Designing nanostructured metal oxides (MOs) is a particularly effective approach to enhance their lithium storage properties. However, it is difficult to synthesize MOs with various nanostructures by a facile strategy. Herein, based on the Kirkendall effect, the yolk-shell, hollow, and hierarchical Fe0.8Mn1.2O3 sub-micropolyhedrons are produced by briefly adjusting the calcination temperature of the precursor. Moreover, hollow and hierarchical Fe0.8Mn1.2O3 sub-microcubes can also be synthesized by further aging the precursor and then using the same strategy. Furthermore, the formation mechanism for the above-mentioned nanostructures is carefully studied. Among all prepared Fe0.8Mn1.2O3 nanostructures, the hierarchical sub-micropolyhedrons exhibit the best lithium-ion storage performance. It can deliver an excellent discharge capacity of 1114.3 mAh g−1 after 100 cycles at 200 mA g−1 and superior rate properties (1268.8, 864.1, 698.9, 556.3, and 397.6 mAh g−1 at 0.2, 1, 2, 4, and 8 A g−1, respectively).
