A double-layer polymer film-based rechargeable moisture power generation device and a preparation method thereof

Abstract

The application relates to a double-layer polymer film-based rechargeable moisture power generation device and a preparation method thereof, and belongs to the technical field of moisture power generation. The device comprises an active electrode, a double-layer polymer film and an inert porous electrode which are sequentially arranged, wherein the first layer polymer film of the double-layer polymer film is a mixture of iron hydroxide, polystyrene sulfonic acid and polyvinyl alcohol, the second layer polymer film is polydiallyldimethylammonium chloride, the first layer polymer film is in contact with the active electrode, and the second layer polymer film is in contact with the inert porous electrode; the material of the active electrode is a metal with a standard electrode potential of-1V to +0.5V, and the material of the inert porous electrode is a metal with a standard electrode potential greater than +1V. Through moisture evaporation and redox reaction, the battery can generate power spontaneously in a moisture environment, and can be self-repaired through the redox reaction when the performance decreases, so that the charging effect is realized.

Description

Technical Field

[0001] The invention relates to a rechargeable wet gas power generation device based on a double-layer polymer membrane and a preparation method thereof, belonging to the technical field of wet gas power generation. Background Art

[0002] The depletion of traditional fossil fuels and the high demand for energy in human development are prompting researchers to develop green, environmentally friendly, and sustainable new energy systems. With the continuous advancement of science and technology, clean energy technologies such as wind, geothermal, and tidal energy are becoming increasingly mature. However, they still face two major challenges: first, they are subject to significant natural constraints and are easily affected by external factors such as topography and climate; second, they require the construction of large-scale equipment, which is costly and can cause environmental damage. In recent years, emerging energy technologies such as solar cells, piezoelectric nanogenerators, triboelectric nanogenerators, and thermoelectric nanogenerators have emerged, aiming to convert solar, mechanical, and thermal energy into electricity, thereby alleviating the global energy crisis. However, these technologies are susceptible to specific weather conditions. Severe vibrations and large temperature fluctuations can reduce their power generation performance, hindering their further application. Humidity is ubiquitous on Earth, originating from the evaporation of large amounts of water from lakes, rivers, and oceans. As research deepens, scientists have discovered that water can directly interact with many materials with unique structures. Studies as early as 2009 have shown that when cellulose, hydrophilic particles, and even metals are exposed to high relative humidity, their surfaces can generate excessive charges. The transition of water from its gaseous to adsorbed state is often accompanied by the formation and destruction of hydrogen bonds. This process continuously generates heat exchange, material deformation, and ion dissociation, generating weak electricity. This phenomenon later became known as moisture-enabled electricity generation (MEG). Compared to other energy conversion technologies, MEG offers advantages such as simple device structure, ease of fabrication, excellent performance, and environmental friendliness. The electricity generated by MEG relies on the ubiquitous presence of moisture in the environment, requiring no additional energy input, thus breaking environmental and geographical constraints. These advantages give MEG enormous potential for application and mechanization. Over the past few years, MEG's power generation performance has improved by several orders of magnitude, now sufficient to power small electronic devices such as calculators, liquid crystal displays, electronic displays, and light-emitting diodes. Some of these flexible power-generating devices have the potential to be used in portable and wearable electronic devices, harvesting energy from moisture in human breath and on the skin surface, and enabling functions such as health monitoring.

[0003] In less than a decade since its initial proposal, wet gas power generation technology has seen significant progress in expanding its portfolio of power generation materials, evolving from initial carbon-based nanomaterials such as carbon nanoparticles, carbon nanowires, graphene oxide, reduced graphene oxide, and graphyne to current bio-nanomaterials, polymers, metal oxides, and more. The lifetime of wet gas power generation devices has increased from a few hours to hundreds of hours, and output performance has improved by several orders of magnitude, representing significant progress. However, this still falls short of powering most electronic devices, and further improvements are needed. Achieving higher MEG output requires higher relative humidity and the generation of more and higher-valent charge carriers within the power generation material. This necessitates the design of power generation materials with more complex compositions and structures. Complex wet gas power generation materials are susceptible to external factors during operation, leading to changes in their internal chemical and physical properties. For example, the functional groups and asymmetric structures responsible for charge generation are susceptible to environmental damage, resulting in loss or collapse during long-term operation. Over time, MEG performance deteriorates or even fails completely, ultimately preventing commercialization. Therefore, there is a natural conflict between long MEG lifetime and high performance. Summary of the Invention

