CN102244285A

CN102244285A - High-concentration zinc-vanadium redox battery

Info

Publication number: CN102244285A
Application number: CN2011101349054A
Authority: CN
Inventors: 周德璧; 周成壁
Original assignee: Individual
Current assignee: Individual
Priority date: 2011-05-24
Filing date: 2011-05-24
Publication date: 2011-11-16
Anticipated expiration: 2031-05-24
Also published as: CN102244285B

Abstract

The invention discloses a high-concentration zinc-vanadium redox battery, which is a novel zinc-vanadium redox battery taking a vanadium ion solution as an anode active material and taking zinc and a zinc ion solution as a cathode active material, wherein the equilibrium potential is 1.76V in a standard state, and the open-circuit voltage is 1.7-2.0V in a charging state. The vanadium ion solution mainly contains vanadium ions in pentavalent and tetravalent (V (I) and V (IV)) valence states, the total vanadium concentration can reach 4.0mol/L, and the solvent is inorganic acid or organic acid. The zinc ion solution is zinc ions and electrolyte containing organic acid or inorganic acid. The organic acid is methanesulfonic acid or sulfamic acid. The inorganic acid is sulfuric acid or nitric acid. High energy density redox cells can be developed according to the present invention.

Description

High-concentration zinc-vanadium redox battery

Technical Field

The invention belongs to the technical field of chemical power supplies, and particularly relates to a high-concentration zinc-vanadium redox battery consisting of a vanadium ion electrolyte as a positive electrode active substance and zinc and a zinc ion electrolyte as a negative electrode active substance.

Background

In the current energy field, renewable energy sources such as solar energy, wind energy and the like are more and more concerned by people, and in order to realize the stability of power supply, an efficient large-scale energy storage technology needs to be developed. Secondary batteries are an important energy storage technology. Among them, redox flow batteries such as all-vanadium batteries, zinc-bromine batteries, sodium polysulfide/bromine batteries, etc. are gradually put into the market because they have special advantages in the large-scale storage direction.

Redox flow batteries are a particular type of redox battery. The positive and negative electrolytes of such batteries are stored in two reservoirs, respectively. In the operation process, the positive electrolyte and the negative electrolyte respectively flow through the positive half cell and the negative half cell under the pushing of the external force of the pump. The capacity of such batteries is determined by the volume of the reservoir and can be adjusted according to the user's requirements. The battery has the advantages of high energy conversion efficiency, long service life, high safety, environmental friendliness and the like, and becomes a renewable energy source such as wind energy and solar energy and a standardized energy storage technology such as electric energy peak clipping and valley filling.

The all-vanadium redox flow battery is a mature oxidation-reduction battery developed at home and abroad at present. The battery uses electrolyte containing vanadium ions as an active material. In the acidic medium, vanadium exists in four valence states, i.e., V (V) in the form of V-valent vanadium, V (IV) in the form of IV-valent vanadium, V (III) in the form of III-valent vanadium, and V (II) in the form of II-valent vanadium. V (V) and V (IV) form a redox couple V (V)/V (IV), and the standard redox potential of the redox couple V (V)/V (IV) is 1.004V; v (III) and V (II) form a redox couple V (II)/V (IIII) with a redox potential of-0.255V. The electrolyte mainly containing V (V) and V (IV) can be used as the positive electrolyte of the battery, and the electrolyte mainly containing V (II) and V (IIII) can be used as the negative electrolyte of the battery. The positive electrolyte and the negative electrolyte are respectively used as positive and negative active materials to form a redox battery, namely an all-vanadium redox flow battery, the balance potential of the battery in a standard state is 1.25V, and the open-circuit voltage of the battery in a charging state is 1.26-1.48V.

An important disadvantage of all-vanadium flow batteries is the low voltage (theoretical voltage 1.25V), one of the main factors of which is that the theoretical potential of the negative electrode is not negative enough (at-0.255V). In addition, the positive electrolyte and the negative electrolyte of the all-vanadium battery developed at present adopt sulfuric acid as a solvent, and the concentration of vanadium ions in the electrolyte is low (below 1.8 mol/L), so that the improvement of the energy density of the battery is also limited.

Zinc is an excellent anode material. The zinc and zinc ions form a redox couple Zn (II)/Zn, the standard potential is-0.76V, and the redox couple is the highest energy couple capable of realizing redox circulation in an aqueous solution system at normal temperature. It is widely used in primary and secondary batteries, such as zinc-manganese battery and zinc-nickel battery.

The zinc cathode is applied to the redox battery, and researchers at home and abroad are developing zinc-bromine flow batteries. The positive electrode of the battery is bromine, and the negative electrode of the battery is zinc. The battery has higher energy density and lower cost. However, bromine is a highly corrosive halogen element, and during battery operation, the electrode material is corroded and rapidly ages, greatly reducing the battery life. In addition, the modified metal has strong diffusivity and is easy to penetrate through the diaphragm to directly react with zinc, thereby causing serious self-discharge loss. These factors have presented obstacles to the development of zinc bromine batteries.

