Nanometer optical fiber-gold nanowire battery expansion sensor and preparation process thereof

Abstract

The invention relates to a nano optical fiber-gold nanowire battery expansion sensor and a preparation process thereof. According to the sensor, the nanofibers and the gold nanowires are combined, and the surface plasma resonance (SPR) effect is utilized, so that the real-time high-sensitivity monitoring of the expansion state of the battery is realized. The core structure of the sensor comprises a nano optical fiber, a gold nanowire and a flexible material protection layer. When the battery expands, the SPR strength changes due to the deformation of the gold nanowires, so that the expansion degree of the battery can be accurately judged. The method has the advantages of being compact in structure, high in sensitivity, easy to integrate and the like, and is suitable for safety monitoring of various types of batteries.

Description

Technical Field

[0001] The invention relates to the field of optical fiber sensing measurement, and in particular to a nano optical fiber-gold nanowire battery expansion sensor and a preparation process thereof. Background Art

[0002] With the continuous development of science and technology, batteries, as an important component of various electronic devices, are increasingly concerned about their safety. During use, batteries may swell due to various reasons, such as overcharging, over-discharging, temperature changes, etc. Battery expansion will not only lead to a decline in device performance, but may also cause safety hazards, such as battery bulging, leakage, and even explosion. Therefore, real-time monitoring and accurate detection of battery swelling is particularly important.

[0003] The current sensor technology used for monitoring battery expansion, such as solutions based on capacitance changes and strain gauges, generally has the disadvantages of low sensitivity, complex structure, and high cost, especially poor performance when detecting slight battery expansion. In order to overcome the shortcomings of the prior art, the present invention proposes a battery expansion monitoring sensor based on nano-fiber and gold nanowire technology and a preparation method thereof. The method utilizes the SPR effect stimulated by gold nanowires in combination with nano-fibers, and uses SPR intensity demodulation technology to judge the battery expansion state, thereby achieving rapid and accurate monitoring of the battery expansion state, with higher sensitivity and safety. Summary of the invention

[0004] The purpose of the present invention is to combine nanofiber with SPR stimulated by gold nanowires to provide a nanofiber-gold nanowire battery expansion sensor and a preparation process. The sensor can quickly and accurately judge the battery expansion state from the demodulation device, and is more sensitive and safe.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0006] Nano-fiber-gold nanowire battery expansion sensor, whose core structure includes nano-fiber, gold nanowire and flexible material protective layer.

[0007] The gold nanowires are mixed with a flexible material solution and arranged on the side of the optical fiber by a pulling method, thereby forming a composite SPR sensitive structure, thereby enhancing the stability of the gold nanowires and the overall performance of the sensor;

[0008] In the mixed solution of the gold nanowires and the flexible material, the average spacing between the gold nanowires is 20 nm to 100 nm, and the gold nanowires are evenly distributed in the flexible material, which can more effectively stimulate the SPR effect, thereby enhancing the performance of the sensor.

[0009] The flexible protective layer not only seals the gaps between the gold nanowires, protects the integrity and stability of the gold nanowire array, but also improves the flexibility of the sensor module;

[0010] The sensor module is wrapped around the battery surface in a specific direction. Its design characteristics ensure that during detection, the sensor can effectively sense and respond to the expansion state of the battery only when polarized light in a specific direction is used as the detection light source. This specific optical configuration ensures that the sensor can accurately capture subtle deformation changes caused by battery expansion during the monitoring process, thereby improving the sensitivity and accuracy of detection.

[0011] The demodulation device of the sensor module includes a phase demodulation device for extracting phase information from the reflected light, and then analyzing the change in the contact area between the gold nanowires and PDMS to monitor the degree of battery expansion.

[0012] The present invention adopts an innovative method to tightly wrap the sensor module around the battery to be tested. Through precise light source coupling technology, it is ensured that light can effectively enter the optical fiber. When the battery expands, the sensor module deforms accordingly, and the physical state of the gold nanowire array changes significantly. Through the demodulation technology of SPR intensity, the expansion state of the battery can be monitored more accurately.

