A Degradable Frictional Nanogenerator with High Output Power, Its Preparation Method and Application

Abstract

The present invention discloses a degradable triboelectric nanogenerator with high output power, and its preparation method and application. The preparation method of the triboelectric nanogenerator comprises the following steps: from top to bottom, an acrylic substrate, an electrode and the prepared L-CNF paper are sequentially assembled into the positive triboelectric electrode of the triboelectric nanogenerator, and similarly, a bacterial cellulose grafted with chitosan (BC-CS) film, an electrode and an acrylic substrate are sequentially assembled into the negative triboelectric electrode of the triboelectric nanogenerator, and then the positive triboelectric electrode and the negative triboelectric electrode are adhesively assembled into a triboelectric nanogenerator. The triboelectric nanogenerator prepared by the present invention has good electrical output performance and can be used in electronic devices, such as LED lights, energy storage appliances, flexible pressure sensors, implantable medical devices, bionic robots, medical real-time monitoring devices, etc.

Description

Technical Field

[0001] The present invention relates to the field of manufacturing triboelectric nanogenerators and flexible pressure sensors, and particularly relates to a degradable triboelectric nanogenerator with high output power, a preparation method thereof, and an application thereof. Background Art

[0002] In recent years, with the proposal of a series of concepts of flexible wearable devices and the application of products, how to provide safer, more convenient, and continuous energy for the devices has become an urgent problem to be solved. The triboelectric nanogenerator (TENG) is a newly emerging green energy device that can obtain energy from the surrounding environment, such as human walking, wind flow, water flow, and any other tiny mechanical movements (such as breathing, blinking, and heartbeat, etc.), causing the two friction electrodes of the TENG to contact, rub, or collide with each other, and converting mechanical energy into electrical energy by using the coupling effect of triboelectrification and electrostatic induction. Since the TENG was first reported in 2012, it has always been regarded as a powerful energy device, and due to its series of advantages such as light weight, high safety, environmental friendliness and sustainability, high output performance, and unrestricted material selection, it has broad application prospects. In recent years, the TENG has received a large amount of research in aspects such as collecting ocean energy, water droplet energy, wind energy, and self-powered sensors due to its unique self-powered system that can ensure continuous and reliable power supply for various devices (such as wearable electronic devices, sensors, smartphones, and medical devices, etc.).

[0003] Green and environmentally friendly energy technologies are crucial for reducing environmental pollution caused by fossil fuels. The degradable-based triboelectric nanogenerator (DB-TENG) is expected to promote the progress of a new generation of green energy technologies and effectively avoid the pollution and harm brought by heavy metals and hard-to-degrade plastics as triboelectric layer materials.

[0004] In addition, currently, the TENG still has deficiencies such as low energy conversion efficiency, insufficient output power, and unstable pulsed electrical signals, which also become difficult problems to be solved urgently in the practical application of the TENG. Among them, the electrical output performance of the TENG (such as output power and output current) mainly depends on the amount of charge transfer between the friction layer materials, and the amount of charge transfer is closely related to the electronegativity of the surface materials constituting the friction layer. Different groups with different functional groups exhibit different electronegativities, that is, their abilities to gain and lose electrons are different. Since the composition of the friction layer materials selected for the currently degradable triboelectric nanogenerator is single, the difference in the abilities of the friction layers to gain and lose electrons is small, the amount of charge transfer is low, and ultimately the electrical output performance of the triboelectric nanogenerator is not high.

[0005] In summary, developing a degradable and high-output-power triboelectric nanogenerator is of great practical significance for further promoting the development of energy supply technologies in advanced fields such as wearable electronic devices, implantable medical electronic devices, and flexible pressure sensors. Summary of the Invention

[0006] The primary object of the present invention is to overcome the disadvantages and deficiencies of the prior art and provide a preparation method for a degradable and high-output-power triboelectric nanogenerator.

[0007] Another object of the present invention is to provide a degradable and high-output-power triboelectric nanogenerator prepared by the above method.

[0008] A further object of the present invention is to provide the application of the degradable and high-output-power triboelectric nanogenerator.

[0009] The object of the present invention is achieved by the following technical solutions:

[0010] A preparation method for a degradable and high-output-power triboelectric nanogenerator includes the following steps:

[0011] (1) Prepare L-CNF paper

[0012] Place bamboo chips in an NaOH solution, perform alkali treatment at 90 ± 5 °C, then wash with water, soak in water, and then perform high-pressure homogenization treatment to obtain an L-CNF dispersion; finally, adjust the concentration of the L-CNF dispersion to 0.5 - 0.8 wt%, and form a paper by suction filtration, and dry to obtain L-CNF paper (as the positive friction material of the triboelectric nanogenerator);

[0013] (2) Prepare BC-CS film

[0014] ① Wash granular bacterial cellulose (BC) with water and soak it in an NaOH solution to remove bacterial cells and residual impurities, then add an acetic acid solution for neutralization, and wash with water until the filtrate is neutral to obtain purified BC; then disperse the purified BC into a BC suspension with a beater;

[0015] ② Add an oxidant to the BC suspension, perform oxidation treatment at 50 ± 5 °C under light-shielded conditions, after the oxidation treatment is completed, centrifuge and wash, and then redisperse with water to obtain an oxidized BC suspension;

[0016] ③ Immerse the oxidized BC suspension in an acetic acid solution containing chitosan (CS), and react at 60 ± 5 °C to successfully graft chitosan onto the oxidized BC. After the reaction, centrifuge and wash to obtain BC-CS; then ultrasonically disperse BC-CS in water to obtain a BC-CS suspension; finally, filter the BC-CS suspension into a film and dry to obtain a BC-CS film (the modified BC film serves as the negative friction material of the triboelectric nanogenerator).

[0017] (3) Assemble the triboelectric nanogenerator

[0018] From top to bottom, sequentially assemble the acrylic substrate, the electrode, and the L-CNF paper prepared in step (1) into the positive friction electrode of the triboelectric nanogenerator. At the same time, sequentially assemble the BC-CS film, the electrode, and the acrylic substrate prepared in step (2) into the negative friction electrode of the triboelectric nanogenerator. Then, paste and assemble the positive friction electrode and the negative friction electrode of the triboelectric nanogenerator to form a triboelectric nanogenerator.

[0019] The concentration of the NaOH solution described in step (1) is 1.0 - 1.5% by mass; preferably 1.0% by mass.

[0020] The mass ratio of the bamboo chips to the NaOH solution described in step (1) is 1:5 - 15; preferably 1:10.

[0021] The size of the bamboo chips described in step (1) can be adjusted according to actual needs, and preferably, the bamboo chips are 1.2 cm * 1.2 cm.

[0022] The alkali treatment time described in step (1) is 1 - 3 h; preferably 2 h.

[0023] The soaking time described in step (1) is 1 - 3 days; preferably 2 days.

[0024] The high-pressure homogenization described in step (1) is carried out using a high-pressure microfluidic homogenizer.

[0025] The high-pressure homogenization treatment conditions described in step (1) are: the pressure level is 10000 psi, and the number of treatment times is 8 - 10 times (preferably 10 times).

