Current-transient-enhanced triboelectric nanogenerator for collecting wave energy

Abstract

Disclosed in the present invention is a current-transient-enhanced triboelectric nanogenerator for collecting wave energy, comprising a hollow insulating spherical shell. A plurality of rolling ball type triboelectric nanogenerator assemblies capable of generating current under the drive of waves in any direction are arranged at the middle lower part in a spherical shell cavity, and a triggering assembly is arranged at the upper part in the spherical shell cavity. The plurality of rolling ball type triboelectric nanogenerator assemblies are connected in parallel and then are connected to an electric load outside the spherical shell to form a power supply loop, and the triggering assembly is connected in series on the power supply loop and achieves instantaneous closing and opening of the loop under the drive of waves, thereby instantaneously enhancing the current generated by the plurality of rolling ball type triboelectric nanogenerator assemblies. The present invention solves the problems in the prior art of a failure of normal starting or working of devices caused by excessively low current generated by triboelectric nanogenerators and a failure of continuous current generation due to the impact of motion directions of low-frequency waves.

Description

A Current-Instantaneous Enhanced Triboelectric Nanogenerator for Harvesting Wave Energy Technical Field

[0001] This invention relates to the field of energy harvesting technology, and in particular to a current-intensity enhanced triboelectric nanogenerator for harvesting wave energy. Background Technology

[0002] Currently, wave energy can be harvested using electromagnetic generators and triboelectric nanogenerators. Electromagnetic generators mainly consist of a propeller, magnet, and metal coil. When a wave acts on the propeller, the propeller rotates, causing the metal coil to cut the magnet and generate a potential difference. However, in cases of slow-moving waves or random oscillations, the waves are unlikely to drive the propeller to rotate quickly, resulting in poor efficiency for electromagnetic generators.

[0003] Based on the coupling of triboelectricity and electrostatic induction, when two different materials come into contact under external force, they acquire electrostatic charges of opposite signs (the specific charge sign depends on the material properties). When the two contact surfaces separate under the external force, the potential difference generated by the separation of the two charges drives electrons to flow between the electrodes to which the materials are attached, thereby generating current output. Since waves still have a large oscillation amplitude during low-frequency motion, the above phenomenon is still effective in this case, thus generating a potential difference. Therefore, compared with electromagnetic generators, triboelectric nanogenerators can generate higher output voltage and power during low-frequency wave motion.

[0004] Triboelectric nanogenerators (TGNs) typically exhibit high voltage and low current output during normal operation (e.g., when driven by waves below 3Hz, they can generate hundreds or even thousands of volts, but the current is in the microamplitude range). However, if the current from the TGN is too low, the device may fail to start or operate properly when powered. Furthermore, when harvesting wave energy using a TGN, if the wave's direction cannot separate two materials with different charges, a potential difference cannot be generated, resulting in no current output and causing the device to lose power. For example, patent application number 202210359377 discloses a wave energy harvesting device based on a TGN. When driven by waves aligned with the axis of its cylindrical shell, the undulating wave energy collected by this device, relative to the drive from waves hitting the axis perpendicularly or at a small angle, results in a very small output current, insufficient to meet the operating conditions of the TGN. Therefore, increasing the current output of the TGN and reducing the influence of low-frequency wave motion direction to ensure continuous current generation is crucial.

[0005] Summary of the Invention

[0006] Purpose of the invention: The purpose of this invention is to provide a current-instantaneous enhanced triboelectric nanogenerator for harvesting wave energy, which improves the instantaneous output current while achieving omnidirectional wave energy harvesting.

[0007] Technical Solution: To achieve the above objective, the present invention provides a current-instantaneous enhanced triboelectric nanogenerator for harvesting wave energy, comprising a hollow insulating spherical shell. The lower part of the shell cavity contains multiple sets of rolling ball-type triboelectric nanogenerator components capable of generating current under wave drive in any direction. The upper part of the shell cavity contains a triggering component. The multiple sets of rolling ball-type triboelectric nanogenerator components are connected in parallel and then connected to an external electrical load to form a power supply circuit. The triggering component is connected in series in the power supply circuit and instantaneously closes and opens the circuit with the drive of the wave, thereby instantaneously enhancing the current generated by the multiple sets of rolling ball-type triboelectric nanogenerator components.

