A solid polymer electrolyte containing ionic liquid and preparation method thereof

Abstract

The present invention provides a solid polymer electrolyte containing an ionic liquid and a preparation method thereof, belonging to the technical field of solid polymer electrolytes. The electrolyte comprises a cross-linked polymer matrix, a lithium salt or sodium salt, and an ionic liquid. The structure of the cross-linked polymer matrix is ​​shown in Formula (I). The solid polymer electrolyte provided by the present invention is prepared through a curing reaction between amino and epoxy groups, resulting in solid polymer electrolytes with varying ether chain lengths and cross-linking degrees. The solid polymer electrolyte also contains a large number of hydrogen bonds, which can reduce the crystallinity of the PEO chain segments and further adjust the lithium or sodium ion transport properties and mechanical properties of the solid polymer electrolyte.

Description

Technical Field

[0001] The invention belongs to the technical field of solid polymer electrolytes and relates to a solid polymer electrolyte containing ionic liquid and a preparation method thereof. Background Art

[0002] Solid electrolytes are key materials for solid-state lithium batteries, and their performance determines the performance of solid-state batteries. Solid electrolytes are generally divided into inorganic solid electrolytes and solid polymer electrolytes. Compared with inorganic solid electrolytes, solid polymer electrolytes have better flexibility, processability and interface compatibility. The flexibility of polymer structure and the practicality of various lithium salts and additives provide more options for the design of solid polymer electrolytes. However, solid polymer electrolytes have low room temperature lithium ion conductivity (10 -7 -10 -6 S cm -1 ), its narrow electrochemical window and poor compatibility with the electrode interface restrict its large-scale application.

[0003] To improve the room-temperature ionic conductivity of solid polymer electrolytes, modifications are often required, such as incorporation of additives, blending, copolymerization, and crosslinking, to reduce the polymer's crystallinity and glass transition temperature. Ionic liquids have attracted widespread attention due to their high ionic conductivity, wide electrochemical window, excellent thermal stability, lack of vapor pressure, and non-flammability. To further enhance their mechanical properties and inhibit lithium dendrite growth, cross-linking is often employed. Preparing solid polymer electrolytes via in situ polymerization is a common approach to addressing interfacial issues with electrodes. Summary of the Invention

[0004] The purpose of the present invention is to provide a solid polymer electrolyte containing an ionic liquid and a preparation method thereof. The method can improve the electrical conductivity of the solid polymer electrolyte, broaden the electrochemical window, and at the same time improve problems such as poor compatibility between the solid polymer electrolyte and electrode materials. The preparation process of the solid polymer electrolyte provided by the present invention is simple, does not require the use of catalysts, organic solvents, or complex post-processing, is environmentally friendly, and is suitable for large-scale industrial production.

[0005] In order to achieve the above-mentioned purpose, the present invention adopts the following technical solutions:

[0006] The present invention provides a solid polymer electrolyte containing an ionic liquid, comprising a cross-linked polymer matrix, a lithium salt or a sodium salt, and an ionic liquid. The structure of the cross-linked polymer matrix is ​​shown in formula (I):

[0007]

[0008] wherein R comprises aliphatic chains or aromatic rings in different diamine monomers;

[0009] n is an integer from 4 to 113.

[0010] Preferably, the cross-linked polymer matrix is ​​prepared by in situ polymerization of polyethylene glycol diglycidyl ether and diamine monomers through nucleophilic addition reaction, wherein the diamine monomers include aliphatic diamine monomers and aromatic diamine monomers, and the aliphatic diamine monomers include NH2-(CH2) m -NH2 (m is an integer of 2 to 30) and aliphatic diamine monomers containing branches of different carbon chain lengths at different positions; aromatic diamine monomers include benzyl diamine, p-phenylenediamine, m-phenylenediamine, o-phenylenediamine, 2-methyl-1,4-phenylenediamine, 2-phenyl-1,4-phenylenediamine, 2-ethyl-1,4-phenylenediamine, 2-propyl-1,4-phenylenediamine, 2-isopropyl-1,4-phenylenediamine , 2-butyl-1,4-phenylenediamine, 2-isobutyl-1,4-phenylenediamine, 2-pentyl-1,4-phenylenediamine, 2-chloro-1,4-phenylenediamine, 2-bromo-1,4-phenylenediamine, 4,4-diphenylenediamine, 2,2'-dimethyl-4,4'-diphenylenediamine, 1,4-naphthalenediamine, 1,5-naphthalenediamine, 2,6-naphthalenediamine, 2-phenyl-p-phenylenediamine, 2-phenoxy-p-phenylenediamine;

[0011] The structure of polyethylene glycol diglycidyl ether (PEGDE) is shown in (II):

[0012]

[0013] Wherein, n is an integer of 4 to 113, and the relative molecular mass of polyethylene glycol in polyethylene glycol diglycidyl ether (PEGDE) is 200 to 5000.

[0014] Preferably, the lithium salt is one or more of lithium bis(trifluoromethanesulfonyl imide), lithium bis(fluorosulfonyl imide), lithium perchlorate, lithium difluorooxalatoborate, lithium hexafluorophosphate, and lithium tetrafluoroborate.

[0015] Preferably, the sodium salt is one or more of sodium hexafluorophosphate, sodium perchlorate, sodium trifluoromethanesulfonate, sodium bis(fluorosulfonyl)imide, and sodium bis(trifluoromethanesulfonyl)imide.

[0016] Preferably, the ionic liquid is one or more of imidazole, pyridine, piperidine and pyrrole ionic liquids.

[0017] Preferably, the imidazole ionic liquid is selected from 1-ethyl-3-methylimidazolium chloride, 1-ethyl-3-methylimidazolium bromide, 1-ethyl-3-methylimidazolium iodide, 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-ethyl-3-methylimidazolium hexafluorophosphate, 1-ethyl-3-methylimidazolium trifluoromethanesulfonyl imide, 1-ethyl-3-methylimidazolium bistrifluoromethanesulfonyl imide, 1-ethyl-3-methylimidazolium ethyl sulfate, 1-ethyl-3-methylimidazolium perchlorate, 1-ethyl-3-methylimidazolium p-toluenesulfonate, 1-propyl-3-methylimidazolium chloride, 1-propyl-3-methyl tetrafluoroborate, 1-propyl-3-methyl Imidazole hexafluorophosphate, 1-propyl-3-methylimidazolium trifluoromethanesulfonimide, 1-propyl-3-methylimidazolium bistrifluoromethanesulfonimide, 1-butyl-3-methylimidazolium chloride, 1-butyl-3-methylimidazolium bromide, 1-butyl-3-methylimidazolium iodide, 1-butyl-3-methylimidazolium nitrate, 1-butyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium hexafluorophosphate, 1-butyl-3-methylimidazolium methanesulfonate, 1-butyl-3-methylimidazolium p-toluenesulfonate, 1-butyl-3-methylimidazolium dihydrogenphosphate, 1-butyl-3-methylimidazolium thiocyanate, 1-butyl-3-methylimidazolium trifluoromethanesulfonyl Imidium salt, 1-butyl-3-methylimidazolium bistrifluoromethanesulfonyl imide salt, 1-butyl-3-methylimidazolium dicyanamide salt, 1-hexyl-3-methylimidazolium hexafluorophosphate, 1-octyl-3-methylimidazolium tetrafluorophosphate, 1-decyl-3-methylimidazolium perchlorate, 1-dodecane-3-methylimidazolium chloride, 1-dodecane-3-methylimidazolium tetrafluorophosphate, 1-dodecane-3-methylimidazolium hexafluorophosphate, 1-tetradecane-3-methylimidazolium bromide, 1-tetradecane-3-methylimidazolium hexafluorophosphate, 1-butyl-2,3-dimethylimidazolium bromide, 1-butyl-2,3-dimethylimidazolium hexafluorophosphate, 1-butyl-2,3- One or more of dimethylimidazole perchlorate, 1-butyl-2,3-dimethylimidazole tetrafluoroborate, 1-butyl-2,3-dimethylimidazole nitrate, 1-butyl-2,3-dimethylimidazole p-toluenesulfonate, 1-butyl-2,3-dimethylimidazole dihydrogenphosphate, 1-butyl-2,3-dimethylimidazole hydrogensulfate, 1-hexyl-2,3-dimethylimidazole tetrafluoroborate, 1-hexyl-2,3-dimethylimidazole chloride, 1-hexyl-2,3-dimethylimidazole hexafluorophosphate, 1-hexyl-2,3-dimethylimidazole perchlorate, 1-hexyl-2,3-dimethylimidazole bromide, and 1-sulfonic acid propyl-3-methylimidazole inner salt.

