CN113363011B - Solvent-free polymer ion conductor and preparation method and application thereof - Google Patents

Abstract

The invention relates to the field of functional polymer materials, and discloses a solvent-free polymer ion conductor and a preparation method and application thereof. The preparation method comprises the steps of firstly contacting a compound containing amino or hydrazide, an aldehyde compound and organic metal lithium salt in an organic solvent to perform reversible Schiff base reaction to obtain gel, and then drying the gel to obtain the solvent-free polymer ion conductor. The solvent-free polymer ionic conductor prepared by the method has the advantage of high room-temperature ionic conductivity.

Description

Solvent-free polymer ionic conductor and preparation method and application thereof

technical field

The invention relates to the field of functional polymer materials, in particular to a solvent-free polymer ion conductor and a preparation method and application thereof.

Background technique

Polymer ion conductors have the advantages of good film formation, light weight, good flexibility, and high stability, and can be endowed with various functions such as stretchability, self-healing, transparency, and shape memory through flexible and diverse molecular chain designs. It shows good application prospects and has attracted widespread attention.

Polymer ionic conductors can generally be divided into two categories: polymer gels and solvent-free polymer ionic conductors. The liquid in the polymer gel will undergo a phase transition and solidify at low temperature, and the solvent in the gel will volatilize under room/high temperature conditions, resulting in a sharp decrease in the stretchability and ionic conductivity of the gel, so it is thermally stable. The performance and environmental adaptability are very poor, and it is still difficult to achieve practical application transformation.

Heteroatoms (O, S, Si, N, etc.) containing lone pairs of electrons on the molecular chain of solvent-free polymer ionic conductors are complexed with metal salt ions (Li ⁺ , etc.), and with the movement of polymer molecular segments, metal The lone pair electrons on the ions and heteroatoms are continuously complexed and dissociated through coordination, which can realize the migration of metal ions along the polymer molecular chains and between chains. Although solvent-free polymer ion conductors can achieve practical application transformation compared with polymer gels, the current biggest bottleneck of solvent-free polymer ion conductors is their low room temperature ionic conductivity.

Therefore, there is an urgent need to provide a solvent-free polymer ionic conductor with high ionic conductivity at room temperature and a preparation method thereof.

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome the problem of low room temperature ionic conductivity of solvent-free polymer ion conductors in the prior art, and to provide a solvent-free polymer ion conductor and a preparation method and application thereof. The solvent-free polymer ion conductor has The advantage of high ionic conductivity at room temperature.

In order to achieve the above object, a first aspect of the present invention provides a method for preparing a solvent-free polymer ion conductor, the method comprising: firstly dissolving an amino group- or hydrazide-containing compound, an aldehyde compound, and an organometallic lithium salt in an organic solvent contact in the middle, a reversible Schiff base reaction occurs to obtain a gel, and then the gel is dried to obtain a solvent-free polymer ion conductor;

Wherein, at least one of the amino- or hydrazide-containing compound and the aldehyde compound is a polymer;

The amino group-containing compound is selected from at least one of polyoxyethylene diamine, polydimethylsiloxane diamine, trimesiamine, and p-phenylenediamine, and the hydrazide-containing compound is selected from biparat Benzohydrazide-terminated polyoxyethylene and/or N,N,N,N-tetrapropionylhydrazide-terminated polydimethylsiloxane;

The aldehyde compound is selected from trimesaldehyde, terephthalaldehyde, 2,2,2-trisubstituted p-benzaldehyde methyl ether ethane, aldehyde group-terminated polyoxyethylene, aldehyde group-terminated polydimethylsilicon at least one of oxanes;

The organic metal lithium salt is selected from at least one of lithium bistrifluoromethanesulfonimide, lithium perchlorate, lithium hexafluorophosphate, lithium tetrafluoroborate, lithium hexafluoroarsenate, and lithium trifluoromethanesulfonate.

The second aspect of the present invention provides a solvent-free polymer ion conductor prepared by the preparation method described in the second aspect of the present invention; preferably, the ionic conductivity of the solvent-free polymer ion conductor at room temperature is 0.3×10 ^{− 4} S/cm to 5×10 ^-4 S/cm, preferably 0.4×10 ^-4 S/cm to 3×10 ^-4 S/cm.

