Hybrid nanometer generator

Abstract

The invention discloses a hybrid nano-generator, and belongs to the field of nano-generators. Comprising a shell, a friction nanometer generator module and an electromagnetic generator module which are arranged in the shell, and further comprises an elastic transmission assembly and an inertia mass block which are arranged in the center in the shell, the elastic transmission assembly comprises a plurality of elastic strips which are fixed in a crossed mode, and multiple ends, away from a crossed fixing point, of the elastic strips bend upwards and converge towards the center; the elastic transmission assembly is arranged on the base to form an arched cage-shaped structure, the inertia mass block is fixedly arranged in the center of the top of the elastic transmission assembly, the friction nanometer generator module comprises a plurality of TENG units arranged on the periphery of the elastic transmission assembly, and the electromagnetic generator module comprises a rotor and a rotor. The elastic system with a resonance enhancement mechanism is designed, the problem that the low-frequency wave energy capturing efficiency is low is solved, large-amplitude mechanical response is achieved under low-frequency excitation, and the output power of the friction nanometer generator module and the electromagnetic generator module in the low-frequency wave band is remarkably improved.

Description

Technical Field

[0001] This invention relates to a triboelectric nanogenerator, and more particularly, to a hybrid nanogenerator. Background Technology

[0002] Oceans cover more than 70% of the Earth's surface and contain enormous mechanical energy resources, collectively known as "blue energy." However, despite its promising prospects, the large-scale commercial development of wave energy is currently limited by several core technological bottlenecks. Ocean wave motion is typically characterized by low frequency (usually less than 2-5 Hz) and irregularity. Traditional electromagnetic generators are mainly based on the Lorentz force principle, and their output power is proportional to the square of the frequency. They are highly efficient under high-speed rotation or high-frequency vibration, but under low-frequency wave excitation, their magnetic flux change rate is low, leading to a sharp drop in output voltage and power, as well as bulky size and low efficiency.

[0003] To address the challenges of low-frequency micro / nano energy harvesting, Academician Wang Zhonglin's team invented the triboelectric nanogenerator (TENG) in 2012. Based on the coupling principle of contact electrification and electrostatic induction, TENGs can efficiently convert low-frequency mechanical energy in the environment into electrical energy. Compared to traditional EMGs, TENGs have unique advantages at low frequencies: they have high output voltage and their output energy density varies linearly with frequency (rather than a square relationship), thus exhibiting higher energy conversion efficiency in the low-frequency band. Furthermore, TENGs possess advantages such as simple structure, wide range of materials (mainly polymers), light weight, and low cost. However, directly applying TENGs to ocean wave energy harvesting still faces significant challenges. Moving TENG technology from the laboratory environment to real-world ocean applications requires solving two key problems: environmental shielding effects and impedance mismatch.

[0004] To overcome the limitations of single technologies, "hybrid nanogenerators" integrating TENGs and EMGs have become a research hotspot in recent years. This hybrid architecture aims to combine the high current and low impedance characteristics of EMGs with the high voltage and low-frequency high efficiency of TENGs to achieve full-band, wide-amplitude wave energy capture. However, existing hybrid generator designs still have structural and mechanistic defects, such as the pendulum inertial generator. This type of design encapsulates the generator inside a sealed sphere or cylinder, utilizing a built-in gravity pendulum as the inertial mass. When the sphere oscillates with waves, the pendulum oscillates relative to the shell, driving the internal TENG and EMG. Defects include: 1. Poor contact stability: Under irregular wave excitation, the contact between the pendulum and the inner wall of the shell is often intermittent and non-uniform. This unstable contact leads to severe fluctuations in the TENG output voltage, making effective power management difficult. 2. Narrow frequency response range: The pendulum system has a fixed natural frequency. Only when the external wave frequency strictly matches the pendulum's natural frequency can a large-amplitude oscillation be generated. For real sea conditions with varying frequencies, this structure has a narrow energy capture bandwidth and low efficiency. 3. Low space utilization: In order to ensure that the pendulum has enough space to swing, a huge cavity is often required inside the sphere, resulting in a low volumetric energy density of the device. Summary of the Invention

[0005] The purpose of this invention is to provide a hybrid nanogenerator to overcome the shortcomings of low-frequency wave energy capture efficiency in existing hybrid nanogenerators.

