Power lithium -ion battery laser welding process -Lithium - Ion Battery Equipment
The reasonable selection of the welding method and process of the power lithium battery manufacturing process will directly affect the cost, quality, safety, and the consistency of the battery. Next, sort out the content of power lithium battery welding.
1 Laser welding principle
Laser welding uses the excellent directionality and high power density of laser beam to work. Through the optical system, the laser beam is focused in a small area. Areas to melt the welding and form a solid welding joint and welded seams.
2 laser welding type
Hot -conducting welding and deep melting welding
Thermal conductive welding, laser beams melt the cooperation on the appearance of the workpiece along the joints, and the melting flows flow to together and solidify together to form a weld. It is important for relatively thin materials. The maximum welding depth of the material is constrained by its thermal conductivity, and the weld width is always greater than the welding depth.
Deep melting welding, when high -power laser is gathered to the metal appearance, the heat is too late to dispel, and the welding depth will deepen sharply. This welding technology is deep melting welding. Because deep -melting welding technology has a very fast processing speed, the heat impact area is small, and the distortion is minimized. Therefore, this technology can be used to demand deep welding or several layers of data welded together.(Lithium - Ion Battery Equipment)
The important difference between thermal conductivity welding and deep melting welding is that the power density applied to the metal surface during the unit time is different, and different metals have different boundaries.
Through welding and sewing welding
Throbic welding, no punching is required, and the processing is relatively simple. Putting through the laser welding machine with a large power. The melting depth of penetrating welding is lower than the melting depth of the seam welding, and the reliability is relatively almost.
Compared with penetrating welding, sewing welding only requires a smaller power laser welding machine. The melting depth of sewing welding is higher than the melting depth of penetrating welding, and the reliability is relatively good. However, connecting films need to be flushed, and processing is relatively difficult.
Pulse welding and continuous welding
1) Pulse mode welding
When laser welding, the appropriate welding waveform should be selected. The pulse waveforms are commonly used in square waves, peak waves, double peak waves, etc. The reflectivity of the aluminum alloy surface is too high. 60%-98%of laser energy lost due to reflection, and the reflectance changes with the surface temperature. Generally, when welding aluminum alloys, the best choice of pointed waves and double peak waves. This kind of welding waveform slowly reduces part of the pulse width and can effectively reduce the emergence of pores and cracks.
Pulse laser welding sample
Due to the high reflectivity of the laser aluminum alloy, the laser focusing mirror is damaged in order to prevent the vertical reflection of the laser beam from vertical reflection. The diameter of the welding point diameter and effective binding surface increases with the laser increasing angle. When the laser tilt angle is 40, the largest solder joint and effective binding surface are obtained. The welding point melting depth and effective melting depth decrease with the laser tilting angle. When it is greater than 60, the effective welding depth is reduced to zero. Therefore, to a certain angle, the welded seams can be appropriately added to the depth and width of the weld.
In addition, when welding, the weld is bounded, and the laser spots need to be welded by 65%and 35%of the shell.
2) Continuous mode welding
Continuous laser welding is not obvious when the heating process is not like a pulse machine, and the crack tendency is not obvious during welding. In order to improve the quality of the weld, continuous laser welding is used. No crack was found. In terms of welding of aluminum alloy, the advantages of continuous laser are obvious. Compared with traditional welding methods, production efficiency is high and does not need to be filled with wire. Compared with pulse laser welding Pole holes, splashing, etc., ensure that aluminum alloy has good mechanical performance after welding; it will not be sunken after welding, the polishing and polishing amount after welding will be reduced, saving production costs, but because the light spots of continuous laser are relatively small, the assembly accuracy of the workpiece is the accuracy of the workpiece. High requirements.
1 Laser welding principle
Laser welding uses the excellent directionality and high power density of laser beam to work. Through the optical system, the laser beam is focused in a small area. Areas to melt the welding and form a solid welding joint and welded seams.
2 laser welding type
Hot -conducting welding and deep melting welding
Thermal conductive welding, laser beams melt the cooperation on the appearance of the workpiece along the joints, and the melting flows flow to together and solidify together to form a weld. It is important for relatively thin materials. The maximum welding depth of the material is constrained by its thermal conductivity, and the weld width is always greater than the welding depth.
Deep melting welding, when high -power laser is gathered to the metal appearance, the heat is too late to dispel, and the welding depth will deepen sharply. This welding technology is deep melting welding. Because deep -melting welding technology has a very fast processing speed, the heat impact area is small, and the distortion is minimized. Therefore, this technology can be used to demand deep welding or several layers of data welded together.(Lithium - Ion Battery Equipment)
The important difference between thermal conductivity welding and deep melting welding is that the power density applied to the metal surface during the unit time is different, and different metals have different boundaries.
Through welding and sewing welding
Throbic welding, no punching is required, and the processing is relatively simple. Putting through the laser welding machine with a large power. The melting depth of penetrating welding is lower than the melting depth of the seam welding, and the reliability is relatively almost.
Compared with penetrating welding, sewing welding only requires a smaller power laser welding machine. The melting depth of sewing welding is higher than the melting depth of penetrating welding, and the reliability is relatively good. However, connecting films need to be flushed, and processing is relatively difficult.
Pulse welding and continuous welding
1) Pulse mode welding
When laser welding, the appropriate welding waveform should be selected. The pulse waveforms are commonly used in square waves, peak waves, double peak waves, etc. The reflectivity of the aluminum alloy surface is too high. 60%-98%of laser energy lost due to reflection, and the reflectance changes with the surface temperature. Generally, when welding aluminum alloys, the best choice of pointed waves and double peak waves. This kind of welding waveform slowly reduces part of the pulse width and can effectively reduce the emergence of pores and cracks.
Pulse laser welding sample
Due to the high reflectivity of the laser aluminum alloy, the laser focusing mirror is damaged in order to prevent the vertical reflection of the laser beam from vertical reflection. The diameter of the welding point diameter and effective binding surface increases with the laser increasing angle. When the laser tilt angle is 40, the largest solder joint and effective binding surface are obtained. The welding point melting depth and effective melting depth decrease with the laser tilting angle. When it is greater than 60, the effective welding depth is reduced to zero. Therefore, to a certain angle, the welded seams can be appropriately added to the depth and width of the weld.
In addition, when welding, the weld is bounded, and the laser spots need to be welded by 65%and 35%of the shell.
2) Continuous mode welding
Continuous laser welding is not obvious when the heating process is not like a pulse machine, and the crack tendency is not obvious during welding. In order to improve the quality of the weld, continuous laser welding is used. No crack was found. In terms of welding of aluminum alloy, the advantages of continuous laser are obvious. Compared with traditional welding methods, production efficiency is high and does not need to be filled with wire. Compared with pulse laser welding Pole holes, splashing, etc., ensure that aluminum alloy has good mechanical performance after welding; it will not be sunken after welding, the polishing and polishing amount after welding will be reduced, saving production costs, but because the light spots of continuous laser are relatively small, the assembly accuracy of the workpiece is the accuracy of the workpiece. High requirements.
