Reaction of SbPO4 with lithium in non-aqueous electrochemical cells: preliminary study and evaluation of its electrochemical performance in anodes for lithium ion batteries

摘要

SbPO4 a phosphate with a layered structure, was tested as an electrode material for lithium cells spanning the 3.0-0.0 V range. Two main electrochemical processes were detected as extensive plateaus at ca. 1.6 and 0.7 V in galvanostatic measurements. The first process was found to be irreversible, thus excluding a potential intercalation-like mechanism for the reaction and being better interpreted as a decomposition reaction leading to the formation of elemental Sb. This precludes the use of this compound as a cathodic material for lithium cells. By contrast, the process at 0.7 V is reversible and can be ascribed to the formation of lithium-antimony alloys. The best electrochemical response was obtained by cycling the cell at a C/20 discharge rate over the voltage range 1.25-0.25V. Under these conditions, the cell delivers an average capacity of 165 Ah/kg-a value greater than those reported for other phosphates-upon successive cycling. (C) 2004 Published by Elsevier Inc.