Why are electric vehicle batteries bulging?

Batteries are the core components of electric vehicles. I believe that the word bulging of electric vehicle batteries is familiar to all riders. In recent years, the phenomenon of battery bulging in electric vehicles is not uncommon, which makes many consumers very distressed. This is because once individual battery packs appear in a group of batteries, the entire group of batteries must be replaced. So what is the reason for the swelling of the electric vehicle battery? 　　 1. The quality of the battery itself is not enough. The quality problem of the battery is often the first reason that many car friends think of. I can’t help but YY must be the battery. Otherwise, why is it so? It breaks easily. Indeed, in the mixed electric vehicle battery market, many companies have limited battery manufacturing levels, uneven electrode coatings, rough production processes, and no air gaps for the batteries. Such batteries are extremely prone to bulging. 2. The safety valve pressure is too high. People in the industry know that electric vehicle batteries are equipped with a safety valve to ensure safety. When the pressure in the electric vehicle battery rises, the safety valve will automatically open to release the pressure to ensure the battery The internal and external air pressure is balanced. And if the safety valve cannot be opened normally when the pressure inside the battery rises, over time, the pressure inside the battery is too high and the pressure inside and outside is unbalanced, causing bulging.　　 3. Excessive charging and discharging　　 Many batteries are used in series in order to have more capacitance. It should be noted that frequent overcharging and overdischarging during battery use will cause poor gas recombination in the battery. A violent reaction similar to a short circuit will occur inside the battery, which will generate a lot of heat, which will cause the electrolyte to decompose and vaporize. It bulged up. Fourth, the charging current is too large. Normally, the electric vehicle batteries produced by regular manufacturers have a certain charging current value, and the charging current is greater than this reasonable current value during charging, which will easily lead to excessive precipitation on the electrode plate. In turn, the chemical reaction is insufficient. At this time, the temperature inside the battery will rise rapidly, and if the exhaust is not timely, the battery will bulge. Previous: Why should the old batteries of electric vehicles be recycled?