Method for improving electrochemical performance of organic small molecules and flow battery

Abstract

The application discloses a method for improving electrochemical performance of an organic small molecule and a flow battery, and relates to the technical field of organic flow batteries. The method for improving electrochemical performance comprises the following steps: arranging a magnetic field generating device on both sides of an electrolytic cell, adding an organic small molecule into the electrolytic cell, powering the electrolytic cell, and starting the magnetic field generating device to apply a magnetic field generated by the magnetic field generating device to the electrolytic cell; or arranging a magnetic field generating device around a flow battery, adding an organic small molecule into the flow battery, charging and discharging the flow battery, and starting the magnetic field generating device to apply a magnetic field generated by the magnetic field generating device to the flow battery. The application further provides a flow battery comprising an electrolyte, wherein the electrolyte contains the organic small molecule processed by the method. The application has the beneficial effect of improving the electrochemical performance of the organic small molecule by using a magnetic field to affect the loss and gain of electrons of a covalent bond of the organic small molecule, thereby improving the molecular diffusion speed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of organic flow battery, and particularly relates to a method for improving electrochemical performance of an organic small molecule and a flow battery. BACKGROUND

[0002] An organic flow battery (ORFB) is an energy storage technology that uses water-soluble or non-water-soluble organic molecules as active substances to realize energy storage and release through redox reactions. Its core structure includes positive / negative electrolyte storage tanks, reaction chambers, ion exchange membranes, and circulation systems. The design of separating electrolyte from the stack allows independent adjustment of energy and power, which is suitable for large-scale energy storage needs. According to the type of electrolyte solvent, ORFB is divided into two types: water-based and non-water-based. The former uses water as the solvent, which is safe and low in cost; the latter uses organic solvents (such as acetonitrile) as the solvent, which has higher energy density but needs to solve the problems of volatility and stability.

[0003] The core advantage of the organic flow battery is environmental protection and sustainability, which completely eliminates metal resources such as vanadium and chromium, and relies on chemically synthesized organic substances (such as anthraquinone and bipyridine derivatives), which have a wide range of raw material sources and low environmental risk. At the same time, water-based ORFB has intrinsic safety, non-flammable electrolyte, and no strong acid / alkali corrosion, and a wide working temperature range (some models can operate stably at 60℃), which is suitable for high-temperature or safety-critical scenarios.

[0004] Despite its potential, ORFB still faces technical bottlenecks. The existing ORFB technology has poor conductivity of organic small molecules, and the covalent bond redox reaction of organic small molecules has a complex and variable process of shifting or dynamic exchange of shared electrons, which results in low capacity utilization and energy efficiency of the battery under high current density. Therefore, there is an urgent need to design a method for improving the electrochemical performance of organic small molecules. SUMMARY

[0005] The present application aims to at least solve one of the technical problems in the prior art, and provides a method for improving the electrochemical performance of an organic small molecule and a flow battery, specifically a method for improving the electrochemical performance of an organic small molecule by using a magnetic field to affect the gain and loss of electrons in the covalent bond of the molecule, and a flow battery containing the organic small molecule.

[0006] Chinese patent CN 111326779 A discloses a method for improving the transmission performance of a eutectic solvent electrolyte flow battery and a flow battery. The patent is to place the eutectic solvent electrolyte flow battery in a magnetic field of 165mT-605mT, so that the charged particles in the electrolyte are affected by the Lorentz force, the ion movement rate is improved, and the conductivity of the flow battery is improved. Chinese patent CN 117558957 A discloses a magnetic management paramagnetic reaction ion flow battery system and performance improvement method. The patent is to make the electrolyte entering the flow battery flow through or seep into the magnetic porous electrode with gradient magnetic field inside and surface, thereby improving the electrical energy efficiency of the battery. Although the above two patents disclose a method of treating electrolyte with magnetic field, the above patent uses magnetic field to affect ionic bond. Ionic bond is generated by atoms getting or losing electrons to form anions or cations, and then the anions and cations form through electrostatic interaction. There is no method in the prior art for using magnetic field to affect molecular covalent bond to improve molecular electrochemical performance.

