What causes lithium batteries to swell?

What causes lithium batteries to swell?

1. Improper use.

Batteries as consumables

After the battery is fully charged, continuing to charge it may cause an increase in internal pressure, leading to swelling.

Long term low voltage storage and self discharge lead to over discharge of the battery cells, resulting in deterioration of battery performance and causing bulging.

Long term full charge high voltage storage can lead to unstable battery state and performance degradation, resulting in bulging.

Using non original or non compliant chargers: Using non original or non compliant chargers may result in excessive current and damage to the battery. Non original chargers may not be able to accurately control the current like original chargers, resulting in battery damage and swelling.

Using fast charging and high current charging, long-term use of high current charging may have an impact on battery life. In severe cases of exceeding the standard, it may damage the internal structure of the battery and cause bulging.

Low temperature charging causes bulging.

2. Using batteries in high/low temperature environments, vibration environments, and humid environments can reduce their lifespan; Do not use batteries in high-frequency microwave or ultrasonic environments.

Charging in a high-temperature environment may accelerate the chemical reactions inside the battery, leading to an increase in internal pressure and causing swelling. Generally speaking, the optimal ambient temperature for charging is around 25 degrees Celsius.

3. The positive and negative connection wires of the battery should not overlap or make contact to reduce the risk of short circuit. Short circuited batteries may experience decreased performance and may swell and leak during use.

4. Sponge, skeleton, tape and other materials should be used inside battery packaging products to locate and prevent shock absorption, avoiding battery pack leakage/bulging caused by impact, vibration, falling, etc.

During the assembly process of battery components, if the installation position is incorrect or the assembly is not in place, it can cause scratches, crushing, and skin damage to the battery components. The battery will expand in size during charging and discharging, and the unreasonable space size can also cause the battery to bulge after a period of use.

5. The aging of batteries and multiple charging and discharging cycles under abnormal usage conditions may cause changes in the physical structure of the battery cells, leading to an increase in internal gas and pressure, and ultimately causing bulges.

6. Overcharging and over discharging.

The overcharge protection voltage of the protection board is higher than the allowable charging voltage, which belongs to safety protection. Improper charging design or charger reasons may cause the battery to be in a constant overcharge protection state, resulting in decreased battery performance and ultimately bulging. The same applies to over discharge protection, where the voltage point is lower than the cut-off voltage of the battery. When designing the product, it is necessary to consider designing the charging limit voltage and three-stage charging mode according to the usage situation, and turn off the discharge before the over discharge protection voltage.

Reminder: If any abnormal swelling, leakage, heating, odor, discoloration, deformation or other abnormalities are found in the battery during use, it should be stopped immediately!