KR102083080B1 - The method for preparing lithium difluorophosphate using difluorophosphate ester - Google Patents

Abstract

The present invention provides a method for producing industrially advantageously, at low cost, lithium difluorophosphate used as an additive applied to improving the performance of a nonaqueous electrolyte battery. The lithium difluorophosphate can be obtained by reacting a difluorophosphate ester, a lithium salt, and water obtained by fluorination of a dihalophosphate ester in a nonaqueous solvent. The lithium difluorophosphate thus obtained is a nonaqueous electrolyte battery. It can be used as an additive to improve the properties.

Description

The method for preparing lithium difluorophosphate using difluorophosphate ester}

The present invention relates to a process for producing lithium difluorophosphate, in particular, a process for producing lithium difluorophosphate using difluorophosphate ester, and more particularly, to a process for producing lithium difluorophosphate for non-aqueous electrolyte batteries. .

Recently, with the development of small storage products that can be employed in high-energy density applications such as smartphones, mobile power supplies, and tablet PCs, the output of the lithium battery industry is increasing. At the same time, the application of lithium-ion batteries is not limited to consumer electronics, and the two new trends in application of power and energy storage lead to a vast market for lithium batteries, mainly electric vehicles, hybrid vehicles and fuel cell vehicles. It is focused on high-capacity storage systems for power applications, including secondary power supplies and electrical energy storage. Policy storage and the expanding impact of the carrier operator network will also drive energy storage. Over the next few years, lithium ion batteries will become a global industry that can be expanded constantly.

As lithium ion secondary batteries expand their application fields, demands for improving battery characteristics are also increasing. Lithium difluorophosphate can significantly improve battery characteristics such as low temperature characteristics, circulation characteristics, and storage characteristics of lithium ion secondary batteries as an additive in an electrolyte. For example, Japanese Patent Laid-Open No. H11-067270 discloses a technique employing a non-aqueous electrolyte containing at least one additive selected from lithium monofluorophosphate Li ₂ PO ₃ F and lithium difluorophosphate LiPO ₂ F ₂ . It is. In this technique, the additive reacts with lithium to form a coating film at the interface between the positive electrode and the negative electrode, whereby the electrolyte is suppressed by contact between the positive electrode active material and the negative electrode active material. Therefore, self-discharge is suppressed and the storage characteristic after charge is improved. Japanese Patent Laid-Open No. 3439085 discloses a technique capable of improving the characteristics that can be circulated at high temperatures due to the effect of a film formed at the electrode interface by adding lithium difluorophosphate to the electrolyte.

According to the conventional literature or patent as a method for producing difluorophosphate, there are problems such as difficulty in obtaining raw materials and difficulty in separating, and thus cannot meet the requirements of large-scale industrial production. For example, Japanese Patent Laid-Open No. 2014-62036 discloses lithium difluorophosphate using a method of mixing LiPF ₆ and LiCl and passing water vapor. This method is inexpensive, but is not suitable for large-scale production because it is difficult to control the reaction, produces a lot of by-products, and is difficult to purify.

International Publication WO2012 / 004187A2 provides a method for producing lithium difluorophosphate. This method results in a gas-solid reaction of LiHPO ₄ and HF at 140 ° C. to produce a mixture of lithium difluorophosphate, lithium monofluorophosphate and lithium fluoride, which is difficult to separate. International Publication WO2012 / 004188A1 provides another method of producing lithium difluorophosphate. In this process, P ₂ O ₅ and LiF are subjected to a solid-solid reaction at 300 ° C. to produce a solid solution mixture of lithium difluorophosphate and lithium phosphate, which is pulverized to produce a small amount of di Lithium fluorophosphate can be separated.

In this context, the present invention provides a novel process for producing lithium difluorophosphate using difluorophosphoric acid esters. The present invention provides a method for producing an industrially advantageous low-cost lithium difluorophosphate used as an additive that can be applied to improve the performance of a non-aqueous electrolyte battery. The lithium difluorophosphate can be obtained by reacting difluorophosphate ester, lithium salt and water obtained by fluorination of dihalophosphate ester in a nonaqueous solvent, and the lithium difluorophosphate obtained is an additive which improves the performance of the nonaqueous electrolyte battery. Can be used as

The present invention provides a method for producing lithium difluorophosphate employing a difluorophosphate ester.

