Pseudocapacitive Lithium Storage in TiO2(B)

Phase-pure TiO 2 (B) with microfibrous morphology was prepared via a newly developed method from amorphous TiO 2 . Cyclic voltammetry evidences that Li-insertion into TiO 2 (B) is governed by a pseudocapacitive faradaic process, whose rate is not limited by solid-state diffusion of Li + in a broad interval of scan rates. This unusual behavior was discussed in terms of the crystal structure of the TiO 2 (B) host, having freely accessible parallel channels for Li + -transport perpendicular to the (010) face. The characteristic Li-insertion electrochemistry of TiO 2 (B) allows re-interpretation of several previous reports, which did not consider explicitly this relation or the presence of TiO 2 (B) in various TiO 2 materials of different origin.