 32 is multiple, and the multiple second regions 32 are arranged in an array. At least one of the second regions 32 is arranged in a closed figure. For example, the closed figure can be a circle, an ellipse, a triangle, a quadrilateral, a polygon, or an irregular closed figure.
[0046] In one example, referring to FIG. 1, the second region 32 can be a notch, and the notch can be a circle, an ellipse, a triangle, a quadrilateral, a polygon, or an irregular closed figure. Figure 4 In another example, referring to FIG. 2, the second region 32 can be a recessed region, and the recessed region has a bottom and a side, and the side and the bottom form a recessed cavity.
[0047] In one embodiment of the present disclosure, the peripheral film includes two opposite front faces and two opposite sides, and the front faces and the sides are alternately arranged along the circumferential direction of the peripheral film. That is, the peripheral film has a cubic structure. The area of one front face is at least five times the area of one side. The second region 32 is arranged on the side, and the area of one second region 32 is 0.1% to 50% of the area of one side. For example, the area of one second region 32 is 0.1%, 5.1%, 10.1%, 15.1%, 20%, 25.1%, 30.1%, 35.1%, 40.1%, 45.1%, or 50% of the area of one side. In this way, the area of the side occupied by the second region 32 can be prevented from being too large, so as to improve the strength of the protective film 3.
[0048] In one embodiment of the present disclosure, the number of the second regions 32 is four, two of the second regions 32 are arranged on one side, and the other two of the second regions 32 are arranged on the other side. Referring to FIG. 3, the two second regions 32 on the same side are spaced apart along the axial direction of the winding core 2. Figure 4 In one example, referring to FIG. 1, the second region 32 can be a notch, and the notch can be a circle, an ellipse, a triangle, a quadrilateral, a polygon, or an irregular closed figure.
[0049] In one embodiment of the present disclosure, the second region 32 extends from the second end face to the first end face, and the first region 31 and the second region 32 are alternately arranged along the circumferential direction of the peripheral film. For example, the second region 32 is a notch, and the trace of the notch is a straight line, a curve, a broken line, or a combination of a straight line, a curve, and a broken line. In other words, the second region 32 is a non-closed figure, and the second region 32 is arranged on the side.
[0050] In an embodiment of the present disclosure, the size of the second region 32 is 5% to 100% of the interval between the second end face and the first end face. For example, the size of the second region 32 is 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, or 100% of the interval between the second end face and the first end face. The size of the second region 32 is the length of the extension track of the second region 32.
[0051] In an embodiment of the present disclosure, the number of the second regions 32 is four, two of the second regions 32 are located on one side face, and the other two of the second regions 32 are located on the other side face, and the second regions 32 are spaced apart along the circumference of the core 2. Referring to Figure 5 The second region 32 is a notch, the notch is arranged in a straight line, the length of the notch is equal to the interval between the second end face and the first end face, and the film thickness of the notch is 60% of the film thickness of the first region 31.
[0052] In an embodiment of the present disclosure, the battery monomer further comprises an explosion-proof valve, which can be arranged on the shell 1. The shell 1 and the protective film 3 have a ventilation gap, and the explosion-proof valve is in communication with the ventilation gap. In this way, when high-pressure gas is generated inside the core 2, the protective film 3 of the second region 32 can be broken under the action of the high-pressure gas to form an exhaust passage, and the high-pressure gas inside the core 2 can pass through the exhaust passage, the ventilation gap, and finally be discharged from the explosion-proof valve, improving the smoothness of the discharge of the gas inside the core 2 and being beneficial to improving the safety of the battery monomer.
[0053] It can be understood that the position of the explosion-proof valve can be arranged at any position of the shell 1, for example, it can be the circumferential side of the shell 1 or the end face of the shell 1, as long as the design requirement is met.
[0054] In an embodiment of the present disclosure, the second region 32 is arranged opposite to the explosion-proof valve. In this way, the interval between the second region 32 and the explosion-proof valve can be shortened, so that the high-pressure gas generated inside the core 2 can be quickly discharged through the explosion-proof valve, further improving the safety.
