Cylindrical battery and electric equipment

Abstract

The cylindrical battery comprises a battery cell, the battery cell is a full-tab roll core and comprises a coating part and an empty foil part, the empty foil part is close to the outer edge of one end of the full-tab roll core in the first direction, the empty foil part comprises a plurality of pieces of empty foil materials which are adjacently arranged in the second direction, and the coating part is arranged on the outer edge of the other end of the full-tab roll core in the second direction. One part of the empty foil has a first height, and the other part of the empty foil has a second height; the current collector comprises a body and a lug boss; wherein the empty foil with the first height is connected with the body, and the empty foil with the second height is connected with the protruding part through laser heat conduction welding. According to the cylindrical battery disclosed by the utility model, the hollow foil part with the height difference and the current collector with the height difference are arranged, so that the connecting area and the connecting tightness between the end surface of the hollow foil part and the end surface of the current collector can be increased, the welding area of laser thermal conduction welding is larger, the welding is tighter, and the welding quality is improved. And therefore, the process effect of laser heat conduction welding is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and more specifically, to a cylindrical battery and electrical equipment. Background Art

[0002] Cylindrical batteries, with their advantages of high structural strength, consistent process, directional pressure relief, and lack of heat spread, have become a hot research topic in the power battery field. The resulting demand places higher demands on the power performance of cylindrical cells.

[0003] However, traditional cylindrical battery cells use tabs to connect the core and shell / cap to achieve electrical connection, and the thickness and width of the tabs themselves limit the current capacity of the battery cell structure.

[0004] To this end, the industry has proposed the following solutions to improve the overcurrent capacity of cylindrical battery cells:

[0005] (1) Multi-tab solution: This solution aims to improve the cell's current capacity by increasing the number of tabs. However, this solution cannot meet the requirements of high-rate charge and discharge because the process difficulty increases significantly with the number of tabs.

[0006] (2) Tab-kneading solution: Empty positive and negative foils are left at each end of the coil, and the empty foil areas are compressed into a solid core through physical processing. A collector plate is then welded to the compressed empty foil areas to provide electrical connections. The problem with this solution is that the compression of the empty foil areas may generate metal particles, which can easily cause internal short circuits in the battery, posing a safety risk.

[0007] (3) Cut and stack tab (full tab) solution: The empty foil at the end of the core is cut into strips perpendicular to the winding direction. During winding, the folded and cut empty foil areas are stacked and compacted, and then welded to the collector plate to lead out the electrical connection. The problems with this solution are: the die-cut tab process is difficult, and efficiency and yield are difficult to guarantee; the flatness of the compacted empty foil area is poor, which limits the subsequent collector plate welding process.

[0008] In addition, the above-mentioned solution usually uses laser penetration welding to connect the tabs and the current collecting plate. The temperature in the welding area is relatively high, which causes greater damage to the winding core, and the yield of the final product is low. Utility Model Content

[0009] One purpose of the present invention is to provide a cylindrical battery that can at least solve the technical problems of the prior art in which the tabs and the current collecting plate are connected by laser penetration welding, the welding area temperature is high, the damage to the winding core is also great, and the yield of the final product is low.

[0010] Another object of the present invention is to provide an electrical device comprising the cylindrical battery.

[0011] In order to achieve the above objectives, the present utility model provides the following technical solutions.

[0012] According to the cylindrical battery of the embodiment of the first aspect of the present invention, it includes: a battery core, which is a full-tab core with a central axis extending along a first direction, the full-tab core including a coated portion coated with active material and a hollow foil portion not coated with active material, the hollow foil portion is close to the outer edge of one end of the full-tab core in the first direction, the hollow foil portion includes a plurality of hollow foils arranged adjacent to each other in a second direction, the second direction is non-parallel to the first direction, in the first direction, a part of the hollow foils has a first height, and another part of the hollow foils has a second height, the first height is greater than the second height; a current collector, the current collector includes a main body and a raised portion, the raised portion protruding from one side surface of the main body; wherein the hollow foil with the first height is connected to the main body, and the hollow foil with the second height is connected to the raised portion by laser thermal welding.

