High Lithium Electroactivity of Nanometer‐Sized Rutile TiO₂

Nanometer-sized rutile shows much higher electroactivity towards Li insertion than micrometer-sized rutile. Up to 0.8 mol of Li per mole of TiO2 can be inserted into nanometer-sized rutile at room temperature (see figure), which is able to reversibly accommodate Li up to Li0.5TiO2 with excellent capacity retention and high rate capability on cycling, rendering it a promising anode material for high-power lithium-ion batteries.