Pole, cover plate assembly and single battery

Abstract

The invention provides a pole, a cover plate assembly and a single battery, and relates to the technical field of batteries. The pole comprises a body, the body is provided with a first surface, and the first surface is provided with a tab welding groove; the tab welding groove is provided with a groove side wall, the groove side wall is configured to be in contact with the tab of the single battery, and the plane where the groove side wall is located gradually inclines towards the axis of the pole along the direction far away from the first surface. According to the scheme, the bending angle of the tab when the tab is in contact with the groove side wall can be reduced, so that obvious stress concentration at the bending part of the tab is avoided, and cracks and even fractures at the bending part of the tab can be effectively avoided. Therefore, the structural integrity of the tabs can be ensured, so that the current-carrying capacity of the tabs is improved, the overcurrent capacity between the tabs and the pole columns is improved, and the performance of the single battery can be further improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a pole, a cover plate assembly and a single cell. Background Art

[0002] A single cell includes a shell, an electrode assembly disposed in the shell, and a pole disposed on the shell. In the related art, in order to improve the energy density of a single cell, the electrode assembly is directly connected to the pole through a pole lug. The connection method between the pole and the pole lug has an important influence on the performance of the single cell.

[0003] In the related art, the solution of connecting the tabs and the poles to each other has some shortcomings, which leads to poor performance of the single battery. Summary of the invention

[0004] The embodiments of the present application provide a pole, a cover plate assembly and a single cell, which can improve the performance of the single cell.

[0005] In a first aspect, an embodiment of the present application provides a pole, which includes a body, the body having a first surface, and the first surface is provided with a pole ear welding groove; the pole ear welding groove has a groove side wall, and the groove side wall is configured to contact the pole ear of the single cell, and along the direction away from the first surface, the plane where the groove side wall is located gradually inclines toward the axis of the pole.

[0006] In one embodiment, along a direction perpendicular to the axis of the pole, the pole tab welding groove passes through one end or both ends of the body.

[0007] In one embodiment, in any two cross sections perpendicular to the extension direction of the electrode tab welding groove, the cross sections of the electrode tab welding groove have the same shape and size.

[0008] In one embodiment, there are two slot side walls, and the two slot side walls are centrally symmetrically distributed along the axis of the pole.

[0009] In one embodiment, two groove side walls are connected to each other at one side away from the groove opening of the tab welding groove.

[0010] In one embodiment, a first chamfer is provided at the connection between the groove side wall and the first surface, and the first chamfer is a rounded chamfer with a radius ranging from 15 to 30 mm.

[0011] In one embodiment, the tab welding groove further includes a groove bottom wall, and one side of two groove side walls away from the groove opening of the tab welding groove is connected to the groove bottom wall.

[0012] In one embodiment, a second chamfer is provided at the connection between the groove side wall and the groove bottom wall, and the second chamfer is a rounded chamfer with a radius ranging from 5 to 15 mm.

[0013] In one embodiment, a third chamfer is provided at the connection between the groove side wall and the first surface, and the third chamfer is a rounded chamfer with a radius ranging from 10 to 20 mm.

[0014] In one embodiment, the angle between the plane where the slot side wall is located and the axis of the pole is an angle α, which satisfies: 30°≤α≤65°.

[0015] In one embodiment, an extension portion is disposed on the outer peripheral surface of the body, the extension portion is disposed close to the first surface, and the extension portion is located on one side of the groove side wall.

[0016] In one embodiment, there are two slot side walls, which are symmetrically distributed along the axis of the pole, and there are two extension parts, which correspond one to one to the two slot side walls.

[0017] In a second aspect, an embodiment of the present application provides a cover plate assembly, which includes a cover plate and the aforementioned pole; the pole is disposed on the cover plate.

[0018] On the third aspect, an embodiment of the present application provides a single cell battery, which includes a shell, an electrode assembly, a pole ear and the aforementioned cover assembly; the cover assembly covers the shell to close the accommodating cavity; the shell has an accommodating cavity; the electrode assembly is arranged in the accommodating cavity; one end of the pole ear is connected to the electrode assembly, and the other end of the pole ear extends into the pole ear welding groove, and the pole ear is in contact with the side wall of the groove.

