A graft polymer solid electrolyte based on polyvinyl alcohol or polyvinyl alcohol-polyvinyl acetate copolymer and a preparation method thereof
The polymer solid electrolyte prepared through graft polymerization solves the balance of conduction lithium ions and mechanical strength, and achieves high conductivity and high stability battery performance.
Patent Information
- Application Number
- CN202210205378.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-03-02
- Publication Date
- 2025-07-29
- Estimated Expiration
- 2042-03-02
AI Technical Summary
The existing polymer solid electrolytes are difficult to balance between conducting lithium ion properties and mechanical strength, resulting in insufficient battery cycle stability at room temperature.
The graft polymer solid electrolyte is prepared by graft polymerization reaction with polyester or polycarbonate, and the molecular weight and reaction time are controlled to regulate flexibility and mechanical strength.
The balance between polymer chain flexibility and mechanical strength is achieved, the conductivity and electrochemical stability at room temperature is improved, and the cycle stability and specific capacity of the battery are enhanced.
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Figure CN114725497B_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of new energy, and particularly relates to a graft polymer solid electrolyte based on polyvinyl alcohol or polyvinyl alcohol-polyvinyl acetate copolymer and a preparation method thereof. Background Art
[0002] In recent years, with the rise of new energy, corresponding portable electronic products, electric vehicles and other electronic devices have also developed rapidly. Electrolytes are widely used in batteries and other electronic devices, acting as a medium for ion transport between the positive and negative electrodes. However, due to limitations in safety and energy density, the development of traditional liquid electrolyte batteries is restricted. Liquid electrolytes have properties such as easy leakage, low flash point, volatility, and toxicity. The safety and reliability of liquid lithium-ion batteries are poor. In the case of extrusion, collision, overcharging or certain accidents, they are prone to explosion and combustion problems, even endangering personal safety. Therefore, solid electrolyte batteries have become a new research direction. In terms of safety, solid electrolytes do not have serious safety problems caused by electrolyte leakage; in terms of energy density, solid electrolytes can suppress lithium dendrites due to their high mechanical strength and are applicable to lithium metal anodes with high energy density. Since the preparation process of polymer solid electrolytes is mature and can achieve safer, greener and more efficient industrialization, they are a quite promising type of solid electrolytes.
[0003] Since the solid electrolyte replaces the liquid electrolyte, compared with liquid lithium-ion batteries, polymer lithium-ion batteries have the advantages of being able to be thinned, having any area and any shape, and will not have safety problems such as liquid leakage and combustion explosion. Therefore, the battery shell can be made of aluminum-plastic composite film, thereby improving the specific capacity of the entire battery; polymer lithium-ion batteries can also use polymers as the positive electrode material, and their mass specific energy will be increased by more than 50% compared with current liquid lithium-ion batteries.
[0004] Existing research has shown that polycarbonate is a promising polymer solid electrolyte. On the basis of having a high ion transference number, it also has higher electrochemical stability (>4.2V) compared with ether-based polymer solid electrolytes. However, due to the strong molecular rigidity and low molecular flexibility of polyester-based polymer solid electrolytes, their ability to transport lithium ions is greatly reduced, and they cannot provide a suitable ionic conductivity at room temperature. And how to balance the mechanical strength and the performance of conducting lithium ions has become a problem to be solved at present.
[0005] So far, some researchers have tried to prepare polymer solid electrolytes based on polycaprolactone. For example, Patent CN111430791A discloses a method for preparing an in-situ polymerized polycaprolactone-based all-solid-state electrolyte. The all-solid-state electrolyte provided by this invention has high mechanical strength, a wide electrochemical stability window, high ionic conductivity, and a high ion transference number at the same time. The in-situ polymerization method makes the connection between the electrode and the electrolyte tight, reduces the interfacial impedance, and improves the battery cycle stability. However, even though it has achieved high ionic conductivity, it still cannot achieve battery cycling at room temperature. Therefore, it is particularly important to further improve the flexibility of the polymer chain segments to make it easier to conduct lithium ions and thus achieve room-temperature battery cycling. Summary of the Invention
[0006] To solve the deficiencies of the prior art, the purpose of the present invention is to provide a lithium-ion battery polymer solid electrolyte based on a graft polymer of polyvinyl alcohol or a polyvinyl alcohol-polyvinyl acetate copolymer and a preparation method thereof. Grafting a polyester or a polycarbonate onto polyvinyl alcohol or a polyvinyl alcohol-polyvinyl acetate copolymer can improve the ionic conductivity of the polyester, and can also regulate its molecular weight and provide mechanical strength, thereby increasing the cycle stability.
