High-stability gel electrolyte for zinc-air battery, and preparation method of high-stability gel electrolyte

Abstract

The invention discloses a high-stability gel electrolyte for a zinc-air battery and a preparation method of the high-stability gel electrolyte, and belongs to the field of new energy materials, wherein a polymer gel adsorbs a low-concentration alkaline electrolyte aqueous solution containing an organic weak-acid strong-alkali salt additive and then is swollen to prepare the gel electrolyte. According to the invention, the solutes of the electrolyte are potassium hydroxide, sodium hydroxide and other strong alkalis, organic weak acid and strong alkali salt additives (formate, acetate, benzoateand the like) and organic acid radicals, so that the electrolyte can still provide high-concentration hydroxyl ions required by electrode reaction under the condition of lower alkali concentration; the alkali concentration of the gel electrolyte prepared by the method is greatly reduced, so that the corrosion of the high-concentration alkali electrolyte to a zinc negative electrode is remarkably reduced; and the quasi-solid-state zinc-air battery using the gel electrolyte inhibits the self-discharge phenomenon of the battery while ensuring the stable operation of the battery.

Description

technical field [0001] The invention belongs to the field of new energy materials, and in particular relates to a high-stability gel electrolyte for a zinc-air battery and a preparation method thereof. Background technique [0002] Metal zinc has the characteristics of abundant reserves in the earth's crust, environmental friendliness, and high safety. It is a class of new energy devices with good prospects. In addition, the electrochemical redox window of metal zinc is within the stable potential window of the aqueous electrolyte solution, so it can be directly used as the negative electrode of the aqueous electrolyte electrochemical device (Chem. Rev., 2014, 114, 11683-11720). Among them, the alkaline zinc negative electrode battery is the most widely used because of its high voltage, high specific capacity, and high conductivity of its electrolyte. [0003] As a new energy device with high energy density, half energy storage and half fuel cell, metal-air battery is a str...

AI Technical Summary

Problems solved by technology

Faced with the same problem as the traditional alkaline liquid electrolyte zinc-air battery, in order to ensure high conductivity, the concentration of potassium hydroxide is between 26% and 30% (Int. J. Energy Res., 2016, 40, 1032-1049 ), but in a solid-state alkaline zinc-air battery, a strong alkaline solution corrodes the zinc anode to form Zn(OH) 4 2- , zinc oxide, etc., which reduce the battery capacity and seriously affect the battery life

At the same time, the discharge products gradually cover the surface of the negative electrode, making it difficult for the reaction to continue

In addition, the reduction potential of Zn / ZnO is lower than the hydrogen evolution potential under strong alkali conditions, and the occurrence of hydrogen evolution side reactions will also lead to a decrease in the overall Coulombic efficiency during the period, and even cause safety issues (Nano Energy, 2020, 70, 104523; Angew. Chem. Int. Ed., 2020, 59, 9377-9381)

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