Supercritical continuous synthesis method of low-cost fluorinated lithium iron phosphate positive electrode material

Abstract

The invention discloses a supercritical continuous synthesis method of a low-cost fluorinated lithium iron phosphate positive electrode material. The supercritical continuous synthesis method comprises the following steps: carrying out impurity removal, filtration and reduction on pickling waste liquid in the iron smelting industry to obtain an iron source; preparing an iron source solution, a lithium source solution, a phosphorus source solution and a fluorine source solution in proportion in a stirring state, controlling the temperature of the system to be 150-220 DEG C and the pressure to be 3-5Mpa, and reacting to obtain slurry; carrying out filter pressing, washing and drying on the slurry to obtain powder; and carrying out heat treatment on the dried powder to obtain the fluorinatedlithium iron phosphate positive electrode material. According to the method, the low-cost iron-smelting industrial pickling waste liquid is selected as a raw material, and the nano fluorinated lithiumiron phosphate positive electrode material is synthesized in one step by utilizing the strong solubility and the ion migration capability of supercritical water. The obtained material is pure in phase, good in crystallinity, low in cost, simple in process, convenient to regulate and control and easy for large-scale continuous industrial production.

Description

technical field [0001] The invention relates to a preparation method of a lithium ion battery cathode material, in particular to a supercritical continuous synthesis method of a low-cost fluorinated lithium iron phosphate cathode material. Background technique [0002] Since the beginning of the 21st century, the explosive growth of the population has brought about a series of energy and environmental problems. With the growth of the population, the demand for fossil energy is increasing day by day. However, fossil energy is a non-renewable energy, and it is inevitable to face the exhaustion of fossil energy. At the same time, in the process of fossil energy development and utilization, it will inevitably bring a series of environmental pollution and ecological damage problems. my country is the world's largest coal consumer, and coal consumption accounts for more than 70% of the total commodity energy. Therefore, coal-burning industrial waste gas is one of the culprits of a...

AI Technical Summary

Problems solved by technology

However, the introduction of fluorine ions into the oxygen site of lithium iron phosphate requires a large amount of energy, which is not easy to achieve, the production cost is high, and the operation is complicated.

At the same time, in the process of industrial synthesis of lithium iron phosphate, iron sheets and iron powder are usually used as iron sources. High-purity iron sheets and iron powders are expensive, resulting in high production costs.

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