A fibrous flexible aqueous zinc battery and a preparation method and application thereof

Abstract

This invention provides a fibrous flexible aqueous zinc battery, its preparation method, and its applications. The invention utilizes an electro-induced interfacial polymerization method to construct a tightly adhered in-situ composite hydrogel electrolyte on the electrode surface. Compared to traditional gel electrolytes, due to the enrichment of charged components under an electric field before in-situ polymerization, a stronger interfacial interaction is formed between the electrode and the composite hydrogel electrolyte, thus achieving a highly stable electrode-gel electrolyte interface. The in-situ composite hydrogel electrolyte is rich in functional groups such as amide bonds and carboxyl groups. These groups can effectively induce uniform deposition of zinc ions and inhibit the activity of free water molecules at the interface, thereby effectively suppressing dendrite growth and undesirable side reactions, and effectively improving the cycle stability of the aqueous zinc battery under high zinc utilization. The flexible aqueous zinc battery of this invention can be applied to wearable electronic devices, providing a safe, high-performance, and highly stable power supply solution for next-generation flexible wearable devices.

Description

Technical Field

[0001] This invention relates to the field of zinc-ion battery technology, and in particular to a fibrous flexible aqueous zinc battery, its preparation method, and its application. Background Technology

[0002] With the rapid development of flexible electronics technology and the Internet of Things (IoT), wearable devices are increasingly widely used in fields such as motion monitoring, medical and health diagnosis, and human-computer interaction. As a core power supply component for wearable devices, flexible batteries need to meet stringent requirements such as high energy density, long-term cycle stability, and excellent mechanical flexibility. Among them, fibrous flexible aqueous zinc batteries, with their high safety, high theoretical specific capacity, environmental friendliness, and good flexibility, are considered one of the most promising batteries for next-generation smart wearable devices. However, aqueous zinc batteries suffer from bottlenecks such as zinc dendrite growth, side reactions, and low zinc utilization, severely limiting their development and practical application. Current solutions to these problems mainly include zinc anode design, separator improvement, electrolyte additive design, and polymer gel electrolyte design. Among these, using polymer gel electrolytes is one method to alleviate the problems associated with zinc anodes. Furthermore, compared with liquid electrolytes, batteries based on gel electrolytes have stronger leakage resistance and higher mechanical flexibility, showing great development potential. However, unlike traditional planar flexible electrodes, the high curvature of one-dimensional flexible fiber electrodes makes it more difficult to form a stable electrode-electrolyte interface with gel electrolytes, easily leading to severe interfacial separation, especially when the battery is subjected to various mechanical deformations. Interfacial separation causes a rapid decline in the performance of fiber zinc batteries, including shortened cycle life, reduced coulombic efficiency, and decreased flexibility. More importantly, in order to maintain the cycle stability of the battery, most reported fiber zinc batteries currently employ extremely low zinc utilization rates, which greatly sacrifices the actual energy density of the battery and seriously hinders its large-scale application.

[0003] Therefore, there is an urgent need to develop high-performance flexible aqueous fiber zinc batteries with a stable fiber electrode-gel electrolyte interface and the ability to achieve long-term stable cycling under high zinc utilization, in order to meet the development and practical application needs of next-generation wearable devices. Summary of the Invention

[0004] To address the shortcomings of high-curvature flexible fiber electrodes in forming a stable electrode-electrolyte interface with gel electrolytes and in achieving stable cycling under high zinc utilization, this invention provides a fibrous flexible aqueous zinc battery, its preparation method, and its applications. This invention utilizes a highly controllable one-step electro-induced interfacial polymerization method to construct a tightly adhered in-situ composite hydrogel electrolyte on the surface of a high-curvature electrode. Compared to traditional gel electrolytes, the in-situ polymerization method, with its pre-polymerization enrichment of charged components under an electric field, results in a stronger interfacial interaction between the electrode and the composite hydrogel electrolyte, thus achieving a highly stable electrode-gel electrolyte interface. Furthermore, the in-situ composite hydrogel electrolyte is rich in functional groups such as amide bonds and carboxyl groups. These groups effectively induce uniform zinc ion deposition and inhibit the activity of free water molecules at the interface, thereby effectively suppressing dendrite growth and undesirable side reactions, and significantly improving the cycling stability of the aqueous zinc battery under high zinc utilization.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] In a first aspect, the present invention provides a method for preparing a fibrous flexible aqueous zinc battery, comprising the following steps:

[0007] Prepare hydrogel electrolyte precursor solution;

[0008] The positive and negative electrodes are placed in the hydrogel electrolyte precursor solution, and an electric current is applied to the hydrogel electrolyte precursor solution to form hydrogel electrolyte on the surface of the positive and negative electrodes.

[0009] The hydrogel electrolyte is then immersed in a zinc salt solution;

[0010] The hydrogel electrolyte precursor solution includes sodium alginate, attapulgite, acrylamide, N,N'-methylenebisacrylamide, persulfate, and water.

[0011] Preferably, the positive and negative electrodes are placed in the hydrogel electrolyte precursor solution, and the counter electrode is also placed in the hydrogel electrolyte precursor solution. The positive and negative electrodes are both used as working electrodes and connected to the positive terminal of the power supply, while the counter electrode is connected to the negative terminal of the power supply. A constant current of 1~20 mA is applied to the working electrode and the counter electrode for 10~600 s to prepare the hydrogel electrolyte on the surface of the positive and negative electrodes.

[0012] Preferably, the concentration of sodium alginate in the hydrogel electrolyte precursor solution is 1~200 mg / mL, the concentration of attapulgite is 1~400 mg / mL, the concentration of acrylamide is 1~100 mg / mL, the concentration of N,N'-methylenebisacrylamide is 0.01~1 mg / mL, and the concentration of persulfate is 0.05~10 mg / mL.

[0013] The persulfate includes at least one of potassium persulfate and ammonium persulfate.

