Battery core welding method and equipment

Abstract

The present application discloses a cell welding method and equipment, which relates to the technical field of battery production and manufacturing. The cell welding method includes the following steps: driving the cell to rise and move to a pre-welding position, driving the clamping piece to move to abut against the outer side of the shell; wherein the top surface of the clamping piece is flush with the top surface of the shell, and a clearance gap is provided on the side of the clamping piece close to the shell; pre-welding the top cover and the shell at the position of the clearance gap; driving the clamping piece to move to a first position in a direction away from the shell, driving the cell to move to a full welding position, driving the clamping piece to move from the first position toward the shell to abut against the outer side of the shell; wherein the top surface of the clamping piece is lower than the top surface of the shell; and fully welding the top cover and the shell. The cell welding method can reduce the risk of laser burning the clamping piece, and can also reduce the risk of laser burning the diaphragm and causing the cell to short-circuit.

Description

Technical Field

[0001] The present application relates to the technical field of battery production and manufacturing, and in particular to a battery core welding method and equipment. Background Art

[0002] During the welding process of the battery cell's outer shell and top cover, there is a laser leakage phenomenon in the welding process. The laser leakage causes the battery cell diaphragm to be ablated by the laser and then punctured, causing a short circuit inside the battery cell, posing a fire risk. Summary of the invention

[0003] The main purpose of the present application is to propose a battery cell welding method and equipment, aiming to at least improve the technical problem of laser leakage in the welding process of the battery cell shell and top cover in the related art.

[0004] To achieve the above-mentioned purpose, according to some embodiments of the present application, the present application provides a battery core welding method, which is applied to a battery core welding device, the battery core welding device comprising a first driving member, a second driving member, a pressing member and a laser output head, and is used to weld a top cover and a shell of a battery core, and comprises the following steps:

[0005] The battery cell is driven to rise and move to the pre-welding position, and the pressing piece is driven to move to abut against the outer side surface of the shell; wherein the top surface of the pressing piece is arranged flush with the top surface of the shell, and a side of the pressing piece close to the shell is provided with an avoidance notch;

[0006] Pre-welding the top cover and the outer shell at the avoidance notch position;

[0007] The pressing member is driven to move to a first position in a direction away from the housing, the battery cell is driven to move to a full welding position, and the pressing member is driven to move from the first position toward the housing to abut against an outer side surface of the housing; wherein the top surface of the pressing member is lower than the top surface of the housing;

[0008] The top cover and the outer shell are fully welded.

[0009] In the above-mentioned embodiment of the present application, an avoidance notch is provided on the side of the clamping piece close to the outer shell, the clamping piece is set to be flush with the top surface of the outer shell during the pre-welding process, and the top cover and the outer shell are welded at the position of the outer shell corresponding to the avoidance notch. This can not only reduce the risk of laser burning the clamping piece, but also can clamp the outer shell from the top of the outer shell, that is, the welding position, reducing the risk of outward expansion of the outer shell, resulting in excessive gap between the outer shell and the top cover, thereby reducing the possibility of light leakage, and further reducing the risk of laser burning the diaphragm and causing a short circuit in the battery cell.

[0010] In some embodiments, the pressing member is a pressure strip, and the step of driving the pressing member to move to abut against the outer side surface of the housing comprises:

[0011] The side of the pressure strip provided with the avoidance notch is arranged toward the shell, and the pressure strip is driven to move until it is completely in contact with the outer side surface of the shell, and the length of the pressure strip is greater than the length of the top edge of the outer side surface in contact with the pressure strip.

[0012] In the above-mentioned embodiments of the present application, the pressing piece is set as a pressure strip, and the pressure strip is arranged to fit the outer side surface of the shell to press the shell. At the same time, the length of the pressure strip is designed to be greater than the length of the top edge of the outer side surface that fits the pressure strip, thereby avoiding the phenomenon that the outer side surface fails to abut in place due to the size of the pressure strip, thereby reducing the risk of local expansion of the shell.

[0013] In some embodiments, the battery cell is a square battery cell, the number of the pressing members is two, and the two pressing members are respectively arranged on two opposite sides of the square battery cell, and the step of driving the pressing member to move to abut against the outer side surface of the housing includes:

[0014] The two pressing members are driven to move toward two opposite outer side surfaces of the shell, so that the two pressing members are respectively in contact with two opposite outer side surfaces of the shell.

[0015] In the above embodiment of the present application, by setting the number of clamping members to two, the two clamping members respectively clamp the shell from the two outer sides of the square battery cell shell, so that the shell is evenly stressed and the clamping is more stable.

[0016] In some embodiments, the step of driving the battery cell to move to a full welding position includes:

[0017] Driving the battery cell to descend to an initial position;

[0018] The battery cell is driven to rise to a full welding position, and the top cover and the outer shell are fully welded.

[0019] In the above-mentioned embodiment of the present application, the first driving member first lowers the battery cell to the initial position, and then drives the battery cell to rise to the full welding position according to a preset stroke, which can reduce the risk of position deviation and improve the accuracy of the position after movement.

[0020] In some embodiments, the step of arranging the top surface of the pressing member lower than the top surface of the housing comprises:

[0021] The top surface of the pressing member is controlled to be 1.5 mm to 2 mm lower than the top surface of the shell.

[0022] In the above-mentioned embodiment of the present application, by setting the top surface of the clamping member lower than the top surface of the shell, and the difference range is 1.5mm-2mm, the risk of laser ablation of the clamping member and the risk of light leakage caused by the expansion of the shell can be reduced.

[0023] In some embodiments, before the step of driving the pressing member to move to abut against the outer side surface of the housing, the method further comprises the steps of:

[0024] The battery core is driven to rotate, thereby adjusting the welding angle of the battery core.

[0025] By arranging the battery cell to be rotatable, specifically by driving the welding platform on which the battery cell is mounted to rotate through a rotating member, the welding angle between the battery cell and the laser output head can be adjusted, and functions such as side welding can also be achieved.

