Pole, battery cell, battery and power utilization device

Abstract

The utility model relates to a pole, a battery cell, a battery and a power utilization device, the pole comprises a first surface, a second surface and a welding groove, the first surface and the second surface are oppositely arranged in the thickness direction of the pole, and the second surface is used for being arranged towards the interior of the battery cell and is provided with a welding area used for being welded with a battery cell collector plate. The welding groove is formed in the first surface in a sunken mode and corresponds to the welding area in the thickness direction. The welding groove comprises a first groove section, the first groove section comprises a first end and a second end which are sequentially arranged in the thickness direction, and the first end is closer to the second surface than the second end. Wherein the first end completely exposes the second end, and the opening area of the first end is larger than that of the second end. According to the technical scheme provided by the invention, the welding reliability of the pole and the collector plate in the battery cell can be improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to poles, battery cells, batteries and electrical devices. Background Art

[0002] The wound cell is a common cell structure. The internal core is wound, and the pole lugs of the core are usually welded to the poles on the cell end caps through the collector plate. In related technologies, the collector plate and the pole are connected by a welding needle passing through the center hole of the core to complete the welding of the collector plate and the pole by torque welding. This method is limited by the diameter of the center hole of the core and has the problem of small weld area. Long-term use or vibration may cause weld fall-off or tearing of the collector plate, greatly reducing the reliability of the cell. Utility Model Content

[0003] Based on this, it is necessary to provide a pole, a cell, a battery and an electrical device to address the problem that the welding between the cell collector and the pole is not reliable, thereby reducing the reliability of the cell.

[0004] In a first aspect, an embodiment of the present application provides a pole for a battery cell, the pole comprising:

[0005] A first surface and a second surface disposed opposite to each other in a thickness direction of the pole, wherein the second surface is disposed toward the inside of the battery cell and has a welding area for welding to a current collecting plate in the battery cell; and

[0006] A welding groove is recessed on the first surface and is arranged corresponding to the welding area in the thickness direction; the welding groove includes a first groove section, the first groove section includes a first end and a second end arranged in sequence in the thickness direction, and the first end is arranged closer to the first surface than the second end;

[0007] The first end completely exposes the second end, and an opening area of ​​the first end is larger than an opening area of ​​the second end.

[0008] In some embodiments, any cross-sectional shape of the welding groove is circular.

[0009] In some embodiments, the caliber of the first end is R, and the caliber of the second end is r, satisfying: R=a*r, and 1.36≥a>1.

[0010] In some embodiments, the diameter of the first slot section decreases from the first end to the second end.

[0011] In some embodiments, the diameter of the first slot section increases first and then decreases from the first end to the second end;

[0012] The a satisfies: 1.29≥a>1.

[0013] In some embodiments, the welding slot further includes a second slot segment, the second slot segment is located at one end of the first slot segment and is connected to the second end of the first slot segment;

[0014] The second groove section has a third end located at the bottom of the welding groove, and the diameter r' of the third end and the diameter r of the second end satisfy: r≤r'≤1.2r;

[0015] The a satisfies: 1.5≥a>1.

[0016] In some embodiments, the pole includes a first convex portion and a second convex portion, wherein the first convex portion is convexly disposed at a first end where the first surface is located along a direction intersecting the thickness direction; and the second convex portion is convexly disposed at a second end where the second surface is located;

[0017] The second convex portion can be bent to switch between a first state and a second state. The second convex portion in the first state is protruded along the thickness direction. The second convex portion in the second state is protruded along a direction perpendicular to the thickness direction and a clamping groove is formed between the second convex portion and the first convex portion.

[0018] A thinning groove is formed inwardly on the second surface, and the second convex portion forms a part of the groove wall of the thinning groove.

[0019] In a second aspect, an embodiment of the present application provides a battery cell, including:

[0020] a housing having a mounting hole;

[0021] An electrode assembly, loaded in the housing;

[0022] a current collecting plate, located in the housing and electrically connected to an end of the electrode assembly facing the mounting hole; and

[0023] As in any of the above embodiments, the pole is installed in the installation hole, and the welding area of ​​the pole is welded to the collecting plate.

