Insulating film, battery cell, and electric device

Abstract

The application relates to the technical field of blade battery, and provides an insulating film, a battery cell and an electric device. The insulating film comprises an insulating film body; the insulating film body has a first wrapping part and a second wrapping part, the first wrapping part is connected with the second wrapping part on both sides along a first direction, the first wrapping part is used for wrapping a side part of a pole group, the two second wrapping parts are used for wrapping two end parts of the pole group respectively, a via hole is arranged on each second wrapping part for passing through a tab in the pole group, and a plurality of through holes are arranged corresponding to liquid injection holes or explosion-proof valves on a battery cell cover plate. The insulating film can better wrap the pole group, can meet the functions of exhaust, liquid injection and air permeation, can avoid damage caused by a hot melting point compared with a traditional insulating film structure, and can improve the stability of the insulating film wrapping.

Description

Technical Field

[0001] This application relates to the field of blade battery technology, and in particular to an insulating film. This application also relates to a battery cell having the aforementioned insulating film, and an electrical device having the aforementioned battery cell. Background Technology

[0002] Lithium-ion batteries are widely used in various fields such as transportation power supply, power storage, new energy storage power supply, aerospace and military industries due to their advantages such as large capacity, high operating voltage, strong charge retention capability, and long cycle life. After the assembly of the electrode assembly and the final welding of the tabs are completed, an insulating film is usually wrapped around the outside of the electrode assembly to separate the electrode assembly from the casing, thus providing insulation.

[0003] For blade battery structures, an insulating film is typically used to wrap the battery electrode assembly for insulation protection. Traditional insulating films usually only wrap the sides of the battery electrode assembly, leaving the end face where the tabs are located unwrapped. Furthermore, the insulating film near the tab end face is fixed to a plastic structure on the top cover or other plastic structures by heat fusion. This method of structure is unstable, and the heat fusion point is easily damaged, leading to the failure of the insulating film wrapping. Utility Model Content

[0004] In view of this, the present application aims to provide an insulating film that can avoid damage to the insulating film caused by the heat melting point and improve the stability of the insulating film wrapping.

[0005] To achieve the above objectives, the technical solution of this application is implemented as follows: An insulating film, comprising an insulating film body; The insulating film body has a first wrapping portion and a second wrapping portion. The first wrapping portion is connected to the second wrapping portion on both sides along the first direction. The first wrapping portion is used to wrap the side of the electrode group. The two second wrapping portions are used to wrap the two ends of the electrode group respectively. Each second wrapping portion is provided with a through hole for the electrode tab in the electrode group to pass through, as well as multiple through holes. The multiple through holes are provided with liquid injection holes or explosion-proof valves on the cell cover plate.

[0006] Furthermore, the first package portion includes a first narrow-face package portion, a large-face package portion, and a second narrow-face package portion; the first narrow-face package portion is connected to the large-face package portion on both sides along the second direction, and each of the large-face package portions is connected to the second narrow-face package portion on the side of the large-face package portion away from the first narrow-face package portion in the second direction.

[0007] Furthermore, the dimension L1 of the first narrow-faceted wrapping portion in the second direction is consistent with the thickness of the pole group.

[0008] Furthermore, the ratio between the dimension L2 of the two second narrow facets in the second direction and the thickness of the pole group is between 0.5 and 1.

[0009] Furthermore, the two second package portions are respectively connected to both sides of one of the large package portions along the first direction; or, the two second package portions are respectively connected to opposite sides of the two large package portions.

[0010] Furthermore, pre-folding grooves are provided between the first narrow-face wrapping portion and the two adjacent large-face wrapping portions, as well as between each large-face wrapping portion and the corresponding second narrow-face wrapping portion, and each pre-folding groove extends along the first direction.

[0011] Furthermore, the ratio between the dimension of the pre-folded indentation groove in the thickness direction of the insulating film body and the thickness of the insulating film body is between 1 / 3 and 1 / 2.

