Wind and rain energy collaborative collection friction nanometer generator

Abstract

The invention discloses a wind and rain energy collaborative collection friction nanometer generator, which comprises a wind energy collection unit and a raindrop energy collection unit, and is characterized in that the wind energy collection unit comprises wind cups, a rotating shaft, a sleeve, end covers, a scraper blade, an inertia body, a film and a metal electrode, the sleeve and the end covers at the two ends of the sleeve form a sealed cavity, and the wind cups are arranged at the two sections of the rotating shaft; the rotating shaft is rotationally connected with the end cover, a metal electrode is arranged on the inner side of the sleeve, a film is arranged on the inner side of the metal electrode, the scraper is connected with the rotating shaft and divides a cavity defined by the film and the rotating shaft into a plurality of cavities, and an inertia body is arranged in at least one cavity; a raindrop energy collecting unit is arranged on the outer surface of the sleeve. Efficient and stable collaborative collection of wind energy and raindrop energy is achieved, the wind energy collection unit and the raindrop energy collection unit can work independently and can also achieve multi-source environment energy collection, and the output performance and durability are remarkably improved; finally, the open-circuit voltage of the device reaches 700V, and the peak power reaches 6.1 mW.

Description

Technical Field

[0001] This invention pertains to generators, specifically a triboelectric nanogenerator that co-collects wind and rain energy. Background Technology

[0002] With the rapid development of IoT technology, large-scale distributed sensor networks have become an important foundation for environmental monitoring systems. However, in application scenarios with complex environmental conditions and limited operation and maintenance, such as offshore areas and islands, traditional energy solutions relying on batteries or wired power supply generally suffer from high maintenance costs and insufficient reliability, severely restricting the long-term stable operation and large-scale deployment of sensor networks. Wind energy and rain energy, as two widely distributed and sustainably obtainable forms of kinetic energy in nature, provide potential long-term energy sources for self-powered sensor systems. Triboelectric nanogenerators (TENGs) have attracted widespread attention in the field of energy harvesting in complex environments in recent years due to their advantages such as lightweight structure, flexible form, and high energy conversion efficiency for low-frequency weak mechanical excitation. Various structures based on wind or rain energy have been developed to power low-power sensors.

[0003] However, most existing TENG designs are still limited to utilizing a single energy source. Furthermore, the raindrop impact process is characterized by significant randomness and disorder, limiting effective energy capture efficiency and hindering improvements in output level and stability. In contrast, while wind-driven contact-separation or rolling triboelectric nanogenerators can improve output performance by increasing the effective frictional contact area, they often suffer from accelerated wear of frictional materials, shortened device lifespan, and increased start-up wind speeds, making it difficult to achieve high output while maintaining low wind speeds and high durability. More critically, in real-world environments, wind and rain often coexist and couple: raindrop wetting disrupts the frictional interface and interferes with the wind-driven contact-separation process, while wind deflects raindrop trajectories, reducing effective liquid-solid contact. This coupling interference further weakens energy harvesting efficiency and system reliability. Therefore, achieving efficient and stable coordinated harvesting of wind and raindrop energy in environments where wind and rain coexist remains a pressing issue in the field of triboelectric nanogenerators. Existing wind and rain energy combined harvesting devices, such as patent CN211082142U, require the droplets to act precisely at specific locations to achieve effective output, resulting in low utilization efficiency in complex and variable natural environments. Furthermore, the invention in patent CN110138260A does not adequately consider weak excitation conditions and the impact of rainwater intrusion on the interface, leading to high requirements for the device's driving conditions and insufficient stability and reliability during actual operation. Summary of the Invention

[0004] Purpose of the invention: In order to overcome the shortcomings of the existing technology, the purpose of this invention is to provide a triboelectric nanogenerator that can collect wind and rain energy in a coordinated manner, with good mechanical durability, good long-term stability and high utilization efficiency.

