Battery bus piece and battery

Abstract

The utility model provides a battery confluence piece and battery, the confluence piece comprises a confluence piece body and a welding area, the confluence piece body is provided with a first surface used for contacting a roll core and a second surface opposite to the first surface, at least part of the second surface is provided with the welding area, and the welding area is provided with a plurality of welding holes. And the laser reflectivity of the welding area is lower than that of the first surface. According to the utility model, the welding area with low laser reflectivity is arranged on the confluence sheet, so that the surface of the confluence sheet can better absorb laser energy, and the welding efficiency and precision are improved. Meanwhile, heat and temperature generated in the laser welding process can be reduced through the welding area with the low laser reflectivity, and therefore the performance and stability of the roll core assembly are protected.

Description

Technical Field

[0001] This utility model relates to the field of novel battery manufacturing, and in particular to a battery busbar and a battery. Background Technology

[0002] Laser welding is a high-precision welding technology widely used in battery manufacturing and assembly, such as welding busbars to battery cores. The principle of laser welding is to use a high-energy laser beam to heat the welding materials, melting their surface and forming a stable weld joint upon cooling. Compared to traditional resistance welding or ultrasonic welding, laser welding offers advantages such as faster welding speed, higher weld quality, and no thermal damage to surrounding materials.

[0003] The inventors discovered in their production research and practice that, despite the advantages of laser welding, the welding effect between busbars and cores is sometimes difficult to guarantee, resulting in suboptimal weld quality and even issues such as incomplete or non-fused weld points. While increasing the welding speed can compensate for this, excessively fast welding speeds can lead to a decline in weld quality. Therefore, it is urgent to identify the causes and solutions for poor laser welding quality.

[0004] In addition, batteries sometimes overheat, leading to issues such as core explosions. The cause of this phenomenon still needs further investigation. Utility Model Content

[0005] One aspect of this invention provides a battery busbar with a welding zone having low laser reflectivity. This allows the busbar surface to better absorb laser energy, thereby improving welding efficiency and precision. Simultaneously, the low laser reflectivity welding zone also reduces the heat and temperature generated during laser welding, thus protecting the performance and stability of the core assembly.

[0006] One aspect of this utility model provides a battery busbar, the busbar including a busbar body having a first surface for contacting the end of a winding core and a second surface opposite to the first surface;

[0007] At least a portion of the second surface is provided with a welding area, which is used to weld the portion of the first surface corresponding to the welding area to the end of the core when irradiated by a laser.

[0008] The laser reflectivity of the welding area is lower than that of the first surface.

[0009] In some implementations, the welded area is hydrophilic.

[0010] In some embodiments, the welding area is at least a hydrophilically treated portion of the second surface, the hydrophilic treatment including applying a plating layer, a spraying layer, a dip coating layer, or an adhesive layer, performing plasma treatment, and / or performing an oxidation treatment.

[0011] In some embodiments, the material of the coating, spray coating, dip coating, or adhesive layer is selected from inorganic materials, which are selected from one or more of magnesium oxide, silicon oxide, zirconium oxide, titanate, and magnesium aluminum fluoride;

[0012] The material of the busbar body is selected from copper, tin or aluminum.

[0013] In some implementations, a central hole is provided in the middle of the busbar body, and the welding area is arranged around the central hole.

[0014] In some implementations, the welding zones are multiple and centrally symmetrically distributed on the outside of the axial hole.

[0015] In some embodiments, the busbar further includes a current-drawing tab for drawing out current, the current-drawing tab being connected to the busbar body.

[0016] In some implementations, the drain plate also includes a welding area.

[0017] In some embodiments, the welding area of ​​the drain plate and the welding area of ​​the second surface are located on the same side or opposite side of the busbar.

[0018] In some implementations, the drain plate is connected to the manifold body via a folded drain region, the folded drain region being provided with a fusible area that reduces the flow guiding area.

[0019] In some implementations, the folded drainage area includes a first folded area, a second folded area, and a connecting area, wherein the first folded area folds and connects the connecting area and the drainage plate, and the second folded area folds and connects the connecting area and the manifold body.

[0020] In some implementations, the first folded region and / or the second folded region are provided with through holes, the through holes extending to the portion adjacent to the first folded region and / or the second folded region, the adjacent portion may be a guide vane, a connecting region, and a busbar body;

[0021] When the folded drainage area is in a folded state, at least a portion of the through hole overlaps axially with the central hole of the manifold body.

