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

Abstract

The invention discloses a method for improving the electrochemical performance of small organic molecules and a flow battery, and relates to the technical field of organic flow batteries. The electrochemical performance improving method comprises the following steps: arranging magnetic field generating devices on two sides of an electrolytic tank, adding small organic molecules into the electrolytic tank, electrifying the electrolytic tank, starting the magnetic field generating devices, and applying a magnetic field generated by the magnetic field generating devices to the electrolytic tank; or arranging a magnetic field generating device at the periphery of the flow battery, adding the small organic molecules into the flow battery, charging and discharging the flow battery, starting the magnetic field generating device, and applying the magnetic field generated by the magnetic field generating device to the flow battery. The invention also provides a flow battery which comprises electrolyte, and the electrolyte contains the small organic molecules treated by the method. The method has the beneficial effects that the molecular diffusion speed is increased by utilizing the magnetic field to influence the covalent bond of the small organic molecules to gain and lose electrons, so that the electrochemical performance of the small organic molecules is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of organic liquid flow batteries, and in particular to a method for improving the electrochemical performance of organic small molecules and a liquid flow battery. Background Art

[0002] Organic liquid flow batteries (ORFBs) are an energy storage technology that uses water-soluble or water-insoluble organic molecules as active materials, storing and releasing energy through redox reactions. Its core structure includes positive and negative electrolyte storage tanks, a reaction chamber, an ion exchange membrane, and a circulation system. The separation of the electrolyte and the stack allows for independent regulation of energy and power, adapting to large-scale energy storage needs. Based on the type of electrolyte solvent, ORFBs are divided into aqueous and non-aqueous systems. The former uses water as a solvent, offering high safety and low cost; the latter uses organic solvents (such as acetonitrile) as a solvent, offering higher energy density but requiring solutions to volatility and stability issues.

[0003] The core advantage of organic flow batteries lies in their environmental friendliness and sustainability. They completely eliminate metal resources like vanadium and chromium, relying instead on chemically synthesizable organic compounds (such as anthraquinone and bipyridine derivatives). These raw materials are widely available and pose low environmental risks. Furthermore, aqueous ORFBs are inherently safe, with a non-flammable electrolyte that is not susceptible to strong acid or alkaline corrosion. They also offer a wide operating temperature range (some models can operate stably at 60°C), making them suitable for high-temperature environments or those with stringent safety requirements.

[0004] Despite its significant potential, ORFBs still face technical bottlenecks. Existing ORFB technology suffers from poor conductivity of organic small molecules and the complex and variable redox reactions of covalently bonded organic molecules, resulting in low capacity utilization and energy efficiency at high current densities. Therefore, it is urgent to design a method to improve the electrochemical performance of organic small molecules. Summary of the Invention

[0005] The purpose of the present invention is to solve at least one of the technical problems existing in the prior art, and to provide a method for improving the electrochemical performance of organic small molecules and a liquid flow battery. Specifically, it provides a method for using a magnetic field to influence the gain and loss of electrons of molecular covalent bonds to improve the electrochemical performance of organic small molecules, and a liquid flow battery containing the organic small molecules.

[0006] Chinese patent CN 111326779 A discloses a method for improving the transmission performance of a deep eutectic solvent electrolyte flow battery and a flow battery. This patent involves placing the deep eutectic solvent electrolyte flow battery in a magnetic field of 165mT to 605mT. This allows the charged particles in the electrolyte to move faster under the influence of the Lorentz force, thereby increasing the ion movement rate and the conductivity of the flow battery. Chinese patent CN 117558957 A discloses a flow battery system and performance enhancement method for magnetically managing paramagnetic reactive ions. This patent involves causing the electrolyte entering the flow battery to flow through or penetrate a magnetic porous electrode with a gradient magnetic field inside and on its surface, thereby improving the battery's electrical energy efficiency. While these two patents disclose methods for treating electrolytes with magnetic fields, they utilize magnetic fields to influence ionic bonds. Ionic bonds are formed by the electrostatic interaction of atoms to form anions or cations by gaining or losing electrons. The prior art does not disclose methods for using magnetic fields to influence molecular covalent bonds to improve molecular electrochemical performance.

