Battery cell and battery module
By creating a notched corner structure on the protruding part of the insulation component, the problem of the corners of the electrode assembly being damaged by pressure is solved, thereby improving the process yield and safety performance of the battery cell.
Patent Information
- Application Number
- CN202510957013.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-11
- Publication Date
- 2025-10-17
AI Technical Summary
In the prior art, the electrode group corners of blade cells are easily crushed under the pressure of insulating components, which affects the process yield and safety performance of the cell.
A notched structure is created on the protruding part of the insulating component to avoid the corners of the pole group. By limiting the value, the effectiveness and fixation of the insulating component are ensured, and the corners of the pole group are prevented from being damaged by pressure.
This improves the manufacturing yield and safety performance of the battery cells, avoids pressure damage at the corners of the electrode assembly, and ensures effective fixation of the insulation components to the electrode assembly.
Smart Images
Figure CN120810108A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of energy storage devices, in particular to a battery cell and a battery module. BACKGROUND
[0002] In the prior art, the end of the blade cell along the length direction of the blade cell has a cover plate structure, and the cover plate structure is provided with an insulating piece to prevent the top cover of the metal material of the cover plate structure from being in conduction with the pole. The insulating piece of the cover plate structure is attached to the inner side of the top cover, and the side of the insulating piece away from the top cover is pressed against the end face of the pole group. Especially in the process of the pole group entering the shell, and when the finished battery cell is in the environment of vibration, impact, etc., the pole group moves inside the shell, the acting force between the insulating piece and the pole group will increase, and the corner part of the pole group will often be pressed by the insulating piece, thereby affecting the process yield and safety performance of the battery cell. SUMMARY
[0003] An object of the present application is to provide a battery cell which can prevent the corner part of the pole group from being pressed by the insulating piece, and improve the process yield and safety performance of the battery cell.
[0004] To achieve this object, the present application adopts the following technical solutions:
[0005] Provided is a battery cell, comprising:
[0006] a pole group;
[0007] a cover plate structure, the cover plate structure comprising an insulating piece, the insulating piece having a protruding part, a first end face of the protruding part pressing against a second end face of the pole group, so that the compression amount of the pole group at the second end face along the length direction of the pole group is H0, a corner part of the first end face being provided with a corner-removed structure, the corner-removed structure being provided corresponding to a corner part of the second end face, the corner-removed structure along the cross section of the first end face being a first cross section, the size of the first cross section along the length direction of the insulating piece being L1, the size of the first cross section along the width direction of the insulating piece being W1, the size of the corner-removed structure along the length direction of the pole group being H1, the length of the insulating piece being L2, the width of the insulating piece being W2, the size of the second end face along the length direction of the insulating piece being L3, the size of the second end face along the width direction of the insulating piece being W3, satisfying: the length direction of the pole group, the length direction of the insulating piece, and the width direction of the insulating piece being perpendicular to each other in pairs.
[0008] Optionally, the size L1 of the first cross section along the length direction of the insulating piece and the length L2 of the insulating piece satisfy: 0.035≤L1 / L2≤0.055.
[0009] And / or, the size W1 of the first cross section along the width direction of the insulation piece and the size W2 of the insulation piece satisfy: 0.05≤W1 / W2≤0.09.
[0010] Optionally, the size L1 of the first cross section along the length direction of the insulation piece and the size L3 of the second end surface along the length direction of the insulation piece satisfy: 0.03≤L1 / L3≤0.05.
[0011] And / or, the size W1 of the first cross section along the width direction of the insulation piece and the size W3 of the second end surface along the width direction of the insulation piece satisfy: 0.05≤W1 / W3≤0.09.
[0012] Optionally, the compression amount H0 of the pole group at the second end surface along the length direction of the pole group and the size H1 of the corner-omitted structure along the length direction of the pole group satisfy: 0.35≤H0 / H1≤0.8.
[0013] Optionally, the size L1 of the first cross section along the length direction of the insulation piece satisfies: 3mm≤L1≤7mm.
[0014] And / or, the size W1 of the first cross section along the width direction of the insulation piece satisfies: 3mm≤W1≤7mm.
[0015] Optionally, the size H1 of the corner-omitted structure along the length direction of the pole group and the size H2 of the insulation piece along the length direction of the pole group satisfy: 35%≤H1 / H2≤70%.
[0016] Optionally, the insulation piece is provided with one of the protrusions at each end along the length direction of the insulation piece, and each of the two protrusions is provided with the corner-omitted structure, and the four corner-omitted structures of the two protrusions correspond to the four corner portions of the second end surface respectively.
[0017] Optionally, the protrusion is provided with the first wall surface and the second wall surface after the corner-omitted structure is formed, the first wall surface is parallel to the length direction of the pole group, and the second wall surface is perpendicular to the length direction of the pole group.
