In-situ polymerized aramid-based polymer electrolyte, and preparation method and application thereof

Abstract

The invention relates to the technical field of secondary battery polymer electrolyte, in particular to a preparation method and application of in-situ polymerized aramid-based polymer electrolyte. And the electrolyte is formed by in-situ cross-linking polymerization of aramid fiber and low-temperature molten salt electrolyte in the presence of an initiator. The ionic conductivity of the polymer electrolyte prepared by the method is higher than 1 * 10 <-4 > S cm <-1 >, the oxidation potential is higher than 4.50 V, and the thermal decomposition temperature of the electrolyte is higher than 400 DEG C. The capacity retention ratio of a lithium and sodium ion total battery assembled by the prepared polymer electrolyte is higher than 90% after 100 cycles.

Description

Technical Field

[0001] This invention relates to the field of polymer electrolyte technology for secondary batteries, specifically to an in-situ polymerized aramid-based polymer electrolyte, its preparation method, and its application. Background Technology

[0002] As the energy density of lithium-ion batteries continues to increase, their safety risks have become a key bottleneck restricting technological development. Against this backdrop, solid-state batteries, by fundamentally eliminating the flammability and leakage risks of traditional liquid electrolytes, exhibit significant safety advantages and are considered an important development direction for next-generation high-safety energy storage systems. However, in solid-state batteries, ion transport between the electrodes and electrolyte relies entirely on solid-solid contact. This interfacial characteristic leads to high contact impedance and poor stability, making it highly susceptible to interfacial failure and severely limiting its electrochemical performance. To overcome this challenge, in-situ polymerization technology has emerged. This technology directly polymerizes solid electrolytes inside the battery, constructing an integrated "fusion interface" that effectively enhances interfacial contact, reduces interfacial impedance, and thus significantly improves ion transport kinetics. However, polymer electrolytes prepared by in-situ polymerization currently face the new challenge of insufficient thermal stability; their decomposition and failure at high temperatures may lead to new safety hazards. Therefore, developing novel in-situ polymerized electrolyte systems with both excellent interfacial characteristics and high thermal stability has become a key scientific problem that urgently needs to be solved to promote the practical application of solid-state batteries.

[0003] Aramid fibers are engineered polymers renowned for their excellent thermal stability and mechanical strength, and their introduction is considered an effective way to improve the thermal performance of electrolytes. However, the strong hydrogen bond network between aramid molecular chains results in extremely poor solubility in conventional organic solvents, making it impossible to disperse in in-situ polymerization precursor solutions. This has become a major technical bottleneck for its application in the construction of in-situ polymer electrolytes. Overcoming the solubility limitations of aramid fibers and developing their application in high-safety in-situ polymer electrolytes is of great significance for promoting the development of next-generation solid-state batteries.

[0004] Chinese Patent 119253192A discloses a composite coated separator for lithium-ion batteries and its preparation method. The method involves coating an aramid polymer onto a polyolefin or similar base film, followed by coagulation bath and drying to obtain an aramid-coated separator intermediate. A TiO2 treatment solution is then coated onto the surface of this intermediate, followed by drying to obtain the composite coated separator. In this patent, the aramid polymer coating acts as a heat-resistant layer to improve the high-temperature thermal shrinkage performance of the composite separator. However, aramid itself lacks ion conductivity; therefore, this coating negatively impacts the ionic conductivity of the separator after washing, thus deteriorating the battery's charge-discharge performance at high current densities.

[0005] Chinese Patent 107170942A discloses a high-temperature resistant aramid lithium-ion battery composite separator and its preparation method. This invention involves coating a base membrane with a layer composed of aramid and inorganic ceramic particles on one or both sides to obtain the composite separator. The aramid coating has a micron-sized porous structure. Although the aramid skeleton has good thermal stability, its porous structure is still prone to deformation at high temperatures, causing severe thermal shrinkage of the separator.

[0006] In existing patents, aramid polymers are only used as heat-resistant coatings to improve the thermal shrinkage and flame-retardant properties of diaphragms. However, due to the poor solubility and processability of aramid fibers, the diaphragm coating process requires high precision. Furthermore, the polymer chains lack ion-transporting groups, which hinder the formation of Li+. + This increases the transport capacity and internal resistance of the battery. In-situ polymerization of heat-resistant aramid molecular chains into polymer electrolytes holds promise for obtaining polymer electrolytes with both excellent thermal stability and ion transport properties. However, no such research has been reported. Summary of the Invention

[0007] The purpose of this invention is to provide an in-situ polymerized aramid-based electrolyte, its preparation method, and its application.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows: An in-situ polymerized aramid-based polymer electrolyte, wherein the electrolyte is formed by aramid, low-temperature molten salt electrolyte and initiator to form an aramid-based polymer electrolyte; The aramid fiber is one or more polymers with the following structures, where n is selected from an integer from 10 to 1000; the aramid fiber accounts for 1-45% of the electrolyte by mass; .

[0009] The low-temperature molten salt electrolyte is prepared by mixing organic compounds and metal salts in a certain proportion, wherein the molar ratio of organic compounds to metal salts is 1-9:1; wherein the organic compounds are one or more of acrylamide, cyclobutene sulfone, propylene-1,3-sulfonyl lactone or N-methylacrylamide.

[0010] The metal salt is a lithium or sodium salt; wherein the metal salt is lithium hexafluorophosphate, sodium hexafluorophosphate, lithium tetrafluoroborate, sodium tetrafluoroborate, lithium bis(trifluoromethanesulfonyl)imide, bis(trifluoromethanesulfonyl)imide, lithium difluorooxalate borate, sodium difluorooxalate borate, lithium bis(trifluoromethanesulfonyl)imide, or sodium bis(trifluoromethanesulfonyl)imide.

[0011] A method for preparing the in-situ polymerized aramid-based polymer electrolyte, as described above. S1. Mix salt and low-temperature molten salt at room temperature with stirring for 1-12 hours to form a low-temperature molten salt electrolyte; S2. Add aramid fibers to step S1 above and stir at 20-75°C for 0.5-60 hours to form a homogeneous solution; S3. Add an initiator to the solution obtained in S2 and stir at 20-45℃ for 0.1-72 hours to prepare an aramid-based polymer electrolyte precursor solution.

[0012] The above-obtained aramid-based polymer electrolyte precursor solution is placed on a substrate and in-situ polymerized at 30-100°C for 0.5-72 hours to form an aramid-based polymer electrolyte.