[0007] The present invention provides a method for enhancing the electrochemical properties of small organic molecules by influencing the electron gain or loss of covalent bonds using a magnetic field. Covalent bonds are formed by sharing electron pairs between atoms; there is no electron gain or loss between atoms, and the resulting compound contains no anions or cations. Compared to the aforementioned patent, the present invention differs in that ionic and covalent bonds have different directional characteristics during bonding: ionic bonds are non-directional, while covalent bonds are directional. Because the attractive force distribution of anions and cations is spherically symmetrical, an ion equally attracts an ion of opposite charge in any direction, making ionic bonds non-directional. Covalent bonds, on the other hand, are quite different. Covalent bonds form when the electron clouds of the bonding atoms overlap. The greater the overlap, the greater the electron cloud density between the two nuclei, and the stronger the covalent bond. Therefore, covalent bond formation tends to proceed as closely as possible along the direction of maximum electron cloud density. While the electron clouds of s orbitals are spherically symmetrical and non-directional when overlapping, the electron clouds of the remaining p, d, and f orbitals have specific spatial extension directions, thus exhibiting directional characteristics during bonding. The directionality of covalent bonds determines the spatial arrangement of atoms in a molecule. The symmetry of the atomic arrangement plays a crucial role in determining the polarity of the molecule. The present invention utilizes a magnetic field to influence the overlap of electron clouds and the directionality of covalent bonds. Furthermore, covalent bonds generally have higher bond energies than ionic bonds. The energy of the magnetic field can lower the energy level of covalent bond breaking, reducing the activation energy of redox reactions and thereby improving the reversibility of the reactions.

[0008] The technical solutions of the present invention are as follows: A first aspect of the present invention provides a method for improving the electrochemical performance of organic small molecules, comprising the following steps: Magnetic field generating devices are provided on both sides of an electrolytic cell, small organic molecules are added to the electrolytic cell, the electrolytic cell is energized, and the magnetic field generating devices are turned on to apply a magnetic field generated by the magnetic field generating devices to the electrolytic cell, whereby the magnetic field reduces the reaction activation energy of the small organic molecules and increases the diffusion rate of the small organic molecules by affecting the ability of the covalent bonds of the small organic molecules to gain or lose electrons; Alternatively, a magnetic field generating device is arranged around the liquid flow battery, small organic molecules are added to the liquid flow battery, the liquid flow battery is charged and discharged, and the magnetic field generating device is turned on to apply the magnetic field generated by the magnetic field generating device to the liquid 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.

[0009] Preferably, the organic small molecule includes at least one of TEMPO derivatives, ferrocene derivatives, viologen derivatives, quinone derivatives, phenazine derivatives, phenothiazine derivatives, and phenoxazine derivatives.

[0010] Preferably, the organic small molecule is 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: dissolving the organic small molecule in water to obtain the organic small molecule solution; In the organic small molecule solution, the concentration of the organic small molecule is 0.05 mmol / L to 4 mmol / L.

[0011] Preferably, the organic small molecule solution further contains an electrolyte. When the organic small molecule solution contains an electrolyte, the organic small molecule solution is prepared as follows: dissolving an organic small molecule and an electrolyte in water to obtain the organic small molecule solution; In the organic small molecule solution, the concentration of the electrolyte is 0.05 mol / L to 3 mol / L.

[0012] Preferably, the intensity of the magnetic field is in the range of 0.1T-0.5T.

[0013] Preferably, the magnetic field is continuously applied during operation of the battery.

[0014] Preferably, the magnetic field is applied perpendicularly to the electrodes of the electrolytic cell or the bipolar plates of the flow battery.

