Pole, cover plate assembly and single battery

Abstract

The utility model 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] This application relates to the field of battery technology, specifically to an electrode post, cover plate assembly, and single cell battery. Background Technology

[0002] A single battery cell includes a casing, an electrode assembly disposed within the casing, and terminals disposed on the casing. In related technologies, to improve the energy density of a single battery cell, the electrode assembly is directly connected to the terminals via tabs. The connection method between the terminals and tabs has a significant impact on the performance of the single battery cell.

[0003] In related technologies, the scheme of connecting the tabs and terminals has some shortcomings, resulting in poor performance of individual cells. Utility Model Content

[0004] Embodiments of this application provide an electrode post, a cover plate assembly, and a single cell, which can improve the performance of a single cell.

[0005] In a first aspect, embodiments of this application provide an electrode post, which includes a body having a first surface and a tab welding groove provided on the first surface; the tab welding groove has a groove sidewall configured to contact the tab of a single cell, and the plane containing the groove sidewall gradually tilts toward the axis of the electrode post along a direction away from the first surface.

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

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

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

[0009] In one embodiment, the two groove sidewalls are connected to each other on the side away from the groove opening of the electrode welding groove.

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

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

[0012] In one embodiment, a second chamfer is provided at the connection between the side wall and the bottom wall of the tank. 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 sidewall and the first surface. 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 containing the sidewall of the groove and the axis of the pole is angle α, which satisfies: 30°≤α≤65°.

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

[0016] In one embodiment, there are two sidewalls of the slot, which are symmetrically distributed along the axis of the pole post, and there are two extensions, which correspond one-to-one with the two sidewalls of the slot.

[0017] Secondly, embodiments of this application provide a cover plate assembly, which includes a cover plate and the aforementioned pole post; the pole post passes through the cover plate.

[0018] Thirdly, embodiments of this application provide a single-cell battery, which includes a housing, an electrode assembly, tabs, and the aforementioned cover assembly; the cover assembly covers the housing to seal the receiving cavity; the housing has the receiving cavity; the electrode assembly is disposed in the receiving cavity; one end of the tab is connected to the electrode assembly, and the other end of the tab extends into the tab welding groove, and the tab is attached to the side wall of the groove.

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

[0020] The beneficial effects of the embodiments of this application are as follows:

[0021] In the embodiments of this application, by limiting the inclination of the groove sidewall in contact with the tab towards the axis of the electrode post, the bending angle when the tab contacts the groove sidewall can be reduced, thereby avoiding significant stress concentration at the bending point and effectively preventing cracks or even breakage of the tab at the bending point. This ensures the structural integrity of the tab, improves its current-carrying capacity, enhances the current flow capacity between the tab and the electrode post, and ultimately improves the performance of the single-cell battery. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

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

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

[0025] Figure 3 This is a schematic diagram of the mating of the pole post and the pole tab provided in an embodiment of this application;

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

[0027] Figure 5 This is a schematic diagram of another pole provided in an embodiment of this application;

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

[0029] Figure 7 This is a schematic diagram of another pole provided in an embodiment of this application;

[0030] Figure 8 This is provided by the embodiments of this application. Figure 7 The side view of the pole shown;

[0031] Figure 9 This application provides Figure 7 A schematic diagram showing the connection between the pole post and the pole tab;

[0032] Figure 10 This is a schematic diagram of the structure of the cover plate assembly provided in an embodiment of this application;

[0033] Figure 11 This is a schematic diagram of the structure of a single battery provided in an embodiment of this application;

[0034] Figure 12 This is a schematic diagram of the electrode post and electrode tab mating in another cross-sectional direction provided by an embodiment of this application.

[0035] Explanation of reference numerals in the attached figures:

[0036] 5-Pole post; 51-Body; 52-First surface; 53-Pole lug welding groove; 531-Groove sidewall; 532-Groove bottom wall; 54-Extension; 55-Pole post axis;

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

[0038] 3-Single cell; 31-Housing; 32-Electrode assembly; 321-End face of electrode assembly facing the terminal post; 33-Taper. Detailed Implementation

[0039] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0040] Furthermore, it should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of this application. In this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0041] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

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

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

[0044] To facilitate understanding of the solution in this application, the relevant technologies of this application will be explained before introducing the electrode post, cover plate assembly and single cell provided in this application.

