阅读说明：本技术 凝胶电解液前驱体及其在制备低内阻准固态超级电容器方面的应用 (Gel electrolyte precursor and application thereof in preparation of low-internal-resistance standard solid-state supercapacitor ) 是由 李文生 王道林 金振兴 高飞 刘璐 常亮 塔娜 于 2019-10-28 设计创作，主要内容包括：本发明属超级电容器制备领域,尤其涉及凝胶电解液前驱体及其在制备低内阻准固态超级电容器方面的应用,凝胶电解液前驱体包括凝胶因子、电解质盐及电解质溶剂；所述凝胶因子包括凝胶单体和引发剂。低内阻准固态超级电容器方面的制备包括以下步骤：(1)将正、负极片以及隔离膜组装成裸电芯之后,入壳,得到待注液电芯；(2)将凝胶电解液前驱体真空注入电芯后封口,放置2～5h,在65～75℃下加热2～5h,引发凝胶单体聚合；(3)产品化成,并对制得的低内阻准固态超级电容器进行性能测试。本发明低内阻准固态超级电容器具有电导率高,内阻低,循环及安全性能理想等特点。(The invention belongs to the field of preparation of super capacitors, and particularly relates to a gel electrolyte precursor and application thereof in the aspect of preparing a low-internal-resistance standard solid super capacitor, wherein the gel electrolyte precursor comprises a gel factor, electrolyte salt and an electrolyte solvent; the gel factor comprises a gel monomer and an initiator. The preparation method of the low internal resistance standard solid-state supercapacitor comprises the following steps: (1) assembling the positive pole piece, the negative pole piece and the isolating film into a bare cell, and then putting the bare cell into a shell to obtain a cell to be injected with liquid; (2) injecting the gel electrolyte precursor into the battery cell in vacuum, sealing, placing for 2-5 h, heating at 65-75 ℃ for 2-5 h, and initiating polymerization of the gel monomer; (3) and (4) forming a product, and performing performance test on the prepared low internal resistance standard solid-state supercapacitor. The low internal resistance quasi-solid super capacitor has the characteristics of high conductivity, low internal resistance, ideal cycle and safety performance and the like.)

1. The gel electrolyte precursor is characterized by comprising a gel factor, electrolyte salt and an electrolyte solvent; the gel factor comprises a gel monomer and an initiator; the gel monomer accounts for 1-30% of the gel electrolyte by weight; the initiator accounts for 0.001-5 wt% of the gel electrolyte.

2. The gel electrolyte precursor according to claim 1, wherein: the gel monomer is an acrylamide compound containing a bifunctional group, and the chemical structural formula of the gel monomer is as follows:

wherein R is₁Is H or CH₃；R₂Is H, alkyl or perfluoroalkyl; n is more than or equal to 1 and less than or equal to 50.

3. The gel electrolyte precursor according to claim 2, wherein: the acrylic acid amide compound containing the bifunctional group is prepared by reacting 2- (methyl) acryloyl chloride with double-end amino polyethylene glycol in a reaction solvent; the chemical structural formula of the amino-terminated polyethylene glycol is as follows:

wherein: r is H, alkyl or perfluoroalkyl; n is more than or equal to 1 and less than or equal to 50.

4. A gel electrolyte precursor according to claim 3 wherein: the initiator is one or a mixture of more than two of dibenzoyl peroxide, acetyl peroxide, di-tert-butyl peroxide, azobisisobutyronitrile or azobisisoheptonitrile.

5. The gel electrolyte precursor according to claim 4, wherein: the electrolyte salt is one or a mixture of more than two of triethyl methyl ammonium tetrafluoroborate, tetraethyl ammonium borate, spiro [4,4] quaternary ammonium tetrafluoroborate or spiro [4,5] quaternary ammonium tetrafluoroborate.

6. The gel electrolyte precursor according to claim 5, wherein: the electrolyte solvent is one or a composition of more than two of esters, nitriles or sulfones.

7. The gel electrolyte precursor according to claim 6, wherein: the esters are ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate or ethyl methyl carbonate; the nitrile is acetonitrile, propionitrile, butyronitrile, 3-methoxy propionitrile, glutaronitrile, adiponitrile and the like; the sulfones are dimethyl sulfoxide, methyl ethyl sulfone or sulfolane.

