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Preparation method of spherical lithium iron phosphate anode materials

A technology for lithium iron phosphate and positive electrode materials, applied in chemical instruments and methods, phosphorus compounds, battery electrodes, etc., can solve the problems of large particle size, limited phase purity, and no memory effect of lithium iron phosphate, and achieve uniform product particles The effect of consistency, shortening the production cycle and improving product quality

Inactive Publication Date: 2013-04-17
IRICO
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[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

Method used

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  • Preparation method of spherical lithium iron phosphate anode materials
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Effect test

Embodiment 1

[0019] 1) Fe: Li: PO 4 =1:1:1 molar ratio added to deionized water, so that the prepared Fe 2+ , Li + 、PO 4 3- The concentration of the three ions is 1mol / L, stir and mix evenly.

[0020] 2) Add 6% sucrose by mass to the obtained mixture, stir and mix evenly.

[0021] 3) The obtained mixed solution is sprayed and pyrolyzed through a spray dryer, wherein the material inlet temperature is 180°C, and the outlet temperature is 80°C, to obtain lithium iron phosphate precursor powder uniformly mixed with materials.

[0022] 4) The obtained lithium iron phosphate precursor powder was put into a crucible, placed in a microwave sintering furnace, and heated at 2kW for 3h to obtain a spherical lithium iron phosphate positive electrode material with good crystallinity and uniform phase.

[0023] The appearance of the sample that the present invention obtains by above-mentioned embodiment 1 method is as follows figure 2 As shown, the particles are spherical.

Embodiment 2

[0025] 1) Fe: Li: PO 4 =1:1:1 molar ratio added to deionized water, so that the prepared Fe 2+ , Li + 、PO 4 3- The concentration of the three ions is 1mol / L, stir and mix evenly.

[0026] 2) Add 8% sucrose by mass to the obtained mixture, stir and mix evenly.

[0027] 3) The obtained mixed solution is sprayed and pyrolyzed through a spray dryer, wherein the material inlet temperature is 180°C, and the outlet temperature is 80°C, to obtain lithium iron phosphate precursor powder uniformly mixed with materials.

[0028] 4) The obtained lithium iron phosphate precursor powder was put into a crucible, placed in a microwave sintering furnace, and heated at 3kW for 2h to obtain a spherical lithium iron phosphate positive electrode material with good crystallinity and uniform phase.

Embodiment 3

[0030] 1) Fe: Li: PO 4 =1:1:1 molar ratio added to deionized water, so that the prepared Fe 2+ , Li + 、PO 4 3- The concentration of the three ions is 1mol / L, stir and mix evenly.

[0031] 2) Add 10% sucrose by mass to the obtained mixture, stir and mix evenly.

[0032] 3) The obtained mixed solution is sprayed and pyrolyzed through a spray dryer, wherein the material inlet temperature is 180°C, and the outlet temperature is 80°C, to obtain lithium iron phosphate precursor powder uniformly mixed with materials.

[0033] 4) The obtained lithium iron phosphate precursor powder was put into a crucible, placed in a microwave sintering furnace, and heated at 4kW for 2h to obtain a spherical lithium iron phosphate positive electrode material with good crystallinity and uniform phase.

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Abstract

The invention relates to a preparation technology of lithium ion battery anode materials, in particular to a preparation method of spherical lithium iron phosphate anode materials. The preparation method is characterized by comprising the following steps: obtaining a uniformly-mixed lithium iron phosphate precursor through a spraying, pyrolysis and settlement method and then carrying out microwave sintering to prepare a secondary particle with uniform grain size, i.e. the micron-sized lithium iron phosphate anode material. The preparation method has the advantages that the uniform lithium iron phosphate precursor is prepared by using the spraying, pyrolysis and settlement method, the mixing of molecular levels among the material is realized by adopting a method of mixing a reactant in a liquid phase, the moisture is quickly dried in the spraying and drying processes, iron is taken as a condensation nucleus, other element matters are attached onto the periphery of the condensation nucleus to be settled down in a powdery form, the uniformly mixing purpose is achieved, the material is directly heated through microwave sintering to be uniformly heated, the product particle is more uniform and consistent, the degree of crystallinity is good, and the product quality is improved.

Description

technical field [0001] The invention relates to the preparation technology of lithium ion battery cathode materials, in particular to a preparation method of spherical lithium iron phosphate cathode materials. 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 an...

Claims

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Application Information

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IPC IPC(8): C01B25/45H01M4/58
CPCY02E60/10
Inventor 王少卿李俊
Owner IRICO