Liquid lithium hexafluorophosphate deacidification device and deacidification method thereof

Abstract

The invention discloses a liquid lithium hexafluorophosphate deacidification device and a deacidification method thereof. The liquid lithium hexafluorophosphate deacidification device comprises a raw material liquid storage tank D-101, a deacidification resin fixed bed D-102 and a product storage tank D-103 which are connected in sequence, the deacidification resin fixed bed D-102 is filled with deacidification resin, the effective group of the deacidification resin is tertiary amino Ph-CH2-NR1R2, Ph is a skeleton benzene ring of the resin, and R1 or R2 is a hydrogen atom, an alkyl group or a pyridine group-PY; in the deacidification resin fixed bed D-102, replacing the carbonic ester solvent in the deacidification resin fixed bed D-102 with the liquid lithium hexafluorophosphate raw material from bottom to top; the acidity of the liquid lithium hexafluorophosphate treated by the deacidification process provided by the invention can be controlled to be not more than 50ppm, so that the use performance of the liquid lithium hexafluorophosphate in an electrolyte is powerfully guaranteed; the deacidification device provided by the invention is simple in connection structure, can realize continuous deacidification process treatment, is high in deacidification efficiency, and is very suitable for large-scale industrial application.

Description

Technical Field

[0001] The invention belongs to the field of preparation of battery electrolyte additives, and particularly relates to a deacidification device and a deacidification method for liquid lithium hexafluorophosphate. Background Art

[0002] Liquid lithium hexafluorophosphate refers to a lithium hexafluorophosphate carbonate solution obtained by the synthesis reaction of lithium fluoride and phosphorus pentafluoride in an alkyl carbonate or / and cycloalkyl carbonate as an organic solvent. Although the sources of phosphorus pentafluoride are different, they are more or less inseparable from a fluorine source (usually hydrogen fluoride). Due to the strong electron-withdrawing property of fluorine atoms in hydrogen fluoride, the separation of hydrogen fluoride and phosphorus pentafluoride is difficult, so that the refined gaseous phosphorus pentafluoride will inevitably carry hydrogen fluoride components. In the process of synthesizing liquid lithium hexafluorophosphate, hydrogen fluoride is dissolved in an organic solvent, which will eventually make the acidity of the prepared liquid lithium hexafluorophosphate high. Specifically, its acidity (measured in terms of mass fraction of hydrogen fluoride) is generally in the range of 0.01%-0.08%; in addition, due to the interaction between hydrogen chloride and lithium hexafluorophosphate, the degassed liquid lithium hexafluorophosphate contains a trace amount of hydrogen chloride, generally tens of ppm, which will also increase the acidity of the liquid lithium hexafluorophosphate.

[0003] The free acid acidity will seriously affect the performance of liquid lithium hexafluorophosphate in the electrolyte. Before preparing the electrolyte, the acidity of the liquid lithium hexafluorophosphate must be reduced to a level that has no significant effect on the acidity of the electrolyte: generally, the acidity of the liquid lithium hexafluorophosphate needs to be controlled within a range of no more than 50ppm, or 0.005%. However, the current technology does not have a deacidification process that can be implemented in batches, resulting in poor quality of liquid lithium hexafluorophosphate prepared by traditional processes.

[0004] Therefore, the applicant hopes to seek a technical solution to achieve the deacidification of liquid lithium hexafluorophosphate. Summary of the invention

[0005] In view of this, the object of the present invention is to provide a deacidification device and a deacidification method for liquid lithium hexafluorophosphate. The acidity of the liquid lithium hexafluorophosphate after the deacidification process provided by the present application can be controlled to be no more than 50 ppm, which effectively guarantees the performance of the liquid lithium hexafluorophosphate in the electrolyte; and the deacidification device provided by the present application has a simple connection structure, can realize continuous deacidification process treatment, has high deacidification efficiency, and is very suitable for large-scale industrial applications.

