Materials, manufacturing method and device for converting ambient humidity to electrical energy and uses thereof

Abstract

The present invention relates to a modular converter for the continuous conversion of water vapor into electrical energy, comprising: a porous matrix comprising compressed metal oxide nanopowder wherein a first side of the porous matrix is covered by a functional layer partially infiltrating the porous matrix, preferably aluminum phosphate; a carbon electrode layer, preferably a graphite layer, on the active layer; a metal current collector or a carbon current collector on the carbon electrode layer; a Schottky electrode layer of metal Au, Ag, Al, Cu, Fe, Zn, Mg, Li, Ni, Co, Ti, Zr, Sn, Cr, Y, Nb, Mo, Rd, Pt, Cd, Hf, Ta, W, C or alloys thereof on the second side of the converter; and a metal current collector or a carbon current collector on the Schottky electrode layer, wherein the second surface of the converter is directly opposite the first surface of the converter.

Description

(19) State Intellectual Property Office (12) Invention Patent Application (10) Application Publication Number (43) Application Publication Date (21) Application Number 202480052893.6 (22) Application Date 2024.07.02 (30) Priority Data 118822 2023.07.17 PT (85) PCT International Application Entering National Phase Date 2026.02.11 (86) PCT International Application Application Data PCT / IB2024 / 056457 2024.07.02 (87) PCT International Application Publication Data WO2025 / 017403 EN 2025.01.23 (71) Applicant: Cascata Chuva Ltd. Address: Almada, Portugal (72) Inventors: Igor Danilenko, Oksana Gorban, Altem Hilos, Vitrana Lyubchik, Sergi Lyubchik, Andre Lyubchik (74) Patent Agency: Beijing Gaowo Law Firm, 11569 Patent Attorney: Wang Zixuan (51) Int.Cl. H01M 14 / 00 (2006.01) (54) Invention Title: Material, Manufacturing Method, Apparatus and Use Thereof for Converting Ambient Humidity into Electrical Energy (57) Abstract: This invention relates to a modular converter for continuously converting water vapor into electrical energy, comprising: a porous matrix containing compressed metal oxide nanoparticles, wherein a first side of the porous matrix is ​​covered by a functional layer that can partially penetrate the porous matrix, preferably aluminum phosphate; a carbon electrode layer, preferably a graphite layer, located on the active layer; a metal current collector or a carbon current collector located on the carbon electrode layer; and metals Au, Ag, Al, Cu, etc. located on the second side of the converter. Schottky electrode layer of Fe, Zn, Mg, Li, Ni, Co, Ti, Zr, Sn, Cr, Y, Nb, Mo, Rd, Pt, Cd, Hf, Ta, W, C or alloys thereof; and a metal current collector or carbon current collector located on the Schottky electrode layer, wherein the second surface of the converter is directly opposite the first surface of the converter. Claims 2 pages, Description 10 pages, Drawings 8 pages CN 121693818 A 2026.03.17 CN 1 21 69 38 18 A 1. A modular converter for continuously converting water vapor into electrical energy, comprising: a porous substrate containing compressed metal oxide nanopowder; a functional layer for inducing a concentration gradient of protons and OH− in the substrate; a carbon electrode layer; and a metal electrode layer for providing a Schottky electrode. 2. The converter according to the preceding claim, further comprising a metal current collector or a carbon current collector.3. The converter according to the preceding claim, wherein the converter comprises: a porous substrate comprising yttrium-stabilized zirconia nanopowder; a functional layer located on a first surface of the porous substrate for inducing a concentration gradient of protons and OH- ions in the substrate; a carbon electrode layer located on the functional layer; a metal current collector or a carbon current collector located on the first surface of the converter; a metal electrode layer located on a second surface of the converter for providing a Schottky electrode, wherein the metal electrode is selected from: Au, Ag, Al, Cu, Fe, Zn, Mg, Li, Ni, Co, Ti, Zr, Sn, Cr, Y, Nb, Mo, Pd, Pt, Cd, Hf, Ta, W, C, or alloys thereof; and a metal current collector or a carbon current collector located on the second surface of the converter. 4. The converter according to the preceding claim, wherein the second surface of the converter is directly opposite the first surface of the converter. 5. The converter according to any one of the preceding claims, wherein the porous matrix further comprises an additive, preferably 1-20 wt% activated carbon. 6. The converter according to any one of the preceding claims, wherein the functional layer is a phosphate layer, preferably an aluminum phosphate layer. 7. The converter according to any one of the preceding claims, wherein the carbon electrode layer is preferably a graphite layer. 8. The converter according to any one of the preceding claims, wherein the porous matrix comprises porous channels arranged perpendicular to the electrode layer. 9. The converter according to any one of the preceding claims, wherein the compressed metal oxide nanopowder is selected from: alumina, magnesium oxide, nickel oxide, iron oxide, calcium oxide, titanium dioxide, zirconium oxide, preferably zirconium oxide-based metal oxide, more preferably yttrium-stabilized zirconium oxide. 10. The converter according to any one of the preceding claims, wherein the compressed metal oxide nanopowder comprises 0 mol% to 20 mol%, preferably 0 mol% to 10 mol%, and even more preferably 8 mol% compressed yttrium-stabilized zirconium oxide nanopowder. 11. The converter according to any one of the preceding claims, wherein the thickness of the aluminum phosphate layer is 0.001 mm to 5 mm, preferably 0.02 mm to 0.2 mm, and even more preferably 0.05 mm. 12. The converter according to any one of the preceding claims, wherein the density of the porous substrate is 1 g / cm³ to 4 g / cm³, preferably 2.00 g / cm³ to 3.5 g / cm³, and even more preferably 2.5 g / cm³. 13. The converter according to claim 2 or any one of claims 2 and 3-12, wherein the current collector is a gold current collector or a gold-plated current collector.14. The converter according to any one of the preceding claims, wherein the converter is cylindrical, cuboid, or cubic. (Claims 1 / 2 page 2 CN 121693818 A) 15. The converter according to any one of the preceding claims, wherein the converter has at least one surface, the surface area of ​​which is from 1 cm² to 1000 cm², preferably from 3 cm² to 100 cm², more preferably 11.3 cm². 16. A building article comprising the converter according to any one of claims 1-15, wherein the article is a building cladding article, a building roofing article, or a building ceramic tile article. 17. Use of the converter according to any one of claims 1-15 as a building article, wherein the article is a building cladding article, a building roofing article, or a building ceramic tile article. 18. An apparatus for continuously converting water vapor into electrical energy, comprising at least two converters according to any one of claims 1-15, wherein the converters are connected in series, in parallel, or in a combination thereof. 19. A method for continuously converting water vapor into electrical energy using a converter according to any one of claims 1-15 or an apparatus according to claim 18, comprising the steps of: placing the converter or the apparatus in a humid environment, preferably with a relative humidity of at least 20%. Claims 2 / 2 Page 3 CN 121693818 A Materials, manufacturing methods, apparatus and applications for converting ambient humidity into electrical energy Technical Field

