A lithium battery tab welding mark leveling process and device

Abstract

The present invention discloses a lithium battery tab welding and leveling process and device, which relates to the technical field of lithium battery tabs, and includes a fixing frame, a side plate, a first reserved groove, a telescopic cylinder, a first fixed roller, a second fixed roller and a fixing frame, wherein the side plates are welded to both sides of the fixing frame, the first reserved groove is opened in the side wall of the side plate, and the fixing frame is arranged inside the first reserved groove; the present invention can compact and level the battery core tabs of the lithium battery pack to avoid wrinkles or unevenness of the tabs of the battery core, the first telescopic spring can reduce the impact when the second fixing plate and the first fixing plate contact, and prevent the battery pack from being squeezed and damaged, the fixing nail can punch the tabs, thereby punching the battery tabs while ensuring the flatness of the battery pack tabs, the battery pack enters between the pressing plates, the pressing plates can clamp the battery pack, and can accurately place the tabs of the battery pack between the first fixing plate and the second fixing plate.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium battery tabs, and in particular to a lithium battery tab welding mark leveling process and device. Background Art

[0002] The weld mark after lithium battery tab welding refers to the welding trace or welding mark formed after the welding is completed due to the requirements of the welding process. In the lithium battery manufacturing process, lithium battery tabs are generally laser welded. The laser beam is used to heat the tabs, melt them and connect them to the busbar. Tab welding is a key process. The tab is the key part connecting the positive and negative poles in the lithium battery. It is responsible for transmitting current to the outside of the battery cell. The quality of welding is directly related to the performance and safety of the battery.

[0003] In the existing technology, the battery tabs are welded during laser welding. The weld marks of lithium batteries after welding are uneven, which reduces the performance of the lithium battery. It is easy for the tabs to be poorly connected, which affects the safety of the battery pack. Lithium batteries generate some gas during use. When gas is generated due to chemical reactions inside the battery or the internal pressure rises due to temperature increase, there is no air release channel in the exhaust hole. The gas in the PP glue covering layer of the tab is not easy to discharge. When the internal pressure of the battery exceeds the safe range, bulging is easy to occur. When reaching a certain capacity, it may even cause the battery to explode. In addition, in the flattening processing technology, the tabs at the welding point need to be adjusted according to the situation of the weld mark during welding, otherwise the air holes at the welding imprint will not be easy to discharge. Summary of the Invention

[0004] The object of the present invention is to provide a process and device for leveling the welding marks of lithium battery tabs to solve the problems raised in the above background technology.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A lithium battery tab welding mark leveling process and device, comprising a fixing frame, a side plate, a first reserved groove, a telescopic cylinder, a first fixed roller, a second fixed roller and a fixed frame, wherein the side plate is welded to both sides of the fixing frame, the first reserved groove is opened in the side wall of the side plate, the fixed frame is arranged inside the first reserved groove, the fixed frame is slidably connected to the first reserved groove, the telescopic cylinder is arranged at the top of the side plate, the first fixed roller is arranged between the two fixed frames, the second fixed roller is arranged between the bottom ends of the two side plates, and the first fixed roller and the second fixed roller rotate in opposite directions when in contact; a leveling structure is arranged between the first fixed roller and the second fixed roller, and the leveling structure includes The first fixing sleeve is provided at both ends of the first fixing roller, a third fixing plate is welded between the two first fixing sleeves, a second fixing plate is provided below the third fixing plate, a fixing bolt is connected between the second fixing plate and the third fixing plate, both ends of the second fixing roller are provided with a second fixing sleeve, the first fixing plate is welded between the two second fixing sleeves, the position of the first fixing plate corresponds to the position of the second fixing plate, the two ends of the first fixing plate and the third fixing plate are connected by a guide rod, the guide rod is slidably connected to the two ends of the third fixing plate, the second fixing plate and the third fixing plate are synchronously lifted and lowered with the first fixing roller, and the first fixing plate and the second fixing plate are used to level the lithium battery ears.

[0007] As a preferred technical solution of the present invention, the cylindrical surfaces of the first fixed roller and the second fixed roller are both provided with corresponding second reserved grooves, and the mating surfaces of the second fixed plate and the first fixed plate are both provided with corresponding first fixed grooves.

[0008] As a preferred technical solution of the present invention, the position of the second reserved groove corresponds to the position of the first fixed groove, and the gap between the second reserved grooves of the first fixed roller and the second fixed roller is the same as the gap between the first fixed plate and the second fixed plate, and the second reserved groove and the first fixed groove are both used for conveying lithium battery cells.

