How to process the cathode material of lithium iron phosphate battery

The carbothermic reduction method is also one of the high-temperature solid-phase methods. It is a relatively easy industrial synthesis method. Most of them use lithium dihydrogen phosphate (LiHPO4), ferric oxide (Fe2O3) or ferroferric oxide and sucrose as raw materials. After mixing, it is roasted under the protection of high temperature soft fish gas or nitrogen, and the carbon reduces the trivalent iron to the divalent iron, that is, the lithium iron phosphate is synthesized by the carbothermal reduction method. Advantages: The oxidation reaction that may be triggered during the mixing of raw materials is processed, making the synthesis process more reasonable, and improving the conductivity of the material. Disadvantages: The reaction time is relatively long, the temperature is difficult to control, and the control conditions required for product consistency are more stringent, and it is difficult to adapt to industrial processing. 2. Hydrothermal synthesis method Hydrothermal synthesis method belongs to the field of wet method. It uses soluble ferrous salt, lithium salt and phosphoric acid as raw materials to directly synthesize LiFePO4 under hydrothermal conditions. Because the solubility of oxygen in the hydrothermal system is very small , The synthesis of LiFePOA in the hydrothermal system provides an excellent inert environment. Advantages: The hydrothermal method can prepare ultra-fine particles in the liquid phase, and the raw materials can be mixed at the molecular level. It has the advantages of average phase, small powder particle size and easy operation, and has the advantages of easy mass production, good product batch stability, and low cost and easy availability of raw materials. At the same time, do not inert atmosphere during processing. Disadvantages: The structure of the product prepared by the water-cooking synthesis method often has iron dislocation, which generates metastable FePO, which affects the chemical and electrochemical properties of the product. At the same time, there are also shortcomings such as uneven particle size, impure phases, large equipment investment (high temperature and high pressure reactor design and manufacture are difficult, and the cost is also high) or the process is more complicated. 3. In addition, sol-gel synthesis method, liquid phase co-precipitation method, microwave synthesis method, etc. are also used in the preparation of LFP raw materials. These processes have their own advantages and disadvantages, but after the improved process, the first three are more widely used. A123 in the United States and Phostech in Canada use the solid phase method, Valence in the United States uses the carbothermic reduction method, and LG Chem. Use the continuous hydrothermal synthesis method. In the material preparation process, conductive carbon coating is a key technology in the LiFePO2 preparation process. By pre-coating a high-quality conductive carbon layer on the surface of the foil, A123 effectively reduces the internal resistance of the battery and improves the high-rate discharge capacity of the lithium iron phosphate battery. 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: How long is the life of lithium batteries for electric vehicles?