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EP-4741378-A1 - PREPARATION METHOD OF IONIC LIQUID

EP4741378A1EP 4741378 A1EP4741378 A1EP 4741378A1EP-4741378-A1

Abstract

A method of preparing an ionic liquid includes the following steps. A halogen-containing compound is reacted with a first compound to form a second compound. The halogen-containing compound includes a halohydrocarbon, a sulfonyl halide, or a combination thereof. The first compound includes an amine compound having a tertiary amine group, a phosphine compound, or a combination thereof. The second compound includes a first quaternary ammonium salt, a first quaternary phosphonium salt, or a combination thereof. The second compound and a lithium salt are reacted in a microwave device to form a third compound. The third compound includes a second quaternary ammonium salt, a second quaternary phosphonium salt, or a combination thereof. Anions of the second compound and the third compound are different. A microwave power of the microwave device is 700 watts to 1400 watts.

Inventors

  • CHEN, Wei-chao
  • CHEN, HSUAN-YU
  • WANG, PIN-HAN
  • Chang, Tseng-Lung

Assignees

  • Hon Hai Precision Industry Co., Ltd.
  • SolidEdge Solution Inc.

Dates

Publication Date
20260513
Application Date
20250917

Claims (15)

  1. A method of preparing an ionic liquid, characterized by comprising: reacting a halogen-containing compound with a first compound to form a second compound, wherein the halogen-containing compound comprises a halohydrocarbon, a sulfonyl halide, or a combination thereof, the first compound comprises an amine compound having a tertiary amine group, a phosphine compound, or a combination thereof, and the second compound comprises a first quaternary ammonium salt, a first quaternary phosphonium salt, or a combination thereof; and reacting the second compound with a lithium salt in a microwave device to form a third compound, wherein the third compound comprises a second quaternary ammonium salt, a second quaternary phosphonium salt, or a combination thereof, anions of the second compound and the third compound are different, and a microwave power of the microwave device is 700 watts to 1400 watts.
  2. The method of preparing the ionic liquid of claim 1, characterized in that the amine compound having the tertiary amine group comprises a structure as shown in formula (1-1), an imidazole compound, a pyrrolidine compound, a pyridine compound, a pyrrole compound, a pyrazole compound, a structure as shown in formula (1-2), an imidazoline compound, a pyrazoline compound, or combinations thereof, wherein R 1 to R 5 are independently a C1 to C22 linear alkyl group, a C1 to C22 branched alkyl group, a C4 to C6 cycloalkyl group, or a C4 to C6 heterocycloalkyl group.
  3. The method of preparing the ionic liquid of claim 2, characterized in that the imidazole compound has a structure as shown in formula (1-3), wherein R 6 to R 9 are independently hydrogen, a C1 to C22 linear alkyl group, a C1 to C22 branched alkyl group, a C4 to C6 cycloalkyl group, or a C4 to C6 heterocycloalkyl group.
  4. The method of preparing the ionic liquid of claims 2 or 3, characterized in that the pyrrolidine compound has a structure as shown in formula (1-4), wherein R 10 is a C1 to C22 linear alkyl group, a C1 to C22 branched alkyl group, a C4 to C6 cycloalkyl group, or a C4 to C6 heterocycloalkyl group, and R 11 to R 14 are independently hydrogen, a C1 to C22 linear alkyl group, a C1 to C22 branched alkyl group, a C4 to C6 cycloalkyl group, or a C4 to C6 heterocycloalkyl group.
  5. The method of preparing the ionic liquid of any one of claims 1 to 4, characterized in that the halohydrocarbon has a structure as shown in formula (2-1), and the sulfonyl halide has a structure as shown in formula (2-2), R 1 '-X 1 formula (2-1), R 2 '-SO 2 X 2 formula (2-2), wherein R 1 ' and R 2 ' are independently a C1 to C22 linear alkyl group, a C1 to C22 branched alkyl group, a C4 to C6 cycloalkyl group, a C4 to C6 heterocycloalkyl group, or a C6 to C10 aryl group, and X 1 and X 2 are independently fluorine, chlorine, bromine, or iodine.
  6. The method of preparing the ionic liquid of any one of claims 1 to 5, characterized in that a reaction pressure of reacting the second compound with the lithium salt in the microwave device is greater than 1 atm and less than or equal to 2 atm.
