With the rapid development of technology, the scope and role of lithium batteries have long been self-evident, but in our daily life, the problem of lithium battery accidents is always endless, which is always plaguing us. In view of this, Xiaobian specially sorted out lithium. I think the reasons for the common problems of ions and the solutions are expected to be convenient for everyone.
First, the voltage is inconsistent, the individual is low
1. High self-discharge causes low voltage
The self-discharge of the battery core makes the voltage drop faster than others, and the low voltage can be eliminated by detecting the voltage after storage.
2. Uneven current causes low voltage
When the battery is tested, the charge of the battery is uneven due to the contact resistance or the inconsistent current of the test cabinet. In the short-term storage (12 hours), the voltage difference is small, but the voltage difference is large when stored for a long time. This low voltage has no quality problem and can be solved by charging. Store the voltage for 24 hours after charging in production.
Second, the internal resistance is too large
1. Detecting device differences
If the detection accuracy is not enough or the contact electric power group cannot be eliminated, the internal resistance of the display will be too large. The internal resistance instrument test should be tested by the principle of AC bridge method.
2. Long storage time
Lithium batteries are stored too long, resulting in excessive capacity loss, internal passivation, and increased internal resistance, which can be solved by charge and discharge activation.
3. Abnormal heat caused by internal resistance
The battery is processed (spot welding, ultrasonic, etc.) to abnormally heat the battery, causing the diaphragm to thermally close and the internal resistance is seriously increased.
Third, lithium battery expansion
1. Lithium battery expands while charging
When the lithium battery is being charged, the lithium battery naturally expands, but generally does not exceed 0.1 mm, but overcharging causes the electrolyte to decompose, the internal pressure increases, and the lithium battery expands.
2. Swell during processing
Generally, processing abnormalities (such as short circuit, overheating, etc.) occur, causing internal heat to be excessively decomposed by the electrolyte, and the lithium battery is expanded.
3. Swell during circulation
When the battery is circulating, the thickness will increase with the number of cycles, but it will not increase after more than 50 weeks. Generally, the normal increase is 0.3~0.6mm, and the aluminum shell is more serious. This phenomenon is caused by normal battery reaction. However, if the thickness of the casing is increased or the internal material is reduced, the expansion phenomenon can be appropriately reduced.