Cylindrical battery and manufacturing method therefor, and electrical device

Abstract

A manufacturing method for a cylindrical battery, a cylindrical battery manufactured by means of the manufacturing method, and an electrical device comprising the cylindrical battery. The cylindrical battery comprises a battery cell and a current collector. The battery cell is a full-tab jelly roll, and the battery cell comprises a coating portion and a bare foil portion. The bare foil portion is close to an outer edge of one end of the full-tab jelly roll in a first direction, and the bare foil portion comprises a plurality of bare foil sheets arranged adjacently in a second direction, some of the bare foil sheets having a first height, and some of the bare foil sheets having a second height. The current collector comprises a body and a protruding portion, the bare foil sheets having the first height being connected to the body, and the bare foil sheets having the second height being connected to the protruding portion by means of laser heat conduction welding.

Description

Cylindrical battery, manufacturing method thereof and electric device

[0001] The present disclosure claims priority to the Chinese patent application No. 2024111052427, filed on August 13, 2024, and entitled "Cylindrical battery, manufacturing method thereof and electric device", the entire content of which is incorporated herein by reference. TECHNICAL FIELD

[0002] The present disclosure relates to the technical field of battery, and more particularly, to a cylindrical battery, a manufacturing method thereof and an electric device. BACKGROUND

[0003] In the related art, the following scheme is proposed to improve the overcurrent capacity of the cylindrical battery cell:

[0004] (1) Multi-tab scheme: increase the number of tabs to improve the overcurrent capacity of the battery cell. Since the process difficulty increases significantly with the increase in the number of tabs, this scheme cannot meet the demand for high-rate charging and discharging.

[0005] (2) Rubbing tab scheme: leaving positive and negative empty foils at both ends of the winding core, the empty foil area is compressed into a solid by physical processing, and then a current collecting disc is welded on the compressed empty foil area to lead out the electrical connection. The problem of this scheme is that metal particles may be generated when the empty foil area is compressed, which is easy to cause internal short circuit of the battery and produce safety risk.

[0006] (3) Cutting and stacking tab (full tab) scheme: cutting the empty foil material at the end face of the winding core into strips perpendicular to the winding direction, folding and stacking the cut empty foil area in the winding and compacting, and then welding a current collecting disc to lead out the electrical connection. The problem of this scheme is that the process difficulty of cutting the tabs is large, and the efficiency and yield are difficult to guarantee; the flatness of the compacted empty foil area is poor, which limits the subsequent current collecting disc welding process.

[0007] In addition, the above schemes usually use laser penetration welding to connect the tabs and the current collecting disc, the temperature of the welding area is high, the damage to the winding core is also large, and the yield of the finally prepared product is low. SUMMARY

[0008] One purpose of the present disclosure is to provide a cylindrical battery, which at least solves the technical problem in the prior art that the laser penetration welding is used to connect the tabs and the current collecting disc, the temperature of the welding area is high, the damage to the winding core is also large, and the yield of the finally prepared product is low.

[0009] Another purpose of the present disclosure is to provide a manufacturing method of a cylindrical battery, which is used to manufacture the above cylindrical battery.

[0010] Still another object of the present disclosure is to provide an electric device comprising the cylindrical battery.

[0011] To achieve the above object, the present disclosure provides the following technical solutions.

[0012] The cylindrical battery according to the first aspect of the present disclosure comprises: an electric core, the electric core being a full-tab roll core with a central axis extending in a first direction, the full-tab roll core comprising a coated part coated with an active material and an empty foil part without the active material, the empty foil part being close to an outer edge of one end of the full-tab roll core in the first direction, the empty foil part comprising a plurality of empty foil materials arranged adjacent in a second direction, the second direction being arranged non-parallel to the first direction, in the first direction, a part of the empty foil materials has a first height, and another part of the empty foil materials has a second height, the first height being greater than the second height; a current collector, the current collector comprising a body and a protruding part protruding from one side surface of the body; wherein the empty foil material with the first height is connected with the body, and the empty foil material with the second height is connected with the protruding part by laser heat conduction welding.

