Here we demonstrate the use of polymer derived activated carbons as the potential electrode material for Li/O-2 batteries. The activated carbons were synthesized by sol-gel polycondensation of low cost phenol and formaldehyde followed by carbonization at 1050 degrees C in an inert atmosphere and activation under CO2 to different degrees of burn off. Galvanostatic charge/discharge measurements performed on the activated carbon based electrodes show that discharge capacity increases with mesopore volume, with the highest discharge capacity of 1852 mAh/g obtained for the carbon having the highest mesopore volume of 1.8717 cm(3)/g. Galvanostatic rate capability tests show that discharge capacity of the cell decreases with increasing discharge rates significantly. (C) 2012 The Electrochemical Society. [DOI: 10.1149/2.089203jes] All rights reserved.