Layered-structured ternary oxide Na-0.67[Ni0.4Co0.2Mn0.4]O-2 is synthesized as cathode material for sodium-ion batteries. Using a liquid nitrogen quenching process during the synthesis procedure, a Na-0.67[Ni0.4Co0.2Mn0.4]O-2 powder with a mixed P2-O3 structure is obtained, and then characterized. The Na//Na-0.67[Ni0.4Co0.2Mn0.4]O-2 cell delivers a reversible capacity of 167 mA h g(-1) and exhibits excellent cycling and rate performances without abnormal initial coulombic efficiency. (C) 2016 Elsevier Ltd. All rights reserved.