[0018] Optionally, the first transition curved surface is formed at the junction of the first wall surface and the side wall of the protrusion.
[0019] And / or, the second transition curved surface is formed at the junction of the second wall surface and the side wall of the protrusion.
[0020] Another object of the present application is to provide a battery module, the corner portion of the pole group of the battery cell is not easily damaged by the insulation piece, and the battery cell has higher process yield and safety performance.
[0021] To achieve the above object, the present application adopts the following technical solutions:
[0022] The present application provides a battery module, which comprises a module shell and at least one battery cell as described above, and the at least one battery cell is arranged in the module shell.
[0023] The present application has the following beneficial effects:
[0024] The present application provides a battery cell, which comprises a pole group and a cover plate structure. The cover plate structure comprises an insulating piece, the insulating piece has a protruding part, a first end surface of the protruding part abuts against a second end surface of the pole group, so that a compression amount of the pole group at the second end surface along a length direction of the pole group is H0, an angle part of the first end surface is provided with a notched structure, the notched structure is provided corresponding to an angle part of the second end surface, a first cross section of the notched structure along the first end surface is L1, a second cross section of the notched structure along a width direction of the insulating piece is W1, a length of the notched structure along the length direction of the pole group is H1, a length of the insulating piece is L2, a width of the insulating piece is W2, a length of the second end surface along the length direction of the insulating piece is L3, and a width of the second end surface along the width direction of the insulating piece is W3, and the following conditions are met: The length direction of the pole group, the length direction of the insulating piece and the width direction of the insulating piece are perpendicular to each other. By providing the notched structure corresponding to the angle part of the pole group on the protruding part of the insulating piece, the insulating piece can avoid the angle part of the pole group, and the angle part of the pole group is prevented from being damaged by the insulating piece. By limiting the values of L1, W1 and H1, the effectiveness of the notched structure can be improved, and the fixing effect of the insulating piece on the pole group is ensured, and the process yield and safety performance of the battery cell are further improved.
[0025] The present application also provides a battery module, which comprises a module shell and at least one battery cell as described above, and the at least one battery cell is arranged in the module shell. The angle part of the pole group of the battery cell of the battery module is not easily damaged by the insulating piece, and the battery cell has higher process yield and safety performance. BRIEF DESCRIPTION OF DRAWINGS
[0026] Figure 1 is a partial structure schematic view of the battery cell provided by the embodiment of the present application;
[0027] Figure 2 is a structure schematic view of the cover plate structure from a first perspective according to the embodiment of the present application;
[0028] Figure 3 is a structure schematic view of the cover plate structure from a second perspective according to the embodiment of the present application; Figure 2 is an enlarged view of A;
[0029] Figure 4 is a structure schematic view of the cover plate structure from a second perspective according to the embodiment of the present application;
[0030] Figure 5 Fig. 3 is a structural schematic view of a third perspective of the cover structure provided by an embodiment of the present application.
[0031] In the drawings:
[0032] 1, pole group; 11, pole lug; 12, second end face;
[0033] 2, insulating piece; 21, protruding part; 211, first end face; 212, notched structure; 213, first wall face; 214, second wall face; 215, first transition curved surface; 216, chamfered structure; 217, second transition curved surface; 218, third transition curved surface;
[0034] 3, first top cover; 4, second top cover; 5, end plate. DETAILED DESCRIPTION
[0035] The technical solutions of the present application will be further described below in conjunction with the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present application, but not to limit the present application. In addition, it should be noted that, for the convenience of description, only the parts related to the present application are shown in the drawings, but not all.
[0036] In the description of the present application, it should be noted that, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting" should be understood in a broad sense, for example, it can be fixed connection, or detachable connection; it can be mechanical connection, or electrical connection; it can be direct connection, or indirect connection through intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.
[0037] In the present application, unless otherwise explicitly specified and limited, the "upper" or "lower" of the first feature to the second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the "over", "above" and "on" of the first feature to the second feature includes that the first feature is directly above and obliquely above the second feature, or only means that the horizontal height of the first feature is higher than that of the second feature. The "under", "below" and "under" of the first feature to the second feature includes that the first feature is directly below and obliquely below the second feature, or only means that the horizontal height of the first feature is less than that of the second feature.
[0038] In the prior art, the end of the blade cell along the length direction of the blade cell has a cover plate structure, and the cover plate structure is provided with an insulating piece to prevent the top cover of the cover plate structure from being in conduction with the pole. The insulating piece of the cover plate structure is attached to the inner side of the top cover, and the side of the insulating piece away from the top cover is pressed against the end face of the pole group. Especially during the process of the pole group entering the shell, and when the finished cell is in the environment of vibration, impact, etc., the pole group moves inside the shell, the acting force between the insulating piece and the pole group will increase, and the corner of the pole group is often pressed by the insulating piece, which affects the process yield and safety performance of the cell.
