9 Reasons Why Lithium Batteries Bulge

By John, Updated on January 30, 2024

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The use of lithium batteries has been very popular, but they have no memory. Why do some lithium batteries still bulge? Most reasons for lithium battery bulges are due to the irreversible accumulation of dendrites on the plates. This article briefly analyzes the causes and hazards of lithium battery bulges, and puts forward suggested preventive measures to provide information for everyone.

li ion battery bulging

Part 1. 9 Reasons for lithium batteries bulging

1. Overcharging

Overcharging will cause all the lithium atoms in the positive electrode material of the lithium battery to flow into the negative electrode material. This will cause the original full grid of the positive electrode to deform and collapse. This is also one of the main reasons for the decline in power after the lithium battery bulges. During this process, more and more lithium ions are in the negative electrode. The excessive accumulation causes the lithium atoms to grow into stump crystals, causing the lithium battery to bulge.

2. Excessive discharge

The SEI film protects the negative electrode material of lithium batteries and prevents the material structure from collapsing easily. And it can increase the cycle life of electrode materials. The SEI film is not static and will undergo slight changes during the charge and discharge process, mainly due to reversible changes in some organic matter. After the lithium battery is over-discharged, the SEI film is reversibly damaged. The negative electrode material collapses after the SEI that protects the negative electrode material is damaged, resulting in a bulging phenomenon.

3. Lithium battery charger

The charger parameters are inconsistent with the charger parameters required for lithium batteries.

4. Battery vulcanization

The main causes of battery vulcanization include high current discharge, inability to charge in time, deep discharge, frequent discharge, too short charging time, factors caused by the charger itself, etc.

6. Safety valve

If it is an electric vehicle battery, the electric vehicle battery has a safety valve. When the pressure in the electric vehicle lithium battery pack rises, the safety valve automatically opens to relieve the pressure. This will ensure the normal use of the battery. The lithium battery will bulge when the battery pressure rises and the safety valve cannot be opened.

7. Long periods of inactivity

Lithium battery packs may also bulge if not used for a long time because air is conductive to a certain extent. Therefore, if the lithium battery pack is left open for too long, it is equivalent to direct contact between the positive and negative electrodes of the battery, resulting in a chronic short circuit.

8. Lithium battery production

If the lithium battery production environment is harsh, the production equipment is old, etc., the coating of the battery is uneven, and dust particles are mixed into the electrolyte. These may cause lithium batteries to bulge or even explode when used.

In addition, during the production process of lithium batteries, the injection of electrolytes, the production and winding of electrode sheets, etc., may cause bulges in lithium batteries. For example, excessive or insufficient injection of electrolytes may cause lithium ions to expand during charge and discharge, causing bulges.

9. Battery usage environment

Lithium batteries are prone to bulge when used in high-temperature and high-humidity environments because the high temperature environment will accelerate the chemical reaction inside the lithium battery and evaporate the electrolyte, blocking the migration of lithium ions between the negative electrode and the positive electrode, forming a bulge.

lithium batteries bulge

Part 2. Dangers of lithium battery bulging

1. Capacity loss

After the lithium battery bulges, its internal structure is damaged, resulting in capacity loss. Capacity loss shortens the life of lithium batteries.

2. Security

Lithium battery bulging may cause safety hazards such as battery short circuits and leakage, and in serious cases, may lead to fires, explosions, and other accidents. Therefore, lithium battery bulging should attract sufficient attention.

Part 3. How to prevent lithium battery bulge

1. Choose high-quality batteries

When purchasing lithium batteries, you should choose those produced by regular manufacturers with good reputations and quality assurance. This can reduce the risk of lithium battery bulging.

2. Reasonable use and maintenance

When using lithium batteries, follow the manufacturer’s instructions and precautions. Avoid using it at too high or too low temperatures, prevent overcharging or over-discharging for a long time, and replace damaged batteries in time.

3. Regular inspection and replacement

Regularly check the appearance and internal structure of the lithium battery, and replace the battery promptly when bulging is found to ensure safe use.

Part 4. Summary

Lithium battery bulging is an important issue that affects the safe use of lithium batteries. Understanding its causes and hazards and taking corresponding preventive measures are of great significance to ensuring the safe use of lithium batteries. At the same time, lithium battery manufacturers are constantly optimizing production processes, improving product quality, and reducing the risk of lithium battery bulges.

Part 5. FAQs

Will the lithium battery bulge explode?

Bulging lithium batteries risk explosion due to the potential build-up of pressure inside the battery.
Can the lithium battery still be used after it bulges?

Due to safety concerns, it is not recommended to continue using a bulging lithium battery. It should be properly disposed of or recycled.
What is the cause of lithium battery bulge?

The bulging of a lithium battery can be caused by factors such as overcharging, overheating, physical damage, or manufacturing defects.
What to do if the lithium battery bulges?

If a lithium battery bulges, it should be handled with caution. Stop using it, place it in a fireproof container or bag, and contact a professional for proper disposal or recycling.