Cylindrical battery and electric equipment

Abstract

The invention relates to the field of batteries, and provides a cylindrical battery and electric equipment.The cylindrical battery comprises a roll core, a first current collecting disc and a second current collecting disc, the roll core comprises a tab part arranged at the axial end of the roll core, the first current collecting disc is attached and welded to the tab part, the second current collecting disc is attached and welded to the first current collecting disc, and the first current collecting disc is connected with the second current collecting disc. The thickness of the first flow collecting plate is smaller than that of the second flow collecting plate. According to the technical scheme, the two layers of current collecting plates are arranged, the thickness of the first current collecting plate directly welded to the tab part is small, the needed welding power is relatively low, the number of stacked tabs of the tab part is allowed to be small, the weldable area is increased, the thickness of the second current collecting plate welded to the first current collecting plate is larger, and the welding efficiency is improved. Enough overcurrent capability is ensured, temperature rise in the charging and discharging process is reduced, and the power capability of the battery is improved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of batteries, and in particular to a cylindrical battery and an electrical device. Background Art

[0002] As a typical example of high-energy-density energy carriers, cylindrical batteries' power performance breakthroughs rely heavily on the low internal resistance advantages of a full-tab structure. During industrialization, the industry primarily utilizes two processes: tab flattening and cutting and stacking. However, both processes present core technical bottlenecks that hinder battery performance improvements.

[0003] The flattening process, which mechanically deforms the tabs, can easily cause the metal foil to break, producing micron-sized debris, increasing the risk of micro-shorts within the battery. The cutting and stacking process doesn't create this problem, but because the tabs need to be bent and flattened, the multi-layered tabs present a trapezoidal cross-section from the center to the edge of the winding core. This results in areas at the center and edges where there are no tabs or the tabs can't be effectively welded to the collector plate. This has a serious negative impact on the weldable area between the tabs and the collector plate, affecting the current carrying capacity and, in turn, the battery's power capability. Summary of the Invention

[0004] A technical problem to be solved by the present disclosure is: how to increase the welding area between the tab and the current collecting plate to ensure the flow capacity.

[0005] To solve the above technical problems, an embodiment of the present disclosure provides a cylindrical battery, which includes a winding core, a first current collecting disk, and a second current collecting disk. The winding core includes a pole ear portion arranged at its axial end, the first current collecting disk is adhered and welded to the pole ear portion, and the second current collecting disk is adhered and welded to the first current collecting disk. The thickness of the first current collecting disk is less than the thickness of the second current collecting disk.

[0006] In some embodiments, the first current collecting disc is provided with a boss portion, the boss portion protrudes toward one side of the second current collecting disc, and the second current collecting disc is welded to the boss portion.

[0007] In some embodiments, the first current collecting disk is provided with a plurality of circumferentially spaced bosses, and the bosses are formed into circumferentially extending strips, circles, or squares. Preferably, the number of the bosses is an odd number.

[0008] In some embodiments, the height of the boss portion is 0.2 mm to 1.0 mm, and the width of the boss portion along the radial direction is 3 mm to 5 mm.

[0009] In some embodiments, the first current collecting plate is provided with a radially extending strip-shaped welding area, and the strip-shaped welding area is provided with continuous welding strips or welding points arranged at intervals.

[0010] In some embodiments, the angle between adjacent strip-shaped welding areas is 20-70°.

[0011] In some embodiments, the distance between the innermost end of the strip welding area in the radial direction and the edge of the center hole of the winding core is less than or equal to 4 mm, and / or the distance between the outermost end of the strip welding area in the radial direction and the outer peripheral edge of the winding core is less than or equal to 4 mm.

[0012] In some embodiments, the second current collecting plate is provided with a plurality of positioning portions arranged at intervals in the circumferential direction, and the positioning portions face between adjacent boss portions.

[0013] In some embodiments, the second current collecting disk is provided with a recessed portion, which is recessed on a side facing away from the first current collecting disk and protrudes toward a side of the first current collecting disk. The plurality of bosses surround the recessed portion and restrict lateral movement of the recessed portion.

