A HIGH-PERFORMANCE LIXMNOY CATHODE MATERIAL FOR RECHARGEABLE LITHIUM CELLS

Lithiated alpha-MnO2 has been synthetized and used as cathode material for rechargeable lithium cells. Coin cells have been used to test the material cycleability and characteristics with 1 M LiCF3SO3/PC-EC-DME electrolyte. Reversible capacity has been demonstrated for 130 cycles with 160 A h/kg with 3.6 to 2 V cycling cutoff voltages without important capacity loss. Pilot industrial batches have been used to realize prototype 'C'-size cells; their cycling leads to performances as high as 200 A h/kg of Li(x)MnO(y) (alpha) in the first cycles corresponding to 2.4 A h for a cell capacity with discharge voltage of 2.87 V. To date, 60 cycles have been achieved with an anode excess of 2.6, which corresponds to a lithium cycling efficiency >95%.