Rate capabilities and specific energies of Li/MnO/sub 2/ and Li/Li/sub x/CoO/sub 2/ AA cells

Abstract

Rechargeable lithium battery chemistries are being evaluated for low power underwater vehicle applications. Testing of AA size cells has been completed for Moli Energy's lithium/manganese dioxide (MnO/sub 2/) and Alliant Techsystems' first embodiment of the lithium/lithium cobalt oxide (Li/Li/sub x/CoO/sub 2/) system in the AA size. Cells were cycled at various discharge rates, temperatures, and depths of discharge. At 25 degrees C and 5 mA/cm/sup 2/, delivered energy densities were about 30 Wh/lb for Li/MnO/sub 2/ cycled over 0.375 F/mol. Li/Li/sub x/CoO/sub 2/ cells cycled under the same conditions delivered an equivalent energy density. When Li/Li/sub x/CoO/sub 2/ cells were cycled to utilize 0.5 and 0.75 F/mol, energy densities of 40 Wh/lb and 60 Wh/lb, respectively, were demonstrated.<>