[0018] Preferably, the pyridine ionic liquid is one or more of N-ethylpyridine bis(trifluoromethanesulfonyl)imide, N-ethylpyridine hexafluorophosphate, N-ethylpyridine tetrafluoroborate, N-ethylpyridine perchlorate, N-ethylpyridine bromide, N-butylpyridine chloride, N-butylpyridine bromide, N-butylpyridine iodide, N-butylpyridine tetrafluoroborate, N-butylpyridine hexafluorophosphate, N-butylpyridine perchlorate, N-butylpyridine p-toluenesulfonate, N-butylpyridine bis(trifluoromethanesulfonyl)imide, N-hexylpyridine tetrafluoroborate, N-hexylpyridine hexafluorophosphate, N-hexylpyridine bis(trifluoromethanesulfonyl)imide, N-octylpyridine perchlorate, N-sulfonic acid propylpyridine hydrogen sulfate, N-sulfonic acid propyl-3-methylpyridine p-toluenesulfonate, and pyridinesulfonic acid propiolactone.

[0019] Preferably, the piperidine ionic liquid is one or more of N-propyl-N-methylpiperidinium chloride, N-propyl-N-methylpiperidinium bromide, N-propyl-N-methylpiperidinium iodide, N-propyl-N-methylpiperidinium perchlorate, N-propyl-N-methylpiperidinium trifluoromethanesulfonyl imide, N-propyl-N-methylpiperidinium bistrifluoromethanesulfonyl imide, and N-propyl-N-methylpiperidinium difluorooxalatoborate.

[0020] Preferably, the pyrrole ionic liquid is one or more of N-ethyl-N-methylpyrrolidine chloride, N-ethyl-N-methylpyrrolidine bromide, N-ethyl-N-methylpyrrolidine tetrafluoroborate, N-propyl-N-methylpyrrolidine trifluoromethanesulfonyl imide, N-propyl-N-methylpyrrolidine perchlorate, N-propyl-N-methylpyrrolidine tetrafluoroborate, N-propyl-N-methylpyrrolidine hexafluorophosphate, N-propyl-N-methylpyrrolidine bistrifluoromethanesulfonyl imide, N-butyl-N-methylpyrrolidine hexafluoroborate, N-butyl-N-methylpyrrolidine bromide, N-butyl-N-methylpyrrolidine bistrifluoromethanesulfonyl imide, N-butyl-N-methylpyrrolidine perchlorate, and N-butyl-N-methylpyrrolidine trifluoromethanesulfonate.

[0021] The present invention provides a method for preparing a solid polymer electrolyte containing an ionic liquid, comprising the following steps:

[0022] The polyethylene glycol diglycidyl ether is melted, and then lithium salt or sodium salt is added and stirred to dissolve, and then the ionic liquid is added and stirred to dissolve, and then the diamine monomer is added. After the dissolution is completed, the mixture is allowed to stand and degas to perform in-situ polymerization reaction to obtain a solid polymer electrolyte containing the ionic liquid.

[0023] Preferably, the molar ratio of the diamine monomer to polyethylene glycol diglycidyl ether is 1:(1-8); the molar ratio of the lithium ions or sodium ions in the lithium salt or sodium salt to the ether oxygen atoms in the polymer of formula (I) is 1:(2-128), and the content of the ionic liquid is 5-300wt% of the mass of the polymer electrolyte.

[0024] Preferably, the melting temperature of the polyethylene glycol diglycidyl ether is 25-80°C, the stirring and dissolving temperature of the lithium salt or sodium salt is 10-80°C, the stirring temperature of the ionic liquid is 0-60°C, and the time is 5 min-24 h. The dissolving temperature of the added diamine monomer is 10-80°C, the dissolving time is 3 min-48 h, the standing and degassing temperature is 5-40°C, and the standing and degassing time is 0.05-4 h.

[0025] Preferably, the temperature of the in-situ polymerization is 10-120° C., and the time is 2-72 hours.

[0026] The present invention also provides the use of the above-mentioned solid polymer electrolyte containing ionic liquid in lithium ion batteries or sodium ion batteries.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] (1) The solid polymer electrolyte provided by the present invention is prepared by the curing reaction of amino and epoxy groups, and a solid polymer electrolyte containing different ether chain lengths and cross-linking degrees can be obtained. At the same time, the solid polymer electrolyte contains a large number of hydrogen bonds, which can reduce the crystallinity of the PEO chain segment and further adjust the lithium ion transport performance and mechanical properties of the solid polymer electrolyte.

[0029] (2) Compared with the traditional PEO-based solid electrolyte, the solid polymer electrolyte provided by the present invention has an adjustable cross-linking degree, which reduces the crystallinity and glass transition temperature of the solid polymer electrolyte. At the same time, the addition of ionic liquids can reduce the crystallinity of the solid polymer electrolyte. Figure 4 As shown, the solid polymer electrolyte of Example 2 has no obvious crystallization peak, and the crystallinity is 3.76% (R = 0.82%) when fitted by the software JADE; Figure 2 As shown in FIG2 , the glass transition temperature of the solid polymer electrolyte of Example 2 is -30.05°C, which has a more excellent segment mobility, improves the lithium ion transmission capacity, and further improves the conductivity of the solid polymer electrolyte. The room temperature ionic conductivity is as high as 5.87×10 -4 S cm -1 .like Figure 9 As shown, the solid polymer electrolyte of Example 9 has no obvious crystallization peak, and the crystallinity is 2.15% (R = 0.25%) when fitted by the software JADE; Figure 8As shown in FIG1 , the glass transition temperature of the solid polymer electrolyte of Example 9 is -36.71°C. It has a more excellent segmental mobility, improves the sodium ion transport capacity, and further improves the conductivity of the solid polymer electrolyte. The room temperature ionic conductivity is as high as 7.53×10 -4 S cm -1 .

[0030] (3) The solid sodium ion polymer electrolyte provided by the present invention is prepared by an in situ polymerization method, which can effectively solve the problem of poor interface contact between the solid polymer electrolyte and the positive and negative electrodes, reduce the interface impedance, and further improve the lithium ion transport performance.

[0031] (4) Compared with traditional liquid electrolytes, the solid sodium ion polymer electrolyte provided by the present invention does not contain flammable organic solvents. At the same time, the addition of ionic liquids makes it have higher thermal stability and safety, and the thermal decomposition temperature reaches above 300°C.

[0032] (5) Ionic liquids themselves have high ionic conductivity, a wide electrochemical window, excellent thermal stability, no vapor pressure and are non-flammable. The solid polymer electrolyte provided by the present invention is doped with ionic liquid to improve the ionic conductivity of the solid polymer electrolyte, widen the electrochemical window, and increase the thermal stability of the solid polymer electrolyte.

[0033] (6) The preparation method of the solid sodium ion polymer electrolyte provided by the present invention is simple, the reaction conditions are mild, no catalyst is required, and no post-treatment is required. At the same time, the thickness of the solid sodium ion polymer electrolyte can be controlled by the volume of the added precursor solution, and it can be prepared into different shapes, which is suitable for industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a SEM surface image of the cross-linked solid polymer electrolyte described in Comparative Example 1.

[0035] Figure 2 This is the thermogravimetric curve of the cross-linked solid polymer electrolyte described in Example 2.

[0036] Figure 3 This is the differential scanning calorimetry test curve of the cross-linked solid polymer electrolyte described in Example 2.

[0037] Figure 4 This is the X-ray diffraction pattern of the cross-linked solid polymer electrolyte described in Example 2.

[0038] Figure 5 This is a curve showing the change in conductivity of the cross-linked solid polymer electrolyte described in Example 2 as a function of temperature.

[0039] Figure 6This is the electrochemical window test curve of the cross-linked solid polymer electrolyte described in Example 2.

[0040] Figure 7 This is the thermogravimetric curve of the solid sodium ion polymer electrolyte described in Example 9.