[0026] The concentration of the L-CNF dispersion after high-pressure homogenization treatment described in step (1) is preferably 2 - 3% by mass; more preferably 2% by mass.

[0027] The adjustment of the concentration of the L-CNF dispersion described in step (1) is preferably adjusted to a concentration of 0.7 wt%.

[0028] The suction filtration described in steps (1) and ③ is vacuum suction filtration using a fritted funnel.

[0029] The filter membrane used for the suction filtration described in steps (1) and ③ has a diameter of 4 cm and a pore size of 0.22 μm.

[0030] The drying method described in steps (1) and ③ is drying in a drying cylinder, and the drying temperature is preferably 80 ± 5 °C.

[0031] The concentration of the NaOH solution described in step ① is 0.1 - 0.3 mol / L; preferably 0.1 mol / L.

[0032] The soaking time described in step ① is 1 - 3 h; preferably 1 h.

[0033] The concentration of the acetic acid solution described in step ① is 0.5 - 0.8% by volume; preferably 0.5% by volume.

[0034] The pulper described in step ① is preferably a plant fiber nano - pulper.

[0035] The concentration of the BC suspension described in step ① is 0.3 - 0.5% by mass; preferably 0.4% by mass.

[0036] The oxidant described in step ② is at least one of sodium periodate, sodium ferrate, sodium hypochlorite, potassium permanganate, and hydrogen peroxide; preferably sodium periodate.

[0037] The dosage of the oxidant described in step ② is calculated according to its final concentration in the reaction system of 0.1 - 0.25 mol / L; preferably calculated according to its final concentration in the reaction system of 0.25 mol / L.

[0038] The oxidation treatment time described in step ② is 2.5 - 3.0 h; preferably 3.0 h.

[0039] The conditions for the centrifugal washing described in step ② are: centrifugal washing at a speed of 8000 rpm; preferably centrifugal washing 5 - 8 times at a speed of 8000 rpm.

[0040] The concentration of the oxidized BC suspension described in step ② is 0.5 - 2.0% by mass; preferably 2.0% by mass.

[0041] The concentration of chitosan in the acetic acid solution containing chitosan (CS) described in step ③ is 0.02 - 0.03 g / mL; preferably 0.02 g / mL.

[0042] The acetic acid solution containing chitosan (CS) described in step ③ is preferably obtained by the following method: adding chitosan (CS) powder into the acetic acid solution and stirring to dissolve it at 60 ± 5 °C to obtain the acetic acid solution containing chitosan (CS).

[0043] The concentration of the acetic acid solution is 0.2 - 0.3% by volume percentage; preferably 0.2% by volume percentage.

[0044] The chitosan (CS) is chitosan with a viscosity of 200 - 400 mPa·s (medium viscosity).

[0045] The mass ratio of the oxidized BC to chitosan described in step ③ is 1:25 - 30; preferably 1:25.

[0046] The concentration of the BC-CS suspension described in step ③ is 0.5 - 2.0% by mass percentage; preferably 2.0% by mass percentage.

[0047] The reaction time described in step ③ is 2 - 3 h; preferably 2 h.

[0048] The power of the ultrasonic wave described in step ③ is 800 W and the frequency is 20 kHz.

[0049] The electrodes described in step (3) are all aluminum sheets.

[0050] A degradable high-output power triboelectric nanogenerator is prepared by the method described in any one of the above.

[0051] The application of the degradable high-output power triboelectric nanogenerator in the preparation of electronic devices. This triboelectric nanogenerator can supply power to electronic devices, etc., thus providing a new selection method for the power source problem of electronic devices.

[0052] The electronic devices include LED lights (the triboelectric nanogenerator can be used to light the LED lights), energy storage electrical appliances (the triboelectric nanogenerator can be used to connect capacitors), flexible pressure sensors, implantable medical devices, bionic robots, or medical real-time monitoring devices, etc.

[0053] The flexible pressure sensor includes a flexible wearable sensor; further preferably a self-powered flexible wearable sensor.

[0054] The medical real-time monitoring device includes a medical real-time monitoring device for detecting human limb movement, pulse, and / or heart rate, etc.

[0055] A degradable high-output power self-powered pressure sensor includes the above triboelectric nanogenerator, a first electrode, a flexible pressure sensing layer, a second electrode, and an acrylic substrate arranged from top to bottom.

[0056] The described flexible pressure sensing layer is preferably cellulose-based conductive paper; more preferably, it is cellulose-based conductive paper prepared according to Chinese Patent (ZL2021 10323518.9).

[0057] Both the first electrode and the second electrode are copper sheets.

[0058] The present invention has the following advantages and effects compared with the prior art:

[0059] (1) The triboelectric nanogenerator in the present invention can convert mechanical energy into electrical energy by collecting physical and mechanical forces such as pressing. The positive and negative triboelectric materials of the triboelectric nanogenerator are lignin nanofibrillated cellulose (L-CNF) and chitosan-grafted bacterial cellulose (BC-CS) respectively, that is, both electrode materials are natural polymer materials that are green, environmentally friendly, degradable, and recyclable, with low raw material costs. In addition, since most of the lignin is retained in lignin nanofibrillated cellulose (L-CNF), the groups it contains (such as hydroxyl groups, carboxyl groups, etc.) can endow L-CNF paper with higher electron absorption / gaining ability. Combined with chitosan-grafted bacterial cellulose (BC-CS), due to the presence of amino groups on it, it endows the BC-CS film with higher electron-losing ability. Both of these will effectively increase the electrical output performance of the triboelectric nanogenerator. And because more hydrophobic lignin is covalently bonded to the surface of nanofibrillated cellulose, L-CNF has properties such as lower water penetration and absorption, higher water contact angle, and wet mechanical strength, enabling it to maintain good electrical output performance under certain external forces such as bending, twisting, and folding, so as to ensure a longer service life of the triboelectric nanogenerator.

[0060] (2) The preparation and assembly process of the triboelectric nanogenerator obtained in the present invention is simple, does not involve relatively complex processes such as electroplating, spraying, or magnetron sputtering, and to a certain extent, it also saves costs and has high production efficiency.

[0061] (3) The open-circuit voltage of the triboelectric nanogenerator obtained in the present invention can reach up to 150V at most, the maximum short-circuit current is 12 μA, and the output power density can reach 199 mW·m -2 , that is, its electrical output performance is relatively excellent. The voltage sensitivity of the self-powered capacitive pressure sensor thus compounded is 20 mW·kPa -1 , far higher than the existing technical level. In addition, it can be used to light LED lights, connect energy storage electrical appliances such as capacitors for power supply, and power electronic devices such as flexible pressure sensors and implantable medical devices, thus providing a new selection method for the power supply technology of various electronic devices, which is of great significance for the development of self-powered flexible electronics.