[0019] In one embodiment, along a direction perpendicular to the axis of the pole, the length dimension of the pole tab welding groove is L1, and the length dimension of the pole tab is L2, satisfying: L1>L2.

[0020] Beneficial effects of the embodiments of the present application:

[0021] In the embodiment of the present application, by limiting the slot sidewall in contact with the pole tab to be inclined toward the axis of the pole column, the bending angle of the pole tab when in contact with the slot sidewall can be reduced to avoid obvious stress concentration at the bending part of the pole tab, thereby effectively avoiding cracks or even fractures at the bending part of the pole tab. In this way, the structural integrity of the pole tab can be ensured to improve the current carrying capacity of the pole tab, enhance the current flow capacity between the pole tab and the pole column, and thus enhance the performance of the single cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0023] Figure 1is a schematic diagram of the structure of a pole provided in an embodiment of the present application;

[0024] Figure 2 is a schematic diagram of a cross section of a pole provided in an embodiment of the present application in a direction perpendicular to the extension direction of a pole lug welding groove;

[0025] Figure 3 It is a schematic diagram of the matching of the pole and the pole ear provided in the embodiment of the present application;

[0026] Figure 4 yes Figure 3 The enlarged view of point A in the middle;

[0027] Figure 5 is a schematic diagram of the structure of another pole provided in an embodiment of the present application;

[0028] Figure 6 is a schematic diagram of the structure of another pole provided in an embodiment of the present application;

[0029] Figure 7 is a schematic structural diagram of another pole provided in an embodiment of the present application;

[0030] Figure 8 The embodiments of this application provide Figure 7 A side view of the pole shown;

[0031] Fig. 9 This application provides Figure 7 The schematic diagram of the matching of the pole and the pole ear shown;

[0032] Fig.10 is a schematic structural diagram of a cover plate assembly provided in an embodiment of the present application;

[0033] Fig.11 is a schematic diagram of the structure of a single cell provided in an embodiment of the present application;

[0034] Fig.12 It is a schematic diagram of the cooperation between the pole and the pole ear in another cross-sectional direction provided by an embodiment of the present application.

[0035] Description of reference numerals:

[0036] 5-pole; 51-body; 52-first surface; 53-ear welding groove; 531-groove side wall; 532-groove bottom wall; 54-extension portion; 55-axis of the pole;

[0037] 2-cover plate assembly; 21-cover plate;

[0038] 3- single cell; 31- shell; 32- electrode assembly; 321- end surface of the electrode assembly facing the pole; 33- pole ear. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of this application.

[0040] In addition, it should be understood that the specific embodiments described herein are only used to illustrate and explain the present application and are not used to limit the present application. In the present application, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0041] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0042] The terms "comprises," "comprising," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a product that includes a list of elements includes not only those elements, but also includes other elements not expressly listed or that are inherent to such product.

[0043] In the description of the embodiments of the present application, words such as "example" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "example" or "for example" in the embodiments of the present application is not to be interpreted as being more preferred or having more advantages than another embodiment or design. The use of words such as "example" or "for example" is intended to present relative concepts in a clear manner.

[0044] To facilitate understanding of the solution of the present application, prior to introducing a pole, a cover plate assembly and a single cell provided by the present application, the relevant technologies of the present application are first described.

[0045] In the related art, a single cell includes a shell, an electrode assembly disposed in the shell, and a pole disposed on the shell. In order to improve the energy density of the single cell, the electrode assembly is directly connected to the pole through the pole ear. Although this connection method can improve the energy density of the single cell, it requires the pole ear to be bent at least once, and the bending angle is large. Since the pole ear is a foil material, it is easy to break when bent. This has an adverse effect on the overcurrent between the pole ear and the pole, which will affect the performance of the single cell.

