| abstract |
An active material having a high capacity, a large current discharge performance and an excellent cycle life performance, and a nonaqueous electrolyte battery and a battery pack using the active material are provided. According to an embodiment, an active material including monoclinic niobium titanium composite oxide particles and a carbon material layer is provided. Monoclinic niobium titanium composite oxide particles can occlude and release Li ions or Na ions and satisfy the following formula (1). The carbon material layer covers at least a part of the surface of the niobium titanium composite oxide particles and satisfies the following formula (2). 0.5≰ (α / β) ≰2 (1) 0≰ (γ / σ) ≰0.1 (2) where α is the number of moles of Nb in the niobium titanium composite oxide particles and β is the niobium titanium composite oxide The number of moles of Ti in the particles, γ is the number of hydrogen atoms in the carbon material layer, and σ is the number of carbon atoms in the carbon material layer. [Selection figure] None |