If neither the charger nor the protection circuit stops the charging process, then more and more energy enters the cell. As a result, the voltage in the cell rises – this is known as over-charging.
Liu et al. found that the cell thermal stability decreased gradually as lithium-ion batteries aged with slight overcharge cycling. Compared with slight overcharge, deep overcharge can make lithium-ion batteries complete failure and cause thermal runaway, resulting severe safety hazards such as fire and explosion.
What causes a battery to overcharge?
Overcharging can happen for several reasons. Sometimes, it may be due to an incorrect charger that continues charging at the right time. Other times, it may occur because of a malfunction in the device's charging system. Regardless of the cause, overcharging can significantly affect the battery's performance and safety. Part 2.
Does a pouch lithium-ion battery overcharge?
In this paper, the overcharge performance of a commercial pouch lithium-ion battery with Li y (NiCoMn) 1/3 O 2 -Li y Mn 2 O 4 composite cathode and graphite anode is evaluated under various test conditions, considering the effects of charging current, restraining plate and heat dissipation.
How to improve overcharge performance of lithium-ion batteries?
Rupture of the pouch and separator melting are the two key factors for the initiation of TR during overcharge process. Therefore, proper pressure relief design and thermal stable separator should be developed to improve the overcharge performance of lithium-ion batteries.
What is the overcharge-induced tr process of lithium-ion batteries?
The overcharge-induced TR process of lithium-ion batteries is an electrochemical-thermal coupled process accompanied with ohmic heat generation, gas generation and a series of exothermic reactions .
Why does lithium overcharge a cell?
This situation is mainly caused by lithium plating. The plated lithium can react with the electrolyte at a lower temperature, and the thermal stability of the side reaction products is lower. However, when the overcharge exceeds V p, the cell temperature is higher.