[0009] As a preferred technical solution of the present invention, a row of stepped holes is provided inside the third fixed plate, the fixing bolts are slidably connected to the stepped holes, the ends of the fixing bolts are screwed into the second fixed plate, a first telescopic spring is provided inside the stepped holes, and the fixing bolts pass through the axis of the first telescopic spring, and the second fixed plate and the third fixed plate are close to or away from each other.

[0010] As a preferred technical solution of the present invention, connecting rods that cross each other are provided between the two ends of the first fixed plate and the two ends of the second fixed plate, and both ends of the connecting rods are movably connected to the fixing pins. Sliding grooves are provided at both ends of the first fixed plate and the second fixed plate, and the fixing pins and the sliding grooves are slidably connected inside, so that the first fixed plate and the second fixed plate approach or move away from each other.

[0011] As a preferred technical solution of the present invention, a placement groove is provided on the surface of the first fixing plate and located on one side of the first fixing groove, a placement plate is placed inside the placement groove, and a plurality of fixing nails are integrally provided on the surface of the placement plate, and the fixing nails are used to drill exhaust holes in the tabs of the sodium battery.

[0012] As a preferred technical solution of the present invention, a clamping structure is provided between the first fixed plate and the third fixed plate, and the clamping structure includes two groups of second fixed grooves, which are respectively opened on the upper surface of the first fixed plate and the lower surface of the second fixed plate, and a plurality of second telescopic springs are connected to the inside of each second fixed groove. A first pressing plate is provided on the surface of the first fixed groove of the first fixed plate, and a second pressing plate is provided on the surface of the first fixed groove of the second fixed plate. The first pressing plate is connected to the second telescopic spring of the first fixed plate, and the second pressing plate is connected to the second telescopic spring of the second fixed plate. The first pressing plate and the second pressing plate are used to clamp the battery pack.

[0013] As a preferred technical solution of the present invention, a guide groove is provided on the edge of the first fixing groove, and a guide plate is integrally manufactured on the edge of the first clamping plate. The guide plate is aligned with the guide groove, and the guide plate is used to introduce the lithium battery pack between the first clamping plate and the guide plate.

[0014] A process for leveling the welding marks of lithium battery tabs, used in the processing of the device for leveling the welding marks of lithium battery tabs, comprises the following steps:

[0015] Step 1: Preparation: Clean the battery cells and tabs to ensure they are free of oil, dust and other debris. Calibrate the laser welding equipment and set the appropriate power, speed and focus position.

[0016] Step 2: Weld the tabs of the lithium battery. Align the battery cell with the tabs and start the laser welding machine. Align the laser beam at the connection between the tabs and the battery cell to heat and melt the weld. Then, sandwich the metal strip between two pieces of film.

[0017] Step 3: Weld mark leveling. After welding is completed, weld marks will appear on the surface of the weld point. The first fixed roller and the second fixed roller of the lithium battery tab weld mark leveling device are used to level the tab.

[0018] Step 4: Arrange the layout of the fixing pins as needed to press the vent holes, use the first fixing plate and the second fixing plate to flatten the tabs again, and use the fixing pins to punch holes while flattening the tabs, and press the vent holes on the surface of the battery tabs below the film;

[0019] Step 5: After leveling, set an explosion-proof membrane between the exhaust hole and the PP glue. When the sodium ion battery discharges gas, the gas can be discharged through the explosion-proof membrane, while the outside gas cannot enter the explosion-proof membrane;

[0020] Step 6: Inspection and testing: Perform a visual inspection of the welding area to ensure that the solder joints are flat and firm, and detect the internal resistance of the solder joints to ensure that the welding quality meets the standards.

