Investigation of Yttrium and Polyvalent Ion Intercalation into Nanocrystalline Vanadium Oxide

The electrochemical reactivity of cations such as and into crystalline materials was investigated. The ionic diffusion constant of and into microcrystalline and nanocrystalline was measured by the galvanostatic intermittent titration technique. The ion diffusion constant into a 500 nm crystalline was found to be approximately two orders of magnitude lower than for the ion. In order to enable practical intercalation of a nanocrystalline was fabricated through a combustion flame synthesis technique. For the first time, reversible electrochemical intercalation of into a host structure was shown to be feasible. An asymmetric hybrid cell configuration was utilized in order to provide a reversible counter electrode during intercalation. Preliminary data indicates can be reversibly intercalated into with apparent gravimetric capacities exceeding that of or over the limited voltage range of 2.5 to 4.2 V The concept of polyvalent intercalation is discussed relative to intercalation, pseudocapacitance, apparent specific capacity, and practical energy storage systems. © 2001 Telcordia Technologies. All rights reserved.