Self-repairing ionic gel electrolyte, zinc ion battery as well as preparation method and application of self-repairing ionic gel electrolyte and zinc ion battery

Abstract

The invention relates to a self-repairing ionic gel electrolyte, a zinc ion battery and a preparation method and application of the self-repairing ionic gel electrolyte and the zinc ion battery. The ionic gel electrolyte comprises a polymer network, ionic liquid (1-ethyl-3-methylimidazolium tetrafluoroborate) and movable zinc ions, the polymer network is obtained through a reaction of an anionic monomer 2-acrylamido-2-methyl sodium propanesulfonate and a cationic monomer acryloyloxyethyl trimethyl ammonium chloride, and the movable zinc ions are provided by a zinc tetrafluoroborate hydrate. The zinc ion battery takes the ionic gel as an electrolyte, and a positive film electrode and a negative film electrode are arranged on two sides of the ionic gel. Compared with the prior art, the material not only has excellent mechanical properties and efficient ion transmission capability, but also has the capability of quickly repairing mechanical damage, and the completely broken material can be completely repaired after being contacted for 10 seconds under infrared light irradiation. The prepared zinc ion battery has excellent self-repairing performance, flexible performance and electrochemical performance.

Description

Technical Field

[0001] The present invention relates to the technical field of flexible energy storage devices, and in particular to a self-repairing ion gel electrolyte, a zinc ion battery, and a preparation method and application thereof. Background Art

[0002] In recent years, the rapid development of flexible electronic technology has greatly promoted the growth of demand for flexible and wearable energy storage systems. As a highly promising energy storage device, zinc-ion batteries have shown broad application prospects in the fields of flexible electronics and wearable devices due to their excellent safety, significant cost advantages and excellent environmental compatibility. However, traditional zinc-ion batteries face key challenges such as electrolyte leakage risk, insufficient mechanical properties, and poor interface stability. In particular, their electrochemical performance often shows significant attenuation under extreme conditions (such as bending, high temperature or low temperature environments). Zinc-ion batteries based on gel electrolytes have become an ideal choice to meet the needs of flexible energy storage due to their excellent flexibility and functionality. However, the traditional gel electrolytes currently widely used generally have inherent defects such as single structure and function and insufficient mechanical properties. Therefore, the development of new gel electrolyte systems with multiple functional properties has become a key breakthrough in promoting the development of flexible energy storage technology. More importantly, it is difficult for existing electrolyte materials to simultaneously achieve core indicators such as high ionic conductivity, excellent self-healing properties and excellent interface compatibility.

[0003] Ionic liquids, specialized liquid substances composed entirely of ions, exhibit numerous remarkable properties, including extremely high ionic conductivity, a wide electrochemical window, extremely low volatility, and excellent thermal stability. Ion gel electrolytes developed based on ionic liquids not only perfectly inherit these excellent properties but also possess exceptional mechanical stability and flexibility, effectively inhibiting the growth of zinc dendrites and significantly improving battery safety.

[0004] From a biomimetic perspective, damage repair and functional recovery are crucial to the survival of organisms. Inspired by this, the development of artificial materials with self-repairing mechanical properties and intelligent functions has important scientific significance and application value. With the vigorous development of polymer science and supramolecular chemistry, researchers have successfully developed intelligent self-healing materials with multiple functions such as elastic response, sensing properties, super-hydrophobic surfaces, conductive properties and color change capabilities (intelligent self-healing materials can repair damage (such as cracks, fractures) autonomously or under specific conditions (such as heating, light) and restore structural or functional integrity.). Of particular note, self-healing ion gels are prepared by loading ionic liquids into polymer networks cross-linked by reversible covalent bonds or dynamic non-covalent bonds. The reversible properties of these dynamic chemical bonds enable ion gels to spontaneously rebuild their network structure after damage, completely restoring their original structural integrity and functional properties. At present, self-healing ion gels have shown great application potential in cutting-edge fields such as energy storage devices, power generation devices and strain sensors.