[0013] Optionally, the raised portion includes: a first connecting portion and a second connecting portion, the first connecting portion is a ring-shaped member, one end of the first connecting portion is connected to the body along the first direction, the second connecting portion closes the other end of the first connecting portion, and the second connecting portion and the first connecting portion cooperate to form a groove.

[0014] Optionally, in the first direction, both side surfaces of the second connecting portion are planes, and the thickness of the second connecting portion is 0.1 mm-0.4 mm.

[0015] Optionally, the current collector is the outer shell or current collecting disk of the cylindrical battery.

[0016] Optionally, there are multiple raised portions on one body, and the multiple raised portions are distributed spaced apart around the first direction; and / or, the outer contour of the raised portion is a trapezoid or a rectangle, and when the outer contour is a trapezoid, the short side of the trapezoid is close to the central axis of the full-electrode winding core, and when the outer contour is a rectangle, the two ends of the rectangle are straight sides or semicircular sides.

[0017] Optionally, the current collector is a one-piece piece.

[0018] Optionally, the empty foil material having the second height includes: a first segment, the first segment extending along the first direction; a second segment, the second segment extending along the second direction, and one end of the second segment in the second direction is connected to the first segment, and the end surface of the second segment in the first direction is connected to the surface of the raised portion by laser thermal welding.

[0019] Optionally, in the first direction, the protrusion has a height d, and in the second direction, there is a gap D between two adjacent layers of the hollow foil, where d>D.

[0020] The electrical device according to the second embodiment of the present invention includes any of the above-mentioned cylindrical batteries.

[0021] According to the embodiment of the utility model, the cylindrical battery is mainly composed of a battery cell and a current collector. On the one hand, by adopting a full-tab winding core, the connection area between the tab and the current collector can be expanded, thereby improving the current flow capacity of the battery cell; on the other hand, by providing a hollow foil portion with a height difference and a current collector with a height difference, the connection area and connection tightness between the end face of the hollow foil portion and the end face of the current collector can be increased, that is, the connection area and connection tightness between the end face welding area of ​​the hollow foil portion and the end face of the current collector can be increased, thereby improving the process effect of laser thermal conductivity welding.

[0022] Other features and advantages of the present invention will become apparent from the following detailed description of exemplary embodiments of the present invention with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0024] Figure 1 Schematic diagram of the winding of a cylindrical battery cell according to one embodiment of the present invention;

[0025] Figure 2 This is a schematic diagram of the installation of the current collector and the empty foil portion according to one embodiment of the present utility model;

[0026] Figure 3 Schematic diagram of a current collector extruding a partially hollow foil according to an embodiment of the present invention;

[0027] Figure 4 This is a schematic diagram of a current collector and a hollow foil portion being connected by laser thermal welding according to an embodiment of the present invention;

[0028] Figure 5 This is a schematic diagram of a process for connecting a current collector and a hollow foil portion by laser thermal welding according to an embodiment of the present invention;

[0029] Figure 6 A schematic diagram of the laser penetration welding process in the prior art;

[0030] Figure 7 This is a schematic structural diagram of a cylindrical battery according to an embodiment of the present invention at one angle;

[0031] Figure 8 FIG1 is a structural schematic diagram of a cylindrical battery according to an embodiment of the present invention from another angle;

[0032] Figure 9 A partial exploded view of a cylindrical battery according to one embodiment of the present invention;

[0033] Figure 10 It is a vertical cross-sectional view of a cylindrical battery according to one embodiment of the present invention.

[0034] Figure Numbers

[0035] Battery cell 1; coating portion 11; hollow foil portion 12; hollow foil material 121; first segment 1211; second segment 1212; first diaphragm 13; second diaphragm 14;

[0036] Current collector 2; body 21; first surface 211; second surface 212; protrusion 22; first connecting portion 221; second connecting portion 222; groove 223;

[0037] Top cover 3;

[0038] Outer shell 4;

[0039] Molten pool a'; effective welding area b';

[0040] Molten pool a; effective welding zone b; heat affected zone c;

[0041] First height H1; second height H2. DETAILED DESCRIPTION

[0042] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that unless otherwise specifically stated, the relative arrangements of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention.

