CN116102028B - Preparation method of lithium tetrafluoroborate - Google Patents
Preparation method of lithium tetrafluoroborate Download PDFInfo
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- CN116102028B CN116102028B CN202211590560.8A CN202211590560A CN116102028B CN 116102028 B CN116102028 B CN 116102028B CN 202211590560 A CN202211590560 A CN 202211590560A CN 116102028 B CN116102028 B CN 116102028B
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- -1 lithium tetrafluoroborate Chemical compound 0.000 title claims abstract description 58
- 229910001496 lithium tetrafluoroborate Inorganic materials 0.000 title claims abstract description 55
- 238000002360 preparation method Methods 0.000 title abstract description 36
- 238000006243 chemical reaction Methods 0.000 claims abstract description 41
- XGZVUEUWXADBQD-UHFFFAOYSA-L lithium carbonate Chemical compound [Li+].[Li+].[O-]C([O-])=O XGZVUEUWXADBQD-UHFFFAOYSA-L 0.000 claims abstract description 35
- 229910052808 lithium carbonate Inorganic materials 0.000 claims abstract description 35
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 claims abstract description 30
- 239000011737 fluorine Substances 0.000 claims abstract description 30
- 229910052731 fluorine Inorganic materials 0.000 claims abstract description 30
- 238000000034 method Methods 0.000 claims abstract description 27
- 239000002904 solvent Substances 0.000 claims abstract description 20
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 claims abstract description 14
- 239000007787 solid Substances 0.000 claims abstract description 13
- KZMGYPLQYOPHEL-UHFFFAOYSA-N Boron trifluoride etherate Chemical compound FB(F)F.CCOCC KZMGYPLQYOPHEL-UHFFFAOYSA-N 0.000 claims abstract description 7
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims abstract description 6
- JXYQFUKJZRPXCZ-UHFFFAOYSA-N ethanol;trifluoroborane Chemical compound CCO.FB(F)F JXYQFUKJZRPXCZ-UHFFFAOYSA-N 0.000 claims abstract description 4
- 239000003759 ester based solvent Substances 0.000 claims abstract description 3
- 239000007788 liquid Substances 0.000 claims description 38
- 238000005406 washing Methods 0.000 claims description 7
- 230000008569 process Effects 0.000 claims description 3
- 230000035484 reaction time Effects 0.000 claims description 2
- 239000003792 electrolyte Substances 0.000 abstract description 13
- 239000002994 raw material Substances 0.000 abstract description 5
- 238000000746 purification Methods 0.000 abstract description 2
- 239000012535 impurity Substances 0.000 description 17
- 238000002425 crystallisation Methods 0.000 description 13
- 230000000052 comparative effect Effects 0.000 description 12
- 230000008025 crystallization Effects 0.000 description 11
- 238000001704 evaporation Methods 0.000 description 9
- 238000012360 testing method Methods 0.000 description 7
- 150000003839 salts Chemical class 0.000 description 6
- WTEOIRVLGSZEPR-UHFFFAOYSA-N boron trifluoride Substances FB(F)F WTEOIRVLGSZEPR-UHFFFAOYSA-N 0.000 description 5
- 239000012528 membrane Substances 0.000 description 5
- 239000000047 product Substances 0.000 description 5
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 4
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 description 4
- 230000008901 benefit Effects 0.000 description 4
- 230000008020 evaporation Effects 0.000 description 4
- 238000010438 heat treatment Methods 0.000 description 4
- 229910001416 lithium ion Inorganic materials 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 238000007789 sealing Methods 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- 229910015900 BF3 Inorganic materials 0.000 description 3
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 3
- 229910013063 LiBF 4 Inorganic materials 0.000 description 3
- 230000009471 action Effects 0.000 description 3
- 229910052796 boron Inorganic materials 0.000 description 3
- 229910013870 LiPF 6 Inorganic materials 0.000 description 2
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 229910052810 boron oxide Inorganic materials 0.000 description 2
- 229910002092 carbon dioxide Inorganic materials 0.000 description 2
- 239000001569 carbon dioxide Substances 0.000 description 2
- JKWMSGQKBLHBQQ-UHFFFAOYSA-N diboron trioxide Chemical compound O=BOB=O JKWMSGQKBLHBQQ-UHFFFAOYSA-N 0.000 description 2
- BBLSYMNDKUHQAG-UHFFFAOYSA-L dilithium;sulfite Chemical compound [Li+].[Li+].[O-]S([O-])=O BBLSYMNDKUHQAG-UHFFFAOYSA-L 0.000 description 2
- 238000011010 flushing procedure Methods 0.000 description 2
- 230000005484 gravity Effects 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- 229910052749 magnesium Inorganic materials 0.000 description 2
- 239000011777 magnesium Substances 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 229920001343 polytetrafluoroethylene Polymers 0.000 description 2
