| Popis: |
Testing of AA size rechargeable cells for underwater vehicle and other naval applications is complete for AT&T's lithium/niobium triselenide (Li/NbSe/sub 3/) and Moli Energy's lithium/molybdenum disulfide (Li/MoS/sub 2/) and is in progress on Moli Energy's lithium/manganese dioxide (Li/MnO/sub 2/) and W.R. Grace's lithium/titanium disulfide (Li/TiS/sub 2/). Cell cycling was performed at various discharge rates, temperatures, and depths of discharge. At 25 degrees C and 1 mA/cm/sup 2/ (roughly the C/4 rate), delivered energy densities were about 40 Wh/lb for NbSe/sub 3/, TiS/sub 2/, and MnO/sub 2/ and 22 Wh/lb for MoS/sub 2/. Under the same conditions, nickel/cadmium (Ni/Cd) cells deliver only 10 Wh/lb. However Ni/Cd cycles much longer and the lithium cells are far more vulnerable than Ni/Cd to performance loss in low temperature, high discharge rate cycling. The NbSe/sub 3/ data and the (limited) TiS/sub 2/ data indicate that these cells tend to accept excessive charge which is often associated with lithium dendrite shorting and considered potentially hazardous. At 1 mA/cm/sup 2/ and 25 degrees C, discharge plateaus ranged from 2.9 V for MnO/sub 2/ to 1.8 V for MoS/sub 2/. > |