[0046] Based on this, the embodiments of the present application provide a pole, a cover plate assembly and a single cell to solve the problem of bending of the pole tab, thereby improving the current flow capacity between the pole tab and the pole to improve the performance of the single cell.

[0047] See also Figure 1 and Figure 2 , Figure 1 is a schematic diagram of the structure of the pole 5 provided in an embodiment of the present application, Figure 2 is a schematic diagram of a cross section of a pole 5 provided in an embodiment of the present application in a direction perpendicular to the extension direction of a pole tab welding groove 53. An embodiment of the present application provides a pole 5, which is applied to a single cell. The pole 5 includes a body 51. The body 51 has a first surface 52. The first surface 52 is provided with a pole tab welding groove 53. The pole tab welding groove 53 has a groove sidewall 531. The groove sidewall 531 is configured to contact the pole tab 33 of the single cell 3. Along the direction away from the first surface 52, the plane where the groove sidewall 531 is located gradually tilts toward the axis of the pole 5.

[0048] The portion of the pole tab 33 located in the pole tab welding groove 53 is parallel to the groove sidewall 531. The pole tab 33 has a length dimension, a width dimension, and a thickness dimension. The width dimension is the extending direction of the portion where the pole tab 33 is connected to the current collector of the pole sheet. Specifically, the direction where the width dimension of the pole tab 33 is located is parallel to the first surface.

[0049] It can be understood that the first surface 52 faces the electrode assembly of the single battery.

[0050] It can be understood that there is an angle α between the plane where the groove sidewall 531 is located and the axis of the pole 5, and the angle α is an acute angle and is located on the side of the first surface 52 away from the electrode assembly. It can be understood that the plane where the groove sidewall 531 is located forms an acute angle α with the axis of the pole 5, and correspondingly, the groove sidewall 531 and the end face of the electrode assembly of the single cell facing the pole 5 form an acute angle β, and the angle β is complementary to the angle α.

[0051] It can be understood that 0<α<90°. Specifically, the angle α includes but is not limited to 10°, 20°, 30°, 35°, 40°, 45°, 50°, 56°, 60°, 65°, 70°, 75°, 80°, and 85°.

[0052] It can be understood that the tab welding groove 53 can be a groove structure, a through groove structure, or a semi-open groove structure with only one end connected to the outside and the other end closed.

[0053] In addition, the tab welding groove 53 can be a V-shaped groove, a trapezoidal groove, or other shapes of the tab welding groove 53. The shape of the bottom wall of the tab welding groove 53 is not limited, and can be a plane bottom wall, a circular arc groove bottom, or a groove bottom of other special-shaped structures.

[0054] like Figure 3 As shown, Figure 3 3 is a schematic diagram of the pole 5 and the pole lug 33 provided in the embodiment of the present application. When the pole 5 is connected to the pole lug 33, multiple layers of pole lugs 33 are stacked to form a pole lug cluster, which extends along the slot sidewall 531 and is inserted into the pole lug welding slot 53. Figure 4 As shown, Figure 4 yes Figure 3 In the enlarged view at point A, in the lug cluster, the lug 33 close to the slot sidewall 531 has a bend, and the bend is relatively small; and as it moves away from the slot sidewall 531, the bending angle of the lug 33 in the lug cluster becomes smaller, that is, the flatness of the lug 33 becomes better.

[0055] In this embodiment, by limiting the groove sidewall 531 in contact with the pole lug 33 to be inclined toward the axis of the pole column 5, the bending angle of the pole lug 33 when in contact with the groove sidewall 531 can be reduced, so as to avoid a relatively obvious stress concentration at the bending part of the pole lug 33, and further effectively avoid cracks or even fractures at the bending part of the pole lug 33. In this way, the structural integrity of the pole lug 33 can be ensured, so as to improve the current carrying capacity of the pole lug 33, and enhance the current passing capacity between the pole lug 33 and the pole column 5, so as to enhance the performance of the single cell 3.