[0006] The technical solution adopted by the present invention is as follows: A deacidification device for liquid lithium hexafluorophosphate comprises a raw material liquid storage tank, a deacidification resin fixed bed and a product storage tank connected in sequence; wherein: The raw material liquid storage tank is provided with a feeding pipeline for realizing continuous feeding of liquid lithium hexafluorophosphate raw material; The deacidification resin fixed bed is filled with deacidification resin, and the effective group of the deacidification resin is tert- Amine group Ph-CH2-N (R1R2), wherein Ph is a skeleton benzene ring of the resin, and R1 or R2 is a hydrogen atom, an alkyl group or a pyridine group -PY; in the deacidification resin fixed bed, the liquid lithium hexafluorophosphate raw material displaces the carbonate solvent in the deacidification resin fixed bed from bottom to top; The discharge pipeline connecting the deacidification resin fixed bed and the product storage tank is provided with a flow After deacidification, the liquid lithium hexafluorophosphate flows into the product storage tank through the connecting discharge pipeline.

[0007] Preferably, a liquid material outlet pipeline is provided between the bottom of the raw material liquid storage tank and the bottom of the deacidification resin fixed bed, and a delivery pump is provided on the liquid material outlet pipeline.

[0008] Preferably, the upper ends of the raw liquid storage tank, the deacidification resin fixed bed and the product storage tank are respectively provided with a material inlet, a nitrogen inlet and a vent; wherein each nitrogen inlet is respectively connected to a nitrogen pipeline, and each vent is respectively connected to a vent pipeline.

[0009] Preferably, a first thermometer is installed at the lower portion of the raw liquid storage tank, and a first liquid level gauge and a first pressure gauge are installed at the upper portion thereof.

[0010] Preferably, a jacket is welded on the outer periphery of the cylinder of the deacidification resin fixed bed, which is used to pass refrigerant to remove heat from the material in the deacidification resin fixed bed; wherein the lower part of the jacket is connected to the refrigerant feed pipeline, and the upper part thereof is connected to the refrigerant discharge pipeline.

[0011] Preferably, a regulating valve is installed on the refrigerant discharge pipeline to adjust the refrigerant flow and thus adjust the material temperature in the fixed bed; and a second thermometer is installed on the lower side of the deacidification resin fixed bed, and a second pressure gauge is installed on the upper side.

[0012] Preferably, a third thermometer is installed at the lower part of the product storage tank, and a third pressure gauge and a second liquid level gauge are installed at the upper part thereof.

[0013] Preferably, a deacidification process for liquid lithium hexafluorophosphate comprises deacidifying a liquid lithium hexafluorophosphate raw material using a deacidification device for liquid lithium hexafluorophosphate as described above; the liquid lithium hexafluorophosphate raw material is a lithium hexafluorophosphate carbonate solution obtained by a synthesis reaction between lithium fluoride and phosphorus pentafluoride, and the acidity of the liquid lithium hexafluorophosphate after deacidification does not exceed 50 ppm.

[0014] Preferably, the liquid hourly space velocity of the liquid lithium hexafluorophosphate passing through the deacidification resin fixed bed is in the range of 0.5-10h -1 , more preferably 1-8h -1 The liquid hourly space velocity refers to the ratio of the volume flow rate of the liquid lithium hexafluorophosphate to the preset fixed liquid volume of the deacidification resin fixed bed, and the unit is h -1 .

[0015] Preferably, the inner diameter range of the acid-deacidifying resin fixed bed is 80-120 mm, the filling height of the acid-deacidifying resin is 0.25-0.35 m, and the filling volume of the acid-deacidifying resin is 1.5-2.5 liters; and / or before continuously feeding the acid-deacidifying resin fixed bed; the acid-deacidifying resin in the acid-deacidifying resin fixed bed is soaked in a carbonate solvent for at least 20 hours, and then continuously replaced into a product storage tank with a carbonate solvent until the product storage tank is sampled and tested for moisture less than 10 ppm, and the acid-deacidifying resin fixed bed is deemed qualified and can be used for deacidification.

[0016] It should be noted that the carbonate solvent involved in the entire application can be any well-known carbonate solvent, generally including alkyl carbonate solvents and / or cycloalkyl carbonate solvents. The most common solvents include dimethyl carbonate (DMC), diethyl carbonate (DEC), propylene carbonate (PC), ethylene carbonate (EC), and ethyl methyl carbonate (EMC). The specific solvents can be selected according to actual needs, and the application does not impose any special restrictions on them. It should also be noted that the refrigerant introduced into the jacket involved in the entire application can be a well-known refrigerant. For example, 2-5°C water can be selected as the input of the refrigerant feed pipeline to extract heat from the material in the deacidification resin fixed bed.

