A high-toughness stretchable positive electrode material with TPU / ANF / inorganic nanoparticle composite and a preparation method thereof

Abstract

The application relates to the technical field of high-molecular fiber sensing, in particular to a high-toughness TPU / ANF / inorganic nanoparticle composite nanometer friction positive electrode material and a preparation method thereof. The preparation method takes TPU as a base main material, does not depend on a chemical cross-linking method, and realizes flexible adaptation of a complex deformation scene by virtue of excellent stretchable deformation performance and flexible characteristics of the TPU. Meanwhile, aramid nanofiber (ANF) is introduced as a reinforcing phase, the high-strength and high-modulus characteristics of the aramid nanofiber are utilized to improve the stress and strain capacity and mechanical stability of the base, the aramid nanofiber can lock the molecular structure in the TPU, and the aramid nanofiber can inhibit significant shrinkage of the material when the temperature is increased, so that the aramid nanofiber has the dual functions of mechanical enhancement and size stability, and the reliability of a generator is ensured.

Description

Technical Field

[0001] This invention relates to the field of polymer fiber sensing technology, specifically to a high-toughness stretchable cathode material composed of high-toughness TPU / ANF / inorganic nanoparticles and its preparation method. Background Technology

[0002] Among numerous cutting-edge technologies, triboelectric nanogenerators stand out due to their unique advantages, becoming a highly promising green energy solution. This technology can not only efficiently collect mechanical energy (such as vibration, water flow, and human movement) widely present in the environment and convert it into electrical energy, turning waste into treasure, but also has outstanding features such as simple structure, low manufacturing cost, environmentally friendly materials, high energy conversion efficiency, and wide applicability. It does not rely on fossil fuels and can reduce carbon emissions and environmental pollution, perfectly matching the concept of green development. It provides an innovative path to solve the dual problems of energy shortage and ecological protection, and its application prospects and research value have attracted much attention.

[0003] One of the core challenges in the practical application of triboelectric nanogenerators is to efficiently capture dispersed energy from minute movements such as human motion and environmental vibrations. This requires the substrate material to possess excellent deformation capabilities, enabling it to stably withstand repeated stretching, bending, and other mechanical forces without failure. Existing triboelectric nanogenerator materials are mostly polymer-based, which have poor deformation capabilities, making it difficult to adapt to changes in human movement and displacement, and also unable to accurately identify minute energy changes. Summary of the Invention

[0004] To address the problems in the prior art, this invention provides a high-toughness stretchable cathode material composed of high-toughness TPU / ANF / inorganic nanoparticles and its preparation method, which can be used as a wearable sensing material in high-temperature environments and self-powered wearable fields.

[0005] This invention is achieved through the following technical solution: A method for preparing a high-toughness, stretchable cathode material composed of TPU / ANF / inorganic nanoparticles includes: S1, Preparation of TPU solution: TPU particles are dissolved to form a TPU solution, and the solvent is one of N,N-dimethylacetamide (DMAc), dimethyl sulfoxide (DMSO), N-methylpyrrolidone (NMP), and N,N-dimethylformamide (DMF); Preparation of ANF solution: Dissolve potassium hydroxide and para-aramid chopped fibers in DMSO; S2, mix TPU solution and ANF solution to obtain precursor mixture; S3, Inorganic nanoparticles are added to the precursor mixture to obtain a mixed solution; S4. The mixed solution is formed into a composite wet film by thin film forming, then phase-transformed with water, and then dried to obtain the positive electrode material.

[0006] Preferably, in S1, the concentration of the TPU solution is 10 wt% to 30 wt%.

[0007] Preferably, in S1, the mass of potassium hydroxide added is 1 to 2 times that of aramid chopped fibers, and the concentration of the ANF solution is 0.5 wt% to 2 wt%.

[0008] Preferably, in S2, the stirring time is 5~15h.

[0009] Preferably, in S3, the inorganic nanoparticles are one of hydroxyapatite nanoparticles (HAP), silica nanoparticles (SiO2), zinc oxide particles (ZnO), aluminum oxide (Al2O3), and titanium dioxide (TiO2).

[0010] Preferably, in S3, the amount of inorganic nanoparticles added is 5% to 20% of the mass of aramid nanofibers.