Disclosure of Invention

The invention aims to overcome the defects and develop a high-concentration zinc-vanadium redox battery, which is formed by combining a positive electrode electrolyte taking vanadium ions as a main active substance and a zinc and zinc ion electrolyte as a negative electrode active substance. Meanwhile, the high-energy-density zinc-vanadium redox battery is realized by preparing the high-concentration vanadium electrolyte. The battery can be applied to large-scale energy storage and can also be applied to an electric vehicle as a power battery.

The electrolyte of the redox cell may be of the flow type or of the non-flow type.

The zinc-vanadium redox battery is formed by taking vanadium ion electrolyte as a positive active material and taking zinc and zinc ion electrolyte as a negative active material. In the vanadium ion electrolyte, vanadium ions mainly exist in a valence state of IV vanadium and V vanadium to form a redox couple V (V)/V (VI), and the theoretical potential of the redox couple is 1.004V. The zinc ion is Zn (II), and forms a redox couple Zn (II)/Zn with zinc, and the potential of the redox couple is 0.76V. The balance potential of the formed zinc-vanadium redox battery in a standard state is 1.76V, and the open-circuit voltage in a charging state is 1.76-2.0V, which is greatly higher than that of an all-vanadium redox battery.

In one aspect of the invention, a high concentration vanadium ion electrolyte is provided. The electrolyte can adopt inorganic acid or organic acid as a solvent, or can adopt mixed acid of the inorganic acid and the organic acid as the solvent, and the total vanadium concentration can reach 2.0-4.0mol/L. The inorganic acid is sulfuric acid or nitric acid, and the organic acid is methanesulfonic acid or sulfamic acid.

In another aspect of the present invention, a technique for realizing a high-performance negative electrode electrolyte is provided. The high performance mentioned here means that the zinc ion solubility is high and stable, and the electrolyte component is beneficial to inhibiting hydrogen evolution and dendritic growth in the zinc deposition process. The technology is characterized in that the electrolyte can adopt inorganic acid or organic acid as a solvent, or can adopt mixed acid of the inorganic acid and the organic acid as the solvent, and the concentration of zinc ions can reach 2mol/L. The inorganic acid is sulfuric acid or nitric acid, and the organic acid is methanesulfonic acid or sulfamic acid. The technology is also characterized in that the additive is added into the electrolyte, and the beta-naphthol polyoxyethylene ether is added into the electrolyte, so that the zinc deposition and dissolution performance is good, the hydrogen evolution can be inhibited, and the current efficiency is improved.

The redox cell may be of the electrolyte flow type or of the non-flow type.

Drawings

FIG. 1 is a graph showing the charge and discharge performance of a zinc-vanadium battery of the present invention.

Detailed Description

The invention relates to a high-concentration zinc-vanadium redox battery, which is concretely described by a redox battery comprising the electrolyte. It will be appreciated by those skilled in the art that the following detailed description is provided to facilitate an understanding of the invention and is not intended to limit the scope of the invention.

The positive electrolyte and the negative electrolyte with the total vanadium concentration of 3.0mol/L, which are prepared by the method, are assembled into a zinc-vanadium redox battery, and the charge and discharge performance test is carried out. The results were good. Since the battery voltage and the concentration of the active material in the redox battery determine the energy density of the battery, and the total vanadium concentration in the vanadium-containing ions as the active material in the electrolyte is higher, the redox battery prepared has a higher energy density.

Examples

Description of the invention: in the examples described below, SA represents methanesulfonic acid.

Example 1: VO (SA) ₂ The preparation of (1) weighing proper amount of methanesulfonic acid and V ₂ O ₅ . . Placing methanesulfonic acid in a small beaker, adding a proper amount of distilled water, and adding V ₂ O ₅ Adding into the solution, and gradually adding oxalic acid until V ₂ O ₅ The dissolution is complete. VO (SA) capable of being configured up to 4.5mol/L ₂ And (3) solution.

The preparation method comprises the following steps:

(1) weighing V ₂ O ₅ 41.0g.

(2) A small amount of distilled water was added to the organic acid in a 250ml beaker.

(3) Will be weighed as V ₂ O ₅ All were added to the beaker of (2).

(4) Adding oxalic acid while stirring until V ₂ O ₅ The dissolution is complete.

(5) Adding distilled water to a constant volume of 100ml to obtain the product.

Example 2: preparation of negative zinc sulfate electrolyte

Taking 107.84gZnSO ₄ ·7H ₂ And O, dissolving a certain amount of distilled water in a beaker, adding 0.01g of bone glue, and adding thiourea to ensure that the content of thiourea in the solution is 1wt%. Transferring into a 250mL volumetric flask, adding distilled water to a constant volume, and standing to obtain 1.5 mol.L ^-1 Zinc sulphate solution.

Example 3: preparation of negative electrode solution additive (beta-naphthol polyoxyethylene ether)

56.96g beta-naphthol and 100mL ethylene oxide are taken to be put into an FDK-autoclave controller, 1.58g NaOH is added at the temperature of 40-50 ℃, and 4mL98 percent concentrated H is dripped ₂ SO ₄ Then adding 7.74mL50% of H ₂ SO ₄ Stirring and reacting for 5 hours in a high-pressure kettle at the temperature of 40-50 ℃ to obtain the target product beta-naphthol polyoxyethylene ether. After the reaction is completed, the mixture is filtered, recrystallized and dried for later use.

