Electrochemical device, preparation method thereof and power generation equipment

Abstract

The invention discloses an electrochemical device, a preparation method thereof and power generation equipment, and the electrochemical device comprises a substrate which is provided with a bearing surface; an electrolyte solution is stored in the container; the first electrode is arranged on the bearing surface, and at least part of the first electrode is immersed in the electrolyte solution in the container; the second electrode is arranged on the bearing surface, and the second electrode is not in direct contact with the electrolyte solution in the container; the functional layer is arranged on the bearing surface, the functional layer is made of a porous material with capillary channels, the functional layer is in contact with the first electrode and the second electrode respectively, and at least part of the functional layer is immersed in the electrolyte solution in the container. According to the electrochemical device, the preparation method thereof and the power generation equipment provided by the invention, environment heat energy absorbed in a capillary water evaporation process is collected and converted into mechanical energy of the electrolyte aqueous solution, and anions and cations in the electrolyte aqueous solution are asymmetrically transported in the functional layer by utilizing an electrokinetic effect, so that net current and electrokinetic potential are generated.

Description

Technical Field

[0001] This invention relates to the field of fluid power generation technology, and in particular to an electrochemical device and its preparation method, as well as a power generation equipment. Background Technology

[0002] In the context of global climate change and carbon neutrality, the demand for clean, efficient, and low-carbon renewable energy is growing. Although solar, wind, and hydropower have been widely used in various regions, they have limitations in time and space. For example, solar power generation is limited to areas with abundant sunshine, mainly during the day, and its diurnal power generation fluctuates greatly; wind power generation requires areas with stable wind speeds; and hydropower generation requires rivers with sufficient flow velocity and drop.

[0003] In recent years, inspired by bio-electric mechanisms such as those of electric eels, technologies that utilize electrokinetic effects to harvest energy from the environment have gradually gained attention. Among these, reverse electrodialysis power generation (salinity gradient power generation) involves inserting ion-selective membranes between salt solutions of varying concentrations, utilizing transmembrane ion transport caused by concentration diffusion to generate electricity. Furthermore, nanofluidic generators generate electricity through electrokinetic effects, utilizing the internal current generated when a salt solution of a single concentration flows through capillary channels under mechanical pressure.

[0004] However, these technologies all have their limitations. Reverse electrodialysis power generation requires a large amount of freshwater resources to establish a salt concentration gradient; while nanofluid generators require stable and continuous mechanical pressure drive, which is difficult to achieve in practical applications.

[0005] Therefore, it is necessary to provide a new electrochemical device and its preparation method, as well as a power generation device, to address the problems in the existing technology.

[0006] The information disclosed in this background section is intended only to enhance the understanding of the overall background of the invention and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0007] The purpose of this invention is to provide an electrochemical device and its preparation method, as well as a power generation device, which can collect the environmental heat energy absorbed during the capillary water evaporation process and convert it into the mechanical energy of the electrolyte solution to achieve nanofluid power generation.

[0008] To achieve the above objectives, the technical solution provided by this invention is as follows:

[0009] In a first aspect, the present invention provides an electrochemical device comprising:

[0010] The substrate has a bearing surface;

[0011] A container containing an electrolyte solution;

[0012] A first electrode is disposed on the bearing surface, and the first electrode is at least partially immersed in the electrolyte solution in the container. The first electrode is capable of undergoing a reversible redox reaction with the electrolyte solution.

[0013] The second electrode is disposed on the bearing surface. The second electrode does not directly contact the electrolyte solution in the container. The second electrode is capable of undergoing a reversible redox reaction with the electrolyte solution.

[0014] A functional layer is disposed on the bearing surface. The functional layer is formed of a porous material with capillary channels. The functional layer is in contact with the first electrode and the second electrode respectively to form a channel between the first electrode and the second electrode for the electrolyte solution to flow through. The functional layer is at least partially immersed in the electrolyte solution in the container.

[0015] In one or more embodiments of the present invention, the first electrode and the second electrode are formed by a composite of a conductive metal and a sparingly soluble salt of the conductive metal.

[0016] In one or more embodiments of the present invention, the first electrode and the second electrode are formed by a composite of metallic silver and silver chloride.

[0017] In one or more embodiments of the present invention, the electrolyte solution is an aqueous solution of at least one of potassium iodide and sodium iodide.

[0018] In one or more embodiments of the present invention, the average pore size of the capillary channels in the functional layer is less than 200 nm, and the porosity of the functional layer is greater than 10%.

[0019] In a second aspect, the present invention provides a method for preparing an electrochemical device, comprising:

[0020] Silver paste is applied to a substrate and sintered at 120–150°C for 20–40 min to form a silver electrode attached to the substrate.

[0021] The substrate with silver electrodes attached is placed in a slurry containing porous material and immersed for 2 to 5 seconds. The substrate is then removed and sintered at 120 to 150°C for 1 to 3 hours to form a functional layer attached to the substrate.