[0001] The present invention relates to a converter for converting water vapor / moisture into electrical energy, preferably ambient water vapor into electrical energy. Background Art

[0002] Ambient humidity is a huge reservoir of low potential energy contained in gaseous water molecules, which can be used as an alternative source of electrical energy. In recent years, the issue of energy independence has become increasingly prominent, which requires the development of micro and distributed energy sources for energy applications. These problems can be solved by using alternative energy sources (such as piezoelectric converters, frequency converters, etc.). Humidity-to-electricity converters are one of the possible types of devices for creating alternative energy sources that can power Internet of Things devices, smart homes, energy storage devices, etc.

[0003] The most likely mechanism for charge separation of normally neutral gaseous water molecules is their spontaneous dissociation into protons and OH- ions upon adsorption onto solid surfaces. Water droplets and ice can transfer some of these ions to other particles during melting, freezing, and collisions. Faraday discovered that a sufficient amount of condensed water droplets in vapor can immediately generate electricity. This effect is due to the fact that condensed water is a good conductor and that ions are transferred to metals or any other object due to friction.

[0004] Studies have shown that some metals spontaneously accumulate charge when exposed to high relative humidity (>50%).Based on the acid-base properties of metal surfaces, different metals exhibit different polarities due to the selective adsorption of water ions (OH− and H+). Measurements of surface acid-base properties using Kelvin force microscopy confirm that, depending on the Brønsted characteristics (acidic or basic) of the sample surface, it will selectively adsorb more OH− or H+ according to relative humidity. Studies have shown that charge transfer occurs on metal surfaces with oxide films possessing active centers. The research identifies the mechanism of charge exchange through Lewis and Brønsted centers on the oxide film surface. Therefore, stable oxide materials can be used instead of metals (whose properties change drastically during oxidation in humid atmospheres) as converter materials. Thus, the dissociation of water molecules into ions, and their selective adsorption at solid surface centers, can be used to separate the charge from initially neutral water vapor molecules. The implementation of a device based on this principle will accumulate electrical energy in the most environmentally friendly and simple way. Such a device is particularly promising for implementation in countries with high humidity.

[0005] The specific power of humidity-to-electricity converters is very low (0.01-4 μW / cm2) (see table below), but good overall performance can be achieved when simple and inexpensive materials are used in large-area converters.

[0006] Table 1. Electrical characteristics of humidity-to-electricity converters (based on literature) Specification 1 / 10 pages 4 CN 121693818 A

[0007] Studies have found that some non-metallic materials can generate electricity directly when exposed to moisture. These non-metallic materials are expensive and difficult-to-manufacture protein nanofibers, carbon nanoparticles, and graphene materials. Studies have shown that existing humidity-to-electricity converters can only generate intermittent pulse power. This is due to the presence and disappearance of the water molecule concentration gradient in the sample thickness (between contacts), which originates from the saturation of water on one side of the sample at the beginning of the power generation process, and the complete saturation of the sample when the water molecule concentration gradient in the sample thickness disappears over time.

[0008] Also known is a planar device made of titanium dioxide (TiO2) nanofibers that generates electricity using ambient moisture. As ambient humidity increases (>70% RH), spin-coated fibers deposited on glass generate a constant voltage. However, the output voltage of the TiO2 nanofiber device is highly dependent on ambient humidity and rapidly drops to zero (within 400 seconds) under non-constant humidity conditions. This unstable power is due to the sandwich structure of these converters, which is closed on one side, making it impossible to maintain a continuous flow of water molecules from the atmosphere. Once the film is saturated with water, the gradient disappears, and the generation of potential ceases.Therefore, the disadvantages of these components hinder their introduction into large-scale commercial applications. These disadvantages are: - The periodicity of the power generation process, i.e., the existence of a drying cycle, which is associated with the design characteristics of the thin-film technology used to manufacture the converter and the need to maintain a moisture gradient along the sample; - The existence of an unstable humidity gradient on the side of the converter, and / or the humidity gradient and the resulting potential sign may change in opposite directions when the evaporation / saturation rate of water molecules in the sample on the side of the converter changes.

