CN107069083B - A kind of solid polymer electrolyte membrane material with continuous ion transfer nanochannel and preparation method thereof - Google Patents

Abstract

The invention relates to a solid polymer electrolyte membrane material with continuous ion transfer nano-channels, which is a membrane formed by fusion and cross-linking of spherical micelles formed by self-assembly of amphiphilic polymers. The preparation method is as follows: selecting a co-solvent, configure a certain concentration of polycyclooctene-grafted polyethylene glycol (PCOE-g-MPEG) comb-shaped copolymer solution; select a selective solvent, slowly dropwise add the above-mentioned comb-shaped copolymer solution under stirring; The mixed solution is dialyzed; a certain amount of lithium salt is added to the above dialyzed micelle solution, and the volatile solvent is concentrated to obtain flocculent stacked micelles; oven heat treatment is performed to obtain a solid polymer electrolyte membrane. The solid polymer electrolyte membrane obtained by the invention can form a continuous ion transfer channel when the MPEG content is low, and maintain high electrical conductivity and good mechanical properties.

Description

A solid polymer electrolyte membrane material with continuous ion transfer nanochannels and preparation method thereof

technical field

The invention relates to a solid polymer electrolyte membrane material with continuous ion transfer nanochannels and a preparation method thereof, and belongs to the field of preparation of lithium ion solid polymer electrolyte membrane materials.

Background technique

Lithium-ion batteries are widely used in various consumer electronic products due to their advantages of high energy density and fast charging and discharging. The electrolyte used is mainly electrolyte containing lithium salt, which is easy to leak, flammable and explosive Security risks. Therefore, solid polymer electrolytes with excellent safety and stability have emerged, and they have begun to receive extensive attention and research.

Among many solid-state polymer electrolytes, polymer electrolytes based on polyethylene glycol (PEO) and polyethylene glycol monomethyl ether (MPEG) are considered to have relatively high electrochemical stability and ionic conductivity. It is the system with the most practical application potential. Initially, these copolymers were prepared into films by simple spin-coating or casting, and the results showed that the ionic conductivity of the films was low due to the poor continuity of the ion-conducting region. For example, Kosonen, H. et al. (Macromolecules, 2002, 35, 27) used PS block P4VP (covalently linked with low molecular weight PEO) polymer solution to directly dry the obtained polymer electrolyte membrane with conductivity at room temperature of only 10 ^{− 7-10-6 S} /cm. Recent studies have shown that thermal annealing and solvent annealing of the above polymer membranes can induce the formation of an ordered two-phase continuous structure in the membrane, and the formation of such continuous channels can ensure that the electrolyte membrane maintains good mechanical strength while maintaining good mechanical strength. ionic conductivity. For example, Schulze, MW et al. (Nano letters, 2014, 14, 1) reported a method based on one-pot polymerization to induce phase separation to form a two-phase continuous polymer electrolyte membrane, and the resulting ionic conductivity exceeded ^10-3 at 80 °C. s/cm. Villaluenga, I. et al. (Macromolecules, 2015, 48, 2) showed that the ionic conductivity of the polymer electrolyte membrane was greatly improved after the phase structure transition from layered to two-phase continuous by adding functionalized nanoparticles. However, from these examples, we can also see that this method of forming continuous channels by annealing is only suitable for polymer systems with high PEO/MPEG molecular weight or content, and its use conditions are limited due to the low temperature crystallinity of PEO/MPEG. is a high temperature environment. Therefore, how to make the system with low PEO/MPEG molecular weight or content form continuous ion conduction channels, and how to realize the low-temperature use value of solid polymer electrolytes are the research hotspots and difficulties in the future.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a solid polymer electrolyte membrane material with continuous ion transfer nano-channels and a preparation method thereof in view of the deficiencies of the above-mentioned prior art, which have continuous ion transfer MPEG channels and realize high conductance at room temperature. rate and good mechanical properties.

