A kind of nano lithium titanate composite material and its preparation method, lithium titanate battery

Abstract

The invention provides a nano lithium titanate composite, a preparation method thereof and a lithium titanate battery. The nano lithium titanate composite adopts a hollow sphere structure, the core is hollow, and the shell is lithium titanate and organic high-polymer carbon microspheres which cover the outer surface of lithium titanate and contain aluminum oxide. Sulfonated polystyrene microspheres are used as a template, a secondary template is formed after addition of titanium dioxide, then a lithium compound is added, a sulfonated polystyrene / lithium titanate composite is obtained after even mixing and drying, a solvent is added to dissolve the sulfonated polystyrene microspheres, the material is added to a high-polymer carbon microsphere mixed solution to be dispersed and soaked, and the nano lithium titanate composite is obtained after filtration. The hollow structure of the obtained material and the organic high-polymer carbon microspheres which are arranged on the outer layer and contain aluminum oxide have a synergistic effect, the liquid absorption and retention capacity, the expansion rate, gram volume and the like of the material can be effectively improved, and the rate capability, cycle performance and safety of the lithium ion battery are finally realized.

Description

technical field [0001] The invention relates to a nanometer lithium titanate composite material and a preparation method thereof, a lithium titanate battery, and belongs to the field of preparation of negative electrode materials for lithium ion batteries. Background technique [0002] With the continuous expansion of the market application scope of supercapacitors with high power characteristics and long cycle characteristics, especially in the field of public transportation, higher energy density, safety, service life and rate performance of core electrode energy storage materials have been proposed. requirements. Among the current negative electrode materials for batteries, lithium titanate (Li 4 Ti 5 O 12 ) has become the best choice for hybrid capacitor anode materials because of its unique advantages such as long cycle life, strong charge-discharge performance at high currents, and almost no deformation of the crystal skeleton structure. [0003] However, as a meta...

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Problems solved by technology

[0004] Patent Publication No. CN104617270A discloses a preparation method of a spherical hollow lithium titanate / graphene composite material as a lithium titanate negative electrode material. The method uses a template method to prepare a core-shell structure of silica@titania, and then uses lithium hydroxide as a The lithium source converts titanium dioxide into lithium titanate through hydrothermal reaction, and at the same time removes the internal silicon dioxide by corrosion with the help of lithium hydroxide to generate lithium titanate with a hollow structure, but its template uses inorganic silicon dioxide, and there is silicon dioxide to remove it. The disadvantage of uncleanness reduces the purity of the material, and then the gram capacity is low and the cycle performance is reduced

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