Electrochemical hydrogen storage behavior of ropes of aligned single-walled carbon nanotubes

Massive macroscopic ropes of well-aligned single-walled carbon nanotubes (SWNTs) with a larger mean diameter of about 1.72 nm, synthesized by a semicontinuous hydrogen arc discharge method, were employed for electrochemical hydrogen adsorption experiments. A high discharge capacity of 503 mAh/g, corresponding to 1.84 wt % hydrogen, was achieved reproducibly at 25degreesC under normal atmosphere for about 200 mg SWNT sample. This result implies that the SWNTs are highly promising electrochemical hydrogen storage materials for rechargeable batteries.