[0022] Another aspect of this utility model provides a battery, the battery including a winding core and the aforementioned busbar, the busbar being laser-welded to the end of the winding core.

[0023] In some implementations, the busbar is laser-irradiated to form multiple solder joints, which are discrete solder joints arranged in multiple rows.

[0024] In some implementations, the busbar has multiple solder joints, which are continuous and are formed in a straight line, S-shape, or U-shape.

[0025] Another aspect of this invention provides a method for preparing the above-mentioned busbar.

[0026] In some embodiments, the method for preparing a busbar for laser welding includes: hydrophilic treatment of a second surface of the busbar body to form a welding zone.

[0027] In some embodiments, the hydrophilic treatment includes, for example, the following steps: preparing an inorganic coating for the welding area; optionally passivating the second surface of the busbar body, such as by grinding or etching; then applying the inorganic coating to the surface of the second surface of the busbar body, for example by coating, spraying, dipping or bonding; and then curing the inorganic coating, for example by drying at a temperature of 80 to 120°C for 10 to 14 hours to allow the dispersion medium to evaporate, thereby obtaining a welding area formed on the second surface of the busbar body.

[0028] In some embodiments, the inorganic coating is selected from one or more of magnesium oxide, silicon oxide, zirconium oxide, titanate, and magnesium aluminum fluoride.

[0029] Another aspect of this invention provides a method for preparing a battery.

[0030] In one embodiment, the aforementioned busbar can be disposed at the positive or negative terminal of the battery.

[0031] In one embodiment, the aforementioned busbar is disposed at the negative electrode of the battery. Specifically, the preparation method includes the following steps: stacking the outer casing, the negative electrode busbar, and the winding core, and performing laser welding; attaching the first side of the busbar body in any of the aforementioned embodiments to the positive end of the winding core, wherein the axis of the winding core is aligned with and pressed against the central hole of the busbar body; performing laser welding on the welding area of ​​the second side of the busbar body; and injecting electrolyte into the winding core.

[0032] In one embodiment, the preparation method further includes: bending the first folded region and the second folded region in opposite directions to fold the busbar body and the guide plate; covering the positive terminal on top of the guide plate and sealing the battery. Attached Figure Description

[0033] To better understand the above and other objects, features, advantages, and functions of this utility model, reference can be made to the preferred embodiments shown in the accompanying drawings. The same reference numerals in the drawings refer to the same parts. Those skilled in the art should understand that the drawings are intended to schematically illustrate the preferred embodiments of this utility model and do not limit the scope of this utility model in any way; the parts in the drawings are not drawn to scale.

[0034] Figure 1 A schematic diagram of a busbar according to one aspect of the present invention and its arrangement with the winding core is shown.

[0035] Figure 2-3 A schematic diagram of the structure of a busbar according to one aspect of the present invention is shown.

[0036] Figure 4-5 A schematic diagram of the structure of a busbar according to another aspect of the present invention is shown.

[0037] Figure 6-7 A schematic diagram of the structure of a busbar according to another aspect of the present invention is shown.

[0038] Figure 8 A disassembly diagram of the battery according to the present invention is shown.

[0039] Figure Labels

[0040] 1-Busset body

[0041] 11-First Page

[0042] 12-Second page

[0043] 13-Spindle Hole

[0044] 14- Solder joint

[0045] 2-Welding Zone

[0046] 3-Drainage Piece

[0047] 31-First Folding Area

[0048] 32-Second Folding Area

[0049] 33-Connection Area

[0050] 34-Through Hole

[0051] 100-core

[0052] 200-busbar Detailed Implementation

[0053] Before explaining any embodiment in detail, it should be understood that the application of the embodiment is not limited to the details of the configuration and arrangement of components set forth in the following description or shown in the accompanying drawings. The embodiment can be practiced or implemented in various ways. What is described herein is merely a preferred embodiment according to the present invention; those skilled in the art can conceive of other ways to implement the present invention based on the preferred embodiments, and such other ways also fall within the scope of the present invention.