[0005] Technical Solution: The present invention discloses a wind and rain energy co-collection triboelectric nanogenerator, comprising a wind energy collection unit and a raindrop energy collection unit. The wind energy collection unit includes a wind cup, a rotating shaft, a sleeve, end caps, a scraper, an inertial body, a thin film, and a metal electrode. The sleeve and the end caps at both ends form a sealed cavity. Wind cups are provided at both ends of the rotating shaft, which is rotatably connected to the end caps. A metal electrode is provided inside the sleeve, and a thin film is provided inside the metal electrode. The scraper is connected to the rotating shaft and divides the cavity enclosed by the thin film and the rotating shaft into multiple cavities. An inertial body is provided in at least one cavity. A raindrop energy collection unit is provided on the outer surface of the sleeve.

[0006] For the wind energy harvesting unit, an encapsulation design prevents rainwater from penetrating and damaging the friction interface. In addition, the internal spheres are designed with an asymmetrical motion pattern of strong contact in the first half and weak contact in the second half, and a discrete electrode design is used to match the motion trajectory to maximize electrostatic induction efficiency.

[0007] Furthermore, the raindrop energy collection unit includes a friction layer and an electrode network. The friction layer is disposed on the outer surface of the sleeve, and the electrode network is disposed on the friction layer. The friction layer is a curved, high-humidity resistant friction layer, which not only eliminates wind-induced raindrop deflection but also enables rapid droplet desorption, avoiding charge shielding caused by droplet retention, thus preventing output degradation. Addressing the characteristics of random, large-area, and non-directional raindrop impact, an electrode network design is introduced, enabling efficient collection of large-area raindrop energy.

[0008] Furthermore, the electrode network is made of an AB silica gel solution and carbon nanotubes in a mass ratio of 98-99:1-2. The electrode network is strip-shaped, rhomboid, or rectangular, preferably rhomboid.

[0009] Furthermore, the inertial body is a polytetrafluoroethylene (PTFE) sphere, and the film is a nylon film.

[0010] Furthermore, the PTFE spheres include large and small spheres, with a gap between the scraper and the film. The gap is smaller than the diameter of the large sphere but larger than the diameter of the small sphere. During rotation, the large sphere remains within the same cavity, while the small sphere can pass through the gap into other cavities. This multi-sized sphere indirect excitation strategy effectively enhances triboelectric charging without significantly increasing the driving load.

[0011] Furthermore, the large sphere has a diameter of 9-15 mm, and the small sphere has a diameter of 1-7 mm. The large sphere can be directly driven by the rotating shaft, while the small PTFE sphere cannot be directly driven by the rotating shaft and needs to be indirectly activated through the large sphere.

[0012] Furthermore, the metal electrodes are copper electrodes, and there are four or more of them. Each copper electrode is equipped with a lead wire, and the spacing between the copper electrodes is 1 to 3 cm.

[0013] Furthermore, the end cap is connected to the bracket.

[0014] Furthermore, the shaft is rotatably connected to the end cover via bearings.

[0015] Furthermore, the diameter of the sleeve is 4~10 cm.

[0016] Working Principle: Under the action of wind power, the wind cup drives the rotating shaft to rotate, which in turn causes the scraper to rotate within the membrane cavity. In the initial stage of motion, the scraper mainly drives the large spheres, with only a few small spheres being driven, resulting in a small additional load on the scraper. As rotation continues, the large spheres partially detach from the scraper in the latter half of the motion cycle. At the beginning of each subsequent motion cycle, the detached large spheres collide with the previously inactive small spheres due to inertia. In this process, further activation of the small spheres mainly relies on inertial collisions between the spheres, rather than direct drive by the scraper, thus avoiding a large load. For the external raindrop energy collection unit, when water droplets fall and impact the friction layer, they spread rapidly, during which charge transfer occurs: the friction layer gains electrons and becomes negatively charged, while the water droplets lose electrons and become positively charged. As the water droplets continue to spread and contact the electrode network, driven by the potential difference, electrons flow through the external circuit to neutralize the positive charge in the water droplets, thereby forming a momentary external current. Subsequently, the water droplet slides down the curved friction layer. This curved surface design inhibits water droplet retention and creates favorable conditions for the subsequent charge transfer process.

[0017] Beneficial effects: Compared with the prior art, the present invention has the following significant features:

[0018] 1. It achieves efficient and stable collaborative collection of wind energy and raindrop energy. The wind energy collection unit and the raindrop energy collection unit can work independently or collaboratively collect energy from multiple sources of the environment, resulting in a significant improvement in output performance and durability.