[0022] The first and second electrodes were immersed in hydrochloric acid solution, and the silver electrode was converted into a silver / silver chloride composite electrode by anodic corrosion. The silver / silver chloride composite electrode was then divided into a first electrode and a second electrode that were electrically isolated from each other.

[0023] The electrochemical device is obtained by inserting a substrate with a first electrode and a second electrode attached to it into a container containing an electrolyte solution, with the first electrode at least partially submerged in the electrolyte solution in the container and the second electrode located above the surface of the electrolyte solution in the container.

[0024] In one or more embodiments of the present invention, silver paste is coated onto a substrate and sintered at 120–150°C for 20–40 min to form a silver electrode attached to the substrate, comprising:

[0025] The substrate was placed in the cleaning solution and soaked for 30 minutes. Then it was sonicated with deionized water for 15 minutes and then dried.

[0026] A PET film is attached to the surface of the dried substrate. The PET film at both ends of the substrate is cut to expose the surface area at both ends of the substrate, forming a PET mask.

[0027] A silver paste containing nano-silver particles and micro-silver particles is coated onto a substrate, and the PET mask is removed. The substrate is then sintered at 120–150°C for 20–40 minutes to form a silver electrode attached to the substrate.

[0028] In one or more embodiments of the present invention, the raw material composition of the slurry containing porous material includes: nano-silica particles, silicic acid, ethanol and terpineol.

[0029] In one or more embodiments of the present invention, the slurry containing porous material is prepared by the following method:

[0030] Prepare a sodium silicate solution and use a cation exchange resin to perform ion exchange to obtain a silicate stock solution with a pH value of 2.0 to 2.5;

[0031] The silica stock solution is dispersed in anhydrous ethanol to prepare an ethanol solution of silica, wherein the volume ratio of the silica stock solution to anhydrous ethanol is 4:100.

[0032] The slurry containing the porous material is prepared by uniformly mixing silica nanoparticles with an ethanol solution of silicic acid and terpineol.

[0033] Thirdly, the present invention provides a power generation device comprising the electrochemical apparatus as described above.

[0034] Compared with existing technologies, the electrochemical device, its preparation method, and power generation equipment provided by this invention convert the environmental heat energy absorbed during capillary water evaporation into the mechanical energy of the electrolyte aqueous solution. Utilizing the electrokinetic effect, it enables asymmetric transport of anions and cations in the electrolyte solution within the functional layer, thereby generating net current and electrokinetic potential. The entire power generation process is green, environmentally friendly, and sustainable, representing a novel renewable energy source. Furthermore, compared with traditional reverse electrodialysis power generation technology, this invention can directly utilize seawater for power generation, eliminating the need to consume precious freshwater resources. Moreover, it can simultaneously separate salt and water for seawater desalination. Additionally, compared with common nanofluidic power generation technologies, this invention effectively utilizes environmental heat energy to convert it into the mechanical energy of the solution, and can operate under any natural environment that allows for solution evaporation, demonstrating strong practicality. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the structure of an electrochemical device in one embodiment;

[0036] Figure 2 This is a cross-sectional view of the glass substrate with silver / silver chloride electrodes and functional layers attached in Example 1;

[0037] Figure 3 This is a SEM image of the functional layer in Example 1;

[0038] Figure 4 The short-circuit current curve of the electrochemical device prepared in Example 1 is shown.

[0039] Figure 5 This is an open-circuit voltage curve of the electrochemical device prepared in Example 1;

[0040] Figure 6 The graph shows the voltage and current variations of the electrochemical device prepared in Example 1 as a function of load.

[0041] Figure 7 The graph shows the output power of the electrochemical device prepared in Example 1 as a function of load.

[0042] Figure 8 The diagram shows the open-circuit voltage and short-circuit current of the electrochemical device under different concentrations of potassium chloride solution.

[0043] Figure 9 A comparison graph showing the output power of the electrochemical devices prepared in each embodiment and comparative example. Detailed Implementation

[0044] The specific embodiments of the present invention will be described in detail below with reference to the examples, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments.

[0045] It should be noted that, unless otherwise specified, the "%" indicating quantity in the following description refers to weight. Unless otherwise indicated, all figures used in this specification and claims to indicate feature dimensions, quantities, and physical properties should be understood to be modified by the term "about" in all cases. Therefore, unless stated to the contrary, the numerical parameters listed in the foregoing specification and appended claims are approximations, and those skilled in the art can appropriately modify these approximations to obtain the desired characteristics using the teachings disclosed herein. The use of numerical ranges expressed as endpoints includes all numbers within that range and any range within that range; for example, 1 to 5 includes 1, 1.2, 1.4, 1.55, 2, 2.75, 3, 3.80, 4, and 5, etc.

[0046] It should also be noted that the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus; the term “preferred” refers to a preferred alternative, but is not limited to the chosen alternative.

