Single cell

Abstract

This utility model provides a single-cell battery. The single-cell battery includes: a casing, a cover assembly, an electrode assembly, and an insulating film. The cover assembly is disposed on the casing and, together with the casing, defines a receiving cavity. The cover assembly includes a cover body and an insulating component. The side of the cover body facing the receiving cavity is an inner wall, and the insulating component is connected to the inner wall. The electrode assembly is housed within the receiving cavity. The insulating film covers the electrode assembly, and the end of the insulating film has a connection area that connects to the insulating component. Along the thickness direction of the insulating component, the distance from the edge of the end of the insulating film to the inner wall is greater than zero, and the connection area between the connection area and the insulating component accounts for more than 50% of the area of ​​the connection area. By ensuring that the distance from the edge of the end of the insulating film to the inner wall is greater than zero, interference of the insulating film during the welding process between the cover assembly and the casing can be prevented. By ensuring that the connection area between the connection area and the insulating component accounts for more than 50% of the area of ​​the connection area, the connection strength between the connection area and the insulating component is ensured.

Description

Technical Field

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

[0002] In recent years, with the rapid development of electric vehicles, consumer electronics, and new energy storage systems, battery technology has become an important factor in the development of electric vehicles.

[0003] In the development of battery technology, how to improve the yield rate of battery cells is a technical problem that urgently needs to be solved. Utility Model Content

[0004] The technical problem to be solved by this utility model is to overcome the above-mentioned technical problems of the prior art and provide a single cell battery.

[0005] The present invention solves the above-mentioned technical problems through the following technical solution:

[0006] A single-cell battery, characterized in that the single-cell battery comprises:

[0007] case;

[0008] A cover plate assembly is disposed on the housing and together with the housing defines a receiving cavity. The cover plate assembly includes a cover plate body and an insulating member. The side of the cover plate body facing the receiving cavity is an inner wall, and the insulating member is connected to the inner wall.

[0009] The electrode assembly is housed within the receiving cavity;

[0010] An insulating film covers the electrode assembly, and the end of the insulating film has a connection area that connects to the insulating element;

[0011] Wherein, along the thickness direction of the insulating component, the distance from the edge of the end of the insulating film to the inner wall is greater than zero, and the connection area between the connection region and the insulating component accounts for more than 50% of the area of ​​the connection region.

[0012] Preferably, along the thickness direction of the insulating member, the connection area includes a first edge near the inner wall and a second edge away from the inner wall, and the insulating member includes a third edge near the inner wall and a fourth edge away from the inner wall;

[0013] Along the thickness direction of the insulating element, the second edge of the connecting region is closer to the inner wall than the fourth edge of the insulating element; and / or,

[0014] Along the thickness direction of the insulating element, the distance from the first edge of the connection area to the inner wall is greater than 0.5 mm.

[0015] Preferably, the insulating film includes a film body and a thickened portion, the thickened portion being located at the end, and the thickened portion being laminated with the film body along the thickness direction of the insulating film to form a thickened region, and the connecting region being at least partially located in the thickened region.

[0016] Preferably, the thickened region comprises two or more layers of the film body, and the thickened portion is located on the side of the insulating film facing the insulating member; and / or,

[0017] The ratio of the thickness of the thickened region to the thickness of the membrane body is 1.2-2.5; the thickness of the membrane body is 0.08mm-0.15mm, and the thickness of the thickened region is 0.1mm-0.2mm.

[0018] Preferably, along the thickness direction of the insulating film, the thickened portion is a single film body, which is formed by folding the film body toward the insulating member, or the thickened portion is formed by stacking multiple layers of the film body.

[0019] Preferably, the thickened region further includes an adhesive layer;

[0020] When the thickened portion is a single layer of the film body, the adhesive layer is located between the film body and the thickened portion along the thickness direction of the insulating film.

[0021] When the thickened portion is a multilayer membrane, the adhesive layer is located between the membrane body and the thickened portion along the thickness direction of the insulating film, and / or the adhesive layer is located between two adjacent membrane bodies in the thickened portion.

[0022] Preferably, along the circumferential direction of the insulating member, the end is connected to the insulating member, and the end includes an overlapping region and a non-overlapping region, both of which contain two film bodies.