[0007] The present application provides a method for improving the electrochemical performance of organic small molecules by using magnetic field to affect the gain and loss of electrons of molecular covalent bond. Covalent bond is formed by atoms sharing electron pairs, and there is no gain or loss of electrons between atoms. There are no anions and cations in the formed compound. Compared with the above patent, the difference of the present application is that the directionality of ionic bond and covalent bond is different when the bond is formed. Ionic bond has no directionality when the bond is formed, while covalent bond has directionality. The charge attraction distribution of anions and cations is spherical symmetry, and one ion can attract ions with opposite charge in any direction, so ionic bond has no directionality. Covalent bond is quite different. The formation of covalent bond is the overlap of the electron clouds of the bonding atoms. The more the degree of electron cloud overlap, the greater the electron cloud density between the two nuclei, and the more stable the covalent bond formed. Therefore, the formation of covalent bond will be along the direction with the maximum electron cloud density as much as possible. Except that the electron cloud of s orbital is spherical symmetry and has no directionality when overlapping with each other, the electron clouds of p, d and f orbitals have certain stretching direction in space, so they have directionality when the bond is formed. The directionality of covalent bond determines the spatial arrangement of atoms in the molecule. Whether the atomic arrangement is symmetrical or not plays an important role in determining the polarity of the molecule. The present application uses magnetic field to affect the overlapping part of the electron cloud of covalent bond and the directionality of covalent bond. In addition, the bond energy of covalent bond is generally higher than that of ionic bond. The energy of magnetic field can reduce the bond energy level of covalent bond and the activation energy of redox reaction, thereby improving the reversibility of the reaction.

[0008] The technical solution of the present application is as follows:

[0009] The first aspect of the present application provides a method for improving the electrochemical performance of organic small molecules, comprising the following steps:

[0010] The magnetic field generating device is arranged on both sides of the electrolytic cell, the organic small molecule is added into the electrolytic cell, the electrolytic cell is powered on, and the magnetic field generated by the magnetic field generating device is applied to the electrolytic cell, and the magnetic field reduces the reaction activation energy of the organic small molecule and improves the diffusion speed of the organic small molecule by affecting the ability of the organic small molecule to lose or gain electrons.

[0011] Alternatively, a magnetic field generating device is arranged around the flow battery, an organic small molecule is added into the flow battery, the flow battery is charged and discharged, and the magnetic field generated by the magnetic field generating device is applied to the flow battery, and the magnetic field reduces the reaction activation energy of the organic small molecule and improves the diffusion speed of the organic small molecule by affecting the ability of the organic small molecule to lose or gain electrons.

[0012] Preferably, the organic small molecule comprises at least one of TEMPO derivative, ferrocene derivative, viologen derivative, quinone derivative, phenazine derivative, phenothiazine derivative, and phenoxazine derivative.

[0013] Preferably, the organic small molecule is added into the electrolytic cell or the flow battery in the form of an organic small molecule solution, wherein the organic small molecule solution is prepared in the following manner:

[0014] The organic small molecule is dissolved in water to obtain the organic small molecule solution.

[0015] The concentration of the organic small molecule in the organic small molecule solution is 0.05mmol / L-4mmol / L.

[0016] Preferably, the organic small molecule solution further contains an electrolyte, and when the electrolyte is contained, the organic small molecule solution is prepared in the following manner:

[0017] The organic small molecule and the electrolyte are dissolved in water to obtain the organic small molecule solution.

[0018] The concentration of the electrolyte in the organic small molecule solution is 0.05mol / L-3mol / L.

[0019] Preferably, the strength of the magnetic field ranges from 0.1T to 0.5T.

[0020] Preferably, the magnetic field is continuously applied during the operation of the battery.

[0021] Preferably, the magnetic field is applied vertically to the electrode of the electrolytic cell or the bipolar plate of the flow battery.

[0022] Preferably, the electrochemical performance enhancement method further includes: firstly, placing the organic small molecules in an external magnetic field for pre-magnetization treatment, thereby weakening the hydrogen bonding between the organic small molecules and water molecule clusters through the external magnetic field, wherein the pre-magnetization treatment includes the following steps:

[0023] A magnetic field generator is arranged around the flow battery to generate an external magnetic field. The organic small molecules are added to the flow battery and kept in a flowing state inside the flow battery. Under the action of the external magnetic field, the organic small molecules are pre-magnetized while flowing.

[0024] Preferably, the pre-magnetization intensity ranges from 0.1T to 0.5T, and the pre-magnetization time is from 6h to 24h.