[0062] (4) The electrical output performance of the triboelectric nanogenerator obtained in the present invention can be regulated according to the lignin content in L-CNF and the content of successfully grafted chitosan (CS) in BC-CS, that is, the electrical output performance of the triboelectric nanogenerator prepared in the present invention is adjustable, which provides more possibilities for the comprehensive development of triboelectric nanogenerators. Description of the Drawings

[0063] Figure 1 It is a schematic structural diagram of the composite self-powered capacitive pressure sensor in the present invention (in the figure, 1: acrylic substrate; 2: aluminum sheet; 3: lignin nanofibrillated cellulose paper (L-CNF paper); 4: bacterial cellulose grafted chitosan film (BC-CS film); 5: copper sheet; 6: cellulose-based conductive paper). Detailed Description of the Invention

[0064] The present invention will be further described in detail below in conjunction with the embodiments, but the embodiments of the present invention are not limited thereto. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the technical field. The test methods without specific experimental conditions in the following examples are usually carried out according to conventional experimental conditions. Unless otherwise specified, the reagents and raw materials used in the present invention can be obtained commercially.

[0065] The moso bamboo slices involved in the embodiments of the present invention are purchased from Shandong Jianghe Paper Co., Ltd.; sodium hydroxide and acetic acid are purchased from Guangzhou Chemical Reagent Factory (China); granular bacterial cellulose (particle size 0.5 - 0.8 cm) (BC) is purchased from Hainan Yide Food Co., Ltd.; chitosan (medium viscosity, 200 - 400 mPa·s) is purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.

[0066] The acrylic substrate involved in the embodiments of the present invention is purchased from Shenzhen Hongkunda Technology Co., Ltd.

[0067] Example 1

[0068] (1) Preparation of lignin nanocellulose (L-CNF) paper: Weigh a certain mass of bamboo chips (1.2 cm * 1.2 cm) and place them in a 1 wt% NaOH solution (the mass ratio of bamboo chips to NaOH solution is 1:10). Stir at 90 °C for 2 h to remove the extractives. Thoroughly wash the residue with distilled water until a clear liquid is obtained. Immerse the bamboo chip residue in distilled water for 2 days, maintaining the mass fraction of the bamboo chip residue in the system at 2 wt%. Then, use a high-pressure microfluidizer (Nano Disperser NLM 100, Ilshin Autoclave, origin: South Korea) to process it 10 times at a pressure level of 10,000 psi to obtain an L-CNF dispersion. Adjust the concentration of the L-CNF dispersion to 0.7 wt% by adding water and stir for 12 h to obtain a homogeneous dispersion. Pour the L-CNF dispersion into a sintered glass funnel and use the "paper-making method" to vacuum filter it into paper (the filter membrane diameter is 4 cm and the pore size is 0.22 μm). Then, cover both sides of the wet paper with filter paper and place it on a roll dryer at 80 °C for drying. After drying is completed, peel it off to obtain L-CNF paper (basis weight is 45 ± 2 g·m -2 ), and set aside for use.

[0069] (2) Preparation of bacterial cellulose grafted chitosan (BC-CS) film:

[0070] ① Wash granular bacterial cellulose (BC) several times with distilled water, and then soak it in a boiling 0.1 mol·L -1 NaOH solution for 1 h to remove bacterial cells and residual impurities, obtaining purified BC. Then neutralize it with a 0.5% (v / v) acetic acid solution, and then wash it repeatedly with distilled water until the pH of the filtrate is neutral. Use a plant fiber nanomill (UH-60, purchased from China United Biotechnology Co., Ltd.) (about process for 5 - 10 min, the same below) to first disperse the purified BC into a 0.4 wt% BC suspension.

[0071] ② Take 100 mL of BC suspension (0.4 wt%) and place it in a round-bottom flask. Add sodium periodate, an oxidant with a final concentration of 0.10 mol·L -1 , and react in a 50 °C constant temperature water bath for 3.0 h (shielded from light). After the reaction is completed, centrifuge and wash 5 times at a speed of 8000 rpm to remove the residual oxidant, and finally add water to prepare an oxidized BC suspension (concentration is 2 wt%).

[0072] ③ Take 10.0 g of chitosan powder and place it in an acetic acid solution (2% (v / v), 500 mL). Stir at 60 °C for 1 h to obtain a chitosan solution. Immerse the oxidized BC suspension (with a volume of 20 mL, a concentration of 2 wt%, and a mass ratio to chitosan of 1:25) in the chitosan solution and continuously stir at 60 °C for 2 h to successfully graft chitosan onto the oxidized BC. After oxidation, centrifuge and wash several times to obtain BC-CS. Disperse BC-CS in 100 mL of distilled water and sonicate (sonication power is 800 W, sonication frequency is 20 kHz) for a period of time to form a uniform suspension. Pour the BC-CS suspension into a sintered glass funnel and vacuum filter it into a film (the diameter of the filter membrane is 4 cm, and the pore size is 0.22 μm). Then, cover both sides of the wet paper sheet with filter paper and place it on a roll dryer at 80 °C for drying. After drying, peel it off to obtain a BC-CS film (with a thickness of 100 ± 20 μm) for standby.

[0073] ④ What was measured was the chitosan content in the grafted BC-CS dispersion

[0074] The measurement method was referred to the literature (“《Characteristics of antimicrobial fibers prepared with wood periodate oxycellulose》https: / / doi.org / 10.1016 / j.carbpol.2008.02.010”). Among them, the content (%) of chitosan (CS) successfully grafted onto bacterial cellulose (BC) was calculated by the following formula: CS content (%) = N% / 14.007 * 166.74, where 166.74 / 14.007 is the ratio of the relative molecular mass of chitosan to the mass of nitrogen element (N). The calculated chitosan content grafted onto BC was 10.5%.

[0075] (3) Assembly and Performance Study of L-CNF / BC-CS-Based Triboelectric Nanogenerator (TENG): Take a piece of L-CNF paper prepared in step (1) (with a size of 20 mm * 20 mm * 0.10 mm), paste a layer of aluminum sheet (with a size of 20 mm * 20 mm * 0.35 mm) on it, lead it out with a copper wire (with a length of 500 mm and a diameter of 0.10 mm), and then fix it on an acrylic substrate (with a size of 20 mm * 20 mm * 2.0 mm) as the positive friction electrode of the triboelectric nanogenerator; Paste a layer of aluminum sheet (with a size of 20 mm * 20 mm * 0.35 mm) on the BC-CS film prepared in step (2) (with a size of 20 mm * 20 mm * 0.10 mm), lead it out with a copper wire (with a length of 500 mm and a diameter of 0.10 mm), and fix it on another acrylic substrate (with a size of 20 mm * 20 mm * 2.0 mm) as the negative friction electrode of the triboelectric nanogenerator. Finally, paste the positive friction electrode and the negative friction electrode together to complete the assembly of the L-CNF / BC-CS-based triboelectric nanogenerator (the specific structure of the L-CNF / BC-CS-based triboelectric nanogenerator is as shown in the upper half of Figure 1 Figure 1, that is, a total of six layers marked as "1, 2, 3, 4, 2, 1" in the figure; Among them, the copper wire is connected to the aluminum sheet and led out). The operations of the electrical output performance such as the open-circuit voltage and short-circuit current of the triboelectric nanogenerator are carried out according to the references: "Natural lignocellulosic nanofibrils as tribonegative materials for self-powered wireless electronics" (https: / / doi.org / 10.1016 / j.nanoen.2022.107337) and "Cellulose II Aerogel-Based Triboelectric Nanogenerator" (DOI: 10.1002 / adfm.202001763).