- 239000004810 polytetrafluoroethylene Substances 0.000 description 2
- 239000000376 reactant Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- KMTRUDSVKNLOMY-UHFFFAOYSA-N Ethylene carbonate Chemical compound O=C1OCCO1 KMTRUDSVKNLOMY-UHFFFAOYSA-N 0.000 description 1
- 229910001200 Ferrotitanium Inorganic materials 0.000 description 1
- 206010017472 Fumbling Diseases 0.000 description 1
- 229910015015 LiAsF 6 Inorganic materials 0.000 description 1
- 229910013188 LiBOB Inorganic materials 0.000 description 1
- 229910013684 LiClO 4 Inorganic materials 0.000 description 1
- 101150058243 Lipf gene Proteins 0.000 description 1
- JLVVSXFLKOJNIY-UHFFFAOYSA-N Magnesium ion Chemical compound [Mg+2] JLVVSXFLKOJNIY-UHFFFAOYSA-N 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000006837 decompression Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000004880 explosion Methods 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 230000008595 infiltration Effects 0.000 description 1
- 238000001764 infiltration Methods 0.000 description 1
- 239000002198 insoluble material Substances 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 238000009830 intercalation Methods 0.000 description 1
- 230000002687 intercalation Effects 0.000 description 1
- 150000002506 iron compounds Chemical class 0.000 description 1
- 238000002955 isolation Methods 0.000 description 1
- 229910001425 magnesium ion Inorganic materials 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 238000005580 one pot reaction Methods 0.000 description 1
- 239000007800 oxidant agent Substances 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 238000013094 purity test Methods 0.000 description 1
- 238000004064 recycling Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 238000007086 side reaction Methods 0.000 description 1
- 238000004729 solvothermal method Methods 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 238000005979 thermal decomposition reaction Methods 0.000 description 1
- 231100000331 toxic Toxicity 0.000 description 1
- 230000002588 toxic effect Effects 0.000 description 1
- 230000005068 transpiration Effects 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B35/00—Boron; Compounds thereof
- C01B35/06—Boron halogen compounds
- C01B35/063—Tetrafluoboric acid; Salts thereof
- C01B35/066—Alkali metal tetrafluoborates
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/80—Compositional purity
-
- 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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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Secondary Cells (AREA)
Abstract
The invention discloses a preparation method of lithium tetrafluoroborate, belonging to the technical field of secondary battery electrolyte preparation; the preparation method specifically comprises the following steps: reacting the vapor of the fluorine source solution with solid lithium carbonate under oxygen-isolated, closed conditions; the solute of the fluorine source solution comprises at least one of boron trifluoride diethyl ether and boron trifluoride ethanol; the solvent of the fluorine source solution comprises at least one of diethyl ether, ethanol and carbonic ester solvents; the temperature of the reaction is 110-160 ℃. The preparation method provided by the invention can prepare high-purity lithium tetrafluoroborate by a simple and efficient method, can adopt preparation raw materials with lower purity, and does not need to carry out complex purification on the product.
Description
Technical Field
The invention relates to the technical field of preparation of secondary battery electrolyte, in particular to a preparation method of lithium tetrafluoroborate.
Background
The electrolyte is an important component of a lithium ion battery, and the main components of the electrolyte comprise a solvent and electrolyte salt. Currently, electrolyte salts used in lithium ion batteries are mainly LiClO 4 、LiPF 6 、LiAsF 6 、LiBOB、LiBF 4 Etc. Wherein, liPF 6 The electrolyte system has higher conductivity and can form stable SEI film, is an important electrolyte salt in the current lithium ion battery, but LiPF 6 Is sensitive to moisture and has poor thermal stability; liClO (LiClO) 4 Is a strong oxidant, is easy to cause explosion in use, and brings about a safety problem; liAsF 6 Although the performance is quite good, the materials are toxic and expensive, so the materials are not suitable for wide use; liBOB has better comprehensive performance and LiBF 4 The two electrolyte salts have good development prospects in the aspects of moisture, temperature sensitivity, safety performance and the like, but the research application of the two electrolyte salts is still in an initial stage, and a mass and high-quality production method is still in the fumbling process.