[0026] According to some embodiments of the present application, the present application provides a battery cell welding device for welding the top cover and the outer shell of the battery cell, the battery cell welding device comprising a first driving member, a second driving member, a clamping member and a laser output head; the output shaft of the second driving member is connected to the clamping member, and the side of the clamping member facing away from the output shaft is provided with an avoidance notch; the first driving member is used to drive the battery cell to move to a pre-welding position, and the second driving member is used to drive the clamping member to abut against the outer shell when the battery cell moves to the pre-welding position, and make the clamping member The top surface is arranged flush with the top surface of the outer shell, and the laser output head is used to pre-weld the top cover and the outer shell at the pre-welding position and corresponding to the avoidance gap; the first driving member is also used to drive the battery cell to move to the full welding position, and the second driving member is also used to drive the clamping member to move toward the outer shell until it abuts against the outer side surface of the outer shell when the battery cell moves to the full welding position, and the top surface of the clamping member is arranged lower than the top surface of the outer shell; the laser output head is used to fully weld the top cover and the outer shell at the full welding position.

[0027] By setting an avoidance notch on the side of the clamping piece close to the outer shell, setting the clamping piece flush with the top surface of the outer shell during the pre-welding process, and welding the top cover and the outer shell at the position of the outer shell corresponding to the avoidance notch, the risk of laser burning the clamping piece can be reduced, and the outer shell can be clamped from the top of the outer shell, that is, the welding position, reducing the risk of outward expansion of the outer shell, resulting in excessive gap between the outer shell and the top cover, and thus reducing the possibility of light leakage, thereby reducing the risk of laser burning the diaphragm and causing a short circuit in the battery cell.

[0028] In some embodiments, the battery cell is a square battery cell, the pressing member includes a pressure strip, the number of the second driving member and the pressing member are two and they are arranged in one-to-one correspondence, the two pressing members are respectively arranged on two opposite sides of the square battery cell, and the length of the pressure strip is greater than the length of the top edge of the outer side surface that is in contact with the pressure strip.

[0029] By setting the number of the pressing pieces to two, the two pressing pieces press the outer shell from two outer sides of the square battery cell outer shell respectively, so that the outer shell is subjected to uniform force and the clamping is more stable.

[0030] In some embodiments, there are multiple avoidance gaps, each of which extends to the edge of the pressure strip, and the multiple avoidance gaps are arranged at intervals along the length direction of the pressure strip.

[0031] By setting a plurality of avoidance gaps at intervals corresponding to the pre-welding position settings of the outer shell and the top cover, it is possible to avoid burning the pressure strip during the pre-welding process. It can also have the effect of pressing the outer shell from the top of the outer shell, reducing the risk of outward expansion and deformation of the outer shell, thereby reducing the risk of laser entering the battery cell and causing a short circuit in the battery cell.

[0032] In some embodiments, the laser output head is a swing output head.

[0033] By adopting a swinging output head, welding swing can be achieved, the welding width can be increased, and a larger welding molten pool can be formed, thereby reducing the risk of laser passing through the gap between the top cover and the outer shell, and reducing the risk of short circuit of the battery cell.

[0034] In some embodiments, the battery core welding equipment further includes a rotating member and a welding platform, the battery core is mounted on the welding platform, and the rotating member is connected to the welding platform.

[0035] By arranging the battery cell to be rotatable, specifically by driving the welding platform on which the battery cell is mounted to rotate through a rotating member, the welding angle between the battery cell and the laser output head can be adjusted, and functions such as side welding can also be achieved.

[0036] In some embodiments, the first driving member includes a servo motor, and the servo motor is used to drive the battery cell to move.

[0037] By adopting a servo motor, the position of the battery cell can be accurately controlled, thereby improving the reliability of welding.

[0038] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0040] Figure 1 A schematic diagram of the structure of a vehicle according to some embodiments of the present application;

[0041] Figure 2 A schematic diagram of the exploded structure of a battery according to some embodiments of the present application;

[0042] Figure 3 A schematic diagram of a process flow of a battery core welding method according to some embodiments of the present application;

[0043] Figure 4 This is a schematic diagram of the main structure of a battery cell in an initial position of a battery cell welding method according to some embodiments of the present application;

[0044] Figure 5 This is a schematic diagram of the main structure of a battery cell welding method in some embodiments of the present application, in which a battery cell is raised to a pre-welding position;

[0045] Figure 6 A schematic diagram of a top view of a battery cell rising to a pre-welding position in a battery cell welding method according to some embodiments of the present application;

[0046] Figure 7 This is a schematic diagram of the main structure of a battery cell welding method in some embodiments of the present application, in which a clamping member clamps a battery cell for pre-welding;

[0047] Figure 8 A schematic diagram of a top view of a battery cell welding method in some embodiments of the present application in which a clamping member clamps a battery cell for pre-welding;

[0048] Fig. 9 This is a schematic diagram of the main structure of the clamping member away from the housing after pre-welding of the battery cell welding method in some embodiments of the present application is completed;

[0049] Fig.10 This is a schematic diagram of a top view of the structure in which the pressing member is away from the housing after pre-welding of the battery core welding method in some embodiments of the present application is completed;

[0050] Fig.11 This is a schematic diagram of the main structure of a battery cell welding method in some embodiments of the present application, in which a battery cell is moved to a full welding position;

[0051] Fig.12 A schematic diagram of a top view of a battery cell moving to a full welding position in a battery cell welding method according to some embodiments of the present application;

[0052] Fig.13 A schematic diagram of a process flow of a battery core welding method according to some embodiments of the present application;

[0053] Fig.14 A schematic diagram of a process flow of a battery core welding method according to some embodiments of the present application;

[0054] Fig.15 A schematic diagram of a process flow of a battery core welding method according to some embodiments of the present application;

[0055] Fig.16A schematic diagram of a process flow of a battery core welding method according to some embodiments of the present application;

[0056] Fig.17 This is a partial structural schematic diagram of a battery core welding device according to some embodiments of the present application;

[0057] Fig.18 This is a schematic structural diagram of a clamping member of a battery core welding device according to some embodiments of the present application;

[0058] Fig.19 A partial structural schematic diagram of a battery core welding device from one perspective in some embodiments of the present application;

[0059] Fig. 20 A schematic diagram of the weld structure of a battery core welding device with a swinging ejection head in some embodiments of the present application.

[0060] Description of Figure Numbers:

[0061] 1000. Vehicles;

[0062] 100, battery; 200, controller; 300, motor;

[0063] 10. Box body; 11. First part; 12. Second part;

[0064] 20. battery cell; 21. top cover; 22. outer shell;

[0065] 1. Pressing member; 101. Top surface of pressing member; 2. Avoidance gap; 3. First driving member; 4. Second driving member; 5. Laser output head; 6. Rotating member; 7. Welding platform; 8. Cushion block;

[0066] A. Pre-welding position; B. Full welding position; C. First position.

