I. Lithium Batteries Under High Temperature: From "Quiet" to "Rageful"
Imagine that the lithium battery in your mobile phone becomes so hot that it can fry an egg after being exposed to the sun in summer - this is not an exaggeration. Inside the battery are electrolytes, positive and negative electrode materials, and other "chemical bombs". When the temperature exceeds 40℃, these materials become extremely active. The electrolyte may decompose and produce gas, and the positive and negative electrode materials may undergo oxidation-reduction reactions, like adding a catalyst to a pile of gunpowder, which could potentially trigger a chain reaction at any moment.
What‘s even more dangerous is that high temperature accelerates the movement speed of lithium ions between the electrodes, causing a sudden increase in internal pressure. If the battery shell is not sturdy enough or the safety valve design is unreasonable, it might burst like a balloon being punctured - but what comes out is not ribbons of colorful fabric, but high-temperature gas and flammable substances. When exposed to oxygen in the air, they could catch fire.
II. From "Flammable" to "Controllable": The Wisdom of Engineers
Don‘t worry! Modern lithium batteries are not "running wild" on their own. Engineers have put multiple layers of "protective suits" on them:
Diaphragm upgrade: A special material is added between the positive and negative electrodes. Under high temperature, it will automatically contract and seal the holes, preventing lithium ions from passing through. This is equivalent to pressing the "emergency stop button" for the battery.
Electrolyte improvement: Replace some flammable components with flame-retardant additives, similar to adding sand to gunpowder. Even if the temperature rises, it is less likely to catch fire.
Heat dissipation design: The battery packs of mobile phones and electric vehicles are equipped with heat sinks or liquid cooling systems, similar to installing an "air conditioner" for the batteries, to promptly remove the heat. These designs enable modern lithium batteries to maintain stability within the normal operating temperature range (0-45℃), but extreme high temperatures (above 60℃) may still lead to performance degradation or safety hazards.
III. Daily Use: Don‘t Let the Battery "Overheat"
Although lithium batteries have protective measures, we still cannot be reckless:
Avoid excessive exposure to the sun: During summer, do not leave your mobile phone or electric vehicle in the open parking lot for a long time. The metal casing absorbs heat, which can cause the battery temperature to soar.
Avoid "overcharging": Lithium batteries do not have a memory effect. Keeping the battery at 20%-80% charge for a long time is healthier. Remove the charger immediately after fully charging.
Stay away from heat sources: Don‘t place your phone near the stove when cooking, and don‘t cover it with a blanket when charging - these actions can cause the battery to "breathe poorly".
Regular inspection: If the battery of an electric vehicle bulges or leaks, it indicates that the internal part has been damaged. Don‘t hesitate to replace it immediately. Remember, batteries are sensitive to heat but not to cold (low temperature only temporarily reduces capacity, and it will recover when the temperature returns to normal). Proper usage can make it last longer with you!