[0014] Preferably, the positive electrode comprises carbon fiber and polyaniline located on the surface of the carbon fiber.

[0015] Preferably, the method for preparing the positive electrode includes the following steps:

[0016] Aniline monomer is mixed with hydrochloric acid solution to obtain aniline monomer solution;

[0017] Carbon fibers are immersed in an aniline monomer solution, and then persulfate is added to the aniline monomer solution. The immersion continues to form polyaniline on the surface of the carbon fibers.

[0018] Preferably, the concentration of the hydrochloric acid solution is 0.5~2 mol / L;

[0019] The volume ratio of the aniline monomer to the hydrochloric acid solution is 1:(10~200);

[0020] The molar ratio of persulfate to hydrochloric acid is 1:(2~10); the persulfate includes at least one of potassium persulfate and ammonium persulfate;

[0021] The diameter of the carbon fiber is 0.05 ~ 0.3 mm.

[0022] Preferably, in the step of immersing carbon fibers in an aniline monomer solution, the immersion temperature is 0~5℃ and the immersion time is 0.1~3h;

[0023] In the step of adding persulfate to the aniline monomer solution and continuing the soaking, the soaking temperature is 0~5℃ and the soaking time is 0.1~3h.

[0024] Preferably, in the step of immersing the hydrogel electrolyte in the zinc salt solution, the immersion time is 1~60 min;

[0025] The zinc salt in the zinc salt solution includes at least one of zinc sulfate, zinc trifluoromethanesulfonate, zinc nitrate, zinc chloride, and zinc acetate;

[0026] The concentration of the zinc salt solution is 0.1~5 mol / L.

[0027] Preferably, the negative electrode is a zinc wire, and the diameter of the zinc wire is 0.1~2mm;

[0028] Alternatively, the negative electrode comprises carbon fibers and a zinc plating layer on the surface of the carbon fibers, and the method for preparing the negative electrode includes the following steps:

[0029] Carbon fiber is placed in a Zn electroplating solution with a concentration of 0.1~2 mol / L and an anode is placed in the Zn electroplating solution. The carbon fiber is used as the cathode and connected to the negative terminal of the power supply, and the anode is connected to the positive terminal of the power supply. Electroplating is performed to form a zinc coating on the surface of the carbon fiber.

[0030] The electroplating current is 0.1~1 mA, the electroplating time is 5~60 s, and the anode is zinc wire or zinc foil.

[0031] Secondly, the present invention also provides a flexible aqueous zinc battery, which is prepared using the aforementioned preparation method.

[0032] Thirdly, the present invention also provides a fibrous flexible aqueous zinc battery prepared by the preparation method described above, or the application of the fibrous flexible aqueous zinc battery described above in wearable electronic devices.

[0033] The fibrous flexible aqueous zinc battery of the present invention, its preparation method, and its application have the following advantages compared with the prior art:

[0034] 1. The method for preparing the fibrous flexible aqueous zinc battery of the present invention involves constructing a tightly adhered in-situ composite hydrogel electrolyte on the electrode surface through electro-induced interfacial polymerization. Compared with traditional gel electrolytes, due to the enrichment of charged components under the action of an electric field before in-situ polymerization, a stronger interfacial interaction is formed between the electrode and the composite hydrogel electrolyte, thereby achieving a highly stable fibrous electrode-gel electrolyte interface. Furthermore, the in-situ composite hydrogel electrolyte is rich in functional groups such as amide bonds and carboxyl groups. These groups can effectively induce uniform deposition of zinc ions and inhibit the activity of free water molecules at the interface, thereby effectively suppressing dendrite growth and undesirable side reactions, and effectively improving the cycle stability of the aqueous fiber zinc battery under high zinc utilization. This invention provides a flexible aqueous zinc battery that combines low cost, high safety, high performance, and excellent flexibility. It achieves a highly stable fibrous electrode-gel electrolyte interface and excellent electrochemical performance using a very simple method, providing a highly safe, high-performance, and highly stable power supply solution for next-generation flexible wearable devices.

[0035] 2. The present invention relates to a fibrous flexible zinc-zinc symmetric battery based on an electrically induced in-situ composite hydrogel electrolyte, which can stably charge and discharge cycle for 240-300 h with a high zinc utilization rate of 85.4%; the fibrous flexible zinc-ion full cell based on an electrically induced in-situ composite hydrogel electrolyte, with a high zinc utilization rate of N / P ratio of 2.55, retains a capacity of 90.43-92.31% after 1500 charge and discharge cycles, and has an average coulombic efficiency of 99.56-99.94%; after being subjected to 3000 bending deformations, its capacity retention rate is 99.2-99.9% of that before bending. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a schematic diagram of the structure of the fibrous flexible aqueous zinc battery of the present invention;

[0038] Figure 2 This is a scanning electron microscope image of the interface between the flexible positive electrode and the in-situ composite hydrogel electrolyte in Example 1;

[0039] Figure 3 The cycling performance curves of the fibrous flexible zinc||zinc symmetric battery prepared in Example 1 are shown.

[0040] Figure 4 The cycling performance curve of the fibrous flexible zinc-ion full cell prepared in Example 1 is shown.

[0041] Figure 5 The charge-discharge curves of the fibrous flexible zinc-ion full cell prepared in Example 1 before and after 3000 consecutive bending at 180°.

[0042] Figure 6 This is a photograph of the fibrous flexible zinc-ion full battery prepared in Example 1 woven into a wristband to power a wearable LED light strip. Detailed Implementation

[0043] The technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0044] It should be noted that the order of description of the following embodiments is not intended to limit the preferred order of embodiments. Furthermore, in the description of this application, the term "comprising" means "including but not limited to". Various embodiments of the present invention may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a rigid limitation on the scope of the invention; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single digits within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Additionally, whenever a numerical range is indicated herein, it means including any referenced number (fraction or integer) within the indicated range.