[0067] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0068] The following will be combined with the drawings in this embodiment to clearly and completely describe the technical solution in this embodiment. Obviously, the described embodiment is only a part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0069] It should be noted that all directional indications in this embodiment (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0070] In addition, the descriptions of "first", "second", etc. in this application are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0071] In this application, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0072] In addition, the technical solutions between the various embodiments of the present application can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by this application. It should be understood that the specific embodiments described here are only used to explain this application and are not used to limit this application.

[0073] The descriptions of directions such as "up", "down", "front", "back", "left" and "right" in this application are based on the directions shown in the drawings and are only used to explain the relative positional relationship between the components in the postures shown in the drawings. If the specific posture changes, the directional indication will also change accordingly.

[0074] At present, from the perspective of market development, the application of power batteries is becoming more and more extensive. Power batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, electric cars, as well as military equipment and aerospace and other fields. With the continuous expansion of the application field of power batteries, the market demand is also constantly expanding.

[0075] The production process of square shell batteries and cylindrical cells includes the welding process of the outer shell and the top cover. The outer shell is the shell outside the cell, which has a cavity inside. The bare cell is placed in the cavity. The top cover is used to weld to the opening of the cavity, that is, welded to the opening of the outer shell. The welding method is laser welding. However, in actual production, short circuits often occur inside the cell after welding, and in severe cases, fire and smoke will occur.

[0076] Such problems have always affected the qualified rate of battery production and are also a major problem that plagues the industry. After careful research, the applicant found that most of the cells with internal short circuits have the diaphragm inside the cell burned.

[0077] After careful observation and repeated verification of the laser welding process of the top cover and the shell, the applicant found that there was a phenomenon of laser leakage during the welding process of the top cover and the shell. That is, part of the laser penetrated into the battery cell through the gap between the shell and the top cover, or after entering the gap between the shell and the top cover, it was reflected by the end surface between the shell and the top cover and entered the battery cell, causing the diaphragm inside the battery cell to burn and cause the battery cell to short-circuit. The fundamental reason for this phenomenon is that the gap between the shell and the top cover is too large, and the welding molten pool cannot completely fill the gap, so the phenomenon of laser leakage occurs, which eventually causes the battery cell diaphragm to be burned and cause a short-circuit failure.

[0078] Please refer to Figure 1 , Figure 1 A schematic diagram of the structure of a vehicle 1000 provided for some embodiments of the present application. The electrical device may be a vehicle 1000, and the vehicle 1000 may be a fuel vehicle, a gas vehicle, or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle, or an extended-range vehicle, etc. A battery 100 is provided inside the vehicle 1000, and the battery 100 may be provided at the bottom, head, or tail of the vehicle 1000. The battery 100 may be used to power the vehicle 1000, for example, the battery 100 may be used as an operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300, and the controller 200 is used to control the battery 100 to power the motor 300, for example, for starting, navigating, and operating power requirements of the vehicle 1000 during driving.

[0079] In some embodiments of the present application, the battery 100 can not only serve as an operating power source for the vehicle 1000, but also serve as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0080] Please refer to Figure 2 , Figure 2Schematic diagram of the exploded structure of a battery 100 provided in some embodiments of the present application. The battery 100 includes a box 10 and a battery cell 20, and the battery cell 20 is accommodated in the box 10. Among them, the box 10 is used to provide a storage space for the battery cell 20, and the box 10 can adopt a variety of structures. In some embodiments, the box 10 may include a first part 11 and a second part 12, the first part 11 and the second part 12 cover each other, and the first part 11 and the second part 12 jointly define a storage space for accommodating the battery cell 20. The second part 12 may be a hollow structure with one end open, the first part 11 may be a plate-like structure, and the first part 11 covers the open side of the second part 12, so that the first part 11 and the second part 12 jointly define a storage space; the first part 11 and the second part 12 may also be hollow structures with one side open, and the open side of the first part 11 covers the open side of the second part 12. Of course, the box 10 formed by the first part 11 and the second part 12 may be in a variety of shapes, such as a cylinder, a cuboid, etc.

[0081] In the battery 100, there may be multiple cells 20, and the multiple cells 20 may be connected in series, in parallel, or in a mixed connection. A mixed connection means that the multiple cells 20 are both connected in series and in parallel. The multiple cells 20 may be directly connected in series, in parallel, or in a mixed connection, and then the whole formed by the multiple cells 20 may be accommodated in the box 10; of course, the battery 100 may also be a battery module formed by connecting multiple cells 20 in series, in parallel, or in a mixed connection, and then the multiple battery modules may be connected in series, in parallel, or in a mixed connection to form a whole, and then accommodated in the box 10. The battery 100 may also include other structures, for example, the battery 100 may also include a busbar component for realizing electrical connection between the multiple cells 20.

[0082] Each battery cell 20 may be a secondary battery or a primary battery, or a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto. The battery cell 20 may be cylindrical, flat, rectangular, or in other shapes.

[0083] The present application provides a battery cell welding method and equipment, which are used to weld the top cover and aluminum shell of the battery cell during the battery manufacturing process.

[0084] Please refer to Figure 3 According to some embodiments of the present application, the present application provides a battery core welding method, which is applied to a battery core welding device, the battery core welding device includes a first driving member 3, a second driving member 4, a pressing member 1 and a laser output head 5, and is used to weld a top cover 21 and a shell 22 of a battery core 20, including the following steps:

[0085] S100, driving the battery cell 20 to move upward to the pre-welding position A, driving the pressing member 1 to move to abut against the outer side surface of the housing 22; wherein the top surface 101 of the pressing member is flush with the top surface of the housing 22, and a side of the pressing member 1 close to the housing 22 is provided with an avoidance notch 2;

[0086] Pre-welding position A Figure 7 As shown in Figure 4-Figure 8 The battery cell 20 includes a top cover 21 and an outer shell 22. The laser output head 5 is used to emit a laser to weld the top cover 21 and the outer shell 22. The first driving member 3 is used to drive the battery cell 20 to move toward the direction of the laser output head 5 so that the battery cell 20 is close to the laser output head 5, which is convenient for the subsequent welding by the laser output head 5. The pre-welding position A here refers to the position at which the laser output head 5 pre-welds the top cover 21 and the outer shell 22. The pre-welding position A can be the set coordinate position of the battery cell 20 rising. The battery cell 20 can be located at the initial position at the beginning. When the first driving member 3 drives the battery cell 20 to rise to the preset position, the first driving member 3 temporarily stops working. When the battery cell 20 rises to the pre-welding position A, the second driving member 4 connected to the clamping member 1 drives the clamping member 1 to move toward the outer shell 22 of the battery cell 20 and abuts against it, and the outer shell 22 is clamped by the clamping member 1. It is worth noting that there is an essential difference from the related art, such as Figure 7 As shown, the top surface 101 of the clamping member of the present application is flush with the top surface of the shell 22, that is, in the vertical direction or the height direction, the top surface 101 of the clamping member and the top surface of the shell 22 are at the same height. This design is to clamp the top of the shell 22 to prevent the shell 22 from expanding and deforming outward during welding, so that a gap is generated between the shell 22 and the top cover 21 or the gap between the shell 22 and the top cover 21 is increased, and then the laser leaks at the gap. However, setting the clamping member 1 to be flush with the top surface of the shell 22 will result in a more serious problem, that is, during welding, there is a risk of laser ablation of the clamping member 1, and because it is set flush, this risk is very large, thus reducing the qualified rate of the product.