[0011] Preferably, in S4, the film forming method is one of electrospinning, spraying, scraping, or template method.

[0012] Preferably, in S4, the drying temperature is 50℃~80℃ and the time is 6h~15h.

[0013] A cathode material obtained according to the method for preparing a high-toughness stretchable cathode material composed of high-toughness TPU / ANF / inorganic nanoparticles.

[0014] A triboelectric nanogenerator, wherein the positive electrode is made of the aforementioned positive electrode material.

[0015] Compared with the prior art, the present invention has the following beneficial effects: This invention discloses a method for preparing a high-toughness, stretchable cathode material composed of TPU / ANF / inorganic nanoparticles. Using TPU as the base material, it abandons the chemical cross-linking methods relied upon in traditional cathode materials. Leveraging the excellent stretchability and flexibility of TPU, it can flexibly adapt to complex dynamic deformation scenarios such as human joint movements and limb bending, thus solving the problems of poor deformation capacity and easy breakage of traditional cross-linked materials. Simultaneously, the TPU material can quickly rebound after repeated bending and significant stretching, forming a stable structure with both high toughness and self-healing ability, far exceeding the deformation tolerance of traditional materials. This meets the stringent requirements of generators for deformation effects and shape adaptability, which is one of the core advantages of this invention compared to existing methods that rely on chemical cross-linking to achieve improved toughness. Unlike existing designs with a single reinforcing phase, this invention innovatively introduces aramid nanofibers (ANF) as a reinforcing phase. Utilizing their high strength and high modulus properties, ANF significantly enhances the stress-strain capacity and mechanical stability of the substrate material, solving the problems of insufficient mechanical strength and easy wear of traditional TPU substrates. More importantly, ANF can lock the internal molecular structure of TPU, effectively suppressing significant shrinkage of the material at elevated temperatures, achieving the dual functions of mechanical reinforcement and dimensional stability. This avoids structural failure or performance degradation caused by temperature changes and repeated deformation in traditional materials, thus ensuring the reliability of the generator under complex operating conditions.

[0016] This invention overcomes the limitations of existing single or two-component composites by achieving functional integration and performance leap through the synergistic effect of TPU, ANF, and inorganic nanoparticles: TPU provides an excellent deformation basis, ANF enhances mechanical and dimensional stability, and inorganic nanoparticles significantly increase the material's charge density through interfacial effects and charge storage characteristics. The synergistic effect of these three components not only meets the core requirements of generators for mechanical properties (stretchability, high toughness, and wear resistance) but also significantly improves energy conversion efficiency, thus achieving a dual breakthrough in mechanical stability and energy capture efficiency. This distinguishes it from existing materials that only focus on optimizing a single performance aspect and cannot simultaneously address both.

[0017] For wearable sensing applications, the cathode material obtained in this invention precisely matches five core performance requirements, distinguishing it from traditional materials with poor adaptability and limited application scenarios: First, it exhibits excellent flexibility and deformation adaptability, perfectly matching dynamic deformations such as joint movement and muscle contraction, possessing good mechanical durability and avoiding structural damage or performance degradation caused by deformation during wear; Second, it boasts high sensitivity and rapid response, accurately capturing subtle human movements (such as breathing fluctuations) and weak physiological signals (such as pulse), with a response time reaching millisecond levels, ensuring real-time and accurate data acquisition; Third, it exhibits strong environmental adaptability, maintaining stable power generation efficiency and sensing accuracy even in complex environments such as sweat corrosion, temperature and humidity changes, and repeated friction, unaffected by significant environmental factors; Fourth, it is lightweight and thin, meeting the needs of wearable devices without increasing the burden of wearing them; Fifth, it has high biocompatibility, being bio-friendly, non-toxic, non-irritating, and breathable, suitable for long-term skin contact, thus solving the pain points of poor biocompatibility and discomfort associated with traditional wearable cathode materials.

