PNNL

Abstract

Hollow Carbon Nanowires (HCNWs) were prepared through pyrolyzation of hollow polyaniline nanowires precursor. The HCNWs used as anode material for Na-ion batteries delivers a high reversible capacity of 251 mAh g-1 and 82.2% capacity retention over 400 charge/discharge cycles between 1.2 and 0.01 V (vs. Na+/Na) at a constant current of 50 mA g-1 (0.2 C). Excellent cycling stability is also observed at even higher charge-discharge rate. A high reversible capacity of 149 mAh g-1 also can be obtained at a current rate of 500 mA g-1 (2C). The good Na ion insertion property is attributed to the short diffusion distance in the HCNWs, and the large interlayer distance (0.37 nm) between the graphitic sheets, which agrees with the interlayered distance predicted by theoretical calculation to enable Na ion insertion in carbon materials.