[0047] In existing technologies, there are two main methods for harvesting energy from the environment using the electrokinetic effect: reverse electrodialysis power generation (salinity gradient power generation) and nanofluidic generators. Both technologies utilize the internal current generated by the salt solution in nanopores to generate electricity, but they both have some limitations. Reverse electrodialysis power generation requires a large amount of freshwater resources to establish a salt concentration gradient; while nanofluidic generators require stable and continuous mechanical pressure to drive them.

[0048] The inventors observed that during the capillary evaporation of water, when the evaporation rate is sufficiently high, after the liquid water molecules at the capillary tip absorb ambient heat and transform into gaseous water molecules, and then leave the solid-liquid interface, the area of ​​the solid-gas interface increases relative to the solid-liquid interface. This means the capillary tip changes from wet to dry, attracting liquid water from the lower end of the capillary back towards the capillary tip. This flow of water inside the capillary caused by the evaporation of liquid water at the capillary tip can convert ambient heat energy into the mechanical energy of the liquid water within the capillary.

[0049] To this end, the inventors combined nanofluid generator technology to create a continuous and stable pressure difference at both ends of the nanopores by utilizing the capillary water evaporation process, and proposed a technical solution to convert environmental thermal energy into the mechanical energy of water in the capillary pores to generate electricity.

[0050] The technical approach of this invention is to utilize a functional layer, a first electrode, and a second electrode to form a closed circuit, allowing the net current generated in the functional layer to flow through the two electrodes and drive a redox reaction. Specifically, the functional layer is a hydrophilic insulating layer formed of a porous material with capillary channels. Capillary action allows the electrolyte (aqueous) solution to rise along the functional layer from bottom to top and evaporate at the upper end. Simultaneously, electrokinetic effects enable asymmetric transport of cations and anions in the electrolyte solution within the functional layer, thereby generating a net current and electrokinetic potential.

[0051] Please refer to Figure 1 As shown, the electrochemical device provided in this embodiment of the invention includes a substrate, a container, and a first electrode ( Figure 1 (Central electrode), Second electrode () Figure 1 (Cathode) and functional layer.

[0052] The substrate has a support surface; an electrolyte solution is stored in a container. A first electrode is disposed on the support surface of the substrate, and the first electrode is at least partially immersed in the electrolyte solution in the container. The first electrode is capable of undergoing a reversible redox reaction with the electrolyte solution. A second electrode is disposed on the support surface of the substrate, and the second electrode is not in direct contact with the electrolyte solution in the container. The second electrode is capable of undergoing a reversible redox reaction with the electrolyte solution. A functional layer is disposed on the support surface. The functional layer is formed of a porous material with capillary channels. The functional layer is in contact with both the first and second electrodes to form a channel between the first and second electrodes for the electrolyte solution to flow through. The functional layer is at least partially immersed in the electrolyte solution in the container.

[0053] The substrate can be used as a support structure for the first electrode, the second electrode, and the functional layer. The substrate can be made of insulating materials such as glass, ceramics, and plastics.

[0054] The first electrode is an electrode capable of undergoing a reversible redox reaction with the electrolyte solution. It is disposed on the substrate bearing surface and at least partially immersed in the electrolyte solution within the container. The function of the first electrode is to provide an endpoint for contacting the functional layer and undergoing a redox reaction with the electrolyte solution, and to provide a start or end point for the subsequent net current.

[0055] The second electrode is an electrode capable of undergoing a reversible redox reaction with the electrolyte solution. It is disposed on the substrate's bearing surface and does not directly contact the electrolyte solution within the container. The second electrode can be made of the same or different materials as the first electrode. The function of the second electrode is to provide another endpoint for contacting the functional layer and undergoing a redox reaction with the electrolyte solution, as well as to provide another start or end point for the subsequent net current.

[0056] The electrical signal of the electrochemical device provided by this invention originates from the symmetrical redox reactions on the first and second electrodes. If the redox reactions of the first and second electrodes in the electrolyte solution are irreversible, meaning that after oxidation or reduction, they cannot return to their original state, the redox electrodes will lose their oxidizing or reducing properties and will be unable to continue participating in electron transfer, thus causing the electrochemical device to malfunction.

[0057] The functional layer is a hydrophilic insulating layer formed of a porous material with capillary channels. It is disposed on the bearing surface of the substrate and contacts the first and second electrodes, respectively. The functional layer can be made of various materials, such as polymers, ceramics, and oxides. The capillary channels in the functional layer allow the electrolyte solution to rise along the functional layer from bottom to top using capillary action and evaporate at the upper end. The capillary channels can also utilize the electrokinetic effect to cause asymmetric transport of anions and cations in the electrolyte solution within the functional layer, thereby generating net current and electrokinetic potential, realizing the conversion of mechanical energy into electrical energy.