[0013] Optionally, the protruding part comprises: a first connecting part and a second connecting part, the first connecting part being a ring-shaped part, in the first direction, one end of the first connecting part being connected with the body, and the second connecting part enclosing the other end of the first connecting part, the second connecting part and the first connecting part cooperating to form a groove.

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

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

[0016] Optionally, the number of the protruding parts on one body is a plurality, and the plurality of protruding parts are distributed at intervals around the first direction; and / or, the outer contour of the protruding part is trapezoidal or rectangular, when the outer contour is trapezoidal, the short side of the trapezoid is close to the central axis of the full-tab roll core, and when the outer contour is rectangular, the two ends of the rectangle are straight sides or semicircular sides.

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

[0018] Optionally, the empty foil material with the second height comprises: a first segment extending in the first direction; and a second segment extending in the second direction, one end of the second segment in the second direction being connected with the first segment, and the end surface of the second segment in the first direction being connected with the surface of the protruding part by laser heat conduction welding.

[0019] Optionally, in the first direction, the protruding portion has a height d, and in the second direction, a gap D exists between two adjacent layers of the hollow foil, d>D.

[0020] The manufacturing method of the cylindrical battery according to the second aspect of the present disclosure, the cylindrical battery being any of the cylindrical batteries described above, comprises the following steps: applying a force towards the hollow foil portion to the current collector along a first direction, so that the hollow foil corresponding to the protruding portion has a second height after being bent, and the end surface of the protruding portion is attached to the end surface of the hollow foil portion; and connecting the hollow foil with the second height and the protruding portion by laser heat conduction welding.

[0021] The electrical device according to the third aspect of the present disclosure comprises any of the cylindrical batteries described above, or is prepared by the manufacturing method of any of the cylindrical batteries described above.

[0022] The cylindrical battery according to the embodiments of the present disclosure mainly comprises an electric core and a current collector. On the one hand, by adopting a full-tab winding core, the connection area of the tab and the current collector can be expanded, so that the overcurrent capacity of the electric core can be improved. On the other hand, by setting the hollow foil portion with a height difference and the current collector with a height difference, the connection area and the connection tightness between the end surface of the hollow foil portion and the end surface of the current collector can be increased, that is, the connection area and the connection tightness of the end surface welding area of the hollow foil portion and the end surface of the current collector can be increased, so that the process effect of laser heat conduction welding can be improved.

[0023] Other features of the present disclosure and its advantages will become apparent from the following detailed description of exemplary embodiments of the present disclosure with reference to the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0024] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0025] FIG. 1 is a winding schematic diagram of an electric core of a cylindrical battery according to an embodiment of the present disclosure;

[0026] FIG. 2 is a mounting schematic diagram of a current collector and a hollow foil portion according to an embodiment of the present disclosure;

[0027] FIG. 3 is a schematic diagram of a current collector extruding a hollow foil according to an embodiment of the present disclosure;

[0028] FIG. 4 is a schematic diagram of a current collector and a hollow foil portion connected by laser heat conduction welding according to an embodiment of the present disclosure;

[0029] FIG. 5 is a process diagram of a current collector and an empty foil portion connected by laser heat conduction welding according to one embodiment of the present disclosure;

[0030] FIG. 6 is a process diagram of laser penetration welding of the prior art;

[0031] FIG. 7 is a structure diagram of one angle of a cylindrical battery according to one embodiment of the present disclosure;

[0032] FIG. 8 is a structure diagram of another angle of a cylindrical battery according to one embodiment of the present disclosure;

[0033] FIG. 9 is a partial exploded view of a cylindrical battery according to one embodiment of the present disclosure;

[0034] FIG. 10 is a vertical sectional view of a cylindrical battery according to one embodiment of the present disclosure.

[0035] FIG. 10 is a vertical sectional view of a cylindrical battery according to one embodiment of the present disclosure. DETAILED DESCRIPTION

[0036] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. If need arises, the relative arrangement, numerical expressions, and numerical values of components and steps set forth in these embodiments are not limiting the scope of the present disclosure.