[0041] Figure 8 This is the differential scanning calorimetry test curve of the solid sodium ion polymer electrolyte described in Example 9.

[0042] Figure 9 This is the X-ray diffraction pattern of the solid sodium ion polymer electrolyte described in Example 9.

[0043] Figure 10 This is the impedance diagram of the solid sodium ion polymer electrolyte described in Example 9 at room temperature.

[0044] Figure 11 3 is a curve showing the change in electrical conductivity of the solid sodium ion polymer electrolyte as a function of temperature.

[0045] Figure 12 This is the electrochemical window test curve of the solid sodium ion polymer electrolyte described in Example 9. DETAILED DESCRIPTION

[0046] The present invention provides a solid polymer electrolyte containing an ionic liquid, comprising a cross-linked polymer matrix, a lithium salt or a sodium salt, and an ionic liquid. The structure of the cross-linked polymer matrix is ​​shown in formula (I):

[0047]

[0048] wherein R comprises aliphatic chains or aromatic rings in different diamine monomers;

[0049] n is an integer from 4 to 113.

[0050] The cross-linked polymer matrix is ​​prepared by in-situ polymerization of polyethylene glycol diglycidyl ether and diamine monomers through nucleophilic addition reaction, wherein the diamine monomers include aliphatic diamine monomers and aromatic diamine monomers, and the aliphatic diamine monomers include NH2-(CH2) m-NH2 (m is an integer of 2 to 30) and aliphatic diamine monomers containing branches of different carbon chain lengths at different positions; aromatic diamine monomers include benzyl diamine, p-phenylenediamine, m-phenylenediamine, o-phenylenediamine, 2-methyl-1,4-phenylenediamine, 2-phenyl-1,4-phenylenediamine, 2-ethyl-1,4-phenylenediamine, 2-propyl-1,4-phenylenediamine, 2-isopropyl-1,4-phenylenediamine , 2-butyl-1,4-phenylenediamine, 2-isobutyl-1,4-phenylenediamine, 2-pentyl-1,4-phenylenediamine, 2-chloro-1,4-phenylenediamine, 2-bromo-1,4-phenylenediamine, 4,4-diphenylenediamine, 2,2'-dimethyl-4,4'-diphenylenediamine, 1,4-naphthalenediamine, 1,5-naphthalenediamine, 2,6-naphthalenediamine, 2-phenyl-p-phenylenediamine, 2-phenoxy-p-phenylenediamine;

[0051] The structure of polyethylene glycol diglycidyl ether (PEGDE) is shown in (II):

[0052]

[0053] Wherein, n is an integer of 4 to 113, and the relative molecular mass of polyethylene glycol in polyethylene glycol diglycidyl ether (PEGDE) is 200 to 5000.

[0054] According to the present invention, the lithium salt is preferably one or more of lithium bis(trifluoromethanesulfonyl imide), lithium bis(fluorosulfonyl imide), lithium perchlorate, lithium difluorooxalatoborate, lithium hexafluorophosphate, and lithium tetrafluoroborate. The sodium salt is preferably one or more of sodium hexafluorophosphate, sodium perchlorate, sodium trifluoromethanesulfonate, sodium bis(fluorosulfonyl imide), and sodium bis(trifluoromethanesulfonyl imide).

[0055] According to the present invention, the ionic liquid is preferably one or more of imidazole, pyridine, piperidine and pyrrole ionic liquids; ionic liquids have attracted widespread attention due to their high ionic conductivity, wide electrochemical window, excellent thermal stability, no vapor pressure and non-flammability.

[0056] According to the present invention, the imidazole ionic liquid is preferably selected from 1-ethyl-3-methylimidazolium chloride, 1-ethyl-3-methylimidazolium bromide, 1-ethyl-3-methylimidazolium iodide, 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-ethyl-3-methylimidazolium hexafluorophosphate, 1-ethyl-3-methylimidazolium trifluoromethanesulfonyl imide, 1-ethyl-3-methylimidazolium bistrifluoromethanesulfonyl imide, 1-ethyl-3-methylimidazolium ethyl sulfate, 1-ethyl-3-methylimidazolium perchlorate, 1-ethyl-3-methylimidazolium p-toluenesulfonate, 1-propyl-3-methylimidazolium chloride, 1-propyl-3-methyl tetrafluoroborate, 1-propyl-3 1-Methylimidazolium hexafluorophosphate, 1-propyl-3-methylimidazolium trifluoromethanesulfonimide, 1-propyl-3-methylimidazolium bistrifluoromethanesulfonimide, 1-butyl-3-methylimidazolium chloride, 1-butyl-3-methylimidazolium bromide, 1-butyl-3-methylimidazolium iodide, 1-butyl-3-methylimidazolium nitrate, 1-butyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium hexafluorophosphate, 1-butyl-3-methylimidazolium methanesulfonate, 1-butyl-3-methylimidazolium p-toluenesulfonate, 1-butyl-3-methylimidazolium dihydrogenphosphate, 1-butyl-3-methylimidazolium thiocyanate, 1-butyl-3-methylimidazolium trifluoromethanesulfonate, Sulfonylimide, 1-butyl-3-methylimidazolium bistrifluoromethanesulfonyl imide, 1-butyl-3-methylimidazolium dicyanamide, 1-hexyl-3-methylimidazolium hexafluorophosphate, 1-octyl-3-methylimidazolium tetrafluorophosphate, 1-decyl-3-methylimidazolium perchlorate, 1-dodecane-3-methylimidazolium chloride, 1-dodecane-3-methylimidazolium tetrafluorophosphate, 1-dodecane-3-methylimidazolium hexafluorophosphate, 1-tetradecane-3-methylimidazolium bromide, 1-tetradecane-3-methylimidazolium hexafluorophosphate, 1-butyl-2,3-dimethylimidazolium bromide, 1-butyl-2,3-dimethylimidazolium hexafluorophosphate, 1-butyl-2,3 One or more of the following: 1-butyl-2,3-dimethylimidazole perchlorate, 1-butyl-2,3-dimethylimidazole tetrafluoroborate, 1-butyl-2,3-dimethylimidazole nitrate, 1-butyl-2,3-dimethylimidazole p-toluenesulfonate, 1-butyl-2,3-dimethylimidazole dihydrogenphosphate, 1-butyl-2,3-dimethylimidazole hydrogensulfate, 1-hexyl-2,3-dimethylimidazole tetrafluoroborate, 1-hexyl-2,3-dimethylimidazole chloride, 1-hexyl-2,3-dimethylimidazole hexafluorophosphate, 1-hexyl-2,3-dimethylimidazole perchlorate, 1-hexyl-2,3-dimethylimidazole bromide, and 1-sulfonic acid propyl-3-methylimidazole inner salt.

[0057] The pyridine ionic liquid is preferably one or more of N-ethylpyridine bis(trifluoromethanesulfonyl)imide, N-ethylpyridine hexafluorophosphate, N-ethylpyridine tetrafluoroborate, N-ethylpyridine perchlorate, N-ethylpyridine bromide, N-butylpyridine chloride, N-butylpyridine bromide, N-butylpyridine iodide, N-butylpyridine tetrafluoroborate, N-butylpyridine hexafluorophosphate, N-butylpyridine perchlorate, N-butylpyridine p-toluenesulfonate, N-butylpyridine bis(trifluoromethanesulfonyl)imide, N-hexylpyridine tetrafluoroborate, N-hexylpyridine hexafluorophosphate, N-hexylpyridine bis(trifluoromethanesulfonyl)imide, N-octylpyridine perchlorate, N-sulfonic acid propylpyridine hydrogen sulfate, N-sulfonic acid propyl-3-methylpyridine p-toluenesulfonate, and pyridinesulfonic acid propiolactone.

[0058] The piperidine ionic liquid is preferably one or more of N-propyl-N-methylpiperidinium chloride, N-propyl-N-methylpiperidinium bromide, N-propyl-N-methylpiperidinium iodide, N-propyl-N-methylpiperidinium perchlorate, N-propyl-N-methylpiperidinium trifluoromethanesulfonyl imide, N-propyl-N-methylpiperidinium bistrifluoromethanesulfonyl imide, and N-propyl-N-methylpiperidinium difluorooxalatoborate.