[0056] In addition, by limiting the angle between the slot sidewall 531 in contact with the pole tab and the axis of the pole post 5 to be an acute angle, the pole tab 33 and the slot sidewall 531 can be well fitted, thereby reducing the resistance at the joint between the pole tab 33 and the pole post 5. This can not only improve the current flow capacity between the pole tab 33 and the pole post 5, but also control the temperature rise and improve the performance of the single battery 3.

[0057] See also Figure 5 or Figure 6 , Figure 5 is a schematic diagram of the structure of another pole 5 provided in an embodiment of the present application, Figure 6 is a schematic structural diagram of another pole 5 provided in an embodiment of the present application. In one embodiment, along a direction perpendicular to the axis of the pole 5 , the pole ear welding groove 53 passes through one end or both ends of the body 51 .

[0058] In some embodiments, one end of the tab welding groove 53 may pass through one end of the body 51, such as Figure 5 In some other embodiments, the two ends of the tab welding groove 53 may pass through the two ends of the body 51, such as Figure 6 shown.

[0059] It can be understood that when both ends of the tab welding groove 53 pass through the body 51 in a direction perpendicular to the axis of the pole 5, the length dimension L1 of the tab welding groove 53 in the extension direction of the tab welding groove 53 is equal to the length dimension L3 of the body 51 in the extension direction of the tab welding groove 53.

[0060] In this embodiment, by passing the tab welding groove 53 through one or both ends of the body 51, on the one hand, the size of the tab welding groove 53 can be increased, so that the width of the tab 33 fitted in the tab welding groove 53 can be set larger to improve the current flow capacity between the tab 33 and the pole 5; on the other hand, the convenience of processing the tab welding groove 53 and the ease of operation of welding the tab welding groove 53 and the tab 33 can be improved through the port of the tab welding groove 53 connected to the outside. In this way, the efficiency of processing the pole 5 and the efficiency of welding the pole 5 and the tab 33 can be improved.

[0061] See also Figure 1 or Figure 5 or Figure 6 In one embodiment, in any two cross sections perpendicular to the extension direction of the tab welding groove 53, the cross sections of the tab welding groove 53 have the same shape and size. In this way, the shape of the tab welding groove 53 is regular, which is conducive to reducing the processing difficulty and improving the forming efficiency of the pole 5.

[0062] See also Figure 2 In one embodiment, there are two slot side walls 531. The two slot side walls 531 are centrally symmetrically distributed along the axis of the pole 5. In this way, not only the structure of the pole 5 is symmetrical, the stress state of the pole 5 can be improved, but also the difficulty of connecting the pole lug 33 with the pole 5 can be reduced, so that when the pole lug 33 is welded to the pole 5, the pole lug cluster can be welded to the slot side wall 531 adjacent to it.

[0063] Furthermore, in some embodiments, the pole 5 is welded to two pole lug clusters, the two pole lug clusters are symmetrically distributed along the axis of the pole 5, and the two pole lug clusters can be respectively welded to two slot side walls 531. In this way, there are multiple welding surfaces between the pole lug 33 and the pole 5, thereby enhancing the stability of the connection between the pole 5 and the pole lug clusters.

[0064] See also Figure 2In one embodiment, the two groove side walls 531 are connected to each other at one side away from the notch of the tab welding groove 53. In this way, the tab welding groove 53 is a V-shaped groove, which has a simple structure and is easy to process. It can also make the pole 5 thicker at the part where the tab welding groove 53 is provided, so as to improve the structural strength of the pole 5.

[0065] See also Figure 2 In one embodiment, a first chamfer R1 is provided at the connection between the groove side wall 531 and the first surface 52 , and the first chamfer R1 is a rounded chamfer with a radius ranging from 15 to 30 mm.

[0066] It can be understood that the radius range of the first chamfer R1 includes but is not limited to 15mm, 17mm, 18mm, 19mm, 20mm, 21mm, 22mm, 25mm, 26mm, 28mm, 29mm, and 30mm.

