Research status of high pressure lithium cobalt oxide material shared by Car 18650 battery supplier.
Lithium cobalt oxide, which has two - dimensional laminar structure, is a widely used high voltage anode material. Structure, alpha-nafeo2, more suitable for lithium ion embedding and stripping. The theoretical energy density of lithium cobalt oxide is 274mAh/g, which has the advantages of simple production process and stable electrochemical property, so it has a high market share. In the practical application of lithium cobalt oxide material, only part of lithium ions can be reversibly embedded and extricated, and its actual energy density is about 167mAh/g (working voltage is 4.35v). Increasing its working voltage can significantly improve its energy density. For example, increasing its working voltage from 4.2v to 4.35v can increase its energy density by about 16%.
But under high voltage lithium ion from material embedded in and out many times makes the structure of the cobalt acid lithium from trigonal system to monoclinic system change, cobalt acid lithium materials at this time no longer have the ability to embed and out lithium ion, at the same time, the anode material of loose and fall off from the collection of fluid particles, cause the cylindrical power lithium-ion batteries internal resistance, electrochemical performance becomes poor.
At present, the modification of lithium cobalt oxide anode material mainly improves the stability of crystal structure and interface from doping and coating.
Current high voltage on the cobalt acid lithium materials been used in the high energy density batteries, such as high-end mobile phone battery manufacturers more and more high to the requirement of Cylindrical Rechargeable Electric vehicle li-ion Battery performance, which mainly reflected in the demand for higher energy density, such as carbon as required 4.35 V battery energy density of the cathode at around 660 wh/L, 4.4 V battery has reached about 740 wh/L, this requires the anode material has higher compaction density, higher empty volume, as well as the structure of materials under high pressure and the high voltage has a better stability. However, lithium cobalt oxide electrode material has shortcomings such as lack of cobalt resources and high price, and cobalt ion has certain toxicity, which limits its wide application in power batteries.