A novel Co(phen) 2/C catalyst for the oxygen electrode in rechargeable lithium air batteries

Abstract

A novel Co(phen) 2/C catalyst was prepared by coating cobalt(II) phenanthroline (phen) chelate on BP2000 carbon black and then heat treating in an inert atmosphere. The obtained Co(phen) 2/C product with 1. 0 wt% cobalt loading exhibits similar morphology and porosity characteristics to those of the bare BP2000. X-ray diffraction measurements demonstrate a face-centered cubic (fcc) α-Co phase embedded in the carbon support after pyrolysis. Charge/discharge tests of the lithium-oxygen cells using the prepared Co(phen) 2/C catalyst show high discharge capacities of 4870 mAh g -1 (0. 05 mA cm -2), 3353 mAh g -1 (0. 1 mA cm -2) and 3220 mAh g -1 (0. 15 mA cm -2), respectively. The Co(phen) 2/C cathode exhibits reasonable reversibility with capacity retention of 1401 mAh g -1 (0. 1 mA cm -2) after 10 cycles. The superior electrochemical performance of the prepared Co(phen) 2/C catalyst and low cost of the phenanthroline chelating agent indicate that Co(phen) 2/C is a promising cheap catalyst for lithium-air batteries. © 2012 The Author(s).