[0012] Furthermore, the via is an elongated hole, the length D1 of the via is 3mm-10mm longer than the length of the tab, and / or the width D2 of the via is 1mm-6mm longer than the thickness of the tab.

[0013] Compared with related technologies, this application has the following advantages: (1) The insulating film described in this application wraps the side of the electrode group and the two ends of the electrode group by setting the first wrapping part and the second wrapping part respectively, and the second wrapping part is provided with through holes for the electrode tabs to pass through, so that the electrode tabs can extend and connect to the electrode post. Multiple through holes are provided to facilitate the electrode group to breathe, to facilitate the wetting of electrolyte and to facilitate the exhaust of thermal runaway, thereby satisfying the functions of exhaust, liquid injection and breathability. Compared with the insulating film structure in the prior art, it can avoid the damage caused by the hot melting point and improve the stability of the insulating film wrapping.

[0014] (2) By setting the first wrapping part to include a first narrow wrapping part, a large wrapping part and a second narrow wrapping part, the first narrow wrapping part wraps one narrow surface of the pole group, the two large wrapping parts wrap the two opposite large surfaces of the pole group, and the second narrow wrapping parts on both sides are stacked on the other narrow surface of the pole group in sequence, so that the two narrow surfaces and two large surfaces of the pole group can be wrapped well.

[0015] (3) The size of the first narrow face wrapping part in the second direction is consistent with the thickness of the electrode group. This can better match the thickness of the electrode group and prevent the electrode group from being wrapped too tightly due to the size being too small or wrinkles from being too large.

[0016] (4) Limiting the size of the second narrow face wrapping part in the second direction allows the insulating film to cover the electrode group so that the docking position can at least leave a certain overlap, thereby further improving the wrapping effect on the side of the electrode group.

[0017] (5) The position of the two second wrapping parts is limited so that the end face of the electrode group where the electrode tab is located can be well wrapped.

[0018] (6) By setting pre-folding and indentation grooves, the insulating film can be bent quickly and accurately to wrap the electrode assembly, thereby improving the efficiency of the insulating film wrapping the electrode assembly.

[0019] (7) Limiting the dimensions of the pre-folding indentation groove in the thickness direction of the insulating film body can prevent electrode powder from falling through the insulating film and contacting the inner wall of the battery cell housing, causing a short circuit.

[0020] (8) By limiting the length and width of the through hole, sufficient assembly clearance can be ensured, which facilitates the smooth passage of the electrode tab through the through hole.

[0021] Another objective of this application is to provide a battery cell in which the electrode group is covered by an insulating film as described above, and the two second encapsulated portions are respectively fixed inside the battery cell by a lower plastic part on the positive electrode side and a lower plastic part on the negative electrode side.

[0022] The battery cell described in this application, by employing the aforementioned insulating film, effectively wraps the electrode assembly, fulfilling the functions of venting, liquid injection, and air permeability. It also avoids damage to the insulating film caused by thermal melting points, improving the stability of the insulating film wrapping, thereby enhancing the quality and service life of the battery cell.

[0023] Another object of this application is to provide an electrical device having a battery cell as described above.

[0024] The electrical equipment described in this application, by employing the aforementioned battery cell and utilizing the insulating film to wrap the sides and ends of the electrode assembly, not only satisfies the functions of venting, liquid injection, and air permeability, but also avoids damage to the insulating film caused by the hot melting point, improves the stability of the insulating film wrapping, and helps to improve the quality and service life of the battery cell, thereby improving the quality and service life of the electrical equipment. Attached Figure Description