Example 4: zn-V battery

The positive electrode and the negative electrode of the battery are separated by a cation exchange membrane, the positive electrode material is a carbon felt, and the negative electrode is a zinc sheet. The positive electrode solution is 3mol/LVO (SA) ₂ (ii) a The negative electrode solution is 1mol/LZn (SA) ₂ . Charging and discharging current of 160mA at charging and dischargingThe method comprises the following steps: 1 hour, the maximum charging voltage is 2.6V. The maximum discharge voltage reaches 1.7V, the discharge time of more than 1V in one cycle can reach 48min, and the discharge time of more than 0.1V can reach 56min.

The main advantage is that the battery discharge voltage is higher compared to all vanadium batteries. The charge and discharge performance is shown in fig. 1.

Claims

1. A high-concentration zinc-vanadium redox battery is characterized in that a vanadium ion electrolyte is used as a positive electrode active substance, zinc and the zinc ion electrolyte are used as negative electrode active substances to form the zinc-vanadium redox battery, the equilibrium potential of the battery in a standard state is 1.76V, the open circuit voltage in a charging state is 1.7-2.0V, vanadium ions mainly exist in pentavalent and tetravalent (V (I) and V (IV)) valence states, the total vanadium concentration can reach 4.0mol/L, the vanadium ion electrolyte adopts an inorganic acid or an organic acid as a solvent, or adopts a mixed acid of the inorganic acid and the organic acid as a solvent, the inorganic acid is sulfuric acid or nitric acid, and the organic acid is methanesulfonic acid or sulfamic acid.

2. The high concentration zinc vanadium redox cell of claim 1, wherein the zinc and zinc ion electrolyte, the zinc ion being Zn (II), and the zinc constitutes a redox couple Zn (II)/Zn.

3. The high concentration zinc-vanadium redox cell as claimed in claim 1 wherein the additive of zinc ion electrolyte is added with beta-naphthol polyoxyethylene ether, the zinc deposition and dissolution performance is good, and hydrogen evolution is inhibited and the current efficiency is improved.

4. The high concentration zinc vanadium redox cell of claim 1 in which the electrolyte is of the flow or non-flow type.

5. The high concentration zinc vanadium redox cell of claim 1, wherein VO (SA) ₂ The preparation of (2): weighing proper amount of methanesulfonic acid and V ₂ O ₅ . . Placing the methanesulfonic acid in a small beaker, adding a proper amount of distilled water, and adding V ₂ O ₅ Adding into the solution, and gradually adding oxalic acid until V ₂ O ₅ The dissolution is complete. VO (SA) capable of being configured up to 4.5mol/L ₂ A solution;

the preparation method comprises the following steps:

(1) weighing V ₂ O ₅ 41.0g；

(2) Adding a small amount of distilled water into organic acid in a 250ml beaker;

(3) will call V ₂ O ₅ Adding all the materials into a beaker (2);

(4) adding oxalic acid while stirring until V ₂ O ₅ Completely dissolving;

(5) adding distilled water to a constant volume of 100ml to obtain the product.

6. The high concentration zinc vanadium redox cell of claim 1 wherein the negative zinc sulfate electrolyte is prepared by: taking 107.84gZnSO ₄ ·7H ₂ Dissolving in distilled water, adding bone glue 0.01g, and adding thiourea to make the content of thiourea in the solution 1wt%. Transferring into a 250mL volumetric flask, adding distilled water to a constant volume, and standing to obtain 1.5 mol.L ^-1 Zinc sulphate solution.

7. The preparation of the high-concentration zinc-vanadium redox battery of claim 1, wherein the negative electrolyte additive (beta-naphthol polyoxyethylene ether) is prepared by the following steps: 56.96g beta-naphthol and 100mL ethylene oxide are taken to be put into an FDK-autoclave controller, 1.58g NaOH is added at the temperature of 40-50 ℃, and 4mL98 percent concentrated H is dripped ₂ SO ₄ Then adding 7.74mL50% of H ₂ SO ₄ Stirring and reacting for 5 hours in a high-pressure kettle at the temperature of 40-50 ℃ to obtain the target product beta-naphthol polyoxyethylene ether. After the reaction is completed, the mixture is filtered, recrystallized and dried for later use.

8. The high concentration zinc vanadium redox cell of claim 1 characterized by Zn-V cell preparation, cellThe positive and negative electrode cavities are separated by a cation exchange membrane, the positive electrode material is carbon felt, the negative electrode is zinc sheet, and the positive electrode solution is 3mol/LVO (SA) ₂ (ii) a The negative electrode solution is 1mol/LZn (SA) ₂ Charging and discharging current 160mA, charging and discharging time: 1 hour, the highest charge voltage is 2.6V, the highest discharge voltage reaches 1.7V, the discharge time of more than 1V in one cycle can reach 48min, and the discharge time of more than 0.1V can reach 56min.