The technical scheme adopted by the present invention to solve the above-mentioned problems is:

A solid polymer electrolyte membrane material with continuous ion transfer nanochannels, which is a membrane formed by the fusion and cross-linking of micelles formed by self-assembly of amphiphilic polymers; wherein the morphology of the micelles is spherical or ellipsoid, and the size Range about 50nm-500nm

According to the above scheme, the amphiphilic polymer is a polycyclooctene grafted polyethylene glycol monomethyl ether (PCOE-g-MPEG) comb copolymer, and its structural formula is shown in formula 1, wherein the value of n The range is about 5-25, wherein the relative molecular mass of polyethylene glycol monomethyl ether is 350-750, and the content is 10-30 wt% (mass percentage).

According to the above scheme, the lithium salt is selected from lithium perchlorate, lithium hexafluorophosphate, lithium tetrafluoroborate, lithium bistrifluoromethanesulfonimide, and the like. The ratio ([Li]/[EO]) of lithium ions in the lithium salt to ether oxygen atoms in the amphiphilic polymer is between 1:4 and 1:12.

The present invention also provides a method for preparing the above-mentioned solid polymer electrolyte membrane material with continuous ion transfer nanochannels, the steps of which are as follows:

(6) select a kind of co-solvent, prepare polycyclooctene-grafted polyethylene glycol monomethyl ether (PCOE-g-MPEG) comb copolymer solution;

(7) selecting a selective solvent, slowly dropping the selective solvent into the comb-shaped copolymer solution obtained in step (1) under stirring to obtain a mixed solution;

(8) dialysis: the mixed solution obtained in step (2) is dialyzed to obtain spherical micelle solution;

(9) concentration: adding lithium salt to the obtained spherical micelle solution, volatilizing the solvent and concentrating to obtain flocculent stacked micelles;

(10) Crosslinking: the obtained flocculent stacked micelles are thermally oxidized to obtain a solid polymer electrolyte membrane material with continuous ion transfer nanochannels.

According to the above scheme, the co-solvent is a polycyclooctene grafted polyethylene glycol monomethyl ether (PCOE-g-MPEG) comb copolymer with good solubility for both the main chain (PCOE) and the side chain (MPEG) of the comb copolymer. solvent. Preferably, the co-solvent is selected from dichloromethane or trichloromethane.

According to the above scheme, the concentration of the comb copolymer solution in the step (1) is 0.1wt%～1wt%

According to the above scheme, the selective solvent is a good solvent for the side chain MPEG of the polycyclooctene grafted polyethylene glycol monomethyl ether (PCOE-g-MPEG) comb copolymer, and is a good solvent for the main chain PCOE is a poor solvent. Preferably, the selective solvent is selected from ethanol or methanol and the like.

According to the above scheme, the volume ratio of the selective solvent to the co-solvent is 3:1 to 1:3.

According to the above scheme, the conditions of the dialysis are: the molecular weight cut-off is less than or equal to 300KD, the time is 3-5d, and ethanol or methanol is used as the dialysate.

According to the above scheme, the ratio of lithium ions in the lithium salt to ether oxygen atoms in the comb copolymer ([Li]/[EO]) is between 1:4 and 1:12.

According to the above scheme, the temperature of the thermal oxygen treatment is 80°C to 100°C.

Compared with the prior art, the beneficial effects of the present invention are:

First, the polymer solid-state polymer electrolyte membrane material obtained in the present invention has continuous ion transfer MPEG channels, the ionic conductivity at room temperature (25° C.) is greater than 10 ^-3 s/cm, and at the same time, the polymer electrolyte membrane with low MPEG content is realized. Conductive channel formation and high electrical conductivity at room temperature (ie low temperature use value), as well as good mechanical properties.

