CN111934007B - Crosslinked organic nano material modified all-solid-state polymer electrolyte and preparation method thereof - Google Patents

Abstract

The invention belongs to the field of lithium ion batteries, and particularly relates to a cross-linked organic nano-material modified all-solid polymer electrolyte and a preparation method thereof. The invention provides an all-solid polymer electrolyte. The composition of the all-solid polymer electrolyte includes: a polymer with lithium ion transport properties, a lithium salt and an organic filler, wherein the organic filler is a diblock copolymer through a gram reaction for template-free self-assembly of cross-linked organic nanomaterials. The obtained polymer electrolyte has high ionic conductivity and other excellent electrochemical properties, and still has good dimensional stability under the condition of up to 200°C compared with general all-solid-state polymer electrolytes.

Description

All-solid-state polymer electrolyte modified by cross-linked organic nanomaterials and preparation method thereof

technical field

The invention belongs to the field of lithium ion batteries, and particularly relates to a cross-linked organic nano-material modified all-solid polymer electrolyte and a preparation method thereof.

Background technique

Commercial lithium-ion batteries generally have four key components: cathode material, anode material, electrolyte, and separator. Among them, the positive and negative materials largely determine the battery's capacity, operating voltage range, and charge-discharge rate. However, in terms of long-range cycle stability and safety, the performance of the battery is inseparable from its separator and electrolyte system. relation. The thermal shrinkage of the separator and the leakage of the electrolyte will cause huge safety hazards, such as burning and explosion, when the battery is subjected to thermal abuse or mechanical abuse. In response to these problems, the commercial market chooses to coat a layer of ceramic materials with mechanical reinforcement and high temperature resistance on the surface of polyolefin-based separators with micron-sized pore sizes that are commonly used before, or use methods such as multi-layer composite membranes for modification. These methods do reduce the thermal risk of lithium-ion batteries to a certain extent, but they cannot fundamentally solve the problem. Inflammable and explosive carbonate organic electrolytes still pose a threat to the safe use of lithium-ion batteries. The emergence of polymer electrolytes has largely solved the problem of liquid leakage of lithium-ion batteries and improved the safety performance of lithium-ion batteries.

Currently, all-solid state polymer electrolytes (SPEs) are being extensively studied due to their inherent advantages such as light weight, good mechanical stability and processability, and no liquid. All-solid-state lithium-ion batteries that have the possibility of use need to meet three basic conditions: ① the ionic conductivity at the operating temperature is greater than 10 ^-4 S·cm ^-1 ; ② the interface impedance between the all-solid electrolyte and the electrode is small and the interface is stable Good; ③ The all-solid electrolyte should have certain mechanical strength and flexibility to suppress the growth of lithium dendrites and buffer the volume change of the electrode material during discharge. At present, the research that can basically meet the above requirements mainly focuses on polymer-based composite solid electrolytes with ceramic materials with different morphologies as additives. Therefore, the preparation of organic fillers with excellent ion transport ability, high thermal stability, and good compatibility with polymer matrix and positive and negative electrode materials for all-solid-state electrolytes has broad development prospects.

SUMMARY OF THE INVENTION

In view of the above-mentioned defects, the present invention provides a cross-linked organic nanomaterial modified all-solid polymer electrolyte, and the obtained polymer electrolyte has high ionic conductivity and other excellent electrochemical properties.

Technical scheme of the present invention:

The first technical problem to be solved by the present invention is to provide an all-solid polymer electrolyte, the composition of which includes: a polymer with lithium ion transport properties, a lithium salt and an organic filler, wherein the organic filler is a diblock copolymer through Cross-linked organic nanomaterials obtained by Friedel-Crafts reaction without template self-assembly.

Further, the first component of the diblock copolymer is polyethylene oxide (PEO), polypropylene oxide (PPOX), polyphenylene ether (PPO) or poly(polyethylene glycol methyl ether methacrylate) ( P(PEGMA)); the second component is polystyrene or a polymer of styrene-derived monomers without strong electron withdrawing groups.

Further, in the all-solid polymer electrolyte, the molar ratio of the polymer with lithium ion transport properties to the lithium salt satisfies: M:Li=10-20, and the mass fraction of the organic filler in the electrolyte is 5-30%; wherein M is a structural unit (eg, EO in PEO) that interacts with lithium salts (ie, plays an actual role) in the polymer with lithium ion transport properties.

Further, the method for the cross-linked organic nanomaterial obtained by the template-free self-assembly of the diblock copolymer through Friedel-Crafts reaction is: under anhydrous and oxygen-free conditions, a diblock copolymer (such as PEO-PS) As raw material, under the action of catalyst, cross-linking agent and solvent, organic cross-linked nano-filler is obtained through Friedel-Crafts alkylation reaction; wherein, the volume fraction of cross-linking agent in the total volume of cross-linking agent and solvent is: 0% ~90%.

Preferably, the volume fraction of the crosslinking agent in the total volume of the crosslinking agent and the solvent is 50% to 90%.

Further, the crosslinking agent is selected from: dimethoxymethane or ethylene glycol dimethyl ether.