[0039] Therefore, the present embodiment provides a cell to solve the above problems, which can prevent the corner of the pole group 1 from being pressed by the insulating piece 2, and has higher process yield and safety performance.
[0040] As shown in Figure 1-Figure 5 The cell of the present embodiment includes a pole group 1 and a cover plate structure. The cover plate structure includes an insulating piece 2, and the insulating piece 2 has a protruding portion 21, and the first end face 211 of the protruding portion 21 is pressed against the second end face 12 of the pole group 1, so that the compression amount of the pole group 1 at the second end face 12 along the length direction of the pole group 1 is H0. It should be noted that the compression amount H0 here refers to the compression amount of the pole group 1 at the second end face 12, not the overall compression amount of the pole group 1 along the length direction of the pole group 1.
[0041] The corner of the first end face 211 is provided with a corner missing structure 212, and the corner missing structure 212 is provided corresponding to the corner of the second end face 12. The first cross section of the corner missing structure 212 along the first end face 211 is a first cross section, the size of the first cross section of the corner missing structure 212 along the length direction of the insulating piece 2 is L1, the size of the first cross section of the corner missing structure 212 along the width direction of the insulating piece 2 is W1, the size of the corner missing structure 212 along the length direction of the pole group 1 is H1, the length of the insulating piece 2 is L2, the width of the insulating piece 2 is W2, the size of the second end face 12 along the length direction of the insulating piece 2 is L3, and the size of the second end face 12 along the width direction of the insulating piece 2 is W3, which satisfies:
[0042] The length direction of the pole group 1, the length direction of the insulating piece 2 and the width direction of the insulating piece 2 are perpendicular to each other. In the present embodiment, the length direction of the pole group 1 is parallel or coincides with the thickness direction of the insulating piece 2, the length direction of the insulating piece 2 is parallel or coincides with the width direction of the pole group 1, and the width direction of the insulating piece 2 is parallel or coincides with the thickness direction of the pole group 1. Figure 1 In the ab direction of the pole group 1, the cd direction is the width direction of the pole group 1, and the ef direction is the thickness direction of the pole group 1.
[0043] By opening the notch structure 212 on the protruding part 21 of the insulating piece 2 corresponding to the corner of the pole group 1, the insulating piece 2 can avoid the corner of the pole group 1, preventing the corner of the pole group 1 from being damaged by the insulating piece 2. By limiting the value of , the effectiveness of the notch structure 212 can be improved, while ensuring the fixing effect of the insulating piece 2 on the pole group 1, further improving the process yield and safety performance of the battery cell.
[0044] By limiting the value of , the ratio of the area of the first cross section of the notch structure 212 to the maximum cross section of the insulating piece 2 along the direction perpendicular to the thickness of the insulating piece 2, the ratio of the area of the first cross section of the notch structure 212 to the area of the second end surface 12, and the ratio of the compression amount H0 of the second end surface 12 along the length direction of the pole group 1 to the size H1 of the notch structure 212 along the length direction of the pole group 1 can be limited to a certain extent.
[0045] It can be known that when the value of is greater than 0.65 as a whole, the first two of the above three ratios may be too large and the last one may be too small. The first ratio is too large, that is, the first cross section of the notch structure 212 occupies too large a proportion of the cross section of the insulating piece 2, which will cause the first end surface 211 to occupy too small a proportion or the cross section of the protruding part 21 as a whole to be too large. The former will cause the contact area between the insulating piece 2 and the pole group 1 to be too small, resulting in poor fixing effect of the insulating piece 2 on the pole group 1, or local excessive pressure, which is easy to cause damage to the second end surface 12 of the pole group 1. The latter will cause the space reserved for the tab 11 by the insulating piece 2 to be too small, which is easy to interfere with the tab 11, causing the tab 11 to be broken under stress, etc. The second ratio is too large, that is, the first cross section of the notch structure 212 occupies too large a proportion of the second end surface 12 of the pole group 1, which can achieve the avoidance effect of the notch structure 212, that is, to ensure that the corner of the pole group 1 is not damaged. However, if the proportion of the notch structure 212 is too large, the size of the space reserved for the tab 11 by the insulating piece 2 or the contact area between the protruding part 21 and the pole group 1 will be reduced, which will cause the insulating piece 2 to interfere with the tab 11, causing the tab 11 to be damaged, or the fixing effect of the insulating piece 2 on the pole group 1 to be poor. The third ratio is too small, that is, the ratio of the compression amount H0 of the second end surface 12 along the length direction of the pole group 1 to the size H1 of the notch structure 212 along the length direction of the pole group 1 is too small. If the compression amount H0 is too small, the fixing effect of the insulating piece 2 on the pole group 1 will also be poor.