8. The gel electrolyte precursor according to claim 7, wherein: the initiating condition of the initiator is thermal initiation; the temperature of the thermal initiation is 25-100 ℃, and the time is 1-10 h.

9. The application of the gel electrolyte precursor as claimed in any one of claims 1 to 8 in the preparation of low internal resistance solid-state supercapacitors is characterized by comprising the following steps:

(1) assembling the positive pole piece, the negative pole piece and the isolating film into a bare cell, and then putting the bare cell into a shell to obtain a cell to be injected with liquid;

(2) injecting the gel electrolyte precursor into the battery cell in vacuum, sealing, placing for 2-5 h, heating at 65-75 ℃ for 2-5 h, and initiating polymerization of the gel monomer;

(3) and (4) forming a product, and performing performance test on the prepared low internal resistance standard solid-state supercapacitor.

10. Use of the gel electrolyte precursor according to claim 9 for the preparation of low internal resistance solid supercapacitors, characterized in that: the preparation method of the gel electrolyte precursor comprises the following steps:

(1) in a glove box flushed by argon, adding a gel monomer into an electrolyte solvent of electrolyte salt, stirring at room temperature, and fully dissolving;

(2) and (2) adding an initiator into the mixture obtained in the step (1), and stirring and dissolving at room temperature to obtain the precursor of the gel electrolyte.

Technical Field

The invention belongs to the field of super capacitor preparation, and particularly relates to a gel electrolyte precursor and application thereof in preparation of a low-internal-resistance standard solid super capacitor.

Background

A super capacitor (double electric layer capacitor) is a high-energy electric energy storage device developed in recent years, has the advantages of high power density, long cycle life, quick charging and discharging, no pollution to the environment and the like, is widely applied to a backup power source of a motor regulator, a sensor and a microcomputer memory, a starting device of a motor vehicle, a new energy automobile, an urban rail transit system, an intelligent power grid system, a wind power generation and solar power generation system and other clean energy systems, and therefore is receiving attention.

With the development of the energy storage field, higher requirements are also put forward on the super capacitor: higher energy density, higher power density and better safety performance.

In order to solve the potential risks that liquid electrolyte in a super capacitor is easy to pollute and leak, and harms human health, and the like, the all-solid-state polymer electrolyte or the polymer gel electrolyte is applied to the super capacitor to prepare the all-solid-state super capacitor or the quasi-solid-state super capacitor with higher stability, and the method is an effective method for improving the safety performance of the super capacitor at present.

Quasi-solid-state supercapacitors have gained wide attention as new energy storage devices, and gel electrolytes are key technical materials among them. In order to meet the requirements of rapid charge and discharge and high stability of a quasi-solid super capacitor, the development of a novel gel electrolyte with a plurality of advantages of high ionic conductivity, excellent mechanical strength, liquid retention performance and the like is an important scientific problem in the field at present.

The gel electrolyte system fixes the free solvent molecules in the macromolecular gel framework, and the free solvent does not exist or less exists, so that the risk of electrolyte leakage is reduced, the corrosivity and flammability hidden danger of the electrolyte to the whole system are effectively reduced, and the safety performance of the capacitor is improved.

However, supercapacitors using gel electrolytes also have their disadvantages: the electrolyte can not fully wet the active material of the pole piece, and the conductivity of the electrolyte is poorer than that of the liquid electrolyte, so that ions can not fully and freely migrate between the anode and the cathode, and the rapid formation of a double electric layer is influenced, thereby reducing the capacity, deteriorating the high-current charge and discharge performance and the low-temperature charge and discharge performance, and being incapable of meeting the application requirements.

In addition, the non-uniformity of the gel and gassing of the capacitor during activation can lead to poor interface between the positive or negative electrode and the gel electrolyte, possibly rendering part of the active material ineffective, thereby making the capacity and lifetime of the capacitor difficult to achieve design goals.