A third aspect of the present invention provides the application of a solvent-free polymer ion conductor in a battery.

Through above-mentioned technical scheme, the beneficial technical effect that the present invention obtains is as follows:

1) The solvent-free polymer ionic conductor provided by the present invention has the advantage of high ionic conductivity at room temperature;

2) The preparation method of the solvent-free polymer ion conductor provided by the present invention is simple to operate and suitable for industrialization;

3) The solvent-free polymer ion conductor provided by the present invention has a good application prospect in the battery field.

Description of drawings

Fig. 1 is the infrared image of the solvent-free polymer ion conductor prepared in Example 1;

Fig. 2 is the infrared image of the solvent-free polymer ion conductor prepared by embodiment 2;

Fig. 3 is the thermogravimetric curve diagram of the solvent-free polymer ion conductor prepared in Example 1;

Fig. 4 is the ionic conductivity test result diagram of the solvent-free polymer ionic conductor prepared in Example 1;

Fig. 5a is a graph showing the test results of the mechanical properties of the solvent-free polymer ion conductor prepared in Example 1;

FIG. 5b is a graph showing the test results of the electrical properties of the solvent-free polymer ionic conductor prepared in Example 1. FIG.

Detailed ways

The endpoints of ranges and any values disclosed herein are not limited to the precise ranges or values, which are to be understood to encompass values proximate to those ranges or values. For ranges of values, the endpoints of each range, the endpoints of each range and the individual point values, and the individual point values can be combined with each other to yield one or more new ranges of values that Ranges should be considered as specifically disclosed herein.

A first aspect of the present invention provides a method for preparing a solvent-free polymer ion conductor, the method comprising: firstly contacting an amino- or hydrazide-containing compound, an aldehyde compound, and an organometallic lithium salt in an organic solvent, and a reversible reaction occurs. The Schiff base is reacted to obtain a gel, and then the gel is dried to obtain a solvent-free polymer ion conductor;

Wherein, at least one of the amino- or hydrazide-containing compound and the aldehyde compound is a polymer;

The amino group-containing compound is selected from at least one of polyoxyethylene diamine, polydimethylsiloxane diamine, trimesiamine, and p-phenylenediamine, and the hydrazide-containing compound is selected from biparat Benzohydrazide-terminated polyoxyethylene and/or N,N,N,N-tetrapropionylhydrazide-terminated polydimethylsiloxane;

The aldehyde compound is selected from at least one of trimesaldehyde, terephthalaldehyde, polyoxyethylene terminated with aldehyde group, and polydimethylsiloxane terminated with aldehyde group;

The organic metal lithium salt is selected from lithium bistrifluoromethanesulfonimide (LiTFSI), lithium perchlorate (LiCLO ₄ ), lithium hexafluorophosphate (LiPF ₆ ), lithium tetrafluoroborate (LiBF ₄ ), lithium hexafluoroarsenate (LiAsF ₆ ), at least one of lithium trifluoromethanesulfonate (LiTf).

其中，n代表聚氧乙烯二胺的聚合度，与聚氧乙烯二胺的数均分子量相对应。所述聚二甲基硅氧烷二胺的数均分子量为2000-10000g/mol，优选为3000-8000g/mol，其化学结构式表示为

其中，m代表聚二甲基硅氧烷二胺的聚合度，与聚二甲基硅氧烷二胺的数均分子量相对应。In a preferred embodiment, the amino group-containing compound is polyoxyethylene diamine or polydimethylsiloxane diamine. Wherein, the number average molecular weight of the polyoxyethylene diamine is 1000-10000g/mol, preferably 2000-4000g/mol, and its chemical structural formula is expressed as

Among them, n represents the polymerization degree of polyoxyethylene diamine, and corresponds to the number average molecular weight of polyoxyethylene diamine. The number-average molecular weight of the polydimethylsiloxane diamine is 2000-10000 g/mol, preferably 3000-8000 g/mol, and its chemical structural formula is expressed as

Among them, m represents the degree of polymerization of the polydimethylsiloxane diamine, which corresponds to the number average molecular weight of the polydimethylsiloxane diamine.