[0008] Each group of rolling ball triboelectric nanogenerators is divided into two independent regions, left and right, by grooves, and generates static charge through friction material. One region of each rolling ball triboelectric nanogenerator is connected in parallel with a wire and a spherical shell is led out as electrode A. The other region is connected in parallel with a triggering component and then a spherical shell is led out as electrode B. In the horizontal direction, the axial angle between the grooves of adjacent groups of rolling ball triboelectric nanogenerators is greater than zero.

[0009] In the horizontal direction, the axial angles of the grooves between adjacent groups of rolling ball triboelectric nanogenerators are the same.

[0010] Each set of rolling ball triboelectric nanogenerator components includes a circular base plate made of insulating material and multiple polymer balls. The upper surface of the base plate is divided into left and right regions by grooves. Both regions are covered with a conductive layer, and the conductive layer is covered with a triboelectric layer. The multiple polymer balls roll back and forth between the left and right regions as driven by waves.

[0011] The uppermost rolling ball triboelectric nanogenerator is positioned on the cross section containing the horizontal diameter of the spherical shell.

[0012] The conductive layer is made of double-conductive copper foil, the friction layer is made of polytetrafluoroethylene film, and the polymer spheres are made of nylon.

[0013] The triggering component includes a conductive metal ball that swings freely within the spherical shell cavity and a conductive tube that can contact the conductive metal ball during its swing. The conductive metal ball is fixed to the top of the spherical shell cavity by a suspension component, and the conductive tube is fixed to the inner wall of the spherical shell by a bracket. Both the suspension component and the bracket are made of insulating materials.

[0014] The suspension assembly includes a mounting tube fixed to the top of the inner cavity of the spherical shell. A radial joint bearing that can swing freely at any angle is provided inside the mounting tube. The lower end of the radial joint bearing is connected to the top of the conductive metal ball through a connecting rod. When the spherical shell swings under wave drive, the radial joint bearing swings accordingly, thereby driving the conductive metal ball to swing through the connecting rod.

[0015] The ratio of the inner diameter of the conductive metal ball to that of the conductive tube is in the range of 1:4 to 1:3.

[0016] The bottom of the spherical shell cavity is fixed with a metal balance block for maintaining the balance of the entire triboelectric nanogenerator. The metal balance block has a rotationally symmetric structure with a spherical curved surface at the bottom, the diameter of which is the same as the diameter of the inner cavity of the spherical shell.

[0017] Beneficial effects: The present invention has the following advantages: 1. The present invention utilizes a trigger component connected in series in the power supply circuit composed of multiple sets of rolling ball triboelectric nano-power generation components and electrical loads. Under the drive of waves, it automatically controls the instantaneous closing and opening of the power supply circuit, thereby instantaneously enhancing the current generated by multiple sets of rolling ball triboelectric nano-power generation components and realizing stable power supply for electrical loads with high current demand.

[0018] 2. The conductive metal ball in the triggering component swings freely under the action of the connecting rod and the radial joint bearing, and then the power supply circuit is instantly closed when it touches the conductive tube. The structure is simple, the triggering response is fast, and the reliability is high.

[0019] 3. In this invention, each set of rolling ball triboelectric nanogenerator components is divided into two independent regions, left and right, by grooves. The polymer balls roll back and forth between these two regions with the drive of waves to generate electricity through friction. When the axial angle between the grooves of adjacent generator components is greater than zero, the triboelectric nanogenerator can reduce the influence of the low-frequency wave motion direction on it and achieve omnidirectional collection of low-frequency wave energy. When the axial angle between the grooves of adjacent generator components is greater than zero and the same, the triboelectric nanogenerator reaches the optimal working phase angle. At this time, it can maximize the capture of low-frequency wave energy and achieve efficient omnidirectional energy collection.

[0020] 4. The triboelectric nanogenerator of the present invention has an overall spherical structure, and a balance block is provided at the bottom of the inner cavity of the spherical shell, so that the triboelectric nanogenerator can quickly restore the balance state when it is driven by waves and swings, thereby enhancing the stability of the swing.

