CN115771906A - Method for preparing lithium hexafluorophosphate through solid-solid reaction - Google Patents
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- -1 lithium hexafluorophosphate Chemical compound 0.000 title claims abstract description 85
- 238000006243 chemical reaction Methods 0.000 title claims abstract description 59
- 239000007787 solid Substances 0.000 title claims abstract description 36
- 238000000034 method Methods 0.000 title claims abstract description 32
- WEVYAHXRMPXWCK-UHFFFAOYSA-N Acetonitrile Chemical compound CC#N WEVYAHXRMPXWCK-UHFFFAOYSA-N 0.000 claims abstract description 87
- 239000011259 mixed solution Substances 0.000 claims abstract description 29
- 239000007788 liquid Substances 0.000 claims abstract description 24
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 claims abstract description 22
- 239000000203 mixture Substances 0.000 claims abstract description 19
- 238000001914 filtration Methods 0.000 claims abstract description 18
- 239000013078 crystal Substances 0.000 claims abstract description 16
- 239000000843 powder Substances 0.000 claims abstract description 15
- 238000002156 mixing Methods 0.000 claims abstract description 12
- 239000000706 filtrate Substances 0.000 claims abstract description 11
- 229910004261 CaF 2 Inorganic materials 0.000 claims abstract description 10
- 238000010438 heat treatment Methods 0.000 claims abstract description 8
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 8
- 238000002425 crystallisation Methods 0.000 claims description 17
- 230000008025 crystallization Effects 0.000 claims description 17
- 239000000047 product Substances 0.000 claims description 9
- 239000000126 substance Substances 0.000 claims description 6
- 238000001816 cooling Methods 0.000 claims description 5
- 230000035484 reaction time Effects 0.000 claims description 5
- 238000000926 separation method Methods 0.000 claims description 5
- 239000007795 chemical reaction product Substances 0.000 claims 1
- 238000011084 recovery Methods 0.000 claims 1
- 238000012824 chemical production Methods 0.000 abstract description 2
- PQXKHYXIUOZZFA-UHFFFAOYSA-M lithium fluoride Chemical compound [Li+].[F-] PQXKHYXIUOZZFA-UHFFFAOYSA-M 0.000 description 20
- 230000008569 process Effects 0.000 description 9
- 239000012535 impurity Substances 0.000 description 6
- 238000002360 preparation method Methods 0.000 description 6
- 239000000243 solution Substances 0.000 description 6
- 239000003792 electrolyte Substances 0.000 description 4
- 239000007789 gas Substances 0.000 description 4
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 description 3
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- 150000001875 compounds Chemical class 0.000 description 3
- 229910001416 lithium ion Inorganic materials 0.000 description 3
- 238000010899 nucleation Methods 0.000 description 3
- 239000000376 reactant Substances 0.000 description 3
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 2
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 2
- 229910013870 LiPF 6 Inorganic materials 0.000 description 2
- 229910001290 LiPF6 Inorganic materials 0.000 description 2
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 2
- 230000000536 complexating effect Effects 0.000 description 2
- 238000010668 complexation reaction Methods 0.000 description 2
- 230000007797 corrosion Effects 0.000 description 2
- 238000005260 corrosion Methods 0.000 description 2
- 238000000354 decomposition reaction Methods 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 239000008151 electrolyte solution Substances 0.000 description 2
- 229910052744 lithium Inorganic materials 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 230000006911 nucleation Effects 0.000 description 2
- 238000003746 solid phase reaction Methods 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- 238000003786 synthesis reaction Methods 0.000 description 2
- 238000012935 Averaging Methods 0.000 description 1
- BTBUEUYNUDRHOZ-UHFFFAOYSA-N Borate Chemical compound [O-]B([O-])[O-] BTBUEUYNUDRHOZ-UHFFFAOYSA-N 0.000 description 1
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 1
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 1
- 229910012851 LiCoO 2 Inorganic materials 0.000 description 1
- 229910013872 LiPF Inorganic materials 0.000 description 1
- 101150058243 Lipf gene Proteins 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 150000004649 carbonic acid derivatives Chemical class 0.000 description 1
- 230000006837 decompression Effects 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000010494 dissociation reaction Methods 0.000 description 1
- 230000005593 dissociations Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000007772 electrode material Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000004880 explosion Methods 0.000 description 1
