According to the present invention, there are provided
lithium titanate particles which exhibit an excellent initial
discharge capacity and an enhanced high-efficiency
discharge capacity
retention rate as an active substance for non-
aqueous electrolyte secondary batteries and a process for producing the
lithium titanate particles, and Mg-containing
lithium titanate particles. The present invention relates to
lithium titanate particles with a
spinel structure comprising TiO2 in an amount of not more than 1.5%, Li2TiO3 in an amount of not less than 1% and not more than 6%, and Li4Ti5O12 in an amount of not less than 94% and not more than 99% as determined according to Rietveld analysis when indexed with Fd-3m by XRD, and having a specific surface area of 7 to 15 m2 / g as measured by BET method, a process for producing
lithium titanate particles comprising the steps of adding and mixing a water-soluble lithium solution into a water suspension of an
oxide of
titanium having a BET specific surface area of 40 to 400 m2 / g and a primary particle
diameter of 5 to 50 nm and subjecting the resulting mixed suspension to aging reaction at a temperature of 50 to 100° C.; subjecting the resulting
reaction product to
filtration,
drying and pulverization; and subjecting the obtained dry particles to heat-
calcination treatment at a temperature of 550 to 800° C., and Mg-containing
lithium titanate particles having a composition represented by the formula: LixMgyTizO4 wherein x, z>0; 0.01≦y≦0.20; 0.01≦y / z≦0.10; and 0.5≦(x+y) / z≦1.0, the Mg-containing lithium titanate particles having a BET specific surface area of 5 to 50 m2 / g, a
spinel single phase as a
crystal structure, and a
lattice constant (a) represented by a value of 0.050y+8.3595<a≦0.080y+8.3595 (Å).