Optimizing pyrolysis of sugar carbons for use as anode materials in lithium-ion batteries

Table sugar was pyrolyzed under various conditions. Carbons of pyrolyzed sugar demonstrated high capacity for Li intercalation, exceeding that of graphite. Experiments were carried out to search for optimal pyrolyzing conditions. The electrochemical behavior of these carbons was found to depend on the pyrolysis temperature, heating rate, argon gas flow rate, and morphology of the precursors. Pyrolysis of sugar was also carried out under vacuum, which is equivalent to a high argon gas flow. Carbons of pyrolyzed sugar under optimal conditions showed large reversible capacity, approximate to 650 mAh/g, small irreversible capacity, less than or equal to 170 mAh/g, and small hysteresis between discharge and charge in carbon/Li metal electrochemical test cells. Pyrolyzed sugar carbons are therefore potential candidates as anode materials in Li-ion batteries.