[0018] Based on the efficient energy collection and conversion capabilities of the cathode material of this invention, wearable devices can be self-powered via TENG, eliminating the need for frequent battery replacements and significantly improving their battery life and ease of use. This overcomes the limitations of traditional wearable devices that rely on external batteries, have short battery life, and are inconvenient to use. Simultaneously, leveraging its highly sensitive sensing characteristics for subtle human movements and physiological signals, it can accurately capture human movement status and physiological health data, providing reliable data support for scenarios such as motion monitoring, health warnings, and medical rehabilitation assessments. This expands the application boundaries of wearable devices and overcomes the technical bottleneck of traditional materials being unable to simultaneously achieve power generation and precise sensing. Attached Figure Description

[0019] Figure 1 This is a flowchart of a method for preparing a high-toughness, stretchable cathode material composed of high-toughness TPU / ANF / inorganic nanoparticles according to the present invention. Figure 2 This is a schematic diagram of the process for preparing the cathode material using the template method in Example 3; Figure 3 A photograph of the cathode material prepared in Example 1; Figure 4 This is the contact friction voltage response of Example 4. Detailed Implementation

[0020] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0021] Exemplary embodiments of the present invention will now be described with reference to the accompanying drawings. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein. These embodiments are provided to fully and completely disclose the invention and to fully convey its scope to those skilled in the art. The terminology used in the exemplary embodiments illustrated in the drawings is not intended to limit the invention. In the drawings, the same units / elements are referred to by the same reference numerals.

[0022] Unless otherwise stated, the terms used herein (including technical terms) have their common meaning as understood by one of ordinary skill in the art. Furthermore, it is understood that terms defined in commonly used dictionaries should be understood to have a meaning consistent with the context of their relevant field, and not to be interpreted as having an idealized or overly formal meaning.

[0023] The present invention will be further described in detail below with reference to specific embodiments. These descriptions are for explanation purposes only and are not intended to limit the scope of the invention.

[0024] This invention discloses a method for preparing a high-toughness, stretchable cathode material composed of high-toughness TPU / ANF / inorganic nanoparticles, referring to... Figure 1 ,include: S1, Preparation of TPU solution: Dissolve TPU particles to form a 10 wt%~30 wt% TPU solution, the solvent being one of N,N-dimethylacetamide (DMAc), dimethyl sulfoxide (DMSO), N-methylpyrrolidone (NMP), and N,N-dimethylformamide (DMF).

[0025] Preparation of ANF solution: Dissolve potassium hydroxide and para-aramid chopped fibers in DMSO, wherein the mass of potassium hydroxide added is 1 to 2 times that of para-aramid chopped fibers, and the concentration of ANF solution is 0.5 wt% to 2 wt%.

[0026] S2, mix TPU solution and ANF solution, stir for 5~15h to obtain precursor mixture. S3. Inorganic nanoparticles are added to the precursor mixture to obtain a mixed solution. The inorganic nanoparticles are one of the following: hydroxyapatite nanoparticles (HAP), silica nanoparticles (SiO2), zinc oxide particles (ZnO), aluminum oxide (Al2O3), or titanium dioxide (TiO2). The amount of inorganic nanoparticles added is 5% to 20% of the mass of the aramid nanofibers.

[0027] S4. The mixed solution is formed into a composite wet film by thin film forming, then phase-inverted with water, and then dried at 50℃~80℃ for 6h~15h to obtain the positive electrode material.

[0028] The film forming method is one of the following: electrospinning, spraying, scraping, or stencil forming.

[0029] The present invention also discloses a cathode material obtained by the preparation method of the high-toughness TPU / ANF / inorganic nanoparticle composite high-toughness stretchable cathode material, which has the characteristics of high toughness and stretchability.

[0030] The present invention also discloses a triboelectric nanogenerator, the positive electrode of which is made of the aforementioned positive electrode material.

[0031] Example 1 S1, Preparation of TPU solution and ANF solution: TPU particles were incorporated into N,N-dimethylacetamide (DMAc) at a concentration of 10 wt%. The ANF solution was prepared by alkaline deprotonation method. Para-aramid chopped fibers were dissolved in DMSO at a concentration of 0.5 wt%, and KOH was added at a mass equal to that of the aramid chopped fibers.

[0032] S2, after mixing the two solutions, stir for 5 hours to obtain the precursor mixture.

[0033] S3, Preparation of TPU / ANF / inorganic nanoparticle mixed solution: Select inorganic nanoparticles hydroxyapatite nanoparticles (HAP), add 5% of the mass of aramid nanofibers, and put them into the precursor mixture to obtain a mixed solution.

