A polymer gel electrolyte and a method for preparing the same

Abstract

The application discloses a polymer gel electrolyte and a preparation method thereof, and relates to the technical field of polymer electrolytes.The application realizes a polymer network structure of "rigidity and flexibility combined" through a terpolymerization design of acrylic acid (AA), butyl acrylate (BA) and 2-ethylhexyl acrylate (2-EHA). The acrylic acid units provide abundant carboxyl groups, and form strong interactions such as hydrogen bonds with the electrode surface, so that the interfacial adhesion is significantly enhanced; the butyl acrylate and the 2-ethylhexyl acrylate serve as flexible units, long-chain alkyl ester groups are introduced, the chain segment movement ability is increased, and therefore the flexibility and the deformation recovery ability of the electrolyte are improved. The introduction of the flexible chain segment increases the free volume, optimizes the ion transmission channel, and improves the ionic conductivity.

Description

Technical Field

[0001] This invention relates to the field of polymer electrolyte technology, specifically to a polymer gel electrolyte with a molecular structure designed for multi-component copolymerization, its preparation method, and its application. Background Technology

[0002] Supercapacitors (SCs) are widely used in consumer electronics, new energy vehicles, and smart grids due to their high power density, rapid charge and discharge capabilities, and long cycle life. Flexible supercapacitors are key components of wearable electronic devices, and their core challenge lies in maintaining the stability of the electrode-electrolyte interface and ion transport efficiency under repeated mechanical deformations such as bending, folding, or stretching.

[0003] Currently, flexible supercapacitors often use liquid electrolytes or semi-solid gel electrolytes, but the interfacial adhesion between these electrolytes and solid electrodes is weak. Under dynamic mechanical deformation, interfacial delamination easily occurs, leading to increased contact resistance, obstructed ion transport paths, and consequently, a decline in electrochemical performance, such as decreased specific capacitance and increased internal resistance. Although existing polyacrylic acid (PAA) hydrogel electrolytes have certain ionic conductivity, their high brittleness and poor flexibility make it difficult to meet the mechanical durability requirements of flexible devices.

[0004] Therefore, there is an urgent need to develop a polymer gel electrolyte that combines excellent interfacial adhesion, high ionic conductivity, and good mechanical flexibility to improve the overall performance of flexible supercapacitors. Summary of the Invention

[0005] The technical problem to be solved by this invention is: how to provide an electrolyte for flexible electrochemical devices that can maintain the stability of electrochemical performance under dynamic mechanical deformation.

[0006] On one hand, the present invention provides a polymer gel electrolyte, comprising: a polymer network, wherein the polymer network is a terpolymer network formed by copolymerization of acrylic monomer, butyl acrylate monomer and 2-ethylhexyl acrylate monomer; and an ion-conducting medium impregnated in the polymer network.

[0007] Optionally, the ion-conducting medium is an acid solution, an alkaline solution, or a salt solution.

[0008] Optionally, the ion-conducting medium is a sulfuric acid solution, a phosphoric acid solution, a potassium hydroxide solution, or a lithium chloride solution.

[0009] Alternatively, the polymer network is a cross-linked network formed by cross-linking with a cross-linking agent.

[0010] Optionally, the crosslinking agent is N,N'-methylenebisacrylamide.

[0011] Optionally, based on the total molar number of monomers in the terpolymer network, the molar fraction of acrylic acid monomer is 20% to 50%, the molar fraction of butyl acrylate monomer is 10% to 60%, and the molar fraction of 2-ethylhexyl acrylate monomer is 10% to 60%.

[0012] On the other hand, the present invention provides a supercapacitor comprising a positive electrode, a negative electrode, and an electrolyte disposed between the positive and negative electrodes, wherein the electrolyte is the aforementioned polymer gel electrolyte.

