CN112993355B - Organic flow battery - Google Patents

Abstract

An organic flow battery comprises a single cell or a cell stack consisting of more than 2 single cells. The monocell comprises a positive electrode, a diaphragm and a negative electrode, wherein the electrolyte of the positive electrode is introduced between the positive electrode and the diaphragm, and the electrolyte of the negative electrode is introduced between the negative electrode and the diaphragm. The positive electrode electrolyte in the positive electrode electrolyte is a dihydroxybiphenyl compound.

Description

An organic flow battery

technical field

The invention belongs to the field of liquid flow batteries, in particular to an organic liquid flow battery.

Background technique

Due to the resource problems and environmental pollution problems of fossil energy, we are gradually increasing the proportion of renewable energy in energy consumption. However, renewable energy sources such as wind energy and solar energy have the disadvantages of being discontinuous, unstable and uncontrollable, causing great economic losses and waste of resources. Therefore, it is necessary to seek an efficient, reliable and safe energy storage technology to improve the quality and utilization of renewable energy. Flow battery has become the most promising large-scale energy storage technology due to its advantages of separate regulation of power and energy, not being restricted by geographical environment, and being safe and reliable.

At present, the relatively mature flow batteries include all-vanadium flow batteries, etc., but all-vanadium flow batteries require the use of high-concentration sulfuric acid, which will cause corrosion to the pipeline, and the limited resources of vanadium and other metals are non-renewable energy sources. Organic flow batteries have received extensive attention due to their wide variety, convenient regulation, low cost, and sustainability.

SUMMARY OF THE INVENTION

For achieving the above object, the concrete technical scheme of the present invention is as follows:

The invention provides an organic liquid flow battery, which includes a single cell or a stack composed of more than two single cells; the single cell includes a positive electrode, a diaphragm, and a negative electrode, the positive electrode electrolyte is passed between the positive electrode and the diaphragm, and the negative electrode electrolyte is passed through. between the negative electrode and the diaphragm; it is characterized in that: the positive electrode electrolyte in the positive electrode electrolyte solution is a dihydroxybiphenyl compound.

In the flow battery, the dihydroxybiphenyl compound is an organic compound represented by the following general formula (1),

In formula (1), Y1 to Y8 each independently represent hydroxyl, hydrogen, fluorine, chlorine, bromine, cyano, nitro, C1-C20 chain saturated hydrocarbon group, C2-C20 chain unsaturated hydrocarbon group, C3-C20 cyclic group One of saturated hydrocarbon group, C3-C20 cyclic unsaturated hydrocarbon group, -COR1 or -N(R2) ₂ ;

R1 and R2 are independently selected from hydrogen, C1-C20 chain saturated hydrocarbon group, C2-C20 chain unsaturated hydrocarbon group, C2-C20 cyclic saturated hydrocarbon group, C3-C20 cyclic unsaturated hydrocarbon group, cyano group, nitro group One of the two R2 in -N(R2) ₂ can be the same or different;

The chain saturated hydrocarbon group, chain unsaturated hydrocarbon group, cyclic saturated hydrocarbon group or cyclic unsaturated hydrocarbon group described in the above-mentioned Y1～Y8 and R1 and R2 optional substituents do not contain or contain selected from oxygen atom, nitrogen atom, At least one of sulfur atoms and silicon atoms.

The flow battery is characterized in that the concentration of the dihydroxybiphenyl compound in the positive electrode electrolyte is a solution from 0.05 mol/L to its saturated concentration.

The organic flow battery is characterized in that the positive electrode or the negative electrode is carbon felt, carbon cloth, carbon paper or graphite plate respectively. The flow battery is characterized in that the negative electrode electrolyte in the negative electrode electrolyte of the flow battery comprises one or more of the following substances: silicotungstic acid, disodium 2,7-anthraquinone-disulfonate , tin tetrachloride, lead sulfate, cadmium chloride, vanadium trichloride. The flow battery is characterized in that the hydroxyl group in the positive electrolyte dihydroxybiphenyl compound in the positive electrode electrolyte undergoes a redox reaction of electron transfer; the negative electrode electrolyte in the negative electrode electrolyte undergoes a redox reaction of electron transfer.

The flow battery is characterized in that the total concentration of the negative electrolyte in the negative electrolyte is a solution from 0.05 mol/L to its saturated concentration.

The flow battery is characterized in that the separator is an ion exchange membrane or a porous membrane.