The manufacturing method of the present invention,

(1) reacting the dihalophosphate ester compound with a fluorinating agent under the action of a catalyst to obtain a difluorophosphate ester compound;

(2) a step in which the difluorophosphate ester compound, the lithium salt, and water obtained in step (1) are reacted in a nonaqueous solvent to obtain lithium difluorophosphate.

The said dihalophosphate ester compound is represented by following formula (1).

(1)

(One)

In said Formula (1), X and Y are independent, respectively, 1 type chosen from F, Cl, Br, and I (however, X and Y cannot select F simultaneously), R is a hydrocarbon group.

In one embodiment of the present invention, the non-aqueous solvent is cyclic carbonate, chain carbonate, cyclic ester, chain ester, n-hexane, cyclohexane, n-heptane, isoheptane, benzene, toluene, xylene, acetonitrile, methyl ether, Ethylene ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol dimethyl ether, diethylene glycol dimethyl ether, anisole, phenyl ether, and tetrahydrofuran are selected from the group.

In one embodiment of the present invention, the lithium salt is lithium chloride, lithium bromide, lithium fluoride, lithium iodide, lithium hydroxide, lithium carbonate, lithium bicarbonate, lithium phosphate, lithium dihydrogen phosphate, lithium lithium phosphate, lithium metaphosphate, It is 1 type, or plural types selected from lithium acetate and lithium sulfate.

In one embodiment of the present invention, the molar ratio of the difluorophosphoric acid ester, lithium salt and water is 1: 2: 2 to 1: 1: 0.01.

In one embodiment of the present invention, the fluorinating agent is one or a plurality selected from potassium fluoride, sodium fluoride, cesium fluoride, triethylamine trihydrofluoride, pyridine hydrochloride and ammonium fluoride.

In one embodiment of the present invention, the catalyst is one or a plurality selected from quaternary ammonium salts, polyethers and quaternary phosphonium salts.

In one embodiment of the present invention, the method for producing lithium difluorophosphate is carried out under the protection of nitrogen gas.

In one embodiment of the present invention, the reaction molar ratio of the dihalophosphate ester compound and the fluorinating agent is 1: (1 to 3).

In one embodiment of the present invention, the volume ratio of the mass of the dihalophosphate ester compound to the non-aqueous solvent is (0.1 to 0.5) g: (1 to 5) ml.

In one embodiment of the present invention, the molar ratio of the dihalophosphate ester compound and the catalyst is 1: (0.01 to 1).

The present invention has the following advantages over the prior art.

The dihalophosphate ester compound, the fluorinating agent, and the lithium salt, which are raw materials of lithium difluorophosphate prepared by the present invention, can be easily obtained, and because they are all solid or liquid, the reaction process can be easily operated and the overall reaction process conditions This mild, simple process is low and the demands on the device and the environment are low and the purity and quality of the produced lithium difluorophosphate is high.

The content of the present invention may be more readily understood by reference to the following detailed description and examples of preferred embodiments of the present invention. Unless specifically stated otherwise, all technical and technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. Where there is a contradiction, it is based on what is defined herein.

As used herein, the terms "manufactured by" and "contains or contains" have the same meaning. As used herein, the term "contains", "includes", "haves", "includes" or any transform thereof means to include non-exclusive. For example, a composition, step, method, article, or device is not necessarily limited to this element, and may include elements that are not explicitly pointed out or elements inherent in such a composition, step, method, article, or device.

The term "consist of" is intended to exclude all elements, steps or components not listed. Where applicable to a claim, the claim is a closed claim and does not include materials other than those listed (except ordinary impurities). The term "consisting of" does not limit the subject matter of the claims, and when employed as features other than the subject matter, only the elements relating to the feature are defined, and other elements are not excluded from the claim.