[0013] The beneficial effects of the present invention are:

[0014] The present invention successfully realizes a highly sensitive sensor system for real-time monitoring of battery expansion status by combining gold nanowire arrays with nano-fiber technology. The system uses the SPR effect stimulated by gold nanowires and uses SPR intensity demodulation technology to accurately judge the battery expansion, thereby improving the safety of the battery. The system not only has high sensitivity and stability, and can accurately detect battery expansion, but also has a compact structure, is easy to integrate, and is suitable for a variety of battery types. In addition, by introducing a flexible material protective layer, the flexibility and durability of the sensor module are enhanced, making it more advantageous in practical applications.

[0015] Through the above invention content, the present invention provides a new technical path for the field of battery expansion monitoring, which is expected to promote the development of battery safety monitoring technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0017] Figure 1This is a schematic diagram of the structure of a nano-fiber-gold nanowire battery expansion sensor according to an embodiment of the present invention;

[0018] Figure 2 This is a schematic diagram of the preparation process of gold nanowires according to an embodiment of the present invention;

[0019] Figure 3 This is a schematic diagram of the process of arranging the surface of the nano-optical fiber by mixing a solution of gold nanowires and a flexible material according to an embodiment of the present invention; Figure 4 This is a working principle diagram of a battery expansion monitoring sensor based on nano-optical fiber and gold nanowire technology according to an embodiment of the present invention. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] In one embodiment of the present invention, polydimethylsiloxane (PDMS) is selected as the flexible material because of its good flexibility and environmental adaptability. The flexibility of PDMS can ensure that the sensor can effectively deform during the battery expansion monitoring process, while its environmental adaptability can ensure that the sensor remains stable under different lithium battery environmental conditions.

[0022] The present invention aims to propose a nano-fiber-gold nanowire battery expansion sensor monitoring system, aiming to achieve real-time and accurate monitoring of the expansion state of a battery to be tested.

[0023] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0024] Figure 1 The schematic diagram of the structure of the nanofiber-gold nanowire battery expansion sensor proposed in the present invention is shown. The core part of the sensor includes nanofiber, gold nanowire and PDMS protective layer; gold nanowires are mixed with PDMS solution to form a low-density gold nanowire solution, which is laid on the side of the optical fiber using the pulling technology to form a composite structure; this low-density gold nanowire layout is designed to more effectively stimulate the SPR effect, thereby enhancing the performance of the sensor.

[0025] A nano-fiber with a diameter of 500nm was selected as the core component. The fiber has a cladding diameter of 125μm and a cladding refractive index of 1.45. The coating layer of the fiber was removed, and ultrasonic cleaning technology was used to remove impurities and contaminants to ensure the purity of the fiber surface.

[0026] Figure 2 A schematic diagram of the gold nanowire preparation and dispersion process is shown;

[0027] Furthermore, the preparation of gold nanowires comprises the following steps:

[0028] A1. Soak the silicon wafer in 5% hydrofluoric acid solution for 2-4 hours to remove surface impurities and oxide layer. Then, ultrasonically clean the soaked silicon wafer with acetone, ethanol and deionized water for 15 minutes in sequence. Then, dry it with 99.99% high-purity nitrogen to ensure that the surface of the silicon wafer is clean and dry.

