Composite Li-ion anode can be fabricated using silicon nanopowders synthesized by induced plasma atomization. Properties of such nanopowder were characterized by physical and electrochemical methods. Primary particles were crystalline with spherical shape and the typical diameter ranging from 50 to 200 nm. The Si nanopowder showed a high gravimetric capacity (4900 mAh/g) at first discharge and around 12% irreversible loss of lithium. In addition, observations of a single silicon particle made by in situ TEM permitted to compare the volume change during lithiation with other silicon anode nanomaterials.