Cover plate assembly, battery cell and battery

Abstract

The utility model provides a cover plate assembly, a battery cell and a battery, and relates to the technical field of batteries. The cover plate assembly comprises a cover plate and a pole; the cover plate is provided with a mounting hole and has a width size W and a length size L; the pole comprises a main body, one end of the main body is provided with a tab connecting groove, the main body is arranged in the mounting hole in a penetrating manner, the main body has a width dimension b'in the direction of the width dimension W, and the main body has a length dimension a 'in the direction of the length dimension L; wherein b 'is larger than or equal to W-6 mm and smaller than or equal to W-8 mm, and b' / a 'is larger than or equal to 0.4 and smaller than or equal to 0.9. By limiting the width b'of the main body relative to the width W of the cover plate, the width of the main body can be large, and the strength of the cover plate in the width direction can be guaranteed; meanwhile, by limiting the length dimension a'of the main body relative to the width dimension b 'of the main body, the length dimension a' of the main body can be prevented from being too small, so that the pole has a relatively large length dimension, and the overcurrent capability of the pole can be further improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, in particular to a cover plate assembly, a battery cell and a battery. BACKGROUND

[0002] The single battery includes a shell, a cover plate assembly covering the shell, and an electrode assembly arranged in the shell. The cover plate assembly includes a cover plate, a pole post arranged on the cover plate, an upper plastic part insulating and separating the upper end of the pole post from the top end of the cover plate, and a lower plastic part insulating and separating the cover plate from the electrode assembly and the lower end of the pole post. The electrode assembly is connected to the lower end of the pole post through a tab. The upper end of the pole post is connected to a connecting row, so that a plurality of single batteries can be connected in series or parallel through the connecting row.

[0003] Generally, in order to ensure the overcurrent capacity of the single battery and improve the welding operability between the pole post and the corresponding components, the size of the pole post is set to be relatively large. However, in the square single battery, since the cover plate is a rectangular plate, the width dimension of the cover plate is limited, so that the width dimension of the pole post is also limited. Therefore, the overcurrent capacity of the pole post is poor. SUMMARY

[0004] Embodiments of the present application provide a cover plate assembly, a battery cell and a battery, which can improve the overcurrent capacity of the pole post.

[0005] In a first aspect, embodiments of the present application provide a cover plate assembly, which includes a cover plate and a pole post; the cover plate is provided with a mounting hole, and has a width dimension W and a length dimension L; the pole post includes a main body, one end of the main body is provided with a tab connecting groove, the main body is arranged in the mounting hole, along the direction of the width dimension W, the main body has a width dimension b', and along the direction of the length dimension L, the main body has a length dimension a'; wherein, W-6mm≤b'≤W-8mm, and 0.4≤b' / a'≤0.9.

[0006] In an embodiment, along the direction of the width dimension W, the tab connecting groove has a width dimension d, and along the direction of the length dimension L, the tab connecting groove has a length dimension c, which satisfies: 0.4≤d / c≤0.9.

[0007] In an embodiment, d / c=b' / a'.

[0008] In an embodiment, the thickness of the groove wall of the tab connecting groove is D, which satisfies: 0.8mm≤D≤1.5mm.

[0009] In an embodiment, the pole post further includes a flange, the pole post has a first end configured to face the electrode assembly of the battery cell, the flange is arranged on the outer circumferential surface of the main body and is arranged adjacent to the first end, and the flange is in abutting cooperation with the cover plate.

[0010] In an embodiment, the flange extends circumferentially along the pole post in an annular shape.

[0011] In an embodiment, the flange has a width dimension b along a direction in which the width dimension W lies, and a length dimension a along a direction in which the length dimension L lies, and the following condition is satisfied: 0.4≤a / b≤0.9.

[0012] In an embodiment, a / b=b’ / a’.

[0013] In an embodiment, the flange has a width dimension e along a radial direction of the mounting hole, and the following condition is satisfied: 1.5mm≤e≤2mm.

[0014] In an embodiment, the cover plate assembly further comprises a lower plastic part, the lower plastic part comprising a body, one side of the body being connected to one side of the cover plate, the body being provided with a first through hole, and the main body being arranged to pass through the first through hole.

[0015] In an embodiment, the body has a first surface facing away from the cover plate, and a support structure is outwardly protruding from the first surface, the support structure being arranged adjacent to the pole post and configured to abut against the tab of the battery cell along the axis of the mounting hole.

[0016] In an embodiment, the body has two first long sides parallel to the direction in which the length dimension L lies, and the support structure is arranged at least at a position of the body close to one of the first long sides; the support structure comprises two support portions, and the two support portions are symmetrically distributed along the axis of the first through hole.

[0017] In an embodiment, one end of each of the two support portions is located on one side of the first through hole along the direction in which the length dimension L lies, and the other end of each of the two support portions is located between the first long side adjacent to it and the first through hole along the direction in which the width dimension W lies.

