||Increasing demand for sustainable energy has stimulated intense research on energy conversion and storage systems that are highly efficient, low cost, and excellent stability. A unitized regenerative fuel cell and metal air battery is a promising energy conversion system and energy storage system respectively. Bi-functional catalysts for both ORR and OER could be used in these systems to catalyze the process; therefore, a high-performance bi-functional catalyst is highly desirable for this application. Non-precious metals/metal oxides and graphene-based catalysts have been proposed and shown great promise in this application. However, it still remains a great challenge, up to now, to design and synthesize bi-functional catalysts for both ORR and OER with merits of high activity, low-cost, and excellent stability. In this research we proposed a Co-oxo-species anchored NCNT as a stable bifunctional oxygen catalyst.