This is why – they say – it is crucial to design oxygen catalysts with well-defined shapes and high-activity crystal facets that can effectively regulate the oxygen reduction reaction and the oxygen evolution reaction at the three-phase interfaces. The problem is that this process remains challenging.
Through their testing, the researchers noticed that the Mn3O4 NS/G with the facets (101) and enriched oxygen vacancies offered a lower charge overpotential of 0.86 V than that of Mn3O4 nanoparticles on graphene (1.15 V).
Moreover, the Mn3O4 NS/G cathode exhibited long-term stability over 1,300 hours and ultrahigh specific capacity up to 35,583 mAh/g at 200 mA/g, outperforming most Mn-based oxides for Li-O2 batteries previously studied.
“This work may provide clues for engineering Mn-based materials with a defined crystal facet for high-performance Li-O2 batteries,” Wu Zhongshuai, co-lead author of the research, said in a media statement.