Single battery and battery pack

Abstract

The utility model discloses a single battery and a battery pack, the single battery has a first direction and a second direction which are perpendicular to each other, the single battery comprises a shell, a cover body, a battery cell, an insulating film and a plugging film, and the battery cell is provided with an accommodating cavity; the cover body covers the shell, and the first direction is perpendicular to the cover body; the battery cell is contained in the containing cavity and provided with a top face, a bottom face, a first side face and a second side face, the area of the first side face is larger than that of the second side face, and the second direction is perpendicular to the first side face; a seam is formed between the part, attached to the bottom surface, of the insulating film and the part, attached to the second side surface, of the insulating film; the plugging film comprises a first plugging sub-film and a second plugging sub-film which are of a split structure, and the first plugging sub-film and the second plugging sub-film are distributed in the second direction so as to be matched with each other to plug the joint. Through cooperative use of the first plugging sub-film and the second plugging sub-film which are arranged in a split manner, plugging of the seam is realized, so that falling active substances are not liable to contact with the shell, and the protection effect is effectively improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a single cell and a battery pack. Background Art

[0002] Lithium-ion batteries are now widely used as the main power source for new energy vehicles. In the application process of square lithium-ion batteries, sometimes the bottom of the square aluminum shell lithium-ion battery is corroded and leaked. The reason is that during the long-term use of the battery, the active material falls off from the pole piece, and the fallen active material contacts the bottom of the inner wall of the aluminum shell, forming a corroded electron channel, causing corrosion at the bottom of the aluminum shell, and even perforating the aluminum shell after corrosion, causing the electrolyte to flow out from the hole formed by the corrosion, forming leakage. In the prior art, Mylar film (insulating film) is coated on the side of the battery cell, and glue is applied at the seam of the Mylar film, but the gluing method in the prior art cannot completely block the seam, and the fallen active material still has the risk of contact with the shell, which leads to corrosion of the shell or even leakage.

[0003] Therefore, it is necessary to improve the existing technology. Utility Model Content

[0004] The utility model aims to solve at least one of the technical problems existing in the prior art and provides a single cell and a battery pack.

[0005] According to one aspect of the present application, the present application provides a single cell battery having a first direction and a second direction perpendicular to each other, the single cell battery comprising a shell, a cover, a battery cell, an insulating film and a blocking film, the battery cell having a receiving cavity; the cover body is covered on the shell to close the receiving cavity, the first direction is perpendicular to the cover body; the battery cell is received in the receiving cavity, the battery cell has a top surface and a bottom surface opposite to each other in the first direction, and a first side surface and a second side surface extending along the first direction and connected between the outer edges of the bottom surface and the top surface, the top surface is arranged between the bottom surface and the cover body, The area of ​​the first side surface is greater than that of the second side surface, and the second direction is perpendicular to the first side surface; the insulating film is at least folded and attached to the bottom surface, the first side surface and the second side surface, and a seam is provided between a portion of the insulating film attached to the bottom surface and a portion of the insulating film attached to the second side surface; the sealing film comprises a first sealing sub-membrane and a second sealing sub-membrane which are separate structures from each other, the first sealing sub-membrane and the second sealing sub-membrane are both attached to the insulating film, and the first sealing sub-membrane and the second sealing sub-membrane are distributed along the second direction to cooperate in sealing the seam.

[0006] Furthermore, the second blocking sub-film is partially attached to the surface of the first blocking sub-film that is opposite to the insulating film, and partially extends to be attached to the surface of the insulating film that is opposite to the battery cell.

[0007] Optionally, the portion of the insulating film attached to the same second side has an overlapping area, the portion where the first blocking sub-membrane overlaps the second blocking sub-membrane is the overlapping area, and the orthographic projection of the overlapping area on the second side and the orthographic projection of the overlapping area on the second side are spaced apart from each other in the second direction.

