Cellulose-based hygroscopic evaporation integrated power generation device and its fabrication method

Abstract

This invention discloses a cellulose-based hygroscopic and evaporative integrated power generation device and its fabrication method. The device includes a cellulose hygroscopic layer, a cellulose evaporative layer, and a first electrode and a second electrode disposed on the outer surface of the cellulose layer. The inner surfaces of the hygroscopic and evaporative layers are tightly bonded together, while the outer surfaces are exposed to air. The first and second electrodes are respectively connected to the outer surfaces of the hygroscopic and evaporative layers. When placed in an atmospheric environment, the device absorbs moisture from the air through the cellulose hygroscopic layer and evaporates it into the air through the cellulose evaporative layer. Relying on its own absorption and evaporation of moisture from the air, the device can generate continuous voltage and current. The hygroscopic and evaporative layer materials are inexpensive and readily available, the fabrication method is simple, and it can be mass-produced. This device has a wide range of applications and can sustainably generate high energy output for extended periods in an atmospheric environment, demonstrating significant application potential.

Description

Technical Field

[0001] This invention belongs to the field of new energy power generation equipment, specifically relating to a cellulose-based moisture-absorbing and evaporating integrated power generation device and its preparation method. Background Technology

[0002] Water covers approximately 71% of the Earth's surface, and about 70% of solar energy reaching the Earth's surface is absorbed by water—more than three thousand times the amount of primary energy consumed by humankind. Water exists widely in nature in various forms, including water vapor, rain, snow, and rivers. Researchers have utilized the interaction between water and materials to develop a variety of novel water-based photovoltaic devices, such as water vapor-stimulated power generation devices, droplet and wave-responsive power generation devices, and water evaporation-induced power generation devices. These devices directly convert the energy contained in water and the surrounding environment into electrical energy, which is of great significance for solving future energy crises and ecological environmental problems.

[0003] However, the aforementioned novel hydroelectric devices still face some limitations in their applications. For example, the humidification generator reported by Qu Liangti's team at Tsinghua University, which utilizes an asymmetric structure in graphene oxide to respond to changes in environmental humidity and generate pulsed electrical signals, exhibits a problem in their published paper (Interface-mediated hygroelectric generator with an output voltage approaching 1.5 volts). The generated electrical signal rises rapidly within 2 seconds and gradually decreases to its initial state within approximately 600 seconds (The electrical signal raises up quickly within 2 seconds and gradually descends for about 600 seconds to its initial state with RH evolution (10%–90%–10%), which is consistent with the hydration and dehydration speed of...). (h-GO) cannot meet the requirements of continuous power supply; at the same time, existing water evaporation-induced power generation devices require liquid water to provide the evaporation source, that is, to generate electrical signals in an environment with a relative humidity of 5-95%, and most water vapor-stimulated power generation devices can only generate brief pulsed electrical outputs under humidity change excitation (dry-wet-dry), and the current output is small, which affects the application of such devices.

[0004] Among devices capable of generating continuous electrical signals, protein nanowire moisture-powered devices can produce a voltage of approximately 0.5V, but the current is in the hundreds of nanoamps, lasting for 20 hours. Graphene oxide / PAAS moisture-powered devices produce a voltage of approximately 0.6V, lasting for 120 hours, but the current is less than 1 microamp, lasting for about 12 hours. However, the preparation processes of the protein nanowires and GO / PAAS used in these moisture-powered devices are relatively complex, limiting their large-area, batch production and hindering large-scale application. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a cellulose-based hygroscopic evaporation integrated power generation device and its preparation method. The preparation method of this device is simple, uses low-cost materials, and the prepared device has a wide range of applications and can sustain long-term power output. It can be applied to energy capture and conversion in the atmospheric environment.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] First, this application provides a cellulose-based moisture-absorbing and evaporating integrated power generation device, which includes a first electrode, a cellulose moisture-absorbing layer, a cellulose evaporating layer, and a second electrode. The inner surfaces of the cellulose moisture-absorbing layer and the cellulose evaporating layer are tightly bonded together. The first electrode is connected to the outer surface of the cellulose moisture-absorbing layer, and the second electrode is connected to the outer surface of the cellulose evaporating layer. When exposed to the atmospheric environment, the cellulose moisture-absorbing layer can spontaneously absorb moisture from the air. The moisture is directionally transported from the surface of the cellulose moisture-absorbing layer to the interior and evaporates from the outer surface of the cellulose evaporating layer. Relying on the device's own absorption and evaporation of moisture from the air, it can sustainably generate voltage and current for a long time.

[0008] Preferably, the thickness of the cellulose moisture-absorbing layer is 0.1-3 mm, and the thickness of the cellulose evaporation layer is 0.1-3 mm.

[0009] Preferably, the first electrode and the second electrode are made of conventional inorganic conductive materials (such as conductive polymers) or metallic conductive materials (such as copper, aluminum, silver, etc.) in the art. The materials of the first electrode and the second electrode can be the same or different.

