Battery pack

Abstract

The utility model discloses a battery pack which comprises a box body, a battery pack and a fixing adhesive layer, the box body comprises a bottom plate and an enclosure frame, an accommodating cavity is formed between the bottom plate and the enclosure frame, the battery pack is arranged in the accommodating cavity and is fixed on the bottom plate through the fixing adhesive layer, and the battery pack comprises single batteries and an insulating film. Each single battery comprises a first end surface, a second end surface, a first side surface, a second side surface, a third side surface and a fourth side surface, the insulating film comprises a starting part and an ending part, the insulating film covers the first side surface, the second side surface, the third side surface and the fourth side surface, the starting part and the ending part are overlapped on the first side surface to form an overlapping part, and the overlapping part is arranged along the first direction. The size of the overlapping portion is L1 mm, the size of the first side face is L2 mm, the thickness of the insulating film is a mm, and a * (L1 / L2) is larger than or equal to 0.028 and smaller than or equal to 0.12. According to the utility model, the stability of the battery pack adhered in the box body can be ensured, and glue overflow is not easy to cause.

Description

Technical Field

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

[0002] The battery pack includes a housing and a battery pack. The battery pack is fixed to the bottom wall of the housing by a fixing adhesive layer. The battery pack is composed of multiple individual cells stacked together. In order to protect the individual cells, an insulating film is wrapped around the outer surface of the individual cells. The insulating film includes a starting part and a closing part. The starting part is attached to the outer surface of the individual cell, and then the closing part is stacked on the side of the starting part away from the individual cell after wrapping around the individual cell, so as to wrap the individual cell.

[0003] Because the battery pack design has requirements for both weight and size, there are also requirements for the amount of adhesive used to fix the adhesive layer and the installation height of the battery pack. As a result, if the insulating film is thick, the fixing adhesive layer will be excessively squeezed during battery pack installation, resulting in serious adhesive overflow. If the insulating film is thin, the fixing adhesive layer may not be able to completely cover the bonding surface of the insulating film of the individual cells during battery pack installation, affecting the bonding strength. Utility Model Content

[0004] The purpose of this invention is to provide a battery pack that ensures the battery pack is securely attached to the casing and is less prone to adhesive overflow.

[0005] To solve the above-mentioned technical problems, this utility model provides the following technical solution:

[0006] A battery pack includes a housing, a battery assembly, and a fixing adhesive layer. The housing includes a base plate and a frame surrounding the base plate, forming a receiving cavity between the base plate and the frame. The fixing adhesive layer is laid on the base plate. The battery assembly is placed within the receiving cavity and fixed to the base plate by the fixing adhesive layer. The battery assembly includes individual cells and an insulating film. Each individual cell includes a first end face and a second end face disposed opposite to each other, and a first side face, a second side face, a third side face, and a fourth side face located between the first end face and the second end face and sequentially connected. The first side face and the third side face are disposed opposite to each other, and the second side face and the fourth side face are disposed opposite to each other. The insulating film has two ends... The regions are the starting part and the ending part, respectively. The insulating film covers the first side, the second side, the third side and the fourth side. The starting part is attached to the outside of the first side, and the ending part is attached to the side of the starting part opposite to the first side. The overlapping area of ​​the starting part and the ending part is the overlapping part. The single cell is located on the side of the first side and is bonded to the base plate by the fixing adhesive layer. The direction from the second side to the fourth side is the first direction. In the first direction, the size of the overlapping part is L1mm, the size of the first side is L2mm, and the thickness of the insulating film is amm, where 0.028≤a*(L1 / L2)≤0.12.