[0024] In a third aspect, an embodiment of the present application provides a battery, comprising the above-mentioned battery cell.

[0025] In a fourth aspect, an embodiment of the present application provides an electrical device, comprising the above-mentioned battery, wherein the battery is used to provide electrical energy.

[0026] For the pole, battery cell, battery and electrical device, the welding beam can be injected into the welding groove from the first end of the first groove section of the pole welding groove, and then penetrate the welding welding area and the collector plate. Since the welding groove thins the pole, the welding beam only needs to penetrate the thinner pole to perform welding, and the energy utilization rate of the welding beam is high, which helps to improve the welding effect.

[0027] Moreover, in actual operation, for the convenience of operation, the welding beam is mostly incident at an angle. At this time, when the welding beam is incident from the first end of the first slot section in a flared shape to the second end thereof, the first end can effectively avoid the welding beam, making it easier for the welding beam to reach the bottom edge of the welding slot, thereby allowing the welding beam to heat-melt a larger welding area, increasing the welding area between the welding area and the collector plate, making the welding between the pole and the collector plate more reliable, and helping to improve the reliability of the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Moreover, the same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0029] Figure 1 Schematic diagrams of the appearance of battery cells in some embodiments.

[0030] Figure 2 FIG. 4 is an internal cross-sectional view of a battery cell according to some embodiments.

[0031] Figure 3 Schematic diagrams of the appearance of poles in some embodiments.

[0032] Figure 4 2 is a cross-sectional view of a pole according to some embodiments.

[0033] Figure 5 sectional views of poles according to other embodiments.

[0034] Figure 6 2 is a broken view of a pole of some further embodiments.

[0035] Figure 7 for Figure 4 A schematic structural diagram of the second protrusion of the pole in the first state of the illustrated embodiment.

[0036] The reference numerals in the specific implementation manner are as follows:

[0037] 100. Battery cell;

[0038] 10, pole; z, thickness direction; m1, first surface; m2, second surface; Q, welding area; 11, welding groove; 11a, first groove section; d1, first end; d2, second end; 11b, second groove section; d3, third end; 12, first convex portion; 13, second convex portion; 14, clamping groove; 15, thinning groove;

[0039] 20. Shell; k. Mounting hole;

[0040] 30. Electrode assembly;

[0041] 40. Collecting plate. DETAILED DESCRIPTION

[0042] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0043] In the description of the present application, it should be understood that terms such as “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships, if any, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0044] In addition, if present, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, "plurality" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0045] In this application, unless otherwise clearly specified and limited, if any, the terms "installed", "connected", "connected", "fixed" and the like 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, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0046] In the present application, if it appears, unless otherwise clearly specified and limited, a first feature “above” or “below” a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature “above”, “above” and “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature “below”, “below” and “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0047] It should be noted that, if present, when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0048] In order to improve the welding reliability between the current collecting plate of the battery cell and the pole, the embodiment of the present application provides a pole, a battery cell, a battery and an electrical device.

[0049] The battery cell 100 in the embodiment of the present application is the smallest unit for providing electric energy. Figure 1 and Figure 2 In some embodiments, the battery cell 100 includes a housing 20, a pole 10, a current collecting plate 40, and an electrode assembly 30. The housing 20 has a mounting hole k. The electrode assembly 30 is loaded in the housing 20. The current collecting plate 40 is located in the housing 20 and is electrically connected to one end of the electrode assembly 30 facing the mounting hole k. The pole 10 is mounted in the mounting hole k and is welded to the current collecting plate 40.