From the above analysis, it was found that lithium tetrafluoroborate (LiBF 4 ) As lithium ion electrolyte salt, the method has wider application prospect, but the existing preparation method of lithium tetrafluoroborate may have the defects of harsh preparation conditions, low purity of the obtained product or long flow and the like.
Disclosure of Invention
The present invention aims to solve at least one of the technical problems existing in the prior art. Therefore, the invention provides a preparation method of lithium tetrafluoroborate, which can prepare high-purity lithium tetrafluoroborate by a simple and efficient method, can adopt preparation raw materials with lower purity, and does not need to carry out complex purification on the product.
According to an embodiment of the first aspect of the present invention, there is provided a method for preparing lithium tetrafluoroborate, the method comprising:
reacting the vapor of the fluorine source solution with solid lithium carbonate under oxygen-isolated, closed conditions;
the solute of the fluorine source solution comprises at least one of boron trifluoride diethyl ether and boron trifluoride ethanol; the solvent of the fluorine source solution comprises at least one of diethyl ether, ethanol and carbonic ester solvents;
the temperature of the reaction is 110-160 ℃.
The reaction mechanism of the preparation method is as follows:
under the action of external heat environment, the boron trifluoride organic compound forms steam, and is condensed into a liquid film on the surface of solid lithium carbonate, and the boron trifluoride and the lithium carbonate in the liquid film react to generate carbon dioxide, boron tetrafluoride and boron oxide under the vapor pressure formed under the closed condition.
The preparation method provided by the embodiment of the invention has at least the following beneficial effects:
(1) Because the invention is not a strict solid-liquid reaction, the immersion and infiltration of liquid to solid are not needed, and therefore, the strict solid-liquid ratio is not needed to be limited in the preparation method. As long as the fluorine source solution is not burnt, no safety accident is caused. Therefore, the solid-liquid ratio can be enlarged, the consumption of liquid is reduced, and the amount of lithium tetrafluoroborate produced by a single reaction is increased, namely the yield is increased.
(2) Lithium tetrafluoroborate is typically produced by conventional methods of preparation and contains impurities, which are typically either from the reactants or by-products; the impurities in the lithium tetrafluoroborate can seriously affect the performance of the lithium tetrafluoroborate electrolyte, so that the traditional preparation method of the lithium tetrafluoroborate generally needs complicated impurity removal procedures.
In the preparation method provided by the invention, through the selection of the solvent, the lithium carbonate, impurities (iron-containing impurities and magnesium-containing impurities) in the lithium carbonate, and boron oxide and carbon dioxide generated by the reaction are insoluble in the solvent. Therefore, after the reaction is finished, lithium tetrafluoroborate with higher purity can be obtained by simple evaporation and crystallization.
Furthermore, the invention is the reaction of steam and lithium carbonate, so that the fluorine source solution which is not evaporated is not polluted and can be recycled, thereby achieving the purpose of saving the preparation raw materials.
(3) The invention limits the oxygen isolation condition and the reaction temperature, thereby ensuring the normal operation of the reaction process, promoting the rapid generation (improving the preparation efficiency) of the lithium tetrafluoroborate and ensuring the safety of the reaction process.
According to some embodiments of the invention, the lithium carbonate is suspended above the level of the fluorine source solution in the preparation method. Thereby, according to the upward transpiration of the steam, the lithium carbonate can be contacted with the lithium carbonate and react.
According to some embodiments of the invention, the means for suspending the lithium carbonate has a sloping surface, the lowest point of which sloping surface is connected to a liquid collector.
Thus, lithium tetrafluoroborate generated by the reaction can flow into the liquid collector along the slope surface along the liquid film formed by the steam. According to the analysis of the beneficial effect portion, it is known that only the solvent which flows back and lithium tetrafluoroborate generated by the reaction are included in the liquid collector, and therefore, lithium tetrafluoroborate with high purity can be obtained by simple evaporation and crystallization.
According to some embodiments of the invention, a filter membrane is provided at the connection location of the slope and the liquid collector. Therefore, even if the lithium carbonate slides downwards due to the action of gravity, the lithium carbonate cannot enter the liquid collector, and the purity of the lithium tetrafluoroborate obtained in the liquid collector is further ensured.
