Battery cells and battery packs

Abstract

The present invention relates to the field of battery technology, and discloses a battery cell and a battery pack, including: a shell; an insulating film, a first window is provided, and the first window is arranged corresponding to the side of the shell; the width of the shell is W, the height of the shell is H, the two side edges and the bottom edge of the shell opposite to each other form a rounded structure, the width of the first window is w1, the height of the first window is h1, and 50%W≤w1≤W‑10, 50%H≤h1≤H‑5, 40%S1≤w1×h1≤90%S1 are satisfied, wherein S1=(W‑2×R1)×(H‑R3). The exposed part of the side of the shell of the present invention is directly in contact with the structural adhesive and bonded to the box of the battery pack, thereby improving the bonding strength between the battery cell and the box of the battery pack, and improving the life and safety of the battery pack; and, the insulating film is prevented from being separated from the shell, and the coating effect of the insulating film on the shell is not affected, thereby ensuring the safety of the battery cell.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to battery cells and battery packs. Background Art

[0002] The outside of the battery shell usually needs to be coated with an insulating film to prevent the metal shell of the battery cell from short-circuiting with the outside and play an insulating role. In addition, the insulating film can also prevent the battery cell shell from being worn and scratched, thereby protecting the battery cell shell. When assembling the battery cells to form a battery pack, the battery cells need to be bonded to the battery pack box (such as side panels, etc.) with structural adhesive. Since the battery cells are coated with an insulating film, the battery cells are bonded to the battery pack box through the insulating film, which not only reduces the bonding strength between the battery cells and the box, affecting the life and safety of the battery pack, but also, since the tensile strength and shear strength between the insulating film and the battery shell are low, during the operation of the battery pack, it is easy to cause the insulating film and the battery shell to separate, causing safety risks. Summary of the invention

[0003] In view of this, the present invention provides a battery cell and a battery pack to solve the problems in the prior art of low bonding strength between the battery cell and the battery pack case, and easy separation between the insulating film and the battery shell.

[0004] In a first aspect, the present invention provides a battery cell, comprising: a shell; an insulating film, which is coated on the outer side of the shell, the insulating film having a first window, and the first window is arranged corresponding to the side of the shell; the width of the shell is W, the height of the shell is H, two opposite side edges and a bottom edge of the side of the shell form a rounded structure, the radius of the rounded structure corresponding to the two opposite side edges of the side of the shell is R1, the radius of the rounded structure corresponding to the bottom edge of the side of the shell is R3, the width of the first window is w1, the height of the first window is h1, and 50%W≤w1≤W-10, 50%H≤h1≤H-5, 40%S1≤w1×h1≤90%S1 are satisfied, and S1=(W-2×R1)×(H-R3).

[0005] Beneficial effect: By opening a first window on the insulating film, the side of the shell is exposed through the first window. When the battery cells are assembled to form a battery pack, the exposed part of the side of the shell is directly in contact with the structural adhesive and bonded to the battery pack body, thereby improving the bonding strength between the battery cells and the battery pack body, thereby improving the life and safety of the battery pack; and avoiding separation of the insulating film and the shell, which will not affect the wrapping effect of the insulating film on the shell, thereby ensuring the safety of the battery cells.

[0006] In an optional embodiment, the insulating film is further provided with a second window, and the second window is arranged corresponding to the bottom surface of the shell; the length of the shell is L, and the four sides of the bottom surface of the shell form the rounded corner structure, the radius of the rounded corner structure corresponding to the four sides of the bottom surface of the shell is R2, the width of the second window is w2, and the length of the second window is l2, satisfying 50%W≤w2≤W-10, 50%L≤l2≤L-10, 50%S2≤w2×l2≤95%S2, wherein S2=(W-2×R2)×(L-2×R2).

[0007] Beneficial effect: By opening a second window on the insulating film, the bottom surface of the shell is exposed through the second window. When the battery cells are assembled to form a battery pack, the exposed part of the bottom surface of the shell is directly in contact with the structural adhesive and bonded to the battery pack body, thereby improving the bonding strength between the battery cells and the battery pack body, thereby improving the life and safety of the battery pack; and avoiding separation of the insulating film and the shell, which will not affect the wrapping effect of the insulating film on the shell, thereby ensuring the safety of the battery cells.

[0008] In an optional embodiment, the width W of the shell is in the range of 25 mm to 100 mm, the height H of the shell is in the range of 70 mm to 300 mm, and the length L of the shell is in the range of 120 mm to 500 mm.