[0013] On the other hand, the present invention provides a method for preparing the above-mentioned polymer gel electrolyte, comprising the following steps: S100, providing a mixed solution, the mixed solution comprising: acrylic monomer, butyl acrylate monomer, 2-ethylhexyl acrylate monomer, crosslinking agent, initiator and ion-conducting medium; S200, deoxygenating the mixed solution; S300, heating the mixed solution to the initiation temperature and maintaining it for a sufficient time under an inert atmosphere or vacuum environment to initiate the monomer polymerization reaction and form a polymer gel electrolyte.

[0014] Optionally, the ion-conducting medium is an aqueous solution of sulfuric acid with a concentration of 1M to 5M.

[0015] Optionally, the crosslinking agent is N,N'-methylenebisacrylamide, which has a mass of 0.2% to 3% of the total mass of acrylic acid monomer, butyl acrylate monomer and 2-ethylhexyl acrylate monomer.

[0016] Optionally, the initiator is ammonium persulfate, and its mass is 0.5% to 5% of the total mass of acrylic acid monomer, butyl acrylate monomer and 2-ethylhexyl acrylate monomer.

[0017] Optionally, the mixed solution also contains an emulsifier; the emulsifier is sodium dodecyl sulfate, which is 0.5% to 3% by mass of the total mass of acrylic monomer, butyl acrylate monomer and 2-ethylhexyl acrylate monomer.

[0018] Optionally, the initiation temperature is 60℃~95℃.

[0019] Optionally, keep it for a sufficient time of 6h to 24h.

[0020] The beneficial effects of implementing this invention are as follows: The polymer gel electrolyte provided by this invention achieves a "rigid-flexible" polymer network structure through a ternary copolymer design of acrylic acid (AA), butyl acrylate (BA), and 2-ethylhexyl acrylate (2-EHA). The acrylic acid unit provides abundant carboxyl groups, which, through strong interactions such as hydrogen bonds with the electrode surface, act as rigid units, significantly enhancing interfacial adhesion. The butyl acrylate and 2-ethylhexyl acrylate, as flexible units, introduce long-chain alkyl ester groups, effectively reducing the polymer's glass transition temperature and increasing chain segment mobility, thereby improving the electrolyte's flexibility and deformation recovery. Simultaneously, the introduction of flexible segments increases free volume, optimizes ion transport channels, and improves ionic conductivity. The rigid and flexible units work together to ensure the stability of the interface contact and the efficiency of ion transport under dynamic deformation. Ultimately, the supercapacitor containing this polymer gel electrolyte can maintain high specific capacitance and long cycle life under mechanical deformation such as bending and stretching. This significantly improves the long-term working stability and lifespan of flexible electronic devices (such as supercapacitors) using polymer gel electrolytes under dynamic mechanical deformation such as repeated bending and stretching. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the synthesis of PAA / P(BA-2-EHA) HPE material;

[0022] Figure 2 A schematic diagram showing the stress-strain comparison curves of PAA HPE and PAA / P(BA-2-EHA) HPE;

[0023] Figure 3 A bar chart showing the tensile strength versus tensile strain comparison of PAA HPE and PAA / P(BA-2-EHA) HPE.

[0024] Figure 4 Schematic diagram of the 180° peel test curves between PAA HPE and PAA / P(BA-2-EHA) HPE and the electrode;

[0025] Figure 5 A schematic diagram comparing the adhesion energy of PAA HPE and PAA / P(BA-2-EHA) HPE;

[0026] Figure 6 Schematic diagram of impedance testing for PAA HPE, PAA / PBA HPE and PAA / P(BA-2-EHA) HPE;

[0027] Figure 7 Schematic diagram of ionic conductivity testing for PAA HPE, PAA / PBA HPE and PAA / P(BA-2-EHA) HPE;

[0028] Figure 8 A comparative schematic diagram of charge-discharge curves for PAA HPE, PAA / PBA HPE, and PAA / P(BA-2-EHA) HPE-based SCs;

[0029] Figure 9 A comparative schematic diagram of the specific capacitance of PAA HPE, PAA / PBA HPE and PAA / P(BA-2-EHA) HPE-based SCs;

[0030] Figure 10 A schematic diagram comparing the specific capacitance of PAA HPE, PAA / PBA HPE and PAA / P(BA-2-EHA) HPE based SC at different current densities;

[0031] Figure 11 A schematic diagram of a sandwich-shaped flexible supercapacitor;

[0032] Figure 12 A schematic diagram simulating the bending of a sandwich-shaped flexible supercapacitor at different angles;

[0033] Figure 13 Schematic diagram of charge-discharge curves of PAA HPE, PAA / PBA HPE and PAA / P(BA-2-EHA) HPE based SC at 180°.

