US 6,982,048 B1
Potassium stabilized manganese dioxide for lithium rechargeable batteries
Terrill B. Atwater, North Plainfield, N.J. (US); and Alvin J. Salkind, Princeton, N.J. (US)
Assigned to The United States of America as represented by the Secretary of the Army, Washington, D.C. (US)
Filed on May 04, 2004, as Appl. No. 10/843,635.
Application 10/843635 is a division of application No. 09/954294, filed on Sep. 11, 2001, granted, now 6,770,398.
Int. Cl. H01M 4/50 (2006.01); H01M 4/58 (2006.01); C01G 45/12 (2006.01)
U.S. Cl. 252—518.1 19 Claims
OG exemplary drawing
 
1. 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
LixKyMnO2, 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 Li0.375K0.125MnO2;
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.