[0005] For example, patent CN115386041A uses a combination of N-acryloylglycineamide, comonomer, zinc salt and ionic liquid to prepare an ion gel with excellent elasticity, self-healing performance (self-repair), high ionic conductivity and excellent wide temperature range applicability. However, the ion gel in this patent needs to be self-healed at room temperature (25°C) for 24 hours after water stimulation to achieve a self-healing efficiency of 93%, and its self-healing performance still needs to be improved. Patent CN112599863A discloses a repairable ion gel electrolyte and its zinc ion battery. The ion gel electrolyte is a polymer ion gel generated by the reaction of N, N-dimethylacrylamide monomer in the ionic liquid 1-butyl-3-methylimidazolium trifluoromethanesulfonate. It can achieve high-efficiency repair performance under infrared light conditions and has high tensile strength, but the ionic conductivity of the polymer ion gel is only 0.96mS cm -1 The zinc ion battery prepared by using the polymer ion gel has a high performance at 0.8Ag -1 At the current density, its initial discharge capacity is 206.4 mAh g -1 , the electrochemical performance of its battery still needs to be improved. Summary of the Invention

[0006] The purpose of the present invention is to provide a self-repairing ion gel electrolyte, a zinc ion battery and its preparation method and application. The ion gel electrolyte has excellent mechanical properties, ionic conductivity and efficient self-repairing performance. The zinc ion battery prepared based on the ion gel electrolyte has excellent self-repairing performance, flexibility, rate and cycle performance.

[0007] The purpose of the present invention can be achieved by the following technical solutions:

[0008] One of the objectives of the present invention is to provide a self-healing ion gel electrolyte, comprising a polymer network and an ionic liquid and movable zinc ions encapsulated within the polymer network. The polymer network is obtained by reacting an anionic monomer 2-acrylamido-2-methylpropanesulfonic acid sodium and a cationic monomer acryloyloxyethyltrimethylammonium chloride. The ionic liquid comprises 1-ethyl-3-methylimidazolium tetrafluoroborate, and the movable zinc ions are provided by zinc tetrafluoroborate hydrate.

[0009] The invention uses anionic monomer 2-acrylamido-2-methylpropanesulfonate sodium (AMPS-Na) and cationic monomer acryloyloxyethyltrimethylammonium chloride (DMAEA-Q) as raw materials to synthesize a cross-linked polymer network that wraps an ionic liquid inside, and the network structure has a high cross-linking density.

[0010] A second object of the present invention is to provide a method for preparing the self-healing ion gel electrolyte, comprising the following steps:

[0011] S1: dispersing and dissolving zinc tetrafluoroborate hydrate in 1-ethyl-3-methylimidazolium tetrafluoroborate, stirring and ultrasonicating to obtain a dispersion;

[0012] S2: Acryloyloxyethyltrimethylammonium chloride (DMAEA-Q) and sodium 2-acrylamido-2-methylpropanesulfonate (AMPS-Na) are added to the dispersion in sequence and stirred to dissolve, followed by the addition of a crosslinker N,N′-methylenebisacrylamide and an initiator α-ketoglutaric acid. After stirring evenly, a crosslinking reaction is carried out under ultraviolet light to obtain the self-healing ion gel electrolyte.

[0013] Preferably, the mass ratio of the sodium 2-acrylamide-2-methylpropanesulfonate, acryloyloxyethyltrimethylammonium chloride and 1-ethyl-3-methylimidazolium tetrafluoroborate is 0.1165-0.4276:0.4432-1.1640:1.

[0014] Preferably, the mass ratio of the zinc tetrafluoroborate hydrate to 1-ethyl-3-methylimidazolium tetrafluoroborate is 0.2-0.8:1.

[0015] Preferably, the mass ratio of the N,N′-methylenebisacrylamide, α-ketoglutaric acid and 1-ethyl-3-methylimidazolium tetrafluoroborate is 0.0001-0.0027:0.0125-0.0315:1.

[0016] Preferably, in step S1, the stirring time is 20-30 min, the stirring rate is 100-1000 rpm, the ultrasonic time is 5-30 min, and the ultrasonic frequency is 10-60 kHz.

[0017] Preferably, in step S2, the stirring rate after adding acryloyloxyethyltrimethylammonium chloride and sodium 2-acrylamido-2-methylpropanesulfonate is 100-1000 rpm, and the stirring time is 20-60 min.

[0018] Preferably, in step S2, the stirring rate after adding the cross-linking agent N,N′-methylenebisacrylamide and the initiator α-ketoglutaric acid is 100-1000 rpm, and the stirring time is 20-60 min.

