Nanostructured Anatase TiO2 - from Lithium- to Sodium-Ion Anodes

Abstract

Lithium-ion batteries are nowadays the energy storage device of choice for portable electronic devices due to their superior energy and power density. Consequently, they are considered also as most promising power source for large-scale applications as, for instance, electric vehicles [1–3]. However, for such applications further improvement of the existing technology is required in terms of energy, power, and particularly safety. Beside Li4Ti5O12, which is already used in commercial cells, anatase TiO2 – particularly in its nanostructured form - is seriously considered as alternative anode material to replace graphite due to its enhanced safety and rate capability [4,5].Remarkably, anatase TiO2 was recently demonstrated to be highly promising as high power anode material for sodium-ion batteries [6,7], which are considered as low-cost alternative for lithium-ion batteries. These batteries are especially interesting for stationary energy storage applications in order to balance the energy supply provided by renewables, for which size and weight are less important, while cost are of major importance.Herein we will report our latest results on the utilization of nanostructured anatase TiO2 for lithium- and sodium-ion batteries, including the importance of carbonaceous coatings and percolating networks, and highlight the major differences regarding the lithium- and sodium-ion storage mechanism.