High Capacity Li-O2 Cell and Electrochemical Impedance Spectroscopy Study

Investigations on Li-air cell have gained great interest in recent years. In the present work, Li-O-2 cells are fabricated with dual layer carbon electrodes consisting of an active layer and a diffusion layer employing a high surface area carbon. Discharge capacity measured at a current density of 0.18 mA cm(-2) is as high as 3100 mAh g(-1), which corresponds to 34 mAh cm(-2). Impedance spectra recorded during different stages of cell discharge suggest that the cell resistances increase gradually due to accumulation of reaction products of O-2 reduction, namely, Li2O2 and Li2O inside the pores of carbon electrode. (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3447867] All rights reserved.