[0013] An application of the in-situ polymerized aramid-based polymer electrolyte, specifically its application in the fabrication of energy storage devices.

[0014] The energy storage device is a lithium secondary battery, a sodium secondary battery, or a capacitor.

[0015] The principle of this invention is as follows: This invention utilizes the in-situ copolymerization of aramid molecules with double bonds in a low-temperature molten salt electrolyte under thermally initiated conditions to form a polymer electrolyte. The efficient ion transport characteristics of the low-temperature molten salt electrolyte endow the electrolyte with rapid ion transport kinetics. Simultaneously, the high boiling point and non-flammability of the low-temperature molten salt, combined with the outstanding thermal stability of aramid, mitigate battery thermal runaway. The solid-state battery described in this patent is assembled and prepared using an in-situ electrolyte polymerization process. This process ensures thorough electrolyte wetting of the electrodes and simultaneously achieves electrode-electrolyte interface fusion, improving interfacial ion transport kinetics and enhancing battery cycle stability and rate performance. Therefore, the aramid-based in-situ polymer electrolyte can synergistically improve battery electrochemical performance and thermal safety.

[0016] Compared with the prior art, the present invention has the following advantages and beneficial effects: (1) The aramid side chains of this invention contain polymeric functional groups, such as double bonds and epoxy groups, which directly undergo cross-linking reactions with low-temperature molten salt electrolytes to achieve the fusion of heat-resistant framework and ion-conducting chain segments, and to construct efficient ion transport channels. Therefore, this electrolyte has good intrinsic ionic conductivity.

[0017] (2) In the preparation steps of the aramid-based polymer electrolyte by in-situ polymerization of the present invention, a homogeneous solution is first formed by mixing modified aramid with electrolyte with excellent solubility. This promotes the uniform distribution of aramid molecular chains in polymer electrolyte and is beneficial to improving the mechanical properties of electrolyte.

[0018] (3) Due to the outstanding thermal stability of aramid, the in-situ polymerized aramid-based polymer electrolyte provided by the present invention has superior thermal stability compared to other reported in-situ polymer electrolytes.

[0019] (4) The solid-state battery assembly in this invention is achieved by injecting a liquid precursor formed by aramid and electrolyte into the battery and then polymerizing it in situ. This promotes the fusion of the electrode and electrolyte interfaces. Therefore, the assembled battery has good cycle stability, with a capacity retention rate of over 90% after 100 cycles. In addition, the cross-linked aramid improves the thermal stability and mechanical strength of the electrolyte, which prevents the battery from short-circuiting, catching fire, or exploding when operating at 130°C. Thus, this composite electrolyte can comprehensively improve the electrochemical performance and thermal safety of the battery. Detailed Implementation

[0020] The present invention will be further described in detail below with reference to the embodiments, but the implementation of the present invention is not limited thereto.

[0021] This invention utilizes aramid fibers with flexible side chains and double bonds dissolved in a low-temperature molten salt electrolyte. Under the presence of an initiator, the double bonds of the aramid side chains are thermally initiated to polymerize in situ with the double bonds of the electrolyte, forming a homogeneous aramid-based polymer electrolyte. The polymer electrolyte obtained by this invention has an ionic conductivity higher than 1×10⁻⁶. -4 S cm -1 The oxidation potential is higher than 4.50 V, and the electrolyte thermal decomposition temperature is higher than 400℃. The lithium-sodium ion full cells assembled with the prepared polymer electrolyte retain more than 90% of their capacity after 100 cycles.

[0022] Example 1 (1) Weigh 151.9 g of lithium hexafluorophosphate and add it to 255.3 g of N-methylacrylamide. The amount of lithium salt is 25%. Stir at room temperature for 1 hour to form a low-temperature molten salt electrolyte.

[0023] (2) Weigh 30 grams of modified aramid fiber into the glove box. (n=50) Dissolve in the electrolyte obtained in step (1) and stir at 35°C for 10 hours to form a homogeneous solution.

[0024] (3) Add 0.2% by mass of azobisisobutyronitrile to the solution obtained in step (2) and stir at 25 °C for 3 hours to prepare an in-situ polymerization precursor solution.

[0025] (4) In the glove box, the electrolyte precursor obtained in step (3) is drop-coated onto the ternary positive electrode (NCM) and the graphite negative electrode respectively. The battery case, spring sheet, gasket, negative electrode, separator and positive electrode sheet are stacked neatly in sequence, and then the battery is packaged and assembled.

[0026] (5) Take the assembled battery out of the glove box and let it stand at 60°C for 5 hours for in-situ polymerization. Then, perform charge and discharge tests, hot box tests, etc. on the battery.

[0027] Physical and chemical property tests: (1) The ionic conductivity of the above aramid electrolyte was measured at room temperature using the AC impedance spectroscopy method (GB / T 202456(20245.3-2013)) and was 8.5 × 10⁻⁶. -4 S cm -1 .

[0028] (2) The differential thermogravimetric method was used to test the thermal decomposition temperature of the electrolyte at 474℃.

[0029] (3) The voltage stability window of the electrolyte was tested using the linear sweep voltammetry method, which is 4.71 V.

[0030] Battery performance test: (1) Charge-discharge performance test. At 30 ℃, the discharge capacity at current densities of 0.2, 1, and 5 C rates was 162 mAh g. -1 155 mAh g -1 and 143 mAh g -1 The battery retains 95.3% of its capacity after 100 1C cycles.

[0031] (2) Hot box test. The assembled battery was placed in a hot box at 150°C and heated for 30 minutes. The battery did not short circuit, catch fire or explode.

[0032] (3) External short circuit test. Assemble a 5Ah soft pack battery and short-circuit the positive and negative terminals of the battery directly with a wire. The battery does not experience thermal runaway.

[0033] (4) Needle penetration test. Using a 3 mm steel needle, the needle is vertically inserted into the center area of ​​a fully charged 10Ah battery at a speed of 25 mm / min. The battery does not catch fire or explode.

[0034] Comparative Example 1 The difference between this comparative example and Example 1 is that sulfolane is used instead of N-methylacrylamide.

[0035] (1) Weigh 151.9 g of lithium hexafluorophosphate and add it to 360.53 g of sulfolane. The amount of lithium salt is 25%. Stir at room temperature for 1 hour to form a low-temperature molten salt electrolyte.

