Cyclability of a Lithium-Oxygen Battery Containing N-Methyl-2-Pyrrolidone and a Vertically Aligned Carbon Nanotube Cathode

The lithium-air battery has a high specific capacity but suffers from a poor cyclability. The reason for its poor cycle life is still unclear and many explanations, such as the degradation of the solvent, the lithium salt, and the carbon cathode, have been suggested. Although N-methyl-2-pyrrolidone (NMP) was shown to be stable under superoxide anion radical conditions in stand-alone tests, lithium-air cells containing NMP still showed a very low reversibility in previous work. Here, a freestanding vertically aligned carbon nanotube is used as a binder-free electrode in a lithium-air battery cathode, and the results indicate that the cyclability of the cell is significantly improved. This research proves that the content of the carbon electrode is of pivotal importance for the stability of lithium-air batteries.