[0015] Preferably, the electrochemical performance improvement method further comprises: first placing the organic small molecule in an external magnetic field for pre-magnetization treatment, thereby weakening the hydrogen bonding between the organic small molecule and the water molecule clusters by the external magnetic field, wherein the pre-magnetization treatment comprises the following steps: A magnetic field generating device is arranged around the liquid flow battery to generate an external magnetic field, the organic small molecules are added into the liquid flow battery and kept in a flowing state inside the liquid flow battery. Under the action of the external magnetic field, the organic small molecules are pre-magnetized while flowing.

[0016] Preferably, the pre-magnetization treatment intensity ranges from 0.1T to 0.5T, and the pre-magnetization treatment time ranges from 6h to 24h.

[0017] A second aspect of the present invention provides a flow battery comprising an electrolyte containing organic small molecules treated by the method described above.

[0018] The present invention has at least one of the following beneficial effects: The present invention sets a magnetic field generating device near an organic small molecule solution and applies a magnetic field to the organic small molecule solution, thereby utilizing magnetic force to influence the covalent bond of the organic small molecule to gain or lose electrons, thereby reducing the reaction activation energy of the organic small molecule and increasing the diffusion rate of the organic small molecule, thereby improving the electrochemical performance of the organic small molecule. Then, the electrolyte entering the flow battery flows through the battery with a magnetic field, and the organic small molecules in the electrolyte will increase the molecular diffusion rate under the action of the magnetic force, thereby improving the battery performance. The technical problems solved by the present invention include the low battery capacity utilization and energy efficiency in existing organic liquid flow battery technology, and achieve the purpose of improving the battery capacity utilization and energy efficiency without changing other components of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of CV curves of TEMPO derivatives in the presence of a magnetic field in Example 1 and in the absence of a magnetic field in Comparative Example 1; Figure 2 Schematic diagram of CV curves of ferrocene derivatives in the presence of a magnetic field in Example 1 and in the absence of a magnetic field in Comparative Example 1; Figure 3 Schematic diagram of CV curves of the viologen derivative in the presence of a magnetic field in Example 1 and in the absence of a magnetic field in Comparative Example 1; Figure 4 Schematic diagram of CV curves of quinone derivatives in the presence of a magnetic field in Example 1 and in the absence of a magnetic field in Comparative Example 1; Figure 5 Schematic diagram of the battery rate performance of TEMPO derivatives in the presence of a magnetic field in Example 2 and in the absence of a magnetic field in Comparative Example 2; Figure 6 Schematic diagram of the long-cycle performance of the battery of TEMPO derivatives in the presence of a magnetic field in Example 2 and in the absence of a magnetic field in Comparative Example 2; Figure 7Schematic diagram of the battery voltage of the TEMPO derivative in the presence of a magnetic field in Example 2 and in the absence of a magnetic field in Comparative Example 2; Figure 8 Schematic diagram of the battery rate performance of the ferrocene derivative in the presence of a magnetic field in Example 2 and in the absence of a magnetic field in Comparative Example 2; Figure 9 Schematic diagram of the long cycle performance of the battery of ferrocene derivatives in the presence of a magnetic field in Example 2 and in the absence of a magnetic field in Comparative Example 2. DETAILED DESCRIPTION

[0020] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0021] One embodiment of the present invention provides a method for improving the electrochemical performance of organic small molecules, comprising the following steps: Magnetic field generating devices are provided on both sides of the electrolytic cell, small organic molecules are added to the electrolytic cell, the electrolytic cell is energized, and the magnetic field generating devices are turned on to apply the magnetic field generated by the magnetic field generating devices to the electrolytic cell. The magnetic field increases the molecular diffusion rate by affecting the covalent bond gain or loss of electrons of the small organic molecules; Alternatively, a magnetic field generating device is arranged around the liquid flow battery, small organic molecules are added to the liquid flow battery, the liquid flow battery is charged and discharged, and the magnetic field generating device is turned on to apply the magnetic field generated by the magnetic field generating device to the liquid flow battery. The magnetic field increases the molecular diffusion rate by affecting the covalent bonds of the small organic molecules to gain or lose electrons.

[0022] This invention applies a magnetic field near small organic molecules, leveraging the magnetic field to influence the gain or loss of electrons in their covalent bonds, thereby increasing their diffusion coefficient and thus enhancing their electrochemical performance. This invention addresses the low capacity utilization and energy efficiency of existing organic flow batteries, achieving these improvements without changing other battery components.