[0058] It should be noted that when the capillary surface is positively charged, cations in the electrolyte solution are repelled, while anions are allowed to pass through. Excess anions accumulate at the upper end of the functional layer (the evaporation end, which is not in direct contact with the electrolyte solution), and excess cations accumulate at the lower end of the functional layer (the end immersed in the electrolyte solution). If the capillary surface is negatively charged, the ion selectivity is the opposite.

[0059] When the surface of the nanopores is positively charged, the excess anions at the upper end of the capillary channel undergo an oxidation reaction with the second electrode, making the second electrode the anode; conversely, the excess cations at the lower end of the capillary channel undergo a reduction reaction with the first electrode, making the first electrode the cathode. If the surface of the capillary channel is negatively charged, the redox reactions of the electrodes are the opposite of those described above.

[0060] As the electrolyte solution evaporates at the top of the functional layer, the electrolyte crystallizes and precipitates there, allowing for electrolyte recovery. Furthermore, the electrolyte crystallization at the top of the functional layer attracts lower concentration electrolyte solutions to permeate upwards, promoting the transport of capillary nanofluids and contributing to improved power generation performance.

[0061] In one exemplary embodiment, the first electrode and the second electrode are formed by a composite of a conductive metal and a sparingly soluble salt of the conductive metal (sparingly soluble in water). The electrode formed by the composite of a conductive metal and a sparingly soluble salt of the conductive metal has the characteristic of being able to undergo a reversible redox reaction in the electrolyte solution. Preferably, the first electrode and the second electrode are formed by a composite of metallic silver and silver chloride.

[0062] In one exemplary embodiment, the electrolyte solution is an aqueous solution of at least one of potassium iodide and sodium iodide.

[0063] It is important to note that the ion selectivity of capillary channels is the key factor determining whether certain ions can pass through while others are blocked. This selectivity exists primarily because different types of anions and cations bind to different numbers of water molecules, resulting in variations in their effective mass during migration. For example, for the same cation, it will bind to more water molecules with larger anions than with smaller anions.

[0064] When there is a difference in the transport numbers of cations and anions, this difference can affect the efficiency of electrochemical processes. In particular, if one ion (e.g., potassium ion) migrates faster, it may accumulate near the electrode, thereby enhancing the electric field and driving another ion (e.g., iodide ion) to migrate faster. This enhanced electric field caused by the migration difference can significantly increase the power output of an electrochemical device.

[0065] Potassium iodide (KI) and sodium iodide (NaI) exhibit relatively large differences in the migration of cations (potassium ions, sodium ions) and anions (iodide ions). This difference can enhance the selectivity and migration rate of ions in capillary channels, thereby increasing the power generation capacity of the device. In other words, potassium iodide and sodium iodide have better power generation performance compared to other possible electrolytes.

[0066] In one exemplary embodiment, the average pore size of the capillary channels in the functional layer is less than 200 nm, and the porosity of the functional layer is greater than 10%.

[0067] One embodiment of the present invention also provides a method for preparing the aforementioned electrochemical device, the method specifically including the following steps:

[0068] S201: Apply silver paste to the substrate and sinter at 120-150°C for 20-40 minutes to form a silver electrode attached to the substrate.

[0069] It should be noted that silver paste is a mixture containing silver powder and organic binder. It can be applied to a substrate using methods such as coating, spraying, or printing to form a uniform thin film. Then, the silver powder particles are fused together through sintering to form a continuous conductive layer. The substrate material can be ceramic, glass, metal, plastic, etc., but the main requirements are sufficient mechanical strength and heat resistance, as well as good adhesion to the silver paste. Sintering within a temperature range of 120 to 150°C ensures that the silver particles in the silver paste fuse to form a continuous metal film while preventing heat damage to the substrate.

[0070] The main components of silver paste are silver powder, organic binder, and solvent. The content, size, shape, and distribution of the silver powder all affect its performance. For example, silver powder with a silver content of 60-70%, a particle size of 0.5-5 μm, a subspherical shape, and uniform distribution can be selected because such silver powder provides high conductivity, low resistivity, and good coatability and sinterability. The role of the organic binder is to disperse the silver powder in the organic solvent and to form a thin film on the substrate. The selection of the organic binder must consider its solubility in silver powder, its adhesion to the substrate, and its impact on sintering. For example, ethyl acetate can be chosen as the organic solvent because it has a low boiling point and saturated vapor pressure, allowing it to evaporate quickly before sintering and reducing organic residue. Acrylic resin can be chosen as the organic resin because it has good viscosity and cohesiveness, enabling the silver powder to form a uniform thin film on the substrate, and it can decompose into inorganic substances during sintering without affecting the bonding of the silver powder.

[0071] In one exemplary embodiment, silver paste is coated onto a substrate and sintered at 120–150°C for 20–40 minutes to form a silver electrode attached to the substrate. Specifically, this includes: immersing the substrate in a cleaning solution for 30 minutes, ultrasonicating it with deionized water for 15 minutes, and then drying the substrate; attaching a PET film to the surface of the dried substrate, cutting the PET film at both ends adjacent to the substrate to expose the surface areas at both ends of the substrate, forming a PET mask; coating the substrate with silver paste containing nano-silver particles and micro-silver particles, removing the PET mask, and sintering at 120–150°C for 20–40 minutes to form a silver electrode attached to the substrate.