[0008] Further, in the second direction, the second blocking sub-membrane is arranged on both sides of the first blocking sub-membrane, the first blocking sub-membrane is partially attached to the surface of the insulating film facing away from the bottom surface, and the remaining portion is attached to the surface of the insulating film facing away from the second side surface, the second blocking sub-membrane is partially attached to the surface of the insulating film facing away from the second side surface, partially attached to the surface of the insulating film facing away from the first side surface, and the remaining portion is attached to the surface of the insulating film facing away from the bottom surface.

[0009] Furthermore, the single cell battery also includes a bottom support plate, the bottom support plate has a first positioning hole, the portion of the insulating film attached to the bottom surface has a second positioning hole, and the bottom support plate is positioned on the side of the insulating film away from the bottom surface through the cooperation of the first positioning hole and the second positioning hole; the first sealing sub-membrane extends to the portion attached to the bottom surface to block the first positioning hole and the second positioning hole.

[0010] Further, in the second direction, the distance between the portions of the insulating film attached to the first side surface is L1 mm, and the size of the first blocking sub-film is L2 mm, satisfying: 2 / 3≤L2 / L1≤3 / 4.

[0011] Furthermore, the single battery further includes a third direction, and the third direction is perpendicular to the second side surface;

[0012] In the first direction, the dimension of the first blocking sub-film attached to the side of the insulating film facing away from the second side surface is H1mm;

[0013] In the third direction, a dimension of the first blocking sub-film attached to the insulating film on the side facing away from the bottom surface is H4 mm, satisfying: 0≤H4-H1≤5.

[0014] Further, in the second direction, a distance between an end of the first blocking sub-film and the insulating film close to the end and attached to the first side surface is d2 mm, satisfying: 3≤d2≤10.

[0015] Furthermore, the single cell further includes a third direction, the third direction being perpendicular to the second side surface; in the second direction, the dimension of the second blocking sub-film attached to the insulating film on the side facing away from the second side surface is L3 mm; in the first direction, the dimension of the second blocking sub-film attached to the insulating film on the side facing away from the second side surface is H2 mm; in the third direction, the dimension of the second blocking sub-film attached to the insulating film on the side facing away from the first side surface is L3 mm, satisfying:

[0016] L3=H2, and 2≤L3-d2≤5.

[0017] Furthermore, the shell has a bottom wall and a side wall inside, the side wall is arranged around the outer edge of the bottom wall, and the bottom wall and the side wall are coated with an isolation layer.

[0018] Furthermore, the connection between the side wall and the bottom wall is rounded, the value of the rounded corner is Rmm, and the size of the isolation layer coated on the side wall in the first direction is H3mm, satisfying: 3≤H3-R≤6.

[0019] Further, in the first direction, a distance from an outer edge of a portion of the insulating film attached to the second side surface close to the bottom surface to the bottom surface is d1 mm, satisfying: 0.5≤d1≤1.5.

[0020] According to another aspect of the present application, a battery pack is provided, comprising any of the above-mentioned single cells.

[0021] The beneficial effects of the present application are as follows: the present application achieves the sealing of the joint by using the first sealing sub-membrane and the second sealing sub-membrane which are separately arranged. After the joint is sealed, the detached active material is not easy to contact the shell, thereby effectively preventing the shell from corroding and the leakage of the single cell caused by corrosion. In addition, the first sealing sub-membrane and the second sealing sub-membrane are separately arranged to facilitate the pasting operation of the two, ensure the pasting effect, effectively improve the protective effect, and at the same time reduce the use of the sealing film and reduce the production cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The technical solution and other beneficial effects of the present application will be made apparent by describing in detail the specific implementation methods of the present application in conjunction with the accompanying drawings.

[0023] Figure 1 It is an exploded diagram of a single cell provided in an embodiment of the present application.

[0024] Figure 2 It is a schematic diagram of an insulating film structure provided in an embodiment of the present application.

[0025] Figure 3 yes Figure 2 Left view of .

[0026] Figure 4 yes Figure 2 Bottom view of the .

[0027] Figure 5 yes Figure 4 Enlarged view of point A in the middle.

