Why does the electric vehicle lithium battery explode?

   When the capacity of the negative electrode portion of the positive electrode portion of the lithium battery is insufficient, lithium atoms generated during charging cannot be inserted into the interlayer structure of the negative electrode graphite, and are deposited on the surface of the negative electrode to form crystals.

   The long-term formation of crystals in a lithium battery causes a short circuit, at which time the cell is suddenly discharged, generating a large amount of heat and burning the diaphragm. High temperatures decompose the electrolyte into a gas, and when the pressure is too high, the cell explodes.

   When charging, the water can react with lithium to form lithium oxide, which causes the capacity of the battery to be lost. It is easy to overcharge the battery to generate gas. The decomposition voltage of water is low, and it is easy to decompose and generate gas when charging. A series of generated gases will increase the internal pressure of the cell, and the cell will explode when the cell‘s outer casing cannot withstand it.

Third, internal short circuit

   The short circuit of the internal battery causes a large current discharge, generates a large amount of heat, burns the diaphragm, and causes a larger short circuit phenomenon, which will decompose the electrolyte into a gas, and the internal pressure is too large, and the battery core will explode.

   When the battery cell is overcharged, the lithium of the positive electrode is excessively released, which may change the structure of the positive electrode, and too much lithium may be released into the negative electrode, which may easily cause lithium deposition on the surface of the negative electrode, and when the voltage reaches 4.5 V or higher, The electrolyte decomposes to produce a large amount of gas. All of the above may cause an explosion.

   The external short circuit may be caused by the connection of the positive and negative poles. Due to the external short circuit, the battery discharge current is very large, which will cause the heat of the battery core. The high temperature will cause the diaphragm inside the battery core to shrink or completely deteriorate, causing an internal short circuit and thus exploding.