[0018] In an embodiment, the support structure is arranged at positions of the body close to both of the first long sides, and the first surface is further provided with two connecting portions, each of which is located on one side of the first through hole along the direction in which the length dimension L lies; the two ends of each of the connecting portions are connected to the support portions adjacent to it.

[0019] In an embodiment, the support structure protrudes from the first surface by a height dimension H1, and the following condition is satisfied: 0.2mm≤H1≤1.2mm.

[0020] In an embodiment, the first surface is outwardly protruding at a position close to its periphery and provided with a reinforcing platform.

[0021] In an embodiment, the body has a second surface opposite to the first surface, and a groove is arranged at a position of the second surface opposite to the reinforcing platform, a plurality of reinforcing ribs are arranged in the groove in a longitudinal and transverse manner, and a plurality of drainage through holes are arranged at the groove bottom.

[0022] In an embodiment, the two polar posts and the two mounting holes are matched with each other, and the lower plastic part includes two bodies arranged side by side along the direction of the length dimension L, and the first through holes of the two bodies are matched with the two polar posts, respectively; or, the body is provided with two first through holes, the support structure has two, and the two first through holes are matched with the two polar posts, respectively.

[0023] In an embodiment, the cover plate assembly further includes a pressing block, an upper plastic part, and a sealing ring, the pressing block is sleeved on one end of the polar post away from the tab connecting groove and located on one side of the cover plate, the upper plastic part is sleeved on the polar post and located between the pressing block and the cover plate, and the sealing ring is sleeved on the polar post to seal the space between the polar post and the cover plate.

[0024] In a second aspect, the embodiments of the present application provide an electric core, which includes a shell, an electrode assembly, a tab group, and the aforementioned cover plate assembly; the shell has a receiving cavity; the electrode assembly is arranged in the receiving cavity; the cover plate assembly is covered with the shell; one end of the tab group is connected with the electrode assembly, and the other end is located in the tab connecting groove and connected with the inner wall of the tab connecting groove.

[0025] In a third aspect, the embodiments of the present application provide a battery, which includes a box assembly and the aforementioned electric core; the box assembly has a mounting cavity; the electric core has a plurality of electric cores arranged in the mounting cavity and connected in series and / or in parallel.

[0026] The embodiments of the present application have the following beneficial effects:

[0027] In the embodiments of the present application, by limiting the width dimension b' of the main body relative to the width dimension W of the cover plate, the main body can have a larger width dimension, and the strength of the cover plate in the width direction can be ensured; at the same time, by limiting the length dimension a' of the main body relative to the width dimension b' of the main body, the length dimension a' of the main body can be prevented from being too small, so that the polar post can have a larger length dimension, and the overcurrent capacity of the polar post can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0029] Figure 1 FIG. 1 is a structural schematic diagram of a cover plate assembly provided by an embodiment of the present application;

[0030] Figure 2is another perspective view of the cover plate assembly provided by an embodiment of the present application;

[0031] Figure 3 is a partial top view of the cover plate assembly provided by an embodiment of the present application;

[0032] Figure 4 is a partial bottom view of the cover plate assembly provided by an embodiment of the present application;

[0033] Figure 5 is Figure 3 is a sectional view of A-A in FIG. 1;

[0034] Figure 6 is a position diagram of the tab group and the support structure provided by an embodiment of the present application;

[0035] Figure 7 is a partial structural diagram of the cover plate assembly provided by an embodiment of the present application;

[0036] Figure 8 is Figure 7 is an enlarged view of B in FIG. 2;

[0037] Figure 9 is a sectional view of the support structure provided by an embodiment of the present application;

[0038] Figure 10 is a partial structural diagram of the lower plastic part provided by an embodiment of the present application;

[0039] Figure 11 is a structural diagram of the battery cell provided by an embodiment of the present application.

[0040] Explanation of Reference Signs:

[0041] 1 - lower plastic part;

[0042] 11 - body; 111 - first long side; 12 - first surface; 13 - first through hole; 14 - support structure; 141 - support part; 143 - connecting part; 15 - connecting structure; 16 - second surface; 17 - reinforcing platform; 18 - groove; 181 - liquid drainage through hole; 19 - reinforcing rib;

[0043] 2 - cover plate assembly; 21 - cover plate; 22 - pole post; 221 - tab connecting groove; 222 - main body; 223 - flange; 224 - first end; 23 - pressing block; 24 - upper plastic part; 25 - sealing ring;

[0044] 3 - single battery cell; 31 - shell; 32 - electrode assembly; 33 - tab group. DETAILED DESCRIPTION

[0045] With reference to the drawings and the embodiments described herein, it will be understood that the application is not limited in its application to the details of construction, the arrangements of the components, and the arrangement of the steps set forth in the description or illustrated in the drawings. The application is capable of other embodiments and of being practiced or being carried out in various ways. Examples of the technical schemes in the embodiments of the present application will be clearly and completely described in the present application, and obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0046] In addition, it should be understood that the specific implementations described herein are merely examples of implementations and do not limit the application. In the present application, the terms "first", "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second" can be explicitly or implicitly included one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified and limited.