[0028] Figure 6 This is a schematic diagram of attaching a first plugging sub-membrane provided in an embodiment of the present application.

[0029] Figure 7 yes Figure 6 Left view of .

[0030] Figure 8 yes Figure 6 Bottom view of the .

[0031] Fig. 9 It is a schematic diagram of attaching a first blocking sub-membrane and a second blocking sub-membrane provided in an embodiment of the present application.

[0032] Fig.10 yes Fig. 9 Left view of .

[0033] Fig.11 yes Fig. 9 main view.

[0034] Fig.12 It is a shell cross-sectional view provided in an embodiment of the present application.

[0035] In the figure:

[0036] 10. Shell; 11. Accommodating cavity; 12. Bottom wall; 13. Side wall; 14. Rounded corner;

[0037] 20. Cover body;

[0038] 30. battery cell; 31. top surface; 32. bottom surface; 33. first side surface; 34. second side surface;

[0039] 40. Insulating film; 41. Seam; 42. Overlapping area; 43. Second positioning hole;

[0040] 50. blocking membrane; 51. first blocking sub-membrane; 52. second blocking sub-membrane; 53. overlapping area;

[0041] 60. Isolation layer;

[0042] 70. Bottom supporting plate; 71. First positioning hole. DETAILED DESCRIPTION

[0043] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0044] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or mutual communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0045] In order to solve the problem in the prior art that the sealing film has poor coating and is prone to shell corrosion leading to electrolyte leakage, an embodiment of the present application provides a single cell battery having a first direction and a second direction perpendicular to each other, the single cell battery comprising a shell, a cover, a battery cell, an insulating film and a sealing film, the battery cell having a accommodating cavity; the cover body is covered on the shell to close the accommodating cavity, the first direction is perpendicular to the cover body; the battery cell is accommodated in the accommodating cavity, the battery cell has a top surface and a bottom surface relative to each other in the first direction, and a first side surface and a second side surface extending along the first direction and connected between the outer edges of the bottom surface and the top surface, the top The first side surface is arranged between the bottom surface and the cover body, the area of ​​the first side surface is larger than the area of ​​the second side surface, and the second direction is perpendicular to the first side surface; the insulating film is at least folded and attached to the bottom surface, the first side surface and the second side surface, and there is a seam between the portion of the insulating film attached to the bottom surface and the portion of the insulating film attached to the second side surface; the blocking film includes a first blocking sub-membrane and a second blocking sub-membrane which are separate structures from each other, the first blocking sub-membrane and the second blocking sub-membrane are both attached to the insulating film, and the first blocking sub-membrane and the second blocking sub-membrane are distributed along the second direction to cooperate in blocking the seam. The following is a detailed description.

[0046] See also Figure 1 and Figure 2 In one embodiment, the single cells have a first direction perpendicular to each other (eg Figure 1 , Figure 3 , Figure 7 , Fig.10 and Fig.12 The middle direction Z, the same below), the second direction (as shown in Figure 1 , Figure 3 , Figure 7 , Figure 8 and Fig.10 The middle direction Y, the same below) and the third direction (as shown in Figure 1 , Figure 8 , Fig.11 and Fig.12 The single battery comprises a shell 10, a cover 20, a battery cell 30, an insulating film 40 and a blocking film 50. The shell 10 has a receiving cavity 11. The cover 20 is covered on the shell 10 to close the receiving cavity 11. The first direction is perpendicular to the cover 20. The battery cell 30 is received in the receiving cavity 11. The battery cell 30 has a top surface 31 and a bottom surface 32 relative to each other in the first direction, and a first side surface 33 and a second side surface 34 extending along the first direction and connected between the outer edges of the bottom surface 32 and the top surface 31. The top surface 31 is arranged between the bottom surface 32 and the cover 20. The area of ​​the first side surface 33 is greater than the area of ​​the second side surface 34. The second direction is perpendicular to the first side surface 33.