[0046] When the value of When the value of the first ratio is less than 0.25, it means that the first two ratios are too small and the last one is too large. When the first ratio is too small, i.e. the ratio of the first cross section of the corner-removing structure 212 to the cross section of the insulation piece 2 is too small, or the second ratio is too small, i.e. the ratio of the first cross section of the corner-removing structure 212 to the second end surface 12 of the pole group 1 is too small, or the third ratio is too large, i.e. the compression amount H0 is too small or the size H1 of the corner-removing structure 212 along the length direction of the pole group 1 is too large, the corner-removing structure 212 will fail, i.e. the corner portion of the pole group 1 will still be crushed or the corner-removing structure 212 will still shallowly crush the corner portion of the pole group 1.
[0047] Optionally, the size L1 of the first cross section of the corner-removing structure 212 along the length direction of the insulation piece 2 and the length L2 of the insulation piece 2 satisfy: 0.035≤L1 / L2≤0.055. If the ratio of the size L1 of the first cross section of the corner-removing structure 212 along the length direction of the insulation piece 2 to the length L2 of the insulation piece 2 is less than 0.035, the size of the corner-removing structure 212 along the length direction of the insulation piece 2 will be too small to crush the position near the corner portion of the pole group 1 when the length of the insulation piece 2 is constant. If the ratio of the size L1 of the first cross section of the corner-removing structure 212 along the length direction of the insulation piece 2 to the length L2 of the insulation piece 2 is greater than 0.055, the size of the corner-removing structure 212 along the length direction of the insulation piece 2 will be too large to guarantee the effectiveness of the corner-removing structure 212, but will affect the contact area of the first end surface 211 with the pole group 1 or affect the reserved space of the insulation piece 2 for the pole lug 11. The former will cause the insulation piece 2 to excessively concentrate on the pole group 1, and the pole group 1 will be subjected to excessive local pressure, which may also cause the pole group 1 to be insufficiently fixed by the insulation piece 2. The latter will cause the pole lug 11 to be interfered, resulting in quality problems.
[0048] Optionally, the size L1 of the first cross section of the corner- missing structure 212 along the length direction of the insulation piece 2 and the size L3 of the second end surface 12 along the length direction of the insulation piece 2 satisfy: 0.03≤L1 / L3≤0.05. If the ratio of the size L1 of the first cross section of the corner- missing structure 212 along the length direction of the insulation piece 2 and the size L3 of the second end surface 12 along the length direction of the insulation piece 2 is less than 0.03, then in the case that the length of the second end surface 12 of the pole group 1 is constant, the size of the corner- missing structure 212 along the length direction of the insulation piece 2 is too small, so that the position near the corner of the pole group 1 is still pressed. If the ratio of the size L1 of the first cross section of the corner- missing structure 212 along the length direction of the insulation piece 2 and the size L3 of the second end surface 12 along the length direction of the insulation piece 2 is greater than 0.05, then in the case that the length of the second end surface 12 of the pole group 1 is constant, the size of the corner- missing structure 212 along the length direction of the insulation piece 2 is too large, which can ensure the effectiveness of the corner- missing structure 212, the corner of the pole group 1 will not be pressed, but will affect the contact area of the first end surface 211 with the pole group 1 or the accommodation space of the tab 11 on the insulation piece 2, the former will cause the insulation piece 2 to act too concentratedly on the pole group 1, the local pressure of the pole group 1 is too large, and the latter will cause the tab 11 to be interfered, resulting in quality problems.
[0049] Optionally, the size L1 of the first cross section of the corner- missing structure 212 along the length direction of the insulation piece 2 satisfies: 3mm≤L1≤7mm. If the size L1 of the first cross section of the corner- missing structure 212 along the length direction of the insulation piece 2 is less than 3mm, then due to factors such as machining error, assembly error, etc., the corner of the pole group 1 will still be pressed by the insulation piece 2. If the size L1 of the first cross section of the corner- missing structure 212 along the length direction of the insulation piece 2 is greater than 7mm, then the corner- missing structure 212 occupies too much space of the protruding part 21, which will cause the contact area of the first end surface 211 of the protruding part 21 with the pole group 1 to be insufficient, resulting in that the pole group 1 is not fixed firmly by the insulation piece 2, or the pole group 1 is pressed too concentratedly, causing the problem of local pressing of the pole group 1. Therefore, the size L1 of the first cross section of the corner- missing structure 212 along the length direction of the insulation piece 2 is taken in the range of 3mm-7mm, which can ensure the effectiveness of the protruding part 21 avoiding the corner of the pole group 1, without affecting the fixation of the pole group 1 by the insulation clamp, without causing the problem of pressing of the pole group 1, so as to improve the process yield of the battery cell.