[0021] As a preferred technical solution of the present invention, the battery core of the lithium battery in step three is located in the second reserved groove, and the battery core moves along the second reserved groove and the first fixed groove, the first clamping plate and the second clamping plate are used to clamp the battery core between the two clamping plates, and the battery tab is located between the first fixed plate and the second fixed plate.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] A flattening structure is provided, and the battery tabs of the lithium battery pack can be compacted and flattened by closing the first and second fixing plates to prevent the tabs of the battery core from being wrinkled or uneven. A first telescopic spring is located between the second and third fixing plates. The first telescopic spring can reduce the impact when the second fixing plate and the first fixing plate contact each other, preventing the battery pack from being squeezed and damaged;

[0024] By deforming the connecting rod of the flat structure, when the fixing pins at the ends of the connecting rod are located at both ends of the sliding groove, the movement distance of the second fixing plate can be limited, thereby preventing the battery pack from being separated from the first fixing groove or the second reserved groove due to excessive distance between the first fixing plate and the second fixing plate;

[0025] A fixing nail is provided. When the first fixing plate and the second fixing plate are fitted together, the fixing nail can punch a hole in the tab between the first fixing plate and the second fixing plate, thereby punching a hole in the battery tab while ensuring that the tab of the battery pack is flat;

[0026] A clamping structure is provided, and the guide plate can guide the battery pack into the first clamping plate, and the battery pack enters between the first clamping plate and the second clamping plate. The clamping plate can clamp the battery pack and can accurately place the tabs of the battery pack between the first fixing plate and the second fixing plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] To facilitate understanding by those skilled in the art, the present invention is further described below with reference to the accompanying drawings.

[0028] Figure 1 It is the main structure diagram of the present invention;

[0029] Figure 2 It is a schematic diagram of the flat structure of the present invention;

[0030] Figure 3 This is a schematic diagram of the first fixing plate and the second fixing plate in the separated state of the present invention;

[0031] Figure 4This is a schematic diagram of the fixing bolt and the first telescopic spring of the present invention;

[0032] Figure 5 is a schematic diagram of the first fixing groove of the present invention;

[0033] Figure 6 This is a schematic diagram of the connecting rod connection of the present invention;

[0034] Figure 7 A schematic diagram of a fixing nail of the present invention;

[0035] Figure 8 It is a schematic diagram of the clamping structure of the present invention;

[0036] Figure 9 Schematic diagram of the second telescopic spring of the present invention.

[0037] In the figure: 1. fixed frame; 2. side plate; 3. first reserved groove; 4. telescopic cylinder; 5. first fixed roller; 6. second fixed roller; 7. leveling structure; 8. clamping structure; 9. fixed frame; 71. first fixed plate; 72. second fixed plate; 73. third fixed plate; 74. fixing bolt; 75. first fixed sleeve; 76. second fixed sleeve; 77. guide rod; 78. second reserved groove; 79. first fixed groove; 710. connecting rod; 711. fixing pin; 712. sliding groove; 713. stepped hole; 714. first telescopic spring; 715. placement groove; 716. placement plate; 717. fixing nail; 81. guide groove; 82. first clamping plate; 83. guide plate; 84. second clamping plate; 85. second fixed groove; 86. second telescopic spring. DETAILED DESCRIPTION

[0038] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0039] Example 1:

[0040] See also Figure 1-Figure 2As shown, a lithium battery tab welding and leveling process and device includes a fixing frame 1, a side plate 2, a first reserved groove 3, a telescopic cylinder 4, a first fixed roller 5, a second fixed roller 6 and a fixed frame 9. The side plates 2 are welded to both sides of the fixing frame 1, and the side plates 2 on both sides of the fixing frame 1 are arranged in parallel. The first reserved groove 3 is opened on the side wall of the side plate 2, and the fixed frame 9 is arranged inside the first reserved groove 3. The fixed frame 9 is slidably connected to the first reserved groove 3. The telescopic cylinder 4 is set at the top of the side plate 2, and the telescopic cylinder 4 is installed at the top of the side plate 2, so that the end of the telescopic cylinder 4 is fixed to the fixed frame 9. When the telescopic cylinder 4 is extended and retracted, the two fixed frames 9 can be lifted and lowered along the inside of the first reserved groove 3. The first fixed The roller 5 is arranged between the two fixed frames 9, and the second fixed roller 6 is arranged between the bottom ends of the two side plates 2. The first fixed roller 5 and the second fixed roller 6 rotate in opposite directions when they are in contact. When the first fixed roller 5 is raised, the first fixed roller 5 and the second fixed roller 6 can be separated. When the first fixed roller 5 is lowered, the first fixed roller 5 and the second fixed roller 6 can be in contact. A driving motor is provided on one side of the second fixed roller 6, and the driving motor drives the second fixed roller 6 to rotate, so that the rotation of the second fixed roller 6 drives the first fixed roller 5 to rotate; a leveling structure 7 is provided between the first fixed roller 5 and the second fixed roller 6, and the leveling structure 7 includes a first fixed sleeve 75 provided at both ends of the first fixed roller 5, and two second fixed rollers 75 provided at both ends of the first fixed roller 5. A third fixing plate 73 is welded between a fixing sleeve 75, a second fixing plate 72 is provided below the third fixing plate 73, and a fixing bolt 74 is connected between the second fixing plate 72 and the third fixing plate 73. When the first fixing roller 5 is lifted or lowered, the third fixing plate 73 and the second fixing plate 72 can be driven to lift or lower. Similarly, the first fixing roller 5 rotates relative to the first fixing sleeve 75. Both ends of the second fixing roller 6 are sleeved with a second fixing sleeve 76. A first fixing plate 71 is welded between the two second fixing sleeves 76. The bottom end of the first fixing plate 71 is fixed to the fixing frame 1 through a connecting block. The position of the second fixing roller 6 is fixed relative to the position of the first fixing plate 71, and the position of the first fixing plate 71 is fixed relative to the position of the second fixing plate 72. Correspondingly, the two ends of the first fixed plate 71 and the third fixed plate 73 are connected by a guide rod 77, and the guide rod 77 is slidably connected to the two ends of the third fixed plate 73. The second fixed plate 72 and the third fixed plate 73 are both raised and lowered synchronously with the first fixed roller 5. The first fixed plate 71 and the second fixed plate 72 are used to flatten the lithium battery tabs. Since the first fixed roller 5 moves away from or approaches the second fixed roller 6, the first fixed plate 71 moves away from or approaches the third fixed plate 73, so that the position of the third fixed plate 73 will only move up and down without position deviation. When the first fixed plate 71 and the second fixed plate 72 are close to each other, the battery cell tabs of the lithium battery pack can be compacted and flattened to avoid wrinkles or unevenness of the battery cell tabs.

[0041] See also Figure 2 and Figure 5As shown, the cylindrical surface of the first fixed roller 5 and the cylindrical surface of the second fixed roller 6 are both provided with second reserved grooves 78 corresponding to each other, and the contact surfaces of the second fixed plate 72 and the first fixed plate 71 are both provided with first fixed grooves 79 corresponding to each other; the position of the second reserved groove 78 corresponds to the position of the first fixed groove 79, and the gap between the second reserved grooves 78 of the first fixed roller 5 and the second fixed roller 6 is the same as the gap between the first fixed plate 71 and the first fixed groove 79 of the second fixed plate 72, and the gap between the second reserved grooves 78 of the first fixed roller 5 and the second fixed roller 6 is the same as the gap between the first fixed roller 5 and the second fixed roller 6. The gap spacing matches the thickness of the battery pack. The gap of the first fixed groove 79 between the first fixed plate 71 and the second fixed plate 72 is adapted to the thickness of the battery pack. The second reserved groove 78 and the first fixed groove 79 are both used for conveying lithium battery cells. While the first fixed roller 5 and the second fixed roller 6 rotate relative to each other, the battery pack is pushed by the two second reserved grooves 78, so that the battery pack moves along the second reserved groove 78 and the first fixed groove 79, and enters the first fixed groove 79 of the first fixed plate 71 and the second fixed plate 72 to continue moving.

[0042] See also Figure 3 and Figure 4 When the first and third fixing plates 71 and 73 are in a closed position, the locking cam 73 is engaged with the first fixing plate 72 and the locking cam 73 is engaged with the locking cam 73.

[0043] See also Figure 2-Figure 6As shown, connecting rods 710 that cross each other are provided between the two ends of the first fixing plate 71 and the two ends of the second fixing plate 72, and the two ends of the connecting rods 710 are movably connected to the fixing pins 711. The first fixing plate 71 and the second fixing plate 72 are provided with sliding grooves 712 at both ends. The fixing pins 711 and the sliding grooves 712 are internally slidably connected, and the first fixing plate 71 and the second fixing plate 72 approach or move away from each other. When the first fixing plate 71 and the third fixing plate 73 approach each other, the two connecting rods 710 evolve, so that the fixing pins 711 move along the sliding grooves 712 to ensure that the two fixing plates approach or move away. The fixing pins 711 of the connecting rods 710 are located in the sliding grooves 712 and move to limit the positions of the first fixing plate 71 and the second fixing plate 72.