In recent years, a plurality of chinese patent applications have proposed the preparation method of gel electrolyte related to super capacitor, for example, the application numbers are: 02104183.0, the name is: a patent application of a polymer super capacitor adopting gel polymer electrolyte and a manufacturing method thereof; the application numbers are: 02809248.1, the name is: patent applications for polymer gel electrolyte compositions, polymer gel electrolytes, and secondary batteries and double layer capacitors made from the electrolytes; the application numbers are: 201310044038.4, the name is: patent applications for ionic liquid gel electrolyte systems and supercapacitors containing the same; the application numbers are: 200910048961.9, the name is: a patent application of a carbon-based supercapacitor based on polyacrylamide gel electrolyte and a preparation method thereof; the application numbers are: 201910337106.3, the name is: related patent application of a method for preparing cellulose-based ionic gel electrolyte for supercapacitor. Although the gel electrolyte prepared by the methods realizes the gelation of the liquid electrolyte better, compared with the existing liquid electrolyte super capacitor, the gel electrolyte has low conductivity and large internal resistance, and the performance of the super capacitor adopting the corresponding gel electrolyte still cannot well reach the design target and cannot completely meet the application requirement.

Therefore, how to provide a preparation method of a quasi-solid supercapacitor with high conductivity and low internal resistance, which is simple in manufacturing process, easy to connect with the existing preparation process of a liquid supercapacitor, and simultaneously has excellent electrochemical performance and safety performance, becomes a problem to be solved by the technical staff in the field.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides the gel electrolyte precursor which is low in cost, adjustable in viscosity, suitable for a filling process and easy for realizing large-scale production.

The invention also provides a gel electrolyte precursor and application thereof in preparing a low-internal-resistance standard solid-state supercapacitor. The low internal resistance quasi-solid super capacitor has the characteristics of high conductivity, low internal resistance, ideal cycle and safety performance and the like.

In order to solve the technical problem, the invention is realized as follows:

the gel electrolyte precursor comprises a gel factor, electrolyte salt and an electrolyte solvent; the gel factor comprises a gel monomer and an initiator; the gel monomer accounts for 1-30 wt% of the gel electrolyte, and preferably 3-20 wt%; the initiator accounts for 0.001-5 wt% of the gel electrolyte, and preferably 0.01-3 wt%.

As a preferable scheme, the gel monomer of the invention is an acrylamide compound containing a bifunctional group, and the chemical structural formula of the acrylamide compound is as follows:

wherein R is₁Is H or CH₃；R₂Is H, alkyl or perfluoroalkyl; n is more than or equal to 1 and less than or equal to 50.

Further, the acrylic acid amide compound containing the bifunctional group is prepared by reacting 2- (methyl) acryloyl chloride with double-end amino polyethylene glycol in a reaction solvent; the chemical structural formula of the amino-terminated polyethylene glycol is as follows:

wherein: r is H, alkyl or perfluoroalkyl; n is more than or equal to 1 and less than or equal to 50.

The amino-terminated polyethylene glycol compound can be prepared by the following reaction principle of polyethylene glycol sulfonate and an amine compound according to a reference method ((a) preparation and characterization of Gongqinmei, pennshirong, Zhang Xia, amino-terminated polyethylene glycol, China medical industry journal, 2003, volume 34, No. 10, No. 490, 492), (b) synthesis of macrovier, Nahaili, high rock epitaxy, royal jelly, Wang Juanmin, amino-terminated polyethylene glycol, chemical intermediates, 2011, No. 5, 49-51 and the like).

Wherein: r is H, alkyl or perfluoroalkyl, R' is methyl or aryl, and n is more than or equal to 1 and less than or equal to 50.

Further, the initiator is one or a mixture of more than two of dibenzoyl peroxide, acetyl peroxide, di-tert-butyl peroxide, azobisisobutyronitrile or azobisisoheptonitrile.

Furthermore, the electrolyte salt is one or a mixture of more than two of triethyl methyl ammonium tetrafluoroborate, tetraethyl ammonium borate, spiro [4,4] quaternary ammonium tetrafluoroborate or spiro [4,5] quaternary ammonium tetrafluoroborate.

Furthermore, the electrolyte solvent is a composition of one or more than two of esters, nitriles or sulfones.

