Battery cell and battery pack

Abstract

The utility model relates to battery technical field provides a kind of battery cell and battery package, above-mentioned battery cell includes: shell, pole group, explosion-proof valve, insulating film and side plate;Shell has accommodating cavity;Pole group is located in accommodating cavity;Explosion-proof valve is located in the width direction of shell one side;Insulating film is covered in pole group, and insulating film includes body, first lap and second lap, first lap and second lap are separately arranged in the two sides of body and are overlapped and are set, first lap and second lap are both provided with notch, two notches are oppositely arranged and are correspondingly arranged with explosion-proof valve;Side plate is located between pole group and insulating film, and located in the width direction of shell one side, and correspondingly arranged with explosion-proof valve, side plate is provided with first through-hole, and first through-hole forms exhaust passage with notch.The utility model's battery cell avoids that insulating film and side plate are blocked exhaust passage after deformation, improves the stability of battery cell internal exhaust, enhances the safety performance of battery cell.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to a battery cell and a battery pack. Background Technology

[0002] Current power battery structures typically place the electrode assembly inside the housing cavity. The electrode assembly is formed by stacking positive and negative electrode plates and a separator. After the electrode assembly is stacked, an insulating film is wrapped around the electrode assembly to achieve insulation of the entire cell.

[0003] Currently, the insulating film softens after being deformed by heat and adheres to the surface of the explosion-proof valve, blocking the valve's exhaust passage. Furthermore, the side plate melts when heated, which also blocks the exhaust passage, causing blockage and affecting the safety of the battery cell. Utility Model Content

[0004] This invention provides a battery cell and battery pack to solve the problem in the prior art where the insulation film and side plate melt when heated, blocking the exhaust channel and affecting the safety of the battery cell.

[0005] To solve the above-mentioned technical problems, this application is implemented as follows: In a first aspect, this utility model provides a battery cell, comprising: The shell has a receiving cavity; The pole assembly is disposed within the receiving cavity; An explosion-proof valve is located on one side of the housing in the width direction; An insulating film is provided to cover the electrode assembly. The insulating film includes a body, a first overlap and a second overlap. The first overlap and the second overlap are respectively disposed on both sides of the body and overlapped. Both the first overlap and the second overlap are provided with notches. The two notches are arranged opposite each other and correspond to the explosion-proof valve. A side plate is disposed between the electrode group and the insulating film or between the insulating film and the housing, and is located on one side of the housing in the width direction, and is correspondingly disposed to the explosion-proof valve. The side plate is provided with a first through hole, and the first through hole and the notch form an exhaust channel.

[0006] According to the present invention, the area of ​​the notch is larger than the venting area of ​​the explosion-proof valve.

[0007] According to the present invention, the notch has a first side and a second side, the first side extending along the length direction of the housing, and the second side extending along the width direction of the housing.

[0008] According to the present invention, the thickness of the insulating film is s, where s satisfies: 0.08mm≤s≤0.5mm.

[0009] According to the present invention, the side plate of the battery cell further includes: a second through hole; The second through hole is located beside the first through hole. Both the first through hole and the second through hole extend along the length of the housing and are connected.

[0010] According to the present invention, the side plate of the battery cell further includes: a third through hole; Along the length of the housing, the third through hole is located at the end of the side plate; The area of ​​the third through hole is smaller than the area of ​​the second through hole.

[0011] According to the present invention, a battery cell is provided in which creases are formed on the insulating film along the length direction of the housing to divide the body into a first part, a second part and a third part, and to separate the first overlap and the second overlap from the body; The first overlap, the first part, the second part, the third part, and the second overlap are connected in sequence.

[0012] According to the present invention, the insulating film further includes: a first positioning hole; The first positioning hole is provided on the first overlap and the second overlap; The side plate has a second positioning hole, which is positioned opposite to the first positioning hole.

[0013] According to the present invention, the insulating film and the side plate are thermally fused together to form an integral structure.

[0014] Secondly, this utility model provides a battery pack, comprising: a plurality of battery cells as described above.

[0015] The battery cell and battery pack provided by this utility model can mechanically support the electrode assembly by setting a side plate between the electrode assembly and the insulating film. A first through hole corresponding to the explosion-proof valve is set on the side plate. At the same time, the insulating film is provided with a body, a first overlap and a second overlap. Notches are set on the first overlap and the second overlap. After the first overlap and the second overlap overlap are joined, the two notches coincide and communicate with the first through hole to form an exhaust channel. After the insulating film and the side plate are heated and softened, high-temperature gas can be discharged from the containment cavity through the first through hole and the notch through the explosion-proof valve. This avoids the insulation film and the side plate from deforming and blocking the exhaust channel, improves the stability of the exhaust inside the battery cell, and enhances the safety performance of the battery cell. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is an exploded view of the battery cell provided by this utility model.