[0019] 2. By introducing asymmetric motion and indirect excitation strategies, the wind energy harvesting unit in this invention can operate at a wind speed of 3 m / s, with an open-circuit voltage of 660 V and a peak output power of 5.29 mW.

[0020] 3. By adopting a ball-point contact rolling working mode, the wind energy harvesting unit in this invention effectively reduces interface wear. After 10 million continuous working cycles, the output performance does not show significant decay, demonstrating excellent mechanical durability and long-term stability.

[0021] 4. By designing a curved structure and introducing an electrode network, the raindrop energy collection unit in this invention achieves effective collection of large-area, randomly incident raindrops, with a transfer charge of up to 202 nC and a peak output power of 4.05 mW, significantly improving the raindrop energy utilization efficiency.

[0022] 5. By ensuring that the surface of the friction layer is uniformly subjected to raindrop impacts, the raindrop energy collection unit in this invention can still maintain a stable output of 120 V after experiencing 2.5 million droplet impacts, demonstrating excellent stability.

[0023] 6. Through spatial partitioning design, the wind and rain energy co-collection triboelectric nanogenerator of the present invention realizes the co-collection of wind energy and raindrop energy. In the co-working state, the open circuit voltage reaches 700 V and the peak output power is 6.1 mW. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0025] Figure 2 This is an exploded structural diagram of the present invention;

[0026] Figure 3 This is a connection diagram of the wind energy harvesting unit 1 of the present invention;

[0027] Figure 4 This is a schematic diagram of the structure of the raindrop energy collection unit 2 of the present invention;

[0028] Figure 5 This is a schematic diagram of the metal electrode 108 of the present invention;

[0029] Figure 6 This is the open-circuit voltage and peak power diagram of the present invention, wherein a is the voltage versus time diagram, and b is the output current and peak power versus external resistance diagram;

[0030] Figure 7 This is a diagram of open-circuit voltage, short-circuit current, and transferred charge according to the present invention, wherein a is a diagram of open-circuit voltage versus time, b is a diagram of short-circuit current versus time, and c is a diagram of transferred charge versus time.

[0031] Figure 8 This is a diagram showing the open-circuit voltage of different electrode pairs in this invention;

[0032] Figure 9 This is a graph showing the relationship between the open-circuit voltage and time of the metal electrode 108 under different numbers of large balls and wind speeds according to the present invention;

[0033] Figure 10 This is a schematic diagram of the metal electrode 108 and an open-circuit voltage diagram in the two-electrode design of the present invention, wherein a is a schematic diagram of the structure of the metal electrode 108 and b is a diagram of the relationship between open-circuit voltage and time.

[0034] Figure 11 This is an open-circuit voltage diagram of the present invention under different numbers of large and small balls;

[0035] Figure 12This is a graph showing the change in open-circuit voltage during the durability cycle of this invention;

[0036] Figure 13 This is a graph showing the relationship between the transferred charge and time in this invention;

[0037] Figure 14 This is a charge transfer diagram of the present invention under different substrate diameters;

[0038] Figure 15 This is an open-circuit voltage diagram of the present invention at different raindrop incident angles;

[0039] Figure 16 This is a graph showing the change in open-circuit voltage during the durability cycle of this invention. Detailed Implementation

[0040] Unless otherwise specified, all materials and reagents used in the following examples are commercially available. Experimental methods not specifically described in the examples are generally performed under standard conditions or as recommended by the manufacturer. AB silica gel solution was purchased from Sanjing Xinde Technology Co., Ltd., carbon nanotubes from Suzhou CarbonFeng Technology Co., Ltd., and PDMS from Dow Corning. PTFE nanoparticles were purchased from Yixin Plastics Technology Co., Ltd. BaTiO3 particles and ethanol were purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.