According to some embodiments of the invention, the temperature of the reaction is 115-130 ℃. This allows a better balance of cost, safety and efficiency.
According to some embodiments of the invention, the duration of the reaction is 1 to 6 hours. And a certain inverse relation is shown between the reaction time and the reaction temperature. A specific higher temperature brings about a higher pressure, which brings about a faster reaction rate.
According to some embodiments of the invention, the duration of the reaction is 1.5 to 3 hours.
According to some embodiments of the invention, the molar ratio of the solute of the fluorine source solution and the lithium carbonate is not less than 3.5.
The lithium carbonate is thus guaranteed to be fully reacted, but the above molar ratio is not specifically limited in practice, and the fluorine source is selected to be fully reacted.
According to some embodiments of the invention, the mass percentage of the solute in the fluorine source solution is 50-98%.
Therefore, the solvent vapor can drive the solute of the fluorine source solution to transpire, and the solvent vapor (or formed liquid film) provides a reaction matrix for the reaction of the solute of the fluorine source solution and lithium carbonate. And the solute concentration in the fluorine source solution is higher, so that the solid-to-liquid ratio of the preparation method can be improved, and the production efficiency of the preparation method is finally improved.
According to some embodiments of the invention, the method further comprises crystallizing the lithium tetrafluoroborate from the liquid in the liquid collector after the reaction is complete.
According to some embodiments of the invention, the crystallization method comprises evaporative crystallization;
the temperature of the evaporative crystallization is 120-130 ℃.
Furthermore, the evaporative crystallization further comprises condensing and collecting the evaporated solvent for recycling in the preparation method, thereby having the advantages of environmental protection and cost.
According to some embodiments of the invention, the method further comprises washing the solids on the slope with the solvent after the reaction is complete, and crystallizing the lithium tetrafluoroborate from the resulting wash solution.
According to some embodiments of the invention, the method of washing comprises rinsing with the solvent;
the flushing times are 2-3 times;
the mass of the solvent used for each flushing is 0.5 to 1 time of the mass of the lithium carbonate put in the preparation method.
According to some embodiments of the invention, the method of crystallization from the wash liquor comprises evaporative crystallization.
The temperature of the evaporative crystallization is 120-130 ℃.
The evaporating crystallization method also comprises reduced pressure evaporation, and the corresponding temperature after the pressure reduction can be calculated and converted according to the temperature of 120-130 ℃ under normal pressure.
The temperature of the evaporation crystallization selected by the invention is lower than the thermal decomposition temperature of the lithium tetrafluoroborate, but higher than the boiling point of the solvent and higher than the temperature of the water of the lithium tetrafluoroborate decrystallization. The lithium tetrafluoroborate can be separated from the solvent and water in a minimum time.
In boron tetrafluoride obtained by evaporative crystallization from the washing liquid, there may be some solid impurities which are difficult to separate and remove, for example impurities which are colloidal in solution. But still have a higher purity.
According to some embodiments of the invention, the reaction apparatus used in the preparation method comprises:
a cylinder having a sealing cap;
the support frame is fixed on the side wall of the cylinder body;
the slope surface is fixed by the supporting frame, and a gap is reserved between the slope surface and the side wall of the cylinder body;
a liquid collector detachably connected to the lowest point of the slope;
and the filter membrane is positioned at the connection position of the liquid collector and the slope surface.
The gap between the slope and the side wall ensures the vapor passage of the fluorine source solution. The design of the internal structure of the reaction instrument also has the function of guiding the moving direction of steam, and further has the function of improving the yield of lithium tetrafluoroborate.
According to some embodiments of the invention, the material of the reaction apparatus comprises at least one of polytetrafluoroethylene and titanium steel.
According to some embodiments of the invention, the slope surface is provided with a step-shaped grain, so that the substances on the slope surface can be prevented from sliding under the action of gravity to influence the purity of the substances in the liquid collector.
According to some embodiments of the invention, the method of preparation comprises the steps of:
s1, placing the fluorine source solution at the bottom of the cylinder; placing the lithium carbonate on the slope;
s2, heating the reaction instrument obtained in the step S1 to 110-160 ℃; and maintaining the reaction for 1 to 6 hours;
s3, collecting the liquid in the liquid collecting device obtained in the step S2, and evaporating and crystallizing to obtain the lithium tetrafluoroborate;
and (3) washing the solid on the slope surface obtained in the step (S2), and evaporating and crystallizing the obtained washing liquid to obtain the lithium tetrafluoroborate.
