摘要 |
The present invention provides a manganese bismuth mixed metal oxide cathode material through a solid-state reaction between manganese dioxide, and either bismuth or a bismuth compound in a compound having the general formula MnO<SUB>y</SUB>(Bi<SUB>2</SUB>O<SUB>3</SUB>)<SUB>x</SUB>, which affords charge transfer catalytic behavior that allows the cathode to be fully reversible at suppressed charge potentials and increased discharge potentials. The MnO<SUB>y</SUB>(Bi<SUB>2</SUB>O<SUB>3</SUB>)<SUB>x </SUB>cathode material may be incorporated into an electrochemical cell with either a lithium metal or lithium ion anode and an organic electrolyte. The present invention provides a compound with the general formula MnO<SUB>y</SUB>(Bi<SUB>2</SUB>O<SUB>3</SUB>)<SUB>x</SUB>, where subscript x is between 0.05 and 0.25, subscript y is about 2 and the overcharge protection is not needed as the subscript z approaches 0.0. In the preferred embodiment, a cathode material where subscript x is between 0.05 and 0.135 with the formula MnO<SUB>2</SUB>(Bi<SUB>2</SUB>O<SUB>3</SUB>)<SUB>0.12 </SUB>provides the much-needed full reversibility, high voltage stability and reduced charge transfer impedance. A manganese bismuth mixed metal oxide cathode for an lithium electrochemical system, a lithium electrochemical system and a rechargeable lithium battery employing the same compound with the general formula MnO<SUB>y</SUB>(Bi<SUB>2</SUB>O<SUB>3</SUB>)<SUB>x </SUB>and methods for making manganese bismuth mixed metal oxide cathode material for lithium electrochemical devices having the general formula MnO<SUB>y</SUB>(Bi<SUB>2</SUB>O<SUB>3</SUB>)<SUB>x </SUB>are also provided.
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