[0018] Figure 2 This is a three-dimensional structural diagram of the battery cell provided by this utility model.

[0019] Figure 3 This is a front view of the insulating film provided by this utility model.

[0020] Figure 4 This is a front view of the side provided by this utility model.

[0021] Figure label: 1. Housing; 2. Electrode assembly; 3. Explosion-proof valve; 4. Insulating film; 41. Body; 42. First overlap; 43. Second overlap; 44. Crease; 45. First positioning hole; 411. First part; 412. Second part; 413. Third part; 421. Notch; 4211. First side; 4212. Second side; 5. Side plate; 51. First through hole; 52. Second through hole; 53. Third through hole; 54. Second positioning hole; 6. Cover plate; 7. End plate; 8. Connecting piece; 9. Protective film. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0023] In the description of the embodiments of this utility model, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the purpose of clarifying the embodiments of this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this utility model. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0024] In the description of the embodiments of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this utility model according to the specific circumstances.

[0025] In this embodiment of the utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0026] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0027] The following is combined with Figures 1 to 4The present invention will provide a detailed description of the battery cell and battery pack provided in the embodiments of the present invention through specific implementation methods and application scenarios.

[0028] Firstly, such as Figure 1 , Figure 2 and Figure 3 As shown, this embodiment provides a battery cell, including: a housing 1, an electrode group 2, an explosion-proof valve 3, an insulating film 4, and a side plate 5.

[0029] The housing 1 has a receiving cavity; the pole group 2 is disposed in the receiving cavity; the explosion-proof valve 3 is disposed on one side of the housing 1 in the width direction.

[0030] The insulating film 4 covers the electrode assembly 2. The insulating film 4 includes a body 41, a first overlap 42 and a second overlap 43. The first overlap 42 and the second overlap 43 are respectively disposed on both sides of the body 41 and overlapped. Both the first overlap 42 and the second overlap 43 are provided with notches 421. The two notches 421 are arranged opposite each other and are corresponding to the explosion-proof valve 3.

[0031] The side plate 5 is located between the electrode group 2 and the insulating film 4 or between the insulating film 4 and the housing 1, and is located on one side of the width direction of the housing 1, and is corresponding to the explosion-proof valve 3. The side plate 5 is provided with a first through hole 51, and the first through hole 51 and the notch 421 form an exhaust channel.

[0032] Understandably, the battery cell housing 1 has an opening, and a cover plate 6 is placed over the opening. The housing 1 and the cover plate 6 together form a receiving cavity, and the tabs of the electrode group 2 are electrically connected to the cover plate 6. To achieve thermoelectric separation of the battery cell, the explosion-proof valve 3 in this embodiment is not located on the cover plate 6, but is located on one side of the housing 1 in the width direction. That is, when the high-temperature gas of the electrode group 2 is discharged through the explosion-proof valve 3, the path is different from the path through which the current is transmitted from the tabs to the poles on the cover plate 6. In order to discharge the gas when the electrode group 2 is overheated in a timely manner, this embodiment provides a first through hole 51 on the side plate 5.

[0033] Specifically, the shape of the first through hole 51 can be strip-shaped, circular, or elliptical.