[0045] This application provides a method for preparing a fibrous flexible aqueous zinc battery, comprising the following steps:

[0046] S1. Prepare hydrogel electrolyte precursor solution;

[0047] S2. Place the positive and negative electrodes in the hydrogel electrolyte precursor solution and apply current to the hydrogel electrolyte precursor solution to form hydrogel electrolyte on the surface of the positive and negative electrodes.

[0048] S3. Then immerse the hydrogel electrolyte in the zinc salt solution;

[0049] The hydrogel electrolyte precursor solution includes sodium alginate, attapulgite, acrylamide, N,N'-methylenebisacrylamide, persulfate, and water.

[0050] The method for preparing the fibrous flexible aqueous zinc battery of the present invention involves directly preparing the hydrogel electrolyte on the electrode surface using an electro-induced interfacial polymerization method to achieve a highly stable electrode-gel electrolyte interface. The gel electrolyte contains sodium alginate rich in carboxyl groups and polyacrylamide rich in amide groups; these functional groups can effectively inhibit the growth of zinc dendrites and the occurrence of side reactions, thereby improving the electrochemical performance of the battery. Specifically, a schematic diagram of the gas structure of the fibrous flexible aqueous zinc battery prepared by the present invention is shown below. Figure 1 As shown, it includes a positive electrode 1, a negative electrode 2, and a hydrogel electrolyte 3, wherein the hydrogel electrolyte 3 is prepared by the above-mentioned electro-induced interfacial polymerization method.

[0051] This invention utilizes a highly controllable one-step electro-induced interfacial polymerization method to construct a tightly adhered in-situ composite hydrogel electrolyte on the electrode surface. Compared to traditional gel electrolytes, the in-situ polymerization method, with its pre-polymerization enrichment of charged components under an electric field, fosters stronger interfacial interactions between the fiber electrode and the composite hydrogel electrolyte, resulting in a highly stable fiber electrode-gel electrolyte interface. Furthermore, the in-situ composite hydrogel electrolyte is rich in functional groups such as amide bonds and carboxyl groups. These groups effectively induce uniform zinc ion deposition and inhibit the activity of free water molecules at the interface, thereby effectively suppressing dendrite growth and undesirable side reactions, and significantly improving the cycle stability of the aqueous fiber zinc battery under high zinc utilization. This invention provides a flexible aqueous zinc battery that combines low cost, high safety, high performance, and excellent flexibility. It achieves a highly stable fiber electrode-gel electrolyte interface and excellent electrochemical performance using a very simple method, providing a safe, high-performance, and highly stable power supply solution for next-generation flexible wearable devices.

[0052] In some embodiments, the positive and negative electrodes are placed in the hydrogel electrolyte precursor solution (the lower ends of the positive and negative electrodes extend into the precursor solution, and the upper ends extend out of the precursor solution and are connected to the positive terminal of the power supply). Simultaneously, the counter electrode (which can be a stainless steel wire or copper wire, etc.) is placed in the hydrogel electrolyte precursor solution. Both the positive and negative electrodes serve as working electrodes (the positive and negative electrodes are placed parallel to each other and both serve as working electrodes) and are connected to the positive terminal of the power supply. The counter electrode is connected to the negative terminal of the power supply. An application of 1~20°C is applied to the working and counter electrodes. A constant current of mA for 10~600s is used to prepare hydrogel electrolytes on the surfaces of the positive and negative electrodes. In this invention, an electro-induced interfacial polymerization method is used to construct a tightly adhered in-situ composite hydrogel electrolyte on the electrode surface. The specific steps are as follows: the working electrode and the counter electrode are immersed in the hydrogel electrolyte precursor solution, so that the precursor solution fully penetrates the surface of the electrodes to achieve close contact between the two; an appropriate current is applied, and the electric field will cause the local enrichment of charged components on the surface of the fiber electrode; at the same time, the interfacial polymerization reaction is triggered, thereby preparing a stably adhered in-situ composite hydrogel on the electrode.

[0053] Specifically, the power source can be an electrochemical workstation. The working electrode is connected to the working electrode interface of the electrochemical workstation, and the counter electrode is connected to the counter electrode interface of the electrochemical workstation. Specifically, the positive and negative electrodes are immersed in a precursor solution, and an appropriate current is applied. The electric field causes localized enrichment of charged substances on the electrode surface. For example, the negative electrode is a zinc wire or carbon fiber and a zinc coating on the surface of the carbon fiber. Under the action of the current, zinc releases zinc ions, which complex with the carboxyl groups on sodium alginate to form a sodium alginate hydrogel network. Simultaneously, the persulfate free radicals enriched on the electrode surface are reduced to sulfate free radicals, initiating an acrylamide free radical polymerization reaction to form an acrylamide hydrogel network. The two gel networks constitute an in-situ composite hydrogel electrolyte.

[0054] In some embodiments, the distance between the working electrode and the counter electrode is 0.5 to 3 cm.

[0055] In some embodiments, the concentration of sodium alginate in the hydrogel electrolyte precursor solution is 1~200 mg / mL, the concentration of attapulgite is 1~400 mg / mL, the concentration of acrylamide is 1~100 mg / mL, and the concentration of N,N'-methylenebisacrylamide (CAS No. 110-26-9, chemical formula C7H) is... 10 The concentration of N2O2 is 0.01~1 mg / mL, and the concentration of persulfate is 0.05~10 mg / mL. Persulfate includes at least one of potassium persulfate and ammonium persulfate.

[0056] Specifically, the preparation method of the above-mentioned hydrogel electrolyte precursor solution includes the following steps:

[0057] S1. Dissolve sodium alginate and attapulgite in deionized water and stir well. Stirring at 40~80℃ can accelerate the dissolution.

[0058] S2. Add acrylamide, N,N'-methylenebisacrylamide and persulfate to the solution in step S1, and stir until homogeneous to obtain the hydrogel electrolyte precursor solution.