[0034] Figure 14 A schematic diagram comparing the specific capacitance and coulombic efficiency of PAA HPE, PAA / PBA HPE and PAA / P(BA-2-EHA) HPE-based SCs at 180°.

[0035] Figure 15 A schematic diagram comparing the specific capacitance of PAA HPE, PAA / PBA HPE, and PAA / P(BA-2-EHA) HPE-based SCs after 10,000 cycles at 180°. Detailed Implementation

[0036] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. The step numbers in the following embodiments are only for ease of explanation and do not limit the order of the steps. The execution order of each step in the embodiments can be adapted according to the understanding of those skilled in the art.

[0037] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to limit the embodiments of this application. The singular forms “a,” “the,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0038] In the following description, when referring to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims. In the description of this application, it should be understood that the terms "first," "second," "third," etc., are used only to distinguish similar objects and are not necessarily used to describe a specific order or sequence, nor should they be construed as indicating or implying relative importance. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0039] Furthermore, in the description of this application, unless otherwise stated, "multiple" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0040] Example 1

[0041] In this embodiment, as Figure 1 The polymer gel electrolyte shown includes: a polymer network, which is a terpolymer network formed by copolymerization of acrylic monomer, butyl acrylate monomer and 2-ethylhexyl acrylate monomer; and an ion-conducting medium impregnated in the polymer network.

[0042] In this embodiment, by introducing butyl acrylate (BA) monomer and 2-ethylhexyl acrylate (2-EHA) monomer as soft monomers, the toughness of the polymer network is enhanced, overcoming the brittle and hard defects of pure polyacrylic acid hydrogel, enabling it to withstand and recover repeated mechanical deformation, thereby making the constructed polymer gel electrolyte have high interfacial adhesion, excellent ionic conductivity and excellent mechanical flexibility.

[0043] In this embodiment, the ion-conducting medium is an acid solution, an alkaline solution, or a salt solution.

[0044] Optionally, the ion-conducting medium may be a sulfuric acid solution, a phosphoric acid solution, a potassium hydroxide solution, or a lithium chloride solution.

[0045] In this embodiment, the ion-conducting medium is specifically a sulfuric acid (H2SO4) solution in the state of a hydrogel polymer (HPE), which is used to form the electrolyte.

[0046] Specifically, the hydrogel polymer electrolyte in this embodiment is mainly made by mixing a polymer matrix (such as polyvinyl alcohol PVA) with a sulfuric acid solution.

[0047] In this embodiment, since butyl acrylate and 2-ethylhexyl acrylate monomers have certain hydrophobicity, a stable emulsion system can be formed in water by adding an emulsifier and stirring thoroughly during copolymerization, thereby making the construction of the terpolymer network more uniform.

[0048] In this embodiment, when the polymer gel electrolyte is used as the electrolyte of the battery, the carboxyl groups (-COOH) provided by the acrylic acid (AA) monomer in the polymer network form extensive hydrogen bonds and other physicochemical interactions with the electrode surface of the battery, thereby achieving a firm bond with the electrode and preventing interfacial peeling under bending, stretching and other deformations.

[0049] In this embodiment, the polymer network is placed in an acidic solution environment. The acrylic acid (AA) monomer can not only absorb a large amount of acid solution to form ion transport channels, but also its own ionizable protons (H+) + They can also participate in electrical conduction, thereby constructing a polymer network with high ion conductivity and ensuring the electrochemical performance of the device.

[0050] In this embodiment, the polymer network is a cross-linked network formed by cross-linking with a cross-linking agent.

