A class of rapid charge and discharge positive electrode active materials, preparation method and applications thereof

Abstract

The invention discloses a class of rapid charge and discharge positive electrode active materials. According to the present invention, the used imide-based small molecules form pi-pi stacking on the plane of a benzene ring, such that the rapid charge and discharge positive electrode active material has good conductivity and insolubility in most common solvents, and is the ionic battery positive electrode material with potential; oxamide and a tetracarboxylic axid dianhydride small molecule are subjected to a reaction to form a polymer, such that the synthesis of the polymer can effectively reduce the solubility in the electrolyte and improve the cycle stability; and by introducing the additional carbonyl between the monomers, the stack of the carbonyl between the molecules form a new ion transport channel to greatly improve the ion transport efficiency, such that the cycle performance and the rate performance of the prepared alkali metal ion battery are substantially improved. The chemical structure general of the imide polymer is defined in the specification.

Description

Technical field [0001] The invention belongs to the technical field of electrode active materials for alkali metal ion batteries, and specifically relates to a type of fast charge-discharge positive electrode active materials, a preparation method thereof, and applications in alkali metal ion batteries. Background technique [0002] With the gradual depletion of oil and other energy sources, the development and storage of new energy has gradually become the focus of social attention. Lithium-ion batteries have been widely used in various small electronic devices and electric vehicles as energy storage devices due to their excellent performance. However, the content of lithium in nature is limited, and with uninterrupted mining, its price is increasing. Sodium and potassium, which are in the first main group with lithium, not only have similar chemical properties to lithium, but also have reserves far exceeding lithium in the earth's crust, so sodium-ion batteries and potassium-i...

AI Technical Summary

Problems solved by technology

Another effective way to improve cycle performance and rate performance is to construct a covalent organic network to inhibit or even eliminate decomposition in the electrolyte and provide faster ion diffusion channels. However, this electrode material with a covalent organic network structure Usually the specific capacity is not high

For now, it is generally believed that although there are four carbonyl active sites in the tetracarboxylic acid imide molecule, too much sodium ion intercalation in the actual reaction process will increase the energy density in the structure and cause structural damage, so generally the most Only two carbonyl groups can undergo stable and reversible redox reactions, and the utilization rate of active sites is generally less than 50%.

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