Four kinds of Si-Ni nanoparticles were prepared by hydrogen plasma-metal reaction as anode materials of a lithium-ion cell. The morphology and crystal structure of nanoparticles were investigated by transmission electron microscopy (TEM), and X-ray diffraction (XRD). The electrochemistry properties were studied as the anode for lithium-ion batteries. During lithium insertion into the alloy electrodes, Si act as active centre, which reacts with Li to form amorphous LixSi alloys, while the Si2Ni in the sample plays the role of matrix as an inertial phase, which can buffer silicon volume expansion and facilitate charge transfer among silicon particles. Electrochemical measurements show that the charge-discharge capacity of Si-Ni alloys increases with decreasing Si2Ni. A high lithium storage capacity of 1304 mAh g(-1) is observed for the Si-Ni alloy at Ni 9.0 at.% in nanoparticles with some reversibility. (c) 2005 Elsevier B.V. All rights reserved.