[0050] Optionally, the dimension W1 of the first cross section of the notch structure 212 along the width direction of the insulation piece 2 and the width W2 of the insulation piece 2 satisfy: 0.05≤W1 / W2≤0.09. If the ratio of the dimension W1 of the first cross section of the notch structure 212 along the width direction of the insulation piece 2 and the width W2 of the insulation piece 2 is less than 0.05, then the dimension of the notch structure 212 along the width direction of the insulation piece 2 will be too small under the condition that the width of the insulation piece 2 is constant, so that the position near the corner of the pole group 1 will still be crushed. If the ratio of the dimension W1 of the first cross section of the notch structure 212 along the width direction of the insulation piece 2 and the width W2 of the insulation piece 2 is greater than 0.09, then the dimension of the notch structure 212 along the width direction of the insulation piece 2 will be too large under the condition that the width of the insulation piece 2 is constant, which can ensure the effectiveness of the notch structure 212, but will affect the contact area of the first end surface 211 with the pole group 1 or the reserved space of the insulation piece 2 for the tab 11, the former will cause the insulation piece 2 to act on the pole group 1 too much, the local pressure of the pole group 1 will be too large, and the latter will cause the tab 11 to be interfered, resulting in quality problems.
[0051] Optionally, the dimension W1 of the first cross section of the notch structure 212 along the width direction of the insulation piece 2 and the dimension W3 of the second end surface 12 along the width direction of the insulation piece 2 satisfy: 0.05≤W1 / W3≤0.09. If the ratio of the dimension W1 of the first cross section of the notch structure 212 along the width direction of the insulation piece 2 and the dimension W3 of the second end surface 12 along the width direction of the insulation piece 2 is less than 0.05, then the dimension of the notch structure 212 along the width direction of the insulation piece 2 will be too small under the condition that the width of the second end surface 12 of the pole group 1 is constant, so that the position near the corner of the pole group 1 will still be crushed. If the ratio of the dimension W1 of the first cross section of the notch structure 212 along the width direction of the insulation piece 2 and the dimension W3 of the second end surface 12 along the width direction of the insulation piece 2 is greater than 0.09, then the dimension of the notch structure 212 along the width direction of the insulation piece 2 will be too large under the condition that the width of the second end surface 12 of the pole group 1 is constant, which can ensure the effectiveness of the notch structure 212, but will affect the contact area of the first end surface 211 with the pole group 1 or the reserved space of the insulation piece 2 for the tab 11, the former will cause the insulation piece 2 to act on the pole group 1 too much, the local pressure of the pole group 1 will be too large, and the latter will cause the tab 11 to be interfered, resulting in quality problems.
[0052] Optionally, the dimension W1 of the first cross section of the corner-omitted structure 212 along the width direction of the insulation piece 2 satisfies: 3mm≤W1≤7mm. If the dimension W1 of the first cross section of the corner-omitted structure 212 along the width direction of the insulation piece 2 is less than 3mm, the corner of the pole group 1 can still be pressed by the insulation piece 2 due to processing errors, assembly errors, and other factors. If the dimension W1 of the first cross section of the corner-omitted structure 212 along the width direction of the insulation piece 2 is greater than 7mm, the corner-omitted structure 212 occupies too much space in the width direction of the protruding part 21, which can cause the contact area between the first end surface 211 of the protruding part 21 and the pole group 1 to be insufficient, resulting in that the pole group 1 is not firmly fixed by the insulation piece 2, or the pole group 1 is pressed too concentratedly, causing the pole group 1 to be locally pressed. Therefore, the dimension W1 of the first cross section of the corner-omitted structure 212 along the width direction of the insulation piece 2 is in the range of 3mm-7mm, which can ensure that the protruding part 21 effectively avoids the corner of the pole group 1, and at the same time, does not affect the fixation of the pole group 1 by the insulation clamp, and does not cause the pole group 1 to be pressed. Therefore, the process yield of the battery cell can be improved.
[0053] Optionally, the compression amount H0 of the pole group 1 along the length direction of the pole group 1 at the second end surface 12 and the dimension H1 of the corner-omitted structure 212 along the length direction of the pole group 1 satisfy: 0.35≤H0 / H1≤0.8. If the ratio of the compression amount H0 of the pole group 1 along the length direction of the pole group 1 at the second end surface 12 and the dimension H1 of the corner-omitted structure 212 along the length direction of the pole group 1 is less than 0.35, there can be a problem that the compression amount H0 of the pole group 1 along the length direction of the pole group 1 at the second end surface 12 is too small, or the dimension H1 of the corner-omitted structure 212 along the length direction of the pole group 1 is too large. If the compression amount H0 of the pole group 1 along the length direction of the pole group 1 at the second end surface 12 is too small, the pole group 1 can not be pressed enough, and the pole group 1 can shift during subsequent use, which is not conducive to ensuring the safety of the pole group 1 in use. If the dimension H1 of the corner-omitted structure 212 along the length direction of the pole group 1 is too large, the remaining thickness at the corner-omitted structure 212 will be too small under the condition that the thickness of the insulation piece 2 is constant, and the structural strength of the insulation piece 2 at this position will be too small, which is prone to deformation under stress, and is not conducive to ensuring the insulation effectiveness of the insulation piece 2 at this position. If the ratio of the compression amount H0 of the pole group 1 along the length direction of the pole group 1 at the second end surface 12 and the dimension H1 of the corner-omitted structure 212 along the length direction of the pole group 1 is greater than 0.8, the compression amount H0 of the pole group 1 along the length direction of the pole group 1 at the second end surface 12 and the dimension H1 of the corner-omitted structure 212 along the length direction of the pole group 1 are too close, and when there are processing errors and assembly errors, the corner of the pole group 1 can still contact the first wall surface 213 of the corner-omitted structure 212, causing the corner of the pole group 1 to be pressed.
