Aluminum secondary battery and its electrolyte

Abstract

Aluminum secondary battery and electrolyte thereof, wherein the electrolyte comprises trivalent aluminum salt and is selected from methyl urea, dimethyl urea, trimethyl urea, tetramethyl urea, ethyl urea, diethyl urea, triethyl urea At least one urea among base urea and tetraethyl urea. The electrolyte material of the invention has low cost and low sensitivity to water; the corresponding assembled aluminum secondary battery has high discharge capacity, wide voltage window, good cycle stability and high cost performance, and has good application prospects.

Description

technical field [0001] The present invention generally relates to an aluminum secondary battery; more specifically, it relates to the preparation of its electrolyte solution. Background technique [0002] As the next generation ultra-high capacity battery, the rechargeable aluminum secondary battery has attracted extensive attention and research. As a trivalent metal, Al can provide 3 electrons during charge and discharge, so its theoretical capacity density (8046m Ah cm -3 ) are the monovalent Li-ion batteries (2062m Ah cm -3 ) and divalent magnesium-ion battery (3833m Ah cm -3 ) 4 times and 2 times. In addition, Al is the third most abundant resource in the earth's crust, accounting for about 8% of the earth's crust, and it is easier to obtain and process than Li, so it is cheaper and the production process is more environmentally friendly than Li. At the same time, aluminum-ion batteries have good charge-discharge performance, and can be cycled tens of thousands of ti...

AI Technical Summary

Problems solved by technology

[0003] At present, the electrolytes of aluminum secondary batteries in the research and development stage tend to use imidazolium halides (for example: 1-ethyl-3-methylimidazolium chloride), but imidazolium halides are expensive and very harmful to water. Sensitive, so this electrolyte is very hygroscopic and thus not conducive to large-scale applications

In addition, more importantly, this electrolyte is very corrosive, which can cause strong corrosion to the battery shell, which greatly limits the development of aluminum secondary batteries.

There is also a research report on the use of urea-containing electrolytes ("A long-life rechargeable Al ion battery based on moltensalts", J.Mater.Chem.A, 2017, 5, 1282-1291) concluded that the corresponding battery needs to be in It has good electrochemical performance at high temperature (120°C), which is obviously not conducive to large-scale industrial applications.

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