CN115950841A - A dislocation optical fiber sensor and supercapacitor charge and discharge monitoring system - Google Patents

Abstract

A dislocation optical fiber sensor and a supercapacitor charging and discharging monitoring system belong to the technical field of supercapacitors. The present invention solves the problems of poor accuracy and complicated methods in the prior art for monitoring the real-time working state of supercapacitors. Including: the optical fiber sensor is packaged inside the supercapacitor, the two ends are respectively connected to the light source and the spectrometer, and the electrodes of the supercapacitor are respectively connected to the corresponding electrodes of the electrochemical workstation; the incident light beam of the light source passes through the second section of single-mode fiber, and the first section of single-mode fiber The optical fiber and the second section of single-mode fiber are split at the dislocation fusion point. After the splitting, the first beam enters the electrolyte of the supercapacitor, and the second beam enters the cladding of the first section of single-mode fiber. The first beam and the second The second light beam is coupled at the dislocation fusion joint of the first section of single-mode fiber and the third section of single-mode fiber; during the charging and discharging process, the spectral wavelength output by the spectrometer is detected. The invention is used for on-line monitoring of charging and discharging of supercapacitors.

Description

A misplaced optical fiber sensor and supercapacitor charge and discharge monitoring system

technical field

The invention relates to an optical fiber sensor and a supercapacitor charging and discharging monitoring system based on the optical fiber sensor, belonging to the technical field of supercapacitors.

Background technique

With the renewal of electronic equipment and the rapid development of the new energy vehicle market, vigorously developing environmentally friendly high-performance energy storage devices has become one of the important issues for the sustainable development of the world economy today. As a new type of green energy storage device, supercapacitors have shown great application potential or prospects in many fields. Supercapacitors, also known as electrochemical capacitors, work on the principle of storing electrical energy using the electric double layer formed on the electrode surface or the two-dimensional or quasi-two-dimensional Faraday reaction that occurs. The research fields involve energy, materials, chemistry and electronic devices, etc., becoming one of the research hotspots of interdisciplinary research.

How to further improve the working efficiency of supercapacitors is an important problem that needs to be solved urgently. For example, people urgently need to develop sensors that can intuitively and real-time respond to their working status, and remind users to replace them in time before the performance of the capacitor drops to damage, so as to realize the efficient and safe operation of the device.

However, in the prior art, the sensor for real-time monitoring of the working state of the supercapacitor charging and discharging process generally adopts the sensing structure of the tilted fiber grating surface plasmon resonance technology. The problems of this sensing structure are:

1. It is necessary to make a tilted grating, and at the same time, it is necessary to coat the surface of the optical fiber with a gold film to excite surface plasmon waves. This method is relatively complicated;

2. The sensitivity of this sensing structure is low, and for supercapacitors, the change in refractive index caused by the change of charge density is very weak, and the sensor with low sensitivity cannot accurately obtain the monitoring results.

Contents of the invention

The purpose of the present invention is to solve the problems of poor accuracy and complex methods in the existing methods for monitoring the real-time working state of supercapacitors, and provide a dislocation optical fiber sensor and supercapacitor charging and discharging monitoring system.

A misplaced optical fiber sensor according to the present invention, which comprises: three sections of single-mode optical fiber arranged in misplaced positions, the two ends of the first section of single-mode optical fiber are breakpoints, and the second section of single-mode optical fiber is respectively dislocated and welded on the two breakpoints. Mode optical fiber and the third section of single-mode optical fiber, the optical fiber structures at the two dislocation fusion points are symmetrical to the center point of the first section of single-mode optical fiber.

Preferably, the dislocation amount of the dislocation fusion splicing point on the first section of single-mode optical fiber is set to 62.5 μm.

Preferably, the fiber length of the first section of single-mode fiber is in the range of 150-450 μm.

The supercapacitor charge and discharge monitoring system based on the dislocation optical fiber sensor of the present invention includes: an optical fiber sensor, a light source, an electrochemical workstation and a spectrometer;

The fiber optic sensor is packaged inside the supercapacitor to be tested, and the two ends of the fiber optic sensor are respectively connected to a light source and a spectrometer, and the electrodes of the supercapacitor are respectively connected to the corresponding electrodes of the electrochemical workstation;

The light beam incident from the light source to the fiber optic sensor passes through the second section of single-mode fiber, and is split at the dislocation fusion joint between the first section of single-mode fiber and the second section of single-mode fiber. In the liquid, the second light beam is incident on the cladding of the first section of single-mode fiber, and the first light beam and the second light beam are coupled at the dislocation fusion splicing point of the first section of single-mode fiber and the third section of single-mode fiber;

The electrochemical workstation controls the supercapacitor under test to realize charging and discharging through the electrodes. During the charging and discharging process, it detects the spectral wavelength output by the spectrometer to realize the monitoring of the supercapacitor charging and discharging process.

