Abstract:
According to one embodiment, there is provided a composite. The composite includes a graphene sheet material, active material particles, and a carbon layer located between the graphene sheet material and the active material particles. The graphene sheet material includes at least one of a planar graphene sheet of a monoatomic layer and a laminate of 10 layers or less of the planar graphene sheets. The active material particles include a titanium-niobium composite oxide. The carbon layer includes a carbon material having a n-electron system.
Abstract:
According to one embodiment, there is provided an active substance. The active substance includes particles of niobium titanium composite oxide and a phase including a carbon material. The niobium titanium composite oxide is represented by Ti1-xM1xNb2-yM2yO7. The phase is formed on at least a part of the surface of the particles. The carbon material shows, in a Raman chart obtained by Raman spectrometry, a G band observed at from 1530 to 1630 cm−1 and a D band observed at from 1280 to 1380 cm−1. A ratio IG/ID between a peak intensity IG of the G band and a peak intensity ID of the D band is from 0.8 to 1.2.
Abstract:
According to one embodiment, an active material containing a niobium titanium composite oxide is provided. The niobium titanium composite oxide has average composition represented by LiyNb2+xTi1−xO7+0.5x (0≦x≦0.5, 0≦y≦5.5). The niobium titanium composite oxide satisfies peak intensity ratios represented by the following formulae (1) to (3): 0.05≦(B/A)≦0.7 (1) 0.01≦(C/A)≦0.2 (2) 0≦(D/A)≦0.1 (3)