The detonation valve is the thin-walled body on the battery seal plate. When the pressure in the battery exceeds the specified value, the explosion-proof valve body ruptured to prevent the battery from bursting. The figure shows the appearance of two common explosion-proof valves. Explosion-proof valves are cleverly constructed, many of which are patented by battery manufacturers, but the basic principle is mainly laser welding of two specific shaped solid aluminum plates. When the internal pressure of the battery rises to a certain level, the aluminum plate is disconnected from the groove designed to prevent the battery from expanding further and causing an explosion. Therefore, this process is extremely strict to the laser welding process, which requires welding sealing, and the welding seam is the fracture pressure greater than the aluminum plate groove position.
Common shape of battery explosion - proof valve
This diagram shows the welding of an explosion-proof valve using a continuous laser and a pulse laser. Explosion-proof valves can be pulse laser and continuous laser welding. Pulse laser welding mainly realizes continuous seal welding by overlapping and covering solder joints and solder joints. The welding efficiency is relatively low and the sealing performance is poor (the pulse laser welding explosion-proof valve may crack under the circumstance of improper parameter adjustment). Continuous laser welding requires high assembly precision, but can ensure high speed, high quality welding, welding stability, welding efficiency and production. For example, the welding of 25mm×15mm flameproof valve diaphragm with 300W pulse laser requires more than 10 seconds, while the welding of 1000W single-mode fiber laser requires less than 2 seconds, which greatly improves the efficiency.