A Novel Layered Birnessite-type Sodium Molybdate as Dual-ion Electrodes for High Capacity Battery

Abstract A birnessite-type Na1/3MoO2•H2O with a large interlayer distance has been synthesized by solid-state reaction and water treatment for the first time. The obtained Na1/3MoO2•H2O is phase-pure and well-crystallized as determined by X-ray structure refinement and presents a typical plate-like microstructure. Surprisingly, the Na1/3MoO2•H2O can be used as both anode and cathode electrodes for Li-ion batteries (LIBs), which shows long cycle life ((anode, 500 cycles~650 mAh g−1), and high capacity of 300 mAh g−1 (cathode). This high performance is ascribed to the PF6− intercalation mechanism of Na1/3MoO2•H2O based on the density functional theory (DFT) calculations. This work offers an efficient way for the design of electrode materials and sheds light on the application of the Na1/3MoO2•H2O for high capacity dual-ion batteries (DIBs).