Inverted battery cell and battery pack

Abstract

The present invention relates to the technical field of secondary batteries, and discloses an inverted battery cell and a battery pack, the inverted battery cell comprises: a housing having an opening, the housing comprising a first wall; the battery cell cover plate is connected with the shell and blocks the opening so as to define a packaging space; the pole group body is arranged in the packaging space; the height of the inverted battery cell is H0, the height of the shell is H, the height of the pole group body is h, the thickness of the first wall is S, the distance from the top of the pole group body to the first wall is T1, the thickness of the battery cell cover plate is A, and h / H is larger than or equal to 0.83 and smaller than or equal to 0.96. By reasonably limiting the ratio of the height of the pole group body to the height of the shell, the gap between the pole group body and the first wall is prevented from being too large, the shaking space of the pole group body is reduced, and the risk after the inverted battery cell is shaken is reduced; the gap between the pole group body and the first wall is prevented from being too small, and the risk that the contact position of the pole group body and the first wall is damaged to separate lithium is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of secondary batteries, and in particular to an inverted battery cell and a battery pack. Background Art

[0002] Inverted cell technology is a new technology that has resulted in an inverted cell. In contrast, upright cell technology places the cell in a conventional upward position, with the positive and negative poles aligned with those of the battery pack. The advantage of this technology is that the cell structure is more stable, making it less susceptible to safety issues such as short circuits.

[0003] However, the assembly design of the electrode group and the shell of the existing inverted battery cell is unreasonable, which affects the performance, safety and stability of the battery cell. Summary of the Invention

[0004] In view of this, the present invention provides an inverted battery cell and a battery pack to solve the problems of unreasonable assembly design of existing inverted battery cells and poor battery cell performance and safety and stability.

[0005] In a first aspect, the present invention provides an inverted battery cell, comprising: a shell having an opening, the shell comprising a first wall, the first wall being arranged opposite to the opening; a battery cell cover plate being connected to the shell and sealing the opening to enclose and form a packaging space; a pole group body being arranged in the packaging space, the pole group body abutting against the battery cell cover plate; the height of the inverted battery cell is H0, the height of the shell is H, the height of the pole group body is h, the thickness of the first wall is S, the distance from the top of the pole group body to the first wall is T1, and the thickness of the battery cell cover plate is A, satisfying h=H0-T1-AS, 0.83≤h / H≤0.96.

[0006] Beneficial effects: By reasonably limiting the ratio of the height of the electrode group body to the height of the shell, the gap between the electrode group body and the first wall is prevented from being too large, the shaking space of the electrode group body is reduced, and the risk of the inverted battery cell being shaken is reduced; at the same time, the gap between the electrode group body and the first wall is prevented from being too small, and the risk of damage and lithium deposition at the contact position between the electrode group body and the first wall is reduced.

[0007] In an optional embodiment, the battery cell cover includes an insulating part, a cover body and a pole, the insulating part is arranged on the inner surface of the cover body, the pole passes through the cover body and protrudes from the outer surface of the cover body, the height of the insulating part is Z, the thickness of the cover body is Y, and the height of the pole protruding from the outer surface of the cover body is C, satisfying A=Z+Y+C.

[0008] In an optional embodiment, the bottom surface of the cover plate body is flush with the plane where the opening is located, and the height of the pole group body is h=H-T1-ZYS.

[0009] Beneficial effect: The bottom surface of the cover body is flush with the plane of the opening, which ensures the connection strength between the cover body and the shell while increasing the usable space of the electrode group body in the packaging space, thereby increasing the storage energy of the inverted battery cell.

[0010] In an optional embodiment, the height of the insulating member is Z, which satisfies 2.5 mm ≤ Z ≤ 8 mm.

[0011] In an optional embodiment, the thickness of the cover plate body is Y, satisfying 1.5 mm ≤ Y ≤ 4 mm.

[0012] In an optional embodiment, the thickness of the first wall is S, satisfying 1mm≤S≤2mm.

[0013] Beneficial effect: By limiting the thickness of the first wall, the first wall is prevented from being damaged due to being too thin. At the same time, the proportion of the first wall in the height direction of the shell is reduced, and the usable space of the electrode group body in the packaging space is increased, thereby increasing the storage energy of the inverted battery cell.

