Developing high energy storage lithium ion batteries (LIBs) using manganese oxides as anodes is an attractive challenge due to their high theoretical capacity and abundant resources. However, the manganese oxides anodes still suffer from the low initial Coulombic efficiency and poor rate performance. Herein, we demonstrate that nano-sized morphological engineering is a facile and effective strategy to improve the electrochemical performance of the manganese dioxide (MnO2) for LIBs. The tailored MnO2 nanoparticles (NPs) exhibit high reversible capacity (1095 mAh g−1 at 100 mA g−1), high initial Coulombic efficiency (94.5%) and good rate capability (464 mAh g−1 at 2000 mA g−1). The enhanced electrochemical performance of MnO2 NPs can be attributed to the presences of numerous electrochemically active sites and interspaces among the NPs.