TiO2/graphene sandwich paper as an anisotropic electrode for high rate lithium ion batteries.

We designed an anisotropic electrode, in which Li(+) ion insertion and diffusion are anisotropic, by controlled growth of TiO2 nanosheets parallel to the surface of graphene paper. The anisotropic electrode gives a gravimetric capacity of 112 mA h g(-1) at an ultra-high rate of 100 C (corresponding to 36 s of charge-discharge), 3 times higher than that of a referenced isotropic electrode. The results indicate that such an anisotropic electrode can be useful in the search for high-power lithium ion batteries.