- 229910000041 hydrogen chloride Inorganic materials 0.000 description 1
- IXCSERBJSXMMFS-UHFFFAOYSA-N hydrogen chloride Substances Cl.Cl IXCSERBJSXMMFS-UHFFFAOYSA-N 0.000 description 1
- 229910000040 hydrogen fluoride Inorganic materials 0.000 description 1
- 229910003002 lithium salt Inorganic materials 0.000 description 1
- 159000000002 lithium salts Chemical class 0.000 description 1
- IGILRSKEFZLPKG-UHFFFAOYSA-M lithium;difluorophosphinate Chemical compound [Li+].[O-]P(F)(F)=O IGILRSKEFZLPKG-UHFFFAOYSA-M 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 239000012071 phase Substances 0.000 description 1
- OBCUTHMOOONNBS-UHFFFAOYSA-N phosphorus pentafluoride Chemical compound FP(F)(F)(F)F OBCUTHMOOONNBS-UHFFFAOYSA-N 0.000 description 1
- 239000007774 positive electrode material Substances 0.000 description 1
- 230000036632 reaction speed Effects 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 239000007790 solid phase Substances 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
Classifications
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
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Abstract
The invention discloses a method for preparing lithium hexafluorophosphate through solid-solid reaction, and belongs to the technical field of chemical production. A method for preparing lithium hexafluorophosphate by solid-solid reaction comprises the following steps; (1) Mixing PCl 5 And CaF 2 PF is obtained after mixing reaction 5 (ii) a (2) LiF is added into a flask containing acetonitrile, and PF is added 5 Reacting the mixed solution; (3) heating the reaction mixed solution in water bath, and filtering; (4) Putting the filtrate in a low-temperature vacuum environment to volatilize acetonitrile to obtain complex mixed liquid; (5) Filtering the complex mixture to obtain a complex Li (CH) 3 CN) 4 PF 6 Vacuum filtering to obtain lithium hexafluorophosphate powder, and dissolving in ether to obtain mixed lithium hexafluorophosphate liquid; (6) And (3) dynamically crystallizing the lithium hexafluorophosphate mixed solution to obtain lithium hexafluorophosphate crystals. The lithium hexafluorophosphate prepared by the method has good crystallinity and high purity. The lithium hexafluorophosphate prepared by the invention is applied to the battery,high conductivity and high charge and discharge capacity.
Description
Technical Field
The invention belongs to the technical field of chemical production, and particularly relates to a method for preparing lithium hexafluorophosphate through solid-solid reaction.
Background
The lithium ion battery has the advantages of long cycle life, no pollution, high cycle efficiency and the like, and is widely used in the fields of small-sized mobile power supplies, electric vehicles, electric automobiles and the like.
The most widely used lithium ion battery electrolyte in lithium ion batteries is lithium hexafluorophosphate (LiPF) 6 ). Lithium hexafluorophosphate is white crystal or powder, has strong deliquescence, is easy to dissolve in water, and is also dissolved in organic solvents such as ether, low-concentration methanol, ethanol, acetone, carbonates and the like. Lithium hexafluorophosphate has poor stability, can be decomposed into lithium fluoride and phosphorus pentafluoride in a small amount when heated to 60 ℃, and can be decomposed in a large amount when heated to 175-185 ℃.
The electrolyte solution has a series of advantages of easy dissociation in electrolyte, improved electrolyte conductivity, simple synthesis process and the like, and can form an SEI film on the surface of an electrode material to inhibit the corrosion of a current collector. Although it is poor in thermal stability, it is easily decomposed by heat. However, the overall performance of lithium hexafluorophosphate is still optimal compared to other novel electrolyte lithium salts, such as lithium difluorooxalato borate, lithium difluorophosphate, and the like.
Because the lithium hexafluorophosphate is high in synthesis difficulty, the whole production process relates to high and low temperature, anhydrous and oxygen-free operation, high purity refining and strong corrosion, the requirements on equipment and operators are high, and the process difficulty is very high.
The reactions involved in the more common preparation methods of lithium hexafluorophosphate in the prior art are as follows,
(1)PCl 5 +5HF→PF 5 +5HCl
(2)LiF+PF 5 →LiPF 6
in the preparation method, PF is prepared 5 Is a solid-state PCl 5 Reacting with gaseous HFThe process of (2) is easy to cause explosion, the temperature is difficult to control, the reaction pressure is high, the requirement on a reaction instrument is high, and the PF is prepared 5 In addition, the PF generates harmful gas hydrogen chloride 5 The purity of (2) is also low.