[0044] See also Figure 2 and Figure 7 As shown, a placement groove 715 is provided on the surface of the first fixing plate 71 and on one side of the first fixing groove 79. A placement plate 716 is placed inside the placement groove 715. The placement plate 716 is placed inside the placement groove 715. A plurality of fixing pins 717 are integrally provided on the surface of the placement plate 716. The fixing pins 717 are used to drill exhaust holes for the tabs of the sodium battery. The top ends of the fixing pins 717 of the placement plate 716 are in contact with the lower surface of the second fixing plate 72, so that the fixing pins 717 can imprint the tabs of the battery pack, and the exhaust holes are pressed on the surface of the battery tabs under the film.

[0045] It should be noted that when the tabs of the lithium battery need to be welded to the inside of the battery core, the welding needs to be stamped at the tabs, which can be achieved by extending the length of the telescopic cylinder 4. At this time, the telescopic cylinder 4 pushes the fixed frame 9 to descend along the first reserved groove 3, so that the first fixed roller 5 and the second fixed roller 6 are close to each other, and the driving motor rotates the second fixed roller 6 so that the second fixed roller 6 and the first fixed roller 5 rotate, and the battery pack is transported to the second reserved groove 78 of the first fixed roller 5 and the second fixed roller 6 through the conveyor belt, thereby transporting the lithium battery to the first fixed plate 71 and the second fixed plate 72, and the lithium The battery pack enters the first fixing groove 79 of the first fixing plate 71 and the second fixing plate 72, so that the lithium batteries are successively pushed into the first fixing groove 79 by the following lithium battery pack. The first fixing sleeve 75 drives the lower end of the third fixing plate 73 to move, and the third fixing plate 73 and the second fixing plate 72 descend synchronously, so that the second fixing plate 72 first contacts the first fixing plate 71, and the third fixing plate 73 continues to descend so that the third fixing plate 73 contacts the second fixing plate 72. The first telescopic spring 714 can be used to reduce the impact of the second fixing plate 72, so as to flatten and press the tabs of the battery pack.

[0046] When the second fixing plate 72 and the first fixing plate 71 are completely closed, the connecting rod 710 is deformed so that the fixing pin 711 at the end of the connecting rod 710 moves along the sliding groove 712, so that the fixing pin 711 moves along the inside of the sliding groove 712. The positions of the first fixing plate 71 and the second fixing plate 72 can be limited to prevent the first fixing plate 71 and the second fixing plate 72 from moving beyond the limit position. When the third fixing plate 73 is away from the first fixing plate 71, it can also prevent the first fixing plate 71 and the second fixing plate 72 from moving beyond the limit position.

[0047] Before the first fixing plate 71 and the second fixing plate 72 are fitted together, the lithium battery is located between the first fixing plate 71 and the second fixing plate 72, and the fixing pins 717 of the placement plate 716 can be set as needed. The pole ears of the battery pack will be located in the placement grooves 715. When the first fixing plate 71 and the second fixing plate 72 are closed, the fixing pins 717 of the placement plate 716 will punch holes in the pole ears of the battery pack. The battery pack can be moved when the first fixing roller 5 and the second fixing roller 6 move. Since the second fixing plate 72 can float, it will not affect the movement of the battery pack from the second reserved groove 78 and the first fixing groove 79.

[0048] See also Figure 2 and Figure 8 As shown, a clamping structure 8 is provided between the first fixing plate 71 and the third fixing plate 73. The clamping structure 8 includes two groups of second fixing grooves 85. The two groups of second fixing grooves 85 are respectively opened on the upper surface of the first fixing plate 71 and the lower surface of the second fixing plate 72. A plurality of second telescopic springs 86 are connected to the interior of each second fixing groove 85. A first pressing plate 82 is provided on the surface of the first fixing groove 79 of the first fixing plate 71. The second telescopic springs 86 inside the first fixing plate 71 can push the first pressing plate 82 to move. A second pressing plate 84 is provided on the surface of the first fixing groove 79 of the second fixing plate 72. The first pressing plate 82 is connected to the second telescopic spring 86 of the first fixed plate 71, and the second pressing plate 84 is connected to the second telescopic spring 86 of the second fixed plate 72. The second telescopic spring 86 inside the second fixed plate 72 can push the second pressing plate 84 to move. The first pressing plate 82 and the second pressing plate 84 are used to clamp the battery pack. The first pressing plate 82 and the second pressing plate 84 that are close to each other are close to each other, so that the battery pack can be moved from the second reserved groove 78 to the first fixed groove 79, so that the moved battery pack is clamped between the first pressing plate 82 and the second pressing plate 84.

