Carhons were prepared at different temperatures by pyrolytic treatment of phenolformaldehyde resin molded with ZnCl2 in advance. X-ray structure analyses have shown that these carbon are essentially amorphous with rather loose structure of molecular size order with an interlayer distance of 0.36—0.37 nm. Using electrochemical methods, we have studied the insertion of lithium within these materials. Resole resins, heated to 580 ℃, have a reversible capacity of about 400 mA·h/g, which is beyond the theoretical capacity of graphite（372 mA·h/g） and discover that carbons with a smaller crystallite size and large interlayer distance have the larger discharge capacity.
A new precusor of activated carbon material--sugar was pyrolyzed under many different conditions. Experiments were carried out to search for optimal pyrolyzing conditions. It was found that sugar should be carbonized at 700 ℃ and activated with potassium hydroxide at 800 ℃. The activated carbon prepared from pyrolytic treatment of sugar is therefore potential candidates as electrode material of electric double layer capacitor.
Electric double layer capacitors using activated carbon as their electrodes are peculiar power sources with a high reliability, it is extremely resistant to oxidation, chemical and heat treatment. In this paper, we have developed the material of electric double layer capacitors prepared from pyrolytic treatment of phenol formaldehyde resin. The experiment results of its electrochemical properties show that this kind of capacitor has a large capacity, good cycle life and can be used in a large scale.