When an amount, concentration, other value, or parameter is represented by a range that limits the desired value of the range, the preferred range, or the upper limit, and the preferred value of the lower limit, any of the upper or preferred values of any range and the upper or preferred values of any range It is to be understood that all ranges formed by combining numerical values of are specifically disclosed. For example, if the range "1 to 5" is published, the ranges belonging to it are "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", " It should be understood that the range is 1 to 3 and 5 ". Unless specifically stated, a range of this specification includes the value of the end of the range, and all the integers and fractions within that range.

The singular forms “a,” “an” and “the” include plural referents unless the context clearly indicates otherwise. "Any" or "any one" indicates that the matter or event described below may or may not occur, and may include a situation in which an event occurs and a situation that does not occur.

Approximate representations of quantities in the specification and claims are not limited to the specific quantities of the invention, but also include modifications that do not result in changes in the basic functions that are accessible to and related to the quantities. Modification of numerical values such as "usually", "nearly", etc. means that the present invention is not limited to this exact numerical value. The approximate terminology used in any of the examples may correspond to the precision of the instrument measuring the numerical value. The limitations of the scope in the present specification and claims can be combined and / or interchangeable, and include all subranges falling therebetween, especially unless stated otherwise.

In addition, the terms "one kind" and "one or one" before the element or ingredient of the present invention do not limit the quantity (order shown) of the element or ingredient. Therefore, it should be understood that "a type" or "one or one" includes one or at least one meaning. Unless specifically stated in the context, elements or components in singular form may include plural forms.

"Polymer" means a polymer prepared by polymerizing the same or different types of monomers. The generic term "polymer" includes the technical terms "homo polymer", "copolymer", "terpolymer" and "copolymer".

"Copolymer" refers to a polymer prepared by polymerizing at least two different monomers. The generic term "copolymer" includes the terms "copolymer" (polymers generally made of two different monomers) and "terpolymers" (polymers generally made of three different monomers). It also includes polymers prepared by polymerizing four or more monomers. "Polyblend" refers to a polymer formed by mixing two or more polymers by physical or chemical methods.

The present invention provides a method for producing lithium difluorophosphate, which is easy to control in terms of technology, easy to obtain raw materials, low cost and high purity of the product.

The present invention provides a method for producing lithium difluorophosphate employing a difluorophosphate ester. This way,

(1) reacting the dihalophosphate ester compound with a fluorinating agent under the action of a catalyst to obtain a difluorophosphate ester compound;

(2) A step of reacting the difluorophosphoric ester compound, lithium salt and water obtained in step (1) in a nonaqueous solvent to obtain lithium difluorophosphate.

The said dihalophosphate ester compound is represented by following formula (1).

(1)

(One)

In said Formula (1), X and Y are independent, respectively, 1 type (s) X and Y cannot select F simultaneously from F, Cl, Br, and I, R is a hydrocarbon group.

The specific scheme is: RPO ₂ XY + MF → RPO ₂ F ₂ + MX + MY reaction (2).

In one embodiment of the present invention, R is a methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, linear or branched alkanes containing 1 to 10 carbon atoms, It is 1 type chosen from the group which consists of a phenyl group, benzyl group, and other substituted aromatic hydrocarbon group.

In one embodiment of the present invention, the MF is a fluorinating agent, which is at least 1 selected from the group consisting of potassium fluoride, sodium fluoride, cesium fluoride, triethylamine trihydrofluoride, pyridine hydrochloride, and ammonium fluoride. It's a species.

In one embodiment of the present invention, the catalyst is at least one selected from the group consisting of quaternary ammonium salts, polyethers, and quaternary phosphonium salts.

In one embodiment of the present invention, the reaction solvent of step (2) is n-hexane, cyclohexane, n-heptane, isoheptane, benzene, toluene, xylene, acetonitrile, methyl ether, diethyl ether, ethylene glycol dimethyl At least one member selected from the group consisting of ether, ethylene glycol diethyl ether, propylene glycol dimethyl ether, diethylene glycol dimethyl ether, anisole, phenyl ether and tetrahydrofuran.

In one embodiment of the present invention, the reaction molar ratio of the dihalophosphate ester compound and the fluorinating agent in the reaction (2) is 1: (1 to 3).

