Comparison of the safety of various types of lithium-ion batteries

1. Lithium cobaltate battery: The most important feature of the preparation is that after fully charged, there is still a large amount of lithium left in the positive electrode. In other words, the negative electrode cannot contain more lithium attached to the positive electrode, but in the overcharged state, the excess lithium on the positive electrode will still swim to the negative electrode, and metal lithium ions will be formed on the negative electrode because it cannot be fully contained. Because this metal lithium ion is a dendritic crystal, it is called a dendrite. Once the dendrite is formed, it will provide opportunities to pierce the diaphragm. A puncture of the diaphragm will form an internal short circuit. Since the important component of the electrolyte is carbonate, the lightning and boiling point are low, so it will burn or even explode at higher temperatures. It is relatively easy to control the formation of lithium ion dendrites on small-capacity lithium-ion batteries. Therefore, lithium cobalt oxide batteries are currently limited to small-capacity batteries such as portable electronic devices, and cannot be used for power lithium batteries. 2. Polymer lithium-ion battery: The theoretical specific energy that is actually available has been greatly improved. It is related to lithium cobalt oxide batteries, which can better play high-capacity applications, but in terms of materials, polymer batteries are also used Lithium cobalt oxide and organic electrolyte have not fundamentally solved the safety problem. From the perspective of use, if the battery is short-circuited, there will be excessive current. The electrolyte of polymer lithium-ion batteries is colloidal, which is not easy to leak, which eliminates the possibility of leakage, but will cause more violent combustion. Therefore, spontaneous combustion is the biggest hidden danger of polymer lithium-ion batteries. 3. Lithium manganate battery: The material of lithium manganate battery has certain advantages. It can ensure that the lithium of the positive electrode can be completely embedded in the carbon pores of the negative electrode in the fully charged state, instead of the same as the lithium cobalt oxide. There is a certain amount of residue in the positive electrode, which fundamentally prevents the appearance of dendrites. This is a theoretical understanding. In fact, if the lithium manganate battery encounters strong external use or cut corners during the preparation process, it may cause the battery to instantly form lithium and move quickly during the charge and discharge cycle. Dendrites are formed when the negative electrode does not have time to fully receive lithium. Preventing this consequence should be guaranteed from the inspection of the battery when it leaves the factory. In short, the qualified lithium manganate battery generally does not cause safety accidents. Because the stable structure of lithium manganate ion makes its oxidation performance much lower than that of lithium cobaltate ion, even if an external short circuit (not an internal short circuit), it can basically prevent the precipitation of metallic lithium ions from causing combustion and explosion. 4. Lithium iron phosphate battery: This is an ideal power lithium battery that can be used for power tools and power cars. The theoretical capacity of lithium iron phosphate is 170mAh/g, and the actual capacity of the material is 160mAh/ g. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous post: What are the factors affecting the health of lithium-ion batteries?