In recent years, as the application of lithium batteries in the energy storage and power industries has become more mature and widespread, fires and explosions related to lithium-ion batteries have occurred frequently, and the safety of lithium-ion batteries is worrying. Today, we will focus on exploring ways to solve the risk of lithium-ion battery safety accidents, and one of the new technologies is worthy of attention.

　　1. Why do lithium-ion batteries burn or even explode?

　　First, briefly understand the structure of the lithium battery. Lithium-ion batteries use carbon material as the negative electrode and lithium-containing compounds as the positive electrode, with a diaphragm in the middle to avoid short-circuiting of the positive and negative electrodes.

　　One of the causes of fire and explosion is frequent overcharging. Overcharge causes too much lithium to be released, and metallic lithium is formed on the surface of the negative electrode. Over time, these lithium metal crystals will pass through the diaphragm paper, short-circuiting the positive and negative electrodes.

　　Another reason is that the current continues to be too large during the charging and discharging process. Once the lithium battery design standard is exceeded, lithium ions will produce metallic lithium on the surface of the material. This is the same as overcharging, which is dangerous.

　　Excessive moisture content inside the battery is also one of the reasons for the explosion. After the lithium battery is used for a long time, there will be more or less a certain amount of water inside. This water will turn into gas under certain conditions, and then react with the lithium metal to generate a lot of heat energy, which may cause an explosion.

　　In addition, the high temperature, damage, and extrusion of lithium batteries are also important causes of fire.

　　2. Reduce the risk of battery safety accidents and reduce accident damage

　　In the case that battery safety accidents cannot be completely eliminated, certain measures can be taken at the module and system level to minimize the occurrence of safety accidents and reduce accident damage. For example, the module design performs a good thermal balance to avoid local overheating. The high thermal conductivity graphene thermal film is used to conduct heat conduction on the cell to delay the temperature rise of the cell, which can reduce the occurrence of thermal runaway to a certain extent.

　　3. Use new technology to reduce the risk of lithium battery fire

　　Recently, Korean researchers used semiconductor technology to improve the safety of lithium-ion batteries. By forming a protective semiconductor passivation layer on the surface of the lithium electrode, they successfully inhibited the growth of dendritic crystals.

　　In order to prevent the formation of dendrites of metallic lithium, the research team exposed a conductive semiconductor material to plasma, resulting in the formation of a semiconductor passivation carbonaceous layer between the lithium electrode and the electrolyte. This medium allows lithium ions to pass through, and at the same time prevents electrons and ions from interacting on the surface and inside of the electrode, and ultimately prevents the formation of metallic lithium and the growth of dendrites.

　　The technology for developing highly safe lithium metal electrodes proposed in this research provides a blueprint for the development of next-generation batteries that do not pose a risk of fire.

　　Lithium-ion battery (LIB) has become the main energy storage solution in modern social life. Among them, lithium iron phosphate batteries are a perfect substitute for lead-acid batteries, and are the first choice for grid-connected peak shaving, off-grid energy storage, photovoltaic energy storage, UPS, data center and other industries.