Moisture power generation device and preparation method thereof

Abstract

The invention discloses a moisture power generation device and a preparation method thereof. The invention discloses a preparation method of a moisture power generation device. The preparation method comprises the following steps: (1) preparing polypyrrole modified dust-free paper; (2) sequentially placing the polypyrrole modified dust-free paper, a sodium alginate / graphene oxide mixed solution and the polypyrrole modified dust-free paper in a directional freeze-drying device, freezing with liquid nitrogen, and then freeze-drying; and (3) soaking the freeze-dried product in a CaCl2 solution, pressing the product into a sheet, soaking the sheet in a LiCl solution, and blow-drying the sheet to obtain the moisture power generation device. The prepared moisture power generation device has the advantages of being good in structural stability and excellent in moisture power generation performance, and meanwhile the preparation method is simple and low in cost.

Description

Technical Field

[0001] The present invention relates to moisture power generation, and particularly to a moisture power generation device and a preparation method thereof, belonging to the technical field of functional materials. Background Art

[0002] The development of human society has been accompanied by the continuous development and utilization of energy. From coal to oil and natural gas, non-renewable fossil energy has always been the main energy source globally. The large-scale use of fossil energy has brought many conveniences to human production and life. However, its non-renewable nature has caused an energy crisis, and the resulting global warming continues to threaten the earth's ecological environment.

[0003] Water, as a natural resource widely distributed and rich in reserves on the earth, covers about 71% of the earth's surface, approximately 13000 trillion liters, and is the largest energy carrier on the earth. The state of water is variable. From the perspective of energy conversion, flowing water is more likely to achieve the conversion of water energy into electrical energy. Flowing water on land usually exists in gaseous and liquid forms, including moisture, rain, clouds, lakes, rivers, and oceans. The history of human utilization of water energy is long. As early as 400 BC, the waterwheel invented by humans could convert the kinetic energy of water into mechanical energy through a water wheel. However, currently, the utilization of water energy by humans is only limited to converting the mechanical energy of flowing liquid water into electrical energy, such as hydropower and tidal power generation, ignoring the higher energy possessed by gaseous water and the potential to convert it into electrical energy. Moreover, hydropower has very strict requirements on environmental geographical locations. Therefore, developing new power generation technologies to obtain energy from gaseous water will be beneficial to the expansion of green energy and alleviate the energy crisis.

[0004] Among them, obtaining energy from moisture has significant advantages. Moisture is widely distributed and is almost not restricted by regions. In recent years, a large number of studies have utilized moisture adsorption-induced functional materials to generate electrical energy and applied it to the development of self-powered devices. Therefore, moisture electricity generators (MEGs) based on principles such as ion gradient diffusion and streaming potential have been proposed by researchers. Moisture electricity generators have successfully converted moisture energy into electrical energy and are a new type of green power generation device. However, currently, the development of moisture electricity generators is still in its initial stage, and many key problems have not been effectively solved. For example, most of the currently used functional materials are expensive, and the processing technology is complex and harsh. Due to being very sensitive to changes in environmental humidity, intermittent energy output occurs, and the conversion of moisture energy cannot be continuously achieved. Moreover, the open-circuit voltage and short-circuit current output of the device are not ideal. Especially for the output of short-circuit current, the current of most of the currently reported devices is still at the nanoampere (nA) level. Obviously, there are still bottleneck problems in the development of moisture power generation, such as low power generation performance, poor stability, and poor durability. There is an urgent need to develop new functional materials for highly efficient and highly stable moisture power generation.