[0043] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the present invention, its application, or uses.

[0044] 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.

[0045] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0046] It should be noted that like reference numerals and letters refer to like items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0047] The cylindrical battery according to the embodiment of the present invention is described in detail below with reference to the accompanying drawings.

[0048] like Figures 1 to 5 ,as well as Figures 7 to 10 As shown, the cylindrical battery according to an embodiment of the present invention includes: a battery cell 1 and a current collector 2.

[0049] Specifically, the battery cell 1 is a full-tab core with a central axis extending along a first direction. The full-tab core includes a coated portion 11 coated with active material and a hollow foil portion 12 not coated with active material. The hollow foil portion 12 is located near the outer edge of one end of the full-tab core in the first direction. The hollow foil portion 12 includes multiple hollow foils 121 arranged adjacent to each other in a second direction, which is non-parallel to the first direction. In the first direction, a portion of the hollow foils 121 has a first height H1, and another portion of the hollow foils 121 has a second height H2, where the first height H1 is greater than the second height H2. The current collector 2 includes a main body 21 and a raised portion 22, which protrudes from one side surface of the main body 21. The hollow foil 121 with the first height H1 is connected to the main body 21, and the hollow foil 121 with the second height H2 is connected to the raised portion 22 by laser thermal welding.

[0050] In other words, the cylindrical battery according to the embodiment of the present invention is mainly composed of a battery cell 1 and a current collector 2, wherein the battery cell 1 is a full-tab winding core, and the full-tab winding core can be prepared by winding, for example, by Figure 1 The multi-layer electrode sheet is wound in the winding direction indicated by the arrow in the figure. The electrode sheet can be a positive electrode sheet or a negative electrode sheet. A separator is also provided between the positive and negative electrodes to effectively prevent the positive and negative electrodes from short-circuiting. When making a full-tab core, the positive electrode sheet, separator, and negative electrode sheet can be stacked and then wound to form a full-tab core.

[0051] It can be understood that along the axial direction of the full-electrode tab core, that is, the first direction, the full-electrode tab core includes adjacently arranged coating portions 11 and empty foil portions 12. The empty foil portion 12 of the positive electrode can be used as a positive electrode tab, and the empty foil portion 12 of the negative electrode can be used as a negative electrode tab. Moreover, each layer of the electrode sheet includes adjacently arranged coating portions 11 and empty foil portions 12. Among them, the surface of the coating portion 11 is provided with an active material coated, and the surface of the empty foil portion 12 is not coated with an active material. For example, the flattened positive electrode sheet and negative electrode sheet can be provided with empty foil portions 12 that are not coated with positive and negative active materials at both side ends in the first direction, respectively. In addition, during coating, continuous coating can be adopted for both the positive electrode sheet and the negative electrode sheet, that is, no gap is set along the winding direction.

[0052] Furthermore, multiple layers of hollow foil 121 are formed by winding in the second direction, i.e., the hollow foil portion 12 includes multiple hollow foils 121 sequentially arranged along the second direction. The axial direction of the full tab winding core may be the first direction, and the winding direction may be the second direction. The first direction and the second direction are non-parallel, i.e., there is an angle between them, for example, the first direction and the second direction are perpendicular to each other.

[0053] Moreover, in the first direction, the hollow foil portion 12 is close to the outer edge of at least one end of the full tab core. The following describes the cooperation between the coating portion 11 and the hollow foil portion 12 with reference to specific examples.

[0054] For example, the height direction of the pole piece is the up-down direction. Along the up-down direction, the middle outer surface of the pole piece is coated with active material, and the upper and lower outer surfaces of the pole piece are not coated with active material.

[0055] For another example, the middle and lower surfaces of the pole piece are coated with active material, while the upper surface of the pole piece is not coated with active material.

[0056] For another example, the upper middle surface of the pole piece is coated with active material, and the lower surface of the pole piece is not coated with active material.