Second, the polycyclooctene grafted polyethylene glycol monomethyl ether (PCOE-g-MPEG) comb copolymer used in the present invention self-assembles into micelles to prepare polymer electrolyte membranes with continuous ion transfer channels, PCOE-g-MPEG The g-MPEG comb copolymer solution will form spherical micelles with MPEG hydrophilic branched chain as shell and PCOE hydrophobic main chain as core during dialysis. After micelle concentration and thermal oxygen treatment, a continuous ionic conductor phase containing MPEG shell is obtained. The two-phase continuous polymer electrolyte membrane cross-linked with the PCOE core is fundamentally different from the existing methods of using solvent annealing or thermal annealing to induce the formation of a continuous phase region of the membrane, which provides a new idea for this field.

Third, in the polycyclooctene-grafted polyethylene glycol monomethyl ether (PCOE-g-MPEG) comb copolymer used in the present invention, the content of MPEG is low, and the relative molecular mass of the contained MPEG is low (350-750) , does not crystallize, realizes high conductivity at room temperature, and has good potential application value in the field of electronic devices used at low temperature; moreover, the PCOE main chain of the comb polymer contains unsaturated carbon-carbon double bonds, and the resulting polymer is obtained after thermal oxygen crosslinking The electrolyte membrane provides good mechanical strength and can be processed into various shapes as required.

Description of drawings

FIG. 1 is a schematic illustration of each implementation step of the solid polymer electrolyte membrane material with continuous ion transfer nanochannels according to the present invention.

FIG. 2 is a TEM photograph of the micelle solution obtained after dialysis in Example 1. FIG.

FIG. 3 is an SEM photograph of the solid polymer electrolyte membrane obtained after the thermal oxygen crosslinking treatment in Example 1. FIG.

Detailed ways

In order to better understand the present invention, the content of the present invention is further illustrated below in conjunction with the examples, but the present invention is not limited to the following examples.

In the following examples, the polycyclooctene-grafted polyethylene glycol monomethyl ether (PCOE-g-MPEG) comb copolymer has the structural formula shown in Formula 1, and its preparation method is not limited. The present invention provides a preparation method as follows:

(1) Under ice bath conditions, 0.32 mol of m-chloroperoxybenzoic acid (mCPBA) was dispersed in 800 mL of chloroform to obtain solution A; 0.32 mol of cyclooctadiene was dispersed in 80 mL of chloroform to obtain solution B; slowly add solution A dropwise to solution B, react at room temperature for 12 h, to obtain epoxycyclooctene;

(2) under argon atmosphere, disperse 0.889mol of epoxycyclooctene in 80mL of tetrahydrofuran to obtain solution C; disperse 0.0889mol of lithium aluminum hydride in 60mL of tetrahydrofuran to obtain solution D; slowly drop solution C It was added to solution D, added dropwise for 0.5 h under an ice bath, and then naturally warmed to room temperature and reacted for 12 h; after the reaction was completed, the reaction system was cooled to 0 °C, and saturated NH ₄ Cl was added to the system under an ice bath. The solution is until no more bubbles are generated in the system to obtain 5-hydroxy-1-cyclooctene;

(3) Under the protection of argon, 0.004 mol of polyethylene glycol monomethyl ether (MPEG, the relative molecular mass is selected from the range of 350 to 750 as required) is dispersed in 10 mL of toluene to obtain solution E; 0.0042 mol of 2,4-Tolyl diisocyanate (TDI) was dispersed in 10 mL of toluene to obtain solution F; solution E was added dropwise to solution F, reacted at 40 °C for 24 h, then heated to 90 °C, and then slowly added dropwise 8 mL of a toluene solution of 0.004mol 5-hydroxy-1-cyclooctene was reacted under argon protection for 24h to obtain a macromonomer;

(4) Under argon atmosphere, according to a certain ratio of macromonomer and cyclooctene (the molar ratio of macromonomer and cyclooctene is in the range of 1:30 to 1:5), dissolve in dichloromethane and add to Dried Schlenk bottle; in a small test tube, Grubbs' second-generation catalyst was dissolved in dichloromethane; after the above two solutions were respectively subjected to three cycles of freezing/evacuating/thawing, the catalyst solution was rapidly added dropwise to the monomer solution, The reaction was carried out at room temperature to obtain the target product - polycyclooctene grafted polyethylene glycol monomethyl ether (PCOE-g-MPEG) comb copolymer.