[0047] It should be noted that the above-mentioned single battery includes but is not limited to lithium-ion secondary batteries, sodium-lithium-ion batteries, sodium-ion batteries or magnesium-ion batteries, etc., and the embodiments of the present disclosure are not limited to this.

[0048] Further, see Fig. 9 and Fig.10 In the above embodiment, the insulating film 40 is attached to the bottom surface 32, the first side surface 33 and the second side surface 34 after being folded. In some embodiments, the insulating film 40 can also be attached to the top surface 31, which will not be repeated here; after the insulating film 40 is folded and attached, a seam 41 is formed between the portion of the insulating film 40 attached to the bottom surface 32 and the portion of the insulating film 40 attached to the second side surface 34, and the seam 41 is sealed by the blocking film 50, which effectively improves the protection effect and blocks the particles (such as active substances, etc., the same below) from contacting the shell 10; the blocking film 50 includes a first blocking sub-membrane 51 and a second blocking sub-membrane 52 which are separate structures from each other, and the first blocking sub-membrane 51 and the second blocking sub-membrane 52 are distributed along the second direction and are both attached to the insulating film 40 to cooperate in blocking the seam 41. In addition, by separately setting the first blocking sub-membrane 51 and the second blocking sub-membrane 52 , the pasting operation of the two is facilitated, the pasting effect is guaranteed, the covering effect of the joint 41 is effectively improved, the protective effect is improved, and the contact between the particles and the shell 10 is blocked.

[0049] It should be noted that the above-mentioned insulating film 40 can be a Mylar film, etc., which will not be repeated here; the above-mentioned blocking film 50 can be made of PP material or PET material, which is determined according to actual usage requirements. When the blocking film 50 (that is, the first blocking sub-membrane 51 and the second blocking sub-membrane 52) needs to be attached to the insulating film 40, it can be pasted by means of adhesive backing. In some embodiments, it can also be pasted by other means, but is not limited to this. The embodiments of the present disclosure are not limited to this.

[0050] Continue reading Fig. 9 In one embodiment, the second blocking sub-membrane 52 is partially attached to the surface of the first blocking sub-membrane 51 facing away from the insulating film 40, and partially extends to the surface of the insulating film 40 facing away from the battery cell 30, that is, the two adjacent ends of the first blocking sub-membrane 51 and the second blocking sub-membrane 52 overlap each other, and the two are overlapped at the edge position. In some embodiments, the two adjacent ends of the first blocking sub-membrane 51 and the second blocking sub-membrane 52 may be bordering, which will not be repeated here. The overlapping of the two adjacent ends of the first blocking sub-membrane 51 and the second blocking sub-membrane 52 further enhances the covering effect of the joint 41; and in this embodiment, the second blocking sub-membrane 52 is arranged on both sides of the first blocking sub-membrane 51 in the second direction, that is, one joint 41 corresponds to two second blocking sub-membranes 52, a part of the first blocking sub-membrane 51 is attached to the surface of the insulating film 40 facing away from the bottom surface 32, and the remaining part extends and is attached to the surface of the insulating film 40 facing away from the second side surface 34 (such as Figure 6 , Figure 7 As shown), the second blocking sub-film 52 is partially attached to the surface of the insulating film 40 facing away from the second side surface 34, partially attached to the surface of the insulating film 40 facing away from the first side surface 33, and the remaining portion is attached to the surface of the insulating film 40 facing away from the bottom surface 32 (as shown in FIG. Figure 9-11 As shown). By providing the first blocking sub-film 51 and the second blocking sub-film 52, the seam 41 can be effectively blocked, and the second blocking sub-film 52 is arranged in this way to cover the four corners of the battery cell 30 (i.e., the two ends of the seam 41 in the second direction), further improving the covering effect.