[0034] S4, Preparation of composite membrane: The mixed solution is electrospinned to form a composite wet membrane. After phase inversion with water, the composite wet membrane is dried in a blower dryer at 50°C for 6 hours to obtain the positive electrode material.

[0035] S5, Assemble the triboelectric nanogenerator: Use a cutter to cut the positive electrode material and the selected negative electrode material from step (3) into 5×5 cm pieces. 2 A square of the same size has copper tape pasted onto the back of the positive and negative electrode friction material films, respectively. Wires are connected to the upper and lower electrodes to form a triboelectric nanogenerator.

[0036] Example 2 S1, Preparation of TPU solution and ANF solution: TPU particles were incorporated into N,N-dimethylformamide (DMF) at a concentration of 30 wt%. The ANF solution was prepared by alkaline deprotonation method. Para-aramid chopped fibers were dissolved in DMSO at a concentration of 2 wt%, and the mass of KOH added was twice that of the aramid chopped fibers.

[0037] S2, after mixing the two solutions, stir for 15 hours to obtain the precursor mixture.

[0038] S3, Preparation of TPU / ANF / inorganic nanoparticle mixed solution: Select titanium dioxide (TiO2), add it at 20% of the mass of aramid nanofiber, and put it into the precursor mixture to obtain a mixed solution.

[0039] S4, Preparation of composite membrane: The mixed solution is coated to form a film to obtain a composite wet membrane; the composite wet membrane is then subjected to phase inversion with water and dried in a blower dryer at 80°C for 15 hours to obtain the positive electrode material.

[0040] S5, Assemble the triboelectric nanogenerator: Use a cutting machine to cut the positive electrode material and the selected negative electrode material into 5×5cm pieces. 2 A square of the same size has copper tape pasted onto the back of the positive and negative electrode friction material films, respectively. Wires are connected to the upper and lower electrodes to form a triboelectric nanogenerator.

[0041] Example 3 S1, Preparation of TPU solution and ANF solution: TPU particles are incorporated into dimethyl sulfoxide (DMSO) at a concentration of 20 wt%. The ANF solution is prepared by alkaline deprotonation method, in which para-aramid chopped fibers are dissolved in DMSO at a concentration of 1.5 wt%, and the mass of KOH added is 1.5 times that of the aramid chopped fibers.

[0042] S2, after mixing the two solutions, stir for 10 hours to obtain the precursor mixture.

[0043] S3, Preparation of TPU / ANF / inorganic nanoparticle mixed solution: Select inorganic nanoparticles hydroxyapatite nanoparticles (HAP), add 10% of the mass of aramid nanofibers, and put them into the precursor mixture to obtain a mixed solution.

[0044] S4, Preparation of composite membrane: The mixed solution is formed into a film using a template method to obtain a composite wet membrane; the composite wet membrane is then subjected to phase inversion with water and dried in a blower dryer at 70°C for 8 hours to obtain the positive electrode material.

[0045] S5, Assemble the triboelectric nanogenerator: Use a cutting machine to cut the positive electrode material and the selected negative electrode material into 5×5cm pieces. 2 A square of the same size has copper tape pasted onto the back of the positive and negative electrode friction material films, respectively. Wires are connected to the upper and lower electrodes to form a triboelectric nanogenerator.

[0046] Reference Figure 2 The implementation process of the template method for preparing stretchable cathode materials is as follows: First, a precursor mixture is prepared in a beaker as the raw material for subsequent molding. Then, the mixture is poured onto the surface of a template with a checkerboard pattern, spreading it evenly and filling the grooves or patterned areas of the template. The template covered with the mixture is placed in a specific device, where phase separation occurs through solvent exchange, temperature changes, or chemical reactions, forming a solid precursor with a checkerboard structure. The phase-transformed material is removed from the template and dried to finally obtain a cathode material with a clear black and white checkerboard pattern (e.g., [missing information - likely a specific material]). Figure 3 As shown, the length is 16.2cm.

[0047] The cathode material obtained in Example 3 was subjected to a tensile test. The cathode material could be stretched to twice its original length without breaking, which proves that the cathode material has excellent mechanical flexibility and durability, as well as high ductility and tensile strength, and can withstand large deformations without damage.

