Interface engineering of NiCo2O4/BCN nanotube for performance enhancement of lithium-oxygen battery

The cathode oxygen catalyst is the key component of Li-O-2 battery. In this research, a composite of NiCo2O4 nanoparticles on BCN Nanotube is synthesized via a facile hydrothermal approach, and used as the bi-functional electrocatalyst for the oxygen reduction and evolution reactions in aprotic rechargeable Li-O-2 batteries. The asassembled Li-O-2 battery exhibits a low overpotential of 0.96 V, a high discharge capacity of 9823 mA h g(-1) and more importantly a remarkable cycling stability over 320 cycles under the controlled capacity of 1000 mA h g(-1). DFT calculations analyze the catalytic mechanism. It is found that the composite catalyst has an enhanced charge transfer at the interface between NiCo2O4 and BCN, which increases the electron conductivity and the activity site density of the catalyst, and thereby facilitates the reversible formation and decomposition of Li2O2 as well as the cycling of the battery. The electronic interface interaction presents an effective strategy for designing composite oxygen catalysts for high performance Li-O-2 batteries.