[0007] To achieve the above purpose, the present invention adopts the following technical solutions:
[0008] The present invention provides a method for preparing a graft polymer solid electrolyte based on polyvinyl alcohol or a polyvinyl alcohol-polyvinyl acetate copolymer, and the specific steps are as follows:
[0009] (1) Dissolve polyvinyl alcohol or a polyvinyl alcohol-polyvinyl acetate copolymer in an ester or carbonate molecule, and stir under anhydrous and anaerobic conditions to obtain a solution;
[0010] (2) Add a catalyst and react under anhydrous and anaerobic conditions;
[0011] (3) Wash with methanol and dry to obtain a graft copolymer, namely a polyvinyl alcohol-grafted polyester polymer, a polyvinyl alcohol-polyvinyl acetate copolymer-grafted polyester polymer, a polyvinyl alcohol-grafted polycarbonate polymer, or a polyvinyl alcohol-polyvinyl acetate copolymer-grafted polycarbonate polymer;
[0012] (4) Dissolve the graft polymer obtained in step (3) and a lithium salt in tetrahydrofuran, form a film by casting method, and dry in vacuum to obtain the polymer solid electrolyte.
[0013] Furthermore, the ester or carbonate molecule in step (1) includes at least one of polybutyrolactone, polycaprolactone, polyglycolide, polylactide, poly(ethylene carbonate), poly(fluorinated ethylene carbonate), poly(propylene carbonate), poly(trimethylene carbonate), poly(2,2-dimethyltrimethylene carbonate).
[0014] Further, the monomer of the ester or carbonate molecule in step (1) is a cyclic ester or cyclic carbonate monomer, including at least one of butyrolactone, caprolactone, glycolide, lactide, ethylene carbonate, fluoroethylene carbonate, propylene carbonate, trimethylene carbonate, 2,2-dimethyltrimethylene carbonate.
[0015] Further, the dosage ratio of the polyvinyl alcohol or polyvinyl alcohol-polyvinyl acetate copolymer to the ester or carbonate molecule in step (1) is 1 g / 10 mL to 10 g / mL.
[0016] Further, the temperature of the stirring in step (1) is 50 to 100 °C, and the stirring time is 3 to 6 h.
[0017] Further, the catalyst in step (2) is selected from at least one of triethylenediamine, pentamethyldiethylenetriamine, tris(2-dimethylaminoethyl)amine, (-)-sparteine, 1,5-diazabicyclo[4.3.0]non-5-ene, 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, tetramethylguanidine, N-beta-aminoethyl-gamma-aminopropylmethyldimethoxysilane.
[0018] Further, the mass ratio of the catalyst to the polyvinyl alcohol or polyvinyl alcohol-polyvinyl acetate copolymer in step (2) is 1:0.5 to 1:2.
[0019] Further, the temperature of the reaction in step (2) is 50 to 100 °C, and the reaction time is 12 to 36 h.
[0020] Further, the number of times of washing with methanol in step (3) is 3 to 5 times.
[0021] Further, the drying temperature in step (3) is 50 to 90 °C, and the drying time is 12 to 36 h.
[0022] Further, the lithium salt in step (4) is selected from at least one of lithium perchlorate, lithium hexafluorophosphate, lithium bis(oxalato)borate, lithium hexafluorophosphate, lithium tetrafluoroborate, lithium methanesulfonate, lithium trifluoromethanesulfonate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide.