[0009] In an optional embodiment, the battery cell further includes a cover plate, one side of the shell is provided with an opening, the opening is arranged opposite to the bottom surface of the shell, and the cover plate is connected to the shell and blocks the opening.

[0010] In an optional embodiment, a pole assembly is arranged on the cover plate, and the insulating film is folded from the side of the shell to the cover plate to form a folded edge, and the edge of the folded edge away from the side of the shell is spaced apart from the pole assembly.

[0011] Beneficial effect: the insulating film is folded onto the cover plate, thereby improving the firmness of the insulating film coating, and the folded edge folded onto the cover plate will not come into contact and interfere with the pole assembly, thereby avoiding affecting the pole assembly.

[0012] In an optional embodiment, the distance between the long side of the cover plate and the corresponding one side edge of the pole assembly is a1, the distance between the short side of the cover plate and the corresponding other side edge of the pole assembly is a2, and the width of the folded edge is a3, satisfying 2mm≤a3≤[min(a1, a2)-0.5]mm.

[0013] Beneficial effect: while ensuring the bonding firmness of the insulating film on the cover, it prevents the insulating film from sticking to the pole assembly and affecting the overall appearance of the cover.

[0014] In an optional embodiment, the distance a1 between the long side of the cover plate and the corresponding edge of one side of the pole assembly satisfies 2mm≤a1≤(W-5)mm, and the distance a2 between the short side of the cover plate and the corresponding edge of the other side of the pole assembly satisfies 3mm≤a2≤100mm.

[0015] In an optional embodiment, the peeling force of the insulating film is 2.5 N / cm to 8 N / cm; and / or the puncture resistance of the insulating film is not less than 150 N / mm.

[0016] In a second aspect, the present invention further provides a battery pack, comprising the above-mentioned battery cell and a box body, wherein the battery cell is disposed in the box body, and the side surface of the shell is bonded to the box body through the first opening.

[0017] In an optional embodiment, a plurality of the battery cells are arranged along the width direction of the battery cells, the box body includes a side plate, and a plurality of side surfaces of the shell body are bonded to the side plate through the first window. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 A schematic structural diagram of a battery cell according to an embodiment of the present invention at a first angle;

[0020] Figure 2 for Figure 1 A schematic structural diagram of a battery cell at a second angle shown;

[0021] Figure 3 for Figure 1 A schematic structural diagram of a side surface of a housing of a battery cell shown;

[0022] Figure 4 for Figure 3 The schematic structural diagram of the side surface of the shell when the insulating film of the battery cell is not provided with the first window;

[0023] Figure 5 for Figure 2A schematic structural diagram of the bottom surface of the housing of the battery cell shown;

[0024] Figure 6 for Figure 5 The schematic structural diagram of the bottom surface of the shell when the insulating film of the battery cell is not provided with the second window;

[0025] Figure 7 for Figure 1 A schematic diagram of the structure of the cover plate and the folded edge of the battery cell shown;

[0026] Figure 8 Schematic diagram of the structure of a battery pack according to an embodiment of the present invention.

[0027] Description of reference numerals:

[0028] 1. Shell; 2. Insulating film; 21. First window; 22. Second window; 23. Folded edge; 3. Cover plate; 4. Pole assembly; 5. Box body; 51. Side panel. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0030] Combine the following Figures 1 to 8 , describing an embodiment of the present invention.

[0031] According to an embodiment of the present invention, on the one hand, a battery cell is provided, comprising: a shell 1 and an insulating film 2. The insulating film 2 is coated on the outer side of the shell 1, and a first window 21 is provided on the insulating film 2, and the first window 21 is arranged corresponding to the side of the shell 1. The width of the shell 1 is W, the height of the shell 1 is H, the two opposite side edges and the bottom edge of the side of the shell 1 form a rounded structure, the radius of the rounded structure corresponding to the two opposite side edges of the side of the shell 1 is R1, the radius of the rounded structure corresponding to the bottom edge of the side of the shell 1 is R3, the width of the first window 21 is w1, the height of the first window 21 is h1, and 50%W≤w1≤W-10, 50%H≤h1≤H-5, 40%S1≤w1×h1≤90%S1 are satisfied, wherein S1=(W-2×R1)×(H-R3).

[0032] By opening a first window 21 on the insulating film 2, the side of the shell 1 is exposed through the first window 21. When the battery cells are assembled to form a battery pack, the exposed part of the side of the shell 1 is directly in contact with the structural adhesive and bonded to the battery pack case 5, thereby improving the bonding strength between the battery cells and the battery pack case 5, thereby improving the life and safety of the battery pack; and preventing the insulating film 2 from detaching from the shell 1, without affecting the coating effect of the insulating film 2 on the shell 1, thereby ensuring the safety of the battery cells.

