How Safety Vents in Li-ion Batteries to Prevent Thermal Runaway?
Research shows that lithium batteries will lose more power as the number of charging cycles increases, especially with high-power fast charging technology, which will cause the internal temperature of the battery to rise, so safety must be put first. For new energy vehicles, thermal runaway is the most serious and most frequent safety accident.
How to Prevent Thermal Runaway?
The causes of thermal runaway are diverse. For thermal runaway of lithium-ion batteries, the current mainstream solutions in China are mainly external protection and internal improvement. Internal improvement refers to the improvement of the battery itself. External protection is more complicated, mainly referring to the upgrade and improvement of the system.
Battery Cell Composition
Take prismatic batteries as an example: battery packs are usually composed of multiple prismatic battery cells, which are used to store and release a large amount of electrical energy. Since lithium battery packs store a large amount of energy, once an abnormal situation occurs (such as overcharging, overdischarging, high temperature, etc.), it may cause gas generation and pressure increase in the battery pack, and even cause fire or explosion in severe cases.
To ensure the safety of the battery pack, each lithium battery is usually equipped with an battery safety vents. The prismatic lithium-ion battery safety vent is a safety device that can control the internal pressure of the battery and release overpressure or abnormal pressure in time to reduce the risk of explosion or fire.
The explosion value of the safety vents of new energy prismatic batteries is usually determined through engineering design, and the specific value will vary according to different battery types and design requirements. The selection of the explosion value needs to be determined according to the specific battery type and usage scenario, generally considering the maximum charging and discharging pressure of the battery, as well as factors such as temperature rise and current. The selection of the explosion value also needs to consider the manufacturing process and material characteristics of the explosion-proof valve.
Importance of Safety Vents in Li-ion Batteries
- Safety
The importance of safety pressure vents in li-ion battery systems cannot be underestimated. They are a key factor in ensuring the safety of electric vehicles and other battery applications. When dangerous events such as internal short circuits in batteries occur, the battery cell safety vents can respond quickly and prevent serious accidents.
- Design Standards
The explosion parameters of the prismatic cell safety vents are determined according to the design and use requirements of the battery. In addition, the opening force of the lithium battery safety valve also needs to be reasonably controlled. Too much or too little will affect the working effect of the valve. The explosion process of the battery safety valve mainly includes two stages: pressure accumulation and explosion release. In the pressure accumulation stage, the gas pressure inside the battery gradually increases. After reaching the threshold, the li-ion battery safety vent is rapidly exploded by the pressure. The valve is fully opened and enters the explosion release stage. The gas inside the battery is rapidly discharged through the valve, thereby maintaining the safe working state of the battery.
Heju’s Prismatic Cell Safety Vents-Meticulously Crafted “Micron-level Art”
The core process of “cold forging and stamping”
The core of bursting discs for prismatic batteries lies in the consistency of product burst values. The direct result of this process is that the discreteness of the burst pressure of each battery safety vent is compressed to the extreme. With many models, comprehensive specifications, single pressure range up to 0.02MPA, CPK>2.0, and more than 50 first-line punching machines. Batch stability has reached an almost demanding level, giving the “quick response” requirement a solid physical foundation. Contact us for your li-ion batteries safety vents projects now!