阅读说明：本技术 一种儿茶酚类正极电解液及其在液流电池中的应用 (Catechol positive electrode electrolyte and application thereof in flow battery ) 是由 李享容 唐奡 严川伟 于 2019-09-03 设计创作，主要内容包括：本发明涉及液流电池领域,具体为一种使用儿茶酚及其衍生物作为活性物质的电解液及其在液流电池中的应用。正极电解液由正极活性物质和支持电解液组成,正极活性物质为儿茶酚或其衍生物,支持电解液为酸性水溶液。正极活性物质包括儿茶酚、多巴胺、肾上腺素、异丙肾上腺素、去氧肾上腺素及其盐中的一种或两种以上。支持电解液的电解质包括硫酸、盐酸、硝酸、磷酸等强酸中的一种或两种以上。本发明中提到的儿茶酚类正极电解液及其液流电池具有电化学活性好、无毒,不含任何稀有元素的优势,电池容量高、安全可靠,价格和资源优势明显。(The invention relates to the field of flow batteries, in particular to an electrolyte using catechol and derivatives thereof as active substances and application thereof in a flow battery. The positive electrode electrolyte consists of a positive electrode active material and a supporting electrolyte, wherein the positive electrode active material is catechol or a derivative thereof, and the supporting electrolyte is an acidic aqueous solution. The positive electrode active material comprises one or more of catechol, dopamine, epinephrine, isoproterenol, phenylephrine and salts thereof. The electrolyte for supporting the electrolyte comprises one or more than two of strong acids such as sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid and the like. The catechol positive electrolyte and the flow battery thereof have the advantages of good electrochemical activity, no toxicity, no rare elements, high battery capacity, safety, reliability, obvious price and resource advantages.)

1. The catechol-based positive electrode electrolyte is characterized by comprising a positive electrode active material and a supporting electrolyte, wherein the positive electrode active material is catechol or a derivative thereof, and the supporting electrolyte is an acidic aqueous solution.

2. The catechol-based positive electrode electrolyte of claim 1, wherein the positive electrode active material comprises one or more of catechol, dopamine, epinephrine, isoproterenol, phenylephrine, and salts thereof.

3. The catecholic acid positive electrode electrolyte according to claim 1, wherein the electrolyte supporting the electrolyte comprises one or more of sulfuric acid, hydrochloric acid, nitric acid, and phosphoric acid.

4. The catechol-based positive electrode electrolyte solution according to claim 1, wherein the total concentration of the positive electrode active material is 0.01 to 2mol L^-1。

5. The catechol-based positive electrode electrolyte solution according to claim 1, wherein the total concentration of the supporting electrolyte solution is 0.1 to 6mol L^-1。

6. The catechol-based positive electrode electrolyte solution as set forth in claim 1, wherein the supporting electrolyte solution is selected from one or more kinds of electrolyte solutions based on the positive electrode active material, the supporting electrolyte solution having high solubility and forming a uniform solution.

7. use of a catechol-based positive electrode electrolyte according to any one of claims 1 to 6 in a flow battery, wherein an acidic solution of catechol or a derivative thereof is used as the positive electrode electrolyte, and oxygen in the positive electrode electrolyte is removed by an inert gas.

8. The use of a catechol-based positive electrolyte solution in a flow battery according to claim 7, wherein the flow battery comprises a positive liquid storage tank, a negative liquid storage tank, a membrane, a first electrode, a pump, a second electrode, a first current collector and a second current collector, wherein the bottom of the positive liquid storage tank is connected with the bottom of the first electrode through a pipeline, the top of the positive liquid storage tank is connected with the top of the first electrode through a pipeline, and the outer side of the first electrode is in close contact with the first current collector to form the positive electrode of the flow battery; the bottom of the negative liquid storage tank is connected with the bottom of the second electrode through a pipeline, the top of the negative liquid storage tank is connected with the top of the second electrode through a pipeline, and the outer side of the second electrode is in close contact connection with the second current collector to form the negative electrode of the flow battery; a diaphragm is arranged between the positive electrode of the flow battery and the negative electrode of the flow battery, the inner sides of the first electrode and the second electrode are respectively in close contact connection with the two sides of the diaphragm, catechol type positive electrolyte is filled in a positive liquid storage tank, and negative electrolyte is filled in a negative liquid storage tank.