[0019] Preferably, in step S2, the cross-linking reaction under ultraviolet light specifically refers to: irradiating under ultraviolet light with a wavelength of 365 nm, and reacting for 8 to 24 hours.

[0020] Preferably, the α-ketoglutaric acid is used as an initiator to decompose free radicals, thereby initiating an in-situ free radical copolymerization reaction between acryloyloxyethyltrimethylammonium chloride and sodium 2-acrylamido-2-methylpropanesulfonate monomers to obtain the ion gel electrolyte.

[0021] A third object of the present invention is to provide a zinc ion battery, comprising the self-repairing ion gel electrolyte, a positive thin film electrode and a negative thin film electrode arranged on both sides of the self-repairing ion gel electrolyte, the positive thin film electrode and the negative thin film electrode being connected by copper wire, and the positive thin film electrode and the negative thin film electrode being connected to the copper wire by silver glue.

[0022] Preferably, the positive thin film electrode is a carbon nanotube / polyaniline thin film electrode, and the negative thin film electrode is a carbon nanotube / zinc thin film electrode.

[0023] Preferably, the copper wires are connected to the ends of the positive and negative thin film electrodes.

[0024] Preferably, in the carbon nanotube / polyaniline film electrode and the carbon nanotube / zinc film electrode, the size of the carbon nanotube film is 1-3 mm×20-30 mm.

[0025] Preferably, the carbon nanotube / polyaniline thin film electrode is obtained by in-situ growing polyaniline on the surface of the carbon nanotube film using a chemical oxidation polymerization method.

[0026] Preferably, the method for preparing the carbon nanotube / polyaniline film electrode comprises the following steps:

[0027] (1) In an ice bath, aniline monomer and ammonium persulfate are added to perchloric acid in sequence, and stirred to obtain a mixed solution;

[0028] (2) Then, the plasma-treated carbon nanotube film is immersed in the mixed solution and allowed to react at low temperature.

[0029] Preferably, the temperature of the ice bath is 0-6°C.

[0030] Preferably, the concentration of perchloric acid is 0.8-1.2M, more preferably 1M.

[0031] Preferably, in the perchloric acid, the added amount of aniline monomer is 0.0006-0.0012 g / mL, and the added amount of ammonium persulfate is 0.0013-0.0033 g / mL.

[0032] Preferably, the stirring rate is 200-600 rpm and the time is 10-30 min.

[0033] Preferably, the plasma treatment is performed under N2 atmosphere, the power of the plasma treatment is 200-280W, and the time of the plasma treatment is 2-5 minutes.

[0034] Further preferably, the power of the plasma treatment is 240 W, and the time of the plasma treatment is 3 minutes.

[0035] Preferably, the low-temperature static reaction refers to a static reaction at a low temperature environment of 0-6°C for 8-16 hours, more preferably a static reaction at a low temperature environment of 4°C for 12 hours.

[0036] Preferably, the carbon nanotube / zinc film electrode is obtained by depositing zinc on the surface of the carbon nanotube film using an electrochemical deposition method.

[0037] Preferably, the preparation method of the carbon nanotube / zinc film electrode comprises the following steps: using zinc sulfate solution as electrolyte, carbon nanotube film as working electrode, and zinc sheet as counter electrode to form a two-electrode system, and conducting the electrochemical reaction at -5--15 mAcm -2 Deposition was carried out for 20-40 min at a current density of 1.5 Å.

[0038] Further preferably, the concentration of the zinc sulfate solution is 0.8-1.2M, and further preferably 1M.

[0039] Further preferably, the parameters of electrochemical deposition are -10 mA cm -2 The deposition was carried out at a current density of 30 min.

[0040] A fourth object of the present invention is to provide an application of the zinc ion battery in a flexible energy storage device.

