Aerogel-based modified fabric water turbine and preparation method and application thereof

Abstract

This invention discloses a hydroelectric generator based on aerogel-modified fabric, its preparation method, and its applications. By synergistically constructing an MXene conductive network and a three-dimensional interconnected framework structure of sodium carboxymethyl cellulose aerogel on the surface of the fabric fibers, the stability of interfacial ion transport and current output are improved, enabling the device to achieve continuous output for extended periods even after encapsulation in waterproof fabric. Simultaneously, the device exhibits an electrical signal response to changes in electrolyte concentration, allowing for the monitoring and indication of electrolyte concentration variations. Compared with existing technologies, this invention offers advantages such as superior electrical output performance, improved mechanical properties, scalable power supply, and concentration monitoring and indication capabilities.

Description

Technical Field

[0001] This invention relates to the field of flexible wearable energy device technology, and in particular to a hydrovoltaic generator based on aerogel-modified fabric, its preparation method, and its application. Background Technology

[0002] Hydrovoltaic generation is a technology that uses liquid water, sweat, or salt solutions to generate electrical signals and harvest energy through wetting, migration, and evaporation processes in porous / fiber materials. It has advantages such as good material flexibility and the ability to be integrated with fabrics, making it suitable for wearable and flexible electronic power supply.

[0003] Existing water-based photovoltaic devices typically rely on an interfacial ion-rich layer formed by the interaction of charged surfaces / functional groups with water. Driven by capillary water absorption and evaporation, ions migrate in a directional manner, thereby creating a potential difference across the device and outputting current. However, due to the difficulty in simultaneously managing the stability of the moisture gradient, pore structure, and interfacial ion transport, current technologies generally suffer from problems such as low current output, limited duration, strong dependence on the liquid environment, and output attenuation after packaging.

[0004] The existing technologies mainly include (but are not limited to) the following disclosed solutions: Patent application CN117937983A discloses a fabric-based hydroelectric generator device and its fabrication method based on a three-dimensional structure. The device achieves output by weaving fabric strips into a three-dimensional metal frame and partially immersing them in a salt solution. The device structure includes a three-dimensional metal frame and fabric strips woven onto the three-dimensional metal frame. In use, one or more of the woven three-dimensional metal frames are connected in series with their openings facing upwards, and partially immersed in the salt solution, thus creating working conditions between the liquid-immersed end and the air-exposed end, and outputting an electrical signal. However, this solution requires a metal frame for three-dimensional support and fixation, and relies on an external salt solution environment to maintain its operating state.

[0005] Patent application CN113395010A discloses a water-voltaic generator with enhanced salt solution performance, its preparation method and application, which establishes a concentration difference output through the hydrophilic region, hydrophobic region and the state of immersion / exposure of the liquid surface of the thin film.

[0006] Patent application CN120855934A discloses a wood-based evaporation-driven hydrovoltaic power generation device and its preparation method, achieving output through wood matrix modification and evaporation-driven generation. However, the main drawbacks of the above-mentioned prior art solutions are as follows: (1) The device structure is relatively complex: it relies on a three-dimensional metal frame or support structure, and it is not easy to make it into a thin, soft, and wearable fabric. (2) The usage depends on the liquid environment: the device needs to be partially immersed in the salt solution or kept in the liquid state, which usually requires the container / liquid conditions to match, making it inconvenient to move and use in daily life; (3) Current output and continuous operation are limited: fluctuations in open evaporation and liquid supply conditions will cause output attenuation, and changes in evaporation / liquid supply status after encapsulation can further affect continuous output. (4) Insufficient compatibility with packaging: Existing solutions often fail to simultaneously ensure moisture transport and evaporation maintenance after protective packaging, thus affecting long-term stable operation.

[0007] Therefore, there is a need for a modified fabric and device solution that can achieve stable three-dimensional interconnected channels on fabrics, while also providing high current output and long-term encapsulation operation. Summary of the Invention

[0008] This invention aims to overcome the problems of low current output, short continuous power generation time, and easy output decay after encapsulation that are common in existing hydro-voltaic power generation devices. It provides a hydro-voltaic generator based on aerogel-modified fabric, its preparation method, and its applications. This invention enhances the aerogel reinforcement structure of the fabric and improves the interfacial ion transport stability by synergistically constructing an MXene conductive network and a three-dimensional interconnected framework structure of sodium carboxymethyl cellulose aerogel on the surface of the fabric fibers, thereby increasing the current output. Simultaneously, the device can still achieve long-term continuous output after being encapsulated in waterproof fabric. Furthermore, the device has an electrical signal response to changes in electrolyte concentration, which can be used for monitoring and indicating changes in electrolyte concentration.