[0076] (4) Assembly and Performance Study of the Composite Self-Powered Capacitive Pressure Sensor: Sequentially bond a copper sheet, a cellulose-based conductive paper (a flexible conductive paper prepared according to Example 1 of the Chinese patent "ZL 2021 1 0323518.9, titled A Flexible Conductive Paper Loaded with Silver Nanowires and Its Preparation Method and Application"), a copper sheet, and an acrylic substrate to the bottom of the L-CNF / BC-CS-based triboelectric nanogenerator to obtain a composite self-powered capacitive pressure sensor (the specific structure of this composite self-powered capacitive pressure sensor is as shown in Figure 1As shown). The sensitivity of the pressure sensor was detected according to the reference document "Siloxene / PVDF Composite Nanofibrous Membrane for High-Performance Triboelectric Nanogenerator and Self-Powered Static and Dynamic Pressure Sensing Applications" (DOI: 10.1002 / adfm.202202145).

[0077] Example 2

[0078] (1) Preparation of lignin nanofibrillated cellulose (L-CNF) paper: Weigh a certain mass of bamboo chips (1.2 cm * 1.2 cm) and place them in a 1 wt% NaOH solution (the mass ratio of bamboo chips to NaOH solution is 1:10). Stir at 90 °C for 2 h to remove the extractives. Thoroughly wash the residue with distilled water until a clear liquid is obtained. Immerse the bamboo chip residue in distilled water for 2 days, maintaining the mass fraction of the bamboo chip residue in the system at 2 wt%. Then, use a high-pressure microfluidizer (Nano Disperser NLM 100, Ilshin Autoclave, origin: South Korea) to process it 10 times at a pressure level of 10000 psi to obtain an L-CNF dispersion. Adjust the L-CNF dispersion to a concentration of 0.7 wt% and stir for 12 h to obtain a homogeneous dispersion. Pour the L-CNF dispersion into a sintered glass funnel and use the "paper-making method" to vacuum filter it into paper (filter membrane diameter is 4 cm, pore size is 0.22 μm). Then, cover both sides of the wet paper sheet with filter paper and place it on a roll dryer at 80 °C for drying. After drying is completed, peel it off to obtain L-CNF paper (basis weight is 45 ± 2 g·m -2 ), and set aside for later use.

[0079] (2) Preparation of bacterial cellulose grafted chitosan (BC-CS) film:

[0080] ① Wash the granular bacterial cellulose (BC) several times with distilled water, and then soak it in a 0.1 mol·L -1 boiling NaOH solution for 1 h to remove bacterial cells and residual impurities, obtaining purified BC. Then, neutralize it with a 0.5% (v / v) acetic acid solution, and then wash it repeatedly with distilled water until the pH of the filtrate is neutral. Use a plant fiber nanomill (UH-60, purchased from China United Biotechnology Co., Ltd.) to first disperse the purified BC into a 0.4 wt% BC suspension.

[0081] ② Take 100 mL of BC suspension (0.4 wt%) and place it in a round-bottom flask. Add sodium periodate, an oxidant with a final concentration of 0.15 mol·L -1 and react at 50 °C in a constant-temperature water bath for 3.0 h (shielded from light). After the reaction, centrifuge and wash 5 times at a speed of 8000 rpm to remove the residual oxidant. Finally, add water to prepare an oxidized BC suspension (concentration 2 wt%).

[0082] ③ Take 10.0 g of chitosan powder and place it in an acetic acid solution (2% (v / v), 500 mL). Stir at 60 °C for 1 h to obtain a chitosan solution. Immerse the oxidized BC suspension (usage amount 20 mL, concentration 2 wt%) in the chitosan solution and continuously stir at 60 °C for 2 h to successfully graft chitosan onto the oxidized BC. After oxidation, centrifuge and wash several times to obtain BC-CS. Disperse BC-CS in 100 mL of distilled water and sonicate (sonication power 800 W, sonication frequency 20 kHz) for a period of time to form a uniform suspension. Pour the BC-CS suspension into a sintered glass funnel and vacuum filter it into a film (filter membrane diameter 4 cm, pore size 0.22 μm). Then, cover both sides of the wet paper sheet with filter paper and place it on a roller dryer at 80 °C for drying. After drying, peel it off to obtain a BC-CS film (thickness 100 ± 20 μm) for standby.

[0083] ④ Determine and calculate the chitosan content grafted onto BC according to the method of Example 1. Among them, the chitosan (CS) content (%) grafted onto bacterial cellulose (BC) is calculated by the following formula: CS content (%) = N% / 14.007 * 166.74, where 166.74 / 14.007 is the ratio of the relative molecular mass of chitosan to the mass of nitrogen element. The calculated chitosan content grafted onto BC is 12.1%.

[0084] (3) Assembly and performance study of L-CNF / BC-CS based friction nanogenerator (TENG): Take a piece of L-CNF paper (20mm*20mm*0.10mm) prepared in step (1), paste a layer of aluminum sheet (20mm*20mm*0.35mm) on it, lead it out with a copper wire (length 500mm, diameter 0.10mm), and then fix it on an acrylic substrate (20mm*20mm*2.0mm) as the friction positive electrode of the friction nanogenerator; paste a layer of aluminum sheet (20mm*20mm*0.35mm) on the BC-CS film (20mm*20mm*0.10mm) prepared in step (2), lead it out with a copper wire (length 500mm, diameter 0.10mm), and fix it on another acrylic substrate (20mm*20mm*2.0mm) as the friction negative electrode of the friction nanogenerator. Finally, the triboelectric positive electrode and the triboelectric negative electrode are pasted together to complete the assembly of the L-CNF / BC-CS-based triboelectric nanogenerator. The electrical output performance of the triboelectric nanogenerator, such as the open circuit voltage and short circuit current, is operated according to the references: "Naturallignocellulosic nanofibrils as tribonegative materials for self-poweredwireless electronics" (https: / / doi.org / 10.1016 / j.nanoen.2022.107337) and "Cellulose II Aerogel-Based Triboelectric Nanogenerator" (DOI:10.1002 / adfm.202001763).

[0085] (4) Assembly and performance study of the composite self-powered capacitive pressure sensor: The copper sheet, cellulose-based conductive paper (flexible conductive paper prepared according to Example 1 of Chinese Patent ZL 2021 1 0323518.9), copper sheet, and acrylic substrate are sequentially bonded and attached to the bottom of the L-CNF / BC-CS-based friction nanogenerator to obtain a composite self-powered capacitive pressure sensor (the specific structure of the composite self-powered capacitive pressure sensor is shown in FIG. Figure 1As shown). The sensitivity detection of this pressure sensor was carried out according to the reference document "Siloxene / PVDF Composite Nanofibrous Membrane for High-Performance Triboelectric Nanogenerator and Self-Powered Static and Dynamic Pressure Sensing Applications" (DOI: 10.1002 / adfm.202202145).