[0041] Example 1

[0042] like Figures 1-4The wind and rain co-collecting triboelectric nanogenerator includes an internal wind energy collection unit 1 and an external raindrop energy collection unit 2. The wind energy collection unit 1 includes a wind cup 101, a rotating shaft 102, a sleeve 103, an end cap 104, a scraper 105, an inertial body 106, a thin film 107, and a metal electrode 108. The left and right ends of the sleeve 103 are sealed by the end cap 104, forming a sealed cavity. The inertial body 106 and the metal electrode 108 are encapsulated inside the sleeve 103. The outer side of the end cap 104 is riveted to a bracket 4, and a bearing 109 is rotatably connected to the center of the end cap 104. The rotating shaft 102 is rotatably connected to the end cap 104 via the bearing 109, providing support and limiting its position. Both ends of the rotating shaft 102 are fixedly connected to the wind cup 101. The sleeve 103 has a diameter of 8 cm and a height of 6 cm. A metal electrode 108 is disposed inside the sleeve 103, and a thin film 107 is disposed inside the metal electrode 108. The thin film 107 is a nylon film, and its area is the same as the area of ​​the inner wall of the sleeve 103. A scraper 105 is fixedly connected to a rotating shaft 102 and divides the cavity formed by the thin film 107 and the rotating shaft 102 into two cavities 3. At least one cavity 3 contains an inertial body 106, which is a PTFE sphere. A raindrop energy collection unit 2 is disposed on the outer surface of the sleeve 103. The raindrop energy collection unit 2 includes a friction layer 201 and an electrode network 202. The friction layer 201 is adhered and fixed to the outer surface of the sleeve 103, and the electrode network 202 is fixed to the outer surface of the friction layer 201. The electrode network 202 is made of an AB silica gel solution and carbon nanotubes with a mass ratio of 99:1. The electrode network 202 is rhomboid in shape.

[0043] The method for preparing the friction layer 201 in the raindrop energy collection unit 2 includes the following steps:

[0044] (1) Mix 3.6 g of PDMS with 0.4 g of curing agent to prepare PDMS solution. Mix PTFE particles with ethanol and disperse by ultrasonication to obtain PTFE suspension.

[0045] (2) Mix 1 g BaTiO3 particles with 4 g PDMS solution and disperse by ultrasonication to obtain a mixture.

[0046] (3) Apply the mixture from step (2) to the surface of sleeve 103, vacuum it, and dry and pre-cur it at 60 °C for 12 min.

[0047] (4) Spray the PTFE suspension onto the coating obtained in step (3) and dry and cure it at 60 °C for 1 h.

[0048] The preparation method of electrode network 202 includes the following steps: AB silica gel solution and carbon nanotubes are mixed at a mass ratio of 1% and stirred evenly. The resulting mixed solution is coated on the surface of friction layer 201 to form an electrode network precursor. The precursor is placed in a drying oven and dried and cured at 60 °C for 1 h to obtain electrode network 202.

[0049] like Figure 5 The metal electrode 108 consists of four copper electrodes, each with a wire extending from its center and fixed to the inner wall of the sleeve 103 in a stacked arrangement. The copper electrodes are spaced 3 cm apart and are evenly attached to the back of the film 107. The PTFE spheres include large and small spheres. A gap is provided between the scraper 105 and the film 107, the gap being smaller than the diameter of the large sphere but larger than the diameter of the small sphere. The large sphere has a diameter of 10.5 mm, the small sphere has a diameter of 5 mm, and the ratio of large to small spheres is 4:40.

[0050] like Figure 6 As shown, the output performance was tested under wind and rain co-excitation, with an open-circuit voltage of 700V and a peak power of 6.1mW. This is thanks to the spatial partitioning design, which avoids the low energy collection efficiency caused by mutual interference between wind and rain, and achieves efficient wind and rain co-excitation.

[0051] Example 2

[0052] The remaining steps in this embodiment are the same as in Embodiment 1, the only difference being that the output performance is tested only under wind excitation. Figure 7 As shown, the open-circuit voltage, short-circuit current, and transferred charge reached 660 V, 75 μA, and 733 nC, respectively.

[0053] Example 3

[0054] The remaining steps in this embodiment are the same as in Embodiment 2, except that the inertial bodies 106 are only large spheres, and there are four of them. The output performance of adjacent electrode pairs in the four metal electrodes 108 was tested respectively. Figure 8 As shown, the overall output level of the electrode pair in the first half of the motion is significantly higher than that of the electrode pair in the second half, and the output performance of electrode pair 1-2 is the best, with an open-circuit voltage of up to 225 V. This is mainly because the PTFE microspheres have a strong interaction with the wall surface in the first half of the motion, resulting in a significant triboelectric effect; while in the second half, the supporting force of the wall surface on the microspheres weakens, and some microspheres even fall off, leading to a decrease in both the triboelectric effect and the electrostatic induction effect, thus causing a decline in the output performance of the corresponding electrode pair.