Above-mentioned gained polycyclooctene graft polyethylene glycol monomethyl ether (PCOE-g-MPEG) comb copolymer, its structural formula is as shown in formula 1, relative molecular mass is 5000-20000, the value of repeating unit number n The range is about 5-25, the relative molecular mass of polyethylene glycol monomethyl ether (MPEG) is 350-750, and the content is 10-30 wt%.

Example 1

A solid polymer electrolyte membrane material with continuous ion transfer nanochannels is a comb copolymer (molecular weight of 5000-20000) of polycyclooctene grafted polyethylene glycol monomethyl ether (PCOE-g-MPEG) The content of MPEG is 30wt%, the relative molecular mass of MPEG is 350) self-assembled micelles are fused with lithium salts, and the films formed by cross-linking; the micelles are spherical or ellipsoidal in shape, and the size ranges from about 50nm to 500nm.

The above-mentioned preparation method of the solid polymer electrolyte membrane material with continuous ion transfer nanochannel, the steps are as follows:

(1) Accurately weigh 0.05g PCOE-g-MPEG (MPEG relative molecular mass is 350, mass fraction is 30%) comb polymer is dissolved in 10g dry co-solvent CH ₂ Cl ₂ to obtain a mass fraction of 5‰ The comb copolymer solution;

(2) Measure 7.5ml of selective solvent ethanol, add above-mentioned comb copolymer solution dropwise with stirring at room temperature, and the volume ratio of selective solvent to co-solvent is 1:1;

(3) transferring the solution obtained in step (2) into a dialysis bag with a molecular weight cut-off of 3500, dialyzing in a large amount of ethanol for 3 to 5 days, replacing the dialysate once during the period, and obtaining a micellar emulsion after the dialysis finishes;

(4) fully shake the obtained micellar emulsion, add 0.005g anhydrous lithium perchlorate to it, make [Li]/[EO] be 1:8, and volatilize the solvent at room temperature to obtain a white flocculent deposit;

(5) Transfer the obtained flocculent deposit into an oven, and heat treatment at 80° C. for 12 h to obtain a solid polymer electrolyte membrane with continuous ion transfer nanochannels.

It can be seen from Figure 2 that the polycyclooctene-grafted polyethylene glycol monomethyl ether (PCOE-g-MPEG) comb copolymer, as an amphiphilic polymer, self-assembles into spherical micelles; The hydrophilic and hydrophobic properties of the main and side chains of the polymer show that the shell part of the spherical micelle is an MPEG chain, and the core part is a PCOE chain. Bond crosslinks provide mechanical strength

It can be seen from Figure 3 that the solid polymer electrolyte membrane obtained after the micelles are cross-linked by thermal oxygen is the fusion between the comb-shaped copolymer spherical micelles, and the spherical micelles are cross-linked together to form a solid polymer electrolyte membrane.

The solid polymer electrolyte membrane with continuous ion transfer nanochannels obtained in this example was tested for its AC impedance by an electrochemical workstation, and the conductivity calculation formula σ=L/R*S (where L is the film thickness, R is the resistance, S is the film area), the electrical conductivity is 3.42*10-4 s/cm, the tensile strength is 2.5MP, and the first discharge capacity at room temperature is ^87mAh /g.