[0009] To achieve the above objectives, this invention provides a method for preparing a hydroelectric generator based on aerogel-modified fabric. The core of this method lies in: using MXene, sodium carboxymethyl cellulose, and silver nitrate to form a composite structure on the surface of fabric fibers, and then constructing a three-dimensionally interconnected aerogel reinforcement layer between the fibers through gelation and freeze-drying, thereby obtaining the aerogel-modified fabric and assembling the hydroelectric generator.

[0010] The preparation method includes the following steps: (1) The fabric substrate was immersed in MXene dispersion and dried to obtain MXene modified fabric; (2) The MXene-modified fabric is immersed in a sodium carboxymethyl cellulose solution, and after removal, a sodium carboxymethyl cellulose-impregnated fabric is obtained; (3) The sodium carboxymethyl cellulose impregnated fabric is impregnated in silver nitrate solution and gelled at room temperature to obtain gelled fabric; (4) The gelled fabric is subjected to liquid nitrogen freezing and freeze-drying to obtain an aerogel-modified fabric; (5) Cut the aerogel-modified fabric, and connect the first electrode and the second electrode to both sides of the cut aerogel-modified fabric to prepare the hydrovolt generator based on the aerogel-modified fabric.

[0011] In some embodiments, after the hydroelectric generator is prepared, its upper and lower surfaces can be encapsulated with waterproof fabric to obtain an encapsulated hydroelectric generator, thereby improving the stability of the device during actual use.

[0012] Furthermore, the waterproof fabric is selected from one or more of the following materials: TPU film composite fabric, ePTFE film composite fabric, PU film composite fabric, PU coated fabric, silicone coated fabric, acrylic coated fabric, PVC coated fabric or waterproof nonwoven composite material.

[0013] Furthermore, the preparation method satisfies one or more of the following conditions: (1) The preparation of the MXene dispersion includes: adding MXene to water and dispersing it by ultrasonication to obtain the MXene dispersion; the concentration of the MXene dispersion is 1 to 20 mg / mL; the ultrasonic dispersion time is 10 to 60 min.

[0014] Furthermore, the MXene is a two-dimensional transition metal carbide, nitride, or carbonitride material with the general formula M. n+ 1X n T x The MXene is selected from Ti3C2T x Ti2CT x Nb2CT x V2CT x Mo2CT x Ta4C3T x One or more of them.

[0015] (2) The preparation of the sodium carboxymethyl cellulose solution includes: adding sodium carboxymethyl cellulose to water and stirring to dissolve it, thereby obtaining a sodium carboxymethyl cellulose solution; the concentration of the sodium carboxymethyl cellulose solution is 5 to 30 mg / mL; and stirring at 40 to 80°C for 0.5 to 3 h to promote dissolution.

[0016] (3) The preparation of the silver nitrate solution includes: adding silver nitrate to water and ultrasonically mixing to obtain a silver nitrate solution; the concentration of the silver nitrate solution is 20-150 mg / mL; the ultrasonic mixing time is 5-30 min.

[0017] (4) The mass concentration ratio of the MXene dispersion, sodium carboxymethyl cellulose solution and silver nitrate solution is 1:(1.25-3.0):(10-20) in mg / mL.

[0018] (5) The fabric base is one or more of polyester fabric and polyester-cotton fabric; the length of the fabric base is 1 cm to 10 cm and the width is 1 cm to 10 cm.

[0019] (6) During the MXene impregnation and drying process, the impregnation time is 0.5 to 6 h and the drying temperature is 30 to 60 ℃; during the sodium carboxymethyl cellulose impregnation process, the impregnation time is 0.5 to 6 h; during the silver nitrate impregnation and room temperature gelation process, the impregnation time is 5 to 60 min and the gelation time is 0.5 to 6 h; the liquid nitrogen freezing time is 12 to 72 h; the freeze drying is carried out using a freeze dryer at a temperature of -50 ℃ to -10 ℃ for 6 to 24 h.