[0059] The pyrrole ionic liquid is preferably one or more of N-ethyl-N-methylpyrrolidine chloride, N-ethyl-N-methylpyrrolidine bromide, N-ethyl-N-methylpyrrolidine tetrafluoroborate, N-propyl-N-methylpyrrolidine trifluoromethanesulfonyl imide, N-propyl-N-methylpyrrolidine perchlorate, N-propyl-N-methylpyrrolidine tetrafluoroborate, N-propyl-N-methylpyrrolidine hexafluorophosphate, N-propyl-N-methylpyrrolidine bistrifluoromethanesulfonyl imide, N-butyl-N-methylpyrrolidine hexafluoroborate, N-butyl-N-methylpyrrolidine bromide, N-butyl-N-methylpyrrolidine bistrifluoromethanesulfonyl imide, N-butyl-N-methylpyrrolidine perchlorate, and N-butyl-N-methylpyrrolidine trifluoromethanesulfonate.

[0060] The present invention provides a method for preparing a solid polymer electrolyte containing an ionic liquid, comprising the following steps:

[0061] The polyethylene glycol diglycidyl ether is melted, the melting temperature is preferably 25-80°C, and then a lithium salt or sodium salt is added and stirred to dissolve, the stirring and dissolving temperature of the lithium salt or sodium salt is preferably 10-80°C, and then an ionic liquid is added and stirred to dissolve, the stirring temperature of the ionic liquid is preferably 0-60°C, and the time is 5min-24h. Finally, a diamine monomer is added and dissolved. After the reaction is completed, the dissolving temperature of the added diamine monomer is preferably 10-80°C, and the dissolving time is preferably 3min-48h. Then, the solution is allowed to stand for degassing, the standing degassing temperature is preferably 5-40°C, and the standing degassing time is preferably 0.05-4h. An in-situ polymerization reaction is carried out at a certain temperature to obtain a solid polymer electrolyte containing an ionic liquid.

[0062] In actual application, a polymer electrolyte precursor solution is obtained after standing and degassing, and then the polymer electrolyte precursor solution is assembled with the positive electrode and the negative electrode to form a solid-state battery. The solution is then allowed to stand and in situ polymerize for 0.5-48 hours at 10-120°C. In this process, a solid polymer electrolyte containing an ionic liquid is obtained.

[0063] According to the present invention, the molar ratio of the diamine monomer to polyethylene glycol diglycidyl ether is 1:(1-8); the molar ratio of the lithium ions or sodium ions in the lithium salt or sodium salt to the ether oxygen atoms in the polymer of formula (I) is 1:(2-128), and the content of the ionic liquid is 5-300wt% of the mass of the polymer electrolyte.

[0064] The present invention also provides the use of the above-mentioned solid polymer electrolyte containing ionic liquid in lithium ion batteries or sodium ion batteries.

[0065] The present invention will be described in more detail below with reference to the embodiments and accompanying drawings. It should be understood that the embodiments described herein are only a portion of the present invention and are not intended to limit the present invention.

[0066] Example 1

[0067] Ethylenediamine-polyethylene glycol diglycidyl ether PEGDE 2000 solid polymer electrolyte

[0068] The preparation method of the solid polymer electrolyte is as follows: 5.164g polyethylene glycol diglycidyl ether PEGDE 2000Melt at 55°C, add 0.567g of lithium bis(trifluoromethanesulfonyl imide) and stir at 55°C until completely dissolved. Then add 0.16g of 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl imide) and stir at 55°C until evenly mixed. Add 0.1g of ethylenediamine monomer and stir for 20 minutes (diamine monomer completely dissolved). The mixture is then allowed to stand at 30°C for 10 minutes to degas, yielding a viscous precursor solution. This is then in-situ polymerized with the corresponding positive and negative electrodes and allowed to stand at room temperature for 30 hours to yield a solid polymer electrolyte.

[0069] Solid polymer electrolyte ionic conductivity testing: 0.3 ml of the viscous precursor solution was combined with a stainless steel sheet to form a R2032 coin cell with a "stainless steel sheet / SPE / stainless steel sheet" configuration. Lithium ion conductivity was measured using electrochemical impedance spectroscopy (EIS) with a frequency range of 400 mHz to 1 MHz and a scan rate of 10 mV·s. -1 , using the formula: σ=L / AR b , where L is the thickness of the electrolyte, A is the area of ​​the stainless steel sheet at room temperature, and R b The measured impedance is shown in Figure 2. The thickness of the solid sodium ion solid polymer electrolyte membrane is 287 μm, and the ionic conductivity is 2.87×10 -5 S cm -1 .

[0070] Testing the electrochemical window of a solid polymer electrolyte: A certain amount of viscous precursor solution was assembled with a stainless steel sheet and a lithium sheet to form a "stainless steel sheet / SPE / lithium sheet" R2032 button cell. The electrochemical window was measured using a linear voltammetric sweep using an electrochemical workstation, starting at the open circuit potential, with a maximum potential of 7 V and a scan rate of 1 mV·s. -1 . After testing, the electrochemical window of the solid polymer electrolyte is 4.4V.

[0071] Example 2

[0072] 1,6-Hexanediamine-polyethylene glycol diglycidyl ether PEGDE 500 solid polymer electrolyte

[0073] The preparation method of the solid polymer electrolyte is as follows: 3.185g polyethylene glycol diglycidyl ether PEGDE 5001.33g of lithium bis(trifluoromethanesulfonyl imide) was added and stirred at room temperature until completely dissolved. 1.049g of N-propyl-N-methylpyrrole bis(trifluoromethanesulfonyl imide) was then added and stirred at room temperature until uniformly mixed. 0.1g of 1,6-hexanediamine monomer was added and stirred for 13 minutes (until the diamine monomer completely dissolved). The mixture was then allowed to stand at room temperature for 5 minutes to degas, yielding a viscous precursor solution. This solution was then in-situ polymerized with the corresponding positive and negative electrodes and allowed to stand at room temperature for 48 hours to yield a solid polymer electrolyte.

[0074] Solid polymer electrolyte ionic conductivity testing: 0.1 ml of the thick precursor solution was combined with a stainless steel sheet to form a "stainless steel sheet / SPE / stainless steel sheet" R2032 button cell. Lithium ion conductivity was measured using electrochemical impedance spectroscopy (EIS) with a frequency range of 400 mHz to 1 MHz and a scan rate of 10 mV·s. -1 , using the formula: σ=L / AR b , where L is the thickness of the electrolyte, A is the area of ​​the stainless steel sheet at room temperature, and R b The measured impedance is shown in Figure 2. The solid sodium ion solid polymer electrolyte membrane has a thickness of 87 μm and an ionic conductivity of 5.87×10 -4 S cm -1 .

[0075] Testing the electrochemical window of a solid polymer electrolyte: A certain amount of viscous precursor solution was assembled with a stainless steel sheet and a lithium sheet to form a "stainless steel sheet / SPE / lithium sheet" R2032 button cell. The electrochemical window was measured using a linear voltammetric sweep using an electrochemical workstation, starting at the open circuit potential, with a maximum potential of 7 V and a scan rate of 1 mV·s. -1 . After testing, the electrochemical window of the solid polymer electrolyte is 5.0V.

[0076] Figure 2 This is the thermogravimetric curve of the cross-linked solid polymer electrolyte described in Example 2. Figure 2 This shows that the solid polymer electrolyte has good thermal stability and the thermal decomposition temperature reaches above 300°C.

[0077] Figure 3 This is the differential scanning calorimetry test curve of the cross-linked solid polymer electrolyte described in Example 2. Figure 3 This shows that the solid polymer electrolyte has a low glass transition temperature of -30.05℃.

[0078] Figure 4 This is the X-ray diffraction pattern of the cross-linked solid polymer electrolyte described in Example 2. Figure 4This shows that the solid polymer electrolyte has no obvious crystallization peak, and the peak is in a diffuse state. The crystallinity is low at 3.76% (R=0.82%) when fitted with the software JADE.

[0079] Figure 5 This is a curve showing the change in conductivity of the cross-linked solid polymer electrolyte described in Example 2 as a function of temperature. Figure 5 This shows that the conductivity of the solid polymer electrolyte increases with increasing temperature and has a relatively high conductivity.