Example 2

A preparation method of a solid polymer electrolyte membrane material with continuous ion transfer nanochannels, the steps of which are as follows:

(1) Accurately weigh 0.05g PCOE-g-MPEG (MPEG relative molecular mass is 350, mass fraction is 30%) comb polymer is dissolved in 10g dry co-solvent CH ₂ Cl ₂ to obtain a mass fraction of 5‰ The solution;

(2) Measure 7.5ml of selective solvent ethanol, add the above solution dropwise with stirring at room temperature, so that the volume ratio of the final selective solvent to the co-solvent is 1:1;

(3) transferring the obtained solution of (2) into a dialysis bag with a molecular weight cut-off of 3500, and dialyzing in a large amount of ethanol solution for 3 to 5 days, during which the dialysate is replaced once;

(4) the micellar emulsion obtained by fully shaking after the dialysis is finished, adding 0.010g anhydrous lithium perchlorate, so that [Li]/[EO] is 1:4, and the solvent is volatilized at room temperature to obtain a white flocculent deposit;

(5) Transfer the obtained flocculent deposit into an oven, and heat treatment at 80° C. for 12 h to obtain a solid polymer electrolyte membrane with continuous ion transfer nanochannels. The AC impedance was measured by EIS, and the conductivity calculation formula σ=L/R*S was used to obtain the conductivity of 8.75* ^10-5 s/cm, the tensile strength of 2.2MP, and the first discharge capacity at room temperature of 65mAh/g.

Example 3

A preparation method of a solid polymer electrolyte membrane material with continuous ion transfer nanochannels, the steps of which are as follows:

(1) Accurately weigh 0.05g PCOE-g-MPEG (MPEG relative molecular mass is 350, mass fraction is 30%) comb polymer is dissolved in 10g dry co-solvent CH ₂ Cl ₂ to obtain a mass fraction of 5‰ The solution;

(2) Measure 7.5ml of selective solvent ethanol, add the above solution dropwise with stirring at room temperature, so that the volume ratio of the final selective solvent to the co-solvent is 1:1;

(3) transferring the obtained solution of (2) into a dialysis bag with a molecular weight cut-off of 3500, and dialyzing in a large amount of ethanol solution for 3 to 5 days, during which the dialysate is replaced once;

(4) After the dialysis is completed, the micellar emulsion obtained by sufficient shaking is added, and 0.003 g of anhydrous lithium perchlorate is added, so that [Li]/[EO] is 1:12, and the solvent is volatilized at room temperature to obtain a white flocculent deposit;

(5) Transfer the obtained flocculent deposit into an oven, and heat treatment at 80° C. for 12 h to obtain a solid polymer electrolyte membrane with continuous ion transfer nanochannels. The AC impedance was measured by EIS, and the electrical conductivity was substituted into the formula σ=L/R*S to obtain a conductivity of 2.19* ^10-5 s/cm, a tensile strength of 2.9MP, and an initial discharge capacity of 96mAh/g at room temperature.

In Examples 1, 2, and 3, the MPEG chain length and content of the polycyclooctene-grafted polyethylene glycol monomethyl ether (PCOE-g-MPEG) comb copolymer were the same, and the content of lithium salt was changed. The results showed that [ When Li]/[EO] is 1:8, the ionic conductivity of the obtained solid polymer electrolyte membrane is higher, which may be because the utilization efficiency of lithium ions and ether oxygen atoms is the highest at this lithium salt content.

Example 4

A preparation method of a solid polymer electrolyte membrane material with continuous ion transfer nanochannels, the steps of which are as follows:

(1) Accurately weigh 0.05g PCOE-g-MPEG (MPEG relative molecular mass is 350, mass fraction is 25%) comb polymer is dissolved in 10g dry co-solvent CH ₂ Cl ₂ to obtain a mass fraction of 5‰ The solution;

(2) Measure 7.5ml of selective solvent ethanol ethanol, add the above solution dropwise under stirring at room temperature, so that the volume ratio of the final selective solvent to the co-solvent is 1:1;

(3) transferring the obtained solution of (2) into a dialysis bag with a molecular weight cut-off of 3500, and dialyzing in a large amount of ethanol solution for 3 to 5 days, during which the dialysate is replaced once;

(4) After the dialysis is completed, the micellar emulsion obtained by sufficient shaking is added, and 0.004g of anhydrous lithium perchlorate is added, so that [Li]/[EO] is 1:8, and the solvent is volatilized at room temperature to obtain a white flocculent deposit;

(5) Transfer the obtained flocculent deposit into an oven, heat treatment at 80° C. for 12 h, and obtain a solid polymer electrolyte membrane with continuous ion transfer nanochannels. The AC impedance was measured by EIS, and the electrical conductivity was substituted into the formula σ=L/R*S to obtain a conductivity of 2.69*10-4 s/cm, a tensile strength of ^3.2MP , and a first discharge capacity of 58mAh/g at room temperature.