[0023] Preferably, along the thickness direction of the insulating member, the connecting region includes a first edge near the inner wall and a second edge away from the inner wall; the insulating member includes a third edge near the inner wall and a fourth edge away from the inner wall; the thickened region includes a fifth edge near the inner wall and a sixth edge away from the inner wall.

[0024] Along the thickness direction of the insulating member, the thickened region is located between the third and fourth edges of the insulating member, the connecting region is located between the fifth and sixth edges of the thickened region, and the distance from the second edge of the connecting region to the sixth edge of the thickened portion is ≥1.5mm.

[0025] Preferably, the connection area is thermally fused to the insulating element; and / or,

[0026] The number of connection areas is multiple, and the multiple connection areas are arranged at intervals along the circumference of the insulating member.

[0027] Preferably, the insulating element includes a protrusion located on the side of the insulating element away from the inner wall, and the connecting region is at least partially thermally fused to the protrusion.

[0028] The positive and progressive effects of this utility model are as follows:

[0029] In this invention, by setting the distance from the edge of the insulating film to the inner wall to be greater than zero along the thickness direction of the insulating component, interference of the insulating film with the welding process between the cover plate assembly and the shell can be prevented, thereby improving the yield of the battery. By setting the connection area between the connection area and the insulating component to account for more than 50% of the connection area area, the connection strength between the connection area and the insulating component is ensured, thereby improving the tensile strength of this area as the joint between the insulating film and the insulating component, preventing cracking under vibration or impact, and preventing puncture by the tabs, reducing the risk of internal short circuits in the battery, and thus improving the yield of the battery. Attached Figure Description

[0030] Figure 1 This is a three-dimensional structural diagram (I) of a preferred embodiment of the present invention for a single cell battery.

[0031] Figure 2 This is a three-dimensional exploded structural diagram (I) of a preferred embodiment of the present invention's single-cell battery.

[0032] Figure 3 This is a three-dimensional structural diagram (I) of the insulating film of a single cell battery according to a preferred embodiment of the present invention.

[0033] Figure 4 This is a schematic diagram (I) of the unfolded state of the insulating film according to a preferred embodiment of the present invention.

[0034] Figure 5 This is a partial cross-sectional view of an embodiment of the insulating film of a preferred embodiment of the present invention.

[0035] Figure 6 This is a partial cross-sectional view of another embodiment of the insulating film of a preferred embodiment of the present invention.

[0036] Figure 7 This is a partial cross-sectional view of another embodiment of the insulating film of a preferred embodiment of the present invention.

[0037] Figure 8 This is a partial front view structural diagram of a single battery cell according to a preferred embodiment of the present invention.

[0038] Figure 9 for Figure 8 A magnified view of the structure in section A.

[0039] Figure 10 This is a partial front view structural schematic diagram of another embodiment of the single cell battery of a preferred embodiment of the present invention.

[0040] Figure 11 This is a three-dimensional structural diagram (II) of a single cell battery according to a preferred embodiment of the present invention.

[0041] Figure 12 This is a three-dimensional exploded view (II) of a preferred embodiment of the present invention of a single cell battery.

[0042] Figure 13 This is a three-dimensional structural diagram (II) of the insulating film of a single cell battery according to a preferred embodiment of the present invention.

[0043] Figure 14 This is a schematic diagram (II) of the structure of the insulating film in the unfolded state of a preferred embodiment of the present invention.

[0044] Explanation of reference numerals in the attached figures

[0045] 100 single cell

[0046] Casing 1

[0047] Cover plate assembly 2

[0048] Cover body 21

[0049] Inner wall 211

[0050] Insulating component 22

[0051] Third Edge 221

[0052] Fourth Edge 222

[0053] Protrusion 223

[0054] Reception cavity 3

[0055] Electrode assembly 4

[0056] Electrode 43

[0057] Insulating film 5

[0058] End 51

[0059] Overlapping region 511

[0060] Non-overlapping region 512

[0061] Connection area 52

[0062] First Edge 521

[0063] Second edge 522

[0064] Membrane body 53

[0065] First end 531

[0066] Second end 532

[0067] First paragraph 533

[0068] Middle section 534

[0069] Second paragraph 535

[0070] Thickened part 54

[0071] Thickened area 55

[0072] Fifth Edge 551

[0073] Sixth Edge 552

[0074] Adhesive layer 56

[0075] The thickness t1 of the membrane body

[0076] Thickness t2 of the thickened area

[0077] The height h of the connecting area

[0078] The distance h1 from the first edge to the inner wall

[0079] The distance h2 from the second edge to the sixth edge

[0080] The distance h3 from the edge of the insulating film to the inner wall

[0081] The thickness direction T1 of the insulating film

[0082] Thickness direction T2 of the insulating component

[0083] First preset direction Q1

[0084] Second preset direction Q2

[0085] Height direction H Detailed Implementation

[0086] The present invention will be described more clearly and completely below with reference to the accompanying drawings, using a preferred embodiment.