[0023] 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.

[0024] Specifically, the structural formulas of TEMPO derivatives, ferrocene derivatives, viologen derivatives, quinone derivatives, phenazine derivatives, phenothiazine derivatives, and phenoxazine derivatives are as follows: Viologen derivatives: ; TEMPO derivatives: ; Ferrocene derivatives: ; Quinone derivatives: ; Phenazine derivatives: ; Phenothiazine derivatives: ; Phenoxazine derivatives: ; 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: dissolving the organic small molecule in water to obtain the organic small molecule solution; In the organic small molecule solution, the concentration of the organic small molecule is 0.05 mmol / L to 4 mmol / L.

[0025] 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, and specifically may 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.

[0026] In some embodiments, the organic small molecule solution further contains an electrolyte. When the solution contains an electrolyte, the preparation method of the organic small molecule solution includes: dissolving an organic small molecule and an electrolyte in water to obtain the organic small molecule solution; In the organic small molecule solution, the concentration of the electrolyte is 0.05 mol / L to 4 mol / L; The electrolyte includes sodium chloride.

[0027] 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.

[0028] Specifically, TEMPO derivatives are dissolved in a solution, which generally also contains a supporting electrolyte. The magnetic field improves the electrochemical properties of TEMPO derivatives by affecting the gain and loss of electrons on the nitrogen-oxygen covalent bond of the TEMPO derivatives.

[0029] Specifically, the ferrocene derivative is dissolved in a solution, which generally also contains a supporting electrolyte. The ferrocene derivative's iron-carbon covalent bond gains or loses electrons, thereby enhancing the electrochemical performance of the ferrocene derivative.

[0030] Specifically, the viologen derivative is dissolved in a solution, which typically also contains a supporting electrolyte. The nitrogen-carbon covalent bond of the viologen derivative gains or loses electrons, thereby enhancing the electrochemical performance of the viologen derivative.

[0031] Specifically, quinone derivatives are dissolved in a solution, which typically also contains a supporting electrolyte. The nitrogen and oxygen covalent bonds of the quinone derivatives gain or lose electrons, thereby enhancing the electrochemical performance of the quinone derivatives.

[0032] Specifically, the phenazine derivative is dissolved in a solution, which generally also contains a supporting electrolyte. The nitrogen-carbon covalent bond of the phenazine derivative gains or loses electrons, thereby improving the electrochemical performance of the phenazine derivative.

[0033] Specifically, the phenothiazine derivative is dissolved in a solution, which generally also contains a supporting electrolyte. The nitrogen-carbon covalent bond of the phenothiazine derivative gains or loses electrons, thereby improving the electrochemical performance of the phenothiazine derivative.

[0034] Specifically, the phenoxazine derivative is dissolved in a solution, which generally also contains a supporting electrolyte. The nitrogen-carbon covalent bond of the phenoxazine derivative gains or loses electrons, thereby improving the electrochemical performance of the phenoxazine derivative.

[0035] In some embodiments, the magnetic field strength ranges from 0.1T to 0.5T, preferably from 0.2T to 0.31T.

[0036] In some embodiments, the magnetic field is applied continuously during operation of the battery.

[0037] In some embodiments, the magnetic field is applied perpendicularly to the electrodes of the electrolytic cell or the bipolar plates of the flow battery.

[0038] In some embodiments, the organic small molecule is further subjected to a pre-magnetization treatment before being added to the electrolytic cell or the flow battery, and the pre-magnetization treatment method includes: The organic small molecules are placed in an external magnetic field for pre-magnetization treatment, and the external magnetic field weakens the hydrogen bonding between the organic small molecules and the water molecule clusters.

[0039] The pre-magnetization process specifically includes the following steps: A magnetic field generating device is arranged around the liquid flow battery to generate an external magnetic field, the organic small molecules are added into the liquid flow battery and kept in a flowing state inside the liquid flow battery. Under the action of the external magnetic field, the organic small molecules are pre-magnetized while flowing.