[0007] Compared with the prior art, the battery pack of this utility model has the following advantages:

[0008] In this invention, the insulating film wraps around the individual battery cell, and the starting and ending portions of the insulating film are located on the first side of the individual battery cell. Therefore, when bonding the first side of the individual battery cell to the fixing adhesive layer, the ending portion of the insulating film can be prevented from lifting, and the stability of the individual battery cell bonded to the base plate can be ensured. At the same time, since the amount of fixing adhesive layer and the installation height of the battery pack in the box are required after the battery pack design is completed, under this premise, when the thickness of the insulating film is too thick, it is easy to over-compress the fixing adhesive layer and cause glue overflow. Therefore, the size of the overlapping portion needs to be reduced. When the thickness of the insulating film is too thin, it may affect the bonding area between the individual battery cell and the fixing adhesive layer. Therefore, the size of the overlapping portion needs to be increased. Therefore, 0.028≤a*(L1 / L2)≤0.12 is maintained to ensure that the battery pack can be stably bonded to the base plate without causing glue overflow. Attached Figure Description

[0009] Figure 1 This is a perspective view of the overall structure of an embodiment of the present utility model;

[0010] Figure 2 This is another perspective view of the overall structure of an embodiment of the present utility model;

[0011] Figure 3 This is a cross-sectional view of the overall structure of an embodiment of this utility model;

[0012] Figure 4 yes Figure 3 Enlarged view of point A in the image;

[0013] Figure 5 This is a schematic diagram of a single battery cell and an insulating film according to an embodiment of the present invention;

[0014] Figure 6 This is an exploded view of a single cell battery and an insulating film according to an embodiment of the present invention;

[0015] Figure 7 yes Figure 6 Enlarged view of point B in the image;

[0016] Figure 8 This is another exploded view of the single cell battery and insulating film according to an embodiment of the present invention;

[0017] Figure 9 This is a front view of a single battery cell according to an embodiment of the present invention;

[0018] Figure 10 yes Figure 9 Enlarged view of point C in the image;

[0019] Figure 11 This is a schematic diagram of the weld seam of a single battery cell according to an embodiment of the present invention;

[0020] Figure 12 This is a bottom view of a single battery cell according to an embodiment of the present invention.

[0021] In the diagram, 1. Box body; 11. Base plate; 12. Frame; 13. Receiving cavity; 2. Battery pack; 21. Individual battery cell; 211. First end face; 212. Second end face; 213. First side face; 214. Second side face; 215. Third side face; 216. Fourth side face; 217. Shell; 218. Cover plate; 22. Insulating film; 221. Starting part; 222. Ending part; 223. Overlapping part; 3. Fixing adhesive layer; 4. Weld. Detailed Implementation

[0022] The specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this utility model, but are not intended to limit its scope.

[0023] In the description of this utility model, it should be understood that the term "comprising" as used in this specification means the presence of the stated features, integers, steps, operations, parts, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, parts, components, and / or groups thereof. It should be understood that when we say a part is "connected" to another part, it can be directly connected to the other part, or there may be intermediate parts. The term "and / or" as used herein includes all or any unit and all combinations of one or more associated listed items.

[0024] like Figures 1 to 12 As shown, this utility model relates to a battery pack, including a housing 1, a battery pack 2, and a fixing adhesive layer 3. The housing 1 includes a base plate 11 and a frame 12 surrounding the base plate 11. A receiving cavity 13 is formed between the base plate 11 and the frame 12. The fixing adhesive layer 3 is laid on the base plate 11. The battery pack 2 is placed in the receiving cavity 13 and fixed to the base plate 11 by the fixing adhesive layer 3. The battery pack 2 includes a single battery cell 21 and an insulating film 22. The single battery cell 21 includes a first end face 211 and a second end face 212 arranged opposite to each other, and a first side face 213, a second side face 214, a third side face 215, and a fourth side face 216 located between the first end face 211 and the second end face 212 and connected in sequence. The first side face 213 and the third side face 215 are arranged opposite to each other, and the second side face 214 and the fourth side face 216 are arranged opposite to each other. The regions at both ends of the insulating film 22 are the starting portions. 221 and 222, the insulating film 22 covers the first side 213, the second side 214, the third side 215 and the fourth side 216, the starting part 221 is attached to the outside of the first side 213, and the ending part 222 is attached to the side of the starting part 221 opposite to the first side 213. The overlapping area of ​​the starting part 221 and the ending part 222 is the overlapping part 223. The single cell 21 is located on one side of the first side 213. The side is bonded to the base plate 11 by the fixing adhesive layer 3. The direction from the second side 214 to the fourth side 216 is the first direction. In the first direction, the size of the overlapping part 223 is L1mm, the size of the first side 213 is L2mm, and the thickness of the insulating film 22 is amm. Wherein, 0.028≤a*(L1 / L2)≤0.12, and the value of a*(L1 / L2) can be 0.04, 0.06, 0.08 or 0.1.