[0087] In existing technology, the insulating film is folded and wrapped around the bottom and sides of the electrode assembly. The insulating film needs to be fixedly connected to the insulating component of the cover assembly by heat fusion to ensure the insulation between the electrode assembly and the housing. However, when the insulating film is too close to the cover body of the cover assembly, it will affect the welding of the cover body and the housing, thus reducing the yield of the battery. Furthermore, when the connection area between the insulating film and the insulating component is too small, the tensile strength at the joint between the insulating film and the insulating component will be insufficient, making it prone to cracking under vibration or impact, and more easily punctured by the tabs, increasing the risk of internal short circuits in the battery and also reducing the yield of the battery.

[0088] like Figure 1 and Figure 2 As shown, this embodiment provides a single-cell battery 100. The single-cell battery 100 includes: a housing 1, a cover plate assembly 2, an electrode assembly 4, and an insulating film 5.

[0089] The cover assembly 2 is placed on the housing 1 and together with the housing 1 defines the receiving cavity 3. The cover assembly 2 includes a cover body 21 and an insulating member 22. The side of the cover body 21 facing the receiving cavity 3 is an inner wall 211, and the insulating member 22 is connected to the inner wall 211.

[0090] The electrode assembly 4 is housed within the receiving cavity 3.

[0091] like Figure 3 As shown, the insulating film 5 covers the electrode assembly 4, and the end 51 of the insulating film 5 has a connection area 52 that connects to the insulating member 22. The distance h3 from the edge of the end 51 of the insulating film 5 to the inner wall 211 is greater than zero, and the connection area between the connection area 52 and the insulating member 22 accounts for more than 50% of the area of ​​the connection area 52.

[0092] In this way, by setting the distance h3 from the edge of the end 51 of the insulating film 5 to the inner wall 211 to be greater than zero, the insulating film 5 is prevented from affecting the welding of the cover plate body 21 and the shell 1. That is, the insulating film 5 is prevented from interfering with the welding process of the cover plate assembly 2 and the shell 1, thereby improving the yield of the battery. It should be noted that since the distance h3 from the edge of the end 51 of the insulating film 5 to the inner wall 211 is greater than zero, the distance from the first edge 521 of the connection area 52 on the insulating film 5 to the inner wall 211 of the cover plate body 21 must also be greater than zero. By setting the connection area between the connection area 52 and the insulating component 22 to account for more than 50% of the area of ​​the connection area 52, the effective connection between the connection area 52 and the insulating component 22, as well as the connection strength between the connection area 52 and the insulating component 22, is ensured. This improves the tensile strength of this area as the joint between the insulating film 5 and the insulating component 22, prevents cracking under vibration or impact, and prevents puncture by the tab 43, reduces the risk of internal short circuit in the battery, and improves the yield of the battery.

[0093] It should be noted that the connection area 52 refers to the area where the insulating film 5 can be connected to the insulating component 22. This area is formed by heat melting or by coating an adhesive layer, enabling the area to be fixedly connected to the insulating component 22. The connection area between the connection area 52 and the insulating component 22 accounts for more than 50% of the area of ​​the connection area 52. In other words, at least 50% of the area of ​​the connection area 52 is actually fixedly connected to the insulating component 22.

[0094] Specifically, the insulating film 5 includes a film body 53 and a thickened portion 54. The thickened portion 54 is located at the end 51 of the insulating film 5. Along the thickness direction T1 of the insulating film 5, the thickened portion 54 and the film body 53 are stacked to form a thickened region 55. The connecting region 52 is at least partially located in the thickened region 55, and the thickened region 55 is connected to the insulating member 22 of the cover plate assembly 2 through the connecting region 52.