[0009] Therefore, there is a need for a converter that can continuously convert ambient moisture into electrical energy using simple and inexpensive materials.

[0010] Currently, prior art converters made of oxide materials employ a planar design placed on a substrate and can only generate intermittent pulsed power due to the unstable humidity gradient.

[0011] These facts are disclosed to illustrate the technical problem solved by the present invention. Summary of the Invention

[0012] The present invention relates to a converter for converting water vapor into electrical energy, preferably ambient water vapor.

[0013] One aspect of the present invention relates to a modular converter for continuously converting water vapor into electrical energy, comprising: a porous matrix comprising compressed metal oxide nanoparticles; a functional layer for inducing a concentration gradient of protons and OH- in the matrix; a carbon electrode layer; a metal electrode layer for providing a Schottky contact with the matrix, wherein the metal electrode is selected from: Au, Ag, Al, Cu, Fe, Zn, Mg, Li, Ni, Co, Ti, Zr, Sn, Cr, Y, Nb, Mo, Pd, Pt, Cd, Hf, Ta, W, C or alloys thereof; and a metal current collector or a carbon current collector.

[0014] In one embodiment, a modular converter for continuously converting water vapor into electrical energy comprises: a porous substrate containing yttrium-stabilized zirconia nanopowder; a functional layer located on a first surface of the porous substrate for inducing a concentration gradient of protons and OH- in the substrate; a carbon electrode layer located on the functional layer; a metal current collector or a carbon current collector located on the first surface of the converter; a metal electrode layer located on a second surface of the converter for providing a Schottky electrode, wherein the metal electrode is selected from: Au, Ag, Al, Cu, Fe, Zn, Mg, Li, Ni, Co, Ti, Zr, Sn, Cr, Y, Nb, Mo, Pd, Pt, Cd, Hf, Ta, W, C, or alloys thereof; a metal current collector or a carbon current collector located on the second surface of the converter; wherein the second surface of the converter is directly opposite the first surface.

[0015] In one embodiment, the current collector is selected from Au, Ag, Al, Cu, Fe, Zn, Mg, Li, Ni, Co, Ti, Zr, Sn, Cr, Y, Nb, Mo, Pd, Pt, Cd, Hf, Ta, W, C, or alloys thereof.

[0016] In one embodiment, the porous matrix further comprises an additive, preferably 1-20 wt% activated carbon.

[0017] In one embodiment, the functional layer is a phosphate layer, preferably an aluminum phosphate layer.

[0018] In one embodiment, the carbon electrode layer is preferably a graphite layer.

[0019] In one embodiment, the porous matrix includes porous channels arranged perpendicular to the electrode layer.

[0020] In one embodiment, the compressed metal oxide nanoparticles are selected from: aluminum oxide, magnesium oxide, nickel oxide, iron oxide, calcium oxide, titanium dioxide, zirconium oxide, preferably zirconium oxide-based metal oxides, more preferably yttrium oxide-stabilized zirconium oxide.

[0021] In one embodiment, the compressed metal oxide nanopowder comprises 0 mol%-20 mol%, preferably 0 mol%-10 mol%, and even more preferably 8 mol% of compressed yttrium oxide-stabilized zirconium oxide nanopowder.

[0022] In one embodiment, the thickness of the aluminum phosphate layer is 0.001 mm-5 mm, preferably 0.02 mm-0.2 mm, and even more preferably 0.05 mm.

[0023] In one embodiment, the density of the porous matrix is ​​1 g / cm³-4 g / cm³, preferably 2.00-3.5 g / cm³, and even more preferably 2.5 g / cm³.

[0024] In one embodiment, the current collector is a gold current collector or a gold-plated current collector.

[0025] In one embodiment, the converter is cylindrical, cuboid, or cubic.

[0026] In one embodiment, the converter has a surface with a surface area of ​​1 cm² to 1000 cm², preferably 3 cm² to 100 cm², more preferably 11.3 cm².

[0027] Another aspect of the invention relates to a building article comprising the converter described herein, wherein, according to the product specification 3 / 10 pages 6 CN 121693818 A, it is a building cladding article, a building roofing article, or a building ceramic tile article.

[0028] Another aspect of the invention relates to the application of the converter described herein as a building article, wherein the article is a building cladding article, a building roofing article, or a building ceramic tile article.

[0029] Another aspect of the invention relates to a device for continuously converting water vapor into electrical energy, comprising at least two converters described herein, wherein the converters are connected in series, in parallel, or in a combination thereof.

[0030] Another aspect of the invention relates to a method for continuously converting water vapor into electrical energy using the converter or device described in the invention, comprising the steps of: placing the converter or device in a humid environment, preferably with a relative humidity of at least 20%.

[0031] One aspect of the invention relates to a converter for continuous operation in the absence of a water vapor gradient in the atmosphere on two opposite sides of the converter. To address this problem, one side of the converter is covered with a thin layer of material having adsorption properties different from those of the converter material and / or generating charged ions (protons or OH- groups) upon interaction with water molecules in the atmosphere. In this case, the converter may have a densely packed structure in the form of a 3D plate and generate electrical energy at any point in the space where the relative humidity level is at least 20%.