[0086] Example 3

[0087] (1) Preparation of lignin nanocellulose (L-CNF) paper: Weigh a certain mass of bamboo chips (1.2 cm * 1.2 cm) and place them in a 1 wt% NaOH solution (the mass ratio of bamboo chips to NaOH solution is 1:10). Stir at 90 °C for 2 h to remove extracts. Thoroughly wash the residue with distilled water until a clear liquid is obtained. Immerse the bamboo chip residue in distilled water for 2 days, maintaining the mass fraction of the bamboo chip residue in the system at 2 wt%. Then, use a high-pressure microfluidic homogenizer (Nano Disperser NLM 100, Ilshin Autoclave, origin: South Korea) to process it 10 times at a pressure level of 10,000 psi to obtain an L-CNF dispersion. Adjust the L-CNF dispersion to a concentration of 0.7 wt% and stir for 12 h to obtain a homogeneous dispersion. Pour the L-CNF dispersion into a sintered glass funnel and use the "paper-making method" to vacuum filter it into paper (filter membrane diameter is 4 cm, pore size is 0.22 μm). Then, cover both sides of the wet paper sheet with filter paper and place it on a roll dryer at 80 °C for drying. After drying is completed, peel it off to obtain L-CNF paper (basis weight is 45 ± 2 g·m -2 ), and set aside.

[0088] (2) Preparation of bacterial cellulose grafted chitosan (BC-CS) film:

[0089] ① Wash the granular bacterial cellulose (BC) several times with distilled water, and then soak it in a 0.1 mol·L -1 boiling NaOH solution for 1 h to remove bacterial cells and residual impurities, obtaining purified BC. Then neutralize it with a 0.5% (v / v) acetic acid solution, and then wash it repeatedly with distilled water until the pH of the filtrate is neutral. Use a plant fiber nanomill (UH-60, purchased from China United Biotechnology Co., Ltd.) to first disperse the purified BC into a 0.4 wt% BC suspension.

[0090] ② Take 100 mL of BC suspension (0.4 wt%) and place it in a round-bottom flask. Add sodium periodate, an oxidant with a final concentration of 0.25 mol·L -1 and react at 50 °C in a constant-temperature water bath for 3.0 h (shielded from light). After the reaction, centrifuge and wash 5 times at a rotational speed of 8000 rpm to remove the residual oxidant. Finally, add water to prepare an oxidized BC suspension (concentration 2 wt%).

[0091] ③ Take 10.0 g of chitosan powder and place it in an acetic acid solution (2% (v / v), 500 mL). Stir at 60 °C for 1 h to obtain a chitosan solution. Immerse the oxidized BC suspension (usage amount 20 mL, concentration 2 wt%) in the chitosan solution and continuously stir at 60 °C for 2 h to successfully graft chitosan onto the oxidized BC. After oxidation, centrifuge and wash several times to obtain BC-CS. Disperse BC-CS in 100 mL of distilled water and ultrasonicate (ultrasonic power 800 W, ultrasonic frequency 20 kHz) for a period of time to form a uniform suspension. Pour the BC-CS suspension into a sintered glass funnel and vacuum filter it into a film (filter membrane diameter 4 cm, pore size 0.22 μm). Then, cover both sides of the wet paper sheet with filter paper and place it on a roll dryer at 80 °C for drying. After drying, peel it off to obtain a BC-CS film (thickness 100 ± 20 μm) for standby use.

[0092] ④ Determine and calculate the chitosan content grafted onto BC according to the method of Example 1. Among them, the content (%) of chitosan (CS) successfully grafted onto bacterial cellulose (BC) is calculated by the following formula: CS content (%) = N% / 14.007 * 166.74, where 166.74 / 14.007 is the ratio of the relative molecular mass of chitosan to the mass of nitrogen element. The calculated chitosan content grafted onto BC is 14.8%.

[0093] (3) Assembly and Performance Study of L-CNF / BC-CS-Based Triboelectric Nanogenerator (TENG): Take a piece of L-CNF paper (20 mm * 20 mm * 0.10 mm) prepared in step (1), paste a layer of aluminum sheet (20 mm * 20 mm * 0.35 mm) on it, lead it out with a copper wire (length 500 mm, diameter 0.10 mm), and then fix it on an acrylic substrate (20 mm * 20 mm * 2.0 mm) as the positive friction electrode of the triboelectric nanogenerator; Paste a layer of aluminum sheet (20 mm * 20 mm * 0.35 mm) on the BC-CS film (20 mm * 20 mm * 0.10 mm) prepared in step (2), lead it out with a copper wire (length 500 mm, diameter 0.10 mm), and fix it to another acrylic substrate (20 mm * 20 mm * 2.0 mm) as the negative friction electrode of the triboelectric nanogenerator. Finally, paste the positive friction electrode and the negative friction electrode together to complete the assembly of the L-CNF / BC-CS-based triboelectric nanogenerator. The operations of electrical output performance such as the open-circuit voltage and short-circuit current of the triboelectric nanogenerator are carried out according to the references: "Natural lignocellulosic nanofibrils as tribonegative materials for self-powered wireless electronics" (https: / / doi.org / 10.1016 / j.nanoen.2022.107337) and "Cellulose II Aerogel-Based Triboelectric Nanogenerator" (DOI: 10.1002 / adfm.202001763).

[0094] (4) Assembly and Performance Study of the Composite Self-Powered Capacitive Pressure Sensor: Attach a copper sheet, cellulose-based conductive paper (flexible conductive paper prepared according to Example 1 of Chinese Patent ZL 2021 1 0323518.9), a copper sheet, and an acrylic substrate to the bottom of the L-CNF / BC-CS-based triboelectric nanogenerator in sequence to obtain a composite self-powered capacitive pressure sensor (the specific structure of this composite self-powered capacitive pressure sensor is as Figure 1As shown. The sensitivity detection of this pressure sensor is carried out according to the reference document "Siloxene / PVDF Composite Nanofibrous Membrane for High-Performance Triboelectric Nanogenerator and Self-Powered Static and Dynamic Pressure Sensing Applications" (DOI: 10.1002 / adfm.202202145).

[0095] Comparative Example 1

[0096] (1) Preparation of nanocellulose (CNF) paper:

[0097] ① Weigh a certain mass of bamboo chips (1.2 cm * 1.2 cm) and place them in a 1 wt% NaOH solution (the mass ratio of bamboo chips to NaOH solution is 1:10), stir at 90 °C for 2 h to remove extracts. Thoroughly wash the residue with distilled water until a clear liquid is obtained.

