Preparation of activated carbon paper by a novel method and application as high-performance supercapacitors

In this paper, the commercial carbon papers were firstly treated by potassium dichromate lotion. Their surfaces became rougher and specific surface areas were enlarged. Accordingly, their surface hydrophilicity were enhanced due to the intake of hydrophilic groups such as hydroxyl (-OH), carbonyl (> C=O), and carboxyl (-COOH), and they act as strong polar sites to absorb water molecules. Supercapacitors were then constructed with the treated carbon paper as electrode and PVA-H3PO4 gel as electrolyte, and they provided high areal capacitances, high-rate capability, long-life cycle, and low resistance due to the synergistic effect of enlarged specific surface area and enhanced surface hydrophilicity.