A material of phosphorus-doped lithium titanium oxide with spinel structure includes a plurality of lithium titanium oxide particles, wherein a portion or the entirety of the surface layer of the lithium titanium oxide particle is doped with phosphorus. The surface layer is from 1 to 10 nanometers in thickness. Alternatively, the entire lithium titanium oxide particle can be doped with phosphorus. The material can be in powdered form, including a plurality of micro-scale particles each constituted by a plurality of the lithium titanium oxide particles.