[0047] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, it can be the internal communication of two elements or the interaction relationship between 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.

[0048] The terms "including", "containing" or any other variants thereof are intended to cover non-exclusive inclusion, so that the product including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or includes elements inherent to such product.

[0049] In the description of the embodiments of the present application, the words "example" or "for example" are used to mean example, illustration, or description. Any embodiment or design scheme described as "example" or "for example" in the embodiments of the present application is not interpreted as more preferred or having more advantages than another embodiment or design scheme. The use of "example" or "for example" and the like is intended to present the relative concept in a clear manner.

[0050] Please refer to Figures 1 to 3 , Figure 1 is a structural schematic diagram of the cover plate assembly 2 provided by the embodiments of the present application, Figure 2 is a structural schematic diagram of the cover plate assembly 2 provided by the embodiments of the present application from another perspective, Figure 3is a part of the top view provided by the embodiments of the present application. The embodiments of the present application provide a cover plate assembly 2. The cover plate assembly 2 comprises a cover plate 21 and a pole 22. The cover plate 21 is provided with a mounting hole. The cover plate 21 has a width dimension W and a length dimension L. The pole 22 comprises a main body 222. One end of the main body 222 is provided with a tab connecting groove 221. The main body 222 is arranged in the mounting hole. In the direction along the width dimension W, the main body 222 has a width dimension b'. In the direction along the length dimension L, the main body 222 has a length dimension a'. W-6mm≤b'≤W-8mm, and 0.4≤b' / a'≤0.9.

[0051] The ratio between the width dimension b' and the length dimension a' includes but is not limited to 0.4, 0.44, 0.48, 0.5, 0.52, 0.55, 0.58, 0.6, 0.63, 0.65, 0.68, 0.7, 0.74, 0.76, 0.78, 0.8, 0.82, 0.85, 0.88, 0.9.

[0052] In addition, the width dimension b' of the main body 222 includes but is not limited to W-6mm, W-6.2mm, W-6.4mm, W-6.5mm, W-6.6mm, W-6.7mm, W-638mm, W-7mm, W-7.2mm, W-7.5mm, W-7.6mm, W-7.7mm, W-7.8mm, W-8mm.

[0053] It can be understood that the cover plate 21 is a rectangular plate structure, which is applied to a square battery cell.

[0054] It can be understood that the length dimension a' of the pole 22 is selected based on the basic requirement that the installation of the pole 22 does not interfere with other components and affect assembly. For example, when one pole 22 is arranged on the cover plate 21, the length dimension L of the cover plate 21 can be larger, or the length dimension a' of the pole 22 can be larger; when two poles 22 are arranged on the cover plate 21, the length dimension L of the cover plate 21 can be larger, or the length dimension a' of the pole 22 can be smaller. In addition, when a liquid injection hole and an explosion-proof valve mounting hole are also arranged on the cover plate 21, the length dimension L of the cover plate 21 or the length dimension a' of the pole 22 should be adjusted accordingly.

[0055] It can be understood that the cover plate assembly 2 can further comprise a sealing ring 25 and an upper plastic part 24. Therefore, the difference between the width dimension W of the cover plate 21 and the width dimension b' of the subject can ensure the strength of the cover plate 21 after the mounting hole is arranged, so as to avoid deformation of the cover plate 21 during assembly or use; on the other hand, it can reserve installation space for the upper plastic part 24 and the sealing ring 25.

[0056] It can be understood that the pole column 22 is a square pole column 22, and the corners of the pole column 22 are chamfered, and the chamfer radius is 0.1-2 mm.

[0057] In the embodiment, by limiting the width dimension b' of the main body 222 relative to the width dimension W of the cover plate 21, the main body 222 can have a larger width dimension, and the strength of the cover plate 21 in the width direction can be ensured; meanwhile, by limiting the length dimension a' of the main body 222 relative to the width dimension b' of the main body 222, on the one hand, the length dimension a' of the main body 222 can be prevented from being too small, so that the pole column 22 can have a larger length dimension, and the flow capacity of the pole column 22 can be improved, and on the other hand, the length dimension a' of the main body 222 can be prevented from being too large to affect the arrangement of other components on the cover plate 21, and the strength of the cover plate 21 in the length direction can be ensured.