[0014] In an optional embodiment, the width of the shell is W, and the shell also includes a second wall, the thickness of the second wall is M, the distance between the second wall and the corresponding first side surface of the pole group body is T2, and the width of the pole group body is w, satisfying w=W-2×T2-2×M, and satisfying 0.86≤w / W≤0.93.

[0015] Beneficial effects: By reasonably limiting the ratio of the width of the pole group body to the width of the shell, the gap between the pole group body and the second wall is prevented from being too large, the shaking space of the pole group body is reduced, and the risk of the inverted battery cell being shaken is reduced; at the same time, the gap between the pole group body and the second wall is prevented from being too small, the expansion space of the pole group body is guaranteed, and the second wall is prevented from being squeezed and bulged outward by the pole group body.

[0016] In an optional embodiment, the length of the shell is L, and the shell also includes a third wall, the thickness of the third wall is B, the distance between the third wall and the corresponding second side of the pole group body is T3, and the length of the pole group body is l, satisfying l=L-2×T3-2×B, and satisfying 0.96≤l / L≤0.99.

[0017] Beneficial effects: By reasonably limiting the ratio of the thickness of the electrode group body to the thickness of the shell, the gap between the electrode group body and the third wall is prevented from being too large, the shaking space of the electrode group body is reduced, and the risk of the inverted battery cell being shaken is reduced; at the same time, the gap between the electrode group body and the third wall is prevented from being too small, avoiding the electrode group body from scratching the third wall when entering the shell.

[0018] In an optional embodiment, the difference between the thickness of the third wall and the thickness of the second wall is X, satisfying X=BM, and satisfying 0.1mm≤X≤0.25mm.

[0019] In a second aspect, the present invention further provides a battery pack comprising the above-mentioned inverted battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 Schematic diagram of the structure of an inverted battery cell along the length direction according to an embodiment of the present invention;

[0022] Figure 2 for Figure 1 A partial enlarged schematic diagram of point A in the middle;

[0023] Figure 3 Schematic diagram of the structure of an inverted battery cell along the width direction according to an embodiment of the present invention;

[0024] Figure 4 for Figure 3 A partial enlarged schematic diagram of point B in the middle;

[0025] Figure 5 Schematic diagram of the structure of the shell of an embodiment of the present invention.

[0026] Description of reference numerals:

[0027] 10. Shell; 11. First wall; 12. Second wall; 13. Third wall; 20. Cell cover; 21. Insulator; 22. Cover body; 23. Pole; 30. Pole group body; 31. First side surface; 32. Second side surface. DETAILED DESCRIPTION

[0028] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying 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 making creative efforts shall fall within the scope of protection of the present invention.

[0029] The following combination Figures 1 to 5 , describing embodiments of the present invention.

[0030] According to an embodiment of the present invention, on the one hand, an inverted battery cell is provided, comprising: a shell 10 having an opening, the shell 10 comprising a first wall 11, the first wall 11 being arranged opposite to the opening; a battery cell cover 20 being connected to the shell 10 and sealing the opening to enclose a packaging space; a pole group body 30 being arranged in the packaging space, the pole group body 30 being in contact with the battery cell cover 20; the height of the inverted battery cell is H0, the height of the shell 10 is H, the height of the pole group body 30 is h, the thickness of the first wall 11 is S, the distance from the top of the pole group body 30 to the first wall 11 is T1, and the thickness of the battery cell cover 20 is A, satisfying h=H0-T1-AS, 0.83≤h / H≤0.96.

[0031] By using the inverted battery cell of this embodiment, the ratio of the height of the electrode group body 30 to the height of the shell 10 is reasonably limited, so as to prevent the gap between the electrode group body 30 and the first wall 11 from being too large, reduce the shaking space of the electrode group body 30, and reduce the risk of the inverted battery cell being shaken; at the same time, the gap between the electrode group body 30 and the first wall 11 is prevented from being too small, thereby reducing the risk of damage and lithium deposition at the contact position between the electrode group body 30 and the first wall 11.

