Why Do Lithium Iron Phosphate Batteries Bulge?

Why do lithium iron phosphate batteries bulge?

1. Overcharging causes the lithium battery to bulge.

Excessive charging of the battery will cause the lithium molecules in the positive electrode material of the battery to completely enter the positive electrode material of the battery, thereby causing the original rounded square of the positive stage to deform and collapse, which is the key reason for the reduction of the battery capacity of the lithium iron phosphate battery. With the increase of the total number of lithium-ion batteries on the negative stage, the excessive deposition of lithium molecules makes them grow into tree-shaped crystals, which in turn causes lithium batteries to swell.

2. Drums caused by power loss.

When the lithium liquid rechargeable battery is charged for the first time, the metal electrode and the lithium battery electrolyte react on the solid and high-efficiency liquid phase page, resulting in a passivation treatment layer covering the surface of the metal electrode.

The generated passivation treatment film can reasonably block the basis of the molecular structure in the electrolyte of the lithium battery, but Li+ can be arbitrarily placed and adsorbed by the resin according to the passivation treatment layer, which has the characteristics of solid electrolyte, so this passivation treatment film is called. It is SEI. SEI film is not static, there will be a small amount of transformation in the whole process of battery charging, mainly because some organic compounds will have reversible transformation.

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The excessive charge and discharge of the lithium iron phosphate battery pack causes the SEI plastic film to cause reversible damage to the SEI plastic film. After maintaining the SEI, the positive electrode material of the battery, it collapses, resulting in a bag-up condition.

3. It is a manufacturing level problem

The production level of lithium iron phosphate battery packs is in a state of packaging, the electrode layer of lithium battery packs is uneven, and the production process is relatively rough.

4. The lithium iron phosphate battery pack will also appear bulging if it is not used for a long time. Since the gas is conductive to a certain level, the charging and discharging time is too long, which is equivalent to the direct contact between the positive and negative electrodes of the battery, resulting in long-term short-circuit failure.