[0040] In some embodiments, the intensity of the pre-magnetization treatment ranges from 0.1 T to 0.5 T, preferably from 0.2 T to 0.31 T. The pre-magnetization treatment time ranges from 6 h to 24 h, preferably from 12 h to 24 h.

[0041] In some embodiments, the magnetic field generating device includes a permanent magnet or an electromagnet, that is, the magnetic field can be generated by arranging a magnetic field generator such as a permanent magnet or an electromagnet.

[0042] The principle of the present invention includes: by arranging a magnetic field generating device on both sides of the electrolytic cell or around the liquid flow battery, the magnetic field generated by the magnetic field generating device will orient the direction of the electron spin on the covalent bond of the organic small molecule. According to the principles of quantum mechanics, the spin of the electron can only exist along a specific direction (up spin and down spin), rather than rotating in any direction. When a magnetic field exists, it will exert a force on the spin of the electron, causing the spin to tend to the same or opposite direction as the magnetic field. This force is called a spin field. The direction of the electron spin on the covalent bond of the organic small molecule is changed from disordered to directional, thereby increasing the stability of the molecule.

[0043] Furthermore, magnetic fields affect the energy levels of electron spins. According to the principles of quantum mechanics, electron spin and orbital motion are closely linked, and together they determine the electron's energy level structure. When an electron is exposed to a magnetic field, the field couples the electron's spin and orbital motion, thereby changing the electron's energy level. This phenomenon is known as spin-orbit coupling. Under the influence of a magnetic field, the energy range for electron gain and loss in covalent bonds of small organic molecules narrows, reducing the energy required for gaining or losing electrons, thereby reducing overpotential and improving electrochemical performance.

[0044] The influence of magnetic force includes the influence of Lorentz force and Kelvin force on small organic molecules, among which, (1) The influence of the Lorentz force on small organic molecules can be obtained from the following formula: in, F L is the Lorentz force, q and E represent the charge and electric field strength respectively, v represents the speed of charged particles, and B is the magnetic field strength.

[0045] (2) The influence of Kelvin force on small organic molecules can be obtained from the following formula: in, F K It's the Kelvin force. is the magnetic constant in free space, c represents the concentration of paramagnetic organic small molecules, is the molar magnetic susceptibility, is the magnetic field gradient.

[0046] Another embodiment of the present invention provides a flow battery, comprising an electrolyte, wherein the electrolyte contains organic small molecules obtained after treatment by the method described above.

[0047] The present invention treats organic small molecules through a magnetic field and adds the organic small molecules to the electrolyte without changing the liquid flow battery and its components, thereby improving the battery capacity utilization and energy efficiency.

[0048] In some embodiments, the flow battery is mainly composed of an infusion pump, a storage tank, a fuel cell stack and other pipelines, and the fuel cell stack is mainly assembled from a current collector, a bipolar plate, an electrode, and a diaphragm.

[0049] The present invention is further described in detail below with reference to specific examples, but the present invention is not limited to the following specific examples.

[0050] Example 1: A method for improving the electrochemical performance of organic small molecules by using a magnetic field to influence the gain or loss of electrons in molecular covalent bonds comprises the following steps: An organic small molecule TEMPO derivative and an electrolyte are dissolved in water to obtain a TEMPO derivative solution; the concentration of the TEMPO derivative solution is 2 mmol / L, the electrolyte is a sodium chloride solution, and the concentration of the sodium chloride solution is 2 mol / L.

[0051] A TEMPO derivative solution was added to an electrolytic cell, with magnetic field generators positioned on both sides of the cell. The electrochemical properties of the TEMPO derivative solution were tested using three-electrode cyclic voltammetry, with carbon felt as the working electrode, platinum wire as the auxiliary electrode, and silver chloride as the reference electrode, at a constant scan rate of 100 mV / s. In this example, a permanent magnet with a strength of N35 (maximum magnetic energy product of approximately 35 MGOe) was used to generate the magnetic field, separated by a distance of 30 cm. The magnetic field was applied perpendicularly to the surface of the carbon felt working electrode at a magnetic field strength of 0.21 T, and the magnetic field treatment lasted for 1 hour.