In one embodiment of the present invention, the volume ratio (w / v) of the mass of the dihalophosphate ester compound and the non-aqueous solvent in the reaction (2) is (0.1 to 0.5): (1 to 5).

In one embodiment of the present invention, the molar ratio of the dihalophosphate ester compound and the catalyst in the reaction (2) is 1: (0.01-1).

In one embodiment of the present invention, the reaction temperature at which the dihalophosphate ester compound RPO ₂ XY and the fluorinating agent MF form the difluorophosphate ester compound RPO ₂ F ₂ in the reaction (2) is 20 to 200 ° C. 1 to 24 hours.

Method of manufacturing a lithium phosphate-difluoro as a difluoromethyl employing the phosphoric acid ester compound by reacting a phosphoric acid ester compound, a lithium salt and a water-difluoro a non-aqueous solvent is to prepare a lithium phosphate directly difluoro reaction schemes, RPO ₂ F ₂ + LiZ + H ₂ O → LiPO ₂ F ₂ + HZ + ROH Reaction (3).

In one embodiment of the present invention, the LiZ is a lithium salt, and the lithium salt is lithium chloride, lithium bromide, lithium fluoride, lithium iodide, lithium hydroxide, lithium carbonate, lithium bicarbonate, lithium phosphate, lithium dihydrogen phosphate, hydrogen phosphate It is at least 1 sort (s) chosen from lithium, lithium metaphosphate, lithium acetate, and lithium sulfate.

In one embodiment of the present invention, the non-aqueous solvent is cyclic carbonate, linear carbonate, cyclic ester, chain ester, n-hexane, cyclohexane, n-heptane, isoheptane, benzene, toluene, xylene, acetonitrile, methyl ether, di It is at least 1 sort (s) chosen from ethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol dimethyl ether, diethylene glycol dimethyl ether, anisole, phenyl ether, and tetrahydrofuran.

In one embodiment of the present invention, the molar ratio of the reaction of the difluorophosphoric acid ester compound, lithium salt and water in the reaction (3) is from 1: 2: 2 to 1: 1: 0.01.

In one embodiment of the present invention, the volume ratio (w / v) of the mass of the difluorophosphoric acid ester compound and the non-aqueous solvent in the reaction (3) is (0.1 to 0.5): (1 to 5).

In one embodiment of the present invention, the reaction temperature for producing lithium difluorophosphate LiPO ₂ F ₂ by the difluorophosphate ester compound RPO ₂ F ₂ and lithium salt LiZ in the reaction (3) is from 0 to 80 ° C. The time is 1 to 24 hours.

By further purifying the lithium difluorophosphate produced in the reaction (2) and the reaction (3), a high-quality lithium difluorophosphate product can be obtained.

The present invention has the following advantages over the prior art.

According to the present invention, dihalophosphate ester compounds, fluorinating agents, and lithium salts, which are raw materials for producing lithium difluorophosphate, can be easily obtained, and since they are all solid or liquid, the reaction can be easily operated, and the overall reaction process conditions are It is gentle and simple in process, has low demands on equipment and environment, and has high purity and good quality of the produced lithium difluorophosphate.

Embodiment 1

This embodiment provides the manufacturing method of lithium difluorophosphate which employ | adopted difluorophosphate ester.

(1) reacting the dihalophosphate ester compound with a fluorinating agent under the action of a catalyst to obtain a difluorophosphate ester compound;

(2) A step of reacting the difluorophosphoric ester compound obtained in step (1) with lithium salt and water in a nonaqueous solvent to obtain lithium difluorophosphate.

The said dihalophosphate ester compound is represented by following formula (1).

(1)

(One)

In Formula (1), X and Y are each independently selected from the group consisting of F, Cl, Br, and I (wherein X and Y cannot simultaneously select F), and R is a hydrocarbon group. .