[0067] In this embodiment, by setting the first chamfer R1, on the one hand, the scratching of the pole lug 33 by the turning point at the connection between the groove side wall 531 and the first surface 52 can be improved, thereby improving the stress state of the pole lug 33 and preventing the pole lug 33 from being scratched; on the other hand, the stress on the pole 5 at the connection can be improved, thereby improving the reliability of the pole 5.

[0068] See also Figure 7 and Figure 8 , Figure 7 is a schematic structural diagram of another pole 5 provided in an embodiment of the present application, Figure 8 The embodiments of this application provide Figure 7 5 is a side view of the pole 5 shown in FIG. In one embodiment, the pole tab welding groove 53 further has a groove bottom wall 532. The two groove side walls 531 are connected to the groove bottom wall 532 on one side away from the notch of the pole tab welding groove 53. Specifically, the two groove side walls 531 are respectively connected to the two side edges of the groove bottom wall 532. In this way, the pole tab welding groove 53 is a trapezoidal groove with a notch width larger than a groove bottom width. Optionally, the pole tab welding groove 53 is an isosceles trapezoidal groove.

[0069] In this embodiment, through the above arrangement, on the one hand, two groove side walls 531 can be formed on the pole 5 to facilitate the connection between the pole 5 and the pole lug 33, and on the other hand, the depth dimension of the pole lug welding groove 53 can be controlled, thereby ensuring the overall strength of the pole 5.

[0070] See also Figure 8 In one embodiment, a second chamfer R2 is provided at the connection between the groove side wall 531 and the groove bottom wall 532. The second chamfer R2 is a rounded chamfer with a radius ranging from 5 to 15 mm.

[0071] It can be understood that the radius range of the second chamfer R2 includes but is not limited to 5mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, and 15mm.

[0072] like Fig. 9 As shown, Fig. 9 This application provides Figure 7 The schematic diagram of the pole 5 and the pole lug 33 is shown, and the pole lug cluster is inserted into the pole lug welding groove 53 along the groove side wall 531 and extends to the groove bottom wall 532 along the second chamfer R2.

[0073] In this embodiment, by setting the second chamfer R2, on the one hand, when the pole ear 33 extends from the slot side wall 531 to the slot bottom wall 532, the pole ear 33 can be smoothly bent at the position between the slot side wall 531 and the slot bottom wall 532, thereby improving the stress state of the pole ear 33 and avoiding damage to the pole ear 33 due to too sharp bending; on the other hand, the stress of the pole 5 at the connection point can be improved, thereby improving the reliability of the pole 5.

[0074] In addition, chamfers are mainly provided at the corners of the pole 5 that will contact the pole lug 33. In this way, the pole lug 33 can be bent smoothly to improve the stress concentration at the bending part of the pole lug 33, and the processing cost of the chamfer can be controlled, thereby controlling the manufacturing cost of the pole 5.

[0075] See also Figure 8 In one embodiment, a third chamfer R3 is provided at the connection between the groove side wall 531 and the first surface 52 , and the third chamfer R3 is a rounded chamfer with a radius ranging from 10 to 20 mm.

[0076] It can be understood that the radius range of the third chamfer R3 includes but is not limited to 10mm, 11.5mm, 12mm, 13mm, 14mm, 15mm, 17mm, 18mm, 19mm, and 20mm.

[0077] In this embodiment, by setting the third chamfer R3, on the one hand, the scratching of the pole lug 33 by the turning point at the connection between the groove side wall 531 and the first surface 52 can be improved, thereby improving the stress state of the pole lug 33 and preventing the pole lug 33 from being scratched; on the other hand, the stress on the pole 5 at the connection can be improved, thereby improving the reliability of the pole 5.

[0078] In one embodiment, the angle between the plane where the slot side wall 531 is located and the axis of the pole 5 is α, which satisfies: 30°≤α≤65°.

[0079] Exemplarily, the angle α includes but is not limited to 30°, 32°, 33°, 34°, 35°, 36°, 38°, 40°, 42°, 44°, 45°, 47°, 48°, 50°, 52°, 55°, 56°, 58°, 59°, 60°, 62°, 64°, and 65°.

