Method for preparing ferrous oxalate hydrated salt crystal

A technology of ferrous oxalate and oxalate, applied in the direction of organic chemistry, can solve the problems of large particle size and poor reactivity, and achieve the effect of good reactivity

Inactive Publication Date: 2008-07-02
海宁市盐官工业投资有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0010] The object of the present invention is to overcome the defects in the above-mentioned prior art that the particle size is relatively large, needs to be reprocessed and has poor reactivity when used as a synthetic raw material for the positive electrode active material lithium ferrous phosphate of a lithium ion s

Method used

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  • Method for preparing ferrous oxalate hydrated salt crystal
  • Method for preparing ferrous oxalate hydrated salt crystal
  • Method for preparing ferrous oxalate hydrated salt crystal

Examples

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Example Embodiment

[0019] The method for preparing ferrous oxalate hydrate salt crystals provided by the present invention includes contacting and reacting an aqueous solution of oxalate with an aqueous solution of divalent iron salt, wherein the contact reaction between the oxalate solution and the solution of divalent iron salt is carried out in an organic solvent and It is carried out in the presence of a mixed solvent of water, and the organic solvent is completely miscible with water.

[0020] According to the preparation method provided by the present invention, the contact reaction of the oxalate aqueous solution and the divalent iron salt aqueous solution is to add the oxalate aqueous solution and the divalent iron salt aqueous solution to a mixed solvent of an organic solvent and water, respectively.

[0021] According to the preparation method provided by the present invention, the pH value at the end of the reaction between the oxalate aqueous solution and the divalent iron salt aqueous s...

Example Embodiment

[0036] Example 1

[0037] Add 1.0 liter of ethanol (C 2 H 5 OH) is miscible with 0.2 liters of water to make a mixed solvent (temperature 25°C). Dissolve 556 grams (2 moles) of ferrous sulfate heptahydrate (FeSO 4 ·7H 2 O), and add a small amount of sulfuric acid to adjust the pH of the solution to 1.8. In addition, dissolve 368 grams (2 moles) of potassium oxalate monohydrate (K 2 C 2 O 4 ·H 2 O), and add a small amount of potassium hydroxide (KOH) aqueous solution to adjust the pH of the solution to 8.6. At a dropping rate of 50 ml / min, 2000 ml of potassium oxalate solution was dropped onto the ethanol mixed solvent over 40 minutes, and 2000 ml of ferrous sulfate solution was dropped onto the mixed solvent at the same rate over 40 minutes. With the dropping of potassium oxalate solution and ferrous sulfate solution, ferrous oxalate precipitated (temperature 25°C, pH 2.8).

[0038] Next, filtration is performed to recover ferrous oxalate, and the recovered ferrous oxalate is wash...

Example Embodiment

[0041] Example 2

[0042] Put 335 ml of ethanol (C 2 H 5 OH) is miscible with 65 ml of water to make a mixed solvent (temperature 25°C). Dissolve 556 grams (2 moles) of ferrous sulfate heptahydrate (FeSO 4 ·7H 2 O), and adding a small amount of sulfuric acid to adjust the pH of the solution to 2.0. In addition, dissolve 368 grams (2 moles) of potassium oxalate monohydrate (K 2 C 2 O 4 ·H 2 O), and add a small amount of potassium hydroxide (KOH) aqueous solution to adjust the pH of the solution to 8.0. At a dropping rate of 100 ml / min, 2000 ml of potassium oxalate solution was dropped into the ethanol mixed solvent over 20 minutes, and 2500 ml of ferrous sulfate solution was dropped into the mixed solvent at the same rate over 25 minutes. With the dropping of potassium oxalate solution and ferrous sulfate solution, ferrous oxalate was precipitated (temperature 25°C, pH 2.5).

[0043] Next, filtration is performed to recover ferrous oxalate, and the recovered ferrous oxalate is wash...

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Abstract

The invention relates to a preparation method for a hydrous salt crystal of ferrous oxalate. The method comprises a contact reaction between water solution of oxalate and water solution of ferrous salt, which is carried out in the presence of mixed solvent of organic solvent and water; the organic solvent and water are totally soluble. The hydrous salt crystal of ferrous oxalate prepared by the method provided by the invention has small average grain size, as small as 1-5 micron, has good reactivity, and is suitable for being as compound raw material of lithium iron phosphate, an active substrate of anode of lithium-ion secondary batteries.

Description

Technical field [0001] The invention relates to a method for preparing ferrous oxalate hydrate salt crystals, in particular, a method for preparing ferrous oxalate hydrate salt crystals for synthesizing lithium iron phosphate. Background technique [0002] At present, the cathode material commonly used in lithium batteries is lithium cobalt oxide (LiCoO 2 ), lithium nickel cobalt oxide (LiNi x Co 1-x O 2 ), Lithium Nickel Cobalt Manganese Oxide (LiNi x Co y Mn 1-x-y O 2 ) And lithium manganate (LiMn 2 O 4 ). LiCoO 2 , LiNi x Co 1-x O 2 And LiNi x Co y Mn 1-x-y O 2 It is an oxide with a hexagonal layered salt structure. Lithium ions move in the interstices of octahedral layers composed of O-Co-O. It has high conductivity and reversibility of lithium ion deintercalation. LiMn 2 O 4 It is an oxide with a three-dimensional spinel structure. Lithium ions move in an octahedral three-dimensional channel composed of O-Mn-O. It also has high conductivity and reversibility of lithium ion d...

Claims

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Application Information

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IPC IPC(8): C07C55/06
Inventor 白琳曹文玉肖峰
Owner 海宁市盐官工业投资有限公司
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