CN116393827A

CN116393827A - Battery, electric equipment and laser welding method

Info

Publication number: CN116393827A
Application number: CN202310673685.5A
Authority: CN
Inventors: 陈文�; 刘亮平; 黄龙杰
Original assignee: Contemporary Amperex Technology Co Ltd
Current assignee: Contemporary Amperex Technology Co Ltd
Priority date: 2023-06-08
Filing date: 2023-06-08
Publication date: 2023-07-07

Abstract

The application discloses a battery, electric equipment and a laser welding method, and relates to the technical field of batteries. The battery includes a plurality of structural members joined to each other by laser welding and forming a joint region in the shape of a spiral, the number of the joint regions being a plurality. The technical scheme provided by the application can improve the reliability of the battery.

Description

Battery, electric equipment and laser welding method

Technical Field

The application relates to the technical field of battery manufacturing, in particular to a battery, electric equipment and a laser welding method.

Background

Energy conservation and emission reduction are key to sustainable development of the automobile industry, and electric vehicles become an important component of sustainable development of the automobile industry due to the energy conservation and environmental protection advantages of the electric vehicles. For electric vehicles, battery technology is an important factor related to development of the electric vehicles, and how to improve the reliability of the battery is a technical problem to be solved in battery technology.

At present, two welded structural members are welded by adopting a laser welding mode in a shape of a Chinese character 'hui', so that a Chinese character 'hui' type joint area can be formed between the two welded structural members. The laser welding mode in the shape of the Chinese character ' hui ' is that the laser scanning track is sequentially changed from the inner annular scanning track to the outer annular scanning track in the preset joint area on the two structural members ', on one hand, the welding mode can cause low welding efficiency due to extra time generated by the fact that laser irradiation is stopped when the inner ring is switched to the outer ring, on the other hand, because laser is not easy to control, in the process that the laser track moves from the inner ring to the outer ring, the condition that laser acts from the inner ring to the outer ring (namely, the condition that continuous welding exists), energy is accumulated, welding pool air holes are formed, welding quality is low, and the reliability of a battery is low.

Disclosure of Invention

The application provides a battery, electric equipment and a laser welding method.

The application is realized by the following technical scheme:

in a first aspect, some embodiments of the present application provide a battery comprising a plurality of structural members joined to one another by laser welding and forming a joined region, the joined region being spiral in shape, the number of joined regions being a plurality.

In the scheme, the spiral joint area (namely the spiral welding mark) is formed between the structural members through laser welding, so that compared with the welding mark in the shape of a Chinese character 'Hui', the extra time generated by stopping irradiation due to the fact that laser is switched from the inner ring to the outer ring is saved, the time required for welding is less, and the manufacturing efficiency of the battery can be improved; on the other hand, the problem of continuous welding caused by poor laser beam control in the process of switching laser from the inner ring to the outer ring can be solved, so that the structural members have higher welding quality, and the reliability of the battery is high; on the other hand, a plurality of joint areas are arranged between the structural members, so that the welding connection strength between the structural members is high, the stability is good, and the reliability of the battery is high.

According to some embodiments of the present application, a battery includes a plurality of battery cells, and a plurality of structural members includes a sampling member, a first electrical connector, and a second electrical connector. The plurality of battery cells are electrically connected through a plurality of first electrical connectors, and each first electrical connector is electrically connected with the sampling member through one second electrical connector. Wherein the sampling member and the second electrical connection member are bonded to each other by laser welding and form a bonding region; and/or the first electrical connector and the second electrical connector are bonded to each other by laser welding and form a bonding region.

In the scheme, compared with the welding printing in the shape of a Chinese character 'Hui', the welding time is shorter on one hand and the manufacturing efficiency of the battery can be improved because the welding time is shorter; on the other hand, the problem of continuous welding caused by poor laser beam control in the process of switching laser from the inner ring to the outer ring can be solved, so that the welding quality between the sampling piece and the second electric connecting piece or between the first electric connecting piece and the second electric connecting piece is higher, and the reliability of the battery is further high.

According to some embodiments of the present application, the battery comprises a battery cell. The battery cell includes a case and an electrode assembly disposed in the case. The case is provided with electrode terminals. The plurality of structural members includes tabs and electrode terminals of the electrode assembly. The tab of the electrode assembly is directly welded to the electrode terminal, and the tab and the electrode terminal are joined to each other by laser welding to form a joint region.

In the scheme, compared with the welding printing in the shape of a Chinese character 'Hui', the welding time is shorter in the spiral joint area (namely the welding printing in the shape of a spiral) formed between the tab and the electrode terminal, and the manufacturing efficiency of the battery can be improved; on the other hand, the problem of continuous welding caused by poor laser beam control in the process of switching laser from the inner ring to the outer ring can be solved, so that the electrode lug and the electrode terminal have higher welding quality, and the reliability of the battery is further high.

According to some embodiments of the present application, a battery includes a battery cell; the battery cell comprises a shell and an electrode assembly arranged in the shell; the shell is provided with an electrode terminal, and the electrode lug of the electrode assembly is electrically connected with the electrode terminal through the adapter. The plurality of structural members includes tabs of the electrode assembly, an adapter, and electrode terminals. The tab and the adapter are bonded with each other by laser welding to form a bonding area; and/or, the adaptor and the electrode terminal are joined to each other by laser welding and form a joint region.

In the scheme, compared with the welding printing in the shape of a Chinese character 'Hui', the welding time is shorter on one hand and the manufacturing efficiency of the battery can be improved because of the spiral joint area (namely the spiral welding printing) formed between the electrode lug and the electrode terminal or between the adapter and the electrode terminal; on the other hand, the problem of continuous welding caused by poor laser beam control in the process of switching laser from the inner ring to the outer ring can be solved, so that higher welding quality is achieved between the electrode lug and the electrode terminal or between the adapter and the electrode terminal, and further the reliability of the battery is high.

According to some embodiments of the present application, the structural member is sheet-like.

In the scheme, the structural members are sheet-shaped, namely, the thickness is smaller, spiral joint areas (namely, spiral welding marks) are formed among the sheet-shaped structural members, and compared with the welding marks in the shape of a Chinese character 'Hui', the time required for welding is smaller on one hand, so that the manufacturing efficiency of the battery can be improved; on the other hand, the problem of continuous welding caused by poor laser beam control in the process of switching laser from the inner ring to the outer ring can be solved, and the problem of low welding quality caused by the fact that the sheet structural member is penetrated by melting is solved.

According to some embodiments of the present application, the number of the bonding regions is n, n > 2m, m is an integer greater than or equal to 2, and the n bonding regions are arranged in a circular array.

In the scheme, the plurality of joint areas are arranged in the annular array, so that on one hand, the welding strength can be improved, and the static load capacity of the battery can be improved; on the other hand, the risk that laser energy is gathered at the centers of a plurality of joint areas can be effectively reduced, the risk that welding quality is low due to the fact that welding is conducted to the welding slurry protrusion to oxidize and blacken caused by energy gathering is reduced, and the battery has higher reliability.

According to some embodiments of the present application, the minimum distance between two adjacent joint regions is P, and the minimum distance from the innermost end to the outermost end of the joint region is R, satisfying 2 R.ltoreq.P.ltoreq.4R.

In the above scheme, by limiting the relative relation between the distance P between two joint areas and the radius R of the joint areas, the distance P between two adjacent joint areas is not less than 2R and not more than 4R, so that on one hand, the welding connection strength can be improved, the requirements of dynamic and static load capacity of a shearing force and stripping force test are met, on the other hand, the risk of low welding quality caused by continuous welding can be reduced, the welding quality between structural members is improved, and the battery has higher reliability.

In a second aspect, some embodiments of the present application further provide a powered device, including a battery provided in any one of the second aspects, the battery being configured to provide electrical energy.