[0029] A2. Perform three magnetron sputterings to deposit chromium, gold, and aluminum layers in sequence. The first magnetron sputtering deposits a 10nm thick chromium layer as a bottom layer to enhance adhesion and conductivity; the second magnetron sputtering deposits a 10nm thick gold layer as the main material for gold nanowires; the third magnetron sputtering deposits a 200nm thick aluminum layer as an anodized barrier layer to prevent aluminum oxide from directly contacting the gold layer;

[0030] A3. Anodic oxidation to form porous alumina. The silicon wafer after magnetron sputtering is used as the anode and the platinum electrode is used as the cathode. Constant voltage anodic oxidation is performed in 0-1°C, 0.3M oxalic acid solution. The oxidation voltage is controlled to 40V until there is violent gas precipitation in the electrolyte and the temperature rises rapidly. At this time, the voltage is quickly removed to stop oxidation, and a porous alumina layer with uniform pore size distribution is formed on the silicon wafer, with a pore size of 40nm;

[0031] A4. Prepare gold nanowires by electrodeposition, using an oxidized silicon wafer as a working electrode, a platinum sheet electrode as a counter electrode, and a saturated potassium chloride electrode as a reference electrode, and performing three-electrode direct current electrodeposition in a mixed solution of 0.05 mol / L tetrachloroauric acid, 0.42 mol / L sodium sulfite, and 0.42 mol / L sodium thiosulfate, wherein the volume ratio of tetrachloroauric acid, sodium sulfite, and sodium thiosulfate in the electroplating solution is controlled to be (1-1.5):(1-2):(1-2), and the electrodeposition voltage and current are controlled until gold overflows from the alumina pores, the conductive area increases, and the current increases, at which time the electrodeposition is stopped to form a gold nanowire array on the silicon wafer;

[0032] A5, remove the porous alumina and collect the gold nanowires, place the electrodeposited silicon wafer in a 0.3M sodium hydroxide solution for etching to remove the porous alumina layer; wash the silicon wafer after the alumina is removed with ethanol, and dry it with high-purity nitrogen; use 7-8wt% polyvinyl alcohol (PVA) to coat the gold nanowires, and after the PVA solidifies, tear the PVA and the gold nanowires off the silicon wafer together; place the torn PVA and gold nanowires in water to dissolve the PVA, and finally obtain a gold nanowire array;

[0033] A6. The gold nanowire array was evenly dispersed in a 95% ethanol solution, and polyvinyl pyrrolidone (PVP) was introduced as a surfactant to improve the dispersibility of the gold nanowires. Subsequently, an ultrasonic generator was used for ultrasonic treatment to further ensure the uniform distribution of the nanowires. The gold nanowire lumps that were not effectively dispersed were removed by centrifugation, and the solution was centrifuged at a speed of 5000 rpm for 10 minutes to finally obtain a stably dispersed gold nanowire solution.

[0034] Figure 3 The schematic diagram of the process of arranging a mixed solution of gold nanowires and PDMS on the surface of nanofiber by pulling is shown. The specific operation steps are as follows:

[0035] B1. Fully mix the pre-dispersed gold nanowire solution with the 5% PDMS solution, and stir them thoroughly with a stirring rod until the two liquids are completely fused to form a uniform mixed solution;

[0036] B2. Accurately add the prepared mixed solution drop by drop onto the cladding surface of the nanofiber, and gently lift the nanofiber vertically from the solution slowly by pulling, ensuring that the solution forms a uniform and continuous coating layer on the surface of the fiber;

[0037] B3. Place the pulled optical fiber in an oven and dry it at 60°C for 1 hour to promote the solidification of the mixed solution. After the solidification is completed, the desired sensor structure is finally obtained.

[0038] Figure 4 The working principle diagram of the battery expansion monitoring sensor based on nano-fiber and gold nanowire technology of the embodiment of the present invention. The working principle of the sensor is as follows: a beam of light is introduced into the nano-fiber. When the light encounters the gold nanowire on the surface of the fiber, due to the SPR effect, the propagation path of the light changes, resulting in a change in the intensity of the reflected light. This change can be detected by the SPR demodulation device, thereby reflecting the degree of expansion of the battery. In different expansion stages, the deformation of the gold nanowire will also be different, which will affect the degree of the SPR effect, thereby affecting the intensity of the reflected light. And an integrated microcontroller unit (MCU) is used to realize automatic data collection and processing. By analyzing these data, the expansion state of the battery can be understood.

