CN114976510A - Welding method and welding structure of battery tab and pole - Google Patents
Welding method and welding structure of battery tab and pole Download PDFInfo
- Publication number
- CN114976510A CN114976510A CN202210664916.1A CN202210664916A CN114976510A CN 114976510 A CN114976510 A CN 114976510A CN 202210664916 A CN202210664916 A CN 202210664916A CN 114976510 A CN114976510 A CN 114976510A
- Authority
- CN
- China
- Prior art keywords
- welding
- pass
- tab
- pole
- battery
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/50—Current conducting connections for cells or batteries
- H01M50/528—Fixed electrical connections, i.e. not intended for disconnection
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/50—Current conducting connections for cells or batteries
- H01M50/502—Interconnectors for connecting terminals of adjacent batteries; Interconnectors for connecting cells outside a battery casing
- H01M50/514—Methods for interconnecting adjacent batteries or cells
- H01M50/516—Methods for interconnecting adjacent batteries or cells by welding, soldering or brazing
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/50—Current conducting connections for cells or batteries
- H01M50/531—Electrode connections inside a battery casing
- H01M50/538—Connection of several leads or tabs of wound or folded electrode stacks
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/50—Current conducting connections for cells or batteries
- H01M50/531—Electrode connections inside a battery casing
- H01M50/54—Connection of several leads or tabs of plate-like electrode stacks, e.g. electrode pole straps or bridges
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Abstract
The invention provides a welding method and a welding structure of a battery tab and a battery pole. Meanwhile, a series of welding parameters suitable for welding the pole and the tab are determined, wherein the welding parameters comprise welding laser energy, blowing speed, welding speed, defocusing amount and the like, so that a better welding effect is achieved. The welding method can greatly reduce the generation of crack faults at the welding position of the tab and the pole, and the welding position has a smooth surface and has no defects of air holes, cracks and the like, so that the welding strength is improved, the internal resistance is reduced, the stability of the battery is improved, and the service life of the battery is prolonged.
Description
Technical Field
The invention relates to the technical field of battery electrode welding, in particular to a method for welding a battery tab and a battery pole.
Background
Batteries are a power source for power tools, and have the advantages of long service life, high safety, large capacity, small size, light weight, etc., and are widely used in various fields. As one of new energy sources, lithium ion batteries are widely used in our lives, and aluminum-shell batteries are one of the most widely used battery types in lithium ion batteries because of their safety advantages.
The existing aluminum-shell battery is directly welded with the pole after the pole lug is welded by ultrasonic waves in the manufacturing process, the material cost of a connecting sheet is saved, meanwhile, the structure is simple, the space in the aluminum shell can be fully utilized, the battery capacity is improved, and the manufacturing process difficulty is reduced. However, compared with the traditional ultrasonic welding of the tab and the connecting sheet, the welding work of the aluminum foil still needs to be difficult due to the self characteristics of the aluminum foil after ultrasonic flat welding, the appearance quality of a welding seam is poor and has an explosion point due to the reasons of high laser energy density, excessive heat input and the like, the defects of welding heat cracks, welding air holes and the like are easy to occur in the welding seam, and the peeling strength and the internal resistance of current after the tab is welded are influenced, as shown in fig. 1.
In order to improve the quality of laser welding after ultrasonic flat welding of the aluminum foil, a suitable laser welding mode and parameters are found, heat cracks and air holes after welding of the lugs and the poles are reduced, meanwhile, the welding strength is enhanced, and the internal resistance is reduced, so that the method is one of the development directions of ultrasonic flat welding of the aluminum foil and laser welding of the poles.
Disclosure of Invention
In view of the above disadvantages of the prior art, an object of the present invention is to provide a method for welding a tab and a post of a battery, which is used to solve the problems of the prior art that the weld defects are large and the stability is poor.
In order to achieve the above and other related objects, the present invention provides a method for welding a tab and a post of a battery, comprising the steps of:
s1: carrying out ultrasonic welding on a plurality of layers of lugs of a battery cell to enable the plurality of layers of lugs to be mutually attached to form an integrated lug layer;
s2: providing a cell top cover, wherein the cell top cover is provided with a pole column penetrating through the cell top cover, a pole lug layer is correspondingly placed above the bottom surface of the pole column, and the pole lug layer is welded with the bottom surface of the pole column by laser welding; during welding, a first welding pass is formed by welding along a preset track, then a second welding pass and an nth welding pass … … are formed by reciprocating welding, and all the welding passes are sequentially arranged and are parallel to the preset track; wherein n is greater than or equal to 2.