The flow battery is characterized in that the positive electrolyte and/or the negative electrolyte further includes a supporting electrolyte, and the supporting electrolyte comprises hydrochloric acid, sulfuric acid, perchloric acid, acetic acid, methanesulfonic acid, sulfamic acid , one or more of trifluoromethanesulfonic acid and phosphoric acid, and the concentration of the supporting electrolyte in the electrolyte is 0.05mol/L to 6.0mol/L.

beneficial effect

In an organic liquid flow battery provided by the present invention, dihydroxybiphenyl compound is used as the positive electrode electrolyte of the liquid flow battery, and the dihydroxybiphenyl compound can undergo reversible redox reaction, and has good reversibility and Excellent kinetic properties. In particular, under the condition of acidic supporting electrolyte, the dihydroxybiphenyl compound can show a relatively positive potential, and matching with a suitable negative electrolyte can match the organic flow battery with excellent performance. In addition, the main constituent elements of the dihydroxybiphenyl compound are carbon, hydrogen, and oxygen, and the source of the elements is cheap and abundant, so the cost of the dihydroxybiphenyl compound organic flow battery after mass production and manufacture will be compared with the existing The heavy metal ion flow battery such as vanadium is greatly reduced, and it is conducive to sustainable development, which is suitable for large-scale energy storage technology.

Description of drawings

Fig. 1 is 1,1',1",1"'-(4,4'-dihydroxy-[1,1'-biphenyl]-3,3',5,000 prepared in Example 1 of the present invention, Cyclic voltammetry test results of 5'-tetrayl)tetrakis (N,N-dimethylmethylammonium) (hereinafter referred to as 4,4'-BPTDAM) solution, with saturated calomel as the reference electrode, the scan rate is 10mV /s, 30mV/s, 50mV/s, 70mV/s, 90mV/s, 200mV/s.

Figure 2 is the test results of the 4,4'-BPTTAE solution prepared in Example 1 of the present invention under different cycle times in the cyclic voltammetry test.

Figure 3 is 1,1'-(4,4'-dihydroxy-[1,1'-biphenyl]-3,3'-diyl)bis(N,N-diyl) prepared in Example 2 of the present invention Dimethyl methylammonium) (hereinafter referred to as 4,4'-BPDDAM) solution cyclic voltammetry test results, with saturated calomel as the reference electrode, the scan rate is 10mV/s, 30mV/s, 50mV/s, 70mV/ s, 90mV/s, 200mV/s.

FIG. 4 is an efficiency diagram of the assembled battery in Example 3 of the present invention under different current charging and discharging conditions.

FIG. 5 is a voltage-capacity diagram of the assembled battery in Example 3 of the present invention under different current charging and discharging conditions.

FIG. 6 is a cycle performance diagram of the assembled battery in Example 3 of the present invention at a current of 270 mA.

FIG. 7 is a cycle performance diagram of the assembled battery in Comparative Example 1 of the present invention at a current of 50 mA.

Detailed ways

Example 1

Weigh 4,4'-BPTDAM and 30 ml of 2 mol/L hydrochloric acid solution, shake and stir, and form a 0.001 mol/L 4,4'-BPTDAM solution after forming a uniform solution. The electrolyte prepared above was tested by cyclic voltammetry with a three-electrode system, wherein saturated calomel was used as a reference electrode, a graphite electrode was used as a counter electrode, and a carbon felt electrode was used as a working electrode. The scan rate is 10mV/s, 30mV/s, 50mV/s, 70mV/s, 90mV/s, 200mV/s.

From the cyclic voltammetry data in Figure 1, it can be seen that under this condition, there is a pair of obvious reversible redox peaks, and its electrochemical reversibility is good. When saturated calomel is used as the reference electrode, the average value of 4,4'-BPTDAM The potential is above 0.5V.

From the cyclic voltammetry data under different cycle times in Figure 2, the 5th, 50th, and 100th cyclic voltammetry curves basically overlap, indicating that the stability is good.

Example 2

Weigh 4,4'-BPTDDM and 30 ml of 2 mol/L hydrochloric acid solution, shake and stir, and form a 0.001 mol/L 4,4'-BPTDDM solution after forming a uniform solution. The electrolyte prepared above was tested by cyclic voltammetry with a three-electrode system, wherein saturated calomel was used as a reference electrode, a graphite electrode was used as a counter electrode, and a carbon felt electrode was used as a working electrode. The scan rate is 10mV/s, 30mV/s, 50mV/s, 70mV/s, 90mV/s, 200mV/s.

From the cyclic voltammetry data in Figure 1, it can be seen that under this condition, there is a pair of obvious reversible redox peaks, and its electrochemical reversibility is good. When saturated calomel is used as the reference electrode, the average value of 4,4'-BPTDAM The potential is above 0.5V.

Example 3

Weigh 4,4'-BPTDAM and dissolve it in 8 ml of 2 mol/L hydrochloric acid solution, shake and stir, and after it forms a uniform solution, a 0.1 mol/L 4,4'-BPTDAM solution is used as the positive electrode electrolyte. Weigh 2,7-disulfonic acid-anthraquinone-disodium and dissolve it in 8 ml of 2mol/L hydrochloric acid solution, shake and stir, and configure it into 0.1mol/L 2,7-disulfonic acid after it forms a uniform solution -Anthraquinone-disodium solution as negative electrolyte. The above electrolyte was connected to the flow battery device as the positive and negative electrolyte. The battery was assembled in the order and position of graphite current collector-graphite felt electrode-ion exchange membrane-graphite felt electrode-graphite current collector, and the peristaltic pump was used to drive the liquid to charge and discharge.