Preferably, the electrode of supercapacitor comprises working electrode, auxiliary electrode and reference electrode; Working electrode, auxiliary electrode and reference electrode are respectively connected to the corresponding electrode of electrochemical workstation; catch.

Preferably, the output spectrum range of the light source is 1250-1700 nm, and the output spectrum range of the light source matches the transmission spectrum envelope range of the optical fiber sensor.

Preferably, the electrochemical workstation uses cyclic voltammetry to control the charging and discharging process of the supercapacitor, and the electrochemical workstation changes the refractive index of the electrolyte on the electrode surface by controlling the amount of charge on the electrode surface, thereby causing the spectral wavelength output by the spectrometer to drift , to detect the wavelength drift, to realize the monitoring of the supercapacitor power storage and power discharge process, that is, to realize the monitoring of the supercapacitor charging and discharging process.

Preferably, when the supercapacitor is charged, the material of the supercapacitor electrode reacts to store electricity, the charge density near the electrode increases, and the refractive index changes;

When the supercapacitor is discharged, the material of the supercapacitor electrode reacts to release electricity, the charge density near the electrode decreases, and the refractive index returns to its original state.

Advantages of the present invention:

A dislocation optical fiber sensor proposed by the present invention adopts a dislocation fusion splicing structure, and the manufacturing method of the dislocation fusion splicing open cavity structure is simple, and there is no need to plate a gold film on the surface of the optical fiber. With a refractive index sensitivity exceeding 20,000nm/RIU, the highly sensitive sensor can more accurately detect changes in the refractive index.

The supercapacitor charge and discharge monitoring system based on the dislocation optical fiber sensor proposed by the present invention realizes real-time, Optical monitoring in situ. In addition, the long-distance online monitoring of the charging and discharging process of the supercapacitor can be realized by using the fiber optic sensor.

Description of drawings

Fig. 1 is the structural representation of dislocation type optical fiber sensor of the present invention;

Fig. 2 is the structural representation of supercapacitor charging and discharging monitoring system of the present invention;

Fig. 3 is a graph showing the change of wavelength in the spectrum during the process of controlling the charge and discharge process of the supercapacitor by cyclic voltammetry, wherein the abscissa represents time in s, and the ordinate represents the wavelength to be measured in nm;

Fig. 4 is the change curve of the interference wavelength to be measured corresponding to the process of controlling the charging and discharging process of the supercapacitor by cyclic voltammetry, wherein the abscissa represents the time, the unit is s, and the ordinate represents the wavelength to be measured, the unit is nm;

Fig. 5 is the transmission spectrum of the optical fiber sensor used for supercapacitor monitoring according to the present invention in pure water, wherein the abscissa represents the wavelength in nm, and the ordinate represents the intensity of the fiber sensor transmission spectrum in dB;

6 is a schematic diagram of wavelength drift with refractive index in the optical fiber sensor spectrum for supercapacitor monitoring according to the present invention, wherein the abscissa represents the refractive index of the liquid in RIU, and the ordinate represents the wavelength to be measured in nm.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

It should be noted that, in the case of no conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but not as a limitation of the present invention.

Example 1:

The present embodiment will be described below in conjunction with FIG. 1. A dislocation optical fiber sensor described in this embodiment,

It includes: three sections of single-mode optical fiber arranged in dislocation, the two ends of the first section of single-mode optical fiber 1-1 are breakpoints, and the second section of single-mode optical fiber 1-2 and the third section are dislocated and welded respectively at the two breakpoints For the single-mode optical fiber 1-3, the optical fiber structure at the two dislocation fusion points is symmetrical to the center point of the first section of single-mode optical fiber 1-1.

Further, the misalignment amount of the misalignment fusion splicing point on the first section of single-mode optical fiber 1-1 is set to 62.5 μm.

Still further, the fiber length of the first section of single-mode fiber 1-1 ranges from 150 to 450 μm.

In this embodiment, the dislocation optical fiber sensor used for supercapacitor monitoring is an open-cavity optical fiber sensor, which is made by dislocation fusion of an optical fiber fusion splicer; the dislocation structure includes three sections of single-mode optical fiber, and after one optical fiber is cut According to the parameter of dislocation amount of 62.5 μm, dislocation welding is carried out to complete the first welding point, and the first welding point is placed under the microscope, and the optical fiber is cut again according to the length of the dislocation area of 150-450 μm, and the parameter of dislocation amount is 62.5 μm again. For dislocation welding of the second welding point, the structure of the optical fiber after welding the two welding points is axisymmetric with the center line of the dislocation area.