Preferably, there is an overlap between adjacent beads of between 20% and 40% of the area of each bead.
Preferably, when n is equal to or greater than 3, the second pass through the nth pass are equally distributed on both sides of the first pass.
Preferably, in step S2, the preset trajectory is a straight line or a circle.
Preferably, in step S2, the welding laser energy of each weld pass is 60% to 85% of that of a single pass welding.
Preferably, in step S2, nitrogen with a purity of 99.9% is used for gas shielding during welding, and the gas flow is controlled to be 20-30L/min.
Preferably, in step S2, the welding speed is controlled to be 95-105 mm/min.
Preferably, in step S2, the welding is in the form of positive defocus with defocus amount of 0.6-1 mm.
The invention also provides a welding structure of a battery tab and a battery pole, which comprises:
the tab layer is formed by welding and attaching a plurality of layers of tabs;
the battery cell top cover is provided with a pole column penetrating through the battery cell top cover, and the pole lug layer is welded with the bottom surface of the pole column; more than 2 welding beads are formed at the welding position, and the welding beads are sequentially arranged and are mutually parallel.
Preferably, there is an overlap between adjacent beads of between 20% and 40% of the area of each bead.
As described above, the present invention provides a method and a structure for welding a tab and a post of a battery, in which the tab and the post are welded by a reciprocating welding method, and an overlap amount is provided between a plurality of weld beads to achieve remelting between the weld beads. Meanwhile, a series of welding parameters suitable for welding the pole and the tab are determined, wherein the welding parameters comprise welding laser energy, blowing speed, welding speed, defocusing amount and the like, so that a better welding effect is achieved. Particularly, the proper welding laser energy can ensure that the inside of the tab layer reaches a melting point before the surface of the tab layer is gasified, so that good fusion welding is favorably formed; the blowing-in of the protective gas can effectively reduce the oxidation of a welding seam molten pool and reduce the splashing in the welding process, so that the welding seam molten pool is uniformly spread when being solidified, and the appearance of the welding seam is attractive; the proper welding speed can effectively avoid the generation of hot cracks and improve the welding quality; the higher laser beam of energy density can gather at the upper surface on utmost point ear layer during the welding by positive out of focus's welding mode for utmost point ear layer surface melts fast, thereby reduces the high reflectance characteristic of aluminium foil to laser, further improves the absorptivity to laser, and can produce stable welding key hole, impels the energy of laser to the molten bath degree of depth transmission, improves the toughness of welding strength and welding seam.
The welding method can greatly reduce the generation of crack faults at the welding position of the tab and the pole, and the welding position has a smooth surface and has no defects of air holes, cracks and the like, so that the welding strength is improved, the internal resistance is reduced, the stability of the battery is improved, and the service life of the battery is prolonged.
Drawings
Fig. 1 shows a metallographic photograph of a weld of a tab and a post in the prior art.
Fig. 2 is a schematic structural view of a tab in the invention.
Fig. 3 is a schematic structural view of the pole of the present invention.
Fig. 4 is a schematic view showing the corresponding arrangement of the tab and the post in the present invention.
Fig. 5 shows a first weld bead formed when the tab and the terminal post are welded in a straight line in the present invention.
Fig. 6 shows a second weld bead formed when the tab and the terminal post are welded in a straight line in the present invention.
Fig. 7 shows a first weld bead formed when the tab and the terminal post are welded in a circular shape in the present invention.
Fig. 8 shows a second weld bead formed when the tab and the terminal post are welded in a circular shape in the present invention.
Fig. 9 shows a metallographic photograph of the present invention showing the weld of the tab and the post of the present invention.
Description of the element reference numerals
1 electric core
2 electric core top cap
11 positive pole tab layer
12 negative pole tab layer
21 positive pole
22 cathode pole
31 positive first pass
32 negative electrode first pass
34 positive second pass
35 negative second pass
41 positive electrode first weld pass
42 negative electrode first pass
43 positive second pass
45 negative second welding bead
Detailed Description
The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention.
As in the detailed description of the embodiments of the present invention, the cross-sectional views illustrating the device structures are not partially enlarged in general scale for convenience of illustration, and the schematic views are only examples, which should not limit the scope of the present invention. In addition, the three-dimensional dimensions of length, width and depth should be included in the actual fabrication.
