| 摘要 |
According to an embodiment, an active substance is provided. The active substance comprises niobium titanium composite oxide particles; and a phase including a carbon material. The niobium titanium composite oxide is represented by chemical formula Ti_(1-x)M1_xNb_(2-y)M2_yO_7. The phase is formed on at least part of the surfaces of the particles. The carbon material exhibits a G band, which is observed in the range of 1530 to 1630 cm^-1, and a D band, which is observed in the range of 1280 to 1380 cm^-1, in a Raman chart obtained by Raman spectroscopy. The ratio I_G/I_D, which is the ratio of I_G, i.e., the peak intensity of the G band to I_D, i.e., the peak intensity of the D band, ranges from 0.8 to 1.2. |