[0050] The housing 20 is usually made of metal, such as aluminum, stainless steel, etc. The pole 10 and the collector plate 40 are made of conductive materials, such as aluminum, copper, stainless steel, etc. In some examples, the housing 20 includes a housing and an end cover, the electrode assembly 30 and the collector plate 40 are located in the housing, the end cover covers the housing, and the mounting hole k is located on the end cover. In some examples, the end of the electrode assembly 30 away from the mounting hole k is electrically connected to the housing, at which time, the pole 10 is the first electrode of the housing, and the housing serves as the second electrode of the battery cell 100. The electrode assembly 30 can be wound or laminated, and usually includes a positive electrode sheet, a negative electrode sheet, and a separator separated between the positive electrode sheet and the negative electrode sheet. The pole ear is an electrical connection structure for the electrode assembly 30 to be connected to the external circuit, and the collector plate 40 is electrically connected to the pole ear of the electrode assembly 30. The pole ear includes a positive pole ear and a negative pole ear, and the positive pole ear and the negative pole ear can be arranged on the same side of the electrode assembly 30, or on opposite sides. The battery cell 100 can be cylindrical, rectangular, and other shapes.

[0051] In addition to the battery cell 100, the battery in the embodiment of the present application also includes a box in some examples. The box is used to accommodate the battery cell 100, and a plurality of battery cells 100 are usually arranged in the box. A thermal management system for cooling the battery cell 100 and a battery management system for monitoring the working state of the battery cell 100 can be arranged in the box. The specific structure of the battery can refer to the conventional settings.

[0052] The battery in the embodiment of the present application can be used to power an electrical device. The electrical device can be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery car, an electric car, a ship, etc. Taking the electrical device as a vehicle as an example, the battery can be set at the rear, head or bottom of the vehicle, and the battery can provide power for the drive of the vehicle, and can also provide power for the control system of the vehicle.

[0053] The pole 10 in the embodiment of the present application is described in detail below.

[0054] Reference Figures 3 to 6 The pole 10 provided in the embodiment of the present application includes a first surface m1, a second surface m2 and a welding groove 11. The first surface m1 and the second surface m2 are arranged opposite to each other in the thickness direction z of the pole 10. The second surface m2 is used to be arranged toward the inside of the battery cell 100, and has a welding area Q for welding with the current collecting plate 40 of the battery cell 100. The welding groove 11 is recessed in the first surface m1 and is arranged corresponding to the welding area Q in the thickness direction z. The welding groove 11 includes a first groove section 11a, and the first groove section 11a includes a first end d1 and a second end d2 arranged in sequence in the thickness direction z. The first end d1 is arranged closer to the second surface m2 than the second end d2. Among them, the first end d1 completely exposes the second end d2, and the opening area of ​​the first end d1 is larger than the opening area of ​​the second end d2.

[0055] When the pole 10 is applied to the battery cell 100, its first surface m1 is arranged toward the outside of the battery cell 100, and is used to electrically connect to an external conductive structure, for example, the pole 10 is welded to the tab through the first surface m1. Typically, the first surface m1 of the pole 10 is arranged to protrude from the outer shell 20 of the battery cell 100. The second surface m2 of the pole 10 faces the inside of the battery cell 100 and is located inside the battery cell 100, and can be welded to the current collecting plate 40 inside the battery cell 100. The area where the second surface m2 is welded to the current collecting plate 40 is called the welding area Q. The welding area Q can be a planar area or a non-planar area, and the structure of the welding area Q can be designed according to the structural adaptability of the current collecting plate 40.

[0056] The first surface m1 is recessed to form a welding groove 11, which is recessed substantially along the thickness direction z of the pole 10. When the pole 10 is installed at the mounting hole k of the housing 20, the thickness direction z of the pole 10 is consistent with the depth direction of the mounting hole k. The welding groove 11 is open toward the outside of the battery cell 100. When welding the pole 10 and the collector plate 40, a laser welding beam can be emitted from the open end of the welding groove 11 toward the inside of the welding groove 11, and the welding area Q arranged corresponding to the welding groove 11 is melted at a high temperature, so that the welding area Q is welded to the collector plate 40.