[0054] Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art. In case of conflict, this invention (including definitions) shall prevail. Only exemplary methods and materials are described below; similar or equivalent methods and materials described herein may be used in the experiments or tests of this invention. The materials, methods, and examples disclosed in this invention are illustrative only and are not intended to be limiting. Regarding the description of numerical ranges in this invention, each intermediate number is explicitly contemplated to have the same degree of precision.

[0055] Figures 1-8 The battery busbar according to this utility model is shown. It should first be noted that the directional and positional terms used in this utility model should be understood as relative directions and positions, not absolute directions and positions. The directional and positional terms used in this utility model can be referred to... Figures 1-8 The exemplary structure shown is explained.

[0056] During production research and practice, the inventors discovered that the welding quality occasionally declined during the laser welding process of busbars. After extensive investigation, they found that in the existing laser welding process, the slight difference in the laser reflectivity of the surface of different batches of busbars caused a large amount of laser energy to be reflected and scattered on the metal surface, making it impossible to fully utilize the laser energy. This could even lead to problems such as incomplete or insufficient fusion of the weld joints, resulting in a decrease in the yield rate.

[0057] To address the above technical problems, this utility model provides a battery busbar that can avoid the aforementioned issues. (See reference below.) Figures 1 to 7 A preferred embodiment of the present invention provides a battery busbar 200, the busbar 200 including a busbar body 1, the busbar body 1 having a first surface 11 for contacting the end of a winding core 100 and a second surface 12 opposite to the first surface 11; at least a portion of the second surface 12 is provided with a welding area 2, the welding area 2 being used to weld the portion of the first surface 11 corresponding to the welding area 2 to the end of the winding core 100 when irradiated by a laser; the laser reflectivity of the welding area 2 is lower than the laser reflectivity of the first surface 11.

[0058] Normally, the relative surfaces of the busbar 200 have similar laser reflectivity. In order to reduce laser reflection on the welding surface during the laser welding process, the welding area 2 with lower reflectivity is used to cover the second surface 12, thereby concentrating energy and reducing dissipation. This also improves the stability of the laser welding process, prevents problems caused by different reflectivity of the busbar surfaces in different batches, and improves the yield.

[0059] In this invention, the first surface 11 and the second surface 12 are relative. The first surface is used to contact the winding core 100, while the second surface 12 is on the back side of the first surface 11 and is used to contact the end of the electrode. See reference [link / reference needed] for details. Figure 1 The indicated position in the diagram.

[0060] The busbar material can be any available material. In one embodiment, the material of the busbar body 1 is selected from copper, tin or aluminum.

[0061] The purpose of the welding area 2 in this invention is to reduce and make the laser reflectivity of the busbar surface approximately uniform, preventing a decrease in yield due to batch variations. In one embodiment, the welding area 2 is hydrophilic. For example, the welding area 2 is at least a portion of the second surface 12 that has undergone hydrophilic treatment. By hydrophilically treating the surface of the second surface 12 to form the welding area 2, its hydrophilicity is made greater than that of the surface of the busbar body 1 (e.g., the second surface 12), while simultaneously reducing laser reflectivity. The hydrophilic treatment is related to the laser reflectivity of the second surface 12. Generally, the smoother the surface, the lower the hydrophilicity (e.g., smooth glass), while the rougher the surface, the higher the hydrophilicity (e.g., frosted glass). By improving the hydrophilicity (roughness) of the welding area through hydrophilic treatment, the effect of reducing laser reflectivity is achieved.

[0062] In some embodiments, the hydrophilic treatment includes applying a plating layer, a spraying layer, an immersion coating layer, or an adhesive layer, performing plasma treatment, and / or performing an oxidation treatment. The welding area 2 can be set on the surface of the second surface 12 by known methods. Generally, materials and / or methods that reduce laser reflectivity are preferred.

[0063] In one embodiment, the hydrophilic coating is both insulating and non-reactive with the electrolyte, and does not generate other impurities during the welding process. Therefore, the hydrophilic surface coating is more preferably an inorganic material treatment layer, while organic materials are generally not preferred because they can carbonize and generate impurities during high-temperature welding.

[0064] In one embodiment, the material of the coating, spray coating, dip coating, or adhesive layer is selected from inorganic metal materials and inorganic non-metal materials, wherein the inorganic metal materials include, but are not limited to, one or more of the following groups: magnesium oxide, silicon oxide, zirconium oxide, titanate, magnesium aluminum fluoride, etc.; and the inorganic non-metal materials include, but are not limited to, the following groups: diatomaceous earth, kaolin, glass, ceramics, etc.

