The Structure and Electrochemical Performance of Na[sup +]-, K[sup +]-, and Ca[sup 2+]-Vanadium Oxide Nanotubes

Abstract

Vanadium oxide (VOx)(VOx) nanotubes, with embedded Na+­,Na+­, K+­,K+­, or Ca2+Ca2+ -ions, were synthesized and investigated structurally and electrochemically in a Li-battery context. The nanotubes consist of scroll-like layers of vanadium oxide separated by structure-directing primary amines or metal cations. X-ray diffraction and Raman spectroscopy provided structural information of the VOxVOx sheets. It was found that the structure within the layers is similar to the double-layered BaV7O16⋅nH2O.BaV7O16⋅nH2O. Galvanostatic measurements showed that the materials cycle reversibly for >100 cycles, giving average capacities of around 150 mAh/g (1.8-3.5 V vs. Li/Li+).Li/Li+). © 2003 The Electrochemical Society. All rights reserved.