Mixed rare earth compound-doped and modified lithium iron phosphate cathode material and preparation method thereof

A cathode material, lithium iron phosphate technology, applied in battery electrodes, electrical components, circuits, etc., can solve the problems of environmental pollution, complex separation process of rare earth elements, high cost, and achieve good compatibility, excellent cycle performance and low cost. Effect

Inactive Publication Date: 2011-06-22
HOLD FORTUNE BEIJING SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0011] The purpose of the present invention is to provide a lithium iron phosphate positive electrode material doped and modified by mixed rare earth compounds and its preparation method, which

Method used

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  • Mixed rare earth compound-doped and modified lithium iron phosphate cathode material and preparation method thereof
  • Mixed rare earth compound-doped and modified lithium iron phosphate cathode material and preparation method thereof
  • Mixed rare earth compound-doped and modified lithium iron phosphate cathode material and preparation method thereof

Examples

Experimental program
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Effect test

Embodiment 1

[0034] Mix 0.5mol of lithium carbonate, 0.95mol of ferrous oxalate, mixed rare earth oxides containing 0.05mol of rare earth elements and 1mol of ammonium dihydrogen phosphate, add 16.59g of sucrose, add 200ml of absolute ethanol to mix and disperse, and use a horizontal Type grinding equipment for grinding for 1 hour, using a solvent recovery drying oven to dry at 120°C, and recycling the dispersant at the same time; after crushing the dried material, use a planetary ball mill for dry ball milling for 2 hours to obtain the precursor of lithium iron phosphate cathode material . The precursor was placed in a tube resistance furnace under Ar / H 2 Under the atmosphere, after pre-calcining at 300°C for 4 hours, cool to room temperature, grind and compact, then carry out secondary calcination under the protection of the inert atmosphere in the above-mentioned furnace body, the calcination temperature is 600°C, the calcination time is 2h, cool to room temperature, and use The planet...

Embodiment 2

[0037] Mix 1 mol of lithium hydroxide, 0.49 mol of ferric oxide, mixed rare earth oxides containing 0.02 mol of rare earth elements and 1 mol of ammonium dihydrogen phosphate, add 30.1 g of sucrose, add 300 ml of absolute ethanol to mix and disperse, and use Grind for 4 hours with a horizontal grinding device, dry at 180° C. with a centrifugal spray dryer, and dry ball mill for 2 hours with a planetary ball mill to obtain a lithium iron phosphate cathode material precursor. Place the precursor body in a pusher furnace at N 2 / H 2 Under a reducing atmosphere, pre-calcine at 400°C for 2 hours, cool to room temperature, grind and compact, then carry out secondary calcination under the protection of the inert atmosphere in the furnace body, the calcination temperature is 700°C, the calcination time is 5h, and cool to room temperature. Use a planetary ball mill to crush the calcined material to the required particle size to obtain LiFe 0.98 Re 0.02 PO 4 / C cathode material.

...

Embodiment 3

[0040] Mix 1mol of lithium dihydrogen phosphate, 0.85mol of ferrous acetate, and mixed rare earth oxides containing 0.15mol of rare earth elements, add 18.34g of sucrose, and add 250ml of acetone dispersant to mix and disperse, then use a planetary ball mill for wet grinding, grinding The time is 8 hours. After drying at 200° C. in a constant temperature vacuum drying oven, dry ball milling is carried out for 2 hours using a planetary ball mill to obtain a lithium iron phosphate cathode material precursor. Place the precursor in a pusher furnace under Ar / H 2 Under the atmosphere, after pre-calcining at 500°C for 6h, cool to room temperature, grind and compact, then carry out secondary calcination under the protection of the inert atmosphere in the above-mentioned furnace body, the calcination temperature is 800°C, the calcination time is 12h, cool to room temperature, use The planetary ball mill crushes the calcined material to the required particle size to obtain LiFe 0.85 R...

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Abstract

The invention discloses a mixed rare earth compound-doped and modified lithium iron phosphate cathode material and a preparation method thereof, and belongs to the technical field of preparation of electrochemical power materials. In the cathode material, Fe-site doping is performed on a LiFePO4 cathode material by at least one rare earth element in a mixed rare earth compound; and the LiFePO4 cathode material is doped and modified by utilizing the mixed rare earth compound with low price by a solid-phase synthesis method. The process comprises the following steps of: adding a lithium source, a carbon source, a phosphorus source and a doped mixed rare earth compound into a dispersant agent for mixing and dispersing; preparing a precursor of a lithium iron phosphate material after wet-grinding, drying and crushing; performing secondary calcining on the precursor in an inert atmosphere; cooling to the room temperature; and crushing by ball-milling to obtain the LiFePO4 cathode material. The material and the preparation method have the advantages that: the prepared LiFePO4 cathode material does not need to separate rare earth elements; and the prepared material has the performance of high capacity, high electric conductivity, stable cycle life, and capacity of performing high-rate discharge.

Description

technical field [0001] The invention belongs to the technical field of preparation of electrochemical power source materials, in particular to a lithium iron phosphate cathode material doped and modified by mixed rare earth compounds and a preparation method thereof. The lithium iron phosphate cathode material is doped with a mixed rare earth compound to effectively improve the electrochemical performance of the material. Background technique [0002] Lithium-ion batteries have become an ideal power source for modern digital electronic products due to their advantages such as high working voltage, high energy density, low self-discharge rate, stability and environmental protection. With the continuous expansion of its application fields, the demand for lithium-ion batteries is increasing. At the same time, due to the urgent need for power energy and large-scale energy storage batteries, lithium-ion batteries should be more efficient, cheap and environmentally friendly. Impr...

Claims

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Application Information

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IPC IPC(8): H01M4/58H01M4/1397
CPCY02E60/122Y02E60/12Y02E60/10
Inventor 张沛龙葛静罗桂平朱永国杨增枝张沛梁崔丽
Owner HOLD FORTUNE BEIJING SCI & TECH
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