  7. The method of preparing the ionic liquid of any one of claims 1 to 6, characterized by further comprising: after reacting the second compound with the lithium salt in the microwave device, performing a heating operation, wherein a heating temperature of the heating operation is 60 °C to 180 °C.
  8. The method of preparing the ionic liquid of claim 7, characterized in that a heating time of the heating operation is less than or equal to 6 hours.
  9. The method of preparing the ionic liquid of any one of claims 1 to 8, characterized in that a reaction temperature of reacting the halogen-containing compound with the first compound is 25 °C to 100 °C.
  10. A method of preparing an ionic liquid, characterized by comprising: reacting a halogen-containing compound with a first compound in a first microwave device to form a second compound, wherein the halogen-containing compound comprises a halohydrocarbon, a sulfonyl halide, or a combination thereof, the first compound comprises an amine compound having a tertiary amine group, a phosphine compound, or a combination thereof, the second compound comprises a first quaternary ammonium salt, a first quaternary phosphonium salt, or a combination thereof, and the amine compound having the tertiary amine group comprises a structure as shown in formula (1-1), an imidazole compound, a pyrrolidine compound, a pyridine compound, a pyrrole compound, a pyrazole compound, a structure as shown in formula (1-2), an imidazoline compound, a pyrazoline compound, or combinations thereof, wherein R 1 to R 5 are independently a C1 to C22 linear alkyl group, a C1 to C22 branched alkyl group, a C4 to C6 cycloalkyl group, or a C4 to C6 heterocycloalkyl group; and reacting the second compound with a lithium salt in a second microwave device to form a third compound, wherein the third compound comprises a second quaternary ammonium salt, a second quaternary phosphonium salt, or a combination thereof, and anions of the second compound and the third compound are different.
  11. The method of preparing the ionic liquid of claim 10, characterized in that a microwave power of reacting the halogen-containing compound with the first compound in the first microwave device and a microwave power of reacting the second compound with the lithium salt reacted in the second microwave device are respectively 700 watts to 1400 watts.
  12. The method of preparing the ionic liquid of any one of claims 10 to 11, characterized in that a reaction pressure of reacting the halogen-containing compound with the first compound in the first microwave device and a reaction pressure of reacting the second compound with the lithium salt in the second microwave device are respectively greater than 1 atm and less than or equal to 2 atm.
  13. The method of preparing the ionic liquid of any one of claims 10 to 12, characterized in that a reaction temperature of reacting the halogen-containing compound with the first compound in the first microwave device and a reaction temperature of reacting the second compound with the lithium salt in the second microwave device are respectively 60 °C to 250 °C.
  14. The method of preparing the ionic liquid of any one of claims 10 to 13, characterized in that the anion of the second compound is a halide ion or a structure as shown in formula (4-1), the anion of the third compound is bis(trifluoromethanesulfonyl)imide anion, bis(fluorosulfonyl)imide anion, tetrafluoroborate anion, hexafluorophosphate anion, trifluoromethanesulfonate anion, acetate ion, a structure as shown in formula (4-2), a structure as shown in formula (4-3), a structure as shown in formula (4-4), or combinations thereof, wherein X 3 is fluorine, chlorine, bromine, or iodine, and R 1 ", R 2 ", and R 3 " are independently a C1 to C22 linear alkyl group, a C1 to C22 branched alkyl group, a C4 to C6 cycloalkyl group, or a C4 to C6 heterocycloalkyl group.
  15. The method of preparing the ionic liquid of any one of claims 10 to 14, characterized in that a molar ratio of the halogen-containing compound to the first compound is 1:1 to 2:1, and a molar ratio of the second compound to the lithium salt is 1:1 to 1:2.