[0087] Based on this, after careful research, the applicant sets an avoidance notch 2 on the clamping member 1, and the avoidance notch 2 is set on the side of the clamping member 1 facing the shell 22, so that the shell 22 and the top cover 21 can be pre-welded at the location of the avoidance notch 2, so as not to burn the clamping member 1. It should be noted that the pre-welding here is the preliminary welding of the shell 22 and the top cover 21, and only some point welding is required for some positions of the shell 22 and the top cover 21. In the subsequent full welding, the entire weld is welded at the connection position between the top cover 21 and the shell 22. Therefore, some avoidance notches 2 can be set on the side of the clamping member 1 facing the shell 22. The number of avoidance notches 2 can be multiple, and multiple avoidance notches 2 are set at intervals on the clamping member 1. The avoidance notches 2 are used for pre-welding the laser output head 5 at the corresponding position of the shell 22, and the part of the side where the clamping member 1 abuts against the shell 22 without the avoidance notches 2 is used to abut against the shell 22, reducing the risk of the shell 22 expanding and deforming outward, so as to reduce the risk of a large gap between the shell 22 and the top cover 21. In this way, the shell 22 is compressed, and an avoidance space is set at the position where the shell 22 and the top cover 21 are welded, so as to prevent the clamping member 1 from being ablated by the laser during the welding process.

[0088] S200, pre-welding the top cover 21 and the outer shell 22 at the position of the avoidance gap 2;

[0089] Combined with reference Figure 7 and Figure 8 It should be noted that pre-welding is preliminary welding at several points between the top cover 21 and the outer shell 22. Avoidance notches 2 can be set at the positions of the clamping member 1 corresponding to the several points that need to be pre-welded. The avoidance notch 2 is a notch set on the clamping member 1. Pre-welding of the top cover 21 and the outer shell 22 at the position of the outer shell 22 corresponding to the avoidance notch 2 can avoid burning the clamping member 1 during the welding process. At the same time, the pre-welding points are arranged at intervals, so the avoidance notches 2 can also be arranged at intervals on the clamping member 1. The positions on the clamping member 1 where the avoidance notches 2 are not arranged abut against the outer side surface of the outer shell 22 to reduce the risk of outward expansion of the outer shell 22 during welding.

[0090] S300, driving the pressing member 1 to move to the first position C in a direction away from the housing 22. The first position C is as follows: Fig. 9 As shown, the driving cell 20 moves to the full welding position B. The full welding position B is as shown in FIG. Fig.11 As shown in , the pressing member 1 is driven to move from the first position C toward the housing 22 to abut against the outer side surface of the housing 22; wherein the top surface 101 of the pressing member is lower than the top surface of the housing 22;

[0091] Combined with reference Figure 9-12After the pre-welding is completed, it is necessary to drive the first driving member 3 to drive the battery cell 20 to move to the full welding position B, where the laser output head 5 fully welds the outer shell 22 and the top cover 21. At this time, it is necessary to first drive the clamping member 1 through the second driving member 4 to loosen the battery cell 20, that is, drive the clamping member 1 to move in a direction away from the outer shell 22. After the battery cell 20 is loosened, it is convenient to drive the battery cell 20 to move to the full welding position B through the first driving member 3, and then drive the clamping member 1 through the second driving member 4 to move toward the outer shell 22 and abut against the outer side of the outer shell 22 to compress the outer shell 22, which also reduces the risk of deformation of the outer shell 22. However, it is worth noting that full welding refers to welding along the entire joint of the top cover 21 and the outer shell 22. At this time, the top surface 101 of the clamping member is lower than the top surface of the outer shell 22. Because if the top surface 101 of the clamping member is flush with the top surface of the outer shell 22 or even higher than the top surface of the outer shell 22, there is a risk of burning the clamping member 1 during the full welding process. However, since there is preliminary fixation by pre-welding and the pressing member 1 is still pressed from the outer side of the shell 22, the risk of the shell 22 expanding outward can be reduced.

[0092] S400, fully welding the top cover 21 and the outer shell 22.

[0093] Combined with reference Fig.11 Full welding refers to welding along the joint of the shell 22 and the top cover 21 to form a complete weld. At this time, since the top surface 101 of the clamping member is lower than the top surface of the shell 22 and there is a certain distance from the welding position, the laser emitted by the laser output head 5 is difficult to burn the clamping member 1 during the full welding process.

[0094] In the above embodiment of the present application, by setting an avoidance notch 2 on the side of the clamping member 1 close to the shell 22, the clamping member 1 is set to be flush with the top surface of the shell 22 during the pre-welding process, and the top cover 21 and the shell 22 are welded at the position of the shell 22 corresponding to the avoidance notch 2, the risk of laser burning the clamping member 1 can be reduced, and the shell 22 can be pressed from the top of the shell 22, that is, the welding position, reducing the risk of the shell 22 expanding outward, resulting in an excessive gap between the shell 22 and the top cover 21, and thus reducing the possibility of light leakage, thereby reducing the risk of laser burning the diaphragm and causing a short circuit in the battery cell 20. At the same time, setting the top surface 101 of the clamping member lower than the top surface of the shell 22 during full welding can also reduce the risk of burning the clamping member 1.

[0095] Reference Fig.13 In some embodiments, the pressing member 1 is a pressure strip, and the step S100 includes:

[0096] S101, the side of the pressure strip provided with the avoidance notch 2 is arranged toward the shell 22, and the pressure strip is driven to move until it is completely in contact with the outer side surface of the shell 22, and the length of the pressure strip is greater than the length of the top edge of the outer side surface in contact with the pressure strip.