[0032] It should be noted that when h / H is less than 0.83, the gap between the electrode group body 30 and the first wall 11 is too large, and the shaking space of the electrode group body 30 is too large. When the battery cell is vibrated or shaken, the electrode group body 30 also shakes, causing damage to its internal structure, affecting the performance of the inverted battery cell; when h / H is greater than 0.96, the gap between the electrode group body 30 and the first wall 11 is too small, and the electrode group body 30 is prone to collision and contact with the first wall 11, and the electrode group body 30 is prone to damage and lithium deposition.

[0033] In one embodiment, the battery cell cover 20 includes an insulating member 21, a cover body 22 and a pole 23. The insulating member 21 is arranged on the inner surface of the cover body 22, and the pole 23 passes through the cover body 22 and protrudes from the outer surface of the cover body 22. The height of the insulating member 21 is Z, the thickness of the cover body 22 is Y, and the height of the pole 23 protruding from the outer surface of the cover body 22 is C, satisfying A=Z+Y+C.

[0034] Specifically, the height of the pole group body 30 is h=H0-T1-ZYCS.

[0035] Specifically, the insulating member 21 is made of lower plastic, and the cover plate body 22 is made of a plain aluminum plate.

[0036] In one embodiment, the bottom surface of the cover body 22 is flush with the plane of the opening, and the height of the electrode assembly body 30 is h = H - T1 - ZYS. This flushing of the bottom surface of the cover body 22 with the plane of the opening ensures the connection strength between the cover body 22 and the housing 10 while increasing the usable space of the electrode assembly body 30 within the packaging space, thereby increasing the stored energy of the inverted battery cell.

[0037] It should be noted that, in other alternative embodiments, the bottom surface of the cover body 22 may also protrude from the plane where the opening is located; or, the bottom surface of the cover body 22 may also be arranged inside the packaging space.

[0038] In one embodiment, the height of the insulating member 21 is Z, which satisfies 2.5 mm ≤ Z ≤ 8 mm.

[0039] In one embodiment, the thickness of the cover plate body 22 is Y, which satisfies 1.5 mm≤Y≤4 mm.

[0040] In one embodiment, the thickness of the first wall 11 is S, satisfying 1 mm ≤ S ≤ 2 mm. By limiting the thickness of the first wall 11, the first wall 11 is prevented from being too thin and damaged. At the same time, the height of the first wall 11 relative to the housing 10 is reduced, increasing the usable space of the electrode assembly body 30 within the packaging space, thereby increasing the stored energy of the inverted battery cell.

[0041] It should be noted that when the thickness S of the first wall 11 is less than 1 mm, the first wall 11 is relatively thin and easily damaged after contact with the electrode assembly body 30. When the thickness S of the first wall 11 is greater than 2 mm, the hardness of the housing 10 is improved by the first wall 11, but the excessive thickness of the first wall 11 affects the usable space within the housing 10. Therefore, the thickness of the first wall 11 is limited.

[0042] In one embodiment, the width of the housing 10 is W, and the housing 10 further includes a second wall 12, the thickness of the second wall 12 is M, the distance between the second wall 12 and the first side surface 31 of the corresponding electrode assembly body 30 is T2, and the width of the electrode assembly body 30 is w, satisfying w = W-2×T2-2×M, and satisfying 0.86≤w / W≤0.93. By reasonably limiting the ratio of the width of the electrode assembly body 30 to the width of the housing 10, the gap between the electrode assembly body 30 and the second wall 12 is prevented from being too large, the shaking space of the electrode assembly body 30 is reduced, and the risk of inverted battery cells being shaken is reduced; at the same time, the gap between the electrode assembly body 30 and the second wall 12 is prevented from being too small, ensuring expansion space for the electrode assembly body 30 and preventing the second wall 12 from being squeezed and bulged by the electrode assembly body 30.