For convenience in description, spatial relational terms such as "below," "beneath," "below," "under," "over," "upper," and the like may be used herein to describe one element or feature's relationship to another element or feature as illustrated in the figures. It will be understood that these terms of spatial relationship are intended to encompass other orientations of the device in use or operation in addition to the orientation depicted in the figures. Further, when a layer is referred to as being "between" two layers, it can be the only layer between the two layers, or one or more intervening layers may also be present. As used herein, "between … …" is meant to include both endpoints.
In the context of this application, a structure described as having a first feature "on" a second feature may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features are formed in between the first and second features, such that the first and second features may not be in direct contact.
It should be noted that the drawings provided in the present embodiment are only for illustrating the basic idea of the present invention, and the drawings only show the components related to the present invention rather than being drawn according to the number, shape and size of the components in actual implementation, and the type, quantity and proportion of each component in actual implementation may be changed freely, and the layout of the components may be more complicated.
The welding mode of utmost point ear and utmost point post is generally for the single removal welding at present, uses high-power (being 1200W commonly used) laser welder head to accomplish the welding along certain orbit (being linear shape orbit or circular orbit usually) single removal, often leads to utmost point ear surface and inside difference in temperature too big, the condition that the surface gasification appears easily but inside does not melt, leads to unable arrival abundant molten state, influences the welding seam quality. As shown in fig. 1, poor appearance quality of the weld joint is prone to cause an explosion point, defects such as welding thermal cracks and welding pores are prone to occur in the weld joint, and the peel strength and the internal resistance of current after the tab is welded are affected.
Based on the defects of the prior art, the invention provides a method for welding a battery tab and a battery pole, which comprises the following steps:
s1: carrying out ultrasonic welding on a plurality of layers of lugs of a battery cell to enable the plurality of layers of lugs to be mutually attached to form an integrated lug layer;
s2: providing a cell top cover, wherein the cell top cover is provided with a pole column penetrating through the cell top cover, a pole ear layer is correspondingly placed above the bottom surface of the pole column, and the pole ear layer and the pole column are welded by laser welding; during welding, a first welding pass is formed by welding along a preset track, then a second welding pass and an nth welding pass … … are formed by reciprocating welding, and the welding passes are sequentially arranged and are parallel to the preset track.
Further, there is an overlap between adjacent beads, the overlap being 20% to 40%, preferably 30%, of the area of each bead. Wherein n is greater than or equal to 2.
Specifically, as shown in fig. 2, a plurality of tabs are connected to the battery cell 1, and a positive tab layer 11 and a negative tab layer 12 are formed on the plurality of tabs subjected to ultrasonic welding in step S1. Preferably, the tab layer may be a multi-layer tab formed by stacking 50-60 layers of aluminum foil. Through carrying out ultrasonic wave prewelding to multilayer utmost point ear, can realize realizing the inseparable laminating state between the multilayer utmost point ear to for follow-up being connected with the utmost point post provides good welding basic condition, guarantee with the welding effect of utmost point post. In the process, the multi-layer pole lugs can be compressed through special compressing equipment, so that the multi-layer pole lugs are tightly attached. The ultrasonic welding used in the process is to transmit high-frequency vibration waves to the surfaces of two objects to be welded, and the surfaces of the two objects are mutually rubbed under the condition of pressurization to form fusion between molecular layers, so that the purpose of welding is achieved. When metal is subjected to ultrasonic welding, current is not transmitted to a workpiece, a high-temperature heat source is not applied to the workpiece, and the wireframe vibration energy is converted into friction work, deformation energy and limited temperature rise among the workpieces under the static pressure. The metallurgical bonding between the joints is a solid state welding realized under the condition that the base metal is not melted, so that the phenomena of splashing, oxidation and the like generated during resistance welding are effectively overcome. Therefore, the ultrasonic welding is also widely applied to the welding fields of silicon controlled rectifier leads, fuse pieces, electric appliance leads, lithium battery pole pieces and the like, and is particularly suitable for the tab welding in the invention.
Specifically, in step S2, a multiple-pass reciprocating welding mode is adopted, so that the welding strength can be effectively improved, meanwhile, an overlapping amount exists between each pass, and the welding effect is further improved.