[0072] It should be noted that different cleaning solutions can be selected depending on the substrate material to improve the substrate's adhesion. For example, a sodium hydroxide solution at 90°C can be used to clean glass substrates.

[0073] S202: The substrate with the silver electrode attached is placed in a slurry containing porous material and immersed for 2 to 5 seconds. The substrate is then removed and sintered at 120 to 150°C for 1 to 3 hours to form a functional layer attached to the substrate.

[0074] In one exemplary embodiment, the raw material composition of the slurry containing porous material includes: nano-silica particles, silicic acid, ethanol, and terpineol. The slurry containing porous material is prepared in the following manner:

[0075] A sodium silicate solution was prepared, and a silicic acid stock solution with a pH value of 2.0 to 2.5 was obtained by ion exchange using a cation exchange resin. The silicic acid stock solution was dispersed in anhydrous ethanol to obtain an ethanol solution of silicic acid, wherein the volume ratio of the silicic acid stock solution to anhydrous ethanol was 4:100. Silica nanoparticles were mixed evenly with the ethanol solution of silicic acid and terpineol to obtain the slurry containing the porous material.

[0076] S203: The first electrode and the second electrode are immersed in hydrochloric acid solution, and the silver electrode is converted into a silver / silver chloride composite electrode by anodic corrosion. The silver / silver chloride composite electrode is then divided into a first electrode and a second electrode that are electrically isolated from each other.

[0077] It should be noted that immersing the silver electrode in a hydrochloric acid solution allows the strong acid to react with the silver on the electrode surface, forming silver chloride. Anodizing is then used to induce this reaction on the silver electrode surface within the hydrochloric acid solution. Anodizing is a current-driven chemical etching process in which the silver electrode acts as the anode, reacting with chloride ions in the solution to form silver chloride. After anodizing, the silver / silver chloride composite electrode needs to be divided into two isolated electrodes. This is necessary for the functionality of the subsequent device, ensuring that the two electrodes can operate independently. This is typically achieved through physical cutting or laser etching.

[0078] S204: Insert a substrate with a first electrode and a second electrode attached into a container containing an electrolyte solution, and at least partially immerse the first electrode in the electrolyte solution in the container, with the second electrode located above the surface of the electrolyte solution in the container, thereby obtaining the electrochemical device.

[0079] The specific power generation process of the electrochemical device provided by this invention is as follows:

[0080] Under the capillary action of the functional layer, the electrolyte solution will rise along the capillary channels of the hydrophilic functional layer until the solution contacts the second electrode. Under suitable humidity conditions, the electrolyte solution at the upper end of the functional layer will continue to evaporate, while the solution at the lower end will continue to rise to the vicinity of the second electrode and evaporate.

[0081] In a continuously ascending electrolyte solution within capillary channels, the electrokinetic effect of the capillary channels causes separation of cations and anions. When the capillary channel surface is positively charged, cations in the electrolyte solution are repelled, while anions are allowed to pass through, resulting in an excess of anions accumulating at the upper end of the functional layer and an excess of cations accumulating at the lower end. If the nanopore surface is negatively charged, the ion selectivity is reversed.

[0082] When the capillary surface is positively charged, excess anions at the upper end of the functional layer react with the second electrode to form the positive electrode of the battery, while excess cations at the lower end of the functional layer react with the first electrode to form the negative electrode of the battery. If the capillary surface is negatively charged, the redox reaction of the electrode is the opposite of the above.

[0083] The electrolyte solution evaporates at the top of the functional layer, and the corresponding electrolyte crystallizes and precipitates at the top of the functional layer. In addition, the evaporated fresh water can be collected by an external condenser, thus achieving seawater desalination while generating electricity.

[0084] One embodiment of the present invention also provides a power generation device, which includes the electrochemical device as described above.

[0085] The present invention will be further described below with reference to specific embodiments.

[0086] Example 1

[0087] The glass substrate was immersed in a 5% sodium hydroxide solution at 90°C for 30 minutes, followed by sonication with deionized water for 15 minutes, and then dried. A 30μm thick PET film was then attached to the surface of the dried glass substrate. The PET film adjacent to both ends of the glass substrate was cut to expose the surface areas at both ends, forming a PET mask. Silver paste containing nano-silver particles and micro-silver particles (Suzhou Inna Electronic Materials Co., Ltd., Metal Mesh silver paste) was coated onto the glass substrate, and the PET mask was removed. The substrate was then sintered at 130°C for 20–40 minutes to form a silver electrode attached to the glass substrate.