In the prior art, the preparation method of lithium hexafluorophosphate is easy to bring in metal impurities, and has low reaction temperature and low reaction speed, and the obtained lithium hexafluorophosphate has low conductivity and low charge-discharge capacity when applied to batteries.
Disclosure of Invention
The invention aims to overcome the technical defects, provides a method for preparing lithium hexafluorophosphate through solid-solid reaction, and solves the technical problems that impurities are easily brought in and harmful gases are generated in the process of preparing lithium hexafluorophosphate by using the preparation method in the prior art, and the lithium hexafluorophosphate applied to a battery is low in conductivity and low in charge and discharge capacity.
In order to achieve the technical purpose, the technical scheme of the invention provides a method for preparing lithium hexafluorophosphate by solid-solid reaction, which comprises the following steps;
(1) Mixing solid PCl 5 And solid CaF 2 Mixing the mixture and putting the mixture into a tubular furnace for curing reaction to obtain PF 5 The temperature of the curing reaction is 230-320 ℃, the reaction time is 15-18h, the CaF 2 The amount of substance (b) is PCl 5 3-4 times of the total weight of the composition;
the reaction equation of the reaction process is
5CaF 2 +2PCl 5 →5CaCl 2 +2PF 5
The two reactant molecules are contacted with each other by diffusion with the rise of temperature, and then the two reactant molecules are subjected to chemical action to generate product molecules, wherein the product molecules in the reactants only exist as impurities or defects, and when the product molecules are further accumulated and reach a certain size, crystal nuclei of the product can appear, the nucleation process is completed, and the nucleation process is carried out along with the growth of the crystal nuclei. After reaching a certain size, an independent crystalline phase of the product appears. In summary, the solid phase reaction goes through four stages, diffusion-reaction-nucleation growth. In order to ensure the reaction rate of the two solids in the reaction process, the particle size of the two solids is smaller, so that the solid phase inversion can be ensuredSpeed of response, in addition to ensuring PF 5 Yield of CaF 2 In excess. The invention prepares PF 5 The process of (2) has no participation of corrosive gas hydrogen fluoride, is safe and pollution-free, and the PF produced in addition 5 High purity and no other impurity gas.
(2) LiF was added to a flask containing acetonitrile and the PF was added 5 Carrying out chemical reaction to obtain reaction mixed liquid after the reaction is finished;
(3) Heating the reaction mixed solution in a water bath at the temperature of 60-70 ℃, and filtering to obtain a filtrate;
(4) Placing the filtrate in a low-temperature vacuum environment, wherein the temperature in the low-temperature vacuum environment is-30 ℃ to-10 ℃, the time for volatilizing acetonitrile is 12-18h, volatilizing the acetonitrile, and recovering the acetonitrile to obtain complex mixed liquid;
(5) Filtering the complex mixed solution to obtain a complex Li (CH) 3 CN) 4 PF 6 Complexing compound Li (CH) 3 CN) 4 PF 6 Vacuum filtering at 5-10 deg.C to obtain lithium hexafluorophosphate powder, dissolving the lithium hexafluorophosphate powder in diethyl ether to obtain lithium hexafluorophosphate mixed solution;
because the acetonitrile can not dissolve LiF or react, liF and acetonitrile are mixed firstly, and then PF is introduced 5 Acetonitrile is less active than LiF, so PF 5 Firstly reacts with LiF to generate LPF 6 Acetonitrile will then react with LiPF 6 Formation of the Complex Li (CH) 3 CN) 4 PF 6 This complex is stable and the CH is subsequently removed under reduced pressure 3 No decomposition occurs during the process of CN due to Li (CH) 3 CN) 4 PF 6 The solubility in acetonitrile is obviously changed along with the temperature, and the complex Li (CH) is obtained by decompression volatilization at the temperature of-30 ℃ to-10 DEG C 3 CN) 4 PF 6 . Then heating in vacuum to remove CH in the complex 3 CN, obtaining lithium hexafluorophosphate powder, dissolving the lithium hexafluorophosphate powder in diethyl ether, and then carrying out the next step of dynamic crystallization to obtain lithium hexafluorophosphate crystals with high purity.