[0049] See also Figure 8 and Figure 9As shown, a guide groove 81 is formed on the edge of the first fixing groove 79. The guide groove 81 is arranged at an angle so that the battery pack can smoothly enter the first fixing groove 79. A guide plate 83 is integrally manufactured on the edge of the first pressing plate 82. The guide plate 83 is aligned with the guide groove 81. When the guide plate 83 is raised or lowered, the first fixing groove 79 can be attached or closed. The guide plate 83 is used to guide the lithium battery pack between the first pressing plate 82 and the guide plate 83.

[0050] It should be noted that the tabs of the battery pack can be squeezed by the cylindrical contact of the first fixed roller 5 and the second fixed roller 6, and the second reserved groove 78 can push the interior of the battery pack, and the battery pack enters the first fixed groove 79 from the second reserved groove 78. At this time, the battery pack uses the guide plate 83 to enter between the first clamping plate 82 and the second clamping plate 84.

[0051] A process for leveling the welding marks of lithium battery tabs, used in the manufacture of a device for leveling the welding marks of lithium battery tabs, comprises the following steps:

[0052] Step 1: Preparation work, clean the battery cells and tabs to ensure that there is no oil, dust and other debris, calibrate the laser welding equipment, set the appropriate power, speed and focus position. In the lithium battery tab welding mark leveling process, the cleaning work is to ensure the cleanliness of the welding area. If there is oil, dust and other debris on the battery cells and tabs, it may cause poor welding, such as the formation of cold welding, weak solder joints and other problems. Cleaning is usually carried out using professional solvents or cleaning equipment to ensure that the welding surface is free of impurities. In the high-precision welding process, after cleaning, it is necessary to check to ensure that the surface of the battery cells and tabs is completely clean, without oil, dust and other debris that may affect the welding quality. It is necessary to check whether the various parameters of the equipment are accurate, including the shape of the laser beam, the focus position, etc. The welding speed is too fast, which may lead to insufficient welding and weak solder joints. The speed is too slow, which may cause overheating and affect the performance of the battery cells. The welding speed needs to be adjusted according to the actual situation.

[0053] Step 2: Weld the tabs of the lithium battery. After aligning the battery cell with the tabs, start the laser welding machine. Align the laser beam at the connection between the tabs and the battery cell to heat and melt the weld. Then sandwich the metal strip between two pieces of film for one tab. Place the prepared tab at the welding position of the battery cell. Use laser welding to weld the metal strip of the tab to the positive and negative electrodes of the battery cell. Control the parameters of the welding process, such as power, speed, time, etc., to ensure the quality of welding. The film is the insulating part of the tab structure, usually made of plastic or other insulating materials. Their main function is to insulate and fix the metal strip to prevent the metal strip from direct contact with other parts of the battery cell to avoid short circuit or leakage. The metal strip is the conductive part of the tab, used to draw current from the battery cell. In the manufacturing process of the tab, two pieces of film-like film sandwich the metal strip. The metal strip is placed on one piece of film and the other piece of film covers the metal strip. The film and the metal strip are bonded together by heating or other means to form a stable whole.

[0054] Step 3: Weld mark leveling. After welding is completed, weld marks will appear on the surface of the weld. The first fixed roller 5 and the second fixed roller 6 of the lithium battery tab weld mark leveling device are used to level the tab. The battery core of the lithium battery is located at the second reserved groove 78, and the battery core moves along the second reserved groove 78 and the first fixed groove 79. The first pressing plate 82 and the second pressing plate 84 are used to clamp the battery core between the two pressing plates, and the battery tab is located between the first fixed plate 71 and the second fixed plate 72. Leveling the weld mark after the lithium battery is welded can improve the aesthetics, ensure good contact and prevent short circuits, enhance welding strength and improve reliability. The weld mark leveling process plays an important role in improving the performance, reliability and safety of lithium batteries.

[0055] Step 4: Arrange the layout of the fixing pins 717 as needed to suppress the exhaust holes, use the first fixing plate 71 and the second fixing plate 72 to flatten the tabs again, and use the fixing pins 717 to punch holes while flattening the tabs. Press the exhaust holes on the surface of the battery tabs below the film. Pressing the exhaust holes can release pressure. When gas is generated due to chemical reactions inside the battery or the internal pressure rises due to temperature increase, the exhaust holes can serve as channels for pressure release to prevent explosions caused by excessive internal pressure in the battery. Gas is released through the exhaust holes to reduce the internal pressure of the battery, thereby reducing the risk of battery shell rupture caused by excessive pressure. The exhaust holes can be pressed on the battery shell according to the arrangement of the fixing pins 717 to ensure that the size, shape and position of the holes meet the design requirements.

