Method for preparing lithium iron phosphate anode material

Abstract

The invention relates to a method for preparing a lithium battery material, and discloses a method for preparing a lithium iron phosphate anode material. The method comprises the following steps that(1) slurry preparing: ferric salt and microcosmic salt are added into aqueous alkali, and heating reaction is carried out to obtain ferro-phosphorus compound slurry; (2) wet ball-milling: dopant modifier, carbon source and lithium salt are added into the slurry, the wet ball-milling is carried out until the particle size is 50-150 nanometers; (3) spray granulation: spray granulation is carried outon the ball-milled slurry to obtain spherical precursor; (4) high temperature sintering: the spherical precursor is sintered under an inert atmosphere, and the lithium iron phosphate anode material is obtained after the temperature is cooled to a room temperature. According to the method for preparing the lithium iron phosphate anode material, the preparation technology is simple, the energy consumption is lower, the particle size of the lithium iron phosphate anode material is smaller, the distribution is even, the carton coating effect is good, the compacted density is high, the gram volumeis high, a lithium ion battery prepared with the material has better performance and high cost performance, and is the lithium iron phosphate anode material applied to practical production and application.

Description

technical field [0001] The invention relates to a preparation method of a lithium battery material, in particular to a preparation method of a lithium iron phosphate cathode material. Background technique [0002] With the gradual consumption of the world's petroleum resources, the research and development of lithium-ion batteries have attracted more and more attention. The performance of lithium-ion batteries mainly depends on their positive and negative electrode materials. Lithium iron phosphate is a positive electrode material for lithium-ion batteries. , its safety performance and cycle life are unmatched by other battery materials, which meets the needs of frequent charging and discharging of electric vehicles, and the large-capacity lithium-ion batteries with lithium iron phosphate as the positive electrode material are easier to use in series, which can provide more energy for electric vehicles. high motivation. In addition, lithium iron phosphate has the advantages...

AI Technical Summary

Problems solved by technology

However, lithium iron phosphate has low electronic conductivity and slow ion diffusion, so lithium iron phosphate materials must be coated with carbon and nanosized to improve the performance of the material

[0003] The Chinese patent with the application number 201710749469.9 discloses a nano-modified method of lithium iron phosphate and the nano-modified lithium iron phosphate and lithium-ion batteries prepared by directly mixing the raw materials of lithium iron phosphate and carbon sources to obtain nanoparticles diameter of lithium iron phosphate, using this method not only has high requirements for ball milling equipment, but also has very large loss of accessories and high energy consumption, low production efficiency and high production cost

At the same time, the particle size distribution of the material is poor, the compaction density is low, and the gram capacity is low, resulting in no cost-effective advantage of the material

[0004] The Chinese patent with application number 20101029722.6 discloses a preparation method of lithium iron phosphate material. Nanoscale lithium iron phosphate particles are obtained by co-precipitation method, and then the positive electrode material of lithium ion battery is obtained by spray drying and sintering. However, the nanometer lithium iron phosphate particles formed by this method High-grade lithium iron phosphate material has uneven distribution of components, poor particle size distribution, and needs to be washed, dehydrated and dried many times, which consumes a lot of energy

Images