Preparation method of spinel lithium titanate

Abstract

The invention relates to the technical field of battery materials, and particularly relates to a preparation method of spinel lithium titanate. The preparation method comprises the following steps of: mixing nano titanium dioxide as a titanium source and lithium salts as a lithium source and fused salt in different proportions, adding anhydrous alcohol, carrying out ball milling, and drying in a vacuum drying oven; and carrying out sectionalized thermal insulation, cooling to room temperature, and grinding to obtain spinel lithium titanate. According to the invention, the advantages in the traditional solid-phase method and liquid-phase method are absorbed: the low-temperature fused salt is used as a reaction medium, so that the diffusion rate of the reactants in the fused salt is obviously higher than that in a solid-phase environment, thereby effectively increasing the reaction rate, shortening the reaction time and saving the energy; and the prepared spinel lithium titanate used as the negative electrode of a lithium secondary battery has excellent electrochemical properties, and thus has wide application prospects.

Description

technical field [0001] The invention relates to the technical field of battery materials, in particular to a method for preparing spinel lithium titanate used for negative electrodes of lithium secondary batteries. Background technique [0002] At present, most commercial lithium-ion battery anode materials use carbon materials, which have some disadvantages: not only the precipitation of lithium dendrites, poor safety, low first-time Coulombic efficiency, and interaction with the electrolyte; but also poor cycle stability and obvious voltage hysteresis , The preparation method is more complicated. Compared with carbon anode materials, alloy-based anode materials generally have higher specific capacity, but have poor cycle performance and large volume change. [0003] The spinel titanic acid (Li 4 Ti 5 o 12 ) has obvious advantages: (1), it is a zero-strain material, with a large ion diffusion coefficient and high thermal stability; (2), a good charge and discharge platf...

AI Technical Summary

Problems solved by technology

[0002] At present, most commercial lithium-ion battery anode materials use carbon materials, which have some disadvantages: not only the precipitation of lithium dendrites, poor safety, low first-time Coulombic efficiency, and interaction with the electrolyte; but also poor cycle stability and obvious voltage hysteresis , the preparation method is more complicated

The traditional solid-phase method has a simple process, but the raw materials need to be ground and mixed for a long time, and the degree of uniformity of mixing directly affects the performance of the product. The reaction diffusion speed is slow, the product particle distribution is uneven, and the bulk density is low. Long heat treatment time, high energy consumption

Compared with the solid-phase reaction, the product prepared by the liquid-phase method has high chemical purity, good uniformity, low heat treatment temperature, and short reaction time, but the cost increases due to the addition of organic compounds during the synthesis process.

Images