[0032] One aspect of the invention relates to a modular converter configured to operate continuously based on the continuous movement of adsorbed water molecule ions along porous channels in the absence of an external water vapor gradient.

[0033] In one embodiment, the converter comprises a porous matrix having a disordered and / or structured distribution of porous channels, the (capillary) channels being formed by pores between material powder particles.

[0034] In one embodiment, the walls (or particle surfaces) of the porous channel have specific centers (Lewis and Brønsted) that possess specific forces that allow water molecules to be adsorbed and desorbed without forming a stable bond with the walls of the porous channel.

[0035] In one embodiment, the porous matrix comprises nanopowder obtained by a compaction method (e.g., uniaxial, cold isostatic pressing, etc.).

[0036] In one embodiment, the size of the nanopowder particles is 4-50 nm, preferably 7-25 nm, more preferably 7-13 nm. Particle size refers to the particle size obtained by visual inspection of the particle sample using a scanning electron microscope (SEM) or a transmission electron microscope (TEM), typically referring to the maximum observable particle size of a single particle.

[0037] In one embodiment, the thickness of the converter is 0.1 mm-12 mm, preferably 7 mm.

[0038] In one embodiment, the converter further includes a phosphate functional layer located on one surface of the converter.

[0039] In one embodiment, the thickness of the phosphate functional layer is 0.001-5 mm, preferably 0.02-0.2 mm, and more preferably 0.05 mm.

[0040] In one embodiment, the phosphate functional layer interacts with ambient water vapor adsorbed onto the surface of the converter. This interaction alters the equilibrium density of water ions (protons and OH- groups) between the covered side and the opposite side of the converter, thereby resulting in an internal moisture gradient along the converter, independent of external conditions.

[0041] In one embodiment, the phosphate functional layer generates charged ions (protons) during interaction with water molecules adsorbed on the surface of the converter, thereby forming a moisture gradient in the converter. This definitively determines the direction of the generated current, and this direction is independent of external adsorption / desorption conditions on both sides of the converter.

[0042] In one embodiment, the converter of the present invention is modular and can be connected with more converters to form a converter group in series, parallel, or a combination thereof.

[0043] In one embodiment, the converter is capable of operating in the absence of an external water vapor gradient. Its advantage is that the converter can be assembled into a modular device to obtain a compact converter group, and there is no spontaneous sign change of one or more converters during operation.

[0044] In one embodiment, the converter comprises compressed metal oxide powder (zirconia, alumina, titanium oxide, doped zirconia, etc.), preferably zirconia-based powder, more preferably yttrium-stabilized zirconia powder, and even more preferably 8 mol% yttrium-stabilized zirconia nanoparticles (ZrO2-8 mol% Y2O3, hereinafter referred to as 8YSZ).

[0045] In one embodiment, the converter further comprises a phosphate functional layer on one surface of the converter and an inert conductive electrode on one surface of the converter, preferably the electrode being deposited on the phosphate layer.

[0046] In one embodiment, the inert conductive electrode is a carbon electrode.

[0047] In one embodiment, the converter has an electrode region with the same size as one surface of the converter. Preferably, the inert electrode covers the entire area of ​​one surface of the converter.

[0048] In one embodiment, the converter has a current collector made of an inert metal electrode of one type, preferably gold or gold-plated.

[0049] In one embodiment, the converter has a current collector made of different types of metal or carbon electrodes, preferably gold on the side of the converter covered by the phosphate functional layer.

[0050] In one embodiment, the converter has electrodes on a second surface of the converter for providing Schottky electrodes, wherein the converter on the second surface is made of different types of metal or carbon, preferably selected from: Ag, Al, Cu, Fe, Zn, Li, Mg, or other p-, d-, or f- elements in the periodic table.

[0051] In one embodiment, the thickness of the converter is 0.1 mm to 12 mm, preferably 7 mm.

[0052] In one embodiment, the mass of the converter is 0.5 g to 20 g, preferably 12 g.

[0053] In one embodiment, the density of the converter is 1.7 to 3.0 g / cm3, preferably 2.5 g / cm3.

[0054] In one embodiment, the converter is cylindrical, rectangular, or other shaped, with an end face area of ​​1 cm² to 1000 cm², preferably 3 cm² to 100 cm², and more preferably 11.3 cm².

[0055] In one embodiment, when the converter is placed at a relative humidity of 20%–100%, the converter is able to convert ambient water vapor into electrical energy.

[0056] In one embodiment, a converter with a surface area of ​​1.1 × 10⁻³ m² is able to continuously generate 11 × 10⁻³ W under a 100 Ohm load. The open-circuit voltage is up to 2.8 V, and the short-circuit current is up to 23 mA. These values ​​are 400 to 1000 times greater than those obtained in the prior art.

[0057] In one embodiment, the converter of the present invention can generate up to 39.6 J of energy within a characteristic time of 1 hour.

[0058] The present invention shows that the particle size, surface acidity, and porosity (density) of the porous converter material affect the energy conversion efficiency of the converter.