In a preferred embodiment, the aldehyde compound is trimesicaldehyde, and the organometallic lithium salt is lithium bistrifluoromethanesulfonimide.

In a preferred embodiment, the solvent is selected from ethanol, dimethyl sulfoxide (DMSO), dichloromethane (CH ₂ Cl ₂ ), trichloromethane (CHCl ₃ ), N,N-dimethylmethane At least one of the amides (DMF), preferably N,N-dimethylformamide and/or chloroform.

In a preferred embodiment, the contacting comprises: dissolving an amino group- or hydrazide-containing compound and an organometallic lithium salt in an organic solvent to obtain a mixed solution I; dissolving the aldehyde compound in an organic solvent to obtain a mixed solution II; then mixed solution I and mixed solution II were mixed.

In a preferred embodiment, in the mixed solution I, based on 1 mL of organic solvent, the addition amount of the compound containing amino group or hydrazide is 50mg-2.5g, preferably 100mg-2g; the addition amount of organometallic lithium salt is 0.5 -4 mmol, preferably 1-3 mmol.

Wherein, in the preparation method provided by the present invention, the organometallic lithium salt is basically not lost in the preparation process, and all enters into the prepared solvent-free polymer ion conductor.

In a preferred embodiment, when the amino- or hydrazide-containing compound is polyoxyethylene diamine, based on 1 mL of organic solvent, the amount of polyoxyethylene diamine added is 50-300 mg, preferably 100-200 mg ; When the compound containing amino group or hydrazide is polydimethylsiloxane diamine, based on 1 mL of organic solvent, the amount of polyoxyethylene diamine added is 0.5-2.5 g, preferably 1.5-2 g; when When the organometallic lithium salt is lithium bistrifluoromethanesulfonimide, based on 1 mL of organic solvent, the addition amount of lithium bistrifluoromethanesulfonimide is 0.1-1.5 g, preferably 0.3-0.9 g.

In a preferred embodiment, in the mixed solution II, based on 100 μL of the organic solvent, the addition amount of the aldehyde compound is 1-20 mg, preferably 5-15 mg.

In a preferred embodiment, the mixing volume ratio of the mixed solution I and the mixed solution II is 1 mL: 100-500 μL, preferably 1 mL: 125-300 μL.

In a preferred embodiment, the preparation of mixed solution I and mixed solution II is carried out at 40-80°C, preferably at 50-70°C, and then cooled to room temperature.

In a preferred embodiment, the mixed solution I and the mixed solution II are mixed and reacted at room temperature for 3-24 hours, preferably for 1-3 hours. Wherein, the present invention does not specifically limit the room temperature, which may be 10-40°C, preferably 25-35°C.

In a preferred embodiment, the drying is vacuum drying, and the conditions of the vacuum drying include: the vacuum drying temperature is 50-80°C, preferably 60-70°C; the vacuum drying time is 30-60h, preferably 45 -55h.

In a preferred embodiment, when the amino- or hydrazide-containing compound is polyoxyethylene diamine, the aldehyde compound is trimesaldehyde, and the organometallic lithium salt is bistrifluoromethanesulfonylidene In the case of lithium amide, the obtained solvent-free polymer ion conductor includes structural formula I and lithium bistrifluoromethanesulfonimide, wherein lithium bistrifluoromethanesulfonimide and the oxygen atom in structural formula I are connected in a complexed form,

Wherein, structural formula I is only for illustration, n1, n2 and n3 in formula I are related to the degree of polymerization n of polyoxyethylene diamine, and n1, n2 and n3 may be the same or different, and in formula I The tildes represent repeating units of polyoxyethylene diamine and trimesaldehyde.