[0057] The welding groove 11 includes a first groove section 11a, and the first end d1 of the first groove section 11a is generally located on the first surface m1, that is, as the opening end of the welding groove 11. The second end d2 of the first groove section 11a is arranged closer to the second surface m2 than the first end d1. In some examples, the welding groove 11 includes only the first groove section 11a, and the position where the second end d2 of the first groove section 11a is located constitutes the groove bottom of the welding groove 11.

[0058] The first end d1 completely exposes the second end d2, that is, the projection of the second end d2 along the thickness direction z completely falls within the range of the first end d1, and the groove wall portion of the welding groove 11 between the first end d1 and the second end d2 does not cover the second end d2, and the minimum position of the opening area of ​​the first groove section 11a is located at the second end d2. The opening area of ​​the first end d1 is greater than the opening area of ​​the second end d2, that is, the first end d1 exceeds the projection range of the second end d2. At this time, the first groove section 11a is flared.

[0059] When the above-mentioned pole 10 is applied to the battery cell 100, the welding beam can be injected into the welding groove 11 from the first end d1 of the first groove section 11a of the welding groove 11, and then penetrate the welding welding area Q and the current collecting plate 40. Since the welding groove 11 thins the pole 10, the welding beam only needs to penetrate the thinner pole 10 to perform welding, and the energy utilization rate of the welding beam is high, which helps to improve the welding effect.

[0060] Moreover, in actual operation, for the convenience of operation, the welding beam is mostly incident at an angle. At this time, when the welding beam is incident from the first end d1 of the first slot section 11a in a flared shape to the second end d2 thereof, the first end d1 can effectively avoid the welding beam, making it easier for the welding beam to reach the bottom edge of the welding slot 11, thereby allowing the welding beam to heat-melt a larger area of ​​the welding area Q, increasing the welding area of ​​the welding area Q and the collector plate 40, making the welding of the pole 10 and the collector plate 40 more reliable, which helps to improve the reliability of the battery cell 100.

[0061] It should be noted that, in actual application, the above-mentioned welding groove 11 is set on the pole 10, so that laser welding can be used to weld the pole 10 and the collecting plate 40. The welding beam of laser welding has the characteristics of high energy density, strong penetration ability and strong current flow ability, which can improve the welding effect of the pole 10 and the collecting plate 40.

[0062] In some embodiments, any cross-sectional shape of the welding groove 11 is circular. The cross-sectional shape of the welding groove 11 refers to a cross-sectional shape that is substantially perpendicular to the thickness direction z. At this time, the stress distribution of the welding groove 11 during the forming process is relatively uniform, and the forming is easier.

[0063] In some embodiments, reference Figures 4 to 6 The diameter of the first end d1 is R, and the diameter of the second end d2 is r, satisfying: R=a*r, and 1.36≥a>1.

[0064] Specifically, a can be 1.1, 1.15, 1.2, 1.25, 1.3, 1.35, and any value between adjacent values.

[0065] It can be understood that the first end d1 and the second end d2 are both round ends, and the diameter refers to the diameter of the round end. a>1, that is, the diameter R of the first end d1 is larger than the diameter r of the second end d2, so that the first slot section 11a is in the flared shape described above. 1.36≥a, that is, the diameter R of the first end d1 will not be too large, so that the proportion of the round area corresponding to the first end d1 on the first surface m1 of the pole 10 can be reduced, ensuring that the pole 10 has sufficient electrical connection area with the external structure, and the electrical connection of the pole 10 is more reliable.

[0066] In some embodiments, reference Figure 4 The diameter of the first groove section 11a decreases from the first end d1 to the second end d2.

[0067] It can be understood that the groove wall of the first groove section 11a is a rotation surface obtained by rotating a generatrix around its central axis. The caliber of the first groove section 11a decreases from the first end d1 to the second end d2, indicating that the vertical distance from the generatrix of the first groove section 11a to the central axis decreases from the first end d1 to the second end d2. At this time, the generatrix of the first groove section 11a can be a straight line or a curve (such as an arc). When the generatrix of the first groove section 11a is a straight line, the first groove section 11a is roughly conical and expanded, and the groove wall rotates to form a truncated table surface.