[0037] The following description of at least one exemplary embodiment is merely exemplary in nature and is in no way intended to limit the scope of the present disclosure, its application, or uses.

[0038] Techniques, methods, and apparatus known to those of ordinary skill in the relevant art can not be discussed in detail herein. However, where appropriate, such techniques, methods, and apparatus can be considered part of the present disclosure.

[0039] In all of the examples shown and discussed herein, any specific values should be interpreted as merely exemplary and not limiting. Thus, other examples of the exemplary embodiments can have different values.

[0040] It should be noted that like reference numerals and letters in the various figures indicate similar items, and thus, once an item is defined in one figure, it is not necessary to discuss it further in subsequent figures.

[0041] A cylindrical battery according to an embodiment of the present disclosure is described in detail below with reference to the accompanying drawings.

[0042] As shown in FIGS. 1-5 and 7-10, a cylindrical battery according to an embodiment of the present disclosure includes an electrode core 1 and a current collector 2.

[0043] Specifically, the electrode core 1 is a full tab jelly-roll with a central axis extending in a first direction, the full tab jelly-roll includes a coated portion 11 coated with an active material and an empty foil portion 12 not coated with the active material, the empty foil portion 12 is adjacent to an outer edge of one end of the full tab jelly-roll in the first direction, the empty foil portion 12 includes a plurality of empty foil materials 121 arranged adjacent to each other in a second direction, the second direction is arranged non-parallel to the first direction, in the first direction, a portion of the empty foil materials 121 has a first height H1, and another portion of the empty foil materials 121 has a second height H2, the first height H1 is greater than the second height H2. The current collector 2 includes a body 21 and a protruding portion 22 protruding from one side surface of the body 21. Among them, the empty foil material 121 with the first height H1 is connected with the body 21, and the empty foil material 121 with the second height H2 is connected with the protruding portion 22 by laser heat conduction welding.

[0044] In other words, the cylindrical battery according to an embodiment of the present disclosure mainly consists of the electrode core 1 and the current collector 2, wherein the electrode core 1 is a full tab jelly-roll, the full tab jelly-roll can be prepared by winding, for example, a plurality of layers of electrode sheets formed by winding in the direction indicated by the arrow in FIG. 1, wherein the electrode sheets can be positive electrode sheets or negative electrode sheets, and a separator is arranged between the positive electrode sheets and the negative electrode sheets, which can effectively prevent the occurrence of positive and negative short circuits. When making the full tab jelly-roll, the positive electrode sheets, the separator and the negative electrode sheets can be stacked and then wound to form the full tab jelly-roll.

[0045] It can be understood that along the axial direction of the full tab jelly-roll, i.e. the first direction, the full tab jelly-roll includes the coated portion 11 and the empty foil portion 12 arranged adjacent to each other. The empty foil portion 12 of the positive electrode can serve as a positive electrode tab, and the empty foil portion 12 of the negative electrode can serve as a negative electrode tab. Moreover, each layer of electrode sheets includes the coated portion 11 and the empty foil portion 12 arranged adjacent to each other. Among them, the surface of the coated portion 11 is coated with an active material, and the surface of the empty foil portion 12 is not coated with an active material. For example, the flattened positive electrode sheets and negative electrode sheets can be respectively provided with the empty foil portions 12 not coated with positive and negative active materials at both side ends in the first direction. In addition, during coating, continuous coating can be adopted for both the positive electrode sheets and the negative electrode sheets, i.e. no gap is arranged in the winding direction.

[0046] Moreover, the plurality of hollow foils 121 are wound in the second direction to form the plurality of layers of the hollow foil portion 12. In this case, the axial direction of the full-tab winding core can be the first direction, the winding direction can be the second direction, and the first direction and the second direction are non-parallel, i.e., have an included angle therebetween, for example, the first direction and the second direction are perpendicular to each other.

[0047] Moreover, in the first direction, the hollow foil portion 12 is adjacent to the outer edge of at least one end of the full-tab winding core. The cooperation between the coating portion 11 and the hollow foil portion 12 is described below with reference to specific examples.

