Chain-like and rod-like Co-B nanomaterials ale prepared by chemical I eduction method in cetyltiimethylammonium biomide (CTAB) and polyvinylpyrrolidone (PVP) aqueous solution, respectively XRD patterns demonstrate that the two materials both have amorphous structures SEM and TEM images show that the chain-like Co-B constructs of one-by-one tactic ball-like panicles with nanoflakes on the surface, whereas the rod-like Co-B alloy possesses a porous nanostructure The results of electrochemical measurements indicate that, as negative electrode materials of Ni-MH batteries, their electrochemical properties are both better than those of regular Co-B alloy. At the discharge current density 25 mA g(-1), the discharge capacities of the chain-like and the rod-like Co-B alloys are 314 mAh g(-1) and 292 mAh g(-1) after 50 cycles, respectively, which are both higher than that of regular Co-B alloy XRD patterns of the electrodes on different chai ge-discharge states illustrate that the discharge capacity is attributed to hydrogenation of Co-B alloy (C) 2010 Elsevier Ltd All rights reserved