[0080] Figure 6 This is the electrochemical window test curve of the cross-linked solid polymer electrolyte described in Example 2. Figure 6 This shows that the solid polymer electrolyte has a wide electrochemical window, up to 5.0V.

[0081] Example 3

[0082] 1,8-Octanediamine-polyethylene glycol diglycidyl ether PEGDE 1000 solid polymer electrolyte

[0083] The preparation method of the solid polymer electrolyte is as follows: take 2.582g polyethylene glycol diglycidyl ether PEGDE 1000 Melt the mixture at 45°C, add 0.782g of lithium bis(fluorosulfonyl)imide and stir at 45°C until completely dissolved. Then, add 1.689g of N-propyl-N-methylpiperidinium bis(trifluoromethanesulfonyl)imide and stir until evenly mixed at 45°C. Add 0.1g of 1,8-hexanediamine monomer and stir for 18 minutes (until the diamine monomer is completely dissolved). The mixture is then allowed to stand at room temperature for 10 minutes to degas, yielding a viscous precursor solution. This solution is then in-situ polymerized with the corresponding positive and negative electrodes at 30°C for 36 hours to yield a solid polymer electrolyte.

[0084] Solid polymer electrolyte ionic conductivity testing: 0.2 ml of the viscous precursor solution was assembled with a stainless steel sheet to form a R2032 coin cell with a "stainless steel sheet / SPE / stainless steel sheet" configuration. Lithium ion conductivity was measured using electrochemical impedance spectroscopy (EIS) with a frequency range of 400 mHz to 1 MHz and a scan rate of 10 mV·s. -1 , using the formula: σ=L / AR b , where L is the thickness of the electrolyte, A is the area of ​​the stainless steel sheet at room temperature, and R b The measured impedance is shown in Table 1. The thickness of the solid polymer electrolyte membrane is 151 μm, and the ionic conductivity is 1.87×10 -4 S cm -1 .

[0085] Testing the electrochemical window of a solid polymer electrolyte: 0.2 ml of the viscous precursor solution was assembled with a stainless steel sheet and a lithium sheet to form a R2032 coin cell with a stainless steel sheet / SPE / lithium sheet. The electrochemical window was measured using a linear voltammetric sweep using an electrochemical workstation, starting at the open circuit potential, with a maximum potential of 7 V and a scan rate of 1 mV·s. -1 . After testing, the electrochemical window of the solid polymer electrolyte is 4.5V.

[0086] Example 4

[0087] p-phenylenediamine-polyethylene glycol diglycidyl ether PEGDE 500 solid polymer electrolyte

[0088] The preparation method of the solid polymer electrolyte is as follows: 1.418g of liquid polyethylene glycol diglycidyl ether PEGDE is taken at room temperature. 500 0.738g of lithium bis(trifluoromethanesulfonyl)imide was added and stirred at room temperature until completely dissolved. 1.25g of N-butyl-N-methylpyridinium bis(trifluoromethanesulfonyl)imide salt was added and stirred at room temperature until uniformly mixed. 0.1g of p-phenylenediamine monomer was added and stirred for 26 minutes (until the diamine monomer was completely dissolved). The mixture was then allowed to stand at room temperature for 15 minutes to degas, yielding a viscous precursor solution. This solution was then in-situ polymerized with the corresponding positive and negative electrodes and allowed to stand at room temperature for 72 hours to yield a solid polymer electrolyte.

[0089] Solid polymer electrolyte ionic conductivity testing: 0.1 ml of the viscous precursor solution was assembled with a stainless steel sheet to form a "stainless steel sheet / SPE / stainless steel sheet" R2032 button cell. Lithium ion conductivity was measured using electrochemical impedance spectroscopy (EIS) with a test frequency range of 400 mHz to 1 MHz and a scan rate of 10 mV·s. -1 , using the formula: σ=L / AR b , where L is the thickness of the electrolyte, A is the area of ​​the stainless steel sheet at room temperature, and R b The measured impedance is shown in Figure 2. The thickness of the solid polymer electrolyte membrane is 88 μm, and the ionic conductivity is 1.05×10 -4 S cm -1 .

[0090] Testing the electrochemical window of a solid polymer electrolyte: 0.1 ml of the viscous precursor solution was assembled with a stainless steel sheet and a lithium sheet to form a R2032 coin cell. The electrochemical window was measured using a linear voltammetric sweep using an electrochemical workstation, starting at the open circuit potential, with a maximum potential of 7 V and a scan rate of 1 mV·s. -1 . After testing, the electrochemical window of the solid polymer electrolyte is 4.0V.

[0091] Example 5

[0092] 1,10-Decanediamine-polyethylene glycol diglycidyl ether PEGDE 4000 solid polymer electrolyte

[0093] The preparation method of the solid polymer electrolyte is as follows: take 6.5g polyethylene glycol diglycidyl ether PEGDE 4000 Melt the mixture at 60°C, add 0.769g of lithium trifluoromethanesulfonate and stir at 60°C until completely dissolved. Then, add 7.92g of N-propyl-N-methylpyrrole bis(trifluoromethanesulfonyl)imide and stir at 60°C until evenly mixed. Add 0.1g of 1,10-decanediamine monomer and stir for 45 minutes (until the diamine monomer is completely dissolved). The mixture is then allowed to stand at room temperature for 20 minutes to degas, yielding a viscous precursor solution. This solution is then in-situ polymerized with the corresponding positive and negative electrodes and allowed to stand at room temperature for 70 hours to yield a solid polymer electrolyte.

[0094] Solid polymer electrolyte ionic conductivity testing: 0.4 ml of the viscous precursor solution was combined with a stainless steel sheet to form a "stainless steel sheet / SPE / stainless steel sheet" R2032 button cell. Lithium ion conductivity was measured using electrochemical impedance spectroscopy (EIS) with a frequency range of 400 mHz to 1 MHz and a scan rate of 10 mV·s. -1 , using the formula: σ=L / AR b , where L is the thickness of the electrolyte, A is the area of ​​the stainless steel sheet at room temperature, and R b The measured impedance is shown in Figure 2. The solid sodium ion solid polymer electrolyte membrane has a thickness of 395 μm and an ionic conductivity of 4.8×10 -4 S cm -1 .

[0095] Testing the electrochemical window of a solid polymer electrolyte: 0.4 ml of the viscous precursor solution was assembled with a stainless steel sheet and a lithium sheet to form a R2032 coin cell. The electrochemical window was measured using a linear voltammetric sweep using an electrochemical workstation, starting at the open circuit potential, with a maximum potential of 7 V and a scan rate of 1 mV·s. -1 . After testing, the electrochemical window of the solid polymer electrolyte is 4.0V.

[0096] Comparative Example 1

[0097] Instead of in-situ polymerization, the resulting viscous precursor solution was poured into a polytetrafluoroethylene mold or a glass culture dish and allowed to stand for polymerization for the same time and temperature as in Example 2 after the battery was assembled. After solidification, a solid polymer electrolyte film was obtained, which was then cut into 16 mm diameter discs using a slicer to assemble the corresponding button cells. Other feed ratios, reaction conditions, and precursor solution preparation and testing conditions were similar to those in Example 2. The resulting solid sodium ion polymer electrolyte film had a thickness of 45 μm and a room temperature conductivity of 7.98 × 10 -5 S cm -1 , the electrochemical stability window is 4.5V.

[0098] Figure 1 This is a SEM surface image of the cross-linked solid polymer electrolyte described in Comparative Example 1. Figure 1 This shows that the surface structure of the solid polymer electrolyte is smooth, uniform and dense.

[0099] Comparative Example 2

[0100] No ionic liquid N-butyl-N-methylpyrrole bis(trifluoromethanesulfonyl)imide salt was added, and other feed ratios, reaction conditions, and test conditions were consistent with those in Example 2. The film thickness of the obtained solid polymer electrolyte was 98 μm, and the room temperature conductivity was 3.86×10 -5 S cm -1 , the electrochemical stability window is 4.0V.

