Patent ID: 8647774

Claim:
An active material, comprising a titanium composite oxide, wherein: the titanium composite oxide comprises a monoclinic β-type titanium composite oxide as a main phase, such that when an integral intensity of a main peak of the monoclinic β-type titanium composite oxide obtained with a wideangle X-ray diffraction method having a CuKα-ray as an X-ray source is 100, a relative value of an integral intensity of a main peak that presents the range of 2θ=25.1 to 25.5° attributed to a sub-phase of H 2 Ti 8 O 17 is 30 or less, the main peak being an X-ray diffraction peak of the plane (110) in the monoclinic β-type titanium composite oxide; and the titanium composite oxide has a crystallite diameter of 5 nm or more as calculated from the main peak of the monoclinic β-type titanium composite oxide obtained with the wideangle X-ray diffraction method.