[0025] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a schematic diagram of the first structure of the insulating film described in the embodiments of this application; Figure 2This is a schematic diagram of a second structure of the insulating film described in an embodiment of this application; Figure 3 This is a schematic diagram of a third structure of the insulating film described in the embodiments of this application; Figure 4 This is an enlarged view of the second package portion described in the embodiments of this application; Figure 5 This is a schematic diagram of the pole group structure described in the embodiments of this application; Figure 6 This is a partial structural diagram of the insulating film covering the electrode assembly as described in an embodiment of this application; Figure 7 This is a schematic diagram of the battery cell structure described in the embodiments of this application; Figure 8 This is a cross-sectional view of the battery cell described in the embodiments of this application; Explanation of reference numerals in the attached figures: 1. Insulating film body; 11. First wrapping part; 12. Second wrapping part; 110. Pre-folded crease groove; 111. First narrow face wrapping section; 112. First large face wrapping section; 113. Second large face wrapping section; 114. Second narrow face wrapping section; 121. Through hole; 122. Through hole; 2. Pole group; 20. Pole tab; 21. First end; 22. Second end; 23. Large facet; 24. Narrow facet; 100. Cell casing; 200. Positive side cell cover; 300. Negative side cell cover; 2001. Positive terminal post; 2002. Explosion-proof valve; 2003. Positive side lower plastic part; 3001. Negative terminal post; 3002. Negative side lower plastic part. Detailed Implementation

[0026] To make the technical solution and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0027] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0028] Furthermore, it should be noted that in the description of this application, if terms such as "upper," "lower," "inner," or "outer" appear, indicating orientation or positional relationship, these are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this application 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, and therefore should not be construed as a limitation on this application. In addition, if terms such as "first" or "second" appear, they are also used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0029] Furthermore, in the description of this application, unless otherwise expressly defined, the terms "installation," "connection," "joining," and "connector" 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; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application in light of the specific circumstances.

[0030] In this application, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0031] The present application will now be described in detail through exemplary embodiments. However, it should be understood that, without further description, elements, structures, and features in one embodiment may be advantageously incorporated into other embodiments.

[0032] An embodiment of the first aspect of this application provides an insulating film that can prevent damage to the insulating film caused by heat melting points and improve the stability of the insulating film wrapping.

[0033] In related technologies, after the assembly of the electrode assembly and the final welding of the tabs are completed, an insulating film is usually wrapped around the outside of the electrode assembly to separate the electrode assembly from the casing, thus providing insulation.

[0034] For blade battery structures, an insulating film is typically used to wrap the battery electrode assembly for insulation protection. Traditional insulating films usually only wrap the sides of the battery electrode assembly, leaving the end face where the tabs are located unwrapped. Furthermore, the insulating film near the tab end face is fixed to a plastic structure on the top cover or other plastic structures by heat fusion. This method of structure is unstable, and the heat fusion point is easily damaged, leading to the failure of the insulating film wrapping.

[0035] In view of this, in order to overcome the shortcomings of related technologies, the insulating film in this embodiment incorporates... Figures 1 to 4 As shown, the overall design includes an insulating film body 1. The insulating film body 1 has a first wrapping portion 11 and a second wrapping portion 12.

[0036] The first wrapping portion 11 is connected to two second wrapping portions 12 on both sides along the first direction, and the first wrapping portion 11 is used to wrap the side of the electrode group 2. The two second wrapping portions 12 are used to wrap the two ends of the electrode group 2 respectively, and each second wrapping portion 12 is provided with a through hole 121 for the electrode tab 20 of the electrode group 2 to pass through, as well as multiple through holes 122, which are provided corresponding to the liquid injection hole or explosion-proof valve 2002 on the cell cover plate.

[0037] Therefore, the first wrapping portion 11 and the second wrapping portion 12 respectively wrap the sides and two ends of the electrode assembly 2, and the second wrapping portion 12 is provided with through holes 122 for the tabs 20 to pass through, so that the tabs 20 at both ends can extend out and be electrically connected to the positive electrode post 2001 and the negative electrode post 3001 respectively. Multiple through holes 122 are provided to facilitate ventilation of the electrode assembly 2, to facilitate electrolyte wetting, and to facilitate thermal runaway venting, thus satisfying the functions of venting, electrolyte injection, and ventilation. Compared with the insulating film structure in the prior art, this avoids damage caused by thermal melting points and improves the stability of the insulating film wrapping.