[0097] Combined with reference Fig.12 , the pressure strip faces one side of the outer shell 22, that is, the side of the pressure strip away from the second driving member 4, and the avoidance notch 2 is specifically set at the edge of the pressure strip and passes through the edge of the pressure strip. The contour shape of the pressure strip facing the outer shell 22 is adapted to the contour shape of the outer side surface of the outer shell 22, so that the outer shell 22 can be clamped better, so that the pressure strip and the outer side surface of the outer shell 22 are completely in contact, which is conducive to pressing the outer shell 22. Specifically, the pressure strip can be an elastic member made of a material with a certain elasticity, such as silicone or foam. In the actual production process, in order to avoid bending or warping of the edge of the pressure strip, the length of the pressure strip will be set to be greater than the length of the top edge of the outer side surface, and the part that is greater than the length, such as Fig.12 As shown in K in the figure, it is helpful to tighten the outer side of the shell 22, and it can also be applied to battery cells 20 of other heights.

[0098] In the above-mentioned embodiment of the present application, the pressing piece 1 is set as a pressure strip, and the pressure strip is arranged to fit the outer side surface of the shell 22 to press the shell 22. At the same time, the length of the pressure strip is designed to be greater than the length of the top edge of the outer side surface that fits the pressure strip, so as to avoid the phenomenon that the outer side surface cannot be properly abutted due to the size of the pressure strip, thereby reducing the risk of local expansion of the shell 22.

[0099] Reference Fig.14 In some embodiments, the battery cell 20 is a square battery cell, the number of the pressing members 1 is two, and the two pressing members 1 are respectively arranged on two opposite sides of the square battery cell, and the step S100 includes:

[0100] S102 , driving the two pressing members 1 to move toward the two opposite outer side surfaces of the housing 22 , so that the two pressing members 1 abut against the two opposite outer side surfaces of the housing 22 , respectively.

[0101] Combined with reference Fig.11 and Fig.12 , the battery cell 20 is a square battery cell, and the corresponding shell 22 is a square shell. At this time, the number of the clamping members 1 can be two, and the two clamping members 1 respectively clamp the shell 22 of the square battery cell from the outer sides where the two long sides of the square shell are located. At this time, the number of the second driving members 4 can be one or two. When the number of the second driving members 4 is one, the two clamping members 1 can be connected by a second driving member 4 through a transition structure, so that the two clamping members 1 can move closer to each other or away from each other, clamp the shell 22 when approaching each other, and release the shell 22 when moving away from each other. By setting the two clamping members 1 to abut against the two opposite outer sides of the shell 22, the shell 22 can be subjected to uniform force. When the number of the second driving member 4 is one, a second driving member 4 can be set to be connected to the first clamping member 1 accordingly.

[0102] In the above-mentioned embodiment of the present application, by setting the number of clamping members 1 to two, the two clamping members 1 respectively press the shell 22 and the top cover 21 from the two outer sides of the square battery cell shell 22, so that the shell 22 is evenly stressed, reducing the possibility of the shell 22 expanding outward during the welding process, and the clamping is also more stable.

[0103] Reference Fig.15 In some embodiments, the step of S400 includes:

[0104] S401, driving the battery cell 20 to descend to an initial position;

[0105] S402 , driving the battery cell 20 to rise to the full welding position B, and fully welding the top cover 21 and the outer shell 22 .

[0106] The initial position refers to the position where the battery cell 20 is raised before step S100, and can also be considered as the position when the battery cell 20 is installed on the first driving member 3. After the battery cell 20 is pre-welded, the battery cell 20 can be driven down to the initial position by the first driving member 3. The full welding position B refers to the position where the outer shell 22 and the top cover 21 are fully welded. This position, like the initial position and the pre-welding position A, can be pre-set by the program. After the first driving member 3 drives the battery cell 20 to descend to the initial position, the first driving member 3 drives the battery cell 20 to rise to the full welding position B according to the preset program. In this way, by first transporting the battery cell 20 to the initial position and then driving the battery cell 20 from the initial position to the full welding position B, returning to the initial position can correct the driving stroke of the first driving member 3, and the position after the move is more accurate. That is to say, if the pre-welding position A is inaccurate or the position of the battery cell 20 changes slightly during the pre-welding process, it will not affect the subsequent determination of the full welding position B, because the full welding position B is determined according to the relative position to the initial position, rather than the relative position to the pre-welding position A.

[0107] In the above-mentioned embodiment of the present application, the battery cell 20 is first lowered to the initial position by the first driving member 3, and then the battery cell 20 is driven to rise to the full welding position B according to a preset stroke by the first driving member 3, which can reduce the risk of position deviation and improve the accuracy of the position after movement.

[0108] Reference Fig.16 In some embodiments, the step of S100 includes:

[0109] S301 , controlling the top surface 101 of the pressing member to be 1.5 mm-2 mm lower than the top surface of the housing 22 .

[0110] Combined with reference Fig.11 The distance between the top surface 101 of the pressing member and the top surface of the housing 22 is as follows: Fig.12As shown in H. The distance here can be set according to actual needs, for example, it can be 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm and 2.0mm, or any value between 1.5mm-2mm. If the designed distance is too small, the distance between the welding position of the clamping member 1 and the laser output head 5 will be small, and the clamping member 1 is easy to burn during the welding process; if the designed distance is too large, the clamping member 1 cannot squeeze the outer shell 22 inward at a position close to the top of the outer shell 22, that is, at a position close to the welding point, and there is a greater risk of the outer shell 22 expanding outward.

[0111] In the above embodiment of the present application, by setting the top surface 101 of the clamping member lower than the top surface of the shell 22, and the difference range is 1.5mm-2mm, the risk of laser ablation of the clamping member 1 can be reduced, and the risk of light leakage caused by the outward expansion of the shell 22 can also be reduced.

[0112] In some embodiments, before step S100, the process further includes the following steps:

[0113] The battery cell 20 is driven to rotate, thereby adjusting the welding angle of the battery cell 20 .

[0114] Specifically, the battery cell 20 can be placed on a welding platform 7, and the output shaft of the first driving member 3 is connected to the welding platform 7 to drive the battery cell 20 to rise or fall. However, for welding of the battery cell 20, the battery cell 20 sometimes needs to be rotated, so a rotating member 6 can be provided to be connected to the welding platform 7 to drive the welding platform 7 to rotate, thereby adjusting the angle between the battery cell 20 and the welding output head to achieve functions such as side welding.

