Lithium-vanadium phosphates, method of preparation and lithium ion batteries using same

The invention provides an electrochemical cell which comprises a first electrode and a second electrode which is a counter electrode to said first electrode. The first electrode comprises a phosphorous compound of the nominal general formula LiE'E"(PO), desirably at least one E is a metal; and preferably, LiM'M"(PO). E' and E" are the same or different from one another. Where E' and E" are the same, they are preferably metals having more than one oxidation state. Where E' and E" are different from one another, they are preferably selected from the group of metals where at least one of E' and E" has more than one oxidation state.