Lithium battery process defects -Lithium - Ion Battery Equipment

What are the defects in lithium battery technology? -Lithium - Ion Battery Equipment

Lithium-ion battery process defects

1. Poor packaging

The proportion of bloated battery cells caused by poor packaging has been greatly reduced. We have already introduced the causes of poor packaging on the three sides of Topsealing, Sidesealing and Degassing. Poor packaging on any side will lead to battery cells. Most of them are Topsealing and Degassing. Topsealing is mainly due to poor sealing of the Tab position. Degassing is mainly due to delamination (including electrolysis). The influence of liquid and gel causes the separation of PP and Al). Poor packaging causes moisture in the air to enter the battery core, causing the electrolyte to decompose and produce gas.(Lithium - Ion Battery Equipment)

2. The surface of the Pocket is damaged

During the drawing process, the battery core is abnormally damaged or artificially damaged, causing the pocket to be damaged (such as pinholes), allowing moisture to enter the battery core.

3. Corner damage

Due to the special deformation of the aluminum at the folded corners, the shaking of the air bag will distort the corners and cause the Al to be damaged (the larger the battery cell, the larger the air bag, and the easier it is to break), losing its ability to block water. Wrinkle glue or hot melt glue can be added to the corners to alleviate the problem. In addition, it is forbidden to use air bags to move the battery cells during the various processes after top sealing. Pay more attention to the operation method to prevent the battery cells from swinging on the aging board.

4. The water content inside the battery core exceeds the standard.

Once the water content exceeds the standard, the electrolyte will fail and gas will appear after formation or degassing. The main reasons for excessive water content inside the battery include: excessive water content in the electrolyte, excessive water content in the bare battery core after baking, and excessive humidity in the drying room. If it is suspected that excessive water content is causing flatulence, a retrospective inspection of the process can be carried out.

5. Abnormal formation process

Wrong formation process can cause the battery cells to bloat.

6. SEI film is unstable

The battery cell's emission function was slightly bloated during the charge and discharge process of the capacity test.

7. Overcharge and overdischarge

Due to an abnormality in the process, machine or protective board, the battery cell will be overcharged or over-discharged, and the battery cell will be severely inflated.

8. Short circuit

Due to incorrect operation, a short circuit occurs between the two tabs of the charged battery cell. The battery cell will inflate and the voltage will drop rapidly, and the tab will be burned black.

9. Internal short circuit

A short circuit between the cathode and anode inside the battery core causes the battery core to rapidly discharge, heat, and become severely inflated. There are many reasons for internal short circuit: design problems; shrinkage, curling, and damage of the isolation film; Bi-cell misalignment; burrs piercing the isolation film; excessive clamp pressure; excessive extrusion of the edge ironing machine, etc. For example, due to insufficient width, the edge ironing machine excessively squeezed the battery core body, causing the cathode and anode to short-circuit and bloat.

10. Corrosion

The battery core corrodes, the aluminum layer is consumed by the reaction, loses its ability to block water, and flatulence occurs.

11. Abnormal vacuum pumping

System or machine reasons lead to abnormal vacuum degree and incomplete degassing; the heat radiation area of VacuumSealing is too large, causing the degassing bayonet to be unable to effectively pierce the pocket bag, resulting in unclean degassing.



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