Preparation and electrochemical properties of LiMoO/C composites for rechargeable Li-ion batteries.

Layered LiMoO is a potential candidate for a high-capacity positive electrode material for Li-ion batteries because of its excess lithium composition. However, the difficulty of single-phase preparation and its insulating nature are drawbacks for its application in lithium-ion batteries. A small quantity of acetylene black added in the starting material solves these drawbacks, i.e. the formation of impurity phases and the low conductivity. As a result, a LiMoO/C composite is successfully synthesized with the simple addition of acetylene black. Since the electronic conductivity of the composite is enhanced to more than 1000 times higher than that of bare LiMoO, the LiMoO/C composite delivers approximately 230 mA h g of initial discharge capacity in a voltage range of 1.5-4.3 V, while carbon-free LiMoO shows only 110 mA h g of initial discharge capacity. During the initial lithium extraction and insertion, a partial transformation from a layered into a cation-disordered cubic structure is evidenced in the LiMoO/C composite electrode by X-ray diffraction.