[0020] (7) When used for device assembly, the aerogel-modified fabric is cut into fabric pieces with a length of 1 cm to 5 cm and a width of 1 cm to 5 cm; the first electrode and the second electrode are respectively connected to both sides of the cut fabric pieces. The first electrode and the second electrode are both conductive electrodes, and the conductive electrodes are one or more of copper sheets, metal foils, stainless steel electrodes, carbon cloth electrodes or inert metal electrodes.

[0021] The present invention also provides a water-volt generator based on the above-described preparation method. The water-volt generator includes an aerogel-modified fabric, a first electrode, and a second electrode, wherein the first electrode and the second electrode are respectively connected to both sides of the aerogel-modified fabric. In some embodiments, it further includes a waterproof fabric encapsulated on the upper and lower surfaces of the water-volt generator. The aerogel-modified fabric is a three-dimensional interconnected framework structure of MXene conductive network and sodium carboxymethyl cellulose aerogel synergistically constructed on the surface of fabric fibers.

[0022] The present invention also provides applications of the aforementioned water-volt generator: the water-volt generator is used for powering wearable and flexible electronics, or for monitoring and indicating changes in electrolyte concentration.

[0023] The present invention also provides a packaged hydroelectric generator, which is obtained by packaging the upper and lower surfaces of the hydroelectric generator with waterproof fabric after the hydroelectric generator has been prepared.

[0024] Compared with the prior art, the present invention has at least the following advantages and beneficial effects: (1) The present invention constructs a three-dimensional interconnected skeleton structure of MXene conductive network and sodium carboxymethyl cellulose aerogel on the surface of fabric fibers, thereby enabling the modified fabric to form a stable composite interface and continuous ion transport channel, thereby improving the stability of interface ion transport and enhancing electrical output capability.

[0025] (2) The hydroelectric generator based on aerogel modified fabric prepared by the present invention can generate stable electrical output in both liquid water and salt water systems; after further encapsulation with waterproof fabric, the device can still maintain continuous working capability, which is beneficial to improving the stability and reliability in actual use.

[0026] (3) The aerogel three-dimensional interconnected structure formed by the present invention can cross the fiber gap and reinforce the fabric, thereby improving the mechanical stability and service tolerance of the modified fabric and enhancing the structural stability under bending and other working conditions.

[0027] (4) The device of the present invention (hydrovoltaic generator based on aerogel modified fabric and encapsulated hydrovoltaic generator) has good scalability and can expand the output through series or parallel connection, thereby adapting to different voltage or current requirements and can be used for power supply scenarios of low power electronic devices.

[0028] (5) The device of the present invention (a hydroelectric generator based on aerogel modified fabric and a packaged hydroelectric generator) has an electrical signal response to changes in electrolyte concentration, and can be used to monitor and indicate changes in electrolyte concentration (salinity changes), thus expanding the functionality of the device in wearable and flexible electronic applications. Attached Figure Description

[0029] Figure 1 This is a SEM image of the aerogel-modified fabric prepared in Example 1 of the present invention. It is used to characterize the successful growth of a three-dimensional interconnected network / honeycomb aerogel framework structure spanning the fiber gaps on the surface of the modified fabric fibers. Figure 2 The tensile-tensile properties test diagrams are shown for the blank fabric, MXene-modified fabric, and aerogel-modified fabric prepared in Example 1 of this invention. Figure 3 This is a schematic diagram of a hydrovolt generator based on aerogel-modified fabric. Figure 4 This is a schematic curve showing the change of open-circuit voltage over time of the hydrovolt generator based on aerogel-modified fabric prepared in Example 1 of the present invention under deionized water conditions; Figure 5 The diagram shows the short-circuit current versus time curve of the hydrovolt generator based on aerogel-modified fabric prepared in Example 1 of this invention under deionized water conditions. Figure 6 This is a schematic curve showing the change of open-circuit voltage over time of the hydrovolt generator based on aerogel-modified fabric prepared in Example 1 of the present invention under artificial sweat conditions; Figure 7 This is a schematic curve showing the change of short-circuit current over time of a hydrovolt generator based on aerogel-modified fabric prepared in Example 1 of the present invention under artificial sweat conditions; Figure 8The diagram shows the change of open-circuit voltage over time of the hydro-volt generator based on aerogel-modified fabric prepared in Example 1 of the present invention when it is encapsulated under artificial sweat conditions (i.e., encapsulated hydro-volt generator). Figure 9 The diagram shows the change of short-circuit current over time of the hydro-volt generator based on aerogel modified fabric prepared in Example 1 of the present invention when it is encapsulated under artificial sweat conditions (i.e., encapsulated hydro-volt generator). Figure 10 The output voltage test diagram of the water-volt generator based on aerogel-modified fabric prepared in Example 1 of the present invention after being connected in series; Figure 11 The output current test diagram of the hydrovolt generator based on aerogel modified fabric prepared in Example 1 of the present invention after parallel connection; Figure 12 The output voltage and current of the hydrovoltaic generator based on aerogel-modified fabric prepared in Example 1 of the present invention under different concentrations of NaCl solution conditions; Figure 13 A photograph showing two encapsulated hydrovolt generators prepared in Embodiment 1 of the present invention lighting up a watch under the influence of artificial sweat; Figure 14 The photo shows three hydroelectric generators based on aerogel-modified fabrics prepared in Example 1 of the present invention illuminating a thermometer and hygrometer under the drive of artificial sweat. Detailed Implementation