[0017] The present application proposes a deacidification device for liquid lithium hexafluorophosphate which is mainly composed of a raw material liquid storage tank, a deacidification resin fixed bed and a product storage tank. The liquid lithium hexafluorophosphate raw material is deacidified by the deacidification resin of the deacidification resin fixed bed. In specific implementation, the liquid lithium hexafluorophosphate raw material replaces the carbonate solvent in the deacidification resin fixed bed from bottom to top in the deacidification resin fixed bed, thereby achieving effective deacidification. The acidity of the liquid lithium hexafluorophosphate after the deacidification process provided by the present application can be controlled to be no more than 50ppm, which effectively guarantees the use performance of the liquid lithium hexafluorophosphate in the electrolyte. Moreover, the deacidification device provided by the present application has a simple connection structure, can realize continuous deacidification process treatment, has high deacidification efficiency, and is very suitable for large-scale industrial application. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structural connection of a deacidification device for liquid lithium hexafluorophosphate according to a specific embodiment of the present invention. DETAILED DESCRIPTION

[0019] See also Figure 1 As shown, this embodiment provides a deacidification device for liquid lithium hexafluorophosphate, comprising a raw liquid storage tank D-101, a deacidification resin fixed bed D-102 and a product storage tank D-103 connected in sequence; wherein, the raw liquid storage tank D-101 is provided with a feeding pipeline S-701 for realizing continuous feeding of liquid lithium hexafluorophosphate raw material; preferably, in this embodiment, a liquid material outlet pipeline S-702 is provided between the bottom of the raw liquid storage tank D-101 and the bottom of the deacidification resin fixed bed D-102, and a delivery pump M-201 is provided on the liquid material outlet pipeline S-702.

[0020] Preferably, in the present embodiment, the upper ends of the raw liquid storage tank D-101, the deacidification resin fixed bed D-102 and the product storage tank D-103 are respectively provided with a material inlet, a nitrogen inlet and a vent; wherein each nitrogen inlet is respectively connected to the nitrogen pipeline S-707, and each vent is respectively connected to the vent pipeline S-708; preferably, in the present embodiment, the lower part of the raw liquid storage tank D-101 is installed with a first thermometer T-401, and the upper part thereof is respectively installed with a first liquid level gauge L-501 and a first pressure gauge P-601.

[0021] In this embodiment, the deacidification resin fixed bed D-102 is filled with deacidification resin, and the effective group of the deacidification resin is a tertiary amine group Ph-CH2-NR1R2, wherein Ph is the skeleton benzene ring of the resin, and R1 or R2 is a hydrogen atom, an alkyl group or a pyridine group -PY; in the deacidification resin fixed bed D-102, the liquid lithium hexafluorophosphate raw material replaces the carbonate solvent in the deacidification resin fixed bed D-102 from bottom to top; a flow meter F-801 is provided on the connecting discharge pipeline S-704 between the deacidification resin fixed bed D-102 and the product storage tank D-103, and the liquid lithium hexafluorophosphate after deacidification flows into the product storage tank D-103 through the discharge pipeline S-704; Preferably, in the present embodiment, a jacket JT-901 is welded on the outer periphery of the cylinder of the deacidification resin fixed bed D-102, which is used to pass refrigerant to extract heat from the material in the deacidification resin fixed bed D-102; wherein, the lower part of the jacket JT-901 is connected to the refrigerant feed pipeline S-705, and the upper part thereof is connected to the refrigerant discharge pipeline S-706; further preferably, in the present embodiment, a regulating valve V-301 is installed on the refrigerant discharge pipeline S-706, which is used to adjust the refrigerant flow rate and thus adjust the temperature of the material in the fixed bed; and a second thermometer T-402 is installed on the lower side of the deacidification resin fixed bed D-102, and a second pressure gauge P-602 is installed on the upper part thereof.

[0022] Preferably, in this embodiment, a third thermometer T-403 is installed at the lower part of the product storage tank D-103, and a third pressure gauge P-602 and a second level gauge L-502 are installed at the upper part thereof.