[0025] In this invention, the insulating film 22 wraps around the individual battery 21, and the starting portion 221 and the ending portion 222 of the insulating film 22 are located on the first side 213 of the individual battery 21. Therefore, when the first side 213 of the individual battery 21 is bonded to the fixing adhesive layer 3, the ending portion 222 of the insulating film 22 can be prevented from lifting, and the stability of the individual battery 21 bonded to the base plate 11 can be ensured. At the same time, since the amount of fixing adhesive layer 3 and the battery pack 2 are in the housing after the battery pack design is completed, the amount of the battery pack 2 is also determined. There are requirements for the installation height within 1. Under this premise, when the thickness of the insulating film 22 is too thick, it is easy to over-compress the fixing adhesive layer 3, causing adhesive overflow. Therefore, it is necessary to reduce the size of the overlapping part 223. When the thickness of the insulating film 22 is too thin, it may affect the bonding area between the single cell 21 and the fixing adhesive layer 3. Therefore, it is necessary to increase the size of the overlapping part 223. Thus, keep 0.028≤a*(L1 / L2)≤0.12 so that the battery pack 2 can be stably bonded to the base plate 11 without causing adhesive overflow.

[0026] It should be explained that the region at one end of the insulating film 22 is the starting portion 221, and the region at the other end of the insulating film 22 is the ending portion 222. When the insulating film 22 covers the single cell 21, the starting portion 221 of the insulating film 22 is first attached to the first side 213. Then, the ending portion 222 of the insulating film 22 passes around the second side 214, the third side 215, and the fourth side 216 in sequence, and finally attaches to the side of the starting portion 221 on the first side 213 that is opposite to the first side 213. Furthermore, the region where the starting portion 221 and the ending portion 222 overlap is the overlapping portion 223.

[0027] In some embodiments, 4mm≤L1≤40mm, 8mm≤L2≤80mm. The value of L1 can be 8mm, 13mm, 18mm, 22mm, 29mm, 33mm or 38mm, and the value of L2 can be 15mm, 25mm, 35mm, 45mm, 65mm or 75mm.

[0028] In some embodiments, 0.05 ≤ L1 / L2 ≤ 0.95. The value of L1 / L2 can be 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8 or 0.9.

[0029] In some embodiments, 0.05mm ≤ a ≤ 0.5mm. The value of a can be 0.1mm, 0.2mm, 0.3mm, 0.4mm or 0.45mm.

[0030] In some embodiments, 0.04 ≤ a*(L1 / L2) ≤ 0.11.

[0031] In this embodiment, the thickness of the fixing adhesive layer 3 is c mm, where 0.3 mm ≤ c ≤ 3 mm, 0.05 mm ≤ a ≤ 0.2 mm, and the value of c can be 0.6 mm, 0.9 mm, 1.2 mm, 1.8 mm, 2.2 mm, 2.6 mm, or 2.8 mm.

[0032] When the insulating film 22 is thicker, its thermal conductivity will be poorer. Therefore, the thickness of the fixing adhesive layer 3 needs to be smaller to facilitate the heat dissipation of the individual battery 21. When the insulating film 22 is thinner, its thermal conductivity will be better. In this case, the thickness of the fixing adhesive layer 3 can be appropriately increased to improve the bonding strength to the battery pack 2. Therefore, keep 0.3mm≤c≤3mm and 0.05mm≤a≤0.2mm to meet the bonding strength requirements and thermal conductivity requirements of the battery pack 2.

[0033] In this embodiment, the single battery cell 21 includes a housing 217 and a cover plate 218. The housing 217 has openings at both ends. There are two cover plates 218, which are respectively covered at the openings at both ends of the housing 217 and respectively form a first end face 211 and a second end face 212. The four sides of the housing 217 are respectively a first side face 213, a second side face 214, a third side face 215 and a fourth side face 216. The housing 217 has a weld seam 4 at the first side face 213 in the direction from the first end face 211 to the second end face 212.

