A new approach for the improvement of Li1+xV3O8 performance in rechargeable Li batteries.

A method for the improvement of the electrochemical properties of Li1+xV3O8 is presented based on the partial modification of its crystal structure by the introduction of small amounts of inorganic compounds, such as H2O, CO2 and NH3. The modification is performed by preliminary insertion of these molecules at high (H2O) or ambient pressure (CO2) or by use of appropriate method of synthesis (NH3). A remarkable specific capacity of about 280 mAh/g has been achieved corresponding to the reversible intercalation of 3 equivalents of Li per mol Li1+xV3O8. The high capacity performance and the good reversibility observed is assigned to the preliminary expansion of the interlayer spacing by the inorganic compounds inserted into it, this leading to an increased mobility and enhanced distribution of the Li+ ions in the Li1+xV3O8 layers.