In a third aspect, the present application also provides a laser welding method of irradiating laser light toward a plurality of structural members to be welded, which are stacked, and forming a joining region at the plurality of structural members to be welded by scanning of the laser light, so that the plurality of structural members are joined to each other; the laser welding method comprises the following steps: a plurality of structural members to be welded are laser scanned in a spiral trajectory to form a joint region. And n joint areas are formed on the structural members to be welded through scanning of the laser, and are mutually arranged at intervals, wherein n is more than or equal to 2. Compared with the scheme that the laser welding track is the inner circular ring and the outer circular ring, the scheme has the advantages that the laser scanning track is in the spiral shape, so that extra time generated by stopping irradiation due to the fact that the laser is switched from the inner ring to the outer ring can be saved; on the other hand, the problems of accumulated laser energy, formation of welding pool air holes and low welding quality caused by continuous welding caused by poor laser beam control in the process of switching laser from the inner ring to the outer ring can be solved. The laser welding method provided by the invention can be applied to welding between structural members in a battery, for example, the second electric connector and the first electric connector in the battery are welded by the laser welding method provided by the invention, and therefore, the second electric connector and the first electric connector are welded by the laser welding method provided by the invention, so that the second electric connector and the first electric connector have higher welding quality, and the battery has higher reliability. Meanwhile, in order for the welding shear force and the peeling force to reach the preset standards, it is necessary to ensure a welding melt volume of a sufficient volume size. I.e. without welding the penetration member, a sufficient welding area is required. In the scheme, n joint areas are formed and are arranged at intervals, so that the total welding area meets the requirement, and the welding shearing force and the stripping force meet the preset standard; on the other hand, the joint areas are arranged at intervals, so that the risk of low welding quality caused by oxidation blackening of the molten paste bulge due to energy aggregation caused by welding is reduced; on the other hand, each joint area is formed by independent welding and is not affected by each other, so that the probability of false welding can be effectively reduced, the welding quality between structural members is high, and the reliability of the battery is high.

According to some embodiments of the present application, laser scanning a plurality of structural members to be welded in a spiral trajectory to form a joint region includes: a plurality of structural members to be welded are laser scanned in a spiral trajectory from inside to outside to form a joint region. Or, a plurality of structural members to be welded are subjected to laser scanning in a spiral track from outside to inside to form a joint region.

In the above-mentioned scheme, the scanning of the laser from inside to outside is understood to be that the scanning start end of the laser is the innermost end of the final spiral bonding area (i.e. solder printing), and the scanning end of the laser is the outermost end of the final spiral bonding area (i.e. solder printing). In the process of scanning from inside to outside, the part of the structural member, which is scanned first (namely the part close to the inner side of the joint region), is cooled first, and the temperature is reduced, so that the risk that laser energy is accumulated in the center of the joint region, and the structural member is melted through is reduced, the welding quality is improved, and the reliability of the battery is improved. The scanning of the laser from outside to inside is understood to mean that the scanning start of the laser is the outermost end of the final spiral weld, and the scanning end of the laser is the innermost end of the final spiral weld. According to the scheme, the scanning sequence of the laser scanning tracks is set from outside to inside, so that the selection scheme of the laser scanning tracks can be increased, and the feasibility of the laser welding method is improved.

According to some embodiments of the present application, the scan trajectory of the laser is curved.

In the scheme, compared with the laser scanning track which is a spiral shape formed by a plurality of straight line segments, the laser scanning track is set to be a curve, so that energy accumulation of the laser at the corner position can be effectively reduced, a welding pool air hole is formed, molten slurry overflows, welding is high in surplus and outstanding, the appearance is abnormal, and the risk of low welding quality is caused, so that the welding quality can be effectively improved, and the reliability of a battery can be further improved.

According to some embodiments of the present application, the scanning trajectory of the laser is spiral with equal spiral pitch.

In the scheme, the scanning track of the laser is set to be spiral with equal spiral spacing, so that a uniform molten pool can be formed on the structural member, the risk of energy accumulation is reduced, the uniformity of the surface appearance of the structural member is good, the welding quality is high, and the reliability of the battery is high.

According to some embodiments of the application, the spiral pitch of the scanning track of the laser is L, the diameter of the light spot of the laser is D, and 0.5 D.ltoreq.L.ltoreq.2D is satisfied.

The screw pitch is too large, so that the virtual welding is caused, the welding quality is low, and the shearing force and the stripping force can not meet the capability requirement of dynamic and static loads. If the screw pitch is too small, energy accumulation exists, the risk of penetration exists, the welding quality is low, and the shearing force and the stripping force test can not meet the capability requirement of dynamic and static loads. Therefore, in the above scheme, under the condition that the diameter D of the light spot of the laser is fixed, by limiting the relative relation between the spiral distance L and the diameter D of the light spot of the laser, the spiral distance L is not less than 0.5D and not more than 2D, so that the welding quality can be effectively improved, the requirements of dynamic and static load capacity of the shear force and stripping force test are met, and further, the battery has higher reliability.

According to some embodiments of the present application, n bonding regions are formed on a plurality of structural members to be welded by scanning a laser, the n bonding regions being disposed at intervals from each other, including:

the laser scans in a region to be welded to form a joint region, and the laser emitting device does not emit laser in the process of switching from the joint region to the region to be welded.

In the scheme, the laser emission device is controlled not to emit laser in the process of switching from one joint area to one area to be welded, so that energy accumulation caused by continuous welding due to the fact that laser is not easy to control can be effectively reduced, welding pool air holes are formed, and the risk of affecting welding quality is reduced, so that good welding quality is achieved between structural members, and further the battery is high in reliability.

According to some embodiments of the present application, n bonding regions are formed on a plurality of structural members to be welded by scanning a laser, the n bonding regions being disposed at intervals from each other, including: the n joint areas are arranged in a ring-shaped array, n is more than or equal to 2m, and m is an integer more than or equal to 2.

In the scheme, the plurality of joint areas are arranged in the annular array, so that on one hand, the welding strength can be improved, and the static load capacity of a product can be improved; on the other hand, the risk that laser energy is gathered at the centers of a plurality of joint areas can be effectively reduced, and the risk that welding quality is low due to oxidation blackening of the molten paste bulge caused by energy gathering caused by welding is reduced.

According to some embodiments of the present application, n bonding regions are formed on a plurality of structural members to be welded by scanning a laser, and the n bonding regions are disposed at intervals, and further include: the n bonding areas comprise m bonding areas, and the central connecting line of two bonding areas in each bonding area passes through the center of the annular array; the 1 st to m-th bonding regions are sequentially formed.

In the above-described aspect, among the plurality of joint regions arranged in the annular array, there are a plurality of pairs of joint regions, a center line of two joint regions of each pair passing through a center of the annular array, a distance value (minimum pitch) between the two joint regions being a maximum value of distance values of any two joint regions among the plurality of joint regions arranged in the annular array; this step provides a welding sequence of the joint regions, which may be referred to as a diagonal welding sequence, i.e., the joint regions may be formed sequentially in a diagonal welding sequence with respect to the center of the annular array, it being understood that welding is performed in units of pairs, for example, one of each pair of joint regions is welded first, and then the other joint region of each pair of joint regions is welded; and then the other pairs of joint regions are welded. The distance value between the two joint areas in each pair is the maximum value of the distance values of any two joint areas in a plurality of joint areas distributed in an annular array, so that the welding can be performed according to the diagonal welding sequence about the center of the annular array, on one hand, the energy accumulation can be effectively reduced, a welding pool air hole is formed, the molten paste overflows, the welding surplus is high, the appearance is abnormal, and the risk of low welding quality is caused, so that the welding quality between structural members is high, and the reliability of a battery is further improved; on the other hand, as the distance between the two joint areas in each pair is far, the risk of continuous welding between the two joint areas is low, and after welding of one joint area is completed, the laser emitting device can be quickly switched to the other area to be welded.