[0095] In this way, by setting the thickened region 55 of the insulating film 5 to connect the connecting region 52 with the insulating member 22, that is, the region where the insulating film 5 connects with the cover plate assembly 2 of the single cell 100 is the thickened region 55 formed by the thickened part 54 and the film body 53 stacked together, thereby increasing the thickness of the connecting region 52 of the insulating member 22 that connects the insulating film 5 and the cover plate assembly 2 of the single cell 100. This increases the tensile strength of this region as the joint between the insulating film 5 and the insulating member 22, preventing cracking under vibration or impact and puncture by the tab 43, reducing the risk of internal short circuit in the battery, and improving the yield of the battery. Since the insulating film 5 is connected to the insulating member 22 at the end 51, the thickened region 55 must also be located at the end 51 of the insulating film 5. The number and position of the ends 51 are determined by the corresponding insulating member 22.

[0096] It should be noted that the connecting area 52 is at least partially located in the thickened area 55, including two cases: one is that the connecting area 52 is partially located in the thickened area 55, and the other is that the connecting area 52 is entirely located in the thickened area 55.

[0097] like Figure 4 The diagram shown is an unfolded structural view of the insulating film 5 in this embodiment before it covers the electrode assembly 4. At this time, the connection region 52 has not yet been formed on the insulating film 5. Along the first preset direction Q1, the thickened portion 54 is located at the opposite first end 531 and second end 532 of the film body 53.

[0098] It should be noted that the first preset direction Q1 can be the length direction of the unfolded insulating film 5, or the width direction or other directions, which is determined by the way the insulating film 5 covers the electrode assembly 4 of the single cell 100, and the area where the insulating film 5 is connected to the cover assembly 2 of the single cell 100.

[0099] Along a second preset direction Q2 that is not parallel to the first preset direction Q1, both the first end 531 and the second end 532 include opposing first segments 533 and second segments 535, and an intermediate segment 534 located between the first segments 533 and second segments 535. The first segments 533 and second segments 535 are single-layer film bodies 53, and the intermediate segment 534 includes two film bodies 53 to provide a uniform thickness for the connection areas at different locations, ensuring consistent process parameters in the connection areas at different locations and improving the yield of the battery product. Figure 4 In order to better distinguish the middle section 534, the position of the middle section 534 is marked with a section line.

[0100] However, this is not the only embodiment. In other embodiments, the first segment 533, the second segment 535, and the middle segment 534 may each include two membrane bodies 53.

[0101] Since the electrode assembly 4 of the single unit covered by the insulating film 5 in this embodiment is an electrode assembly 4 with a single-sided tab 43, after the insulating film 5 covers the outside of the electrode assembly 4, the thickened area 55 will be located at one end 51 of the insulating film 5 when connected to the insulating member 22. Please refer to [link to relevant documentation]. Figure 3 .

[0102] like Figure 5 As shown, in one embodiment of this example, along the thickness direction T1 of the insulating film 5, the thickened portion 54 is a film body 53. The thickened portion 54 is formed by folding the film body 53. In this way, by forming the thickened portion 54 by folding the film body 53, the thickened portion 54 of the thickened region 55 and the film body 53 can be pre-positioned by the connection points where they are connected during folding, without the need for other fixing methods for pre-positioning. In addition, the thickened region 55 formed by folding has higher shape and dimensional stability during transfer, positioning and heat fusion processes, and is less prone to misalignment that could affect the sealing welding of the cover plate assembly 2 and the housing 1.

[0103] It should be noted that there are two ways to bend the membrane body 53. One way is as in this embodiment, where the membrane body 53 bends towards the side closer to the electrode assembly 4. That is, after bending the membrane body 53 inward, a thickened region 55 is formed, and thus, the thickened portion 54 is located on the side of the insulating film 5 facing the cover plate assembly 2. However, it is not limited to this. Another way is that the membrane body 53 bends away from the electrode assembly 4. That is, after bending the membrane body 53 outward, a thickened region 55 is formed, and thus, the thickened portion 54 is located on the side of the insulating film 5 away from the cover plate assembly 2. In this way, whether the thickened region 55 is formed by bending inward or outward, the layers of the thickened region 55 can be pre-positioned by the connection points where they are connected during folding, without the need for other fixing methods for pre-positioning. In addition, the thickened region 55 formed by folding has higher shape and dimensional stability during transfer, positioning, and heat melting, and is less likely to be misaligned and affect the sealing welding of the cover plate assembly 2 and the shell 1.