[0036] (2) Weigh 30 grams of modified aramid fiber into the glove box. (n=50) Dissolve in the electrolyte obtained in step (1) and stir at 35°C for 10 hours to form a homogeneous solution.

[0037] (3) Add 0.2% by mass of azobisisobutyronitrile to the solution obtained in step (2) and stir at 25 °C for 3 hours to prepare an in-situ polymerization precursor solution.

[0038] (4) In the glove box, drop the precursor solution obtained in step (3) onto the ternary cathode (NCM) and graphite anode respectively, and then stack the battery case, spring sheet, gasket, anode, separator and cathode sheet in sequence, and then package and assemble the battery.

[0039] (5) Take the assembled battery out of the glove box and let it stand at 60°C for 5 hours for in-situ polymerization. Then, perform charge and discharge tests, hot box tests, etc. on the battery.

[0040] Physical and chemical property tests: (1) The ionic conductivity of the above polyimide composite electrolyte was measured to be 1.3 × 10⁻⁶ by AC impedance spectroscopy at room temperature (GB / T 202456(20245.3-2013)). -3 S cm -1 .

[0041] (2) The differential thermogravimetric method was used to test the thermal decomposition temperature of the electrolyte at 204℃.

[0042] (3) The voltage stability window of the electrolyte was tested using the linear sweep voltammetry method, which is 4.45V.

[0043] Battery performance test: (1) Charge-discharge performance test: At 30℃, the discharge capacity at current densities of 0.2, 1, and 5 C rates was 142 mAh g. -1 131 mAh g -1 and 14 mAh g -1 The battery retains 50.2% of its capacity after 100 1C cycles.

[0044] (2) Hot box test. The assembled battery was placed in a hot box at 150°C and heated for 30 minutes. The battery short-circuited and smoked.

[0045] (3) External short circuit test. Assemble a 5Ah soft-pack battery and short-circuit the positive and negative terminals of the battery directly with a wire. The battery will thermally run away and burn.

[0046] (4) Needle penetration test. Using a 3 mm steel needle, the battery was vertically penetrated into the center of a fully charged 10Ah battery at a speed of 25 mm / min, causing the battery to explode.

[0047] The experimental results of Example 1 and Comparative Example 1 show that organic compounds that form low-temperature molten salts with metal salts cannot achieve in-situ solidification without double bonds, and therefore the assembled batteries experience short circuits and thermal runaway when heated to 150°C.

[0048] Comparative Example 2 The difference between this comparative example and Example 1 is that polymethyl methacrylate is used instead of aramid.

[0049] (1) Weigh 151.9 g of lithium hexafluorophosphate and add it to 255.3 g of N-methylacrylamide. The amount of lithium salt is 25%. Stir at room temperature for 1 hour to form a low-temperature molten salt electrolyte.

[0050] (2) Weigh 30 grams of polymethyl methacrylate in the glove box and dissolve it in the electrolyte obtained in step (1). Stir at 35°C for 10 hours to form a homogeneous solution.

[0051] (3) Add 0.2% by mass of azobisisobutyronitrile to the solution obtained in step (2) and stir at 25 °C for 3 hours to prepare an in-situ polymerization precursor solution.

[0052] (4) In the glove box, drop the precursor solution obtained in step (3) onto the ternary cathode (NCM) and graphite anode respectively, and then stack the battery case, spring sheet, gasket, anode, separator and cathode sheet in sequence, and then package and assemble the battery.

[0053] (5) Take the assembled battery out of the glove box and let it stand at 60°C for 5 hours for in-situ polymerization. Then, perform charge-discharge tests and hot box tests on the battery.

[0054] Physical and chemical property tests: (1) The ionic conductivity of the above electrolyte was measured by AC impedance spectroscopy at room temperature (GB / T 202456(20245.3-2013)) to be 8.7 × 10⁻⁶. -4 S cm -1 .

[0055] (2) The polymethyl methacrylate in the above embodiment was subjected to high temperature treatment in the presence of an initiator and crosslinked with the electrolyte. The thermal decomposition temperature of the electrolyte was 357°C.

[0056] (3) The voltage stability window of the electrolyte obtained above was 4.20 V when tested by linear scanning voltammetry, which is significantly lower than that of the in-situ polymerized aramid-based polymer electrolyte.

[0057] Battery performance test: (1) Charge-discharge performance test: At 30℃, the discharge capacity at current densities of 0.2, 1, and 5 C rates was 160 mAh g. -1 152 mAh g -1 and 130 mAh g -1 The battery retains 96.6% of its capacity after 100 1C cycles.

[0058] (2) Hot box test. The assembled battery was placed in a hot box at 150 °C and heated for 30 min. The battery short-circuited and then caught fire.

[0059] (3) External short circuit test. Assemble a 5Ah soft-pack battery and short-circuit the positive and negative terminals of the battery directly with a wire. The battery will thermally run away and catch fire.

[0060] (4) Needle penetration test. Using a 3 mm steel needle, the battery was vertically penetrated into the center of a fully charged 10Ah battery at a speed of 25 mm / min, causing the battery to explode.

[0061] The experimental results of Example 1 and Comparative Example 2 show that, due to the poor thermal stability of polymethyl methacrylate (PMMA), the voltage and thermal stability of the polymer electrolyte obtained by the final polymerization are inferior to those of the aramid-based polymer electrolyte. The battery assembled from PMMA experienced a short circuit and thermal runaway when heated to 150°C.

[0062] Example 2 Compared with Example 1, this embodiment changes the mass of aramid added to the solution in step (2).

[0063] (1) Weigh 151.9 g of lithium hexafluorophosphate and add it to 255.3 g of N-methylacrylamide. The amount of lithium salt is 25%. Stir at room temperature for 1 hour to form a low-temperature molten salt electrolyte.

[0064] (2) Weigh 50 grams of modified aramid fiber into the glove box. (n=50) Dissolve in the electrolyte obtained in step (1) and stir at 35°C for 10 hours to form a homogeneous solution.

[0065] (3) Add 0.2% by mass of azobisisobutyronitrile to the solution obtained in step (2) and stir at 25 °C for 3 hours to prepare an in-situ polymerization precursor solution.

[0066] (4) In the glove box, drop the precursor solution obtained in step (3) onto the ternary cathode (NCM) and graphite anode respectively, and then stack the battery case, spring sheet, gasket, anode, separator and cathode sheet in sequence, and then package and assemble the battery.

