Introduction to lithium cobaltate
Liquid phase synthesis process of lithium ion secondary battery cathode material (lithium cobaltate), which uses polyvinyl alcohol (PVA) or polyethylene glycol (PEG) aqueous solution as solvent, lithium salt and cobalt salt respectively dissolved in PVA or PEG aqueous solution The mixed solution is heated to concentrate to form a gel, and the innate gel is further decomposed by heating, and then calcined at a high temperature, and the calcined powder is ground and sieved to obtain lithium cobaltate powder.
Advantages and disadvantages of lithium cobalt oxide
advantage
LiCoO2 is a good cathode material for lithium-ion batteries. It has the advantages of high working voltage, stable discharge, high specific energy and good cycle performance. It is suitable for high-flow discharge and lithium ion insertion and extraction. It is obtained in lithium-ion batteries. Be the first to use. In addition, because it is easier to prepare, it is the only positive electrode material for lithium ion batteries that has been put into production. But now LiFePO4 cathode material is also commercialized and more a bit, called the future "life battery."
Disadvantage
The actual capacity of LiCoO2 is about 140 mA·h/g, which is only about 50% of the theoretical capacity (274 mA·h/g). In the repeated charge and discharge process, the active substance is activated by repeated insertion and extraction of lithium ions. The structure changes after multiple shrinkage and expansion, resulting in an increase in internal resistance of LiCoO2 and a decrease in capacity.
Method for synthesizing lithium cobaltate
1, freeze drying method
2, ultrasonic treatment
3. Improved combustion synthesis
4. Sonochemical synthesis
5. Precipitation and aging process
6, hydrothermal synthesis
7. Organometallic precursor method
Synthesis step of lithium cobaltate
Co(NO3):6H2O and LiOHH2O were ground in air at a rate of 200 r/min for 10 h, and then heated at 400 C to obtain a layered LiCoO having a structure. The ratio of Li to CO is 1:1, 1:1.22, 1:1.5.
Use of lithium cobaltate
Lithium cobaltate is widely used in high-power lithium-ion batteries.
What harm does lithium cobaltate have on people?
Lithium cobaltate is a lithium ion battery material. Insoluble in water and organic solvents, will not cause acute poisoning reactions to humans. Chronic exposure may have an effect on the respiratory tract and digestive tract. Long-term exposure may cause damage to the skin and mucous membranes. For example, the irritation of the respiratory tract may also have a certain effect on thyroid function. Respiratory and skin protection should be done.