Mn-contained nano-flowers can be fabricated by dealloying Mn/Al alloys in aqueous NaOH solution in the presence of H2O2, and upon annealing the resulted samples exhibit a hierarchically porous MnO x microsphere morphology composed of nanoparticles of MnO and Mn3O4. When tested as anode materials for lithium ion batteries, those MnO x microspheres exhibit a high specific capacity of 1018, 901 and 757 mAh g−1 with nearly 100% retention capacity after 100 cycles at 100, 200 and 500 mA g−1, respectively. The enhanced storage capacity, impressive cycling performance, and good rate capability for the electrodes are ascribed to the porous structures for buffering the volume change during the discharge/charge processes, and the nano-hybrids for enhancing electronic and ionic transport in the electrode materials.