[0005] Improved power generation performance can be achieved by microstructurally manipulating the active material to improve water transport within the material, functionalizing and / or compounding the active material to increase the functional group gradient, or introducing hygroscopic salts to improve water adsorption, thereby increasing the number of charge carriers. Furthermore, the MEG electrode, which collects current and controls the moisture gradient within the device, also has a significant impact on the power generation performance of the wet gas power generation device. Initially, the electrodes used in wet gas power generation devices were mostly inert, symmetrical electrodes. As research progressed, researchers discovered that asymmetric electrode configurations can improve carrier transport at the electrode-material interface, such as by employing an inert-active electrode configuration or creating an asymmetric structure with electrodes of different charges. Furthermore, creating and strengthening the humidity gradient by configuring upper and lower electrodes of different areas is also a common method for improving the power generation performance of wet gas devices. It is worth noting that wet gas power generation materials are typically hydrophilic, which results in the electrodes being frequently exposed to a humid environment. This inevitably leads to electrochemical corrosion of active metal electrodes, hindering the long-term recycling and large-scale use of wet gas power generation devices. Furthermore, wet gas power generation devices often use external fixation (e.g., clamps, hot melt adhesive, rubber rings, etc.) to secure the electrodes. This creates contact resistance between the electrode and the material, hindering carrier migration and reducing the power generated by the wet gas power generation device. Using hydrophilic, corrosion-resistant, and flexible electrode materials in wet gas power generation devices could alleviate these issues.

[0006] Chinese invention patent application CN116169898A discloses a wet gas power generation device comprising a first electrode, a matrix / carbonized polymer dot layer, and a second electrode. The matrix / carbonized polymer dot layer is disposed between the first and second electrodes, with the first and second electrodes having different coverage areas on the matrix / carbonized polymer dot layer. The matrix / carbonized polymer dot layer is obtained by dispersing a carbonized polymer dot solution into a planar substrate and drying it. In this wet gas power generation device, the matrix / carbonized polymer dot layer utilizes an active power-generating material with high hygroscopicity and high ionization capacity. Furthermore, a pairing of different active metal electrodes, including liquid metal (LM), is employed to enhance the device's power output. Based on carbonized polymer dots, this wet gas power generator can be integrated on a variety of substrates on a large scale, exhibits excellent flexibility, and provides efficient, all-weather self-generated power. However, the technology's long-term, stable power generation capability needs to be improved. Summary of the invention

[0007] The purpose of the present invention is to provide a wet gas power generation device and its preparation method that can maintain structural stability in water, achieve long-term stable power generation for 27 hours in an environment (~25°C, RH=~60%), and output open circuit voltage can reach 0.7V, with excellent wet gas power generation performance.

[0008] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0009] A preparation method of a moisture-powered electrical device, comprising the following steps:

[0010] (1) First, prepare polypyrrole-modified dust-free paper;

[0011] (2) Place the polypyrrole-modified dust-free paper, sodium alginate / graphene oxide mixed solution, and polypyrrole-modified dust-free paper in sequence in directional freeze-drying, freeze with liquid nitrogen, and then perform freeze-drying;

[0012] (3) Immerse the product after freeze-drying in a CaCl2 solution, press it into a thin sheet, immerse it in a LiCl solution, and blow dry to obtain a moisture-powered electrical device.

[0013] To further achieve the object of the present invention, preferably, the preparation method of the polypyrrole-modified dust-free paper is as follows: Immerse the dust-free paper in a mixed solution composed of deionized water and concentrated HCl, add pyrrole (Py), stir, and then add an FeCl3 solution, react at 4 - 8 °C for 12 - 24 h, wash, and dry to obtain polypyrrole-modified dust-free paper.

[0014] Preferably, the concentration of sodium alginate in the mixed solution is 0.6 - 1.3 wt%, and the concentration of graphene oxide in the mixed solution is 0.3 - 0.7 wt%.

[0015] Preferably, the concentration of the concentrated HCl is 36% - 38%; the volume ratio of deionized water to concentrated HCl is 50 - 100:1; the molar ratio of FeCl3 to pyrrole is 2.2 - 2.4:1; the volume ratio of pyrrole to concentrated HCl is 0.5 - 1:1.

[0016] Preferably, the time for the dust-free paper to be immersed in the mixed solution composed of deionized water and concentrated HCl is 20 - 40 min; the washing is with deionized water; the drying is in an oven at 50 - 60 °C for 20 - 30 min.