[0051] See also Figure 5 , Figure 7 and Fig.10In one embodiment, the portion of the insulating film 40 attached to the same second side surface 34 has an overlapping area 42, and the portion where the first blocking sub-membrane 51 and the second blocking sub-membrane 52 overlap is an overlapping area 53, and the orthographic projection of the overlapping area 53 on the second side surface 34 and the orthographic projection of the overlapping area 42 on the second side surface 34 are spaced from each other in the second direction, that is, the orthographic projections of the overlapping area 42 and the overlapping area 53 on the second side surface 34 do not overlap. With this arrangement, when the battery cell 30 (including the insulating film 40 and the blocking film 50) is loaded into the shell 10, the shell 10 will not interfere with the first blocking sub-membrane 51 and the second blocking sub-membrane 52, thereby avoiding the misalignment of the first blocking sub-membrane 51 and the second blocking sub-membrane 52, which is beneficial to improving the protection effect.

[0052] It should be noted that when the orthographic projections of the overlapping area 42 and the overlapping area 53 on the second side surface 34 overlap, the thickness of the battery cell 30 in the third direction before entering the shell will increase, thereby interfering with the shell 10 and affecting the protection performance.

[0053] See also Figure 2 , Figure 4 and Figure 8 In one embodiment, the single cell further comprises a bottom support plate 70, the bottom support plate 70 having a first positioning hole 71, and the portion of the insulating film 40 attached to the bottom surface 32 having a second positioning hole 43, and the bottom support plate 70 is positioned on the side of the insulating film 40 away from the bottom surface 32 through the cooperation of the first positioning hole 71 and the second positioning hole 43; the orthographic projections of the first positioning hole 71 and the second positioning hole 43 on the bottom surface 32 are located within the orthographic projections of the portion of the first blocking sub-membrane 51 attached to the side of the insulating film 40 away from the bottom surface 32 on the bottom surface 32, that is, the portion of the first blocking sub-membrane 51 extending to the bottom surface 32 blocks the first positioning hole 71 and the second positioning hole 43.

[0054] It should be noted that the first sealing sub-membrane 51 is attached to the portion of the insulating film 40 facing away from the bottom surface 32, covering the first positioning hole 71 and the second positioning hole 43. The setting of the first positioning hole 71 and the second positioning hole 43 is conducive to determining the position of the bottom support plate 70, thereby improving the installation efficiency and quality. The setting of the first sealing sub-membrane 51 can seal the first positioning hole 71 and the second positioning hole 43, thereby further improving the covering effect.

[0055] See also Fig.12 In one embodiment, the shell 10 has a bottom wall 12 and a side wall 13 inside, the side wall 13 is arranged around the outer edge of the bottom wall 12, and the bottom wall 12 and the side wall 13 are coated with an isolation layer 60; through the setting of the isolation layer 60, the particles are further blocked from contacting the shell 10, and cooperate with the blocking film 50 to achieve double protection.

[0056] It should be noted that the above-mentioned isolation layer 60 can be an isolation layer 60 of an insulating and corrosion-resistant material such as PVDF film (polyvinylidene fluoride film), PVDF coating (polyvinylidene fluoride coating), PP layer (polypropylene layer), etc., and the embodiments of the present disclosure are not limited to this; and in the above-mentioned embodiment, the isolation layer 60 of the above-mentioned side wall 13 is only coated on the bottom of the side wall 13, that is, in the first direction, the isolation layer 60 is coated on a local area of ​​one end of the side wall 13 close to the bottom wall 12, which can effectively reduce the cost of insulation measures and provide the effectiveness of isolation of the isolation layer 60; when the isolation layer 60 is set in a large area or a large height (the size in the first direction), there are problems of high cost, poor consistency, and high defectivity, which is not conducive to improving the protection effect.

