Controlled synthesis of [email protected]@manganese oxides (MnO2, Mn3O4 and MnO) hierarchical hollow nanospheres and their superior lithium storage properties

We develop a facile approach to controlled-synthesize [email protected]@MnOx (MnO2, Mn3O4 and MnO) hierarchical hollow nanospheres by using [email protected] hollow nanospheres as the template. By simply adjusting the calcination temperature and time, three kinds of Fe3O4 @[email protected] (MnO2, Mn3O4 and MnO) hierarchical hollow nanospheres with different phase states of manganese oxides external layer are tailored. In virtue of the synergistic effect of Fe3O4 hollow nanostructures as supporters, the conductive carbon layer and MnOx external layer, the three hollow nanocomposites exhibit excellent lithium storage properties. At 0.1Ag(-1), [email protected]@MnO2, [email protected]@Mn3O4 and [email protected]@MnO hierarchical hollow nanospheres still have specific capacities of 708, 833 and 670mAhg(-1) after 150 cycles, respectively. Even at 0.5Ag(-1), the reversible capacity of the three hollow nanocomposites remains 609, 780 and 523mAhg(-1) after 500 cycles, respectively. Interestingly, [email protected]@Mn3O4 hierarchical hollow nanospheres possess more outstanding Li storage properties than [email protected]@MnO2 and [email protected]@MnO hierarchical hollow nanospheres because the former have more stable Mn 3 0 4 external layer during intensive cycles. The rational design of the phase state for [email protected]@MnOx (MnO2, Mn3O4 and MnO) hierarchical hollow nanospheres can provide a novel synthetic strategy for energy storage nanomaterials with optimized performances. (C) 2020 Elsevier Ltd. All rights reserved.