[0048] For example, the height direction of the pole piece is the up-down direction, and in the up-down direction, the outer surface of the middle part of the pole piece is coated with the active material, and the outer surfaces of the upper part and the lower part of the pole piece are not coated with the active material.

[0049] For another example, the outer surface of the middle and lower part of the pole piece is coated with the active material, and the outer surface of the upper part of the pole piece is not coated with the active material.

[0050] For another example, the outer surface of the middle and lower part of the pole piece is coated with the active material, and the outer surface of the upper part of the pole piece is not coated with the active material.

[0051] That is, the full-tab winding core formed by winding includes the coating portion 11 and the hollow foil portion 12, wherein the coating portion 11 has the active material, and the hollow foil portion 12 does not have the active material. In this embodiment, the hollow foil portion 12 is arranged at at least one end of the battery cell 1 in the first direction, i.e., an open space is left, which greatly improves the electrolyte infiltration efficiency and the discharge speed of the gas generated inside the battery cell 1, and greatly improves the production efficiency and product safety.

[0052] Moreover, the hollow foil portion 12 is connected to the current collector 2. It should be noted that when the active material is coated on the middle and lower part or the middle and upper part of the full-tab winding core as described above, the end of the full-tab winding core coated with the active material can be connected to the existing current collecting disc, etc., which is not described here.

[0053] In addition, the current collector 2 mainly consists of a body 21 and a protruding portion 22. For ease of description, one side of the body 21 in the thickness direction of the body 21 can be defined as a first surface 211, and the other side can be defined as a second surface 212, the first surface 211 is close to the battery cell 1, and the second surface 212 is away from the battery cell 1. At this time, the protruding portion 22 protrudes from the first surface 211, and the protruding portion 22 can also be defined as a boss.

[0054] The protruding portion 22 of the current collector 2 is connected to the end face of the empty foil portion 12 by laser heat conduction welding. For example, the first direction is the up-down direction, the height direction of the full-tab jelly-roll extends along the up-down direction, the upper part of the full-tab jelly-roll has the empty foil portion 12, the lower part also has the empty foil portion 12, and the middle part has the coated portion 11. The current collector 2 can include a body 21 extending along the horizontal direction and a protruding portion 22 protruding from the surface of the body 21. For the empty foil portion 12 of the upper part of the full-tab jelly-roll, the body 21 is located above the empty foil portion 12, and the protruding portion 22 extends downward and is connected to the upper end face of the empty foil portion 12 by laser heat conduction welding. For the empty foil portion 12 of the lower part of the tab, the body 21 is located below the empty foil portion 12, and the protruding portion 22 extends upward and is connected to the lower end face of the empty foil portion 12 by laser heat conduction welding.

[0055] It should be noted that, as shown in FIG. 6, in the existing laser penetration welding, when welding the current collector 2 and the battery cell 1, the laser needs to be focused near the end face of the protruding portion 22 of the current collector 2 to melt part of the current collector 2 to connect the empty foil portion 12 of the battery cell 1 and the end face of the protruding portion 22 of the current collector 2. The molten pool a' and the effective welding area b' are shown in FIG. 6. As shown in FIG. 5, in the present embodiment, the welding method adopts heat conduction welding, that is, the molten pool caused by welding does not directly penetrate the welding area, but the connection between the protruding portion 22 and the empty foil 121 is achieved by heating and melting the foil through the heat affected zone of the molten pool. The molten pool a, the effective welding area b, and the heat affected zone c are shown in FIG. 5.

[0056] It can be seen that, in the present embodiment, by adopting the laser welding method of heat conduction welding, the laser spot power density is smaller than that of laser penetration welding, the molten pool is not easy to penetrate the current collector 2, and the possibility of burning the battery cell 1 is smaller. In the present embodiment, by adopting heat conduction welding, the local temperature of the welding area during heat conduction welding is lower than that during penetration welding, and therefore the damage to the jelly-roll is lower.

