Lithium battery tab welding mark leveling process and device

Abstract

The invention discloses a lithium battery pole lug welding mark leveling process and device, and relates to the technical field of lithium battery pole lugs, the lithium battery pole lug welding mark leveling device comprises a fixing frame, side plates, first reserved grooves, telescopic air cylinders, a first fixing roller, a second fixing roller and a fixing frame, the side plates are welded to the two sides of the fixing frame, the first reserved grooves are formed in the side walls of the side plates, and the second reserved grooves are formed in the side walls of the side plates; the fixed frame is arranged in the first reserved groove; the lithium battery pack tab compacting and flattening device can compact and flatten a battery cell tab of a lithium battery pack, the tab of the battery cell is prevented from being wrinkled or unflattened, a first telescopic spring can reduce impact generated when a second fixing plate makes contact with a first fixing plate, the battery pack is prevented from being extruded and damaged, the tab can be punched through a fixing nail, and the battery pack is prevented from being damaged. The first fixing plate and the second fixing plate are used for fixing the tabs of the battery pack, so that the tabs of the battery pack are punched while flatness of the tabs of the battery pack is guaranteed, the battery pack enters the space between the pressing plates, the pressing plates can clamp the battery pack, and the tabs of the battery pack can be accurately placed between the first fixing plate and the second fixing plate.

Description

Technical Field

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

[0002] The welding mark after the lithium battery tab welding refers to the welding traces or welding marks formed after the welding is completed due to the requirements of the welding process. In the lithium battery manufacturing process, the lithium battery tabs are generally laser welded, and the laser beam is used to heat the tabs to melt them and connect them to the busbar. Tab welding is a key process. The tab is the key part of the lithium battery that connects the positive and negative electrodes. It is responsible for transferring 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 prior art, the battery's pole ears are welded during laser welding. The weld marks of lithium batteries after welding are uneven, which reduces the performance of lithium batteries. It is easy for the pole ears to be poorly connected when 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 channel for releasing air through the exhaust hole. The gas in the PP glue covering layer of the pole ears is not easy to discharge. When the internal pressure of the battery exceeds the safe range, bulging is likely to occur. When reaching a certain capacity, it may even cause the battery to explode. In addition, in the flattening process, the pole ears at the welding point need to be adjusted according to the situation of the welding mark during welding, otherwise the air holes at the welding stamping point are not easy to discharge. Summary of the invention

[0004] The object of the present invention is to provide a lithium battery tab welding mark leveling process and device 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 and 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 with 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 present invention comprises a first fixing sleeve arranged 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 arranged below the third fixing plate, a fixing bolt is connected between the second fixing plate and the third fixing plate, second fixing sleeves are arranged at both ends of the second fixing roller, 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, both ends of the first fixing plate and the third fixing plate are connected by a guide rod, the guide rod is slidably connected to both ends of the third fixing plate, the second fixing plate and the third fixing plate are both lifted and lowered synchronously with the first fixing roller, and the first fixing plate and the second fixing plate are used to flatten the lithium battery pole 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 opened inside the third fixed plate, the fixing bolts are slidably connected to the stepped holes, the ends of the fixing bolts are screwed with the second fixed plate, the first telescopic spring is arranged 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, mutually intersecting connecting rods are arranged between the two ends of the first fixed plate and the two ends of the second fixed plate, and the two 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 are slidably connected inside the sliding grooves, so that the first fixed plate and the second fixed plate are close to or 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 for the pole ears of the sodium battery.

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

[0013] As a preferred technical solution of the present invention, a guide groove is provided at the edge of the first fixing groove, and a guide plate is integrally manufactured at 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 mark of a lithium battery tab, used in the processing of the device for leveling the welding mark of a lithium battery tab, 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 to the connection between the tabs and the battery cell to heat and melt the weld. Then sandwich the metal strip between two films through one tab.

[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 exhaust 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 exhaust holes on the surface of the battery tabs under 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, and the external 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 at 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 core tabs of the lithium battery pack can be compacted and flattened by closing the first fixing plate and the second fixing plate to avoid wrinkles or unevenness of the battery core tabs. The first telescopic spring is located between the second fixing plate and the third fixing plate. The first telescopic spring can reduce the impact when the second fixing plate and the first fixing plate are in contact, and prevent 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 the two ends of the sliding groove, the moving 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 the 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 pole ear between the first fixing plate and the second fixing plate, thereby punching a hole in the battery pole ear while ensuring that the pole ear of the battery pack is flat;

[0026] A clamping structure is provided, and the guide plate can guide the battery pack to 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 pole ear of the battery pack between the first fixing plate and the second fixing plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order 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 flattening structure of the present invention;

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

[0031] Figure 4It 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 a first fixing groove of the present invention;

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

[0034] Figure 7 It is 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] Fig. 9 It is a 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, flat 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 solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] Embodiment 1:

[0040] See also Figure 1-Figure 2As shown, a lithium battery ear welding mark leveling process and device comprises 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, 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, the fixed frame 9 is arranged inside the first reserved groove 3, the fixed frame 9 is slidably connected with the first reserved groove 3, the telescopic cylinder 4 is arranged at the top of the side plate 2, 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, and the two fixed frames 9 can be lifted and lowered along the inside of the first reserved groove 3 when the telescopic cylinder 4 is extended and retracted. 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. When the first fixed roller 5 and the second fixed roller 6 are in contact, the rotation directions are opposite. 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 arranged 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 arranged between the first fixed roller 5 and the second fixed roller 6, and the leveling structure 7 includes a first fixed sleeve 75 arranged at both ends of the first fixed roller 5, and two second fixed rollers 75 are provided. A third fixing plate 73 is welded between the first and second fixing sleeves 75, a second fixing plate 72 is arranged below the third fixing plate 73, a fixing bolt 74 is connected between the second fixing plate 72 and the third fixing plate 73, and the third fixing plate 73 and the second fixing plate 72 can be driven to be lifted and lowered when the first fixing roller 5 is lifted and lowered, and similarly the first fixing roller 5 rotates relative to the first fixing sleeve 75, and second fixing sleeves 76 are sleeved at both ends of the second fixing roller 6, a first fixing plate 71 is welded between the two second fixing sleeves 76, and 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 relatively fixed to the position of the first fixing plate 71, and the position of the first fixing plate 71 is relatively fixed 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 lifted and lowered synchronously with the first fixed roller 5. The first fixed plate 71 and the second fixed plate 72 are used to level the lithium battery ears. As 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 ears of the lithium battery pack can be compacted and leveled to avoid wrinkles or unevenness of the battery cell ears.

[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 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 matches 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, and the battery pack is pushed by the two second reserved grooves 78 while the first fixed roller 5 and the second fixed roller 6 rotate relative to each other, 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 and continues to move.

[0042] See also Figure 3 and Figure 4 As shown, a row of stepped holes 713 are provided inside the third fixing plate 73, and the fixing bolts 74 are slidably connected with the stepped holes 713. The ends of the fixing bolts 74 are screwed with the second fixing plate 72. The third fixing plate 73 rises and falls with the first fixing sleeve 75, so that the third fixing plate 73 and the second fixing plate 72 also rise and fall synchronously. The first fixing plate 71 and the second fixing plate 72 can clamp the battery pack in the middle, and the first fixing plate 71 and the second fixing plate 72 also press the pole ears of the battery pack. The first telescopic spring 714 is provided inside the stepped hole 713, and the fixing bolts 74 pass through the axis of the first telescopic spring 714. The second fixing plate 72 and the third fixing plate 73 approach or move away from each other. When the first fixing plate 71 and the third fixing plate 73 approach each other, the second fixing plate 72 is ensured to be closely close to the first fixing plate 71, and the second fixing plate 72 is pressed by the first telescopic spring 714. When the second fixing plate 72 is closed, the impact of the second fixing plate 72 is reduced.

[0043] See also Figure 2-Figure 6As shown, connecting rods 710 that cross each other are arranged 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, and the fixing pins 711 and the sliding grooves 712 are internally slidably connected. 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, so as 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 located on one side of the first fixing groove 79, and a placement plate 716 is placed inside the placement groove 715. The placement plate 716 is placed inside the placement groove 715, and 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 for the pole ears of the sodium battery. The top ends of the fixing nails 717 of the placement plate 716 are in contact with the lower surface of the second fixing plate 72, so that the fixing nails 717 can stamp the pole ears of the battery pack, and the exhaust holes are pressed on the surface of the battery pole ears under the film.

[0045] It should be noted that when the pole ear of the lithium battery needs to be welded, the pole ear needs to be welded inside the battery core. If the welding needs to be stamped at the pole ear, the length of the telescopic cylinder 4 can be extended. At this time, the telescopic cylinder 4 pushes the fixed frame 9 to be lowered 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, so that the lithium battery is transported 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 battery is pushed into the first fixing groove 79 by the rear lithium battery pack, and 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, wherein 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 pole ear 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 attached, 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 at 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, 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, and a plurality of second telescopic springs 86 are connected inside each second fixing groove 85, and a first clamping plate 82 is provided on the surface of the first fixing groove 79 of the first fixing plate 71, and the second telescopic springs 86 inside the first fixing plate 71 can push the first clamping plate 82 to move, and a second clamping plate 84 is provided on the surface of the first fixing groove 79 of the second fixing plate 72. The first clamping plate 82 is connected to the second telescopic spring 86 of the first fixed plate 71, and the second clamping 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 clamping plate 84 to move. The first clamping plate 82 and the second clamping plate 84 are used to clamp the battery pack. The first clamping plate 82 and the second clamping 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 battery pack is clamped between the first clamping plate 82 and the second clamping plate 84.

[0049] See also Figure 8 and Fig. 9As shown, a guide groove 81 is provided at the edge of the first fixing groove 79, and the guide groove 81 is arranged obliquely so that the battery pack can smoothly enter the first fixing groove 79. A guide plate 83 is integrally manufactured at the edge of the first clamping plate 82, and 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 clamping plate 82 and the guide plate 83.