[0043] It should be noted that when w / W is less than 0.86, the gap between the electrode assembly body 30 and the second wall 12 is too large, allowing the electrode assembly body 30 to sway excessively. When the battery cell is vibrated or shaken, the electrode assembly body 30 also shakes, causing internal damage and affecting the performance of the inverted battery cell. When w / W is greater than 93, the gap between the electrode assembly body 30 and the third wall 13 is too small, leaving too little room for expansion. When the inverted battery cell is charged, the electrode assembly body 30 expands in volume. The expanded electrode assembly body 30 abuts against and compresses the second wall 12, causing the second wall 12 to bulge outward under pressure, causing deformation of the inverted battery cell casing 10. Therefore, the ratio of the width of the electrode assembly body 30 to the width of the third wall 13 is limited.

[0044] In one embodiment, the length of the housing 10 is L, and the housing 10 further includes a third wall 13 having a thickness of B. The distance between the third wall 13 and the corresponding second side surface 32 of the electrode assembly body 30 is T3. The length of the electrode assembly body 30 is l, satisfying l = L-2×T3-2×B, and satisfying 0.96≤l / L≤0.99. By reasonably limiting the ratio of the thickness of the electrode assembly body 30 to the thickness of the housing 10, the gap between the electrode assembly body 30 and the third wall 13 is prevented from being too large, reducing the wiggle space of the electrode assembly body 30 and reducing the risk of shaking when the inverted battery cell is inverted. At the same time, the gap between the electrode assembly body 30 and the third wall 13 is prevented from being too small, preventing the electrode assembly body 30 from scraping against the third wall 13 when it is inserted into the housing.

[0045] It should be noted that when l / L is less than 0.96, the gap between the electrode assembly body 30 and the third wall 13 is too large, allowing the electrode assembly body 30 to move freely. When the battery cell is vibrated or shaken, the electrode assembly body 30 also shakes, causing internal damage and affecting the performance of the inverted battery cell. When l / L is greater than 0.99, the gap between the electrode assembly body 30 and the third wall 13 is too small, making it difficult to install the electrode assembly body 30 into the housing. When the electrode assembly body 30 is installed into the housing, it may scrape against the third wall 13, resulting in a reduction in the safety performance of the inverted battery cell. Therefore, the ratio of the thickness of the electrode assembly body 30 to the thickness of the third wall 13 is limited.

[0046] In one embodiment, the difference between the thickness of the third wall 13 and the thickness of the second wall 12 is X, which satisfies X=BM and 0.1 mm≤X≤0.25 mm.

[0047] Specifically, l = L-2×T3-2×X-2×M.

[0048] Specifically, in this embodiment, the thickness of the third wall 13 is greater than the thickness of the second wall 12 .

[0049] It should be noted that the third wall 13 is closer to the electrode group body 30 than the second wall 12. By thickening the third wall 13, heat can be conducted to the outside of the shell 10 more quickly, thereby improving the heat dissipation capacity of the flip-chip battery.

[0050] It should be noted that, compared to thickening the third wall 13, thickening the second wall 12 to improve the heat dissipation capability of the flip-chip cell significantly increases the weight of the housing 10 and occupies excessive packaging space. Therefore, in this embodiment, the thickness of the third wall 13 is greater than that of the second wall 12.

[0051] Next, vibration tests were performed on different inverted cells. The specific test results are shown in Tables 1 and 2 below.

[0052] Table 1 Vibration test results

[0053]

[0054] Table 2 Vibration test results 2

[0055]

[0056] From the test data of Examples 1 to 9 in Table 1, it can be seen that when 0.83≤h / H≤0.96, 0.86≤w / W≤0.93 and 0.96≤l / L≤0.99, the spacing between the electrode group body 30 and the shell 10 is reasonable, no abnormality occurs, and the inverted battery cell meets the requirements.

[0057] It can be seen from the test data of Comparative Examples 2 and 6 in Table 2 that when h / H is less than 0.83, the space reserved between the electrode group body 30 and the first wall 11 is too large, the risk of battery cell shaking increases, and after the X / Y / Z vibration test, the tabs are torn and the connecting pieces are broken; when h / H is greater than 0.96, the space reserved between the electrode group body 30 and the first wall 11 is too small, and damage and lithium deposition occur at the contact position between the battery cell electrode group and the first wall 11.