[0021] 5. To meet the power supply requirements of different loads, multiple sets of triboelectric nanogenerators can be connected in parallel to further improve the total output power and expand the application range of triboelectric nanogenerators. Attached Figure Description

[0022] Figure 1 is a schematic diagram of the three-dimensional structure of the triboelectric nanogenerator described in this invention;

[0023] Figure 2 is a frontal schematic diagram of the triboelectric nanogenerator described in this invention;

[0024] Figure 3 is a schematic diagram of the structure covered with a conductive layer and a friction layer on the base plate;

[0025] Figure 4 is a schematic diagram of the connection between the bracket and the mounting pipe;

[0026] Figure 5 is a schematic diagram of the wiring connection between the trigger component and the ball-type triboelectric nanogenerator component.

[0027] Figure 6 is a schematic diagram of the working phase angle settings of the three sets of triboelectric nanogenerators in the embodiment;

[0028] Figure 7 is a comparison of the output current intensity of the triboelectric nanogenerator in the embodiment with and without a trigger component under wave drive at a specific angle.

[0029] Figure 8 is a schematic diagram showing the effect of waves of different frequencies on the magnitude of the instantaneous current generated by the triboelectric nanogenerator in the embodiment.

[0030] Figure 9 is a schematic diagram showing the magnitude of the instantaneous current generated by the triboelectric nanogenerator under wave drive at different angles in the embodiment.

[0031] Among them, the spherical shell 1, the rolling ball triboelectric nano-power generation component 2, the base plate 2.1, the conductive layer 2.2, the friction layer 2.3, the polymer ball 2.4, the trigger component 3, the conductive metal ball 3.1, the conductive tube 3.2, the suspension component 3.3, the mounting tube 3.31, the radial joint bearing 3.32, the connecting rod 3.33, the bracket 3.4, and the balance block 4. Detailed Implementation

[0032] The technical solution of the present invention will be described in detail below with reference to the embodiments and accompanying drawings.

[0033] The triboelectric nanogenerator of this invention is a spherical structure that oscillates with wave propulsion and can quickly return to equilibrium. The specific structure is shown in Figures 1 and 2. The exterior is a sealed hollow spherical shell 1, which can be made of transparent acrylic or corrosion-resistant insulating material. The interior of the shell 1 includes multiple sets of rolling ball triboelectric nanogenerator components 2 and a triggering component 3 that instantaneously enhances the current generated by the multiple sets of rolling ball triboelectric nanogenerator components 2. The triggering component 3 is fixed in the upper space inside the shell 1. The multiple sets of rolling ball triboelectric nanogenerator components 2 are independently and parallelly fixed in the middle and lower spaces inside the shell 1, with the uppermost rolling ball triboelectric nanogenerator component 2 positioned at the cross-section of the horizontal diameter of the shell 1. At the bottom of the shell 1, a metal balance block 4 is fixed to maintain the balance of the entire triboelectric nanogenerator. The metal balance block 4 has a rotationally symmetric structure, with a spherical curved surface at the bottom, the diameter of which is the same as the inner wall of the shell 1, and a circular plane at the top with a diameter smaller than that of the shell 1. The trigger component 3 does not come into contact with the multiple sets of rolling ball triboelectric nano-power generation components 2 and the balance block 4.

[0034] Each set of rolling ball triboelectric nanogenerators 2 includes a circular base plate 2.1, which is made of an insulating material, preferably PLA material with low toughness. The upper surface of the base plate 2.1 is divided into two regions, left and right, by grooves. Both regions are covered with a conductive layer 2.2, and each conductive layer 2.2 is covered with a triboelectric layer 2.3. The grooves form an isolation electrode between the two regions, as shown in Figure 3. Multiple polymer balls 2.4 are placed on the triboelectric layer 2.3. Viewed vertically, the grooves on the base plate 2.1 of each set of rolling ball triboelectric nanogenerators 2 exhibit a uniformly distributed angle, that is, these grooves form a uniformly spaced angle distribution on the horizontal plane.

[0035] The width of the groove is much smaller than the diameter of the base plate 2.1 and the diameter of the polymer ball 2.4. The conductive layer 2.2 is made of double-conductive copper foil, the friction layer 2.3 is made of polytetrafluoroethylene film with an uneven nanostructure on its surface, which enhances the triboelectric effect, and the polymer ball 2.4 is made of nylon. The ratio of the sum of the cross-sectional areas of all polymer balls on the base plate to the surface area of ​​the base plate is in the range of 1:4.3-1:5.3.

