A rechargeable lithium battery has a positive electrode, a negative electrode and a non-aqueous electrolyte. The positive or negative electrode contains, as its active material, a complex oxide comprising a material represented by the compositional formula MxTi1−xO2 and including an anatase-form crystal structure phase, wherein M is at least one metallic element selected from V, Mn, Fe, Co, Ni, Mo and Ir and x satisfies the relationship 0