What is the possible cause of the power lithium battery combustion?

　　Author ：Iflowpower – Portable Power Station Supplier

The explosion is a more common hazard performance of the dynamic lithium-ion battery system, which is also more serious, not only cause property damage and environmental damage, or even cause personal injury or life. Possible causes of combustion or explosion caused by dynamic lithium-ion battery systems: Another powered sub-reaction of a powered lithium-ion battery (battery cell) leads to thermal out of control, ionizing electrolyte and other flammable substances; high voltage circuit of power lithium-ion battery system The middle local part is too large, and there is a large current flowing out of the temperature rise to the temperature of the fire point temperature, the flammable substance inside the dynamic lithium-ion battery system; the exterior of the dynamic lithium-ion battery system, resulting in the internal temperature of the power lithium-ion battery system Continuous rise, reaching fire point temperature, igniting internal flammable substances. Analysis of the use of electric vehicles, the first case has a high probability, the risk factor is also high, and the electrical discharge side reactance causes thermal out of control to be an important reason for the combustion or explosion of the dynamic lithium-ion battery system.

The inside of the lithium ion battery has: the decomposition of the ESI film, the temperature range is 90 ~ 120 ° C; the reaction of the negative electrode and the electrolyte, the temperature reaches 120 ° C; the electrolyte decomposes, the temperature is about 200 ° C; positive and electrolysis The reaction of the liquid is accompanied by the positive electrode to analyze oxygen, the temperature ranges from 180 to 500 ° C; the reaction of the negative electrode and the binder, about 240 degrees. The root cause of the electrical cell heat loss (combustion, explosion) is that the heat excited side reactive inside the battery cell leads to heat accumulation, the rate of the electrical cells is less than the heat accumulation rate, the temperature continues to rise, directly reaches the fire point temperature, causing combustion and explode. The heat inside the battery core follows the energy conservation: QP = QA + QA formula Qp is the heat of various negative reactions inside the cell, QE is the heat exchanged in the battery and the environment, that is, heat dissipation, QA is telecommunications self-absorption Thermal and thermal accumulation.

If the QE ≥ QP is a negative value or zero, the internal temperature of the battery will not rise, and there is no thermal out of control; if QE

, improve the temperature of the fire point, such as Add a flame retardant material to the electrolyte, a ceramic diaphragm, etc. The above, the summary of thermal out-of control mechanism and prevention measures have been practiced in the system's full battery design, manufacturing, but there is different chemical properties for different materials systems in the actual, and there are different systems, and different systems. Design will also cause system-level dangers and solutions.