[0058] Moreover, by limiting the length dimension a' of the main body 222 relative to the width dimension b' of the main body 222, the pole column 22 can have a suitable length dimension, so that the width dimension of the tab connected thereto can be larger. In this way, the current collecting capacity of the battery cell can be improved, and the operability of the welding of the tab and the pole column 22 can be improved.

[0059] Please refer to Figure 4 , Figure 4 is a part of the bottom view of the cover plate assembly 2 provided by the embodiment of the present application. In an embodiment, along the direction in which the width dimension W is located, the tab connecting groove 221 has a width dimension d, and along the direction in which the length dimension L is located, the tab connecting groove 221 has a length dimension c, and 0.4≤d / c≤0.9 is satisfied. In this way, the tab connecting groove 221 has a suitable width-length ratio, so that the stability of the cooperation between the tab connecting groove 221 and the tab can be improved, and the welding of the tab and the tab connecting groove 221 can be facilitated.

[0060] It can be understood that the direction in which the length dimension c is located is parallel to the direction in which the width dimension of the tab is located; and the direction in which the width dimension d is located is consistent with the direction in which the height dimension of the part of the tab located in the tab connecting groove 221 is located.

[0061] The ratio of the width dimension d to the length dimension c includes but is not limited to 0.4, 0.44, 0.48, 0.5, 0.52, 0.55, 0.58, 0.6, 0.63, 0.65, 0.68, 0.7, 0.74, 0.76, 0.78, 0.8, 0.82, 0.85, 0.88, 0.9.

[0062] In an embodiment, d / c=b' / a', so that the uniformity of the structure of the pole column 22 can be improved, and the stress state of the pole column 22 can be improved.

[0063] Please refer to Figure 5 ,Figure 5 is Figure 3 A-A is a sectional view. In an embodiment, the thickness of the slot wall of the tab connecting slot 221 is D, which satisfies: 0.8mm≤D≤1.5mm.

[0064] In an embodiment, the thickness D of the slot wall of the tab connecting slot 221 includes but is not limited to 0.8mm, 0.85mm, 0.8mm, 0.92mm, 0.86mm, 1mm, 1.1mm, 1.2mm, 1.25mm, 1.3mm, 1.35mm, 1.4mm, 1.46mm, 1.5mm.

[0065] In the present embodiment, by limiting the thickness D of the slot wall of the tab connecting slot 221, on the one hand, the strength of the slot wall of the tab connecting slot 221 can be guaranteed, and the deformation of the pole column 22 can be avoided; on the other hand, the tab connecting slot 221 can have a larger size, so that not only the size of the tab cooperating therewith can be improved, but also the operability of the tab welded therewith can be improved.

[0066] Please refer to Figure 5 In an embodiment, the pole column 22 further comprises a flange 223. The pole column 22 has a first end 224 configured to face the electrode assembly of the battery cell. The flange 223 is arranged on the outer circumferential surface of the main body 222 and is arranged adjacent to the first end 224. The flange 223 is in abutting cooperation with the cover plate 21. In this way, when the internal pressure of the battery cell is high, based on the abutting cooperation between the flange 223 and the cover plate 21, the pole column 22 can be effectively prevented from being pulled out of the cover plate 21.

[0067] In addition, when the cover plate assembly 2 further comprises a lower plastic part 1, the flange 223 overlaps the lower plastic part 1, and the part of the lower plastic part 1 close to the pole column 22 is located between the flange 223 and the cover plate 21. In this way, the lower plastic part 1 can be fixed by the flange 223 to improve the reliability of the fixation of the lower plastic part 1.

[0068] Please refer to Figure 2 or Figure 4 In an embodiment, the flange 223 extends along the circumference of the pole column 22 in a ring shape. In this way, not only the uniformity of the structure of the pole column 22 can be improved, but also the stress state of the pole column 22 can be improved; and the stress uniformity of the abutting cooperation part between the pole column 22 and the cover plate 21 can be improved, so that the stress state of the cover plate assembly 2 can be improved.

[0069] Please refer to Figure 4 In an embodiment, along the direction in which the width dimension W is located, the outer edge of the flange 223 has a width dimension b, and along the direction in which the length dimension L is located, the outer edge of the flange 223 has a length dimension a, which satisfies: 0.4≤a / b≤0.9. In this way, the flange 223 has a suitable width-length ratio to improve the stability of the abutting cooperation between the flange 223 and the cover plate 21, and the amount of material of the flange 223 can be controlled.

[0070] The ratio of the width dimension b to the length dimension a includes, but is not limited to, 0.4, 0.44, 0.48, 0.5, 0.52, 0.55, 0.58, 0.6, 0.63, 0.65, 0.68, 0.7, 0.74, 0.76, 0.78, 0.8, 0.82, 0.85, 0.88, 0.9.

[0071] In an embodiment, a / b = b' / a', so that the uniformity of the structure of the pole 22 can be improved to improve the stress state of the pole 22.