[0065] The method for measuring laser reflectivity is known in the art, for example, by using a reflectivity meter. In one embodiment, the laser reflectivity of the welding area 2 is less than 70% of the laser reflectivity of the first surface 11; in a preferred embodiment, the laser reflectivity of the welding area 2 is less than 60% of the laser reflectivity of the first surface 11; in a more preferred embodiment, the laser reflectivity of the welding area 2 is less than 50% of the laser reflectivity of the first surface 11; and in the most preferred embodiment, the laser reflectivity of the welding area 2 is less than 40% of the laser reflectivity of the first surface 11.

[0066] Under normal circumstances, if the busbar body is not specially treated, the laser reflectivity of its first surface 11 and second surface 12 should be the same or substantially the same (preferably within ±10%, more preferably within ±5%, and even more preferably within ±2%). Therefore, when the second surface 12 is completely covered by the welding area 2, it is more convenient and faster to measure and compare the laser reflectivity of the first surface 11 and the welding area 2.

[0067] The size of the busbar can be set according to actual production needs and adjusted according to the battery size. In one embodiment, the thickness of the busbar is 0.1 to 0.5 mm, preferably 0.1 to 0.3 mm, more preferably 0.15 to 0.25 mm, and most preferably 0.18 to 0.22 mm.

[0068] There are no specific requirements for the thickness of the welding area 2, but it should not be too thick to affect laser penetration, nor too thin to affect laser absorption. In one embodiment, the thickness of the welding area 2 is less than 10% of the thickness of the busbar body 1, preferably less than 8% of the thickness of the busbar body 1, more preferably less than 5% of the thickness of the busbar body 1, and most preferably less than 3% of the thickness of the busbar body 1.

[0069] In one implementation, reference Figure 1-7A central hole 13 is provided in the center of the busbar body 1, and a welding area 2 is arranged around the central hole 13. The function of the central hole is to facilitate the injection of electrolyte into the battery. During the welding process, the central hole 13 is aligned with the center hole of the core 100 to facilitate the injection of electrolyte during subsequent battery installation. Preferably, the welding area 2 can partially or completely cover the entire second surface 12, thereby reducing surface laser reflection during laser welding and thus reducing energy consumption. Simultaneously, there are multiple welding areas 2, which are centrally symmetrically distributed on the outer side surrounding the central hole 13 to ensure a uniform distribution of the welding bond between the busbar 200 and the core 100. Figure 1-7 The triangular distribution in the middle.

[0070] In one embodiment, the welding area can be electrically welded to the end of the core or integrally welded. Preferably, each welding area 2 includes multiple arrayed, discrete, or continuous weld points, and the welding area 2 is welded to the core by radiating individual weld points in the array with a laser. Preferably, the multiple weld points are continuous weld points, forming a straight line, S-shape, or U-shape.

[0071] In one embodiment, each welding zone 2 includes 8 or more weld points, preferably 12 or more weld points, and more preferably 16 or more weld points.

[0072] For reference Figure 2-7 The busbar also includes a current-guiding piece 3 for drawing out current, which is connected to the busbar body 1. The current-guiding piece 3 and the busbar body 1 can be made of the same material or different materials. The current-guiding piece 3 and the busbar body 1 can be integrally formed or welded together. The function of the current-guiding piece 3 is to guide the current collected by the busbar body 1 to the outside.

[0073] During battery assembly, in order to reduce the height of the battery cap structure and maximize the capacity of the active material, the guide plate 3 should minimize its axial space occupation. For example, Figure 2-7 As shown, the current-guiding plate 3 is connected to the current-collecting plate body 1 through a folded current-guiding area, and the current-guiding plate 3, the folded current-guiding area, and the current-collecting plate body 1 are stacked in sequence. This arrangement increases the connection area between the current-guiding plate 3 and the battery end, while reducing the axial area it occupies.

[0074] In one method of setting up a drainage patch, such as... Figure 3-7As shown, the folded drainage area includes a first folded area 31, a second folded area 32, and a connecting area 33. The first folded area 31 folds and connects the connecting area 33 and the drainage piece 3, while the second folded area 32 folds and connects the connecting area 33 and the busbar body 1. By providing two folded areas, the connection between the folded area and the connecting area 33 and the drainage piece 3 can be better achieved, and the folded drainage area can act like a spring, using tension to better compress the drainage piece 3 and the battery end.