[0059] In some embodiments, the positive electrode comprises carbon fiber and polyaniline on the surface of the carbon fiber, wherein the diameter of the carbon fiber is 0.05 mm to 0.3 mm.

[0060] In some embodiments, polyaniline is directly prepared on carbon fiber via chemical oxidation of the positive electrode, specifically including the following steps:

[0061] S1. Mix aniline (molecular formula C6H7N) monomer with hydrochloric acid solution to obtain aniline monomer solution;

[0062] S2. Immerse the carbon fiber in an aniline monomer solution, then add persulfate to the aniline monomer solution and continue immersing to form polyaniline on the carbon fiber surface. Take out the reacted carbon fiber and immerse it in deionized water and ethanol for 2-60 minutes respectively. Then dry it in a vacuum drying oven at 40-100 ℃ for 2-12 hours to obtain a flexible positive electrode.

[0063] In some embodiments, the concentration of the hydrochloric acid solution is 0.5~2 mol / L;

[0064] The volume ratio of aniline monomer to hydrochloric acid solution is 1:(10~200);

[0065] The molar ratio of persulfate to hydrochloric acid is 1:(2~10). Persulfate can also be potassium persulfate or ammonium persulfate.

[0066] In some embodiments, in the step of immersing carbon fibers in an aniline monomer solution, the immersion temperature is 0~5℃ and the immersion time is 0.1~3h;

[0067] In the step of adding persulfate to the aniline monomer solution and continuing the soaking, the soaking temperature is 0~5℃ and the soaking time is 0.1~3h.

[0068] In some embodiments, the step of immersing the hydrogel electrolyte in a zinc salt solution is performed for 1 to 60 minutes.

[0069] Specifically, the zinc salt solution is an aqueous solution of zinc salts, and the zinc salts in the zinc salt solution include at least one of zinc sulfate, zinc trifluoromethanesulfonate, zinc nitrate, zinc chloride, and zinc acetate;

[0070] The concentration of the zinc salt solution is 0.1~5 mol / L;

[0071] In some embodiments, the negative electrode is a zinc wire with a diameter of 0.1 mm to 2 mm.

[0072] In some embodiments, the negative electrode includes carbon fibers and a zinc plating layer on the surface of the carbon fibers, and the method for preparing the negative electrode includes the following steps:

[0073] Carbon fibers (0.05 mm to 0.3 mm in diameter) are placed in a Zn electroplating solution with a concentration of 0.1 to 2 mol / L, and an anode is placed in the Zn electroplating solution. The carbon fiber is used as the cathode and connected to the negative terminal of the power supply, and the anode is connected to the positive terminal of the power supply. Electroplating is performed to form a zinc coating on the surface of the carbon fiber.

[0074] The electroplating current is 0.1~1 mA, and the electroplating time is 5~60 s; the anode can be zinc wire or zinc foil, and the Zn electroplating solution can be zinc sulfate solution, zinc trifluoromethanesulfonate solution, zinc nitrate solution, zinc chloride solution, zinc acetate solution, etc.

[0075] In some embodiments, the fibrous flexible aqueous zinc battery is a fibrous flexible zinc||zinc symmetric battery, and its preparation method includes:

[0076] S1. Use two parallel zinc wires as working electrodes and stainless steel or copper wire as counter electrodes. Immerse the working electrode and counter electrode in the hydrogel electrolyte precursor solution.

[0077] S2. Using an electrochemical workstation, a constant current of 1-20 mA is applied to the working electrode and the counter electrode for 10-600 seconds to prepare an in-situ composite hydrogel electrolyte on the surface of the zinc electrode.

[0078] S3. Immerse the hydrogel electrolyte from S2 in a 0.1-5 mol / L zinc salt solution for 1-60 minutes; then encapsulate it in a heat shrink tubing using UV-curing adhesive to successfully prepare a flexible zinc-zinc symmetric battery.

[0079] In some embodiments, the fibrous flexible aqueous zinc battery is a fibrous flexible zinc-ion full battery, and its preparation method includes:

[0080] S1. Two parallel negative electrodes and a fiber positive electrode (including carbon fiber and polyaniline on the surface of carbon fiber, with the negative and positive electrodes connected in parallel) are used as working electrodes. Stainless steel wire or copper wire is used as the counter electrode. The working electrode and the counter electrode are immersed in the hydrogel electrolyte precursor solution.

[0081] The negative electrode comprises carbon fiber and a zinc coating on the surface of the carbon fiber. The preparation method of the negative electrode includes the following steps:

[0082] Carbon fibers (0.05 mm to 0.3 mm in diameter) are placed in a Zn electroplating solution with a concentration of 0.1 to 2 mol / L, and an anode is placed in the Zn electroplating solution. The carbon fiber is used as the cathode and connected to the negative terminal of the power supply, and the anode is connected to the positive terminal of the power supply. Electroplating is performed to form a zinc coating on the surface of the carbon fiber.

[0083] The electroplating current is 0.1~1 mA, and the electroplating time is 5~60 s; the anode can be zinc wire or zinc foil, and the Zn electroplating solution can be zinc sulfate solution, zinc trifluoromethanesulfonate solution, zinc nitrate solution, zinc chloride solution, zinc acetate solution, etc.

[0084] S2. Using an electrochemical workstation, a constant current of 1-20 mA is applied to the working electrode and the counter electrode for 10-600 seconds to prepare an in-situ composite hydrogel electrolyte on the surface of the zinc electrode.

[0085] S3. Soak the hydrogel electrolyte in S2 in a 0.1~5 mol / L zinc salt solution for 1~60 minutes; then encapsulate it in a heat shrink tubing using UV-curing adhesive to successfully prepare a flexible zinc-ion full battery.