[0014] In some embodiments, the thickness of the first current collecting disk is 0.05 mm-0.2 mm, and the thickness of the second current collecting disk is 0.4 mm-1.0 mm.

[0015] In some embodiments, the first collecting disc is annular in shape, and / or the second collecting disc is annular or disc-shaped; preferably, the outer diameter of the first collecting disc is greater than the outer diameter of the second collecting disc.

[0016] In some embodiments, the tab portion includes a plurality of tabs that are bent radially inward and stacked, the length of the tabs is 5-7 mm, and the number of stacked tabs does not exceed 15 layers.

[0017] On the other hand, an embodiment of the present disclosure provides an electrical device, which includes the cylindrical battery described in the above solution.

[0018] Through the above technical solution, a two-layer current collecting plate is set up. The first current collecting plate directly welded to the pole ear has a smaller thickness and requires relatively lower welding power, allowing the number of pole ear layers in the pole ear to be smaller, thereby increasing the weldable area. The second current collecting plate welded to the first current collecting plate has a larger thickness, ensuring sufficient current flow capacity, reducing the temperature rise during charging and discharging, and improving the power capacity of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0020] Figure 1 is a cross-sectional view of a partial structure of a cylindrical battery disclosed in an embodiment of the present disclosure;

[0021] Figure 2 2 is a schematic structural diagram of a first current collecting plate and a second current collecting plate disclosed in an embodiment of the present disclosure;

[0022] Figure 3 is a structural schematic diagram of a first current collecting plate disclosed in an embodiment of the present disclosure;

[0023] Figure 4 is a structural schematic diagram of another example of the first current collecting plate disclosed in an embodiment of the present disclosure;

[0024] Figure 5 is a structural schematic diagram of another example of a second current collecting plate disclosed in an embodiment of the present disclosure;

[0025] Figure 6 It is a schematic structural diagram of the winding core and the pole ear part disclosed in the embodiment of the present disclosure.

[0026] Description of reference numerals:

[0027] 10-first current collecting disc, 11-boss, 12-strip welding area, 20-second current collecting disc, 21-positioning portion, 22-recessed portion, 30-winding core, 31-pole ear, 40-insulating glue, 50-pole, 60-housing, 70-lower plastic, 80-upper plastic, 90-sealing ring. DETAILED DESCRIPTION

[0028] The following embodiments of the present disclosure are further described in detail with reference to the accompanying drawings and examples. The detailed description of the following examples and the accompanying drawings are intended to illustrate the principles of the present disclosure, but are not intended to limit the scope of the present disclosure. The present disclosure can be implemented in many different forms and is not limited to the specific embodiments disclosed herein, but rather includes all technical solutions within the scope of the claims.

[0029] The present disclosure provides these embodiments in order to make this disclosure thorough and complete, and to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that: unless otherwise specifically stated, the relative arrangement of parts and steps, the composition of materials, numerical expressions and numerical values set forth in these embodiments should be interpreted as merely exemplary, and not as limiting.

[0030] It should be noted that, in the description of this disclosure, unless otherwise specified, "plurality" means greater than or equal to two; terms such as "upper," "lower," "left," "right," "inner," and "outer" indicating directions or positional relationships are intended solely to facilitate and simplify the description of this disclosure, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this disclosure. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0031] In addition, the terms "first," "second," and similar terms used in this disclosure do not denote any order, quantity, or importance, but are merely used to distinguish different parts. "Perpendicular" does not mean perpendicular in the strict sense, but rather means within the tolerance range. "Parallel" does not mean parallel in the strict sense, but rather means within the tolerance range. "Include" or "comprising" and similar terms mean that the elements preceding the term include the elements listed after the term, and do not exclude the possibility of also including other elements.

[0032] It should also be noted that, in the description of this disclosure, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to direct connections or indirect connections through an intermediary. Those skilled in the art will understand the specific meanings of the above terms in this disclosure depending on the specific circumstances. When a specific device is described as being located between a first device and a second device, there may or may not be an intervening device between the specific device and the first or second device.