[0025] A second aspect of the present invention provides a flow battery comprising an electrolyte containing small organic molecules treated by the method described above.

[0026] This invention has at least one of the following beneficial effects:

[0027] This invention improves the electrochemical performance of small organic molecules by placing a magnetic field generator near the solution and applying a magnetic field to it. This magnetic field influences the gain and loss of electrons in the covalent bonds of the small organic molecules, thereby lowering their activation energy and increasing their diffusion rate. Consequently, when the electrolyte flows through the magnetic field in a flow battery, the small organic molecules in the electrolyte diffuse faster under the magnetic force, further enhancing battery performance. This invention addresses the low capacity utilization and energy efficiency of existing organic flow battery technologies, achieving improved capacity utilization and energy efficiency without altering other battery components. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the CV curves of the TEMPO derivatives in Example 1 with and without a magnetic field in Comparative Example 1.

[0029] Figure 2 This is a schematic diagram of the CV curves of the ferrocene derivative in Example 1 with and without a magnetic field in Comparative Example 1.

[0030] Figure 3 This is a schematic diagram of the CV curves of viologen derivatives in Example 1 with and without a magnetic field in Comparative Example 1.

[0031] Figure 4 This is a schematic diagram of the CV curves of quinone derivatives in Example 1 with and without a magnetic field in Comparative Example 1;

[0032] Figure 5 Figure 2 is a graph showing the rate capability of a battery using a TEMPO derivative in the presence of a magnetic field in Example 2 and in the absence of a magnetic field in Comparative Example 2;

[0033] Figure 6 Figure 3 is a graph showing the long cycle capability of a battery using a TEMPO derivative in the presence of a magnetic field in Example 2 and in the absence of a magnetic field in Comparative Example 2;

[0034] Figure 7 Figure 4 is a graph showing the voltage of a battery using a TEMPO derivative in the presence of a magnetic field in Example 2 and in the absence of a magnetic field in Comparative Example 2;

[0035] Figure 8 Figure 5 is a graph showing the rate capability of a battery using a ferrocene derivative in the presence of a magnetic field in Example 2 and in the absence of a magnetic field in Comparative Example 2;

[0036] Figure 9 Figure 6 is a graph showing the long cycle capability of a battery using a ferrocene derivative in the presence of a magnetic field in Example 2 and in the absence of a magnetic field in Comparative Example 2. DETAILED DESCRIPTION

[0037] In order to make the technical problems solved by the present application, technical solutions and beneficial effects more clearly understood, the present application will be further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application, and are not used to limit the present application.

[0038] An embodiment of the present application provides a method for improving the electrochemical performance of an organic small molecule, comprising the following steps:

[0039] A magnetic field generating device is arranged on both sides of an electrolytic cell, an organic small molecule is added to the electrolytic cell, the electrolytic cell is powered on, and the magnetic field generating device is turned on, and the magnetic field generated by the magnetic field generating device is applied to the electrolytic cell, and the magnetic field improves the molecular diffusion speed by affecting the gain and loss of electrons of the covalent bond of the organic small molecule;

[0040] Alternatively, a magnetic field generating device is arranged around a flow battery, an organic small molecule is added to the flow battery, the flow battery is charged and discharged, and the magnetic field generating device is turned on, and the magnetic field generated by the magnetic field generating device is applied to the flow battery, and the magnetic field improves the molecular diffusion speed by affecting the gain and loss of electrons of the covalent bond of the organic small molecule.

[0041] The application improves the diffusion coefficient of the organic small molecule by applying a magnetic field near the organic small molecule, using the magnetic field to affect the covalent bond of the organic small molecule to lose electrons, thereby improving the electrochemical performance of the organic small molecule. The technical problems solved by the application include the problems of low battery capacity utilization rate and energy efficiency in the existing organic flow battery technology, and the purpose of improving the battery capacity utilization rate and energy efficiency without changing other components of the battery.

[0042] In some embodiments, the organic small molecule includes at least one of TEMPO derivatives, ferrocene derivatives, viologen derivatives, quinone derivatives, phenazine derivatives, phenothiazine derivatives, and phenoxazine derivatives.