[0023] Preferably, this embodiment further proposes a deacidification process for liquid lithium hexafluorophosphate, wherein the liquid lithium hexafluorophosphate raw material is deacidified using the deacidification device for liquid lithium hexafluorophosphate as described above; the liquid lithium hexafluorophosphate raw material is a lithium hexafluorophosphate carbonate solution obtained by a synthesis reaction between lithium fluoride and phosphorus pentafluoride; Preferably, in this embodiment, the liquid hourly space velocity of the liquid lithium hexafluorophosphate passing through the deacidification resin fixed bed D-102 is in the range of 0.5-10h -1 , more preferably 1-8h -1 The liquid hourly space velocity refers to the ratio between the volume flow rate of liquid lithium hexafluorophosphate and the preset fixed liquid volume of the deacidification resin fixed bed D-102, and the unit is h -1 .

[0024] Preferably, in this embodiment, the inner diameter range of the deacidification resin fixed bed D-102 is 80-120 mm, the filling height of the deacidification resin is 0.25-0.35 m, and the filling volume of the deacidification resin is 1.5-2.5 liters; and / or before continuously feeding the deacidification resin fixed bed D-102; the deacidification resin in the deacidification resin fixed bed D-102 is soaked in a carbonate solvent for at least 20 hours (more preferably 22-30 hours), and then continuously (preferably at a rate of 0.8-1.8 liters / hour) replaced into the product storage tank D-103 with a carbonate solvent until the product storage tank D-103 is sampled and tested for moisture less than 10 ppm, and the deacidification resin fixed bed D-102 is deemed qualified and can be used for deacidification.

[0025] In this embodiment, the acidity of the liquid lithium hexafluorophosphate after deacidification is no more than 50 ppm.

[0026] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0027] On the basis of the above implementation contents, in order to verify the technical effects achieved by this application, this application further proposes the following embodiments: Example 1: The inner diameter of the deacidification resin fixed bed D-102 is 100 mm; the height of the loaded deacidification resin is 0.3 m, and the volume of the deacidification resin is 2 liters; the effective group of the deacidification resin is an alkyl tertiary amine group, and the group structure is Ph-CH2-N(CH3)2; the deacidification resin in the deacidification resin fixed bed D-102 is soaked in high-purity EMC solvent for 24 hours, and then continuously replaced into the product storage tank D-103 with high-purity EMC solvent at a flow rate of 1 liter / hour, until the product storage tank D-103 is sampled and tested for moisture less than 10 ppm, the deacidification resin fixed bed D-102 is deemed qualified and can be used for deacidification; The EMC liquid lithium salt (i.e., liquid lithium hexafluorophosphate raw material) with a total acidity of 620 ppm is stored in the raw material liquid storage tank D-101, and the delivery pump M-201 is started to allow the EMC liquid lithium salt to replace the EMC solvent in the deacidification resin fixed bed D-102 from bottom to top. The density of the EMC liquid lithium salt is 1.2 g / cm 3 , adjust the flow rate to 2.4 kg / h, the volume flow rate to 2 liters / h, and the volume liquid hourly space velocity to 1h -1 ; The material in the product storage tank D-103 was sampled and the acidity of the deacidified liquid lithium hexafluorophosphate was determined according to the standard HG / T 4067-2015 "Lithium Hexafluorophosphate Electrolyte" 5.10 Free Acid. The acidity was 16ppm, which met the requirements for preparing the electrolyte.

[0028] Example 2: The remaining technical solutions of Example 2 are the same as those of Example 1, except that in Example 2, the volume liquid hourly space velocity is 2h -1 ; Sample the material in the product storage tank D-103 and determine the acidity of the deacidified liquid lithium hexafluorophosphate according to standard HG / T 4067-2015 "Lithium Hexafluorophosphate Electrolyte" 5.10 Free Acid. The acidity is 18ppm, which meets the needs of preparing the electrolyte.

[0029] Example 3: The remaining technical solutions of Example 3 are the same as those of Example 1, except that in Example 3, the volume liquid hourly space velocity is 3h -1 ; Sample the material in the product storage tank D-103 and determine the acidity of the deacidified liquid lithium hexafluorophosphate according to standard HG / T 4067-2015 "Lithium Hexafluorophosphate Electrolyte" 5.10 Free Acid. The acidity is 22ppm, which meets the needs of preparing the electrolyte.

