Spindle Single-Crystalline Rutile TiO2 with Excellent Cyclability for Low-Cost Li-Storage Materials

We investigated the Li storage properties of spindle single-crystalline rutile TiO2 fine particles synthesized by a large-scale sulfate process. Their anode properties were compared with those of polycrystalline rutile TiO2 particles. An increase in the degree of single-crystal formation improved the charge–discharge capacity and initial Coulombic efficiency. In situ X-ray diffraction and transmission electron microscopic observation demonstrated the structural integrity of the spindle particles during the charge–discharge reactions. These results concluded that the degree is a critical parameter determining the anode performance of rutile TiO2. The anode performance was further enhanced by doping Nb into the spindle TiO2 particles. These findings suggest that single-crystalline rutile TiO2 particles are very promising low-cost and high-performance Li storage materials.