In the scheme, if the minimum distance between two adjacent joint areas is too large, the interdependence effect of the two adjacent joint areas is too small, and the requirements of dynamic and static load capacity of a shearing force and stripping force test cannot be met; the distance between two adjacent joint areas is too small, so that risks of continuous welding and laser energy accumulation exist and the welding quality is influenced, and therefore, the distance between the two adjacent joint areas is not smaller than 2R and not larger than 4R by limiting the relative relation between the minimum distance P between the two joint areas and the minimum distance R between the innermost end part and the outermost end part of the joint areas, on one hand, the connection strength of welding can be improved, the requirements of dynamic and static load capacity of a shearing force and stripping force test are met, on the other hand, the risk that the welding quality is low due to continuous welding can be reduced, and therefore the welding quality between structural parts is improved, and the battery has higher reliability.

Additional aspects and advantages of the application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the application.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered limiting the scope, and that other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic illustration of a vehicle in some embodiments of the present application;

FIG. 2 is an exploded perspective view of a battery provided in some embodiments of the present application;

FIG. 3 is a schematic view of a first electrical connector and a second electrical connector according to some embodiments of the present application;

FIG. 4 is an exploded schematic view of a battery cell according to some embodiments of the present application;

FIG. 5 is a schematic block flow diagram of a laser welding method provided in some embodiments of the present application;

FIG. 6 is a schematic illustration of a spiral trace in some embodiments of the present application;

FIG. 7 is a schematic view of a spiral track in further embodiments of the present application;

FIG. 8 is a schematic view of a spiral track in accordance with other embodiments of the present application;

FIG. 9 is a schematic block diagram of the flow of step S2 in some embodiments of the present application;

FIG. 10 is a schematic view of n bonding regions arranged in a circular array according to some embodiments of the present application;

fig. 11 is a schematic block flow diagram of step S2 in some embodiments of the present application.

Icon: 30-structural part; 31-a second electrical connection; 32-a first electrical connection; 40-junction region; 400-straight line segment; 41-a first junction region; 42-a second junction region; 43-third junction region; 44-a fourth junction region; 45-fifth junction region; 46-sixth junction region; 1000-vehicle; 100-cell; 200-a controller; 300-motor; 20-a box body; 21-an upper box body; 22-lower box body; 10-battery cell; 11-a housing; 110-a housing; 111-end caps; 12-an electrode assembly; 120-electrode lugs; 13-electrode terminals; 14-an adapter; 2000-laser welding method.

Detailed Description

For the purposes of making the objects, technical solutions and advantages of the embodiments of the present application more apparent, the technical solutions in the embodiments of the present application will be clearly described below with reference to the drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be made by one of ordinary skill in the art based on the embodiments herein without making any inventive effort, are intended to be within the scope of the present application.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "comprising" and "having" and any variations thereof in the description and claims of the present application and in the description of the figures above are intended to cover non-exclusive inclusions. The terms first, second and the like in the description and in the claims or in the above-described figures, are used for distinguishing between different objects and not necessarily for describing a particular sequential or chronological order.

Reference in the specification to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments.

In the description of the present application, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "attached" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the terms in this application will be understood by those of ordinary skill in the art as the case may be.

The term "and/or" in this application is merely an association relation describing an associated object, and indicates that three relations may exist, for example, a and/or B may indicate: a exists alone, A and B exist together, and B exists alone. In this application, the character "/" generally indicates that the associated object is an or relationship.

In the embodiments of the present application, the same reference numerals denote the same components, and in the interest of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, etc. dimensions of the various components in the embodiments of the present application, as well as the overall thickness, length, width, etc. dimensions of the integrated device, are illustrative only and should not be construed as limiting the present application in any way.

The term "plurality" as used herein refers to more than two (including two).

In the present application, the battery cells may include lithium ion secondary battery cells, lithium ion primary battery cells, lithium sulfur battery cells, sodium lithium ion battery cells, sodium ion battery cells, or magnesium ion battery cells, and the embodiment of the present application is not limited thereto. The battery cells may be cylindrical, flat, rectangular, or otherwise shaped, as well as the embodiments herein are not limited in this regard.

Reference to a battery in embodiments of the present application refers to a single physical module that includes one or more battery cells to provide higher voltage and capacity. The battery generally includes a case for enclosing one or more battery cells. The case body can prevent liquid or other foreign matters from affecting the charge or discharge of the battery cells.

The battery cell comprises an electrode assembly and electrolyte, wherein the electrode assembly consists of a positive electrode plate, a negative electrode plate and a diaphragm. The battery cell mainly relies on metal ions to move between the positive pole piece and the negative pole piece to work. The positive electrode plate comprises a positive electrode current collector and a positive electrode active material layer, wherein the positive electrode active material layer is coated on the surface of the positive electrode current collector, the positive electrode current collector without the positive electrode active material layer protrudes out of the positive electrode current collector coated with the positive electrode active material layer, and the positive electrode current collector without the positive electrode active material layer is used as a positive electrode lug. Taking a lithium ion battery as an example, the material of the positive electrode current collector may be aluminum, and the positive electrode active material may be lithium cobaltate, lithium iron phosphate, ternary lithium, lithium manganate or the like. The negative electrode plate comprises a negative electrode current collector and a negative electrode active material layer, wherein the negative electrode active material layer is coated on the surface of the negative electrode current collector, the negative electrode current collector without the negative electrode active material layer protrudes out of the negative electrode current collector coated with the negative electrode active material layer, and the negative electrode current collector without the negative electrode active material layer is used as a negative electrode lug. The material of the negative electrode current collector may be copper, and the negative electrode active material may be carbon, silicon, or the like. The separator may be made of PP (polypropylene) or PE (polyethylene).

The battery includes sampling piece, second electric connecting piece and first electric connecting piece, and the second electric connecting piece is connected with the battery monomer in the battery through first electric connecting piece, and sampling piece is connected with the second electric connecting piece for gather battery monomer's status signal, for example voltage signal, temperature signal etc.. The sampling member may be connected with a battery management system (BMS, battery Management System) of the battery to transmit a status signal to the battery management system. In some embodiments, the sampling member may be a flexible circuit board (FPC), and the second electrical connector is typically soldered to the sampling member and the second electrical connector is typically soldered to the first electrical connector. In some embodiments, the first electrical connection may be a tab in the battery for connection to an electrode terminal of the battery cell, also referred to as a post. The second electrical connector may be a nickel plate on a harness isolation plate in the battery, and the second electrical connector may be connected, for example welded, with a sampling member on the harness isolation plate.

The development of battery technology is taking into consideration various design factors such as energy density, cycle life, discharge capacity, charge-discharge rate and other performance parameters, and the reliability of the battery.

In the battery, electrical connection of many structures is achieved by means of welding, for example, between a tab and an adapter, between an adapter and an electrode terminal, between a tab and a nickel plate, between a nickel plate and a sampling member, etc. However, at present, there is a risk that the two mutually welded structural members are easily separated, so that signals cannot be transmitted, and corresponding management measures cannot be taken by the battery.

In view of this, in order to improve the problem of low welding quality between two welded structural members, resulting in low reliability of the battery, some embodiments of the present application provide a battery including a plurality of structural members that are joined to each other by laser welding and form a joining region that is spiral.

In the scheme, the spiral joint area (namely the spiral welding mark) is formed between the two structural members through laser welding, so that compared with the welding mark in the shape of a Chinese character 'Hui', the extra time generated by stopping irradiation due to the fact that laser is switched from the inner ring to the outer ring is saved, the time required for welding is less, and the manufacturing efficiency of the battery can be improved; on the other hand, the problem of continuous welding caused by poor laser beam control in the process of switching laser from the inner ring to the outer ring can be solved, so that the structural members have higher welding quality, namely the structural members connected by welding in the battery have higher welding quality, and the reliability of the battery is further high.

The technical scheme described by the embodiment of the application is suitable for the battery and the electric equipment using the battery. The technical scheme described in the embodiment of the application is not only suitable for welding between structural members which are connected together in a welding mode in a battery, for example, welding between a second electric connecting piece and a first electric connecting piece, welding between a second electric connecting piece and a sampling piece, welding between a tab and an electrode terminal bracket, welding between a tab and an adapter piece or welding of other components in the battery, but also suitable for welding of other metal or nonmetal structural members.

