Table of Contents
ISRN Electrochemistry
Volume 2014, Article ID 359019, 12 pages
http://dx.doi.org/10.1155/2014/359019
Research Article

Enhanced Structural Integrity and Electrochemical Performance of AlPO4-Coated MoO2 Anode Material for Lithium-Ion Batteries

1Institute of Functional Nanomaterials, University of Puerto Rico, Rio Piedras Campus, San Juan, PR 00931-3334, USA
2Department of Physics, University of Puerto Rico-Rio Piedras Campus, San Juan, PR 00936-8377, USA
3Center for Advanced Nanoscale Materials, University Research Center, University of Puerto Rico-Rio Piedras Campus, San Juan, PR 00931-3346, USA
4Department of Chemistry, University of Puerto Rico, Rio Piedras Campus, San Juan, PR 00931-3346, USA

Received 24 December 2013; Accepted 15 January 2014; Published 4 March 2014

Academic Editors: S.-M. Lee and E. Vallés

Copyright © 2014 José I. López-Pérez et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

AlPO4 nanoparticles were synthesized via chemical deposition method and used for the surface modification of MoO2 to improve its structural stability and electrochemical performance. Structure and surface morphology of pristine and AlPO4-coated MoO2 anode material were characterized by electron microscopy imaging (SEM and TEM) and X-ray diffraction (XRD). AlPO4 nanoparticles were observed, covering the surface of MoO2. Surface analyses show that the synthesized AlPO4 is amorphous, and the surface modification with AlPO4 does not result in a distortion of the lattice structure of MoO2. The electrochemical properties of pristine and AlPO4-coated MoO2 were characterized in the voltage range of 0.01–2.5 V versus Li/Li+. Cyclic voltammetry studies indicate that the improvement in electrochemical performance of the AlPO4-coated anode material was attributed to the stabilization of the lattice structure during lithiation. Galvanostatic charge/discharge and electrochemical impedance spectroscopy (EIS) studies reveal that the AlPO4 nanoparticle coating improves the rate capability and cycle stability and contributes toward decreasing surface layer and charge-transfer resistances. These results suggest that surface modification with AlPO4 nanoparticles suppresses the elimination of oxygen vacancies in the lattice structure during cycling, leading to a better rate performance and cycle life.