[0034] Meanwhile, in this embodiment, the insulating film 4 covers the outer wall of the electrode assembly 2 and is disposed within the receiving cavity of the housing 1. The side plate 5 can be disposed between the insulating film 4 and the electrode assembly 2, or between the insulating film 4 and the housing 1. During installation, the electrode assembly 2 is assembled first, and the side plate 5 is installed, then the insulating film 4 is covered on the outside of the electrode assembly 2 and the side plate 5; alternatively, the insulating film 4 is covered on the outside of the electrode assembly 2 after the electrode assembly 2 is assembled. To ensure a tighter coverage of the electrode assembly 2 by the insulating film 4, in this embodiment, the insulating film 4 has a body 41, a first overlap 42, and a second overlap 43. The body 41 can cover two sides along the length direction of the electrode assembly 2 and one side along the width direction of the housing 1, with the three sides connected sequentially. The first overlap 42 and the second overlap 43 are both located outside one side of the housing 1 along its width direction, and are overlapped. This overlap improves the reliability of the insulation film 4 covering the electrode assembly 2, preventing it from detaching. Furthermore, both the first overlap 42 and the second overlap 43 have notches 421. When the first overlap 42 and the second overlap 43 overlap, the two notches 421 correspond to each other and are corresponding to the explosion-proof valve 3. The exhaust channel formed by the notch 421 and the first through hole 51 ensures that there is no obstruction between the electrode assembly 2 and the explosion-proof valve 3. After the insulation film 4 and the side plate 5 soften due to heat deformation, the insulation film 4 adheres to the surface of the explosion-proof valve 3. The clearance space formed by the notch 421 and the first through hole 51 ensures that neither the insulation film 4 nor the side plate obstructs the exhaust channel, thereby improving the stability of cell exhaust.

[0035] Since the explosion-proof valve 3 is located on the side of the housing 1 in the width direction, in order to ensure the support strength of the explosion-proof valve 3, in this embodiment, a side plate 5 is provided between the insulating film 4 and the electrode group 2 or between the insulating film 4 and the housing 1 in the area corresponding to the explosion-proof valve 3. The side plate 5 can maintain the overall square structure of the battery cell and can also transmit the pressure generated by the expansion of the electrode group 2 to the housing 1 relatively evenly.

[0036] Specifically, the shape of the notch 421 can be strip-shaped, elliptical, polygonal, or correspond to the shape of the projection of the pressure relief valve onto the housing 1.

[0037] In one example, such as Figure 1 As shown, the battery cell housing 1 has an opening. One end of the housing 1 is connected to the cover plate 6 via an end plate 7, and the other end is connected to the cover plate 6 via an end plate 7. The electrode tabs of the electrode group 2 are electrically connected to the electrode posts on the cover plate 6 via connecting pieces 8. The explosion-proof valve 3 is located on the side of the housing 1 in the width direction. The housing 1 has through holes for installing the explosion-proof valve 3, and a protective film 9 is attached to the outside of the explosion-proof valve 3.

[0038] The battery cell provided by this utility model can mechanically support the electrode group 2 by setting a side plate 5 between the electrode group 2 and the insulating film 4 or between the insulating film 4 and the shell 1. The side plate 5 is provided with a first through hole 51 corresponding to the explosion-proof valve 3. At the same time, the insulating film 4 is provided with a body 41, a first overlap 42 and a second overlap 43. Notches 421 are provided on the first overlap 42 and the second overlap 43. After the first overlap 42 and the second overlap 43 overlap, the two notches 421 coincide and communicate with the first through hole 51 to form an exhaust channel. After the insulating film 4 and the side plate 5 are heated and softened, the high temperature gas can be discharged from the containment cavity through the explosion-proof valve 3 from the first through hole 51 and the notch 421. This avoids the insulating film 4 and the side plate 5 from being blocked by deformation, improves the stability of the exhaust inside the battery cell, and enhances the safety performance of the battery cell.

[0039] like Figure 3 As shown, the area of ​​the notch 421 in this embodiment is larger than the exhaust area of ​​the explosion-proof valve 3.

[0040] Understandably, in order to ensure the smooth exhaust of high-temperature gas through the notch 421, the area of ​​the notch 421 in this embodiment is larger than the exhaust area of ​​the explosion-proof valve 3, so that the high-temperature gas passing through the notch 421 will not be blocked by the insulating film 4, and can smoothly enter the explosion-proof valve 3 and exit the battery cell housing 1.

[0041] Similarly, the area of ​​the first through hole 51 in this embodiment is also larger than the exhaust area of ​​the explosion-proof valve 3. After the side plate 5 is deformed by heat, the first through hole 51 can still serve as part of the exhaust channel, thus avoiding the side plate 5 from blocking the high-temperature exhaust.

[0042] like Figure 3 As shown, the notch 421 in this embodiment has a first side 4211 and a second side 4212. The first side 4211 extends along the length direction of the housing 1, and the second side 4212 extends along the width direction of the housing 1.

[0043] It is understandable that, since the explosion-proof valve 3 in this embodiment is strip-shaped, the notch 421 in this embodiment is also strip-shaped to match the shape of the explosion-proof valve 3.

