NiMH No.7 battery.Cause analysis and solutions for common lithium-ion problems?

　　With the rapid development of science and technology, the scope of use and functions of lithium batteries have long been self-evident. However, in our daily lives, lithium battery accident problems always emerge in endlessly and trouble us from time to time. In view of this, the editor has specially compiled lithium batteries. We hope to provide you with the analysis of causes and solutions to common ion problems.

　　1. Voltage is inconsistent and sometimes low.

　　1. Large self-discharge causes low voltage

　　The self-discharge of the battery core is large, causing the voltage to drop faster than others. The low voltage can be eliminated by storing and checking the voltage.

　　2. Uneven charging causes low voltage

　　When the battery is charged after testing, the cells are unevenly charged due to contact resistance or inconsistent charging current in the testing cabinet. The measured voltage difference is very small when stored for a short period of time (12 hours), but the voltage difference is larger when stored for a long period of time. There is no quality problem with this low voltage and can be solved by charging. After being charged during production and stored for more than 24 hours, the voltage is measured.

　　2. The internal resistance is too large

　　1. Caused by differences in testing equipment

　　If the detection accuracy is not enough or the contact electrical group cannot be eliminated, the displayed internal resistance will be too large. The AC bridge method principle should be used to test the internal resistance instrument.

　　2. Stored for too long

　　If the lithium battery is stored for too long, it will cause excessive capacity loss, internal passivation, and increased internal resistance. This can be solved through charge and discharge activation.

　　3. Abnormal heating causes large internal resistance

　　During the processing of the battery core (spot welding, ultrasonic wave, etc.), the battery is abnormally heated, causing the diaphragm to be thermally closed, and the internal resistance is seriously increased.

　　3. Lithium battery expansion

　　1. Lithium batteries expand when charging

　　When a lithium battery is being charged, the lithium battery will naturally expand, but generally not more than 0.1mm. However, overcharging will cause the electrolyte to decompose, increase the internal pressure, and cause the lithium battery to expand.

　　2. Expansion during processing

　　Generally, processing abnormalities (such as short circuit, overheating, etc.) cause excessive internal heating, causing the electrolyte to decompose and the lithium battery to expand.

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