A kind of preparation method of enriching strontium element on the surface of nanometer lithium titanate

Abstract

The invention discloses a preparation method for enriching strontium element on a nano lithium titanate surface. A small amount of strontium element is introduced through an improved sol-gel method so as to prepare a Li4Ti5O12 negative electrode material on the surface on which the strontium element is enriched. The strontium element can be spontaneously enriched on the particle surface in an oxide form under the proper sintering condition, the lithium titanate particles prepared by the method after high energy ball milling are uniform in particle size and excellent in dispersion effect, and the particle aggregation phenomenon is obviously improved. The strontium oxide enriched on the material particle surface can effectively prevent organic electrolyte from being directly contacted with the lithium titanate and inhibiting an air bulking phenomenon caused by electrolyte decomposition catalyzed by a Ti-O bond in the charging and discharging process. The prepared Li4Ti5O12 material has high charge and discharge capacity and stable cycle performance, the first discharge capacity at the 1C rate under room temperature conditions reaches 174.5mAh / g and is close to theoretical capacity, the discharge capacity reaches 120mAh / g or higher under the 10C rate, and the Li4Ti5O12 material has wide application prospects in the fields of portable civil electronic equipment even power equipment.

Description

technical field [0001] The invention relates to the field of lithium ion batteries, in particular to a preparation method for enriching strontium elements on the surface of nanometer lithium titanate. Background technique [0002] At present, lithium-ion batteries occupy the largest market share of rechargeable batteries, and are widely used in civilian portable electronic devices such as mobile phones, notebook computers, and MP3 players. In recent years, people have gradually applied them to power equipment. Hybrid vehicles have also entered the market. The negative electrode materials used in commercially available lithium-ion batteries are mostly carbon materials, but it has a fatal problem, that is, when the battery is charged quickly or overcharged, metal lithium may be precipitated on the surface of the electrode material, and dendrites may form to cause a short circuit. This will not only reduce the service life of the product, but also pose potential safety hazards...

AI Technical Summary

Problems solved by technology

[0004] About Li 4 Ti 5 o 12 Most of the studies on the modification of chelating agents use a chelating agent alone, such as the most classic citric acid chelating agent, because a citric acid molecule can only chelate with one metal ion, there may be a local distribution of metal ions The problem of imbalance will also have a certain impact on the complexation speed

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