[0055] Example 4

[0056] The remaining steps in this embodiment are the same as in Embodiment 3, except that the number of inertial bodies 106 are 1, 2, 3, and 5 respectively, and the output of electrode pairs 1-2 is tested at different wind speeds. The results are as follows: Figure 9 As shown, the output voltage initially increases and then remains constant with the increase in the number of large balls, reaching its optimal performance when there are three large balls. This is because an appropriate number of small balls increases the collision frequency and friction area, thereby promoting charge separation and accumulation; while an excessive number of small balls increases the driving load, raises the starting wind speed, and makes it difficult to further improve output performance. When the wind speed increases from 2.5 m / s to 8.5 m / s, the output voltage increases from 105 V to 228 V. This is because the higher wind speed significantly enhances the kinetic energy of the large balls and the contact separation efficiency, thus improving output performance.

[0057] Comparative Example 1

[0058] Comparative Example 1 is the same as Example 3, except that the metal electrode 108 is divided into two pieces, which are attached to the back of the film 107 at equal intervals, as shown below. Figure 10 As shown, the elements are attached to the inner wall of the sleeve 103, and from the inside out, they are: film 107, metal electrode 108, and sleeve 103. The output performance of the device was tested under the above structural conditions, and its open-circuit voltage was only 178 V, significantly lower than the 225 V obtained under the optimal structure described in Example 3. This is because, in this dual-electrode structure, the contact between the ball and the friction layer is weaker in the latter half of its movement, resulting in a lower overall potential difference between the electrodes, thus causing a decrease in output performance.

[0059] Comparative Example 2

[0060] The remaining steps in this embodiment are the same as in Embodiment 3, except that the number of large PTFE balls and small PTFE balls is different. Specifically, the number of large balls is 1, 2, 3, or 5, and the number of small balls is 10, 20, 30, or 50, and the output performance is tested accordingly. Figure 11 As shown, experimental results indicate that the device's output performance first increases and then decreases with the increase of the number of small balls, and there is a significant dependence between the optimal number of small balls and the number of large balls. Specifically, when the number of large balls is 1-2, the optimal number of small balls is 20; when the number of large balls increases to 3-5, the optimal number of small balls increases accordingly to 40. The device achieves a peak output V of 436V when the ratio of large balls to small balls is 4:40. This is because when there are fewer large balls, the number of small balls that can be excited is limited, and a large number of small balls deposited at the bottom actually hinders movement; while with an increase in the number of large balls, the excitation effect is enhanced, and more small balls participate in triboelectric charging, thus improving performance.

[0061] Example 5

[0062] The remaining steps in this embodiment are the same as in Embodiment 2. The durability of the wind energy harvesting unit 1 was tested, and the test results are as follows: Figure 12 As shown, under conditions of up to 5 million working cycles, the output performance of the device did not show significant degradation. This is because the point-contact rolling working mode adopted in this invention effectively reduces the frictional contact area and avoids long-term repetitive wear in localized areas, thereby significantly improving the durability and service life of the device.

[0063] Example 6

[0064] The remaining steps in this embodiment are the same as in Embodiment 1, except that: in this embodiment, the output performance of the device is tested only under raindrop excitation conditions, and the results are as follows. Figure 13 As shown, its transferred charge can reach 202 nC.

[0065] Comparative Example 3

[0066] The remaining steps in this embodiment are the same as in Embodiment 6, except that the diameter of the sleeve 103 is different, being 4cm, 6cm, and 10cm respectively. A comparative test was conducted on the output performance of the raindrop energy collection unit 2. Figure 14 As shown, its output performance first increases and then decreases with increasing substrate diameter, reaching a peak of 202 nC at a diameter of 8 cm. This is because a moderate curvature can effectively expand the effective rain-receiving area of ​​the device and enhance the tangential driving force of the droplets on the surface, thereby accelerating the droplet sliding process; however, when the diameter of the sleeve 103 is too large, its top planar area increases accordingly, making it easier for droplets to stagnate and accumulate, which in turn induces a charge shielding effect, leading to a decrease in output performance.