[0004] In view of this, the object of the present invention is to provide a rechargeable wet gas power generation device (rMEC) based on a double-layer polymer membrane. The power generation device includes a polystyrene sulfonic acid / Fe 3+ (PSSA / Fe 3+ The excellent output performance of this power generation device is not only due to the high-valent ion concentration difference formed after the double-layer polymer membrane absorbs water and dissociates, but also due to the active metal Fe electrode and PSSA / Fe 3+ The redox reaction between the layers plays an auxiliary role and greatly improves the power output. As the power generation time increases, the Fe 3+ However, when the rMEC is placed in a humid environment containing oxidizing substances, Fe 2+ Can be reoxidized to Fe 3+ , thus forming a new redox reaction and rebuilding the ion concentration gradient. This allows the performance of the rMEC to quickly recover to its initial level, achieving fast charging.

[0005] To achieve the above objectives, the technical solutions of the present invention are as follows.

[0006] A rechargeable wet gas power generation device based on a double-layer polymer membrane comprises an active electrode, a double-layer polymer membrane and an inert porous electrode arranged in sequence, wherein the first layer of the double-layer polymer membrane is a mixture of ferric hydroxide, polystyrene sulfonic acid and polyvinyl alcohol, and the second layer of the polymer membrane is polydiallyldimethylammonium chloride. The first layer of the polymer membrane contacts the active electrode, and the second layer of the polymer membrane contacts the inert porous electrode. The material of the active electrode is a metal with a standard electrode potential of -1V to +0.5V, and the material of the inert porous electrode is a metal with a standard electrode potential greater than +1V.

[0007] Preferably, in the first polymer film, based on the total mass of the first polymer film being 100%, the mass fraction of ferric hydroxide is 0.2% to 0.3%, the mass fraction of polystyrene sulfonic acid is 9.8% to 13.8%, and the mass fraction of polyvinyl alcohol is 87% to 90%.

[0008] Preferably, the thickness of the first polymer film is 50 to 70 microns.

[0009] Preferably, the thickness of the second polymer film is 30 to 50 microns.

[0010] Preferably, the active electrode material is one or more of chromium, zinc, iron, cadmium, indium, cobalt, nickel, tin, lead, tungsten, molybdenum and copper. More preferably, the active electrode material is one or more of iron, cobalt, nickel, copper and zinc.

[0011] Preferably, the inert electrode is a porous stainless steel plate plated with a gold, platinum or iridium film, and the gold film is in contact with the second polymer film.

[0012] A method for preparing a rechargeable wet gas power generation device based on a double-layer polymer membrane, the method comprising the following steps:

[0013] (1) Add ferric hydroxide powder to polystyrene sulfonic acid (PSSA) aqueous solution, stir and react for 48 to 72 hours, centrifuge and collect the supernatant after the reaction to obtain PSSA / Fe 3+ Solution; PSSA / Fe 3+ The solution is mixed evenly with a polyvinyl alcohol aqueous solution, coated on a substrate, and dried to obtain a first layer of polymer film on the substrate;

[0014] (2) uniformly spraying a polydiallyldimethylammonium chloride (PDDA) solution on the surface of the first polymer film, drying at 55-70° C. for 15-30 minutes to form a second polymer film, thereby obtaining a double-layer polymer film;

[0015] (3) The double-layer polymer membrane is placed between the active electrode and the inert porous electrode, with the first layer of the polymer membrane in contact with the active electrode and the second layer of the polymer membrane in contact with the inert porous electrode, thereby obtaining a rechargeable wet gas power generation device based on the double-layer polymer membrane.

[0016] Preferably, in step (1), the concentration of the polystyrene sulfonic acid (PSSA) aqueous solution is 30-35 wt%, the concentration of the polyvinyl alcohol aqueous solution is 10-15 wt%, and the PSSA / Fe 3+ The mass ratio of the solution to the polyvinyl alcohol aqueous solution is 7:1 to 15:1.

[0017] Preferably, in step (1), the product is dried at 45-50° C. for 4-5 hours.

