Three dangerous consequences and explosion-proof measures for short circuit of lithium battery

Three dangerous consequences and explosion-proof measures for short circuit of lithium battery

The more serious consequences of the safety problems of lithium batteries are due to short circuits. If the electrolyte accidentally left in impurities, incorrect use the battery will be fever, cause the impurities from "static" to "dynamic", which may be draw a short circuit from the diaphragm that is used to prevent the positive and negative contact during the movement. A short circuit may cause three consequences, and it depends on the severity of the short circuit.

1, Leakage: when the temperature of the lithium battery rises slowly, the shell gradually melts, and the protective layer fails to protect, leading to the leakage of corrosive electrolyte.

2, Explosion: The temperature of the li ion battery rises rapidly, and since the shell will dissolve gradually when the temperature rises slowly. As a result, the inner space of the battery is not sufficient to accommodate the expansion gas under the heating condition, and the battery container exploded due to excessive pressure.

3, Self-ignition: the spark generated by short circuit will ignite electrolyte in the instant. This is because the electrolyte is made up of flammable liquid. The burning electrolyte will ignite the plastic fuselage and cause the battery to burn. If there is flammable substance around the battery, it will cause a fire.

Although the reports of self ignition and explosions of lithium batteries are common. This is because li ion battery manufacturers have taken these safety risks into consideration, and try to avoid this situation.

First of all, measures were taken from the internal structure of lithium battery. The quantity and size of the qualified li ion battery were controlled in a very small range, and the probability of breaking the membrane was very low.

Secondly, for portable products, li ion batteries, such as laptop batteries, are equipped with multi-level protection mechanism, even if the battery and computers are abnormal, the lithium battery can also turn to automatic protection.

Third, the use of warning measures. It includes: the original lithium battery, the original li ion battery charger, the suitable ambient temperature, non self refitting battery and so on.

However, the security measures of the above three aspects are not necessarily able to guarantee the full implementation of the 100%, for example, the protection mechanism of lithium batteries may also degrade in use after a long time, leads to overcharge and overdischarge, overcurrent, overheating sensitivity decreased, in these state, there may still be a potential safety hazard. In general, the theoretical accident probability of lithium batteries is only a few hundred thousand or more than one millionth, which is a mature product.