[0075] In some cases, batteries may overheat, leading to issues such as core explosion. After investigation and experimentation, it was found that excessive current at the busbar can easily cause overheating and core explosion. To address this problem, the folded current-guiding area is equipped with a fusible region with a reduced current-conducting area. Due to the reduced current-conducting area, the resistance of this fusible region increases, making it more prone to overheating and melting, thus providing a safety function. This invention does not specifically limit the way the fusible region is designed; anything that achieves the above function is acceptable.

[0076] In one implementation, such as Figure 6 As shown, the drain plate 3 also includes a welding area 2. The welding area 2 of the drain plate 3 and the welding area 2 of the second surface 12 are located on the same side or opposite side of the manifold. For example, the position of the welding area 2 on the drain plate depends on the number of folds; if folded into an S-shape, the welding area 2 is the back side; if folded into a C-shape, the welding area 2 is the front side.

[0077] In one implementation, such as Figure 6-7 As shown, the drain plate 3 is connected to the manifold body 1 through a folded drain region, and the folded drain region is provided with a fusible area that reduces the flow guiding area. For example, the folded drain region includes a first folded region 31, a second folded region 32, and a connecting region 33.

[0078] In a preferred embodiment, the first folded region 31 and / or the second folded region 32 are provided with through holes 34, which extend to the adjacent portion of the first folded region 31 and / or the second folded region 32. For example, the through hole can span the folded region and the connecting region or the folded region and the drain plate to achieve fusion at the connection.

[0079] In one implementation, such as Figure 6-7 As shown, when the folded drainage area is in a folded state, at least a portion of the through hole 34 overlaps axially with the central hole 13 of the manifold body 1. This arrangement facilitates electrolyte injection and prevents problems such as slow injection flow or slow speed that can occur with the drainage plate. In another embodiment, as... Figure 4-5As shown, the connecting region 33 is a narrow region with a current-conducting area smaller than that of the current-guiding plate 3. Both the current-guiding plate 3 and the connecting region 33 can be sheet-like structures. The width of the connecting region 33 can be smaller than that of the current-guiding plate 3, thereby reducing the cross-sectional area through which the current flows and making the connecting region 33 more prone to overheating and melting.

[0080] In a specific embodiment, a first folded region 31 and a second folded region 32 exist between the current-leading plate 3 and the busbar body 1, as well as a narrow region extending between the first folded region 31 and the second folded region 32. The first folded region 31 separates the current-leading plate 3 from the narrow region, and the second folded region 32 separates the narrow region from the busbar body 1. Therefore, the narrow region can form an overcurrent protection device, such as a fuse, integrated with the current-leading plate 3 and the busbar body 1, so that the narrow region can melt in response to the current exceeding a predetermined value, thereby interrupting the current between the current-leading plate 3 and the busbar body 1. For example, the narrow region will melt when the current exceeds a predetermined value (e.g., the rated current of the material forming the narrow region). In one embodiment, the predetermined value may be 101% of the nominal rated current of the battery cell, preferably 110% of the nominal rated current of the battery cell, and more preferably 120% of the nominal rated current of the battery cell.

[0081] During battery assembly, to reduce the height of the battery cap structure and maximize the capacity of the active material, it is typically necessary to stack the current-guiding plate 3 and the busbar body 1. This is achieved by bending in opposite directions at the first folded region 31 and the second folded region 32. In some embodiments, the first folded region 31 and the second folded region 32 each have a bending radius and / or tolerance that allows the busbar body 1 and the current-guiding plate 3 to deform into an S-shape. In some embodiments, the narrow region may have an insulator (e.g., an insulating coating or a thin insulating strip) on at least one surface. This insulation is used to prevent short circuits between the narrow region and the busbar body 1 or the current-guiding plate 3.