[0038] Based on the above overview, specifically, the structure of pole group 2 will first be described. In this embodiment, refer to... Figure 5 As shown, electrode group 2 is rectangular in shape, and the two tabs 20 (positive tab 20 and negative tab 20) in electrode group 2 are respectively arranged at opposite ends of electrode group 2, that is... Figure 5 The first end 21 and the second end 22. The ends where the electrode tabs 20 are located form the side portion of the electrode group 2, that is... Figure 5 The two opposing large faces 23 and the two opposing narrow faces 24.

[0039] In this embodiment, the first wrapping portion 11 of the insulating film body 1 is used to wrap the side of the electrode assembly 2, that is, to wrap the two opposing large surfaces 23 and the two opposing narrow surfaces 24 in the electrode assembly 2. The insulating film body 1 has two second wrapping portions 12, which are respectively connected to both sides of the first wrapping portion 11 along the first direction, and are respectively used to wrap the ends of the electrode assembly 2 where the tabs 20 are located. Each second wrapping portion 12 is provided with a through hole 121 for the tabs 20 to pass through, and a plurality of through holes 122.

[0040] Combination Figures 5 to 8 As shown, the electrode assembly 2 is housed within the cell housing 100, which has openings at both ends, each sealed by a cell cover plate. As an example, one end of the cell cover plate has a liquid injection hole, and the other end has an explosion-proof valve 2002. In this case, multiple through holes 122 on the two second enclosure portions 12 are respectively positioned corresponding to the liquid injection hole and the explosion-proof valve 2002.

[0041] Of course, it is understandable that, for example, when the injection port and the explosion-proof valve 2002 are arranged on the same cell cover plate, some of the through holes 122 on the second wrapping part 12 can correspond to the position of the injection port, and some of the through holes 122 can correspond to the position of the explosion-proof valve 2002. This is also feasible. In addition, it is worth noting that the insulating film in this embodiment can be, for example, a Mylar insulating film made of polyester polymer material.

[0042] Combination Figures 1 to 3 As shown, in some exemplary embodiments, for example, the first wrapping portion 11 includes a first narrow wrapping portion 111, a large wrapping portion, and a second narrow wrapping portion 114. The first narrow wrapping portion 111 is connected to the large wrapping portion on both sides along the second direction, and the large wrapping portion is connected to the second narrow wrapping portion 114 on the side of the large wrapping portion away from the first narrow wrapping portion 111 in the second direction.

[0043] At this time, by setting the first wrapping part 11 to include a first narrow wrapping part 111, a large wrapping part and a second narrow wrapping part 114, the first narrow wrapping part 111 wraps one narrow surface of the pole group 2, the two large wrapping parts wrap the two opposite large surfaces of the pole group 2, and the second narrow wrapping parts 114 on both sides are stacked on the other narrow surface of the pole group 2 in sequence. In this way, the two narrow surfaces and two large surfaces of the pole group 2 can be wrapped well.

[0044] Continue to combine Figures 1 to 3As shown, in some exemplary embodiments, for example, the dimension L1 of the first narrow-face wrapping portion 111 in the second direction is consistent with the thickness of the electrode assembly 2. This allows for a better match with the thickness of the electrode assembly 2, preventing the electrode assembly 2 from being wrapped too tightly due to being too small or wrinkled due to being too large.

[0045] Still combined Figures 1 to 3 As shown, in some exemplary embodiments, for example, the ratio between the dimension L2 of the two second narrow facets 114 in the second direction and the thickness of the pole group 2 is between 0.5 and 1. In specific implementations, this ratio may be set to, for example, 0.5, 0.6, 0.7, 0.8, 0.9, or 1, etc.

[0046] Here, by limiting the size of the second narrow-face wrapping portion 114 in the second direction, when the insulating film wraps the electrode group 2, at least a certain overlap can be reserved at the docking position, thereby further improving the wrapping effect on the side of the electrode group 2.

