NOVELTY - The material has carbonate ions arranged on a part of a material surface, where pH of the material is from 7.4 to 12.5 and measured when a specific material surface area is from 0.5 to 50 meter power 2 per gram or 3 to 30 meter power 2 per gram. Lithium carbonate is arranged on the material surface. A crystal structure of niobium composite oxide belongs to a monoclinic system, where a peak belonging to the carbonate ion is in a range of 1430 plus or minus 30 in an infrared reflectance spectrum with fourier transform infrared spectrophotometer (FT-IR).    USE - Active material for a battery e.g. nonaqueous electrolyte battery (claimed) such as flat type nonaqueous electrolyte battery e.g. lithium-ion secondary battery, for a two-or four-wheeled vehicle e.g. hybrid or electric two-to four-wheeled vehicle such as car, and assisting bicycle. Can also be used for a portable electronic device i.e. portable telephone.    ADVANTAGE - The material allows the lithium carbonate to be arranged on the part of the material surface, so that cycle charge/discharge efficiency can be dramatically improved and excellent charge/discharge characteristics can be realized. The material allows filling to be carried out to prevent generation of parts convexed or concaved from a standard level of a holder so as to properly determine peak positions. The material allows current collecting performance of a negative electrode layer to be improved when a ratio of a conductive agent is set to 2% or more by mass, so that a high-current characteristic of the nonaqueous electrolyte battery can be improved, while proving excellent charge/discharge cycle performance, thus improving energy efficiency of the vehicle.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a battery pack.    DESCRIPTION OF DRAWING(S) - The drawing shows an enlarged sectional view of a portion of a flat type nonaqueous electrolyte battery.    Baggy case (2)    Negative electrode (3)    Negative electrode current collector (3a)    Negative electrode layer (3b)    Separator (4)