Preparation method of high-capacity iron-based lithium ion battery cathode material alpha-LiFeO2

Abstract

The invention belongs to the field of lithium batteries, and provides a preparation method of a high-capacity iron-based lithium ion battery cathode material, that is, alpha-LiFeO2 to overcome the defects of the complicated synthesis method of the existing alpha-LiFeO2 cathode material, low electrochemical performance, complicated structure, unpurified product and the like. The method for synthesizing at the room temperature is adopted, alpha-LiFeO2 is prepared by strictly controlling the molar ratio of Li<+> / Fe<3+>, various reactants are dissolved into absolute ethyl alcohol and are directly synthesized into alpha-LiFeO2 at the room temperature through magnetic stirring, metal lithium is introduced in the reaction process to serve as a reduction protective agent, an alpha-LiFeO2 product rich in lithium is obtained, the product is centrifuged, separated, washed, dried, grinded, refined and dried to obtain the lithium ion battery cathode material alpha-LiFeO2; the material has no impurity, is high in purity, single in phase and even in particle size distribution, the first specific discharge capacities respectively reach 450 mAh / g, 260 mAh / g and 202 mAh / g at the charge-discharge rates of 0.1 C, 0.2 C and 0.5 C; and in addition, the manufacturing cost is low, the synthesis method is simple, and the preparation method is suitable for large-scale industrial production.

Description

technical field [0001] The invention belongs to the field of lithium-ion batteries, and relates to a high-capacity iron-based lithium-ion battery cathode material α-LiFeO 2 method of preparation. Background technique [0002] The non-renewability and high pollution of traditional energy force people to constantly seek new alternative energy sources with high specific energy and low pollution. The second United Nations Environment Conference focused on green and sustainable development, focusing on the development and utilization of green new energy. As a big energy consumer, China has been making great efforts to develop green new energy. Lithium-ion secondary batteries have been widely studied and applied because of their advantages such as high energy density, long cycle life, no memory effect, reusability, environmental friendliness, and no pollution. It is also the main energy supply system for power stations and portable mobile electronic products, and it is also a ne...

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Problems solved by technology

[0006] The purpose of the present invention is to aim at existing α-LiFeO 2 Due to the shortcomings of complex synthesis methods, poor electrochemical performance, complex structure, and impure products, a high-capacity iron-based lithium-ion battery cathode material α-LiFeO is provided. 2 The preparation method; This method adopts the synthetic method at room temperature, by strictly controlling Li + / Fe 3+ Preparation of α-LiFeO by Molar Ratio 2 , whose main feature is to dissolve the reactants in absolute ethanol and directly synthesize α-LiFeO by magnetic stirring at room temperature 2 , Lithium-rich α-LiFeO can be obtained by introducing metallic lithium as a reducing protective agent during the reaction 2 The product, the obtained product is dried after centrifugal separation and washing, and then ground and refined, and then dried to obtain a lithium-ion battery α-LiFeO with excellent electrochemical performance. 2 positive electrode material; and, the manufacturing cost is low, the synthesis method is simple, suitable for large-scale industrial production

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