[0056] Step 5: After leveling, set an explosion-proof membrane between the exhaust hole and the PP glue. When the sodium ion battery discharges gas, the gas can be discharged through the explosion-proof membrane. At the same time, the external gas cannot enter the explosion-proof membrane. The explosion-proof membrane is set to prevent explosion. When the internal pressure of the battery exceeds the safe range, the explosion-proof membrane will rupture, thereby releasing the internal pressure to prevent the battery shell from exploding due to excessive pressure. Through the effect of the explosion-proof membrane, even if an abnormal reaction occurs inside the battery, the risk of injury to the user can be effectively reduced. When the explosion-proof membrane is specifically implemented, the explosion-proof membrane is usually made of special plastic materials, such as polyethylene or polypropylene. These materials have sufficient strength and flexibility. During the battery packaging process, the explosion-proof membrane is firmly fixed to the battery shell by hot pressing or other means to ensure that it will not fall off or be damaged under normal use conditions;

[0057] Step 6: Inspection and testing: Perform a visual inspection of the welding area to ensure that the solder joints are flat and firm, and detect the internal resistance of the solder joints to ensure that the welding quality meets the standards.

[0058] The preferred embodiments of the present invention disclosed above are intended only to help illustrate the present invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the present invention to specific embodiments. Obviously, many modifications and variations are possible based on the contents of this specification. These embodiments are selected and described in detail in this specification to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A device for leveling the welding marks of lithium battery tabs, comprising a fixing frame (1), a side plate (2), a first reserved groove (3), a telescopic cylinder (4), a first fixed roller (5), a second fixed roller (6) and a fixed frame (9), wherein the side plate (2) is welded to both sides of the fixing frame (1), the first reserved groove (3) is opened on the side wall of the side plate (2), the fixed frame (9) is arranged inside the first reserved groove (3), the fixed frame (9) is slidably connected to the first reserved groove (3), the telescopic cylinder (4) is arranged at the top of the side plate (2), the first fixed roller (5) is arranged between the two fixed frames (9), the second fixed roller (6) is arranged between the bottom ends of the two side plates (2), and the first fixed roller (5) and the second fixed roller (6) rotate in opposite directions when in contact; characterized in that A leveling structure (7) is provided between the first fixed roller (5) and the second fixed roller (6), the leveling structure (7) comprising first fixed sleeves (75) provided at both ends of the first fixed roller (5), a third fixed plate (73) welded between the two first fixed sleeves (75), a second fixed plate (72) provided below the third fixed plate (73), a fixing bolt (74) connected between the second fixed plate (72) and the third fixed plate (73), and second fixed sleeves (76) provided at both ends of the second fixed roller (6). A first fixing plate (71) is welded between the two second fixing sleeves (76), the position of the first fixing plate (71) corresponds to the position of the second fixing plate (72), the two ends of the first fixing plate (71) and the third fixing plate (73) are connected by a guide rod (77), the guide rod (77) and the two ends of the third fixing plate (73) are slidably connected, the second fixing plate (72) and the third fixing plate (73) are synchronously lifted and lowered with the first fixing roller (5), and the first fixing plate (71) and the second fixing plate (72) are used to flatten the lithium battery tabs; The cylindrical surface of the first fixed roller (5) and the cylindrical surface of the second fixed roller (6) are both provided with second reserved grooves (78) corresponding to each other, and the mating surfaces of the second fixed plate (72) and the first fixed plate (71) are both provided with first fixed grooves (79) corresponding to each other; Connecting rods (710) that cross each other are provided between the two ends of the first fixing plate (71) and the two ends of the second fixing plate (72), and both ends of the connecting rods (710) are movably connected to fixing pins (711). Sliding grooves (712) are provided at both ends of the first fixing plate (71) and the second fixing plate (72), and the fixing pins (711) and the sliding grooves (712) are internally slidably connected, so that the first fixing plate (71) and the second fixing plate (72) move closer to or farther away from each other. A placement groove (715) is provided on the surface of the first fixing plate (71) and located on one side of the first fixing groove (79). A placement plate (716) is placed inside the placement groove (715). A plurality of fixing nails (717) are integrally provided on the surface of the placement plate (716). The fixing nails (717) are used to drill exhaust holes in the tabs of the lithium battery.

