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

Abstract

The invention discloses a titanium-based lithium ion battery negative electrode material and a preparation method thereof. The preparation method comprises (1) adding tetrabutyl titanate to alcohol, stirring to obtain solution A; (2) mixing absolute ethanol, deionized water and glacial acetic acid, then adding soluble lithium salt and soluble aluminum salt, stirring Obtain solution B evenly; (3) Heat solution A to 40‑50°C, then slowly add solution B to solution A under vigorous stirring conditions, and ultrasonically shake for 8‑15 minutes after the addition is completed, with an ultrasonic frequency of 20‑50 50KHz, then heated to 70-85°C under sealed conditions to react for 8-13h, and the product was dried; (4) The product obtained in step (3) was pulverized and then calcined at 500-600°C under a protective atmosphere , to obtain titanium-based lithium ion battery negative electrode material. The preparation process of the method is simple, the conditions are controllable, and the reaction is mild; the obtained negative electrode material of the titanium-based lithium ion battery has a high initial discharge capacity, good cycle performance, and still has a good discharge capacity at a high rate.

Description

technical field [0001] The invention belongs to the field of new materials, and in particular relates to a titanium-based negative electrode material applied to a lithium battery and a preparation method thereof. Background technique [0002] The new generation of electric vehicles requires the driving power supply to have fast charge and discharge capabilities, while traditional carbon anode materials can no longer meet the high power requirements of power batteries in terms of rate performance and safety performance, so new non-carbon high-power power supplies have been developed. Anode materials for lithium-ion batteries are of great significance. [0003] Titanium-based anode materials (titanium dioxide, lithium titanate) have the advantages of small volume change during charge and discharge, high reversibility, environmental friendliness, and low cost. They are one of the ideal anode materials for high-power lithium-ion batteries, but there are still different Defects,...

AI Technical Summary

Problems solved by technology

[0002] The new generation of electric vehicles requires the driving power supply to have fast charge and discharge capabilities, while traditional carbon anode materials can no longer meet the high power requirements of power batteries in terms of rate performance and safety performance, so new non-carbon high-power power supplies have been developed. Anode materials for lithium-ion batteries are of great significance

[0003] Titanium-based anode materials (titanium dioxide, lithium titanate) have the advantages of small volume change during charge and discharge, high reversibility, environmental friendliness, and low cost. They are one of the ideal anode materials for high-power lithium-ion batteries, but there are still different Defects, in which the theoretical specific capacity of lithium titanate is only 175mAh / g, and the conductivity is poor, which limits the high-current charge and discharge performance of lithium titanate. And the tap density is small, and the specific energy is reduced; while titanium dioxide has its own poor conductivity, which affects electron transmission and limits the high-rate performance, and is prone to agglomeration during high-temperature sintering, forming secondary particles, low initial Coulombic efficiency, and low reversible capacity.

[0004] In order to improve the above-mentioned defects, methods such as coating or doping are often used to improve its electrochemical performance, but the improvement of the obtained material performance is not significant, such as the patent CN107742718A "a lithium titanate negative electrode material with a multi-level structure The preparation method is a composite spherical material prepared by the sol-gel method. Although the performance has been improved, the preparation process is cumbersome and there are many kinds of additives. The first delithiation capacity is not higher than 160mAh / g. The discharge capacity after 100 cycles is not higher than 121mAh / g, and the capacity of charging and discharging at high rates has not been investigated; the patent CN107492647A "lithium ion battery negative electrode material, negative electrode material preparation method and lithium ion battery" discloses that the negative electrode material is nitrogen-doped Heterocarbon-modified lithium titanate has good cycle stability, but its initial discharge capacity is only 118mAh / g