[0043] Specifically, the structural formula of the TEMPO derivatives, ferrocene derivatives, viologen derivatives, quinone derivatives, phenazine derivatives, phenothiazine derivatives, and phenoxazine derivatives is as follows:

[0044] Viologen derivatives: ;

[0045] TEMPO derivatives: ;

[0046] Ferrocene derivatives: ;

[0047] Quinone derivatives: ;

[0048] Phenazine derivatives: ;

[0049] Phenothiazine derivatives: ;

[0050] Phenoxazine derivatives: ;

[0051] In some embodiments, the organic small molecule is added to the electrolytic cell or flows into the flow battery in the form of an organic small molecule solution, and the preparation method of the organic small molecule solution includes:

[0052] dissolving the organic small molecule in water to obtain the organic small molecule solution;

[0053] The concentration of the organic small molecule in the organic small molecule solution is 0.05mmol / L-4mmol / L.

[0054] Preferably, the concentration of the organic small molecule is 0.05 mmol / L to 3.5 mmol / L; more preferably, the concentration of the organic small molecule is 0.05 mmol / L to 3 mmol / L. Specifically, it can be 0.05 mmol / L, 0.5 mmol / L, 1 mmol / L, 2 mmol / L, 2.5 mmol / L, 3 mmol / L, 3.5 mmol / L, and 4 mmol / L, etc.

[0055] In some embodiments, the organic small molecule solution further contains an electrolyte. When the electrolyte is contained, the preparation method of the organic small molecule solution comprises:

[0056] dissolving the organic small molecule and the electrolyte in water to obtain the organic small molecule solution;

[0057] In the organic small molecule solution, the concentration of the electrolyte is 0.05 mol / L to 4 mol / L.

[0058] The electrolyte comprises sodium chloride.

[0059] Preferably, the concentration of the electrolyte is 0.05 mol / L to 2.5 mol / L; more preferably, the concentration of the electrolyte is 2 mol / L.

[0060] Specifically, the TEMPO derivative is dissolved in a solution, and the solution generally also contains a supporting electrolyte. The magnetic field promotes the electron gain and loss on the nitrogen-oxygen covalent bond of the TEMPO derivative to improve the electrochemical performance of the TEMPO derivative.

[0061] Specifically, the ferrocene derivative is dissolved in a solution, and the solution generally also contains a supporting electrolyte. The electron gain and loss on the iron-carbon covalent bond of the ferrocene derivative improves the electrochemical performance of the ferrocene derivative.

[0062] Specifically, the viologen derivative is dissolved in a solution, and the solution generally also contains a supporting electrolyte. The electron gain and loss on the nitrogen-carbon covalent bond of the viologen derivative improves the electrochemical performance of the viologen derivative.

[0063] Specifically, the quinone derivative is dissolved in a solution, and the solution generally also contains a supporting electrolyte. The electron gain and loss on the nitrogen-oxygen covalent bond of the quinone derivative improves the electrochemical performance of the quinone derivative.

[0064] Specifically, the phenoxazine derivative is dissolved in a solution, and the solution generally also contains a supporting electrolyte. The electron gain and loss on the nitrogen-carbon covalent bond of the phenoxazine derivative improves the electrochemical performance of the phenoxazine derivative.

[0065] Specifically, the phenothiazine derivative is dissolved in a solution, and the solution generally also contains a supporting electrolyte. The electron gain and loss on the nitrogen-carbon covalent bond of the phenothiazine derivative improves the electrochemical performance of the phenothiazine derivative.

[0066] Specifically, the phenoxazine derivative is dissolved in a solution, which also generally contains a supporting electrolyte. Electrons are gained or lost from the nitrogen-carbon covalent bond of the phenoxazine derivative to enhance the electrochemical performance of the phenoxazine derivative.

[0067] In some embodiments, the magnetic field strength ranges from 0.1T to 0.5T. Preferably, the range is from 0.2T to 0.31T.

[0068] In some embodiments, the magnetic field is continuously applied during the operation of the battery.

[0069] In some embodiments, the magnetic field is applied perpendicularly to the electrodes of the electrolytic cell or to the bipolar plate of the flow battery.

[0070] In some embodiments, the organic small molecule is also subjected to a pre-magnetization treatment before being added to the electrolytic cell or the flow battery, and the method of the pre-magnetization treatment comprises:

[0071] The organic small molecule is placed in an external magnetic field for pre-magnetization treatment, and the hydrogen bonding between the organic small molecule and water clusters is weakened by the external magnetic field.