[0034] When manufacturing the housing 217, the two ends of the sheet structure are welded together to form the housing 217. At this time, a weld 4 will be formed on one side of the housing 217. The weld 4 is located on the first side 213 of the housing 217, and the first side 213 of the housing 217 is bonded to the fixing adhesive layer 3. The fixing adhesive layer 3 can be used to enhance the strength at the weld 4, thereby improving the stability of the single cell 21 structure.

[0035] In one embodiment, the orthographic projection of the overlapping portion 223 on the first side surface 213 does not overlap with the orthographic projection of the weld 4 on the first side surface 213. In this case, 0.05≤a*(L1 / L2)≤0.12 is maintained.

[0036] Since the weld 4 also protrudes beyond the first side 213, when the overlapping part 223 covers the weld 4, the overlapping part 223 will protrude too much beyond the first side 213, resulting in severe glue overflow after being bonded to the fixing adhesive layer 3.

[0037] In another embodiment, the orthographic projection of the overlapping portion 223 on the first side surface 213 overlaps with the orthographic projection of the weld 4 on the first side surface 213, in which case 0.028≤a*(L1 / L2)≤0.1 is maintained.

[0038] Because there are many burrs at weld 4, when the overlapping part 223 covers weld 4, it can form a double layer of protection, preventing the insulating film 22 from being punctured by the burrs and reducing the risk of insulation failure.

[0039] Combination Figure 12 As shown, in this embodiment, in the direction from the first end face 211 to the second end face 212, the size of the insulating film 22 is L3mm, and the size of the single cell 21 is L4mm, wherein 0.6≤L3 / L4≤1, 0.05≤a*(L1 / L2)≤0.12, and the value of L3 / L4 can be 0.65, 0.7, 0.75, 0.8, 0.85 or 0.9.

[0040] When L3 / L4 is small, the individual battery 21 is partially exposed outside the insulating film 22. When the exposed part of the individual battery 21 is bonded to the fixing adhesive layer 3, the bonding strength is also better. Therefore, the values ​​of a and L1 / L2 can be smaller, which can enhance the stability of the battery pack 2 bonded inside the housing 1. When L3 / L4 is large, the exposed part of the individual battery 21 is smaller, and the bonding strength of the individual battery 21 is also weaker. Therefore, the values ​​of a and L1 / L2 need to be larger. Thus, keeping 0.05≤a*(L1 / L2)≤0.12 is beneficial to improving the stability of the battery pack 2 bonded inside the housing 1.

[0041] In this embodiment, the insulating film 22 is made of PP, PE, PET or PC.

[0042] In one embodiment, the insulating film 22 is thermally bonded to the outside of the single cell 21.

[0043] That is, the insulating film 22 covers and is heat-fused to the outside of the single cell 21, and the tail portion 222 of the insulating film 22 is heat-fused to the side of the starting portion 221 of the insulating film 22 facing away from the single cell 21, so as to enhance the stability of the insulating film 22 outside the single cell 21.

[0044] In another embodiment, the starting portion 221 of the insulating film 22 is thermally bonded to the outside of the first side surface 213, and the ending portion 222 of the insulating film 22 is thermally bonded to the side of the starting portion 221 of the insulating film 22 that is opposite to the first side surface 213.

[0045] That is, the insulating film 22 is only thermally bonded to the first side 213 of the single cell 21 with the starting part 221, and then the ending part 222 of the insulating film 22 is thermally bonded to the side of the starting part 221 of the insulating film 22 that is opposite to the first side 213. The area of ​​the insulating film 22 between the starting part 221 and the ending part 222 is tightly wrapped around the single cell 21, so that the insulating film 22 can also cover the outside of the single cell 21.

[0046] In other embodiments, the starting portion 221 of the insulating film 22 is attached to the first side surface 213. After the insulating film 22 is wrapped around the second side surface 214, the third side surface 215 and the fourth side surface 216, the insulating film 22 is pulled taut, and the ending portion 222 of the insulating film 22 is heat-fused to the side of the starting portion 221 that is opposite to the first side surface 213, so that the insulating film 22 is tightly wrapped around the single cell 21.