[0067] (5) Take the assembled battery out of the glove box and let it stand at 60°C for 5 hours for in-situ polymerization. Then, perform charge and discharge tests, hot box tests, etc. on the battery.

[0068] Physical and chemical property tests: (1) The ionic conductivity of the above-mentioned polyimide-based overheating self-protecting polymer electrolyte was measured by AC impedance spectroscopy at room temperature (GB / T 202456(20245.3-2013)) to be 6.9 × 10⁻⁶.-4 S cm -1 .

[0069] (2) The differential thermogravimetric method was used to test the thermal decomposition temperature of the electrolyte at 479℃.

[0070] (3) The voltage stability window of the electrolyte obtained above was tested using the linear sweep voltammetry method, which is 4.58 V.

[0071] Battery performance test: (1) Charge-discharge performance test: At 30℃, the discharge capacity at current densities of 0.2, 1, and 5 C rates was 151 mAh g. -1 140 mAh g -1 and 134 mAh g -1 The battery retains 94.2% of its capacity after 100 1C cycles.

[0072] (2) Hot box test. The assembled battery was placed in a hot box at 150°C and heated for 30 minutes. The battery did not short circuit, catch fire or explode.

[0073] (3) External short circuit test. Assemble a 5Ah soft pack battery and short-circuit the positive and negative terminals of the battery directly with a wire. The battery does not experience thermal runaway.

[0074] (4) Needle penetration test. Using a 3 mm steel needle, the needle is vertically inserted into the center area of ​​a fully charged 10Ah battery at a speed of 25 mm / min. The battery does not catch fire or explode.

[0075] Example 3 Compared with Example 1, this embodiment changes the proportion of lithium salt in the electrolyte in step (1).

[0076] (1) Weigh 151.9 g of lithium hexafluorophosphate and add it to 212.75 g of N-methylacrylamide. The amount of lithium salt is 28.6%. Stir at room temperature for 1 hour to form a low-temperature molten salt electrolyte.

[0077] (2) Weigh 30 grams of modified aramid fiber into the glove box. (n=50) Dissolve in the electrolyte obtained in step (1) and stir at 35°C for 10 hours to form a homogeneous solution.

[0078] (3) Add 0.2% by mass of azobisisobutyronitrile to the solution obtained in step (2) and stir at 25 °C for 3 hours to prepare an in-situ polymerization precursor solution.

[0079] (4) In the glove box, drop the precursor solution obtained in step (3) onto the ternary cathode (NCM) and graphite anode respectively, and then stack the battery case, spring sheet, gasket, anode, separator and cathode sheet in sequence, and then package and assemble the battery.

[0080] (5) Take the assembled battery out of the glove box and let it stand at 60°C for 5 hours for in-situ polymerization. Then, perform charge and discharge tests, hot box tests, etc. on the battery.

[0081] Physical and chemical property tests: (1) The ionic conductivity of the above-mentioned polyimide-based overheating self-protecting polymer electrolyte was measured by AC impedance spectroscopy at room temperature (GB / T 202456(20245.3-2013)) to be 9.1 × 10⁻⁶. -4 S cm -1 .

[0082] (2) The differential thermogravimetric method was used to test the thermal decomposition temperature of the electrolyte at 472℃.

[0083] (3) The voltage stability window of the electrolyte obtained above was tested using the linear sweep voltammetry method, which is 4.56 V.

[0084] Battery performance test: (1) Charge-discharge performance test: At 30 ℃, the discharge capacity at current densities of 0.2, 1, and 5 C rates was 153 mAh g. -1 142 mAh g -1 and 136 mAh g -1 The battery retains 94.7% of its capacity after 100 1C cycles.

[0085] (2) Hot box test. The assembled battery was placed in a hot box at 150°C and heated for 30 minutes. The battery did not short circuit, catch fire or explode.

[0086] (3) External short circuit test. Assemble a 5Ah soft pack battery and short-circuit the positive and negative terminals of the battery directly with a wire. The battery does not experience thermal runaway.

[0087] (4) Needle penetration test. Using a 3 mm steel needle, the needle is vertically inserted into the center area of ​​a fully charged 10Ah battery at a speed of 25 mm / min. The battery does not catch fire or explode.

[0088] Example 4 Compared with Example 1, this embodiment changes the aramid structure in step 2.

[0089] (1) Weigh 151.9 g of lithium hexafluorophosphate and add it to 255.3 g of N-methylacrylamide. The amount of lithium salt is 25%. Stir at room temperature for 1 hour to form a low-temperature molten salt electrolyte.

[0090] (2) Weigh 30 grams of modified aramid fiber into the glove box. (n=50) Dissolve in the electrolyte obtained in step (1) and stir at 35°C for 10 hours to form a homogeneous solution.

[0091] (3) Add 0.2% by mass of initiator to the solution obtained in step (2) and stir at 25 °C for 3 hours to prepare an in-situ polymerization precursor solution.

[0092] (4) In the glove box, drop the precursor solution obtained in step (3) onto the ternary cathode (NCM) and graphite anode respectively, and then stack the battery case, spring sheet, gasket, anode, separator and cathode sheet in sequence, and then package and assemble the battery.

[0093] (5) Take the assembled battery out of the glove box and let it stand at 60°C for 5 hours for in-situ polymerization. Then, perform charge and discharge tests, hot box tests, etc. on the battery.

[0094] Physical and chemical property tests: (1) The ionic conductivity of the above-mentioned polyimide-based overheating self-protecting polymer electrolyte was measured by AC impedance spectroscopy at room temperature (GB / T 202456(20245.3-2013)) to be 6.7 × 10⁻⁶. -4 S cm -1 .

[0095] (2) The differential thermogravimetric method was used to test the thermal decomposition temperature of the electrolyte at 477℃.

[0096] (3) The voltage stability window of the electrolyte obtained above was tested using the linear sweep voltammetry method, which is 4.56 V.

[0097] Battery performance test: (1) Charge-discharge performance test: At 30 ℃, the discharge capacity at current densities of 0.2, 1, and 5 C rates was 164 mAh g. -1 155 mAh g -1 and 148 mAh g -1 The battery retains 95.7% of its capacity after 100 1C cycles.

[0098] (2) Hot box test. The assembled battery was placed in a hot box at 150°C and heated for 30 minutes. The battery did not short circuit, catch fire or explode.

[0099] (3) External short circuit test. Assemble a 5Ah soft pack battery and short-circuit the positive and negative terminals of the battery directly with a wire. The battery does not experience thermal runaway.