[0023] Further, the weight ratio of the graft polymer to the lithium salt in step (4) is (20 - 90):(5 - 90).
[0024] Further, the dosage ratio of the graft polymer to tetrahydrofuran in step (4) is 1 g:5 mL to 1 g:50 mL.
[0025] Further, the temperature of the vacuum drying in step (4) is 50 - 90 °C, and the time is 12 - 36 h.
[0026] The present invention provides a graft polymer solid electrolyte based on polyvinyl alcohol or polyvinyl alcohol - polyvinyl acetate copolymer obtained by the above - mentioned preparation method.
[0027] The main chain of the graft polymer is the -(CH-CH2)- structure provided by polyvinyl alcohol or polyvinyl alcohol - polyvinyl acetate copolymer, and the molecular weight of the main chain is 1×10 n - 1×10 3 -; the side chains are composed of polyester - type or polycarbonate - type polymer chains, the degree of polymerization of the side chains is 1 - 50, and the side chains are connected to the main chain by covalent bonds. 6 The molecular weight of the graft polymer can be regulated by controlling the molecular weight of polyvinyl alcohol or polyvinyl alcohol - polyvinyl acetate copolymer and the reaction time of graft polymerization.
[0028] Compared with the prior art, the present invention has the following advantages and beneficial effects:
[0029] (1) In the present invention, polyvinyl alcohol or polyvinyl alcohol - polyvinyl acetate copolymer is grafted with polyester - type or polycarbonate - type polymer through ring - opening polymerization. The molecular weight of the target polymer is controlled by controlling the initial molecular weight of polyvinyl alcohol or polyvinyl alcohol - polyvinyl acetate copolymer and the graft reaction time, and the polymer and lithium salt are used as raw materials to prepare a solid electrolyte;
[0030] (2) The electrolyte prepared by the present invention is a branched - chain polymer with high molecular chain flexibility and a low glass transition temperature. The prepared solid electrolyte has a smooth surface, low interfacial impedance, and can have a higher conductivity, especially can achieve stable battery cycling at room temperature;
[0031] (3) The electrolyte prepared by the present invention uses an ester - bond polymer with good high - voltage resistance, can have a higher electrochemical window, and then load a more active cathode to achieve a higher specific capacity;
[0032] (4) The electrolyte prepared by the present invention can control the mechanical strength of the solid electrolyte by controlling the molecular weight;
[0033] (5) The polymer prepared by the present invention has a large number of side chains with hydroxyl groups at the ends, and other possible performance requirements can be achieved by reacting to change the end groups in the future.
[0034] (5) The polymer prepared by the present invention has a large number of side chains with hydroxyl groups at the ends, and other possible performance requirements can be achieved by reacting to change the end groups in the future. Description of the Drawings
[0035] Figure 1 and Figure 2SEM image of the solid electrolyte membrane based on the graft polymer PVA-g-PCL prepared in Example 1;
[0036] Figure 3 Impedance diagrams of the graft polymer PVA-g-PCL prepared in Example 1 at different temperatures;
[0037] Figure 4 I~E diagram of the electrochemical window of the solid electrolyte membrane based on the graft polymer PVA-g-PCL prepared in Example 1. Detailed implementation manners
[0038] The present invention will be further described in detail below with reference to the embodiments, but the implementation manners and the protection scope of the present invention are not limited thereto.
[0039] Example 1
[0040] A preparation method of a graft polymer PVA-g-PCL solid electrolyte based on polyvinyl alcohol grafted with polycaprolactone includes the following steps:
[0041] (1) Add 1 g of polyvinyl alcohol (Mw = 1×10 3 ) to 10 mL of caprolactone and stir at 50 °C for 6 h.
[0042] (2) Add 0.7 g of the catalyst 1,5-diazabicyclo in the solution and react at 50 °C for 12 h under anaerobic and anhydrous conditions.
