Lithium Ion Battery Fire and Explosion

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The generated oxygen is one of the contributions to combustion triangle, at the same time, the negative electrode also releases oxygen and contribute to the combustion triangle. Fig. 3 shows the thermal behavior of charged negative electrode at elevated temperature. The heat flow profile shows that there are four exothermic peaks, and the first exothermic process is small and the mechanism needs further research. The second exothermic is thought the solid electrolyte interface (SEI) decomposing process, which is formed by stable layer, e.g., Li2CO3, and sub-stable layer, e.g., (CH2OCO2Li)2. The decomposition reaction onset temperature is 74oC, it reached to peak at 84oC, and the reaction as Eq. 3 [2]:
(CH2OCO2Li)2 →Li2CO3 +C2H4 +CO2 +12O2
(3)
0.1g Li0.86C6 + 0.1g
1M LiPF6/EC+DEC (1:1 w/w) in argon
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0 -10
Fig. 3. The Li0.86C6 with electrolyte thermal behavior at elevated temperature. Heating rate: 0.2oC·min-1.
1- g
W m/
wolf ta
eH
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Temperature / oC
The same with Li0.5CoO2 decomposition, the generated O2 are the contributions for both the combustion triangle and the rising up pressure in the lithium ion battery.
Both the cathode and anode decomposition are the exothermic processes, and the generated heats act as the necessary energy of the consequent reactions, which form the reaction chain, and more reactions with more heat output. By integrating the heat flow curves, the total reactions release 920 J·g-1 and 1,870 J·g-1 heats without/with electrolyte in Fig. 2, respectively, and the Li0.86C6 with electrolyte is 470 J·g-1 in Fig. 3. If heat transfer from the cell materials to the surrounding is neglected, and all the energy effect on the battery, that is act as the ignition source, then the battery is undergoing the danger of fire and explosion.
Thermal Diagraph of Lithium Ion Battery
The fuel, oxygen and energy provide the probability of fire and explosion, as the lithium ion battery is a closed system, so the gas products cause the increasing of the inner
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