Li2CoSiO4 has been prepared successfully by a solution route or hydrothermal reaction for the first time, and its electrochemical performance has been investigated primarily. Reversible extraction and insertion of lithium from and into LiCoSiO4 at 4.1 V versus lithium have shown that this material is a potential candidate for the cathode in lithium ion batteries. At this stage reversible electrochemical extraction was limited to 0.46 lithium per formula unit for the Li2CoSiO4/C Composite materials, with a charge capacity of 234 mAh g(-1) and a discharge capacity of 75 mAh g(-1). (C) 2007 Published by Elsevier B.V.