[0047] Continue to combine Figures 1 to 3 As shown, in some exemplary embodiments, for example, two second wrapping portions 12 are respectively connected to both sides of one of the large-surface wrapping portions along the first direction. Alternatively, the two second wrapping portions 12 are respectively connected to opposite sides of the two large-surface wrapping portions. By defining the positions of the two second wrapping portions 12, the end face where the electrode tab 20 of the electrode group 2 is located can be well wrapped.

[0048] Specifically, for ease of description, the two large wrapping parts are defined here as the first large wrapping part 112 and the second large wrapping part 113, respectively. The first large wrapping part 112 and the second large wrapping part 113 are respectively connected to the first narrow wrapping part 111 on both sides in the second direction. The two second wrapping parts 12 can be as follows: Figure 1 As shown, the second wrapping portions 12 are connected to the first large-area wrapping portion 112 and the second large-area wrapping portion 113 respectively, and the two second wrapping portions 12 are arranged opposite to each other. Alternatively, as shown... Figure 2 As shown, the two second wrapping portions 12 are respectively connected to the first large-surface wrapping portion 112 on both sides in the first direction. Alternatively, as... Figure 3 As shown, the two second wrapping portions 12 are respectively connected to the second large surface wrapping portion 113 on both sides in the second direction.

[0049] Combination Figures 1 to 3As shown, in some exemplary embodiments, pre-folding and indentation grooves 110 are provided, for example, between the first narrow-face wrapping portion 111 and the two adjacent large-face wrapping portions, and between the large-face wrapping portions and the corresponding second narrow-face wrapping portions 114. Each pre-folding and indentation groove 110 extends along a first direction. In this case, by providing the pre-folding and indentation grooves 110, it is convenient to quickly and accurately bend the insulating film to wrap the electrode assembly 2, thereby improving the efficiency of the insulating film wrapping the electrode assembly 2.

[0050] Continue to combine Figures 1 to 3 As shown, in some exemplary embodiments, the ratio between the dimension of the pre-folded indentation groove 110 in the thickness direction of the insulating film body 1 and the thickness of the insulating film body 1 is between 1 / 3 and 1 / 2. In specific implementations, this ratio can be set to, for example, 1 / 3, 3 / 8, 2 / 5, 3 / 7, or 1 / 2.

[0051] Here, by limiting the size of the pre-folding indentation groove 110 in the thickness direction of the insulating film body 1, it is possible to prevent the powder of the electrode sheet in the electrode group 2 from falling through the insulating film and contacting the inner wall of the cell housing 100, causing a short circuit.

[0052] Reference Figure 4 As shown, in some exemplary embodiments, the through hole 121 formed on the second package portion 12 is, for example, an elongated hole. The length of the through hole 121 is 3mm-10mm greater than the length D1 of the tab 20, and the width D2 of the through hole 121 is 1mm-6mm greater than the thickness of the tab 20. By limiting the length and width of the through hole 121, sufficient assembly clearance can be ensured to facilitate the tab 20 passing smoothly through the through hole 121.

[0053] In practical implementation, the length D1 of the through hole 121 can be 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, or 10mm longer than the length of the tab 20. The width D2 of the through hole 121 can be 1mm, 2mm, 3mm, 4mm, 5mm, or 6mm longer than the thickness of the tab 20. This allows the tabs 20 at both ends of the electrode assembly 2 to pass smoothly through the through hole 121.

[0054] It is worth noting that, regarding the insulating film of this embodiment, based on the above exemplary embodiments, in specific implementation, as a preferred embodiment, it is still made by... Figures 1 to 4As shown, it may include, for example, an insulating film body 1 having a first wrapping portion 11 and a second wrapping portion 12. The first wrapping portion 11 has a second wrapping portion 12 connected to both sides along a first direction, and the first wrapping portion 11 is used to wrap the sides of the electrode assembly 2. The two second wrapping portions 12 are used to wrap the two ends of the electrode assembly 2 respectively, and each second wrapping portion 12 is provided with a through hole 121 for the electrode tab 20 of the electrode assembly 2 to pass through, and a plurality of through holes 122, the plurality of through holes 122 corresponding to the liquid injection hole or explosion-proof valve 2002 on the cell cover plate.