[0057] Therefore, the cylindrical battery according to the embodiment of the present disclosure is mainly composed of the battery cell 1 and the current collector 2. On the one hand, by adopting the full-tab jelly-roll, the connection area of the tab and the current collector 2 can be expanded, so that the overcurrent capacity of the battery cell 1 can be improved. On the other hand, by providing the empty foil portion 12 with a height difference and the current collector 2 with a height difference, the connection area and the connection tightness between the end face of the empty foil portion 12 and the end face of the current collector 2 can be increased, that is, the connection area and the connection tightness of the end face welding area of the empty foil portion 12 and the end face of the current collector 2 can be increased, so that the process effect of laser heat conduction welding can be improved.

[0058] Optionally, the width of the coated area of the negative electrode sheet is greater than the width of the coated area of the positive electrode sheet, where the width refers to the end size of the electrode sheet in the winding direction, i.e. along the winding direction or the length direction of the electrode sheet, and 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, the right end of the positive electrode sheet is shorter than the right end of the negative electrode sheet, and winding is performed from left to right. In this embodiment, by limiting the size relationship of the negative electrode sheet and the positive electrode sheet, the safety performance is improved, and short circuit is effectively prevented.

[0059] Optionally, the number of separators is two, and for ease of description, the two separators can be distinguished as a first separator 13 and a second separator 14, the first separator 13 is located between the positive electrode sheet and the negative electrode sheet, and the negative electrode sheet is located between the first separator 13 and the second separator 14. Along the winding direction or the length direction of the electrode sheet, the two ends of the first separator 13 extend beyond the two ends of the positive electrode sheet, and the two ends of the second separator 14 extend beyond the two ends of the negative electrode sheet. For example, before winding, the right end of the first separator 13 extends beyond the right end of the positive electrode sheet, the right end of the negative electrode sheet extends beyond the right end of the first separator 13, and the second separator 14 extends beyond the right end of the negative electrode sheet, and winding is performed from left to right. In this embodiment, by limiting the size relationship of the positive electrode sheet, the negative electrode sheet and the separator, the safety performance is improved, and short circuit is effectively prevented.

[0060] Optionally, after winding to form a full-tab roll core, the gap between each adjacent two layers of empty foils 121 in the second direction is uniform, which is beneficial to improve the performance of the battery.

[0061] 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, etc. By using the above-mentioned materials, the performance of the battery can be effectively improved.

[0062] According to one embodiment of the present disclosure, the protruding part 22 comprises a first connecting part 221 and a second connecting part 222. The first connecting part 221 is a ring-shaped part, one end of the first connecting part 221 is connected to the body 21 in the first direction, the second connecting part 222 closes the other end of the first connecting part 221, and the second connecting part 222 and the first connecting part 221 cooperate to form a groove 223. In this embodiment, by using the first connecting part 221 and the second connecting part 222 to cooperate with each other, not only can the protruding part 22 be formed, but also the protruding part 22 can be easily processed, for example, the unprocessed current collector 2 is pressed to form the protruding part 22, and the total weight of the protruding part 22 can be reduced.

[0063] In some embodiments of the present disclosure, in the first direction, both sides of the second connecting portion 222 are planar, and the thickness of the second connecting portion 222 is 0.1 mm-0.4 mm. For example, the upper side and the lower side of the second connecting portion 222 are both planar surfaces extending in the horizontal direction, and the thickness of the second connecting portion 222 is the distance between the upper side and the lower side of the second connecting portion 222. In the present embodiment, by limiting the thickness of the second connecting portion 222 to 0.1 mm-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, etc., the requirements of the laser heat conduction welding process can be met. In addition, before processing, 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 0.1 mm-0.4 mm, the original thickness of the current collector 2 can be maintained; if the thickness of the original flat-plate structure of the current collector 2 is used to produce a second connecting portion 222 with a thickness greater than 0.1 mm-0.4 mm, at least a portion of the flat-plate structure of the current collector 2 can be thinned to a required thickness before coining or other processing.