The electric equipment can be vehicles, mobile phones, portable equipment, notebook computers, ships, spacecrafts, electric toys, electric tools and the like. Spacecraft including airplanes, rockets, space planes, spacecraft, and the like; the electric toy includes fixed or mobile electric toys, such as a game machine, an electric car toy, an electric ship toy, and an electric airplane toy; power tools include metal cutting power tools, grinding power tools, assembly power tools, and railroad power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete shakers, and electric planers, among others. The embodiment of the application does not limit the electric equipment in particular.

For convenience of explanation, the following embodiments take electric equipment as an example of a vehicle.

Referring to fig. 1, fig. 1 is a schematic diagram of a vehicle 1000 according to some embodiments of the present application. The vehicle 1000 may be a fuel oil vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or a range-extended vehicle. The battery 100 is provided in the interior of the vehicle 1000, and the battery 100 may be provided at the bottom or the head or the tail of the vehicle 1000. The battery 100 may be used for power supply of the vehicle 1000, for example, the battery 100 may be used as an operating power source of the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300, the controller 200 being configured to control the battery 100 to power the motor 300, for example, for operating power requirements during start-up, navigation, and travel of the vehicle 1000.

In some embodiments of the present application, battery 100 may not only serve as an operating power source for vehicle 1000, but may also serve as a driving power source for vehicle 1000, instead of or in part instead of fuel oil or natural gas, to provide driving power for vehicle 1000.

Referring to fig. 2, fig. 2 is an exploded perspective view of a battery 100 according to some embodiments of the present application. The battery 100 includes a case 20 and a battery cell 10, and the battery cell 10 is accommodated in the case 20. The case 20 is used to provide an accommodating space for the battery cell 10, and the case 20 may have various structures. In some embodiments, the case 20 may include an upper case 21 and a lower case 22, the upper case 21 and the lower case 22 being overlapped with each other, the upper case 21 and the lower case 22 together defining an accommodating space for accommodating the battery cell 10. The lower case 22 may have a hollow structure with one end opened, the upper case 21 may have a plate-shaped structure, and the upper case 21 covers the opening side of the lower case 22, so that the upper case 21 and the lower case 22 together define an accommodating space; the upper case 21 and the lower case 22 may be hollow structures each having one side opened, and the opening side of the upper case 21 may be closed to the opening side of the lower case 22. Of course, the case 20 formed by the upper case 21 and the lower case 22 may be of various shapes, such as a cylinder, a rectangular parallelepiped, etc.

In the battery 100, the number of the battery cells 10 may be plural, and the plural battery cells 10 may be connected in series, parallel, or series-parallel, and series-parallel refers to both of the plural battery cells 10 being connected in series and parallel. The plurality of battery cells 10 can be directly connected in series or in parallel or in series-parallel, and then the whole formed by the plurality of battery cells 10 is accommodated in the box body 20; of course, the battery 100 may also be a battery module formed by connecting a plurality of battery cells 10 in series or parallel or series-parallel connection, and a plurality of battery modules are then connected in series or parallel or series-parallel connection to form a whole and are accommodated in the case 20. The battery 100 may also include other structures, for example, the battery 100 may also include a first electrical connection for making electrical connection between the plurality of battery cells 10. The first electrical connector may be connected with a second electrical connector, the second electrical connector may be connected with a sampling member of the battery, and the sampling member may be connected with a battery management system.

Wherein each battery cell 10 may be a secondary battery cell or a primary battery cell; but not limited to, lithium sulfur battery cells, sodium ion battery cells, or magnesium ion battery cells.

Referring to fig. 3, fig. 3 is a schematic diagram of a first electrical connector 32 and a second electrical connector 31 according to some embodiments of the present application.

The first electrical connector 32 and the second electrical connector 31 are bonded to each other by laser welding as a unit and form a bonding region 40. The bonding areas 40 formed on the first electrical connector 32 and the second electrical connector 31 by laser welding can be seen in fig. 3. In some embodiments, the bonding region 40 may be a weld mark formed by welding.

According to some embodiments of the present application, there is provided a battery including a plurality of structural members 30, the plurality of structural members 30 being joined to each other by laser welding and forming a joining region 40, the joining region 40 being in a spiral shape (see the joining region 40 shown in fig. 3). The number of the joint regions 40 is plural.

The plurality of structural members 30 may refer to two or more number of components that are interconnected together by laser action. In some embodiments, the plurality of structural members 30 may be a second electrical connector and a first electrical connector in the battery; or may be a sample member and a second electrical connection member in the battery; or may be tabs and adaptors of an electrode assembly in a battery; or may be an adapter and electrode terminal in a battery; or may be tabs and electrode terminals in the battery.

In some embodiments, a plurality of structural members 30 are arranged in a stack, joined to one another by laser welding and forming a joint region 40. In some implementations, the bonding region 40 may be a weld mark formed by welding. By "the joining region 40 is helical" it is meant that the joining region 40 formed by the laser acting on the structural member is a continuous line segment, and the line segment may be centered about a point about which it extends from the inside to the outside.

In some embodiments, the plurality of structural members 30 are welded a plurality of times such that at least two joined areas are formed on the plurality of structural members 30. For example, the second electrical connector 31 and the first electrical connector 32 are soldered a plurality of times such that at least two bonding areas 40 are formed on the second electrical connector 31 and the first electrical connector 32. Each of the engagement areas 40 is independent of and spaced apart from each other.

In the above-mentioned scheme, the spiral joint area 40 (i.e. spiral welding) between the structural members 30 saves extra time generated by stopping irradiation due to switching of the laser from the inner ring to the outer ring on the one hand, so that the welding time is smaller, and the manufacturing efficiency of the battery can be improved; on the other hand, the problem of continuous welding caused by poor laser beam control in the process of switching laser from the inner ring to the outer ring can be solved, so that the structural members have higher welding quality, and the reliability of the battery is high.

In order for the welding shear force and the peel force to meet the preset criteria, it is necessary to ensure a welding melt volume of sufficient volume. I.e. without welding the penetration member, a sufficient welding area is required. In some embodiments, the test method of the welding shear force and the peel force may be a conventional test method of the shear force and the peel force. For example, the peel force is the force required to peel a material from a standard test panel at an angle and speed under certain conditions, and is measured by a peel tester. Shear force may refer to a force exerted by two directions on a workpiece that has been welded such that the mutually welded workpieces are relatively displaced along the respective force directions, which may be measured by a shear force tester.

In the above-mentioned scheme, by forming the plurality of bonding areas 40 and arranging the plurality of bonding areas 40 at intervals, on one hand, the total welding area meets the requirement, and the welding shearing force and the peeling force meet the preset standard; on the other hand, the joint areas 40 are arranged at intervals, so that the risk of low welding quality caused by oxidation blackening of the molten paste bulge due to energy aggregation caused by welding is reduced; on the other hand, each joint region 40 is formed by welding independently, is not affected by each other, and can effectively reduce the probability of cold joint, so that the welding quality between structural members is high, and the reliability of the battery is high; on the other hand, a plurality of joint areas are arranged between the structural members, so that the welding connection strength between the structural members is high, the stability is good, and the reliability of the battery is high

According to some embodiments of the present application, the battery comprises a plurality of battery cells. The structural member 30 includes a sample member (not shown in fig. 3), a second electrical connector 31, and a first electrical connector 32. The plurality of battery cells are electrically connected by a plurality of first electrical connectors 32, each first electrical connector 32 being electrically connected to the sampling member by a second electrical connector 31. Wherein the sample piece and the second electrical connector 31 are bonded to each other by laser welding and form a bonding region 40. And/or the first electrical connector 32 and the second electrical connector 31 are joined to each other by laser welding and form the joint region 40. The second electrical connector 31 and the first electrical connector 32 may be referred to in fig. 3, and the battery cell may be referred to in fig. 2.