[0098] ② Place 100 g of alkali-extracted bamboo chips in 3200 mL of distilled water, then add 10 mL of glacial acetic acid and 30 g of sodium chlorite. Subsequently, place it in a constant temperature water bath at 80 °C and react for 4 h, adding 30 g of sodium chlorite every 1 h during the reaction. After the reaction is completed, wash the obtained bamboo pulp with excessive distilled water until the filtrate is neutral. Immerse the bamboo chip residue in distilled water for 2 days, maintaining the mass fraction of the bamboo chip residue in the system at 2 wt%, and then use a high-pressure microfluidic homogenizer (NanoDisperser NLM 100, Ilshin Autoclave, origin: South Korea) to process it 10 times at a pressure level of 10000 psi to obtain a CNF dispersion. Adjust the CNF dispersion to a concentration of 0.7 wt% and stir for 12 h to obtain a uniform dispersion. Pour the CNF dispersion into a sintered glass funnel and use the "paper-making method" to vacuum filter it into paper (filter membrane diameter is 4 cm, pore size is 0.22 μm), then cover both sides of the wet paper sheet with filter paper and place it on a roll dryer at 80 °C for drying. After drying is completed, peel it off to obtain L-CNF paper (basis weight is 45 ± 2 g·m -2 ), for standby.

[0099] (2) Preparation of bacterial cellulose grafted chitosan (BC-CS) film:

[0100] ① Wash granular bacterial cellulose (BC) several times with distilled water, and then soak it in 0.1 mol·L -1The purified BC was obtained by boiling in NaOH solution for 1 h to remove bacterial cells and residual impurities. It was then neutralized with 0.5% (v / v) acetic acid solution and repeatedly washed with distilled water until the pH of the filtrate was neutral. The purified BC was first dispersed into a 0.4 wt% BC suspension using a plant fiber nanomill (UH-60, purchased from China United Biotechnology Co., Ltd).

[0101] ② Take 100 mL of the BC suspension (0.4 wt%) and place it in a round-bottom flask. Add sodium periodate, an oxidant with a final concentration of 0.25 mol·L -1 React for 3.0 h (shielded from light) in a constant temperature water bath at 50 °C. After the reaction, centrifuge and wash 5 times at a speed of 8000 rpm to remove the residual oxidant. Finally, add water to prepare an oxidized BC suspension (concentration: 2 wt%).

[0102] ③ Take 10.0 g of chitosan powder and place it in acetic acid solution (2% (v / v), 500 mL). Stir at 60 °C for 1 h to obtain a chitosan solution. Immerse the oxidized BC suspension (usage: 20 mL, concentration: 2 wt%) in the chitosan solution and continuously stir at 60 °C for 2 h to successfully graft chitosan onto the oxidized BC. After oxidation, centrifuge and wash several times to obtain BC-CS. Disperse BC-CS in 100 mL of distilled water and ultrasonicate (ultrasonic power: 800 W, ultrasonic frequency: 20 kHz) for a period of time to form a uniform suspension. Pour the BC-CS suspension into a sintered glass funnel and vacuum filter it into a film (filter membrane diameter: 4 cm, pore size: 0.22 μm). Then, cover both sides of the wet paper with filter paper and place it on a roll dryer at 80 °C for drying. After drying, peel it off to obtain a BC-CS film (thickness: 100 ± 20 μm) for standby.

[0103] ④ Determine and calculate the chitosan content grafted onto BC according to the method of Example 1. Among them, the chitosan (CS) content (%) grafted onto bacterial cellulose (BC) is calculated by the following formula: CS content (%) = N% / 14.007 * 166.74, where 166.74 / 14.007 is the ratio of the relative molecular mass of chitosan to the mass of nitrogen element. The calculated chitosan content grafted onto BC is 14.8%.

[0104] (3) Assembly and Performance Study of CNF / BC-CS-Based Triboelectric Nanogenerator (TENG): Take a piece of CNF paper (20mm * 20mm * 0.10mm) prepared in step (1), paste a layer of aluminum sheet (20mm * 20mm * 0.35mm) on it, lead it out with a copper wire (length 500mm, diameter 0.10mm), and then fix it on an acrylic substrate (20mm * 20mm * 2.0mm) as the positive friction electrode of the triboelectric nanogenerator; paste a layer of aluminum sheet (20mm * 20mm * 0.35mm) on the BC-CS film (20mm * 20mm * 0.10mm) prepared in step (2), lead it out with a copper wire (length 500mm, diameter 0.10mm), and fix it to another acrylic substrate (20mm * 20mm * 2.0mm) as the negative friction electrode of the triboelectric nanogenerator. Finally, paste the positive friction electrode and the negative friction electrode together to complete the assembly of the CNF / BC-CS-based triboelectric nanogenerator. The operations of electrical output performance such as the open-circuit voltage and short-circuit current of the triboelectric nanogenerator are carried out according to the references: "Natural lignocellulosic nanofibrils as tribonegative materials for self-powered wireless electronics" (https: / / doi.org / 10.1016 / j.nanoen.2022.107337) and "Cellulose II Aerogel-Based Triboelectric Nanogenerator" (DOI: 10.1002 / adfm.202001763).

[0105] (4) Assembly and Performance Study of Composite Self-Powered Capacitive Pressure Sensor: Attach a copper sheet, cellulose-based conductive paper (flexible conductive paper prepared according to Example 1 of Chinese Patent ZL 2021 1 0323518.9), a copper sheet, and an acrylic substrate to the bottom of the CNF / BC-CS-based triboelectric nanogenerator in sequence to obtain a composite self-powered capacitive pressure sensor (the specific structure of this composite self-powered capacitive pressure sensor is as Figure 1As shown). The sensitivity detection of this pressure sensor is carried out according to the reference document "Siloxene / PVDF Composite Nanofibrous Membrane for High-Performance Triboelectric Nanogenerator and Self-Powered Static and Dynamic Pressure Sensing Applications" (DOI: 10.1002 / adfm.202202145).

[0106] Comparative Example 2

[0107] (1) Preparation of lignin nanocellulose (L-CNF) paper: Weigh a certain mass of bamboo chips (1.2 cm * 1.2 cm) and place them in a 1 wt% NaOH solution (the mass ratio of bamboo chips to NaOH solution is 1:10). Stir at 90 °C for 2 h to remove the extractives. Thoroughly wash the residue with distilled water until a clear liquid is obtained. Immerse the bamboo chip residue in distilled water for 2 days, maintaining the mass fraction of the bamboo chip residue in the system at 2 wt%. Then, use a high-pressure microfluidic homogenizer (Nano Disperser NLM 100, Ilshin Autoclave, origin: South Korea) to process it 10 times at a pressure level of 10,000 psi to obtain an L-CNF dispersion. Adjust the L-CNF dispersion to a concentration of 0.7 wt% and stir for 12 h to obtain a homogeneous dispersion. Pour the L-CNF dispersion into a sintered glass funnel and use the "paper-making method" to vacuum filter it into paper (filter membrane diameter is 4 cm, pore size is 0.22 μm). Then, cover both sides of the wet paper sheet with filter paper and place it on a roll dryer at 80 °C for drying. After drying is completed, peel it off to obtain L-CNF paper (basis weight is 45 ± 2 g·m -2 ), and set aside for later use.