[0018] Beneficial effects

[0019] The present invention provides a rechargeable wet gas power generation device based on a double-layer polymer membrane. Through moisture evaporation and redox reaction, the battery can generate electricity in a humid environment and self-repair through redox reaction when the performance degrades, thereby achieving a charging effect. When the double-layer polymer membrane absorbs moisture, the iron ions in the PSSA layer interact with water molecules to form a double electric layer. The evaporation of water on the surface of the material drives the unidirectional migration of counterions on the double electric layer, generating current. At the same time, the iron electrode undergoes redox reaction with the PSSA layer, increasing the ion concentration difference of the battery and enhancing the output performance of the battery. When it is placed in a humid environment containing oxidizing substances, Fe 2+ Reoxidized to Fe 3+ , rebuild the ion concentration gradient, restore battery performance and achieve charging effect.

[0020] The present invention provides a rechargeable wet gas power generation device based on a double-layer polymer membrane. The rechargeable wet gas battery combines wet gas power generation with redox reactions. A single battery can provide an output voltage of up to 1.08V and exhibits an excellent power density of 5.83μW cm -2 . When the performance of the rechargeable wet gas battery declines due to the consumption of internal carriers, the reversibility of the redox reaction can be used for self-repair to achieve a charging effect. The rechargeable wet gas battery can complete 100 working / charging cycles continuously and operate stably for more than 2080 hours. In addition, exposing the battery with degraded performance to industrial wastewater / gas containing oxidizing substances can also achieve a charging effect, which promotes the reuse of waste resources. The introduction of the environmentally friendly rechargeable wet gas battery not only overcomes the defect of non-reusability of traditional wet gas power generation devices, but also provides a new opportunity for further iteration and upgrading of wet gas power generation technology. This breakthrough will bring creative changes to the field of clean energy and inject new vitality into the construction of a green and sustainable energy system. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Schematic diagram of the preparation of the double-layer polymer film in Example 1.

[0022] Figure 2 Schematic diagram of the structure of the rMEG device in Example 1.

[0023] Figure 3 This is a physical picture of the rMEC device in Example 1.

[0024] Figure 4 This is an SEM image of the cross section of the double-layer polymer film of Example 1.

[0025] Figure 5 This is a graph showing the voltage variation over time for the rMEG device in Example 1.

[0026] Figure 6 This is a photo of the integrated rMEG device in Example 2 lighting up a small light bulb.

[0027] Figure 7 This is a diagram showing the actual charging of the rMEG device by oxidizing solution vapor and the output voltage diagram in Example 3.

[0028] Figure 8 This is a physical picture of the oxidizing solution in Example 3.

[0029] Figure 9 1 is a comparison chart of open circuit voltage and short circuit current in Example 1, Example 4 and Comparative Examples 1-2.

[0030] Figure 10 This is a line graph of power density versus load resistance in Example 5.

[0031] Figure 11 The voltage change diagram of 100 charge and discharge cycles in Example 6 and the voltage recovery rate after each charge. DETAILED DESCRIPTION

[0032] The present invention will be further described in detail below with reference to specific embodiments.

[0033] The test equipment used in the following examples is as follows:

[0034] Digital SourceMeter: Keithley (2612).

[0035] Scanning electron microscope: SUPRA 55, Zeiss.

[0036] High-purity gold target: 99.999%, Zhongnuo New Materials (Beijing) Technology Co., Ltd.

[0037] Example 1

[0038] Step 1: In a 250 ml beaker, weigh 5 g of a 30 wt% polystyrene sulfonic acid (PSSA, molecular weight 75,000) solution and dilute it with 25 g of deionized water. Then, weigh 0.1 g of iron hydroxide powder and add it to the diluted PSSA solution. Stir thoroughly and react for 48 hours.

[0039] Step 2: Place the reaction solution into a centrifuge at 4000 rpm min -1 The mixture was centrifuged at 1000 rpm for 30 minutes to remove excess unreacted iron hydroxide powder. 10 g of polyvinyl alcohol powder was weighed into a 250 ml beaker, and 90 g of deionized water was added thereto. The mixture was stirred at 80° C. for 1 hour to obtain a 10 wt% polyvinyl alcohol (molecular weight 30,000-45,000) solution.

[0040] Step 3: After the supernatant after centrifugation is evenly mixed with the polyvinyl alcohol solution in a mass ratio of 10:1, 6 ml is slowly dripped into a culture dish and dried in an oven at 45°C for 4 hours to obtain the first layer of polymer film.