[0072] Referring to Figure 3 Or Figure 5 In an embodiment, the width dimension e of the flange 223 along the radial direction of the mounting hole satisfies 1.5mm≤e≤2mm.

[0073] The width dimension e of the flange 223 includes, but is not limited to, 1.5mm, 1.6mm, 1.65mm, 1.7mm, 1.76mm, 1.8mm, 1.83mm, 1.9mm, 1.95mm, 1.98mm, 2mm.

[0074] In the embodiment, by limiting the width dimension e of the 1.5mm flange 223, on the one hand, the size of the flange 223 can be prevented from being too large to interfere with the shell or the insulation gap being insufficient; on the other hand, the flange 223 can have a sufficient width dimension, so that the reliability of the stop cooperation of the flange 223 and the cover plate 21 can be improved.

[0075] Referring to Figure 2 In an embodiment, the cover plate assembly 2 further includes a lower plastic part 1. The lower plastic part 1 includes a body 11. One side of the body 11 is connected to one side of the cover plate 21. The body 11 is provided with a first through hole 13. The main body 222 also penetrates the first through hole 13.

[0076] It can be understood that the flange 223 overlaps with the side of the lower plastic part 1 away from the cover plate 21.

[0077] In the embodiment, by providing the lower plastic part 1, the insulation between the cover plate 21 and the electrode assembly of the battery cell can be improved, so that the reliability of the battery cell can be improved.

[0078] Referring to Figure 2 In an embodiment, the body 11 has a first surface 12 away from the cover plate 21, and a support structure 14 is outwardly protruding from the first surface 12, the support structure 14 is arranged adjacent to the pole 22, and the support structure 14 is configured to abut the tab of the battery cell along the axis of the mounting hole.

[0079] It can be understood that, in order to facilitate the insertion of the end of the tab group into the tab connecting groove 221, the tab is a trapezoidal tab, the width of which gradually increases as it approaches the tab sheet. Therefore, when welding, the end of the tab group away from the tab sheet is small in size, which is located in the tab connecting groove 221, as shown in Figure 6 Figure 6 is a schematic view of the position of the tab group and the support structure 14 provided by the embodiment of the present application. Correspondingly, the part of the tab group located outside the first through hole 13 is supported by the support structure 14.

[0080] In the present embodiment, by providing the support structure 14, when welding the tab group and the pole 22, the support structure 14 can be used to support the tab group, so as to reduce the deformation of the tab group, thereby improving the flatness of the contact part between the tab and the pole 22, and finally improving the welding reliability between the tab group and the pole 22.

[0081] Please refer to Figure 7 , Figure 7 is a schematic view of the partial structure of the cover plate assembly 2 provided by the embodiment of the present application. In an embodiment, the body 11 has two first long edges 111 parallel to the direction in which the length dimension L is located, and at least the part of the body 11 close to one of the first long edges 111 is provided with a support structure 14; the support structure 14 includes two support parts 141, which are symmetrically distributed along the axis of the first through hole 13.

[0082] It can be understood that the tab groups of some square battery cells are bent in the same direction, i.e., the tab groups are located on one side of the lower plastic part 1 in the width direction; correspondingly, the support structure 14 is arranged on the part of the body 11 close to one of the first long edges 111.

[0083] It can be understood that there are two tab groups of some square battery cells, and the two groups are bent in opposite directions; correspondingly, the support structure 14 is arranged on the part of the body 11 close to both of the first long edges 111. The two support structures 14 respectively support the two tab groups.

[0084] In the present embodiment, by providing two support parts 141 and making the two support parts 141 symmetrically distributed along the center line of the first through hole 13, the tab group can be symmetrically supported by the support force from the support structure 14, so as to improve the stress state of the tab group, thereby effectively reducing the deformation of the tab during welding, and further effectively improving the area of the contact surface between the tab group and the pole 22.

[0085] Please refer to Figure 8 , Figure 8 is Figure 7 ​Enlarged view of the middle B. In an embodiment, along the direction of the length dimension L, one end of the two support portions 141 is respectively located on the two sides of the first through hole 13, and along the direction of the width dimension W, the other end of the two support portions 141 is located between the first long side 111 adjacent thereto and the first through hole 13. In this way, the supportability of the support portions 141 to the tab group can be improved, and the compactness of each structural layout on the lower plastic part 1 can be improved, so as to control the size of the lower plastic part 1, thereby effectively controlling the manufacturing cost.

[0086] In an embodiment, the first through hole 13 is a rectangular hole, and when the corners of the first through hole 13 are rounded, the part of the support portion 141 opposite to the corner is a circular arc structure.