[0101] Table 1 Comparison of feed composition and electrochemical performance of solid polymer electrolytes in Examples and Comparative Examples

[0102]

[0103]

[0104] Example 6

[0105] Ethylenediamine-polyethylene glycol diglycidyl ether PEGDE 500 solid polymer electrolyte

[0106] The preparation method of the solid sodium ion polymer electrolyte is as follows: 1.498g of liquid polyethylene glycol diglycidyl ether PEGDE is taken at room temperature. 500 0.567g of sodium bis(trifluoromethanesulfonyl imide) was added and dissolved completely with stirring at room temperature. 0.16g of 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl imide) was then added and mixed uniformly with stirring at room temperature. 0.1g of ethylenediamine monomer was added and stirred for 12 minutes (until the diamine monomer was completely dissolved). The mixture was then allowed to stand at room temperature for 8 minutes to degas, yielding a viscous precursor solution. This solution was then in-situ polymerized with the corresponding positive and negative electrodes and allowed to stand at room temperature for 24 hours to yield a solid sodium ion polymer electrolyte.

[0107] Testing the ionic conductivity of solid-state sodium-ion polymer electrolytes: 0.4 ml of the viscous precursor solution was assembled with a stainless steel sheet to form a R2032 coin cell with a "stainless steel sheet / SPE / stainless steel sheet" pattern. Sodium ion conductivity was measured using electrochemical impedance spectroscopy (EIS) with a frequency range of 400 mHz to 1 MHz and a scan rate of 10 mV·s. -1 , using the formula: σ=L / AR b , where L is the thickness of the electrolyte, A is the area of ​​the stainless steel sheet at room temperature, and R b The measured impedance is shown in Figure 2. The solid sodium ion solid polymer electrolyte membrane has a thickness of 395 μm and an ionic conductivity of 1.87×10 -5 S cm -1 .

[0108] Testing the electrochemical window of a solid-state sodium-ion polymer electrolyte: 0.4 ml of the viscous precursor solution was assembled with a stainless steel sheet and a sodium sheet to form a "stainless steel sheet / SPE / sodium sheet" R2032 button cell. The electrochemical window was measured using a linear voltammetric sweep using an electrochemical workstation, starting at the open circuit potential, reaching a maximum potential of 7 V, and scanning at a rate of 1 mV·s. -1 After testing, the electrochemical window of the solid polymer electrolyte was found to be 4.25V.

[0109] Example 7

[0110] 1,6-Hexanediamine-polyethylene glycol diglycidyl ether PEGDE 2000 solid polymer electrolyte

[0111] The preparation method of the solid sodium ion polymer electrolyte is as follows: 5.164g polyethylene glycol diglycidyl ether PEGDE 2000 Melt the mixture at 55°C, add 1.33g of sodium perchlorate and stir at 57°C until completely dissolved. Then, add 1.049g of 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide and stir at 57°C until uniformly mixed. Add 0.1g of 1,6-hexanediamine monomer and stir for 25 minutes (until the diamine monomer is completely dissolved). The mixture is then allowed to stand at room temperature for 13 minutes to degas, yielding a viscous precursor solution. This solution is then in-situ polymerized with the corresponding positive and negative electrodes at 40°C for 48 hours to yield a solid sodium ion polymer electrolyte.

[0112] Testing the ionic conductivity of solid-state sodium-ion polymer electrolytes: 0.2 ml of the viscous precursor solution was assembled with a stainless steel sheet to form a R2032 coin cell with a "stainless steel sheet / SPE / stainless steel sheet" pattern. Sodium ion conductivity was measured using electrochemical impedance spectroscopy (EIS) with a frequency range of 400 mHz to 1 MHz and a scan rate of 10 mV·s.-1 , using the formula: σ=L / AR b , where L is the thickness of the electrolyte, A is the area of ​​the stainless steel sheet at room temperature, and R b The measured impedance is shown in Figure 2. The solid sodium ion solid polymer electrolyte membrane has a thickness of 199 μm and an ionic conductivity of 6.96×10 -5 S cm -1 .

[0113] Testing the electrochemical window of a solid-state sodium-ion polymer electrolyte: 0.2 ml of the viscous precursor solution was assembled with a stainless steel sheet and a sodium sheet to form a R2032 coin cell. The electrochemical window was measured using a linear voltammetric sweep using an electrochemical workstation, starting at the open circuit potential, reaching a maximum potential of 7 V, and scanning at a rate of 1 mV·s. -1 . After testing, the electrochemical window of the solid polymer electrolyte is 4.0V.

[0114] Example 8

[0115] 1,6-Hexanediamine-polyethylene glycol diglycidyl ether PEGDE 1000 solid polymer electrolyte

[0116] The preparation method of the solid sodium ion polymer electrolyte is as follows: take 2.582g polyethylene glycol diglycidyl ether PEGDE 1000 Melt the mixture at 43°C, add 0.688g of sodium bis(fluorosulfonyl)imide, and stir at 45°C until completely dissolved. Then, add 1.073g of N-propyl-N-methylpyrrole bis(trifluoromethanesulfonyl)imide salt and stir until evenly mixed at 45°C. Add 0.1g of 1,6-hexanediamine monomer and stir for 20 minutes (until the diamine monomer is completely dissolved). The mixture is then allowed to stand at room temperature for 10 minutes to degas, yielding a viscous precursor solution. This solution is then in-situ polymerized with the corresponding positive and negative electrodes at 30°C for 36 hours to yield a solid sodium ion polymer electrolyte.

[0117] Testing the ionic conductivity of solid-state sodium-ion polymer electrolytes: 0.2 ml of the viscous precursor solution was assembled with a stainless steel sheet to form a R2032 coin cell with a "stainless steel sheet / SPE / stainless steel sheet" pattern. Sodium ion conductivity was measured using electrochemical impedance spectroscopy (EIS) with a frequency range of 400 mHz to 1 MHz and a scan rate of 10 mV·s. -1 , using the formula: σ=L / AR b , where L is the thickness of the electrolyte, A is the area of ​​the stainless steel sheet at room temperature, and R b The measured impedance is shown in Figure 2. The solid sodium ion solid polymer electrolyte membrane has a thickness of 139 μm and an ionic conductivity of 2.52×10 -4 S cm-1 .

[0118] Testing the electrochemical window of a solid-state sodium-ion polymer electrolyte: 0.2 ml of the viscous precursor solution was assembled with a stainless steel sheet and a sodium sheet to form a R2032 coin cell. The electrochemical window was measured using a linear voltammetric sweep using an electrochemical workstation, starting at the open circuit potential, reaching a maximum potential of 7 V, and scanning at a rate of 1 mV·s. -1 . After testing, the electrochemical window of the solid polymer electrolyte is 5.0V.

[0119] Example 9

[0120] 1,4-Butanediamine-polyethylene glycol diglycidyl ether PEGDE 500 solid polymer electrolyte

[0121] The preparation method of the solid sodium ion polymer electrolyte is as follows: 1.418g of liquid polyethylene glycol diglycidyl ether PEGDE is taken at room temperature. 500 0.537g of sodium bis(trifluoromethanesulfonyl imide) was added and stirred at room temperature until completely dissolved. 1.139g of N-butyl-N-methylpyrrole bis(trifluoromethanesulfonyl imide) was added and stirred at room temperature until evenly mixed. 0.1g of 1,4-butanediamine monomer was added and stirred for 15 minutes (until the diamine monomer completely dissolved). The mixture was then allowed to stand at room temperature for 10 minutes to degas, yielding a viscous precursor solution. This solution was then in-situ polymerized with the corresponding positive and negative electrodes and allowed to stand at room temperature for 28 hours to yield a solid sodium ion polymer electrolyte.

[0122] Testing the ionic conductivity of a solid-state sodium-ion polymer electrolyte: 0.3 ml of the viscous precursor solution was assembled with a stainless steel sheet to form a R2032 coin cell with a "stainless steel sheet / SPE / stainless steel sheet" pattern. Sodium ion conductivity was measured using electrochemical impedance spectroscopy (EIS) with a frequency range of 400 mHz to 1 MHz and a scan rate of 10 mV·s. -1 , using the formula: σ=L / AR b , where L is the thickness of the electrolyte, A is the area of ​​the stainless steel sheet at room temperature, and R b The measured impedance is shown in Figure 2. The thickness of the solid sodium ion solid polymer electrolyte membrane is 253 μm, and the ionic conductivity is 7.53×10 -4 S cm -1 .