[0057] In one embodiment, in the above-mentioned second direction, the distance between the portions of the insulating film 40 attached to the first side surface 33 is L1mm, and the size of the above-mentioned first blocking sub-film 51 is L2mm, satisfying: 2 / 3≤L2 / L1≤3 / 4, for example, 2 / 3, 3 / 4, etc.; in the first direction, the size of the first blocking sub-film 51 attached to the side of the insulating film 40 facing away from the second side surface 34 is H1mm; in the third direction, the size of the first blocking sub-film 51 attached to the side of the insulating film 40 facing away from the bottom surface 32 is H4mm, satisfying: 0≤H4-H1≤5, for example, 0, 2, 3, 5, etc.; in the second direction, the spacing between the end of the first blocking sub-film 51 and the insulating film 40 close to the end and attached to the first side surface 33 is d2mm, satisfying: 3≤d2≤10, for example, 3, 4.5, 7, 10, etc.; in the first direction, the insulating film 40 is attached to the second side surface 34. The distance from the outer edge of the part close to the bottom surface 32 to the bottom surface 32 is d1mm, satisfying: 0.5≤d1≤1.5, for example, 0.5, 1, 1.5, etc.; in the second direction, the dimension of the second blocking sub-membrane 52 attached to the side of the insulating film 40 facing away from the second side surface 34 is L3mm; in the first direction, the dimension of the second blocking sub-membrane 52 attached to the side of the insulating film 40 facing away from the second side surface 34 is H2mm; in the third direction, the dimension of the second blocking sub-membrane 52 attached to the side of the insulating film 40 facing away from the first side surface 33 is L3mm, satisfying: L3=H2, and 2≤L3-d2≤5, for example, 2, 3.5, 5, etc.; the connection between the above-mentioned side wall 13 and the bottom wall 12 is provided with a fillet 14, the value of the fillet 14 is Rmm, and the dimension of the isolation layer 60 coated on the side wall 13 in the first direction is H3mm, satisfying: 3≤H3-R≤6, for example, 3, 4, 5, 6, etc. In this way, by setting the above parameters, it is beneficial to improve the covering effect of the joint 41 and enhance the protective effect.

[0058] It should be noted that the above embodiment takes the shell 10 having a size of 100 mm in the first direction, 50 mm in the second direction, and 160 mm in the third direction as an example. In addition, the value of R in the above embodiment is 1. The above embodiment reflects whether the shell 10 is corroded by the value of the negative electrode side voltage. Specifically, after the battery cell 30 is placed at room temperature after the capacity division is completed, the negative electrode side voltage is tested. If the negative electrode side voltage is less than 1V, it is determined that the shell 10 has been corroded by lithium insertion. The negative electrode side voltage can be tested by measuring tools such as a domino voltmeter, which will not be repeated here. In addition, each of the above embodiments performs 100EA (i.e., tests 100 single cells) to obtain the corrosion rate of the shell 10, which is represented by η, i.e., η=the number of shell corrosion / 100*100%.

[0059] The technical solution provided in this application is evaluated below in conjunction with specific embodiments.

[0060] Embodiments 1 to 21 are provided. Embodiments 1 to 13 satisfy 2 / 3≤L2 / L1≤3 / 4, 0≤H4-H1≤5, 3≤d2≤10, 0.5≤d1≤1.5, 2≤L3-d2≤5, and 3≤H3-R≤6. Embodiment 14 is a parameter for removing the second blocking sub-membrane 52, Embodiment 15 is a parameter for removing the isolation layer 60, Embodiment 16 is a parameter for simultaneously removing the second blocking sub-membrane 52 and the isolation layer 60, the d1 value in Embodiment 17 does not satisfy 0.5≤d1≤1.5, the H3 value in Embodiments 18 to 19 does not satisfy 3≤H3-R≤6, and the L3 value in Embodiments 20 to 21 does not satisfy 2≤L3-d2≤5. Specific parameters and test results are detailed in Table 1.

