CHARACTERISTICS OF PYROLYZED PHENOL-FORMALDEHYDE RESIN AS AN ANODE FOR LITHIUM-ION BATTERIES

Polyacenic semiconductor (PAS) is obtained by pyrolyzing phenol-formal dehyde resin (PFR). The properties of PFR heat-treated at different te mperatures are investigated. The lithium intercalation capacity of PAS as a function of heat-treatment temperature (HTT) exhibits a maximum at around 700 degrees C. A knee appears at 700 degrees C, not only in the plot of atomic ratio [H]/[C] versus HTT, but also in the plot of c onductivity versus HTT. For PAS with a HTT of 700 degrees C, the maxim um in the ratio of the relative intensity of Raman spectra at 1360 cm( -1) corresponds to nanometer graphite, and that at 1580 cm(-1) to grap hite. A reasonable explanation of these phenomena is the transformatio n of nanometer graphite to graphite.