[0088] A glass substrate with attached silver electrodes was immersed in a slurry containing porous material for 3 seconds. The substrate was then removed and sintered at 130°C for 2 hours to form a functional layer attached to the glass substrate. The slurry containing porous material was prepared as follows: a 187.5 mg / mL sodium silicate solution was prepared, and ion exchange with a cation exchange resin was used to obtain a silicate stock solution with a pH of 2.0–2.5. The silicate stock solution was dispersed in anhydrous ethanol to obtain an ethanol solution of silicate, with a volume ratio of silicate stock solution to anhydrous ethanol of 4:100. 10 g of silica nanoparticles were mixed evenly with 7 mL of the ethanol solution of silicate and 2 mL of terpineol, and then ultrasonically dispersed in an ice bath for 2 minutes to obtain the slurry containing porous material.

[0089] The functional layer on the surface of the glass substrate, specifically the area around the electrode leads, is scraped off to expose the electrode leads. Excess functional layer on the back and sides of the glass substrate is also scraped off. The area below the silver electrode leads on the glass substrate is immersed in 0.38% dilute hydrochloric acid, and the silver electrode is converted to a silver / silver chloride electrode using anodizing. The current density for anodizing is controlled at 3 mA / cm². 2 The etching time is 2 minutes, followed by rinsing with deionized water to remove residual hydrochloric acid. Then, the silver / silver chloride composite electrode is divided into a first electrode and a second electrode that are electrically isolated from each other.

[0090] The substrate with the first and second electrodes attached is inserted into a container containing a potassium chloride solution (concentration of 1 mol / L), with the first electrode at least partially immersed in the potassium chloride solution in the container, and the second electrode located above the surface of the potassium chloride solution in the container. The pins of the first and second electrodes are then led out through conductive clamps.

[0091] Example 2

[0092] The glass substrate was immersed in a 5% sodium hydroxide solution at 90°C for 30 minutes, followed by sonication with deionized water for 15 minutes, and then dried. A 30μm thick PET film was then attached to the surface of the dried glass substrate. The PET film adjacent to both ends of the glass substrate was cut to expose the surface areas at both ends, forming a PET mask. Silver paste containing nano-silver particles and micro-silver particles (Suzhou Inna Electronic Materials Co., Ltd., Metal Mesh silver paste) was coated onto the glass substrate, and the PET mask was removed. The substrate was then sintered at 130°C for 20–40 minutes to form a silver electrode attached to the glass substrate.

[0093] A glass substrate with attached silver electrodes was immersed in a slurry containing porous material for 3 seconds. The substrate was then removed and sintered at 130°C for 2 hours to form a functional layer attached to the glass substrate. The slurry containing porous material was prepared as follows: a 187.5 mg / mL sodium silicate solution was prepared, and ion exchange with a cation exchange resin was used to obtain a silicate stock solution with a pH of 2.0–2.5. The silicate stock solution was dispersed in anhydrous ethanol to obtain an ethanol solution of silicate, with a volume ratio of silicate stock solution to anhydrous ethanol of 4:100. 10 g of silica nanoparticles were mixed evenly with 7 mL of the ethanol solution of silicate and 2 mL of terpineol, and then ultrasonically dispersed in an ice bath for 2 minutes to obtain the slurry containing porous material.

[0094] The functional layer on the surface of the glass substrate, specifically the area around the electrode leads, is scraped off to expose the electrode leads. Excess functional layer on the back and sides of the glass substrate is also scraped off. The area below the silver electrode leads on the glass substrate is immersed in 0.38% dilute hydrochloric acid, and the silver electrode is converted to a silver / silver chloride electrode using anodizing. The current density for anodizing is controlled at 3 mA / cm². 2 The etching time is 2 minutes, followed by rinsing with deionized water to remove residual hydrochloric acid. Then, the silver / silver chloride composite electrode is divided into a first electrode and a second electrode that are electrically isolated from each other.

[0095] The substrate with the first and second electrodes attached is inserted into a container containing a potassium bromide solution (concentration of 1 mol / L), with the first electrode at least partially immersed in the potassium bromide solution in the container, and the second electrode located above the surface of the potassium bromide solution in the container. The leads of the first and second electrodes are then brought out through conductive clamps.

[0096] Example 3

[0097] The glass substrate was immersed in a 5% sodium hydroxide solution at 90°C for 30 minutes, followed by sonication with deionized water for 15 minutes, and then dried. A 30μm thick PET film was then attached to the surface of the dried glass substrate. The PET film adjacent to both ends of the glass substrate was cut to expose the surface areas at both ends, forming a PET mask. Silver paste containing nano-silver particles and micro-silver particles (Suzhou Inna Electronic Materials Co., Ltd., Metal Mesh silver paste) was coated onto the glass substrate, and the PET mask was removed. The substrate was then sintered at 130°C for 20–40 minutes to form a silver electrode attached to the glass substrate.

