Synthesis and electrochemical properties of (1-x)Li4/3Ti5/3O4-xLi1/2Cr5/2O4 spinel structure as anode materials for lithium secondary batteries.

초록

The carbonaceous materials as lithium intercalation anode has commercialized widely in secondary lithium ion batteries. Conventional anode materials, carbon and graphite, have a theoretical maximum capacity of 372 mAh/g, or a volumetric capacity of 800 mAh/cm3, corresponding to the intercalation of one lithium per six carbon atoms. But the use of these materials presents a major drawback, like a capacity fading and the irreversible reactions which occur during the initial charge period. So, many research groups have studied to find alternative materials to substitute for the presently used carbonaceous negative electrode composites. Recently research has sequentially led to the discovery of new materials, such as vanadates, amorphous tin composit oxide (ATCO), or transition metal oxides. In this study, the spinel (1-x)Li4/3Ti5/3O4-xLi1/2Cr5/2O4 (0≤x≤0.5) were synthesized by sol-gel method. The electrochemical performance of these materials were evaluated using 2032 coin cell at C/10 rate. Spinel Li4/3Ti5/3O4(x=0) and LiCrTiO4(x=0.5) are exhibited a reversible capacity of approximately 163 mAh/g and 154 mAh/g with excellent cycleability in 1.2∼3 V after 50 cycles, respectively.