Optimization of Fabrication Parameters to Enhance the Performance of Activated Carbon Air-Cathode

The aim of this work was to investigate the effect of three key fabrication factors (i.e. pressure, AC/PTFE mass ratio, and AC load) on the performance of activated carbon air-cathode (ACAC). The design of experiment work was performed with the response surface methodology (RSM) using the central composite design. 20 combinations of the three variables were optimized based on the responses evaluated by linear sweep voltammetry (LSV). The results showed that the proposed mathematical model in the RSM could be used adequately for prediction and optimization within the factor levels investigated. The combined optimum fabrication parameters that gave the highest performance of ACAC were pressure 10 MPa, AC/PTFE mass ratio 6 and AC load 0.3 g. The fabricated ACACs were characterized by Electrochemical Impedance Spectroscopy (EIS), Brunauer-Emmett-Teller (BET) test and fuel cell test. The characterization results demonstrated that the improved performance of ACAC owed to the increase of both specific surface area and conductivity, and the controlled surface hydrophilicity/hydrophobicity. (C) 2015 The Electrochemical Society. All rights reserved.