Sodium-ion batteries (NIBS) have been considered to be the promising alternative to lithium-ion batteries (LIBs) due to the limited availability and uneven distribution of lithium resources. The exploration of anode materials for SIBs was still limited, and transition metal oxides (TMOs) have been widely studied for a long time. MoO2@C nanoflowers were synthesized through a grinding method, followed by an annealing process. In addition, irregular MoO2@C nanoparticles could be synthesized, when the amount of ammonium molybdate was increased by twice while other condition kept the same. With excellent dispersity and structural integrity, the as-obtained MoO2@C nanoflowers deliver a reversible capacity of 172 mAh g(-1) at 0.1 A g(-1) and a capacity of 166 mAh g(-1) after 1000 cycles at 1.0 A g(-1). (C) 2017 Elsevier Ltd. All rights reserved.