[0033] It is worth mentioning that please refer to Figure 1 , Figure 3 and Figure 4 The above-mentioned “side surface of the housing 1” refers to a surface formed by the width direction and the height direction of the housing 1. The side surface of the housing 1 is a rectangular structure, and the first window 21 is also a rectangular structure.

[0034] It should be noted that the units of the width W of the shell 1, the height H of the shell 1, the radii R1 and R3 of the rounded corner structure, the width w1 of the first window 21 and the height h1 of the first window 21 are all mm. Correspondingly, the units of W-10 and H-5 are also mm, and the units of w1×h1 and S1 are all mm².

[0035] The following Pack vibration impact test is performed on battery cells with first windows 21 of different sizes after being bonded to the box body 5, and the test results of the embodiment and the comparative example are shown in Table 1 and Table 2. The embodiment refers to a battery cell with a first window 21 that meets the requirements of the embodiment, and correspondingly, the comparative example refers to a battery cell with a first window 21 that does not meet the requirements of the embodiment.

[0036] Table 1 Test results of Pack vibration impact test embodiment after the battery cells with first windows 21 of different sizes are bonded to the box body 5

[0037]

[0038] Table 2 Comparative test results of Pack vibration impact test after bonding battery cells with first windows 21 of different sizes to the box body 5

[0039]

[0040] In one embodiment, Figure 2 , Figure 5 and Figure 6As shown, the insulating film 2 is further provided with a second window 22, and the second window 22 is arranged corresponding to the bottom surface of the shell 1; the length of the shell 1 is L, and the four sides of the bottom surface of the shell 1 form a rounded structure, and the radius of the rounded structure corresponding to the four sides of the bottom surface of the shell 1 is R2, the width of the second window 22 is w2, and the length of the second window 22 is l2, satisfying 50%W≤w2≤W-10, 50%L≤l2≤L-10, 50%S2≤w2×l2≤95%S2, wherein, S2=(W-2×R2)×(L-2×R2).

[0041] By opening a second window 22 on the insulating film 2, the bottom surface of the shell 1 is exposed through the second window 22. When the battery cells are assembled to form a battery pack, the exposed portion of the bottom surface of the shell 1 is directly in contact with the structural adhesive and bonded to the battery pack case 5, thereby improving the bonding strength between the battery cells and the battery pack case 5, thereby improving the life and safety of the battery pack; and preventing the insulating film 2 from detaching from the shell 1, without affecting the coating effect of the insulating film 2 on the shell 1, thereby ensuring the safety of the battery cells.

[0042] It is worth noting that if Figure 2 , Figure 5 and Figure 6 As shown, the above-mentioned "bottom surface of the housing 1" refers to the surface formed by the length direction and the width direction of the housing 1. The bottom surface of the housing 1 is a rectangular structure, and the second window 22 is also a rectangular structure.

[0043] It should be noted that the units of the length L of the shell 1, the radius R2 of the rounded structure, the width w2 of the second window 22 and the length l2 of the second window 22 are all mm. Correspondingly, the unit of L-10 is also mm, and the units of w2×l2 and S2 are all mm².

[0044] The following Pack vibration impact test is performed on battery cells with second windows 22 of different sizes after being bonded to the box body 5, and the test results of the embodiment and the comparative example are shown in Table 3 and Table 4. The embodiment refers to the battery cell with the second window 22 that meets the requirements of the embodiment, and correspondingly, the comparative example refers to the battery cell with the second window 22 that does not meet the requirements of the embodiment.

[0045] Table 3 Test results of the Pack vibration impact test embodiment after the battery cells with second windows 22 of different sizes are bonded to the box body 5

[0046]

[0047] Table 4 Comparative test results of Pack vibration impact test after bonding battery cells with second windows 22 of different sizes to the box body 5

[0048]

[0049] In one embodiment, the width W of the shell 1 ranges from 25 mm to 100 mm, the height H of the shell 1 ranges from 70 mm to 300 mm, and the length L of the shell 1 ranges from 120 mm to 500 mm.

[0050] It is worth noting that the battery cell in this embodiment is a square shell battery.

[0051] In one embodiment, Figure 1 and Figure 7 As shown, the battery cell further includes a cover plate 3. One side of the shell 1 is provided with an opening, the opening is arranged opposite to the bottom surface of the shell 1, and the cover plate 3 is connected to the shell 1 and blocks the opening.