[0064] According to one embodiment of the present disclosure, the current collector 2 is an outer shell or a current collector disc of a cylindrical battery. That is, the current collector 2 can be a separate current collector disc or an outer shell 4 of a cylindrical battery. When the current collector 2 is part of the outer shell 4 of a cylindrical battery, the protruding portion 22 can be produced on one plane of the outer shell 4 of the cylindrical battery during production. For example, the outer shell 4 of the cylindrical battery extends in the up-down direction, and the outer shell 4 is a cup-shaped member with a receiving space and an open upper end. A protruding portion 22 extending upward is coined on the bottom of the outer shell 4, that is, protruding into the interior of the outer shell 4.

[0065] In some embodiments of the present disclosure, the number of protruding portions 22 on one body 21 is multiple, and the multiple protruding portions 22 are distributed at intervals around the first direction; and / or the outer contour of the protruding portion 22 is trapezoidal or rectangular, etc. When the outer contour is trapezoidal, the short side of the trapezoid is close to the central axis of the full-tab jelly roll, and when the outer contour is rectangular, the two ends of the rectangle are straight sides or semicircular sides. For example, four protruding portions 22 are formed on one body 21 by downward coining, the body 21 is disc-shaped, the four protruding portions 22 are distributed at intervals around the central axis of the disc-shaped member and are uniformly and symmetrically distributed, the cross section of each protruding portion 22 is trapezoidal, the short side can be close to the central axis of the disc-shaped member, and the long side can be away from the central axis of the disc-shaped member. For another example, the cross section of the protruding portion 22 is long strip-shaped, the two short sides are respectively circular arcs, and the centers of the circular arcs are close to the central axis of the long strip.

[0066] According to one embodiment of the present disclosure, the current collector 2 is an integral piece. For example, before being processed, the current collector 2 is a flat piece with the upper surface and the lower surface extending in the horizontal direction, and one or more protruding portions 22 are formed by downward stamping. In this embodiment, by using the integral current collector 2, not only is it convenient to process the protruding portions 22, but also the overall structural strength of the current collector 2 can be ensured.

[0067] In some specific embodiments of the present disclosure, the hollow foil 121 with the second height includes a first segment 1211 extending in the first direction and a second segment 1212 extending in the second direction and connected to the first segment 1211 at one end in the second direction, and the end surface of the second segment 1212 in the first direction is connected to the surface of the protruding portion 22 by laser heat conduction welding.

[0068] In this embodiment, the hollow foil 121 with the second height includes the first segment 1211 and the second segment 1212, and the second segment 1212 can be formed by bending, for example, during assembly, the protruding portion 22 is pressed along the axial direction of the full-tab jelly roll, and the hollow foil 121 is bent by the pressing force in the direction of the arrow shown in FIG. 2 to form the second segment 1212 shown in FIG. 3. 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, and the second segment 1212 extends in the horizontal direction. In addition, the surface area of the bent second segment 1212 is large, which is conducive to the surface of the protruding portion 22 and the laser heat conduction welding by the laser shown in FIG. 4, and the flatness of the corresponding surface of the bent second segment 1212 and the protruding portion 22 is better. For example, the upper surface of the second segment 1212 is connected to the lower surface of the protruding portion 22 by laser heat conduction welding; for another example, the lower surface of the second segment 1212 is connected to the upper surface of the protruding portion 22 by laser heat conduction welding. It can be understood that the surface-to-surface connection is conducive to improving the welding effect. In addition, by using the bent hollow foil 121, the connection width of the tab and the current collector 2 can be expanded, thereby improving the overcurrent capacity of the battery cell 1.

[0069] According to one embodiment of the present disclosure, in the first direction, the protruding portion 22 has a height d, and in the second direction, the gap D between the adjacent two layers of hollow foils 121, d>D. In this embodiment, by limiting the height of the protruding portion 22 to be greater than the distance between the adjacent two layers of hollow foils 121, it is conducive to the implementation of laser heat conduction welding.

[0070] Optionally, the cylindrical battery further includes a top cover 3 with an opening in the center, and a pole is riveted in the center of the opening, and an insulating layer is arranged between the pole and the cover body, which can improve the safety performance.