The term "about" as used herein, unless otherwise specified, means that the tolerance is within + -2%, for example, about 100 is actually 100 + -2%. Times.100.
Unless otherwise specified, the term "between … …" in the present invention includes the present number, for example "between 2 and 3" includes the end values of 2 and 3.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.
Drawings
The foregoing and/or additional aspects and advantages of the invention will become apparent and may be better understood from the following description of embodiments taken in conjunction with the accompanying drawings in which:
FIG. 1 is a schematic structural view of a reaction apparatus used in example 1 of the present invention.
Reference numerals:
a cylinder 100, a sealing cover 110,
A support frame 200;
a ramp 300;
a liquid collector 400, a filter membrane 410;
a fluorine source solution 500;
lithium carbonate 600.
Detailed Description
Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative only and are not to be construed as limiting the invention.
In the description of the present invention, the description of first, second, etc. is for the purpose of distinguishing between technical features only and should not be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated or implicitly indicating the precedence of the technical features indicated.
In the description of the present invention, it should be understood that the direction or positional relationship indicated with respect to the description of the orientation, such as up, down, etc., is based on the direction or positional relationship shown in the drawings, is merely for convenience of describing the present invention and simplifying the description, and does not indicate or imply that the apparatus or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention.
In the description of the present invention, unless explicitly defined otherwise, terms such as arrangement, installation, connection, etc. should be construed broadly and the specific meaning of the terms in the present invention can be determined reasonably by a person skilled in the art in combination with the specific content of the technical solution.
Example 1
The embodiment provides a preparation method of lithium tetrafluoroborate;
as shown in FIG. 1, the instrument adopted in the embodiment is made of polytetrafluoroethylene as a whole; the structure comprises the following steps:
a cylinder 100, the cylinder 100 having a sealing cap 110; the fluorine source solution is placed at the bottom of the cylinder 100;
the support frame 200, the support frame 200 is fixed on sidewall of the cylinder 100;
the slope surface 300, the slope surface 300 is fixed by the supporting frame 200, and a gap is reserved between the slope surface 300 and the side wall of the cylinder 100; the slope surface 300 is provided with step-shaped grains; lithium carbonate 600 is placed on the slope 300;
a liquid collector 400, the liquid collector 400 being detachably connected to the lowest point of the slope 300;
a filter membrane 410, the filter membrane 410 being located at the point where the liquid collector 400 and the ramp 300 are connected.
The preparation method provided by the embodiment comprises the following specific steps:
s1, placing 80ml of fluorine source solution and 10g of lithium carbonate according to the placement position shown in FIG. 1, and sealing a reaction instrument;
the lithium carbonate is analytically pure lithium carbonate with the purity of about 99.5 weight percent, wherein the impurities comprise magnesium ions and iron ions;
an ether solution of boron trifluoride diethyl etherate in a fluorine source solution, wherein the concentration of boron trifluoride diethyl etherate was 95%.
S2, heating the reaction system obtained in the step S1 to 125 ℃ (oil bath, wherein the liquid level of the oil bath covers the liquid level of the fluorine source solution without completely covering the whole reaction instrument), naturally cooling to room temperature after reacting for 2 hours, and starting the reaction instrument;
s3, taking out the materials in the liquid collecting device, and heating and evaporating the solvent to obtain lithium tetrafluoroborate 1;
the residual solids on the slope were rinsed twice with 10g of diethyl ether and the wash solution was further collected (taking care to exclude insoluble material, and filtration through a 0.22 μm filter) and evaporated to dryness to give lithium tetrafluoroborate 2.
The temperature of the heating and evaporating to dryness in the embodiment is 120-130 ℃ (without decompression).
Example 2
The present example provides a method for preparing lithium tetrafluoroborate, and the specific preparation steps are different from those of example 1 in that:
(1) In the step S1, the fluorine source solution is prepared by mixing boron trifluoride ethanol and ethylene carbonate according to a mass ratio of 1:1.
Comparative example 1
This comparative example provides a method for preparing lithium tetrafluoroborate, the preparation steps of this comparative example differ from those of example 2 in that:
the solid and the liquid in the same proportion as in example 2 were directly mixed and subjected to solvothermal reaction under the same conditions. I.e. a one-pot reaction without separating the solids from the liquids.