[0052] In one embodiment, Figure 1 and Figure 7 As shown, a pole assembly 4 is arranged on the cover plate 3, and the insulating film 2 is folded from the side of the housing 1 to the cover plate 3 to form a folded edge 23, and the edge of the folded edge 23 away from the side of the housing 1 is spaced from the pole assembly 4. Folding the insulating film 2 onto the cover plate 3 improves the firmness of the insulating film 2 coating, and the folded edge 23 folded onto the cover plate 3 will not contact and interfere with the pole assembly 4, thereby avoiding affecting the pole assembly 4.

[0053] In one embodiment, Figure 7 As shown, the distance between the long side of the cover plate 3 and the corresponding edge of one side of the pole assembly 4 is a1, the distance between the short side of the cover plate 3 and the corresponding edge of the other side of the pole assembly 4 is a2, and the width of the folded edge 23 is a3, which satisfies 2mm≤a3≤[min(a1, a2)-0.5]mm. While ensuring the bonding firmness of the insulating film 2 on the cover plate 3, the insulating film 2 is prevented from being attached to the pole assembly 4 and affecting the overall appearance of the cover plate 3.

[0054] It is worth noting that if the value of a3 is too small, the folded edge 23 of the insulating film 2 pasted on the cover plate 3 is prone to warping and the adhesion is poor; if the value of a3 is too large, the folded edge 23 is easy to stick to the pole assembly 4, affecting the overall appearance of the cover plate 3 and affecting the use of the pole assembly 4.

[0055] It should be noted that the distance a1 between the long side of the cover plate 3 and one side edge of the corresponding pole assembly 4, the distance a2 between the short side of the cover plate 3 and the other side edge of the corresponding pole assembly 4, and the width a3 of the folded edge 23 are all in mm.

[0056] It is worth noting that the edge of the pole assembly 4 is the outer edge of the upper plastic of the pole assembly 4 .

[0057] In one embodiment, the distance a1 between the long side of the cover plate 3 and the corresponding edge of one side of the pole assembly 4 satisfies 2mm≤a1≤(W-5)mm, and the distance a2 between the short side of the cover plate 3 and the corresponding edge of the other side of the pole assembly 4 satisfies 3mm≤a2≤100mm.

[0058] It is worth noting that if the value of a1 is too small, the space reserved for the folded edge 23 on the cover plate 3 is too small, and it is not convenient to stick the folded edge 23 on the cover plate 3; if the value of a1 is too large, the installation space of the pole assembly 4 is too small, which is not convenient for setting the pole assembly 4. If the value of a2 is too small, the space reserved for the folded edge 23 on the cover plate 3 is too small, and it is not convenient to stick the folded edge 23 on the cover plate 3; if the value of a2 is too large, the space occupied on the cover plate 3 is too large, which is not convenient for arranging other components (such as explosion-proof valves) on the cover plate 3.

[0059] The battery cells with different folding edge 23 widths are tested below, and the results of the embodiment and the comparative example are shown in Table 5. The embodiment refers to the battery cell with the folding edge 23 width that meets the requirements of the embodiment, and the comparative example refers to the battery cell with the folding edge 23 width that does not meet the requirements of the embodiment.

[0060] Table 5 Test results of battery cell embodiments and comparative examples with different widths of the folded edge 23

[0061]

[0062] In one embodiment, the peeling force of the insulating film 2 is 2.5 N / cm to 8 N / cm. By controlling the peeling force of the insulating film 2, the strength requirement of the insulating film 2 adhering to the surface of the housing 1 is met.

[0063] Battery cells with different peeling forces are examined below, and the results of the embodiment and the comparative example are shown in Table 6. The embodiment refers to a battery cell with a peeling force that meets the requirements of the embodiment, and the comparative example refers to a battery cell with a peeling force that does not meet the requirements of the embodiment.

[0064] Table 6 Test results of battery monomer examples and comparative examples with different peeling forces

[0065]

[0066] It can be seen from Table 6 that in Examples 1 to 12, the peeling force of the insulating film 2 is in the range of 2.5 N / cm to 8 N / cm. Therefore, the battery cell is left at room temperature for a week without any abnormality. The battery with poor insulating film 2 coating can be reworked relatively easily. After removing the insulating film 2, the residual glue area is within 5%, which meets the requirements.