[0030] The present invention will now be described in detail with reference to specific embodiments. These embodiments are for illustrative purposes only and are not intended to limit the scope of protection of the present invention. Component models, material names, connection structures, control methods, and other features not explicitly described in this technical solution are considered common technical features disclosed in the prior art. The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] It should be noted that the technical terms used in this invention are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of this invention. Unless otherwise specified, all raw materials, reagents, instruments and equipment used in the following embodiments of this invention can be purchased from the market or prepared by existing methods.

[0032] In the examples below, unless otherwise specified, the reagents used are commercially available products and the methods employed are those known in the art.

[0033] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Before further describing the specific embodiments of the present invention, it should be understood that the scope of protection of the present invention is not limited to the specific embodiments described below; the terminology used in the embodiments of the present invention is for describing specific embodiments and not for limiting the scope of protection of the present invention. Test methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions or according to the conditions recommended by the respective manufacturers.

[0034] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise stated in the present invention, both endpoints of each numerical range and any value between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art. In addition to the specific methods, apparatus, and materials used in the embodiments, based on the knowledge of the prior art possessed by one of ordinary skill in the art and the description of this invention, any prior art methods, apparatus, and materials similar to or equivalent to those described, apparatus, and materials in the embodiments of this invention may be used to implement the present invention.

[0035] Example 1 This embodiment provides a method for preparing a hydroelectric generator based on aerogel-modified fabric, including the following steps: (1) Cut the fabric base (polyester fabric) to 6 cm × 6 cm to obtain blank fabric.

[0036] (2) Prepare MXene dispersion by mixing Mxene (Ti3C2T) x (CAS No.: 12363-89-2, commercially available) was added to deionized water and ultrasonically dispersed to obtain an MXene dispersion with a concentration of 8 mg / mL. The dispersion was ultrasonically dispersed for 30 min until homogeneous.

[0037] (3) The blank fabric was immersed in the MXene dispersion for 2 h, then removed and dried; it was rinsed with deionized water to remove any unbonded MXene on the surface, and dried again to obtain the MXene-modified fabric. Both drying processes were carried out in a constant temperature oven at 45 °C.

[0038] (4) Prepare a sodium carboxymethyl cellulose solution by adding sodium carboxymethyl cellulose to deionized water and stirring to dissolve it. The concentration of sodium carboxymethyl cellulose in the sodium carboxymethyl cellulose solution is 15 mg / mL. The specific conditions are stirring for 1 h in a 60 ℃ water bath until dissolved.

[0039] (5) The MXene-modified fabric was immersed in sodium carboxymethyl cellulose solution for 2 h to obtain sodium carboxymethyl cellulose impregnated fabric.

[0040] (6) Prepare silver nitrate solution by adding silver nitrate to deionized water and ultrasonically mixing to obtain silver nitrate solution. The concentration of silver nitrate in the silver nitrate solution is 100 mg / mL and the ultrasonic mixing time is 10 min. The sodium carboxymethyl cellulose impregnated fabric obtained in step (5) is immersed in silver nitrate solution for 30 min and then taken out and allowed to stand at room temperature for 2 h to form glue to obtain glued fabric.

[0041] (7) The aerogel-modified fabric was frozen in liquid nitrogen for 48 h; then it was freeze-dried in a freeze dryer (cold trap temperature -40℃) for 12 h to obtain the aerogel-modified fabric.

