Inverse-direction Growth of TiO2 Microcones by Subsequent Anodization in HClO4 for Increased Performance of Lithium-Ion Batteries

초록

The effect of second anodization on anodically fabricated TiO2 microcones is investigated with the aim of enhancing the lithium-ion battery performances; these microcones are treated with a trace concentration of an electrolyte of HClO4. Unlike in the case of second anodization in H2SO4 or H3PO4, which leads to breakdown of the structures of the microcones, the HClO4-treated TiO2 microcones maintain their unique morphological crystalline structures; this enables the inverse growth of an oxide layer. Particularly, protruding nanoparticles provide a large surface area and thus a higher areal capacity, wherein lithium ions can be stored; these particles are formed on the back-hemisphere layers of the microcones with an increase in the overall thickness of the barrier oxide layer. The HClO4-treated TiO2 microcones exhibit an areal capacity of approximately 1.6 times than that of pristine TiO2 microcones as well as an excellent cycling stability and capacity retention.

키워드