[0067] It can be seen from Table 6 that in Comparative Example 1, the peeling force of the insulating film 2 is 2 N / cm, which is less than the 2.5 N / cm required in this embodiment. After the battery cell is left at room temperature for a week, the insulating film 2 is separated from the shell 1, which does not meet the requirements.

[0068] It can be seen from Table 6 that in Comparative Examples 2 and 3, the peeling force of the insulating film 2 is greater than 8N / cm required by this embodiment. The battery cells of Comparative Examples 2 and 3 were left at room temperature for one week without any abnormality. It is very difficult to rework the batteries with poor insulating film 2 coating. After peeling off the insulating film 2, the residual glue area is large, which does not meet the requirements.

[0069] It is worth noting that the peeling force detection process is to fix the shell 1, clamp the edge of the insulating film 2 with a chuck, fold the insulating film 2 180° on the shell 1, and then apply force to the insulating film 2 with the chuck to peel it off.

[0070] In one embodiment, the puncture resistance of the insulating film 2 is not less than 150 N / mm.

[0071] According to an embodiment of the present invention, on the other hand, a battery pack is provided, including the above-mentioned battery cell and a box body 5 , wherein the battery cell is disposed in the box body 5 , and the side surface of the housing 1 is bonded to the box body 5 through a first window 21 .

[0072] In one embodiment, Figure 8 As shown, a plurality of battery cells are arranged along the width direction of the battery cells, the box body 5 includes a side plate 51 , and the side surfaces of the plurality of shells 1 are bonded to the side plate 51 through the first opening 21 .

[0073] It is worth noting that the box body 5 also includes a bottom plate, and the bottom surfaces of the plurality of shells 1 are bonded to the bottom plate through the second windows 22 .

[0074] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A battery cell, characterized in that: include: case; An insulating film, covering the outer side of the shell, the insulating film is provided with a first window, and the first window is arranged corresponding to the side surface of the shell; The width of the shell is W, the height of the shell is H, two opposite side edges and a bottom edge of the shell form a rounded structure, the radius of the rounded structure corresponding to the two opposite side edges of the shell is R1, the radius of the rounded structure corresponding to the bottom edge of the shell is R3, the width of the first window is w1, the height of the first window is h1, and 50%W≤w1≤W-10, 50%H≤h1≤H-5, 40%S1≤w1×h1≤90%S1 is satisfied, wherein S1=(W-2×R1)×(H-R3); The battery cell further comprises a cover plate, one side of the shell is provided with an opening, the opening is arranged opposite to the bottom surface of the shell, and the cover plate is connected to the shell and blocks the opening; The cover plate is provided with a pole assembly, the insulating film is folded from the side of the shell to the cover plate to form a folded edge, and the edge of the folded edge away from the side of the shell is spaced apart from the pole assembly; The distance between the long side of the cover plate and the corresponding edge of one side of the pole assembly is a1, the distance between the short side of the cover plate and the corresponding edge of the other side of the pole assembly is a2, and the width of the folded edge is a3, satisfying 2mm≤a3≤[min(a1,a2)-0.5]mm; The insulating film is further provided with a second window, and the second window is arranged corresponding to the bottom surface of the shell; The length of the shell is L, the four sides of the bottom surface of the shell form the rounded corner structure, the radius of the rounded corner structure corresponding to the four sides of the bottom surface of the shell is R2, the width of the second window is w2, the length of the second window is l2, and 50%W≤w2≤W-10, 50%L≤l2≤L-10, 50%S2≤w2×l2≤95%S2 is satisfied, wherein S2=(W-2×R2)×(L-2×R2); The width W of the shell is in the range of 25 mm to 100 mm, the height H of the shell is in the range of 70 mm to 300 mm, and the length L of the shell is in the range of 120 mm to 500 mm; The peeling force of the insulating film is 2.5N / cm to 8N / cm; The puncture resistance of the insulating film is not less than 150N / mm.

2. The battery cell according to claim 1, characterized in that: The distance a1 between the long side of the cover plate and the corresponding edge of one side of the pole assembly satisfies 2mm≤a1≤(W-5)mm, and the distance a2 between the short side of the cover plate and the corresponding edge of the other side of the pole assembly satisfies 3mm≤a2≤100mm.

3. A battery pack, characterized in that: It comprises the battery cell and box body as claimed in claim 1 or 2, wherein the battery cell is arranged in the box body, and the side surface of the shell is bonded to the box body through the first window.

4. The battery pack according to claim 3, characterized in that: A plurality of battery cells are arranged along the width direction of the battery cells, the box body comprises a side plate, and a plurality of side surfaces of the shell body are bonded to the side plate through the first opening.

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