[0051] In this embodiment, the crosslinking agent is N,N'-methylenebisacrylamide.

[0052] In this embodiment, based on the total molar number of monomers in the terpolymer network, the molar fraction of acrylic acid monomer is 20%~50%, the molar fraction of butyl acrylate monomer is 10%~60%, and the molar fraction of 2-ethylhexyl acrylate monomer is 10%~60%.

[0053] In this embodiment, the chemical formulas of AA, BA, and -2EHA are shown in the table below.

[0054]

[0055] In this embodiment, the acrylic (AA) bond-line formula is as follows:

[0056]

[0057] The bond-line formula corresponding to the molecular formula of butyl acrylate (BA), with its ester group linked to a n-butyl group, is as follows:

[0058]

[0059] 2-Ethylhexyl acrylate (2-EHA) has a 2-ethylhexyl side chain and a bond-line formula as follows:

[0060]

[0061] The three components form a random copolymer through free radical copolymerization. The main chain is a saturated carbon chain, and the side chains are carboxyl groups and different ester groups. The structural formula is as follows:

[0062]

[0063] Where m represents the degree of polymerization of the PAA chain segment;

[0064] p and q represent the degree of polymerization of BA and 2-EHA units in copolymer P(BA-2-EHA), respectively, and m, p, and q are all positive integers.

[0065] The structural characteristics of PAA / P(BA-2-EHA) HPE are as follows:

[0066] The main chain is composed of CH2-CH(X)- repeating units, where X is the side group of each monomer;

[0067] Side groups include:

[0068] -COOH, -COO (CH2)3CH3 and -COOCH2CH (C2H5)(CH2)3CH3.

[0069] From the structure of PAA / P(BA-2-EHA) HPE, we can see that:

[0070] The -COOH group provided by AA is the core functional group, providing polarity, hydrogen bonding and ion coordination ability, but the molecular chain is rigid.

[0071] BA has a straight-chain butyl-COO(CH2)3CH3, which provides a certain degree of chain flexibility and free volume of motion.

[0072] 2-EHA has a long, branched ethylhexyl-COOCH2CH(C2H5)(CH2)3CH3. This branched structure can greatly suppress the close packing of polymer chains, increase free volume, and thus provide excellent flexibility.

[0073] Example 2

[0074] This embodiment provides a verification embodiment based on Embodiment 1.

[0075] In this embodiment, Sample 1 (Control Group 1): 3M (mol / L) sulfuric acid (H2SO4) was used as solvent, acrylic acid (AA) was used as monomer, N,N'-methylenebisacrylamide (MBA) was used as crosslinking agent at a mass fraction of AA of 20% relative to the H2SO4 solvent and an amount of 1% of the total mass of AA, and ammonium persulfate (APS) was used at an amount of 1% of the total mass of monomer. The mixture was then thermally initiated and rapidly stirred to achieve a co-solubilized state in which microparticles coexist, thereby preparing PAA-H2SO4 gel polymer electrolyte (abbreviated as PAA HPE).

[0076] In this embodiment, Sample 2 (Control Group 2): Based on AA monomer, BA monomer was introduced as a soft monomer source, with BA = 40% and AA = 20% relative to the mass fraction of H2SO4 solvent; sodium dodecyl sulfate (SDS) of 0.5~3% of the total mass of AA and BA was used as an emulsifier, N,N'-methylenebisacrylamide of 1% of the total mass of AA and BA was used as a crosslinking agent, and APS of 1% of the total mass of AA and BA was used for thermal initiation of mixing. Rapid stirring can make the overall solution reach a co-solubilized state in which microparticles coexist, thus obtaining PAA / PBA-H2SO4 gel polymer electrolyte (abbreviated as PAA / PBA HPE).