[0072] The pre-magnetization treatment specifically comprises the following steps:

[0073] A magnetic field generating device is arranged around the flow battery to generate an external magnetic field, the organic small molecule is added to the flow battery and kept in a flowing state inside the flow battery, and under the action of the external magnetic field, the organic small molecule is subjected to pre-magnetization treatment while flowing.

[0074] In some embodiments, the strength of the pre-magnetization treatment ranges from 0.1T to 0.5T. Preferably, the range is from 0.2T to 0.31T. The pre-magnetization treatment time is 6h to 24h. Preferably, the range is 12h to 24h.

[0075] In some embodiments, the magnetic field generating device comprises a permanent magnet or an electromagnet, i.e. the magnetic field can be generated by arranging a magnetic field generator such as a permanent magnet or an electromagnet.

[0076] The principle of the present application comprises: by arranging a magnetic field generating device on both sides of the electrolytic cell or around the flow battery, the magnetic field generated by the magnetic field generating device can orient the direction of the electron spin on the covalent bond of the organic small molecule. According to the principle of quantum mechanics, the spin of an electron can only exist in a specific direction (up spin and down spin), but cannot rotate in any direction. When a magnetic field exists, it will exert a force on the electron spin, making the spin tend to be in the same direction or opposite direction as the magnetic field. This force is called spin field. The orientation of the electron spin direction on the covalent bond of the organic small molecule is changed from chaotic to directional, which increases the stability of the molecule.

[0077] And the magnetic field will affect the energy level of the electron spin. According to the principle of quantum mechanics, the spin of the electron is closely linked with the orbital motion, which determines the energy level structure of the electron together. When an electron is in a magnetic field, the magnetic field will couple the electron spin and the orbital motion, thereby changing the energy level of the electron. This phenomenon is called spin-orbit coupling. Under the action of the magnetic field, the energy level interval of the gain and loss of electrons of the covalent bond of the organic small molecule is narrowed, the energy required for the gain and loss of electrons is less, and the overpotential is also reduced, and the electrochemical performance is improved.

[0078] The influence of magnetic force includes the influence of Lorentz force and Kelvin force on the organic small molecule, wherein,

[0079] (1) The influence of Lorentz force on the organic small molecule can be obtained by the following formula:

[0080] Wherein, F L is the Lorentz force, q and E represent the charge and the electric field intensity, v indicates the velocity of the charged particle, and B is the magnetic field intensity.

[0081] (2) The influence of Kelvin force on the organic small molecule can be obtained by the following formula:

[0082] Wherein, F K is the Kelvin force, is the magnetic constant in free space, c indicates the concentration of paramagnetic organic small molecule substance, is the molar magnetic susceptibility, is the magnetic field gradient.

[0083] Another embodiment of the present application provides a flow battery comprising an electrolyte containing the organic small molecule obtained after the method.

[0084] The present application can improve the battery capacity utilization and energy efficiency by treating the organic small molecule with a magnetic field without changing the flow battery and its components.

[0085] In some embodiments, the flow battery mainly consists of a transfusion pump, a storage tank, an electric pile and other pipelines, and the electric pile is mainly assembled by a current collector, a bipolar plate, an electrode and a diaphragm.

[0086] The present application will be further described in detail with specific embodiments, but the present application is not limited to the following specific embodiments.

[0087] Example 1:

[0088] A method for improving the electrochemical performance of an organic small molecule by using a magnetic field to affect the loss and gain of electrons of the covalent bond of the molecule, comprising the following steps:

[0089] Dissolving the organic small molecule TEMPO derivative and the electrolyte in water to obtain a TEMPO derivative solution; the concentration of the TEMPO derivative solution is 2 mmol / L, and the electrolyte is a sodium chloride solution with a concentration of 2 mol / L.

[0090] Adding the TEMPO derivative solution into an electrolytic cell, and arranging a magnetic field generating device on both sides of the electrolytic cell. The electrochemical performance of the TEMPO derivative solution is tested by cyclic voltammetry of a three-electrode system, using carbon felt as the working electrode, platinum wire as the auxiliary electrode, and silver chloride as the reference electrode, and the scan rate is constant at 100 mv / s. In this embodiment, a permanent magnet is used to generate the magnetic field, the strength of the permanent magnet is N35 (the maximum magnetic energy product is about 35 MGOe), the distance between the permanent magnets is 30 cm, the magnetic field is applied vertically to the surface of the carbon felt working electrode, the strength of the applied magnetic field is 0.21 T, and the time of the magnetic field treatment is 1 h.

