What are the common problems with lithium-ion batteries?

Lithium batteries are widely used. In our daily life, we use them in our mobile phones and computers, including travel tools, electric bicycles, solar street lamps and all kinds of power tools. However, in the process of using lithium batteries, we will inevitably encounter some difficult problems.

First, the voltage is inconsistent, some low

1. Self - discharge causes low voltage

The self-discharge of the cell is large, which makes the voltage drop faster than others.

2. Uneven charge leads to low voltage

When the battery is charged after detection, the cell is not evenly charged due to the inconsistent contact resistance or the charging current in the test cabinet. The voltage difference during short storage (12 hours) is small, but the voltage difference during long storage is large. There is no quality problem with this low voltage, which can be solved by charging, in the production of charge after storage over 24 hour's voltage measurement.

Ii. Lithium battery expansion

1. Lithium batteries expand when charged

When the lithium battery is charged, the lithium battery will naturally expand, but generally no more than 0.1mm, but overcharge will cause electrolyte decomposition, increase the internal pressure, lithium battery expansion.

2. Process expansion

Generally, processing abnormalities (such as short circuit, overheating, etc.) cause excessive internal heat electrolyte decomposition, lithium battery expansion.

3. Cyclic expansion

When the battery is in circulation, the thickness will increase with the number of cycles, but it will not increase after more than 50 cycles. Generally, the normal increase is 0.3~0.6mm, and the aluminum shell is relatively serious. This phenomenon is caused by the normal battery reaction. But if increase the shell thickness or reduce the internal material can be appropriate to reduce the expansion phenomenon.

Large internal resistance

1. Detection equipment difference caused

If the detection accuracy is not enough or the contact group cannot be eliminated, the display internal resistance deviation will be large; the ac bridge method should be used to test the internal resistance of the instrument detection.

2. Too long

Lithium battery storage too long, resulting in large capacity loss, internal passivity, internal resistance, can be activated through charging and discharging to solve.

3. Large internal resistance caused by abnormal heat

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