Further, the catalyst is selected from at least one of FeCl ₃ , AlCl ₃ , BF ₃ , H ₂ SO ₄ , SnCl ₄ or ZnCl ₂ .

Further, the solvent is selected from at least one of 1,2-dichloroethane (DCE) or dichloromethane.

Further, the Friedel-Crafts alkylation reaction process is as follows: adding the diblock copolymer and the catalyst to the solvent and the cross-linking agent, stirring to make the components evenly dispersed; then refluxing the reaction at 25-80° C. for 24-25 hours After the reaction, add ethanol, carry out ultrasonic dispersion and suction filtration to obtain the product; then wash the product with methanol and dilute hydrochloric acid in turn, and finally extract the product with methanol for 48-72 hours, collect and vacuum dry to obtain cross-linked organic nanofillers.

Further, the electrochemical window of the all-solid polymer electrolyte reaches 4.8-5.0V.

Further, the polymer with lithium ion transport properties is selected from one of polyether polymers, polyacrylates, polyacrylonitrile or polyvinylidene fluoride.

Further, the polymer with lithium ion transport properties is selected from: polyethylene oxide (PEO), polymethyl methacrylate (PMMA), polyacrylonitrile (PAN), polyvinylidene fluoride (PVDF) or polyvinylidene fluoride (PVDF) At least one of vinyl fluoride-hexafluoropropylene copolymer (PVDF-HFP).

Further, the lithium salt is selected from: lithium perchlorate, lithium hexafluoroarsenate, lithium tetrafluoroborate, lithium hexafluorophosphate, lithium bis(trifluoromethanesulfonyl)imide, lithium bisfluorosulfonimide, trifluoromethane At least one of lithium sulfonate, lithium bis-oxalate borate or lithium difluorooxalate borate.

The second technical problem to be solved by the present invention is to provide a preparation method of the above-mentioned all-solid polymer electrolyte, and the preparation method includes a solution casting method or a fusion hot pressing method.

Further, the solution casting method is as follows: firstly, a polymer with lithium ion transport properties, a lithium salt, a solvent and an organic filler are stirred and mixed to obtain an electrolyte slurry; and then the obtained electrolyte slurry is formed by casting and drying to obtain the All solid-state polymer electrolytes.

Further, the solution casting method comprises the following steps:

1) Preparation of electrolyte slurry: In an argon-filled glove box (H ₂ O <0.1 ppm, O ₂ <0.1 ppm), a polymer with lithium ion transport properties and a lithium salt were added to the solvent, and the Stir at room temperature; then add organic fillers and continue to stir until uniformly dispersed to obtain electrolyte slurry;

2) Casting and molding of electrolyte slurry: under anhydrous and oxygen-free conditions, after degassing the electrolyte slurry, use a Teflon mold to cast the electrolyte slurry, and then dry to obtain a polymer electrolyte membrane; and place it in a glove box medium spare.

Further, in step 1), the solvent is selected from at least one of acetonitrile, N,N-dimethylformamide, acetone, dichloromethane or tetrahydrofuran.

Preferably, the solvent is a mixed solvent of acetonitrile and tetrahydrofuran in a volume ratio of 1:8 to 1:4, more preferably 1:5.

Further, in step 1), the molar ratio of the polymer with lithium ion transport properties and the lithium salt satisfies: M:Li=10-20, the mass fraction of the organic filler in the electrolyte is 5-30%; A structural unit in a polymer with ion transport properties that interacts with (ie plays an actual role) with a lithium salt.

Further, in step 1), after adding a polymer with lithium ion transport properties and a lithium salt, the stirring speed is 300-400 rpm; the stirring time is 12-18 h to obtain a uniform mixed solution.

Further, in step 1), the organic filler needs to be ground for 1-2h (5-30wt%) before adding; the stirring speed after adding is 300-400rpm; the stirring time is 48-72h to obtain a uniform electrolyte slurry.

Further, in step 2), the electrolyte slurry is subjected to defoaming treatment by standing for 20-30 min.

Further, in step 2), the drying conditions are as follows: the polymer electrolyte membrane can be obtained after drying at 20-30° C. and 50-70° C. for 24-30 h respectively. In the present invention, the purpose of drying in two steps is: first, drying at room temperature is to allow the solvent to volatilize slowly, so as to avoid the influence on the shape and physical properties of the electrolyte during this process; then drying at high temperature is to further dry the electrolyte after molding. Remove residual solvent.

The third technical problem to be solved by the present invention is to provide the application of the diblock copolymer in the all-solid polymer electrolyte, and the crosslinked organic nanomaterial is obtained by performing template-free self-assembly of the diblock copolymer through Friedel-Crafts reaction, The obtained cross-linked organic nanofiller is combined with a polymer with lithium ion transport properties and a lithium salt to obtain an all-solid polymer electrolyte by a solution casting method or a melt hot pressing method.

