Cathode reaction mechanism on the h-BN/Ni (111) heterostructure for the lithium-oxygen battery

Abstract

In this study, the heterostructure of h-BN and Ni (111) is adopted as effective cathode catalysts for the Li–O2 battery using first-principles calculations. It was determined that h-BN/Ni (111) thermodynamically prefers a 2e− pathway despite the large adsorption energy of O2, even larger than Pt (111), and dissociation of O2 at the formation of the oxygen reduction reaction (ORR) intermediates of the Li–O2 battery on h-BN/Ni (111). In this respect, the result of h-BN/Ni (111) does not accord with previous studies that found that strong adsorption and dissociation of O2 indicate a reaction to proceed via the 4e− pathway. The reason for this behavior is identified as being adsorption of the ORR intermediates mainly conducted by strong ionic bonds between the B atoms of h-BN and the O atoms of the intermediates, while the Li atoms do not participate in the bonds. The electrochemical performance of h-BN/Ni (111) is remarkable with a maximum discharge potential of 1.93 V and a minimum charge potential of 3.83 V, comparable to noble metal based catalysts.