[0123] Testing the electrochemical window of a solid-state sodium-ion polymer electrolyte: 0.3 ml of the viscous precursor solution was assembled with a stainless steel sheet and a sodium sheet to form a R2032 coin cell. The electrochemical window was measured using a linear voltammetric sweep using an electrochemical workstation, starting at the open circuit potential, reaching a maximum potential of 7 V, and scanning at a rate of 1 mV·s. -1 After testing, the electrochemical window of the solid polymer electrolyte was found to be 5.6V.

[0124] Figure 7 This is the thermogravimetric curve of the solid sodium ion polymer electrolyte described in Example 9. Figure 7 This shows that the solid polymer electrolyte has good thermal stability and the thermal decomposition temperature reaches above 300°C.

[0125] Figure 8 This is the differential scanning calorimetry test curve of the solid sodium ion polymer electrolyte described in Example 9. Figure 8 This shows that the solid polymer electrolyte has a low glass transition temperature of -36.71℃.

[0126] Figure 9 This is the X-ray diffraction pattern of the solid sodium ion polymer electrolyte described in Example 9. Figure 9 This shows that the solid polymer electrolyte has no obvious crystallization peak, and the peak is in a diffuse state. The crystallinity is low at 2.15% (R=0.25%) when fitted with the software JADE.

[0127] Figure 10 This is the impedance diagram of the solid sodium ion polymer electrolyte described in Example 9 at room temperature. Figure 10 This shows that the solid polymer electrolyte has a low impedance value of only 16 ohm at room temperature.

[0128] Figure 11 3 is a curve showing the change in electrical conductivity of the solid sodium ion polymer electrolyte as a function of temperature. Figure 11 This shows that the conductivity of the solid polymer electrolyte increases with increasing temperature and has a relatively high conductivity.

[0129] Figure 12 This is the electrochemical window test curve of the solid sodium ion polymer electrolyte described in Example 9. Figure 12 This shows that the solid polymer electrolyte has a wide electrochemical window, up to 5.6V.

[0130] Example 10

[0131] 1,10-Decanediamine-polyethylene glycol diglycidyl ether PEGDE 4000 solid polymer electrolyte

[0132] The preparation method of the solid sodium ion polymer electrolyte is as follows: take 6.5g polyethylene glycol diglycidyl ether PEGDE 4000 Melt the mixture at 60°C, add 0.869g of sodium trifluoromethanesulfonate and stir at 62°C until completely dissolved. Then, add 7.92g of N-propyl-N-methylpiperidinium bis(trifluoromethanesulfonyl)imide and stir at 60°C until uniformly mixed. Add 0.1g of 1,10-decanediamine monomer and stir for 40 minutes (until the diamine monomer is completely dissolved). The mixture is then allowed to stand at room temperature for 18 minutes to degas, yielding a viscous precursor solution. This solution is then in-situ polymerized with the corresponding positive and negative electrodes and allowed to stand at room temperature for 72 hours to yield a solid sodium ion polymer electrolyte.

[0133] Testing the ionic conductivity of solid-state sodium-ion polymer electrolytes: 0.1 ml of the viscous precursor solution was assembled with a stainless steel sheet to form a R2032 coin cell with a "stainless steel sheet / SPE / stainless steel sheet" pattern. Sodium ion conductivity was measured using electrochemical impedance spectroscopy (EIS) with a frequency range of 400 mHz to 1 MHz and a scan rate of 10 mV·s. -1 , using the formula: σ=L / AR b , where L is the thickness of the electrolyte, A is the area of ​​the stainless steel sheet at room temperature, and R b The measured impedance is shown in Figure 2. The solid sodium ion solid polymer electrolyte membrane has a thickness of 86 μm and an ionic conductivity of 3.85×10 -4 S cm -1 .

[0134] Testing the electrochemical window of a solid-state sodium-ion polymer electrolyte: 0.1 ml of the viscous precursor solution was assembled with a stainless steel sheet and a sodium sheet to form a R2032 coin cell. The electrochemical window was measured using a linear voltammetric sweep using an electrochemical workstation, starting at the open circuit potential, reaching a maximum potential of 7 V, and scanning at a rate of 1 mV·s. -1 . After testing, the electrochemical window of this solid polymer electrolyte is 3.9V.

[0135] Comparative Example 3

[0136] Instead of in-situ polymerization, the resulting viscous precursor solution was poured into a polytetrafluoroethylene mold and allowed to stand for polymerization for the same time and temperature as in-situ polymerization after battery assembly in Example 4. After solidification, a solid polymer electrolyte film was obtained, which was then cut into 16 mm diameter discs using a slicer to assemble corresponding button cells. Other feed ratios, reaction conditions, and precursor solution preparation and testing conditions were similar to those in Example 4. The resulting solid sodium ion polymer electrolyte film had a thickness of 323 μm and a room temperature conductivity of 8.99×10 -5 S cm -1 , the electrochemical stability window is 5.3V.

[0137] Comparative Example 4

[0138] Without adding ionic liquid N-butyl-N-methylpyrrole bis(trifluoromethanesulfonyl)imide salt, other feed ratios, reaction conditions, preparation of precursor solution and test conditions were the same as those in Example 4. The obtained solid sodium ion polymer electrolyte had a film thickness of 183 μm and a room temperature conductivity of 3.86×10 -5 S cm -1 , the electrochemical stability window is 4.7V.

[0139] Table 2 Comparison of feed composition and electrochemical performance of solid polymer electrolytes in Examples and Comparative Examples

[0140]

[0141]

[0142] The preparation process of the solid polymer electrolyte provided by the present invention is carried out under low water and oxygen content conditions, with the water and oxygen content being less than 0.5 ppm. Furthermore, the above embodiments are merely preferred embodiments of the present invention, not all embodiments. The technical features involved in the various embodiments described above may be combined as long as they do not conflict with each other. Based on the embodiments of the present invention, other embodiments and drawings derived by persons skilled in the art without inventive effort are also within the scope of protection of the present invention.

Claims

1. A solid polymer electrolyte containing an ionic liquid, characterized in that It includes a cross-linked polymer matrix, a lithium salt or a sodium salt, and an ionic liquid. The structure of the cross-linked polymer matrix is ​​shown in formula (I): wherein R comprises aliphatic chains or aromatic rings in different diamine monomers; n is an integer from 4 to 113.

2. The solid polymer electrolyte containing ionic liquid according to claim 1, characterized in that: The cross-linked polymer matrix is ​​prepared by in-situ polymerization of polyethylene glycol diglycidyl ether and diamine monomers through nucleophilic addition reaction, wherein the diamine monomers include aliphatic diamine monomers and aromatic diamine monomers, and the aliphatic diamine monomers include NH2-(CH2) m -NH2, m is an integer of 2 to 30, and aliphatic diamine monomers containing branches of different carbon chain lengths at different positions; aromatic diamine monomers include benzyl diamine, p-phenylenediamine, m-phenylenediamine, o-phenylenediamine, 2-methyl-1,4-phenylenediamine, 2-phenyl-1,4-phenylenediamine, 2-ethyl-1,4-phenylenediamine, 2-propyl-1,4-phenylenediamine, 2-isopropyl-1,4-phenylenediamine , 2-butyl-1,4-phenylenediamine, 2-isobutyl-1,4-phenylenediamine, 2-pentyl-1,4-phenylenediamine, 2-chloro-1,4-phenylenediamine, 2-bromo-1,4-phenylenediamine, 4,4-diphenylenediamine, 2,2'-dimethyl-4,4'-diphenylenediamine, 1,4-naphthalenediamine, 1,5-naphthalenediamine, 2,6-naphthalenediamine, 2-phenyl-p-phenylenediamine, 2-phenoxy-p-phenylenediamine; The structure of polyethylene glycol diglycidyl ether (PEGDE) is shown in (II): Wherein, n is an integer of 4 to 113, and the relative molecular mass of polyethylene glycol in polyethylene glycol diglycidyl ether (PEGDE) is 200 to 5000.

3. The solid polymer electrolyte containing ionic liquid according to claim 1, characterized in that: The lithium salt is one or more of lithium bis(trifluoromethanesulfonyl imide), lithium bis(fluorosulfonyl imide), lithium perchlorate, lithium difluorooxalatoborate, lithium hexafluorophosphate, and lithium tetrafluoroborate; The sodium salt is one or more of sodium hexafluorophosphate, sodium perchlorate, sodium trifluoromethanesulfonate, sodium bis(fluorosulfonyl)imide, and sodium bis(trifluoromethanesulfonyl)imide.