Comparative example 2
This comparative example provides a method for preparing lithium tetrafluoroborate, the preparation steps of this comparative example differ from those of example 2 in that:
(1) Replacing lithium carbonate with equimolar lithium sulfite with similar purity;
(2) The solid and liquid were directly mixed but reacted at normal temperature (about 25 ℃) for 12 hours.
Test case
This test example tests the purity of each part of the collected lithium tetrafluoroborate in each of examples 1 to 2 and comparative examples 1 to 2, and the yield of lithium tetrafluoroborate in each example; wherein:
the yield is based on the theoretical product quality of lithium tetrafluoroborate obtained by the complete reaction of lithium carbonate.
The purity test method comprises an atomic absorption method and a nuclear magnetic boron spectrum;
the test results are shown in Table 1.
TABLE 1 purity and yield of lithium tetrafluoroborate in examples 1 to 2 and comparative examples 1 to 2
Test results show that the preparation method provided by the embodiment can prepare lithium tetrafluoroborate with higher purity and obtain higher yield; although the purity of lithium tetrafluoroborate 2 is slightly lower than that of lithium tetrafluoroborate 1, it is also exceeding that of most of the existing preparation methods. If industrially desired, lithium tetrafluoroborate 2 may be further purified.
Furthermore, when the solvent in the fluorine source solution is relatively high and the amount of the lithium carbonate is relatively high, the steam generated by the solvent can attack impurities in the lithium carbonate more likely, so that the purity of the lithium tetrafluoroborate 2 can be reduced to a certain extent.
As is clear from comparative examples 2 and 1, the direct contact of boron trifluoride and lithium carbonate under high temperature and high pressure conditions promotes the intercalation of impurities in the raw materials for preparation into the product lithium tetrafluoroborate, which is difficult to separate. And the reactants are directly mixed and contacted, so that equilibrium is easily reached, and thus the yield is lowered.
As is clear from comparative examples 2 and 2, at low temperatures, although the side reactions were small and the impurity entering ratio was small, the yield of the product was significantly lowered under these conditions, and the economical efficiency was poor. Further, even if lithium carbonate was replaced with lithium sulfite which is considered to be advantageous for improving the yield in common knowledge, the yield of lithium tetrafluoroborate in comparative example 2 was not significantly improved.
The test example also tests the impurity content in the obtained lithium tetrafluoroborate, and the results show that the impurities in the lithium tetrafluoroborate obtained in examples 1-2 hardly contain water and volatile acid, which benefits from the closed environment provided by the reaction apparatus and the mutual coordination between the reaction temperature and the crystallization temperature. In further examples 1-2, the impurities of lithium tetrafluoroborate 1 were mainly non-volatile complete solvents, while lithium tetrafluoroborate 2 also contained trace amounts of lithium carbonate (not completely filtered), as well as impurities (e.g., magnesium and iron compounds) from the lithium carbonate raw material. However, in comparative example 2, since an open reaction system was used, about 50ppm of water impurities was contained in the obtained lithium tetrafluoroborate, which would bring about a safety hazard to the use of lithium tetrafluoroborate in an electrolyte.
The embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge of one of ordinary skill in the art without departing from the spirit of the present invention.
Claims (10)
1. A method for preparing lithium tetrafluoroborate, comprising:
reacting the vapor of the fluorine source solution with solid lithium carbonate under oxygen-isolated, closed conditions;
the solute of the fluorine source solution comprises at least one of boron trifluoride diethyl ether and boron trifluoride ethanol; the solvent of the fluorine source solution comprises at least one of diethyl ether, ethanol and carbonic ester solvents;
the temperature of the reaction is 110-160 ℃.
2. The method of claim 1, wherein the lithium carbonate is suspended above the level of the fluorine source solution.
3. The method of claim 2, wherein the means for suspending the lithium carbonate has a sloping surface, the lowest point of the sloping surface being connected to a liquid collector.
4. The method according to claim 3, further comprising crystallizing the lithium tetrafluoroborate from the liquid in the liquid collector after the reaction is completed.
5. A method according to claim 3, further comprising washing the solids on the slope with the solvent after the reaction is completed, and crystallizing the lithium tetrafluoroborate from the resulting washing solution.