The transmission spectrum of the optical fiber sensor in this embodiment in pure water is shown in Figure 5, and the transmissive optical fiber sensor made by the dislocation fusion structure has a refraction sensitivity exceeding 20000nm/RIU, as shown in Figure 6, so that the dislocation fusion splicing optical fiber sensor Transmission spectroscopy enables high-precision measurements of small refractive index changes.

Example 2:

The following describes this embodiment in conjunction with FIG. 2. The supercapacitor charge and discharge monitoring system based on the dislocation optical fiber sensor described in this embodiment,

It includes: an optical fiber sensor 1, a light source 2, an electrochemical workstation 7 and a spectrometer 8;

The optical fiber sensor 1 is packaged inside the supercapacitor 3 to be measured, the two ends of the optical fiber sensor 1 are respectively connected to a light source 2 and a spectrometer 8, and the electrodes of the supercapacitor 3 are respectively connected to the corresponding electrodes of the electrochemical workstation 7;

The light beam incident on the optical fiber sensor 1 from the light source 2 passes through the second section of single-mode fiber 1-2, and is split at the dislocation fusion splicing point between the first section of single-mode fiber 1-1 and the second section of single-mode fiber 1-2. The first light beam is incident on the electrolyte inside the supercapacitor 3, the second light beam is incident on the cladding of the first section of single-mode fiber 1-1, the first light beam and the second light beam are in the first section of single-mode fiber 1-1 1 and the third section of single-mode fiber 1-3 for coupling at the dislocation fusion splicing point;

The electrochemical workstation 7 controls the supercapacitor 3 under test to realize charging and discharging through the electrodes. During the charging and discharging process, the spectral wavelength output by the spectrometer 8 is detected to realize the monitoring of the charging and discharging process of the supercapacitor 3 .

Further, the electrodes of supercapacitor 3 include working electrode 4, auxiliary electrode 5 and reference electrode 6; working electrode 4, auxiliary electrode 5 and reference electrode 6 are respectively connected to the corresponding electrodes of electrochemical workstation 7; The sensitive area is in contact with the working electrode 4 of the supercapacitor 3 .

Still further, the output spectrum range of the light source 2 is 1250-1700 nm, and the output spectrum range of the light source 2 matches the transmission spectrum envelope range of the optical fiber sensor 1 .

Furthermore, the electrochemical workstation 7 uses cyclic voltammetry to control the charging and discharging process of the supercapacitor 3. The electrochemical workstation 7 changes the refractive index of the electrolyte on the electrode surface by controlling the amount of charge on the electrode surface, thereby making the spectrometer 8 output The wavelength of the spectral spectrum drifts, and the wavelength drift is detected to realize the monitoring of the power storage and power discharge process of the super capacitor 3, that is, the monitoring of the charging and discharging process of the super capacitor 3 is realized.

Furthermore, when charging the supercapacitor 3, the material of the electrode of the supercapacitor 3 reacts to store electricity, the charge density near the electrode increases, and the refractive index changes;

When the supercapacitor 3 is discharged, the material of the electrode of the supercapacitor 3 reacts to discharge electricity, the charge density near the electrode decreases, and the refractive index returns to its original state.

In this embodiment, the open-cavity optical fiber sensor monitors the charging and discharging process of the supercapacitor 3. Its structure is sequentially connected to the light source 2, the optical fiber sensor 1, and the spectrometer 8. It also includes a supercapacitor 3 and an electrochemical workstation 7, of which there are three supercapacitors 3 The electrodes are connected to the electrochemical workstation 7 . One bit of the fiber optic sensor is packaged inside the supercapacitor 3 , and the sensing area of the fiber optic sensor 1 is close to the working electrode of the supercapacitor 3 . The electrodes of the supercapacitor 3 are respectively connected to the corresponding electrodes of the electrochemical workstation 7 , wherein the working electrodes are close to the sensing area of the optical fiber sensor 1 .

In this embodiment, the open-cavity optical fiber sensor 1 monitors the charging and discharging state of the supercapacitor 3, in which the light emitted by the light source 2 realizes light splitting at the first dislocation welding point, part of it passes through the solution in the open cavity, and part of it passes through the dislocation welding In the cladding of the fiber, the two parts of the light are recoupled into the fiber core at the second dislocation fusion point, thereby achieving interference.