[0033] All terms used in this disclosure have the same meaning as understood by one of ordinary skill in the art to which this disclosure belongs, unless otherwise specifically defined. It should also be understood that terms defined in, for example, common dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and should not be interpreted in an idealized or highly formal sense, unless explicitly defined as such herein.

[0034] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0035] refer to Figure 1-Figure 5As shown, the present disclosure provides a cylindrical battery, which includes a winding core 30, a first current collecting disc 10, and a second current collecting disc 20. The winding core 30 includes a pole ear portion 31 arranged at its axial end, the first current collecting disc 10 is adhered to and welded to the pole ear portion 31, and the second current collecting disc 20 is adhered to and welded to the first current collecting disc 10. The thickness of the first current collecting disc 10 is less than the thickness of the second current collecting disc 20.

[0036] In the present disclosure, a two-layer current collecting disk is provided, wherein the first current collecting disk 10 directly welded to the pole ear portion 31 has a smaller thickness. Therefore, the required welding power is relatively lower, allowing the pole ear portion 31 to have a smaller number of pole ear stacking layers, thereby increasing the weldable area. The second current collecting disk 20 welded to the first current collecting disk 10 has a larger thickness, ensuring sufficient current flow capacity, reducing the temperature rise during charging and discharging, and improving the power capacity of the battery.

[0037] The winding core 30 can be formed by winding the pole piece assembly, and the end thereof has a pole ear portion 31 formed by a plurality of pole ears. The pole ears are bent radially inward to form a stacked structure. Since the stacking number of the radial inner edge and the radial outer edge is small, the cross-sectional shape of the pole ear portion 31 is a trapezoid (such as Figure 6 As shown, the top edge of the trapezoid serves as the surface for welding to the first current collecting disc. It is understood that the smaller the maximum number of tabs stacked, the wider the top edge of the trapezoid, i.e., the larger the welding area with the first current collecting disc. Of course, the smaller the height of the trapezoid, i.e., the smaller the thickness of the tab stack.

[0038] To prevent the heat generated during welding from burning the diaphragm in the winding core 30, the tab stack thickness must meet certain requirements. Furthermore, the greater the welding power, the greater the required tab stack thickness and the smaller the tab weld area. Therefore, the thinner the first current collecting disc 10, the less power required for welding, and the less heat transferred to the winding core 30, allowing for a thinner tab stack thickness. In other words, because the thinner the first current collecting disc 10, the less power required for welding, the thinner the tab stack thickness can be, thereby increasing the welding area of the tab 31 and improving current handling capacity.

[0039] It is understood that the welding surface of the tab portion 31 is an annular surface. Since the number and thickness of the tab stacked in this embodiment are reduced, the area of the annular surface increases, that is, the distance between the outer edge and the inner edge (the top edge of the trapezoid described above) increases. In a specific embodiment of the present disclosure, by adopting the technical solution of the present disclosure, the annular surface of the tab portion 31 is changed from the original inner radius of 8mm and the outer radius of 18mm to the inner radius of 6mm and the outer radius of 22mm, thereby improving the flow capacity by approximately 66% and reducing the internal resistance by 10-20%, for example, from the original 1.2mΩ to approximately 1.0mΩ.

[0040] In order to match the end surface shape of the winding core 30 , the overall shape of the first collecting disk 10 may be annular, and the shape of the second collecting disk 20 may be annular or disc-shaped.

[0041] In the present disclosure, the first current collecting disc 10 can be welded to the pole ear portion 31 of the winding core 30 using a relatively small welding power, and then the second current collecting disc 20 can be welded to the first current collecting disc 10. This can not only make the pole ear portion 31 have a larger welding area, but also make the second current collecting disc 20 have sufficient current flow capacity, thereby improving the performance of the battery.