[0030] Embodiment 4: The remaining technical scheme of this embodiment 4 is the same as that of embodiment 1, except that in this embodiment 4, the volume liquid hourly space velocity is 4h -1; Sample the material in the product storage tank D-103, and determine the acidity of the deacidified liquid lithium hexafluorophosphate according to standard HG / T 4067-2015 "Lithium Hexafluorophosphate Electrolyte" 5.10 Free Acid. The acidity is 26ppm, which meets the needs of preparing the electrolyte.

[0031] Example 5: The remaining technical solutions of Example 5 are the same as those of Example 1, except that in Example 5, the volume liquid hourly space velocity is 5h -1 ; Sample the material in the product storage tank D-103 and determine the acidity of the deacidified liquid lithium hexafluorophosphate according to standard HG / T 4067-2015 "Lithium Hexafluorophosphate Electrolyte" 5.10 Free Acid. The acidity is 31ppm, which meets the needs of preparing the electrolyte.

[0032] Example 6: The remaining technical solutions of Example 6 are the same as those of Example 1, except that in Example 6, the volume liquid hourly space velocity is 6h -1 ; Sample the material in the product storage tank D-103 and determine the acidity of the deacidified liquid lithium hexafluorophosphate according to standard HG / T 4067-2015 "Lithium Hexafluorophosphate Electrolyte" 5.10 Free Acid. The acidity is 37ppm, which meets the needs of preparing the electrolyte.

[0033] Example 7: The remaining technical solutions of Example 7 are the same as those of Example 1, except that in Example 7, the volume liquid hourly space velocity is 8h -1 ; Sample the material in the product storage tank D-103, and determine the acidity of the deacidified liquid lithium hexafluorophosphate according to standard HG / T 4067-2015 "Lithium Hexafluorophosphate Electrolyte" 5.10 Free Acid. The acidity is 45ppm, which meets the needs of preparing the electrolyte.

[0034] Example 8: The inner diameter of the deacidification resin fixed bed D-102 is 100 mm; the height of the loaded deacidification resin is 0.3 m, and the volume of the deacidification resin is 2 liters; the effective group of the deacidification resin is an alkyl tertiary amine group, and the group structure is Ph-CH2-NH-PY, wherein Ph is a resin skeleton benzene ring, and PY is a pyridyl six-membered ring; the deacidification resin in the deacidification resin fixed bed D-102 is soaked in a high-purity EMC solvent for 24 hours, and then continuously replaced into the product storage tank D-103 with a high-purity EMC solvent at a flow rate of 1 liter / hour, until the product storage tank D-103 is sampled and tested for moisture less than 10 ppm, the deacidification resin fixed bed D-102 is deemed qualified and can be used for deacidification; The EMC liquid lithium salt (i.e., liquid lithium hexafluorophosphate raw material) with a total acidity of 440 ppm is stored in the raw material liquid storage tank D-101, and the delivery pump M-201 is started to allow the EMC liquid lithium salt to replace the EMC solvent in the deacidification resin fixed bed D-102 from bottom to top. The density of the EMC liquid lithium salt is 1.2 g / cm 3 , adjust the flow rate to 2.4 kg / h, the volume flow rate to 2 liters / h, and the volume liquid hourly space velocity to 1h -1 ; The material in the product storage tank D-103 was sampled and the acidity of the deacidified liquid lithium hexafluorophosphate was determined according to standard HG / T 4067-2015 "Lithium Hexafluorophosphate Electrolyte" 5.10 Free Acid. The acidity was 18ppm, which met the requirements for preparing the electrolyte.

[0035] Example 9: The remaining technical solutions of Example 9 are the same as those of Example 8, except that in Example 9, the volume liquid hourly space velocity is 2h -1 ; Sample the material in the product storage tank D-103 and determine the acidity of the deacidified liquid lithium hexafluorophosphate according to standard HG / T 4067-2015 "Lithium Hexafluorophosphate Electrolyte" 5.10 Free Acid. The acidity is 20ppm, which meets the needs of preparing the electrolyte.