[0059] In one embodiment, the converter comprises compressed oxide powder, preferably zirconia-based powder, more preferably yttrium-stabilized zirconia powder, and even more preferably 8 mol% yttrium-stabilized zirconia nanoparticles (ZrO2-8 mol% Y2O3, hereinafter referred to as 8YSZ), to which 0.1 to 15 wt% coal (in the form of graphite, expanded graphite, graphene, activated carbon, etc.) is added. The maximum amount of coal is limited by the brittle properties of the converter.

[0060] These humidity-to-electricity converters made of oxide powder can be used as building materials, while simultaneously performing the functions of generating electricity and building products (wall cladding, panels, etc.). Brief Description of the Drawings

[0061] The following drawings provide for illustrating preferred embodiments of the invention and should not be considered as limiting the scope of the invention. Instruction manual, page 5 / 10, CN 121693818 A

[0062] Figure 1 shows the X-ray diffraction pattern (Figure 1a), transmission electron microscope image (Figure 1b), and scanning electron microscope image (Figure 1c) of 8YSZ nanopowder and compressed converter material.

[0063] Figure 2a shows the converter design, Figure 2b shows the converter circuit diagram, and Figure 2c shows the converter schematic diagram.

[0064] Figure 3 shows the test scheme.

[0065] Figure 4 shows the output voltage of 8YSZ converters with and without phosphate functional layers during continuous power generation in a compartment with a humidity level of 60% RH.

[0066] Figure 5 shows the output voltage (open circuit and under load) of 8YSZ converters with phosphate functional layers over time.

[0067] Figure 6 shows the open circuit voltage and load voltage of 8YSZ converters with phosphate and magnesium functional layers over time.Figure 6 shows the change of converter output voltage over time obtained from α-modified alumina (Figure 6a) and γ-modified alumina (Figure 6b), titanium oxide (Figure 6c), and nickel-doped zirconium oxide (Figure 6d) at ambient humidity levels.

[0068] Figure 7 shows a schematic diagram of potential generation in porous oxide materials.

[0069] Reference numerals 1. Metal current collector with substrate for providing Schottky electrode 2. Functional layer for inducing concentration gradient (proton and OH-) in the substrate 3. Porous substrate 4. Water vapor 5. Channel in porous substrate 6. Channel wall 7. Proton 8. OH- group Detailed Description

[0070] The present invention relates to a converter for converting water vapor into electrical energy, preferably ambient water vapor into electrical energy.

[0071] In one embodiment, the converter of the present invention comprises zirconium oxide nanopowder, preferably zirconium oxide nanopowder stabilized with 8 mol% yttrium oxide (ZrO2-8 mol% Y2O3, hereinafter referred to as 8YSZ). The advantage of using ZrO2-8 mol%Y2O3 is that the material is in a stable cubic (Fm3m) crystal variant, thus eliminating the possibility of a phase transition when the material interacts with water vapor.

[0072] In one embodiment, ZrO2-8 mol%Y2O3 (8YSZ) nanopowder was obtained by coprecipitation. The nanopowder was synthesized by coprecipitation using ZrOCl2·nH2O and Y(NO3)3 salt. After a final filtration, the precipitate was dried in a microwave oven with an output power of 900 W and a frequency of 2.45 GHz. The dried zirconium-yttrium hydroxide was calcined in a resistance furnace at 400 °C for 2 hours

[14] .

[0073] In one embodiment, the synthesized nanopowder was used to prepare porous matrices of different sizes. The nanopowder is compacted in a metal mold at 30 MPa to 300 MPa, or compacted in a metal mold at 30 MPa, and then isostatically compacted (CIP) in a rubber shell at 100–400 MPa in VG32 oil.

[0074] In one embodiment, the functional layer for generating a moisture gradient in the converter is made of aluminum phosphate deposited on one side of the converter. The thickness of the layer is 0.001–5 mm, preferably 0.02–0.2 mm. The aluminum phosphate functional layer interacts with the zirconia converter material by heating the converter at 400°C for 1 hour.

[0075] In one embodiment, the nanopowder and the compressed matrix are characterized by X-ray diffraction (XRD) analysis using a Dron-3 diffractometer with Cu-Kα radiation (IC "Bourevestnik", specification 6 / 10 pages 9 CN 121693818 A USSR).

[0076] In one embodiment, the nanopowder was also evaluated by transmission electron microscopy (TEM). The porous structure of the converter material was analyzed by scanning electron microscopy (SEM). The density and porosity of the converter material were measured using the Archimedes method.

[0077] In one embodiment, the dominant charge on the surface of the porous nanopowder matrix was determined based on the change in the integrated acidity of the suspension over time (pH = f(t)), a method based on pH. A pH 700 (Eutech Instruments, Singapore) was used as the pH analyzer. The surface integrated acidity was estimated as follows: 40 mL of distilled water (pH = 6.1) was added to the flask. After stabilizing the potential of the glass electrode, the powder sample (0.02 g) was added to the water. Measurements were continued until the pH stabilized and the system reached equilibrium. Data was collected every 10 seconds for the first minute, every minute for the next 10 minutes, and then every 5 minutes. During the measurement, hydration occurs on the surface of the oxide nanopowder when the surface active sites interact with water vapor. The pH change within the first minute allows the type of active centers dominating the air-dried surface of the nanopowder to be determined, thereby determining the properties of the surface to be tested. Further changes in the pH of the suspension over time indicate the water saturation state of the powder in the suspension. If the pH of the suspension increases relative to the pH of distilled water (neutral level), the medium is alkaline; if the pH of the suspension decreases relative to the pH of distilled water (neutral level), the medium is acidic.