In some embodiments, the sampling member may be a flexible circuit board of the battery, which may be disposed on the beam isolation plate. The second electrical connector 31 may be a nickel plate disposed on the flexible circuit board. The first electrical connector 32 may be a tab connected to an electrode terminal of a battery cell. In some embodiments, the first electrical connector 32 connects electrode terminals of two battery cells. In some embodiments, the second electrical connector 31 and the first electrical connector 32 may be connected by laser welding and the joint region 40 formed by the welding may be spiral. In some embodiments, the sample piece and the second electrical connector 31 are connected by laser welding and the weld-formed joint area 40 is spiral.

In the above-mentioned scheme, the spiral bonding area 40 (i.e. spiral welding) formed between the sampling member and the second electrical connector 31 or between the second electrical connector 31 and the first electrical connector 32 has smaller time for welding compared with the welding with the shape of a Chinese character 'hui', so that the manufacturing efficiency of the battery can be improved; on the other hand, the problem of continuous welding caused by poor laser beam control in the process of switching laser from the inner ring to the outer ring can be solved, so that the second electric connecting piece 31 and the first electric connecting piece 32 or the sampling piece and the second electric connecting piece 31 have higher welding quality, and the reliability of the battery is high.

Referring to fig. 4, fig. 4 is an exploded view of a battery cell according to some embodiments of the present application. The battery includes a battery cell 10. The battery cell 10 includes a case 11 and an electrode assembly 12 disposed within the case 11. The case 11 is provided with electrode terminals 13. The plurality of structural members 30 include tabs 120 and electrode terminals 13 of the electrode assembly 12. The tab 120 of the electrode assembly 12 is directly welded to the electrode terminal 13, and the tab 120 and the electrode terminal 13 are joined to each other by laser welding and form a joint region 40 (the joint region 40 is not shown in fig. 4).

In some embodiments, the case 11 includes a case 110 and an end cap 111, the electrode assembly 12 is disposed within the case 110, and the end cap 111 closes the opening of the case 110 such that the electrode assembly 12 is in a closed chamber. The electrode terminal 13 is disposed on the end cap 111.

In the above-mentioned scheme, the spiral bonding area 40 (i.e., spiral welding) formed between the tab 120 and the electrode terminal 13 has smaller welding time than the welding with the shape of a Chinese character 'hui', so that the manufacturing efficiency of the battery can be improved; on the other hand, the problem of continuous welding caused by poor laser beam control in the process of switching laser from the inner ring to the outer ring can be solved, so that the electrode lug 120 and the electrode terminal 13 have higher welding quality, and the reliability of the battery is high.

According to further embodiments of the present application, referring to fig. 4, a battery includes a battery cell 10. The battery cell 10 includes a case 11 and an electrode assembly 12 disposed within the case 11. The case 11 is provided with an electrode terminal 13, and the tab 120 of the electrode assembly 12 is electrically connected to the electrode terminal 13 through the adapter 14. The plurality of structural members 30 includes tabs 120 of the electrode assembly 12, the adapter 14, and the electrode terminals 13. The tab 120 and the adapter 14 are bonded to each other by laser welding and form a bonding region 40 (the bonding region 40 is not shown in fig. 4); and/or the adapter 14 and the electrode terminal 13 are joined to each other by laser welding and form a joint region (the joint region 40 is not shown in fig. 4).

In some embodiments, the adapter 14 has a sheet shape, and the tab 120 is connected to the electrode terminal 13 through the adapter 14.

In the above-mentioned scheme, the spiral bonding area 40 (i.e. spiral welding) formed between the tab 120 and the electrode terminal 13 or between the adaptor 14 and the electrode terminal 13 has smaller time for welding compared with the welding with the shape of a Chinese character 'hui', so that the manufacturing efficiency of the battery can be improved; on the other hand, the problem of continuous welding caused by poor laser beam control in the process of switching laser from the inner ring to the outer ring can be solved, so that the electrode lug 120 and the electrode terminal 13 or the adapter 14 and the electrode terminal 13 have higher welding quality, and the reliability of the battery is further high.

According to some embodiments of the present application, the structural member 30 is sheet-like.

The sheet form of the structural member may refer to a smaller thickness of the structural member 30. The plurality of structural members 30 may be stacked in the thickness direction of the structural members 30, and then laser-welded.

In the above scheme, the structural member 30 is sheet-shaped, i.e. the thickness is smaller, the spiral joint area 40 (i.e. the spiral welding) is formed between the sheet-shaped structural members 30, and compared with the welding with the shape of a Chinese character 'hui', the time required for welding is smaller on one hand, so that the manufacturing efficiency of the battery can be improved; on the other hand, the problem of continuous welding caused by poor laser beam control in the process of switching laser from the inner ring to the outer ring can be solved, and the problem of low welding quality caused by the fact that the sheet structural member is penetrated by melting is solved.

According to some embodiments of the present application, referring to fig. 3, the number of engagement regions 40 is a plurality.

In some embodiments, the plurality of structural members 30 are welded a plurality of times such that at least two joined areas are formed on the plurality of structural members 30. For example, the second electrical connector 31 and the first electrical connector 32 are soldered a plurality of times such that at least two bonding areas 40 are formed on the second electrical connector 31 and the first electrical connector 32.

In the above scheme, a plurality of joint areas 40 are arranged among a plurality of structural members 30, so that the welding connection strength among the structural members 30 is high, the stability is good, and the reliability of the battery is high.

Please refer to fig. 3 in combination with fig. 10, according to some embodiments of the present application. The number of the bonding regions 40 is n, n > 2m, m is an integer of 2 or more, and the n bonding regions 40 are arranged in a ring-shaped array.

In the above scheme, by arranging the plurality of joint areas 40 and arranging the plurality of joint areas 40 in a ring-shaped array, on one hand, the welding strength can be increased, and the static load capacity of the battery can be improved; on the other hand, the risk that laser energy is concentrated in the centers of the plurality of joint areas 40 can be effectively reduced, the risk that welding quality is low due to the fact that the molten paste bulges are oxidized and blacken due to energy concentration caused by welding is reduced, and the battery has higher reliability.

In some embodiments, the minimum distance from the innermost end to the outermost end of the engagement region 40 may be the radius R of the engagement region 40 in a spiral shape. For example, in fig. 6, the minimum distance from the innermost end to the outermost end of the joint region 40 may be the distance from the reference numeral a to the reference numeral B. In some embodiments, the minimum distance R from the innermost end to the outermost end of the engagement region 40 may be measured by a distance scanner or vernier caliper.

In some embodiments, the minimum distance P between two adjacent engagement regions 40 may be 2R, 2.5R, 3R, 3.5R, or 4R, or any of the two adjacent values. In some embodiments, the minimum distance P between two adjacent engagement regions 40 may be measured by a distance scanner or vernier caliper.

In the above-mentioned scheme, by defining the relative relationship between the distance P between two joint regions 40 and the radius R of the joint region 40, the distance P between two adjacent joint regions 40 is not less than 2R and not more than 4R, so that on one hand, the connection strength of welding can be improved, the requirements of dynamic and static loads in the test of shearing force and stripping force can be met, and on the other hand, the risk of low welding quality caused by continuous welding can be reduced, thereby improving the welding quality between structural members, and making the battery have higher reliability.

There is also provided, in accordance with some embodiments of the present application, a powered device including a battery as provided above, the battery being configured to provide electrical energy.

Referring to fig. 3 and 5, fig. 5 is a schematic block flow diagram of a laser welding method 2000 according to some embodiments of the present application. In the laser welding method 2000, laser light is irradiated toward a plurality of structural members to be welded, which are stacked, and a joining region 40 is formed on the structural members to be welded by scanning of the laser light so that the plurality of structural members are joined to each other. The laser welding method 2000 includes the following steps:

s1, carrying out laser scanning on a plurality of structural members to be welded in a spiral track to form a joint area 40.

S2, forming n joint areas 40 (as shown in FIG. 10) on the structural members to be welded through scanning of laser, wherein the n joint areas 40 are mutually spaced, and n is more than or equal to 2.

In some embodiments of the present application, the plurality of structural members to be welded are illustrated by taking the second electrical connector 31 of the battery and the first electrical connector 32 of the battery as examples.