[0055] The first wrapping portion 11 includes a first narrow wrapping portion 111, a large wrapping portion and a second narrow wrapping portion 114. The first narrow wrapping portion 111 is connected to the large wrapping portion on both sides along the second direction, and the large wrapping portion is connected to the second narrow wrapping portion 114 on the side of the large wrapping portion away from the first narrow wrapping portion 111 in the second direction.

[0056] The first narrow-faceted wrapping portion 111 has a dimension L1 in the second direction that is the same as the thickness of the pole group 2. The ratio between the dimension L2 of the two second narrow-faceted wrapping portions 114 in the second direction and the thickness of the pole group 2 is between 0.5 and 1.

[0057] The two second wrapping portions 12 are respectively connected to both sides of one of the large wrapping portions along the first direction; or, the two second wrapping portions 12 are respectively connected to the opposite sides of the two large wrapping portions.

[0058] In this design, pre-folding and indentation grooves 110 are provided between the first narrow-face wrapping portion 111 and the two adjacent large-face wrapping portions, and between the large-face wrapping portions and the corresponding second narrow-face wrapping portions 114. Each pre-folding and indentation groove 110 extends along a first direction. Preferably, the ratio between the dimension of the pre-folding and indentation groove 110 in the thickness direction of the insulating film body 1 and the thickness of the insulating film body 1 is between 1 / 3 and 1 / 2.

[0059] Among them, the via 121 is an elongated hole, the length D1 of the via 121 is 3mm-10mm longer than the length of the tab 20, and the width D2 of the via 121 is 1mm-6mm longer than the thickness of the tab 20.

[0060] In the above preferred embodiments, the specific settings and arrangements of the first wrapping portion 11, the second wrapping portion 12, the positions of the second wrapping portion 12, the pre-folding and crease groove 110, the through hole 121, and the through hole 122, etc., can still be referred to the descriptions in the above exemplary embodiments. Furthermore, in this preferred embodiment, the beneficial effects brought about by the design of the first wrapping portion 11, the second wrapping portion 12, the pre-folding and crease groove 110, the through hole 121, and the through hole 122, etc., can also be referred to the descriptions in the above exemplary embodiments.

[0061] The insulating film of this embodiment adopts the above design. By setting a second wrapping portion 12 to wrap the end of the counter electrode group 2, and setting through holes 121 and multiple through holes 122 on the second wrapping portion 12, it can not only meet the functions of venting, liquid injection and air permeability, but also avoid the damage of the insulating film caused by the hot melting point compared with the insulating film structure in the prior art, and improve the stability of the insulating film wrapping.

[0062] An embodiment of the second aspect of this application provides a battery cell, as shown in reference 6 to... Figure 8 As shown, the electrode group 2 in the battery cell is covered by the aforementioned insulating film, and the two second wrapping parts 12 are fixed inside the battery cell by the positive electrode side lower plastic part 2003 and the negative electrode side lower plastic part, respectively.

[0063] Specifically, refer to Figure 7 and Figure 8 The battery cell mainly comprises a battery cell housing 100, an electrode assembly 2 covered with an insulating film, and battery cell cover plates connected to both ends of the battery cell housing 100. The battery cell cover plates at both ends are the positive electrode side battery cover plate 200 and the negative electrode side battery cover plate 300. The positive electrode side battery cover plate 200 has a positive electrode side lower plastic part 2003, and the negative electrode side battery cover plate 300 has a negative electrode side lower plastic part 3002.

[0064] In practice, the state of electrode group 2 after the insulating film is wrapped is as follows: Figure 6 As shown, after the electrode assembly 2 is wrapped with an insulating film, the seam is further bonded and fixed with insulating tape to improve the fixing effect of the insulating film. The electrode assembly 2 covered with insulating film is installed into the cell housing 100. The positive electrode side cell cover plate 200 and the negative electrode side cell cover plate 300 are connected to both ends of the cell housing 100. At this time, the lower plastic part 2003 on the positive electrode side and the lower plastic part on the negative electrode side press against the insulating film with the tabs 20 at both ends of the electrode assembly 2, so that the insulating film is better fixed on the end face of the electrode assembly 2, and the electrode assembly 2 is also better fixed inside the cell housing 100.