[0054] Optionally, the compression amount H0 at the second end surface 12 along the length direction of the electrode group 1 is in the range of 1.5 mm to 2.5 mm, so as to ensure the effectiveness of the corner-cut structure 212 while preventing the electrode group 1 from moving.
[0055] Optionally, the dimension H1 of the notched structure 212 along the length of the pole group 1 and the dimension H2 of the insulating member 2 along the length of the pole group 1 satisfy the following: 35% ≤ H1 / H2 ≤ 70%. If the ratio of the dimension H1 of the notched structure 212 along the length of the pole group 1 to the dimension H2 of the insulating member 2 along the length of the pole group 1 is less than 35%, the notched structure 212 is too shallow. When there are machining errors and assembly errors, the corner of the pole group 1 may still contact the first wall 213 of the notched structure 212, causing the corner of the pole group 1 to still be compressed. If the ratio of the dimension H1 of the notched structure 212 along the length of the pole group 1 to the dimension H2 of the insulating member 2 along the length of the pole group 1 is greater than 70%, the notched structure 212 is too deep, the remaining thickness of the insulating member 2 at the notched structure 212 will be too small, the structural strength of the insulating member 2 at this location will be too weak, and it will be easily deformed by force, which is not conducive to ensuring the insulation effectiveness of the insulating member 2 at this location.
[0056] Optionally, the insulating member 2 is provided with a protrusion 21 at each end along its length, and both protrusions 21 are provided with a notched structure 212. The four notched structures 212 of the two protrusions 21 correspond to the four corners of the second end surface 12. The space between the two protrusions 21 of the insulating member 2 can accommodate the tab 11 of the pole group 1 or the electrical connector between the tab 11 and the pole column.
[0057] Optionally, the protrusion 21 is provided with a notched structure 212 to form a first wall 213 and a second wall 214 that are perpendicular to each other. The first wall 213 is parallel to the length of the electrode assembly 1. The first wall 213 faces the side of the battery cell shell, and the second wall 214 faces the second end face 12 of the electrode assembly 1. In other words, the notched structure 212 is provided along the length of the electrode assembly 1, or in other words, along the thickness of the insulating member 2. In this embodiment, the notched structure 212 is a virtual body similar to a triangular prism.
[0058] like Figure 2 and Figure 3 As shown, to prevent sharp edges at the notched structure 212, optionally, the intersection of the first wall surface 213 and the side wall of the protrusion 21 is a first transition curved surface 215. Further optionally, the intersection of the first wall surface 213 and both side walls of the protrusion 21 is a first transition curved surface 215. Optionally, the intersection of the second wall surface 214 and the side wall of the protrusion 21 is a second transition curved surface 217. Further optionally, the intersection of the second wall surface 214 and both side walls of the protrusion 21 is a second transition curved surface 217.
[0059] Optionally, the side edges of the two protrusions 21 corresponding to the corners of the second end face 12 of the pole group 1 are also provided with third transition curved surfaces 218, that is, the four side edges of the two protrusions 21 are all provided with third transition curved surfaces 218.
[0060] Optionally, in the present embodiment, the junction side edges of the first wall surface 213 and the first end face 211 are also provided with chamfer structures 216, which not only can expand the avoiding range of the protrusions 21 to the pole group 1 on the basis of the first section, but also can blunt the edges of the first end face 211, so as to further increase the avoiding effect. It should be noted that the size of the above-mentioned first section is the size before the chamfer structure 216 is opened.
[0061] Optionally, in the present embodiment, the side edges of the first end face 211 of the protrusions 21 are also provided with chamfer structures 216, and the opening of these chamfer structures 216 can ensure that the protrusions 21 avoid the edges of the second end face 12 of the pole group 1. Optionally, the chamfer structures 216 are all 45° chamfers, and the size of the right-angle edge is in the range of 0.5mm-1.5mm.
[0062] In order to verify that the above-mentioned battery cell can avoid the corners of the pole group 1 being pressed and damaged, and also prevent the pole group 1 from moving and shifting due to insufficient fixation, and has a higher process yield, the present embodiment detects battery cells of different size specifications. The specific detection contents include whether the second end face 12 of the pole group 1 and the tab 11 of the battery cell exist abnormities after the pole group 1 is assembled into the shell, whether the pole group 1 will move and shift, whether the tab 11 will be torn, and whether the corners of the pole group 1 will be pressed and damaged during the vibration test of the assembled battery cell.