[0091] Replacing the “TEMPO derivative” with ferrocene derivative, viologen derivative and quinone derivative respectively, and using the same method as described above to perform magnetic field treatment on the ferrocene derivative, viologen derivative and quinone derivative.

[0092] Example 2:

[0093] A method for improving the electrochemical performance of an organic small molecule by using a magnetic field to affect the loss and gain of electrons of the covalent bond of the molecule, comprising the following steps:

[0094] Dissolving the organic small molecule TEMPO derivative and the electrolyte in water to obtain a TEMPO derivative electrolyte solution; the concentration of the TEMPO derivative electrolyte solution is 0.05 mol / L, and the electrolyte is a sodium chloride solution with a concentration of 2 mol / L.

[0095] Arranging a magnetic field perpendicular to the bipolar plate of the flow battery around the flow battery, making the TEMPO derivative electrolyte flow into the flow battery, and testing the charging and discharging performance of the TEMPO derivative electrolyte. The flow battery mainly consists of a liquid delivery pump, a storage tank, an electric pile and other pipelines, and the electric pile is mainly assembled by a current collector, a bipolar plate, an electrode and a separator. In this embodiment, a permanent magnet is used to generate the magnetic field, the strength of the permanent magnet is N52 (the maximum magnetic energy product is about 52 MGOe), the distance between the permanent magnets is 30 cm, the strength of the applied magnetic field is 0.26 T, and the time of the magnetic field treatment is 1 h. The test is divided into rate performance test and long cycle performance test, and the rate performance test is carried out at 20 mA cm -2 -160 mA cm -2The short cycle was tested at 80 mA cm -2 The short cycle was tested at 80 mA cm

[0096] The "TEMPO derivative" was replaced with a ferrocene derivative, the permanent magnet strength was N45 (the maximum magnetic energy product was about 45 MGOe), the distance was 30 cm, the applied magnetic field strength was 0.24 T, and other methods were the same as described above. The organic small molecule electrochemical performance was improved under different magnetic field strengths.

[0097] Example 3:

[0098] A method for improving the electrochemical performance of an organic small molecule by using a magnetic field to affect the gain and loss of electrons of the covalent bond of the molecule, comprising the following steps:

[0099] The organic small molecule TEMPO derivative and the electrolyte were dissolved in water to obtain a TEMPO derivative solution; the concentration of the TEMPO derivative solution was 0.05 mol / L, and the electrolyte was a sodium chloride solution with a concentration of 2 mol / L.

[0100] The TEMPO derivative solution was first subjected to pre-magnetization treatment, and the pre-magnetization treatment method included: the TEMPO derivative solution was added to a flow battery, permanent magnets were arranged around the flow battery, a magnetic field was generated using the permanent magnets, the pump was opened before the battery was powered on, and the TEMPO derivative electrolyte flowed in the magnetic field inside the flow battery, and the pre-magnetization was performed while flowing. The TEMPO derivative solution was subjected to pre-magnetization treatment according to the above method, the applied magnetic field strength of the pre-magnetization treatment was 0.25 T, the pre-magnetization treatment time was 12 h, and the hydrogen bond interaction between the organic small molecule and the water molecule cluster was weakened by the pre-magnetization treatment.

[0101] Then, the subsequent magnetic field treatment was performed according to the method of Example 2, and the remaining steps were the same as those of Example 2.

[0102] Comparative Example 1:

[0103] The difference from Example 1 is that there is no magnetic field around the electrolytic cell, and only the three-electrode cyclic voltammetry scanning of the organic small molecule solution is performed to test its electrochemical performance.

[0104] Comparative Example 2:

[0105] The difference from Example 2 is that there is no magnetic field around the flow battery, and only the battery charging and discharging test of the organic small molecule solution is performed to test its electrochemical performance.