As an example, as shown in fig. 3, the positive electrode post 21 and the negative electrode post 22 both penetrate through the cell top cap 2, the bottom surfaces of the positive electrode post 21 and the negative electrode post 22 are used for being welded with the positive electrode tab layer 11 and the negative electrode tab layer 12, respectively, and the top surfaces of the positive electrode post 21 and the negative electrode post 22 opposite to the bottom surfaces are used for leading out electrodes, when welding, as shown in fig. 4, the positive electrode tab layer 11 and the negative electrode tab layer 12 are correspondingly placed above the bottom surfaces of the positive electrode post 21 and the negative electrode post 22, and here, the tab layers and the posts are also compressed by a special compressing mechanism, so that the distance between the tab layers and the bottom surfaces of the posts is ensured to be less than 0.05mm, the relative positions of the tab posts are ensured to be accurate, and the tab posts are compressed without gaps after being overlapped, thereby avoiding defects such as air holes after welding. Here, it should be ensured that the positioning error of the tab clamp is less than or equal to 0.5mm (in the height direction or width direction of the tab) so as to accurately align the positions of the tab and the pole.
As an example, fig. 5 to 6 illustrate a welding process in which two weld beads are formed along a straight line, and taking a positive electrode as an example, a straight positive electrode first weld bead 31 is first formed along a straight line at a contact portion of the positive electrode tab layer 11 and the bottom surface of the positive electrode post 21, and then a straight positive electrode second weld bead 34 is formed on one side of the first weld bead 31, wherein an overlap amount is provided between the positive electrode first weld bead 31 and the positive electrode second weld bead 34. The welding process of the negative electrode is similar to that of the positive electrode, and the first weld pass 32 of the negative electrode is formed first, and then the second weld pass 35 of the negative electrode is formed, and the first weld pass 32 of the negative electrode and the second weld pass 35 of the negative electrode have an overlapping amount, which is not described again here.
As an example, fig. 7 to 8 illustrate a welding process in which two weld beads are formed along a circular path, and here, also taking a positive electrode as an example, a circular positive electrode first weld bead 41 is first formed along a circular path at a contact portion of the positive electrode tab layer 11 and the bottom surface of the positive electrode post 21, and then a circular positive electrode second weld bead 43 is formed again on one side of the first weld bead 41, wherein an overlap amount is provided between the positive electrode first weld bead 41 and the positive electrode second weld bead 43. The welding process of the negative electrode is similar to that of the positive electrode, and the first weld pass 42 of the negative electrode is formed first, and then the second weld pass 45 of the negative electrode is formed, and the first weld pass 42 of the negative electrode and the second weld pass 45 of the negative electrode have an overlapping amount, which is not described again here.
Here, the welding locus is only a linear or circular welding locus, and actually, the welding locus is not limited to these two welding loci, and may be in various forms such as a Z-shape, a polygon shape, or an irregular shape. Meanwhile, here, a welding form of only two welding passes is shown, and actually, a plurality of welding passes such as 3 welding passes and 4 welding passes may be adopted. Preferably, when the total number of passes is 3 or more (i.e., n is 3 or more), the second to nth passes are evenly distributed on both sides of the first pass, and specifically, the second to nth passes may be alternately formed on both sides of the first pass, for example, the second pass may be formed first on the left side of the first pass, then the third pass may be formed on the right side of the first pass, then the fourth pass may be formed on the left side of the first pass, and then the fifth pass … … may be formed on the right side of the first pass so that the passes are evenly distributed to improve stability.
Besides the welding mode, the invention also provides the welding parameters of the tab and the pole in the step S2 to achieve better welding effect, and the specific parameters are as follows:
further, the welding laser energy of each weld pass is 60% to 85%, preferably 75%, of a single pass weld. In the prior art, the energy of single-time moving welding is 1200W, and the preferable welding laser energy in the embodiment is 900W, so that under the low power of 900W, the time consumption for the surface of the tab layer made of aluminum to reach the aluminum melting point of 660 ℃ is longer, and the inside of the tab layer is ensured to reach the melting point before the surface of the tab layer is gasified, thereby being beneficial to forming good fusion welding.
