Nonaqueous electrolyte battery and battery pack

摘要

According to one embodiment, there is provided a nonaqueous electrolyte battery including a positive electrode, a negative electrode, and a nonaqueous electrolyte. The negative electrode includes a first negative electrode active material containing a monoclinic β-type titanium composite oxide and a second negative electrode active material. The second negative electrode active material causes insertion and release of lithium ion in a potential range from 0.8 V to 1.5 V (vs. Li/Li+).

主权项

1. A nonaqueous electrolyte battery comprising:
a positive electrode; a negative electrode; and a nonaqueous electrolyte; wherein the capacity per unit area of the negative electrode is larger than that of the positive electrode, wherein the negative electrode comprises a first negative electrode active material comprising a monoclinic β-type titanium composite oxide and a second negative electrode active material, the second negative electrode active material causing insertion and release of lithium ion in a potential range from 0.8 V to 1.5 V relative to metallic lithium, wherein a ratio AB of a mass A of the first negative electrode active material to a mass B of the second negative electrode active material is in a range from 1 to 20, and wherein the second negative electrode active material is selected from: a transition metal-containing oxide selected from the group consisting of a titanium-containing oxide having a crystal structure belonging to a space group Cmca and an oxide containing one or more elements of Fe, Co, Ni, Cu, or Mo, and a titanium-containing oxide represented by a formula of Li2+xAyTi6O14, wherein A represents at least one element selected from the group consisting of Na, K, Mg, Ca, Ba, and Sr, and x and y satisfy relationships represented by inequalities of 0≦x≦5 and 1≦y≦2, respectively.