In a preferred embodiment, when the amino- or hydrazide-containing compound is polydimethylsiloxane diamine, the aldehyde compound is trimesaldehyde, and the organometallic lithium salt is bistrifluoro When lithium methanesulfonimide is used, the obtained solvent-free polymer ion conductor includes structural formula II and lithium bistrifluoromethanesulfonimide, wherein lithium bistrifluoromethanesulfonimide and the oxygen atom in structural formula II are complexed with each other. Form connection

Wherein, structural formula II is only for illustration, m1, m2 and m3 in formula II are related to the degree of polymerization m of polydimethylsiloxane diamine, and m1, m2 and m3 may be the same or different, The tilde in formula II represents repeating units of polydimethylsiloxane diamine and trimesicaldehyde.

Among them, the solvent-free polymer ion conductor synthesized from the compound containing amino group or hydrazide and the aldehyde compound selected in the present invention has a three-dimensional network structure.

In the present invention, "solvent-free" means that the prepared polymer ion conductor does not contain the organic solvent used in the contact.

The second aspect of the present invention provides a solvent-free polymer ion conductor prepared by the preparation method described in the first aspect of the present invention.

In a preferred embodiment, the ionic conductivity of the solvent-free polymer ion conductor is 0.3×10 ^-4 S/cm-5×10 ^-4 S/cm at room temperature, preferably 0.4×10 ^-4 S/cm -3×10 ^-4 S/cm.

A third aspect of the present invention provides the application of a solvent-free polymer ion conductor in a battery.

The present invention will be described in detail below by means of examples. In the following examples, polyoxyethylene diamine was purchased from Aladdin, trade name P107103-5g, and the number average molecular weight was 2000 g/mol; polydimethylsiloxane diamine was purchased from Gelest, trade name DMS-A21, and the number average molecular weight was 5000g/mol.

Example 1

1) Dissolve 400 mg of polyoxyethylene diamine (P107103-5 g, number average molecular weight of 2000 g/mol) and 0.328 g of lithium bistrifluoromethanesulfonimide at 60°C in 2 mL of N,N-dimethylformaldehyde In the base formamide, mixed solution I is obtained;

2) Dissolve 25 mg of trimesicaldehyde in 300 μL of N,N-dimethylformamide at 60°C to obtain mixed solution II;

3) Mix the above-mentioned mixed solution I and the above-mentioned mixed solution II with a homogenizer and pour it into a polytetrafluoroethylene abrasive tool, remove the bubbles and react at room temperature for 2 hours to obtain a gel, and then place the obtained gel at 60 ° C. It was dried in a vacuum oven for 48h, so that the solvent N,N-dimethylformamide was completely volatilized, and a solvent-free polymer ionic conductor was obtained.

The infrared spectrum analysis of the solvent-free polymer ionic conductor obtained in Example 1 is carried out, and the results are shown in Figure 1: It can be seen from Figure 1 that the absorption peak at 1646 cm ^-1 corresponds to the stretching vibration of C=N, indicating the formation of Schiff base .

Example 2

1) Dissolve 2 g of polydimethylsiloxane diamine (DMS-A21, the number average molecular weight is 5000 g/mol) and 0.6 g of lithium bistrifluoromethanesulfonimide in 1 mL of trichloromethane at room temperature. In methane, mixed solution I was obtained;

2) 33 mg of trimesicaldehyde was dissolved in 300 μL of chloroform at room temperature to obtain mixed solution II;

3) Mix the above-mentioned mixed solution I and the above-mentioned mixed solution II with a homogenizer and pour it into a polytetrafluoroethylene abrasive tool, remove the bubbles and react at room temperature for 2 hours to obtain a gel, and then place the obtained gel at 60 ° C. It was dried in a vacuum oven for 48h, so that the solvent chloroform was completely volatilized, and a solvent-free polymer ion conductor was obtained.

The obtained solvent-free polymer ionic conductor was analyzed by infrared spectroscopy, and the results are shown in Figure 2: from Figure 2, it can be seen that the absorption peak at 1646cm ^-1 corresponds to the stretching vibration of C=N, indicating the formation of Schiff base, ^1700cm- The absorption peak of ¹ corresponds to the stretching vibration of C=O, which is caused by the addition of excess trimesicaldehyde to the system.