[0077] In this embodiment, sample 3 (PAA / P(BA-2-EHA) HPE): 2-ethylhexyl acrylate monomer was introduced into PAA / PBA HPE and mixed according to the mass fractions of 2-EHA = 30%, AA = 20%, and BA = 40% relative to H2SO4 solvent. 0.5-3% of SDS (based on the total mass of AA, BA, and 2-EHA) was used as an emulsifier, 1% of N,N'-methylenebisacrylamide (based on the total mass of AA, BA, and 2-EHA) was used as a crosslinking agent, and 1% of ammonium persulfate (APS) (based on the total mass of AA, BA, and 2-EHA) was used for thermal initiation of the mixture. Rapid stirring allowed the overall solution to reach a co-solubilized state where microparticles coexisted, ultimately yielding PAA / P(BA-2-EHA) HPE.

[0078] In this embodiment, the concentration range of the H2SO4 solution is 1M to 5M.

[0079] In this embodiment, samples 1, 2, and 3 were all prepared using thermal initiation: First, a monomer mixture solution (AA, BA, 2-EHA monomers, along with crosslinking agent MBA and emulsifier SDS, added together to an H2SO4 solution with a concentration range of 0.2M~5M) was slowly poured into a three-necked flask. The three-necked flask was placed in a 60°C constant temperature water bath and equipped with a reflux condenser, a nitrogen inlet tube, and a stirrer. Stirring was started, and nitrogen (argon or helium can be used) was introduced under the liquid surface for 15~20 minutes to completely remove oxygen from the system and prevent oxygen from inhibiting free radical polymerization. An APS aqueous solution was added to the above solution and stirred rapidly (400-800 rpm) to ensure that the APS solution was quickly and uniformly dispersed in the solution. Then, it was added to a pre-prepared 1mm jacketed glass container using a syringe or pipette. The reaction was maintained under a nitrogen atmosphere and a 60°C water bath for 12 hours. The solution was observed to gradually thicken, eventually forming an elastic solid.

[0080] In this embodiment, the synthesis diagram of PAA / P(BA-2-EHA) HPE material obtained according to the above method is as follows: Figure 1 As shown.

[0081] In this embodiment, as Figure 2 and Figure 3 As shown, the tensile tests of samples 1 and 3 were conducted on a universal testing machine at a tensile rate of 100 mm / min. The samples had the same dimensions, with a length of 50 mm, a width of 4 mm, and a thickness of 2 mm.

[0082] from Figure 2 It can be seen that the tensile strength of PAA / P(BA-2-EHA) HPE is reduced, but the tensile strain is increased. By introducing flexible segments (flexible chains refer to PBA and P(2-EHA) polymer chains), the material is transformed from a hard and brittle state to a soft and tough state.

[0083] In this embodiment, samples 1 and 3 were subjected to a 180° peel test on a universal testing machine at a peel rate of 50 mm / min. The samples were rectangular in shape, 2 mm thick, and their width was determined by pre-test measurement. The ratio of the equilibrium peel force (F) to the sample width (d) was the adhesion energy (W², J / m²). 2 ).from Figure 4 and Figure 5 The test results show that the interfacial adhesion energy of PAA / P(BA-2-EHA) HPE is 1215 J / m. 2 The interfacial adhesion energy is higher than that of PAA HPE (746 J / m). 2This demonstrates that the introduction of BA and 2-EHA into sample 3 can significantly improve its interfacial adhesion with the electrode. Strong interfacial adhesion is crucial for the mechanical durability and electrochemical stability of flexible supercapacitors under long-term deformation.

[0084] In this embodiment, the AC impedance tests of samples 1, 2, and 3 were all performed on an electrochemical workstation at a frequency range of 0.1–100 kHz. All samples were identical in size, with a diameter of 14 mm and a thickness of 2 mm. The test results are as follows: Figure 6 and Figure 7 As shown, the ionic conductivity of PAA HPE is calculated to be 16 S / m, the ionic conductivity of the binary copolymer gel electrolyte PAA / PBAHPE is 20 S / m, and the ionic conductivity of the ternary copolymer gel electrolyte PAA / P(BA-2-EHA) HPE is 27 S / m.