Further, the esters of the invention are ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate or ethyl methyl carbonate; the nitrile is acetonitrile, propionitrile, butyronitrile, 3-methoxy propionitrile, glutaronitrile, adiponitrile and the like; the sulfones are dimethyl sulfoxide, methyl ethyl sulfone or sulfolane.

Further, the initiating condition of the initiator is thermal initiation; the temperature of the thermal initiation is 25-100 ℃, and the time is 1-10 h.

The application of the gel electrolyte precursor in the aspect of preparing the low-internal-resistance standard solid-state supercapacitor comprises the following steps:

(1) assembling the positive pole piece, the negative pole piece and the isolating film into a bare cell, and then putting the bare cell into a shell to obtain a cell to be injected with liquid;

(2) injecting the gel electrolyte precursor into the battery cell in vacuum, sealing, placing for 2-5 h, heating at 65-75 ℃ for 2-5 h, and initiating polymerization of the gel monomer;

(3) and (4) forming a product, and performing performance test on the prepared low internal resistance standard solid-state supercapacitor.

As a preferable scheme, the preparation method of the gel electrolyte precursor of the invention comprises the following steps:

(1) in a glove box flushed by argon, adding a gel monomer into an electrolyte solvent of electrolyte salt, stirring at room temperature, and fully dissolving;

(2) and (2) adding an initiator into the mixture obtained in the step (1), and stirring and dissolving at room temperature to obtain the precursor of the gel electrolyte.

At least one of the acrylamide compounds containing the bifunctional groups is used as a gel electrolyte formed by a gel monomer, the liquid electrolyte solvent is coated and locked through the interaction between a high molecular chain segment and the liquid electrolyte solvent, the quasi-solid electrolyte, an electrode material and a diaphragm are well wetted, and the contact resistance is effectively reduced. Therefore, compared with a liquid electrolyte super capacitor, the gel electrolyte super capacitor has high conductivity, low internal resistance and more excellent cycle performance and safety performance. Secondly, the viscosity of the gel electrolyte is adjustable, so that the gel electrolyte is suitable for a perfusion process; finally, the quasi-solid super capacitor is simple in preparation process, low in cost and easy to realize large-scale production.

Detailed Description

The present invention will be further illustrated by the following examples, but the present invention is not limited to these examples.

Reference example 1

Bis (N-perfluorooctyl-N-triethylene glycol) amine (492g,0.5mol) and triethylamine (131g,1.3mol) were added to 2000 ml of toluene, respectively, at room temperature, and then 2-methacryloyl chloride (117g,1.1mol) was added dropwise to the solution over 30 minutes with stirring. After the addition was completed, the reaction was carried out at room temperature for 15 hours. Filtering, collecting filtrate, concentrating to remove toluene, separating by flash column chromatography, and purifying to obtain bifunctional methacrylamide with yield of 92%.

Molecular weight by mass spectrometry analysis: MS (ESI) M/z 1121[ M + H ]]⁺.

By nuclear magnetic resonance spectroscopy analysis, hydrogen spectrum data are measured:¹H NMR(CDCl₃,400MHz)δ:5.93(m,2H),5.42(m,2H),3.57-3.63(m,4H),3.51(t,J＝5.2Hz,4H)，2.85(t,J＝5.1Hz,4H),1.02(s,6H).

reference example 2

Bis (N-perfluorobutyl-N-triethylene glycol) amine (292g,0.5mol) and triethylamine (131g,1.3mol) were added to 1500 ml of toluene, respectively, at room temperature, and then 2-methacryloyl chloride (117g,1.1mol) was added dropwise to the solution over 30 minutes with stirring. After the addition, the reaction was carried out at room temperature for 12 hours. Filtering, collecting filtrate, concentrating to remove toluene, separating by flash column chromatography, and purifying to obtain bifunctional methacrylamide with yield of 86%.

Molecular weight by mass spectrometry analysis: MS (ESI) M/z 721[ M + H]⁺.

