DFT study of lithium battery materials: application to the beta-VOXO4 systems (X = P, As, S)

摘要

VOXO4 systems have been considered as potential lithium battery electrodes. They mainly present two distinct structural types: the tetragonal "alpha" type with a two-dimensional framework, and the three-dimensional orthorhombic "beta". DFT calculations were performed on this latter system for several beta-LixVOXO4 compounds (x = 0, 1; X = P As, S). They allowed to propose structural models for VOAsG(4) and LiVOSO4, not fully crystallographically well described yet. Based on an experimental model of two-phase processes, these calculations led also to a good simulation of electrochemical potential values. A density of states analysis put in evidence the "inductive effect" and the role played by (XO4)(n-) groups inside the host frameworks on these potentials. (C) 2003 Elsevier Inc. All rights reserved. [References: 62]