Factors Contributing to Thermal Runaway
4. The Overcharging Menace
Overcharging a battery is like force-feeding it energy it can’t handle. It causes the battery’s internal voltage to rise beyond its safe limit, leading to the breakdown of the electrolyte and the formation of metallic lithium on the anode. This metallic lithium can then cause internal short circuits, which generate heat and trigger thermal runaway. Think of it as trying to cram too much into a suitcase — eventually, the zipper is going to burst.
Modern devices have built-in charging circuits that are supposed to prevent overcharging. However, these circuits can fail, especially in older or lower-quality devices. Also, using the wrong charger can bypass these safeguards and pump excessive voltage into the battery. It’s always a good idea to use the charger that came with your device or a reputable replacement that’s specifically designed for it.
Leaving your phone plugged in overnight might seem harmless, but it can contribute to long-term battery degradation and increase the risk of overcharging, even with built-in protection. It’s generally better to unplug your device once it reaches 100% charge.
Basically, treat your battery with the respect it deserves. Don’t force-feed it electricity, and it’s less likely to throw a tantrum in the form of thermal runaway.
5. Physical Damage
Batteries are tougher than they look, but they’re not indestructible. Dropping your phone, crushing a laptop, or even just subjecting a battery to excessive vibration can cause internal damage that leads to thermal runaway. Even seemingly minor damage can create microscopic short circuits that start the chain reaction.
Think of it like this: imagine dropping a glass of water. Even if it doesn’t shatter immediately, the glass may develop hairline cracks. Over time, these cracks will weaken the glass, making it more likely to break. The same principle applies to batteries — even small damage can have long-term consequences.
Puncturing a battery is a surefire way to trigger thermal runaway. This is especially true for lithium polymer batteries, which are notoriously sensitive to physical damage. If you ever accidentally puncture a battery, don’t try to fix it yourself — dispose of it properly and safely.
So, handle your devices with care, and avoid subjecting your batteries to unnecessary trauma. A little bit of caution can go a long way in preventing a fiery mishap.
6. External Temperature
Batteries are happiest in a Goldilocks zone of temperature: not too hot, not too cold, but just right. Extreme temperatures can significantly impact battery performance and increase the risk of thermal runaway. High temperatures accelerate the degradation of the electrolyte and can cause internal components to break down.
Leaving your phone in direct sunlight, storing batteries in a hot car, or using devices in excessively hot environments can all contribute to thermal runaway. The heat increases the internal resistance of the battery, generating even more heat and creating a vicious cycle.
Conversely, extremely cold temperatures can also be detrimental, although they’re less likely to cause immediate thermal runaway. Cold temperatures reduce battery capacity and can lead to internal stress. Rapidly charging a cold battery can also be problematic, as it can cause lithium plating on the anode, increasing the risk of short circuits.
Keep your batteries cool and comfortable, just like you’d want to be. Avoid exposing them to extreme temperatures, and they’ll be much less likely to lose their cool (literally).