[0057] That is, the wound full-tab core includes a coated portion 11 and a hollow foil portion 12, wherein the coated portion 11 contains active material and the hollow foil portion 12 does not contain active material. In this embodiment, the hollow foil portion 12 is provided at least at one end of the battery cell 1 in the first direction, i.e., leaving an open space. This greatly improves the electrolyte infiltration efficiency and the discharge rate of gas generated within the battery cell 1, greatly enhancing production efficiency and product safety.

[0058] Moreover, the empty foil portion 12 is connected to the current collector 2. It should be noted that when the active material is coated on the lower middle or upper middle portion of the above-mentioned full tab winding core, the end of the full tab winding core coated with the active material can be connected to an existing current collecting plate, etc., which will not be elaborated here.

[0059] Furthermore, the current collector 2 primarily consists of a body 21 and a raised portion 22. For ease of explanation, one side surface of the body 21 in its thickness direction can be defined as a first surface 211, and the other side surface as a second surface 212. The first surface 211 is close to the battery cell 1, and the second surface 212 is further away from the battery cell 1. In this case, the raised portion 22 protrudes from the first surface 211 and can also be defined as a boss.

[0060] The raised portion 22 of the current collector 2 is connected to the end face of the empty foil portion 12 by laser thermal welding. For example, the first direction is the up-down direction, the height direction of the full tab core extends in the up-down direction, the upper part of the full tab core has an empty foil portion 12, the lower part also has an empty foil portion 12, and the middle part has a coating portion 11. The current collector 2 may include a body 21 extending in the horizontal direction and a raised portion 22 protruding from the surface of the body 21. For the empty foil portion 12 at the upper part of the full tab core, the body 21 is located above the empty foil portion 12, the raised portion 22 extends downward and is connected to the upper end face of the empty foil portion 12 by laser thermal welding. For the empty foil portion 12 at the lower part of the electrode, the body 21 is located below the empty foil portion 12, the raised portion 22 extends upward and is connected to the lower end face of the empty foil portion 12 by laser thermal welding.

[0061] It should be noted that if Figure 6 As shown, in the existing laser penetration welding, when laser welding the current collector 2 and the battery cell 1, it is necessary to focus the laser near the end face of the raised portion 22 of the current collector 2 to melt part of the current collector 2 to connect the hollow foil portion 12 of the battery cell 1 and the end face of the raised portion 22 of the current collector 2. Figure 6 The molten pool a' and the effective welding area b' are shown in FIG. Figure 5 As shown, in this embodiment, the welding method adopts thermal conduction welding, that is, the molten pool caused by welding does not directly penetrate the welding area, but heats and melts the foil in the heat-affected zone of the molten pool to achieve the connection between the protrusion 22 and the hollow foil 121. Figure 5 The molten pool a, effective welding zone b and heat-affected zone c are shown in FIG.

[0062] As can be seen, in this embodiment, the laser welding method using thermal conduction welding achieves a lower laser spot power density than laser penetration welding, making it difficult for the molten pool to penetrate the current collector 2, thus minimizing the possibility of burning the battery cell 1. In this embodiment, the local temperature of the weld area is lower than that of penetration welding, thus minimizing damage to the core.

[0063] Therefore, according to the embodiment of the utility model, the cylindrical battery is mainly composed of a battery cell 1 and a current collector 2. On the one hand, by adopting a full-tab winding core, the connection area between the tab and the current collector 2 can be expanded, thereby improving the flow capacity of the battery cell 1; on the other hand, by providing a hollow foil portion 12 with a height difference and a current collector 2 with a height difference, the connection area and connection tightness between the end face of the hollow foil portion 12 and the end face of the current collector 2 can be increased, that is, the connection area and connection tightness between the end face welding area of ​​the hollow foil portion 12 and the end face of the current collector 2 can be increased, thereby improving the process effect of laser thermal conductivity welding.