"laser scanning a plurality of structural members to be welded in a spiral trajectory to form the joining region 40" may mean that a laser emitting device (e.g., a laser head) irradiates laser to the structural members and scans the structural members in a spiral trajectory so that the structural members are joined together due to energy melting generated by the laser and form the spiral joining region 40.

Referring to fig. 6, fig. 6 is a schematic diagram of a spiral track according to some embodiments of the present application. The spiral track may refer to a continuous line segment of the scan track of the laser light on the structure, and the line segment may be centered about a point about which it extends from inside to outside.

n may be an integer of 2 or more, for example, 2, 3, 4, 5, or 6, etc. The "n bonding regions 40 are disposed at a distance from each other" may be understood as that two adjacent bonding regions 40 are spaced from each other, that is, each bonding region 40 is not overlapped with a certain distance, and may be understood as that each bonding region 40 is independent from each other.

Compared with the scheme that the laser welding track is an inner circular ring and an outer circular ring, the scheme can save extra time generated by stopping irradiation due to the fact that the laser is switched from the inner ring to the outer ring by setting the laser scanning track to be spiral; on the other hand, the problems of accumulated laser energy, formation of welding pool air holes and low welding quality caused by continuous welding caused by poor laser beam control in the process of switching laser from the inner ring to the outer ring can be solved. Therefore, the second electrical connector and the first electrical connector are welded by the laser welding method 2000, so that the second electrical connector and the first electrical connector have higher welding quality, and the battery has higher reliability.

Meanwhile, in order for the welding shear force and the peeling force to reach the preset standards, it is necessary to ensure a welding melt volume of a sufficient volume size. I.e. without welding the penetration member, a sufficient welding area is required. In some embodiments, the test method of the welding shear force and the peel force may be a conventional test method of the shear force and the peel force. For example, the peel force is the force required to peel a material from a standard test panel at an angle and speed under certain conditions, and is measured by a peel tester. Shear force may refer to a force exerted by two directions on a workpiece that has been welded such that the mutually welded workpieces are relatively displaced along the respective force directions, which may be measured by a shear force tester.

In the above scheme, n bonding areas 40 are formed, and the n bonding areas 40 are arranged at intervals, so that on one hand, the total welding area meets the requirement, and the welding shearing force and the stripping force meet the preset standard; on the other hand, the joint areas 40 are arranged at intervals, so that the risk of low welding quality caused by oxidation blackening of the molten paste bulge due to energy aggregation caused by welding is reduced; on the other hand, each of the bonding regions 40 is formed by welding independently, and is not affected by each other, so that the probability of cold joint can be effectively reduced, thereby enabling high welding quality between structural members and thus high battery reliability.

According to some embodiments of the present application, step S1 of laser scanning a plurality of structural members to be welded in a spiral trajectory to form a joint region 40 includes: a plurality of structural members to be welded are laser scanned in an inside-out spiral trajectory to form the joining region 40. Or, a plurality of structural members to be welded are laser scanned in an outside-in spiral trajectory to form the joining region 40.

Referring to fig. 6, the direction of laser scanning is shown by the arrow in fig. 6. In fig. 6, the start of scanning of the laser light is indicated by an arrow "a", and the end of scanning of the laser light is indicated by an arrow "B".

The scanning of the laser from the inside to the outside is understood to mean that the scanning start of the laser is the innermost end of the final spiral-shaped joining region 40 (i.e. the solder mark) and the scanning end of the laser is the outermost end of the final spiral-shaped joining region 40 (i.e. the solder mark). The laser light continuously acts on the structural member from the scanning start end to the scanning end according to a spiral track.

In the above scheme, during the process of scanning from inside to outside, the part of the structural member, which is scanned first (i.e., the part close to the inner side of the joint region 40), will be cooled first, and the temperature is reduced, so that the accumulation of laser energy in the center of the joint region 40 is reduced, the risk that the structural member is melted through is reduced, the welding quality is improved, and the reliability of the battery can be improved.

Referring to fig. 7, fig. 7 is a schematic diagram of a spiral track according to other embodiments of the present application. The direction of laser scanning is shown with an arrow in fig. 7. In fig. 7, the start of scanning of the laser light is indicated by an arrow labeled "C", and the end of scanning of the laser light is indicated by an arrow labeled "D".

The scanning of the laser from outside to inside is understood to mean that the scanning start of the laser is the outermost end of the final spiral weld, and the scanning end of the laser is the innermost end of the final spiral weld. The laser light continuously acts on the structural member from the scanning start end to the scanning end according to a spiral track.

In the above scheme, the scanning sequence of the laser scanning tracks is set from outside to inside, so that the selection scheme of the laser scanning tracks can be increased, and the feasibility of the laser welding method 2000 is improved.

In some embodiments, the scan trajectory of the laser is a spiral formed by a continuous curve. For ease of understanding, in other embodiments, please refer to fig. 8, fig. 8 is a schematic diagram of a spiral track in other embodiments of the present application, where the laser scanning track may be a spiral formed by a plurality of straight line segments 400 connected to each other. It can be seen in fig. 8 that there is a corner location between each two straight line segments 400, which when acted upon by the laser light, causes energy to accumulate between the two straight line segments 400, affecting the weld quality.

In the above scheme, compared with the spiral shape formed by the plurality of straight line segments 400, the laser scanning track is set to be a curve, so that the energy accumulation of the laser at the corner position can be effectively reduced, a welding pool air hole is formed, the molten slurry overflows, the welding surplus is high, the appearance is abnormal, and the risk of low welding quality is caused, so that the welding quality can be effectively improved, and the reliability of a battery can be further improved.

In other embodiments, the laser scan trajectory may be constructed of multiple straight line segments 400. In other embodiments, the laser scanning track may also be formed by a plurality of straight line segments 400 and a plurality of curves, wherein two adjacent straight line segments 400 are connected by a curve.

As can be seen from fig. 6, the spiral track may be regarded as a line segment, which may be a curve, connecting one turn from inside to outside. The pitch of two adjacent line segments may be a spiral pitch.

In the scheme, the scanning track of the laser is set to be spiral with equal spiral spacing, so that a uniform molten pool can be formed on the structural member, the risk of energy accumulation is reduced, the surface appearance consistency of the structural member to be formed is good, the welding quality is high, and the reliability of the battery is high.

According to some embodiments of the present application, referring to fig. 6, the spiral pitch of the scanning track of the laser is L, and the diameter of the spot of the laser is D, so that 0.5 d+.l+.2d is satisfied.

The diameter of the spot of the laser light may be regarded as the area of the laser light acting on the structural member being a circular spot or, called spot, the joint area 40 may be constituted by a number of spots, the diameter of which may be D. Alternatively, the diameter D of the spot of the laser light may be regarded as the width of the solder mark formed by the laser light acting on the structural member.

In some embodiments, the spiral pitch L of the scan trajectory of the laser may be 0.5D, 0.6D, 0.7D, 0.8D … 1.5D, 1.6D, 1.7D, 1.8D, 1.9D, or 2D.

The screw pitch is too large, so that the virtual welding is caused, the welding quality is low, and the shearing force and the stripping force can not meet the capability requirement of dynamic and static loads. If the screw pitch is too small, energy accumulation exists, the risk of penetration exists, the welding quality is low, and the shearing force and the stripping force test can not meet the capability requirement of dynamic and static loads.

Therefore, in the above scheme, under the condition that the diameter D of the light spot of the laser is fixed, by limiting the relative relation between the spiral distance L and the diameter D of the light spot of the laser, the spiral distance L is not less than 0.5D and not more than 2D, so that the welding quality can be effectively improved, the requirements of dynamic and static load capacity of the shear force and stripping force test are met, and further, the battery has higher reliability.

According to some embodiments of the present application, step S2 of scanning by a laser to form n bonding regions 40 on a plurality of structural members to be welded, the n bonding regions 40 being disposed at intervals from each other includes:

the laser scans over a region to be welded to form a joint region 40, and the laser emitting device does not emit laser during switching from one joint region 40 to one region to be welded.

