Abstract: According to an embodiment, a nonaqueous electrolyte secondary battery including a positive electrode, a negative electrode containing a lithium titanium composite oxide having a spinel structure as a negative electrode active material, and a nonaqueous electrolyte, wherein the lithium titanium composite oxide that is the negative electrode active material has an average particle size based on a mass basis of 0.3 ?m or more but 0.9 ?m or less, and a lithium carbonate content rate of the negative electrode is 0.1% by mass or less per mass of the negative electrode active material, is provided.

Abstract: The disclosure describes a non-aqueous electrolyte battery with an improved cycle life. The non-aqueous electrolyte battery includes a positive electrode including a positive electrode layer, a negative electrode including a negative electrode layer, a separator disposed between the positive electrode and the negative electrode, and a non-aqueous electrolyte containing a lithium salt. The negative electrode layer may contain a negative electrode active material which can insert and release lithium ions at 0.4 V or more (V.S. Li/Li+). The lithium salt may contains LiPF6 with a concentration of less than 50% (including 0%).