[0052] The “TEMPO derivative” was replaced by a ferrocene derivative, a viologen derivative, and a quinone derivative, and the ferrocene derivative, the viologen derivative, and the quinone derivative were treated with a magnetic field using the same method as above.

[0053] Example 2: A method for improving the electrochemical performance of organic small molecules by using a magnetic field to influence the gain or loss of electrons in molecular covalent bonds comprises the following steps: An organic small molecule TEMPO derivative and an electrolyte are dissolved in water to obtain a TEMPO derivative electrolyte; the concentration of the TEMPO derivative electrolyte is 0.05 mol / L, the electrolyte is a sodium chloride solution, and the concentration of the sodium chloride solution is 2 mol / L.

[0054] A magnetic field perpendicular to the bipolar plates of the battery is arranged around the liquid flow battery, so that the TEMPO derivative electrolyte flows into the liquid flow battery, and the charge and discharge test is performed on it. The liquid flow battery is mainly composed of an infusion pump, a storage tank, a stack and other pipelines. The stack is mainly assembled by a current collector, a bipolar plate, an electrode, and a diaphragm. This embodiment uses a permanent magnet to generate a magnetic field. The permanent magnet strength is N52 (the maximum magnetic energy product is about 52MGOe), the spacing is 30cm, the applied magnetic field strength is 0.26T, and the magnetic field treatment time is 1h. The test is divided into a rate performance test and a long cycle performance test. The rate performance test is at 20 mA cm -2 -160 mA cm -2 The long cycle was tested at 80 mA cm -2 Test it below.

[0055] The TEMPO derivative was replaced with a ferrocene derivative, with a permanent magnet strength of N45 (maximum magnetic energy product of approximately 45 MGOe), a spacing of 30 cm, and an applied magnetic field strength of 0.24 T. The ferrocene derivative was treated with the same magnetic field method as above. The electrochemical performance of the organic small molecule was improved at various magnetic field strengths.

[0056] Example 3: A method for improving the electrochemical performance of organic small molecules by using a magnetic field to influence the gain or loss of electrons in molecular covalent bonds comprises the following steps: An organic small molecule TEMPO derivative and an electrolyte are dissolved in water to obtain a TEMPO derivative solution; the concentration of the TEMPO derivative solution is 0.05 mol / L, and the electrolyte is a sodium chloride solution, and the concentration of the sodium chloride solution is 2 mol / L.

[0057] The TEMPO derivative solution was pre-magnetized. The pre-magnetization method includes adding the TEMPO derivative solution to a flow battery, placing permanent magnets around the flow battery to generate a magnetic field, and turning on a pump before energizing the battery to allow the TEMPO derivative electrolyte to flow within the flow battery under the magnetic field, pre-magnetizing the solution as it flows. The TEMPO derivative solution was pre-magnetized using the above method at a magnetic field intensity of 0.25 T for 12 hours. The pre-magnetization weakens the hydrogen bonding between the organic small molecules and the water molecule clusters.

[0058] Then, the subsequent magnetic field treatment is performed according to the method of Example 2, and the remaining steps are the same as Example 2.

[0059] Comparative Example 1: The difference from Example 1 is that there is no magnetic field around the electrolytic cell, and only three-electrode cyclic voltammetry scanning is performed on the organic small molecule solution to test its electrochemical performance.

[0060] Comparative Example 2: The difference from Example 2 is that there is no magnetic field around the flow battery, and only battery charge and discharge tests are performed on the organic small molecule solution to test its electrochemical performance.

