Patent ID: 6982048

Claim:
A method for making a cathode material for a lithium electrochemical system, comprising the steps of: drying a manganese oxide and a potassium additive; forming a first mixture by mixing said manganese oxide and said potassium additive; forming an intermediate compound by heat-treating said first mixture; forming a potassium-manganese mixed metal oxide; heat-treating said potassium-manganese mixed metal oxide; providing said potassium-manganese mixed metal oxide with the general formula Li x K y MnO 2 , where y< 0.5 and x+y< 1.0, and a reversible region where 0.0 <x< 1.0 −y; said potassium-manganese mixed metal oxide being Li 0.375 K 0.125 MnO 2 ; preventing a phase change in a cathode; providing an initial specific capacity of about 130 mAhrs/g in said cathode; and permitting said cathode to be fully reversible.