[0063] As shown in the following Table 1 and Table 2, the present embodiment provides twelve groups of examples and four groups of comparative examples of battery cells. The same points of the twelve groups of examples and the four groups of comparative examples of battery cells are that they satisfy the following conditions: 0.03≤L1 / L3≤0.05, 3mm≤L1≤7mm, 0.05≤W1 / W2≤0.09, 0.05≤W1 / W3≤0.09, 3mm≤W1≤7mm, 1.5mm≤H0≤2.5mm, 35%≤H1 / H2≤70%.
[0064] As shown in the following Table 1, the battery cells of the twelve groups of examples all satisfy the following conditions: 0.035≤L1 / L2≤0.055, 0.35≤H0 / H1≤0.8. After testing, the second end face 12 of the electrode group 1 and the tab 11 of the twelve battery cells were found to be normal after the electrode group 1 was assembled into the shell. During the vibration test of the assembled battery cells, the electrode group 1 did not move, the tab 11 did not tear, and the corners of the electrode group 1 did not suffer any damage. It can be seen that when the battery cells meet the above-mentioned more optimal value range, not only are the corners of the electrode group 1 not damaged, but the insulating member 2 can also fix the electrode group 1, the electrode group 1 does not move, and the insulating member 2 does not damage the second end face 12 of the electrode group 1, and the tab 11 does not tear, and the battery cells have a higher process yield.
[0065] Table 1
[0066]
[0067] As shown in Table 2 below, the battery cells of Comparative Example 1 The value is 0.69, which is greater than the maximum value of the optimal range of 0.65. Testing showed no crush damage at the corners of the electrode group 1 in this group of cells, indicating that the corner-cut structure 212 has a protective effect. However, the insulating member 2 of this group of cells does not properly secure the electrode group 1. Five cells were sampled for vibration testing and CT scanning. Two of them showed significant movement of the electrode group 1 and tearing of the tab 11.
[0068] As shown in Table 2 below, the ratio of L1 to L2 for the battery cells in Comparative Example 2 was 0.062, exceeding the optimal maximum value of 0.055. Testing showed no crush damage at the corners of the electrode group 1 in this group of cells, indicating that the corner-cut structure 212 provided a relief effect. However, the insulating member 2 in this group of cells did not properly secure the electrode group 1. Five cells were sampled for vibration testing and CT scanning. Two of them showed significant movement of the electrode group 1 and tearing of the tab 11.
[0069] As shown in Table 2 below, the ratio of H0 to H1 of the battery cell of Comparative Example 3 is 0.833, which is greater than the maximum value of 0.8 in the optimal value range. That is, the depth of the notched structure 212 of this battery cell is too close to the single-sided compression depth of the electrode group 1. The value of 0.24 is less than the minimum value of the optimal range of 0.25, indicating that the corner-cut structure 212 is insufficiently provided. After electrode assembly 1 was inserted into the battery cell, X-ray examination revealed slight crush damage on the second end surface 12 of electrode assembly 1. This indicates that the provision of the corner-cut structure 212 can alleviate the crush damage issue to a certain extent, and meeting the aforementioned optimal range of values can completely resolve the crush damage issue at the corners of electrode assembly 1.
[0070] As shown in Table 2 below, the ratio of H0 to H1 of the battery cell of Comparative Example 4 is 0.880, which is greater than the maximum value 0.8 of the more optimal value range, i.e. the depth of the corner-omitted structure 212 of the battery cell is too close to the single-sided compression depth of the pole group 1. It is detected that after the pole group 1 enters the shell, the battery cell is detected by X-Ray to have a slight crushing problem at the second end surface 12 of the pole group 1. It can be seen that the corner-omitted structure 212 can solve the crushing problem to a certain extent, and the crushing problem of the corner of the pole group 1 can be completely solved by meeting the more optimal value range.
[0071] Table 2
[0072]
[0073] Optionally, in the embodiment, one end of the battery cell has a cover plate structure, which includes the insulating piece 2 and the first top cover 3. Optionally, the insulating piece 2 is a lower plastic. Optionally, the other end of the battery cell has the second top cover 4 and the end plate 5. Of course, in other embodiments, the other end of the battery cell can also not be provided with the end plate 5, and still be provided with the insulating piece 2 having the protruding part 21.
[0074] The embodiment also provides a battery module, which includes a module shell and at least one battery cell as described above, and the at least one battery cell is arranged in the module shell. Optionally, in the embodiment, a plurality of battery cells are arranged, and the plurality of battery cells are arranged in sequence along the thickness direction of the battery cells.