Further, the molar ratio of the polymer with lithium ion transport properties to the lithium salt satisfies: M:Li=10-20, and the mass fraction of the cross-linked organic nanomaterial in the electrolyte is 5-30%; where M is lithium ion transport. Structural units (such as EO in PEO) that interact with lithium salts (ie, play an actual role) in a polymer with high performance.

Further, the first component of the diblock copolymer is polyethylene oxide (PEO), polypropylene oxide (PPOX), polyphenylene ether (PPO) or poly(polyethylene glycol methyl ether methacrylate) ( P(PEGMA)); the second component is polystyrene or a polymer of styrene-derived monomers without strong electron withdrawing groups.

The beneficial effects of the present invention are:

1. The present invention improves the thermal stability and mechanical properties of the all-solid polymer electrolyte through the cross-linked structure; improves the compatibility between the nanofiller and the polymer matrix and the positive and negative electrode materials through flexible segments such as PEO; The increased specific surface accelerates the transport of lithium ions.

2. Compared with the general all-solid polymer electrolyte, the cross-linked organic nanomaterial modified all-solid polymer electrolyte prepared by the present invention still has good dimensional stability under the condition of up to 200°C, thereby ensuring the battery The electrolyte membrane will not undergo large dimensional shrinkage when used under high temperature conditions, avoiding the occurrence of internal short circuits caused by the contact between the positive and negative electrodes of the battery; in addition, with the increase of the use temperature, the electrochemical performance of the electrolyte will be improved. further improvement.

3. The all-solid polymer electrolyte obtained by the present invention can be used for: (1) small household electrical appliances, such as mobile phones, computers and cameras; (2) some industries that need to work in high temperature environments, such as the electric vehicle industry, Underground oil production industry and aerospace industry. That is to say, the all-solid polymer electrolyte obtained in the present invention can be used in a wide temperature range.

Description of drawings:

Fig. 1 is the SEM characterization results of the cross-linked organic nanomaterials in the present invention: (a-b) are the SEM images of the added cross-linked organic nanomaterials HCPs-1 in Examples 1 and 6 of the present invention at different magnifications (c-d) are the scanning electron microscope images under different magnifications of the added cross-linked organic nanomaterial HCPs-2 in the embodiment of the present invention 2 and the embodiment 7; (e-f) are the embodiment of the present invention 3 and the embodiment 8. Scanning electron microscope images of the added cross-linked organic nanomaterial HCPs-3 under different magnifications; (g-h) are the scanning under different magnifications of the added cross-linked organic nanomaterial HCPs-4 in Example 4 and Example 9 of the present invention Electron micrograph; it can be seen from Figure 1 that the prepared organic materials HCPs-1, HCPs-2, HCPs-3 and HCPs-4 are all nanomaterials.

Figure 2 is a digital image of the all-solid polymer electrolytes in Examples 1-3 and 5 of the present invention after heat treatment at different temperatures; it can be seen from Figure 2 that the surface of the electrolyte prepared by the present invention is smooth, uniform and defect-free, which can ensure Good interfacial contact inside the battery; in addition, the polymer electrolyte SPE-PEO of the reference sample in Example 5 obviously increased in viscosity from 120 °C and completely melted at 160 °C, while the polymer electrolytes in Examples 1-3 were at Better dimensional stability is guaranteed at elevated temperatures.

Fig. 3 is the electrochemical AC impedance spectra of the all-solid polymer electrolytes of Example 2 and Example 5 at different test temperatures: Fig. 3(a) is the cross-linked organic nanomaterial modified all-solid polymer electrolyte MSPE in Example 2 -2 electrochemical AC impedance spectra at different test temperatures; Figure 3(b) is the electrochemical AC impedance spectra of the reference sample SPE-PEO in Example 5 at different test temperatures; At temperature, the interface impedance of the cross-linked organic nanomaterial modified all-solid polymer electrolyte (the diameter of the semi-circle is the interface impedance value) hardly changes compared with the reference sample SPE-PEO; The material is well dispersed in the electrolyte and has good compatibility with the electrodes.

Figure 4 is the linear sweep voltammetry curve of the all-solid polymer electrolyte in Examples 1-5; it can be seen from Figure 4 that the electrolyte prepared by the present invention has an excellent electrochemical window, which can meet the voltage range requirements of different batteries.

Fig. 5 is the test curve of the rate and cycle performance of the Li/MSPE-2/LiFePO ₄ coin cell assembled with the all-solid polymer electrolyte MSPE-2 in Example 2 of the present invention at 50°C; it can be seen from Fig. 5 that: The prepared electrolyte has good charge-discharge performance at this temperature, which meets the needs of practical applications.

Detailed ways

The following lists some specific embodiments of the present invention, but the present invention is obviously not limited to the following embodiments, and many modifications are possible.

