Method for preparing lithium titanate carbon composite material

Abstract

The invention discloses a method for preparing a lithium titanate carbon composite material, and the method comprises the following steps of: dispersing graphite powder in concentrated sulfuric acid, adding KMnO4 and H2O2 while stirring to obtain a nano graphite oxide material, and preparing an aqueous solution of graphene oxide, thereby obtaining porous graphene material; preparing the porous graphene material into porous graphene solution, and evenly mixing a lithium carbonate / lithium acetate mixture, titanium dioxide and deionized water together through ball milling to obtain slurry; next, mixing the slurry with the porous graphene solution under the stirring condition, thereby obtaining porous graphene and lithium titanate precursor powder; and sintering the precursor powder, thereby obtaining the lithium titanate carbon composite material. The lithium titanate carbon composite cathode material prepared by the method provided by the invention employs the composite material of lithium titanate and porous graphene, and has high multiplying power and ultra-stable cycle performance, and further has high energy density; and therefore, the cathode material is high in specific capacity, good in cycle performance and long in service life if being applied to the lithium ion battery.

Description

technical field [0001] The invention relates to a composite material for lithium batteries, in particular to a lithium titanate carbon composite material and a preparation method thereof. Background technique [0002] Lithium-ion battery, as a new type of secondary battery, has the characteristics of high specific capacity, high voltage, and good safety, and is widely used in the driving power supply of electric vehicles, mobile phones, and notebook computers. With the development of science and technology, various digital products using lithium-ion batteries are updated and upgraded very quickly, and most of the products tend to be portable and economical. This requires lithium-ion battery products to develop in the direction of high energy density and low cost. [0003] At present, the anode materials used in lithium-ion batteries are generally lithium-intercalated carbon materials, such as graphite, soft carbon, hard carbon, etc. There are some problems in these carbon m...

AI Technical Summary

Problems solved by technology

These carbon materials have some problems: (1) but their theoretical capacity (372mAhg-1) is limited, (2) there is a safety hazard in the decomposition of the electrolyte, (3) the first charge and discharge efficiency is low

[0005]However, since lithium titanate is an insulating material, its electrical conductivity is low, which leads to the problem of poor rate performance in the application of lithium batteries. When working in the environment, the specific capacity of lithium titanate decays rapidly

However, with the development of science and technology, the electrochemical performance of single spinel Li4Ti5O12, especially its rate and cycle Performance is still not ideal