Further, during welding, welding is performed by gas protection, in the embodiment, nitrogen with the purity of 99.9% is used for gas protection, and the gas flow is controlled to be 20-30L/min, preferably 25L/min. In addition to nitrogen, argon or the like may be used as a protective gas. The blowing-in of the protective gas can effectively reduce the oxidation of a welding seam molten pool and reduce the splashing in the welding process, so that the welding seam molten pool is uniformly spread when being solidified, and the appearance of the welding seam is attractive; in addition, weld pores can be effectively reduced. The flow of the protective gas is limited in the process, and the phenomenon that the flow is too large or too small, otherwise, weld pool metal of a weld joint is seriously interfered by external force to cause weld joint collapse or uneven forming is avoided. Therefore, the air flow in the embodiment is controlled to be 20-30L/min, so that the welding method is suitable for welding the pole ear and the pole.
Further, in the present embodiment, the welding speed is limited, and the welding speed is controlled to be 95-105mm/min, preferably 100 mm/min. For the welding of the tab and the pole, when the welding speed is too low, the melting time is long, and longitudinal hot cracks are easily formed in a welding seam; when the welding speed is too high, the melting time is short, and transverse hot cracks are easy to appear in the welding seam. Therefore, the welding speed is controlled at 100mm/min, thereby avoiding the generation of hot cracks and improving the welding quality.
Further, the welding in this embodiment is in a positive defocusing form, and the defocusing amount is 0.6-1mm, and preferably 0.8 mm. Defocusing amount is the distance between a laser focus and a welding workpiece, and in the welding process, because the power density of the center of a light spot at the laser focus is too high, holes are easy to evaporate and form. The power density distribution is relatively uniform in each plane away from the laser focal point. In the embodiment, positive defocusing is selected during welding, and laser beams with higher energy density are gathered on the upper surface of the tab layer during welding, so that the surface of the tab layer is quickly melted, the high-reflection characteristic of the aluminum foil to laser is reduced, the laser absorption rate is further improved, a stable welding keyhole can be generated, the energy of the laser is enabled to be transmitted to the depth of a molten pool, and the welding strength and the toughness of a welding seam are improved. The method avoids the serious collapse of welding seams and the great reduction of strength caused by the gasification and fusion leakage of alloy elements due to the overlarge energy inside the aluminum alloy. The combination of 900W power and 100mm/min welding speed can effectively reduce the collapse of the upper surface of the welding line and the hump of the bottom, and the welding line has smooth surface and good mechanical property.
As shown in FIG. 9, the invention greatly reduces the generation of crack faults at the welding position by reasonably reciprocating low-power repeated welding and matching with reasonable welding speed, defocusing amount and proper blowing speed, and the surface of the welding position is smooth and has no defects of air holes, cracks and the like. The following table shows 32 sets of experimental data for post-weld tensile testing, and in the positive example, 32 sets of data indicate that the weld can withstand a maximum 115N tensile force.
| Serial number | Tension force | Serial number | Tension force | Serial number | Tension force | Serial | Tension force | |
| 1 | 101N | 9 | 108N | 17 | 101N | 25 | |
|
| 2 | 102N | 10 | 92N | 18 | 99N | 26 | 107N | |
| 3 | |
11 | 89N | 19 | 88N | 27 | 95N | |
| 4 | |
12 | 96N | 20 | 96N | 28 | 95N | |
| 5 | 113N | 13 | |
21 | 83N | 29 | 99N | |
| 6 | 108N | 14 | |
22 | 82N | 30 | 94N | |
| 7 | 92N | 15 | 107N | 23 | |
31 | 97 | |
| 8 | 93N | 16 | 100N | 24 | |
32 | 115N |
The present invention also provides a welding structure of a tab and a pole, which can be formed by the above welding method, but is not limited to the above welding method, and the welding structure specifically includes:
the tab layer is formed by welding and attaching a plurality of layers of tabs;
the battery cell top cover is provided with a pole column penetrating through the battery cell top cover, and the pole lug layer is welded with the bottom surface of the pole column; more than 2 welding beads are formed at the welding position, and the welding beads are sequentially arranged and are mutually parallel.
Further, there is an overlap between adjacent beads, the overlap being 20% to 40%, preferably 30%, of the area of each bead. The shape of the welding bead can be linear or circular, and can also be Z-shaped, polygonal or irregular.
