Synthesis and electrochemical performances of layered NaLi0.2Ni0.2Mn0.6O2 cathode for sodium-ion batteries

NaLi0.2Ni0.2Mn0.6O2 oxide with a layered P2-type structure is synthesized by the conventional solid-state reaction method and it is used as the cathode for sodium-ion batteries. In order to enhance the cycling ability of P2-structured NaxMnO2 compounds, we partially substituted manganese by lithium and nickel. The shape of the NaLi0.2Ni0.2Mn0.6O2 particles is rectangular prismatic. The capacity of the NaLi0.2Ni0.2Mn0.6O2 cathode is 117 mA h g−1 and 83 mA h g−1 at 0.1 C and 1 C, respectively. The NaLi0.2Ni0.2Mn0.6O2 cathode exhibits excellent cycling ability with 88% capacity retention over 70 cycles. It is suggested that NaLi0.2Ni0.2Mn0.6O2 oxide is a promising cathode material for sodium-ion batteries.