[0061] Table 1

[0062]

[0063]

[0064] It can be seen from Table 1 that in the above-mentioned Examples 1 to 3, the value of d1 changes, while the other values ​​remain unchanged; in Examples 2 and 4 to 6, the value of d2 changes, while the other values ​​remain unchanged. It should be noted that the value of d2 is related to L3, so the value of L3 is adjusted accordingly; in Examples 2 and 7 to 9, the value of H3-R changes, while the other values ​​remain unchanged; in Examples 2 and 10 to 12, the value of H4-H1 changes, while the other values ​​remain unchanged; in Examples 2 and 13, the value of L2 / L1 changes, while the other values ​​remain unchanged; in Examples 1 to 13, the value of η is 0, that is, corrosion of the shell 10 is found in all of them. Such a setting is conducive to improving the coating effect of the joint 41 and improving the protection effect. In Examples 14 to 16, the absence of the second blocking sub-film 52 and / or the isolation layer 60 affects the overall coating effect, and the values ​​of η are 2%, 5%, and 30%, respectively; in Example 17, η=6%, the d1 value is too large, that is, the opening of the seam 41 is too large, and there is a risk of a large amount of negative electrode particles leaking out. In addition, when the d1 value is 0.2, the opening of the seam 41 is too small, and the insulating film 40 is difficult to manufacture, and the relevant structure cannot be obtained, so it is not discussed in the above embodiments; in Example 18, η=10%, at this time the value of H3 is 2, the height of the isolation layer 60 at the bottom of the shell 10 is too low, and under the action of the flowing electrolyte at the bottom of the battery cell, the negative electrode particles contact the shell 10, resulting in corrosion; Example 1 9, η=7%, at this time the value of H3 is 10, the height of the isolation layer 60 at the bottom of the shell 10 is too high, resulting in poor consistency of the blocking film 50 and the isolation layer 60 that play an isolating role, resulting in a lower barrier effect, that is, the coating is reduced; in Example 20, the value of L3 is 4, η=1%, the value of L3 is too small, resulting in poor protection effect of the second blocking sub-membrane 52, and there is a problem of leakage of negative electrode particles; in Example 21, the value of L3 is 13, η=3%, the value of L3 is too large, at this time the overlap area 42 and the overlap area 53 have overlapping projections on the second side 34, which will increase the thickness of the battery cell 30 in the third direction before entering the shell, and then interfere with the shell 10, thereby weakening the protection effect.

[0065] On the other hand, the present application also provides a battery pack, comprising any one of the aforementioned single cells.

[0066] The single cell and battery pack provided in the embodiments of the present application are introduced in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A single cell battery, characterized in that: Having a first direction (Z) and a second direction (Y) perpendicular to each other, the single battery comprises: A housing (10) having a receiving cavity (11); A cover body (20) is covered on the shell (10) to close the accommodating cavity (11), and the first direction (Z) is perpendicular to the cover body (20); A battery cell (30) is accommodated in the accommodation cavity (11), the battery cell (30) having a top surface (31) and a bottom surface (32) opposite to each other in the first direction (Z), and a first side surface (33) and a second side surface (34) extending along the first direction (Z) and connected between the outer edges of the bottom surface (32) and the top surface (31), the top surface (31) being arranged between the bottom surface (32) and the cover body (20), the area of ​​the first side surface (33) being larger than the area of ​​the second side surface (34), and the second direction (Y) being perpendicular to the first side surface (33); an insulating film (40) at least folded and attached to the bottom surface (32), the first side surface (33) and the second side surface (34), wherein a seam (41) is formed between a portion of the insulating film (40) attached to the bottom surface (32) and a portion of the insulating film (40) attached to the second side surface (34); and The sealing film (50) comprises a first sealing sub-membrane (51) and a second sealing sub-membrane (52) which are separate structures from each other, wherein the first sealing sub-membrane (51) and the second sealing sub-membrane (52) are both attached to the insulating film (40), and the first sealing sub-membrane (51) and the second sealing sub-membrane (52) are distributed along the second direction (Y) to cooperate in sealing the joint (41).

2. The single cell according to claim 1, characterized in that: The second blocking sub-film (52) is partially attached to the surface of the first blocking sub-film (51) facing away from the insulating film (40), and partially extends to be attached to the surface of the insulating film (40) facing away from the battery cell (30).

3. The single cell according to claim 2, characterized in that: The portion of the insulating film (40) attached to the same second side surface (34) has an overlapping area (42), and the portion where the first blocking sub-membrane (51) overlaps with the second blocking sub-membrane (52) is an overlapping area (53), and the orthographic projection of the overlapping area (53) on the second side surface (34) and the orthographic projection of the overlapping area (42) on the second side surface (34) are spaced apart from each other in the second direction (Y).