[0080] In this embodiment, by limiting the angle α, on the one hand, it can be avoided that the angle is too small, which causes the pole lug 33 to be bent at a larger angle in order to fit the slot side wall 531, thereby improving the stress state at the bending point of the pole lug 33, and further effectively avoiding cracks or even breakage of the pole lug 33 at the bending point; on the other hand, it can be avoided that the angle is too large, which causes the overlapping height between the pole lug 33 and the pole 5 to be too small, thereby ensuring the overlapping height between the pole lug 33 and the pole 5 and reducing the height dimension occupied by the pole lug 33.

[0081] See also Figure 7 In one embodiment, an extension portion 54 is disposed on the outer peripheral surface of the body 51 . The extension portion 54 is disposed close to one side of the first surface 52 , and the extension portion 54 is located on one side of the groove sidewall 531 .

[0082] It can be understood that the extension portion 54 and the body 51 are formed integrally.

[0083] In this embodiment, by providing the extension portion 54, on the one hand, it is convenient for the pole lug 33 to cooperate with the end cover of the single cell through the extension portion 54 to prevent the pole 5 from escaping from the end cover; on the other hand, the notch of the pole lug welding groove 53 can be extended toward the extension portion 54. In this way, while increasing the size of the notch, the strength of the pole 5 at the notch can be guaranteed, thereby avoiding deformation of the portion of the pole 5 located at the notch.

[0084] Furthermore, by providing the extension portion 54 , the pole tab 33 can be supported by the extension portion 54 when the pole tab 33 is welded to the pole post 5 , thereby preventing the pole tab 33 from being deformed during welding, thereby improving the reliability of welding between the pole tab 33 and the pole post 5 .

[0085] See also Figure 7 In one embodiment, there are two slot side walls 531. The two slot side walls 531 are centrally symmetrically distributed along the axis of the pole 5. There are two extensions 54. The two extensions 54 correspond to the two slot side walls 531 one by one. In this way, the pole 5 is structurally symmetrical, which can improve the stress state of the pole 5.

[0086] See also Fig.10 , Fig.10 2 is a schematic diagram of the structure of the cover plate 21 assembly 2 provided in the embodiment of the present application. Accordingly, the embodiment of the present application also provides a cover plate 21 assembly 2, which includes a cover plate 21 and a pole 5 disclosed in some embodiments of the present application. The pole 5 is provided on the cover plate 21.

[0087] It can be understood that the cover plate 21 assembly 2 also includes a pressure ring, an upper plastic, a lower plastic and a sealing ring. The pressure ring is located on one side of the cover plate 21 and is sleeved on one end of the pole 5 away from the pole lug welding groove 53. The upper plastic is sleeved on the pole 5 and is located between the pressure ring and the cover plate 21. The lower plastic is arranged on the other side of the cover plate 21. The sealing ring is sleeved on the pole 5 and abuts against the cover plate 21 to seal the mating part between the cover plate 21 and the pole 5.

[0088] In this embodiment, by adopting the pole 5 disclosed in some embodiments of the present application, the bending angle of the pole ear 33 when in contact with the slot side wall 531 can be reduced to avoid a relatively obvious stress concentration at the bending part of the pole ear 33, thereby effectively avoiding cracks or even fractures at the bending part of the pole ear 33. In this way, the structural integrity of the pole ear 33 can be ensured, so as to improve the current carrying capacity of the pole ear 33, enhance the current passing capacity between the pole ear 33 and the pole 5, and thereby enhance the performance of the single cell 3.

[0089] See also Fig.11 , Fig.11 : is a schematic diagram of the structure of a single cell 3 provided in an embodiment of the present application. Accordingly, an embodiment of the present application also provides a single cell 3. The single cell 3 includes a shell 31, an electrode assembly 32, a pole ear 33, and a cover plate 21 assembly 2 disclosed in some embodiments of the present application. The cover plate 21 assembly 2 covers the shell 31 to close the accommodating cavity. The shell 31 has an accommodating cavity. The electrode assembly 32 is disposed in the accommodating cavity. One end of the pole ear 33 is connected to the electrode assembly 32, and the other end of the pole ear 33 extends into the pole ear welding groove 53. The pole ear 33 is in contact with the groove side wall 531.

[0090] In this embodiment, by adopting the pole 5 disclosed in some embodiments of the present application, the bending angle of the pole ear 33 when in contact with the slot side wall 531 can be reduced to avoid a relatively obvious stress concentration at the bending part of the pole ear 33, thereby effectively avoiding cracks or even fractures at the bending part of the pole ear 33. In this way, the structural integrity of the pole ear 33 can be ensured, so as to improve the current carrying capacity of the pole ear 33, enhance the current passing capacity between the pole ear 33 and the pole 5, and thereby enhance the performance of the single cell 3.

[0091] See also Fig.12 , Fig.12 Schematic diagram of the cooperation between the pole 5 and the pole lug 33 in another cross-sectional direction provided by an embodiment of the present application. In one embodiment, along the direction perpendicular to the axis of the pole 5, the length dimension of the pole lug welding groove 53 is L1. The length dimension of the pole lug 33 is L2. Satisfies: L1>L2. In this way, the smoothness of the pole lug 33 being installed in the pole lug welding groove 53 can be improved, so as to improve the efficiency of the connection between the pole lug 33 and the pole 5.

[0092] Among them, when the pole ear 33 is a rectangular pole ear 33, the length dimension L2 of the pole ear 33 is the length dimension L2 at any height position of the pole ear 33; when the pole ear 33 is a trapezoidal pole ear 33, that is, the long bottom of the pole ear 33 is connected to the pole piece, the length dimension L2 of the pole ear 33 is half of the sum of the length of one end of the pole ear 33 connected to the pole piece and the length of one end of the pole ear 33 away from the pole piece.

[0093] The technical scheme and technical effects of the present application are described in detail below through specific embodiments. The following embodiments are only some embodiments of the present application and do not specifically limit the present application.

[0094] This embodiment aims to examine the influence of applying the pole 5 to the single battery 3 on the battery performance.

[0095] The test contents of the embodiment are described as follows:

[0096] 1. Test related instructions

[0097] The test objects are three types of single cells 3 with an energy density of 280 Ah. The differences between these three types of single cells 3 are as follows: the angle α of the first type of single cell 3 is 0, that is, the groove side wall 531 is parallel to the axis of the pole 5, the angle α of the second type of single cell 3 is 30°, and the angle α of the third type of single cell 3 is 60°.

[0098] The degree of fit refers to the percentage of the area where the electrode tab 33 fits the electrode column 5 to the area where the electrode tab 33 faces the slot side wall 531 .

[0099] The current capacity represents the current capacity between the pole 5 and the pole lug 33 .

[0100] The location where the temperature is tested is the temperature at the negative electrode tab 33 .

[0101] The ambient temperature during the test was 25±1℃.

[0102] 2. Test Results

[0103] The above three types of single cells 3 are tested, and the test data obtained are as follows:

[0104] α Degree of fit Current capacity Temperature rise 0 70.43％ 80A 15.4℃ 30° 85.57％ 91A 10.2℃ 60° 95.69％ 95A 5.5℃

[0105] Table 1. Test data table

[0106] According to Table 1, we can see that:

[0107] (1) The degree of fit: As the angle α increases from 0° to 30° and 60°, the degree of fit increases from 70.43% to 85.58% and 95.69%. It can be seen that the larger the angle α, the better the fit between the tab 33 and the pole 5, and the larger the fit area between the tab 33 and the pole 5; correspondingly, the better the current carrying capacity.

[0108] (2) Current capacity: As the angle α increases from 0° to 30° and 60°, the current capacity increases from 80 A to 91 A and 95 A. It can be seen that the larger the angle α, the better the current capacity between the pole lug 33 and the pole 5.

[0109] (3) Temperature rise: As the angle α increases from 0° to 30° and 60°, the temperature rise decreases from 15.4°C to 10.2°C and 5.5°C. It can be seen that the larger the angle α, the smaller the temperature rise.