[0036] Embodiment 10: The remaining technical solutions of this embodiment 10 are the same as those of embodiment 8, except that in this embodiment 10, the volume liquid hourly space velocity is 3h -1 ; Sample the material in the product storage tank D-103, and determine the acidity of the deacidified liquid lithium hexafluorophosphate according to standard HG / T 4067-2015 "Lithium Hexafluorophosphate Electrolyte" 5.10 Free Acid. The acidity is 23ppm, which meets the needs of preparing the electrolyte. Example 11: The remaining technical solutions of Example 11 are the same as those of Example 8, except that in Example 11, the volume liquid hourly space velocity is 4h -1 ; Sample the material in the product storage tank D-103 and determine the acidity of the deacidified liquid lithium hexafluorophosphate according to standard HG / T 4067-2015 "Lithium Hexafluorophosphate Electrolyte" 5.10 Free Acid. The acidity is 27ppm, which meets the needs of preparing the electrolyte.

[0037] Example 12: The remaining technical solutions of Example 12 are the same as those of Example 8, except that in Example 12, the volume liquid hourly space velocity is 5h -1 ; Sample the material in the product storage tank D-103 and determine the acidity of the deacidified liquid lithium hexafluorophosphate according to standard HG / T 4067-2015 "Lithium Hexafluorophosphate Electrolyte" 5.10 Free Acid. The acidity is 32ppm, which meets the needs of preparing the electrolyte.

[0038] Example 13: The remaining technical solutions of Example 13 are the same as those of Example 8, except that in Example 13, the volume liquid hourly space velocity is 6h -1 ; Sample the material in the product storage tank D-103, and determine the acidity of the deacidified liquid lithium hexafluorophosphate according to standard HG / T 4067-2015 "Lithium Hexafluorophosphate Electrolyte" 5.10 Free Acid. The acidity is 39ppm, which meets the needs of preparing the electrolyte.

[0039] Example 14: The remaining technical solutions of Example 14 are the same as those of Example 8, except that in Example 14, the volume liquid hourly space velocity is 8h -1 ; Sample the material in the product storage tank D-103, and determine the acidity of the deacidified liquid lithium hexafluorophosphate according to standard HG / T 4067-2015 "Lithium Hexafluorophosphate Electrolyte" 5.10 Free Acid. The acidity is 46ppm, which meets the needs of preparing the electrolyte.

[0040] Example 15: The rest of the technical solutions of Example 15 are the same as those of any of Examples 1-14, except that, in Example 15, the EMC solvent is replaced with a DMC solvent; similar deacidification effects can also be obtained.

[0041] Comparative Example 1: The remaining technical solutions of this comparative example 1 are the same as those of Example 1, except that in this comparative example 1, the volume liquid hourly space velocity is 13h -1 ; Samples were taken from the material in the product storage tank D-103, and the acidity of the deacidified liquid lithium hexafluorophosphate was determined according to standard HG / T 4067-2015 "Lithium Hexafluorophosphate Electrolyte" 5.10 Free Acid, and the acidity was 86ppm; this could not meet the needs of preparing the electrolyte.

[0042] Comparative Example 2: The remaining technical solutions of this comparative example 2 are the same as those of Example 1, except that in this comparative example 2, the volume liquid hourly space velocity is 15h -1 ; Samples were taken from the material in the product storage tank D-103, and the acidity of the deacidified liquid lithium hexafluorophosphate was determined according to standard HG / T 4067-2015 "Lithium Hexafluorophosphate Electrolyte" 5.10 Free Acid. The acidity was 113ppm, which did not meet the requirements for preparing the electrolyte.

[0043] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0044] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A deacidification device for liquid lithium hexafluorophosphate, characterized in that: It includes a raw liquid storage tank (D-101), a deacidification resin fixed bed (D-102) and a product storage tank (D-103) which are connected in sequence; wherein, The raw material liquid storage tank (D-101) is provided with a feed pipeline (S-701) for realizing continuous feeding of liquid lithium hexafluorophosphate raw material; The deacidification resin fixed bed (D-102) is filled with deacidification resin, and the effective The group is a tertiary amine group Ph-CH2-N (R1R2), wherein Ph is a skeleton benzene ring of the resin, and R1 or R2 is a hydrogen atom, an alkyl group or a pyridine group -PY; in the deacidification resin fixed bed (D-102), the liquid lithium hexafluorophosphate raw material displaces the carbonate solvent in the deacidification resin fixed bed (D-102) from bottom to top; The connection between the deacidification resin fixed bed (D-102) and the product storage tank (D-103) A flow meter (F-801) is provided on the discharge pipeline (S-704), and the liquid lithium hexafluorophosphate after deacidification flows into the product storage tank (D-103) through the discharge pipeline (S-704).