[0041] The ion gel of the present invention is obtained by in-situ free radical copolymerization of acryloyloxyethyl trimethyl ammonium chloride and 2-acrylamide-2-methyl propane sulfonate monomers. Since the molecular structures of acryloyloxyethyl trimethyl ammonium chloride and 2-acrylamide-2-methyl propane sulfonate monomers have abundant anions and cations (NH 4+ and SO42- ), when the ion gel is damaged by external force, the broken surfaces are re-contacted, and the electrostatic attraction between the anions and cations will prompt the broken surfaces to quickly recombine and restore their original structure and function. - , which can be hydrolyzed to generate a large amount of H + , greatly improving its ionic conductivity. At the same time, thanks to the rapid redox reaction on the polyaniline (PANI) positive electrode surface and the multi-component synergistic effect of the solid interface layer on the zinc negative electrode surface (ZnS inhibits dendrites and ZnF2 promotes ion conduction), the prepared full battery (zinc ion battery) has extremely high rate and excellent cycle performance.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] (1) The present invention obtains a polymer network structure by reacting an anionic monomer 2-acrylamido-2-methylpropanesulfonate and a cationic monomer acryloyloxyethyltrimethylammonium chloride, and encapsulates an ionic liquid 1-ethyl-3-methylimidazolium tetrafluoroborate and mobile zinc ions therein, thereby preparing an ion gel electrolyte having excellent mechanical properties, ionic conductivity, and efficient self-healing properties.

[0044] (2) The ion gel electrolyte of the present invention has the ability to quickly repair mechanical damage, showing 100% repair efficiency under heating or infrared light conditions, and even complete repair can be achieved in just 10 seconds under near-infrared light (808nm) conditions.

[0045] (3) The ion gel electrolyte of the present invention also exhibits excellent repair stability. After 10 fracture / repair cycles, the conductivity of the ion gel still remains at 10.2 mS cm -1 high level.

[0046] (4) The ion gel electrolyte of the present invention has excellent mechanical properties (elongation up to 802%, tensile strength of 34kPa), and efficient ion transport capability (ionic conductivity can reach up to 13.6mS cm -1 ).

[0047] (5) The present invention also provides a zinc ion battery prepared based on the ion gel electrolyte, which has excellent rate performance and cycle stability. -1 It can release 300mAh g at a current density of -1 When the current density is increased to 100Ag -1 When the capacity retention rate is as high as 33.4%, the coulombic efficiency is always maintained above 99.5%. -1It can still operate stably at extremely high current density; at 100Ag -1 It can still maintain 80% of its capacity after 3500 cycles at a high current density, far exceeding the existing technical indicators.

[0048] (6) The zinc ion battery provided by the present invention has excellent flexibility and self-healing performance, can maintain a high specific capacity at any bending angle, and has almost no capacity decay after 5000 repeated bendings, and still maintains 90% of the capacity after 7 fracture / repair cycles.

[0049] (7) The structure and preparation process of the self-repairing zinc ion battery of the present invention are relatively simple, and it has broad application prospects in portable flexible and wearable devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 Schematic diagram of the synthesis of the ion gel electrolyte and the dynamic cross-linking mechanism of the present invention.

[0051] Figure 2 The figures are the changes in mechanical strength of the ion gel electrolyte of the present invention before and after repair at room temperature, high temperature and infrared light irradiation.

[0052] Figure 3 The ionic conductivity of the ion gel electrolyte of the present invention after being repaired for different times.

[0053] Figure 4 It is the capacity retention rate of the zinc ion battery of the present invention at different bending angles.

[0054] Figure 5 It is the capacity retention rate of the zinc ion battery of the present invention during multiple cyclic bending processes.

[0055] Figure 6 It is the capacity retention rate of the zinc ion battery of the present invention after different repair times under 808nm near-infrared light conditions.

[0056] Figure 7 It is the rate performance of the zinc ion battery of the present invention.

[0057] Figure 8 It is the cycle performance of the zinc ion battery of the present invention.

[0058] Figure 9 The figure shows the rate performance of the zinc ion batteries of Example 1 and Comparative Example 2 of the present invention.