[0006] This invention is achieved using the following technical solution:

[0007] A hybrid nanogenerator includes a housing and a triboelectric nanogenerator module and an electromagnetic generator module disposed inside the housing. It also includes an elastic transmission component and an inertial mass block disposed at the center of the housing. The elastic transmission component includes multiple elastic strips that are intersected and fixed, with multiple ends away from the intersection point bending upwards and converging towards the center to form an arched cage structure. The inertial mass block is fixed at the top center of the elastic transmission component. The triboelectric nanogenerator module includes multiple TENG units disposed around the elastic transmission component. The electromagnetic generator module includes a mover and a rotor. The mover is fixed inside the top center of the elastic transmission component, and the stator is fixed at the bottom center of the elastic transmission component, directly opposite the mover above.

[0008] Furthermore, the outer shell is a fully enclosed box structure.

[0009] Furthermore, the elastic strip is made of Kapton material.

[0010] Furthermore, the mover is a high-performance neodymium iron boron cylindrical permanent magnet, and the stator is a multi-turn copper coil.

[0011] Furthermore, the TENG unit includes an inner electrode layer, a negative polarity friction layer, a positive polarity friction layer, an outer electrode layer, and a rigid support backplate arranged from the inside out. The inner electrode layer is a conductive fabric adhered to the outside of the elastic strip. The negative polarity friction layer is an FEP film adhered to the inner electrode layer. The positive polarity friction layer is an SA / PEI composite film. The outer electrode layer is a conductive fabric adhered to the back of the SA / PEI film. The rigid support backplate is fixed to the inner wall of the outer shell.

[0012] Furthermore, the preparation process of the SA / PEI composite membrane is as follows: Solution preparation: Dissolve 3 g of sodium alginate (SA) and 1 g of polyethyleneimine (PEI) in 96 g of deionized water and stir at 45 °C for 6 hours; Crosslinking reaction: Add 0.15 g of epichlorohydrin (ECH) as a crosslinking agent and continue stirring for 12 hours; Freeze-drying: Pour the solution into a mold, freeze with liquid nitrogen, and then freeze-dry under vacuum at -50 °C for 24 hours to form an aerogel; Ion replacement: Immerse the aerogel in a 0.3 mol / L copper chloride solution for ion coordination to enhance its electron-acquiring ability, and then wash with acetone; Hot pressing film formation: Hot press at 1 MPa pressure for 5 seconds to obtain a dense SA / PEI film with a thickness of about 60 μm.

[0013] Compared with the prior art, the beneficial effects of the present invention are:

[0014] (1) This invention utilizes the nonlinear mechanical characteristics and resonance principle of the elastic transmission component with an arched cage structure to achieve resonance enhancement by forming a spring-oscillator system composed of the elastic transmission component and the inertial mass block. It successfully transforms the low-frequency motion of the ocean waves into faster contact-separation motion inside the triboelectric nanogenerator module. Experiments have shown that at a typical ocean wave frequency of 2.0 Hz, the system resonates and the internal amplitude is amplified, thereby enabling the triboelectric nanogenerator module to obtain the maximum contact pressure and separation speed, and enabling the electromagnetic generator module to obtain the maximum magnetic flux change rate. This design optimized for low frequency makes its energy conversion efficiency far exceed that of traditional generators of the same size, breaking through the bottleneck of extremely low efficiency of traditional electromagnetic generators at low frequencies.

[0015] (2) The “elastic arch lateral pressing” structure proposed in this invention cleverly decouples the single-dimensional vertical vibration into the horizontal motion of the TENG module and the vertical motion of the EMG module within a limited cubic space. This design makes full use of the side wall space and central space of the device, greatly improving the volume energy density. Compared with the pendulum design with a larger cavity, the space utilization rate of this invention is higher.

[0016] (3) The present invention adopts a fully enclosed rigid encapsulation, and the internal transmission relies entirely on inertial force and elastic deformation. It does not require any through-wall rotating shaft or dynamic sealing structure, which greatly reduces material wear and enables the device to withstand millions of wave cycles, significantly extending its service life. The core power generation components are completely physically isolated from corrosive seawater, which solves the fatal problems faced by traditional direct contact TENGs such as charge leakage, short circuit and biological attachment, enabling it to serve in real marine environments for a long time.

[0017] (4) The SA / PEI friction material used in this invention is derived from natural biomass, which is degradable and non-toxic. The entire device is mainly composed of polymer and a small amount of metal, which is inexpensive to manufacture and easy to mass-produce in arrays. Attached Figure Description

[0018] Figure 1 This is a side view of the structure of Embodiment 1 of the present invention;

[0019] Figure 2 This is a top view of the structure of Embodiment 1 of the present invention;

[0020] Figure 3 This is a schematic diagram of the overall structure of Embodiment 1 of the present invention;

[0021] Figure 4 This is a schematic diagram illustrating the working principle of the mechanical mode conversion in Embodiment 1 of the present invention;

[0022] Figure 5 This is a graph showing the relationship between the amount of transferred charge of the TENG module in Embodiment 1 of the present invention and the number of parallel units (1 to 4).