[0036] As the base plate 2.1 oscillates back and forth with the spherical shell 1 in the waves, the polymer ball 2.4 on the base plate 2.1 rolls back and forth between two areas, rubbing against the friction layer 2.3. When the polymer ball 2.4 rolls against the friction layer 2.3 in the left area, positive charges accumulate on the polymer ball 2.4, and negative charges accumulate on the friction layer 2.3. When the polymer ball 2.4 leaves the left area and rolls to the right area, the potential difference generated by the separation of the two charges drives electrons to flow between the conductive layers 2.2 attached to the friction layer 2.3 in the left area. When the load device connects to the conductive layers 2.2 on both sides of the base plate 2.1 with wires, a closed loop is formed, resulting in current output. According to I = dQ / dt (where Q is the amount of charge), the current I generated at this time is too low due to the long charge release time t. Even if multiple sets of rolling ball triboelectric nano-power generation components 2 are connected in parallel on both sides (i.e., one region of the conductive layer 2.2 of each set is connected by a wire, and the other region of the conductive layer 2.2 is also connected in parallel by a wire), the output current may still cause the equipment to fail to start or work normally when supplying power to the device.

[0037] To increase the current output, this scheme uses trigger component 3 to control the circuit closure. When the amount of accumulated charge on the two friction materials on one side of the base plate 2.1 reaches its maximum, that is, when the potential difference between them reaches its maximum value, the circuit formed by the conductive layers 2.2 on both sides of the base plate 2.1 is instantaneously closed and then instantaneously opened, so that the group of rolling ball triboelectric nano-power generation components 2 generates instantaneous current. According to the formula I=dQ / dt, with the same amount of charge, by shortening the circuit closure time, that is, shortening the charge release time t, instantaneous current can be obtained, thereby enhancing the magnitude of the current output.

[0038] Meanwhile, the grooves on the base plate 2.1 of each ball-type triboelectric nano-power generation component 2 are evenly distributed at an angle. In this way, no matter the direction of wave motion, there will always be one or more sets of ball-type triboelectric nano-power generation components 2 that can generate instantaneous current, thereby maximizing the capture and utilization of wave energy and achieving efficient omnidirectional energy collection.

[0039] The triggering component 3 includes a conductive metal ball 3.1 that swings freely within the spherical shell 1, and a conductive tube 3.2 that contacts the conductive metal ball 3.1 during its swing. The upper end of the conductive metal ball 3.1 is fixed to the top of the inner cavity of the spherical shell 1 via a suspension component 3.3, and the conductive tube 3.2 is fixed to the inner wall of the spherical shell 1 via a bracket 3.4, as shown in Figure 4. Both the suspension component 3.3 and the bracket 3.4 are made of insulating material. The suspension component 3.3 includes a mounting tube 3.31 fixed to the top of the inner cavity of the spherical shell 1. A radial joint bearing 3.32, which can swing freely at any angle, is located inside the mounting tube 3.31. One end of the radial joint bearing 3.32 is connected to the top of the conductive metal ball 3.1 via a connecting rod 3.33. When the spherical shell 1 swings, the radial joint bearing 3.32 swings accordingly, which in turn drives the conductive metal ball 3.1 to swing via the connecting rod 3.33. The ratio of the inner diameter of the conductive metal ball 3.1 to that of the conductive tube 3.2 is in the range of 1:4 to 1:3. The conductive metal ball 3.1 is suspended in the cavity of the conductive tube 3.2 by the suspension assembly 3.3, and can swing back and forth in the cavity of the conductive tube 3.2 under the drive of the radial joint bearing 3.32, and touch its inner wall.

[0040] As shown in Figure 5, the wiring connection between the trigger component 3 and the multiple sets of ball-type triboelectric nanogenerator components 2 is as follows: The conductive layer 2.2 of one region of each set of ball-type triboelectric nanogenerator components 2 is connected to the conductive tube 3.2 using wires; then, the conductive layer 2.2 of another region of each set of ball-type triboelectric nanogenerator components 2 is connected in parallel using wires, and the spherical shell 1 is led out as the A electrode of the triboelectric nanogenerator; a wire is wound around the conductive metal ball 3.1, and the spherical shell 1 is led out as the B electrode of the triboelectric nanogenerator; when the conductive metal ball 3.1 touches the inner wall of the conductive tube 3.2, a closed loop is formed between the A electrode and the B electrode to supply power to the electrical load (the generated electrical energy can also be stored in the battery pack after circuit processing); when the conductive metal ball 3.1 does not touch the inner wall of the conductive tube 3.2, the loop formed between the A electrode and the B electrode is open. When the wave amplitude is ±c (cm) and the frequency is f (Hz), the conductive metal ball 3.1 will break twice within one oscillation cycle of the oscillation with an amplitude of ±c, that is, the time scale of a single break is 0.5f.