[0059] Figure 10 The figure shows the rate performance of the zinc ion batteries of Example 1 and Comparative Example 3 of the present invention. DETAILED DESCRIPTION

[0060] This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0061] A self-healing ion gel electrolyte, such as Figure 1 As shown, it includes a polymer network and an ionic liquid and a movable zinc ion coated inside the polymer network, wherein the polymer network is obtained by reacting an anionic monomer 2-acrylamido-2-methylpropanesulfonate sodium and a cationic monomer acryloyloxyethyltrimethylammonium chloride, the ionic liquid includes 1-ethyl-3-methylimidazolium tetrafluoroborate, and the movable zinc ion is provided by zinc tetrafluoroborate hydrate;

[0062] The preparation method of the self-repairing ion gel electrolyte is as follows:

[0063] S1: dispersing and dissolving zinc tetrafluoroborate hydrate in 1-ethyl-3-methylimidazolium tetrafluoroborate, stirring and ultrasonicating to obtain a dispersion;

[0064] S2: Acryloyloxyethyltrimethylammonium chloride (DMAEA-Q) and sodium 2-acrylamido-2-methylpropanesulfonate (AMPS-Na) are added to the dispersion in sequence and stirred to dissolve, followed by the addition of a crosslinker N,N′-methylenebisacrylamide and an initiator α-ketoglutaric acid. After stirring evenly, a crosslinking reaction is carried out under ultraviolet light to obtain the self-healing ion gel.

[0065] A zinc ion battery comprises the self-repairing ion gel electrolyte, a positive thin film electrode and a negative thin film electrode arranged on both sides of the self-repairing ion gel electrolyte, wherein the positive thin film electrode and the negative thin film electrode are connected by copper wires, and the positive thin film electrode and the negative thin film electrode are connected to the copper wires via silver glue, the positive thin film electrode is a carbon nanotube / polyaniline thin film electrode, and the negative thin film electrode is a carbon nanotube / zinc thin film electrode.

[0066] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0067] Unless otherwise specified, the reagents, methods, instruments and equipment used in the present invention are conventional reagents, methods, instruments and equipment in the art. Unless otherwise specified, the reagents and materials used in the following examples are commercially available.

[0068] The carbon nanotube films used in the following examples were purchased from JCMW CFM-10, multi-walled.

[0069] The acryloyloxyethyltrimethylammonium chloride monomer used in the following examples is an aqueous solution of the monomer with a volume fraction of 80%.

[0070] Example 1

[0071] A method for preparing a self-repairing ion gel polyelectrolyte and a flexible zinc ion battery, comprising the following steps:

[0072] Step 1: Dissolve 0.8 g of zinc tetrafluoroborate hydrate in 1.6 mL of 1-ethyl-3-methylimidazolium tetrafluoroborate, stir continuously for 20 minutes, and ultrasonicate for 5 minutes.

[0073] Step 2: 0.64 mL of acryloyloxyethyltrimethylammonium chloride monomer and 0.55 mL of 2-acrylamido-2-methylpropanesulfonic acid sodium salt monomer were added in sequence and stirred for 20 minutes.

[0074] Step 3: 2.9 mg of N,N'-methylenebisacrylamide as a crosslinker and 37.6 mg of α-ketoglutaric acid as an initiator were then added to the mixture in step 2, stirred for 30 minutes, and ultrasonicated for 10 minutes respectively.

[0075] Step 4: Place the copolymer mixture obtained in step 3 under ultraviolet light for 8 hours to obtain a polyion gel.

[0076] Step 5: In situ growth of polyaniline on the surface of the carbon nanotube film was performed using chemical oxidation polymerization. The carbon nanotube film was sized at 2 mm x 25 mm. The specific steps were as follows: Aniline monomer and ammonium persulfate were added to 1 M perchloric acid in an ice bath. The solution was stirred continuously for 30 minutes to ensure uniform dispersion. The plasma-treated carbon nanotube film was then immersed in the solution and allowed to react at 4°C for 12 hours.

[0077] Step 6: Electrochemical deposition of zinc on the surface of the carbon nanotube film. The size of the carbon nanotube film is about 2mm×25mm. The specific steps are as follows: 1M zinc sulfate solution is used as the electrolyte, the carbon nanotube film is used as the working electrode, and the zinc sheet is used as the counter electrode to form a two-electrode system. -2 The deposition was carried out at a current density of 30 min.

[0078] Step 7: Connect the ends of the composite film electrodes obtained in steps 5 and 6 to copper wires with silver glue, and cover both sides of the ion gel membrane obtained in step 4, thereby obtaining a zinc ion battery.

[0079] Example 2

[0080] A method for preparing a self-repairing ion gel polyelectrolyte and its application in a flexible zinc ion battery, comprising the following steps:

[0081] Step 1: Dissolve 0.8 g of zinc tetrafluoroborate hydrate in 1.6 mL of 1-ethyl-3-methylimidazolium tetrafluoroborate, stir continuously for 20 minutes, and ultrasonicate for 5 minutes.

