Thermal runaway is a dangerous and self-sustaining reaction in lithium-ion batteries that occurs when heat generation exceeds the battery's ability to dissipate it.
This is why users sometimes report batteries “running out quite suddenly”. The cutoff voltage for a lithium ion battery is around 3V. Battery degradation occurs when lithium ion batteries are over-discharged, such as dissolution of the copper current collector at the anode.
What determines the thermal runaway process of lithium-ion batteries?
Also, it was experimentally proved that three main exothermic reactions determine the thermal runaway process of lithium-ion batteries. The first main exothermic reaction of the thermal runaway is the reaction releasing the electrochemical energy accumulated in the lithium-ion batteries during their charging.
How do lithium ion batteries work?
Lithium ion batteries commonly use graphite and cobalt oxide as additional electrode materials. Lithium ion batteries work by using the transfer of lithium ions and electrons from the anode to the cathode. At the anode, neutral lithium is oxidized and converted to Li+.
Electrolyte Breakdown: At high temperatures, the electrolyte in lithium-ion batteries can break down, leading to the generation of gases and further heat, exacerbating the situation.
Which exothermic reaction causes thermal runaway in lithium-ion batteries?
Firstly, the paper strictly experimentally proved that three main exothermic reactions are responsible for the occurrence of thermal runaway in lithium-ion batteries. The first main exothermic reaction of thermal runaway is the reaction of the release of electrochemical energy accumulated in batteries during charging (21).
What happens when a lithium ion reacts with an electrolyte?
As the temperature increases, further reactions occur as the intercalated lithium reacts with the electrolyte [177, 178], which results in the potential release of C 2 H 5, C 2 H 6, and C 3 H 6 [179, 180]. Several reactions may occur between 90 and 300 °C, including SEI decomposition, ISC, cathode material decomposition, and electrolyte reactions.