Specifically, as shown in fig. 6 and 8, the positive electrode post 21 and the negative electrode post 22 both penetrate through the cell top cover 2, the bottom surfaces of the positive electrode post 21 and the negative electrode post 22 are used for welding with the positive electrode tab layer 11 and the negative electrode tab layer 12, respectively, and the welding position is formed with more than 2 weld beads, for example, a positive electrode first weld bead 31 and a positive electrode second weld bead 34 are formed at the positive electrode position in fig. 6, wherein an overlapping amount exists between the first weld bead 31 and the second weld bead 34. Because the second weld bead and the first weld bead have overlapping amount, the second weld bead is necessarily formed at the edge of the first weld bead, and the edge of the first weld bead is also necessarily remelted again in the process of forming the second weld bead, so that the first weld bead and the second weld bead can be integrated, the occurrence of fracture is avoided, and the welding effect is improved.
In summary, the present invention provides a method and a structure for welding a tab and a post of a battery, in which the tab and the post are welded in a reciprocating welding manner, and a plurality of welding passes are overlapped to achieve remelting between the welding passes. Meanwhile, a series of welding parameters suitable for welding the pole and the tab are determined, wherein the welding parameters comprise welding laser energy, blowing speed, welding speed, defocusing amount and the like, so that a better welding effect is achieved. Particularly, the proper welding laser energy can ensure that the inside of the tab layer reaches a melting point before the surface of the tab layer is gasified, so that good fusion welding is favorably formed; the blowing-in of the protective gas can effectively reduce the oxidation of a welding seam molten pool and reduce the splashing in the welding process, so that the welding seam molten pool is uniformly spread when being solidified, and the appearance of the welding seam is attractive; the proper welding speed can effectively avoid the generation of hot cracks and improve the welding quality; the higher laser beam of energy density can gather at the upper surface on utmost point ear layer during the welding by positive out of focus's welding mode for utmost point ear layer surface melts fast, thereby reduces the high reflectance characteristic of aluminium foil to laser, further improves the absorptivity to laser, and can produce stable welding key hole, impels the energy of laser to the molten bath degree of depth transmission, improves the toughness of welding strength and welding seam.
The welding method can greatly reduce the generation of crack faults at the welding position of the tab and the pole, and the welding position has a smooth surface and has no defects of air holes, cracks and the like, so that the welding strength is improved, the internal resistance is reduced, the stability of the battery is improved, and the service life of the battery is prolonged.
The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.
Claims (10)
1. A method for welding a battery tab and a battery post is characterized by comprising the following steps:
s1: carrying out ultrasonic welding on a plurality of layers of lugs of a battery cell to enable the plurality of layers of lugs to be mutually attached to form an integrated lug layer;
s2: providing a cell top cover, wherein the cell top cover is provided with a pole column penetrating through the cell top cover, a pole lug layer is correspondingly placed above the bottom surface of the pole column, and the pole lug layer is welded with the bottom surface of the pole column by laser welding; during welding, a first welding pass is formed by welding along a preset track, then a second welding pass and an nth welding pass … … are formed by reciprocating welding, and all the welding passes are sequentially arranged and are parallel to the preset track; wherein n is greater than or equal to 2.
2. The welding method of claim 1, wherein adjacent weld beads have an overlap therebetween, the overlap being between 20% and 40% of the area of each weld bead.
3. The welding method according to claim 1, wherein when n is 3 or more, the second pass to the nth pass are equally distributed on both sides of the first pass.
4. The welding method according to claim 1, wherein in step S2, the predetermined trajectory is a straight line or a circle.
5. The welding method according to claim 1, wherein in step S2, the welding laser energy of each weld pass is 60% -85% of that of a single-pass welding.
6. The welding method according to claim 1, wherein in step S2, nitrogen gas with a purity of 99.9% is used for gas shielding during welding, and the gas flow rate is controlled to be 20-30L/min.
7. The welding method according to claim 1, wherein in step S2, the welding speed is controlled to 95-105 mm/min.
8. The welding method according to claim 1, wherein in step S2, the welding is in a positive defocus form, and the defocus amount is 0.6-1 mm.
9. The utility model provides a welded structure of battery tab and utmost point post which characterized in that includes:
the tab layer is formed by welding and attaching a plurality of layers of tabs;
the battery cell top cover is provided with a pole column penetrating through the battery cell top cover, and the pole lug layer is welded with the bottom surface of the pole column; more than 2 welding beads are formed at the welding position, and the welding beads are sequentially arranged and are mutually parallel.