[0017] Preferably, in step (2), the freeze-drying is carried out at -35 to -40 °C and 20 - 30 Pa, and the freeze-drying time is 36 - 48 h.

[0018] Preferably, in step (3), the concentration of the CaCl2 solution is 2 - 2.5%, and the mass concentration of LiCl is 3 - 4 wt%.

[0019] Preferably, in step (3), the soaking time in the CaCl2 solution is 24 - 30 h, and the soaking time in the LiCl solution is 8 - 12 h.

[0020] Preferably, in step (3), the pressing into thin flakes is performed by a tabletting machine, and the pressure applied by the tabletting machine is 20-27 Mpa, and the pressing time is 30-40 s.

[0021] A moisture-powered electrical device is prepared by the above preparation method.

[0022] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0023] 1) The moisture-powered electrical device of the present invention can maintain structural stability in water and can achieve long-term stable power generation for 27 h in the environment (~25 °C, RH = ~60%), and the output open-circuit voltage can reach 0.7 V.

[0024] 2) The preparation method of the moisture-powered electrical device of the present invention is simple, and the price of raw materials is low, which is conducive to large-scale industrial production.

[0025] 3) The moisture-powered electrical device prepared by the present invention has easily available raw materials, low cost, and a simple preparation method, is suitable for large-scale industrial production, and the obtained moisture-powered electrical device has excellent power generation performance. Description of the Drawings

[0026] Figure 1 FTIR diagrams of polypyrrole-modified dust-free paper, pure polypyrrole, and dust-free paper prepared in Example 1;

[0027] Figure 2 SEM diagram of polypyrrole-modified dust-free paper prepared in Example 1;

[0028] Figure 3 EDS diagram of polypyrrole-modified dust-free paper prepared in Example 1; [[ID=SO]]

[0029] Figure 4 Contact angle diagram of polypyrrole-modified dust-free paper prepared in Example 1;

[0030] Figure 5 Conductivity test diagram of polypyrrole-modified dust-free paper prepared in Example 1;

[0031] Figure 6 Self-charging and discharging performance diagram of the moisture-powered electrical device prepared in Example 3;

[0032] Figure 7 Voltage and current density diagram of the moisture-powered electrical device prepared in Example 3 under different load resistances;

[0033] Figure 8 Output power density of the moisture-powered electrical device prepared in Example 3 under different load resistances;

[0034] Figure 9CV diagrams of the moisture-powered device prepared in Example 3 at different scanning rates;

[0035] Figure 10 Open-circuit voltage diagram output by the moisture-powered device prepared in Example 3;

[0036] Figure 11 Ambient temperature and humidity change diagram during the open-circuit voltage test of the moisture-powered device prepared in Example 3. Detailed implementation manners

[0037] To better understand the present invention, the following further describes the present invention in conjunction with the accompanying drawings and specific embodiments, but the implementation manners of the present invention are not limited thereto. The described embodiments are some embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0038] The dust-free paper is composed of 55% cellulose and 45% polyester fiber, has excellent flexibility and hydrophilicity, and at the same time has rich active groups on the surface for modification, and is a suitable carrier for electrode materials.

[0039] Polypyrrole (PPy) is a common conductive polymer with good conductivity, and pyrrole monomers can be in-situ polymerized by simple electrochemical oxidation or chemical oxidation methods, which makes polypyrrole often used as a conductive modifier to coat on materials to endow or improve their conductivity.

[0040] On this basis, the present invention uses the in-situ oxidation polymerization method to prepare a flexible and highly conductive polypyrrole-modified dust-free paper electrode (PPy-CRW), and uses sodium alginate (SA) with rich carboxylic acid functional groups and easy cross-linking as the MEG matrix material to prepare a flexible MEG device.

[0041] Specifically, a preparation method of a moisture-powered device of the present invention is to first prepare polypyrrole-modified dust-free paper; then sequentially place the polypyrrole-modified dust-free paper, sodium alginate / graphene oxide mixed solution, and polypyrrole-modified dust-free paper in directional freeze-drying, freeze with liquid nitrogen and then perform freeze-drying; then soak the freeze-dried product in a CaCl2 solution, press it into a thin sheet, soak it in a LiCl solution, and dry it to obtain a moisture-powered device.