2. The device for leveling the welding marks of the lithium battery tabs according to claim 1, characterized in that: The position of the second reserved groove (78) corresponds to the position of the first fixed groove (79), and the gap between the second reserved groove (78) of the first fixed roller (5) and the second fixed roller (6) is the same as the gap between the first fixed plate (71) and the second fixed plate (72), and the second reserved groove (78) and the first fixed groove (79) are both used for conveying lithium battery cells.

3. The device for leveling the welding marks of the lithium battery tabs according to claim 2, characterized in that: A row of stepped holes (713) is provided inside the third fixing plate (73), a fixing bolt (74) is slidably connected to the stepped holes (713), an end of the fixing bolt (74) is screwed into the second fixing plate (72), a first telescopic spring (714) is provided inside the stepped hole (713), and the fixing bolt (74) passes through the axis of the first telescopic spring (714), and the second fixing plate (72) and the third fixing plate (73) are moved closer to or farther away from each other.

4. The device for leveling the welding marks of the lithium battery tabs according to claim 3, characterized in that: A clamping structure (8) is provided between the first fixing plate (71) and the third fixing plate (73), and the clamping structure (8) includes two groups of second fixing grooves (85), which are respectively opened on the upper surface of the first fixing plate (71) and the lower surface of the second fixing plate (72). A plurality of second telescopic springs (86) are connected inside each second fixing groove (85). A first pressing plate (82) is provided on the surface of the first fixing groove (79) of the first fixing plate (71), and a second pressing plate (84) is provided on the surface of the first fixing groove (79) of the second fixing plate (72). The first pressing plate (82) is connected to the second telescopic spring (86) of the first fixing plate (71), and the second pressing plate (84) is connected to the second telescopic spring (86) of the second fixing plate (72). The first pressing plate (82) and the second pressing plate (84) are used to clamp the battery pack.

5. The device for leveling the welding marks of the lithium battery tabs according to claim 4, characterized in that: A guide groove (81) is formed at the edge of the first fixing groove (79), and a guide plate (83) is integrally manufactured at the edge of the first pressing plate (82). The guide plate (83) is aligned with the guide groove (81), and the guide plate (83) is used to guide the lithium battery pack between the first pressing plate (82) and the guide plate (83).

6. A process for leveling the welding marks of lithium battery tabs, applied to the device for leveling the welding marks of lithium battery tabs according to claim 5, characterized in that: The following steps are involved: Step 1: Preparation: Clean the battery cells and tabs to ensure they are free of oil, dust and other debris. Calibrate the laser welding equipment and set the appropriate power, speed and focus position. Step 2: Weld the tabs of the lithium battery. Align the battery cell with the tabs and start the laser welding machine. Align the laser beam at the connection between the tabs and the battery cell to heat and melt the weld. Then, sandwich the metal strip between two pieces of film. Step 3: Weld mark leveling: after welding is completed, a weld mark will appear on the surface of the weld spot, and the tab is leveled by the first fixed roller (5) and the second fixed roller (6) of the lithium battery tab weld mark leveling device; Step 4: Arrange the layout of the fixing pins (717) as needed to press the vent holes, use the first fixing plate (71) and the second fixing plate (72) to flatten the tabs again, and use the fixing pins (717) to punch holes while flattening the tabs, and press the vent holes on the surface of the battery tabs below the film; Step 5: After leveling, set an explosion-proof membrane between the exhaust hole and the PP glue. When the lithium-ion battery discharges gas, the gas can be discharged through the explosion-proof membrane, while the outside gas cannot enter the explosion-proof membrane; Step 6: Inspection and testing: Perform a visual inspection of the welding area to ensure that the solder joints are flat and firm, and detect the internal resistance of the solder joints to ensure that the welding quality meets the standards.

7. The process for leveling the welding mark of the lithium battery tab according to claim 6, characterized in that: In step 3, the battery core of the lithium battery is located at the second reserved groove (78), and the battery core moves along the second reserved groove (78) and the first fixed groove (79), the first pressing plate (82) and the second pressing plate (84) are used to clamp the battery core between the two pressing plates, and the battery tab is located between the first fixed plate (71) and the second fixed plate (72).

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