Enhanced efficiencies of lithium-air batteries using CNT/MnO2 nanocomposite cathodic materials

The rechargeable Li-O2 batteries have attracted a considerable interest because of their theoretical energy density which is higher than 11000 Wh/Kg [1,2]. The energy density of Li-O2 batteries is 5-10 times greater than those of lithium ion batteries [3,4]. This high energy density makes them a good candidate in totally electric cars, hybrid cars, and advanced electrical devices [5]. High theoretical energy density of this battery is due to the fact that the active cathodic material is not stored in battery and is supplied from air [6]. Thus, owing to the low weight of lithium metal, this battery is lighter compared to other electrode material based energy storage devices [7]. A CNT– 60% MnO2 nanocomposite was prepared and applied as the cathode material in the Li-O2 battery. The Electrochemical Impedance Spectroscopy (EIS) and discharge–charge cycles were also studied for all the cathodes fabricated using various CNT–MnO2 nanocomposites. The synthesized CNT–60% MnO2 compound had a capacity of about 4600 mA.h/gtotalcathode at a current density of 1000 mA/gtotalcathode. The battery fabricated using the optimum nanocatalyst revealed over-voltages equal to 0.20V and 0.87 V for discharge and charge, respectively, having a cycleability using the current density of 100 mA/gtotalcathode.