[0023] Figure 6 This is a bar chart showing the change of the open-circuit voltage of the TENG module in Embodiment 1 of the present invention with the external excitation frequency;

[0024] Figure 7 The curves showing the output power of the EMG module in Embodiment 1 of the present invention vary with the load resistance under different amplitudes (20 mm, 30 mm, 40 mm).

[0025] In the diagram: 1. Outer shell; 2. Electromagnetic generator module; 21. Moving element; 22. Rotor; 3. Triboelectric nanogenerator module; 31. TENG unit; 4. Inertial mass block; 5. Elastic transmission component; 51. Elastic strip. Detailed Implementation

[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] This invention provides a hybrid nanogenerator, including a housing 1 and a triboelectric nanogenerator module 3 and an electromagnetic generator module 2 disposed inside the housing 1. It also includes an elastic transmission component 5 and an inertial mass block 4 disposed at the center inside the housing 1. The elastic transmission component 5 includes multiple elastic strips 51, which are cross-fixed and their ends away from the cross-fixing point bend upwards and converge towards the center, forming an arched cage structure. The inertial mass block 4 is fixed at the top center of the elastic transmission component 5. The triboelectric nanogenerator module 3 includes multiple TENG units 31 disposed around the elastic transmission component 5. The electromagnetic generator module 2 includes a mover 21 and a rotor 22. The mover 21 is fixed inside the top center of the elastic transmission component 5, and the stator is fixed at the bottom center of the elastic transmission component 5, directly facing the mover 21 above.

[0028] Furthermore, the outer shell 1 is a fully enclosed box structure.

[0029] Furthermore, the elastic strip 51 is made of Kapton material.

[0030] Furthermore, the mover 21 is a high-performance neodymium iron boron cylindrical permanent magnet, and the stator is a multi-turn copper coil.

[0031] Furthermore, the TENG unit 31 includes, from the inside out, an inner electrode layer, a negative polarity friction layer, a positive polarity friction layer, an outer electrode layer, and a rigid support backplate. The inner electrode layer is a conductive fabric adhered to the outside of the elastic strip 51. The negative polarity friction layer is an FEP film adhered to the inner electrode layer. The positive polarity friction layer is an SA / PEI composite film. The outer electrode layer is a conductive fabric adhered to the back of the SA / PEI composite film. The rigid support backplate is fixed to the inner wall of the outer shell 1.

[0032] Furthermore, the preparation process of the SA / PEI composite membrane is as follows: Solution preparation: Dissolve 3 g of sodium alginate (SA) and 1 g of polyethyleneimine (PEI) in 96 g of deionized water and stir at 45 °C for 6 hours; Crosslinking reaction: Add 0.15 g of epichlorohydrin (ECH) as a crosslinking agent and continue stirring for 12 hours; Freeze-drying: Pour the solution into a mold, freeze with liquid nitrogen, and then freeze-dry under vacuum at -50 °C for 24 hours to form an aerogel; Ion replacement: Immerse the aerogel in a 0.3 mol / L copper chloride solution for ion coordination to enhance its electron-acquiring ability, and then wash with acetone; Hot pressing film formation: Hot press at 1 MPa pressure for 5 seconds to obtain a dense SA / PEI film with a thickness of approximately 60 μm.

[0033] Example 1

[0034] like Figure 1 , Figure 2 , Figure 3 As shown, in a specific embodiment of the present invention, a hybrid nanogenerator includes a housing 1, a triboelectric nanogenerator (TENG) module and an electromagnetic generator (EMG) module disposed inside the housing 1, and an elastic transmission component 5 and an inertial mass block 4 disposed at the center inside the housing 1.

[0035] The outer shell 1 is preferably a polystyrene (PS) box with dimensions of 15 cm × 15 cm × 6 cm and a wall thickness of about 3 mm. The seams are sealed with waterproof adhesive to ensure IP68 waterproof rating, serving as a waterproof enclosure and a floating carrier.

[0036] The triboelectric nanogenerator (TENG) module includes four independent TENG units 31, which correspond to the four sides of the elastic transmission component 5 respectively. Each TENG unit 31 adopts a vertical contact-separation mode and converts wave energy into a lateral driving mode to generate electricity through the elastic transmission component 5.