[0068] When the diameter of the first groove section 11a decreases from the first end d1 to the second end d2, the change trend of the groove wall not only adapts to the incident angle of the welding beam, but also facilitates molding.

[0069] In some embodiments, reference Figure 5 The diameter of the first slot section 11a increases first and then decreases from the first end d1 to the second end d2.

[0070] That is, the vertical distance from the generatrix of the first slot segment 11a to the central axis increases first and then decreases from the first end d1 to the second end d2. Specifically, the generatrix of the first slot segment 11a may be in a broken line shape or an arc shape.

[0071] At this time, the first groove section 11a is roughly in a bowl-shaped expansion shape. The expansion end (i.e., the first end d1) can not only effectively avoid the welding light beam, but also make the welding light beam reach the bottom edge position of the welding groove 11 to increase the welding area. At the same time, the expansion area of ​​the first groove section 11a in the bowl shape and its expansion end (i.e., the first end d1) will not occupy too large an area on the first surface m1, which is beneficial to the electrical connection between the first surface m1 of the pole 10 and the external structure.

[0072] Specifically in the embodiment, when the diameter of the first slot segment 11a increases first and then decreases from the first end d1 to the second end d2, a satisfies: 1.29≥a>1. Experiments have shown that when a is within this range, there is a large welding area between the pole 10 and the collector plate 40, and the first surface m1 thereof can be well electrically connected to the external structure.

[0073] In some embodiments, reference Figure 6 The welding groove 11 further includes a second groove section 11b, which is located at one end of the first groove section 11a and communicates with the second end d2 of the first groove section 11a. The second groove section 11b has a third end d3 located at the bottom of the welding groove 11, and the diameter r' of the third end d3 and the diameter r of the second end d2 satisfy: r≤r'≤1.2r.

[0074] It can be understood that the second slot section 11b is obtained by continuing to dig a slot below the first slot section 11a. In this way, the second slot section 11b can further increase the depth of the welding slot 11, increase the thinning degree of the pole 10, and further allow the welding of the welding area Q and the collector plate 40 to be achieved with a welding beam with lower power.

[0075] The third end d3 of the second groove section 11b serves as the groove bottom end of the welding groove 11, when its diameter r' and r satisfy the above relationship. Specifically, r' can be equal to r, 1.1r or 1.2r.

[0076] When r' is equal to r, the second slot section 11b can be a straight slot section, which is easy to process. When r' is greater than r and does not exceed 1.2r, the bottom area of ​​the welding slot 11 increases, which helps to increase the welding area between the pole 10 and the collector plate 40, and the processing difficulty is not too high.

[0077] Further in the embodiment, when the second slot section 11 b is present, a satisfies: 1.5 ≥ a > 1. Specifically, a can be 1.1, 1.2, 1.3, 1.4, 1.5, and any value between adjacent values.

[0078] Since the second slot section 11b further thins the pole 10, the distance between the welding area Q of the pole 10 and the bottom of the welding slot 11 is closer. When a satisfies the above range, the diameter R of the first end d1 is relatively small, and the first end d1 occupies a smaller area of ​​the first surface m1, which can greatly increase the electrical connection area between the first surface m1 and the external structure, and the pole 10 can be better electrically connected to the external structure. Moreover, since the distance between the welding area Q of the pole 10 and the bottom of the welding slot 11 is closer, the small diameter of the first end d1 will not affect the welding beam penetrating the pole 10 and smoothly welding the welding area Q and the collector 40.

[0079] It should be noted that when r' is equal to r, the second slot segment 11b is a straight slot. When r' is greater than r, the second slot segment 11b can be a stepped slot (i.e., the second slot segment 11b includes multiple segments of sub-slots with different diameters) or a tapered slot to gradually increase the diameter of the third end d3 of the second slot segment 11b to the size of r'.

