Today, with the vigorous development of the lithium battery industry, the lithium spot welding machine has become an indispensable key equipment in the lithium battery manufacturing process. It plays a crucial role in improving the performance and quality of lithium batteries, whether it is the connection between the electrode sheet and the pole ear, or the various welding needs in the battery assembly process, all rely on the precise operation of the lithium spot welder.
1、Connection between lithium battery production process and spot welding machine
(1) The basic composition and production steps of lithium batteries
Lithium battery is mainly composed of positive electrode, negative electrode, diaphragm and electrolyte. Its production is a complex multi-step process, including electrode preparation, cell assembly, liquid injection and formation. In electrode preparation, the active material, conductive agent and binder are mixed and coated on the collector to form an electrode sheet. In the cell assembly process, the positive and negative electrode sheets and the diaphragm are arranged in a specific order, which is the key to ensure the performance of the cell, and the lithium spot welding machine plays a core role here.
(2) The key position of the spot welding machine in the production process
In the entire lithium battery production process, the lithium spot welding machine participates in a number of key connection links. From the connection between the electrode sheet and the pole ear, to the connection between the multiple layers of electrodes and other components in the cell assembly, the spot welding machine is like a bridge, connecting the various components closely to ensure good electrical conduction and structural stability inside the battery.
2、the working principle of lithium spot welding machine
(1) Resistance spot welding principle
Lithium spot welding machine uses resistance spot welding principle. When the current passes through the workpiece to be welded, due to the large resistance at the workpiece contact point, the heat generated by the current will accumulate in this area. With the continuous accumulation of heat, the temperature of the metal material at the contact point rapidly rises to the melting point, and under the pressure exerted by the electrode, a solid solder joint is formed between the weldparts. The precise control of electrode pressure, current size and power on time is the basis of high quality welding in lithium spot welding machine.
(2) Precise control of welding energy
In the process of lithium battery welding, the control of welding energy is very important. If the energy is too high, it may damage the electrode material, diaphragm, etc., affect the battery performance, and even bring safety risks. On the contrary, insufficient energy can not form a reliable solder joint, affecting the electrical connection and mechanical stability of the battery. Lithium spot welding machine with advanced circuit and control system, can accurately adjust the current, voltage and time, so as to achieve fine control of welding energy.
3、the role of lithium spot welding machine in the production of lithium batteries
(1) Connection guarantee between electrode sheet and pole ear
Ensure quality electrical connections
The quality of the connection between the electrode sheet and the pole ear directly affects the charge-discharge performance of the battery. The lithium spot welding machine ensures a low-resistance electrical connection between the two by forming a high-quality solder joint. It is of great significance to reduce the energy loss in charge and discharge process. For example, in lithium batteries for electric vehicles, good electrical connections can improve battery charging and discharging efficiency and increase vehicle driving range.
Enhanced connection strength
During the life cycle of the battery, the electrode sheet and the pole ear will be subjected to mechanical stress such as vibration and impact. The solder joint formed by the lithium electric spot welding machine has high strength and can withstand these external forces to prevent the connection from loosening or breaking. In safety-critical lithium battery applications in the aerospace sector, this robust connection ensures reliable operation of the battery in complex and harsh environments.
(2) The key role of battery assembly
The multi-layer electrodes are securely connected
When the cell is assembled, multiple layers of positive and negative electrode sheets need to be connected together. Lithium spot welding can quickly and accurately form solder joints between each layer of electrodes to ensure good electrical conductivity between electrodes and the overall structure of the cell is stable. In the winding cell, it can spot weld uniformly along the winding direction to avoid delamination or electrode displacement in the long-term use of the cell.
Reliable connection to other components
In addition to the electrode plate connection, the cell assembly also involves the connection of other components such as the connection plate. The lithium spot welding machine can adapt to the connection parts of different shapes and materials, and connect them firmly through precise spot welding, laying a stable structural foundation for the subsequent processing and use of the battery cell.
(3) Improve battery safety and stability
Effective protection against short circuit
The precise spot welding of the lithium spot welding machine can ensure that the size, shape and position of the solder joints meet the design requirements, so as to effectively prevent short circuit of the positive and negative electrodes due to improper welding. Short circuit is an important cause of lithium battery safety accidents, which may lead to overheating, fire and even explosion of the battery. High-quality spot welding can reduce such risks and ensure the safety of battery use.
Improve battery consistency
In the mass production of lithium batteries, battery consistency is crucial to battery pack performance. The lithium spot welding function ensures that the quality of each solder joint is stable, so that the electrical performance and mechanical strength of the internal connection of each battery are similar, thereby improving the consistency of the batteries in the battery pack and improving the overall performance and life of the battery pack.
5、the characteristics and advantages of lithium spot welding machine
(1) High-precision welding parameter control
Precise current control
Lithium spot welding machine has high precision current control ability, accurate to milliamperes and even smaller units. This enables it to adjust the current according to the specific situation when welding electrode materials of different materials and thicknesses to achieve the best welding effect. For example, for the new high energy density lithium battery electrode material, it is highly sensitive to current, and high-precision current control can avoid damage to the material due to current fluctuations.
Precise control of time and pressure
In addition to the current, the welding time and electrode pressure are also precisely controlled. Precise time control ensures that the solder joint is formed at the right time to avoid over-heating or under-welding. The appropriate electrode pressure can make the weldment fully contact and form a dense solder joint. This multi-parameter high precision control is the key to ensure the quality of welding.
(2) Adapt to a variety of materials and shapes
Extensive material adaptability
Lithium spot welding machine can adapt to the common lithium battery production of copper, aluminum, nickel and other metal materials. Different metal materials have different physical properties, spot welding function adjusts welding parameters according to its conductivity, melting point, hardness and other characteristics to achieve effective welding. For example, when welding aluminum pole ears, the surface oxide layer can be penetrated to achieve good welding.
Good shape adaptability
In the production of lithium batteries, the electrode sheet, the pole ear and the connecting sheet have various shapes, such as sheet, column, strip and so on. The electrode design of lithium spot welding machine is flexible, can be adjusted according to different shapes, and form high-quality solder joints between various shapes, whether it is plane and plane or plane and surface welding can cope with freely.
5、Conclusion
The lithium spot welding machine occupies a core position in the manufacturing of lithium batteries, which plays a key role in the high-quality completion of the electrode plate and the pole ear connection, the cell assembly and other links, ensuring the safety, performance and consistency of the battery. Its characteristics of high-precision parameter control, material shape adaptability and efficient and stable performance make it a key equipment for lithium battery production.
