Li/Na Storage Properties of Disordered Carbons Synthesized by Mechanical Milling

Impact of structural disorder induced by mechanical milling on electrochemical properties of carbonaceous materials is systematically examined. Carbonaceous materials with different structural disorder are prepared by mechanical milling with different rotation speeds. Thus prepared carbons show sloping voltage profiles in Li/Na cells, which resemble those of soft carbons. The disordered carbon material prepared at 600 rpm shows a reversible capacity of >500 mA h g(-1) in a Li cell. In addition, the disordered carbon also delivers 200 mA h g(-1) in a Na cell with high Coulombic efficiency for continuous cycles. Heat treatment of the disordered carbon results in the formation of hard carbon with nanopores, and thus Li/Na storage properties are significantly changed. (C) The Electrochemical Society of Japan, All rights reserved.