Cs. Johnson et al., STABILIZED ALPHA-MNO2 ELECTRODES FOR RECHARGEABLE 3 V LITHIUM BATTERIES, Journal of the Electrochemical Society, 144(7), 1997, pp. 2279-2283
Manganese dioxide electrodes that have x-ray diffraction patterns char
acteristic of alpha-MnO2 (hollandite-type structure) and ramsdellite-M
nO2 have been evaluated in rechargeable 3 V lithium cells. Electrochem
ical data indicate that these electrodes (162 mAh/g, 10th cycle) provi
de superior performance to both single-phase pure alpha-MnO2 (136 mAh/
g, 10th cycle) and ramsdellite-MnO2 electrodes (113 mAh/g, 10th cycle)
, and comparable performance to lithia-stabilized alpha-MnO2 (0.15Li(2
)O . MnO2) electrodes (153 mAh/g, 10th cycle). Transmission electron m
icroscopy images and convergent-beam electron diffraction patterns sho
w that the MnO2 samples consist of grains of alpha-MnO2 grains of rams
dellite-MnO2, and grains of ''interconnected'' alpha-MnO2 and ramsdell
ite-MnO2 which exhibit a mutual crystallographic orientation. A search
is underway to find other interconnected MnO2 materials with even bet
ter cycling performance.