[0086] This invention relates to a fibrous flexible zinc-zinc symmetric battery based on an electrically induced in-situ composite hydrogel electrolyte, which can stably perform charge-discharge cycles for 240-300 hours with a high zinc utilization rate of 85.4%. The fibrous flexible zinc-ion full cell based on the electrically induced in-situ composite hydrogel electrolyte, with a high zinc utilization rate of 2.55 N / P ratio, retains a capacity of 90.43-92.31% after 1500 charge-discharge cycles, and has an average coulombic efficiency as high as 99.56-99.94%. After withstanding 3000 bending deformations, its capacity retention rate is 99.2-99.9% of the value before bending.

[0087] Based on the same inventive concept, the present invention also provides a fibrous flexible aqueous zinc battery, which is prepared by the above-described preparation method.

[0088] Based on the same inventive concept, the present invention also provides a fibrous flexible aqueous zinc battery prepared by the above-described preparation method or the application of the above-described fibrous flexible aqueous zinc battery in wearable electronic devices.

[0089] The following detailed embodiments further illustrate the preparation method of the fibrous flexible aqueous zinc battery of this application. This section, in conjunction with specific embodiments, further explains the content of the present invention, but should not be construed as limiting the present invention. Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art. Unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in the art.

[0090] Example 1

[0091] This embodiment provides a method for preparing a fibrous flexible aqueous zinc battery, including the following steps:

[0092] S1. Prepare a flexible positive electrode, including the following steps:

[0093] S11. Mix aniline monomer with hydrochloric acid solution at 0℃ to obtain aniline monomer solution; the concentration of hydrochloric acid solution is 1 mol / L, and the volume ratio of aniline monomer to hydrochloric acid solution is 1:40;

[0094] S12. Immerse carbon fibers (average diameter 0.2 mm) in an aniline monomer solution at 0°C for 1 hour; then add ammonium persulfate to the aniline monomer solution and continue immersing at 0°C for another hour to form polyaniline on the surface of the carbon fibers; the molar ratio of ammonium persulfate to hydrochloric acid is 1:5; remove the reacted carbon fibers and immerse them in deionized water and ethanol for 15 minutes each, then dry them in a vacuum drying oven at 60°C for 8 hours to obtain a flexible positive electrode;

[0095] S2. Preparation of hydrogel electrolyte precursor solution, including the following steps:

[0096] S21. Dissolve sodium alginate and attapulgite in deionized water and stir at 70°C to accelerate dissolution.

[0097] S22. Add acrylamide, N,N'-methylenebisacrylamide and potassium persulfate to the solution in step S21, stir until homogeneous to obtain hydrogel electrolyte precursor solution;

[0098] The hydrogel electrolyte precursor solution contained sodium alginate at a concentration of 40 mg / mL, attapulgite at a concentration of 60 mg / mL, acrylamide at a concentration of 10 mg / mL, N,N'-methylenebisacrylamide at a concentration of 0.05 mg / mL, and potassium persulfate at a concentration of 1.0 mg / mL.

[0099] S3. Preparation of fibrous flexible zinc-zinc symmetric cells, including the following steps:

[0100] S31. Two parallel zinc wires (average diameter 0.3 mm) are used together as the working electrode, and a stainless steel wire is used as the counter electrode. The working electrode and the counter electrode are immersed in the hydrogel electrolyte precursor solution prepared in step S2.

[0101] S32. Using an electrochemical workstation, a constant current of 5 mA is applied to the working electrode and the counter electrode (the distance between the working electrode and the counter electrode is 2 cm) for 60 seconds, thereby preparing an in-situ composite hydrogel electrolyte on the surface of the zinc wire electrode.

[0102] S33. Soak the hydrogel electrolyte in S32 in a 2 mol / L zinc sulfate aqueous solution for 10 minutes, and then encapsulate it in a heat shrink tube using UV curing adhesive to successfully prepare a fibrous flexible zinc||zinc symmetric battery.

[0103] S4. Preparation of fibrous flexible zinc-ion full cells, including the following steps:

[0104] S41. Using the negative electrode and the flexible positive electrode prepared in step S1 together as the working electrode, and using stainless steel wire as the counter electrode, the working electrode and the counter electrode are immersed in the hydrogel electrolyte precursor solution prepared in step S2.

[0105] The negative electrode comprises carbon fibers and a zinc coating on the surface of the carbon fibers. The preparation method of the negative electrode includes the following steps:

[0106] Carbon fibers (average diameter 0.2 mm) were placed in a 2 mol / L Zn electroplating solution (specifically a 2 mol / L zinc sulfate aqueous solution), and an anode (specifically a zinc wire with an average diameter of 0.3 mm) was placed in the Zn electroplating solution. The carbon fibers were connected as the cathode to the negative terminal of the power supply, and the anode was connected to the positive terminal of the power supply. Electroplating was carried out at room temperature (25°C) to form a zinc coating on the surface of the carbon fibers. The electroplating current was 1 mA and the electroplating time was 30 s.

[0107] S42. Using an electrochemical workstation, a constant current of 5 mA is applied to the working electrode and the counter electrode (the distance between the working electrode and the counter electrode is 2 cm) for 60 seconds, thereby preparing an in-situ composite hydrogel electrolyte on the surface of the zinc wire and the flexible positive electrode.

[0108] S43. Soak the hydrogel electrolyte in S42 in a 2 mol / L zinc sulfate aqueous solution for 10 minutes, and then encapsulate it in a heat shrink tube using UV curing adhesive to successfully prepare a fibrous flexible zinc-ion full battery.

[0109] The fibrous flexible zinc-zinc symmetric battery prepared in Example 1 above can be stably cycled for 300 hours at a high zinc utilization rate of 85.4%; the fibrous flexible zinc-ion full cell prepared in Example 1 retains 92.31% of its capacity after 1500 cycles at a low N / P ratio of 2.55, with an average coulombic efficiency of 99.94%; and it still retains 99.9% of its capacity after 3000 bending cycles, proving that the zinc battery has excellent interface stability and flexibility.

