CN-122025718-A - Application of acetylurea in neutral zinc-manganese flow battery, positive electrode electrolyte of neutral zinc-manganese flow battery and battery

Abstract

The invention relates to the field of batteries, and discloses an application of acetylurea in a neutral zinc-manganese flow battery, a positive electrode electrolyte of the neutral zinc-manganese flow battery and the battery. According to the invention, the acetyl urea is added into the neutral zinc-manganese flow battery positive electrode electrolyte, so that the micro structure and interface property of the electrolyte are further optimized, the ion migration and charge transfer are promoted together, and the problems of low intrinsic conductivity and active substance loss caused by manganese deposition are effectively improved. Under the current density of 20 mA cm-2, the zinc-manganese flow battery adopting the positive electrode electrolyte provided by the invention can realize that the coulomb efficiency is more than 98.3% after 360 cycles, and the energy efficiency is stabilized above 78%.

Inventors

• GUO LEI
• DENG ZHENGKUN
• ZHANG QING
• ZHAO ZHONGNIAN
• TAN YAN
• HE ZHONGYI

Assignees

• 铜仁学院
• 华东交通大学

Dates

Publication Date

20260512

Application Date

20260319

Priority Date

20260112

Claims (10)

1. 1. The application of the acetylurea in the neutral zinc-manganese flow battery.
2. 2. The use of claim 1, wherein the acetylurea is an additive to a positive electrolyte of a neutral zinc manganese flow battery.
3. 3. The positive electrode electrolyte of the neutral zinc-manganese flow battery is characterized by comprising a solvent, a solute and an additive, wherein the additive is acetylurea.
4. 4. The positive electrode electrolyte according to claim 3, wherein the concentration of the acetylurea is 0.05-0.1 mol/L based on the total amount of the positive electrode electrolyte.
5. 5. The positive electrode electrolyte according to claim 3 or 4, wherein the solute comprises a manganese salt and a supporting electrolyte, wherein the supporting electrolyte comprises potassium ions and/or sodium ions.
6. 6. The positive electrode electrolyte according to claim 5, wherein the source of potassium ions comprises one or more of potassium sulfate, potassium chloride, and potassium nitrate.
7. 7. The positive electrode electrolyte according to claim 5, wherein the concentration of the supporting electrolyte is 0.5-3.0 mol/L based on the total amount of the positive electrode electrolyte.
8. 8. The positive electrode electrolyte according to claim 5, wherein the concentration of the manganese salt is 0.2 to 0.5mol/L based on the total amount of the positive electrode electrolyte.
9. 9. The positive electrode electrolyte according to claim 3 or 8, wherein the manganese salt is one or more selected from manganese sulfate, manganese chloride and manganese acetate.
10. 10. A neutral zinc manganese flow battery comprising the positive electrode electrolyte of any one of claims 3-9.

Description

Application of acetylurea in neutral zinc-manganese flow battery, positive electrode electrolyte of neutral zinc-manganese flow battery and battery Technical Field The invention relates to the field of batteries, in particular to application of acetylurea in a neutral zinc-manganese flow battery, positive electrode electrolyte of the neutral zinc-manganese flow battery and the battery. Background The neutral zinc-manganese flow battery is taken as an important branch of the water-based flow battery, and is regarded as one of the technical paths with great potential in the long-term energy storage field by virtue of the advantages of the resources, the intrinsic safety characteristics, the environmental friendliness and the theoretical energy density. In recent years, although the zinc-manganese flow battery has great potential, the progress of the neutral zinc-manganese flow battery towards engineering application still faces the following core bottlenecks, and the commercialization process is severely restricted, namely, the battery operates in a neutral pH environment, and an intermediate product Mn3+ generated under the condition can undergo spontaneous disproportionation reaction, wherein the reaction is as follows: This reaction not only consumes the high valence state mn3+ directly, but also generates additional dead manganese precipitates on the electrode surface, forming a vicious circle of active material consumption-deposit layer deterioration. The traditional system inhibits the disproportionation of Mn < 3+ > by adding the complexing agent, but the strong coordination effect of the complexing agent and Mn < 2+ > can synchronously block the oxidation of Mn < 2+ > to reduce the charging capacity by 15% -20%. In the charging process, the Mn < 2+ > oxidation reaction of the positive electrode is as follows: The generated MnO 2 deposition layer has two defects, namely, the intrinsic conductivity is low, so that ohmic polarization of the electrode surface is increased, the deposition layer is loose in structure, only part of MnO 2 can be effectively dissolved during discharge, and undissolved dead manganese is attached to the electrode surface in the form of insulating particles, so that active substances are permanently lost. Disclosure of Invention The invention aims to solve the problem of MnO 2 deposition layer which is generated by Mn < 2+ > oxidation and exists in the additive in the prior art, and provides an application of acetylurea in a neutral zinc-manganese flow battery, and a positive electrode electrolyte and a battery of the neutral zinc-manganese flow battery. The invention can remarkably improve the problems by adding the acetylurea into the positive electrode electrolyte of the neutral zinc-manganese flow battery. To achieve the above object, the first aspect of the present invention provides an application of acetylurea in a neutral zinc-manganese flow battery. The acetylurea regulates and controls the manganese deposition behavior, and meanwhile, a dynamic hydrogen bond network is formed between molecules and water molecules, so that the microstructure and interface properties of the electrolyte are further optimized, ion migration and charge transfer are promoted together, and the problems of low intrinsic conductivity and active substance loss caused by manganese deposition are effectively solved. Preferably, the acetylurea is an additive for positive electrolyte of a neutral zinc-manganese flow battery. The second aspect of the invention provides a positive electrode electrolyte of a neutral zinc-manganese flow battery, wherein the positive electrode electrolyte comprises a solvent, a solute and an additive, and the additive is acetylurea. By adopting the scheme, the acetyl urea is added into the positive electrode electrolyte, and the micro structure and interface property of the electrolyte are further optimized by utilizing a dynamic hydrogen bond network formed between molecules and water molecules of the acetyl urea while regulating and controlling the manganese deposition behavior, so that the problems of low intrinsic conductivity and active substance loss caused by manganese deposition are effectively improved. Preferably, the concentration of the acetylurea is 0.05 to 0.1mol/L based on the total amount of the positive electrode electrolyte. The concentration of the acetylurea may be any value between any two of 0.05mol/L, 0.06mol/L, 0.07mol/L, 0.08mol/L, 0.09mol/L, 0.1mol/L. Preferably, the solute comprises a manganese salt and a supporting electrolyte, wherein the supporting electrolyte comprises potassium ions and/or sodium ions. By adopting the scheme, the active manganese salt, the supporting electrolyte and the special functional additive acetylurea can form a synergistic effect at a molecular level, so that the reversibility and the dynamic performance of an electrochemical process of Mn < 2+ >/MnO 2 at the positive electrode side are fundamentally improved. Where