A method for preparing battery-grade iron phosphate using chloride salt as a medium

A technology of iron phosphate and chloride salt, applied in chemical instruments and methods, inorganic chemistry, phosphorus compounds, etc., can solve the problems of poor performance of iron phosphate, low ion utilization rate, etc., to improve the effect of impurity removal, high purity, The effect of large specific surface area

Active Publication Date: 2022-01-25
SINOSTEEL NANJING NEW MATERIALS RES INST CO LTD +1
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] Aiming at the problems of low ion utilization rate and poor performance of iron phosphate in the preparation of iron phosphate in the prior art, the present invention provides a method for preparing battery-grade iron phosphate using chloride salt as a medium

Method used

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  • A method for preparing battery-grade iron phosphate using chloride salt as a medium
  • A method for preparing battery-grade iron phosphate using chloride salt as a medium
  • A method for preparing battery-grade iron phosphate using chloride salt as a medium

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Embodiment 1

[0043] like figure 1 and figure 2 Shown, a kind of method for preparing battery-grade iron phosphate with chloride salt as medium, comprises the following steps:

[0044] S1: Take 2 mol of ferrous sulfate crystals, a by-product of titanium dioxide, add 1 L of water to dissolve, heat the reaction in a water bath at 70°C, add sodium hydroxide solution and 0.04 mol of phosphoric acid solution, adjust the pH to 2.0, react for 0.5h and then filter Washing obtains ferrous sulfate purification liquid;

[0045] S2: Add 3.0 mol of hydrogen peroxide to the ferrous sulfate purification solution for oxidation, then add a mixed solution of 2.4 mol of phosphoric acid and 2.5 mol of sodium chloride, and set the volume to 1.8 L to obtain a pre-reaction solution;

[0046] S3: Heat the pre-reaction solution at 150°C, during which deionized water is fed at a constant speed to maintain the iron ion concentration at 3.5mol / L, and the reaction time is 5h. After the heating is completed, deionize...

Embodiment 2

[0049] A method for preparing battery-grade iron phosphate using chloride as a medium, comprising the following steps:

[0050] S1: Take 2 mol of ferrous sulfate crystals, a by-product of titanium dioxide, add 1.33 L of water to dissolve, heat the reaction in a water bath at 85°C, add sodium hydroxide solution and 0.05 mol of phosphoric acid solution, adjust the pH to 1.8, and react for 1.0 h Filter and wash to obtain ferrous sulfate purification solution;

[0051] S2: Add 2.5 mol of hydrogen peroxide to the ferrous sulfate purification solution for oxidation, then add a mixed solution of 2.0 mol of phosphoric acid and 2.1 mol of potassium chloride, and set the volume to 1.1 L to obtain a pre-reaction solution;

[0052] S3: Heat the pre-reaction solution at 100°C, during which deionized water is fed at a constant speed to maintain the iron ion concentration at 4.0mol / L, and the reaction time is 4h. After the heating is completed, deionized water is fed at a constant speed, and...

Embodiment 3

[0055] A method for preparing battery-grade iron phosphate using chloride as a medium, comprising the following steps:

[0056] S1: Take 2 mol of ferrous sulfate crystals, a by-product of titanium dioxide, add 1.20 L of water to dissolve, heat the reaction in a water bath at 60°C, add sodium hydroxide solution and 0.043 mol of phosphoric acid solution, adjust the pH to 1.9, and react for 1.0 h Filter and wash to obtain ferrous sulfate purification solution;

[0057] S2: Add 2.7 mol of hydrogen peroxide to the ferrous sulfate purification solution for oxidation, then add a mixed solution of 2.2 mol of phosphoric acid and 2.2 mol of lithium chloride, and set the volume to 1.5 L to obtain a pre-reaction solution;

[0058] S3: Heat the pre-reaction solution at 140°C, during which deionized water is fed at a constant speed to maintain the iron ion concentration at 2.5mol / L, and the reaction time is 6h. After the heating is completed, deionized water is fed at a constant speed, and ...

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Abstract

The invention discloses a method for preparing battery-grade iron phosphate by using chloride salt as a medium, and belongs to the field of lithium battery cathode preparation. Aiming at the problems of low ion utilization rate and poor performance of ferric phosphate in the preparation of existing ferric phosphate, the present invention provides a method for preparing battery-grade ferric phosphate using chloride salt as a medium, which includes dissolving ferrous sulfate, a by-product of titanium white After adding precipitant to remove Ti 2+ Impurities are obtained from ferrous sulfate purification solution; after the ferrous sulfate purification solution is oxidized, a mixed solution of phosphoric acid and chloride is added to obtain a pre-reaction solution; the pre-reaction solution is heated, and after heating, it is diluted to obtain a white ferric phosphate slurry; the white The iron phosphate slurry is washed, filtered, dried, and roasted to obtain battery-grade iron phosphate. The present invention replaces the alkaline substance in the conventional method by adding chloride salt, and uses the chloride as a medium to adjust the pH in the solution to generate battery-grade high-purity iron phosphate with high specific surface area. , easy to industrial mass production.

Description

technical field [0001] The invention belongs to the field of lithium battery cathode preparation, and more specifically relates to a method for preparing battery-grade iron phosphate by using chloride salt as a medium. Background technique [0002] In recent years, lithium-ion batteries for power have developed vigorously. Lithium iron phosphate has been widely used in recent years because of its low preparation cost and high safety performance. The iron source for preparing lithium iron phosphate is mostly iron phosphate, and iron phosphate is usually prepared by using cheap titanium white by-product ferrous sulfate. Due to the low purity of ordinary ferrous sulfate, it cannot meet the requirements for preparing iron phosphate, so it needs to be purified can be used. In addition, with the mature development of the iron phosphate preparation process, more and more manufacturers have prepared battery-grade iron phosphate in recent years, so the superiority of the iron phosph...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C01B25/37
CPCC01B25/375C01P2004/01C01P2006/80
Inventor 鲍维东裴晓东骆艳华田然李晓祥
Owner SINOSTEEL NANJING NEW MATERIALS RES INST CO LTD
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