[0064] Optionally, the width of the coated area of ​​the negative electrode sheet should be greater than the width of the coated area of ​​the positive electrode sheet. The width here refers to the end size of the electrode sheet in the winding direction, that is, along the winding direction or the length direction of the electrode sheet, the two ends of the negative electrode sheet extend beyond the two ends of the positive electrode sheet. For example, before winding, the positive electrode sheet and the negative electrode sheet both extend in the left-right direction, the left end of the positive electrode sheet is shorter than the left end of the negative electrode sheet, and the right end of the positive electrode sheet is shorter than the right end of the negative electrode sheet. When winding, it is wound from left to right. In this embodiment, by limiting the dimensional relationship between the negative electrode sheet and the positive electrode sheet, it is beneficial to improve safety performance and effectively prevent short circuits.

[0065] Optionally, there are two layers of diaphragms. For ease of explanation, the two layers of diaphragms can be divided into a first diaphragm 13 and a second diaphragm 14. The first diaphragm 13 is located between the positive electrode sheet and the negative electrode sheet, and the negative electrode sheet is located between the first diaphragm 13 and the second diaphragm 14. Along the winding direction or the length direction of the electrode sheet, the two ends of the first diaphragm 13 exceed the two ends of the positive electrode sheet, and the two ends of the second diaphragm 14 exceed the two ends of the negative electrode sheet. For example, before winding, the right end of the first diaphragm 13 exceeds the right end of the positive electrode sheet, the right end of the negative electrode sheet exceeds the right end of the first diaphragm 13, and the second diaphragm 14 exceeds the right end of the negative electrode sheet. When winding, winding is from left to right. In this embodiment, by limiting the dimensional relationship between the positive electrode sheet, the negative electrode sheet and the diaphragm, it is beneficial to improve safety performance and effectively prevent short circuits.

[0066] Optionally, after winding to form a full-tab core, the gap between each two adjacent layers of hollow foil 121 in the second direction is uniform, which is beneficial to improving battery performance.

[0067] Optionally, the current collector 2 is made of metal materials such as nickel, aluminum, nickel-plated aluminum, copper, nickel-plated copper, steel, nickel-plated steel or stainless steel. By using the above materials, the battery performance can be effectively improved.

[0068] According to one embodiment of the present invention, the raised portion 22 includes a first connecting portion 221 and a second connecting portion 222. The first connecting portion 221 is an annular member. Along a first direction, one end of the first connecting portion 221 is connected to the body 21, and the second connecting portion 222 closes the other end of the first connecting portion 221. The second connecting portion 222 cooperates with the first connecting portion 221 to form a groove 223. In this embodiment, by using the first connecting portion 221 and the second connecting portion 222 to cooperate with each other, not only can the raised portion 22 be formed, but the processing of the raised portion 22 is also facilitated, for example, by stamping the unprocessed current collector 2 to form the raised portion 22, and the total weight of the raised portion 22 can also be reduced.

[0069] In some specific embodiments of the present invention, in the first direction, both side surfaces of the second connecting portion 222 are planar, and the thickness of the second connecting portion 222 is 0.1 mm to 0.4 mm. For example, the upper and lower side surfaces of the second connecting portion 222 are both planar, extending horizontally, and the thickness of the second connecting portion 222 is the distance between the upper and lower side surfaces of the second connecting portion 222. In this embodiment, by limiting the thickness of the second connecting portion 222 to 0.1 mm to 0.4 mm, for example, the thickness of the second connecting portion 222 is 0.1 mm, 0.2 mm, 0.3 mm, or 0.4 mm, the requirements of the laser thermal conduction welding process can be met. In addition, before production, if the thickness of the original flat-plate structure of the current collector 2 meets the requirement of being able to produce a second connecting portion 222 with a thickness of 0.1mm-0.4mm, the original thickness of the current collector 2 can be maintained; if the thickness of the second connecting portion 222 obtained by the thickness of the original flat-plate structure of the current collector 2 is greater than 0.1mm-0.4mm, then before processing such as stamping, at least a portion of the thickness of the flat-plate structure of the current collector 2 can be thinned to a thickness that meets the requirements.

