Interfacial Engineering of Co 3 O 4 /Fe 2 O 3 Nano-Heterostructure Toward Superior Li-O 2 Batteries.

A major issue with Li-O 2 batteries is their slow oxygen reduction and evolution kinetics, necessitating catalysts with high catalytic activity to improve reaction kinetics and cycle stability. Herein, a nano-heterostructured catalyst composed of Co 3 O 4 and Fe 2 O 3 (Co 3 O 4 /Fe 2 O 3 ) with a porous rod morphology is achieved through an interfacial engineering strategy by constructing Fe 2 O 3 on the Co 3 O 4 surface, which can function as a high-performance cathode in order to efficiently encourage the oxygen reduction and evolution while also reduce the battery polarization during charging and discharging. The density functional theory (DFT) calculations show the differences in charge density at the interface of nano-heterostructures, demonstrating the occurrence of an electron transfer process in the interface region of Co 3 O 4 and Fe 2 O 3 , implying a strong electronic coupling transfer, and in turn changing the electronic structure of the Co 3 O 4 . This significantly reduces the adsorption energy of LiO 2 intermediates, thereby effectively lowering the overpotential. The resultant Li-O 2 battery has larger discharge specific capacity, lower overpotential for the efficient oxygen evolution/reduction, as well as good cycling stability of 280 cycles. This work demonstrates an effective method to fabricate the nano-heterostrucutred materials with enhanced catalytic efficiency for advanced energy applications.