[0037] The TENG unit 31 comprises, from the inside out, an inner electrode layer, a negative polarity friction layer, a positive polarity friction layer, an outer electrode layer, and a rigid support backplate. The inner electrode layer is a conductive fabric adhered to the outer side of the elastic strip 51; the negative polarity friction layer is an FEP film adhered to the inner electrode layer, approximately 30 μm thick; the positive polarity friction layer is an SA / PEI composite film (sodium alginate / polyethyleneimine), a modified biomass material specially formulated for this invention, with a porous micro / nano structure on its surface, readily losing electrons and becoming positively charged; the outer electrode layer is a conductive fabric adhered to the back of the SA / PEI composite film; and the rigid support backplate is a PMMA (polymethyl methacrylate) plate fixed to the inner wall of the outer shell 1, serving as the reaction force support surface for the TENG unit 31.

[0038] The electromagnetic generator (EMG) module includes a mover 21 and a rotor 22, integrated on the central vertical axis of the device. Mover 21: A high-performance neodymium iron boron cylindrical permanent magnet (model N52), fixed inside the top center of the elastic transmission assembly 5, moving synchronously with the inertial mass block 4; Stator: A multi-turn copper coil (model LY5772), fixed at the bottom center of the elastic transmission assembly 5, directly opposite the mover 21 above. Working gap: In a static equilibrium state, the magnet suspends above the coil, maintaining a certain gap to prevent collision and to be in the region of maximum magnetic field gradient.

[0039] The elastic transmission component 5 includes two elastic strips 51 (200 μm thick) made of Kapton film. The two elastic strips 51 are fixed in a cross shape, and their four ends away from the cross fixing point are bent upward and converge towards the center to form an arched cage structure. Kapton material was selected because of its high modulus, high resilience and fatigue resistance.

[0040] The inertial mass block 4 is fixed at the top center of the elastic transmission component 5. Its function is to receive the acceleration of external waves, generate relative displacement, and press the elastic transmission component 5 to adjust the resonance frequency and provide inertial force. It is made of a square stainless steel plate (mass 400g).

[0041] Working principle of the invention:

[0042] This invention utilizes an arched cage structure to achieve a unique "vertical vibration-lateral pressing" decoupling mechanism. Figure 4The mechanical behavior of the device under different states is demonstrated. (i) Static suspension state: When the sea surface is calm, the elastic transmission component 5 is in a pre-compression equilibrium state under the gravity of the inertial mass block 4, the magnet is suspended, and the friction layer of the TENG unit 31 is in a separated state. (ii) Wave-induced state: When the wave impact causes the outer shell 1 to accelerate upward, the inertial mass block 4 moves downward relative to the outer shell 1 (relative compression) due to inertia. This downward pressure forces the elastic transmission component 5 to bend and deform, and its sidewalls expand outward (as shown by the blue arrow in the figure). The lateral expansion of the elastic transmission component 5 provides a strong lateral compressive force, pushing the FEP layer on the inner side of the TENG unit 31 into close contact with the SA / PEI layer fixed on the outer side, resulting in triboelectric charging. At the same time, the magnet moves downward toward the coil, the magnetic flux increases, and an induced current is generated in the EMG module. When the wave recedes or the outer shell 1 accelerates downward, the inertial force reverses, and the inertial mass block 4 rebounds upward. The elastic transmission component 5 returns to its original state, the lateral pressure disappears, the friction layer of the TENG unit 31 separates, and an electrostatic induced current is generated; the magnet moves away from the coil, generating a reverse induced current. Through this mechanism, the single vertical wave motion is decomposed into the "contact-separation" cycle required by the TENG module and the "reciprocating cutting" motion required by the EMG module, and the two are highly coordinated in phase.

[0043] Performance optimization of the TENG module:

[0044] We investigated the effects of the number of TENG units 31 and the geometric parameters of the elastic transmission component 5 on the output.

[0045] Figure 5 The relationship between the amount of transferred charge of the TENG module and the number of parallel units (1 to 4) is shown. This proves that the parallel design of the multi-faceted TENG array can effectively superimpose current output and verifies the effectiveness of the "four-sided lateral pressing" structure.

[0046] Figure 6 A bar graph showing the open-circuit voltage of the TENG module as a function of the external excitation frequency is presented. At 1.5 Hz, the voltage is approximately 100 V; at 2.0 Hz, the voltage peaks at approximately 220 V; and at 2.5 Hz, the voltage drops back to approximately 160 V. This "increase-then-decrease" trend reveals the resonant characteristics of the system. By optimizing the mass of the inertial mass block 4 (400 g) and the arch length of the elastic transmission component 5 (6.0 cm), the natural frequency of the device is tuned to 2.0 Hz, which precisely covers the frequency range of typical ocean waves, thereby significantly improving the energy capture efficiency at low frequencies through resonance.

