Does Pseudocapactive Charge Storage Take Place in Nanoparticulate TiO2 and Li4Ti5O12 Anodes?

Tuesday, 26 May 2015: 14:40
Salon A-5 (Hilton Chicago)
M. Opitz (Philipps-Universitaet Marburg), J. Yue (Justus Liebig University Giessen), J. Wallauer (Philipps-Universitaet Marburg), B. Smarsly (Justus Liebig University Giessen), and B. Roling (Philipps-Universitaet Marburg)
Titanium oxide-based materials, such as TiO2 and Li4Ti5O12 (LTO), are considered as interesting alternative anode materials for lithium ion batteries. In order to increase the interfacial area between TiO2 particles and the battery electrolyte and in order to reduce the diffusion length for Li+ ions within the particles, both materials have been extensively studied. [1], [2] Thereby, indication has been found that the charge storage is not entirely due diffusion-controlled Faradaic charge storage, but also due to pseudocapacitive charge storage. [3], [4]

We studied nanoparticlate LTO electrodes and compared this to Li storage in Nb-doped TiO2 particles. Using scan rate-dependent cyclic voltammetry, we determined the amount of Faradaic and of pseudocapactive charge with the same method that was reported in the literature [1], [4]. Thereby, we discovered that the application of this method leads to unphysical results, which is originated in the iso-potential plots of the scan-rate dependent current density. We show that even for simple prototype Faradaic reactions, such iso-potential plots yield an apparent pseudocapacitance.


[1]   J. Wang, J. Polleux, J. Lim, B. Dunn, J. Phys. Chem. C 111 (2007) 14925–14931.

[2]   D. Wang, X. Wu, Y. Zhang, J. Wang, P. Yan, C. Zhang, D. He, Ceramics International 40 (2014) 3799–3804.

[3]   T. Brezesinski, J. Wang, J. Polleux, B. Dunn, S.H. Tolbert, Journal of the American Chemical Society 131 (2009) 1802–1809.

[4]   P. Yu, C. Li, X. Guo, J. Phys. Chem. C 118 (2014) 10616–10624.