Nonaqueous electrolyte battery and battery pack

A nonaqueous electrolyte battery comprising:

• a negative electrode comprising a negative electrode current collector and a negative electrode active material-containing layer provided on the negative electrode current collector, the negative electrode active material-containing layer comprising a negative electrode active material comprising an orthorhombic Na-containing niobium titanium composite oxide, the orthorhombic Na-containing niobium titanium composite oxide being represented by a general formula of Li2+vNa2-yM1xTi6-y-zNbyM2zO14+δ, wherein M1 is at least one selected from the group consisting of Cs, K, Sr, Ba and Ca, M2 is at least one selected from the group consisting of Zr, Sn, V, Ta, Mo, W, Fe, Co, Mn and Al, and 0≤v<2, 0≤x<2, 0.1≤y≤0.8, 0≤z<3, and −0.5≤δ≤0.5;
• a positive electrode comprising a positive electrode current collector and a positive electrode active material-containing layer provided on the positive electrode current collector, the positive electrode active material-containing layer comprising a positive electrode active material;
• and
• a nonaqueous electrolyte,
• wherein a mass C [g/m2] of the positive electrode active material per unit area of the positive electrode and a mass A [g/m2] of the negative electrode active material per unit area of the negative electrode satisfy the following formula (1):
• 0.95<A/C<1.5 (1).