The electrochemical characteristics of a new type of coke for the negative electrode of a Lithium ion battery are investigated. This coke is prepared from natural gas by means of thermoplasma technology. The initial discharge-charge properties of natural gas coke of several kinds are discussed. The effects of surface modification of cokes on the characteristics of lithium intercalation during the first cycle are also explored. The properties of lithium intercalation into carbon electrodes show that the electrochemical behaviour is determined by the nature of the carbon material. The results also demonstrate that the surface properties of carbon electrodes remarkably influence the efficiency of the first cycle. Surface modification of coke electrodes with polymer can increase the initial coulombic efficiency but reduces the initial discharge capacity.