[0080] In some embodiments, reference Figure 4 and Figure 7 The pole 10 includes a first protrusion 12 and a second protrusion 13. The first protrusion 12 is protruded at the first end d1 where the first surface m1 is located along a direction intersecting the thickness direction z, and the second protrusion 13 is protruded at the second end d2 where the second surface m2 is located. The second protrusion 13 can be bent to switch between a first state and a second state. The second protrusion 13 in the first state is protruded along the thickness direction z, and the second protrusion 13 in the second state is protruded along a direction perpendicular to the thickness direction z, and a clamping groove 14 is formed between the first protrusion 12 and the second protrusion 13.

[0081] Figure 4 In the structure shown, the second protrusion 13 is in the second state. Figure 7 In the structure shown, the second protrusion 13 is in the first state.

[0082] In order to facilitate the assembly of the pole 10 at the mounting hole k of the shell 20 of the battery cell 100, and the pole 10 and the shell 20 can be firmly assembled, in actual application, the second protrusion 13 of the pole 10 in the first state is first inserted into the mounting hole k from top to bottom until the second protrusion 13 exceeds the mounting hole k, and the first protrusion 12 and the shell 20 are against each other in the thickness direction z; then the second protrusion 13 is bent to switch it to the second state, and the clamping groove 14 formed between the second protrusion 13 and the first protrusion 12 can clamp the shell 20 therein, so that the pole 10 and the shell 20 are firmly connected.

[0083] The second protrusion 13 in the second state can be substantially parallel to the protrusion direction of the first protrusion 12 as long as they can clamp the housing 20. The first protrusion 12 and the second protrusion 13 are usually but not limited to annularly disposed around the central axis of the welding groove 11.

[0084] When the pole 10 is in the non-assembled state, the second protrusion 13 of the pole 10 can be in the second state or in the first state. If the non-assembled state of the pole 10 is a state in which the second protrusion 13 is in the second state, the second protrusion 13 of the pole 10 can be bent to the first state before insertion. Understandably, when the pole 10 is applied to the battery cell 100, the second protrusion 13 is in the second state. The assembled state of the pole 10 refers to the state in which the pole 10 is assembled on the housing 20.

[0085] Further to the embodiments, refer to Figures 4 to 7 The second surface m2 is concavely formed with a thinning groove 15, and the second convex portion 13 forms part of the groove wall of the thinning groove 15. The setting of the thinning groove 15 is equivalent to reducing the thickness at the bending center of the second convex portion 13, so that the second convex portion 13 is easier to bend. The thinning groove 15 and the second convex portion 13 are usually annular structures.

[0086] In the first specific embodiment of the present application, refer to Figure 4 The pole 10 includes a first surface m1 and a second surface m2 which are arranged opposite to each other in the thickness direction z. The second surface m2 has a welding area Q for welding with the collector plate 40 in the battery cell 100. The first surface m1 is recessed to form a welding groove 11. The welding groove 11 and the welding area Q are arranged opposite to each other in the thickness direction z. Any cross section of the welding groove 11 is circular. The welding groove 11 includes only the first groove section 11a, and the first groove section 11a is in a conical expansion shape, and the diameter R of the first end d1 is greater than the diameter r of the second end d2, and 1.36≥R / r>1.

[0087] In the second specific embodiment of the present application, refer to Figure 5 , which is different from the first specific embodiment in that the first groove segment 11a is in a bowl-shaped expansion shape, the diameter R of the first end d1 thereof is larger than the diameter r of the second end d2 thereof, and 1.29≥R / r>1.

[0088] In the third specific embodiment of the present application, refer to Figure 6 , which is different from the first specific embodiment, is that the welding groove 11 includes the above-mentioned first groove section 11a and also includes a second groove section 11b located below the first groove section 11a, the diameter R of the first end d1 thereof is larger than the diameter r of the second end d2 thereof, and 1.5≥R / r>1, and at the same time, the diameter 1.2≥r' / r≥1 of the third end d3 of the second groove section 11b.