[0108] (2) Preparation of bacterial cellulose (BC) film: Wash granular bacterial cellulose (BC) several times with distilled water, and then soak it in 0.1 mol·L -1 boiling NaOH solution for 1 h to remove bacterial cells and residual impurities, obtaining purified BC. Pour the BC suspension into a sintered glass funnel and vacuum filter it into a film (filter membrane diameter is 4 cm, pore size is 0.22 μm). Then, cover both sides of the wet paper sheet with filter paper and place it on a roll dryer at 80 °C for drying. After drying is completed, peel it off to obtain the BC film, and set aside for later use.

[0109] (3)Assembly and performance study of L-CNF / BC-based triboelectric nanogenerator (TENG): Take a piece of L-CNF paper (20mm * 20mm * 0.10mm) prepared in step (1), paste a layer of aluminum sheet (20mm * 20mm * 0.35mm) on it, lead it out with a copper wire (length 500mm, diameter 0.10mm), and then fix it on an acrylic substrate (20mm * 20mm * 2.0mm) as the positive friction electrode of the triboelectric nanogenerator; Paste a layer of aluminum sheet (20mm * 20mm * 0.35mm) on the BC film (20mm * 20mm * 0.10mm) prepared in step (2), lead it out with a copper wire (length 500mm, diameter 0.10mm), and fix it to another acrylic substrate (20mm * 20mm * 2.0mm) as the negative friction electrode of the triboelectric nanogenerator. Finally, paste the positive friction electrode and the negative friction electrode together to complete the assembly of the L-CNF / BC-based triboelectric nanogenerator. The operations of electrical output performance such as the open-circuit voltage and short-circuit current of the triboelectric nanogenerator are carried out according to the references: 《Natural lignocellulosic nanofibrils as tribonegative materials for self-powered wireless electronics》(https: / / doi.org / 10.1016 / j.nanoen.2022.107337) and 《Cellulose II Aerogel-Based Triboelectric Nanogenerator》(DOI:10.1002 / adfm.202001763).

[0110] (4)Assembly and performance study of the composite self-powered capacitive pressure sensor: Sequentially bond a copper sheet, cellulose-based conductive paper (flexible conductive paper prepared according to Example 1 of Chinese Patent ZL 2021 1 0323518.9), a copper sheet, and an acrylic substrate to the bottom of the L-CNF / BC-based triboelectric nanogenerator to obtain a composite self-powered capacitive pressure sensor. The sensitivity detection of this pressure sensor is carried out according to the reference 《Siloxene / PVDF Composite Nanofibrous Membrane for High-Performance Triboelectric Nanogenerator and Self-Powered Static and Dynamic Pressure Sensing Applications》(DOI:10.1002 / adfm.202202145).

[0111] Effect Examples

[0112] The performance of the triboelectric nanogenerators (TENGs) and the composite capacitive pressure sensors prepared in Examples 1 to 3 and Comparative Examples 1 to 2 was compared (repeated 3 times); among them, the electrical output performance of the TENGs includes the open-circuit voltage (V) and the short-circuit current (μA), and the sensing performance of the sensors includes the pressure sensitivity (mV·kPa -1 ); the output power density was calculated by the methods and formulas described in the reference ("Stretchable thermogalvanic hydrogel thermocell with record-high specificoutput power de nsity enabled by ion-induced crystallization"; https: / / pubs.rsc.org / en / content / articlelanding / 2022 / ee / d2ee00738j).

[0113] The results of the performance analysis and comparison are shown in Table 1.

[0114] Table 1 Performance Analysis of Triboelectric Nanogenerators and Capacitive Pressure Sensors

[0115]

[0116] The performance of the triboelectric nanogenerators prepared in Examples 1 to 3 and Comparative Examples 1 to 2 was compared:

[0117] (1) As can be seen from Examples 1 to 3 in Table 1, during the assembly of the triboelectric nanogenerator, different contents of chitosan-grafted bacterial cellulose (BC-CS) in the triboelectric negative electrode have a significant impact on the output performance of the triboelectric nanogenerator (including the open-circuit voltage, short-circuit current, and output power density) and the sensitivity of the composite capacitive pressure sensor thus formed:

[0118] 1) As can be seen from Examples 1 to 3, when the chitosan content of chitosan in the triboelectric negative electrode BC-CS increased from 10.5% to 14.8%, the open-circuit voltage increased from 110 V to 150 V, the short-circuit current increased from 8 μA to 12 μA, and the output power density increased from 176 mW·m -2 to 199 mW·m -2 , that is, due to the increase in the chitosan (CS) content in BC-CS, the electrical output performance of the triboelectric nanogenerator was greatly improved.

[0119] (2) As can be seen from Examples 1 to 3, the sensitivity of the composite self-powered capacitive pressure sensor is also affected by the material of the tribo-negative electrode. Specifically, when the chitosan content in the tribo-negative electrode BC-CS increases from 10.5% to 12.1% and 14.8% in sequence, the sensitivity of the capacitive pressure sensor decreases from 20 mV·kPa -1 to 18 mV·kPa -1 and 15 mV·kPa -1 .

[0120] (2) As can be seen from Example 3 and Comparative Example 1, when lignin-containing nanocellulose (L-CNF) is used as the tribo-positive electrode, the electrical output performance of the triboelectric nanogenerator assembled with it is better than that assembled with ordinary nanocellulose (CNF) as the tribo-positive electrode. Therefore, the sensitivity of the composite self-powered capacitive pressure sensor is also better.

[0121] (3) As can be seen from Example 3 and Comparative Example 2, when bacterial cellulose (BC) without grafted chitosan is used as the tribo-negative electrode, the electrical output performance of the triboelectric nanogenerator assembled with it is worse than that assembled with BC-CS with a chitosan grafting rate of 14.8% as the tribo-negative electrode. In addition, the sensitivity of the composite self-powered capacitive pressure sensor is also lower.

[0122] From the comparison results in Table 1, it can be seen that the triboelectric nanogenerators prepared in Examples 1 to 3 of the present invention are significantly superior to Comparative Examples 1 to 2, achieving the preparation of a self-powered capacitive pressure sensor with excellent electrical output performance and sensing sensitivity, and obtaining better technical effects.

[0123] In summary, the L-CNF / BC-CS-based triboelectric nanogenerator provided by the present invention has the characteristics of excellent electrical output performance. The developed hybrid capacitive pressure sensor has high sensitivity. The raw materials used and the preparation method endow the product with flexibility, degradability, biocompatibility, low cost, wide source, recyclability and easy recovery and treatment, etc. In addition, the electrical output performance of the triboelectric nanogenerator obtained in the present invention can be regulated according to the lignin content in L-CNF and the successfully grafted chitosan (CS) content in BC-CS, that is, the electrical output performance of the triboelectric nanogenerator prepared in the present invention is adjustable, which provides more possibilities for the multi-directional development of triboelectric nanogenerators. Finally, the triboelectric nanogenerator obtained in the present invention can be used to power energy storage electrical appliances such as lighting LED lights and connecting capacitors, and power electronic devices such as flexible pressure sensors and implantable medical devices, thus providing a new selection method for the power source problem of electronic devices, which is of great significance for the development of self-powered flexible electronics.