[0110] Example 2

[0111] This embodiment provides a method for preparing a fibrous flexible aqueous zinc battery, including the following steps:

[0112] S1. Prepare a flexible positive electrode, including the following steps:

[0113] S11. Mix aniline monomer with hydrochloric acid solution at 0℃ to obtain aniline monomer solution; the concentration of hydrochloric acid solution is 0.5 mol / L, and the volume ratio of aniline monomer to hydrochloric acid solution is 1:200;

[0114] S12. Immerse carbon fibers (average diameter 0.2 mm) in an aniline monomer solution at 0 °C for 0.1 h; then add ammonium persulfate to the aniline monomer solution and continue immersing at 0 °C for another 0.1 h to form polyaniline on the surface of the carbon fibers; the molar ratio of ammonium persulfate to hydrochloric acid is 1:10; remove the reacted carbon fibers and immerse them in deionized water and ethanol for 2 minutes each, then dry them in a vacuum drying oven at 40 °C for 12 h to obtain a flexible positive electrode;

[0115] S2. Preparation of hydrogel electrolyte precursor solution, including the following steps:

[0116] S21. Dissolve sodium alginate and attapulgite in deionized water and stir at 40°C to accelerate dissolution.

[0117] S22. Add acrylamide, N,N'-methylenebisacrylamide and potassium persulfate to the solution in step S21, stir until homogeneous to obtain hydrogel electrolyte precursor solution;

[0118] The hydrogel electrolyte precursor solution contained sodium alginate at a concentration of 1 mg / mL, attapulgite at a concentration of 1 mg / mL, acrylamide at a concentration of 100 mg / mL, N,N'-methylenebisacrylamide at a concentration of 1 mg / mL, and potassium persulfate at a concentration of 10 mg / mL.

[0119] S3. Preparation of fibrous flexible zinc-zinc symmetric cells, including the following steps:

[0120] S31. Two parallel zinc wires (average diameter 0.3 mm) are used together as the working electrode, and a stainless steel wire is used as the counter electrode. The working electrode and the counter electrode are immersed in the hydrogel electrolyte precursor solution prepared in step S2.

[0121] S32. Using an electrochemical workstation, a constant current of 1 mA was applied to the working electrode and the counter electrode (the distance between the working electrode and the counter electrode was 2 cm) for 600 seconds, thereby preparing an in-situ composite hydrogel electrolyte on the surface of the zinc wire electrode.

[0122] S33. The hydrogel electrolyte in S32 is immersed in a 0.1 mol / L zinc trifluoromethanesulfonate aqueous solution for 60 minutes, and then encapsulated in a heat shrink tube using UV curing adhesive to successfully prepare a fibrous flexible zinc||zinc symmetric battery.

[0123] S4. Preparation of fibrous flexible zinc-ion full cells, including the following steps:

[0124] S41. Using the negative electrode and the flexible positive electrode prepared in step S1 together as the working electrode, and using stainless steel wire as the counter electrode, the working electrode and the counter electrode are immersed in the hydrogel electrolyte precursor solution prepared in step S2.

[0125] The negative electrode comprises carbon fibers and a zinc coating on the surface of the carbon fibers. The preparation method of the negative electrode includes the following steps:

[0126] Carbon fibers (average diameter 0.2 mm) were placed in a 2 mol / L Zn electroplating solution (specifically a 2 mol / L zinc sulfate aqueous solution), and an anode (specifically a zinc wire with an average diameter of 0.3 mm) was placed in the Zn electroplating solution. The carbon fibers were connected to the negative terminal of the power supply as the cathode, and the zinc anode was connected to the positive terminal of the power supply. Electroplating was carried out at room temperature (25°C) to form a zinc coating on the surface of the carbon fibers. The electroplating current was 1 mA and the electroplating time was 30 s.

[0127] S42. Using an electrochemical workstation, a constant current of 1 mA is applied to the working electrode and the counter electrode (the distance between the working electrode and the counter electrode is 2 cm) for 600 seconds, thereby preparing an in-situ composite hydrogel electrolyte on the surface of the zinc wire and the flexible positive electrode.

[0128] S43. The hydrogel electrolyte in S42 is immersed in a 0.1 mol / L zinc trifluoromethanesulfonate aqueous solution for 60 minutes, and then encapsulated in a heat shrink tube using UV-curing adhesive to successfully prepare a fibrous flexible zinc-ion full battery.

[0129] The fibrous flexible zinc-zinc symmetric battery prepared in Example 2 above can be stably cycled for 240 hours at a high zinc utilization rate of 85.4%; the fibrous flexible zinc-ion full cell prepared in Example 2 retains 90.43% of its capacity after 1500 cycles at a low N / P ratio of 2.55, with an average coulombic efficiency of 99.56%; and retains 99.2% of its capacity after 3000 bending cycles, proving that the zinc battery has excellent interface stability and flexibility.

[0130] Example 3

[0131] This embodiment provides a method for preparing a fibrous flexible aqueous zinc battery, including the following steps:

[0132] S1. Prepare a flexible positive electrode, including the following steps:

[0133] S11. Aniline monomer and hydrochloric acid solution are mixed at 0℃ to obtain aniline monomer solution; the concentration of hydrochloric acid solution is 2 mol / L, and the volume ratio of aniline monomer to hydrochloric acid solution is 1:10.

[0134] S12. Immerse carbon fibers (average diameter 0.2 mm) in an aniline monomer solution at 0°C for 3 hours; then add ammonium persulfate to the aniline monomer solution and continue immersing at 0°C for 3 hours to form polyaniline on the surface of the carbon fibers; the molar ratio of ammonium persulfate to hydrochloric acid is 1:2; remove the reacted carbon fibers and immerse them in deionized water and ethanol for 60 minutes each, then dry them in a vacuum drying oven at 100°C for 2 hours to obtain a flexible positive electrode;

[0135] S2. Preparation of hydrogel electrolyte precursor solution, including the following steps:

[0136] S21. Dissolve sodium alginate and attapulgite in deionized water and stir at 80°C to accelerate dissolution.