[0047] In this embodiment, the areas of the second side 214 and the fourth side 216 are both larger than the area of ​​the first side 213.

[0048] Specifically, the first side 213 and the third side 215 have the same area, the second side 214 and the fourth side 216 have the same area, and the areas of the second side 214 and the fourth side 216 are both larger than the area of ​​the first side 213. Thus, the first side 213 of the single cell 21 is bonded to the base plate 11 by the fixing adhesive layer 3, which can improve the density of the battery pack 2 arrangement.

[0049] In this embodiment, the first end face 211 and the second end face 212 can be either planar or curved, and the areas of the first side face 213, the second side face 214, the third side face 215 and the fourth side face 216 are all larger than the areas of the first end face 211 and the second end face 212.

[0050] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present utility model, and these improvements and substitutions should also be considered within the protection scope of the present utility model.

Claims

1. A battery pack, characterized in that, The battery pack includes a housing, a battery assembly, and a fixing adhesive layer. The housing includes a base plate and a frame surrounding the base plate, forming a cavity between the base plate and the frame. The fixing adhesive layer is laid on the base plate, and the battery assembly is placed within the cavity and fixed to the base plate by the fixing adhesive layer. The battery assembly includes individual cells and an insulating film. Each individual cell includes a first end face and a second end face disposed opposite to each other, and a first side face, a second side face, a third side face, and a fourth side face located between the first end face and the second end face and sequentially connected. The first side face and the third side face are disposed opposite to each other, and the second side face and the fourth side face are disposed opposite to each other. The insulating film has regions at both ends... The components are a starting part and a ending part. The insulating film covers the first side, the second side, the third side, and the fourth side. The starting part is attached to the outside of the first side, and the ending part is attached to the side of the starting part opposite to the first side. The overlapping area of ​​the starting part and the ending part is called the overlapping part. The single cell is located on the side of the first side and is bonded to the base plate by the fixing adhesive layer. The direction from the second side to the fourth side is the first direction. In the first direction, the size of the overlapping part is L1mm, the size of the first side is L2mm, and the thickness of the insulating film is amm, where 0.028≤a*(L1 / L2)≤0.

12.

2. The battery pack according to claim 1, characterized in that, 4mm≤L1≤40mm, 8mm≤L2≤80mm.

3. The battery pack according to claim 1, characterized in that, 0.05≤L1 / L2≤0.

95.

4. The battery pack according to claim 1, characterized in that, 0.05mm≤a≤0.5mm.

5. The battery pack according to claim 1, characterized in that, 0.04≤a*(L1 / L2)≤0.

11.

6. The battery pack according to claim 1, characterized in that, The thickness of the fixing adhesive layer is c mm, where 0.3 mm ≤ c ≤ 3 mm and 0.05 mm ≤ a ≤ 0.2 mm.

7. The battery pack according to claim 1, characterized in that, The single battery includes a casing and a cover plate. The casing has openings at both ends. There are two cover plates, which are respectively covered at the openings at both ends of the casing and respectively form a first end face and a second end face. The four sides of the casing are respectively a first side face, a second side face, a third side face, and a fourth side face. The casing has a weld seam on the first side face from the first end face to the second end face.

8. The battery pack according to claim 7, characterized in that, The orthographic projection of the overlapping portion on the first side surface does not overlap with the orthographic projection of the weld on the first side surface, and 0.05≤a*(L1 / L2)≤0.

12.

9. The battery pack according to claim 7, characterized in that, The orthographic projection of the overlapping portion on the first side surface overlaps with the orthographic projection of the weld on the first side surface, and 0.028≤a*(L1 / L2)≤0.

1.

10. The battery pack according to claim 1, characterized in that, In the direction from the first end face to the second end face, the size of the insulating film is L3mm, and the size of the single cell is L4mm, wherein 0.6≤L3 / L4≤1, 0.05≤a*(L1 / L2)≤0.

12.

11. The battery pack according to claim 1, characterized in that, The areas of the second side and the fourth side are both larger than the area of ​​the first side.

Images