[0010] Secondly, this application also provides a method for preparing the above-mentioned cellulose-based hygroscopic evaporation integrated power generation device, the steps of which are as follows:

[0011] (1) Dissolve or disperse the hygroscopic material in deionized water to prepare a hygroscopic agent with a mass fraction not exceeding 30%, and set aside; disperse the evaporation material in ethanol to prepare a slurry, and set aside; wherein the evaporation material accounts for 10%-40% of the slurry by mass, preferably 31%;

[0012] The moisture-absorbing material includes one of lithium chloride, clay, silica gel, and water-absorbing MOFs;

[0013] The evaporation material includes one of carbon black, ethyl cellulose, and terpineol.

[0014] (2) Cut the cellulose sheets into suitable shapes, clean their surfaces, and then immerse them in the desiccant and evaporation slurry for at least half an hour. Then take them out and dry them (the drying temperature is preferably 70-120℃) to make a cellulose moisture-absorbing layer and a cellulose evaporation layer. Generally speaking, the thickness of the cellulose sheets increases by about 0.1-0.5 mm after immersion. The thickness of the cellulose moisture-absorbing layer and the cellulose evaporation layer after immersion is preferably 0.1-3 mm.

[0015] (3) The cellulose hygroscopic layer and the cellulose evaporation layer are pressed together (preferably at a pressure of 0.5-3 MPa), and the edge portion is sealed with a paraffin film. The electrode material is then connected to the outer surface of the cellulose hygroscopic layer and the cellulose evaporation layer, respectively, to obtain a cellulose-based hygroscopic and evaporation integrated power generation device. Generally, the electrode material can be a conventional inorganic conductive material or a metallic conductive material in the art. If it is carbon paste or carbon glue, it is connected to the cellulose hygroscopic layer or the cellulose evaporation layer by coating or bonding. If it is metal foil, it needs to be fixed by a clamp after physical pressing.

[0016] Preferably, in step (2) above, the cellulose is one or more of lignocellulose, cotton cellulose, and bacterial cellulose, and the diameter of the cellulose is preferably 0.01-5 micrometers.

[0017] Preferably, the evaporation material is obtained by mixing carbon black, ethyl cellulose, and terpineol in a mass ratio of 1:2:6.

[0018] Compared with existing technologies, this invention has the following advantages: The device proposed in this application proposes an integrated moisture absorption-evaporation working mode. In this mode, the device's own absorption and evaporation of moisture in the air can form a self-sustaining water content gradient inside the device. Driven by this water content gradient, the directional movement of ions allows the device to generate voltage and current for an extended period without requiring artificial energy input or additional liquid water as an evaporation source. This device can generate approximately 0.75V and 7μA of electricity through continuous absorption and evaporation of water in the environment, and can sustain continuous output for more than 10 days. The electricity generated by the device changes with relative humidity; at RH=20%, the device can generate 0.37V, and the voltage and current generated are higher than existing continuously generating moisture-generating devices (existing devices typically generate less than 1 microamp), making it suitable for self-powered devices in ordinary atmospheric environments. Furthermore, the device is simple to manufacture, uses inexpensive and readily available raw materials, and the manufacturing process is simple, allowing for large-scale production. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the moisture absorption and evaporation integrated power generation device of the present invention.

[0020] Figure 2 The voltage and current-time signal diagrams are obtained from the actual test of the power generation device in Example 1.

[0021] Wherein, 1-first electrode, 2-second electrode, 3-cellulose moisture-absorbing layer, 4-cellulose evaporation layer. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0023] Cellulose: Cotton cellulose paper, purchased from Shanghai Peixin Paper Industry, 1mm thick.

[0024] Conductive carbon adhesive: Zhejiang Lijin Technology, double-sided conductive carbon adhesive;

[0025] All materials used in other embodiments were purchased through commercial channels.

[0026] Example 1: Fabrication of a cellulose-based hygroscopic evaporation integrated power generation device

[0027] The specific preparation steps are as follows:

[0028] (1) Dissolve 10g of lithium chloride in 100ml of deionized water to prepare a desiccant with a lithium chloride mass fraction of 9% for later use;

[0029] Carbon black, ethyl cellulose, and terpineol were dispersed in ethanol at a mass ratio of 1:2:6 to prepare a slurry. (Generally, ethanol evaporates in the subsequent drying step, so the amount of ethanol added in this step can be within the range of 10%-40% of the mass percentage of the evaporated material to achieve the purpose of the invention; in this embodiment, the mass ratio of carbon black, ethyl cellulose, terpineol, and ethanol in the obtained slurry is 1:2:6:20).

[0030] (2) Prepare cellulose sheets into 3x3 cm sheets. 2 The square shape was cleaned with deionized water and then immersed in desiccant and carbon black slurry for 30 minutes respectively. Then it was taken out and dried at 100°C to make cellulose moisture-absorbing layer 3 and cellulose evaporation layer 4 respectively.