[0137] S22. Add acrylamide, N,N'-methylenebisacrylamide and potassium persulfate to the solution in step S21, stir until homogeneous to obtain hydrogel electrolyte precursor solution;

[0138] The hydrogel electrolyte precursor solution contained sodium alginate at a concentration of 200 mg / mL, attapulgite at a concentration of 400 mg / mL, acrylamide at a concentration of 1 mg / mL, N,N'-methylenebisacrylamide at a concentration of 0.01 mg / mL, and potassium persulfate at a concentration of 0.05 mg / mL.

[0139] S3. Preparation of fibrous flexible zinc-zinc symmetric cells, including the following steps:

[0140] S31. Two parallel zinc wires (average diameter 0.3 mm) are used together as the working electrode, and a stainless steel wire is used as the counter electrode. The working electrode and the counter electrode are immersed in the hydrogel electrolyte precursor solution prepared in step S2.

[0141] S32. Using an electrochemical workstation, a constant current of 20 mA is applied to the working electrode and the counter electrode (the distance between the working electrode and the counter electrode is 2 cm) for 10 seconds, thereby preparing an in-situ composite hydrogel electrolyte on the surface of the zinc wire electrode.

[0142] S33. Soak the hydrogel electrolyte in S32 in a 5 mol / L zinc chloride aqueous solution for 1 minute, and then encapsulate it in a heat shrink tube using UV curing adhesive to successfully prepare a fibrous flexible zinc||zinc symmetric battery.

[0143] S4. Preparation of fibrous flexible zinc-ion full cells, including the following steps:

[0144] S41. Using the negative electrode and the flexible positive electrode prepared in step S1 together as the working electrode, and using stainless steel wire as the counter electrode, the working electrode and the counter electrode are immersed in the hydrogel electrolyte precursor solution prepared in step S2.

[0145] The negative electrode comprises carbon fibers and a zinc coating on the surface of the carbon fibers. The preparation method of the negative electrode includes the following steps:

[0146] Carbon fibers (average diameter 0.2 mm) were placed in a 2 mol / L Zn electroplating solution (specifically a 2 mol / L zinc sulfate aqueous solution), and an anode (specifically a zinc wire with an average diameter of 0.3 mm) was placed in the Zn electroplating solution. The carbon fibers were connected to the negative terminal of the power supply as the cathode, and the zinc anode was connected to the positive terminal of the power supply. Electroplating was carried out at room temperature (25°C) to form a zinc coating on the surface of the carbon fibers. The electroplating current was 1 mA and the electroplating time was 30 s.

[0147] S42. Using an electrochemical workstation, a constant current of 20 mA is applied to the working electrode and the counter electrode (the distance between the working electrode and the counter electrode is 2 cm) for 10 seconds, thereby preparing an in-situ composite hydrogel electrolyte on the surface of the zinc wire and the flexible positive electrode.

[0148] S43. Soak the hydrogel electrolyte in S42 in a 5 mol / L zinc chloride aqueous solution for 1 minute, and then encapsulate it in a heat shrink tube using UV-curing adhesive to successfully prepare a fibrous flexible zinc-ion full battery.

[0149] The fibrous flexible zinc-zinc symmetric battery prepared in Example 3 above can be stably cycled for 280 hours at a high zinc utilization rate of 85.4%; the fibrous flexible zinc-ion full cell prepared in Example 3 retains 91.75% of its capacity after 1500 cycles at a low N / P ratio of 2.55, with an average coulombic efficiency of 99.87%; and it still retains 99.5% of its capacity after 3000 bending cycles, proving that the zinc battery has excellent interface stability and flexibility.

[0150] Figure 2 The flexible positive electrode in Example 1 (i.e. Figure 2 Medium fiber electrode) and in-situ composite hydrogel electrolyte (i.e. Figure 2 Scanning electron microscope (SEM) image of the interface between the in-situ gel electrolyte and the electrolyte. Figure 2 It can be seen that the flexible positive electrode and the in-situ composite gel electrolyte have a close contact and a stable interface.

[0151] Figure 3 The cycling performance curve of the fibrous flexible zinc||zinc symmetric battery prepared in Example 1 (zinc utilization rate 85.4%) is shown. Figure 3 As can be seen, the fibrous flexible zinc||zinc symmetric cell can stably cycle for 300 hours. The zinc utilization rate is calculated as follows:

[0152] The capacity density is 37.5 mAh / cm³. 2 (Actual measured bulk density per unit area), the surface area of ​​the zinc wire is π × 0.03 cm (diameter) × 1 cm (length), and the volume of the zinc wire is π × (0.03 cm / 2). 2 ×1cm (length), theoretical zinc capacity is 820mAh / g, zinc density is 7.14 g / cm³ 3 The calculation formula is: Zinc utilization rate = (37.5 × surface area) / (volume × theoretical capacity × density).

[0153] Figure 4 The cycling performance curve of the fibrous flexible zinc-ion full cell prepared in Example 1 (N / P ratio of 2.55, current density of 2 A g) is shown. -1 ).from Figure 4 The results show that the flexible zinc-ion full cell retains 92.31% of its capacity after 1500 cycles, with an average coulombic efficiency of 99.94%, demonstrating its ultra-long cycle life under high zinc utilization. The N / P ratio refers to the negative electrode discharge capacity / positive electrode discharge capacity; the positive electrode discharge specific capacity is 180.73 mAh / g (from...). Figure 4 The first direct readout during the mid-cycle showed that the mass of the positive electrode active material was 16.86 μg / cm (i.e., 16.86 μg of polyaniline per cm of carbon fiber in Example 1), and the positive electrode discharge capacity was 180.73 × 16.86 × 10⁻⁶.-6 =3.05×10 -3 The negative electrode discharge capacity was calculated as follows: In Example 1, the mass of zinc electroplated on the carbon fiber was 9.49 μg, the theoretical capacity of zinc was 820 mAh / g, and the zinc negative electrode capacity was 9.49 × 10⁻⁶ mAh / g. -6 ×820=7.78×10 -3 mAh.