[0048] Example 4 S1, Preparation of TPU solution and ANF solution: TPU particles were incorporated into N-methylpyrrolidone (NMP) at a concentration of 15 wt%. The ANF solution was prepared by alkaline deprotonation method. Para-aramid chopped fibers were dissolved in DMSO at a concentration of 1.2 wt%, and KOH was added at a mass of 1.2 times that of the aramid chopped fibers.

[0049] S2, after mixing the two solutions, stir for 9 hours to obtain the precursor mixture.

[0050] S3, Preparation of TPU / ANF / inorganic nanoparticle mixed solution: Select inorganic nanoparticles zinc oxide particles (ZnO), add 10% of the mass of aramid nanofibers, and put them into the precursor mixture to obtain a mixed solution.

[0051] S4, Preparation of composite membrane: The mixed solution is treated by spraying to form a film, and a composite wet membrane is obtained; the composite wet membrane is subjected to phase inversion with water, and then placed in a blower dryer to dry at 70°C for 8 h to obtain the positive electrode material.

[0052] Figure 4 The open-circuit voltage of the positive electrode material obtained in Example 4 is 9.6V.

[0053] The above description is merely a preferred embodiment of the present invention and is not intended to limit the technical solution of the present invention in any way. Those skilled in the art should understand that, without departing from the spirit and principles of the present invention, the technical solution can be modified and replaced in several simple ways, and these modifications and replacements are all within the scope of protection covered by the claims.

Claims

1. A method for preparing a high-toughness stretchable positive electrode material with high toughness TPU / ANF / inorganic nanoparticle composite, characterized in that, include: S1, Preparation of TPU solution: TPU particles are dissolved to form a TPU solution, and the solvent is one of N,N-dimethylacetamide (DMAc), dimethyl sulfoxide (DMSO), N-methylpyrrolidone (NMP), and N,N-dimethylformamide (DMF); Preparation of ANF solution: Dissolve potassium hydroxide and para-aramid chopped fibers in DMSO; S2, mix TPU solution and ANF solution, stir to obtain precursor mixture; S3, Inorganic nanoparticles are added to the precursor mixture to obtain a mixed solution; S4. The mixed solution is formed into a composite wet film by thin film forming, then phase-transformed with water, and then dried to obtain the positive electrode material.

2. The method for preparing the high-toughness stretchable cathode material of high-toughness TPU / ANF / inorganic nanoparticle composite according to claim 1, characterized in that, In S1, the concentration of the TPU solution is 10 wt% to 30 wt%.

3. The method for preparing a high-toughness, stretchable cathode material composed of high-toughness TPU / ANF / inorganic nanoparticles according to claim 2, characterized in that, In S1, the mass of potassium hydroxide added is 1 to 2 times that of aramid chopped fibers, and the concentration of ANF solution is 0.5 wt% to 2 wt%.

4. The method for preparing the high-toughness stretchable cathode material of high-toughness TPU / ANF / inorganic nanoparticle composite according to claim 1, characterized in that, In S2, the stirring time is 5~15h.

5. The method for preparing the high-toughness, stretchable cathode material of high-toughness TPU / ANF / inorganic nanoparticle composite according to claim 1, characterized in that, In S3, the inorganic nanoparticles are one of the following: hydroxyapatite nanoparticles (HAP), silica nanoparticles (SiO2), zinc oxide particles (ZnO), aluminum oxide (Al2O3), and titanium dioxide (TiO2).

6. The method for preparing the high-toughness stretchable cathode material of high-toughness TPU / ANF / inorganic nanoparticle composite according to claim 1, characterized in that, In S3, the amount of inorganic nanoparticles added is 5% to 20% of the mass of aramid nanofibers.

7. The method for preparing the high-toughness stretchable cathode material of high-toughness TPU / ANF / inorganic nanoparticle composite according to claim 1, characterized in that, In S4, the film forming method is one of electrospinning, spraying, scraping, or stenciling.

8. The method for preparing the high-toughness stretchable cathode material of high-toughness TPU / ANF / inorganic nanoparticle composite according to claim 1, characterized in that, In S4, the drying temperature is 50℃~80℃ and the time is 6h~15h.

9. A cathode material obtained by the method for preparing a high-toughness TPU / ANF / inorganic nanoparticle composite high-toughness stretchable cathode material according to any one of claims 1 to 8.

10. A triboelectric nanogenerator, wherein the positive electrode is made of the positive electrode material as described in claim 9.

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