The "region to be welded" may refer to a region that has not yet been and is about to be laser-acted upon.

The laser emitting device may be a device capable of generating and emitting laser light, such as a laser head. The laser emitting device does not emit laser light, and may mean that the laser emitting device does not operate.

In the above scheme, in the process of switching from one joint area 40 to one to-be-welded area, the laser emitting device is controlled not to emit laser, so that energy accumulation caused by continuous welding due to the fact that the laser is not easy to control can be effectively reduced, a welding pool air hole is formed, and the risk of affecting welding quality is reduced, so that good welding quality is achieved between structural members, and further the battery has high reliability.

Referring to fig. 9, fig. 9 is a schematic block flow diagram of step S2 in some embodiments of the present application.

Step S2, forming n bonding areas 40 on the plurality of structural members to be welded by scanning the laser, where the n bonding areas 40 are spaced apart from each other, and includes:

in the step S2.1, n joint areas 40 are arranged in an annular array, n is greater than or equal to 2m, and m is an integer greater than or equal to 2.

Referring to fig. 10, fig. 10 is a schematic diagram illustrating an annular array of n bonding regions 40 according to some embodiments of the present application.

n is an integer greater than or equal to 2m, m is an integer greater than or equal to 2, i.e., n is an even number greater than or equal to 4. For example, n may be 4, 6, 8, 10, or the like.

The "n bonding regions 40 are arranged in a circular array" is understood to mean that the n bonding regions 40 are arranged at intervals in a surrounding manner with respect to a predetermined center as a reference point. Alternatively, it is understood that m pairs of engagement regions 40, each pair of engagement regions 40 being symmetrically distributed about the predetermined center.

In the above scheme, by arranging the plurality of joint areas 40 and arranging the plurality of joint areas 40 in a ring-shaped array, on one hand, the welding strength can be increased, and the static load capacity of the product can be improved; on the other hand, the risk that laser energy is concentrated in the centers of the plurality of joint regions 40 can be effectively reduced, and the risk that the welding quality is low due to the oxidation blackening of the molten paste protrusion caused by the energy concentration caused by welding can be reduced.

Referring to fig. 10 and 11, fig. 11 is a schematic block flow diagram of step S2 in some embodiments of the present application.

Scanning by laser to form n bonding regions 40 on a plurality of structural members to be welded, the n bonding regions 40 being disposed at intervals from each other, further comprising:

step S2.2, n bonding regions 40 comprising m bonding regions, the center line of two bonding regions 40 in each pair of bonding regions 40 passing through the center of the annular array; the 1 st to m-th bonding regions 40 to 40 are sequentially formed.

Referring to fig. 10, fig. 10 shows 3 pairs of bonding regions 40, i.e., 6 bonding regions 40, dividing the 6 bonding regions 40 into a first bonding region 41, a second bonding region 42, a third bonding region 43, a fourth bonding region 44, a fifth bonding region 45, and a sixth bonding region 46. The first bonding region 41 and the second bonding region 42 are the 1 st bonding region 40, and the central line of the first bonding region 41 and the second bonding region 42 passes through the center of the annular array, or the first bonding region 41 and the second bonding region 42 are diagonally arranged with respect to the center of the annular array.

The third joint region 43 and the fourth joint region 44 are the 2 nd joint region 40, and the central line of the third joint region 43 and the fourth joint region 44 passes through the center of the annular array, or the third joint region 43 and the fourth joint region 44 are diagonally arranged with respect to the center of the annular array. The fifth bonding region 45 and the sixth bonding region 46 are the 3 rd bonding region 40, and the centers of the fifth bonding region 45 and the sixth bonding region 46 are connected through the center of the annular array, or the fifth bonding region 45 and the sixth bonding region 46 are diagonally disposed with respect to the center of the annular array.

"n bonding regions 40 include m bonding regions, with the center line of two bonding regions 40 in each pair of bonding regions 40 passing through the center of the annular array. The 1 st to m-th bonding regions 40 are sequentially formed "it is understood that dividing n bonding regions 40 into m-bonding regions 40, two bonding regions 40 in each bonding region 40 being disposed diagonally with respect to the center of the annular array, and, at the time of welding, welding in order in units of" pairs ", such as welding one bonding region 40 in a certain bonding region 40 first and then welding the other bonding region 40 in the pair of bonding regions 40; when the welding of the pair of bonding regions 40 is completed, the other "pair" of bonding regions 40 are welded in the above-described order. For example, referring to fig. 10, the first joint region 41 and the second joint region 42 may be sequentially welded in sequence; and then welding the third joint region 43 and the fourth joint region 44 sequentially in this order; and then sequentially welding the fifth joint region 45 and the sixth joint region 46 in this order.

In the above-described aspect, among the plurality of joint regions 40 arranged in the annular array, there are a plurality of pairs of joint regions 40, the center connection of the two joint regions 40 of each pair is through the center of the annular array, and the distance value (minimum pitch) between the two joint regions 40 is the maximum value of the distance values of any two joint regions 40 among the plurality of joint regions 40 arranged in the annular array; this step provides a welding sequence of the bonding regions 40, which may be referred to as a diagonal welding sequence, i.e., the bonding regions 40 may be sequentially formed in a diagonal welding sequence with respect to the center of the annular array, and it may be understood that welding is smoothly performed in units of pairs, i.e., one of each pair of bonding regions 40 is welded first, and then the other bonding region 40 of each pair of bonding regions 40 is welded; and then the other pairs of joint regions 40 are welded. Because the distance value between the two joint areas 40 in each pair is the maximum value of the distance values of any two joint areas 40 in a plurality of joint areas 40 distributed in an annular array, the welding can be performed according to the diagonal welding sequence about the center of the annular array, on one hand, the energy accumulation can be effectively reduced, a welding pool air hole is formed, the molten paste overflows, the welding surplus is high, the appearance is abnormal, and the risk of low welding quality is caused, so that the welding quality between structural members is high, and the reliability of the battery is further improved; on the other hand, since the distance between the two bonding regions 40 in each pair is longer, the risk of welding between the two is lower, so that after welding one of the bonding regions 40 is completed, the laser emitting device can be quickly switched to the other region to be welded.

According to some embodiments of the present application, referring to FIG. 10, the minimum distance between two adjacent bonding regions 40 is P, the minimum distance from the innermost end of the bonding region 40 to the outermost end is R, and 2 R.ltoreq.P.ltoreq.4R is satisfied.

In some embodiments, the minimum distance from the innermost end to the outermost end of the engagement region 40 may be the radius R of the engagement region 40 in a spiral shape.

In some embodiments, the minimum distance P between two adjacent engagement regions 40 may be 2R, 2.5R, 3R, 3.5R, or 4R, or any of the two adjacent values.

In the above scheme, if the minimum distance between two adjacent joint areas 40 is too large, the interdependence effect of the two adjacent joint areas 40 will be too small, and the requirements of dynamic and static load capacity of the shear force and stripping force test cannot be met; the distance between two adjacent joint regions 40 is too small, so that risks of continuous welding and laser energy accumulation exist and the welding quality is affected, therefore, by limiting the relative relation between the minimum distance P between the two joint regions 40 and the minimum distance R from the innermost end to the outermost end of the joint regions, the minimum distance P between the two adjacent joint regions 40 is not less than 2R and not more than 4R, on one hand, the welding connection strength can be improved, the requirements of dynamic and static load capacity of a shearing force and stripping force test can be met, on the other hand, the risk that the welding quality is low due to continuous welding can be reduced, and therefore the welding quality between structural members is improved, and the battery has higher reliability.