4. The single cell according to claim 2, characterized in that: In the second direction (Y), the second blocking sub-membrane (52) is arranged on both sides of the first blocking sub-membrane (51), the first blocking sub-membrane (51) is partially attached to the surface of the insulating film (40) facing away from the bottom surface (32), and the remaining part is attached to the surface of the insulating film (40) facing away from the second side surface (34); the second blocking sub-membrane (52) is partially attached to the surface of the insulating film (40) facing away from the second side surface (34), partially attached to the surface of the insulating film (40) facing away from the first side surface (33), and the remaining part is attached to the surface of the insulating film (40) facing away from the bottom surface (32).

5. The single cell according to claim 4, characterized in that: The single battery further comprises a bottom support plate (70), the bottom support plate (70) having a first positioning hole (71), a portion of the insulating film (40) attached to the bottom surface (32) having a second positioning hole (43), and the bottom support plate (70) is positioned on a side of the insulating film (40) away from the bottom surface (32) through the cooperation between the first positioning hole (71) and the second positioning hole (43); The first blocking sub-membrane (51) extends to a portion of the bottom surface (32) to cover the first positioning hole (71) and the second positioning hole (43).

6. The single cell according to claim 4, characterized in that: In the second direction (Y), the distance between the portions of the insulating film (40) attached to the first side surface (33) is L1 mm, and the size of the first blocking sub-membrane is L2 mm, satisfying: 2 / 3≤L2 / L1≤3 / 4.

7. The single cell according to claim 4, characterized in that: The single cell further includes a third direction (X), wherein the third direction (X) is perpendicular to the second side surface (34); In the first direction (Z), the dimension of the first blocking sub-membrane (51) attached to the insulating film (40) facing away from the second side surface (34) is H1mm; in the third direction (X), the dimension of the first blocking sub-membrane (51) attached to the insulating film (40) facing away from the bottom surface (32) is H4mm, satisfying: 0≤H4-H1≤5.

8. The single cell according to claim 4, characterized in that: In the second direction (Y), the distance between the end of the first blocking sub-film (51) and the insulating film (40) close to the end and attached to the first side surface (33) is d2 mm, satisfying: 3≤d2≤10.

9. The single cell according to claim 8, characterized in that: The single cell further includes a third direction (X), wherein the third direction (X) is perpendicular to the second side surface (34); In the second direction (Y), the dimension of the second blocking sub-film (52) attached to the side of the insulating film (40) facing away from the second side surface (34) is L3 mm; In the first direction (Z), the dimension of the second blocking sub-film (52) attached to the side of the insulating film (40) facing away from the second side surface (34) is H2 mm; In the third direction (X), the dimension of the second blocking sub-film (52) attached to the side of the insulating film (40) facing away from the first side surface (33) is L3 mm, satisfying: L3=H2, and 2≤L3-d2≤5.

10. The single cell according to claim 1, characterized in that: The shell (10) has a bottom wall (12) and a side wall (13) inside, the side wall (13) is arranged around the outer edge of the bottom wall (12), and the bottom wall (12) and the side wall (13) are coated with an isolation layer (60).

11. The single cell according to claim 10, characterized in that: The connection between the side wall (13) and the bottom wall (12) is provided with a rounded corner (14), the value of the rounded corner (14) is Rmm, the size of the isolation layer (60) coated on the side wall (13) in the first direction (Z) is H3mm, and satisfies: 3≤H3-R≤6.

12. The single cell according to claim 1, characterized in that: In the first direction (Z), the distance from the outer edge of the portion of the insulating film (40) attached to the second side surface (34) close to the bottom surface (32) to the bottom surface (32) is d1 mm, satisfying: 0.5≤d1≤1.

5.

13. A battery pack, characterized in that: The method comprises a single cell as claimed in any one of claims 1 to 12.

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