[0070] According to one embodiment of the present invention, the current collector 2 is the outer shell or current collecting tray of a cylindrical battery. That is, the current collector 2 can be a separate current collecting tray or the outer shell 4 of a cylindrical battery. When the current collector 2 is part of the outer shell 4 of a cylindrical battery, a raised portion 22 can be formed on a plane of the outer shell 4 of the cylindrical battery during manufacturing. For example, the outer shell 4 of the cylindrical battery extends in the vertical direction, and the outer shell 4 is a cup-shaped member with a receiving space and an open top. The bottom of the outer shell 4 is embossed with an upwardly extending raised portion 22, which protrudes into the interior of the outer shell 4.

[0071] In some specific embodiments of the present invention, a body 21 includes multiple raised portions 22, each of which is spaced apart and distributed around a first direction. Furthermore, the outer contour of each raised portion 22 is a trapezoid or a rectangle, for example. When the outer contour is a trapezoid, the short side of the trapezoid is close to the central axis of the full-tab winding core. When the outer contour is a rectangle, the two ends of the rectangle are straight or semicircular. For example, a body 21 may be formed with four raised portions 22 by downward stamping. The body 21 is disc-shaped, and the four raised portions 22 are spaced apart and evenly and symmetrically distributed around the central axis of the disc. Each raised portion 22 has a trapezoidal cross-section, with the short side being close to the central axis of the disc and the long side being away from the central axis. For another example, the raised portion 22 may have a strip-shaped cross-section, with the two short sides being arc-shaped, and the centers of the arcs being close to the central axis of the strip.

[0072] According to one embodiment of the present invention, the current collector 2 is a single piece. For example, before processing, the current collector 2 is a flat plate with both its upper and lower surfaces extending horizontally. Through downward embossing, one or more downwardly protruding protrusions 22 are formed. In this embodiment, the use of a single piece of current collector 2 not only facilitates processing of the protrusions 22, but also ensures the overall structural strength of the current collector 2.

[0073] In some specific embodiments of the present invention, the hollow foil 121 with a second height includes: a first segment 1211 and a second segment 1212, the first segment 1211 extends along the first direction, the second segment 1212 extends along the second direction, and one end in the second direction is connected to the first segment 1211, and the end surface of the second segment 1212 in the first direction is connected to the surface of the protrusion 22 by laser thermal welding.

[0074] In this embodiment, the hollow foil material 121 having the second height includes a first segment 1211 and a second segment 1212. Specifically, the second segment 1212 can be formed by bending. For example, during assembly, the protrusion 22 is squeezed along the axial direction of the full tab winding core. Figure 2 The extrusion force in the direction of the arrow shown bends the part of the hollow foil 121 into the shape of Figure 3 The second segment 1212 is shown. Moreover, the first segment 1211 extends in the first direction, and the second segment 1212 extends in the second direction after being bent. For example, the first segment 1211 extends in the vertical direction, while the second segment 1212 extends in the horizontal direction. In addition, the surface area of ​​the second segment 1212 after being bent is larger, which is conducive to its contact with the surface of the protrusion 22 and through Figure 4 The solid inverted triangle shown in the figure is used to indicate the laser thermal conduction welding, and the flatness of the surface corresponding to the second segment 1212 and the protrusion 22 formed by bending is better. For example, the upper surface of the second segment 1212 is bonded to the lower surface of the protrusion 22 and connected by laser thermal conduction welding; for another example, the lower surface of the second segment 1212 is bonded to the upper surface of the protrusion 22 and connected by laser thermal conduction welding. It can be understood that by bonding the surface to the surface, it is beneficial to improve the welding effect. In addition, by using the bent hollow foil 121, the connection width between the tab and the current collector 2 can be expanded, thereby improving the flow capacity of the battery cell 1.

[0075] According to one embodiment of the present invention, in the first direction, the raised portion 22 has a height d, and in the second direction, a gap D is formed between two adjacent layers of hollow foil 121, where d>D. In this embodiment, by limiting the height of the raised portion 22 to be greater than the gap between the two adjacent layers of hollow foil 121, laser thermal conduction welding is facilitated.

[0076] Optionally, the cylindrical battery further includes a top cover 3 , the top cover 3 has an opening in the center, a pole is riveted in the center of the opening, and an insulating layer is provided between the pole and the cover, which can improve safety performance.

[0077] The present invention also provides a method for manufacturing a cylindrical battery. The cylindrical battery is any of the cylindrical batteries in the above embodiments. The manufacturing method comprises the following steps:

[0078] Along the first direction, a force is applied to the current collector 2 toward the empty foil portion 12, so that the empty foil material 121 corresponding to the protrusion 22 has a second height after being bent, and the protrusion 22 is attached to the end surface of the empty foil portion 12;

[0079] The hollow foil 121 having the second height is connected to the protrusion 22 by laser heat conduction welding.

[0080] It can be seen that in this embodiment, the existing laser welding connection method is improved, so that the heat input during the welding process is smaller, the damage to the battery cell 1 is less, and the yield rate is improved. Moreover, by applying a force toward the empty foil portion 12 to the current collector 2, a portion of the empty foil portion 12 can be bent, and then the second segment 1212 formed after bending is laser-thermal-welded to the current collector 2, which can increase the welding area and facilitate its full fit with the end face of the raised portion 22, and can meet the welding requirements of thermal-conductive welding. Moreover, by squeezing the current collector 2 to bend the empty foil portion 12, one end of the empty foil portion 12 is locally deformed, which simplifies the tab processing process of the battery cell 1 and greatly improves production efficiency and product quality.

[0081] In addition, when the protrusion 22 is pressed toward the hollow foil portion 12 , a portion of the hollow foil portion 12 corresponding to the protrusion 22 is bent; while another portion of the hollow foil portion 12 corresponding to the body 21 is not bent and can be attached to the surface of the body 21 .

[0082] In this embodiment, by improving the design of the current collector 2 and adapting the laser thermal welding process, the additional processing of the exposed hollow foil portion in the prior art is eliminated, which greatly simplifies the process and avoids the corresponding process risks.

[0083] The present invention also provides an electrical device comprising a cylindrical battery according to any of the aforementioned embodiments, or a cylindrical battery produced by the method for producing a cylindrical battery according to any of the aforementioned embodiments. Because the cylindrical batteries according to the present invention have advantages such as ease of processing and reduced damage to the winding core, electrical devices comprising the cylindrical batteries according to any of the aforementioned embodiments also possess the same advantages, which will not be further elaborated here.

[0084] The cylindrical battery and the manufacturing method thereof according to the present invention are described in detail below with reference to specific embodiments.

[0085] Example

[0086] The cylindrical battery comprises an outer shell 4, a battery cell 1, a current collecting plate and a top cover 3. The upper and lower ends of the battery cell 1 are hollow foil portions 12. In this embodiment, a portion of the outer shell 4 and the current collecting plate are current collectors 2.

[0087] Specifically, the outer shell 4 of the cylindrical battery extends in the up and down directions. The outer shell 4 is a cup-shaped member with a receiving space and an open upper end. Four upward-extending bosses are embossed on the bottom of the outer shell 4. The four bosses are symmetrically distributed with the center of the bottom cover of the outer shell 4 as the center of symmetry.

[0088] The lower end surface of the collecting plate is formed with four bosses by embossing, and the four bosses are evenly and symmetrically distributed with the center of the collecting plate as the symmetry center.

[0089] The assembly process includes the following steps:

[0090] S1. Press the current collecting plate downward into the battery cell 1, and bend a portion of the hollow foil portion 12 at the upper end of the positive electrode sheet to form a second segment 1212 extending in the horizontal direction and a first segment 1211 extending in the vertical direction. The upper end surface of the second segment 1212 is fitted with the lower end surface of the boss at the lower end of the current collecting plate, and the second segment 1212 of the positive electrode sheet and the current collecting plate are connected by laser thermal welding, that is, the positive electrode tab and the current collecting plate are connected.

[0091] S2. Weld the collecting plate and the top cover 3.

