Are high pressure materials suitable for electrochemical applications?: HP-V2O5 as a novel electrode material for Li batteries

Under high pressure (40 kbar) V2O5 transforms into a layered polymorph, HP-V2O5, consisting of V5+O6 octahedra instead of V5+O5- square pyramids. HP-V2O5 reversibly intercalates up to 2 lithium ions down to 1 V vs. Li. The typical discharge/charge voltage-composition curve shows a step-like profile where six new Li,HP-V2O5 phases are detected. The specific capacity retention with cycling of HPV2O5 parallel to Li cells (250 Ah/Kg at a C/3.5 rate) is comparable to that of the ambient pressure polymorph. To our knowledge, HP-V2O5 is the first example of a high pressure material displaying such a good electrochemical performance. (c) 2007 Elsevier B.V. All rights reserved.