Electrochemical evaluation of carbon nanotubes and carbon black for the cathode of Li–air batteries

Cyclic Voltammetry (CV) was used to screen carbon catalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) performance as electrodes for the Li–air battery. Lithium bis(trifluoromethylsulfonyl)imide (LiTF2N) in tetraethylene glycol dimethyl ether (TEGDME) was used as the electrolyte during testing. The effect of manganese/manganese oxide addition on the performance of the carbons was compared to that of the bare carbons in a cycling study. From CV results, it was found that single walled carbon nanotubes (SWCNT) had the highest peak current density per gram for ORR and OER than the other types of carbon studied. The SWCNT ORR peak decreased 49% after 100 cycles and only 36% when manganese/manganese oxide was added. The high activity of SWCNT with manganese/manganese oxide spheres make it a desirable material to use as the cathode for Li–air batteries. •Demonstrates the role of carbon on ORR and OER kinetics for Li/air batteries.•SWCNT had the highest peak current density per gram for ORR and OER.•SWCNT has a similar onset potential than Au and higher performance.