Lithium battery spot welding machine is a device used for spot welding and connecting components such as battery cells, connectors, and leads in lithium batteries. The working principle is basically to use resistance heating to generate a certain amount of heat between the connecting components, causing them to melt instantly and produce welded joints. The following are the basic steps of the working principle of a lithium battery spot welding machine:

1. Current control: Lithium battery spot welding machine controls the heat of welding by controlling the magnitude and time of the current. Pulse current is usually used for spot welding, and the magnitude and pulse width of the current will be adjusted according to different welding requirements.

2. Contact electrode: The electrode of a spot welding machine (usually made of copper) will be in close contact with the surface of the component to be welded, forming an electrical circuit. This circuit will create resistance between the electrode and the component to be welded, thereby generating heat.

3. Heating: When current flows between the electrode and the component to be welded, heat is generated in the welding area. This heat will rapidly heat the metal in contact to the melting temperature, forming a small area of liquid metal.

4. Pressure application: While heating, the spot welding machine also applies a certain amount of pressure. This pressure helps ensure good contact between the welded components and enables the liquid metal area to be evenly distributed and form a stable welded joint.

5. Cooling: After welding is completed, the current stops and the welding area begins to cool down. As the temperature decreases, the liquid metal region gradually solidifies into a solid welded joint.

6. Welding completion: After cooling, the welding joint is formed, and the connecting components are firmly fixed together, completing the welding process.

In general, the lithium battery spot welding machine generates heat through resistance heating, combined with appropriate pressure and control parameters, to quickly reach the melting temperature of the connecting components and form welding joints, achieving reliable connection of various components inside the lithium battery.