[0115] By arranging the battery cell 20 to be rotatable, specifically by driving the welding platform 7 on which the battery cell 20 is mounted to rotate through the rotating member 6, the welding angle between the battery cell 20 and the laser output head 5 can be adjusted, and functions such as side welding can also be achieved.

[0116] According to some embodiments of the present application, the present application provides a battery cell welding method for welding a top cover 21 and an outer shell 22 of a square battery cell, comprising the following steps: driving the battery cell 20 to rise and move to a pre-welding position A, driving two clamping members 1 to move toward two opposite outer side surfaces of the outer shell 22, so that the two clamping members 1 are respectively in contact with two opposite outer side surfaces of the outer shell 22; wherein, a top surface 101 of the clamping member is flush with the top surface of the outer shell 22, and a side of the clamping member 1 close to the outer shell 22 is provided with an avoidance notch 2; pre-welding the top cover 21 and the outer shell 22 at the position of the avoidance notch 2; driving the clamping member 1 to move to a first position C in a direction away from the outer shell 22, driving the battery cell 20 to descend to an initial position, driving the battery cell 20 to rise to a full welding position B, and driving the clamping member 1 to move from the first position C toward the outer shell 22 to abut against the outer side surface of the outer shell 22; wherein, the top surface 101 of the clamping member is 1.5 mm-2 mm lower than the top surface of the outer shell 22; and fully welding the top cover 21 and the outer shell 22. At the same time, the welding angle of the battery cell 20 can also be adjusted by driving the battery cell 20 to rotate. In this embodiment, the avoidance notch 2 is set on the side of the pressing member 1 close to the shell 22, and the pressing member 1 is set to be flush with the top surface of the shell 22 during the pre-welding process, and the top cover 21 and the shell 22 are welded at the position of the shell 22 corresponding to the avoidance notch 2, which can reduce the risk of laser burning the pressing member 1, and can also press the shell 22 from the top of the shell 22, that is, the welding position, thereby reducing the risk of laser burning the diaphragm and causing the battery cell 20 to short-circuit, and can also adjust the welding angle of the battery cell 20.

[0117] Reference Figure 4-Figure 12 ,as well as Fig.17 and Fig.18 According to some embodiments of the present application, the present application provides a battery core welding device for welding the top cover 21 and the shell 22 of the battery core 20, and the battery core welding device includes a first driving member 3, a second driving member 4, a clamping member 1 and a laser output head 5; the output shaft of the second driving member 4 is connected to the clamping member 1, and the side of the clamping member 1 away from the output shaft is provided with an avoidance notch 2; the first driving member 3 is used to drive the battery core 20 to move to the pre-welding position A, and the second driving member 4 is used to drive the clamping member 1 to abut against the shell 22 when the battery core 20 moves to the pre-welding position A, and make the clamping member 1 The top surface 101 of the component is arranged flush with the top surface of the outer shell 22, and the laser output head 5 is used to pre-weld the top cover 21 and the outer shell 22 at the pre-welding position A and the corresponding avoidance gap 2; the first driving component 3 is also used to drive the battery cell 20 to move to the full welding position B, and the second driving component 4 is also used to drive the clamping component 1 to move toward the outer shell 22 to abut against the outer side surface of the outer shell 22 when the battery cell 20 moves to the full welding position B, and make the top surface 101 of the clamping component lower than the top surface of the outer shell 22; the laser output head 5 is used to perform full welding on the top cover 21 and the outer shell 22 at the full welding position B.

[0118] The battery cell 20 includes a top cover 21 and a shell 22. The laser output head 5 is used to emit a laser to weld the top cover 21 and the shell 22. The first driving member 3 is used to drive the battery cell 20 to move toward the direction of the laser output head 5 so that the battery cell 20 is close to the laser output head 5, which is convenient for the laser output head 5 to perform welding later. The pre-welding position A here refers to the position where the laser output head 5 pre-welds the top cover 21 and the shell 22. The pre-welding position A can be the coordinate position set for the battery cell 20 to rise to. When the first driving member 3 drives the battery cell 20 to rise to the preset position, the first driving member 3 temporarily stops working. When the battery cell 20 rises to the pre-welding position A, the second driving member 4 connected to the clamping member 1 drives the clamping member 1 to move toward the shell 22 of the battery cell 20 and abut against it, and the shell 22 is pressed by the clamping member 1, and the clamping member 1 also plays a clamping role.

[0119] The top surface 101 of the clamping piece of the present application is flush with the top surface of the outer shell 22, that is, in the vertical direction or the height direction, the top surface 101 of the clamping piece and the top surface of the outer shell 22 are at the same height. This design is to clamp the top of the outer shell 22 to prevent the outer shell 22 from expanding and deforming outward during welding, which causes a gap between the outer shell 22 and the top cover 21 or increases the gap between the outer shell 22 and the top cover 21, and then causes laser leakage at the gap.

[0120] A relief notch 2 is provided on the pressing member 1, and the relief notch 2 is provided on the side of the pressing member 1 facing the shell 22, so that the shell 22 and the top cover 21 can be pre-welded at the position where the relief notch 2 is located, so that the pressing member 1 will not be burned. It should be noted that the pre-welding here is the preliminary welding of the shell 22 and the top cover 21, and only some point welding of the shell 22 and the top cover 21 is required. In the subsequent full welding, the entire weld is welded at the connection position between the top cover 21 and the shell 22. Therefore, some relief notches 2 can be provided on the side of the pressing member 1 facing the shell 22, and the number of the relief notches 2 can be multiple, and multiple relief notches 2 are provided at intervals on the pressing member 1, and the relief notches 2 are used for pre-welding the laser output head 5 at the corresponding position of the shell 22, and the part of the side of the pressing member 1 abutting against the shell 22 without the relief notch 2 is used to abut against the shell 22, thereby reducing the risk of the shell 22 expanding and deforming outward, so as to reduce the risk of a large gap between the shell 22 and the top cover 21. In this way, the outer shell 22 is pressed, and an escape space is provided on the outer side where the outer shell 22 and the top cover 21 are welded, so as to prevent the pressing part 1 from being ablated by laser during the welding process.