Example 5

A preparation method of a solid polymer electrolyte membrane material with continuous ion transfer nanochannels, the steps of which are as follows:

(1) Accurately weigh 0.05g PCOE-g-MPEG (MPEG relative molecular mass is 350, mass fraction is 20%) comb polymer is dissolved in 10g dry co-solvent CH ₂ Cl ₂ to obtain a mass fraction of 5‰ The solution;

(2) Measure 7.5ml of selective solvent ethanol, add the above solution dropwise with stirring at room temperature, so that the volume ratio of the final selective solvent to the co-solvent is 1:1;

(3) transferring the obtained solution of (2) into a dialysis bag with a molecular weight cut-off of 3500, and dialyzing in a large amount of ethanol solution for 3 to 5 days, during which the dialysate is replaced once;

(4) the micellar emulsion obtained by fully shaking after the dialysis is finished, adding 0.003g of anhydrous lithium perchlorate, so that [Li]/[EO] is 1:8, and the solvent is volatilized at room temperature to obtain a white flocculent deposit;

(5) Transfer the obtained flocculent deposit into an oven, heat treatment at 80° C. for 12 h, and obtain a solid polymer electrolyte membrane with continuous ion transfer nanochannels. The AC impedance was measured by EIS, and the electrical conductivity was substituted into the formula σ=L/R*S. The electrical conductivity was 2.38*10-4 s/cm, the tensile strength was ^2.8MP , and the first discharge capacity at room temperature was 75mAh/g.

In Examples 1, 4 and 5, the length of the MPEG side chain of the polycyclooctene-grafted polyethylene glycol monomethyl ether (PCOE-g-MPEG) comb copolymer and the content of lithium salt in the solid polymer film are the same, and the side chains are the same. The content of chain MPEG (side chain branch density) gradually decreased, but the value of electrical conductivity did not change significantly. The reason may be that the MPEG chains in each embodiment formed a continuous MPEG ion transfer channel, and different mass fractions did not have much effect. .

Example 6

A preparation method of a solid polymer electrolyte membrane material with continuous ion transfer nanochannels, the steps of which are as follows:

(1) Accurately weigh 0.05g PCOE-g-MPEG (MPEG relative molecular mass is 550, mass fraction is 50%) comb polymer is dissolved in 10g dry co-solvent CH ₂ Cl ₂ to obtain a mass fraction of 5‰ The solution;

(2) Measure 7.5ml of selective solvent ethanol, add the above solution dropwise with stirring at room temperature, so that the volume ratio of the final selective solvent to the co-solvent is 1:1;

(3) transferring the obtained solution of (2) into a dialysis bag with a molecular weight cut-off of 3500, and dialyzing in a large amount of ethanol solution for 3 to 5 days, during which the dialysate is replaced once;

(4) the micellar emulsion obtained by fully shaking after the dialysis is finished, adding 0.008g anhydrous lithium perchlorate, so that [Li]/[EO] is 1:8, and the solvent is volatilized at room temperature to obtain a white flocculent deposit;

(5) Transfer the obtained flocculent deposit into an oven, heat treatment at 80° C. for 12 h, and obtain a solid polymer electrolyte membrane with continuous ion transfer nanochannels. The AC impedance was measured by EIS, and the electrical conductivity was substituted into the formula σ=L/R*S to obtain a conductivity of 8.32*10-4 s/cm, a tensile strength of 1.6MP, and an initial discharge capacity of ^92mAh /g at room temperature.