[0082] Step 2: 1.09 mL of acryloyloxyethyltrimethylammonium chloride monomer and 0.55 mL of 2-acrylamido-2-methylpropanesulfonic acid sodium salt monomer were added in sequence and stirred for 20 minutes.

[0083] Step 3: Then, 4.4 mg of N,N'-methylenebisacrylamide as a crosslinker and 56.7 mg of α-ketoglutaric acid as an initiator were added to the mixture in step 2 in sequence, and stirred for 30 minutes and ultrasonicated for 10 minutes respectively.

[0084] Step 4: Place the copolymer obtained in step 3 under ultraviolet light for 12 hours to obtain a polyion gel.

[0085] Step 5: In situ growth of polyaniline on the surface of the carbon nanotube film was performed using chemical oxidation polymerization. The carbon nanotube film was approximately 2 mm x 25 mm in size. The specific steps were as follows: Aniline monomer and ammonium persulfate were added to 1 M perchloric acid in an ice bath. The solution was stirred continuously for 30 minutes to ensure uniform dispersion. The plasma-treated carbon nanotube film was then immersed in the solution and allowed to react at 4°C for 12 hours.

[0086] Step 6: Electrochemical deposition of zinc on the surface of the carbon nanotube film. The size of the carbon nanotube film is about 2mm×25mm. The specific steps are as follows: 1M zinc sulfate solution is used as the electrolyte, the carbon nanotube film is used as the working electrode, and the zinc sheet is used as the counter electrode to form a two-electrode system. -2 The deposition was carried out at a current density of 30 min.

[0087] Step 7: Connect the ends of the composite film electrodes obtained in steps 5 and 6 to copper wires with silver glue, and cover both sides of the ion gel membrane obtained in step 4, thereby obtaining a zinc ion battery.

[0088] Example 3

[0089] A method for preparing a self-repairing ion gel polyelectrolyte and its application in a flexible zinc ion battery, comprising the following steps:

[0090] Step 1: Dissolve 0.8 g of zinc tetrafluoroborate hydrate in 1.95 mL of 1-butyl-3-methylimidazolium tetrafluoroborate, stir continuously for 30 minutes, and ultrasonicate for 10 minutes.

[0091] Step 2: 0.64 mL of acryloyloxyethyltrimethylammonium chloride monomer and 0.55 mL of 2-acrylamido-2-methylpropanesulfonic acid sodium salt monomer were added in sequence and stirred for 20 minutes.

[0092] Step 3: 6.0 mg of N,N'-methylenebisacrylamide as a crosslinker and 37.6 mg of α-ketoglutaric acid as an initiator were then added to the mixture in step 2, stirred for 30 minutes, and ultrasonicated for 10 minutes, respectively.

[0093] Step 4: Place the copolymer obtained in step 3 under ultraviolet light for 15 hours to obtain a polyion gel.

[0094] Step 5: In situ growth of polyaniline on the surface of the carbon nanotube film was performed using chemical oxidation polymerization. The carbon nanotube film was approximately 2 mm x 25 mm in size. The specific steps were as follows: Aniline monomer and ammonium persulfate were added to 1 M perchloric acid in an ice bath. The solution was stirred continuously for 30 minutes to ensure uniform dispersion. The plasma-treated carbon nanotube film was then immersed in the solution and allowed to react at 4°C for 12 hours.

[0095] Step 6: Electrochemical deposition of zinc on the surface of the carbon nanotube film. The size of the carbon nanotube film is about 2mm×25mm. The specific steps are as follows: 1M zinc sulfate solution is used as the electrolyte, the carbon nanotube film is used as the working electrode, and the zinc sheet is used as the counter electrode to form a two-electrode system. -2 The deposition was carried out at a current density of 30 min.

[0096] Step 7: Connect the ends of the composite film electrodes obtained in steps 5 and 6 to copper wires with silver glue, and cover both sides of the ion gel membrane obtained in step 4, thereby obtaining a zinc ion battery.

[0097] The ion gel electrolyte prepared in step 4 of Example 1 was cut and subjected to heating or infrared light irradiation to test the tensile properties of the ion gel before and after treatment. The test results are as follows: Figure 2 As shown, the elongation is as high as 802% and the tensile strength is 34kPa.