10. The welding structure of claim 9, wherein adjacent weld beads have an overlap therebetween, the overlap being between 20% and 40% of the area of each weld bead.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210664916.1A CN114976510A (en) | 2022-06-13 | 2022-06-13 | Welding method and welding structure of battery tab and pole |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210664916.1A CN114976510A (en) | 2022-06-13 | 2022-06-13 | Welding method and welding structure of battery tab and pole |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114976510A true CN114976510A (en) | 2022-08-30 |
Family
ID=82961293
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210664916.1A Pending CN114976510A (en) | 2022-06-13 | 2022-06-13 | Welding method and welding structure of battery tab and pole |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114976510A (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112421188A (en) * | 2020-10-30 | 2021-02-26 | 蜂巢能源科技有限公司 | Welding method of tab and cover plate, battery module, battery pack and vehicle |
| CN112453735A (en) * | 2020-10-09 | 2021-03-09 | 湖北亿纬动力有限公司 | Tab welding method, battery manufacturing method and battery |
| CN113385814A (en) * | 2021-06-21 | 2021-09-14 | 远景动力技术(江苏)有限公司 | Laser welding method and device for multilayer tabs and lithium battery |
| CN113714636A (en) * | 2021-08-31 | 2021-11-30 | 广东利元亨智能装备股份有限公司 | Laser welding method for multilayer tabs |
-
2022
- 2022-06-13 CN CN202210664916.1A patent/CN114976510A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112453735A (en) * | 2020-10-09 | 2021-03-09 | 湖北亿纬动力有限公司 | Tab welding method, battery manufacturing method and battery |
| CN112421188A (en) * | 2020-10-30 | 2021-02-26 | 蜂巢能源科技有限公司 | Welding method of tab and cover plate, battery module, battery pack and vehicle |
| CN113385814A (en) * | 2021-06-21 | 2021-09-14 | 远景动力技术(江苏)有限公司 | Laser welding method and device for multilayer tabs and lithium battery |
| CN113714636A (en) * | 2021-08-31 | 2021-11-30 | 广东利元亨智能装备股份有限公司 | Laser welding method for multilayer tabs |
Non-Patent Citations (1)
| Title |
|---|
| 肖海兵、钟正根、宋长辉等: "《激光智能制造技术》", vol. 1, 华中科技大学出版社, pages: 170 - 180 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP3594555B2 (en) | Manufacturing method of sealed battery and sealed battery | |
| JP2016030280A (en) | Method and apparatus for laser welding of metal foil | |
| CN108465933A (en) | A kind of method and apparatus of laser welding foil and lug | |
| JP2017098565A5 (en) | ||
| CN102201591A (en) | Battery module and method of manufacturing the same | |
| CN113458635A (en) | Method for welding tab and cover plate and battery assembly | |
| CN103500844B (en) | cylindrical multi-lug lithium ion battery and preparation method thereof | |
| CN114833446B (en) | Full laser welding manufacturing method for battery | |
| CN104638223A (en) | Welding structure for plate electrode foils and plate lug of lithium battery | |
| CN215418352U (en) | Welding structure of steel shell button cell and button cell | |
| CN204834594U (en) | Power semiconductor | |
| CN106229429A (en) | A kind of dual wavelength complex welding method of cover plate of power battery | |
| JP2011159445A (en) | Battery device and inter-terminal connection method of the same | |
| CN105140429A (en) | Laminated lithium battery aluminum shell structure and manufacturing method thereof | |
| CN112045307B (en) | Laser welding method for soft package lithium ion power battery tab | |
| CN114976510A (en) | Welding method and welding structure of battery tab and pole | |
| JP5546997B2 (en) | Welding method, battery manufacturing method, and battery | |
| CN113794028B (en) | Lithium battery and welding process of explosion-proof valve of lithium battery | |
| CN211743291U (en) | Lithium ion battery's electric connection structure and lithium ion battery who has it | |
| CN115283868B (en) | Laser welding method for aluminum foil tab and pole post after ultrasonic welding | |
| KR20180065206A (en) | Laser Welding Jig Providing Improved Laser Weldability | |
| CN212577845U (en) | Back protection device for alloy laser forming connection | |
| JPH0877983A (en) | Manufacture of sealed type rectangular battery | |
| CN113172306A (en) | Hollow electrode wire feeding electric arc additive manufacturing system and method | |
| CN112643203A (en) | Workpiece welding method, electrode assembly, single battery and electric equipment |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |