A kind of lithium ion battery negative electrode material and preparation method thereof

Abstract

The invention belongs to the technical field of lithium batteries, and specifically relates to a lithium-ion battery negative electrode material and a preparation method thereof. The method includes separately preparing Mo5SiB2-ZrB2 composite and lithium-doped zirconium vanadate material, and then dispersing the two into Appropriate amount of distilled water, stir and mix, then transfer to a hydrothermal automatic reaction kettle for activation reaction, then transfer to a reaction bottle, place in an ultrasonic disperser, heat to 70-85°C, ultrasonicate for 2 hours, cool the solution and centrifuge Remove the distilled water and dry the solid product to obtain the lithium ion battery negative electrode material; in the present invention, lithium is doped into the zirconium vanadate material. The zirconium vanadate material has good thermal shrinkage and cold expansion capabilities and can offset the lithium The volume change of the ion battery anode material during the charge and discharge process, or when the temperature rises, thereby improving the stability of the lithium ion battery anode material, reducing the internal resistance of the material, extending the cycle life of the lithium ion battery anode material and increasing the discharge rate. performance.

Description

Technical field [0001] The invention belongs to the technical field of lithium batteries, and specifically relates to a lithium ion battery negative electrode material and a preparation method thereof. Background technique [0002] Lithium-ion battery is a new type of chemical power source. Because of its high energy density, high working voltage, long life, and no environmental pollution, it is widely used in various portable electronic products and has been used as an electric vehicle or hybrid power source. Automotive power batteries, aerospace energy storage devices. As a key part of promoting the development of lithium-ion batteries, negative electrode materials have become a focus of scientific researchers. [0003] Graphite carbon is currently the most successful commercial anode material due to its layered structure suitable for lithium ion insertion / extraction, good conductivity, chemical stability and low cost. However, the theory of graphite carbon anode material...

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Problems solved by technology

of which NiFe 2 o 4 The theoretical specific capacity is 915mAh / g, which is much higher than that of graphite carbon materials, and has good electrochemical performance (Ding Y, Journal of Power Sources, 2013, 244:610-613), but NiFe 2 o 4 The low conductivity and large volume expansion effect in the charge and discharge process lead to serious capacity fading, large irreversible capacity, and poor cycle performance (Zhao H, Electrochemistry Communication, 2007, 9: 2606-2610; Abrca C V, Journal of Chemical Physics C, 2010 , 114:12828-12832), restricting the development of its practical application

Chinese invention patent (CN103700842A) describes a NiFe 2 o 4 / C Lithium-ion battery negative electrode material and its preparation, the method uses hydrazine as a reducing agent to prepare the negative electrode material precursor in an alkaline environment, and uses non-graphitizable carbon to compound the negative electrode material, and the non-graphitizable carbon can increase the conductivity of the material However, the irreversible capacity of non-graphitized carbon is very high, and there is a phenomenon of voltage hysteresis, which limits the improvement of the electrochemical performance of the material.

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