Safety problems caused by overcharge and discharge of lithium battery energy storage power supply:

Lithium ion battery (Li ion battery energy storage power supply) may lead to overcharge when it is misused or abused. When overcharged, there is a hidden danger of explosion due to a large amount of gas generated inside the battery. When lithium ion battery is overcharged, the battery voltage increases rapidly with the increase of polarization, which will cause irreversible changes in the structure of positive active material and decomposition of electrolyte, produce a large amount of gas and release a large amount of heat, resulting in a sharp increase in the temperature and internal pressure of the battery and hidden dangers such as explosion and combustion.

Objective: to test the overcharge and overdischarge of lithium battery energy storage power supply

The overcharge experiment is an important means to detect the safety performance of lithium-ion battery under the abuse of thermal shock, overcharge, overdischarge and short circuit. The purpose is to investigate the safety of the battery when the charging apparatus and current control circuit fail at the same time. If the battery passes the test, the chemical design (including electrolyte design, material selection, positive and negative capacity ratio, etc.) and structure design of the battery are reasonable.

How to prevent overcharge and overdischarge of lithium battery in energy storage power supply:

1. In order to prevent overcharge, special charging circuit is usually used or safety valve is installed to provide greater overcharge protection.

2. Positive temperature coefficient resistor (PTC) can also be used, which can make the battery overcharge and increase the internal resistance of the battery when the temperature rises to limit the overcharge current.

3. Special separators can also be used. When the temperature of the separator is too high due to battery abnormality, the pores of the separator will shrink and block to prevent lithium ion migration and overcharge.

4. If a special charger is used for the charging of lithium-ion battery, the charging voltage is generally limited to 4.2V, and the battery will not have any safety problems. However, if the special charger is not used, or the charger failure causes serious overcharge of the battery, it may cause fire and explosion of the battery. Battery charging control is very important, otherwise, there are serious safety problems.