What happens when a lithium battery expands under heat? How to repair

What happens when a lithium battery expands under heat? How do I fix it? During the manufacturing and use of lithium ion batteries, there is often swelling phenomenon. During the charging of lithium batteries, lithium ions are removed from the positive electrode and embedded into the negative electrode, resulting in an increase in the spacing between the negative electrode layers, leading to expansion. Generally, the thicker the battery core, the greater the expansion. The battery expands and is discarded and cannot be repaired. It is recommended to hand over the battery to a recycling company for recycling.

What happens when a lithium battery expands under heat?

Lithium battery expansion, commonly known as bulging, is due to a variety of reasons such as short circuits, excessive currents, and puncturing short circuits in the positive and negative electrode chemical materials inside the battery, resulting in sudden changes in the internal chemical substances. Gas is generated inside the battery due to high temperatures, and the battery is a highly sealed product. This generated gas cannot be discharged, so only the deformation caused by the expansion of the shell has created greater space for storing gas. The bottom and both sides of the battery are thicker than the front and back sides, and the area is smaller, so the drum is raised on both sides.

This kind of bulging lithium battery is basically unusable, with poor load carrying capacity. It can become fully charged when traveling, but it runs out of power as soon as a phone call is made, or it has been used for a short period of time. There is a phenomenon that power is available when the phone is turned off and restarted.

Lithium batteries contain electrolyte inside. After multiple repetitions, a portion of the electrolyte decomposes to produce gas, causing the battery to expand. Lithium batteries with severe expansion should not be used again. Currently, commercially available lithium batteries are basically made of lithium hexafluorophosphate electrolyte, which begins to decompose as soon as the temperature is high, reacting chemically with the solution, releasing gases such as carbon dioxide. The lithium salt used in the development of new electrolytes cannot be overcome temporarily. Try not to use it for a long time under high temperature.

What is the reason for the expansion of lithium batteries?

1. Overdischarge and overcharge of lithium batteries;

2. Micro short circuit, which means that the membrane is damaged, causing partial contact between the positive and negative electrodes inside the battery;

3. Continuous floating charging of lithium batteries at high temperatures leads to side reactions in the electrolyte, as well as high rate charging and discharging at high temperatures. This problem basically does not occur in civil use;

4. Low temperature charging is actually a micro short circuit caused by lithium precipitation penetrating the membrane;

5. The aluminum plastic film of the outer packaging is corroded;

6. "The vacuum is not clean, or when used in high altitude environments, mobile phone batteries are packaged in soft packaging, which has a significant impact.".

How to repair a lithium battery that swells when heated?

Lithium batteries are discarded when they expand. For safety reasons, it is recommended that the battery be handed over to a recycling company for recycling. Polymer lithium batteries can generate gas and therefore expand over time. In severe cases, the sealing area may leak liquid. If you find your battery bulging, for safety reasons, you should quickly stop using it and replace it with a new one.

When using a lithium battery, excessive charging and discharging times can cause bulging and bloating. At this time, the internal structure of the battery has been damaged, and the standby time will be much shorter. To avoid bulging up a lithium battery, it is important to develop good usage habits, such as using an original charger to charge your phone as much as possible, or using an accessory charger approved by the brand.

Long ago, lithium batteries needed to undergo deep discharge and deep charging three times to bring their power into play, but now new lithium batteries no longer have a memory effect and do not need to be discharged or overcharged. In addition, there is no need to charge for an extended period of time, and the lithium battery will automatically stop charging when fully charged. As long as the battery is charged in a timely manner before running out of power, do not wait for the battery to be fully powered off, as this can lead to excessive discharge of the lithium battery, resulting in a decrease in its power.

Three methods for repairing lithium batteries in mobile phones

1. Use a clean eraser or other cleaning tool to gently wipe the metal contacts on the lithium battery and the metal contacts on the phone, helping to maintain charging conditions and lasting power.

2. Wrap the lithium battery of an old mobile phone that uses an automatic shutdown device firmly with a plastic wrap, and wrap it as snugly as possible. There are three layers inside and outside to ensure that the battery is in a vacuum state. Then, wrap three layers of newspaper around the plastic wrap to completely seal the lithium battery. After 48 hours, remove the battery and remove the six layers of paper film wrapped around it. The surface of the lithium battery does not expand or deform due to freezing. After cooling for a period of time, then charge.

3. Thoroughly discharge the nearly discarded lithium battery, and then recharge and activate the battery. The specific method is to conduct deep discharge on the phone, which is to use up internal electrical energy to achieve deeper recharging, which requires some unconventional methods. Use a specific device to connect the phone to a low voltage small light bulb, and the internal power of the battery will be transferred to the small light bulb until all the light is discharged.

The above is the repair method for lithium batteries after thermal expansion. Lithium batteries are now widely used, and experts warn that the price of lithium batteries is not too high. Instead of laboriously repairing lithium batteries, it is better to purchase a new battery for convenience and cost-effectiveness. In addition, developing good usage habits is also a shortcut to extending the life of lithium batteries.