[0104] The thickened region 55 formed by bending the membrane body 53 inward is preferred because the thickened region 55 formed by bending inward will not interfere with the assembly path when assembling the shell 1 later (the thickened region 55 formed by bending outward is prone to local outward warping, thus interfering with the insertion into the shell).

[0105] But not limited to this, such as Figure 6 As shown, in another embodiment of this example, along the thickness direction T1 of the insulating film 5, the thickened portion 54 is formed by stacking multiple film bodies 53.

[0106] like Figure 7 As shown, the formation of the thickened portion 54 is not limited to being formed by folding the membrane body 53. In another embodiment of this example, the thickened portion 54 is a coating structure, that is, the thickened portion 54 is formed on the membrane body 53 by coating. The coating material is PET (Polyethylene terephthalate), and the coating thickness is 0.03mm-0.2mm.

[0107] Preferably, the thickness t2 of the thickened region 55 is 0.1mm-0.2mm, for example, it can be 0.1mm, 0.13mm, 0.15mm, 0.17mm or 0.2mm. By setting the range of the thickness t2 of the thickened region 55, on the one hand, it avoids the thickened region 55 being too thick, thereby increasing the overall volume of the battery and reducing the energy density of the battery; on the other hand, it avoids the thickened region 55 being too thin, which would result in insufficient tensile strength at the joint between the insulating film 5 and the insulating component 22, making it easy to crack under vibration or impact, and easier to be punctured by the tab 43, increasing the risk of internal short circuits in the battery and reducing the yield rate of the battery.

[0108] The thickness t1 of the membrane body 53 is 0.08mm-0.15mm, for example, it can be 0.08mm, 0.1mm, 0.115mm, 0.14mm or 0.15mm. By setting the range of the thickness t1 of the membrane body 53, on the one hand, it avoids the membrane body 53 being too thick, thereby increasing the overall volume of the battery and reducing the energy density of the battery; on the other hand, it avoids the membrane body 53 being too thin, thereby reducing the overall structural strength and affecting the insulation performance.

[0109] Regarding the thickness of the membrane body 53, when the thickness t1 of the membrane body 53 is 0.08mm-0.15mm, it belongs to a relatively thin insulating film 5 structure. This relatively thin insulating film 5 structure can effectively reduce manufacturing costs, and because it is thinner, it can reduce the overall volume of the battery, thereby increasing the energy density of the battery. However, during the hot-melt connection of the insulating film 5 and the insulating component 22, within the aforementioned thickness range, numerous technical problems can easily arise, such as low mechanical strength or large hot-melt deformation. Furthermore, thinner substrates also significantly impact the processing window. Therefore, this is addressed by using a multi-layer structure in the connection area 52: Firstly, the multi-layer structure can alleviate and disperse stress during the hot-melt and curing processes, maintaining good flatness after welding and preventing large burrs caused by surface unevenness, which could affect the sealing welding of the cover assembly 2 and the shell 1. Secondly, thinner single-layer structures are prone to localized weak points (caused by uneven thickness) during material forming. The multi-layer structure can reduce the adverse effects of these weak points on the connection strength after hot-melt connection. Furthermore, the multi-layer structure can prevent excessive degradation or incomplete melting of single-layer structures during hot-melt processes when temperature or pressure deviates, thus affecting connection strength. Additionally, the multi-layer structure also alleviates stress concentration at the hot-melt point edge after hot-melt, preventing tearing at the hot-melt point during battery vibration.

[0110] Preferably, the thickened region 55 further includes an adhesive layer 56; when the thickened portion 54 is a single membrane body 53, the adhesive layer 56 is located between the membrane body 53 and the thickened portion 54 along the thickness direction T1 of the insulating film 5; when the thickened portion 54 is a multilayer membrane body 53, the adhesive layer 56 is located between the membrane body 53 and the thickened portion 54 along the thickness direction T1 of the insulating film 5, and / or, the adhesive layer 56 is located between two adjacent membrane bodies 53 in the thickened portion 54. By providing the adhesive layer 56, on the one hand, the thickened region 55 can be bonded together in advance to form a stable structure before being connected to the insulating member 22, making it easier to fix and heat-melt the insulating film 5 during the connection process with the insulating member 22. On the other hand, it can avoid the problem of delamination edge cracking when the connection region 52 and the insulating member 22 are fixedly connected by heat fusion. However, it is not limited to this; in other embodiments, the membrane body 53 and the thickened portion 54 can also be fixedly connected together by heat fusion.