[0071] The present disclosure also provides a manufacturing method of a cylindrical battery, the cylindrical battery being any of the cylindrical batteries described above, the manufacturing method comprising the following steps:

[0072] applying a force to the current collector 2 along the first direction towards the hollow foil portion 12, so that the hollow foil 121 corresponding to the protruding portion 22 is bent to have a second height, and the protruding portion 22 is attached to the end surface of the hollow foil portion 12;

[0073] connecting the hollow foil 121 having the second height and the protruding portion 22 by laser heat conduction welding.

[0074] It can be seen that, in the present embodiment, the existing laser welding connection method is improved, so that the heat input of the welding process is smaller, the damage to the battery cell 1 is less, and the yield is improved. Moreover, by applying a force to the current collector 2 towards the hollow foil portion 12, part of the hollow foil portion 12 is bent, and then laser heat conduction welding is performed between the second segment 1212 formed after bending and the current collector 2, which can increase the welding area and facilitate the full attachment of the end surface of the protruding portion 22, so as to meet the welding requirements of heat conduction welding. Moreover, by bending the hollow foil portion 12 by extruding the current collector 2, the end of the hollow foil portion 12 is locally deformed, which simplifies the tab processing process of the battery cell 1 and greatly improves the production efficiency and product quality.

[0075] In addition, when the protruding portion 22 is extruded towards the hollow foil portion 12, part of the hollow foil portion 12 corresponding to the protruding portion 22 is bent, while another part 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.

[0076] In the present embodiment, by improving the design of the current collector 2 and adapting the laser heat conduction welding process, the additional processing of the exposed hollow foil portion in the prior art is cancelled, greatly simplifying the process and avoiding the corresponding process risks.

[0077] The present disclosure also provides an electric device comprising the cylindrical battery of any of the above embodiments, or comprising the cylindrical battery prepared by the manufacturing method of the cylindrical battery of any of the above embodiments. Since the cylindrical battery of the present disclosure has the advantages of being easy to process and reducing damage to the winding core, the electric device comprising the cylindrical battery of any of the above embodiments also has the same advantages, which will not be repeated here.

[0078] The cylindrical battery and the manufacturing method thereof according to the present disclosure will be described in detail below in conjunction with specific embodiments.

[0079] Embodiment

[0080] The cylindrical battery comprises an outer shell 4, an electrode core 1, a current collector plate and a top cover 3, and the upper end and the lower end of the electrode core 1 are both empty foil parts 12. In the embodiment, a part of the outer shell 4 and the current collector plate are both current collectors 2.

[0081] Specifically, the outer shell 4 of the cylindrical battery extends in the up-down direction, and the outer shell 4 is a cup-shaped part with a receiving space and an open upper end. Four bosses extending upward are stamped on the bottom of the outer shell 4, and the four bosses are symmetrically distributed with the center of the bottom cover of the outer shell 4 as the center of symmetry.

[0082] The lower end surface of the current collector plate is formed with four bosses by stamping, and the four bosses are symmetrically distributed with the center of the current collector plate as the center of symmetry.

[0083] In the assembly, the following steps are included:

[0084] S1, press the current collector plate into the electrode core 1 downward, and bend a part of the upper end of the positive tab, forming 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 in contact with the lower end surface of the boss of the lower end of the current collector plate, and the second segment 1212 of the positive tab and the current collector plate are connected by laser heat conduction welding, that is, the positive lug and the current collector plate are connected.

[0085] S2, weld the current collector plate and the top cover 3.

[0086] S3, place the electrode core 2 inside the outer shell 4, press the bosses on the bottom surface of the outer shell 4 into the lower end of the negative tab upward, also forming a second segment 1212, and connect the second segment 1212 of the negative tab and the outer shell 4 by laser heat conduction welding, that is, connect the negative lug and the outer shell 4.

[0087] S4, seal between the top cover 3 and the outer shell 4 by laser welding, and complete the assembly.

[0088] In summary, according to the cylindrical battery and the manufacturing method thereof according to the embodiment of the present disclosure, by setting the empty foil part 12 with height difference and the current collector 2 including the body 21 and the protruding part 22, and then adapting the corresponding laser heat conduction welding process, the full lug battery design is realized, which can significantly reduce the battery internal resistance under the condition of lower process difficulty, and also improve the overcurrent capacity. Moreover, the local temperature of the welding area during laser heat conduction welding is lower than that during penetration welding, so the damage to the winding core is lower.

