Why do lithium-ion batteries explode or burn? Combustion or explosion usually occurs because heat accumulates and doesn't dissipate, either at an ignition point or at a specific point in space. In the case of batteries, there are generally no four reasons why this might happen.
1. Internal short circuit (mostly in large soft-pack cells): Structural or process defects lead to issues such as tab insertion, insufficient diaphragm filling, burrs, and diaphragm depreciation. Thick tab insertion and parallel structures within the cell are common, as is inadequate tab insulation. Adding a protection board to the product or using it during operation can easily lead to acute short circuits and internal combustion or explosion. (Internal short circuit: This person has extensive relevant experience, and waste batteries, especially those over 2k, are essentially design flaws: (acute internal short circuit), but this is rare nowadays unless external factors cause it.)
2. External Short Circuit: Explosions caused by external short circuits in batteries below 1AH are rare; they are usually caused by swelling or burnt-out tabs. My analysis focuses on combustion caused by external short circuits in power lithium batteries or high-capacity mobile phone batteries. This involves improper customer use, such as failing to consider tab insulation when installing metal casings, leading to abnormal battery smoke and combustion at the installation site; power lithium batteries are also often found to have insufficient structural fixing measures (inadequate consideration). During battery use, shaking can damage the outer insulating protective film or connector skin, ultimately leading to a short circuit and combustion.
3. Overcharge Explosion: This is the most dangerous and frightening issue, but it still happens occasionally. Based on my understanding, there are two reasons: a. The user did not use the matching charger as required, causing damage to the protection circuit. Users often charge the charger without regard to time. b. Improper battery configuration and protection board failure can also lead to explosions and chaos… The same applies to batteries.
4. The battery itself is made of substandard materials. If the materials are substandard, it may overheat under the calibrated voltage and current, causing an accident.
Based on the above analysis, if lithium-ion batteries are properly maintained and used, the above-mentioned situations can be prevented from occurring. The following methods can be summarized:
1. Frequent deep charge/discharge: Lithium-ion batteries have limited internal capacity. Many users of lithium-ion electric vehicles or digital products like to use the battery until it's completely depleted (to the last bit of protection) before recharging. Many consider this a way to activate the battery. However, in the use of lithium-ion batteries, the complete depletion of the battery is called deep charge/discharge.
In fact, deep charging and discharging is a significant mistake many people make when using lithium-ion batteries. Scientists have concluded through experiments that, under otherwise constant environmental conditions, the number of deep charge-discharge cycles is directly proportional to battery life; repeated charge-discharge cycles will lead to premature battery death. Furthermore, the ends of long-life lithium-ion batteries are prone to bulging and other issues, which can potentially cause explosions.
2. Overcharging and over-discharging protection board design is unreasonable and charging time is often a problem. We always like to let the device's battery stay fully charged for a while so that our device can withstand longer. However, many people do not know that long-term charging and discharging can seriously damage and destroy the performance of lithium-ion batteries. In severe cases, it can even cause explosions. Therefore, it is best to fully charge the battery. If it is always plugged into the charger, it will eventually lead to tragedy.
3. During charging and discharging, the charger's current and the appliance's general current load should be within the specified range. Excessive current load can easily cause internal short circuits in the battery, damaging lithium ions and creating circuit safety hazards. This also applies to the voltage of rechargeable chargers. Therefore, when using a charger, it is important to check whether the charger is qualified.
4. Operating Environment. Lithium-ion batteries are highly sensitive to temperature. Prolonged use below freezing point will significantly impact and damage battery life. However, if the battery is exposed to an overheated environment for an extended period, its lifespan will be drastically reduced. In severe cases, the battery may explode.