[0087] Referring to Figure 7 In an embodiment, the support structure 14 is arranged on the body 11 near the two first long sides 111. The first surface 12 is further provided with two connecting portions 143. Along the direction of the length dimension L, the two connecting portions 143 are respectively located on the two sides of the first through hole 13. The two ends of the connecting portion 143 are respectively connected with the support portion 141 adjacent thereto. In this way, the strength of the lower plastic part 1 around the first through hole 13 can be improved to improve the deformation of the lower plastic part 1, and the support structure 14 can support the tab with an arbitrary angle of the bevel of the cutting edge to improve the adaptability of the support structure 14.

[0088] Referring to Figure 9 , Figure 9 is a cross-sectional view of the support structure 14 provided by the embodiment of the present application. In an embodiment, the height dimension H1 of the support structure 14 protruding from the first surface 12 satisfies: 0.2mm≤H1≤1.2mm.

[0089] In an embodiment, the height dimension H1 of the support structure 14 protruding from the first surface 12 includes but is not limited to 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.62mm, 0.68mm, 0.7mm, 0.72mm, 0.75mm, 0.8mm, 0.85mm, 0.9mm, 1mm, 1.1mm, 1.2mm.

[0090] Exemplarily, the height dimension H1 of the support structure 14 protruding from the first surface 12 is 0.7mm.

[0091] In the embodiment, by limiting the height dimension H1 of the support structure 14 protruding from the first surface 12, on the one hand, the supportability of the support structure 14 to the tab group can be improved, and on the other hand, the height dimension of the battery cell can be reduced, thereby improving the energy density of the battery cell.

[0092] Referring to Figure 7In an embodiment, the first surface 12 further protrudes a connecting structure 15 on one side of the through hole 13, and the connecting structure 15 is configured to be heat-fused with the insulation film of the battery cell. In this way, the lower plastic part 1 can be effectively prevented from being melted through when heat-fused with the insulation film, thereby ensuring the insulation between the cover plate 21 and the internal components of the battery cell.

[0093] Optionally, the connecting structure 15 is located between the first through hole 13 and the first long side 111.

[0094] Referring to Figure 10 , Figure 10 is a partial structural schematic view of the lower plastic part 1 provided by the embodiment of the present application. In an embodiment, the first surface 12 protrudes a reinforcing platform 17 near the periphery thereof. The body 11 has a second surface 16 opposite to the first surface 12. The second surface 16 is provided with a groove 18 opposite to the reinforcing platform 17. The groove 18 is provided with longitudinal and transverse intersecting reinforcing ribs 19, and a plurality of liquid discharge through holes 181 are arranged at the bottom of the groove 18.

[0095] Specifically, the two ends of the first surface 12 protrude the reinforcing platform 17 along the direction of the length dimension L.

[0096] In the embodiment, the reinforcing platform 17 can increase the dimension of the reinforcing ribs 19 in the thickness direction of the lower plastic part 1, thereby increasing the strength of the lower plastic part 1 and improving the structural reliability of the cover plate assembly 2.

[0097] In addition, the liquid discharge through holes 181 can make the electrode liquid flow into the surrounding of the electrode assembly during the liquid injection, thereby improving the liquid injection efficiency.

[0098] It can be understood that, in addition to the liquid discharge through holes 181, the body 11 is further provided with liquid discharge holes opposite to the liquid injection holes of the cover plate 21, and exhaust holes opposite to the explosion-proof valves.

[0099] Referring to Figure 2 In an embodiment, the pole 22 and the mounting hole are both two, and the two poles 22 are respectively matched with the two mounting holes. The lower plastic part 1 includes two bodies 11, and the two bodies 11 are arranged side by side along the direction of the length dimension L. The first through holes 13 of the two bodies 11 are respectively matched with the two poles 22. In this way, the two bodies 11 can be respectively assembled during the assembly, thereby improving the adjustability during the assembly.

[0100] In some other embodiments, there are two polar posts 22 and two mounting holes. The two polar posts 22 are respectively matched with the two mounting holes. The body 11 is provided with two first through holes 13. There are two support structures 14. The two support structures 14 are respectively arranged in one-to-one correspondence with the two first through holes 13, and the two first through holes 13 are respectively matched with the two polar posts 22.

[0101] Referring to Figure 5 In an embodiment, the cover plate assembly 2 further comprises a pressing block 23, an upper plastic part 24 and a sealing ring 25. The pressing block 23 is sleeved on the polar post 22 away from the tab connecting groove 221 and located on one side of the cover plate 21. The upper plastic part 24 is sleeved on the polar post 22 and located between the pressing block 23 and the cover plate 21. The sealing ring 25 is sleeved on the polar post 22 to seal between the polar post 22 and the cover plate 21.

[0102] It can be understood that the pressing block 23 is welded with the polar post 22 to avoid the polar post 22 from falling into the inside of the battery cell; the upper plastic part 24 insulates and separates the pressing block 23 and the cover plate 21. Meanwhile, the upper plastic part 24 can also be partially located in the mounting hole to improve the insulation between the polar post 22 and the cover plate 21. The sealing ring 25 can prevent the electrolyte from leaking from the mounting hole.