9. The application of the catechol-based positive electrolyte in a flow battery according to claim 8, wherein positive and negative electrodes of the flow battery are made of porous carbon felt, graphite felt or carbon cloth, positive and negative current collectors of the flow battery are made of a composite material of a copper plate and a graphite plate, and a diaphragm of the flow battery is an ion exchange membrane.

Technical Field

The invention relates to the field of flow batteries, in particular to an electrolyte using catechol and derivatives thereof as active substances and application thereof in a flow battery.

Background

The rapid increase in fossil resource consumption and demand has restricted human survival and development. The application of renewable resources such as wind energy, solar energy and the like can effectively reduce the dependence on fossil energy and environmental pollution. But the volatility and instability of renewable resources restrict the wide application thereof. The high-efficiency energy storage technology matched with the energy storage device can further promote the market development of renewable resources and ensure the national strategic energy safety. Among the energy storage technologies, the flow battery has the advantages of safety and high efficiency, and has become one of the first choices for large-scale energy storage. At present, the mature redox flow battery is mainly an all-vanadium redox flow battery, but vanadium is expensive and limited in resources, so that the wider application of the vanadium redox flow battery is restricted. Therefore, the development of a novel electrolyte system which is nontoxic and low in cost is imperative.

Disclosure of Invention

In order to overcome the defects of the traditional flow battery, the invention aims to provide the catechol-type flow battery positive electrode electrolyte and construct a novel catechol-type flow battery with high energy density, safe and reliable performance and low cost on the basis of the catechol-type flow battery positive electrode electrolyte.

In view of the above, the technical solution of the present invention is:

A catechol-type positive electrode electrolyte comprises positive electrode active material and supporting electrolyte, wherein the positive electrode active material is catechol or its derivatives, and the supporting electrolyte is acidic aqueous solution.

The catechol positive electrode electrolyte comprises positive active substances including one or more than two of catechol, dopamine, epinephrine, isoproterenol, phenylephrine and salts thereof.

The catechol-based positive electrode electrolyte comprises electrolyte supporting the electrolyte, wherein the electrolyte supporting the electrolyte comprises one or more than two of sulfuric acid, hydrochloric acid, nitric acid and phosphoric acid.

The total concentration of the catechol positive electrode electrolyte is 0.01-2 mol L^-1。

The total concentration of the catechol positive electrolyte is 0.1-6 mol L^-1。

The catechol-based positive electrode electrolyte is selected according to positive active materials, and one or more than two electrolytes are selected for use based on the fact that the solubility is high and a uniform solution is formed.

The catechol-based positive electrolyte is applied to a flow battery, an acidic solution of catechol or a derivative of the catechol is used as the positive electrolyte, and oxygen in the positive electrolyte is removed by inert gas.

the application of the catechol positive electrolyte in the flow battery comprises a positive liquid storage tank, a negative liquid storage tank, a diaphragm, a first electrode, a pump, a second electrode, a first current collector and a second current collector, wherein the bottom of the positive liquid storage tank is connected with the bottom of the first electrode through a pipeline, the top of the positive liquid storage tank is connected with the top of the first electrode through a pipeline, and the outer side of the first electrode is tightly contacted and connected with the first current collector to form the positive electrode of the flow battery; the bottom of the negative liquid storage tank is connected with the bottom of the second electrode through a pipeline, the top of the negative liquid storage tank is connected with the top of the second electrode through a pipeline, and the outer side of the second electrode is in close contact connection with the second current collector to form the negative electrode of the flow battery; a diaphragm is arranged between the positive electrode of the flow battery and the negative electrode of the flow battery, the inner sides of the first electrode and the second electrode are respectively in close contact connection with the two sides of the diaphragm, catechol type positive electrolyte is filled in a positive liquid storage tank, and negative electrolyte is filled in a negative liquid storage tank.

the application of the catechol positive electrolyte in the flow battery is characterized in that the positive electrode and the negative electrode of the flow battery are made of porous carbon felt, graphite felt or carbon cloth, the positive current collector and the negative current collector of the flow battery are made of a composite material of a copper plate and a graphite plate, and the diaphragm of the flow battery is an ion exchange membrane.