[0121] By setting an avoidance notch 2 on the side of the clamping piece 1 close to the outer shell 22, the clamping piece 1 is set to be flush with the top surface of the outer shell 22 during the pre-welding process, and the top cover 21 and the outer shell 22 are welded at the position of the outer shell 22 corresponding to the avoidance notch 2, the risk of laser burning the clamping piece 1 can be reduced, and the outer shell 22 can be clamped from the top of the outer shell 22, that is, the welding position, thereby reducing the risk of outward expansion of the outer shell 22, resulting in excessive gap between the outer shell 22 and the top cover 21, and thus reducing the possibility of light leakage, thereby reducing the risk of laser burning the diaphragm and causing a short circuit in the battery cell 20.

[0122] Reference Fig.12 and Fig.17 In some embodiments, the battery cell 20 is a square battery cell, the clamping member 1 includes a pressure strip, the number of the second driving member 4 and the clamping member 1 are both two and they are arranged one to one, the two clamping members 1 are respectively arranged on the opposite sides of the square battery cell, and the length of the pressure strip is greater than the length of the top edge of the outer side surface that is in contact with the pressure strip.

[0123] The battery cell 20 is a square battery cell, and the corresponding shell 22 is a square shell. At this time, the number of the clamping members 1 can be two, and the two clamping members 1 respectively clamp the square battery cell from the outer sides where the two long sides of the square shell are located. At this time, the number of the second driving members 4 can be one or two. When the number of the second driving members 4 is one, the two clamping members 1 can be connected by a driving member through a transition structure, so that the two clamping members 1 can move closer to each other or away from each other, clamping the shell 22 when approaching each other, and releasing the shell 22 when moving away from each other. By setting two clamping members 1 to abut against two opposite outer sides, the shell 22 can be subjected to uniform force. When the number of the second driving members 4 is one, a second driving member 4 can be set to be connected to the first clamping member 1 accordingly.

[0124] By setting the number of the pressing members 1 to two, the two pressing members 1 press the outer shell 22 from the two outer sides of the square battery cell outer shell 22 respectively, so that the outer shell 22 is evenly stressed and the clamping is more stable.

[0125] Reference Fig.11 , Fig.12 and Fig.18 In some embodiments, the number of the avoidance gaps 2 is multiple, the avoidance gaps 2 extend to the edge of the pressure strip, and the multiple avoidance gaps 2 are arranged at intervals along the length direction of the pressure strip.

[0126] The length direction of the layering strip can be as follows Fig.12The direction shown by L in the figure. Some avoidance notches 2 are arranged on the side of the clamping member 1 facing the shell 22. The number of avoidance notches 2 can be multiple, and multiple avoidance notches 2 are arranged at intervals on the clamping member 1. The avoidance notches 2 are used for pre-welding the laser output head 5 at the corresponding position of the shell 22, and the part of the side of the clamping member 1 that abuts against the shell 22 without the avoidance notch 2 is used to abut against the shell 22, thereby reducing the risk of the shell 22 expanding and deforming outward, so as to reduce the risk of a large gap between the shell 22 and the top cover 21.

[0127] By setting a plurality of avoidance gaps 2 at intervals, corresponding to the pre-welding position settings of the outer shell 22 and the top cover 21, it is possible to avoid burning the pressure strip during the pre-welding process, and it is also possible to press the outer shell 22 from the top of the outer shell 22, thereby reducing the risk of the outer shell 22 expanding and deforming outward, thereby reducing the risk of the laser entering the interior of the battery cell 20 and causing the battery cell 20 to short-circuit.

[0128] Reference Fig.19 In some embodiments, the battery cell welding device further includes a rotating member 6 and a welding platform 7 , the battery cell 20 is mounted on the welding platform 7 , and the rotating member 6 is connected to the welding platform 7 .

[0129] Specifically, the battery cell 20 can be placed on a welding platform 7, and the output shaft of the first driving member 3 is connected to the welding platform 7 to drive the battery cell 20 to rise or fall. However, for welding of the battery cell 20, the battery cell 20 sometimes needs to be rotated, so a rotating member 6 can be provided to be connected to the welding platform 7 to drive the welding platform 7 to rotate, thereby adjusting the angle between the battery cell 20 and the welding output head to achieve functions such as side welding.

[0130] By arranging the battery cell 20 to be rotatable, specifically by driving the welding platform 7 on which the battery cell 20 is mounted to rotate through the rotating member 6, the welding angle between the battery cell 20 and the laser output head 5 can be adjusted, and functions such as side welding can also be achieved.

[0131] In some embodiments, the first driving member 3 includes a servo motor, and the servo motor is used to drive the battery cell 20 to move.

[0132] The servo motor can realize precise control of the movement stroke of the battery cell 20, move the battery cell 20 between the pre-welding position A, the initial position and the full welding position B, and can realize rising and falling, which is conducive to moving the battery cell 20 to various positions. Similarly, the second driving member 4 and the rotating member 6 can also be servo motors, and the servo motors are used to realize precise control of the position and rotation angle. In a further embodiment, the first driving member 3 also includes a lifting module, and the welding platform 7 can be installed on the lifting module, and the servo motor drives the welding platform 7 to perform lifting movement through the driving module. Of course, a pad 8 can also be provided, and the pad 8 can be installed on the welding platform 7, and the battery cell 20 is placed on the pad 8 to adapt to the welding of battery cells 20 of different heights.

[0133] By adopting a servo motor, the position of the battery cell 20 can be accurately controlled, thereby improving the reliability of welding.

[0134] In some embodiments, the laser output head 5 is a swing output head.

[0135] Compared with the traditional laser output head 5, the swing output head has an additional light splitting component inside, which can also be called a micro-galvanometer, which can be directly installed on the original laser output head 5 to achieve welding swing. Specifically, the welding of the traditional laser output head 5 can only perform linear welding, while the swing output head can achieve a circular shape of the welding line in a small range, such as Fig. 20 As shown in the figure, a circle of circular welding wires forms a weld. Fig. 20 As shown in D, compared with a straight weld, the weld width can be increased to form a larger weld pool, thereby covering a larger gap. Of course, it can also be an 8-shaped or other shape. The weld pool can cover a larger gap, which reduces the risk of the laser penetrating through the gap into the battery cell 20, thereby reducing the risk of the battery cell 20 short-circuiting.

[0136] By adopting a swinging output head, welding swing can be achieved, the welding width can be increased, and a larger welding molten pool can be formed, thereby reducing the risk of laser passing through the gap between the top cover 21 and the outer shell 22 and reducing the risk of short circuit of the battery cell 20.