[0111] Furthermore, at least 50% of the orthographic projection of the adhesive layer 56 along the thickness direction T1 of the insulating film 5 is located within the outer edge of the thickened portion 54, thereby ensuring the fixation between the thickened portion 54 and the film body 53, as well as between two adjacent film bodies 53 in the thickened portion 54. The thickness of the adhesive layer 56 is 0.01mm-0.02mm.

[0112] Preferably, the ratio of the thickness t2 of the thickened region 55 to the thickness t1 of the membrane body 53 is 1.2-2.5. Specifically, when the thickened portion 54 is a coating structure, since the coating structure is relatively thin, the minimum ratio of the thickness t2 of the thickened region 55 to the thickness t1 of the membrane body 53 is 1.2. When the thickened portion 54 is formed by folding the membrane body 53, the thickness t2 of the thickened region 55 is twice the thickness t1 of the membrane body 53, plus the thickness of the adhesive layer 56. That is, the ratio of the thickness t2 of the thickened region 55 to the thickness t1 of the membrane body 53 will be greater than 2 and less than 3. By setting the range of the ratio of the thickness t2 of the thickened region 55 to the thickness t1 of the membrane body 53, the relationship between the thickened region 55 and the membrane body 53 can be effectively controlled, avoiding excessive stacking of the membrane body 53 which would increase the thickness of the thickened region 55, thereby increasing the overall volume of the battery and reducing the energy density of the battery.

[0113] Preferably, the connecting area 52 is thermally fused to the insulating member 22. However, it is not limited to this; the connecting area 52 may also be fixed to the insulating member 22 by adhesive or other means.

[0114] Preferably, there are multiple connection areas 52, which are spaced apart circumferentially along the insulating member 22. By providing multiple connection areas 52, more connection points can be provided, resulting in a more secure connection between the insulating film 5 and the insulating member 22. Furthermore, by spaced multiple connection areas 52 circumferentially along the insulating member 22, the stress points can be distributed, thereby improving the overall tensile strength.

[0115] like Figure 8 and Figure 9As shown, in this embodiment, along the thickness direction T2 of the insulating member 22, the connecting region 52 includes a first edge 521 near the inner wall 211 and a second edge 522 away from the inner wall 211; the insulating member 22 includes a third edge 221 near the inner wall 211 and a fourth edge 222 away from the inner wall 211; the thickened region 55 includes a fifth edge 551 near the inner wall 211 and a sixth edge 552 away from the inner wall 211. It should be noted that in this embodiment, the thickness direction T2 of the insulating member 22 is in the same direction as the height direction H of the single battery 100, but this is not a limitation. In other embodiments, the thickness direction T2 of the insulating member 22 may also be in the same direction as the length direction of the single battery 100, depending on the design of the single battery 100.

[0116] Along the thickness direction T2 of the insulating member 22, the second edge 522 is closer to the inner wall 211 than the fourth edge 222. That is, the second edge 522 of the connecting region 52 away from the inner wall 211 is closer to the inner wall 211 than the fourth edge 222 of the insulating member 22 away from the inner wall 211. In other words, the connection area between the connecting region 52 and the insulating member 22 accounts for 100% of the area of ​​the connecting region 52, and 100% of the connecting region 52 is located on the insulating member 22, thereby effectively ensuring the connection strength between the insulating film 5 and the insulating member 22.

[0117] But not limited to this, such as Figure 10 As shown, in another embodiment of this example, the percentage of the connection area of ​​the connection region 52 and the insulating member 22 to the area of ​​the connection region 52 can also be 50%, or 65%, 78%, 89% or 99%, etc.

[0118] Along the thickness direction T2 of the insulating member 22, the distance h1 from the first edge 521 to the inner wall 211 is greater than 0.5mm. That is, the distance h1 from the first edge 521 of the connecting area 52 near the inner wall 211 to the inner wall 211 is greater than 0.5mm. This can effectively prevent interference between the connecting area 52 and the cover plate body 21. Specifically, it avoids the heat generated by the hot melt from adversely affecting the cover plate body 21 when the connecting area 52 and the insulating member 22 located below the cover plate body 21 are fixed by hot melt.