[0098] The ion gel was cut and then joined together. Under infrared light (808 nm), it took only 10 seconds to fully repair. The cut / repaired ion gel still had high conductivity. After 10 cycles of breaking / repairing, the conductivity of the ion gel remained at 10.2 mS cm. -1 High level ( Figure 3 ).

[0099] The electrochemical performance of the zinc ion battery prepared in step 7 of Example 1 was tested. Figure 7 and 8 are the rate performance and cycle performance of the zinc ion battery respectively. Figure 7 It can be seen that the zinc ion battery has a -1 It can release 300mAhg at a current density of -1Even when the current density is increased to 100Ag -1 When the capacity retention rate is as high as 33.4%, the coulombic efficiency is always maintained above 99.5%. -1 It can still operate stably under extremely high current density. Figure 8 It can be seen that at 100Ag -1 It can still maintain 80% of its capacity after 3500 cycles at a high current density, far exceeding the existing technical indicators.

[0100] The electrochemical performance of the zinc ion battery prepared in step 7 of Example 1 was tested at different bending angles and the electrochemical performance of the battery after repeatedly bending it to 180 degrees. Figure 4 and Figure 5 As shown, the zinc-ion battery can maintain a high specific capacity at any bending angle and maintain excellent flexibility. After 5,000 repeated bendings, the capacity has almost no attenuation, and the coulombic efficiency has almost no attenuation during the entire bending process, maintaining above 99.5%.

[0101] The zinc ion battery can be repaired by cutting it and then connecting it together under infrared light (808nm). Figure 6 As shown, 90% of the capacity is retained after 7 fracture / repair cycles.

[0102] Comparative Example 1

[0103] A repairable ion gel electrolyte and zinc ion battery. The ion gel electrolyte is a polymer ion gel formed by reacting N,N-dimethylacrylamide monomers in the ionic liquid 1-butyl-3-methylimidazolium trifluoromethanesulfonate. The polymer ion gel uses N,N'-methylenebisacrylamide as a crosslinker, α-ketoglutaric acid as a UV initiator, and zinc trifluoromethanesulfonate as a source of mobile zinc ions. The zinc ion battery uses the ion gel as the electrolyte, a carbon nanotube / polyaniline film as the positive electrode material, and a carbon nanotube / zinc film as the negative electrode material. Its preparation method is based on patent CN112599863A.

[0104] The ionic conductivity of the ion gel electrolyte in Comparative Example 1 is only 0.96 mS cm -1 The zinc ion battery prepared by using the polymer ion gel has a high performance at 0.8Ag -1 At the current density, its initial discharge capacity is 206.4 mAh g -1 After 10 cycles of fracture / repair, the conductivity of the ion gel electrolyte prepared in Example 1 of the present invention remained at 10.2 mS cm -1 The high level of zinc-ion batteries at 5Ag -1 It can release 300mAh g at a current density of-1 When the current density is increased to 100Ag -1 When the capacity retention rate is as high as 33.4%, it shows a high rate performance. Therefore, the ion transport capacity and electrochemical performance of the battery of the ion gel of the present invention are much higher than those of the comparative example 1.

[0105] Comparative Example 2

[0106] The anionic and cationic monomers in Example 1 were replaced with equimolar amounts of nonionic monomer N,N'-dimethylacrylamide (DMAAm). The rest was the same as in Example 1. Nonionic gel was synthesized from DMAAm and Zn|PANI battery was assembled. The battery was heated at 30Ag. -1 At current densities of 100 mAh and higher, its discharge capacity is less than 100 mAh g -1 , the performance is far lower than that of the ion gel in the present invention (such as Figure 9 ).

[0107] Comparative Example 3

[0108] The molar ratios of the anionic monomer 2-acrylamido-2-methylpropanesulfonate and the cationic monomer acryloyloxyethyltrimethylammonium chloride in Example 1 were changed to 1:2, 1:3, 2:1, and 3:1, respectively. The rest was the same as in Example 1. Four different ion gels were synthesized and Zn|PANI batteries were assembled. The four batteries were tested at 5-100Ag. -1 In the current density range, the rate performance is lower than that of the battery with the original ratio in Example 1 (such as Figure 10 ).