[0055] In an embodiment of the present disclosure, referring to Figure 2 The shell 1 is provided with a bottom support sheet 4, the bottom support sheet 4 is located between the end film and the shell 1, and the bottom support sheet 4 can be attached to the end film, so that the core 2 is fixed in the shell 1.
[0056] In an embodiment, when the explosion-proof valve is arranged on the surface opposite to the bottom support sheet 4 of the shell 1, a communication passage can be arranged on the bottom support sheet 4 to communicate the explosion-proof valve and the second region 32, which is beneficial to the discharge of the high-pressure gas when the battery monomer is in thermal runaway.
[0057] In an embodiment of the present disclosure, a connecting glue can be arranged between the top film and the inner wall of the shell 1, further facilitating the fixation of the roll core 2 in the shell 1.
[0058] The present disclosure also provides a battery pack, which can include a box body and the plurality of battery cells according to any one of the above embodiments, and the plurality of battery cells are fixed in the box body. The battery pack has all the beneficial effects of the above battery cells.
[0059] The present disclosure also provides a vehicle, which can include the battery pack according to any one of the above embodiments. The vehicle has all the beneficial effects of the above battery pack. The vehicle can be a new energy vehicle, an engineering vehicle, a truck, a van, an electric bicycle, etc., and the new energy vehicle can be a pure electric vehicle, a hybrid vehicle, or a range extended vehicle, etc., and the embodiments of the present disclosure do not make special restrictions on the above vehicles.
[0060] Other embodiments of the present disclosure will be apparent to those skilled in the art upon consideration of the specification and practice of the present disclosure. The present disclosure is intended to cover any variations, uses, or adaptations of the present disclosure following the general principles thereof and including modifications and equivalents of the present disclosure that are obvious to those skilled in the art. The specification and examples are to be regarded as illustrative only, and the true scope and spirit of the present disclosure are indicated by the appended claims.
Claims
1. A battery cell, characterized by, The battery monomer comprises: a shell; a winding core arranged in the shell, the winding core comprising a first end face, a second end face and an outer peripheral surface, the first end face and the second end face being connected by the outer peripheral surface; a protective film arranged in the shell and covering at least the outer peripheral surface, the protective film comprising a first region and a second region, the second region having a film thickness thinner than that of the first region, the second region being used to form an exhaust passage when the battery monomer is in thermal runaway.
2. The battery cell of claim 1, wherein, The second region is arranged opposite to the outer peripheral surface.
3. The battery cell of claim 1, wherein, The film thickness of the second region is 5% to 95% of the film thickness of the first region.
4. The battery cell of claim 1, wherein, The number of the second regions is multiple, and the multiple second regions are arranged in an array, at least one of the second regions being arranged in a closed pattern.
5. The battery cell of claim 1, wherein, The protective film comprises a connecting end film and a peripheral film, the end film being attached to the first end face, the peripheral film being attached to the outer peripheral surface, and the second region being located in the peripheral film; the peripheral film comprises two oppositely arranged front faces and two oppositely arranged side faces, the front faces and the side faces being alternately distributed along the circumferential direction of the peripheral film, the second region being arranged on the side face, and the area of one second region being 0.1% to 50% of the area of one side face.
6. The battery cell of claim 1, wherein, The second region extends from the second end face to the first end face, and the first region and the second region are alternately distributed along the circumferential direction of the outer peripheral surface.
7. The battery cell of claim 6, wherein, The size of the second region is 5% to 100% of the distance between the second end face and the first end face.
8. The battery cell of claim 6, wherein, The second region is arranged in a straight line, and the size of the second region is equal to the distance between the second end face and the first end face.
9. The battery cell according to any one of claims 1 to 8, characterized in that The battery monomer further comprises an explosion-proof valve arranged in the shell, and the shell and the protective film have a ventilation gap therebetween, the explosion-proof valve being in communication with the ventilation gap.
10. The battery cell of claim 9, wherein, The second region is arranged opposite to the explosion-proof valve.
11. A battery pack, characterized by The battery monomer comprises any one of claims 1 to 10.
12. A vehicle characterized by comprising: The battery pack comprises the battery monomer of claim 11.