When the supercapacitor 3 is charged and discharged, the ions in the electrolyte enter the two-dimensional or three-dimensional space of the electrode active material when storing and discharging electricity, and redox reactions occur in the two-dimensional or three-dimensional space of the electrode active material, resulting in a change in the refractive index of the electrode active material, resulting in a change in the wavelength of the optical fiber sensor 1 spectrum. Drift occurs, so that real-time in-situ monitoring of the charging and discharging working status of the supercapacitor is realized.

In this embodiment, when the supercapacitor 3 is charging and discharging, the ions in the electrolyte enter the two-dimensional or three-dimensional space of the electrode active material to undergo a redox reaction when storing and discharging electricity, resulting in a change in the refractive index of the electrode active material, resulting in The wavelength of the spectrum of the optical fiber sensor 1 drifts, thereby realizing real-time in-situ monitoring of the charging and discharging working state of the supercapacitor.

Furthermore, the working electrode 4 is made of carbon cloth coated with manganese dioxide, with a size of 1cm×1cm. In order to make the optical fiber sensor 1 closer to the carbon cloth, two carbon cloths of the same size are used to clamp the optical fiber sensor 1 in the middle , creating a tighter close-in effect.

The auxiliary electrode 5 is made of platinum sheet, and the reference electrode 6 is made of silver chloride reference electrode; the three electrodes are connected with the corresponding electrodes of the electrochemical workstation 7 .

The electrochemical workstation 7 adjusts the voltage and current, uses cyclic voltammetry to perform electrochemical tests, and the supercapacitor 3 is charged cyclically, resulting in changes in the charge density on the surface of the working electrode 4, causing changes in the refractive index of the environment, and changes in the refractive index of the environment make the optical fiber sensor 1 The optical path at the open cavity is affected, and the wavelength shifts as a result of interference. This phenomenon can be observed in the spectrometer 8. Using this system, the optical quantity can reflect the stored power information of the supercapacitor.

In the present invention, the specific method for realizing supercapacitor charge and discharge monitoring using the supercapacitor charge and discharge monitoring system based on the dislocation optical fiber sensor described in the present invention includes:

S1, the optical fiber sensor 1 is packaged inside the supercapacitor 3, and the light source 2 and the spectrometer 8 are respectively connected at both ends of the optical fiber sensor 1, and the optical fiber sensor 1 is close to the working electrode of the supercapacitor 3;

Fill the supercapacitor 3 with electrolyte;

The open cavity of the optical fiber sensor 1 is filled with electrolyte, and the light emitted by the light source 2 passes through the front end of the optical fiber sensor 1, and is divided into two beams of light, one beam passes through the electrolyte solution, and the other beam passes through the fiber cladding, and interference occurs at the rear end. Interference fringes are formed, which fringes are observed by the spectrometer 8;

S2. Build a device and a detection circuit, connect the supercapacitor 3 to the electrochemical workstation 7, connect the electrochemical workstation 7 to a computer, and control the indoor temperature to a normal constant temperature;

S3. Static monitoring system under natural conditions, while using optical and electrical methods to detect the whole process of changes in the amount of charge stored in the supercapacitor device during charging and discharging;

S4. Perform cyclic voltammetry detection on the supercapacitor 3 through the electrochemical workstation 7 to control the charging and discharging behavior of the supercapacitor 3, thereby controlling the amount of charge on the electrode surface, causing the environmental refractive index of the surface to change, resulting in a shift in the spectral wavelength, through Wavelength drift detection of the whole process of storage and release of electricity when the supercapacitor is charged and discharged;

As shown in Figure 3, when cyclic voltammetry is performed at a scan rate of 10mV/s, when the amount of stored charge increases, the spectral wavelength shifts to the short-wave direction, and when the stored charge decreases, the spectrum recovers to the long-wave direction.

As shown in Figure 4, the supercapacitor 3 is subjected to multi-cycle cyclic voltammetry tests under the excitation of the electrochemical workstation 7, and the wavelength change corresponding to a certain interference fringe trough is recorded. In each cycle, the optical fiber sensor 1 presents The good symmetry and the reciprocity of the wavelength drift change show that the sensor has good cycle stability for the supercapacitor monitoring system and method.

Further, the whole process of using optical and electrical methods to detect changes in the amount of charge stored in the supercapacitor device during charging and discharging described in S3 includes:

When charging the supercapacitor 3, the electrode material reacts to store electricity, the charge density near the electrode increases, and the refractive index changes; when discharging, the electrode material releases electricity, and the refractive index of the reactant recovers. The charge density will also decrease;

The electrochemical workstation 7 and the fiber optic spectrometer 8 record the whole process of charging and discharging of the fiber optic supercapacitor device, and draw a one-to-one corresponding graph.

