Investigation On Preparation And Modification Of Lithium Titanate

Owing to its advantages of high power density, low price, low self-discharge, no pollution and no memory effect,Lithium ion battery obtain great success in business and is widely used in in practice. The spinel Lithium Titanate (Li₄Ti₅O₁₂) is a"zero-strain"and perfect insertion electrode materials. Because of its excellent characteristic of reversibility, fast kinetics of charge-discharge process, and safety performance, it makes Li₄Ti₅O₁₂ become the hotspot of research.In this paper, the develop process, work principle, characteristic, anode and cathode materials of Lithium ion battery were summarized. The character, structure, the methods of synthesis and the principle of modification were reviewed. The influence of the synthesis conditions especially the sinter temperature and sinter time of Li₄Ti₅O₁₂ prepared by traditional solid-state reaction were investigated.Carbon doping, carbon coating and ball milling were adopted to improve the performance of Li₄Ti₅O₁₂. The results showed that 10%wt was the better compound carbon doping quantity; The charge transfer resistances of carbon coated Li₄Ti₅O₁₂ reduced as the content of dextrose and sucrose increased, but when the content exceeded 20%wt, the charge transfer resistances don't reduce anymore. The ions of Mg²⁺,Ni³⁺,Sn²⁺ - were doped availably. And their optimal intermingle quantity were studied, their charge transfer resistances were reduced distinctly, and had fast kinetics of charge-discharge process, that made the polarization reduce, reversible capacity and cycle performance improve.Li₄Ti₅O₁₂ was synthesized by sol-gel method,the heated water baths temperature and sinter temperature were investigated.Mg2+could also be doped by sol-gel method. The cyclic stability of doped Li₄Ti₅O₁₂ was preferable than pure Li₄Ti₅O₁₂. The research results showed that substitute quantity (x) equated 0.15 was preferable.