[0154] Figure 5 The charge-discharge curves of the fibrous flexible zinc-ion full cell prepared in Example 1 before and after 3000 continuous bending at 180° (current density during testing was 0.2 A g) are shown. -1 ).from Figure 5 The results show that after 3000 bending cycles, the discharge specific capacity of the flexible zinc-ion full cell can still be maintained at 99.9% of that before bending, proving that it has excellent flexibility and interface stability.

[0155] Figure 6 The fibrous flexible zinc-ion full cell prepared in Example 1 (i.e. Figure 6 A photo shows a medium-fiber zinc battery woven into a wristband to power a wearable LED light strip. Figure 6 As can be seen, flexible zinc-ion full batteries are easy to weave, which can meet the development requirements of wearable devices.

[0156] It is understood that the technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0157] The above are merely preferred embodiments of this application, and only specifically describe the technical principles of this application. These descriptions are only for explaining the principles of this application and should not be construed as limiting the scope of protection of this application in any way. Based on this explanation, any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application, as well as other specific embodiments of this application that can be conceived by those skilled in the art without creative effort, should be included within the scope of protection of this application.

Claims

1. A method for preparing a fibrous flexible aqueous zinc battery, characterized in that, Includes the following steps: Prepare hydrogel electrolyte precursor solution; The positive and negative electrodes are placed in the hydrogel electrolyte precursor solution, and an electric current is applied to the hydrogel electrolyte precursor solution to form hydrogel electrolyte on the surface of the positive and negative electrodes. The hydrogel electrolyte is then immersed in a zinc salt solution; The hydrogel electrolyte precursor solution includes sodium alginate, attapulgite, acrylamide, N,N'-methylenebisacrylamide, persulfate, and water.

2. The method for preparing a fibrous flexible aqueous zinc battery as described in claim 1, characterized in that, The positive and negative electrodes are placed in the hydrogel electrolyte precursor solution, and the counter electrode is also placed in the hydrogel electrolyte precursor solution. Both the positive and negative electrodes are used as working electrodes and connected to the positive terminal of the power supply. The counter electrode is connected to the negative terminal of the power supply. A constant current of 1~20mA is applied to the working electrode and the counter electrode for 10~600s to prepare the hydrogel electrolyte on the surface of the positive and negative electrodes.

3. The method for preparing a fibrous flexible aqueous zinc battery as described in claim 1, characterized in that, The hydrogel electrolyte precursor solution contains sodium alginate at a concentration of 1-200 mg / mL, attapulgite at a concentration of 1-400 mg / mL, acrylamide at a concentration of 1-100 mg / mL, N,N'-methylenebisacrylamide at a concentration of 0.01-1 mg / mL, and persulfate at a concentration of 0.05-10 mg / mL. The persulfate includes at least one of potassium persulfate and ammonium persulfate.

4. The method for preparing a fibrous flexible aqueous zinc battery as described in claim 1, characterized in that, The positive electrode comprises carbon fiber and polyaniline located on the surface of the carbon fiber; The method for preparing the positive electrode includes the following steps: Aniline monomer is mixed with hydrochloric acid solution to obtain aniline monomer solution; Carbon fibers are immersed in an aniline monomer solution, and then persulfate is added to the aniline monomer solution. The immersion continues to form polyaniline on the surface of the carbon fibers.

5. The method for preparing the fibrous flexible aqueous zinc battery as described in claim 4, characterized in that, The concentration of the hydrochloric acid solution is 0.5~2 mol / L; The volume ratio of the aniline monomer to the hydrochloric acid solution is 1:(10~200); The molar ratio of persulfate to hydrochloric acid is 1:(2~10), and the persulfate includes at least one of potassium persulfate and ammonium persulfate; The diameter of the carbon fiber is 0.05 ~ 0.3 mm.

6. The method for preparing a fibrous flexible aqueous zinc battery as described in claim 4, characterized in that, In the step of immersing carbon fibers in an aniline monomer solution, the immersion temperature is 0~5℃ and the immersion time is 0.1~3h. In the step of adding persulfate to the aniline monomer solution and continuing the soaking, the soaking temperature is 0~5℃ and the soaking time is 0.1~3h.

7. The method for preparing a fibrous flexible aqueous zinc battery as described in claim 1, characterized in that, The step of immersing the hydrogel electrolyte in the zinc salt solution is to soak for 1 to 60 minutes. The zinc salt in the zinc salt solution includes at least one of zinc sulfate, zinc trifluoromethanesulfonate, zinc nitrate, zinc chloride, and zinc acetate; The concentration of the zinc salt solution is 0.1~5 mol / L.

8. The method for preparing a fibrous flexible aqueous zinc battery as described in claim 1, characterized in that, The negative electrode is a zinc wire, and the diameter of the zinc wire is 0.1~2 mm; Alternatively, the negative electrode comprises carbon fibers and a zinc plating layer on the surface of the carbon fibers, and the method for preparing the negative electrode includes the following steps: Carbon fiber is placed in a Zn electroplating solution with a concentration of 0.1~2 mol / L and an anode is placed in the Zn electroplating solution. The carbon fiber is used as the cathode and connected to the negative terminal of the power supply, and the anode is connected to the positive terminal of the power supply. Electroplating is performed to form a zinc coating on the surface of the carbon fiber. The electroplating current is 0.1~1 mA, the electroplating time is 5~60 s, and the anode is zinc wire or zinc foil.

9. A fibrous flexible aqueous zinc battery, characterized in that, It is prepared by any one of the preparation methods described in claims 1 to 8.

10. The application of a fibrous flexible aqueous zinc battery prepared by any one of the preparation methods described in claims 1 to 8, or the fibrous flexible aqueous zinc battery described in claim 9, in wearable electronic devices.

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