[0031] (3) Press the cellulose moisture-absorbing layer 3 and the cellulose evaporation layer 5 together at a pressure of 1 MPa, and then seal the edges with a paraffin film; connect the first electrode 1 and the second electrode 2 (both made of conductive carbon glue) to the outer surfaces of the cellulose moisture-absorbing layer 3 and the cellulose evaporation layer 4 respectively, and a cellulose-based moisture-absorbing and evaporation integrated power generation device is obtained.

[0032] The device structure obtained in this embodiment is as follows: Figure 1 As shown. The power generation device includes a first electrode 1, a cellulose moisture-absorbing layer 3, a cellulose evaporation layer 4, and a second electrode 2. The inner surfaces of the cellulose moisture-absorbing layer 3 and the cellulose evaporation layer 4 are tightly attached. The first electrode 1 is connected to the outer surface of the cellulose moisture-absorbing layer, and the second electrode 2 is connected to the outer surface of the cellulose evaporation layer.

[0033] The open-circuit voltage and short-circuit current output of the cellulose-based hygroscopic evaporative generator obtained in this embodiment were tested using a Keithley 6500 multimeter in two-electrode mode. The test results are as follows: Figure 2 As shown. Figure 2 In the diagram, 'a' represents voltage and 'b' represents current. It can be seen that, without any human-induced energy input, this power generation device can sustainably produce approximately 0.8 V and 7 μA of electrical output for an extended period in an atmospheric environment at 25°C and 60% relative humidity.

[0034] Compared to existing moisture-generating devices, the power generation device obtained in this embodiment drives the continuous directional transport of water and ions inside the device through moisture absorption and evaporation. Moisture is directionally transported from the surface of the cellulose moisture-absorbing layer to the inside and evaporates from the outer surface of the cellulose evaporation layer. Relying on the device's own absorption and evaporation of moisture in the air, it can generate voltage and current in a long-term self-sustaining manner. It has practical value and potential application prospects in the self-powering of devices in atmospheric environments.

[0035] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A cellulose-based moisture-absorbing and evaporative power generation device, characterized in that, The power generation device includes a first electrode, a cellulose moisture-absorbing layer, a cellulose evaporation layer, and a second electrode; The cellulose moisture-absorbing layer and the cellulose evaporation layer are bonded together, with the first electrode connected to the outer surface of the cellulose moisture-absorbing layer and the second electrode connected to the outer surface of the cellulose evaporation layer; The cellulose absorbent layer is obtained by impregnating cellulose sheets with a desiccant and then drying them; the desiccant is a solution of a desiccant material with a concentration not exceeding 30%; the desiccant includes one of lithium chloride, clay, silica gel, and water-absorbing MOFs. The cellulose evaporation layer is obtained by impregnating cellulose sheets with a slurry and then drying them; the slurry is an ethanol solution of the evaporation material; the evaporation material is obtained by mixing carbon black, ethyl cellulose, and terpineol in a mass ratio of 1:2:

6.

2. The cellulose-based moisture-absorbing and evaporative integrated power generation device according to claim 1, characterized in that, The thickness of the cellulose moisture-absorbing layer is 0.1-3 mm, and the thickness of the cellulose evaporation layer is 0.1-3 mm.

3. The method for preparing the cellulose-based hygroscopic evaporation integrated power generation device as described in claim 1 or 2, characterized in that, The specific steps are as follows: 1) Add the moisture-absorbing material to deionized water to prepare a moisture absorbent with a mass fraction not exceeding 30%, and set aside for later use; The evaporation material is dispersed in ethanol to prepare a slurry for later use; the evaporation material accounts for 10%-40% of the slurry by mass. The moisture-absorbing material includes one of lithium chloride, clay, silica gel, and water-absorbing MOFs; The evaporation material is obtained by mixing carbon black, ethyl cellulose, and terpineol in a mass ratio of 1:2:

6. 2) Immerse the cellulose sheets in the hygroscopic agent and the evaporation slurry respectively for at least half an hour, then remove and dry them to obtain the cellulose hygroscopic layer and the cellulose evaporation layer for later use; 3) After pressing the cellulose moisture-absorbing layer and the cellulose evaporation layer together, the edges are sealed with a paraffin film; then the first electrode and the second electrode are respectively connected to the outer surfaces of the cellulose moisture-absorbing layer and the cellulose evaporation layer to obtain a cellulose-based moisture-absorbing and evaporation integrated power generation device.

4. The method for preparing the cellulose-based hygroscopic evaporation integrated power generation device as described in claim 3, characterized in that, The drying temperature in step 2) is 70-120℃.

5. The method for preparing the cellulose-based hygroscopic evaporation integrated power generation device as described in claim 3, characterized in that, Step 1) The cellulose sheet material includes one of lignocellulose, cotton cellulose, and bacterial cellulose.

6. The method for preparing the cellulose-based hygroscopic evaporation integrated power generation device as described in claim 3, characterized in that, Step 1) The first electrode and the second electrode are made of inorganic conductive materials or metallic conductive materials.

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