1 research outputs found
Two-Dimensional Mn<sub>3</sub>O<sub>4</sub> Nanosheets with Dominant (101) Crystal Planes on Graphene as Efficient Oxygen Catalysts for Ultrahigh Capacity and Long-Life Li–O<sub>2</sub> Batteries
Designing oxygen catalysts with well-defined shapes and
high-activity
crystal facets is of great importance to boost catalytic performance
of Li–O2 batteries but challenging. Herein, we report
the facet engineering of an ultrathin Mn3O4 nanosheet
(NS) with dominant (101) crystal planes on graphene (Mn3O4 NS/G) as efficient and durable oxygen catalysts for
high-performance Li–O2 batteries with ultrahigh
capacity and long-term stability. Notably, the Mn3O4 NS/G with the (101) facets and enriched oxygen vacancies
offers a lower charge overpotential of 0.86 V than that of Mn3O4 nanoparticles on graphene (1.15 V). Further,
the Mn3O4 NS/G cathode exhibits a long-term
stability over 1300 h and an ultrahigh specific capacity up to 35,583
mAh g–1 at 200 mA g–1, outperforming
most Mn-based oxides for Li–O2 batteries reported.
Both the experimental and theoretical results prove the lower adsorption
energy of Mn3O4 (101) for Li2O2 in comparison with Mn3O4 (211), manifesting
the easier decomposition of Li2O2 during the
charging process. This work will open many opportunities to engineer
Mn-based materials with a defined crystal facet for high-performance
Li–O2 batteries