Embodiment 2

According to the method for producing lithium difluorophosphate using the difluorophosphate ester of Embodiment 1, the non-aqueous solvent is cyclic carbonate, chain carbonate, cyclic ester, chain ester, n-hexane, cyclohexane, n-heptane, iso From heptane, benzene, toluene, xylene, acetonitrile, methyl ether, diethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol dimethyl ether, diethylene glycol dimethyl ether, anisole, phenyl ether and tetrahydrofuran 1 type or multiple types chosen.

Embodiment 3

According to the method for producing lithium difluorophosphate employing the difluorophosphate ester of Embodiment 1, the lithium salt is lithium chloride, lithium bromide, lithium fluoride, lithium iodide, lithium hydroxide, lithium carbonate, lithium bicarbonate, phosphoric acid It is 1 type, or plural types chosen from lithium, lithium dihydrogen phosphate, lithium lithium phosphate, lithium metaphosphate, lithium acetate, and lithium sulfate.

Embodiment 4

According to the manufacturing method of lithium difluorophosphate which employ | adopted the difluorophosphate ester of Embodiment 1, the molar ratio of the said difluorophosphate ester, a lithium salt, and water is 1: 2: 2-1: 1: 0.01.

Embodiment 5

According to the method for producing lithium difluorophosphate employing the difluorophosphate ester of Embodiment 1, the fluorination agent is potassium fluoride, sodium fluoride, cesium fluoride, triethylamine trihydrofluoride, pyridine hydrochloride, fluoride 1 type or multiple types chosen from ammonium.

Embodiment 6

According to the method for producing lithium difluorophosphate employing the difluorophosphate ester of Embodiment 1, the catalyst is one kind or a plurality thereof selected from quaternary ammonium salts, polyethers and quaternary phosphonium salts. .

Embodiment 7

According to the method for producing lithium difluorophosphate employing the difluorophosphate ester of Embodiment 1, the method for producing lithium difluorophosphate is performed under the protection of nitrogen gas.

Embodiment 8

According to the manufacturing method of lithium difluorophosphate which employ | adopted the difluorophosphate ester of Embodiment 1, the reaction molar ratio of the said dihalophosphate ester compound and a fluorination agent is 1: (1-3).

Embodiment 9

According to the method for producing lithium difluorophosphate using the difluorophosphate ester of Embodiment 1, the volume ratio of the mass of the dihalophosphate ester compound and the non-aqueous solvent is (0.1 to 0.5) g: (1 to 5) ml to be.

Embodiment 10

According to the manufacturing method of lithium difluorophosphate which employ | adopted the difluorophosphate ester of Embodiment 1, the molar ratio of the said dihalophosphate ester compound and a catalyst is 1: (0.01-1).

The present invention will be described in detail with reference to the following Examples. On the other hand, the following examples are only for describing the present invention in more detail, and do not limit the protection scope of the present invention. Non-essential improvements and adjustments made by those skilled in the art based on the above-described contents of the present invention are also included in the protection scope of the present invention.

In addition, all raw materials are time-limited unless otherwise specified.

Example 1

300 ml of 29.9 g (0.1 mol) C ₆ H ₅ PO ₂ Br ₂ , 1.6 g (0.2 mol) potassium fluoride, 0.55 g (0.005 mol) tetramethylammonium chloride in a dry reaction kiln under nitrogen gas protection and at room temperature The mixture was added to dry toluene and stirred to slowly increase the temperature of the reaction kiln to 115 ° C. for 15 hours, and then the temperature of the reaction kiln was lowered to room temperature, filtered and concentrated to remove toluene to obtain an oily substance. Distillation under reduced pressure gave 14.3 g of C ₆ H ₅ PO ₂ F ₂ .

In a separate dry reaction kiln, 14.3 g of C ₆ H ₅ with nitrogen gas protection and 3.83 g (0.16 mol) of lithium hydroxide and 1.8 g (0.1 mol) of water at room temperature were added to 100 ml of dry ethylene glycol dimethyl ether with stirring. PO ₂ F ₂ was slowly added dropwise, the temperature of the reaction kiln was controlled to 50 ° C. or lower, the reaction mixture was kept at 45 ° C. for 5 hours after completion of the dropwise addition, and the solid obtained by evaporation of the solvent under reduced pressure was fresh. Re-dissolved with dry tetrahydrofuran and recrystallized at -25 ~ 0 ° C., to produce crystalline product in solution, then filtered to remove mother liquor, collected crystalline solid, vacuum dried at 60 ° C. for purity 6.4g was obtained with 99.3% of the crystal-like solid LiPO ₂ F _2.