Description

BACKGROUND Field of Disclosure The present disclosure relates to a method of preparing an ionic compound. Description of Related Art An electrolyte is indispensable in batteries. Traditionally, liquid electrolytes are often used as electrolytes in the batteries, in which the liquid electrolytes such as ethylene carbonate, diethyl carbonate, methyl ethyl carbonate, and so on have low ignition point and volatility point. Therefore, when the battery thermally runs out of control, it can easily trigger safety concerns. Since the liquid electrolytes have the above problems, other types of electrolytes or electrolyte auxiliary agents are gradually developed, such as solid electrolytes, special additives, gelled electrolytes, or flame retardants. The solid electrolytes have complex interface and ionic conductivity issues, so they are not widely used. Although the special additives such as fluoroethylene carbonate, difluoroethylene carbonate, and 2,2,2-trifluoroethylmethyl carbonate have high ignition and boiling points, the special additives are expensive and difficult to be produced. Therefore, the special additives are not widely used. Due to the introduction of gelled substances, the gelled electrolytes are less likely to produce a large number of reaction interfaces, and boiling issue still exists. The flame retardants have problems such as increased battery internal resistance and poor reaction uniformity after the flame retardants introducing into the battery, so they cannot be widely used. Therefore, there is an urgent need to develop other electrolytes that can improve flame resistance, battery stability, and ionic conductivity. SUMMARY The present disclosure provides a method of preparing an ionic liquid, and the method includes the following steps. A halogen-containing compound is reacted with a first compound to form a second compound, in which the halogen-containing compound includes a halohydrocarbon, a sulfonyl halide, or a combination thereof, the first compound includes an amine compound having a tertiary amine group, a phosphine compound, or a combination thereof, and the second compound includes a first quaternary ammonium salt, a first quaternary phosphonium salt, or a combination thereof. The second compound is reacted with a lithium salt in a microwave device to form a third compound, in which the third compound includes a second quaternary ammonium salt, a second quaternary phosphonium salt, or a combination thereof, anions of the second compound and the third compound are different, and a microwave power of the microwave device is 700 watts to 1400 watts. In some embodiments, the amine compound having the tertiary amine group includes a structure as shown in formula (1-1), an imidazole compound, a pyrrolidine compound, a pyridine compound, a pyrrole compound, a pyrazole compound, a structure as shown in formula (1-2), an imidazoline compound, a pyrazoline compound, or combinations thereof, formula (1-1), in which R1 to R5 are independently a C1 to C22 linear alkyl group, a C1 to C22 branched alkyl group, a C4 to C6 cycloalkyl group, or a C4 to C6 heterocycloalkyl group. In some embodiments, the imidazole compound has a structure as shown in formula (1-3), in which R6 to R9 are independently hydrogen, a C1 to C22 linear alkyl group, a C1 to C22 branched alkyl group, a C4 to C6 cycloalkyl group, or a C4 to C6 heterocycloalkyl group. In some embodiments, the pyrrolidine compound has a structure as shown in formula (1-4), in which R10 is a C1 to C22 linear alkyl group, a C1 to C22 branched alkyl group, a C4 to C6 cycloalkyl group, or a C4 to C6 heterocycloalkyl group, and R11 to R14 are independently hydrogen, a C1 to C22 linear alkyl group, a C1 to C22 branched alkyl group, a C4 to C6 cycloalkyl group, or a C4 to C6 heterocycloalkyl group. In some embodiments, the halohydrocarbon has a structure as shown in formula (2-1), and the sulfonyl halide has a structure as shown in formula (2-2),         R1'-X1     formula (2-1),         R2'-SO2X2     formula (2-2), in which R1' and R2' are independently a C1 to C22 linear alkyl group, a C1 to C22 branched alkyl group, a C4 to C6 cycloalkyl group, a C4 to C6 heterocycloalkyl group, or a C6 to C10 aryl group, and X1 and X2 are independently fluorine, chlorine, bromine, or iodine. In some embodiments, a reaction pressure of reacting the second compound with the lithium salt in the microwave device is greater than 1 atm and less than or equal to 2 atm. In some embodiments, a reaction temperature of reacting the second compound with the lithium salt in the microwave device is 60 °C to 250 °C. In some embodiments, the lithium salt includes lithium bis(trifluoromethanesulfonyl)imide, lithium bis(fluorosulfonyl)imide, lithium tetrafluoroborate, lithium hexafluorophosphate, lithium trifluoromethanesulfonate, lithium acetate, a structure as shown in formula (3-1), a structure as shown in formula (3-2), a structure as shown in formula (3-3), or combination