Common Problems of Lithium-ion Battery

Lithium-ion batteries are becoming more widely used. Our daily mobile computers include travel tools, electric bicycle solar street lights, and various electric tools. But the process of using lithium-ion batteries will inevitably not encounter some of the more intractable problems.

Voltage inconsistent, individual low

1. Low voltage due to large self-discharge

The self-discharge of the core is large, making the voltage drop faster than others, and the voltage drop can be eliminated by storing the post-inspection voltage.

2. Uneven charge causes low voltage

When the battery is tested, the charge of the core is uneven due to the inconsistent current of the contact resistance or the test cabinet. The voltage measured in a short time(12 hours) is very small, but the voltage varies greatly during long-term storage. This low voltage has no quality problem and can be solved by charging. The over24 hour voltage measurement is stored after the power is charged in production.

II. Lithium battery expansion

1. Lithium battery expansion when charged

When the lithium battery is charged, the lithium battery naturally expands, but generally does not exceed 0.1 mm. However, over-charging will cause the electrolyte to decompose, the internal pressure increases, and the lithium battery expands.

2. Expansion during processing

Generally, abnormal processing(such as short circuit, overheating, etc.) causes the decomposition of the internal heated electrolyte and the expansion of lithium batteries.

3. Cyclic expansion

When the battery is circulating, the thickness will increase with the increase in the number of cycles, but it will not increase after more than 50 weeks. Generally, the normal increase will be 0.3 to 0.6 mm. The aluminum shell is more serious. This phenomenon is caused by the normal battery reaction. However, if the thickness of the shell is increased or the internal material is reduced, the expansion phenomenon can be appropriately reduced.

III. Large internal resistance

1. Differentiation in testing equipment

If the detection accuracy is not enough or the contact power group can not be eliminated, the internal resistance of the display will be large. The principle of AC bridge method should be used to test the internal resistance instrument.

2. Excessive storage time

Lithium batteries are stored too long, causing excessive capacity loss, internal passivation, and internal resistance to increase, which can be solved by filling and activating.

3. Internal resistance due to abnormal heat

The page contains the contents of the machine translation.