[0109] The above description of the embodiments is intended to facilitate understanding and use of the invention by those skilled in the art. It will be apparent that those skilled in the art can readily make various modifications to these embodiments and apply the general principles described herein to other embodiments without requiring inventive effort. Therefore, the present invention is not limited to the above-described embodiments. Improvements and modifications made by those skilled in the art based on the disclosure of the present invention, without departing from the scope of the present invention, should be within the scope of protection of the present invention.

Claims

1. A self-repairing ion gel electrolyte, characterized in that: The invention comprises a polymer network, an ionic liquid and movable zinc ions encapsulated in the polymer network. The polymer network is obtained by reacting an anionic monomer 2-acrylamido-2-methylpropanesulfonic acid sodium and a cationic monomer acryloyloxyethyltrimethylammonium chloride. The ionic liquid comprises 1-ethyl-3-methylimidazolium tetrafluoroborate, and the movable zinc ions are provided by zinc tetrafluoroborate hydrate.

2. A method for preparing the self-healing ion gel electrolyte according to claim 1, characterized in that: The following steps are involved: S1: dispersing and dissolving zinc tetrafluoroborate hydrate in 1-ethyl-3-methylimidazolium tetrafluoroborate, stirring and ultrasonicating to obtain a dispersion; S2: Add acryloyloxyethyltrimethylammonium chloride and sodium 2-acrylamido-2-methylpropanesulfonate to the dispersion in sequence and stir to dissolve, then add a crosslinker N,N′-methylenebisacrylamide and an initiator α-ketoglutaric acid in sequence, stir evenly, and perform a crosslinking reaction under ultraviolet light to obtain the self-healing ion gel electrolyte.

3. The method for preparing a self-repairing ion gel electrolyte according to claim 2, characterized in that: The mass ratio of the sodium 2-acrylamide-2-methylpropanesulfonate, acryloyloxyethyltrimethylammonium chloride and 1-ethyl-3-methylimidazolium tetrafluoroborate is 0.1165-0.4276:0.4432-1.1640:

1.

4. The method for preparing a self-repairing ion gel electrolyte according to claim 2, wherein: The mass ratio of the zinc tetrafluoroborate hydrate to 1-ethyl-3-methylimidazolium tetrafluoroborate is 0.2-0.8:1, and the mass ratio of the N,N′-methylenebisacrylamide, α-ketoglutaric acid to 1-ethyl-3-methylimidazolium tetrafluoroborate is 0.0001-0.0027:0.0125-0.0315:

1.

5. The method for preparing a self-repairing ion gel electrolyte according to claim 2, characterized in that: In step S1, the stirring time is 20-30 min, the stirring rate is 100-1000 rpm, the ultrasonic time is 5-30 min, and the ultrasonic frequency is 10-60 kHz.

6. The method for preparing a self-repairing ion gel electrolyte according to claim 2, characterized in that: In step S2, the stirring rate after adding acryloyloxyethyltrimethylammonium chloride and sodium 2-acrylamido-2-methylpropanesulfonate is 100-1000 rpm, and the stirring time is 20-60 min. The stirring rate after adding the crosslinking agent N,N′-methylenebisacrylamide and the initiator α-ketoglutaric acid is 100-1000 rpm, and the stirring time is 20-60 min.

7. The method for preparing a self-repairing ion gel electrolyte according to claim 2, characterized in that: In step S2, the cross-linking reaction under ultraviolet light specifically refers to: irradiating under ultraviolet light with a wavelength of 365 nm and reacting for 8 to 24 hours.

8. A zinc ion battery, characterized in that: It comprises the self-healing ion gel electrolyte according to claim 1, a positive thin film electrode and a negative thin film electrode arranged on both sides of the self-healing ion gel electrolyte, the positive thin film electrode and the negative thin film electrode are connected by copper wire, and the positive thin film electrode and the negative thin film electrode are connected to the copper wire through silver glue.

9. A zinc ion battery according to claim 8, characterized in that: The positive thin film electrode is a carbon nanotube / polyaniline thin film electrode, and the negative thin film electrode is a carbon nanotube / zinc thin film electrode.

10. Use of the zinc ion battery according to any one of claims 8 to 9 in a flexible energy storage device.

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