Negative electrode active material for nonaqueous electrolyte battery, method of producing the same, nonaqueous electrolyte battery and battery pack

摘要

According to one embodiment, a negative electrode active material for nonaqueous electrolyte battery includes a titanium oxide compound having a crystal structure of monoclinic titanium dioxide. When a monoclinic titanium dioxide is used as the active material, the effective capacity is significantly lower than the theoretical capacity though the theoretical capacity was about 330 mAh/g. The invention comprises a titanium oxide compound which has a crystal structure of monoclinic titanium dioxide and a (001) plane spacing of 6.22 Å or more in the powder X-ray diffraction method using a Cu—Kα radiation source, thereby making an attempt to improve effective capacity.

主权项

1. A titanium oxide compound having a crystal structure of a monoclinic titanium dioxide and satisfying the following equation (I):
d001≧6.223 Å  (I) wherein d001 is the spacing of the (001) plane which is measured by the powder X-ray diffraction method using a Cu—Kα radiation source, and wherein the titanium oxide compound has a crystal structure which belongs to the space group C2/m, the titanium oxide compound is suitable as an active material in a negative electrode of a nonaqueous electrolyte battery, the titanium oxide compound has a particle form the titanium oxide compound has a BET specific surface area in the range of 6 to 200 m2/g; and the titanium compound satisfies the following equation (II):
0.39≦I(200)/I(001)≦0.5   (II) wherein I(001) is the peak intensity of the (001) plane and I(200) is the peak intensity of the (200) plane, which are measured by the powder X-ray diffraction method using a Cu—Kα radiation source.