As shown in Figure 4, when charging and discharging at currents of 9 mA, 18 mA, 27 mA, 36 mA, and 45 mA, the coulombic efficiency, voltage efficiency and energy efficiency of the flow battery all maintain a high level. As shown in Figure 5, the flow battery maintained a high capacity at different currents. As shown in Figure 6, the flow battery performed charge-discharge cycles at a current of 270 mA, and neither the efficiency nor the capacity were significantly attenuated.

Comparative Example 1

Weigh 2,5-dihydroxybenzenedisulfonic acid disodium salt and dissolve it in 8 ml of 2mol/L hydrochloric acid solution, shake and stir, and after it forms a uniform solution, it becomes 0.1mol/L of 2,5-dihydroxybenzenedisulfonate. Sulfonic acid disodium salt solution was used as the positive electrolyte. Weigh 2,7-disulfonic acid-anthraquinone-disodium and dissolve it in 8 ml of 2mol/L hydrochloric acid solution, shake and stir, and configure it into 0.1mol/L 2,7-disulfonic acid after it forms a uniform solution -Anthraquinone-disodium solution as negative electrolyte. The above electrolyte was connected to the flow battery device as the positive and negative electrolyte. The battery was assembled in the order and position of graphite current collector-carbon paper/graphite felt electrode-ion exchange membrane-carbon paper/graphite felt electrode-graphite current collector, and the liquid was charged and discharged with a peristaltic pump.

As shown in Fig. 7, the flow battery in Comparative Example 1 underwent charge-discharge cycles at a lower current (50 mA), and both the efficiency and capacity were attenuated.

Claims (8)

1. An organic liquid flow battery, comprising a single cell or a stack composed of more than 2 single cells; the single cell comprises a positive electrode, a diaphragm, and a negative electrode, the positive electrode electrolyte is passed between the positive electrode and the diaphragm, and the negative electrode electrolyte is passed into the negative electrode It is characterized in that: the positive electrolyte in the positive electrolyte is a dihydroxybiphenyl compound; the positive electrolyte and the negative electrolyte also include a supporting electrolyte, and the supporting electrolyte contains hydrochloric acid, sulfuric acid, perchloric acid , one or more of acetic acid, methanesulfonic acid, sulfamic acid, trifluoromethanesulfonic acid and phosphoric acid; The dihydroxybiphenyl compound is an organic substance represented by the following general formula (1),

(1) In formula (1), Y1~Y8 independently represent hydrogen, fluorine, chlorine, bromine, hydroxyl, cyano, nitro, sulfonic acid, C1-C20 chain saturated hydrocarbon group, C2-C20 chain unsaturated hydrocarbon group, C3 One of -C20 cyclic saturated hydrocarbon group, C3-C20 cyclic unsaturated hydrocarbon group, -COR1 or -N(R2) ₂ ; R1 and R2 are independently selected from hydrogen, C1-C20 chain saturated hydrocarbon group, C2-C20 chain unsaturated hydrocarbon group, C2-C20 cyclic saturated hydrocarbon group, C3-C20 cyclic unsaturated hydrocarbon group, cyano group, nitro group One of the two R2 in -N(R2) ₂ can be the same or different; The chain saturated hydrocarbon group, chain unsaturated hydrocarbon group, cyclic saturated hydrocarbon group or cyclic unsaturated hydrocarbon group described in the above-mentioned Y1～Y8 and R1 and R2 optional substituents do not contain or contain selected from oxygen atom, nitrogen atom, One or more of at least one of sulfur atoms and silicon atoms. 2 . The flow battery according to claim 1 , wherein the concentration of the dihydroxybiphenyl compound in the positive electrode electrolyte is a solution of 0.05 mol/L to its saturated concentration. 3 . 3 . The organic flow battery according to claim 1 , wherein the positive electrode or the negative electrode is carbon felt, carbon cloth, carbon paper or graphite plate, respectively. 4 . 4. The flow battery according to claim 1, wherein the negative electrolyte in the negative electrolyte of the flow battery comprises one or more of the following substances: silicotungstic acid, 2,7-anthraquinone-di Disodium sulfonate, tin tetrachloride, lead sulfate, cadmium chloride, vanadium trichloride. 5. The flow battery according to claim 1, 2 or 4, characterized in that, in the positive electrolyte dihydroxybiphenyl compound of the positive electrode electrolyte, a redox reaction of electron transfer occurs in the hydroxyl group; The anode electrolyte in the anode electrolyte undergoes a redox reaction of electron transfer. 6 . The flow battery according to claim 5 , wherein the total concentration of the negative electrolyte in the negative electrolyte is a solution from 0.05 mol/L to its saturated concentration. 7 . 7 . The flow battery according to claim 1 , wherein the separator is an ion exchange membrane or a porous membrane. 8 . 8. The flow battery according to claim 1, wherein the concentration of the supporting electrolyte in the electrolyte is 0.05 mol/L～6.0 mol/L.

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