[0065] In this embodiment, the battery cell uses the aforementioned insulating film to better wrap the electrode assembly 2, which can satisfy the functions of venting, liquid injection, and air permeability, and can also avoid damage to the insulating film caused by the hot melting point, thereby improving the stability of the insulating film wrapping and thus improving the quality and service life of the battery cell.

[0066] An embodiment of the third aspect of this application provides an electrical device that includes the aforementioned battery cell.

[0067] The electrical equipment in this embodiment, by using the aforementioned battery cell and wrapping the sides and ends of the electrode group 2 with an insulating film, not only satisfies the functions of venting, liquid injection, and air permeability, but also avoids damage to the insulating film caused by the hot melting point, improves the stability of the insulating film wrapping, and helps to improve the quality and service life of the battery cell, thereby improving the quality and service life of the electrical equipment.

[0068] The above descriptions are merely some embodiments of this application and are not intended to limit this application. The technical features or structures in the foregoing different embodiments can be arbitrarily combined to form other specific technical solutions as needed. For those skilled in the art, this application can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of the claims of this application.

Claims

1. An insulating film, characterized in that: Including the insulating film body; The insulating film body has a first wrapping portion and a second wrapping portion. The first wrapping portion is connected to the second wrapping portion on both sides along the first direction. The first wrapping portion is used to wrap the side of the electrode group. The two second wrapping portions are used to wrap the two ends of the electrode group respectively. Each second wrapping portion is provided with a through hole for the electrode tab in the electrode group to pass through, as well as multiple through holes. The multiple through holes are provided with liquid injection holes or explosion-proof valves on the cell cover plate.

2. The insulating film according to claim 1, characterized in that: The first package portion includes a first narrow-face package portion, a large-face package portion, and a second narrow-face package portion; The first narrow-face wrapping portion is connected to the large-face wrapping portion on both sides along the second direction, and each of the large-face wrapping portions is connected to the second narrow-face wrapping portion on the side of the large-face wrapping portion away from the first narrow-face wrapping portion in the second direction.

3. The insulating film according to claim 2, characterized in that: The dimension L1 of the first narrow-faceted wrapping portion in the second direction is consistent with the thickness of the pole group.

4. The insulating film according to claim 2, characterized in that: The ratio between the dimension L2 of the two second narrow facets in the second direction and the thickness of the pole group is between 0.5 and 1.

5. The insulating film according to claim 2, characterized in that: The two second package portions are respectively connected to both sides of one of the large package portions along the first direction; or, the two second package portions are respectively connected to opposite sides of the two large package portions.

6. The insulating film according to claim 2, characterized in that: A pre-folding groove is provided between the first narrow-face wrapping part and the two adjacent large-face wrapping parts, and between each large-face wrapping part and the corresponding side of the second narrow-face wrapping part. Each pre-folding groove extends along the first direction.

7. The insulating film according to claim 6, characterized in that: The ratio between the dimension of the pre-folded indentation groove in the thickness direction of the insulating film body and the thickness of the insulating film body is between 1 / 3 and 1 / 2.

8. The insulating film according to any one of claims 1 to 7, characterized in that: The via is an elongated hole, and the length D1 of the via is 3mm-10mm longer than the length of the tab, and / or the width D2 of the via is 1mm-6mm longer than the thickness of the tab.

9. A battery cell, characterized in that: The electrode group in the battery cell is covered by the insulating film according to any one of claims 1 to 8, and the two second wrapping parts are respectively fixed inside the battery cell by the lower plastic part on the positive electrode side and the lower plastic part on the negative electrode side.

10. An electrical appliance, characterized in that: The electrical equipment is equipped with the battery cell as described in claim 9.

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