[0119] Along the thickness direction T2 of the insulating member 22, the thickened region 55 is located between the third edge 221 and the fourth edge 222, and the connecting region 52 is located between the fifth edge 551 and the sixth edge 552. That is, by setting the connecting region 52 to be completely located on the thickened region 55, while the thickened region 55 is completely located on the insulating member 22, the connection strength between the insulating film 5 and the insulating member 22 is effectively guaranteed, while preventing interference between the connecting region 52 and the surrounding components.

[0120] The distance h2 from the second edge 522 to the sixth edge 552 is greater than or equal to 1.5 mm. That is, the range of h2 between the second edge 522 of the connecting area 52 away from the inner wall 211 and the sixth edge 552 of the thickened area 55 away from the inner wall 211 is greater than or equal to 1.5 mm, thereby ensuring that the connecting area 52 is entirely located within the thickened area 55, so that the thickness of the entire connecting area 52 is uniform and effectively thickened.

[0121] Along the thickness direction T2 of the insulating member 22, the dimension h of each connecting area 52 is 1mm-3mm. By setting the range of the dimension h of the connecting area 52 along the thickness direction T2 of the insulating member 22, on the one hand, the dimension h is too small and cannot play a good fixing role, and on the other hand, the dimension h is too large and will interfere with the surrounding components.

[0122] Preferably, the insulating member 22 includes a protrusion 223 located on the side of the insulating member 22 away from the inner wall 211, and the connecting region 52 is at least partially heat-fused to the protrusion 223.

[0123] Please refer to the following: Figure 3 The end 51 is connected to the insulating member 22 along the circumferential direction of the insulating member 22. The end 51 includes an overlapping region 511 and a non-overlapping region 512. Both the overlapping region 511 and the non-overlapping region 512 contain two layers of membrane body 53.

[0124] As mentioned above, the first end 531 and the second end 532 of the unfolded insulating film 5 each include a first segment 533 and a second segment 535, and an intermediate segment 534 located between the first segment 533 and the second segment 535. Corresponding to the insulating film 5 after being covered onto the electrode assembly, that is, the end 51 of the insulating film 5 includes an overlapping region 511 and a non-overlapping region 512, wherein the overlapping region 511 is formed by stacking the first segment 533 and the second segment 535 after they are covered onto the electrode assembly 4. Thus, by setting the overlapping region 511 and the non-overlapping region 512 to both contain two layers of film body 53, a uniform thickness is provided for the connection regions 52 at different locations, so that the process parameters of the connection regions at different locations are consistent, thereby improving the yield of the battery products.

[0125] Preferably, the overlapping region 511 and the non-overlapping region 512 are connected to the insulating member 22 by a plurality of connecting regions 52, which are spaced apart circumferentially along the insulating member 22.

[0126] Please refer to the following: Figure 2 and Figure 3In this embodiment, the electrode assembly 4 of the single cell 100 is a single-sided electrode assembly 4 with a tab 43. Thus, there is only one insulating member 22 in the single cell 100. As mentioned above, the number and position of the ends 51 are determined by the corresponding insulating member 22. Therefore, after the insulating film 5 covers the outside of the electrode assembly 4, the thickened area 55 will be located at one end 51 of the insulating film 5 when it is connected to the insulating member 22.

[0127] But not limited to this, such as Figures 11-13 As shown, in another embodiment of the single-cell battery 100 in this example, the electrode assembly 4 of the single-cell battery 100 is an electrode assembly 4 with dual-sided tabs 43. Therefore, the single-cell battery 100 contains two opposing insulating members 22. Correspondingly, after the insulating film 5 covers the electrode assembly 4, the thickened region 55, when connected to the insulating member 22, is located at the two opposing ends 51 of the insulating film 5. The structure of the insulating film 5 in its unfolded state in this embodiment is as follows: Figure 14 As shown, with Figure 4 The structure of the insulating film 5 is slightly different.