[0043] (3) Wash 5 times with methanol, filter off the excess solvent, place the viscous sample in an oven and vacuum dry at 60 °C for 12 h to obtain PVA-g-PCL solid.
[0044] (4) Dissolve 0.1 g of PVA-g-PCL and 0.2 g of lithium bis(fluorosulfonyl)imide in 0.5 mL of tetrahydrofuran, introduce the solution into a polytetrafluoroethylene mold and vacuum dry at 60 °C for 12 h to obtain a solid electrolyte membrane based on the graft polymer PVA-g-PCL.
[0045] Figure 1 and Figure 2 SEM image of the PVA-g-PCL solid electrolyte membrane prepared in this example coated on a steel sheet, Figure 1 It can be seen that the white part on the right is the steel sheet, the black part on the left is the electrolyte, and the impurity particles are a small amount of inorganic particles added before the test to distinguish the electrolyte. The solid electrolyte membrane prepared by this method is very smooth and flat, has a small interfacial impedance and a high conductivity. Figure 3 Impedance diagram of the PVA-g-PCL solid electrolyte membrane prepared in this example at different temperatures, and the conductivity at room temperature is 1.91×10 -4 S / cm.Figure 4 I - E diagram of the electrochemical window of the PVA-g-PCL solid electrolyte membrane prepared in this example. The electrochemical stability window is 4.72 V.
[0046] Example 2
[0047] A preparation method of a graft polymer PVA-g-PEC solid electrolyte based on polyvinyl alcohol grafted with poly(ethylene carbonate) includes the following steps:
[0048] (1) Add 1 g of polyvinyl alcohol (Mw = 1×10 4 ) to 10 mL of ethylene carbonate and stir at 100 °C for 6 h.
[0049] (2) Add 0.5 g of catalytic triethylenediamine to the solution and react at 100 °C for 24 h under anaerobic and anhydrous conditions.
[0050] (3) Wash 5 times with methanol, filter off the excess solvent, place the viscous sample in an oven, and vacuum dry at 60 °C for 12 h to obtain PVA-g-PEC solid.
[0051] (4) Dissolve 0.1 g of PVA-g-PEC and 0.2 g of lithium methanesulfonate in 1 mL of tetrahydrofuran, introduce the solution into a polytetrafluoroethylene mold, and vacuum dry at 60 °C for 12 h to obtain a polymer solid electrolyte membrane based on the graft polymer PVA-g-PEC.
[0052] The room temperature conductivity of the polymer solid electrolyte membrane obtained in this example is 1.71×10 -4 S / cm, and the electrochemical stability window is 4.75 V.
[0053] Example 3
[0054] A preparation method of a graft poly(butyrolactone) graft polymer (PVA-c-PVAc)-g-PBL solid electrolyte based on a polyvinyl alcohol-poly(vinyl acetate) copolymer includes the following steps:
[0055] (1) Add 1 g of polyvinyl alcohol-poly(vinyl acetate) copolymer (Mw = 1×10 4 ) to 10 mL of butyrolactone and stir at 50 °C for 3 h.
[0056] (2) Add 0.9 g of catalyst pentamethyldiethylenetriamine to the solution and react at 60 °C for 36 h under anaerobic and anhydrous conditions.
[0057] (3) Wash 5 times with methanol, filter off the excess solvent, place the viscous sample in an oven, and vacuum dry at 60 °C for 12 h to obtain (PVA-c-PVAc)-g-PBL solid.
[0058] (4) Dissolve 0.1 g of (PVA-c-PVAc)-g-PBL and 0.2 g of lithium tetrafluoroborate in 0.5 mL of tetrahydrofuran. Introduce the solution into a polytetrafluoroethylene mold and dry it under vacuum at 90 °C for 36 h to obtain a polymer solid electrolyte membrane based on the graft polymer (PVA-c-PVAc)-g-PBL.
[0059] The room temperature conductivity of the polymer solid electrolyte membrane obtained in this example is 1.88×10 -4 S / cm, and the electrochemical stability window is 4.67 V.