[0044] Specifically, the notch 421 has a first side 4211 and a second side 4212. The first side 4211 extends along the length direction of the housing 1 and is corresponding to the long side of the explosion-proof valve 3. The second side 4212 extends along the width direction of the housing 1 and is corresponding to the short side of the explosion-proof valve 3.

[0045] In this embodiment, by providing a first side 4211 and a second side 4212 in the notch 421, the shape of the notch 421 can be adapted to the shape of the explosion-proof valve 3, thus better fitting the exhaust channel of the explosion-proof valve 3.

[0046] like Figure 3 As shown, the thickness of the insulating film 4 in this embodiment is s, and s satisfies: 0.08mm≤s≤0.5mm.

[0047] Understandably, the insulating film 4 can cover the outer walls of the electrode assembly 2 and the side plate 5, and meet certain covering strength requirements. Specifically, the thickness of the insulating film 4 can be 0.08 mm, 0.29 mm, or 0.5 mm.

[0048] Optionally, the insulating film 4 can be made of plastic insulating materials such as PP or PE.

[0049] like Figure 4 As shown, the side plate 5 in this embodiment also includes a second through hole 52.

[0050] The second through hole 52 is located beside the first through hole 51. Both the first through hole 51 and the second through hole 52 extend along the length of the housing 1 and are connected.

[0051] Understandably, in order to enhance the exhaust effect of the explosion-proof valve 3, this embodiment provides a second through hole 52 on the side of the first through hole 51, and provides a strip hole between the first through hole 51 and the second through hole 52. The strip hole is used to connect the first through hole 51 and the second through hole 52, so that high-temperature gas can pass through the second through hole 52 and the strip hole, enter the first through hole 51, and be discharged into the explosion-proof valve 3.

[0052] like Figure 4 As shown, the side plate 5 in this embodiment also includes a third through hole 53.

[0053] Along the length of the housing 1, a third through hole 53 is provided at the end of the side plate 5; wherein the area of ​​the third through hole 53 is smaller than the area of ​​the second through hole 52.

[0054] Understandably, since the diameter of the second through hole 52 is comparable to that of the first through hole 51, the second through hole 52 does not extend to both ends of the side plate 5 to ensure the supporting strength of the side plate 5. In this embodiment, multiple third through holes 53 are provided at both ends of the side plate 5. The area of ​​the third through hole 53 is smaller than that of the second through hole 52, which ensures the strength of the end of the side plate 5, and allows high-temperature exhaust gas to enter the exhaust channel through the third through hole 53, thus achieving compatibility between the strength and exhaust performance of the side plate 5.

[0055] Optionally, in this embodiment, the thickness of the side plate 5 is t, where t satisfies: 0.15mm ≤ t ≤ 1.5mm. Specifically, the thickness of the side plate 5 can be 0.15mm, 0.825mm, or 1.5mm.

[0056] like Figure 3 As shown, in this embodiment, along the length direction of the housing 1, the insulating film 4 has creases 44 to divide the body 41 into a first part 411, a second part 412 and a third part 413, and to separate the first overlap 42 and the second overlap 43 from the body 41.

[0057] The first overlap 42, the first part 411, the second part 412, the third part 413, and the second overlap 43 are connected in sequence.

[0058] Understandably, in order to optimize the covering effect of the insulating film 4, this embodiment provides creases 44 on the insulating film 4. The creases 44 divide the body 41 into a first part 411, a second part 412, and a third part 413. The first part 411 corresponds to the side of the housing 1 in the width direction, and the second part 412 and the third part 413 correspond to the two sides of the housing 1 in the length direction. Creases 44 are also provided between the first overlap 42 and the first part 411, and between the second overlap 43 and the third adhesive part, so that the insulating film 4 can be quickly bent along the creases 44 during the process of covering the electrode assembly 2.

[0059] Specifically, the depth of crease 44 can be 1 / 3 to 2 / 3 of the thickness of side panel 5. For example, the depth of crease 44 can be 1 / 3, 1 / 2, or 2 / 3 of the thickness of side panel 5.

[0060] like Figure 3 and Figure 4 As shown, the insulating film 4 in this embodiment also includes a first positioning hole 45.

[0061] The first positioning hole 45 is provided on the first overlap 42 and the second overlap 43; the side plate 5 has a second positioning hole 54, which is disposed opposite to the first positioning hole 45.