[0058] From the test data of Comparative Examples 1 and 3 in Table 2, it can be seen that when w / W is less than 0.86, the space reserved between the electrode group body 30 and the second wall 12 is too large, the risk of battery cell shaking increases, and after the X / Y / Z vibration test, the battery cell was disassembled and the electrode group tab was found to be torn due to stress; when w / W is greater than 93, the space reserved between the electrode group body 30 and the second wall 12 is too small, the battery cell has insufficient space for expansion, and the large surface of the battery cell is seriously bulging outward.

[0059] The test data of Comparative Examples 4 and 5 in Table 2 show that when l / L is less than 0.96, the space reserved between the electrode group body 30 and the third wall 13 is too large, increasing the risk of cell shaking. After the X / Y / Z vibration test, the battery cells were disassembled and the electrode group tabs were found to be torn due to stress. When l / L is greater than 0.99, the space reserved between the electrode group body 30 and the third wall 13 is too small, and the electrode group is easily scratched and damaged when inserted into the shell.

[0060] In summary, for the inverted cell, when the gap between the electrode group body 30 and the shell 10 is controlled within 0.83≤h / H≤0.96, 0.86≤w / W≤0.93 and 0.96≤l / L≤0.99, the spacing between the electrode group body 30 and the shell 10 is reasonable and the inverted cell meets the requirements.

[0061] According to an embodiment of the present invention, on the other hand, a battery pack is provided, comprising the above-mentioned inverted battery cell.

[0062] 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. Such modifications and variations are all within the scope defined by the accompanying invention.

Claims

1. An inverted battery cell, characterized in that: include: A housing having an opening, the housing comprising a first wall, the first wall being disposed opposite to the opening; A cell cover plate is connected to the housing and blocks the opening to enclose and form a packaging space; An electrode group body is disposed in the packaging space, and the electrode group body abuts against the battery cell cover; The height of the inverted battery cell is H0, the height of the shell is H, the height of the electrode group body is h, the thickness of the first wall is S, the distance from the top of the electrode group body to the first wall is T1, and the thickness of the battery cell cover is A, satisfying h=H0-T1-AS, 0.83≤h / H≤0.

96.

2. The inverted battery cell according to claim 1, characterized in that: The battery cell cover includes an insulating member, a cover body and a pole. The insulating member is arranged on the inner surface of the cover body, and the pole passes through the cover body and protrudes from the outer surface of the cover body. The height of the insulating member is Z, the thickness of the cover body is Y, and the height of the pole protruding from the outer surface of the cover body is C, satisfying A=Z+Y+C.

3. The inverted battery cell according to claim 2, characterized in that: The bottom surface of the cover plate body is flush with the plane where the opening is located, and the height of the pole group body is h=H-T1-ZYS.

4. The inverted battery cell according to claim 2, characterized in that: The height of the insulating member is Z, which satisfies 2.5 mm ≤ Z ≤ 8 mm.

5. The inverted battery cell according to claim 2, characterized in that: The thickness of the cover plate body is Y, which satisfies 1.5 mm ≤ Y ≤ 4 mm.

6. The inverted battery cell according to any one of claims 1 to 5, characterized in that: The thickness of the first wall is S, which satisfies 1 mm ≤ S ≤ 2 mm.

7. The inverted battery cell according to any one of claims 1 to 5, characterized in that: The width of the shell is W, and the shell also includes a second wall, the thickness of the second wall is M, the distance between the second wall and the corresponding first side surface of the pole group body is T2, and the width of the pole group body is w, satisfying w=W-2×T2-2×M, and satisfying 0.86≤w / W≤0.

93.

8. The inverted battery cell according to claim 7, characterized in that: The length of the shell is L, and the shell also includes a third wall, the thickness of the third wall is B, the distance between the third wall and the corresponding second side of the pole group body is T3, the length of the pole group body is l, satisfying l=L-2×T3-2×B, and satisfying 0.96≤l / L≤0.

99.

9. The inverted battery cell according to claim 8, characterized in that: The difference between the thickness of the third wall and the thickness of the second wall is X, which satisfies X=BM and 0.1 mm≤X≤0.25 mm.

10. A battery pack, characterized in that: The inverted battery cell comprises the inverted battery cell according to any one of claims 1 to 9.

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