Further, the refractive index change caused by the charge density change on the surface of the fiber optic electrode in S4 is sensitive to the environmental refractive index change in the transmission spectrum wavelength of the open-cavity fiber sensor, thus converting the measurement of the electric quantity information into an optical-electrochemical signal for measurement .

Although the invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely illustrative of the principles and applications of the invention. It is therefore to be understood that numerous modifications may be made to the exemplary embodiments and that other arrangements may be devised without departing from the spirit and scope of the invention as defined by the appended claims. It shall be understood that different dependent claims and features described herein may be combined in a different way than that described in the original claims. It will also be appreciated that features described in connection with individual embodiments can be used in other described embodiments.

Claims (8)

1. A dislocation type optical fiber sensor is characterized in that it comprises: three sections of single-mode optical fiber provided by dislocation, the two ends of the first section of single-mode optical fiber (1-1) are breakpoints, respectively on two breakpoints The second section of single-mode fiber (1-2) and the third section of single-mode fiber (1-3) are spliced by dislocation, and the fiber structure at the two dislocation fusion points is based on the center point of the first section of single-mode fiber (1-1). symmetry. 2. A dislocation-type optical fiber sensor according to claim 1, characterized in that the dislocation amount of the dislocation fusion splicing point on the first section of single-mode optical fiber (1-1) is set to 62.5 μm. 3 . The dislocation optical fiber sensor according to claim 1 , characterized in that, the optical fiber length of the first section of single-mode optical fiber ( 1 - 1 ) ranges from 150 to 450 μm. 4 . 4. based on the supercapacitor charging and discharging monitoring system of the said misplaced optical fiber sensor of claim 1, it is characterized in that it comprises: optical fiber sensor (1), light source (2), electrochemical workstation (7) and spectrometer (8); The fiber optic sensor (1) is packaged inside the supercapacitor (3) to be tested, the two ends of the fiber optic sensor (1) are respectively connected to a light source (2) and a spectrometer (8), and the electrodes of the supercapacitor (3) are respectively connected to the electric The corresponding electrode of the chemical workstation (7); The light beam incident on the optical fiber sensor (1) from the light source (2) passes through the second section of single-mode fiber (1-2), the first section of single-mode fiber (1-1) and the second section of single-mode fiber (1-2) Split the beam at the dislocation welding point of the split, the first beam after splitting is incident on the electrolyte inside the supercapacitor (3), the second beam is incident on the cladding of the first section of single-mode optical fiber (1-1), and the first The light beam and the second light beam are coupled at the dislocation fusion splicing point of the first section of single-mode fiber (1-1) and the third section of single-mode fiber (1-3); The electrochemical workstation (7) controls the supercapacitor (3) under test to realize charging and discharging through the electrodes, and detects the spectral wavelength output by the spectrometer (8) during the charging and discharging process, so as to monitor the charging and discharging process of the supercapacitor (3). 5. supercapacitor charging and discharging monitoring system according to claim 4, is characterized in that, the electrode of described supercapacitor (3) comprises working electrode (4), auxiliary electrode (5) and reference electrode (6); Electrode (4), auxiliary electrode (5) and reference electrode (6) are respectively connected to the corresponding electrode of electrochemical workstation (7); the sensing area of optical fiber sensor (1) and the working electrode (4) of supercapacitor (3) ) connected. 6. The supercapacitor charging and discharging monitoring system according to claim 4, characterized in that, the output spectral range of the light source (2) is 1250-1700nm, and the output spectral range of the light source (2) is the same as that of the optical fiber sensor (1) The transmission spectrum envelope is matched. 7. supercapacitor charging and discharging monitoring system according to claim 4, is characterized in that, described electrochemical workstation (7) adopts cyclic voltammetry to control the charging and discharging process of supercapacitor (3), electrochemical workstation (7) Change the refractive index of the electrolyte on the electrode surface by controlling the amount of charge on the electrode surface, and then cause the spectral wavelength output by the spectrometer (8) to drift, and detect the wavelength drift to realize the power storage and power discharge process of the supercapacitor (3) monitoring, that is, the monitoring of the charging and discharging process of the supercapacitor (3) is realized. 8. supercapacitor charging and discharging monitoring system according to claim 7, is characterized in that, When charging the supercapacitor (3), the material of the electrode of the supercapacitor (3) reacts to store electricity, the charge density near the electrode increases, and the refractive index changes; When the supercapacitor (3) is discharged, the material of the electrode of the supercapacitor (3) reacts to discharge electricity, the charge density near the electrode decreases, and the refractive index returns to the original state.

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