[0082] For reference Figure 1 and 8In another aspect of this utility model, a battery is disclosed, comprising a winding core 100 and a busbar 200, wherein the busbar 200 is laser-welded to the end of the winding core 100. At least one weld point 14 is formed on the busbar 200 by laser irradiation, and the weld point 14 is located on the surface where the busbar body 1 and the welding area 2 are in contact. In another embodiment, a plurality of weld points 14 may be formed on the busbar 200, wherein the plurality of weld points are arranged in rows and columns along the axial direction of the winding core 100 from the outside to the inside. Furthermore, the battery also includes a casing, a first terminal disposed on one side of the casing, and a second terminal disposed on the other side of the casing. The first terminal is connected to the negative electrode of the winding core 100 via a negative busbar, and the second terminal is connected to the positive electrode of the winding core 100 via a guide plate 3 through the busbar body 1.

[0083] like Figure 1 and 8 As shown, the housing typically provides a enclosure for the electrical components of the battery cell (e.g., core 100, first terminal, negative busbar, second terminal, busbar 200, and / or similar components). In some embodiments, some or all of the electrical components are housed within the housing. In some embodiments, the housing is made of an insulating material, such as plastic or other non-conductive material. In some embodiments, the housing may be made of a conductive material, such as steel, aluminum, or other conductive metals.

[0084] For reference Figure 1 In another aspect of this utility model, a method for preparing a battery busbar is disclosed, which reduces the laser reflectivity of the busbar surface and improves the utilization rate of laser energy by performing hydrophilic treatment on the busbar body 1.

[0085] In one specific embodiment, the hydrophilic treatment involves forming a welding zone 2 on the surface of the busbar body 1. Specifically, this includes: preparing an inorganic coating for forming the welding zone 2; mixing alcohol and water in a ratio of 1:5 to 5:1 to form a solvent; selecting an inorganic metallic coating and / or an inorganic non-metallic coating according to this invention; mixing the solvent in a mass ratio of 1:1 to 1:5; and treating the mixture in a constant temperature water bath at 20°C to 80°C, ensuring thorough stirring and maintaining the temperature to obtain an inorganic sol-gel coating. The second surface 12 of the busbar body 1 is then passivated using a metal surface treatment passivation solution at a temperature of 60°C to 100°C for 4 to 8 hours. This metal surface treatment passivation solution can be commercially available. The inorganic sol-gel coating is then loaded onto the passivated second surface 12, wherein the loading method includes, but is not limited to, coating, spraying, dipping, or bonding the surface of the busbar body 1. The area is then dried at 80 to 120°C for 10 to 14 hours, and the loading and drying steps are repeated 1 to 3 times to obtain the welding area 2 covering the second surface of the busbar body 1. In one embodiment, the thickness of the welding area 2 is less than 10% of the thickness of the busbar body 1, preferably less than 8% of the thickness of the busbar body 1, more preferably less than 5% of the thickness of the busbar body 1, and most preferably less than 3% of the thickness of the busbar body 1.

[0086] In one embodiment, the aforementioned busbar can be disposed at either the positive or negative terminal of the battery. Now refer to... Figure 1 and Figure 8In another aspect of this utility model, a method for manufacturing a battery is disclosed: A casing, a negative electrode busbar, and a core 100 are stacked in a direction perpendicular to the bottom surface of the casing. The axis of the core 100, the negative electrode busbar, and the core 100 overlap and are pressed together with a fastener, followed by laser welding. The wavelength, power, diameter, and welding time of the laser emission are controlled to precisely focus the laser energy, which passes through the axis of the core 100 and converges to the surface of the negative electrode busbar, achieving a melting operation on the surface of the busbar. After the laser welding operation is completed, the welded components are kept warm to ensure the weld's strength and a more stable welded structure. Simultaneously, the operating power is slowly reduced, and the temperature is gradually lowered to room temperature to prevent brittle fracture of the welded structure, achieving a reliable weld between the casing and the negative electrode busbar. After completing the aforementioned assembly process, the first surface 11 of the busbar body 1 is attached to the positive electrode surface of the core 100, and the axis of the core 100 is aligned with and pressed against the central hole 13 of the busbar body 1. Laser welding is then performed on the welding area 2 of the second surface 12 of the busbar body 1. In one embodiment, when the material of the busbar body 1 is aluminum, the suitable laser frequency can be selected as 1-100Hz, preferably 2-80Hz, more preferably 10-60Hz, and most preferably 30-50Hz. Simultaneously, the radiation time and power of the laser beam can also be adaptively adjusted. If the melting point of the component to be irradiated is low and more precise structural control is required, a lower power radiation energy can be used and the radiation time can be adaptively extended to ensure sufficient welding. By efficiently receiving energy from the laser through the welding area 2, the busbar body 1 can be effectively melted without further damage to the core. After laser welding of the positive electrode is completed, electrolyte is injected. The busbar body and the guide plate are bent according to any of the aforementioned embodiments. The positive terminal is covered on top of the guide plate to seal the battery, thereby obtaining the battery structure.