[0045] In related technologies, a single-cell battery includes a casing, an electrode assembly disposed within the casing, and terminals disposed on the casing. To improve the energy density of the single-cell battery, the electrode assembly is directly connected to the terminals via tabs. While this connection method can increase the energy density of the single-cell battery, it requires the tabs to be bent at least once at a relatively large angle. Since the tabs are made of foil, they are prone to breakage during bending. This negatively impacts the overcurrent between the tabs and terminals, thus affecting the performance of the single-cell battery.

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

[0047] Please see Figure 1 and Figure 2 , Figure 1 This is a schematic diagram of the structure of the pole post 5 provided in an embodiment of this application. Figure 2 This is a schematic cross-section of the electrode post 5 provided in an embodiment of this application, perpendicular to the extension direction of the tab welding groove 53. The embodiment of this application provides an electrode post 5 applied to a single-cell battery. The electrode post 5 includes a body 51. The body 51 has a first surface 52. The first surface 52 is provided with a tab welding groove 53. The tab welding groove 53 has a groove sidewall 531. The groove sidewall 531 is configured to contact the tab 33 of the single-cell battery 3. Along a direction away from the first surface 52, the plane containing the groove sidewall 531 gradually slopes towards the axis of the electrode post 5.

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

[0049] It is understandable that the first surface 52 faces the electrode assembly of the single cell.

[0050] It is understood that the plane containing the tank sidewall 531 forms an acute angle α with the axis of the electrode post 5, and is located on the side of the first surface 52 away from the electrode assembly. It is also understood that the plane containing the tank sidewall 531 forms an acute angle α with the axis of the electrode post 5. Correspondingly, the tank sidewall 531 forms an acute angle β with the end face of the electrode assembly of the single cell facing the electrode post 5, and angle β and angle α are complementary.

[0051] It is understandable that 0 < α < 90°. Specifically, the included 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 is understandable that the electrode 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 electrode welding groove 53 can be a V-shaped groove, a trapezoidal groove, or other shapes. The shape of the bottom wall of the electrode welding groove 53 is not limited; it can be a flat bottom wall, a circular arc groove bottom, or a groove bottom with other irregular shapes.

[0054] like Figure 3 As shown, Figure 3 This is a schematic diagram of the engagement of the pole post 5 and the tab 33 provided in an embodiment of this application. When the pole post 5 and the tab 33 are connected, multiple layers of tabs 33 are stacked to form a tab cluster. The tab cluster extends along the sidewall 531 of the groove and is inserted into the tab welding groove 53. Figure 4 As shown, Figure 4 yes Figure 3 In the enlarged view at point A, the tabs 33 near the groove sidewall 531 in the tab cluster have bends, and the bends are relatively small; and as the distance from the groove sidewall 531 increases, the bend angle of the tabs 33 in the tab cluster becomes smaller, that is, the flatness of the tabs 33 is better.

[0055] In this embodiment, by limiting the inclination of the groove sidewall 531 that contacts the tab 33 towards the axis of the terminal post 5, the bending angle of the tab 33 when it contacts the groove sidewall 531 can be reduced. This avoids significant stress concentration at the bending point of the tab 33, effectively preventing cracks or even breakage at the bending point. This ensures the structural integrity of the tab 33, improves its current-carrying capacity, enhances the current flow capacity between the tab 33 and the terminal post 5, and ultimately improves the performance of the single-cell battery 3.

[0056] Furthermore, by limiting the angle between the groove sidewall 531 that contacts the tab and the axis of the terminal post 5 to an acute angle, better fit between the tab 33 and the groove sidewall 531 can be achieved, thereby reducing the resistance at the contact point between the tab 33 and the terminal post 5. This not only improves the current-carrying capacity between the tab 33 and the terminal post 5 but also controls the temperature rise, thus improving the performance of the single cell 3.

[0057] Please see Figure 5 or Figure 6 , Figure 5 This is a schematic diagram of another pole post 5 provided in an embodiment of this application. Figure 6 This is a schematic diagram of the structure of another pole post 5 provided in an embodiment of this application. In one embodiment, along the direction perpendicular to the axis of the pole post 5, the electrode tab welding groove 53 passes through one or both ends of the body 51.

[0058] In some embodiments, one end of the electrode welding groove 53 may penetrate one end of the body 51, such as... Figure 5 As shown; in some other embodiments, the two ends of the electrode welding groove 53 may extend through both ends of the body 51, such as... Figure 6 As shown.

[0059] It is understood that when both ends of the electrode welding groove 53 penetrate the body 51 in a direction perpendicular to the axis of the electrode post 5, the length dimension L1 of the electrode welding groove 53 in the extension direction of the electrode welding groove 53 is equal to the length dimension L3 of the body 51 in the extension direction of the electrode welding groove 53.

[0060] In this embodiment, by extending the tab welding groove 53 through one or both ends of the body 51, the size of the tab welding groove 53 can be increased, allowing for a larger width of the tab 33 fitted within it, thereby improving the current flow capacity between the tab 33 and the electrode post 5. Furthermore, the port connecting the tab welding groove 53 to the outside world enhances the ease of processing the tab welding groove 53 and the ease of welding it to the tab 33. This improves the efficiency of processing the electrode post 5 and the efficiency of welding the electrode post 5 to the tab 33.

[0061] Please see Figure 1 or Figure 5 or Figure 6 In one embodiment, the shape and dimensions of the electrode welding groove 53 are the same in any two cross-sections perpendicular to the extension direction of the electrode welding groove 53. This makes the shape of the electrode welding groove 53 regular, which helps to reduce the processing difficulty and improve the forming efficiency of the electrode post 5.

[0062] Please see Figure 2 In one embodiment, there are two groove sidewalls 531. The two groove sidewalls 531 are centrally symmetrically distributed along the axis of the pole post 5. This not only makes the structure of the pole post 5 symmetrical and improves the stress state of the pole post 5, but also reduces the difficulty of connecting the tab 33 to the pole post 5, so that when welding the tab 33 to the pole post 5, the tab cluster can be welded to the groove sidewall 531 adjacent to it.

[0063] Furthermore, in some embodiments, the pole post 5 is welded to two tab clusters, which are symmetrically distributed along the axis of the pole post 5. The two tab clusters can be welded to two groove sidewalls 531 respectively. In this way, there are multiple welding surfaces between the tabs 33 and the pole post 5, thereby enhancing the stability of the connection between the pole post 5 and the tab clusters.

[0064] Please see Figure 2In one embodiment, the two sidewalls 531 of the grooves away from the opening of the tab welding groove 53 are connected to each other. In this way, the tab welding groove 53 is a V-shaped groove, which has a simple structure, is easy to process, and also allows the pole post 5 to have a thicker dimension in the part where the tab welding groove 53 is provided, so as to improve the structural strength of the pole post 5.

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

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

[0067] In this embodiment, by setting a first chamfer R1, on the one hand, the friction of the inflection point at the connection between the groove sidewall 531 and the first surface 52 on the tab 33 can be reduced, thereby improving the stress state of the tab 33 and preventing the tab 33 from being scratched; on the other hand, the stress on the pole 5 at the connection can be improved, thereby enhancing the reliability of the pole 5.

[0068] Please see Figure 7 and Figure 8 , Figure 7 This is a schematic diagram of the structure of another pole post 5 provided in an embodiment of this application. Figure 8 This is provided by the embodiments of this application. Figure 7 The diagram shows a side view of the electrode post 5. In one embodiment, the electrode welding groove 53 further includes a bottom wall 532. The sides of both side walls 531 away from the opening of the electrode welding groove 53 are connected to the bottom wall 532; specifically, the two side walls 531 are connected to the two side edges of the bottom wall 532, respectively. This makes the electrode welding groove 53 a trapezoidal groove with an opening width greater than the bottom width. Optionally, the electrode welding groove 53 is an isosceles trapezoidal groove.

[0069] In this embodiment, through the above-mentioned arrangement, on the one hand, two groove sidewalls 531 can be formed on the pole post 5 to facilitate the connection between the pole post 5 and the tab 33; on the other hand, the depth dimension of the tab welding groove 53 can be controlled to ensure the overall strength of the pole post 5.

[0070] Please see Figure 8 In one embodiment, a second chamfer R2 is provided at the connection between the sidewall 531 and the bottomwall 532 of the groove. The second chamfer R2 is a rounded chamfer with a radius ranging from 5 to 15 mm.

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

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

[0073] In this embodiment, by setting a second chamfer R2, on the one hand, when the electrode 33 extends from the side wall 531 of the groove to the bottom wall 532 of the groove, the electrode 33 can be smoothly bent between the side wall 531 and the bottom wall 532 of the groove, thereby improving the stress state of the electrode 33 and preventing the electrode 33 from being damaged due to excessively sharp bending; on the other hand, it can improve the stress on the pole 5 at the connection point and improve the reliability of the pole 5.

[0074] In addition, chamfers are mainly applied to the corners of the pole post 5 where it contacts the tab 33. This not only makes the tab 33 bend smoothly, thus reducing stress concentration at the bend, but also controls the processing cost of the chamfer, thereby controlling the manufacturing cost of the pole post 5.

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

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

[0077] In this embodiment, by setting a third chamfer R3, on the one hand, the friction of the inflection point at the connection between the groove sidewall 531 and the first surface 52 on the tab 33 can be improved, thereby improving the stress state of the tab 33 and preventing the tab 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 containing the sidewall 531 of the groove and the axis of the pole post 5 is α, which satisfies: 30°≤α≤65°.

[0079] For example, the included 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 included angle α, on the one hand, it can avoid the angle being too small, which would cause the tab 33 to bend at a large angle in order to fit the sidewall 531 of the groove, thereby improving the stress state at the bend of the tab 33 and effectively preventing the tab 33 from having cracks or even breaking at the bend; on the other hand, it can avoid the angle being too large, which would cause the overlap height between the tab 33 and the pole post 5 to be small, thereby ensuring the overlap height between the tab 33 and the pole post 5 and reducing the height dimension occupied by the tab 33.

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

[0082] It is understandable that the extension 54 is integrally formed with the main body 51.

[0083] In this embodiment, by providing the extension portion 54, on the one hand, the tab 33 can be stopped and engaged with the end cap of the single cell through the extension portion 54 to prevent the electrode post 5 from coming off the end cap; on the other hand, the groove opening of the tab welding groove 53 can be extended toward the extension portion 54. In this way, while increasing the size of the groove opening, the strength of the electrode post 5 at the groove opening can be guaranteed, and deformation of the electrode post 5 at the groove opening can be avoided.

[0084] Furthermore, by providing the extension 54, the extension 54 can support the electrode 33 when welding the electrode tab 33 to the electrode post 5, preventing the electrode tab 33 from deforming during welding, thereby improving the reliability of the welding between the electrode tab 33 and the electrode post 5.

[0085] Please see Figure 7 In one embodiment, there are two groove sidewalls 531. The two groove sidewalls 531 are centrally symmetrically distributed along the axis of the pole post 5. There are two extensions 54. The two extensions 54 correspond one-to-one with the two groove sidewalls 531. In this way, the pole post 5 has a symmetrical structure, which can improve the stress state of the pole post 5.

[0086] Please see Figure 10 , Figure 10 This is a schematic diagram of the structure of the cover plate 21 assembly 2 provided in an embodiment of this application. Accordingly, an embodiment of this application also provides a cover plate 21 assembly 2, which includes a cover plate 21 and the pole post 5 disclosed in some embodiments of this application. The pole post 5 passes through the cover plate 21.

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

[0088] In this embodiment, by employing the electrode post 5 disclosed in some embodiments of this application, the bending angle of the tab 33 when it contacts the sidewall 531 of the groove can be reduced, thereby avoiding significant stress concentration at the bending point of the tab 33 and effectively preventing cracks or even breakage at the bending point. This ensures the structural integrity of the tab 33, improves its current-carrying capacity, enhances the current flow capacity between the tab 33 and the electrode post 5, and ultimately improves the performance of the single-cell battery 3.

[0089] Please see Figure 11 , Figure 11 This is a schematic diagram of the structure of a single-cell battery 3 provided in an embodiment of this application. Accordingly, an embodiment of this application also provides a single-cell battery 3. The single-cell battery 3 includes a housing 31, an electrode assembly 32, tabs 33, and a cover plate 21 assembly 2 disclosed in some embodiments of this application. The cover plate 21 assembly 2 covers the housing 31 to close the receiving cavity. The housing 31 has a receiving cavity. The electrode assembly 32 is disposed within the receiving cavity. One end of the tab 33 is connected to the electrode assembly 32, and the other end of the tab 33 extends into the tab welding groove 53. The tab 33 is abutted against the side wall 531 of the groove.

[0090] In this embodiment, by employing the electrode post 5 disclosed in some embodiments of this application, the bending angle of the tab 33 when it contacts the sidewall 531 of the groove can be reduced, thereby avoiding significant stress concentration at the bending point of the tab 33 and effectively preventing cracks or even breakage at the bending point. This ensures the structural integrity of the tab 33, improves its current-carrying capacity, enhances the current flow capacity between the tab 33 and the electrode post 5, and ultimately improves the performance of the single-cell battery 3.

[0091] Please see Figure 12 , Figure 12 This is a schematic diagram of the mating of the pole post 5 and the tab 33 in another cross-sectional direction provided by an embodiment of this application. In one embodiment, the length of the tab welding groove 53 along the direction perpendicular to the axis of the pole post 5 is L1. The length of the tab 33 is L2. L1 > L2. This improves the smoothness of the tab 33 being installed into the tab welding groove 53, thereby improving the efficiency of the connection between the tab 33 and the pole post 5.