[0124] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. A preparation method of a degradable friction nanogenerator with high output power, characterized in that, It includes the following steps: (1) Prepare L-CNF paper Place bamboo chips in a NaOH solution, conduct alkali treatment at 90 ± 5 °C, then wash with water, soak in water, and perform high-pressure homogenization treatment to obtain an L-CNF dispersion; finally, adjust the concentration of the L-CNF dispersion to 0.5 - 0.8 wt%, and form a paper through suction filtration, and dry to obtain L-CNF paper; (2) Prepare BC-CS film ① Wash granular bacterial cellulose with water and soak it in a NaOH solution to remove bacterial cells and residual impurities, then add an acetic acid solution for neutralization and wash with water until the filtrate is neutral to obtain purified BC; then disperse the purified BC into a BC suspension with a grinder; ② Add an oxidant to the BC suspension, conduct oxidation treatment at 50 ± 5 °C under light-shielded conditions, after the oxidation treatment is completed, centrifuge and wash, and then redisperse with water to obtain an oxidized BC suspension; ③ Immerse the oxidized BC suspension in an acetic acid solution containing chitosan, conduct a reaction at 60 ± 5 °C to graft chitosan onto the oxidized BC successfully, after the reaction is completed, centrifuge and wash to obtain BC-CS; then ultrasonically disperse BC-CS in water to obtain a BC-CS suspension; finally, filter the BC-CS suspension into a film and dry to obtain a BC-CS film; (3) Assemble a triboelectric nanogenerator From top to bottom, assemble an acrylic substrate, an electrode, and the L-CNF paper prepared in step (1) into the positive triboelectric electrode of the triboelectric nanogenerator in sequence. At the same time, assemble the BC-CS film, the electrode, and the acrylic substrate prepared in step (2) into the negative triboelectric electrode of the triboelectric nanogenerator in sequence, and then paste and assemble the positive triboelectric electrode and the negative triboelectric electrode of the triboelectric nanogenerator to form a triboelectric nanogenerator.

2. The preparation method of the degradable high-output power triboelectric nanogenerator according to claim 1, characterized in that: The concentration of the NaOH solution in step (1) is 1.0 - 1.5% by mass percentage; The mass ratio of the bamboo chips to the NaOH solution in step (1) is 1:5 - 15; The concentration of the L-CNF dispersion after high-pressure homogenization treatment in step (1) is 2 - 3% by mass percentage; Adjusting the concentration of the L-CNF dispersion in step (1) means adjusting it to a concentration of 0.7 wt%; The concentration of the NaOH solution in step ① is 0.1 - 0.3 mol / L; The concentration of the acetic acid solution in step ① is 0.5 - 0.8% by volume percentage; The concentration of the BC suspension in step ① is 0.3 - 0.5% by mass percentage; The oxidant in step ② is at least one of sodium periodate, sodium ferrate, sodium hypochlorite, potassium permanganate, and hydrogen peroxide; The dosage of the oxidant in step ② is calculated according to its final concentration in the reaction system being 0.1 - 0.25 mol / L; The concentration of the oxidized BC suspension in step ② is 0.5 - 2.0% by mass percentage; The concentration of chitosan in the acetic acid solution containing chitosan described in step ③ is 0.02 - 0.03 g / mL; The concentration of the BC-CS suspension described in step ③ is 0.5 - 2.0% by mass percentage.

3. The preparation method of the degradable high-output power triboelectric nanogenerator according to claim 2, characterized in that: The concentration of the NaOH solution described in step (1) is 1.0% by mass percentage; The mass ratio of the bamboo slices to the NaOH solution described in step (1) is 1:10; The concentration of the L-CNF dispersion after high-pressure homogenization treatment described in step (1) is 2% by mass percentage; The concentration of the NaOH solution described in step ① is 0.1 mol / L; The concentration of the acetic acid solution described in step ① is 0.5% by volume percentage; The concentration of the BC suspension described in step ① is 0.4% by mass percentage; The oxidant described in step ② is sodium periodate; The dosage of the oxidant described in step ② is calculated according to the final concentration of 0.25 mol / L in the reaction system; The concentration of the oxidized BC suspension described in step ② is 2.0% by mass percentage; The concentration of chitosan in the acetic acid solution containing chitosan described in step ③ is 0.02 g / mL; The concentration of the BC-CS suspension described in step ③ is 2.0% by mass percentage.

4. The preparation method of the degradable high-output power triboelectric nanogenerator according to claim 1, characterized in that: The high-pressure homogenization treatment conditions described in step (1) are: the pressure level is 10000 psi, and the number of treatment times is 8 - 10 times; The vacuum filtration described in steps (1) and ③ is carried out using a sintered glass funnel; The diameter of the filter membrane used for the vacuum filtration described in steps (1) and ③ is 4 cm, and the pore size is 0.22 µm; The drying method described in steps (1) and ③ is drying with a drying cylinder, and the drying temperature is 80 ± 5°C; The acetic acid solution containing chitosan described in step ③ is obtained by the following method: adding chitosan powder to the acetic acid solution and stirring and dissolving it at 60 ± 5°C to obtain the acetic acid solution containing chitosan; The concentration of the acetic acid solution is 0.2 - 0.3% by volume percentage; The chitosan is chitosan with a viscosity of 200 - 400 mPa·s.

5. The preparation method of the degradable high-output power triboelectric nanogenerator according to claim 1, characterized in that: The time of the alkali treatment described in step (1) is 1 - 3 h; The time of the soaking described in step (1) is 1 - 3 days; The time of the soaking described in step ① is 1 - 3 h; The time of the oxidation treatment described in step ② is 2.5 - 3.0 h; The conditions for the centrifugal washing described in step ② are: centrifugal washing is carried out at a rotation speed of 8000 rpm; The time of the reaction described in step ③ is 2 - 3 h; The power of the ultrasonic wave described in step ③ is 800 W, and the frequency is 20 kHz; The electrodes described in step (3) are all aluminum sheets.

6. A degradable triboelectric nanogenerator with high output power, characterized in that: Prepared by the method according to any one of claims 1 - 5.

7. Use of the friction nanogenerator with degradability and high output power according to claim 6 in the preparation of electronic devices.

8. The use according to claim 7, characterized in that: The electronic device is an LED lamp, a energy storage electrical appliance, a flexible pressure sensor, an implantable medical device, a bionic robot or a medical real-time monitoring device; The flexible pressure sensor includes a flexible wearable sensor; The medical real-time monitoring device includes a medical real-time monitoring device for detecting human limb movement, pulse and / or heart rate.

9. A self-powered pressure sensor with degradability and high output power, characterized in that: It includes the friction nanogenerator according to claim 6, a first electrode, a flexible pressure sensing layer, a second electrode and an acrylic substrate arranged from top to bottom; The flexible pressure sensing layer is a cellulose-based conductive paper.

10. The self-powered pressure sensor with degradability and high output power according to claim 9, characterized in that: Both the first electrode and the second electrode are copper sheets.

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