Since acetonitrile is not the same as that in LiPF6 obtained by the above-mentioned production methodThe impurities react with or dissolve them, so that the complex Li (CH) formed can be easily converted 3 CN) 4 PF 6 Separating from impurities, and removing CH by vacuum decomposition 3 CN, the LiPF6 with high purity and large specific surface area can be prepared. The reaction formula is as follows:
LiF+PF 5 +4CH 3 CN→Li(CH 3 CN) 4 PF 6
(6) Introducing the lithium hexafluorophosphate mixed solution into a crystallization tank, cooling the lithium hexafluorophosphate mixed solution, and performing dynamic crystallization at the temperature of-20 ℃ for 15-20h to obtain a solid-liquid mixture after all lithium hexafluorophosphate solids are crystallized and separated out;
(7) And introducing the solid-liquid mixture into a constant temperature bath for solid-liquid separation, and separating for 2 hours to obtain lithium hexafluorophosphate crystals.
The method carries out dynamic crystallization under certain temperature regulation, solves the problems that the traditional static crystallization technology needs a crushing process, and the product is powdery, has poor fluidity, unstable product quality, poor crystallinity and the like, and ensures that most lithium hexafluorophosphate crystals are separated out, and achieves the effects of good crystal fluidity and stable product quality.
Compared with the prior art, the invention has the beneficial effects that: the invention first passes through PCl 5 And CaF 2 Preparation of PF by solid phase reaction 5 Then the complex compound Li (CH) is prepared by the complexation reaction of acetonitrile 3 CN) 4 PF 6 And acetonitrile is removed through simple treatment, and finally lithium hexafluorophosphate crystals are obtained through a dynamic crystallization mode. PF prepared 5 The lithium hexafluorophosphate powder is prepared by a complexation method, and has high purity, large specific surface area, and good crystallinity and high purity of the lithium hexafluorophosphate obtained by dynamic crystallization. When the lithium hexafluorophosphate prepared by the method is applied to the battery, the conductivity is high, and the charge and discharge capacity is high.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
Example 1
The specific embodiment provides a method for preparing lithium hexafluorophosphate through solid-solid reaction, which comprises the following steps;
(1) Mixing solid PCl 5 And solid CaF 2 Mixing, putting into a tube furnace for curing reaction to obtain PF 5 The temperature of the curing reaction is 230 ℃, the reaction time is 15h 2 The amount of substance(s) is PCl 5 3 times of the total weight of the composition;
(2) LiF is added into a three-neck flask containing acetonitrile, and the PF is added 5 Carrying out chemical reaction to obtain reaction mixed liquid after the reaction is finished;
(3) Heating the reaction mixed solution in a water bath at the temperature of 60 ℃, and filtering to obtain a filtrate;
(4) Placing the filtrate in a low-temperature vacuum environment, wherein the temperature in the low-temperature vacuum environment is-30 ℃, the volatilization time of acetonitrile is 12 hours, the acetonitrile is volatilized, and the acetonitrile is recovered to obtain complex mixture;
(5) Filtering the complex mixed solution to obtain a complex Li (CH) 3 CN) 4 PF 6 The complex Li (CH) 3 CN) 4 PF 6 Vacuum filtering at 5 ℃ to obtain lithium hexafluorophosphate powder, and dissolving the lithium hexafluorophosphate powder in diethyl ether to obtain a lithium hexafluorophosphate mixed solution;
(6) Introducing the lithium hexafluorophosphate mixed solution into a crystallization tank, cooling the lithium hexafluorophosphate mixed solution, and performing dynamic crystallization at the temperature of-20 ℃ for 15h to obtain a solid-liquid mixture after all lithium hexafluorophosphate solids are crystallized and separated out;
(7) And (3) introducing the solid-liquid mixture into a constant temperature bath for solid-liquid separation, and separating for 2 hours to obtain lithium hexafluorophosphate crystals.
