How to design the internal structure of safe lithium battery?

The fear of a lithium-ion battery exploding in a mobile phone has always been a lingering afterthought, and global brands like dell and apple have had similar moments of embarrassment. That begs the question: is a lithium battery explosion inevitable?

Is used in the mobile phone, notebook, etcLithium ion batteries, a lithium ion battery is lithium ion in the positive and negative electrode movement to realize the power supply and release device, it requires that the lithium ion to move back and forth movement in positive and negative electrode cannot attach other influencing factors, namely cleanly. In theory, this design is completely can be achieved, but in practice, because of lithium ion battery is highly sensitive products, any abnormal situation could lead to problems with battery.

All lithium battery explosion is caused by short circuit, cause a short-circuit phenomenon had, over-current, overheating, etc. To top it off they are through the internal structure and the formation of short circuit batteries, lithium-ion batteries so-called internal to external, lithium battery structure itself is a process manufacturing process, manufacturing process and process is difficult to avoid defects of 100%.

Across the electrodes of lithium ion stay should be clean, shuttle in the electrolyte, the diaphragm shall also be without impurities, but in the process of manufacturing, electrolyte and diaphragm is difficult to completely avoid dust stained with metal fragments, copper foil or aluminum foil, etc. When people use undeserved, overcharge, discharge, flow) or put the lithium battery in extreme environment (high temperature), lithium batteries will overheat, quiet state has been broken fragments at room temperature, which will be in a warmer electrolyte for thermal motion in the space. Next, if the debris is close to the diaphragm, pieces of hot will affect the diaphragm isolation effect, will also cause a short circuit.

Visible, short-circuit is caused by two reasons: one is the battery in the body have impurities, 2 it is impurity will exercise, the mediation is calorific, therefore, short circuit inevitably accompanied by fever, fever is not necessarily a short-circuit. The third step, a short circuit will burst sparks, and electrolyte is flammable liquid, spark in a closed space will cause the battery of combustion and explosion, it is easy to understand. Therefore, there is a polymer lithium battery replace the liquid electrolyte with gel electrolyte, can reduce the probability of short circuit. But cannot avoid completely.

Once the battery short-circuit, based on the degree of the cell structure and the temperature is different, generally speaking, the battery experience in three conditions, discharge, burning and explosion and combustion cause safety problem is most serious.

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