Example 2

300 ml of 25.2 g (0.1 mol) C ₂ H ₅ PO ₂ Br ₂ and 12.6 g (0.3 mol) sodium fluoride, 0.32 g (0.001 mol) tetrabutylammonium bromide in a dry reaction kiln under nitrogen gas protection and at room temperature After adding to acetonitrile and stirring, the temperature of the reaction kiln was slowly raised to 50-60 ° C. and allowed to react for 20 hours. Then, the temperature of the reaction kiln was lowered to room temperature, filtered and distilled to give 10.3 g of C ₂ H ₅ PO ₂ F. ₂ was obtained.

In another dry reaction kiln, 10.3 g of C ₂ H ₅ PO under nitrogen gas protection and at room temperature were added 5.09 g (0.12 mol) lithium chloride and 0.9 g (0.05 mol) water to 100 ml of dry tetrahydrofuran with stirring. ₂ F ₂ was slowly added dropwise, the temperature of the reaction kiln was controlled to 60 ° C. or lower, the reaction was continued for 5 hours while the temperature was maintained at 55 ° C., and the solvent was evaporated under reduced pressure to fresh and dried tetrahydrofuran. After dissolving again, recrystallization at -25 ~ 0 ℃ to form a crystalline product in the solution, then filtered to remove the mother liquor, collect the crystalline solid, vacuum dried at 60 ℃ to crystallized 99.0% to obtain a shaped solid LiPO ₂ F ₂ 6.0g.

Example 3

47.5 g (0.2 mol) CH ₃ PO ₂ Br2, 18.52 g (0.5 mol) ammonium fluoride, 0.66 g (0.003 mol) tetraethylene glycol dimethyl ether in 300 ml dry aceto in a dry reaction kiln under nitrogen gas protection and at room temperature After adding to nitrile and stirring, the temperature of the reaction kiln was slowly raised to 50 to 60 ° C and allowed to react for 20 hours, and then the temperature of the reaction kiln was lowered to room temperature, and filtered and distilled to obtain 18.3 g of CH ₃ PO ₂ F ₂ .

In another dry reaction kiln, 18.3 g of CH ₃ PO ₂ F ₂ with 8.48 g (0.2 mol) of lithium chloride and 0.9 g (0.05 mol) of water added to 100 ml of dry acetonitrile under the protection of nitrogen gas and at room temperature Slowly added dropwise, the temperature of the reaction kiln was controlled to 60 ° C. or lower, and after completion of the dropwise addition, the mixture was kept at 55 ° C. for 5 hours to react, and the solvent was evaporated under reduced pressure to re-dissolve the solid obtained by fresh and dry acetonitrile. The mixture was recrystallized at 0 DEG C, produced a crystalline product in solution, filtered to remove the mother liquor, and the crystalline solid was collected and dried in vacuo at 60 DEG C to obtain 12.5 g of crystalline solid LiPO ₂ F ₂ having a purity of 99.1%.

Example 4

38.2 g (0.2 mol) CH ₃ (CH ₂ ) ₃ PO ₂ Cl ₂ , 18.52 g (0.5 mol) ammonium fluoride, 0.66 g (0.003 mol) tetraethylene glycol dimethyl ether Was added to 300 ml of dry acetonitrile and the temperature of the reaction kiln was slowly raised to 50-60 ° C. while stirring for 20 hours. The temperature of the reaction kiln was lowered to room temperature, followed by filtration and distillation to give 24.3 g of CH ₃ (CH _2). ) ₃ PO ₂ F ₂ was obtained.