[0110] Therefore, by limiting the size of the angle α between the slot sidewall 531 and the axis of the pole 5, the pole lug 33 cluster not only has a small bending angle to effectively avoid the pole lug 33 from breaking, but also can better contact with the slot sidewall 531, so that the pole lug 33 and the pole 5 fit more closely, and the contact area between them is increased. In this way, the resistance when the current passes can be reduced, the flow between the pole 5 and the pole lug 33 is improved, and the current can be transmitted more smoothly. At the same time, due to the reduction in resistance, the heat generated at the flow point between the pole lug 33 and the pole 5 will also be reduced accordingly, which helps to reduce the temperature rise. In this way, the performance of the single battery 3 can be improved.

[0111] The embodiments of the present application are introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and core idea of ​​the present application. At the same time, for technical personnel in this field, according to the idea of ​​the present application, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A pole, characterized in that: include: The body has a first surface, wherein the first surface is provided with a tab welding groove; The electrode tab welding groove has a groove side wall, and the groove side wall is configured to contact the electrode tab. Along the direction away from the first surface, the plane where the groove side wall is located gradually tilts toward the axis of the pole.

2. The pole according to claim 1, characterized in that: Along a direction perpendicular to the axis of the pole, the pole tab welding groove passes through one end or both ends of the body.

3. The pole according to claim 2, characterized in that: In any two cross sections perpendicular to the extension direction of the electrode tab welding groove, the cross sections of the electrode tab welding groove have the same shape and size.

4. The pole according to any one of claims 1 to 3, characterized in that: There are two slot side walls, and the two slot side walls are centrally symmetrically distributed along the axis of the pole.

5. The pole according to claim 4, characterized in that: The two groove side walls are connected to each other at one side away from the groove opening of the tab welding groove.

6. The pole according to claim 5, characterized in that: A first chamfer is provided at the connection between the groove side wall and the first surface. The first chamfer is a rounded chamfer with a radius ranging from 15 to 30 mm.

7. The pole according to claim 4, characterized in that: The tab welding groove also has a groove bottom wall, and the sides of the two groove side walls away from the groove opening of the tab welding groove are both connected to the groove bottom wall.

8. The pole according to claim 7, characterized in that: A second chamfer is provided at the connection between the groove side wall and the groove bottom wall. The second chamfer is a rounded chamfer with a radius ranging from 5 to 15 mm.

9. The pole according to claim 7, characterized in that: A third chamfer is provided at the connection between the groove side wall and the first surface. The third chamfer is a rounded chamfer with a radius ranging from 10 to 20 mm.

10. The pole according to any one of claims 1 to 3, characterized in that: The angle between the plane where the slot side wall is located and the axis of the pole is an angle α, which satisfies: 30°≤α≤65°.

11. The pole according to any one of claims 1 to 3, characterized in that: An extension portion is disposed on the outer peripheral surface of the body, the extension portion is disposed close to the first surface, and the extension portion is located on one side of the groove side wall.

12. The pole according to claim 11, characterized in that: There are two slot side walls, which are centrally symmetrically distributed along the axis of the pole. There are two extension parts, which correspond to the two slot side walls one by one.

13. A cover plate assembly, characterized in that: include: Cover plate; And, the pole according to any one of claims 1 to 12, wherein the pole is penetrated through the cover plate.

14. A single cell battery, characterized in that: include: A housing having a receiving cavity; An electrode assembly is disposed in the accommodating cavity; A pole ear, one end of which is connected to the electrode assembly; And, the cover plate assembly according to claim 13, which covers the housing to close the accommodating cavity; The other end of the pole lug extends into the pole lug welding groove, and the pole lug is in contact with the side wall of the groove.

15. The single cell according to claim 14, characterized in that: Along the direction perpendicular to the axis of the pole, the length dimension of the pole tab welding groove is L1, and the length dimension of the pole tab is L2, which satisfies: L1>L2.

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