[0042] In some embodiments, the first current collecting disc 10 is provided with a boss portion 11, which protrudes toward one side of the second current collecting disc 20, and the boss portion 11 is welded to the second current collecting disc 20. The first current collecting disc 10 partially protrudes toward the second current collecting disc 20 to form the boss portion 11. The boss portion 11 can be formed by a stamping process for the first current collecting disc 10. Of course, the first current collecting disc 10 with the boss portion 11 can also be directly cast to form the first current collecting disc 10. The boss portion 11 can make the first current collecting disc 10 and the second current collecting disc 20 fit together more tightly, ensuring the welding quality of the two. In addition, since there is a gap between the boss portion 11 and the pole ear portion 31, the heat transfer to the pole ear portion 31 can be reduced during welding, thereby avoiding or reducing burns to the diaphragm. The second collecting disc 20 and the boss portion 11 can be welded by laser welding. For example, after the second collecting disc 20 is tightly fitted to the first collecting disc 10, the surface of the overlapping portion of the second collecting disc 20 and the boss portion 11 is heated by laser, so that the second collecting disc 20 and the boss portion 11 are melted and welded together.

[0043] In some embodiments, the first collecting plate 10 is provided with a plurality of circumferentially spaced bosses 11, and the bosses 11 are formed into a circumferentially extending strip. Figure 3 and Figure 4 As shown, the boss portions 11 are distributed at intervals in the circumferential direction, and the boss portions 11 are generally strip-shaped, for example, Figure 3 The arc strip shown, or Figure 4 In other embodiments, the boss portion 11 may also be in other shapes, such as a circular shape, a square shape, etc. Preferably, the boss portion 11 is arranged at the midpoint of the radius of the first collecting disc 10 in the radial direction.

[0044] In some embodiments, the number of bosses 11 is an odd number; and / or the height of the bosses 11 is 0.2 mm to 1.0 mm, and the radial width of the bosses 11 is 3 mm to 5 mm. The bosses 11 can also serve as reinforcing ribs, and an odd number of bosses 11 is less susceptible to deformation than an even number of bosses 11. The height of the bosses 11 can be 0.2 mm, 0.4 mm, 0.6 mm, 0.8 mm, 1.0 mm, etc., and the radial width can be 3 mm, 4 mm, 5 mm, etc.

[0045] In some embodiments, the first current collecting disc 10 is provided with a radially extending strip-shaped welding area 12, and the strip-shaped welding area 12 is provided with a continuous welding band or spaced welding points. The welding of the first current collecting disc 10 to the pole lug 31 can be achieved by laser welding or pulse welding, that is, after the first current collecting disc 10 is attached to the pole lug 31, the surface of the first current collecting disc 10 is welded. The continuous welding band can be achieved by laser welding, and the spaced welding points can be achieved by pulse welding. Figure 3 As shown, the strip-shaped welding areas 12 can be arranged between adjacent boss portions 11 , or some of the strip-shaped welding areas 12 can be divided into two sections by the boss portion 11 , that is, they are arranged on the radial inner side and the radial outer side of the boss portion 11 .

[0046] In some embodiments, the angle between adjacent strip-shaped welding areas 12 is 20-70°. For example, the angle between two adjacent strip-shaped welding areas 12 can be 20°, 30°, 40°, 50°, 60°, 70°, etc. The strip-shaped welding areas 12 are distributed around the circumference of the first current collecting tray 10 at appropriate intervals to ensure the welding strength between the first current collecting tray 10 and the winding core 30.

[0047] In some embodiments, the distance between the innermost end of the strip-shaped welding area 12 in the radial direction and the edge of the central hole of the winding core 30 is less than or equal to 4 mm, and / or the distance between the outermost end of the strip-shaped welding area 12 in the radial direction and the outer peripheral edge of the winding core 30 is less than or equal to 4 mm. Figure 3 As shown, the various welding points of the strip welding area 12 extend in the radial direction of the first collecting disk 10, and the distance between the radial inner end and the edge of the center hole of the winding core 30 is maintained within 4 mm, and the distance between the radial outer end and the outer peripheral edge of the winding core 30 is also maintained within 4 mm. In other words, the distance between these welding points and the inner and outer peripheral surfaces of the center hole of the winding core 30 is small, and they try to cover most of the area in the radial direction of the annular end face of the winding core 30 to ensure the welding area and welding strength.

