Solid State Ionics, Vol.262, 124-127, 2014
Structural and transport properties of Li1+xV1-xO2 anode materials for Li-ion batteries
Recently, layered Li1 + xV1 - xO2 with x >= 0 has attracted significant attention as an anode material for Li-ion batteries. Its high volumetric and gravimetric capacities (1360 mAh . cm(-3) and 300 mAh . g(-1) respectively) make it particularly interesting. During lithium intercalation Li1 + xV1 - xO2 with x > 0 exhibits wide potential plateau below 0.1 V vs. Li/Li+, while for stoichiometric LiVO2 lithium uptake hardly occurs. In this work evaluation of crystal structure, transport and electrochemical properties is given for Li1 + xV1 - xO2 materials with x = 0, 0.03 and 0.07. Li1 + xV1 - xO2 showed activated character of conductivity with activation energy about 0.2-0.3 eV. Thermoelectric power values exceeding 80 mu V.K-1 point to electron holes as the main charge carriers. Thermogravimetric measurements carried out in air indicated only minor variations of mass of the materials up to 215 degrees C, suggesting high stability along with low level of oxygen nonstoichiometiy. (C) 2013 Elsevier B.V. All rights reserved.
Keywords:Li-ion batteries;Lithium intercalation;Electrical conductivity;Thermoelectric power;Variable range hopping