[0100] (4) Needle penetration test. Using a 3 mm steel needle, the needle is vertically inserted into the center area of ​​a fully charged 10Ah battery at a speed of 25 mm / min. The battery does not catch fire or explode.

[0101] Example 5 Compared with Example 1, this embodiment changes the amount of initiator added in step (2).

[0102] (1) Weigh 151.9 g of lithium hexafluorophosphate and add it to 255.3 g of N-methylacrylamide. The amount of lithium salt is 25%. Stir at room temperature for 1 hour to form a low-temperature molten salt electrolyte.

[0103] (2) Weigh 30 grams of modified aramid fiber into the glove box. (n=50) Dissolve in the electrolyte obtained in step (1) and stir at 35°C for 10 hours to form a homogeneous solution.

[0104] (3) Add 0.3% by mass of azobisisobutyronitrile to the solution obtained in step (2) and stir at 25 °C for 3 hours to prepare an in-situ polymerization precursor solution.

[0105] (4) In the glove box, drop the precursor solution obtained in step (3) onto the ternary cathode (NCM) and graphite anode respectively, and then stack the battery case, spring sheet, gasket, anode, separator and cathode sheet in sequence, and then package and assemble the battery.

[0106] (5) Take the assembled battery out of the glove box and let it stand at 60°C for 5 hours for in-situ polymerization. Then, perform charge and discharge tests, hot box tests, etc. on the battery.

[0107] Physical and chemical property tests: (1) The ionic conductivity of the above-mentioned polyimide-based overheating self-protecting polymer electrolyte was measured by AC impedance spectroscopy at room temperature (GB / T 202456(20245.3-2013)) to be 7.0 × 10⁻⁶. -4 S cm -1 .

[0108] (2) The differential thermogravimetric method was used to test the thermal decomposition temperature of the electrolyte at 492℃.

[0109] (3) The voltage stability window of the electrolyte obtained above was tested using the linear sweep voltammetry method, which is 4.55 V.

[0110] Battery performance test: (1) Charge-discharge performance test: At 30℃, the discharge capacity at current densities of 0.2, 1, and 5 C rates was 154 mAh g. -1 148 mAh g -1 and 141mAh g -1 The battery retains 95.7% of its capacity after 100 1C cycles.

[0111] (2) Hot box test. The assembled battery was placed in a hot box at 150°C and heated for 30 minutes. The battery did not short circuit, catch fire or explode.

[0112] (3) External short circuit test. Assemble a 5Ah soft pack battery and short-circuit the positive and negative terminals of the battery directly with a wire. The battery does not experience thermal runaway.

[0113] (4) Needle penetration test. Using a 3 mm steel needle, the needle is vertically inserted into the center area of ​​a fully charged 10Ah battery at a speed of 25 mm / min. The battery does not catch fire or explode.

[0114] Example 6 Compared with Example 1, this embodiment changes the in-situ solidification reaction temperature in step (5).

[0115] (1) Weigh 151.9 g of lithium hexafluorophosphate and add it to 255.3 g of N-methylacrylamide. The amount of lithium salt is 25%. Stir at room temperature for 1 hour to form a low-temperature molten salt electrolyte.

[0116] (2) Weigh 30 grams of modified aramid fiber into the glove box. (n=50) Dissolve in the electrolyte obtained in step (1) and stir at 35°C for 10 hours to form a homogeneous solution.

[0117] (3) Add 0.2% by mass of azobisisobutyronitrile to the solution obtained in step (2) and stir at 25 °C for 3 hours to prepare an in-situ polymerization precursor solution.

[0118] (4) In the glove box, drop the precursor solution obtained in step (3) onto the ternary cathode (NCM) and graphite anode respectively, and then stack the battery case, spring sheet, gasket, anode, separator and cathode sheet in sequence, and then package and assemble the battery.

[0119] (5) Take the assembled battery out of the glove box and let it stand at 50°C for 5 hours for in-situ polymerization. Then, perform charge and discharge tests, hot box tests, etc. on the battery.

[0120] Physical and chemical property tests: (1) The ionic conductivity of the above-mentioned polyimide-based overheating self-protecting polymer electrolyte was measured by AC impedance spectroscopy at room temperature (GB / T 202456(20245.3-2013)) to be 3.1 × 10⁻⁶. -4 S cm -1 .

[0121] (2) The differential thermogravimetric method was used to test the thermal decomposition temperature of the electrolyte at 493℃.

[0122] (3) The voltage stability window of the electrolyte obtained above was tested using the linear sweep voltammetry method, which is 4.67 V.

[0123] Battery performance test: (1) Charge-discharge performance test: At 30℃, the discharge capacity at current densities of 0.2, 1, and 5 C rates was 132 mAh g. -1 121 mAh g -1 and 109 mAh g -1 The battery retains 90.1% of its capacity after 100 1C cycles.

[0124] (2) Hot box test. The assembled battery was placed in a hot box at 150°C and heated for 30 minutes. The battery did not short circuit, catch fire or explode.

[0125] (3) External short circuit test. Assemble a 5Ah soft pack battery and short-circuit the positive and negative terminals of the battery directly with a wire. The battery does not experience thermal runaway.

[0126] (4) Needle penetration test. Using a 3 mm steel needle, the needle is vertically inserted into the center area of ​​a fully charged 10Ah battery at a speed of 25 mm / min. The battery does not catch fire or explode.

[0127] Example 7 Compared to Example 1, cyclobutene sulfone was used instead of N-methylacrylamide.

[0128] (1) Weigh 151.9 g of lithium hexafluorophosphate and add it to 354.5 g of cyclobutene sulfone. The amount of lithium salt is 25%. Stir at room temperature for 1 hour to form a low-temperature molten salt electrolyte.

[0129] (2) Weigh 30 grams of modified aramid fiber into the glove box. (n=50) Dissolve in the electrolyte obtained in step (1) and stir at 35°C for 10 hours to form a homogeneous solution.

[0130] (3) Add 0.2% by mass of azobisisobutyronitrile to the solution obtained in step (2) and stir at 25 °C for 3 hours to prepare an in-situ polymerization precursor solution.

[0131] (4) In the glove box, drop the precursor solution obtained in step (3) onto the ternary cathode (NCM) and graphite anode respectively, and then stack the battery case, spring sheet, gasket, anode, separator and cathode sheet in sequence, and then package and assemble the battery.