[0078] In one embodiment, the average particle size of the ZrO2-8 mol% Y2O3 nanopowder obtained by co-precipitation technique, based on TEM and XRD data, is 6 nm to 50 nm, preferably 8 ± 2 nm (Fig. 1a, Fig. 1b). The nanopowder is represented as a cubic phase Fm3m. The observed X-ray reflectance is consistent with ICDD standard card number 01-071-4810.

[0079] Fig. 1 shows the X-ray diffraction pattern (Fig. 1a), transmission electron microscope image (Fig. 1b), and scanning electron microscope image (Fig. 1c) of the 8YSZ nanopowder and the compressed converter material.

[0080] In one embodiment, the converter of the present invention has different dimensions, depending on the feasibility of the manufacturing process and the structural strength of the converter. For example, cylindrical particles with a diameter of 15 mm and a height of 1 mm, rectangular samples with dimensions of 50 mm, 80 mm, and 2 mm, etc. (Figure 2).

[0081] Figure 2a shows the converter design, and Figure 2b shows the converter circuit diagram.

[0082] In one embodiment, a functional phosphate layer is deposited onto one side of the converter by casting or other methods.

[0083] An inert graphite electrode is deposited on one surface of the converter.A gold-plated current collector connects the converter to the measuring device – DMM7510 (Keithley, USA) (Figure 3). An AM2302 digital capacitive sensor with an accuracy of 0.1% RH controls the humidity level in the room. The test setup is located in a grounded Faraday network.

[0084] Figure 3 shows a schematic diagram of the test scheme and converter of the present invention.

[0085] The technical advantage of the converter of the present invention is that it can continuously convert water vapor (preferably ambient humidity) into electrical energy and has the specific characteristics of an adsorption-type electrical energy converter.

[0086] Figure 4 shows the change of output voltage over time of the 8YSZ converter with and without the functional layer during continuous power generation in a compartment with a humidity level of 60% RH.

[0087] In one embodiment, the potential generated by the converter of the present invention is non-linearly related to the ambient humidity level when the humidity changes from 20% to 95%.

[0088] Figure 5 shows the change of output voltage (open circuit and 100 Ohm load) of the 8YSZ converter with the phosphate functional layer over time.

[0089] Figure 6 shows the change of converter output voltage over time obtained from α-modified alumina (Figure 6a) and γ-modified alumina (Figure 6b), titanium oxide (Figure 6c), and nickel-doped zirconium oxide (Figure 6d) at ambient humidity levels.

[0090] Figure 7 shows a schematic diagram of the potential generated on both sides of the converter under a humidity gradient.

[0091] Table 2 shows the electrical characteristics of humidity-to-electricity converters obtained from different metal oxides.

[0092] Table 2. Electrical characteristics of metal oxide humidity-to-electricity converters

[0093] In one embodiment, an increase in voltage and current can be obtained by connecting multiple converters of the present invention in series, in parallel, or in combination thereof.

[0094] It can be demonstrated that: - When a porous sample made of oxide powder is placed under humid conditions (concentration of water molecules in the air), an electric potential is generated; - The generated electric potential increases over time and then stabilizes at a certain level; - The change in the potential of the converter over time is related to the change in water adsorption of the porous sample over time; - Using a functional layer (phosphate layer) on one side of the converter leads to the active generation of protons because the "aluminum phosphate" on that side dissociates when interacting with adsorbed water molecules, and the sign of the potential can be clearly determined regardless of changes in external conditions. Therefore, continuous power generation can be achieved; - The magnitude of the generated potential depends on the type of material and the properties of the particle surface during the interaction between the particles and water molecules; - Using a functional layer (phosphate layer) on one side of the converter leads to different adsorption characteristics on both sides of the converter, thereby determining the concentration distribution direction of protons and OH- groups along the converter.

[0095] The process of generating potential in porous oxide materials is due to the adsorption of water molecules on the surface of porous channels formed between oxide particles and their diffusion through the channels in the direction of decreasing humidity. The adsorption of water molecules on the surface of oxide particles depends on the type and strength of the surface charge. It is well known that a certain amount of dissociated water molecules exist in water, the amount of which depends on the acidity (pH) value. On the walls of the porous channels, a Stern layer and a diffusion layer with specific symbols are formed, preventing dissociated water molecules (protons and OH- groups) of the same symbol from diffusing through the channels. Therefore, only ions of the same symbol can diffuse along the channels, which determines the charge separation process along the sample (along the water molecule concentration gradient) and the potential value on the opposite side of the converter (Figure 7).

[0096] The humidity gradient along the sample causes water molecules to flow in the porous structure. Due to the self-ionization of water, this flow carries uncompensated charge and generates a flow current or potential. Charge accumulates at the inlet and outlet and forms a flow potential at both ends of the channel. Because the walls of the microchannels are charged (positively or negatively), ions with opposite charges (e.g., positive protons or negative OH- groups) in the aqueous solution are attracted to the channel walls and form an electric double layer, thereby preventing further flow of ions with opposite charges. In this case, charge separation occurs, and an electric potential is generated, the sign of which is determined by the sign of the charge on the channel wall surface.

[0097] Figure 7 shows a schematic diagram of the generation of electric potential in porous oxide materials.