Example 1

The preparation of an all-solid polymer electrolyte modified with cross-linked organic nanomaterials HCPs-1 and EO:Li=16 includes the following steps:

1) Preparation of mPEO-Br macroinitiator:

Under an argon atmosphere with dehydration and deoxygenation, 8g polyethylene glycol monomethyl ether (mPEG) and 0.12g 4-dimethylaminopyridine were added to 130mL dichloromethane, stirred until mPEG was dissolved, and then 4.22mL triethylamine was added. (TEA); 20 mL of dichloromethane was added to another anhydrous and oxygen-free container, and 3.76 mL of 2-bromoisobutyryl bromide (BIBB) was dissolved in it at about 0 °C; under the condition of about 0 °C , slowly add the dichloromethane solution of BIBB into the first container, then heat up to 25-35 °C, and stir for 15-20 h; after the reaction, filter off the triethylamine bromate generated by triethylamine, and then use saturated NaHCO ₃ and water were washed several times to remove unreacted BIBB in the system; then a large amount of anhydrous Na ₂ SO ₄ was added for drying to remove the residual water in the system; after Na ₂ SO ₄ was filtered off, a large amount of DCM was evaporated to remove solvent, and then sedimentation in diethyl ether to obtain a white solid, which was washed with diethyl ether for several times and dried to obtain mPEO-Br macromolecular initiator.

2) Preparation of PEO-PS diblock copolymer:

Under anhydrous and oxygen-free conditions, 2 g of mPEO-Br prepared in step 1), 0.14 g of CuBr and 20 mL of dioxane were added, stirred and dissolved, and then 8.57 mL of St was added, followed by 0.31 mL of N,N,N', N,'N"-pentamethyldiethylenetriamine (PMDETA), stir at a temperature of 100-120 ° C for 12-36 h; after the reaction, the reaction solution is diluted with THF, preferably alkaline Al ₂ O _3. The copper salt is removed by a short column, and a large amount of THF solvent is removed by evaporation, which is precipitated in n-hexane, and dried to obtain a PEO-PS two-block copolymer.

3) Preparation of cross-linked organic nanomaterials HCPs-1:

Under anhydrous and anaerobic conditions, 0.2775g PEO-PS and 2.925g FeCl ₃ were added to 30 mL DCE, and stirred for about five minutes to make the components dispersed uniformly; A large amount of ethanol was added, ultrasonic dispersion and suction filtration were carried out to obtain the product; the product was washed with methanol and dilute hydrochloric acid, and finally extracted with methanol for two days, collected and vacuum-dried to obtain the cross-linked organic nanomaterial HCPs-1.

4) Preparation of cross-linked organic nanomaterial modified all-solid polymer electrolyte 1:

Preparation of electrolyte slurry: In an argon-filled glove box ( _H2O <0.1ppm, _O2 <0.5ppm), 1.225g PEO and 0.5g LiTFSI were dissolved in a mixed solvent of 25mL tetrahydrofuran and 5mL acetonitrile, and Stir at room temperature at 300-400 rpm for 12-18 h; then add 0.192 g of cross-linked organic nanomaterial HCPs-1 (accounting for 10 wt% of all solid components) ground for 1-2 h, and stir at 300-400 rpm for 48-72 h to obtain Homogeneous electrolyte slurry.

Casting of electrolyte slurry: Under anhydrous and oxygen-free conditions, the electrolyte slurry is first subjected to static defoaming treatment for 20 to 30 minutes, and then Teflon mold is used to cast the electrolyte slurry. Dry at ~70°C for at least 24h; the obtained polymer electrolyte is referred to as MSPE-1 for short.

Example 2

The preparation of an all-solid polymer electrolyte modified with cross-linked organic nanomaterials HCPs-2 and EO:Li=16 includes the following steps:

1) the preparation of mPEO-Br macromolecular initiator: the concrete method is the same as the step 1 of embodiment 1);

2) Preparation of PEO-PS diblock copolymer: the specific method is the same as step 2 in Example 1);

3) Preparation of cross-linked organic nanomaterials HCPs-2:

Under anhydrous and anaerobic conditions, 0.2775g PEO-PS and 2.925g FeCl ₃ were added to 15mL DCE, then 15mL FDA was added and stirred for five minutes to make the components dispersed uniformly; then the reaction was refluxed at 25～80℃ for 24～25h After the reaction, a large amount of ethanol was added, ultrasonic dispersion and suction filtration were carried out to obtain the product; the product was washed with methanol and dilute hydrochloric acid, and finally extracted with methanol for two days, collected and vacuum-dried to obtain the cross-linked organic nanomaterial HCPs-2.

4) Preparation of cross-linked organic nanomaterial modified all-solid polymer electrolyte 2:

Preparation of electrolyte slurry: In an argon-filled glove box ( _H2O <0.1ppm, _O2 <0.5ppm), 1.225g PEO and 0.5g LiTFSI were dissolved in a mixed solvent of 25mL tetrahydrofuran and 5mL acetonitrile, and Stir at room temperature at 300-400rpm for 12-18h; then add 0.192g of cross-linked organic nanomaterial HCPs-2 (accounting for 10wt% of all solid components) ground for 1-2h, and stir at 300-400rpm for 48-72h to obtain Homogeneous electrolyte slurry.