[0039] The demodulation device includes a phase demodulation device for extracting phase information from the reflected light, and then analyzing the change in the contact area between the gold nanowire and the PDMS to monitor the degree of battery expansion.

[0040] After the sensor body is formed, its gold nanowire structure can effectively monitor the expansion of the battery. When the battery expands, the gold nanowire is subjected to pressure, causing it to deform. This deformation causes changes in the internal structure of the gold nanowire, which in turn affects its contact area and conductivity with PDMS. Due to changes in the internal structure of the gold nanowire, the resistance changes, and different degrees of deformation will cause different amplitudes of resistance change, which ultimately affects the SPR intensity. Specifically, when the gold nanowire is subjected to pressure, changes in its internal structure will cause changes in the SPR effect, thereby causing the intensity of the reflected light to change. This change can be used to demodulate the degree of battery expansion by detecting changes in the SPR intensity.

[0041] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any technician familiar with the profession, without departing from the scope of the technical solution of the present invention, according to the technical essence of the present invention, any simple modification, equivalent replacement and improvement made to the above embodiment still falls within the protection scope of the technical solution of the present invention.

Claims

1. A nano-fiber-gold nanowire battery expansion sensor and its preparation process, characterized in that: The sensor includes nano-optical fibers, gold nanowires and a flexible material protective layer, and achieves real-time monitoring of the battery expansion state through the surface plasmon resonance (SPR) effect.

2. The battery expansion monitoring sensor according to claim 1, wherein: The gold nanowires are mixed with flexible materials to form a composite structure, which is arranged on the side of the nano-optical fiber in a pulling manner to improve the excitation efficiency of the SPR effect.

3. The sensor device according to claim 2, characterized in that The coupling effect between the gold nanowires and the nanofibers causes the interaction between the gold nanowires and the nanofibers to reduce the distance between the gold nanowires when the battery expands, thereby affecting the excitation intensity of the SPR effect, thereby affecting the intensity of the reflected light, so that the sensor has adjustable sensitivity.

4. The battery expansion monitoring sensor according to claim 3, wherein: The average spacing between the gold nanowires is 20nm to 100nm, and the effective spacing is adjusted by pressure to change the resonance mode, thereby achieving accurate monitoring of battery expansion.

5. The battery expansion monitoring sensor according to claim 3, wherein: The sensor module uses high-precision optical fiber coupling technology to adjust the density of gold nanowires and the length coated on the nano-optical fiber to meet the monitoring needs of different types of batteries. The sensor design allows it to be integrated with the battery without changing the original size and shape of the battery and affecting the normal use of the battery.

6. The battery expansion monitoring sensor according to any one of claims 1 to 5, wherein: The flexible material can be polydimethylsiloxane (PDMS) or other flexible materials, which are used to seal the gold nanowires, protect their stability, and improve the flexibility of the sensor.

7. The battery expansion monitoring sensor according to any one of claims 1 to 6, wherein: The sensor monitors the change of reflected light through SPR intensity demodulation technology to determine the degree of battery expansion.

8. A method for preparing the battery expansion monitoring sensor according to any one of claims 1 to 7, comprising the following steps: Gold nanowires are prepared, mixed with a flexible material solution, the mixed solution is laid on the surface of the nano-optical fiber by pulling, and the sensor module is formed by drying and curing.

9. The method according to claim 8, wherein: The preparation of gold nanowires includes depositing chromium, gold and aluminum layers by three magnetron sputtering processes, preparing a gold nanowire array by electrodeposition, and dispersing the gold nanowire array to obtain uniformly distributed gold nanowires.

10. The method according to any one of claims 8 to 9, wherein: The gold nanowire clumps that were not effectively dispersed were removed by centrifugation to obtain a stably dispersed gold nanowire solution.

Images