A tolanyl monomer liquid crystal for ionic battery electrolyte and its preparation method

Abstract

The invention discloses a tolan monomer liquid crystal for ionic battery electrolyte and a preparation method thereof. The preparation method comprises first preparing an intermediate containing tolan and a polyether structure by a Sonogashira coupling reaction, and then introducing a ethylene carbonate group by a further reaction. This type of monomer liquid crystal is used for ionic battery electrolytes, and can overcome the shortcomings of easy leakage of traditional liquid electrolytes and low transmission rate of solid electrolytes, and combines their advantages; at the same time, the molecular structure contains ethylene carbonate and polyether structures, which can effectively transmit alkali metal ions such as lithium and sodium; and the tolan groups contained in the structure have a high electron cloud density, which can form a π electron stacking effect between molecules, forming a more regular structure, thereby improving the ion transmission efficiency of the electrolyte.

Description

Technical Field

[0001] The invention relates to the field of ionic battery electrolytes, and in particular to a tolan monomer liquid crystal for ionic battery electrolytes and a preparation method thereof. Background Art

[0002] Traditional liquid electrolytes have high ionic conductivity and a wide temperature range, but they are prone to leakage and flammability, making the development of new electrolytes imperative. However, for inorganic solid electrolyte lithium-ion batteries, key challenges still exist, such as electrode volume changes, interfacial charge transfer resistance, flexibility, and poor cycle stability. Organic polymer solid electrolytes overcome these limitations of inorganic solid electrolytes, have good flexibility and can be in close contact with electrodes, but their small electrochemical stability window and poor ion transfer rate (room temperature) are also the reasons that currently hinder their development. Summary of the invention

[0003] In order to solve the above problems, the present invention aims to provide a diphenylacetylene monomer liquid crystal for ionic battery electrolyte and a preparation method thereof, which has good safety, high energy density, and long-term static and dynamic stability.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is:

[0005] A tolanyl monomer liquid crystal for ionic battery electrolyte, the structural formula is:

[0006]

[0007] Where: R is C1-C 12 Straight chain saturated alkyl or C1-C 12 One of the straight chain saturated ester groups; n is an integer between 2 and 5; m is the molecular weight range of polyvinyl alcohol, and the value is 100-1000.

[0008] A method for preparing a tolanyl monomer liquid crystal for an ionic battery electrolyte. The synthesis route of the tolanyl monomer liquid crystal for an ionic battery electrolyte is:

[0009]

[0010] Where: R is C1-C 12 Straight chain saturated alkyl or C1-C 12 One of the straight chain saturated ester groups; n is an integer between 2 and 5; m is the molecular weight range of polyvinyl alcohol, and the value is 100-1000.

[0011] Furthermore, the preparation method of the tolan monomer liquid crystal for ionic battery electrolyte comprises the following steps:

[0012] The first step is to dissolve 0.1 mol of raw material A in a mixed solvent of 100 mL of tetrahydrofuran (THF) and 100 mL of triethylamine (TEA), place the mixture in a reactor and pass it through an inert gas protection, then add 0.1-0.2 mol of raw material R-phenylacetylene, control the reaction temperature at 60-100° C., add 0.1-0.3 g of bistriphenylphosphine palladium dichloride (Pdcl2(PPh3)2) and 0.2-0.6 g of cuprous iodide (CuI) as catalysts, and react for 15-20 hours under the protection of inert gas; after stopping the reaction, remove by reduced pressure distillation to obtain compound B;

[0013] The second step is to dissolve 0.05 mol of compound B and 0.07 mol of triphenylphosphine (PPh3) in 50 mL of THF solution, stir and cool to -1-10°C, add 0.06-0.10 mol of compound C, slowly add 0.07 mol of diethyl azodicarboxylate (DEAD) under stirring, slowly warm to room temperature and continue to react for 10-15 hours; then evaporate the reaction solvent THF under reduced pressure, add 50 mL of cyclohexane to the residual system, and filter out insoluble triphenylphosphine; evaporate the cyclohexane again under reduced pressure, add 50 mL of 95% ethanol, stir and dissolve, add 0.06-0.10 mol of p-toluenesulfonic acid monohydrate, react at room temperature for 3 hours, and after the reaction is completed, evaporate the reaction solvent to obtain compound D;

[0014] The third step is to dissolve 0.01 mol of compound D, 1-3 g of KF and 1-3 g of Al2O3 in 40 mL of diethyl carbonate, heat to 120-160°C and react for 4-8 hours. After the reaction is completed, add 500 mL of CHCl3 to dilute the reactant, filter out the insoluble KF and Al2O3, and then distill under reduced pressure to remove the solvent CHCl3 to obtain a crude product. The crude product is purified by column chromatography to obtain the target product E.