[0042] (8) Cut a 3 cm × 2 cm fabric piece from the 6 cm × 6 cm aerogel modified fabric obtained in step (7) for device assembly; connect the two ends of the fabric piece to the first electrode and the second electrode respectively through wires to obtain a hydrovolt generator (HEG), that is, a hydrovolt generator based on aerogel modified fabric; the electrode is a copper sheet.

[0043] (9) The upper and lower surfaces of the HEG are encapsulated using a TPU film composite fabric (purchased from Covestro (Bayer) in Germany) to obtain an encapsulated hydroelectric generator. In this embodiment, the thickness of the TPU film composite fabric is approximately 0.20 mm. During encapsulation, the TPU film composite fabric is covered on the upper and lower surfaces of the HEG respectively, and the edges are sealed by hot-melt adhesive film hot-pressing to achieve a four-sided seal (the sealing width is approximately 2-4 mm). At the same time, electrode lead-out positions are reserved at the sealing edges so that the electrodes can be led out from the sealing edges.

[0044] The following tests were performed on the hydro-voltaic generator (HEG) prepared in Example 1: Figure 1 The image shown is a SEM image of the aerogel-modified fabric prepared according to this invention. The aerogel-modified fabric sample was adhered to the sample stage using conductive adhesive and then subjected to gold sputtering. The morphology of the sample was then observed. Figure 1 As shown, aerogel-modified fabric fibers have successfully grown three-dimensional interconnected network and honeycomb aerogel framework structures spanning the fiber gaps.

[0045] Figure 2 The figure shows the tensile-tensile properties of the blank fabric, MXene-modified fabric, and aerogel-modified fabric prepared in this invention. Figure 2As shown, the breaking strength and elongation at break of the blank fabric are 14.9 MPa and 16.38%, respectively. Its load-bearing capacity mainly comes from the intrinsic strength of the fibers and limited inter-fiber interactions. Therefore, it breaks under relatively small deformations, exhibiting a relatively brittle fracture characteristic. The breaking strength of the MXene-modified fabric is increased to 18.1 MPa, and the elongation at break is increased to 24.1%. This is due to the enhanced interfacial interaction between MXene and fibers, and the formation of lamellar connections between fibers, which improves the load transfer efficiency of the fabric and correspondingly increases its overall toughness. The tensile strength of aerogel-modified fabrics (aerogel-modified fabrics) is increased to 26.03 MPa, and the elongation at break reaches 36.1%. This is attributed to its unique multi-level energy dissipation mechanism: during the stretching process, the collapse of the pores of the aerogel network, the rearrangement of nanofibers, and the progressive fracture together constitute an efficient energy dissipation system. This unique structural evolution mechanism enables aerogel-modified fabrics to achieve the highest strength, amazing extensibility, and optimal toughness at the final fracture, giving aerogel-modified fabrics both the softness required for wearing and the durability required for use.

[0046] Figure 3 The image shows a schematic diagram of the hydroelectric generator structure based on aerogel-modified fabric prepared according to the present invention. Figure 3 As shown, taking a copper electrode as an example, 0.2 mL of deionized water or solution (such as electrolyte solution or artificial sweat) is dropped onto the left end of the fabric to create a water content gradient.

[0047] The power generation performance of the hydroelectric generator based on aerogel-modified fabric prepared in step (8) of Example 1 was tested using a Keithley 2450 digital source meter, and its output voltage and current values ​​were read. See the results below. Figures 4 to 7 .

[0048] like Figure 4 As shown, adding 0.2 mL of deionized water can generate an open-circuit voltage of about 0.26 V, which is maintained for about 7000 s.

[0049] like Figure 5 As shown, adding 0.2 mL of deionized water can generate a short-circuit current of about 126 μA, with a continuous output time of about 7000 s.

[0050] like Figure 6 and Figure 7 As shown, adding 0.2 mL of artificial sweat (pH=7.4) can generate an open-circuit voltage of about 0.5 V and a short-circuit current of up to about 360 μA, with a continuous output time of about 8000 s.

[0051] The packaged hydro-voltaic generator prepared in step (9) was tested using a Keithley 2450 digital source meter. The results are shown in [link to results]. Figures 8 to 9.

[0052] like Figures 8 to 9 As shown, adding 0.2 mL of artificial sweat (pH=7.4) to the left end of the encapsulated water-voltaic power generation device can generate a maximum output voltage of about 0.52 V and a maximum output current of about 350 μA, with a continuous output time of about 7 h.