Casting of electrolyte slurry: Under anhydrous and oxygen-free conditions, the electrolyte slurry is first subjected to static defoaming treatment for 20 to 30 minutes, and then Teflon mold is used to cast the electrolyte slurry. Dry at ~70°C for at least 24h; the obtained polymer electrolyte is referred to as MSPE-2.

Example 3

The preparation of an all-solid polymer electrolyte modified with crosslinked organic nanomaterials HCPs-3 and EO:Li=16 includes the following steps:

1) the preparation of mPEO-Br macromolecular initiator: the concrete method is the same as the step 1 of embodiment 1);

2) Preparation of PEO-PS diblock copolymer: the specific method is the same as step 2 in Example 1);

3) Preparation of cross-linked organic nanomaterials HCPs-3:

Under anhydrous and anaerobic conditions, 0.2775g PEO-PS and 2.925g FeCl ₃ were added into 6mL DCE, and then 24mL FDA was added and stirred for five minutes to make the components dispersed uniformly; then the reaction was refluxed at 25～80℃ for 24～25h; After the reaction, a large amount of ethanol was added, ultrasonic dispersion and suction filtration were carried out to obtain the product; the product was washed with methanol and dilute hydrochloric acid, and finally extracted with methanol for two days, collected and vacuum-dried to obtain the cross-linked organic nanomaterial HCPs-3;

4) Preparation of cross-linked organic nanomaterial modified all-solid polymer electrolyte 3:

Preparation of electrolyte slurry: In an argon-filled glove box ( _H2O <0.1ppm, _O2 <0.5ppm), 1.225g PEO and 0.5g LiTFSI were dissolved in a mixed solvent of 25mL tetrahydrofuran and 5mL acetonitrile, and Stir at room temperature at 300-400rpm for 12-18h; then add 0.192g of cross-linked organic nanomaterial HCPs-3 ground for 1-2h (accounting for 10wt% of all solid components), and stir at 300-400rpm for 48-72h to obtain a uniform electrolyte slurry.

Casting of electrolyte slurry: Under anhydrous and oxygen-free conditions, the electrolyte slurry is first subjected to static defoaming treatment for 20 to 30 minutes, and then Teflon mold is used to cast the electrolyte slurry. Dry at ~70°C for at least 24h; the obtained polymer electrolyte is referred to as MSPE-3 for short.

Example 4

The preparation of an all-solid polymer electrolyte modified with cross-linked organic nanomaterials HCPs-4 and EO:Li=16 includes the following steps:

1) the preparation of mPEO-Br macromolecular initiator: the concrete method is the same as the step 1 of embodiment 1);

2) Preparation of PEO-PS diblock copolymer: the specific method is the same as step 2 in Example 1);

3) Preparation of cross-linked organic nanomaterials HCPs-4:

Under anhydrous and anaerobic conditions, 0.2775g PEO-PS and 2.925g FeCl ₃ were added to 3mL DCE, then 27mL FDA was added and stirred for 5 minutes to make the components dispersed uniformly; then the reaction was refluxed at 25～80℃ for 24～25h; After the reaction, a large amount of ethanol was added, ultrasonic dispersion and suction filtration were carried out to obtain the product; the product was washed with methanol and dilute hydrochloric acid, and finally extracted with methanol for two days, collected and vacuum-dried to obtain the cross-linked organic nanomaterial HCPs-4.

4) Preparation of cross-linked organic nanomaterial modified all-solid polymer electrolyte 4:

Preparation of electrolyte slurry: In an argon-filled glove box ( _H2O <0.1ppm, _O2 <0.5ppm), 1.225g PEO and 0.5g LiTFSI were dissolved in a mixed solvent of 25mL tetrahydrofuran and 5mL acetonitrile, and Stir at room temperature at 300-400 rpm for 12-18 h; then add 0.192 g of cross-linked organic nanomaterial HCPs-4 (accounting for 10 wt% of all solid components) ground for 1-2 h, and stir at 300-400 rpm for 48-72 h to obtain Homogeneous electrolyte slurry.

Casting of electrolyte slurry: Under anhydrous and oxygen-free conditions, the electrolyte slurry is first subjected to static defoaming treatment for 20 to 30 minutes, and then Teflon mold is used to cast the electrolyte slurry. Dry at ~70°C for at least 24h; the obtained polymer electrolyte is referred to as MSPE-4.

Example 5

As a reference sample, we prepared an unmodified PEO all-solid-state polymer electrolyte with EO:Li=16; the specific implementation process is as follows:

1) In an argon-filled glove box (H ₂ O <0.1ppm, O ₂ <0.5ppm), 1.361g PEO and 0.556g LiTFSI were dissolved in a mixed solvent of 25mL tetrahydrofuran and 5mL acetonitrile, and the mixture was heated at room temperature for 300 Stir at ~400rpm for 12~18h to obtain a uniform electrolyte slurry.

2) Casting and molding of electrolyte slurry: Under anhydrous and oxygen-free conditions, the electrolyte slurry is first subjected to a static defoaming treatment for 20-30 minutes, and then a Teflon mold is used to cast the electrolyte slurry, and the temperature is respectively 20-30 ° C. And 50～70 ℃ of drying for at least 24h; the obtained polymer electrolyte is called SPE-PEO for short.