[0075] The battery cell of the battery module can avoid the corner of the pole group 1 by opening the corner-omitted structure 212 on the protruding part 21 of the insulating piece 2 corresponding to the corner of the pole group 1, so as to prevent the corner of the pole group 1 from being crushed by the insulating piece 2. And by limiting the value of H1 / H0, the effectiveness of the corner-omitted structure 212 can be improved, while the fixing effect of the insulating piece 2 on the pole group 1 is ensured, and the process yield and safety performance of the battery cell are further improved.
[0076] Obviously, the above embodiments of the application are merely exemplary and are not intended to limit the implementation modes of the application. Based on the above description, those skilled in the art can make other different forms of changes or modifications. Here, all the implementation modes are not required or possible to be exhausted. Any modification, equivalent replacement and improvement made within the spirit and principle of the application shall be included in the protection scope of the claims of the application.
Claims
1. A battery cell, characterized in that: include: Pole group (1); A cover plate structure, the cover plate structure comprising an insulating member (2), the insulating member (2) having a protruding portion (21), the first end face (211) of the protruding portion (21) pressing against the second end face (12) of the pole group (1), so that the compression amount of the pole group (1) at the second end face (12) along the length direction of the pole group (1) is H0, the corner of the first end face (211) is provided with a notch structure (212), the notch structure (212) is provided corresponding to the corner of the second end face (12), and the notch structure (212) is provided along the first end face The cross section of (211) is a first cross section, the dimension of the first cross section along the length direction of the insulating member (2) is L1, the dimension of the first cross section along the width direction of the insulating member (2) is W1, the dimension of the missing corner structure (212) along the length direction of the pole group (1) is H1, the length of the insulating member (2) is L2, the width of the insulating member (2) is W2, the dimension of the second end face (12) along the length direction of the insulating member (2) is L3, and the dimension of the second end face (12) along the width direction of the insulating member (2) is W3, satisfying: ≤0.65, the length direction of the pole group (1), the length direction of the insulating member (2), and the width direction of the insulating member (2) are perpendicular to each other.
2. The battery cell according to claim 1, characterized in that The dimension L1 of the first cross section along the length direction of the insulating member (2) and the length L2 of the insulating member (2) satisfy the following conditions: 0.035≤L1 / L2≤0.055; And / or, the dimension W1 of the first cross section along the width direction of the insulating member (2) and the width W2 of the insulating member (2) satisfy: 0.05≤W1 / W2≤0.
09.
3. The battery cell according to claim 1, characterized in that The dimension L1 of the first cross section along the length direction of the insulating member (2) and the dimension L3 of the second end surface (12) along the length direction of the insulating member (2) satisfy the following conditions: 0.03≤L1 / L3≤0.05; And / or, the dimension W1 of the first cross section along the width direction of the insulating member (2) and the dimension W3 of the second end surface (12) along the width direction of the insulating member (2) satisfy: 0.05≤W1 / W3≤0.
09.
4. The battery cell according to claim 1, characterized in that The compression amount H0 of the pole group (1) at the second end surface (12) along the length direction of the pole group (1) and the dimension H1 of the corner-cut structure (212) along the length direction of the pole group (1) satisfy: 0.35≤H0 / H1≤0.
8.
5. The battery cell according to any one of claims 1 to 4, characterized in that: The dimension L1 of the first cross section along the length direction of the insulating member (2) satisfies the following conditions: 3 mm ≤ L1 ≤ 7 mm; And / or, a dimension W1 of the first cross section along the width direction of the insulating member (2) satisfies: 3mm≤W1≤7mm.
6. The battery cell according to any one of claims 1 to 4, characterized in that: The dimension H1 of the notched structure (212) along the length direction of the pole group (1) and the dimension H2 of the insulating member (2) along the length direction of the pole group (1) satisfy the following relationship: 35%≤H1 / H2≤70%.
7. The battery cell according to any one of claims 1 to 4, characterized in that: The insulating member (2) is provided with a protruding portion (21) at each end along its length direction, and both protruding portions (21) are provided with a notched corner structure (212). The four notched corner structures (212) of the two protruding portions (21) respectively correspond to the four corners of the second end surface (12).
8. The battery cell according to any one of claims 1 to 4, characterized in that: After the protruding portion (21) is provided with the notched structure (212), a first wall surface (213) and a second wall surface (214) are formed, wherein the first wall surface (213) is parallel to the length direction of the pole group (1), and the second wall surface (214) is perpendicular to the length direction of the pole group (1).
9. The battery cell according to claim 8, characterized in that The junction between the first wall surface (213) and the side wall of the protruding portion (21) is a first transition curved surface (215); And / or, the junction between the second wall surface (214) and the side wall of the protruding portion (21) is a second transition curved surface (217).
10. A battery module, characterized in that: The invention comprises a module housing and at least one battery cell according to any one of claims 1 to 9, wherein the at least one battery cell is arranged in the module housing.