[0053] like Figure 10 As shown, the output voltage of a hydro-volt generator (HEG) can be increased by connecting them in series: the output voltages of 2, 3, 4, and 5 devices connected in series can reach 0.51 V, 0.76 V, 0.99 V, and 1.25 V, respectively.

[0054] like Figure 11 As shown, the output current of a hydro-voltaic generator (HEG) can be increased by connecting them in parallel: the output currents of 2, 3, 4, and 5 devices connected in parallel can reach 214 μA, 357 μA, 457 μA, and 598 μA, respectively.

[0055] like Figure 12 As shown, using NaCl solution as a representative electrolyte, changing its concentration and applying it to a hydroelectric generator (HEG) reveals a clear response between the HEG's output voltage and current and the electrolyte concentration: as the NaCl solution concentration gradually decreases, the device's electrical output (voltage / current) generally shows a downward trend. Based on this concentration-dependent output change pattern, the hydroelectric generator can be used for auxiliary monitoring of electrolyte concentration changes (salinity changes).

[0056] like Figure 13 and Figure 14 As shown, multiple hydro-generators (HEGs) or multiple encapsulated hydro-generators can light up a watch or thermometer driven by artificial sweat, demonstrating the wearability and potential of hydro-generators (HEGs) and encapsulated hydro-generators for practical applications.

[0057] Examples 2-12 and Comparative Examples 1-4 Based on Example 1, a single condition was changed while keeping the other parameters the same. The specific changes are shown in Table 1.

[0058] Table 1. Changes in conditions for different embodiments / comparative examples. The power generation performance of the device prepared above was tested using a Keithley 2450 digital source meter. The output voltage and current of the material are shown in Table 2.

[0059] Table 2 Output open-circuit voltage and short-circuit current for different embodiments / comparative examples. Results Analysis and Conclusions: (1) The comparison of Examples 1 to 6 shows that as the concentration of MXene dispersion increases from 5 mg / mL to 8 mg / mL, the output voltage and current of the device generally show an increasing trend; when it is further increased to 9 to 10 mg / mL, the output decreases, which is presumably related to the aggregation caused by excessive MXene, the reduction of effective interface and the obstruction of ion transport channels.

[0060] (2) The comparison between Example 1 and Examples 7-8 shows that when the concentration of sodium carboxymethyl cellulose solution is too low, it is not easy to form a stable three-dimensional aerogel network, resulting in insufficient ion transport and water layer stability, thus reducing output; when the concentration is too high, it may over-coat MXene and make the structure more compact, thus reducing output.

[0061] (3) The comparison between Example 1 and Examples 9-12 shows that, under the condition of the same liquid volume, the fabric size (fabric length and width) will affect the establishment and maintenance of the moisture gradient between the wet end and the dry end, thereby affecting the output performance.

[0062] (4) The comparison between Example 1 and Comparative Example 1 shows that only the MXene modified fabric lacks the hierarchical pore structure reinforced by aerogel, resulting in insufficient ion transport and aquifer stability, and low output.

[0063] (5) The comparison between Example 1 and Comparative Example 2 shows that when the drying process is used instead of freeze drying, the gel network is prone to collapse and it is difficult to form a stable porous structure, resulting in a significant reduction in output. This indicates that freeze drying plays an important role in preserving the aerogel pore structure and improving water output.

[0064] (6) Comparison of Example 1 with Comparative Examples 3 and 4 shows that neither Comparative Example 3 nor Comparative Example 4 formed a three-dimensional interconnected aerogel structure, and the electrical output of the devices was very low. The comparative results indicate that the introduction of the MXene conductive network and its combination with sodium carboxymethyl cellulose / silver nitrate gelation and freeze-drying to form an aerogel structure is the key to obtaining a higher electrical output.

[0065] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Anyone skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the invention should still be covered by the claims of the invention. The above description of the embodiments is to facilitate understanding and use of the invention by those skilled in the art. Those skilled in the art can obviously easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative effort. Therefore, the invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the invention without departing from the scope of the invention should be within the protection scope of the invention.