[0048] In some embodiments, the second collecting plate 20 is provided with a plurality of positioning portions 21 arranged at intervals in the circumferential direction, and the positioning portions 21 face between adjacent boss portions 11. The positioning portions 21 are used to position the second collecting plate 20 and the first collecting plate 10 in the circumferential direction. The positioning portions 21 can be through holes facing between two adjacent boss portions 11, so that the position of the boss portion 11 can be accurately determined when the second collecting plate 20 is welded to the first collecting plate 10. In other embodiments, refer to Figure 5 As shown, the positioning portion 21 can be a radially extending protrusion structure, which is inserted between adjacent boss portions 11 and can also play a circumferential positioning role. It can be formed by a stamping process. In other embodiments, the positioning portion 21 can also be a protrusion structure of other shapes, such as square, circular, etc.

[0049] In some embodiments, the second collecting tray 20 is provided with a recessed portion 22, which is recessed on a side facing away from the first collecting tray 10 and protrudes toward the side of the first collecting tray 10. Multiple bosses 11 surround the recessed portion 22 and restrict its lateral movement. The recessed portion 22 can be accommodated in the space enclosed by the bosses 11. The edges of the recessed portion 22 contact the bosses 11, which act as lateral limiters, limiting lateral movement of the recessed portion 22. Specifically, the recessed portion 22 can be stamped from the first collecting tray 10 relative to the first collecting tray 10 (perpendicular to the axial direction of the winding core 03).

[0050] Among them, reference Figure 2 As shown, when the boss portion 11 is an arc-shaped strip, multiple boss portions 11 enclose a circular restricted space, and the cross section of the recessed portion 22 is also circular to be accommodated in the restricted space enclosed by the boss portion 11. The boss portion 11 can limit the lateral movement of the recessed portion 22; similarly, refer to Figure 4 As shown, when the boss portion 11 is in a straight strip shape, the multiple boss portions 11 enclose a polygonal restricted space, and the cross-section of the recessed portion 22 is also formed into a corresponding polygonal shape to be accommodated within the polygonal restricted space enclosed by the boss portions 11. Of course, when the boss portion 11 is in a straight strip shape, the cross-section of the recessed portion 22 can also be circular, and the recessed portion 22 can simply form a transverse limiting relationship with the multiple boss portions 11.

[0051] In some embodiments, the first collecting tray 10 is made of H-state Al1060, and the second collecting tray 20 is made of H-state Al1060 or O-state Al1060; and / or the thickness of the first collecting tray 10 is 0.05 mm to 0.2 mm, and the thickness of the second collecting tray 20 is 0.4 mm to 1.0 mm. The first collecting tray 10 can be made of H-state Al1060 to ensure strength at a smaller thickness, while the second collecting tray 02 can be made of H-state Al1060 or O-state Al1060, preferably O-state Al1060, which has slightly better conductivity than H-state Al1060. The thickness of the first collecting tray 10 can be 0.05 mm, 0.10 mm, 0.15 mm, or 0.20 mm, and the thickness of the second collecting tray 20 can be 0.4 mm, 0.6 mm, 0.8 mm, or 1.0 mm. In the prior art, a conventional 0.3mm collecting disc requires a welding power of about 360W, while a 0.4mm collecting disc requires a welding power of about 420W. Reducing the thickness by 0.1mm can reduce the welding power by 60W. Therefore, after the thickness of the first collecting disc 10 is reduced, the welding power can be reduced to 200-300W; and the thickness of the second collecting disc 20 can be 0.5mm or even larger, thereby increasing its current flow capacity by about 66%.

