Lithium ion battery negative electrode material and preparation method thereof

Abstract

The invention belongs to the technical field of lithium batteries and relates to a lithium ion battery negative electrode material and a preparation method thereof. The preparation method comprises the following steps of: respectively preparing a Mo5SiB2-ZrB2 compound and a lithium-doped zirconium vanadate material; dispersing the Mo5SiB2-ZrB2 compound and the lithium-doped zirconium vanadate material into a proper amount of distilled water; stirring and mixing the Mo5SiB2-ZrB2 compound and the lithium-doped zirconium vanadate material; transferring the mixture into a hydrothermal automatic reaction kettle, carrying out activation reaction; transferring a product into a reaction bottle; putting the reaction bottle into an ultrasonic dispersion instrument; heating to 70-85 DEG C, carrying out ultrasonic treatment for 2 hours; cooling a solution, and then centrifuging to remove distilled water; and drying a solid product so as to obtain the lithium ion battery negative electrode material. According to the lithium ion battery negative electrode material and the preparation method thereof of the invention, lithium is doped into a zirconium vanadate material, so that the zirconium vanadate material has relatively good thermal shrinkage and cold expansion capabilities, and therefore, the volume change of the lithium ion battery negative electrode material in the charging and discharging process or when the temperature rises can be counteracted, the stability of the lithium ion battery negative electrode material is improved, the internal resistance of the material is reduced, andthe purposes of prolonging the cycle life of the lithium ion battery negative electrode material and improving the rate discharge performance of the material are achieved.

Description

technical field [0001] The invention belongs to the technical field of lithium batteries, and in particular 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 advantages of 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 supply. Automotive power batteries, aerospace energy storage devices. As a key part of promoting the development of lithium-ion batteries, anode materials have become a hot spot for researchers. [0003] Graphite carbon has a series of advantages such as a layered structure suitable for lithium ion intercalation / extraction, good electrical conductivity, chemical stability, and low cost. It is currently the most successful commercial anode material, but the theor...

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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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