[0128] This embodiment improves the battery yield by setting the distance h3 from the edge of the end 51 of the insulating film 5 to the inner wall 211 to be greater than zero, thus preventing the insulating film 5 from affecting the welding of the cover body 21 and the shell 1. By setting the connection area between the connection area 52 and the insulating component 22 to account for more than 50% of the area of ​​the connection area 52, the effective connection between the connection area 52 and the insulating component 22, as well as the connection strength between the connection area 52 and the insulating component 22, is ensured. This improves the tensile strength of this area as the joint between the insulating film 5 and the insulating component 22, preventing cracking under vibration or impact, and puncture by the tab 43, reducing the risk of internal short circuits in the battery, and thus improving the battery yield.

[0129] While specific embodiments of this utility model have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of this utility model is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of this utility model, but all such changes and modifications fall within the scope of protection of this utility model.

Claims

1. A single-cell battery, characterized in that, The single battery cell includes: case; A cover plate assembly is disposed on the housing and together with the housing defines a receiving cavity. The cover plate assembly includes a cover plate body and an insulating member. The side of the cover plate body facing the receiving cavity is an inner wall, and the insulating member is connected to the inner wall. The electrode assembly is housed within the receiving cavity; An insulating film covers the electrode assembly, and the end of the insulating film has a connection area that connects to the insulating element; Wherein, along the thickness direction of the insulating component, the distance from the edge of the end of the insulating film to the inner wall is greater than zero, and the connection area between the connection region and the insulating component accounts for more than 50% of the area of ​​the connection region.

2. The single-cell battery as described in claim 1, characterized in that, Along the thickness direction of the insulating member, the connection area includes a first edge near the inner wall and a second edge away from the inner wall, and the insulating member includes a third edge near the inner wall and a fourth edge away from the inner wall; Along the thickness direction of the insulating element, the second edge of the connecting region is closer to the inner wall than the fourth edge of the insulating element; and / or, Along the thickness direction of the insulating element, the distance from the first edge of the connection area to the inner wall is greater than 0.5 mm.

3. The single-cell battery as described in claim 1, characterized in that, The insulating film includes a film body and a thickened portion. The thickened portion is located at the end and is stacked with the film body along the thickness direction of the insulating film to form a thickened region. The connecting region is at least partially located in the thickened region.

4. The single-cell battery as described in claim 3, characterized in that, The thickened area includes two or more layers of the membrane body, and the thickened portion is located on the side of the insulating membrane facing the insulating member; and / or, The ratio of the thickness of the thickened region to the thickness of the membrane body is 1.2-2.5; the thickness of the membrane body is 0.08mm-0.15mm, and the thickness of the thickened region is 0.1mm-0.2mm.

5. The single-cell battery as described in claim 4, characterized in that, Along the thickness direction of the insulating film, the thickened portion is a single film body, which is formed by folding the film body toward the insulating member, or by stacking multiple layers of the film body.

6. The single-cell battery as described in claim 5, characterized in that, The thickened area also includes an adhesive layer; When the thickened portion is a single layer of the film body, the adhesive layer is located between the film body and the thickened portion along the thickness direction of the insulating film. When the thickened portion is a multilayer membrane, the adhesive layer is located between the membrane body and the thickened portion along the thickness direction of the insulating film, and / or the adhesive layer is located between two adjacent membrane bodies in the thickened portion.

7. The single-cell battery as described in claim 3, characterized in that, Along the circumference of the insulating member, the end is connected to the insulating member, and the end includes an overlapping region and a non-overlapping region, both of which contain two layers of film body.

8. The single-cell battery as described in claim 3, characterized in that, Along the thickness direction of the insulating member, the connecting region includes a first edge near the inner wall and a second edge away from the inner wall; the insulating member includes a third edge near the inner wall and a fourth edge away from the inner wall; the thickened region includes a fifth edge near the inner wall and a sixth edge away from the inner wall. Along the thickness direction of the insulating member, the thickened region is located between the third and fourth edges of the insulating member, the connecting region is located between the fifth and sixth edges of the thickened region, and the distance from the second edge of the connecting region to the sixth edge of the thickened portion is ≥1.5mm.

9. The single-cell battery according to any one of claims 1-8, characterized in that, The connection area is thermally fused to the insulating component; and / or, The number of connection areas is multiple, and the multiple connection areas are arranged at intervals along the circumference of the insulating member.

10. The single-cell battery as described in claim 9, characterized in that, The insulating element includes a protrusion located on the side of the insulating element away from the inner wall, and the connecting area is at least partially thermally fused to the protrusion.

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