[0132] (5) Take the assembled battery out of the glove box and let it stand at 50°C for 5 hours for in-situ polymerization. Then, perform charge and discharge tests, hot box tests, etc. on the battery.

[0133] Physical and chemical property tests: (1) The ionic conductivity of the above-mentioned polyimide-based overheating self-protecting polymer electrolyte was measured by AC impedance spectroscopy at room temperature (GB / T 202456(20245.3-2013)) to be 4.6 × 10⁻⁶. -4 S cm -1 .

[0134] (2) The differential thermogravimetric method was used to test the thermal decomposition temperature of the electrolyte at 452℃.

[0135] (3) The voltage stability window of the electrolyte obtained above was tested using the linear sweep voltammetry method, which is 4.67 V.

[0136] Battery performance test: (1) Charge-discharge test: At 30℃, the discharge capacity at current densities of 0.2, 1, and 5 C rates was 150 mAh g. -1 137 mAh g -1 and 124 mAh g -1 The battery retains 91.9% of its capacity after 100 1C cycles.

[0137] (2) Hot box test. The assembled battery was placed in a hot box at 150°C and heated for 30 minutes. The battery did not short circuit, catch fire or explode.

[0138] (3) External short circuit test. Assemble a 5Ah soft pack battery and short-circuit the positive and negative terminals of the battery directly with a wire. The battery does not experience thermal runaway.

[0139] (4) Needle penetration test. Using a 3 mm steel needle, the needle is vertically inserted into the center area of ​​a fully charged 10Ah battery at a speed of 25 mm / min. The battery does not catch fire or explode.

[0140] Example 8 Compared to Example 7, azobiscyclohexylformonitrile was used instead of azobisisobutyronitrile as the initiator.

[0141] (1) Weigh 151.9 g of lithium hexafluorophosphate and add it to 354.5 g of cyclobutene sulfone. The amount of lithium salt is 25%. Stir at room temperature for 1 hour to form a low-temperature molten salt electrolyte.

[0142] (2) Weigh 30 grams of modified aramid fiber into the glove box. (n=50) Dissolve in the electrolyte obtained in step (1) and stir at 35°C for 10 hours to form a homogeneous solution.

[0143] (3) Add 0.2% by mass of azodicyclohexyl formonitrile to the solution obtained in step (2) and stir at 25 °C for 3 hours to prepare an in-situ polymerization precursor solution.

[0144] (4) In the glove box, drop the precursor solution obtained in step (3) onto the ternary cathode (NCM) and graphite anode respectively, and then stack the battery case, spring sheet, gasket, anode, separator and cathode sheet in sequence, and then package and assemble the battery.

[0145] (5) Take the assembled battery out of the glove box and let it stand at 50°C for 5 hours for in-situ polymerization. Then, perform charge and discharge tests, hot box tests, etc. on the battery.

[0146] Physical and chemical property tests: (1) The ionic conductivity of the above-mentioned polyimide-based overheating self-protecting polymer electrolyte was measured by AC impedance spectroscopy at room temperature (GB / T 202456(20245.3-2013)) to be 4.6 × 10⁻⁶. -4 S cm -1 .

[0147] (2) The differential thermogravimetric method was used to test the thermal decomposition temperature of the electrolyte at 452℃.

[0148] (3) The voltage stability window of the electrolyte obtained above was tested using the linear sweep voltammetry method, which is 4.67 V.

[0149] Battery performance test: (1) Charge-discharge test: At 30℃, the discharge capacity at current densities of 0.2, 1, and 5 C rates was 150 mAh g. -1 137 mAh g -1 and 124 mAh g -1 The battery retains 91.9% of its capacity after 100 1C cycles.

[0150] (2) Hot box test. The assembled battery was placed in a hot box at 150°C and heated for 30 minutes. The battery did not short circuit, catch fire or explode.

[0151] (3) External short circuit test. Assemble a 5Ah soft pack battery and short-circuit the positive and negative terminals of the battery directly with a wire. The battery does not experience thermal runaway.

[0152] (4) Needle penetration test. Using a 3 mm steel needle, the needle is vertically inserted into the center area of ​​a fully charged 10Ah battery at a speed of 25 mm / min. The battery does not catch fire or explode.

[0153] Example 9 Lithium-ion battery system with modified electrolyte application compared to Example 7 (1) Weigh 151.9 g of lithium hexafluorophosphate and add it to 354.5 g of cyclobutene sulfone. The amount of lithium salt is 25%. Stir at room temperature for 1 hour to form a low-temperature molten salt electrolyte.

[0154] (2) Weigh 30 grams of modified aramid fiber into the glove box. (n=50) Dissolve in the electrolyte obtained in step (1) and stir at 35°C for 10 hours to form a homogeneous solution.

[0155] (3) Add 0.2% by mass of azobisisobutyronitrile to the solution obtained in step (2) and stir at 25 °C for 3 hours to prepare an in-situ polymerization precursor solution.

[0156] (4) In the glove box, drop the precursor solution obtained in step (3) onto the lithium iron phosphate and graphite negative electrode respectively, and then stack the battery case, spring sheet, gasket, negative electrode, separator and positive electrode in sequence, and then package and assemble the battery.

[0157] (5) Take the assembled battery out of the glove box and let it stand at 50°C for 5 hours for in-situ polymerization. Then, perform charge and discharge tests, hot box tests, etc. on the battery.

[0158] Physical and chemical property tests: (1) The ionic conductivity of the above polyimide composite electrolyte was measured to be 2.1 × 10⁻⁶ at room temperature using AC impedance spectroscopy. -4 S cm -1 .

[0159] (2) The differential thermogravimetric method was used to test the thermal decomposition temperature of the electrolyte at 445℃.

[0160] (3) The voltage stability window of the electrolyte was tested using the linear sweep voltammetry method, which is 4.92 V.

[0161] Battery performance test: (1) Charge-discharge performance test: At 30℃, the discharge capacity at current densities of 0.2, 1, and 5 C rates was 162 mAh g. -1 152 mAh g -1and 140 mAh g -1 The battery retains 97.2% of its capacity after 100 1C cycles.

[0162] (2) The battery was placed in an environment of 130 °C for charging and discharging test. The battery did not have an internal short circuit, did not burn or explode.

[0163] (3) External short circuit test. Assemble a 5Ah soft pack battery and short-circuit the positive and negative terminals of the battery directly with a wire. The battery does not experience thermal runaway.