[0103] Referring to Figure 11 , Figure 11 is a structural schematic diagram of a battery cell provided by an embodiment of the present application. Accordingly, an embodiment of the present application provides a battery cell. The battery cell comprises a shell 31, an electrode assembly 32, a tab group 33 and the aforementioned cover plate assembly 2. The shell 31 has a receiving cavity. The electrode assembly 32 is arranged in the receiving cavity. The cover plate assembly 2 is covered with the shell 31. One end of the tab group 33 is connected with the electrode assembly 32, and the other end is located in the tab connecting groove 221 and connected with the inner wall of the tab connecting groove 221.

[0104] In the embodiment, by adopting the cover plate assembly 2 provided by some embodiments of the present application, on the one hand, the main body 222 can have a larger width dimension while the strength of the cover plate 21 in the width direction can be ensured; on the other hand, the polar post 22 can have a larger length dimension to improve the overcurrent capacity of the polar post 22, and the length dimension a' of the main body 222 can be prevented from being too large to affect the arrangement of other components on the cover plate 21, and the strength of the cover plate 21 in the length direction can be ensured.

[0105] Accordingly, an embodiment of the present application further provides a battery. The battery comprises a box assembly and the aforementioned battery cell. The box assembly has a mounting cavity. There are a plurality of battery cells. The plurality of battery cells are arranged in the mounting cavity, and the plurality of battery cells are connected in series and / or in parallel.

[0106] In the embodiment, by adopting the battery cell provided by some embodiments of the application, the overcurrent capacity of the battery cell can be improved, and the structural strength can be ensured, so that the reliability of the battery is improved.

[0107] The technical solutions and technical effects of the application are described in detail below through specific embodiments. The following embodiments are only some embodiments of the application, and do not specifically limit the application. The embodiment is intended to investigate the strength of the cover plate 21 and the overcurrent capacity of the pole 22.

[0108] The test contents of the embodiments are described in detail as follows.

[0109] I. Test-related Description

[0110] (I) Related parameters of test objects

[0111] 1. Cover plate 21

[0112] Material of the cover plate 21: aluminum alloy;

[0113] Width size W of the cover plate 21: 36 mm;

[0114] Length size L of the cover plate 21: 175 mm;

[0115] Thickness size D of the cover plate 21: 2 mm.

[0116] 2. Pole 22

[0117] Material of the pole 22: aluminum material;

[0118] Height size h of the pole 22: 3.2 mm.

[0119] Width size b': 30 mm;

[0120] Length size a' is 30 / 0.9-30 / 0.4=33.3-75 mm.

[0121] a' is sequentially selected as 33.3 mm, 45 mm, 60 mm and 75 mm as test group one, test group two, test group three and test group four.

[0122] (II) Control group

[0123] The control group one, the control group two and the control group three are different from the test group in the length of the pole 22 and the length of the mounting hole on the cover plate 21 corresponding to the length of the pole 22, and the rest of the parameters are consistent.

[0124] II. Test results

[0125] The cover plate 21 pressure strength test and the pole 22 overcurrent capacity test are performed on the test group and the control group, and the test data are as follows:

[0126]

[0127]

[0128] Table 1. Test control table

[0129] As can be seen from Table 1, under the premise that the width dimension b' of the pole 22 is constant, the greater the length dimension a' of the pole 22, the stronger the flow capacity of the pole 22. Meanwhile, the greater the length dimension a' of the pole 22, the worse the pressure bearing capacity of the cover plate 21. In addition, the greater the length dimension a' of the pole 22, the arrangement of the explosion-proof valve mounting hole and the liquid injection hole on the cover plate 21 is affected, and the design difficulty and manufacturing difficulty are increased. Therefore, the cover plate assembly 2 provided by the embodiments of the present application can not only ensure the flow capacity of the pole 22, but also ensure the strength of the cover plate 21, so that the cover plate 21 has a suitable pressure bearing capacity.

[0130] The above has introduced the embodiments of the present application in detail, and the specific examples have been applied to describe the principles and implementation modes of the present application. The above description of the embodiments is only used to help understand the method of the present application and its core idea; meanwhile, for those skilled in the art, according to the idea of the present application, the specific implementation mode and application range will be changed, and the above description of the present application should not be understood as a limitation.

Claims

1. A cover assembly, characterized by The application relates to a cover plate assembly for a battery cell, comprising: a cover plate provided with a mounting hole, the cover plate having a width dimension W and a length dimension L; a pole including a main body, one end of the main body being provided with a tab connecting groove, the main body being arranged in the mounting hole, the main body having a width dimension b' along the direction of the width dimension W and a length dimension a' along the direction of the length dimension L; wherein W-6mm<=b'<=W-8mm and 0.4<=b' / a'<=0.