In a separate dry reaction kiln, 24.3 g of CH ₃ (CH ₂ ) with the addition of 8.48 g (0.2 mol) lithium chloride and 0.9 g (0.05 mol) water to 100 ml of dry acetonitrile at room temperature under the protection of nitrogen gas. ₃ PO ₂ F ₂ was slowly added dropwise to control the temperature of the reaction kiln below 60 ° C. After completion of the dropwise addition, the reaction mixture was allowed to react for 5 hours while warming to 55 ° C. After dissolution, recrystallization at -25 ~ 0 ℃, to produce a crystalline product in the solution, then filtered to remove the mother liquor, collect the crystalline solid, and vacuum dried at 60 ℃ to obtain a 99.2% crystalline form 12.0 g of solid LiPO ₂ F ₂ was obtained.

The above embodiments are illustrative only and do not merely interpret the features disclosed herein. The scope of the claims is intended to protect all scopes which may be envisioned, and the examples herein are merely a description of the embodiments selected from all possible combinations of examples. Thus, the claims are not limited to the selection of characteristic examples that illustrate the invention. It should also be construed that scientific and technological advances may be replaced by possible equivalents or sub-categories which are not currently considered due to inaccurate causes of language expressions and that such changes are included in the scope of the claims where possible.

Claims (10)

(1) obtaining a difluorophosphoric ester compound by reacting the dihalophosphate ester compound with a fluorinating agent under the action of a catalyst;
Step (2) which obtains lithium difluorophosphate by making the difluorophosphate ester compound, lithium salt, and water obtained in step (1) react in a nonaqueous solvent,
The said dihalophosphate ester compound is represented by following formula (1),

(One)
In the formula (1), X and Y are each independent, and one selected from F, Cl, Br, and I (where X and Y cannot simultaneously select F), and R is a hydrocarbon group. A method for producing lithium difluorophosphate using difluorophosphate ester. The method of claim 1
The non-aqueous solvent is cyclic carbonate, linear carbonate, cyclic ester, chain ester, n-hexane, cyclohexane, n-heptane, isoheptane, benzene, toluene, xylene, acetonitrile, methyl ether, diethyl ether, ethylene glycol dimethyl ether , Difluorophosphoric acid using difluorophosphoric acid ester, characterized in that one or more selected from ethylene glycol diethyl ether, propylene glycol dimethyl ether, diethylene glycol dimethyl ether, anisole, phenyl ether and tetrahydrofuran. Method for producing lithium The method of claim 1
The lithium salt is selected from lithium chloride, lithium bromide, lithium fluoride, lithium iodide, lithium hydroxide, lithium carbonate, lithium bicarbonate, lithium phosphate, lithium dihydrogen phosphate, lithium lithium phosphate, lithium metaphosphate, lithium acetate and lithium sulfate A method for producing lithium difluorophosphate using difluorophosphate ester, characterized in that one or more species. The method of claim 1
A molar ratio of the difluorophosphate ester, the lithium salt and the water is 1: 2: 2 to 1: 1: 0.01. A method for producing lithium difluorophosphate using a difluorophosphate ester, characterized in that. The method of claim 1
The fluorinating agent is one or a plurality of difluorophosphate esters selected from potassium fluoride, sodium fluoride, cesium fluoride, triethylamine trihydrofluoride, pyridine hydrochloride, and ammonium fluoride. Method for producing lithium phosphate. The method of claim 1
The catalyst is a method for producing lithium difluorophosphate using a difluorophosphate ester, characterized in that one or more selected from quaternary ammonium salts, polyethers and quaternary phosphonium salts. The method of claim 1
A method for producing lithium difluorophosphate, wherein the method for producing lithium difluorophosphate is carried out under the protection of nitrogen gas. The method of claim 1
The reaction molar ratio of the said dihalophosphate ester compound and a fluorination agent is 1: (1-3) The manufacturing method of lithium difluorophosphate which employ | adopted the difluorophosphate ester. The method of claim 1
The volume ratio of the mass of the said dihalophosphate ester compound and a non-aqueous solvent is (0.1-0.5) g: (1-5) ml, The manufacturing method of the lithium difluorophosphate which employ | adopted the difluorophosphate ester. The method of claim 1
A molar ratio of the dihalophosphate ester compound and the catalyst is 1: (0.01 to 1), the method for producing lithium difluorophosphate having a difluorophosphate ester.