Example 3

1) 400 mg of polyoxyethylene diamine and 0.82 g of lithium bistrifluoromethanesulfonimide were dissolved in 4 mL of N,N-dimethylformamide at 60° C. to obtain mixed solution I;

2) Dissolve 25 mg of trimesicaldehyde in 500 μL of N,N-dimethylformamide at 60° C. to obtain mixed solution II;

3) Mix the above-mentioned mixed solution I and the above-mentioned mixed solution II with a homogenizer and pour it into a polytetrafluoroethylene abrasive tool, remove the bubbles and react at room temperature for 2 hours to obtain a gel, and then place the obtained gel at 60 ° C. It was dried in a vacuum oven for 48h, so that the solvent N,N-dimethylformamide was completely volatilized, and a solvent-free polymer ionic conductor was obtained.

Test Example 1

The solvent-free polymer ionic conductor prepared in Example 1 was subjected to thermogravimetric analysis on the TGA5500 instrument of TA Company. The test conditions were: the heating rate was 10 °C/min, and the heating range was 30 °C-650 °C. The test results are shown in the figure. 3 shows:

It can be seen from Figure 3 that the solvent-free polymer ion conductor has no weight loss before 350 °C, and the solvent-free polymer ion conductor begins to degrade after 350 °C. Therefore, the solvent-free polymer ion conductor prepared in Example 1 can be used in an environment below 350°C, which broadens its application prospects.

Test case 2

The ionic conductivity of the solvent-free polymer ion conductor prepared in Example 1 was tested on the electrochemical workstation CHI660E instrument. The test conditions were: the range was -40°C to 180°C, and the test results were shown in Figure 4:

It can be seen from Figure 2 that the conductivity of the solvent-free polymer ionic conductor is 2.04×10 ^-4 S/cm at 25°C, and the ionic conductivity is high at room temperature, which has a broader application prospect in the field of flexible electronic devices.

Under the same conditions, the ionic conductivity of the solvent-free polymer ionic conductor prepared in Example 2-3 was tested, and the ionic conductivity of the solvent-free polymer ionic conductor prepared in Example 2 at 25°C was 4.2×10 ^{− 5} S/cm, the ionic conductivity of the solvent-free polymer ion conductor prepared in Example 3 at 25°C is 2.4×10 ^-4 S/cm.

Test case 3

The self-healing test of the mechanical properties of the solvent-free polymer ion conductor prepared in Example 1 was carried out on the ESM301/Mark-10000 energy chemical testing machine. The test conditions were: the tensile rate was 30 mm/min, and the test results were as follows: As shown in Figure 5a: It can be seen from Figure 5a that the healing efficiency of the mechanical properties of the solvent-free polymer ion conductor prepared in Example 1 is above 95% at room temperature or at 60°C.

The resistance of the solvent-free polymer ionic conductor prepared in Example 1 was tested with a multimeter before and after healing. The test results are shown in Figure 5b: after cutting the ionic conductor, its resistance immediately returned to the original value within a few minutes, and more After the first cutting, its resistance does not increase, which indicates that the electrical properties of the solvent-free polymer ion conductors prepared in Example 1 have healing efficiencies of more than 95%.

The preferred embodiments of the present invention have been described above in detail, however, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, a variety of simple modifications can be made to the technical solutions of the present invention, including the combination of various technical features in any other suitable manner. These simple modifications and combinations should also be regarded as the content disclosed in the present invention. All belong to the protection scope of the present invention.

Claims (18)