[0098] The effect of the generated electric potential can be explained by a capacitor with a variable dielectric constant, which in turn depends on the flow of water molecules along the porous channel. The potential on this capacitor can be calculated as the sum of the flow potential and the standard potential on the capacitor. Wherein, Vsp is the flow potential (Equation 2), q is the charge, d is the plate spacing, is the dielectric constant of the capacitor medium, and S is the capacitor area. Wherein, R is the channel radius, ζ is the electromotive force of the channel wall, is the dielectric constant of the solution, Q is the volumetric flow rate, K is the conductivity of the solution, and L is the length of the channel.

[0099] When water vapor does not permeate into the porous channels, the flow potential and charge of the capacitor are zero. Due to the increased flow rate of water molecules along the humidity gradient of the converter, the value of the flow potential also increases. The continuous adsorption of water molecules on the wetter side of the converter and their continuous evaporation on the drier side determine the continuous flow of water molecules in the porous channels of the converter.

[0100] The electromotive force and dielectric properties of the material determine the sign and value of the flow potential. In this application, the surface charge of the ZrO2-8mol%Y2O3 powder particles is positive (ΔpH<0). Therefore, OH- groups will move along the porous channels in the ZrO2-8mol%Y2O3-based converter.

[0101] In one embodiment, the specific surface area of ​​the porous structure of the nanopowder-based converter material is several times larger than that of the planar heterojunction, thus significantly improving its conversion efficiency compared to planar analogs in the prior art.

[0102] In one embodiment, the thickness of the converter of the present invention is determined by both the structural strength of the plate and the reduction in potential.

[0103] The above embodiments are combinable.

[0104] References 1. MacGorman, DR & Rust, WD The electrical nature of storms (Oxford University Press, 1998). 2. Faraday, M. Series Experimental Researches in Electricity. Series XVIII. Philosophical Transactions of the Royal Society, Vol. 133, pp. 17-32 (1843). 3. Ducati, TR, Simoes, LH & Galembeck, F. Charge Partitioning at Gas-Solid Interfaces: Humidity Causes Electricity Buildup on Metals. Langmuir, 26, pp. 13763-13766 (2010). 4. Telma R. D. Ducati, Lui's H. Simões, and Fernando Galembeck. Charge Partitioning at Gas-Solid Interfaces: Humidity Causes Electricity Buildup оп Metals / / "Langmuir" 2010, 26(17), pp. 13763-13766. 5. Shen D, Duley WW, Peng P, Xiao M, Feng J, Liu L, Zou G, Zhou YN Specification 9 / 10 Page 12 CN 121693818 A (2020) Moisture‑Enabled Electricity Generation: From Physics and Materials to Self‑Powered Applications. AdvMater 32:2003722. doi:10.1002 / adma.202003722.6. Zhao F, Cheng H, Zhang Z, Jiang L, Qu L (2015) Direct power generation from a graphene oxide film under moisture. 《Adv Mater》27:4351-4357. doi: 10.1002 / adma.201501867. 7. Shen D, Xiao M, Zou G, Liu L, Duley WW, Zhou YN (2018) Self-powered wearable electronics based on moisture enabled electricity generation. 《Adv Mater》30:1705925. 8. Liu X, Gao H, Ward JE, Liu X, Yin B, Fu T, Chen J, Lovley DR, Yao J (2020) Power generation from ambient humidity using protein nanowires. 《Nature》578:550-554 Liu J, Qi Y, Liu D, Dong D, Liu D, Li Z (2019) Moisture-enabled electricity generation from gradient polyoxometalates-modified sponge-like graphene oxide monolith. 《J Mater Sci》54:4831-4841. 9. Shao, C.; Ji, B.; Xu, T.; Gao, J.; Gao, X.; Xiao, Y.; Zhao, Y.; Chen, N.; Jiang, L.; Qu, L. Large-Scale Production of Flexible, High-Voltage Hydroelectric Films Based on Solid Oxides. 《ACS Applied Materials & Interfaces》2019, 11, 30927-30935.10. Yaxin Huang, Huhu Cheng, Ce Yang, Panpan Zhang, Qihua Liao, Houze Yao, Gaoquan Shi, Liangti Qu. Interface‑mediated hygroelectric generator with an output voltage approaching 1.5 volts "Nature Communications‌" (2018) 9:4166 10.1038 / s41467‑018‑06633‑z). 11. Xiaoye Zhao, Jiayun Feng, Ming Xiao, Daozhi Shen, Caiwang Tan, Xiaoguo Song, Jicai Feng, Walter W. Duley, and Y. Norman Zhou A Simple High Power, Fast Response Streaming Potential / Current‑Based Electric Nanogenerator Using a Layer of Al2O3 Nanoparticles, "ACS Applied Materials and Interfaces" 2021, 13, 27169-27178. 12. VV Styrov, SV Simchenko Chemo-EMF generation in nanoscale structures with p-junctions based on SiC / / Report of the National Academy of Sciences of Ukraine, 2013, Vol. 5, pp. 80-86. 13. Doroshkevich AS, Lyubchyk AI, Islamov AK, Turchenko VA, Zelenyak TY, Shylo AV, Balasoiu M, Saprykina AV et al. (2017) Nonequilibrium chemo-electronic conversion of water on the nanosized YSZ: experiment and Molecular Dynamics modelling problem formulation. JPhys ConfSer 848:012021 or patent WO 2021 / 107909 A1.14. Konstantinova TE, Danilenko IA, Glazunova VA, Volkova GK, Gorban OA / / Journal of Nanoparticle Research. 2011. Vol. 13. No. 9. pp. 4015–4023. 15. Kostiuchenko Z, Cui J, Lemay S (2020) Electrochemistry in Micro- and Nanochannels Controlled by Streaming Potentials. J Phys Chem C 124:2656–2663. doi:10.1021 / acs.jpcc.9b08584. Instruction manual, page 10 / 10, 13 CN 121693818 A, Figure 1; Instruction manual, Figure 1 / 8, page 14 CN 121693818 A, Figure 2a, Figure 2b, Figure 2c; Instruction manual, Figure 2 / 8, page 15 CN 121693818 A, Figure 3; Instruction manual, Figure 3 / 8, page 16 CN 121693818 A, Figure 4; Instruction manual, Figure 4 / 8, page 17 CN 121693818 A, Figure 5; Instruction manual, Figure 5 / 8, page 18 CN 121693818 A, Figure 6a, Figure 6b; Instruction manual, Figure 6 / 8, page 19 CN 121693818 A, Figure 6c, Figure 6d; Instruction manual, Figure 7 / 8, page 20 CN 121693818 A, Figure 7; Instruction manual, Figure 8 / 8, page 21 CN 121693818 A.