[0052] In some embodiments, the first collecting disc 10 is annular, and / or the second collecting disc 20 is annular or disc-shaped; preferably, the outer diameter of the first collecting disc 10 is larger than the outer diameter of the second collecting disc 20. The overall shape of the first collecting disc 10 is annular, and the second collecting disc 20 can be disc-shaped or annular, for example, with a through hole formed in the center of the recessed portion 22. In addition, the outer diameter of the second collecting disc 20 can be smaller than the outer diameter of the first collecting disc 10, for reference. Figure 1 As shown, the protruding portion of the lower plastic 70 can be pressed against the outer ring portion of the first collecting disc 10 that is not covered by the second collecting disc 20, thereby pressing the winding core 30, which can better prevent the winding core 30 from moving in the shell 60, and the second collecting disc 20 is located radially inward of the protruding portion of the lower plastic 70, does not occupy the effective space in the height direction, and also reduces the volume of the second collecting disc 20, thereby reducing the material cost.

[0053] In some embodiments, the tab portion 31 includes a plurality of tabs that are bent radially inward and stacked, the length of the tabs being 5-7 mm, and the number of stacked tabs not exceeding 15. The winding core 30 can be formed by winding a tab assembly consisting of a positive electrode sheet, a negative electrode sheet, and two layers of separators, and then flattening the tabs so that the tabs are bent radially inward, and multiple tabs can be stacked together. n is the number of tab stacks, H C is the thickness of the positive electrode sheet, H Ais the thickness of the negative electrode sheet, H S is the thickness of the diaphragm, L is the length of the tab (the length of the tab's inwardly bent portion). According to the calculation formula, it can be known that the number of layers of the tab assembly that the tab's length can span is the number of tab stacking layers n. In other words, in the axial direction, the maximum number of tab stacking layers is n, and the number of stacking layers of the radially inner edge and the radially outer edge is less than n. At the position where the tab can be stacked to the maximum number, the top surface of the tab portion 31 is a plane; the portion where the radially inner edge and the radially outer edge are less than the maximum number has an inclined top surface, and the overall cross-section is a trapezoid (reference Figure 6 As shown). The thicknesses of the positive electrode sheet, the negative electrode sheet and the two layers of the separator are fixed. Due to the reduction in welding power, the axial dimension of the pole ear portion 31 can be allowed to be smaller, that is, n can be smaller, and the length L of the pole ear is also smaller. After the maximum number of stacking of the pole ear is reduced, the radial dimension of the portion of the radial inner edge and the radial outer edge that is less than the maximum number of stacking is reduced. Accordingly, the radial dimension of the portion that can reach the maximum number of stacking is increased, that is, the radial dimension of the top plane of the pole ear portion 31 is larger, the welding area is increased, and the flow capacity is improved. The pole ear length in the prior art is 8-10mm, while in this solution, the length L of the pole ear can be 5-7mm, which is significantly shortened. Accordingly, the number of pole ear stacking can also be reduced. The number of pole ear stacking is reduced from the conventional 20 layers to no more than 15 layers, reducing the axial dimension of the pole ear portion 31 and increasing the pole ear welding area to improve the flow capacity.

[0054] refer to Figure 1 As shown, the cylindrical battery includes a shell 60, a pole 50, an insulating glue 40, a lower plastic 70, an upper plastic 80, and a sealing ring 90. The winding core 30 is accommodated in the shell 60, and the pole 50 is welded to the second collecting disk 20. The insulating glue 40 is adhered to the intersection of the outer circumference and the end surface of the winding core 30 to form insulation between the winding core 30 and the shell 60. The lower plastic 70 is located on the inner surface of the end of the shell 60 to isolate the end plate of the shell 60 from the second collecting disk 20 and the pole 50. The upper plastic 80 is located on the outer surface of the end plate of the shell 60 to isolate the end plate of the shell 60 and the pole 50. The sealing ring 90 is located in the through hole of the end plate of the shell 60 and surrounds the pole 50 to seal the gap between the two.

[0055] In another aspect, the present disclosure further provides an electrical device comprising the cylindrical battery described above. The electrical device may be a battery pack, an energy storage device, a new energy vehicle, etc., without particular limitation herein.

