Nanostructured Diamond Like Carbon Thin Film Electrodes for Lithium Air Batteries

Nanostructured diamond like carbon (DLC) thin films were fabricated by radio frequency sputtering and their electrochemical behavior as air electrodes for Li-air batteries were investigated for the first time. These nanostructured DLC air cathodes presented high discharge plateaus around 2.7 V and large reversible capacities around 2318 mAh/g at the current rate of 220 mA/g. The reaction mechanism of DLC thin film electrodes of lithium air cells was revealed by ex situ Raman, Fourier transform infrared (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and selected area electron diffraction (SAED) measurements. The formation of nanocrystalline Li2O2 and amorphous Li2CO3 was confirmed in the discharge products. Our results have demonstrated that DLC thin films with sp(3)-bonded carbon atoms due to their good cyclic performance and low polarization between discharging and charging profiles exhibit a promising candidate of air electrode materials for future lithium air batteries. (C) 2011 The Electrochemical Society. [DOI: 10.1149/1.3623431] All rights reserved.