A kind of microwave synthesis method of nano-lithium iron phosphate

Abstract

The invention provides a microwave synthesis method of nano-lithium iron phosphate. The method mainly makes the primary particles nanometerized, the secondary particles micronized, and then performs rapid sintering and synthesis through microwaves to obtain nanometer lithium iron phosphate with uniform phase. On the one hand, it solves the disadvantages of the uneven particle size of the solid-phase method, and can achieve molecular-level mixing to obtain products with uniform particle size, achieve nanometerization of primary particles, micronization of secondary particles, and improve ion transmission rate, thereby improving its electrical conductivity. . On the other hand, through microwave sintering, the raw materials are evenly heated to obtain nano-lithium iron phosphate with uniform phase, and the sintering time is greatly reduced, saving a lot of resources and achieving the purpose of energy saving and emission reduction.

Description

technical field [0001] The invention relates to a preparation method of a positive electrode material of a lithium ion battery, in particular to a microwave synthesis method of nanometer lithium iron phosphate. Background technique [0002] In lithium-ion batteries, the cathode material is the most important component and the key to determining the performance of lithium-ion batteries. Lithium iron phosphate materials have the characteristics of good safety, excellent cycle performance, environmental friendliness, and wide sources of raw materials. Among them, lithium, iron, and phosphorus are all elements with abundant reserves on the earth, especially iron-based materials, which have a wide range of raw materials and low prices. It is recognized as the preferred cathode material for a new generation of lithium-ion batteries, and has become the key research and development direction of major developed countries in the world today. Moreover, due to the stability of itself a...

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Problems solved by technology

6. No memory effect

[0004] But at present, the preparation of most lithium iron phosphate cathode materials is mostly prepared by solid-state method sintering, and then it is ball milled and mixed with carbon for carbon coating to increase the conductivity of lithium iron phosphate. In fact, , the particle size of the lithium iron phosphate prepared by the solid-state method is relatively large, and the carbon cannot be directly mixed and evenly coated on the outside of the lithium iron phosphate particle. Secondly, even if the lithium iron phosphate with a smaller particle size is obtained by crushing, Carbon cannot be fully covered around lithium iron phosphate particles

Its conductivity is still limited, and on the one hand, the particle size obtained by the crushing method is uneven, and the efficiency is low, and secondly, it is easy to damage the structure of the material, which fundamentally determines its poor conductivity.

At the same time, whether the current lithium iron phosphate method is solid-phase or liquid-phase, most of them are sintered in a high-temperature sintering furnace for a long time. During the sintering process, the raw materials are heated unevenly, the purity of the phase is limited, and the power consumption is huge. higher cost

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