[0087] The above description of various embodiments of this disclosure is provided for illustrative purposes to a person of ordinary skill in the art. It is not intended to exclude or limit the present invention to a single disclosed embodiment. As taught above, those skilled in the art will understand that various alternatives and variations of the present invention are possible. Therefore, although some alternative embodiments have been specifically described, those skilled in the art will understand or relatively easily develop other embodiments. This disclosure is intended to include all alternatives, modifications, and variations of the present invention described herein, as well as other embodiments falling within the spirit and scope of the present invention described above.

Claims

1. A battery busbar, characterized in that, The busbar (200) includes a busbar body (1) having a first surface (11) for contacting the end of the core (100) and a second surface (12) relative to the first surface (11); At least a portion of the second surface (12) is provided with a welding area (2), which is used to weld the portion of the first surface (11) corresponding to the welding area (2) to the end of the core (100) when irradiated by a laser. The laser reflectivity of the welding area (2) is lower than that of the first surface (11).

2. The battery busbar according to claim 1, characterized in that, The welding area (2) is hydrophilic.

3. The battery busbar according to claim 2, characterized in that, The welding area (2) is at least a portion of the second surface (12) that has undergone hydrophilic treatment, which includes applying a plating layer, a spraying layer, an immersion layer or an adhesive layer, performing plasma treatment, or performing oxidation treatment.

4. The battery busbar according to claim 3, characterized in that, The material of the plating layer, spraying layer, dip coating layer, or adhesive layer is selected from inorganic materials; The material of the busbar body (1) is selected from copper, tin or aluminum.

5. The battery busbar according to claim 4, characterized in that, The inorganic material is selected from one of magnesium oxide, silicon oxide, zirconium oxide, titanate, and magnesium aluminum fluoride.

6. The battery busbar according to claim 1, characterized in that, The busbar body (1) has a central hole (13) in the middle, and the welding area (2) is arranged around the central hole (13).

7. The battery busbar according to claim 6, characterized in that, The welding area (2) consists of multiple areas and is centrally symmetrically distributed on the outside of the axial hole (13).

8. The battery busbar according to any one of claims 1-7, characterized in that, The busbar also includes a current-drawing piece (3) for drawing out current, which is connected to the busbar body (1).

9. The battery busbar according to claim 8, characterized in that, The drain plate (3) also includes the welding area (2).

10. The battery busbar according to claim 9, characterized in that, The welding area (2) of the drain plate (3) and the welding area (2) of the second surface (12) are located on the same side or opposite side of the busbar.

11. The battery busbar according to claim 10, characterized in that, The drain plate (3) is connected to the busbar body (1) through a folded drain area, and the folded drain area is provided with a fusible area with reduced flow area.

12. The battery busbar according to claim 11, characterized in that, The folded drainage area includes a first folded area (31), a second folded area (32), and a connecting area (33). The first folded area (31) folds and connects the connecting area (33) and the drainage piece (3). The second folded area (32) folds and connects the connecting area (33) and the manifold body (1).

13. The battery busbar according to claim 12, characterized in that, The first folding region (31) and / or the second folding region (32) are provided with through holes (34), which extend to the portion adjacent to the first folding region (31) and / or the second folding region (32); When the folded drainage area is in a folded state, at least a portion of the through hole (34) overlaps axially with the axial hole (13) of the manifold body (1).

14. A battery, characterized in that, The battery includes a winding core (100) and a busbar (200) as described in any one of claims 1-13, wherein the busbar (200) is laser-welded to the end of the winding core (100).

15. The battery according to claim 14, characterized in that, Multiple solder joints (14) are formed on the busbar (200) by laser irradiation, and the multiple solder joints are discrete solder joints arranged in multiple rows.

16. The battery according to claim 14, characterized in that, Multiple solder joints (14) are formed on the busbar (200), and the multiple solder joints are continuous solder joints, forming a straight line, an S-shape or a U-shape.

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