[0092] S3. Place the battery cell 2 inside the outer shell 4, press the boss on the bottom surface of the outer shell 4 upward into the lower end of the negative electrode sheet to form the second segment 1212. Connect the second segment 1212 of the negative electrode sheet and the outer shell 4 by laser thermal welding, that is, connect the negative electrode tab and the outer shell 4.

[0093] S4. The top cover 3 and the outer shell 4 are sealed by laser welding to complete the assembly.

[0094] In summary, according to the cylindrical battery and its manufacturing method of the embodiment of the utility model, by providing a hollow foil portion 12 with a height difference and a current collector 2 including a main body 21 and a protruding portion 22, and then adapting the corresponding laser thermal welding process, a full-tab battery design is realized, which can significantly reduce the internal resistance of the battery with lower process difficulty and improve the flow capacity. In addition, the local temperature of the welding area during laser thermal welding is lower than that during penetration welding, so the damage to the core is lower.

[0095] Although some specific embodiments of the present invention have been described in detail through examples, those skilled in the art will appreciate that the above examples are for illustration only and are not intended to limit the scope of the present invention. Those skilled in the art will appreciate that modifications may be made to the above embodiments without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A cylindrical battery, characterized in that: include: A battery cell (1), wherein the battery cell (1) is a full-tab core with a central axis extending along a first direction, the full-tab core comprising a coated portion (11) coated with an active material and a hollow foil portion (12) not coated with the active material, the hollow foil portion (12) being close to an outer edge of one end of the full-tab core in the first direction, the hollow foil portion (12) comprising a plurality of hollow foils (121) adjacently arranged in a second direction, the second direction being non-parallel to the first direction, a portion of the hollow foils (121) having a first height in the first direction, another portion of the hollow foils (121) having a second height, the first height being greater than the second height; A current collector (2), the current collector (2) comprising a body (21) and a raised portion (22), the raised portion (22) protruding from a side surface of the body (21); The hollow foil material (121) having the first height is connected to the body (21), and the hollow foil material (121) having the second height is connected to the raised portion (22) by laser thermal welding.

2. The cylindrical battery according to claim 1, characterized in that The raised portion (22) comprises: A first connecting portion (221) and a second connecting portion (222), wherein the first connecting portion (221) is an annular member, and along the first direction, one end of the first connecting portion (221) is connected to the body (21), and the second connecting portion (222) closes the other end of the first connecting portion (221), and the second connecting portion (222) and the first connecting portion (221) cooperate to form a groove (223).

3. The cylindrical battery according to claim 2, characterized in that In the first direction, both side surfaces of the second connecting portion (222) are planes, and the thickness of the second connecting portion (222) is 0.1 mm-0.4 mm.

4. The cylindrical battery according to claim 1, wherein: The current collector (2) is the outer shell or current collecting disk of the cylindrical battery.

5. The cylindrical battery according to claim 1, characterized in that There are multiple protrusions (22) on one body (21), and the multiple protrusions (22) are spaced apart and distributed around the first direction; and / or the outer contour of the protrusion (22) is a trapezoid or a rectangle, and when the outer contour is a trapezoid, the short side of the trapezoid is close to the central axis of the full-tab winding core, and when the outer contour is a rectangle, the two ends of the rectangle are straight sides or semicircular sides.

6. The cylindrical battery according to any one of claims 1 to 5, characterized in that: The current collector (2) is an integral piece.

7. The cylindrical battery according to claim 1, characterized in that The hollow foil (121) having the second height comprises: a first segment (1211), the first segment (1211) extending along the first direction; A second segment (1212) extends along the second direction, and one end of the second segment (1212) is connected to the first segment (1211), and an end surface of the second segment (1212) in the first direction is connected to the surface of the raised portion (22) by laser thermal welding.

8. The cylindrical battery according to claim 1, wherein: In the first direction, the protrusion (22) has a height d, and in the second direction, there is a gap D between two adjacent layers of the hollow foil (121), where d>D.

9. An electrical device, characterized in that: The cylindrical battery comprises the cylindrical battery described in any one of claims 1 to 8.

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