Example 7

A preparation method of a solid polymer electrolyte membrane material with continuous ion transfer nanochannels, the steps of which are as follows:

(1) Accurately weigh 0.05g PCOE-g-MPEG (MPEG relative molecular mass is 550, mass fraction is 40%) comb polymer is dissolved in 10g dry co-solvent CH ₂ Cl ₂ to obtain a mass fraction of 5‰ The solution;

(2) Measure 7.5ml of selective solvent ethanol, add the above solution dropwise with stirring at room temperature, so that the volume ratio of the final selective solvent to the co-solvent is 1:1;

(3) transferring the obtained solution of (2) into a dialysis bag with a molecular weight cut-off of 3500, and dialyzing in a large amount of ethanol solution for 3 to 5 days, during which the dialysate is replaced once;

(4) the micellar emulsion obtained by fully shaking after the dialysis is finished, adding 0.006g of anhydrous lithium perchlorate, so that [Li]/[EO] is 1:8, and the solvent is volatilized at room temperature to obtain a white flocculent deposit;

(5) Transfer the obtained flocculent deposit into an oven, heat treatment at 80° C. for 12 h, and obtain a solid polymer electrolyte membrane with continuous ion transfer nanochannels. The AC impedance was measured by EIS, and the electrical conductivity was substituted into the formula σ=L/R*S to obtain a conductivity of 3.46*10-4 s/cm, a tensile strength of 1.3MP, and a first discharge capacity of ^66mAh /g at room temperature.

Example 8

A preparation method of a solid polymer electrolyte membrane material with continuous ion transfer nanochannels, the steps of which are as follows:

(1) Accurately weigh 0.05g PCOE-g-MPEG (MPEG relative molecular mass is 750, mass fraction is 60%) comb polymer is dissolved in 10g dry co-solvent CH ₂ Cl ₂ to obtain a mass fraction of 5‰ The solution;

(2) Measure 7.5ml of selective solvent ethanol, add the above solution dropwise with stirring at room temperature, so that the volume ratio of the final selective solvent to the co-solvent is 1:1;

(3) transferring the obtained solution of (2) into a dialysis bag with a molecular weight cut-off of 3500, and dialyzing in a large amount of ethanol solution for 3 to 5 days, during which the dialysate is replaced once;

(4) After the dialysis is completed, the micellar emulsion obtained by sufficient shaking is added, and 0.009g of anhydrous lithium perchlorate is added, so that [Li]/[EO] is 1:8, and the solvent is volatilized at room temperature to obtain a white flocculent deposit;

(5) Transfer the obtained flocculent deposit into an oven, heat treatment at 80° C. for 12 h, and obtain a solid polymer electrolyte membrane with continuous ion transfer nanochannels. The AC impedance was measured by EIS, and the electrical conductivity was substituted into the formula σ=L/R*S. The electrical conductivity was 1.62*10-4 s/cm, the tensile strength was ^0.9MP , and the first discharge capacity at room temperature was 72mAh/g.

Example 9

A preparation method of a solid polymer electrolyte membrane material with continuous ion transfer nanochannels, the steps of which are as follows:

(1) Accurately weigh 0.05g PCOE-g-MPEG (MPEG relative molecular mass is 750, mass fraction is 50%) comb polymer is dissolved in 10g dry co-solvent CH ₂ Cl ₂ to obtain a mass fraction of 5‰ The solution;

(2) Measure 7.5ml of selective solvent ethanol, add the above solution dropwise with stirring at room temperature, so that the volume ratio of the final selective solvent to the co-solvent is 1:1;

(3) transferring the obtained solution of (2) into a dialysis bag with a molecular weight cut-off of 3500, and dialyzing in a large amount of ethanol solution for 3 to 5 days, during which the dialysate is replaced once;

(4) the micellar emulsion obtained by fully shaking after the dialysis is finished, adding 0.008g anhydrous lithium perchlorate, so that [Li]/[EO] is 1:8, and the solvent is volatilized at room temperature to obtain a white flocculent deposit;

(5) Transfer the obtained flocculent deposit into an oven, heat treatment at 80° C. for 12 h, and obtain a solid polymer electrolyte membrane with continuous ion transfer nanochannels. The AC impedance was measured by EIS, and the conductivity calculation formula σ=L/R*S was substituted to obtain a conductivity of 1.35*10-4 s/cm, a tensile strength of ^1.8MP , and a first discharge capacity of 54mAh/g at room temperature.