[0067] Example 7

[0068] The remaining steps in this embodiment are the same as in Embodiment 6. The output performance of the raindrop energy collection unit was tested under different raindrop incident angles. The results are as follows: Figure 15 As shown, when raindrops impact the raindrop energy collection unit with different incident directions (-90°~90°), its output performance remains basically stable. This is because the curved surface structure design employed in this invention ensures a high degree of consistency in the contact state and interaction process between the droplets and the friction layer 201 under different directional excitation conditions, thereby guaranteeing stable output performance under multi-directional raindrop incident conditions.

[0069] Example 8

[0070] The remaining steps in this embodiment are the same as in Embodiment 6. The durability of the raindrop energy collection unit 2 was tested. For example... Figure 16As shown, under conditions of 2.5 million consecutive droplet impacts, the device's output performance can still maintain 120 V, indicating long-term operational stability. This is because the raindrop energy collection unit of this invention effectively avoids the severe wear problem caused by localized concentrated impacts in traditional droplet triboelectric nanogenerators by uniformly distributing raindrop impacts across the friction layer surface, thereby significantly improving durability and service life.

Claims

1. A triboelectric nanogenerator that co-collects wind and rain energy, characterized in that: The system includes a wind energy collection unit (1) and a raindrop energy collection unit (2). The wind energy collection unit (1) includes a wind cup (101), a rotating shaft (102), a sleeve (103), an end cap (104), a scraper (105), an inertial body (106), a thin film (107), and a metal electrode (108). The sleeve (103) and the end caps (104) at both ends form a sealed cavity. Wind cups (101) are provided at both ends of the rotating shaft (102). The sleeve (103) is rotatably connected to the end cap (104). A metal electrode (108) is provided inside the sleeve (103). A thin film (107) is provided inside the metal electrode (108). The scraper (105) is connected to the rotating shaft (102) and divides the cavity formed by the thin film (107) and the rotating shaft (102) into multiple cavities (3). At least one of the cavities (3) is provided with an inertial body (106). A raindrop energy collection unit (2) is provided on the outer surface of the sleeve (103).

2. The wind and rain co-harvesting triboelectric nanogenerator according to claim 1, characterized in that: The raindrop energy collection unit (2) includes a friction layer (201) and an electrode network (202). The friction layer (201) is disposed on the outer surface of the sleeve (103), and the electrode network (202) is disposed on the friction layer (201).

3. The wind and rain co-harvesting triboelectric nanogenerator according to claim 2, characterized in that: The electrode network (202) is made of AB silica gel solution and carbon nanotubes in a mass ratio of 98~99:1~2.

4. The wind and rain co-harvesting triboelectric nanogenerator according to claim 1, characterized in that: The inertial body (106) is a polytetrafluoroethylene sphere, and the film (107) is a nylon film.

5. The wind and rain co-harvesting triboelectric nanogenerator according to claim 4, characterized in that: The polytetrafluoroethylene spheres include large spheres and small spheres. A gap is provided between the scraper (105) and the film (107). The gap is smaller than the diameter of the large sphere and larger than the diameter of the small sphere.

6. The wind and rain co-harvesting triboelectric nanogenerator according to claim 5, characterized in that: The large sphere has a diameter of 9-15 mm, and the small sphere has a diameter of 1-7 mm.

7. The wind and rain co-harvesting triboelectric nanogenerator according to claim 1, characterized in that: The metal electrode (108) is a copper electrode, and there are four or more of them. Each copper electrode is provided with a lead wire, and the spacing between the copper electrodes is 1 to 3 cm.

8. The wind and rain co-harvesting triboelectric nanogenerator according to claim 1, characterized in that: The end cap (104) is connected to the bracket (4).

9. A triboelectric nanogenerator for co-harvesting wind and rain energy according to claim 1, characterized in that: The rotating shaft (102) is rotatably connected to the end cover (104) via a bearing (109).

10. A triboelectric nanogenerator for co-harvesting wind and rain energy according to claim 1, characterized in that: The diameter of the sleeve (103) is 4~10 cm.

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