Preparation Of Activated Carbon From Phenolic Foam With NaOH Used For Supercapacitors

Electrochemical capacitor is a novel storage device between battery and traditional static capacitor, with the advantages of high specific capacitance, high energy, long cycling life, wider work temperatures, voltage memory and free service. The focus of this work is the electrode materials and the system construction of electrochemical capacitor. This paper was addressed on studying the carbon electrode materials for electrochemical capacitors with low cost, high specific energy and high power density. High performance carbon electrodes for capacitors were prepared using phenolic foam as precursor. The preparation technology, structure, capacitance performance and the mechanism of energy storage for carbon electrode materials were deeply investigated.The low cost carbon electrode was prepared by NaOH chemical activation of phenolic foam for the first time, and then assembled to aqueous capacitors. The effect of activation temperature and activation time on the structure and capacitance performance of the electrode materials of electrochemical capacitors were investigated systematically by charge/discharge measurement, cyclic voltammetry and electrochemical impedance spectroscopy measurement. The phenolic foam based micropore carbon prepared under optimum conditions (activation temperature: 700℃; activation time: 5h) had specific surface areas over 1750m~2 /g and pore size of 1-2 nm. The specific discharge capacitance was as high as 266.1F/g in the 30wt% KOH aqueous solution, showing excellent power performance and cycle performance. This method not only makes good use of phenolic foam leftover materials reasonably, but also optimizes the performances of electrochemical capacitors. So, it will have a good future for industry application.