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Different ceramic synthesis conditions of ramsdellite LiTiO have been investigated in order to determine the influence on the electrochemical performances as the negative electrode of lithium-ion batteries. Lithium source, thermal pretreatment, synthesis temperature, and time of reactions were the analyzed conditions. A convenient and cheap reagent like LiCO treated with TiO at high temperature (1250 °C) for very short time (2 h) provides a reliable active material. When tested versus lithium, the initial specific capacity (150 mAh g) is lower than that of ceramic samples prepared at lower temperature or for longer treatment times (ca. 170 mAh g). The lower initial capacity is attributed to the large particle size obtained at high temperature. However, advantageously the capacity retention of the former is superior. Thus, 115 mAh g at C/20 rate is fairly kept (77 % retention) after 100 cycles. The better cyclability of samples prepared at high temperature (with large particle size) is likely due to lower surface reactivity that compensates the lower initial discharge capacity when cycling. A compromise between high initial capacity and capacity retention must be reached when using LiTiO as a battery electrode. The good behavior of the optimized material is shown by testing it against commercial LiCoO as the positive electrode. The high capacity (ca. 135 mAh g) and outstanding cyclability observed prove that optimized ramsdellite may be effectively used as a long-life negative electrode material. [ABSTRACT FROM AUTHOR]

The effect of mechanical grinding on the electrochemical properties of Li2Ti3O7 regarding lithium insertion is studied. X-ray diffraction experiments of milling compounds showed a progressively amorphization of the crystalline material due to both crystalline size decreasing and internal strain increasing. These structural modifications are reflected in the electrochemical behavior of Li2Ti3O7, when it is used as the positive electrode in lithium cells. As a function of milling time a higher specific capacity is obtained during the first discharge of the cell, but when charging an increasing in the irreversible capacity is observed. The most promising Li2Ti3O7 based electrode has been achieved, under our experimental conditions, for 13 hours milling that produces a compound with crystallite size of approximately 20 nm. [ABSTRACT FROM AUTHOR]