[0092] When the tab 33 is a rectangular tab 33, the length dimension L2 of the tab 33 is L2 at any height position of the tab 33; when the tab 33 is a trapezoidal tab 33, that is, when the long base of the tab 33 is connected to the electrode plate, the length dimension L2 of the tab 33 is half the sum of the length of the end of the tab 33 connected to the electrode plate and the length of the end of the tab 33 away from the electrode plate.

[0093] The technical solutions and effects of this application will be described in detail below through specific embodiments. The following embodiments are only some embodiments of this application and are not intended to limit this application.

[0094] This embodiment aims to examine the impact of applying the electrode post 5 to the single cell 3 on the battery performance.

[0095] The specific details of the test content for the embodiment are as follows:

[0096] I. Test-related instructions

[0097] The test subjects were three types of single-cell batteries 3, all with an energy density of 280Ah. The differences between these three types of single-cell batteries 3 were as follows: the included angle α of the first type of single-cell battery 3 was 0, that is, the sidewall 531 of the slot was parallel to the axis of the pole post 5; the included angle α of the second type of single-cell battery 3 was 30°; and the included angle α of the third type of single-cell battery 3 was 60°.

[0098] The degree of fit refers to the percentage of the area of ​​the tab 33 that fits with the pole post 5 to the area of ​​the tab 33 facing the side wall 531 of the groove.

[0099] The current-carrying capacity characterizes the current-carrying capacity between pole 5 and tab 33.

[0100] The temperature was measured at the negative electrode tab 33.

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

[0102] II. Test Results

[0103] The above three types of single-cell batteries were tested, and the test data are as follows:

[0104] α Fit Overcurrent 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:

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

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

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

[0110] Therefore, by limiting the angle α between the axis of the groove sidewall 531 and the terminal post 5, the tabs 33 cluster not only have a small bending angle to effectively prevent breakage, but also better contact with the groove sidewall 531, resulting in a tighter fit between the tabs 33 and the terminal post 5 and an increased contact area. This reduces resistance when current flows, improves current flow between the terminal post 5 and the tabs 33, and allows for smoother current transmission. Simultaneously, the reduced resistance also decreases the heat generated at the current flow point between the tabs 33 and the terminal post 5, helping to lower the temperature rise. Thus, the performance of the single-cell battery 3 can be improved.

[0111] The embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. An electrode post, characterized in that, include: The body has a first surface, and the first surface is provided with a tab welding groove; The electrode welding groove has a groove sidewall configured to contact the electrode, and the plane containing the groove sidewall gradually slopes toward the axis of the electrode post in a direction away from the first surface.

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

3. The pole post according to claim 2, characterized in that, In any two cross sections perpendicular to the extension direction of the electrode welding groove, the shape and dimensions of the cross section of the electrode welding groove are the same.

4. The pole post according to any one of claims 1-3, characterized in that, The groove has two sidewalls, and the two sidewalls are centrally symmetrically distributed along the axis of the pole post.

5. The electrode post according to claim 4, characterized in that, The two groove sidewalls are connected to each other on the side away from the groove opening of the electrode welding groove.

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

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

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

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

10. The pole post according to any one of claims 1-3, characterized in that, The angle between the plane containing the sidewall of the groove and the axis of the pole is α, which satisfies: 30°≤α≤65°.

11. The pole post according to any one of claims 1-3, characterized in that, An extension is provided on the outer peripheral surface of the body, the extension is located close to the first surface, and the extension is located on one side of the groove sidewall.

12. The pole post according to claim 11, characterized in that, There are two sidewalls of the groove, which are centrally symmetrically distributed along the axis of the pole post. There are two extensions, which correspond one-to-one with the two sidewalls of the groove.

13. A cover plate assembly, characterized in that, include: Cover plate; And, as described in any one of claims 1-12, the pole is disposed on the cover plate.

14. A single-cell battery, characterized in that, include: The shell has a receiving cavity; The electrode assembly is disposed within the receiving cavity; A tab, one end of which is connected to the electrode assembly; And, as claimed in claim 13, the cover assembly, when closed with the housing, to seal the receiving cavity; The other end of the electrode extends into the electrode welding groove, and the electrode is in contact with the side wall of the groove.

15. The single-cell battery according to claim 14, characterized in that, Along the direction perpendicular to the axis of the pole post, the length of the electrode welding groove is L1, and the length of the electrode lug is L2, satisfying: L1 > L2.

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