1. a preparation method of a solvent-free polymer ion conductor, is characterized in that, described method comprises: first contacting compound, aldehyde compound, organometallic lithium salt containing amino group or hydrazide in organic solvent, reversible react with the base to obtain a gel, and then the gel is dried to obtain a solvent-free polymer ion conductor; Wherein, at least one of the amino- or hydrazide-containing compound and the aldehyde compound is a polymer; The amino group-containing compound is selected from at least one of polyoxyethylene diamine, polydimethylsiloxane diamine, trimesiamine, and p-phenylenediamine, and the hydrazide-containing compound is selected from biparat Benzohydrazide-terminated polyoxyethylene and/or N,N,N,N-tetrapropionylhydrazide-terminated polydimethylsiloxane; The aldehyde compound is selected from trimesaldehyde, terephthalaldehyde, 2,2,2-trisubstituted p-benzaldehyde methyl ether ethane, aldehyde group-terminated polyoxyethylene, aldehyde group-terminated polydimethylsilicon at least one of oxanes; The organic metal lithium salt is selected from at least one of lithium bistrifluoromethanesulfonimide, lithium perchlorate, lithium hexafluorophosphate, lithium tetrafluoroborate, lithium hexafluoroarsenate, and lithium trifluoromethanesulfonate. 2 . The preparation method according to claim 1 , wherein the amino group-containing compound is polyoxyethylene diamine and/or polydimethylsiloxane diamine. 3 . 3. The preparation method according to claim 2, wherein the number-average molecular weight of the polyoxyethylene diamine is 1000-10000 g/mol, and the number-average molecular weight of the polydimethylsiloxane diamine is 2000-10000 g/mol 10000g/mol. 4. The preparation method according to claim 3, wherein the number-average molecular weight of the polyoxyethylene diamine is 2000-4000 g/mol, and the number-average molecular weight of the polydimethylsiloxane diamine is 3000-4000- 8000g/mol. 5 . The preparation method according to claim 1 , wherein the aldehyde compound is trimesicaldehyde, and the organic metal lithium salt is lithium bistrifluoromethanesulfonimide. 6 . 6. The preparation method according to any one of claims 1-4, wherein the organic solvent is selected from ethanol, dimethyl sulfoxide, dichloromethane, chloroform, N,N-dimethylmethane at least one of the amides. 7. The preparation method according to claim 6, wherein the organic solvent is N,N-dimethylformamide and/or chloroform. 8. The preparation method according to any one of claims 1-4, wherein the contacting comprises: dissolving an amino- or hydrazide-containing compound and an organometallic lithium salt in an organic solvent to obtain a mixed solution I; The aldehyde compound is dissolved in the organic solvent to obtain the mixed solution II; then the mixed solution I and the mixed solution II are mixed. 9. preparation method according to claim 8, wherein, in mixed solution 1, based on the organic solvent of 1mL, the addition amount of the compound containing amino group or hydrazide is 50mg-2.5g, and the addition amount of organometallic lithium salt is 0.5g -4mmol. 10. preparation method according to claim 9, wherein, in the mixed solution 1, based on the organic solvent of 1mL, the addition amount of the compound containing amino group or hydrazide is 100mg-2g, and the addition amount of organometallic lithium salt is 1- 3 mmol. 11 . The preparation method according to claim 8 , wherein, in the mixed solution II, based on 100 μL of the organic solvent, the addition amount of the aldehyde compound is 1-20 mg. 12 . 12 . The preparation method according to claim 11 , wherein, in the mixed solution II, based on 100 μL of the organic solvent, the addition amount of the aldehyde compound is 5-15 mg. 13 . 13. The preparation method according to claim 8, wherein the mixing ratio of the mixed solution I and the mixed solution II is 1 mL: 100-500 μL; Mixed solution I and mixed solution II were mixed and reacted at room temperature for 1-24 h. 14. The preparation method according to claim 13, wherein the mixing ratio of the mixed solution I and the mixed solution II is 1 mL: 125-300 μL; Mixed solution I and mixed solution II were mixed and reacted at room temperature for 1-3 h. 15. A solvent-free polymer ion conductor prepared by the method of any one of claims 1-14. The preparation method according to claim 15, wherein the ionic conductivity of the solvent-free polymer ion conductor is 0.3×10 ⁻⁴ S/cm-5×10 ⁻⁴ S/cm at room temperature. The preparation method according to claim 16, wherein the ionic conductivity of the solvent-free polymer ion conductor is 0.4×10 ⁻⁴ S/cm ⁻³ ×10 ⁻⁴ S/cm at room temperature. 18. Use of a solvent-free polymer ionic conductor according to any one of claims 15-17 in a battery.

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