Claims

1. A method for preparing a hydroelectric generator based on aerogel-modified fabric, characterized in that, The preparation method includes the following steps: (1) The fabric substrate was immersed in MXene dispersion and dried to obtain MXene modified fabric; (2) The MXene-modified fabric is immersed in a sodium carboxymethyl cellulose solution, and after removal, a sodium carboxymethyl cellulose-impregnated fabric is obtained; (3) The sodium carboxymethyl cellulose impregnated fabric is impregnated in silver nitrate solution and gelled at room temperature to obtain gelled fabric; (4) The gelled fabric is subjected to liquid nitrogen freezing and freeze-drying to obtain an aerogel-modified fabric; (5) Cut the aerogel-modified fabric, and connect the first electrode and the second electrode to both sides of the cut aerogel-modified fabric to prepare the hydrovolt generator based on the aerogel-modified fabric.

2. The preparation method according to claim 1, characterized in that, After the aerogel-modified fabric-based hydrovolt generator is prepared, the upper and lower surfaces of the aerogel-modified fabric-based hydrovolt generator are encapsulated with waterproof fabric to obtain an encapsulated hydrovolt generator.

3. The preparation method according to claim 2, characterized in that, The waterproof fabric is selected from one or more of the following materials: TPU film composite fabric, ePTFE film composite fabric, PU film composite fabric, PU coated fabric, silicone coated fabric, acrylic coated fabric, PVC coated fabric or waterproof non-woven composite material.

4. The preparation method according to claim 1, characterized in that, The MXene is a two-dimensional transition metal carbide, nitride, or carbonitride material with the general formula M. n+1 X n T x The MXene is selected from Ti3C2T x Ti2CT x Nb2CT x V2CT x Mo2CT x Ta4C3T x One or more of them.

5. The preparation method according to claim 1, characterized in that, The preparation process of the MXene dispersion includes the following steps: adding MXene to water and dispersing and mixing it by ultrasonication to obtain the MXene dispersion; The concentration of the MXene dispersion is 1–20 mg / mL; During the preparation of the MXene dispersion, the ultrasonic dispersion time is 10–60 min; The preparation process of the sodium carboxymethyl cellulose solution includes the following steps: adding sodium carboxymethyl cellulose to water and stirring to dissolve it, thereby obtaining a sodium carboxymethyl cellulose solution; The concentration of the sodium carboxymethyl cellulose solution is 5–30 mg / mL; During the preparation of the sodium carboxymethyl cellulose solution, stirring is performed at 40–80 °C for 0.5–3 h to promote dissolution; The preparation process of the silver nitrate solution includes the following steps: adding silver nitrate to water and ultrasonically mixing to obtain a silver nitrate solution; The concentration of the silver nitrate solution is 20–150 mg / mL; During the preparation of the silver nitrate solution, the ultrasonic mixing time is 5–30 min.

6. The preparation method according to claim 1, characterized in that, The mass concentration ratio of the MXene dispersion, sodium carboxymethyl cellulose solution, and silver nitrate solution, calculated in mg / mL, is 1:(1.25–3.0):(10–20). The fabric base is one or more of polyester fabric and polyester-cotton fabric; The fabric substrate has a length of 1 cm to 10 cm and a width of 1 cm to 10 cm.

7. The preparation method according to claim 1, characterized in that, The fabric substrate was immersed in MXene dispersion and dried for 0.5–6 h at a drying temperature of 30–60 °C. The MXene-modified fabric was immersed in a sodium carboxymethyl cellulose solution for 0.5–6 hours. During the process of immersing the sodium carboxymethyl cellulose-impregnated fabric in silver nitrate solution and forming a gel at room temperature, the immersion time is 5–60 min and the gel forming time is 0.5–6 h. The liquid nitrogen freezing process involves freezing the object in liquid nitrogen for 12–72 hours. The freeze-drying process involves using a freeze dryer to freeze-dry the food at a temperature of -50°C to -10°C for 6 to 24 hours.

8. The preparation method according to claim 1, characterized in that, When used for device assembly, the aerogel-modified fabric is cut into fabric pieces with a length of 1 cm to 5 cm and a width of 1 cm to 5 cm. Both the first electrode and the second electrode are conductive electrodes, and the conductive electrodes are one or more of the following: copper sheet, metal foil, stainless steel electrode, carbon cloth electrode, or inert metal electrode.

9. A hydroelectric generator, characterized in that, The hydroelectric generator is obtained by the preparation method described in any one of claims 1 to 8.

10. An application of the hydroelectric generator as described in claim 9, characterized in that, The hydroelectric generator is used for powering wearable and flexible electronics or for monitoring and indicating changes in electrolyte concentration.

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