[0015] Furthermore, in the third step of column chromatography purification, the volume ratio of the eluent used to cyclohexane / CHCl3 is 1:1.

[0016] The present invention has the following advantages:

[0017] The phenylacetylene monomer liquid crystal for ionic battery electrolyte of the present invention introduces polyether and ethylene carbonate structures into the monomer liquid crystal molecular structure, and can form an effective battery ion transmission channel through the self-assembly of the liquid crystal material. The phenylacetylene group is introduced into the monomer liquid crystal molecular structure involved, and due to the stacking effect of π electrons, the orderly arrangement between the liquid crystal molecules is increased, so that the aggregation state of the liquid crystal molecules is more inclined to a single domain, which helps to form a more regular arrangement of the ion channel, thereby generating more effective ion transmission.

[0018] The invention discloses a method for preparing a diphenylacetylene monomer liquid crystal for an ion-type battery electrolyte. An intermediate containing diphenylacetylene and a polyether structure is prepared by a Sonogashira coupling reaction, and then a ethylene carbonate group is introduced by a further reaction. This type of monomer liquid crystal is used for an ion battery electrolyte, and can overcome the shortcomings of easy leakage of a traditional liquid electrolyte and low transmission rate of a solid electrolyte, and combines their advantages. At the same time, the molecular structure contains ethylene carbonate and a polyether structure, and these structures can effectively transmit alkali metal ions such as lithium and sodium. Moreover, the diphenylacetylene group contained in the structure has a high electron cloud density, and can form a π electron stacking effect between molecules to form a more regular structure, thereby improving the ion transmission efficiency of the electrolyte.

[0019] Liquid crystal state is the intermediate phase between liquid and solid. Using liquid crystal, an ordered fluid, as electrolyte can effectively avoid the drawbacks of traditional liquid electrolytes and solid electrolytes. Achieving the necessary parameters of liquid crystal electrolytes, meeting the chemical reactions of new batteries, and providing good safety, high energy density, long-term static and dynamic stability, and long cycle life will completely change the field of rechargeable batteries in the future. DETAILED DESCRIPTION

[0020] In order to facilitate the understanding of the present invention, the present invention will be described in detail below, and individual implementation cases of the present invention will be given.

[0021] The present invention provides a synthesis route of a tolanyl monomer liquid crystal for an ionic battery electrolyte:

[0022]

[0023] Where: R is C1-C 12 Straight chain saturated alkyl or C1-C 12 One of the straight chain saturated ester groups; n is an integer between 2 and 5; m is the molecular weight range of polyvinyl alcohol, and the value is 100-1000.

[0024] Example 1

[0025] A method for preparing a tolanyl monomer liquid crystal for an ionic battery electrolyte comprises the following steps:

[0026] In the first step, 0.1 mol of raw material A is dissolved in a mixed solvent of 100 mL of tetrahydrofuran (THF) and 100 mL of triethylamine (TEA), placed in a reactor and protected by an inert gas, then 0.1 mol of raw material R-phenylacetylene is added, the reaction temperature is controlled at 80°C, 0.3 g of bistriphenylphosphine palladium dichloride (Pdcl2(PPh3)2) and 0.4 g of cuprous iodide (CuI) are added as catalysts, and the reaction is carried out under inert gas protection for 20 hours. After stopping the reaction, the compound B is obtained by distillation under reduced pressure.