[0041] Step 4: If Figure 1 As shown (because PVA chain is the skeleton, PSSA / Fe 3+ (The PVA is attached to the surface of the PVA chains; it does not actually participate in the chemical reaction or moisture-generated electricity generation process, so the PVA is not shown.) On top of the first layer, a 35 wt% polydiallyldimethylammonium chloride solution (PDDA, molecular weight 450) was evenly sprayed in small amounts and multiple times using a spray gun. The film was then quickly dried in a forced-air dryer at 60°C for 20 minutes to prevent interpenetration between the two components of the double-layer polymer film. The thickness of the second sprayed polymer film was controlled by measuring it with a film thickness meter, resulting in a double-layer polymer film.

[0042] Step 5: A layer of gold film was plated on a stainless steel plate with holes (2 cm × 2 cm, pore diameter 0.8 mm) by ion sputtering as an inert porous electrode. Another iron sheet (2 cm × 2 cm, without holes) was used as an active electrode. The double-layer polymer film was placed between the inert porous electrode and the active electrode. The first layer of film (PSSA / Fe 3+ ) is in contact with the iron electrode, and the second film (PDDA) is in contact with the inert electrode. Figure 2 The sandwich structure shown.

[0043] Wet gas power generation devices such as Figure 3 Assembly shown: The entire device consists of a nitrogen cylinder, a wide-mouth bottle, deionized water, and a tube. Nitrogen flows into deionized water from the hose on the right. When the gas escapes from the hose on the left, it carries a large amount of water molecules to form moisture.

[0044] Figure 4From the SEM image of the double-layer membrane interface, it can be seen that the double-layer polymer composite membrane was successfully prepared. The polymer membrane composed of two functional layers with clear boundaries laid a good foundation for the subsequent establishment of ion concentration gradient.

[0045] Figure 5 The figure shows the change in discharge voltage over time when the device is exposed to moisture at a relative humidity of 85%. When constructing the device, the discharge voltage of a single device can be guaranteed to be around 1.2V. The inset shows the voltage output curve of the device during its initial operation. Figure 5 The results show that the wet gas power generation device can generate electricity continuously for more than 24 hours and the output voltage is stable above 0.65 V. This shows that the rMEG device prepared by this method has good electrical output performance.

[0046] Example 2

[0047] In this example, five rMEC device units prepared in Example 1 were connected in series to power a 0.1W LED bulb. The bulb was exposed to a humid environment for 24 hours. After the bulb became noticeably dimmed, it was exposed to an oxidizing humid environment for charging. After 30 minutes of charging, the bulb's brightness returned to the level of the bulb immediately after exposure to the humid environment. Figure 6 shown.

[0048] Example 3

[0049] In this example, nitric acid, potassium permanganate, and hypochlorous acid were prepared into an aqueous solution of a certain concentration to simulate industrial wastewater. The vapor of the solution containing oxidizing substances was directed toward the rMEG device prepared in Example 1 to charge the rMEG device.

[0050] Figure 8 To simulate the oxidizing solution of industrial wastewater, Figure 7 The output voltage of the rMEG device dropped significantly after 20 hours of continuous discharge, but recovered to a higher level after a brief exposure to moisture containing oxidizing substances.

[0051] Example 4

[0052] In this embodiment, the active electrode is copper, and the rest is the same as in Example 1.

[0053] Comparative Example 1

[0054] In this comparative example, the active electrode is replaced with silver, and the rest is the same as in Example 1.

[0055] Comparative Example 2

[0056] In this comparative example, the active electrode is replaced by an inert electrode of gold, and the rest is the same as in Example 1.

[0057] After soaking the wet gas power generation devices prepared in Examples 1 and 4 and Comparative Examples 1-2, the short-circuit current and open-circuit voltage were measured using a digital source meter. The results are as follows: Figure 9 shown.

[0058] from Figure 9 It can be seen that the rechargeable wet gas power generation devices prepared using the method of the present invention in Examples 1 and 4 can generate current and voltage during use. The change in the active electrode in Comparative Example 1 eliminated the redox reaction, affecting the voltage increase and carrier mobility, resulting in a decrease in the generated voltage and current. Comparative Example 2, which did not use an active electrode, produced the lowest output voltage and current in the series of experiments.

[0059] Example 5

[0060] The rechargeable wet gas power generation device prepared in Example 1 was connected in series with an adjustable resistor. The real-time current and voltage were measured using a Keithley (2612) digital source meter while changing the resistance. The test results are as follows: Figure 10 The load resistance is 10 6 The power density is maximum when Ω.