[0098] A glass substrate with attached silver electrodes was immersed in a slurry containing porous material for 3 seconds. The substrate was then removed and sintered at 130°C for 2 hours to form a functional layer attached to the glass substrate. The slurry containing porous material was prepared as follows: a 187.5 mg / mL sodium silicate solution was prepared, and ion exchange with a cation exchange resin was used to obtain a silicate stock solution with a pH of 2.0–2.5. The silicate stock solution was dispersed in anhydrous ethanol to obtain an ethanol solution of silicate, with a volume ratio of silicate stock solution to anhydrous ethanol of 4:100. 10 g of silica nanoparticles were mixed evenly with 7 mL of the ethanol solution of silicate and 2 mL of terpineol, and then ultrasonically dispersed in an ice bath for 2 minutes to obtain the slurry containing porous material.

[0099] The functional layer on the surface of the glass substrate, specifically the area around the electrode leads, is scraped off to expose the electrode leads. Excess functional layer on the back and sides of the glass substrate is also scraped off. The area below the silver electrode leads on the glass substrate is immersed in 0.38% dilute hydrochloric acid, and the silver electrode is converted to a silver / silver chloride electrode using anodizing. The current density for anodizing is controlled at 3 mA / cm². 2 The etching time is 2 minutes, followed by rinsing with deionized water to remove residual hydrochloric acid. Then, the silver / silver chloride composite electrode is divided into a first electrode and a second electrode that are electrically isolated from each other.

[0100] The substrate with the first and second electrodes attached is inserted into a container containing a potassium iodide solution (concentration of 1 mol / L), with the first electrode at least partially immersed in the potassium iodide solution in the container and the second electrode located above the surface of the potassium iodide solution in the container. The leads of the first and second electrodes are then brought out through conductive clamps.

[0101] Comparative Example 1

[0102] The glass substrate was immersed in a 5% sodium hydroxide solution at 90°C for 30 minutes, followed by sonication with deionized water for 15 minutes, and then dried. A 30μm thick PET film was then attached to the surface of the dried glass substrate. The PET film adjacent to both ends of the glass substrate was cut to expose the surface areas at both ends, forming a PET mask. Silver paste containing nano-silver particles and micro-silver particles (Suzhou Inna Electronic Materials Co., Ltd., Metal Mesh silver paste) was coated onto the glass substrate, and the PET mask was removed. The substrate was then sintered at 130°C for 20–40 minutes to form a silver electrode attached to the glass substrate.

[0103] A glass substrate with attached silver electrodes was immersed in a slurry containing porous material for 3 seconds. The substrate was then removed and sintered at 130°C for 2 hours to form a functional layer attached to the glass substrate. The slurry containing porous material was prepared as follows: a 187.5 mg / mL sodium silicate solution was prepared, and ion exchange with a cation exchange resin was used to obtain a silicate stock solution with a pH of 2.0–2.5. The silicate stock solution was dispersed in anhydrous ethanol to obtain an ethanol solution of silicate, with a volume ratio of silicate stock solution to anhydrous ethanol of 4:100. 10 g of silica nanoparticles were mixed evenly with 7 mL of the ethanol solution of silicate and 2 mL of terpineol, and then ultrasonically dispersed in an ice bath for 2 minutes to obtain the slurry containing porous material.

[0104] The functional layer on the surface of the glass substrate, specifically the area around the electrode leads, is scraped off to expose the electrode leads. Excess functional layer on the back and sides of the glass substrate is also scraped off. The area below the silver electrode leads on the glass substrate is immersed in 0.38% dilute hydrochloric acid, and the silver electrode is converted to a silver / silver chloride electrode using anodizing. The current density for anodizing is controlled at 3 mA / cm². 2 The etching time is 2 minutes, followed by rinsing with deionized water to remove residual hydrochloric acid. Then, the silver / silver chloride composite electrode is divided into a first electrode and a second electrode that are electrically isolated from each other.

[0105] A substrate with a first electrode and a second electrode attached is inserted into a container containing pure water, with the first electrode at least partially submerged in the pure water and the second electrode positioned above the surface of the pure water. The leads of the first and second electrodes are then brought out through conductive clamps.

[0106] Figure 1 This is a cross-sectional view of the glass substrate with silver / silver chloride electrodes and functional layers attached in Example 1;

[0107] Figure 2 This is a SEM image of the functional layer in Example 1; Figure 3 The short-circuit current curve of the electrochemical device prepared in Example 1 is shown. Figure 4 This is an open-circuit voltage curve of the electrochemical device prepared in Example 1;

[0108] Figure 5 The graph shows the voltage and current variations of the electrochemical device prepared in Example 1 as a function of load. Figure 6 The graph shows the output power of the electrochemical device prepared in Example 1 as a function of load. Figure 7 The diagram shows the open-circuit voltage and short-circuit current of the electrochemical device under different concentrations of potassium chloride solution. Figure 8 A comparison graph showing the output power of the electrochemical devices prepared in each embodiment and comparative example.