According to some embodiments of the present application, a laser welding method 2000 is provided that may be used for laser welding of a harness isolation board of a battery, such as welding of a nickel plate to aluminum palladium on the harness isolation board. The nickel plate may be the second electrical connector 31 in the battery and the aluminum palladium may be the first electrical connector 32 in the battery. Before welding, the nickel sheet and the aluminum palladium are arranged in a laminated mode, and the copper nozzle of the laser injection device compresses the nickel sheet and the aluminum palladium under preset pressure. The laser welding method 2000 may be understood in conjunction with fig. 3-11. The laser welding method 2000 includes the steps of:

s1, carrying out laser scanning on a nickel sheet and aluminum palladium in a spiral track to form a joint region 40;

s2, forming n bonding areas 40 on the nickel sheet and the aluminum palladium by scanning of laser, wherein the n bonding areas 40 are arranged at intervals.

Wherein, step S2 further comprises:

s2.1, n joint areas 40 are arranged in an annular array, n is greater than or equal to 2m, and m is an integer greater than or equal to 2;

In step S1, referring to fig. 6, the laser beam is welded according to a predetermined spiral track, so that the innermost end of the final spiral bonding area 40 (i.e. the weld mark) is the start of the laser beam scanning, and the portion denoted by the reference symbol "a" in fig. 6 is the end of the laser beam scanning, and the portion denoted by the reference symbol "B" in fig. 6 is the end of the laser beam scanning. In the process, the laser is always started to always irradiate the nickel sheet and the aluminum palladium.

In step S2, referring to fig. 10, six bonding areas 40 are formed by six times of welding on the nickel sheet and the aluminum palladium, and the six bonding areas 40 are arranged in a ring-shaped array, and each bonding area 40 is welded independently.

The six bonding regions 40 may be sequentially formed in a diagonal welding order with respect to the center of the annular array, for example, referring to fig. 10, a first bonding region 41 and a second bonding region 42 may be sequentially welded first; and then welding the third joint region 43 and the fourth joint region 44 sequentially in this order; and then sequentially welding the fifth joint region 45 and the sixth joint region 46 in this order.

In some embodiments, in step S2, the welding power provided by the laser emitting device corresponding to each of the bonding regions 40 may be the same or different, for example, the welding powers corresponding to the first bonding region 41 to the sixth bonding region 46 may be 800w; or, for example, the welding powers corresponding to the first joining region 41 and the second joining region 42 may be 800w, respectively; the welding powers corresponding to the third to sixth bonding regions 43 to 46 may be 700w, respectively. In other embodiments, the welding power corresponding to the joint region 40 may be other values, such as 600w.

In some embodiments, in step S2, the welding speed provided by the laser emitting device corresponding to each of the bonding regions 40 may be the same or different, for example, the welding speeds corresponding to the first bonding region 41 to the sixth bonding region 46 may be 510mm/S; or, for example, the welding speeds corresponding to the first joining region 41 and the second joining region 42 may be 510mm/s, respectively; the welding speeds corresponding to the third to sixth bonding areas 43 to 46 may be 400mm/s, respectively. In other embodiments, the welding speed corresponding to the joint region 40 may be other values, such as 300mm/s, 470mm/s, 480mm/s, or the like.

In some embodiments, in step S2, the spiral pitch of the spiral welding track corresponding to each joint region 40 may be the same, for example, each 0.1mm. In other embodiments, the pitch of the spiral weld track corresponding to the engagement region 40 may be other values, such as 0.2mm.

The radius of the corresponding spiral weld track (the minimum distance from the innermost end to the outermost end of the joint region 40) for each joint region 40 may be the same, e.g., 0.55mm. In other embodiments, the radius of the corresponding spiral weld path of the joining region 40 may be other values.

The foregoing description is only of the preferred embodiments of the present application and is not intended to limit the same, but rather, various modifications and variations may be made by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A battery, comprising:

a plurality of structural members joined to each other by laser welding and forming a joined region, the joined region being in the shape of a spiral, the number of the joined regions being a plurality.

2. The battery of claim 1, wherein the battery is configured to provide the battery with a plurality of cells,

the battery comprises a plurality of battery cells;

the plurality of structural members includes a sampling member, a first electrical connector, and a second electrical connector; the battery cells are electrically connected through the first electric connectors, and each first electric connector is electrically connected with the sampling piece through one second electric connector;

wherein the sampling member and the second electrical connection member are bonded to each other by laser welding and the bonding region is formed; and/or the first electric connector and the second electric connector are jointed with each other through laser welding, and the joint area is formed.

3. The battery of claim 1, wherein the battery is configured to provide the battery with a plurality of cells,

the battery comprises a battery cell; the battery cell includes a case and an electrode assembly disposed in the case; an electrode terminal is arranged on the shell;

the plurality of structural members include tabs of the electrode assembly and the electrode terminals, the tabs of the electrode assembly are directly welded with the electrode terminals, and the tabs and the electrode terminals are joined to each other by laser welding and form the joint region therebetween.

4. The battery of claim 1, wherein the battery is configured to provide the battery with a plurality of cells,

the battery comprises a battery cell; the battery cell includes a case and an electrode assembly disposed in the case; an electrode terminal is arranged on the shell, and a tab of the electrode assembly is electrically connected with the electrode terminal through an adapter;

the plurality of structural members include tabs of the electrode assembly, the adapter and the electrode terminals, the tabs and the adapter are joined to each other by laser welding and the joint region is formed; and/or the adapter and the electrode terminal are joined to each other by laser welding and the joint region is formed.

5. The battery of claim 1, wherein the battery is configured to provide the battery with a plurality of cells,

the structural member is sheet-shaped.

6. The battery of claim 1, wherein the battery is configured to provide the battery with a plurality of cells,

the number of the joint areas is n, n is more than 2m, m is an integer greater than or equal to 2, and n joint areas are arranged in an annular array.

7. The battery of claim 6, wherein the battery is configured to provide the battery with a battery cell,

the minimum distance between two adjacent joint areas is P, and the minimum distance from the innermost end of the joint area to the outermost end of the joint area is R, so that the minimum distance is 2R < P < 4R.

8. A powered device comprising a battery as claimed in any one of claims 1-7 for providing electrical energy.

9. A laser welding method characterized by irradiating laser light toward a plurality of structural members to be welded which are stacked, forming a joining region on the plurality of structural members to be welded by scanning of the laser light so that the plurality of structural members are joined to each other;

the laser welding method comprises the following steps:

laser scanning the plurality of structural members to be welded in a spiral track to form the joint region;

And n joint areas are formed on the structural members to be welded through scanning of the laser, and are mutually arranged at intervals, wherein n is more than or equal to 2.

10. The laser welding method according to claim 9, wherein,

the laser scanning the plurality of the structural members to be welded in a spiral trajectory to form the joint region includes:

laser scanning the plurality of structural members to be welded in a spiral track from inside to outside to form the joint region; or alternatively, the first and second heat exchangers may be,

the plurality of the structural members to be welded are laser scanned in an outside-in helical trajectory to form the joining region.

11. The laser welding method according to claim 9, wherein,

the scanning track of the laser is a curve.

12. The laser welding method according to claim 9, wherein,

the scanning track of the laser is spiral with equal spiral space.

13. The laser welding method according to claim 12, wherein,

the spiral distance of the scanning track of the laser is L, the diameter of the light spot of the laser is D, and L is more than or equal to 0.5D and less than or equal to 2D.

14. The laser welding method according to claim 9, wherein,

the scanning by the laser to form n bonding areas on the structural members to be welded, wherein the n bonding areas are mutually spaced, and the method comprises the following steps:

the laser scans in a region to be welded to form the joint region, and the laser emitting device does not emit the laser in the process of switching from one joint region to one region to be welded.

15. The laser welding method according to claim 9, wherein,

n bonding areas are arranged in a ring-shaped array, n is more than or equal to 2m, and m is an integer more than or equal to 2.

16. The laser welding method according to claim 15, wherein,

the scanning of the laser is used for forming n joint areas on the structural members to be welded, the n joint areas are mutually spaced, and the method further comprises the following steps:

the n bonding regions comprise m bonding regions, and the central connecting line of two bonding regions in each pair of bonding regions passes through the center of the annular array; the 1 st pair of the bonding regions to the m-th pair of the bonding regions are sequentially formed.

17. The laser welding method according to claim 9, wherein,