[0164] (4) Needle penetration test. Using a 3 mm steel needle, the needle is vertically inserted into the center area of ​​a fully charged 5Ah battery at a speed of 25 mm / min. The battery does not catch fire or explode.

[0165] Example 10 Compared with Example 7, the electrolyte application of the lithium-ion battery system was changed. (1) Weigh 151.9 g of lithium hexafluorophosphate and add it to 354.5 g of cyclobutene sulfone. The amount of lithium salt is 25%. Stir at room temperature for 1 hour to form a low-temperature molten salt electrolyte.

[0166] (2) Weigh 30 grams of modified aramid fiber into the glove box. (n=50) Dissolve in the electrolyte obtained in step (1) and stir at 35°C for 10 hours to form a homogeneous solution.

[0167] (3) Add 0.2% by mass of azobisisobutyronitrile to the solution obtained in step (2) and stir at 25 °C for 3 hours to prepare an in-situ polymerization precursor solution.

[0168] (4) In the glove box, drop the precursor solution obtained in step (3) onto the ternary cathode (NCM) and lithium metal anode respectively, and then stack the battery case, spring sheet, gasket, anode, separator and cathode sheet in sequence, and then package and assemble the battery.

[0169] (5) Take the assembled battery out of the glove box and let it stand at 50°C for 5 hours for in-situ polymerization. Then, perform charge and discharge tests, hot box tests, etc. on the battery.

[0170] Physical and chemical property tests: (1) The ionic conductivity of the above polyimide composite electrolyte was measured to be 2.5 × 10⁻⁶ at room temperature using AC impedance spectroscopy. -4 S cm -1 .

[0171] (2) The differential thermogravimetric method was used to test the thermal decomposition temperature of the electrolyte at 447℃.

[0172] (3) The voltage stability window of the electrolyte was tested using the linear sweep voltammetry method, which is 4.94 V.

[0173] Battery performance test: (1) Charge-discharge performance test: At 30℃, the discharge capacity at current densities of 0.2, 1, and 5 C rates was 193 mAh g. -1 185 mAh g -1 and 172 mAh g -1 The battery retains 94.8% of its capacity after 100 1C cycles.

[0174] (2) The battery was placed in an environment of 130 °C for charging and discharging test. The battery did not have an internal short circuit, did not burn or explode.

[0175] (3) External short circuit test. Assemble a 5Ah soft pack battery and short-circuit the positive and negative terminals of the battery directly with a wire. The battery does not experience thermal runaway.

[0176] (4) Needle penetration test. Using a 3 mm steel needle, the needle is vertically inserted into the center area of ​​a fully charged 5Ah battery at a speed of 25 mm / min. The battery does not catch fire or explode.

[0177] Example 11 Lithium-ion battery system with modified electrolyte application compared to Example 7 (1) Weigh 151.9 g of lithium hexafluorophosphate and add it to 354.5 g of cyclobutene sulfone. The amount of lithium salt is 25%. Stir at room temperature for 1 hour to form a low-temperature molten salt electrolyte.

[0178] (2) Weigh 30 grams of modified aramid fiber into the glove box. (n=50) Dissolve in the electrolyte obtained in step (1) and stir at 35°C for 10 hours to form a homogeneous solution.

[0179] (3) Add 0.2% by mass of azobisisobutyronitrile to the solution obtained in step (2) and stir at 25 °C for 3 hours to prepare an in-situ polymerization precursor solution.

[0180] (4) In the glove box, drop the precursor solution obtained in step (3) onto the ternary cathode (NCM) and silicon-carbon anode respectively, and then stack the battery case, spring sheet, gasket, anode, separator and cathode sheet in sequence, and then package and assemble the battery.

[0181] (5) Take the assembled battery out of the glove box and let it stand at 50°C for 5 hours for in-situ polymerization. Then, perform charge and discharge tests, hot box tests, etc. on the battery.

[0182] Physical and chemical property tests: (1) The ionic conductivity of the above polyimide composite electrolyte was measured to be 2.25 × 10⁻⁶ at room temperature using AC impedance spectroscopy. -4 S cm -1 .

[0183] (2) The differential thermogravimetric method was used to test the thermal decomposition temperature of the electrolyte at 441℃.

[0184] (3) The voltage stability window of the electrolyte was tested using the linear sweep voltammetry method, which is 4.97 V.

[0185] Battery performance test: (1) Charge-discharge performance test: At 30℃, the discharge capacity at current densities of 0.2, 1, and 5 C rates was 193 mAh g. -1 185 mAh g -1 and 172 mAh g -1 The battery retains 94.8% of its capacity after 100 1C cycles.

[0186] (2) The battery was placed in an environment of 130 °C for charging and discharging test. The battery did not have an internal short circuit, did not burn or explode.

[0187] (3) External short circuit test. Assemble a 5Ah soft pack battery and short-circuit the positive and negative terminals of the battery directly with a wire. The battery does not experience thermal runaway.

[0188] (4) Needle penetration test. Using a 3 mm steel needle, the needle is vertically inserted into the center area of ​​a fully charged 5Ah battery at a speed of 25 mm / min. The battery does not catch fire or explode.

[0189] Example 12 Lithium-ion battery system with modified electrolyte application compared to Example 7 (1) Weigh 151.9 g of lithium hexafluorophosphate and add it to 354.5 g of cyclobutene sulfone. The amount of lithium salt is 25%. Stir at room temperature for 1 hour to form a low-temperature molten salt electrolyte.

[0190] (2) Weigh 30 grams of modified aramid fiber into the glove box. (n=50) Dissolve in the electrolyte obtained in step (1) and stir at 35°C for 10 hours to form a homogeneous solution.

[0191] (3) Add 0.2% by mass of azobisisobutyronitrile to the solution obtained in step (2) and stir at 25 °C for 3 hours to prepare an in-situ polymerization precursor solution.

[0192] (4) In the glove box, drop the precursor solution obtained in step (3) onto the lithium-rich manganese-based positive electrode material and the silicon-carbon negative electrode respectively. Then, stack the battery case, spring sheet, gasket, negative electrode, separator and positive electrode sheet neatly in sequence, and then encapsulate and assemble the battery.

[0193] (5) Take the assembled battery out of the glove box and let it stand at 50°C for 5 hours for in-situ polymerization. Then, perform charge and discharge tests, hot box tests, etc. on the battery.

