Many people don't know the reason for the lithium battery bulge!

1、 Overcharging can easily cause swelling of lithium batteries

Overcharging can cause all 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 decrease in battery charge of lithium-ion batteries. During this process, there are more and more lithium ions in the negative electrode, and excessive accumulation causes lithium atoms to grow into tree stumps and crystallize, causing the bulge of the lithium-ion battery to occur.

2： Excessive discharge can easily cause swelling of lithium batteries

During the first charging and discharging process of liquid lithium-ion batteries, the electrode material reacts with the electrolyte at the solid-liquid interface, forming 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 freely embed and detach through this passivation layer, which has the characteristics of a solid electrolyte. Therefore, this passivation film is called SEI.

The SEI film is not static, and there will be slight changes during the charging and discharging process. Importantly, some organic compounds will undergo reversible changes. After excessive discharge of lithium-ion battery drums, the SEI film undergoes reversible ring breaking, which damages the SEI protecting the negative electrode material and causes the negative electrode material to collapse, resulting in the phenomenon of drums.

3： Unqualified lithium batteries are prone to bulging

The issue with the manufacturing level of lithium-ion battery drums may be due to uneven electrode coating and rough production process.

4： Lithium batteries are prone to bulging due to long-term use

Long term use can also lead to bulging, as air is conductive to a certain extent. Therefore, prolonged discharge is equivalent to direct contact between the positive and negative poles of the battery, causing a chronic short circuit.

Shenzhen Topband Battery Co., Ltd.，established in 2006, is a wholly-owned subsidiary of Shenzhen Topband Co., Ltd. (002139.SZ). We focus on lithium iron phosphate batteries,with independent research and development in cells and BMS. With the ability to integrate the entire industry chain, we are committed to providing customers with one-stop lithium battery solutions and services. Our quality products are widely used in energy storage and light power.