[0061] Example 6

[0062] The rechargeable wet gas power generation device prepared in Example 1 was placed in a wet environment to generate electricity for one hour, and then transferred to a wet environment containing an oxidizing substance to charge for one hour. The reciprocating cycle was repeated, and real-time measurement was performed using a Keithley (2612) digital source meter. Figure 11 As shown, the voltage recovery rate remained close to 100% during 100 charge and discharge cycles within 2080 hours, proving that the device has a good cycle life.

[0063] In summary, the invention includes but is not limited to the above embodiments. Any equivalent replacement or partial improvement made under the spirit and principle of the present invention shall be deemed to be within the scope of protection of the present invention.

Claims

1. A rechargeable wet gas power generation device based on a double-layer polymer membrane, characterized in that: The invention comprises an active electrode, a double-layer polymer membrane and an inert porous electrode arranged in sequence, wherein the first layer of the double-layer polymer membrane is a mixture of ferric hydroxide, polystyrene sulfonic acid and polyvinyl alcohol, and the second layer of the polymer membrane is polydiallyldimethylammonium chloride. The first layer of the polymer membrane contacts the active electrode, and the second layer of the polymer membrane contacts the inert porous electrode. The material of the active electrode is a metal with a standard electrode potential of -1V to +0.5V, and the material of the inert porous electrode is a metal with a standard electrode potential greater than +1V.

2. A rechargeable wet gas power generation device based on a double-layer polymer membrane according to claim 1, characterized in that: In the first polymer film, based on the total mass of the first polymer film being 100%, the mass fraction of ferric hydroxide is 0.2% to 0.3%, the mass fraction of polystyrene sulfonic acid is 9.8% to 13.8%, and the mass fraction of polyvinyl alcohol is 87% to 90%.

3. A rechargeable wet gas power generation device based on a double-layer polymer membrane according to claim 1 or 2, characterized in that: The thickness of the first polymer film is 50 to 70 microns.

4. A rechargeable wet gas power generation device based on a double-layer polymer membrane according to claim 1 or 2, characterized in that: The thickness of the second polymer film is 30 to 50 microns.

5. A rechargeable wet gas power generation device based on a double-layer polymer membrane according to claim 1 or 2, characterized in that: The active electrode material is one or more of chromium, zinc, iron, cadmium, indium, cobalt, nickel, tin, lead, tungsten, molybdenum and copper.

6. The rechargeable wet gas power generation device based on a double-layer polymer membrane according to claim 5, characterized in that: The active electrode material is one or more of iron, cobalt, nickel, copper and zinc.

7. A rechargeable wet gas power generation device based on a double-layer polymer membrane according to claim 1 or 2, characterized in that: The inert electrode is a porous stainless steel plate plated with a gold, platinum or iridium film, and the gold film is in contact with the second polymer film.

8. A method for preparing a rechargeable wet gas power generation device based on a double-layer polymer membrane according to any one of claims 1 to 7, characterized in that: The method steps include: (1) Add ferric hydroxide powder to polystyrene sulfonic acid aqueous solution, stir and react for 48 to 72 hours, centrifuge and collect the supernatant to obtain PSSA / Fe 3+ Solution; PSSA / Fe 3+ The solution is mixed evenly with a polyvinyl alcohol aqueous solution, coated on a substrate, and dried to obtain a first layer of polymer film on the substrate; (2) uniformly spraying a polydiallyldimethylammonium chloride solution on the surface of the first polymer film, drying at 55-70° C. for 15-30 minutes to form a second polymer film, thereby obtaining a double-layer polymer film; (3) The double-layer polymer membrane is placed between the active electrode and the inert porous electrode, with the first layer of the polymer membrane in contact with the active electrode and the second layer of the polymer membrane in contact with the inert porous electrode, thereby obtaining a rechargeable wet gas power generation device based on the double-layer polymer membrane.

9. The method for preparing a rechargeable wet gas power generation device based on a double-layer polymer membrane according to claim 8, wherein: In step (1), the concentration of the polystyrene sulfonic acid aqueous solution is 30-35 wt%, the concentration of the polyvinyl alcohol aqueous solution is 10-15 wt%, and the PSSA / Fe 3+ The mass ratio of the solution to the polyvinyl alcohol aqueous solution is 7:1 to 15:

1.

10. The method for preparing a rechargeable wet gas power generation device based on a double-layer polymer membrane according to claim 8, wherein: In step (1), drying is performed at 45-50° C. for 4-5 hours.

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