A kind of preparation method of difluorophosphoric acid and lithium difluorophosphate

A technology of lithium difluorophosphate and difluorophosphoric acid, which is applied in the direction of phosphorus oxyacids, chemical instruments and methods, phosphorus compounds, etc., can solve the problems of low raw material utilization rate and high production cost, and achieve low cost, small side reactions, The effect of a wide range of sources

Active Publication Date: 2019-12-06
DO FLUORIDE CHEM CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to provide a preparation method of lithium difluorophosphate, thereby solving the problems of low utilization rate of raw materials and high production cost of existing preparation methods

Method used

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  • A kind of preparation method of difluorophosphoric acid and lithium difluorophosphate
  • A kind of preparation method of difluorophosphoric acid and lithium difluorophosphate

Examples

Experimental program
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Embodiment 1

[0022] The preparation method of the lithium difluorophosphate of the present embodiment adopts the following steps:

[0023] 1) Dissolve 252g of pyrophosphoryl chloride in 500g of dichloromethane, cool to -20°C, then dropwise add 18g of high-purity water, stir and react at -20°C for 8 hours, remove the dichloromethane by distillation under reduced pressure, and obtain 266.49g of dichlorophosphoric acid, The hydrolysis yield is 98.7%.

[0024] 2) Take 200 g of dichlorophosphoric acid, add 168.6 g of zinc fluoride, fully stir the reaction at 80°C for 24 hours, distill under reduced pressure, collect the distillate to obtain 148 g of difluorophosphoric acid, the yield is 98%;

[0025] Dissolve 148g of difluorophosphoric acid in 2 times (by volume) of ethylene glycol dimethyl ether, then cool to 0°C, add 55g of lithium carbonate, heat up to 30°C, fully react for 10h, filter off the excess lithium carbonate to obtain The clear and transparent solution was concentrated under reduc...

Embodiment 2

[0027] The preparation method of the lithium difluorophosphate of the present embodiment adopts the following steps:

[0028] 1) Adopt the method for embodiment 1 to prepare dichlorophosphoric acid.

[0029] 2) Take 280g of dichlorophosphoric acid, add 60g of anhydrous hydrogen fluoride (HF), fully stir the reaction at 10°C for 20h, blow out the excess anhydrous hydrogen fluoride with dry nitrogen, then distill under reduced pressure, collect the distillate to obtain difluoride Phosphoric acid 206g, yield is 98.2%;

[0030] Dissolve 200g of difluorophosphoric acid into twice (by volume) ethylene glycol dimethyl ether, then cool to 0°C, add 83.3g of lithium chloride (LiCl), raise the temperature to 40°C, fully react for 8 hours, and decompress Ethylene glycol dimethyl ether was concentrated and recovered, and the crystallized product was crude lithium difluorophosphate. After recrystallization using ethylene glycol dimethyl ether solvent, vacuum drying at 80°C for 12 hours gav...

Embodiment 3

[0032] The preparation method of the lithium difluorophosphate of the present embodiment adopts the following steps:

[0033] 1) Adopt the method for embodiment 1 to prepare dichlorophosphoric acid.

[0034] 2) Take 272g of dichlorophosphoric acid, add bismuth trifluoride (BiF 3 ) 358g, fully stirred and reacted at 60°C for 36h, distilled under reduced pressure, collected distillate to obtain 201.1g of difluorophosphoric acid, the yield was 98.6%;

[0035] Dissolve 200g of difluorophosphoric acid in twice (by volume) ethylene glycol dimethyl ether, then cool to 0°C, add 82.4g of lithium hydroxide (LiOH·H 2 O), heated up to 50°C, fully reacted for 4 hours, concentrated under reduced pressure to recover ethylene glycol dimethyl ether, and the crystallized product was crude lithium difluorophosphate. After the crude product lithium difluorophosphate was vacuum-dried at 80°C, the After recrystallization from alcohol dimethyl ether solvent, vacuum drying was carried out for 8 hou...

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Abstract

The invention relates to a preparing method of difluorophosphoric acid and lithium difluorophosphate. The preparing method of lithium difluorophosphate comprises the following steps of 1, carrying outa reaction between dichloro phosphate and a fluorinated reagent to prepare the difluorophosphoric acid, wherein the fluorinated reagent is AsF3, NH4F, NH4HF2 and / or MFx, for MFx, x is equal to 1 or 2or 3, and M is hydrogen, alkali metal, alkaline-earth metal or transition metal; 2, carrying out a reaction between difluorophosphoric acid and a lithium source material in a non-aqueous agent. According to the preparing method of lithium difluorophosphate, dichloro phosphate, the fluorinated reagent and the lithium source material serve as raw materials to carry out the reactions to prepare lithium difluorophosphate, and the raw materials are wide in source and low in cost; a fluoridation reaction and a substitution reaction of the lithium source material easily take place, the side reactionis small, a crude product of lithium difluorophosphate with few impurities is conveniently obtained under the condition of a high conversion rate, and thus good conditions are created for obtaining high-quality products of lithium difluorophosphate at low cost.

Description

technical field [0001] The invention belongs to the field of lithium ion battery additives, and in particular relates to a preparation method of difluorophosphoric acid and lithium difluorophosphate. Background technique [0002] In recent years, lithium-ion power batteries and energy storage batteries have become one of the research hotspots in the field of new energy. At present, the anode materials of lithium-ion power batteries are mainly lithium iron phosphate and nickel-cobalt-manganese ternary materials, and the electrolyte is mainly a liquid electrolyte system composed of lithium hexafluorophosphate and carbonate organic solvents. [0003] In the ternary positive electrode material system, adding an appropriate amount of lithium difluorophosphate can reduce the internal resistance of the battery, and form a protective film on the positive electrode of the battery, so that the cycle performance of the battery is significantly improved; at the same time, lithium iron p...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C01B25/455C01B25/16H01M10/0525H01M10/42
CPCC01B25/16C01B25/455C01P2006/80C01P2006/82H01M10/0525H01M10/4235Y02E60/10
Inventor 侯红军薛旭金郭琬杨明霞李云峰周苏薛峰峰耿梦湍于贺华刘海霞闫春生
Owner DO FLUORIDE CHEM CO LTD
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