[0137] According to some embodiments of the present application, the present application provides a battery cell welding device for welding a top cover 21 and an outer shell 22 of a square battery cell, the battery cell welding device includes a first driving member 3, a second driving member 4, a clamping member 1, a rotating member 6 and a laser output head 5, the laser output head 5 is a swinging output head, which can increase the welding width and thereby increase the molten pool area; the output shaft of the second driving member 4 is connected to the clamping member 1, and a plurality of avoidance gaps 2 are provided on the side of the clamping member 1 away from the output shaft, the avoidance gaps 2 extend to the edge of the pressure strip, and the plurality of avoidance gaps 2 are arranged at intervals along the extension direction of the outer shell 22; the first driving member 3 is used to drive the battery cell 20 to move to the pre-welding position A, and the second driving member 4 is used to move the battery cell 20 to the pre-welding position A, the clamping piece 1 is driven to abut against the outer shell 22, and the top surface 101 of the clamping piece is set flush with the top surface of the outer shell 22, and the laser output head 5 is used to pre-weld the top cover 21 and the outer shell 22 at the pre-welding position A and corresponding to the avoidance gap 2; the first driving member 3 is also used to drive the battery cell 20 to move to the full welding position B, and the second driving member 4 is also used to drive the clamping piece 1 to move toward the outer shell 22 and abut against the outer side surface of the outer shell 22 when the battery cell 20 moves to the full welding position B, and the top surface 101 of the clamping piece is set lower than the top surface of the outer shell 22; the laser output head 5 is used to fully weld the top cover 21 and the outer shell 22 at the full welding position B, and the rotating member 6 can drive the battery cell 20 to rotate through the welding platform 7 to adjust the welding angle. This embodiment can not only reduce the risk of laser burning the clamping piece 1, but also can press the outer shell 22 from the top of the outer shell 22, that is, the welding position, thereby reducing the risk of the outer shell 22 expanding outward, resulting in an excessively large gap between the outer shell 22 and the top cover 21, thereby reducing the possibility of light leakage, and further reducing the risk of laser burning the diaphragm and causing a short circuit in the battery cell 20.

[0138] The above description is only an optional embodiment of the present application, and does not limit the patent scope of the present application. All equivalent structural changes made by using the contents of the present application specification and drawings under the application concept of the present application, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present application.

Claims

1. A battery core welding method for welding a top cover and a shell of a battery core, characterized in that: The following steps are involved: The battery cell is driven to rise and move to the pre-welding position, and the pressing piece is driven to move to abut against the outer side surface of the shell; wherein the top surface of the pressing piece is arranged flush with the top surface of the shell, and a side of the pressing piece close to the shell is provided with an avoidance notch; Pre-welding the top cover and the outer shell at the avoidance notch position; The pressing member is driven to move to a first position in a direction away from the housing, the battery cell is driven to move to a full welding position, and the pressing member is driven to move from the first position toward the housing to abut against an outer side surface of the housing; wherein the top surface of the pressing member is lower than the top surface of the housing; The top cover and the outer shell are fully welded.

2. The battery core welding method according to claim 1, characterized in that: The pressing member is a pressure strip, and the step of driving the pressing member to move to abut against the outer side surface of the housing comprises: The side of the pressure strip provided with the avoidance notch is arranged toward the shell, and the pressure strip is driven to move until it is completely in contact with the outer side surface of the shell, and the length of the pressure strip is greater than the length of the top edge of the outer side surface in contact with the pressure strip.

3. The battery core welding method according to claim 1, characterized in that: The battery cell is a square battery cell, the number of the pressing members is two, and the two pressing members are respectively arranged on two opposite sides of the square battery cell, and the step of driving the pressing members to move to abut against the outer side surface of the housing comprises: The two pressing members are driven to move toward two opposite outer side surfaces of the shell, so that the two pressing members are respectively in contact with two opposite outer side surfaces of the shell.

4. The battery core welding method according to claim 1, characterized in that: The step of driving the battery cell to move to the full welding position comprises: Driving the battery cell to descend to an initial position; The battery cell is driven to rise to a full welding position, and the top cover and the outer shell are fully welded.

5. The battery core welding method according to any one of claims 1 to 4, characterized in that: The step of providing the top surface of the pressing member to be lower than the top surface of the housing comprises: The top surface of the pressing member is controlled to be 1.5 mm to 2 mm lower than the top surface of the shell.

6. The battery core welding method according to any one of claims 1 to 4, characterized in that: Before the step of driving the pressing member to move to abut against the outer side surface of the housing, the step further includes: The battery core is driven to rotate, thereby adjusting the welding angle of the battery core.

7. A battery core welding device for welding the top cover and the shell of the battery core, characterized in that: The battery core welding device comprises a first driving member, a second driving member, a pressing member and a laser output head; The output shaft of the second driving member is connected to the pressing member, and a side of the pressing member facing away from the output shaft is provided with an avoidance notch; The first driving member is used to drive the battery cell to move to the pre-welding position, and the second driving member is used to drive the pressing member to abut against the shell when the battery cell moves to the pre-welding position, so that the top surface of the pressing member is flush with the top surface of the shell, and the laser output head is used to pre-weld the top cover and the shell at the pre-welding position and corresponding to the avoidance notch; The first driving member is also used to drive the battery cell to move to a full welding position, and the second driving member is also used to drive the clamping member to move toward the outer shell until it abuts against the outer side surface of the outer shell when the battery cell moves to the full welding position, and make the top surface of the clamping member lower than the top surface of the outer shell; the laser output head is used to fully weld the top cover and the outer shell at the full welding position.

8. The electric core welding equipment according to claim 7, characterized in that: The battery cell is a square battery cell, the clamping piece includes a pressure strip, the number of the second driving piece and the clamping piece are both two and they are arranged in one-to-one correspondence, the two clamping pieces are respectively arranged on two opposite sides of the square battery cell, and the length of the pressure strip is greater than the length of the top edge of the outer side surface that is in contact with the pressure strip.

9. The electric core welding equipment according to claim 8, characterized in that: The number of the avoidance gaps is multiple, and the avoidance gaps extend to the edge of the pressure strip, and the multiple avoidance gaps are arranged at intervals along the length direction of the pressure strip.

10. The electric core welding equipment according to claim 7, characterized in that: The laser output head is a swing output head.

11. The electric core welding device according to claim 7, characterized in that: The battery core welding equipment further comprises a rotating member and a welding platform, the battery core is mounted on the welding platform, and the rotating member is drivingly connected to the welding platform.

12. The electric core welding device according to any one of claims 7 to 11, characterized in that: The first driving member includes a servo motor, and the servo motor is used to drive the battery core to move.

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