[0027] In the second step, 0.05mol of compound B and 0.07mol of triphenylphosphine (PPh3) were dissolved in 50mL of THF solution, stirred and cooled to 5°C, 0.10mol of compound C was added, 0.07mol of diethyl azodicarboxylate (DEAD) was slowly added under stirring, and the reaction was continued for 12h after slowly warming to room temperature. Then, the reaction solvent THF was evaporated under reduced pressure, 50mL of cyclohexane was added to the residual system, and insoluble triphenylphosphine was removed by filtration. Cyclohexane was evaporated under reduced pressure again, 50mL of 95% ethanol was added, and after stirring and dissolving, 0.10mol of p-toluenesulfonic acid monohydrate was added, and the reaction was carried out at room temperature for 3h. After the reaction was completed, the reaction solvent was evaporated to obtain compound D.

[0028] In the third step, 0.01 mol of compound D, 1 g of KF and 2 g of Al2O3 were dissolved in 40 mL of diethyl carbonate, and the temperature was raised to 160°C for 4 h. After the reaction was completed, 500 mL of CHCl3 was added to dilute the reactant, and after filtering to remove the insoluble KF and Al2O3, the solvent CHCl3 was removed by vacuum distillation to obtain a crude product. The crude product was purified by column chromatography (eluent: cyclohexane / CHCl3=1:1) to obtain the target product E.

[0029] Example 2

[0030] A method for preparing a tolanyl monomer liquid crystal for an ionic battery electrolyte comprises the following steps:

[0031] In the first step, 0.1 mol of raw material A is dissolved in a mixed solvent of 100 mL of tetrahydrofuran (THF) and 100 mL of triethylamine (TEA), placed in a reactor and protected by an inert gas, then 0.2 mol of raw material R-phenylacetylene is added, the reaction temperature is controlled at 100°C, 0.2 g of bistriphenylphosphine palladium dichloride (Pdcl2(PPh3)2) and 0.2 g of cuprous iodide (CuI) are added as catalysts, and the reaction is carried out under inert gas protection for 15 hours. After stopping the reaction, the compound B is obtained by distillation under reduced pressure.

[0032] In the second step, 0.05mol of compound B and 0.07mol of triphenylphosphine (PPh3) were dissolved in 50mL of THF solution, stirred and cooled to 10°C, 0.06mol of compound C was added, 0.07mol of diethyl azodicarboxylate (DEAD) was slowly added under stirring, and the reaction was continued for 10h after slowly warming to room temperature. Then, the reaction solvent THF was evaporated under reduced pressure, 50mL of cyclohexane was added to the residual system, and the insoluble triphenylphosphine was filtered out. The cyclohexane was evaporated under reduced pressure again, 50mL of 95% ethanol was added, and after stirring and dissolving, 0.08mol of p-toluenesulfonic acid monohydrate was added, and the reaction was carried out at room temperature for 3h. After the reaction was completed, the reaction solvent was evaporated to obtain compound D.

[0033] In the third step, 0.01 mol of compound D, 3 g of KF and 1 g of Al2O3 were dissolved in 40 mL of diethyl carbonate, and the temperature was raised to 120°C for reaction for 8 h. After the reaction was completed, 500 mL of CHCl3 was added to dilute the reactant, and after filtering to remove the insoluble KF and Al2O3, the solvent CHCl3 was removed by vacuum distillation to obtain a crude product. The crude product was purified by column chromatography (eluent: cyclohexane / CHCl3=1:1) to obtain the target product E.

[0034] Example 3

[0035] A method for preparing a tolanyl monomer liquid crystal for an ionic battery electrolyte comprises the following steps:

[0036] In the first step, 0.1 mol of raw material A is dissolved in a mixed solvent of 100 mL of tetrahydrofuran (THF) and 100 mL of triethylamine (TEA), placed in a reactor and protected by an inert gas, then 0.15 mol of raw material R-phenylacetylene is added, the reaction temperature is controlled at 60°C, 0.1 g of bistriphenylphosphine palladium dichloride (Pdcl2(PPh3)2) and 0.6 g of cuprous iodide (CuI) are added as catalysts, and the reaction is carried out under inert gas protection for 18 hours. After stopping the reaction, the compound B is obtained by distillation under reduced pressure.