Example 6

The preparation of an all-solid-state polymer electrolyte modified with cross-linked organic nanomaterials HCPs-1 and EO:Li=20 includes the following steps:

1) the preparation of mPEO-Br macromolecular initiator: the concrete method is the same as the step 1 of embodiment 1);

2) Preparation of PEO-PS diblock copolymer: the specific method is the same as step 2 in Example 1);

3) Preparation of cross-linked organic nanomaterial HCPs-1: the specific method is the same as step 3 of Example 1);

4) Preparation of cross-linked organic nanomaterial modified all-solid polymer electrolyte 5:

Preparation of electrolyte slurry: In an argon-filled glove box (H ₂ O <0.1 ppm, O ₂ <0.5 ppm), 1.3 g PEO and 0.425 g LiTFSI were dissolved in a mixed solvent of 25 mL tetrahydrofuran and 5 mL acetonitrile, and Stir at room temperature at 300-400 rpm for 12-18 h; then add 0.192 g of cross-linked organic nanomaterial HCPs-1 (accounting for 10 wt% of all solid components) ground for 1-2 h, and stir at 300-400 rpm for 48-72 h to obtain Homogeneous electrolyte slurry;

Casting of electrolyte slurry: Under anhydrous and oxygen-free conditions, the electrolyte slurry is first subjected to static defoaming treatment for 20 to 30 minutes, and then Teflon mold is used to cast the electrolyte slurry. Dry at ~70°C for at least 24h; the obtained polymer electrolyte is referred to as MSPE-5 for short.

Example 7

The preparation of an all-solid polymer electrolyte modified with cross-linked organic nanomaterials HCPs-2 and EO:Li=20 includes the following steps:

1) the preparation of mPEO-Br macromolecular initiator: the concrete method is the same as the step 1 of embodiment 1);

2) Preparation of PEO-PS diblock copolymer: the specific method is the same as step 2 in Example 1);

3) Preparation of cross-linked organic nanomaterial HCPs-2: the specific method is the same as step 3 of Example 2);

4) Preparation of cross-linked organic nanomaterial modified all-solid polymer electrolyte 6:

Preparation of electrolyte slurry: In an argon-filled glove box (H ₂ O <0.1 ppm, O ₂ <0.5 ppm), 1.3 g PEO and 0.425 g LiTFSI were dissolved in a mixed solvent of 25 mL tetrahydrofuran and 5 mL acetonitrile, and Stir at room temperature at 300-400rpm for 12-18h; then add 0.192g of cross-linked organic nanomaterial HCPs-2 (accounting for 10wt% of all solid components) ground for 1-2h, and stir at 300-400rpm for 48-72h to obtain Homogeneous electrolyte slurry;

Casting of electrolyte slurry: Under anhydrous and oxygen-free conditions, the electrolyte slurry is first subjected to static defoaming treatment for 20 to 30 minutes, and then Teflon mold is used to cast the electrolyte slurry. Dry at ~70°C for at least 24h; the obtained polymer electrolyte is referred to as MSPE-6.

Example 8

The preparation of an all-solid-state polymer electrolyte modified with cross-linked organic nanomaterials HCPs-3 and EO:Li=20 includes the following steps:

1) the preparation of mPEO-Br macromolecular initiator: the concrete method is the same as the step 1 of embodiment 1);

2) Preparation of PEO-PS diblock copolymer: the specific method is the same as step 2 in Example 1);

3) Preparation of cross-linked organic nanomaterial HCPs-3: the specific method is the same as step 3 of Example 2);

4) Preparation of cross-linked organic nanomaterial modified all-solid polymer electrolyte 7:

Preparation of electrolyte slurry: In an argon-filled glove box (H ₂ O <0.1 ppm, O ₂ <0.5 ppm), 1.3 g PEO and 0.425 g LiTFSI were dissolved in a mixed solvent of 25 mL tetrahydrofuran and 5 mL acetonitrile, and Stir at 300-400 rpm for 12-18 h at room temperature; then add 0.192 g of cross-linked organic nanomaterial HCPs-3 (accounting for 10 wt % of all solid components) ground for 1-2 h, and stir at 300-400 rpm for 48-72 h to obtain Homogeneous electrolyte slurry.

Casting of electrolyte slurry: Under anhydrous and oxygen-free conditions, the electrolyte slurry is first subjected to static defoaming treatment for 20 to 30 minutes, and then Teflon mold is used to cast the electrolyte slurry. Dry at ~70°C for at least 24h; the obtained polymer electrolyte is referred to as MSPE-7 for short.