[0089] In addition, the present application embodiment also provides a battery cell 100, referring to Figure 1 , including a housing 20, an electrode assembly 30, a current collecting plate 40 and the pole 10 in the above embodiment, the electrode assembly 30 is loaded in the housing 20, the housing 20 has a mounting hole k, the current collecting plate 40 is located in the housing 20 and is electrically connected to one end of the electrode assembly 30 facing the mounting hole k, the pole 10 is mounted in the mounting hole k, and its welding area Q is welded to the current collecting plate 40. The battery cell 100 includes all the beneficial effects of the above embodiments.

[0090] In addition, an embodiment of the present application further provides a battery, which includes the above-mentioned battery cell 100.

[0091] In addition, an embodiment of the present application further provides an electrical device, which includes the above-mentioned battery, and the battery is used to provide electrical energy.

[0092] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0093] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A pole for a battery cell, characterized in that: The pole comprises: A first surface (m1) and a second surface (m2) are arranged opposite to each other in the thickness direction (z) of the pole, wherein the second surface (m2) is arranged toward the inside of the battery cell and has a welding area (Q) for welding with a current collecting plate (40) in the battery cell; and A welding groove (11), which is recessed and arranged on the first surface (m1) and is arranged corresponding to the welding area (Q) in the thickness direction (z); the welding groove (11) comprises a first groove section (11a), the first groove section (11a) comprises a first end (d1) and a second end (d2) which are arranged in sequence in the thickness direction (z), and the first end (d1) is arranged closer to the first surface (m1) than the second end (d2); The first end (d1) completely exposes the second end (d2), and an opening area of ​​the first end (d1) is larger than an opening area of ​​the second end (d2).

2. The pole according to claim 1, characterized in that: Any cross-sectional shape of the welding groove (11) is circular.

3. The pole according to claim 2, characterized in that: The diameter of the first end (d1) is R, and the diameter of the second end (d2) is r, satisfying: R=a*r, and 1.36≥a>1.

4. The pole according to claim 3, characterized in that: The diameter of the first groove section (11a) decreases gradually from the first end (d1) to the second end (d2).

5. The pole according to claim 3, characterized in that: The diameter of the first groove section (11a) first increases and then decreases from the first end (d1) to the second end (d2); The a satisfies: 1.29≥a>1.

6. The pole according to claim 2, characterized in that: The welding groove (11) further comprises a second groove section (11b), wherein the second groove section (11b) is located at one end of the first groove section (11a) and is connected to the second end (d2) of the first groove section (11a); The second groove section (11b) has a third end (d3) located at the bottom of the welding groove (11), and the diameter r' of the third end (d3) and the diameter r of the second end (d2) satisfy: r≤r'≤1.2r; The a satisfies: 1.5≥a>1.

7. The pole according to any one of claims 1 to 6, characterized in that: The pole comprises a first convex portion (12) and a second convex portion (13), wherein the first convex portion (12) is convexly arranged at a first end (d1) where the first surface (m1) is located, along a direction intersecting the thickness direction (z); and the second convex portion (13) is convexly arranged at a second end (d2) where the second surface (m2) is located; The second convex portion (13) can be bent to switch between a first state and a second state. The second convex portion (13) in the first state is protruding along the thickness direction (z). The second convex portion (13) in the second state is protruding in a direction perpendicular to the thickness direction (z), and a clamping groove (14) is formed between the second convex portion (13) and the first convex portion (12). A thinning groove (15) is formed inwardly on the second surface (m2), and the second convex portion (13) forms part of the groove wall of the thinning groove (15).

8. A battery cell, characterized in that: include: A housing (20) having a mounting hole (k); An electrode assembly (30) is loaded in the housing (20); a current collecting plate (40) located in the housing (20) and electrically connected to an end of the electrode assembly (30) facing the mounting hole (k); and The pole according to any one of claims 1 to 7, wherein the pole is mounted in the mounting hole (k), and the welding area (Q) thereof is welded to the collecting plate (40).

9. A battery, characterized in that: Comprising the battery cell as claimed in claim 8.

10. An electrical device, characterized in that: Comprising a battery as claimed in claim 9, the battery is used to provide electrical energy.

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