9.

2. The cover plate assembly of claim 1, wherein, The tab connecting groove has a width dimension d along the direction of the width dimension W and a length dimension c along the direction of the length dimension L, and 0.4<=d / c<=0.9 is satisfied.

3. The cover plate assembly of claim 2, wherein, d / c=b' / a'.

4. The cover plate assembly of claim 2, wherein, The thickness of the groove wall of the tab connecting groove is D, and 0.8mm<=D<=1.5mm is satisfied.

5. The cover plate assembly of any one of claims 1-4, wherein, The pole further includes a flange, the pole has a first end configured to face an electrode assembly of a battery cell, the flange is arranged on the outer circumferential surface of the main body and is adjacent to the first end, and the flange is in abutting cooperation with the cover plate.

6. The cover plate assembly of claim 5, wherein, The flange extends in a ring shape along the circumferential direction of the pole.

7. The cover plate assembly of claim 6, wherein, The outer edge of the flange has a width dimension b along the direction of the width dimension W and a length dimension a along the direction of the length dimension L, and 0.4<=a / b<=0.9 is satisfied.

8. The cover plate assembly of claim 7, wherein, a / b=b' / a'.

9. The cover plate assembly of claim 5, wherein, The flange has a width dimension e along the radial direction of the mounting hole, and 1.5mm<=e<=2mm is satisfied.

10. The cover plate assembly of any one of claims 1-4, wherein, The cover plate assembly further includes a lower plastic part, the lower plastic part includes a body, one side of the body is connected with one side of the cover plate, the body is provided with a first through hole, and the main body is further arranged in the first through hole.

11. The cover plate assembly of claim 10, wherein, The body has a first surface away from the cover plate, a support structure is outwardly protruded from the first surface, the support structure is adjacent to the pole, and the support structure is configured to abut against the tab of a battery cell along the axis of the mounting hole.

12. The cover plate assembly of claim 11, wherein, The body has two first long edges parallel to the direction of the length dimension L, and the support structure is arranged at least at a position of the body close to one of the first long edges; the support structure includes two support portions, and the two support portions are symmetrically distributed along the axis of the first through hole.

13. The cover plate assembly of claim 12, wherein, One end of the two support portions is respectively located on the two sides of the first through hole along the direction of the length dimension L, and the other end of the two support portions is located between the first long edge adjacent to the other end and the first through hole along the direction of the width dimension W.

14. The cover plate assembly of claim 12, wherein, The support structure is arranged at positions of the body close to the two first long edges, and the first surface is further provided with two connecting portions, the two connecting portions are respectively located on the two sides of the first through hole along the direction of the length dimension L; and the two ends of the connecting portion are respectively connected with the support portions adjacent to the two ends.

15. The cover plate assembly of any one of claims 11-14, wherein, The height dimension of the support structure protruded from the first surface is H1, and 0.2mm<=H1<=1.2mm is satisfied.

16. The cover plate assembly of any one of claims 11-14, wherein, The first surface is outwardly protruded at a position close to the periphery of the first surface.

17. The cover plate assembly of claim 16, wherein, The body has a second surface opposite to the first surface, and a groove is arranged at a position opposite to the reinforcing platform, and longitudinal and transverse intersecting reinforcing ribs are arranged in the groove, and a plurality of drainage through holes are arranged at the groove bottom.

18. The cover plate assembly of any one of claims 11-14, wherein, The pole and the mounting hole are both two, and the two poles are matched with the two mounting holes respectively; Wherein, The lower plastic part includes two bodies, and the two bodies are arranged side by side along the direction of the length dimension L, and the first through holes of the two bodies are matched with the two poles respectively. Or, The body is provided with two first through holes, the support structure is two, and the two support structures are arranged one by one corresponding to the two first through holes respectively, and the two first through holes are matched with the two poles respectively.

19. The cover plate assembly of any one of claims 1-4, wherein, The cover plate assembly further includes a pressing block, an upper plastic part and a sealing ring, the pressing block is sleeved on one end of the pole away from the tab connecting groove and located on one side of the cover plate, the upper plastic part is sleeved on the pole and located between the pressing block and the cover plate, and the sealing ring is sleeved on the pole to seal between the pole and the cover plate.

20. An electric cell, characterized by Including: The shell has a containing cavity; The electrode assembly is arranged in the containing cavity; The cover plate assembly as claimed in any one of claims 1-19 is covered with the shell; The tab group is connected with the electrode assembly at one end and located in the tab connecting groove and connected with the inner wall of the tab connecting groove at the other end.

21. A battery, characterized by Including: The box assembly has a mounting cavity; And the battery cell as claimed in claim 20, the battery cell is multiple, and the multiple battery cells are arranged in the mounting cavity and connected in series and / or parallel.

Images