Example 9

The preparation of an all-solid polymer electrolyte modified with cross-linked organic nanomaterials HCPs-4 and EO:Li=20 includes the following steps:

1) the preparation of mPEO-Br macromolecular initiator: the concrete method is the same as the step 1 of embodiment 1);

2) Preparation of PEO-PS diblock copolymer: the specific method is the same as step 2 in Example 1);

3) Preparation of cross-linked organic nanomaterial HCPs-4: the specific method is the same as step 3 of Example 2);

4) Preparation of cross-linked organic nanomaterial modified all-solid polymer electrolyte 8:

Preparation of electrolyte slurry: In an argon-filled glove box (H ₂ O <0.1 ppm, O ₂ <0.5 ppm), 1.3 g PEO and 0.425 g LiTFSI were dissolved in a mixed solvent of 25 mL tetrahydrofuran and 5 mL acetonitrile, and Stir at room temperature at 300-400 rpm for 12-18 h; then add 0.192 g of cross-linked organic nanomaterial HCPs-4 (accounting for 10 wt% of all solid components) ground for 1-2 h, and stir at 300-400 rpm for 48-72 h to obtain Homogeneous electrolyte slurry;

Casting of electrolyte slurry: Under anhydrous and oxygen-free conditions, the electrolyte slurry is first subjected to static defoaming treatment for 20 to 30 minutes, and then Teflon mold is used to cast the electrolyte slurry. Dry at ~70°C for at least 24h; the obtained polymer electrolyte is referred to as MSPE-8 for short.

Table 1 Test results of ionic conductivity of polymer electrolytes in groups 1-5 of Example 1 at different temperatures

In addition, the SEM characterizations of the cross-linked organic nanomaterials used in Examples 1-4 and 6-9 were carried out respectively. The results are shown in Figure 1. It can be seen from a-f that due to the formation of the cross-linked network, the polymerization A certain amount of adhesion occurred between the nanoparticles.

The electrochemical AC impedance spectra of Examples 1-5 at different test temperatures were tested respectively, wherein the test results of MSPE-2 and comparative sample SPE-PEO in Examples 2 and 5 are shown in Figure 3; The ionic conductivity values in Table 1 are obtained by calculation.

The linear sweep voltammograms (LSV) of Examples 1-5 are shown in Figure 4; it can be seen from the figure that the oxidative decomposition voltage values of Examples 1-4 are all close to 5V, with a wide electrochemical The stability window is significantly improved compared with the control sample.

The all-solid polymer electrolyte MSPE-2 of Example 2 was assembled into a Li/MSPE-2/LiFePO ₄ coin cell, and the rate and cycle performance test curves at 50 °C are shown in Figure 5; from Figure (a) The middle curve analysis shows that MSPE-2 exhibits good charge-discharge performance at different rates. From the curve analysis in Figure (b), it can be seen that MSPE-2 has an initial discharge ratio higher than 145mAh/g at 0.1C capacity, showing good cycling stability.

Claims (21)