[0194] Physical and chemical property tests: (1) The ionic conductivity of the above polyimide composite electrolyte was measured to be 3.01 × 10⁻⁶ at room temperature using AC impedance spectroscopy. -4 S cm -1 .

[0195] (2) The differential thermogravimetric method was used to test the thermal decomposition temperature of the electrolyte at 443℃.

[0196] (3) The voltage stability window of the electrolyte was tested using the linear sweep voltammetry method, which is 4.85 V.

[0197] Battery performance test: (1) Charge-discharge performance test: At 30℃, the discharge capacity at current densities of 0.2, 1, and 5 C rates was 261 mAh g. -1 252 mAh g -1 and 247 mAh g -1 The battery retains 93.2% of its capacity after 100 1C cycles.

[0198] (2) The battery was placed in an environment of 130 °C for charging and discharging test. The battery did not have an internal short circuit, did not burn or explode.

[0199] (3) External short circuit test. Assemble a 5Ah soft pack battery and short-circuit the positive and negative terminals of the battery directly with a wire. The battery does not experience thermal runaway.

[0200] (4) Needle penetration test. Using a 3 mm steel needle, the needle is vertically inserted into the center area of ​​a fully charged 5Ah battery at a speed of 25 mm / min. The battery does not catch fire or explode.

[0201] Example 13 Energy storage device (sodium-ion battery) with a different electrolyte application compared to Example 7. (1) Weigh 151.9 g of lithium hexafluorophosphate and add it to 354.5 g of cyclobutene sulfone. The amount of lithium salt is 25%. Stir at room temperature for 1 hour to form a low-temperature molten salt electrolyte.

[0202] (2) Weigh 30 grams of modified aramid fiber into the glove box. (n=50) Dissolve in the electrolyte obtained in step (1) and stir at 35°C for 10 hours to form a homogeneous solution.

[0203] (3) Add 0.2% by mass of azobisisobutyronitrile to the solution obtained in step (2) and stir at 25 °C for 3 hours to prepare an in-situ polymerization precursor solution.

[0204] (4) In a glove box, the precursor solution obtained in step (3) is dropped onto the nickel-iron-manganese-based positive electrode (NFM) and the hard carbon negative electrode respectively. The battery case, spring sheet, gasket, negative electrode, separator and positive electrode are stacked neatly in sequence, and then packaged to prepare a sodium-ion battery. The battery performance is then tested. (5) Take the assembled battery out of the glove box and let it stand at 50°C for 5 hours for in-situ polymerization. Then, perform charge and discharge tests, hot box tests, etc. on the battery.

[0205] Physical and chemical property tests: (1) The ionic conductivity of the above polyimide composite electrolyte was measured to be 2.93 × 10⁻⁶ at room temperature using AC impedance spectroscopy. -4 S cm -1 .

[0206] (2) The differential thermogravimetric method was used to test the thermal decomposition temperature of the electrolyte at 433℃.

[0207] (3) The voltage stability window of the electrolyte was tested using the linear sweep voltammetry method, which is 4.80 V.

[0208] Battery performance test: (1) Charge-discharge performance test: At 30 ℃, the discharge capacities at current densities of 0.2, 1, and 5 C were 122, 110, and 99 mAh g, respectively. -1 The battery retains 97.4% of its capacity after 100 1C cycles.

[0209] (2) The battery was placed in an environment of 130 °C for charging and discharging test. The battery did not have an internal short circuit, did not burn or explode.

[0210] (3) External short circuit test. Assemble a 5Ah soft pack battery and short-circuit the positive and negative terminals of the battery directly with a wire. The battery does not experience thermal runaway.

[0211] (4) Needle penetration test. Using a 3 mm steel needle, the needle is vertically inserted into the center area of ​​a fully charged 5Ah battery at a speed of 25 mm / min. The battery does not catch fire or explode.

Claims

1. An in-situ polymerized aramid-based electrolyte, characterized in that: The electrolyte is an aramid-based polymer electrolyte formed by aramid fibers, a low-temperature molten salt electrolyte, and an initiator. The aramid fiber is one or more polymers with the following structures, where n is selected from an integer from 10 to 1000; the aramid fiber accounts for 1-45% of the electrolyte by mass; 。 2. The in-situ polymerized aramid-based polymer electrolyte according to claim 1, characterized in that: The low-temperature molten salt electrolyte is prepared by mixing organic compounds and metal salts in a certain proportion, wherein the molar ratio of organic compounds to metal salts is 1-9:1; wherein the organic compounds are one or more of acrylamide, cyclobutene sulfone, propylene-1,3-sulfonyl lactone, N-methylacrylamide, 1,3-dioxolane, cyclopentane oxide, epoxide, and trioxymethylene.

3. The in-situ polymerized aramid-based polymer electrolyte according to claim 2, characterized in that: The metal salt is a lithium or sodium salt; wherein the metal salt is lithium hexafluorophosphate, sodium hexafluorophosphate, lithium tetrafluoroborate, sodium tetrafluoroborate, lithium bis(trifluoromethanesulfonyl)imide, bis(trifluoromethanesulfonyl)imide, lithium difluorooxalate borate, sodium difluorooxalate borate, lithium bis(trifluoromethanesulfonyl)imide, or sodium bis(trifluoromethanesulfonyl)imide.

4. A method for preparing the in-situ polymerized aramid-based polymer electrolyte according to claim 1, characterized in that: S1. Mix salt and low-temperature molten salt at room temperature with stirring for 1-12 hours to form a low-temperature molten salt electrolyte; S2. Add aramid fibers to step S1 above and stir at 20-75°C for 0.5-60 hours to form a homogeneous solution; S3. Add an initiator to the solution obtained in S2 and stir at 20-45℃ for 0.1-72 hours to prepare an aramid-based polymer electrolyte precursor solution.

5. The method for preparing the in-situ polymerized aramid-based polymer electrolyte according to claim 1, characterized in that: The above-obtained aramid-based polymer electrolyte precursor solution was placed on a substrate and in-situ polymerized at 30-100°C for 0.1-72 hours to form the aramid-based polymer electrolyte.

6. The application of the in-situ polymerized aramid-based polymer electrolyte according to claim 1, characterized in that: Application of the in-situ polymerized aramid-based polymer electrolyte in the preparation of energy storage devices.

7. The application of the in-situ polymerized aramid-based polymer electrolyte according to claim 6, characterized in that: The energy storage device is a lithium secondary battery, a sodium secondary battery, or a capacitor.

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