[0042] There are related practices in the prior art for the polypyrrole-modified dust-free paper of the present invention. The specific preparation method is: immerse the dust-free paper in a mixed solution composed of deionized water and concentrated HCl, add pyrrole (Py), stir and then add an FeCl3 solution, react at 4 - 8 °C for 12 - 24 h, wash and dry to obtain polypyrrole-modified dust-free paper.

[0043] Combined with the object of the present invention, through testing, it is preferred that the concentration of sodium alginate in the mixed solution is 0.6 - 1.3 wt%, and the concentration of graphene oxide in the mixed solution is 0.3 - 0.7 wt%. It is preferred that the concentration of concentrated HCl is 36% - 38%; the volume ratio of deionized water to concentrated HCl is 50 - 100:1; the molar ratio of FeCl3 to pyrrole is 2.2 - 2.4:1; the volume ratio of pyrrole to concentrated HCl is 0.5 - 1:1.

[0044] It is preferred that the time for the dust-free paper to be immersed in the mixed solution composed of deionized water and concentrated HCl is 20 - 40 min.

[0045] The washing and drying of the above-mentioned dust-free paper preparation are conventional practices. It is preferred to wash with deionized water; drying is carried out in an oven at 50 - 60 °C for 20 - 30 min.

[0046] The freeze-drying of the present invention is preferably carried out at -35 to -40 °C and 20 - 30 Pa, and the freeze-drying time is 36 - 48 h.

[0047] It is preferred that the concentration of the CaCl2 solution is 2 - 2.5%, and the mass concentration of LiCl is 3 - 4 wt%.

[0048] It is preferred that the soaking time in the CaCl2 solution is 24 - 30 h, and the soaking time in LiCl is 8 - 12 h.

[0049] It is preferred that pressing into a thin sheet is carried out by a tablet press, the pressure applied by the tablet press is 20 - 27 Mpa, and the pressing time is 30 - 40 s.

[0050] Compared with traditional metal electrodes, the amino groups in the polypyrrole-modified dust-free paper electrode can interact with the oxygen-containing groups in the MEG material, enhancing the effective contact between the MEG material and the electrode material, and by introducing CNT-COOH, hygroscopic salt LiCl, and Ca 2+ crosslinking, respectively enhancing the conductivity, moisture absorption capacity, and structural stability of the active material. The open-circuit voltage of this device can reach 0.7 V, and it is stable for a long time in ambient temperature and humidity. The short-circuit current can reach up to 2 mA at most, and the maximum output power density reaches 37 μW / cm 3 This provides a new idea for the design of new moisture-powered generator devices.

[0051] Example 1:

[0052] The preparation of the polypyrrole-modified dust-free paper described in the present invention is specifically carried out as follows:

[0053] (1) Take 300 mL of deionized water in a plastic container, and add 3 mL of concentrated HCl thereto with a pipette, and stir at room temperature for 5 - 10 min.

[0054] (2) Place a 5×15 cm 2 dust-free paper into the solution and soak it for 20 - 40 min to allow HCl to fully penetrate the dust-free paper.

[0055] (3) Use a pipette to add 1.5 mL of pyrrole (Py) to the solution described in step (2) and stir for 3 h.

[0056] (4) Ensure that the molar ratio of FeCl3 / Py is 2.4:1, add a 1 mol / L FeCl3 solution dropwise to the solution described in step (3), seal the container, and place it at 4 - 8 °C for reaction for 12 - 24 h.

[0057] (5) Wash the polypyrrole-modified dust-free paper obtained in step (4) with deionized water, place it in an oven at 50 - 60 °C and dry it for 20 - 30 min, and cut it into a size of 6×5 cm 2 for standby.

