Does battery abuse affect the safety of lithium-ion batteries?

Lithium-ion batteries, because of their characteristics of high energy density, high power density, and long service life, stand out in chemical energy storage devices. Now they have been widely used in the field of portable electronic products. Now, with the support of national policies, Demand for electric vehicles and large-scale energy storage has also grown explosively.

Even if lithium-ion batteries are flawless in the process of manufacturing integration, it is difficult to avoid abuse in the actual operating conditions of users. Charging and discharge system(overcharge and overdischarge), ambient temperature(hot box), other abuses(acupuncture, extrusion, internal short circuit), etc., together with the increase in environmental humidity(seawater immersion) of the new national standard are due to abuse problems. Causes of safety problems. Overcharging will cause the crystal collapse of the positive active material, and the lithium ion deembedding channel will be blocked, which will cause the internal resistance to increase sharply, resulting in a large amount of Joule heat. At the same time, it will also reduce the ability of the negative active material to insert lithium and produce lithium branching crystals resulting in short circuits. consequence. Overheating of ambient temperature will cause a series of chain chemical reactions within lithium ion batteries, including the melting of the diaphragm, the reaction of positive-negative active material with the electrolyte, positive/SEI membrane / solvent decomposition, and the inclusion of lithium negative electrode and binder. reaction and so on. Acupuncture / extrusion is caused locally by an internal short circuit, and as with an internal short circuit, a large amount of heat is accumulated in the short circuit area, resulting in a result of thermal runaway.

In short, the safety of lithium-ion power batteries is a long way to go. Only by combining theory with practice can we usher in the true glory in the field of high-energy / high-power applications.

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