Study of polypyrrole graphite composite as anode material for secondary lithium-ion batteries

Pyrrole was polymerized onto commercial SFG10 graphite by in situ polymerization technique. Polymerization decreases the initial irreversible capacity loss of the graphite anode, The decrease in the irreversible capacity loss is due to the reduction in the thickness of the solid electrolyte interface (SEI) layer formed. PPy/C (7.8%) gives the optimum performance based on the irreversible capacity loss and the discharge capacity of the composite. The composite material has been studied for specific discharge capacity, coulombic efficiency, rate capability and cycle life using a variety of electrochemical methods. The composite SFG10 graphite possess good reversibility, higher coulombic efficiency, good rate capability and better cycle life than the bare SFG10 graphite. (C) 2002 Elsevier Science B.V. All rights reserved.