[0109] In summary, the electrochemical device, its preparation method, and the power generation equipment provided by this invention collect the environmental heat energy absorbed during capillary water evaporation and convert it into the mechanical energy of the electrolyte aqueous solution. Utilizing the electrokinetic effect, it enables asymmetric transport of anions and cations in the electrolyte solution within the functional layer, thereby generating net current and electrokinetic potential. The entire power generation process is green, environmentally friendly, and sustainable, representing a novel renewable energy source. Furthermore, compared to traditional reverse electrodialysis power generation technology, this invention can directly utilize seawater for power generation, eliminating the need to consume precious freshwater resources. Moreover, it can simultaneously separate salt and water for seawater desalination. Additionally, compared to common nanofluidic power generation technologies, this invention effectively utilizes environmental heat energy to convert it into the mechanical energy of the solution, and can operate under any natural environment that allows for solution evaporation, demonstrating strong practicality.

[0110] The foregoing description of specific exemplary embodiments of the invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the invention to the precise forms disclosed, and it will be apparent that many changes and variations can be made in accordance with the foregoing teachings. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments of the invention, as well as various different choices and variations. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. An electrochemical device, characterized in that, include: The substrate has a bearing surface; A container containing an electrolyte solution; A first electrode is disposed on the bearing surface, and the first electrode is at least partially immersed in the electrolyte solution in the container. The first electrode is capable of undergoing a reversible redox reaction with the electrolyte solution. The second electrode is disposed on the bearing surface. The second electrode does not directly contact the electrolyte solution in the container. The second electrode is capable of undergoing a reversible redox reaction with the electrolyte solution. A functional layer is disposed on the bearing surface. The functional layer is formed of a porous material with capillary channels. The functional layer is in contact with the first electrode and the second electrode respectively to form a channel between the first electrode and the second electrode for the electrolyte solution to flow through. The functional layer is at least partially immersed in the electrolyte solution in the container.

2. The electrochemical device as described in claim 1, characterized in that, The first electrode and the second electrode are formed by a composite of a conductive metal and a sparingly soluble salt of the conductive metal.

3. The electrochemical device as described in claim 2, characterized in that, The first electrode and the second electrode are formed by a composite of metallic silver and silver chloride.

4. The electrochemical device as described in claim 1, characterized in that, The electrolyte solution is an aqueous solution of at least one of potassium iodide and sodium iodide.

5. The electrochemical device as described in claim 1, characterized in that, The average pore size of the capillary channels in the functional layer is less than 200 nm, and the porosity of the functional layer is greater than 10%.

6. A method for preparing an electrochemical device, characterized in that, include: Silver paste is applied to a substrate and sintered at 120–150°C for 20–40 min to form a silver electrode attached to the substrate. The substrate with silver electrodes attached is placed in a slurry containing porous material and immersed for 2 to 5 seconds. The substrate is then removed and sintered at 120 to 150°C for 1 to 3 hours to form a functional layer attached to the substrate. The first and second electrodes were immersed in hydrochloric acid solution, and the silver electrode was converted into a silver / silver chloride composite electrode by anodic corrosion. The silver / silver chloride composite electrode was then divided into a first electrode and a second electrode that were electrically isolated from each other. The electrochemical device is obtained by inserting a substrate with a first electrode and a second electrode attached to it into a container containing an electrolyte solution, with the first electrode at least partially submerged in the electrolyte solution in the container and the second electrode located above the surface of the electrolyte solution in the container.

7. The method for preparing the electrochemical device as described in claim 6, characterized in that, Silver paste is applied to a substrate and sintered at 120–150°C for 20–40 minutes to form a silver electrode attached to the substrate, comprising: The substrate was placed in the cleaning solution and soaked for 30 minutes. Then it was sonicated with deionized water for 15 minutes and then dried. A PET film is attached to the surface of the dried substrate. The PET film at both ends of the substrate is cut to expose the surface area at both ends of the substrate, forming a PET mask. A silver paste containing nano-silver particles and micro-silver particles is coated onto a substrate, and the PET mask is removed. The substrate is then sintered at 120–150°C for 20–40 minutes to form a silver electrode attached to the substrate.

8. The method for preparing the electrochemical device as described in claim 6, characterized in that, The raw material composition of the slurry containing porous materials includes: nano-silica particles, silicic acid, ethanol, and terpineol.

9. The method for preparing the electrochemical device as described in claim 8, characterized in that, The slurry containing porous material is prepared by the following method: Prepare a sodium silicate solution and use a cation exchange resin to perform ion exchange to obtain a silicate stock solution with a pH value of 2.0 to 2.5; The silica stock solution is dispersed in anhydrous ethanol to prepare an ethanol solution of silica, wherein the volume ratio of the silica stock solution to anhydrous ethanol is 4:

100. The slurry containing the porous material is prepared by uniformly mixing silica nanoparticles with an ethanol solution of silicic acid and terpineol.

10. A power generation device, characterized in that, The electrochemical device includes any one of claims 1 to 5.

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