Demystifying the Difference in Lithium and Sodium Insertion Electrochemistries in Anatase TiO_2

摘要

A fundamental question on the similarity or dissimilarity of lithium-ion and sodium-ion insertion electrochemistries is addressed considering anatase TiO_2 as a model electrode material. Although the physicochemical properties of lithium and sodium are identical, it is observed that their electrochemistries are quite different. It is summarized that the lithium ion insertion in anatase TiO_2 is diffusion controlled electrochemical process whereas sodium ion insertion is a surface mediated capacitive process.