[0041] Example 1

[0042] In this embodiment, the inner diameter of the spherical shell 1 in the triboelectric nanogenerator is 120 mm, the wall thickness is 2 mm, the balance block 4 is made of ferrous metal and weighs 150 g, and the conductive metal ball 3.1 in the trigger assembly 3 has a diameter of 10 mm and the conductive tube 3.2 has a diameter of 30 mm. The rolling ball type triboelectric nanogenerator assembly 2 includes three sets, in which the diameters of the base plates are 120 mm, 114 mm, and 100 mm, respectively; the diameters of the polymer balls are all 5 mm, and the quantities are 110, 104, and 92, respectively; the working phase angle (the angle between the grooves on adjacent base plates 2.1) is 60°, as shown in Figure 6. Under wave drive, the triboelectric nanogenerator obtained the following test results.

[0043] Figure 7 shows a comparison of the output current intensity of the triboelectric nanogenerator in this embodiment under the drive of a wave at a specific angle (amplitude ±7cm, frequency 1Hz, along the horizontal direction), with and without the aforementioned triggering component 3. As shown in the figure, when the conductive metal ball 3.1 in the triggering component 3 collides with the conductive tube 3.2 through its oscillation, a closed loop is formed between electrodes A and B. The charge accumulated in a single instance for a duration of 0.5f reaches its maximum value, creating a maximum potential difference. At the instant the loop closes, the output current is instantaneously enhanced. Simultaneously, since the phase angle of the three sets of rolling ball triboelectric nanogenerator components 2 in the triboelectric nanogenerator is 60°, regardless of the direction of the wave drive, at least one set of rolling ball triboelectric nanogenerator components will accumulate charge through rolling friction, generating an instantaneous current.

[0044] Figure 8 shows the effect of waves of different frequencies on the instantaneous current generated by the triboelectric nanogenerator under the horizontal wave drive with an amplitude of ±7cm in this embodiment. As can be seen from the figure, a high instantaneous current can be generated at different frequencies. The higher the frequency, the greater the average instantaneous current output.

[0045] Figure 9 illustrates the instantaneous current generated by the triboelectric nanogenerator in this embodiment under wave drive at different angles on the horizontal plane with an amplitude of ±7cm and a frequency of 1Hz. Combining Figures 6 and 9, it can be seen that the topmost rolling ball triboelectric nanogenerator component has the largest base area and the most polymer balls compared to the other two groups. When wave drive is used with a direction perpendicular to the groove direction in each layer of the generator component, the instantaneous current generated by the topmost generator component is the largest. Therefore, based on a triboelectric nanogenerator with a phase angle of 60° for the three-layer generator components, when the wave drive direction is perpendicular to the groove direction in the topmost rolling ball triboelectric nanogenerator component and the angle between this angle and the groove directions in the second and third rolling ball triboelectric nanogenerator components is 30°, the instantaneous current generated by the triboelectric nanogenerator as a whole is the largest. That is, 90° (270°) on the horizontal plane is the maximum output angle of the triboelectric nanogenerator. When the wave drive direction is parallel to the groove orientation of the uppermost rolling ball triboelectric nanogenerator component 2, and the angle between this direction and the groove orientations of the second and third rolling ball triboelectric nanogenerator components is 30°, the instantaneous current generated by the triboelectric nanogenerator is minimized; that is, 0° (180°) on the horizontal plane is the minimum output angle of the triboelectric nanogenerator. Simultaneously, the triboelectric nanogenerator maintains a stable instantaneous current output between 0° and 90°. Therefore, the triboelectric nanogenerator described in this invention can stably output a momentarily enhanced current under wave drive at any angle.