Claims

1. A modular converter for the continuous conversion of water vapor into electrical energy, comprising: a porous substrate comprising a compressed metal oxide nanopowder; a functional layer for inducing a concentration gradient of protons and OH" in the substrate; a carbon electrode layer; a metal electrode layer for providing a Schottky electrode.

2. The converter according to the preceding claim, further comprising a metal current collector or a carbon current collector.

3. The converter according to the preceding claim, wherein the converter comprises: a porous substrate comprising a yttria stabilized zirconia nanopowder; a functional layer on a first surface of the porous substrate for inducing a concentration gradient of protons and OH" in the substrate; a carbon electrode layer on the functional layer; a metal current collector or a carbon current collector on a first surface of the converter; a metal electrode layer on a second surface of the converter for providing a Schottky electrode, wherein the metal electrode is selected from the group consisting of Au, Ag, Al, Cu, Fe, Zn, Mg, Li, Ni, Co, Ti, Zr, Sn, Cr, Y, Nb, Mo, Pd, Pt, Cd, Hf, Ta, W, C or alloys thereof; a metal current collector or a carbon current collector on a second surface of the converter.

4. The converter according to the preceding claim, wherein the second surface of the converter is directly opposite to the first surface of the converter.

5. The converter according to any one of the preceding claims, wherein the porous substrate further comprises an additive, preferably the additive is 1-20 wt% of activated carbon.

6. The converter according to any one of the preceding claims, wherein the functional layer is a phosphate layer, preferably an aluminum phosphate layer.

7. The converter according to any one of the preceding claims, wherein the carbon electrode layer is preferably a graphite layer.

8. The converter according to any one of the preceding claims, wherein the porous substrate comprises porous channels arranged perpendicular to the electrode layer.

9. The converter according to any one of the preceding claims, wherein the compressed metal oxide nanopowder is selected from the group consisting of aluminum oxide, magnesium oxide, nickel oxide, iron oxide, calcium oxide, titanium dioxide, zirconium oxide, preferably a zirconium oxide based metal oxide, more preferably yttria stabilized zirconia.

10. The converter according to any one of the preceding claims, wherein the compressed metal oxide nanopowder comprises 0 mol% to 20 mol%, preferably 0 mol% to 10 mol%, even more preferably 8 mol% of compressed yttria stabilized zirconia nanopowder.

11. The converter according to any one of the preceding claims, wherein the aluminum phosphate layer has a thickness of 0.001 mm to 5 mm, preferably 0.02 mm to 0.2 mm, even more preferably 0.05 mm.

12. The transducer according to any one of the preceding claims, wherein the porous matrix has a density comprised between 1 g / cm3 3 and 4 g / cm3 3 , preferably between 2.00 g / cm3 3 and 3.5 g / cm3 3 , even more preferably 2.5 g / cm3 3 .

13. The converter according to claim 2 or claim 2 and any one of claims 3-12, wherein the current collector is a gold current collector or a gold plated current collector.

14. The converter according to any of the preceding claims, wherein the converter is cylindrical, cuboid or square.

15. Converter according to the preceding claim, wherein the converter has at least one surface, the surface area of which is 1 cm 2 to 1000 cm 2 , preferably 3 cm 2 to 100 cm 2 , more preferably 11.3 cm 2 .

16. A building article comprising the converter according to any of the preceding claims 1-15, wherein the article is a building cladding article, a building roof article or a building tile article.

17. Use of the converter according to any of the preceding claims 1-15 as a building article, wherein the article is a building cladding article, a building roof article or a building tile article.

18. A device for the continuous conversion of water vapour into electrical energy comprising at least two converters according to any of the preceding claims 1-15, wherein the converters are connected in series, in parallel or a combination thereof.

19. A method for the continuous conversion of water vapour into electrical energy using the converter according to any of the preceding claims 1-15 or the device according to claim 18, comprising the steps of: - placing the converter or the device in a humid environment, preferably with a relative humidity of at least 20%.

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