[0060] Example 4
[0061] A preparation method of a graft polymer (PVA-c-PVAc)-g-PPC solid electrolyte based on a polyvinyl alcohol-polyvinyl acetate copolymer grafted with polypropylene carbonate, comprising the following steps:
[0062] (1) Add 1 g of polyvinyl alcohol-polyvinyl acetate copolymer (Mw = 1×10 5 ) to 10 mL of propylene carbonate and stir at 70 °C for 3 h.
[0063] (2) Add 0.3 g each of the catalysts tris(2-dimethylaminoethyl)amine and N-BETA-aminoethyl-GAMMA-aminopropylmethyldimethoxysilane to the solution, and react at 50 °C for 12 h under anaerobic and anhydrous conditions.
[0064] (3) Wash 3 times with methanol, filter off the excess solvent, place the viscous sample in an oven, and dry it under vacuum at 60 °C for 12 h to obtain (PVA-c-PVAc)-g-PPC solid.
[0065] (4) Dissolve 0.1 g of (PVA-c-PVAc)-g-PPC and 1.8 g of lithium hexafluorophosphate in 5 mL of tetrahydrofuran. Introduce the solution into a polytetrafluoroethylene mold and dry it under vacuum at 50 °C for 20 h to obtain a polymer solid electrolyte membrane based on the graft polymer (PVA-c-PVAc)-g-PPC.
[0066] The room temperature conductivity of the polymer solid electrolyte membrane obtained in this example is 1.91×10 -4 S / cm, and the electrochemical stability window is 4.73 V.
[0067] Example 5
[0068] A preparation method of a graft polymer (PVA-c-PVAc)-g-PGA solid electrolyte based on a polyvinyl alcohol polyvinyl acetate copolymer grafted with polyglycolide, comprising the following steps:
[0069] (1) Add 1 g of polyvinyl alcohol-polycarbonate (Mw = 1×106 (1) The copolymer was added to 10 mL of glycolide and stirred at 100 °C for 3 h.
[0070] (2) 2 g of the catalyst (-)-sparteine was added to the solution, and the reaction was carried out at 70 °C for 30 h under anaerobic and anhydrous conditions.
[0071] (3) It was washed 5 times with methanol, the excess solvent was filtered off, and the viscous-flow state sample was placed in an oven and vacuum dried at 60 °C for 12 h to obtain a (PVA-c-PVAc)-g-PGA solid.
[0072] (4) 0.1 g of (PVA-c-PVAc)-g-PGA and 0.45 g of lithium bis(oxalato)borate were dissolved in 3 mL of tetrahydrofuran, and the solution was introduced into a polytetrafluoroethylene mold and vacuum dried at 80 °C for 24 h to obtain a polymer solid electrolyte membrane based on the graft polymer (PVA-c-PVAc)-g-PGA.
[0073] The room temperature conductivity of the polymer solid electrolyte membrane obtained in this example was 1.80×10 -4 S / cm, and the electrochemical stability window was 4.70 V.
[0074] Example 6
[0075] A preparation method of a graft polymer (PVA-c-PVAc)-g-PGA solid electrolyte based on a polyvinyl alcohol-polyvinyl acetate copolymer grafted with polyglycolide, comprising the following steps:
[0076] (1) 10 g of a polyvinyl alcohol-polycarbonate vinyl copolymer (Mw = 1×10 6 ) copolymer was added to 10 mL of glycolide and stirred at 80 °C for 4.5 h.
[0077] (2) 5 g of the catalyst 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene was added to the solution, and the reaction was carried out at 70 °C for 20 h under anaerobic and anhydrous conditions.
[0078] (3) It was washed 4 times with methanol, the excess solvent was filtered off, and the viscous-flow state sample was placed in an oven and vacuum dried at 60 °C for 12 h to obtain a (PVA-c-PVAc)-g-PGA solid.