By nuclear magnetic resonance spectroscopy analysis, hydrogen spectrum data are measured:¹H NMR(CDCl₃,400MHz)δ:5.93(m,2H),5.42(m,2H),3.57-3.63(m,4H),3.51(t,J＝5.2Hz,4H)，2.85(t,J＝5.1Hz，4H),1.97(s,6H).

reference example 3

Bis (N-perfluorobutyl-N-triethylene glycol) amine (292g,0.5mol) and triethylamine (131g,1.3mol) were added to 1200 ml of toluene, respectively, at room temperature, and then acryloyl chloride (99g,1.1mol) was added dropwise to the solution over 30 minutes with stirring. After the addition, the reaction was carried out at room temperature for 12 hours. Filtering, collecting filtrate, concentrating to remove toluene, separating by flash column chromatography, and purifying to obtain bifunctional methacrylamide with yield of 93%.

Molecular weight by mass spectrometry analysis: MS (ESI) M/z 693[ M + H ]]⁺.

By nuclear magnetic resonance spectroscopy analysis, hydrogen spectrum data are measured:¹H NMR(CDCl₃,400MHz)δ:6.52(m,2H),5.96(m,2H),5.46(m,2H),3.59-3.65(m,4H),3.53(t,J＝5.2Hz,4H),2.90(t,J＝5.1Hz,4H).

reference example 4

Bis (N-perfluorooctyl-N-triethylene glycol) amine (492g,0.5mol) and triethylamine (131g,1.3mol) were added to 2000 ml of toluene, respectively, at room temperature, and then acryloyl chloride (99g,1.1mol) was added dropwise to the solution over 30 minutes with stirring. After the addition, the reaction was carried out at room temperature for 12 hours. Filtering, collecting filtrate, concentrating to remove toluene, separating by flash column chromatography, and purifying to obtain bifunctional methacrylamide with yield of 87%.

Molecular weight by mass spectrometry analysis: MS (ESI) M/z 1093[ M + H ]]⁺.

By nuclear magnetic resonance spectroscopy analysis, hydrogen spectrum data are measured:¹H NMR(CDCl₃,400MHz)δ:6.48(m,2H),5.90(m,2H),5.44(m,2H),3.54-3.63(m,4H),3.55(t,J＝5.2Hz,4H),2.87(t,J＝5.1Hz,4H).

reference example 5

Triethylene glycol diamine (29.2g,0.2mol) and triethylamine (51g,0.5mol) were added to 500 ml of toluene at room temperature, respectively, and then 2-methacryloyl chloride (42g,0.41mol) was added dropwise to the solution over 30 minutes with stirring. After the addition, the reaction was carried out at room temperature for 8 hours. Filtering, collecting filtrate, concentrating to remove toluene, separating by flash column chromatography, and purifying to obtain bifunctional methacrylamide with yield of 92%.

Molecular weight by mass spectrometry analysis: MS (ESI) M/z 285[ M + H ]]⁺.

By nuclear magnetic resonance spectroscopy analysis, hydrogen spectrum data are measured:¹H NMR(CDCl₃,400MHz)δ:8.2(s,2H),6.01(m,2H),5.47(m,2H),3.55-3.59(m,4H),3.46(t,J＝5.2Hz,4H),2.85(t,J＝5.1Hz,4H),1.87(s,6H).

reference example 6

Pentaethyleneglycol diamine (70.2g,0.3mol) and triethylamine (71g,0.7mol) were added to 1000 ml of toluene, respectively, at room temperature, and then 2-methacryloyl chloride (65g,0.61mol) was added dropwise to the solution over 30 minutes with stirring. After the addition, the reaction was carried out at room temperature for 10 hours. Filtering, collecting filtrate, concentrating to remove toluene, separating by flash column chromatography, and purifying to obtain bifunctional methacrylamide with yield of 90%.

Molecular weight by mass spectrometry analysis: MS (ESI) M/z 373[ M + H ]]⁺.

By nuclear magnetic resonance spectroscopy analysis, hydrogen spectrum data are measured:¹H NMR(CDCl₃,400MHz)δ:8.2(s,2H),6.03(m,2H),5.48(m,2H),3.53-3.64(m,12H),3.45(t,J＝5.2Hz,4H),2.83(t,J＝5.1Hz,4H),1.84(s,6H).