Improvement of the electrochemical performance of LiCoPO45Vmaterial using a novel synthesis procedure

A LiCoPO4 cathode material with, to our knowledge, the highest discharge capacity (125 mAh/g) is reported. The phosphate is obtained by using a novel solid-state synthesis procedure. The basic idea of the novel synthesis procedure is the use of an alternative cobalt-containing precursor (CoNH4PO4) and a lithium excess synthesis with carbon black as temporal dispersing agent, later eliminated as CO2. The carbon black addition produces lower average particle size than conventional preparations, yielding a finely dispersed solid. The low particle size is responsible for a better electrochemical behavior. Finally the effects of scan rate and potential window on the electrochemical performance are discussed. (C) 2002 The Electrochemical Society.