Lithium ion battery spot welding machines play a crucial role in the battery manufacturing industry, and their welding quality directly affects the performance and safety of batteries. So, how to ensure the firmness of lithium-ion battery spot welding machine welding?
1、 Choose the appropriate soldering pin
Choosing the appropriate welding needle is the foundation for ensuring welding firmness. The model and specifications of the welding needle should be selected based on the thickness of the nickel sheet and the process design requirements of the battery pack. Here are several commonly used soldering pins and their characteristics:
1. 1.7 Straight through soldering pin: This is the most commonly used soldering pin model with good versatility, suitable for nickel sheets ranging from 0.12mm to 0.18mm. Its diameter is moderate, with good conductivity and heat dissipation, making it suitable for welding various types of battery packs.
2. 3.0 Eccentric Spot Welding Needle: The front end is usually converted to 1.7/2.0 for use. Because the welding needle is thick, it can weld thicker nickel sheets. The conventional welding thickness of nickel sheets is between 0.15-2.0mm. This type of welding needle is suitable for welding large or high-strength battery packs.
3. 6.0 Convex spot welding needle: Usually used for welding convex nickel sheets. For products with high quality requirements for battery packs, battery packs that often generate vibration or impact, or battery packs with excessive current overload, convex nickel sheet welding can be used.

2、 Ensure the welding process is standardized
In addition to selecting the appropriate welding needle, ensuring the standardization of the welding process is also the key to ensuring the firmness of the welding. Here are a few key points to note:
1. Uniform distribution of solder joints: The solder joints should be evenly distributed between the nickel sheet and the battery cell, avoiding solder misalignment or solder joints between the gaps of the positive and negative electrodes. This can ensure the firmness and stability of the welding.
2. Moderate number of welding points: Welding battery packs is usually done twice, forming four welding points. Avoid virtual soldering of solder joints and reduce the probability of virtual soldering. Multiple solder joints have better conductivity and higher stability, but for general battery pack welding, four solder joints are sufficient. The number of solder joints depends on the requirements of the battery pack process design.
3. Keep clean: During the welding process, ensure that there are no other impurities remaining on the surface of the nickel sheet and battery cell, otherwise welding defects such as explosion may occur.

3、 Pay attention to equipment operation and maintenance
Equipment operation and maintenance are also important factors in ensuring welding firmness. Here are a few key points to note:
1. Safe operation: Before using a lithium battery spot welding machine, ensure that you understand and comply with relevant safety operating procedures, including wearing personal protective equipment (such as goggles, gloves) and correctly using the equipment's switches and buttons.
2. Correct connection: Connect the lithium battery correctly to the spot welding machine, ensuring that the positive and negative electrodes are in close contact with metal materials such as electrode heads or connecting pieces. Pay attention to the stability of the connection to avoid weak welding.
3. Parameter setting: Set appropriate welding parameters based on specific welding requirements, such as welding current, time, etc. Ensure that the parameter settings are correct to avoid poor welding quality or damage to the lithium battery.
4. Regular inspection and maintenance: Regularly inspect and maintain the spot welding machine, including cleaning the equipment, replacing worn parts, etc. This can ensure the normal operation of the equipment and welding quality.
Choosing the appropriate welding needle, ensuring the welding process is standardized, and paying attention to equipment operation and maintenance are the three key points to ensure the welding firmness of lithium-ion battery spot welding machines. Only by doing all three aspects well can we ensure that the welding quality reaches the best state, providing strong guarantees for the performance and safety of the battery.