Sodium insertion cathode material Na0.67[Ni0.4Co0.2Mn0.4]O2 with excellent electrochemical properties

Abstract Layered-structured ternary oxide Na 0.67 [Ni 0.4 Co 0.2 Mn 0.4 ]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 [Ni 0.4 Co 0.2 Mn 0.4 ]O 2 powder with a mixed P2-O3 structure is obtained, and then characterized. The Na//Na 0.67 [Ni 0.4 Co 0.2 Mn 0.4 ]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.