[0050] It should be noted that the pole ears of the battery pack can be squeezed by the contact of the cylindrical surfaces 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 mark of a lithium battery tab, used in the processing of a lithium battery tab welding mark leveling device, 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 are oil, dust and other debris on the battery cells and tabs, it may cause poor welding, such as the formation of cold welding, loose 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. Check whether the various parameters of the equipment are accurate, including the shape of the laser beam, the focus position, etc. Welding too fast may result in insufficient welding and loose solder joints. Welding too slowly may cause overheating, affecting 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. Align the battery cell with the tabs and start the laser welding machine. Align the laser beam to the connection between the tabs and the battery cell to heat and melt the weld. 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 plates of the battery cell. Control the parameters in the welding process, such as power, speed, time, etc., to ensure the welding quality. 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 directly contacting other parts of the battery cell to avoid short circuit or leakage. The metal strip is the conductive part of the tab, which is used to draw current from the battery cell. In the manufacturing process of the tab, two film-like films sandwich the metal strip. The metal strip is placed on one film, and the other 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: Welding mark leveling. After welding is completed, welding marks will appear on the surface of the welding spot. The first fixed roller 5 and the second fixed roller 6 of the lithium battery pole ear welding mark leveling device are used to level the pole ear. 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 clamping plate 82 and the second clamping plate 84 are used to clamp the battery core between the two clamping plates, and the battery pole ear is located between the first fixed plate 71 and the second fixed plate 72. After the lithium battery is welded, the welding mark is leveled to improve the aesthetics, ensure good contact and prevent short circuits, enhance welding strength and improve reliability. The welding 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 pole ear again, and use the fixing pins 717 to punch holes while flattening the pole ear. Exhaust holes are pressed on the surface of the battery pole ear 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 be used as a channel 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 pressed on the battery shell can be changed 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, and 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 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 only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to only specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. 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) is welded between the two first fixed sleeves (75), a second fixed plate (72) is provided below the third fixed plate (73), a fixing bolt (74) is connected between the second fixed plate (72) and the third fixed plate (73), and second fixed sleeves (76) are 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 both slidably connected, the second fixing plate (72) and the third fixing plate (73) are both lifted and lowered synchronously 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 pole ears.

2. The device for leveling the welding marks of the lithium battery tabs according to claim 1, characterized in that: 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.

3. The device for leveling the welding marks of the lithium battery tabs according to claim 2, 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.

4. The device for leveling the welding marks of lithium battery tabs according to claim 3, 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 with 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 close to or away from each other.

5. The device for leveling the welding marks of the lithium battery tabs according to claim 4, characterized in that: Connecting rods (710) that cross each other are arranged between the two ends of the first fixing plate (71) and the two ends of the second fixing plate (72); both ends of the connecting rods (710) are movably connected to fixing pins (711); both ends of the first fixing plate (71) and the second fixing plate (72) are provided with sliding grooves (712); 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) are moved closer to or farther away from each other.

6. The device for leveling the welding marks of lithium battery tabs according to claim 5, characterized in that: 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 for the tabs of the sodium battery.

7. The device for leveling the welding marks of the lithium battery tabs according to claim 6, 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), 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), and a plurality of second telescopic springs (86) are connected inside each second fixing groove (85). A first clamping plate (82) is provided on the surface of the first fixing groove (79) of the first fixing plate (71), and a second clamping plate (84) is provided on the surface of the first fixing groove (79) of the second fixing plate (72). The first clamping plate (82) is connected to the second telescopic spring (86) of the first fixing plate (71), and the second clamping plate (84) is connected to the second telescopic spring (86) of the second fixing plate (72). The first clamping plate (82) and the second clamping plate (84) are used to clamp the battery pack.

8. The device for leveling the welding marks of lithium battery tabs according to claim 7, 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 clamping 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 clamping plate (82) and the guide plate (83).

9. A process for leveling the welding mark of a lithium battery tab, applied to the device for leveling the welding mark of a lithium battery tab as claimed in any one of claims 1 to 8, 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 to the connection between the tabs and the battery cell to heat and melt the weld. Then sandwich the metal strip between two films through one tab. Step 3: Weld mark leveling: after welding is completed, weld marks will appear on the surface of the weld point, and the pole ear is leveled by the first fixed roller (5) and the second fixed roller (6) of the lithium battery pole ear weld mark leveling device; Step 4: Arrange the layout of the fixing pins (717) as needed to press 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, and press the exhaust 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 sodium ion battery discharges gas, the gas can be discharged through the explosion-proof membrane, and the external 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.

10. A lithium battery tab welding and leveling process according to claim 9, characterized in that: In the step three, 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 clamping plate (82) and the second clamping plate (84) are used to clamp the battery core between the two clamping plates, and the battery tab is located between the first fixed plate (71) and the second fixed plate (72).

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