Many people don't know the reason why lithium batteries bulge!

1. Overcharging can easily lead to lithium battery bulging
Overcharging can cause all the lithium atoms in the positive electrode material to run into the negative electrode material, causing the originally full grid of the positive electrode to deform and collapse, which is also an important reason for the bulging of lithium-ion batteries. In this process, the number of lithium ions in the negative electrode increases, and excessive accumulation causes lithium atoms to grow stump crystals, causing the lithium-ion battery to bulge.

2. Overdischarge can easily lead to lithium battery bulging 

During the first charge and discharge process of liquid lithium-ion batteries, the electrode material and the electrolyte react at the solid-liquid interface to form a passivation layer covering the surface of the electrode material. The formed passivation layer film can effectively prevent the passage of electrolyte molecules, but Li+ can be freely embedded and removed through the passivation layer, which has the characteristics of a solid electrolyte, so this passivation film is called SEI.

The SEI film is not static, and there will be a little change during the charge and discharge process. The important thing is that some organic matter will undergo reversible changes. Lithium-ion battery bulging After excessive discharge, the SEI film is reversibly destroyed. After the SEI protecting the negative electrode material is destroyed, the negative electrode material collapses, thus forming a bulging phenomenon. 

3: Unqualified lithium batteries are prone to bulging 

Lithium-ion battery bulging may be a problem of lithium-ion battery bulging manufacturing level, uneven electrode coating, and rough production process. 

4. Lithium batteries are prone to bulging if they are not used for a long time

Bulging will also occur if they are not used for a long time, because air is conductive to a certain extent. Therefore, if they are left for too long, it is equivalent to direct contact between the positive and negative electrodes of the battery, resulting in a chronic short circuit.

Therefore, not only should you not overcharge and discharge during use, but before purchasing, it is especially important to buy a brand new A-grade lithium-ion battery for home energy storage.

XIHO factory has strict testing standards for each batch of orders, and checking the appearance of the battery before shipment is only one step.

1. The internal resistance difference of each battery is 0.1 milliohms, the voltage difference is 10mv, and they are matched before shipment

2. The battery is sufficient

3. The battery is flat

These inspection videos will be provided to customers for inspection.
*If you want to get further professional assistance in cells choosing, welcome to contact us!