Example 2
The specific embodiment provides a method for preparing lithium hexafluorophosphate through solid-solid reaction, which comprises the following steps;
(1) Mixing solid PCl 5 And solid CaF 2 Mixing, putting into a tube furnace for curing reaction to obtain PF 5 The temperature of the curing reaction is 320 ℃, the reaction time is 18h 2 The amount of substance(s) is PCl 5 4 times of the total weight of the composition;
(2) Adding LiF into a three-neck flask containing acetonitrile, and adding the PF 5 Carrying out chemical reaction to obtain reaction mixed liquid after the reaction is finished;
(3) Heating the reaction mixed solution in a water bath at the temperature of 70 ℃, and filtering to obtain a filtrate;
(4) Placing the filtrate in a low-temperature vacuum environment, wherein the temperature in the low-temperature vacuum environment is-10 ℃, the time for volatilizing acetonitrile is 18h, volatilizing the acetonitrile, and recovering the acetonitrile to obtain a complex mixed solution;
(5) Filtering the complex mixed solution to obtain a complex Li (CH) 3 CN) 4 PF 6 The complex Li (CH) 3 CN) 4 PF 6 Vacuum filtering at 10 ℃ to obtain lithium hexafluorophosphate powder, and dissolving the lithium hexafluorophosphate powder in diethyl ether to obtain a lithium hexafluorophosphate mixed solution;
(6) Introducing the lithium hexafluorophosphate mixed solution into a crystallization tank, cooling the lithium hexafluorophosphate mixed solution, and performing dynamic crystallization at the temperature of-20 ℃ for 20 hours to obtain a solid-liquid mixture after all lithium hexafluorophosphate solids are crystallized and separated out;
(7) And (3) introducing the solid-liquid mixture into a constant temperature bath for solid-liquid separation, and separating for 2 hours to obtain lithium hexafluorophosphate crystals.
Example 3
The specific embodiment provides a method for preparing lithium hexafluorophosphate through solid-solid reaction, which comprises the following steps;
(1) Mixing solid PCl 5 And solid CaF 2 Mixing, putting into a tube furnace for curing reaction to obtain PF 5 The temperature of the curing reaction is 260 ℃, the reaction time is 17h 2 The amount of substance(s) is PCl 5 3.5 times of;
(2) Adding LiF into a three-port furnace filled with acetonitrileAdding the PF into the bottle 5 Carrying out chemical reaction to obtain reaction mixed liquid after the reaction is finished;
(3) Heating the reaction mixed solution in a water bath at 65 ℃, and filtering to obtain a filtrate;
(4) Placing the filtrate in a low-temperature vacuum environment, wherein the temperature in the low-temperature vacuum environment is-20 ℃, and the time for volatilizing acetonitrile is 16h, volatilizing the acetonitrile, and recovering the acetonitrile to obtain a complex mixed solution;
(5) Filtering the complex mixed solution to obtain a complex Li (CH) 3 CN) 4 PF 6 Complexing compound Li (CH) 3 CN) 4 PF 6 Vacuum filtering at 8 ℃ to obtain lithium hexafluorophosphate powder, and dissolving the lithium hexafluorophosphate powder in diethyl ether to obtain a lithium hexafluorophosphate mixed solution;
(6) Introducing the lithium hexafluorophosphate mixed solution into a crystallization tank, cooling the lithium hexafluorophosphate mixed solution, and performing dynamic crystallization at the temperature of-20 ℃ for 18 hours to obtain a solid-liquid mixture after all lithium hexafluorophosphate solids are crystallized and separated out;
(7) And introducing the solid-liquid mixture into a constant temperature bath for solid-liquid separation, and separating for 2 hours to obtain lithium hexafluorophosphate crystals.
Lithium hexafluorophosphate crystals prepared in examples 1 to 3, and a commercially available sample of lithium hexafluorophosphate were mixed in a volume ratio of DC to DMC of 1:1 as a solvent, to prepare a lithium hexafluorophosphate solution having a concentration of 1mol/L, measuring the conductivity of the solution using a conductivity meter model DDSJ-308A, measuring five times for each solution, and averaging the results as follows;
from the above data, it can be seen that the solution prepared from the lithium hexafluorophosphate crystal prepared by the preparation method of the present invention has high conductivity, and thus has good conductivity when applied to a lithium battery.
The lithium hexafluorophosphate crystals prepared in examples 1 to 3,and a commercially available lithium hexafluorophosphate sample, in a DC to DMC volume ratio of 1:1 as a solvent, a lithium hexafluorophosphate solution having a concentration of 1mol/L was prepared as a standard LiCoO 2 The constant current charge and discharge performance of the electrolyte solution is measured by using Land 2001A as a positive electrode material, and the measurement data of the first discharge condition are as follows;
from the above data, it can be seen that the lithium hexafluorophosphate prepared in the present invention has very good discharge performance when applied to batteries.
The above-described embodiments of the present invention should not be construed as limiting the scope of the present invention. Any other corresponding changes and modifications made according to the technical idea of the present invention should be included in the protection scope of the claims of the present invention.