[0106] Performance test:

[0107] As Figure 1As shown, at a scan rate of 100 mV / s, the peak CV of Example 1 is 1.82 times higher than that of Comparative Example 1. Furthermore, while maintaining a high peak current, the spacing between the peak currents in Example 1 of TEMPO molecules also narrowed. This leads to the conclusion that "the reversibility of TEMPO molecules is also improved." This is because the magnetic field in Example 1 affects the overlapping portion of the electron clouds of the covalent bonds in the TEMPO molecules and the directionality of the covalent bonds, i.e., it affects the ability of covalent bonds to gain or lose electrons. Moreover, the energy of the magnetic field can lower the energy level of covalent bond breaking, accelerating the electron transport rate within the TEMPO molecule, thereby lowering the activation energy of the redox reaction and improving the reversibility of the reaction. Therefore, the magnetic field has a significant impact on the electrochemical performance of TEMPO derivatives.

[0108] like Figure 2 As shown, at a scan rate of 100 mV / s, the peak CV of Example 1 is 1.18 times higher than that of Comparative Example 1, and the spacing between peak currents changes less. This leads to the conclusion that "the reversibility of the ferrocene derivative is also improved." This is because the magnetic field in Example 1 affects the overlapping portion of the electron clouds of the covalent bonds in the ferrocene derivative and the directionality of the covalent bonds, i.e., it affects the ability of the covalent bonds to gain or lose electrons. Furthermore, the energy of the magnetic field can lower the energy level of covalent bond breaking, accelerating the electron transport rate within the ferrocene derivative molecule, thereby lowering the activation energy of the redox reaction and improving the reversibility of the reaction. Therefore, the magnetic field has a significant impact on the electrochemical performance of the ferrocene derivative.

[0109] like Figure 3 As shown, at a scan rate of 100 mV / s, the peak CV of Example 1 is 1.07 times higher than that of Comparative Example 1. The magnetic field has a slight effect on the electrochemical performance of viologen derivatives, which can slightly increase their peak CV. At the same time, the spacing between the peak currents of viologen derivatives is also narrowed, and the reversibility is improved. This is because the magnetic field in Example 1 affects the overlapping part of the electron cloud of the covalent bond of viologen derivatives and the directionality of the covalent bond, that is, it affects the ability of covalent bonds to gain or lose electrons. In addition, the energy of the magnetic field can lower the energy level of covalent bond breaking, and the electron transport rate within the viologen derivative molecule is accelerated, thereby lowering the activation energy of the redox reaction and improving the reversibility of the reaction, thus improving the reversibility of viologen derivatives.

[0110] like Figure 4As shown, at a scan rate of 100 mV / s, the peak CV of Example 1 is 1.04 times higher than that of Comparative Example 1. The magnetic field has a slight effect on the electrochemical performance of quinone derivatives, which can slightly increase their peak CV. At the same time, the spacing between the peak currents of quinone derivatives is also narrowed, and the reversibility is improved. This is because the magnetic field in Example 1 affects the overlapping part of the electron cloud of the covalent bond of quinone derivatives and the directionality of the covalent bond, that is, it affects the ability of the covalent bond to gain or lose electrons. In addition, the energy of the magnetic field can lower the energy level of covalent bond breaking, and the electron transport rate in quinone derivatives is accelerated, thereby lowering the activation energy of the redox reaction and improving the reversibility of the reaction, thus improving the reversibility of quinone derivatives.

[0111] like Figures 5-7 As shown, the battery containing TEMPO derivatives in Example 2 of this invention exhibits significantly higher capacity utilization at high current densities than the battery without TEMPO derivatives in Comparative Example 2. Furthermore, the stability of Example 2 is significantly better than that of Comparative Example 2 during long-term cycling. Simultaneously, the overpotential of Example 2 is significantly lower than that of Comparative Example 2 during charge-discharge processes. This is because the magnetic field in Example 2 affects the overlapping portion of the electron clouds of the covalent bonds in the TEMPO derivatives and the directionality of the covalent bonds, thus affecting the ability of covalent bonds to gain or lose electrons. Additionally, the energy of the magnetic field can lower the energy level of covalent bond breaking, thereby lowering the activation energy of the redox reaction, reducing battery activation polarization, and thus improving the capacity utilization of the battery at high current densities, providing battery stability, and reducing the overpotential during charge-discharge processes. Therefore, Example 2 again demonstrates that the magnetic field has a significant impact on the electrochemical performance of TEMPO derivatives.