1. an all-solid polymer electrolyte, characterized in that the composition of the all-solid polymer electrolyte comprises: a polymer with lithium ion transport properties, a lithium salt and an organic filler, and the organic filler is a diblock copolymer The cross-linked organic nanomaterial obtained by free-template self-assembly through Friedel-Crafts reaction; and the first component of the diblock copolymer is one of polyethylene oxide or polypropylene oxide; the second component is Polystyrene or polymers of styrene-derived monomers without strong electron withdrawing groups. 2. all-solid polymer electrolyte according to claim 1, is characterized in that, in described all-solid polymer electrolyte, the mol ratio of polymer with lithium ion transport performance and lithium salt satisfies: M:Li=10～ 20. The mass fraction of the organic filler in the electrolyte is 5-30%; wherein M is a structural unit that interacts with lithium salts in the polymer with lithium ion transport properties. 3. The all-solid-state polymer electrolyte according to claim 1 or 2, wherein the method for the cross-linked organic nanomaterials obtained by carrying out template-free self-assembly of the diblock copolymer by Friedel-Crafts reaction is: Under anhydrous and oxygen-free conditions, the cross-linked organic nano-fillers are obtained by Friedel-Crafts alkylation with diblock copolymers as raw materials under the action of catalysts, cross-linking agents and solvents; among which, the cross-linking agent accounts for The volume fraction of the total volume of the crosslinking agent and the solvent is: 0% to 90%. 4 . The all-solid polymer electrolyte according to claim 3 , wherein the volume fraction of the cross-linking agent in the total volume of the cross-linking agent and the solvent is 50% to 90%. 5 . 5. The all-solid polymer electrolyte according to claim 3, characterized in that, The crosslinking agent is selected from: dimethoxymethane or ethylene glycol dimethyl ether; The catalyst is selected from: at least one of FeCl ₃ , AlCl ₃ , BF ₃ , H ₂ SO ₄ , SnCl ₄ or ZnCl ₂ ; The solvent is selected from at least one of 1,2-dichloroethane or dichloromethane. 6. The all-solid polymer electrolyte according to claim 3, characterized in that, The Friedel-Crafts alkylation reaction process is as follows: adding the diblock copolymer and the catalyst to the solvent and the cross-linking agent, stirring to make the components evenly dispersed; then refluxing the reaction at 25-80 °C for 24-25 h; After the reaction, ethanol was added, ultrasonic dispersion and suction filtration were performed to obtain the product; then the product was washed with methanol and dilute hydrochloric acid in turn, and finally extracted with methanol for 48-72 h, collected and dried in vacuum to obtain cross-linked organic nanofillers. 7 . The all-solid polymer electrolyte according to claim 1 or 2 , wherein the electrochemical window of the all-solid polymer electrolyte reaches 4.8-5.0 V. 8 . 8. The all-solid polymer electrolyte according to claim 1 or 2, wherein the polymer with lithium ion transport properties is selected from the group consisting of: polyether polymers, polyacrylates, polyacrylonitrile or One of the polyvinylidene fluoride; The lithium salt is selected from: lithium perchlorate, lithium hexafluoroarsenate, lithium tetrafluoroborate, lithium hexafluorophosphate, lithium bis(trifluoromethanesulfonyl)imide, lithium bisfluorosulfonimide, and lithium trifluoromethanesulfonate At least one of lithium oxalate, lithium bis-oxalate borate or lithium difluorooxalate borate. 9. The all-solid polymer electrolyte according to claim 8, wherein the polymer with lithium ion transport properties is selected from the group consisting of: polyethylene oxide, polymethyl methacrylate, polyacrylonitrile, polyvinylidene fluoride At least one of ethylene or polyvinylidene fluoride-hexafluoropropylene copolymer. 10 . The preparation method of the all-solid polymer electrolyte according to claim 1 , wherein the preparation method comprises a solution casting method or a fusion hot pressing method. 11 . 11. The method for preparing an all-solid polymer electrolyte according to claim 10, wherein the solution casting method is: firstly stirring and mixing a polymer with lithium ion transport properties, a lithium salt, a solvent and an organic filler The electrolyte slurry is obtained; then the obtained electrolyte slurry is formed by casting and drying to obtain the all-solid polymer electrolyte. 12. The preparation method of all-solid polymer electrolyte according to claim 11, wherein the solution casting method comprises the following steps: 1) Preparation of electrolyte slurry: In an argon-filled glove box, add a polymer with lithium ion transport properties and a lithium salt into the solvent, and stir at room temperature; then add organic filler and continue stirring until the dispersion is uniform , to obtain electrolyte slurry; 2) Casting of the electrolyte slurry: under anhydrous and oxygen-free conditions, the electrolyte slurry is degassed and then cast with a Teflon mold, and then dried to obtain a polymer electrolyte membrane; and placed in a glove box medium spare. 13. The method for preparing an all-solid polymer electrolyte according to claim 12, wherein in step 1), the solvent is selected from the group consisting of: acetonitrile, N,N-dimethylformamide, acetone, dichloromethane or at least one of tetrahydrofuran. 14. The method for preparing an all-solid polymer electrolyte according to claim 13, wherein in step 1), the solvent is a mixed solvent in which acetonitrile and tetrahydrofuran are mixed in a volume ratio of 1:8 to 1:4. 15. The preparation method of an all-solid polymer electrolyte according to claim 14, wherein in step 1), the solvent is a mixed solvent of acetonitrile and tetrahydrofuran in a volume ratio of 1:5. 16. The preparation method of an all-solid polymer electrolyte according to claim 12, wherein in step 1), the molar ratio of the polymer with lithium ion transport performance to the lithium salt satisfies: M:Li=10～20 , where M is a structural unit that interacts with lithium salts in the polymer with lithium ion transport properties. 17. The method for preparing an all-solid polymer electrolyte according to claim 12, wherein in step 1), the organic filler needs to be ground for 1-2 h before adding; the stirring speed after adding is 300-400 rpm; The stirring time was 48-72 h to obtain a uniform electrolyte slurry. 18 . The method for preparing an all-solid polymer electrolyte according to claim 12 , wherein in step 2), the electrolyte slurry is subjected to defoaming treatment by standing for 20-30 min. 19 . 19 . The method for preparing an all-solid polymer electrolyte according to claim 12 , wherein in step 2), the drying conditions are as follows: 24-30 ℃ at temperatures of 20-30 ℃ and 50-70 ℃, respectively. 20 . The polymer electrolyte membrane can be obtained after the drying of h. 20. The application of a diblock copolymer in an all-solid polymer electrolyte, wherein the application method is: performing template-free self-assembly of the diblock copolymer through a Friedel-Crafts reaction to obtain a cross-linked organic nanomaterial, The obtained cross-linked organic nano-filler, polymer with lithium ion transport properties and lithium salt are used to obtain all-solid polymer electrolyte by solution casting method or melt hot pressing method; Wherein, the first component of the two-block copolymer is one of polyethylene oxide or polypropylene oxide; the second component is polystyrene or a styrene-derived monomer containing no strong electron withdrawing group. polymer. 21. the application of the diblock copolymer according to claim 20 in the all-solid polymer electrolyte, it is characterized in that, the mol ratio of the polymer with lithium ion transport performance and lithium salt satisfies: M:Li=10～ 20. The mass fraction of the cross-linked organic nanomaterial in the electrolyte is 5-30%; wherein M is a structural unit that interacts with lithium salts in the polymer with lithium ion transport properties.

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