Claims (9)
1. A method for preparing lithium hexafluorophosphate by solid-solid reaction is characterized by comprising the following steps;
(1) Mixing PCl 5 And CaF 2 Mixing the mixture and putting the mixture into a tubular furnace for curing reaction to obtain PF 5 ；
(2) LiF was added to a flask containing acetonitrile and the PF was added 5 Carrying out chemical reaction to obtain reaction mixed liquid after the reaction is finished;
(3) Heating the reaction mixed solution in water bath, and filtering to obtain a filtrate;
(4) Putting the filtrate in a low-temperature vacuum environment to volatilize acetonitrile to obtain complex mixed liquid;
(5) Filtering the complex mixed solution to obtain a complex Li (CH) 3 CN) 4 PF 6 The complex Li (CH) 3 CN) 4 PF 6 Vacuum filtering at 5-10 deg.C to obtain lithium hexafluorophosphate powder, dissolving the lithium hexafluorophosphate powder in diethyl ether to obtain lithium hexafluorophosphate mixed solution;
(6) Introducing the lithium hexafluorophosphate mixed solution into a crystallization tank, cooling the crystallization tank, performing dynamic crystallization, and obtaining a solid-liquid mixture after all lithium hexafluorophosphate solids are crystallized and separated out;
(7) And (3) introducing the solid-liquid mixture into a constant temperature bath for solid-liquid separation, and separating for 2 hours to obtain lithium hexafluorophosphate crystals.
2. The method of claim 1, wherein the PCl is a solid-solid reaction product of lithium hexafluorophosphate 5 And CaF 2 Are all solids.
3. The method for preparing lithium hexafluorophosphate by solid-solid reaction according to claim 1 or 2, wherein the temperature of said solid-solid reaction in step (1) is 230-320 ℃ and the reaction time is 15-18h.
4. The method of claim 3, wherein the CaF is a solid-solid reaction of lithium hexafluorophosphate 2 The amount of substance (b) is PCl 5 3-4 times of the total weight of the product.
5. The method for preparing lithium hexafluorophosphate through solid-solid reaction according to claim 1, wherein the temperature of the water bath heating is 60-70 ℃.
6. The method for preparing lithium hexafluorophosphate by solid-solid reaction according to claim 1, wherein the temperature of dynamic crystallization is-20 ℃ and the time is 15-20h.
7. The method for preparing lithium hexafluorophosphate through solid-solid reaction according to claim 1, wherein the temperature in the low temperature vacuum environment in the step (4) is-30 ℃ to-10 ℃.
8. The method for preparing lithium hexafluorophosphate through solid-solid reaction according to claim 7, wherein the time for volatilizing acetonitrile is 12-18h.
9. The method for preparing lithium hexafluorophosphate through solid-solid reaction according to claim 1, wherein the step (4) further comprises the recovery of acetonitrile.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102320584A (en) * | 2011-10-26 | 2012-01-18 | 核工业理化工程研究院华核新技术开发公司 | Method for preparing phosphorus pentafluoride |
| CN102976303A (en) * | 2012-12-12 | 2013-03-20 | 四川大学 | Method for preparing lithium hexafluorophosphate |
| CN106241840A (en) * | 2016-09-08 | 2016-12-21 | 甘肃立焘新能源科技发展有限公司 | The preparation method of a kind of lithium hexafluoro phosphate and preparation system |
| CN114715922A (en) * | 2022-02-18 | 2022-07-08 | 广东邦普循环科技有限公司 | Method for recycling lithium ion battery electrolyte |
-
2022
- 2022-11-29 CN CN202211514097.9A patent/CN115771906A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102320584A (en) * | 2011-10-26 | 2012-01-18 | 核工业理化工程研究院华核新技术开发公司 | Method for preparing phosphorus pentafluoride |
| CN102976303A (en) * | 2012-12-12 | 2013-03-20 | 四川大学 | Method for preparing lithium hexafluorophosphate |
| CN106241840A (en) * | 2016-09-08 | 2016-12-21 | 甘肃立焘新能源科技发展有限公司 | The preparation method of a kind of lithium hexafluoro phosphate and preparation system |
| CN114715922A (en) * | 2022-02-18 | 2022-07-08 | 广东邦普循环科技有限公司 | Method for recycling lithium ion battery electrolyte |
Non-Patent Citations (1)
| Title |
|---|
| 冉启文等: "分析化学 第4版", 31 August 2021, 北京：中国医药科技出版社, pages: 116 * |
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