Co/CoTe heterostructure internal hairy fibers as high-efficiency oxygen electrocatalyst for Zn-air batteries

Abstract

The design of highly efficient catalysts to enhance the kinetics of oxygen reduction (OER) and oxygen evolution (ORR) reactions is the key issue for the development of high-performance Zn-air battery. In this work, we report the design of Co-CoTe heterostructured fibers as the bifunctional oxygen catalyst for Zn-air battery. Firstly, the theoretical analysis was carried out on Co-CoTe heterostructure. The large work function difference is favorable to construct strong interfacial built-in electric field (BIEF), and the low energy barrier endows high catalytic activities. Moreover, the in-situ grown carbon shell was designed to build “core–shell” Co-CoTe/C unit to realize its high performance. They assemble the Co-CoTe@HFS fiber with good self-supporting and flexible features. Taken the advantages of the strong BIEF, the “core–shell” basic unit, and the freestanding substrate, the Co-CoTe@HFS fiber achieves the good electrocatalytic properties and high reliability. The full Zn-air battery (ZAB) with the Co/CoTe@HFS air cathode achieves the high peak power density and cycling stability over long-term cycling. Therefore, this work provides a clue to design bifunctional oxygen catalysts for high-performance ZABs.