[0058] Figure 1 FTIR diagrams of the polypyrrole-modified dust-free paper prepared in Example 1, pure polypyrrole, and dust-free paper; as can be seen from Figure 1 it, the polypyrrole-modified dust-free paper prepared in Example 1 has a characteristic peak of polypyrrole N-H at 785 cm -1 ;

[0059] Figure 2 SEM diagram of the polypyrrole-modified dust-free paper prepared in Example 1; Figure 3 EDS diagram of the polypyrrole-modified dust-free paper prepared in Example 1; as can be seen from Figures 2 - 3 it, in the polypyrrole-modified dust-free paper prepared in Example 1, polypyrrole can be evenly distributed on the dust-free paper;

[0060] Figure 4 Contact angle diagram of the polypyrrole-modified dust-free paper prepared in Example 1; Figure 4 It shows that the contact angle of the polypyrrole-modified dust-free paper prepared in Example 1 is 0°, indicating that the polypyrrole-modified dust-free paper prepared in this Example 1 has superhydrophilicity.

[0061] Figure 5 Conductivity test diagram of the polypyrrole-modified dust-free paper prepared in Example 1; Figure 5 It can be seen that the polypyrrole-modified dust-free paper can act as a wire in the circuit to light up the bulb and has conductivity.

[0062] Example 2:

[0063] The preparation of the sodium alginate / graphene oxide mixed solution described in the present invention is specifically as follows:

[0064] (1) Weigh 1 g of sodium alginate powder, disperse it in 99 g of deionized water, and stir it in a water bath at 60 - 70 °C for 3 - 5 h to obtain a clear 1 wt% sodium alginate solution.

[0065] (2) Add the graphene oxide dispersion to the solution obtained in step (1). During this process, the mass ratio of the sodium alginate solution to the graphene oxide dispersion is 1.5 - 2:1.

[0066] (3) Magnetically stir the mixed solution obtained in step (2) for 20 - 30 min and ultrasonicate it for 10 - 20 min.

[0067] Example 3:

[0068] The preparation of the moisture - powered electrical device described in the present invention is as follows:

[0069] (1) Place the mixed solution obtained in Example 2 and the polypyrrole dust - free paper electrode obtained in Example 1 in the freeze - drying mold in the order of modified dust - free paper - mixed solution - modified dust - free paper (5×5×3 cm 3 ), and freeze it with liquid nitrogen.

[0070] (2) Send the sample frozen in step (1) to a freeze - dryer for freeze - drying at a temperature of - 40 °C and a pressure of 20 Pa.

[0071] (3) Immerse the sample obtained in step (4) in 2 w% CaCl2 solution for 24 - 30 h, then immerse it in 4 wt% LiCl solution for 8 - 12 h, and after drying, the moisture - powered electrical device is obtained.

[0072] Figure 6 Figure of the self - charging and discharging performance of the moisture - powered electrical device prepared in Example 3; as can be Figure 6 seen, the moisture - powered electrical device prepared in Example 3 can achieve self - charging and discharging in the environment, with an open - circuit voltage reaching 0.7 V and a maximum short - circuit current reaching 2 mA.

[0073] Figure 7 Figure of the voltage and current density of the moisture - powered electrical device prepared in Example 3 when loaded with different resistances; as can be Figure 7 seen, when the external resistance of the moisture - powered electrical device prepared in Example 3 increases from 1 Ω to 1 MΩ, the output voltage increases from 0 V to 600 mV, while the output current density gradually decreases from 175 μA·cm -2 to 0, and the highest output power is reached when the external load is 8 kΩ.

[0074] Figure 8 Figure of the output power density of the moisture - powered electrical device prepared in Example 3 when loaded with different resistances; as can be Figure 8It can be seen that the moisture-powered device prepared in Example 3 reaches the highest output power density when the external load is 8 kΩ, and its highest power density reaches 37 μW / cm 2 .

[0075] Figure 9 Figure is the CV diagram of the moisture-powered device prepared in Example 3 at different scanning rates; from Figure 9 it can be seen that there are no oxidation-reduction peaks in the CV diagrams of the moisture-powered device prepared in Example 3 at different scanning rates, indicating that the electrodes will not be oxidized and corroded during operation.