6. The process according to any one of claims 1 to 5, wherein the temperature of the reaction is 115 to 130 ℃.
7. The process according to any one of claims 1 to 5, wherein the duration of the reaction is 1 to 6 hours.
8. The method according to claim 7, wherein the reaction time is 1.5 to 3 hours.
9. The method according to any one of claims 1 to 5, wherein the molar ratio of the solute of the fluorine source solution to the lithium carbonate is not less than 3.5.
10. The method according to any one of claims 1 to 5, wherein the mass percentage of the solute in the fluorine source solution is 50 to 98%.
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Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH11157830A (en) * | 1997-11-19 | 1999-06-15 | Central Glass Co Ltd | Production of lithium tetrafluoroborate |
| KR20000051923A (en) * | 1999-01-27 | 2000-08-16 | 박대치 | A Manufacturing Method for Lithium Tetrafluoroborate |
| JP2002293533A (en) * | 2001-03-30 | 2002-10-09 | Council Scient Ind Res | METHOD FOR PRODUCING LiBF4 |
| CN101863489A (en) * | 2010-06-11 | 2010-10-20 | 中国海洋石油总公司 | Method for preparing anhydrous high-purity lithium tetrafluoroborate |
| JP2011088807A (en) * | 2009-09-28 | 2011-05-06 | Nsc:Kk | Method for producing lithium borofluoride |
| WO2013018784A1 (en) * | 2011-08-03 | 2013-02-07 | セントラル硝子株式会社 | Method for producing lithium tetrafluoroborate solution |
| CN106082251A (en) * | 2016-06-12 | 2016-11-09 | 兰州理工大学 | A kind of preparation method of LiBF4 |
| EP3277694A1 (en) * | 2015-03-31 | 2018-02-07 | Bayerische Motoren Werke Aktiengesellschaft | Method of making lithium difluoro (oxalato) borate |
| CN108046233A (en) * | 2017-11-16 | 2018-05-18 | 常州弘正新能源股份有限公司 | A kind of preparation method of LiBF4 |
| CN109264736A (en) * | 2018-11-14 | 2019-01-25 | 东营石大胜华新能源有限公司 | A kind of preparation method of LiBF4 |
| CN113912075A (en) * | 2021-11-25 | 2022-01-11 | 山东中顼技术研究有限公司 | Preparation method of lithium tetrafluoroborate |
-
2022
- 2022-12-12 CN CN202211590560.8A patent/CN116102028B/en active Active
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH11157830A (en) * | 1997-11-19 | 1999-06-15 | Central Glass Co Ltd | Production of lithium tetrafluoroborate |
| KR20000051923A (en) * | 1999-01-27 | 2000-08-16 | 박대치 | A Manufacturing Method for Lithium Tetrafluoroborate |
| JP2002293533A (en) * | 2001-03-30 | 2002-10-09 | Council Scient Ind Res | METHOD FOR PRODUCING LiBF4 |
| JP2011088807A (en) * | 2009-09-28 | 2011-05-06 | Nsc:Kk | Method for producing lithium borofluoride |
| CN101863489A (en) * | 2010-06-11 | 2010-10-20 | 中国海洋石油总公司 | Method for preparing anhydrous high-purity lithium tetrafluoroborate |
| WO2013018784A1 (en) * | 2011-08-03 | 2013-02-07 | セントラル硝子株式会社 | Method for producing lithium tetrafluoroborate solution |
| EP3277694A1 (en) * | 2015-03-31 | 2018-02-07 | Bayerische Motoren Werke Aktiengesellschaft | Method of making lithium difluoro (oxalato) borate |
| CN106082251A (en) * | 2016-06-12 | 2016-11-09 | 兰州理工大学 | A kind of preparation method of LiBF4 |
| CN108046233A (en) * | 2017-11-16 | 2018-05-18 | 常州弘正新能源股份有限公司 | A kind of preparation method of LiBF4 |
| CN109264736A (en) * | 2018-11-14 | 2019-01-25 | 东营石大胜华新能源有限公司 | A kind of preparation method of LiBF4 |
| CN113912075A (en) * | 2021-11-25 | 2022-01-11 | 山东中顼技术研究有限公司 | Preparation method of lithium tetrafluoroborate |
Non-Patent Citations (2)
| Title |
|---|
| 溶液法制备四氟硼酸锂的研究;彭静红;郑典模;徐文赫;兰倩倩;;化工新型材料(第12期);全文 * |
| 锂离子电池用四氟硼酸锂的制备方法;王洁;宋海燕;;化工生产与技术(第01期);全文 * |
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