[0056] Thus far, various embodiments of the present disclosure have been described in detail. To avoid obscuring the concept of the present disclosure, some details known in the art have not been described. Based on the above description, those skilled in the art can fully understand how to implement the technical solutions disclosed herein.

[0057] Although some specific embodiments of the present disclosure have been described in detail through examples, those skilled in the art will understand that the above examples are for illustrative purposes only and are not intended to limit the scope of the present disclosure. Those skilled in the art will understand that the above embodiments may be modified or some technical features may be replaced with equivalents without departing from the scope and spirit of the present disclosure. In particular, as long as there are no structural conflicts, the various technical features mentioned in the various embodiments may be combined in any manner.

Claims

1. A cylindrical battery, characterized in that: The invention comprises a winding core (30), a first current collecting disc (10), and a second current collecting disc (20); the winding core (30) comprises a pole ear portion (31) arranged at an axial end thereof; the first current collecting disc (10) is adhered to and welded to the pole ear portion (31); the second current collecting disc (20) is adhered to and welded to the first current collecting disc (10); and the thickness of the first current collecting disc (10) is less than the thickness of the second current collecting disc (20).

2. The cylindrical battery according to claim 1, characterized in that: The first current collecting disc (10) is provided with a boss portion (11), the boss portion (11) protruding toward one side of the second current collecting disc (20), and the second current collecting disc (20) is welded to the boss portion (11).

3. The cylindrical battery according to claim 2, characterized in that: The first collecting plate (10) is provided with a plurality of circumferentially spaced bosses (11), and the bosses (11) are formed into circumferentially extending strips, circles, or squares. Preferably, the number of the bosses (11) is an odd number.

4. The cylindrical battery according to claim 2, characterized in that: The height of the boss portion (11) is 0.2 mm to 1.0 mm, and the width of the boss portion (11) in the radial direction is 3 mm to 5 mm.

5. The cylindrical battery according to claim 1, characterized in that: The first current collecting plate (10) is provided with a radially extending strip-shaped welding area (12), and the strip-shaped welding area (12) is provided with continuous welding strips or welding points arranged at intervals.

6. The cylindrical battery according to claim 5, characterized in that: The included angle between adjacent strip-shaped welding areas (12) is 20-70°.

7. The cylindrical battery according to claim 5, characterized in that: The distance between the innermost end of the strip welding area (12) in the radial direction and the edge of the center hole of the winding core (30) is less than or equal to 4 mm, and / or the distance between the outermost end of the strip welding area (12) in the radial direction and the outer peripheral edge of the winding core (30) is less than or equal to 4 mm.

8. The cylindrical battery according to claim 3, characterized in that: The second current collecting plate (20) is provided with a plurality of positioning portions (21) arranged at intervals in the circumferential direction, and the positioning portions (21) face between adjacent boss portions (11).

9. The cylindrical battery according to claim 3, characterized in that: The second current collecting disc (20) is provided with a recessed portion (22), the recessed portion (22) being recessed on a side facing away from the first current collecting disc (10) and protruding toward a side of the first current collecting disc (10), and the plurality of boss portions (11) surrounding the recessed portion (22) and limiting lateral movement of the recessed portion (22).

10. The cylindrical battery according to claim 1, characterized in that: The thickness of the first current collecting disc (10) is 0.05 mm to 0.2 mm, and the thickness of the second current collecting disc (20) is 0.4 mm to 1.0 mm.

11. The cylindrical battery according to claim 1, characterized in that: The first current collecting disc (10) is annular in shape, and / or the second current collecting disc (20) is annular or disc-shaped; Preferably, the outer diameter of the first collecting disc (10) is greater than the outer diameter of the second collecting disc (20).

12. The cylindrical battery according to claim 1, characterized in that: The pole lug portion (31) comprises a plurality of pole lugs that are bent radially inward and stacked, the length of the pole lugs is 5-7 mm, and the number of stacked pole lugs does not exceed 15 layers.

13. An electrical device, characterized in that: A cylindrical battery comprising the cylindrical battery according to any one of claims 1 to 12.

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