4. The solid polymer electrolyte containing ionic liquid according to claim 1, characterized in that: The ionic liquid is one or more of imidazole, pyridine, piperidine and pyrrole ionic liquids.

5. The solid polymer electrolyte containing ionic liquid according to claim 4, characterized in that: The imidazole ionic liquid is selected from 1-ethyl-3-methylimidazolium chloride, 1-ethyl-3-methylimidazolium bromide, 1-ethyl-3-methylimidazolium iodide, 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-ethyl-3-methylimidazolium hexafluorophosphate, 1-ethyl-3-methylimidazolium trifluoromethanesulfonyl imide, 1-ethyl-3-methylimidazolium bistrifluoromethanesulfonyl imide, 1-ethyl-3-methylimidazolium ethyl sulfate, 1-ethyl-3-methylimidazolium perchlorate, 1-ethyl-3-methylimidazolium p-toluenesulfonate, 1-propyl-3-methylimidazolium chloride, 1-propyl-3-methyl tetrafluoroborate, 1-propyl-3-methylimidazolium hexafluorophosphate, Fluorophosphate, 1-propyl-3-methylimidazolium trifluoromethanesulfonimide, 1-propyl-3-methylimidazolium bistrifluoromethanesulfonimide, 1-butyl-3-methylimidazolium chloride, 1-butyl-3-methylimidazolium bromide, 1-butyl-3-methylimidazolium iodide, 1-butyl-3-methylimidazolium nitrate, 1-butyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium hexafluorophosphate, 1-butyl-3-methylimidazolium methanesulfonate, 1-butyl-3-methylimidazolium p-toluenesulfonate, 1-butyl-3-methylimidazolium dihydrogenphosphate, 1-butyl-3-methylimidazolium thiocyanate, 1-butyl-3-methylimidazolium trifluoromethanesulfonimide Salt, 1-butyl-3-methylimidazolium bistrifluoromethanesulfonyl imide salt, 1-butyl-3-methylimidazolium dicyanamide salt, 1-hexyl-3-methylimidazolium hexafluorophosphate, 1-octyl-3-methylimidazolium tetrafluorophosphate, 1-decyl-3-methylimidazolium perchlorate, 1-dodecane-3-methylimidazolium chloride, 1-dodecane-3-methylimidazolium tetrafluorophosphate, 1-dodecane-3-methylimidazolium hexafluorophosphate, 1-tetradecane-3-methylimidazolium bromide, 1-tetradecane-3-methylimidazolium hexafluorophosphate, 1-butyl-2,3-dimethylimidazolium bromide, 1-butyl-2,3-dimethylimidazolium hexafluorophosphate, 1-butyl-2,3-dimethylimidazolium One or more of methylimidazole perchlorate, 1-butyl-2,3-dimethylimidazole tetrafluoroborate, 1-butyl-2,3-dimethylimidazole nitrate, 1-butyl-2,3-dimethylimidazole p-toluenesulfonate, 1-butyl-2,3-dimethylimidazole dihydrogenphosphate, 1-butyl-2,3-dimethylimidazole hydrogensulfate, 1-hexyl-2,3-dimethylimidazole tetrafluoroborate, 1-hexyl-2,3-dimethylimidazole chloride, 1-hexyl-2,3-dimethylimidazole hexafluorophosphate, 1-hexyl-2,3-dimethylimidazole perchlorate, 1-hexyl-2,3-dimethylimidazole bromide, and 1-sulfonic acid propyl-3-methylimidazole inner salt.

6. The solid polymer electrolyte containing ionic liquid according to claim 4, characterized in that: The pyridine ionic liquid is one or more of N-ethylpyridine bis(trifluoromethanesulfonyl)imide, N-ethylpyridine hexafluorophosphate, N-ethylpyridine tetrafluoroborate, N-ethylpyridine perchlorate, N-ethylpyridine bromide, N-butylpyridine chloride, N-butylpyridine bromide, N-butylpyridine iodide, N-butylpyridine tetrafluoroborate, N-butylpyridine hexafluorophosphate, N-butylpyridine perchlorate, N-butylpyridine p-toluenesulfonate, N-butylpyridine bis(trifluoromethanesulfonyl)imide, N-hexylpyridine tetrafluoroborate, N-hexylpyridine hexafluorophosphate, N-hexylpyridine bis(trifluoromethanesulfonyl)imide, N-octylpyridine perchlorate, N-sulfonic acid propylpyridine hydrogen sulfate, N-sulfonic acid propyl-3-methylpyridine p-toluenesulfonate, and pyridinesulfonic acid propiolactone.

7. The solid polymer electrolyte containing ionic liquid according to claim 4, characterized in that: The piperidine ionic liquid is one or more of N-propyl-N-methylpiperidinium chloride, N-propyl-N-methylpiperidinium bromide, N-propyl-N-methylpiperidinium iodide, N-propyl-N-methylpiperidinium perchlorate, N-propyl-N-methylpiperidinium trifluoromethanesulfonyl imide, N-propyl-N-methylpiperidinium bistrifluoromethanesulfonyl imide, and N-propyl-N-methylpiperidinium difluorooxalatoborate.

8. The solid polymer electrolyte containing ionic liquid according to claim 4, characterized in that: The pyrrole ionic liquid is one or more of N-ethyl-N-methylpyrrolidine chloride, N-ethyl-N-methylpyrrolidine bromide, N-ethyl-N-methylpyrrolidine tetrafluoroborate, N-propyl-N-methylpyrrolidine trifluoromethanesulfonyl imide, N-propyl-N-methylpyrrolidine perchlorate, N-propyl-N-methylpyrrolidine tetrafluoroborate, N-propyl-N-methylpyrrolidine hexafluorophosphate, N-propyl-N-methylpyrrolidine bistrifluoromethanesulfonyl imide, N-butyl-N-methylpyrrolidine hexafluoroborate, N-butyl-N-methylpyrrolidine bromide, N-butyl-N-methylpyrrolidine bistrifluoromethanesulfonyl imide, N-butyl-N-methylpyrrolidine perchlorate, and N-butyl-N-methylpyrrolidine trifluoromethanesulfonate.

9. The method for preparing a solid polymer electrolyte containing an ionic liquid according to claim 1, characterized in that: The following steps are involved: The polyethylene glycol diglycidyl ether is melted, and then lithium salt or sodium salt is added and stirred to dissolve, and then the ionic liquid is added. After stirring and dissolving, the diamine monomer is added to carry out a nucleophilic addition reaction. After the reaction is completed, the mixture is allowed to stand for degassing and an in-situ polymerization reaction is carried out to obtain a solid polymer electrolyte containing the ionic liquid.

10. The method for preparing a solid polymer electrolyte containing an ionic liquid according to claim 9, characterized in that: The molar ratio of the diamine monomer to polyethylene glycol diglycidyl ether is 1:(1-8); the molar ratio of the lithium ions or sodium ions in the lithium salt or sodium salt to the ether oxygen atoms in the polymer of formula (I) is 1:(2-128), and the content of the ionic liquid is 5-300wt% of the mass of the polymer electrolyte.

11. The method for preparing a solid polymer electrolyte containing an ionic liquid according to claim 9, characterized in that: The melting temperature of the polyethylene glycol diglycidyl ether is 25-80°C, the stirring and dissolving temperature of the lithium salt or sodium salt is 10-80°C, the stirring temperature of the ionic liquid is 0-60°C, and the stirring time is 5 minutes to 24 hours. The dissolving temperature of the added diamine monomer is 10-80°C, and the dissolving time is 3 minutes to 48 hours. The standing and degassing temperature is 5-40°C, and the standing and degassing time is 0.05-4 hours.

12. The method for preparing a solid polymer electrolyte containing an ionic liquid according to claim 9, characterized in that: The temperature of the in-situ polymerization is 10-120° C., and the time is 2-72 hours.

13. Use of the solid polymer electrolyte containing ionic liquid according to claim 1 in lithium ion batteries or sodium ion batteries.

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