Method for uniform carbon coating on lithium iron phosphate surface

A lithium iron phosphate, uniform surface technology, applied in electrical components, battery electrodes, circuits, etc., can solve the problem of high volume specific energy, achieve the effects of low cost, low cost, and avoid segregation of components

Inactive Publication Date: 2016-06-08
CHINA ELECTRONIC TECH GRP CORP NO 18 RES INST
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0009] The purpose of the present invention is to solve the contradiction between the output characteristics of the current sampling circuit at the positive end of the power line and the complexity of the circuit, to provide a stable process, low cost, safety and environmental protection, high material consistency, excellent performance, organic carbon A method of uniform carbon coating on the surface of lithium iron phosphate particles with high source utilization rate, uniform carbon coating on the surface of lithium iron phosphate particles, and high volume specific energy of the material

Method used

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  • Method for uniform carbon coating on lithium iron phosphate surface
  • Method for uniform carbon coating on lithium iron phosphate surface
  • Method for uniform carbon coating on lithium iron phosphate surface

Examples

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Embodiment 1

[0032] See attached figure 1 and figure 2 .

[0033] A method for uniform carbon coating on the surface of lithium iron phosphate, comprising the following process steps:

[0034] 1. Preparation of emulsion: Weigh polyvinylpyrrolidone and deionized water at a mass ratio of 1:1 to prepare an aqueous solution, heat to 80°C, add polyacrylamide with 1% polyvinylpyrrolidone mass to it, and stir rapidly for 30 minutes to form a uniform composition lotion.

[0035] 2. Coating of organic carbon source on the surface of ferric acid particles: adding spherical iron phosphate twice the mass of the emulsion into the emulsion, stirring and mixing for 4 hours to obtain a rheological body with uniform composition, and drying it in a flash dryer to obtain Iron phosphate powder coated with polyvinylpyrrolidone.

[0036] 3. The preparation of lithium iron acid lithium / carbon composite cathode material: according to molar ratio Fe:Li=1:1.2 carry out solid-phase mixing with dry ferric phosph...

Embodiment 2

[0038] A method for uniform carbon coating on the surface of lithium iron phosphate, comprising the following process steps:

[0039] 1. Preparation of emulsion: weigh polyvinyl alcohol and deionized water in a mass ratio of 1:1 to prepare an aqueous solution, heat to 100°C, add triglycerol monostearate with 1% polyvinyl alcohol mass, Stir rapidly for 60 min to form a uniform emulsion.

[0040] 2. Coating of organic carbon source on the surface of ferric acid particles: add spherical iron phosphate twice the mass of the emulsion into the emulsion, stir and mix for 6 hours to obtain a rheological body with uniform composition, and dry it in a flash dryer to obtain Iron phosphate powder coated with organic carbon source.

[0041]3. Preparation of lithium iron oxide / carbon composite positive electrode material: according to the molar ratio Fe:Li=1:1.1, dry iron phosphate powder and lithium carbonate are mixed in solid phase, put into argon protective atmosphere sintering furnace...

Embodiment 3

[0043] A method for uniform carbon coating on the surface of lithium iron phosphate, comprising the following process steps:

[0044] 1. Preparation of emulsion: Weigh glycerin and deionized water at a mass ratio of 1.5:1 to prepare an aqueous solution, heat to 50°C, add TH-908 with 1% glycerin mass, and stir rapidly for 20 minutes to form an emulsion with uniform composition.

[0045] 2. Coating of organic carbon source on the surface of ferric acid particles: adding spherical ferric phosphate twice the mass of the emulsion into the emulsion, stirring and mixing for 2 hours to obtain a rheological body with uniform composition, and drying it in a flash dryer to obtain Iron phosphate powder coated with organic carbon source.

[0046] 3. Preparation of lithium iron phosphate / carbon composite positive electrode material: carry out solid-phase mixing of dried ferric phosphate powder and lithium hydroxide according to molar ratio Fe:Li=1:1, put into argon protective atmosphere sin...

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Abstract

Belonging to the technical field of lithium ion battery anode materials, the invention relates to a method for uniform carbon coating on a lithium iron phosphate surface. The method includes the steps of: (1) preparation of an emulsion: preparing an organic carbon source and water into an aqueous solution, conducting heating to 50-100DEG C, adding an additive, and performing stirring to form an emulsion; (2) coating of the lithium iron phosphate surface with the organic carbon source: adding spherical iron phosphate into the emulsion, performing mixing for 0.5-8h to obtain a rheological body, and conducting drying to obtain iron phosphate powder; and (3) preparation of a lithium iron phosphate/carbon composite cathode material: mixing iron phosphate powder with a lithium source according to a Fe-Li mole ratio of 1:1-1:1.2, placing the mixture into an argon protective atmosphere sintering furnace, conducting heat preservation at 250-400DEG C for 2-6h, then raising the temperature to 550-700DEG C and performing heat preservation for 6-16h, and carrying out furnace cooling and sieving so as to obtain the lithium iron phosphate/carbon composite cathode material. The method provided by the invention has the advantages of stable process, simplicity and easy control, low cost, safety and environmental protection, high utilization ratio of the organic carbon source, high volumetric specific energy of the material, and easy industrialization, etc.

Description

technical field [0001] The invention belongs to the technical field of lithium ion battery cathode materials, in particular to a method for uniform carbon coating on the surface of lithium iron phosphate. Background technique [0002] At present, lithium-ion batteries have the advantages of high voltage, high energy density, long cycle life, wide operating temperature range, and no pollution, making them have broad application prospects in portable electronic devices, electric vehicles, space technology, and defense industries. . [0003] Cathode materials are an important part of lithium-ion batteries, commonly used cathode materials are LiCoO 2 , LiNiO 2 , LiMn 2 o 4 、LiFePO 4 . LiCoO 2 It is a large-scale commercialized positive electrode material with good comprehensive performance, but it has the disadvantages of high price and high toxicity. LiMn with spinel structure 2 o 4 Low cost, good safety, but poor cycle performance. Lithium iron phosphate with an oli...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/36H01M4/58H01M4/62
CPCY02E60/10
Inventor 李文升樊勇利
Owner CHINA ELECTRONIC TECH GRP CORP NO 18 RES INST
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