Mesocarbon microbeads (MCMB) powders, which are known to be highly crystallized carbon materials and have a mean particle size of 11 mum, were treated in RF thermal plasma. Through the plasma treatment, the surface morphology, structure, and chemical composition of the powder were modified. The plasma-induced modification made the surface of MCMB particles disordered, and gave rise to an improvement in the thermal stability and electrochemical properties of the powders, such as the discharge capacity and first charge/discharge efficiency. It also made the powders suitable for further use as an anode in lithium-ion rechargeable batteries. Powders obtained without air exposure showed further improvement in anode performance. (C) 2003 Elsevier B.V. All rights reserved.