[0037] In the second step, 0.05mol of compound B and 0.07mol of triphenylphosphine (PPh3) were dissolved in 50mL of THF solution, stirred and cooled to -1°C, 0.08mol of compound C was added, 0.07mol of diethyl azodicarboxylate (DEAD) was slowly added under stirring, and the reaction was continued for 15h after slowly warming to room temperature. Then, the reaction solvent THF was evaporated under reduced pressure, 50mL of cyclohexane was added to the residual system, and the insoluble triphenylphosphine was filtered out. The cyclohexane was evaporated under reduced pressure again, 50mL of 95% ethanol was added, and after stirring and dissolving, 0.06mol of p-toluenesulfonic acid monohydrate was added, and the reaction was carried out at room temperature for 3h. After the reaction was completed, the reaction solvent was evaporated to obtain compound D.

[0038] In the third step, 0.01 mol of compound D, 1.5 g of KF and 3 g of Al2O3 were dissolved in 40 mL of diethyl carbonate, and the temperature was raised to 130°C for reaction for 5 h. After the reaction was completed, 500 mL of CHCl3 was added to dilute the reactant, and after filtering to remove the insoluble KF and Al2O3, the solvent CHCl3 was removed by vacuum distillation to obtain a crude product. The crude product was purified by column chromatography (eluent: cyclohexane / CHCl3=1:1) to obtain the target product E.

Claims

1. A tolanyl monomer liquid crystal for ionic battery electrolyte, characterized in that Its structural formula is: Where: R is C1-C 12 Straight chain saturated alkyl or C1-C 12 One of the linear saturated ester groups; n is an integer between 2 and 5; m is the molecular weight range of polyvinyl alcohol, and the value is 100-1000; the synthesis route is: Where: R is C1-C 12 Straight chain saturated alkyl or C1-C 12 One of the straight chain saturated ester groups; n is an integer between 2 and 5; m is the molecular weight range of polyvinyl alcohol, and the value is 100-1000.

2. The method for preparing the tolanyl monomer liquid crystal for ionic battery electrolyte according to claim 1, characterized in that The following steps are involved: The first step is to dissolve 0.1 mol of raw material A in a mixed solvent of 100 mL of tetrahydrofuran (THF) and 100 mL of triethylamine (TEA), place the mixture in a reactor and pass it through an inert gas protection, then add 0.1-0.2 mol of raw material R-phenylacetylene, control the reaction temperature at 60-100° C., add 0.1-0.3 g of bistriphenylphosphine palladium dichloride (Pdcl2(PPh3)2) and 0.2-0.6 g of cuprous iodide (CuI) as catalysts, and react for 15-20 hours under the protection of inert gas; after stopping the reaction, remove by reduced pressure distillation to obtain compound B; The second step is to dissolve 0.05 mol of compound B and 0.07 mol of triphenylphosphine (PPh3) in 50 mL of THF solution, stir and cool to -1-10°C, add 0.06-0.10 mol of compound C, slowly add 0.07 mol of diethyl azodicarboxylate (DEAD) under stirring, slowly warm to room temperature and continue to react for 10-15 hours; then evaporate the reaction solvent THF under reduced pressure, add 50 mL of cyclohexane to the residual system, and filter out insoluble triphenylphosphine; evaporate the cyclohexane again under reduced pressure, add 50 mL of 95% ethanol, stir and dissolve, add 0.06-0.10 mol of p-toluenesulfonic acid monohydrate, react at room temperature for 3 hours, and after the reaction is completed, evaporate the reaction solvent to obtain compound D; The third step is to dissolve 0.01 mol of compound D, 1-3 g of KF and 1-3 g of Al2O3 in 40 mL of diethyl carbonate, heat to 120-160°C and react for 4-8 hours. After the reaction is completed, add 500 mL of CHCl3 to dilute the reactant, filter out the insoluble KF and Al2O3, and then distill under reduced pressure to remove the solvent CHCl3 to obtain a crude product. The crude product is purified by column chromatography to obtain the target product E.

3. The method for preparing the tolanyl monomer liquid crystal for ionic battery electrolyte according to claim 2, characterized in that: In the third step of column chromatography purification, the volume ratio of the eluent to cyclohexane / CHCl3 is 1:1.

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