Claims

1. A current-instantaneous enhanced triboelectric nanogenerator for harvesting wave energy, characterized in that, The device includes a hollow insulating spherical shell (1). The lower part of the cavity of the spherical shell (1) is provided with multiple sets of rolling ball triboelectric nano-power generation components (2) that can generate current under wave drive in any direction. The upper part of the cavity of the spherical shell (1) is provided with a trigger component (3). The multiple sets of rolling ball triboelectric nano-power generation components (2) are connected in parallel and then connected to the external electrical load of the spherical shell (1) to form a power supply circuit. The trigger component (3) is connected in series on the power supply circuit and realizes the instantaneous closing and opening of the circuit with the drive of the wave, thereby instantaneously enhancing the current generated by the multiple sets of rolling ball triboelectric nano-power generation components (2).

2. The current-instantaneous enhanced triboelectric nanogenerator for harvesting wave energy according to claim 1, characterized in that, Each group of rolling ball triboelectric nanogenerators (2) is divided into two independent regions, left and right, by grooves, and generates static charge through friction material. One region of each rolling ball triboelectric nanogenerator (2) is connected in parallel by wires and a spherical shell (1) is led out as the A electrode. The other region is connected in parallel by wires and connected in series with the trigger component (3) and a spherical shell (1) is led out as the B electrode. In the horizontal direction, the axial angle between the grooves of the adjacent groups of rolling ball triboelectric nanogenerators (2) is greater than zero.

3. The current-instantaneous enhanced triboelectric nanogenerator for harvesting wave energy according to claim 2, characterized in that, In the horizontal direction, the axial angle between the grooves of the adjacent groups of rolling ball triboelectric nanogenerators (2) is the same.

4. The current-instantaneous enhanced triboelectric nanogenerator for harvesting wave energy according to claim 2, characterized in that, Each set of rolling ball triboelectric nano-power generation components (2) includes a circular base plate (2.1) made of insulating material and multiple polymer balls (2.4). The upper surface of the base plate (2.1) is divided into left and right regions by grooves. Both regions are covered with a conductive layer (2.2). The conductive layer (2.2) is covered with a triboelectric layer (2.3). The multiple polymer balls (2.4) roll back and forth between the left and right regions as driven by waves.

5. The current-instantaneous enhanced triboelectric nanogenerator for harvesting wave energy according to claim 4, characterized in that, The uppermost rolling ball triboelectric nanogenerator (2) is located on the cross section of the horizontal diameter of the spherical shell (1).

6. The current-instantaneous enhanced triboelectric nanogenerator for harvesting wave energy according to claim 4, characterized in that, The conductive layer (2.2) is made of double-conductive copper foil, the friction layer (2.3) is made of polytetrafluoroethylene film, and the polymer spheres (2.4) are made of nylon.

7. The instantaneously enhanced triboelectric nanogenerator for harvesting wave energy according to claim 1, characterized in that, The triggering component (3) includes a conductive metal ball (3.1) that swings freely inside the cavity of the spherical shell (1) and a conductive tube (3.2) that can touch the conductive metal ball (3.1) during its swing. The conductive metal ball (3.1) is fixed to the top of the cavity of the spherical shell (1) by a suspension component (3.3), and the conductive tube (3.2) is fixed to the inner wall of the spherical shell (1) by a bracket (3.4). Both the suspension component (3.3) and the bracket (3.4) are made of insulating materials.

8. The current-instantaneous enhanced triboelectric nanogenerator for harvesting wave energy according to claim 7, characterized in that, The suspension assembly (3.3) includes a mounting tube (3.31) fixed on the top of the inner cavity of the spherical shell (1). The mounting tube (3.31) is provided with a radial joint bearing (3.32) that can swing freely at any angle. The lower end of the radial joint bearing (3.32) is connected to the top of the conductive metal ball (3.1) through a connecting rod (3.33). When the spherical shell (1) swings under wave drive, the radial joint bearing (3.32) swings accordingly, and then drives the conductive metal ball (3.1) to swing through the connecting rod (3.33).

9. The current-instantaneous enhanced triboelectric nanogenerator for harvesting wave energy according to claim 7, characterized in that, The ratio of the inner diameter of the conductive metal ball (3.1) to that of the conductive tube (3.2) is in the range of 1:4 to 1:

3.

10. The instantaneously enhanced triboelectric nanogenerator for harvesting wave energy according to claim 1, characterized in that, The bottom of the cavity of the spherical shell (1) is fixed with a metal balance block (4) for maintaining the balance of the entire triboelectric nanogenerator. The metal balance block (4) has a rotationally symmetric structure and a spherical curved surface at the bottom. The diameter of the curved surface is the same as the diameter of the cavity of the spherical shell (1).

Images