[0047] Load matching characteristics of EMG modules:

[0048] Figure 7The output power of the EMG module versus load resistance is shown at different amplitudes (20 mm, 30 mm, 40 mm). The curves exhibit a typical "bell-shaped" distribution. Peak power occurs at a load resistance of approximately 60 Ω, and the maximum output power reaches 3.5 mW at an amplitude of 40 mm. Conclusion: The EMG module, as a low-impedance source, can provide milliwatt-level power output, perfectly complementing the high impedance of the TENG module.

[0049] Example 2

[0050] Another specific embodiment of the present invention provides a hybrid nanogenerator, and the preparation process of the SA / PEI composite membrane is as follows:

[0051] Solution preparation: Dissolve 3 g of sodium alginate (SA) and 1 g of polyethyleneimine (PEI) in 96 g of deionized water and stir at 45 °C for 6 hours;

[0052] Crosslinking reaction: Add 0.15 g of epichlorohydrin (ECH) as a crosslinking agent and continue stirring for 12 hours;

[0053] Freeze-drying: The solution is poured into a mold, frozen with liquid nitrogen, and then freeze-dried under vacuum at -50°C for 24 hours to form an aerogel;

[0054] Ion exchange: The aerogel was immersed in a 0.3 mol / L copper chloride solution for ion coordination to enhance its electron-acquiring ability, and then washed with acetone;

[0055] Hot pressing film formation: Hot pressing at 1 MPa pressure for 5 seconds yields a dense SA / PEI film with a thickness of approximately 60 μm.

[0056] The other contents of this embodiment are the same as those in Embodiment 1.

[0057] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A hybrid nanogenerator, comprising a housing (1) and a triboelectric nanogenerator module (3) and an electromagnetic generator module (2) disposed inside the housing (1), characterized in that: It also includes an elastic transmission component (5) and an inertial mass block (4) located at the center inside the outer shell (1). The elastic transmission component (5) includes multiple elastic strips (51). The multiple elastic strips (51) are fixed at intersections, and their multiple ends away from the intersection point bend upwards and converge towards the center to form an arched cage structure. The inertial mass block (4) is fixed at the top center of the elastic transmission component (5). The triboelectric nanogenerator module (3) includes multiple TENG units (31) located around the elastic transmission component (5). The electromagnetic generator module (2) includes a mover (21) and a rotor (22). The mover (21) is fixed inside the top center of the elastic transmission component (5). The stator is fixed at the bottom center of the elastic transmission component (5) and faces the mover (21) above.

2. The hybrid nanogenerator according to claim 1, characterized in that: The outer shell (1) is a fully enclosed box structure.

3. The hybrid nanogenerator according to claim 1, characterized in that: The elastic strip (51) is made of Kapton material.

4. A hybrid nanogenerator according to claim 1, characterized in that: The mover (21) is a high-performance neodymium iron boron cylindrical permanent magnet, and the stator is a multi-turn copper coil.

5. A hybrid nanogenerator according to any one of claims 1-4, characterized in that: The TENG unit (31) includes an inner electrode layer, a negative polarity friction layer, a positive polarity friction layer, an outer electrode layer and a rigid support backplate arranged from the inside out. The inner electrode layer is a conductive fabric pasted on the outside of the elastic strip (51). The negative polarity friction layer is an FEP film pasted on the inner electrode layer. The positive polarity friction layer is an SA / PEI composite film. The outer electrode layer is a conductive fabric pasted on the back of the SA / PEI film. The rigid support backplate is fixed on the inner wall of the outer shell (1).

6. A hybrid nanogenerator according to claim 5, characterized in that: The preparation process of the SA / PEI composite membrane is as follows: Solution preparation: Dissolve 3 grams of sodium alginate (SA) and 1 gram of polyethyleneimine (PEI) in 96 grams of deionized water and stir at 45°C for 6 hours; Crosslinking reaction: 0.15 g of epichlorohydrin (ECH) was added as a crosslinking agent, and stirring was continued for 12 hours; Freeze-drying: The solution was poured into a mold, frozen with liquid nitrogen, and then freeze-dried under vacuum at -50°C for 24 hours to form an aerogel; Ion exchange: The aerogel was immersed in a 0.3 mol / L copper chloride solution for ion coordination to enhance its electron-acquiring ability, and then washed with acetone; Hot pressing film formation: Hot pressing was performed at 1 MPa pressure for 5 seconds to obtain a dense SA / PEI film with a thickness of about 60 μm.

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