Preparation method of sodium ion battery high capacity graphite negative electrode material

Abstract

The invention discloses a preparation method of a sodium ion battery high capacity graphite negative electrode material. The method comprises the steps of: (1) adding a certain amount of graphite slowly into sulfuric acid with a concentration of 20-80%, then adding an oxidizing agent and a titanium source in order, carrying out stirring reaction in water bath at a constant temperature of 20-70DEG C for 0.5-4h, then performing washing to a ph of 6.0-7.0, conducting filtering, and then carrying out drying at 80-100DEG C to obtain titanium inserted graphite; and (2) placing the titanium inserted graphite obtained in step (1) in an atmosphere furnace at 500-1000DEG C to carry out high-temperature treatment for 4-10h, thus obtaining the sodium-ion battery high capacity graphite negative electrode material. The method provided by the invention inserts the titanium source to the graphite interlayer to enlarge the interlayer spacing of graphite so as to reserve the contraction and expansion space for intercalation and deintercalation of sodium ions, and at the same time broadens the diffusion channel of sodium ions, thus being conducive to enhancing the specific capacity of graphite and improving its rate performance. At the same time, the titanium oxide generated by the titanium source inserted to the interlayer can greatly increase the embedding capacity of the sodium ions, thereby further increasing the specific capacity.

Description

technical field [0001] The invention relates to the technology in the field of negative electrode materials, and in particular provides a method for preparing a high-capacity graphite negative electrode material for a sodium ion battery. Background technique [0002] In recent years, the industrial production of lithium-ion batteries, including positive electrode materials, negative electrode materials, separators, electrolytes, and battery structures, has achieved rapid development. However, with the in-depth development of the lithium-ion battery industry, the problem of shortage of lithium resources is gradually exposed. Lithium element accounts for only 0.002% in the earth's crust and is a rare metal, which not only makes the cost of lithium-ion batteries high, but also limits the development and application of lithium-ion batteries in the long run. [0003] Sodium and lithium are both in the first main group of the periodic table, with similar electrochemical propertie...

AI Technical Summary

Problems solved by technology

This method generates more surface and edge defects by increasing the number of active points for the intercalation or adsorption of sodium ions, which enhances the sodium storage capacity, but the introduction of defects will inevitably affect the first-time efficiency and cycle performance.

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