[0076] Figure 10 Figure Figure 9 is the open-circuit voltage diagram output by the moisture-powered device prepared in Example 3; from Figure 10 it can be seen that the moisture-powered device prepared in Example 3 can achieve continuous power generation for 27 hours, and the output open-circuit voltage can reach 0.7 V, indicating good power generation performance and continuous power generation performance.

[0077] Figure 11 Figure is the diagram of the environmental temperature and humidity changes when testing the open-circuit voltage of the moisture-powered device prepared in Example 3. From Figure 11 it can be seen that during the open-circuit voltage output test, the environmental temperature ranges from 25 to 28 °C, and the relative humidity ranges from 50 to 70%. However, the open-circuit voltage shows a stable output trend, indicating that the moisture-powered device prepared in Example 3 has the characteristic of stable power generation.

[0078] As can be seen from the above embodiments, the moisture-powered device of the present invention can maintain structural stability in water and can achieve long-term stable power generation for 27 h in the environment (~25 °C, RH = ~60%), and the output open-circuit voltage can reach 0.7 V.

[0079] The preparation method of the moisture-powered device of the present invention is simple, and the price of raw materials is low, which is conducive to large-scale industrial production.

[0080] The moisture-powered device prepared by the present invention has easily available raw materials, low cost, and a simple preparation method, is suitable for large-scale industrial production, and the obtained moisture-powered device has excellent power generation performance.

[0081] It should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A preparation method of a moisture power generation device, characterized in that It includes the following steps: (1) Prepare polypyrrole-modified dust-free paper; (2) Place the polypyrrole-modified dust-free paper, sodium alginate / graphene oxide mixed solution, and polypyrrole-modified dust-free paper in sequence in directional freeze-drying, freeze with liquid nitrogen, and then perform freeze-drying; (3) Immerse the freeze-dried product in a CaCl2 solution, press it into a thin sheet, immerse it in a LiCl solution, and dry it by blowing to obtain a moisture-powered electrical device.

2. The preparation method according to claim 1, characterized in that: The preparation method of the polypyrrole-modified dust-free paper is as follows: Immerse the dust-free paper in a mixed solution composed of deionized water and concentrated HCl, add pyrrole, stir, then add an FeCl3 solution, react at 4-8 °C for 12-24 h, wash, and dry to obtain the polypyrrole-modified dust-free paper.

3. The preparation method according to claim 2, characterized in that: The concentration of sodium alginate in the mixed solution is 0.6-1.3 wt%, and the concentration of graphene oxide in the mixed solution is 0.3-0.7 wt%.

4. The preparation method according to claim 2, characterized in that: The concentration of the concentrated HCl is 36% - 38%; the volume ratio of deionized water to concentrated HCl is 50-100:1; the molar ratio of FeCl3 to pyrrole is 2.2-2.4:1; the volume ratio of pyrrole to concentrated HCl is 0.5-1:

1.

5. The preparation method according to claim 2, characterized in that: The time for the dust-free paper to be immersed in the mixed solution composed of deionized water and concentrated HCl is 20-40 min; the washing is with deionized water; the drying is at 50-60 °C in an oven for 20-30 min.

6. The preparation method according to claim 1, characterized in that: In step (2), the freeze-drying is carried out at -35 to -40 °C and 20-30 Pa, and the freeze-drying time is 36-48 h.

7. The preparation method according to claim 1, characterized in that: In step (3), the concentration of the CaCl2 solution is 2-2.5%, and the mass concentration of LiCl is 3-4 wt%.

8. The preparation method according to claim 1, wherein: In step (3), the immersion time in the CaCl2 solution is 24-30 h, and the immersion time in the LiCl solution is 8-12 h.

9. The preparation method according to claim 1, wherein: In step (3), the pressing into a thin sheet is carried out by a tablet press, and the pressure applied by the tablet press is 20-27 Mpa, and the pressing time is 30-40 s.

10. A moisture power generation device, characterized in that, It is obtained by the preparation method described in any one of claims 1 to 9.

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