[0061] Performance testing: like Figure 1 As shown, at a scan rate of 100 mv / s, the CV peak value of Example 1 is 1.82 times higher than that of Comparative Example 1. Furthermore, while maintaining a high peak current, the spacing between peak currents in the TEMPO molecule of Example 1 also narrows. This leads to the conclusion that "the reversibility of the TEMPO molecule is also improved." This is because the magnetic field in Example 1 affects the electron cloud overlap and directionality of the covalent bonds of the TEMPO molecule, that is, the ability of the covalent bonds to gain or lose electrons. Furthermore, the energy of the magnetic field can lower the energy level of the covalent bond breaking, accelerating the electron transfer rate within the TEMPO molecule, thereby reducing the activation energy of the redox reaction and increasing the reversibility of the reaction, thereby improving the reversibility of the TEMPO molecule. Therefore, the magnetic field has a significant effect on the electrochemical properties of TEMPO derivatives.

[0062] like Figure 2 As shown, at a sweep rate of 100 mv / s, the CV peak value of Example 1 is 1.18 times higher than that of Comparative Example 1, and the spacing between the peak currents changes little. From this, it can be concluded that "the reversibility of the ferrocene derivatives has also been improved". This is because the magnetic field in Example 1 affects the overlapping part of the electron cloud of the covalent bond of the ferrocene derivative and the directionality of the covalent bond, that is, it affects the ability of the covalent bond to gain or lose electrons, and the energy of the magnetic field can reduce the energy level of the covalent bond breaking, accelerate the electron transfer rate in the ferrocene derivative molecule, thereby reducing the activation energy of the redox reaction and improving the reversibility of the reaction, thereby improving the reversibility of the ferrocene derivative. Therefore, the effect of the magnetic field on the electrochemical properties of the ferrocene derivative is more obvious.

[0063] like Figure 3As shown, at a scan rate of 100 mv / s, the CV peak value of Example 1 is 1.07 times higher than that of Comparative Example 1. The magnetic field has a slight effect on the electrochemical properties of the viologen derivatives, and can slightly increase their CV peak value. At the same time, the interval between the peak currents of the 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 the viologen derivative and the directionality of the covalent bond, that is, it affects the ability of the covalent bond to gain or lose electrons, and the energy of the magnetic field can reduce the energy level of the covalent bond breaking, and the electron transmission rate in the viologen derivative molecule is accelerated, thereby reducing the activation energy of the redox reaction and improving the reversibility of the reaction, thereby improving the reversibility of the viologen derivative.

[0064] like Figure 4 As shown, at a scan rate of 100 mv / s, the CV peak value of Example 1 is 1.04 times higher than that of Comparative Example 1. The magnetic field has a slight effect on the electrochemical properties of the quinone derivatives, and can slightly increase their CV peak value. At the same time, the interval between the peak currents of the 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 the quinone derivative and the directionality of the covalent bond, that is, it affects the ability of the covalent bond to gain or lose electrons, and the energy of the magnetic field can reduce the energy level of the covalent bond breaking, and the electron transmission rate in the quinone derivative is accelerated, thereby reducing the activation energy of the redox reaction and improving the reversibility of the reaction, thereby improving the reversibility of the quinone derivative.

[0065] like Figures 5 to 7 As shown, the battery containing a TEMPO derivative in Example 2 of the present invention exhibits significantly higher capacity utilization at high current density than the battery without a TEMPO derivative in Comparative Example 2. The stability of Example 2 is also significantly better than that of Comparative Example 2 during long cycles. Furthermore, the overpotential of Example 2 during charge and discharge is significantly lower than that of Comparative Example 2. This is because the magnetic field in Example 2 affects the electron cloud overlap and directionality of the covalent bonds of the TEMPO derivative, i.e., the ability of the covalent bonds to gain or lose electrons. Furthermore, the energy of the magnetic field can lower the energy level of the covalent bond breaking, thereby reducing the activation energy of the redox reaction and reducing the battery activation polarization. This improves the battery's capacity utilization at high current density, improves battery stability, and reduces the overpotential during charge and discharge. Therefore, Example 2 once again demonstrates the significant effect of the magnetic field on the electrochemical properties of TEMPO derivatives.