2. The deacidification device for liquid lithium hexafluorophosphate according to claim 1, characterized in that: A liquid material outlet pipeline (S-702) is provided between the bottom of the raw material liquid storage tank (D-101) and the bottom of the deacidification resin fixed bed (D-102), and a delivery pump (M-201) is provided on the liquid material outlet pipeline (S-702).

3. The deacidification device for liquid lithium hexafluorophosphate according to claim 1, characterized in that: The upper ends of the raw liquid storage tank (D-101), the deacidification resin fixed bed (D-102) and the product storage tank (D-103) are respectively provided with a material inlet, a nitrogen inlet and a vent; wherein each nitrogen inlet is respectively connected to a nitrogen pipeline (S-707), and each vent is respectively connected to a vent pipeline (S-708).

4. The deacidification device for liquid lithium hexafluorophosphate according to claim 1, characterized in that: A first thermometer (T-401) is installed at the lower part of the raw liquid storage tank (D-101), and a first liquid level meter (L-501) and a first pressure gauge (P-601) are installed at the upper part thereof.

5. The deacidification device for liquid lithium hexafluorophosphate according to claim 1, characterized in that: A jacket (JT-901) is welded on the outer periphery of the cylinder of the deacidification resin fixed bed (D-102) for introducing a refrigerant to extract heat from the material in the deacidification resin fixed bed (D-102); wherein the lower part of the jacket (JT-901) is connected to a refrigerant feed pipeline (S-705), and the upper part thereof is connected to a refrigerant discharge pipeline (S-706).

6. The deacidification device for liquid lithium hexafluorophosphate according to claim 5, characterized in that: The refrigerant discharge pipeline (S-706) is equipped with a regulating valve (V-301) for adjusting the refrigerant flow and thus adjusting the material temperature in the fixed bed; and a second thermometer (T-402) is installed on the lower side of the deacidification resin fixed bed (D-102), and a second pressure gauge (P-602) is installed on the upper part.

7. The deacidification device for liquid lithium hexafluorophosphate according to claim 1, characterized in that: A third thermometer (T-403) is installed at the lower part of the product storage tank (D-103), and a third pressure gauge (P-602) and a second liquid level gauge (L-502) are installed at the upper part thereof.

8. A deacidification process for liquid lithium hexafluorophosphate, characterized in that: According to claims 1-7 The deacidification device for liquid lithium hexafluorophosphate deacidifies liquid lithium hexafluorophosphate raw material; the liquid lithium hexafluorophosphate raw material is a lithium hexafluorophosphate carbonate solution obtained by a synthesis reaction between lithium fluoride and phosphorus pentafluoride, and the acidity of the liquid lithium hexafluorophosphate after deacidification does not exceed 50 ppm.

9. The deacidification process of liquid lithium hexafluorophosphate according to claim 8, characterized in that: The liquid hourly space velocity of liquid lithium hexafluorophosphate passing through the deacidification resin fixed bed (D-102) is in the range of 0.5-10h -1 , more preferably 1-8h -1 The liquid hourly space velocity refers to the ratio of the volume flow rate of the liquid lithium hexafluorophosphate discharge to the preset fixed liquid volume of the deacidification resin fixed bed (D-102), and the unit is h -1 .

10. The deacidification process of liquid lithium hexafluorophosphate according to claim 8, characterized in that: The inner diameter of the deacidification resin fixed bed (D-102) is in the range of 80-120 mm, the filling height of the deacidification resin is in the range of 0.25-0.35 m, and the filling volume of the deacidification resin is in the range of 1.5-2.5 liters; and / or before continuously feeding the deacidification resin fixed bed (D-102); the deacidification resin in the deacidification resin fixed bed (D-102) is soaked in a carbonate solvent for at least 20 hours, and then continuously replaced into the product storage tank (D-103) with a carbonate solvent until the product storage tank (D-103) is sampled and tested for moisture less than 10 ppm, and the deacidification resin fixed bed (D-102) is deemed qualified and can be used for deacidification.

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