[0085] In this embodiment, as Figure 6 and Figure 7 As shown, the experimental results indicate that the terpolymer network formed by the copolymerization of acrylic acid monomer, butyl acrylate monomer, and 2-ethylhexyl acrylate monomer significantly increases the ionic conductivity from 16 S / m of pure PAA to 27 S / m.

[0086] In this embodiment, the constant current charge-discharge tests of samples 1, 2, and 3 were all performed on the Blue Battery testing system with a voltage range of 0~0.7 V, and the sample size was 2×2×2 cm. 3 Or 1×4×2 cm 3 The constant current charge-discharge (GCD) curve and specific capacitance (C, unit: F / g) were obtained based on the test results. The test results are as follows: Figure 8 and Figure 9 As shown, the supercapacitor using sample 3 as the electrolyte has a specific capacitance of 279 mF / cm², which is a significant improvement over the 222 mF / cm² of sample 2 and the 176 mF / cm² of sample 1.

[0087] In this embodiment, as Figure 10 As shown in the figure, the specific capacitance of samples 1, 2, and 3 under different current densities is compared. It can be seen from the figure that the specific capacitance of sample 3 is significantly higher than that of samples 1 and 2. This proves that sample 3 not only ensures close contact at the electrode-electrolyte interface but also enhances energy storage capacity.

[0088] In this embodiment, as Figure 11 As shown in the figure, PANI / CC refers to the electrode plates. Figure 11 The bottom shows a schematic diagram of the assembly of the electrolyte and electrode sheets of a sandwich-shaped flexible supercapacitor, where the electrolyte based on sample 3 is located between two electrode sheets. Figure 11 The top image shows a schematic diagram of ion migration in a sandwich-shaped flexible supercapacitor.

[0089] In this embodiment, as Figure 12 As shown, the electrolyte based on PAA / P(BA-2-EHA) HPE is shown in schematic diagrams under bending conditions of 90°, 120° and 180°. The electrolyte and electrode sheet can still stick together without detachment or breakage, demonstrating excellent mechanical stability.

[0090] At the same time, such as Figures 13-15 As shown, under 180° bending conditions, the supercapacitor constructed using sample 3 as the electrolyte exhibits superior electrochemical performance. Its specific capacitance reaches 281 mF / cm², significantly outperforming the supercapacitors constructed using samples 2 and 1 as electrolytes. Under bending deformation, sample 3 maintains tight contact at the electrode-electrolyte interface, ensuring efficient ion transport. Simultaneously, its cross-linked network effectively disperses mechanical stress, preventing interface delamination, thus demonstrating excellent specific capacitance retention and stable coulombic efficiency.

[0091] The electrolyte based on PAA / P(BA-2-EHA) HPE exhibits a specific capacitance of 273 mF / cm² after 10,000 cycles of bending at 180°, which is significantly better than the 220 mF / cm² of the PAA / PBA HPE binary system and the 168 mF / cm² of the pure PAAHPE system.

[0092] In summary, in this embodiment, acrylic acid (AA) provides ion transport channels, while the introduction of butyl acrylate (BA) and 2-ethylhexyl acrylate (2-EHA) significantly enhances the polymer's flexibility and interfacial adhesion. Under flexural deformation, the electrolyte based on PAA / P(BA-2-EHA) HPE maintains tight contact at the electrode-electrolyte interface, ensuring efficient ion transport. Simultaneously, its crosslinked network effectively disperses mechanical stress and prevents interfacial delamination, thus exhibiting excellent capacity retention and stable coulombic efficiency.

[0093] Example 3

[0094] This embodiment provides a supercapacitor based on any of the above embodiments.

[0095] The supercapacitor in this embodiment includes a positive electrode, a negative electrode, and an electrolyte placed between the positive and negative electrodes. The electrolyte is the polymer gel electrolyte described above.

[0096] Example 4

[0097] This embodiment provides a method for preparing a polymer gel electrolyte based on any of the above embodiments.