[0089] While certain embodiments of the disclosure have been described by way of example with specific reference to the drawings, it will be appreciated that the examples are given for purposes of illustration only and are not intended to limit the scope of the disclosure. Those skilled in the art will appreciate that modifications can be made to the described embodiments without departing from the scope and spirit of the disclosure. The scope of the disclosure is defined by the appended claims.

Claims

1. A cylindrical battery, characterized by comprising: The application relates to a cylindrical battery, which comprises: an electric core (1), which is a full-tab roll core with a central axis extending in a first direction, the full-tab roll core comprising a coated part (11) coated with active material and an empty-foil part (12) not coated with active material, the empty-foil part (12) being close to an outer edge of the full-tab roll core at one end in the first direction, the empty-foil part (12) comprising a plurality of empty-foil pieces (121) arranged adjacent to each other in a second direction, the second direction being arranged non-parallel to the first direction, in the first direction, a part of the empty-foil pieces (121) having a first height, and another part of the empty-foil pieces (121) having a second height, the first height being greater than the second height; and a current collector (2), which comprises a body (21) and a protruding part (22) protruding from a side surface of the body (21); wherein the empty-foil pieces (121) having the first height are connected to the body (21), and the empty-foil pieces (121) having the second height are connected to the protruding part (22) by laser heat conduction welding. The protruding part (22) comprises:

2. The cylindrical battery according to claim 1, characterized by a first connecting part (221) and a second connecting part (222), the first connecting part (221) being a ring-shaped piece, one end of the first connecting part (221) being connected to the body (21) in the first direction, the second connecting part (222) closing the other end of the first connecting part (221), and the second connecting part (222) and the first connecting part (221) cooperating to form a groove (223). In the first direction, both side surfaces of the second connecting part (222) are flat surfaces, and the thickness of the second connecting part (222) is 0.1 mm-0.4 mm.

3. The cylindrical battery according to claim 1 or 2, characterized by The current collector (2) is an outer shell or a current collecting disc of the cylindrical battery.

4. The cylindrical battery according to any one of claims 1 to 3, characterized by, The number of the protruding parts (22) on one body (21) is a plurality, and the plurality of protruding parts (22) are distributed at intervals in the first direction; and / or the outer contour of the protruding part (22) is trapezoidal or rectangular, when the outer contour is trapezoidal, the short side of the trapezoid is close to the central axis of the full-tab roll core, and when the outer contour is rectangular, the two ends of the rectangle are straight edges or semicircular edges.

5. The cylindrical battery according to any one of claims 1 to 4, wherein The current collector (2) is an integral piece.

6. The cylindrical battery according to any one of claims 1 to 5, wherein The empty-foil piece (121) having the second height comprises:

7. The cylindrical battery according to any one of claims 1 to 6, wherein a first segment (1211) extending in the first direction; and a second segment (1212) extending in the second direction and connected to the first segment (1211) at one end in the second direction, and the end surface of the second segment (1212) in the first direction being connected to the surface of the protruding part (22) by laser heat conduction welding. In the first direction, the protruding part (22) has a height d, and in the second direction, the gap D between two adjacent layers of the empty-foil pieces (121) is less than d.

8. The cylindrical battery according to any one of claims 1 to 7, wherein ​ 9. A method of manufacturing a cylindrical battery, characterized by, The cylindrical battery is the cylindrical battery according to any one of claims 1-8, and the manufacturing method comprises the following steps: In the first direction, the current collector (2) is applied to the action force towards the empty foil part (12), so that the empty foil (121) corresponding to the convex part (22) has a second height after bending, and the convex part (22) is attached to the end face of the empty foil part (12); The empty foil (121) with the second height is connected with the convex part (22) by laser heat conduction welding.

10. An electric device, characterized by The cylindrical battery comprises the cylindrical battery according to any one of claims 1-8, or the cylindrical battery prepared by the manufacturing method of the cylindrical battery according to claim 9.

Images