[0062] Understandably, in order to ensure the correct relative position of the insulating film 4 and the side plate 5, this embodiment provides a first positioning hole 45 on the insulating film 4 and a second positioning hole 54 on the side plate 5. When assembling the battery cell, fixing the positions of the first positioning hole 45 and the second positioning hole 54 can achieve the positioning of the insulating film 4 and the side plate 5. There is no need to repeatedly adjust the relative position of the notch 421 and the first through hole 51, which conveniently realizes the installation of the insulating film 4 and the side plate 5 and improves the assembly efficiency of the battery cell.

[0063] Specifically, a first positioning hole 45 can be provided on the first overlap 42 and the second overlap 43, and a second positioning hole 54 can also be provided. The two first positioning holes 45 on the first overlap 42 and the second overlap 43 overlap and are positioned with the second positioning hole 54. Multiple second positioning holes 54 can also be provided, with multiple first positioning holes 45 and multiple second positioning holes 54 being provided in a one-to-one correspondence.

[0064] In one example, four first positioning holes 45 are provided in this embodiment, and two second positioning holes 54 are provided in each embodiment. Two of the four first positioning holes 45 are located at both ends of the first overlap 42, and the remaining two of the four first positioning holes 45 are located at both ends of the second overlap 43. The two second positioning holes 54 are located at corresponding positions on the side plate 5 to ensure that the insulating film 4 and the side plate 5 can be accurately positioned along both the length and width directions of the housing 1.

[0065] In this embodiment, the insulating film 4 and the side plate 5 are thermally fused together to form an integral structure.

[0066] Understandably, when the insulating film 4 is heat-fused to the cover plate 6, it is heat-fused to the side plate 5 to form an integral structure, and the relative position of the first through hole 51 and the notch 421 is fixed, which is more conducive to the stability of the exhaust channel.

[0067] Secondly, this embodiment provides a battery pack including multiple cells as described above.

[0068] Specifically, since the battery pack includes battery cells, and the specific structure of the battery cells refers to the above embodiments, the battery pack shown in this embodiment includes all the technical solutions of the above embodiments. Therefore, it has at least all the beneficial effects obtained by all the technical solutions of the above embodiments, which will not be described in detail here.

[0069] Understandably, a battery pack includes a housing, and multiple battery cells are housed within the housing to form the battery pack.

[0070] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A battery cell, characterized in that, include: The shell has a receiving cavity; The pole assembly is disposed within the receiving cavity; An explosion-proof valve is located on one side of the housing in the width direction; An insulating film is provided to cover the electrode assembly. The insulating film includes a body, a first overlap and a second overlap. The first overlap and the second overlap are respectively disposed on both sides of the body and overlapped. Both the first overlap and the second overlap are provided with notches, and the two notches are disposed opposite to each other. A side plate is disposed between the electrode group and the insulating film or between the insulating film and the housing, and is located on one side of the housing in the width direction, and is correspondingly disposed to the explosion-proof valve. The side plate is provided with a first through hole, and the first through hole and the notch form an exhaust channel.

2. The battery cell according to claim 1, characterized in that, The area of ​​the notch is larger than the exhaust area of ​​the explosion-proof valve.

3. The battery cell according to claim 2, characterized in that, The notch has a first side and a second side, the first side extending along the length direction of the housing and the second side extending along the width direction of the housing.

4. The battery cell according to claim 1, characterized in that, The thickness of the insulating film is s, and s satisfies: 0.08mm≤s≤0.5mm.

5. The battery cell according to claim 1, characterized in that, The side plate also includes: a second through hole; The second through hole is located beside the first through hole. Both the first through hole and the second through hole extend along the length of the housing and are connected.

6. The battery cell according to claim 5, characterized in that, The side plate also includes: a third through hole; Along the length of the housing, the third through hole is located at the end of the side plate; The area of ​​the third through hole is smaller than the area of ​​the second through hole.

7. The battery cell according to claim 1, characterized in that, Along the length of the housing, creases are formed on the insulating film to divide the body into a first part, a second part, and a third part, and to separate the first overlap and the second overlap from the body; The first overlap, the first part, the second part, the third part, and the second overlap are connected in sequence.

8. The battery cell according to claim 1, characterized in that, The insulating film further includes: a first positioning hole; The first positioning hole is provided on the first overlap and the second overlap; The side plate has a second positioning hole, which is positioned opposite to the first positioning hole.

9. The battery cell according to claim 1, characterized in that, The insulating film and the side plate are thermally fused together to form a single structure.

10. A battery pack, characterized in that, It includes multiple battery cells as described in any one of claims 1 to 9.

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