[0066] like Figures 8 and 9As shown, the battery containing ferrocene derivatives in Example 2 of the present invention has a significantly higher battery capacity utilization rate at high current density than the battery in Comparative Example 2 that does not contain ferrocene derivatives. The stability of Example 2 in long cycles is basically the same as that of Comparative Example 2. This is because the magnetic field in Example 2 affects the electron cloud overlap of the covalent bond of the ferrocene derivative 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 reduce the energy level of the covalent bond breaking, thereby reducing the activation energy of the redox reaction and reducing the battery activation polarization, thereby improving the battery capacity utilization rate at high current density, improving the battery stability, and reducing the overpotential during the charge and discharge process. Therefore, Example 2 once again proves that the magnetic field has a significant effect on the electrochemical properties of ferrocene derivatives.

[0067] In summary, it can be seen from the above experimental data that the electrochemical properties of TEMPO molecules, ferrocene derivatives, viologen derivatives and quinone derivatives can be improved by magnetic field treatment.

[0068] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A method for improving the electrochemical performance of organic small molecules, characterized in that: The following steps are involved: Magnetic field generating devices are provided on both sides of an electrolytic cell, small organic molecules are added to the electrolytic cell, the electrolytic cell is energized, and the magnetic field generating devices are turned on to apply a magnetic field generated by the magnetic field generating devices to the electrolytic cell, whereby the magnetic field reduces the reaction activation energy of the small organic molecules and increases the diffusion rate of the small organic molecules by affecting the ability of the covalent bonds of the small organic molecules to gain or lose electrons; Alternatively, a magnetic field generating device is arranged around the liquid flow battery, small organic molecules are added to the liquid flow battery, the liquid flow battery is charged and discharged, and the magnetic field generating device is turned on to apply the magnetic field generated by the magnetic field generating device to the liquid 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.

2. The electrochemical performance improvement method according to claim 1, characterized in that: The organic small molecule includes at least one of TEMPO derivatives, ferrocene derivatives, viologen derivatives, quinone derivatives, phenazine derivatives, phenothiazine derivatives, and phenoxazine derivatives.

3. The electrochemical performance improvement method according to claim 1, characterized in that: The organic small molecule is 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: dissolving the organic small molecule in water to obtain the organic small molecule solution; In the organic small molecule solution, the concentration of the organic small molecule is 0.05 mmol / L to 4 mmol / L.

4. The electrochemical performance improvement method according to claim 3, characterized in that: The organic small molecule solution further contains an electrolyte. When the electrolyte is contained, the organic small molecule solution is prepared in the following manner: dissolving an organic small molecule and an electrolyte in water to obtain the organic small molecule solution; In the organic small molecule solution, the concentration of the electrolyte is 0.05 mol / L to 3 mol / L.

5. The electrochemical performance improvement method according to claim 1, characterized in that: The intensity of the magnetic field ranges from 0.1T to 0.5T.

6. The electrochemical performance improvement method according to claim 1, characterized in that: The magnetic field is continuously applied during operation of the electrolytic cell or the flow battery.

7. The electrochemical performance improvement method according to claim 1, characterized in that: The magnetic field is applied perpendicularly to the working electrode of the electrolytic cell or the bipolar plate of the flow battery.

8. The electrochemical performance improvement method according to claim 1, characterized in that: The electrochemical performance improvement method further includes: first placing the organic small molecule in an external magnetic field for pre-magnetization treatment, thereby weakening the hydrogen bonding between the organic small molecule and the water molecule clusters by the external magnetic field, wherein the pre-magnetization treatment includes the following steps: A magnetic field generating device is arranged around the liquid flow battery to generate an external magnetic field, the organic small molecules are added into the liquid flow battery and kept in a flowing state inside the liquid flow battery. Under the action of the external magnetic field, the organic small molecules are pre-magnetized while flowing.

9. The electrochemical performance improvement method according to claim 8, characterized in that: The pre-magnetization treatment intensity ranges from 0.1T to 0.5T, and the pre-magnetization treatment time ranges from 6h to 24h.

10. A flow battery comprising an electrolyte, characterized in that: The electrolyte contains organic small molecules treated by the electrochemical performance improvement method according to any one of claims 1 to 9.

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