[0079] (4) 0.1 g of (PVA-c-PVAc)-g-PGA and 0.45 g of lithium hexafluorophosphate were dissolved in 0.6 mL of tetrahydrofuran, and the solution was introduced into a polytetrafluoroethylene mold and vacuum dried at 70 °C for 20 h to obtain a polymer solid electrolyte membrane based on the graft polymer (PVA-c-PVAc)-g-PGA.
[0080] The room temperature conductivity of the polymer solid electrolyte membrane obtained in this example was 1.82×10-4 S / cm, and the electrochemical stability window is 4.71 V.
[0081] Example 7
[0082] A preparation method of a graft polymer (PVA-c-PVAc)-g-PGA solid electrolyte based on polyvinyl alcohol-polyvinyl acetate copolymer grafted with polyglycolide, comprising the following steps:
[0083] (1) Add 5 g of polyvinyl alcohol-polycarbonate ethylene ester (Mw = 1×10 3 ) copolymer to 10 mL of glycolide, and stir at 70 °C for 6 h.
[0084] (2) Add 5 g of catalyst 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene to the solution, and react at 50 °C for 20 h under anaerobic and anhydrous conditions.
[0085] (3) Wash 3 times with methanol, filter off the excess solvent, place the viscous flow state sample in an oven, and vacuum dry at 75 °C for 18 h to obtain (PVA-c-PVAc)-g-PGA solid.
[0086] (4) Dissolve 0.2 g of (PVA-c-PVAc)-g-PGA and 0.9 g of lithium bis(oxalato)borate in 5 mL of tetrahydrofuran, introduce the solution into a polytetrafluoroethylene mold, and vacuum dry at 75 °C for 18 h to obtain a polymer solid electrolyte membrane based on the graft polymer (PVA-c-PVAc)-g-PGA.
[0087] The room temperature conductivity of the polymer solid electrolyte membrane obtained in this example is 1.82×10 -4 S / cm, and the electrochemical stability window is 4.71 V.
[0088] Example 8
[0089] A preparation method of a graft polymer (PVA-c-PVAc)-g-PGA solid electrolyte based on polyvinyl alcohol-polyvinyl acetate copolymer grafted with polyglycolide, comprising the following steps:
[0090] (1) Add 8 g of polyvinyl alcohol-polycarbonate ethylene ester (Mw = 3×10 3 ) copolymer to 10 mL of glycolide, and stir at 70 °C for 3 h.
[0091] (2) Add 12 g of catalyst 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene to the solution, and react at 65 °C for 12 h under anaerobic and anhydrous conditions.
[0092] (3) Wash it 4 times with methanol, filter off the excess solvent, place the viscous-flow sample in an oven, and vacuum-dry it at 50 °C for 36 h to obtain the (PVA-c-PVAc)-g-PGA solid.
[0093] (4) Dissolve 0.9 g of (PVA-c-PVAc)-g-PGA and 0.05 g of lithium methyl sulfonate in 5 mL of tetrahydrofuran. Introduce the solution into a polytetrafluoroethylene mold and vacuum-dry it at 60 °C for 36 h to obtain the polymer solid electrolyte membrane based on the graft polymer (PVA-c-PVAc)-g-PGA.
[0094] The room-temperature conductivity of the polymer solid electrolyte membrane obtained in this example is 1.82×10 -4 S / cm, and the electrochemical stability window is 4.71 V.
[0095] The above-described embodiments are only the preferred embodiments of the present invention. The embodiments of the present invention are not limited by the above embodiments. It should be noted that any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention should be equivalent replacement methods and are all included in the protection scope of the present invention.
