Effects of carbonization temperature on microstructure and electrochemical performances of phenolic resin-based carbon spheres

Activated phenol resin-based carbon spheres (APCS) electrodes with high double layer capacitance and good rate capability were prepared from phenol resin-based spheres (PS) at different carbonization temperatures prior to KOH activation. The carbonization temperature has a marked effect on both the pore structure and the electrochemical performances of the APCS in 6M KOH electrolyte. APCS carbonized at 600°C results in higher specific surface area and larger pore size, and hence higher capacitance and better rate capability. The specific capacitance of the APCS in 6M KOH aqueous solution can be as high as 282Fg−1. It remains 252Fg−1 as the current density increases to 1000mAg−1.