The design idea of the invention is as follows:

Aiming at the defects of high cost, resource limitation, low energy density and the like of the traditional flow battery, the invention provides a novel catechol positive electrolyte and application thereof in the flow battery. The catechol positive electrolyte provided by the invention does not contain any metal element, and has the advantages of low cost, no toxicity and no pollution. Meanwhile, the catechol positive electrolyte has good electrochemical activity and electrochemical stability. The catechol active substance can generate a two-electron transfer process in the acidic supporting electrolyte; meanwhile, compared with other organic active substances, the catechol has higher solubility in an aqueous solution, and the capacity of the electrolyte is improved under the combined action of the catechol and the organic active substances. In addition, the catechol-based positive electrolyte has a high oxidation-reduction potential, so that the application of the catechol-based positive electrolyte in a flow battery can improve the battery voltage. The two electron processes and the higher solubility and potential further improve the energy density of the catechol-type flow battery under the synergistic effect of the three processes.

The invention has the advantages and beneficial effects that:

1. The catechol positive electrolyte and the flow battery thereof provided by the invention have the advantages of low cost, no toxicity, no pollution, no metal ions and high voltage.

2. The catechol positive electrolyte and the flow battery thereof have the advantages of good electrochemical activity, no toxicity, no rare elements, high battery capacity, safety, reliability, obvious price and resource advantages.

Drawings

Fig. 1 is a schematic diagram of the operation of dopamine as a positive electrolyte according to an embodiment of the present invention. Wherein the content of the first and second substances, vs SHE indicates that the redox potential of the dopamine positive electrode electrolyte is 0.78V relative to the standard hydrogen electrode potential.

Fig. 2 is a schematic view of the linkage of the catechol-based flow battery of the present invention. In the figure, 1 a positive pole liquid storage tank; 2 a negative pole liquid storage tank; 3, a diaphragm; 4, a first electrode; 5, a second electrode; 6, collecting a first current body; 7, collecting a second current body; 8, pumping one; and 9, a second pump.

Fig. 3 is a cyclic voltammogram of a dopamine positive electrolyte at room temperature according to one embodiment of the present invention. In the figure, the abscissa Potential represents the voltage V (relative to the saturated calomel electrode) and the ordinate Current represents the Current (10)^-4A)。

Fig. 4 is a graph of cycling efficiency of a dopamine/vanadium flow battery according to one embodiment of the invention. In the figure, the abscissa Cycle number represents the number of cycles, and the ordinate Efficiency represents the Efficiency (%).

Fig. 5 is a charge-discharge curve of a dopamine/vanadium flow battery according to one embodiment of the invention. In the figure, the ordinate Cell potential represents the battery voltage (V).

Fig. 6 is a graph of cycling efficiency for different current densities for a dopamine/vanadium flow battery according to one embodiment of the invention. In the figure, the abscissa Cycle number represents the number of cycles, and the ordinate Efficiency represents the Efficiency (%).

Detailed Description

In a specific embodiment, the operating principle of the electrolyte according to an embodiment of the present invention is shown in fig. 1. The working principle diagram of the novel catechol-based flow battery constructed on the basis of the electrolyte according to one embodiment of the invention is shown in fig. 2, and the electrolyte and the battery performance are shown in fig. 3 to 6.

As shown in fig. 2, the operating principle of the novel catechol-based flow battery according to one embodiment of the present invention, which is constructed based on the electrolyte, is as follows:

The bottom of the positive liquid storage tank 1 is connected with the bottom of the electrode I4 through a pipeline (a pump I8 is arranged on the pipeline), the top of the positive liquid storage tank 1 is connected with the top of the electrode I4 through a pipeline, and the outer side of the electrode I4 is in close contact connection with the current collector I6 to form the positive electrode of the flow battery. The bottom of the negative liquid storage tank 2 is connected with the bottom of the second electrode 5 through a pipeline (the second pump 9 is arranged on the pipeline), the top of the negative liquid storage tank 2 is connected with the top of the second electrode 5 through a pipeline, and the outer side of the second electrode 5 is in close contact connection with the second current collector 7 to form the negative electrode of the flow battery. A diaphragm 3 is arranged between the positive electrode of the flow battery and the negative electrode of the flow battery, the inner sides of a first electrode 4 and a second electrode 5 are respectively in close contact connection with the two sides of the diaphragm 3, catechol type positive electrolyte is filled in a positive liquid storage tank 1, and negative electrolyte is filled in a negative liquid storage tank 2. During charging, the electrons lost from the positive electrolyte are oxidized, and the electrons obtained from the negative electrolyte are reduced; when discharging, the opposite is realized, namely electrons obtained by the positive electrolyte are reduced, and electrons lost by the negative electrolyte are oxidized.

The following further describes embodiments of the present invention with reference to the drawings and specific examples.