Nonaqueous electrolyte battery and battery pack

A nonaqueous electrolyte battery comprising:

• a positive electrode comprising particles of a first positive electrode active material which is represented by general formula LiMSO4F, wherein M is at least one element selected from the group consisting of Fe, Mn and Zn and has a triplite type crystal structure, and particles of a second positive electrode active material which is represented by general formula LiM′SO4F (M′ is at least one kind of element selected from the group consisting of Fe, Mn and Zn) and has a tavorite type crystal structure;
• a negative electrode comprising a negative electrode active material comprising at least one selected from a group consisting of a lithium titanium oxide, a titanium oxide, a niobium titanium composite oxide and a carbon material;
• and
• a nonaqueous electrolyte,
• wherein a ratio of the first positive electrode active material to the total mass of the first positive electrode active material and the second positive electrode active material is from 10 mass % to 40 mass %.