To sum up, the ionic conductivity of the solid polymer electrolyte membrane of the present invention can reach ^10-3 s/cm, the tensile strength is about 1-3MP, and the first discharge capacity at room temperature is about 50mAh/g-100mAh/g.

The above are only the preferred embodiments of the present invention. It should be pointed out that for those of ordinary skill in the art, some improvements and transformations can be made without departing from the inventive concept of the present invention, which all belong to the present invention. scope of protection.

Claims (8)

1. a preparation method with the solid-state polymer electrolyte membrane material of continuous ion transfer nanochannel is characterized in that the steps are as follows: (1) select a co-solvent to prepare a polycyclooctene-grafted polyethylene glycol monomethyl ether comb copolymer solution; co-solvent selects dichloromethane or chloroform; (2) selecting a selective solvent, adding the selective solvent dropwise to the comb copolymer solution obtained in step (1) under stirring to obtain a mixed solution; the selective solvent is selected from ethanol or methanol; (3) dialysis: the mixed solution obtained in step (2) is dialyzed to obtain a spherical micelle solution; wherein, the spherical micelle size range is 50-500 nm; (4) concentration: adding lithium salt to the obtained spherical micelle solution, volatilizing the solvent, and concentrating to obtain flocculent stacked micelles; (5) Crosslinking: the obtained flocculent stacked micelles are treated with thermal oxygen to obtain a solid polymer electrolyte membrane material with continuous ion transfer nanochannels; The polycyclooctene grafted polyethylene glycol monomethyl ether comb copolymer, its structural formula is as shown in formula 1, Wherein the value of n ranges from 5 to 25, the relative molecular mass of polyethylene glycol monomethyl ether is 350 to 750, and the polyethylene glycol monomethyl ether block accounts for the polycyclooctene grafted polyethylene glycol monomethyl ether. The content of the comb copolymer is 10 to 30 wt %. 2. The method for preparing a solid polymer electrolyte membrane material with continuous ion transfer nanochannels according to claim 1, wherein the lithium salt is lithium perchlorate, lithium hexafluorophosphate, lithium tetrafluoroborate or bistris One or more of lithium fluoromethanesulfonimide. 3. the preparation method of a kind of solid polymer electrolyte membrane material with continuous ion transfer nano-channel according to claim 1, is characterized in that the lithium ion in described lithium salt and polycyclooctene graft polyethylene glycol The ratio of ether oxygen atoms ([Li]/[EO]) in the monomethyl ether comb copolymer is between 1:4 and 1:12. 4 . The method for preparing a solid polymer electrolyte membrane material with continuous ion transfer nanochannels according to claim 1 , wherein the volume ratio of the selective solvent to the co-solvent is 3:1 to 1:3. 5 . 5. The method for preparing a solid polymer electrolyte membrane material with continuous ion transfer nanochannels according to claim 1, wherein the concentration of the comb copolymer solution in the step (1) is 0.1wt %～1wt%. 6 . The method for preparing a solid polymer electrolyte membrane material with continuous ion transfer nanochannels according to claim 1 , wherein the dialysis conditions are: molecular weight cut-off is less than or equal to 300KD, and the time is 3-5 d, 7 . Ethanol or methanol was used as the dialysate. 7. The solid polymer electrolyte membrane material with continuous ion transfer nanochannels obtained by the method of claim 1. 8. The solid polymer electrolyte membrane material with continuous ion transfer nanochannels according to claim 7, characterized in that its room temperature ionic conductivity is greater than ^10-3 S/cm.

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