Claims
1. A method for preparing a graft polymer solid electrolyte based on polyvinyl alcohol or polyvinyl alcohol-polyvinyl acetate copolymer, characterized in that, The specific steps are as follows: (1) Dissolve polyvinyl alcohol or polyvinyl alcohol-polyvinyl acetate copolymer in ester or carbonate molecules, and stir under anhydrous and anaerobic conditions to obtain a solution; (2) Add a catalyst and react under anhydrous and anaerobic conditions; (3) Wash with methanol and dry to obtain a graft copolymer, namely polyvinyl alcohol grafted polyester polymer, polyvinyl alcohol-polyvinyl acetate copolymer grafted polyester polymer, polyvinyl alcohol grafted polycarbonate polymer, or polyvinyl alcohol-polyvinyl acetate copolymer grafted polycarbonate polymer; (4) Dissolve the graft polymer obtained in step (3) and a lithium salt in tetrahydrofuran, form a film by casting method, and dry in vacuum to obtain the polymer solid electrolyte; The ester or carbonate molecules in step (1) include at least one of polybutyrolactone, polycaprolactone, polyglycolide, polylactide, poly(ethylene carbonate), poly(fluorinated ethylene carbonate), poly(propylene carbonate), poly(trimethylene carbonate), poly(2,2-dimethyltrimethylene carbonate); the dosage ratio of the polyvinyl alcohol or polyvinyl alcohol-polyvinyl acetate copolymer to the ester or carbonate molecules in step (1) is 1 g / 10 mL - 10 g / mL; the stirring temperature in step (1) is 50 - 100 °C, and the stirring time is 3 - 6 h; The main chain of the grafted polymer in step (3) is -(CH-CH2) provided by polyvinyl alcohol or polyvinyl alcohol-polyvinyl acetate copolymer. n -structure, the main chain molecular weight is 1×10 3 -1×10 6 ; The side chains are composed of polyester or polycarbonate polymer chains, the degree of polymerization of the side chains is 1-50, and the side chains are connected to the main chain through covalent bonds.
2. The preparation method of the graft polymer solid electrolyte based on polyvinyl alcohol or polyvinyl alcohol-polyvinyl acetate copolymer according to claim 1, characterized in that, The catalyst in step (2) is selected from at least one of triethylenediamine, pentamethyldiethylenetriamine, tris(2-dimethylaminoethyl)amine, (-)-sparteine, 1,5-diazabicyclo[4.3.0]non-5-ene, 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, tetramethylguanidine, N-beta-aminoethyl-gamma-aminopropylmethyldimethoxysilane.
3. The preparation method of the graft polymer solid electrolyte based on polyvinyl alcohol or polyvinyl alcohol-polyvinyl acetate copolymer according to claim 1, characterized in that, The mass ratio of the catalyst to the polyvinyl alcohol or polyvinyl alcohol-polyvinyl acetate copolymer in step (2) is 1:0.5 - 1:2; the reaction temperature in step (2) is 50 - 100 °C, and the reaction time is 12 - 36 h.
4. The preparation method of the graft polymer solid electrolyte based on polyvinyl alcohol or polyvinyl alcohol-polyvinyl acetate copolymer according to claim 1, characterized in that, The drying temperature in step (3) is 50 - 90 °C, and the drying time is 12 - 36 h.
5. The preparation method of the graft polymer solid electrolyte based on polyvinyl alcohol or polyvinyl alcohol-polyvinyl acetate copolymer according to claim 1, characterized in that, The lithium salt in step (4) is selected from at least one of lithium perchlorate, lithium hexafluorophosphate, lithium bis(oxalato)borate, lithium tetrafluoroborate, lithium methanesulfonate, lithium trifluoromethanesulfonate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide.
6. The preparation method of the graft polymer solid electrolyte based on polyvinyl alcohol or polyvinyl alcohol-polyvinyl acetate copolymer according to claim 1, characterized in that, The weight ratio of the graft polymer to the lithium salt in step (4) is (20 - 90):(5 - 90); the dosage ratio of the graft polymer to tetrahydrofuran in step (4) is 1 g:5 mL - 1 g:50 mL; the vacuum drying temperature in step (4) is 50 - 90 °C, and the time is 12 - 36 h.
7. A graft polymer solid electrolyte based on polyvinyl alcohol or polyvinyl alcohol-polyvinyl acetate copolymer obtained by the preparation method according to any one of claims 1 - 6.
Citation Information
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CN113527642A