[0112] like Figures 8-9 As shown, the battery containing ferrocene derivatives in Example 2 of this invention exhibits significantly higher capacity utilization at high current densities than the battery without ferrocene derivatives in Comparative Example 2. During long-cycle operation, the stability of Example 2 is essentially the same as that of Comparative Example 2. This is because the magnetic field in Example 2 affects the overlapping portion of the electron clouds of the covalent bonds in the ferrocene derivatives and the directionality of the covalent bonds, thus affecting the ability of the covalent bonds to gain or lose electrons. Furthermore, the energy of the magnetic field can lower the energy level of covalent bond breaking, thereby lowering the activation energy of the redox reaction, reducing battery activation polarization, and thus improving the capacity utilization of the battery at high current densities, providing battery stability, and reducing overpotential during charge and discharge. Therefore, Example 2 again demonstrates that the magnetic field has a significant impact on the electrochemical performance of ferrocene derivatives.

[0113] In summary, the experimental data above show that magnetic field treatment can improve the electrochemical performance of TEMPO molecules, ferrocene derivatives, viologen derivatives, and quinone derivatives.

[0114] The above merely describes preferred specific embodiments of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art, according to the technical solution and inventive concept of the present application, makes equivalent replacement or change within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. A method for improving the electrochemical performance of small organic molecules, characterized in that, Includes the following steps: A magnetic field generating device is set on both sides of the electrolytic cell. Organic small molecules are added to the electrolytic cell, the electrolytic cell is energized, and the magnetic field generating device is turned on. The magnetic field generated by the magnetic field generating device is applied to the electrolytic cell. The magnetic field reduces the reaction activation energy of the organic small molecules and increases the diffusion rate of the organic small molecules by affecting the ability of the covalent bonds of the organic small molecules to gain or lose electrons. Alternatively, a magnetic field generator can be installed around the flow battery, organic small molecules can be added to the flow battery, the flow battery can be charged and discharged, and the magnetic field generator can be turned on to apply the magnetic field generated by the magnetic field generator to the flow battery. The magnetic field reduces the reaction activation energy of the organic small molecules and increases the diffusion rate of the organic small molecules by affecting the ability of the covalent bonds of the organic small molecules to gain or lose electrons. The organic small molecules are active substances; The organic small molecules include at least one of TEMPO derivatives, ferrocene derivatives, viologen derivatives, quinone derivatives, phenazine derivatives, phenothiazine derivatives, and phenotoxazine derivatives; The magnetic field is continuously applied during the operation of the electrolytic cell or the flow battery; The magnetic field is applied perpendicularly to the working electrode of the electrolytic cell or the bipolar plate of the flow battery; The steps also include: first, placing the organic small molecules into an external magnetic field for pre-magnetization treatment.

2. The method for improving electrochemical performance according to claim 1, characterized in that, The organic small molecules are added to the electrolytic cell or the flow battery in the form of an organic small molecule solution, wherein the organic small molecule solution is prepared in the following manner: The organic small molecules are dissolved in water to obtain the organic small molecule solution; The concentration of the organic small molecules in the solution is 0.05 mmol / L to 4 mmol / L.

3. The method for improving electrochemical performance according to claim 2, characterized in that, The organic small molecule solution also contains electrolytes. When electrolytes are present, the organic small molecule solution is prepared as follows: The organic small molecules and electrolytes are dissolved in water to obtain the organic small molecule solution; The concentration of the electrolyte in the organic small molecule solution is 0.05 mol / L to 3 mol / L.

4. The method for improving electrochemical performance according to claim 1, characterized in that, The strength of the magnetic field ranges from 0.1T to 0.5T.

5. The method for improving electrochemical performance according to claim 1, characterized in that, The electrochemical performance enhancement method further includes: weakening the hydrogen bonding between the organic small molecules and water molecule clusters using an external magnetic field, wherein the pre-magnetization treatment includes the following steps: A magnetic field generator is arranged around the flow battery to generate an external magnetic field. The organic small molecules are added to the flow battery and kept in a flowing state inside the flow battery. Under the action of the external magnetic field, the organic small molecules are pre-magnetized while flowing.

6. The method for improving electrochemical performance according to claim 5, characterized in that, The pre-magnetization intensity ranges from 0.1T to 0.5T, and the pre-magnetization time ranges from 6h to 24h.

7. A flow battery, comprising an electrolyte, characterized in that, The electrolyte contains small organic molecules treated by the electrochemical performance enhancement method according to any one of claims 1 to 6.

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