Mixed electrolyte and preparation method and application thereof

Abstract

The invention relates to a mixed electrolyte and a preparation method and an application of the mixed electrolyte. The mixed electrolyte consists of an ionic liquid of dialkyl imidazolium-based diaryliodonium salt and an organic lithium salt that are equimolar. The preparation method comprises the steps of: adding N-methyl imidazole and chlorobutane into a container; then adding solvents of cyclohexane and methylbenzene; performing oil bath, rising temperature, refluxing, cooling and layering; pouring the yellow liquid in the upper layer and filtering and weighing the white crystal in the lower layer; placing the white crystal in the container, adding ethyl acetate and acetonitrile, heating, refluxing and filtering, crystallizing at -15-0 DEG C for 4-8h; re-crystallizing the crystallized product to obtain an intermediate body; dropping LiPF6 aqueous solution slowly into the intermediate body, agitating, and standing still, taking the coarse product in the lower layer and adding AgPF6 for reaction, removing white precipitate after reaction so as to obtain the mixed electrolyte. The mixed electrolyte has the advantages of good lyophobic property, simple preparation method and strongpracticality and can be used to large scale industrialized production. The mixed electrolyte used in lithium air battery can improve the energy density and charge-discharge time of the battery.

Description

technical field [0001] The invention relates to electrolyte preparation technology, in particular to a mixed electrolyte and its preparation method and application. Background technique [0002] A lithium-air battery is a battery that uses lithium as the anode and oxygen in the air as the cathode reactant. Compared with lithium-ion batteries, it has a higher energy density because its cathode active material O 2 It can be obtained directly from the surrounding air without being stored in batteries. Theoretically, since oxygen is used as the cathode and the reactants are not limited, the capacity of the lithium-air battery depends only on the lithium electrode. At the same time, due to the high theoretical specific capacity of Li, the theoretical specific energy of the lithium-air battery can reach 11,140Wh / kg, This theoretical specific energy is higher than all current conventional power systems. Another major factor that determines the performance of lithium-air batteries...

AI Technical Summary

Problems solved by technology

Another major factor that determines the performance of lithium-air batteries is the electrolyte, of which solid electrolytes and gel electrolytes have good reliability and no electrolyte leakage, high specific energy, and wide cycle voltage, but the conductivity of most solid electrolytes at room temperature And the solubility is low; the organic electrolyte system is easy to cause the corrosion of the negative electrode lithium due to the use of water-containing organic solvents in the preparation, resulting in a decrease in the specific capacity of the lithium-air battery and a decrease in the charge-discharge efficiency; and the ionic liquid has a wide electrochemical window. Volatile, recyclable and other advantages, the application of new ionic liquids in the electrolyte research of lithium-air batteries has become a multidisciplinary research frontier

However, the ionic liquids currently used in lithium-air batteries are only in the experimental stage, and their hydrophobic properties are poor, and the preparation methods are complicated, and large-scale industrial production cannot be carried out, which limits their application.