[0098] In this embodiment, the preparation method of the polymer gel electrolyte includes the following steps:

[0099] S100. A mixed solution is provided, the mixed solution comprising: acrylic monomer, butyl acrylate monomer, 2-ethylhexyl acrylate monomer, crosslinking agent, initiator and ion-conducting medium;

[0100] S200. Deoxygenate the mixed solution. Specifically, as described in Example 2, nitrogen (argon or helium) is introduced into the solvent for 15-20 minutes to completely remove oxygen from the system.

[0101] S300. In an inert atmosphere or vacuum environment, heat the mixed solution to the initiation temperature and maintain it for a sufficient time to initiate the monomer polymerization reaction and form a polymer gel electrolyte.

[0102] Specifically, the ion-conducting medium is an aqueous solution of sulfuric acid with a concentration of 0.2M to 5M.

[0103] Specifically, the crosslinking agent is N,N'-methylenebisacrylamide, and its mass is 0.2% to 30% of the total mass of acrylic acid monomer, butyl acrylate monomer and 2-ethylhexyl acrylate monomer.

[0104] Specifically, the initiator is ammonium persulfate, and its mass is 0.5% to 5% of the total mass of acrylic acid monomer, butyl acrylate monomer and 2-ethylhexyl acrylate monomer.

[0105] Specifically, the mixed solution also contains an emulsifier;

[0106] The emulsifier is sodium dodecyl sulfate, which accounts for 0.5% to 3% of the total mass of acrylic acid monomer, butyl acrylate monomer and 2-ethylhexyl acrylate monomer.

[0107] Specifically, the initiation temperature is 40℃~95℃.

[0108] Specifically, keep it for a sufficient time of 6 to 24 hours.

[0109] The above is a detailed description of the preferred embodiments of the present invention. However, the present invention is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention. All such equivalent modifications or substitutions are included within the scope defined by the claims of this application.

Claims

1. A polymer gel electrolyte, characterized in that, include: The polymer network is a terpolymer network formed by copolymerization of acrylic monomer, butyl acrylate monomer and 2-ethylhexyl acrylate monomer; Among them, the acrylic unit provides carboxyl groups as rigid units to enhance interfacial adhesion, while the butyl acrylate and 2-ethylhexyl acrylate units introduce long-chain alkyl ester groups as flexible units to increase chain segment mobility and free volume, thereby optimizing ion transport channels. And an ion-conducting medium impregnated in the polymer network; The polymer network is a cross-linked network formed by cross-linking with a cross-linking agent; The crosslinking agent is N,N'-methylenebisacrylamide; Based on the total molar number of monomers in the terpolymer network, the molar fraction of the acrylic acid monomer is 20%~50%, the molar fraction of the butyl acrylate monomer is 10%~60%, and the molar fraction of the 2-ethylhexyl acrylate monomer is 10%~60%.

2. The polymer gel electrolyte according to claim 1, characterized in that, The ion-conducting medium is an acid solution, an alkaline solution, or a salt solution.

3. The polymer gel electrolyte according to claim 2, characterized in that, The ion-conducting medium is a sulfuric acid solution, a phosphoric acid solution, a potassium hydroxide solution, or a lithium chloride solution.

4. A supercapacitor, comprising a positive electrode, a negative electrode, and an electrolyte disposed between the positive and negative electrodes, characterized in that, The electrolyte is the polymer gel electrolyte according to any one of claims 1 to 3.

5. A method for preparing the polymer gel electrolyte as described in any one of claims 1 to 3, characterized in that, Includes the following steps: S100. A mixed solution is provided, the mixed solution comprising: acrylic monomer, butyl acrylate monomer, 2-ethylhexyl acrylate monomer, crosslinking agent, initiator and ion-conducting medium; S200, Deoxygenate the mixed solution; S300. Under an inert atmosphere or vacuum, the mixed solution is heated to the initiation temperature and held for a sufficient time to initiate the monomer polymerization reaction and form the polymer gel electrolyte.

6. The method according to claim 5, characterized in that, The ion-conducting medium is an aqueous solution of sulfuric acid with a concentration of 1M to 5M.

7. The method according to claim 5, characterized in that, The initiation temperature is 60℃~95℃; the holding time is 6h~24h.

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